Combined electrophoretic-separation and electrospray method and system

Science.gov (United States)

Smith, R.D.; Olivares, J.A.

1989-06-27

A system and method for analyzing molecular constituents of a composition sample includes: forming a solution of the sample, separating the solution by capillary zone electrophoresis into an eluent of constituents longitudinally separated according to their relative electrophoretic mobilities, electrospraying the eluent to form a charged spray in which the molecular constituents have a temporal distribution; and detecting or collecting the separated constituents in accordance with the temporal distribution in the spray. A first high-voltage (e.g., 5--100 kVDC) is applied to the solution. The spray is charged by applying a second high voltage (e.g., [+-]2--8 kVDC) between the eluent at the capillary exit and a cathode spaced in front of the exit. A complete electrical circuit is formed by a conductor which directly contacts the eluent at the capillary exit. 10 figs.

Experimental design and instability analysis of coaxial electrospray process for microencapsulation of drugs and imaging agents.

Science.gov (United States)

Si, Ting; Zhang, Leilei; Li, Guangbin; Roberts, Cynthia J; Yin, Xiezhen; Xu, Ronald

2013-07-01

Recent developments in multimodal imaging and image-guided therapy requires multilayered microparticles that encapsulate several imaging and therapeutic agents in the same carrier. However, commonly used microencapsulation processes have multiple limitations such as low encapsulation efficiency and loss of bioactivity for the encapsulated biological cargos. To overcome these limitations, we have carried out both experimental and theoretical studies on coaxial electrospray of multilayered microparticles. On the experimental side, an improved coaxial electrospray setup has been developed. A customized coaxial needle assembly combined with two ring electrodes has been used to enhance the stability of the cone and widen the process parameter range of the stable cone-jet mode. With this assembly, we have obtained poly(lactide-co-glycolide) microparticles with fine morphology and uniform size distribution. On the theoretical side, an instability analysis of the coaxial electrified jet has been performed based on the experimental parameters. The effects of process parameters on the formation of different unstable modes have been studied. The reported experimental and theoretical research represents a significant step toward quantitative control and optimization of the coaxial electrospray process for microencapsulation of multiple drugs and imaging agents in multimodal imaging and image-guided therapy.

Electrosprayed Polyvinylpyrrolidone (PVP) Submicron Particles Loaded by Green Tea Extracts

Science.gov (United States)

Kamaruddin; Sriyanti, I.; Edikresnha, D.; Munir, M. M.; Khairurrijal, K.

2018-05-01

Electrospraying technique has been successfully used to synthesize composite submicron particles of polyvinylpyrrolidone (PVP) and green tea extract (GTE). The precursor solutions were PVP in ethanol (15 wt%) and GTE in ethanol (10 wt%), which were then mixed at varying ratio. The mixed solution then underwent electrospraying process at an applied voltage of 15 kV, a distance of collector to the nozzle at 15 cm, and a flow rate of 3 µL/min. The composite submicron particles of PVP-GTE showed smooth and fine spherical morphology without fibers or beaded fibers. To a certain degree, the increase of GTE content in the PVP-GTE mixed solution decreased the average diameter of PVP-GTE composite particles. Moreover, the analysis of the FTIR spectra confirmed the existing molecular interaction between PVP and GTE in the composite submicron particles as shown by the shift of PVP wavenumber towards GTE, which has typically smaller wavenumber.

A preliminary report on a novel electrospray technique for nanoparticle based biomedical implants coating: precision electrospraying.

Science.gov (United States)

Kumbar, Sangamesh G; Bhattacharyya, Subhabrata; Sethuraman, Swaminathan; Laurencin, Cato T

2007-04-01

The compatibility and biological efficacy of biomedical implants can be enhanced by coating their surface with appropriate agents. For predictable functioning of implants in situ, it is often desirable to obtain an extremely uniform coating thickness without effects on component dimensions or functions. Conventional coating techniques require rigorous processing conditions and often have limited adhesion and composition properties. In the present study, the authors report a novel precision electrospraying technique that allows both degradable and nondegradable coatings to be placed. Thin metallic slabs, springs, and biodegradable sintered microsphere scaffolds were coated with poly(lactide-co-glycolide) (PLAGA) using this technique. The effects of process parameters such as coating material concentration and applied voltage were studied using PLAGA and poly(ethylene glycol) coatings. Morphologies of coated surfaces were qualitatively characterized by scanning electron microscopy. Qualitative observations suggested that the coatings were composed of particles of various size/shape and agglomerates with different porous architectures. PLAGA coatings of uniform thickness were observed on all surfaces. Spherical nanoparticle poly(ethylene glycol) coatings (462-930 nm) were observed at all concentrations studied. This study found that the precision electrospraying technique is elegant, rapid, and reproducible with precise control over coating thickness (mum to mm) and is a useful alternative method for surface modification of biomedical implants. (c) 2006 Wiley Periodicals, Inc.

A Comparison of Alternating Current and Direct Current Electrospray Ionization for Mass Spectrometry

Science.gov (United States)

Sarver, Scott A.; Chetwani, Nishant; Dovichi, Norman J.; Go, David B.; Gartner, Carlos A.

2014-04-01

A series of studies comparing the performance of alternating current electrospray ionization (AC ESI) mass spectrometry (MS) and direct current electrospray ionization (DC ESI) MS have been conducted, exploring the absolute signal intensity and signal-to-background ratios produced by both methods using caffeine and a model peptide as targets. Because the high-voltage AC signal was more susceptible to generating gas discharges, the operating voltage range of AC ESI was significantly smaller than that for DC ESI, such that the absolute signal intensities produced by DC ESI at peak voltages were one to two orders of magnitude greater than those for AC ESI. Using an electronegative nebulizing gas, sulfur hexafluoride (SF6), instead of nitrogen (N2) increased the operating range of AC ESI by ~50 %, but did not appreciably improve signal intensities. While DC ESI generated far greater signal intensities, both ionization methods produced comparable signal-to-background noise, with AC ESI spectra appearing qualitatively cleaner. A quantitative calibration analysis was performed for two analytes, caffeine and the peptide MRFA. AC ESI utilizing SF6 outperforms all other techniques for the detection of MRFA, producing chromatographic limits of detection nearly one order of magnitude lower than that of DC ESI utilizing N2, and one-half that of DC ESI utilizing SF6. However, DC ESI outperforms AC ESI for the analysis of caffeine, indicating that improvements in spectral quality may benefit certain compounds or classes of compounds, on an individual basis.

Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet

Science.gov (United States)

Sohbatzadeh, F.; Eshghabadi, M.; Mohsenpour, T.

2018-06-01

The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

The effect of the molecular mass on the sputtering by electrosprayed nanodroplets

Energy Technology Data Exchange (ETDEWEB)

Borrajo-Pelaez, Rafael; Gamero-Castaño, Manuel, E-mail: mgameroc@uci.edu

2015-07-30

Highlights: • We study the effect of the molecular mass on nanodroplet sputtering of silicon. • The impact phenomenology is a strong function of the projectile’s molecular mass. • Nanodroplet sputtering intrinsically is a molecular scale phenomenon. - Abstract: Energetic bombardment of covalently bonded materials by electrosprayed nanodroplets causes sputtering and topographic changes on the surface of the target. This work investigates the influence of the projectile's molecular mass on these phenomena by sputtering single-crystal silicon wafers with a variety of liquids (molecular masses between 45.0 and 773.3 amu), and acceleration voltages. The electrosprays are characterized via time of flight to determine the charge to mass ratio of the nanodroplets which, together with the acceleration voltage, yield the impact velocity, the stagnation pressure, and the molecular kinetic energy of the projectile. The estimated range of droplet diameters is 20–79 nm, while the impact velocity, the stagnation pressure and the molecular kinetic energy range between 2.9–10 km/s, 4.7–63 GPa, and 2.1–98 eV. We find that the damage on the surface of the targets strongly depends on the molecular mass of the projectile: liquids with low molecular mass sputter significantly less and produce nanometric indentations and low surface roughness, the latter increasing moderately with stagnation pressure; in contrast, the roughness and sputtering caused by the impacts of droplets with larger molecular mass reach significantly higher values, and exhibit non-monotonic behaviors. The maximum sputtering yields for formamide, EAN, EMI-BF{sub 4}, EMI-Im, TES, and TPP are 0.20, 0.75, 1.20, 2.80, 4.00 and 2.90 silicon atoms per molecule in the projectile. These trends indicate that despite their rather large diameters, the sputtering by electrosprayed nanodroplets is intrinsically a molecular scale phenomenon.

Coaxial Electrospray of Curcumin-Loaded Microparticles for Sustained Drug Release.

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Shuai Yuan

Full Text Available Curcumin exhibits superior anti-inflammatory, antiseptic and analgesic activities without significant side effects. However, clinical dissemination of this natural medicine is limited by its low solubility and poor bio-availability. To overcome this limitation, we propose to encapsulate curcumin in poly(lactic-co-glycolic acid (PLGA microparticles (MPs by an improved coaxial electrospray (CES process. This process is able to generate a stable cone-jet mode in a wide range of operation parameters in order to produce curcumin-loaded PLGA MPs with a clear core-shell structure and a designated size of several micrometers. In order to optimize the process outcome, the effects of primary operation parameters such as the applied electric voltages and the liquid flow rates are studied systemically. In vitro drug release experiments are also carried out for the CES-produced MPs in comparison with those by a single axial electrospray process. Our experimental results show that the CES process can be effectively controlled to encapsulate drugs of low aqueous solubility for high encapsulation efficiency and optimal drug release profiles.

Preparation and optimization of submicron chitosan capsules by water-based electrospraying for food and bioactive packaging applications.

Science.gov (United States)

Sreekumar, Sruthi; Lemke, Philipp; Moerschbacher, Bruno M; Torres-Giner, Sergio; Lagaron, Jose M

2017-10-01

In the present study, a well-defined set of chitosans, with different degrees of acetylation (DA) and degrees of polymerization (DP), were processed by solution electrospraying from a water-based solvent. The solution properties, in terms of surface tension, conductivity, viscosity, and pH, were characterized and related to the physico-chemical properties of the chitosans. It was observed that both DA and DP values of a given chitosan, in combination with biopolymer concentration, mainly determined solution viscosity. This was, in turn, the major driving factor that defined the electrosprayability of chitosan. In addition, the physico-chemical properties of chitosans highly influenced solution conductivity and results indicated that the chitosan solutions with low or low-to-medium values of conductivity were the most optimal for electrospraying. The results obtained here also demonstrate that a good process control can be achieved by adjusting the working conditions, i.e. applied voltage, flow-rate, and tip-to-collector distance. Finally, it was also shown that electrosprayability of chitosan with inadequate physico-chemical properties can be improved by solution mixing of very different kinds of this polysaccharide. The resultant electrosprayed submicron chitosan capsules can be applied for encapsulation of food additives and to develop bioactive coatings of interest in food packaging, where these particles alone or containing functional ingredients can be released from the package into the food to promote a health benefit.

Online monitoring of chemical reactions by polarization-induced electrospray ionization.

Science.gov (United States)

Meher, Anil Kumar; Chen, Yu-Chie

2016-09-21

Polarization-induced electrospray ionization (PI-ESI) is a simple technique for instant generation of gas-phase ions directly from a microliter-sized droplet for mass spectrometric analysis. A sample droplet was placed over a dielectric substrate and in proximity (2-3 mm) to the inlet of a mass spectrometer. Owing to the polarization effect induced by the high electric field provided by the mass spectrometer, the droplet was polarized and the electrospray was generated from the apex of the droplet. The polarization-induced electrospray could last for tens of seconds, which was sufficiently long to monitor fast reactions occurring within few seconds. Thus, we demonstrated the feasibility of using the droplet-based PI-ESI MS for the online monitoring of fast reactions by simply mixing two droplets (5-10 μL) containing reactants on a dielectric substrate placed in front of a mass spectrometer applied with a high voltage (-4500 V). Schiff base reactions and oxidation reactions that can generate intermediates/products within a few seconds were selected as the model reactions. The ionic reaction species generated from intermediates and products can be simultaneously monitored by PI-ESI MS in real time. We also used this approach to selectively detect acetone from a urine sample, in which acetone was derivatized in situ. In addition, the possibility of using this approach for quantitative analysis of acetone from urine samples was examined. Copyright © 2016 Elsevier B.V. All rights reserved.

On-line coupling of a microelectrode array equipped poly(dimethylsiloxane) microchip with an integrated graphite electrospray emitter for electrospray ionisation mass spectrometry.

Science.gov (United States)

Liljegren, Gustav; Dahlin, Andreas; Zettersten, Camilla; Bergquist, Jonas; Nyholm, Leif

2005-10-01

A novel method for the manufacturing of microchips for on-chip combinations of electrochemistry (EC) and sheathless electrospray ionisation mass spectrometry (ESI-MS) is described. The technique, which does not require access to clean-room facilities, is based on the incorporation of an array of gold microcoil electrodes into a poly(dimethylsiloxane)(PDMS) microflow channel equipped with an integrated graphite based sheathless ESI emitter. Electrochemical measurements, which were employed to determine the electroactive area of the electrodes and to test the microchips, show that the manufacturing process was reproducible and that the important interelectrode distance in the electrochemical cell could to be adequately controlled. The EC-ESI-MS device was evaluated based on the ESI-MS detection of the oxidation products of dopamine. The results demonstrate that the present on-chip approach enables full potentiostatic control of the electrochemical cell and the attainment of very short transfer times between the electrochemical cell and the electrospray emitter. The transfer times were 0.6 and 1.2 s for flow rates of 1.0 and 0.5 microL min(-1), respectively, while the electrochemical conversion efficiency of the electrochemical cell was found to be 30% at a flow rate of 0.5 microL min(-1). To decouple the electrochemical cell from the ESI-MS high voltage and to increase the user-friendliness, the on-line electrochemistry-ESI-MS experiments were performed using a wireless Bluetooth battery-powered instrument with the chip floating at the potential induced by the ESI high voltage. The described on-chip EC-ESI-MS device can be used for fundamental electrochemical investigations as well as for applications based on the use of electrochemically controlled sample pretreatment, preconcentration and ionisation steps prior to ESI-MS.

Nanoparticle electrostatic loss within corona needle charger during particle-charging process

International Nuclear Information System (INIS)

Huang Chenghsiung; Alonso, Manuel

2011-01-01

A numerical investigation has been carried out to examine the electrostatic loss of nanoparticles in a corona needle charger. Two-dimensional flow field, electric field, particle charge, and particle trajectory were simulated to obtain the electrostatic deposition loss at different conditions. Simulation of particle trajectories shows that the number of charges per particle during the charging process depends on the particle diameter, radial position from the symmetry axis, applied voltage, Reynolds number, and axial distance along the charger. The numerical results of nanoparticle electrostatic loss agreed fairly well with available experimental data. The results reveal that the electrostatic loss of nanoparticles increases with increasing applied voltage and electrical mobility of particles; and with decreasing particle diameter and Reynolds number. A regression equation closely fitted the obtained numerical results for different conditions. The equation is useful for directly calculating the electrostatic loss of nanoparticles in the corona needle charger during particle-charging process.

Probe-Substrate Distance Control in Desorption Electrospray Ionization

Science.gov (United States)

Yarger, Tyler J.; Yuill, Elizabeth M.; Baker, Lane A.

2018-03-01

We introduce probe-substrate distance (Dps)-control to desorption electrospray ionization (DESI) and report a systematic investigation of key experimental parameters. Examination of voltage, flow rate, and nebulizing gas pressure suggests as Dps decreases, the distance-dependent spray current increases, until a critical point. At the critical point the relationship inverts, and the spray current decreases as the probe moves closer to the surface due to constriction of solution flow by the nebulizing gas. Dps control was used to explore the use of spray current as a signal for feedback positioning, while mass spectrometry imaging was performed simultaneously. Further development of this technique is expected to find application in study of structure-function relationships for clinical diagnostics, biological investigation, and materials characterization. [Figure not available: see fulltext.

Formation of Sol Gel Dried Droplets of Carbon Doped Titanium Dioxide (TiO2) at Low Temperature via Electrospraying

Science.gov (United States)

Halimi, S. U.; Hashib, S. Abd; Abu Bakar, N. F.; Ismail, S. N.; Nazli Naim, M.; Rahman, N. Abd; Krishnan, J.

2018-05-01

The high band gap energy of TiO2 and inconsistency in particles size has imposed a significant drawback on TiO2 applications. Dried droplets of carbon-doped TiO2 fine particles were produced by using electrospraying technique. The C-doped TiO2 particles were prepared by hydrolysis of titanium isopropoxide with the addition of carbon precursor followed by electrospraying the suspension in stable Taylor cone-jet mode. Coulomb fission of charged droplets from the electrospraying technique successfully transformed dispersed liquid C-doped TiO2 particles into solid. The deposited C-doped TiO2 droplets were collected on aluminium substrates placed at working distances of 10 to 20 cm from the tip of the electrospray needle. The collected C-doped TiO2 droplets were characterized by using FESEM, UV-Vis, FTIR and XRD. By increasing the working distance, the average droplets size of the deposited C-doped TiO2 was reduced from ±163.2 nm to ±147.56 nm. UV-Vis analysis showed a strong absorption in the visible-light region and about 93 nm red shift of the onset spectrum for C-doped TiO2. The red shift indicates an increase in photocatalytic efficiency by reducing the TiO2 band gap energy from 3.0 eV to 2.46 eV and shifting its activity to the visible-light region. FTIR analysis indicated the presence of Ti-C and C-O chemical bonding in the C-doped TiO2.

Improved Morphology of Poly(3,4-ethylenedioxythiophene:Poly(styrenesulfonate Thin Films for All-Electrospray-Coated Organic Photovoltaic Cells

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Yingjie Liao

2016-01-01

Full Text Available Spray coating technique has been established as a promising substitute for the traditional coating methods in the fabrication of organic devices in many reports recently. Control of film morphology at the microscopic scale is critical if spray-coated devices are to achieve high performance. Here we investigate electrospray deposition protocols for the fabrication of poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS thin films with a single additive system under ambient conditions at room temperature. Critical deposition parameters including solution composition, applied voltage, and relative humidity are discussed systematically. Optimized process for preparing homogenous PEDOT:PSS thin films is applied to all-electrospray-coated organic photovoltaic cells and contributes to a power conversion efficiency comparable to that of the corresponding all-spin-coated device.

Presentation of Various Tactile Sensations Using Micro-Needle Electrotactile Display.

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Mayuko Tezuka

Full Text Available Tactile displays provoke tactile sensations by artificially stimulating tactile receptors. While many types of tactile displays have been developed, electrotactile displays that exploit electric stimulation can be designed to be thin, light, flexible and thus, wearable. However, the high voltages required to stimulate tactile receptors and limited varieties of possible sensations pose problems. In our previous work, we developed an electrotactile display using a micro-needle electrode array that can drastically reduce the required voltage by penetrating through the high-impedance stratum corneum painlessly, but displaying various tactile sensations was still a challenge. In this work, we demonstrate presentation of tactile sensation of different roughness to the subjects, which is enabled by the arrangement of the electrodes; the needle electrodes are on the fingertip and the ground electrode is on the fingernail. With this arrangement, the display can stimulate the tactile receptors that are located not only in the shallow regions of the finger but also those in the deep regions. It was experimentally revealed that the required voltage was further reduced compared to previous devices and that the roughness presented by the display was controlled by the pulse frequency and the switching time, or the stimulation flow rate. The proposed electrotactile display is readily applicable as a new wearable haptic device for advanced information communication technology.

Ion concentration in micro and nanoscale electrospray emitters.

Science.gov (United States)

Yuill, Elizabeth M; Baker, Lane A

2018-06-01

Solution-phase ion transport during electrospray has been characterized for nanopipettes, or glass capillaries pulled to nanoscale tip dimensions, and micron-sized electrospray ionization emitters. Direct visualization of charged fluorophores during the electrospray process is used to evaluate impacts of emitter size, ionic strength, analyte size, and pressure-driven flow on heterogeneous ion transport during electrospray. Mass spectrometric measurements of positively- and negatively-charged proteins were taken for micron-sized and nanopipette emitters under low ionic strength conditions to further illustrate a discrepancy in solution-driven transport of charged analytes. A fundamental understanding of analyte electromigration during electrospray, which is not always considered, is expected to provide control over selective analyte depletion and enrichment, and can be harnessed for sample cleanup. Graphical abstract Fluorescence micrographs of ion migration in nanoscale pipettes while solution is electrosprayed.

Dehydrodimerization of pterostilbene during electrospray ionization mass spectrometry

KAUST Repository

Raji, Misjudeen

2013-04-30

RATIONALE Pterostilbene is a member of the hydroxystilbene family of compounds commonly found in plants such as blueberry and grapes. During the analysis of this compound by electrospray ionization mass spectrometry (ESI-MS), an ion was observed that corresponds to the dehydrodimer of pterostilbene in mass-to-charge ratio. Since such unexpected dimerization may lead to decreased monomer signal during quantitative analysis, it was of interest to identify the origin and structure of the observed pterostilbene dimer and examine the experimental conditions that influence its formation. METHODS Liquid Chromatography/Mass Spectrometry (LC/MS), Nuclear Magnetic Resonance (NMR), and High-Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) were used to examine the origin of the dimerization products. The structure of the formed pterostilbene dimer was examined by performing MSn analysis on the dimer ion. Effects of solvent composition, analyte concentration, radical scavenger, and other experimental conditions on the dimerization were also studied. RESULTS LC/MS and NMR analyses clearly showed that the starting solution did not contain the pterostilbene dimer. Solvent type and radical scavenger concentration were found to have pronounced effects on the dimer formation. Particularly, presence of acetonitrile or ammonium acetate had favorable effects on the extent of dimerization during ESI-MS analysis whereas hydroquinone and butylated hydroquinone had negative effects. Dimer formation decreased at high flow rates and when fused-silica capillary was used as the spray needle. CONCLUSIONS The data indicate that this dimerization occurs as a result of solution-phase electrochemical reactions taking place during the electrospray process. A possible structure for this dimer was proposed based on the MSn analysis and was similar to that of the enzymatically derived pterostilbene dehydrodimer already reported in the literature. Copyright © 2013 John Wiley & Sons, Ltd

Bone biopsy needles. Mechanical properties, needle design and specimen quality

International Nuclear Information System (INIS)

Keulers, Annika; Penzkofer, T.; Cunha-Cruz, V.C.; Bruners, P.; Helmholtz Inst. fuer biomedizinische Technik, Aachen; Braunschweig, T.; Schmitz-Rode, T.; Mahnken, A.; Helmholtz Inst. fuer biomedizinische Technik, Aachen

2011-01-01

To quantitatively analyze differences in mechanical properties, needle design including signs of wear, subjective handling and specimen quality of bone biopsy needles. Materials and Methods: In this study 19 different bone biopsy systems (total 38; 2 /type) were examined. With each biopsy needle five consecutive samples were obtained from vertebral bodies of swine. During puncture a force-torques sensor measured the mechanical properties and subjective handling was assessed. Before and after each biopsy the needles were investigated using a profile projector and signs of wear were recorded. Afterwards, a pathologist semi-quantitatively examined the specimen regarding sample quality. The overall evaluation considered mechanical properties, needle wear, subjective handling and sample quality. Differences were assessed for statistical significance using ANOVA and t-test. Results: Needle diameter (p = 0.003) as well as needle design (p = 0.008) affect the mechanical properties significantly. Franseen design is significantly superior to other needle designs. Besides, length reduction recorded by the profile projector, as a quality criterion showed notable distinctions in between the needle designs. Conclusion: Bone biopsy needles vary significantly in performance. Needle design has an important influence on mechanical properties, handling and specimen quality. Detailed knowledge of those parameters would improve selecting the appropriate bone biopsy needle. (orig.)

Production and properties of electrosprayed sericin nanopowder

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Najmeh Hazeri, Hossein Tavanai and Ali Reza Moradi

2012-01-01

Full Text Available Sericin is a proteinous substrate that envelops fibroin (silk fiber, and its recovery provides significant economical and social benefits. Sericin is an antibacterial agent that resists oxidation and absorbs moisture and UV light. In powder form, sericin has a wide range of applications in food, cosmetics and drug delivery. Asides from other techniques of producing powder, such as precipitation and spray drying, electrospraying can yield solid nanoparticles, particularly in the submicron range. Here, we report the production of sericin nanopowder by electrospraying. Sericin sponge was recovered from Bombyx mori cocoons through a high-temperature, high-pressure process, followed by centrifugation and freeze drying of the sericin solution. The electrospraying solution was prepared by dissolving the sericin sponge in dimethyl sulfoxide. We demonstrate that electrospraying is capable of producing sericin nanopowder with an average particle size of 25 nm, which is by far smaller than the particles produced by other techniques. The electrosprayed sericin nanopowder consists of small crystallites and exhibits a high moisture absorbance.

Production and properties of electrosprayed sericin nanopowder

Energy Technology Data Exchange (ETDEWEB)

Hazeri, Najmeh; Tavanai, Hossein; Moradi, Ali Reza, E-mail: tavanai@cc.iut.ac.ir [Department of Textile Engineering, Centre of Excellence in Applied Nanotechnology, Isfahan, University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

2012-06-15

Sericin is a proteinous substrate that envelops fibroin (silk) fiber, and its recovery provides significant economical and social benefits. Sericin is an antibacterial agent that resists oxidation and absorbs moisture and UV light. In powder form, sericin has a wide range of applications in food, cosmetics and drug delivery. Asides from other techniques of producing powder, such as precipitation and spray drying, electrospraying can yield solid nanoparticles, particularly in the submicron range. Here, we report the production of sericin nanopowder by electrospraying. Sericin sponge was recovered from Bombyx mori cocoons through a high-temperature, high-pressure process, followed by centrifugation and freeze drying of the sericin solution. The electrospraying solution was prepared by dissolving the sericin sponge in dimethyl sulfoxide. We demonstrate that electrospraying is capable of producing sericin nanopowder with an average particle size of 25 nm, which is by far smaller than the particles produced by other techniques. The electrosprayed sericin nanopowder consists of small crystallites and exhibits a high moisture absorbance. (paper)

Pulsed Direct Current Electrospray: Enabling Systematic Analysis of Small Volume Sample by Boosting Sample Economy.

Science.gov (United States)

Wei, Zhenwei; Xiong, Xingchuang; Guo, Chengan; Si, Xingyu; Zhao, Yaoyao; He, Muyi; Yang, Chengdui; Xu, Wei; Tang, Fei; Fang, Xiang; Zhang, Sichun; Zhang, Xinrong

2015-11-17

We had developed pulsed direct current electrospray ionization mass spectrometry (pulsed-dc-ESI-MS) for systematically profiling and determining components in small volume sample. Pulsed-dc-ESI utilized constant high voltage to induce the generation of single polarity pulsed electrospray remotely. This method had significantly boosted the sample economy, so as to obtain several minutes MS signal duration from merely picoliter volume sample. The elongated MS signal duration enable us to collect abundant MS(2) information on interested components in a small volume sample for systematical analysis. This method had been successfully applied for single cell metabolomics analysis. We had obtained 2-D profile of metabolites (including exact mass and MS(2) data) from single plant and mammalian cell, concerning 1034 components and 656 components for Allium cepa and HeLa cells, respectively. Further identification had found 162 compounds and 28 different modification groups of 141 saccharides in a single Allium cepa cell, indicating pulsed-dc-ESI a powerful tool for small volume sample systematical analysis.

Needle Decompression in Appalachia Do Obese Patients Need Longer Needles?

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Carter, Thomas Edward

2013-11-01

Full Text Available Introduction: Needle decompression of a tension pneumothorax can be a lifesaving procedure. It requires an adequate needle length to reach the chest wall to rapidly remove air. With adult obesity exceeding one third of the United States population in 2010, we sought to evaluate the proper catheter length that may result in a successful needle decompression procedure. Advance Trauma Life Support (ATLS currently recommends a 51 millimeter (mm needle, while the needles stocked in our emergency department are 46 mm. Given the obesity rates of our patient population, we hypothesize these needles would not have a tolerable success rate of 90%. Methods: We retrospectively reviewed 91 patient records that had computed tomography of the chest and measured the chest wall depth at the second intercostal space bilaterally. Results: We found that 46 mm needles would only be successful in 52.7% of our patient population, yet the ATLS recommended length of 51 mm has a success rate of 64.8%. Therefore, using a 64 mm needle would be successful in 79% percent of our patient population. Conclusion: Use of longer length needles for needle thoracostomy is essential given the extent of the nation’s adult obesity population. [West J Emerg Med. 2013;14(6:650-652.

Does a paresthesia during spinal needle insertion indicate intrathecal needle placement?

Science.gov (United States)

Pong, Ryan P; Gmelch, Benjamin S; Bernards, Christopher M

2009-01-01

Paresthesias are relatively common during spinal needle insertion, however, the clinical significance of the paresthesia is unknown. A paresthesia may result from needle-to-nerve contact with a spinal nerve in the epidural space, or, with far lateral needle placement, may result from contact with a spinal nerve within the intervertebral foramen. However, it is also possible and perhaps more likely, that paresthesias occur when the spinal needle contacts a spinal nerve root within the subarachnoid space. This study was designed to test this latter hypothesis. Patients (n = 104) scheduled for surgery under spinal anesthesia were observed during spinal needle insertion. If a paresthesia occurred, the needle was fixed in place and the stylet removed to observe whether cerebrospinal fluid (CSF) flowed from the hub. The presence of CSF was considered proof that the needle had entered the subarachnoid space. Paresthesias occurred in 14/103 (13.6%) of patients; 1 patient experienced a paresthesia twice. All paresthesias were transient. Following a paresthesia, CSF was observed in the needle hub 86.7% (13/15) of the time. Our data suggest that the majority of transient paresthesias occur when the spinal needle enters the subarachnoid space and contacts a spinal nerve root. Therefore, when transient paresthesias occur during spinal needle placement it is appropriate to stop and assess for the presence of CSF in the needle hub, rather than withdraw and redirect the spinal needle away from the side of the paresthesia as some authors have suggested.

Analysis of a Steerable Needle for Fine Needle Aspiration and Biopsy: Efficiency and Radiation Dose Compared With a Conventional Straight Needle.

Science.gov (United States)

Rutigliano, Sandra; Abraham, John A; Kenneally, Barry E; Zoga, Adam C; Nevalainen, Mika; Roedl, Johannes B

Percutaneous computed tomography (CT)-guided needle biopsy has proven to be an efficacious method for sampling of many soft tissue lesions, especially deep-seated masses in the abdomen and pelvis. This study sought to test the potential for a novel steerable needle to improve localization and to reduce procedure duration and radiation dose compared with a conventional straight needle. A fresh, raw meat sample (lean bovine flank) was imbedded with cylindrical radiopaque and radiolucent obstacles designed to simulate vessels (radiolucent objects) and bones (radiopaque objects) on CT. A pit-containing olive (partially radiopaque) was imbedded beyond the obstacles to represent the target. Two sites on the surface of the meat were selected and marked to determine initial needle placement. Two radiologists with different levels of experience proceeded to position a straight needle and the steerable needle from each skin site to the target using CT guidance as efficiently as possible, avoiding the obstacles. The total positioning time, the number of CT scans required for positioning, and the number of repositioning events (partial withdrawal followed by advancement) were tracked for the straight and steerable needles. For the straight needle, total time to reach the target was 499 to 667 seconds (mean, 592 seconds); for the steerable needle, total time to reach the target was 281 to 343 seconds (mean, 309 seconds), on average, 48% lower. The number of CT scans needed for needle positioning averaged 6.25 for the straight needle and 3.5 for the steerable needle, which is 44% lower. Repositioning events (withdrawing and readvancing the needle) ranged from 3 to 10 for the straight needle (mean, 6.5) and 0 for the steerable needle. Using an in vitro model embedded with obstacles, the steerable needle performed better than a straight needle with regard to procedure time, needle repositioning events, and CT scans required for placement.

TU-H-CAMPUS-JeP3-05: Adaptive Determination of Needle Sequence HDR Prostate Brachytherapy with Divergent Needle-By-Needle Delivery

International Nuclear Information System (INIS)

Borot de Battisti, M; Maenhout, M; Lagendijk, J J W; Van Vulpen, M; Moerland, M A; Denis de Senneville, B; Hautvast, G; Binnekamp, D

2016-01-01

Purpose: To develop a new method which adaptively determines the optimal needle insertion sequence for HDR prostate brachytherapy involving divergent needle-by-needle dose delivery by e.g. a robotic device. A needle insertion sequence is calculated at the beginning of the intervention and updated after each needle insertion with feedback on needle positioning errors. Methods: Needle positioning errors and anatomy changes may occur during HDR brachytherapy which can lead to errors in the delivered dose. A novel strategy was developed to calculate and update the needle sequence and the dose plan after each needle insertion with feedback on needle positioning errors. The dose plan optimization was performed by numerical simulations. The proposed needle sequence determination optimizes the final dose distribution based on the dose coverage impact of each needle. This impact is predicted stochastically by needle insertion simulations. HDR procedures were simulated with varying number of needle insertions (4 to 12) using 11 patient MR data-sets with PTV, prostate, urethra, bladder and rectum delineated. Needle positioning errors were modeled by random normally distributed angulation errors (standard deviation of 3 mm at the needle’s tip). The final dose parameters were compared in the situations where the needle with the largest vs. the smallest dose coverage impact was selected at each insertion. Results: Over all scenarios, the percentage of clinically acceptable final dose distribution improved when the needle selected had the largest dose coverage impact (91%) compared to the smallest (88%). The differences were larger for few (4 to 6) needle insertions (maximum difference scenario: 79% vs. 60%). The computation time of the needle sequence optimization was below 60s. Conclusion: A new adaptive needle sequence determination for HDR prostate brachytherapy was developed. Coupled to adaptive planning, the selection of the needle with the largest dose coverage impact

Electrosprayed nanoparticles for drug delivery and pharmaceutical applications

Science.gov (United States)

Sridhar, Radhakrishnan; Ramakrishna, Seeram

2013-01-01

Nanotechnology based Pharma has emerged significantly and has influenced the Pharma industry up to a considerable extent. Nanoparticles technology holds a good share of the nanotech Pharma and is significant in comparison with the other domains. Electrospraying technology answers the potential needs of nanoparticle production such as scalability, reproducibility, effective encapsulation etc. Many drugs have been electrosprayed with and without polymer carriers. Drug release characteristics are improved with the incorporation of biodegradable polymer carriers which sustain the release of encapsulated drug. Electrospraying is acknowledged as an important technique for the preparation of nanoparticles with respect to pharmaceutical applications. Herein we attempted to consolidate the reports pertaining to electrospraying and their corresponding therapeutic application area. PMID:23512013

Rapid in situ detection of alkaloids in plant tissue under ambient conditions using desorption electrospray ionization.

Science.gov (United States)

Talaty, Nari; Takáts, Zoltán; Cooks, R Graham

2005-12-01

Desorption electrospray ionization (DESI) mass spectrometry is applied to the in situ detection of alkaloids in the tissue of poison hemlock (Conium maculatum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna). The experiment is carried out by electrospraying micro-droplets of solvent onto native or freshly-cut plant tissue surfaces. No sample preparation is required and the mass spectra are recorded under ambient conditions, in times of a few seconds. The impact of the sprayed droplets on the surface produces gaseous ions from organic compounds originally present in the plant tissue. The effects of operating parameters, including the electrospray high voltage, heated capillary temperature, the solvent infusion rate and the carrier gas pressure on analytical performance are evaluated and optimized. Different types of plant material are analyzed including seeds, stems, leaves, roots and flowers. All the previously reported alkaloids have been detected in C. maculatum, while fifteen out of nineteen known alkaloids for D. stramonium and the principal alkaloids of A. belladonna were also identified. All identifications were confirmed by tandem mass spectrometry. Results obtained show similar mass spectra, number of alkaloids, and signal intensities to those obtained when extraction and separation processes are performed prior to mass spectrometric analysis. Evidence is provided that DESI ionization occurs by both a gas-phase ionization process and by a droplet pick-up mechanism. Quantitative precision of DESI is compared with conventional electrospray ionization mass spectrometry (after sample workup) and the RSD values for the same set of 25 dicotyledonous C. maculatum seeds (one half of each seed analyzed by ESI and the other by DESI) are 9.8% and 5.2%, respectively.

Oxidation of ammonium sulfite by a multi-needle-to-plate gas phase pulsed corona discharge reactor

Science.gov (United States)

Ren, Hua; Lu, Na; Shang, Kefeng; Li, Jie; Wu, Yan

2013-03-01

The oxidation of ammonium sulfite in the ammonia-based flue gas desulfurization (FGD) process was investigated in a multi-needle-to-plate gas phase pulsed corona discharge reactor in this paper. The effect of several parameters, including capacitance and peak pulse voltage of discharge system, electrode gap and bubbling gas flow rate on the oxidation rate of ammonium sulfite was reviewed. The oxidation rate of ammonium sulfite could reach 47.2% at the capacitance, the peak pulse voltage, electrode gap and bubbling gas flow rate equal to 2 nF, -24.6 k V, 35 mm and 4 L min-1 within treatment time of 40 min The experimental results indicate that the gas phase pulsed discharge system with a multi-needle-to-plate electrode can oxide the ammonium sulfite. The oxidation rate increased with the applied capacitance and peak pulse voltage and decreased with the electrode gap. As the bubbling gas flow rate increased, the oxidation rate increased first and then tended to reach a stationary value. These results would be important for the process optimization of the (NH4)2SO3 to (NH4)2SO4 oxidation.

Electrospray deposition from fountain pen AFM probes

NARCIS (Netherlands)

Geerlings, J.; Sarajlic, Edin; Berenschot, Johan W.; Abelmann, Leon; Tas, Niels Roelof

2012-01-01

In this paper we present for the first time electrospraying from fountain pen probes. By using electrospray contactless deposition in an AFM setup becomes possible. Experiments on a dedicated setup were carried out as first step towards this goal. Spraying from 8 and 2 µm apertures was observed. For

[Discussion on needling sensation, arrival of qi and needling response (Deqi)].

Science.gov (United States)

Zhang, Fang; Wang, Hong-Du

2012-12-01

The current appointed teaching material of Science of Acupuncture and Moxibustion holds that there is no difference among the needling sensation, arrival of qi and needling response. However, the author has a different understanding. Therefore, Neijing (Internal Classic), its annotation, exposition and understandings of ancient and modern famous experts are cited to analyze their meanings. And the result indicates that the needling sensation is subjective feelings and perceived responses of doctors and patients. Arrival of qi is the healing process of the organ through activating the anti-pathogenic qi to expel the pathogens. The needling response is the final aim of acupuncture therapy. Thus, the meaning of needling sensation, arrival of qi, and needling response are different. And an accurate understanding can better guide acupuncture treatment.

Geographical and climatic limits of needle types of one- and two-needled pinyon pines

Science.gov (United States)

Cole, K.L.; Fisher, J.; Arundel, S.T.; Cannella, J.; Swift, S.

2008-01-01

Aim: The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy of individual pine needles rather than species. Location: Western North America. Methods: We synthesized available and new data from field and herbarium collections of needles to compile maps of their current distributions across western North America. Annual frequencies of needle types were compared with local precipitation histories for some stands. Historical North American climates were modelled on a c. 1-km grid using monthly temperature and precipitation values. A geospatial model (ClimLim), which analyses the effect of climate-modulated physiological and ecosystem processes, was used to rank the importance of seasonal climate variables in limiting the distributions of anatomical needle types. Results: The pinyon needles were classified into four distinct types based upon the number of needles per fascicle, needle thickness and the number of stomatal rows and resin canals. The individual needles fit well into four categories of needle types, whereas some trees exhibit a mixture of two needle types. Trees from central Arizona containing a mixture of Pinus edulis and fallax-type needles increased their percentage of fallax-type needles following dry years. All four needle types occupy broader geographical regions with distinctive precipitation regimes

Component analysis of a mixed beam generated by vacuum electrospray of an ionic liquid

International Nuclear Information System (INIS)

Fujiwara, Yukio; Saito, Naoaki; Nonaka, Hidehiko; Ichimura, Shingo

2012-01-01

Vacuum electrospray of a quaternary ammonium ionic liquid, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl) amide (DEME-TFSA), was investigated to develop a primary ion source for secondary ion mass spectrometry (SIMS). Since the ionic liquid contains many methyl and ethyl groups as well as protons, its beam is expected to efficiently produce protonated molecules for SIMS analysis of organic materials. Experimental results showed that the beam consisted of charged particles of m/z about 1000 and charged droplets of m/z > 10 5 . The current components of both the charged particles and droplets changed with the applied voltage and the flow rate of the ionic liquid. With decreasing flow rate, the current component of the charged droplets increased, whereas that of the charged particles decreased. The m/z values of the charged droplets diminished with decreasing flow rate and increasing capillary voltage. In addition to masses and charge numbers, the numbers of the charged droplets and the charged particles were estimated.

Relations between Scots pine needle element concentrations and decreased needle longevity along pollution gradients

International Nuclear Information System (INIS)

Lamppu, Jukka; Huttunen, Satu

2003-01-01

Deceased needle longevity was related to increased heavy metal concentrations. - Scots pine (Pinus sylvestris L.) shoots were sampled along transects near one urban pollution source and two smelters. Needle Mg, P and K concentrations decreased from the second to the fourth age class linearly with needle survival along the urban pollution gradient. Still, over 80% of the average concentration of these nutrients remained in the fourth needle age class. Decreased needle longevity was closely related to the increased heavy metal concentrations near the smelters. Near the urban pollution source, it was related to the increased annual needle mass and the increased needle nutrient concentrations. Decreased Mn accumulation along with needle age was detected near all pollution sources. Leaching of Mn from needles and especially from soil as a cause of decreased needle concentrations is discussed

Growth of ZnSe nano-needles by pulsed laser deposition and their application in polymer/inorganic hybrid solar cells

International Nuclear Information System (INIS)

Chen, L.; Lai, J.S.; Fu, X.N.; Sun, J.; Ying, Z.F.; Wu, J.D.; Lu, H.; Xu, N.

2013-01-01

Using pulsed-laser deposition method, crystalline ZnSe nano-needles have been grown on catalyst-coated silicon (100) substrates. The crystalline ZnSe nano-needles with the middle diameters of about 20–80 nm, and the lengths ranging from 100 to 600 nm can be grown densely on 300–400 °C substrates. The as-grown ZnSe nano-needles were well crystalline and base-grown. They are potential electron-capturing materials in polymer/inorganic hybrid solar cells for their properties of good electron-conductance and high ratio surface area. Based on the ZnSe nano-needle cathode, a five-layer composite structure of polymer/inorganic hybrid solar cell has been designed and fabricated. The absorption spectra of the blend of regioregular poly(3-hexylthiophene-2,5-diyl) and phenyl-C61-butyric acid methyl ester (P3HT:PCBM), ZnSe nano-needles and the combination of P3HT:PCBM and ZnSe nano-needles were examined by ultraviolet–visible-infrared spectrophotometer, respectively. The absorption bands of the combination of P3HT:PCBM and ZnSe nano-needles fit well with the solar spectral distribution. - Highlights: ► Crystalline ZnSe nano-needles grown by pulsed laser deposition. ► A five-layer polymer/inorganic hybrid solar cell based on ZnSe nano-needles cathode. ► ZnSe nano-needles improve light absorption. ► Employment of ZnSe nano-needles increase the open-circuit voltage and fill factor

Electrospray methodologies for characterization and deposition of nanoparticles

Science.gov (United States)

Modesto Lopez, Luis Balam

Electrospray is an aerosolization method that generates highly charged droplets from solutions or suspensions and, after a series of solvent evaporation -- droplet fission cycles, it results in particles carrying multiple charges. Highly charged particles are used in a variety of applications, including particle characterization, thin film deposition, nanopatterning, and inhalation studies among several others. In this work, a soft X-ray photoionization was coupled with an electrospray to obtain monodisperse, singly charged nanoparticles for applications in online size characterization with electrical mobility analysis. Photoionization with the soft X-ray charger enhanced the diffusion neutralization rate of the highly charged bacteriophages, proteins, and solid particles. The effect of nanoparticle surface charge and nanoparticle agglomeration in liquids on the electrospray process was studied experimentally and a modified expression to calculate the effective electrical conductivity of nanosuspensions was proposed. The effective electrical conductivity of TiO2 nanoparticle suspensions is strongly dependent on the electrical double layer and the agglomeration dynamics of the particles; and such dependence is more remarkable in liquids with low ionic strength. TiO2 nanoparticle agglomerates with nearly monodisperse sizes in the nanometer and submicrometer ranges were generated, by electrospraying suspensions with tuned effective electrical conductivity, and used to deposit photocatalytic films for water-splitting. Nanostructured films of iron oxide with uniform distribution of particles over the entire deposition area were formed with an electrospray system. The micro-Raman spectra of the iron oxide films showed that transverse and longitudinal optical modes are highly sensitive to the crystallize size of the electrospray-deposited films. The fabrication of films of natural light-harvesting complexes, with the aim of designing biohybrid photovoltaic devices, was

Multiplexed electrospray scaling for liquid fuel injection

International Nuclear Information System (INIS)

Waits, C Mike; Hanrahan, Brendan; Lee, Ivan

2010-01-01

Evaporation and space-charge requirements are evaluated to understand the effect of device scaling and fuel preheating for a liquid fuel injector using a multiplexed electrospray (MES) configuration in compact combustion applications. This work reveals the influence of the droplet diameter, droplet velocity and droplet surface temperature as well as the surrounding gas temperature on the size and performance of microfabricated MES. Measurements from MES devices are used in the model to accurately account for the droplet diameter versus flow rate relationship, the minimum droplet diameter and the relevant droplet velocities. A maximum extractor electrode to ground electrode distance of 3.1 mm required to overcome space-charge forces is found to be independent of voltage or droplet velocity for large levels of multiplexing. This maximum distance also becomes the required evaporation length scale which imposes minimum fuel pre-heating requirements for large flow densities. Required fuel preheating is therefore evaluated for both ethanol and 1-butanol with combustor parameters relevant to fuel reformation, thermoelectric conversion, thermophotovoltaic conversion and thermionic conversion

A new electrospray method for targeted gene delivery.

Science.gov (United States)

Boehringer, Stephan; Ruzgys, Paulius; Tamò, Luca; Šatkauskas, Saulius; Geiser, Thomas; Gazdhar, Amiq; Hradetzky, David

2018-03-05

A challenge for gene therapy is absence of safe and efficient local delivery of therapeutic genetic material. An efficient and reproducible physical method of electrospray for localized and targeted gene delivery is presented. Electrospray works on the principle of coulombs repulsion, under influence of electric field the liquid carrying genetic material is dispersed into micro droplets and is accelerated towards the targeted tissue, acting as a counter electrode. The accelerated droplets penetrate the targeted cells thus facilitating the transfer of genetic material into the cell. The work described here presents the principle of electrospray for gene delivery, the basic instrument design, and the various optimized parameters to enhance gene transfer in vitro. We estimate a transfection efficiency of up to 60% was achieved. We describe an efficient gene transfer method and a potential electrospray-mediated gene transfer mechanism.

Transbronchial needle aspiration with a new electromagnetically-tracked TBNA needle

Science.gov (United States)

Choi, Jae; Popa, Teo; Gruionu, Lucian

2009-02-01

Transbronchial needle aspiration (TBNA) is a common method used to collect tissue for diagnosis of different chest diseases and for staging lung cancer, but the procedure has technical limitations. These limitations are mostly related to the difficulty of accurately placing the biopsy needles into the target mass. Currently, pulmonologists plan TBNA by examining a number of Computed Tomography (CT) scan slices before the operation. Then, they manipulate the bronchoscope down the respiratory track and blindly direct the biopsy. Thus, the biopsy success rate is low. The diagnostic yield of TBNA is approximately 70 percent. To enhance the accuracy of TBNA, we developed a TBNA needle with a tip position that can be electromagnetically tracked. The needle was used to estimate the bronchoscope's tip position and enable the creation of corresponding virtual bronchoscopic images from a preoperative CT scan. The TBNA needle was made with a flexible catheter embedding Wang Transbronchial Histology Needle and a sensor tracked by electromagnetic field generator. We used Aurora system for electromagnetic tracking. We also constructed an image-guided research prototype system incorporating the needle and providing a user-friendly interface to assist the pulmonologist in targeting lesions. To test the feasibility of the accuracy of the newly developed electromagnetically-tracked needle, a phantom study was conducted in the interventional suite at Georgetown University Hospital. Five TBNA simulations with a custom-made phantom with a bronchial tree were performed. The experimental results show that our device has potential to enhance the accuracy of TBNA.

Mechanics of needle-tissue interaction

NARCIS (Netherlands)

Roesthuis, Roy; van Veen, Youri; Jahya, Alex; Misra, Sarthak

2011-01-01

When a needle is inserted into soft tissue, interac- tion forces are developed at the needle tip and along the needle shaft. The needle tip force is due to cutting of the tissue, and the force along the needle shaft is due to friction between needle and tissue. In this study, the friction force is

Bio-electrosprayed multicellular zebrafish embryos are viable and develop normally

International Nuclear Information System (INIS)

Clarke, Jonathan D W; Jayasinghe, Suwan N

2008-01-01

Bio-electrosprays are rapidly emerging as a viable protocol for directly engineering living cells. This communication reports the bio-electrospraying of multicellular organisms, namely zebrafish embryos. The results demonstrate that the bio-electrospray protocol fails to induce any embryological perturbations. In addition to analysing overall embryo morphology, we use transgenic embryos that express green fluorescent protein in specific brain neurons to determine that neuronal numbers and organization are completely normal. These results demonstrate that the bio-electrospraying protocol does not interfere with the complex gene regulation and cell movements required for the development of a multicellular organism. (communication)

Anti-browning and barrier properties of edible coatings prepared with electrospraying

NARCIS (Netherlands)

Khan, M.K.I.; Cakmak, I.; Tavman, S.; Schutyser, M.A.I.; Schroen, C.G.P.H.

2014-01-01

Electrospraying is a novel technique for the application of coating to foods. In this study, thin lipid-based coatings were prepared by electrospraying on model surface and evaluated for their moisture barrier functionality. Sunflower oil and chocolate based coating materials were electrosprayed at

Investigating the Effects of Three Needling Parameters (Manipulation, Retention Time, and Insertion Site) on Needling Sensation and Pain Profiles: A Study of Eight Deep Needling Interventions

Science.gov (United States)

Loyeung, Bertrand Y. K.; Cobbin, Deirdre M.

2013-01-01

Introduction. In traditional Chinese acupuncture, needle sensation (deqi) is purported to contribute to a therapeutic outcome. While researchers have attempted to define deqi qualitatively, few have examined the effects of needling parameters on its intensity. Methods. 24 healthy subjects completed eight interventions scheduled at least one week apart, which involved manual acupuncture to LI4 or a designated nonacupoint (NAP) on the hand, with real or simulated manipulation each three minutes and needle retentions of one or 21 minutes. Intensities of needling sensation and pain were reported every three minutes and sensation qualities were reported post-intervention. Results. Immediately after needle insertion, similar levels of mean needle sensation and of pain were reported independent of intervention. At subsequent measurement times, only two interventions (one at LI4 and one at NAP) maintained statistically significantly elevated needle sensation and pain scores and reported higher numbers of needle sensation descriptors. For both, the needle was retained for 21 minutes and manipulated every three minutes. Neither intervention differed significantly in terms of levels of pain, and needle sensation or numbers and qualities of needle sensation described. Conclusion. In this group of healthy subjects, the initial needling for all eight interventions elicited similar levels of needle sensation and pain. These levels were only maintained if there was ongoing of needle manipulation and retention of the needle. By contrast, the strength of needle sensation or pain experienced was independent of insertion site. PMID:24159337

Effect of needle tract bleeding on occurrence of pneumothorax after transthoracic needle biopsy

International Nuclear Information System (INIS)

Topal, U.; Berkman, Yahya M.

2005-01-01

Purpose: Occasionally bleeding along the needle trajectory is observed at post-biopsy computed tomographic sections. This study was designed to evaluate the possible effect of needle tract bleeding on the occurrence of pneumothorax and on requirement of chest tube insertion. Materials and methods: Two hundred eighty-four needle biopsies performed in 275 patients in whom the needle traversed the aerated lung parenchyma were retrospectively reviewed. Bleeding along the needle tract, occurrence of pneumothorax and need for chest tube insertion, type and size of the needle, size of the lesion, length of the lung traversed by the needle, presence or absence of emphysema were noted. Effect of these factors on the rate of pneumothorax and needle-tract bleeding was evaluated. The data were analyzed by χ 2 test. Results: Pneumothorax developed in 100 (35%) out of 284 procedures requiring chest tube placement in 16 (16%). Variables that were significantly associated with an increased risk of pneumothorax were depth of the lesion (P 0.05). However, analysis of the relation between length of lung traversed by the needle, tract-bleeding and pneumothorax rate indicated that tract-bleeding had a preventive effect on development of pneumothorax (P 0.05). Conclusion: Bleeding in the needle tract has a preventive effect on the occurrence of the pneumothorax in deep-seated lesions and in the presence of emphysema, although it does not affect the overall rate of pneumothorax

Accuracy of Core Needle Biopsy Versus Fine Needle Aspiration Cytology for Diagnosing Salivary Gland Tumors

Directory of Open Access Journals (Sweden)

In Hye Song

2015-03-01

Full Text Available Background: Core needle biopsy is a relatively new technique used to diagnose salivary gland lesions, and its role in comparison with fine needle aspiration cytology needs to be refined. Methods: We compared the results of 228 ultrasound-guided core needle biopsy and 371 fine needle aspiration procedures performed on major salivary gland tumors with their postoperative histological diagnoses. Results: Core needle biopsy resulted in significantly higher sensitivity and more accurate tumor subtyping, especially for malignant tumors, than fine needle aspiration. No patient developed major complications after core needle biopsy. Conclusions: We recommend ultrasoundguided core needle biopsy as the primary diagnostic tool for the preoperative evaluation of patients with salivary gland lesions, especially when malignancy is suspected.

Improved transvenous liver biopsy needle

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl; Matzen, P; Christoffersen, P

1979-01-01

A modified type of the standard transvenous cholangiography biopsy needle is described. The modified tranvenous liver biopsy needle caused only minimal artefactual changes of the liver biopsy specimens. The new type of biopsy needle is a modified Menghini needle. The conventional Menghini needle...... should be avoided for transvenous catheter biopsies because of risk of leaving catheter fragments in the liver....

Breakdown characteristics of electro-negative gases under needle-plane gap. Hari-hiraita gap ni okeru denkiteki fusei gas no zetsuen hakai tokusei

Energy Technology Data Exchange (ETDEWEB)

Nakayama, H.; Onoda, M.; Amakawa, K. (Himeji Institute of Technology, Hyogo (Japan)); Kuroda, S. (Nitto Denko Corp., Tokyo (Japan))

1990-07-20

The voltage-time (V-t) characteristics of corona onset and breakdown were examined in electro-negative gases as SF {sub 6} and CCl {sub 2} F {sub 2}, using a needle-plane electrode with small gap and {mu} s square pulse voltage with various wave fronts. The V-t characteristics in electro-neutral gas as N {sub 2} ordinarily descended rightwards, but those in SF {sub 6} descended rightwards only in smaller gaps and lower gas pressures. In the pulse voltage with shorter wave fronts, those in SF {sub 6} also offered a particular shape descending leftwards. The particular shape was dependent on the steepness of the pulse wave front, being strongly affected by shorter wave fronts, and also strongly related to the onset and development length of corona. The particular phenomenon of V-t characteristics was observed more obviously at a positive needle than negative one without any extremely long corona lengths at negative one, indicating a polarity effect. The phenomenon was also observed in CCl {sub 2} F {sub 2} as particular one in electro-negative gases. 21 refs., 12 figs.

Effect of Needle Size in Ultrasound-guided Core Needle Breast Biopsy: Comparison of 14-, 16-, and 18-Gauge Needles.

Science.gov (United States)

Giuliani, Michela; Rinaldi, Pierluigi; Rella, Rossella; Fabrizi, Gina; Petta, Federica; Carlino, Giorgio; Di Leone, Alba; Mulè, Antonino; Bufi, Enida; Romani, Maurizio; Belli, Paolo; Bonomo, Lorenzo

2017-11-01

The aim of the present study was to assess the diagnostic accuracy of ultrasound-guided core needle biopsy (US-CNB) of breast lesions, comparing smaller needles (16- and 18-gauge) with the 14-gauge needle, and to analyze the lesion characteristics influencing US-CNB diagnostic performance. All the patients provided informed consent before the biopsy procedure. The data from breast lesions that had undergone US-CNB in our institution from January 2011 to January 2015 were retrospectively reviewed. The inclusion criterion was the surgical histopathologic examination findings of the entire lesion or radiologic follow-up data for ≥ 24 months. The exclusion criterion was the use of preoperative neoadjuvant therapy. The US-CNB results were compared with the surgical pathologic results or with the follow-up findings in the 3 needle size groups (14-, 16-, and 18-gauge). The needle size- and lesion characteristic-specific diagnostic accuracy parameters were evaluated. Statistical analysis was performed using a dedicated software program, and P ≤ .01 was considered significant. A total of 1118 US-CNB cases (1042 patients) were included. Of the 1118 cases, 630 (56.3%) were in the 14-gauge group, 136 (12.2%) in the 16-gauge, and 352 (31.5%) in the 18-gauge needle group. Surgery was performed on 800 lesions (71.6%). Of these, 619 were malignant, 77 were high risk, and 104 were benign. The remaining 318 lesions (28.4%) underwent follow-up imaging studies. All the lesions were stable and, therefore, were considered benign. No differences were observed in the diagnostic accuracy parameters among the 3 needle size groups (P > .01). The false-negative rate was greater for lesions  .01). US-CNB performed with small needles (16 and 18 gauge) had the same diagnostic accuracy as that performed with 14-gauge needles, regardless of the lesion characteristics. Copyright © 2017 Elsevier Inc. All rights reserved.

