Design of Dual-Mode Local Oscillators Using CMOS Technology for Motion Detection Sensors

Directory of Open Access Journals (Sweden)

Keum-Won Ha

2018-04-01

Full Text Available Recently, studies have been actively carried out to implement motion detecting sensors by applying radar techniques. Doppler radar or frequency-modulated continuous wave (FMCW radar are mainly used, but each type has drawbacks. In Doppler radar, no signal is detected when the movement is stopped. Also, FMCW radar cannot function when the detection object is near the sensor. Therefore, by implementing a single continuous wave (CW radar for operating in dual-mode, the disadvantages in each mode can be compensated for. In this paper, a dual mode local oscillator (LO is proposed that makes a CW radar operate as a Doppler or FMCW radar. To make the dual-mode LO, a method that controls the division ratio of the phase locked loop (PLL is used. To support both radar mode easily, the proposed LO is implemented by adding a frequency sweep generator (FSG block to a fractional-N PLL. The operation mode of the LO is determined by according to whether this block is operating or not. Since most radar sensors are used in conjunction with microcontroller units (MCUs, the proposed architecture is capable of dual-mode operation by changing only the input control code. In addition, all components such as VCO, LDO, and loop filter are integrated into the chip, so complexity and interface issues can be solved when implementing radar sensors. Thus, the proposed dual-mode LO is suitable as a radar sensor.

Towards model-based control of RCCI-CDF mode-switching in dual fuel engines

NARCIS (Netherlands)

Indrajuana, Armando; Bekdemir, C.; Feru, E.; Willems, F.P.T.

2018-01-01

The operation of a dual fuel combustion engine using combustion mode-switching offers the benefit of higher thermal efficiency compared to single-mode operation. For various fuel combinations, the engine research community has shown that running dual fuel engines in Reactivity Controlled Compression

Dual-mode ultraflow access networks: a hybrid solution for the access bottleneck

Science.gov (United States)

Kazovsky, Leonid G.; Shen, Thomas Shunrong; Dhaini, Ahmad R.; Yin, Shuang; De Leenheer, Marc; Detwiler, Benjamin A.

2013-12-01

Optical Flow Switching (OFS) is a promising solution for large Internet data transfers. In this paper, we introduce UltraFlow Access, a novel optical access network architecture that offers dual-mode service to its end-users: IP and OFS. With UltraFlow Access, we design and implement a new dual-mode control plane and a new dual-mode network stack to ensure efficient connection setup and reliable and optimal data transmission. We study the impact of the UltraFlow system's design on the network throughput. Our experimental results show that with an optimized system design, near optimal (around 10 Gb/s) OFS data throughput can be attained when the line rate is 10Gb/s.

A dual-mode driver IC with monolithic negative drive-voltage capability and digital current-mode controller for depletion-mode GaN HEMT

NARCIS (Netherlands)

Wen, Y.; Rose, M.; Fernandes, R.; van Otten, R.; Bergveld, H.J.; Trescases, O.

2017-01-01

This work presents a driver and controller integrated circuit (IC) for depletion-mode gallium nitride (GaN) high-electron-mobility transistors (HEMTs). The dual-mode driver can be configured for cascode-drive (CD) or HEMT-drive (HD) mode. In the CD mode, a cascode low-voltage DMOS is driven to

Analysis of dual-mode lasing characteristics in a 1310-nm optically injected quantum dot distributed feedback laser

Science.gov (United States)

Raghunathan, R.; Olinger, J.; Hurtado, A.; Grillot, F.; Kovanis, V.; Lester, L. F.

2015-03-01

Recent work has shown the Quantum Dot (QD) material system to be well-suited to support dual-mode lasing. In particular, optical injection from a master laser (ML) into the residual Fabry-Perot (FP) modes of a 1310 nm Quantum Dot Distributed Feedback (QD-DFB) laser has been recently demonstrated to offer a highly reliable platform for stable dual-mode lasing operation. External controls on the ML, such as operating temperature and bias current, can be used to precisely adjust the spacing between the two lasing modes. This tunability of modeseparation is very promising for a range of applications requiring the generation of microwave, millimeter wave and terahertz signals. Considering the versatility and utility of such a scheme, it is imperative to acquire a deeper understanding of the factors that influence the dual-mode lasing process, in order to optimize performance. Toward this end, this paper seeks to further our understanding of the optically-injected dual-mode lasing mechanism. For fixed values of optical power injected into each FP residual mode and wavelength detuning, the dual-mode lasing characteristics are analyzed with regard to important system parameters such as the position and the intensity of the injected residual mode (relative to the Bragg and the other residual FP modes of the device) for two similarly-fabricated QD-DFBs. Results indicate that for dual mode lasing spaced less than 5 nm apart, the relative intensity of the injected FP mode and intracavity noise levels are critical factors in determining dual mode lasing behavior. Insight into the dual-mode lasing characteristics could provide an important design guideline for the master and QD-DFB slave laser cavities.

Financial Management of Distance Learning in Dual-Mode Institutions

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Rumble, Greville

2012-01-01

Dual-mode universities operating in a tough economic environment need to be able to answer a range of questions concerning their use of different teaching modes accurately and with confidence. Only an activity-based costing approach will provide them with this tool. Cost studies of other distance learning projects may provide benchmarks against…

Incidence of catheter-related complications in patients with central venous or hemodialysis catheters: a health care claims database analysis.

Science.gov (United States)

Napalkov, Pavel; Felici, Diana M; Chu, Laura K; Jacobs, Joan R; Begelman, Susan M

2013-10-16

Central venous catheter (CVC) and hemodialysis (HD) catheter usage are associated with complications that occur during catheter insertion, dwell period, and removal. This study aims to identify and describe the incidence rates of catheter-related complications in a large patient population in a United States-based health care claims database after CVC or HD catheter placement. Patients in the i3 InVision DataMart® health care claims database with at least 1 CVC or HD catheter insertion claim were categorized into CVC or HD cohorts using diagnostic and procedural codes from the US Renal Data System, American College of Surgeons, and American Medical Association's Physician Performance Measures. Catheter-related complications were identified using published diagnostic and procedural codes. Incidence rates (IRs)/1000 catheter-days were calculated for complications including catheter-related bloodstream infections (CRBSIs), thrombosis, embolism, intracranial hemorrhage (ICH), major bleeding (MB), and mechanical catheter-related complications (MCRCs). Thirty percent of the CVC cohort and 54% of the HD cohort had catheter placements lasting <90 days. Catheter-related complications occurred most often during the first 90 days of catheter placement. IRs were highest for CRBSIs in both cohorts (4.0 [95% CI, 3.7-4.3] and 5.1 [95% CI, 4.7-5.6], respectively). Other IRs in CVC and HD cohorts, respectively, were thrombosis, 1.3 and 0.8; MCRCs, 0.6 and 0.7; embolism, 0.4 and 0.5; MB, 0.1 and 0.3; and ICH, 0.1 in both cohorts. Patients with cancer at baseline had significantly higher IRs for CRBSIs and thrombosis than non-cancer patients. CVC or HD catheter-related complications were most frequently seen in patients 16 years or younger. The risk of catheter-related complications is highest during the first 90 days of catheter placement in patients with CVCs and HD catheters and in younger patients (≤16 years of age) with HD catheters. Data provided in this study can be applied

[Application of second generation dual-source computed tomography dual-energy scan mode in detecting pancreatic adenocarcinoma].

Science.gov (United States)

Xue, Hua-dan; Liu, Wei; Sun, Hao; Wang, Xuan; Chen, Yu; Su, Bai-yan; Sun, Zhao-yong; Chen, Fang; Jin, Zheng-yu

2010-12-01

To analyze the clinical value of multiple sequences derived from dual-source computed tomography (DSCT) dual-energy scan mode in detecting pancreatic adenocarcinoma. Totally 23 patients with clinically or pathologically diagnosed pancreatic cancer were enrolled in this retrospective study. DSCT (Definition Flash) was used and dual-energy scan mode was used in their pancreatic parenchyma phase scan (100kVp/230mAs and Sn140kVp/178mAs) . Mono-energetic 60kev, mono-energetic 80kev, mono-energetic 100kev, mono-energetic 120kev, linear blend image, non-linear blend image, and iodine map were acquired. pancreatic parenchyma-tumor CT value difference, ratio of tumor to pancreatic parenchyma, and pancreatic parenchyma-tumor contrast to noise ratio were calculated. One-way ANOVA was used for the comparison of diagnostic values of the above eight different dual-energy derived sequences for pancreatic cancer. The pancreatic parenchyma-tumor CT value difference, ratio of tumor to pancreatic parenchyma, and pancreatic parenchyma-tumor contrast to noise ratio were significantly different among eight sequences (P<0.05) . Mono-energetic 60kev image showed the largest parenchyma-tumor CT value [ (77.53 ± 23.42) HU] , and iodine map showed the lowest tumor/parenchyma enhancement ratio (0.39?0.12) and the largest contrast to noise ratio (4.08 ± 1.46) . Multiple sequences can be derived from dual-energy scan mode with DSCT via multiple post-processing methods. Integration of these sequences may further improve the sensitivity of the multislice spiral CT in the diagnosis of pancreatic cancer.

Intracranial investigation of a patient with nodular heterotopia and hippocampal sclerosis: dealing with a dual pathology.

Science.gov (United States)

Ladino, Lady Diana; Dash, Chelsea; Wu, Adam; Tellez-Zenteno, Jose Francisco

2017-06-01

The pre-operative assessment and surgical management of patients with dual pathology is challenging. We describe a patient with drug-resistant focal epilepsy with hippocampal sclerosis and extensive periventricular nodular heterotopia in the same hemisphere. The semiology, scalp EEG, and imaging were divergent, but the presence of focal interictal and ictal epileptic discharges of the putative ictal onset zone resulted in successful localization of the epileptogenic zone. A less aggressive resection was performed based on intracranial EEG recording. The patient has been seizure-free for three years since resection. Electroclinical hypotheses and challenges in defining the epileptogenic network are discussed.

A dual-mode proximity sensor with integrated capacitive and temperature sensing units

International Nuclear Information System (INIS)

Qiu, Shihua; Huang, Ying; He, Xiaoyue; Sun, Zhiguang; Liu, Ping; Liu, Caixia

2015-01-01

The proximity sensor is one of the most important devices in the field of robot application. It can accurately provide the proximity information to assistant robots to interact with human beings and the external environment safely. In this paper, we have proposed and demonstrated a dual-mode proximity sensor composed of capacitive and resistive sensing units. We defined the capacitive type proximity sensor perceiving the proximity information as C-mode and the resistive type proximity sensor detecting as R-mode. Graphene nanoplatelets (GNPs) were chosen as the R-mode sensing material because of its high performance. The dual-mode proximity sensor presents the following features: (1) the sensing distance of the dual-mode proximity sensor has been enlarged compared with the single capacitive proximity sensor in the same geometrical pattern; (2) experiments have verified that the proposed sensor can sense the proximity information of different materials; (3) the proximity sensing capability of the sensor has been improved by two modes perceive collaboratively, for a plastic block at a temperature of 60 °C: the R-mode will perceive the proximity information when the distance d between the sensor and object is 6.0–17.0 mm and the C-mode will do that when their interval is 0–2.0 mm; additionally two modes will work together when the distance is 2.0–6.0 mm. These features indicate our transducer is very valuable in skin-like sensing applications. (paper)

Catheter versus non-catheter angiography in isolated third nerve palsy

International Nuclear Information System (INIS)

Lee, A.G.

2007-01-01

To discuss the controversies surrounding the indications for catheter angiography versus non-catheter and less invasive angiography techniques (e.g. magnetic resonance angiography (MRA) and computerized tomography angiography (CTA)) in the evaluation of patients with a third nerve palsy. Clinical opinion-perspective and literature review. The patient with an isolated third nerve palsy might have a vasculopathic (and typically benign, self limited course) etiology or a life threatening intracranial posterior communicating artery aneurysm. Although it is clear that non-isolated third nerve palsies require imaging directed at the topographical localization of the clinical findings, the evaluation of the neurologically isolated third nerve palsy remains controversial. The completeness of the external (i.e. somatic) motor dysfunction and the presence or absence of internal (i.e. pupillary) dysfunction are generally used to guide the choice of initial neuroimaging. Advances in MRA and CTA technology have reduced but not eliminated our dependence upon catheter angiography in this setting. A properly performed and interpreted MRA or CTA probably will be able to detect greater than 95 % of aneurysms producing a third nerve palsy. The issues surrounding the use of catheter angiography in third nerve palsy are reviewed. If the clinician is highly confident in the capability, availability, and reliability of the neuroradiologist and of their institutional experience and quality of less invasive non-catheter MRA and CTA and if the risk of aneurysm is low or if the risk of angiography is high (e.g. elderly, renal failure, iodinated contrast allergy, risk of stroke) then MRI and MRA (or CTA) may be a reasonable alternative to catheter angiography. Patients with a moderate or uncertain risk of aneurysm and a lower risk for catheter angiography or if there is a low confidence in the quality or the interpretation of the institutional MRA (or CTA) may still require catheter

Dual-Pump CARS Measurements in the University of Virginia's Dual-Mode Scramjet: Configuration "C"

Science.gov (United States)

Cutler, Andrew D.; Magnotti, Gaetano; Cantu, Luca; Gallo, Emanuela; Danehy, Paul M.; Rockwell, Robert; Goyne, Christopher; McDaniel, James

2013-01-01

Measurements have been conducted at the University of Virginia Supersonic Combustion Facility in configuration C of the dual-mode scramjet. This is a continuation of previously published works on configuration A. The scramjet is hydrogen fueled and operated at two equivalence ratios, one representative of the scram mode and the other of the ram mode. Dual-pump CARS was used to acquire the mole fractions of the major species as well as the rotational and vibrational temperatures of N2. Developments in methods and uncertainties in fitting CARS spectra for vibrational temperature are discussed. Mean quantities and the standard deviation of the turbulent fluctuations at multiple planes in the flow path are presented. In the scram case the combustion of fuel is completed before the end of the measurement domain, while for the ram case the measurement domain extends into the region where the flow is accelerating and combustion is almost completed. Higher vibrational than rotational temperature is observed in those parts of the hot combustion plume where there is substantial H2 (and hence chemical reaction) present.

Dual-gated cardiac PET-clinical feasibility study

Energy Technology Data Exchange (ETDEWEB)

Teraes, Mika; Kokki, Tommi; Noponen, Tommi; Hoppela, Erika; Sipilae, Hannu T.; Knuuti, Juhani [Turku PET Centre, PO BOX 52, Turku (Finland); Durand-Schaefer, Nicolas [General Electric Medical Systems, Buc (France); Pietilae, Mikko [Turku University Hospital, Department of Internal Medicine, Turku (Finland); Kiss, Jan [Turku University Hospital, Department of Surgery, Turku (Finland)

2010-03-15

Both respiratory and cardiac motions reduce image quality in myocardial imaging. For accurate imaging of small structures such as vulnerable coronary plaques, simultaneous cardiac and respiratory gating is warranted. This study tests the feasibility of a recently developed robust method for cardiac-respiratory gating. List-mode data with triggers from respiratory and cardiac cycles are rearranged into dual-gated segments and reconstructed with standard algorithms of a commercial PET/CT scanner. Cardiac gates were defined as three fixed phases and one variable diastolic phase. Chest motion was measured with a respiratory gating device and post-processed to determine gates. Preservation of quantification in dual-gated images was tested with an IEC whole-body phantom. Minipig and human studies were performed to evaluate the feasibility of the method. In minipig studies, a coronary catheter with radioactive tip was guided in coronary artery for in vivo and ex vivo acquisitions. Dual gating in humans with suspected cardiac disorders was performed using 18-F-FDG as a tracer. The method was found feasible for in vivo imaging and the radioactive catheter tip was better resolved in gated images. In human studies, the dual gating was found feasible and easy for clinical routine. Maximal movement of myocardial surface in cranio-caudal direction was over 20 mm. The shape of myocardium was clearly different between the gates and papillary muscles become more visible in diastolic images. The first clinical experiences using robust cardiac-respiratory dual gating are encouraging. Further testing in larger clinical populations using tracers designed especially for plaque imaging is warranted. (orig.)

Dual-gated cardiac PET-clinical feasibility study

International Nuclear Information System (INIS)

Teraes, Mika; Kokki, Tommi; Noponen, Tommi; Hoppela, Erika; Sipilae, Hannu T.; Knuuti, Juhani; Durand-Schaefer, Nicolas; Pietilae, Mikko; Kiss, Jan

2010-01-01

Both respiratory and cardiac motions reduce image quality in myocardial imaging. For accurate imaging of small structures such as vulnerable coronary plaques, simultaneous cardiac and respiratory gating is warranted. This study tests the feasibility of a recently developed robust method for cardiac-respiratory gating. List-mode data with triggers from respiratory and cardiac cycles are rearranged into dual-gated segments and reconstructed with standard algorithms of a commercial PET/CT scanner. Cardiac gates were defined as three fixed phases and one variable diastolic phase. Chest motion was measured with a respiratory gating device and post-processed to determine gates. Preservation of quantification in dual-gated images was tested with an IEC whole-body phantom. Minipig and human studies were performed to evaluate the feasibility of the method. In minipig studies, a coronary catheter with radioactive tip was guided in coronary artery for in vivo and ex vivo acquisitions. Dual gating in humans with suspected cardiac disorders was performed using 18-F-FDG as a tracer. The method was found feasible for in vivo imaging and the radioactive catheter tip was better resolved in gated images. In human studies, the dual gating was found feasible and easy for clinical routine. Maximal movement of myocardial surface in cranio-caudal direction was over 20 mm. The shape of myocardium was clearly different between the gates and papillary muscles become more visible in diastolic images. The first clinical experiences using robust cardiac-respiratory dual gating are encouraging. Further testing in larger clinical populations using tracers designed especially for plaque imaging is warranted. (orig.)

Design of dual-mode optical fibres for the FTTH applications

Science.gov (United States)

Chen, Ming-Yang; Li, Yu-Rong; Zhang, Yin; Zhu, Yuan-Feng; Zhang, Yong-Kang; Zhou, Jun

2011-01-01

We present in this article a proposal and design for dual-mode optical fibres for fibre-to-the-home applications. High-order modes in the fibre can be effectively suppressed by the connection of the fibre with standard single-mode optical fibres at the two ends of the fibre. The alignment tolerance at the splicing process is presented. In particular, a low bending loss operation with low splice loss is demonstrated using the proposed technique.

Design of dual-mode optical fibres for the FTTH applications

International Nuclear Information System (INIS)

Chen, Ming-Yang; Li, Yu-Rong; Zhang, Yin; Zhu, Yuan-Feng; Zhang, Yong-Kang; Zhou, Jun

2011-01-01

We present in this article a proposal and design for dual-mode optical fibres for fibre-to-the-home applications. High-order modes in the fibre can be effectively suppressed by the connection of the fibre with standard single-mode optical fibres at the two ends of the fibre. The alignment tolerance at the splicing process is presented. In particular, a low bending loss operation with low splice loss is demonstrated using the proposed technique

Nanodiamond-Manganese dual mode MRI contrast agents for enhanced liver tumor detection.

Science.gov (United States)

Hou, Weixin; Toh, Tan Boon; Abdullah, Lissa Nurrul; Yvonne, Tay Wei Zheng; Lee, Kuan J; Guenther, Ilonka; Chow, Edward Kai-Hua

2017-04-01

Contrast agent-enhanced magnetic resonance (MR) imaging is critical for the diagnosis and monitoring of a number of diseases, including cancer. Certain clinical applications, including the detection of liver tumors, rely on both T1 and T2-weighted images even though contrast agent-enhanced MR imaging is not always reliable. Thus, there is a need for improved dual mode contrast agents with enhanced sensitivity. We report the development of a nanodiamond-manganese dual mode contrast agent that enhanced both T1 and T2-weighted MR imaging. Conjugation of manganese to nanodiamonds resulted in improved longitudinal and transverse relaxivity efficacy over unmodified MnCl 2 as well as clinical contrast agents. Following intravenous administration, nanodiamond-manganese complexes outperformed current clinical contrast agents in an orthotopic liver cancer mouse model while also reducing blood serum concentration of toxic free Mn 2+ ions. Thus, nanodiamond-manganese complexes may serve as more effective dual mode MRI contrast agent, particularly in cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of peripherally inserted central catheter (PICC) valve technology on catheter occlusion rates--the 'ELeCTRiC' study.

Science.gov (United States)

Johnston, Andrew J; Streater, Carmel T; Noorani, Remy; Crofts, Joanne L; Del Mundo, Aldwin B; Parker, Richard A

2012-01-01

Peripherally Inserted Central Catheters (PICCs) are increasingly being used to provide short to medium-term central venous access. The current study was designed to test the hypothesis that PICC valve technology does not influence PICC occlusion rates. Intensive care unit (ICU) patients who required a PICC were randomized to one of three types of dual lumen PICC (open ended non-valved, Groshong valve, PASV valve). PICC occlusions were recorded and managed with a protocol that used urokinase. A total of 102 patients were recruited to the study. The overall risk of occlusion per catheter was 35% (95% CI 26% to 44%). The overall rate of occlusion was 76 occlusions per 1000 catheter days (95% CI 61 to 95). Presence or type of valve did not significantly influence this rate (open-ended non-valved PICC 38% of catheters, 79 occlusions per 1000 catheter days; Groshong 38% of catheters, 60 occlusions per 1000 catheter days; PASV 27% of catheters, 99 occlusions per 1000 catheter days). The dose of urokinase required to treat PICC occlusions did not significantly differ between PICC types. Valved PICCs do not appear to influence PICC occlusion rates.

Dual comb generation from a mode-locked fiber laser with orthogonally polarized interlaced pulses.

Science.gov (United States)

Akosman, Ahmet E; Sander, Michelle Y

2017-08-07

Ultra-high precision dual-comb spectroscopy traditionally requires two mode-locked, fully stabilized lasers with complex feedback electronics. We present a novel mode-locked operation regime in a thulium-holmium co-doped fiber laser, a frequency-halved state with orthogonally polarized interlaced pulses, for dual comb generation from a single source. In a linear fiber laser cavity, an ultrafast pulse train composed of co-generated, equal intensity and orthogonally polarized consecutive pulses at half of the fundamental repetition rate is demonstrated based on vector solitons. Upon optical interference of the orthogonally polarized pulse trains, two stable microwave RF beat combs are formed, effectively down-converting the optical properties into the microwave regime. These co-generated, dual polarization interlaced pulse trains, from one all-fiber laser configuration with common mode suppression, thus provide an attractive compact source for dual-comb spectroscopy, optical metrology and polarization entanglement measurements.

A flexible dual-mode proximity sensor based on cooperative sensing for robot skin applications

Science.gov (United States)

Huang, Ying; Cai, Xia; Kan, Wenqing; Qiu, Shihua; Guo, Xiaohui; Liu, Caixia; Liu, Ping

2017-08-01

A flexible dual-mode proximity sensor has been designed and implemented, which is capable of combining capacitive-resistive detection in this paper. The capacitive type proximity sensor detecting is defined as mode-C, and the resistive type proximity sensor detecting is defined as mode-R. The characteristics of the proximity sensor are as follows: (1) the theoretical mode is developed which indicates that this proximity sensor can reflect proximity information accurately; (2) both sensing modes are vertically integrated into a sandwich-like chip with an 8 mm × 12 mm unit area. The thickness of a mode-R sensing material (graphene nanoplatelets) and mode-C dielectric (the mixture of carbon black and silicone rubber) is 1 mm and 2.5 mm, respectively; (3) for mode-R, the linearity of temperature-resistance curve can achieve 0.998 in the temperature range from 25°C to 65°C. And for mode-C, various materials can be successfully detected with fast response and high reversibility. Meanwhile, the study compensated the influence of object temperature to ensure mode-C properly works. A cooperative sensing test shows that R-C dual modes sense effectively which can enlarge the sensing distance compared with the single mode proximity sensor. The fabrication of this sensor is convenient, and the integrity of a flexible sandwich-like structure based on dual modes is beneficial to form arrays, which is suitable to be used in skin-like sensing applications.

Detecting Intracranial Hemorrhage Using Automatic Tube Current Modulation With Advanced Modeled Iterative Reconstruction in Unenhanced Head Single- and Dual-Energy Dual-Source CT.

Science.gov (United States)

Scholtz, Jan-Erik; Wichmann, Julian L; Bennett, Dennis W; Leithner, Doris; Bauer, Ralf W; Vogl, Thomas J; Bodelle, Boris

2017-05-01

The purpose of our study was to determine diagnostic accuracy, image quality, and radiation dose of low-dose single- and dual-energy unenhanced third-generation dual-source head CT for detection of intracranial hemorrhage (ICH). A total of 123 patients with suspected ICH were examined using a dual-source 192-MDCT scanner. Standard-dose 120-kVp single-energy CT (SECT; n = 36) and 80-kVp and 150-kVp dual-energy CT (DECT; n = 30) images were compared with low-dose SECT (n = 32) and DECT (n = 25) images obtained using automated tube current modulation (ATCM). Advanced modeled iterative reconstruction (ADMIRE) was used for all protocols. Detection of ICH was performed by three readers who were blinded to the image acquisition parameters of each image series. Image quality was assessed both quantitatively and qualitatively. Interobserver agreement was calculated using the Fleiss kappa. Radiation dose was measured as dose-length product (DLP). Detection of ICH was excellent (sensitivity, 94.9-100%; specificity, 94.7-100%) in all protocols (p = 1.00) with perfect interobserver agreement (0.83-0.96). Qualitative ratings showed significantly better ratings for both standard-dose protocols regarding gray matter-to-white matter contrast (p ≤ 0.014), whereas highest gray matter-to-white matter contrast-to-noise ratio was observed with low-dose DECT images (p ≥ 0.057). The lowest posterior fossa artifact index was measured for standard-dose DECT, which showed significantly lower values compared with low-dose protocols (p ≤ 0.034). Delineation of ventricular margins and sharpness of subarachnoidal spaces were rated excellent in all protocols (p ≥ 0.096). Low-dose techniques lowered radiation dose by 26% for SECT images (DLP, 575.0 ± 72.3 mGy · cm vs 771.5 ± 146.8 mGy · cm; p dual-source CT while allowing significant radiation dose reduction.

Intracranial Atherosclerotic Disease

Directory of Open Access Journals (Sweden)

Maria Khan

2011-01-01

Full Text Available Intracranial atherosclerotic disease (ICAD is the most common proximate mechanism of ischemic stroke worldwide. Approximately half of those affected are Asians. For diagnosis of ICAD, intra-arterial angiography is the gold standard to identify extent of stenosis. However, noninvasive techniques including transcranial ultrasound and MRA are now emerging as reliable modalities to exclude moderate to severe (50%–99% stenosis. Little is known about measures for primary prevention of the disease. In terms of secondary prevention of stroke due to intracranial atherosclerotic stenosis, aspirin continues to be the preferred antiplatelet agent although clopidogrel along with aspirin has shown promise in the acute phase. Among Asians, cilostazol has shown a favorable effect on symptomatic stenosis and is of benefit in terms of fewer bleeds. Moreover, aggressive risk factor management alone and in combination with dual antiplatelets been shown to be most effective in this group of patients. Interventional trials on intracranial atherosclerotic stenosis have so far only been carried out among Caucasians and have not yielded consistent results. Since the Asian population is known to be preferentially effected, focused trials need to be performed to establish treatment modalities that are most effective in this population.

An overmoded relativistic backward wave oscillator with efficient dual-mode operation

International Nuclear Information System (INIS)

Xiao, Renzhen; Li, Jiawei; Bai, Xianchen; Song, Zhimin; Teng, Yan; Ye, Hu; Li, Xiaoze; Sun, Jun; Chen, Changhua; Zhang, Xiaowei

2014-01-01

A dual-mode operation mechanism in an overmoded relativistic backward wave oscillator is presented. The electron beam interacts with the −1st space harmonic of TM 01 mode synchronously in the slow wave structure. Then the backward propagating TM 01 mode is converted to the forward propagating TM 02 mode. As the phase velocity of the volume harmonic of TM 02 mode is about twice that of the surface harmonic of TM 01 mode, the TM 02 mode also plays an important role in the high-power microwave generation. Particle-in-cell simulation shows that an efficiency of 48% and a significant improvement of the power capacity have been obtained

Tunable and stable single-longitudinal-mode dual-wavelength erbium fiber laser with 1.3 nm mode spacing output

International Nuclear Information System (INIS)

Yeh, C H; Shih, F Y; Wang, C H; Chow, C W; Chi, S

2008-01-01

In this investigation, we propose and investigate a stable and tunable dual-wavelength erbium-doped fiber (EDF) ring laser with self-injected Fabry-Perot laser diode (FP-LD) scheme. By using an FP-LD incorporated with a tunable bandpass filter (TBF) within the gain cavity, the fiber laser can lase at two single-longitudinal-mode (SLM) wavelengths simultaneously due to the self-injected operation. The proposed dual-wavelength laser has a good performance of the output power and optical side-mode suppression ratio (SMSR). The laser also shows a wide tuning range from 1523.08 to 1562.26 nm. Besides, the output stabilities of the fiber laser are also discussed

Development and Use of the Dual-Mode Plasma Torch

International Nuclear Information System (INIS)

Womack, R.; Shuey, M.

2002-01-01

After several years of development, a commercially available high-temperature treatment system has been developed and installed that treats heterogeneous low-level radioactive waste. High temperature plasma processing, unique torch design and operating features make it feasible to achieve a volume reduced, permanent, high integrity waste form while eliminating the personnel exposure and costs associated with conventional sorting, characterizing and handling. Plasma technology can also be used to treat previous conditioned waste packages that no longer meet the current acceptance criteria for final disposal. Plasma treatment can result, in many cases, in a substantial volume reduction, which lowers the final disposal costs. This paper covers the recently patented dual mode plasma torch design(1), the lessons learned that fostered its development and the advantages it brings to radioactive waste processing. This paper also provides current full scale Plasma Arc Centrifugal Treatment (PACT) project status and how the dual mode torch is being used in the PACT system

Examining Policy Guidelines for Distance Education in Dual Mode ...

African Journals Online (AJOL)

The study reports a case of distance education policy in the Kwame Nkrumah University of Science and Technology (KNUST), a dual mode University in Ghana. The interview method was used to obtain information from 21 purposively selected key informants in the University. Policy documents that addressed Distance ...

Multiple Coaxial Catheter System for Reliable Access in Interventional Stroke Therapy

International Nuclear Information System (INIS)

Kulcsar, Zsolt; Yilmaz, Hasan; Bonvin, Christophe; Lovblad, Karl O.; Ruefenacht, Daniel A.

2010-01-01

In some patients with acute cerebral vessel occlusion, navigating mechanical thrombectomy systems is difficult due to tortuous anatomy of the aortic arch, carotid arteries, or vertebral arteries. Our purpose was to describe a multiple coaxial catheter system used for mechanical revascularization that helps navigation and manipulations in tortuous vessels. A triple or quadruple coaxial catheter system was built in 28 consecutive cases presenting with acute ischemic stroke. All cases were treated by mechanical thrombectomy with the Penumbra System. In cases of unsuccessful thrombo-aspiration, additional thrombolysis or angioplasty with stent placement was used for improving recanalization. The catheter system consisted of an outermost 8-Fr and an intermediate 6-Fr guiding catheter, containing the inner Penumbra reperfusion catheters. The largest, 4.1-Fr, reperfusion catheter was navigated over a Prowler Select Plus microcatheter. The catheter system provided access to reach the cerebral lesions and provided stability for the mechanically demanding manipulations of thromboaspiration and stent navigation in all cases. Apart from their mechanical role, the specific parts of the system could also provide access to different types of interventions, like carotid stenting through the 8-Fr guiding catheter and intracranial stenting and thrombolysis through the Prowler Select Plus microcatheter. In this series, there were no complications related to the catheter system. In conclusion, building up a triple or quadruple coaxial system proved to be safe and efficient in our experience for the mechanical thrombectomy treatment of acute ischemic stroke.

Design and analysis of a dual mode CMOS field programmable analog array

International Nuclear Information System (INIS)

Cheng Xiaoyan; Yang Haigang; Yin Tao; Wu Qisong; Zhang Hongfeng; Liu Fei

2014-01-01

This paper presents a novel field-programmable analog array (FPAA) architecture featuring a dual mode including discrete-time (DT) and continuous-time (CT) operation modes, along with a highly routable connection boxes (CBs) based interconnection lattice. The dual mode circuit for the FPAA is capable of achieving targeted optimal performance in different applications. The architecture utilizes routing switches in a CB not only for the signal interconnection purpose but also for control of the electrical charge transfer required in switched-capacitor circuits. This way, the performance of the circuit in either mode shall not be hampered with adding of programmability. The proposed FPAA is designed and implemented in a 0.18 μm standard CMOS process with a 3.3 V supply voltage. The result from post-layout simulation shows that a maximum bandwidth of 265 MHz through the interconnection network is achieved. The measured results from demonstrated examples show that the maximum signal bandwidth of up to 2 MHz in CT mode is obtained with the spurious free dynamic range of 54 dB, while the signal processing precision in DT mode reaches 96.4%. (semiconductor integrated circuits)

Dual fuel mode operation in diesel engines using renewable fuels: Rubber seed oil and coir-pith producer gas

Energy Technology Data Exchange (ETDEWEB)

Ramadhas, A.S.; Jayaraj, S.; Muraleedharan, C. [Department of Mechanical Engineering, National Institute of Technology Calicut, Calicut-673601 (India)

2008-09-15

Partial combustion of biomass in the gasifier generates producer gas that can be used as supplementary or sole fuel for internal combustion engines. Dual fuel mode operation using coir-pith derived producer gas and rubber seed oil as pilot fuel was analyzed for various producer gas-air flow ratios and at different load conditions. The engine is experimentally optimized with respect to maximum pilot fuel savings in the dual fuel mode operation. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. Specific energy consumption in the dual-fuel mode of operation with oil-coir-pith operation is found to be in the higher side at all load conditions. Exhaust emission was found to be higher in the case of dual fuel mode of operation as compared to neat diesel/oil operation. Engine performance characteristics are inferior in fully renewable fueled engine operation but it suitable for stationary engine application, particularly power generation. (author)

SPHERICAL COVERAGE DUAL MODE SENSOR FOR UAS SEPARATION ASSURANCE, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Proposed is a dual-mode sensor for use aboard unmanned aircraft for safe operation in the NAS that: 1. Incorporates high resolution Millimeter Wave radar with high...

Radio frequency ablation in the rabbit lung using wet electrodes: comparison of monopolar and dual bipolar electrode mode

International Nuclear Information System (INIS)

Jin, Gong Yong; Park, Sang Hee; Han, Young Min; Chung, Gyung Ho; Kwak, Hyo Sung; Jeon, Soo Bin; Lee, Yong Chul

2006-01-01

To compare the effect of radio frequency ablation (RFA) on the dimensions of radio frequency coagulation necrosis in a rabbit lung using a wet electrode in monopolar mode with that in dual electrode bipolar mode at different infusion rates (15 mm/hr versus 30 ml/hr) and saline concentrations (0.9% normal versus 5.8% hypertonic saline. Fifty ablation zones (one ablation zone in each rabbit) were produced in 50 rabbit using one or two 16-guage wet electrodes with a 1- cm active tip. The RFA system used in the monopolar and dual electrode wet bipolar RFA consisted of a 375-kHz generator (Elektrotom HiTT 106, Berchtold, Medizinelektronik, Germany). The power used was 30 watts and the exposure time was 5 minutes. The rabbits were assigned to one of five groups. Group A (n = 10) was infused with 0.9% NaCl used at a rate of 30 ml/hr in a monopolar mode. Groups B (n=10) and C (n=10) were infused with 0.9% NaCl at a rate of 15 and 30ml/hr, respectively in dual electrode bipolar mode; groups D (n=10) and E (n=10) were infused with 5.8% NaCl at a rate of 15 and 30 ml/hr, respectively in a dual electrode bipolar mode. The dimensions of the ablation zones in the gross specimens from the groups were compared using one-way analysis of variance by means of the Scheffe test (post-hoc testing). The mean largest diameter of the ablation zones was larger in dual electrode bipolar mode (30.9 ± 4.4 mm) than in monopolar mode (22.5 ± 3.5 mm). The mean smallest diameter of the ablation zones was larger in dual electrode bipolar mode (22.3 ± 2.5 mm) than in monopolar mode (19.5 ± 3.5 mm). There were significant differences in the largest and smallest dimension between the monopolar (group A ) ana dual electrode wet bipolar mode (groups B-E). In dual electrode bipolar mode, the mean largest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (34.2 ± 4.0 mm) than at 30 ml/hr (27.6 ± 0.0 mm), and the mean smallest diameter of the ablation zones was larger at an

Safety of low-dose aspirin in endovascular treatment for intracranial atherosclerotic stenosis.

Directory of Open Access Journals (Sweden)

Ning Ma

Full Text Available OBJECTIVES: To evaluate the safety of low-dose aspirin plus clopidogrel versus high-dose aspirin plus clopidogrel in prevention of vascular risk within 90 days of duration of dual antiplatelet therapy in patients treated with intracranial endovascular treatment. METHODS: From January 2012 to December 2013, this prospective and observational study enrolled 370 patients with symptomatic intracranial atherosclerotic stenosis of ≥70% with poor collateral undergoing intracranial endovascular treatment. Antiplatelet therapy consists of aspirin, at a low-dose of 100 mg or high-dose of 300 mg daily; clopidogrel, at a dose of 75 mg daily for 5 days before endovascular treatment. The dual antiplatelet therapy continued for 90 days after intervention. The study endpoints include acute thrombosis, subacute thrombosis, stroke or death within 90 days after intervention. RESULTS: Two hundred and seventy three patients received low-dose aspirin plus clopidogrel and 97 patients received high-dose aspirin plus clopidogrel before intracranial endovascular treatment. Within 90 days after intervention, there were 4 patients (1.5% with acute thrombosis, 5 patients (1.8% with subacute thrombosis, 17 patients (6.2% with stroke, and 2 death (0.7% in low-dose aspirin group, compared with no patient (0% with acute thrombosis, 2 patient (2.1% with subacute thrombosis, 6 patients (6.2% with stroke, and 2 death (2.1% in high-dose aspirin group, and there were no significant difference in all study endpoints between two groups. CONCLUSION: Low-dose aspirin plus clopidogrel is comparative in safety with high-dose aspirin plus clopidogrel within 90 days of duration of dual antiplatelet therapy in patients treated with intracranial endovascular treatment.

Tunable and switchable dual-wavelength passively mode-locked Bi-doped all-fiber ring laser based on nonlinear polarization rotation

International Nuclear Information System (INIS)

Luo, A-P; Luo, Z-C; Xu, W-C; Dvoyrin, V V; Mashinsky, V M; Dianov, E M

2011-01-01

We demonstrate a tunable and switchable dual-wavelength passively mode-locked Bi-doped all-fiber ring laser by using nonlinear polarization rotation (NPR) technique. Exploiting the spectral filtering effect caused by the combination of the polarizer and intracavity birefringence, the wavelength separation of dual-wavelength mode-locked pulses can be flexibly tuned between 2.38 and 20.45 nm. Taking the advantage of NPR-induced intensity-dependent loss to suppress the mode competition, the stable dual-wavelength pulses output is obtained at room temperature. Moreover, the dual-wavelength switchable operation is achieved by simply rotating the polarization controllers (PCs)

Design and optimisation of dual-mode heat pump systems using natural fluids

International Nuclear Information System (INIS)

Zhang Wenling; Klemeš, Jiří Jaromír; Kim, Jin-Kuk

2012-01-01

The paper introduces new multi-period modelling and design methodology for dual-mode heat pumps using natural fluids. First, a mathematical model is developed to capture thermodynamic and operating characteristics of dual-mode heat pump systems, subject to different ambient temperatures. The multi-period optimisation framework has been developed to reflect different ambient conditions and its influences on heat pump performance, as well as to determine a system capacity of heat pump which allows systematic economic trade-offs between supplementary heating (or cooling) and operating cost for heat pump. Case study considering three geographical locations with different heating and cooling demands is presented to illustrate the importance of using multi-period optimisation for the design of heat pump systems.

Carbon Nanodots as Dual-Mode Nanosensors for Selective Detection of Hydrogen Peroxide

Science.gov (United States)

Shen, Cheng-Long; Su, Li-Xia; Zang, Jin-Hao; Li, Xin-Jian; Lou, Qing; Shan, Chong-Xin

2017-07-01

Hydrogen peroxide (H2O2) is an important product of oxidase-based enzymatic reactions, such as glucose/glucose oxidase (GOD) reaction. Therefore, the probing of generated H2O2 for achieving the detection of various carbohydrates and their oxidases is very significative. Herein, we report one kind of dual-emission carbon nanodots (CDs) that can serve as novel dual-mode nanosensors with both fluorometric and colorimetric output for the selective detection of H2O2. The dual-model nanosensors are established only by the undecorated dual-emission CDs, where significant fluorometric and colorimetric changes are observed with the addition of different concentrations of H2O2 in the CD solution, which benefit to the achievement of the naked-eye detection for H2O2. The mechanism of the nanosensors can be attributed to the fact that the external chemical stimuli like hydroxyl radicals from H2O2 bring about the change of surface properties and the aggregation of CDs, which dominate the emission and absorption of CDs. The constructed dual-mode nanosensors exhibit good biocompatibility and high selectivity toward H2O2 with a linear detection range spanning from 0.05 to 0.5 M and allow the detection of H2O2 as low as 14 mM.

A dual-mode 6-9 GHz transmitter for OFDM-UWB

International Nuclear Information System (INIS)

Chen Yunfeng; Gao Ting; Li Wei; Li Ning; Ren Junyan

2011-01-01

This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/QLPF, an up-conversion mixer, a two-stage power driver amplifier and a broadband high-speed frequency divider with LO buffers for I/Q LO carrier generation. The measurement results show that the gain ripple of the transmitter is within ±1.5/±2.8 dB from 6 to 8.7/9 GHz. The output IP3 is about +13.2 dBm, the output 1dBCP is around +2.8 dBm, and the LO leakage/sideband rejection ratio is about -35/-38 dBc. The ESD protected chip is fabricated with a TSMC 0.13 μm RFCMOS process with a die size of 1.6 x 1.3 mm 2 and the core circuit consumes only 46 mA under a 1.2 V supply. (semiconductor integrated circuits)

A dual-mode 6-9 GHz transmitter for OFDM-UWB

Energy Technology Data Exchange (ETDEWEB)

Chen Yunfeng; Gao Ting; Li Wei; Li Ning; Ren Junyan, E-mail: jyren@fudan.edu.cn, E-mail: w-li@fudan.edu.cn [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

2011-05-15

This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/QLPF, an up-conversion mixer, a two-stage power driver amplifier and a broadband high-speed frequency divider with LO buffers for I/Q LO carrier generation. The measurement results show that the gain ripple of the transmitter is within {+-}1.5/{+-}2.8 dB from 6 to 8.7/9 GHz. The output IP3 is about +13.2 dBm, the output 1dBCP is around +2.8 dBm, and the LO leakage/sideband rejection ratio is about -35/-38 dBc. The ESD protected chip is fabricated with a TSMC 0.13 {mu}m RFCMOS process with a die size of 1.6 x 1.3 mm{sup 2} and the core circuit consumes only 46 mA under a 1.2 V supply. (semiconductor integrated circuits)

Modulating Brain Connectivity by Simultaneous Dual-Mode Stimulation over Bilateral Primary Motor Cortices in Subacute Stroke Patients

Directory of Open Access Journals (Sweden)

Jungsoo Lee

2018-01-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS or transcranial direct current stimulation (tDCS has been used for the modulation of stroke patients’ motor function. Recently, more challenging approaches have been studied. In this study, simultaneous stimulation using both rTMS and tDCS (dual-mode stimulation over bilateral primary motor cortices (M1s was investigated to compare its modulatory effects with single rTMS stimulation over the ipsilesional M1 in subacute stroke patients. Twenty-four patients participated; 12 participants were assigned to the dual-mode stimulation group while the other 12 participants were assigned to the rTMS-only group. We assessed each patient’s motor function using the Fugl-Meyer assessment score and acquired their resting-state fMRI data at two times: prior to stimulation and 2 months after stimulation. Twelve healthy subjects were also recruited as the control group. The interhemispheric connectivity of the contralesional M1, interhemispheric connectivity between bilateral hemispheres, and global efficiency of the motor network noticeably increased in the dual-mode stimulation group compared to the rTMS-only group. Contrary to the dual-mode stimulation group, there was no significant change in the rTMS-only group. These data suggested that simultaneous dual-mode stimulation contributed to the recovery of interhemispheric interaction than rTMS only in subacute stroke patients. This trial is registered with NCT03279640.

Cerebral microdialysis methodology--evaluation of 20 kDa and 100 kDa catheters.

Science.gov (United States)

Hutchinson, P J; O'Connell, M T; Nortje, J; Smith, P; Al-Rawi, P G; Gupta, A K; Menon, D K; Pickard, J D

2005-08-01

Microdialysis monitoring of cerebral metabolism is now performed in several neuro-intensive care units. Conventional microdialysis utilizes CMA70 catheters with 20 kDa molecular weight cut-off membranes enabling the measurement of small molecules such as glucose, lactate, pyruvate and glutamate. The CMA71 100 kDa molecular weight cut-off microdialysis catheter has recently been introduced to allow detection of larger molecules such as cytokines. The objective of this study was to perform in vitro and in vivo testing of the CMA71 microdialysis catheter, comparing its performance with the CMA70. In vitro comparison studies of three of each catheter using reference analyte solutions, demonstrated equivalent recovery for glucose, lactate, pyruvate and glutamate (range 94-97% for CMA70 and 88-103% for CMA71). In vivo comparison involved intracranial placement of paired CMA70 and CMA71 catheters (through the same cranial access device) in six patients with severe traumatic brain injury. Both catheters were perfused with CNS Perfusion Fluid without dextran at 0.3 microl min-1 with hourly sampling and bedside analysis on a CMA600 microdialysis analyser. The two catheters yielded equivalent results for glucose, lactate, pyruvate, glutamate and lactate/pyruvate ratio. CMA71 microdialysis catheters can, therefore, be used for routine clinical monitoring of extracellular substances, as well as for their intended research role of larger molecular weight protein sampling.

Bioinspired Flexible and Highly Responsive Dual-Mode Strain/Magnetism Composite Sensor.

Science.gov (United States)

Huang, Pei; Li, Yuan-Qing; Yu, Xiao-Guang; Zhu, Wei-Bin; Nie, Shu-Yan; Zhang, Hao; Liu, Jin-Rui; Hu, Ning; Fu, Shao-Yun

2018-04-04

The mimicry of human skin to detect both oncoming and physical-contacting object is of great importance in the fields of manufacturing, artificial robots and vehicles, etc. Herein, a novel bioinspired flexible and highly responsive dual-mode strain/magnetism composite sensor, which works via both contact and contactless modes, is first fabricated by incorporating Fe 3 O 4 /silicone system into a carbon fiber aerogel (CFA). The distance dependence of magnetic field endorses the CFA/Fe 3 O 4 /silicone composite possible for spatial sensing due to the introduction of Fe 3 O 4 magnetic nanoparticles. As a result, the as-prepared flexible sensor exhibits precise and real-time response not only to direct-contact compression as usual but also to contactless magnetic field in a wide frequency range from 0.1 to 10 Hz, achieving the maximum variance of 68% and 86% in relative electrical resistance, respectively. The contact and contactless sensing modes of the strain/magnetism sensor are clearly demonstrated by recording the speeds of bicycle riding and walking, respectively. Interestingly, this dual-mode composite sensor exhibits the capacity of identifying the contact and contactless state, which is the first report for flexible sensors. The current protocol is eco-friendly, facile, and thought-provoking for the fabrication of multifunctional sensors.

A Dual-Mode Large-Arrayed CMOS ISFET Sensor for Accurate and High-Throughput pH Sensing in Biomedical Diagnosis.

Science.gov (United States)

Huang, Xiwei; Yu, Hao; Liu, Xu; Jiang, Yu; Yan, Mei; Wu, Dongping

2015-09-01

The existing ISFET-based DNA sequencing detects hydrogen ions released during the polymerization of DNA strands on microbeads, which are scattered into microwell array above the ISFET sensor with unknown distribution. However, false pH detection happens at empty microwells due to crosstalk from neighboring microbeads. In this paper, a dual-mode CMOS ISFET sensor is proposed to have accurate pH detection toward DNA sequencing. Dual-mode sensing, optical and chemical modes, is realized by integrating a CMOS image sensor (CIS) with ISFET pH sensor, and is fabricated in a standard 0.18-μm CIS process. With accurate determination of microbead physical locations with CIS pixel by contact imaging, the dual-mode sensor can correlate local pH for one DNA slice at one location-determined microbead, which can result in improved pH detection accuracy. Moreover, toward a high-throughput DNA sequencing, a correlated-double-sampling readout that supports large array for both modes is deployed to reduce pixel-to-pixel nonuniformity such as threshold voltage mismatch. The proposed CMOS dual-mode sensor is experimentally examined to show a well correlated pH map and optical image for microbeads with a pH sensitivity of 26.2 mV/pH, a fixed pattern noise (FPN) reduction from 4% to 0.3%, and a readout speed of 1200 frames/s. A dual-mode CMOS ISFET sensor with suppressed FPN for accurate large-arrayed pH sensing is proposed and demonstrated with state-of-the-art measured results toward accurate and high-throughput DNA sequencing. The developed dual-mode CMOS ISFET sensor has great potential for future personal genome diagnostics with high accuracy and low cost.

Enhanced Two-Stage Hierarchical Control for a Dual Mode WECS-Based Microgrid

Directory of Open Access Journals (Sweden)

Rasool M. Imran

2018-05-01

Full Text Available Along with the great benefits of utilizing renewable energy (e.g., wind energy in the power system, there are also some issues, such as increasing the uncertainty and reducing the system inertia. Communication-based centralized control has started to play a significant role in reacting to the aforementioned issues, especially for relatively small systems, such as microgrids. In this context, in this paper, an enhanced communication-based hierarchical control for a dual mode wind energy conversion system-based microgrid is modeled and investigated. The primary stage utilized the P-V/Q-f droop method, which is the preferred droop method to be used in microgrids when the line impedance is mainly resistive. The secondary stage relied on an enhanced methodology for compensating the deviations of voltage and frequency and improving the performance of the microgrid during small and large signal disturbances. Moreover, as this microgrid operates in a dual mode, the mode transition cases from grid-tied mode to autonomous mode and vice versa have been addressed. Thereafter, an improved control scheme for the unplanned outage transition and a modified control scheme for the pre-synchronization and reconnection transition were proposed. Finally, the proposed work was evaluated by the simulation results in MATLAB environment.

Volatile organic compounds discrimination based on dual mode detection

Science.gov (United States)

Yu, Yuanyuan; Wu, Enxiu; Chen, Yan; Feng, Zhihong; Zheng, Shijun; Zhang, Hao; Pang, Wei; Liu, Jing; Zhang, Daihua

2018-06-01

We report on a volatile organic compound (VOC) sensor that can provide concentration-independent signals toward target gases. The device is based on a dual-mode detection mechanism that can simultaneously record the mechanical (resonant frequency, f r) and electrical (current, I) responses of the same gas adsorption event. The two independent signals form a unique I–f r trace for each target VOC as the concentration varies. The mechanical response (frequency shift, Δf r) resulting from mass load on the device is directly related to the amount of surface adsorptions, while the electrical response (current variation, ΔI) is associated with charge transfer across the sensing interface and changes in carrier mobility. The two responses resulting from independent physical processes reflect intrinsic physical properties of each target gas. The ΔI–Δf r trace combined with the concentration dependent frequency (or current) signals can therefore be used to achieve target both recognition and quantification. The dual-mode device is designed and fabricated using standard complementary metal oxide semiconductor (CMOS) compatible processes. It exhibits consistent and stable performance in our tests with six different VOCs including ethanol, methanol, acetone, formaldehyde, benzene and hexane.

Dual-mode plasmonic nanorod type antenna based on the concept of a trapped dipole.

Science.gov (United States)

Panaretos, Anastasios H; Werner, Douglas H

2015-04-06

In this paper we theoretically investigate the feasibility of creating a dual-mode plasmonic nanorod antenna. The proposed design methodology relies on adapting to optical wavelengths the principles of operation of trapped dipole antennas, which have been widely used in the low MHz frequency range. This type of antenna typically employs parallel LC circuits, also referred to as "traps", which are connected along the two arms of the dipole. By judiciously choosing the resonant frequency of these traps, as well as their position along the arms of the dipole, it is feasible to excite the λ/2 resonance of both the original dipole as well as the shorter section defined by the length of wire between the two traps. This effectively enables the dipole antenna to have a dual-mode of operation. Our analysis reveals that the implementation of this concept at the nanoscale requires that two cylindrical pockets (i.e. loading volumes) be introduced along the length of the nanoantenna, inside which plasmonic core-shell particles are embedded. By properly selecting the geometry and constitution of the core-shell particle as well as the constitution of the host material of the two loading volumes and their position along the nanorod, the equivalent effect of a resonant parallel LC circuit can be realized. This effectively enables a dual-mode operation of the nanorod antenna. The proposed methodology introduces a compact approach for the realization of dual-mode optical sensors while at the same time it clearly illustrates the inherent tuning capabilities that core-shell particles can offer in a practical framework.

Telemetric implantable pressure sensor for short- and long-term monitoring of intracranial pressure.

Science.gov (United States)

Frischholz, M; Sarmento, L; Wenzel, M; Aquilina, K; Edwards, R; Coakham, H B

2007-01-01

Patients with hydrocephalus, idiopathic intracranial hypertension and head injury frequently require monitoring of intracranial pressure (ICP) and may need repeated episodes of monitoring months or years apart. The gold standard for measurement of ICP remains the external ventricular catheter. This is a fluid-filled catheter transducer system that allows regular recalibration and correction of zero drift by its position relative to a fixed anatomical reference. It also allows drainage of cerebrospinal fluid (CSF), providing a means of lowering the ICP. Several catheter tip transducer systems are currently in clinical use, including using strain gauges or fiber-optical pressure sensing techniques. In these devices, zero drift and calibration cannot be checked in vivo. All the ICP monitoring devices in current clinical use require a physical connection between the brain and the external environment. This is a source of infection and limits the duration of monitoring. A number of telemetric monitoring devices, in which data is in some way transmitted transcutaneously, have been developed over the last twenty years, but significant technical problems have precluded their use in routine clinical practice. All current ICP monitors are temporary percutaneous implanted devices. Placement of these devices carries significant morbidity, particularly infection. Patients undergoing repeated monitoring require multiple surgical procedures. Apart from decreasing the risk of infection in patients with severe head injury, the clinical value of an accurate telemetric ICP monitoring system which maintains its reliability over a long period of implantation is high.

Dual-mode operation of 2D material-base hot electron transistors

KAUST Repository

Lan, Yann-Wen; Jr., Carlos M. Torres,; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R.; Lerner, Mitchell B.; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L.

2016-01-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Dual-mode operation of 2D material-base hot electron transistors

KAUST Repository

Lan, Yann-Wen

2016-09-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Dual-mode operation of 2D material-base hot electron transistors.

