Journal articles: 'MV contactor'

1

Firsching, Ruth, Christian J. Buchholz, Urs Schneider, Roberto Cattaneo, Volker ter Meulen, and Jürgen Schneider-Schaulies. "Measles Virus Spread by Cell-Cell Contacts: Uncoupling of Contact-Mediated Receptor (CD46) Downregulation from Virus Uptake." Journal of Virology 73, no. 7 (July 1, 1999): 5265–73. http://dx.doi.org/10.1128/jvi.73.7.5265-5273.1999.

Full text

Abstract:

ABSTRACT CD46, which serves as a receptor for measles virus (MV; strain Edmonston), is rapidly downregulated from the cell surface after contact with viral particles or infected cells. We show here that the same two CD46 complement control protein (CCP) domains responsible for primary MV attachment mediate its downregulation. Optimal downregulation efficiency was obtained with CD46 recombinants containing CCP domains 1 and 2, whereas CCP 1, alone and duplicated, induced a slight downregulation. Using persistently infected monocytic/promyelocytic U937 cells which release very small amounts of infectious virus, and uninfected HeLa cells as contact partners, we then showed that during contact the formation of CD46-containing patches and caps precedes CD46 internalization. Nevertheless, neither substances inhibiting capping nor the fusion-inhibiting peptide Z-d-Phe-l-Phe-Gly-OH (FIP) blocked CD46 downregulation. Thus, CD46 downregulation can be uncoupled from fusion and subsequent virus uptake. Interestingly, in that system cell-cell contacts lead to a remarkably efficient infection of the target cells which is only partially inhibited by FIP. The finding that the contact of an infected with uninfected cells results in transfer of infectious viral material without significant (complete) fusion of the donor with the recipient cell suggests that microfusion events and/or FIP-independent mechanisms may mediate the transfer of MV infectivity from cell to cell.

APA, Harvard, Vancouver, ISO, and other styles

2

Neira Rairán, Rafael, Germán Rodríguez Martínez, Angela Silva Igua, Leonardo Arias Bernal, Martha Inirida Guerrero, and Clara Inés León Franco. "Estudio macro y microscópico de la tuberculosis aviar en un zoológico de la Sabana de Bogotá." Revista de Medicina Veterinaria, no. 12 (December 1, 2006): 7. http://dx.doi.org/10.19052/mv.2050.

Full text

Abstract:

A partir de diagnósticos histopatológicos de casos compatibles con procesos granulomatosos, emitidos por el Laboratorio de Histopatología de la Facultad de Medicina Veterinaria de la Universidad de La Salle en un alcaraván (Burhinus bistriatus) y en dos tinguas azules (Porphyrula martinica), procedentes de un zoológico de la Sabana de Bogotá, se diseñó una investigación con el fin de comprobar la presencia de Mycobacterium avium, realizar un seguimiento epidemiológico de la población aviar existente en un encierro mixto silvestre y proyectar las medidas para reducir los factores de riesgo, tanto para los animales como para las personas. Se utilizó un grupo control de cinco aves domésticas raza Hy line Brown, un grupo centinela de diez aves del mismo lote del grupo control, un grupo control externo constituido por 102 aves de los encierros vecinos al área problema: 28 patos, 25 guacamayas, 26 loros, 23 aves rapaces y el grupo de aves del encierro problema. Se realizaron estudios retrospectivos y prospectivos mediante estudios morfológicos macro y microscópicos (Hematoxilina-Eosina y Ziehl-Neelsen). Con los estudios morfológicos se comprobó la presencia de lesiones granulomatosas en diversos órganos de los animales muertos de los grupos de aves centinela y del encierro problema, destacándose el hallazgo de lesiones granulomatosas en leptomeninges y sustancia blanca de la médula espinal y la mineralización (calcificación) en algunos granulomas, principalmente de hígado y pulmones. Con la coloración de Ziehl-Neelsen de los tejidos se comprobó la presencia de bacilos ácido-alcohol resistentes y se confirmó el diagnóstico de micobacteriosis en una de las aves centinela y en tres de las aves del encierro problema. Los animales de fuera del encierro no mostraron ningún indicio de enfermedad micobacteriana. Los hallazgos macro y microscópicos de los tejidos junto con los estudios microbiologicos y moleculares (no mostrados en este artículo) permiten concluir que el encierro problema se encuentra afectado por tuberculosis aviar causada por Mycobacterium avium principalmente, constituyéndose en un foco de alto riesgo para las aves de zoológico, silvestres y las comerciales eventualmente en contacto y un riesgo potencial para los humanos, por lo que se recomiendan medidas para su prevención, control y posible erradicación.

APA, Harvard, Vancouver, ISO, and other styles

3

Dong, Bingxu, Yan Jia, Qiaoyi Tan, Heyun Sun, and Renman Ruan. "Contributions of Microbial “Contact Leaching” to Pyrite Oxidation under Different Controlled Redox Potentials." Minerals 10, no. 10 (September 29, 2020): 856. http://dx.doi.org/10.3390/min10100856.

Full text

Abstract:

The function of microbial contact leaching to pyrite oxidation was investigated by analyzing the differences of residue morphologies, leaching rates, surface products, and microbial consortia under different conditions in this study. This was achieved by novel equipment that can control the redox potential of the solution and isolate pyrite from microbial contact oxidation. The morphology of residues showed that the corrosions were a little bit severer in the presence of attached microbes under 750 mV and 850 mV (vs. SHE). At 650 mV, the oxidation of pyrite was undetectable even in the presence of attached microbes. The pyrite dissolution rate was higher with attached microbes than that without attached microbes at 750 mV and 850 mV. The elemental sulfur on the surface of pyrite residues with sessile microorganisms was much less than that without attached microbes at 750 mV and 850 mV, showing that sessile acidophiles may accelerate pyrite leaching by reducing the elemental sulfur inhibition. Many more sulfur-oxidizers were found in the sessile microbial consortium which also supported the idea. The results suggest that the microbial “contact leaching” to pyrite oxidation is limited and relies on the elimination of elemental sulfur passivation by attached sulfur-oxidizing microbes rather than the contact oxidation by EPS-Fe.

APA, Harvard, Vancouver, ISO, and other styles

4

Ehrengruber, Markus U., Elisabeth Ehler, Martin A. Billeter, and Hussein Y. Naim. "Measles Virus Spreads in Rat Hippocampal Neurons by Cell-to-Cell Contact and in a Polarized Fashion." Journal of Virology 76, no. 11 (June 1, 2002): 5720–28. http://dx.doi.org/10.1128/jvi.76.11.5720-5728.2002.

Full text

Abstract:

ABSTRACT Measles virus (MV) can infect the central nervous system and, in rare cases, causes subacute sclerosing panencephalitis, characterized by a progressive degeneration of neurons. The route of MV transmission in neurons was investigated in cultured rat hippocampal slices by using MV expressing green fluorescent protein. MV infected hippocampal neurons and spread unidirectionally, in a retrograde manner, from CA1 to CA3 pyramidal cells and from there to the dentate gyrus. Spreading of infection depended on cell-to-cell contact and occurred without any detectable release of infectious particles. The role of the viral proteins in the retrograde MV transmission was determined by investigating their sorting in infected pyramidal cells. MV glycoproteins, the fusion protein (F) and hemagglutinin (H), the matrix protein (M), and the phosphoprotein (P), which is part of the viral ribonucleoprotein complex, were all sorted to the dendrites. While M, P, and H proteins remained more intracellular, the F protein localized to prominent, spine-type domains at the surface of infected cells. The detected localization of MV proteins suggests that local microfusion events may be mediated by the F protein at sites of synaptic contacts and is consistent with a mechanism of retrograde transmission of MV infection.

APA, Harvard, Vancouver, ISO, and other styles

5

Doiron, Curtis W., Nicholas A. Fitzpatrick, Clare P. Masucci, Julia L. Martin, Alexander D. Carl, and Ronald L. Grimm. "Open-Circuit Photovoltage Exceeding 950 mV with an 840 mV Average at Sb2S3–Thianthrene+/0 Junctions Enabled by Thioperylene Anhydride Back Contacts." ACS Omega 5, no. 27 (June 26, 2020): 16875–84. http://dx.doi.org/10.1021/acsomega.0c02077.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Guo, J. H., and J. E. Cotter. "Laser-Grooved Backside Contact Solar Cells With 680-mV Open-Circuit Voltage." IEEE Transactions on Electron Devices 51, no. 12 (December 2004): 2186–92. http://dx.doi.org/10.1109/ted.2004.839870.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Fjeld, Elin, Wilhelm Rondeel, Svein Thore Hagen, and Magne Saxegaard. "Estimating the temperature rise of load break switch contacts in enclosed MV switchgear." CIRED - Open Access Proceedings Journal 2017, no. 1 (October 1, 2017): 136–39. http://dx.doi.org/10.1049/oap-cired.2017.0349.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Erlenhoefer, Christian, Walter J. Wurzer, Sieglinde Löffler, Sibylle Schneider-Schaulies, Volker ter Meulen, and Jürgen Schneider-Schaulies. "CD150 (SLAM) Is a Receptor for Measles Virus but Is Not Involved in Viral Contact-Mediated Proliferation Inhibition." Journal of Virology 75, no. 10 (May 15, 2001): 4499–505. http://dx.doi.org/10.1128/jvi.75.10.4499-4505.2001.

