An ECG method for positioning the tip of a PICC in “mirror people” with dextrocardia: A case report

Intracavitary electrocardiogram (ECG) has been widely used for PICC tip positioning in patients with a normal left heart. However, there is little information about using ECG for PICC insertion in patients with mirror dextrocardia. We report a 70-year-old stomach cancer patient with mirror dextrocardia admitted to our vascular access center for four Fr silicon Groshong PICC insertion. We successfully performed an ultrasound-guided modified Seldinger technique for insertion. First, the usual standardized ECG technique was used for tip positioning, and it failed. Then, we changed the procedure slightly, using the opposite electrode connections (RA: the first intercostal space of the midline of the left clavicle; LA: the first intercostal space of the midline of the right clavicle; and LL: the inferior margin of the right costal arch) to obtain an evident P-wave change to guide catheter placement in this case. We confirm that we can use the opposite electrodes to obtain an apparent P-wave for locating the catheter tip in patients with mirror dextrocardia.

Monitoring metallic sub-micrometric lithium structures in Li-ion batteries by in situ electron paramagnetic resonance correlated spectroscopy and imaging

Monitoring the formation of dendrites or filaments of lithium is of paramount importance for Li-based battery technologies, hence the intense activities in designing in situ techniques to visualize their growth. Herein we report the benefit of correlating in situ electron paramagnetic resonance (EPR) spectroscopy and EPR imaging to analyze the morphology and location of metallic lithium in a symmetric Li/LiPF6/Li electrochemical cell during polarization. We exploit the variations in shape, resonance field and amplitude of the EPR spectra to follow, operando, the nucleation of sub-micrometric Li particles (narrow and symmetrical signal) that conjointly occurs with the fragmentation of bulk Li on the opposite electrode (asymmetrical signal). Moreover, in situ EPR correlated spectroscopy and imaging (spectral-spatial EPR imaging) allows the identification (spectral) and localization (spatial) of the sub-micrometric Li particles created by plating (deposition) or stripping (altered bulk Li surface). We finally demonstrate the possibility to visualize, via in situ EPR imaging, dendrites formed through the separator in the whole cell. Such a technique could be of great help in mastering the Li-electrolyte interface issues that plague the development of solid-state batteries.

In Situ Electron Paramagnetic Resonance Correlated Spectroscopy and Imaging: A Tool for Lithium-Ion Batteries to Investigate Metallic Lithium Sub-Micrometric Structures Created by Plating and Stripping

<div>Monitoring the formation of dendrites or filaments of lithium is of paramount importance</div><div>for Li-based battery technologies, hence the intense activities in designing in situ techniques</div><div>to visualize their growth. Herein we report the benefit of correlating in situ electron para4 magnetic resonance (EPR) spectroscopy and EPR imaging to analyze the morphology and</div><div>location of metallic lithium in a symmetric Li/LiPF6/Li electrochemical cell during polariza6 tion. We exploit the variations in shape, resonance field and amplitude of the EPR spectra</div><div>to follow, operando, the nucleation of sub-micrometric Li particles (narrow and symmetrical</div><div>signal) that conjointly occurs with the fragmentation of bulk Li on the opposite electrode</div><div>(asymmetrical signal). Moreover, in situ EPR correlated spectroscopy and imaging (spectral10 spatial EPR imaging) allows the identification (spectral) and localization (spatial) of the sub11 micrometric Li particles created by plating (deposition) or stripping (altered bulk Li surface).</div><div>We finally demonstrate the possibility to visualize, via in situ EPR imaging, dendrites formed</div><div>through the separator in the whole cell. Such a technique could be of great help in mastering</div><div>the Li-electrolyte interface issues that plague the development of solid-state batteries.</div>

In Situ Electron Paramagnetic Resonance Correlated Spectroscopy and Imaging: A Tool for Lithium-Ion Batteries to Investigate Metallic Lithium Sub-Micrometric Structures Created by Plating and Stripping

