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Stornelli, Vincenzo, Gianluca Barile, Leonardo Pantoli, Massimo Scarsella, Giuseppe Ferri, Francesco Centurelli, Pasquale Tommasino i Alessandro Trifiletti. "A New VCII Application: Sinusoidal Oscillators". Journal of Low Power Electronics and Applications 11, nr 3 (8.07.2021): 30. http://dx.doi.org/10.3390/jlpea11030030.
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The aim of this paper is to prove that, through a canonic approach, sinusoidal oscillators based on second-generation voltage conveyor (VCII) can be implemented. The investigation demonstrates the feasibility of the design results in a pair of new canonic oscillators based on negative type VCII (VCII−). Interestingly, the same analysis shows that no canonic oscillator configuration can be achieved using positive type VCII (VCII+), since a single VCII+ does not present the correct port conditions to implement such a device. From this analysis, it comes about that, for 5-node networks, the two presented oscillator configurations are the only possible ones and make use of two resistors, two capacitors and a single VCII−. Notably, the produced sinusoidal output signal is easily available through the low output impedance Z port of VCII, removing the need for additional voltage buffer for practical use, which is one of the main limitations of the current mode (CM) approach. The presented theory is substantiated by both LTSpice simulations and measurement results using the commercially available AD844 from Analog Devices, the latter being in a close agreement with the theory. Moreover, low values of THD are given for a wide frequency range.
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Safari, Leila, Gianluca Barile, Vincenzo Stornelli i Giuseppe Ferri. "A Review on VCII Applications in Signal Conditioning for Sensors and Bioelectrical Signals: New Opportunities". Sensors 22, nr 9 (8.05.2022): 3578. http://dx.doi.org/10.3390/s22093578.
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This study reviews second-generation voltage conveyor (VCII)-based read-out circuits for sensors and bioelectrical signal conditioning from existing literature. VCII is the dual circuit of a second-generation current conveyor (CCII), which provides the possibility of processing signals in the current domain while providing output signals in the voltage form. The scope of this paper is to discuss the benefits and opportunities of new VCII-based read-out circuits over traditional ones and bioelectrical signals. The achieved main benefits compared to conventional circuits are the simpler read-out circuits, producing an output signal in a voltage form that can be directly used, improved accuracy, possibility of gain adjustment using a single grounded resistor, and the possibility of connecting several SiPM sensors to the readout circuit. The circuits studied in this paper include VCII- based read-out circuits suitable for all types of sensors configured in the current-mode Wheatstone bridge (CMWB) topology, the VCII-based read-out circuits solutions reported for silicon photomultiplier, spiral-shaped ultrasonic PVDF and differential capacitive sensors, and, finally, a simple readout circuitry for sensing bioelectrical signals. There are still not many VCII-based readout circuits, and we hope that the outcome of this study will enhance this area of research and inspire new ideas.
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Faseehuddin, Mohammad, Sadia Shireen, Sawal Hamid Md Ali i Worapong Tangsrirat. "Novel Lossless Positive-/Negative-Grounded Capacitance Multipliers Using VCII". Elektronika ir Elektrotechnika 29, nr 4 (7.09.2023): 19–26. http://dx.doi.org/10.5755/j02.eie.34304.
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In the presented research, the second-generation voltage conveyor (VCII) is used in the design of active capacitance multipliers. In this paper, three positive and one negative lossless grounded capacitance multipliers (GCMs) are designed. All of these GCMs are designed using two VCIIs, one capacitor, and two resistors. There is no need for any passive component matching to implement a GCM. The multiplication factor of GCMs can be set/varied by changing the values of two resistances as per requirement. Considering nonideal constraints, GCMs are analysed mathematically to evaluate the effect of nonideal current and voltage transfer gains on the performance of the proposed GCMs. Also, parasitic analysis is conducted to study the effect of VCII node impedance on the performance of the presented GCMs. The simulation analysis is performed using Cadence Virtuoso in 0.18 µm Silterra Malaysia process design kit (PDK). Additionally, the macro-model of commercially available integrated circuit, AD844, is used to design the proposed GCM-2 to further prove the theoretical findings.
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Safari, Leila, Gianluca Barile, Davide Colaiuda, Vincenzo Stornelli i Giuseppe Ferri. "Realization of an Electronically Tunable Resistor-Less Floating Inductance Simulator Using VCII". Electronics 11, nr 3 (19.01.2022): 312. http://dx.doi.org/10.3390/electronics11030312.
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In this paper, a new implementation of an electronically tunable resistor-less floating inductance simulator using a second-generation voltage conveyor (VCII) is presented. The proposed circuit is resistor-free (benefiting from the intrinsic resistors at the Y terminals of the employed VCIIs) and composed of three VCIIs and a single grounded capacitor. Using a control current (Icon), the value of impedance at the Y terminal of the VCII is varied, whereby the value of the simulated inductance is tuned. The proposed circuit is designed at a transistor level using 0.18 µm TSMC CMOS parameters and ±0.9 V supply voltage. PSpice simulations are carried out to confirm the effectiveness of the proposed circuit. For a range of Icon from 0 µA to 50 µA, the value of the simulated L can be varied from −576 µH to −324 µH and from +316 µH to +576 µH for negative and positive simulators, respectively, in the frequency range of 100 kHz–3 MHz. Favorably, the value of the series resistance remains below 76 Ω. Simulation results show an error value below 4.8% and power consumption variation is from 1.64 mW to 1.92 mW. Moreover, application of the proposed circuit as a standard band-pass RLC filter is also included.
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Barile, Stornelli, Ferri, Safari i D’Amico. "A New Rail-to-Rail Second Generation Voltage Conveyor". Electronics 8, nr 11 (5.11.2019): 1292. http://dx.doi.org/10.3390/electronics8111292.
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In this paper, a novel low voltage low power CMOS second generation voltage conveyor (VCII) with an improved voltage range at both the X and Z terminals is presented. The proposed VCII is formed by a current buffer based on a class AB regulated common-gate stage and a modified rail-to-rail voltage buffer. Spice simulation results using LFoundry 0.15 μm low-Vth CMOS technology with a ±0.9 V supply voltage are provided to demonstrate the validity of the designed circuit. Thanks to the class AB behavior, from a bias current of 10 µA, the proposed VCII is capable of driving 0.5 mA on the X terminal, with a total power consumption of 120 µW. The allowed voltage swing on the Z terminal is at least equal to ±0.83 V, while on the X terminals it is ±0.72 V. Both DC and AC voltage and current gains are provided, and time domain simulations, where the voltage conveyor is used as a transimpedance amplifier (TIA), are also presented. A final table that summarizes the main features of the circuit, comparing them with the literature, is also given.
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Safari, Leila, Gianluca Barile, Giuseppe Ferri i Vincenzo Stornelli. "A New Low-Voltage Low-Power Dual-Mode VCII-Based SIMO Universal Filter". Electronics 8, nr 7 (9.07.2019): 765. http://dx.doi.org/10.3390/electronics8070765.
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In this paper, a new low-voltage low-power dual-mode universal filter is presented. The proposed circuit is implemented using inverting current buffer (I-CB) and second-generation voltage conveyors (VCIIs) as active building blocks and five resistors and three capacitors as passive elements. The circuit is in single-input multiple-output (SIMO) structure and can produce second-order high-pass (HP), band-pass (BP), low-pass (LP), all-pass (AP), and band-stop (BS) transfer functions. The outputs are available as voltage signals at low impedance Z ports of the VCII. The HP, BP, AP, and BS outputs are also produced in the form of current signals at high impedance X ports of the VCIIs. In addition, the AP and BS outputs are also available in inverting type. The proposed circuit enjoys a dual-mode operation and, based on the application, the input signal can be either current or voltage. It is worth mentioning that the proposed filter does not require any component matching constraint and all sensitivities are low, moreover it can be easily cascadable. The simulation results using 0.18 μm CMOS technology parameters at a supply voltage of ±0.9 V are provided to support the presented theory.
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Safari, Leila, Gianluca Barile, Vincenzo Stornelli, Shahram Minaei i Giuseppe Ferri. "Towards Realization of a Low-Voltage Class-AB VCII with High Current Drive Capability". Electronics 10, nr 18 (18.09.2021): 2303. http://dx.doi.org/10.3390/electronics10182303.