Electro-spray of high viscous liquids for producing mono-sized spherical alginate beads

Institute of Scientific and Technical Information of China (English)

Hamid Moghadam; Mohsen Samimi; Abdolreza Samimi; Mohamad Khorram

2008-01-01

Alginate beads, often used for controlled release of enzymes and drugs, are usually produced by spraying sodium alginate liquid into a gelling agent using mechanical vibration nozzle or air jet. In this work an alternative method of electro-spray was employed to form droplets with desired size from a highly viscous sodium alginate solution using constant DC voltage. The droplets were then cured in a calcium chloride solution. The main objective was to produce mono-sized beads from such a highly viscous and non-Newtonian liquid (1000-5000 mPa s). The effects of nozzle diameter, flow rate and concentration of liquid on the size of the beads were investigated. Among the parameters studied, voltage had a pronounced effect on the size of beads as compared to flow rate zzle diameter and concentration of alginate liquid. The size of beads was reduced to a minimum value with increasing the voltage in the range of 0-10 kV. At the early stages of voltage increase (I.e. Up to about 4 kV), the rate of size reduction was relatively low, while the dripping mode dominated. However, in the middle part of the range of applied voltage, where the rate of size reduction was high (I.e. About 4-7 kV), an unstable transition occurred between dripping and jetting. At the end part of the range (I.e. 7-10 kV) jet mode of spray was observed. Increasing the height of fall of the droplets was found to improve the sphericity of the beads, because of the increased time of flight for the droplets. This was especially identifiable at higher concentrations of the alginate liquid (I.e. 3 w/v%)

Shrinking droplets in electrospray ionization and their influence on chemical equilibria.

Science.gov (United States)

Wortmann, Arno; Kistler-Momotova, Anna; Zenobi, Renato; Heine, Martin C; Wilhelm, Oliver; Pratsinis, Sotiris E

2007-03-01

We investigated how chemical equilibria are affected by the electrospray process, using simultaneous in situ measurements by laser-induced fluorescence (LIF) and phase Doppler anemometry (PDA). The motivation for this study was the increasing number of publications in which electrospray ionization mass spectrometry is used for binding constant determination. The PDA was used to monitor droplet size and velocity, whereas LIF was used to monitor fluorescent analytes within the electrospray droplets. Using acetonitrile as solvent, we found an average initial droplet diameter of 10 microm in the electrospray. The PDA allowed us to follow the evolution of these droplets down to a size of 1 microm. Rhodamine B-sulfonylchloride was used as a fluorescent analyte within the electrospray. By spatially resolved LIF it was possible to probe the dimerization equilibrium of this dye. Measurements at different spray positions showed no influence of the decreasing droplet size on the monomer-dimer equilibrium. However, with the fluorescent dye pair DCM and oxazine 1 it was shown that a concentration increase does occur within electrosprayed droplets, using fluorescence resonance energy transfer as a probe for the average pair distance.

Dynamics of translational friction in needle-tissue interaction during needle insertion.

Science.gov (United States)

Asadian, Ali; Patel, Rajni V; Kermani, Mehrdad R

2014-01-01

In this study, a distributed approach to account for dynamic friction during needle insertion in soft tissue is presented. As is well known, friction is a complex nonlinear phenomenon. It appears that classical or static models are unable to capture some of the observations made in systems subjected to significant frictional effects. In needle insertion, translational friction would be a matter of importance when the needle is very flexible, or a stop-and-rotate motion profile at low insertion velocities is implemented, and thus, the system is repeatedly transitioned from a pre-sliding to a sliding mode and vice versa. In order to characterize friction components, a distributed version of the LuGre model in the state-space representation is adopted. This method also facilitates estimating cutting force in an intra-operative manner. To evaluate the performance of the proposed family of friction models, experiments were conducted on homogeneous artificial phantoms and animal tissue. The results illustrate that our approach enables us to represent the main features of friction which is a major force component in needle-tissue interaction during needle-based interventions.

Needle phobia during pregnancy.

Science.gov (United States)

Searing, Kimberly; Baukus, Mary; Stark, Mary Ann; Morin, Karen H; Rudell, Barb

2006-01-01

The objective of this study was to understand the experience of a pregnant woman with needle phobia and examine its impact on her antepartum, intrapartum, and postpartum experience. A case study format was employed. A 21-year-old primiparous woman with diagnosed needle phobia was interviewed, and her prenatal and delivery records were reviewed. Three tasks during pregnancy were identified: seeking trusting relationships with health care providers; establishing and maintaining control and understanding; and coping with fear of needles, pain, and invasion. As frequent caregivers during childbearing, nurses with an understanding of needle phobia can help to establish trusting relationships with women with this phobia and support them and their families during childbearing and their encounters with needles. (c) 2006, AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses

Increasing Protein Charge State When Using Laser Electrospray Mass Spectrometry

Science.gov (United States)

Karki, Santosh; Flanigan, Paul M.; Perez, Johnny J.; Archer, Jieutonne J.; Levis, Robert J.

2015-05-01

Femtosecond (fs) laser vaporization is used to transfer cytochrome c, myoglobin, lysozyme, and ubiquitin from the condensed phase into an electrospray (ES) plume consisting of a mixture of a supercharging reagent, m-nitrobenzyl alcohol ( m-NBA), and trifluoroacetic acid (TFA), acetic acid (AA), or formic acid (FA). Interaction of acid-sensitive proteins like cytochrome c and myoglobin with the highly charged ES droplets resulted in a shift to higher charge states in comparison with acid-stable proteins like lysozyme and ubiquitin. Laser electrospray mass spectrometry (LEMS) measurements showed an increase in both the average charge states (Zavg) and the charge state with maximum intensity (Zmode) for acid-sensitive proteins compared with conventional electrospray ionization mass spectrometry (ESI-MS) under equivalent solvent conditions. A marked increase in ion abundance of higher charge states was observed for LEMS in comparison with conventional electrospray for cytochrome c (ranging from 19+ to 21+ versus 13+ to 16+) and myoglobin (ranging from 19+ to 26+ versus 18+ to 21+) using an ES solution containing m-NBA and TFA. LEMS measurements as a function of electrospray flow rate yielded increasing charge states with decreasing flow rates for cytochrome c and myoglobin.

Observation of electrostatically released DNA from gold electrodes with controlled threshold voltages.

Science.gov (United States)

Takeishi, Shunsaku; Rant, Ulrich; Fujiwara, Tsuyoshi; Buchholz, Karin; Usuki, Tatsuya; Arinaga, Kenji; Takemoto, Kazuya; Yamaguchi, Yoshitaka; Tornow, Marc; Fujita, Shozo; Abstreiter, Gerhard; Yokoyama, Naoki

2004-03-22

DNA oligo-nucleotides, localized at Au metal electrodes in aqueous solution, are found to be released when applying a negative bias voltage to the electrode. The release was confirmed by monitoring the intensity of the fluorescence of cyanine dyes (Cy3) linked to the 5' end of the DNA. The threshold voltage of the release changes depending on the kind of linker added to the DNA 3'-terminal. The amount of released DNA depends on the duration of the voltage pulse. Using this technique, we can retain DNA at Au electrodes or Au needles, and release the desired amount of DNA at a precise location in a target. The results suggest that DNA injection into living cells is possible with this method. (c) 2004 American Institute of Physics

[Deep needling and shallow needling at three acupoints around ear for subjective tinnitus: a randomized controlled trial].

Science.gov (United States)

Yin, Tao; Ni, Jinxia; Zhu, Wenzeng

2015-10-01

To compare the effective differences between deep needling and shallow needling at three acupoints around ear for subjective tinnitus. Fifty patients with subjective tinnitus were randomized divided into a deep needling group and a shallow needling group, 25 cases in each group. Twenty-two patients in the deep needling group and 20 patients in the shallow needling group were brought into statistic in the end. In the two groups, the three acupoints around ear and distal acupoints were both selected. The acupoints of the affected side such as Yifeng (TE 17), Tinghui (GB 2), Ermen (TE 21), Zhigou (TE 6), Zhongzhu (TE 3) and Hegu (LI 4) were adopted. Yifeng (TE 17), Tinghui (GB 2) and Ermen (TE 21) were acupunctured 30-38 mm in the deep needling group and 15-20 mm in the shallow needling group. The other acupoints were conventionally acupunctured in the two groups. The needles were retained for 30 min,once a day and five times a week for all patients. The treatment was continuously for 4 weeks in the two groups. Tinnitus handicap inventory (THI) scores, tinnitus grades and visual analogue scale (VAS) for tinnitus sound levels were observed before and after treatment, and the effects of the two groups were compared. The total effective rate in the deep needling group was 59.1% (13/22), and it was better than 20.0% (4/20) in the shallow needling group (P deep needling, group, the THI score, tinnitus grade and the VAS score were improved than those before treatment (all P shallow needling group, the three above indices before and after treatment were not different in statistical significance (all P > 0.05). After treatment, all the three indices in the deep needling group were superior to those in the shallow needling group (all P shallow needling at the three acupoints.

Needle bar for warp knitting machines

Science.gov (United States)

Hagel, Adolf; Thumling, Manfred

1979-01-01

Needle bar for warp knitting machines with a number of needles individually set into slits of the bar and having shafts cranked to such an extent that the head section of each needle is in alignment with the shaft section accommodated by the slit. Slackening of the needles will thus not influence the needle spacing.

Process engineering of high voltage alginate encapsulation of mesenchymal stem cells

International Nuclear Information System (INIS)

Gryshkov, Oleksandr; Pogozhykh, Denys; Zernetsch, Holger; Hofmann, Nicola; Mueller, Thomas; Glasmacher, Birgit

2014-01-01

Encapsulation of stem cells in alginate beads is promising as a sophisticated drug delivery system in treatment of a wide range of acute and chronic diseases. However, common use of air flow encapsulation of cells in alginate beads fails to produce beads with narrow size distribution, intact spherical structure and controllable sizes that can be scaled up. Here we show that high voltage encapsulation (≥ 15 kV) can be used to reproducibly generate spherical alginate beads (200–400 μm) with narrow size distribution (± 5–7%) in a controlled manner under optimized process parameters. Flow rate of alginate solution ranged from 0.5 to 10 ml/h allowed producing alginate beads with a size of 320 and 350 μm respectively, suggesting that this approach can be scaled up. Moreover, we found that applied voltages (15–25 kV) did not alter the viability and proliferation of encapsulated mesenchymal stem cells post-encapsulation and cryopreservation as compared to air flow. We are the first who employed a comparative analysis of electro-spraying and air flow encapsulation to study the effect of high voltage on alginate encapsulated cells. This report provides background in application of high voltage to encapsulate living cells for further medical purposes. Long-term comparison and work on alginate–cell interaction within these structures will be forthcoming. - Highlights: • High voltage alginate encapsulation of mesenchymal stem cells (MSCs) was designed. • Reproducible and spherical alginate beads were generated via high voltage. • Air flow encapsulation was utilized as a comparative approach to high voltage. • High voltage did not alter the viability and proliferation of encapsulated MSCs. • High voltage encapsulation can be scaled up and applied in cell-based therapy

Using insulin pen needles up to five times does not affect needle tip shape nor increase pain intensity.

Science.gov (United States)

Puder, Jardena J; Atar, Michael; Muller, Beat; Pavan, Marco; Keller, Ulrich

2005-02-01

Reusing insulin pen needles could help to reduce the increasing economic burden of diabetes. We tested the hypothesis that reusing insulin pen needles leads to needle tip deformity and increased pain. Three blinded reviewers assessed 123 electron microscope pictures analyzing needle tip deformity of insulin pen needles used up to four times by diabetic subjects and up to five times by blinded non-diabetic volunteers. The estimated frequency of needle use was correlated to the actual number of needle use. Pain intensity and unpleasantness of each injection were measured by a visual analogue scale and their differences analyzed by Kruskal-Wallis analysis of variance. Unused needles could be differentiated visually from used needles. However, there was no correlation between the actual and guessed number of times a needle was used (r = 0.07, P = 0.2). Evaluating all 270 injections, neither pain intensity nor unpleasantness increased with repeated injections of the same needles in people with diabetes (P = 0.1 and 0.96) and in the volunteers (P = 0.63 and 0.92). Using pen needles four to five times does not lead to progressive needle tip deformity and does not increase pain intensity or unpleasantness, but could increase convenience and lead to substantial financial savings in Europe of around EUR 100 million/year.

Brachytherapy needle deflection evaluation and correction

International Nuclear Information System (INIS)

Wan Gang; Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

2005-01-01

In prostate brachytherapy, an 18-gauge needle is used to implant radioactive seeds. This thin needle can be deflected from the preplanned trajectory in the prostate, potentially resulting in a suboptimum dose pattern and at times requiring repeated needle insertion to achieve optimal dosimetry. In this paper, we report on the evaluation of brachytherapy needle deflection and bending in test phantoms and two approaches to overcome the problem. First we tested the relationship between needle deflection and insertion depth as well as whether needle bending occurred. Targeting accuracy was tested by inserting a brachytherapy needle to target 16 points in chicken tissue phantoms. By implanting dummy seeds into chicken tissue phantoms under 3D ultrasound guidance, the overall accuracy of seed implantation was determined. We evaluated methods to overcome brachytherapy needle deflection with three different insertion methods: constant orientation, constant rotation, and orientation reversal at half of the insertion depth. Our results showed that needle deflection is linear with needle insertion depth, and that no noticeable bending occurs with needle insertion into the tissue and agar phantoms. A 3D principal component analysis was performed to obtain the population distribution of needle tip and seed position relative to the target positions. Our results showed that with the constant orientation insertion method, the mean needle targeting error was 2.8 mm and the mean seed implantation error was 2.9 mm. Using the constant rotation and orientation reversal at half insertion depth methods, the deflection error was reduced. The mean needle targeting errors were 0.8 and 1.2 mm for the constant rotation and orientation reversal methods, respectively, and the seed implantation errors were 0.9 and 1.5 mm for constant rotation insertion and orientation reversal methods, respectively

Direct profiling of phytochemicals in tulip tissues and in vivo monitoring of the change of carbohydrate content in tulip bulbs by probe electrospray ionization mass spectrometry.

Science.gov (United States)

Yu, Zhan; Chen, Lee Chuin; Suzuki, Hiroaki; Ariyada, Osamu; Erra-Balsells, Rosa; Nonami, Hiroshi; Hiraoka, Kenzo

2009-12-01

Probe electrospray ionization (PESI) is a recently developed ESI-based ionization technique which generates electrospray from the tip of a solid needle. In this study, we have applied PESI interfaced with a time of flight mass spectrometer (TOF-MS) for direct profiling of phytochemicals in a section of a tulip bulb in different regions, including basal plate, outer and inner rims of scale, flower bud and foliage leaves. Different parts of tulip petals and leaves have also been investigated. Carbohydrates, amino acids and other phytochemicals were detected. A series of in vivo PESI-MS experiments were carried out on the second outermost scales of four living tulip bulbs to monitoring the change of carbohydrate content during the first week of initial growth. The breakdown of carbohydrates was observed which was in accordance with previous reports achieved by other techniques. This study has indicated that PESI-MS can be used for rapid and direct analysis of phytochemicals in living biological systems with advantages of low sample consumption and little sample preparation. Therefore, PESI-MS can be a new choice for direct analysis/profiling of bioactive compounds or monitoring metabolic changes in living biological systems.

Ultrasound-guided fine needle aspiration versus core needle biopsy: comparison of post-biopsy hematoma rates and risk factors.

Science.gov (United States)

Chae, In Hye; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Park, Vivian Y; Kwak, Jin Young

2017-07-01

To compare post-biopsy hematoma rates between ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy, and to investigate risk factors for post-biopsy hematoma. A total of 5304 thyroid nodules which underwent ultrasound guided biopsy were included in this retrospective study. We compared clinical and US features between patients with and without post-biopsy hematoma. Associations between these features and post-biopsy hematoma were analyzed. Post-biopsy hematoma rate was 0.8% (43/5121) for ultrasound guided-fine needle aspiration and 4.9% (9/183) for ultrasound guided-core needle biopsy (P core needle biopsy (9/179, 5.0%) than with ultrasound guided-fine needle aspiration (9/1138, 0.8%) (P core needle biopsy was the only significant risk factor for post-biopsy hematoma (adjusted Odds Ratio, 6.458, P core needle biopsy than in ultrasound guided-fine needle aspiration and ultrasound guided-core needle biopsy was the only independent factor of post-biopsy hematoma in thyroid nodules.

Low pressure electrospray ionization system and process for effective transmission of ions

Science.gov (United States)

Tang, Keqi [Richland, WA; Page, Jason S [Kennewick, WA; Kelly, Ryan T [Wet Richland, WA; Smith, Richard D [Richland, WA

2010-03-02

A system and method are disclosed that provide up to complete transmission of ions between coupled stages with low effective ion losses. A novel "interfaceless" electrospray ionization system is further described that operates the electrospray at a reduced pressure such that standard electrospray sample solutions can be directly sprayed into an electrodynamic ion funnel which provides ion focusing and transmission of ions into a mass analyzer.

Capillary filling of miniaturized sources for electrospray mass spectrometry

International Nuclear Information System (INIS)

Arscott, Steve; Gaudet, Matthieu; Brinkmann, Martin; Ashcroft, Alison E; Blossey, Ralf

2006-01-01

Capillary slot-based emitter tips are a novel tool for use in electrospray ionization-mass spectrometry of large biomolecules. We have performed a combined theoretical and experimental study of capillary filling in micron-sized slots with the aim of developing a rational design procedure for miniaturized electrospray sources, ultimately enabling the integration of ESI into laboratory-on-a-chip devices

Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

International Nuclear Information System (INIS)

Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo

2007-01-01

The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm 2 at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode

A novel method for bacterial inactivation using electrosprayed water nanostructures

International Nuclear Information System (INIS)

Pyrgiotakis, Georgios; McDevitt, James; Yamauchi, Toshiyuki; Demokritou, Philip

2012-01-01

This is a study focusing on the potential to deactivate biological agents (bacteria and endospores) using engineered water nanostructures (EWNS). The EWNS were generated using an electrospray device that collects water by condensing atmospheric water vapor on a Peltier-cooled electrode. A high voltage is applied between the collection electrode and a grounded electrode resulting in aerosolization of the condensed water and a constant generation of EWNS. Gram-negative Serratia marcescens, gram-positive Staphylococcus aureus, and Bacillusatrophaeus endospores were placed on stainless steel coupons and exposed to generated EWNS at multiple time intervals. Upon exposures, the bacteria were recovered and placed on nutrient agar to grow, and the colony forming units were counted. Ozone levels as well as air temperature and relative humidity were monitored during the experiments. Qualitative confirmation of bacterial destruction was also obtained by transmission electron microscopy. In addition, important EWNS aerosol properties such as particle number concentration as a function of size as well as the average surface charge of the generated EWNS were measured using real-time instrumentation. It was shown that the novel electrospray method can generate over time a constant flux of EWNS. EWNS have a peak number concentration of ∼8,000 particles per cubic centimeter with a modal peak size around 20 nm. The average surface charge of the generated EWNS was found to be 10 ± 2 electrons per particle. In addition, it was shown that the EWNS have the potential to deactivate both bacteria types from surfaces. At the same administrate dose, however, the endospores were not inactivated. This novel method and the unique properties of the generated EWNS could potentially be used to develop an effective, environmentally friendly, and inexpensive method for bacteria inactivation.

A novel method for bacterial inactivation using electrosprayed water nanostructures

Energy Technology Data Exchange (ETDEWEB)

Pyrgiotakis, Georgios, E-mail: gpyrgiot@hsph.harvard.edu; McDevitt, James [Harvard School of Public Health, Center for Nanotechnology and Nanotoxicology (United States); Yamauchi, Toshiyuki [Panasonic Corporation, Appliances Company (Japan); Demokritou, Philip [Harvard School of Public Health, Center for Nanotechnology and Nanotoxicology (United States)

2012-08-15

This is a study focusing on the potential to deactivate biological agents (bacteria and endospores) using engineered water nanostructures (EWNS). The EWNS were generated using an electrospray device that collects water by condensing atmospheric water vapor on a Peltier-cooled electrode. A high voltage is applied between the collection electrode and a grounded electrode resulting in aerosolization of the condensed water and a constant generation of EWNS. Gram-negative Serratia marcescens, gram-positive Staphylococcus aureus, and Bacillusatrophaeus endospores were placed on stainless steel coupons and exposed to generated EWNS at multiple time intervals. Upon exposures, the bacteria were recovered and placed on nutrient agar to grow, and the colony forming units were counted. Ozone levels as well as air temperature and relative humidity were monitored during the experiments. Qualitative confirmation of bacterial destruction was also obtained by transmission electron microscopy. In addition, important EWNS aerosol properties such as particle number concentration as a function of size as well as the average surface charge of the generated EWNS were measured using real-time instrumentation. It was shown that the novel electrospray method can generate over time a constant flux of EWNS. EWNS have a peak number concentration of {approx}8,000 particles per cubic centimeter with a modal peak size around 20 nm. The average surface charge of the generated EWNS was found to be 10 {+-} 2 electrons per particle. In addition, it was shown that the EWNS have the potential to deactivate both bacteria types from surfaces. At the same administrate dose, however, the endospores were not inactivated. This novel method and the unique properties of the generated EWNS could potentially be used to develop an effective, environmentally friendly, and inexpensive method for bacteria inactivation.

Obtaining Thickness-Limited Electrospray Deposition for 3D Coating.

Science.gov (United States)

Lei, Lin; Kovacevich, Dylan A; Nitzsche, Michael P; Ryu, Jihyun; Al-Marzoki, Kutaiba; Rodriguez, Gabriela; Klein, Lisa C; Jitianu, Andrei; Singer, Jonathan P

2018-04-04

Electrospray processing utilizes the balance of electrostatic forces and surface tension within a charged spray to produce charged microdroplets with a narrow dispersion in size. In electrospray deposition, each droplet carries a small quantity of suspended material to a target substrate. Past electrospray deposition results fall into two major categories: (1) continuous spray of films onto conducting substrates and (2) spray of isolated droplets onto insulating substrates. A crossover regime, or a self-limited spray, has only been limitedly observed in the spray of insulating materials onto conductive substrates. In such sprays, a limiting thickness emerges, where the accumulation of charge repels further spray. In this study, we examined the parametric spray of several glassy polymers to both categorize past electrospray deposition results and uncover the critical parameters for thickness-limited sprays. The key parameters for determining the limiting thickness were (1) field strength and (2) spray temperature, related to (i) the necessary repulsive field and (ii) the ability for the deposited materials to swell in the carrier solvent vapor and redistribute charge. These control mechanisms can be applied to the uniform or controllably-varied microscale coating of complex three-dimensional objects.

21 CFR 880.5580 - Acupuncture needle.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle. The...

Pulsed-voltage atom probe tomography of low conductivity and insulator materials by application of ultrathin metallic coating on nanoscale specimen geometry.

Science.gov (United States)

Adineh, Vahid R; Marceau, Ross K W; Chen, Yu; Si, Kae J; Velkov, Tony; Cheng, Wenlong; Li, Jian; Fu, Jing

2017-10-01

We present a novel approach for analysis of low-conductivity and insulating materials with conventional pulsed-voltage atom probe tomography (APT), by incorporating an ultrathin metallic coating on focused ion beam prepared needle-shaped specimens. Finite element electrostatic simulations of coated atom probe specimens were performed, which suggest remarkable improvement in uniform voltage distribution and subsequent field evaporation of the insulated samples with a metallic coating of approximately 10nm thickness. Using design of experiment technique, an experimental investigation was performed to study physical vapor deposition coating of needle specimens with end tip radii less than 100nm. The final geometries of the coated APT specimens were characterized with high-resolution scanning electron microscopy and transmission electron microscopy, and an empirical model was proposed to determine the optimal coating thickness for a given specimen size. The optimal coating strategy was applied to APT specimens of resin embedded Au nanospheres. Results demonstrate that the optimal coating strategy allows unique pulsed-voltage atom probe analysis and 3D imaging of biological and insulated samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect and safety of deep needling and shallow needling for functional constipation: a multicenter, randomized controlled trial.

Science.gov (United States)

Wu, Jiani; Liu, Baoyan; Li, Ning; Sun, Jianhua; Wang, Lingling; Wang, Liping; Cai, Yuying; Ye, Yongming; Liu, Jun; Wang, Yang; Liu, Zhishun

2014-12-01

Aupuncture is widely used for functional constipation. Effect of acupuncture might be related to the depth of needling; however, the evidence is limited. This trial aimed to evaluate the effect and safety of deep needling and shallow needling for functional constipation, and to assess if the deep needling and shallow needling are superior to lactulose. We conducted a prospective, superiority-design, 5-center, 3-arm randomized controlled trial. A total of 475 patients with functional constipation were randomized to the deep needling group (237), shallow needling group (119), and lactulose-controlled group (119) in a ratio of 2:1:1. Sessions lasted 30 minutes each time and took place 5 times a week for 4 weeks in 2 acupuncture groups. Participants in the lactulose group took lactulose orally for 16 continuous weeks. The primary outcome was the change from baseline of mean weekly spontaneous bowel movements (SBMs) during week 1 to 4 (changes from the baselines of the weekly SBMs at week 8 and week 16 in follow-up period were also assessed simultaneously). Secondary outcomes were the weekly SBMs of each assessing week, the mean score change from the baseline of constipation-related symptoms over week 1 to 4, and the time to the first SBM. Emergency drug usage and adverse effects were monitored throughout the study.SBMs and constipation-related symptoms were all improved in the 3 groups compared with baseline at each time frame (Pdeep needling group, 2 (1.75) in the shallow needling group, and 2 (2) in the lactulose group (P>0.05, both compared with the lactulose group). The changes of mean weekly SBMs at week 8 and week 16 in the follow-up period were 2 (2), 2 (2.5) in the deep needling group, 2 (3), 1.5 (2.5) in the shallow needling group, and 1 (2), 1 (2) in the lactulose group (Pdeep or shallow needling group. Deep and shallow needling at Tianshu (ST25) can improve intestinal function remarkably and safely. Therapeutic effects of deep and shallow needling are not

[Stiletto needle and needle-knife for influence of gravity index in treating knee osteoarthritis].

Science.gov (United States)

Gu, Li-Jun; Zhang, Bin; Li, Wen-Hua; Tang, Yan; Dong, Fu-Hui

2017-12-25

To explore stiletto needle and needle-knife for influence of double sufficient weight in treating knee osteoarthritis patients. One hundred and thirteen early and medium term knee osteoarthritis patients were randomly divided into three groups, including stiletto needle group(38 cases), needle-knife group (38 cases) and voltaren group (37 cases). In stiletto needle group, there were 13 males and 25 females with an average of(55.87±7.72) years old, treated by stiletto needle once a week, and 2 weeks were a course; there were 11 males and 27 females in needle-knife group with an average of(57.11±7.07) years old, treated by acupotome once a week, and 2 weeks were a course; there were 12 males and 25 females in voltaren group with an average age of(57.62±8.08) years old, treated by votalin emulsion smearing 3 to 5 cm on painful area of knee joint, three times a day for 2 weeks; 36 patients in normal group, including 11 males and 25 females with a mean age of (55.28±7.55) years old, treated with nothing. Gravitational four lattice used to measure bipedal back and forth load before and after treatment in further observe weight-bearing situation among three groups, d value, which was the distance from center of gravity to original point, was measured as a obvervational index, JOA score was used to evaluate clinical effect. Five patients were fall out, including 2 patients in stiletto needle group, 2 patients in needle-knife group and 1 patient in voltaren group. Other 108 patients were followed-up from 28 to 35 d with an average of 30 d, and without untoward effect. There was significant difference in d value between treatment group and control group at 1 month after treatment( P 0.05), and d value was decreased before treatment than that of after treatment. There was no significant difference in JOA score among treatment group after treatment at 1 month( P 0.05) after treatment at 1 month. Stiletto needle, needle-knife and voltaren for the treatment of knee

[Effects of slow twisting needle insertion and tubing needle insertion at Neiguan (PC 6) on cardiovascular function: a comparative study].

Science.gov (United States)

Ning, Shaoli; Zhao, Lihua; Xu, Lingjun; Huang, Yu; Pang, Yong; Huang, Dingjian

2016-01-01

To compare the effects between slow twisting needle insertion and tubing needle insertion. With cross-over design, 100 healthy young subjects (half male and half female) aged from 19 to 23 years were randomly divided into two groups by random digital table, 50 cases in each one. At the first stage, subjects in the group A were treated with slow twisting needle insertion while, subjects in,the group B were treated with tubing needle insertion. One week later, the procedure of second stage was performed alternately. The needle was inserted into Neiguan (PC 6) with two methods by one acupuncturist. The needle was retained for 5 min before removal. Five min before needle insertion as well as needle withdrawal and 30 min after needle withdrawal, ZXG-E automatic cardiovascular diagnostic apparatus was used to test cardiovascular function. At the tim of needle withdrawal, slow twisting needle insertion could improve effect work of kinetics (EWK), effective blood volume (BV) and reduce elastic expansion coefficient of blood vessel (FEK) and left ventricular spray blood impedance (VER), which was significantly different from tubing needle insertion (all P 0.05). The slow twisting needle insertion is significantly superior to tubing needle insertion on lowering vascular tension and VER, improving EWK and BV.

[Design and application of silver needle-knife].

Science.gov (United States)

Sun, Guodong; Shi, Bin; Zhang, Benwu; Xu, Haidong

2015-04-01

A silver needle-knife which has the dual function of silver needle and needle-knife is designed. The main components of this silver needle-knife are approximately 50% silver and approximately 50% nichrome. The silver needle-knife is composed of five parts, including needle-knife tail, spiral handle; steering handle, needle-knife body and needle-knife edge. It converges the advantages of needle-knife and silver needle, which can cut loose of diseased tissue and peel adhesion of lesions, but also be heated with moxa cone and thermal therapeutic instrument, and connect with electroacupuncture apparatus. It has the function of warming channel and removing coldness, dispelling wind and eliminating dampness, resolving spasm and relieving pain, dredging the channel and so on. Due to the spiral handle and the steering handle, the operation is easier, which reduces the blindness of cutting and increase the safety. It is mainly used for soft tissue injury, rheumatism and rheumatoid arthritis, as well as degenerative diseases of spine and joint, and it has obvious efficacy on some internal medical diseases.

CT-guided transthoracic cutting needle biopsy of intrathoracic lesions: Comparison between coaxial and single needle technique

International Nuclear Information System (INIS)

Wu, Reng-Hong; Tzeng, Wen-Sheng; Lee, Wei-Jing; Chang, Shih-Chin; Chen, Chia-Huei; Fung, Jui-Lung; Wang, Yen-Jen; Mak, Chee-Wai

2012-01-01

Purpose: To evaluate the complication rates and diagnostic accuracy of two different CT-guided transthoracic cutting needle biopsy techniques: coaxial method and single needle method. Methods: This study involved 198 consecutive subjects with 198 intrathoracic lesions. The first 98 consecutive subjects received a single needle cutting technique and the next 100 consecutive subjects received a coaxial technique. Both groups were compared in relation the diagnostic accuracy and complication rates. Results: No significant difference was found between the two groups concerning patient characteristics, lesions and procedure variables. There was a borderline statistical difference in the incidence of pneumothorax at within 24-h post biopsy between patients in the single needle group (5%) and the coaxial group (13%) (P = 0.053). Little difference was found in the pneumothorax rate at immediately post biopsy between the two groups, which was 28% in the single needle group and 31% in the coaxial group. There was no significant difference in the hemoptysis rate between the two groups, which was 9.2% in the single needle group and 11% in the coaxial group. Both techniques yielded an overall diagnostic accuracy of 98% for malignant lesions with similar sensitivity (single needle: 96.9% vs. coaxial: 96.4%) and specificity (single needle: 100% vs. coaxial: 100%). Conclusion: There is little difference in the pneumothorax rates and bleeding complications between patients who either received a single needle or a coaxial transthoracic cutting biopsy. Both techniques produce an overall diagnostic accuracy of 98% for malignant lesions.

Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

International Nuclear Information System (INIS)

Kuang Yuanwen; Wen Dazhi; Zhou Guoyi; Liu Shizhong

2007-01-01

Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants

Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

Energy Technology Data Exchange (ETDEWEB)

Kuang Yuanwen [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: kuangyw@scbg.ac.cn; Wen Dazhi [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: dzwen@scbg.ac.cn; Zhou Guoyi [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: gyzhou@scbg.ac.cn; Liu Shizhong [Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: lsz@scbg.ac.cn

2007-01-15

Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants.

Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

Energy Technology Data Exchange (ETDEWEB)

Kuang Yuanwen [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: kuangyw@scbg.ac.cn; Wen Dazhi [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: dzwen@scbg.ac.cn; Zhou Guoyi [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: gyzhou@scbg.ac.cn; Liu Shizhong [South China Botanical Garden, Chinese Academy of Sciences, 510650 Guangzhou (China)]. E-mail: lsz@scbg.ac.cn

2007-02-15

Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants.

Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

International Nuclear Information System (INIS)

Kuang Yuanwen; Wen Dazhi; Zhou Guoyi; Liu Shizhong

2007-01-01

Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. - Pine needle sections as bioindicator for heavy metals and nutrient deficiency particularly needle sheath for particle pollutants

Effects of different needles and substrates on CuInS{sub 2} deposited by electrostatic spray deposition

Energy Technology Data Exchange (ETDEWEB)

Roncallo, S. [Centre for Materials Science and Engineering, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Painter, J.D., E-mail: j.d.painter@cranfield.ac.u [Centre for Materials Science and Engineering, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Healy, M.J.F. [Centre for Materials Science and Engineering, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Ritchie, S.A.; Finnis, M.V. [Department of Engineering Systems and Management, Cranfield University, Shrivenham, Swindon SN6 8LA (United Kingdom); Rogers, K.D. [Cranfield Health, Cranfield University, Cranfield, Bedfordshire, MK43 0AL (United Kingdom); Scragg, J.J. [University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom); Dale, P.J. [Laboratoire Photovoltaique, University of Luxembourg, 41 Rue du Brill, L-4422, Belvaux (Luxembourg); Zoppi, G. [Northumbria Photovoltaics Applications Centre, Northumbria, University, Newcastle upon Tyne NE1 8ST (United Kingdom)

2011-03-31

Copper indium disulphide (CuInS{sub 2}) thin films were deposited using the electrostatic spray deposition method. The effects of applied voltage and solution flow rate on the aerosol cone shape, film composition, surface morphology and current conversion were investigated. The effect of aluminium substrates and transparent fluorine doped tin oxide (SnO{sub 2}:F) coated glass substrates on the properties of as-deposited CuInS{sub 2} films were analysed. An oxidation process occurs during the deposition onto the metallic substrates which forms an insulating layer between the photoactive film and substrate. The effects of two different spray needles on the properties of the as-deposited films were also studied. The results reveal that the use of a stainless steel needle results in contamination of the film due to the transfer of metal impurities through the spray whilst this is not seen for the glass needle. The films were characterised using a number of different analytical techniques such as X-ray diffraction, scanning electron microscopy, Rutherford back-scattering and secondary ion mass spectroscopy and opto-electronic measurements.

Molecular ordering of spin-coated and electrosprayed P3HT:PCBM thin films and their applications to photovoltaic cell

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Takeshi, E-mail: fukuda@fms.saitama-u.ac.jp [Department of Functional Materials Science, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Toda, Asuki; Takahira, Kazuya; Suzuki, Katsumi [Department of Functional Materials Science, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Liao, Yingjie [CERMAV-CNRS, UPR5301 & Grenoble Alpes University, 601 rue de la Chimie, BP53, 38041 Grenoble Cedex 9 (France); Hirahara, Miru [Department of Functional Materials Science, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Saito, Masahiko; Osaka, Itaru [Emergent Molecular Function Research Group, RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198 (Japan)

2016-08-01

Poly(3-hexylthiophene-2,5-diyl) (P3HT) is one of the most popular donor polymers for organic photovoltaic cells; however, annealing-induced molecular ordering is necessary for realizing high photoconversion efficiency. In this study, the ratio of ordered-disordered P3HT Raman signals was calculated as the crystallinity parameter, which can be evaluated as the molecular ordering of P3HT. In the case of spin-coated devices, the crystallinity parameter increases with increasing annealing temperature, and this agrees with the photovoltaic performance. Furthermore, the direct molecular ordering of P3HT during electrospray deposition is reported, detailing the relation between the solvent evaporation time and the crystallinity of P3HT, and is evaluated by Raman spectroscopy and grazing incidence X-ray diffraction. To observe the solvent evaporation phenomena of the electropsray process, in situ measurement of solvent evaporation time was also successfully realized for the first time by placing a CCD camera below the substrate in electrospray deposition. The solvent evaporation time was controlled from 0.036 to 2.8 s by changing the applied voltage and solvent. By investigating the relationship between the solvent evaporation time and the molecular ordering of P3HT, the long solvent evaporation time caused the high crystallinity of P3HT. In addition, the population of P3HT crystallinity with an edge-on orientation also increased with increasing solvent evaporation time by evaluating the grazing incidence X-ray diffraction pattern, in good agreement with the estimated crystallinity from Raman spectroscopy. Finally, a photoconversion efficiency of 2.0% was achieved by electrospray deposition without post thermal annealing. - Highlights: • An orientation of P3HT was controlled due to the solvent evaporation time. • A solvent evaporation time was evaluated for the electrospray deposition. • A crystallinity parameter was evaluated from the Raman spectroscopy. • X

Comparison of specimen adequacy in fine needle aspiration cytology performed with different gauge needles in palpable external swellings

International Nuclear Information System (INIS)

Sarfraz, T.; Bashir, S.; Tariq, H.; Malik, T.M.

2013-01-01

Background: Fine Needle Aspiration Cytology (FNAC) of external swellings may yield different specimen adequacy depending on different gauge needles used for aspiration. Objective: To compare the specimen adequacy aspirated by various gauge (21 and 22) needles in external palpable swellings of lymph nodes, thyroid gland, salivary glands, breast and soft tissue. Study Design: Comparative cross sectional study. Duration: Six months (1st Jan 2012 to 30th June 2012). Setting: Histopathology/Cytology department Combined Military Hospital Peshawar (Pakistan). Methodology: This was a prospective study of 200 cases in which FNAC was performed with either 21 or 22 gauge needles (100 cases with 21 gauge and 100 with 22 gauge needles). Equal number of aspirations were done with 21 and 22 gauge needles from the swellings of thyroid gland, lymph nodes, salivary glands, breast and soft tissue. Results were analyzed for specimen adequacy by using SPSS 17. Results: A total number of 200 cases were recruited in this study, out of which 100 were aspirated with 21 gauge needles and 100 with 22 gauge needles. Specimen adequacy in swellings of thyroid, lymph nodes and salivary glands was better with 22 gauge amounting 90%, 80% and 80% respectively, as compared to yield with 21 gauge needles which was 85%, 70% and 60% respectively. On the other hand in swellings of breast and soft tissue, the specimen adequacy was better with 21 gauge needles giving 98% and 90 % adequate yield respectively as compared to 22 gauge needles which was 70% and 40 % respectively. Conclusion: Needles of smaller gauge (22 gauge) give a better yield in swellings of thyroid, lymph nodes and salivary gland while in swellings of breast and soft tissue sample adequacy is better with larger gauge needle (21 gauge). (author)

Arterial puncture using insulin needle is less painful than with standard needle: a randomized crossover study.

Science.gov (United States)

Ibrahim, Irwani; Yau, Ying Wei; Ong, Lizhen; Chan, Yiong Huak; Kuan, Win Sen

2015-03-01

Arterial punctures are important procedures performed by emergency physicians in the assessment of ill patients. However, arterial punctures are painful and can create anxiety and needle phobia in patients. The pain score of radial arterial punctures were compared between the insulin needle and the standard 23-gauge hypodermic needle. In a randomized controlled crossover design, healthy volunteers were recruited to undergo bilateral radial arterial punctures. They were assigned to receive either the insulin or the standard needle as the first puncture, using blocked randomization. The primary outcome was the pain score measured on a 100-mm visual analogue scale (VAS) for pain, and secondary outcomes were rate of hemolysis, mean potassium values, and procedural complications immediately and 24 hours postprocedure. Fifty healthy volunteers were included in the study. The mean (±standard deviation) VAS score in punctures with the insulin needle was lower than the standard needle (23 ± 22 mm vs. 39 ± 24 mm; mean difference = -15 mm; 95% confidence interval = -22 mm to -7 mm; p standard needle (31.3% vs. 11.6%, p = 0.035; and 4.6 ±0.7 mmol/L vs. 4.2 ±0.5 mmol/L, p = 0.002). Procedural complications were lower in punctures with the insulin needle both immediately postprocedure (0% vs. 24%; p standard needles. However, due to the higher rate of hemolysis, its use should be limited to conditions that do not require a concurrent potassium value in the same blood sample. © 2015 by the Society for Academic Emergency Medicine.

An Investigation of Chemical Landscapes in Aqueous Electrosprays by Tracking Oligomerization of Isoprene

KAUST Repository

Junior, Adair Gallo

2017-12-01

Electrospray ionization mass spectrometry (ESIMS) is widely used to characterize neutral and ionic species in solvents. Typically, electrical, thermal, and pneumatic potentials are applied to create electrosprays from which charged ionic species are ejected for downstream analysis by mass spectrometry. Most recently, ESIMS has been exploited to investigate ambient proton transfer reactions at air-water interfaces in real time. We assessed the validity of these experiments via complementary laboratory experiments. Specifically, we characterized the products of two reaction scenarios via ESIMS and proton nuclear magnetic resonance (1H-NMR): (i) emulsions of pH-adjusted water and isoprene (C5H8) that were mechanically agitated, and (ii) electrosprays of pH-adjusted water that were collided with gas-phase isoprene. Our experiments unambiguously demonstrate that, while isoprene does not oligomerize in emulsions, it does undergo protonation and oligomerization in electrosprays, both with and without pH-adjusted water, confirming that C-C bonds form along myriad high-energy pathways during electrospray ionization. We also compared our experimental results with some quantum mechanics simulations of isoprene molecules interacting with hydronium at different hydration levels (gas versus liquid phase). In agreement with our experiments, the kinetic barriers to protonation and oligomerization of isoprene were inaccessible under ambient conditions. Rather, the gas-phase chemistries during electrospray ionization drove the oligomerization of isoprene. Therefore, we consider that ESIMS could induce artifacts in interfacial reactions. These findings warrant a reassessment of previous reports on tracking chemistries under ambient conditions at liquid-vapor interfaces via ESIMS. Further, we took some high-speed images of electrosprays where it was possible to observe the main characteristics of the phenomena, i.e. Taylor cone, charge separation, and Coulomb fission. Finally, we took

Design, construction and performance of a portable handheld electrohydrodynamic multi-needle spray gun for biomedical applications.

Science.gov (United States)

Sofokleous, Panagiotis; Stride, Eleanor; Bonfield, William; Edirisinghe, Mohan

2013-01-01

Electrohydrodynamic (EHD) processing has attracted substantial interest in the technological and pharmaceutical sectors in recent years. Given the complexity of the process, exploring new ideas for EHD electrospraying and electrospinning delivery is a challenge. In this article, the design, construction and testing of a portable handheld EHD multi-needle device are described to produce multifunctional particles and fibers. Solid and encapsulated polymer particles and fibers were generated in order to study the performance of the device. The intrinsic properties of the feed solution/suspension and the processing conditions were adjusted to ensure robustness of the process and give uniform and reproducible products, with diameters ranging from the sub-micrometer scale to a few micrometers. These products have a broad range of applications in many advanced industrial sectors e.g. drug delivery systems, wound dressing patches, low calorie food products and cosmetics. Copyright © 2012 Elsevier B.V. All rights reserved.

Electrospray Collection of Airborne Contaminants, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In stark contrast to current stagnation-based methods for capturing airborne particulates and biological aerosols, our demonstrated, cost-effective electrospray...

Subcellular analysis by laser ablation electrospray ionization mass spectrometry

Science.gov (United States)

Vertes, Akos; Stolee, Jessica A; Shrestha, Bindesh

2014-12-02

In various embodiments, a method of laser ablation electrospray ionization mass spectrometry (LAESI-MS) may generally comprise micro-dissecting a cell comprising at least one of a cell wall and a cell membrane to expose at least one subcellular component therein, ablating the at least one subcellular component by an infrared laser pulse to form an ablation plume, intercepting the ablation plume by an electrospray plume to form ions, and detecting the ions by mass spectrometry.

Electrospray Propulsion Engineering Toolkit (ESPET), Phase II

Data.gov (United States)

National Aeronautics and Space Administration — To accelerate the development of scaled-up Electrospray Propulsion emitter array systems with practical thrust levels, Spectral Sciences, Inc. (SSI), in...

[Needling technique of Professor Li Yan-Fang].

Science.gov (United States)

Li, Li-Jun

2014-01-01

Experiences of needling techniques of Professor LI Ya- fang is introduced in this article. Gentle and superficial insertion is adopted by Professor LI in clinic. Emphases are put on the qi regulation function, needling sensation to the affected region and insertion with both hands, especially the function of the left hand as pressing hand. The gentle and superficial insertion should be done as the follows: hold the needle with the right hand, press gently along the running course of meridians with the left hand to promote qi circulation, hard pressing should be applied at acupoints to disperse the local qi and blood, insert the needle gently and quickly into the subcutaneous region with the right hand, and stop the insertion when patient has the needling sensation. While the fast needling is characterized with shallow insertion and swift manipulation: the left hand of the manipulator should press first along the running course of the meridian, and fix the local skin, hold the needle with the right hand and insert the needle quickly into the acupoint. Withdrawal of the needle should be done immediately after the reinforcing and reducing manipulations. Professor LI is accomplished in qi regulation. It is held by him that regulating qi circulation is essence of acupuncture, letting the patient get the needling sensation is the most important task of needling. Lifting, thrusting and rotation manipulations should be applied to do reinforcing or reducing. The tissue around the tip of the needle should not be too contracted or too relaxed, and the resistance should not be too strong or too weak. The feeling of the insertion hand of the practitioner should not be too smooth or too hesitant. Needle should be inserted into the skin quickly at the moment of hard pressing by the left hand. And then, slow rotation and gentle lifting and thrusting can be applied to promote the needling sensation like electric current pass through and to reach the affected region along the

A novel prototype 3/5 laparoscopic needle driver: A validation study with conventional laparoscopic needle driver.

Science.gov (United States)

Ganpule, Arvind P; Deshmukh, Chaitanya S; Joshi, Tanmay

2018-01-01

The challenges in laparoscopic suturing include need to expertise to suture. Laparoscopic needle holder is a" key" instrument to accomplish this arduous task. The objective of this new invention was to develop a laparoscopic needle holder which would be adapted to avoid any wobble (with a shaft diameter same as a 5mm port), ensure accurate and dexterous suturing not just in adult patients but pediatric patients alike (with a short shaft diameter) and finally ensure seamless throw of knots with a narrow tip configuration. We did an initial evaluation to evaluate the validity of the prototype needle holder and its impact on laparoscopic suturing skills by experienced laparoscopic surgeons and novice laparoscopic Surgeons. Both the groups of surgeons performed two tasks. The first task was to grasp the needle and position it in an angle deemed ideal for suturing. The second task was to pass suture through two fixed points and make a single square knot. At the end of the tasks each participant was asked to complete a 5- point Likert's scale questionnaire (8 items; 4 items of handling and 4 items of suturing) rating each needle holder. In expert group, the mean time to complete task 1 was shorter with prototype 3/5 laparoscopic needle holder (11.8 sec Vs 20.8 sec). The mean time to complete task 2 was also shorter with prototype 3/5 laparoscopic needle holder (103.2 sec Vs 153.2 sec). In novice group, mean time to complete both the task was shorter with prototype 3/5 laparoscopic needle holder. The expert laparoscopic surgeons as well as novice laparoscopic surgeons performed laparoscopic suturing faster and with more ease while using the prototype 3/5 laparoscopic needle holder.

Comparative cyto-histological study of needle tip aspirates and entry sites after intravitreal injection using different needle types.

Directory of Open Access Journals (Sweden)

Lyubomyr Lytvynchuk

Full Text Available A comparison of the cellular content of needle tip aspirates and entry sites after transconjunctival intravitreal injection (IVI using different needle types was performed. White outbred rats and human cadaver eyes were used for IVI by hypodermic 27 gauge (G and 30G needles, and spinal anesthesia Pencan 27G needles. Aspiration of vitreous for quantitative morphological and cell cultivation analysis, as well as cyto-histological analysis of aspirates and entry sites were carried out. The most common cells in the aspirates from all needle types were conjunctival epithelial-, ciliary body non-pigmented epithelial- and sclerocyte-like cells and granular proteins. Crystallized vitreous specimens were present in each aspirate. The entry sites of hypodermic needles showed marked trauma in all wall layers of rat and human eyes accompanied by cellular destruction and hemorrhages. Pencan 27G needle caused less tissue trauma with partial reposition of sclerocytes. Transconjunctival IVIs with hypodermic 27G and 30G, and Pencan 27G needles result in trauma of all layers of the eyeball. The possible consequences of cellular content being cut and injected into the eye, as well as the entry site wound shape deserve future consideration and improvements.

Physical Properties Of Acupuncture Needles: Do Disposable Acupuncture Needles Break With Normal Use

Science.gov (United States)

2016-06-01

Orofacial Pain Graduate...JOURNAL PHYSICAL PROPERTIES OF ACUPUNCTURE NEEDLES: DO DISPOSABLE ACUPUNCTURE NEEDLES BREAK WITH NORMAL USE? James Kyle Vick DDS, Orofacial Pain ...MS CAPT, DC, USN Orofacial Pain Department Head Naval Postgraduate Dental School vi    TABLE OF CONTENTS GUIDELINE I. TITLE

Changing the needle for lumbar punctures

DEFF Research Database (Denmark)

Engedal, Thorbjørn Søndergaard; Ording, H.; Vilholm, O. J.

2015-01-01

Objective: Post-dural puncture headache (PDPH) is a common complication of diagnostic lumbar punctures. Both a non-cutting needle design and the use of smaller size needles have been shown to greatly reduce the risk of PDPH. Nevertheless, larger cutting needles are still widely used. This study d...

Fabrication of Polymeric Coatings with Controlled Microtopographies Using an Electrospraying Technique.

Directory of Open Access Journals (Sweden)

Qiongyu Guo

Full Text Available Surface topography of medical implants provides an important biophysical cue on guiding cellular functions at the cell-implant interface. However, few techniques are available to produce polymeric coatings with controlled microtopographies onto surgical implants, especially onto implant devices of small dimension and with complex structures such as drug-eluting stents. Therefore, the main objective of this study was to develop a new strategy to fabricate polymeric coatings using an electrospraying technique based on the uniqueness of this technique in that it can be used to produce a mist of charged droplets with a precise control of their shape and dimension. We hypothesized that this technique would allow facile manipulation of coating morphology by controlling the shape and dimension of electrosprayed droplets. More specifically, we employed the electrospraying technique to coat a layer of biodegradable polyurethane with tailored microtopographies onto commercial coronary stents. The topography of such stent coatings was modulated by controlling the ratio of round to stretched droplets or the ratio of round to crumped droplets under high electric field before deposition. The shape of electrosprayed droplets was governed by the stability of these charged droplets right after ejection or during their flight in the air. Using the electrospraying technique, we achieved conformal polymeric coatings with tailored microtopographies onto conductive surgical implants. The approach offers potential for controlling the surface topography of surgical implant devices to modulate their integration with surrounding tissues.

Analysis of the NovoTwist pen needle in comparison with conventional screw-thread needles.

Science.gov (United States)

Aye, Tandy

2011-11-01

Administration of insulin via a pen device may be advantageous over a vial and syringe system. Hofman and colleagues introduce a new insulin pen needle, the NovoTwist, to simplify injections to a small group of children and adolescents. Their overall preferences and evaluation of the handling of the needle are reported in the study. This new needle has the potential to ease administration of insulin via a pen device that may increase both the use of a pen device and adherence to insulin therapy. © 2011 Diabetes Technology Society.

Sensitivity of electrospray molecular dynamics simulations to long-range Coulomb interaction models.

Science.gov (United States)

Mehta, Neil A; Levin, Deborah A

2018-03-01

Molecular dynamics (MD) electrospray simulations of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF_{4}) ion liquid were performed with the goal of evaluating the influence of long-range Coulomb models on ion emission characteristics. The direct Coulomb (DC), shifted force Coulomb sum (SFCS), and particle-particle particle-mesh (PPPM) long-range Coulomb models were considered in this work. The DC method with a sufficiently large cutoff radius was found to be the most accurate approach for modeling electrosprays, but, it is computationally expensive. The Coulomb potential energy modeled by the DC method in combination with the radial electric fields were found to be necessary to generate the Taylor cone. The differences observed between the SFCS and the DC in terms of predicting the total ion emission suggest that the former should not be used in MD electrospray simulations. Furthermore, the common assumption of domain periodicity was observed to be detrimental to the accuracy of the capillary-based electrospray simulations.

Intra-operative navigation of a 3-dimensional needle localization system for precision of irreversible electroporation needles in locally advanced pancreatic cancer.

Science.gov (United States)

Bond, L; Schulz, B; VanMeter, T; Martin, R C G

2017-02-01

Irreversible electroporation (IRE) uses multiple needles and a series of electrical pulses to create pores in cell membranes and cause cell apoptosis. One of the demands of IRE is the precise needle spacing required. Two-dimensional intraoperative ultrasound (2-D iUS) is currently used to measure inter-needle distances but requires significant expertise. This study evaluates the potential of three-dimensional (3-D) image guidance for placing IRE needles and calculating needle spacing. A prospective clinical evaluation of a 3-D needle localization system (Explorer™) was evaluated in consecutive patients from April 2012 through June 2013 for unresectable pancreatic adenocarcinoma. 3-D reconstructions of patients' anatomy were generated from preoperative CT images, which were aligned to the intraoperative space. Thirty consecutive patients with locally advanced pancreatic cancer were treated with IRE. The needle localization system setup added an average of 6.5 min to each procedure. The 3-D needle localization system increased surgeon confidence and ultimately reduced needle placement time. IRE treatment efficacy is highly dependent on accurate needle spacing. The needle localization system evaluated in this study aims to mitigate these issues by providing the surgeon with additional visualization and data in 3-D. The Explorer™ system provides valuable guidance information and inter-needle distance calculations. Copyright © 2016 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Effect of Blinding With a New Pragmatic Placebo Needle

Science.gov (United States)

Liu, Baoyan; Xu, Huanfang; Ma, Rui; Mo, Qian; Yan, Shiyan; Liu, Zhishun

2014-01-01

Abstract Placebo control is a useful method for determining the efficacy of a therapy. In acupuncture researches, the preferred method for placebo control is acupuncture using a placebo needle that has a blunt tip and achieves no skin penetration. We performed a crossover study to validate the blinding effect of a new type of placebo needle. Sixty volunteers were randomized to receive acupuncture using 2 types of needles with different sequences: sequence AB, involving first the pragmatic placebo needle and then the real needle, and sequence BA, in a reverse order. Placebo acupuncture was performed by administering the placebo needle through an adhesive pad without skin penetration on the acupoints LI4, RN12, BL25, and BL36. Real acupuncture was performed by needling through the pad and penetrating the skin to 15 mm using a real needle on the same acupoints. The acupuncture was administered every other day with 3 sessions for 1 type of needle. The primary outcome was the perception of needle penetration. Besides degree of acupuncture pain, type, and degree of needle sensation, needle acceptability and factors influencing the subject blinding effect were assessed. Needle penetration was felt by 100%, 90% (54/60), 88.3% (53/60), and 95% (57/60) of volunteers receiving placebo acupuncture and 98.3% (59/60), 96.7% (58/60), 95% (57/60), and 95% (57/60) of volunteers receiving real acupuncture on LI4, RN12, BL25, and BL36, respectively. Differences of the volunteers’ perception of needle penetration between the placebo needle and real needle were not significant for the 4 acupoints (all P > 0.05). Volunteers experienced fewer distension sensations (P = 0.01), a lower degree of needle sensation (P = 0.007), and less pain (P = 0.006) during placebo acupuncture than during real acupuncture. The placebo needle was more easily accepted than the real needle (OR = 1.63, 95% CI, 1.01–2.64). The influences of age, sex, educational level, acupuncture

Design and Production of an Articulating Needle Guide for Ultrasound-Guided Needle Block Manufactured With a Three-Dimensional Printer: Technical Communication.

Science.gov (United States)

Bigeleisen, Paul E

2017-05-15

Needle guides may allow the practitioner to align the needle with the probe when ultrasound-guided nerve block is performed. The author's goal was to design and fabricate an inexpensive ($1.90), disposable, needle guide that could articulate over a range from 85 degrees to 0 degrees with a three-dimension printer. Three-dimensional representations of an L50, L25, and C 60 ultrasound probe (Sono Site, Bothell, WA) were created using a laser scanner. Computer-aided design software (Solid Works, Waltham, MA) was used to design a needle bracket and needle guide to attach to these probes. A three-dimensional printer was used to fabricate the needle bracket and guide with acrylonitrile polybutadiene polystyrene. An echogenic needle was held in plane with the needle guide. The author performed a supraclavicular block in a morbidly obese patient. The needle was easily visualized. Similar guides that are commercially available cost as much as $400. A knowledge of computer-aided design is necessary for this work.

Laser Generated Leaky Acoustic Waves for Needle Visualization.