<div>Monitoring the formation of dendrites or filaments of lithium is of paramount importance</div><div>for Li-based battery technologies, hence the intense activities in designing in situ techniques</div><div>to visualize their growth. Herein we report the benefit of correlating in situ electron para4 magnetic resonance (EPR) spectroscopy and EPR imaging to analyze the morphology and</div><div>location of metallic lithium in a symmetric Li/LiPF6/Li electrochemical cell during polariza6 tion. We exploit the variations in shape, resonance field and amplitude of the EPR spectra</div><div>to follow, operando, the nucleation of sub-micrometric Li particles (narrow and symmetrical</div><div>signal) that conjointly occurs with the fragmentation of bulk Li on the opposite electrode</div><div>(asymmetrical signal). Moreover, in situ EPR correlated spectroscopy and imaging (spectral10 spatial EPR imaging) allows the identification (spectral) and localization (spatial) of the sub11 micrometric Li particles created by plating (deposition) or stripping (altered bulk Li surface).</div><div>We finally demonstrate the possibility to visualize, via in situ EPR imaging, dendrites formed</div><div>through the separator in the whole cell. Such a technique could be of great help in mastering</div><div>the Li-electrolyte interface issues that plague the development of solid-state batteries.</div>

P984Proof of endo-epicardial asynchrony of the left atrial wall in humans

Funding Acknowledgements Prof. Dr. NMS de Groot is supported by funding grants from CVON-AFFIP (914728), NWO-Vidi (91717339), Biosense Webster USA (ICD 783454) and Medical Del Introduction Treatment of atrial fibrillation (AF) is still suboptimal as mechanisms underlying AF initiation and persistence are incompletely understood. Endo-Epicardial asynchrony (EEA) plays an important role in AF persistence and has so far only been demonstrated in the right atrium (RA). Purpose To investigate whether EEA also exists in the thin walled left atrium (LA) and to measure the maximal degree of EEA between the endo- and epicardial layers during sinus rhythm (SR). Methods Simultaneous endo-epicardial mapping of the LA was performed during SR in 3 male patients (73 ± 1.5 years) with history of paroxysmal AF undergoing cardiac surgery including rhythm surgery and LA appendage amputation. Simultaneous endo-epicardial mapping was performed with a mapping clamp containing two electrode arrays of 8x16 electrodes (diameters: 0.4mm, interelectrode distance: 2mm) positioned exactly opposite to each other. The mapping clamp was introduced through the LA appendage with its tip towards the superior pulmonary vein. Local endo-epicardial activation time differences were determined by selecting the median time delay within the exact opposite electrode and its 8 surrounding electrodes. The asynchrony map consisted of the maximum of 2 medians from direct opposite electrodes. EEA was defined as time differences ≥15ms. Conduction delay (CD) and conduction block (CB) were defined as differences in local activation times between neighboring electrodes of respectively ≥7 and ≥12ms. Results A total of 35 SR beats were analyzed. Mean total activation time of the whole endo-epicardial LA tissue was 42.4 ± 9.5ms and did not differ between both layers (epicardium: 31.2 ± 9.9ms; endocardium: 37.8 ± 10.3ms; P= 0.62). CD and CB were observed in respectively 3.2% and 6.3% at the epicardium and 3.3% and 3.0% at the endocardium. The lowest amount of CD (5.2%) and CB (0.3%) was observed in the patient who had his first AF episode only 11 days prior to surgery. Also, no EEA was present in this patient. In two patients with paroxysmal AF &gt;6 months, the prevalence of EEA was respectively 2.7% and 41.4% and the degree of EEA ranged from 15 to 44ms. Interestingly, the patient with the highest degree of EEA was diagnosed with paroxysmal AF for almost 5 years (Figure 1). Conclusion Our data provides evidence for the existence of EEA in the human left atrium which appears to be already present during SR. Knowledge of EEA and the ability to stage AF based on the degree of EEA is essential for individualized and staged future therapy for AF. Abstract Figure 1. The maximal degree of endo-epi

SIMULATION OF METAL TRANSFER BETWEEN CYLINDRICAL ELECTRODES AT ELECTROSPARK ALLOYING

The work is dedicated to the simulation of the processes of erosion and electrode metal transfer at coating formation by an electrospark alloying method. Anode is a cylindrical rod, and cathode – a disk. During discharge pulses the erosion takes place both in anode material, and in cathode material. The anode moves in a spiral along a cathode surface. There are calculated the coefficients of precipitation equal to the probability of metal emitted from the surface of one electrode and falling onto the surface of the opposite electrode. They are constant close to the central cathode axis, but at the anode approach to the cathode end a coefficient of anode metal precipitation on a cathode decreases, a coefficient of cathode metal precipitation on an anode increases. The rates of anode erosion and cathode weight increase when the mass ratio of eroded substance of anode and cathode increases in the course of one discharge. When this ratio is equal to 5, a coefficient of mass transfer achieves 0.8-0.9 it tells of small substance loss during its transfer between electrodes. The model developed is useful for the parameter estimate of mass transfer between cylindrical electrodes at electrospark processing taking into ac-count their dimensions and paths of anode motion.