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In this paper, the implementation of a low-voltage class AB second generation voltage conveyor (VCII) with high current drive capability is presented. Simple realization and good overall performance are the main features of the proposed circuit. Proper solutions and techniques were used to achieve high signal swing and high linearity at Y, X and Z ports of VCII as well as low-voltage operation. The operation of the proposed VCII was verified through SPICE simulations based on TSMC 0.18 µm CMOS technology parameters and a supply voltage of ±0.9 V. The small signal impedance values were 973 Ω, 120 kΩ and 217 Ω at Y, X and Z ports, respectively. The maximum current at the X port was ±10 mA with maximum total harmonic distortion (THD) of 2.4% at a frequency of 1 MHz. Considering a bias current (IB) of 29 µA and output current at the X port (IX) of 10 mA, the current drive capability (IX/IB) of about 345 was achieved at the X port. The voltage swing at the Z port was (−0.4, 0.4) V. The THD value at the Z port for an input signal with 0.8 V peak-to-peak value and frequency of 1 MHz was 3.9%. The total power consumption was 0.393 µW.
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Barile, Gianluca, Leila Safari, Giuseppe Ferri i Vincenzo Stornelli. "A VCII-Based Stray Insensitive Analog Interface for Differential Capacitance Sensors". Sensors 19, nr 16 (14.08.2019): 3545. http://dx.doi.org/10.3390/s19163545.
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In this paper, a novel approach to implement a stray insensitive CMOS interface for differential capacitive sensors is presented. The proposed circuit employs, for the first time, second-generation voltage conveyors (VCIIs) and produces an output voltage proportional to differential capacitor changes. Using VCIIs as active devices inherently allows the circuit to process the signal in the current domain, and hence, to benefit from its intrinsic advantages, such as high speed and simple implementation, while still being able to natively interface with voltage mode signal processing stages at necessity. The insensitiveness to the effects of parasitic capacitances is achieved through a simple feedback loop. In addition, the proposed circuit shows a very simple and switch-free structure (which can be used for both linear and hyperbolic sensors), improving its accuracy. The readout circuit was designed in a standard 0.35 μm CMOS technology under a supply voltage of ±1.65 V. Before the integrated circuit fabrication, to produce tangible proof of the effectiveness of the proposed architecture, a discrete version of the circuit was also prototyped using AD844 and LF411 to implement a discrete VCII. The achieved measurement results are in good agreement with theory and simulations, showing a constant sensitivity up to 412 mV/pF, a maximum linearity error of 1.9%FS, and acknowledging a good behavior with low baseline capacitive sensors (10 pF in the proposed measurements). A final table is also given to summarize the key specs of the proposed work comparing them to the available literature.
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Stornelli, V., L. Safari, G. Barile i G. Ferri. "A new VCII based grounded positive/negative capacitance multiplier". AEU - International Journal of Electronics and Communications 137 (lipiec 2021): 153793. http://dx.doi.org/10.1016/j.aeue.2021.153793.
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Barile, Gianluca, Giuseppe Ferri, Leonardo Pantoli, Mattia Ragnoli, Vincenzo Stornelli, Leila Safari, Francesco Centurelli, Pasquale Tommasino i Alessandro Trifiletti. "Low power class-AB VCII with extended dynamic range". AEU - International Journal of Electronics and Communications 146 (marzec 2022): 154120. http://dx.doi.org/10.1016/j.aeue.2022.154120.
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Yuce, Erkan, Leila Safari, Shahram Minaei, Giuseppe Ferri, Gianluca Barile i Vincenzo Stornelli. "A New Simulated Inductor with Reduced Series Resistor Using a Single VCII±". Electronics 10, nr 14 (15.07.2021): 1693. http://dx.doi.org/10.3390/electronics10141693.
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This paper presents a new realization of a grounded simulated inductor using a single dual output second-generation voltage conveyor (VCII±) as an active building block, two resistors and one grounded capacitor. The main characteristic of the proposed circuit is that the value of the series resistor can be significantly reduced. Thus, it has the property of improved low-frequency performance. Another feature is the use of a grounded capacitor that makes the proposed circuit attractive for integrated circuit (IC) realization. A simple CMOS implementation of the required VCII± is used. However, a single passive component-matching condition is required for the proposed structure. As an application example, a standard fifth-order high-pass ladder filter is also given. SPICE simulations using 0.18 μm CMOS technology parameters and a supply voltage of ±0.9 V as well as experimental verifications, are carried out to support the theory.
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Al-Absi, M. A. "Realization of inverse filters using second generation voltage conveyor (VCII)". Analog Integrated Circuits and Signal Processing 109, nr 1 (26.05.2021): 29–32. http://dx.doi.org/10.1007/s10470-021-01874-3.
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Stornelli, Vincenzo, Gianluca Barile i Alfiero Leoni. "A Novel General Purpose Combined DFVF/VCII Based Biomedical Amplifier". Electronics 9, nr 2 (14.02.2020): 331. http://dx.doi.org/10.3390/electronics9020331.
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We here present a 0.15 µm CMOS high input impedance and low noise AC coupled flipped voltage follower-based amplifier for high integration level in integrated circuits in a wide range of sensing applications. With such a circuit, it is possible to achieve a high level of integration, thanks to the absence of passive resistors, and also to implement a very high input impedance without capacitive feedback thanks to bootstrap operation, thus offering a very low high-pass cutoff frequency. Simulated results with a proven and well modeled standard technology show a whole circuit input-referred noise of 5.4 µVrms. The bias voltage is ±0.6 V with a total power consumption of the single amplifier of 20 µW. The very low circuit complexity allows a very low estimated reduced area occupation giving, as a general example, the possibility of integrating an array of up to thousands of channels for biomedical applications. Detailed simulation results, PVT analysis and comparison tables are also presented in the paper.
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Safari, Leila, Erkan Yuce, Shahram Minaei, Giuseppe Ferri i Vincenzo Stornelli. "A second‐generation voltage conveyor (VCII)–based simulated grounded inductor". International Journal of Circuit Theory and Applications 48, nr 7 (25.02.2020): 1180–93. http://dx.doi.org/10.1002/cta.2770.
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Safari, Leila, Gianluca Barile, Giuseppe Ferri, Mattia Ragnoli i Vincenzo Stornelli. "A New Realization of Electronically Tunable Multiple-Input Single-Voltage Output Second-Order LP/BP Filter Using VCII". Electronics 11, nr 4 (18.02.2022): 646. http://dx.doi.org/10.3390/electronics11040646.
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In this paper, a new realization of electronically tunable voltage output second-order low-pass (LP) and band-pass (BP) filter is presented. The circuit has a multiple-input single-output structure, and LP and BP outputs are provided using the same structure. One electronically variable second-generation voltage conveyor (VCII), whose impedance at the Y port can be electronically varied using a control current (Icon), two capacitors, and one resistor are used. By changing the value of Icon, the impedance value at the Y port can be electronically varied; therefore, the value of ω0 can be tuned. This feature helps to reduce the number of passive components used. Interestingly, the LP and BP outputs are provided at the low-impedance Z port of the VCII, and there is no need for an extra voltage buffer for practical use. The circuit enjoys a simple realization consisting of only 24 MOS transistors. Simulation results using PSpice and 0.18 μm CMOS parameters are provided. The value of ω0 can be varied from 1.2 MHz to 1.7 MHz, while Icon varies from 0 to 50 µA, with a power consumption variation from 244 µW to 515 µW.
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Scarsella, Massimo, Gianluca Barile, Vincenzo Stornelli, Leila Safari i Giuseppe Ferri. "A Survey on Current-Mode Interfaces for Bio Signals and Sensors". Sensors 23, nr 6 (16.03.2023): 3194. http://dx.doi.org/10.3390/s23063194.
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In this study, a review of second-generation voltage conveyor (VCII) and current conveyor (CCII) circuits for the conditioning of bio signals and sensors is presented. The CCII is the most known current-mode active block, able to overcome some of the limitations of the classical operational amplifier, which provides an output current instead of a voltage. The VCII is nothing more than the dual of the CCII, and for this reason it enjoys almost all the properties of the CCII but also provides an easy-to-read voltage as an output signal. A broad set of solutions for relevant sensors and biosensors employed in biomedical applications is considered. This ranges from the widespread resistive and capacitive electrochemical biosensors now used in glucose and cholesterol meters and in oximetry to more specific sensors such as ISFETs, SiPMs, and ultrasonic sensors, which are finding increasing applications. This paper also discusses the main benefits of this current-mode approach over the classical voltage-mode approach in the realization of readout circuits that can be used as electronic interfaces for different types of biosensors, including higher circuit simplicity, better low-noise and/or high-speed performance, and lower signal distortion and power consumption.