Science.gov (United States)

Wu, Kai-Wen; Wang, Yi-An; Li, Pai-Chi

2018-04-01

Ultrasound (US)-guided needle operation is usually used to visualize both tissue and needle position such as tissue biopsy and localized drug delivery. However, the transducer-needle orientation is limited due to reflection of the acoustic waves. We proposed a leaky acoustic wave method to visualize the needle position and orientation. Laser pulses are emitted on top of the needle to generate acoustic waves; then, these acoustic waves propagate along the needle surface. Leaky wave signals are detected by the US array transducer. The needle position can be calculated by phase velocities of two different wave modes and their corresponding emission angles. In our experiments, a series of needles was inserted into a tissue mimicking phantom and porcine tissue to evaluate the accuracy of the proposed method. The results show that the detection depth is up to 51 mm and the insertion angle is up to 40° with needles of different diameters. It is demonstrated that the proposed approach outperforms the conventional B-mode US-guided needle operation in terms of the detection range while achieving similar accuracy. The proposed method reveals the potentials for further clinical applications.

Numerical Modelling of Mutual Effect among Nearby Needles in a Multi-Needle Configuration of an Atmospheric Air Dielectric Barrier Discharge

Directory of Open Access Journals (Sweden)

Xiaoxing Zhang

2012-05-01

Full Text Available A numerical study has been conducted to understand the mutual effect among nearby needles in a multi-needle electrode dielectric barrier discharge. In the present paper, a fluid-hydrodynamic model is adopted. In this model, the mutual effect among nearby needles in a multi-needle configuration of an atmospheric air dielectric barrier discharge are investigated using a fluid-hydrodynamic model including the continuity equations for electrons and positive and negative ions coupled with Poisson’s equation. The electric fields at the streamer head of the middle needle (MN and the side needles (SNs in a three-needle model decreased under the influence of the mutual effects of nearby needles compared with that in the single-needle model. In addition, from the same comparison, the average propagation velocities of the streamers from MN and SNs, the electron average energy profile of MN and SNs (including those in the streamer channel, at the streamer head, and in the unbridged gap, and the electron densities at the streamer head of the MN and SNs also decreased. The results obtained in the current paper agreed well with the experimental and simulation results in the literature.

The effects of needle deformation during lumbar puncture

Directory of Open Access Journals (Sweden)

Hasan Hüseyin Özdemir

2015-01-01

Full Text Available Objective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP. Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1% of the needles. Deflection between 0.1° and 5° occurred in 43 (37.3% of the needles and deflection ≥ 5.1° occurred in 34 patients (29.6%. Forty-seven (41.5% patients experienced post lumbar puncture headache (PLPH and 13 (11.5% patients experienced intracranial hypotension (IH. No statistically significant correlation between the degree of deflection and headache was found (P > 0.05. Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH.

The effects of needle deformation during lumbar puncture

Science.gov (United States)

Özdemir, Hasan Hüseyin; Demir, Caner F.; Varol, Sefer; Arslan, Demet; Yıldız, Mustafa; Akil, Eşref

2015-01-01

Objective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP). Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1%) of the needles. Deflection between 0.1° and 5° occurred in 43 (37.3%) of the needles and deflection ≥ 5.1° occurred in 34 patients (29.6%). Forty-seven (41.5%) patients experienced post lumbar puncture headache (PLPH) and 13 (11.5%) patients experienced intracranial hypotension (IH). No statistically significant correlation between the degree of deflection and headache was found (P > 0.05). Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH. PMID:25883480

Preparation of Porous Nanostructures Controlled by Electrospray

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Dung The; Kim, Kyo-Seon [Kangwon National University, Chuncheon (Korea, Republic of); Nah, In Wook [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

2015-10-15

Various solid structures were prepared by electrospray technique. In this process, liquid flows out from a capillary nozzle under a high electrical potential and is subjected to an electric field, which causes elongation of the meniscus to form a jet. In our study, by controlling the amount of polyvinyl pyrrolydone in precursor solution, the jet either disrupted into droplets for the formation of spherical particles or was stretched in the electric field for the formation of fibers. During the electrospray process, the ethanol solvent was evaporated and induced the solidification of precursors, forming solid particles. The evaporation of ethanol solvent also enhanced the mass transport of solutes from the inner core to the solid shell, which facilitated fabrication of porous and hollow structure. The network structures were also prepared by heating the collector.

Development of electrosprayed mucoadhesive chitosan microparticles

DEFF Research Database (Denmark)

Moreno, Jorge Alberto S.; Mendes, Ana C.; Stephansen, Karen

2018-01-01

The efficacy of chitosan (CS) to be used as drug delivery carrier has previously been reported. However, limited work has been pursued to produce stable and mucoadhesive CS electrosprayed particles for oral drug delivery, which is the aim of this study. Various CS types with different molecular...

Ultrasound probe and needle-guide calibration for robotic ultrasound scanning and needle targeting.

Science.gov (United States)

Kim, Chunwoo; Chang, Doyoung; Petrisor, Doru; Chirikjian, Gregory; Han, Misop; Stoianovici, Dan

2013-06-01

Image-to-robot registration is a typical step for robotic image-guided interventions. If the imaging device uses a portable imaging probe that is held by a robot, this registration is constant and has been commonly named probe calibration. The same applies to probes tracked by a position measurement device. We report a calibration method for 2-D ultrasound probes using robotic manipulation and a planar calibration rig. Moreover, a needle guide that is attached to the probe is also calibrated for ultrasound-guided needle targeting. The method is applied to a transrectal ultrasound (TRUS) probe for robot-assisted prostate biopsy. Validation experiments include TRUS-guided needle targeting accuracy tests. This paper outlines the entire process from the calibration to image-guided targeting. Freehand TRUS-guided prostate biopsy is the primary method of diagnosing prostate cancer, with over 1.2 million procedures performed annually in the U.S. alone. However, freehand biopsy is a highly challenging procedure with subjective quality control. As such, biopsy devices are emerging to assist the physician. Here, we present a method that uses robotic TRUS manipulation. A 2-D TRUS probe is supported by a 4-degree-of-freedom robot. The robot performs ultrasound scanning, enabling 3-D reconstructions. Based on the images, the robot orients a needle guide on target for biopsy. The biopsy is acquired manually through the guide. In vitro tests showed that the 3-D images were geometrically accurate, and an image-based needle targeting accuracy was 1.55 mm. These validate the probe calibration presented and the overall robotic system for needle targeting. Targeting accuracy is sufficient for targeting small, clinically significant prostatic cancer lesions, but actual in vivo targeting will include additional error components that will have to be determined.

A low-level needle counter

International Nuclear Information System (INIS)

Fujita, Y.; Taguchi, Y.; Imamura, M.; Inoue, T.; Tanaka, S.

1977-01-01

A small end-window type gas-flow counter which has a sharpened needle (anode) against the end-window plane (cathode) was developed for low-level counting of β particles to the amount of less than one count per hour in solid sources of relatively high specific activity. The advantage of the needle counter for low-level work is that being of a conical shape the active volume as against the window area is small. The background count rate of 0.0092+-0.0005 cpm was obtained for a 10 mm dia needle counter operating in GM mode and in anticoincidence with a well-type NaI(Tl) guard crystal with massive shields. The counter design and the counter characteristics are presented in detail. The needle counter is simple in design, low-cost and stable in long time operation. (author)

Processing and Characterization of Needled Carbon Composites

Science.gov (United States)

2015-12-01

needle is used to insert high strength yarns (i.e., threads) through the dry fabric or prepreg laminate , leaving a loose thread loop underneath [9-11...capability which uses commercially-available felting needles to insert z-fibers into composite laminates at different angles (±45/90°) relative to the... laminate plane. Previous work with needled glass/epoxy composites has shown a 270% improvement in Mode I interlaminar fracture toughness when needled

The research of knitting needle status monitoring setup

Science.gov (United States)

Liu, Lu; Liao, Xiao-qing; Zhu, Yong-kang; Yang, Wei; Zhang, Pei; Zhao, Yong-kai; Huang, Hui-jie

2013-09-01

In textile production, quality control and testing is the key to ensure the process and improve the efficiency. Defect of the knitting needles is the main factor affecting the quality of the appearance of textiles. Defect detection method based on machine vision and image processing technology is universal. This approach does not effectively identify the defect generated by damaged knitting needles and raise the alarm. We developed a knitting needle status monitoring setup using optical imaging, photoelectric detection and weak signal processing technology to achieve real-time monitoring of weaving needles' position. Depending on the shape of the knitting needle, we designed a kind of Glass Optical Fiber (GOF) light guides with a rectangular port used for transmission of the signal light. To be able to capture the signal of knitting needles accurately, we adopt a optical 4F system which has better imaging quality and simple structure and there is a rectangle image on the focal plane after the system. When a knitting needle passes through position of the rectangle image, the reflected light from needle surface will back to the GOF light guides along the same optical system. According to the intensity of signals, the computer control unit distinguish that the knitting needle is broken or curving. The experimental results show that this system can accurately detect the broken needles and the curving needles on the knitting machine in operating condition.

On-line probe for fast electrochemistry/electrospray mass spectrometry. Investigation of polycyclic aromatic hydrocarbons.

Science.gov (United States)

Xu, X; Lu, W; Cole, R B

1996-12-01

A newly invented probe accessory for fast electrochemistry/electrospray mass spectrometry (EC/ESMS) is presented and evaluated. The device features a low-volume, three-electrode electrochemical cell which has been designed with a minimum distance between the working electrode and the "Taylor cone" inherent to the electrospray process. This configuration limits the time between electrochemical generation of ions and mass spectrometric analysis to an absolute minimum. A fused-silica layer insulates the microcylinder working electrode from the sample solution until immediately prior to the electrospray region, postponing electrode processes until the last moment. The same fused-silica layer insulates the working electrode from the surrounding auxiliary electrode, a stainless steel capillary that also serves as the electrospray capillary. The performance and capabilities of the novel electrochemistry/electrospray mass spectrometry system have been evaluated using polycyclic aromatic hydrocarbons (PAHs) as test analytes. In the positive ion EC/ESMS mode, oxidized forms (one-electron removal) of PAHs are produced in high yield. The ability to analyze reaction products appearing subsequent to the initial oxidation is also demonstrated.

Needle thoracostomy in the treatment of a tension pneumothorax in trauma patients: what size needle?

Science.gov (United States)

Zengerink, Imme; Brink, Peter R; Laupland, Kevin B; Raber, Earl L; Zygun, Dave; Kortbeek, John B

2008-01-01

A tension pneumothorax requires immediate decompression using a needle thoracostomy. According to advanced trauma life support guidelines this procedure is performed in the second intercostal space (ICS) in the midclavicular line (MCL), using a 4.5-cm (2-inch) catheter (5-cm needle). Previous studies have shown a failure rate of up to 40% using this technique. Case reports have suggested that this high failure rate could be because of insufficient length of the needle. To analyze the average chest wall thickness (CWT) at the second ICS in the MCL in a trauma population and to evaluate the length of the needle used in needle thoracostomy for emergency decompression of tension pneumothoraces. Retrospective review of major trauma admissions (Injury Severity Score >12) at the Foothills Medical Centre in Calgary, Canada, who underwent a computed tomography chest scan admitted in the period from October 2001 until March 2004. Subgroup analysis on men and women, /=40 years of age was defined a priori. CWT was measured to the nearest 0.01 cm at the second ICS in the MCL. The mean CWT in the 604 male patients and 170 female patients studied averaged 3.50 cm at the left second ICS MCL and 3.51 cm on the right. The mean CWT was significantly higher for women than men (p 4.5 cm and 24.1% to 35.4% of the women studied. A catheter length of 4.5 cm may not penetrate the chest wall of a substantial amount (9.9%-35.4%) of the population, depending on age and gender. This study demonstrates the need for a variable needle length for relief of a tension pneumothorax in certain population groups to improve effectiveness of needle thoracostomy.

Plume collimation for laser ablation electrospray ionization mass spectrometry

Science.gov (United States)

Vertes, Akos; Stolee, Jessica A.

2014-09-09

In various embodiments, a device may generally comprise a capillary having a first end and a second end; a laser to emit energy at a sample in the capillary to ablate the sample and generate an ablation plume in the capillary; an electrospray apparatus to generate an electrospray plume to intercept the ablation plume to produce ions; and a mass spectrometer having an ion transfer inlet to capture the ions. The ablation plume may comprise a collimated ablation plume. The device may comprise a flow cytometer. Methods of making and using the same are also described.

Liposomes self-assembled from electrosprayed composite microparticles

International Nuclear Information System (INIS)

Yu Dengguang; Yang Junhe; Wang Xia; Tian Feng

2012-01-01

Composite microparticles, consisting of polyvinylpyrrolidone (PVP), naproxen (NAP) and lecithin (PC), have been successfully prepared using an electrospraying process and exploited as templates to manipulate molecular self-assembly for the synthesis of liposomes in situ. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) observations demonstrate that the microparticles have an average diameter of 960 ± 140 nm and a homogeneous structure. X-ray diffraction (XRD) patterns, differential scanning calorimetry (DSC) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) results verify that the building blocks NAP and PC are scattered in the polymer matrix in a molecular way owing to the very fast drying of the electrospraying process and the favorable secondary interactions among the components. FESEM, scanning probe microscope (SPM) and TEM observations demonstrate that the liposomes can be achieved through molecular self-assembly in situ when the microparticles contact water thanks to ‘like prefers like’ and by means of the confinement effect of the microparticles. The liposomes have an encapsulation rate of 91.3%, and 80.7% of the drug in the liposomes can be freed into the dissolution medium in a sustained way and by a diffusion mechanism over a period of 24 h. The developed strategy not only provides a new, facile, and effective method to assemble and organize molecules of multiple components into liposomes with electrosprayed microparticles as templates, but also opens a new avenue for nanofabrication in a step-by-step and controllable way. (paper)

The production of ultra-thin layers of ion-exchange resin and metallic silver by electrospraying

International Nuclear Information System (INIS)

Wyllie, H.A.

1988-10-01

Highly efficient radioactive sources for use in radioisotope metrology have been prepared on ultra-thin layers of electrosprayed ion-exchange resin. The efficiency of these sources can be reduced for the purpose of radioactivity standardisation by coating them with conducting silver layers which are also produced by electrospraying. A description is given of improvements to the electrospraying methods, together with details of the rotating, oscillating source-mount turntable

Experiences with a new breast localisation needle

International Nuclear Information System (INIS)

Hergan, K.; Amann, T.; Doringer, W.; Hollenstein, P.

1990-01-01

In view of the increasing number of biopsies of non-palpable lesions of the female breast we found an ideal localisation system in the Hawkins breast localisation needle. Localisation was successful without technical problems in 31 out of 34 patients. The special advantages of the needle are its stability in position and excellent manoeverability due to the construction of the needle. The very simple handling of the needle is an advantage not only for the radiologist but also for the surgeon. (orig.) [de

Poly(amidoamine-Cholesterol Conjugate Nanoparticles Obtained by Electrospraying as Novel Tamoxifen Delivery System

Directory of Open Access Journals (Sweden)

R. Cavalli

2011-01-01

Full Text Available A new poly(amidoamine-cholesterol (PAA-cholesterol conjugate was synthesized, characterized and used to produce nanoparticles by the electrospraying technique. The electrospraying is a method of liquid atomization that consists in the dispersion of a solution into small charged droplets by an electric field. Tuning the electrospraying process parameters spherical PAA-chol nanoparticles formed. The PAA-cholesterol nanoparticles showed sizes lower than 500 nm and spherical shape. The drug incorporation capacity was investigated using tamoxifen, a lipophilic anticancer drug, as model drug. The incorporation of the tamoxifen did not affect the shape and sizes of nanoparticles showing a drug loading of 40%. Tamoxifen-loaded nanoparticles exhibited a higher dose-dependent cytotoxicity than free tamoxifen, while blank nanoparticles did not show any cytotoxic effect at the same concentrations. The electrospray technique might be proposed to produce tamoxifen-loaded PAA-chol nanoparticle in powder form without any excipient in a single step.

Novel electrosprayed nanospherules for enhanced aqueous solubility and oral bioavailability of poorly water-soluble fenofibrate.

Science.gov (United States)

Yousaf, Abid Mehmood; Mustapha, Omer; Kim, Dong Wuk; Kim, Dong Shik; Kim, Kyeong Soo; Jin, Sung Giu; Yong, Chul Soon; Youn, Yu Seok; Oh, Yu-Kyoung; Kim, Jong Oh; Choi, Han-Gon

2016-01-01

The purpose of the present research was to develop a novel electrosprayed nanospherule providing the most optimized aqueous solubility and oral bioavailability for poorly water-soluble fenofibrate. Numerous fenofibrate-loaded electrosprayed nanospherules were prepared with polyvinylpyrrolidone (PVP) and Labrafil(®) M 2125 as carriers using the electrospray technique, and the effect of the carriers on drug solubility and solvation was assessed. The solid state characterization of an optimized formulation was conducted by scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopic analyses. Oral bioavailability in rats was also evaluated for the formulation of an optimized nanospherule in comparison with free drug and a conventional fenofibrate-loaded solid dispersion. All of the electrosprayed nanospherule formulations had remarkably enhanced aqueous solubility and dissolution compared with free drug. Moreover, Labrafil M 2125, a surfactant, had a positive influence on the solubility and dissolution of the drug in the electrosprayed nanospherule. Increases were observed as the PVP/drug ratio increased to 4:1, but higher ratios gave no significant increases. In particular, an electrosprayed nanospherule composed of fenofibrate, PVP, and Labrafil M 2125 at the weight ratio of 1:4:0.5 resulted in a particle size of water-soluble fenofibrate.

21 CFR 868.5150 - Anesthesia conduction needle.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient to...

Freehand biopsy guided by electromagnetic needle tracking

DEFF Research Database (Denmark)

Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann

2011-01-01

To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.......To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....

[Professor WU Zhongchao's experience of penetration needling].

Science.gov (United States)

Zhang, Ning; Wang, Bing; Zhou, Yu

2016-08-12

Professor WU Zhongchao has unique application of penetration needling in clinical treatment. Professor WU applies penetration needling along meridians, and the methods of penetration needling include self-meridian penetration, exterior-interior meridian penetration, identical-name meridian penetration, different meridian penetration. The meridian differentiation is performed according to different TCM syndromes, locations and natures of diseases and acupoint nature, so as to make a comprehensive assessment. The qi movement during acupuncture is focused. In addition, attention is paid on anatomy and long-needle penetration; the sequence and direction of acupuncture is essential, and the reinforcing and reducing methods have great originality, presented with holding, waiting, pressing and vibrating. Based on classical acupoint, the acupoint of penetration needling is flexible, forming unique combination of acupoints.

Spraying mode effect on droplet formation and ion chemistry in electrosprays.

Science.gov (United States)

Nemes, Peter; Marginean, Ioan; Vertes, Akos

2007-04-15

Depending on the spraying conditions and fluid properties, a variety of electrospray regimes exists. Here we explore the changes in ion production that accompany the transitions among the three axial spraying modes, the burst mode, the pulsating Taylor cone mode, and the cone-jet mode. Spray current oscillation and phase Doppler anemometry measurements, fast imaging of the electrified meniscus, and mass spectrometry are utilized to study the formation, size, velocity, and chemical composition of droplets produced in the three modes. High-speed images indicate that the primary droplets are produced by varicose waves and lateral kink instabilities on the liquid jet emerging from the Taylor cone, whereas secondary droplets are formed by fission. Dramatic changes in the droplet size distributions result from the various production and breakup mechanisms observed at different emitter voltages and liquid flow rates. We demonstrate that droplet fission can be facilitated by space charge effects along the liquid jet and in the plume. Compared to the other two regimes, a significantly enhanced signal-to-noise ratio, a lower degree of analyte oxidation, and milder fragmentation are observed for the cone-jet mode.

EUS needle identification comparison and evaluation (NICE) study (with videos)

Science.gov (United States)

Tang, Shou-jiang; Vilmann, Andreas S.; Saftoiu, Adrian; Wang, Wanmei; Streba, Costin; Fink, Peter P.; Griswold, Michael; Wu, Ruonan; Dietrich, Christoph F.; Jenssen, Christian; Hocke, Michael; Kantowski, Marcus; Pohl, Jürgen; Fockens, Paul; Annema, Jouke T.; van der Heijden, Erik H.F.M.; Havre, Roald Flesland; Pham, Khanh Do-Cong; Kunda, Rastislav; Deprez, Pierre H.; Mariana, Jinga; Vazquez-Sequeiros, Enrique; Larghi, Alberto; Buscarini, Elisabetta; Fusaroli, Pietro; Lahav, Maor; Puri, Rajesh; Garg, Pramod Kumar; Sharma, Malay; Maluf-Filho, Fauze; Sahai, Anand; Brugge, William R.; Lee, Linda S.; Aslanian, Harry R.; Wang, Andrew Y.; Shami, Vanessa M.; Markowitz, Arnold; Siddiqui, Ali A.; Mishra, Girish; Scheiman, James M.; Isenberg, Gerard; Siddiqui, Uzma D.; Shah, Raj J.; Buxbaum, James; Watson, Rabindra R.; Willingham, Field F.; Bhutani, Manoop S.; Levy, Michael J.; Harris, Cynthia; Wallace, Michael B.; Nolsøe, Christian Pállson; Lorentzen, Torben; Bang, Niels; Sørensen, Sten Mellerup; Gilja, Odd Helge; D’Onofrio, Mirko; Piscaglia, Fabio; Gritzmann, Norbert; Radzina, Maija; Sparchez, Zeno Adrian; Sidhu, Paul S.; Freeman, Simon; McCowan, Timothy C.; de Araujo, Cyrillo Rodrigues; Patel, Akash; del Ali, Mohammad A; Campbell, Garth; Chen, Edward; Vilmann, Peter

2017-01-01

Background and Aims Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) or biopsy is widely practiced. Optimal sonographic visualization of the needle is critical for image guided interventions. There are several commercially available needles but no bench-top testing and direct comparison of these needles to reveal their inherent echogenicity. The aims are to provide bench-top data that can be used to guide clinical applications and to promote future device research and development. Methods Descriptive bench-top testing and comparison. Bench-top testing of 8 commonly used EUS-FNA needles (all of 22 gauge in size): SonoTip Pro Control (Medi-Globe); Expect Slimline (Boston Scientific); EchoTip, EchoTip Ultra, EchoTip ProCore High Definition, (Cook Medical); ClearView (Conmed); EZ Shot2 (Olympus); BNX (Beacon Endoscopic); and 2 new prototype needles that are coated by echogenic polymers by Medi-Globe. Blinded evaluation of standardized and unedited videos by 43 EUS endoscopists and 17 radiologists specialized in gastrointestinal ultrasound examination that is unfamiliar with EUS needle devices. Results There was no significant difference in the ratings and rankings of these needles between endosonographers and radiologists. Overall, one prototype needle was rated as the best, ranking 10% to 40% higher than all other needles (p<0.01). Among the commercially available needles, the EchoTip Ultra needle and the ClearView needle were top choices. The EZ Shot 2 needle was ranked statistically lower than other needles (30%–75% worse, p<0.001). Conclusions All FNA needles have their inherent and different echogenicity, and these differences are similarly recognized by EUS endoscopists and radiologists. Needles with polymeric coating from the entire shaft to the needle tip may offer better echogenicity. PMID:26873530

Effect of bidirectional rotation of an acupuncture needle at LI10 on acupuncture needle sensation and experimentally-induced contact heat pain in healthy human volunteers.

Science.gov (United States)

Benham, Alex; Johnson, Mark I

2014-06-01

There is insufficient evidence of a relationship between acupuncture needle sensations (de qi) and hypoalgesia. The aim of this study was to investigate the effects of bidirectional needle rotation at LI10 on acupuncture needle sensations and heat pain thresholds. Twenty-two healthy participants received one acupuncture needle at LI10 with bidirectional rotation of the needle in one experimental session and one acupuncture needle at LI10 with mock rotation in a separate session, in a randomised order. Measurements of heat pain thresholds were taken before needle insertion, during needle retention and 15 min after needle removal. At each measurement time point, participants rated needle sensations using the Massachusetts Acupuncture Sensation Scale (MASS) and a visual analogue scale (VAS) of overall intensity of needle sensation. Bidirectional needle rotation produced significantly higher scores for VAS, MASStotal, MASSpain and MASSsensation compared with mock rotation (all psensation and change in pain threshold after needling was only found when data from mock and rotation interventions were combined. Needle rotation increases the magnitude of hypoalgesia. There is tentative evidence that needle sensation may be associated with the amount of change in pain threshold. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Needle counter

International Nuclear Information System (INIS)

Fujita, Yuzo

1977-01-01

Needle counter had been devised by Geiger about 60 years ago before the present GM counter appeared. It is suitable for the detection of weak radiation because it is limited in effective volume, if the background due to mainly cosmic ray is proportional to the effective volume of the counter. Recently the very low β detector having a needle counter as the main detector has been developed. It showed highly excellent performance in the measurements of small area samples, about ten times sensitive as compared with other detectors. The counter is installed in the very low radiation measuring well at Nokogiriyama, Chiba Prefecture, using a NaI scintillator as its guard counter. D. H. Wilkinson first treated a gas amplification counter theoretically and quantitatively. The authors have obtained good results in the comparison with the experiments of the counter using a generalized form of Wilkinson theory. The findings obtained through this study seem to be applicable to the electrode arrangement which is important for the counter design. It was found that the excellent rise time of induced pulses in a gas amplification counter was achieved in larger amplification factor and smaller convolution effect. In the detection of charged particles with small obstructing capability such as γ ray, faster rise time and higher pulses can be obtained with needle counters than wire counters. (Wakatsuki, Y.)

Observations of needle-tissue interactions

NARCIS (Netherlands)

Misra, Sarthak; Reed, Kyle B.; Ramesh, K.T.; Okamura, Allison M.

2009-01-01

Needles with asymmetric bevel tips naturally bend when they are inserted into soft tissue. In this study, we present an analytical model for the loads developed at the bevel tip during needle-tissue interaction. The model calculates the loads based on the geometry of the bevel edge and gel material

Radio-frequency ablation in patients with malignant hepatic tumor and experimental model: comparison of expandable needle and water-cooled needle

Energy Technology Data Exchange (ETDEWEB)

Moon, Yong Ju; Jeong, Yong Yeon; Kim, Jeong; Yim, Nam yeol; Kang, Heoung Keun [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of); Kim, Eun Ha; Yoon, Kwon Ha [School of Medicine, Wonkwang Univ., Iksan (Korea, Republic of); Ko, Seog Wan [School of Medicine, Chonbuk National Univ., Jeonju (Korea, Republic of)

2004-12-01

The purpose of this study was to compare the shape and volume of the radio-frequency induced lesions produced by two commercially available radio-frequency ablation (RFA) systems, the expandable and cooled-tip needles, in clinical patients and an experimental model. A twelve-array anchor expandable needle electrode and a single cooled-tip needle electrode were used to treat hepatic tumors with a single session in 23 patients (20 hepatocellular carcinomas and 3 hepatic metastases) and fourteen patients (10 hepatocellular carcinomas and 4 hepatic metastases), respectively. Twenty RFA induced lesions were created with each system in 10 explanted bovine livers. The shape of the RFA induced lesions were divided into oval lesions along or perpendicular to the axis of the electrode and spherical lesions, and we then calculated the volumes of the RFA induced lesions. Fourteen (61%) lesions of the 23 patients treated with the expandable system were oval perpendicular to the axis of the electrode and nine (39%) of the lesions were spherical. All the lesions (100%) of the 14 patients treated with the cooled-tip needle were ovaI along the axis of the electrode. In the ex vivo bovine livers, the shape of the all RFA induced lesions was oval perpendicular to the axis of the electrode for the expandable needle, and oval along the axis of the electrode for the cooled-tip needle. The mean diameter and volume of the RFA induced lesions in the patients were 3.35{+-}0.56 cm and 19.9{+-}6.53 cm{sup 3}, respectively, for the expandable needle and 3.58{+-}0.78 cm and 23.19{+-}5.27 cm{sup 3}, respectively, for the cooled-tip needle. In the ex vivo model, the mean diameter and volume of RFA induced lesions were 3.41{+-}0.59 cm and 26.59{+-}8.02 cm{sup 3}, respectively, for the expandable needle, and 4.04{+-}0.65 cm and 33.82{+-}6.16 cm{sup 3}, respectively, for the cooled-tip needle (p <0.05). These results indicate that the shape of RFA induced lesions with the expandable needle were oval

Current status of core needle biopsy of the thyroid

Energy Technology Data Exchange (ETDEWEB)

Baek, Jung Hwan [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2017-04-15

Thyroid nodules are a common clinical problem. Fine-needle aspiration (FNA) and large-needle biopsy have been used to diagnose thyroid nodules. Before the 1980s, large-needle biopsy was the standard procedure for the thyroid, but FNA became the standard diagnostic tool in the 1980s because it is a safe procedure that leads to accurate diagnoses. With advances in core needle biopsy (CNB) devices (i.e., spring-activated core needles) and development of high-resolution ultrasound, it has become possible to make accurate diagnoses while minimizing complications. Although 18- to 21-gauge core needles can be used to biopsy thyroid nodules, 18-gauge needles are most commonly used in Korea. The relationships among the size of the needle, the number of core specimens, and diagnostic accuracy have not yet been conclusively established, but the general tendency is that thinner needles cause less damage to the normal thyroid, but allow a smaller amount of thyroid tissue to be biopsied to be obtained. These relationships may be validated in the future.

Crystal engineering of lactose using electrospray technology: carrier for pulmonary drug delivery.

Science.gov (United States)

Patil, Sharvil; Mahadik, Abhijeet; Nalawade, Pradeep; More, Priyesh

2017-12-01

Dry powder inhalers (DPIs) consisting of a powder mixture containing coarse carrier particles (generally lactose) and micronized drug particles are used for lung drug delivery. The effective drug delivery to the lungs depends on size and shape of carrier particles. Thus, various methods have been proposed for engineering lactose particles to enhance drug delivery to lungs. The objective of current work was to assess suitability of electrospray technology toward crystal engineering of lactose. Further, utility of the prepared lactose particles as a carrier in DPI was evaluated. Saturated lactose solutions were electrosprayed to obtain electrosprayed lactose (EL) particles. The polymorphic form of EL was determined using Fourier transform infrared spectroscopy, powder X-ray diffractometry, and differential scanning calorimetry. In addition, morphological, surface textural, and flow properties of EL were determined using scanning electron microscopy and Carr's index, respectively. The aerosolization properties of EL were determined using twin-stage impinger and compared with commercial lactose particles [Respitose ® (SV003, Goch, Germany)] used in DPI formulations. EL was found to contain both isomers (α and β) of lactose having flow properties comparable to Respitose ® (SV003). In addition, the aerosolization properties of EL were found to be significantly improved when compared to Respitose ® (SV003) which could be attributed to morphological (high elongation ratio) and surface characteristic (smooth surface) alterations induced by electrospray technology. Electrospray technology can serve as an alternative technique for continuous manufacturing of engineered lactose particles which can be used as a carrier in DPI formulations.

Pharmaceutical microparticle engineering with electrospraying

DEFF Research Database (Denmark)

Bohr, Adam; Wan, Feng; Kristensen, Jakob

2015-01-01

Microparticles of Celecoxib, dispersed in a matrix of poly(lactic-co-glycolic acid) (PLGA), were prepared by electrospraying using different solvent mixtures to investigate the influence upon particle formation and the resulting particle characteristics. Mixtures consisting of a good solvent, ace...... demonstrated by the increasingly higher drug release rates. The results demonstrate the importance of solvent composition in particle preparation and indicate potential for exploiting this dependence to improve pharmaceutical particle design and performance....

Deposition of Ge{sub 23}Sb{sub 7}S{sub 70} chalcogenide glass films by electrospray

Energy Technology Data Exchange (ETDEWEB)

Novak, Spencer, E-mail: spencen@g.clemson.edu [Department of Materials Science and Engineering, COMSET, Clemson University, Clemson, SC (United States); College of Optics and Photonics, CREOL, University of Central FL (United States); Johnston, Danvers E.; Li, Cheng; Deng, Weiwei [Department of Mechanical and Aerospace Engineering, University of Central FL (United States); Richardson, Kathleen [Department of Materials Science and Engineering, COMSET, Clemson University, Clemson, SC (United States); College of Optics and Photonics, CREOL, University of Central FL (United States)

2015-08-03

Solution-based chalcogenide glass films, traditionally deposited by spin-coating, are attractive for their potential use in chip-based devices operating in the mid-infrared and for ease of nanostructure incorporation. To overcome limitations of spin-coating such as excessive material waste and difficulty for scale-up, this paper introduces electrospray as a film deposition technique for solution-based chalcogenide glasses. Electrospray is shown to produce Ge{sub 23}Sb{sub 7}S{sub 70} films with similar surface quality and optical properties as films deposited by spin-coating. The advantages of electrospray deposition for nanoparticle dispersion, scalable and continuous manufacturing with little material waste, and comparable film quality to spin-coating make electrospray a promising deposition method for practical applications of chalcogenide glass films. - Highlights: • Electrospray film deposition processing of Ge{sub 23}Sb{sub 7}S{sub 70} films was developed. • Traditional spin-coated films were also fabricated in parallel. • Optical properties and surface quality found to be similar between two approaches.

Pine needle abortion biomarker detected in bovine fetal fluids

Science.gov (United States)

Pine needle abortion is a naturally occurring condition in free-range cattle caused by the consumption of pine needles from select species of cypress, juniper, pine, and spruce trees. Confirmatory diagnosis of pine needle abortion has previously relied on a combined case history of pine needle cons...

Solid state transformations in consequence of electrospraying--a novel polymorphic form of piroxicam.

Science.gov (United States)

Nyström, Maija; Roine, Jorma; Murtomaa, Matti; Mohan Sankaran, R; Santos, Hélder A; Salonen, Jarno

2015-01-01

The aim of the research was to verify that electrospraying of piroxicam yielded a new polymorphic form of this drug. In the experiments, piroxicam was dissolved in chloroform and the solution was atomised electrostatically. Subsequently, the charged droplets were neutralised and dried. The solid drug particles were collected and analysed by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, high performance liquid chromatography, and infrared and Raman spectroscopy. The X-ray diffractogram measured for the electrosprayed piroxicam particles did not match with any of the known piroxicam crystal structures (Cambridge Crystallographic Data Centre). The variable temperature X-ray diffraction showed that the structure recrystallised completely into piroxicam polymorphic formI during heating. No degradation products or solvate removal was detected by high performance liquid chromatography and thermal analysis. The infrared and Raman spectra of the electrosprayed piroxicam were compared to those of formI, and some notable differences in the peak positions, shapes and intensities were detected. The results indicate that electrospraying leads to piroxicam crystallisation in a currently unknown polymorphic form. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of solvent dyes in refined petroleum products by electrospray ionization mass spectrometry

Science.gov (United States)

Rostad, C.E.

2010-01-01

Solvent dyes are used to color refined petroleum products to enable differentiation between gasoline, diesel, and jet fuels. Analysis for these dyes in the hydrocarbon product is difficult due to their very low concentrations in such a complex matrix. Flow injection analysis/electrospray ionization/mass spectrometry in both negative and positive mode was used to optimize ionization of ten typical solvent dyes. Samples of hydrocarbon product were analyzed under similar conditions. Positive electrospray ionization produced very complex spectra, which were not suitably specific for targeting only the dyes. Negative electrospray ionization produced simple spectra because aliphatic and aromatic moieties were not ionized. This enabled screening for a target dye in samples of hydrocarbon product from a spill.

STUDY & ANALYSIS OF MICRO NEEDLE MATERIAL BY ANSYS

OpenAIRE

Santosh Kumar Singh*, Prabhat Sinha, N.N. Singh, Nagendra Kumar

2017-01-01

In this research the concept of design and analysis, silicon and stainless steel based on hollow micro-needles for transdermal drug delivery(TDD) have been evaluated by Using ANSYS & computational fluid dynamic (CFD), structural. Micro fluidic analysis has performed to ensure the micro-needles design suitability for Drug delivery. The effect of axial and transverse load on single and micro-needle array has investigated with the mechanical properties of micro-needle. The analysis predicte...

AC electrical breakdown phenomena of epoxy/layered silicate nanocomposite in needle-plate electrodes.

Science.gov (United States)

Park, Jae-Jun; Lee, Jae-Young

2013-05-01

Epoxy/layered silicate nanocomposite for the insulation of heavy electric equipments were prepared by dispersing 1 wt% of a layered silicate into an epoxy matrix with a homogenizing mixer and then AC electrical treeing and breakdown tests were carried out. Wide-angle X-ray diffraction (WAXD) analysis and transmission electron microscopy (TEM) observation showed that nano-sized monolayers were exfoliated from a multilayered silicate in the epoxy matrix. When the nano-sized silicate layers were incorporated into the epoxy matrix, the breakdown rate in needle-plate electrode geometry was 10.6 times lowered than that of the neat epoxy resin under the applied electrical field of 520.9 kV/mm at 30 degrees C, and electrical tree propagated with much more branches in the epoxy/layered silicate nanocomposite. These results showed that well-dispersed nano-sized silicate layers retarded the electrical tree growth rate. The effects of applied voltage and ambient temperature on the tree initiation, growth, and breakdown rate were also studied, and it was found that the breakdown rate was largely increased, as the applied voltage and ambient temperature increased.

Synthesis of yttria powders by electrospray pyrolysis

International Nuclear Information System (INIS)

Rulison, A.J.; Flagan, R.C.

1994-01-01

Electrospray atomization of high-concentration (∼400 g/L) chemical precursor solutions was applied to the synthesis of yttria powders. Conditions were found which led to high-quality powders, composed of dense, spheroidal, submicrometer, and nanocrystalline oxide particles. The precursor solutions were hydrated yttrium nitrates dissolved in n-propyl alcohol at concentrations ranging from 44.1 to 455 g/L. Electrospray atomization produced submicrometer precursor droplets which were dispersed in air and carried through an electric furnace for thermal decomposition at 500 C for several seconds residence time. X-ray powder diffraction patterns indicated the expected cubic phase. Transmission electron micrographs showed that the particle structure varied with solution composition, ranging from hollow, inflated spheres for 6-hydrated nitrates to dense spheroids for 5-hydrated nitrates. The use of 6-hydrated nitrates in the solutions appeared to form particle surfaces which were impermeable to alcohol vapor evolved during thermal decomposition, leading to hollow, inflated spheres

The efficacy of an ultrasound-guided core needle biopsy with an 18G cutting needle for the diagnosis of pancreatic diseases

International Nuclear Information System (INIS)

Jung, Sung Hwa; Park, Won Kyu; Chang, Jay Chun; Kim, Jae Woon; Cho, Jae Ho; Jang, Han Won; Lee, Jae Kyo; Choi, Joon Hyuk

2008-01-01

The objective of this study is to evaluate the efficacy and safety of an ultrasound-guided core needle biopsy with an 18G cutting needle in patients suspected of having a pancreatic disease by analyzing the diagnostic performance and complication rate. The study population comprised 35 consecutive patients who underwent an ultrasound-guided core needle biopsy using a high-speed biopsy gun accompanied with an 18G cutting-type needle between May of 2001 and October of 2005. The diagnostic performance (i.e., the acquisition rate and diagnostic accuracy) and complications associated with core needle biopsies were evaluated for its efficacy and safety. Thirty-six sessions of ultrasound-guided core needle biopsies were performed in 35 consecutive patients. All patients, except two (serous cystadenoma and autoimmune pancreatitis) were diagnosed with various subtypes of pancreatic cancer. The acquisition rate and diagnostic accuracy were 97% (35/36) and 94% (34/36), respectively. A complication occurred only in one patient (3%), which further proved to be a delayed complication (i.e., needle tract implantation). According to our findings, the ultrasound-guided core needle biopsy is a viable and safe method for the diagnosis of pancreatic diseases. Moreover, it enables the diagnosis of the pancreatic cancer subtype

NPIP: A skew line needle configuration optimization system for HDR brachytherapy

International Nuclear Information System (INIS)

Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtürk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean

2012-01-01

Purpose: In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and other healthy structures, and avoid needle collisions inside the body. Methods: NPIP consisted of three major components: a method for generating a set of candidate needles, a needle selection component that chose a candidate needle subset to be inserted, and a dose planner for verifying that the final needle configuration could meet dose objectives. NPIP was used to compute needle configurations for prostate cancer data sets from patients previously treated at our clinic. NPIP took two user-parameters: a number of candidate needles, and needle coverage radius, δ. The candidate needle set consisted of 5000 needles, and a range of δ values was used to compute different needle configurations for each patient. Dose plans were computed for each needle configuration. The number of needles generated and dosimetry were analyzed and compared to the physician implant. Results: NPIP computed at least one needle configuration for every patient that met dose objectives, avoided healthy structures and needle collisions, and used as many or fewer needles than standard practice. These needle configurations corresponded to a narrow range of δ values, which could be used as default values if this system is used in practice. The average end-to-end runtime for this implementation of NPIP was 286 s, but there was a wide variation from case to case. Conclusions: The authors have shown that NPIP can automatically generate skew line needle configurations with the aforementioned properties, and that given the correct input parameters, NPIP can generate needle configurations which meet dose objectives and use as many or fewer

Medically relevant ElectroNeedle technology development.

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Carrie Frances; Thomas, Michael Loren; McClain, Jaime L.; Harper, Jason C.; Achyuthan, Komandoor E.; Ten Eyck, Gregory A.

2008-11-01

ElectroNeedles technology was developed as part of an earlier Grand Challenge effort on Bio-Micro Fuel Cell project. During this earlier work, the fabrication of the ElectroNeedles was accomplished along with proof-of-concept work on several electrochemically active analytes such as glucose, quinone and ferricyanide. Additionally, earlier work demonstrated technology potential in the field of immunosensors by specifically detecting Troponin, a cardiac biomarker. The current work focused upon fabrication process reproducibility of the ElectroNeedles and then using the devices to sensitively detect p-cresol, a biomarker for kidney failure or nephrotoxicity. Valuable lessons were learned regarding fabrication assurance and quality. The detection of p-cresol was accomplished by electrochemistry as well as using fluorescence to benchmark ElectroNeedles performance. Results from these studies will serve as a guide for the future fabrication processes involving ElectroNeedles as well as provide the groundwork necessary to expand technology applications. One paper has been accepted for publication acknowledging LDRD funding (K. E. Achyuthan et al, Comb. Chem. & HTS, 2008). We are exploring the scope for a second paper describing the applications potential of this technology.

Migration of innumerable chronically retained acupuncture needles

Directory of Open Access Journals (Sweden)

Frances Lazarow, MD

2017-09-01

Full Text Available We present a case of a 50-year-old female with a 2-day history of back and abdominal pain who was discovered to have innumerable chronically retained acupuncture needles, which had migrated throughout her abdomen and pelvis. Although many of these needles were in precarious positions, including the epidural space, renal parenchyma, small bowel, and vasculature, there was no evidence for acute injury. We also briefly discuss evidence for the magnetic resonance imaging compatibility of acupuncture needles. Although a rare complication, given the high frequency of acupuncture therapy in the United States, physicians must be aware of the potential for retained and migrated needles.

Needle muscle biopsy and its application

Directory of Open Access Journals (Sweden)

Meng-long CHEN

2015-07-01

Full Text Available Needle muscle biopsy is a straightforward and reliable minimally-invasive technique. During the past century, the needle biopsy can provide adequate samples and the technique has gradually gained wider acceptance. Compared with open biopsy, needle biopsy is less traumatic, with low rate of complications, and is suitable for the identifications and evaluations of muscular dystrophy, inflammatory myopathies and systemic diseases involving muscles, specially for infants and young children. Domestic insiders should be encouraged to apply this technique. DOI: 10.3969/j.issn.1672-6731.2015.06.003 

Dehydrodimerization of pterostilbene during electrospray ionization mass spectrometry

KAUST Repository

Raji, Misjudeen; Amad, Maan H.; Emwas, Abdul-Hamid M.

2013-01-01

RATIONALE Pterostilbene is a member of the hydroxystilbene family of compounds commonly found in plants such as blueberry and grapes. During the analysis of this compound by electrospray ionization mass spectrometry (ESI-MS), an ion was observed

Linear inductive voltage adders (IVA) for advanced hydrodynamic radiography

International Nuclear Information System (INIS)

Mazarakis, M.G.; Boyes, J.D.; Johnson, D.L.

1998-01-01

The electron beam which drifts through the multiple cavities of conventional induction linacs (LIA) is replaced in an IVA by a cylindrical metal conductor which extends along the entire length of the device and effectuates the addition of the accelerator cavity voltages. In the approach to radiography, the linear inductive voltage adder drives a magnetically immersed electron diode with a millimeter diameter cathode electrode and a planar anode/bremsstrahlung converter. Both anode and cathode electrodes are immersed in a strong (15--50 T) solenoidal magnetic field. The electron beam cross section is approximately of the same size as the cathode needle and generates a similar size, very intense x-ray beam when it strikes the anode converter. An IVA driven diode can produce electron beams of equal size and energy as a LIA but with much higher currents (40--50 kA versus 4--5 kA), simpler hardware and thus lower cost. The authors present here first experimental validations of the technology utilizing HERMES 3 and SABRE IVA accelerators. The electron beam voltage and current were respectively of the order of 10 MV and 40 kA. X-ray doses of up to 1 kR at sign 1 m and spot sizes as small as 1.7 mm (at 200 R doses) were measured

Electrosprayed Heavy Ion and Nanodrop Beams for Surface Engineering and Electrical Propulsion

Science.gov (United States)

2014-09-10

Studies At the macroscale, the surface of a Taylor cone just before ion emission is an equipotential with a normal electric field strength found from...AFRL-OSR-VA-TR-2014-0246 Electrosprayed Heavy Ion and Nanodrop Beams for Surface Engineering M Gamero-Castano UNIVERSITY OF CALIFORNIA IRVINE Final...298 (Re . 8-98) v Prescribed by ANSI Std. Z39.18 1 Electrosprayed Heavy Ion and Nanodrop Beams for Surface Engineering and Electrical Propulsion

Investigation of environmental pollution with pine needles by NAA

Energy Technology Data Exchange (ETDEWEB)

Lee, Kil Yong; Yoon, Yoon Yeol; Yang, Myung Kwon; Shim, Sang Kwon; Seo, Bum Kyoung [Korea Inst. of Geosience and Mineral Resources, Environmental Geology Division, Daejeon (Korea); Chung, Yong Sam [Korea Atomic Energy Research Inst., HANARO Center, Daejeon (Japan)

2002-04-01

NAA was studied to precision analysis of metallic elements in pine needle. The pine needle was investigated whether it can be feasible or not as a bio-monitor. Only one year old needle was taken from three different regions of urban, suburban and rural area in four seasons. The needle sample was divided with two aliquots, and then one was cleaned and the other was not. Loss and contamination of analytes were cautiously minimized when the needle was sample and transferred from mountain to laboratory and prepared for NAA. Some elements such as As, Br, Ce, W, Zn have shown different characteristics with regions and seasons as well as surface cleaning. It is found that about twenty elements in pine needle could be simply analyzed by NAA and the pine needle could be suitable as a bio-monitor for the monitoring of environmental pollution in Korea. (author)

Laser diagnostics of an evaporating electrospray

Science.gov (United States)

Yi, Tongxun

2014-01-01

An electrospray atomizer generates monodisperse, dilute sprays when working in the cone-jet mode. Evolution of an electrospray with droplet diameter below 10 μm is studied with phase Doppler particle analyzer (PDPA) and the exciplex-PLIF technique. The evaporation rate constant is determined from droplet velocity and diameter measured with a PDPA and is found to sharply increase with the velocity slip and the coflow temperature. Fluorescence around 400 nm, usually referred to as TMPD fluorescence, is calibrated with a heated, laminar, coflow vapor jet diluted with nitrogen. The TMPD fluorescence yield nonlinearly increases with temperature up to 538 K and then declines. Single-shot images show that fluorescence around 400 nm is mainly generated from TMPD vapor and that from droplets can be neglected as a first analysis; however, fluorescence around 490 nm, usually referred to as exciplex fluorescence, is generated from both droplets and fuel vapor immediately around droplets. Exciplex fluorescence is correlated with PDPA measurements and TMPD fluorescence. Effects of temperature, fuel composition, overlap of fluorescent spectra, and chemical equilibrium for exciplex formation are discussed. Technical challenges for quantitative exciplex-PLIF measurements are highlighted.

PC-based control of a high-voltage injector

International Nuclear Information System (INIS)

Constantin, F.

1998-01-01

current control was realized by a stepping motor that rotates a variable resistor through an insulating stick. Two hundred motor steps per complete rotation assumes a very good resolution in driving the filament current between 0 Amps and maximum 40 Amps. The gas flow control is realized by a stepping motor that drives a needle valve. The flow gas can be varied in very small steps. The vacuum read-out is performed by two gauges, Penning and Pirani, providing a 0 to 10 V analog signal. The DC voltages are input to two ADC channels. The current and voltage source control is performed by ADC and DAC channels that drive/read the source output. The outside computer presents an user friendly interface by a Visual Basic program. It permits to vary all the mentioned quantities and reports periodically (at every two seconds) the output values. The user drives the program only with the mouse, having complete control all over the electric hardware inside the injector. A fast reset function is also provided in case of severe malfunction. (author)

The analysis of aqueous mixtures using liquid chromatography-electrospray mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Johnson, Steven [Iowa State Univ., Ames, IA (United States)

1999-02-12

The focus of this dissertation is the use of chromatographic methods coupled with electrospray mass spectrometry (ES-MS) for the determination of both organic and inorganic compounds in aqueous solutions. The combination of liquid chromatography (LC) methods and ES-MS offers one of the foremost methods for determining compounds in complex aqueous solutions. In this work, LC-ES-MS methods are devised using ion exclusion chromatography, reversed phase chromatography, and ion exchange chromatography, as well as capillary electrophoresis (CE). For an aqueous sample, these LC-ES-MS and CE-ES-MS techniques require no sample preparation or analyte derivatization, which makes it possible to observe a wide variety of analytes as they exist in solution. The majority of this work focuses on the use of LC-ES-MS for the determination of unknown products and intermediates formed during electrochemical incineration (ECI), an experimental waste remediation process. This report contains a general introduction to the project and the general conclusions. Four chapters have been removed for separate processing. Titles are: Chapter 2: Determination of small carboxylic acids by ion exclusion chromatography with electrospray mass spectrometry; Chapter 3: Electrochemical incineration of benzoquinone in aqueous media using a quaternary metal oxide electrode in the absence of a soluble supporting electrolyte; Chapter 4: The determination of electrochemical incineration products of 4-chlorophenol by liquid chromatography-electrospray mass spectrometry; and Chapter 5: Determination of small carboxylic acids by capillary electrophoresis with electrospray mass spectrometry.

PVA matches human liver in needle-tissue interaction.

Science.gov (United States)

de Jong, Tonke L; Pluymen, Loes H; van Gerwen, Dennis J; Kleinrensink, Gert-Jan; Dankelman, Jenny; van den Dobbelsteen, John J

2017-05-01

Medical phantoms can be used to study needle-tissue interaction and to train medical residents. The purpose of this research is to study the suitability of polyvinyl alcohol (PVA) as a liver tissue mimicking material in terms of needle-tissue interaction. Insertions into ex-vivo human livers were used for reference. Six PVA samples were created by varying the mass percentage of PVA to water (4m% and 7m%) and the number of freeze-thaw cycles (1, 2 and 3 cycles, 16hours of freezing at -19°C, 8hours of thawing). The inner needle of an 18 Gauge trocar needle with triangular tip was inserted 13 times into each of the samples, using an insertion velocity of 5 mm/s. In addition, 39 insertions were performed in two ex-vivo human livers. Axial forces on the needle were captured during insertion and retraction and characterized by friction along the needle shaft, peak forces, and number of peak forces per unit length. The concentration of PVA and the number of freeze-thaw cycles both influenced the mechanical interaction between needle and specimen. Insertions into 4m% PVA phantoms with 2 freeze-thaw cycles were comparable to human liver in terms of estimated friction along the needle shaft and the number of peak forces. Therefore, these phantoms are considered to be suitable liver mimicking materials for image-guided needle interventions. The mechanical properties of PVA hydrogels can be influenced in a controlled manner by varying the concentration of PVA and the number of freeze-thaw cycles, to mimic liver tissue characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of atmospheric pressure plasma needle jet for sterilization applications

Science.gov (United States)

Elfa, Rizan Rizon; Ahmad, Mohd Khairul; Soon, Chin Fhong; Sahdan, Mohd Zainizan; Lias, Jais; Wibowo, Kusnanto Mukti; Bakar, Ahmad Shuhaimi Abu; Arshad, Mohd Khairuddin Md; Hashim, Uda; Nayan, Nafarizal

2017-09-01

Inactivation of bacteria or sterilization has been a major issue in the medical field, especially regarding of human safety, whereby, in a huge scenario fatality can be caused by hazardous bacteria. Often, E-coli as gram-negative bacteria are selected as a key indicator of proper sterilization process as E-coli is tough and dormant bacteria. The technology in sterilization has moved on from chemical, wet and irradiation sterilization to a high promising device such as atmospheric pressure plasma needle jet (APPNJ). It has been reported that atmospheric pressure plasma has provided bundle of advantages over earlier sterilization process. The APPNJ is developed in our lab using high frequency and high voltage neon transformer power supply connected to copper needle and copper sheet electrodes. The gas discharge is Ar gas flowing at 40 L/min through a quartz glass tube. The E-coli bacteria are self-cultured from waste water and then treated with APPNJ. The treatment processes are run into two difference gaps between the plasma orifice and sample with various treatment times. Only 40s is required by direct treatment to achieve 100% killing of E-coli. On the other hand, indirect treatment has inactivated 50% of the E-coli in 40s. In this study, direct and indirect effect of APPNJ to the E-coli can be observed which can be utilized into sterilization of bio-compatible material applications.

Exploring needle anxiety among students attending a Nigerian ...

African Journals Online (AJOL)

Needle anxiety, a form of specific phobia refers to an intense fear of needles used for various medical procedures. It may result in the avoidance of such needle-involving procedures like intramuscular injections or vaccinations. About 4-8% of children and adolescents are said to generally suffer some form of anxiety.

Observations on rotating needle insertions using a brachytherapy robot

International Nuclear Information System (INIS)

Meltsner, M A; Ferrier, N J; Thomadsen, B R

2007-01-01

A robot designed for prostate brachytherapy implantations has the potential to greatly improve treatment success. Much of the research in robotic surgery focuses on measuring accuracy. However, there exist many factors that must be optimized before an analysis of needle placement accuracy can be determined. Some of these parameters include choice of the needle type, insertion velocity, usefulness of the rotating needle and rotation speed. These parameters may affect the force at which the needle interacts with the tissue. A reduction in force has been shown to decrease the compression of the prostate and potentially increase the accuracy of seed position. Rotating the needle as it is inserted may reduce frictional forces while increasing accuracy. However, needle rotations are considered to increase tissue damage due to the drilling nature of the insertion. We explore many of the factors involved in optimizing a brachytherapy robot, and the potential effects each parameter may have on the procedure. We also investigate the interaction of rotating needles in gel and suggest the rotate-cannula-only method of conical needle insertion to minimize any tissue damage while still maintaining the benefits of reduced force and increased accuracy

Insertion mechanics of bioinspired needles into soft tissues.

Science.gov (United States)

Sahlabadi, Mohammad; Khodaei, Seyedvahid; Jezler, Kyle; Hutapea, Parsaoran

2017-12-22

Most studies to date confirm that any increase in the needle insertion force increases the damage to the tissue. When it comes to brain tissue, even minor damage can cause a long-lasting traumatic brain injury. Thus there is a great demand for innovative minimally invasive needles among the medical community. In our previous studies a novel bioinspired needle design with specially designed barbs was used to perform insertion tests into Polyvinyl chloride (PVC) tissue-mimicking gels, in which it decreased the insertion force by as much as 25%. In this work, bioinspired needles were designed using a CAD software, and were then manufactured using a 3 D printer. The insertion tests into bovine brain and liver were then performed to further investigate the performance of our bioinspired needles in real tissues. Our results show that there was a 10-25% decrease in the insertion force for insertions into bovine brain, and a 35-45% reduction in the insertion force for insertions into bovine liver using the proposed bioinspired needles. The reduction in the insertion force is due to the decrease in the friction force of the bioinspired needle with the bovine tissues, and its results are consistent with our previous results.

High-pressure needle interface for thermoplastic microfluidics.

Science.gov (United States)

Chen, C F; Liu, J; Hromada, L P; Tsao, C W; Chang, C C; DeVoe, D L

2009-01-07

A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.