Full text

Abstract:

ABSTRACT Measles virus (MV) interacts with cellular receptors on the surface of peripheral blood lymphocytes (PBL) which mediate virus binding and uptake. Simultaneously, the direct contact of the viral glycoproteins with the cell surface induces a negative signal blocking progression to the S phase of the cell cycle, resulting in a pronounced proliferation inhibition. We selected a monoclonal antibody (MAb 5C6) directed to the surface of highly MV-susceptible B cells (B95a), which inhibits binding to and infection of cells with MV wild-type and vaccine strains. By screening a retroviral cDNA library from human splenocytes (ViraPort; Stratagene) with this antibody, we cloned and identified the recognized molecule as signaling lymphocytic activation molecule (SLAM; CD150), which is identical to the MV receptor recently found by H. Tatsuo et al. (Nature 406:893–897, 2000). After infection of cells, and after surface contact with MV envelope proteins, SLAM is downregulated from the cell surface of activated PBL and cell lines. Although anti-SLAM and/or anti-CD46 antibodies block virus binding, they do not interfere with the contact-mediated proliferation inhibition. In addition, the cell-type-specific expression of SLAM does not correlate with the sensitivity of cells for proliferation inhibition. The data indicate that proliferation inhibition induced by MV contact is independent of the presence or absence of the virus-binding receptors SLAM and CD46.

APA, Harvard, Vancouver, ISO, and other styles

9

Sundaram, S., L. Irvine, J. M. Courtney, and G. D. O. Lowe. "Modification of the Influence of Biomaterials on Contact Activation." International Journal of Artificial Organs 14, no. 11 (November 1991): 729–31. http://dx.doi.org/10.1177/039139889101401109.

Full text

Abstract:

Knowledge of the influence of biomaterials on the contact phase activation of blood is important. Consequently, it is important to examine if the biomaterial influence is modified by the action of anticoagulants. Contact activation was determined by measuring FXII activity (FXIIA) by a chromogenic substrate assay. Cuprophan in the absence of anticoagulants and in the presence of heparin, low molecular weight heparin (LMWH) and hirudin was compared with controls. The controls were a polystyrene incubation test cell (PS) and two polyamide membranes, NR (zeta potential -28.6 mv and NRZ (zeta potential - 18.0 mv). The investigation has confirmed that measurement of FXIIA is material dependent and demonstrated that contact activation can be mediated by antithrombotic agent.

APA, Harvard, Vancouver, ISO, and other styles

10

Lawrence, Diane M. P., Catherine E. Patterson, Tracy L. Gales, Joseph L. D'Orazio, Melinda M. Vaughn, and Glenn F. Rall. "Measles Virus Spread between Neurons Requires Cell Contact but Not CD46 Expression, Syncytium Formation, or Extracellular Virus Production." Journal of Virology 74, no. 4 (February 15, 2000): 1908–18. http://dx.doi.org/10.1128/jvi.74.4.1908-1918.2000.

Full text

Abstract:

ABSTRACT In patients with subacute sclerosing panencephalitis (SSPE), which is associated with persistent measles virus (MV) infection in the brain, little infectious virus can be recovered despite the presence of viral RNA and protein. Based on studies of brain tissue from SSPE patients and our work with MV-infected NSE-CD46+ mice, which express the measles receptor CD46 on neurons, several lines of evidence suggest that the mechanism of viral spread in the central nervous system differs from that in nonneuronal cells. To examine this alternate mechanism of viral spread, as well as the basis for the loss of normal transmission mechanisms, infection and spread of MV Edmonston was evaluated in primary CD46+ neurons from transgenic mice and differentiated human NT2 neurons. As expected, unlike that between fibroblasts, viral spread between neurons occurred in the absence of syncytium formation and with minimal extracellular virus. Electron microscopy analysis showed that viral budding did not occur from the neuronal surface, although nucleocapsids were present in the cytoplasm and aligned at the cell membrane. We observed many examples of nucleocapsids present in the neuronal processes and aligned at presynaptic neuronal membranes. Cocultures of CD46+ and CD46− neurons showed that cell contact but not CD46 expression is required for MV spread between neurons. Collectively, these results suggest that the neuronal environment prevents the normal mechanisms of MV spread between neurons at the level of viral assembly but allows an alternate, CD46-independent mechanism of viral transmission, possibly through the synapse.

APA, Harvard, Vancouver, ISO, and other styles

11

Lenar, Nikola, Robert Piech, Jan Wyrwa, and Beata Paczosa-Bator. "Potassium-Selective Solid-Contact Electrode with High-Capacitance Hydrous Iridium Dioxide in the Transduction Layer." Membranes 11, no. 4 (April 4, 2021): 259. http://dx.doi.org/10.3390/membranes11040259.

Full text

Abstract:

This work presents new material for solid-contact layers—hydrous iridium dioxide IrO2·2H2O, characterized by high electrical capacitance value, evaluated using chronopotentiometry (1.22 mF) and electrochemical impedance spectroscopy (1.57 mF). The remarkable electrical parameters of layers resulted in great analytical parameters of IrO2·2H2O-contacted potassium-selective electrodes. Various parameters of ion-selective electrodes were examined in the scope of this work using a potentiometry method including: linear range, repeatability, stability of potentiometric response and sensitivity to varying measurement conditions. The analytical parameters obtained for solid-contact electrodes were compared with the ones obtained for coated disc electrodes to evaluate the influence of the iridium dioxide layer. The linear range of the IrO2·2H2O-contacted K+-selective electrodes covered concentrations of K+ ions from 10−6 to 10−1 M and the potential stability was estimated at 0.097 mV/h. The IrO2·2H2O-contacted electrodes turned out to be insensitive to varying light exposure and changes in the pH values of measured solutions (in the pH range of 2 to 10.5). A water layer test proved that, contrary to the coated disc electrode, the substantial water film is not formed between the ion-selective membrane and iridium dioxide layer.

APA, Harvard, Vancouver, ISO, and other styles

12

Sotnikov, Oleg S., Svetlana S. Sergeeva, and Tat'yana I. Vasyagina. "NEURONAL-GLIAL MEMBRANE CONTACTS DURING PESSIMAL ELECTRICAL STIMULATION." Morphological newsletter 28, no. 3 (August 26, 2020): 35–50. http://dx.doi.org/10.20340/mv-mn.2020.28(3):35-50.

Full text

Abstract:

After the creation of a method for obtaining inter-neuronal gap junctions in a nervous system devoid of glia, it is expedient to reproduce gap neuronal-glial contacts on a model that also contains hybrid neuronal-glial gap junctions, which, as you know, are functionally fundamentally different from inter-neuronal contacts. The experiments were carried out on the truncus sympathicus ganglia of laboratory rats using pessimal electrical stimulation and transmission electron microscopy. Electrical activation of ganglia with a frequency of up to 100 Hz revealed local and widespread variants of various neuronal-glial connections (contacts, bridges), fringed with peri-membrane filamentous proteins. They had a blurred veil that masked two-layer neuro-membranes. Some of the contacts resembled slit or dense 5-layer structures without a visible inter-neuronal slit, but with an extreme decrease in the thickness of the contact slit. The main result of the experiments was the formation, in addition to slotted, multiple septate (ladder) contacts. Relatively independent aggregates of the electron-dense substance of the septa were located inside the intercellular gaps, crossing both adjacent membranes, and, possibly, permeate of them. Near-membrane, poorly outlined pyramid-like protein cones associated with both cell membranes were also formed. Such membranes appeared to be dotted-dashed, that is, not continuous. A significant number of septic contact membranes had endocytic invaginations (invaginations) facing neuroplasm with pyramid-like marginal projections. All reactive altered structures that have arisen de novo are considered by the authors as developed under the influence of frequency electrical stimulation of denaturation and aggregation of intrinsic and perimembrane proteins.

APA, Harvard, Vancouver, ISO, and other styles

13

Narangari, Parvathala Reddy, Siva Krishna Karuturi, Yiliang Wu, Jennifer Wong-Leung, Kaushal Vora, Mykhaylo Lysevych, Yimao Wan, Hark Hoe Tan, Chennupati Jagadish, and Sudha Mokkapati. "Ultrathin Ta2O5 electron-selective contacts for high efficiency InP solar cells." Nanoscale 11, no. 15 (2019): 7497–505. http://dx.doi.org/10.1039/c8nr09932d.

Full text

Abstract:

This work demonstrates stoichiometric Ta₂O₅ ultrathin layer as a novel and efficient electron-selective contact for planar InP heterojunction solar cells achieving an efficiency of 19.1% and a highest ever reported open circuit voltage of 822 mV.

APA, Harvard, Vancouver, ISO, and other styles

14

Tous, Loic, Richard Russell, Emanuele Cornagliotti, Angel Uruena, Patrick Choulat, Michael Haslinger, Joachim John, Filip Duerinckx, and Jozef Szlufcik. "22.4% bifacial n-PERT cells with Ni/Ag co-plated contacts and Voc ~691 mV." Energy Procedia 124 (September 2017): 922–29. http://dx.doi.org/10.1016/j.egypro.2017.09.292.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Chen, Yang, Yongqing He, and Xiaoqin Zhu. "Non-Contact Monitoring on the Flow Status inside a Pulsating Heat Pipe." Sensors 20, no. 20 (October 21, 2020): 5955. http://dx.doi.org/10.3390/s20205955.