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Safari, Leila, Gianluca Barile, Giuseppe Ferri i Vincenzo Stornelli. "Traditional Op-Amp and new VCII: A comparison on analog circuits applications". AEU - International Journal of Electronics and Communications 110 (październik 2019): 152845. http://dx.doi.org/10.1016/j.aeue.2019.152845.
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Ferri, Giuseppe, Leila Safari, Gianluca Barile, Massimo Scarsella i Vincenzo Stornelli. "New Resistor-Less Electronically Controllable ±C Simulator Employing VCII, DVCC, and a Grounded Capacitor". Electronics 11, nr 2 (17.01.2022): 286. http://dx.doi.org/10.3390/electronics11020286.
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In this paper, a new realization of electronically controllable positive and negative floating capacitor multiplier (±C) is presented. The peculiarity of the presented topology is that, for the first time, it implements a floating equivalent capacitor between its two input terminals, rather than a grounded one. To achieve the best performance, we simultaneously use the advantages provided by the current conveyor and its dual circuit, the voltage conveyor. The proposed topology is resistor free and employs one dual-output second-generation voltage conveyor (VCII±) and one electronically tunable differential voltage current conveyor (E-DVCC) as active building blocks (ABBs) and a single grounded capacitor. The value of the simulated capacitor is controlled by means of a control voltage VC which is used to control the current gain between X and Z terminals of E-DVCC. The circuit is free from any matching condition. A complete non-ideal analysis by considering parasitic impedances as well as non-ideal current and voltage gains of the used ABBs is presented. The proposed circuit is designed at the transistor level in 0.18 µm and ±0.9 V supply voltage. Simulation results using the SPICE program show a multiplication factor ranging from ±10 to ±25.4 with a maximum error of 0.56%. As an example, the application of the achieved floating capacitor as a standard high pass filter is also included.
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Stornelli, V., L. Safari, G. Barile i G. Ferri. "A New Extremely Low Power Temperature Insensitive Electronically Tunable VCII-Based Grounded Capacitance Multiplier". IEEE Transactions on Circuits and Systems II: Express Briefs 68, nr 1 (styczeń 2021): 72–76. http://dx.doi.org/10.1109/tcsii.2020.3005524.
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Pullano, Salvatore A., Antonino S. Fiorillo, Gianluca Barile, Vincenzo Stornelli i Giuseppe Ferri. "A Second-Generation Voltage-Conveyor-Based Interface for Ultrasonic PVDF Sensors". Micromachines 12, nr 2 (20.01.2021): 99. http://dx.doi.org/10.3390/mi12020099.
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Exploiting the transmission and reception of low frequency ultrasounds in air is often associated with the innate echolocating abilities of some mammals, later emulated with sophisticated electronic systems, to obtain information about unstructured environments. Here, we present a novel approach for the reception of ultrasounds in air, which exploits a piezopolymer broadband sensor and an electronic interface based on a second-generation voltage conveyor (VCII). Taking advantage of its capability to manipulate both voltage and current signals, in this paper, we propose an extremely simple interface that presents a sensitivity level of about −100 dB, which is in line with commercially available references. The presented results are obtained without any filtration stage. The second-generation voltage conveyor active device is implemented through a commercially available AD844, with a supply voltage of ±15 V.
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Stornelli, Vincenzo, Leonardo Pantoli, Gianluca Barile, Alfiero Leoni i Emanuele D’Amico. "Silicon Photomultiplier Sensor Interface Based on a Discrete Second Generation Voltage Conveyor". Sensors 20, nr 7 (5.04.2020): 2042. http://dx.doi.org/10.3390/s20072042.
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This work presents the design of a discrete second-generation voltage conveyor (VCII) and its capability to be used as electronic interface for silicon photomultipliers. The design addressed here exploits directly at the transistor level, with commercial components, the proposed interface; the obtained performance is valuable considering both the discrete elements and the application. The architecture adopted here realizes a transimpedance amplifier that is also able to drive very high input impedance, as usually requested by photons detection. Schematic and circuital design of the discrete second-generation voltage conveyor is presented and discussed. The complete circuit interface requires a bias current of 20 mA with a dual 5V supply voltage; it has a useful bandwidth of about 106 MHz, and considering also the reduced dimensions, it is a good candidate to be used in portable applications without the need of high-cost dedicated integrated circuits.
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Mey, Alexandra R., Elizabeth E. Wyckoff, Lindsey A. Hoover, Carolyn R. Fisher i Shelley M. Payne. "Vibrio cholerae VciB Promotes Iron Uptake via Ferrous Iron Transporters". Journal of Bacteriology 190, nr 17 (27.06.2008): 5953–62. http://dx.doi.org/10.1128/jb.00569-08.
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ABSTRACT Vibrio cholerae uses a variety of strategies for obtaining iron in its diverse environments. In this study we report the identification of a novel iron utilization protein in V. cholerae, VciB. The vciB gene and its linked gene, vciA, were isolated in a screen for V. cholerae genes that permitted growth of an Escherichia coli siderophore mutant in low-iron medium. The vciAB operon encodes a predicted TonB-dependent outer membrane receptor, VciA, and a putative inner membrane protein, VciB. VciB, but not VciA, was required for growth stimulation of E. coli and Shigella flexneri strains in low-iron medium. Consistent with these findings, TonB was not needed for VciB-mediated growth. No growth enhancement was seen when vciB was expressed in an E. coli or S. flexneri strain defective for the ferrous iron transporter Feo. Supplying the E. coli feo mutant with a plasmid encoding either E. coli or V. cholerae Feo, or the S. flexneri ferrous iron transport system Sit, restored VciB-mediated growth; however, no stimulation was seen when either of the ferric uptake systems V. cholerae Fbp and Haemophilus influenzae Hit was expressed. These data indicate that VciB functions by promoting iron uptake via a ferrous, but not ferric, iron transport system. VciB-dependent iron accumulation via Feo was demonstrated directly in iron transport assays using radiolabeled iron. A V. cholerae vciB mutant did not exhibit any growth defects in either in vitro or in vivo assays, possibly due to the presence of other systems with overlapping functions in this pathogen.
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McAteer, Rebecca, Shala Sundaram, Shantie Harkisoon i Julia Miller. "Videoconference Interviews: A Timely Primary Care Residency Selection Approach". Journal of Graduate Medical Education 12, nr 6 (1.12.2020): 737–44. http://dx.doi.org/10.4300/jgme-d-20-00248.1.
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ABSTRACT Background Videoconference interviews (VCIs) are increasingly being used in the selection process of residency program candidates across a number of medical specialties, but nevertheless remain an underutilized approach, particularly in the field of primary care. Objective This retrospective data review with cost analysis explores financial and acceptability outcomes of VCI implementation over a 9-year period. Methods VCIs were incorporated into the recruitment process at a community-based academic family medicine residency program in 2011, whereby suitable candidates were selected for VCIs after Electronic Residency Application Service (ERAS) application review. Based on the outcome of VCI, candidates were invited via a structured interview tool for a subsequent in-person interviews to determine final rank decisions. Costs of the interview process were tracked, as well as perceptions of VCIs. Results VCI implementation over 9 years demonstrated a median 48% reduction of in-person interviews—or 95 applicants eliminated out of a total 195 VCIs performed. This represents a mean annual direct cost savings estimated at $9,154, equating to a 55% reduction in allocated program costs, in addition to indirect cost savings to both applicants and the program. Conclusions Compared to exclusively in-person interviewing, the utilization of VCIs is potentially more cost-effective for residency programs and candidates, while creating a more personal experience for applicants early in the recruitment process. Limited data of acceptability among faculty and candidates is generally favorable but remains mixed.
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Kolyada, L. G., E. V. Tarasyuk i N. L. Kalugina. "Technology of Packing Materials for Metal Products". Materials Science Forum 870 (wrzesień 2016): 454–59. http://dx.doi.org/10.4028/www.scientific.net/msf.870.454.