Computed tomography guided needle biopsy: experience from 1,300 procedures

Energy Technology Data Exchange (ETDEWEB)

Chojniak, Rubens; Isberner, Rony Klaus; Viana, Luciana Marinho; Yu, Liao Shin; Aita, Alessandro Amorim; Soares, Fernando Augusto [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Radiologia e Patologia

2006-01-15

Context and objective: computed tomography (CT) guided biopsy is widely accepted as effective and safe for diagnosis in many settings. Accuracy depends on target organ and needle type. Cutting needles present advantages over fine needles. This study presents experience from CT guided biopsies performed at an oncology center. Design and setting: retrospective study at Hospital do Cancer A. C. Camargo, Sao Paulo.Methods: 1,300 consecutive CT guided biopsies performed between July 1994 and February 2000 were analyzed. Nodules or masses were suspected as primary malignancy in 845 cases (65%) or metastatic lesion in 455 (35%). 628 lesions were thoracic, 281 abdominal, 208 retroperitoneal, 134 musculoskeletal and 49 head/neck. All biopsies were performed by one radiologist or under his supervision: 765 (59%) with 22-gauge fine-needle/aspiration technique and 535 (41%) with automated 16 or 18-gauge cutting-needle biopsy. Results: adequate samples were obtained in 70-92% of fine-needle and 93-100% of cutting-needle biopsies. The specific diagnosis rates were 54-67% for fine-needle and 82-100% for cutting-needle biopsies, according to biopsy site. For any site, sample adequacy and specific diagnosis rate were always better for cutting-needle biopsy. Among 530 lung biopsies, there were 84 pneumothorax (16%) and two hemothorax (0.3%) cases, with thoracic drainage in 24 (4.9%). Among abdominal and retroperitoneal biopsies, there were two cases of major bleeding and one of peritonitis. Conclusion: both types of needle showed satisfactory results, but cutting-needle biopsy should be used when specific diagnosis is desired without greater incidence of complications. (author)

The Problem of Metal Needles in Acupuncture-fMRI Studies

Directory of Open Access Journals (Sweden)

Florian Beissner

2011-01-01

Full Text Available Acupuncture is a therapy based on sensory stimulation of the human body by means of metal needles. The exact underlying mechanisms of acupuncture have not been clarified so far. Functional magnetic resonance imaging (fMRI has become an important tool in acupuncture research. Standard acupuncture needles, which are made of ferromagnetic steel, however, are problematic in acupuncture-fMRI studies for several reasons, such as attraction by the scanner's magnetic field, significant image distortions and signal-dropouts, when positioned close to the head or even heating due to absorption of radio frequency (RF. The aim of this study was to compare two novel types of acupuncture needles with a standard needle for their effect on MRI image quality. The standard needle severely reduced image quality, when located inside the RF coil. The nonferromagnetic metal needle may pose a risk due to RF heating, while the plastic needle has a significantly larger diameter. In conclusion, our recommendations are: (1 standard needles should not be used in MRI; (2 Nonferromagnetic metal needles seem to be the best choice for acupoints outside of the transmitter coil; and (3 only plastic needles are suited for points inside the coil. Laser acupuncture may be a safe alternative, too.

Percutaneous CT-Guided Core Needle Biopsy Versus Fine Needle Aspiration in Diagnosing Pneumonia and Mimics of Pneumonia

International Nuclear Information System (INIS)

Thanos, Loukas; Galani, Panagiota; Mylona, Sophia; Pomoni, Maria; Mpatakis, Nikolaos

2004-01-01

The purpose of this study was to determine the diagnostic value of percutaneous core needle biopsy (CNB) relative to fine needle aspiration (FNA) in patients with pneumonia and pneumonia mimics. In this prospective study we present our experience with 48 thoracic FNAs and CNBs carried out on 48 patients with pneumonia and pneumonia mimics. Samples were obtained from all patients using both CNB (with an automated 18-G core biopsy needle and a gun) and FNA (with a 22-G needle). A specific diagnosis was made in 10/48 cases (20.83%) by FNA and in 42/48 (87.5%) by CNB. The main complications encountered were pneumothorax (n = 4) and hemoptysis (n = 2), yielding a total complication rate of 12.5%. We concluded that CNB using an automated biopsy gun results in a higher diagnostic accuracy for pneumonia and pneumonia mimic biopsies than FNA. Complications should be considered and proper patient observation should follow the procedure

High-Field MRI-Compatible Needle Placement Robot for Prostate Interventions

OpenAIRE

SU, Hao; CAMILO, Alex; COLE, Gregory A.; HATA, Nobuhiko; TEMPANY, Clare M.; FISCHER, Gregory S.

2011-01-01

This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retrac...

Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules.

Science.gov (United States)

Raikov, Nikolai; Nonchev, Boyan; Chaushev, Borislav; Vjagova, Diyana; Todorov, Svetoslav; Bocheva, Yana; Malceva, Daniela; Vicheva, Snejinka; Raikova, Asyia; Argatska, Antoaneta; Raikov, Miroslav

2016-01-01

The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy.

An Exploration of the Needling Depth in Acupuncture: The Safe Needling Depth and the Needling Depth of Clinical Efficacy

Directory of Open Access Journals (Sweden)

Jaung-Geng Lin

2013-01-01

Full Text Available Objective. To explore the existing scientific information regarding safe needling depth of acupuncture points and the needling depth of clinical efficacy. Methods. We searched the PubMed, EMBASE, Cochrane, Allied and Complementary Medicine (AMED, The National Center for Complementary and Alternative Medicine (NCCAM, and China National Knowledge Infrastructure (CNKI databases to identify relevant monographs and related references from 1991 to 2013. Chinese journals and theses/dissertations were hand searched. Results. 47 studies were recruited and divided into 6 groups by measuring tools, that is, MRI, in vivo evaluation, CT, ultrasound, dissected specimen of cadavers, and another group with clinical efficacy. Each research was analyzed for study design, definition of safe depth, and factors that would affect the measured depths. Depths of clinical efficacy were discussed from the perspective of de-qi and other clinical observations. Conclusions. Great inconsistency in depth of each point measured from different subject groups and tools exists. The definition of safe depth should be established through standardization. There is also lack of researches to compare the clinical efficacy. A well-designed clinical trial selecting proper measuring tools to decide the actual and advisable needling depth for each point, to avoid adverse effects or complications and promote optimal clinical efficacy, is a top priority.

High platinum utilization in ultra-low Pt loaded PEM fuel cell cathodes prepared by electrospraying

Energy Technology Data Exchange (ETDEWEB)

Martin, S.; Garcia-Ybarra, P.L.; Castillo, J.L. [Dept. Fisica Matematica y de Fluidos, Facultad de Ciencias, UNED, Senda del Rey 9, 28040 Madrid (Spain)

2010-10-15

Cathode electrodes for proton exchange membrane fuel cells (PEMFCs) with ultra-low platinum loadings as low as 0.012 mg{sub Pt}cm{sup -2} have been prepared by the electrospray method. The electrosprayed layers have nanostructured fractal morphologies with dendrites formed by clusters (about 100 nm diameter) of a few single catalyst particles rendering a large exposure surface of the catalyst. Optimization of the control parameters affecting this morphology has allowed us to overcome the state of the art for efficient electrodes prepared by electrospraying. Thus, using these cathodes in membrane electrode assemblies (MEAs), a high platinum utilization in the range 8-10 kW g{sup -1} was obtained for the fuel cell operating at 40 C and atmospheric pressure. Moreover, a platinum utilization of 20 kW g{sup -1} was attained under more suitable operating conditions (70 C and 3.4 bar over-pressure). These results substantially improve the performances achieved previously with other low platinum loading electrodes prepared by electrospraying. (author)

Ultrasound guided percutaneous fine needle aspiration biopsy ...

African Journals Online (AJOL)

)-guided percutaneous fine needle aspiration biopsy (PFNAB)/US-guided percutaneous needle core biopsy (PNCB) of abdominal lesions is efficacious in diagnosis, is helpful in treatment choice, to evaluate whether various other investigations ...

A retrospective analysis of ultrasound-guided large core needle ...

African Journals Online (AJOL)

2016-07-27

Jul 27, 2016 ... The different types of non-surgical breast biopsy procedures include: fine needle aspiration biopsy. (FNAB), core needle ... needle biopsies of breast lesions at a regional public hospital in ..... NCR_2009_FINAL.pdf. 2. Parikh J ...

Laser-Controlled Growth of Needle-Shaped Organic Nanoaggregates

DEFF Research Database (Denmark)

Balzer, Frank; Rubahn, Horst-Günter

2002-01-01

Arrays of mutually parallel oriented, single-crystalline, needle-like structures of light-emitting p-hexaphenyl molecules are generated in the focus of an argon ion laser. The cross sectional dimensions of the needles are of the order of 100 to 200 nm with lengths up to several hundred micrometer....... While the orientation of the individual molecules in the needles is defined by the direction of surface dipoles, the localization on the surface, the length distribution as well as mutual distances can be adjusted via size and position of the laser focus spot.......Arrays of mutually parallel oriented, single-crystalline, needle-like structures of light-emitting p-hexaphenyl molecules are generated in the focus of an argon ion laser. The cross sectional dimensions of the needles are of the order of 100 to 200 nm with lengths up to several hundred micrometers...

A comparison of ultrasound guided fine needle aspiration cytology and core needle biopsy in evaluation of palpable breast lesions

International Nuclear Information System (INIS)

Altaf, H.N.; Farooqui, F.

2015-01-01

Objective: To compare ultrasound guided fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) in patients presenting with palpable breast lumps (PBLs), in terms of sensitivity and specificity, taking final histopathology as gold standard. Methodology: This cross-sectional study was conducted at Holy Family Hospital, Rawalpindi, Pakistan. Ultrasound guided FNAC and CNB were taken of all female patients with PBLs. The results were compared with final histopathology as gold standard. Data analysis was performed using SPSS software and chi-square test. Results: A total of 60 patients were included in the study. The mean age was 33.8 yrs. The sensitivity and specificity of ultrasound guided FNAC were 68.7% and 93.1%, respectively. The sensitivity and specificity of ultrasound guided CNB was 93.7% and 100%. The accuracy of FNAC was 86.2% and that of core needle biopsy was 98.3%. Conclusion: The ultrasound guided core needle biopsy can be used as an initial diagnostic test for the evaluation of all PBLs. Because of high negative predictive value core needle biopsy can replace surgical excision biopsy for benign lesions. (author)

Quantification of Tissue Trauma following Insulin Pen Needle Insertions in Skin

DEFF Research Database (Denmark)

Jensen, Casper Bo; Larsen, Rasmus; Vestergaard, Jacob Schack

Objective: Within the field of pen needle development, most research on needle design revolves around mechanical tensile testing and patient statements. Only little has been published on the actual biological skin response to needle insertions. The objective of this study was to develop a computa......Objective: Within the field of pen needle development, most research on needle design revolves around mechanical tensile testing and patient statements. Only little has been published on the actual biological skin response to needle insertions. The objective of this study was to develop...... a computational method to quantify tissue trauma based on skin bleeding and immune response. Method: Two common sized pen needles of 28G (0.36mm) and 32G (0.23mm) were inserted into skin of sedated LYD pigs prior to termination. Four pigs were included and a total of 32 randomized needle insertions were conducted...... diameter. Conclusion: A computational and quantitative method has been developed to assess tissue trauma following insulin pen needle insertions. Application of the method is tested by conduction of a needle diameter study. The obtained quantitative measures of tissue trauma correlate positively to needle...

High-Field MRI-Compatible Needle Placement Robot for Prostate Interventions

Science.gov (United States)

SU, Hao; CAMILO, Alex; COLE, Gregory A.; HATA, Nobuhiko; TEMPANY, Clare M.; FISCHER, Gregory S.

2014-01-01

This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retraction to enable the brachytherapy procedure with the preloaded needles. The device mimics the manual physician gesture by two point grasping (hub and base) and provides direct force measurement of needle insertion force by fiber optic force sensors. The fabricated prototype is presented and an experiment with phantom trials in 3T MRI is analyzed to demonstrate the system compatibility. PMID:21335868

Novel electrosprayed nanospherules for enhanced aqueous solubility and oral bioavailability of poorly water-soluble fenofibrate

Directory of Open Access Journals (Sweden)

Yousaf AM

2016-01-01

Full Text Available Abid Mehmood Yousaf,1,2 Omer Mustapha,1 Dong Wuk Kim,1 Dong Shik Kim,1 Kyeong Soo Kim,1 Sung Giu Jin,1 Chul Soon Yong,3 Yu Seok Youn,4 Yu-Kyoung Oh,5 Jong Oh Kim,3 Han-Gon Choi1 1College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Gyeonggi, South Korea; 2Faculty of Pharmacy, University of Central Punjab, Johar, Lahore, Pakistan; 3College of Pharmacy, Yeungnam University, Gyongsan, North Gyeongsang, 4School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi, 5College of Pharmacy, Seoul National University, Seoul, South Korea Purpose: The purpose of the present research was to develop a novel electrosprayed nanospherule providing the most optimized aqueous solubility and oral bioavailability for poorly water-soluble fenofibrate.Methods: Numerous fenofibrate-loaded electrosprayed nanospherules were prepared with polyvinylpyrrolidone (PVP and Labrafil® M 2125 as carriers using the electrospray technique, and the effect of the carriers on drug solubility and solvation was assessed. The solid state characterization of an optimized formulation was conducted by scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopic analyses. Oral bioavailability in rats was also evaluated for the formulation of an optimized nanospherule in comparison with free drug and a conventional fenofibrate-loaded solid dispersion.Results: All of the electrosprayed nanospherule formulations had remarkably enhanced aqueous solubility and dissolution compared with free drug. Moreover, Labrafil M 2125, a surfactant, had a positive influence on the solubility and dissolution of the drug in the electrosprayed nanospherule. Increases were observed as the PVP/drug ratio increased to 4:1, but higher ratios gave no significant increases. In particular, an electrosprayed nanospherule composed of fenofibrate, PVP, and Labrafil M 2125 at the weight ratio of 1

Structure and photoluminescence properties of Ag-coated ZnO nano-needles

Energy Technology Data Exchange (ETDEWEB)

Li Xiaozhu, E-mail: Lixiaozhu1019@21cn.com [Department of Physics, Shaoguan University, Shaoguan, Guangdong 512005 (China) and Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan, Hubei 430072 (China); Wang Yongqian [Engineering Research Center of Nano-Geomaterials of Ministry of Education (China University of Geosciences), Wuhan, Hubei 430074 (China)

2011-05-12

Highlights: > ZnO nano-needles were synthesized by thermal oxidation. > Their surfaces were coated with Ag by pulse electro-deposition technique. > The uncoated and coated ZnO nano-needles were characterized. > The results showed that the prepared ZnO nano-needles have been coated with Ag successfully. > The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the Ag-coated ZnO nano-needles can increase the absorption of UV light. - Abstract: A large number of zinc oxide (ZnO) nano-needles were synthesized by thermal oxidation of pure zinc. The surfaces of ZnO nano-needles were coated with a layer of Ag by pulse electro-deposition technique. The uncoated and coated ZnO nano-needles were characterized by using the X-ray diffraction and the scanning electron microscope (SEM). The results showed that the uncoated samples were close-packed hexagonal structure, which showed needle-like morphology. Their average diameter is about 40 nm, lengths up to 5 {mu}m. At the same time we observed that the prepared ZnO nano-needles have been coated with Ag successfully. The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the uncoated ZnO nano-needles have two fluorescence peaks at 388 nm and 470.8 nm, respectively, the relative intensity of 143.4 and 93.61; and the Ag-coated ZnO nano-needles showed a pair of strong peaks at 387.4 nm and 405.2 nm, the relative intensity of 1366 and 1305, respectively, indicating that the Ag-coated ZnO nano-needles can increase the absorption of UV light.

Master-slave robotic system for needle indentation and insertion.

Science.gov (United States)

Shin, Jaehyun; Zhong, Yongmin; Gu, Chengfan

2017-12-01

Bilateral control of a master-slave robotic system is a challenging issue in robotic-assisted minimally invasive surgery. It requires the knowledge on contact interaction between a surgical (slave) robot and soft tissues. This paper presents a master-slave robotic system for needle indentation and insertion. This master-slave robotic system is able to characterize the contact interaction between the robotic needle and soft tissues. A bilateral controller is implemented using a linear motor for robotic needle indentation and insertion. A new nonlinear state observer is developed to online monitor the contact interaction with soft tissues. Experimental results demonstrate the efficacy of the proposed master-slave robotic system for robotic needle indentation and needle insertion.

Possibilities of the chemical analysis of Scots pine (Pinus sylvestris) needles

International Nuclear Information System (INIS)

Viksna, A.

1999-01-01

Scots pine (Pinus sylvestris L.) is a good bio indicator. This species is widely distributed in Europe, including Latvia, is easily identified, and is used in bio indication studies. It is known that the concentrations of most elements in needles change with time. These changes are connected to the processes involved in the uptake, transportation, storage and retranslocation of the elements. Scots pine keeps their needles for several years (3 to 4 years) and are suitable for the study of time related processes. The chemical composition of pine needles is used for the study the deposition and impact of air pollutants. Coniferous needles are covered with epicuticular wax, which act as a trap for airborne deposits. A comparison of chemical composition of pine needles that were unwashed and washed with chloroform made it possible to distinguish which elements were on the needles and to evaluate the character of pollution. The most important stage of the analysis of pine needles is sampling. Nutrient concentrations in the needles of coniferous trees have been shown to vary with the needle age and tree age, the phase of the annual physiological cycle, availability of nutrients in the soil and needle position within the crown. It is very important to take representative sample for the analysis. In the current work the trace element concentrations of the single needle were analysed by electrothermal atomic absorption spectrometry (ETAAS) and total reflection X-ray spectrometry (TXRF). The results of analysis showed that concentration of some elements depends from the position of needle within branch for the same needle age class. The concentrations of trace elements in the single needles within main shoot were more or less constant compare with other order shoots at given needle age class. Some higher variations in the elemental concentrations between single needles were observed in the tip part of main shoot. The actual distribution of the elements within a needle has

Robotic needle steering: design, modeling, planning, and image guidance

NARCIS (Netherlands)

Cowan, Noah J.; Goldberg, Ken; Chirikjian, Gregory S.; Fichtinger, Gabor; Alterovitz, Ron; Reed, Kyle B.; Kallem, Vinutha; Misra, Sarthak; Park, Wooram; Okamura, Allison M.; Rosen, Jacob; Hannaford, Blake; Satava, Richard M.

2010-01-01

This chapter describes how advances in needle design, modeling, planning, and image guidance make it possible to steer flexible needles from outside the body to reach specified anatomical targets not accessible using traditional needle insertion methods. Steering can be achieved using a variety of

Coupling of gas chromatography and electrospray ionization high resolution mass spectrometry for the analysis of anabolic steroids as trimethylsilyl derivatives in human urine.

Science.gov (United States)

Cha, Eunju; Jeong, Eun Sook; Cha, Sangwon; Lee, Jaeick

2017-04-29

In this study, gas chromatography (GC) was interfaced with high resolution mass spectrometry (HRMS) with electrospray ionization source (ESI) and the relevant parameters were investigated to enhance the ionization efficiency. In GC-ESI, the distances (x-, y- and z) and angle between the ESI needle, GC capillary column and MS orifice were set to 7 (x-distance), 4 (y-distance), and 1 mm (z-distance). The ESI spray solvent, acid modifier and nebulizer gas flow were methanol, 0.1% formic acid and 5 arbitrary units, respectively. Based on these results, analytical conditions for GC-ESI/HRMS were established. In particular, the results of spray solvent flow indicated a concentration-dependent mechanism (peak dilution effect), and other parameters also greatly influenced the ionization performance. The developed GC-ESI/HRMS was then applied to the analysis of anabolic steroids as trimethylsilyl (TMS) derivatives in human urine to demonstrate its application. The ionization profiles of TMS-derivatized steroids were investigated and compared with those of underivatized steroids obtained from gas chromatography-electrospray ionization/mass spectrometry (GC-ESI/MS) and liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS). The steroids exhibited ionization profiles based on their structural characteristics, regardless of the analyte phase or derivatization. Groups I and II with conjugated or unconjugated keto functional groups at C3 generated the [M+H] + and [M+H-TMS] + ions, respectively. On the other hand, Groups III and IV gave rise to the characteristic fragment ions [M+H-TMS-H 2 O] + and [M+H-2TMS-H 2 O] + , corresponding to loss of a neutral TMS·H 2 O moiety from the protonated molecular ion by in-source dissociation. To the best of our knowledge, this is the first study to successfully ionize and analyze steroids as TMS derivatives using ESI coupled with GC. The present system has enabled the ionization of TMS derivatives under ESI conditions

[Novel echogenic needle for ultrasound-guided peripheral nerve block "Hakko type CCR"].

Science.gov (United States)

Takayama, Wataru; Yasumura, Rie; Kaneko, Takehiko; Kobayashi, Yoshiro; Kamada, Takaaki; Yoshikawa, Tamotsu; Aoyama, Yasuhiko

2009-04-01

A novel echogenic insulated nerve block needle (CCR-needle: Echogenic Needle Type CCR; Hakko, Japan) is commercially available since 2006 in Japan. This needle has three echogenic dimples, namely corner cube reflectors (CCR) on its tip. The CCR-needle will potentially provide a significant advantage for detecting the needle tip. In this report, we firstly evaluated this new disposable echogenic needle in simulation phantom, and demonstrated improved visibility of the needle tip. Afterwards, an interscalene brachial plexus block was performed on a male patient undergoing shoulder surgery. The needle insertion procedure was the "out of plane" ultrasound-guided technique using simultaneous electrical nerve stimulation. The surgery was successfully conducted without any complications.

Endoscopic Ultrasound Guided Rendezvous Drainage of Biliary Obstruction Using a New Flexible 19-Gauge Fine Needle Aspiration Needle.

Science.gov (United States)

Tang, Zhouwen; Igbinomwanhia, Efehi; Elhanafi, Sherif; Othman, Mohamed O

2016-01-01

Background and Aim. A successful endoscopic ultrasound guided rendezvous (EUS-RV) biliary drainage is dependent on accurate puncture of the bile duct and precise guide wire manipulation across the ampulla of Vater. We aim to study the feasibility of using a flexible 19-gauge fine aspiration needle in the performance of EUS-RV biliary drainage. Method. This is a retrospective case series of EUS-RV biliary drainage procedures at a single center. Patients who failed ERCP during the same session for benign or malignant biliary obstruction underwent EUS-RV using a flexible, nitinol covered, 19-gauge needle for biliary access and guide wire manipulation. Result. 24 patients underwent EUS-RV biliary drainage via extrahepatic access while 1 attempt was via intrahepatic access. The technical success rate was 80%, including 83.3% of cases via extrahepatic access. There was no significant difference in success rate of inpatient and outpatient procedures, benign or malignant indications, or type of guide wire used. Adverse events included mild pancreatitis (3 patients) and cholangitis (1 patient). Conclusion. A flexible 19-gauge needle for biliary access can be safe and effective when used to perform EUS-RV biliary drainage. Direct comparison between the nitinol needle and conventional metal needles in the performance of EUS guided biliary drainage is needed.

NUTRIENTS CONCENTRATION AND RETRANSLOCATION IN THE Pinus taeda L. NEEDLES

Directory of Open Access Journals (Sweden)

Márcio Viera

2010-03-01

Full Text Available Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old in Cambará do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West, sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients. The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.

Novel Double-Needle System That Can Prevent Intravascular Injection of Any Filler

Directory of Open Access Journals (Sweden)

Hsiang Huang, MD

2017-09-01

Full Text Available Summary:. A new type of needle system combines 2 parts, an inner needle and an outer needle. The inner needle is used for filler injection and the outer needle acts as a guiding needle that can observe blood reflow when inserting into the vessel lumen during injection process. This new needle system can be used for all kinds of filler, providing real time monitoring for physician and preventing intravascular injection of any filler.

Characterisation of tryptic peptides of phosphorylated tyrosine hydroxylase by high-pressure liquid chromatography electrospray ionisation mass spectrometry

International Nuclear Information System (INIS)

Graham, Mark E.; Dickson, Phillip W.; Dunkley, Peter R.; Nagy-Felsobuki, Ellak I. von

2005-01-01

Tyrosine hydroxylase (TH) is involved in the biosynthesis of catecholamines and is activated by phosphorylation. Phosphorylated TH was analysed using high-pressure liquid chromatography combined with electrospray mass spectrometry (HPLC ESI-MS). Two mass scanning methods were used to detect tryptic cleavage products of TH. In the positive electrospray ionisation mode (ESI+), the peptides that contain the phosphorylation sites of TH were identified. In the alternative method, a phosphopeptide was detected in the negative electrospray ionisation mode (ESI-) using single ion monitoring in combination with a sequential ESI+ switching experiment. A raised baseline interfered with detection of hydrophilic peptides in ESI-, with the signal-to-noise ratio indicating that the method was operating near the limit of detection for a conventional electrospray source. The switching method improved the certainty of identification of phosphopeptides

Torsional Dynamics of Steerable Needles: Modeling and Fluoroscopic Guidance

Science.gov (United States)

Swensen, John P.; Lin, MingDe; Okamura, Allison M.; Cowan, Noah J.

2017-01-01

Needle insertions underlie a diversity of medical interventions. Steerable needles provide a means by which to enhance existing needle-based interventions and facilitate new ones. Tip-steerable needles follow a curved path and can be steered by twisting the needle base during insertion, but this twisting excites torsional dynamics that introduce a discrepancy between the base and tip twist angles. Here, we model the torsional dynamics of a flexible rod—such as a tip-steerable needle—during subsurface insertion and develop a new controller based on the model. The torsional model incorporates time-varying mode shapes to capture the changing boundary conditions inherent during insertion. Numerical simulations and physical experiments using two distinct setups—stereo camera feedback in semi-transparent artificial tissue and feedback control with real-time X-ray imaging in optically opaque artificial tissue— demonstrate the need to account for torsional dynamics in control of the needle tip. PMID:24860026

Structure and photoluminescence properties of Ag-coated ZnO nano-needles

International Nuclear Information System (INIS)

Li Xiaozhu; Wang Yongqian

2011-01-01

Highlights: → ZnO nano-needles were synthesized by thermal oxidation. → Their surfaces were coated with Ag by pulse electro-deposition technique. → The uncoated and coated ZnO nano-needles were characterized. → The results showed that the prepared ZnO nano-needles have been coated with Ag successfully. → The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the Ag-coated ZnO nano-needles can increase the absorption of UV light. - Abstract: A large number of zinc oxide (ZnO) nano-needles were synthesized by thermal oxidation of pure zinc. The surfaces of ZnO nano-needles were coated with a layer of Ag by pulse electro-deposition technique. The uncoated and coated ZnO nano-needles were characterized by using the X-ray diffraction and the scanning electron microscope (SEM). The results showed that the uncoated samples were close-packed hexagonal structure, which showed needle-like morphology. Their average diameter is about 40 nm, lengths up to 5 μm. At the same time we observed that the prepared ZnO nano-needles have been coated with Ag successfully. The photoluminescence spectrums of ZnO nano-needles with Ag-coated and uncoated were analyzed, finding that the uncoated ZnO nano-needles have two fluorescence peaks at 388 nm and 470.8 nm, respectively, the relative intensity of 143.4 and 93.61; and the Ag-coated ZnO nano-needles showed a pair of strong peaks at 387.4 nm and 405.2 nm, the relative intensity of 1366 and 1305, respectively, indicating that the Ag-coated ZnO nano-needles can increase the absorption of UV light.

Robust path planning for flexible needle insertion using Markov decision processes.

Science.gov (United States)

Tan, Xiaoyu; Yu, Pengqian; Lim, Kah-Bin; Chui, Chee-Kong

2018-05-11

Flexible needle has the potential to accurately navigate to a treatment region in the least invasive manner. We propose a new planning method using Markov decision processes (MDPs) for flexible needle navigation that can perform robust path planning and steering under the circumstance of complex tissue-needle interactions. This method enhances the robustness of flexible needle steering from three different perspectives. First, the method considers the problem caused by soft tissue deformation. The method then resolves the common needle penetration failure caused by patterns of targets, while the last solution addresses the uncertainty issues in flexible needle motion due to complex and unpredictable tissue-needle interaction. Computer simulation and phantom experimental results show that the proposed method can perform robust planning and generate a secure control policy for flexible needle steering. Compared with a traditional method using MDPs, the proposed method achieves higher accuracy and probability of success in avoiding obstacles under complicated and uncertain tissue-needle interactions. Future work will involve experiment with biological tissue in vivo. The proposed robust path planning method can securely steer flexible needle within soft phantom tissues and achieve high adaptability in computer simulation.

[Doctor HUANG Shi-ping's acupuncture with golden needles].

Science.gov (United States)

Chen, Teng-Fei; Ma, Zeng-Bin; Xin, Si-Yuan; Zhu, Jiang

2013-08-01

Taking Doctor HUANG Shi-ping as the representative, the school of Huang's golden needle is based on Chinese martial art. Golden needles are adopted as main tool. Attaching great importance on the combination of acupuncture and moxibustioin, it is also characterized with penetrating needling with long needles. Through the development of three generations, it once outshone other schools in the field of acupuncture, and became famous all over the world. It made great contribution to the development of the course of acupuncture. However, with the development of the history, the form of acupuncture education as well as apparatus were all undergone an unified reform. Therefore, Doctor HUANG Shi-ping's acupuncture school be lost gradually.

Diagenesis of conifer needles in a coastal marine environment

Science.gov (United States)

Hedges, John I.; Weliky, K.

1989-10-01

Physically intact fir, hemlock and cedar needles were isolated from different horizons of a sediment core from a coastal marine bay (Dabob Bay, Washington State, U.S.A.) and from nearby trees and forest litter. Green fir, hemlock and cedar needles were all characterized by glucose-rich aldose mixtures (~30% of tissue carbon), the production of vanillyl and cinnamyl CuO-derived phenols (~8% of tissue carbon) and the presence of both pinitol and myo-inositol (1-2% of tissue carbon). Needles from forest litter were enriched in lignin phenols and non-glucose aldoses and depleted in glucose and cyclitols. The sediment core contained an average of 10 mg/1 of physically intact fir, hemlock and cedar needles, which occurred in similar relative abundances and accounted for less than 1% of the total nonwoody gymnosperm tissue. Compared to the green and litter counterparts, all sedimentary needles were greatly depleted in cyclitols, glucose and p-coumaric acid and enriched in vanillyl phenol precursors. The degree of elevation of vanillyl phenol yield from the degraded needles was used to estimate minimal carbon losses from the samples, which ranged from near 40% for needle litter to almost 70% for the deepest (~100 years old) sedimentary fir/hemlock samples. Although downcore increases in carbon loss and refractory organic components indicated in situ diagenesis, the bulk of overall degradation occurred either on land or during the first 10-20 years after deposition. Atomic C/N ratios of degraded needles were lower than for green counterparts, but nitrogen was lost overall. These relative changes indicate the following stability series: vanillyl phenols > N > ferulic acid, p-hydroxy phenols, most aldoses and bulk tissue > glucose and p-coumaric acid > cyclitols (near 100% loss). Vanillic acid to vanillin ratios, (Ad/Al)v, of the green fir and hemlock needles were unusually high (0.36-0.38) and decreased downcore. Diagenesis also decreased the cinnamyl/vanillyl phenol ratio

Microfluidic Array of Externally Fed Electrospray Thrusters for Micro-Propulsion

Data.gov (United States)

National Aeronautics and Space Administration — The goal of this proposal is to design an electrospray micropropulsion thruster that utilizes a novel propellant transport mechanism. This project is a collaboration...

Freehand biopsy guided by electromagnetic needle tracking

DEFF Research Database (Denmark)

Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann

2011-01-01

To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....

Rooting of needle fascicles from western white pine seedlings

Science.gov (United States)

Ramond J. Hoff; Geral I. McDonald

1968-01-01

In one test, 45 out of 318 (14 percent) needle fascicles from 2-year-old seedlings of Pinus monticola Dougl. were rooted. Eight of the needle fascicles produced shoot growth. In another test, 392 out of 742 (53 percent) needle fascicles were rooted, but none of these produced shoot growth.

Smart surgical needle actuated by shape memory alloys for percutaneous procedures

Science.gov (United States)

Konh, Bardia

Background: Majority of cancer interventions today are performed percutaneously using needle-based procedures, i.e. through the skin and soft tissue. Insufficient accuracy using conventional surgical needles motivated researchers to provide actuation forces to the needle's body for compensating the possible errors of surgeons/physicians. Therefore, active needles were proposed recently where actuation forces provided by shape memory alloys (SMAs) are utilized to assist the maneuverability and accuracy of surgical needles. This work also aims to introduce a novel needle insertion simulation to predict the deflection of a bevel tip needle inside the tissue. Methods: In this work first, the actuation capability of a single SMA wire was studied. The complex response of SMAs was investigated via a MATLAB implementation of the Brinson model and verified via experimental tests. The material characteristics of SMAs were simulated by defining multilinear elastic isothermal stress-strain curves. Rigorous experiments with SMA wires were performed to determine the material properties as well as to show the capability of the code to predict a stabilized SMA transformation behavior with sufficient accuracy. The isothermal stress-strain curves of SMAs were simulated and defined as a material model for the Finite Element Analysis of the active needle. In the second part of this work, a three-dimensional finite element (FE) model of the active steerable needle was developed to demonstrate the feasibility of using SMA wires as actuators to bend the surgical needle. In the FE model, birth and death method of defining boundary conditions, available in ANSYS, was used to achieve the pre-strain condition on SMA wire prior to actuation. This numerical model was validated with needle deflection experiments with developed prototypes of the active needle. The third part of this work describes the design optimization of the active using genetic algorithm aiming for its maximum flexibility

An interior needle electropolymerized pyrrole-based coating for headspace solid-phase dynamic extraction

Energy Technology Data Exchange (ETDEWEB)

Bagheri, Habib [Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)], E-mail: bagheri@sharif.edu; Babanezhad, Esmaeil; Khalilian, Faezeh [Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

2009-02-23

A headspace solid-phase dynamic extraction (HS-SPDE) technique was developed by the use of polypyrrole (PPy) sorbent, electropolymerized inside the surface of a needle, as a possible alternative to solid-phase microextraction (SPME). Thermal desorption was subsequently, employed to transfer the extracted analytes into the injection port of a gas chromatography-mass spectrometry (GC-MS). The PPy sorbent including polypyrrole-dodecyl sulfate (PPy-DS) was deposited on the interior surface of a stainless steel needle from the corresponding aqueous electrolyte by applying a constant deposition potential. The homogeneity and the porous surface structure of the coating were examined using the scanning electron microscopy (SEM). The developed method was applied to the trace level extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample. In order to enhance the extraction efficiency and increase the partition coefficient of analytes, the stainless steel needle was cooled at 5 deg. C, while the sample solution was kept at 80 deg. C. Optimization of influential experimental conditions including the voltage of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic strength and the extraction time were also investigated. The detection limits of the method under optimized conditions were in the range of 0.002-0.01 ng mL{sup -1}. The relative standard deviations (R.S.D.) at a concentration level of 0.1 ng mL{sup -1} were obtained between 7.54 and 11.4% (n = 6). The calibration curves of PAHs showed linearity in the range of 0.01-10 ng mL{sup -1}. The proposed method was successfully applied to the extraction of some selected PAHs from real-life water samples and the relative recoveries were higher than 90% for all the analytes.

Needle Decompression of Tension Pneumothorax with Colorimetric Capnography.

Science.gov (United States)

Naik, Nimesh D; Hernandez, Matthew C; Anderson, Jeff R; Ross, Erika K; Zielinski, Martin D; Aho, Johnathon M

2017-11-01

The success of needle decompression for tension pneumothorax is variable, and there are no objective measures assessing effective decompression. Colorimetric capnography, which detects carbon dioxide present within the pleural space, may serve as a simple test to assess effective needle decompression. Three swine underwent traumatically induced tension pneumothorax (standard of care, n = 15; standard of care with needle capnography, n = 15). Needle thoracostomy was performed with an 8-cm angiocatheter. Similarly, decompression was performed with the addition of colorimetric capnography. Subjective operator assessment of decompression was recorded and compared with true decompression, using thoracoscopic visualization for both techniques. Areas under receiver operating curves were calculated and pairwise comparison was performed to assess statistical significance (P pneumothorax, that is, the absence of any pathologic/space-occupying lesion, in 100% of cases (10 of 10 attempts). Standard of care needle decompression was detected by operators in 9 of 15 attempts (60%) and was detected in 3 of 10 attempts when tension pneumothorax was not present (30%). True decompression, under direct visualization with thoracoscopy, occurred 15 of 15 times (100%) with capnography, and 12 of 15 times (80%) without capnography. Areas under receiver operating curves were 0.65 for standard of care and 1.0 for needle capnography (P = .002). Needle decompression with colorimetric capnography provides a rapid, effective, and highly accurate method for eliminating operator bias for tension pneumothorax decompression. This may be useful for the treatment of this life-threatening condition. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

The longitudinal distribution of elements in developing and aging scots pine needles

International Nuclear Information System (INIS)

Viksna, A.; Helmisaari, H.S.; Standzenieks, P.; Lindgren, E.S.

2001-01-01

Needle or leaf nutrient concentrations are commonly used for analysing tree nutritional status for e.g. estimating possible nutrient deficiencies or unbalances. The practise used e.g. in northern Europe is to sample needles during the dormant period from either the current or in some cases several needle age classes from a fixed position of a number of trees in a stand. The sampled needles are then dried and ground for nutrient analysis. The sampling aims to minimise the spatial and temporal variation in needle nutrient concentrations for estimating the availability of nutrients in soil through needle analysis. It is well known that the concentrations of different nutrients vary in needles with the phase of the annual physiological cycle (Fife and Nambiar 1982, 1984), needle age (Florence and Chuoung 1974, Madgwick et al. 1983) and sampling position (Helmisaari 1992). The samples analysed are usually bulk samples of a large number of needles, and the results are mean concentrations representing an age class in a stand. There is little information on how different needles vary in nutrient concentrations, and even less on how nutrient concentrations vary within individual needles. The import and export of elements to and from needles varies according to the developmental phase of needles, and is likely to affect the element concentrations in different parts of the needles. Accordingly, the elemental concentrations measured in different parts of the needles may give an insight into the transport pattern of an element and its potential mobility. Up to now, very few studies report needle element concentrations in different parts of the needles, e.g. tip, base and middle (Giertych et al. 1997), or in different parts of the leaf phloem (Eschrich et al. 1988). The aim of this study was to determine the distribution of different elements along the length of single Scots pine needles of different age and during different stages of needle physiological cycle. The scanning

Sugar export limits size of conifer needles

DEFF Research Database (Denmark)

Rademaker, Hanna; Zwieniecki, Maciej A.; Bohr, Tomas

2017-01-01

Plant leaf size varies by more than three orders of magnitude, from a few millimeters to over one meter. Conifer leaves, however, are relatively short and the majority of needles are no longer than 6 cm. The reason for the strong confinement of the trait-space is unknown. We show that sugars...... does not contribute to sugar flow. Remarkably, we find that the size of the active part does not scale with needle length. We predict a single maximum needle size of 5 cm, in accord with data from 519 conifer species. This could help rationalize the recent observation that conifers have significantly...

CUDA accelerated simulation of needle insertions in deformable tissue

International Nuclear Information System (INIS)

Patriciu, Alexandru

2012-01-01

This paper presents a stiff needle-deformable tissue interaction model. The model uses a mesh-less discretization of continuum; avoiding thus the expensive remeshing required by the finite element models. The proposed model can accommodate both linear and nonlinear material characteristics. The needle-deformable tissue interaction is modeled through fundamental boundaries. The forces applied by the needle on the tissue are divided in tangent forces and constraint forces. The constraint forces are adaptively computed such that the material is properly constrained by the needle. The implementation is accelerated using NVidia CUDA. We present detailed analysis of the execution timing in both serial and parallel case. The proposed needle insertion model was integrated in a custom software that loads DICOM images, generate the deformable model, and can simulate different insertion strategies.

Precision grid and hand motion for accurate needle insertion in brachytherapy

International Nuclear Information System (INIS)

McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J.

2011-01-01

Purpose: In prostate brachytherapy, a grid is used to guide a needle tip toward a preplanned location within the tissue. During insertion, the needle deflects en route resulting in target misplacement. In this paper, 18-gauge needle insertion experiments into phantom were performed to test effects of three parameters, which include the clearance between the grid hole and needle, the thickness of the grid, and the needle insertion speed. Measurement apparatus that consisted of two datum surfaces and digital depth gauge was developed to quantify needle deflections. Methods: The gauge repeatability and reproducibility (GR and R) test was performed on the measurement apparatus, and it proved to be capable of measuring a 2 mm tolerance from the target. Replicated experiments were performed on a 2 3 factorial design (three parameters at two levels) and analysis included averages and standard deviation along with an analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: Results showed that grid with tight clearance hole and slow needle speed increased precision and accuracy of needle insertion. The tight grid was vital to enhance precision and accuracy of needle insertion for both slow and fast insertion speed; additionally, at slow speed the tight, thick grid improved needle precision and accuracy. Conclusions: In summary, the tight grid is important, regardless of speed. The grid design, which shows the capability to reduce the needle deflection in brachytherapy procedures, can potentially be implemented in the brachytherapy procedure.

Inserting needles into the body: a meta-analysis of brain activity associated with acupuncture needle stimulation.

Science.gov (United States)

Chae, Younbyoung; Chang, Dong-Seon; Lee, Soon-Ho; Jung, Won-Mo; Lee, In-Seon; Jackson, Stephen; Kong, Jian; Lee, Hyangsook; Park, Hi-Joon; Lee, Hyejung; Wallraven, Christian

2013-03-01

Acupuncture is a therapeutic treatment that is defined as the insertion of needles into the body at specific points (ie, acupoints). Advances in functional neuroimaging have made it possible to study brain responses to acupuncture; however, previous studies have mainly concentrated on acupoint specificity. We wanted to focus on the functional brain responses that occur because of needle insertion into the body. An activation likelihood estimation meta-analysis was carried out to investigate common characteristics of brain responses to acupuncture needle stimulation compared to tactile stimulation. A total of 28 functional magnetic resonance imaging studies, which consisted of 51 acupuncture and 10 tactile stimulation experiments, were selected for the meta-analysis. Following acupuncture needle stimulation, activation in the sensorimotor cortical network, including the insula, thalamus, anterior cingulate cortex, and primary and secondary somatosensory cortices, and deactivation in the limbic-paralimbic neocortical network, including the medial prefrontal cortex, caudate, amygdala, posterior cingulate cortex, and parahippocampus, were detected and assessed. Following control tactile stimulation, weaker patterns of brain responses were detected in areas similar to those stated above. The activation and deactivation patterns following acupuncture stimulation suggest that the hemodynamic responses in the brain simultaneously reflect the sensory, cognitive, and affective dimensions of pain. This article facilitates a better understanding of acupuncture needle stimulation and its effects on specific activity changes in different brain regions as well as its relationship to the multiple dimensions of pain. Future studies can build on this meta-analysis and will help to elucidate the clinically relevant therapeutic effects of acupuncture. Copyright © 2013 American Pain Society. All rights reserved.

Heat-pump performance: voltage dip/sag, under-voltage and over-voltage

Directory of Open Access Journals (Sweden)

William J.B. Heffernan

2014-12-01

Full Text Available Reverse cycle air-source heat-pumps are an increasingly significant load in New Zealand and in many other countries. This has raised concern over the impact wide-spread use of heat-pumps may have on the grid. The characteristics of the loads connected to the power system are changing because of heat-pumps. Their performance during under-voltage events such as voltage dips has the potential to compound the event and possibly cause voltage collapse. In this study, results from testing six heat-pumps are presented to assess their performance at various voltages and hence their impact on voltage stability.

Does the effect of acupuncture depend on needling sensation and manipulation?

Science.gov (United States)

Choi, Yu-Jin; Lee, Jae-Eun; Moon, Won-Kyung; Cho, Seung-Hun

2013-06-01

Acupuncture sensation and manipulation have been considered to be an important component of acupuncture in traditional Asian medicine. However, there has been limited research as to whether acupuncture sensation is associated with therapeutic benefit. This study investigated the relationship between acupuncture sensation and analgesic effect according to acupuncture manipulation. Fifty-three healthy volunteers received three different forms of acupuncture in a single-blinded crossover design: superficial needling (0.3 cm), deep needling (2 cm) and needling with bi-directional rotation. The effects of acupuncture were evaluated by using the pressure pain threshold. Acupuncture sensation measurement was done in two ways. Both total acupuncture sensation and increase of the pressure pain threshold were maximum in needling with rotation, followed by deep needling and superficial needling. Repeated-measure analysis of variance (ANOVA) analysis was carried out to assess whether there was a significant difference; both showed significant difference (p = 0.000, 0.003). A paired sample t-test was carried out, which revealed that needling with rotation showed significant difference from both superficial needling and deep needling. Further, the correlation between the total acupuncture sensation and changes in pressure pain threshold were calculated using Pearson correlation; there was a significant correlation (p = 0.002, p = 0.013). Acupuncture sensation and pressure pain threshold increase according to the depth and rotation of acupuncture. Especially, both display significant increase with needle rotation. Further, there is a significant correlation between acupuncture needling sensation and increase in pressure pain threshold. It seems that needle rotation and acupuncture sensation play an important role in verifying the effect of acupuncture. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fine needle aspiration cytology of cervicofacial actinomycosis

Directory of Open Access Journals (Sweden)

Venkatesh Kusuma

2008-01-01

Full Text Available Actinomycosis is a chronic infection caused by Actinomyces israelii, usually seen in immunocompromised patients or in the background of tissue injury. Cervicofacial actinomycosis presenting as a fixed jaw swelling in an elderly individual can mimic malignancy and pose a diagnostic dilemma. We report here a case of cervicofacial actinomycosis diagnosed by fine needle aspiration, along with a review of the relevant literature. A 60 year-old man presented with a gradually increasing 6 x 5 cm swelling in the left side of his jaw. The swelling was fixed, without any apparent sinus or abscess. Fine needle aspiration was diagnostic as it revealed colonies of actinomyces surrounded by polymorphs and chronic inflammatory cells. The histopathological study of the excised specimen confirmed the cytological findings. Fine needle aspiration is an effective tool in the diagnosis of actinomycosis although its documentation is rare. Difficulties in the management can be avoided by early diagnosis using the fine needle aspiration technique.

CT-guided spinal injection: initial experience with Sprotte tip needles

Energy Technology Data Exchange (ETDEWEB)

Pua, Uei [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore)

2010-09-15

The purpose of this paper is to describe our initial experience and to illustrate the potential benefits of using small caliber (25 and 27 G), noncutting pencil point needles (Sprotte) with single puncture coaxial technique in CT-guided spinal intervention (CTSI). From January 2009 to June 2009, Sprotte needles with single puncture coaxial technique were used in a total of ten patients for selective nerve root block (SNRB), facet joint block, and pars block under CT fluoroscopy (total of 16 target structures). All procedures were performed without conscious sedation, and visual analog scale (VAS) scores were recorded to determine pain related to needle placement. Total CT fluoroscopy time and out-of-plane needle deviation were obtained. Final needle position was documented by contrast injection for SNRBs and image capture for joint space cannulation. Sixteen out of the 16 structures were successfully targeted. No increase in VAS scores associated with needle placement was recorded, after infiltration of local anesthesia. Optimal peri-neurograms were obtained in all cases of SNRB, despite the side-hole opening in the Sprotte needles. Mean CT fluoroscopy time was 2 s (range 2-8 s per structure), and there was no case of out-of-plane needle deviation that required adjustment of the CT gantry. The use of small caliber Sprotte needles in CTSI is technically feasible and represents a potential refinement to current techniques in the management of chronic spinal pain. (orig.)

Evaluation of heat transfer in acupuncture needles: convection and conduction approaches.

Science.gov (United States)

Tzou, Chieh-Han John; Yang, Tzyy-Yih; Chung, Ya-Chien

2015-04-01

Originating in ancient China, acupuncture using needles has been developed for thousands of years and has received attention for its reported medical remedies, such as pain relief and chronic disease treatment. Heat transfer through the needles, which might have effects on the biomechanism of acupuncture, providing a stimulus and regulating homeostasis, has never been studied. This article analyzes the significance of heat transfer through needles via convection and conduction, approached by means of computational analysis. The needle is a cylindrical body, and an axis symmetrical steady-state heat-transfer model that viscosity and static pressure was not applied. This article evaluates heat transfer via acupuncture needles by using five metal materials: silver, copper, brass, iron, and stainless steel. A silver needle of the type extensively applied in acupuncture can dissipate more than seven times as much heat as a stainless steel needle of the same type. Heat transfer through such a needle is significant, compared to natural body-energy consumption over a range of ambient temperatures. The mechanism by which heat flows in or out of the body through the needles may be crucial in the remedial efficacy of acupuncture. Copyright © 2015. Published by Elsevier B.V.

Profiling an electrospray plume by laser-induced fluorescence and Fraunhofer diffraction combined to mass spectrometry: influence of size and composition of droplets on charge-state distributions of electrosprayed proteins.

Science.gov (United States)

Girod, Marion; Dagany, Xavier; Boutou, Véronique; Broyer, Michel; Antoine, Rodolphe; Dugourd, Philippe; Mordehai, Alex; Love, Craig; Werlich, Mark; Fjeldsted, John; Stafford, George

2012-07-14

We investigated how physico-chemical properties of charged droplets are affected by the electrospray process, using simultaneous in situ measurements by laser-induced fluorescence (LIF), Fraunhofer diffraction and mass spectrometry. For this purpose, we implemented a laser-induced-fluorescence profiling setup in conjunction with a fast, high-resolution particle sizing scheme on a modified Agilent Jet Stream electrospray source coupled to a single quadrupole mass analyser. The optical setup permits us to profile the solvent fractionation and the size of the droplets as they evaporate in an electrospray plume by measuring both the angular scattering pattern and emission spectra of a solvatochromic fluorescent dye. Mass spectra are recorded simultaneously. These mass spectrometry and optical spectroscopy investigations allow us to study the relation between the observed charge-state distributions of protein anions and physico-chemical properties of evaporating droplets in the spray plume. By mixing water with methanol, a refolding of cytochrome C is observed as the water percentage increases in the plume due to the preponderant evaporation of volatile methanol.

Return Rates for Needle Exchange Programs: A Common Criticism Answered

Directory of Open Access Journals (Sweden)

Ksobiech Kate

2004-04-01

Full Text Available Abstract This study searched the available needle exchange program (NEP literature for return rate data. A total of 26 articles were found. The overall worldwide return rate was 90%, although this ranged from a low of 15% to a high of 112%. U.S. NEP return rates were gathered from only eight studies, indicating a clear need for more data, although U.S. return rates were comparable to those from NEPs outside of the U.S. One underlying assumption made by opponents of NEPs is that IDUs will not return needles to the distribution site, thereby potentially increasing the risk of health problems to the surrounding community from exposure to contaminated needles. This study's results suggest that NEPs are relatively successful in taking in used needles, although it is generally unclear where the needles were originally acquired, and if IDUs return their own needles, or are returning needles for a social network. Ways for AIDS Service Organizations to capitalize on these brief encounters with IDUs, as well as public policy implications of the findings, are discussed.

In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle

Science.gov (United States)

Li, Yu-Tao; Tang, Li-Na; Ning, Yong; Shu, Qing; Liang, Feng-Xia; Wang, Hua; Zhang, Guo-Jun

2016-06-01

Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip surface, poly(3,4-ethylenedioxythiophene)(PEDOT) was employed as glue water to stick CNT on the needle. The detection limit of the CNT-modified needle was found to be approximately 50 nM and 78 nM in the PBS and the cell medium, respectively. In addition, the needle showed good selectivity to some inflammatory mediators and some electroactive molecules. For the first time, the CNT-modified needle could be directly probed into rat body for real time monitoring of 5-HT in vivo, showing a great potential for better understanding the mechanism of acupuncture treatment.

An ultrasound-driven needle-insertion robot for percutaneous cholecystostomy

International Nuclear Information System (INIS)

Hong, J; Dohi, T; Hashizume, M; Konishi, K; Hata, N

2004-01-01

A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed instrument uses intraoperative images and modifies the needle path in real time by using a novel ultrasonic image segmentation technique. In phantom and volunteer experiments, the needle path updating time was 130 and 301 ms per cycle, respectively. In animal experiments, the needle could be placed accurately in the target

Spruce needles used as radioecological biotracers

International Nuclear Information System (INIS)

Seidel, C.; Gruber, V.; Baumgartner, A.

2009-01-01

In a two years project spruce needle samples of the Austrian Bioindicator Grid were analysed by gamma-ray spectrometry to investigate the spatial and temporal distribution of radionuclides in spruce needles of the last 25 years with the main focus on the radioactive contamination before and after the Chernobyl fallout 1986. More than 600 spruce needle samples at selected locations of the Bioindicator Grid were analysed for different natural and anthropogenic radionuclides: 137 Cs, 40 K, 210 Pb, 226 Ra, 228 Ra, 238 U. Additionally, soil samples were taken at selected sites to study the soil-to-plant transfer. This radioecological evaluation is an important part of an existing environmental surveillance programme in Upper Austria in order to gain basic information on the impact of environmental changes on the radioecological behaviour of spruce trees. (orig.)

A new robotic needle insertion method to minimise attendant prostate motion

International Nuclear Information System (INIS)

Lagerburg, Vera; Moerland, Marinus A.; Vulpen, Marco van; Lagendijk, Jan J.W.

2006-01-01

Background and purpose: The purpose of this study is to investigate the efficacy of a new needle insertion method (tapping instead of pushing) in reducing attendant tissue motion. This can be useful in applications where tissue motion due to needle insertion is problematic such as e.g. MRI-guided prostate brachytherapy and breast biopsies. In this study we will focus on prostate motion due to needle insertion. Material and methods: Prostate motion due to needle insertion was measured in 30 patients, who were transperineally implanted with fiducial gold markers for position verification in prostate intensity modulated radiotherapy. In total 32 needles were manually pushed into the prostate and 29 were tapped with a prototype robotic system. The prostate motion in the cranio-caudal direction was measured on the video record of the ultrasound images. Differences in prostate motion between the two needle insertion methods were analysed making use of SPSS. Results: The mean prostate motion was 5.6 mm (range 0.3-21.6) when the needle was pushed and 0.9 mm (range 0-2.0) when the needle was tapped into the prostate (p < 0.001). Conclusion: Prostate motion was significantly less when the needle was tapped into the prostate compared to when the needle was pushed. This result is important for the development of a tapping, MRI-guided, prostate implant robotic system

Profiling of barrier capacitance and spreading resistance using a transient linearly increasing voltage technique.

Science.gov (United States)

Gaubas, E; Ceponis, T; Kusakovskij, J

2011-08-01

A technique for the combined measurement of barrier capacitance and spreading resistance profiles using a linearly increasing voltage pulse is presented. The technique is based on the measurement and analysis of current transients, due to the barrier and diffusion capacitance, and the spreading resistance, between a needle probe and sample. To control the impact of deep traps in the barrier capacitance, a steady state bias illumination with infrared light was employed. Measurements of the spreading resistance and barrier capacitance profiles using a stepwise positioned probe on cross sectioned silicon pin diodes and pnp structures are presented.

Electrospray synthesis and properties of hierarchically structured PLGA TIPS microspheres for use as controlled release technologies.

Science.gov (United States)

Malik, Salman A; Ng, Wing H; Bowen, James; Tang, Justin; Gomez, Alessandro; Kenyon, Anthony J; Day, Richard M

2016-04-01

Microsphere-based controlled release technologies have been utilized for the long-term delivery of proteins, peptides and antibiotics, although their synthesis poses substantial challenges owing to formulation complexities, lack of scalability, and cost. To address these shortcomings, we used the electrospray process as a reproducible, synthesis technique to manufacture highly porous (>94%) microspheres while maintaining control over particle structure and size. Here we report a successful formulation recipe used to generate spherical poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray (ES) coupled with a novel thermally induced phase separation (TIPS) process with a tailored Liquid Nitrogen (LN2) collection scheme. We show how size, shape and porosity of resulting microspheres can be controlled by judiciously varying electrospray processing parameters and we demonstrate examples in which the particle size (and porosity) affect release kinetics. The effect of electrospray treatment on the particles and their physicochemical properties are characterized by scanning electron microscopy, confocal Raman microscopy, thermogravimetric analysis and mercury intrusion porosimetry. The microspheres manufactured here have successfully demonstrated long-term delivery (i.e. 1week) of an active agent, enabling sustained release of a dye with minimal physical degradation and have verified the potential of scalable electrospray technologies for an innovative TIPS-based microsphere production protocol. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

In-plane ultrasonic needle tracking using a fiber-optic hydrophone

Energy Technology Data Exchange (ETDEWEB)

Xia, Wenfeng, E-mail: wenfeng.xia@ucl.ac.uk; Desjardins, Adrien E. [Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT (United Kingdom); Mari, Jean Martial [Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom and GePaSud, University of French Polynesia, Faa’a 98702, French Polynesia (France); West, Simeon J. [Department of Anaesthesia, University College Hospital, Main Theatres, Maple Bridge Link Corridor, Podium 3, 235 Euston Road, London NW1 2BU (United Kingdom); Ginsberg, Yuval; David, Anna L. [Institute for Women’s Health, University College London, 86-96 Chenies Mews, London WC1E 6HX (United Kingdom); Ourselin, Sebastien [Center for Medical Imaging Computing, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2015-10-15

Purpose: Accurate and efficient guidance of needles to procedural targets is critically important during percutaneous interventional procedures. Ultrasound imaging is widely used for real-time image guidance in a variety of clinical contexts, but with this modality, uncertainties about the location of the needle tip within the image plane lead to significant complications. Whilst several methods have been proposed to improve the visibility of the needle, achieving accuracy and compatibility with current clinical practice is an ongoing challenge. In this paper, the authors present a method for directly visualizing the needle tip using an integrated fiber-optic ultrasound receiver in conjunction with the imaging probe used to acquire B-mode ultrasound images. Methods: Needle visualization and ultrasound imaging were performed with a clinical ultrasound imaging system. A miniature fiber-optic ultrasound hydrophone was integrated into a 20 gauge injection needle tip to receive transmissions from individual transducer elements of the ultrasound imaging probe. The received signals were reconstructed to create an image of the needle tip. Ultrasound B-mode imaging was interleaved with needle tip imaging. A first set of measurements was acquired in water and tissue ex vivo with a wide range of insertion angles (15°–68°) to study the accuracy and sensitivity of the tracking method. A second set was acquired in an in vivo swine model, with needle insertions to the brachial plexus. A third set was acquired in an in vivo ovine model for fetal interventions, with insertions to different locations within the uterine cavity. Two linear ultrasound imaging probes were used: a 14–5 MHz probe for the first and second sets, and a 9–4 MHz probe for the third. Results: During insertions in tissue ex vivo and in vivo, the imaged needle tip had submillimeter axial and lateral dimensions. The signal-to-noise (SNR) of the needle tip was found to depend on the insertion angle. With

Mitigation of Unbalanced Voltage Sags and Voltage Unbalance in CIGRE Low Voltage Distribution Network

DEFF Research Database (Denmark)

Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar

2013-01-01

Any problem with voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM) etc. can be used to mitigate the voltage problems in the distribution system...... to unbalanced faults. The compensation of unbalanced voltage sags and voltage unbalance in the CIGRE distribution network is done by using the four STATCOM compensators already existing in the test grid. The simulations are carried out in DIgSILENT power factory software version 15.0........ The voltage problems dealt with in this paper are to show how to mitigate unbalanced voltage sags and voltage unbalance in the CIGRE Low Voltage (LV) test network and net-works like this. The voltage unbalances, for the tested cases in the CIGRE LV test network are mainly due to single phase loads and due...