Science.gov (United States)

Lan, Yann-Wen; Torres, Carlos M; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R; Lerner, Mitchell B; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L

2016-09-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Sliding-Mode Control to Compensate PVT Variations in Dual Core Systems

NARCIS (Netherlands)

Pourshaghaghi, H.R.; Fatemi, S.H.; Pineda de Gyvez, J.

2012-01-01

In this paper, we present a novel robust sliding-mode controller for stabilizing supply voltage and clock frequency of dual core processors determined by dynamic voltage and frequency scaling (DVFS) methods in the presence of systematic and random variations. We show that maximum rejection for

Active power filter for harmonic compensation using a digital dual-mode-structure repetitive control approach

DEFF Research Database (Denmark)

Zou, Zhixiang; Wang, Zheng; Cheng, Ming

2012-01-01

This paper presents an digital dual-mode-structure repetitive control approach for the single-phase shunt active power filter (APF), which aims to enhance the tracking ability and eliminate arbitrary order harmonic. The proposed repetitive control scheme blends the characteristics of both odd......-harmonic repetitive control and even-harmonic repetitive control. Moreover, the convergence rate is faster than conventional repetitive controller. Additionally, the parameters have been designed and optimized for the dual-mode structure repetitive control to improve the performance of APF system. Experimental...

A 380pW Dual Mode Optical Wake-up Receiver with Ambient Noise Cancellation.

Science.gov (United States)

Lim, Wootaek; Jang, Taekwang; Lee, Inhee; Kim, Hun-Seok; Sylvester, Dennis; Blaauw, David

2016-06-01

We present a sub-nW optical wake-up receiver for wireless sensor nodes. The wake-up receiver supports dual mode operation for both ultra-low standby power and high data rates, while canceling ambient in-band noise. In 0.18µm CMOS the receiver consumes 380pW in always-on wake-up mode and 28.1µW in fast RX mode at 250kbps.

Improved dose localization with dual energy photon irradiation in treatment of lateralized intracranial malignancies

International Nuclear Information System (INIS)

Cooley, G.; Gillin, M.T.; Murray, K.J.; Wilson, J.F.; Janjan, N.A.

1991-01-01

Dual energy photon irradiation (6 MV and 20 MV) was compared to conventional treatment planning with 6 MV photons in a lateralized intracranial malignancy. Dose volume analysis was performed of both the tumor plus a 2 cm margin (target volume, TV) and normal tissues (NT). Parallel opposed treatment using weightings of 1:1, 1.5:1, and 2:1 were compared for 6 MV photons alone or in combination with 20 MV photons. Uniform treatment of the TV was accomplished within the 60 Gy isodose. Significant differences were observed, however, in NT volumes receiving greater than or equal to 60 Gy and 45-59 Gy. Dual photon energy reduced treatment of NT volumes to greater than or equal to 60 Gy by 13% (177 cm3 vs 204 cm3 in 2:1 weighting) to 70% (147 cm3 vs 498 cm3 in 1:1 weighting) for comparable plans. Dose optimization was also performed for both 6 MV alone or in combination with 20 MV photons. Usual approaches to achieve dose lateralization with conventional isocentric techniques were applied including parallel opposed 6 MV photons ipsilaterally weighted 3.4:1 (POP), and a 110 degrees arc rotational field used to limit treatment to the eye (ARC). Dual energy photon optimized plans included a three beam parallel opposed plan (TOP) and a mixed photon ipsilateral (IPSI) approach. The technique using parallel opposed 20 MV photons and ipsilateral 6 MV photons (TOP) used beam weightings of 1.1 (contralateral 20 MVX): 1.6 (ipsilateral 6 MVX): 1 (ipsilateral 20 MVX) to achieve dose optimization. The ipsilateral approach with 6 MVX and 20 MVX (IPSI) used beam weightings of 1:1.4, respectively. All optimized plans demonstrated a 41% (120 cm3; POP) to 53% (95 cm3; TOP) improvement over parallel opposed 6 MV photons weighted 2:1 (204 cm3) in NT volume receiving greater than or equal to 60 Gy

Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Suita, Osaka (Japan); Yoshiya, Kazuhisa; Shimazu, Takeshi [Osaka University Graduate School of Medicine, Department of Traumatology and Acute Critical Medicine, Osaka (Japan)

2014-04-15

Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage. (orig.)

Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage.

Science.gov (United States)

Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Yoshiya, Kazuhisa; Shimazu, Takeshi; Tomiyama, Noriyuki

2014-04-01

Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage.

Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage

International Nuclear Information System (INIS)

Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Tomiyama, Noriyuki; Yoshiya, Kazuhisa; Shimazu, Takeshi

2014-01-01

Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage. (orig.)

A novel dual mode neutron-gamma imager

International Nuclear Information System (INIS)

Cooper, Robert Lee; Gerling, Mark; Brennan, James S.; Mascarenhas, Nicholas; Mrowka, Stanley; Marleau, Peter

2010-01-01

The Neutron Scatter Camera (NSC) can image fission sources and determine their energy spectra at distances of tens of meters and through significant thicknesses of intervening materials in relatively short times (1). We recently completed a 32 element scatter camera and will present recent advances made with this instrument. A novel capability for the scatter camera is dual mode imaging. In normal neutron imaging mode we identify and image neutron events using pulse shape discrimination (PSD) and time of flight in liquid scintillator. Similarly gamma rays are identified from Compton scatter in the front and rear planes for our segmented detector. Rather than reject these events, we show it is possible to construct a gamma-ray image by running the analysis in a 'Compton mode'. Instead of calculating the scattering angle by the kinematics of elastic scatters as is appropriate for neutron events, it can be found by the kinematics of Compton scatters. Our scatter camera has not been optimized as a Compton gamma-ray imager but is found to work reasonably. We studied imaging performance using a Cs137 source. We find that we are able to image the gamma source with reasonable fidelity. We are able to determine gamma energy after some reasonable assumptions. We will detail the various algorithms we have developed for gamma image reconstruction. We will outline areas for improvement, include additional results and compare neutron and gamma mode imaging.

Spectrally interleaved, comb-mode-resolved spectroscopy using swept dual terahertz combs.

Science.gov (United States)

Hsieh, Yi-Da; Iyonaga, Yuki; Sakaguchi, Yoshiyuki; Yokoyama, Shuko; Inaba, Hajime; Minoshima, Kaoru; Hindle, Francis; Araki, Tsutomu; Yasui, Takeshi

2014-01-22

Optical frequency combs are innovative tools for broadband spectroscopy because a series of comb modes can serve as frequency markers that are traceable to a microwave frequency standard. However, a mode distribution that is too discrete limits the spectral sampling interval to the mode frequency spacing even though individual mode linewidth is sufficiently narrow. Here, using a combination of a spectral interleaving and dual-comb spectroscopy in the terahertz (THz) region, we achieved a spectral sampling interval equal to the mode linewidth rather than the mode spacing. The spectrally interleaved THz comb was realized by sweeping the laser repetition frequency and interleaving additional frequency marks. In low-pressure gas spectroscopy, we achieved an improved spectral sampling density of 2.5 MHz and enhanced spectral accuracy of 8.39 × 10(-7) in the THz region. The proposed method is a powerful tool for simultaneously achieving high resolution, high accuracy, and broad spectral coverage in THz spectroscopy.

Spectrally interleaved, comb-mode-resolved spectroscopy using swept dual terahertz combs

Science.gov (United States)

Hsieh, Yi-Da; Iyonaga, Yuki; Sakaguchi, Yoshiyuki; Yokoyama, Shuko; Inaba, Hajime; Minoshima, Kaoru; Hindle, Francis; Araki, Tsutomu; Yasui, Takeshi

2014-01-01

Optical frequency combs are innovative tools for broadband spectroscopy because a series of comb modes can serve as frequency markers that are traceable to a microwave frequency standard. However, a mode distribution that is too discrete limits the spectral sampling interval to the mode frequency spacing even though individual mode linewidth is sufficiently narrow. Here, using a combination of a spectral interleaving and dual-comb spectroscopy in the terahertz (THz) region, we achieved a spectral sampling interval equal to the mode linewidth rather than the mode spacing. The spectrally interleaved THz comb was realized by sweeping the laser repetition frequency and interleaving additional frequency marks. In low-pressure gas spectroscopy, we achieved an improved spectral sampling density of 2.5 MHz and enhanced spectral accuracy of 8.39 × 10-7 in the THz region. The proposed method is a powerful tool for simultaneously achieving high resolution, high accuracy, and broad spectral coverage in THz spectroscopy.

Dual Z-Source Inverter With Three-Level Reduced Common-Mode Switching

DEFF Research Database (Denmark)

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

2007-01-01

This paper presents the design of a dual Z-source inverter that can be used with either a single dc source or two isolated dc sources. Unlike traditional inverters, the integration of a properly designed Z-source network and semiconductor switches to the proposed dual inverter allows buck......-boost power conversion to be performed over a wide modulation range, with three-level output waveforms generated. The connection of an additional transformer to the inverter ac output also allows all generic wye-or delta-connected loads with three-wire or four-wire configuration to be supplied by the inverter....... Modulationwise, the dual inverter can be controlled using a carefully designed carrier-based pulsewidth-modulation (PWM) scheme that will always ensure balanced voltage boosting of the Z-source network while simultaneously achieving reduced common-mode switching. Because of the omission of dead-time delays...

Mode switching control of dual-evaporator air-conditioning systems

International Nuclear Information System (INIS)

Lin, J.-L.; Yeh, T.-J.

2009-01-01

Modern air-conditioners incorporate variable-speed compressors and variable-opening expansion valves as the actuators for improving cooling performance and energy efficiency. These actuators have to be properly feedback-controlled; otherwise the systems may exhibit even poorer performance than the conventional machines which use fixed-speed compressors and mechanical expansion valves. Particularly for an air-conditioner with multiple evaporators, there are occasions that the machine is operated in a mode that only selected evaporator(s) is(are) turned on, and switching(s) between modes occurs(occur) during the control process. In this case, one needs to have more carefully designed control and switching strategies to ensure the system performance. In this paper, a framework for mode switching control of the dual-evaporator air-conditioning (DEAC) system is proposed. The framework is basically an integration of a controller and a dynamic compensator. The controller, which possesses the flow-distribution capability and assumes both evaporators are on throughout the control process, is intended to provide nominal performance. While mode switching is achieved by varying the reference settings in the controller, the dynamic compensator is used to improve the transient responses immediately after the switching. Experiments indicate that the proposed framework can achieve satisfactory indoor temperature regulation and provide bumpless switching between different modes of operation.

A reconfigurable frequency-selective surface for dual-mode multi-band filtering applications

Science.gov (United States)

Majidzadeh, Maryam; Ghobadi, Changiz; Nourinia, Javad

2017-03-01

A reconfigurable single-layer frequency-selective surface (FSS) with dual-mode multi-band modes of operation is presented. The proposed structure is printed on a compact 10 × 10 mm2 FR4 substrate with the thickness of 1.6 mm. A simple square loop is printed on the front side while another one along with two defected vertical arms is deployed on the backside. To realise the reconfiguration, two pin diodes are embedded on the backside square loop. Suitable insertion of conductive elements along with pin diodes yields in dual-mode multi-band rejection of applicable in service frequency ranges. The first operating mode due to diodes' 'ON' state provides rejection of 2.4 GHz WLAN in 2-3 GHz, 5.2/5.8 GHz WLAN and X band in 5-12 GHz, and a part of Ku band in 13.9-16 GHz. In diodes 'OFF' state, the FSS blocks WLAN in 4-7.3 GHz, X band in 8-12.7 GHz as well as part of Ku band in 13.7-16.7 GHz. As well, high attenuation of incident waves is observed by a high shielding effectiveness (SE) in the blocked frequency bands. Also, a stable behaviour against different polarisations and angles of incidence is obtained. Comprehensive studies are conducted on a fabricated prototype to assess its performance from which encouraging results are obtained.

Pricing Models for Dual-channel Reverse Supply Chain Considering Regional Differences under “Internet Recycling” Mode in China

Science.gov (United States)

Wu, Di; Li, Peng; Chen, Juhong

2018-01-01

In recent years, the Internet technology has been deeply influencing recycling industry to make it more intelligent and interconnected. However, most existing papers on “Internet Recycling” neglected the problem of pricing strategy under online and offline channels for different levels of recyclers. Moreover, the effect of regional differences has been emphasized a lot in dual-channel forward supply chain, but recycling field has seldom been concerned about it. In this paper, a recycling system consisting of one recycling center and several third-party recyclers (TPR) was investigated based on traditional mode and dual-channel mode. The dual-channel reverse supply chain model is transformed from traditional mode by the introduction of online channel. It involves two recycling modes, as recycling centre for online recovery and “Recycling center+TPR” for offline recovery. By establishing pricing strategies based on Stackelberg game model, the impacts of regional differences were analysed. Finally, numerical analysis was given to illustrate the effectiveness of the pricing mechanisms and strategies.

Automotive dual-mode hydrogen generation system

Science.gov (United States)

Kelly, D. A.

The automotive dual mode hydrogen generation system is advocated as a supplementary hydrogen fuel means along with the current metallic hydride hydrogen storage method for vehicles. This system consists of utilizing conventional electrolysis cells with the low voltage dc electrical power supplied by two electrical generating sources within the vehicle. Since the automobile engine exhaust manifold(s) are presently an untapped useful source of thermal energy, they can be employed as the heat source for a simple heat engine/generator arrangement. The second, and minor electrical generating means consists of multiple, miniature air disk generators which are mounted directly under the vehicle's hood and at other convenient locations within the engine compartment. The air disk generators are revolved at a speed which is proportionate to the vehicles forward speed and do not impose a drag on the vehicles motion.

High-efficiency dual-modes vortex beam generator with polarization-dependent transmission and reflection properties.

Science.gov (United States)

Tang, Shiwei; Cai, Tong; Wang, Guang-Ming; Liang, Jian-Gang; Li, Xike; Yu, Jiancheng

2018-04-23

Vortex beam is believed to be an effective way to extend communication capacity, but available efforts suffer from the issues of complex configurations, fixed operation mode as well as low efficiency. Here, we propose a general strategy to design dual-modes vortex beam generator by using metasurfaces with polarization-dependent transmission and reflection properties. Combining the focusing and vortex functionalities, we design/fabricate a type of compact dual-modes vortex beam generator operating at both reflection/transmission sides of the system. Experimental results demonstrate that the designed metadevice can switch freely and independently between the reflective vortex with topological charge m 1  = 2 and transmissive vortex with m 2  = 1. Moreover, the metadevice exhibits very high efficiencies of 91% and 85% for the reflective and transmissive case respectively. Our findings open a door for multifunctional metadevices with high performances, which indicate wide applications in modern integration-optics and wireless communication systems.

MO-AB-BRA-04: Correct Identification of Low-Attenuation Intracranial Hemorrhage and Calcification Using Dual-Energy Computed Tomography in a Phantom System

Energy Technology Data Exchange (ETDEWEB)

Nute, J; Jacobsen, M; Popnoe, D [UT MD Anderson Cancer Center, Department of Imaging Physics, Houston, TX (United States); UT Graduate School of Biomedical Sciences at Houston, Houston, TX (United States); Wei, W [UT MD Anderson Cancer Center, Department of Biostatistics, Houston, TX (United States); Baiu, C [Gammex Inc., Middleton, WI (United States); Schellingerhout, D [MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, TX (United States); Cody, D [UT MD Anderson Cancer Center, Department of Imaging Physics, Houston, TX (United States)

2015-06-15

Purpose: Intracranial hemorrhage and calcification with Single-Energy CT (SECT) attenuation below 100HU cannot be reliably identified using currently clinically available means. Calcification is typically benign but hemorrhage can carry a risk of intracranial bleeding and contraindicate use of anticoagulant therapies. A biologically-relevant phantom was used to investigate identification of unknown intracranial lesions using dual-energy CT (DECT) as a verification of prior lesion differentiation results. Methods: Prior phantom work investigating calcification and hemorrhage differentiation resulted in 3D-DECT raw data (water density, calcium density, 68keV) for a range of DECT protocol variations: image thicknesses (1.25, 2.5, 3.75, 5mm), CTDIvol (36.7 to 132.6mGy) and reconstruction algorithms (Soft, Standard, Detail). Acquisition-specific raw data were used to create a plane of optimal differentiation based on the geometric bisector of 3D-linear regression of the two lesion distributions. Verification hemorrhage and calcification lesions, ranging in size from 0.5 to 1.5cm, were created at varying attenuation from 50 to 100HU. Lesions were inserted into a biologically-relevant brain phantom and scanned using SECT (3.75mm images, Standard, 67mGy) and a range of DECT protocols (3.75mm images, Standard, [67, 105.6, 132.6mGy]). 3D-DECT data were collected and blinded for analysis. The 3D-DECT distribution of the lesion was then compared to the acquisition-matched geometric bisector plane and the mean lesion value’s position relative to the plane, indicating lesion identity, and the percentage of voxels on the identified side of the plane, indicating identification confidence, were derived. Results: 98% of the 120 lesions investigated were identified correctly as hemorrhage or calcification. 74% were identified with greater than 80% confidence. Increases in CTDIvol and lesion diameter were associated with increased identification confidence. Conclusion: Intracranial

Unidirectional, dual-comb lasing under multiple pulse formation mechanisms in a passively mode-locked fiber ring laser

Science.gov (United States)

Liu, Ya; Zhao, Xin; Hu, Guoqing; Li, Cui; Zhao, Bofeng; Zheng, Zheng

2016-09-01

Dual-comb lasers from which asynchronous ultrashort pulses can be simultaneously generated have recently become an interesting research subject. They could be an intriguing alternative to the current dual-laser optical-frequency-comb source with highly sophisticated electronic control systems. If generated through a common light path traveled by all pulses, the common-mode noises between the spectral lines of different pulse trains could be significantly reduced. Therefore, coherent dual-comb generation from a completely common-path, unidirectional lasing cavity would be an interesting territory to explore. In this paper, we demonstrate such a dual-comb lasing scheme based on a nanomaterial saturable absorber with additional pulse narrowing and broadening mechanisms concurrently introduced into a mode-locked fiber laser. The interactions between multiple soliton formation mechanisms result in unusual bifurcation into two-pulse states with quite different characteristics. Simultaneous oscillation of pulses with four-fold difference in pulsewidths and tens of Hz repetition rate difference is observed. The coherence between these spectral-overlapped, picosecond and femtosecond pulses is further verified by the corresponding asynchronous cross-sampling and dual-comb spectroscopy measurements.

MR imaging of recent non-traumatic intracranial hemorrhage: early experience at 3 T

International Nuclear Information System (INIS)

Griffiths, Paul D.; Wilkinson, Iain D.

2006-01-01

Magnetic resonance imaging (MRI) using 3.0 T scanners in the clinical environment is in its infancy and is only available at a limited number of sites worldwide. There is great interest amongst radiologists about the perceived benefits of clinical imaging at 3.0 T; however, it remains to be seen whether the theoretical advantages will bring real gains. MRI in patients with non-traumatic intracranial hemorrhage (ICH) is difficult, yet, these patients benefit from non-invasive angiography. Conventional catheter angiography (CCA) remains the reference standard for excluding/confirming the presence of intracranial vascular abnormalities, but MR angiography at 3.0 T may offer opportunities for significant changes in patient management. We present our experiences of using 3.0 T MR angiography in 27 patients with acute or early subacute ICH. (orig.)

Dual Rotating Rake Measurements of Higher-Order Duct Modes: Validation Using Experimental and Numerical Data

Science.gov (United States)

Dahl, Milo D.; Hixon, Duane R.; Sutliff, Daniel L.

2018-01-01

A rotating rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. After analysis of the measured data, the mode coefficient amplitudes and phases were quantified. Early studies using this system found that mode power levels computed from rotating rake measured data would agree with the far-field power levels. However, this agreement required that the sound from the noise sources within the duct propagated outward from the duct exit without reflection and previous studies suggested conditions could exist where significant reflections could occur. This paper shows that mounting a second rake to the rotating system, with an offset in both the axial and the azimuthal directions, measures the data necessary to determine the modes propagating in both directions within a duct. The rotating rake data analysis technique was extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode coefficients at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode coefficients for the modes propagating in both directions within the duct while accounting for the presence of evanescent modes. The validation of the dual-rotating-rake measurements was conducted using data from a combination of experiments and numerical calculations to compute reflection coefficients and other mode coefficient ratios. Compared to results from analytical and numerical computations, the results from dual-rotating-rake measured data followed the expected trends when frequency, mode number, and duct termination geometry were changed.

An effort to enhance hydrogen energy share in a compression ignition engine under dual-fuel mode using low temperature combustion strategies

International Nuclear Information System (INIS)

Chintala, V.; Subramanian, K.A.

2015-01-01

Highlights: • H 2 energy share increased from 18% with DDM to 36% with WDM (water injection). • H 2 energy share improved marginally with retarded injection timing mode (RDM). • Energy efficiency increased with increasing amount of H 2 in dual-fuel engine. • NO x emission decreased with water injection and retarded pilot fuel injection. • HC, CO and smoke emissions increased slightly with low temperature combustion. - Abstract: A limited hydrogen (H 2 ) energy share due to knocking is the major hurdle for effective utilization of H 2 in compression ignition (CI) engines under dual-fuel operation. The present study aims at improvement of H 2 energy share in a 7.4 kW direct injection CI engine under dual-fuel mode with two low temperature combustion (LTC) strategies; (i) retarded pilot fuel injection timing and (ii) water injection. Experiments were carried out under conventional strategies of diesel dual-fuel mode (DDM) and B20 dual-fuel mode (BDM); and LTC strategies of retarded injection timing dual-fuel mode (RDM) and water injected dual-fuel mode (WDM). The results explored that the H 2 energy share increased significantly from 18% with conventional DDM to 24, and 36% with RDM, and WDM respectively. The energy efficiency increased with increasing H 2 energy share under dual-fuel operation; however, for a particular energy share of 18% H 2 , it decreased from 34.8% with DDM to 33.7% with BDM, 32.7% with WDM and 29.9% with RDM. At 18% H 2 energy share, oxides of nitrogen emission decreased by 37% with RDM and 32% with WDM as compared to conventional DDM due to reduction of in-cylinder temperature, while it increased slightly about 5% with BDM. It is emerged from the study that water injection technique is the viable option among all other strategies to enhance the H 2 energy share in the engine with a slight penalty of increase in smoke, hydrocarbon, and carbon monoxide emissions

Tunable single and dual mode operation of an external cavity quantum-dot injection laser

International Nuclear Information System (INIS)

Biebersdorf, A; Lingk, C; De Giorgi, M; Feldmann, J; Sacher, J; Arzberger, M; Ulbrich, C; Boehm, G; Amann, M-C; Abstreiter, G

2003-01-01

We investigate quantum-dot (QD) lasers in an external cavity using Littrow and Littman configurations. Here, we report on a continuously tunable QD laser with a broad tuning range from 1047 to 1130 nm with high stability and efficient side mode suppression. The full-width at half-maximum of the laser line is 0.85 nm determined mainly by the quality of the external grating. This laser can be operated in a dual-mode modus, where the mode-spacing can be tuned continuously between 1.1 and 34 nm. Simultaneous emission of the two laser modes is shown by sum frequency generation experiments

A tunable and switchable single-longitudinal-mode dual-wavelength fiber laser with a simple linear cavity.

Science.gov (United States)

He, Xiaoying; Fang, Xia; Liao, Changrui; Wang, D N; Sun, Junqiang

2009-11-23

A simple linear cavity erbium-doped fiber laser based on a Fabry-Perot filter which consists of a pair of fiber Bragg gratings is proposed for tunable and switchable single-longitudinal-mode dual-wavelength operation. The single-longitudinal-mode is obtained by the saturable absorption of an unpumed erbium-doped fiber together with a narrow-band fiber Bragg grating. Under the high pump power (>166 mW) condition, the stable dual-wavelength oscillation with uniform amplitude can be realized by carefully adjusting the polarization controller in the cavity. Wavelength selection and switching are achieved by tuning the narrow-band fiber Bragg grating in the system. The spacing of the dual-wavelength can be selected at 0.20 nm (approximately 25.62 GHz), 0.22 nm (approximately 28.19 GHz) and 0.54 nm (approximately 69.19 GHz).

Catheter-based time-gated near-infrared fluorescence/OCT imaging system

Science.gov (United States)

Lu, Yuankang; Abran, Maxime; Cloutier, Guy; Lesage, Frédéric

2018-02-01

We developed a new dual-modality intravascular imaging system based on fast time-gated fluorescence intensity imaging and spectral domain optical coherence tomography (SD-OCT) for the purpose of interventional detection of atherosclerosis. A pulsed supercontinuum laser was used for fluorescence and OCT imaging. A double-clad fiber (DCF)- based side-firing catheter was designed and fabricated to have a 23 μm spot size at a 2.2 mm working distance for OCT imaging. Its single-mode core is used for OCT, while its inner cladding transports fluorescence excitation light and collects fluorescent photons. The combination of OCT and fluorescence imaging was achieved by using a DCF coupler. For fluorescence detection, we used a time-gated technique with a novel single-photon avalanche diode (SPAD) working in an ultra-fast gating mode. A custom-made delay chip was integrated in the system to adjust the delay between the excitation laser pulse and the SPAD gate-ON window. This technique allowed to detect fluorescent photons of interest while rejecting most of the background photons, thus leading to a significantly improved signal to noise ratio (SNR). Experiments were carried out in turbid media mimicking tissue with an indocyanine green (ICG) inclusion (1 mM and 100 μM) to compare the time-gated technique and the conventional continuous detection technique. The gating technique increased twofold depth sensitivity, and tenfold SNR at large distances. The dual-modality imaging capacity of our system was also validated with a silicone-based tissue-mimicking phantom.

Efficacy of a one-catheter concept for transradial coronary angiography.

Directory of Open Access Journals (Sweden)

Christoph Langer

Full Text Available Transradial coronary angiography (TRC can be performed with a one-catheter approach for the right and left coronary ostium (R/LCO. We investigated the performance of a special diagnostic catheter widely used for the one-catheter-approach, the Tiger (Tiger II, TerumoTM.In a dual center registry we analyzed 1412 TRC-procedures exclusively performed by experienced TRC-operators. We compared the performance of the Tiger with Judkins catheters by retrospectively judging ostial catheter stability during contrast injection, and by measuring contrast use, fluoroscopy time (FT and complication rate.Poor or failed ostial engagement was found in 40.5% in the Tiger group, compared to 46.6% with the use of Judkins catheters (p<0.183. Ostial instability of the Tiger was found more often during engagement of the LCO than the RCO (34.4% vs. 10.8%, p<0.001, whereas it was similar in the LCO and RCO for Judkins catheters (27.4% vs. 26.7%, p = 0.840. TRC-procedures performed with Tiger catheters were associated with less contrast volume (63.48 ± 29.83mL vs. 82.51 ± 56.58mL, p<0.004 and shorter FT than with Judkins catheters. (198.27 ± 194.8sec vs. 326.85 ± 329.70sec. Forearm hematomas occurred less often with the Tiger (1.2% vs. 6.6%, p< 0.02.The Tiger employed as a single catheter in TRC is an effective tool to achieve lower contrast volume and fluoroscopy time at a low complication rate. Unstable engagement affects predominantly the left coronary artery, but its overall frequency is similar for both, the Tiger and Judkins catheters.

Remote heterodyne millimeter-wave over fiber based OFDM-PON with master-to-slave injected dual-mode colorless FPLD pair.

Science.gov (United States)

Chen, Hsiang-Yu; Chi, Yu-Chieh; Lin, Gong-Ru

2015-08-24

A remote heterodyne millimeter-wave (MMW) carrier at 47.7 GHz over fiber synthesized with the master-to-slave injected dual-mode colorless FPLD pair is proposed, which enables the future connection between the wired fiber-optic 64-QAM OFDM-PON at 24 Gb/s with the MMW 4-QAM OFDM wireless network at 2 Gb/s. Both the single- and dual-mode master-to-slave injection-locked colorless FPLD pairs are compared to optimize the proposed 64-QAM OFDM-PON. For the unamplified single-mode master, the slave colorless FPLD successfully performs the 64-QAM OFDM data at 24 Gb/s with EVM, SNR and BER of 8.5%, 21.5 dB and 2.9 × 10(-3), respectively. In contrast, the dual-mode master-to-slave injection-locked colorless FPLD pair with amplified and unfiltered master can transmit 64-QAM OFDM data at 18 Gb/s over 25-km SMF to provide EVM, SNR and BER of 8.2%, 21.8 dB and 2.2 × 10(-3), respectively. For the dual-mode master-to-slave injection-locked colorless FPLD pair, even though the modal dispersion occurred during 25-km SMF transmission makes it sacrifice the usable OFDM bandwidth by only 1 GHz, which guarantees the sufficient encoding bitrate for the optically generated MMW carrier to implement the fusion of MMW wireless LAN and DWDM-PON with cost-effective and compact architecture. As a result, the 47.7-GHz MMW carrier remotely beat from the dual-mode master-to-slave injection-locked colorless FPLD pair exhibits an extremely narrow bandwidth of only 0.48 MHz. After frequency down-conversion operation, the 47.7-GHz MMW carrier successfully delivers 4-QAM OFDM data up to 2 Gb/s with EVM, SNR and BER of 33.5%, 9.51 dB and 1.4 × 10(-3), respectively.

Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

International Nuclear Information System (INIS)

Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark

1997-01-01

To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis

Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark [Kosin Medical College, Pusan (Korea, Republic of)

1997-11-01

To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis.

Unidirectional, dual-comb lasing under multiple pulse formation mechanisms in a passively mode-locked fiber ring laser

OpenAIRE

Liu, Ya; Zhao, Xin; Hu, Guoqing; Li, Cui; Zhao, Bofeng; Zheng, Zheng

2016-01-01

Dual-comb lasers from which asynchronous ultrashort pulses can be simultaneously generated have recently become an interesting research subject. They could be an intriguing alternative to the current dual-laser optical-frequency-comb source with highly sophisticated electronic control systems. If generated through a common light path traveled by all pulses, the common-mode noises between the spectral lines of different pulse trains could be significantly reduced. Therefore, coherent dual-comb...

Micro packaged MEMS pressure sensor for intracranial pressure measurement

International Nuclear Information System (INIS)

Liu Xiong; Yao Yan; Ma Jiahao; Zhang Zhaohua; Zhang Yanhang; Wang Qian; Ren Tianling

2015-01-01

This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Miniaturization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm 2 . It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm 2 . In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm 2 . Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10 −2 mV/kPa. (paper)

Determination of lesion size by ultrasound during radiofrequency catheter ablation.

Science.gov (United States)

Awad, S; Eick, O

2003-01-01

The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging.

Dual-Mode Dual-Band Microstrip Bandpass Filter Based on Fourth Iteration T-Square Fractal and Shorting Pin

Directory of Open Access Journals (Sweden)

E. S. Ahmed

2012-06-01

Full Text Available A new class of dual mode microstrip fractal resonator is proposed and developed for miniaturization of the dual band bandpass filter. The perimeter of the proposed resonator is increased by employing fourth iteration T-square fractal shape. Consequently the lower resonant frequency of the filter is decreased without increasing the usable space. The self similarity of the usable structure enables it to produce the two degenerate modes which are coupled using the proper perturbation technique. The shorting pin is placed at the null in the surface current distribution at the center of the resonator. This shorting pin is coactively coupled to the resonant circuit of the resonator, effectively coupled to the lower degenerate mode and reduces the lower edge band resonant frequency. By adjusting the resonator dimensions and the size of the shorting pin, the resonant frequency and the out-of-band rejection around the transmission bands can be controlled to meet the design requirements. The simulated response of the designed filter has two transmission bands, the first band is from 2.34-3.65 GHz with resonant frequencies at 2.47GHz and 3.55GHz, the second band is from 4.37-5.324GHz with resonant frequencies at 4.5GHz and 5.13GHz. In the pass bands, the group delay is less than 0.65 ns. The proposed filter can be applied to WLAN (2.4 GHz and 5.2 GHz and WiMAX (3.5 GHz and Bluetooth and ZigBee (4.9 GHz.

Dual-Mode Gas Sensor Composed of a Silicon Nanoribbon Field Effect Transistor and a Bulk Acoustic Wave Resonator: A Case Study in Freons

Directory of Open Access Journals (Sweden)

Ye Chang

2018-01-01

Full Text Available In this paper, we develop a novel dual-mode gas sensor system which comprises a silicon nanoribbon field effect transistor (Si-NR FET and a film bulk acoustic resonator (FBAR. We investigate their sensing characteristics using polar and nonpolar organic compounds, and demonstrate that polarity has a significant effect on the response of the Si-NR FET sensor, and only a minor effect on the FBAR sensor. In this dual-mode system, qualitative discrimination can be achieved by analyzing polarity with the Si-NR FET and quantitative concentration information can be obtained using a polymer-coated FBAR with a detection limit at the ppm level. The complementary performance of the sensing elements provides higher analytical efficiency. Additionally, a dual mixture of two types of freons (CFC-113 and HCFC-141b is further analyzed with the dual-mode gas sensor. Owing to the small size and complementary metal-oxide semiconductor (CMOS-compatibility of the system, the dual-mode gas sensor shows potential as a portable integrated sensing system for the analysis of gas mixtures in the future.

Impact of metal artifact reduction software on image quality of gemstone spectral imaging dual-energy cerebral CT angiography after intracranial aneurysm clipping

Energy Technology Data Exchange (ETDEWEB)

Dunet, Vincent; Bernasconi, Martine; Hajdu, Steven David; Meuli, Reto Antoine; Zerlauth, Jean-Baptiste [Lausanne University Hospital, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Daniel, Roy Thomas [Lausanne University Hospital, Department of Neurosurgery, Lausanne (Switzerland)

2017-09-15

We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after intracranial aneurysm clipping. This retrospective study was approved by the institutional review board, which waived patient written consent. From January 2013 to September 2016, single source DE cerebral CTA were performed in 45 patients (mean age: 60 ± 9 years, male 9) after intracranial aneurysm clipping and reconstructed with and without MARs. Signal-to-noise (SNR), contrast-to-noise (CNR), and relative CNR (rCNR) ratios were calculated from attenuation values measured in the internal carotid artery (ICA) and middle cerebral artery (MCA). Volume of clip and artifacts and relative clip blurring reduction (rCBR) ratios were also measured at each energy level with/without MARs. Variables were compared between GSI and GSI-MARs using the paired Wilcoxon signed-rank test. MARs significantly reduced metal artifacts at all energy levels but 130 and 140 keV, regardless of clips' location and number. The optimal rCBR was obtained at 110 and 80 keV, respectively, on GSI and GSI-MARs images, with up to 96% rCNR increase on GSI-MARs images. The best compromise between metal artifact reduction and rCNR was obtained at 70-75 and 65-70 keV for GSI and GSI-MARs images, respectively, with up to 15% rCBR and rCNR increase on GSI-MARs images. MARs significantly reduces metal artifacts on DE cerebral CTA after intracranial aneurysm clipping regardless of clips' location and number. It may be used to reduce radiation dose while increasing CNR. (orig.)

Monitoring of Intracranial Pressure During Intracranial Endoscopy

Directory of Open Access Journals (Sweden)

Rajeev Kumar

2013-08-01

Full Text Available Background: Intracranial endoscopy is a minimum invasive procedure, which reduces trauma to the brain, is cost-effective, and carries a shortened hospital stay with an improved postoperative outcome. Objective: To monitor intracranial pressure changes during intracranial endoscopy among children and adults under general anesthesia/sedation, and to compare the intracranial pressure changes between children and adults receiving general anesthesia and among adults receiving general anesthesia and sedation. Methods: The present cross-sectional study was conducted in one of the tertiary care hospitals of Lucknow. This was carried out in the department of neurosurgery from January 2008 to December 2008. Patients who were not fit for general anesthesia received local anesthesia under sedation. Patients participating in the study were divided into three groups. Intracranial pressure was recorded at specific intervals. Parametric data were subjected to statistical analysis using a student\\s t test. Result: A total of 70 patients were undergoing intracranial endoscopy under general anesthesia during the study period. In both groups A and B, intracranial pressure increases the maximum during inflation of the balloon. In group C, all the variations in ICP were found to be statistically significant. In the comparison of intracranial pressure changes between groups A and B, no significant difference was found. All correlations in the comparison of groups B and C were found to be statistically significant (p< 0.001. Conclusion: There is a need for continuous intraoperative monitoring of ICP intracranial endoscopy, because ICP increases in various stages of the procedure, which can be detrimental to the perfusion of the brain. [Arch Clin Exp Surg 2013; 2(4.000: 240-245

Vibrational correlation between conjugated carbonyl and diazo modes studied by single- and dual-frequency two-dimensional infrared spectroscopy

International Nuclear Information System (INIS)

Maekawa, Hiroaki; Sul, Soohwan; Ge, Nien-Hui

2013-01-01

Highlights: ► Vibrational dynamics of conjugated C=O and N=N modes of ethyl diazoacetate was studied. ► Their frequency–frequency correlation functions are different. ► The dual-frequency 2D IR spectrum indicates anticorrelated frequency fluctuations. ► Correlation effects on dual-frequency 2D IR spectra are discussed. ► The existence of cis and trans conformers is revealed in 2D IR spectra. - Abstract: We have applied infrared three-pulse photon echo and single- and dual-frequency 2D IR spectroscopy to the ester C=O and diazo N=N stretching modes in ethyl diazoacetate (EDA), and investigated their vibrational frequency fluctuations and correlation. The two modes exhibit different vibrational dynamics and 2D lineshape, which are well simulated by frequency–frequency correlation functions (FFCFs) with two decaying components. Although the FT IR spectrum shows a single C=O band, absolute magnitude 2D IR nonrephasing spectrum displays spectral signatures supporting the presence of cis and trans conformations. The cross-peak inclined toward the anti-diagonal in the dual-frequency 2D IR spectrum, indicating that the frequency fluctuations of the two modes are anticorrelated. This behavior is attributed to anticorrelated change in the bond orders when solvent and structural fluctuations causes EDA to adopt a different mixture of the two dominant resonance structures. The effects of cross FFCF on the cross-peak line shape are discussed

Vibrational correlation between conjugated carbonyl and diazo modes studied by single- and dual-frequency two-dimensional infrared spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Maekawa, Hiroaki; Sul, Soohwan [Department of Chemistry, University of California at Irvine, Irvine, CA 92697-2025 (United States); Ge, Nien-Hui, E-mail: nhge@uci.edu [Department of Chemistry, University of California at Irvine, Irvine, CA 92697-2025 (United States)

2013-08-30

Highlights: ► Vibrational dynamics of conjugated C=O and N=N modes of ethyl diazoacetate was studied. ► Their frequency–frequency correlation functions are different. ► The dual-frequency 2D IR spectrum indicates anticorrelated frequency fluctuations. ► Correlation effects on dual-frequency 2D IR spectra are discussed. ► The existence of cis and trans conformers is revealed in 2D IR spectra. - Abstract: We have applied infrared three-pulse photon echo and single- and dual-frequency 2D IR spectroscopy to the ester C=O and diazo N=N stretching modes in ethyl diazoacetate (EDA), and investigated their vibrational frequency fluctuations and correlation. The two modes exhibit different vibrational dynamics and 2D lineshape, which are well simulated by frequency–frequency correlation functions (FFCFs) with two decaying components. Although the FT IR spectrum shows a single C=O band, absolute magnitude 2D IR nonrephasing spectrum displays spectral signatures supporting the presence of cis and trans conformations. The cross-peak inclined toward the anti-diagonal in the dual-frequency 2D IR spectrum, indicating that the frequency fluctuations of the two modes are anticorrelated. This behavior is attributed to anticorrelated change in the bond orders when solvent and structural fluctuations causes EDA to adopt a different mixture of the two dominant resonance structures. The effects of cross FFCF on the cross-peak line shape are discussed.

Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

International Nuclear Information System (INIS)

Anfinsen, Ole-Gunnar

1999-01-01

The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks related to

Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

Energy Technology Data Exchange (ETDEWEB)

Anfinsen, Ole-Gunnar

1999-07-01

The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks

Dual mode linguistic hedge fuzzy logic controller for an isolated wind-diesel hybrid power system with superconducting magnetic energy storage unit

International Nuclear Information System (INIS)

Thameem Ansari, M.Md.; Velusami, S.

2010-01-01

A design of dual mode linguistic hedge fuzzy logic controller for an isolated wind-diesel hybrid power system with superconducting magnetic energy storage unit is proposed in this paper. The design methodology of dual mode linguistic hedge fuzzy logic controller is a hybrid model based on the concepts of linguistic hedges and hybrid genetic algorithm-simulated annealing algorithms. The linguistic hedge operators are used to adjust the shape of the system membership functions dynamically and can speed up the control result to fit the system demand. The hybrid genetic algorithm-simulated annealing algorithm is adopted to search the optimal linguistic hedge combination in the linguistic hedge module. Dual mode concept is also incorporated in the proposed controller because it can improve the system performance. The system with the proposed controller was simulated and the frequency deviation resulting from a step load disturbance is presented. The comparison of the proportional plus integral controller, fuzzy logic controller and the proposed dual mode linguistic hedge fuzzy logic controller shows that, with the application of the proposed controller, the system performance is improved significantly. The proposed controller is also found to be less sensitive to the changes in the parameters of the system and also robust under different operating modes of the hybrid power system.

Malfunctioning and infected tunneled infusion catheters: over-the-wire catheter exchange versus catheter removal and replacement.

Science.gov (United States)

Guttmann, David M; Trerotola, Scott O; Clark, Timothy W; Dagli, Mandeep; Shlansky-Goldberg, Richard D; Itkin, Maxim; Soulen, Michael C; Mondschein, Jeffrey I; Stavropoulos, S William

2011-05-01

To compare the safety and effectiveness of over-the-wire catheter exchange (catheter-exchange) with catheter removal and replacement (removal-replacement) at a new site for infected or malfunctioning tunneled infusion catheters. Using a quality assurance database, 61 patients with tunneled infusion catheters placed during the period July 2001 to June 2009 were included in this study. Patients receiving hemodialysis catheters were excluded. Catheter-exchange was performed in 25 patients, and same-day removal-replacement was performed in 36 patients. Data collected included demographic information, indication for initial catheter placement and replacement, dwell time for the new catheter, and ultimate fate of the new device. Statistical comparisons between the two cohorts were analyzed using the Kaplan-Meier technique and Fisher exact test. Catheters exchanged over the wire remained functional without infection for a median of 102 days (range, 2-570 days), whereas catheters removed and replaced were functional for a median 238 days (range, 1-292 days, P = .12). After catheter replacement, there were 11 instances of subsequent infection in the catheter-exchange group and 7 instances in the removal-replacement cohort, accounting for infection rates of 4.4 and 2.3 per 1,000 catheter days (P = .049). Patients in the catheter-exchange group had 3.2 greater odds of infection compared with patients in the removal-replacement group. Five malfunction events occurred in each group, accounting for 2.0 and 1.7 malfunctions per 1,000 catheter days in the catheter-exchange and removal-replacement groups (P = .73). Catheter-exchange of tunneled infusion catheters results in a higher infection rate compared with removal-replacement at a new site. The rate of catheter malfunction is not significantly different between the two groups. Catheter-exchange is an alternative for patients with tunneled infusion catheters who have limited venous access, but this technique should not be

WE-G-BRA-09: Microsphere Brachytherapy Failure Mode and Effects Analysis in a Dual-Vendor Environment

International Nuclear Information System (INIS)

Younge, K C; Lee, C I; Feng, M; Novelli, P; Moran, J M; Prisciandaro, J I

2015-01-01

Purpose: To improve the safety and quality of a dual-vendor microsphere brachytherapy program with failure mode and effects analysis (FMEA). Methods: A multidisciplinary team including physicists, dosimetrists, a radiation oncologist, an interventional radiologist, and radiation safety personnel performed an FMEA for our dual-vendor microsphere brachytherapy program employing SIR-Spheres (Sirtex Medical Limited, Australia) and Theraspheres (BTG, England). We developed a program process tree and step-by-step instructions which were used to generate a comprehensive list of failure modes. These modes were then ranked according to severity, occurrence rate, and detectability. Risk priority numbers (RPNs) were calculated by multiplying these three scores together. Three different severity scales were created: one each for harmful effects to the patient, staff, or the institution. Each failure mode was ranked on one or more of these scales. Results: The group identified 164 failure modes for the microsphere program. 113 of these were ranked using the patient severity scale, 52 using the staff severity scale, and 50 using the institution severity scale. The highest ranked items on the patient severity scale were an error in the automated dosimetry worksheet (RPN = 297.5), and the incorrect target specified on the planning study (RPN = 135). Some failure modes ranked differently between vendors, especially those corresponding to dose vial preparation because of the different methods used. Based on our findings, we made several improvements to our QA program, including documentation to easily identify which product is being used, an additional hand calculation during planning, and reorganization of QA steps before treatment delivery. We will continue to periodically review and revise the FMEA. Conclusion: We have applied FMEA to our dual-vendor microsphere brachytherapy program to identify potential key weaknesses in the treatment chain. Our FMEA results were used to

WE-G-BRA-09: Microsphere Brachytherapy Failure Mode and Effects Analysis in a Dual-Vendor Environment

Energy Technology Data Exchange (ETDEWEB)

Younge, K C; Lee, C I; Feng, M; Novelli, P; Moran, J M; Prisciandaro, J I [Univ Michigan Medical Center, Ann Arbor, MI (United States)

2015-06-15

Purpose: To improve the safety and quality of a dual-vendor microsphere brachytherapy program with failure mode and effects analysis (FMEA). Methods: A multidisciplinary team including physicists, dosimetrists, a radiation oncologist, an interventional radiologist, and radiation safety personnel performed an FMEA for our dual-vendor microsphere brachytherapy program employing SIR-Spheres (Sirtex Medical Limited, Australia) and Theraspheres (BTG, England). We developed a program process tree and step-by-step instructions which were used to generate a comprehensive list of failure modes. These modes were then ranked according to severity, occurrence rate, and detectability. Risk priority numbers (RPNs) were calculated by multiplying these three scores together. Three different severity scales were created: one each for harmful effects to the patient, staff, or the institution. Each failure mode was ranked on one or more of these scales. Results: The group identified 164 failure modes for the microsphere program. 113 of these were ranked using the patient severity scale, 52 using the staff severity scale, and 50 using the institution severity scale. The highest ranked items on the patient severity scale were an error in the automated dosimetry worksheet (RPN = 297.5), and the incorrect target specified on the planning study (RPN = 135). Some failure modes ranked differently between vendors, especially those corresponding to dose vial preparation because of the different methods used. Based on our findings, we made several improvements to our QA program, including documentation to easily identify which product is being used, an additional hand calculation during planning, and reorganization of QA steps before treatment delivery. We will continue to periodically review and revise the FMEA. Conclusion: We have applied FMEA to our dual-vendor microsphere brachytherapy program to identify potential key weaknesses in the treatment chain. Our FMEA results were used to

Dual-Mode SERS-Fluorescence Immunoassay Using Graphene Quantum Dot Labeling on One-Dimensional Aligned Magnetoplasmonic Nanoparticles.

Science.gov (United States)

Zou, Fengming; Zhou, Hongjian; Tan, Tran Van; Kim, Jeonghyo; Koh, Kwangnak; Lee, Jaebeom

2015-06-10

A novel dual-mode immunoassay based on surface-enhanced Raman scattering (SERS) and fluorescence was designed using graphene quantum dot (GQD) labels to detect a tuberculosis (TB) antigen, CFP-10, via a newly developed sensing platform of linearly aligned magnetoplasmonic (MagPlas) nanoparticles (NPs). The GQDs were excellent bilabeling materials for simultaneous Raman scattering and photoluminescence (PL). The one-dimensional (1D) alignment of MagPlas NPs simplified the immunoassay process and enabled fast, enhanced signal transduction. With a sandwich-type immunoassay using dual-mode nanoprobes, both SERS signals and fluorescence images were recognized in a highly sensitive and selective manner with a detection limit of 0.0511 pg mL(-1).

60-GHz Millimeter-wave Over Fiber with Directly Modulated Dual-mode Laser Diode

Science.gov (United States)

Tsai, Cheng-Ting; Lin, Chi-Hsiang; Lin, Chun-Ting; Chi, Yu-Chieh; Lin, Gong-Ru

2016-01-01

A directly modulated dual-mode laser diode (DMLD) with third-order intermodulation distortion (IMD3) suppression is proposed for a 60-GHz millimeter-wave over fiber (MMWoF) architecture, enabling new fiber-wireless communication access to cover 4-km single-mode-fiber (SMF) and 3-m wireless 16-QAM OFDM transmissions. By dual-mode injection-locking, the throughput degradation of the DMLD is mitigated with saturation effect to reduce its threshold, IMD3 power and relative intensity noise to 7.7 mA, −85 dBm and −110.4 dBc/Hz, respectively, providing huge spurious-free dynamic range of 85.8 dB/Hz2/3. This operation suppresses the noise floor of the DMLD carried QPSK-OFDM spectrum by 5 dB. The optical receiving power is optimized to restrict the power fading effect for improving the bit error rate to 1.9 × 10−3 and the receiving power penalty to 1.1 dB. Such DMLD based hybrid architecture for 60-GHz MMW fiber-wireless access can directly cover the current optical and wireless networks for next-generation indoor and short-reach mobile communications. PMID:27297267

Dual-mode ferromagnetic resonance in an FeCoB/Ru/FeCoB synthetic antiferromagnet with uniaxial anisotropy

Science.gov (United States)

Wang, Cuiling; Zhang, Shouheng; Qiao, Shizhu; Du, Honglei; Liu, Xiaomin; Sun, Ruicong; Chu, Xian-Ming; Miao, Guo-Xing; Dai, Youyong; Kang, Shishou; Yan, Shishen; Li, Shandong

2018-05-01

Dual-mode ferromagnetic resonance is observed in FeCoB/Ru/FeCoB trilayer synthetic antiferromagnets with uniaxial in-plane magnetic anisotropy. The optical mode is present in the (0-108 Oe) magnetic field range, where the top and bottom layer magnetizations are aligned in opposite directions. The strong acoustic mode appears, when the magnetic field exceeds the 300 Oe value, which corresponds to the flop transition in the trilayer. Magnetic field and angular dependences of resonant frequencies are studied for both optical (low-field) and acoustic (high field) modes. The low-field mode is found to be anisotropic but insensitive to the magnetic field value. In contrast, the high field mode is quasi-isotropic, but its resonant frequency is tunable by the value of the magnetic field. The coexistence of two modes of ferromagnetic resonance as well as switching between them with the increase in the magnetic field originates from the difference in the sign of interlayer coupling energy at the parallel and antiparallel configurations of the synthetic antiferromagnet. The dual-mode resonance in the studied trilayer structures provides greater flexibility in the design and functionalization of micro-inductors in monolithic microwave integrated circuits.

Spontaneous intracranial arterial dissection in the young: diagnosis by CT angiography

Directory of Open Access Journals (Sweden)

Given Curtis A

2006-04-01

Full Text Available Abstract Background Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography in the young. Case presentation We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the left internal carotid artery (confirmed by catheter arteriography. Studies for vasculitis, pro-thrombotic states, and defects of collagen were negative. Conclusion Spontaneous carotid artery dissection is a potential cause of transient neurological symptoms and ischemic stroke in the pediatric population. Dynamic computed tomography appears to be a reliable diagnostic tool which can lead to early diagnosis.

Catheter Angiography

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Full Text Available ... News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography uses a catheter, x-ray ... are the limitations of Catheter Angiography? What is Catheter Angiography? Angiography is a minimally invasive medical test ...

Stabilization of self-mode-locked quantum dash lasers by symmetric dual-loop optical feedback

Science.gov (United States)

Asghar, Haroon; Wei, Wei; Kumar, Pramod; Sooudi, Ehsan; McInerney, John. G.

2018-02-01

We report experimental studies of the influence of symmetric dual-loop optical feedback on the RF linewidth and timing jitter of self-mode-locked two-section quantum dash lasers emitting at 1550 nm. Various feedback schemes were investigated and optimum levels determined for narrowest RF linewidth and low timing jitter, for single-loop and symmetric dual-loop feedback. Two symmetric dual-loop configurations, with balanced and unbalanced feedback ratios, were studied. We demonstrate that unbalanced symmetric dual loop feedback, with the inner cavity resonant and fine delay tuning of the outer loop, gives narrowest RF linewidth and reduced timing jitter over a wide range of delay, unlike single and balanced symmetric dual-loop configurations. This configuration with feedback lengths 80 and 140 m narrows the RF linewidth by 4-67x and 10-100x, respectively, across the widest delay range, compared to free-running. For symmetric dual-loop feedback, the influence of different power split ratios through the feedback loops was determined. Our results show that symmetric dual-loop feedback is markedly more effective than single-loop feedback in reducing RF linewidth and timing jitter, and is much less sensitive to delay phase, making this technique ideal for applications where robustness and alignment tolerance are essential.

Effect of engine load and biogas flow rate to the performance of a compression ignition engine run in dual-fuel (dieselbiogas) mode

Science.gov (United States)

Ambarita, H.

2018-02-01

The Government of Indonesia (GoI) has released a target on reduction Green Houses Gases emissions (GHG) by 26% from level business-as-usual by 2020, and the target can be up to 41% by international supports. In the energy sector, this target can be reached effectively by promoting fossil fuel replacement or blending with biofuel. One of the potential solutions is operating compression ignition (CI) engine in dual-fuel (diesel-biogas) mode. In this study effects of engine load and biogas flow rate on the performance and exhaust gas emissions of a compression ignition engine run in dual-fuel mode are investigated. In the present study, the used biogas is refined with methane content 70% of volume. The objectives are to explore the optimum operating condition of the CI engine run in dual-fuel mode. The experiments are performed on a four-strokes CI engine with rated output power of 4.41 kW. The engine is tested at constant speed 1500 rpm. The engine load varied from 600W to 1500W and biogas flow rate varied from 0 L/min to 6 L/min. The results show brake thermal efficiency of the engine run in dual-fuel mode is better than pure diesel mode if the biogas flow rates are 2 L/min and 4 L/min. It is recommended to operate the present engine in a dual-fuel mode with biogas flow rate of 4 L/min. The consumption of diesel fuel can be replaced up to 50%.

SERS-Fluorescence Dual-Mode pH-Sensing Method Based on Janus Microparticles.

Science.gov (United States)

Yue, Shuai; Sun, Xiaoting; Wang, Ning; Wang, Yaning; Wang, Yue; Xu, Zhangrun; Chen, Mingli; Wang, Jianhua

2017-11-15

A surface-enhanced Raman scattering (SERS)-fluorescence dual-mode pH-sensing method based on Janus microgels was developed, which combined the advantages of high specificity offered by SERS and fast imaging afforded by fluorescence. Dual-mode probes, pH-dependent 4-mercaptobenzoic acid, and carbon dots were individually encapsulated in the independent hemispheres of Janus microparticles fabricated via a centrifugal microfluidic chip. On the basis of the obvious volumetric change of hydrogels in different pHs, the Janus microparticles were successfully applied for sensitive and reliable pH measurement from 1.0 to 8.0, and the two hemispheres showed no obvious interference. The proposed method addressed the limitation that sole use of the SERS-based pH sensing usually failed in strong acidic media. The gastric juice pH and extracellular pH change were measured separately in vitro using the Janus microparticles, which confirmed the validity of microgels for pH sensing. The microparticles exhibited good stability, reversibility, biocompatibility, and ideal semipermeability for avoiding protein contamination, and they have the potential to be implantable sensors to continuously monitor pH in vivo.