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Survey objective: development of methods for manufacture of combined packaging materials containing volatile corrosion inhibitors (VCIs) and estimation of their corrosion resistance. The investigation outcome includes prototypes of the combined packaging material containing VCIs, developed optimal paper manufacturing design parameters, estimation of their protective properties compared with those of foreign equivalents. Based on the investigation outcome, the following optimal concentrations of inhibitor work solutions are selected to provide protective properties of the obtained materials: 4 mass. % in water solution for VCI-1 and VCI-2; 10 vol. % in nefras for VCI-3. It was found that inhibitor work solutions might be preferably applied on the base paper with a roller because of a low viscosity of inhibitor work solutions and even the inhibitor application obtainable with this method. The optimum temperature value for drying of the combined packaging material is 80 oС because it virtually does not result in change of inhibitor residuals. Tests according to GOST 9.054-75 prove the corrosion-resistive efficiency of the combined packaging materials obtained. Estimation of corrosion-resistive properties of the studied materials has also established that paper covered with VCI-2 is of a universal character as it features high protective properties related to cold and hot-rolled steels. Corrosion inhibiting properties of test samples of combined materials with VCI-1 and VCI-2 are equal to those of foreign equivalents.
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Lokshina, A. B., D. A. Grishina i V. V. Zakharov. "Vascular cognitive impairment: issues of diagnosis and treatment". Neurology, Neuropsychiatry, Psychosomatics 15, nr 2 (30.04.2023): 106–13. http://dx.doi.org/10.14412/2074-2711-2023-2-106-113.
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Vascular brain diseases are one of the leading causes of death and disability in developed countries. Along with acute disturbance of cerebral circulation, chronic cerebrovascular diseases, which manifest as vascular cognitive impairment (VCI), are of great medical and social importance. VCIs include a wide range of cognitive impairments (CI) ranging from subjective CI to vascular and mixed dementia. The article discusses pathogenetic and clinical variants, approaches to the diagnosis of VCIs, and provides their modern classification. The features of CI, typical for chronic cerebrovascular insufficiency, are described, such as a slowdown in the rate of mental activity and disorders of frontal executive functions in combination with behavioral and emotional disorders. The issues of treatment of VCI are discussed, which should be comprehensive and include correction of the underlying vascular disease, non-drug (regular physical activity, smoking cessation, cognitive training) and drug treatments aimed at improving cognitive functions. The possibilities of modern neuroprotective and symptomatic therapy of CI, including the use of Cellex®, are shown.
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Barile, Gianluca, Leila Safari, Leonardo Pantoli, Vincenzo Stornelli i Giuseppe Ferri. "Electronically Tunable First Order AP/LP and LP/HP Filter Topologies Using Electronically Controllable Second Generation Voltage Conveyor (CVCII)". Electronics 10, nr 7 (30.03.2021): 822. http://dx.doi.org/10.3390/electronics10070822.
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In this paper two new first order filter topologies realizing low-pass/all-pass (LP/AP) and low-pass/high-pass (LP/HP) outputs using electronically controllable second generation voltage conveyors (CVCIIs) are presented. Unlike second generation voltage conveyors (VCII), in CVCII each performance parameter, including ports, parasitic impedances, current and/or voltage gains can be electronically varied. Here, in particular, the proposed filter topologies are based on two CVCIIs, one resistor and one capacitor. In the first topology VLP/IAP/VAP and in the second topology ILP/VLP/IHP/VHP outputs are achievable, respectively. However, the current and voltage outputs are not achievable simultaneously and a floating capacitor is used. A control current (Icon) is used to change the first CVCII Y port impedance, which sets the filter −3 dB frequency (f0) of all the outputs. Moreover, in the second topology, the gains of HP and AP outputs are electronically adjusted by means of a control voltage (Vcon). Favorably, no restricting matching condition is necessary. PSpice simulations using 0.18 µm CMOS technology and supply voltages of ±0.9V show that by changing Icon from 0.5 µA to 50 µA, f0 is varied from 89 kHz to 1 MHz. Similarly, for a Vcon variation from −0.9 V to 0.185 V, the gains of IAP and IHP vary from 30 dB to 0 dB and those of VAP and VHP vary from 100 dB to 20 dB. The total harmonic distortion (THD) is about 8%. The power consumption is from 0.385 mW to 1.057 mW.
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Kazmers, Andris, Lloyd A. Jacobs i Anthony J. Perkins. "Pulmonary Embolism in Veterans Affairs Medical Centers: Is Vena Cava Interruption Underutilized?" American Surgeon 65, nr 12 (grudzień 1999): 1171–75. http://dx.doi.org/10.1177/000313489906501217.
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Veterans with venous thrombosis or pulmonary embolism (PE) were evaluated using Veterans Affairs patient treatment file (PTF) data from fiscal years 1990–1995, inclusive, to define outcomes for those with PE. The specific aims of the study were to define how often those with PE underwent vena cava interruption (VCI) and whether VCI affected in-hospital mortality rates. Outcomes were defined using PTF data and Patient Management Category (PMC) software for 26,132 veterans discharged from all Veterans Affairs Medical Centers (VAMCs) with venous thromboembolism, which included a subset of 4,882 patients identified by both PTF data and PMC software to have PE. PMC software also generated measures of illness severity, patient complexity (PMC count), and resource utilization (called resource intensity scale) for each hospital admission. The in-hospital mortality rate for those with PE was 15.9 per cent (775 of 4882). Only 157 VCIs were performed in those with PE which constituted 3.2 per cent of the latter group. Those with PE who had VCI experienced a 13.4 per cent unadjusted in-hospital mortality rate (21 of 157) versus a 16 per cent unadjusted mortality rate without VCI (754/4725; not significant). In a logistic regression model of in-hospital mortality in those with PE, increasing age and illness severity were directly related to mortality, whereas VCI was independently associated with reduced mortality. The odds of death were reduced by 0.482 (0.287–0.807, 95% limits) for patients with PE who underwent VCI (P < 0.005). Utilization of VCI varied among VAMCs: the hospital rates that VCI were performed in those with PE ranged from 0 to 16.7 per cent. Mortality associated with PE was substantial in VAMCs, and VCI was independently associated with reduced in-hospital mortality. The low percentage of veterans with pulmonary embolism who underwent VCI was surprising. VCI may be underutilized in veterans with PE.
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Sumantri, I. Ketut, I. Putu Sudana, A. A. N. Bagus Dwirandra i I. Gde Ary Wirajaya. "Sustainability business practices based on tri hita karana and its accountability". Linguistics and Culture Review 6 (20.01.2022): 631–54. http://dx.doi.org/10.21744/lingcure.v6ns1.2109.
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Purpose of the study is to gain an understanding of how Village Credit Institution (VCI) apply the concept of sustainability business practices (SBP) based on the existence of VCIs inspired by Tri Hita Karana (THK) and their accountability. This study adopts an ethnomethodological approach, aiming to obtain a portrait of VCI business practices in daily life settings. The results of this study found that sustainable business practices and VCI accountability in the economic dimension are seen in the economic implications for their stakeholders, in line with the concept of “pang pade payu”, in the social dimension, it is seen in social care and various community empowerment programs in line with the concept of “segalak segilik selunglung sebayantaka, paras paros sarpanaya". In the ecological dimension, the involvement of VCI in an effort to preserve the environment, both physical and non-physical, is in line with the Hindu belief, namely "skala-niskala". In the spiritual dimension, it is reflected in the ritual activities of the “panca yadnya” as offerings to God as the highest entity. Business units must view all aspects of life as integral and interrelated with one another. SBP based on THK results in holistic accountability for sustainability.
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Baniya, Binod, Qiuhong Tang, Ximeng Xu, Gebremedhin Haile i Gyan Chhipi-Shrestha. "Spatial and Temporal Variation of Drought Based on Satellite Derived Vegetation Condition Index in Nepal from 1982–2015". Sensors 19, nr 2 (21.01.2019): 430. http://dx.doi.org/10.3390/s19020430.