[King Injo's disease and burnt needle therapy].

Science.gov (United States)

Kim, In-Sook

2004-12-01

This paper investigates an interrelationship between burnt needle therapy and King Injo's disease. From 1633 (Year 11 in King Injo's reign) to May 5, 1649 (Year 27 in King Injo's reign), right before his death, King Injo was treated with burnt needles by Yi Hyeongik, an acupuncturist when the king had health problems. This study arises from two questions: why was King Injo often treated with burnt needles? and what effect did burnt needles have?Burnt needle therapy is a combined form of acupuncture and moxibustion. Yi Hyeongik was famous for eradicating pathogenic factors. He was appointed as a doctor in the Royal Hospital. The medical definition for pathogenic factors is that they are disease-causing factors. Understanding the pathogenic factor for King Injo's disease could make it possible to find the interrelationship between burnt needles and the king's disease. In the Joseon ear, the prevalent belief about diseases was that diseases could be caused by homeopathic magic. Some people thought homeopathic magic caused King Injo's disease. The actual reasons for King Injo's disease were the participation in the excessive rites of Queen Mother Inmok's funeral and the constant oppression from the Ching Dynasty after disgraceful defeat in the war. When King Injo started to be sick, homeopathic magic cases were found in the royal palace. The king's incurable disease was believed to have happened as a result of homeopathic magic. King Injo's suspicion toward Princess Jeongmyeong derived from her mother, Queen Mother Inmok. Moral justification for King Injo's coup was Gwanghaegun or Prince Gwanghae's immoral conduct toward Queen Mothe Inmok. After he was installed, King Injo obeyed the Queen Mother and showed her every attention. Meanwhile, he treated Princess Jeongmyeong with respect, maximized the moral justification for the coup, and solidified the royal authority. However, constant rebellions and treasons threatened King Injo. The king suspected that Queen Mother

Fine Needle Aspiration Biopsy in a Rural Family Practice

African Journals Online (AJOL)

ultrasound scan. A 21-gauge 1½-inch or 23-gauge 1¼-inch needle, attached to a 10-mL disposable plastic syringe, was used for FNAB of superficial masses. For percutaneous FNAB of deep-seated organs and masses, a 23 gauge 1¼-inch needle or 3½-inch spinal needle was used. The aspirate was spread on slides and ...

Sonographically guided fine-needle biopsy of thyroid nodules: the effects of nodule characteristics, sampling technique, and needle size on the adequacy of cytological material

International Nuclear Information System (INIS)

Degirmenci, B.; Haktanir, A.; Albayrak, R.; Acar, M.; Sahin, D.A.; Sahin, O.; Yucel, A.; Caliskan, G.

2007-01-01

Aim: To evaluate the effects of sonographic characteristics of thyroid nodules, the diameter of needle used for sampling, and sampling technique on obtaining sufficient cytological material (SCM). Materials and methods: We performed sonography-guided fine-needle biopsy (FNB) in 232 solid thyroid nodules. Size-, echogenicity, vascularity, and localization of all nodules were evaluated by Doppler sonography before the biopsy. Needles of size 20, 22, and 24 G were used for biopsy. The biopsy specimen was acquired using two different methods after localisation. In first method, the needle tip was advanced into the nodule in various positions using a to-and-fro motion whilst in the nodule, along with concurrent aspiration. In the second method, the needle was advanced vigorously using a to-and-fro motion within the nodule whilst being rotated on its axis (capillary-action technique). Results: The mean nodule size was 2.1 ± 1.3 cm (range 0.4-7.2 cm). SCM was acquired from 154 (66.4%) nodules by sonography-guided FNB. In 78 (33.6%) nodules, SCM could not be collected. There was no significant difference between nodules with different echogenicity and vascularity for SCM. Regarding the needle size, the lowest rate of SCM was obtained using 20 G needles (56.6%) and the highest rate of adequate material was obtained using 24 G needles (82.5%; p = 0.001). The SCM rate was 76.9% with the capillary-action technique versus 49.4% with the aspiration technique (p < 0.001). Conclusion: Selecting finer needles (24-25 G) for sonography-guided FNB of thyroid nodules and using the capillary-action technique decreased the rate of inadequate material in cytological examination

[Research progress of needles with knife-edge for carotid cardiac syndrome].

Science.gov (United States)

Tan, Lingqiong; Zhao, Yanling

2015-04-01

According to topographic anatomy, pathogenesis and by retrieving, summarizing and analyzing literature regarding needle-knife and needles with knife-edge for carotid cardiac syndrome, it is found out that clinical misdiagnosis rate of carotid cardiac syndrome is considerably high. Needle-knife and needles with knife-edge could significantly improve the clinical symptoms of carotid cardiac syndrome, showing characteristic and advantage in treatment, but it is deficient in technique standard and efficacy criteria that should be united and authoritative. Researches regarding pathogenesis of carotid cardiac syndrome are not systematic. Clinical observation regarding long-term efficacy and relapse of needle-knife and needles with knife-edge treatment is rare. It is believed that the awareness on carotid cardiac syndrome should be increased to reduce misdiagnosis; scientific and standardized technique standard and efficacy criteria should be established; systematic and comprehensive researches regarding mechanism of needle-knife and needles with knife-edge for carotid cardiac syndrome should be launched; besides, clinical discussion regarding its long-term efficacy should start to provide a better clinical guideline.

Classification of terverticillate Penicillia by electrospray mass spectrometric profiling

DEFF Research Database (Denmark)

Smedsgaard, Jørn; Hansen, Michael Edberg; Frisvad, Jens Christian

2004-01-01

429 isolates of 58 species belonging to Penicillium subgenus Penicillium are classified from direct infusion electrospray mass spectrometry (diMS) analysis of crude extracts by automated data processing. The study shows that about 70% of the species can be classified correctly into species using...

Improving needle tip identification during ultrasound-guided procedures in anaesthetic practice.

Science.gov (United States)

Scholten, H J; Pourtaherian, A; Mihajlovic, N; Korsten, H H M; A Bouwman, R

2017-07-01

Ultrasound guidance is becoming standard practice for needle-based interventions in anaesthetic practice, such as vascular access and peripheral nerve blocks. However, difficulties in aligning the needle and the transducer can lead to incorrect identification of the needle tip, possibly damaging structures not visible on the ultrasound screen. Additional techniques specifically developed to aid alignment of needle and probe or identification of the needle tip are now available. In this scoping review, advantages and limitations of the following categories of those solutions are presented: needle guides; alterations to needle or needle tip; three- and four-dimensional ultrasound; magnetism, electromagnetic or GPS systems; optical tracking; augmented (virtual) reality; robotic assistance; and automated (computerised) needle detection. Most evidence originates from phantom studies, case reports and series, with few randomised clinical trials. Improved first-pass success and reduced performance time are the most frequently cited benefits, whereas the need for additional and often expensive hardware is the greatest limitation to widespread adoption. Novice ultrasound users seem to benefit most and great potential lies in education. Future research should focus on reporting relevant clinical parameters to learn which technique will benefit patients most in terms of success and safety. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

Risk of needle stick injuries in health care workers: bad habits (recapping needles) last long.

Science.gov (United States)

Rogowska-Szadkowska, Dorota; Stanisławowicz, Małgorzata; Chlabicz, Sławomir

2010-01-01

In order to assess the nurses' knowledge concerning the risk of hepatitis B and C viruses or human immunodeficiency virus infection while performing their professional duties, an anonymous questionnaire developed by the authors was distributed in 2008. Surprisingly 64% respondents occasionally recapping needles after injections, although they know the procedures which are obligatory at the ward. The first step in preventing percutaneous injuries should focus on efforts to eliminate the practice of recapping needles, though education and convenient placement of puncture-resistant containers for the disposal of used sharps.

Study of light transmission through gauze pad effected by blood or liquids to detect needle dislodgement.

Science.gov (United States)

Takeuchi, Akihiro; Ishida, Kai; Morohoshi, Yasuo; Shinbo, Toshihiro; Hirose, Minoru; Ikeda, Noriaki

2010-02-01

Serious accidents during hemodialysis such as a large amount of blood loss are often caused by venous needle dislodgement. To develop a bleeding sensor based on a photo sensor for monitoring the needle sites, we studied effects of liquids and porcine blood on light transmission through a thin gauze pad with a basic photo sensor. The photo sensor consisted of an ordinary electrical circuit, a light emitting diode (LED, lambda max = 645 nm), a photo diode (PD), and a thin gauze pad placed between the LED and PD that were tightly attached to the edges of a plastic clip. The light transmitted through the gauze pad, soaked with liquids or porcine blood dropped on it, was measured with a digital voltmeter. The liquids were reverse osmosis water, physiological saline, glucose in water at 5, 10, 20, 40 and 50%, porcine plasma, and porcine blood (Hct 40, 30 and 20%). The liquids on a tight-weave gauze pad, significantly increased the voltage (light transmission) from 0.412 +/- 0.003 V (SD) to 0.794 +/- 0.025 V (minimum, by reverse osmosis water) and to 0.945 +/- 0.011 V (maximum, by 50% glucose). The porcine blood significantly decreased the voltage from 0.412 to 0.195 +/- 0.030 V in Hct 40%, to 0.334 +/- 0.035 in Hct 30%, to 0.397 +/- 0.007 V in Hct 20%. The higher the concentration of glucose, the more the light transmission increased. The higher concentration of Hct, the more the light transmission decreased. Similar results were also shown for the loose-weave pad. Using two types of gauze pads, we confirmed that liquids significantly increased light transmission through gauze pad, but porcine blood decreased light transmission. This opposite response can be used to distinguish liquids from blood on a gauze pad.

Simulation-based design of a microfabricated pneumatic electrospray nebulizer

Czech Academy of Sciences Publication Activity Database

Járvás, G.; Grym, Jakub; Foret, František; Guttman, A.

2015-01-01

Roč. 36, č. 3 (2015), s. 386-392 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : CFD * microfabrication * modeling * electrospray * nebulizer Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.482, year: 2015

Simulation-based design of a microfabricated pneumatic electrospray nebulizer

Czech Academy of Sciences Publication Activity Database

Járvás, G.; Grym, Jakub; Foret, František; Guttman, A.

2015-01-01

Roč. 36, č. 3 (2015), s. 386-392 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : CFD * microfabrication * modeling * electrospray * nebulizer Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.482, year: 2015

[Special penetration needling for refractory peripheral facial paralysis].

Science.gov (United States)

Cao, Rongjuan; Qiu, Xiaohu; Xie, Xiaokun

2018-03-12

To observe the clinical effect difference between special penetration needling and conventional penetration needling for the refractory peripheral facial paralysis. A total of 97 patients with intractable facial paralysis were randomized into an observation group (49 cases and 2 dropping) and a control group (48 cases and 4 dropping). In the observation group, special penetration needling at an angle about 45° between the penetration needle and paralysis muscle bundle was used, Yangbai (GB 14) through Touwei (ST 8), Yangbai (GB 14) through Shangxing (GV 23), Sizhukong (TE 23) through Yuyao (EX-HN 4), Qianzhen (Extra) through Yingxiang (LI 20), mutual penetration between Yingxiang (LI 20) and Jiache (ST 6). Conventional penetration needling was applied in the control group, Yangbai (GB 14) through Yuyao (EX-HN 4), Cuanzhu (BL 2) through Yuyao (EX-HN 4), mutual penetration between Dicang (ST 4) and Jiache (ST 6), Qianzheng (Extra) through Dicang (ST 4), Sibai (ST 2) through Yingxiang (LI 20). Three groups of electroacupuncture (discontinuous wave, 1 Hz) with tolerance were connected respectively in the two groups, Yangbai (GB 14) and Sizhukong (TE 23), Yangbai (GB 14) and Qianzheng (Extra), Yingxiang (LI 20) and Jiache (ST 6) in the observation group, Yangbai (GB 14) and Cuanzhu (BL 2), Dicang (ST 4) and Jiache (ST 6), Qianzheng (Extra) and Sibai (ST 2) in the control group. TDP was applied in the two groups at the affected Yifeng (TE 17), Jiache (ST 6) and Qianzheng (Extra), which were around the ear. Perpendicular insertion was used at Yifeng (TE 17) at the affected side and Hegu (LI 4) at the healthy side and bilateral Zusanli (ST 36). The needles were retained for 30 min. The treatment was given for 3 courses, once a day and 10 days as a course, 5 days at the interval. House-Brackmann (H-B) facial nerve grading score was recorded before and after treatment. The clinical effects were compared. The H-B scores after treatment in the two groups were higher than

Detection of chlorinated and brominated byproducts of drinking water disinfection using electrospray ionization-high-field asymmetric waveform ion mobility spectrometry-mass spectrometry.

Science.gov (United States)

Ells, B; Barnett, D A; Froese, K; Purves, R W; Hrudey, S; Guevremont, R

1999-10-15

The lower limit of detection for low molecular weight polar and ionic analytes using electrospray ionization-mass spectrometry (ESI-MS) is often severely compromised by an intense background that obscures ions of trace components in solution. Recently, a new technique, referred to as high-field asymmetric waveform ion mobility spectrometry (FAIMS), has been shown to separate gas-phase ions at atmospheric pressure and room temperature. A FAIMS instrument is an ion filter that may be tuned, by control of electrical voltages, to continuously transmit selected ions from a complex mixture. This capability offers significant advantages when FAIMS is coupled with ESI, a source that generates a wide variety of ions, including solvent clusters and salt adducts. In this report, the tandem arrangement of ESI-FAIMS-MS is used for the analysis of haloacetic acids, a class of disinfection byproducts regulated by the US EPA. FAIMS is shown to effectively discriminate against background ions resulting from the electrospray of tap water solutions containing the haloacetic acids. Consequently, mass spectra are simplified, the selectivity of the method is improved, and the limits of detection are lowered compared with conventional ESI-MS. The detection limits of ESI-FAIMS-MS for six haloacetic acids ranged between 0.5 and 4 ng/mL in 9:1 methanol/tap water (5 and 40 ng/mL in the original tap water samples) with no preconcentration, derivatization, or chromatographic separation prior to analysis.

Optimal needle placement for the accurate magnetic material quantification based on uncertainty analysis in the inverse approach

International Nuclear Information System (INIS)

Abdallh, A; Crevecoeur, G; Dupré, L

2010-01-01

The measured voltage signals picked up by the needle probe method can be interpreted by a numerical method so as to identify the magnetic material properties of the magnetic circuit of an electromagnetic device. However, when solving this electromagnetic inverse problem, the uncertainties in the numerical method give rise to recovery errors since the calculated needle signals in the forward problem are sensitive to these uncertainties. This paper proposes a stochastic Cramér–Rao bound method for determining the optimal sensor placement in the experimental setup. The numerical method is computationally time efficient where the geometrical parameters need to be provided. We apply the method for the non-destructive magnetic material characterization of an EI inductor where we ascertain the optimal experiment design. This design corresponds to the highest possible resolution that can be obtained when solving the inverse problem. Moreover, the presented results are validated by comparison with the exact material characteristics. The results show that the proposed methodology is independent of the values of the material parameter so that it can be applied before solving the inverse problem, i.e. as a priori estimation stage

Drug-related deaths and the sales of needles through pharmacies.

Science.gov (United States)

Davidson, Peter J; Martinez, Alexis; Lutnick, Alexandra; Kral, Alex H; Bluthenthal, Ricky N

2015-02-01

Providing needles to people who inject drugs is a well-proven public health response to the transmission of HIV and other blood borne viruses. Despite over a quarter of a century of research, new concerns about potential unintended negative consequences of needle distribution continue to emerge. Specifically, a claim was recently made that the introduction of pharmacy sales of needles was followed by an increase in overdoses in pharmacy parking lots. If true, this would have serious implications for the design of needle access programs, particularly those involving pharmacy sales of needles. We examine spatial relationships between drug-related deaths and pharmacies in Los Angeles County (population 9.8 million) before and after the 2007 enactment of a California law allowing pharmacy sales of needles without a prescription. Seven thousand and forty-nine drugs related deaths occurred in Los Angeles county from 2000 to 2009 inclusive. Four thousand two hundred and seventy-five of these deaths could be geocoded, and were found to be clustered at the census tract level. We used three methods to examine spatial relationships between overdose death locations and pharmacy locations for two years on either side of the enactment of the pharmacy sales law, and found no statistically significant changes. Among the 711 geocodable deaths occurring in the two years following the change in law, no death was found to occur within 50m of a pharmacy which sold needles. These results are consistent with prior studies which suggest pharmacy sales of needles improve access to needles without causing increased harms to the surrounding community. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The development of high-voltage repetitive low-jitter corona stabilized triggered switch

Science.gov (United States)

Geng, Jiuyuan; Yang, Jianhua; Cheng, Xinbing; Yang, Xiao; Chen, Rong

2018-04-01

The high-power switch plays an important part in a pulse power system. With the trend of pulse power technology toward modularization, miniaturization, and accuracy control, higher requirements on electrical trigger and jitter of the switch have been put forward. A high-power low-jitter corona-stabilized triggered switch (CSTS) is designed in this paper. This kind of CSTS is based on corona stabilized mechanism, and it can be used as a main switch of an intense electron-beam accelerator (IEBA). Its main feature was the use of an annular trigger electrode instead of a traditional needle-like trigger electrode, taking main and side trigger rings to fix the discharging channels and using SF6/N2 gas mixture as its operation gas. In this paper, the strength of the local field enhancement was changed by a trigger electrode protrusion length Dp. The differences of self-breakdown voltage and its stability, delay time jitter, trigger requirements, and operation range of the switch were compared. Then the effect of different SF6/N2 mixture ratio on switch performance was explored. The experimental results show that when the SF6 is 15% with the pressure of 0.2 MPa, the hold-off voltage of the switch is 551 kV, the operating range is 46.4%-93.5% of the self-breakdown voltage, the jitter is 0.57 ns, and the minimum trigger voltage requirement is 55.8% of the peak. At present, the CSTS has been successfully applied to an IEBA for long time operation.

Root canal debris removal using different irrigating needles: An SEM study

Directory of Open Access Journals (Sweden)

Sheetal Ghivari

2011-01-01

Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by

Fundamentals of Biomolecule Analysis by Electrospray Ionization Mass Spectrometry

Science.gov (United States)

Weinecke, Andrea; Ryzhov, Victor

2005-01-01

Electrospray ionization (ESI) is a soft ionization technique that allows transfer of fragile biomolecules directly from solution into the gas phase. An instrumental analysis laboratory experiment is designed that would introduce the students to the ESI technique, major parameters of the ion trap mass spectrometers and some caveats in…

Interactions of nucleobases with alkali earth metal cations--electrospray ionization mass spectrometric study.

Science.gov (United States)

Frańska, Magdalena

2007-01-01

Interactions of nucleobases with alkali earth metal cations have been studied by electrospray ionization mass spectrometry (ESI-MS). Nucleobases containing at least one oxygen atom form stable complexes with alkali earth metal cations. This phenomenon can be explained on the grounds of the well known theory of hard and soft acids and bases. Uracil and thymine make complexes only when in their deprotonoted forms. The cations of great radii (Sr(2+), Ba(2+)) are more prone to form complexes of stoichiometry 1:1 with uracil and thymine than the cations of small radii (Mg(2+), Ca(2+)). On the other hand, Mg(2+) forms complexes of stoichiometry 2:1 and 3:2 with uracil and thymine. Gas-phase stabilities of the 1:1 complexes are higher for the cations of small radii, in contrast to the solution stabilities. For cytosine and 9- methylhypoxantine the 1:1 complexes of their deprotonated forms are observed at higher cone voltage as a result of HCl molecule loss from the complexes containing the counter ion (Cl(-)). In solution, more stable complexes are formed with metal cations of low radii. Gas-phase stability of the complexes formed by deprotonated 9- methyl-hypoxantine increases with increasing metal cation radius.

A climate response function explaining most of the variation in the forest floor needle mass and the needle decomposition in pine forests across Europe

DEFF Research Database (Denmark)

Kurz-Besson, C.; Coûteaux, M.M.; Berg, Bjørn

2006-01-01

The forest floor needle mass and the decomposition rates of pine needle litter in a European climate transect were studied in order to estimate the impact of climate change on forest soil carbon sequestration. Eight pine forests preserved from fire were selected along a climatic latitudinal...... gradient from 40° to 60° N, from Spain and Portugal to Sweden. The forest floor (Oi and Oe layers) was sorted into five categories of increasing decomposition level according to morphological criteria. The needle mass loss in each category was determined using a linear mass density method. The needle...... and a recalcitrant one. NF was correlated with actual evapotranspiration (AET) whereas the decomposition parameters (decomposition rate of the decomposable fraction, first year mass loss, forest floor needle mass, age of the most-decomposed category) were related to a combined response function to climate (CRF...

[Meta-analysis of needle-knife treatment on cervical spondylosis].

Science.gov (United States)

Kan, Li-Li; Wang, Hai-Dong; Liu, An-Guo

2013-11-01

To assess the efficacy of cervical spondylosis by needle-knife treatment according to the correlated literature of RCT,to compare advantages of needle-knife treatment. Randomized Controlled Trials about needle-knife treatment of cervical spondylosis were indexed from Chinese HowNet (CNKI) and Wanfang (WF) from 2000 to 2012, then were analyzed the efficacy by Review Manager 5.1 software. A total of 13 RCT literatures and 1 419 patients were included. The methods of included studies were poor in quality evaluation because of large sample and multi-center RCT studies was lacked, randomization method was not accurate enough, diagnostic criteria and efficacy evaluation were various, only four studies described long-term efficacy, most of the literature didn't describe the adverse event and fall off,all studies did not use the blind method. The Meta analysis outcome showed overall efficiency of needle-knife therapy was better than acupuncture and traction. Needle-knife therapy compared with Acupuncture, the total RR = 0.19, 95% confidence interval was (0.15, 0.24), P knife therapy is higher;compared with traction therapy, although,needle-knife therapy has a high overall effectiveness, but because of the loss of total sample size, the outcome RCT researches to confirm.

Dry needling in lateral epicondylitis: a prospective controlled study.

Science.gov (United States)

Uygur, Esat; Aktaş, Birol; Özkut, Afşar; Erinç, Samet; Yilmazoglu, Emime Gül

2017-11-01

Lateral epicondylitis (LE), a common disease, especially in middle age, causes decreased productivity and economic losses. The first-line treatment for LE is conservative and consists of topical and oral anti-inflammatory drugs, ice application, and brace use. If the first-line treatment fails, second-line treatment modalities, which are generally invasive, are offered. Second-line therapeutic regimens include saline, corticosteroid, or platelet-rich plasma injections. Dry needling is relatively new. We hypothesized that dry needling would be at least as effective as first-line treatment for LE. We compared the outcomes of first-line treatment and dry needling. The study allocated 110 patients into groups using online randomization software. After completing the Patient-rated Tennis Elbow Evaluation (PRTEE), patients in group I received dry needling, whereas those in group II received first-line treatment, consisting of ibuprofen 100 mg twice a day and a proximal forearm brace. The patients were evaluated after three weeks and six months. The study ultimately analyzed 92 patients. Although both treatment methods were effective at three weeks, dry needling was significantly more effective than the first-line treatment at six months. Because of the low complication rate, dry needling is a safe method, and it might be an effective treatment option for LE.

King Injo's Disease and Burnt Needle Therapy

Directory of Open Access Journals (Sweden)

KIM In-Sook

2004-12-01

Full Text Available This paper investigates an interrelationship between burnt needle therapy(번침 and King Injo'sdisease. From 1633 (Year 11 in King Injo's reign to May 5, 1649 (Year 27 King in Injo's reign, right before his death, King Injo(인조 was treated with burnt needles by Yi Hyeongik(이형익, an acupuncturist when the king had health problems. This study arises from two questions: why was King Injo often treated with burnt needles? and what effect did burnt needles have? Burnt needle therapy is a combined form of acupuncture and moxibustion. Yi Hyeongik was famous for eradicating pathogenic factors. He was appointed as a doctor in the Royal Hospital. The medical definition for pathogenic factors is that they are disease-causing factors. Understanding the pathogenic factor for King Injo's disease could make it possible to find the interrelationship between burnt needles and the king's disease. In the Joseon era, the prevalent belief about diseases was that diseases could be caused by homeopathic magic. Some people thought homeopathic magic caused King Injo's disease.　 The actual reasons for King Injo's disease were the participation in the excessive rites of Queen Mother Inmok's funeral and the constant oppression from the Ching Dynasty after disgraceful defeat in the war. When King Injo started to be sick, homeopathic magic cases were found in the royal palace. The king's incurable disease was believed to have happened as a result of homeopathic magic. King Injo's suspicion toward Princess Jeongmyeong(정명공주 derived from her mother, Queen Mother Inmok(인목대비. Moral justification for King Injo's coup was Gwanghaegun(광해군 or Prince Gwanghae's immoral conduct toward Queen Mother Inmok. After he was installed, King Injo obeyed the Queen Mother and showed her every attention. Meanwhile, he treated Princess Jeongmyeong with respect, maximized the moral justification for the coup, and solidified the royal authority. However, constant

Are needle-free injections a useful alternative for growth hormone therapy in children? Safety and pharmacokinetics of growth hormone delivered by a new needle-free injection device compared to a fine gauge needle.

NARCIS (Netherlands)

Dorr, H.G.; Zabransky, S.; Keller, E.; Otten, B.J.; Partsch, C.J.; Nyman, L.; Gillespie, B.K.; Lester, N.R.; Wilson, A.M.; Hyren, C.; Kuijck, M.A. van; Schuld, P.; Schoenfeld, S.L.

2003-01-01

The clinical safety, use and pharmacokinetics of a new needle-free device for delivery of growth hormone (GH) were compared with those of conventional needle injection devices. In an open-label, randomized, 4-period crossover study, 18 healthy adults received single subcutaneous injections of

Fine-needle versus core-needle biopsy – which one to choose in preoperative assessment of focal lesions in the breasts? Literature review

Directory of Open Access Journals (Sweden)

Ewa Łukasiewicz

2017-12-01

Full Text Available Aim: The aim of the study was to review two techniques that can be used to verify focal lesions in the breasts: fine-needle aspiration biopsy and core-needle biopsy. Material and methods: Fifty-five articles (original papers and reviews, half of them published within the past 5 years, were included in the analysis. The authors also took their own experience into account. Results: Pre-operative assessment of focal lesions in the breasts is crucial in the planning of further therapeutic management. The role of fine-needle aspiration biopsy has been reduced lately due to its low sensitivity and specificity as well as a high rate of non-diagnostic, suspicious and false negative results. This method does not enable one to differentiate between in situ and invasive disease. Currently, fine-needle biopsy is recommended for cystic lesions, suspected of being recurrences in the chest wall, and lymph node metastases. Core-needle biopsy is the basic diagnostic method of breast lesions. According to the recommendations of the Polish Ultrasound Society and American College of Radiology, BIRADS 4 and 5 lesions should be evaluated histopathologically. Core-needle biopsy makes it possible to establish a final diagnosis more frequently than fine-needle biopsy, both in the case of benign and malignant lesions. It delivers more information about the nature of a tumor (mutation of HER-2, estrogen and progesterone receptors and Ki-67 index. Its limitations include: underestimation of invasion and failure to recognize the components of ductal carcinoma in situ in papillary and atypical lesions. Single fine-needle aspiration biopsy is inexpensive, but when considering the cost of further diagnosis due to non-diagnostic, suspicious and atypical results, this method generates high additional costs. Conclusions: Microscopic verification of focal breast lesions is crucial for further therapeutic decisions. It has been proven that histopathological verification is more

Modified microdissection electrocautery needle

OpenAIRE

Singh, Virendra; Kumar, Pramod

2014-01-01

Electrocautery is routinely used in surgical procedures. The commercially available microdissection electrocautery needles are costly. To overcome this disadvantage, we have modified monopolar electrocautery tip to function as well as commercially available systems.

Measurement of tritium in tissue free water of pine needles

International Nuclear Information System (INIS)

Zheng Xiaomin; Wu Zongmei

1993-01-01

Tissue Free Water (TFW) of pine needles is separated out through azeotropic distillation of pine needles and toluene. Recovery ratio of TFW is 90%. Tritium activity in the needles is 1.8 Bq/L(H 2 O), which is of the same level with tritiated water vapour (HTO) in atmosphere during the corresponding period

Comparison of Histologic Core Portions Acquired from a Core Biopsy Needle and a Conventional Needle in Solid Mass Lesions: A Prospective Randomized Trial.

Science.gov (United States)

Lee, Ban Seok; Cho, Chang-Min; Jung, Min Kyu; Jang, Jung Sik; Bae, Han Ik

2017-07-15

The superiority of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) over EUS-guided fine needle aspiration (EUS-FNA) remains controversial. Given the lack of studies analyzing histologic specimens acquired from EUS-FNB or EUS-FNA, we compared the proportion of the histologic core obtained from both techniques. A total of 58 consecutive patients with solid mass lesions were enrolled and randomly assigned to the EUS-FNA or EUS-FNB groups. The opposite needle was used after the failure of core tissue acquisition using the initial needle with up to three passes. Using computerized analyses of the scanned histologic slide, the overall area and the area of the histologic core portion in specimens obtained by the two techniques were compared. No significant differences were identified between the two groups with respect to demographic and clinical characteristics. Fewer needle passes were required to obtain core specimens in the FNB group (pcore (11.8%±19.5% vs 8.0%±11.1%, p=0.376) or in the diagnostic accuracy (80.6% vs 81.5%, p=0.935) between two groups. The proportion of histologic core and the diagnostic accuracy were comparable between the FNB and FNA groups. However, fewer needle passes were required to establish an accurate diagnosis in EUS-FNB.

Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

International Nuclear Information System (INIS)

Thompson, S.A.; Fung, A.Y.C.; Zaider, M.

2002-01-01

One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. (author)

Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

Energy Technology Data Exchange (ETDEWEB)

Thompson, S.A. [Department of Medical Physics, North Shore-Long Island Jewish Health System, Manhassett, NY (United States); Fung, A.Y.C.; Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2002-08-21

One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. (author)

Temporal and spatial evolution of EHD particle flow onset in air in a needle-to-plate negative DC corona discharge

International Nuclear Information System (INIS)

Mizeraczyk, J; Berendt, A; Podlinski, J

2016-01-01

In this paper we present images showing the temporal and spatial evolution of the electrohydrodynamic (EHD) flow of dust particles (cigarette smoke) suspended in still air in a needle-to-plate negative DC corona discharge arrangement just after the corona onset, i.e. in the first stage of development of the EHD particle flow. The experimental apparatus for our study of the EHD flow onset consisted of a needle-to-plate electrode arrangement, high voltage power supply and time-resolved EHD imaging system based on 2D time-resolved particle image velocimetry equipment. The time-resolved flow images clearly show the formation of a ball-like flow structure at the needle tip just after the corona discharge onset, and its evolution into a mushroom-like object moving to the collecting electrode. After a certain time, when the mushroom-like object is still present in the interelectrode gap a second mushroom-like object forms near the needle electrode and starts to move towards the collecting electrode. Before the first mushroom-like object reaches the collecting electrode several similar mushroom-like objects can be formed and presented simultaneously in the interelectrode gap. They look like a series of mushroom-like minijets shot from the needle electrode vicinity towards the collecting electrode. The simultaneous presence of mushroom-like minijets in the interelectrode gap in the corona discharge in particle-seeded air resembles the negative-ion-charged ‘clouds’ (induced by the Trichel pulses) traversing simultaneously the interelectrode gap of the corona discharge in air, predicted a long time ago by Loeb, and Lama and Gallo and recently by Dordizadeh et al . Analysing the time behaviours of the mushroom-like minijets and current waveform in the corona discharge in particle-seeded air, we found that the Trichel pulse trains, formed just after the corona onset initiates the mushroom-like minijets. The first stage of development of the EHD particle flow, the area of

The Hydrodynamics of Needle-Free Intradermal Jet Injection

Science.gov (United States)

Simmons, Jonathan; Marston, Jeremy; Fisher, Paul; Broderick, Kate

2017-11-01

Needle-free methods of drug delivery circumvent the drawbacks associated with the use of hypodermic needles such as needle-stick injuries, needle-phobia, cross contamination and disposal. Furthermore, pioneering DNA-based vaccines that aim to treat cancer and fight infectious diseases, such as HIV, Ebola and Zika, require precise deposition into the skin to target the immune response producing cells found only in the epidermis and dermis. Intradermal (ID) delivery can be achieved using a needle and the Mantoux technique but this requires a highly skilled technician and so extensive use of DNA vaccines calls for an alternative method of delivery. One option is jet injection which has been employed in mass vaccination programs for intramuscular or subcutaneous delivery and is used by some diabetic patients to inject insulin. In this talk I will present results from our ongoing ex-vivo experimental study into ID jet injection. Ultra-high-speed imaging is used to visualize the process of the jet exiting the nozzle and striking excised skin. A skin bleb grows as liquid is deposited within the skin. I will discuss how the control parameters, such as the rheological profile of the liquid and the stand-off distance, influence the volume of liquid successfully delivered intradermally.

Influences of porous reservoir Laplace pressure on emissions from passively fed ionic liquid electrospray sources

Energy Technology Data Exchange (ETDEWEB)

Courtney, Daniel G., E-mail: dcourtney@alum.mit.edu; Shea, Herbert [Ecole Polytechnique Federale de Lausanne (EPFL), Microsystems for Space Technologies Laboratory (LMTS), Neuchatel CH-2002 (Switzerland)

2015-09-07

Passively fed ionic liquid electrospray sources are capable of efficiently emitting a variety of ion beams with promising applications to spacecraft propulsion and as focused ion beams. Practical devices will require integrated or coupled ionic liquid reservoirs; the effects of which have not been explored in detail. Porous reservoirs are a simple, scalable solution. However, we have shown that their pore size can dramatically alter the beam composition. Emitting the ionic liquid 1-ethyl-3-methylimidazolium bis(triflouromethylsulfonyl)amide, the same device was shown to yield either an ion or droplet dominated beam when using reservoirs of small or large pore size, respectively; with the latter having a mass flow in excess of 15 times larger than the former at negative polarity. Another source, emitting nearly purely ionic beams of 1-ethyl-3-methylimidazolium tetrafluoroborate, was similarly shown to emit a significant droplet population when coupled to reservoirs of large (>100 μm) pores; constituting a reduction in propulsive efficiency from greater than 70% to less than 30%. Furthermore, we show that reservoir selection can alter the voltage required to obtain and sustain emission, increasing with smaller pore size.

Developing a Vacuum Electrospray Source To Implement Efficient Atmospheric Sampling for Miniature Ion Trap Mass Spectrometer.

Science.gov (United States)

Yu, Quan; Zhang, Qian; Lu, Xinqiong; Qian, Xiang; Ni, Kai; Wang, Xiaohao

2017-12-05

The performance of a miniature mass spectrometer in atmospheric analysis is closely related to the design of its sampling system. In this study, a simplified vacuum electrospray ionization (VESI) source was developed based on a combination of several techniques, including the discontinuous atmospheric pressure interface, direct capillary sampling, and pneumatic-assisted electrospray. Pulsed air was used as a vital factor to facilitate the operation of electrospray ionization in the vacuum chamber. This VESI device can be used as an efficient atmospheric sampling interface when coupled with a miniature rectilinear ion trap (RIT) mass spectrometer. The developed VESI-RIT instrument enables regular ESI analysis of liquid, and its qualitative and quantitative capabilities have been characterized by using various solution samples. A limit of detection of 8 ppb could be attained for arginine in a methanol solution. In addition, extractive electrospray ionization of organic compounds can be implemented by using the same VESI device, as long as the gas analytes are injected with the pulsed auxiliary air. This methodology can extend the use of the proposed VESI technique to rapid and online analysis of gaseous and volatile samples.

Improving needle tip identification during ultrasound-guided procedures in anaesthetic practice

NARCIS (Netherlands)

Scholten, H.J.; Pourtaherian, A.; Mihajlovic, N.; Korsten, H.; Bouwman, R.A.

2017-01-01

Ultrasound guidance is becoming standard practice for needle-based interventions in anaesthetic practice, such as vascular access and peripheral nerve blocks. However, difficulties in aligning the needle and the transducer can lead to incorrect identification of the needle tip, possibly damaging

Single-incision laparoscopic cholecystectomy with needle graspers.

Science.gov (United States)

Sumiyoshi, Kinjiro; Sato, Norihiro; Akagawa, Shin; Hirano, Tatsuya; Koikawa, Kazuhiro; Horioka, Kohei; Ozono, Keigo; Fujiwara, Kenji; Tanaka, Masao; Sada, Masayuki

2012-01-01

Single-incision laparoscopic cholecystectomy (SILC) is a promising alternative to standard multi-incision laparoscopic cholecystectomy (LC). However, generalization of SILC is still hampered by technical difficulties mainly associated with the lack of trocars used for retraction of the gallbladder. We therefore developed a modified method of SILC with the use of needle graspers (SILC-N) for optimal retraction and exposure. In addition to two trocars inserted through a single transumbilical incision, two needle ports were placed on the right subcostal and lateral abdominal wall, through which needle graspers were used for retraction of the gallbladder. Since December, 2009, 12 patients with symptomatic cholelithiasis were treated by SILC-N. SILC-N was successfully performed in all but one patient requiring a conversion to the 4-port LC with a mean operative time of 71.5 (48-107) minutes. None of the patients experienced intraoperative or postoperative complications. The transumbilical incision and pinholes for needle graspers were almost invisible on discharge. Our preliminary results suggest that SILC-N is a simple, safe and feasible technique of cholecystectomy offering similar postoperative recovery and better cosmetic outcome as compared to conventional LC.

Needle-shaped and platelet growth of borax crystals

International Nuclear Information System (INIS)

Takoo, R.K.; Patel, B.R.; Joshi, M.S.

1983-01-01

Needle-shaped and platelet growth of borax crystals from solutions is reported. Results of microtopographical studies on both the varieties are discussed. It is suggested that a slow rate of evaporation favours needle growth and a faster rate is conducive to the growth of platelets. (author)

Discordance Rate between Thyroid Fine Needle Aspiration Cytology ...

African Journals Online (AJOL)

Discordance Rate between Thyroid Fine Needle Aspiration Cytology and Histopathologic Diagnosis. Wondwossen Ergete, Daniel Abebe. Abstract. Fine Needle Aspiration (FNA) of the thyroid is a low cost procedure, which can give an accurate diagnosis promptly. The objective of this study was to assess the diagnostic ...

Biopsy Needle Localization and Tracking Using ROI-RK Method

Directory of Open Access Journals (Sweden)

Yue Zhao

2014-01-01

Full Text Available ROI-RK method is a biopsy needle localization and tracking method. Previous research work has proved that it has a robust performance on different series of simulated 3D US volumes. Unfortunately, in real situations, because of the strong speckle noise of the ultrasound image and the different echogenic properties of the tissues, the real 3D US volumes have more complex background than the simulated images used previously. In this paper, to adapt the ROI-RK method in real 3D US volumes, a line-filter enhancement calculation only in the ROI is added to increase the contrast between the needle and background tissue, decreasing the phenomenon of expansion of the biopsy needle due to reverberation of ultrasound in the needle. To make the ROI-RK method more stable, a self-correction system is also implemented. Real data have been acquired on an ex vivo heart of lamb. The result of the ROI-RK method shows that it is capable to localize and track the biopsy needle in real situations, and it satisfies the demand of real-time application.

Determination of rare earth elements in the biological reference materials Pine Needles and Spruce Needles by neutron activation analysis

International Nuclear Information System (INIS)

Machado, C.N.; Maria, S.P.; Saiki, M.; Figueiredo, A.M.G.

1998-01-01

Instrumental neutron activation analysis was applied to determine La, Ce, Nd, Sm, Eu, Tb, Yb, Lu and Sc in two biological reference materials: NIST 1575 Pine Needles and BCR-CRM 101 Spruce Needles. The purpose was to contribute to the reference data for these two reference materials. The results were obtained with a good precision (relative standard deviations less than 15%). For the Pine Needles reference material there are already some proposed values and our results showed, in general, a good agreement with the data published. The contribution of uranium fission products to La, Ce, Nd and Sm was evaluated and considered in the determination of these elements. Interferences in the determination of rare earth elements in biological materials are also discussed. (author)

Microchip electrospray: improvements in spray and signal stability during gradient elution by an inverted postcolumn makeup flow.

Science.gov (United States)

Jung, Stephanie; Effelsberg, Uwe; Tallarek, Ulrich

2011-12-01

Dynamic changes in mobile phase composition during high-performance liquid chromatography (HPLC) gradient elution coupled to mass spectrometry (MS) sensitively affect electrospray modes. We investigate the impact of the eluent composition on spray stability and MS response by infusion and injection experiments with a small tetrapeptide in water-acetonitrile mixtures. The employed HPLC/electrospray (ESI)-MS configuration uses a microchip equipped with an enrichment column, a separation column, and a makeup flow (MUF) channel. One nano pump is connected to the separation column, while a second one delivers solvent of exactly inverted composition to the MUF channel. Both solvent streams are united behind the separation column, before the ESI tip, such that the resulting electrosprayed solution always has identical composition during a gradient elution. Analyte peak parameters without and with MUF compensation are determined and discussed with respect to the electrospray mode and eluent composition. The postcolumn MUF significantly improves spray and signal stability over the entire solvent gradient, without compromising the performance of the HPLC separation column. It can also be conveniently implemented on microchip platforms.

Impact of molecular weight on the formation of electrosprayed chitosan microcapsules as delivery vehicles for bioactive compounds.

Science.gov (United States)

Gómez-Mascaraque, Laura G; Sanchez, Gloria; López-Rubio, Amparo

2016-10-05

The molecular weight of chitosan is one of its most determinant characteristics, which affects its processability and its performance as a biomaterial. However, information about the effect of this parameter on the formation of electrosprayed chitosan microcapsules is scarce. In this work, the impact of chitosan molecular weight on its electrosprayability was studied and correlated with its effect on the viscosity, surface tension and electrical conductivity of solutions. A Discriminant Function Analysis revealed that the morphology of the electrosprayed chitosan materials could be correctly predicted using these three parameters for almost 85% of the samples. The suitability of using electrosprayed chitosan capsules as carriers for bioactive agents was also assessed by loading them with a model active compound, (-)-epigallocatechin gallate (EGCG). This encapsulation, with an estimated efficiency of around 80% in terms of preserved antioxidant activity, showed the potential to prolong the antiviral activity of EGCG against murine norovirus via gradual bioactive release combined with its protection against degradation in simulated physiological conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

The exploration of endocytic mechanisms of PLA-PEG nanoparticles prepared by coaxialtri-capillary electrospray-template removal method.

Science.gov (United States)

Chen, Jiaming; Cao, Lihua; Cui, Yuecheng; Tu, Kehua; Wang, Hongjun; Wang, Li-Qun

2018-01-01

The nano-sized poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) particles with core-shell structure were efficiently prepared by using coaxial tri-capillary electrospray-template removal method. The cellular uptake mechanism, intracellular distribution and exocytosis in A549 cell model of electrosprayed PLA-PEG nanoparticles were systemically studied. The drug release behavior of electrosprayed PLA-PEG nanoparticles were also investigated. Our results showed that PLA-PEG nanoparticles can be endocytosed quickly by A549 cells. The cellular uptake of PLA-PEG nanoparticles was an energy dependent endocytosis process. Caveolae-mediated endocytosis was only one of endocytosis pathways in A549 cells for PLA-PEG nanoparticles, while clathrin mediated endocytosis was not involved in the endocytosis process. The endocytosed PLA-PEG nanoparticles enriched in the head of A549 cells and only a small amount of them was transported into lysosome after 24h incubation. These findings provided insights into the application of electrosprayed PLA-PEG nanoparticles in nano drug delivery field. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel design of honeybee-inspired needles for percutaneous procedure.

Science.gov (United States)

Sahlabadi, Mohammad; Hutapea, Parsaoran

2018-04-18

The focus of this paper is to present new designs of innovative bioinspired needles to be used during percutaneous procedures. Insect stingers have been known to easily penetrate soft tissues. Bioinspired needles mimicking the barbs in a honeybee stinger were developed for a smaller insertion force, which can provide a less invasive procedure. Decreasing the insertion force will decrease the tissue deformation, which is essential for more accurate targeting. In this study, some design parameters, in particular, barb shape and geometry (i.e. front angle, back angle, and height) were defined, and their effects on the insertion force were investigated. Three-dimensional printing technology was used to manufacture bioinspired needles. A specially-designed insertion test setup using tissue mimicking polyvinyl chloride (PVC) gels was developed to measure the insertion and extraction forces. The barb design parameters were then experimentally modified through detailed experimental procedures to further reduce the insertion force. Different scales of the barbed needles were designed and used to explore the size-scale effect on the insertion force. To further investigate the efficacy of the proposed needle design in real surgeries, preliminary ex vivo insertion tests into bovine liver tissue were performed. Our results show that the insertion force of the needles in different scales decreased by 21-35% in PVC gel insertion tests, and by 46% in bovine liver tissue insertion tests.

Skin Blood Perfusion and Cellular Response to Insertion of Insulin Pen Needles With Different Diameters

DEFF Research Database (Denmark)

Præstmark, Kezia Ann; Stallknecht, Bente Merete; Bo Jensen, Casper

2014-01-01

skin blood perfusion response around needle insertion sites. Three common sized pen needles of 28G, 30G, and 32G as well as hooked 32G needles, were inserted into the neck skin of pigs and then removed. Laser Speckle Contrast Analysis was used to measure skin blood perfusion for 20 minutes after...... blood perfusion recording and grouped according to needle type, skin blood perfusion response relates to needle diameter. The response was significantly higher after insertions with 28G and hooked 32G needles than with 30G (P ..., but there was a trend of an increased response with increasing needle diameter. Skin blood perfusion response to pen needle insertions rank according to needle diameter, and the tissue response caused by hooked 32G needles corresponds to that of 28G needles. The relation between needle diameter and trauma when...

Direct analysis of triterpenes from high-salt fermented cucumbers using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI)

Science.gov (United States)

High-salt samples present a challenge to mass spectrometry (MS) analysis, particularly when electrospray ionization (ESI) is used, requiring extensive sample preparation steps such as desalting, extraction, and purification. In this study, infrared matrix-assisted laser desorption electrospray ioniz...

Afterdischarges following M waves in patients with voltage-gated potassium channels antibodies

Directory of Open Access Journals (Sweden)

Jingwen Niu

Full Text Available Objective: To explore the correlation between afterdischarges in motor nerve conduction studies and clinical motor hyperexcitability in patients with voltage-gated potassium channels (VGKC antibodies. Methods: Six patients with positive serum antibodies to contactin-associated protein-like 2 (CASPR2 or/and leucine-rich glioma-inactivated protein 1 (LGI1 were recruited, including 5 with autoimmune encephalitis, and 1 with cramp-fasciculation syndrome. Electromyography (EMG, nerve conduction studies (NCS and F waves were performed, and afterdischarges were assessed. One patient was followed up. Results: Five patients had clinical evidence of peripheral motor nerve hyperexcitability (myokymia or cramp, and four of them had abnormal spontaneous firing in concentric needle electromyography (EMG. Prolonged afterdischarges following normal M waves were present in all six patients, including the two patients who had no EMG evidence of peripheral nerve hyperexcitability (PNH. Afterdischarges disappeared after treatment with intravenous immunoglobulin (IVIG. Conclusion: The afterdischarges in motor nerve conduction study might be a sensitive indicator of peripheral motor nerve hyperexcitability in patients with VGKC antibodies. Significance: Afterdischarges in motor nerve conduction study might be more sensitive than needle electromyography for detecting peripheral motor nerve hyperexcitability, and could disappear gradually in accordance with clinical improvement and reduction of antibodies. Keywords: Afterdischarges, VGKC, Autoimmune encephalitis, Peripheral nerve hyperexcitability, F wave, M wave

Fine needle diagnosis in lumbar osteomyelitis

International Nuclear Information System (INIS)

Joshi, K.B.; Brinker, R.A.

1983-01-01

Lumbar vertebral body and disk infection, presenting as low back pain, is a relatively uncommon disease but is seen more often in drug addicts. Radiographs show typical changes of infection of the lumbar vertebrae and adjacent disc. Under local anesthesia a fine needle is placed, saline injected, and aspirated. The entire needle-syringe unit is submitted to the bacteriology department. Pseudomonas infection is usually found. This method of diagnosis is simple, cost effective, well accepted by the patients, and can be done on outpatients. (orig.)

Kalman filter-based EM-optical sensor fusion for needle deflection estimation.

Science.gov (United States)

Jiang, Baichuan; Gao, Wenpeng; Kacher, Daniel; Nevo, Erez; Fetics, Barry; Lee, Thomas C; Jayender, Jagadeesan

2018-04-01

In many clinical procedures such as cryoablation that involves needle insertion, accurate placement of the needle's tip at the desired target is the major issue for optimizing the treatment and minimizing damage to the neighboring anatomy. However, due to the interaction force between the needle and tissue, considerable error in intraoperative tracking of the needle tip can be observed as needle deflects. In this paper, measurements data from an optical sensor at the needle base and a magnetic resonance (MR) gradient field-driven electromagnetic (EM) sensor placed 10 cm from the needle tip are used within a model-integrated Kalman filter-based sensor fusion scheme. Bending model-based estimations and EM-based direct estimation are used as the measurement vectors in the Kalman filter, thus establishing an online estimation approach. Static tip bending experiments show that the fusion method can reduce the mean error of the tip position estimation from 29.23 mm of the optical sensor-based approach to 3.15 mm of the fusion-based approach and from 39.96 to 6.90 mm, at the MRI isocenter and the MRI entrance, respectively. This work established a novel sensor fusion scheme that incorporates model information, which enables real-time tracking of needle deflection with MRI compatibility, in a free-hand operating setup.

Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

Science.gov (United States)

... Physician Resources Professions Site Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid An ... Aspiration Biopsy of the Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? During ...

Oblique needle segmentation and tracking for 3D TRUS guided prostate brachytherapy

International Nuclear Information System (INIS)

Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

2005-01-01

An algorithm was developed in order to segment and track brachytherapy needles inserted along oblique trajectories. Three-dimensional (3D) transrectal ultrasound (TRUS) images of the rigid rod simulating the needle inserted into the tissue-mimicking agar and chicken breast phantoms were obtained to test the accuracy of the algorithm under ideal conditions. Because the robot possesses high positioning and angulation accuracies, we used the robot as a ''gold standard,'' and compared the results of algorithm segmentation to the values measured by the robot. Our testing results showed that the accuracy of the needle segmentation algorithm depends on the needle insertion distance into the 3D TRUS image and the angulations with respect to the TRUS transducer, e.g., at a 10 deg. insertion anglulation in agar phantoms, the error of the algorithm in determining the needle tip position was less than 1 mm when the insertion distance was greater than 15 mm. Near real-time needle tracking was achieved by scanning a small volume containing the needle. Our tests also showed that, the segmentation time was less than 60 ms, and the scanning time was less than 1.2 s, when the insertion distance into the 3D TRUS image was less than 55 mm. In our needle tracking tests in chicken breast phantoms, the errors in determining the needle orientation were less than 2 deg. in robot yaw and 0.7 deg. in robot pitch orientations, for up to 20 deg. needle insertion angles with the TRUS transducer in the horizontal plane when the needle insertion distance was greater than 15 mm

Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles

OpenAIRE

Cronn, Richard; Dolan, Peter C.; Jogdeo, Sanjuro; Wegrzyn, Jill L.; Neale, David B.; St. Clair, J. Bradley; Denver, Dee R.

2017-01-01

Background Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) n...

Coordinated Voltage Control of Distributed PV Inverters for Voltage Regulation in Low Voltage Distribution Networks

DEFF Research Database (Denmark)

Nainar, Karthikeyan; Pokhrel, Basanta Raj; Pillai, Jayakrishnan Radhakrishna

2017-01-01

This paper reviews and analyzes the existing voltage control methods of distributed solar PV inverters to improve the voltage regulation and thereby the hosting capacity of a low-voltage distribution network. A novel coordinated voltage control method is proposed based on voltage sensitivity...... optimization. The proposed method is used to calculate the voltage bands and droop settings of PV inverters at each node by the supervisory controller. The local controller of each PV inverter implements the volt/var control and if necessary, the active power curtailment as per the received settings and based...... on measured local voltages. The advantage of the proposed method is that the calculated reactive power and active power droop settings enable fair contribution of the PV inverters at each node to the voltage regulation. Simulation studies are conducted using DigSilent Power factory software on a simplified...

Terverticillate Penicillia studied by direct electrospray mass spectrometric profiling of crude extracts: I. Chemosystematics

DEFF Research Database (Denmark)

Smedsgaard, Jørn; Frisvad, Jens Christian

1997-01-01

) and Yeast Extract Sucrose agar (YES) directly into the electrospray source of the mass spectrometer. A data matrix was made from each substrate by transferring the complete centroid mass spectrum from 200 to 700 amu as 501 variables to individual columns. No attempt was made to identify ions in the mass......A chemosystematic study of 339 isolates from all known terverticillate Penicillium taxa was performed using electrospray mass spectrometric analysis of extractable metabolites. The mass profiles were made by injecting crude plug extracts made from cultures grown on Czapek Yeast Autolysate agar (CYA...

[Professor Feng Run-Shen's essential experience in penetration needling method].

Science.gov (United States)

Feng, Mu-Lan

2009-04-01

Professor Feng Run-Shen is engaged in medicine for more than 60 years. He pays attention to medical ethics and has perfect medical skill. He energetically advocates combination of acupuncture with medication and stresses the concept of viewing the situation as a whole in selection of acupoints and treatment, particularly, clinical application of point properties. Clinically, he is accomplished in penetration needling, for which one needle acts on two or more points, enlarging the range of needling sensation, so it has very good therapeutic effects on many diseases. In the paper, the case samples about penetration needling in his clinical practice are summarized and introduced.

Fine Needle Aspiration Cytology In Tumour Diagnosis | Obaseki ...

African Journals Online (AJOL)

Fine needle aspiration cytology (FNAC), a technique for obtaining cellular material for cytological examination and diagnosis using a 21- gauge or smaller needle, is performed using a 5, 10, or 20ml syringe either freehand or using special syringe holders. It allows a minimally invasive, rapid diagnosis of tissue samples but

Improved radionuclide bone imaging agent injection needle withdrawal method can improve image quality

International Nuclear Information System (INIS)

Qin Yongmei; Wang Laihao; Zhao Lihua; Guo Xiaogang; Kong Qingfeng

2009-01-01

Objective: To investigate the improvement of radionuclide bone imaging agent injection needle withdrawal method on whole body bone scan image quality. Methods: Elbow vein injection syringe needle directly into the bone imaging agent in the routine group of 117 cases, with a cotton swab needle injection method for the rapid pull out the needle puncture point pressing, pressing moment. Improvement of 117 cases of needle injection method to put two needles into the skin swabs and blood vessels, pull out the needle while pressing two or more entry point 5min. After 2 hours underwent whole body bone SPECT imaging plane. Results: The conventional group at the injection site imaging agents uptake rate was 16.24%, improved group was 2.56%. Conclusion: The modified bone imaging agent injection needle withdrawal method, injection-site imaging agent uptake were significantly decreased whole body bone imaging can improve image quality. (authors)

Needle-free influenza vaccination

NARCIS (Netherlands)

Amorij, Jean-Pierre; Hinrichs, Wouter L.J.; Frijlink, Henderik W.; Wilschut, Jan C.; Huckriede, Anke

2010-01-01

Vaccination is the cornerstone of influenza control in epidemic and pandemic situations. Influenza vaccines are typically given by intramuscular injection. However, needle-free vaccinations could offer several distinct advantages over intramuscular injections: they are pain-free, easier to

Helical-Tip Needle for Transthoracic Percutaneous Image-Guided Biopsy of Lung Tumors: Results of a Pilot Prospective Comparative Study with a Standard Tru-Cut Needle

Energy Technology Data Exchange (ETDEWEB)

Veltri, Andrea, E-mail: andrea.veltri@unito.it; Busso, Marco; Sardo, Diego; Angelino, Valeria; Priola, Adriano M. [University of Torino, Department of Radiology, San Luigi Gonzaga Hospital (Italy); Novello, Silvia [University of Torino, Department of Oncology, San Luigi Gonzaga Hospital (Italy); Barba, Matteo [University of Torino, Department of Radiology, San Luigi Gonzaga Hospital (Italy); Gatti, Gaia; Righi, Luisella [University of Torino, Department of Pathology, San Luigi Gonzaga Hospital (Italy)

2017-06-15

PurposeTo prospectively evaluate feasibility and diagnostic performance of the 14-gauge helical-tip (Spirotome™, Cook{sup ®} Medical, Bloomington, USA) needle in transthoracic needle biopsy (TTNB) of lung lesions, compared to a conventional 18-gauge Tru-Cut needle.Materials and MethodsStudy was institutional review board approved, with informed consent obtained. Data from synchronous Spirotome and Tru-Cut image-guided TTNB of 20 consecutive patients with malignant peripheral lung tumors larger than 3 cm were enrolled for pathologic characterization and mutational analysis. Samples obtained with Spirotome and Tru-Cut needle were compared for fragmentation, length, weight, morphologic and immunohistochemistry typifying, tumor cellularity (TC) and DNA concentration.ResultsThe technical success rate for TTNB with Spirotome was 100%, and no major complications occurred. Less fragmentation (mean 2 vs. 3 fragments, P = .418), greater weight (mean 13 vs. 8.5 mg, P = .027) and lower length (mean 10.2 vs. 12.6 mm, P = .174) were observed with Spirotome compared to Tru-Cut needle. Accuracy of Spirotome and Tru-Cut needle in defining cancer histotype was similar (90%). Absolute and relative TC (mean 42 vs. 38, 124 vs. 108/10HPF), and DNA concentration (mean 49.6 vs. 39.0 ng/μl) were higher with Spirotome compared to Tru-Cut needle, with no statistical significance (P = .787 and P = .140, respectively).Conclusions Percutaneous 14-gauge Spirotome TTNB of selected lesions is feasible and accurate. It provides adequate samples for diagnosis, comparable to 18-gauge Tru-Cut needle, with a higher amount of tumor tissue (weight, TC, DNA concentration) even in shorter samples.