Full text

Abstract:

The paper presents a concept of thermal-to-electrical energy conversion by using the oscillatory motion of magnetic fluid slugs which has potential to be applied in the field of sensors. A pulsating heat pipe (PHP) is introduced to produce vapor-magnetic fluid plug–slug flow in a snake-shaped capillary tube. As the magnetic fluid is magnetized by the permanent magnet, the slugs of magnetic fluid passing through the copper coils make the magnetic flux vary and produce the electromotive force. The peak values of induced voltage observed in our tests are from 0.1 mV to 4.4 mV. The effects of the slug velocity, heat input and magnetic particle volume concentration on the electromotive force are discussed. Furthermore, a theoretical model considering the fluid velocity of the working fluid, the inner radius of the PHP and the contact angle between the working fluid and the pipe wall is established. At the same time, the theoretical and experimental results are compared, and the influences of tube inner radius, working fluid velocity and contact angle on the induced electromotive force are analyzed.

APA, Harvard, Vancouver, ISO, and other styles

16

Santiago, Luis, and Margarida Gonçalo. "Occupational allergic contact dermatitis caused by Acticide MV, a brand name for the mixture methylchloroisothiazolinone/methylisothiazolinone." Contact Dermatitis 79, no. 1 (March 23, 2018): 46–47. http://dx.doi.org/10.1111/cod.12984.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Djunaidi, Muhammad Cholid, Mei Dian Risda Afriani, Gunawan Gunawan, and Miratul Khasanah. "Synthesis of Graphite Paste/Molecularly Imprinted Polymer (MIP) Electrodes Based on Polyeugenol as a Glucose Sensor with Potentiometric Method." Indonesian Journal of Chemistry 21, no. 4 (May 21, 2021): 816. http://dx.doi.org/10.22146/ijc.58964.

Full text

Abstract:

Diabetes mellitus is a chronic disease in which the body is unable to metabolize carbohydrates, fats, and proteins. In this study, eugenol was polymerized and then contacted with glucose and crosslinked using polyethylene glycol diglycidyl ether (PEGDE). The resulted PE-Glucose-PEGDE was eluted using ethanol to form MIP-Glucose. It was then characterized by FTIR, SEM, electrodes using the Eutech 510 potentiostat and UV-Vis spectrophotometer. The result of polyeugenol synthesis is a reddish-brown powder with a yield of 99.90% and a molecular weight of 6318.033 g/mol. UV-Vis spectrophotometer analysis showed that the contacted glucose was 2152.505 ppm. SEM results showed differences in the surface morphology of the material, indicating the formation of cavities in MIP and ESM, while no cavities are found in NIP and ESN. The electrode optimization resulted in the best composition ratio of MIP 1 mol: paraffin: graphite, respectively of 20:35:45. The resulting electrode has a Nernst factor of 20.24 mV/decade with a measurement range of 10–5–10–1 M, a limit of detection value of 8.363 × 10–5 M, and the value of the selectivity coefficient (Kij) of the electrodes in a (10–5–10–1) M fructose solution was 0.3733; 0.23048; 0.17864; 0.12359; 0.1073.

APA, Harvard, Vancouver, ISO, and other styles

18

Lee, Yu-Tsu, Fang-Ru Lin, and Zingway Pei. "Solution-Processed Titanium Oxide for Rear Contact Improvement in Heterojunction Solar Cells." Energies 13, no. 18 (September 7, 2020): 4650. http://dx.doi.org/10.3390/en13184650.

Full text

Abstract:

In this work, we demonstrated a heterojunction Si solar cell utilizing chemically grown titanium oxide (TiOx) as an electron-selective contact layer at its rear surface. With TiOx, the rear surface was passivated to reduce carrier recombination. The reverse saturation current, which is an indicator of carrier recombination, exhibited a 4.4-fold reduction after placing a TiOx layer on the rear surface. With reduced recombination, the open-circuit voltage increased from 433 mV to 600 mV and consequently, the power conversion efficiency (PCE) increased from 9.57 to 14.70%. By X-ray photoemission spectroscopy, the surface passivation was attributed to a silicon oxide interfacial layer formed during the chemical growth process. This passivation results in a 625 cm/s surface recombination velocity for the TiOx-passivated Si surface, which is 2.4 times lower than the sample without TiOx, ensuring the carriers pass through the rear contact without extensive recombination. According to these results, the band alignment for the heterojunction solar cell with and without a TiOx rear contact layer was plotted, the reduced interfacial recombination and the electron and hole blocking structure are the main reasons for the observed efficiency enhancement.

APA, Harvard, Vancouver, ISO, and other styles

19

NAIDYUK, Y., M. REIFFERS, A. G. M. JANSEN, I. K. YANSON, P. WYDER, D. GIGNOUX, and D. SCHMITT. "MAGNETIC FIELD DEPENDENCE OF THE POINT-CONTACT SPECTRA OF CeNi5." International Journal of Modern Physics B 07, no. 01n03 (January 1993): 222–25. http://dx.doi.org/10.1142/s0217979293000494.

Full text

Abstract:

The intermetallic compound CeNi 5, where Ce is not magnetic and in the maximum valence state, is an enhanced Pauli paramagnet in which spin fluctuations are present. For point contacts between a CeNi 5 single crystal and Cu, the second derivatives of the I-V characteristics reveal a maximum at low voltages (around 3 mV) which disappears in applied magnetic fields above 10 T. This behaviour in the point-contact spectra is ascribed to the quenching of spin fluctuations by the magnetic field.

APA, Harvard, Vancouver, ISO, and other styles

20

Wei, Rongshan, and Yuxuan Du. "Analysis of Orthogonal Coupling Structure Based on Double Three-Contact Vertical Hall Device." Micromachines 10, no. 9 (September 14, 2019): 610. http://dx.doi.org/10.3390/mi10090610.

Full text

Abstract:

A vertical Hall device is an important component of 3D Hall sensors, used for detecting magnetic fields parallel to the sensor surface. The Hall devices described in existing research still have problems, such as large offset voltage and low sensitivity. Aiming to solve these problems, this study proposes a double three-contact vertical Hall device with low offset voltage, and a conformal mapping analysis method to improve the sensitivity of the device. Secondly, an orthogonal coupling structure composed of two sets of double three-contact vertical Hall devices is proposed, which further reduces the offset voltage of the device. Finally, the TCAD simulation software was used to analyze the performance of the devices, and an existing vertical Hall device was compared to ours. The results show that the orthogonal coupling structure in this study exhibits better performance, reaching an average voltage sensitivity of 17.5222 mV/VT and an average offset voltage of about 0.075 mV. In addition, the structure has the same magnitude of offset voltage in the four phases of the rotating current method. This characteristic enables the back-end circuit to more accurately filter out the offset voltage and acquire the Hall signal.

APA, Harvard, Vancouver, ISO, and other styles

21

Went, Cora M., Joeson Wong, Phillip R. Jahelka, Michael Kelzenberg, Souvik Biswas, Matthew S. Hunt, Abigail Carbone, and Harry A. Atwater. "A new metal transfer process for van der Waals contacts to vertical Schottky-junction transition metal dichalcogenide photovoltaics." Science Advances 5, no. 12 (December 2019): eaax6061. http://dx.doi.org/10.1126/sciadv.aax6061.

Full text

Abstract:

Two-dimensional transition metal dichalcogenides are promising candidates for ultrathin optoelectronic devices due to their high absorption coefficients and intrinsically passivated surfaces. To maintain these near-perfect surfaces, recent research has focused on fabricating contacts that limit Fermi-level pinning at the metal-semiconductor interface. Here, we develop a new, simple procedure for transferring metal contacts that does not require aligned lithography. Using this technique, we fabricate vertical Schottky-junction WS2 solar cells, with Ag and Au as asymmetric work function contacts. Under laser illumination, we observe rectifying behavior and open-circuit voltage above 500 mV in devices with transferred contacts, in contrast to resistive behavior and open-circuit voltage below 15 mV in devices with evaporated contacts. One-sun measurements and device simulation results indicate that this metal transfer process could enable high specific power vertical Schottky-junction transition metal dichalcogenide photovoltaics, and we anticipate that this technique will lead to advances for two-dimensional devices more broadly.

APA, Harvard, Vancouver, ISO, and other styles

22

Noubouossie, Denis F., Michael W. Henderson, Micah Mooberry, Anton Ilich, Patrick Ellsworth, Mark Piegore, Sarah C. Skinner, et al. "Red blood cell microvesicles activate the contact system, leading to factor IX activation via 2 independent pathways." Blood 135, no. 10 (March 5, 2020): 755–65. http://dx.doi.org/10.1182/blood.2019001643.