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Identification of drought is essential for many environmental and agricultural applications. To further understand drought, this study presented spatial and temporal variations of drought based on satellite derived Vegetation Condition Index (VCI) on annual (Jan–Dec), seasonal monsoon (Jun–Nov) and pre-monsoon (Mar–May) scales from 1982–2015 in Nepal. The Vegetation Condition Index (VCI) obtained from NOAA, AVHRR (National Oceanic and Atmospheric Administration, Advanced Very High Resolution Radiometer) and climate data from meteorological stations were used. VCI was used to grade the drought, and the Mann–Kendall test and linear trend analysis were conducted to examine drought trends and the Pearson correlation between VCI and climatic factors (i.e., temperature and precipitation) was also acquired. The results identified that severe drought was identified in 1982, 1984, 1985 and 2000 on all time scales. However, VCI has increased at the rate of 1.14 yr−1 (p = 0.04), 1.31 yr−1 (p = 0.03) and 0.77 yr−1 (p = 0.77) on the annual, seasonal monsoon and pre-monsoon scales, respectively. These increased VCIs indicated decreases in drought. However, spatially, increased trends of drought were also found in some regions in Nepal. For instance, northern areas mainly in the Trans-Himalayan regions identified severe drought. The foothills and the lowlands of Terai (southern Nepal) experienced normal VCI, i.e., no drought. Similarly, the Anomaly Vegetation Condition Index (AVCI) was mostly negative before 2000 which indicated deficient soil moisture. The exceedance probability analysis results on the annual time scale showed that there was a 20% chance of occurring severe drought (VCI ≤ 35%) and a 35% chance of occurring normal drought (35% ≤ VCI ≤ 50%) in Nepal. Drought was also linked with climates in which temperature on the annual and seasonal monsoon scales was significant and positively correlated with VCI. Drought occurrence and trends in Nepal need to be further studied for comprehensive information and understanding.
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Vigdorovich, V. I., L. E. Tsygankova i L. G. Knyazeva. "Universality of volatile corrosion inhibitors applied requirements of agricultural production". Rossiiskaia selskokhoziaistvennaia nauka, nr 2 (9.04.2019): 64–68. http://dx.doi.org/10.31857/s2500-26272019264-68.
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Aqualitative and quantitative system of criteria for evaluating the universality of volatile metal corrosion inhibitors (VCIs) applied to agricultural production conditions was developed. The system of qualitative criteria for universalism includes: 1- an assessment of the effectiveness of corrosion inhibition of metals under the conditions of the action of corrosion-specific stimulants present in the vapor- gas phase separately or together; 2 - suppression of various types of local corrosion caused by them in the composition of a corrosive medium; 3 - suppression in specific conditions of general and local corrosion of contacting metallic structural materials of various nature; 4 - observance of acceptable specific characteristics of VCI: ecological, class-related hazards, influence on chemical oxygen consumption (COC) and biochemical oxygen demand for the biodegradation of substances by microorganisms (BOD5). The system of quantitative criteria for universalism of the VCIs includes quantitative parameters for all the proposed qualitative items. A simplified assessment, taking into account only a part of the criteria for characterizing partially universal inhibitors, is proposed to be applied to the conditions of agricultural production. The experimental data for the volatile inhibitor IFKhAN-114 are given as an example of the effectiveness of the proposed criteria. It was shown that IFKhAN-114 is a partially universal inhi-bitor.
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Genovez, Mario Celso, Luiz Henrique Araujo, Tiago Dinis Pinto i Radim Hrdina. "Applying a new concept of corrosion protection in the presence of water: hydrojetting application – effectiveness lab test". Anti-Corrosion Methods and Materials 64, nr 1 (3.01.2017): 109–17. http://dx.doi.org/10.1108/acmm-03-2015-1509.
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Purpose This paper aims to describe the results of lab testing of a newly developed organic inhibitor V-active VCIs. The findings demonstrate that it is possible to eliminate or reduce the oxidizing action of water, thereby extending the allowable time before painting after hydrojetting, and that the new corrosion inhibitor technology does not interfere with the final quality of paint adhesion. Design/methodology/approach Metallic specimens were treated/washed in standard lab condition. A 2 per cent V-active VCI SPH1712 water solution was prepared by diluting the inhibitor in industrial water. Metal sample plates were examined after blasting and after subsequent drying, and were submitted to the paint adhesion tests, cathodic disbondment, total soluble salts, time for formation of flash rust and cyclic corrosion test type III (20 cycles), to evaluate the duration of temporary protection and oxidation prevention and influence on paint adherence. Findings Using the V-active VCI proposed technology, it was possible to minimize or eliminate the oxidizing action of the water when the metal is exposed to saline moisture in a closed environment, extending the acceptable time before painting without interfering with the final quality of painting. Practical implications The proposed technology allows an increase in the prepared (wet blasted) steel surface during cleaning and preparation, thereby reducing labor and product costs, and reduces water consumption during the preparation process. Practical applications in the shipbuilding, ship maintenance and oil and gas production industries include the preservation of internal tubes and pipes, protection during hydrostatic test processes and cleaning with water and corrosion prevention in diesel tanks contaminated with water. Originality/value The intent of this paper is to present the obtained results for a new formulation of organic chemical inhibitors that use water as the application medium. In addition to this property, this group of organic inhibitors maintains the properties of volatile inhibitors. Thus, these compounds are generically known as V-active VCIs.
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Genovez, Mário Celso, Luiz Henrique Araújo, Tiago Dinis Pinto i Radim Hrdina. "New concept of corrosion protection in the presence of water: V-active VCI. Concept and application". Anti-Corrosion Methods and Materials 62, nr 1 (5.01.2015): 53–58. http://dx.doi.org/10.1108/acmm-06-2013-1271.
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Purpose – This work describes test results that were obtained using a newly-developed type of organic inhibitor: V-active VCIs. The findings demonstrate that is possible to eliminate or reduce the oxidizing action of water, thereby extending the allowable time before painting after hydrojetting, and that the new corrosion inhibitor technology does not interfere with the final quality of paint adhesion. Design/methodology/approach – Metallic specimens were treated/washed by hydrojet (35000 Psi). It was employed as a 2 per cent V-active VCI SPH 1,712 water solution by dilution of the inhibitor in industrial water. Metal sample plates were examined after blasting and after subsequent drying, and were submitted to the paint adhesion tests, to evaluate the duration of temporary protection, oxidation prevention and influence on the adherence of paint (pull off). Findings – Using the V-active VCI proposed technology, it was possible to minimize or eliminate the oxidizing action of the water when the metal is exposed to the saline moisture in a closed environment, extending the acceptable time before painting without interference in the final quality of painting. Practical implications – The proposed technology allows to the area of prepared (wet blasted) steel surface to be increased during cleaning and preparation, thereby reducing labor and product costs, and reduces water consumption during the preparation process. Practical applications in the shipbuilding, ship maintenance and oil and gas production industries, include the preservation of internal tubes and pipes, protection during hydrostatic test processes and cleaning with water and corrosion prevention in diesel tanks contaminated with water. Originality/value – The intent of this paper is to present the obtained results for a new formulation of organic chemical inhibitors that use water medium as the application method. In addition to this property, this group of organic inhibitors maintains the property of volatile inhibitors. Thus, these compounds are generically known as V-active VCI.
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Kiran, Manish, Arpit Jariwala i Carlos A. Wigderowitz. "Evaluation of the Cementation Index as a Predictor of Failure in Coonrad-Morrey Total Elbow Arthroplasty". Advances in Orthopedic Surgery 2014 (17.03.2014): 1–4. http://dx.doi.org/10.1155/2014/243823.
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Background. The aim of this study is to objectively evaluate the quality of cementation by a novel method called the cementation index and assess its utility as a predictor of failure. Materials and Methods. Fifty elbows with primary Coonrad-Morrey total elbow replacement were included. The quality of cementing was assessed by novel methods, the vertical and horizontal cementation index, which were statistically evaluated as predictors of failure. The mean period of followup was 8.08±2.95 years (range: from 5.08 to 10.25 years). Results. The mean vertical cementation index of the humerus (vCIH) was 1.22 ± 0.28 and that of the ulna (vCIU) was 1.10±0.18. Radiolucent zones were noted in two cases in the humerus with a horizontal cementation index of 0.21 and 0.14, respectively. Both of the cementation indices were not found to be statistically significant predictors of failure (P>0.05). The five-year survival rate was 94%. Discussion and Conclusion. The cementation index, being a ratio, reduces the confounding effect of taking radiographs in different positions of the limb with different magnification in followup radiographs. It is an easy and objective method of assessment of cementation, the results of which need to be validated by a larger study.