Urinary catheters

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Catheter - urine; Foley catheter; Indwelling catheter; Suprapubic catheters ... stones Blood infections ( septicemia ) Blood in the urine (hematuria) Kidney damage (usually only with long-term, indwelling ...

Silicon Integrated Dual-Mode Interferometer with Differential Outputs

Directory of Open Access Journals (Sweden)

Niklas Hoppe

2017-09-01

Full Text Available The dual-mode interferometer (DMI is an attractive alternative to Mach-Zehnder interferometers for sensor purposes, achieving sensitivities to refractive index changes close to state-of-the-art. Modern designs on silicon-on-insulator (SOI platforms offer thermally stable and compact devices with insertion losses of less than 1 dB and high extinction ratios. Compact arrays of multiple DMIs in parallel are easy to fabricate due to the simple structure of the DMI. In this work, the principle of operation of an integrated DMI with differential outputs is presented which allows the unambiguous phase shift detection with a single wavelength measurement, rather than using a wavelength sweep and evaluating the optical output power spectrum. Fluctuating optical input power or varying attenuation due to different analyte concentrations can be compensated by observing the sum of the optical powers at the differential outputs. DMIs with two differential single-mode outputs are fabricated in a 250 nm SOI platform, and corresponding measurements are shown to explain the principle of operation in detail. A comparison of DMIs with the conventional Mach-Zehnder interferometer using the same technology concludes this work.

Asymmetric dual-loop feedback to suppress spurious tones and reduce timing jitter in self-mode-locked quantum-dash lasers emitting at 155 μm

Science.gov (United States)

Asghar, Haroon; McInerney, John G.

2017-09-01

We demonstrate an asymmetric dual-loop feedback scheme to suppress external cavity side-modes induced in self-mode-locked quantum-dash lasers with conventional single and dual-loop feedback. In this letter, we achieved optimal suppression of spurious tones by optimizing the length of second delay time. We observed that asymmetric dual-loop feedback, with large (~8x) disparity in cavity lengths, eliminates all external-cavity side-modes and produces flat RF spectra close to the main peak with low timing jitter compared to single-loop feedback. Significant reduction in RF linewidth and reduced timing jitter was also observed as a function of increased second feedback delay time. The experimental results based on this feedback configuration validate predictions of recently published numerical simulations. This interesting asymmetric dual-loop feedback scheme provides simplest, efficient and cost effective stabilization of side-band free optoelectronic oscillators based on mode-locked lasers.

Real-time dual-comb spectroscopy with a free-running bidirectionally mode-locked fiber laser

Science.gov (United States)

Mehravar, S.; Norwood, R. A.; Peyghambarian, N.; Kieu, K.

2016-06-01

Dual-comb technique has enabled exciting applications in high resolution spectroscopy, precision distance measurements, and 3D imaging. Major advantages over traditional methods can be achieved with dual-comb technique. For example, dual-comb spectroscopy provides orders of magnitude improvement in acquisition speed over standard Fourier-transform spectroscopy while still preserving the high resolution capability. Wider adoption of the technique has, however, been hindered by the need for complex and expensive ultrafast laser systems. Here, we present a simple and robust dual-comb system that employs a free-running bidirectionally mode-locked fiber laser operating at telecommunication wavelength. Two femtosecond frequency combs (with a small difference in repetition rates) are generated from a single laser cavity to ensure mutual coherent properties and common noise cancellation. As the result, we have achieved real-time absorption spectroscopy measurements without the need for complex servo locking with accurate frequency referencing, and relatively high signal-to-noise ratio.

A Dual-Mode Microwave Applicator for Liver Tumor Thermotherapy

Science.gov (United States)

Reimann, Carolin; Schüßler, Martin; Jakoby, Rolf; Bazrafshan, Babak; Hübner, Frank; Vogl, Thomas

2018-03-01

The concept of a novel dual-mode microwave applicator for diagnosis and thermal ablation treatment of tumorous tissue is presented in this paper. This approach is realized by integrating a planar resonator array to, firstly, detect abnormalities by a relative dielectric analysis, and secondly, perform a highly localized thermal ablation. A further essential advantage is addressed by designing the applicator to be MRI compatible to provide a multimodal imaging procedure. Investigations for an appropriate frequency range lead to the use of much higher operating frequencies between 5 GHz and 10 GHz, providing a significantly lower power consumption for microwave ablation of only 20 W compared to commercial available applicators.

High-pitch dual-source CT angiography of the whole aorta without ECG synchronisation: Initial experience

International Nuclear Information System (INIS)

Beeres, Martin; Schell, Boris; Mastragelopoulos, Aristidis; Kerl, Josef Matthias; Gruber-Rouh, Tatjana; Lee, Clara; Siebenhandl, Petra; Bodelle, Boris; Zangos, Stephan; Vogl, Thomas J.; Jacobi, Volkmar; Bauer, Ralf W.; Herrmann, Eva

2012-01-01

To investigate the feasibility, image quality and radiation dose for high-pitch dual-source CT angiography (CTA) of the whole aorta without ECG synchronisation. Each group of 40 patients underwent CTA either on a 16-slice (group 1) or dual-source CT device with conventional single-source (group 2) or high-pitch mode with a pitch of 3.0 (group 3). The presence of motion or stair-step artefacts of the thoracic aorta was independently assessed by two readers. Subjective and objective scoring of motion and artefacts were significantly reduced in the high-pitch examination protocol (p < 0.05). The imaging length was not significantly different, but the imaging time was significantly (p < 0.001) shorter in the high-pitch group (12.2 vs. 7.4 vs. 1.7 s for groups 1, 2 and 3). The ascending aorta and the coronary ostia were reliably evaluable in all patients of group 3 without motion artefacts as well. High-pitch dual-source CT angiography of the whole aorta is feasible in unselected patients. As a significant advantage over regular pitch protocols, motion-free imaging of the aorta is possible without ECG synchronisation. Thus, this CT mode bears potential to become a standard CT protocol before trans-catheter aortic valve implantation (TAVI). (orig.)

In Vitro Urethra Model to Characterize The Frictional Properties of Urinary Catheters

DEFF Research Database (Denmark)

Røn, Troels; Lee, Seunghwan

2016-01-01

conformal sliding contacts with the catheter and high relevance to clinical catherization. With the proposed urethra model assembled in texture analyzer, the lubricity of catheters lubricated in different modes was tested. In comparison with conventional pin-on-disk tribometry, the coefficients of friction......, frictional properties of tubular devices such as catheters, endoscopes, and angioplasty balloons are particularly challenging to characterize because of non-standard shape and contact configuration. In this study, we propose that fabrication of in vitro urethra model with castable elastomers can provide...... of sliding contacts with the urethra model with unlubricated and lubricated catheters were determined. Impact of the improved bio-relevance of friction testing methods on the evaluation of various catheter materials and surface modification methods is discussed in detail....

Relationship between intracranial hypertension and cerebral blood flow after craniotomy in cases with traumatic acute subdural hematoma

International Nuclear Information System (INIS)

Karibe, Hiroshi; Onuma, Takehide; Kameyama, Motonobu; Nimura, Taro; Hirano, Takayuki; Kubota, Keiichi

2008-01-01

The purpose of this study is to investigate relationship between the duration of initial intracranial hypertension and postoperative cerebral blood flow (CBF) changes in cases with traumatic acute subdural hematoma (ASDH). Intracerebral pressure (ICP) was monitored using ICP catheter in 17 cases with unilateral traumatic ASDH. ICP monitoring was started before craniotomy, and was continued for 7 days. CBF was quantitatively measured at 7 days after craniotomy with 123 I-infetamine (IMP) single photon emission computed tomography (SPECT). Clinical outcome was evaluated using Glasgow Outcome Scale (GOS) at the time of discharge. Patients were divided into 2 groups by the duration of intracranial hypertension: patients who presented with intracranial hypertension (>25 mmHg) and received surgical decompression within 6 hours after deterioration (group A, n=9), and patients who presented with intracranial hypertension and received surgical decompression more than 6 hours after deterioration (group B, n=6). In group A, 7 of 9 patients demonstrated ipsilateral hemispheric hyperperfusion, and the clinical outcome was relatively favorable: Good Recovery (GR) 4 cases, Moderately Disabled (MD) 4 cases, and Severely Disabled (SD) 1 case. In group B, 5 of 6 patients demonstrated ipsilateral hemispheric hypoperfusion, and the clinical outcome was unfavorable: SD 4 cases, and Dead 2 cases. These results suggest that the duration of intracranial hypertension affects on postoperative CBF changes. Duration of intracranial hypertension may also affect on clinical outcome directly, or secondary by altering postoperative CBF changes in patients with traumatic ASDH. (author)

Control of intravascular catheters using an array of active steering coils.

Science.gov (United States)

Gudino, N; Heilman, J A; Derakhshan, J J; Sunshine, J L; Duerk, J L; Griswold, M A

2011-07-01

To extend the concept of deflecting the tip of a catheter with the magnetic force created in an MRI system through the use of an array of independently controllable steering coils located in the catheter tip, and to present methods for visualization of the catheter and/or surrounding areas while the catheter is deflected. An array of steering coils made of 42-gauge wire was built over a 2.5 Fr (0.83 mm) fiber braided microcatheter. Two of the coils were 70 turn axial coils separated by 1 cm, and the third was a 15-turn square side coil that was 2 x 4 mm2. Each coil was driven independently by a pulse width modulation (PWM) current source controlled by a microprocessor that received commands from a MATLAB routine that dynamically set current amplitude and direction for each coil. The catheter was immersed in a water phantom containing 1% Gd-DTPA that was placed at the isocenter of a 1.5 T MRI scanner. Deflections of the catheter tip were measured from image-based data obtained with a real-time radio frequency (RF) spoiled gradient echo sequence (GRE). The small local magnetic fields generated by the steering coils were exploited to generate a hyperintense signal at the catheter tip by using a modified GRE sequence that did not include slice-select rewinding gradients. Imaging and excitation modes were implemented by synchronizing the excitation of the steering coil array with the scanner by ensuring that no current was driven through the coils during the data acquisition window; this allowed visualization of the surrounding tissue while not affecting the desired catheter position. Deflections as large as 2.5 cm were measured when exciting the steering coils sequentially with a 100 mA maximum current per coil. When exciting a single axial coil, the deflection was half this value with 30% higher current. A hyperintense catheter tip useful for catheter tracking was obtained by imaging with the modified GRE sequence. Clear visualization of the areas surrounding the

Mini-cavity plasma core reactors for dual-mode space nuclear power/propulsion systems

International Nuclear Information System (INIS)

Chow, S.

1976-01-01

A mini-cavity plasma core reactor is investigated for potential use in a dual-mode space power and propulsion system. In the propulsive mode, hydrogen propellant is injected radially inward through the reactor solid regions and into the cavity. The propellant is heated by both solid driver fuel elements surrounding the cavity and uranium plasma before it is exhausted out the nozzle. The propellant only removes a fraction of the driver power, the remainder is transferred by a coolant fluid to a power conversion system, which incorporates a radiator for heat rejection. In the power generation mode, the plasma and propellant flows are shut off, and the driver elements supply thermal power to the power conversion system, which generates electricity for primary electric propulsion purposes

The contemporary management of intracranial atherosclerotic disease.

Science.gov (United States)

Leng, Xinyi; Wong, Ka Sing; Leung, Thomas W

2016-06-01

Intracranial atherosclerotic disease is the most common cause of cerebral vasculopathy and an important stroke etiology worldwide, with a higher prevalence in Asian, Hispanic and African ethnicities. Symptomatic intracranial atherosclerotic disease portends a recurrent stroke risk as high as 18% at one year. The key to secondary prevention is an understanding of the underlying stroke mechanism and aggressive control of conventional cardiovascular risks. Contemporary treatment includes antiplatelet therapy, optimal glycemic and blood pressure control, statin therapy and lifestyle modifications. For patients with high-grade (70-99%) symptomatic steno-occlusion, short-term dual antiplatelet therapy with aspirin and clopidogrel followed by life-long single antiplatelet therapy may reduce the recurrent risk. Current evidence does not advocate percutaneous transluminal angioplasty and stenting as an initial treatment. External counterpulsation, encephaloduroarteriosynangiosis and remote limb ischemic preconditioning are treatments under investigation. Future studies should aim at predicting patients prone to recurrence despite of medical therapies and testing the efficacy of emerging therapies.

Immediate Catheter Directed Thrombolysis for Thromboembolic Stroke During Carotid Endarterectomy

Directory of Open Access Journals (Sweden)

E. Fletcher

Full Text Available : Background: Carotid artery endarterectomy (CEA is a common procedure undertaken by vascular surgeons with over 5,000 procedures performed annually worldwide. Published rates of perioperative stroke range from 1.3% to 6.3%. Case report: A case is presented in which on-table intra-cranial angiography and catheter directed thrombolysis were used for a thromboembolic occlusion of the distal internal carotid artery (ICA and proximal middle cerebral artery (MCA. An 83-year-old lady developed a dense right hemiparesis while undergoing a CEA under local anaesthetic (LA. Immediate re-exploration of the endarterectomy did not reveal technical error. Intraoperative duplex scanning of the internal carotid artery revealed no detectable diastolic flow. On-table angiogram showed complete occlusion of the distal ICA and proximal MCA. Catheter directed administration of TPA was undertaken. The entire ICA and MCA were completely clear on a completion angiogram. The patient made a full neurological recovery. Discussion and conclusion: Prompt diagnosis and treatment with intraoperative catheter directed thrombolysis can resolve thromboembolic occlusion of the ICA/MCA. It is argued that performing CEA under LA is useful for immediate recognition of perioperative stroke. Furthermore, the advantage is highlighted of vascular surgeons having both the resources and skillset to perform on-table angiography and thrombolysis. Keywords: Carotid endarterectomy, Stroke, Thrombolysis, Thromboembolus, Local anaesthetic

Central venous catheters: detection of catheter complications and therapeutical options

International Nuclear Information System (INIS)

Gebauer, B.; Beck, A.; Wagner, H.J.; Vivantes-Kliniken, Hellersdorf und Prenzlauer Berg

2008-01-01

For modern medicine central venous catheters play an important role for diagnostic and therapeutic options. Catheter implantation, complication detection and therapy of catheter complications are an increasing demand for the radiologist. The review article provides an overview of different catheter types, their indications, advantages and disadvantages. Catheter malpositions are usually detectable in conventional X-ray. Most malpositions are correctable using interventional-radiological techniques. In addition therapeutical options for thrombotic complications (venous thrombosis, catheter occlusion, fibrin sheath) are discussed. In case of an infectious catheter complication, usually a catheter extraction and re-implantation is necessary

Effect of universal adhesive etching modes on bond strength to dual-polymerizing composite resins.

Science.gov (United States)

Michaud, Pierre-Luc; Brown, Matthew

2018-04-01

Information is lacking as to the effect on bond strength of the etching modes of universal adhesives when they are used to bond dual-polymerizing composite resins to dentin. The purpose of this in vitro study was to investigate the bonding of dual-polymerizing foundation composite resins to dentin when universal bonding agents are used in self-etch or etch-and-rinse modes. Sixty caries-free, extracted third molar teeth were sectioned transversely in the apical third of the crown and allocated to 12 groups (n=5). Three different bonding agents (Scotchbond Universal, OptiBond XTR, All-Bond Universal) were used to bond 2 different dual-polymerizing composite resins (CompCore AF or CoreFlo DC) to dentin, using 2 different etching approaches (etch-and-rinse or self-etch). The specimens were sectioned into sticks (1×1×8 mm) with a precision saw. The bond strength of the specimens was tested under microtensile force at a crosshead speed of 0.5 mm/min. The data were analyzed using a 3-way ANOVA, a Games-Howell post hoc comparisons model, and Student t tests with Bonferroni corrections (α=.05). In the overall model, the composite resin used had no effect on bond strength (P=.830). The etching protocol by itself also did not have a significant effect (P=.059), although a trend was present. The bonding agent, however, did have an effect (Pcomposite resins to dentin, no single etching protocol is better than another. Depending on which bonding agent is being used, one etching mode may perform better. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Catheter Angiography

Medline Plus

Full Text Available ... Z Catheter Angiography Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material ... vessels in the body. Angiography is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging ( ...

Highly Luminescent Dual Mode Polymeric Nanofiber-Based Flexible Mat for White Security Paper and Encrypted Nanotaggant Applications.

Science.gov (United States)

Gangwar, Amit Kumar; Gupta, Ashish; Kedawat, Garima; Kumar, Pawan; Singh, Bhanu Pratap; Singh, Nidhi; Srivastava, Avanish K; Dhakate, Sanjay R; Gupta, Bipin Kumar

2018-05-23

Increasing counterfeiting of important data, currency, stamp papers, branded products etc., has become a major security threat which could lead to serious damage to the global economy. Consequences of such damage are compelling for researchers to develop new high-end security features to address full-proof solutions. Herein, we report a dual mode flexible highly luminescent white security paper and nanotaggants composed of nanophosphors incorporated in polymer matrix to form a nanofiber-based mat for anti-counterfeiting applications. The dual mode nanofibers are fabricated by electrospinning technique by admixing the composite of NaYF 4 :Eu 3+ @NaYF 4 :Yb 3+ , Er 3+ nanophosphors in the polyvinyl alcohol solution. This flexible polymer mat derived from nanofibers appears white in daylight, while emitting strong red (NaYF 4 :Eu 3+ ) and green (NaYF 4 :Yb 3+ , Er 3+ ) colors at excitation wavelengths of 254 nm and 980 nm, respectively. These luminescent nanofibers can also be encrypted as a new class of nanotaggants to protect confidential documents. These obtained results suggest that highly luminescent dual mode polymeric nanofiber-based flexible white security paper and nanotaggants could offer next-generation high-end unique security features against counterfeiting. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation on utilization of biogas and Karanja oil biodiesel in dual fuel mode in a single cylinder DI diesel engine

Energy Technology Data Exchange (ETDEWEB)

Prasanna Pattanaik, Bhabani; Nayak, Chandrakanta [Department of Mechanical Eng., Gandhi Institute for Technological Advancement, Madanpur, Bhubaneswar - 752054, Odisha (India); Kumar Nanda, Basanta [Department of Mechanical Eng., Maharaja Institute of Technology, Bhubaneswar, Odisha (India)

2013-07-01

In this work, experiments were performed on a single cylinder DI diesel engine by using bio-gas as a primary fuel and Karanja oil biodiesel and diesel oil as secondary fuels in dual fuel operation. The experiments were performed to measure performance parameters i.e. (brake specific fuel consumption, brake thermal efficiency and exhaust gas temperature) and emission parameters such as carbon monoxide, carbon dioxide, nitrogen oxide unburned hydro carbon and smoke etc. at different load conditions. For the dual-fuel system, the intake system of the test engine was modified to convert into biogas and biodiesel of a dual-fueled combustion engine. Biogas was injected during the intake process by gas injectors. The study showed that, the engine performance parameters like BP, BTE and EGT gradually increase with increase in engine load for all test conditions using both pilot fuels diesel and KOBD. However, the BSFC of the engine showed decreasing slope with increase in engine load for all test conditions. Above 40% engine load the BSFC values for all test fuels are very close to each other. The engine emission analysis showed that the CO2, CO and NOx emissions increase with increase in engine load for both single and dual fuel mode operation using both pilot fuels. The NOx concentration of exhaust gases in dual fuel mode is superior than that of single mode.

Study on using acetylene in dual fuel mode with exhaust gas recirculation

International Nuclear Information System (INIS)

Lakshmanan, T.; Nagarajan, G.

2011-01-01

Interest in employing gaseous fuels to internal combustion (IC) engines whether for stationary or mobile automotive applications has gained importance because of the economical, sustainable and environmental technical features associated with their usage. However, the incidence of preignition and knock remains a significant barrier in achieving their optimum performance potential. With the advent of latest technologies, the above barriers are eliminated. One such technique is timed manifold injection (TMI) of the gaseous fuel, which is controlled electronically to precisely monitor the induction of fuel to overcome the preignition problem in the intake. In the present investigation, acetylene was injected in the intake manifold in a single cylinder diesel engine, with a gas flow rate of 240 g/h, start of injection time is 10 o aTDC and 90 o CA (9.9 ms) duration, operated in dual fuel mode. In order to decrease the NOx emissions from acetylene-diesel engine, cooled EGR was employed. The cylinder pressure, brake thermal efficiency and emissions such as NOx, smoke, CO, HC, CO 2 and exhaust gas temperature were studied. Dual fuel operation with acetylene induction coupled with cooled EGR results in lowered NOx emissions and improved part load performance. -- Highlights: → Acetylene was tried in SI engines, but due to backfire further research was hindered as an alternative fuel. → But it is not tried in CI engine. Timed manifold injection was tried in diesel engine in the present work to combat backfire. → Author was successful in running the diesel engine in dual fuel mode. → 21% maximum diesel replacement was achieved. Author is confident that acetylene will be commercialised as a fuel for diesel engine in future.

Nonlinear defect localized modes and composite gray and anti-gray solitons in one-dimensional waveguide arrays with dual-flip defects

Science.gov (United States)

Liu, Yan; Guan, Yefeng; Li, Hai; Luo, Zhihuan; Mai, Zhijie

2017-08-01

We study families of stationary nonlinear localized modes and composite gray and anti-gray solitons in a one-dimensional linear waveguide array with dual phase-flip nonlinear point defects. Unstaggered fundamental and dipole bright modes are studied when the defect nonlinearity is self-focusing. For the fundamental modes, symmetric and asymmetric nonlinear modes are found. Their stable areas are studied using different defect coefficients and their total power. For the nonlinear dipole modes, the stability conditions of this type of mode are also identified by different defect coefficients and the total power. When the defect nonlinearity is replaced by the self-defocusing one, staggered fundamental and dipole bright modes are created. Finally, if we replace the linear waveguide with a full nonlinear waveguide, a new type of gray and anti-gray solitons, which are constructed by a kink and anti-kink pair, can be supported by such dual phase-flip defects. In contrast to the usual gray and anti-gray solitons formed by a single kink, their backgrounds on either side of the gray hole or bright hump have the same phase.

Implantable electrolyte conductance-based pressure sensing catheter, II. Device construction and testing.

Science.gov (United States)

Tan, Robert; Benharash, Peyman; Schulam, Peter; Schmidt, Jacob J

2013-12-01

Direct measurements of arterial blood pressure most commonly use bulky external instrumentation containing a pressure transducer connected to an ex vivo fluid-filled arterial line, which is subject to several sensing artifacts. In situ blood pressure sensors, typically solid state piezoresistive, capacitive, and interferometric sensors, are unaffected by these artifacts, but can be expensive to produce and miniaturize. We have developed an alternative approach to blood pressure measurement based on deformation of an elastic tube filled with electrolyte solution. Simple measurement of the electrical conductance of this solution as the tube dimensions change allows determination of the external pressure. The sensor is made from inexpensive materials and its miniaturization is straightforward. In vitro static testing of initial sensor prototypes mounted on a catheter tip showed a linear response with applied pressure and a resolution of 1 mmHg. In vivo sensing followed catheterization of the sensor into the femoral artery of a porcine model through a 7F catheter port. The sensor performed comparably to a commercial pressure transducer also connected to the catheter port. Due to its scalability and cost, this sensor has the potential for use in a range of pressure sensing applications, such as measurement of intracranial, spinal, or interstitial pressures.

Urinary catheter - infants

Science.gov (United States)

Bladder catheter - infants; Foley catheter - infants; Urinary catheter - neonatal ... A urinary catheter is a small, soft tube placed in the bladder. This article addresses urinary catheters in babies. WHY IS ...

A Stent-Retrieving into an Aspiration Catheter with Proximal Balloon (ASAP) Technique: A Technique of Mechanical Thrombectomy.

Science.gov (United States)

Goto, Shunsaku; Ohshima, Tomotaka; Ishikawa, Kojiro; Yamamoto, Taiki; Shimato, Shinji; Nishizawa, Toshihisa; Kato, Kyozo

2018-01-01

The best technique for the first attempt at mechanical thrombectomy for acute ischemic stroke is a still matter of debate. In this study, we evaluate the efficacy of a stent-retrieving into an aspiration catheter with proximal balloon (ASAP) technique that uses a series of thrombus extraction by withdrawing the stent retriever into the aspiration catheter and continuous aspiration from the aspiration catheter at the first attempt. We performed a retrospective analysis of 42 consecutive patients with acute ischemic stroke caused by occlusions in the anterior circulation who were treated with the ASAP technique at our institution. Preoperative patient characteristic, including age, thrombus location, Alberta Stroke Program Early CT Score, National Institutions of Health Stroke Scale, and time from onset to puncture; postoperative Thrombolysis in Cerebral Infarction score; modified Rankin Scale score after 3 months; time from puncture to recanalization; the number of passes to achieve recanalization; and procedural complications, including intracranial hemorrhage, embolization to new territory, and distal embolization, were assessed. A Thrombolysis in Cerebral Infarction score of 2B or 3 was achieved in 40/42 patients (95.2%). Average time from puncture to the final recanalization was 21.5 minutes. Recanalization was achieved in a single attempt in 31 patients (77.5%). Embolization to new territory was observed in only 2 patients (4.8%); no patient developed distal embolization or intracranial hemorrhage including asymptomatic subarachnoid hemorrhage. Thirty-two patients (76.2%) achieved modified Rankin Scale scores of 0-2 at 3 months postoperatively. Our ASAP technique showed fast recanalization, minimal complications, and good clinical outcomes in this case series. Copyright © 2017 Elsevier Inc. All rights reserved.

Optical frequency comb generation based on the dual-mode square microlaser and a nonlinear fiber loop

Science.gov (United States)

Weng, Hai-Zhong; Han, Jun-Yuan; Li, Qing; Yang, Yue-De; Xiao, Jin-Long; Qin, Guan-Shi; Huang, Yong-Zhen

2018-05-01

A novel approach using a dual-mode square microlaser as the pump source is demonstrated to produce wideband optical frequency comb (OFC). The enhanced nonlinear frequency conversion processes are accomplished in a nonlinear fiber loop, which can reduce the stimulated Brillouin scattering threshold and then generate a dual-mode Brillouin laser with improved optical signal-to-noise ratio. An OFC with 130 nm bandwidth and 76 GHz repetition rate is successfully generated under the four-wave mixing, and the number of the comb lines is enhanced by 26 times compared with the system without fiber loop. In addition, the repetition rate of the comb can be adjusted by changing the injection current of the microlaser. The pulse width of the comb spectrum is also compressed from 3 to 1 ps with an extra amplification-nonlinear process.

Melanin-originated carbonaceous dots for triple negative breast cancer diagnosis by fluorescence and photoacoustic dual-mode imaging.

Science.gov (United States)

Xiao, Wei; Li, Yuan; Hu, Chuan; Huang, Yuan; He, Qin; Gao, Huile

2017-07-01

Carbonaceous dots exhibit increasing applications in diagnosis and drug delivery due to excellent photostability and biocompatibility properties. However, relative short excitation and emission of melanin carbonaceous dots (MCDs) limit the applicability in fluorescence bioimaging. Furthermore, the generally poor spatial resolution of fluorescence imaging limits potential in vivo applications. Due to a variety of beneficial properties, in this study, MCDs were prepared exhibiting great potential in fluorescence and photoacoustic dual-mode bioimaging. The MCDs exhibited a long excitation peak at 615nm and emission peak at 650nm, further highlighting the applicability in fluorescence imaging, while the absorbance peak at 633nm renders MCDs suitable for photoacoustic imaging. In vivo, the photoacoustic signal of MCDs was linearly correlated with the concentration of MCDs. Moreover, the MCDs were shown to be taken up into triple negative breast cancer cell line 4T1 in both a time- and concentration-dependent manner. In vivo fluorescence and photoacoustic imaging of subcutaneous 4T1 tumor demonstrated that MCDs could passively target triple negative breast cancer tissue by enhanced permeability and retention effects and may therefore be used for tumor dual-mode imaging. Furthermore, fluorescence distribution in tissue slices suggested that MCDs may distribute in 4T1 tumor with high efficacy. In conclusion, the MCDs studied offer potential application in fluorescence and photoacoustic dual-mode imaging. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of curing modes of dual-curing core systems on microtensile bond strength to dentin and formation of an acid-base resistant zone.

Science.gov (United States)

Li, Na; Takagaki, Tomohiro; Sadr, Alireza; Waidyasekera, Kanchana; Ikeda, Masaomi; Chen, Jihua; Nikaido, Toru; Tagami, Junji

2011-12-01

To evaluate the microtensile bond strength (μTBS) and acid-base resistant zone (ABRZ) of two dualcuring core systems to dentin using four curing modes. Sixty-four caries-free human molars were randomly divided into two groups according to two dual-curing resin core systems: (1) Clearfil DC Core Automix; (2) Estelite Core Quick. For each core system, four different curing modes were applied to the adhesive and core resin: (1) dual-cured and dual-cured (DD); (2) chemically cured and dual-cured (CD); (3) dual-cured and chemically cured (DC); (4) chemically cured and chemically cured (CC). The specimens were sectioned into sticks (n = 20 for each group) for the microtensile bond test. μTBS data were analyzed using two-way ANOVA and the Dunnett T3 test. Failure patterns were examined with scanning electron microscopy (SEM) to determine the proportion of each mode. Dentin sandwiches were produced and subjected to an acid-base challenge. After argon-ion etching, the ultrastructure of ABRZ was observed using SEM. For Clearfil DC Core Automix, the μTBS values in MPa were as follows: DD: 29.1 ± 5.4, CD: 21.6 ± 5.6, DC: 17.9 ± 2.8, CC: 11.5 ± 3.2. For Estelite Core Quick, they were: DD: 48.9 ±5.7, CD: 20.5 ± 4.7, DC: 41.4 ± 8.3, CC: 19.1 ± 6.0. The bond strength was affected by both material and curing mode, and the interaction of the two factors was significant (p < 0.001). Within both systems, there were significant differences among groups, and the DD group showed the highest μTBS (p < 0.05). ABRZ morphology was not affected by curing mode, but it was highly adhesive-material dependent. The curing mode of dual-curing core systems affects bond strength to dentin, but has no significant effect on the formation of ABRZ.

Traumatic epistaxis: Skull base defects, intracranial complications and neurosurgical considerations.

Science.gov (United States)

Veeravagu, Anand; Joseph, Richard; Jiang, Bowen; Lober, Robert M; Ludwig, Cassie; Torres, Roland; Singh, Harminder

2013-01-01

Endonasal procedures may be necessary during management of craniofacial trauma. When a skull base fracture is present, these procedures carry a high risk of violating the cranial vault and causing brain injury or central nervous system infection. A 52-year-old bicyclist was hit by an automobile at high speed. He sustained extensive maxillofacial fractures, including frontal and sphenoid sinus fractures (Fig. 1). He presented to the emergency room with brisk nasopharyngeal hemorrhage, and was intubated for airway protection. He underwent emergent stabilization of his nasal epistaxis by placement of a Foley catheter in his left nare and tamponade with the Foley balloon. A six-vessel angiogram showed no evidence of arterial dissection or laceration. Imaging revealed inadvertent insertion of the Foley catheter and deployment of the balloon in the frontal lobe (Fig. 2). The balloon was subsequently deflated and the Foley catheter removed. The patient underwent bifrontal craniotomy for dural repair of CSF leak. He also had placement of a ventriculoperitoneal shunt for development of post-traumatic hydrocephalus. Although the hospital course was a prolonged one, he did make a good neurological recovery. The authors review the literature involving violation of the intracranial compartment with medical devices in the settings of craniofacial trauma. Caution should be exercised while performing any endonasal procedure in the settings of trauma where disruption of the anterior cranial base is possible. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

A dual-mode operation overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic mode output

Science.gov (United States)

Bai, Zhen; Zhang, Jun; Zhong, Huihuang

2016-04-01

An overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic (TEM) mode output is designed and presented, by using a kind of coaxial slow wave structure (SWS) with large transversal dimension and small distance between inner and outer conductors. The generator works in dual-mode operation mechanism. The electron beam synchronously interacts with 7π/8 mode of quasi-TEM, at the meanwhile exchanges energy with 3π/8 mode of TM01. The existence of TM01 mode, which is traveling wave, not only increases the beam-wave interaction efficiency but also improves the extraction efficiency. The large transversal dimension of coaxial SWS makes its power capacity higher than that of other reported millimeter-wave devices and the small distance between inner and outer conductors allows only two azimuthally symmetric modes to coexist. The converter after the SWS guarantees the mode purity of output power. Particle-in-cell simulation shows that when the diode voltage is 400 kV and beam current is 3.8 kA, the generation of microwave at 32.26 GHz with an output power of 611 MW and a conversion efficiency of 40% is obtained. The power percentage carried by TEM mode reaches 99.7% in the output power.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

Science.gov (United States)

Yuceler, Zeyneb; Kantarci, Mecit; Yuce, Ihsan; Kizrak, Yesim; Bayraktutan, Ummugulsum; Ogul, Hayri; Kiris, Adem; Celik, Omer; Pirimoglu, Berhan; Genc, Berhan; Gundogdu, Fuat

2014-01-01

Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.

Catheter Angiography

Medline Plus

Full Text Available ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. An example ...

Catheter Angiography

Medline Plus

Full Text Available ... few millimeters) in the skin where the catheter can be inserted into an artery. The catheter is ... need for surgery. If surgery remains necessary, it can be performed more accurately. Catheter angiography presents a ...

Catheter Angiography

Medline Plus

Full Text Available ... resonance imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an ... The catheter used in angiography is a long plastic tube about as thick as a strand of ...

Vibrational correlation between conjugated carbonyl and diazo modes studied by single- and dual-frequency two-dimensional infrared spectroscopy

Science.gov (United States)

Maekawa, Hiroaki; Sul, Soohwan; Ge, Nien-Hui

2013-08-01

We have applied infrared three-pulse photon echo and single- and dual-frequency 2D IR spectroscopy to the ester Cdbnd O and diazo Ndbnd N stretching modes in ethyl diazoacetate (EDA), and investigated their vibrational frequency fluctuations and correlation. The two modes exhibit different vibrational dynamics and 2D lineshape, which are well simulated by frequency-frequency correlation functions (FFCFs) with two decaying components. Although the FT IR spectrum shows a single Cdbnd O band, absolute magnitude 2D IR nonrephasing spectrum displays spectral signatures supporting the presence of cis and trans conformations. The cross-peak inclined toward the anti-diagonal in the dual-frequency 2D IR spectrum, indicating that the frequency fluctuations of the two modes are anticorrelated. This behavior is attributed to anticorrelated change in the bond orders when solvent and structural fluctuations causes EDA to adopt a different mixture of the two dominant resonance structures. The effects of cross FFCF on the cross-peak line shape are discussed.

HIFU Monitoring and Control with Dual-Mode Ultrasound Arrays

Science.gov (United States)

Casper, Andrew Jacob

The biological effects of high-intensity focused ultrasound (HIFU) have been known and studied for decades. HIFU has been shown capable of treating a wide variety of diseases and disorders. However, despite its demonstrated potential, HIFU has been slow to gain clinical acceptance. This is due, in part, to the difficulty associated with robustly monitoring and controlling the delivery of the HIFU energy. The non-invasive nature of the surgery makes the assessment of treatment progression difficult, leading to long treatment times and a significant risk of under treatment. This thesis research develops new techniques and systems for robustly monitoring HIFU therapies for the safe and efficacious delivery of the intended treatment. Systems and algorithms were developed for the two most common modes of HIFU delivery systems: single-element and phased array applicators. Delivering HIFU with a single element transducer is a widely used technique in HIFU therapies. The simplicity of a single element offers many benefits in terms of cost and overall system complexity. Typical monitoring schemes rely on an external device (e.g. diagnostic ultrasound or MRI) to assess the progression of therapy. The research presented in this thesis explores using the same element to both deliver and monitor the HIFU therapy. The use of a dual-mode ultrasound transducer (DMUT) required the development of an FPGA based single-channel arbitrary waveform generator and high-speed data acquisition unit. Data collected from initial uncontrolled ablations led to the development of monitoring and control algorithms which were implemented directly on the FPGA. Close integration between the data acquisition and arbitrary waveform units allowed for fast, low latency control over the ablation process. Results are presented that demonstrate control of HIFU therapies over a broad range of intensities and in multiple in vitro tissues. The second area of investigation expands the DMUT research to an

Intracranial cerebral artery stenosis with associated coronary artery and extracranial carotid artery stenosis in Turkish patients

Energy Technology Data Exchange (ETDEWEB)

Alkan, Ozlem [Department of Radiology, Baskent University, Faculty of Medicine, Ankara (Turkey)], E-mail: yalinozlem@hotmail.com; Kizilkilic, Osman; Yildirim, Tulin [Department of Radiology, Baskent University, Faculty of Medicine, Ankara (Turkey); Atalay, Hakan [Department of Cardiovascular Surgery, Baskent University, Faculty of Medicine, Ankara (Turkey)

2009-09-15

Purpose: Although it has been demonstrated that there is a high prevalence of extracranial carotid artery stenosis (ECAS) in patients with severe coronary artery disease, intracranial cerebral artery stenosis (ICAS) is rarely mentioned. We evaluated the prevalence of ICAS in patients with ECAS having elective coronary artery bypass grafting (CABG) surgery to determine the relations between ICAS, ECAS and atherosclerotic risk factors. Methods: We retrospectively reviewed the digital subtraction angiography findings of 183 patients with ECAS {>=} 50% preparing for CABG surgery. The analyses focused on the intracranial or extracranial location and degree of the stenosis. The degree of extracranial stenoses were categorized as normal, <50%, 50-69%, 70-89%, and 90-99% stenosis and occluded. The degree of intracranial stenosis was classified as normal or {<=}25%, 25-49%, and {>=}50% stenosis and occluded. Traditional atherosclerotic risk factors were recorded. Results: ECAS < 70% in 42 patients and ECAS {>=} 70% in 141 patients. ICAS was found in 51 patients and ICAS {>=} 50% in 30 patients. Regarding risk factors, we found hypertension in 135 patients, diabetes mellitus in 91 patients, hyperlipidemia in 84 patients, and smoking in 81 patients. No risk factor was significant predictors of intracranial atherosclerosis. The severity of ICAS was not significantly associated with that of the ECAS. Conclusions: We found ICAS in 27.8% of the patients with ECAS > 50% on digital subtraction angiography preparing for CABG. Therefore a complete evaluation of the neck vessels with magnetic resonance or catheter angiography seems to be indicated as well as intracranial circulation for the risk assessment of CABG.

Dual mode operation, highly selective nanohole array-based plasmonic colour filters

Science.gov (United States)

Fouladi Mahani, Fatemeh; Mokhtari, Arash; Mehran, Mahdiyeh

2017-09-01

Taking advantage of nanostructured metal films as plasmonic colour filters (PCFs) has been evolved remarkably as an alternative to the conventional technologies of chemical colour filtering. However, most of the proposed PCFs depict a poor colour purity focusing on generating either the additive or subtractive colours. In this paper, we present dual mode operation PCFs employing an opaque aluminium film patterned with sub-wavelength holes. Subtractive colours like cyan, magenta, and yellow are the results of reflection mode of these filters yielding optical efficiencies as high as 70%-80% and full width at half maximum of the stop-bands up to 40-50 nm. The colour selectivity of the transmission mode for the additive colours is also significant due to their enhanced performance through the utilization of a relatively thick aluminium film in contact with a modified dielectric environment. These filters provide a simple design with one-step lithography in addition to compatibility with the conventional CMOS processes. Moreover, they are polarization insensitive due to their symmetric geometry. A complete palette of pure subtractive and additive colours has been realized with potential applications, such as multispectral imaging, CMOS image sensors, displays, and colour printing.

Catheter Angiography

Medline Plus

Full Text Available ... using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a thin plastic ... called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a catheter makes it ...

Formation of multifunctional Fe3O4/Au composite nanoparticles for dual-mode MR/CT imaging applications

International Nuclear Information System (INIS)

Hu Yong; Li Jing-Chao; Shen Ming-Wu; Shi Xiang-Yang

2014-01-01

Recent advances with iron oxide/gold (Fe 3 O 4 /Au) composite nanoparticles (CNPs) in dual-modality magnetic resonance (MR) and computed tomography (CT) imaging applications are reviewed. The synthesis and assembly of “dumbbelllike” and “core/shell” Fe 3 O 4 /Au CNPs is introduced. Potential applications of some developed Fe 3 O 4 /Au CNPs as contrast agents for dual-mode MR/CT imaging applications are described in detail. (topical review - magnetism, magnetic materials, and interdisciplinary research)

Catheter indwell time and phlebitis development during peripheral intravenous catheter administration.

Science.gov (United States)

Pasalioglu, Kadriye Burcu; Kaya, Hatice

2014-07-01

Intravenous catheters have been indispensable tools of modern medicine. Although intravenous applications can be used for a multitude of purposes, these applications may cause complications, some of which have serious effects. Of these complications, the most commonly observed is phlebitis. This study was conducted to determine the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. This study determined the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. The study included a total of 103 individuals who were administered 439 catheters and satisfied the study enrollment criteria at one infectious diseases clinic in Istanbul/Turkey. Data were compiled from Patient Information Forms, Peripheral Intravenous Catheter and Therapy Information Forms, reported grades based on the Visual Infusion Phlebitis Assessment Scale, and Peripheral Intravenous Catheter Nurse Observation Forms. The data were analyzed using SPSS. Results : The mean patient age was 53.75±15.54 (standard deviation) years, and 59.2% of the study participants were men. Phlebitis was detected in 41.2% of peripheral intravenous catheters, and the rate decreased with increased catheter indwell time. Analyses showed that catheter indwell time, antibiotic usage, sex, and catheterization sites were significantly associated with development of phlebitis. The results of this study show that catheters can be used for longer periods of time when administered under optimal conditions and with appropriate surveillance.

Saline-enhanced hepatic radiofrequency ablation using a perfused-cooled electrode: comparison of dual probe bipolar mode with monopolar and single probe bipolar modes

International Nuclear Information System (INIS)

Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Lee, Jae Young; Kim, Dae Jin; Lee, Min Woo; Cho, Gyung Goo; Han, Chang Jin; Choi, Byung Ihn

2004-01-01

To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis. RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups. The mean current values were higher for monopolar mode (group A) than for the bipolar modes (group B and C): 1550 ± 25 mA in group A, 764 ±189 mA in group B and 819 ± 98 mA in group C(ρ 3 in group A, 23.7 ±3.8 cm 3 in group B, and 34.2 ± 5.1 cm 3 in group C(ρ 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70 ± 18 .deg. C in group A, 59 ± 23 .deg. C in group B and 96 ± 16 .deg. C in group C (ρ < 0.05). Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA

A Plasma Based OES-CRDS Dual-mode Portable Spectrometer for Trace Element Detection: Emission and Ringdown Measurements of Mercury

Science.gov (United States)

Sahay, Peeyush; Scherrer, Susan; Wang, Chuji

2012-10-01

Design and development of a plasma based optical emission spectroscopy-cavity ringdown spectroscopy (OES-CRDS) dual-mode portable spectrometer for in situ monitoring of trace elements is described. A microwave plasma torch (MPT) has been utilized, which serves both as an atomization and excitation source for the two modes, viz. OES and CRDS, of the spectrometer. Operation of both modes of the instrument is demonstrated with initial measurements of elemental mercury (Hg). A detection limit of 44 ng mL-1 for Hg at 253.65 nm was determined with the emission mode of the instrument. Severe radiation trapping of 253.65 nm line hampers the measurement of Hg in higher concentration region (> 50 μg ml-1). Therefore, a different wavelength, 365.01 nm, is suggested to measure Hg in that region. Ringdown measurements of the metastable 6s6p ^3P0 state of Hg in the plasma using a 404.65 nm palm size diode laser was conducted to demonstrate the CRDS mode of the instrument. Along with being portable, dual-mode, and self-calibrated, the instrument is capable of measuring a wide range of concentration ranging from sub ng mL-1 to several μg ml-1 for a number of elements.

A dual-mode operation overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic mode output

Energy Technology Data Exchange (ETDEWEB)

Bai, Zhen; Zhang, Jun, E-mail: zhangjun@nudt.edu.cn; Zhong, Huihuang [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2016-04-15

An overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic (TEM) mode output is designed and presented, by using a kind of coaxial slow wave structure (SWS) with large transversal dimension and small distance between inner and outer conductors. The generator works in dual-mode operation mechanism. The electron beam synchronously interacts with 7π/8 mode of quasi-TEM, at the meanwhile exchanges energy with 3π/8 mode of TM{sub 01}. The existence of TM{sub 01} mode, which is traveling wave, not only increases the beam-wave interaction efficiency but also improves the extraction efficiency. The large transversal dimension of coaxial SWS makes its power capacity higher than that of other reported millimeter-wave devices and the small distance between inner and outer conductors allows only two azimuthally symmetric modes to coexist. The converter after the SWS guarantees the mode purity of output power. Particle-in-cell simulation shows that when the diode voltage is 400 kV and beam current is 3.8 kA, the generation of microwave at 32.26 GHz with an output power of 611 MW and a conversion efficiency of 40% is obtained. The power percentage carried by TEM mode reaches 99.7% in the output power.

Infraclavicular versus axillary nerve catheters: A retrospective comparison of early catheter failure rate.

Science.gov (United States)

Quast, Michaela B; Sviggum, Hans P; Hanson, Andrew C; Stoike, David E; Martin, David P; Niesen, Adam D

2018-05-01

Continuous brachial plexus catheters are often used to decrease pain following elbow surgery. This investigation aimed to assess the rate of early failure of infraclavicular (IC) and axillary (AX) nerve catheters following elbow surgery. Retrospective study. Postoperative recovery unit and inpatient hospital floor. 328 patients who received IC or AX nerve catheters and underwent elbow surgery were identified by retrospective query of our institution's database. Data collected included unplanned catheter dislodgement, catheter replacement rate, postoperative pain scores, and opioid administration on postoperative day 1. Catheter failure was defined as unplanned dislodging within 24 h of placement or requirement for catheter replacement and evaluated using a covariate adjusted model. 119 IC catheters and 209 AX catheters were evaluated. There were 8 (6.7%) failed IC catheters versus 13 (6.2%) failed AX catheters. After adjusting for age, BMI, and gender there was no difference in catheter failure rate between IC and AX nerve catheters (p = 0.449). These results suggest that IC and AX nerve catheters do not differ in the rate of early catheter failure, despite differences in anatomic location and catheter placement techniques. Both techniques provided effective postoperative analgesia with median pain scores < 3/10 for patients following elbow surgery. Reasons other than rate of early catheter failure should dictate which approach is performed. Copyright © 2018. Published by Elsevier Inc.

Catheter Angiography

Medline Plus

Full Text Available ... lessen your anxiety during the procedure. The area of the groin or arm where the catheter will be inserted is shaved, ... contrast material is injected through the catheter and reaches the blood vessels being studied, several sets of x-rays are taken. Then the catheter is ...

Development of an Infection-Responsive Fluorescent Sensor for the Early Detection of Urinary Catheter Blockage.

Science.gov (United States)

Milo, Scarlet; Acosta, Florianne B; Hathaway, Hollie J; Wallace, Laura A; Thet, Naing T; Jenkins, A Toby A

2018-03-23

Formation of crystalline biofilms following infection by Proteus mirabilis can lead to encrustation and blockage of long-term indwelling catheters, with serious clinical consequences. We describe a simple sensor, placed within the catheter drainage bag, to alert of impending blockage via a urinary color change. The pH-responsive sensor is a dual-layered polymeric "lozenge", able to release the self-quenching dye 5(6)-carboxyfluorescein in response to the alkaline urine generated by the expression of bacterial urease. Sensor performance was evaluated within a laboratory model of the catheterized urinary tract, infected with both urease positive and negative bacterial strains under conditions of established infection, achieving an average "early warning" of catheter blockage of 14.5 h. Signaling only occurred following infection with urease positive bacteria. Translation of these sensors into a clinical environment would allow appropriate intervention before the occurrence of catheter blockage, a problem for which there is currently no effective control method.

Prognostic factors in childhood intracranial neoplasms

International Nuclear Information System (INIS)

Ampil, F.L.

1987-01-01

Thirty-six cases of primary intracranial neoplasm in children (over 1 year but under 13 years of age) seen at the university medical center between 1951 and 1982 were reviewed because of concern as to the results and after-effects of applied therapy. The overall 5-year actuarial survival rate was 17 %. Several factors of possible prognostic relevance, such as patient's age, intracranial location of the tumor, application or nonapplication of therapy, single or multiple modes of therapy, and extent of surgery, were analyzed. Completeness of surgical removal of the tumor proved to be the only statistically significant factor that correlated with survival. There was only one recorded case of severe learning disability and abnormal neuropsychologic development among the 12 living patients. The influence of patient's age (and technical factors) at the time of irradiation in correlation with the child's subsequent posttreatment functional performance, as reported in the literature, is reviewed. (author)

Experimental study on combustion modes and thrust performance of a staged-combustor of the scramjet with dual-strut

Science.gov (United States)

Yang, Qingchun; Chetehouna, Khaled; Gascoin, Nicolas; Bao, Wen

2016-05-01

To enable the scramjet operate in a wider flight Mach number, a staged-combustor with dual-strut is introduced to hold more heat release at low flight Mach conditions. The behavior of mode transition was examined using a direct-connect model scramjet experiment along with pressure measurements. The typical operating modes of the staged-combustor are analyzed. Fuel injection scheme has a significant effect on the combustor operating modes, particularly for the supersonic combustion mode. Thrust performances of the combustor with different combustion modes and fuel distributions are reported in this paper. The first-staged strut injection has a better engine performance in the operation of subsonic combustion mode. On the contrast, the second-staged strut injection has a better engine performance in the operation of supersonic combustion mode.

Dual-wavelength passive and hybrid mode-locking of 3, 4.5 and 10 GHz InAs/InP(100) quantum dot lasers.

Science.gov (United States)

Tahvili, M S; Du, L; Heck, M J R; Nötzel, R; Smit, M K; Bente, E A J M

2012-03-26

We present an investigation of passive and hybrid mode-locking in Fabry-Pérot type two-section InAs/InP(100) quantum dot lasers that show dual wavelength operation. Over the whole current and voltage range for mode-locking of these lasers, the optical output spectra show two distinct lobes. The two lobes provide a coherent bandwidth and are verified to lead to two synchronized optical pulses. The generated optical pulses are elongated in time due to a chirp which shows opposite signs over the two spectral lobes. Self-induced mode-locking in the single-section laser shows that the dual-wavelength spectra correspond to emission from ground state. In the hybrid mode-locking regime, a map of locking range is presented by measuring the values of timing jitter for several values of power and frequency of the external electrical modulating signal. An overview of the systematic behavior of InAs/InP(100) quantum dot mode-locked lasers is presented as conclusion.

An in-situ infection detection sensor coating for urinary catheters.

Science.gov (United States)

Milo, Scarlet; Thet, Naing Tun; Liu, Dan; Nzakizwanayo, Jonathan; Jones, Brian V; Jenkins, A Toby A

2016-07-15

We describe a novel infection-responsive coating for urinary catheters that provides a clear visual early warning of Proteus mirabilis infection and subsequent blockage. The crystalline biofilms of P. mirabilis can cause serious complications for patients undergoing long-term bladder catheterisation. Healthy urine is around pH 6, bacterial urease increases urine pH leading to the precipitation of calcium and magnesium deposits from the urine, resulting in dense crystalline biofilms on the catheter surface that blocks urine flow. The coating is a dual layered system in which the lower poly(vinyl alcohol) layer contains the self-quenching dye carboxyfluorescein. This is capped by an upper layer of the pH responsive polymer poly(methyl methacrylate-co-methacrylic acid) (Eudragit S100®). Elevation of urinary pH (>pH 7) dissolves the Eudragit layer, releasing the dye to provide a clear visual warning of impending blockage. Evaluation of prototype coatings using a clinically relevant in vitro bladder model system demonstrated that coatings provide up to 12h advanced warning of blockage, and are stable both in the absence of infection, and in the presence of species that do not cause catheter blockage. At the present time, there are no effective methods to control these infections or provide warning of impending catheter blockage. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Micro generation of electricity with gasification gas in a engine generator in dual mode; Microgeracao de eletricidade com gas de gaseificacao num motor gerador dual

Energy Technology Data Exchange (ETDEWEB)

Silva, Marcelo Jose da; Souza, Samuel Nelson Melegari de; Souza, Abel Alves de; Ricieri, Reinaldo P. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PE (Brazil)], E-mail: marcelo_js07@hotmail.com

2010-07-01

Among the alternatives to the increase of world energy demand the use of biomass as energy source is one of the most promising as it contributes to reducing emissions of carbon dioxide in the atmosphere. Gasification is a process technology of biomass energy in a gaseous biofuel. The fuel gas got a low calorific value that can be used in diesel engine in dual mode for power generation in isolated communities. This study aimed to evaluate the reduction in the consumption of oil diesel an engine generator, using gas from gasification of wood. The engine generator brand used, it was a BRANCO, with direct injection power of 10 hp and mated to an electric generator 5,5 kW. The fuel gas was produced in a gasifier type co-current. The engine generator was put on load system from 0.5 kW to 3.5 kW through electric bank of heaters. For the oil diesel savings, the gas was injected mixed with intake air, as the oil diesel was normally injected by the injector of the engine (motor dual). The consumption od diesel was measured diesel by means of a precision scale. It was concluded that the engine converted to dual mode when using the gas for the gasification of wood showed a decrease in diesel consumption by up to 57%. (author)

Intracranial Pressure

DEFF Research Database (Denmark)

Hvedstrup, Jeppe; Radojicic, Aleksandra; Moudrous, Walid

2018-01-01

OBJECTIVE: To compare a new method of noninvasive intracranial pressure (nICP) measurement with conventional lumbar puncture (LP) opening pressure. METHODS: In a prospective multicenter study, patients undergoing LP for diagnostic purposes underwent intracranial pressure measurements with HeadSen...

Dual wavelength Mode-Locking of InAs/InP quantum dot laser diodes at 1.5µm

NARCIS (Netherlands)

Tahvili, M.S.; Heck, M.J.R.; Nötzel, R.; Smit, M.K.; Bente, E.A.J.M.

2011-01-01

We report on stable dual-wavelength mode-locking of 3.1GHz and 10GHz two-section InAs/InP(100) quantum dot laser diodes. Evaluation of relative time delay between different spectral components indicates opposite sign of chirp over the two spectral lobes

Colorimetric and Fluorescent Dual Mode Sensing of Alcoholic Strength in Spirit Samples with Stimuli-Responsive Infinite Coordination Polymers.

Science.gov (United States)

Deng, Jingjing; Ma, Wenjie; Yu, Ping; Mao, Lanqun

2015-07-07

This study demonstrates a new strategy for colorimetric and fluorescent dual mode sensing of alcoholic strength (AS) in spirit samples based on stimuli-responsive infinite coordination polymers (ICPs). The ICP supramolecular network is prepared with 1,4-bis(imidazol-1-ylmethyl)benzene (bix) as the ligand and Zn(2+) as the central metal ion in ethanol, in which rhodamine B (RhB) is encapsulated through self-adaptive chemistry. In pure ethanol solvent, the as-formed RhB/Zn(bix) is well dispersed and quite stable. However, the addition of water into the ethanol dispersion of RhB/Zn(bix) destroys Zn(bix) network structure, resulting in the release of RhB from ICP into the solvent. As a consequence, the solvent displays the color of released RhB and, at the meantime, turns on the fluorescence of RhB, which constitutes a new mechanism for colorimetric and fluorescent dual mode sensing of AS in commercial spirit samples. With the method developed here, we could distinguish the AS of different commercial spirit samples by the naked eye within a wide linear range from 20 to 100% vol and by monitoring the increase of fluorescent intensity of the released RhB. This study not only offers a new method for on-spot visible detection of AS in commercial spirit samples, but also provides a strategy for designing dual mode sensing mechanisms for different analytical purposes based on novel stimuli-responsive materials.