Full text

Abstract:

Abstract Storage lesion–induced, red cell–derived microvesicles (RBC-MVs) propagate coagulation by supporting the assembly of the prothrombinase complex. It has also been reported that RBC-MVs initiate coagulation via the intrinsic pathway. To elucidate the mechanism(s) of RBC-MV–induced coagulation activation, the ability of storage lesion–induced RBC-MVs to activate each zymogen of the intrinsic pathway was assessed in a buffer system. Simultaneously, the thrombin generation (TG) assay was used to assess their ability to initiate coagulation in plasma. RBC-MVs directly activated factor XII (FXII) or prekallikrein, but not FXI or FIX. RBC-MVs initiated TG in normal pooled plasma and in FXII- or FXI-deficient plasma, but not in FIX-deficient plasma, suggesting an alternate pathway that bypasses both FXII and FXI. Interestingly, RBC-MVs generated FIXa in a prekallikrein-dependent manner. Similarly, purified kallikrein activated FIX in buffer and initiated TG in normal pooled plasma, as well as FXII- or FXI-deficient plasma, but not FIX-deficient plasma. Dual inhibition of FXIIa by corn trypsin inhibitor and kallikrein by soybean trypsin inhibitor was necessary for abolishing RBC-MV–induced TG in normal pooled plasma, whereas kallikrein inhibition alone was sufficient to abolish TG in FXII- or FXI-deficient plasma. Heating RBC-MVs at 60°C for 15 minutes or pretreatment with trypsin abolished TG, suggesting the presence of MV-associated proteins that are essential for contact activation. In summary, RBC-MVs activate both FXII and prekallikrein, leading to FIX activation by 2 independent pathways: the classic FXIIa-FXI-FIX pathway and direct kallikrein activation of FIX. These data suggest novel mechanisms by which RBC transfusion mediates inflammatory and/or thrombotic outcomes.

APA, Harvard, Vancouver, ISO, and other styles

23

Ferragamo, Michael J., and Donata Oertel. "Octopus Cells of the Mammalian Ventral Cochlear Nucleus Sense the Rate of Depolarization." Journal of Neurophysiology 87, no. 5 (May 1, 2002): 2262–70. http://dx.doi.org/10.1152/jn.00587.2001.

Full text

Abstract:

Whole cell patch recordings in slices show that the probability of firing of action potentials in octopus cells of the ventral cochlear nucleus depends on the dynamic properties of depolarization. Octopus cells fired only when the rate of rise of a depolarization exceeded a threshold value that varied between 5 and 15 mV/ms among cells. The threshold rate of rise was independent of whether depolarizations were evoked synaptically or by the intracellular injection of current. Previous work showed that octopus cells are contacted by many auditory nerve fibers, each providing less than 1-mV depolarization. Summation of synaptic input from multiple fibers is required for an octopus cell to reach threshold. In firing only when synaptic depolarization exceeds a threshold rate, octopus cells fire selectively when synaptic input is sufficiently large and synchronized for the small, brief unitary excitatory postsynaptic potentials (EPSPs) to sum to produce a rapidly rising depolarization. The sensitivity to rate of depolarization is governed by a low-threshold, α-dendrotoxin-sensitive potassium conductance ( g KL). This conductance also shapes the peaks of action potentials, contributing to the precision in their timing. Firing in neighboring T stellate cells depends much less strongly on the rate of rise. They lack strong α-dendrotoxin-sensitive conductances. Octopus cells appear to be specialized to detect synchronization in the activation of groups of auditory nerve fibers, a common pattern in responses to natural sounds, and convey its occurrence with temporal precision.

APA, Harvard, Vancouver, ISO, and other styles

24

HÄCKEL, S., J. DONEIT, A. PINKOWSKI, and W. J. LORENZ. "DIODE CHARACTERISTICS OF YBa2Cu3O7/n- TYPE SILICON CONTACTS." Modern Physics Letters B 02, no. 11n12 (December 1988): 1303–8. http://dx.doi.org/10.1142/s0217984988001284.

Full text

Abstract:

The temperature dependences of diode characteristics were measured on high-T c -superconducting YBa 2 Cu 3 O 7 (polycrystalline)/n-type silicon (monocrystalline) contacts using a common two-pole-technique at low frequencies. The non-superconducting p-type semiconductor YBa 2 Cu 3 O 6.5 (polycrystalline) served as a reference substance. The temperature coefficients of the diffusion voltage, the diffusion current and the saturation current were found to be finite at T>T c , but almost zero at T≤T c . At T=78 K , the diffusion voltage of the diode YBa 2 Cu 3 O 7/n-type silicon was about 200 mV lower as compared to that of the reference diode YBa 2 Cu 3 O 6.5/n-type silicon. The observed phenomena are explained in terms of different charge carrier behavior in the superconducting ceramics above and below T c .

APA, Harvard, Vancouver, ISO, and other styles

25

Marchiori, Bastien, Simon Regal, Yanid Arango, Roger Delattre, Sylvain Blayac, and Marc Ramuz. "PVDF-TrFE-Based Stretchable Contact and Non-Contact Temperature Sensor for E-Skin Application." Sensors 20, no. 3 (January 22, 2020): 623. http://dx.doi.org/10.3390/s20030623.

Full text

Abstract:

Development of stretchable electronics has been driven by key applications such as electronics skin for robotic or prosthetic. Mimicking skin functionalities imposes at a minimal level: stretchability, pressure, and temperature sensing capabilities. While the research on pressure sensors for artificial skin is extensive, stretchable temperature sensors remain less explored. In this work, a stretchable temperature and infrared sensor has been developed on a polydimethylsiloxane substrate. The sensor is based on poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) as a pyroelectric material. This material is sandwiched between two electrodes. The first one consists of aluminium serpentines, covered by gold in order to get electrical contact and maximum stretchability. The second one is based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) that has shown good electrical compatibility with PVDF-TrFE and provides the stretchability of the top electrode. Without poling the PVDF-TrFE, sensor has shown a sensitivity of around 7 pF.°C−1 up to 35% strain without any change in its behaviour. Then, taking advantage on infrared absorption of PEDOT:PSS, a poled device has shown a pyroelectric peak of 13 mV to an infrared illumination of 5 mW at 830 nm. This stretchable device valuably allows an electronic skin (e-skin) use for contact and more importantly non-contact thermal sensing.

APA, Harvard, Vancouver, ISO, and other styles

26

Hellinger, Carsten, Oleg Rusch, Mathias Rommel, Anton J. Bauer, and Tobias Erlbacher. "Low-Resistance Ohmic Contact Formation by Laser Annealing of N-Implanted 4H-SiC." Materials Science Forum 1004 (July 2020): 718–24. http://dx.doi.org/10.4028/www.scientific.net/msf.1004.718.

Full text

Abstract:

In this work, pulsed-laser-based tempering was applied for post-implant annealing of n-type N-doped 4H-SiC in order to electrically activate the dopants and to rebuild the crystal structure. The annealing was performed by a frequency-tripled Nd:YVO4 laser with a pulse duration of 60 ns. To evaluate the effects of post-implant annealing, JBS diodes were electrically characterized. The results were compared with implanted, not post-annealed JBS diodes. The electrical measurements showed a significant on-state voltage drop of 40 mV at 6 A for post-implant laser annealed diodes compared to not post-implant annealed diodes.

APA, Harvard, Vancouver, ISO, and other styles

27

Pascu, Razvan, Gheorghe Pristavu, Gheorghe Brezeanu, Florin Draghici, Marian Badila, Ion Rusu, and Florea Craciunoiu. "Electrical Characterization of Ni-Silicide Schottky Contacts on SiC for High Performance Temperature Sensor." Materials Science Forum 821-823 (June 2015): 436–39. http://dx.doi.org/10.4028/www.scientific.net/msf.821-823.436.

Full text

Abstract:

The electrical behavior and stability of a temperature sensor based on 4H-SiC Schottky diodes using Ni2Si as Schottky contact, are investigated. The ideality factor and the barrier height were found to be strongly dependent on the post-annealing temperature of the Ni contact (which lead to the formation of Ni2Si). A nearly ideal Schottky device, with the barrier height approaching the high value of1.7eV, and a slight temperature dependence, was obtained after an annealing atTA=800°C.This high barrier height proves that Ni2Si is suitable as Schottky contact for temperature sensors, able to reliably operate up to450°C. Sensor sensitivity levels between1.00mV/°Cand2.70 mV/°Chave been achieved.

APA, Harvard, Vancouver, ISO, and other styles

28

Kulapina, E. G., A. E. Dubasova, O. I. Kulapina, and V. D. Ankina. "Arrays of solid contact potentiometric sensors for separate determination of some cephalosporin antibiotics." Industrial laboratory. Diagnostics of materials 87, no. 5 (May 23, 2021): 5–13. http://dx.doi.org/10.26896/1028-6861-2021-87-5-5-13.