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Bergauer, Thomas, Josef Hrubec, Manfred Jeitler, Manfred Krammer i Gerald Badurek. "VCI 2010". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 628, nr 1 (luty 2011): vii. http://dx.doi.org/10.1016/j.nima.2010.06.276.
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Qiu, Chenxi, Onder Albayram, Asami Kondo, Bin Wang, Nami Kim, Ken Arai, Cheng-Yu Tsai i in. "Cis P-tau underlies vascular contribution to cognitive impairment and dementia and can be effectively targeted by immunotherapy in mice". Science Translational Medicine 13, nr 596 (2.06.2021): eaaz7615. http://dx.doi.org/10.1126/scitranslmed.aaz7615.
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Compelling evidence supports vascular contributions to cognitive impairment and dementia (VCID) including Alzheimer’s disease (AD), but the underlying pathogenic mechanisms and treatments are not fully understood. Cis P-tau is an early driver of neurodegeneration resulting from traumatic brain injury, but its role in VCID remains unclear. Here, we found robust cis P-tau despite no tau tangles in patients with VCID and in mice modeling key aspects of clinical VCID, likely because of the inhibition of its isomerase Pin1 by DAPK1. Elimination of cis P-tau in VCID mice using cis-targeted immunotherapy, brain-specific Pin1 overexpression, or DAPK1 knockout effectively rescues VCID-like neurodegeneration and cognitive impairment in executive function. Cis mAb also prevents and ameliorates progression of AD-like neurodegeneration and memory loss in mice. Furthermore, single-cell RNA sequencing revealed that young VCID mice display diverse cortical cell type–specific transcriptomic changes resembling old patients with AD, and the vast majority of these global changes were recovered by cis-targeted immunotherapy. Moreover, purified soluble cis P-tau was sufficient to induce progressive neurodegeneration and brain dysfunction by causing axonopathy and conserved transcriptomic signature found in VCID mice and patients with AD with early pathology. Thus, cis P-tau might play a major role in mediating VCID and AD, and antibody targeting it may be useful for early diagnosis, prevention, and treatment of cognitive impairment and dementia after neurovascular insults and in AD.
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Kawai, Alison Tse, Michael S. Calderwood, Robert Jin, Stephen B. Soumerai, Louise E. Vaz, Donald Goldmann i Grace M. Lee. "Impact of the Centers for Medicare and Medicaid Services Hospital-Acquired Conditions Policy on Billing Rates for 2 Targeted Healthcare-Associated Infections". Infection Control & Hospital Epidemiology 36, nr 8 (24.04.2015): 871–77. http://dx.doi.org/10.1017/ice.2015.86.
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BACKGROUNDThe 2008 Centers for Medicare & Medicaid Services hospital-acquired conditions policy limited additional payment for conditions deemed reasonably preventable.OBJECTIVETo examine whether this policy was associated with decreases in billing rates for 2 targeted conditions, vascular catheter-associated infections (VCAI) and catheter-associated urinary tract infections (CAUTI).STUDY POPULATIONAdult Medicare patients admitted to 569 acute care hospitals in California, Massachusetts, or New York and subject to the policy.DESIGNWe used an interrupted times series design to assess whether the hospital-acquired conditions policy was associated with changes in billing rates for VCAI and CAUTI.RESULTSBefore the policy, billing rates for VCAI and CAUTI were increasing (prepolicy odds ratio per quarter for VCAI, 1.17 [95% CI, 1.11–1.23]; for CAUTI, 1.19 [1.16–1.23]). The policy was associated with an immediate drop in billing rates for VCAI and CAUTI (odds ratio for change at policy implementation for VCAI, 0.75 [95% CI, 0.69–0.81]; for CAUTI, 0.87 [0.79–0.96]). In the postpolicy period, we observed a decreasing trend in the billing rate for VCAI and a leveling-off in the billing rate for CAUTI (postpolicy odds ratio per quarter for VCAI, 0.98 [95% CI, 0.97–0.99]; for CAUTI, 0.99 [0.97–1.00]).CONCLUSIONSThe Centers for Medicare & Medicaid Services hospital-acquired conditions policy appears to have been associated with immediate reductions in billing rates for VCAI and CAUTI, followed by a slight decreasing trend or leveling-off in rates. These billing rates, however, may not correlate with changes in clinically meaningful patient outcomes and may reflect changes in coding practices.Infect. Control Hosp. Epidemiol. 2015;36(8):871–877
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Menne, Stephan, Carol A. Roneker, Michael Roggendorf, John L. Gerin, Paul J. Cote i Bud C. Tennant. "Deficiencies in the Acute-Phase Cell-Mediated Immune Response to Viral Antigens Are Associated with Development of Chronic Woodchuck Hepatitis Virus Infection following Neonatal Inoculation". Journal of Virology 76, nr 4 (15.02.2002): 1769–80. http://dx.doi.org/10.1128/jvi.76.4.1769-1780.2002.
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ABSTRACT In vitro proliferation of peripheral blood mononuclear cells was used to measure virus-specific cell-mediated immunity (vCMI) following neonatal woodchuck hepatitis virus (WHV) infection. Fifteen neonates were inoculated with the W8 strain of WHV. In 11, infection was resolved, and 4 became chronic carriers. Nineteen neonates were inoculated with the W7 strain and all became chronic carriers. Seven age-matched uninfected woodchucks served as controls. Virologic and vCMI profiles among the W8 and W7 infections were compared and related to the outcome of infection. Resolving woodchucks had robust, acute-phase vCMI to WHV antigens (core, surface, and x) and to several nonoverlapping core peptides. The acute-phase vCMI was associated temporally with the clearance of viral DNA and of surface antigen from serum at 14 to 22 weeks postinfection. In contrast, in approximately half of the W8 and W7 infections that progressed to chronicity, no significant acute-phase vCMI was detected. In the remaining carriers, acute-phase vCMI was observed, but it was less frequent and incomplete compared to that of resolved woodchucks. Serum viral load developed less rapidly in those carriers that had evidence of acute-phase vCMI, but it was still increased compared to that of resolving woodchucks. Thus, vigorous and multispecific acute-phase vCMI was associated with resolution of neonatal WHV infection. Absent or incomplete acute-phase vCMI was associated with the progression to chronic infection. By analogy, these results suggest that the onset of chronic hepatitis B virus (HBV) infection in humans may be associated with deficiencies in the primary T-cell response to acute HBV infection.
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Stark, Lauren E., Patricia LiWang i Michael E. Colvin. "Determining Factors that Influence vCCI Loop Interactions in vCCI-Chemokine Binding through MD Simulation". Biophysical Journal 118, nr 3 (luty 2020): 507a. http://dx.doi.org/10.1016/j.bpj.2019.11.2792.
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Corredor Parra, Lina Rocio, i Gloria Mabel Carrillo González. "Validez y confiabilidad del instrumento de calidad de vida de Betty Ferrell en español, para personas con enfermedad crónica". Investigación en Enfermería: Imagen y Desarrollo 18, nr 1 (7.12.2015): 129. http://dx.doi.org/10.11144/javeriana.ie18-1.vcic.
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<p>Los instrumentos utilizados para evaluar la calidad de vida deben suministrar información real, segura y adecuada. Por ello deben seguir procesos psicométricos de validez y confiabilidad que permitan su uso en el contexto nacional y latinoamericano y evidenciar que miden cuanto pretenden medir y con un alto grado de precisión. <em>Objetivo</em>: Determinar la validez y confiabilidad del instrumento calidad de vida de Betty Ferrell, para personas con enfermedad crónica, en Colombia. <em>Método</em>: Estudio<br />de abordaje cuantitativo descriptivo de corte transversal metodológico. Participaron 287 personas con enfermedad crónica no transmisible. Se realizó validez de contenido por medio del índice de concordancia de kappa y el índice de validez de contenido y se realiza validez de constructo, así como confiabilidad por consistencia interna mediante<br />el alfa de Cronbach. <em>Resultados</em>: Se determinó una validez de contenido adecuada con un índice de validez de contenido (IVC) de 0,9, e índice de kappa de 0,61. La consistencia interna por medio del alfa de Cronbach fue de 0,88. Respecto a la validez de constructo, al análisis factorial exploratorio solo 22 de los 41 ítems se explican por el factor subyacente a la dimensión planteada por el autor y se observa discrepancia<br />en las dimensiones de bienestar psicológico y bienestar social. <em>Conclusiones:</em> El instrumento de calidad de vida de Betty Ferrell para personas con enfermedad crónica es confiable, pues tiene un adecuado índice de validez de contenido para su uso en el contexto local. Se requiere seguir estudiando el constructo, probablemente con la<br />eliminación de ítems y análisis factorial confirmatorio.</p>
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Medellín Mendoza, Laura Nelly. "De la victoria de un candidato independiente a los desafíos en la eficacia del desempeño gubernamental: el caso de Nuevo León, México." Papel Político 23, nr 2 (8.04.2019): 1–16. http://dx.doi.org/10.11144/javeriana.papo23-2.vcid.