Flexible free-standing SU-8 microfluidic impedance spectroscopy sensor for 3-D molded interconnect devices application

The current contribution reports about the fabrication technology for the development of novel microfluidic impedance spectroscopy sensors that are directly attachable on 3-D molded interconnect devices (3D-MID) that provides an opportunity to create reduced-scale sensor devices for 3-D applications. Advantages of the MID technology in particular for an automotive industry application were recently discussed (Moser and Krause, 2006). An ability to integrate electrical and fluidic parts into the 3D-MID platform brings a sensor device to a new level of the miniaturization. The demonstrated sensor is made of a flexible polymer material featuring a system of electrodes that are structured on and embedded in the SU-8 polymer. The sensor chips can be directly soldered on the MID due to the electroless plated contact pads. A flip chip process based on the opposite electrode design and the implementation of all fluidic and electrical connections at one side of the sensors can be used to assemble the sensor to a three-dimensional substrate. The developed microfluidic sensor demonstrated a predictable impedance spectrum behavior and a sufficient sensitivity to the concentration of ethanol in deionized water. To the best of our knowledge, there is no report regarding such sensor fabrication technology.

Single molecule microscopy and spectroscopy: concluding remarks

Chemistry is all about molecules: control, synthesis, interaction and reaction of molecules. All too easily on a blackboard, one draws molecules, their structures and dynamics, to create an insightful picture. The dream is to see these molecules in reality. This is exactly what “Single Molecule Detection” provides: a look at molecules in action at ambient conditions; a breakthrough technology in chemistry, physics and biology. Within the realms of the Royal Society of Chemistry, the Faraday Discussion on “Single Molecule Microscopy and Spectroscopy” was a very appropriate topic for presentation, deliberation and debate. Undoubtedly, the Faraday Discussions have a splendid reputation in stimulating scientific debates along the traditions set by Michael Faraday. Interestingly, back in the 1830's, Faraday himself pursued an experiment that led to the idea that atoms in a compound were joined by an electrical component. He placed two opposite electrodes in a solution of water containing a dissolved compound, and observed that one of the elements of the compound accumulated on one electrode, while the other was deposited on the opposite electrode. Although Faraday was deeply opposed to atomism, he had to recognize that electrical forces were responsible for the joining of atoms. Probably a direct view on the atoms or molecules in his experiment would have convinced him. As such, Michael Faraday might have liked the gathering at Burlington House in September 2015 (Fig. 1). Surely, with the questioning eyes of his bust on the 1st floor corridor, the non-believer Michael Faraday has incited each passer-by to enter into discussion and search for deeper answers at the level of single molecules. In these concluding remarks, highlights of the presented papers and discussions are summarized, complemented by a conclusion on future perspectives.The Royal Society of Chemistry at Burlington House in London. The entrance and the stained glass window on the stairway towards the first floor corridor where one finds the bronze bust representing Michael Faraday, protagonist of the early-day lively scientific discussions, which have inspired the “Faraday Discussions”.

Three Dimensional Bacteria Concentration by Negative Dielectrophoresis

Thispaper reports a novel method to concentrate bacteria in three-dimension by negative dielectrophoretic (n-DEP) force in a microchannel. This was achieved by placing a thin dielectric layer on one of a pair of parallel plate electrodes. The dielectric layer having a home-plate like pentagonal shape, forms a gradient of electric field causing n-DEP. A three-dimensional numerical simulation of bacteria trajectory predicts that bacteria flowing a microchannel were three-dimensionally concentrated beneath the tip of the pentagonal dielectric thin layer. The trajectory and concentration of bacteria under n-DEP force were also experimentally confirmed using Escherichia coli cells. Bacteria moved along edges of the dielectric layer and were pushed to the opposite electrode, resulting in their concentration in three-dimension. The proposed device might be applicable to selective concentration of bacteria depending on their dielectric properties.