A variable stiffness mechanism for steerable percutaneous instruments: integration in a needle.

Science.gov (United States)

De Falco, Iris; Culmone, Costanza; Menciassi, Arianna; Dankelman, Jenny; van den Dobbelsteen, John J

2018-06-04

Needles are advanced tools commonly used in minimally invasive medical procedures. The accurate manoeuvrability of flexible needles through soft tissues is strongly determined by variations in tissue stiffness, which affects the needle-tissue interaction and thus causes needle deflection. This work presents a variable stiffness mechanism for percutaneous needles capable of compensating for variations in tissue stiffness and undesirable trajectory changes. It is composed of compliant segments and rigid plates alternately connected in series and longitudinally crossed by four cables. The tensioning of the cables allows the omnidirectional steering of the tip and the stiffness tuning of the needle. The mechanism was tested separately under different working conditions, demonstrating a capability to exert up to 3.6 N. Afterwards, the mechanism was integrated into a needle, and the overall device was tested in gelatine phantoms simulating the stiffness of biological tissues. The needle demonstrated the capability to vary deflection (from 11.6 to 4.4 mm) and adapt to the inhomogeneity of the phantoms (from 21 to 80 kPa) depending on the activation of the variable stiffness mechanism. Graphical abstract ᅟ.

A study on applying Ra needle interstitial brachytherapy for oral cancer

International Nuclear Information System (INIS)

Yoshida, Shunichi; Komiya, Yoshiaki; Uchida, Ikuhiro; Tashiro, Kazuyoshi

1999-01-01

To investigate applicability of Ra needle interstitial brachytherapy, 93 cases of oral squamous carcinoma were examined. The patients underwent Ra needle interstitial brachytherapy as thorough therapy in our hospital. The criteria of applying Ra needle interstitial brachytherapy was diameter of within 5 cm and depth within 2 cm of tumor size. Ra needle interstitial brachytherapy was applied to 82 cases of tongue, 10 cases of oral floor and one case of lower lip carcinomas. The local control rate was 92.5%, and secondary neck metastasis was 32.3% in all cases applied Ra needle interstitial brachytherapy. The results were not bad compared with surgical treatment. However, the 5-year cumulative survival rate was 64.9%, which was not good enough at the result to obtain a good local control rate and secondary neck metastasis rate. The result was relative to low treatment result of local recurrence cases with Ra needle interstitial brachytherapy. To improve the result, it is important to distinguish local recurrence from radioinduced ulcer, and to start early secondary treatment. The cases in which cervical lymph node metastasis was found as the first examination underwent neck dessection after Ra needle interstitial brachytherapy. The 5-year cumulative survival rate was 83.3% in N1 cases and 40.6% in N2 cases, and the result of N2 cases was poorer than N1 cases with a significant difference. The results indicate that a needle having a diameter of within 5 cm, depth of within 2 cm and less than N1 can be applied during Ra needle interstitial brachytherapy for complete cure of cancer. (author)

SU-D-213AB-06: Surface Texture and Insertion Speed Effect on Needle Friction.

Science.gov (United States)

Abdullah, A; Golecki, C; Barnett, A; Moore, J

2012-06-01

High frictional forces between the needle surface and tissue cause tissue deflection which hinders accurate needle placement for procedures such as brachytherapy and needle biopsy. Accurate needle placement isimportant to maximize procedure efficacy. This work investigates how needle surface roughness and insertion speed affect the frictional forcebetween a needle and tissue. A friction experiment was conducted to measure the force of friction between bovine liver and three 11 gauge needles having Ra surface roughness of 3.43, 1.33, and 0.2 μm. Each of the three needles were mounted on a linear slide and were advanced and retracted through bovine liver at speeds of 50, 100, 150, and 200 mm/s for a total of 12 trials. In each trial the needle was advanced and retracted in 10 cycles producing a steady state insertion force and a steady state retraction force for each cycle. A force sensor connecting the needle to the linear slide recorded the resistance force of the needle sliding through the liver. The liver was mounted in a box with a pneumatic cylinder which compressed the liver sample by 11.65 kPa. The roughest needle (Ra = 3.43 μm) on average produced 68, 73, 74, and 73% lower friction force than the smoothest needle (Ra = 0.2 μm) for the speeds of 50, 100, 150, and 200mm/s, respectively. The second roughest needle (Ra = 1.33 μm) on average produced 25, 45, 60 and 64% lower friction force than the smoothest needle (Ra = 0.2 μm) for the speeds of 50, 100, 150, and 200 mm/s, respectively. Rougher needle surface texture and higher insertion speed reduced frictional forces between the tissue and the needle. Future studies will examine how frictional forces can be modeled and predicted given surface texture and insertion speed. © 2012 American Association of Physicists in Medicine.

Students as effective harm reductionists and needle exchange organizers.

Science.gov (United States)

Barbour, Kyle; McQuade, Miriam; Brown, Brandon

2017-03-17

Needle exchange programs are safe, highly effective programs for promoting health among people who inject drugs. However, they remain poorly funded, and often illegal, in many places worldwide due to fear and stigma surrounding drug use. Continued advocacy, education, and implementation of new needle exchanges are thus essential to improve public health and reduce structural inequality. We argue that students, and especially professional and graduate students, have the potential to play an important role in advancing harm reduction. Students benefit from the respect given to the professions they are training to enter, which gives them leverage to navigate the political hurdles often faced by needle exchange organizers, especially in areas that presently lack services. In addition, due to their relative simplicity, needle exchanges do not require much of the licensing, clinical knowledge, and infrastructure associated with more traditional student programs, such as student-run free medical clinics. Students are capable of learning harm reduction cultural approaches and techniques if they remain humble, open-minded, and seek the help of the harm reduction community. Consequently, students can generate tremendous benefits to their community without performing beyond their appropriate clinical limitations. Students benefit from organizing needle exchanges by gaining applied experience in advocacy, organization-building, and political finesse. Working in a needle exchange significantly helps erode stigma against multiple marginalized populations. Students in health-related professions additionally learn clinically-relevant knowledge that is often lacking from their formal training, such as an understanding of structural violence and inequality, root causes of substance use, client-centered approaches to health services, and interacting with clients as peers, rather than through the standard hierarchical medical interaction. We therefore encourage students to learn about

Smartphone-Guided Needle Angle Selection During CT-Guided Procedures.

Science.gov (United States)

Xu, Sheng; Krishnasamy, Venkatesh; Levy, Elliot; Li, Ming; Tse, Zion Tsz Ho; Wood, Bradford John

2018-01-01

In CT-guided intervention, translation from a planned needle insertion angle to the actual insertion angle is estimated only with the physician's visuospatial abilities. An iPhone app was developed to reduce reliance on operator ability to estimate and reproduce angles. The iPhone app overlays the planned angle on the smartphone's camera display in real-time based on the smartphone's orientation. The needle's angle is selected by visually comparing the actual needle with the guideline in the display. If the smartphone's screen is perpendicular to the planned path, the smartphone shows the Bull's-Eye View mode, in which the angle is selected after the needle's hub overlaps the tip in the camera. In phantom studies, we evaluated the accuracies of the hardware, the Guideline mode, and the Bull's-Eye View mode and showed the app's clinical efficacy. A proof-of-concept clinical case was also performed. The hardware accuracy was 0.37° ± 0.27° (mean ± SD). The mean error and navigation time were 1.0° ± 0.9° and 8.7 ± 2.3 seconds for a senior radiologist with 25 years' experience and 1.5° ± 1.3° and 8.0 ± 1.6 seconds for a junior radiologist with 4 years' experience. The accuracy of the Bull's-Eye View mode was 2.9° ± 1.1°. Combined CT and smart-phone guidance was significantly more accurate than CT-only guidance for the first needle pass (p = 0.046), which led to a smaller final targeting error (mean distance from needle tip to target, 2.5 vs 7.9 mm). Mobile devices can be useful for guiding needle-based interventions. The hardware is low cost and widely available. The method is accurate, effective, and easy to implement.

Detection of Membrane Puncture with Haptic Feedback using a Tip-Force Sensing Needle.

Science.gov (United States)

Elayaperumal, Santhi; Bae, Jung Hwa; Daniel, Bruce L; Cutkosky, Mark R

2014-09-01

This paper presents calibration and user test results of a 3-D tip-force sensing needle with haptic feedback. The needle is a modified MRI-compatible biopsy needle with embedded fiber Bragg grating (FBG) sensors for strain detection. After calibration, the needle is interrogated at 2 kHz, and dynamic forces are displayed remotely with a voice coil actuator. The needle is tested in a single-axis master/slave system, with the voice coil haptic display at the master, and the needle at the slave end. Tissue phantoms with embedded membranes were used to determine the ability of the tip-force sensors to provide real-time haptic feedback as compared to external sensors at the needle base during needle insertion via the master/slave system. Subjects were able to determine the position of the embedded membranes with significantly better accuracy using FBG tip feedback than with base feedback using a commercial force/torque sensor (p = 0.045) or with no added haptic feedback (p = 0.0024).

A needle guidance system for biopsy and therapy using two-dimensional ultrasound

International Nuclear Information System (INIS)

Bluvol, Nathan; Sheikh, Allison; Kornecki, Anat; Del Rey Fernandez, David; Downey, Donal; Fenster, Aaron

2008-01-01

Image-guided needle biopsies are currently used to provide a definitive diagnosis of breast cancer; however, difficulties in tumor targeting exist as the ultrasound (United States) scan plane and biopsy needle must remain coplanar throughout the procedure to display the actual needle tip position. The additional time associated with aligning and maintaining this coplanar relationship results in increased patient discomfort. Biopsy procedural efficiency is further hindered since needle pathway interpretation is often difficult, especially for needle insertions at large depths that usually require multiple reinsertions. The authors developed a system that would increase the speed and accuracy of current breast biopsy procedures using readily available two-dimensional (2D) US technology. This system is composed of a passive articulated mechanical arm that attaches to a 2D US transducer. The arm is connected to a computer through custom electronics and software, which were developed as an interface for tracking the positioning of the mechanical components in real time. The arm couples to the biopsy needle and provides visual guidance for the physician performing the procedure in the form of a real-time projected needle pathway overlay on an US image of the breast. An agar test phantom, with stainless steel targets interspersed randomly throughout, was used to validate needle trajectory positioning accuracy. The biopsy needle was guided by both the software and hardware components to the targets. The phantom, with the needle inserted and device decoupled, was placed in an x-ray stereotactic mammography (SM) machine. The needle trajectory and bead target locations were determined in three dimensions from the SM images. Results indicated a mean needle trajectory accuracy error of 0.75±0.42 mm. This is adequate to sample lesions that are <2 mm in diameter. Chicken tissue test phantoms were used to compare core needle biopsy procedure times between experienced radiologists

In vivo motion and force measurement of surgical needle intervention during prostate brachytherapy

International Nuclear Information System (INIS)

Podder, Tarun; Clark, Douglas; Sherman, Jason; Fuller, Dave; Messing, Edward; Rubens, Deborah; Strang, John; Brasacchio, Ralph; Liao, Lydia; Ng, W.-S.; Yu Yan

2006-01-01

In this paper, we present needle insertion forces and motion trajectories measured during actual brachytherapy needle insertion while implanting radioactive seeds in the prostate glands of 20 different patients. The needle motion was captured using ultrasound images and a 6 degree-of-freedom electromagnetic-based position sensor. Needle velocity was computed from the position information and the corresponding time stamps. From in vivo data we found the maximum needle insertion forces to be about 15.6 and 8.9 N for 17 gauge (1.47 mm) and 18 gauge (1.27 mm) needles, respectively. Part of this difference in insertion forces is due to the needle size difference (17G and 18G) and the other part is due to the difference in tissue properties that are specific to the individual patient. Some transverse forces were observed, which are attributed to several factors such as tissue heterogeneity, organ movement, human factors in surgery, and the interaction between the template and the needle. However, theses insertion forces are significantly responsible for needle deviation from the desired trajectory and target movement. Therefore, a proper selection of needle and modulated velocity (translational and rotational) may reduce the tissue deformation and target movement by reducing insertion forces and thereby improve the seed delivery accuracy. The knowledge gleaned from this study promises to be useful for not only designing mechanical/robotic systems but also developing a predictive deformation model of the prostate and real-time adaptive controlling of the needle

[Treatment of Persistent Somatoform Pain Disorder by Floating Needle Therapy and Duloxetine].

Science.gov (United States)

Ren, Wan-wen; Zhou, Zhi-ying; Xu, Mi-mi; Long, Sen; Tang, Guang-zheng; Mao, Hong-jing; Chen, Shu-lin

2016-02-01

To evaluate clinical effect and safety of floating needle therapy and duloxetine in treating patients with persistent somatoform pain disorder (PSPD). Totally 108 PSPD patients were randomly assigned to the floating needle treatment group, the duloxetine treatment group, and the placebo treatment group, 36 in each group. Patients in the floating needle treatment group received floating needle therapy and placebo. Those in the duloxetine treatment group received duloxetine and simulated floating needle therapy. Those in the placebo treatment group received the placebo and simulated floating needle therapy. All treatment lasted for six weeks. Efficacy and adverse reactions were evaluated using Simple McGill pain scale (SF-MPQ) and Treatment Emergent Symptom Scale (TESS) before treatment and immediately after treatment, as well as at the end of 1st, 2nd, 4th, and 6th week of treatment, respectively. Hamilton Depression Scale (HAMD, 17 items), Hamilton Anxiety Scale (HAMA) were assessed before treatment and at the end of 1st, 2nd, 4th, and 6th week of treatment, respectively. Patients in the floating needle treatment group and the duloxetine treatment group with the total reducing score rate of SF-MPQ in Pain Rating index (PRI) ≥ 50% after 6 weeks' treatment were involved in the follow-up study. (1) Compared with the same group before treatment, SF-MPQ score, HAMD score and HAMA total scores all decreased in all the three groups at the end of 1st, 2nd, 4th, and 6th week of treatment (P floating needle treatment group (P floating needle treatment group significantly decreased after 1, 2, 4, and 6 weeks of treatment (P floating needle treatment group, 17 (50.0%) in the duloxetine treatment group, and 7 (21.2%) in the placebo treatment group. Compared with the placebo treatment group, the incidence of adverse reaction increased in the duloxetine treatment group (χ² = 6.04, P floating needle treatment group (χ² = 14.9, P floating needle treatment group and 17

NEEDLE KNIFE SPHINCTEROTOMY - THE CHRIS HANI BARAGWANATH ACADEMIC HOSPITAL EXPERIENCE.

Science.gov (United States)

Thomson, J T; Smith, M D; Omoshoro-Jones, J A O; Devar, J D; Khan, Z K; Jugmohan, B J

2017-06-01

Deep biliary cannulation is essential in performing a therapeutic ERCP. Cannulation can be enhanced through the utilization of a pre-cut by means of a needle knife sphincterotomy. Retrospective analysis of the Chris Hani Baragwanath Academic Hospital's ERCP database was performed. All ERCPs performed with the aid of a needle knife were identified and analysed for successful and unsuccessful deep biliary cannulation. 2830 ERCPs were performed during the study period. 369 (13%) required needle knife sphincterotomies and successful deep biliary cannulation was achieved in 229 (62%) of these patients. Repeat ERCPs were performed on 125 (34%) patients. 61 (49%) of the repeat ERCPs were performed because of previously failed cannulation. 34 (56%) of these repeat ERCPs resulted in successful deep biliary cannulation at re-attempt. 99% of successful cannulations at repeat ERCP had had a needle knife sphincterotomy at the first ERCP. Needle knife sphincterotomy improves deep biliary cannulation at initial ERCP and subsequent ERCPs with low incidences of complications.

Acupuncture sensation during ultrasound guided acupuncture needling

Science.gov (United States)

Park, Jongbae J.; Akazawa, Margeaux; Ahn, Jaeki; Beckman-Harned, Selena; Lin, Feng-Chang; Lee, Kwangjae; Fine, Jason; Davis, Robert T; Langevin, Helene

2014-01-01

Background Although acupuncture sensation (also known as de qi) is a cornerstone of traditional acupuncture therapy, most research has accepted the traditional method of defining acupuncture sensation only through subjective patient reports rather than on any quantifiable physiological basis. Purpose To preliminarily investigate the frequency of key sensations experienced while needling to specific, quantifiable tissue levels (TLs) guided by ultrasound (US) imaging. Methods Five participants received needling at two acupuncture points and two control points at four TLs. US scans were used to determine when each TL was reached. Each volunteer completed 32 sets of modified Southampton Needle Sensation Questionnaires. Part one of the study tested sensations experienced at each TL and part two compared the effect of oscillation alone versus oscillation + rotation. Results In all volunteers, the frequency of pricking, sharp sensations was significantly greater in shallower TLs than deeper (p=0.007); the frequency of sensations described as deep, dull and heavy, as spreading, and as electric shocks was significantly greater in deeper TLs than shallower (p=0.002). Sensations experienced did not significantly differ between real and control points within each of three TLs (p>0.05) except TL 4 (p=0.006). The introduction of needle rotation significantly increased deep, dull, heavy sensations, but not pricking and sharp sensations; within each level, the spectrum of sensation experienced during both oscillation + rotation and oscillation alone did not significantly differ between acupuncture and control points. Conclusion The preliminary study indicates a strong connection between acupuncture sensation and both tissue depth and needle rotation. Furthermore, the new methodology has been proven feasible. A further study with an objective measurement is warranted. PMID:21642648

Transcription Through The Eye Of A Needle: Daily And Annual Cycles Of Gene Expression Variation In Douglas-Fir Needles

OpenAIRE

Dolan, Peter; Cronn, Richard; Denver, Dee; Clair, J.; Neale, David; Wegrzyn, Jill; Jogdeo, Sanjuro

2017-01-01

Background: Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal rhythms and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii)...

Biocompatible 3D printed magnetic micro needles

KAUST Repository

Kavaldzhiev, Mincho

2017-01-30

Biocompatible functional materials play a significant role in drug delivery, tissue engineering and single cell analysis. We utilized 3D printing to produce high aspect ratio polymer resist microneedles on a silicon substrate and functionalized them by iron coating. Two-photon polymerization lithography has been used for printing cylindrical, pyramidal, and conical needles from a drop cast IP-DIP resist. Experiments with cells were conducted with cylindrical microneedles with 630 ± 15 nm in diameter with an aspect ratio of 1:10 and pitch of 12 μm. The needles have been arranged in square shaped arrays with various dimensions. The iron coating of the needles was 120 ± 15 nm thick and has isotropic magnetic behavior. The chemical composition and oxidation state were determined using energy electron loss spectroscopy, revealing a mixture of iron and Fe3O4 clusters. A biocompatibility assessment was performed through fluorescence microscopy using calcein/EthD-1 live/dead assay. The results show a very high biocompatibility of the iron coated needle arrays. This study provides a strategy to obtain electromagnetically functional microneedles that benefit from the flexibility in terms of geometry and shape of 3D printing. Potential applications are in areas like tissue engineering, single cell analysis or drug delivery.

Biocompatible 3D printed magnetic micro needles

KAUST Repository

Kavaldzhiev, Mincho; Perez, Jose E.; Ivanov, Yurii; Bertoncini, Andrea; Liberale, Carlo; Kosel, Jü rgen

2017-01-01

Biocompatible functional materials play a significant role in drug delivery, tissue engineering and single cell analysis. We utilized 3D printing to produce high aspect ratio polymer resist microneedles on a silicon substrate and functionalized them by iron coating. Two-photon polymerization lithography has been used for printing cylindrical, pyramidal, and conical needles from a drop cast IP-DIP resist. Experiments with cells were conducted with cylindrical microneedles with 630 ± 15 nm in diameter with an aspect ratio of 1:10 and pitch of 12 μm. The needles have been arranged in square shaped arrays with various dimensions. The iron coating of the needles was 120 ± 15 nm thick and has isotropic magnetic behavior. The chemical composition and oxidation state were determined using energy electron loss spectroscopy, revealing a mixture of iron and Fe3O4 clusters. A biocompatibility assessment was performed through fluorescence microscopy using calcein/EthD-1 live/dead assay. The results show a very high biocompatibility of the iron coated needle arrays. This study provides a strategy to obtain electromagnetically functional microneedles that benefit from the flexibility in terms of geometry and shape of 3D printing. Potential applications are in areas like tissue engineering, single cell analysis or drug delivery.

Toward single-cell analysis by plume collimation in laser ablation electrospray ionization mass spectrometry.

Science.gov (United States)

Stolee, Jessica A; Vertes, Akos

2013-04-02

Ambient ionization methods for mass spectrometry have enabled the in situ and in vivo analysis of biological tissues and cells. When an etched optical fiber is used to deliver laser energy to a sample in laser ablation electrospray ionization (LAESI) mass spectrometry, the analysis of large single cells becomes possible. However, because in this arrangement the ablation plume expands in three dimensions, only a small portion of it is ionized by the electrospray. Here we show that sample ablation within a capillary helps to confine the radial expansion of the plume. Plume collimation, due to the altered expansion dynamics, leads to greater interaction with the electrospray plume resulting in increased ionization efficiency, reduced limit of detection (by a factor of ~13, reaching 600 amol for verapamil), and extended dynamic range (6 orders of magnitude) compared to conventional LAESI. This enhanced sensitivity enables the analysis of a range of metabolites from small cell populations and single cells in the ambient environment. This technique has the potential to be integrated with flow cytometry for high-throughput metabolite analysis of sorted cells.

[Closed needle-biopsy in the diagnosis of neoplasms].

Science.gov (United States)

Sforza, M; Perelli Ercolini, M; Beani, G

1979-04-01

The AA. demonstrate with this communication the validity of the needle biopsie for the diagnosis of neoplasms. They had used it for the breast, thyroid, flg and some other superficial tumefactions. In the mass-screening for the feminine neoplasms the clinical examination and the needle biopsy are very good method for a careful diagnosis.

Mitigation of Voltage Sags in CIGRE Low Voltage Distribution Network

DEFF Research Database (Denmark)

Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar

2013-01-01

Any problem in voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM), Dynamic Voltage Restorer (DVR) etc. are commonly used for the mitigation of voltage p....... The compensation of voltage sags in the different parts of CIGRE distribution network is done by using the four STATCOM compensators already existing in the test grid. The simulations are carried out in DIgSILENT power factory software version 15.0.......Any problem in voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM), Dynamic Voltage Restorer (DVR) etc. are commonly used for the mitigation of voltage...... problems in the distribution system. The voltage problems dealt with in this paper are to show how to mitigate voltage sags in the CIGRE Low Voltage (LV) test network and networks like this. The voltage sags, for the tested cases in the CIGRE LV test network are mainly due to three phase faults...

Novel piroxicam-loaded nanospheres generated by the electrospraying technique: physicochemical characterisation and oral bioavailability evaluation.

Science.gov (United States)

Mustapha, Omer; Din, Fakhar Ud; Kim, Dong Wuk; Park, Jong Hyuck; Woo, Kyu Bong; Lim, Soo-Jeong; Youn, Yu Seok; Cho, Kwan Hyung; Rashid, Rehmana; Yousaf, Abid Mehmood; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

2016-06-01

To determine if a novel electrospraying technique could be applied to an oral drug delivery system for improving the solubility and oral bioavailability of poorly water-soluble piroxicam; the nanospheres were generated with drug and polyvinylpyrrolidone (PVP) using electrospraying technique; and their physicochemical properties, solubility, release and pharmacokinetics were evaluated in comparison with piroxicam powder. All nanospheres had significantly increased drug solubility and dissolution rates in comparison with the drug powder. In particular, the nanosphere composed of piroxicam and PVP at a weight ratio of 2:8 gave about 600-fold higher solubility, 15-fold higher release rate and 3-fold higher AUC in comparison to piroxicam powder, leading to significantly enhanced oral bioavailability in rats, due to the mingled effect of nanonisation along with transformation to the amorphous state. Thus, this electrospraying technique can be utilised to produce a novel oral nanosphere delivery system with enhanced solubility and oral bioavailability for poorly water-soluble piroxicam.

Options for reducing HIV transmission related to the dead space in needles and syringes.

Science.gov (United States)

Zule, William A; Pande, Poonam G; Otiashvili, David; Bobashev, Georgiy V; Friedman, Samuel R; Gyarmathy, V Anna; Des Jarlais, Don C

2018-01-15

When shared by people who inject drugs, needles and syringes with different dead space may affect the probability of HIV and hepatitis C virus (HCV) transmission differently. We measured dead space in 56 needle and syringe combinations obtained from needle and syringe programs across 17 countries in Europe and Asia. We also calculated the amounts of blood and HIV that would remain in different combinations following injection and rinsing. Syringe barrel capacities ranged from 0.5 to 20 mL. Needles ranged in length from 8 to 38 mm. The average dead space was 3 μL in low dead space syringes with permanently attached needles, 13 μL in high dead space syringes with low dead space needles, 45 μL in low dead space syringes with high dead space needles, and 99 μL in high dead space syringes with high dead space needles. Among low dead space designs, calculated volumes of blood and HIV viral burden were lowest for low dead space syringes with permanently attached needles and highest for low dead space syringes with high dead space needles. The dead space in different low dead space needle and syringe combinations varied substantially. To reduce HIV transmission related to syringe sharing, needle and syringe programs need to combine this knowledge with the needs of their clients.

A uniform laminar air plasma plume with large volume excited by an alternating current voltage

Science.gov (United States)

Li, Xuechen; Bao, Wenting; Chu, Jingdi; Zhang, Panpan; Jia, Pengying

2015-12-01

Using a plasma jet composed of two needle electrodes, a laminar plasma plume with large volume is generated in air through an alternating current voltage excitation. Based on high-speed photography, a train of filaments is observed to propagate periodically away from their birth place along the gas flow. The laminar plume is in fact a temporal superposition of the arched filament train. The filament consists of a negative glow near the real time cathode, a positive column near the real time anode, and a Faraday dark space between them. It has been found that the propagation velocity of the filament increases with increasing the gas flow rate. Furthermore, the filament lifetime tends to follow a normal distribution (Gaussian distribution). The most probable lifetime decreases with increasing the gas flow rate or decreasing the averaged peak voltage. Results also indicate that the real time peak current decreases and the real time peak voltage increases with the propagation of the filament along the gas flow. The voltage-current curve indicates that, in every discharge cycle, the filament evolves from a Townsend discharge to a glow one and then the discharge quenches. Characteristic regions including a negative glow, a Faraday dark space, and a positive column can be discerned from the discharge filament. Furthermore, the plasma parameters such as the electron density, the vibrational temperature and the gas temperature are investigated based on the optical spectrum emitted from the laminar plume.

Development of a New Cascade Voltage-Doubler for Voltage Multiplication

OpenAIRE

Toudeshki, Arash; Mariun, Norman; Hizam, Hashim; Abdul Wahab, Noor Izzri

2014-01-01

For more than eight decades, cascade voltage-doubler circuits are used as a method to produce DC output voltage higher than the input voltage. In this paper, the topological developments of cascade voltage-doublers are reviewed. A new circuit configuration for cascade voltage-doubler is presented. This circuit can produce a higher value of the DC output voltage and better output quality compared to the conventional cascade voltage-doubler circuits, with the same number of stages.

NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

Science.gov (United States)

Thompson, S. A.; Fung, A. Y. C.; Zaider, M.

2002-08-01

One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.

Ultrasonography-Guided Fine Needle Aspiration Cytology of Cervical Lymphadenopathy: Comparative Study of the Cytological Adequacy Using of 21- and 23- Gauge Needles

International Nuclear Information System (INIS)

Beak, Jin Wook; KIm, Dong Wook; Kim, Bo Mi

2011-01-01

To assess the difference in the cytological adequacy of ultrasonography (US)-guided fine needle aspiration cytology (US-FNAC) for cervical lymphadenopathy using 21 and 23 gauge needles. US-FNACs were separately performed on two cervical lymph nodes and in each patient using 21 gauge (group A) and 23 gauge (group B) needles, respectively. We used 4 grade classifications for the cytological analysis of each slide and compared the cytological adequacy of US-FNAC for cervical lymphadenopathy in the two groups. We performed US-FNACs on 58 cervical lymph nodes from 29 patients, with a cytological adequacy of 69.0%. The number of adequate cytological results was 19 (65.5%) in group A and 21 (72.4%) in group B, and the diagnostic adequacy did not differ significantly between the two groups (Mann-Whitney test, p = 0.574). There was no statistically significant difference in the cytological adequacy of US-FNAC for cervical lymphadenopathy according using of 21 and 23 gauge needles.

Efficacy of Tuohy Needle in Oocytes Collection from Excised Mare Ovaries

Directory of Open Access Journals (Sweden)

F. Cremonesi

2010-01-01

Full Text Available Two methods have been described to recover oocytes from equine follicles in excised ovaries: aspiration and scraping. Aim of this work was to develop an effective method for collecting equine oocytes using Tuohy needle and comparing this technique to aspiration and scraping, with or without tunica albuginea removal. This hollow hypodermic needle, usually employed for inserting epidural catheters, is designed with a slightly curved tip, shaped similar to a small curette. In unpeeled ovaries, the recovery rates of Tuohy needle group was higher (<.05 than in the 16 g needle aspiration and in the scraped ovaries (57% versus 36% and 47% while the rate of cumulus-intact oocytes was higher than aspiration (46.9% versus 39.36% but lower than scraping (46.97% (<.001. In unpeeled ovaries there was significant difference in maturation rate of oocytes recovered by Tuohy needle in respect to peeled ovaries (58.54% versus 50.17%, resp.. Combination of aspiration and scraping by Tuohy needle allows a faster and reliable collection of oocytes suitable for horse IVM.

MLESAC Based Localization of Needle Insertion Using 2D Ultrasound Images

Science.gov (United States)

Xu, Fei; Gao, Dedong; Wang, Shan; Zhanwen, A.

2018-04-01

In the 2D ultrasound image of ultrasound-guided percutaneous needle insertions, it is difficult to determine the positions of needle axis and tip because of the existence of artifacts and other noises. In this work the speckle is regarded as the noise of an ultrasound image, and a novel algorithm is presented to detect the needle in a 2D ultrasound image. Firstly, the wavelet soft thresholding technique based on BayesShrink rule is used to denoise the speckle of ultrasound image. Secondly, we add Otsu’s thresholding method and morphologic operations to pre-process the ultrasound image. Finally, the localization of the needle is identified and positioned in the 2D ultrasound image based on the maximum likelihood estimation sample consensus (MLESAC) algorithm. The experimental results show that it is valid for estimating the position of needle axis and tip in the ultrasound images with the proposed algorithm. The research work is hopeful to be used in the path planning and robot-assisted needle insertion procedures.

Suppressing voltage transients in high voltage power supplies

International Nuclear Information System (INIS)

Lickel, K.F.; Stonebank, R.

1979-01-01

A high voltage power supply for an X-ray tubes includes voltage adjusting means, a high voltage transformer, switch means connected to make and interrupt the primary current of the transformer, and over-voltage suppression means to suppress the voltage transient produced when the current is switched on. In order to reduce the power losses in the suppression means, an impedance is connected in the transformer primary circuit on operation of the switch means and is subsequently short-circuited by a switch controlled by a timer after a period which is automatically adjusted to the duration of the transient overvoltage. (U.K.)

1mN Electrospray Thruster with Safe Passive Propellant Delivery, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Busek proposes to develop a compact electrospray propulsion system with unprecedented capability. The 1500s Isp while requiring less than 45W of power. Compared with...

[Therapeutic effect observation of chronic knee joint pain assisted with the central-square needling technique of the thumb-tack needles].

Science.gov (United States)

Yang, Yang; Qi, Si; Liu, Mengyue; Zhao, Yu; Li, Ning

2017-10-12

To compare the differences in the clinical therapeutic effects on chronic knee joint pain between the combination of the central-square needling technique of thumb-tack needles with the routine therapy of acupuncture, moxibustion and tuina and the routine therapy of acupuncture, moxibustion and tuina . One hundred and twenty patients of chronic knee joint pain were randomized into an observation group and a control group, 60 cases in each one. In the control group, the routine therapy of acupuncture, moxibustion and tuina was adopted. In the observation group, at the end of treatment with the routine therapy of acupuncture, moxibustion and tuina , the subcutaneous embedding therapy was followed with four thumb-tack needles at the sites 1 to 1.5 cm above, below and bilateral to the main point ( ashi point) separately, and the needles were retained for 24 h to 48 h. The treatment was given once every two days, three times a week, totally 6 times in two weeks; and the follow-up visit was done for 3 months in patients of the two groups. The visual analogue scale (VAS) score before and after each treatment, Lequesne index score before treatment and at the end of follow-up and the case numbers of proactive use of painkillers or receiving acupuncture treatment in the follow-up stage were compared and observed in the patients of the two groups. The VAS score was reduced gradually after treatment in the patients of the two groups. The differences were significant statistically after the second treatment as compared with those before the treatment in the two groups (all P 0.05). In the follow-up stage, there were 0 case in the observation group and 9 cases in the control group in terms of proactive use of painkillers ( P 0.05). The acupuncture scheme in assistance with the central-square needling technique of thumb-tack needles obviously relieves chronic knee joint pain, much better sustains the analgesic effects of acupuncture and improves patient compliance.

Textiles: Some technocal information and data IV: sewability, sewing needles, threads and seams.

CSIR Research Space (South Africa)

Hunter, L

1979-09-01

Full Text Available half in about four c~ro"dd5 - - - - . . - - . Reducing the needle \\docity during its contact with the fabric can reduce needle temocratures bv about 50°C although other workers found the differences ;o be only 5 to IPC14. ~adiation plays a minor..., may have led to the confusion concerning the relative merits of different needle point30. Needle point shape does not appear to significantly affect maximum penetration force or energy~ expended while bulged-eye needles reduce heat build...

Origin of supercharging in electrospray ionization of noncovalent complexes from aqueous solution.

Science.gov (United States)

Sterling, Harry J; Williams, Evan R

2009-10-01

The use of m-nitrobenzyl alcohol (m-NBA) to enhance charging of noncovalent complexes formed by electrospray ionization from aqueous solutions was investigated. Addition of up to 1% m-NBA can result in a significant increase in the average charging of complexes, ranging from approximately 13% for the homo-heptamer of NtrC4-RC (317 kDa; maximum charge state increases from 42+ to 44+) to approximately 49% for myoglobin (17.6 kDa; maximum charge state increases from 9+ to 16+). Charge state distributions of larger complexes obtained from heated solutions to which no m-NBA was added are remarkably similar to those containing small amounts of m-NBA. Dissociation of the complexes through identical channels both upon addition of higher concentrations of m-NBA and heating is observed. These results indicate that the enhanced charging upon addition of m-NBA to aqueous electrospray solutions is a result of droplet heating owing to the high boiling point of m-NBA, which results in a change in the higher-order structure and/or dissociation of the complexes. For monomeric proteins and small complexes, the enhancement of charging is lower for heated aqueous solutions than from solutions with m-NBA because rapid folding of proteins from heated solutions that do not contain m-NBA can occur after the electrospray droplet is formed and is evaporatively cooled.

Initial experience with new dedicated needles for laparoscopic ultrasound-guided fine-needle aspiration and histological biopsies

DEFF Research Database (Denmark)

Mortensen, M B; Durup, J; Pless, T

2001-01-01

BACKGROUND AND STUDY AIMS: Laparoscopic ultrasonography (LUS) is an important imaging modality during laparoscopic staging of intra-abdominal malignancies, but LUS-assisted biopsy is often difficult or impossible. We report a newly developed inbuilt biopsy system for direct LUS-guided fine......-needle aspiration (FNA) and Tru-cut biopsies. PATIENTS AND METHODS: LUS-guided biopsy was performed in 20 patients with upper gastrointestinal tract tumors. The biopsied lesions had either not been previously detected by other imaging modalities or had been inaccessible, or the biopsy sample had been inadequate...... were good or acceptable in 18 patients (90%). Slight needle deviation (material was obtained, but pathological examination was impossible owing...

[Sleep disorder of schizophrenia treated with shallow needling: a randomized controlled trial].

Science.gov (United States)

Huang, Yanxi; Zheng, Ying

2015-09-01

To compare the clinical effective differences between shallow needling and medication for the sleep disorder of schizophrenia. Ninety-six patients with the sleep disorder of schizophrenia were randomly divided into a shallow needling group and a medication group, 48 cases in each one (one case dropping in the shallow needling group and two cases dropping in the medication group). The same dose paliperidone tablets were adopted in the two groups. In the shallow needling group, the main acupoints were Baihui (GV 20), Shangenxue (Extra) and Ezhongxian (MS 1), and the acupoints based on syndrome differentiation were selected. The shallow needling manipulation was used once a day, 5 times a week. In the medication group, 3 mg eszopiclone tablets were prescribed orally before sleep once every night. The patients were treated for 6 weeks in the two groups. Sleep condition was evaluated by Pittsburgh sleep quality index (PSQI) before and after treatment, and the clinical efficacy and the adverse reaction were assessed by positive and negative symptoms scale (PANSS) and treatment emergent symptom scale (TESS) before and after 2-week, 4-week and 6-week treatment. The clinical effects between the two groups were compared. After treatment in the two groups, both the total scores and the each factor score of the PSQI and the PANSS were apparently decreased (Pshallow needling group was reduced more obviously than that of the medication group (Pshallow needling group (Pshallow needling group was better than that in the medication group after treatment (Pshallow needling group after treatment (P0. 05). At the end of the 6th week, the curative and effective rate was 63. 9% (30/47) and the total effective rate was 95. 8% (45/47) in the shallow needling group;the curative and effective rate was 58. 7% (27/46) and the total effective rate was 91. 3% (42/46) in the medication group. The difference of the effect was not statistically significant between the two groups (P>0. 05). The

A comparison of epicuticular wax of Pinus sylvestris needles from three sites in Ireland

International Nuclear Information System (INIS)

Donnelly, A.; Dowding, P.

1994-01-01

Three forest stands of Pinus sylvestris were chosen for comparison in Ireland. Needles from three year classes were collected. Cuticular transpiration curves showed that the rate of water loss from 1-year-old needles was faster than either 2-year-old or current-year needles at all sites. The amount of epicuticular wax extracted was similar to that reported in the literature. Needle wettability increased with needle age. Amorphous wax coverage was estimated using scanning electron microscopy (SEM) and was found to increase with needle age. Algal cells were noted on needles of all ages at one site and appeared to affect transpiration and microroughness. The presence of fungal hyphae was also noted. (orig.)

EUS-Guided Needle-Based Confocal Laser Endomicroscopy

DEFF Research Database (Denmark)

Bhutani, Manoop S; Koduru, Pramoda; Joshi, Virendra

2015-01-01

Endoscopic ultrasound (EUS) has emerged as an excellent tool for imaging the gastrointestinal tract, as well as surrounding structures. EUS-guided fine-needle aspiration (EUS-FNA) has become the standard of care for the tissue sampling of a variety of masses and lymph nodes within and around...... the gut, providing further diagnostic and staging information. Confocal laser endomicroscopy (CLE) is a novel endoscopic method that enables imaging at a subcellular level of resolution during endoscopy, allowing up to 1000-fold magnification of tissue and providing an optical biopsy. A new procedure...... that has been developed in the past few years is needle-based confocal laser endomicroscopy (nCLE), which involves a mini-CLE probe that can be passed through a 1 9-gauge needle during EUS-FNA. This enables the real-time visualization of tissue at a microscopic level, with the potential to further improve...

Achievement of needle-like focus by engineering radial-variant vector fields.

Science.gov (United States)

Gu, Bing; Wu, Jia-Lu; Pan, Yang; Cui, Yiping

2013-12-16

We present and demonstrate a novel method for engineering the radial-variant polarization on the incident field to achieve a needle of transversally polarized field without any pupil filters. We generate a new kind of localized linearly-polarized vector fields with distributions of states of polarization (SoPs) describing by the radius to the power p and explore its tight focusing, nonparaxial focusing, and paraxial focusing properties. By tuning the power p, we obtain the needle-like focal field with hybrid SoPs and give the formula for describing the length of the needle. Experimentally, we systematically investigate both the intensity distributions and the polarization evolution of the optical needle by paraxial focusing the generated vector field. Such an optical needle, which enhances the light-matter interaction, has intriguing applications in optical microma-chining and nonlinear optics.

Knowledge, attitude and practices about needle stick injuries in health care workers

International Nuclear Information System (INIS)

Waqar, S.H.; Siraj, M.U.; Razzaq, Z.; Malik, Z.I.; Zahid, M.A.

2011-01-01

Objectives: To assess knowledge, attitude and practices about needle stick Injuries in health care workers. Study type, settings and duration: Hospital based study carried out at Pakistan Institute of Medical Sciences, Islamabad, from August 2010 to November 2010. Subjects and Methods: A self administered 19 items questionnaire was prepared which contained information about needle stick injuries, its awareness, frequency of injury and the protocols that were followed after an injury had occurred. These questionnaires were given to 500 health care workers working in different wards and theaters of the hospital after obtaining their informed written consent. The health care workers included doctors, nurses and paramedical staff of Pakistan Institute of Medical Sciences, Islamabad. The data was entered and analyzed using SPSS version 15. Results: A total of 500 health care workers filled the questionnaire and returned it. Out of these 416(83.2%) reported ever experiencing needle stick injuries in their professional life. Health care workers working in Emergency department were most frequently affected (65%) followed by those working in different wards (27%) and operation theatre (8%). Most (93.6%) workers had knowledge about needle stick injuries and only 6.4% were not aware of it. Needle stick injury occurred from a brand new (unused) syringe in 51.2% cases, while in 32.8% cases, the needle caused an injury after it had been used for an injection. In 5% cases, injury occurred with blood stained needles. The commonest reasons for needle injury in stick injuries were heavy work load (36.8%) followed by hasty work (33.6%) and needle recapping (18.6%). About 66% health care workers were already vaccinated against hepatitis B. Only 13% workers followed universal guidelines of needle stick injuries and no case was reported to hospital authorities. Conclusions: Health care workers had inadequate knowledge about the risk associated with needle stick injuries and do not

Evaluating the advances and use of hypodermic needles in dentistry.

Science.gov (United States)

Boynes, Sean G

2014-10-01

Different injection techniques and patient management methodologies have been proposed to decrease the fear patients may have concerning dental needles. Dental providers should have an understanding of the technological advances, changes in techniques, and patient perceptions associated with the hypodermic needle. This article provides an overview of the pain perception process associated with dental injections. It reviews the two main sensory nerve fibers associated with injection pain and discusses needle properties as well as complications and adverse occurrences.

Development of Needle Insertion Manipulator for Central Venous Catheterization

Science.gov (United States)

Kobayashi, Yo; Hong, Jaesung; Hamano, Ryutaro; Hashizume, Makoto; Okada, Kaoru; Fujie, Masakatsu G.

Central venous catheterization is a procedure, which a doctor insert a catheter into the patient’s vein for transfusion. Since there are risks of bleeding from arterial puncture or pneumothorax from pleural puncture. Physicians are strictly required to make needle reach up into the vein and to stop the needle in the middle of vein. We proposed a robot system for assisting the venous puncture, which can relieve the difficulties in conventional procedure, and the risks of complication. This paper reports the design structuring and experimental results of needle insertion manipulator. First, we investigated the relationship between insertion force and angle into the vein. The results indicated that the judgment of perforation using the reaction force is possible in case where the needling angle is from 10 to 20 degree. The experiment to evaluate accuracy of the robot also revealed that it has beyond 0.5 mm accuracy. We also evaluated the positioning accuracy in the ultrasound images. The results displays that the accuracy is beyond 1.0 mm and it has enough for venous puncture. We also carried out the venous puncture experiment to the phantom and confirm our manipulator realized to make needle reach up into the vein.

Patients’ Knowledge of and Practices Relating to the Disposal of Used Insulin Needles

Directory of Open Access Journals (Sweden)

Kerri T. Musselman, PharmD

2010-01-01

Full Text Available Objective: To determine (1 how patients currently dispose of used insulin needles, (2 whether patients were educated about disposal of their used insulin needles, and (3 who educated patients about the disposal of their used insulin needles.Methods: A self-administered questionnaire was designed for this study. The survey assessed patient knowledge about disposal of used insulin needles and the patient-reported source and location of education about disposal techniques. The questionnaire was administered to a convenience sample of patients from four locations in Richmond, Virginia. Any patient who used insulin, was at least 18 years old, and was willing to complete the survey was eligible for inclusion.Results: Fifty responses were received with 40% indicating that education had been received on the disposal of used needles. From that 40%, nurses were identified as the source of education 60% of the time and pharmacists 25% of the time. Approximately 50% of the respondents reported disposing of used needles directly in the trash when at home. While away from home, 22% reported placing used needles in the trash, and 38% took them home for disposal.Conclusion: Patients are not consistently educated regarding the proper disposal of used needles. Health care practitioners should play a larger role in educating patients about the potential risks of inappropriate needle disposal and appropriate disposal methods. Future research is still needed to understand fully the magnitude of the problems associated with inappropriate needle disposal by patients.

Teleoperation of steerable flexible needles by combining kinesthetic and vibratory feedback.

Science.gov (United States)

Pacchierotti, Claudio; Abayazid, Momen; Misra, Sarthak; Prattichizzo, Domenico

2014-01-01

Needle insertion in soft-tissue is a minimally invasive surgical procedure that demands high accuracy. In this respect, robotic systems with autonomous control algorithms have been exploited as the main tool to achieve high accuracy and reliability. However, for reasons of safety and responsibility, autonomous robotic control is often not desirable. Therefore, it is necessary to focus also on techniques enabling clinicians to directly control the motion of the surgical tools. In this work, we address that challenge and present a novel teleoperated robotic system able to steer flexible needles. The proposed system tracks the position of the needle using an ultrasound imaging system and computes needle's ideal position and orientation to reach a given target. The master haptic interface then provides the clinician with mixed kinesthetic-vibratory navigation cues to guide the needle toward the computed ideal position and orientation. Twenty participants carried out an experiment of teleoperated needle insertion into a soft-tissue phantom, considering four different experimental conditions. Participants were provided with either mixed kinesthetic-vibratory feedback or mixed kinesthetic-visual feedback. Moreover, we considered two different ways of computing ideal position and orientation of the needle: with or without set-points. Vibratory feedback was found more effective than visual feedback in conveying navigation cues, with a mean targeting error of 0.72 mm when using set-points, and of 1.10 mm without set-points.

Robotic Needle Guide for Prostate Brachytherapy: Clinical Testing of Feasibility and Performance

Science.gov (United States)

Song, Danny Y; Burdette, Everette C; Fiene, Jonathan; Armour, Elwood; Kronreif, Gernot; Deguet, Anton; Zhang, Zhe; Iordachita, Iulian; Fichtinger, Gabor; Kazanzides, Peter

2010-01-01

Purpose Optimization of prostate brachytherapy is constrained by tissue deflection of needles and fixed spacing of template holes. We developed and clinically tested a robotic guide towards the goal of allowing greater freedom of needle placement. Methods and Materials The robot consists of a small tubular needle guide attached to a robotically controlled arm. The apparatus is mounted and calibrated to operate in the same coordinate frame as a standard template. Translation in x and y directions over the perineum ±40mm are possible. Needle insertion is performed manually. Results Five patients were treated in an IRB-approved study. Confirmatory measurements of robotic movements for initial 3 patients using infrared tracking showed mean error of 0.489 mm (SD 0.328 mm). Fine adjustments in needle positioning were possible when tissue deflection was encountered; adjustments were performed in 54/179 (30.2%) needles placed, with 36/179 (20.1%) adjustments of > 2mm. Twenty-seven insertions were intentionally altered to positions between the standard template grid to improve the dosimetric plan or avoid structures such as pubic bone and blood vessels. Conclusions Robotic needle positioning provided a means of compensating for needle deflections as well as the ability to intentionally place needles into areas between the standard template holes. To our knowledge, these results represent the first clinical testing of such a system. Future work will be incorporation of direct control of the robot by the physician, adding software algorithms to help avoid robot collisions with the ultrasound, and testing the angulation capability in the clinical setting. PMID:20729152

Study on design and cutting parameters of rotating needles for core biopsy.

Science.gov (United States)

Giovannini, Marco; Ren, Huaqing; Cao, Jian; Ehmann, Kornel

2018-06-15

Core needle biopsies are widely adopted medical procedures that consist in the removal of biological tissue to better identify a lesion or an abnormality observed through a physical exam or a radiology scan. These procedures can provide significantly more information than most medical tests and they are usually performed on bone lesions, breast masses, lymph nodes and the prostate. The quality of the samples mainly depends on the forces exerted by the needle during the cutting process. The reduction of these forces is critical to extract high-quality tissue samples. The most critical factors that affect the cutting forces are the geometry of the needle tip and its motion while it is penetrating the tissue. However, optimal needle tip configurations and cutting parameters are not well established for rotating insertions. In this paper, the geometry and cutting forces of hollow needles are investigated. The fundamental goal of this study is to provide a series of guidelines for clinicians and surgeons to properly select the optimal tip geometries and speeds. Analytical models related to the cutting angles of several needle tip designs are presented and compared. Several needle tip geometries were manufactured from a 14-gauge cannula, commonly adopted during breast biopsies. The needles were then tested at different speeds and on different phantom tissues. According to these experimental measurements recommendations were formulated for rotating needle insertions. The findings of this study can be applied and extended to several biopsy procedures in which a cannula is used to extract tissue samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Screening of acetylcholinesterase inhibitors in snake venom by electrospray mass spectrometry

NARCIS (Netherlands)

Liesener, A.; Perchuc, Anna-Maria; Schöni, Reto; Schebb, Nils Helge; Wilmer, Marianne; Karst, U.

2007-01-01

An electrospray ionization/mass spectrometry (ESI/MS)-based assay for the determination of acetylcholinesterase (AChE)-inhibiting activity in snake venom was developed. It allows the direct monitoring of the natural AChE substrate acetylcholine (AC) and the respective product choline. The assay

Spinal anaesthesia in young patients: evaluation of needle gauge ...

African Journals Online (AJOL)

Background:The well-known complication of spinal anaesthesia, postdural puncture headache (PDPH), is especially troublesome in young patients. The needle gauge and configuration of needle tip appear to be the important factors in reducing the incidence of PDPH; however it may increase the incidence of technical ...

Effects of insertion speed and trocar stiffness on the accuracy of needle position for brachytherapy

Energy Technology Data Exchange (ETDEWEB)

McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J. [Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, State College, Pennsylvania 16802 (United States); Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Biomedical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 and Mechanical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2012-04-15

Purpose: In prostate brachytherapy, accurate positioning of the needle tip to place radioactive seeds at its target site is critical for successful radiation treatment. During the procedure, needle deflection leads to seed misplacement and suboptimal radiation dose to cancerous cells. In practice, radiation oncologists commonly use high-speed hand needle insertion to minimize displacement of the prostate as well as the needle deflection. Effects of speed during needle insertion and stiffness of trocar (a solid rod inside the hollow cannula) on needle deflection are studied. Methods: Needle insertion experiments into phantom were performed using a 2{sup 2} factorial design (2 parameters at 2 levels), with each condition having replicates. Analysis of the deflection data included calculating the average, standard deviation, and analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: The stiffer tungsten carbide trocar is effective in reducing the average and standard deviation of needle deflection. The fast insertion speed together with the stiffer trocar generated the smallest average and standard deviation for needle deflection for almost all cases. Conclusions: The combination of stiff tungsten carbide trocar and fast needle insertion speed are important to decreasing needle deflection. The knowledge gained from this study can be used to improve the accuracy of needle insertion during brachytherapy procedures.

Voltage-dependent gating in a "voltage sensor-less" ion channel.

Directory of Open Access Journals (Sweden)

Harley T Kurata

2010-02-01

Full Text Available The voltage sensitivity of voltage-gated cation channels is primarily attributed to conformational changes of a four transmembrane segment voltage-sensing domain, conserved across many levels of biological complexity. We have identified a remarkable point mutation that confers significant voltage dependence to Kir6.2, a ligand-gated channel that lacks any canonical voltage-sensing domain. Similar to voltage-dependent Kv channels, the Kir6.2[L157E] mutant exhibits time-dependent activation upon membrane depolarization, resulting in an outwardly rectifying current-voltage relationship. This voltage dependence is convergent with the intrinsic ligand-dependent gating mechanisms of Kir6.2, since increasing the membrane PIP2 content saturates Po and eliminates voltage dependence, whereas voltage activation is more dramatic when channel Po is reduced by application of ATP or poly-lysine. These experiments thus demonstrate an inherent voltage dependence of gating in a "ligand-gated" K+ channel, and thereby provide a new view of voltage-dependent gating mechanisms in ion channels. Most interestingly, the voltage- and ligand-dependent gating of Kir6.2[L157E] is highly sensitive to intracellular [K+], indicating an interaction between ion permeation and gating. While these two key features of channel function are classically dealt with separately, the results provide a framework for understanding their interaction, which is likely to be a general, if latent, feature of the superfamily of cation channels.

Characterization of cationic glycoporphyrins by electrospray tandem mass spectrometry.

Science.gov (United States)

Silva, Eduarda M P; Serra, Vanda Vaz; Ribeiro, Anderson O; Tomé, João P C; Domingues, Pedro; Faustino, M Amparo F; Neves, M Graça P M S; Tomé, Augusto C; Cavaleiro, José A S; Ferrer-Correia, António J; Iamamoto, Yassuko; Domingues, M Rosário M

2006-01-01

Novel cationic porphyrin derivatives having a galactose or a bis(isopropylidene)galactose unit linked directly to a pyridine or to an aminophenyl group were characterized by electrospray tandem mass spectrometry (ESI-MS/MS). The electrospray mass spectra (ESI-MS) show the M(+) ions, since these porphyrins are already monocharged in solution. The fragmentation of these ions under ESI-MS/MS conditions was studied and it was found that elimination of the sugar residue as a radical (-163 or -243 Da) is a common fragmentation pathway. Loss of the sugar unit as a neutral fragment (-162 or -242 Da) and cross-ring fragmentations typical of glyco-derivatives are also observed for the pyridinium glycoporphyrins, but they are absent in the case of ammonium glycoporphyrins. The cationic beta-pyridiniumvinyl porphyrins show an atypical fragmentation due to the cleavage of the C(5)-C(6) bond of the sugar unit. Overall, the different patterns of fragmentation observed in the ESI-MS/MS spectra of the sugar pyridinium porphyrins and of the sugar ammonium phenyl porphyrins can give important information about the type of spacer between the porphyrin and the sugar unit. Copyright (c) 2006 John Wiley & Sons, Ltd.

A novel fabrication method of silicon nano-needles using MEMS TMAH etching techniques

International Nuclear Information System (INIS)

Yan Sheping; Xu Yang; Yang Junyi; Wang Huiquan; Jin Zhonghe; Wang Yuelin

2011-01-01

Nano-needles play important roles in nanoscale operations. However, current nano-needle fabrication is usually expensive and controling the sizes and angles is complicated. We have developed a simple and low cost silicon nano-needle fabrication method using traditional microelectromechanical system (MEMS) tetramethyl ammonium hydroxide (TMAH) etching techniques. We take advantage of the fact that the decrease of the silicon etch rate in TMAH solutions exhibits an inverse fourth power dependence on the boron doping concentration in our nano-needle fabrication. Silicon nano-needles, with high aspect ratio and sharp angles θ as small as 2.9 deg., are obtained, which could be used for bio-sensors and nano-handling procedures, such as penetrating living cells. An analytic model is proposed to explain the etching evolution of the experimental results, which is used to predict the needle angle, length, and etching time. Based on our method, nano-needles with small acute angle θ can be obtained.

Transient voltage sharing in series-coupled high voltage switches

Directory of Open Access Journals (Sweden)

Editorial Office

1992-07-01

Full Text Available For switching voltages in excess of the maximum blocking voltage of a switching element (for example, thyristor, MOSFET or bipolar transistor such elements are often coupled in series - and additional circuitry has to be provided to ensure equal voltage sharing. Between each such series element and system ground there is a certain parasitic capacitance that may draw a significant current during high-speed voltage transients. The "open" switch is modelled as a ladder network. Analy­sis reveals an exponential progression in the distribution of the applied voltage across the elements. Overstressing thus oc­curs in some of the elements at levels of the total voltage that are significantly below the design value. This difficulty is overcome by grading the voltage sharing circuitry, coupled in parallel with each element, in a prescribed manner, as set out here.

Lumbar punction: comparison between an atraumatic and a traumatic punction needle

Directory of Open Access Journals (Sweden)

Tina Bregant

2017-03-01

Full Text Available Background: Lumbar puncture is a standardized, routine diagnostic procedure in the diagnosis of neurological diseases. Post-duarl puncture headache (PDPH is a common complication which occurs in 10 to 30 % of patients. Although the incidence of PDPH is much lower with the use of small, non-cutting needles, neurologists in Slovenia routinely use the classical traumatic spinal needles.Methods: In the article we provide an overview of a research concerned with the use of traumatic and atraumatic needles in the procedure with the emphasis on complications of the lumbar puncture. We present American and European recommendations for lumbar puncture procedure.Conclusions: International recommendations for neurologists advise the use of atraumatic spinal needles for lumbar puncture. We recommend to Slovenian neurologists to start using the atraumatic needles for elective lumbar punctures and hence provide neurological patients with better quality and cheaper long-term care.