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Se analiza la victoria de un candidato independiente que ganó un gobierno subnacional excluyendo al sistema tradicional de partidos políticos. Como fue una experiencia inédita en México, se toman en cuenta las condiciones del sistema político caracterizado por la dominación de un partido hegemónico en donde su capacidad para minimizar la representación política fue la constante, hasta que gradualmente el proceso de liberalización política por la vía electoral pudo permitir el pluralismo político. En la reforma electoral del 2014 se contó con la posibilidad de tener candidaturas independientes y el estado de Nuevo León, también incluyó la figura. Por tanto, en el análisis del primer gobierno independiente del estado de Nuevo León se toma en cuenta la variable antecedente de cómo fue la ruta electoral ganadora que a través fundamentalmente de una plataforma de redes sociales y no por la vía convencional de hacer campañas electorales, se logró una victoria sin precedentes en la historia local y nacional. Posteriormente centrándose sólo en dos variables para medir eficacia política gubernamental se muestra evidencia empírica para analizar los resultados en materia de corrupción y seguridad pública. Posteriormente se incluye el contexto de la salida de la gubernatura y las conclusiones en primer balance de gobierno.
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Li, Guangming. "Which method is optimal for estimating variance components and their variability in generalizability theory? evidence form a set of unified rules for bootstrap method". PLOS ONE 18, nr 7 (14.07.2023): e0288069. http://dx.doi.org/10.1371/journal.pone.0288069.
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Objective The purpose of this study is to compare the performance of the four estimation methods (traditional method, jackknife method, bootstrap method, and MCMC method), find the optimal one, and make a set of unified rules for Bootstrap. Methods Based on four types of simulated data (normal, dichotomous, polytomous, and skewed data), this study estimates and compares the estimated variance components and their variability of the four estimation methods when using a p×i design in generalizability theory. The estimated variance components are vc.p, vc.i and vc.pi and the variability of estimated variance components are their estimated standard errors (SE(vc.p), SE(vc.i) and SE(vc.pi)) and confidence intervals (CI(vc.p), CI(vc.i) and CI(vc.pi)). Results For the normal data, all the four methods can accurately estimate the variance components and their variability. For the dichotomous data, the |RPB| of SE (vc.i) of traditional method is 128.5714, the |RPB| of SE (vc.i), SE (vc.pi) and CI (vc.i) of jackknife method are 42.8571, 43.6893 and 40.5000, which are larger than 25 and not accurate. For the polytomous data, the |RPB| of SE (vc.i) and CI (vc.i) of MCMC method are 59.6612 and 45.2500, which are larger than 25 and not accurate. For the skewed data, the |RPB| of SE (vc.p), SE (vc.i) and SE (vc. pi) of traditional method and MCMC method are over 25, which are not accurate. Only the bootstrap method can estimate variance components and their variability accurately across different data distribution. Nonetheless, the divide-and-conquer strategy must be used when adopting the bootstrap method. Conclusions The bootstrap method is optimal among the four methods and shows the cross-distribution superiority over the other three methods. However, a set of unified rules for the divide-and-conquer strategy need to be recommended for the bootstrap method, which is optimal when boot-p for p (person), boot-pi for i (item), and boot-i for pi (person × item).
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Mariacher, Anton. "Der VCI antwortet". Nachrichten aus Chemie, Technik und Laboratorium 33, nr 11 (listopad 1985): 981. http://dx.doi.org/10.1002/nadc.19850331116.
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Rivkin, Lawrence S. "The veterinary computerized information system (VCIS)". Journal of Equine Veterinary Science 5, nr 1 (styczeń 1985): 52–54. http://dx.doi.org/10.1016/s0737-0806(85)80088-5.
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Zhou, Xinhua, Guozhen Cui, Hisa Hui Ling Tseng, Simon Ming-Yuen Lee, George Pak Heng Leung, Shun Wan Chan, Yiu Wa Kwan i Maggie Pui Man Hoi. "Vascular Contributions to Cognitive Impairment and Treatments with Traditional Chinese Medicine". Evidence-Based Complementary and Alternative Medicine 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/9627258.
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The prevalence of cognitive impairment and dementia caused by cerebrovascular disease is likely to increase with the global aging population. Vascular contributions to cognitive impairment and dementia (VCID) is a wide spectrum term used to include a diverse heterogeneous group of cognitive syndromes with vascular factors regardless of the cause of pathogenesis. VCID ranges from mild cognitive impairment to full-blown dementia with vascular dementia (VaD) as the most severe stage. It is further complexed by the coexistence of other forms of dementia such as Alzheimer’s disease (AD). Recent researches in the functions of the neurovascular unit (NVU) suggest that dysfunction of the NVU might be the cause of primary vascular events in the brain that leads to further neurodegeneration. In this review, we have briefly summarized various forms of VCID. There is currently no standard therapy for VCID or dementia. Given the fact that Traditional Chinese Medicine (TCM) has gained popularity worldwide, we also reviewed recent scientific and clinical findings on various antidementia TCM for the treatment of VCID, including Salvia miltiorrhiza, Huperzia serrata, Ligusticum chuanxiong, Ginkgo biloba, Panax ginseng, and also TCM formula Sailuotong capsule (SLT) and Fufangdanshen tablets (FFDS).
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Arenas, Rosalinda Sanchez, Michael A. Gregory i Leticia Manuel-Apolinar. "SOLUBLE INTERCELLULAR ADHESION MOLECULE (SICAM-1) AS A BIOMARKER OF VASCULAR COGNITIVE IMPAIRMENT IN OLDER ADULTS". Innovation in Aging 3, Supplement_1 (listopad 2019): S256—S257. http://dx.doi.org/10.1093/geroni/igz038.959.
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Abstract Background: Endothelial dysfunction and subsequent inflammation contribute to the development of vascular cognitive impairment (VCI). Soluble intercellular adhesion molecule-1 (sICAM-1) is upregulated in endothelial dysfunction and promotes an inflammatory response; however, the relationship between sICAM-1 and VCI remains equivocal. Objective: To determine whether sICAM-1 contributes to the prediction of VCI. Methods: Community-dwelling older adults (n=172) from the “Cohort of Obesity, Sarcopenia and Frailty of Older Mexican Adults” (COSFOMA) study were identified as VCI or controls using standard neuropsychological evaluations and neuroimaging. sICAM-1 was quantified using ELISA, and multivariate logistic regression determined the association between sICAM-1 and VCI. Results: 31 VCI cases were identified. sICAM-1 was higher in VCI [VCI: 450.7 (241.6) ng/ml vs. Control: 296.9 (140.9) ng/ml]. sICAM-1 concentrations above the 90th percentile (464.1 ng/mL) was associated with VCI group membership in all models [OR = 6.9 (95% CI: 1.1- 42.2)]. The final saturated model explained 64% of the variance in VCI group membership. Conclusion: High concentrations of sICAM-1 are independently associated with VCI group membership. Efforts to further characterize the relationship between indices of endothelial dysfunction and pathological changes to the aging brain should be further pursued.
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Gregory, Michael A., Leticia Manuel-Apolinar, Sergio Sánchez-Garcia, Antonio R. Villa Romero, Jaime de Jesús Iuit Rivera, Lourdes Basurto Acevedo, Israel Grijalva-Otero i in. "Soluble Intercellular Adhesion Molecule-1 (sICAM-1) as a Biomarker of Vascular Cognitive Impairment in Older Adults". Dementia and Geriatric Cognitive Disorders 47, nr 4-6 (2019): 243–53. http://dx.doi.org/10.1159/000500068.
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Background: Endothelial dysfunction and subsequent inflammation contribute to the development of vascular cognitive impairment (VCI). Soluble intercellular adhesion molecule-1 (sICAM-1) is upregulated in endothelial dysfunction and promotes an inflammatory response; however, the relationship between sICAM-1 and VCI remains equivocal. Objective: To determine whether sICAM-1 contributes to the prediction of VCI. Methods: Community-dwelling older adults (n = 172) from the “Cohort of Obesity, Sarcopenia and Frailty of Older Mexican Adults” (COSFOMA) study were identified as VCI or controls using standard neuropsychological evaluations and neuroimaging. sICAM-1 was quantified using ELISA, and multivariate logistic regression determined the association between sICAM-1 and VCI. Results: A total of 31 VCI cases were identified. sICAM-1 was higher in VCI (VCI: 450.7 [241.6] ng/mL vs. controls: 296.9 [140.9] ng/mL). sICAM-1 concentrations above the 90th percentile (464.1 ng/mL) were associated with VCI group membership in all models (OR: 6.9, 95% CI: 1.1–42.2). The final saturated model explained 64% of the variance in VCI group membership. Conclusion: High concentrations of sICAM-1 are independently associated with VCI group membership. Efforts to further characterize the relationship between indices of endothelial dysfunction and pathological changes to the aging brain should be further pursued.
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Trout, Amanda L., Ibolya Rutkai, Ifechukwude J. Biose i Gregory J. Bix. "Review of Alterations in Perlecan-Associated Vascular Risk Factors in Dementia". International Journal of Molecular Sciences 21, nr 2 (20.01.2020): 679. http://dx.doi.org/10.3390/ijms21020679.
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Perlecan is a heparan sulfate proteoglycan protein in the extracellular matrix that structurally and biochemically supports the cerebrovasculature by dynamically responding to changes in cerebral blood flow. These changes in perlecan expression seem to be contradictory, ranging from neuroprotective and angiogenic to thrombotic and linked to lipid retention. This review investigates perlecan’s influence on risk factors such as diabetes, hypertension, and amyloid that effect Vascular contributions to Cognitive Impairment and Dementia (VCID). VCID, a comorbidity with diverse etiology in sporadic Alzheimer’s disease (AD), is thought to be a major factor that drives the overall clinical burden of dementia. Accordingly, changes in perlecan expression and distribution in response to VCID appears to be injury, risk factor, location, sex, age, and perlecan domain dependent. While great effort has been made to understand the role of perlecan in VCID, additional studies are needed to increase our understanding of perlecan’s role in health and in cerebrovascular disease.
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Wang, Dong, Chenxi Wang, Changqing Fang, Xing Zhou, Mengyuan Pu i Yingwei Huang. "Protective behavior of volatile corrosion inhibitor on atmospheric corrosion process of carbon steel under thin electrolyte liquid film of chloride solutions". Materials Express 10, nr 9 (30.09.2020): 1435–43. http://dx.doi.org/10.1166/mex.2020.1778.
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The corrosion process of carbon steel and corrosion resistance behavior of volatile corrosion inhibitor (VCI) under thin electrolyte liquid film containing chloride was investigated by electrochemical measurements and surface characterization. Results indicated that composite VCI was composed of sodium molybdate and sodium benzoate, and exhibited higher corrosion resistance in 3.5% NaCl solution compared with absence of VCI. The corrosion current density obviously decreased with presence of VCI, and the synergies between binary components increased the corrosion inhibiting rate on carbon steel to up to 90%. The corrosion current density of carbon steel increased with increased temperature after volatilization of VCI. A closed container was carried out to mimic atmospheric corrosion condition, and its vapor corrosion inhibition property was evaluated in this closed container. Results showed that the VCI acted as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of protective film. It was also observed that the variation of carbon steel surface with volatilization of VCI was assessed by atomic force microscope (AFM) and scanning electron microscope (SEM). The anodic process for carbon steel without VCI affected the corrosion rate due to accumulation of corrosion products, while the morphology of carbon steel was hardly changed with volatilization of VCI. The results showed that the VCI volatilized to the surface and form to protect film. VCI was automatically volatilized into gas, which protected steel from corrosion. This composite VCI can then be applied as a significant corrosion inhibition method.
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Alex Scott. "Cefic, VCI share pessimism". C&EN Global Enterprise 101, nr 25 (31.07.2023): 12. http://dx.doi.org/10.1021/cen-10125-buscon6.
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Zhan, Min, Linjuan Sun, Jianxun Liu, Zixiu Zeng, Wei Shen, Huimin Li, Ying Wang i in. "EGb in the Treatment for Patients with VCI: A Systematic Review and Meta-Analysis". Oxidative Medicine and Cellular Longevity 2021 (27.08.2021): 1–18. http://dx.doi.org/10.1155/2021/8787684.
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Background. Ginkgo biloba extract (EGb) is widely used to treat impairments in memory, cognition, activities of daily living, inflammation, edema, stroke, Alzheimer’s dementia, and aging. Aim. We aimed to evaluate the safety and efficacy of EGb in treating vascular cognitive impairment (VCI). Methods. The systematic review was performed using the latest guidelines. We searched for EGb-related trials up to March 1, 2021, in four Chinese databases, three English databases, and clinical trial registry platforms. Randomized controlled trials (RCTs) were included if the study enrolled participants with VCI. Two reviewers independently extracted the data and critically appraised the study quality. Heterogeneity was quantified with I 2 . Both sensitivity and subgroup analyses were used to identify the sources of heterogeneity. Publication bias was assessed with funnel plots. We used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to rate the evidence quality. Outcomes included assessments using the Activities of Daily Living (ADL), Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale (HDS), Barthel Index (BI), Functional Activity Questionnaire (FAQ), and adverse events. Results. In this study, a total of 2019 patients in 23 RCTs were included. EGb appeared to be more effective than control conditions as assessed by the results of cognitive function evaluation, including MMSE ( M D MMSE , EGb vs . blank = 3.04 , 95% CI: 0.10-5.98; M D MMSE , EGb vs . drugs for VCI = 2.70 , 95% CI: 1.39-4.01; M D MMSE , EGb + drugs for VCI vs . blank = 5.90 , 95% CI: 4.21-7.59; and M D MMSE , EGb + drugs for VCI vs . drugs for VCI = 3.14 , 95% CI: 2.14-4.15), MoCA ( M D MoCA , EGb vs . blank = 5.30 , 95% CI: 2.15-8.46; M D MoCA , EGb + drugs for VCI vs . blank = 2.66 , 95% CI: 1.82-3.50; and M D MoCA , EGb + drugs for VCI vs . drugs for VCI = 2.56 , 95% CI: 1.85-3.27), HDS ( M D HDS , EGb vs . blank = 6.50 ; 95% CI: 4.86-8.14; M D HDS , EGb + drugs for VCI vs . drugs for VCI = 3.60 , 95% CI: 2.50-4.70), ADL ( M D ADL , EGb vs . blank = 7.20 , 95% CI: 3.28-11.12; M D ADL , EGb + drugs for VCI vs . blank = 10.00 , 95% CI: 7.51-12.49; and M D ADL , EGb + drugs for VCI vs . drugs for VCI = 9.20 , 95% CI: 7.26-11.14), BI ( M D BI , EGb + drugs for VCI vs . drugs for VCI = 5.71 , 95% CI: 2.99-8.43; M D FAQ , EGb vs . drugs for VCI = − 1.43 , 95% CI: -2.78 to 0.08), and FAQ ( M D FAQ , EGb + drugs for VCI vs . drugs for VCI = − 2.17 , 95% CI: -4.13 to 0.21). Evidence of certainty ranged from medium certainty to very low certainty. Conclusion. This meta-analysis showed that EGb may be an effective and safe treatment in improving MMSE, MOCA, ADL, and BI for VCI patients within three months of diagnosis. However, given the quality of the included RCTs, more preregistered trials are needed that explicitly examine the efficacy of EGb. This systematic review has been registered on PROSPERO, with the registration number CRD42021232967.