Full text

Abstract:

Arrays of potentiometric sensors including developed solid-contact unmodified and modified sensors based on tetradecylammonium associates with complex compounds of silver (1) and some β-lactam antibiotics (cefazoline, cefuroxime, cefotaxime (n = 3 – 6)) are proposed; polyaniline and copper oxide being modifiers. The main electroanalytic properties of the sensors are determined (the range of the determined concentrations in antibiotic solutions 1 × 10–4 – 0.1 M, 46.3 < S < 48, Cmin = n × 10–5 М, response time 4 – 10 sec, potential drift 4 – 6 mV/day, service life — 2 months). It is shown that modification of the membrane surfaces brings the steepness of the electrode functions to Nernst-values for single-charged ions of the antibiotics under study; reduces the response time and the detection limits, the linearity intervals of the electrode functions being the same. The potentiometric selectivity coefficients of unmodified and modified sensors based on different electrode active components (EAC) to the studied cephalosporins in the presence of interfering antibiotics are close to unity; cross sensitivity parameters for the considered sensors (the average slope of the electrode function of the sensor Sav, the unselectivity factor F, and the reproducibility factor K) are 46.3 < S (mV/pC) < 48; 0.85 < F < 0.90; 144 < K < 170, respectively. Application of sensors in the multisensory analysis of model mixtures of cephalosporin antibiotics is shown. Method of artificial neural networks (ANN) is used for processing of analytical signals. The correctness of the determination is carried out using «spike tests» on the reference model mixtures (the relative error of the determination does not exceed 12 %).

APA, Harvard, Vancouver, ISO, and other styles

29

Park, HyunJung, Hyomin Park, Se Jin Park, Soohyun Bae, Hyunho Kim, Jee Woong Yang, Ji Yeon Hyun, et al. "Passivation quality control in poly-Si/SiO /c-Si passivated contact solar cells with 734 mV implied open circuit voltage." Solar Energy Materials and Solar Cells 189 (January 2019): 21–26. http://dx.doi.org/10.1016/j.solmat.2018.09.013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Simchi, Hamed, Brian E. McCandless, T. Meng, Jonathan H. Boyle, and William N. Shafarman. "MoO3 back contact for CuInSe2-based thin film solar cells." MRS Proceedings 1538 (2013): 173–78. http://dx.doi.org/10.1557/opl.2013.1018.

Full text

Abstract:

ABSTRACTMoO3 films with a high work function (5.5 eV), high transparency, and a wide bandgap (3.0 - 3.4 eV) are a potential candidate for the primary back contact of Cu(InGa)Se2 thin film solar cells. This may be advantageous to form ohmic contact in superstrate devices where the back contact will be deposited after the Cu(InGa)Se2 layer and MoSe2 layer doesn’t form during Cu(InGa)Se2 deposition. In addition, the MoO3 may be incorporated in a transparent back contact in tandem or bifacial cells. In this study, MoO3 films for use as a back contact for Cu(In,Ga)Se2 thin film solar cells were prepared by reactive rf sputtering with O2/(O2+Ar) = 35%. The effect of post processing on the structural properties of the deposited films were investigated using x-ray diffraction and scanning electron microscopy. Annealing resulted in crystallization of the films to the α-MoO3 phases at 400°C. Increasing the oxygen partial pressure had no significant effect on optical transmittance of the films, and bandgaps in the range of 2.6-2.9 eV and 3.1-3.4 eV were obtained for the as deposited and annealed films, respectively. Cu(In,Ga)Se2 thin film solar cells prepared using an as-deposited Mo-MoO3 back contact yielded an efficiency of >14% with VOC = 647 (mV), JSC = 28.4 (mA), and FF. = 78.1%. Cells with ITO-MoO3 back contact showed an efficiency of ∼12% with VOC = 642 (mV), JSC = 26.8 (mA), and FF. = 69.2%. The efficiency of cells with an annealed MoO3 back contact was limited to 4%, showing a blocking diode behavior in the forward bias J-V curve. This may be caused by the presence of a barrier between the valence bands of the Cu(In,Ga)Se2 and MoO3, due to the higher bandgap of the annealed MoO3 films. SEM cross section studies showed uniform coverage of the as-deposited MoO3 layer and formation of voids for the annealed MoO3 film. Structural orientation of the Cu(In,Ga)Se2 absorber layer was also altered by the MoO3 film and less-oriented films were observed for either cases.

APA, Harvard, Vancouver, ISO, and other styles

31

Pinheiro, Kellen Hyde Elias, Franciana Aguiar Azêdo, Kelsy Catherina Nema Areco, and Sandra Maria Rodrigues Laranja. "Risk factors and mortality in patients with sepsis, septic and non septic acute kidney injury in ICU." Brazilian Journal of Nephrology 41, no. 4 (December 2019): 462–71. http://dx.doi.org/10.1590/2175-8239-jbn-2018-0240.

Full text

Abstract:

Abstract Acute kidney injury (AKI) has an incidence rate of 5-6% among intensive care unit (ICU) patients and sepsis is the most frequent etiology. Aims: To assess patients in the ICU that developed AKI, AKI on chronic kidney disease (CKD), and/or sepsis, and identify the risk factors and outcomes of these diseases. Methods: A prospective observational cohort quantitative study that included patients who stayed in the ICU > 48 hours and had not been on dialysis previously was carried out. Results: 302 patients were included and divided into: no sepsis and no AKI (nsnAKI), sepsis alone (S), septic AKI (sAKI), non-septic AKI (nsAKI), septic AKI on CKD (sAKI/CKD), and non-septic AKI on CKD (nsAKI/CKD). It was observed that 94% of the patients developed some degree of AKI. Kidney Disease Improving Global Outcomes (KDIGO) stage 3 was predominant in the septic groups (p = 0.018). Nephrologist follow-up in the non-septic patients was only 23% vs. 54% in the septic groups (p < 0.001). Dialysis was performed in 8% of the non-septic and 37% of the septic groups (p < 0.001). Mechanical ventilation (MV) requirement was higher in the septic groups (p < 0.001). Mortality was 38 and 39% in the sAKI and sAKI/CKD groups vs 16% and 0% in the nsAKI and nsAKI/CKD groups, respectively (p < 0.001). Conclusions: Patients with sAKI and sAKI/CKD had worse prognosis than those with nsAKI and nsAKI/CKD. The nephrologist was not contacted in a large number of AKI cases, except for KDIGO stage 3, which directly influenced mortality rates. The urine output was considerably impaired, ICU stay was longer, use of MV and mortality were higher when kidney injury was combined with sepsis.

APA, Harvard, Vancouver, ISO, and other styles

32

Abid, Idriss, Jash Mehta, Yvon Cordier, Joff Derluyn, Stefan Degroote, Hideto Miyake, and Farid Medjdoub. "AlGaN Channel High Electron Mobility Transistors with Regrown Ohmic Contacts." Electronics 10, no. 6 (March 10, 2021): 635. http://dx.doi.org/10.3390/electronics10060635.

Full text

Abstract:

High power electronics using wide bandgap materials are maturing rapidly, and significant market growth is expected in a near future. Ultra wide bandgap materials, which have an even larger bandgap than GaN (3.4 eV), represent an attractive choice of materials to further push the performance limits of power devices. In this work, we report on the fabrication of AlN/AlGaN/AlN high-electron mobility transistors (HEMTs) using 50% Al-content on the AlGaN channel, which has a much wider bandgap than the commonly used GaN channel. The structure was grown by metalorganic chemical vapor deposition (MOCVD) on AlN/sapphire templates. A buffer breakdown field as high as 5.5 MV/cm was reported for short contact distances. Furthermore, transistors have been successfully fabricated on this heterostructure, with low leakage current and low on-resistance. A remarkable three-terminal breakdown voltage above 4 kV with an off-state leakage current below 1 μA/mm was achieved. A regrown ohmic contact was used to reduce the source/drain ohmic contact resistance, yielding a drain current density of about 0.1 A/mm.

APA, Harvard, Vancouver, ISO, and other styles

33

Desthieux, Anatole, Jorge Posada, Pierre-Philippe Grand, Cédric Broussillou, Barbara Bazer-Bachi, Gilles Goaer, Davina Messou, Muriel Bouttemy, Etienne Drahi, and Pere Roca i Cabarrocas. "Impact of PECVD μc-Si:H deposition on tunnel oxide for passivating contacts." EPJ Photovoltaics 11 (2020): 3. http://dx.doi.org/10.1051/epjpv/2020001.

Full text

Abstract:

Passivating contacts are becoming a mainstream option in current photovoltaic industry due to their ability to provide an outstanding surface passivation along with a good conductivity for carrier collection. However, their integration usually requires long annealing steps which are not desirable in industry. In this work we study PECVD as a way to carry out all deposition steps: silicon oxide (SiOx), doped polycrystalline silicon (poly-Si) and silicon nitride (SiNx:H), followed by a single firing step. Blistering of the poly-Si layer has been avoided by depositing (p+) microcrystalline silicon (μc-Si:H). We report on the impact of this deposition step on the SiOx layer deposited by PECVD, and on the passivation properties by comparing PECVD and wet-chemical oxide in this hole-selective passivating contact stack. We have reached iVoc > 690 mV on p-type FZ wafers for wet-chemical SiOx\(p+) μc-Si\SiNx:H with no annealing step.

APA, Harvard, Vancouver, ISO, and other styles

34

Li, Shenghao, Manuel Pomaska, Jan Hoß, Jan Lossen, Frank Pennartz, Maurice Nuys, Ruijiang Hong, et al. "Poly-Si/SiOx/c-Si passivating contact with 738 mV implied open circuit voltage fabricated by hot-wire chemical vapor deposition." Applied Physics Letters 114, no. 15 (April 15, 2019): 153901. http://dx.doi.org/10.1063/1.5089650.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Diwakar, Shyam, Jacopo Magistretti, Mitchell Goldfarb, Giovanni Naldi, and Egidio D'Angelo. "Axonal Na+ Channels Ensure Fast Spike Activation and Back-Propagation in Cerebellar Granule Cells." Journal of Neurophysiology 101, no. 2 (February 2009): 519–32. http://dx.doi.org/10.1152/jn.90382.2008.