Prevalence of Needle Stick Injuries among Healthcare Workers in ...

African Journals Online (AJOL)

Background: Needle stick injuries represent one of the most important occupational hazards to which health workers are exposed. These injuries result from accidental piercing of the skin and or mucous membranes by sharp objects. Needle stick injuries carry the risk of exposure to blood-borne pathogens, especially ...

Diagnosis Of Thyroid Enlargement: Use Of Fine Needle Aspiration ...

African Journals Online (AJOL)

One hundred and ten Fine Needle Aspiration Biopsies (FNAC) obtained from 87 patients with thyroid enlargement or nodules were retrospectively reviewed. Aspiration biopsy was accomplished using 21-gauge needle attached with 20-ml plastic syringe. There were 14 males and 73 females involved in the study. Sixty- four ...

Power conditioning using dynamic voltage restorers under different voltage sag types.

Science.gov (United States)

Saeed, Ahmed M; Abdel Aleem, Shady H E; Ibrahim, Ahmed M; Balci, Murat E; El-Zahab, Essam E A

2016-01-01

Voltage sags can be symmetrical or unsymmetrical depending on the causes of the sag. At the present time, one of the most common procedures for mitigating voltage sags is by the use of dynamic voltage restorers (DVRs). By definition, a DVR is a controlled voltage source inserted between the network and a sensitive load through a booster transformer injecting voltage into the network in order to correct any disturbance affecting a sensitive load voltage. In this paper, modelling of DVR for voltage correction using MatLab software is presented. The performance of the device under different voltage sag types is described, where the voltage sag types are introduced using the different types of short-circuit faults included in the environment of the MatLab/Simulink package. The robustness of the proposed device is evaluated using the common voltage sag indices, while taking into account voltage and current unbalance percentages, where maintaining the total harmonic distortion percentage of the load voltage within a specified range is desired. Finally, several simulation results are shown in order to highlight that the DVR is capable of effective correction of the voltage sag while minimizing the grid voltage unbalance and distortion, regardless of the fault type.

Automatic Multiple-Needle Surgical Planning of Robotic-Assisted Microwave Coagulation in Large Liver Tumor Therapy.

Directory of Open Access Journals (Sweden)

Shaoli Liu

Full Text Available The "robotic-assisted liver tumor coagulation therapy" (RALTCT system is a promising candidate for large liver tumor treatment in terms of accuracy and speed. A prerequisite for effective therapy is accurate surgical planning. However, it is difficult for the surgeon to perform surgical planning manually due to the difficulties associated with robot-assisted large liver tumor therapy. These main difficulties include the following aspects: (1 multiple needles are needed to destroy the entire tumor, (2 the insertion trajectories of the needles should avoid the ribs, blood vessels, and other tissues and organs in the abdominal cavity, (3 the placement of multiple needles should avoid interference with each other, (4 an inserted needle will cause some deformation of liver, which will result in changes in subsequently inserted needles' operating environment, and (5 the multiple needle-insertion trajectories should be consistent with the needle-driven robot's movement characteristics. Thus, an effective multiple-needle surgical planning procedure is needed. To overcome these problems, we present an automatic multiple-needle surgical planning of optimal insertion trajectories to the targets, based on a mathematical description of all relevant structure surfaces. The method determines the analytical expression of boundaries of every needle "collision-free reachable workspace" (CFRW, which are the feasible insertion zones based on several constraints. Then, the optimal needle insertion trajectory within the optimization criteria will be chosen in the needle CFRW automatically. Also, the results can be visualized with our navigation system. In the simulation experiment, three needle-insertion trajectories were obtained successfully. In the in vitro experiment, the robot successfully achieved insertion of multiple needles. The proposed automatic multiple-needle surgical planning can improve the efficiency and safety of robot-assisted large liver tumor

Automatic Multiple-Needle Surgical Planning of Robotic-Assisted Microwave Coagulation in Large Liver Tumor Therapy.

Science.gov (United States)

Liu, Shaoli; Xia, Zeyang; Liu, Jianhua; Xu, Jing; Ren, He; Lu, Tong; Yang, Xiangdong

2016-01-01

The "robotic-assisted liver tumor coagulation therapy" (RALTCT) system is a promising candidate for large liver tumor treatment in terms of accuracy and speed. A prerequisite for effective therapy is accurate surgical planning. However, it is difficult for the surgeon to perform surgical planning manually due to the difficulties associated with robot-assisted large liver tumor therapy. These main difficulties include the following aspects: (1) multiple needles are needed to destroy the entire tumor, (2) the insertion trajectories of the needles should avoid the ribs, blood vessels, and other tissues and organs in the abdominal cavity, (3) the placement of multiple needles should avoid interference with each other, (4) an inserted needle will cause some deformation of liver, which will result in changes in subsequently inserted needles' operating environment, and (5) the multiple needle-insertion trajectories should be consistent with the needle-driven robot's movement characteristics. Thus, an effective multiple-needle surgical planning procedure is needed. To overcome these problems, we present an automatic multiple-needle surgical planning of optimal insertion trajectories to the targets, based on a mathematical description of all relevant structure surfaces. The method determines the analytical expression of boundaries of every needle "collision-free reachable workspace" (CFRW), which are the feasible insertion zones based on several constraints. Then, the optimal needle insertion trajectory within the optimization criteria will be chosen in the needle CFRW automatically. Also, the results can be visualized with our navigation system. In the simulation experiment, three needle-insertion trajectories were obtained successfully. In the in vitro experiment, the robot successfully achieved insertion of multiple needles. The proposed automatic multiple-needle surgical planning can improve the efficiency and safety of robot-assisted large liver tumor therapy

Needle Biopsy of the Lung

Science.gov (United States)

... clip. The needle is hollow so it can capture the tissue specimen. There are several types of ... breath, difficulty in catching your breath, rapid pulse (heart rate), sharp chest or shoulder pain with breathing, ...

Assessment of bone biopsy needles for sample size, specimen quality and ease of use

International Nuclear Information System (INIS)

Roberts, C.C.; Liu, P.T.; Morrison, W.B.; Leslie, K.O.; Carrino, J.A.; Lozevski, J.L.

2005-01-01

To assess whether there are significant differences in ease of use and quality of samples among several bone biopsy needles currently available. Eight commonly used, commercially available bone biopsy needles of different gauges were evaluated. Each needle was used to obtain five consecutive samples from a lamb lumbar pedicle. Subjective assessment of ease of needle use, ease of sample removal from the needle and sample quality, before and after fixation, was graded on a 5-point scale. The number of attempts necessary to reach a 1 cm depth was recorded. Each biopsy specimen was measured in the gross state and after fixation. The RADI Bonopty 15 g and Kendall Monoject J-type 11 g needles were rated the easiest to use, while the Parallax Core-Assure 11 g and the Bard Ostycut 16 g were rated the most difficult. Parallax Core-Assure and Kendall Monoject needles had the highest quality specimen in the gross state; Cook Elson/Ackerman 14 g and Bard Ostycut 16 g needles yielded the lowest. The MD Tech without Trap-Lok 11 g needle had the highest quality core after fixation, while the Bard Ostycut 16 g had the lowest. There was a significant difference in pre-fixation sample length between needles (P<0.0001), despite acquiring all cores to a standard 1 cm depth. Core length and width decrease in size by an average of 28% and 42% after fixation. Bone biopsy needles vary significantly in performance. Detailed knowledge of the strengths and weaknesses of different needles is important to make an appropriate selection for each individual's practice. (orig.)

Percutaneous image-guided needle biopsy in children - summary of our experience with 57 children

International Nuclear Information System (INIS)

Sklair-Levy, M.; Lebensart, P.D.; Applbaum, Y.H.; Bar-Ziv, J.; Libson, E.; Ramu, N.; Freeman, A.; Gozal, D.; Gross, E.; Sherman, Y.

2001-01-01

Background: Percutaneous image-guided needle biopsy in children has been slower to gain acceptance than in adults where it is regarded as the standard clinical practice in screening suspicious masses. Objectives: To report our experience with percutaneous image-guided needle biopsy in the pediatric population and assess its clinical use, efficacy and limitations. Material and methods: Sixty-nine percutaneous image-guided needle biopsies were performed in 57 children. The age of the children ranged from 4 days to 14 years (mean 5.6 years). We used 16- to-20-gauge cutting-edge needles. Sixty-two biopsies were core-needle biopsies and 7 fine-needle aspiration biopsies. Results: There were 50 malignant lesions, 10 benign lesions and 2 infectious lesions. In 55 (88.7 %) lesions the needle biopsy was diagnostic. In 7 (11.3 %) the biopsy was non-diagnostic and the diagnosis was made by surgery. Core-needle biopsy was diagnostic in 47 of 50 (94 %) of the malignant solid tumors. In 3 out of 5 children with lymphoma, an accurate diagnosis was obtained with needle aspiration. Seven children underwent a repeated core-needle biopsy, (5 for Wilms' tumor and 2 for neuroblastoma) that was diagnostic in all cases. All the biopsies were performed without complications. Conclusion: Percutaneous image-guided needle biopsy is a simple, minimally invasive, safe and accurate method for the evaluation of children with suspicious masses. These data suggest that image-guided needle biopsy is an excellent tool for diagnosing solid tumors in the pediatric population. Negative studies should be considered nondiagnostic and followed by excisional surgical biopsies when clinical suspicion of malignancy is high. (orig.)

Fiber Bragg gratings-based sensing for real-time needle tracking during MR-guided brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Borot de Battisti, Maxence, E-mail: M.E.P.Borot@umcutrecht.nl; Maenhout, Metha; Lagendijk, Jan J. W.; Vulpen, Marco van; Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, Utrecht 3584 CX (Netherlands); Denis de Senneville, Baudouin [Imaging Division, University Medical Center Utrecht, Heidelberglaan 100, Utrecht 3584 CX, The Netherlands and IMB, UMR 5251 CNRS/University of Bordeaux, Talence 33400 (France); Hautvast, Gilion; Binnekamp, Dirk [Philips Group Innovation Biomedical Systems, Eindhoven 5656 AE (Netherlands)

2016-10-15

Purpose: The development of MR-guided high dose rate (HDR) brachytherapy is under investigation due to the excellent tumor and organs at risk visualization of MRI. However, MR-based localization of needles (including catheters or tubes) has inherently a low update rate and the required image interpretation can be hampered by signal voids arising from blood vessels or calcifications limiting the precision of the needle guidance and reconstruction. In this paper, a new needle tracking prototype is investigated using fiber Bragg gratings (FBG)-based sensing: this prototype involves a MR-compatible stylet composed of three optic fibers with nine sets of embedded FBG sensors each. This stylet can be inserted into brachytherapy needles and allows a fast measurement of the needle deflection. This study aims to assess the potential of FBG-based sensing for real-time needle (including catheter or tube) tracking during MR-guided intervention. Methods: First, the MR compatibility of FBG-based sensing and its accuracy was evaluated. Different known needle deflections were measured using FBG-based sensing during simultaneous MR-imaging. Then, a needle tracking procedure using FBG-based sensing was proposed. This procedure involved a MR-based calibration of the FBG-based system performed prior to the interventional procedure. The needle tracking system was assessed in an experiment with a moving phantom during MR imaging. The FBG-based system was quantified by comparing the gold-standard shapes, the shape manually segmented on MRI and the FBG-based measurements. Results: The evaluation of the MR compatibility of FBG-based sensing and its accuracy shows that the needle deflection could be measured with an accuracy of 0.27 mm on average. Besides, the FBG-based measurements were comparable to the uncertainty of MR-based measurements estimated at half the voxel size in the MR image. Finally, the mean(standard deviation) Euclidean distance between MR- and FBG-based needle position

Mitigation of voltage sags in the distribution system with dynamic voltage restorer

International Nuclear Information System (INIS)

Viglas, D.; Belan, A.

2012-01-01

Dynamic voltage restorer is a custom power device that is used to improve voltage sags or swells in electrical distribution system. The components of the Dynamic Voltage Restorer consist of injection transformers, voltage source inverter, passive filters and energy storage. The main function of the Dynamic voltage restorer is used to inject three phase voltage in series and in synchronism with the grid voltages in order to compensate voltage disturbances. This article deals with mitigation of voltage sags caused by three-phase short circuit. Dynamic voltage restorer is modelled in MATLAB/Simulink. (Authors)

A fragmentation study of kaempferol using electrospray quadrupole time-of-flight mass spectrometry at high mass resolution

Science.gov (United States)

March, Raymond E.; Miao, Xiu-Sheng

2004-02-01

A mass spectrometric method based on the combined use of electrospray ionization, collision-induced dissociation and tandem mass spectrometry at high mass resolution has been applied to an investigation of the structural characterization of protonated and deprotonated kaempferol (3,5,7,4'-tetrahydroxyflavone). Low-energy product ion mass spectra of [M+H]+ ions showed simple fragmentations of the C ring that permitted characterization of the substituents in the A and B rings. In addition, four rearrangement reactions accompanied by losses of C2H2O, CHO[radical sign], CO, and H2O were observed. Low-energy product ion mass spectra of [M-H]- ions showed only four rearrangement reactions accompanied by losses of OH[radical sign], CO, CH2O, and C2H2O. The use of elevated cone voltages permitted observation of product ion mass spectra of selected primary and secondary fragment ions so that each fragment ion reported was observed as a direct product of its immediate precursor ion. Product ion mass spectra examined at high mass resolution allowed unambiguous determination of the elemental composition of fragment ions and resolution of two pairs of isobars. Fragmentation mechanisms and ion structures have been proposed.

Accumulation of Cs 137 by needles of pinus silvestris in various types of forest

International Nuclear Information System (INIS)

Golushko, R.M.

2002-01-01

It is researched accumulation of Cs 137 by needles of pine trees during growing old. It is shown, that needles of the one year old have more high radioactivity than needles of the two or three years old. Needles of pine trees accumulated more Cs 137 on good wet soils

Fertilization Changes Chemical Defense in Needles of Mature Norway Spruce (Picea abies

Directory of Open Access Journals (Sweden)

Line Nybakken

2018-06-01

Full Text Available Nitrogen availability limits growth in most boreal forests. However, parts of the boreal zone receive significant levels of nitrogen deposition. At the same time, forests are fertilized to increase volume growth and carbon sequestration. No matter the source, increasing nitrogen in the boreal forest ecosystem will influence the resource situation for its primary producers, the plants, with possible implications for their defensive chemistry. In general, fertilization reduces phenolic compound concentrations in trees, but existing evidence mainly comes from studies on young plants. Given the role of the phenolic compounds in protection against herbivores and other forest pests, it is important to know if phenolics are reduced with fertilization also in mature trees. The evergreen Norway spruce is long-lived, and it is reasonable that defensive strategies could change from the juvenile to the reproductive and mature phases. In addition, as the needles are kept for several years, defense could also change with needle age. We sampled current and previous year needles from an N fertilization experiment in a Norway spruce forest landscape in south-central Norway to which N had been added annually for 13 years. We analyzed total nitrogen (N and carbon (C, as well as low-molecular phenolics and condensed tannins. Needles from fertilized trees had higher N than those from controls plots, and fertilization decreased concentrations of many flavonoids, as well as condensed tannins in current year needles. In previous year needles, some stilbenes and condensed tannins were higher in fertilized trees. In control trees, the total phenolic concentration was almost five times as high in previous year needles compared with those from the current year, and there were great compositional differences. Previous year needles contained highest concentrations of acetophenone and stilbenes, while in the current year needles the flavonoids, and especially coumaroyl

Comparison of Fine Needle Aspiration and Fine Needle Nonaspiration Cytology of Thyroid Nodules: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Hongming Song

2015-01-01

Full Text Available Background. Fine needle aspiration cytology (FNAC and fine needle nonaspiration cytology (FNNAC are useful cost-effective techniques for preoperatively assessing thyroid lesions. Both techniques have advantages and disadvantages, and there is controversy over which method is superior. This meta-analysis was performed to evaluate the differences between FNAC and FNNAC for diagnosis of thyroid nodules. Methods. Primary publications were independently collected by two reviewers from PubMed, Web of Science, Google Scholar, EBSCO, OALib, and the Cochrane Library databases. The following search terms were used: fine needle, aspiration, capillary, nonaspiration, sampling without aspiration, thyroid, and cytology. The last search was performed on February 1, 2015. Results. Sixteen studies comprising 1,842 patients and 2,221 samples were included in this study. No statistically significant difference was observed between FNAC and FNNAC groups with respect to diagnostically inadequate smears, diagnostically superior smears, diagnostic performance (accuracy, sensitivity, specificity, negative predictive value, and positive predictive value, area under the summary receiver operating characteristic curve, average score of each parameter (background blood or clot, amount of cellular material, degree of cellular degeneration, degree of cellular trauma, and retention of appropriate architecture, and total score of five parameters. Conclusion. FNAC and FNNAC are equally useful in assessing thyroid nodules.

Fabrication and optical characterization of cadmium sulfide needles using nuclear track membrane

International Nuclear Information System (INIS)

Peng, L.Q.; Wang, S.C.; Ju, X.; Xiao, H.; Chen, H.; He, Y.J.

1999-01-01

Cadmium sulfide needles with a diameter of 0.2 μm have been fabricated in nuclear track polyethylene-terephthalate (PET) membrane by electrochemically depositing from organic solvent dimethylsulfoxide (DMSO) containing CdCl 2 and elemental sulfur at the temperature 110 deg. C. The characterization of the sample of CdS needles was studied by scanning electron microscope, X-ray diffraction, absorption and photoluminescence spectra. The optical experiments show that in the sample of CdS needles there is an absorption peak that could be assigned to the interface states of the CdS needles

Fabrication and optical characterization of cadmium sulfide needles using nuclear track membrane

Energy Technology Data Exchange (ETDEWEB)

Peng, L.Q.; Wang, S.C.; Ju, X.; Xiao, H.; Chen, H.; He, Y.J

1999-06-01

Cadmium sulfide needles with a diameter of 0.2 {mu}m have been fabricated in nuclear track polyethylene-terephthalate (PET) membrane by electrochemically depositing from organic solvent dimethylsulfoxide (DMSO) containing CdCl{sub 2} and elemental sulfur at the temperature 110 deg. C. The characterization of the sample of CdS needles was studied by scanning electron microscope, X-ray diffraction, absorption and photoluminescence spectra. The optical experiments show that in the sample of CdS needles there is an absorption peak that could be assigned to the interface states of the CdS needles.

An ultrasound needle insertion guide in a porcine phantom model.

Science.gov (United States)

Whittaker, S; Lethbridge, G; Kim, C; Keon Cohen, Z; Ng, I

2013-08-01

We compared nerve blockade with and without the Infiniti(TM) needle guide in an ultrasound in-plane porcine simulation. We recruited 30 anaesthetists with varying blockade experience. Using the guide, the needle tip was more visible (for a median (IQR [range]) of 67 (56-100]) % of the time; and invisible for 2 (1-4 [0-19]) s) than when the guide was not used (respectively 23 (13-43 [0-80]) % and 25 (9-52 [1-198]) s; both p < 0.001). The corresponding block times were 8 (6-10 [3-28]) s and 32 (15-67 [5-225]) s, respectively; p < 0.001. The needle guide reduced the block time and the time that the needle was invisible, irrespective of anaesthetist experience. Anaesthesia © 2013 The Association of Anaesthetists of Great Britain and Ireland.

Should fine needle aspiration cytology in breast assessment be abandoned?

International Nuclear Information System (INIS)

Litherland, Janet C.

2002-01-01

Fine needle aspiration cytology (FNAC) has been used extensively in the U.K. for the diagnosis of breast lesions over the past 15 years. More recently, large gauge needle biopsy has been used to address many of the problems which have been encountered with fine needle aspiration. This paper reviews the evolution of the use of these procedures and the advantages and disadvantages of each. In considering whether to abandon the use of fine needle aspiration cytology in breast assessment, each individual unit should make a decision based upon their own audited results. However, even if FNAC is retained, it is important to be able to complement cytological diagnosis with core biopsy as there are indisputable advantages, e.g. in the diagnosis of mammographically detected microcalcification. As always, a multi-disciplinary approach is ultimately essential for effective patient management. Litherland, J.C. (2002)

Self-aligning subatmospheric hybrid liquid junction electrospray interface for capillary electrophoresis

Czech Academy of Sciences Publication Activity Database

Křenková, Jana; Klepárník, Karel; Grym, Jakub; Luksch, Jaroslav; Foret, František

2016-01-01

Roč. 37, č. 3 (2016), s. 414-417 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * electrospray interfacing * microfabrication Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.744, year: 2016

Measurement of bio-impedance with a smart needle to confirm percutaneous kidney access.

Science.gov (United States)

Hernandez, D J; Sinkov, V A; Roberts, W W; Allaf, M E; Patriciu, A; Jarrett, T W; Kavoussi, L R; Stoianovici, D

2001-10-01

The traditional method of percutaneous renal access requires freehand needle placement guided by C-arm fluoroscopy, ultrasonography, or computerized tomography. This approach provides limited objective means for verifying successful access. We developed an impedance based percutaneous Smart Needle system and successfully used it to confirm collecting system access in ex vivo porcine kidneys. The Smart Needle consists of a modified 18 gauge percutaneous access needle with the inner stylet electrically insulated from the outer sheath. Impedance is measured between the exposed stylet tip and sheath using Model 4275 LCR meter (Hewlett-Packard, Sunnyvale, California). An ex vivo porcine kidney was distended by continuous gravity infusion of 100 cm. water saline from a catheter passed through the parenchyma into the collecting system. The Smart Needle was gradually inserted into the kidney to measure depth precisely using a robotic needle placement system, while impedance was measured continuously. The Smart Needle was inserted 4 times in each of 4 kidneys. When the needle penetrated the distended collecting system in 11 of 16 attempts, a characteristic sharp drop in resistivity was noted from 1.9 to 1.1 ohm m. Entry into the collecting system was confirmed by removing the stylet and observing fluid flow from the sheath. This characteristic impedance change was observed only at successful entry into the collecting system. A characteristic sharp drop in impedance signifies successful entry into the collecting system. The Smart Needle system may prove useful for percutaneous kidney access.

Voltage regulating circuit

NARCIS (Netherlands)

2005-01-01

A voltage regulating circuit comprising a rectifier (2) for receiving an AC voltage (Vmains) and for generating a rectified AC voltage (vrec), and a capacitor (3) connected in parallel with said rectified AC voltage for providing a DC voltage (VDC) over a load (5), characterized by a unidirectional

Enhanced Visualization of Fine Needles Under Sonographic Guidance Using a MEMS Actuator

Directory of Open Access Journals (Sweden)

Zhiyuan Shen

2015-01-01

Full Text Available Localization of a needle tip is important for biopsy examinations in clinics. However, the needle tip is sometimes difficult to discern under the guidance of sonography due to its poor visibility. A mini actuator that radiates a low-intensity ultrasound wave was manufactured using micro-electro-mechanical system (MEMS technology. Interference between the radiated and diagnostic ultrasound pulses was observed as bright lines in the B-mode ultrasound image, from which the mini actuator could be recognized with ease. Because the distance between the mini actuator and the needle tip is fixed, the needle tip can be determined despite its inconsistent appearance in the sonography. Both gel phantom and ex vivo tissue evaluation showed that the needle tip can be determined reliably utilizing the acoustic interference pattern.

Effect of ponderosa pine needle litter on grass seedling survival.

Science.gov (United States)

Burt R. McConnell; Justin G. Smith

1971-01-01

Hard fescue survival rates were followed for 6 years on four different pine needle treatment plots. Needle litter had a significant effect on initial survival of fescue seedlings, but subsequent losses undoubtedly resulted from the interaction of many factors.

Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns.

Science.gov (United States)

Yan, Wei-Cheng; Xie, Jingwei; Wang, Chi-Hwa

2018-06-06

Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided electrospray deposition. In this work, we reported for the first time the fabrication of gradient particle patterns on glass slides using an additional point, line, or bar electrode based on our previous electrospray deposition configuration. We also demonstrated that the polydimethylsiloxane (PDMS) coating could result in the formation of uniform particle patterns instead of gradient particle patterns on glass slides using the same experimental setup. Meanwhile, we investigated the effect of experimental configurations on the gradient particle pattern formation by computational simulation. The simulation results are in line with experimental observations. The formation of gradient particle patterns was ascribed to the gradient of electric field and the corresponding focusing effect. Cell patterns can be formed on the particle patterns deposited on PDMS-coated glass slides. The formed particle patterns hold great promise for high-throughput screening of biomaterial-cell interactions and sensing.

Driven Around the Bend: Novel Use of a Curved Steerable Needle

Energy Technology Data Exchange (ETDEWEB)

Murphy, Darra T., E-mail: darra.murphy@vch.ca; Korzan, Jeffrey R.; Ouellette, Hugue A.; Liu, David M. [Vancouver General Hospital, Department of Radiology (Canada); Clarkson, Paul W. [Vancouver General Hospital, Department of Orthopedic Surgery (Canada); Munk, Peter L. [Vancouver General Hospital, Department of Radiology (Canada)

2013-04-15

This technical note describes the novel use of a curved, steerable needle to access symptomatic osseous lesions in the pelvis and sacrum for palliative percutaneous treatment that would otherwise be difficult to treat using conventional straight needles. Seven patients with lytic bone lesions were treated. One patient had multiple myeloma; the remaining had metastatic disease: breast carcinoma (n = 2), colorectal carcinoma (n = 1), renal cell carcinoma (n = 1), squamous cell carcinoma (n = 1), and leiomyosarcoma (n = 1). Five of the seven patients had lesions in the posterior acetabulum, and the two other patients had lesions in the sacrum. Four of the seven patients received radiofrequency ablation followed by cementoplasty; three patients received cementation alone. We used a novel needle designed for vertebroplasty, which has an articulating tip allowing it to be guided into lytic bone lesions located in difficult-to-access regions of the pelvis and sacrum. All patients were successfully treated with cementoplasty either with or without thermal ablation. No serious adverse events were reported. The needle was difficult to withdraw in two patients. Steerable curved needles can be successfully used to treat lytic osseous metastases with cementoplasty when lesions are located in sites that may be difficult to reach using conventional straight needles.

Darning Needle Impacted in the Male Urethra | Singla | African ...

African Journals Online (AJOL)

Foreign bodies of varied nature have been introduced into the urethra to achieve sexual stimulation. We report the case of a long (9.5 cm) darning needle impacted in the urethra of a male patient following urethral masturbation. After a failed trial at endoscopic extraction the needle had to be removed via open surgery.

Ultrasound-guided core needle biopsy for breast cancer

International Nuclear Information System (INIS)

Naqvi, S.Q.H.; Solangi, R.A.; Memon, M.; Solangi, R.A.

2008-01-01

To evaluate the efficacy of ultrasound-guided core needle biopsy (US-CNB) as a preoperative diagnostic modality for breast cancer. Females with solid and/or intermediate breast lesions visualized on ultrasonography. Apart from clinical work-up, all the above mentioned patients underwent ultrasound-guided core needle biopsy and excisional biopsy of their breast lesions. The histopathological diagnosis on ultrasound-guided core needle biopsy was then compared with the findings of the excisional biopsy. Out of the total 93 cases, 47(50.5%) had benign lesions on ultrasound; US-CNB showed 24 as fibroadenomata, four with chronic non-specific mastitis, five chronic suppurative mastitis, one tuberculosis, four fat necrosis, two lactational adenoma and seven cases with benign ductal hyperplasia without atypia. Nine (9.7%) cases showed suspicious abnormality on ultrasound; US-CNB revealed five cases with atypical ductal hyperplasia, one ductal carcinoma in situ and three invasive ductal carcinoma. Thirty seven (39.8%) cases were highly suggestive of malignancy on ultrasound; US-CNB showed 34 as invasive ductal carcinoma, two invasive lobular and one medullary carcinoma. Excisional biopsy confirmed the diagnosis of ultrasound-guided core needle biopsy in all cases except four; one case of chronic suppurative mastitis was diagnosed as that of tuberculosis and three cases of atypial ductal hyperplasia as invasive ductal carcinoma. Hence there was no false positive case, but four (4.3%) false negative cases. The sensitivity of the US-CNB was thus 100% and specificity 91.1%. Ultrasound guided core needle biopsy is a satisfactory procedure for the histopathological diagnosis of breast lesions. Any unsatisfactory, suspicious or atypical change on US-CNB should be followed by an open biopsy. (author)

Nanojets, Electrospray, and Ion Field Evaporation: Molecular Dynamics Simulations and Laboratory Experiments

National Research Council Canada - National Science Library

Luedtke, W. D; Landman, Uzi; Chiu, Y. H; Levandier, D. J; Dressler, R. A; Sok, S; Gordon, M. S

2008-01-01

... experiment and using molecular dynamics (MD) simulations. The electrospray source is operated in a Taylor cone-jet mode, with the nanojet that forms being characterized by high surface-normal electric field strengths in the vicinity of I V/nm...

Needle displacement during HDR brachytherapy in the treatment of prostate cancer

International Nuclear Information System (INIS)

Damore, Steven J.; Syed, A.M. Nisar; Puthawala, Ajmel A.; Sharma, Anil

2000-01-01

Purpose: We used clinical patient data to examine implant displacement between high dose rate (HDR) brachytherapy fractions for prostate cancer to determine its impact on treatment delivery. Materials and Methods: We analyzed the verification films taken prior to each fraction for 96 consecutive patients treated with HDR brachytherapy boosts as part of their radiation therapy for definitive treatment of organ-confined prostate cancer at our institution. Patients were treated with 18-24 Gy in 4 fractions of HDR delivered in 40 hours followed by 36-39.6 Gy external beam radiation to the prostate. We determined the mean and maximum displacement distances of marker seeds placed in the prostate and of the implanted needles between HDR fractions. Results: Mean and maximum displacement distances between fractions were documented up to 7.6 mm and 28.5 mm, respectively, for the implant needles and 3.6 mm and 11.4 mm, respectively, for the gold marker seeds. All displacement of implant needles occurred in the caudal direction. At least 1 cm caudal displacement of needles occurred prior to 15.5% all fractions. Manual adjustment of needles was required prior to 15% of fractions, and adjustment of the CLP only was required in 24%. Most of the displacement for both the marker seeds and needles occurred between the first and second fractions. Conclusions: There is significant caudal displacement of interstitial implant needles between HDR fractions in our prostate cancer patients. Obtaining verification films and making adjustments in the treatment volume prior to each fraction is necessary to avoid significant inaccuracies in treatment delivery

Usefulness of sono-guided needle puncture for MR arthrography of the shoulder

International Nuclear Information System (INIS)

Choi, Jae Woong; Hong, Suk Ju; Suh, San Il; Yong, Hwan Suk; Kim, Jung Hyuk; Park, Cheol Min; Suh, Won Hyuck; Kim, Myung Gyu

2000-01-01

To evaluate the usefulness of sono-guided needle puncture for MR arthrography of the shoulder to locate the path of access and to control the correct placement of the needle into the shoulder. Fifteen patients with suspicion of shoulder pathology were included in this study. Patients were laid in supine positions with the arm extended and slightly abducted, the palm of the hand facing upward. A sonographic unit with a high resolution transducer with 7.5 MHz linear array was used. Axial images in the anterior aspect of the shoulder were obtained to localize the coracoid process and the anteromedical portion of the humerus. Using an aseptic technique, a 21-guage needle was advanced into the shoulder joint under ultrasonographic guidance. When the needle made contract with the articular cartilage of the humeral head, the needle was tiled to position is point in the articular cavity. Solution of 0.1 ml gadopentetate dimeglumine in 25 ml of normal saline was prepared and 12-16 ml was injected into the joint cavity. The intra-articular position of the needle and the compete distension of the shoulder joint were again confirmed by sonography. The needle was accurately placed in 14 out of 15 patients without damage to neighboring structures. It took 10 to 15 minutes to complete the procedure in 14 patients. No side effects attributable to gadopentetate dimeglumine were found. Sono-guided needle puncture for the shoulder MR arthrography can be a substitutable method for fluoroscopic guidance, with easy access, advantages of lacking radiation hazard and eliminating the need for iodized contrast agents.

Photosynthesis in Norway spruce seedlings infected by the needle rust Chrysomyxa rhododendri.

Science.gov (United States)

Bauer, Helmut; Plattner, Karin; Volgger, Waltraud

2000-02-01

Chrysomyxa rhododendri (DC.) De Bary is a needle rust with a host shift between Rhododendron sp. and Norway spruce (Picea abies (L.) Karst.), penetrating only the new developing flushes of the conifer. Because little is known about its effects on trees, we investigated several parameters related to photosynthesis in artificially infected 3-year-old Norway spruce seedlings. The potential efficiency of photosystem II (PSII; derived from chlorophyll fluorescence measurements) was reduced in infected current-year needles as soon as disease symptoms were visible, about three weeks after inoculation. Two weeks later, photosynthetic O(2) evolution (P(max)) of infected needles was less than 20% of control needles, whereas respiratory O(2) uptake (R(D)) was about three times higher than that of control needles. Nonstructural carbohydrate concentrations were about 60% of control values in all parts of the shoots of infected trees. Photosynthetic inhibition was associated with marked decreases in chlorophyll concentration and chlorophyll a/b ratio but only a small reduction in carotenoid concentration. In infected trees, P(max) of noninfected 1-year-old and 2-year-old needles was 50 and 80% higher than in the corresponding age class of needles of control trees. Estimation of potential daily net dry mass production, based on P(max), R(D), specific leaf area, carbon content and needle biomass, indicated that seedlings infected once were able to produce 60%, and those infected twice only 25%, of the dry mass of controls. We conclude that afforestation and regeneration of Norway spruce is seriously impaired in regions where seedlings are frequently attacked by Chrysomyxa.

C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

Science.gov (United States)

Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

2010-05-01

Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

Tattoo machines, needles and utilities.

Science.gov (United States)

Rosenkilde, Frank

2015-01-01

Starting out as a professional tattooist back in 1977 in Copenhagen, Denmark, Frank Rosenkilde has personally experienced the remarkable development of tattoo machines, needles and utilities: all the way from home-made equipment to industrial products of substantially improved quality. Machines can be constructed like the traditional dual-coil and single-coil machines or can be e-coil, rotary and hybrid machines, with the more convenient and precise rotary machines being the recent trend. This development has resulted in disposable needles and utilities. Newer machines are more easily kept clean and protected with foil to prevent crosscontaminations and infections. The machines and the tattooists' knowledge and awareness about prevention of infection have developed hand-in-hand. For decades, Frank Rosenkilde has been collecting tattoo machines. Part of his collection is presented here, supplemented by his personal notes. © 2015 S. Karger AG, Basel.

Learning Ultrasound-Guided Needle Insertion Skills through an Edutainment Game

Science.gov (United States)

Chan, Wing-Yin; Ni, Dong; Pang, Wai-Man; Qin, Jing; Chui, Yim-Pan; Yu, Simon Chun-Ho; Heng, Pheng-Ann

Ultrasound-guided needle insertion is essential in many of minimally invasive surgeries or procedures, such as biopsy, drug delivery, spinal anaesthesia, etc. Accurate and safe needle insertion is a difficult task due to the high requirement of hand-eye coordination skills. Many proposed virtual reality (VR) based training systems put their emphasis on realistic simulation instead of pedagogical efficiency. The lack of schematic training scenario leads to boredom of repetitive operations. To solve this, we present our novel training system with the integration of game elements in order to retain the trainees' enthusiasm. Task-oriented scenarios, time attack scenarios and performance evaluation are introduced. Besides, some state-of-art technologies are also presented, including ultrasound simulation, needle haptic rendering as well as a mass-spring-based needle-tissue interaction simulation. These works are shown to be effective to keep the trainees up with learning.

Needle stick injury in a radiology department: a decade analysis

International Nuclear Information System (INIS)

Sayani, R.; Rajani, A.

2012-01-01

Objectives: To determine the frequency of needle stick injury in health care workers of radiology department. Study type, settings and duration: Cross sectional, observational study conducted at the Radiology department of Aga Khan University hospital from January 2000 to May 2010. Subject and Methods: All self-reported needle stick injuries data of Health care workers of radiology department was recorded. The personnel involved (Radiologist, resident, radiographer, nurses etc), area of working and the causes of injury were identified including the procedural or post procedural details. Patient's status of hepatitis or blood borne infection was also noted. Data was recorded and analyzed in Excel worksheet. Results: A total of 55 health workers reported needle stick injuries at all sections of radiology departments with maximum number needle stick injuries at general radiography, fluoroscopy and IVP section. Radiographers and radiology residents received the maximum number of injuries. Major cause of injury was cannulation however, many injuries occurred during disposing or handling of bin. In majority of cases the patients were not infected with any known blood borne infections. Conclusions: Doctors and nurses get needle-stick injuries while carrying out clinical procedures, while, ancillary staff get infected post procedure during disposal of garbage. Policy message: Good occupational health and safety practices must be promoted to all staff. Safer disposal of needles is an important area where practice and procedure needs to be carefully reviewed. It is necessary to undertake a risk assessment, to offer counseling and Post Exposure Prophylaxis and treatment where necessary. (author)

Histopathologic quality of prostate core biopsy specimens: comparison of an MR-compatible biopsy needle and a ferromagnetic biopsy needle used for ultrasound-guided prostate biopsy

International Nuclear Information System (INIS)

Franiel, T.; Hamm, B.; Beyersdorff, D.; Fritzsche, F.; Staack, A.; Rost, J.

2006-01-01

Purpose: The histopathologic quality of core biopsy specimens obtained via MRI-guided prostate biopsy using a 16G MR-compatible needle was compared to that of biopsies obtained via ultrasound-guided biopsy using a conventional 18G stainless steel biopsy needle. Material and Methods: A retrospective analysis was performed for a total of 247 transrectal prostate biopsy specimens obtained from 32 patients. A total of 117 tissue cores were obtained from 15 patients (PSA of 10.8 ng/ml, age 64 years) who underwent an MRI-guided prostate biopsy using a 16G (1.7 mm) MR-compatible biopsy needle made of titanium alloy. The remaining 130 tissue cores were obtained from 17 patients (PSA of 6.7 ng/ml, age 68 years) who underwent a transrectal ultrasound-guided prostate biopsy using an 18G (1.3 mm) ferromagnetic stainless steel biopsy needle. The length and width of the histologic sections prepared from the tissue cores were measured to calculate the area. The histopathologic quality of the specimens was assessed microscopically using tissue fragmentation, the presence of crush artifacts, and the overall assessability as criteria. Each of these features was assigned a score from 0 to 3. All 3 features contributed equally to the overall score which ranged from 0 (no tissue) to 9 (optimal quality). Results: The overall quality scores assigned to the biopsies obtained with a 16G MR-compatible needle and an 18G ferromagnetic needle can be considered to be equivalent to a mean difference between patient related median scores of the specimens of -0.05 (95% confidence interval [-0.46; 0.36]) and a given equivalence limit of 1. The MRI biopsies showed more tissue fragmentation (p=0.001) but fewer crush artifacts (p=0.022) while the assessability did not differ significantly between the two needle types (p=0.064). There was also no significant difference in the calculated areas of the tissue cores (p=0.236). According to the different calibers of the biopsy needles, the lengths (p=0

Anomalous needle numbers on dwarf shoots of Pinus mugo and P. uncinata (Pinaceae

Directory of Open Access Journals (Sweden)

Krystyna Boratyńska

2011-01-01

Full Text Available The frequency of occurrence of abnormal, three- (or more needle dwarf shoots of most southern and central European two-needle pine (Pinus species were studied. No specimens with more than two-needle dwarf shoots were found in a population of P. nigra Arnold subsp. salzmannii (Dunal Franco from the Iberian Peninsula and in two populations of P. uliginosa Neumann from the Sudeten Mountains in Central Europe. Single specimens were found within one population of P. pinaster Aiton from the Iberian Peninsula and among six populations of P. sylvestris L. from the Iberian Peninsula and Central Europe. Abnormal dwarf shoots mostly with three, but also four, five or six needles were found among 24 of 25 surveyed populations of P. mugo Turra and P. uncinata Ramond. The average frequency of specimens with at least one three-needle dwarf shoot was 24% for P. mugo and 20% for P. uncinata. The frequencies of occurrence varied significantly among studied populations and were highest in samples collected from the upper elevational range limits of the species in the mountains and near the northern limits of their ranges. The frequency of abnormal dwarf shoots in the same populations was significantly high in 2-3 consecutive years. Needles from three-needle dwarf shoots were not significantly shorter than those of two-needle shoots.

Aerosols on the surface of needles in the vicinity of Winterthur

International Nuclear Information System (INIS)

Wyttenbach, A.; Tobler, L.; Bajo, S.

1991-01-01

The composition and the mass of aerosols residing on the surface of one-year-old needles of Norway spruce are described. The composition of aerosols on spruce needles is compared with that of aerosols collected by air filters and the composition of the local soil. A comparison of the years 1982 and 1985 shows virtually identical conditions. Finally, possible connections between aerosol mass and inherent needle content are discussed. (author) 5 figs., 2 tabs., 13 refs

EFFICACY OF IMMUNOHISTOCHEMISTRY IN PROSTATE NEEDLE BIOPSIES

Directory of Open Access Journals (Sweden)

Tameem Afroz

2016-10-01

Full Text Available BACKGROUND Prostate needle biopsies can pose a major diagnostic challenge when it comes to differentiating adenocarcinoma and its variants from its benign mimics. In needle biopsies, when the suspicious focus is small, morphological features may not suffice to differentiate it from its morphologic mimics like atrophy, basal cell hyperplasia, reactive inflammatory changes, seminal vesicles and adenosis. Immunohistochemical marker for basal cells, p63 and prostate cancer specific marker, Alpha-Methylacyl-CoA Racemase (AMACR help in overcoming such diagnostic dilemmas. MATERIALS AND METHODS We analysed 157 prostate core needle biopsies over a period of 2 years. Routine Hematoxylin and Eosin (H and E sections and immunohistochemical markers for basal cells (p63 and prostate cancer specific marker (AMACR were used. Prospective study was done on prostate needle core biopsies. Biopsy was done under ultrasound guidance with an 18-gauge needle. Biopsy was done in patients with raised serum PSA levels for exclusion of prostate carcinoma. RESULTS Over a period of two years, 157 prostate core needle biopsies were studied. 83 were benign lesions comprising 69 benign prostatic hyperplasias, five basal cell hyperplasias, four granulomatous lesions and three showed atrophic changes. Two biopsies morphologically resembled seminal vesicles. Prostate cancer specific marker, AMACR was negative in all, but two lesions. In these two lesions, it showed weak nonspecific staining. Basal cell marker p63 showed a continuous staining pattern highlighting the basal cells in all the 69 cases of benign prostatic hyperplasia, 5 cases of basal hyperplasia showed positivity in all the hyperplastic basal cells. In the two cases of seminal vesicles, it showed intense basal cell positivity. It showed a discontinuous pattern in two of the four granulomatous lesions and showed a weak, but a continuous staining pattern in the atrophic lesions. 74 were adenocarcinomas; the predominant

CT-guided core biopsy of malignant lung lesions: how many needle passes are needed?

International Nuclear Information System (INIS)

Lim, Chaehun; Han, Dae Hee; Lee, Kyo Young; Kim, Young Kyoon; Ko, Jeong Min

2013-01-01

The study aims to determine the number of needle pass in the CT-guided core needle biopsy (CNB) in making a diagnosis of pulmonary malignancy. A total of 434 CNB records were retrospectively reviewed. The specimen obtained from each needle pass was put in a formalin container and then labelled for separate histopathological reporting. The patients were divided into five groups according to the total number of needle passes (n=1, n=2, n=3, n=4 and n≥5). In each of the groups 2–4, it was analysed how many needle passes are required before a plateau in diagnostic yield is achieved. CNB produced 283 true-positive and 23 false-negative diagnosis of malignancy. Cumulative sensitivity significantly (P<0.05) increased between the first and second as well as the second and the third (if done) needle passes, but not between the third and fourth ones. Three coaxial needle passes might be optimal in the diagnosis of lung malignancy.

Synthesis and Characterization of Pine Needles Reinforced RF Matrix Based Biocomposites

Directory of Open Access Journals (Sweden)

A. S. Singha

2008-01-01

Full Text Available Synthesis and characterization of pine needles reinforced thermosetting resin (Resorcinol-Formaldehyde which is most suitable as composite matrix has been reported. The polycondensation reaction between resorcinol and formaldehyde (RF in different molar ratios has been applied to the synthesis of RF polymer matrix. A thermosetting resin based composite, containing approximately 10, 20, 30 and 40% of natural fiber by weight, has been obtained by adding pine needles to the Resorcinol-Formaldehyde (RF resin. The mechanical properties of randomly oriented intimately mixed particle reinforced (Pine needles composites were determined. Effect of fiber loading in terms of weight % on mechanical properties such as tensile, compressive, and flexural and wear properties have also been evaluated. The reinforcing of the resin with Pine needles was accomplished in particle size of 200 micron by employing optimized resin. Present work reveals that mechanical properties of the RF resin increases to extensive extent when reinforced with Pine needles. Thermal (TGA/DTA and morphological studies (SEM of the resin, fiber and polymer composites thus synthesized have also been carried out.

Beyond voltage-gated ion channels: Voltage-operated membrane proteins and cellular processes.

Science.gov (United States)

Zhang, Jianping; Chen, Xingjuan; Xue, Yucong; Gamper, Nikita; Zhang, Xuan

2018-04-18

Voltage-gated ion channels were believed to be the only voltage-sensitive proteins in excitable (and some non-excitable) cells for a long time. Emerging evidence indicates that the voltage-operated model is shared by some other transmembrane proteins expressed in both excitable and non-excitable cells. In this review, we summarize current knowledge about voltage-operated proteins, which are not classic voltage-gated ion channels as well as the voltage-dependent processes in cells for which single voltage-sensitive proteins have yet to be identified. Particularly, we will focus on the following. (1) Voltage-sensitive phosphoinositide phosphatases (VSP) with four transmembrane segments homologous to the voltage sensor domain (VSD) of voltage-gated ion channels; VSPs are the first family of proteins, other than the voltage-gated ion channels, for which there is sufficient evidence for the existence of the VSD domain; (2) Voltage-gated proton channels comprising of a single voltage-sensing domain and lacking an identified pore domain; (3) G protein coupled receptors (GPCRs) that mediate the depolarization-evoked potentiation of Ca 2+ mobilization; (4) Plasma membrane (PM) depolarization-induced but Ca 2+ -independent exocytosis in neurons. (5) Voltage-dependent metabolism of phosphatidylinositol 4,5-bisphosphate (PtdIns[4,5]P 2 , PIP 2 ) in the PM. These recent discoveries expand our understanding of voltage-operated processes within cellular membranes. © 2018 Wiley Periodicals, Inc.

[Acupuncture therapy for regaining consciousness in terms of acupoint location, needle insertion and needle manipulation].

Science.gov (United States)

Meng, Xianggang; Gu, Wenlong; Ma, Fen; Du, Yuzheng; Zhao, Qi

2015-03-01

Acupuncture therapy for regaining consciousness activates soreness, numbness, distention, heaviness, radiating and moving, electric shock and ant climbing sensations at the specific acupoints in the stroke patients. Radiating and moving sensations are the summary of needling sensations such as soreness, numbness and twitching presenting during lifting and thrusting manipulation. These sensations are the essential factors of the therapeutic effect of regaining consciousness. Radiating sensation refers to the conduction along meridians and radiation of soreness and numbness. Moving sensation refers to the local muscular twitching at acupoints and the involuntary movement of limbs, joints and the distal. Acupuncture at the specific acupoints achieves radiating and moving sensations for promoting the circulation in meridians, regulating qi and mind and balancing yin and yang in stroke patients. This therapy was introduced in the paper in view of acupoint location, needle insertion and manipulation.

Physicochemical characterization of atorvastatin calcium/ezetimibe amorphous nano-solid dispersions prepared by electrospraying method.

Science.gov (United States)

Jahangiri, Azin; Barzegar-Jalali, Mohammad; Javadzadeh, Yousef; Hamishehkar, Hamed; Adibkia, Khosro

2017-09-01

In the present study, electrospraying was applied as a novel method for the fabrication of amorphous nano-solid dispersions (N-SDs) of atorvastatin calcium (ATV), ezetimibe (EZT), and ATV/EZT combination as poorly water-soluble drugs. N-SDs were prepared using polyvinylpyrrolidone K30 as an amorphous carrier in 1:1 and 1:5 drug to polymer ratios and the total solid (including drug and polymer) concentrations of 10 and 20% (w/v). The prepared formulations were further investigated for their morphological, physicochemical, and dissolution properties. Scanning electron microscopy studies indicated that the morphology and diameter of the electrosprayed samples (ESs) were influenced by the solution concentration and drug:polymer ratio, so that an increase in the solution concentration resulted in fiber formation while an increase in the polymer ratio led to enhancement of the particle diameter. Differential scanning calorimetry and X-ray powder diffraction studies together with in vitro dissolution test revealed that the ESs were present in an amorphous form with improved dissolution properties. Infrared spectroscopic studies showed hydrogen-bonding interaction between the drug and polymer in ESs. Since the electrospraying method benefits from the both amorphization and nanosizing effect, this novel approach seems to be an efficient method for the fabrication of N-SDs of poorly water-soluble drugs.

Clarification of the characteristics of needle-tip movement during vacuum venipuncture to improve safety.

Science.gov (United States)

Fujii, Chieko

2013-01-01

Complications resulting from venipuncture include vein and nerve damage, hematoma, and neuropathic pain. Although the basic procedures are understood, few analyses of actual data exist. It is important to improve the safety standards of this technique during venipuncture. This study aimed to obtain data on actual needle movement during vacuum venipuncture in order to develop appropriate educational procedures. Six experienced nurses were recruited to collect blood samples from 64 subjects. These procedures were recorded using a digital camera. Software was then used to track and analyze motion without the use of a marker in order to maintain the sterility of the needle. Movement along the X- and Y-axes during blood sampling was examined. Approximately 2.5 cm of the needle was inserted into the body, of which 6 mm resulted from advancing or moving the needle following puncture. The mean calculated puncture angle was 15.2°. Given the hazards posed by attaching and removing the blood collection tube, as well as by manipulating the needle to fix its position, the needle became unstable whether it was fixed or not fixed. This study examined venipuncture procedures and showed that the method was influenced by increased needle movement. Focusing on skills for puncturing the skin, inserting the needle into the vein, and changing hands while being conscious of needle-tip stability may be essential for improving the safety of venipuncture.

Real-Time Metabolomics on Living Microorganisms Using Ambient Electrospray Ionization Flow-Probe

DEFF Research Database (Denmark)

Hsu, Cheng-Chih; ElNaggar, Mariam S.; Peng, Yao

2013-01-01

sampling probe for electrospray ionization-mass spectrometry to extract and ionize metabolite mixtures directly from living microbial colonies grown on soft nutrient agar in Petri-dishes without any sample pretreatment. To demonstrate the robustness of the method, this technique was applied to observe...

A decade of microfluidic analysis coupled with electrospray mass spectrometry: An overview

NARCIS (Netherlands)

Koster, S.; Verpoorte, E.

2007-01-01

This review presents a thorough overview covering the period 1997-2006 of microfluidic chips coupled to mass spectrometry through an electrospray interface. The different types of fabrication processes and materials used to fabricate these chips throughout this period are discussed. Three 'eras' of

A decade of microfluidic analysis coupled with electrospray mass spectrometry : An overview

NARCIS (Netherlands)

Koster, Sander; Verpoorte, Elisabeth

2007-01-01

This review presents a thorough overview covering the period 1997-2006 of microfluidic chips coupled to mass spectrometry through an electrospray interface. The different types of fabrication processes and materials used to fabricate these chips throughout this period are discussed. Three 'eras' of

Facile fabrication of super-hydrophobic nano-needle arrays via breath figures method.

Science.gov (United States)

Kim, Jiseok; Lew, Brian; Kim, Woo Soo

2011-12-06

Super-hydrophobic surfaces which have been fabricated by various methods such as photolithography, chemical treatment, self-assembly, and imprinting have gained enormous attention in recent years. Especially 2D arrays of nano-needles have been shown to have super-hydrophobicity due to their sharp surface roughness. These arrays can be easily generated by removing the top portion of the honeycomb films prepared by the breath figures method. The hydrophilic block of an amphiphilic polymer helps in the fabrication of the nano-needle arrays through the production of well-ordered honeycomb films and good adhesion of the film to a substrate. Anisotropic patterns with water wettability difference can be useful for patterning cells and other materials using their selective growth on the hydrophilic part of the pattern. However, there has not been a simple way to generate patterns with highly different wettability. Mechanical stamping of the nano-needle array with a polyurethane stamp might be the simplest way to fabricate patterns with wettability difference. In this study, super-hydrophobic nano-needle arrays were simply fabricated by removing the top portion of the honeycomb films. The maximum water contact angle obtained with the nano-needle array was 150°. By controlling the pore size and the density of the honeycomb films, the height, width, and density of nano-needle arrays were determined. Anisotropic patterns with different wettability were fabricated by simply pressing the nano-needle array at ambient temperature with polyurethane stamps which were flexible but tough. Mechanical stamping of nano-needle arrays with micron patterns produced hierarchical super-hydrophobic structures.PACS: 05.70.Np, 68.55.am, 68.55.jm.

Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles.

Science.gov (United States)

Cronn, Richard; Dolan, Peter C; Jogdeo, Sanjuro; Wegrzyn, Jill L; Neale, David B; St Clair, J Bradley; Denver, Dee R

2017-07-24

Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) needles at diurnal and circannual scales. Using mRNA sequencing, we sampled 6.1 × 10 9 reads from 19 trees and constructed a de novo pan-transcriptome reference that includes 173,882 tree-derived transcripts. Using this reference, we mapped RNA-Seq reads from 179 samples that capture daily and annual variation. We identified 12,042 diurnally-cyclic transcripts, 9299 of which showed homology to annotated genes from other plant genomes, including angiosperm core clock genes. Annual analysis revealed 21,225 circannual transcripts, 17,335 of which showed homology to annotated genes from other plant genomes. The timing of maximum gene expression is associated with light intensity at diurnal scales and photoperiod at annual scales, with approximately half of transcripts reaching maximum expression +/- 2 h from sunrise and sunset, and +/- 20 days from winter and summer solstices. Comparisons with published studies from other conifers shows congruent behavior in clock genes with Japanese cedar (Cryptomeria), and a significant preservation of gene expression patterns for 2278 putative orthologs from Douglas-fir during the summer growing season, and 760 putative orthologs from spruce (Picea) during the transition from fall to winter. Our study highlight the extensive diurnal and circannual transcriptome variability demonstrated in conifer needles. At these temporal scales, 29% of expressed transcripts show a significant diurnal cycle, and 58.7% show a significant circannual cycle. Remarkably

Arthropods and passerine birds in coniferous forest. The impact of acidification and needle-loss

Energy Technology Data Exchange (ETDEWEB)

Gunnarsson, B. [Goeteborg Univ., Dept. of Zoology, Sect. of Animal Ecology, Goeteborg (Sweden)

1995-12-31

The micro-habitat structure on coniferous trees changes as a result of needle-loss. This structural change in the vegetation may affect arthropods living in spruce Picea abies by indirect mechanisms, e.g. altered relations between prey and predators. The impact of acidification and needle-loss on some tree-living arthropods and passerine birds is reviewed. New information about the taxonomic composition of spiders in relation to needle density in a field experiments is reported. The main combined findings from the review and field experiments are: 1) Acid precipitation may be toxic because of high H{sup +} concentrations. However, simulated acid rain (pH 4.0) did not reduce the growth rate of a spruce-living spider. There is a present no evidence of toxic effect on arthropods at this level of pH. 2) Experiments in the field and laboratory and data from natural populations suggested that spruce-living arthropods are affected by the needle density of branches. These data showed a positive correlation between needle density and spider abundance. However, a large-scale field experiment could not confirm this relationship. 3) The interaction between bird predation and needle density was examined in a large-scale field experiment. There were strong negative effects of bird predation on arthropod abundance. Moreover, the taxonomic composition among spiders changed as a result of bird predation: raptorial spiders increased their relative abundance whereas sheetweb spiders decreased their relative abundance when bird predation was excluded. There were also some cases of bird predation/needle density interactions. In the absence of bird predation, the needle density affected the spider size distribution: large spiders were more common on needle-sparse branches than on needle-dens ones. The species composition was affected by similar interactions, e.g. bird predation effects on crab spiders (Thomisidae) were found on needle-sparse branches only. (Abstract Truncated)

Influence of needle position on lumbar segmental nerve root block selectivity.

Science.gov (United States)

Wolff, André P; Groen, Gerbrand J; Wilder-Smith, Oliver H

2006-01-01

In patients with chronic low back pain radiating to the leg, segmental nerve root blocks (SNRBs) are performed to predict surgical outcome and identify the putative symptomatic spinal nerve. Epidural spread may lead to false interpretation, affecting clinical decision making. Systematic fluoroscopic analysis of epidural local anesthetic spread and its relationship to needle tip location has not been published to date. Study aims include assessment of epidural local anesthetic spread and its relationship to needle position during fluoroscopy-assisted blocks. Patients scheduled for L4, L5, and S1 blocks were included in this prospective observational study. Under fluoroscopy and electrostimulation, they received 0.5 mL of a mixture containing lidocaine 5 mg and iohexol 75 mg. X-rays with needle tip and contrast were scored for no epidural spread (grade 0), local spread epidurally (grade 1), or to adjacent nerve roots (grade 2). Sixty-five patients were analyzed for epidural spread, 62 for needle position. Grade 1 epidural spread occurred in 47% of L4 and 28% of L5 blocks and grade 2 spread in 3 blocks (5%; L5 n = 1, S1 n = 2). For lumbar blocks, the needle was most frequently found in the lateral upper half of the intervertebral foramen. Epidural spread occurred more frequently with medial needle positions (P = .06). The findings suggest (P = .06) that the risk of grade 1 and 2 lumbar epidural spread, which results in decreased SNRB selectivity, is greater with medial needle positions in the intervertebral foramen. The variability in anatomic position of the dorsal root ganglion necessitates electrostimulation to guide SNRB in addition to fluoroscopy.