Analysis of Dual- and Full-Circular Polarimetric SAR Modes for Rice Phenology Monitoring: An Experimental Investigation through Ground-Based Measurements

Directory of Open Access Journals (Sweden)

Yuta Izumi

2017-04-01

Full Text Available Circularly polarized synthetic aperture radar (CP-SAR is known to be insensitive to polarization mismatch losses caused by the Faraday rotation effect and antenna misalignment. Additionally, the dual-circular polarimetric (DCP mode has proven to have more polarimetric information than that of the corresponding mode of linear polarization, i.e., the dual-linear polarimetric (DLP mode. Owing to these benefits, this paper investigates the feasibility of CP-SAR for rice monitoring. A ground-based CP-radar system was exploited, and C-band anechoic chamber data of a self-cultivated Japanese rice paddy were acquired from germination to ripening stages. Temporal variations of polarimetric observables derived from full-circular polarimetric (FCP and DCP as well as synthetically generated DLP data are analyzed and assessed with regard to their effectiveness in phenology retrieval. Among different observations, the H / α ¯ plane and triangle plots obtained by three scattering components (surface, double-bounce, and volume scattering for both the FCP and DCP modes are confirmed to have reasonable capability in discriminating the relevant intervals of rice growth.

Dual-mode optical fiber-based tweezers for robust trapping and manipulation of absorbing particles in air

Science.gov (United States)

Sil, Souvik; Kanti Saha, Tushar; Kumar, Avinash; Bera, Sudipta K.; Banerjee, Ayan

2017-12-01

We develop an optical tweezers system using a single dual-mode optical fiber where mesoscopic absorbing particles can be trapped in three dimensions and manipulated employing photophoretic forces. We generate a superposition of fundamental and first order Hermite-Gaussian beam modes by the simple innovation of coupling a laser into a commercial optical fiber designed to be single mode for a wavelength higher than that of the laser. We achieve robust trapping of the absorbing particles for hours using both the pure fundamental and superposition mode beams and attain large manipulation velocities of ˜5 mm s-1 in the axial direction and ˜0.75 mm s-1 in the radial direction. We then demonstrate that the superposition mode is more effective in trapping and manipulation compared to the fundamental mode by around 80%, which may be increased several times by the use of a pure first order Hermite-Gaussian mode. The work has promising implications for trapping and spectroscopy of aerosols in air using simple optical fiber-based traps.

Computed tomographic findings of traumatic intracranial lesions

International Nuclear Information System (INIS)

Jeong, Seong Wook; Kim, Il Young; Lee, Byung Ho; Kim, Ki Jeoung; Yoon, Il Gyu

1985-01-01

Traumatic intracranial lesion has been one of the most frequent and serious problem in neurosurgical pathology. Computed tomography made it possible to get prompt diagnosis and surgical intervention of intracranial lesions by its safety, fastness and accuracy. Computed tomographic scan was carried out on 1309 cases at Soonchunhyang Chunan Hospital for 15 months from October 1983 to December 1984. We have reviewed the computed tomographic scans of 264 patients which showed traumatic intracranial lesion. The result were as follows: 1. Head trauma was the most frequent diagnosed disease using computed tomographic scans (57.8%) and among 264 cases the most frequent mode of injury was traffic accident (73.9%). 2. Skull fracture was accompanied in frequency of 69.7% and it was detected in CT in 38.6%: depression fracture was more easily detected in 81%. 3. Conutercoup lesion (9.5%) was usually accompanied with temporal and occipital fracture, and it appeared in lower incidence among pediatric group. 4. Intracranial lesions of all 264 cases were generalized cerebral swelling (24.6%), subdural hematoma (22.3%), epidural hematoma (20.8%), intracerebral hematoma (6.1%), and subarachnoid hemorrhage (3.0%). 5. The shape of hematoma was usually biconvex (92.7%) in acute epidural hematoma and cresentic (100%) in acute subdural hematoma, but the most chronic the case became, they showed planoconvex and bicconvex shapes. 6. Extra-axial hematoma was getting decreased in density as time gone by. 7. Hematoma density was not in direct proportion to serum hemoglobin level as single factor

Computed tomographic findings of traumatic intracranial lesions

Energy Technology Data Exchange (ETDEWEB)

Jeong, Seong Wook; Kim, Il Young; Lee, Byung Ho; Kim, Ki Jeoung; Yoon, Il Gyu [Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

1985-10-15

Traumatic intracranial lesion has been one of the most frequent and serious problem in neurosurgical pathology. Computed tomography made it possible to get prompt diagnosis and surgical intervention of intracranial lesions by its safety, fastness and accuracy. Computed tomographic scan was carried out on 1309 cases at Soonchunhyang Chunan Hospital for 15 months from October 1983 to December 1984. We have reviewed the computed tomographic scans of 264 patients which showed traumatic intracranial lesion. The result were as follows: 1. Head trauma was the most frequent diagnosed disease using computed tomographic scans (57.8%) and among 264 cases the most frequent mode of injury was traffic accident (73.9%). 2. Skull fracture was accompanied in frequency of 69.7% and it was detected in CT in 38.6%: depression fracture was more easily detected in 81%. 3. Conutercoup lesion (9.5%) was usually accompanied with temporal and occipital fracture, and it appeared in lower incidence among pediatric group. 4. Intracranial lesions of all 264 cases were generalized cerebral swelling (24.6%), subdural hematoma (22.3%), epidural hematoma (20.8%), intracerebral hematoma (6.1%), and subarachnoid hemorrhage (3.0%). 5. The shape of hematoma was usually biconvex (92.7%) in acute epidural hematoma and cresentic (100%) in acute subdural hematoma, but the most chronic the case became, they showed planoconvex and bicconvex shapes. 6. Extra-axial hematoma was getting decreased in density as time gone by. 7. Hematoma density was not in direct proportion to serum hemoglobin level as single factor.

Intracranial Hypertension Research Foundation

Science.gov (United States)

... PARTNERSHIPS Meet our Fundraising Partners Tweet Welcome Intracranial hypertension (IH) is the general term for the neurological ... high. (Old names for IH include Benign Intracranial Hypertension and Pseudotumor Cerebri). The Intracranial Hypertension Research Foundation ...

Application of failure mode and effect analysis in managing catheter-related blood stream infection in intensive care unit.

Science.gov (United States)

Li, Xixi; He, Mei; Wang, Haiyan

2017-12-01

In this study, failure mode and effect analysis (FMEA), a proactive tool, was applied to reduce errors associated with the process which begins with assessment of patient and ends with treatment of complications. The aim of this study is to assess whether FMEA implementation will significantly reduce the incidence of catheter-related bloodstream infections (CRBSIs) in intensive care unit.The FMEA team was constructed. A team of 15 medical staff from different departments were recruited and trained. Their main responsibility was to analyze and score all possible processes of central venous catheterization failures. Failure modes with risk priority number (RPN) ≥100 (top 10 RPN scores) were deemed as high-priority-risks, meaning that they needed immediate corrective action. After modifications were put, the resulting RPN was compared with the previous one. A centralized nursing care system was designed.A total of 25 failure modes were identified. High-priority risks were "Unqualified medical device sterilization" (RPN, 337), "leukopenia, very low immunity" (RPN, 222), and "Poor hand hygiene Basic diseases" (RPN, 160). The corrective measures that we took allowed a decrease in the RPNs, especially for the high-priority risks. The maximum reduction was approximately 80%, as observed for the failure mode "Not creating the maximal barrier for patient." The averaged incidence of CRBSIs was reduced from 5.19% to 1.45%, with 3 months of 0 infection rate.The FMEA can effectively reduce incidence of CRBSIs, improve the security of central venous catheterization technology, decrease overall medical expenses, and improve nursing quality. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

A Multifunctional Isolated and Non-Isolated Dual Mode Converter for Renewable Energy Conversion Applications

Directory of Open Access Journals (Sweden)

Yiwang Wang

2017-11-01

Full Text Available In this paper, a multifunctional isolated and non-isolated dual-mode low-power converter was designed for renewable energy conversion applications such as photovoltaic power generation to achieve different operating modes under bi-directional electrical conversion. The proposed topology consists of a bidirectional non-isolated DC/DC circuit and an isolated converter with a high-frequency transformer, which merge the advantages of both the conventional isolated converter and non-isolated converter with the combination of the two converter technologies. Compared with traditional converters, the multifunctional converter can not only realize conventional bi-directional functions, but can also be applied for many different operation modes and meet the high output/input ratio demands with the two converter circuits operating together. A novel control algorithm was proposed to achieve the various functions of the proposed converter. An experimental platform based on the proposed circuit was established. Both the simulation and experimental results indicated that the proposed converter could provide isolated and non-isolated modes in different applications, which could meet different practical engineering requirements.

The exercise and affect relationship: evidence for the dual-mode model and a modified opponent process theory.

Science.gov (United States)

Markowitz, Sarah M; Arent, Shawn M

2010-10-01

This study examined the relationship between exertion level and affect using the framework of opponent-process theory and the dual-mode model, with the Activation-Deactivation Adjective Checklist and the State Anxiety Inventory among 14 active and 14 sedentary participants doing 20 min of treadmill exercise at speeds of 5% below, 5% above, and at lactate threshold (LT). We found a significant effect of time, condition, Time × Condition, and Time × Group, but no group, Group × Condition, or Time × Group × Condition effects, such that the 5% above LT condition produced a worsening of affect in-task compared with all other conditions whereas, across conditions, participants experienced in-task increases in energy and tension, and in-task decreases in tiredness and calmness relative to baseline. Posttask, participants experienced mood improvement (decreased tension, anxiety, and increased calmness) across conditions, with a 30-min delay in the above LT condition. These results partially support the dual-mode model and a modified opponent-process theory.

Central venous cannulation: are routine chest radiographs necessary after B-mode and colour Doppler sonography check?

International Nuclear Information System (INIS)

Lanza, Cecilia; Fabrizzi, Giancarlo; Russo, Marco

2006-01-01

After the insertion of a central venous catheter, a chest radiograph is usually obtained to ensure correct positioning of the catheter tip. To determine in a paediatric population whether B-mode and colour Doppler sonography after central venous access is useful to evaluate catheter position, thus obviating the need for a postprocedural radiograph. A prospective study of 107 consecutive central venous access procedures placed in a paediatric intensive care unit was performed. At the end of the procedure, B-mode and colour Doppler sonography were used to assess catheter position and check for complications. A postprocedural chest radiograph was obtained in all patients. In 96 patients postprocedural B-mode and colour Doppler sonography showed colour Doppler signals within the vena cava. Among the 11 patients predicted to have a potential complication, there was one pneumothorax and ten malpositions. Chest radiography showed a total of 13 complications - 1 pneumothorax and 12 malpositions. The concordance between colour Doppler sonography and chest radiography was 98.1% in the detection of catheter position; sonography had a sensitivity of 84.6% and a specificity of 100%. The close concordance between B-mode and colour Doppler sonography and chest radiography justifies the more frequent use of sonography to evaluate catheter position because ionizing radiation is eliminated. Chest radiography may then be performed only when there is suspected inappropriate catheter tip position after sonography. (orig.)

Indwelling catheter care

Science.gov (United States)

Foley catheter ... You will need to make sure your indwelling catheter is working properly. You will also need to ... not get an infection or skin irritation. Make catheter and skin care part of your daily routine. ...

Multi-mode vibration control of piping system

International Nuclear Information System (INIS)

Minowa, Takeshi; Seto, Kazuto; Iiyama, Fumiya; Sodeyama, Hiroshi

1999-01-01

In this paper, dual dynamic absorbers are applied to the piping system in order to control the multiple vibration modes. ANSYS, which is one of the software based on FEM(finite element method), is used for the design of dual dynamic absorbers as well as for the determination of their optimum installing positions. The dual dynamic absorbers designed optimally for controlling the first three vibration modes perform just like a houde damper in higher frequency and have an effect on controlling higher modes. To use this advantage, three dual dynamic absorbers are installed in positions where they influence higher modes, and not only the first three modes of the piping system but also the extensive modes are controlled. Practical experimental study has also been carried out and it is shown that a dual dynamic absorber is suitable for controlling the vibration of the piping system. (author)

Dual-mode switching of a liquid crystal panel for viewing angle control

Science.gov (United States)

Baek, Jong-In; Kwon, Yong-Hoan; Kim, Jae Chang; Yoon, Tae-Hoon

2007-03-01

The authors propose a method to control the viewing angle of a liquid crystal (LC) panel using dual-mode switching. To realize both wide viewing angle (WVA) characteristics and narrow viewing angle (NVA) characteristics with a single LC panel, the authors use two different dark states. The LC layer can be aligned homogeneously parallel to the transmission axis of the bottom polarizer for WVA dark state operation, while it can be aligned vertically for NVA dark state operation. The authors demonstrated that viewing angle control can be achieved with a single panel without any loss of contrast at the front.

Cardiac pacemaker dysfunction in children after thoracic drainage catheter manipulation.

Science.gov (United States)

Lobdell, K W; Walters, H L; Hudson, C; Hakimi, M

1997-05-01

Two children underwent placement of permanent, epicardial-lead, dual-chamber, unipolar pacemaker systems for complete heart block. Postoperatively, both patients demonstrated subcutaneous emphysema-in the area of their pulse generators-temporally related to thoracic catheter manipulation. Acutely, each situation was managed with manual compression of the pulse generator, ascertaining appropriate pacemaker sensing and pacing. Maintenance of compression with pressure dressings, vigilant observation/monitoring, and education of the care givers resulted in satisfactory pacemaker function without invasive intervention.

Thrombectomy approach using pediatric Foley catheter in lateral sinus thrombosis developed as a complication of chronic otitis media in a patient with sickle cell anemia

Directory of Open Access Journals (Sweden)

Ercan Akbay

2014-04-01

Full Text Available Lateral sinus thrombophlebitis (LST is a rarely seen intracranial complication of chronic otitis media. Even single case report may guide in this entity given the lack of larger series. In the present manuscript, we will discuss removal of infected thrombus localized in transverse sinus via Foley catheter in a 46-years old man with sickle cell anemia underwent surgery due to LST.

Probing the fundamental limit of niobium in high radiofrequency fields by dual mode excitation in superconducting radiofrequency cavities

International Nuclear Information System (INIS)

Eremeev, Grigory; Geng, Rongli; Palczewski, Ari

2011-01-01

We have studied thermal breakdown in several multicell superconducting radiofrequency cavity by simultaneous excitation of two TM 010 passband modes. Unlike measurements done in the past, which indicated a clear thermal nature of the breakdown, our measurements present a more complex picture with interplay of both thermal and magnetic effects. JLab LG-1 that we studied was limited at 40.5 MV/m, corresponding to B peak = 173 mT, in 89 mode. Dual mode measurements on this quench indicate that this quench is not purely magnetic, and so we conclude that this field is not the fundamental limit in SRF cavities

High-power terahertz optical pulse generation with a dual-wavelength harmonically mode-locked Yb:YAG laser

International Nuclear Information System (INIS)

Zhuang, W Z; Chang, M T; Su, K W; Huang, K F; Chen, Y F

2013-01-01

We report on high-power terahertz optical pulse generation with a dual-wavelength harmonically mode-locked Yb:YAG laser. A semiconductor saturable absorber mirror is developed to achieve synchronously mode-locked operation at two spectral bands centered at 1031.67 and 1049.42 nm with a pulse duration of 1.54 ps and a pulse repetition rate of 80.3 GHz. With a diamond heat spreader to improve the heat removal efficiency, the average output power can be up to 1.1 W at an absorbed pump power of 5.18 W. The autocorrelation traces reveal that the mode-locked pulse is modulated with a beat frequency of 4.92 THz and displays a modulation depth to be greater than 80%. (paper)

A Comparative Study of Voltage, Peak Current and Dual Current Mode Control Methods for Noninverting Buck-Boost Converter

Directory of Open Access Journals (Sweden)

M. Č. Bošković

2016-06-01

Full Text Available This paper presents a comparison of voltage mode control (VMC and two current mode control (CMC methods of noninverting buck-boost converter. The converter control-to-output transfer function, line-to-output transfer function and the output impedance are obtained for all methods by averaging converter equations over one switching period and applying small-signal linearization. The obtained results are required for the design procedure of feedback compensator to keep a system stable and robust. A comparative study of VMC, peak current mode control (PCMC and dual-current mode control (DCMC is performed. Performance evaluation of the closed-loop system with obtained compensator between these methods is performed via numerical simulations.

Dual-mode, high energy utilization system concept for mars missions

International Nuclear Information System (INIS)

El-Genk, Mohamed S.

2000-01-01

This paper describes a dual-mode, high energy utilization system concept based on the Pellet Bed Reactor (PeBR) to support future manned missions to Mars. The system uses proven Closed Brayton Cycle (CBC) engines to partially convert the reactor thermal power to electricity. The electric power generated is kept the same during the propulsion and the power modes, but the reactor thermal power in the former could be several times higher, while maintaining the reactor temperatures almost constant. During the propulsion mode, the electric power of the system, minus ∼1-5 kW e for house keeping, is used to operate a Variable Specific Impulse Magnetoplasma Rocket (VASIMR). In addition, the reactor thermal power, plus more than 85% of the head load of the CBC engine radiators, are used to heat hydrogen. The hot hydrogen is mixed with the high temperature plasma in a VASIMR to provide both high thrust and I sp >35,000 N.s/kg, reducing the travel time to Mars to about 3 months. The electric power also supports surface exploration of Mars. The fuel temperature and the inlet temperatures of the He-Xe working fluid to the nuclear reactor core and the CBC turbine are maintained almost constant during both the propulsion and power modes to minimize thermal stresses. Also, the exit temperature of the He-Xe from the reactor core is kept at least 200 K below the maximum fuel design temperature. The present system has no single point failure and could be tested fully assembled in a ground facility using electric heaters in place of the nuclear reactor. Operation and design parameters of a 40-kW e prototype are presented and discussed to illustrate the operation and design principles of the proposed system

Research on Adaptive Dual-Mode Switch Control Strategy for Vehicle Maglev Flywheel Battery

Directory of Open Access Journals (Sweden)

Hui Gao

2015-01-01

Full Text Available Because of the jamming signal is real-time changeable and control algorithm cannot timely tracking control flywheel rotor, this paper takes vehicle maglev flywheel battery as the research object. One kind of dual-model control strategy is developed based on the analysis of the vibration response impact of the flywheel battery control system. In view of the complex foundation vibration problems of electric vehicles, the nonlinear dynamic simulation model of vehicle maglev flywheel battery is solved. Through analyzing the nonlinear vibration response characteristics, one kind of dual-mode adaptive hybrid control strategy based on H∞ control and unbalance displacement feed-forward compensation control is presented and a real-time switch controller is designed. The reliable hybrid control is implemented, and the stability in the process of real-time switch is solved. The results of this project can provide important basic theory support for the research of vehicle maglev flywheel battery control system.

A dose-per-pulse monitor for a dual-mode medical accelerator

International Nuclear Information System (INIS)

Galbraith, D.M.; Martell, E.S.; Fueurstake, T.; Norrlinger, B.; Schwendener, H.; Rawlinson, J.A.

1990-01-01

On a radiotherapy accelerator, the dose monitoring system is the last level of protection between the patient and the extremely high dose rate which all accelerators are capable of producing. The risk of losing this level of protection is substantially reduced if two or more dose monitoring systems are used which are mechanically and electrically independent in design. This paper describes the installation of an independent radiation monitor in a dual-mode, computer-controlled accelerator with a moveable monitor chamber. The added device is fixed in the beam path, is capable of monitoring each beam pulse, and is capable of terminating irradiation within the pulse repetition period if any measured pulse is unacceptably high

Compact 84 GHz passive mode-locked fiber laser using dual-fiber coupled fused-quartz microresonator

Science.gov (United States)

Liu, Tze-An; Hsu, Yung; Chow, Chi-Wai; Chuang, Yi-Chen; Ting, Wei-Jo; Wang, Bo-Chun; Peng, Jin-Long; Chen, Guan-Hong; Chang, Yuan-Chia

2017-10-01

We propose and demonstrate a compact and portable-size 84-GHz passive mode-locked fiber laser, in which a dual-fiber coupled fused-quartz microresonator is employed as the intracavity optical comb filter as well as the optical nonlinear material for optical frequency comb generation. About eight coherent optical tones can be generated in the proposed fiber laser. The 20-dB bandwidth is larger than 588 GHz. The full-width half-maximum pulse-width of the proposed laser is 2.5 ps. We also demonstrate the feasibility of using the proposed passive mode-locked fiber laser to carry a 5-Gbit/s on-off-keying signal and transmit over 20-km standard single mode fiber. A 7% forward error correction requirement can be achieved, showing the proposed fiber laser can be a potential candidate for fiber-wireless applications.

A novel detector based on dual-mode fiber polished half block's characteristics for sensitive monitorings of radiation and materials

International Nuclear Information System (INIS)

Saeed, Ghadirli

2005-01-01

Full text : The overlay index dependence characteristics of the power distribution between two modes of dual-mode fiber polished half blocks is studied. The heat dependence characteristics of a certain overlay index affects the modal power distributions at the input of interferometer sensors used for monitoring the sensitive heat radiation changes. The other fundamental applications such as material recognitions through the index dependence characteristics in the closed chambers is also suggested

Pressure-controlled drainage of cerebrospinal fluid: clinical experience with a new type of ventricular catheter (Ventcontrol MTC)and an integrated Piezo-resistive sensor at its tip: technical note.

Science.gov (United States)

Piek, J; Raes, P

1996-01-01

We described a new ventricular catheter that is the combination of a "classic" ventricular catheter with a piezo-resistive transducer at its tip. The device allows parallel recordings of intraventricular fluid pressure via a chip and a fluid-filled external transducer, drainage of cerebrospinal fluid from the ventricle or injection of fluid into the ventricle with simultaneous monitoring of intracranial pressure, and recording of brain tissue pressure in cases of misplacement or dislocation of the ventricular catheter or in cases of progressively narrowing ventricles caused by brain edema. Clinical tests in various situations at different pressure ranges (total recording time, 1356 h in 13 patients) gave excellent correlations of both pressures. Application of the device is especially indicated in clinical situations in which pressure-controlled drainage is desirable, occlusion of ventricular bolts is likely, or pressure-volume tests are needed.

Designing a dual-mode broadband solar spectral converter: The example of Bi{sup 3+}, Cr{sup 3+}, Yb{sup 3+}-tridoped perovskite

Energy Technology Data Exchange (ETDEWEB)

Lin, Li-Tian; Wu, Xuan-Ming; Wang, Ting; Chen, Dong-Ju; Deng, Chao; Meng, Jian-Xin, E-mail: tmjx@jnu.edu.cn; Cao, Li-Wei

2016-07-15

A promising dual-mode broadband solar spectral converter CaTiO{sub 3}: Bi{sup 3+}, Cr{sup 3+}, Yb{sup 3+} was successfully developed by solid-stated reaction. The structure, photoluminescence (PL), photoluminescence excitation (PLE) and diffuse reflectance (DR) spectra in the UV–vis–NIR region have been systematically investigated. The results show that the as-prepared samples simultaneously exhibit two distinct spectral converting patterns, nonlinear quantum-cutting (QC) involving Bi{sup 3+}–Ti{sup 4+} metal-to-metal charge transfer state (BT-MMCTs) → Yb{sup 3+}: {sup 2}F{sub 5/2} + Yb{sup 3+}: {sup 2}F{sub 5/2} and linear downshift (DS) involving Cr{sup 3+}: {sup 4}T{sub 2} → Yb{sup 3+}: {sup 2}F{sub 5/2}. It deduces that the nonlinear QC is based on a cooperative energy transfer (CET) process while the linear DS belongs to a dipole–dipole mechanism. With the present converter, broadband UV–vis (300–700 nm) photons, which are not fully utilized by the existing c-Si solar cells, can be efficiently harvested and converted into ∼1000 nm NIR photons via the dual-mode mechanism. Moreover, not only the PLE spectrum of CaTiO{sub 3}: Bi{sup 3+}, Cr{sup 3+}, Yb{sup 3+} matched well with that of the solar radiation, but also its NIR emission peak position fell well over the spectral response of the commercial crystalline Si (c-Si) solar cells. This as-prepared dual-mode solar spectral converter with multiple advantages can simultaneously realize high quantum yield and broadband conversion, which offers a new and effective way to boost the conversion efficiency of c-Si solar cells. We believe this novel design of dual-mode solar spectral converters can inspire a direction for the synthesis of more advanced UV–vis–NIR phosphors that can be used in Si solar cells. - Highlights: • A dual-mode broadband solar spectral converter is designed and developed. • The energy transfer mechanism relies on quantum-cutting as well as downshift. • The PLE

Research on a six-phase permanent magnet synchronous motor system at dual-redundant and fault tolerant modes in aviation application

Directory of Open Access Journals (Sweden)

Xiaolin KUANG

2017-08-01

Full Text Available With the development of more/all electrical aircraft technology, an electro-mechanical actuator (EMA is more and more used in an aircraft actuation system. The motor system, as the crucial part of an EMA, usually adopts the redundancy technology or fault tolerance technology to improve the reliability. To compare the performances of these two motor systems, a 10-pole/12-slot six-phase permanent magnet synchronous motor (PMSM is designed with the concentrated single-layer winding, which is able to operate at dual-redundant and fault tolerant modes. Furthermore, the position servo performances of the six-phase PMSM at dual-redundant and fault tolerant modes are analyzed, including the normal and fault conditions. In addition, a variable structure proportional-integral-derivative (PID control strategy is proposed to solve the performance degradation problem caused by phase current saturation. Simulation and experimental results show that the fault tolerant PMSM has a better position servo performance than the dual-redundant PMSM, and the variable structure PID control strategy is able to improve the performance due to phase current saturation.

Design and multifidelity analysis of dual mode scramjet compression system using coupled NPSS and fluent simulation

Science.gov (United States)

Vijayakumar, Nandakumar

Hypersonic airbreathing engines mark a potential future development of the aerospace industry and immense efforts have been taken in gaining knowledge in them for the past decades. The physical phenomenon occurring at the hypersonic flow regime makes the design and performance prediction of a scramjet engine hard. Though cutting-edge simulation tools fight their way toward accurate prediction of the environment, the time consumed by the entire process in designing and analyzing a scramjet engine and its component may be exorbitant. A multi-fidelity approach for designing a scramjet with a cruising Mach number of 6 is detailed in this research where high-order simulations are applied according to the physics involved in the component. Two state-of-the-art simulation tools were used to take the aerodynamic and propulsion disciplines into account for realistic prediction of the individual components as well as the entire scramjet. The specific goal of this research is to create a virtual environment to design and analyze a hypersonic, two-dimensional, planar inlet and isolator to check its operability for a dual-mode scramjet engine. The dual mode scramjet engine starts at a Mach number of 3.5 where it operates as a ramjet and accelerates to Mach 6 to be operated as a scramjet engine. The intercomponent interaction between the compression components with the rest of the engine is studied by varying the fidelity of the numerical simulation according to the complexity of the situation. Efforts have been taken to track the transition Mach number as it switches from ramjet to scramjet. A complete scramjet assembly was built using the Numerical Propulsion Simulation System (NPSS) and the performance of the engine was evaluated for various scenarios. Different numerical techniques were opted for varying the fidelity of the analysis with the highest fidelity consisting of 2D RANS CFD simulation. The interaction between the NPSS elements with the CFD solver is governed by the

Percutenous Catheter Ablation of the Accessory Pathway in a Patient with Wolff-Parkinson-White Syndrome Associated with Familial Atrial Fibrillation

Science.gov (United States)

Cay, Serkan; Topaloglu, Serkan; Aras, Dursun

2008-01-01

Percutenous catheter ablation of the accessory pathway in Wolff-Parkinson-White syndrome is a highly successful mode of therapy. Sudden cardiac arrest survivors associated with WPW syndrome should undergo radiofrequency catheter ablation. WPW syndrome associated with familial atrial fibrillation is a very rare condition. Herein, we describe a case who presented with sudden cardiac arrest secondary to WPW syndrome and familial atrial fibrillation and treated via radiofrequency catheter ablation. PMID:18379660

Sistim Tampilan Jadwal Pesawat Udara Dengan Mode Dual Display Di Bandara Ahmad Yani Semarang

Directory of Open Access Journals (Sweden)

Hari Suseno

2014-02-01

Full Text Available Schedule for airline passengers is important information that is provided by the airport manager. Airport flight information on the display screen using a media schedule called flight information display system (FIDS. FIDS system comes from two processes that display arrival and departure information. The device comes from the appearance of two separate computer with information for each. The use of two computers that are used to the old system at the airport FIDS devices. This research aims to create an integrated FIDS system device to combine the information into one unified display in dual display mode pattern display (dual view. Design systems using software programming VB6 and hardware modifications applied to design a system FIDS new on view flight schedules. With a centralized system obtained an interactive display schedules for flight schedule. Keywords : FIDS system; Flight schedule; Display  information

Dual origin of the left vertebral artery: extracranial MRA and CTA findings.

LENUS (Irish Health Repository)

Tobin, W Oliver

2012-02-01

A 48-year-old man presented with a posterior circulation stroke secondary to left lateral medullary infarction. Contrast-enhanced magnetic resonance angiography (CEMRA) revealed 40-45% intracranial left vertebral artery stenosis, likely atherosclerotic in nature. CEMRA and subsequent computed tomography angiography also identified a duplicate origin of the left vertebral artery. The importance of recognition of this rare anatomical variant, its potential contribution to stroke aetiology, and the advantage of non-invasive vascular imaging prior to catheter angiography is emphasised.

Catheter visualisation in MR tomography: first animal experimental experiences with field inhomogeneity catheters

International Nuclear Information System (INIS)

Adam, G.; Glowinski, A.; Neuerburg, J.; Buecker, A.; Vaals, J.J. van; Hurtak, W.; Guenther, R.W.

1997-01-01

Purpose: To assess the feasibility of a new developed field inhomogeneity catheter for interventional MR imaging in vivo. Materials and methods: Three different prototypes of a field inhomogeneity catheter were investigated in 6 pigs. The catheters were introduced in Seldinger technique via the femoral vessels over a guide wire on an interventional MR system (Philips Gyroscan NT combined with a C-arm fluoroscopy unit [Philips BV 212[). Catheters were placed in veins and arteries. The catheter position was controlled by a fast gradient echo sequence (Turbo Field Echo [TEF[). Results: Catheters were introduced over a guide wire without complications in all cases. Using the field inhomogeneity concept, catheters were easily visualised in the inferior vena cava and the aorta by the fast gradient echo technique on MR in all cases. Although aortic branches were successfully cannulated, the catheters were not displayed by the TFE technique due to the complex and tortuous anatomy. All animals survived the experiments without complications. Conclusion: MR guided visualisation of a field inhomogeneity catheter is a simple concept which can be realised on each MR scanner and may allow intravascular MR guided interventions in future. (orig.) [de

Giant Gold Nanowire Vesicle-Based Colorimetric and SERS Dual-Mode Immunosensor for Ultrasensitive Detection of Vibrio parahemolyticus.

Science.gov (United States)

Guo, Zhiyong; Jia, Yaru; Song, Xinxin; Lu, Jing; Lu, Xuefei; Liu, Baoqing; Han, Jiaojiao; Huang, Youju; Zhang, Jiawei; Chen, Tao

2018-05-15

Conventional methods for the detection of Vibrio parahemolyticus (VP) usually need tedious, labor-intensive processes, and have low sensitivity, which further limits their practical applications. Herein, we developed a simple and efficient colorimetry and surface-enhanced Raman scattering (SERS) dual-mode immunosensor for sensitive detection of VP, by employing giant Au vesicles with anchored tiny gold nanowires (AuNW) as a smart probe. Due to the larger specific surface and special hollow structure of giant Au vesicles, silver staining would easily lead to vivid color change for colorimetric analysis and further amplify SERS signals. The t-test was further used to determine if two sets of data from colorimetry and SERS were significantly different from each other. The result shows that there was no significant difference between data from the two methods. Two sets of data can mutually validate each other and avoid false positive and negative detection. The designed colorimetry-SERS dual-mode sensor would be very promising in various applications such as food safety inspection, personal healthcare, and on-site environmental monitoring.

Catheter Angiography

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography ...

Dual-wavelength passive and hybrid mode-locking of 3, 4.5 and 10 GHz InAs/InP(100) quantum dot lasers

NARCIS (Netherlands)

Tahvili, M.S.; Du, L.; Heck, M.J.R.; Nötzel, R.; Smit, M.K.; Bente, E.A.J.M.

2012-01-01

We present an investigation of passive and hybrid mode-locking in Fabry-Pérot type two-section InAs/InP(100) quantum dot lasers that show dual wavelength operation. Over the whole current and voltage range for mode-locking of these lasers, the optical output spectra show two distinct lobes. The two

Catheter Angiography

Medline Plus

Full Text Available ... imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an artery ... examined, a contrast material is injected through the tube and images are captured using a small dose ...

Catheter Angiography

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Full Text Available ... incision in the skin. Once the catheter is guided to the area being examined, a contrast material ... inserted into an artery. The catheter is then guided through the arteries to the area to be ...

Catheter Angiography

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Full Text Available ... catheter , is inserted into an artery through a small incision in the skin. Once the catheter is ... the tube and images are captured using a small dose of ionizing radiation ( x-rays ). top of ...

Catheter Angiography

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Full Text Available ... it will make the rest of the procedure pain-free. You will not feel the catheter in ... nurse if you notice any bleeding, swelling or pain at the site where the catheter entered the ...

Catheter Angiography

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Full Text Available ... should inform the nurse if you notice any bleeding, swelling or pain at the site where the ... Rarely, the catheter punctures the artery, causing internal bleeding. It also is possible that the catheter tip ...

Catheter Angiography

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Full Text Available ... an artery through a small incision in the skin. Once the catheter is guided to the area ... small incision (usually a few millimeters) in the skin where the catheter can be inserted into an ...

Catheter Angiography

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Full Text Available ... or other procedures such as chemoembolization or selective internal radiation therapy. identify dissection or splitting in the ... days. Rarely, the catheter punctures the artery, causing internal bleeding. It also is possible that the catheter ...

Catheter Angiography

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Full Text Available ... is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, ... tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of ...

Catheter Angiography

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Full Text Available ... Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material to examine ... removable dental appliances, eye glasses and any metal objects or clothing that might interfere with the x- ...

Catheter Angiography

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Full Text Available ... most cases, the kidneys will regain their normal function within five to seven days. Rarely, the catheter ... limitations of Catheter Angiography? Patients with impaired kidney function, especially those who also have diabetes, are not ...

Bacillus Cereus catheter related bloodstream infection in a patient in a patient with acute lymphblastic leukemia

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Lütfiye Öksüz

2012-01-01

Full Text Available Bacillus cereus infection is rarely associated with actual infection and for this reason single positive blood culture is usually regarded as contamination . However it may cause a number of infections, such catheter-related blood stream infections. Significant catheter-related bloodstream infections (CRBSI caused by Bacillus spp. are mainly due to B.cereus and have been predominantly reported in immunocompromised hosts1 . Catheter removal is generally advised for management of infection. In this report, catheter-related bacteremia caused by B.cereus in a patient with acute lymphoblastıc leukemia (ALL in Istanbul Medical Faculty was presented.A 44-year old man presented with fatigue, weight loss, epistaxis and high fever. A double-lumen Hickman–catheter (Bard 12.0 Fr, Round Dual Lumen was inserted by surgical cut-down to access the right subclavian vein which would be necessary for allogeneic stem cell transplantation. Three weeks later the patient presented with high fever and headache. Bacillus spp. was isolated from the cathether while blood culture obtained from the peripheral vein remained negative. The bacterial identification was confirmed as B.cereus using VITEK identification system It has been reported Bacillus cereus septicemia may be fatal in immunocompromised hosts despite broad-spectrum appropriate treatment10. Catheter removal is essential for prevention of recurrent bacteremia. Long-term cathater salvage should be reserved for appropriate patient group.

Catheter-related bloodstream infection.

Science.gov (United States)

Goede, Matthew R; Coopersmith, Craig M

2009-04-01

Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed.

Catheter Angiography

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Full Text Available ... lies. The catheter used in angiography is a long plastic tube about as thick as a strand of spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ...

Percutenous Catheter Ablation of the Accessory Pathway in a Patient with Wolff-Parkinson-White Syndrome Associated with Familial Atrial Fibrillation

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Serkan Cay

2008-04-01

Full Text Available Percutenous catheter ablation of the accessory pathway in Wolff-Parkinson-White syndrome is a highly successful mode of therapy. Sudden cardiac arrest survivors associated with WPW syndrome should undergo radiofrequency catheter ablation. WPW syndrome associated with familial atrial fibrillation is a very rare condition. Herein, we describe a case who presented with sudden cardiac arrest secondary to WPW syndrome and familial atrial fibrillation and treated via radiofrequency catheter ablation.

Catheter Angiography

Medline Plus

Full Text Available ... is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a ... tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a ...

A central venous catheter coated with benzalkonium chloride for the prevention of catheter-related microbial colonization.

Science.gov (United States)

Moss, H A; Tebbs, S E; Faroqui, M H; Herbst, T; Isaac, J L; Brown, J; Elliott, T S

2000-11-01

In an attempt to overcome infections associated with central venous catheters, a new antiseptic central venous catheter coated with benzalkonium chloride on the internal and external surfaces has been developed and evaluated in a clinical trial. Patients (235) randomly received either a triple-lumen central venous catheter coated with benzalkonium chloride (117) or a polyurethane non-antiseptic catheter (118). The incidence of microbial colonization of both catheters and retained antiseptic activity of the benzalkonium chloride device following removal were determined. The benzalkonium chloride resulted in a significant reduction of the incidence of microbial colonization on both the internal and external catheter surfaces. The reduction in colonization was detected at both the intradermal (21 benzalkonium chloride catheters vs. 38 controls, P = 0.0016) and distal segments of the antiseptic-coated catheters. Following catheter removal retained activity was demonstrated in benzalkonium chloride catheters which had been in place for up to 12 days. No patients developed adverse reactions to the benzalkonium chloride catheters. The findings demonstrate that the benzalkonium chloride catheter significantly reduced the incidence of catheter-associated colonization.

High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

Science.gov (United States)

Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

2015-01-01

Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s−1 with high accuracy (p-value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em < 10, E/A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation. PMID:25505135

Hemodialysis catheter insertion: is increased PO2 a sign of arterial cannulation? A case report.

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Chirinos, Julio C; Neyra, Javier A; Patel, Jiten; Rodan, Aylin R

2014-07-29

Ultrasound-guided Central Venous Catheterization (CVC) for temporary vascular access, preferably using the right internal jugular vein, is widely accepted by nephrologists. However CVC is associated with numerous potential complications, including death. We describe the finding of a rare left-sided partial anomalous pulmonary vein connection during central venous catheterization for continuous renal replacement therapy (CRRT). Ultrasound-guided cannulation of a large bore temporary dual-lumen Quinton-Mahurkar catheter into the left internal jugular vein was performed for CRRT initiation in a 66 year old African-American with sepsis-related oliguric acute kidney injury. The post-procedure chest X-ray suggested inadvertent left carotid artery cannulation. Blood gases obtained from the catheter showed high partial pressure of oxygen (PO2) of 140 mmHg and low partial pressure of carbon dioxide (PCO2) of 22 mmHg, suggestive of arterial cannulation. However, the pressure-transduced wave forms appeared venous and Computed Tomography Angiography located the catheter in the left internal jugular vein, but demonstrated that the tip of the catheter was lying over a left pulmonary vein which was abnormally draining into the left brachiocephalic (innominate) vein rather than into the left atrium. Although several mechanical complications of dialysis catheters have been described, ours is one of the few cases of malposition into an anomalous pulmonary vein, and highlights a sequential approach to properly identify the catheter location in this uncommon clinical scenario.

Use of thromboelastography to tailor dual-antiplatelet therapy in patients undergoing treatment of intracranial aneurysms with the Pipeline embolization device.

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McTaggart, Ryan A; Choudhri, Omar A; Marcellus, Mary L; Brennan, Tom; Steinberg, Gary K; Dodd, Robert L; Do, Huy M; Marks, Michael P

2015-06-01

Platelet function testing is controversial and not well studied in patients with neurovascular disease. To evaluate the performance of thromboelastography (TEG) as a platelet function test in neurovascular patients treated with the Pipeline embolization device (PED). A prospective protocol was instituted for platelet function testing in patients undergoing repair of intracranial aneurysms with the PED. All patients received dual antiplatelet therapy (DAT) and their response to both P2Y12 inhibitors and aspirin was quantified with TEG. Each patient's DAT induction strategy was tailored based on the percentage ADP-induced and percentage arachidonic acid-induced platelet inhibition reported by TEG. Data collected included clinical presentation, aneurysm characteristics, treatment details, and periprocedural events. Patients were followed up clinically and/or angiographically at 30 days, 6 months, and 1 year. Thirty-four PED procedures were performed on 31 patients. TEG results altered the DAT strategy in 35% of patients. Technical success with the Pipeline placement was 100%. Two patients had minor strokes and five had transient ischemic attacks (TIAs). There have been no hemorrhagic complications. No patient had permanent neurologic deficits. Six of eight (75%) of patients with thromboembolic/TIA events were ADP-induced hyporesponders by TEG. Our 6- and 12-month angiographic occlusion rates were 78.9% and 89.5%, respectively. The 19 major branches covered by the PED that were assessed by follow-up imaging have all remained patent. Platelet function testing with TEG altered our DAT induction strategy in a significant number of cases. No hemorrhagic or disabling thromboembolic complications were seen in this series. Future studies should compare methods of platelet function testing and, possibly, no platelet function testing in neurovascular patients undergoing flow diversion and/or stent-assisted treatment of intracranial aneurysms. Published by the BMJ

Dual mode antibacterial activity of ion substituted calcium phosphate nanocarriers for bone infections

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Sampath Kumar eT.S.

2015-05-01

Full Text Available Nanotechnology has tremendous potential for the management of infectious diseases caused by multi-drug resistant (MDR bacteria, through the development of newer antibacterial materials and efficient modes of antibiotic delivery. Calcium phosphate (CaP bioceramics are commonly used as bone substitutes due to their similarity to bone mineral and are widely researched upon for the treatment of bone infections associated with bone loss. CaPs can be used as local antibiotic delivery agents for bone infections and can be substituted with antibacterial ions in their crystal structure to have a wide spectrum, sustained antibacterial activity even against drug resistant bacteria. In the present work, a dual mode antibiotic delivery system with antibacterial ion substituted calcium deficient hydroxyapatite (CDHA nanoparticles has been developed. Antibacterial ions such as zinc, silver and strontium have been incorporated into CDHA at concentrations of 6 at. %, 0.25-0.75 at. % and 2.5-7.5 at. % respectively. The samples were found to be phase pure, acicular nanoparticles of length 40-50 nm and width 5-6 nm approximately. The loading and release profile of doxycycline, a commonly used antibiotic, was studied from the nanocarriers. The drug release was studied for five days and the release profile was influenced by the ion concentrations. The release of antibacterial ions was studied over a period of 21 days. The ion substituted CDHA samples were tested for antibacterial efficacy on S.aureus and E.coli by MIC/MBC studies and time-kill assay. AgCDHA and ZnCDHA showed high antibacterial activity against both bacteria while SrCDHA was weakly active against S.aureus. Present study shows that the antibiotic release can provide the initial high antibacterial activity and the sustained ion release can provide a long-term antibacterial activity. Such dual mode antibiotic and antibacterial ion release offers an efficient and potent way to treat an incumbent drug

The dual of the Carroll-Field-Jackiw model

International Nuclear Information System (INIS)

Guimaraes, M.S.; Grigorio, L.; Wotzasek, C.

2006-01-01

In this work we apply different duality techniques, both the dual projection, based on the soldering formalism and the master action, in order to obtain and study the dual description of the Carroll- Field-Jackiw model [1], a theory with a Chern-Simons-like explicitly Lorentz and CPT violating term, including the interaction with external charges. This Maxwell-Chern-Simons-like model may be rewritten in terms of the interacting modes of a massless scalar model and a topologically massive model [2], that are mapped, through duality, into interacting massless Maxwell and massive self-dual modes [3]. It is also shown that these dual modes might be represented into an unified rank-two self-dual model that represents the direct dual of the vector Maxwell-Chern-Simons-like model

Clinical usefulness of catheter-drawn blood samples and catheter tip cultures for the diagnosis of catheter-related bloodstream infections in neonatology: A systematic review.

Science.gov (United States)

Ferreira, Janita; Camargos, Paulo Augusto Moreira; Clemente, Wanessa Trindade; Romanelli, Roberta Maia de Castro

2018-01-01

Neonatal sepsis is the most frequent health care-associated infection in neonatal units. This study aimed to analyze articles on the clinical usefulness of catheter-drawn blood samples and catheter tip cultures for the diagnosis of intravascular catheter-related bloodstream infection (CRBSI) in neonates. A systematic search was performed for studies published from 1987-2017, without language restriction. Observational studies carried out in neonates with CRBSI diagnosed using catheter-drawn blood samples or catheter tip cultures were included. A total of 412 articles were identified in the databases and 10 articles were included. The 7 studies that evaluated central venous catheter tip cultures and cultures of catheter fragments presented sensitivities ranging from 58.5%-100% and specificities ranging from 60%-95.7%. Three studies that evaluated catheter-drawn blood cultures, paired with peripheral blood cultures, reported sensitivity and specificity of 94% and 71% when evaluated for the differential time to positivity. When quantitative evaluation was performed, the sensitivity and specificity were 80% and 99.4%. Most of the studies analyzed cultures from the central venous catheter tip and catheter fragments for the diagnosis of CRBSI in neonatal populations. The results of this review suggest that the analysis of the catheter-drawn blood samples and catheter tip cultures, paired with peripheral blood cultures, are efficient methods for the diagnosis of CRBSI in neonates. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

PERFORMANCE, EMISSION, AND COMBUSTION CHARACTERISTICS OF A CI ENGINE USING LIQUID PETROLEUM GAS AND NEEM OIL IN DUAL FUEL MODE

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Palanimuthu Vijayabalan

2010-01-01

Full Text Available Increased environmental awareness and depletion of resources are driving the industries to develop viable alternative fuels like vegetable oils, compresed natural gas, liquid petroleum gas, producer gas, and biogas in order to provide suitable substitute to diesel for compression ignition engine. In this investigation, a single cylinder, vertical, air-cooled diesel engine was modified to use liquid petroleum gas in dual fuel mode. The liquefied petroleum gas, was mixed with air and supplied through intake manifold. The liquid fuel neem oil or diesel was injected into the combustion chamber. The performance, emission, and combustion characteristics were studied and compared for neat fuel and dual fuel mode. The experimental results on dual fuel engine show a reduction in oxides of nitrogen up to 70% of the rated power and smoke in the entire power range. However the brake thermal efficiency was found decreased in low power range due to lower calorific value of liquid petroleum gas, and increase in higher power range due to the complete burning of liquid petroleum gas. Hydrocarbon and carbon monoxide emissions were increased significantly at lower power range and marginal variation in higher power range.

Dedicated radial ventriculography pigtail catheter

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Vidovich, Mladen I., E-mail: miv@uic.edu

2013-05-15

A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

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... cause is determined and is referred to as “secondary” intracranial hypertension. What are the risk factors for idiopathic intracranial ... clotting disorders, anemia and malnutrition. Can idiopathic intracranial ... to be “secondary” which affects males and females equally. The second ...

Catheter Angiography

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Full Text Available ... is injected through the catheter and reaches the blood vessels being studied, several sets of x-rays are taken. Then the catheter is removed and the incision site is closed by applying pressure on the area for approximately 10 to 20 ...

Ultrasound as a Screening Tool for Central Venous Catheter Positioning and Exclusion of Pneumothorax.

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Amir, Rabia; Knio, Ziyad O; Mahmood, Feroze; Oren-Grinberg, Achikam; Leibowitz, Akiva; Bose, Ruma; Shaefi, Shahzad; Mitchell, John D; Ahmed, Muneeb; Bardia, Amit; Talmor, Daniel; Matyal, Robina

2017-07-01

Although real-time ultrasound guidance during central venous catheter insertion has become a standard of care, postinsertion chest radiograph remains the gold standard to confirm central venous catheter tip position and rule out associated lung complications like pneumothorax. We hypothesize that a combination of transthoracic echocardiography and lung ultrasound is noninferior to chest radiograph when used to accurately assess central venous catheter positioning and screen for pneumothorax. All operating rooms and surgical and trauma ICUs at the institution. Single-center, prospective noninferiority study. Patients receiving ultrasound-guided subclavian or internal jugular central venous catheters. During ultrasound-guided central venous catheter placement, correct positioning of central venous catheter was accomplished by real-time visualization of the guide wire and positive right atrial swirl sign using the subcostal four-chamber view. After insertion, pneumothorax was ruled out by the presence of lung sliding and seashore sign on M-mode. Data analysis was done for 137 patients. Chest radiograph ruled out pneumothorax in 137 of 137 patients (100%). Lung ultrasound was performed in 123 of 137 patients and successfully screened for pneumothorax in 123 of 123 (100%). Chest radiograph approximated accurate catheter tip position in 136 of 137 patients (99.3%). Adequate subcostal four-chamber views could not be obtained in 13 patients. Accurate positioning of central venous catheter with ultrasound was then confirmed in 121 of 124 patients (97.6%) as described previously. Transthoracic echocardiography and lung ultrasound are noninferior to chest x-ray for screening of pneumothorax and accurate central venous catheter positioning. Thus, the point of care use of ultrasound can reduce central venous catheter insertion to use time, exposure to radiation, and improve patient safety.

FACTORS AND COMPLICATIONS AFFECTING CATHETER AND TECHNIQUE SURVIVAL WITH PERMANENT SINGLE-LUMEN DIALYSIS CATHETERS

NARCIS (Netherlands)

DEMEESTER, J; VANHOLDER, R; DEROOSE, J; RINGOIR, S

1994-01-01

This long-term study on the outcome of permanent silicone single-lumen dialysis catheters consisted of 43 surgically inserted catheters in 33 patients. All catheters were attached to a pressure-pressure single-cannula dialysis system. Technique and catheter survival were 80 and 59% at 1 year, and 63

An ovine model of cerebral catheter venography for implantation of an endovascular neural interface.

Science.gov (United States)

Oxley, Thomas James; Opie, Nicholas Lachlan; Rind, Gil Simon; Liyanage, Kishan; John, Sam Emmanuel; Ronayne, Stephen; McDonald, Alan James; Dornom, Anthony; Lovell, Timothy John Haynes; Mitchell, Peter John; Bennett, Iwan; Bauquier, Sebastien; Warne, Leon Norris; Steward, Chris; Grayden, David Bruce; Desmond, Patricia; Davis, Stephen M; O'Brien, Terence John; May, Clive N

2018-04-01

OBJECTIVE Neural interface technology may enable the development of novel therapies to treat neurological conditions, including motor prostheses for spinal cord injury. Intracranial neural interfaces currently require a craniotomy to achieve implantation and may result in chronic tissue inflammation. Novel approaches are required that achieve less invasive implantation methods while maintaining high spatial resolution. An endovascular stent electrode array avoids direct brain trauma and is able to record electrocorticography in local cortical tissue from within the venous vasculature. The motor area in sheep runs in a parasagittal plane immediately adjacent to the superior sagittal sinus (SSS). The authors aimed to develop a sheep model of cerebral venography that would enable validation of an endovascular neural interface. METHODS Cerebral catheter venography was performed in 39 consecutive sheep. Contrast-enhanced MRI of the brain was performed on 13 animals. Multiple telescoping coaxial catheter systems were assessed to determine the largest wide-bore delivery catheter that could be delivered into the anterior SSS. Measurements of SSS diameter and distance from the motor area were taken. The location of the motor area was determined in relation to lateral and superior projections of digital subtraction venography images and confirmed on MRI. RESULTS The venous pathway from the common jugular vein (7.4 mm) to the anterior SSS (1.2 mm) was technically challenging to selectively catheterize. The SSS coursed immediately adjacent to the motor cortex (SSS. Attempted access with 5-Fr and 6-Fr delivery catheters was associated with longer procedure times and higher complication rates. A 4-Fr catheter (internal lumen diameter 1.1 mm) was successful in accessing the SSS in 100% of cases with no associated complications. Complications included procedure-related venous dissection in two major areas: the torcular herophili, and the anterior formation of the SSS. The

Intracranial atherosclerosis: current concepts.

Science.gov (United States)

Arenillas, Juan F

2011-01-01

The most relevant ideas discussed in this article are described here. Intracranial atherosclerotic disease (ICAD) represents the most common cause of ischemic stroke worldwide. Its importance in whites may have been underestimated. New technical developments, such as high-resolution MRI, allow direct assessment of the intracranial atherosclerotic plaque, which may have a profound impact on ICAD diagnosis and therapy in the near future. Early detection of ICAD may allow therapeutic intervention while the disease is still asymptomatic. The Barcelonès Nord and Maresme Asymptomatic Intracranial Atherosclerosis Study is presented here. The main prognostic factors that characterize the patients who are at a higher risk for ICAD recurrence are classified and discussed. The best treatment for ICAD remains to be established. The Stenting Versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis Study is currently ongoing to address this crucial issue. These and other topics will be discussed at the Fifth International Intracranial Atherosclerosis Conference (Valladolid, Spain, autumn 2011).

Dual-mode nested search method for categorical uncertain multi-objective optimization

Science.gov (United States)

Tang, Long; Wang, Hu

2016-10-01

Categorical multi-objective optimization is an important issue involved in many matching design problems. Non-numerical variables and their uncertainty are the major challenges of such optimizations. Therefore, this article proposes a dual-mode nested search (DMNS) method. In the outer layer, kriging metamodels are established using standard regular simplex mapping (SRSM) from categorical candidates to numerical values. Assisted by the metamodels, a k-cluster-based intelligent sampling strategy is developed to search Pareto frontier points. The inner layer uses an interval number method to model the uncertainty of categorical candidates. To improve the efficiency, a multi-feature convergent optimization via most-promising-area stochastic search (MFCOMPASS) is proposed to determine the bounds of objectives. Finally, typical numerical examples are employed to demonstrate the effectiveness of the proposed DMNS method.

Realization of Current Mode Universal Filter and a Dual-Mode Single Resistance Controlled Quadrature Oscillator Employing VDCC and Only Grounded Passive Elements

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Manish Gupta

2017-01-01

Full Text Available The manuscript presents a circuit that can act as a universal filter as well as a single resistence controlled oscillator by unpretentiously changing the switch positions. The circuit employs only two active devices and all grounded passive elements. The utilization of only grounded passive components makes this circuit a better choice for integrated circuit implementation. The current mode biquadratic filter offers all the five basic responses along with independent tunability of its quality factor. The dual-mode quadrature sinusoidal oscillator offers explicit current outputs along with voltage outputs. The circuit also offers a simple and uncoupled condition of oscillation and frequency of oscillation. The typical analysis such as non-ideal, sensitivity and parasitic analysis along with the regular simulation results as well as experimental results are exposed here, to strengthen the design idea.

NOISY INTRACRANIAL TUMORS

NARCIS (Netherlands)

VANDOOREN, BTH; VANBRUGGEN, AC; MOOIJ, JJA; HEW, JM; JOURNEE, HL

1994-01-01

Transorbital sound recordings were obtained from 21 patients with intracranial tumours, 28 patients with intracranial aneurysms and 20 control patients. The group of patients with tumours consisted of 12 patients with gliomas, of whom 6 had low-grade gliomas and 6 had high-grade gliomas, and 9

In situ, dual-mode monitoring of organ-on-a-chip with smartphone-based fluorescence microscope.

Science.gov (United States)

Cho, Soohee; Islas-Robles, Argel; Nicolini, Ariana M; Monks, Terrence J; Yoon, Jeong-Yeol

2016-12-15

The use of organ-on-a-chip (OOC) platforms enables improved simulation of the human kidney's response to nephrotoxic drugs. The standard method of analyzing nephrotoxicity from existing OOC has majorly consisted of invasively collecting samples (cells, lysates, media, etc.) from an OOC. Such disruptive analyses potentiate contamination, disrupt the replicated in vivo environment, and require expertize to execute. Moreover, traditional analyses, including immunofluorescence microscopy, immunoblot, and microplate immunoassay are essentially not in situ and require substantial time, resources, and costs. In the present work, the incorporation of fluorescence nanoparticle immunocapture/immunoagglutination assay into an OOC enabled dual-mode monitoring of drug-induced nephrotoxicity in situ. A smartphone-based fluorescence microscope was fabricated as a handheld in situ monitoring device attached to an OOC. Both the presence of γ-glutamyl transpeptidase (GGT) on the apical brush-border membrane of 786-O proximal tubule cells within the OOC surface, and the release of GGT to the outflow of the OOC were evaluated with the fluorescence scatter detection of captured and immunoagglutinated anti-GGT conjugated nanoparticles. This dual-mode assay method provides a novel groundbreaking tool to enable the internal and external in situ monitoring of the OOC, which may be integrated into any existing OOCs to facilitate their subsequent analyses. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasound Imaging of Mouse Fetal Intracranial Hemorrhage Due to Ischemia/Reperfusion

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Kenichi Funamoto

2017-05-01

Full Text Available Despite vast improvement in perinatal care during the 30 years, the incidence rate of neonatal encephalopathy remains unchanged without any further Progress towards preventive strategies for the clinical impasse. Antenatal brain injury including fetal intracranial hemorrhage caused by ischemia/reperfusion is known as one of the primary triggers of neonatal injury. However, the mechanisms of antenatal brain injury are poorly understood unless better predictive models of the disease are developed. Here we show a mouse model for fetal intracranial hemorrhage in vivo developed to investigate the actual timing of hypoxia-ischemic events and their related mechanisms of injury. Intrauterine growth restriction mouse fetuses were exposed to ischemia/reperfusion cycles by occluding and opening the uterine and ovarian arteries in the mother. The presence and timing of fetal intracranial hemorrhage caused by the ischemia/reperfusion were measured with histological observation and ultrasound imaging. Protein-restricted diet increased the risk of fetal intracranial hemorrhage. The monitoring of fetal brains by ultrasound B-mode imaging clarified that cerebral hemorrhage in the fetal brain occurred after the second ischemic period. Three-dimensional ultrasound power Doppler imaging visualized the disappearance of main blood flows in the fetal brain. These indicate a breakdown of cerebrovascular autoregulation which causes the fetal intracranial hemorrhage. This study supports the fact that the ischemia/reperfusion triggers cerebral hemorrhage in the fetal brain. The present method enables us to noninvasively create the cerebral hemorrhage in a fetus without directly touching the body but with repeated occlusion and opening of the uterine and ovarian arteries in the mother.

Dual-mode optical microscope based on single-pixel imaging

Science.gov (United States)

Rodríguez, A. D.; Clemente, P.; Tajahuerce, E.; Lancis, J.

2016-07-01

We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.

Bacillus Cereus catheter related bloodstream infection in a patient in a patient with acute lymphblastic leukemia

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Lütfiye Öksüz

2012-01-01

Full Text Available

Bacillus cereus infection is rarely associated with actual infection and for this reason single positive blood culture is usually regarded as contamination . However it may cause a number of infections, such catheter-related blood stream infections. Significant catheter-related bloodstream infections (CRBSI caused by Bacillus spp. are mainly due to B.cereus and have been predominantly reported in immunocompromised hosts¹ . Catheter removal is generally advised for management of infection. In this report, catheter-related bacteremia caused by B.cereus in a patient with acute lymphoblastıc leukemia (ALL in Istanbul Medical Faculty was presented.A 44-year old man presented with fatigue, weight loss, epistaxis and high fever. A double-lumen Hickman–catheter (Bard 12.0 Fr, Round Dual Lumen was inserted by surgical cut-down to access the right subclavian vein which would be necessary for allogeneic stem cell transplantation. Three weeks later the patient presented with high fever and headache. Bacillus spp. was isolated from the cathether while blood culture obtained from the peripheral vein remained negative. The bacterial identification was confirmed as B.cereus using VITEK identification system

It has been reported Bacillus cereus septicemia may be fatal in immunocompromised hosts despite broad-spectrum appropriate treatment¹⁰. Catheter removal is essential for prevention of recurrent bacteremia. Long-term cathater salvage should be reserved for appropriate patient group.

MR imaging and MR angiography in preoperative evaluation of intracranial meningiomas

International Nuclear Information System (INIS)

Goldmann, A.; Kunz, U.; Bader, C.; Leibing, U.; Friedrich, J.M.; Oldenkott, P.

1994-01-01

A group of 41 patients with intracranial meningiomas were examined by MR imaging (MRI) and MR angiography (MRA) to assess the clinical value of MRA in the preoperative evaluation of these patients. The results of MRA were compared with the results of intraarterial cerebral catheter X-ray angiography (XRA; n 19) and with the operative findings (n = 41). Our results showed a good correlation between MRA and XRA/surgery in demonstrating the relationship between the tumor and adjacent venous and arterial structures. Use of MRA was also helpful in demonstrating the degree of intrinsic tumor vascularity. It also supplied important information for operative planning. Adjunct XRA was mandatory if detailed information about tumor-feeding vessels was requested by the neurosurgeon, especially in highly vascularized angiomatous meningiomas and in meningiomas suspected of tumor feeding by vessels of the internal carotid artery. (orig.)

MR imaging and MR angiography in preoperative evaluation of intracranial meningiomas

Energy Technology Data Exchange (ETDEWEB)

Goldmann, A. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Kunz, U. [Dept. of Neurosurgery, Military Hospital, Academic Hospital of the University, Ulm (Germany); Bader, C. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Leibing, U. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Friedrich, J.M. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Oldenkott, P. [Dept. of Neurosurgery, Military Hospital, Academic Hospital of the University, Ulm (Germany)

1994-12-01

A group of 41 patients with intracranial meningiomas were examined by MR imaging (MRI) and MR angiography (MRA) to assess the clinical value of MRA in the preoperative evaluation of these patients. The results of MRA were compared with the results of intraarterial cerebral catheter X-ray angiography (XRA; n = 19) and with the operative findings (n = 41). Our results showed a good correlation between MRA and XRA/surgery in demonstrating the relationship between the tumor and adjacent venous and arterial structures. Use of MRA was also helpful in demonstrating the degree of intrinsic tumor vascularity. It also supplied important information for operative planning. Adjunct XRA was mandatory if detailed information about tumor-feeding vessels was requested by the neurosurgeon, especially in highly vascularized angiomatous meningiomas and in meningiomas suspected of tumor feeding by vessels of the internal carotid artery. (orig.)

Terminalia Chebula provides protection against dual modes of necroptotic and apoptotic cell death upon death receptor ligation.

Science.gov (United States)

Lee, Yoonjung; Byun, Hee Sun; Seok, Jeong Ho; Park, Kyeong Ah; Won, Minho; Seo, Wonhyoung; Lee, So-Ra; Kang, Kidong; Sohn, Kyung-Cheol; Lee, Ill Young; Kim, Hyeong-Geug; Son, Chang Gue; Shen, Han-Ming; Hur, Gang Min

2016-04-27

Death receptor (DR) ligation elicits two different modes of cell death (necroptosis and apoptosis) depending on the cellular context. By screening a plant extract library from cells undergoing necroptosis or apoptosis, we identified a water extract of Terminalia chebula (WETC) as a novel and potent dual inhibitor of DR-mediated cell death. Investigation of the underlying mechanisms of its anti-necroptotic and anti-apoptotic action revealed that WETC or its constituents (e.g., gallic acid) protected against tumor necrosis factor-induced necroptosis via the suppression of TNF-induced ROS without affecting the upstream signaling events. Surprisingly, WETC also provided protection against DR-mediated apoptosis by inhibition of the caspase cascade. Furthermore, it activated the autophagy pathway via suppression of mTOR. Of the WETC constituents, punicalagin and geraniin appeared to possess the most potent anti-apoptotic and autophagy activation effect. Importantly, blockage of autophagy with pharmacological inhibitors or genetic silencing of Atg5 selectively abolished the anti-apoptotic function of WETC. These results suggest that WETC protects against dual modes of cell death upon DR ligation. Therefore, WETC might serve as a potential treatment for diseases characterized by aberrantly sensitized apoptotic or non-apoptotic signaling cascades.

The effects of voice and manual control mode on dual task performance

Science.gov (United States)

Wickens, C. D.; Zenyuh, J.; Culp, V.; Marshak, W.

1986-01-01

Two fundamental principles of human performance, compatibility and resource competition, are combined with two structural dichotomies in the human information processing system, manual versus voice output, and left versus right cerebral hemisphere, in order to predict the optimum combination of voice and manual control with either hand, for time-sharing performance of a dicrete and continuous task. Eight right handed male subjected performed a discrete first-order tracking task, time-shared with an auditorily presented Sternberg Memory Search Task. Each task could be controlled by voice, or by the left or right hand, in all possible combinations except for a dual voice mode. When performance was analyzed in terms of a dual-task decrement from single task control conditions, the following variables influenced time-sharing efficiency in diminishing order of magnitude, (1) the modality of control, (discrete manual control of tracking was superior to discrete voice control of tracking and the converse was true with the memory search task), (2) response competition, (performance was degraded when both tasks were responded manually), (3) hemispheric competition, (performance degraded whenever two tasks were controlled by the left hemisphere) (i.e., voice or right handed control). The results confirm the value of predictive models invoice control implementation.

Impact of short-term hemodialysis catheters on the central veins: a catheter venographic study

Energy Technology Data Exchange (ETDEWEB)

Oguzkurt, Levent E-mail: loguzkurt@yahoo.com; Tercan, Fahri; Torun, Dilek; Yildirim, Tuelin; Zuemruetdal, Ayseguel; Kizilkilic, Osman

2004-12-01

Objective: To determine the incidence of pericatheter sleeve formation, thrombus formation, and stenosis of the central veins in hemodialysis patients with temporary catheters. Methods and material: In this prospective study, 57 patients (40 males, 17 females) with temporary dialysis catheters had catheter venography by pulling back the catheter just before removal. Patient's age range was 25-87 years (mean age, 51 years). The venographic studies were evaluated for pericatheter sleeve formation, thrombus formation, and stenosis of the brachiocephalic vein (BCV) and the superior vena cava (SVC). The IJV could only be evaluated if there was adequate filling during contrast administration. In a subgroup of patients who had had only right IJV or only right SCV catheters, impact of these catheters on the central veins was compared. Results: The catheter location was right internal jugular vein (IJV) in 26 cases, right subclavian vein (SCV) in 27 cases, left IJV in 1 case, and left SCV in 3 cases. Thirty-two patients (56%) had had only one temporary catheter and the rest had had more than one inserted. The mean dwell time for the catheters was 21 days (range 7-59 days). A pericatheter sleeve was detected on venography in 32 (56%) patients and thrombus formation was noted in 16 patients (28%). A total of 41 patients (72%) exhibited pericatheter sleeve and/or thrombus formation. While 19 of the 32 patients (59%) without previous catheterization had a sleeve around the catheter, only 13 (52%) of 25 patients who had had multiple catheters inserted had a sleeve (P>0.05). Of the eight patients (14%) with BCV stenosis, two had >50% stenosis. Only one patient (2%) had mild stenosis of the SVC. Three patients out of 15 (20%) who had diagnostic venography for the IJV had severe stenosis of the vein. Pericatheter sleeve formation was more frequent in women (P<0.05). However, there were no statistical differences with respect to pericatheter sleeve formation, luminal filling

Concurrent use of pigtail and loop snare catheters for percutaneous retrieval of dislodged central venous port catheter

Directory of Open Access Journals (Sweden)

Ming-Tsung Chuang

2011-11-01

Full Text Available The purpose of this study was to report our experience of percutaneous retrieval of dislodged port catheters with concurrent use of pigtail and loop snare catheters. During a 5-year period at our institute (June 2005 to July 2010, a total of 23 dislodged port catheters were retrieved. The interval between port catheter implantation and dislodged catheter retrieval ranged from 43 days to 1,414 days (mean 586.7 days. The time of delayed retrieval ranged from 1 day to 45 days (mean 4.6 days. All dislodged catheters were retrieved with the concurrent use of pigtail and loop snare catheters via femoral venous route. The prevalence of port catheter dislodgement at our institute was 3.4%. All dislodged port catheters were removed successfully with pigtail and loop snare catheters together. No procedure-related complications were encountered, except for transient arrhythmia in two patients, which required no medication. In conclusion, the concurrent use of pigtail and loop snare catheters is a feasible and easy way for percutaneous retrieval of a dislodged central venous port catheter.

TROPICS 1: a phase III, randomized, double-blind, placebo-controlled study of tenecteplase for restoration of function in dysfunctional central venous catheters.

Science.gov (United States)

Gabrail, Nashat; Sandler, Eric; Charu, Veena; Anas, Nick; Lim, Eduardo; Blaney, Martha; Ashby, Mark; Gillespie, Barbara S; Begelman, Susan M

2010-12-01

To evaluate the efficacy and safety of the thrombolytic tenecteplase, a fibrin-specific recombinant tissue plasminogen activator, for restoring function to dysfunctional central venous catheters (CVCs). In this double-blind, placebo-controlled study, eligible patients with dysfunctional nonhemodialysis CVCs were randomly assigned to two treatment arms. In the first arm (TNK-TNK-PBO), patients received an initial dose of intraluminal tenecteplase (TNK) (up to 2 mg), a second dose of tenecteplase if indicated, and a third placebo (PBO) dose. In the PBO-TNK-TNK arm, placebo was instilled first followed by up to two doses of tenecteplase, if needed, for restoration of catheter function. After administration of each dose, CVC function was assessed at 15, 30, and 120 minutes. There were 97 patients who received either TNK-TNK-PBO (n = 50) or PBO-TNK-TNK (n = 47). Within 120 minutes of initial study drug instillation, catheter function was restored to 30 patients (60%) in the TNK-TNK-PBO arm and 11 patients (23%) in the PBO-TNK-TNK arm, for a treatment difference of 37 percentage points (95% confidence interval 18-55; P = .0002). Cumulative restoration rates for CVC function increased to 87% after the second dose of tenecteplase in both study arms combined. Two patients developed a deep vein thrombosis (DVT) after exposure to tenecteplase; one DVT was considered to be drug related. No cases of intracranial hemorrhage, major bleeding, embolic events, catheter-related bloodstream infections, or catheter-related complications were reported. Tenecteplase was efficacious for restoration of catheter function in these study patients with dysfunctional CVCs. Copyright © 2010 SIR. Published by Elsevier Inc. All rights reserved.

The efficacy of noble metal alloy urinary catheters in reducing catheter-associated urinary tract infection

Directory of Open Access Journals (Sweden)

Alanood Ahmed Aljohi

2016-01-01

Results: A 90% relative risk reduction in the rate of CAUTI was observed with the noble metal alloy catheter compared to the standard catheter (10 vs. 1 cases, P = 0.006. When considering both catheter-associated asymptomatic bacteriuria and CAUTI, the relative risk reduction was 83% (12 vs. 2 cases, P = 0.005. In addition to CAUTI, the risk of acquiring secondary bacteremia was lower (100% for the patients using noble metal alloy catheters (3 cases in the standard group vs. 0 case in the noble metal alloy catheter group, P = 0.24. No adverse events related to any of the used catheters were recorded. Conclusion: Results from this study revealed that noble metal alloy catheters are safe to use and significantly reduce CAUTI rate in ICU patients after 3 days of use.

Button self-retaining drainage catheter

International Nuclear Information System (INIS)

Caridi, James G.; Hawkins, Irvin F.; Akins, E. William; Young, Ronald S.

1997-01-01

To help improve patient acceptance of long-term internal/external catheter access to the biliary tract in those with benign biliary obstruction, a simple design allows the catheter end to remain flush with the skin. It consists of a clothes button affixed to the drainage catheter with a wood screw after the catheter has been cut off at the skin exit. This button/screw device has been used successfully in 22 patients over the last 10 years; catheter exchanges were easily accomplished

Intracranial Hemorrhage

Science.gov (United States)

2011-01-01

Intracranial hemorrhage is a life-threatening condition, the outcome of which can be improved by intensive care. Intracranial hemorrhage may be spontaneous, precipitated by an underlying vascular malformation, induced by trauma, or related to therapeutic anticoagulation. The goals of critical care are to assess the proximate cause, minimize the risks of hemorrhage expansion through blood pressure control and correction of coagulopathy, and obliterate vascular lesions with a high risk of acute rebleeding. Simple bedside scales and interpretation of computed tomography scans assess the severity of neurological injury. Myocardial stunning and pulmonary edema related to neurological injury should be anticipated, and can usually be managed. Fever (often not from infection) is common and can be effectively treated, although therapeutic cooling has not been shown to improve outcomes after intracranial hemorrhage. Most functional and cognitive recovery takes place weeks to months after discharge; expected levels of functional independence (no disability, disability but independence with a device, dependence) may guide conversations with patient representatives. Goals of care impact mortality, with do-not-resuscitate status increasing the predicted mortality for any level of severity of intraparenchymal hemorrhage. Future directions include refining the use of bedside neuromonitoring (electroencephalogram, invasive monitors), novel approaches to reduce intracranial hemorrhage expansion, minimizing vasospasm, and refining the assessment of quality of life to guide rehabilitation and therapy. PMID:22167847

A tuneable, power efficient and narrow single longitudinal mode fibre ring laser using an inline dual-taper fibre Mach–Zehnder filter

International Nuclear Information System (INIS)

Ahmad, H; Dernaika, M; Alimadad, M; Ibrahim, M F; Lim, K S; Harun, S W; Kharraz, O M

2014-01-01

A tuneable single longitudinal mode fibre ring laser with dual-taper fibre filter is proposed and experimentally demonstrated in this paper. The single longitudinal mode operation, and power limitations for a Mach–Zehnder interferometer filter generated from a single mode fibre, are verified for the first time. Incorporating an in-line taper fibre Mach–Zehnder interferometer filter inside the laser ring cavity causes a spatial mode beating interference, resulting in a passive narrow band filter with the ability to generate stable single longitudinal modes. The single longitudinal mode achieves a side mode suppression ratio of more than 60 dB using low pump power. The tuneability of the fibre laser ranges from 1525 to 1562 nm using a passive band pass filter. A study of the stability and limitation of the single longitudinal mode in the Mach–Zehnder tapered fibre is also presented. (paper)

Dual-channel amplification in a single-mode diode laser for multi-isotope laser cooling

International Nuclear Information System (INIS)

Booth, James L.; Van Dongen, Janelle; Lebel, Paul; Klappauf, Bruce G.; Madison, Kirk W.

2007-01-01

The output from two grating-stabilized external-cavity diode lasers were injected into a single-mode diode laser. Operating at a wavelength of 780 nm, this laser produced ∼50 mW of power with two main frequency components of the same spectral characteristics of the seed lasers. The power ratio of the amplified components was freely adjustable due to gain saturation, and amplification was observed for frequency differences of the two seed lasers in the range from 73 MHz to 6.6 GHz. This system was used to realize a dual isotope magneto-optic trap (MOT) for rubidium ( 85 Rb and 87 Rb). The resulting position and cloud size of the dual isotope MOT was the same as that of the single species MOTs to within ±10 and ±20 μm, respectively. We also characterized the additional spectral components produced by four wave mixing (FWM) in the diode laser amplifier and utilized a particular FWM sideband to realize hyperfine pumping and subsequent laser trapping of 85 Rb in the absence of a 'repump' laser dedicated to hyperfine pumping

Complications of central venous stenosis due to permanent central venous catheters in children on hemodialysis.

Science.gov (United States)

Rinat, Choni; Ben-Shalom, Efrat; Becker-Cohen, Rachel; Feinstein, Sofia; Frishberg, Yaacov

2014-11-01

Central venous catheters are frequently used as access for hemodialysis (HD) in children. One of the known complications is central venous stenosis. Although this complication is not rare, it is often asymptomatic and therefore unacknowledged. Superior vena cava (SVC) stenosis is obviously suspected in the presence of upper body edema, but several other signs and symptoms are often unrecognized as being part of this syndrome. We describe four patients with various manifestations of central venous stenosis and SVC syndrome. These sometimes life- or organ-threatening conditions include obstructive sleep apnea, unresolving stridor, increased intracranial pressure, increased intraocular pressure, right-sided pleural effusion, protein-losing enteropathy and lymphadenopathy. The temporal relationship of these complications associated with the use of central venous catheters and documentation of venous stenosis, together with their resolution after alleviation of high venous pressure, points to a causal role. We suggest pathophysiological mechanisms for the formation of each of these complications. In patients with occlusion of the SVC, various unexpected clinical entities can be caused by high central venous pressure. As often the etiology is not obvious, a high index of suspicion is needed as in some cases prompt alleviation of the high pressure is mandatory.

Feasibility of a dual regime gyrotron

International Nuclear Information System (INIS)

Sawant, Ashwini; Jain, Prerit; Kartikeyan, M.V.

2012-01-01

The design concept of a 42/84 GHz, 500 kW, CW, dual-regime gyrotron for ECRH of plasma in an experimental Tokamak will be presented in this paper. Operation at 42 GHz is fundamental where as that in 84 GHz will be second harmonic so that a similar guidance system will be retained for dual regime operation. In this paper, the mode competition and mode selection procedures are presented for such a dual regime operation. Cold cavity design and self-consistent calculations will be carried out for power and efficiencies. (author)

Understanding idiopathic intracranial hypertension

DEFF Research Database (Denmark)

Markey, Keira A; Mollan, Susan P; Jensen, Rigmor H

2016-01-01

Idiopathic intracranial hypertension is a disorder characterised by raised intracranial pressure that predominantly affects young, obese women. Pathogenesis has not been fully elucidated, but several causal factors have been proposed. Symptoms can include headaches, visual loss, pulsatile tinnitus...

Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure

Science.gov (United States)

Zhao, Bo; Li, Yuanchun

2015-01-01

This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations. PMID:26181826

Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure.

Directory of Open Access Journals (Sweden)

Bo Zhao

Full Text Available This paper considers a decentralized fault tolerant control (DFTC scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO. Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations.

Large-area, uniform and low-cost dual-mode plasmonic naked-eye colorimetry and SERS sensor with handheld Raman spectrometer.

Science.gov (United States)

Xu, Zhida; Jiang, Jing; Wang, Xinhao; Han, Kevin; Ameen, Abid; Khan, Ibrahim; Chang, Te-Wei; Liu, Gang Logan

2016-03-21

We demonstrated a highly-sensitive, wafer-scale, highly-uniform plasmonic nano-mushroom substrate based on plastic for naked-eye plasmonic colorimetry and surface-enhanced Raman spectroscopy (SERS). We gave it the name FlexBrite. The dual-mode functionality of FlexBrite allows for label-free qualitative analysis by SERS with an enhancement factor (EF) of 10(8) and label-free quantitative analysis by naked-eye colorimetry with a sensitivity of 611 nm RIU(-1). The SERS EF of FlexBrite in the wet state was found to be 4.81 × 10(8), 7 times stronger than in the dry state, making FlexBrite suitable for aqueous environments such as microfluid systems. The label-free detection of biotin-streptavidin interaction by both SERS and colorimetry was demonstrated with FlexBrite. The detection of trace amounts of the narcotic drug methamphetamine in drinking water by SERS was implemented with a handheld Raman spectrometer and FlexBrite. This plastic-based dual-mode nano-mushroom substrate has the potential to be used as a sensing platform for easy and fast analysis in chemical and biological assays.

Spontaneous intracranial hypotension.

LENUS (Irish Health Repository)

Fullam, L

2012-01-31

INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

Dual-mode endomicroscopy for detection of epithelial dysplasia in the mouth: a descriptive pilot study

Science.gov (United States)

Bodenschatz, Nico; Poh, Catherine F.; Lam, Sylvia; Lane, Pierre; Guillaud, Martial; MacAulay, Calum E.

2017-08-01

Dual-mode endomicroscopy is a diagnostic tool for early cancer detection. It combines the high-resolution nuclear tissue contrast of fluorescence endomicroscopy with quantified depth-dependent epithelial backscattering as obtained by diffuse optical microscopy. In an in vivo pilot imaging study of 27 oral lesions from 21 patients, we demonstrate the complementary diagnostic value of both modalities and show correlations between grade of epithelial dysplasia and relative depth-dependent shifts in light backscattering. When combined, the two modalities provide diagnostic sensitivity to both moderate and severe epithelial dysplasia in vivo.

A Dual-Mode UWB Wireless Platform with Random Pulse Length Detection for Remote Patient Monitoring

DEFF Research Database (Denmark)

Reyes, Carlos; Bisbe, Sergi; Shen, Ming

2013-01-01

on a single hardware platform, but it is capable of both monitoring and data transmission. This is achieved by employing a new random pulse length detection method that allows data transmission by using a modulated monitoring signal. To prove the proposed concept a test system has been built, using commercial......This paper presents a dual-mode ultra-wideband platform for wireless Remote Patient Monitoring (RPM). Existing RPM solutions are typically based on two different hardware platforms; one responsible for medical-data monitoring and one to handle data transmission. The proposed RPM topology is based...

Assessment of blood supply to intracranial pathologies in children using MR digital subtraction angiography

Energy Technology Data Exchange (ETDEWEB)

Chooi, Weng Kong; Coley, Stuart C. [Royal Hallamshire Hospital, Department of Radiology, Sheffield (United Kingdom); Connolly, Dan J.A. [Royal Hallamshire Hospital, Department of Radiology, Sheffield (United Kingdom); Sheffield Children' s Hospital, Department of Radiology, Sheffield (United Kingdom); Griffiths, Paul D. [Royal Hallamshire Hospital, Department of Radiology, Sheffield (United Kingdom); Sheffield Children' s Hospital, Department of Radiology, Sheffield (United Kingdom); University of Sheffield, Academic Unit of Radiology, Sheffield (United Kingdom); Floor C, Royal Hallamshire Hospital, Section of Academic Radiology, Sheffield (United Kingdom)

2006-10-15

MR digital subtraction angiography (MR-DSA) is a contrast-enhanced MR angiographic sequence that enables time-resolved evaluation of the cerebral circulation. We describe the feasibility and technical success of our attempts at MR-DSA for the assessment of intracranial pathology in children. We performed MR-DSA in 15 children (age range 5 days to 16 years) referred for MR imaging because of known or suspected intracranial pathology that required a dynamic assessment of the cerebral vasculature. MR-DSA consisted of a thick (6-10 mm) slice-selective RF-spoiled fast gradient-echo sequence (RF-FAST) acquired before and during passage of an intravenously administered bolus of Gd-DTPA. The images were subtracted and viewed as a cine loop. MR-DSA was performed successfully in all patients. High-flow lesions were shown in four patients; these included vein of Galen aneurysmal malformation, dural fistula, and two partially treated arteriovenous malformations (AVMs). Low-flow lesions were seen in three patients, all of which were tumours. Normal flow was confirmed in eight patients including two with successfully treated AVMs, and in three patients with cavernomas. Our early experience suggests that MR-DSA is a realistic, non-invasive alternative to catheter angiography in certain clinical settings. (orig.)

Assessment of blood supply to intracranial pathologies in children using MR digital subtraction angiography

International Nuclear Information System (INIS)

Chooi, Weng Kong; Coley, Stuart C.; Connolly, Dan J.A.; Griffiths, Paul D.

2006-01-01

MR digital subtraction angiography (MR-DSA) is a contrast-enhanced MR angiographic sequence that enables time-resolved evaluation of the cerebral circulation. We describe the feasibility and technical success of our attempts at MR-DSA for the assessment of intracranial pathology in children. We performed MR-DSA in 15 children (age range 5 days to 16 years) referred for MR imaging because of known or suspected intracranial pathology that required a dynamic assessment of the cerebral vasculature. MR-DSA consisted of a thick (6-10 mm) slice-selective RF-spoiled fast gradient-echo sequence (RF-FAST) acquired before and during passage of an intravenously administered bolus of Gd-DTPA. The images were subtracted and viewed as a cine loop. MR-DSA was performed successfully in all patients. High-flow lesions were shown in four patients; these included vein of Galen aneurysmal malformation, dural fistula, and two partially treated arteriovenous malformations (AVMs). Low-flow lesions were seen in three patients, all of which were tumours. Normal flow was confirmed in eight patients including two with successfully treated AVMs, and in three patients with cavernomas. Our early experience suggests that MR-DSA is a realistic, non-invasive alternative to catheter angiography in certain clinical settings. (orig.)

Assessment of blood supply to intracranial pathologies in children using MR digital subtraction angiography.

Science.gov (United States)

Chooi, Weng Kong; Connolly, Dan J A; Coley, Stuart C; Griffiths, Paul D

2006-10-01

MR digital subtraction angiography (MR-DSA) is a contrast-enhanced MR angiographic sequence that enables time-resolved evaluation of the cerebral circulation. We describe the feasibility and technical success of our attempts at MR-DSA for the assessment of intracranial pathology in children. We performed MR-DSA in 15 children (age range 5 days to 16 years) referred for MR imaging because of known or suspected intracranial pathology that required a dynamic assessment of the cerebral vasculature. MR-DSA consisted of a thick (6-10 mm) slice-selective RF-spoiled fast gradient-echo sequence (RF-FAST) acquired before and during passage of an intravenously administered bolus of Gd-DTPA. The images were subtracted and viewed as a cine loop. MR-DSA was performed successfully in all patients. High-flow lesions were shown in four patients; these included vein of Galen aneurysmal malformation, dural fistula, and two partially treated arteriovenous malformations (AVMs). Low-flow lesions were seen in three patients, all of which were tumours. Normal flow was confirmed in eight patients including two with successfully treated AVMs, and in three patients with cavernomas. Our early experience suggests that MR-DSA is a realistic, non-invasive alternative to catheter angiography in certain clinical settings.

Intracranial arterial stenosis.

Science.gov (United States)

Carvalho, Marta; Oliveira, Ana; Azevedo, Elsa; Bastos-Leite, António J

2014-04-01

Intracranial arterial stenosis (IAS) is usually attributable to atherosclerosis and corresponds to the most common cause of stroke worldwide. It is very prevalent among African, Asian, and Hispanic populations. Advancing age, systolic hypertension, diabetes mellitus, high levels of low-density lipoprotein cholesterol, and metabolic syndrome are some of its major risk factors. IAS may be associated with transient or definite neurological symptoms or can be clinically asymptomatic. Transcranial Doppler and magnetic resonance angiography are the most frequently used ancillary examinations for screening and follow-up. Computed tomography angiography can either serve as a screening tool for the detection of IAS or increasingly as a confirmatory test approaching the diagnostic accuracy of catheter digital subtraction angiography, which is still considered the gold (confirmation) standard. The risk of stroke in patients with asymptomatic atherosclerotic IAS is low (up to 6% over a mean follow-up period of approximately 2 years), but the annual risk of stroke recurrence in the presence of a symptomatic stenosis may exceed 20% when the degree of luminal narrowing is 70% or more, recently after an ischemic event, and in women. It is a matter of controversy whether there is a specific type of treatment other than medical management (including aggressive control of vascular risk factors and antiplatelet therapy) that may alter the high risk of stroke recurrence among patients with symptomatic IAS. Endovascular treatment has been thought to be helpful in patients who fail to respond to medical treatment alone, but recent data contradict such expectation. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Catheter-directed thrombolytic therapy for thoracic deep vein thrombosis is safe and effective in selected patients with and without cancer

International Nuclear Information System (INIS)

Maleux, Geert; Marchal, Pieter; Heye, Sam; Vaninbroukx, Johan; Palmers, Marleen; Verhamme, Peter; Verhaeghe, Raymond

2010-01-01

To assess the safety, feasibility and efficacy of catheter-directed thrombolysis for thoracic central venous thrombosis in both cancer and non-cancer patients. A retrospective case series of 68 patients, including 35 with active cancer and 33 without cancer, was analysed. They all received catheter-directed thrombolysis with alteplase or urokinase for symptomatic acute major thoracic vein thrombosis. Substantial clot lysis was obtained in 62 out of 68 patients (91%), the results being 88.6 and 93.8% for cancer and non-cancer patients respectively (P = 0.68). The mean infusion time in patients with and without cancer was 2.11 and 1.84 days respectively (P = 0.3259). Procedure-related complications occurred in two cancer patients (8.6%) and in seven non-cancer patients (21%) (P = 0.18). One cancer patient developed a fatal intracranial bleeding. Additional intervention after successful lysis was performed in cancer (n = 18; 51%) as well as in non-cancer patients (n = 29; 88%). Catheter-directed thrombolysis is a feasible and highly effective interventional procedure with an acceptable safety profile in selected patients with and without cancer for the treatment of symptomatic thoracic central venous thrombosis. In most cases, additional endovascular or surgical procedures are required to restore and maintain vessel patency after successful thrombolysis. (orig.)

Highly coherent free-running dual-comb chip platform.

Science.gov (United States)

Hébert, Nicolas Bourbeau; Lancaster, David G; Michaud-Belleau, Vincent; Chen, George Y; Genest, Jérôme

2018-04-15

We characterize the frequency noise performance of a free-running dual-comb source based on an erbium-doped glass chip running two adjacent mode-locked waveguide lasers. This compact laser platform, contained only in a 1.2 L volume, rejects common-mode environmental noise by 20 dB thanks to the proximity of the two laser cavities. Furthermore, it displays a remarkably low mutual frequency noise floor around 10  Hz 2 /Hz, which is enabled by its large-mode-area waveguides and low Kerr nonlinearity. As a result, it reaches a free-running mutual coherence time of 1 s since mode-resolved dual-comb spectra are generated even on this time scale. This design greatly simplifies dual-comb interferometers by enabling mode-resolved measurements without any phase lock.

Exploring relationships of catheter-associated urinary tract infection and blockage in people with long-term indwelling urinary catheters.

Science.gov (United States)

Wilde, Mary H; McMahon, James M; Crean, Hugh F; Brasch, Judith

2017-09-01

To describe and explore relationships among catheter problems in long-term indwelling urinary catheter users, including excess healthcare use for treating catheter problems. Long-term urinary catheter users experience repeated problems with catheter-related urinary tract infection and blockage of the device, yet little has been reported of the patterns and relationships among relevant catheter variables. Secondary data analysis was conducted from a sample in a randomised clinical trial, using data from the entire sample of 202 persons over 12 months' participation. Descriptive statistics were used to characterise the sample over time. Zero-inflated negative binomial models were employed for logistic regressions to evaluate predictor variables of the presence/absence and frequencies of catheter-related urinary tract infection and blockage. Catheter-related urinary tract infection was marginally associated with catheter blockage. Problems reported at least once per person in the 12 months were as follows: catheter-related urinary tract infection 57%, blockage 34%, accidental dislodgment 28%, sediment 87%, leakage (bypassing) 67%, bladder spasms 59%, kinks/twists 42% and catheter pain 49%. Regression analysis demonstrated that bladder spasms were significantly related to catheter-related urinary tract infection and sediment amount, and catheter leakages were marginally significantly and positively related to catheter-related urinary tract infection. Frequencies of higher levels of sediment and catheter leakage were significantly associated with higher levels of blockage, and being female was associated with fewer blockages. Persons who need help with eating (more disabled) were also more likely to have blockages. Catheter-related urinary tract infection and blockage appear to be related and both are associated with additional healthcare expenditures. More research is needed to better understand how to prevent adverse catheter outcomes and patterns of problems in

Robust equivalent consumption-based controllers for a dual-mode diesel parallel HEV

International Nuclear Information System (INIS)

Finesso, Roberto; Spessa, Ezio; Venditti, Mattia

2016-01-01

Highlights: • Non-plug-in dual-mode parallel hybrid architecture. • Cross-validation machine-learning for robust equivalent consumption-based controllers. • Optimal control strategy based on fuel consumption, NOx and battery aging. • Impact of different equivalent consumption definitions on HEV performance. • Correlation between vehicle braking energy and SOC variation in the traction stages. - Abstract: New equivalent consumption minimization strategy (ECMS) tools have been developed and applied to identify the optimal control strategy of a dual-mode parallel hybrid electric vehicle equipped with a compression-ignition engine. In this architecture, the electric machine is coupled to the engine through either a single-speed gearbox (torque-coupling) or a planetary gear set (speed-coupling). One of the main novelties of the present study concerns the definition of the instantaneous equivalent consumption (EC) function, which takes into account not only fuel consumption (FC) and the energy flow through the electric components, but also NO_x emissions, battery aging, and the battery SOC. The EC function has been trained using a cross-validation machine-learning technique, based on a genetic algorithm, where the training data set has been selected in order to maximize performances over a testing data set. The adoption of this technique, in conjunction with the new definition of EC, have led to the identification of very robust controllers, which provide an accurate control for different driving scenarios, even when the EC function is not specifically trained on the same missions over which it is tested. To this aim, a data set of fifty driving cycles and six user-defined missions, which cover a total distance of 70–100 km, has been considered as a training driving set. The ECMS controllers can be implemented in a vehicle control unit, and their performance has resulted to be close to that of a dynamic programming tool, which has here been used as benchmark

Automated intracranial pressure-controlled cerebrospinal fluid external drainage with LiquoGuard.

Science.gov (United States)

Linsler, Stefan; Schmidtke, Mareike; Steudel, Wolf Ingo; Kiefer, Michael; Oertel, Joachim

2013-08-01

LiquoGuard is a new device for intracranial pressure (ICP)-controlled drainage of cerebrospinal fluid (CSF). This present study evaluates the accuracy of ICP measurement via the LiquoGuard device in comparison with Spiegelberg. Thus, we compared data ascertained from simultaneous measurement of ICP using tip-transducer and tip-sensor devices. A total of 1,764 monitoring hours in 15 patients (range, 52-219 h) were analysed. All patients received an intraventricular Spiegelberg III probe with the drainage catheter connected to the LiquoGuard system. ICP reading of both devices was performed on an hourly basis. Statistical analysis was done by applying Pearson correlation and Wilcoxon-matched pair test (p drainage. However, LiquoGuard tends to provide misleading results in slit ventricles. Thus, before these drawbacks are further analysed, the authors recommend additional ICP measurement with internal tip-sensor devices to avoid dangerous erroneous interpretation of ICP data.

Intracranial chondroma: a rare entity.

Science.gov (United States)

Maheshwari, Veena; Mehdi, Ghazala; Varshney, Manoranjan; Jain, Anshu; Vashishtha, Sonal; Gaur, Kavita; Srivastava, Vinod Kumar

2011-05-12

Intracranial chondroma is a rare benign cartilaginous tumour with an incidence of less than 1% of all primary intracranial tumours. The authors are reporting here a case of intracranial chondroma in a 40-year-old man who presented with 5-month history of headache and gradual diminution of vision. A tentative diagnosis of chondroma was made on imprint cytology which was confirmed on histopathological examination.

Intracranial hemorrhage due to intracranial hypertension caused by the superior vena cava syndrome

DEFF Research Database (Denmark)

Bartek, Jiri; Abedi-Valugerdi, Golbarg; Liska, Jan

2013-01-01

We report a patient with intracranial hemorrhage secondary to venous hypertension as a result of a giant aortic pseudoaneurysm that compressed the superior vena cava and caused obstruction of the venous return from the brain. To our knowledge, this is the first patient reported to have...... an intracranial hemorrhage secondary to a superior vena cava syndrome. The condition appears to be caused by a reversible transient rise in intracranial pressure, as a result of compression of the venous return from the brain. Treatment consisted of surgery for the aortic pseudoaneurysm, which led...

Diagnostic value of optical coherence tomography for intracranial pressure in idiopathic intracranial hypertension

DEFF Research Database (Denmark)

Skau, M; Yri, H; Sander, B

2013-01-01

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a condition of raised intracranial pressure (ICP) in the absence of space-occupying lesions or other known etiology. It primarily affects young obese females, and potentially causes permanent visual loss due to papilledema and secondary...... optic atrophy. The aim of this study was to evaluate the diagnostic value of optical coherence tomography (OCT) as a marker for CSF opening pressure in patients with idiopathic intracranial hypertension (IIH). METHODS: We conducted a case-control study of 20 newly diagnosed, 21 long-term IIH patients...

Sex differences in intracranial arterial bifurcations

DEFF Research Database (Denmark)

Lindekleiv, Haakon M; Valen-Sendstad, Kristian; Morgan, Michael K

2010-01-01

Subarachnoid hemorrhage (SAH) is a serious condition, occurring more frequently in females than in males. SAH is mainly caused by rupture of an intracranial aneurysm, which is formed by localized dilation of the intracranial arterial vessel wall, usually at the apex of the arterial bifurcation. T....... The female preponderance is usually explained by systemic factors (hormonal influences and intrinsic wall weakness); however, the uneven sex distribution of intracranial aneurysms suggests a possible physiologic factor-a local sex difference in the intracranial arteries....

Peritoneal catheter fixation combined with straight upward tunnel and low implant position to prevent catheter malfunction.

Science.gov (United States)

Zhang, Qingyan; Jiang, Chunming; Zhu, Wei; Sun, Cheng; Xia, Yangyang; Tang, Tianfeng; Wan, Cheng; Shao, Qiuyuan; Liu, Jing; Jin, Bo; Zhang, Miao

2018-03-01

Catheter malfunction is the main reason for early peritoneal dialysis (PD) technique failure. This study aimed to evaluate the effect of a new surgery technique with catheter fixation to the lower abdominal wall combined with straight upward tunnel and low implant position in reducing catheter malfunction. Patients with end stage renal disease who received PD in our centre from January 2013 to December 2015 were involved in this study. They were randomly divided into three groups according to surgical technique: traditional open surgery group, modified open surgery group and modified open surgery with catheter fixation group. All patients were followed up for six months after surgery. Catheter- related complications were analyzed. A total of 152 patients were involved. Among them, 49 received traditional open surgery (TOS group), 49 received modified open surgery (MOS group), and 54 received modified open surgery with catheter fixation (MOS-F group). During follow-up, no patients (0%) in MOS-F group developed catheter malfunction which was significantly lower than that of the TOS group (0 vs 16.33%, P = 0.002). Although not statistically significant, the incidence of catheter malfunction was lower in MOS-F group than that in MOS group (0 vs 4.08%, P = 0.134). No significant difference was observed in the episodes of infection, bleeding, leakage, inflow or outflow pain, hernia and delayed wound healing among the three groups (all P > 0.05). Catheter fixation combined with straight upward tunnel and low implant position can effectively prevent catheter malfunction in PD catheter placement. © 2016 Asian Pacific Society of Nephrology.

[The role of the uretral catheter in the development of catheter- related urinary tract infection].

Science.gov (United States)

Vasilyev, A O; Govorov, A V; Shiryaev, A A; Pushkar, D Yu

2017-12-01

The most common source of nosocomial infection is the urinary tract, especially if they it is drained with a urethral catheter. Catheter-associated urinary tract infections account for at least 80% of all complicated urinary tract infections and are the most common type of hospital-acquired infection. Intestinal microflora plays the leading role in the pathogenesis of catheter-associated urinary tract infections, whereas the most important risk factor for their development is the long duration of urinary catheter drainage. In the case of short-term and intermittent catheterization, routine antibiotic prophylaxis is not required, but if a patient develops clinically significant infection, antibiotic therapy is required followed by definitive therapy based on culture. Urethral catheters coated with antimicrobial substances and anti-inflammatory agents can significantly reduce the adhesion and migration of bacteria, thereby reducing the incidence of urinary tract infections. Despite this, the incidence of catheter-associated infection remains high. We have reviewed recent literature related to catheter-associated urinary tract infections and the best means of preventing this condition.

Three cases of intracranial lipoma

Energy Technology Data Exchange (ETDEWEB)

Kurokawa, Hiroyuki; Kikuchi, Kenji; Yanagida, Noritaka; Fujii, Satoshi; Watanabe, Kazuo; Miyauchi, Takaharu

1987-12-01

Intracranial lipoma is an uncommon lesion that can be found in both symptomatic and asymptomatic patients. Because of CT (computerized tomography), the tumors can now be easily diagnosed in asymptomatic individuals. Three cases of intracranial lipoma in asymptomatic patients are presented, along with a review of the literature, and the value of CT, especially coronal section, in the diagnosis of intracranial lipomas and associated anomalies, such as the agenesis of corpus callosum, is discussed.

Epidural Catheter Breakage In-Situ

Directory of Open Access Journals (Sweden)

Geetanjali S Verma

2014-09-01

Full Text Available A 45yr old woman diagnosed with dysfunctional uterine bleeding and incisional hernia was planned for total abdominal hysterectomy with bilateral salpingo-oophorectomy and mesh repair under combined spinal and epidural anaesthesia. Using VYGON® epidural catheter with its recommended introducer, the catheter was inserted but it snapped off at 11cm mark while positioning the catheter. After radiological confirmation, the neurosurgeon removed the catheter under general anaesthesia, which was followed by the scheduled surgery.

Intracranial sarcoidosis

International Nuclear Information System (INIS)

Seltzer, S.; Mark, A.S.; Atlas, S.W.

1989-01-01

The appearance of intracranial sarcoidosis on Gd-DTPA-enhanced MR imaging has not been previously reported. The authors have studied five patients with T1-and T2-weighted pre-GD and T1-weighted post-GD sequences. Images showed diffuse meningeal involvement suspected on the unenhanced scans in only one patient, enhancing extraaxial masses mimicking meningiomas, and enhancing and nonenhancing intraaxial lesions. In four of five patients, the diagnosis of intracranial sarcoidosis was suggested only after Gd-DTPA administration. The addition of Gd-DTPA greatly enhanced the sensitivity of MR imaging to the extraaxial and meningeal manifestations of central nervous system sarcoidosis

Combining monoenergetic extrapolations from dual-energy CT with iterative reconstructions. Reduction of coil and clip artifacts from intracranial aneurysm therapy

Energy Technology Data Exchange (ETDEWEB)

Winklhofer, Sebastian; Baltsavias, Gerasimos; Michels, Lars; Valavanis, Antonios [University of Zurich, Department of Neuroradiology, University Hospital Zurich, Zurich (Switzerland); Hinzpeter, Ricarda; Stocker, Daniel; Alkadhi, Hatem [University of Zurich, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich (Switzerland); Burkhardt, Jan-Karl; Regli, Luca [University of Zurich, Department of Neurosurgery, University Hospital Zurich, Zurich (Switzerland)

2018-03-15

To compare and to combine iterative metal artifact reduction (MAR) and virtual monoenergetic extrapolations (VMEs) from dual-energy computed tomography (DECT) for reducing metal artifacts from intracranial clips and coils. Fourteen clips and six coils were scanned in a phantom model with DECT at 100 and 150SnkVp. Four datasets were reconstructed: non-corrected images (filtered-back projection), iterative MAR, VME from DECT at 120 keV, and combined iterative MAR + VME images. Artifact severity scores and visibility of simulated, contrast-filled, adjacent vessels were assessed qualitatively and quantitatively by two independent, blinded readers. Iterative MAR, VME, and combined iterative MAR + VME resulted in a significant reduction of qualitative (p < 0.001) and quantitative clip artifacts (p < 0.005) and improved the visibility of adjacent vessels (p < 0.05) compared to non-corrected images, with lowest artifact scores found in combined iterative MAR + VME images. Titanium clips demonstrated less artifacts than Phynox clips (p < 0.05), and artifact scores increased with clip size. Coil artifacts increased with coil size but were reducible when applying iterative MAR + VME compared to non-corrected images. However, no technique improved the severe artifacts from large, densely packed coils. Combining iterative MAR with VME allows for an improved metal artifact reduction from clips and smaller, loosely packed coils. Limited value was found for large and densely packed coils. (orig.)

High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

OpenAIRE

Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

2015-01-01

Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 ...

Dual-mode gradient HPLC procedure for the simultaneous determination of chloroquine and proguanil.

Science.gov (United States)

Paci, A; Caire-Maurisier, A-M; Rieutord, A; Brion, F; Clair, P

2002-01-01

In order to assay the antipaludic capsule of the Service de Santé des Armées (SSA), that contains two antimalarial drugs, i.e. chloroquine sulfate (CQS, cp1) and proguanil hydrochloride (PGH, cp5), a HPLC procedure was developed. A reversed-phase ion-pair high-performance liquid chromatography (HPLC) method with an ultraviolet detection at 254 nm was set up and validated. Elution system includes programming of both organic concentration and flow-rate known as 'dual-mode gradient'. This method allows the simultaneous determination of both active compounds and separation of four process related substances. The method is simple, rapid, selective and accurate, and the precision is good with an inter- and intra-assay of <2%. The sensitivity is particularly suitable for pharmaceutical quality control.

Monitoring and guidance of HIFU beams with dual-mode ultrasound arrays.

Science.gov (United States)

Ballard, John R; Casper, Andrew J; Ebbini, Emad S

2009-01-01

We present experimental results illustrating the unique advantages of dual-mode array (DMUA) systems in monitoring and guidance of high intensity focused ultrasound (HIFU) lesion formation. DMUAs offer a unique paradigm in image-guided surgery; one in which images obtained using the same therapeutic transducer provide feedback for: 1) refocusing the array in the presence of strongly scattering objects, e.g. the ribs, 2) temperature change at the intended location of the HIFU focus, and 3) changes in the echogenicity of the tissue in response to therapeutic HIFU. These forms of feedback have been demonstrated in vitro in preparation for the design and implementation of a real-time system for imaging and therapy with DMUAs. The results clearly demonstrate that DMUA image feedback is spatially accurate and provide sufficient spatial and contrast resolution for identification of high contrast objects like the ribs and significant blood vessels in the path of the HIFU beam.

Tracing Fasting Glucose Fluxes with Unstressed Catheter Approach in Streptozotocin Induced Diabetic Rats

Directory of Open Access Journals (Sweden)

Shichun Du

2014-01-01

Full Text Available Objective. Blood glucose concentrations of type 1 diabetic rats are vulnerable, especially to stress and trauma. The present study aimed to investigate the fasting endogenous glucose production and skeletal muscle glucose uptake of Streptozotocin induced type 1 diabetic rats using an unstressed vein and artery implantation of catheters at the tails of the rats as a platform. Research Design and Methods. Streptozotocin (65 mg·kg−1 was administered to induce type 1 diabetic state. The unstressed approach of catheters of vein and artery at the tails of the rats was established before the isotope tracer injection. Dynamic measurement of fasting endogenous glucose production was assessed by continuously infusing stable isotope [6, 6-2H2] glucose, while skeletal muscle glucose uptake by bolus injecting radioactively labeled [1-14C]-2-deoxy-glucose. Results. Streptozotocin induced type 1 diabetic rats displayed polydipsia, polyphagia, and polyuria along with overt hyperglycemia and hypoinsulinemia. They also had enhanced fasting endogenous glucose production and reduced glucose uptake in skeletal muscle compared to nondiabetic rats. Conclusions. The dual catheters implantation at the tails of the rats together with isotope tracers injection is a save time, unstressed, and feasible approach to explore the glucose metabolism in animal models in vivo.

Intracranial calcification in central diabetes insipidus

International Nuclear Information System (INIS)

Al-Kandari, Salwa R.; Pandey, Tarun; Badawi, Mona H.

2008-01-01

Intracranial calcification is a known but extremely rare complication of diabetes insipidus. To date, only 16 patients have been reported and all had the peripheral (nephrogenic) type of diabetes insipidus. We report a child with intracranial calcification complicating central diabetes insipidus. We also report a child with nephrogenic diabetes insipidus, and compare the patterns of intracranial calcification. (orig.)

Intracranial calcification in central diabetes insipidus

Energy Technology Data Exchange (ETDEWEB)

Al-Kandari, Salwa R. [Al Razi Hospital, Department of Clinical Radiology, Kuwait (Kuwait); Pandey, Tarun [Al Razi Hospital, Department of Clinical Radiology, Kuwait (Kuwait); University of Arkansas for Medical Sciences, Radiology Department, Little Rock, AR (United States); Badawi, Mona H. [Al-Adan Hospital, Department of Paediatrics, Kuwait (Kuwait)

2008-01-15

Intracranial calcification is a known but extremely rare complication of diabetes insipidus. To date, only 16 patients have been reported and all had the peripheral (nephrogenic) type of diabetes insipidus. We report a child with intracranial calcification complicating central diabetes insipidus. We also report a child with nephrogenic diabetes insipidus, and compare the patterns of intracranial calcification. (orig.)

Fatigue Failure Modes of the Grain Size Transition Zone in a Dual Microstructure Disk

Science.gov (United States)

Gabb, Timothy P.; Kantzos, Pete T.; Palsa, Bonnie; Telesman, Jack; Gayda, John; Sudbrack, Chantal K.

2012-01-01

Mechanical property requirements vary with location in nickel-based superalloy disks. In order to maximize the associated mechanical properties, heat treatment methods have been developed for producing tailored grain microstructures. In this study, fatigue failure modes of a grain size transition zone in a dual microstructure disk were evaluated. A specialized heat treatment method was applied to produce varying grain microstructure in the bore to rim portions of a powder metallurgy processed nickel-based superalloy disk. The transition in grain size was concentrated in a zone of the disk web, between the bore and rim. Specimens were extracted parallel and transversely across this transition zone, and multiple fatigue tests were performed at 427 C and 704 C. Grain size distributions were characterized in the specimens, and related to operative failure initiation modes. Mean fatigue life decreased with increasing maximum grain size, going out through the transition zone. The scatter in limited tests of replicates was comparable for failures of uniform gage specimens in all transition zone locations examined.

Vascular access in neonatology: peripherally inserted central catheter and peripheral venous catheter

Directory of Open Access Journals (Sweden)

Marcia Lienemann

2014-04-01

The objective of this paper is to present aspects of peripherally inserted central catheter and peripheral venous catheter, highlighting important points in choosing the type of access. For the passage of peripherally inserted central catheter is previously performing specific course necessary, while the primary indication occurs when it is necessary to access the patient's stay for a long period of time. Whereas peripheral venipuncture is the most appropriate in cases of needing an IV line quickly and safely, for the administration of fluids, blood collection, blood transfusion and other.

Emergency coronary angioplasty with stenting using Cordis® diagnostic coronary catheters when there is difficulty in engaging guide catheters and bench evaluation of diagnostic and guide catheters.

Science.gov (United States)

Arokiaraj, Mark Christopher

2018-02-01

Difficulty in engaging with guide catheters is not uncommon in acute emergencies. We aimed to evaluate the use of Cordis ® INFINITI diagnostic catheters to perform angioplasty in patients in whom the coronaries cannot be engaged using standard guide catheters. In 34 cases of acute coronary syndrome, when difficulty in engagement with two standard guide catheters was encountered with reasonable manipulations, angioplasty was performed using diagnostic catheters. In total, 40 stents were placed by this technique. Pushability and trackability, distal tip flexion and three-point bending tests were performed to evaluate the performance of the guide and diagnostic catheters. Angioplasty was performed easily in a setting where it would have been very difficult to perform. Coronary dissection occurred in one patient, treated by a stent. The stent and dilatation balloons were easily passed through the diagnostic catheters. Pressure tracings were clearly preserved with certain stent delivery systems, and at angioplasty, although there was slightly reduced opacification of the respective artery, the coronary anatomy was sufficiently visualized to perform angioplasty. No periprocedural target lesion complications were seen in any cases. Pushability and trackability tests showed good force transmission along a tortuous path with diagnostic catheters, and balanced force-displacement curves from three-point bending tests and distal tip softness tests. Angioplasty with stenting can be performed safely through 6F Cordis ® infiniti diagnostic catheters when difficulty in engaging guide catheters is encountered. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Stent-assisted recanalization of atherosclerotic intracranial stenosis

International Nuclear Information System (INIS)

Soo Mee Lim; Dae Chul Suh

2006-01-01

Intracranial atherosclerosis is a major cause of ischemic stroke, and depending on the studied population, it accounts for 8%-15% of all strokes that are due to cerebral atherosclerosis. The prognosis of patients with symptomatic intracranial stenoses seems to depend on the location and extent of intracranial atherosclerosis. Currently, the primary treatment in intracranial atherosclerosis is the control of vascular risk factors such as hypertension, diabetes, hypercholesterolemia, and smoking. Secondary prevention with antiplatelet therapy has been shown to reduce the risk of subsequent vascular events in patients who have suffered a recent ischemic stroke or transient ischemic attack (TIA). Unfortunately, a significant number of patients with intracranial atherosclerosis continue to suffer from repeated strokes or TIA despite maximal medical treatment. Although endovascular revascularization for symptomatic intracranial stenoses remains at the investigational stage and much of the pertinent information is anecdotal, intracranial angioplasty and stenting are being increasingly performed to treat stenotic lesions. This article reviews basic principles involved in the patient selection, premedication, angio-interventional procedures, angiographic and clinical results, periprocedural complication, patients aftercare. (authors)

Intracorporeal knotting of a femoral nerve catheter

Directory of Open Access Journals (Sweden)

Ghanem, Mohamed

2015-01-01

Full Text Available Peripheral nerve catheters are effective and well-established tools to provide postoperative analgesia to patients undergoing orthopedic surgery. The performance of these techniques is usually considered safe. However, placement of nerve catheters may be associated with a considerable number of side effects and major complications have repeatedly been published. In this work, we report on a patient who underwent total knee replacement with spinal anesthesia and preoperative insertion of femoral and sciatic nerve catheters for postoperative analgesia. During insertion of the femoral catheter, significant resistance was encountered upon retracting the catheter. This occurred due to knotting of the catheter. The catheter had to be removed by operative intervention which has to be considered a major complication. The postoperative course was uneventful. The principles for removal of entrapped peripheral catheters are not well established, may differ from those for neuroaxial catheters, and range from cautious manipulation up to surgical intervention.

Idiopathic intracranial hypertension

DEFF Research Database (Denmark)

Yri, Hanne M; Jensen, Rigmor H

2015-01-01

AIMS: The aims of this article are to characterize the headache in idiopathic intracranial hypertension (IIH) and to field-test the ICHD diagnostic criteria for headache attributed to IIH. MATERIALS AND METHODS: We included 44 patients with new-onset IIH. Thirty-four patients with suspected but u...... tinnitus may suggest intracranial hypertension. Based on data from a well-defined IIH cohort, we propose a revision of the ICDH-3 beta diagnostic criteria with improved clinical applicability and increased sensitivity and specificity....

Radiologic placement of Hickman catheters

International Nuclear Information System (INIS)

Robertson, L.J.; Mauro, M.A.; Jaques, P.F.

1988-01-01

Hickman catheter inserter has previously been predominantly accomplished surgically by means of venous cutdown or percutaneous placement in the operating room. The authors describe their method and results for 55 consecutive percutaneous placements of Hickman catheters in the interventional radiology suite. Complication rates were comparable to those for surgical techniques. Radiologic placement resulted in increased convenience, decreased time and cost of insertion, and super fluoroscopic control of catheter placement and any special manipulations. Modern angiographic materials provide safer access to the subclavian vein than traditional methods. The authors conclude that radiologic placement of Hickman catheters offers significant advantages over traditional surgical placement

Comparative study of peripherally inserted central venous catheter and traditional central catheter assisted with X-ray

International Nuclear Information System (INIS)

Yu Jianchun; Wang Xiurong; Jiang Zhuming

1999-01-01

Objective: To study the feasibility, complications, mid- and long-term advantages of peripherally inserted central catheters (PICC) compared with central venous access assisted with X-ray. Methods: From Jan 1997 to Dec 1998, the authors conducted a study in 60 patients with placed PICC lines and 60 patients with central lines. Study variables included tip placement and complication rates. Results: Tere were on significant differences between PICC and CVC in the successful placement 95.0% and 88.3%, t = 1.745, P 0.19; the mean duration 13(6-98) days and 14 (7-104) days, F = 0.049, P = 0.83; the total occlusion rate 6.7% (4/60) and 5.0%(3/60), t = 0.152, P = 0.70. In PICC patients, the occlusion rate was slightly higher in 3 Fr (20-gauge) catheter (3/20, 15.0%) than in 4 Fr(18-gauge) catheters (1/20, 5.0%), t = 1.111, P=0.29. Phlebitis occurred in 5.0% of patients (3/60) and one catheter fracture was happened on the catheter hub junction (1.7%). In 3 catheter tips dislocation cases, the catheter tips were moved to the optional position assisted with X-ray image. In CVC group, pneumothorax happened in 1 case (1.7%). In 4 catheter dislocation cases, the catheters were with drawn. No catheter-related sepsis and hemo-pneumothorax happened in both group patients. Conclusions: Both PICC and CVC can be acceptable in clinical use. PICC assisted with X-ray possesses the advantages of less trauma, accurate localization preventing some possible severe complications of central venous access such as pneumothorax. The new method provides a reliable, effective venous access for mid-and long-term usage in patients receiving a variety of solutions, primarily parenteral alimentation, chemotherapy or antibiotic infusion

Spontaneous intracranial hemorrhage and multiple intracranial aneurysms in a patient with Roberts/SC phocomelia syndrome.

Science.gov (United States)

Wang, Anthony C; Gemmete, Joseph J; Keegan, Catherine E; Witt, Cordelie E; Muraszko, Karin M; Than, Khoi D; Maher, Cormac O

2011-11-01

Roberts/SC phocomelia syndrome (RBS) is a rare but distinct genetic disorder with an autosomal recessive inheritance pattern. It has been associated with microcephaly, craniofacial malformation, cavernous hemangioma, encephalocele, and hydrocephalus. There are no previously reported cases of RBS with intracranial aneurysms. The authors report on a patient with a history of RBS who presented with a spontaneous posterior fossa hemorrhage. Multiple small intracranial aneurysms were noted on a preoperative CT angiogram. The patient underwent emergency craniotomy for evacuation of the hemorrhage. A postoperative angiogram confirmed the presence of multiple, distal small intracranial aneurysms.

Intracranial tuberculoma: MR imaging

Energy Technology Data Exchange (ETDEWEB)

Salgado, P; Zenteno, M A; Rodriguez-Carbajal, J; Brutto, O.H. del; Talamas, O

1989-09-01

MR studies of 6 patients with intracranial tuberculoma are reviewed. All patients also underwent CT scans which showed hypo- or isodense lesions with abnormal enhancement following contrast administration. MR showed lesions with prolongation of the T1 relaxation time in every case. On the T2-weighted sequences, the signal properties of the tuberculoma varied according to the stage of evolution of the lesion. Incipient tuberculomas appeared as scattered areas of hypointensity surrounded by edema. Mature tuberculomas were composed of a dark necrotic center surrounded by an isointense capsule which was, in turn, surrounded by edema. In one patient, the center of the lesion was hyperintense probably because of liquefaction and pus formation (tuberculous abscess). While both, CT and MR, were equally sensitive in visualizing the intracranial tuberculoma in every patient, MR was slightly superior in demonstrating the extent of the lesion, especially for brainstem tuberculomas. Nevertheless, the potential role for MR diagnosis of intracranial tuberculoma is limited by the fact that other infectious or neoplasic diseases may present similar findings. The diagnosis of intracranial tuberculoma should rest on a proper integration of data from clinical manifestations, cerebrospinal fluid analysis, and neuroimaging studies. (orig.).

Intracranial tuberculoma: MR imaging

International Nuclear Information System (INIS)

Salgado, P.; Zenteno, M.A.; Rodriguez-Carbajal, J.; Brutto, O.H. del; Talamas, O.

1989-01-01

MR studies of 6 patients with intracranial tuberculoma are reviewed. All patients also underwent CT scans which showed hypo- or isodense lesions with abnormal enhancement following contrast administration. MR showed lesions with prolongation of the T1 relaxation time in every case. On the T2-weighted sequences, the signal properties of the tuberculoma varied according to the stage of evolution of the lesion. Incipient tuberculomas appeared as scattered areas of hypointensity surrounded by edema. Mature tuberculomas were composed of a dark necrotic center surrounded by an isointense capsule which was, in turn, surrounded by edema. In one patient, the center of the lesion was hyperintense probably because of liquefaction and pus formation (tuberculous abscess). While both, CT and MR, were equally sensitive in visualizing the intracranial tuberculoma in every patient, MR was slightly superior in demonstrating the extent of the lesion, especially for brainstem tuberculomas. Nevertheless, the potential role for MR diagnosis of intracranial tuberculoma is limited by the fact that other infectious or neoplasic diseases may present similar findings. The diagnosis of intracranial tuberculoma should rest on a proper integration of data from clinical manifestations, cerebrospinal fluid analysis, and neuroimaging studies. (orig.)

Observation of stable bound soliton with dual-wavelength in a passively mode-locked Er-doped fiber laser

International Nuclear Information System (INIS)

Zheng Yu; Tian Jin-Rong; Dong Zi-Kai; Xu Run-Qin; Li Ke-Xuan; Song Yan-Rong

2017-01-01

A phase-locked bound state soliton with dual-wavelength is observed experimentally in a passively mode-locked Er-doped fiber (EDF) laser with a fiber loop mirror (FLM). The pulse duration of the soliton is 15 ps and the peak-to-peak separation is 125 ps. The repetition rate of the pulse sequence is 3.47 MHz. The output power is 11.8 mW at the pump power of 128 mW, corresponding to the pulse energy of 1.52 nJ. The FLM with a polarization controller can produce a comb spectrum, which acts as a filter. By adjusting the polarization controller or varying the pump power, the central wavelength of the comb spectrum can be tuned. When it combines with the reflective spectrum of the fiber Bragg grating, the total spectrum of the cavity can be cleaved into two parts, then the bound state soliton with dual-wavelength at 1549.7 nm and 1550.4 nm is obtained. (paper)

Ultrasonographic Findings of Fetal Congenital Intracranial Teratoma

Energy Technology Data Exchange (ETDEWEB)

Lee, Hak Jong [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Young Ho; Song, Mi Jin; Cho, Jeong Yeon; Min, Jee Yeon; Moon, Min Hwan; Kim, Jeong Ah [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

2005-06-15

To evaluate the sonographic findings of fetal congenital intracranial teratoma. From 1994 to 2002, of the 11 fetuses which had been diagnosed with fetal intracranial tumors after second level fetal ultrasonography, the six that were confirmed after autopsy as congenital intracranial teratomas were included in our study. The sonographic findings, including size, homogeneity, echogenicity compared with surrounding normal brain tissues, cystic components, and tumor related calcification, were retrospectively evaluated. The incidence of fetal congenital intracranial teratoma out of all fetal intracranial tumors was 54.5% (6 of 11 cases) during the 8-year period. The mean mass size was 7.4 cm (3.0-15.0 cm). Two thirds of (4/6) of the teratoma cases showed high echogenicity compared with normal brain tissues, and two thirds (4/6) showed heterogeneous echogenicity. Four teratoma cases (67%) showed cysts in the mass with a mean size of 1.9cm. One third (2/6) showed calcifications within the tumor. Out of the six cases, two had oropharyngeal teratoma with extension into the intracranial portion (so called epignathus) and showed homogenous mass without any cysts or calcifications. The typical sonographic appearance of intracranial teratoma was a heterogeneous, hyperechoic mass with cysts. In the epignathus cases, the sonographic appearances differed somewhat from the others. An understanding of the sonographic findings of fetal intracranial teratoma will help in the timely counseling of the parents and in obstetric decision making

[Incidence of phlebitis due to peripherally inserted venous catheters: impact of a catheter management protocol].

Science.gov (United States)

Ferrete-Morales, C; Vázquez-Pérez, M A; Sánchez-Berna, M; Gilabert-Cerro, I; Corzo-Delgado, J E; Pineda-Vergara, J A; Vergara-López, S; Gómez-Mateos, J

2010-01-01

To assess the impact on the incidence of PPIVC by implementing a catheter management protocol and to determine risk factors for PPIVC development in hospitalized patients. A total of 3978 episodes of venous catheterization were prospectively included from September 2002 to December 2007. A catheter management protocol was implemented during this period of time. The incidence and variables associated to the occurrence of PPIVC were determined. The incidence of PPIVC from 2002 to 2007 was 4.8%, 4.3%, 3.6%, 2.5%, 1.3% and 1.8% (phistory of phlebitis was the only factor independently associated to phlebitis due to peripherally inserted central venous catheters (AOR 3.24; CI at 95% CI= 1.05-9.98, p=0.04). A catheter management protocol decreases the incidence of PPIVC in hospitalized patients. The risk of PPIVC increases for peripherally inserted central venous catheters when the patients have a history of phlebitis and for peripheral venous catheters when amiodarone or cefotaxime are infused. Catheterization of peripheral veins performed during morning shifts is associated with a lower incidence of PPIVC when compared with night shift catheterizations.

Covalent Organic Framework Functionalized with 8-Hydroxyquinoline as a Dual-Mode Fluorescent and Colorimetric pH Sensor.

Science.gov (United States)

Chen, Long; He, Linwei; Ma, Fuyin; Liu, Wei; Wang, Yaxing; Silver, Mark A; Chen, Lanhua; Zhu, Lin; Gui, Daxiang; Diwu, Juan; Chai, Zhifang; Wang, Shuao

2018-05-09

Real-time and accurate detection of pH in aqueous solution is of great significance in chemical, environmental, and engineering-related fields. We report here the use of 8-hydroxyquinoline-functionalized covalent organic framework (COF-HQ) for dual-mode pH sensing. In the fluorescent mode, the emission intensity of COF-HQ weakened as the pH decreased, and also displayed a good linear relationship against pH in the range from 1 to 5. In addition, COF-HQ showed discernible color changes from yellow to black as the acidity increased and can be therefore used as a colorimetric pH sensor. All these changes are reversible and COF-HQ can be recycled for multiple detection runs owing to its high hydrolytical stability. It can be further assembled into a mixed matrix membrane for practical applications.

Spectral Imaging for Intracranial Stents and Stent Lumen.

Science.gov (United States)

Weng, Chi-Lun; Tseng, Ying-Chi; Chen, David Yen-Ting; Chen, Chi-Jen; Hsu, Hui-Ling

2016-01-01

Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen. In vitro, we scanned Enterprise stent phantom and a stent-cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20. In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P stent lumen (160.03 ±37.79; P stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis.

Radiofrequency catheter oblation in atrial flutter

International Nuclear Information System (INIS)

Yan Ji; Wang Heping; Xu Jian; Liu Fuyuan; Fan Xizhen; An Chunsheng; Han Xiaoping; Ding Xiaomei; Wang Jiasheng; Gu Tongyuan

2002-01-01

Objective: To evaluate the radiofrequency catheter ablation for type I atrial flutter through application of Holo catheter labelling with anatomic imaging localization to ablate the isthmus of IVCTA during complete double-way block. Methods: Eleven cases with type I atrial flutter undergone Holo catheter labelling technique and consecution with conduction time change of coronary venous sinus orifice with-right atrial lower lateral wall pace excitation, were performed with radiofrequency catheter ablation for the isthmus outcoming with complete double-way conduction block. Results: All together 11 cases with 4 of atrial flutter and 7 of sinus rhythm were undergone radiofrequency catheter ablation resulting with double-way conduction block of the isthmus accompanied by prolongation of right atrial conduction time 56.0 ± 2.3 ms and 53.0 ± 4.6 ms respectively. The right atrial excitation appeared to be in clockwise and counter-clockwise of single direction. No recurrence occurred during 3-34 months follow up with only one showing atrial fibrillation. Conclusions: The application of Holo catheter labelling technique with anatomic imaging localization to achieve the double-way conduction block by radiofrequency catheter ablation of TVC-TA isthmus, is a reliable method for treating atrial flutter

Non-contrast-enhanced 3D volumetric time-resolved MRA combining PCASL for intracranial vessels. President award proceedings

International Nuclear Information System (INIS)

Nakamura, Masanobu; Yoneyama, Masami; Tabuchi, Takashi; Tatsuno, Satoshi; Takemura, Atsushi; Obara, Makoto; Takahara, Taro

2013-01-01

Hemodynamic information is required for accurate diagnosis, effective treatment, and follow-up examination of numerous cerebrovascular diseases. A recently introduced technique for non-contrast 3-dimensional (3D) volumetric time-resolved magnetic resonance angiography (MRA)-contrast inherent inflow enhanced multi phase angiography (CINEMA)-provides useful qualitative information on the morphologic and dynamic filling of intracranial vessels and requires no catheter insertion or contrast agent. We propose combining CINEMA with pseudo-continuous arterial spin labeling (PCASL). We present a preliminary study of non-contrast time-resolved MRA with time-of-arrival map and discuss its clinical relevance. Studies in all volunteers and patients clearly depicted major intracranial vessels. In patients, CINEMA-PCASL demonstrated the nidus, feeding arteries, and right posterior cerebral artery, and subsequent draining into the superficial venous system was clearly observed with a temporal resolution of 200 ms. Time-of-arrival maps presented the different filling time of every segment vessel in a single colorful image. The expected pattern of delayed transit to more distal vessels is apparent as well as the earlier arrival in central portions of larger vessels. This preliminary study demonstrated the usefulness of the CINEMA-PCASL technique in evaluating the cerebral vasculature. Simultaneous acquisition of high quality temporal and spatial resolutions obviated the need for contrast agent. (author)

Non-contrast-enhanced 3D volumetric time-resolved MRA combining PCASL for intracranial vessels. President award proceedings

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Masanobu; Yoneyama, Masami; Tabuchi, Takashi; Tatsuno, Satoshi [Yaesu Clinic, Tokyo (Japan); Takemura, Atsushi; Obara, Makoto [Philips Electronics Japan, Tokyo (Japan); Takahara, Taro [Tokai Univ., Hiratsuka, Kanagawa (Japan)

2013-02-15

Hemodynamic information is required for accurate diagnosis, effective treatment, and follow-up examination of numerous cerebrovascular diseases. A recently introduced technique for non-contrast 3-dimensional (3D) volumetric time-resolved magnetic resonance angiography (MRA)-contrast inherent inflow enhanced multi phase angiography (CINEMA)-provides useful qualitative information on the morphologic and dynamic filling of intracranial vessels and requires no catheter insertion or contrast agent. We propose combining CINEMA with pseudo-continuous arterial spin labeling (PCASL). We present a preliminary study of non-contrast time-resolved MRA with time-of-arrival map and discuss its clinical relevance. Studies in all volunteers and patients clearly depicted major intracranial vessels. In patients, CINEMA-PCASL demonstrated the nidus, feeding arteries, and right posterior cerebral artery, and subsequent draining into the superficial venous system was clearly observed with a temporal resolution of 200 ms. Time-of-arrival maps presented the different filling time of every segment vessel in a single colorful image. The expected pattern of delayed transit to more distal vessels is apparent as well as the earlier arrival in central portions of larger vessels. This preliminary study demonstrated the usefulness of the CINEMA-PCASL technique in evaluating the cerebral vasculature. Simultaneous acquisition of high quality temporal and spatial resolutions obviated the need for contrast agent. (author)

10 KWe dual-mode space nuclear power system for military and scientific applications

International Nuclear Information System (INIS)

Malloy, J.; Westerman, K.; Rochow, R.; Scoles, S.

1992-01-01

This paper discusses a 10 KWe dual-mode space power system concept which has been identified and is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. This paper will focus on the nuclear power system design, including: the reactor with its UO 2 fuel in tungsten clad, 36 thermionic heat pipe modules (THPMs) which produce electricity within the reactor and remove waste heat, radiation shielding, waste heat radiators, and reactivity control systems. The use of non-vented fuel elements for short lifetime missions (under five years) will be described

Structural Design of Dual-Mode Ramjets and Associated System Issues (Conception structurale des statoreacteurs mixtes et defis systeme associes)

Science.gov (United States)

2010-09-01

Institute PAO Protection Against Oxidation RBCC Rocket Based Combined Cycle RSL Reusable Space Launchers SSTO Single Stage to Orbit TOW Take-Off Weight...Orbit) or Single Stage To Orbit ( SSTO ) vehicles, or other kind of hypersonic vehicles. For example, in the scope of the French PREPHA program, the...study of a generic SSTO vehicle led to conclusion that the best type of airbreathing engine could be the dual-mode ramjet (subsonic then supersonic

Intracranial MR angiography

International Nuclear Information System (INIS)

Davis, W.L.; Blatter, D.D.; Parker, D.L.; Robison, R.O.; Harnsberger, H.R.

1991-01-01

This paper compares the more traditional three-dimensional (3D) time-of-flight MR angiography with a novel new technique, MOTSA, in the evaluation of both normal and abnormal intracranial anatomy. The authors performed sequential, location-matched 3D TOF and MOTSA MR angiography in 10 subjects with normal and 25 with abnormal intracranial anatomy. Images were evaluated for visualization of specific vessels and depiction of pathologic anatomy. All images were subjected to an objective scoring system. Digital angiography was available in 15 of 25 abnormal cases. In the normal cases, large- and small-vessel visualization was improved. Significant improvement in visualization of venous anatomy was also observed. In the abnormal cases, pathologic anatomy was better visualized, providing important diagnostic information. Multiple overlapping thin-slab-acquisition MR angiography demonstrates vessel visualization that is increased over that of 3D TOF MR angiography in both normal and abnormal cases. Because of the decrease in saturation effects and phase dispersion, MOTSA is especially useful in the evaluation of complex intracranial vascular abnormalities

Dual-mode T_1 and T_2 magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

International Nuclear Information System (INIS)

Tegafaw, Tirusew; Xu, Wenlong; Ahmad, Md Wasi; Lee, Gang Ho; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong

2015-01-01

A new type of dual-mode T_1 and T_2 magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd"3"+ ("8S_7_/_2) plays an important role in T_1 MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy"3"+ ("6H_1_5_/_2) has the potential to be used in T_2 MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy_2O_3 nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd"3"+ and Dy"3"+ and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T_1 and T_2 MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (d_a_v_g = 1.0 nm) showed large r_1 and r_2 values (r_2/r_1 ≈ 6.6) and as a result clear dose-dependent contrast enhancements in R_1 and R_2 map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T_1 and T_2 MR images. (paper)

The risk of intravenous thrombolysis-induced intracranial hemorrhage in Taiwanese patients with unruptured intracranial aneurysm.

Directory of Open Access Journals (Sweden)

Wei Ting Chiu

Full Text Available The presence of an intracranial aneurysm is contraindicated to recombinant tissue plasminogen activator (r-tPA treatment for acute ischemic stroke. However, it is difficult to exclude asymptomatic intracranial aneurysms by using conventional, noncontrast head computed tomography (CT, which is the only neuroimaging suggested before r-tPA. Recent case reports and series have shown that administering r-tPA to patients with a pre-existing aneurysm does not increase the bleeding risk. However, Asians are known to have a relatively higher bleeding risk, and little evidence is available regarding the risk of using r-tPA on Asian patients with intracranial aneurysms.Medical records from the Shuang Ho hospital stroke registration between July 2010 and December 2014 were retrospectively reviewed, and 144 patients received r-tPA. Unruptured intracranial aneurysms were detected using CT, or magnetic resonance or conventional angiography after r-tPA. The primary and secondary outcomes were the difference in overall intracranial hemorrhage (ICH and symptomatic ICH after r-tPA. The differences were analyzed using Fisher's exact or Mann-Whitney U tests, and p < 0.05 was defined as the statistical significance.A total of 144 patients were reviewed, and incidental unruptured intracranial aneurysms were found in 11 of them (7.6%. No significant difference was observed in baseline demographic data between the aneurysm and nonaneurysm groups. Among patients with an unruptured aneurysm, two had giant aneurysms (7.7 and 7.4 mm, respectively. The bleeding risk was not significant different between aneurysm group (2 out of 11, 18% with nonaneurysm group (7 out of 133, 5.3% (p = 0.14. None of the patients with an unruptured aneurysm had symptomatic ICH, whereas one patient without an aneurysm exhibited symptomatic ICH.The presence of an unruptured intracranial aneurysm did not significantly increase the risk of overall and symptomatic ICH in Taiwanese patients after they

Microgeneration of electricity with producer gas in dual fuel mode operation Microgeração de eletricidade com gás de gaseificação num motor gerador dual

Directory of Open Access Journals (Sweden)

Marcelo J. Silva

2011-10-01

Full Text Available Among the alternatives to meet the increasing of world demand for energy, the use of biomass as energy source is one of the most promising as it contributes to reducing emissions of carbon dioxide in the atmosphere. Gasification is a technological process of biomass energy production of a gaseous biofuel. The fuel gas has a low calorific value that can be used in Diesel engine in dual mode for power generation in isolated communities. This study aimed to evaluate the reduction in the consumption of oil Diesel an engine generator, using gas from gasification of wood. The engine generator brand used was a BRANCO, with direct injection power of 7.36 kW (10 HP coupled to an electric generator 5.5 kW. Diesel oil mixed with intake air was injected, as the oil was injected via an injector of the engine (dual mode. The fuel gas was produced in a downdraft gasifier. The engine generator was put on load system from 0.5 kW to 3.5 kW through a set of electrical resistances. Diesel oil consumption was measured with a precision scale. It was concluded that the engine converted to dual mode when using the gas for the gasification of wood decreased Diesel consumption by up to 57%.Dentre as alternativas à crescente demanda energética mundial, o uso da biomassa como fonte de energia é uma das formas mais promissoras, pois contribui para a redução das emissões de dióxido de carbono na atmosfera. A gaseificação é uma tecnologia de transformação energética da biomassa num biocombustível gasoso. O gás de gaseificação é um combustível de baixo poder calorífico que pode ser utilizado em motor ciclo Diesel no modo dual para geração de energia elétrica em comunidades isoladas. Este trabalho teve por objetivo avaliar a redução no consumo de Diesel num motor gerador, com a utilização de gás da gaseificação da madeira. O motor avaliado foi da marca BRANCO, com injeção direta e potência de 7,36 kW (10 cv acoplado a um gerador elétrico de 5

Intracranial hypertension prediction using extremely randomized decision trees.

Science.gov (United States)

Scalzo, Fabien; Hamilton, Robert; Asgari, Shadnaz; Kim, Sunghan; Hu, Xiao

2012-10-01

Intracranial pressure (ICP) elevation (intracranial hypertension, IH) in neurocritical care is typically treated in a reactive fashion; it is only delivered after bedside clinicians notice prolonged ICP elevation. A proactive solution is desirable to improve the treatment of intracranial hypertension. Several studies have shown that the waveform morphology of the intracranial pressure pulse holds predictors about future intracranial hypertension and could therefore be used to alert the bedside clinician of a likely occurrence of the elevation in the immediate future. In this paper, a computational framework is proposed to predict prolonged intracranial hypertension based on morphological waveform features computed from the ICP. A key contribution of this work is to exploit an ensemble classifier method based on extremely randomized decision trees (Extra-Trees). Experiments on a representative set of 30 patients admitted for various intracranial pressure related conditions demonstrate the effectiveness of the predicting framework on ICP pulses acquired under clinical conditions and the superior results of the proposed approach in comparison to linear and AdaBoost classifiers. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Intracranial metastases: spectrum of MR imaging findings

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun Kyoung; Lee, Eun Ja; Lee, Yong Seok [Department of Radiology, Dongguk University Ilsan Hospital, Goyang-shi (Korea, Republic of)], E-mail: ejl1048@hanmail.net; Kim, Mi Sung; Park, No Hyuck [Department of Radiology, Kwandong University, College of Medicine, Myongji Hospital, Goyang-shi (Korea, Republic of); Park, Hee-Jin [Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); II, Sung Park [Department of Diagnostic Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

2012-12-15

Intracranial metastatic lesions arise through a number of routes. Therefore, they can involve any part of the central nervous system and their imaging appearances vary. Magnetic resonance imaging (MRI) plays a key role in lesion detection, lesion delineation, and differentiation of metastases from other intracranial disease processes. This article is a reasoned pictorial review illustrating the many faces of intracranial metastatic lesions based on the location - intra-axial metastases, calvarial metastases, dural metastases, leptomeningeal metastases, secondary invasion of the meninges by metastatic disease involving the calvarium and skull base, direct or perineural intracranial extension of head and neck neoplasm, and other unusual manifestations of intracranial metastases. We also review the role of advanced MRI to distinguish metastases from high-grade gliomas, tumor-mimicking lesions such as brain abscesses, and delayed post-radiation changes in radiosurgically treated patients.

An assessment of the dual-mode reactivity controlled compression ignition/conventional diesel combustion capabilities in a EURO VI medium-duty diesel engine fueled with an intermediate ethanol-gasoline blend and biodiesel

International Nuclear Information System (INIS)

Benajes, Jesús; García, Antonio; Monsalve-Serrano, Javier; Balloul, Iyad; Pradel, Gérard

2016-01-01

Highlights: • Reactivity controlled compression ignition regime utilized from 25% to 35% load. • Dual-mode reduces the regeneration periods of the diesel particulate filter. • The use of near-term available biofuels allows good performance and emissions. • Dual-mode leads to 2% greater efficiency than diesel combustion at high engine speeds. - Abstract: This work investigates the capabilities of the dual-mode reactivity controlled compression ignition/conventional diesel combustion engine operation to cover the full operating range of a EURO VI medium-duty diesel engine with compression ratio of 17.5:1. This concept is based on covering all the engine map switching between the reactivity controlled compression ignition and the conventional diesel combustion operating modes. Specifically, the benefits of reactivity controlled compression ignition combustion are exploited whenever possible according to certain restrictions, while the conventional diesel combustion operation is used to cover the zones of the engine map in which the reactivity controlled compression ignition operation is limited. The experiments were conducted using a single-cylinder research diesel engine derived from the multi-cylinder production engine. In addition, considering the mandatory presence of biofuels in the future context of road transport and the ability of ethanol to be blended with gasoline, the low reactivity fuel used in the study is a blend of 20% ethanol by volume with 80% of 95 octane number gasoline. Moreover, a diesel containing 7% of biodiesel has been used as high reactivity fuel. Firstly, a reactivity controlled compression ignition mapping is performed to check the operational limits of the concept in this engine platform. Later, based on the results, the potential of the dual-mode concept is discussed. Results suggest that, under the constraints imposed, reactivity controlled compression ignition combustion can be utilized between 25% and 35% load. In this region

Novel control modes to improve the performance of rectilinear ion trap mass spectrometer with dual pressure chambers

Science.gov (United States)

Huo, Xinming; Tang, Fei; Zhang, Xiaohua; Chen, Jin; Zhang, Yan; Guo, Cheng'an; Wang, Xiaohao

2016-10-01

The rectilinear ion trap (RIT) has gradually become one of the preferred mass analyzers for portable mass spectrometers because of its simple configuration. In order to enhance the performance, including sensitivity, quantitation capability, throughput, and resolution, a novel RIT mass spectrometer with dual pressure chambers was designed and characterized. The studied system constituted a quadrupole linear ion trap (QLIT) in the first chamber and a RIT in the second chamber. Two control modes are hereby proposed: Storage Quadrupole Linear Ion Trap-Rectilinear Ion Trap (SQLIT-RIT) mode, in which the QLIT was used at high pressure for ion storage and isolation, and the RIT was used for analysis; and Analysis Quadrupole Linear Ion Trap-Rectilinear Ion Trap (AQLIT-RIT) mode, in which the QLIT was used for ion storage and cooling. Subsequently, synchronous scanning and analysis were carried out by QLIT and RIT. In SQLIT-RIT mode, signal intensity was improved by a factor of 30; the limit of quantitation was reduced more than tenfold to 50 ng mL-1, and an optimal duty cycle of 96.4% was achieved. In AQLIT-RIT mode, the number of ions coexisting in the RIT was reduced, which weakened the space-charge effect and reduced the mass shift. Furthermore, the mass resolution was enhanced by a factor of 3. The results indicate that the novel control modes achieve satisfactory performance without adding any system complexity, which provides a viable pathway to guarantee good analytical performance in miniaturization of the mass spectrometer.

The Role of Intraoperative Cerebral Angiography in Transorbital Intracranial Penetrating Trauma: A Case Report and Literature Review.

Science.gov (United States)

Riley, Jonathan P; Boucher, Andrew B; Kim, Denise S; Barrow, Daniel L; Reynolds, Matthew R

2017-01-01

Transorbital intracranial penetrating trauma with a retained intracranial foreign body is a rare event lacking a widely accepted diagnostic and therapeutic algorithm. Intraoperative catheter angiography (IOA) has been advocated by some authorities to rule out cerebrovascular injury before and/or after removal of the object, but no standard of care currently exists. A 19-year-old man was involved in a construction site accident whereby a framing nail penetrated the left globe, traversed the lateral bony orbit, and terminated in the midtemporal lobe. No hematoma or injury to the middle cerebral arteries (MCAs) was apparent on noncontrast head computed tomography (CT) or CT angiography, respectively. The foreign body was removed in the operating room under direct visualization after a frontotemporal craniotomy without incident. No significant venous or arterial bleeding was encountered. All visualized MCA branches appeared intact. Indocyanine green videoangiography performed immediately after object removal showed adequate filling of the MCA branches. Given these uneventful clinical and radiographic findings, IOA was not performed. Postoperative head CT and CT angiography showed no obvious neurovascular injury. On postoperative day 2, the patient was noted to have an expressive aphasia. Cerebral angiography showed absent antegrade filling of the angular artery with some retrograde perfusion. Magnetic resonance imaging confirmed an ischemic infarction in the midtemporal lobe. The patient's expressive aphasia improved to near baseline during his hospitalization and he made an excellent clinical recovery. In transorbital intracranial penetrating trauma with a retained intracranial object, we advocate microsurgical removal of the object under direct visualization followed immediately by IOA. IOA should be strongly considered even in the setting of minimal intraoperative bleeding and normal findings on videoangiography (a course of action that was not followed in the

Dual-Mode Scramjet Flameholding Operability Measurements

Science.gov (United States)

Donohue, James M.

2012-01-01

Flameholding measurements were made in two different direct connect combustor facilities that were designed to simulate a cavity flameholder in the flowfield of a hydrocarbon fueled dual-mode scramjet combustor. The presence of a shocktrain upstream of the flameholder has a significant impact on the inlet flow to the combustor and on the flameholding limits. A throttle was installed in the downstream end of the test rigs to provide the needed back-pressurization and decouple the operation of the flameholder from the backpressure formed by heat release and thermal choking, as in a flight engine. Measurements were made primarily with ethylene fuel but a limited number of tests were also performed with heated gaseous JP-7 fuel injection. The flameholding limits were measured by ramping inlet air temperature down until blowout was observed. The tests performed in the United Technologies Research Center (UTRC) facility used a hydrogen fueled vitiated air heater, Mach 2.2 and 3.3 inlet nozzles, a scramjet combustor rig with a 1.666 by 6 inch inlet and a 0.65 inch deep cavity. Mean blowout temperature measured at the baseline condition with ethylene fuel, the Mach 2.2 inlet and a cavity pressure of 21 psia was 1502 oR. Flameholding sensitivity to a variety of parameters was assessed. Blowout temperature was found to be most sensitive to fuel injection location and fuel flowrates and surprisingly insensitive to operating pressure (by varying both back-pressurization and inlet flowrate) and inlet Mach number. Video imaging through both the bottom and side wall windows was collected simultaneously and showed that the flame structure was quite unsteady with significant lateral movements as well as movement upstream of the flameholder. Experiments in the University of Virginia (UVa) test facility used a Mach 2 inlet nozzle with a 1 inch by 1.5 inch exit cross section, an aspect ratio of 1.5 versus 3.6 in the UTRC facility. The UVa facility tests were designed to measure the

Self-starting and overclocking a harmonically mode-locking WRC-FPLD with a dual-loop feedback controller for 10 Gb s−1 pulse-data transmission

International Nuclear Information System (INIS)

Lin, Chun-Ju; Chi, Yu-Chieh; Lin, Gong-Ru

2013-01-01

The self-starting and overclocking of a harmonically mode-locked weak-resonant-cavity Fabry–Perot laser diode (WRC-FPLD) with a dual-loop coupled optoelectronic oscillator (COEO) based feedback controller is demonstrated to perform a clock-free pulsed data transmission at 10 Gb s −1 . The WRC-FPLD is considered as the preferred candidate for harmonic mode-locking due to its highly asymmetric cavity architecture, whereby the spontaneous noise can be significantly suppressed without inducing large intra-cavity loss. With the dual-loop COEO configuration, the WRC-FPLD can be boosted to four times of its original modulation bandwidth such that the pulsed carrier quality can be refined. The structure-optimizing principle with the closed-loop model is corroborated by the effective spurious-noise-suppression. The lowest phase noises as low as −100 dBc Hz −1 at 10 kHz with corresponding RMS timing jitter of 0.67 ps are measured. This is achieved by individually inserting 100 and 120 m long single mode fiber segments into two decoupled arms, the dual-loop COEO before the optical receiver pair. The BER performance reaches a minimum with the optimized SMF segment lengths. However, the spurious peaks arise to degrade the BER performance as the phase noise and jitter are inevitably enlarged when inserting longer SMF segments. After modulating the optimized output pulse train with the pseudo-random-bit-sequence data triggered by the same COEO clock, the SNR can achieve 10.9 dB and the receiving sensitivity is −19.2 dBm. (letter)

In vitro analysis of balloon cuffing phenomenon: inherent biophysical properties of catheter material or mechanics of catheter balloon deflation?

Science.gov (United States)

Chung, Eric; So, Karina

2012-06-01

To investigates the different methods of balloon deflation, types of urinary catheters and exposure to urine media in catheter balloon cuffing. Bardex®, Bard-Lubri-Sil®, Argyle®, Releen® and Biocath® were tested in sterile and E.Coli inoculated urine at 0, 14 and 28 days. Catheter deflation was performed with active deflation; passive deflation; passive auto-deflation; and excision of the balloon inflow channel. Balloon cuffing was assessed objectively by running the deflated balloon over a plate of agar and subjectively by 3 independent observers. Bardex®, Argyle® and Biocath® showed greater degree of catheter balloon cuffing (p deflation was the worst method (p 0.05). Linear regression model analysis confirmed time as the most significant factor. The duration of catheters exposure, different deflation methods and types of catheters tested contributed significantly to catheter balloon cuffing (p < 0.01).

Intracranial Monitoring after Severe Traumatic Brain Injury

OpenAIRE

Donnelly, Joseph

2018-01-01

Intracranial monitoring after severe traumatic brain injury offers the possibility for early detection and amelioration of physiological insults. In this thesis, I explore cerebral insults due raised intracranial pressure, decreased cerebral perfusion pressure and impaired cerebral pressure reactivity after traumatic brain injury. In chapter 2, the importance of intracranial pressure, cerebral perfusion pressure and pressure reactivity in regulating the cerebral circulation is elucidated ...

Optimal control of mode transition for four-wheel-drive hybrid electric vehicle with dry dual-clutch transmission

Science.gov (United States)

Zhao, Zhiguo; Lei, Dan; Chen, Jiayi; Li, Hangyu

2018-05-01

When the four-wheel-drive hybrid electric vehicle (HEV) equipped with a dry dual clutch transmission (DCT) is in the mode transition process from pure electrical rear wheel drive to front wheel drive with engine or hybrid drive, the problem of vehicle longitudinal jerk is prominent. A mode transition robust control algorithm which resists external disturbance and model parameter fluctuation has been developed, by taking full advantage of fast and accurate torque (or speed) response of three electrical power sources and getting the clutch of DCT fully involved in the mode transition process. Firstly, models of key components of driveline system have been established, and the model of five-degrees-of-freedom vehicle longitudinal dynamics has been built by using a Uni-Tire model. Next, a multistage optimal control method has been produced to realize the decision of engine torque and clutch-transmitted torque. The sliding-mode control strategy for measurable disturbance has been proposed at the stage of engine speed dragged up. Meanwhile, the double tracking control architecture that integrates the model calculating feedforward control with H∞ robust feedback control has been presented at the stage of speed synchronization. Finally, the results from Matlab/Simulink software and hardware-in-the-loop test both demonstrate that the proposed control strategy for mode transition can not only coordinate the torque among different power sources and clutch while minimizing vehicle longitudinal jerk, but also provide strong robustness to model uncertainties and external disturbance.

Sex differences in intracranial arterial bifurcations

DEFF Research Database (Denmark)

Lindekleiv, Haakon M; Valen-Sendstad, Kristian; Morgan, Michael K

2010-01-01

. The female preponderance is usually explained by systemic factors (hormonal influences and intrinsic wall weakness); however, the uneven sex distribution of intracranial aneurysms suggests a possible physiologic factor-a local sex difference in the intracranial arteries....

Prevention of catheter-related blood stream infection.

Science.gov (United States)

Byrnes, Matthew C; Coopersmith, Craig M

2007-08-01

Catheter-related blood stream infections are a morbid complication of central venous catheters. This review will highlight a comprehensive approach demonstrated to prevent catheter-related blood stream infections. Elements of prevention important to inserting a central venous catheter include proper hand hygiene, use of full barrier precautions, appropriate skin preparation with 2% chlorhexidine, and using the subclavian vein as the preferred anatomic site. Rigorous attention needs to be given to dressing care, and there should be daily assessment of the need for central venous catheters, with prompt removal as soon as is practicable. Healthcare workers should be educated routinely on methods to prevent catheter-related blood stream infections. If rates remain higher than benchmark levels despite proper bedside practice, antiseptic or antibiotic-impregnated catheters can also prevent infections effectively. A recent program utilizing these practices in 103 ICUs in Michigan resulted in a 66% decrease in infection rates. There is increasing recognition that a comprehensive strategy to prevent catheter-related blood stream infections can prevent most infections, if not all. This suggests that thousands of infections can potentially be averted if the simple practices outlined herein are followed.

Research on Control Strategies of an Open-End Winding Permanent Magnet Synchronous Driving Motor (OW-PMSM-Equipped Dual Inverter with a Switchable Winding Mode for Electric Vehicles

Directory of Open Access Journals (Sweden)

Liang Chu

2017-05-01

Full Text Available An open-end winding permanent magnet synchronous motor (PMSM has a larger range of speed regulation than normal PMSM with the same DC voltage, and the control method is more flexible. It can also manage energy distribution between two power sources without a DC/DC converter. This paper aims at an electric vehicle equipped with OW-PMSM drive system with dual power sources and dual inverters; based on analyzing the external characteristics of each winding mode, we propose a winding mode switching strategy whose torque saturation judgmental algorithm, which is insensitive to motor’s parameters, could automatically realize upswitching of the winding mode. The proposed multi-level current hysteresis modulation algorithm could set the major power source and switch it at any time in independent mode, which accomplishes energy distribution between two power sources; its two control methods, low switching frequency method and high power difference method, could achieve different energy distribution effects. Simulation results confirm the validity and effectiveness of the winding mode switching strategy and current modulation method. They also show that an electric vehicle under the proposed control methods has better efficiency than one equipped with a traditional OW-PMSM drive system under traditional control.

Inter-comb synchronization by mode-to-mode locking

Science.gov (United States)

Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

2016-08-01

Two combs of fiber femtosecond lasers are synchronized through the optical frequency reference created by injection-locking of a diode laser to a single comb mode. Maintaining a mHz-level narrow linewidth, the optical frequency reference permits two combs to be stabilized by mode-to-mode locking with a relative stability of 1.52  ×  10-16 at 10 s with a frequency slip of 2.46 mHz. This inter-comb synchronization can be utilized for applications such as dual-comb spectroscopy or ultra-short pulse synthesis without extra narrow-linewidth lasers.

Development of Real-Time Dual-Display Handheld and Bench-Top Hybrid-Mode SD-OCTs

Directory of Open Access Journals (Sweden)

Nam Hyun Cho

2014-01-01

Full Text Available Development of a dual-display handheld optical coherence tomography (OCT system for retina and optic-nerve-head diagnosis beyond the volunteer motion constraints is reported. The developed system is portable and easily movable, containing the compact portable OCT system that includes the handheld probe and computer. Eye posterior chambers were diagnosed using the handheld probe, and the probe could be fixed to the bench-top cradle depending on the volunteers’ physical condition. The images obtained using this handheld probe were displayed in real time on the computer monitor and on a small secondary built-in monitor; the displayed images were saved using the handheld probe’s built-in button. Large-scale signal-processing procedures such as k-domain linearization, fast Fourier transform (FFT, and log-scaling signal processing can be rapidly applied using graphics-processing-unit (GPU accelerated processing rather than central-processing-unit (CPU processing. The Labview-based system resolution is 1,024 × 512 pixels, and the frame rate is 56 frames/s, useful for real-time display. The 3D images of the posterior chambers including the retina, optic-nerve head, blood vessels, and optic nerve were composed using real-time displayed images with 500 × 500 × 500 pixel resolution. A handheld and bench-top hybrid mode with a dual-display handheld OCT was developed to overcome the drawbacks of the conventional method.

Multiple intracranial hydatid cysts: MR findings

International Nuclear Information System (INIS)

Pumar, J.; Alvarez, M.; Leira, R.; Prieto, J.M.; Arrojo, L.; Pereira, J.; Vidal, J.

1992-01-01

Multiple intracranial hydatid cysts are uncommon and usually localized in the supratentorial compartment. We report a case studied by CT and MR of multiple intracranial hydatid cysts scattered in various anatomic sites: supratentorial, infratentorial and also intraventricular. (orig.)

Multipurpose, dual-mode imaging in the 3-5 μm range (MWIR) for artwork diagnostics: A systematic approach

Science.gov (United States)

Daffara, Claudia; Parisotto, Simone; Ambrosini, Dario

2018-05-01

We present a multi-purpose, dual-mode imaging method in the Mid-Wavelength Infrared (MWIR) range (from 3 μm to 5 μm) for a more efficient nondestructive analysis of artworks. Using a setup based on a MWIR thermal camera and multiple radiation sources, two radiometric image datasets are acquired in different acquisition modalities, the image in quasi-reflectance mode (TQR) and the thermal sequence in emission mode. Here, the advantages are: the complementarity of the information; the use of the quasi-reflectance map for calculating the emissivity map; the use of TQR map for a referentiation to the visible of the thermographic images. The concept of the method is presented, the practical feasibility is demonstrated through a custom imaging setup, the potentiality for the nondestructive analysis is shown on a notable application to cultural heritage. The method has been used as experimental tool in support of the restoration of the mural painting "Monocromo" by Leonardo da Vinci. Feedback from the operators and a comparison with some conventional diagnostic techniques is also given to underline the novelty and potentiality of the method.

Adaptive sampling dual terahertz comb spectroscopy using dual free-running femtosecond lasers.

Science.gov (United States)

Yasui, Takeshi; Ichikawa, Ryuji; Hsieh, Yi-Da; Hayashi, Kenta; Cahyadi, Harsono; Hindle, Francis; Sakaguchi, Yoshiyuki; Iwata, Tetsuo; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Minoshima, Kaoru; Inaba, Hajime

2015-06-02

Terahertz (THz) dual comb spectroscopy (DCS) is a promising method for high-accuracy, high-resolution, broadband THz spectroscopy because the mode-resolved THz comb spectrum includes both broadband THz radiation and narrow-line CW-THz radiation characteristics. In addition, all frequency modes of a THz comb can be phase-locked to a microwave frequency standard, providing excellent traceability. However, the need for stabilization of dual femtosecond lasers has often hindered its wide use. To overcome this limitation, here we have demonstrated adaptive-sampling THz-DCS, allowing the use of free-running femtosecond lasers. To correct the fluctuation of the time and frequency scales caused by the laser timing jitter, an adaptive sampling clock is generated by dual THz-comb-referenced spectrum analysers and is used for a timing clock signal in a data acquisition board. The results not only indicated the successful implementation of THz-DCS with free-running lasers but also showed that this configuration outperforms standard THz-DCS with stabilized lasers due to the slight jitter remained in the stabilized lasers.

New Edge Coherent Mode Providing Continuous Transport in Long Pulse H-mode Plasmas

DEFF Research Database (Denmark)

Wang, H.Q.; Xu, G.S.; Wan, B.N.

2014-01-01

An electrostatic coherent mode near the electron diamagnetic frequency (20–90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Super-conducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond-coated reciproc...

Intracranial stenosis in cognitive impairment and dementia.

Science.gov (United States)

Hilal, Saima; Xu, Xin; Ikram, M Kamran; Vrooman, Henri; Venketasubramanian, Narayanaswamy; Chen, Christopher

2017-06-01

Intracranial stenosis is a common vascular lesion observed in Asian and other non-Caucasian stroke populations. However, its role in cognitive impairment and dementia has been under-studied. We, therefore, examined the association of intracranial stenosis with cognitive impairment, dementia and their subtypes in a memory clinic case-control study, where all subjects underwent detailed neuropsychological assessment and 3 T neuroimaging including three-dimensional time-of-flight magnetic resonance angiography. Intracranial stenosis was defined as ≥50% narrowing in any of the intracranial arteries. A total of 424 subjects were recruited of whom 97 were classified as no cognitive impairment, 107 as cognitive impairment no dementia, 70 vascular cognitive impairment no dementia, 121 Alzheimer's Disease, and 30 vascular dementia. Intracranial stenosis was associated with dementia (age/gender/education - adjusted odds ratios (OR): 4.73, 95% confidence interval (CI): 1.93-11.60) and vascular cognitive impairment no dementia (OR: 3.98, 95% CI: 1.59-9.93). These associations were independent of cardiovascular risk factors and MRI markers. However, the association with Alzheimer's Disease and vascular dementia became attenuated in the presence of white matter hyperintensities. Intracranial stenosis is associated with vascular cognitive impairment no dementia independent of MRI markers. In Alzheimer's Disease and vascular dementia, this association is mediated by cerebrovascular disease. Future studies focusing on perfusion and functional markers are needed to determine the pathophysiological mechanism(s) linking intracranial stenosis and cognition so as to identify treatment strategies.

Usefulness of gram staining of blood collected from total parenteral nutrition catheter for rapid diagnosis of catheter-related sepsis.

Science.gov (United States)

Moonens, F; el Alami, S; Van Gossum, A; Struelens, M J; Serruys, E

1994-01-01

The accuracy of Gram staining of blood drawn from catheters used to administer total parenteral nutrition was compared with paired quantitative blood cultures for the diagnosis of catheter-related sepsis. Gram staining was positive in 11 of 18 episodes of catheter-related sepsis documented by quantitative culture (sensitivity, 61%) but in none of the 5 episodes of fever unrelated to catheter infection. Thus, this procedure enabled the rapid presumptive diagnosis and guidance of antimicrobial therapy for total parenteral nutrition catheter sepsis, with a positive predictive value of 100% and a negative predictive value of 42%. PMID:7521359

Traumatic and alternating delayed intracranial hematomas

Energy Technology Data Exchange (ETDEWEB)

Lesoin, F.; Redford, H.; Jomin, M.; Viaud, C.; Pruvo, J.

1984-11-01

Repeat computed tomography has enabled us to confirm the concept of delayed hematomas. With this in mind we report two cases of alternating, post-traumatic intracranial hematomas; confirming also the role of tamponade after surgical removal of an intracranial hematoma.

Traumatic and alternating delayed intracranial hematomas

International Nuclear Information System (INIS)

Lesoin, F.; Redford, H.; Jomin, M.; Viaud, C.; Pruvo, J.

1984-01-01

Repeat computed tomography has enabled us to confirm the concept of delayed hematomas. With this in mind we report two cases of alternating, post-traumatic intracranial hematomas; confirming also the role of tamponade after surgical removal of an intracranial hematoma. (orig.)

Temporal resolution measurement of 128-slice dual source and 320-row area detector computed tomography scanners in helical acquisition mode using the impulse method.

Science.gov (United States)

Hara, Takanori; Urikura, Atsushi; Ichikawa, Katsuhiro; Hoshino, Takashi; Nishimaru, Eiji; Niwa, Shinji

2016-04-01

To analyse the temporal resolution (TR) of modern computed tomography (CT) scanners using the impulse method, and assess the actual maximum TR at respective helical acquisition modes. To assess the actual TR of helical acquisition modes of a 128-slice dual source CT (DSCT) scanner and a 320-row area detector CT (ADCT) scanner, we assessed the TRs of various acquisition combinations of a pitch factor (P) and gantry rotation time (R). The TR of the helical acquisition modes for the 128-slice DSCT scanner continuously improved with a shorter gantry rotation time and greater pitch factor. However, for the 320-row ADCT scanner, the TR with a pitch factor of pitch factor of >1.0, it was approximately one half of the gantry rotation time. The maximum TR values of single- and dual-source helical acquisition modes for the 128-slice DSCT scanner were 0.138 (R/P=0.285/1.5) and 0.074s (R/P=0.285/3.2), and the maximum TR values of the 64×0.5- and 160×0.5-mm detector configurations of the helical acquisition modes for the 320-row ADCT scanner were 0.120 (R/P=0.275/1.375) and 0.195s (R/P=0.3/0.6), respectively. Because the TR of a CT scanner is not accurately depicted in the specifications of the individual scanner, appropriate acquisition conditions should be determined based on the actual TR measurement. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

[Peripheral intravenous catheter-related phlebitis].

Science.gov (United States)

van der Sar-van der Brugge, Simone; Posthuma, E F M Ward

2011-01-01

Phlebitis is a very common complication of the use of intravenous catheters. Two patients with an i.v. catheter complicated by thrombophlebitis are described. Patient A was immunocompromised due to chronic lymphatic leukaemia and developed septic thrombophlebitis with positive blood cultures for S. Aureus. Patient B was being treated with flucloxacillin because of an S. Aureus infection and developed chemical phlebitis. Septic phlebitis is rare, but potentially serious. Chemical or mechanical types of thrombophlebitis are usually less severe, but happen very frequently. Risk factors include: female sex, previous episode of phlebitis, insertion at (ventral) forearm, emergency placement and administration of antibiotics. Until recently, routine replacement of peripheral intravenous catheters after 72-96 h was recommended, but randomised controlled trials have not shown any benefit of this routine. A recent Cochrane Review recommends replacement of peripheral intravenous catheters when clinically indicated only.

Dual Mode Fluorophore-Doped Nickel Nitrilotriacetic Acid-Modified Silica Nanoparticles Combine Histidine-Tagged Protein Purification with Site-Specific Fluorophore Labeling

OpenAIRE

Kim, Sung Hoon; Jeyakumar, M.; Katzenellenbogen, John A.

2007-01-01

We present the first example of a fluorophore-doped nickel chelate surface- modified silica nanoparticle that functions in a dual mode, combining histidine-tagged protein purification with site-specific fluorophore labeling. Tetramethylrhodamine (TMR)-doped silica nanoparticles, estimated to contain 700–900 TMRs per ca. 23-nm particle, were surface modified with nitrilotriacetic acid (NTA), producing TMR-SiO2-NTA-Ni+2. Silica-embedded TMR retains very high quantum yield, is resistant to quenc...

Simulation de Ia propagation de fissures dans les solides elastiques en modes mixtes par Ia methode des equations integrales duales

OpenAIRE

Kebir , Hocine; Roelandt , Jean Marc; Gaudin , Jocelyn

2000-01-01

International audience; The present paper is concerned with the effective numerical implementation of the two dimensional Dual Boundary element method to analyse the mixed-mode crack growth All the boundaries are discretized with discontinuous quadratic boundary elements and the crack-tip is modeled by singular elements that exactly represent the strain field singularity $1/\\sqrt{r}$. The Stress lntensity Factors can be computed very accurately from the crack opening dis placement at collocat...

Value of Micronester coils in port-catheter implantation for continuous hepatic arterial infusion chemotherapy with fixed catheter tip method

International Nuclear Information System (INIS)

Yamagami, Takuji; Kato, Takeharu; Hirota, Tatsuya; Yoshimatsu, Rika; Matsumoto, Tomohiro; Nishimura, Tsunehiko; White, Robert I.

2008-01-01

To retrospectively evaluate the use of Micronester coils in port-catheter implantation with the fixed catheter tip method in comparison with other previously used coils. The cohort of this study was 143 consecutive patients with unresectable advanced liver cancer for whom a port-catheter system was percutaneously implanted. In the most recent 32 patients, Micronester coils were used for catheter tip fixation. Details of embolic agents for fixation, persistent blood flow beyond the distal end of the indwelling catheter, and complications were compared between cases without and with Micronester coils. In all, percutaneous port-catheter placement was successful. Mean number of coils used for fixation was 4.2 without Micronester coils vs. 2.5 with Micronester coils. N-butyl cyanoacrylate (NBCA)-Lipiodol was additionally used for catheter tip fixation in 85.6% of 111 procedures without Micronester coils and in 50% of 32 using Micronester coils. The gastroduodenal artery beyond the distal end was not detected at the final examination after any procedure. Catheter dislocation occurred in five and hepatic arterial obstruction or severe stenosis in eight. The number of coils used and necessity of NBCA-Lipiodol could be decreased with usage of Micronester coils without decreasing fixation ability compared to other coils. (orig.)

Electron heating mode transition induced by mixing radio frequency and ultrahigh frequency dual frequency powers in capacitive discharges

International Nuclear Information System (INIS)

Sahu, B. B.; Han, Jeon G.

2016-01-01

Electron heating mode transitions induced by mixing the low- and high-frequency power in dual-frequency nitrogen discharges at 400 mTorr pressure are presented. As the low-frequency (13.56 MHz) power decreases and high-frequency (320 MHz) power increases for the fixed power of 200 W, there is a transition of electron energy distribution function (EEDF) from Druyvesteyn to bi-Maxwellian type characterized by a distinguished warm electron population. It is shown that this EEDF evolution is attributed to the transition from collisional to collisionless stochastic heating of the low-energy electrons.

[Aortic elastic properties and its clinical significance in intracranial aneurysms].

Science.gov (United States)

Pu, Zhao-xia; You, Xiang-dong; Weng, Wen-chao; Wang, Jian-an; Shi, Jian

2011-09-01

To investigate the aortic elastic properties and its clinical significance in intracranial aneurysms (IAs). One hundred and seven IAs patients (57 with hypertension) and 108 healthy subjects were recruited. The internal aortic diameters in systole and diastole were measured by the M-mode echocardiography, the aortic elasticity indexes were calculated and compared. The aortic distensibility (DIS) was lower and the aortic stiffness index (SI) was higher in IAs patients than those in controls (both P IAs patients with hypertension (IAs-HP) than those in IAs with no hypertension (P IAs patients and hypertension is closely related to the severity of aortic elasticity.

Microoptomechanical sensor for intracranial pressure monitoring

International Nuclear Information System (INIS)

Andreeva, A V; Luchinin, V V; Lutetskiy, N A; Sergushichev, A N

2014-01-01

The main idea of this research is the development of microoptomechanical sensor for intracranial pressure monitoring. Currently, the authors studied the scientific and technical knowledge in this field, as well as develop and test a prototype of microoptomechanical sensor for intracranial pressure (ICP) monitoring

21 CFR 868.5120 - Anesthesia conduction catheter.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to inject...

Experimental Investigation Of Biogas-Biodiesel Dual Fuel Combustion In A Diesel Engine

Directory of Open Access Journals (Sweden)

Ramesha D. K.

2015-06-01

Full Text Available This study is an attempt at achieving diesel fuel equivalent performance from diesel engines with maximum substitution of diesel with renewable fuels. In this context the study has been designed to analyze the influence of B20 algae biodiesel as a pilot fuel in a biodiesel biogas dual fuel engine, and results are compared to those of biodiesel and diesel operation at identical engine settings. Experiments were performed at various loads from 0 to 100 % of maximum load at a constant speed of 1500 rpm. In general, B20 algae biodiesel is compatible with diesel in terms of performance and combustion characteristics. Dual fuel mode operation displays lower thermal efficiency and higher fuel consumption than for other fuel modes of the test run across the range of engine loads. Dual fuel mode displayed lower emissions of NOx and Smoke opacity while HC and CO concentrations were considerably higher as compared to other fuels. In dual fuel mode peak pressure and heat release rate were slightly higher compared to diesel and biodiesel mode of operation for all engine loads.

Agile and Bright Intracardiac Catheters

NARCIS (Netherlands)

M. Pekař (Martin)

2017-01-01

markdownabstractIntracardiac imaging catheters represent unique instruments to diagnose and treat a diseased heart. While there are imminent advances in medical innovation, many of the commercially available imaging catheters are outdated. Some of them have been designed more than 20 years and

Reproducibility of trabecular bone score with different scan modes using dual-energy X-ray absorptiometry: a phantom study

Energy Technology Data Exchange (ETDEWEB)

Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Pastor Lopez, Maria Juana; Ulivieri, Fabio M. [Servizio di Medicina Nucleare, Ospedale Maggiore, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Milano (Italy); Mai, Alessandro [Universita degli Studi di Milano, Tecniche di Radiologia Medica, per Immagini e Radioterapia, Milano (Italy); Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

2014-08-12

The trabecular bone score (TBS) accounts for the bone microarchitecture and is calculated on dual-energy X-ray absorptiometry (DXA). We estimated the reproducibility of the TBS using different scan modes compared to the reproducibility bone mineral density (BMD). A spine phantom was used with a Hologic QDR-Discovery A densitometer. For each scan mode [fast array, array, high definition (HD)], 25 scans were automatically performed without phantom repositioning; a further 25 scans were performed with phantom repositioning. For each scan, the TBS was obtained. The coefficient of variation (CoV) was calculated as the ratio between standard deviation and mean; percent least significant change (LSC%) as 2.8 x CoV; reproducibility as the complement to 100 % of LSC%. Differences among scan modes were assessed using ANOVA. Without phantom repositioning, the mean TBS (mm{sup -1}) was: 1.352 (fast array), 1.321 (array), and 1.360 (HD); with phantom repositioning, it was 1.345, 1.332, and 1.362, respectively. Reproducibility of the TBS without phantom repositioning was 97.7 % (fast array), 98.3 % (array), and 98.2 % (HD); with phantom repositioning, it was 97.9 %, 98.7 %, and 98.4 %, respectively. LSC% was ≤2.26 %. Differences among scan modes were all statistically significant (p ≤ 0.019). Reproducibility of BMD was 99.1 % with all scan modes, while LSC% was from 0.86 % to 0.91 %. Reproducibility error of the TBS was 2-3-fold higher than that of BMD. Although statistically significant, differences in TBS among scan modes were within the highest LSC%. Thus, the three scan modes can be considered interchangeable. (orig.)

21 CFR 876.5030 - Continent ileostomy catheter.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a form...

FAQs about Catheter-Associated Urinary Tract Infection

Science.gov (United States)

... do so. o Avoid disconnecting the catheter and drain tube. This helps to pre - vent germs from getting into the catheter tube. o The catheter is secured to the leg to prevent pulling on the ... regularly. The drainage spout should not touch any - thing while emptying ...

Studies on the incidence of intracranial haemorrhages and their relation to the delivery by using the cranial computer-tomography (CT) in full-term newborns

International Nuclear Information System (INIS)

Brockerhoff, P.; Brand, M.; Ludwig, B.

1981-01-01

The cranial computer-tomography is a new non-invasive method for the diagnosis of perinatal intracranial haemorrhage. Among 80 neonates, who were examined by CT after delivery at term between the 3. and 5. day of life, there were 43 newborns without any neurological symptom. These were examined voluntarily with the permission of their parents. A significant correlation between the CT-finding of an intracranial haemorrhage and the neurological observations was found, whereas there was no relation to the mode of delivery. Parity, birth weight, Apgar-score, cord blood-pH did not correspond to the CT-findings. An extremely short duration of the second stage of labor in spontaneous delivery seems to increase the risk of perinatal intracranial haemorrhage. (orig.) [de

The impact of left and right intracranial tumors on picture and word recognition memory.

Science.gov (United States)

Goldstein, Bram; Armstrong, Carol L; Modestino, Edward; Ledakis, George; John, Cameron; Hunter, Jill V

2004-02-01

This study investigated the effects of left and right intracranial tumors on picture and word recognition memory. We hypothesized that left hemispheric (LH) patients would exhibit greater word recognition memory impairment than right hemispheric (RH) patients, with no significant hemispheric group picture recognition memory differences. The LH patient group obtained a significantly slower mean picture recognition reaction time than the RH group. The LH group had a higher proportion of tumors extending into the temporal lobes, possibly accounting for their greater pictorial processing impairments. Dual coding and enhanced visual imagery may have contributed to the patient groups' similar performance on the remainder of the measures.

The dangers of long-term catheter drainage.

Science.gov (United States)

Lowthian, P

There are many dangers associated with long-term urinary bladder drainage by catheter. For various reasons, the choice of catheter is important, and its initial insertion can be particularly hazardous. All catheterizations should, however, be safer when there is some urine (or other fluid) in the bladder. The appropriate choice of drainage system attached to the catheter can delay bacterial invasion of the bladder. Great care is needed to prevent blockage of the system, particularly when bacteriuria is present. Recent evidence indicates that some bacteria encourage the development of encrustations, so that, in some circumstances, catheters may become blocked within 24 hours. This, together with other considerations, strongly suggests that indwelling catheters should be changed at intervals of not more than 5 days. The practical implications of this are considered, as are the benefits that may accrue. Accidental catheter traction is another danger, and some possible methods of avoiding this are discussed. Finally, the need for a new kind of drainage-bag support is highlighted.

Recent Advances in Cancer Therapy Based on Dual Mode Gold Nanoparticles

Directory of Open Access Journals (Sweden)

Ellas Spyratou

2017-12-01

Full Text Available Many tumor-targeted strategies have been used worldwide to limit the side effects and improve the effectiveness of therapies, such as chemotherapy, radiotherapy (RT, etc. Biophotonic therapy modalities comprise very promising alternative techniques for cancer treatment with minimal invasiveness and side-effects. These modalities use light e.g., laser irradiation in an extracorporeal or intravenous mode to activate photosensitizer agents with selectivity in the target tissue. Photothermal therapy (PTT is a minimally invasive technique for cancer treatment which uses laser-activated photoabsorbers to convert photon energy into heat sufficient to induce cells destruction via apoptosis, necroptosis and/or necrosis. During the last decade, PTT has attracted an increased interest since the therapy can be combined with customized functionalized nanoparticles (NPs. Recent advances in nanotechnology have given rise to generation of various types of NPs, like gold NPs (AuNPs, designed to act both as radiosensitizers and photothermal sensitizing agents due to their unique optical and electrical properties i.e., functioning in dual mode. Functionalized AuNPS can be employed in combination with non-ionizing and ionizing radiation to significantly improve the efficacy of cancer treatment while at the same time sparing normal tissues. Here, we first provide an overview of the use of NPs for cancer therapy. Then we review many recent advances on the use of gold NPs in PTT, RT and PTT/RT based on different types of AuNPs, irradiation conditions and protocols. We refer to the interaction mechanisms of AuNPs with cancer cells via the effects of non-ionizing and ionizing radiations and we provide recent existing experimental data as a baseline for the design of optimized protocols in PTT, RT and PTT/RT combined treatment.

Clinical validation of dual-source dual-energy computed tomography (DECT) for coronary and valve imaging in patients undergoing trans-catheter aortic valve implantation (TAVI).

Science.gov (United States)

Mahoney, R; Pavitt, C W; Gordon, D; Park, B; Rubens, M B; Nicol, E D; Padley, S P

2014-08-01

To assess the validity of virtual non-contrast (VNC) reconstructions for coronary artery calcium (CACS) and aortic valve calcium scoring (AVCS) in patients undergoing trans-catheter aortic valve implantation (TAVI). Twenty-three consecutive TAVI patients underwent a three-step computed tomography (CCT) acquisition: (1) traditional CACS; (2) dual-energy (DE) CT coronary angiogram (CTCA); and (3) DE whole-body angiogram. Linear regression was used to model calcium scores generated from VNC images with traditional scores to derive a conversion factor [2.2 (95% CI: 1.97-2.58)]. The effective radiation dose for the TAVI protocol was compared to a standard control group. Bland-Altman analysis and weighted k-statistic were used to assess inter-method agreement for absolute score and risk centiles. CACS and AVCS from VNC reconstructions correlated well with traditional scores (r = 0.94 and r = 0.86; both p VNC and non-contrast coronary calcium scores [mean difference -71.8 (95% limits of agreement -588.7 to 445.1)], with excellent risk stratification into risk centiles (k = 0.99). However, the agreement was weaker for the aortic valve [mean difference -210.6 (95% limits of agreement -1233.2 to 812)]. Interobserver variability was excellent for VNC CACS [mean difference of 6 (95% limits of agreement 134.1-122.1)], and AVCS [mean difference of -16.4 (95% limits of agreement 576 to -608.7)]. The effective doses for the DE TAVI protocol was 16.4% higher than standard TAVI protocol (22.7 versus 19.5 mSv, respectively) accounted for by the DE CTCA dose being 47.8% higher than that for a standard CTCA [9.9 (5.6-14.35) versus 6.7 (1.17-13.72) mSv; p VNC reconstructions. However, the dose from DE CTCA is significantly greater than the standard single-energy CTCA precluding the use of this technology in routine clinical practice. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Biological safety evaluation of the modified urinary catheter

Energy Technology Data Exchange (ETDEWEB)

Kowalczuk, Dorota, E-mail: dorota.kowalczuk@umlub.pl [Department of Medicinal Chemistry, Medical University of Lublin, Jaczewskiego 4, 20-090 Lublin (Poland); Przekora, Agata; Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodzki 1, 20-093 Lublin (Poland)

2015-04-01

The purpose of this study was to evaluate in vitro safety of the novel tosufloxacin (TOS)-treated catheters with the prolonged antimicrobial activity. The test samples of silicone latex catheter were prepared by the immobilization of TOS on chitosan (CHIT)-coated catheter by means of covalent bonds and non-covalent interactions. Each step of the modification process of catheter surface was observed using ATR–Fourier transform infrared spectroscopy. In vitro cytotoxicity of the modified and unmodified catheters was assessed by direct and indirect tests in accordance with ISO standards using green monkey kidney (GMK) cell line. The MTT, lactate dehydrogenase activity (LDH), WST-8, Sulforhodamine B (SRB) test results and microscopic observation clearly indicated that unmodified silicone latex catheters decrease cell metabolic activity, act as a cytotoxic agent causing cell lysis and induce cell death through necrotic or apoptotic process. We suggest that chitosan coat with TOS immobilized limits leaching of harmful agents from silicone latex material, which significantly enhances survivability of GMK cells and therefore is quite a good protection against the cytotoxic effect of this material. - Highlights: • Characterization of the novel antimicrobial urinary catheters • Monitoring of the catheter modification by FTIR analysis • Confirmation of high cytotoxicity of latex-based catheter used in urological practice • Chitosan-coated and tosufloxacin-treated catheter is less toxic than the untreated one. • The proposed surface modification protects cells against latex-induced death.

Comparison of prospective electrocardiography-gating high-pitch mode and without electrocardiography-synchronization high-pitch mode acquisition for the image quality and radiation doses of the aortic using dual-source CT

International Nuclear Information System (INIS)

Li Jian; Huan Yi; Zhao Hongliang; Wang Ying; Liu Ying; Wei Mengqi; Shi Mingguo; Zheng Minwen

2013-01-01

Objective: To evaluate the application of prospective ECG-gating Flash spiral scan mode dual-source CT in aortography, and compare it's image quality and radiation dose with without ECG-synchronization high-pitch spiral scanning mode. Methods: Fifty consecutive patients (Group A) with suspected aortic dissection or after operations for the aortic dissection were scanned with prospective ECG-gated high-pitch scan and another 50 consecutive patients (Group B) were analyzed by non-ECG-gated high-pitch scan. Image quality of the aortic was assessed by two independent readers. Image noise was measured, radiation dose estimates were calculated. The imaging quality of the aortic and the radiation dose were compared with Mann-whitney U and t test. Results: The average image quality score [(1.18 ± 0.40) in group A and (1.23 ± 0.31) in group B] showed no significant difference between group A and group B (U = 1.20, P = 0.23). The mean radiation dose of group A was lower than that of group B [(1.49 ± 0.38) mSv in group A, (2.79 ± 0.54) mSv in group B, t = 13.677, P < 0.05]. Conclusion: Prospective ECG-gated dual source CT Flash spiral scanning with low radiation dose and good image quality in the aortic dissection with high value of clinical application. (authors)

A comparative study on dual colour soft aperture cascaded second ...

Indian Academy of Sciences (India)

2014-02-09

Feb 9, 2014 ... second-order mode-locking with different nonlinear optical crystals ... delivers stable dual wavelength cw mode-locked pulse train with pulse ... Mode-locking; ultrafast processes; optical susceptibility; frequency conversion;.

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

Energy Technology Data Exchange (ETDEWEB)

Sun, Kai; Ma, Rui; Wang, Li Jun [Dept. of Radiology, Baotou Central Hospital, Baotou (China); Li, Li Gang; Chen, Jiu Hong [CT BM Clinic Marketing, Siemens Healthcare, Beijing (China)

2012-11-15

To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 {+-} 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 {+-} 0.306 [group A] vs. 1.084 {+-} 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 {+-} 0.16 mSv in group A and 7.1 {+-} 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

International Nuclear Information System (INIS)

Sun, Kai; Ma, Rui; Wang, Li Jun; Li, Li Gang; Chen, Jiu Hong

2012-01-01

To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio.

Science.gov (United States)

Spencer, Timothy R; Mahoney, Keegan J

2017-11-01

In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33 to 45% of the vessels diameter. There has been evidence on larger diameter catheters and increased thrombosis risk in recent literature, while insufficient information established on what relationship to vessel size is appropriate for any intra-vascular device. Earlier references to clinical standards and guidelines did not clearly address vessel size in relation to the area consumed or external catheter diameter. The aim of this manuscript is to present catheter-related thrombosis evidence and develop a standardized process of ultrasound-guided vessel assessment, integrating CVR, Virchow's triad phenomenon and vessel health and preservation strategies, empowering an evidence-based approach to device placement. Through review, calculation and assessment on the areas of the 33 and 45% rule, a preliminary clinical tool was developed to assist clinicians make cognizant decisions when placing intravascular devices relating to target vessel size, focusing on potential reduction in catheter-related thrombosis. Increasing the understanding and utilization of CVRs will lead to a safer, more consistent approach to device placement, with potential thrombosis reduction strategies. The future of evidence-based data relies on the clinician to capture accurate vessel measurements and device-related outcomes. This will lead to a more dependable data pool, driving the relationship of catheter-related thrombosis and vascular assessment.

A dual-mode nanosensor based on carbon quantum dots and gold nanoparticles for discriminative detection of glutathione in human plasma.

Science.gov (United States)

Shi, Yupeng; Pan, Yi; Zhang, Heng; Zhang, Zhaomin; Li, Mei-Jin; Yi, Changqing; Yang, Mengsu

2014-06-15

Glutathione (GSH) plays key roles in biological systems and serves many cellular functions. Since biothiols all incorporate thiol, carboxylic and amino groups, discriminative detection of GSH over cysteine (Cys) and homocysteine (Hcy) is still challenging. We herein report a dual-mode nanosensor with both colorimetric and fluorometric readout based on carbon quantum dots and gold nanoparticles for discriminative detection of GSH over Cys/Hcy. The proposed sensing system consists of AuNPs and fluorescent carbon quantum dots (CQDs), where CQDs function as fluorometric reporter, and AuNPs serve a dual function as colorimetric reporter and fluorescence quencher. The mechanism of the nanosensor is based on two distance-dependent phenomenons, color change of AuNPs and FRET. Through controlling the surface properties of as-prepared nanoparticles, the addition of CQDs into AuNPs colloid solution might induce the aggregation of AuNPs and CQDs, leading to AuNPs color changing from red to blue and CQDs fluorescence quench. However, the presence of GSH can protect AuNPs from being aggregated and enlarge the inter-particle distance, which subsequently produces color change and fluorescent signal recovery. The nanosensor described in this report reflects on its simplicity and flexibility, where no further surface functionalization is required for the as-prepared nanoparticles, leading to less laborious and more cost-effective synthesis. The proposed dual-mode nanosensor demonstrated highly selectivity toward GSH, and allows the detection of GSH as low as 50 nM. More importantly, the nanosensor could not only function in aqueous solution for GSH detection with high sensitivity but also exhibit sensitive responses toward GSH in complicated biological environments, demonstrating its potential in bioanalysis and biodection, which might be significant in disease diagnosis in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

Stent-assisted angioplasty for intracranial atherosclerosis

International Nuclear Information System (INIS)

Nakahara, Toshinori; Sakamoto, Shigeyuki; Hamasaki, Osamu; Sakoda, Katsuaki

2002-01-01

We report on two patients with intracranial atherosclerosis of the carotid artery or vertebral artery treated with stent-assisted angioplasty. Both patients have severe intracranial atherosclerosis (>70%) with refractory symptoms despite optimal medical treatment. In both patients, a coronary balloon-expandable stent was successfully placed using a protective balloon technique without procedural complications. The patients were asymptomatic and neurologically intact at a mean clinical follow-up of 13 months. Follow-up angiograms did not show restenosis 3 or 4 months after procedure, respectively. Stent-assisted angioplasty for intracranial atherosclerosis in the elective patient has proven effective, with an acceptable low rate of morbidity and mortality. (orig.)

Syphilis mimicking idiopathic intracranial hypertension

DEFF Research Database (Denmark)

Yri, Hanne; Wegener, Marianne; Jensen, Rigmor

2011-01-01

Idiopathic intracranial hypertension (IIH) is a condition of yet unknown aetiology affecting predominantly obese females of childbearing age. IIH is a diagnosis of exclusion as raised cerebrospinal fluid pressure may occur secondary to numerous other medical conditions. An atypical phenotype or a...... antibiotic treatment, signs and symptoms of elevated intracranial pressure resolved completely. Syphilis is a rare, but very important, differential diagnosis that in this case was clinically indistinguishable from IIH....

Low-angled peripheral intravenous catheter tip placement decreases phlebitis.

Science.gov (United States)

Tanabe, Hidenori; Murayama, Ryoko; Yabunaka, Koichi; Oe, Makoto; Takahashi, Toshiaki; Komiyama, Chieko; Sanada, Hiromi

2016-11-02

Peripheral intravenous catheters (PIVCs) are frequently removed due to phlebitis. We hypothesized that catheters made of polyurethane, which is more flexible than Teflon, would decrease phlebitis, and that flexibility could be estimated by measuring the catheter-tip angle. Ultrasonography in two groups of patients with different catheter types was then used to compare catheter-tip angles and phlebitis. Observational studies were carried out at a medical ward in a university hospital. Infusion therapy was administered to one group of patients in 2014 using Teflon catheters (control group, n = 200), and to another group of patients in 2015 using polyurethane catheters (investigational group, n = 207). The symptoms were assessed according to a scale developed by the Infusion Nurses Society. Long-axis ultrasonography images taken immediately before catheter removal were used to measure the angle between the central line of the catheter within 2 mm from the distal point and a tangent to the vessel wall. There were no significant differences between the two groups with respect to sex, age, and medical diagnosis. In the control and investigational groups, the rates of phlebitis were 37% (73/200) and 17% (36/207), respectively (pPhlebitis occurred more frequently when the catheter-tip was placed at angle >5.8°. The frequency of phlebitis was lower in the polyurethane, in which the catheter was placed at lower angle, almost parallel to the vessel. Our results will aid in developing new catheters and in improving PIVC-securement techniques.

Paravertebral block catheter breakage by electrocautery during thoracic surgery.

Science.gov (United States)

Saeki, Noboru; Sugimoto, Yuki; Mori, Yoko; Kato, Takahiro; Miyoshi, Hirotsugu; Nakamura, Ryuji; Koga, Tomomichi

2017-06-01

Advantages of thoracic paravertebral analgesia (TPA) include placement of the catheter closer to the surgical field; however, the catheter can become damaged during the operation. We experienced a case of intraoperative TPA catheter breakage that prompted us to perform an experiment to investigate possible causes. A 50-year-old male underwent a thoracoscopic lower lobectomy under general anesthesia with TPA via an intercostal approach. Following surgery, it was discovered that the catheter had become occluded, as well as cut and fused, so we reopened the incision and removed the residual catheter. From that experience, we performed an experiment to examine electrocautery-induced damage in normal (Portex™, Smith's Medical), radiopaque (Perifix SoftTip™, BBraun), and reinforced (Perifix FX™, BBraun) epidural catheters (n = 8 each). Chicken meat was penetrated by each catheter and then cut by electrocautery. In the normal group, breakage occurred in 8 and occlusion in 6 of the catheters, and in the radiopaque group breakage occurred in 8 and occlusion in 7. In contrast, breakage occurred in only 3 and occlusion in none in the reinforced group, with the 5 without breakage remaining connected only by the spring coil. Furthermore, in 7 of the reinforced catheters, electric arc-induced thermal damage was observed at the tip of the catheter. A TPA catheter for thoracic surgery should be inserted via the median approach, or it should be inserted after surgery to avoid catheter damage during surgery.

Intracranial meningiomas in the present era of modern neuroimaging

African Journals Online (AJOL)

Background: Intracranial meningioma is the most common primary, intracranial, extra-axial neoplasm. It is mesenchymal in origin and arises from meningothelial cells of arachnoid villi of meninges. Objectives: To re-emphasize the regional anatomic localisation and diagnostic radiological features of intracranial ...

Spinal canal extension of hyperalimentation catheter without neurologic sequela

International Nuclear Information System (INIS)

Glasier, M.; Arkansas Children's Hospital, Little Rock; Hassell, D.R.

1989-01-01

An attempt at placement of a left femoral vein hyperalimentation catheter resulted in entrance of the catheter into the spinal canal. Catheter location was documented by injections of nonionic contrast material into the catheter without neurologic sequellae. (orig.)

Incidence of phlebitis associated with the use of peripheral IV catheter and following catheter removal

Directory of Open Access Journals (Sweden)

Janete de Souza Urbanetto

Full Text Available ABSTRACT Objective: to investigate the incidence of phlebitis and its association with risk factors when using peripheral IV catheters (PIC and following their removal - (post-infusion phlebitis in hospitalized adults. Method: a cohort study of 171 patients using PIC, totaling 361 punctures. Sociodemographic variables and variables associated with the catheter were collected. Descriptive and analytical statistical analyses were performed. Results: average patient age was 56.96 and 51.5% of the sample population was male. The incidence of phlebitis was 1.25% while using PIC, and 1.38% post-infusion. The incidence of phlebitis while using PIC was associated with the length of time the catheter remained in place, whereas post-infusion phlebitis was associated with puncture in the forearm. Ceftriaxone, Clarithromycin and Oxacillin are associated with post-infusion phlebitis. Conclusions: this study made it possible to investigate the association between risk factors and phlebitis during catheter use and following its removal. The frequency of post-infusion phlebitis was larger than the incidence of phlebitis with the catheter in place, with Phlebitis Grade III and II being the most frequently found in each of these situations, respectively. Aspects related to post-infusion phlebitis can be explained, given the limited number of studies addressing this theme from this perspective.

Epidemiology and genetics of intracranial aneurysms

International Nuclear Information System (INIS)

Caranci, F.; Briganti, F.; Cirillo, L.; Leonardi, M.; Muto, M.

2013-01-01

Intracranial aneurysms are acquired lesions (5–10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3–p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3–p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2

Epidemiology and genetics of intracranial aneurysms

Energy Technology Data Exchange (ETDEWEB)

Caranci, F., E-mail: ferdinandocaranci@libero.it [Unit of Neuroradiology, Department of Diagnostic Radiology and Radiotherapy, Federico II University, Naples (Italy); Briganti, F., E-mail: frabriga@unina.it [Unit of Neuroradiology, Department of Diagnostic Radiology and Radiotherapy, Federico II University, Naples (Italy); Cirillo, L.; Leonardi, M. [Neuroradiology service, Bellaria Hospital, Bologna (Italy); Muto, M., E-mail: mutomar@tiscali.it [Neuroradiology Service Cardarelli Hospital Naples (Italy)

2013-10-01

Intracranial aneurysms are acquired lesions (5–10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3–p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3–p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2

Canine Intracranial Meningioma: Case report

Directory of Open Access Journals (Sweden)

José Ricardo Gomes de Carvalho

2016-11-01

Full Text Available ABSTRACT. Carvalho J.R.G., Vasconcellos C.H.C., Bastos I. P.B., Trajano F.L.C., Costa T.S. & Fernandes J.I [Canine Intracranial Meningioma: Case report.] Meningioma intracraniano canino: Relato de caso. Revista Brasileira de Medicina Veterinária, 38(supl. 3:1- 7, 2016. Programa de Pós-Graduação em Ciências Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465 Km 7, Seropédica, RJ 23.897-000, Brasil, E-mail: vetjulio@yahoo.com.br Intracranial neoplasms usually show their signals in a moderate way, revealing a long background of nonspecific signs, making the diagnosis more difficult. The meningioma is the most common intracranial neoplasm in dogs and cats. Along the years, the Veterinary Medicine has experienced important technological improvements, making it possible the diagnosis of a lot of diseases. Therefore, diseases considered not common in the past, started being diagnosed more frequently, for instance, brain lesions. The objective of this research is to report a case of intracranial meningioma in a Boxer dog that arrived at the Veterinary Hospital of the Federal Rural University of Rio de Janeiro, highlighting its clinical improvement, diagnosis and treatment.

Intracranial hypotension and hypertension in children and adolescents.

Science.gov (United States)

Ozge, Aynur; Bolay, Hayrunnisa

2014-07-01

The specific aim of this review is to report the features of intracranial pressure changes [spontaneous intracranial hypotension (SIH) and idiopathic intracranial hypertension (IIH)] in children and adolescents, with emphasis on the presentation, diagnosis, and treatment modalities. Headache associated with intracranial pressure changes are relatively rare and less known in children and adolescents. SIH is a specific syndrome involving reduced intracranial pressure with orthostatic headache, frequently encountered connective tissue disorders, and a good prognosis with medical management, initial epidural blood patching, and sometimes further interventions may be required. IIH is an uncommon condition in children and different from the disease in adults, not only with respect to clinical features (likely to present with strabismus and stiff neck rather than headache or pulsatile tinnitus) but also different in outcome. Consequently, specific ICP changes of pediatric ages required specific attention both of exact diagnosis and entire management.

Dual-mode fluorophore-doped nickel nitrilotriacetic acid-modified silica nanoparticles combine histidine-tagged protein purification with site-specific fluorophore labeling.

Science.gov (United States)

Kim, Sung Hoon; Jeyakumar, M; Katzenellenbogen, John A

2007-10-31

We present the first example of a fluorophore-doped nickel chelate surface-modified silica nanoparticle that functions in a dual mode, combining histidine-tagged protein purification with site-specific fluorophore labeling. Tetramethylrhodamine (TMR)-doped silica nanoparticles, estimated to contain 700-900 TMRs per ca. 23 nm particle, were surface modified with nitrilotriacetic acid (NTA), producing TMR-SiO2-NTA-Ni2+. Silica-embedded TMR retains very high quantum yield, is resistant to quenching by buffer components, and is modestly quenched and only to a certain depth (ca. 2 nm) by surface-attached Ni2+. When exposed to a bacterial lysate containing estrogen receptor alpha ligand binding domain (ERalpha) as a minor component, these beads showed very high specificity binding, enabling protein purification in one step. The capacity and specificity of these beads for binding a his-tagged protein were characterized by electrophoresis, radiometric counting, and MALDI-TOF MS. ERalpha, bound to TMR-SiO2-NTA-Ni++ beads in a site-specific manner, exhibited good activity for ligand binding and for ligand-induced binding to coactivators in solution FRET experiments and protein microarray fluorometric and FRET assays. This dual-mode type TMR-SiO2-NTA-Ni2+ system represents a powerful combination of one-step histidine-tagged protein purification and site-specific labeling with multiple fluorophore species.

Repositioning of malpositioned or flipped central venous catheters

Energy Technology Data Exchange (ETDEWEB)

Thalhammer, A.; Jacobi, V.; Balzer, J.; Vogl, T.J. [Institute for Diagnostic and Interventional Radiology, Central Radiology Clinic, J.W. Goethe University, Frankfurt am Main (Germany)

2002-03-01

Primary misplaced or secondary flipped implanted catheters are located mostly in the right jugular vein. We demonstrate an effective method to replace fix implanted catheters such as Ports, Grochomg or Hickman catheters. Using a femoral venous approach, replacement into the superior vena cava can easily be done with a Sidewinder 1 catheter which is hooked over the misplaced central venous approach. In all our patients the method was successful. The repositioning technique described is simple, fast and has low costs. We can keep sterile conditions and do not need to solve the catheters' fixation. (orig.)

Guided-Mode-Leaky-Mode-Guided-Mode Fiber Interferometer and Its High Sensitivity Refractive Index Sensing Technology

Directory of Open Access Journals (Sweden)

Qi Wang

2016-06-01

Full Text Available A cascaded symmetrical dual-taper Mach-Zehnder interferometer structure based on guided-mode and leaky-mode interference is proposed in this paper. Firstly, the interference spectrum characteristics of interferometer has been analyzed by the Finite Difference-Beam Propagation Method (FD-BPM. When the diameter of taper waist is 20 μm–30 μm, dual-taper length is 1 mm and taper distance is 4 cm–6 cm, the spectral contrast is higher, which is suitable for sensing. Secondly, experimental research on refractive index sensitivity is carried out. A refractive index sensitivity of 62.78 nm/RIU (refractive index unit can achieved in the RI range of 1.3333–1.3792 (0%~25% NaCl solution, when the sensor structure parameters meet the following conditions: diameter of taper waist is 24 μm, dual-taper length is 837 μm and taper distance is 5.5 cm. The spectrum contrast is 0.8 and measurement resolution is 1.6 × 10−5 RIU. The simulation analysis is highly consistent with experimental results. Research shows that the sensor has promising application in low RI fields where high-precision measurement is required due to its high sensitivity and stability.

Valid and efficient manual estimates of intracranial volume from magnetic resonance images

International Nuclear Information System (INIS)

Klasson, Niklas; Olsson, Erik; Rudemo, Mats; Eckerström, Carl; Malmgren, Helge; Wallin, Anders

2015-01-01

Manual segmentations of the whole intracranial vault in high-resolution magnetic resonance images are often regarded as very time-consuming. Therefore it is common to only segment a few linearly spaced intracranial areas to estimate the whole volume. The purpose of the present study was to evaluate how the validity of intracranial volume estimates is affected by the chosen interpolation method, orientation of the intracranial areas and the linear spacing between them. Intracranial volumes were manually segmented on 62 participants from the Gothenburg MCI study using 1.5 T, T 1 -weighted magnetic resonance images. Estimates of the intracranial volumes were then derived using subsamples of linearly spaced coronal, sagittal or transversal intracranial areas from the same volumes. The subsamples of intracranial areas were interpolated into volume estimates by three different interpolation methods. The linear spacing between the intracranial areas ranged from 2 to 50 mm and the validity of the estimates was determined by comparison with the entire intracranial volumes. A progressive decrease in intra-class correlation and an increase in percentage error could be seen with increased linear spacing between intracranial areas. With small linear spacing (≤15 mm), orientation of the intracranial areas and interpolation method had negligible effects on the validity. With larger linear spacing, the best validity was achieved using cubic spline interpolation with either coronal or sagittal intracranial areas. Even at a linear spacing of 50 mm, cubic spline interpolation on either coronal or sagittal intracranial areas had a mean absolute agreement intra-class correlation with the entire intracranial volumes above 0.97. Cubic spline interpolation in combination with linearly spaced sagittal or coronal intracranial areas overall resulted in the most valid and robust estimates of intracranial volume. Using this method, valid ICV estimates could be obtained in less than five

Idiopathic Intracranial Hypertension – Pathophysiology Based on Case Series

Directory of Open Access Journals (Sweden)

Ljubisavljević Srdjan

2016-09-01

Full Text Available According to the definition, idiopathic intracranial hypertension (IIH is a pathological state characterized by an increase in intracranial pressure; however, there are no obvious intracranial pathological processes. The pathophysiology of this disorder is not clear, although there are many reports related to it.

CATHETER DURATION AND THE RISK OF SEPSIS IN PREMATURE BABIES WITH UMBILICAL VEIN CATHETERS

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Hartojo Hartojo

2012-01-01

Full Text Available Umbilical catheters are frequently required in the management of severely ill premature babies. The risk of complications may increase with duration of UVC use. Objective: To determine whether the risk of central line-associated bloodstream infections (CLA-BSIs and sepsis remained constant over the duration of umbilical vein catheters (UVCs in high-risk premature neonates. Methods:retrospective analysis. The data were collected from the medical record of high risk premature neonates who had a UVC placed in neonatal care unit of Husada Utama Hospital between April 1st 2008 to April 30th 2011 with purposive sampling. Catheter duration was observed before and after 14 days on placement. Blood and UVC culture was performed to establish the risk of CLA-BSIs and sepsis. Chi-square and logistic regression analysis were performed in the laboratorium data. Result: A total 44 high risk premature babies with UVCs were enrolled (sepsis group: n = 23 and non sepsis group: n = 21. Baseline demographics were similar between the groups. 15 babies in sepsis group have UVCs duration > 14 days, and 8 babies have UVCs 14 days show blood culture performance in 11 babies with positive evidence, UVCs culture performance is negative in 18 babies (p = 0.456. Burkholderia cepacia and Klebsiella pneumonia mostly appeared in blood culture performance. 25% of UVC culture performance shows Pseudomonas aeroginosa. Conclusions: The catheter duration have no significant difference in risk of sepsis in premature babies with Umbilical Vein Catheters.

Intracranial cavernous angioma

International Nuclear Information System (INIS)

Yuhi, Fumiaki; Gondou, Masazumi; Sasahira, Masahiro; Ichitsubo, Hidenori; Asakura, Tetsuhiko.

1986-01-01

The present authors have experienced 2 cases of intracranial cavernous angioma. Of these cases, one was admitted because of generalized convulsions, while the other was admitted because of headache. In both cases, neither plain X-ray films nor carotid angiography showed any abnormality, but computerized tomography (CT) revealed a slightly high-density area which was not enhanced with contrast media. Histologically, the tumors had many vascular cavities with walls lined with a single layer of endothelial cells and had no neural tissue between the vascular cavities; therefore, they were diagnosed as cases of cavernous angioma. The authors discussed the radiological findings of the intracranial cavernous angioma with a review of the literature and stressed the role of computerized tomography in the diagnosis of cavernous angioma. (author)

Spaceflight-Induced Intracranial Hypertension.

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Michael, Alex P; Marshall-Bowman, Karina

2015-06-01

Although once a widely speculated about and largely theoretical topic, spaceflight-induced intracranial hypertension has gained acceptance as a distinct clinical phenomenon, yet the underlying physiological mechanisms are still poorly understood. In the past, many terms were used to describe the symptoms of malaise, nausea, vomiting, and vertigo, though longer duration spaceflights have increased the prevalence of overlapping symptoms of headache and visual disturbance. Spaceflight-induced visual pathology is thought to be a manifestation of increased intracranial pressure (ICP) because of its similar presentation to cases of known intracranial hypertension on Earth as well as the documentation of increased ICP by lumbar puncture in symptomatic astronauts upon return to gravity. The most likely mechanisms of spaceflight-induced increased ICP include a cephalad shift of body fluids, venous outflow obstruction, blood-brain barrier breakdown, and disruption to CSF flow. The relative contribution of increased ICP to the symptoms experienced during spaceflight is currently unknown, though other factors recently posited to contribute include local effects on ocular structures, individual differences in metabolism, and the vasodilator effects of carbon dioxide. This review article attempts to consolidate the literature regarding spaceflight-induced intracranial hypertension and distinguish it from other pathologies with similar symptomatology. It discusses the proposed physiological causes and the pathological manifestations of increased ICP in the spaceflight environment and provides considerations for future long-term space travel. In the future, it will be critical to develop countermeasures so that astronauts can participate at their peak potential and return safely to Earth.

Biotelemetric Wireless Intracranial Pressure Monitoring: An In Vitro Study

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Mohammad H. Behfar

2015-01-01

Full Text Available Assessment of intracranial pressure (ICP is of great importance in management of traumatic brain injuries (TBIs. The existing clinically established ICP measurement methods require catheter insertion in the cranial cavity. This increases the risk of infection and hemorrhage. Thus, noninvasive but accurate techniques are attractive. In this paper, we present two wireless, batteryless, and minimally invasive implantable sensors for continuous ICP monitoring. The implants comprise ultrathin (50 μm flexible spiral coils connected in parallel to a capacitive microelectromechanical systems (MEMS pressure sensor. The implantable sensors are inductively coupled to an external on-body reader antenna. The ICP variation can be detected wirelessly through measuring the reader antenna’s input impedance. This paper also proposes novel implant placement to improve the efficiency of the inductive link. In this study, the performance of the proposed telemetry system was evaluated in a hydrostatic pressure measurement setup. The impact of the human tissues on the inductive link was simulated using a 5 mm layer of pig skin. The results from the in vitro measurement proved the capability of our developed sensors to detect ICP variations ranging from 0 to 70 mmHg at 2.5 mmHg intervals.

Development of intracranial hypertension after surgical management of intracranial arachnoid cyst: report of three cases and review of the literature.

LENUS (Irish Health Repository)

Kaliaperumal, Chandrasekaran

2013-11-12

To describe three cases of delayed development of intracranial hypertension (IH) after surgical treatment of intracranial arachnoid cyst, including the pathogenesis of IH and a review of the literature.

Obstruction of peritoneal dialysis catheter is associated with catheter type and independent of omentectomy: A comparative data analysis from a transplant surgical and a pediatric surgical department.

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Radtke, Josephine; Schild, Raphael; Reismann, Marc; Ridwelski, Robert-Richard; Kempf, Caroline; Nashan, Bjoern; Rothe, Karin; Koch, Martina

2018-04-01

Peritoneal dialysis (PD) catheter occlusion is a common complication with up to 36% of catheter obstructions described in the literature. We present a comparison of complications and outcome after implantation of PD catheters in a transplant surgical and a pediatric surgical department. We retrospectively analyzed 154 PD catheters, which were implanted during 2009-2015 by transplant surgeons (TS, University Medical Center Hamburg-Eppendorf, Germany, n=85 catheters) and pediatric surgeons (PS, Charité University Medicine Berlin, Germany, n=69 catheters) in 122 children (median (range) age 3.0 (0.01-17.1) years) for acute (n=65) or chronic (n=89) renal failure. All catheters were one-cuffed or double-cuffed curled catheters, except that straight catheters were implanted into smaller children (n=19) by TS in Hamburg. Patient characteristics and operation technique did not differ between the departments. Peritonitis was the most common complication (33 catheters, 21.4%). Leakage (n=18 catheters, 11.7%) occurred more often in children weighing <10kg (p<0.001). The incidence of obstruction and dysfunction was significantly higher in catheters used in PS than catheters used in TS (30.4% vs. 11.8%, p=0.004). Omentectomy did not reduce the incidence of catheter obstruction (p=1.0). Perforation at the catheter tips was larger and appeared to be rougher in catheters used in PS than the catheters in TS. The type of catheter and presumably the type of perforation at the catheter tip may influence the incidence of peritoneal dialysis catheter obstruction. Copyright © 2017 Elsevier Inc. All rights reserved.

Interatrial septum thickness and difficulty with transseptal puncture during redo catheter ablation of atrial fibrillation.

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Tomlinson, David R; Sabharwal, Nikant; Bashir, Yaver; Betts, Timothy R

2008-12-01

Patients undergoing catheter ablation for atrial fibrillation (AF) frequently require redo procedures, but there are no data reporting interatrial septum thickness (IAS) and difficulty during repeat transseptal puncture (TSP). Patients undergoing two separate AF ablation procedures had preprocedural fossa ovalis (FO) thickness measured using transesophageal echocardiography (TEE). "Difficult" TSP was defined by two observers as requiring excessive force, or conversion to TEE guidance. The study comprised 42 patients (37 male) with mean+/-SD age 55+/-9 years. Mean FO thickness was significantly greater at the time of redo TSP (2.2+/-1.6 mm vs 2.6+/-1.5 mm at redo, P=0.03); however, this finding was limited to those who underwent initial dual transseptal sheath procedures, FO thickness 2.0+/-1.5 mm and 2.5+/-1.4 mm for TEE 1 and 2, respectively (P=0.048). There was a trend for more frequent difficult redo TSP procedures, 7/42 (17%; 95% confidence interval [CI] 8-31) redo, versus 4/42 (10%; 95% CI 3-23) first TSP. On univariate analysis, FO thickness was not predictive of TSP difficulty; the only predictor of difficult redo TSP was diabetes. IAS thickness at the FO increased following catheter ablation of AF, yet on subgroup analysis this was limited to initial procedures utilizing dual transseptal sheaths. There was a trend toward more frequent difficulty during redo TSP, yet this was not associated with FO thickening. Diabetes may predispose to difficulty during redo TSP; this finding requires confirmation in a larger study population.

Catheter Occlusion in Home Infusion: The Influence of Needleless Connector Design on Central Catheter Occlusion.

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Williams, Ann

Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.

Attitudes Towards Catheter Ablation for Atrial Fibrillation

DEFF Research Database (Denmark)

Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis

2015-01-01

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians´ attitudes towards catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish...... cardiologists towards catheter ablation for AF, using a nationwide survey. METHODS AND RESULTS: We developed a purpose-designed questionnaire to evaluate attitudes towards catheter ablation for AF that was sent to all Danish cardiologists (n = 401; response n = 272 (67.8%)). There was no association between...... attitudes towards ablation and the experience or age of the cardiologist with respect to patients with recurrent AF episodes with a duration of 7 days and/or need for cardioversion. The majority (69%) expected a recurrence of AF after catheter ablation in more than 30% of the cases...

MRI diagnosis of intracranial tuberculosis (73 cases report)

International Nuclear Information System (INIS)

Zeng Qingyong; Li Xin; He Zhihui; Cheng Chuanhu; Deng Kaijun; Deng Ming

2008-01-01

Objective: To assess the MRI features, classification and diagnostic value for intracranial tuberculosis. Methods MRI findings of 73 patients suffering from intracranial tuberculosis proved by pathology or clinic were analyzed respectively. Among the total 73 patients, 39 cases were tuberculosis meningitis, 12 cases simple intracranial tuberculoma, while 22 cases were tuberculoma combining with meningitis. Results: The MRI features of tuberculous meningitis are cerebral infarction, hydrocephalus, abnormal meningeal and cerebral cistern enhancement. 12 cases mature tuberculoma demon- strated typical features with high or low density on T 2 WI images and ring contrast enhancement; 22 cases non-mature tuberculoma showed focal nodular contrast enhancement with evident cerebral edema. FLAIR is more sensitive to find out focus than T 2 WI. Small lesions could be showed definitively by contrast-enhanced scan. Conclusion: MRI possess typical features in the diagnosis of intracranial tuberculosis. It plays an important role in evaluating location, range, classification of intracranial tuberculosis, and is helpful to clinical treatment. (authors)

Diagnosis of ruptured intracranial aneurysm in acute stage

International Nuclear Information System (INIS)

Yoshiyama, Masataka; Nakagawa, Toshifumi

1980-01-01

Subarachnoid hemorrhage at an acute stage within one day from the onset to the first CT scan was classified into subarachnoid hemorrhage secondary to intracranial aneurysm, subarachnoid hemorrhage of unknown origin and subarachnoid hemorrhage of which angiography could not be carried out, and the first CT findings, the severity, and the prognosis of these subarachnoid hemorrhage were compared and discussed. CT findings of subarachnoid hemorrhage secondary to intracranial aneurysm showed various changes according to progress in the severity with time, and intracranial hematoma, intraventricular clots and ventricular dilatation increased according to progress in the severity. Ruptured intracranial aneurysm in middle cerebral artery, anterior cerebral artery and anterior communicating artery could be found easily by CT, but that in internal carotid artery and vertabral basilar artery was difficult to be detected by CT. When cerebral angiography was carried out repeatedly for ruptured intracranial aneurysm of unknown origin, the time of performance must be consifered with attention to angiospasms or hematoma. (Tsunoda, M.)

Catheter Angiography

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography ...

[Congenital anomalies of cerebral artery and intracranial aneurysm].

Science.gov (United States)

Nakajima, K; Ito, Z; Hen, R; Uemura, K; Matsuoka, S

1976-02-01

It is well known that congenital anomalies such as polycystic kidney, aortic coarctation, Marfan syndrome, Ehler-Danlos syndrome are apt to be complicated by intracranial aneurysms. In this report we attempt to reveal the relation and incidence between cerebrovascular anomalies and intracranial aneurysms. The etiology of aneurysms has been discussed, too. 12 cases of persistent trigeminl artery, 2 cases of persistent hypoglossal artery and 11 cases of fenestration were obtained from 3841 patients who were angiographically examined in our clinic for 5 years. The incidence is 0.31%, 0.05% and 0.29%, respectively. Persistent trigeminal arteries were complicated by 2 cases of intracranial aneurysms and one case of arterivenous malformations (AVM), persistent hypoglossal arteries were complicated by one case of aneurysm, and fenestrations were complicated by 2 cases of aneurysms and one case of AVM. One case of congenital agenesis of right internal carotid artery was obtained which was complicated by aneurysm of anterior communicating artery. Totally, 8 cases of aneurysms and AVM were obtained from 26 cases of cerebrovascular anomalies (incidence 30.8%). On the other hand, thalamic or caudate hemorrhage revealed the highest incidence of complication of intracranial aneurysms among intracerebral hematomas (10.7%). Compared with the incidence of aneurysms between cerebro vascular anomalies (30.8%) and thalamic or caudate hemorrhage (10.7%), the difference is statistically signigicant (P less than 0.05). The cause of intracranial aneurysm has not yet been clarified. But it is well accepted that the defect of tunica media vasorum is most responsible factor as to the occurrence of intracranial aneurysms. We concluded that the genetic error of cerebral vessels including defect of media caused intracranial aneurysms, and this result was supported from the evidence that cerebrovascular anomalies showed statistically high incidence of complication of intracranial aneurysms.

Technique of Peritoneal Catheter Placement under Fluoroscopic Guidance

International Nuclear Information System (INIS)

Abdel-Aal, A.K.; Gaddikeri, S.; Saddekni, S.

2011-01-01

Peritoneal catheters are mainly used for peritoneal dialysis in patients with end-stage renal disease. Other uses of this catheter include intraperitoneal chemotherapy and gene therapy for ovarian cancer and draining of uncontrolled refractory ascites in patients with liver cirrhosis. Traditionally, surgeons place most of these peritoneal catheters either by laparoscopy or open laparotomy. We detail our percutaneous approach to placing peritoneal catheters using fluoroscopic guidance. We emphasize the use of additional ultrasound guidance, including gray scale and color Doppler ultrasound, to determine the safest puncture site and to guide the initial needle puncture in order to avoid bowel perforation and injury to epigastric artery. We present our experience in placing peritoneal catheters using this technique in 95 patients with various indications. Fluoroscopic guided percutaneous placement of peritoneal catheters is a safe, minimally invasive, and effective alternative to open surgical or laparoscopic placement.

Detection of electrophysiology catheters in noisy fluoroscopy images.

Science.gov (United States)

Franken, Erik; Rongen, Peter; van Almsick, Markus; ter Haar Romeny, Bart

2006-01-01

Cardiac catheter ablation is a minimally invasive medical procedure to treat patients with heart rhythm disorders. It is useful to know the positions of the catheters and electrodes during the intervention, e.g. for the automatization of cardiac mapping. Our goal is therefore to develop a robust image analysis method that can detect the catheters in X-ray fluoroscopy images. Our method uses steerable tensor voting in combination with a catheter-specific multi-step extraction algorithm. The evaluation on clinical fluoroscopy images shows that especially the extraction of the catheter tip is successful and that the use of tensor voting accounts for a large increase in performance.

Adaptive lesion formation using dual mode ultrasound array system

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Liu, Dalong; Casper, Andrew; Haritonova, Alyona; Ebbini, Emad S.

2017-03-01

We present the results from an ultrasound-guided focused ultrasound platform designed to perform real-time monitoring and control of lesion formation. Real-time signal processing of echogenicity changes during lesion formation allows for identification of signature events indicative of tissue damage. The detection of these events triggers the cessation or the reduction of the exposure (intensity and/or time) to prevent overexposure. A dual mode ultrasound array (DMUA) is used for forming single- and multiple-focus patterns in a variety of tissues. The DMUA approach allows for inherent registration between the therapeutic and imaging coordinate systems providing instantaneous, spatially-accurate feedback on lesion formation dynamics. The beamformed RF data has been shown to have high sensitivity and specificity to tissue changes during lesion formation, including in vivo. In particular, the beamformed echo data from the DMUA is very sensitive to cavitation activity in response to HIFU in a variety of modes, e.g. boiling cavitation. This form of feedback is characterized by sudden increase in echogenicity that could occur within milliseconds of the application of HIFU (see http://youtu.be/No2wh-ceTLs for an example). The real-time beamforming and signal processing allowing the adaptive control of lesion formation is enabled by a high performance GPU platform (response time within 10 msec). We present results from a series of experiments in bovine cardiac tissue demonstrating the robustness and increased speed of volumetric lesion formation for a range of clinically-relevant exposures. Gross histology demonstrate clearly that adaptive lesion formation results in tissue damage consistent with the size of the focal spot and the raster scan in 3 dimensions. In contrast, uncontrolled volumetric lesions exhibit significant pre-focal buildup due to excessive exposure from multiple full-exposure HIFU shots. Stopping or reducing the HIFU exposure upon the detection of such an

UK Renal Registry 15th annual report: Chapter 8 UK multisite peritoneal dialysis access catheter audit for first PD catheters 2011.

Science.gov (United States)

Briggs, Victoria; Pitcher, David; Braddon, Fiona; Fogarty, Damian; Wilkie, Martin

2013-01-01

The central paradigm of effective peritoneal dialysis (PD) is an appropriate standard of PD catheter function. The aim of the project was to develop an effective national PD access audit which would identify an 'appropriate standard' of PD catheter function. The UK Renal Registry collected centre specific information on various PD access outcome measures including catheter functionality and post-insertion complications. The first PD access audit covering England, Northern Ireland and Wales was conducted during April to June 2012 looking at incident dialysis patients in 2011. Forty three data collection spreadsheets were returned from a total of 65 centres describing 917 PD catheter placements. The median age of PD patients was 61 years and 61.5% were male. The proportion of patients initiated on PD in comparison to HD was lower in socially deprived areas. There was a relationship between the timing of nephrology referral and the likelihood of surgical assessment regarding PD catheter placement. Patients with diabetes did not have higher rates of PD catheter failure or of early peritonitis. A comparative PD catheter audit has the potential to provide valuable information on an important patient related outcome measure and lead to an improvement in patient experience. There was wide variation between centres of PD catheter use for late presenting patients. Overall patients were more likely to get a PD catheter if they had been known to the service for more than 1 year. The percutaneous insertion technique was associated with a higher early (less than 2 week) peritonitis rate and more catheter flow problems. Copyright © 2013 S. Karger AG, Basel.

Systematic review and meta-analysis: reminder systems to reduce catheter-associated urinary tract infections and urinary catheter use in hospitalized patients.

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Meddings, Jennifer; Rogers, Mary A M; Macy, Michelle; Saint, Sanjay

2010-09-01

Prolonged catheterization is the primary risk factor for catheter-associated urinary tract infection (CAUTI). Reminder systems are interventions used to prompt the removal of unnecessary urinary catheters. To summarize the effect of urinary catheter reminder systems on the rate of CAUTI, urinary catheter use, and the need for recatheterization, we performed a systematic review and meta-analysis. Studies were identified in MEDLINE, the Cochrane Library, Biosis, the Web of Science, EMBASE, and CINAHL through August 2008. Only interventional studies that used reminders to physicians or nurses that a urinary catheter was in use or stop orders to prompt catheter removal in hospitalized adults were included. A total of 6679 citations were identified; 118 articles were reviewed, and 14 articles met the selection criteria. The rate of CAUTI (episodes per 1000 catheter-days) was reduced by 52% (P SMD) in the duration of catheterization was -1.11 overall (P = 070), including a statistically significant decrease in studies that used a stop order (SMD, -0.30; P = .001) but not in those that used a reminder (SMD, -1.54; P = .071). Recatheterization rates were similar in control and intervention groups. Urinary catheter reminders and stop orders appear to reduce the rate of CAUTI and should be strongly considered to enhance the safety of hospitalized patients.

Steam-deformed Judkins-left guiding catheter with use of the GuideLiner catheter to deliver stents for anomalous right coronary artery

Directory of Open Access Journals (Sweden)

Toshiki Kuno

2015-10-01

Full Text Available Objective: Percutaneous coronary intervention for anomalous right coronary artery (RCA originating from the left coronary cusp is challenging because of our current inability to coaxially engage the guiding catheter. Methods: We report a case of an 88-year-old woman with non-ST segment elevation myocardial infarction, with an anomalous RCA origin. Using either the Judkins-Left catheter or Amplatz-Left catheter was difficult because of RCA ostium tortuosity. Thus, we used steam to deform the Judkins-Left catheter, but back-up support was insufficient to deliver the stent. Results: We used GuideLiner®, a novel pediatric catheter with rapid exchange/monorail systems, to enhance back-up support. Conclusions: We were able to successfully stent with both the deformed Judkins-Left guiding catheter and GuideLiner® for an anomalous RCA origin.

Cryo-balloon catheter localization in fluoroscopic images

Science.gov (United States)

Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

2013-03-01

Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

Dosimetric equivalence of nonstandard HDR brachytherapy catheter patterns

International Nuclear Information System (INIS)

Cunha, J. A. M.; Hsu, I-C.; Pouliot, J.

2009-01-01

Purpose: To determine whether alternative high dose rate prostate brachytherapy catheter patterns can result in similar or improved dose distributions while providing better access and reducing trauma. Materials and Methods: Standard prostate cancer high dose rate brachytherapy uses a regular grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. This study used CT datasets with 3 mm slice spacing from ten previously treated patients and digitized new catheters following three hypothetical catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a plan must fulfill the RTOG-0321 dose criteria for target dose coverage (V 100 Prostate >90%) and organ-at-risk dose sparing (V 75 Bladder 75 Rectum 125 Urethra <<1 cc). Results: The three nonstandard catheter patterns used 16 nonparallel, straight divergent catheters, with entry points in the perineum. Thirty plans from ten patients with prostate sizes ranging from 26 to 89 cc were optimized. All nonstandard patterns fulfilled the RTOG criteria when the clinical plan did. In some cases, the dose distribution was improved by better sparing the organs-at-risk. Conclusion: Alternative catheter patterns can provide the physician with additional ways to treat patients previously considered unsuited for brachytherapy treatment (pubic arch interference) and facilitate robotic guidance of catheter insertion. In addition, alternative catheter

Catheter ablation of epicardial ventricular tachycardia

Directory of Open Access Journals (Sweden)

Takumi Yamada, MD, PhD

2014-08-01

Full Text Available Ventricular tachycardias (VTs can usually be treated by endocardial catheter ablation. However, some VTs can arise from the epicardial surface, and their substrate can be altered only by epicardial catheter ablation. There are two approaches to epicardial catheter ablation: transvenous and transthoracic. The transvenous approach through the coronary venous system (CVS has been commonly used because it is easily accessible. However, this approach may be limited by the distribution of the CVS and insufficient radiofrequency energy delivery. Transthoracic epicardial catheter ablation has been developed to overcome these limitations of the transvenous approach. It is a useful supplemental or even preferred strategy to eliminate epicardial VTs in the electrophysiology laboratory. This technique has been applied for scar-related VTs secondary to often non-ischemic cardiomyopathy and sometimes ischemic cardiomyopathy, and idiopathic VTs as the epicardial substrates of these VTs have become increasingly recognized. When endocardial ablation and epicardial ablation through the CVS are unsuccessful, transthoracic epicardial ablation should be the next option. Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery or pericarditis. In such cases, a hybrid procedure involving surgical access with a subxiphoid pericardial window and a limited anterior or lateral thoracotomy might be a feasible and safe method of performing an epicardial catheter ablation in the electrophysiology laboratory. Potential complications associated with this technique include bleeding and collateral damage to the coronary arteries and phrenic nerve. Although the risk of these complications is low, electrophysiologists who attempt epicardial catheter ablation should know the complications associated with this technique, how to minimize their

Resting State Default Mode Network Connectivity, Dual Task Performance, Gait Speed, and Postural Sway in Older Adults with Mild Cognitive Impairment.

Science.gov (United States)

Crockett, Rachel A; Hsu, Chun Liang; Best, John R; Liu-Ambrose, Teresa

2017-01-01

Aging is associated with an increased risk of falling. In particular, older adults with mild cognitive impairment (MCI) are more vulnerable to falling compared with their healthy counterparts. Major contributors to this increased falls risk include a decline in dual task performance, gait speed, and postural sway. Recent evidence highlights the potential influence of the default mode network (DMN), the frontoparietal network (FPN), and the supplementary motor area (SMA) on dual task performance, gait speed, and postural sway. The DMN is active during rest and deactivates during task-oriented processes, to maintain attention and stay on task. The FPN and SMA are involved in top-down attentional control, motor planning, and motor execution. The DMN shows less deactivation during task in older adults with MCI. This lack of deactivation is theorized to increase competition for resources between the DMN and task-related brain regions (e.g., the FPN and SMA), increasing distraction from the task and reducing task performance. However, no study has yet investigated the relationship between the between-network connectivity of the DMN with these regions and dual task walking, gait speed or postural sway. We hypothesized that greater functional connectivity both within the DMN and between DMN-FPN and DMN-SMA, will be associated with poorer performance during dual task walking, slower gait speed, and greater postural sway in older adults with MCI. Forty older adults with MCI were measured on a dual task-walking paradigm, gait speed over a 4-m walk, and postural sway using a sway-meter. Greater within-DMN connectivity was significantly correlated with poorer dual task performance. Furthermore, greater inter-network connectivity between the DMN and SMA was significantly correlated with slower gait speed and greater postural sway on the eyes open floor sway task. Thus, greater resting state DMN functional connectivity may be an underlying neural mechanism for reduced dual task

Fast FLAIR MR images of intracranial hemorrhage

International Nuclear Information System (INIS)

Chun, Eun Ju; Choi, Hye Young; Cho, Young A; Kim, Wha Young

1998-01-01

The purpose of this study is to evaluate the signal characteristics of intracranial hemorrhage, as seen on fluid attenuated inversion recovery (FLAIR) MR imaging according to various stages, and to compare FLAIR imaging with spin-echo T1- and T2-weighted MR imaging. We retrospectively evaluated fast FLAIR images along with spin-echo T1- and T2 weighted MR images of 32 lesions in 25 patients (12 males and 14 females, aged 3 - 84 yrs) with intracranial hemorrhagic lesions. For imaging, 1.5 T unit was used, and the nature of the lesions was found to be as follows : intracranial hemorrhage (n=15); tumor (n=9); infarction (n=4); arteriovenous malformation (n=3); and arachnoid cyst with hemorrhage (n=1). On the basis of spin-echo MR imaging, lesions were classified as acute, early subacute, late subacute, early chronic, or late chronic stage. The signal characteristics of intracranial hemorrhage were analysed in accordance with each staging, as seen on MR FLAIR imaging, and compared to the staging seen on spin-echo T1- and T-2 weighted MR imaging. The signal intensity of intracranial hemorrhage, as seen on FLAIR imaging, was not characteristic; it was similar to that of T2WI during the acute and subacute stages, and similiar to that of T1WI during the chronic stage. When used together with spin-echo T1- and T2-weighted MR imaging, however, FLAIR imaging may be useful for the classification of chronic intracranial hemorrhage as either early or late stage. (author). 20 refs., 2 tabs., 6 figs

Intracranial structural alteration predicts treatment outcome in patients with spontaneous intracranial hypotension.

Science.gov (United States)

Choi, Hanna; Lee, Mi Ji; Choi, Hyun Ah; Cha, Jihoon; Chung, Chin-Sang

2018-02-01

Background Intracranial structural dislocation in spontaneous intracranial hypotension (SIH) can be measured by various intracranial angles and distances. We aimed to identify the clinical significance of structural dislocation in relation to treatment outcome in patients with SIH. Methods In this retrospective analysis, we identified patients with SIH who received an epidural blood patch (EBP) at Samsung Medical Center from January 2005 to March 2015. Structural dislocation in pretreatment MRIs of SIH patients was assessed by measuring tonsillar herniation, mamillopontine distance, the angle between the vein of Galen and straight sinus (vG/SS angle), the pontomesencephalic angle, and the lateral ventricular angle. After the first EBP, poor response was defined as the persistence of symptoms that prompted a repeat EBP. Results Out of the 95 patients included, 31 (32.6%) showed poor response. Among the radiological markers of structural dislocation, the vG/SS angle was associated with poor response (49.82 ± 16.40° vs 66.58 ± 26.08°, p = 0.002). Among clinical variables, premorbid migraine ( p = 0.036) was related to poor response. In multivariate analysis, reduced vG/SS angle was independently associated with poor response (OR 1.04 [95% CI 1.01 - 1.07] per 1° decrease, p = 0.006). In 23 patients who underwent MRI after successful treatment, the vG/SS angle significantly increased after the EBP ( p < 0.001, by paired t-test), while two patients with aggravation or recurrence showed a further reduction of their vG/SS angles. Conclusions Intracranial structural dislocation, measured by the vG/SS angle, is associated with poor response to the first EBP in patients with SIH. Successful treatment can reverse the structural dislocation.

Intracranial alveolar echinococcosis: CT and MRI

International Nuclear Information System (INIS)

Bensaid, A.H.; Dietemann, J.L.; Filippi de la Palavesa, M.M.; Klinkert, A.; Kastler, B.; Gangi, A.; Jacquet, G.; Cattin, F.

1994-01-01

Intracranial alveolar echinococcosis is uncommon. We report a patient with right frontal lobe and palpebral lesions secondary to a primary hepatic focus with secondary lesion in the lung. The intracranial and palpebral cystic masses were totally removed and both proved to be alveolar hydatid cysts. An unusual feature in this case is CT and MRI demonstration of dural and bony extension. (orig.)

Intracranial alveolar echinococcosis: CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Bensaid, A.H. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Dietemann, J.L. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Filippi de la Palavesa, M.M. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Klinkert, A. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Kastler, B. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Gangi, A. (Dept. of Radiology B, Univ. Hospital, Strasbourg (France)); Jacquet, G. (Dept. of Neurosurgery, Univ. Hospital, Besancon (France)); Cattin, F. (Dept. of Radiology, Univ. Hospital, Besancon (France))

1994-05-01

Intracranial alveolar echinococcosis is uncommon. We report a patient with right frontal lobe and palpebral lesions secondary to a primary hepatic focus with secondary lesion in the lung. The intracranial and palpebral cystic masses were totally removed and both proved to be alveolar hydatid cysts. An unusual feature in this case is CT and MRI demonstration of dural and bony extension. (orig.)

Catheter Angiography

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Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you're taking and allergies, especially ... is Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical ...

Catheter Angiography

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Full Text Available ... a catheter, x-ray imaging guidance and an injection of contrast material to examine blood vessels in ... technologies and, in most cases, a contrast material injection is needed to produce pictures of blood vessels ...

Catheter Angiography

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Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... angiogram may be performed in less than an hour; however, it may last several hours. top of ...

Catheter Angiography

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Full Text Available ... the American College of Radiology (ACR) and the European Society of Urogenital Radiology note that the available ... will regain their normal function within five to seven days. Rarely, the catheter punctures the artery, causing ...

Catheter Angiography

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Full Text Available ... diagnosis and treatment in a single procedure. An example is finding an area of severe arterial narrowing, ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

Catheter Angiography

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Full Text Available ... possible to combine diagnosis and treatment in a single procedure. Catheter angiography produces very detailed, clear and ... possible to combine diagnosis and treatment in a single procedure. An example is finding an area of ...

Catheter Angiography

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Full Text Available ... far outweighs the risk. If you have a history of allergy to x-ray contrast material, your ... Angiography (CTA) X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored ...

Catheter Angiography

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Full Text Available ... examine blood vessels in key areas of the body for abnormalities such as aneurysms and disease such ... to produce pictures of blood vessels in the body. Angiography is performed using: x-rays with catheters ...

Catheter Angiography

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Full Text Available ... rare, and radiology departments are well-equipped to deal with them. There is a small risk that ... standard x-ray contrast. Catheter angiography should be done very cautiously—if at all—in patients who ...

Catheter Angiography

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Full Text Available ... atherosclerosis (plaque). The use of a catheter makes it possible to combine diagnosis and treatment in a ... the aorta in the chest or abdomen or its major branches. show the extent and severity of ...

Catheter Angiography

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Full Text Available ... 20 minutes (or by using a special closure device). When the examination is complete, you may be ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

Catheter Angiography

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Full Text Available ... rays ). top of page What are some common uses of the procedure? Catheter angiography is used to ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

Catheter Angiography

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Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... and x-rays. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

Catheter Angiography

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Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... possible to combine diagnosis and treatment in a single procedure. An example is finding an area of ...

Catheter Angiography

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Full Text Available ... Once the catheter is guided to the area being examined, a contrast material is injected through the ... You should inform your physician of any medications being taken and if there are any allergies, especially ...

Percutaneous transfemoral repositioning of malpositioned central venous catheters.

Science.gov (United States)

Hartnell, G G; Roizental, M

1995-04-01

Central venous catheters inserted by blind surgical placement may not advance into a satisfactory position and may require repositioning. Malpositioning via surgical insertion is common in patients in whom central venous catheters have previously been placed, as these patients are more likely to have central venous thrombosis and distortion of central venous anatomy. This is less of a problem when catheter placement is guided by imaging; however, even when insertion is satisfactory, central venous catheters may become displaced spontaneously after insertion (Fig. 1). Repositioning can be effected by direct manipulation using guidewires or tip-deflecting wires [1, 2], by manipulation via a transfemoral venous approach [3-5], and by injection of contrast material or saline [6]. Limitations of the direct approach include (1) the number and type of maneuvers that can be performed to effect repositioning when anatomy is distorted, (2) difficulty in accessing the catheter, and (3) the risk of introducing infection. Moreover, these patients are often immunosuppressed, and there is a risk of introducing infection by exposing and directly manipulating the venous catheter. Vigorous injection of contrast material or saline may be unsuccessful for the same reasons: It seldom exerts sufficient force to reposition large-caliber central venous catheters and may cause vessel damage or rupture if injection is made into a small or thrombosed vessel. We illustrate several alternative methods for catheter repositioning via a transfemoral venous approach.

A portable optical emission spectroscopy-cavity ringdown spectroscopy dual-mode plasma spectrometer for measurements of environmentally important trace heavy metals: Initial test with elemental Hg

Science.gov (United States)

Sahay, Peeyush; Scherrer, Susan T.; Wang, Chuji

2012-09-01

A portable optical emission spectroscopy-cavity ringdown spectroscopy (OES-CRDS) dual-mode plasma spectrometer is described. A compact, low-power, atmospheric argon microwave plasma torch (MPT) is utilized as the emission source when the spectrometer is operating in the OES mode. The same MPT serves as the atomization source for ringdown measurements in the CRDS mode. Initial demonstration of the instrument is carried out by observing OES of multiple elements including mercury (Hg) in the OES mode and by measuring absolute concentrations of Hg in the metastable state 6s6p 3P0 in the CRDS mode, in which a palm-size diode laser operating at a single wavelength 405 nm is incorporated in the spectrometer as the light source. In the OES mode, the detection limit for Hg is determined to be 44 parts per 109 (ppb). A strong radiation trapping effect on emission measurements of Hg at 254 nm is observed when the Hg solution concentration is higher than 50 parts per 106 (ppm). The radiation trapping effect suggests that two different transition lines of Hg at 253.65 nm and 365.01 nm be selected for emission measurements in lower (50 ppm), respectively. In the CRDS mode, the detection limit of Hg in the metastable state 6s6p 3P0 is achieved to be 2.24 parts per 1012 (ppt) when the plasma is operating at 150 W with sample gas flow rate of 480 mL min-1; the detection limit corresponds to 50 ppm in Hg sample solution. Advantage of this novel spectrometer has two-fold, it has a large measurement dynamic range, from a few ppt to hundreds ppm and the CRDS mode can serve as calibration for the OES mode as well as high sensitivity measurements. Measurements of seven other elements, As, Cd, Mn, Ni, P, Pb, and Sr, using the OES mode are also carried out with detection limits of 1100, 33, 30, 144, 576, 94, and 2 ppb, respectively. Matrix effect in the presence of other elements on Hg measurements has been found to increase the detection limit to 131 ppb. These elements in lower

A prospective interventional study to examine the effect of a silver alloy and hydrogel-coated catheter on the incidence of catheter-associated urinary tract infection.

Science.gov (United States)

Chung, P Hy; Wong, C Wy; Lai, C Kc; Siu, H K; Tsang, D Nc; Yeung, K Y; Ip, D Km; Tam, P Kh

2017-06-01

Catheter-associated urinary tract infection is a major hospital-acquired infection. This study aimed to analyse the effect of a silver alloy and hydrogel-coated catheter on the occurrence of catheter-associated urinary tract infection. This was a 1-year prospective study conducted at a single centre in Hong Kong. Adult patients with an indwelling urinary catheter for longer than 24 hours were recruited. The incidence of catheter-associated urinary tract infection in patients with a conventional latex Foley catheter without hydrogel was compared with that in patients with a silver alloy and hydrogel-coated catheter. The most recent definition of urinary tract infection was based on the latest surveillance definition of the National Healthcare Safety Network managed by Centers for Disease Control and Prevention. A total of 306 patients were recruited with a similar ratio between males and females. The mean (standard deviation) age was 81.1 (10.5) years. The total numbers of catheter-days were 4352 and 7474 in the silver-coated and conventional groups, respectively. The incidences of catheter-associated urinary tract infection per 1000 catheter-days were 6.4 and 9.4, respectively (P=0.095). There was a 31% reduction in the incidence of catheter-associated urinary tract infection per 1000 catheter-days in the silver-coated group. Escherichia coli was the most commonly involved pathogen (36.7%) of all cases. Subgroup analysis revealed that the protective effect of silver-coated catheter was more pronounced in long-term users as well as female patients with a respective 48% (P=0.027) and 42% (P=0.108) reduction in incidence of catheter-associated urinary tract infection. The mean catheterisation time per person was the longest in patients using a silver-coated catheter (17.0 days) compared with those using a conventional (10.8 days) or both types of catheter (13.6 days) [P=0.01]. Silver alloy and hydrogel-coated catheters appear to be effective in preventing catheter

Removal of non-deflatable retained foley catheter in the bladder by percutaneous puncture of catheter balloon

International Nuclear Information System (INIS)

Yoo, Jae Duk; Kim, Jae Kyu; Park, Jin Gyun; Chung, Hyon De

1988-01-01

Nondeflatable Foley catheter in the bladder is an uncommon event. We recently experienced a patient in whom the urologist were unable to remove a Foley catheter with cystoscope due to public bone fractures. The procedure, which was successfully carried out, consists of puncturing the ballon under fluoroscope.

Simultaneous Intracranial and Spinal Subdural Hematoma: Two Case Reports

Energy Technology Data Exchange (ETDEWEB)

Yoon, Chung Dae; Song, Chang Joon; Lee, Jeong Eun; Choi, Seung Won [Chungnam National University, Daejeon (Korea, Republic of)

2009-02-15

Spinal subdural hematoma is a rare disease. Simultaneous intracranial and spinal subdural hematoma is extremely rare and only 14 such cases have been reported. We report here on two cases of simultaneous intracranial and spinal subdural hematoma that occurred following a fall-down head injury and intracranial surgery, and we discuss the pathogenesis of the disease.

Iatrogenic Bowel Injury at Exchange of Supra-Pubic Catheter

LENUS (Irish Health Repository)

Foran, AT

2018-04-01

Suprapubic catheter insertion and exchange is a common urological procedure, but it is not without risks and complications. While bowel perforation is a recognised complication at suprapubic catheter insertion, it is not commonly reported at suprapubic catheter exchange. We report our experience of recognition, diagnosis and subsequent successful management of the most important complication related to suprapubic catheters.

Analog experiment of transarterial catheter hyperthermic infusion in vitro

International Nuclear Information System (INIS)

Fan Shufeng Li Zheng; Gu Weizhong; Ru Fuming

2006-01-01

Objective: To investigate the factors related to the heating effect by transarterial catheter hyperthermic infusion with the evaluation of the feasibility in controlling the tumor temperature. Methods: Infusing 55-68 degree C liquid at the speed of 10-40 ml/min through 6F, 5F or 3F catheter with different length respectively under the similar clinical condition. The liquid temperature at the terminal exit of the catheter was measured with a digital thermometer. The factors related to the liquid temperature at the exit of the catheter were analyzed by multiple regression analysis. Results: The infusion temperature , rate and the catheter length were the main related factors to the liquid temperature at the exit of the catheter as the condition similar in clinical use. When 60-65 degree C liquid was infused at the rate of 20-40 ml/min through 5F catheter with length of 80 cm, the mean and 95% confident interval of the liquid temperature at the catheter exit were (47.55±0.44) degree C and 44.61-48.49 degree C respectively. Conclusions: The liquid temperature at the exit of infusion catheter can be regulated and controlled through adjusting the liquid perfusion temperature and speed. (authors)

[Neurosurgery in a patient on dual antiplatelet therapy. Case report and the review of the literature].

Science.gov (United States)

Lubnin, A Yu; Karnaukhov, V V; Moshkin, A V; Rylova, A V; Shimansky, V N

A neurosurgical intervention in a patient on dual antiplatelet therapy is a serious challenge for both the neurosurgeon and anesthesiologist.. The article describes a clinical case of a successful urgent neurosurgical intervention (ventriculoperitoneostomy for obstructive hydrocephalus caused by a large meningioma of the posterior surface of the petrous pyramid) in a patient on dual antiplatelet therapy (DAT) due to a recently placed coronary stent.. Given a high risk of coronary stent thrombosis, the surgery was performed in the presence of ongoing DAT. There were no intracranial hemorrhagic complications, but subcutaneous hemorrhagic complications developed. The article discusses the features of managing similar patients whose number is growing.

Ultrafast spectral dynamics of dual-color-soliton intracavity collision in a mode-locked fiber laser

Science.gov (United States)

Wei, Yuan; Li, Bowen; Wei, Xiaoming; Yu, Ying; Wong, Kenneth K. Y.

2018-02-01

The single-shot spectral dynamics of dual-color-soliton collisions inside a mode-locked laser is experimentally and numerically investigated. By using the all-optically dispersive Fourier transform, we spectrally unveil the collision-induced soliton self-reshaping process, which features dynamic spectral fringes over the soliton main lobe, and the rebuilding of Kelly sidebands with wavelength drifting. Meanwhile, the numerical simulations validate the experimental observation and provide additional insights into the physical mechanism of the collision-induced spectral dynamics from the temporal domain perspective. It is verified that the dynamic interference between the soliton and the dispersive waves is responsible for the observed collision-induced spectral evolution. These dynamic phenomena not only demonstrate the role of dispersive waves in the sophisticated soliton interaction inside the laser cavity, but also facilitate a deeper understanding of the soliton's inherent stability.

The bowed catheter sign: a risk for pericardial tamponade

Energy Technology Data Exchange (ETDEWEB)

Towbin, Richard [Phoenix Children' s Hospital, Department of Radiology, Phoenix, AZ (United States)

2008-03-15

The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

The bowed catheter sign: a risk for pericardial tamponade

International Nuclear Information System (INIS)

Towbin, Richard

2008-01-01

The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

Steam-deformed Judkins-left guiding catheter with use of the GuideLiner(®) catheter to deliver stents for anomalous right coronary artery.

Science.gov (United States)

Kuno, Toshiki; Fujisawa, Taishi; Yamazaki, Hiroyuki; Motoda, Hiroyuki; Kodaira, Masaki; Numasawa, Yohei

2015-01-01

Percutaneous coronary intervention for anomalous right coronary artery (RCA) originating from the left coronary cusp is challenging because of our current inability to coaxially engage the guiding catheter. We report a case of an 88-year-old woman with non-ST segment elevation myocardial infarction, with an anomalous RCA origin. Using either the Judkins-Left catheter or Amplatz-Left catheter was difficult because of RCA ostium tortuosity. Thus, we used steam to deform the Judkins-Left catheter, but back-up support was insufficient to deliver the stent. We used GuideLiner®, a novel pediatric catheter with rapid exchange/monorail systems, to enhance back-up support. We were able to successfully stent with both the deformed Judkins-Left guiding catheter and GuideLiner® for an anomalous RCA origin.

Neonatal intracranial hemorrhages (perinatal onset)

International Nuclear Information System (INIS)

Ban, Sadahiko; Ogata, Masahiro; Yamamoto, Toyoshiro; Nakao, Satoshi; Mizue, Hidenari; Kobayashi, Yutaka.

1982-01-01

1. We have reviewed 34 cases of neonatal intracranial hemorrhages (perinatal onset, 23 mature and 11 premature infants) experienced in 10-year period from 1971 to 1980, with special reference to gestational age, birth weight, type of delivery, presence or absence of asphyxia, symptoms and cause of death. 2. Regarding 9 autopsied cases and 7 cases diagnosed by CT-scan, 10 mature infants composed of 3 subarachnoid hemorrhages, 2 intraventricular hemorrhages, 2 subdural hematomas, 2 intracerebral and 1 subependymal hemorrhage; 6 premature infants consisted of 4 subependymal hemorrhages with ventricular rupture and 2 subarachnoid hemorrhages. Most of them presented with respiratory distress, vomiting and convulsive seizures which developed within 5 days after birth. 3. Poor outcome including death amounted 49% of mature and 63% of premature infants. Along with degree of intracranial hematoma, prematurity and pulmonary complication were felt to be important prognostic factors. 4. Introduction of CT-scan led to prompt diagnosis and treatment, thus lowering mortality rate of neonatal intracranial hemorrhages. (author)

[Intracranial plasmocytomas: biology, diagnosis, and treatment].

Science.gov (United States)

Belov, A I; Gol'bin, D A

2006-01-01

Intracranial plasmocytomas are a rare abnormality in a neurosurgeon's practice. The plasmocytomas may originate from the skull bones or soft tissue intracranial structures; they may be solitary or occur as a manifestation of multiple myeloma, this type being typical of most intracranial plasmocytomas. Progression of solitary plasmocytoma to multiple myeloma is observed in a number of cases. Preoperative diagnosis involves computed tomography or magnetic resonance imaging; angiography is desirable. The final diagnosis of plasmocytoma is chiefly based on a morphological study. Special immunohistochemical studies yield very promising results; these are likely to be of high prognostic value. Intracranial plasmocytomas require a differential approach and a meticulous examination since the presence or absence of multiple myeloma radically affects prognosis. There are well-defined predictors; however, it is appropriate that craniobasal plasmocytomas show a worse prognosis than plasmocytomas of the skull vault and more commonly progress to multiple myeloma. Plasmocytomas respond to radiotherapy very well. The gold standard of treatment for plasmocytoma is its total removal and adjuvant radiation therapy; however, there is evidence for good results when it is partially removed and undergoes radiotherapy or after radical surgery without subsequent radiation. The role of chemotherapy has not been defined today.

Computed tomography in intracranial malignant lymphoma

Energy Technology Data Exchange (ETDEWEB)

Naruse, S; Odake, G; Fujimoto, M; Yamaki, T; Mizukawa, N [Kyoto Prefectural Univ. of Medicine (Japan)

1978-09-01

Malignant lymphoma of the central nervous system has been found more and more often in recent years, partly because of the increased use of radiation and such drugs as steroids and antibiotics. However, the definite diagnosis of this disease is difficult until histological verification has been done by operation or autopsy. Since the revolutionary development of computed tomography, however, several reports have been presented, on the computed tomography of malignant lymphoma of the thorax and abdomen. Nevertheless, only a few cases of intracranial malignant lymphoma have been reported. The purpose of this paper, using four patients, is to emphasize the value of computed tomography in the diagnosis of intracranial malignant lymphoma. The characteristic CT findings of intracranial malignant lymphoma may be summarized follows: (1) the tumors are demonstrated to be well-defined, nodular-shaped, and homogenous isodensity - or slightly high-density - lesions in plain scans, and the tumors homogenously increase in density upon contrast enhancement; (2) the disease always has multifocal intracranial lesions, which are shown simultaneously or one after another, and (3) perifocal edema is prominent around the tumors in the cerebral hemisphere.

Animacroxam, a Novel Dual-Mode Compound Targeting Histone Deacetylases and Cytoskeletal Integrity of Testicular Germ Cell Cancer Cells.

Science.gov (United States)

Steinemann, Gustav; Dittmer, Alexandra; Kuzyniak, Weronika; Hoffmann, Björn; Schrader, Mark; Schobert, Rainer; Biersack, Bernhard; Nitzsche, Bianca; Höpfner, Michael

2017-11-01

Novel approaches for the medical treatment of advanced solid tumors, including testicular germ cell tumors (TGCT), are desperately needed. Especially, TGCT patients not responding to cisplatin-based therapy need therapeutic alternatives, as there is no effective medical treatment available for this particular subgroup. Here, we studied the suitability of the novel dual-mode compound animacroxam for TGCT treatment. Animacroxam consists of an HDAC-inhibitory hydroxamate moiety coupled to a 4,5-diarylimidazole with inherent cytoskeleton disrupting potency. Animacroxam revealed pronounced antiproliferative, cell-cycle arresting, and apoptosis-inducing effects in TGCT cell lines with different cisplatin sensitivities. The IC 50 values of animacroxam ranged from 0.22 to 0.42 μmol/L and were not correlated to the cisplatin sensitivity of the tumor cells. No unspecific cytotoxicity of animacroxam was observed in either cisplatin-sensitive or resistant TGCT cells, even at doses as high as 10 μmol/L. Furthermore, animacroxam induced the formation of actin stress fibers in cancer cells, thereby confirming the cytoskeleton-disrupting and antimigratory properties of its imidazole moiety. When compared with the clinically established HDAC inhibitor vorinostat, the novel dual-mode compound animacroxam exhibited superior antitumoral efficacy in vitro Animacroxam also reduced the tumor size of TGCT tumors in vivo , as evidenced by performing xenograft experiments on tumor bearing chorioallantoic membranes of fertilizes chicken eggs (CAM assay). The in vivo experiments also revealed a very good tolerability of the compound, and hence, animacroxam may be a promising candidate for innovative treatment of TGCT in general and the more so for platinum-insensitive or refractory TGCT. Mol Cancer Ther; 16(11); 2364-74. ©2017 AACR . ©2017 American Association for Cancer Research.

Catheter Associated Urinary Tract Infection Prevention bundle

Directory of Open Access Journals (Sweden)

O. Zarkotou

2017-01-01

Full Text Available Catheter-associated urinary tract infections (CAUTI are among the most common healthcare-associated infections, and potentially lead to significant morbidity and mortality. Multifaceted infection control strategies implemented as bundles can prevent nosocomial infections associated with invasive devices such as CAUTIs. The components of the CAUTI bundle proposed herein, include appropriate indications for catheterization and recommendations for the procedures of catheter insertion and catheter maintenance and care. Avoiding unnecessary urinary catheter use is the most effective measure for their prevention. To minimize the risk of CAUTI, urinary catheters should be placed only when a clinical valid indication is documented and they should be removed as soon as possible; alternatives to catheterization should also be considered. Aseptic insertion technique, maintenance of closed drainage system and strict adherence to hand hygiene are essential for preventing CAUTI. The successful implementation of the bundle requires education and training for all healthcare professionals and evaluation of surveillance data.

Increased intracranial pressure

Science.gov (United States)

... the membranes covering the brain and spinal cord) Subdural hematoma (bleeding between the covering of the brain and ... intracranial pressure Patient Instructions Ventriculoperitoneal shunt - discharge Images Subdural hematoma Central nervous system and peripheral nervous system References ...

Central venous catheter insertion problem solving using intravenous catheter: technical communication

Directory of Open Access Journals (Sweden)

Alemohammad M

2013-02-01

Full Text Available Insertion of central venous catheter is an accepted method for hemodynamic monitor-ring, drug and fluid administration, intravenous access, hemodialysis and applying cardiac pace-maker in hospitalized patients. This procedure can be associated with severe complications. The aim of this article is to provide a practical approach to prevent catheter malposition in states that the guide wire will not pass freely.During central venous insertion in internal jugular vein using modified seldinger technique, when after venous insertion, the passage of the guide wire shows difficulties and don’t pass freely, insertion of an intravenous cannula over the wire and re-insertion of the wire can help to prevent malposition of the wire and the catheter. Use of an intravenous cannula over the guide, in situations that the guide wire cannot pass freely among the needle inserted in internal jugular vein, and re-insertion of the guide can probably prevent or reduce the tissue or vascular trauma and the associated complica-tions. This simple maneuver can be helpful in difficult cases especially in cardiac surgery patients who receive high dose heparin and it is necessary to avoid traumatize-tion of carotid artery.

Catheter Angiography

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Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Interventional radiologist performing an angiography exam View ... ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored by Please note ...

Disappearance of Intracranial Extradural Hematomas: Role of Diastatic Cranial Fracture and Intracranial Pressure - An Institutional Experience

Science.gov (United States)

Bhat, Abdul Rashid; Kirmani, Altaf Rehman; Wani, Mohammed Afzal

2018-01-01

Context: The intracranial extradural hematoma (EDH) occupies space and creates a mass effect on the brain but the tenacious-adhesions of dura to the inner table of skull counters this effect. The intracranial pressure also pushes the hematoma back while it is held by dural tensile-force. Aims: The exploitation of a diastatic fracture, overlying an EDH, by the intracranial pressures to decompress a hematoma out of extradural space into subgaleal/subperiosteal space without surgical intervention. Settings and Design: In a period of 15 years, a group of 11 patients among 729 EDHs were managed conservatively. Materials and Methods: The retrospective study of 11 EDH patients was conducted in the Department of Neurosurgery from January 2000 to December 2014 in 15 years. Statistical Analysis Used: The statistical law of variance was used as applicable. Results: Analysis of spontaneous disappearance of intracranial EDH among 11 patients revealed that only 1.5% (11/729) EDHs resolved conservatively. The most cases (63.6%) were children and the youngest being 9 months old. All the patients had a diastatic fracture overlying-EDH and were fully conscious. The cause of head injury in most was the fall from height. The hospital stay ranged from 2 to 4 days. All the patients had a good recovery at the time of discharging. Conclusion: The trial of the conservative or spontaneous disappearance of an EDH through a diastatic fracture into the subgaleal space is similar to burr-hole drainage without surgical intervention but depends upon the neurological status, the intracranial pressure of the patient, and the availability of all the modern neurosurgical gadgets. PMID:29682037

Spontaneous Intracranial Hypotension without Orthostatic Headache

Directory of Open Access Journals (Sweden)

Tülay Kansu

2009-03-01

Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

Syphilis mimicking idiopathic intracranial hypertension

DEFF Research Database (Denmark)

Yri, Hanne; Wegener, Marianne; Jensen, Rigmor

2011-01-01

Idiopathic intracranial hypertension (IIH) is a condition of yet unknown aetiology affecting predominantly obese females of childbearing age. IIH is a diagnosis of exclusion as raised cerebrospinal fluid pressure may occur secondary to numerous other medical conditions. An atypical phenotype...... or an atypical disease course should alert the physician to reevaluate a presumed IIH-diagnosis. The authors report a case of a 32-year-old non-obese male with intracranial hypertension, secondary to a syphilitic central nervous system infection, initially misdiagnosed as being idiopathic. Upon relevant...

Operating modes and practical power flow analysis of bidirectional isolated power interface for distributed power systems

International Nuclear Information System (INIS)

Wen, Huiqing; Su, Bin

2016-01-01

Highlights: • Four operating modes of Dual-Phase-Shift control for Dual Active Bridge converter are presented. • Effects of “minor parameters” such as the deadtime and power device voltage drops are analyzed. • Accurate power flow models with Dual-Phase-Shift control are developed and verified with experimental results. • Optimal operating mode is determined with respect to the efficiency improvement. • Measured efficiency of the Dual Active Bridge converter is improved up to 14%. - Abstract: Due to the intermittent nature of the renewable energy sources including photovoltaic and wind energy, the energy storage systems are essential to stabilize dc bus voltage. Considering the discharge depth of super-capacitors and energy-storage batteries, the bidirectional isolated power interface will operate for a wide range of voltage and power. This study focuses on in-depth analysis of the dual-active-bridge dc–dc converter that is controlled by the dual-phase-shift scheme to improve the conversion efficiency in distributed power system. The power flow of each operating mode with dual-phase-shift control is characterized based on a detailed analysis of the effects of “minor parameters”, including the deadtime and power device voltage drops. The complete output power plane of the dual-active-bridge converter with dual-phase-shift control is obtained and compared with experimental results. The optimal operating mode is determined according to the practical output power range and the power flow characteristics. Experimental evaluation shows the effectiveness of the proposed power flow model with dual-phase-shift control and significant efficiency improvement using the optimal mode of dual-phase-shift compared with the conventional phase shift control.

Intracranial subdural hematoma coexisting with improvement in spontaneous intracranial hypotension after an epidural blood patch

Directory of Open Access Journals (Sweden)

Cheng-Hsi Chang

2012-11-01

Full Text Available A 36-year-old male had spontaneous intracranial hypotension (SIH presenting with refractory headache for 4 months. Multiple epidural blood patches (EBPs yielded relief of symptoms, but the course was complicated, with asymptomatic intracranial subdural hematoma (SDH. Except for SDH, other radiological diagnostic signs of SIH were resolved and the patient’s headaches improved after EBP. Owing to a mass effect and persistent cerebrospinal fluid (CSF leakage, surgical repair of the spinal leakage was performed, but no cranial procedures were carried out. Postoperatively, the SDH completely resolved, but there was still CSF leakage at the level where surgery was performed. The patient has remained free of headache or other events for 3 years. It was reduction rather than elimination of the spinal CSF leak that yielded remission of SIH. In summary, intracranial SDH can be a complication of inadequately treated SIH (i.e. persistent minor CSF leakage. Management of SDH should focus on correction of the underlying SIH rather than craniotomy for hematoma evacuation.

Urethral catheters: can we reduce use?

NARCIS (Netherlands)

Broek, P.J. van den; Wille, J.C.; Benthem, B.H.B. van; Perenboom, R.J.M.; Akker-van Marle, M.E. van den; Nielen, A.M.A.

2011-01-01

Indwelling urinary catheters are the main cause of healthcare-associated urinary tract infections. It can be expected that reduction of the use of urinary catheters will lead to decreased numbers of urinary tract infection. The efficacy of an intervention programme to improve adherence to

Bacterial Biofilms and Catheters: A Key to Understanding Bacterial Strategies in Catheter-Associated Urinary Tract Infection

Directory of Open Access Journals (Sweden)

J Curtis Nickel

1992-01-01

Full Text Available Despite major technological improvements in catheter drainage systems, the indwelling Foley catheter remains the most common cause of nosocomial infection in medical practice. By approaching this common complicated urinary tract infection from the perspective of the biofilm strategy bacteria appear to use to overcome obstacles to produce bacteriuria, one appreciates a new understanding of these infections. An adherent biofilm of bacteria in their secretory products ascends the luminal and external surface of the catheter and drainage system from a contaminated drainage spigot or urethral meatus into the bladder. If the intraluminal route of bacterial ascent is delayed by strict sterile closed drainage or addition of internal modifications to the system, the extraluminal or urethral route assumes greater importance in the development of bacteriuria, but takes significantly longer. Bacterial growth within these thick coherent biofilms confers a large measure of relative resistance to antibiotics even though the individual bacterium remains sensitive, thus accounting for the failure of antibiotic therapy. With disruption of the protective mucous layer of the bladder by mechanical irritation, the bacteria colonizing the catheter can adhere to the bladder’s mucosal surface and cause infection. An appreciation of the role of bacterial biofilms in these infections should suggest future directions for research that may ultimately reduce the risk of catheter-associated infection.

High-temperature superconducting coplanar-waveguide quarter-wavelength resonator with odd- and even-mode resonant frequencies for dual-band bandpass filter

Energy Technology Data Exchange (ETDEWEB)

Satoh, Kei; Takagi, Yuta; Narahashi, Shoichi [Research Laboratories, NTT DOCOMO, INC., 3-6 Hikari-no-oka Yokosuka, Kanagawa 239-8536 Japan (Japan); Nojima, Toshio, E-mail: satokei@nttdocomo.co.j [Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0814 Japan (Japan)

2010-06-01

This paper presents a high-temperature superconducting coplanar-waveguide quarter-wavelength resonator that has two different resonant modes for use in a dual-band bandpass filter (DBPF). An RF filter with multiple passbands such as the DBPF is a basic element that is expected to achieve broadband transmission by using separated frequency bands aggregately and simultaneously in future mobile communication systems. The proposed resonator has a folded center conductor and two open stubs that are aligned close to it. The odd- and even-mode resonant frequencies are configured using the space between the folded center conductor and the open stubs. It is easy to configure the odd- and even-mode coupling coefficients independently because the two resonant modes have different current density distributions. Consequently, a DBPF with two different bandwidths can be easily designed. This paper presents three design examples for a four-pole Chebyshev DBPF with different combinations of fractional bandwidths in order to investigate the validity of the proposed resonator. This paper also presents measured results of the DBPF based on the design examples from the standpoint of experimental investigation. The designed and measured frequency responses confirm that the proposed resonator is effective in achieving DBPFs not only with two of the same bandwidths but also with two different bandwidths.

Spontaneous rotation of the monorail-type guide extension support catheter during advancement of a curved guiding catheter: the potential hazard of twisting with the coronary guidewire.

Science.gov (United States)

Hashimoto, Sho; Takahashi, Akihiko; Yamada, Takeshi; Mizuguchi, Yukio; Taniguchi, Norimasa; Hata, Tetsuya; Nakajima, Shunsuke

2017-11-20

The extension support guiding catheter has been used to perform complex percutaneous coronary intervention to increase back-up support for the guiding catheter or to ensure deep intubation for device delivery. However, because of its monorail design, advancement of the stent into the distal extension tubing segment is sometimes problematic. Although this problem is considered due to simple collision of the stent, operators have observed tangling between a monorail extension catheter and coronary guidewire in some patients. To examine movement of the collar of the extension guide catheter during advancement of the guiding catheter, we set up an in vitro model in which the guiding catheter had two curves. Rotation of the extension guide catheter was examined by both fluoroscopic imaging and movement of the hub of the proximal end of the catheter. During advancement in the first curve, the collar moved toward the outer side of the curve of the guiding catheter as the operator pushed the shaft of the extension guiding catheter, which overrode the guidewire. After crossing the first curve, the collar moved again to the outer side of the second curve (the inner side of the first curve) of the mother catheter, and then, another clockwise rotation was observed in the proximal hub. Consequently, the collar and tubing portion of the extension guide catheter rotated 360° around the coronary guidewire, and the monorail extension catheter and guidewire became tangled. There is a potential risk of unintentional twisting with the guidewire during advancement into the curved guiding catheter because of its monorail design.

Evaluation of virtual monoenergetic imaging algorithms for dual-energy carotid and intracerebral CT angiography: Effects on image quality, artefacts and diagnostic performance for the detection of stenosis.

Science.gov (United States)

Leithner, Doris; Mahmoudi, Scherwin; Wichmann, Julian L; Martin, Simon S; Lenga, Lukas; Albrecht, Moritz H; Booz, Christian; Arendt, Christophe T; Beeres, Martin; D'Angelo, Tommaso; Bodelle, Boris; Vogl, Thomas J; Scholtz, Jan-Erik

2018-02-01

To investigate the impact of traditional (VMI) and noise-optimized virtual monoenergetic imaging (VMI+) algorithms on quantitative and qualitative image quality, and the assessment of stenosis in carotid and intracranial dual-energy CTA (DE-CTA). DE-CTA studies of 40 patients performed on a third-generation 192-slice dual-source CT scanner were included in this retrospective study. 120-kVp image-equivalent linearly-blended, VMI and VMI+ series were reconstructed. Quantitative analysis included evaluation of contrast-to-noise ratios (CNR) of the aorta, common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery. VMI and VMI+ with highest CNR, and linearly-blended series were rated qualitatively. Three radiologists assessed artefacts and suitability for evaluation at shoulder height, carotid bifurcation, siphon, and intracranial using 5-point Likert scales. Detection and grading of stenosis were performed at carotid bifurcation and siphon. Highest CNR values were observed for 40-keV VMI+ compared to 65-keV VMI and linearly-blended images (P evaluation at shoulder and bifurcation height. Suitability was significantly higher in VMI+ and VMI compared to linearly-blended images for intracranial and ICA assessment (P performance. 40-keV VMI+ showed improved quantitative image quality compared to 65-keV VMI and linearly-blended series in supraaortic DE-CTA. VMI and VMI+ provided increased suitability for carotid and intracranial artery evaluation with excellent assessment of stenosis, but did not translate into increased diagnostic performance. Copyright © 2017 Elsevier B.V. All rights reserved.

MRI of intracranial meningeal malignant fibrous histiocytoma

International Nuclear Information System (INIS)

Ogino, A.; Ochi, M.; Hayashi, K.; Hirata, K.; Hayashi, T.; Yasunaga, A.; Shibata, S.

1996-01-01

We describe the CT and MRI findings in a patient with primary intracranial meningeal malignant fibrous histiocytoma (MFH). CT delineated the anatomical relations and MRI aided in tissue characterisation. To our knowledge, this is the first report describing the MRI findings in primary intracranial meningeal MFH. (orig.). With 1 fig

Catheter placement for lysis of spontaneous intracerebral hematomas: does a catheter position in the core of the hematoma allow more effective and faster hematoma lysis?

Science.gov (United States)

Malinova, Vesna; Schlegel, Anna; Rohde, Veit; Mielke, Dorothee

2017-07-01

For the fibrinolytic therapy of intracerebral hematomas (ICH) using recombinant tissue plasminogen activator (rtPA), a catheter position in the core of the hematoma along the largest clot diameter was assumed to be optimal for an effective clot lysis. However, it never had been proven that core position indeed enhances clot lysis if compared with less optimal catheter positions. In this study, the impact of the catheter position on the effectiveness and on the time course of clot lysis was evaluated. We analyzed the catheter position using a relative error calculating the distance perpendicular to the catheter's center in relation to hematoma's diameter and evaluated the relative hematoma volume reduction (RVR). The correlation of the RVR with the catheter position was evaluated. Additionally, we tried to identify patterns of clot lysis with different catheter positions. The patient's outcome at discharge was evaluated using the Glasgow outcome score. A total of 105 patients were included in the study. The mean hematoma volume was 56 ml. The overall RVR was 62.7 %. In 69 patients, a catheter position in the core of the clot was achieved. We found no significant correlation between catheter position and hematoma RVR (linear regression, p = 0.14). Core catheter position leads to more symmetrical hematoma RVR. Faster clot lysis happens in the vicinity of the catheter openings. We found no significant difference in the patient's outcome dependent on the catheter position (linear regression, p = 0.90). The catheter position in the core of the hematoma along its largest diameter does not significantly influence the effectiveness of clot lysis after rtPA application.

Yb3+,Er3+,Eu3+-codoped YVO4 material for bioimaging with dual mode excitation

International Nuclear Information System (INIS)

Thao, Chu Thi Bich; Huy, Bui The; Sharipov, Mirkomil; Kim, Jin-Ik.; Dao, Van-Duong; Moon, Ja-Young; Lee, Yong-Ill

2017-01-01

We propose an efficient bioimaging strategy using Yb 3+ ,Er 3+ ,Eu 3+ -triplet doped YVO 4 nanoparticles which were synthesized with polymer as a template. The obtained particles possess nanoscale, uniform, and flexible excitation. The effect of Eu 3+ ions on the luminescence properties of YVO 4 :Yb 3+ ,Er 3+ ,Eu 3+ was investigated. The upconversion mechanism of the prepared material was also discussed. The structure and optical properties of the prepared material were characterized by using X-ray diffraction (XRD), Fourier-transform IR spectroscopy (FTIR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) upconversion and photoluminescence spectra. The Commission International de I′Eclairage (CIE) chromaticity coordinates was investigated to confirm the performance of color luminescent emission. The prepared YVO 4 :Yb 3+ ,Er 3+ ,Eu 3+ nanoparticles could be easily dispersed in water by surface modification with cysteine (Cys) and glutathione (GSH). The aqueous dispersion of the modified YVO 4 :Yb 3+ ,Er 3+ ,Eu 3+ exhibits bright upconversion and downconversion luminescence and has been applied for bioimaging of HeLa cells. Our developed material with dual excitation offers a promising advance in bioimaging. - Highlights: • Prepared particles possess nanoscale size, uniform, and larger scale. • The material exhibits strong emission under dual mode excitations. • The surface material has been applied for bioimaging of HeLa cell. • Low cytotoxicity, no auto-fluorescence

Types of urethral catheter for reducing symptomatic urinary tract infections in hospitalised adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial).

Science.gov (United States)

Pickard, R; Lam, T; Maclennan, G; Starr, K; Kilonzo, M; McPherson, G; Gillies, K; McDonald, A; Walton, K; Buckley, B; Glazener, C; Boachie, C; Burr, J; Norrie, J; Vale, L; Grant, A; N'dow, J

2012-11-01

Catheter-associated urinary tract infection (CAUTI) is a major preventable cause of harm for patients in hospital and incurs significant costs for health-care providers such as the UK NHS. Many preventative strategies and measures have been introduced to minimise CAUTI risk, including the use of antimicrobial catheters. However, there is considerable uncertainty regarding their usefulness in terms of reducing symptomatic CAUTI, and whether or not they are cost-effective. Do antimicrobial catheters reduce the rate of symptomatic urinary tract infection (UTI) during short-term hospital use and is their use cost-effective for the UK NHS? A pragmatic multicentre UK randomised controlled trial comparing three catheters as they would be used in the UK NHS: antimicrobial-impregnated (nitrofurazone) and antiseptic-coated (silver alloy) catheters with the standard polytetrafluoroethylene (PTFE)-coated catheters. Economic evaluation used a decision model populated with data from the trial. Sensitivity analysis was used to explore uncertainty. Relevant clinical departments in 24 NHS hospitals throughout the UK. Adults requiring temporary urethral catheterisation for a period of between 1 and 14 days as part of their care, predominantly as a result of elective surgery. Eligible participants were randomised 1 : 1 : 1 to one of three types of urethral catheter in order to make the following pragmatic comparisons: nitrofurazone-impregnated silicone catheter compared with standard PTFE-coated latex catheter; and silver alloy-coated hydrogel latex catheter compared with standard PTFE-coated latex catheter. The primary outcome for clinical effectiveness was the incidence of UTI at any time up to 6 weeks post randomisation. This was defined as any symptom reported during catheterisation, up to 3 days or 1 or 2 weeks post catheter removal or 6 weeks post randomisation combined with a prescription of antibiotics, at any of these times, for presumed symptomatic UTI. The primary economic

Catheter Angiography

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Full Text Available ... key areas of the body for abnormalities such as aneurysms and disease such as atherosclerosis (plaque). The use of a catheter makes ... including the: brain neck heart chest abdomen (such as the kidneys and liver) pelvis legs and feet ...

Catheter Angiography

Medline Plus

Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. ...

Design of a search and rescue terminal based on the dual-mode satellite and CDMA network

Science.gov (United States)

Zhao, Junping; Zhang, Xuan; Zheng, Bing; Zhou, Yubin; Song, Hao; Song, Wei; Zhang, Meikui; Liu, Tongze; Zhou, Li

2010-12-01

The current goal is to create a set of portable terminals with GPS/BD2 dual-mode satellite positioning, vital signs monitoring and wireless transmission functions. The terminal depends on an ARM processor to collect and combine data related to vital signs and GPS/BD2 location information, and sends the message to headquarters through the military CDMA network. It integrates multiple functions as a whole. The satellite positioning and wireless transmission capabilities are integrated into the motherboard, and the vital signs sensors used in the form of belts communicate with the board through Bluetooth. It can be adjusted according to the headquarters' instructions. This kind of device is of great practical significance for operations during disaster relief, search and rescue of the wounded in wartime, non-war military operations and other special circumstances.

"Negative symptoms"secondary to intracranial tumor