Full text

Abstract:

In most neurons, Na+ channels in the axon are complemented by others localized in the soma and dendrites to ensure spike back-propagation. However, cerebellar granule cells are neurons with simplified architecture in which the dendrites are short and unbranched and a single thin ascending axon travels toward the molecular layer before bifurcating into parallel fibers. Here we show that in cerebellar granule cells, Na+ channels are enriched in the axon, especially in the hillock, but almost absent from soma and dendrites. The impact of this channel distribution on neuronal electroresponsiveness was investigated by multi-compartmental modeling. Numerical simulations indicated that granule cells have a compact electrotonic structure allowing excitatory postsynaptic potentials to diffuse with little attenuation from dendrites to axon. The spike arose almost simultaneously along the whole axonal ascending branch and invaded the hillock the activation of which promoted spike back-propagation with marginal delay (<200 μs) and attenuation (<20 mV) into the somato-dendritic compartment. These properties allow granule cells to perform sub-millisecond coincidence detection of pre- and postsynaptic activity and to rapidly activate Purkinje cells contacted by the axonal ascending branch.

APA, Harvard, Vancouver, ISO, and other styles

36

Shen, Mei, Amir Afshar, Manisha Gupta, Gem Shoute, Ken Cadien, Ying Yin Tsui, and Doug Barlage. "Electrical Characteristics of TiW/ZnO Schottky contact with ALD and PLD." MRS Proceedings 1635 (2014): 127–32. http://dx.doi.org/10.1557/opl.2014.49.

Full text

Abstract:

ABSTRACTAn electrical and analytical study was carried out to investigate TiW/ZnO Schottky contacts with 30 nm ZnO thin film layers deposited by pulsed laser deposition (PLD), plasma enhanced atomic layer deposition (PEALD), and thermal atomic layer deposition (TALD). Devices with ZnO layer deposited by TALD exhibit approximately linear behavior in their I-V measurements. However, both devices with ZnO layers deposited by PEALD and PLD behaved like Schottky rectifiers with barrier heights between TiW and ZnO of 0.51 eV and 0.45 eV respectively and ideality factors of 2.0 and 2.3 respectively. The PEALD deposited ZnO Schotty diodes demonstrated an on/off rectifying ratio of about 25 at ±1 V. The leakage current values of the PLD deposited ZnO Schottky diodes are significantly larger than those of PEALD, leading to a poor on/off rectifying ratio of ∼4. Due to the small thickness, a critical breakdown strength of 1.3 MV/cm was estimated for PEALD-ZnO thin films.

APA, Harvard, Vancouver, ISO, and other styles

37

Marchand, A. R., W. J. P. Barnes, and D. Cattaert. "Primary Afferent Depolarizations of Sensory Origin Within Contact-Sensitive Mechanoreceptive Afferents of a Crayfish Leg." Journal of Neurophysiology 77, no. 6 (June 1, 1997): 3340–54. http://dx.doi.org/10.1152/jn.1997.77.6.3340.

Full text

Abstract:

Marchand, A. R., W.J.P. Barnes, and D. Cattaert. Primary afferent depolarizations of sensory origin within contact-sensitive mechanoreceptive afferents of a crayfish leg: properties, quantal analysis, and role in presynaptic integration. J. Neurophysiol. 77: 3340–3354, 1997. Recordings from the central branches of single identified dactyl sensory afferent (DSA) neurons in a crayfish in vitro preparation were performed to study modifications of the sensory message occurring before the first central synapse. These afferents comprised hairs and force-sensitive mechanoreceptors with phasic and phasotonic response characteristics in the terminal segment (dactyl) of the crayfish leg. More than one afferent spike size was often observed in intracellular recordings from these afferents, thus indicating the presence of electrical coupling between the central processes of DSA fibers. Additionally, in identified DSA fibers with large spike sizes, primary afferent depolarizations (PADs) of up to 15 mV were observed, which sometimes triggered antidromic spikes in the afferent. Nevertheless, PADs were clearly inhibitory, because they shunted the afferent spikes. They exhibited the following properties. First, each PAD was preceded by an afferent spike from a neighboring hair, indicating that the PADs had a sensory rather than central origin. Second, PADs could follow high frequencies of afferent discharges without failure, a property suggestive of monosynaptic connections, but because PAD latencies varied by ±0.5 ms it is more likely that they were mediated by a disynaptic pathway. Third, although PADs were evoked in an extremely reliable manner, their amplitude varied in a quantal manner. Most unitary PADs were the result of the release of <12 quanta, the mean quantal content lying between 4 and 5; quantal size was large, ∼1 mV. Fourth, PADs showed facilitation in some fibers, whereas in others they became much smaller when occurring at brief intervals. We suggest that PADs may be an efficient and parsimonious way to limit sensory inflow in space and time, allowing the crayfish to identify precisely both weak and strong mechanical stimuli.

APA, Harvard, Vancouver, ISO, and other styles

38

Sontheimer, H., S. G. Waxman, and B. R. Ransom. "Relationship between Na+ current expression and cell-cell coupling in astrocytes cultured from rat hippocampus." Journal of Neurophysiology 65, no. 4 (April 1, 1991): 989–1002. http://dx.doi.org/10.1152/jn.1991.65.4.989.

Full text

Abstract:

1. Cell-cell coupling between hippocampal astrocytes in culture was studied by following the intracellular spread of the low molecular weight fluorescent dye Lucifer yellow (LY). Dye coupling appeared as early as 24 h after plating, at which time approximately 20% of all astrocytes that physically contacted neighboring cells showed dye coupling. 2. The percentage of coupled cells increased with time in culture and peaked after 10 days in vitro (DIV) when approximately 50% of astrocytes showed coupling. Further time in culture, up to 20 DIV, did not increase the percentage of coupled cells. Thus, coupled and noncoupled astrocytes coexist in hippocampal cultures in approximately equal numbers. 3. Na+ currents were expressed in a subpopulation of hippocampal astrocytes and changed characteristics during in vitro development. A "neuronal type" of Na+ current, so called because of an h alpha curve that had a midpoint near -60 mV, was observed within the first 5 days post-plating. A "glial type" of Na+ current, characterized by a -25 mV shift in its h alpha curve, was only expressed after 6 days in culture. 4. Na+ current expression was restricted to hippocampal astrocytes that did not exhibit dye coupling; astrocytes that exhibited dye coupling (n = 39) did not show measurable Na+ currents. 5. The failure to see Na+ currents in coupled astrocytes cannot be explained by insufficient space-clamp since astrocytes acutely uncoupled with octanol (10 microM) did not reveal Na+ current expression. Control experiments showed that low concentrations of octanol (i.e., 10-100 microM) did not block Na+ currents; blockage of Na+ currents by octanol was only observed at high concentrations (e.g., 50-fold the concentration used for uncoupling). These observations support the idea that Na(+)-channel expression was restricted to noncoupled astrocytes. 6. The time courses for the development of cell coupling and Na+ current expression appeared to be inversely correlated and suggested a gradual increase in cell coupling in concert with a loss in Na+ current expression with time in culture.

APA, Harvard, Vancouver, ISO, and other styles

39

Sharkeev, Yurii P., Ekaterina G. Komarova, Valentina V. Chebodaeva, Mariya B. Sedelnikova, Aleksandr M. Zakharenko, Kirill S. Golokhvast, Larisa S. Litvinova, et al. "Amorphous–Crystalline Calcium Phosphate Coating Promotes In Vitro Growth of Tumor-Derived Jurkat T Cells Activated by Anti-CD2/CD3/CD28 Antibodies." Materials 14, no. 13 (July 1, 2021): 3693. http://dx.doi.org/10.3390/ma14133693.

Full text

Abstract:

A modern trend in traumatology, orthopedics, and implantology is the development of materials and coatings with an amorphous–crystalline structure that exhibits excellent biocopatibility. The structure and physico–chemical and biological properties of calcium phosphate (CaP) coatings deposited on Ti plates using the micro-arc oxidation (MAO) method under different voltages (200, 250, and 300 V) were studied. Amorphous, nanocrystalline, and microcrystalline statesof CaHPO4 and β-Ca2P2O7 were observed in the coatings using TEM and XRD. The increase in MAO voltage resulted in augmentation of the surface roughness Ra from 2.5 to 6.5 µm, mass from 10 to 25 mg, thickness from 50 to 105 µm, and Ca/P ratio from 0.3 to 0.6. The electrical potential (EP) of the CaP coatings changed from −456 to −535 mV, while the zeta potential (ZP) decreased from −53 to −40 mV following an increase in the values of the MAO voltage. Numerous correlations of physical and chemical indices of CaP coatings were estimated. A decrease in the ZP magnitudes of CaP coatings deposited at 200–250 V was strongly associated with elevated hTERT expression in tumor-derived Jurkat T cells preliminarily activated with anti-CD2/CD3/CD28 antibodies and then contacted in vitro with CaP-coated samples for 14 days. In turn, in vitro survival of CD4+ subsets was enhanced, with proinflammatory cytokine secretion of activated Jurkat T cells. Thus, the applied MAO voltage allowed the regulation of the physicochemical properties of amorphous–crystalline CaP-coatings on Ti substrates to a certain extent. This method may be used as a technological mechanism to trigger the behavior of cells through contact with micro-arc CaP coatings. The possible role of negative ZP and Ca2+ as effectors of the biological effects of amorphous–crystalline CaP coatings is discussed. Micro-arc CaP coatings should be carefully tested to determine their suitability for use in patients with chronic lymphoid malignancies.