Study on Ballistic Absorbing Energy Character of High Performance Polyethylene Needle Felt

Science.gov (United States)

Kailiang, Zhu; Jianqiao, Fu

2017-11-01

The ballistic performance of polyethylene needle felt is tested and the failure morphology after test is also observed. The results showed that when the non-dimensionally non-stressed fibers in polyethylene needles are subjected to high-speed projectile, secondary movement such as stretching and twisting occurs first. This secondary movement is very full, it is the main way of ballistic absorbing energy of the polyethylene needle felt which can avoid the polyethylene fiber short-term rapid heating-up and destroyed. Analysis results show that under normal temperature and humidity conditions, the V50 of 6-layer forded polyethylene needle felt sample is 250m/s. At (450 ± 50) m/s speed range of the target missile, the mean value of the penetrative specific energy absorption for 3-layer forded polyethylene needle felt anti-1.1g simulated projectiles (tapered column) reaches 24.1J·m2/kg.

The intravenous injection of illicit drugs and needle sharing: an historical perspective.

Science.gov (United States)

Zule, W A; Vogtsberger, K N; Desmond, D P

1997-01-01

This study reviewed the literature on the history of needle sharing and intravenous drug abuse. Reports suggest that needle sharing was practiced by drug abusers as early as 1902 in China and 1914 in the United States. Intravenous drug abuse was first mentioned in the literature in 1925. However other references suggest that some opioid users were injecting intravenously prior to 1920. Outbreaks of malaria in Egypt, the United States, and China between 1929 and 1937 were attributed to needle sharing and intravenous injection of opioids. These reports suggest that both needle sharing and intravenous drug use were common by 1937. Factors such as medical use of intravenous injections, enactment and zealous enforcement of antinarcotic laws, and interactions among drug users in institutional settings such as regional hospitals and prisons may have contributed to the spread of both needle sharing and the intravenous technique among drug abusers.

A basic study on the development of deodorants using pine needle oil

Energy Technology Data Exchange (ETDEWEB)

Doh, K.S.; Lee, H.J. [Department of Chemical Engineering, Soongsil University, Seoul (Korea, Republic of); Kim, D.K. [Chemical Technology Division, Korea Research Institute of Chemical Technology, Taejon (Korea, Republic of)

1997-11-01

The basic study on the development of deodorant made from pine needle oil was performed. The pine needle oil(PNO) was analysed using GC, GC/MS and FT-1R analyzer for analysis of chemical concentration, chemical components and structure. The analysis results obtained from GC and GC/MS analyzer were composed to main components of {alpha},{beta}-Pinene(C{sub 10}H{sub 16}), 3-Carene (C{sub 10}H{sub 16}), {Upsilon}-terpinene(C{sub 10}H{sub 16}) and terpinolene(C{sub 10}H{sub 16}), etc. Also, the concentration of heavy metals analysed from AAS analyzer. The COD and BOD concentration of landfill leachate with pine needle oil were surveyed. As a results, the pine needle oil extracted from pine needles can be used to remove bad smells of wastes as a deodorant. (author). 13 refs., 3 figs., 3 tabs.

Stray voltage mitigation

Energy Technology Data Exchange (ETDEWEB)

Jamali, B.; Piercy, R.; Dick, P. [Kinetrics Inc., Toronto, ON (Canada). Transmission and Distribution Technologies

2008-04-09

This report discussed issues related to farm stray voltage and evaluated mitigation strategies and costs for limiting voltage to farms. A 3-phase, 3-wire system with no neutral ground was used throughout North America before the 1930s. Transformers were connected phase to phase without any electrical connection between the primary and secondary sides of the transformers. Distribution voltage levels were then increased and multi-grounded neutral wires were added. The earth now forms a parallel return path for the neutral current that allows part of the neutral current to flow continuously through the earth. The arrangement is responsible for causing stray voltage. Stray voltage causes uneven milk production, increased incidences of mastitis, and can create a reluctance to drink water amongst cows when stray voltages are present. Off-farm sources of stray voltage include phase unbalances, undersized neutral wire, and high resistance splices on the neutral wire. Mitigation strategies for reducing stray voltage include phase balancing; conversion from single to 3-phase; increasing distribution voltage levels, and changing pole configurations. 22 refs., 5 tabs., 13 figs.

Design, demonstration and performance of a versatile electrospray aerosol generator for nanomaterial research and applications

International Nuclear Information System (INIS)

Jennerjohn, Nancy; Fung, David C; Hirakawa, Karen S; Hinds, William; Kennedy, Nola J; Eiguren-Fernandez, Arantzazu; Prikhodko, Sergey; Zavala-Mendez, Jose D

2010-01-01

Carbon nanotubes are difficult to aerosolize in a controlled manner. We present a method for generating aerosols not only of carbon nanotubes, but also of many reference and proprietary materials including quantum dots, diesel particulate matter, urban dust, and their mixtures, using electrospraying. This method can be used as a teaching tool, or as the starting point for advanced research, or to deliver nanomaterials in animal exposure studies. This electrospray system generates 180 μg of nanotubes per m 3 of carrier gas, and thus aerosolizes an occupationally relevant mass concentration of nanotubes. The efficiency achievable for single-walled carbon nanotubes is 9.4%. This system is simple and quick to construct using ordinary lab techniques and affordable materials. Since it is easy to replace soiled parts with clean ones, experiments on different types of nanomaterial can be performed back to back without contamination from previous experiments. In this paper, the design, fabrication, operation and characterization of our versatile electrospray method are presented. Also, the morphological changes that carbon nanotubes undergo as they make the transition from dry powders to aerosol particles are presented.

Comments on the variability of inherent bioelement contents of spruce needles

International Nuclear Information System (INIS)

Wyttenbach, A.; Tobler, L.; Bajo, S.

1991-01-01

Inherent needle contents are the relevant concentrations within the needle, excluding surface contaminations by aerosols. The error arising from the analysis of unwashed needles is quantified. For many elements it is the source of a large apparent variability. Spatial variability is discussed under the aspects of variability among trees within a plot and of variability among different plots. Both terms have implications as to the number of trees that should be sampled for the characterization of a plot. Variability with time is investigated by following the needle concentrations from an age of 1 to 23 months. The results give indications on favourable sampling dates and on the physiology of the different elements. All investigations refer to 20 elements, which have been determined by neutron activation analysis. (author) 6 figs., 5 tabs., 16 refs

Needles and Other Sharps (Safe Disposal Outside of Health Care Settings)

Science.gov (United States)

... disorders, and psoriasis. Examples of sharps include: Needles – hollow needles used to inject drugs (medication) under the ... and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993 1-888-INFO-FDA (1-888- ...

Clinical observation of needle revision and 5-fluorouracil subconjunctive injection for the dysfunctional filtering blebs

Directory of Open Access Journals (Sweden)

Yan-Hua Gao

2016-07-01

Full Text Available AIM:To investigate the efficacy and safety of needle revision with 5-fluorouracil(5-FUon the dysfunctional filtering blebs after trabeculectomy and to assess the factors that may impact the success. METHODS:Eighty-three eyes in 76 patients underwent the needle revision and 5-FU subconjunctive injection for the dysfunctional blebs after trabeculectomy and were followed up for 12mo. The intraocular pressure(IOP, the number of drugs, corneal endothclium, bleb morphology and complications were observed and recorded. RESULTS:IOP decreased significantly from 35.3±5.8mmHg(1kPa=7.5mmHgof pre-needling to 17.0±4.3mmHg of post-needling(PPCI: 10.3-11.6. Statistically, there were no significant difference on needling effect with reference to the types of glaucoma, the use of mitomycin C(MMCduring the previous filtration surgery, the ages of patients, the intervals of needling operation from previous trabeculectomy, while there were significant difference on needling effect with reference to bleb appearance before needling, and the mean number of needling in patients that had surgery within 3mo were less than those who had surgery for more than 3mo. CONCLUSION: The needle revision combined with 5-FU is a safe, effective and simple method. Dysfunctional blebs should be treated early after trabeculectomy.

Pelton turbine Needle erosion prediction based on 3D three- phase flow simulation

International Nuclear Information System (INIS)

Chongji, Z; Yexiang, X; Wei, Z; Yangyang, Y; Lei, C; Zhengwei, W

2014-01-01

Pelton turbine, which applied to the high water head and small flow rate, is widely used in the mountainous area. During the operation period the sediment contained in the water does not only induce the abrasion of the buckets, but also leads to the erosion at the nozzle which may damage the needle structure. The nozzle and needle structure are mainly used to form high quality cylindrical jet and increase the efficiency of energy exchange in the runner to the most. Thus the needle erosion will lead to the deformation of jet, and then may cause the efficiency loss and cavitation. The favourable prediction of abrasion characteristic of needle can effectively guide the optimization design and maintenance of needle structure. This paper simulated the unsteady three-dimensional multi-phase flow in the nozzle and injected jet flow. As the jet containing water and sediment is injected into the free atmosphere air with high velocity, the VOF model was adopted to predict the water and air flow. The sediment is simplified into round solid particle and the discrete particle model (DPM) was employed to predict the needle abrasion characteristic. The sand particle tracks were analyzed to interpret the mechanism of sand erosion on the needle surface. And the numerical result of needle abrasion was obtained and compared with the abrasion field observation. The similarity of abrasion pattern between the numerical results and field observation illustrated the validity of the 3D multi-phase flow simulation method

Pelton turbine Needle erosion prediction based on 3D three- phase flow simulation

Science.gov (United States)

Chongji, Z.; Yexiang, X.; Wei, Z.; Yangyang, Y.; Lei, C.; Zhengwei, W.

2014-03-01

Pelton turbine, which applied to the high water head and small flow rate, is widely used in the mountainous area. During the operation period the sediment contained in the water does not only induce the abrasion of the buckets, but also leads to the erosion at the nozzle which may damage the needle structure. The nozzle and needle structure are mainly used to form high quality cylindrical jet and increase the efficiency of energy exchange in the runner to the most. Thus the needle erosion will lead to the deformation of jet, and then may cause the efficiency loss and cavitation. The favourable prediction of abrasion characteristic of needle can effectively guide the optimization design and maintenance of needle structure. This paper simulated the unsteady three-dimensional multi-phase flow in the nozzle and injected jet flow. As the jet containing water and sediment is injected into the free atmosphere air with high velocity, the VOF model was adopted to predict the water and air flow. The sediment is simplified into round solid particle and the discrete particle model (DPM) was employed to predict the needle abrasion characteristic. The sand particle tracks were analyzed to interpret the mechanism of sand erosion on the needle surface. And the numerical result of needle abrasion was obtained and compared with the abrasion field observation. The similarity of abrasion pattern between the numerical results and field observation illustrated the validity of the 3D multi-phase flow simulation method.

Needle localization using a moving stylet/catheter in ultrasound-guided regional anesthesia: a feasibility study

Science.gov (United States)

Beigi, Parmida; Rohling, Robert

2014-03-01

Despite the wide range and long history of ultrasound guided needle insertions, an unresolved issue in many cases is clear needle visibility. A well-known ad hoc technique to detect the needle is to move the stylet and look for changes in the needle appearance. We present a new method to automatically locate a moving stylet/catheter within a stationary cannula using motion detection. We then use this information to detect the needle trajectory and the tip. The differences between the current frame and the previous frame are detected and localized, to minimize the influence of tissue global motions. A polynomial fit based on the detected needle axis determines the estimated stylet shaft trajectory, and the extent of the differences along the needle axis represents the tip. Over a few periodic movements of the stylet including its full insertion into the cannula to the tip, a combination of polynomial fits determines the needle trajectory and the last detected point represents the needle tip. Experiments are conducted in water bath and bovine muscle tissue for several stylet/catheter materials. Results show that a plastic stylet has the best needle shaft and tip localization accuracy in the water bath with RMSE = 0:16 mm and RMSE = 0:51 mm, respectively. In the bovine tissue, the needle tip was best localized with the plastic catheter with RMSE = 0:33 mm. The stylet tip localization was most accurate with the steel stylet, with RMSE = 2:81 mm and the shaft was best localized with the plastic catheter, with RMSE = 0:32 mm.

A data-driven soft sensor for needle deflection in heterogeneous tissue using just-in-time modelling.

Science.gov (United States)

Rossa, Carlos; Lehmann, Thomas; Sloboda, Ronald; Usmani, Nawaid; Tavakoli, Mahdi

2017-08-01

Global modelling has traditionally been the approach taken to estimate needle deflection in soft tissue. In this paper, we propose a new method based on local data-driven modelling of needle deflection. External measurement of needle-tissue interactions is collected from several insertions in ex vivo tissue to form a cloud of data. Inputs to the system are the needle insertion depth, axial rotations, and the forces and torques measured at the needle base by a force sensor. When a new insertion is performed, the just-in-time learning method estimates the model outputs given the current inputs to the needle-tissue system and the historical database. The query is compared to every observation in the database and is given weights according to some similarity criteria. Only a subset of historical data that is most relevant to the query is selected and a local linear model is fit to the selected points to estimate the query output. The model outputs the 3D deflection of the needle tip and the needle insertion force. The proposed approach is validated in ex vivo multilayered biological tissue in different needle insertion scenarios. Experimental results in five different case studies indicate an accuracy in predicting needle deflection of 0.81 and 1.24 mm in the horizontal and vertical lanes, respectively, and an accuracy of 0.5 N in predicting the needle insertion force over 216 needle insertions.

Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers.

Science.gov (United States)

Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György

2009-08-01

Ultrasound imaging is becoming increasingly important in prostate brachytherapy. In high-dose-rate (HDR) real-time planning procedures the definition of the implant needles is often performed by transrectal ultrasound. This article describes absolute measurements of the visibility and accuracy of manual detection of implant needle tips and compares measurement results of different biplane ultrasound systems in transversal and longitudinal (i.e., sagittal) ultrasound modes. To obtain a fixed coordinate system and stable conditions the measurements were carried out in a water tank using a dedicated marker system. Needles were manually placed in the phantom until the observer decided by the real-time ultrasound image that the zero position was reached. A comparison of three different ultrasound systems yielded an offset between 0.8 and 3.1 mm for manual detection of the needle tip in ultrasound images by one observer. The direction of the offset was discovered to be in the proximal direction, i.e., the actual needle position was located more distally compared to the ultrasound-based definition. In the second part of the study, the ultrasound anisotropy of trocar implant needles is reported. It was shown that the integrated optical density in a region of interest around the needle tip changes with needle rotation. Three peaks were observed with a phase angle of 120 degrees. Peaks appear not only in transversal but also in longitudinal ultrasound images, with a phase shift of 60 degrees. The third section of this study shows results of observer dependent influences on needle tip detection in sagittal ultrasound images considering needle rotation. These experiments were carried out using the marker system in a water tank. The needle tip was placed exactly at the position z=0 mm. It was found that different users tend to differently interpret the same ultrasound images. The needle tip was manually detected five times in the ultrasound images by three experienced observers

Endoscopic treatment for pancreatic diseases: Needle-knife-guided cannulation via the minor papilla.

Science.gov (United States)

Wang, Wei; Gong, Biao; Jiang, Wei-Song; Liu, Lei; Bielike, Kouken; Xv, Bin; Wu, Yun-Lin

2015-05-21

To determine the efficacy and safety of meticulous cannulation by needle-knife. Three needle-knife procedures were used to facilitate cannulation in cases when standard cannulation techniques failed. A total of 104 cannulations via the minor papilla attempted in 74 patients at our center between January 2008 and June 2014 were retrospectively reviewed. Standard methods were successful in 79 cannulations. Of the 25 cannulations that could not be performed by standard methods, 19 were performed by needle-knife, while 17 (89.5%) were successful. Needle-knife use improved the success rate of cannulation [76.0%, 79/104 vs 92.3%, (79 + 17)/104; P = 0.001]. When the 6 cases not appropriate for needle-knife cannulation were excluded, the success rate was improved further (80.6%, 79/98 vs 98.0%, 96/98; P = 0.000). There were no significant differences in the rates of post-endoscopic retrograde cholangiopancreatography adverse events between the group using standard methods alone and the group using needle-knife after failure of standard methods (4.7% vs 10.5%, P = 0.301). The needle-knife procedure may be an alternative method for improving the success rate of cannulation via the minor papilla, particularly when standard cannulation has failed.

The combination of electrospray and flow focusing

Science.gov (United States)

Gañán-Calvo, Alfonso M.; López-Herrera, José M.; Riesco-Chueca, Pascual

2006-11-01

An ultra-fine liquid atomization procedure combining the advantages of electrospray and flow focusing is presented. Both techniques are known to produce strikingly small and steady liquid micro-jets issuing from menisci held by capillary forces. Such menisci take the form of a cusp-like drop attached to the feeding tube (flow focusing: FF) or a Taylor cone (electrospray: ES). The issuing micro-jets are forced or ‘sucked’ from the parent meniscus either by pressure or electrohydrodynamic forces. Subsequent capillary breakup of the jet leads to fine sprays of remarkable quality. Here we describe the joint effect of pressurization and electrification in a flow focusing device, and the subsequent coupling of both ES and FF phenomena. For any given liquid and flow rate, the combined procedure gives rise to significantly smaller droplet sizes than observed in any of the source techniques. The co-flowing gas stream removes space charges; in addition, the perforated plate facing the feed tube provides an electric barrier, shielding the jet-meniscus or ‘production’ area from the spray or ‘product’ area. As a result, space charges and electrified droplets are removed from the production area, thus avoiding the ambient electric saturation which becomes a limiting factor in ES-spraying: a significantly enhanced spraying stability ensues, with a much wider operation range than FF or ES. Other unexpected outcomes from the combination are also shown. A theoretical model is developed to predict the emitted droplet size: a first integral of the momentum equation yielding a generalized Bernoulli equation, and an explicit approximation for the jet diameter and droplet size, accurate within a broad parametrical band.

Injecting drug use in prison: prevalence and implications for needle exchange policy.

Science.gov (United States)

Wright, Nat M J; Tompkins, Charlotte N E; Farragher, Tracey M

2015-01-01

The purpose of this paper is to explore prison drug injecting prevalence, identify any changes in injecting prevalence and practice during imprisonment and explore views on prison needle exchange. An empirical prospective cohort survey conducted between 2006 and 2008. The study involved a random sample of 267 remand and sentenced prisoners from a large male category B prison in England where no prison needle exchange operates. Questionnaires were administered with prisoners on reception and, where possible, at one, three and six months during their sentence. In total, 64 per cent were injecting until admission into prison. The majority intended to stop injecting in prison (93 per cent), almost a quarter due to the lack of needle exchange (23 per cent). Yet when hypothetically asked if they would continue injecting in prison if needle exchange was freely available, a third of participants (33 per cent) believed that they would. Injecting cessation happened on prison entry and appeared to be maintained during the sentence. Not providing sterile needles may increase risks associated with injecting for prisoners who continue to inject. However, providing such equipment may prolong injecting for other prisoners who currently cease injecting on account of needle exchange programmes (NEPs) not being provided in the UK prison setting. Practical implications - Not providing sterile needles may increase risks associated with injecting for prisoners who continue to inject. However, providing such equipment may prolong injecting for other prisoners who currently cease injecting on account of NEPs not being provided in the UK prison setting. This survey is the first to question specifically regarding the timing of injecting cessation amongst male prisoners and explore alongside intention to inject should needle exchange facilities be provided in prison.

Analyzing Internal Fragmentation of Electrosprayed Ubiquitin Ions During Beam-Type Collisional Dissociation

Science.gov (United States)

Durbin, Kenneth R.; Skinner, Owen S.; Fellers, Ryan T.; Kelleher, Neil L.

2015-05-01

Gaseous fragmentation of intact proteins is multifaceted and can be unpredictable by current theories in the field. Contributing to the complexity is the multitude of precursor ion states and fragmentation channels. Terminal fragment ions can be re-fragmented, yielding product ions containing neither terminus, termed internal fragment ions. In an effort to better understand and capitalize upon this fragmentation process, we collisionally dissociated the high (13+), middle (10+), and low (7+) charge states of electrosprayed ubiquitin ions. Both terminal and internal fragmentation processes were quantified through step-wise increases of voltage potential in the collision cell. An isotope fitting algorithm matched observed product ions to theoretical terminal and internal fragment ions. At optimal energies for internal fragmentation of the 10+, nearly 200 internal fragments were observed; on average each of the 76 residues in ubiquitin was covered by 24.1 internal fragments. A pertinent finding was that formation of internal ions occurs at similar energy thresholds as terminal b- and y-ion types in beam-type activation. This large amount of internal fragmentation is frequently overlooked during top-down mass spectrometry. As such, we present several new approaches to visualize internal fragments through modified graphical fragment maps. With the presented advances of internal fragment ion accounting and visualization, the total percentage of matched fragment ions increased from approximately 40% to over 75% in a typical beam-type MS/MS spectrum. These sequence coverage improvements offer greater characterization potential for whole proteins with no needed experimental changes and could be of large benefit for future high-throughput intact protein analysis.

Reliability of supply of switchgear for auxiliary low voltage in substations extra high voltage to high voltage

Directory of Open Access Journals (Sweden)

Perić Dragoslav M.

2015-01-01

Full Text Available Switchgear for auxiliary low voltage in substations (SS of extra high voltages (EHV to high voltage (HV - SS EHV/HV kV/kV is of special interest for the functioning of these important SS, as it provides a supply for system of protection and other vital functions of SS. The article addresses several characteristic examples involving MV lines with varying degrees of independence of their supply, and the possible application of direct transformation EHV/LV through special voltage transformers. Auxiliary sources such as inverters and diesel generators, which have limited power and expensive energy, are also used for the supply of switchgear for auxiliary low voltage. Corresponding reliability indices are calculated for all examples including mean expected annual engagement of diesel generators. The applicability of certain solutions of switchgear for auxiliary low voltage SS EHV/HV, taking into account their reliability, feasibility and cost-effectiveness is analyzed too. In particular, the analysis of applications of direct transformation EHV/LV for supply of switchgear for auxiliary low voltage, for both new and existing SS EHV/HV.

Charge-pump voltage converter

Science.gov (United States)

Brainard, John P [Albuquerque, NM; Christenson, Todd R [Albuquerque, NM

2009-11-03

A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

High voltage systems

International Nuclear Information System (INIS)

Martin, M.

1991-01-01

Industrial processes usually require electrical power. This power is used to drive motors, to heat materials, or in electrochemical processes. Often the power requirements of a plant require the electric power to be delivered at high voltage. In this paper high voltage is considered any voltage over 600 V. This voltage could be as high as 138,000 V for some very large facilities. The characteristics of this voltage and the enormous amounts of power being transmitted necessitate special safety considerations. Safety must be considered during the four activities associated with a high voltage electrical system. These activities are: Design; Installation; Operation; and Maintenance

Electrospray mass spectrometry for actinides and lanthanide speciation

International Nuclear Information System (INIS)

Moulin, C.; Amekraz, B.; Colette, S.; Doizi, D.; Jacopin, C.; Lamouroux, C.; Plancque, G.

2006-01-01

Electrospray mass spectrometry (ES-MS) is a new speciation technique that has the great interest to be able to probe the element, the ligand and the complex in order to reach the speciation. This paper will focus on the use of ES-MS for the speciation of actinides/lanthanides on several systems of interest in various fields such as the interaction between DTPA (decorporant) and europium, HEBP and uranium, BTP (new extracting agent) and lanthanides with comparison with known chemistry as well as whenever possible with other speciation techniques

Dry needling and exercise for chronic whiplash - a randomised controlled trial

Directory of Open Access Journals (Sweden)

Souvlis Tina

2009-12-01

Full Text Available Abstract Background Chronic whiplash is a common and costly problem. Sensory hypersensitivity is a feature of chronic whiplash that is associated with poor responsiveness to physical treatments such as exercise. Modalities such as dry-needling have shown some capacity to modulate sensory hypersensitivity, suggesting that when combined with advice and exercise, such an approach may be more effective in the management of chronic whiplash. The primary aim of this project is to investigate the effectiveness of dry-needling, advice and exercise for chronic whiplash. Method/Design A double-blind randomised controlled trial will be conducted. 120 participants with chronic whiplash, grade II will be randomised to receive either 1 dry-needling, advice and exercise or 2 sham dry-needling, advice and exercise. All participants will receive an educational booklet on whiplash. Participants who are randomised to Group 1 will receive 6 treatments of combined dry-needling and exercise delivered in the first 3 weeks of the 6 week program, and 4 treatments of exercise only in the last 3 weeks of the program. Participants randomised to Group 2 will receive an identical protocol, except that a sham dry-needling technique will be used instead of dry-needling. The primary outcome measures are the Neck Disability Index (NDI and participants' perceived recovery. Outcomes will be measured at 6, 12, 24 and 52 weeks after randomization by an assessor who is blind to the group allocation of the participants. In parallel, an economic analysis will be conducted. Discussion This trial will utilise high quality trial methodologies in accordance with CONSORT guidelines. The successful completion of this trial will provide evidence of the effectiveness and cost-effectiveness of a combined treatment approach for the management of chronic whiplash. Trial registration ACTRN12609000470291

MAINTENANCE PLANNING OF THE SEWING NEEDLES OF SIMPLE SEWING MACHINES

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ŞUTEU Marius Darius

2017-05-01

Full Text Available The effectiveness of simple sewing machines can be increased through the planning of predictive maintenance activities. The monitoring of the technical condition of the sewing needles of simple sewing machines was based on the measurement of their noise level. For this purpose a Center 322 sonometer was used, while the data obtained during the monitoring process was analyzed through the E322 software. The working speed of the simple sewing machine that was used for obtaining the experimental results varied from 200 stitches/minute to 4000 stitches/minute. The noise levels of a new needle at the working speed of 200 stitches/minute and 4000 stitches/minute were measured. The noise levels for a fault needle at the same working speed of 200 stitches/minute, respectively 4000 stitches/minute were also measured. Using Fuzzy Logic Toolbox ™ module of Matlab®, a decision-making system for determining when replacement of the sewing needles of simple sewing machines should be performed was developed. A case study illustrates the employment of the decision-making system based on fuzzy logic for a simple sewing machine. By replacing the sewing needles of simple sewing machines at the time specified through the decision-making system based on fuzzy logic, the occurrence of the failure can be prevented and the quality of textile products can be improved.

Percutaneous Emergency Needle Caecostomy for Prevention of Caecal Perforation.

Science.gov (United States)

Limmer, Alexandra M; Clement, Zackariah

2017-01-01

Caecal perforation is a life-threatening complication of large bowel obstruction with a reported mortality of 34% to 72%. This case describes the novel use of percutaneous needle caecostomy as a life-saving measure to prevent imminent caecal perforation in a 68-year-old lady with large bowel obstruction secondary to an incarcerated incisional hernia. After careful review of computed tomography images and measurement of distances from the abdominal wall to the caecum, the patient's caecum was decompressed in the emergency department using a needle under local anaesthetic. The patient subsequently underwent laparoscopic hernia repair and had an uncomplicated recovery. When conducted safely and with precision in an appropriate patient, percutaneous needle caecostomy can provide immediate symptom relief, reduce risk of caecal perforation, and allow a laparoscopic surgical approach.

Percutaneous Emergency Needle Caecostomy for Prevention of Caecal Perforation

Directory of Open Access Journals (Sweden)

Alexandra M. Limmer

2017-01-01

Full Text Available Caecal perforation is a life-threatening complication of large bowel obstruction with a reported mortality of 34% to 72%. This case describes the novel use of percutaneous needle caecostomy as a life-saving measure to prevent imminent caecal perforation in a 68-year-old lady with large bowel obstruction secondary to an incarcerated incisional hernia. After careful review of computed tomography images and measurement of distances from the abdominal wall to the caecum, the patient’s caecum was decompressed in the emergency department using a needle under local anaesthetic. The patient subsequently underwent laparoscopic hernia repair and had an uncomplicated recovery. When conducted safely and with precision in an appropriate patient, percutaneous needle caecostomy can provide immediate symptom relief, reduce risk of caecal perforation, and allow a laparoscopic surgical approach.

Optical and magnetic properties of porous graphene films produced by electrospraying

International Nuclear Information System (INIS)

Zhao, Jun; Yang, Shan-Shan; Chen, Li-Qing; Zhang, Zhao-Chun; Zheng, Hou-Li

2013-01-01

Graphene films have been produced by electrospraying on SiO 2 -coated silicon substrate and subsequent heat treatment, offering a simple and typical method to produce porous graphene films and exhibiting a good adhesion to silicon substrate. The microstructures of as-prepared graphene films were characterized by field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction and atomic force microscopy. X-ray photoelectron spectroscopy, infrared spectroscopy and Raman spectroscopy further confirmed the formation of porous graphene films. Moreover, the reflection spectrum of as-prepared graphene films was studied by ultraviolet–visible spectroscopy, revealing that light absorption played dominant roles at 375 and 635 nm, respectively. Finally, the resistance and magnetoresistance were measured, and some preliminary theoretical explanations were proposed. - Highlights: ► Porous graphene films were produced by electrospraying. ► Light absorption plays dominant roles at 375 and 635 nm. ► A negative magnetoresistance is emerged at low temperature. ► A 2D weak localization effect arises from random stacking of graphene

Clinical application of percutaneous needling lung abscess drairnage under CT guidance

International Nuclear Information System (INIS)

Hu Xiaokun; Wang Mingyou; Li Chenjun; Lv Dongfang; Li Xiaodong; Yu Zhaocun

2004-01-01

Objective: To discuss the clinical application of drainage for lung abscess by needle puncture under CT guidance. Methods: 18 cases of lung abscess were drainaged by needle puncture under CT guidance, including direct aspiration by puncture needle 1-3 times (n=8) and retaining drainage tube continuously (n=10). Results: 17 cases with this procedure were succeeded possessing success rate of 94.7%(17/18). The patients were followed up for 11-35 days with symptom relieving better obviously and the focus shrinkage or disappeared (n=16), the curative rate reached 88.9%(16/18). The main complication was pneumothorax with capacities of 30%(n=1). Conclusions: The curative course of lung abscess can be shortened greatly by percutaneous needling drainage under CT guidance with mild trauma. The procedure is simple with high successful rate and less complication. (authors)

Dynamics of Pinus sylvestris L. needles activity in Predbaikal’ye forests

Directory of Open Access Journals (Sweden)

I.M. Romanova

2013-11-01

Full Text Available The study was aimed to analyse changes in peroxidase activity of common pine needles throughout the year. The needles of the 1-st, 2-nd and 3-d years were collected. Total activity of guaiacol-dependent peroxidase was determined. Minimum peroxidase activity is observed in January and February. In March intense overall activation of peroxidase is observed in the needles of all ages, which might be related to spring enhancement of physiological processes and activation of metabolism. Autumn period is characterized by more or less high activities of guaiacol peroxidase from September till November, which is related to its participation in stress-adaptation to low temperatures in winter. Peroxidase activity changes depending on the season of the year. Needles of different age are characterized by their own peroxidase activity level in various time periods.

A novel technique of rotator cuff repair using spinal needle and suture loop

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Muzaffar Nasir

2010-11-01

Full Text Available Abstract Background We present a simple technique of arthroscopic rotator cuff repair using a spinal needle and suture loop. Methods With the arthroscope laterally, a spinal needle looped with PDS is inserted percutaneously into the shoulder posteriorly and penetrated through the healthy posterior cuff tear margin. Anteriorly, another spinal needle loaded with PDS is inserted percutaneously to engage the healthy tissue at the anterior tear margin. The suture in the anterior needle is then delivered into the suture loop of the posterior needle using a suture retriever. The posterior needle and loop are then pulled out carrying the anterior suture with it. The two limbs of this suture are then retrieved through a cannula for knotting. The same procedure is then repeated for additional suturing. Suture anchors placed over the greater tuberosity are used to complete the repair. Conclusion This is an easy method of rotator cuff repair using simple instruments and lesser time, hence can be employed at centers with less equipment and at reduced cost to the patient.

Pen needle design influences ease of insertion, pain, and skin trauma in subjects with type 2 diabetes.

Science.gov (United States)

Præstmark, Kezia A; Jensen, Morten L; Madsen, Nils B; Kildegaard, Jonas; Stallknecht, Bente M

2016-01-01

Pen needles used for subcutaneous injections have gradually become shorter, thinner and more thin walled, and thereby less robust to patient reuse. Thus, different needle sizes, alternative tip designs and needles resembling reuse were tested to explore how needle design influences ease of insertion, pain and skin trauma. 30 subjects with injection-treated type 2 diabetes and body mass index 25-35 kg/m 2 were included in the single-blinded study. Each subject received abdominal insertions with 18 different types of needles. All needles were tested twice per subject and in random order. Penetration force (PF) through the skin, pain perception on 100 mm visual analog scale, and change in skin blood perfusion (SBP) were quantified after the insertions. Needle diameter was positively related to PF and SBP (ptrend relation. Lack of needle lubrication and small 'needle hooks' increased PF and SBP (pskin and in polyurethane rubber were linearly related, and pain outcome was dependent of SBP increase. The shape and design of a needle and the needle tip affect ease of insertion, pain and skin trauma. Relations are seen across different data acquisition methods and across species, enabling needle performance testing outside of clinical trials. NCT02531776; results.

Nano-slit electrospray emitters fabricated by a micro- to nanofluidic via technology

NARCIS (Netherlands)

Dijkstra, Marcel; Berenschot, Johan W.; de Boer, Meint J.; van der Linden, H.J.; Hankemeier, T.; Lammerink, Theodorus S.J.; Wiegerink, Remco J.; Elwenspoek, Michael Curt; Tas, Niels Roelof

2012-01-01

This article presents nano-slit electrospray emitters fabricated by a micro- to nanofluidic via technology. The main advantage of the technology is the ability to position freely suspended nanochannels anywhere on a microfluidic chip, where leak-tight delivery of fluid from a fluid reservoir can be

Target motion predictions for pre-operative planning during needle-based interventions

NARCIS (Netherlands)

op den Buijs, J.; Abayazid, Momen; de Korte, Chris L.; Misra, Sarthak

During biopsies, breast tissue is subjected to displacement upon needle indentation, puncture, and penetration. Thus, accurate needle placement requires pre-operative predictions of the target motions. In this paper, we used ultrasound elastography measurements to non-invasively predict elastic

The common structural architecture of Shigella flexneri and Salmonella typhimurium type three secretion needles.

Directory of Open Access Journals (Sweden)

Jean-Philippe Demers

2013-03-01

Full Text Available The Type Three Secretion System (T3SS, or injectisome, is a macromolecular infection machinery present in many pathogenic Gram-negative bacteria. It consists of a basal body, anchored in both bacterial membranes, and a hollow needle through which effector proteins are delivered into the target host cell. Two different architectures of the T3SS needle have been previously proposed. First, an atomic model of the Salmonella typhimurium needle was generated from solid-state NMR data. The needle subunit protein, PrgI, comprises a rigid-extended N-terminal segment and a helix-loop-helix motif with the N-terminus located on the outside face of the needle. Second, a model of the Shigella flexneri needle was generated from a high-resolution 7.7-Å cryo-electron microscopy density map. The subunit protein, MxiH, contains an N-terminal α-helix, a loop, another α-helix, a 14-residue-long β-hairpin (Q51-Q64 and a C-terminal α-helix, with the N-terminus facing inward to the lumen of the needle. In the current study, we carried out solid-state NMR measurements of wild-type Shigella flexneri needles polymerized in vitro and identified the following secondary structure elements for MxiH: a rigid-extended N-terminal segment (S2-T11, an α-helix (L12-A38, a loop (E39-P44 and a C-terminal α-helix (Q45-R83. Using immunogold labeling in vitro and in vivo on functional needles, we located the N-terminus of MxiH subunits on the exterior of the assembly, consistent with evolutionary sequence conservation patterns and mutagenesis data. We generated a homology model of Shigella flexneri needles compatible with both experimental data: the MxiH solid-state NMR chemical shifts and the state-of-the-art cryoEM density map. These results corroborate the solid-state NMR structure previously solved for Salmonella typhimurium PrgI needles and establish that Shigella flexneri and Salmonella typhimurium subunit proteins adopt a conserved structure and orientation in their

WE-G-204-08: Optimized Digital Radiographic Technique for Lost Surgical Devices/Needle Identification

International Nuclear Information System (INIS)

Gorman, A; Seabrook, G; Brakken, A; Dubois, M; Marn, C; Wilson, C; Jacobson, D; Liu, Y

2015-01-01

Purpose: Small surgical devices and needles are used in many surgical procedures. Conventionally, an x-ray film is taken to identify missing devices/needles if post procedure count is incorrect. There is no data to indicate smallest surgical devices/needles that can be identified with digital radiography (DR), and its optimized acquisition technique. Methods: In this study, the DR equipment used is a Canon RadPro mobile with CXDI-70c wireless DR plate, and the same DR plate on a fixed Siemens Multix unit. Small surgical devices and needles tested include Rubber Shod, Bulldog, Fogarty Hydrogrip, and needles with sizes 3-0 C-T1 through 8-0 BV175-6. They are imaged with PMMA block phantoms with thickness of 2–8 inch, and an abdomen phantom. Various DR techniques are used. Images are reviewed on the portable x-ray acquisition display, a clinical workstation, and a diagnostic workstation. Results: all small surgical devices and needles are visible in portable DR images with 2–8 inch of PMMA. However, when they are imaged with the abdomen phantom plus 2 inch of PMMA, needles smaller than 9.3 mm length can not be visualized at the optimized technique of 81 kV and 16 mAs. There is no significant difference in visualization with various techniques, or between mobile and fixed radiography unit. However, there is noticeable difference in visualizing the smallest needle on a diagnostic reading workstation compared to the acquisition display on a portable x-ray unit. Conclusion: DR images should be reviewed on a diagnostic reading workstation. Using optimized DR techniques, the smallest needle that can be identified on all phantom studies is 9.3 mm. Sample DR images of various small surgical devices/needles available on diagnostic workstation for comparison may improve their identification. Further in vivo study is needed to confirm the optimized digital radiography technique for identification of lost small surgical devices and needles

Electrospray ionization and matrix assisted laser desorption/ionization mass spectrometry: powerful analytical tools in recombinant protein chemistry

DEFF Research Database (Denmark)

Andersen, Jens S.; Svensson, B; Roepstorff, P

1996-01-01

Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy is presen......Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy...... is presented encompassing protein characterization prior to and after cloning of the corresponding gene....

Determining the Optimal Number of Core Needle Biopsy Passes for Molecular Diagnostics.

Science.gov (United States)

Hoang, Nam S; Ge, Benjamin H; Pan, Lorraine Y; Ozawa, Michael G; Kong, Christina S; Louie, John D; Shah, Rajesh P

2018-03-01

The number of core biopsy passes required for adequate next-generation sequencing is impacted by needle cut, needle gauge, and the type of tissue involved. This study evaluates diagnostic adequacy of core needle lung biopsies based on number of passes and provides guidelines for other tissues based on simulated biopsies in ex vivo porcine organ tissues. The rate of diagnostic adequacy for pathology and molecular testing from lung biopsy procedures was measured for eight operators pre-implementation (September 2012-October 2013) and post-implementation (December 2013-April 2014) of a standard protocol using 20-gauge side-cut needles for ten core biopsy passes at a single academic hospital. Biopsy pass volume was then estimated in ex vivo porcine muscle, liver, and kidney using side-cut devices at 16, 18, and 20 gauge and end-cut devices at 16 and 18 gauge to estimate minimum number of passes required for adequate molecular testing. Molecular diagnostic adequacy increased from 69% (pre-implementation period) to 92% (post-implementation period) (p < 0.001) for lung biopsies. In porcine models, both 16-gauge end-cut and side-cut devices require one pass to reach the validated volume threshold to ensure 99% adequacy for molecular characterization, while 18- and 20-gauge devices require 2-5 passes depending on needle cut and tissue type. Use of 20-gauge side-cut core biopsy needles requires a significant number of passes to ensure diagnostic adequacy for molecular testing across all tissue types. To ensure diagnostic adequacy for molecular testing, 16- and 18-gauge needles require markedly fewer passes.

Use of a Puncture Needle for Recanalization of an Occluded Right Subclavian Vein

International Nuclear Information System (INIS)

Gupta, Himanshu; Murphy, Timothy P.; Soares, Gregory M.

1998-01-01

We report a patient in whom we used a puncture needle to initiate percutaneous recanalization of a chronic occlusion of the junction between the right subclavian vein and the right brachiocephalic vein. Under fluoroscopic guidance, an 18-gauge needle was used to puncture the right subclavian vein. When contrast material injected through the needle confirmed intravascular location, the needle was advanced until it deflected and perforated an occlusion balloon target positioned within the right brachiocephalic vein. This technique may be useful in patients with central venous occlusions that are refractory to traversal using traditional catheter and guidewire techniques

Clarification of the characteristics of needle-tip movement during vacuum venipuncture to improve safety

Directory of Open Access Journals (Sweden)

Fujii C

2013-07-01

Full Text Available Chieko FujiiFaculty of Nursing and Medical Care, Keio University, Kanagawa, JapanBackground: Complications resulting from venipuncture include vein and nerve damage, hematoma, and neuropathic pain. Although the basic procedures are understood, few analyses of actual data exist. It is important to improve the safety standards of this technique during venipuncture. This study aimed to obtain data on actual needle movement during vacuum venipuncture in order to develop appropriate educational procedures.Methods: Six experienced nurses were recruited to collect blood samples from 64 subjects. These procedures were recorded using a digital camera. Software was then used to track and analyze motion without the use of a marker in order to maintain the sterility of the needle. Movement along the X- and Y-axes during blood sampling was examined.Results: Approximately 2.5 cm of the needle was inserted into the body, of which 6 mm resulted from advancing or moving the needle following puncture. The mean calculated puncture angle was 15.2°. Given the hazards posed by attaching and removing the blood collection tube, as well as by manipulating the needle to fix its position, the needle became unstable whether it was fixed or not fixed.Conclusion: This study examined venipuncture procedures and showed that the method was influenced by increased needle movement. Focusing on skills for puncturing the skin, inserting the needle into the vein, and changing hands while being conscious of needle-tip stability may be essential for improving the safety of venipuncture.Keywords: blood collection, nerve damage, motion analysis, patient safety, puncture angle, clinical education

Detection of needle to nerve contact based on electric bioimpedance and machine learning methods.

Science.gov (United States)

Kalvoy, Havard; Tronstad, Christian; Ullensvang, Kyrre; Steinfeldt, Thorsten; Sauter, Axel R

2017-07-01

In an ongoing project for electrical impedance-based needle guidance we have previously showed in an animal model that intraneural needle positions can be detected with bioimpedance measurement. To enhance the power of this method we in this study have investigated whether an early detection of the needle only touching the nerve also is feasible. Measurement of complex impedance during needle to nerve contact was compared with needle positions in surrounding tissues in a volunteer study on 32 subjects. Classification analysis using Support-Vector Machines demonstrated that discrimination is possible, but that the sensitivity and specificity for the nerve touch algorithm not is at the same level of performance as for intra-neuralintraneural detection.

Effect of dietary mugwort ( Artemisia vulgaris L.) and pine needle ...

African Journals Online (AJOL)

The effects of dietary mugwort and pine needle powder supplementation on growth performance, serum cholesterol, and meat quality of broilers were evaluated in a 35 days feed trial. 200 one day old broilers were randomly allocated to five dietary treatments (0, 1 and 2% mugwort or 1 and 2% pine needle powder) with ...

Carbon fibre and nitinol needles for MRI-guided interventions: First in vitro and in vivo application

Energy Technology Data Exchange (ETDEWEB)

Thomas, Christoph, E-mail: Christoph.thomas@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Wojtczyk, Hanne [Section of Experimental Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Rempp, Hansjoerg; Clasen, Stephan; Horger, Marius [Department of Diagnostic and Interventional Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Lassberg, Christoph von [Department of Sports Medicine, University of Tuebingen, Silcherstrasse 5, 72076 Tuebingen (Germany); Fritz, Jan [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287 (United States); Claussen, Claus D. [Department of Diagnostic and Interventional Radiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Pereira, Philippe L. [Department of Radiology, Minimally Invasive Therapies and Nuclearmedicine, SLK-Kliniken Heilbronn GmbH, Am Gesundbrunnen 20-26, 74078 Heilbronn (Germany)

2011-09-15

Objective: To assess the artefact properties of a MR-compatible carbon fibre needle with a nitinol mandrin in vitro and to report first clinical experiences. Materials and methods: In vitro, the carbon fibre/nitinol needle was imaged at different angles against the main magnetic field (1.5 T open bore magnet). A gradient echo MR fluoroscopy sequence (GRE: TR 9.3 ms, TE 3.12 ms, bandwidth 200 Hz/pixel, flip-angle 12{sup o}) and a fast turbo spin echo sequence (FSE: TR 412 ms, TE 9.7 ms, bandwidth 200 Hz/pixel, flip-angle 150{sup o}) were used. Artefact width, needle intensity contrast and needle tip location errors were assessed. In vivo, lumbar periradicular corticosteroid injections and one sclerotherapy were performed with carbon fibre needles (10 procedures) and with titanium alloy needles (2 procedures). The artefact sizes and contrasts were measured. Results: In vitro, artefact diameters of the carbon fibre needle ranged from 3.3 to 4.6 mm, contrasts from 0.11 to 0.52, with larger artefact contrasts and widths with the GRE sequence. Needle tip location errors of -2.1 to -2.8 mm were observed. Decreasing angles to the main field lead to smaller artefacts. In vivo, the carbon fibre/nitinol needle produced smaller artefacts (mean width FSE/GRE: 2.8 mm/4.6 mm) with lower contrast (0.30-0.42) than the titanium alloy needle (mean width FSE/GRE: 4.1 mm/7.5 mm, contrast 0.60-0.73). Conclusions: The carbon fibre/nitinol needle is useful for performing MR-guided interventions at 1.5 T, producing more subtle artefacts than a titanium alloy needle, but with an incomplete depiction and thus inaccurate localization of the needle tip.

Negligible degradation upon in situ voltage cycling of a PEMFC using an electrospun niobium-doped tin oxide supported Pt cathode.

Science.gov (United States)

Savych, Iuliia; Subianto, Surya; Nabil, Yannick; Cavaliere, Sara; Jones, Deborah; Rozière, Jacques

2015-07-14

Novel platinum-catalysed, corrosion-resistant, loose-tube-structured electrocatalysts for proton exchange membrane fuel cells have been obtained using single-needle electrospinning associated with a microwave-assisted polyol method. Monodisperse platinum particles supported on Nb-SnO2 demonstrated higher electrochemical stability than conventional Pt/C electrodes during ex situ potential cycling and comparable activity in the oxygen reduction reaction. In situ fuel cell operation under accelerated stress test conditions of a membrane electrode assembly elaborated using a Pt/C anode and Pt/Nb-SnO2 cathode confirmed that the voltage loss is significantly lower for the novel cathode than for an MEA prepared using conventional Pt/C supported electrocatalysts. Furthermore, the Nb-SnO2 stabilised the supported platinum nanoparticles against dissolution, migration and reprecipitation in the membrane. Pt/Nb-SnO2 loose-tubes constitute a mitigation strategy for two known degradation mechanisms in PEMFC: corrosion of the carbon support at the cathode, and dissolution of Pt at high cell voltages.

Low-Energy Real-Time OS Using Voltage Scheduling Algorithm for Variable Voltage Processors

OpenAIRE

Okuma, Takanori; Yasuura, Hiroto

2001-01-01

This paper presents a real-time OS based on $ mu $ITRON using proposed voltage scheduling algorithm for variable voltage processors which can vary supply voltage dynamically. The proposed voltage scheduling algorithms assign voltage level for each task dynamically in order to minimize energy consumption under timing constraints. Using the presented real-time OS, running tasks with low supply voltage leads to drastic energy reduction. In addition, the presented voltage scheduling algorithm is ...

Force-Sensor-Based Estimation of Needle Tip Deflection in Brachytherapy

Directory of Open Access Journals (Sweden)

Thomas Lehmann

2013-01-01

in real time during needle insertion is the main contribution of this paper. The proposed approach solely relies on the measured forces and torques without a need for any other invasive/noninvasive sensing devices. A few mechanical models have been introduced previously regarding the way the forces are composed along the needle during insertion; we will compare our model to those approaches in terms of accuracy. In order to conduct experiments to verify the deflection model, a custom-built, 2-DOF robotic system for needle insertion is developed and discussed. This system is a prototype of an intelligent, hand-held surgical assistant tool that incorporates the virtual sensor proposed in this paper.

A plasma needle generates nitric oxide

International Nuclear Information System (INIS)

Stoffels, E; Gonzalvo, Y Aranda; Whitmore, T D; Seymour, D L; Rees, J A

2006-01-01

Generation of nitric oxide (NO) by a plasma needle is studied by means of mass spectrometry. The plasma needle is an atmospheric glow generated by a radio-frequency excitation in a mixture of helium and air. This source is used for the treatment of living tissues, and nitric oxide may be one of the most important active agents in plasma therapy. Efficient NO generation is of particular importance in the treatment of cardiovascular diseases. Mass spectrometric measurements have been performed under various plasma conditions; gas composition in the plasma and conversion of feed gases (nitrogen and oxygen) into other species has been studied. Up to 30% of the N 2 and O 2 input is consumed in the discharge, and NO has been identified as the main conversion product

Real-time image-based B-mode ultrasound image simulation of needles using tensor-product interpolation.

Science.gov (United States)

Zhu, Mengchen; Salcudean, Septimiu E

2011-07-01

In this paper, we propose an interpolation-based method for simulating rigid needles in B-mode ultrasound images in real time. We parameterize the needle B-mode image as a function of needle position and orientation. We collect needle images under various spatial configurations in a water-tank using a needle guidance robot. Then we use multidimensional tensor-product interpolation to simulate images of needles with arbitrary poses and positions using collected images. After further processing, the interpolated needle and seed images are superimposed on top of phantom or tissue image backgrounds. The similarity between the simulated and the real images is measured using a correlation metric. A comparison is also performed with in vivo images obtained during prostate brachytherapy. Our results, carried out for both the convex (transverse plane) and linear (sagittal/para-sagittal plane) arrays of a trans-rectal transducer indicate that our interpolation method produces good results while requiring modest computing resources. The needle simulation method we present can be extended to the simulation of ultrasound images of other wire-like objects. In particular, we have shown that the proposed approach can be used to simulate brachytherapy seeds.

Characterisation of bacteria by matrix-assisted laser desorption/ionisation and electrospray mass spectrometry

NARCIS (Netherlands)

Baar, B.L.M. van

2000-01-01

Chemical analysis for the characterisation of micro-organisms is rapidly evolving, after the recent advent of new ionisation methods in mass spectrometry (MS): electrospray (ES) and matrix-assisted laser desorption/ionisation (MALDI). These methods allow quick characterisation of micro-organisms,

Formation of ROS and RNS in Water Electro-Sprayed through Transient Spark Discharge in Air and their Bactericidal Effects

Czech Academy of Sciences Publication Activity Database

Machala, Z.; Tarabová, B.; Hensel, K.; Doležalová, Eva; Šikurová, L.; Lukeš, Petr

2013-01-01

Roč. 10, č. 7 (2013), s. 649-659 ISSN 1612-8850 R&D Projects: GA AV ČR IAAX00430802; GA ČR(CZ) GD104/09/H080; GA MŠk(CZ) MEB0810116 Institutional support: RVO:61389021 Keywords : Plasma electrospray * water * bacteria * hydrogen peroxide * peroxynitrite * cold plasma * water electro-spray Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.964, year: 2013 http://dx.doi.org/10.1002/ppap.201200113

Ultrasound-guided percutaneous core needle biopsy of splenic lesions

Energy Technology Data Exchange (ETDEWEB)

Park, SangIk; Shin, Yong Moon; Won, Hyung Jin; Kim, Pyo Nyun; Lee, Moon Gyu [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

2017-05-15

To evaluate the safety and efficacy of ultrasound-guided percutaneous core needle biopsy of splenic lesions. This retrospective study included 30 patients who underwent percutaneous core needle biopsy of their splenic lesions using 18- or 20-gauge needles between January 2001 and July 2016 in a single tertiary care center. The characteristics of the splenic lesions were determined by reviewing the ultrasound and computed tomography examinations. Acquisition rate and diagnostic accuracy were calculated, using pathologic results of the splenectomy specimen, clinical course and/or imaging follow-up as a reference standard. Post-procedure complications were identified from electronic medical records, laboratory findings and computed tomography images. Seventy-three specimens were obtained from the 30 patients and splenectomy was performed in 2 patients. Twenty-nine of the 30 patients had focal splenic lesions, while the remaining patient had homogeneous splenomegaly. Acquisition rate and diagnostic accuracy were 80.0% (24/30) and 76.7% (23/30), respectively. Perisplenic hemorrhage without hemodynamic instability developed in one patient. Ultrasound-guided percutaneous core needle biopsy of splenic lesions is a safe method for achieving a histopathologic diagnosis and can be considered as an alternative to splenectomy in patients with a high risk of splenectomy-related complications.

Ultrasound-guided percutaneous core needle biopsy of splenic lesions

International Nuclear Information System (INIS)

Park, SangIk; Shin, Yong Moon; Won, Hyung Jin; Kim, Pyo Nyun; Lee, Moon Gyu

2017-01-01

To evaluate the safety and efficacy of ultrasound-guided percutaneous core needle biopsy of splenic lesions. This retrospective study included 30 patients who underwent percutaneous core needle biopsy of their splenic lesions using 18- or 20-gauge needles between January 2001 and July 2016 in a single tertiary care center. The characteristics of the splenic lesions were determined by reviewing the ultrasound and computed tomography examinations. Acquisition rate and diagnostic accuracy were calculated, using pathologic results of the splenectomy specimen, clinical course and/or imaging follow-up as a reference standard. Post-procedure complications were identified from electronic medical records, laboratory findings and computed tomography images. Seventy-three specimens were obtained from the 30 patients and splenectomy was performed in 2 patients. Twenty-nine of the 30 patients had focal splenic lesions, while the remaining patient had homogeneous splenomegaly. Acquisition rate and diagnostic accuracy were 80.0% (24/30) and 76.7% (23/30), respectively. Perisplenic hemorrhage without hemodynamic instability developed in one patient. Ultrasound-guided percutaneous core needle biopsy of splenic lesions is a safe method for achieving a histopathologic diagnosis and can be considered as an alternative to splenectomy in patients with a high risk of splenectomy-related complications

[Effects of warm needling moxibustion on knee cartilage and morphology in rats with knee osteoarthritis].

Science.gov (United States)

Zhang, Yongliang; Mi, Yiqun; Gang, Jiahong; Wang, Huamin

2016-02-01

To observe the effects of warm needling moxibustion on body mass, knee cartilage andmorphology in rats with knee osteoarthritis (KOA). Forty SD rats were randomly divided into a normalgroup, a model group, a medication group and a warm needling group, 10 rats in each one. Except the normalgroup, the rats in the remaining three groups were injected with papain to establish the model of KOA. After themodeling, rats in the model group did not receive any treatment; rats in the warm needling group were treated withwarm needling moxibustion at bilateral "Xiqian"; rats in the medication group were treated with intragastric administration of meloxicam; rats in the normal group were treated with 0. 9% NaCl solution (identical dose as medication group) and immobilized as the warm needling group. The treatment was given once a day for consecutive20 days. The body mass, scale of knee cartilage and morphological changes were observed in each group after'treatment. The increasing of body mass in the medication group and warm needling group was faster than!that in the model group, but slower than that in the normal group (all Pwarm needling group was not statistically significant (P>0. 05). The scale of knee cartilage in thewarm needling group and medication group was significantly lower than that in the model group (both Pwarm needling group was lower than that in the medication group (Pwarm needlinggroup were superior to those in the medication group. The warm needling moxibustion could effectively reduce the knee pain, improve the recovery of knee cartilage, which is a safe and effective treatment.

What Protein Charging (and Supercharging) Reveal about the Mechanism of Electrospray Ionization

Science.gov (United States)

Ogorzalek Loo, Rachel R.; Lakshmanan, Rajeswari; Loo, Joseph A.

2014-10-01

Understanding the charging mechanism of electrospray ionization is central to overcoming shortcomings such as ion suppression or limited dynamic range, and explaining phenomena such as supercharging. Towards that end, we explore what accumulated observations reveal about the mechanism of electrospray. We introduce the idea of an intermediate region for electrospray ionization (and other ionization methods) to account for the facts that solution charge state distributions (CSDs) do not correlate with those observed by ESI-MS (the latter bear more charge) and that gas phase reactions can reduce, but not increase, the extent of charging. This region incorporates properties (e.g., basicities) intermediate between solution and gas phase. Assuming that droplet species polarize within the high electric field leads to equations describing ion emission resembling those from the equilibrium partitioning model. The equations predict many trends successfully, including CSD shifts to higher m/z for concentrated analytes and shifts to lower m/z for sprays employing smaller emitter opening diameters. From this view, a single mechanism can be formulated to explain how reagents that promote analyte charging ("supercharging") such as m-NBA, sulfolane, and 3-nitrobenzonitrile increase analyte charge from "denaturing" and "native" solvent systems. It is suggested that additives' Brønsted basicities are inversely correlated to their ability to shift CSDs to lower m/z in positive ESI, as are Brønsted acidities for negative ESI. Because supercharging agents reduce an analyte's solution ionization, excess spray charge is bestowed on evaporating ions carrying fewer opposing charges. Brønsted basicity (or acidity) determines how much ESI charge is lost to the agent (unavailable to evaporating analyte).