APA, Harvard, Vancouver, ISO, and other styles

40

Warren, Emily L., Shannon W. Boettcher, Michael G. Walter, Harry A. Atwater, and Nathan S. Lewis. "pH-Independent, 520 mV Open-Circuit Voltages of Si/Methyl Viologen2+/+ Contacts Through Use of Radial n+p-Si Junction Microwire Array Photoelectrodes." Journal of Physical Chemistry C 115, no. 2 (December 23, 2010): 594–98. http://dx.doi.org/10.1021/jp109147p.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Chelobanov, Boris, Julia Poletaeva, Anna Epanchintseva, Anastasiya Tupitsyna, Inna Pyshnaya, and Elena Ryabchikova. "Ultrastructural Features of Gold Nanoparticles Interaction with HepG2 and HEK293 Cells in Monolayer and Spheroids." Nanomaterials 10, no. 10 (October 16, 2020): 2040. http://dx.doi.org/10.3390/nano10102040.

Full text

Abstract:

Use of multicellular spheroids in studies of nanoparticles (NPs) has increased in the last decade, however details of NPs interaction with spheroids are poorly known. We synthesized AuNPs (12.0 ± 0.1 nm in diameter, transmission electron microscopy (TEM data) and covered them with bovine serum albumin (BSA) and polyethyleneimine (PEI). Values of hydrodynamic diameter were 17.4 ± 0.4; 35.9 ± 0.5 and ±125.9 ± 2.8 nm for AuNPs, AuBSA-NPs and AuPEI-NPs, and Z-potential (net charge) values were −33.6 ± 2.0; −35.7 ± 1.8 and 39.9 ± 1.3 mV, respectively. Spheroids of human hepatocarcinoma (HepG2) and human embryo kidney (HEK293) cells (Corning ® spheroid microplates CLS4515-5EA), and monolayers of these cell lines were incubated with all NPs for 15 min–4 h, and fixed in 4% paraformaldehyde solution. Samples were examined using transmission and scanning electron microscopy. HepG2 and HEK2893 spheroids showed tissue-specific features and contacted with culture medium by basal plasma membrane of the cells. HepG2 cells both in monolayer and spheroids did not uptake of the AuNPs, while AuBSA-NPs and AuPEI-NPs readily penetrated these cells. All studied NPs penetrated HEK293 cells in both monolayer and spheroids. Thus, two different cell cultures maintained a type of the interaction with NPs in monolayer and spheroid forms, which not depended on NPs Z-potential and size.

APA, Harvard, Vancouver, ISO, and other styles

42

EJDERHA, KADIR, SEZAI ASUBAY, NEZIR YILDIRIM, ÖMER GÜLLÜ, ABDULMECIT TURUT, and BAHATTIN ABAY. "THE CHARACTERISTIC DIODE PARAMETERS IN Ti/p-InP CONTACTS PREPARED BY DC SPUTTERING AND EVAPORATION PROCESSES OVER A WIDE MEASUREMENT TEMPERATURE." Surface Review and Letters 24, no. 04 (September 2016): 1750052. http://dx.doi.org/10.1142/s0218625x17500524.

Full text

Abstract:

The titanium/[Formula: see text]-indium phosphide (Ti/[Formula: see text]-InP) Schottky diodes (SDs) have been prepared by thermal evaporation and DC magnetron sputtering deposition. Then, their current–voltage ([Formula: see text]–[Formula: see text]) characteristics have been measured in the sample temperature range of 100–400[Formula: see text]K with steps of 20[Formula: see text]K. The characteristic parameters of both Ti/[Formula: see text]-InP SDs have been compared with each other. The barrier height (BH) values of 0.824 and 0.847 at 300[Formula: see text]K have been obtained for the sputtered and the evaporated SDs, respectively. This low BH value for the sputtered SD has been attributed to some defects introduced by the sputtered deposition technique over a limited depth in to the [Formula: see text]-type substrate. The BH of the evaporated and sputtered diodes has decreased with the standard deviations of 58 and 64[Formula: see text]mV obeying to double-Gaussian distribution (GD) in 220–400[Formula: see text]K range, respectively, and it has seen a more sharper reduction for the BHs with the standard deviations of 93 and 106 mV in 100–220[Formula: see text]K range. The Richardson constant values of 89.72 and 53.24[Formula: see text]A(Kcm)[Formula: see text] (in 220–400[Formula: see text]K range) for the evaporated and sputtered samples, respectively, were calculated from the modified ln([Formula: see text]/[Formula: see text]/2[Formula: see text] vs (kT)[Formula: see text] curves by GD of the BHs. The value 53.24[Formula: see text]A(Kcm)[Formula: see text] for the sputtered sample in high temperatures range is almost the same as the known Richardson constant value of 60[Formula: see text]A(Kcm)[Formula: see text] for [Formula: see text]-type InP.

APA, Harvard, Vancouver, ISO, and other styles

43

Lenar, Nikola, Beata Paczosa-Bator, and Robert Piech. "Optimization of Ruthenium Dioxide Solid Contact in Ion-Selective Electrodes." Membranes 10, no. 8 (August 9, 2020): 182. http://dx.doi.org/10.3390/membranes10080182.

Full text

Abstract:

Ruthenium dioxide occurs in two morphologically varied structures: anhydrous and hydrous form; both of them were studied in the scope of this work and applied as mediation layers in ion-selective electrodes. The differences between the electrochemical properties of those two materials underlie their diverse structure and hydration properties, which was demonstrated in the paper. One of the main differences is the occurrence of structural water in RuO2•xH2O, which creates a large inner surface available for ion transport and was shown to be a favorable feature in the context of designing potentiometric sensors. Both materials were examined with SEM microscope, X-ray diffractometer, and contact angle microscope, and the results revealed that the hydrous form can be characterized as a porous structure with a smaller crystallite size and more hydrophobic properties contrary to the anhydrous form. Potentiometric and electrochemical tests carried out on designed GCD/RuO2/K+-ISM and GCD/RuO2•xH2O/K+-ISM electrodes proved that the loose porous microstructure with chemically bounded water, which is characteristic for the hydrous form, ensures the high electrical capacitance of electrodes (up to 1.2 mF) with consequently more stable potential (with the potential drift of 0.0015 mV/h) and a faster response (of a few seconds).

APA, Harvard, Vancouver, ISO, and other styles

44

Lee, Changhyun, Soohyun Bae, HyunJung Park, Dongjin Choi, Hoyoung Song, Hyunju Lee, Yoshio Ohshita, Donghwan Kim, Yoonmook Kang, and Hae-Seok Lee. "Properties of Thermally Evaporated Titanium Dioxide as an Electron-Selective Contact for Silicon Solar Cells." Energies 13, no. 3 (February 5, 2020): 678. http://dx.doi.org/10.3390/en13030678.

Full text

Abstract:

Recently, titanium oxide has been widely investigated as a carrier-selective contact material for silicon solar cells. Herein, titanium oxide films were fabricated via simple deposition methods involving thermal evaporation and oxidation. This study focuses on characterizing an electron-selective passivated contact layer with this oxidized method. Subsequently, the SiO2/TiO2 stack was examined using high-resolution transmission electron microscopy. The phase and chemical composition of the titanium oxide films were analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The passivation quality of each layer was confirmed by measuring the carrier lifetime using quasi-steady-state photoconductance, providing an implied open circuit voltage of 644 mV. UV–vis spectroscopy and UV photoelectron spectroscopy analyses demonstrated the band alignment and carrier selectivity of the TiO2 layers. Band offsets of ~0.33 and ~2.6 eV relative to the conduction and valence bands, respectively, were confirmed for titanium oxide and the silicon interface.

APA, Harvard, Vancouver, ISO, and other styles

45

Kim, Junghwan, Dae Hee Kim, Jin Cheol Yang, Jae Sang Kim, Ji Ha Lee, and Sung Ho Jung. "Beryllium-Ion-Selective PEDOT Solid Contact Electrode Based on 9,10-Dinitrobenzo-9-Crown-3-Ether." Sensors 20, no. 21 (November 9, 2020): 6375. http://dx.doi.org/10.3390/s20216375.

Full text

Abstract:

A beryllium(II)-ion-selective poly(ethylenedioxythiophene) (PEDOT) solid contact electrode comprising 9,10-dinitrobenzo-9-crown-3-ether was successfully developed. The all-solid-state contact electrode, with an oxygen-containing cation-sensing membrane combined with an electropolymerized PEDOT layer, exhibited the best response characteristics. The performance of the constructed electrode was evaluated and optimized using potentiometry, conductance measurements, constant-current chronopotentiometry, and electrochemical impedance spectroscopy (EIS). Under optimized conditions, which were found for an ion-selective membrane (ISM) composition of 3% ionophore, 30% polyvinylchloride (PVC), 64% o-nitro phenyl octyl ether (o-NPOE), and 3% sodium tetraphenylborate (NaTPB), the fabricated electrode exhibited a good performance over a wide concentration range (10−2.5–10−7.0 M) and a wide pH range of 2.0–9.0, with a Nernstian slope of 29.5 mV/D for the beryllium (II) ion and a detection limit as low as 10−7.0 M. The developed electrode shows good selectivity for the beryllium(II) ion over alkali, alkaline earth, transition, and heavy metal ions.

APA, Harvard, Vancouver, ISO, and other styles

46

Hassan, Saad S. M., Ahmed Galal Eldin, Abd El-Galil E. Amr, Mohamed A. Al-Omar, and Ayman H. Kamel. "Single-Walled Carbon Nanotubes (SWCNTs) as Solid-Contact in All-Solid-State Perchlorate ISEs: Applications to Fireworks and Propellants Analysis." Sensors 19, no. 12 (June 14, 2019): 2697. http://dx.doi.org/10.3390/s19122697.

Full text

Abstract:

Herein, we present reliable, robust, stable, and cost-effective solid-contact ion-selective electrodes (ISEs) for perchlorate determination. Single-walled carbon nanotubes (SWCNTs) were used as solid-contact material and indium (III) 5, 10, 15, 20-(tetraphenyl) porphyrin chloride (InIII-porph) as an ion carrier. The sensor exhibited an improved sensitivity towards ClO4− ions with anionic slope of −56.0 ± 1.1 (R2 = 0.9998) mV/decade over a linear range 1.07 × 10−6 – 1.0 × 10−2 M and detection limit of 1.8 × 10−7 M. The short-term potential stability and the double-layer capacitance were measured by chronopotentiometric and electrochemical impedance spectroscopy (EIS) measurements, respectively. The sensor is used for ClO4− determination in fireworks and propellant powders. The results fairly agree with data obtained by ion chromatography.

APA, Harvard, Vancouver, ISO, and other styles

47

Lenar, Nikola, Robert Piech, and Beata Paczosa-Bator. "Potentiometric Sensor with High Capacity Composite Composed of Ruthenium Dioxide and Poly(3,4-ethylenedioxythiophene) Polystyrene Sulfonate." Materials 14, no. 8 (April 10, 2021): 1891. http://dx.doi.org/10.3390/ma14081891.

Full text

Abstract:

This work presents the first-time application of the ruthenium dioxide–poly(3,4-ethylenedioxythiophene) polystyrene sulfonate high-capacity composite material as a mediation layer in potassium selective electrodes, which turned out to significantly enhance the electrical and analytical parameters of the electrodes. The idea was to combine the properties of two different types of materials: a conducting polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, and a metal oxide, ruthenium dioxide, in order to obtain the material for a solid-contact layer of great electrical and physicochemical parameters. The preparation method for composite material proposed in this work is fast and easy. The mediation layer material was examined using a scanning electron microscope and chronopotentiometry in order to confirm that all requirements for mediation layers materials were fulfilled. Ruthenium dioxide–poly(3,4-ethylenedioxythiophene) polystyrene sulfonate nancomposite material turned out to exhibit remarkably high electrical capacitance (of approximately 17.5 mF), which ensured great performance of designed K+-selective sensors. Electrodes of electrical capacity equal to 7.2 mF turned out to exhibit fast and stable (with only 0.077 mV potential change per hour) potentiometric responses in the wide range of potassium ion concentrations (10−6 M to 10−1 M). The electrical capacity of ruthenium dioxide–poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-contacted electrodes characterized by electrical capacitance parameters was the highest reported so far for this type of sensor.

APA, Harvard, Vancouver, ISO, and other styles

48

Qiu, Jufeng, Xiaoning Lv, Qiyou Ren, Yuzhao Yang, and Yaohua Mai. "Dual Bilayer for Improving Contact Quality and Passivation Enables Efficient Organic/Planar-Si Hybrid Solar Cells with a Champion VOC of over 656 mV." ACS Applied Energy Materials 4, no. 5 (April 30, 2021): 5000–5006. http://dx.doi.org/10.1021/acsaem.1c00572.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Pinheiro, Vítor, Catarina Pestana, Francisco Marques, André Pinho, Isabel Antunes, and Margarida Gonçalo. "Dermatite de Contacto Alérgica em Profissionais de Saúde." Journal of the Portuguese Society of Dermatology and Venereology 75, no. 1 (April 17, 2017): 49–58. http://dx.doi.org/10.29021/spdv.75.1.718.

Full text

Abstract:

Introdução: A dermatite de contacto alérgica (DCA) constitui patologia profissional particularmente frequente em profissionais de saúde. Os alergénios responsáveis podem variar ao longe do tempo, com a exposição ocupacional e com o tipo de trabalho.Objectivos e Métodos: Com o objetivo de avaliar a realidade local, foi feita uma análise retrospetiva dos profissionais de saúde que realizaram testes epicutâneos no Serviço de Dermatologia do Centro Hospitalar e Universitário de Coimbra (CHUC), num período de 6 anos (2010-2015), por suspeita de dermatite de contacto alérgica. Os doentes foram todos testados com uma Série Básica e com séries complementares orientadas pela história clínica.Resultados: Dos 1858 doentes testados, 125 (6,7%) eram profissionais de saúde, 114 de género feminino/11 masculino, idade média de 39,26±12,5 anos, maioritariamente enfermeiras (56), assistentes técnicos (48) e médicos (21), 71 com dermatite das mãos (56.8%), 22 com dermatite atópica e/ou outros sinais de atopia (17,6%). Noventa (72%) revelaram pelo menos um patch test (PT) positivo, 47 dos quais (52,2%) com relevância profissional. Doentes com dermatite das mãos tiveram mais frequentemente PT positivo (76,1%). Os metais causaram maior número de PT positivos (total 51; Ni-41, maioritariamente com relevância passada, Co-8; Cr-2), seguidos das fragrâncias (total 30; mistura de fragrâncias (FM)-I-10; Myroxylon pereirae-8; lyral-5; FM-II-4; citronellol-3), conservantes (total 29, dos quais 20 à metilisotiazolinona (MI) e/ou clorometilisotiazolinona/MI (MCI/MI)), borrachas (24; P-fenilenodiamina (PPD)/Isopropil-PPD-9) e medicamentos tópicos (total 14; iodopovidona 5). As principais causas da DCA profissional foram os desinfetantes/sabonetes líquidos e produtos de higiene dos doentes (15), borracha das luvas/calçado (12) e medicamentos sistémicos ou tópicos (8 antissépticos e 3 antibióticos parentéricos). Os principais alergénios com relevância profissional foram a MI e/ou MCI/MI (15), lanolina (9), formaldeído e/ou libertadores (7), iodopovidona (5), carbamatos (4), FM-I (3), cefalosporinas (3) e acrilatos (3 dentistas e/ou assistentes dentários). Em 37 dos 42 casos avaliados, houve uma melhoria franca ou resolução da DCA, após evicção do alergénio causal, nomeadamente o conservante MCI/ MI contido num sabonete líquido sob a designação de “Acticide® MV”.Conclusões: A dermatite das mãos, a principal apresentação da DCA em profissionais de saúde, não mostrou relação com atopia e foi mais frequentemente associada a PT positivos. PT positivos a isotiazolinonas e libertadores de formaldeído foram mais frequentes entre profissionais de saúde do que na população geral estudada, muito provavelmente devido à exposição cumulativa, pessoal e profissional, a estes conservantes em sabonetes líquidos de uso pessoal e hospitalar. O PT foi crucial para orientar individualmente os doentes e para alertar a comunidade hospitalar para a presença de alergénios no local de trabalho e estabelecer medidas preventivas mais adequadas.

APA, Harvard, Vancouver, ISO, and other styles

50

Yao, Yao, Yibin Ying, and Jianfeng Ping. "Development of a Graphene Paper-Based Flexible Solid-Contact Lead Ion-Selective Electrode and its Application in Water." Transactions of the ASABE 62, no. 2 (2019): 245–52. http://dx.doi.org/10.13031/trans.12906.

Full text

Abstract:

Abstract. A graphene paper-based flexible solid-contact ion-selective electrode (SC-ISE) was developed to detect lead ion sensitively. Graphene paper obtained via a simple vacuum filtration method was used as the electrode substrate for direct coating of an ion-selective membrane. The Nernstian slope of the prepared paper-based potentiometric sensor toward lead ion detection was demonstrated as 29.4 mV per decade. A detection limit as low as 2.5 × 10-7 mol L-1 was achieved. Reversed chronopotentiometry and water layer test revealed that the graphene paper-based SC-ISE possessed excellent potential stability because of the hydrophobicity of graphene paper. Furthermore, reliable data were obtained from the detection of lead ion levels in real water samples using the graphene paper-based potentiometric sensor, which shows great potential in practical application. Keywords: Graphene paper, Heavy metal, Ion-selective electrode, Potentiometry, Water sample.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'MV contactor'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles