A trucut biopsy needle for bipolar radiofrequency ablation of needle tract: a proof-of-concept experiment

International Nuclear Information System (INIS)

Bruners, Philipp; Penzkofer, Tobias; Isfort, Peter; Pfeffer, Jochen; Schmitz-Rode, Thomas; Guenther, Rolf W.; Mahnken, Andreas H.

2010-01-01

To develop a trucut biopsy needle featuring two electrodes that allow for bipolar radiofrequency (RF) coagulation of the puncture tract. We modified a 14-G trucut biopsy needle to contain two insulated electrodes and connected the device to an RF generator. Biopsies in ex vivo porcine liver and kidney were performed. The puncture tract was coagulated by using different RF energy settings (5 W, 10 W, 20 W). Tissue specimens were dissected along the puncture tract and the coagulation area was macroscopically evaluated. CT-guided in vivo liver and kidney biopsies were performed in two domestic pigs. Lengths of specimens were measured. Post-biopsy contrast-enhanced CT examinations were performed to rule out biopsy-related bleeding. Animals were euthanised and coagulation areas macroscopically explored. The mean diameters of the coagulated area around the ex vivo biopsy tract were 4.2 ± 1.1 mm (5 W), 6.0 ± 2.0 mm (10 W) and 5.2 ± 0.51 mm (20 W) in liver and 5.0 ± 0.7 mm (5 W), 6.6 ± 0.9 (10 W) and 6.0 ± 2.0 mm (20 W) in kidney. After biopsies CT revealed no bleeding. Mean maximum coagulation diameters were 10.1 ± 4.6 mm (10 W) in liver and 6.0 ± 2.5 mm (10 W) in kidney. Mean length of the specimens was 12.2 ± 4.4 mm in kidney and 11.1 ± 3.6 mm in liver tissue. Bipolar RF biopsy is a promising tool for tract coagulation after percutaneous biopsy. (orig.)

A new catheter design for combined radiofrequency ablation and optoacoustic treatment monitoring using copper-coated light-guides

Science.gov (United States)

Rebling, Johannes; Oyaga Landa, Francisco Javier; Deán-Ben, Xosé Luis; Razansky, Daniel

2018-02-01

Electrosurgery, i.e. the application of radiofrequency current for tissue ablation, is a frequently used treatment for many cardiac arrhythmias. Electrophysiological and anatomic mapping, as well as careful radiofrequency power control typically guide the radiofrequency ablation procedure. Despite its widespread application, accurate monitoring of the lesion formation with sufficient spatio-temporal resolution remains challenging with the existing imaging techniques. We present a novel integrated catheter for simultaneous radiofrequency ablation and optoacoustic monitoring of the lesion formation in real time and 3D. The design combines the delivery of both electric current and optoacoustic excitation beam in a single catheter consisting of copper-coated multimode light-guides and its manufacturing is described in detail. The electrical current causes coagulation and desiccation while the excitation light is locally absorbed, generating OA responses from the entire treated volume. The combined ablation-monitoring capabilities were verified using ex-vivo bovine tissue. The formed ablation lesions showed a homogenous coagulation while the ablation was monitored in realtime with a volumetric frame rate of 10 Hz over 150 seconds.

Liver resection with bipolar radiofrequency device: Habib 4X.

Science.gov (United States)

Pai, Madhava; Jiao, Long R; Khorsandi, Shirin; Canelo, Ruben; Spalding, Duncan R C; Habib, Nagy A

2008-01-01

Intraoperative blood loss has been shown to be an important factor correlating with morbidity and mortality in liver surgery. In spite of the technological advances in hepatic parenchymal transection devices, bleeding remains the single most important complication of liver surgery. The role of radiofrequency (RF) in liver surgery has been expanded from tumour ablation to major hepatic resections in the last decade. Habib 4X, a new bipolar RF device designed specifically for liver resection is described here. Habib 4X is a bipolar, handheld, disposable RF device and consists of two pairs of opposing electrodes which is introduced perpendicularly into the liver, along the intended transection line. It produces controlled RF energy between the electrodes and the heat produced seals even major biliary and blood vessels and enables resection of the liver parenchyma with a scalpel without blood loss or biliary leak. Three hundred and eleven patients underwent 384 liver resections from January 2002 to October 2007 with this device. There were 109 major resections and none of the patients had vascular inflow occlusion (Pringle's manoeuvre). Mean intraoperative blood loss was 305 ml (range 0-4300) ml, with less than 5% (n=18) rate of transfusion. Habib 4X is an additional device for hepatobiliary surgeons to perform liver resections with minimal blood loss and low morbidity and mortality rates.

21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological signal...

Ambient hemolysis and activation of coagulation is different between HeartMate II and HeartWare left ventricular assist devices.

Science.gov (United States)

Birschmann, Ingvild; Dittrich, Marcus; Eller, Thomas; Wiegmann, Bettina; Reininger, Armin J; Budde, Ulrich; Strüber, Martin

2014-01-01

Thromboembolic and bleeding events in patients with a left ventricular assist device (LVAD) are still a major cause of complications. Therefore, the balance between anti-coagulant and pro-coagulant factors needs to be tightly controlled. The principle hypothesis of this study is that different pump designs may have an effect on hemolysis and activation of the coagulation system. Referring to this, the HeartMate II (HMII; Thoratec Corp, Pleasanton, CA) and the HeartWare HVAD (HeartWare International Inc, Framingham, MA) were investigated. For 20 patients with LVAD support (n = 10 each), plasma coagulation, full blood count, and clinical chemistry parameters were measured. Platelet function was monitored using platelet aggregometry, platelet function analyzer-100 system ( Siemens, Marburg, Germany), vasodilator-stimulated phosphoprotein phosphorylation assay, immature platelet fraction, platelet-derived microparticles, and von Willebrand diagnostic. Acquired von Willebrand syndrome could be detected in all patients. Signs of hemolysis, as measured by lactate dehydrogenase levels (mean, 470 U/liter HMII, 250 U/liter HVAD; p < 0.001), were more pronounced in the HMII patients. In contrast, D-dimer analysis indicated a significantly higher activation of the coagulation system in HVAD patients (mean, 0.94 mg/liter HMII, 2.01 mg/liter HVAD; p < 0.01). The efficacy of anti-platelet therapy using clopidogrel was not sufficient in more than 50% of the patients. Our results support the finding that all patients with rotary blood pumps suffered from von Willebrand syndrome. In addition, a distinct footprint of effects on hemolysis and the coagulation system can be attributed to different devices. As a consequence, the individual status of the coagulation system needs to be controlled in long-term patients. © 2013 Published by International Society for the Heart and Lung Transplantation on behalf of International Society for Heart and Lung Transplantation.

What are the benefits and risks of fitting patients with radiofrequency identification devices.

Science.gov (United States)

Levine, Mark; Adida, Ben; Mandl, Kenneth; Kohane, Isaac; Halamka, John

2007-11-27

In 2004, the United States Food and Drug Administration approved a radiofrequency identification (RFID) device that is implanted under the skin of the upper arm of patients and that stores the patient's medical identifier. When a scanner is passed over the device, the identifier is displayed on the screen of an RFID reader. An authorized health professional can then use the identifier to access the patient's clinical information, which is stored in a separate, secure database. Such RFID devices may have many medical benefits--such as expediting identification of patients and retrieval of their medical records. But critics of the technology have raised several concerns, including the risk of the patient's identifying information being used for nonmedical purposes.

Radiofrequency ablation of liver tumors (II): clinical application and outcomes.

Science.gov (United States)

Vanagas, Tomas; Gulbinas, Antanas; Pundzius, Juozas; Barauskas, Giedrius

2010-01-01

Radiofrequency ablation is one of the alternatives in the management of liver tumors, especially in patients who are not candidates for surgery. The aim of this article is to review applicability of radiofrequency ablation achieving complete tumor destruction, utility of imaging techniques for patients' follow-up, indications for local ablative procedures, procedure-associated morbidity and mortality, and long-term results in patients with different tumors. The success of local thermal ablation consists in creating adequate volumes of tissue destruction with adequate "clear margin," depending on improved delivery of radiofrequency energy and modulated tissue biophysiology. Different volumes of coagulation necrosis are achieved applying different types of electrodes, pulsing energy sources, utilizing sophisticated ablation schemes. Some additional methods are used to increase the overall deposition of energy through alterations in tissue electrical conductivity, to improve heat retention within the tissue, and to modulate tolerance of tumor tissue to hyperthermia. Contrast-enhanced computed tomography, magnetic resonance imaging, ultrasound or positron emission tomography are applied to control the effectiveness of radiofrequency ablation. The long-term results of radiofrequency ablation are controversial.

Flexible Gallium Nitride for High-Performance, Strainable Radio-Frequency Devices.

Science.gov (United States)

Glavin, Nicholas R; Chabak, Kelson D; Heller, Eric R; Moore, Elizabeth A; Prusnick, Timothy A; Maruyama, Benji; Walker, Dennis E; Dorsey, Donald L; Paduano, Qing; Snure, Michael

2017-12-01

Flexible gallium nitride (GaN) thin films can enable future strainable and conformal devices for transmission of radio-frequency (RF) signals over large distances for more efficient wireless communication. For the first time, strainable high-frequency RF GaN devices are demonstrated, whose exceptional performance is enabled by epitaxial growth on 2D boron nitride for chemical-free transfer to a soft, flexible substrate. The AlGaN/GaN heterostructures transferred to flexible substrates are uniaxially strained up to 0.85% and reveal near state-of-the-art values for electrical performance, with electron mobility exceeding 2000 cm 2 V -1 s -1 and sheet carrier density above 1.07 × 10 13 cm -2 . The influence of strain on the RF performance of flexible GaN high-electron-mobility transistor (HEMT) devices is evaluated, demonstrating cutoff frequencies and maximum oscillation frequencies greater than 42 and 74 GHz, respectively, at up to 0.43% strain, representing a significant advancement toward conformal, highly integrated electronic materials for RF applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

International Nuclear Information System (INIS)

De Marco, M; Maggi, S

2006-01-01

Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m -1 (E-field 400 V m -1 ). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy

What are the benefits and risks of fitting patients with radiofrequency identification devices.

Directory of Open Access Journals (Sweden)

Mark Levine

2007-11-01

Full Text Available In 2004, the United States Food and Drug Administration approved a radiofrequency identification (RFID device that is implanted under the skin of the upper arm of patients and that stores the patient's medical identifier. When a scanner is passed over the device, the identifier is displayed on the screen of an RFID reader. An authorized health professional can then use the identifier to access the patient's clinical information, which is stored in a separate, secure database. Such RFID devices may have many medical benefits--such as expediting identification of patients and retrieval of their medical records. But critics of the technology have raised several concerns, including the risk of the patient's identifying information being used for nonmedical purposes.

Magnetic Resonance Mediated Radio Frequency Coagulation for Vascular Repair

Science.gov (United States)

Zhao, Ming

Purpose. Magnetic Resonance Mediated Radiofrequency Coagulation employs the RF heating effect of MRI scanning to coagulate biomaterials for repair of vascular defects. Coagulation of a protein biomaterial by MR-induced RF heating is a novel means to effect repair of defects such as aneurysms or arteriovenous malformations. Our novel method is to coagulate a thermosetting material (such as egg white, which can be used for investigating heat coagulation behavior and MR relaxation properties) delivered endovascularly by catheter and coagulated by RF-induced heating of an intracatheter resonant wire antenna in the scanner. Methods. Experiments were performed on a Siemens 1.5 T MRI scanner and a Bruker 14T NMR spectrometer. Egg white was brought to equilibrium at seven temperatures (20, 30, 40, 50, 60, 70 and 37 °C) in sequence. Measurement of the water spin-lattice relaxation time Ti, spin-spin relaxation time T2, spin-lattice relaxation time in the rotating frame T1p, or full width at half maximum of the MT spectrum were performed at each temperature. Relaxation parameters of raw egg white and egg white after coagulation at 70 °C were measured in the scanner at 20 °C to determine optimum inversion time, echo time and offset frequency for good image contrast between coagulated and uncoagulated protein. Finally, coagulation of egg white within a glass aneurysm phantom by RF heating in the scanner was performed to demonstrate the MR coagulation methodology and the ability to achieve image contrast between coagulated and uncoagulated biomaterial. Results. Water T2, T1p and MT gave the most definitive indication of the change from uncoagulated at low temperature to fully coagulated at 60 °C, while water T1 showed only the expected gradual increase with temperature, and no response to coagulation. MT weighted imaging is expected to be the optimum method to establish the coagulation condition of the biomaterial.

Radiofrequency amplifier based on a DC superconducting quantum interference device

International Nuclear Information System (INIS)

Martinis, J.M.; Hilbert, C.; Clarke, J.

1986-01-01

A method is described of amplifying a radiofrequency signal consisting of: disposing a single symmetrically biased dc SQUID and an input coil within a superconducting shield, the dc SQUID having a superconducting ring interrupted by two shunted Josephson junctions, and the input coil being inductively coupled solely to the ring of the single SQUID, establishing a constant magnetic flux threading the SQUID ring, applying the radiofrequency signal to the input coil from outside of the superconducting shield, obtaining an amplified radiofrequency signal solely from across the ring of the single SQUID, transmitting the amplified radiofrequency signal from across the SQUID ring to the outside of the superconducting shield

New-generation radiofrequency technology.

Science.gov (United States)

Krueger, Nils; Sadick, Neil S

2013-01-01

Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation.

The Feasibility of Hepatic Resections Using a Bipolar Radiofrequency Device (Habib®).

Science.gov (United States)

Civil, Osman; Kement, Metin; Okkabaz, Nuri; Haksal, Mustafa; Gezen, Cem; Oncel, Mustafa

2015-08-01

The bipolar radiofrequency device (Habib®) has been recently introduced in order to reduce intraoperative bleeding for a safe hepatic resection as an alternative to the conventional tools. However, indications, perioperative findings, and outcome of the device for hepatic resections remain and deserve to be analyzed. The current study aims to analyze the feasibility of the bipolar radiofrequency device (Habib®) for hepatic resections. Information of the patients that underwent hepatic resection using with the Habib® device between 2007 and 2011 was abstracted. Patient, disease, and operation-related findings and perioperative data were investigated. A total of 71 cases (38 [53.5 %] males, mean age was 56.8 ± 11.9) were analyzed. Metastatic disease (n = 55; 77.5 %) was the leading indication followed by primary liver and biliary malignancies (n = 7; 9.9 %), hemangioma (n = 5; 7 %), hydatid disease (n = 3; 2.8 %), and hepatic gunshot trauma (n = 1; 1.4 %). Metastasectomy was the most commonly performed procedure (n = 31; 56.3 %), but in 24 (77.4 %) cases, it was performed in addition to extended resections. Other procedures in the study patients include segmentectomy in 17, bisegmentectomy in 19, trisegmentectomy in 17, right or left hepatectomy in 8, and extended right/left hepatectomy in 3. The mean (±SD) operation time was 241.7 ± 78.2 min. The median amount of bleeding was 300 cc (range 25-2500), and 23 (32.4 %) cases required perioperative transfusion. The median hospitalization period was 5 days (range 1-47). Lengthened drainage (n = 9, 12.7 %) and intraabdominal abscess (n = 8, 11.23 %) were the most common problems. Hepatic resections using the Habib® device seem to be feasible in cases with primary and metastatic hepatic lesions and benign liver masses and even those with hepatic trauma. It may lessen the amount of intraoperative hemorrhage, although lengthened drainage and intraabdominal abscess

Comparison of Radiofrequency and Electrocautery With Conventional Scalpel Incisions.

Science.gov (United States)

Hasar, Zafer Burak; Ozmeric, Nurdan; Ozdemir, Burcu; Gökmenoğlu, Ceren; Baris, Emre; Altan, Gökçen; Kahraman, Sevil

2016-11-01

The disadvantages of conventional scalpels, including insufficient control of bleeding, prompted us to search for new alternative methods such as electrosurgery and radiosurgery. In this study, the conventional scalpel was compared with radiosurgery and electrosurgery for wound healing with assessment of lateral heat production, inflammation, and instrument performance. Incisions were made in the palatal mucosa of 42 Wistar rats using a scalpel, electrocautery instrument, or radiofrequency instrument. Postoperative hemostasis, tissue coagulation, and tissue sticking were measured, and pain evaluation through weight loss was recorded. Gingival biopsy specimens from the surgical area were obtained at the time of surgery and 2, 4, 7, and 14 days postoperatively and were evaluated immunohistochemically for inducible nitric oxide synthase and heat shock protein 70. Kruskal-Wallis, 1-way analysis of variance, and Mann-Whitney U tests were used for statistical evaluation. The rats in the electrosurgery and radiosurgery groups had aggressively greater weight loss when compared with the scalpel group in the first 7 days. Hemostasis was better in the electrocautery group, tissue coagulation was greater in the radiofrequency group (P < .001), and tissue sticking was lesser in the scalpel group (P < .001) compared with the other groups. Inducible nitric oxide synthase expression and heat shock protein 70 expression were similar in all 3 groups. Electrosurgery performed better regarding hemostasis, whereas a scalpel was superior in terms of tissue sticking and tissue coagulation. Radiosurgery was superior regarding hemostasis when compared with a conventional scalpel, but it was not as successful as electrosurgery. Copyright © 2016. Published by Elsevier Inc.

78 FR 25916 - Authorization of Radiofrequency Equipment

Science.gov (United States)

2013-05-03

...] Authorization of Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Proposed rule... bodies, and measurement procedures used to determine RF equipment compliance. The Commission believes... Commission is responsible for an equipment authorization program for radiofrequency (RF) devices under part 2...

Home-based wrinkle reduction using a novel handheld multisource phase-controlled radiofrequency device.

Science.gov (United States)

Shemer, Avner; Levy, Hanna; Sadick, Neil S; Harth, Yoram; Dorizas, Andrew S

2014-11-01

In the last decade, energy-based aesthetic treatments, using light, radiofrequency (RF), and ultrasound, have gained scientific acceptance as safe and efficacious for non-invasive treatment for aesthetic skin disorders. The phase-controlled multisource radiofrequency technology (3DEEP™), which is based on the simultaneous use of multiple RF generators, was proven to allow significant pigment-independent dermal heating without pain or the need of epidermal cooling. This study was performed in order to evaluate the efficacy and safety of a new handheld device delivering multisource radiofrequency to the skin for wrinkle reduction and skin tightening in the home setting. A total of 69 participants (age 54.3 years ± 8.09; age range 37-72 years) were enrolled in the study after meeting all inclusion/exclusion criteria (100%) and providing informed consent. Participants were provided with the tested device together with a user manual and treatment diary, to perform independent treatments at home for 4 weeks. The tested device, (Newa™, EndyMed Medical, Cesarea, Israel) emits 12 W of 1Mhz, RF energy through six electrodes arranged in a linear fashion. Independent control of RF polarity through each one of the 6 electrodes allows significant reduction of energy flow through the epidermis with increased dermal penetration. Participants were instructed to perform at least 5 treatments a week, for one month. Four follow-up visits were scheduled (once a week) during the period of independent treatments at home, following 4 weeks of home treatments, 1 month follow-up visit (1 month after treatment end) and at 3 months follow-up (3 months following treatment end). Analysis of pre-and post treatment images was conducted by three uninvolved physicians experienced with the Fitzpatrick Wrinkle and Elastosis Scale. Fitzpatrick Wrinkle and Elastosis score of each time point (4 weeks following home use treatments; 1 month follow-up, 3 months follow-up) was compared to baseline

Cutaneous remodeling and photorejuvenation using radiofrequency devices

Directory of Open Access Journals (Sweden)

Elsaie Mohamed

2009-01-01

Full Text Available Radio frequency (RF is electromagnetic radiation in the frequency range of 3-300GHz. The primary effects of RF energy on living tissue are considered to be thermal. The goal of the new devices based on these frequency ranges is to heat specific layers of the skin. The directed use of RF can induce dermal heating and cause collagen degeneration. Wound healing mechanisms promote the remodeling of collagen and wound contraction, which ultimately clinically enhances the appearance of mild to moderate skin laxity. Preliminary studies have reported efficacy in the treatment of laxity that involves the periorbital area and jowls. Because RF energy is not dependent on specific chromophore interaction, epidermal melanin is not at risk of destruction and treatment of all skin types is possible. As such, radiofrequency-based systems have been used successfully for nonablative skin rejuvenation, atrophic scar revision and treatment of unwanted hair, vascular lesions and inflammatory acne. The use of RF is becoming more popular, although a misunderstanding exists regarding the mechanisms and limitations of its actions. This concise review serves as an introduction and guide to many aspects of RF in the non ablative rejuvenation of skin.

21 CFR 864.5400 - Coagulation instrument.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coagulation instrument. 864.5400 Section 864.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices § 864...

Radiofrequency ablation in the liver using two cooled-wet electrodes in the bipolar mode

International Nuclear Information System (INIS)

Han, Joon Koo; Lee, Jeong Min; Kim, Se Hyung; Lee, Jae Young; Park, Hee Sun; Eo, Hong; Choi, Byung Ihn

2005-01-01

The purpose of this study was to demonstrate the efficacy of bipolar radiofrequency ablation (RFA) using cooled-wet electrodes inducing coagulation in ex vivo bovine livers and in in vivo canine livers. In ex vivo experiments, 20 coagulations were created by monopolar (group A), and bipolar RFA (group B) using a 200 W generator (Valleylab) and one or two cooled-wet electrodes. In in vivo experiments, one coagulation was created by bipolar RFA in each of eight dogs via laparotomy. In ex vivo and in vivo experiments, RF was applied to one or two electrodes at 100 W for 10 min. The dimensions of the coagulations were compared in the two groups. In ex vivo experiments, the mean volumes of the coagulations produced in group B (54.0±16.5 cm 3 ) were greater than those produced in group A (33.9±12.7 cm 3 ) (P=0.007). In in vivo experiments, bipolar RFA produced a coagulation of 39.4±15.6 cm 3 without a major complication. The present study showed that a RF electrode system using two cooled-wet electrodes in the bipolar mode created larger coagulation volumes than the monopolar mode, and this system can be used to create large coagulation without major complications. (orig.)

ALINE: A device dedicated to understanding radio-frequency sheaths

Directory of Open Access Journals (Sweden)

S. Devaux

2017-08-01

Full Text Available In fusion devices, radiofrequency (RF antennas are used for heating the plasma. Those antennas and the plasma interact with each other through the so-called RF sheaths, layers of plasma where the quasi-neutrality breaks down and large electric fields arise. Among the effects of RF sheaths, there is the enhancement of the particles and energy fluxes toward the surface of the antenna, which in turn generate hot spots and release impurities, which are both deleterious for plasma operations. RF sheaths comprehension stumbles on the difficulty to achieve in situ measurements of the sheath properties, as scrape-off layer plasmas are a harsh environment. The very goal of the ALINE device is to tackle this issue and to fulfil the blank between numerical simulations and full-scale experiment by providing measurements within the RF sheaths in a controlled environment. In this paper we report on the latest experimental results from ALINE, in which a cylindrical Langmuir probe mounted on a remotely controlled and programmable arm allows for plasma characterizations in the three dimensions of space around the stainless steel antenna, including the sheath. We present a series of density and potential profiles and three dimension (3D maps in the plasma surrounding a stainless-steel RF antenna as well as in the sheath itself, for unmagnetized and magnetized plasmas.

Heat Sink Effect on Tumor Ablation Characteristics as Observed in Monopolar Radiofrequency, Bipolar Radiofrequency, and Microwave, Using Ex Vivo Calf Liver Model

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Pillai, Krishna; Akhter, Javid; Chua, Terence C.; Shehata, Mena; Alzahrani, Nayef; Al-Alem, Issan; Morris, David L.

2015-01-01

Abstract Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices. With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored. With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres. Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected. Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5. MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. PMID:25738477

Experimental animal study of a novel radiofrequency endovascular occlusion device.

Science.gov (United States)

Zacharoulis, Dimitris; Lazoura, Olga; Rountas, Christos; Katsimboulas, Michael; Mantzianas, George; Tzovaras, George; Habib, Nagy

2011-07-01

The purpose of this study was to present a radiofrequency (RF) endovascular occlusion device (ie, Habib VesCoag Catheter; EMcision Ltd, London, UK) and to evaluate safety and efficacy of the device for complete occlusion of normal porcine vessels. The study included 20 pigs. In each pig, a segmental branch of the right hepatic artery, a branch of the splenic artery, and a branch of one of the renal arteries were catheterized. A single or multiple applications of RF energy were performed until vessel occlusion was achieved. Fifteen days later, angiography was repeated to assess vessel patency. The vessels were then excised for pathological analysis. Vessels 2.5 to 6 mm in diameter were treated. Complete occlusion with a single attempt was achieved using a mean amount of energy of 110.67 J in vessels 2.5 to 3 mm, 111.67 J in vessels 3.5 to 4 mm, and 116.63 J in vessels 5 to 6 mm in diameter and was confirmed by angiography at the 15-day follow-up. Vascular occlusion can be effectively and safely achieved by endovascular application of RF energy to normal porcine arteries using the Habib VesCoag catheter. Copyright © 2011 Elsevier Inc. All rights reserved.

77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

Science.gov (United States)

2012-07-25

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 [FCC 12-60] Grantee Codes for Certified Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: This document... authorization program for radiofrequency (RF) devices under part 2 of its rules. This program is one of the...

Radiofrequency for the treatment of skin laxity: mith or truth*

Science.gov (United States)

de Araújo, Angélica Rodrigues; Soares, Viviane Pinheiro Campos; da Silva, Fernanda Souza; Moreira, Tatiane da Silva

2015-01-01

The nonablative radiofrequency is a procedure commonly used for the treatment of skin laxity from an increase in tissue temperature. The goal is to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue. However, many of these devices haven't been tested and their parameters are still not accepted by the scientific community. Because of this, it is necessary to review the literature regarding the physiological effects and parameters for application of radiofrequency and methodological quality and level of evidence of studies. A literature search was performed in MEDLINE, PEDro, SciELO, PubMed, LILACS and CAPES and experimental studies in humans, which used radiofrequency devices as treatment for facial or body laxity, were selected. The results showed that the main physiological effect is to stimulate collagen synthesis. There was no homogeneity between studies in relation to most of the parameters used and the methodological quality of studies and level of evidence for using radiofrequency are low. This fact complicates the determination of effective parameters for clinical use of this device in the treatment of skin laxity. The analyzed studies suggest that radiofrequency is effective, however the physiological mechanisms and the required parameters are not clear in the literature. PMID:26560216

Patient preference and ease of use for different coagulation factor VIII reconstitution device scenarios: a cross-sectional survey in five European countries

Directory of Open Access Journals (Sweden)

Cimino E

2014-12-01

Full Text Available Ernesto Cimino,1 Silvia Linari,2 Mara Malerba,3 Susan Halimeh,4 Francesca Biondo,5 Martina Westfeld5 1Dipartimento Medicina Clinica e Sperimentale, Universita’ degli Studi di Napoli Federico II, Naples, Italy; 2Agenzia per l’ Emofilia, AOU Careggi di Firenze, Florence, Italy; 3Fondazione Cà Granda Ospedale Maggiore Policlinico, Centro Emofilia e Trombosi “A Bianchi Bonomi”, Milan, Italy; 4CRC Coagulation Research Centre GmbH, Duisburg, Germany; 5Pfizer Italia, Rome, Italy Introduction: Hemophilia A treatment involves replacing the deficient coagulation factor VIII. This process may involve multiple steps that might create a barrier to adherence. A new dual-chamber syringe (DCS; FuseNGo® was recently introduced with the aim of simplifying reconstitution. Aim: This study aimed to identify factors associated with adult patients’ preferences for different coagulation factor VIII reconstitution systems and to test ease of use and patient preference for the DCS. Methods: A cross-sectional survey of adults with hemophilia A in five European countries was conducted; a subset of subjects also participated in a practical testing session of the DCS. Results: Among the 299 survey participants, the device scenario requiring the least equipment and reconstitution steps (the DCS received a median preference rating of 71 out of 100 (0 being “the least desirable” and 100 “the most desirable” rating. This was significantly higher than the other scenarios (the next highest achieved a median of 50 points; P<0.001. Participants would be more likely to use this device prophylactically (P<0.001. Among the 98 participants who tested the DCS, 57% preferred this device over their current device, 26% preferred their current device, and 17% had no preference. The DCS was rated as easier to use than current treatment devices (median score 9/10 versus 7/10 for current treatment, P=0.001. Conclusion: The survey indicates that the prefilled DCS, Fuse

A survey on monopolar radiofrequency treatment.

Science.gov (United States)

Suh, Dong Hye; Hong, Eun Sun; Kim, Hyun Joo; Lee, Sang Jun; Kim, Hei Sung

2017-09-01

This questionnaire-based study was aimed to measure the level of appreciation, awareness of the special tips, and practice patterns of monopolar radiofrequency among Korean dermatologists practicing a specific monopolar radiofrequency device (Thermage® Inc., Hayward, CA). A total of 82 surveys were analyzed to show that the majority of participants (78.8%) were highly satisfied with the outcomes of monopolar radiofrequency treatment. All respondents were aware of the Eye Tip 0.25 cm 2 , and the majority knew the difference between the Face tip (blue) and the Total tip (orange). Most (86.3%) agreed to the statement that 900 shots were appropriate for facial tightening in those between the ages of 35 and 65 years. 66.2% of participants reported to have perform monopolar radiofrequency to extra-facial sites within the past year. As for the tips, the Total tip was most popular for all body sties and the Big tip was favored for the abdomen, thighs and buttock. We hope our data allow dermatologists to better utilize monopolar radiofrequency. © 2017 Wiley Periodicals, Inc.

Non-surgical radiofrequency facelift.

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Narins, David J; Narins, Rhoda S

2003-10-01

There has been considerable interest in using non-ablative methods to rejuvenate the skin. The ThermaCool TC (Thermage Inc.) is a radiofrequency (RF) device that has been introduced to induce tightening of the address the problem of skin via a uniform volumetric heating into the deep dermis tightening, resulting in a 'non-surgical facelift'. Radiofrequency produces a uniform volumetric heating into the deep dermis. Twenty treatment areas in 17 patients were treated to evaluate the efficacy and safety of RF treatment to the brow and jowls. The technique was found to produce gradual tightening in most patients, and there were no adverse effects.

Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

Science.gov (United States)

Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

2016-01-01

Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

Circumference reduction and cellulite treatment with a TriPollar radiofrequency device: a pilot study.

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Manuskiatti, W; Wachirakaphan, C; Lektrakul, N; Varothai, S

2009-07-01

A wide variety of treatments for circumference reduction and cellulite are available, but most procedures offer suboptimal clinical effect and/or delayed therapeutic outcome. Objective To determine the safety and efficacy of the TriPollar radiofrequency device for cellulite treatment and circumference reduction. Thirty-nine females with cellulite received eight weekly TriPollar treatments. Treatment areas included the abdomen, thighs, buttocks and arms. Subjects were evaluated using standardized photographs and measurements of body weight, circumference, subcutaneous thickness, and skin elasticity of the treatment sites at baseline, immediately after and 4 weeks after the final treatment. Physicians' evaluation of clinical improvement scores using a quartile grading scale was recorded. Thirty-seven patients (95%) completed the treatment protocol. There was significant circumference reduction of 3.5 and 1.7 cm at the abdomen (P = 0.002) and thigh (P = 0.002) regions, respectively. At 4 weeks after the last treatment, the average circumferential reductions of the abdomen and thighs were sustained. No significant circumferential reductions of the buttocks and arms at the last treatment visit compared to baseline were demonstrated (P = 0.138 and 0.152, respectively). Quartile grading scores correlating to approximately 50% improvement in cellulite appearance were noted. Tripollar radiofrequency provided beneficial effects on the reduction of abdomen and thigh circumference and cellulite appearance.

Rapid, Sensitive, and Reusable Detection of Glucose by a Robust Radiofrequency Integrated Passive Device Biosensor Chip

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Kim, Nam-Young; Adhikari, Kishor Kumar; Dhakal, Rajendra; Chuluunbaatar, Zorigt; Wang, Cong; Kim, Eun-Soo

2015-01-01

Tremendous demands for sensitive and reliable label-free biosensors have stimulated intensive research into developing miniaturized radiofrequency resonators for a wide range of biomedical applications. Here, we report the development of a robust, reusable radiofrequency resonator based integrated passive device biosensor chip fabricated on a gallium arsenide substrate for the detection of glucose in water-glucose solutions and sera. As a result of the highly concentrated electromagnetic energy between the two divisions of an intertwined spiral inductor coupled with an interdigital capacitor, the proposed glucose biosensor chip exhibits linear detection ranges with high sensitivity at center frequency. This biosensor, which has a sensitivity of up to 199 MHz/mgmL−1 and a short response time of less than 2 sec, exhibited an ultralow detection limit of 0.033 μM and a reproducibility of 0.61% relative standard deviation. In addition, the quantities derived from the measured S-parameters, such as the propagation constant (γ), impedance (Z), resistance (R), inductance (L), conductance (G) and capacitance (C), enabled the effective multi-dimensional detection of glucose. PMID:25588958

Radiofrequency ablation for the treatment of gastric antral vascular ectasia

DEFF Research Database (Denmark)

Dray, X.; Repici, A.; Gonzalez, P.

2014-01-01

Background and study aims: The traditional endoscopic treatment for gastric antral vascular ectasia (GAVE) is argon plasma coagulation, but results are not always positive. Radiofrequency ablation (RFA) is a new endoscopic therapy that may be an attractive option for the treatment of GAVE. The aim...... of this study was to assess the efficacy and safety of RFA for the treatment of GAVE. Patients and methods: This was an open-label, retrospective, case series study. The main outcome measures were number of red blood cell (RBC) packs transfused (transfusion requirement) and hemoglobin concentrations (g...

Iron Oxide Nanoparticle-Based Magnetic Ink Development for Fully Printed Tunable Radio-Frequency Devices

KAUST Repository

Vaseem, Mohammad

2018-01-30

The field of printed electronics is still in its infancy and most of the reported work is based on commercially available nanoparticle-based metallic inks. Although fully printed devices that employ dielectric/semiconductor inks have recently been reported, there is a dearth of functional inks that can demonstrate controllable devices. The lack of availability of functional inks is a barrier to the widespread use of fully printed devices. For radio-frequency electronics, magnetic materials have many uses in reconfigurable components but rely on expensive and rigid ferrite materials. A suitable magnetic ink can facilitate the realization of fully printed, magnetically controlled, tunable devices. This report presents the development of an iron oxide nanoparticle-based magnetic ink. First, a tunable inductor is fully printed using iron oxide nanoparticle-based magnetic ink. Furthermore, iron oxide nanoparticles are functionalized with oleic acid to make them compatible with a UV-curable SU8 solution. Functionalized iron oxide nanoparticles are successfully embedded in the SU8 matrix to make a magnetic substrate. The as-fabricated substrate is characterized for its magnetostatic and microwave properties. A frequency tunable printed patch antenna is demonstrated using the magnetic and in-house silver-organo-complex inks. This is a step toward low-cost, fully printed, controllable electronic components.

The efficacy of a combination non-thermal focused ultrasound and radiofrequency device for noninvasive body contouring in Asians.

Science.gov (United States)

Shek, Samantha Y N; Yeung, Chi K; Chan, Johnny C Y; Chan, Henry H L

2016-02-01

Several studies have been published on the first generation non-thermal focused ultrasound with an average improvement of 0-3.95 cm reported. We aim to investigate the efficacy of the second-generation non-thermal focused ultrasound device with a combined radiofrequency hand piece. With the addition of radiofrequency energy, the temperature of the adipose tissue is raised before focused ultrasound is applied. This facilitates the mechanical disruption of fat cells by focused ultrasound. Twenty subjects were recruited and underwent three treatments biweekly. Caliper reading, abdominal circumference, and standardized photographs were taken with the Vectra(®) system at all visits. We aim to have the subjects stand and hold the same position and the photograph taken after exhalation. Caliper and circumference measurements carry uncertainty. It is impossible to eliminate all uncertainties but can be improved by having the same trained physician assistant perform the measurement at the same site and taking an average of three readings. Pain score and satisfaction were recorded by means of the visual analogue scale. The efficacy is defined by a statistically significant improvement in circumferential improvement based on intention-to-treat analysis. Seventeen subjects completed the treatment schedule. Abdominal circumference showed statistically significant improvement at 2 weeks post-second treatment (P = 0.023) and almost all subsequent follow-ups. Caliper readings were statistically significant at 2 weeks post-second treatment (P = 0.013) and almost all follow-ups. The mean pain score reported was 2.3 on the visual analog scale and 6% were unsatisfied with the overall treatments. Six incidents of wheal formation appeared immediately after treatment all of which subsided spontaneously within several hours. The combination non-thermal focused ultrasound and radiofrequency device is effective for improving body contour in Asians. © 2015 Wiley Periodicals, Inc.

Internally gas-cooled radiofrequency applicators as an alternative to conventional radiofrequency and microwave ablation devices: An in vivo comparison

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Rempp, Hansjörg, E-mail: Hansjoerg.rempp@med.uni-tuebingen.de [Eberhard Karls University of Tübingen, Tübingen University Hospital, Department of Diagnostic and Interventional Radiology, Hoppe-Seyler-Straße 3, Tübingen, 72076 (Germany); Voigtländer, Matthias [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Schenk, Martin [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Enderle, Markus D. [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Scharpf, Marcus [Eberhard Karls University of Tuebingen, Insitute of Pathology, Department on General Pathology and Pathological Anatomy, Liebermeisterstraße 8, 72076 Tübingen (Germany); Greiner, Tim O. [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Neugebauer, Alexander [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); and others

2013-08-15

Purpose: To test the efficacy of internally CO{sub 2}-cooled radiofrequency (RF) ablation in vivo and to compare its effectiveness to a standard water-cooled RF probe and to a gas-cooled microwave (MW) device. Method and materials: 49 ablations were performed on 15 pigs under general anesthesia using 15G monopolar CO{sub 2}-cooled RF applicators, 17G monopolar water-cooled RF applicators and 15G internally CO{sub 2}-cooled microwave devices. The power of the MW device was 45 W, the current of the gas-cooled RF device was 1200–1600 mA. At the water-cooled RF probe, maximum power of 200 W was set. Ablation time was 15 min. The short and long axes of the ablation zone were measured. Histological analyses and NADH-staining were performed. The diameters and the ablation volumes were compared using an analysis of variance. Results: No spots of untreated tissue were observed close to the cooled needle track in any of the ablation zones. The largest short axis diameter was 3.4 ± 0.5 cm achieved with the gas-cooled monopolar applicator. With the water-cooled applicators, short axis diameter was significantly smaller, reaching 2.5 ± 0.4 cm. Gas-cooled MW probes achieved 2.9 ± 1.0 cm. The largest ablation volume was 31.5 ± 12 ml (gas-cooled RF), and the smallest was 12.7 ± 4 ml (water-cooled RF). Short/long axis ratio was largest for gas-cooled RF probes with 0.73 ± 0.08 versus 0.64 ± 0.04 for the water-cooled probes and 0.49 ± 0.25 for the microwave applicator. Conclusion: Gas-cooled RF applicators may have a higher potential for effective destruction of liver lesions than comparable water-cooled RF systems, and may be an alternative to standard RF and MW ablation devices.

The safety and efficacy of a combined diode laser and bipolar radiofrequency compared with combined infrared light and bipolar radiofrequency for skin rejuvenation

Directory of Open Access Journals (Sweden)

Yeon Jin Choi

2012-01-01

Full Text Available Background: As the demand for noninvasive procedures for skin rejuvenation is increasing, combined diode laser and radiofrequency and combined infrared and radiofrequency devices have recently emerged. Aim: To compare Polaris WRA TM , a combination device of diode light and RF, and ReFirme ST TM , a combination device of infrared and bipolar RF, in terms of safety and efficacy on skin rejuvenation. Methods: Fourteen Korean volunteers of skin type II-IV, with facial laxity and periorbital rhytids, received three treatments at 3-week intervals with combined diode laser and bipolar radiofrequency (laser fluence 30 J/cm 2 , RF fluence 90 J/cm 3 on the right half of their faces and combined infrared light and bipolar radiofrequency (RF fluence 120 J/cm 3 on the left half of their faces. Clinical photos of front and bilateral sides of the subjects′ faces were taken at baseline and at 6, 9, 12 weeks after the treatment initiation. The investigators′ and the subjects′ global assessments were performed. Results: There is no statistically significant difference in the overall outcome between Polaris WRA TM and Refirme ST TM based on pre- and post-treatment objective measurements. Polaris WRA TM was more effective than Refirme ST TM at reducing wrinkles when therapeutic results of the two appliances were compared based on the patient satisfaction measurements. After the treatment with both instruments, histological increase in the production and rearrangement of collagen fibers at the dermal layer was observed. The density of the collagen fibers was more increased with the Polaris WRA TM -treated facial area than that of Refirme ST TM . Treatment was generally well tolerated, and there was no serious complication. Conclusion: In this study, both the lasers appeared to be safe, and effective methods for treating skin laxity and facial wrinkles. Combined diode laser and radiofrequency was more effective than combined infrared and radiofrequency at

The safety and efficacy of a combined diode laser and bipolar radiofrequency compared with combined infrared light and bipolar radiofrequency for skin rejuvenation.

Science.gov (United States)

Choi, Yeon Jin; Lee, Jung Yeon; Ahn, Ji Young; Kim, Myeung Nam; Park, Mi Youn

2012-01-01

As the demand for noninvasive procedures for skin rejuvenation is increasing, combined diode laser and radiofrequency and combined infrared and radiofrequency devices have recently emerged. To compare Polaris WRA(TM), a combination device of diode light and RF, and ReFirme ST(TM), a combination device of infrared and bipolar RF, in terms of safety and efficacy on skin rejuvenation. Fourteen Korean volunteers of skin type II-IV, with facial laxity and periorbital rhytids, received three treatments at 3-week intervals with combined diode laser and bipolar radiofrequency (laser fluence 30 J/cm2, RF fluence 90 J/cm3) on the right half of their faces and combined infrared light and bipolar radiofrequency (RF fluence 120 J/cm3) on the left half of their faces. Clinical photos of front and bilateral sides of the subjects' faces were taken at baseline and at 6, 9, 12 weeks after the treatment initiation. The investigators' and the subjects' global assessments were performed. There is no statistically significant difference in the overall outcome between Polaris WRA(TM) and Refirme ST(TM) based on pre- and post-treatment objective measurements. Polaris WRA(TM) was more effective than Refirme ST(TM) at reducing wrinkles when therapeutic results of the two appliances were compared based on the patient satisfaction measurements. After the treatment with both instruments, histological increase in the production and rearrangement of collagen fibers at the dermal layer was observed. The density of the collagen fibers was more increased with the Polaris WRA(TM)-treated facial area than that of Refirme ST(TM). Treatment was generally well tolerated, and there was no serious complication. In this study, both the lasers appeared to be safe, and effective methods for treating skin laxity and facial wrinkles. Combined diode laser and radiofrequency was more effective than combined infrared and radiofrequency at reducing wrinkles and pores when the therapeutic results of both the

A novel non-invasive radiofrequency dermal heating device for skin tightening of the face and neck.

Science.gov (United States)

Nelson, Andrew A; Beynet, David; Lask, Gary P

2015-01-01

Loose, lax skin is a common cosmetic complaint. Previous non-invasive skin tightening devices had modest efficacy and were associated with pain or downtime. New technologies may allow for effective skin tightening with a series of radiofrequency (RF) treatments with no downtime. To evaluate the efficacy and safety of a novel bipolar RF device for skin tightening. Fifteen consecutive female patients were enrolled in the case series; 14 completed the study and were included in the analysis. The device under investigation is a novel, bipolar RF device allowing for achievement and maintenance of optimal dermal temperatures to stimulate collagen remodeling and skin tightening. Patients underwent a series of 4-6 weekly treatments. Three blinded, experienced cosmetic physicians evaluated paired pre-treatment and post-treatment photographs and determined the associated improvement, if any. All patients (14/14) were determined to have a clinical improvement, as the pre-treatment and post-treatment photographs were correctly identified by the evaluators. It was observed that 21% (3/14) of patients had significant improvement, 50% (7/14) had moderate improvement, and 29% (4/14) had mild improvement. No pain, side effects, or adverse events were observed. This novel bipolar RF device represents a safe, effective treatment option for non-invasive skin tightening.

Switching bipolar hepatic radiofrequency ablation using internally cooled wet electrodes: comparison with consecutive monopolar and switching monopolar modes

Science.gov (United States)

Yoon, J H; Woo, S; Hwang, E J; Hwang, I; Choi, W; Han, J K; Choi, B I

2015-01-01

Objective: To evaluate whether switching bipolar radiofrequency ablation (SB-RFA) using three internally cooled wet (ICW) electrodes can induce coagulations >5 cm in porcine livers with better efficiency than consecutive monopolar (CM) or switching monopolar (SM) modes. Methods: A total of 60 coagulations were made in 15 in vivo porcine livers using three 17-gauge ICW electrodes and a multichannel radiofrequency (RF) generator. RF energy (approximately 200 W) was applied in CM mode (Group A, n = 20) for 24 min, SM mode for 12 min (Group B, n = 20) or switching bipolar (SB) mode for 12 min (Group C, n = 20) in in vivo porcine livers. Thereafter, the delivered RFA energy, as well as the shape and dimension of coagulations were compared among the groups. Results: Spherical- or oval-shaped ablations were created in 30% (6/20), 85% (17/20) and 90% (18/20) of coagulations in the CM, SM and SB groups, respectively (p = 0.003). SB-RFA created ablations >5 cm in minimum diameter (Dmin) in 65% (13/20) of porcine livers, whereas SM- or CM-RFA created ablations >5 cm in only 25% (5/20) and 20% (4/20) of porcine livers, respectively (p = 0.03). The mean Dmin of coagulations was significantly larger in Group C than in Groups A and B (5.1 ± 0.9, 3.9 ± 1.2 and 4.4 ± 1.0 cm, respectively, p = 0.002) at a lower delivered RF energy level (76.8 ± 14.3, 120.9 ± 24.5 and 114.2 ± 18.3 kJ, respectively, p 5 cm in diameter with better efficiency than do SM- or CM-RFA. Advances in knowledge: SB-RFA can create large, regular ablation zones with better time–energy efficiency than do CM- or SM-RFA. PMID:25873479

A systematic review on radiofrequency assisted laparoscopic liver resection: Challenges and window to excel.

Science.gov (United States)

Reccia, Isabella; Kumar, Jayant; Kusano, Tomokazu; Zanellato, Artur; Draz, Ahmed; Spalding, Duncan; Habib, Nagy; Pai, Madhava

2017-09-01

Laparoscopic liver resection has progressively gained acceptance as a safe and effective procedure in the treatment of benign and malignant liver neoplasms. However, blood loss remains the major challenge in liver surgery. Several techniques and devices have been introduced in liver surgery in order to minimize intraoperative haemorrhage during parenchymal transection. Radiofrequency (RF)-assisted liver resection has been shown to be an effective method to minimize bleeding in open and laparoscopic liver resection. A number of RF devices for parenchymal transection have been designed to assist laparoscopic liver resections. Here we have reviewed the results of various RF devices in laparoscopic liver resection. A total 15 article were considered relevant for the evaluation of technical aspects and outcomes of RF-assisted liver resections in laparoscopic procedures. In these studies, 176 patients had laparoscopic liver resection using RF-assisted parenchymal coagulation. Two monopolar and three bipolar devices were employed. Blood loss was limited in most of the studies. The need of blood transfusions was limited to two cases in all the series. Conversion was necessary due to bleeding in 3 cases. Operative and transection times varied between studies. However, RF-assisted resection with bipolar devices appeared to have taken less time in comparison to other RF devices. RF-related complications were minimum, and only one case of in-hospital death due to hepatic failure was reported. Although RF has been used in a small minority of laparoscopic liver resections, laparoscopic RF-assisted liver resection for benign and malignant disease is a safe and feasible procedure associated with reduction in blood loss, low morbidity, and lower hospital mortality rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Preliminary Study of a Transdermal Radiofrequency Device for Body Slimming.

Science.gov (United States)

Key, Douglas J

2015-11-01

The use and potential of radiofrequency energy for tissue contracture and body contouring has been established in the literature. Maximum reduction of laxity can be achieved by simultaneously tightening surface tissue and reducing unwanted fat below by the transdermal application of heat to reach and maintain tissue temperature targets within a well-defined range, inducing collagen remodeling in skin as well as apoptosis of fat cells and creating an overall slimming effect. A novel device utilizes transcutaneous monopolar RF for body slimming in this manner, employing a thermistor feedback control mechanism to safely manage energy delivery and tissue temperature. Subjects (n=14) presenting with abdominal laxity were treated up to four times using the transcutaneous monopolar RF device at one or two zones in the abdominal region (at operator's discretion). Non-expert blinded graders rated correction on an arbitrary scale (0=no laxity, 4=maximum laxity) after choosing the order of the before-and-after photo sets. A patient satisfaction survey was also administered. The two graders correctly ordered 10 of 14 photo sets in agreement. Average rated improvement was 0.75 and 0.80 for graders 1 and 2, respectively. Patient survey results revealed average perceived tightening of 2.14 points on a 0 to 4 scale (0=lowest tightening result, 4=highest tightening), and 8 of 14 subjects would recommend treatment to others. Transdermal monopolar RF is a safe and effective modality for non-invasive body slimming.

Radiofrequency and microwave tumor ablation in patients with implanted cardiac devices: Is it safe?

Energy Technology Data Exchange (ETDEWEB)

Skonieczki, Brendan D., E-mail: bskonieczki@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Wells, Catherine, E-mail: cwells1@bidmc.harvard.edu [Department of Radiology, Harvard Medical School/Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States); Wasser, Elliot J., E-mail: ewasser@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Dupuy, Damian E., E-mail: ddupuy@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States)

2011-09-15

Purpose: To identify malfunction of implanted cardiac devices during or after thermal ablation of tumors in lung, kidney, liver or bone, using radiofrequency (RF) or microwave (MW) energy. Materials and methods: After providing written consent, 19 patients (15 men and 4 women; mean age 78 years) with pacemakers or pacemaker/defibrillators underwent 22 CT image-guided percutaneous RF or MW ablation of a variety of tumors. Before and after each procedure, cardiac devices were interrogated and reprogrammed by a trained cardiac electrophysiology fellow. Possible pacer malfunctions included abnormalities on electrocardiographic (EKG) monitoring and alterations in device settings. Our institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. Informed consent for participation in this retrospective study was deemed unnecessary by our review board. Results: During 20 of 22 sessions, no abnormalities were identified in continuous, EKG tracings or pacemaker functions. However, in two sessions significant changes, occurred in pacemaker parameters: inhibition of pacing during RF application in one, session and resetting of mode by RF energy in another session. These changes did not, result in hemodynamic instability of either patient. MW ablation was not associated with, any malfunction. In all 22 sessions, pacemakers were undamaged and successfully reset to original parameters. Conclusion: RF or MW ablation of tumors in liver, kidney, bone and lung can be performed safely in patients with permanent intra-cardiac devices, but careful planning between radiology and cardiology is essential to avoid adverse outcomes.

21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

Science.gov (United States)

2010-04-01

... patient identification and health information. 880.6300 Section 880.6300 Food and Drugs FOOD AND DRUG... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device...

Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.

Science.gov (United States)

Wallace, Adam N; Huang, Ambrose J; Vaswani, Devin; Chang, Randy O; Jennings, Jack W

2016-03-01

Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance. The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications. During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days). Palliative percutaneous

Monopolar radiofrequency ablation using a dual-switching system and a separable clustered electrode: Evaluation of the in vivo efficiency

International Nuclear Information System (INIS)

Yoon, Jeong Hee; Lee, Jeong Min; Hwang, Eui Jin; Hwang, In Pyung; Beak, Jee Hyun; Han, Joon Koo; Choi, Byung Ihn

2014-01-01

To determine the in vivo efficiency of monopolar radiofrequency ablation (RFA) using a dual-switching (DS) system and a separable clustered (SC) electrode to create coagulation in swine liver. Thirty-three ablation zones were created in nine pigs using a DS system and an SC electrode in the switching monopolar mode. The pigs were divided into two groups for two experiments: 1) preliminary experiments (n = 3) to identify the optimal inter-electrode distances (IEDs) for dual-switching monopolar (DSM)-RFA, and 2) main experiments (n = 6) to compare the in vivo efficiency of DSM-RFA with that of a single-switching monopolar (SSM)-RFA. RF energy was alternatively applied to one of the three electrodes (SSM-RFA) or concurrently applied to a pair of electrodes (DSM-RFA) for 12 minutes in in vivo porcine livers. The delivered RFA energy and the shapes and dimensions of the coagulation areas were compared between the two groups. No pig died during RFA. The ideal IEDs for creating round or oval coagulation area using the DSM-RFA were 2.0 and 2.5 cm. DSM-RFA allowed more efficient RF energy delivery than SSM-RFA at the given time (23.0 ± 4.0 kcal vs. 16.92 ± 2.0 kcal, respectively; p 0.0005). DSM-RFA created a significantly larger coagulation volume than SSM-RFA (40.4 ± 16.4 cm 3 vs. 20.8 ± 10.7 cm 3 ; p < 0.001). Both groups showed similar circularity of the ablation zones (p = 0.29). Dual-switching monopolar-radiofrequency ablation using an SC electrode is feasible and can create larger ablation zones than SSM-RFA as it allows more RF energy delivery at a given time.

Real-time electrical impedimetric monitoring of blood coagulation process under temperature and hematocrit variations conducted in a microfluidic chip.

Directory of Open Access Journals (Sweden)

Kin Fong Lei

Full Text Available Blood coagulation is an extremely complicated and dynamic physiological process. Monitoring of blood coagulation is essential to predict the risk of hemorrhage and thrombosis during cardiac surgical procedures. In this study, a high throughput microfluidic chip has been developed for the investigation of the blood coagulation process under temperature and hematocrit variations. Electrical impedance of the whole blood was continuously recorded by on-chip electrodes in contact with the blood sample during coagulation. Analysis of the impedance change of the blood was conducted to investigate the characteristics of blood coagulation process and the starting time of blood coagulation was defined. The study of blood coagulation time under temperature and hematocrit variations was shown a good agreement with results in the previous clinical reports. The electrical impedance measurement for the definition of blood coagulation process provides a fast and easy measurement technique. The microfluidic chip was shown to be a sensitive and promising device for monitoring blood coagulation process even in a variety of conditions. It is found valuable for the development of point-of-care coagulation testing devices that utilizes whole blood sample in microliter quantity.

Radiofrequency energy in the arthroscopic treatment of knee chondral lesions: a systematic review.

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Rocco, Papalia; Lorenzo, Diaz Balzani; Guglielmo, Torre; Michele, Paciotti; Nicola, Maffulli; Vincenzo, Denaro

2016-03-01

Cartilage debridement is one of the recommended procedures for the management of chondral defects. Radiofrequency probes allow to debride the cartilage, but may induce subchondral bone necrosis. Medline, Cochrane and Google Scholar were searched to identify studies on arthroscopic debridement of the articular cartilage of the knee using radiofrequency chondroplasty. The methodological quality of the studies was assessed using the Coleman methodology score (CMS). Monopolar and bipolar radiofrequency devices provide significantly better clinical outcomes, especially for patients with high-grade chondral lesions, compared with mechanical shaver only. Despite the original concerns regarding subchondral bone necrosis, low complication rates are reported. Heterogeneity in terms of type of device does not allow sound comparison of the published results. There is lack of evidence on the long-term effects of radiofrequency chondroplasty. Study methodology should be improved: the average Coleman methodology score was 56.2 out of 100. More comparative, well-designed and larger cohort trials are needed to ascertain whether radiofrequency chondroplasty offers long-term benefits over other simpler and more economical alternatives. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Radiofrequency Neurotomy

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... your specific symptoms. What you can expect Before radiofrequency neurotomy Let your doctor know if you take ... tobacco products the day of your procedure. During radiofrequency neurotomy Radiofrequency neurotomy is an outpatient procedure, so ...

Transurethral radiofrequency collagen denaturation for the treatment of women with urinary incontinence.

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Kang, Diana; Han, Julia; Neuberger, Molly M; Moy, M Louis; Wallace, Sheila A; Alonso-Coello, Pablo; Dahm, Philipp

2015-03-18

Transurethral radiofrequency collagen denaturation is a relatively novel, minimally invasive device-based intervention used to treat individuals with urinary incontinence (UI). No systematic review of the evidence supporting its use has been published to date. To evaluate the efficacy of transurethral radiofrequency collagen denaturation, compared with other interventions, in the treatment of women with UI.Review authors sought to compare the following.• Transurethral radiofrequency collagen denaturation versus no treatment/sham treatment.• Transurethral radiofrequency collagen denaturation versus conservative physical treatment.• Transurethral radiofrequency collagen denaturation versus mechanical devices (pessaries for UI).• Transurethral radiofrequency collagen denaturation versus drug treatment.• Transurethral radiofrequency collagen denaturation versus injectable treatment for UI.• Transurethral radiofrequency collagen denaturation versus other surgery for UI. We conducted a systematic search of the Cochrane Incontinence Group Specialised Register (searched 19 December 2014), EMBASE and EMBASE Classic (January 1947 to 2014 Week 50), Google Scholar and three trials registries in December 2014, along with reference checking. We sought to identify unpublished studies by handsearching abstracts of major gynaecology and urology meetings, and by contacting experts in the field and the device manufacturer. Randomised and quasi-randomised trials of transurethral radiofrequency collagen denaturation versus no treatment/sham treatment, conservative physical treatment, mechanical devices, drug treatment, injectable treatment for UI or other surgery for UI in women were eligible. We screened search results and selected eligible studies for inclusion. We assessed risk of bias and analysed dichotomous variables as risk ratios (RRs) with 95% confidence intervals (CIs) and continuous variables as mean differences (MDs) with 95% CIs. We rated the quality of

Long-wave plasma radiofrequency ablation for treatment of xanthelasma palpebrarum.

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Baroni, Adone

2018-03-01

Xanthelasma palpebrarum is the most common type of xanthoma affecting the eyelids. It is characterized by asymptomatic soft yellowish macules, papules, or plaques over the upper and lower eyelids. Many treatments are available for management of xanthelasma palpebrarum, the most commonly used include surgical excision, ablative CO 2 or erbium lasers, nonablative Q-switched Nd:YAG laser, trichloroacetic acid peeling, and radiofrequency ablation. This study aims to evaluate the effectiveness of RF ablation in the treatment of xanthelasma palpebrarum, with D.A.S. Medical portable device (Technolux, Italia), a radiofrequency tool working with long-wave plasma energy and without anesthesia. Twenty patients, 15 female and 5 male, affected by xanthelasma palpebrarum, were enrolled for long-wave plasma radiofrequency ablation treatment. The treatment consisted of 3/4 sessions that were carried out at intervals of 30 days. Treatments were well tolerated by all patients with no adverse effects and optimal aesthetic results. The procedure is very fast and can be performed without anesthesia because of the low and tolerable pain stimulation. Long-wave plasma radiofrequency ablation is an effective option for treatment of xanthelasma palpebrarum and adds an additional tool to the increasing list of medical devices for aesthetic treatments. © 2018 Wiley Periodicals, Inc.

Graphene screen-printed radio-frequency identification devices on flexible substrates

NARCIS (Netherlands)

Arapov, K.; Jaakkola, K.; Ermolov, V.; Bex, G.; Rubingh, E.; Haque, S.; Sandberg, H.; Abbel, R.; de With, G.; Friedrich, H.

2016-01-01

Despite the great promise of printed flexible electronics from 2D crystals, and especially graphene, few scalable applications have been reported so far that can be termed roll-to-roll compatible. Here we combine screen printed graphene with photonic annealing to realize radio-frequency

Preliminary clinical evaluation of a noninvasive device for the measurement of coagulability in the elderly.

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Lerman, Yaffa; Werber, Moshe M; Fine, Ilya; Kemelman, Polina

2011-01-01

The feasibility of the noninvasive assessment of blood 'coagulability' (the tendency to coagulate) has been tested by using a novel device, the Thrombo-Monitor. It monitors, by using the principles of near infra-red (NIR) dynamic light scattering, the tendency of blood to create clots. The Thrombo-Monitor observes the very initial changes of blood viscosity, which occurs due to the temporarily induced stasis of capillary blood of the finger. One hundred and fifteen patients aged >65 years (matched by age and sex) participated in the study. Patients were initially divided into four groups based on the patient's medical therapy. The study groups were: warfarin, enoxaparin, aspirin and/or clopidogrel, and a control group. The medications were given according to the patient's comorbidities (eg, atrial fibrillation [AF], status post pulmonary embolism [S/p PE], status post cerebrovascular accident [S/p CVA]). The Thrombo-Monitor Index (TMI) is a noninvasive index, derived on the basis of laboratory test results of international normalized ratio (INR) and prothrombin time (PT) values. For the group of patients who were treated only with warfarin, TMI was adjusted by using the jackknife statistical approach to create maximum correlation and linearity with INR and PT values that ranged from 1.1 to 5.0. For all warfarin patients (N = 35) the TMI was found to have a good correlation with INR and PT values (R(2) = 0.64, P index is significantly correlated with INR and PT values.

Reconfigurable radio-frequency arbitrary waveforms synthesized in a silicon photonic chip.

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Wang, Jian; Shen, Hao; Fan, Li; Wu, Rui; Niu, Ben; Varghese, Leo T; Xuan, Yi; Leaird, Daniel E; Wang, Xi; Gan, Fuwan; Weiner, Andrew M; Qi, Minghao

2015-01-12

Photonic methods of radio-frequency waveform generation and processing can provide performance advantages and flexibility over electronic methods due to the ultrawide bandwidth offered by the optical carriers. However, bulk optics implementations suffer from the lack of integration and slow reconfiguration speed. Here we propose an architecture of integrated photonic radio-frequency generation and processing and implement it on a silicon chip fabricated in a semiconductor manufacturing foundry. Our device can generate programmable radio-frequency bursts or continuous waveforms with only the light source, electrical drives/controls and detectors being off-chip. It modulates an individual pulse in a radio-frequency burst within 4 ns, achieving a reconfiguration speed three orders of magnitude faster than thermal tuning. The on-chip optical delay elements offer an integrated approach to accurately manipulating individual radio-frequency waveform features without constraints set by the speed and timing jitter of electronics, and should find applications ranging from high-speed wireless to defence electronics.

Radiofrequency-induced thermotherapy of nasopharyngeal angiofibroma and immunohistochemical analysis of vessel proliferation: a case report

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Krstulja, Mira; Kujundžić, Milodar; Halaj, Adelaida; Braut, Tamara; Cvjetković, Niko

2008-01-01

Introduction Nasopharyngeal angiofibroma presents with symptoms of nasal obstruction and epistaxis. The treatment of choice is embolization followed by surgery. Case presentation A 52-year-old man underwent surgery for nasopharyngeal angiofibroma after adjuvant radiofrequency-induced thermotherapy. To the best of the authors' knowledge, this is the first case of angiofibroma with clinical follow-up after thermocoagulation therapy supported by quantitative, double immunohistochemistry. We found this case of angiofibroma to be of interest owing to the presentation of symptoms leading to biopsy, the pathohistological observations obtained with synchronous Ki67/cluster of differentiation 34 and Ki67/smooth muscle actin immunohistochemistry and high pericyte proliferation. Conclusion Coagulation of angiofibroma vessels followed by acquisition of a thick mantle of pericytes in a patient with a nasopharyngeal growth suggests that radiofrequency-induced thermotherapy could be a useful, palliative therapy for bleeding nasopharyngeal angiofibroma, supporting vessel maturation prior to surgical tumor removal. PMID:18706100

Development of corrosion condition sensing and monitoring system using radio-frequency identification devices (RFID) : progress report 2

Energy Technology Data Exchange (ETDEWEB)

Gu, G.P.; Li, J.; Liu, P.; Bibby, D.; Zheng, W.; Lo, J. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

2008-12-15

The development of a corrosion severity monitoring system that used radio-frequency identification device (RIFD) technology was discussed. A corrosion monitoring sensor was integrated with a tag modified to partially block the radio frequency signal. The metallic coating caused a frequency shift of the device's reader antenna in order to allow for the accurate characterization of metal coatings. Communications between the tag and the reader were re-established as the corrosion process gradually deteriorated the coating. The method was tested experimentally with 3 RFID systems using both active and passive tags were assembled. A passive tag was covered in aluminum foil. Results of the experiment showed that the metallic coating interfered with RFID signals. A cold-spray technology was used to coat tags with metal alloys. The surface morphology of the coatings was tested to determine optimum coating parameters. Further studies are being conducted to develop software for the technology. 4 refs., 11 figs.

21 CFR 864.5425 - Multipurpose system for in vitro coagulation studies.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Multipurpose system for in vitro coagulation studies. 864.5425 Section 864.5425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated...

Multipolar radiofrequency ablation using 4–6 applicators simultaneously: A study in the ex vivo bovine liver

International Nuclear Information System (INIS)

Stoffner, Rudolf; Kremser, Christian; Schullian, Peter; Haidu, Marion; Widmann, Gerlig; Bale, Reto J.

2012-01-01

In this study the volume and shape of coagulation zones after multipolar radiofrequency ablation (RFA) with simultaneous use of 4–6 applicators in the ex vivo bovine liver were investigated. The RF-applicators were positioned in 13 different configurations to simulate ablation of large solitary tumors and simultaneous ablation of multiple lesions with 120 kJ of applied energy/session. In total, 110 coagulation zones were induced. Standardized measurements of the volume and shape of the coagulation zones were carried out on magnetic resonance images and statistically analyzed. The coagulation zones induced with solitary applicators and with 2 applicators were imperceptibly small and incomplete, respectively. At 20 mm applicator distance, the total ablated volume was significantly larger if all applicators were arranged in a single group compared to placement in 2 distant applicator groups, each consisting of 3 applicators (p = .001). The mean total coagulated volume ranged from immeasurably small (if 6 solitary applicators were applied simultaneously) to 74.7 cc (if 6 applicators at 30 mm distance between neighboring applicators were combined to a single group). Applicator distance, number and positioning array impacted time and shape. The coagulation zones surrounding groups with 4–6 applicators were regularly shaped, homogeneous and completely fused, and the axial diameters were almost constant. In conclusion, multipolar RFA with 4–6 applicators is feasible. The multipolar simultaneous mode should be applied for large and solitary lesions only, small and multiple tumors should be ablated consecutively in standard multipolar mode with up to 3 applicators

Radiofrequency therapy in back pain and complex regional pain syndrome (CRPS

Directory of Open Access Journals (Sweden)

Norina Bergamin

2011-01-01

Full Text Available Percutaneous radiofrequency procedures are frequently used in the management of chronic pain. Continuous radiofrequency (CRF has been established as a safe and effective treatment for pain originating from facet and sacroiliac joints by way of co-agulation of their nerve supply. Different methods have been proposed to account for the complex nerve supply of the sacroiliac joint. Due to its neurodestructive property, CRF was limited to the treatment of neuropathic pain. When applied to the dorsal root ganglion (DRG for spinal pain or to the sympathetic ganglia in treatment of CRPS, heat related side effects have been reported. With the development of pulsed radiofrequency (PRF, a less destructive alternative to CRF became available, that is more suitable to treat neuropathic pain. PRF was adopted in the treatment of several pain conditions with different success. The results with PRF adjacent to the DRG are promising, whereas for facet and sacroiliac joint pain PRF could not yet be proven equally effective as CRF. As for PRF in CRPS there is almost no evidence available. The potential of PRF seems to lie in those areas where CRF is of limited value. Con-versely, it is questionable if PRF will ever be equally effective in indications, where CRF is already well established. Despite its active use in clinical practice, PRF is not validated yet nor is its mode of action. The literature in both cases is accumulating but further studies are urgently needed.

The Biological Effects of Quadripolar Radiofrequency Sequential Application: A Human Experimental Study

OpenAIRE

Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

2014-01-01

Objective: An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Background data: Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. Methods: The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radio...

Percutaneous radiofrequency ablation of renal tumors: Midterm results in 16 patients

International Nuclear Information System (INIS)

Memarsadeghi, Mazda; Schmook, Theresia; Remzi, Mesut; Weber, Michael; Poetscher, Gerda; Lammer, Johannes; Kettenbach, Joachim

2006-01-01

Purpose: To evaluate the outcome of 16 patients after percutaneous radiofrequency ablation of renal tumors. Materials and methods: Sixteen patients (nine women, seven men; mean age, 61 ± 9 years) with 24 unresectable renal tumors (mean volume, 4.3 ± 4.3 cm 3 ) underwent CT-guided (n = 20) or MR imaging-guided (n = 4) percutaneous radiofrequency ablation using an expandable electrode (Starburst XL TM , RITA Medical Systems, Mountain View, CA) with a 150-W generator. The initial follow-up imaging was performed within 1-30 days after RF ablation, then at 3-6 month intervals using either CT or MRI. Residual tumor volume and coagulation necrosis was assessed, and statistical correlation tests were obtained to determine the strength of the relationship between necrosis volume and number of ablations. Results: Overall, 97 overlapping RF ablations were performed (mean, 3.5 ± 1.5 ablations per tumor) during 24 sessions. Five or more RF ablations per tumor created significant larger necrosis volumes than 1-2 (p .034) or 3-4 ablations (p = .020). A complete ablation was achieved in 20/24 tumors (primary technical success, 83%; mean volume of coagulation necrosis: 10.2 ± 7.2 cm 3 ). Three of four residual tumors were retreated and showed complete necrosis thereafter. Three major complications (one percuatneous urinary fistula and two ureteral strictures) were observed after RF ablation. No further clinically relevant complications were observed and renal function remained stable. During a mean follow-up of 11.2 months (range, 0.2-31.5), 15/16 patients (94%) were alive. Only one patient had evidence of local recurrent tumor. Conclusion: The midterm results of percutaneous RF ablation for renal tumors are promising and show that RF ablation is well-suited to preserve renal function

Radiofrequency-induced thermotherapy of nasopharyngeal angiofibroma and immunohistochemical analysis of vessel proliferation: a case report

Directory of Open Access Journals (Sweden)

Krstulja Mira

2008-08-01

Full Text Available Abstract Introduction Nasopharyngeal angiofibroma presents with symptoms of nasal obstruction and epistaxis. The treatment of choice is embolization followed by surgery. Case presentation A 52-year-old man underwent surgery for nasopharyngeal angiofibroma after adjuvant radiofrequency-induced thermotherapy. To the best of the authors' knowledge, this is the first case of angiofibroma with clinical follow-up after thermocoagulation therapy supported by quantitative, double immunohistochemistry. We found this case of angiofibroma to be of interest owing to the presentation of symptoms leading to biopsy, the pathohistological observations obtained with synchronous Ki67/cluster of differentiation 34 and Ki67/smooth muscle actin immunohistochemistry and high pericyte proliferation. Conclusion Coagulation of angiofibroma vessels followed by acquisition of a thick mantle of pericytes in a patient with a nasopharyngeal growth suggests that radiofrequency-induced thermotherapy could be a useful, palliative therapy for bleeding nasopharyngeal angiofibroma, supporting vessel maturation prior to surgical tumor removal.

Development of corrosion condition sensing and monitoring system using radio-frequency identification devices (RFID)

Energy Technology Data Exchange (ETDEWEB)

Gu, G.P.; Zheng, W. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

2008-05-15

This study discussed the development of a corrosion sensing and monitoring system for military land vehicles. Radio-frequency identification device (RFID) technology uses radio waves to identify individual masses with RFID tags attached. A corrosion-sensing element was integrated with the RFID technology, which incorporated a galvanic corrosion cell designed to trigger RFID tags. Corrosion severity was then related to the galvanic current. The tag recorded the sensor reading and transmitted the data to an RFID reader. The tags consisted of a microchip and an antenna. A software development kit has also been developed to interface RFID data with existing applications. While it is currently not possible to modify the RFID tags to prevent security risks, further research is being conducted to assemble a data-logger system with corrosion probes to measure humidity, electrical resistance, and linear polarization resistance. Studies will also be conducted to assemble an active tag reader system and investigate potential modifications. 4 refs., 1 fig., 1 appendix.

Standard guidelines for electrosurgery with radiofrequency current

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Mutalik Sharad

2009-08-01

Full Text Available Definition: Radiofrequency (RF induces thermal destruction of the targeted tissue by an electrical current at a frequency of 0.5 MHz (RF. As the electrode tip is not heated, there is minimal thermal damage to the surrounding tissues, producing good esthetic results. Therefore, RF ablation is also known as cold ablation or "coblation." Modality: It has three modes of operation: (a Cut, (b cut and coagulate and (c coagulate. Therefore, it can be used for various purposes like incision, ablation, fulguration, shave excision and coagulation. Because of the coagulation facility, hemostasis can be achieved and operation becomes easier and faster. Indications: It is effective in treating various skin conditions like dermatosis papulosa nigra, warts, molluscum contagiosum, colloid milia, acquired junctional, compound and dermal melanocytic nevi, seborrheic keratosis, skin tags, granuloma pyogenicum, verrucous epidermal nevi, xanthelesma, rhinophyma, superficial basal cell carcinoma and telangiectasia. It can also be used for cosmetic indications such as resurfacing, earlobe repair and blepharoplasty. Anesthesia: The procedure is accomplished either under topical anesthesia eutactic mixture of local anesthetics or local injectable anesthesia, under all aseptic precautions. Procedure: While operating, only the tip of the electrode should come in contact with the tissue. Actual contact of the electrode with the tissue should be very brief in order to prevent excessive damage to the deeper tissues. This can be accomplished by moving the electrode quickly. Complications: Complications are uncommon and mainly occur due to an improper technique. The treating physician should be aware of the contraindications of the procedure as listed in these guidelines. Physician qualification: RF surgery may be performed by a dermatologist who has acquired adequate training during post-graduation or through recognized fellowships and workshops dedicated to RF surgery. He

Treatment of facial skin laxity by a new monopolar radiofrequency device

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Uwe Wollina

2011-01-01

Full Text Available Background : Acquired facial skin laxity seems to be a result of the combination of intrinsic and extrinsic processes. For treatment of facial ageing, non-invasive procedures have become popular. Aim : We wanted to investigate the effect of a new 2.2-MHz radiofrequency (RF device on acquired facial skin laxity. Setting : Outpatient clinic associated with an academic teaching hospital. Materials and Methods : We performed an open trial with the RF-ReFacing™ device (Meyer-Haake Medical Innovations, Wehrheim/ Germany in the monopolar mode with a power of 8-12 W, two passes per session and repetition three times after 2 weeks without treatment. Results : A total of 20 Caucasian female patients were included (age range, 34-73 years. The procedure was performed without any analgesia. We did not see any adverse effect. The procedure was scored as most convenient or convenient by all patients. Improvement in skin laxity and fine wrinkles was seen after the second treatment in 19 of the 20 patients and after the third treatment in 100% of the patients. On a scale from 0 to 3, improvement in the lower lid, Crow′s feet and jowl line was scored 2.6±0.7 by the patients; improvement in the overall appearance of the face was scored 2.3±0.5. Blinded assessment of the photographs rated the improvement as good or better in 15 of the 20 patients, moderate in 3 patients, no change in 1 patient. Conclusions : RF-ReFacing™ treatment was effective in improvement in skin laxity. Patients′ satisfaction was high. Although RF-ReFacing™ treatment cannot substitute surgical procedure, it might prolong the time to the first surgical facial lift. The number of patients treated was small, and no quantitative measurements or histopathology was performed. Hence further studies with greater number of patients are necessary.

Over one thousand patients with early stage endometriosis treated with the Helica Thermal Coagulator (HELICA): safety aspects.

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Hill, Nicholas; McQueen, John; Morey, Richard; Hanna, Leila; Chandakas, Stefanos; El-Toukhy, Tarek; Erian, John

2006-07-01

To assess the safety of the Helica Thermal Coagulator in the laparoscopic treatment of early stage endometriosis. Retrospective, observational. The Princess Royal University Hospital, The Sloane and Chelsfield Park Hospitals, Kent, UK. One thousand and sixty patients with early stage endometriosis. All patients were treated laparoscopically with the Helica Thermal Coagulator; a new laparoscopic device that combines electrical energy with helium for the treatment of endometriosis. No major bladder, ureteric or bowel injuries occurred. The only complication was a perforated vagina from the cutting probe during dissection of the cul-de-sac in a patient with a vaginal endometriotic nodule. The Helica Thermal Coagulator is a safe device for the laparoscopic treatment of endometriosis.

Surface Potential and Particle Size Effect on the Rate of Perikinetic Coagulation

International Nuclear Information System (INIS)

Molina-Bolivar, J. A.; Galisteo-Gonzalez, F.; Cabrerizo-Vilchez, M.; Hidalgo-alvarez, R.

1998-01-01

The diffusion-controlled rapid coagulation rate of monodisperse polystyrene particles in aqueous solutions has been measured with a low angle scattering apparatus (nephelometer). We have refined this technique by using a narrow scattering flow cell and a pneumatic addicting-mixing device to introduce the salt solution and the latex sample in the cell. Coagulation rate constants were determined from analysis of the scattered light intensity dependence with time at an angle of 4.5 degree centigrade ± 1 degree centigrade. Experiments were designed to check the effects of particle size, surface potential and counterion valency on rapid coagulation constant. The particle ranged in diameter from 151 nm to 530 nm. The results are compared with the predictions of Smoluchowski's theory. Experiments to obtain the stability diagrams and the critical coagulation concentration of latexes have been performed. (Author) 31 refs

Detection of tissue coagulation by decorrelation of ultrasonic echo signals in cavitation-enhanced high-intensity focused ultrasound treatment.

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Yoshizawa, Shin; Matsuura, Keiko; Takagi, Ryo; Yamamoto, Mariko; Umemura, Shin-Ichiro

2016-01-01

A noninvasive technique to monitor thermal lesion formation is necessary to ensure the accuracy and safety of high-intensity focused ultrasound (HIFU) treatment. The purpose of this study is to ultrasonically detect the tissue change due to thermal coagulation in the HIFU treatment enhanced by cavitation microbubbles. An ultrasound imaging probe transmitted plane waves at a center frequency of 4.5 MHz. Ultrasonic radio-frequency (RF) echo signals during HIFU exposure at a frequency of 1.2 MHz were acquired. Cross-correlation coefficients were calculated between in-phase and quadrature (IQ) data of two B-mode images with an interval time of 50 and 500 ms for the estimation of the region of cavitation and coagulation, respectively. Pathological examination of the coagulated tissue was also performed to compare with the corresponding ultrasonically detected coagulation region. The distribution of minimum hold cross-correlation coefficient between two sets of IQ data with 50-ms intervals was compared with a pulse inversion (PI) image. The regions with low cross-correlation coefficients approximately corresponded to those with high brightness in the PI image. The regions with low cross-correlation coefficients in 500-ms intervals showed a good agreement with those with significant change in histology. The results show that the regions of coagulation and cavitation could be ultrasonically detected as those with low cross-correlation coefficients between RF frames with certain intervals. This method will contribute to improve the safety and accuracy of the HIFU treatment enhanced by cavitation microbubbles.

Investigation of coagulation activity of natural coagulants from seeds of different leguminose species

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Šćiban Marina B.

2005-01-01

Full Text Available The ability of seeds of plants: Phaseolus vulgaris, Robinia pseudoacacia Ceratonia siliqua and Amorpha fruticosa, to act as natural coagulants was tested using synthetic turbid water. This water was prepared by adding kaolin into tap water, just before the test. Active components were extracted from ground seeds with distilled water. The coagulation ability of this extract was assessed by the use of standard jar test measurements in water with various initial turbidity. Investigation of these natural coagulants was confirmed their positive coagulation activity. Of all plants that have been examined, the seed extract from Ceratonia siliqua appeared to be one of the most effective coagulants for water treatment. A dose of 20 mg/l of this coagulant resulted in 100% coagulation activity for clarification of water with 17.5 NTU initial turbidity.

Algorithm optimization for multitined radiofrequency ablation: comparative study in ex vivo and in vivo bovine liver.

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Appelbaum, Liat; Sosna, Jacob; Pearson, Robert; Perez, Sarah; Nissenbaum, Yizhak; Mertyna, Pawel; Libson, Eugene; Goldberg, S Nahum

2010-02-01

To prospectively optimize multistep algorithms for largest available multitined radiofrequency (RF) electrode system in ex vivo and in vivo tissues, to determine best energy parameters to achieve large predictable target sizes of coagulation, and to compare these algorithms with manufacturer's recommended algorithms. Institutional animal care and use committee approval was obtained for the in vivo portion of this study. Ablation (n = 473) was performed in ex vivo bovine liver; final tine extension was 5-7 cm. Variables in stepped-deployment RF algorithm were interrogated and included initial current ramping to 105 degrees C (1 degrees C/0.5-5.0 sec), the number of sequential tine extensions (2-7 cm), and duration of application (4-12 minutes) for final two to three tine extensions. Optimal parameters to achieve 5-7 cm of coagulation were compared with recommended algorithms. Optimal settings for 5- and 6-cm final tine extensions were confirmed in in vivo perfused bovine liver (n = 14). Multivariate analysis of variance and/or paired t tests were used. Mean RF ablation zones of 5.1 cm +/- 0.2 (standard deviation), 6.3 cm +/- 0.4, and 7 cm +/- 0.3 were achieved with 5-, 6-, and 7-cm final tine extensions in a mean of 19.5 min +/- 0.5, 27.9 min +/- 6, and 37.1 min +/- 2.3, respectively, at optimal settings. With these algorithms, size of ablation at 6- and 7-cm tine extension significantly increased from mean of 5.4 cm +/- 0.4 and 6.1 cm +/- 0.6 (manufacturer's algorithms) (P mean diameter in specified time: 5.5 cm +/- 0.4 in 18.5 min +/- 0.5 (5-cm extensions) and 5.7 cm +/- 0.2 in 21.2 min +/- 0.6 (6-cm extensions). Large zones of coagulation of 5-7 cm can be created with optimized RF algorithms that help reduce number of tine extensions compared with manufacturer's recommendations. Such algorithms are likely to facilitate the utility of these devices for RF ablation of focal tumors in clinical practice. (c) RSNA, 2010.

Comparison of coagulation activity tests in vitro for selected biomaterials

NARCIS (Netherlands)

van Oeveren, W; Haan, J; Lagerman, P; Schoen, T

Testing of coagulation induced by external communicating medical devices is an International Standardisation Organization (ISO) requirement for products exposed to human blood. Four categories of tests are indicated by ISO 10993/4: a clotting test (partial thromboplastin time; PTT), thrombin

Visualizing radiofrequency-skin interaction using multiphoton microscopy in vivo.

Science.gov (United States)

Tsai, Tsung-Hua; Lin, Sung-Jan; Lee, Woan-Ruoh; Wang, Chun-Chin; Hsu, Chih-Ting; Chu, Thomas; Dong, Chen-Yuan

2012-02-01

Redundant skin laxity is a major feature of aging. Recently, radiofrequency has been introduced for nonablative tissue tightening by volumetric heating of the deep dermis. Despite the wide range of application based on this therapy, the effect of this technique on tissue and the subsequent tissue remodeling have not been investigated in detail. Our objective is to evaluate the potential of non-linear optics, including multiphoton autofluorescence and second harmonic generation (SHG) microscopy, as a non-invasive imaging modality for the real-time study of radiofrequency-tissue interaction. Electro-optical synergy device (ELOS) was used as the radiofrequency source in this study. The back skin of nude mouse was irradiated with radiofrequency at different passes. We evaluated the effect on skin immediately and 1 month after treatment with multiphoton microscopy. Corresponding histology was performed for comparison. We found that SHG is negatively correlated to radiofrequency passes, which means that collagen structural disruption happens immediately after thermal damage. After 1 month of collagen remodeling, SHG signals increased above baseline, indicating that collagen regeneration has occurred. Our findings may explain mechanism of nonablative skin tightening and were supported by histological examinations. Our work showed that monitoring the dermal heating status of RF and following up the detailed process of tissue reaction can be imaged and quantified with multiphoton microscopy non-invasively in vivo. Copyright © 2011. Published by Elsevier Ireland Ltd.

One-year results of the use of endovenous radiofrequency ablation utilising an optimised radiofrequency-induced thermotherapy protocol for the treatment of truncal superficial venous reflux.

Science.gov (United States)

Badham, George E; Dos Santos, Scott J; Lloyd, Lucinda Ba; Holdstock, Judy M; Whiteley, Mark S

2018-06-01

Background In previous in vitro and ex vivo studies, we have shown increased thermal spread can be achieved with radiofrequency-induced thermotherapy when using a low power and slower, discontinuous pullback. We aimed to determine the clinical success rate of radiofrequency-induced thermotherapy using this optimised protocol for the treatment of superficial venous reflux in truncal veins. Methods Sixty-three patients were treated with radiofrequency-induced thermotherapy using the optimised protocol and were followed up after one year (mean 16.3 months). Thirty-five patients returned for audit, giving a response rate of 56%. Duplex ultrasonography was employed to check for truncal reflux and compared to initial scans. Results In the 35 patients studied, there were 48 legs, with 64 truncal veins treated by radiofrequency-induced thermotherapy (34 great saphenous, 15 small saphenous and 15 anterior accessory saphenous veins). One year post-treatment, complete closure of all previously refluxing truncal veins was demonstrated on ultrasound, giving a success rate of 100%. Conclusions Using a previously reported optimised, low power/slow pullback radiofrequency-induced thermotherapy protocol, we have shown it is possible to achieve a 100% ablation at one year. This compares favourably with results reported at one year post-procedure using the high power/fast pullback protocols that are currently recommended for this device.

Implanting inequality: empirical evidence of social and ethical risks of implantable radio-frequency identification (RFID) devices.

Science.gov (United States)

Monahan, Torin; Fisher, Jill A

2010-10-01

The aim of this study was to assess empirically the social and ethical risks associated with implantable radio-frequency identification (RFID) devices. Qualitative research included observational studies in twenty-three U.S. hospitals that have implemented new patient identification systems and eighty semi-structured interviews about the social and ethical implications of new patient identification systems, including RFID implants. The study identified three primary social and ethical risks associated with RFID implants: (i) unfair prioritization of patients based on their participation in the system, (ii) diminished trust of patients by care providers, and (iii) endangerment of patients who misunderstand the capabilities of the systems. RFID implants may aggravate inequalities in access to care without any clear health benefits. This research underscores the importance of critically evaluating new healthcare technologies from the perspective of both normative ethics and empirical ethics.

The quest for durable lesions in catheter ablation of atrial fibrillation - technological advances in radiofrequency catheters and balloon devices.

Science.gov (United States)

Maurer, Tilman; Kuck, Karl-Heinz

2017-08-01

Atrial fibrillation is the most common cardiac arrhythmia and represents a growing clinical, social and economic challenge. Catheter ablation for symptomatic atrial fibrillation has evolved from an experimental procedure into a widespread therapy and offers a safe and effective treatment option. A prerequisite for durable PVI are transmural and contiguous circumferential lesions around the pulmonary veins. However, electrical reconnection of initially isolated pulmonary veins remains a primary concern and is a dominant factor for arrhythmia recurrence during long-term follow up. Areas covered: This article discusses the physiology of lesion formation using radiofrequency-, cryo- or laser- energy for pulmonary vein isolation and provides a detailed review of recent technological advancements in the field of radiofrequency catheters and balloon devices. Finally, future directions and upcoming developments for the interventional treatment of atrial fibrillation are discussed. Expert commentary: Durable conduction block across deployed myocardial lesions is mandatory not only for PVI but for any other cardiac ablation strategy as well. A major improvement urgently expected is the intraprocedural real-time distinction of durable lesions from interposed gaps with only transiently impaired electrical conduction. Furthermore, a simplification of ablation tools used for PVI is required to reduce the high technical complexity of the procedure.

Treatment of Décolletage Photoaging With Fractional Microneedling Radiofrequency.

Science.gov (United States)

Lyons, Alexis; Roy, Jillian; Herrmann, Jennifer; Chipps, Lisa

2018-01-01

The objective of this study was to examine the efficacy and safety of a novel fractional microneedling radiofrequency device to improve the appearance of rhytides and skin laxity of the décolletage. Twelve subjects received a total of three fractional microneedling radiofrequency treatments with Endymed Intensif (EndyMed Ltd., Cesarea, Israel) at least three weeks apart. Primary outcome measure was clinical efficacy quantified by a patient survey to assess treatment satisfaction as well as a physician Global Aesthetic Improvement Scale (GAIS). Photos were taken before every treatment and at a follow-up appointment. Assessments by two board-certified dermatologists revealed an overall improvement in 67% of patients. Seventy percent of subjects rated their post-treatment skin laxity and rhytides as improved, while 60% of patients rated their skin texture as improved. Eighty percent of subjects were at least slightly satisfied with their treatment. Forty percent of subjects would recommend this treatment to others. Subjects in this study demonstrated an overall improvement in décolletage appearance in regard to skin tightening, wrinkles, and skin texture suggested by overall patient satisfaction (80%) and physician-rated GAIS improvement (67%). This study suggests that fractional microneedling radiofrequency devices are a safe and efficacious way to improve overall décolletage appearance with little down time. J Drugs Dermatol. 2018;17(1):74-76..

Overview of the coagulation system.

Science.gov (United States)

Palta, Sanjeev; Saroa, Richa; Palta, Anshu

2014-09-01

Coagulation is a dynamic process and the understanding of the blood coagulation system has evolved over the recent years in anaesthetic practice. Although the traditional classification of the coagulation system into extrinsic and intrinsic pathway is still valid, the newer insights into coagulation provide more authentic description of the same. Normal coagulation pathway represents a balance between the pro coagulant pathway that is responsible for clot formation and the mechanisms that inhibit the same beyond the injury site. Imbalance of the coagulation system may occur in the perioperative period or during critical illness, which may be secondary to numerous factors leading to a tendency of either thrombosis or bleeding. A systematic search of literature on PubMed with MeSH terms 'coagulation system, haemostasis and anaesthesia revealed twenty eight related clinical trials and review articles in last 10 years. Since the balance of the coagulation system may tilt towards bleeding and thrombosis in many situations, it is mandatory for the clinicians to understand physiologic basis of haemostasis in order to diagnose and manage the abnormalities of the coagulation process and to interpret the diagnostic tests done for the same.

Overview of the coagulation system

Directory of Open Access Journals (Sweden)

Sanjeev Palta

2014-01-01

Full Text Available Coagulation is a dynamic process and the understanding of the blood coagulation system has evolved over the recent years in anaesthetic practice. Although the traditional classification of the coagulation system into extrinsic and intrinsic pathway is still valid, the newer insights into coagulation provide more authentic description of the same. Normal coagulation pathway represents a balance between the pro coagulant pathway that is responsible for clot formation and the mechanisms that inhibit the same beyond the injury site. Imbalance of the coagulation system may occur in the perioperative period or during critical illness, which may be secondary to numerous factors leading to a tendency of either thrombosis or bleeding. A systematic search of literature on PubMed with MeSH terms ′coagulation system, haemostasis and anaesthesia revealed twenty eight related clinical trials and review articles in last 10 years. Since the balance of the coagulation system may tilt towards bleeding and thrombosis in many situations, it is mandatory for the clinicians to understand physiologic basis of haemostasis in order to diagnose and manage the abnormalities of the coagulation process and to interpret the diagnostic tests done for the same.

Percutaneous radiofrequency ablation of lung tumors in a large animal model.

Science.gov (United States)

Ahrar, Kamran; Price, Roger E; Wallace, Michael J; Madoff, David C; Gupta, Sanjay; Morello, Frank A; Wright, Kenneth C

2003-08-01

Percutaneous radiofrequency ablation (RFA) is accepted therapy for liver tumors in the appropriate clinical setting, but its use in lung neoplasms remains investigational. We undertook this study to evaluate the feasibility and immediate effectiveness of RFA for treatment of both solitary pulmonary nodules and clusters of lung tumors in a large animal model. Percutaneous RFA of 14 lung tumors in five dogs was performed under CT guidance. Animals were euthanatized 8-48 hours after the procedure. The lungs and adjacent structures were harvested for gross and histopathologic evaluation. Five solitary pulmonary nodules (range, 17-26 mm) and three clusters of three nodules each (range, 7-17 mm per nodule) were treated with RFA. All ablations were technically successful. Perilesional ground-glass opacity and small asymptomatic pneumothoraces (n = 4) were visualized during the RFA sessions. One dog developed a large pneumothorax treated with tube thoracostomy but was euthanatized 8 hours post-RFA for persistent pneumothorax and continued breathing difficulty. Follow-up CT 48 hours post-RFA revealed opacification of the whole lung segment. Gross and histopathologic evaluation showed complete thermal coagulation necrosis of all treated lesions without evidence of any viable tumor. The region of thermal coagulation necrosis typically extended to the lung surface. Small regions of pulmonary hemorrhage and congestion often surrounded the areas of coagulation necrosis. RFA can be used to treat both solitary pulmonary nodules and clusters of tumor nodules in the canine lung tumor model. This model may be useful for development of specific RFA protocols for human lung tumors.

78 FR 21129 - Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of...

Science.gov (United States)

2013-04-09

... radiofrequency band ranging between 13 megahertz to 27.12 megahertz and is intended for the treatment of medical...] Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting... the public. Name of Committee: Orthopaedic and Rehabilitation Devices Panel of the Medical Devices...

Thermal epiphysiodesis Made with RFA. An Alternative Treatment for Leg Length Discrepancy

DEFF Research Database (Denmark)

Shiguetomi Medina, Juan Manuel

of staples or tension devices, and destruction with curettes or drills. Complications such as breaching of the cortex, damage to the metaphysis, and vascular or nerve injury have potentially serious consequences. Therefore, there is a need for a reliable and precise procedure which overcomes...... the complications. Radiofrequency ablation involves the application of energy in the radio wave frequency resulting in local thermal coagulative necrosis. It has been shown to be a reliable technique for creating thermally induced coagulation necrosis. The experience with this technique has been reported...

Safety work with MRI devices in medicine

International Nuclear Information System (INIS)

Zivkovic, D.; Hrnjak, M.

1999-01-01

This paper gives the basis of biological effects of physical factors which could affect personnel working on MRI devices and patients, and corresponding protection measures. Medical personnel working with MRI devices and patients could be exposed to static magnetic field, time varying fields and radiofrequency radiation, danger from electric current and chemical matters, and there is a high risk from moving metal objects which could wound the persons near-by. The protection from static magnetic field could be ensured by increasing the distance from the source. If MRI device is put in Faradays cage it could be corresponding protection of radiofrequency radiation. (author)

The biological effects of quadripolar radiofrequency sequential application: a human experimental study.

Science.gov (United States)

Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

2014-10-01

An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radiofrequency applications were performed on human full-thickness skin and subcutaneous tissue specimens harvested during surgery for body contouring. In the in vivo assessments the applications were performed on two volunteer patients scheduled for body contouring surgery at the end of the study. The assessment methods were: clinical examination and medical photography, temperature measurement with thermal imaging scan, and light microscopy histological examination. The ex vivo assessments allowed for identification of the effective safety range for human application. The in vivo assessments allowed for demonstration of the biological effects of sequential radiofrequency applications. After a course of radiofrequency applications, the collagen fibers underwent an immediate heat-induced rearrangement and were partially denaturated and progressively metabolized by the macrophages. An overall thickening and spatial rearrangement was appreciated both in the collagen and elastic fibers, the latter displaying a juvenile reticular pattern. A late onset in the macrophage activation after sequential radiofrequency applications was appreciated. Our data confirm the effectiveness of sequential radiofrequency applications in obtaining attenuation of the skin wrinkles by an overall skin tightening.

Laparoscopic resection of a giant exophytic liver haemangioma with the laparoscopic Habib 4× radiofrequency device.

Science.gov (United States)

Acharya, Metesh; Panagiotopoulos, Nikolaos; Bhaskaran, Premjithlal; Kyriakides, Charis; Pai, Madhava; Habib, Nagy

2012-08-27

Haemangiomas are the most common solitary benign neoplasm of the liver with an incidence ranging from 5% to 20%. Although usually small and asymptomatic, they may reach considerable proportions and rarely give rise to life-threatening complications. Surgical intervention is required for incapacitating symptoms, established complications, and diagnostic uncertainty. The resection of haemangiomas demands meticulous surgical technique, owing to their high vascularity and the concomitant risk of intra-operative haemorrhage. Laparoscopic resection of giant haemangiomas is even more challenging, and has only been reported twice. We here report the case of a giant 10 cm liver haemangioma which was successfully resected laparoscopically using the laparoscopic HabibTM 4×, a bipolar radiofrequency device, without clamping major vessels and with minimal blood loss. Transfusion of blood or blood products was not required. The patient had an uneventful recovery and was asymptomatic at 7-mo follow-up.

Multipolar hepatic radiofrequency ablation using up to six applicators: preliminary results

International Nuclear Information System (INIS)

Bruners, P.; Schmitz-Rode, T.; Guenther, R.W.; Mahnken, A.

2008-01-01

Purpose: to evaluate the clinical feasibility and safety of hepatic radiofrequency (RF) ablation using a multipolar RF system permitting the simultaneous use of up to six electrodes. Materials and methods: ten patients (3 female, 7 male, mean age 61) suffering from 29 hepatic metastases (range: 1-5) of different tumors were treated with a modified multipolar RF system (CelonLab Power, Celon Medical Instruments, Teltow, Germany) operating four to six needle-shaped internally cooled RF applicators. The procedure duration, applied energy and generator output were recorded during the intervention. The treatment result and procedure-related complications were analyzed. The achieved coagulation volume was calculated on the basis of contrast-enhanced CT scans 24 hours after RF ablation. Results: complete tumor ablation was achieved in all cases as determined by the post-interventional lack of contrast enhancement in the target region using four applicators in five patients, five applicators in one patient and six applicators in four patients. A mean energy deposition of 353.9 ± 176.2 kJ resulted in a mean coagulation volume of 115.9 ± 79.5 cm 3 . The mean procedure duration was 74.9 ± 21.2 minutes. Four patients showed an intraabdominal hemorrhage which necessitated further interventional treatment (embolization; percutaneous histoacryl injection) in two patients. (orig.)

Effect of Centrifuge Temperature on Routine Coagulation Tests.

Science.gov (United States)

Yazar, Hayrullah; Özdemir, Fatma; Köse, Elif

2018-01-01

This study investigated the effects of cooled and standard centrifuges on the results of coagulation tests to examine the effects of centrifugation temperature. Equal-volume blood samples from each patient were collected at the same time intervals and subjected to standard (25°C) and cooled centrifugation (2-4°C). Subsequently, the prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), fibrinogen, and D-dimer values were determined in runs with the same lot numbers in the same coagulation device using the Dia-PT R (PT and INR), Dia-PTT-liquid (aPTT), Dia-FIB (fibrinogen), and Dia-D-dimer kits, respectively. The study enrolled 771 participants. The PT was significantly (p centrifuges were as follows: PT 10.30 versus 10.50 s; PT (INR) 1.04 versus 1.09 s; APTT 28.90 versus 29.40 s; fibrinogen 321.5 versus 322.1 mg/dL; and D-dimer 179.5 versus 168.7 µg FEU/mL. There were significant differences (p centrifuges. Centrifuge temperature can have a significant effect on the results of coagulation tests. However, broad and specific disease-based studies are needed. © 2018 S. Karger AG, Basel.

The ablated volume and the thermal field distribution in swine vertebral body created by multi-polar radiofrequency ablation: an experiment in vitro

International Nuclear Information System (INIS)

Peng Zhaohong; Zhao Wei; Shen Jin; Hu Jihong; Li Zhaopeng; Wang Tao

2009-01-01

Objective: To observe the extent of bone coagulation and the thermal field distribution created in ablating the swine vertebral bodies in vitro with multi-polar radiofrequency and to discuss the correlation between the electrode position in the vertebral body and the safety of the spinal cord as well as the soft tissue injury around the vertebral body. Methods: Thirty fresh adult porcine vertebrae were randomly and equally divided into two groups. The depth of the electrode needle was 10 mm or 20 mm.When the ablation process reached to a stable state, the temperature at the scheduled spots was estimated. Twenty minutes after ablation, the vertebral body was cut along the electrode needle plane and also along the plane perpendicular to the electrode needle to observe the extent of bone coagulation. Results: The temperature at the scheduled spots reached to a stable state in 3.5 minutes. The more close to the electrode the spot was, the more quickly the temperature rose. No soft tissue injury around the vertebral body was observed in both groups and no spinal cord injury occurred when the electrode needle was 10 mm or 20 mm deep in the vertebral body. Conclusion: In treating vertebral metastases, the radiofrequency ablation is safe and reliable if the posterior wall of the vertebral body remains intact. (authors)

Direct Current Combined With Bipolar Radiofrequency Ablation: An Ex Vivo Feasibility Study

International Nuclear Information System (INIS)

Tanaka, Toshihiro; Penzkofer, Tobias; Isfort, Peter; Bruners, Philipp; Disselhorst-Klug, Catherine; Junker, Elmar; Kichikawa, Kimihiko; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2011-01-01

The combination of radiofrequency ablation (RFA) with direct current (DC) is a promising strategy to improve the efficiency of RFA. However, DC-enhanced monopolar RFA is limited by electrolytic injury at the positive-electrode site. The aim of this study was to investigate the feasibility of the DC-enhanced bipolar RFA. To obviate the need for the subcutaneous positive electrode, the DC circuit was combined with a commercially available bipolar RFA system, in which both poles of the DC circuit are connected to a single RF probe. DC was applied for 15 min and followed by RFA in bovine livers using the following various DC currents: (1) no DC (control), (2) 3V continued until the end of RFA, (3) 5V continued until the end of RFA, (4) 10V continued until the end of RFA, (5) 5V continued in the circuit with reversed pole, (6) 3V stopped after initiation of RFA, and (7) 5V stopped. Coagulation volume, temperatures at a distance of 5, 10, and 15 mm from the RF probe, mean amperage, ablation duration, applied energy, minimum impedance, and degree of tissue charring were assessed and compared (analysis of variance, Student–Newman–Keuls test). All combined DC and RFA groups did increase coagulation volume. The 10V continued group showed significantly lower applied energy, shortest ablation duration, highest minimum impedance, and highest degree of charring with the lowest coagulation volume (p < 0.05). DC-enhanced bipolar RFA with both poles of the DC circuit on a single probe appears to be ineffective.

Radiofrequency tissue ablation with cooled-tip electrodes:an experimental study in a bovine liver model on variables influencing lesion size

International Nuclear Information System (INIS)

Han, Hyun Young; Lee, Jeong Min; Kim, Chong Soo

2001-01-01

The purpose of this study was to determine the influence of various factors on the extent of thermal coagulation necrosis after radiofrequency (RF) tissue ablation using a cooled-tip electrode in bovine liver. RF ablation was induced by a monopolar 500 KHz-RF generator (CC-1; Radionics, Burlington, Mass., U.S.A.) and an 18-G cooled-tip with single or clustered electrodes. The ablation protocol involved a combination of varying current, ablation time, power output, gradual or abrupt increase of this out-put, and pulsed radiofrequency techniques. The maximum diameter of all thermal lesions which showed a color change was measured perpendicular to the electrode axis by two observers who reached their decisions by consensus. Twenty representative lesions were pathologically examined. With increasing current lesion diameter also increased, but above 1500 mA no further increase was induced. Extending the ablation time to 9 minutes for a single electrode and 15 minutes for a clustered electrode increased lesion diameter until a steady state was reached. Higher power levels caused larger lesions, but above 100 W no increase was observed. Ample exposure time coupled with a stepwise increase in power level induced a lesion larger than that resulting from an abrupt increase. Continuous pulsed RF with a high current led to increased coagulation necrosis diameter. These experimental findings may be useful thermotherapy. The data suggest that all involved factors significantly affect lesion size:if the factors are better understood, cancer thermotherapy can be better controlled

WORKSHOPS: Radiofrequency superconductivity

International Nuclear Information System (INIS)

Anon.

1992-01-01

In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991

WORKSHOPS: Radiofrequency superconductivity

Energy Technology Data Exchange (ETDEWEB)

Anon.

1992-01-15

In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991.

An experimental study on hepatic ablation using an expandable radio-frequency needle electrode

International Nuclear Information System (INIS)

Choi, Dong Il; Lim, Hyo Keun; Park, Jong Min; Kang, Bo Kyung; Woo, Ji Young; Jang, Hyun Jung; Kim, Seung Hoon; Lee, Won Jae; Park, Cheol Keun; Heo, Jin Seok

1999-01-01

The purpose of this study was to determine the factors influencing on the size of thermal lesions after ablation using an expendable radio-frequency needle electrode in porcine liver. Ablation procedures involved the use of a monopolar radio-frequency generator and 15-G needle electrodes with four and seven retractable hooks (RITA Medical System, Mountain View, Cal., U.S.A.). The ablation protocol in fresh porcine liver comprised of combinations of varying hook deployment, highest set temperature, and ablation time. Following ablation, the maximum diameter of all thermal lesions was measured on a longitudinal section of the specimen. Ten representive lesions were examined by an experienced pathologist. At 3-cm hook deployment of the needle electrode with four lateral hooks, the size of spherical thermal lesions increased substantially with increases in the highest set temperature and ablation time until 11 minutes. After 11 minutes lesion size remained similar, with a maximum diameter of 3.3 cm. At 2-cm hook deployment, sizes decreased to about 2/3 of those at 3 cm , and at 1-cm hook deployment lesions were oblong. At 3-cm hook deployment of a needle electrode with seven hooks, the size of thermal lesions increased with increasing ablation time until 14 minutes, and the maximum diameter was 4.1 cm. Microscopic examination showed a wide zone of degeneration and focal coagulation necrosis. The size of thermal lesions produced by the use of an expandable radio-frequency needle electrode were predictable, varying according to degree of hook deployment, highest set temperature, and ablation time

TRAITEMENT DES EAUX USEES PAR COAGULATION-FLOCULATION EN UTILISANT LE SULFATE D’ALUMINIUM COMME COAGULANT

OpenAIRE

Nora SEGHAIRI; Leila MIMECHE; Adel BOUZID; Yassir AYACHI

2017-01-01

Domestic wastewater treatment by coagulation-flocculation is widely used internationally. This treatment reduces color and turbidity, indicating organic and inorganic contaminants, but at acceptable levels for treated waste water discharged into the receiving environment. The objective of this study is to optimize the treatment of wastewater by coagulation-flocculation using aluminum sulphate as a coagulant. Various reaction parameters are taken into account, such as the coagulant dose,...

Image-guided radiofrequency ablation (RFA) of spinal tumors

International Nuclear Information System (INIS)

Gevargez, Athour; Groenemeyer, Dietrich H.W.

2008-01-01

Purpose: To evaluate retrospectively the efficacy and safety of radiofrequency ablation (RFA) in patients with spinal tumors. Materials and methods: Forty-one patients (25 men, 16 women; age range, 46-82 years) with nonresectable primary or secondary tumor involvement of the spine unresponsive to chemo- and radiotherapy received RFA treatment. Two radiofrequency ablation systems, one with a cool-tip electrode and one with an expandable electrode catheter, were used. Both systems work impedance controlled with a power output of 150- 200 W. Each coagulation cycle lasted 12-15 min depending on tumor impedance. Several single RFA cycles of 15 min each were used for overlapping RFAs in tumors with diameters of more than 3 cm. Temperature was kept between 50 deg. C and 120 deg. C and was chosen according to spinal cord distance and patient heat tolerance during the ablation. Multi-slice computed tomography (CT) combined with C-arm fluoroscopy guided the intervention. Efficacy outcomes were assessed after about 6 weeks, 6 months, and more than 6 months using standardized questionnaires and indices regarding tumor pain, pain disability, functional activities, quality of life, neurological status, and tumor progression. Results: RFA significantly reduced tumor-induced pain within 6 weeks, improved daily activities, and maintained quality of life. Mean time to tumor progression was 730 ± 54 days (Kaplan-Meier estimate). No RFA-associated complications were reported. Conclusion: RFA of primary and secondary spinal tumors, which were unresponsive to chemo- and radiotherapy and prone to progression, is a safe, resource-saving, and highly effective percutaneous technique in patients with nonresectable spinal tumors

Radiofrequency and health. Expertise update. Opinion of the ANSES. Collective expertise report

International Nuclear Information System (INIS)

Cardis, Elisabeth; Dore, Jean-Francois; Marc-Vergnes, Jean-Pierre; Agnani, Jean-Benoit; Bruguiere, Pierre; Crouzier, David; Debaz, Josquin; Debuire, Brigitte; Deltour, Isabelle; LE Drean, Yves; Ledoigt, Gerard; Letertre, Thierry; Marchand, Dorothee; Massardier-Pilonchery, Amelie; Nadi, Mustapha; Pereira De Vasconcelos, Anne; Hours, Martine; Fite, Johanna; Merckel, Olivier; Roth, Olivia; Vergriette, Benoit; Saddoki, Sophia

2013-10-01

In a context of development of new technologies of wireless communications, and therefore of radio-electric signals used to transmit information, this voluminous document reports a detailed study on the effects of radiofrequency on health. It is notably based on a large literature survey and on an assessment of the level of proof of these effects by experts (proved, possible, probable, insufficiently proved, or no effect on mankind). These effects can be either biological or on health. The report presents the context, scope and modalities of the expertise study, presents the main artificial and natural sources of radiofrequency radiation, gives a detailed presentation of new exposure sources (new signals, new radio-electric networks and their applications like mobile phones, pads, mobile television, local wireless networks, RFID, so on). It describes metrology and dose measurement techniques for electromagnetic fields (exposure characterization in laboratory, characterization of the electromagnetic environment, individual exposure measurement devices, digital dosimetry). It addresses the efficiency of anti-wave devices. The next part presents the literature survey (method, analysis, results). The authors then report an assessment of the risk level related to radio-frequencies for the central nervous system (neurotoxicity mechanisms, cognitive functions, memory and behaviour, sleep and circadian rhythms, hearing functions, neurological and neuro-degenerative diseases), and an assessment of the risk level of radio-frequencies for other non-carcinogenic effects (possible mechanisms, reproduction, immunology, endocrine system, and so on). They discuss the researches on potential carcinogenic mechanisms. They give an overview of the evolutions of regulations and management measures in France, and propose a set of recommendations

Radiofrequency Ablation of Lung Tumors

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Lung Tumors ... and Microwave Ablation of Lung Tumors? What are Radiofrequency and Microwave Ablation of Lung Tumors? Radiofrequency ablation, ...

Blood coagulation factors as inflammatory mediators

NARCIS (Netherlands)

Schoenmakers, Saskia H. H. F.; Reitsma, Pieter H.; Spek, C. Arnold

2005-01-01

After the first observations about blood coagulation by Hippocrates, it took until the early 1900s before the classic theory of blood coagulation was presented. As more and more other coagulation factors were discovered, the four-factor coagulation scheme became more complex, but better understood,

COAGULATION ACTIVITY IN LIVER DISEASE

Directory of Open Access Journals (Sweden)

Dr. Sheikh Sajjadieh Mohammad Reza

2009-07-01

Full Text Available Patients with advanced hepatic failure may present with the entire spectrum of coagulation factor deficiencies. This study was designed to determine laboratory abnormalities in coagulation in chronic liver disease and the association of these abnormalities with the extent of chronic hepatitis and cirrhosis. Coagulation markers were assayed in 60 participants: 20 patients with chronic hepatitis, 20 patients with cirrhosis, and 20 healthy individuals (control. Plasma levels of anti-thrombin III were determined by a chromogenic substrate method, and plasma concentrations of fibrinogen were analyzed by the Rutberg method. Commercially available assays were used for laboratory coagulation tests. The levels of coagualation activity markers in patients with chronic liver disease were significantly different in comparison to those in healthy participants. These results indicate the utility of measuring markers for coagulation activity in determining which cirrhosis patients are more susceptible to disseminated intravascular coagulation.

Coagulation performance of a novel poly-ferric-acetate (PFC) coagulant in phosphate-kaolin synthetic water treatment

Energy Technology Data Exchange (ETDEWEB)

Wei, Yanxin; Lu, Jinpeng; Dong, Xiongzi; Yao, Chengli [Hefei Normal University, Hefei (China); Hao, Jianwen [Anhui Vocational and Technical College, Hefei (China)

2017-10-15

The process of coagulation-flocculation is increasingly applied in wastewater treatment. And the polymerized inorganic coagulants are widely used among these coagulation-flocculation processes. However, conventional coagulants using sulfates or chlorides as counter anion may give rise to corrosion. The purpose of this study was to synthesize PFC coagulants in which acetate is used as counter anion. The influences on the preparation of PFC were optimized. The synthesis was done at the optimum conditions, such as temperature of 60 .deg. C, the Fe/CH{sub 3}COOH molar ratio of 1 : 4.0 and reaction time of 6 h, respectively. The prepared PFC coagulants were characterized by Fourier transform infrared (FTIR) spectrophotometry and scanning electron microscopy (SEM). PFC was found to mainly form complexation polymeric species and present more cluster and lamellar structure. A series of jar tests were carried out to study the coagulation performance of PFC and PFS in phosphate-kaolin synthetic water treatment. Results showed that the coagulation performance of PFC was more efficient than PFS's in terms of the phosphorus removal efficiency and the residual turbidity. Due to using acetate as counter anion to iron, PFC is less harmful to the processes of water treatment and equipment than that of the conventional coagulants applied chlorides or sulfates. Therefore, PFC is a promising coagulant in the process of corrosion sensitive applications and the process of wastewater containing phosphorus treatment.

A 12-week clinical and instrumental study evaluating the efficacy of a multisource radiofrequency home-use device for wrinkle reduction and improvement in skin tone, skin elasticity, and dermal collagen content.

Science.gov (United States)

Sadick, Neil S; Harth, Yoram

2016-12-01

This study was performed in order to evaluate the safety and efficacy of a new handheld home-use multisource radiofrequency device on facial rejuvenation. Forty-seven male and female subjects were enrolled. All subjects received a NEWA ® 3DEEP ™ home-use device (EndyMed Medical, Caesarea, Israel) to be used on facial skin three times per week for the first four weeks and then reduced to two times per week for the following eight weeks. Assessments included expert clinical grading for efficacy, instrumental evaluation, image analysis, and photography. Forty-five subjects completed the study; all subjects reported the treatment to be painless with only mild erythema lasting up to 15 minutes post-treatment. No other adverse events were reported. Statistically significant improvements were noted in the appearance of marionette lines, skin brightness, elasticity, firmness, lift (facial), lift (jawline), texture/smoothness, tone, and radiance/luminosity by expert visual assessment. Statistically significant improvements in skin firmness and elasticity were found using a Cutometer MPA 580, as well as in collagen and hemoglobin content of the skin using a SIAscope. The results of this study indicate that the NEWA ® multisource radiofrequency home-use device is effective in self-administered skin rejuvenation.

Removal of Dye in Wastewater by Adsorption-Coagulation Combined System with Hibiscus sabdariffa as the Coagulant

Directory of Open Access Journals (Sweden)

Hoong Ho Nicholas Jian

2018-01-01

Full Text Available The conventional process to treat dye wastewater is the physicochemical treatment such as coagulation, flocculation and adsorption process. A new approach has been demonstrated to treat Congo red dye wastewater, which is the adsorption-coagulation hybrid process. Natural coagulant extracted from Hibiscus sabdariffa seeds is used as the coagulant while activated carbon is used as the adsorbent in this case study. The objective of this experiment is to study the significant factors that will affect the efficiency of dye removal. Then, the optimum conditions for the hybrid process is determined using Respond Surface Methodology (RSM. The variables are pH, initial dye concentration, coagulant dosage and adsorbent dosage while the response of experiment is the dye removal percentage. A three-level and four-variable Box-Behnken design (BBD is used for the RSM. A total of 27 sets of experimental results is required to determine the optimum conditions. Jar test is used to conduct the experiment with the addition of coagulant and adsorbent simultaneously. Based on the regression model analysis and ANOVA, the highly significant factors that contribute to the dye removal efficiency through adsorption-coagulation hybrid process are pH of solution and initial dye concentration. The RSM results shows that the optimised process parameters for adsorption-coagulation hybrid process with Hibiscus sabdariffa seeds as the coagulant and activated carbon as the adsorbent are pH 2, initial dye concentration of 385 ppm, coagulant dosage of 209 mg/L and adsorbent dosage of 150 mg/L. The dye removal reaches up to 96.67% under optimum parameters.

The investigation of coagulation activity of natural coagulants extracted from different strains of common bean

Directory of Open Access Journals (Sweden)

Šćiban Marina B.

2010-01-01

Full Text Available Coagulation and flocculation by adding chemicals are the methods that are usually used for removal of water turbidity. This study is concerned with the coagulation activity of extracts of various strains of bean. The aim was to ascertain if bean varieties influence coagulation activity. Active components were extracted from 1 g of ground sample with 100 ml distilled water. Contents of dry matter and nitrogen were specified in the solid samples, and the content of soluble nitrogen was determined in the extracts. These data were used to calculate the efficiency of extraction of nitrogen-containing compounds. The coagulation activity was assessed by jar test using synthetic turbid water, of the initial pH 9 and turbidity 35 NTU. The jar test was carried out by adding different amounts of extracts to model water, and stirring the content. After sedimentation for 1 h, residual turbidity was determined by turbidimeter and coagulation activity was calculated. The increment of organic matter concentration after the coagulation was also determined. These experiments confirmed that extracts of all investigated strains of bean could be used successfully as natural coagulants.

Radiofrequency ablation of osteoid osteoma

NARCIS (Netherlands)

Vanderschueren, Geert Maria Joris Michael

2009-01-01

The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency

A pilot study of the efficacy of the POLARGEN® ultrahigh-frequency electric field (40.68 MHz) radiofrequency device in the treatment of facial contouring.

Science.gov (United States)

Kim, Miri; Lim, Jihong; Bae, Jung Min; Park, Hyun Jeong

2017-11-01

Various radiofrequency (RF) devices are used to treat skin laxity and face contouring, but few studies have examined ultrahigh-frequency (UHF) electric field (40.68 MHz) RF devices. To evaluate the efficacy and safety of a UHF electric field (40.68 MHz) RF device for skin tightening and face contouring. Ten patients each underwent four sessions of UHF electric field RF device treatment at 2-week intervals. Clinical improvement was evaluated with the patient satisfaction score using a six-point scale, and clinical photographs taken at every visit and 2 months after the RF treatment were assessed. Skin biopsies were obtained from one patient before the first treatment and immediately after the last treatment. Adverse reactions were recorded at every follow-up visit. All patients were women with a mean age of 51.7 ± 7.2 years. The mean satisfaction score was 4.5 ± 0.9 immediately after the last treatment session. Cheek, jawline, and neck enhancement and tightening were apparent in all patients. Side effects were minimal, and there were no burns or major complications. The UHF electric field RF device was effective for skin tightening and facial contouring, without significant adverse reactions.

Evaluation of the process of coagulation/flocculation of produced water using Moringa oleifera Lam. as natural coagulant

Energy Technology Data Exchange (ETDEWEB)

Santana, C.R.; Pereira, D.F.; Sousa, S.C S N.; Silva, G.F. [Universidade Federal de Sergipe (UFSE), Sao Cristovao, SE (Brazil). Dept. de Engenharia Quimica], e-mail: claudia@ufs.br; Cavalcanti, E.B. [Universidade Tiradentes (UNIT), SE (Brazil). Inst. de Tecnologia e Pesquisa

2010-07-15

In the lifetime of an oil well, there comes a moment when a lot of water begins to be produced along with oil, either by the conditions of the reservoir, or as a result of water injection in the secondary recovery of the well. An important step in such process involves the treatment of the produced water by means of coagulation techniques. Therefore, the use of environmentally correct coagulants is presented as a viable alternative and has demonstrated advantages over the use of chemical coagulants. The plant of the genus Moringa, whose species is oleifera Lam, stands out as one of the most promising natural coagulants. The present study investigated the evaluation of the coagulation/flocculation of produced water, using seeds of Moringa oleifera Lam. as coagulant. The results were very significant, demonstrating that Moringa oleifera Lam. can be used as a natural coagulant in this type of treatment. (author)

Painless, safe, and efficacious noninvasive skin tightening, body contouring, and cellulite reduction using multisource 3DEEP radiofrequency.

Science.gov (United States)

Harth, Yoram

2015-03-01

In the last decade, Radiofrequency (RF) energy has proven to be safe and highly efficacious for face and neck skin tightening, body contouring, and cellulite reduction. In contrast to first-generation Monopolar/Bipolar and "X -Polar" RF systems which use one RF generator connected to one or more skin electrodes, multisource radiofrequency devices use six independent RF generators allowing efficient dermal heating to 52-55°C, with no pain or risk of other side effects. In this review, the basic science and clinical results of body contouring and cellulite treatment using multisource radiofrequency system (Endymed PRO, Endymed, Cesarea, Israel) will be discussed and analyzed. © 2015 Wiley Periodicals, Inc.

Enhanced coagulation for improving coagulation performance and reducing residual aluminum combining polyaluminum chloride with diatomite.

Science.gov (United States)

Hu, Wenchao; Wu, Chunde

2016-01-01

The feasibility of using enhanced coagulation, which combined polyaluminum chloride (PAC) with diatomite for improving coagulation performance and reducing the residual aluminum (Al), was discussed. The effects of PAC and diatomite dosage on the coagulation performance and residual Al were mainly investigated. Results demonstrated that the removal efficiencies of turbidity, dissolved organic carbon (DOC), and UV254 were significantly improved by the enhanced coagulation, compared with PAC coagulation alone. Meaningfully, the five forms of residual Al (total Al (TAl), total dissolved Al (TDAl), dissolved organic Al (DOAl), dissolved monomeric Al (DMAl), and dissolved organic monomeric Al (DOMAl)) all had different degrees of reduction in the presence of diatomite and achieved the lowest concentrations (0.185, 0.06, 0.053, 0.014, and 0 mg L(-1), respectively) at a PAC dose of 15 mg L(-1) and diatomite dose of 40 mg L(-1). In addition, when PAC was used as coagulant, the majority of residual Al existed in dissolved form (about 31.14-70.16%), and the content of DOMAl was small in the DMAl.

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

Energy Technology Data Exchange (ETDEWEB)

Mizandari, Malkhaz [High Technology Medical Center, Tbilisi State Medical University (Georgia); Ao, Guokun [The 309 Hospital of People' s Liberation Army, Department on Oncology (China); Zhang Yaojun; Feng Xi [Imperial College London, Department of Surgery and Cancer (United Kingdom); Shen Qiang [The First Minimally Invasive Department of Eastern Hepatobiliary Surgery Hospital (China); Chen Minshan [Cancer Centre of Sun Yat-Sen University, Department of Hepatobiliary Surgery (China); Lau, Wan Yee [Chinese University of Hong Kong, Department of Surgery, Faculty of Medicine (Hong Kong); Nicholls, Joanna; Jiao Long; Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Imperial College London, Department of Surgery and Cancer (United Kingdom)

2013-02-15

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

Theories of blood coagulation.

Science.gov (United States)

Riddel, James P; Aouizerat, Bradley E; Miaskowski, Christine; Lillicrap, David P

2007-01-01

Although the concept of the coagulation cascade represented a significant advance in the understanding of coagulation and served for many years as a useful model, more recent clinical and experimental observations demonstrate that the cascade/waterfall hypothesis does not fully and completely reflect the events of hemostasis in vivo. The goal of this article is to review the evolution of the theories of coagulation and their proposed models to serve as a tool when reviewing the research and practice literature that was published in the context of these different theories over time.

Thermal Response of In Vivo Human Skin to Fractional Radiofrequency Microneedle Device

Directory of Open Access Journals (Sweden)

Woraphong Manuskiatti

2016-01-01

Full Text Available Background. Fractional radiofrequency microneedle system (FRMS is a novel fractional skin resurfacing system. Data on thermal response to this fractional resurfacing technique is limited. Objectives. To investigate histologic response of in vivo human skin to varying energy settings and pulse stacking of a FRMS in dark-skinned subjects. Methods. Two female volunteers who were scheduled for abdominoplasty received treatment with a FRMS with varying energy settings at 6 time periods including 3 months, 1 month, 1 week, 3 days, 1 day, and the time immediately before abdominoplasty. Biopsy specimens were analyzed using hematoxylin and eosin (H&E, Verhoeff-Van Gieson (VVG, colloidal iron, and Fontana-Masson stain. Immunohistochemical study was performed by using Heat Shock Protein 70 (HSP70 antibody and collagen III monoclonal antibody. Results. The average depth of radiofrequency thermal zone (RFTZ ranged from 100 to 300 μm, correlating with energy levels. Columns of cell necrosis and collagen denaturation followed by inflammatory response were initially demonstrated, with subsequent increasing of mucin at 1 and 3 months after treatment. Immunohistochemical study showed positive stain with HSP70. Conclusion. A single treatment with a FRMS using appropriate energy setting induces neocollagenesis. This wound healing response may serve as a mean to improve the appearance of photodamaged skin and atrophic scars.

Fentanyl Iontophoretic Transdermal System (IONSYS(®)) can be Safely used in the Hospital Environment with X-Rays, Computerized Tomography and Radiofrequency Identification Devices.

Science.gov (United States)

Lemke, John; Sardariani, Edmond; Phipps, Joseph Bradley; Patel, Niki; Itri, Loretta M; Caravelli, James; Viscusi, Eugene R

2016-09-01

Fentanyl iontophoretic transdermal system (fentanyl ITS, IONSYS(®)) is a patient-controlled analgesia system used for the management of acute postoperative pain, designed to be utilized in a hospital setting. The objective of the two studies was to determine if fentanyl ITS could be safely used with X-rays, computerized tomography (CT) scans and radiofrequency identification (RFID) devices. The ITS system has two components: controller and drug unit; the studies utilized ITS systems without fentanyl, referred to as the ITS Placebo system. The first study evaluated the effect of X-radiation on the operation of an ITS Placebo system. Five ITS Placebo systems were exposed to X-rays (20 and 200 mSv total radiation dose-the 200 mSv radiation dose represents a tenfold higher exposure than in clinical practice) while operating in the Ready Mode and five were exposed while operating in the Dose Mode. The second study evaluated the effect of RFID (worst-case scenario of direct contact with an RFID transmitter) on the operation of an ITS Placebo system. During these tests, observations of the user interface and measurements of output voltage confirmed proper function throughout all operational modes (Ready Mode, Dose Mode, End-of-Use Mode, and End-of-Life Mode). The ITS Placebo system met all specifications and no functional anomalies were observed during and following X-ray exposure at two radiation dose levels or exposure at six different combinations of RFID frequencies and field strengths. The performance of the ITS system was unaffected by X-ray exposure levels well beyond those associated with diagnostic X-rays and CT scans, and by exposure to radiofrequency field strengths typically generated by RFID devices. These results provide added confidence to clinicians that the fentanyl ITS system does not need to be removed during diagnostic X-rays and CT scans and can also be utilized in close proximity to RFID devices. The studies and writing of this manuscript were

Preliminary experimental study on splenic hemodynamics of radiofrequency ablation for the spleen.

Science.gov (United States)

Baba, Yasutaka; Hayashi, Sadao; Nagasato, Kohei; Higashi, Michiyo; Yoshiura, Takashi

2017-08-01

To test the splenic blood flow change after radiofrequency ablation (RFA) of the spleen in a porcine experimental model. Six pigs underwent RFA of the spleen via laparotomy. During the procedure of RFA, clamping of splenic artery (one) and both splenic artery/vein (one) was also performed. Measurement of blood flow of both splenic artery (SA) and splenic vein (SV) with flow-wire at pre- and post-RFA of the spleen was also performed. Ablated splenic lesions were created as estimating ∼50% area of the spleen in all pigs. Resected specimens reveal not only the coagulated necrosis but also the congestion of the spleen. On the SA hemodynamics, maximum peak velocity (MPV) changed from 37 ± 7 to 24 ± 8 cm/s (normal), 11 to 10 cm/s (clamp of the SA), and 12 to 7.5 cm/s (clamp of both SA/SV), respectively. On the SV hemodynamic, MPV changed from 15 ± 5 to 13 ± 4 cm/s (normal), 17 to 15 cm/s (clamp of the SA), and 17 to 26 cm/s (clamp of both SA/SV), respectively. RFA of the spleen could induce coagulation necrosis and reduce the splenic arterial blood flow.

Radiotelemetry and wildlife: Highlighting a gap in the knowledge on radiofrequency radiation effects

International Nuclear Information System (INIS)

Balmori, Alfonso

2016-01-01

Radio transmitters and associated devices may induce negative effects that can bias the results of ongoing research. The main documented effects of radio transmitters on animals include reduced survival, decreased productivity, changes in behaviour and movement patterns and a biased sex ratio. The only factors that have claimed responsibility for these possible damages are the weight of the radio transmitter and associated devices, and the attachment type. The electromagnetic radiation produced by radio transmitters has not been considered so far in research. There have been no studies evaluating the effects of non-ionising electromagnetic radiation (radiofrequency signals) necessary for tracking, although the problems found were significantly associated with the length of time that animals had been carrying their radio transmitters. Similar problems as those in radiotracked animals have been found in numerous studies with animals exposed to radiofrequency radiation for a sufficient amount of time. Laboratory scientists investigating the orientation of animals know they have to shield the place where experiments are performed to prevent interference from man-made radiation, as anthropogenic signals may distort the results. It is paradoxical that, at the same time, field scientists investigating the movements and other aspects of animal biology are providing animals with radio transmitters that emit the same type of radiation, since this may affect the results concerning their orientation and movement. This paper identifies gaps in the knowledge that should be investigated in-depth. The possibility that the radiofrequency radiation from radiotracking devices is responsible for the findings should be considered. Considering this factor may allow researchers to best understand the long-term effects found. - Highlights: • Radiotracking may induce negative effects that can bias the results. • Effects have been documented on survival, reproduction and behaviour. �

Radiotelemetry and wildlife: Highlighting a gap in the knowledge on radiofrequency radiation effects

Energy Technology Data Exchange (ETDEWEB)

Balmori, Alfonso, E-mail: balmaral@jcyl.es

2016-02-01

Radio transmitters and associated devices may induce negative effects that can bias the results of ongoing research. The main documented effects of radio transmitters on animals include reduced survival, decreased productivity, changes in behaviour and movement patterns and a biased sex ratio. The only factors that have claimed responsibility for these possible damages are the weight of the radio transmitter and associated devices, and the attachment type. The electromagnetic radiation produced by radio transmitters has not been considered so far in research. There have been no studies evaluating the effects of non-ionising electromagnetic radiation (radiofrequency signals) necessary for tracking, although the problems found were significantly associated with the length of time that animals had been carrying their radio transmitters. Similar problems as those in radiotracked animals have been found in numerous studies with animals exposed to radiofrequency radiation for a sufficient amount of time. Laboratory scientists investigating the orientation of animals know they have to shield the place where experiments are performed to prevent interference from man-made radiation, as anthropogenic signals may distort the results. It is paradoxical that, at the same time, field scientists investigating the movements and other aspects of animal biology are providing animals with radio transmitters that emit the same type of radiation, since this may affect the results concerning their orientation and movement. This paper identifies gaps in the knowledge that should be investigated in-depth. The possibility that the radiofrequency radiation from radiotracking devices is responsible for the findings should be considered. Considering this factor may allow researchers to best understand the long-term effects found. - Highlights: • Radiotracking may induce negative effects that can bias the results. • Effects have been documented on survival, reproduction and behaviour. �

Analysis of the effect of renal excretory system cooling during thermal radiofrequency ablation in an animal model

Directory of Open Access Journals (Sweden)

Andre Meireles

2014-01-01

Full Text Available Objective: Analysis of renal excretory system integrity and efficacy of radiofrequency ablation with and without irrigation with saline at 2 o C (SF2. Materials and Methods: The median third of sixteen kidneys were submitted to radiofrequency (exposition of 1 cm controlled by intra-surgical ultrasound, with eight minutes cycles and median temperature of 90 o C in eight female pigs. One excretory renal system was cooled with SF2, at a 30ml/min rate, and the other kidney was not. After 14 days of post-operatory, the biggest diameters of the lesions and the radiological aspects of the excretory system were compared by bilateral ascending pyelogram and the animals were sacrificed in order to perform histological analysis. Results: There were no significant differences between the diameters of the kidney lesions whether or not exposed to cooling of the excretory system. Median diameter of the cooled kidneys and not cooled kidneys were respectively (in mm: anteroposterior: 11.46 vs. 12.5 (p = 0.23; longitudinal: 17.94 vs. 18.84 (p = 0.62; depth: 11.38 vs. 12.25 (p = 0.47. There was no lesion of the excretory system or signs of leakage of contrast media or hydronephrosis at ascending pyelogram. Conclusion: Cooling of excretory system during radiofrequency ablation does not significantly alter generated coagulation necrosis or affect the integrity of the excretory system in the studied model.

Enhanced algae removal by Ti-based coagulant: comparison with conventional Al- and Fe-based coagulants.

Science.gov (United States)

Xu, Jie; Zhao, Yanxia; Gao, Baoyu; Zhao, Qian

2018-05-01

The water eutrophication caused by cyanobacteria seasonally proliferates, which is a hot potato to be resolved for water treatment plants. This study firstly investigated coagulation performance of titanium tetrachloride (TiCl 4 ) for Microcystis aeruginosa synthetic water treatment. Results show complete algal cell removal by TiCl 4 coagulation without damage to cell membrane integrity even under harsh conditions; 60 mg/L TiCl 4 was effective in removing the microcystins up to 85%. Furthermore, besides having stronger UV 254 removal capability and the higher removal of fluorescent substances over Al- and Fe-based coagulants, TiCl 4 coagulant required more compact coagulation and sedimentation tanks due to its significantly improved floc growth and sedimentation speed. Meanwhile, its' short hydraulic retention time avoided algal cell breakage and subsequent algal organic matter release. Microcystin concentrations were kept at a low level during sludge storage period, indicating that the TiCl 4 flocs could prevent algal cells from natural lysis. To facilitate water recycling without secondary contamination, the algae-containing sludge after TiCl 4 coagulation ought to be disposed within 12 days at 20 °C and 8 days at 35 °C.

The interplay between platelets and coagulation

NARCIS (Netherlands)

Weeterings, C.

2009-01-01

Platelet activation and blood coagulation are two processes often studied separately, but which cannot be seen independently from each other. Platelets play a pivotal role in coagulation, not only by providing negatively charged phospholipids, but also in localizing the coagulation process from a

RADIO-FREQUENCY MASS SPECTROMETERS AND THEIR APPLICATIONS IN SPACE

Energy Technology Data Exchange (ETDEWEB)

Gilmour, Jr., A. S.

1963-08-15

The operation of three common radio-frequency mass spectrometers is described, and their performances are compared. Their limitations are pointed out. It is concluded that the quadrupole spectrometer has fewer limitations and is more generally useful in space probes than the other devices. Some present and proposed uses of spectrometers in space are discussed, and the problem of contamination of the atmosphere being sampled by the spectrometer is reviewed. (auth)

Dust coagulation in ISM

Science.gov (United States)

Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

1989-01-01

Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

Facial tightening with an advanced 4-MHz monopolar radiofrequency device.

Science.gov (United States)

Taub, Amy F; Tucker, Robert D; Palange, Andrea

2012-11-01

Over the past 10 years, radiofrequency (RF) technology has been utilized for nonablative treatments for the treatment of rhytides and skin laxity. This manuscript reviews the scientific background of collagen synthesis in vivo and in response to RF energy as well as a clinical study of 17 patients receiving a series of facial treatments with a 4-MHz monopolar RF (Pellevé, Ellman International, Inc, Oceanside, NY). Clinical methods, results, and a review of the literature for RF aesthetic treatments of the face are presented. Seventeen patients were treated in one site with 6 total treatments scheduled as follows: 1 session was performed every 15 days for 2 consecutive sessions, 1 session every month for 2 consecutive sessions, and 1 session every 2 months for 2 consecutive sessions. Both the treating physician and the patients via live viewing and comparison with baseline photographs performed assessment of results. Results are reported as averages across the 17 patients. Two weeks after the first treatment, patients noted an overall average of 25% to 30% improvement. Just before the last or sixth treatment, there was an average of 50% improvement noted by the physician, with patients ranking an average self-improvement of 48%. The treating physician rated average improvement of 46% compared with baseline, whereas the patients ranked average improvement of 30% compared with baseline at 1 year after treatment was initiated (6 months after the final treatment). Patients find this treatment to be very well tolerated, with minimal to no discomfort and no downtime or significant side effects. The Pellevé 4-MHz monopolar RF device is effective, safe, and very well tolerated for treating laxity, texture, and wrinkles of the skin without complication or discomfort. Evidence in the literature supports the scientific mechanism of action of acute collagen modification and continued neocollagenesis observed with the system. In this cohort, patients maintain approximately 50

An updated concept of coagulation with clinical implications.

Science.gov (United States)

Romney, Gregory; Glick, Michael

2009-05-01

Over the past century, a series of models have been put forth to explain the coagulation mechanism. The coagulation cascade/waterfall model has gained the most widespread acceptance. This model, however, has problems when it is used in different clinical scenarios. A more recently proposed cell-based model better describes the coagulation process in vivo and provides oral health care professionals (OHCPs) with a better understanding of the clinical implications of providing dental care to patients with potentially increased bleeding tendencies. The authors conducted a literature search using the PubMed database. They searched for key words including "coagulation," "hemostasis," "bleeding," "coagulation factors," "models," "prothrombin time," "activated partial thromboplastin time," "international normalized ratio," "anticoagulation therapy" and "hemophilia" separately and in combination. The coagulation cascade/waterfall model is insufficient to explain coagulation in vivo, predict a patient's bleeding tendency, or correlate clinical outcomes with specific laboratory screening tests such as prothrombin time, activated partial thromboplastin time and international normalized ratio. However, the cell-based model of coagulation that reflects the in vivo process of coagulation provides insight into the clinical ramifications of treating dental patients with specific coagulation factor deficiencies. Understanding the in vivo coagulation process will help OHCPs better predict a patient's bleeding tendency. In addition, applying the theoretical concept of the cell-based model of coagulation to commonly used laboratory screening tests for coagulation and bleeding will result in safer and more appropriate dental care.

Removal Natural Organic Matter (NOM in Peat Water from Wetland Area by Coagulation-Ultrafiltration Hybrid Process with Pretreatment Two-Stage Coagulation

Directory of Open Access Journals (Sweden)

Mahmud Mahmud

2016-06-01

Full Text Available The primary problem encountered in the application of membrane technology was membrane fouling. During this time, hybrid process by coagulation-ultrafiltration in drinking water treatment that has been conducted by some research, using by one-stage coagulation. The goal of this research was to investigate the effect of two-stage coagulation as a pretreatment towards performance of the coagulation-ultrafiltration hybrid process for removal NOM in the peat water. Coagulation process, either with the one-stage or two-stage coagulation was very good in removing charge hydrophilic fraction, i.e. more than 98%. NOM fractions of the peat water, from the most easily removed by the two-stage coagulation and one-stage coagulation process was charged hydrophilic>strongly hydrophobic>weakly hydrophobic>neutral hydrophilic. The two-stage coagulation process could removed UV254 and colors with a little better than the one-stage coagulation at the optimum coagulant dose. Neutral hydrophilic fraction of peat water NOM was the most influential fraction of UF membrane fouling. The two-stage coagulation process better in removing the neutral hidrophilic fraction, while removing of the charged hydrophilic, strongly hydrophobic and weakly hydrophobic similar to the one-stage coagulation. Hybrid process by pretreatment with two-stage coagulation, beside can increased removal efficiency of UV254 and color, also can reduced fouling rate of the ultrafiltration membraneIt must not exceed 250 words, contains a brief summary of the text, covering the whole manuscript without being too elaborate on every section. Avoid any abbreviation, unless it is a common knowledge or has been previously stated.

Removal Natural Organic Matter (NOM in Peat Water from Wetland Area by Coagulation-Ultrafiltration Hybrid Process with Pretreatment Two-Stage Coagulation

Directory of Open Access Journals (Sweden)

Mahmud Mahmud

2013-11-01

Full Text Available The primary problem encountered in the application of membrane technology was membrane fouling. During this time, hybrid process by coagulation-ultrafiltration in drinking water treatment that has been conducted by some research, using by one-stage coagulation. The goal of this research was to investigate the effect of two-stage coagulation as a pretreatment towards performance of the coagulation-ultrafiltration hybrid process for removal NOM in the peat water. Coagulation process, either with the one-stage or two-stage coagulation was very good in removing charge hydrophilic fraction, i.e. more than 98%. NOM fractions of the peat water, from the most easily removed by the two-stage coagulation and one-stage coagulation process was charged hydrophilic>strongly hydrophobic>weakly hydrophobic>neutral hydrophilic. The two-stage coagulation process could removed UV254 and colors with a little better than the one-stage coagulation at the optimum coagulant dose. Neutral hydrophilic fraction of peat water NOM was the most influential fraction of UF membrane fouling. The two-stage coagulation process better in removing the neutral hidrophilic fraction, while removing of the charged hydrophilic, strongly hydrophobic and weakly hydrophobic similar to the one-stage coagulation. Hybrid process by pretreatment with two-stage coagulation, beside can increased removal efficiency of UV254 and color, also can reduced fouling rate of the ultrafiltration membraneIt must not exceed 250 words, contains a brief summary of the text, covering the whole manuscript without being too elaborate on every section. Avoid any abbreviation, unless it is a common knowledge or has been previously stated.

Radiofrequency ablation of osteoid osteoma using tissue impedance as a parameter of osteonecrosis

International Nuclear Information System (INIS)

Al-Omari, Ma'moon H.; Al-Muqbel, Kusai M.; Rousan, Liqa A.; Ata, Khalid J.; Mohaidat, Ziyad M.; Haddad, Waleed H.

2012-01-01

The aim of this study is to assess the safety and the efficacy of radiofrequency ablation (RFA) of osteoid osteoma with Soloist monopolar electrode using tissue impedance, rather than temperature, as an indicator of osteonecrosis. The medical records and imaging studies of 30 patients (males 18, females 12) who underwent RFA of osteoid osteoma at our institution were reviewed. The mean age of the patients was 15.3 years (range 5–34 years) and the mean duration of follow up was 26.9 months (range 3–52 months). The lesions were located in the femur (n = 6, 53%), tibia (n = 8, 27%), hand (n = 3, 10%), foot (n = 2, 6%) and humerus (n = 1, 3%). The procedure was performed with general anaesthesia under CT guidance. The nidus was accessed with 11-gauge bone biopsy needle and then the stylet was removed and replaced by monopolar 16.5G radiofrequency probe with a 9-mm active tip through the coaxial axis. Power delivery via the radiofrequency generator was started at 2 W and increased gradually until the end point of 450–500 Ω reached and ‘Roll-Off’ achieved indicating coagulation necrosis of the target lesion. The procedure was technically successful in all patients. The mean procedure time was 72 min and the mean RFA time was 12.7 min. The clinical success rate was 93%. In one patient, the procedure was abandoned due to immature Roll-Off despite all measures. In one patient (3%), recurrence occurred 39 months after the procedure. No major complications were encountered. Two minor skin burns occurred that were resolved with conservative measures. RFA of osteoid osteoma using Soloist monopolar electrode is a safe and effective treatment. Tissue impedance could be used as an alternative to temperature to indicate osteonecrosis of osteoid osteoma during RFA.

Transluminal radio-frequency thermal ablation using a stent-type electrode: an experimental study

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Sun; Rhim, Hyun Chul [Hanyang University College of Medicine, Seoul (Korea, Republic of); Song, Ho Young [Asan Medical Center, Seoul (Korea, Republic of)] [and others

2003-06-01

To assess the feasibility of transluminal radiofrequency thermal ablation using a stent-type electrode and to determine, by means of in-vivo and in-vivo animal studies, the appropriate parameters. In-vivo: the radiofrequency electrode used was a self-expandable nitinol stent with 1cm insulated ends. A stent was placed in the portal vein of bovine liver, and ablations at target temperatures of 70, 80, 90, and 100 .deg. C were performed. Ablated sizes were measured longitudinally. In vivo: four mongrel dogs were anesthetized, and a stent was inserted in the common bile duct under fluoroscopic guidance through an ultrasound-guided gall bladder puncture site. The ablation temperature was set at 80 .deg. C, and each dog underwent proximal and distal esophageal ablations lasting 12 minutes. They were sacrificed immediately. In-vivo: ablated sizes showed significant correlation with target temperatures (r>0.04; p<0.05). Although most lesions were fusiform, dumbbell-shaped lesions with central thinning were found in two cases in the 70 .deg. C group. In all cases in the 70 .deg. C and 80 .deg. C group, the length of the insulated segment was less than 1cm. In-vivo: at microscopy, tissues at the center of the biliary stent showed more prominent pathological change than those at the periphery while those remote from the stent showed minimal or no change. In esophageal ablations, the mean highest temperature was 48.6 .deg. C. Microscopy demonstrated the destruction and shedding of mucosa, edema, and coagulation necrosis of submucosa, but in muscle layers no abnormalities were apparent. Transluminal radio-frequency thermal ablation using a stent-type electrode may be useful for elongating patency. The appropriate target temperature for biliary ablation is 80 .deg. C.

Comparison of expandable electrodes in percutaneous radiofrequency ablation of renal cell carcinoma

International Nuclear Information System (INIS)

Gulesserian, Talin; Mahnken, Andreas H.; Schernthaner, Ruediger; Memarsadeghi, Mazda; Weber, Michael; Tacke, A.; Kettenbach, Joachim

2006-01-01

Objective: To compare two different expandable electrodes in radiofrequency ablation of renal cell carcinoma. Methods: Percutaneous ablation was performed at two centers using either an expandable 7F umbrella-shaped LeVeen TM probe (diameter 2-4 cm) and a 200-W generator (group A), or an expandable Starburst XL TM electrode with a 150-W generator (group B). From each center, eight patients with one tumor each were matched retrospectively with regard to tumor volume, which was 9.71 ± 6.43 cm 3 for group A and 8.74 ± 4.35 cm 3 for group B (mean tumor diameter: 2.47 ± 0.9 cm versus 2.50 ± 0.4 cm, respectively). An unpaired t-test showed no significant difference in tumor volume between the two groups (p = 0.820). Results: Sixteen patients with 16 tumors were treated. The primary technical success of radiofrequency ablation was 94% (15 of 16 patients). After retreatment of residual tumor in one patient from group B, secondary technical success was 100%. No major complications were observed. The resulting mean volume of the almost spherical necroses was 21.1 ± 9.1 cm 3 versus 14.6 ± 6.7 cm 3 for groups A and B (diameter of necrosis: 3.5 ± 0.7 cm versus 3.1 ± 0.6 cm, respectively). A Mann-Whitney U-test showed no significant difference in necrosis volume between the two groups (CI [-0.215; 0.471]; p = 0.2892). The calculated shape value of S (ratio of length to height of the coagulation necrosis) was 0.9 ± 0.1 and 1.0 ± 0.1 for groups A and B, respectively. No local recurrence was observed during a mean follow-up of 14.8 ± 11.6 months, while extrarenal tumor progression occurred in three patients. Conclusions: No significant differences in coagulation volume and shape were found after RF ablation of renal cell carcinoma using two different expandable electrodes. To avoid local recurrence, however, accurate placement of probes and appropriate expansion of the electrode is necessary

In vivo histological evaluation of non-insulated microneedle radiofrequency applicator with novel fractionated pulse mode.

Science.gov (United States)

Harth, Yoram; Frank, Ido

2013-12-01

Microneedle radiofrequency is a novel method that allows non-thermal penetration of the epidermis followed by RF coagulation in selected depth of the dermis surrounded by zone of non-coagulative volumetric heating. The first generation of Microneedle RF applicators used insulated needles. These treatments were limited by a few factors, including low volume of dermal heating, lack of effect in the papillary dermis and pinpoint bleeding during the treatment. The system tested in this study (EndyMed PRO, Intensif applicator, EndyMed Medical, Cesarea, Israel) utilizes special extra sharp tapered non-insulated microneedles and a special pulse mode, allowing full coagulation during treatment and higher effective volume of dermal heat. After Ethics Committee approval, one female pig (Type Large white X Landrace, 34 Kg) was chosen for the study. The animal was anesthetized using Ketamine, Xylazin and Isofluran. The EndyMed PRO, Intensif applicator (was used for treatment with different needle depth penetration (1 mm-3.5 mm) and in multiple energy settings. Six mm punch biopsies were harvested for histological analysis at the following time points: immediately after the treatment, 4 days after the treatment and 14 days after the treatment. H&E and Masson-Trichrome stains were processed. Visual inspection of the treated skin, immediately after the treatment, revealed arrays of pinpoint erythematous papules surrounded by undamaged epidermal tissue. Treatment field showed no sign of bleeding. Mild to moderate Erythema and Edema developed a few minutes after the treatment, varying according to the total energy delivered. The histologies taken 4-day after therapy showed in all energy settings, dry micro crusts over the treatment zones, with full healing of epidermis. In the 14-day specimens there was a replacement of the crusts/debris by a normal looking stratum corneum with complete healing of epidermis and dermis. The current in vivo study confirms that the EndyMed PRO

TRAITEMENT DES EAUX USEES PAR COAGULATION-FLOCULATION EN UTILISANT LE SULFATE D’ALUMINIUM COMME COAGULANT

Directory of Open Access Journals (Sweden)

Nora SEGHAIRI

2017-12-01

Full Text Available Domestic wastewater treatment by coagulation-flocculation is widely used internationally. This treatment reduces color and turbidity, indicating organic and inorganic contaminants, but at acceptable levels for treated waste water discharged into the receiving environment. The objective of this study is to optimize the treatment of wastewater by coagulation-flocculation using aluminum sulphate as a coagulant. Various reaction parameters are taken into account, such as the coagulant dose, the pH of the solutions, the conductivity, the BOD5, the nitrates, the ammonium and the phosphates. We found from the different results obtained the optimal dose of aluminum sulphate is 400 mg/l with a reduction of 96.31%, 82.44% 90.95% and 78.74% respectively for phosphates, nitrates, ammonium and BOD5. It is recognized that pH influences the abatement rates of pollution contained in wastewater. For each water, there is a pH range for which coagulation- flocculation takes place rapidly. For our study, the optimum pH for removal of BOD5 and ammonium is between 6 and 7.

Numerical study of the influence of water evaporation on radiofrequency ablation.

Science.gov (United States)

Zhu, Qing; Shen, Yuanyuan; Zhang, Aili; Xu, Lisa X

2013-12-10

Radiofrequency ablation is a promising minimal invasive treatment for tumor. However, water loss due to evaporation has been a major issue blocking further RF energy transmission and correspondently eliminating the therapeutic outcome of the treatment. A 2D symmetric cylindrical mathematical model coupling the transport of the electrical current, heat, and the evaporation process in the tissue, has been developed to simulate the treatment process and investigate the influence of the excessive evaporation of the water on the treatment. Our results show that the largest specific absorption rate (QSAR) occurs at the edge of the circular surface of the electrode. When excessive evaporation takes place, the water dehydration rate in this region is the highest, and after a certain time, the dehydrated tissue blocks the electrical energy transmission in the radial direction. It is found that there is an interval as long as 65 s between the beginning of the evaporation and the increase of the tissue impedance. The model is further used to investigate whether purposely terminating the treatment for a while allowing diffusion of the liquid water into the evaporated region would help. Results show it has no obvious improvement enlarging the treatment volume. Treatment with the cooled-tip electrode is also studied. It is found that the cooling conditions of the inside agent greatly affect the water loss pattern. When the convection coefficient of the cooling agent increases, excessive evaporation will start from near the central axis of the tissue cylinder instead of the edge of the electrode, and the coagulation volume obviously enlarges before a sudden increase of the impedance. It is also found that a higher convection coefficient will extend the treatment time. Though the sudden increase of the tissue impedance could be delayed by a larger convection coefficient; the rate of the impedance increase is also more dramatic compared to the case with smaller convection

Computational modelling of internally cooled wet (ICW) electrodes for radiofrequency ablation: impact of rehydration, thermal convection and electrical conductivity.

Science.gov (United States)

Trujillo, Macarena; Bon, Jose; Berjano, Enrique

2017-09-01

(1) To analyse rehydration, thermal convection and increased electrical conductivity as the three phenomena which distinguish the performance of internally cooled electrodes (IC) and internally cooled wet (ICW) electrodes during radiofrequency ablation (RFA), (2) Implement a RFA computer model with an ICW which includes these phenomena and (3) Assess their relative influence on the thermal and electrical tissue response and on the coagulation zone size. A 12-min RFA in liver was modelled using an ICW electrode (17 G, 3 cm tip) by an impedance-control pulsing protocol with a constant current of 1.5 A. A model of an IC electrode was used to compare the ICW electrode performance and the computational results with the experimental results. Rehydration and increased electrical conductivity were responsible for an increase in coagulation zone size and a delay (or absence) in the occurrence of abrupt increases in electrical impedance (roll-off). While the increased electrical conductivity had a remarkable effect on enlarging the coagulation zone (an increase of 0.74 cm for differences in electrical conductivity of 0.31 S/m), rehydration considerably affected the delay in roll-off, which, in fact, was absent with a sufficiently high rehydration level. In contrast, thermal convection had an insignificant effect for the flow rates considered (0.05 and 1 mL/min). Computer results suggest that rehydration and increased electrical conductivity were mainly responsible for the absence of roll-off and increased size of the coagulation zone, respectively, and in combination allow the thermal and electrical performance of ICW electrodes to be modelled during RFA.

Predicting nurses' acceptance of radiofrequency identification technology.

Science.gov (United States)

Norten, Adam

2012-10-01

The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

Microwave tissue coagulation: effects of power and treatment time on coagulation size

International Nuclear Information System (INIS)

Kang, Seung Pyung; Kim, Young Hwan; Park, Dong Man; Kim, Jeong Seok; Park, Seo Young; Cha, Soon Joo; Hur, Gham

1999-01-01

To determine the effects of power and coagulation time on lesion size of ex-vivo bovine liver using microwaves. Six bovine livers were divided into two groups (first group : 30W output, second group : 60W output) and microwave coagulation was performed for 30, 60, and 120 sec. Thermal injury site was then observed by means of sonography, and the maximal transverse diameter of the echo-change portion after microwave coagulation was measured. On the section of specimen, maximal transverse diameters of the thermal injury site were measured by gross inspection and compared with the result of sonographic measurement. Maximal transverse diameters of hyperechoic lesions of the first group, as seen on sonography, were 8.3mm, 12.2mm, and 15.6mm, and the maximal transverse diameters of thermal injury sites on gross specimens were 9.1mm, 12.0mm, and 15.1mm, respectively. Maximal transverse diameters of hyperechoic lesions of the second group, as seen on sonography, were 12.1mm, 17.4mm, and 21.2mm and maximal transverse diameters of thermal injury sites on gross specimens were 13.2mm, 16.0mm, and 20.0mm, respectively. Statistically maximal transverse diameters of hyperechoic lesions, as seen on sonography, correlated closely with the gross findings of maximal transverse diameters of thermal injury sites (P < .05). Maximal transverse diameters of thermal injury sites were significantly increased as the output of the microwave coagulator and the duration of coagulation time increased (P < .05)

Conventional Radiofrequency Thermocoagulation vs Pulsed Radiofrequency Neuromodulation of Ganglion Impar in Chronic Perineal Pain of Nononcological Origin.

Science.gov (United States)

Usmani, Hammad; Dureja, G P; Andleeb, Roshan; Tauheed, Nazia; Asif, Naiyer

2018-01-10

Chronic nononcological perineal pain has been effectively managed by ganglion Impar block. Chemical neurolysis, cryoablation, and radiofrequency ablation have been the accepted methods of blockade. Recently, pulsed radiofrequency, a novel variant of conventional radiofrequency, has been used for this purpose. This was a prospective, randomized, double-blind study. Two different interventional pain management centers in India. To compare the efficacy of conventional radiofrequency and pulsed radiofrequency for gangliom Impar block. The patients were randomly allocated to one of two groups. In the conventional radiofrequency (CRF) group (N = 34), conventional radiofrequency ablation was done, and in the PRF pulsed radiofrequency (PRF) group (N = 31), pulsed radiofrequency ablation was done. After informed and written consent, fluoroscopy-guided ganglion Impar block was performed through the first intracoccygeal approach. The extent of pain relief was assessed by visual analog scale (VAS) at 24 hours, and at the first, third, and sixth weeks following the intervention. A questionnaire to evaluate subjective patient satisfaction was also used at each follow-up visit. In the CRF group, the mean VAS score decreased significantly from the baseline value at each follow-up visit. But in the PRF group, this decrease was insignificant except at 24-hour follow-up. Intergroup comparison also showed significantly better pain relief in the CRF group as compared with the PRF group. At the end of follow-up, 28 patients (82%) in the CRF group and four patients (13%) in the PRF group had excellent results, as assessed by the subjective patient satisfaction questionnaire. There was no complication in any patient of either study group, except for short-lived infection at the site of skin puncture in a few. Ganglion Impar block by conventional radiofrequency provided a significantly better quality of pain relief with no major side effects in patients with chronic

Radiofrequency ablation in dermatology

Directory of Open Access Journals (Sweden)

Sachdeva Silonie

2007-01-01

Full Text Available Radiofreqeuency ablation is a versatile dermatosurgical procedure used for surgical management of skin lesions by using various forms of alternating current at an ultra high frequency. The major modalities in radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation in dermatosurgical practice has gained importance in recent years as it can be used to treat most of the skin lesions with ease in less time with clean surgical field due to adequate hemostasis and with minimal side effects and complications. This article focuses on the major tissue effects and factors influencing radiofrequency ablation and its application for various dermatological conditions.

Nano-Scale Devices for Frequency-Based Magnetic Biosensing

Science.gov (United States)

2017-01-31

show the basic measurement setup (the field is applied perpendicular to the disk plane). A radiofrequency signal is injected across the disk (disks...shown in Fig. 7(a). A spectrum analyser (S.A.) (or a high frequency oscilloscope) is used to measure the radiofrequency STO output signal with Fig...crystals and, via electrical measurements , in magnetic-vortex-containing, isolated micro- and nano-devices. Via micromagnetic simulations, we have largely

Improvement in abdominal and flank contouring by a novel adipocyte-selective non-contact radiofrequency device.

Science.gov (United States)

Choi, Sun Young; Kim, Young Jae; Kim, So Yeon; Lee, Woo Jin; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Won, Chonghyun

2018-05-07

The demand for undergoing subcutaneous fat reduction has been gradually increasing, and there are many methods and devices for performing non-surgical and non-invasive fat reduction, such as high-intensity focused ultrasound, cryolipolysis, radiofrequency (RF) devices, and lasers. This study evaluated the efficacy and safety of a novel adipocyte-selective non-contact RF device for improving abdominal contouring in Asian subjects. Twenty-four Asian subjects with abundant subcutaneous abdominal and love handle fat tissues were enrolled in this prospective clinical study. They received six 45-min weekly treatments with an RF field device over the abdominal and love handle regions. The body mass index and abdominal circumference were measured at baseline and at 4 and 8 weeks post the last treatment. The thickness of the abdomen and depth of subcutaneous abdominal fat tissue were respectively assessed using calipers and abdominal ultrasonography. A subset of 15 subjects was selected by randomization for fat volume measurement via abdominal CT. For safety evaluation, serum lipid, and liver-related blood tests were performed at baseline and at the sixth treatment session. Subjects rated their heat perception level using a four point scale and their pain score using an 11-point visual analog scale during RF treatment. Twenty-four subjects (21 females and 3 males) completed this study with an 8-week follow-up. The average decreases in abdominal circumference at 4 and 8 weeks post treatment were 3.48 ± 2.11 cm (P < 0.001) and 5.12 ± 0.47 cm (P < 0.001), respectively. The average decreases in abdominal fat thickness at 4 and 8 weeks treatment were 0.27 ± 0.61 cm (P = 0.041) and 0.47 ± 0.60 cm (P = 0.001), respectively. The average decreases in subcutaneous fat tissue depth at 4 and 8 weeks post treatment were 0.16 ± 0.43 cm (P = 0.091) and 0.34 ± 0.39 cm (P < 0.001), respectively. However, there was no

Emergent self-similarity of cluster coagulation

Science.gov (United States)

Pushkin, Dmtiri O.

A wide variety of nonequilibrium processes, such as coagulation of colloidal particles, aggregation of bacteria into colonies, coalescence of rain drops, bond formation between polymerization sites, and formation of planetesimals, fall under the rubric of cluster coagulation. We predict emergence of self-similar behavior in such systems when they are 'forced' by an external source of the smallest particles. The corresponding self-similar coagulation spectra prove to be power laws. Starting from the classical Smoluchowski coagulation equation, we identify the conditions required for emergence of self-similarity and show that the power-law exponent value for a particular coagulation mechanism depends on the homogeneity index of the corresponding coagulation kernel only. Next, we consider the current wave of mergers of large American banks as an 'unorthodox' application of coagulation theory. We predict that the bank size distribution has propensity to become a power law, and verify our prediction in a statistical study of the available economical data. We conclude this chapter by discussing economically significant phenomenon of capital condensation and predicting emergence of power-law distributions in other economical and social data. Finally, we turn to apparent semblance between cluster coagulation and turbulence and conclude that it is not accidental: both of these processes are instances of nonlinear cascades. This class of processes also includes river network formation models, certain force-chain models in granular mechanics, fragmentation due to collisional cascades, percolation, and growing random networks. We characterize a particular cascade by three indicies and show that the resulting power-law spectrum exponent depends on the indicies values only. The ensuing algebraic formula is remarkable for its simplicity.

Evaluation of the clinical efficacy of fractional radiofrequency microneedle treatment in acne scars and large facial pores.

Science.gov (United States)

Cho, Soo Ick; Chung, Bo Young; Choi, Min Gyu; Baek, Ji Hwoon; Cho, Hee Jin; Park, Chun Wook; Lee, Cheol Heon; Kim, Hye One

2012-07-01

Fractional technology overcomes the problems of ablative lasers, such as inaccurate depth control and damage to the epidermis. Minimally invasive fractional radiofrequency microneedle devices allow for more-selective heating of the dermis. To evaluate the clinical efficacy of fractional radiofrequency microneedle (ERM) treatment in acne scars and large facial pores. Thirty patients with acne scars and large facial pores were enrolled. Bipolar radiofrequency energy was delivered to the skin through the electrodes of the FRM device. Skin lesions were evaluated according to grade of acne scars, Investigator Global Assessment of large pores, skin surface roughness, transepidermal water loss (TEWL), dermal density, microscopic and composite image, sebum measurement, and questionnaires regarding patient satisfaction. The grade of acne scars and Investigator Global Assessment of large pores improved in more than 70% of all patients. Skin surface roughness, dermal density, and microscopic and composite images also improved, whereas TEWL and sebum measurement did not change. Clinical improvement from FRM treatment appeared to be related to dermal matrix regeneration. FRM treatment may be effective in improving acne scars and facial pores. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

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

Vacuum pumping system for the JT-60 radio-frequency heating system

International Nuclear Information System (INIS)

Yokokura, Kenji; Ikeda, Yoshitaka; Imai, Tuyoshi; Suganuma, Kazuaki; Nagashima, Takashi

1988-01-01

The basic design requirements set up for the JT-60 radio-frequency heating system included: (1) rapid pumping of gas released upon application of a radio-frequency power to maintain the pressure in the launchers at 10 -2 - 10 -3 Pa or less, (2) incorporation of a gas analysis system that can operate under a strong field and high pressure (>10 -2 Pa) to permit remote controlled data collection and processing, and (3) low cost, multiple functions and high reliability. The vacuum pumping system, consisting of three units for low hybrid radio-frequency (LHRF) and one unit for ion cyclotron radio-frequency (ICRF), is connected to each launcher provided at the four ports of JT-60. The LHRF unit is composed of a main pump, an alumina joint for electrical insulation from the launcher, a metallic gate valve for isolation from the JT-60 vacuum region, and various vacuum gauges. Only a turbo-molecular pump is used for the ICRF system because a large-scale differential pumping is not required. A gas measuring system is incorporated which consists of a mass filter, personal computer, turbo-molecular pump, and variable flow valve equipped with an APG control. This system is designed to identify and make use of gas impurities released during the launcher aging process. The control system employed consists of a personal computer, interlock control board, data logger and other devices such as vacuum gages. (Nogami, K.)

Transport Characteristics of Mesoscopic Radio-Frequency Single Electron Transistor

International Nuclear Information System (INIS)

Phillips, A. H.; Kirah, K.; Aly, N. A. I.; El-Sayes, H. E.

2008-01-01

The transport property of a quantum dot under the influence of external time-dependent field is investigated. The mesoscopic device is modelled as semiconductor quantum dot coupled weakly to superconducting leads via asymmetric double tunnel barriers of different heights. An expression for the current is deduced by using the Landauer–Buttiker formula, taking into consideration of both the Coulomb blockade effect and the magnetic field. It is found that the periodic oscillation of the current with the magnetic field is controlled by the ratio of the frequency of the applied ac-field to the electron cyclotron frequency. Our results show that the present device operates as a radio-frequency single electron transistor

CT-guided radiofrequency tumor ablation in children

International Nuclear Information System (INIS)

Botsa, Evanthia; Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas; Koutsogiannis, Ioannis; Ziakas, Panayiotis D.; Alexopoulou, Efthimia

2014-01-01

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

CT-guided radiofrequency tumor ablation in children

Energy Technology Data Exchange (ETDEWEB)

Botsa, Evanthia [National and Kapodistrian University of Athens, First Pediatric Clinic, Agia Sofia Children' s Hospital, Athens (Greece); Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas [Sotiria General Hospital for Chest Diseases, Department of Medical Imaging and Interventional Radiology, Athens (Greece); Koutsogiannis, Ioannis [General Military Hospital NIMTS, Department of Medical Imaging, Athens (Greece); Ziakas, Panayiotis D. [Warren Alpert Medical School of Brown University Rhode Island Hospital, Division of Infectious Diseases, Providence, RI (United States); Alexopoulou, Efthimia [Attikon University Hospital, Second Department of Radiology, Athens University School of Medicine, Athens (Greece)

2014-11-15

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

Enhanced WWTP effluent organic matter removal in hybrid ozonation-coagulation (HOC) process catalyzed by Al-based coagulant

Energy Technology Data Exchange (ETDEWEB)

Jin, Xin [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Jin, Pengkang, E-mail: pkjin@hotmail.com [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Hou, Rui [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Yang, Lei [Department of Materials Science and Engineering, Monash University, Clayton, VIC, 3800 (Australia); Wang, Xiaochang C., E-mail: xcwang@xauat.edu.cn [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China)

2017-04-05

Highlights: • A novel HOC process was firstly put forward to apply in wastewater reclamation. • Interactions between ozone and Al-based coagulants was found in the HOC process. • Ozonation can be catalyzed and enhanced by Al-based coagulants in the HOC process. • HOC process showed better organics removal than pre-ozonation-coagulation process. - Abstract: A novel hybrid ozonation-coagulation (HOC) process was developed for application in wastewater reclamation. In this process, ozonation and coagulation occurred simultaneously within a single unit. Compared with the conventional pre-ozonation-coagulation process, the HOC process exhibited much better performance in removing dissolved organic matters. In particular, the maximal organic matters removal efficiency was obtained at the ozone dosage of 1 mgO{sub 3}/mg DOC at each pH value (pH 5, 7 and 9). In order to interpret the mechanism of the HOC process, ozone decomposition was monitored. The results indicated that ozone decomposed much faster in the HOC process. Moreover, by using the reagent of O{sub 3}-resistant hydroxyl radical (·OH) probe compound, para-chlorobenzoic acid (pCBA), and electron paramagnetic resonance (EPR) analysis, it was observed that the HOC process generated higher content of ·OH compared with pre-ozonation process. This indicates that the ·OH oxidation reaction as the key step can be catalyzed and enhanced by Al-based coagulants and their hydrolyzed products in this developed process. Thus, based on the catalytic effects of Al-based coagulants on ozonation, the HOC process provides a promising alternative to the conventional technology for wastewater reclamation in terms of higher efficiency.

Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

Science.gov (United States)

Sage, Cindy; Burgio, Ernesto

2018-01-01

Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

RADIOFREQUENCY SUPERCONDUCTIVITY: Workshop

International Nuclear Information System (INIS)

Lengeler, Herbert

1989-01-01

Superconducting radiofrequency is already playing an important role in the beam acceleration system for the TRISTAN electron-positron collider at the Japanese KEK Laboratory and new such systems are being prepared for other major machines. Thus the fourth Workshop on Radiofrequency Superconductivity, organized by KEK under the chairmanship of local specialist Yuzo Kojima and held just before the International Conference on High Energy Accelerators, had much progress to review and even more to look forward to

THE RATIONALIZATION OF THE PARAMETERS OF MILK PROTEINS’ THERMO ACID COAGULATION BY BERRY COAGULANTS

Directory of Open Access Journals (Sweden)

Olena GREK

2017-03-01

Full Text Available This paper presents the results related to the influence of berry coagulant amount, its proactive acidity and duration of thermo acid coagulation on the process of milk proteins’ sedimentation. In the present work, the regression equations and response surface analysis were used to design and optimize an industrial bioprocess. Increase in the berry coagulant amount to 11 % and reduction of active acidity to 2.4 units were determined. pH up to 3 minutes is characterized by the highest processes of destabilization. Moreover, it improves the organoleptic properties and has the biggest impact on the yield of protein-berry clot (to 25 % and active acidity.

Occupational exposure of NRM spectrometrists to static and radiofrequency fields

International Nuclear Information System (INIS)

Berlana, Tania; Ubeda, Alejandro

2017-01-01

Occupational exposure to static and radiofrequency fields emitted by nuclear magnetic resonance spectrometers was assessed through systematic field metering during operation of 19 devices in nine research centers. Whereas no measurable levels of radiofrequency radiation were registered outside the spectrometers, significant exposure to static field was detected, with maximum values recorded at the user s hand (B = 683.00 mT) and head thorax (B = 135.70 mT) during spectrometer manipulation. All values were well below the exposure limits set by the European standard for workers protection against the effects of acute field exposure only. As for potential effects of chronic exposure, waiting for more complete knowledge, adoption of technical and operational strategies for exposure minimizing is advisable. In this respect, the data revealed that compared with standard magnetic shielding, ultra-shield technology allows a 20-65-fold reduction of the field strength received by the operator. (authors)

Treatment of cellulite with a bipolar radiofrequency, infrared heat, and pulsatile suction device: a pilot study.

Science.gov (United States)

Wanitphakdeedecha, Rungsima; Manuskiatti, Woraphong

2006-12-01

Very few therapeutic options have proven effective in the treatment of cellulite. To evaluate the effectiveness and adverse effects of a bipolar radiofrequency (RF), infrared (IR) heat and pulsatile suction device for the treatment of cellulite. Twelve subjects were treated with the RF-light-based device. All subjects were treated twice weekly for a total number of eight to nine treatments. Subjects were evaluated using standardized photographs, and measurements of body weight and circumference of treatment sites at baseline, immediately after the last treatment, and four weeks and one year after the last treatment. Clinical improvement scores of comparable photographs using a quartile grading scale (0 = 75% improvement) were judged independently by two non-treating dermatologists after the series of treatment. The average body weights at baseline, immediately after the last treatment, and four weeks and one year after the complete treatment were 56.30, 56.05, 56.23, and 56.53 kg, respectively. The average circumferential reductions of the abdomen and thigh at the last treatment visit were 5.17 +/- 1.04 cm (6.32%+/- 1.82%) and 3.50 +/- 2.16 cm (6.23 +/- 3.58%), respectively. At four weeks after the last treatment, the average circumferential reductions of the abdomen and thigh were sustained at 3.17 +/- 2.75 cm (4.04%+/- 3.69%) and 3.50 +/- 2.04 cm (6.26%+/- 3.52%), respectively. At one year follow-up visit, the average circumferential reductions of the abdomen and thigh were maintained at 3.83 +/- 0.76 cm (4.64%+/- 1.15%) and 3.13 +/- 3.54 (5.50%+/- 6.12%), respectively. Average clinical improvement scores of the abdomen and thigh after the series of treatments were 0.75 (corresponding to approximately 25% improvement), and 1.75 (corresponding to approximately 50% improvement), respectively. A bipolar RF, IR heat and pulsatile suction device provides a beneficial effect on reduction of abdomen and thigh circumference, and smoothening of the cellulite.

Magnetic particle imaging of blood coagulation

Energy Technology Data Exchange (ETDEWEB)

Murase, Kenya, E-mail: murase@sahs.med.osaka-u.ac.jp; Song, Ruixiao; Hiratsuka, Samu [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan)

2014-06-23

We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

Ultrasound-guided radiofrequency thermal ablation of normal kidney in a rabbit model: correlation with CT and histopathology

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Won; Lee, Jeong Min; Kin, Chong Soo; Lee, Sang Hun [College of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

2002-01-01

To assess the feasibility and safety of using a cooled-tip electrode to perform percutaneous radiofrequency ablation of kidney tissue in rabbits, and to evaluate the ability of CT to reveal the appearance and extent of tissue necrosis during follow-up after ablation. Using ultrasound guidance, a 17-G cooled-tip electrode was inserted into the right lower portion of the kidney in 26 New Zealand White rabbits. Radiofrequency was applied for 2 mins, and biphasic helical CT scanning was used to assess tissue destruction and the presence or absence of complications immediately after the procedure and at 24 hrs, 2 and 3 days, and 1,2,3,4,5,6 and 7 weeks. The study had three phases: acute (immediately killed : N=10); subacute (killed at 24 hrs (n=3), 2 days (n=3), 3 days (n=1) : N=7); chronic (killed at 1 week (n=4), 2 weeks (n=2), 4 weeks (n=1), 7 weeks (n=1): N=8). After the animals were killed, their kidneys were histopathologically examined and the radiologic and pathologic findings of lesion size and configuration were correlated. In each instance, ultrasound-guided radiofrequency ablations of the lower pole of the kidney were technically successful. Contrast-enhanced biphasic helical CT revealed regions of hypoattenuation devoid of parenchymal enhancement, and these correlated closely with true pathologic lesion size (r=0.884; p>0.05). In subacute and chronic models, CT scanning revealed gradual spontaneous resorption of the ablated lesion and the presence of perilesional calcification. Histopathologically, in the acute phase the ablated lesion showed coagulative necrosis and infiltration of inflammatory cells, and in the chronic phase there was clear cut necrosis of glomeruli, tubules and renal interstitium, with diminishing inflammatory response and peripheral fibrotic tissue formation. Ultrasound-guided renal radiofrequency ablation is technically feasible and safe. In addition, the avascular lesion measured at contrast-enhanced helical CT closely correlated with

Ultrasound-guided radiofrequency thermal ablation of normal kidney in a rabbit model: correlation with CT and histopathology

International Nuclear Information System (INIS)

Kim, Sang Won; Lee, Jeong Min; Kin, Chong Soo; Lee, Sang Hun

2002-01-01

To assess the feasibility and safety of using a cooled-tip electrode to perform percutaneous radiofrequency ablation of kidney tissue in rabbits, and to evaluate the ability of CT to reveal the appearance and extent of tissue necrosis during follow-up after ablation. Using ultrasound guidance, a 17-G cooled-tip electrode was inserted into the right lower portion of the kidney in 26 New Zealand White rabbits. Radiofrequency was applied for 2 mins, and biphasic helical CT scanning was used to assess tissue destruction and the presence or absence of complications immediately after the procedure and at 24 hrs, 2 and 3 days, and 1,2,3,4,5,6 and 7 weeks. The study had three phases: acute (immediately killed : N=10); subacute (killed at 24 hrs (n=3), 2 days (n=3), 3 days (n=1) : N=7); chronic (killed at 1 week (n=4), 2 weeks (n=2), 4 weeks (n=1), 7 weeks (n=1): N=8). After the animals were killed, their kidneys were histopathologically examined and the radiologic and pathologic findings of lesion size and configuration were correlated. In each instance, ultrasound-guided radiofrequency ablations of the lower pole of the kidney were technically successful. Contrast-enhanced biphasic helical CT revealed regions of hypoattenuation devoid of parenchymal enhancement, and these correlated closely with true pathologic lesion size (r=0.884; p>0.05). In subacute and chronic models, CT scanning revealed gradual spontaneous resorption of the ablated lesion and the presence of perilesional calcification. Histopathologically, in the acute phase the ablated lesion showed coagulative necrosis and infiltration of inflammatory cells, and in the chronic phase there was clear cut necrosis of glomeruli, tubules and renal interstitium, with diminishing inflammatory response and peripheral fibrotic tissue formation. Ultrasound-guided renal radiofrequency ablation is technically feasible and safe. In addition, the avascular lesion measured at contrast-enhanced helical CT closely correlated with

Efficacy of percutaneous intraductal radiofrequency ablation combined with biliary stenting in treatment of malignant biliary obstruction

Directory of Open Access Journals (Sweden)

ZHANG Kai

2015-05-01

Full Text Available ObjectiveTo investigate the safety and feasibility of percutaneous intraductal radiofrequency ablation (palliative therapy in the treatment of malignant obstructive jaundice. MethodsThis study included 20 patients with unresectable malignant obstructive jaundice, who were treated in the First Affiliated Hospital of Zhengzhou University from January 2013 to March 2014. Nine of them (test group underwent percutaneous intraductal radiofrequency ablation plus metallic biliary stent placement. The other 11 similar cases (control group underwent metallic biliary stent placement alone after successful percutaneous transhepatic cholangiography. Operative complications and remission of jaundice were observed, and the stent patency after at 3 and 6 months after operation was evaluated and compared between the two groups. ResultsAll patients were followed completely by outpatient or telephone. The stent patency rate at 3 months after operation was 9/9 in the test group and 8/11 in the control group (χ2=2.888, P=0.218, and the stent patency rates at 6 months were 7/8 and 3/11, respectively (χ2=6.739, P=0.02. During follow-up, one case in the test group died of gastrointestinal bleeding at 113 d after operation; one case in the control group died of liver failure at 57 d after operation and one case died of disseminated intravascular coagulation at 142 d. ConclusionPercutaneous intraductal radiofrequency ablation is safe and feasible in the treatment of malignant biliary obstruction, and the preliminary efficacy in prolonging the patency of self-expanding metallic stent is satisfactory. However, this therapy needs to be further verified via large-sample randomized controlled studies.

Radiofrequency thermal ablation of benign cystic lesion: an experimental pilot study in a porcine gallbladder model

International Nuclear Information System (INIS)

Song, Ho Taek; Rhim, Hyun Chul; Choi, Jung Bin; Oh, Jae Cheon; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Seo, Heung Suk; Joo, Kyung Bin

2001-01-01

To determine whether radiofrequency thermal ablation can be used to treat benign cystic lesions in a porcine gallbladder model. This experimental study of radiofrequency thermal ablation involved the use of 15 exvivo porcine gallbladders and 15-G expandable needle electrodes. To investigate optimal temperature parameters, three groups of five were designated according to target temperature:Group A: 70 deg C; Group B: 80 deg C; Group C: 90 deg C. After the target temperature was reached, ablation lasted for one minute. Gallbladder width, height and length were measured before and after ablation , and the estimated volume reduction ratios of the three groups were compared. Whether adjacent liver parenchyma around the gallbladder fossa was ablated by heat conducted from hot bile was also determined, and the thickness of the ablated area of the liver was measured. The volume reduction ratio in Group A, B and C was 42.7%, 41.7% and 42.9%, respectively (ρ>.05). In all 15 cases, gallbladder walls lost their transparency and elasticity at about 70 deg C. In nine of ten cases in Groups B and C, the hepatic capsule around the gallbladder fossa was retracted at about 80 deg C. The mean thickness of liver parenchymal damage adjacent to the gallbladder was 5.4 mm in Group B and 9.8 mm in Group C. In Group A livers, only one case showed minimal gradual parenchymal change. Microscopically, all three groups showed complete coagulation necrosis of the wall. On the basis of this feasibility study, radiofrequency thermal ablation is potentially suitable for the ultrasound-guided treatment of symptomatic cystic lesions including benign hepatic or renal cyst

Wireless communication with implanted medical devices using the conductive properties of the body.

Science.gov (United States)

Ferguson, John E; Redish, A David

2011-07-01

Many medical devices that are implanted in the body use wires or wireless radiofrequency telemetry to communicate with circuitry outside the body. However, the wires are a common source of surgical complications, including breakage, infection and electrical noise. In addition, radiofrequency telemetry requires large amounts of power and results in low-efficiency transmission through biological tissue. As an alternative, the conductive properties of the body can be used to enable wireless communication with implanted devices. In this article, several methods of intrabody communication are described and compared. In addition to reducing the complications that occur with current implantable medical devices, intrabody communication can enable novel types of miniature devices for research and clinical applications.

Long-term three-dimensional volumetric assessment of skin tightening using a sharply tapered non-insulated microneedle radiofrequency applicator with novel fractionated pulse mode in asians.

Science.gov (United States)

Tanaka, Yohei

2015-10-01

Non-insulated microneedle radiofrequency (NIMNRF) is a novel method that allows non-thermal penetration of the epidermis followed by radiofrequency (RF) coagulation at selected depths of the dermis that are surrounded by a zone of non-coagulative volumetric heating. The objective of this study was to investigate subjectively and objectively the efficacy of a single fractional NIMNRF treatment. Twenty Japanese patients underwent full face skin tightening using a sharply tapered NIMNRF applicator with a novel fractionated pulse mode. The system platform (1MHZ) incorporated six independent phase controlled RF generators coupled to RF microneedles that induced skin remodeling via controlled dermal coagulation. Patients received from 500 to 1000 pulses that were 80-110 milliseconds in duration at a power of 10-14 W, and a 1.5-2.5 mm penetration depth. Topical anesthetic cream was applied before the treatment. Monthly three-dimensional (3-D) volumetric assessments were performed for 6 months after treatment. Patients rated their satisfaction using a 5-point scale. During the study patients showed significant skin tightening on the lower two-thirds of the face. Objective assessments with superimposed 3-D color images showed significant median volumetric reduction of 12.1 ml at 6 months post-treatment. Ninety percent of the patients were either "satisfied" or "very satisfied" with the treatment results. The treatments were well tolerated with minimal discomfort. Complications included a slight burning sensation and mild erythema that were minor and transitory; both resolved within 5 hours. Side effects such as post-inflammatory hyperpigmentation, epidermal burns, and scar formation were not observed. The advantages of this NIMNRF treatment for skin tightening are its long-lasting high efficacy as shown through 3-D volumetric assessments. Moreover, NIMNRF produced minimal complications and downtime as well as few side effects. This non-invasive novel fractional NIMNRF

Radiofrequency ablation of lung tumours. New perspective in treatment of lung neoplasms

International Nuclear Information System (INIS)

Kocijancic, K.; Kocijancic, I.

2007-01-01

Percutaneous radiofrequency ablation (RFA) is a minimally invasive technique used to treat solid tumours. Because of its ability to produce large volume of coagulation necrosis in controlled fashion this technique has been progressively tested as a possible treatment of lung malignancies. Recent clinical studies have shown that RFA enables successful treatment of relatively small lung malignancies with high rate of complete response and acceptable morbidity and have suggested that the technique could represent a viable alternate or complementary method for patients with non-small cell lung cancer or lung metastases of favourable histotypes who are not candidates for surgical resection. Initial international studies as well as the clinical experience of Institute of Radiology in Clinical Center Ljubljana, although limited, indicated that RFA is mostly well tolerated by patients and also, that it can result in complete necrosis of targeted lesion. Pneumothorax is most common procedure related complication, occurring in up to 40% of cases, with approx. half of them requiring drainage. (author)

Hemorrhoidectomy: pedicle ligation vs pedicle coagulation

International Nuclear Information System (INIS)

Shaikh, B.S.; Balaoch, I.B.; Sohu, K.M.

2015-01-01

Objective: To compare the outcome of pedicle ligation vs pedicle coagulation haemorrhoidectomy. Methodology: This comparative prospective study was carried out at Department of Surgery, Ghulam Muhammad Maher Medcial College Hospital, Sukkur, Pakistan from January 2011 to January 2013 and included 300 patients of hemorrhoids. After routine workup, patients were randomly divided into two equal groups with one group receiving pedicle ligation and other pedicle coagulation for hemorrhoidectomy. Postoperatively they were followed for a period of 8 weeks for complications including pain, urinary retention, bleeding and anal stricture. Pain was recorded up to 10th postoperative day on the basis of visual analogue scale. Results: Mean age was 45 years and male to female ratio was 1.7:1. Mean operative time in pedicle ligation group was 15 min (range 14-20 min) and 17 min (15-25 min) in pedicle coagulation group. In Pedicle ligation group, pain was worst in 35 patients, moderate in 85 and mild in 30 patients; on the other hand in pedicle coagulation group, just 09 patients experienced worst pain. Urinary retention was observed in 44 patients in pedicle ligation group and 19 in pedicle coagulation group. Five patients in pedicle ligation group developed bleeding after their discharge from hospital; 7 patients in pedicle coagulation group reported secondary bleeding. Anal stricture was a rare complication and was found equally common in both the groups. Conclusion: Conventional hemorrhoidectomy with pedicle coagulation is an effective treatment modality for hemorrhoids and is associated with less chance of postoperative anal pain and urinary retention. (author)

High temperature radio-frequency superconducting quantum interference device system for detection of magnetic nanoparticles

International Nuclear Information System (INIS)

Pretzell, Alf

2012-01-01

This doctoral thesis was aimed at establishing a set-up with high-temperature superconductor (HTS) radio-frequency (rf) superconducting quantum interference device (SQUID) technology for the detection of magnetic nanoparticles and in particular for testing applications of magnetic nanoparticle immunoassays. It was part of the EU-project ''Biodiagnostics'' running from 2005 to 2008. The method of magnetic binding assays was developed as an alternative to other methods of concentration determination like enzyme linked immunosorbent assay (ELISA), or fluorescent immunoassay. The ELISA has sensitivities down to analyte-concentrations of pg/ml. Multiple incubation and washing steps have to be performed for these techniques, the analyte has to diffuse to the site of binding. The magnetic assay uses magnetic nanoparticles as markers for the substance to be detected. It is being explored by current research and shows similar sensitivity compared to ELISA but in contrast - does not need any washing and can be read out directly after binding - can be applied in solution with opaque media, e.g. blood or muddy water - additionally allows magnetic separation or concentration - in combination with small magnetoresistive or Hall sensors, allows detection of only a few particles or even single beads. For medical or environmental samples, maybe opaque and containing a multitude of substances, it would be advantageous to devise an instrument, which allows to be read out quickly and with high sensitivity. Due to the mentioned items the magnetic assay might be a possibility here.

Inductance mode characteristics of a ceramic YBa2Cu3O7-x radio-frequency superconducting quantum interference device at 77 K

DEFF Research Database (Denmark)

Il'ichev, E. V.; Andreev, A. V.; Jacobsen, Claus Schelde

1993-01-01

Experimental results on some radio-frequency superconducting quantum interference device (rf-SQUID) signal properties are presented. The quantum interferometer was made of ceramic YBa2Cu3O7−x and was due to a low critical current operated in the inductance or nonhysteretic mode. With bias current...... as reference, amplitude variation, and phase shift of the voltage over the tank circuit coupled to the SQUID were measured simultaneously. It is shown that there is qualitative agreement between calculations based on the resistivity shunted junction model and the data. Moreover, using phase detection, signal...... instabilities predicted for the rf-SQUID inductance mode were observed. These signal instabilities may be exploited to enhance the transfer coefficient for measured flux-to-output signal. Journal of Applied Physics is copyrighted by The American Institute of Physics....

Radiofrequency Energy and Electrode Proximity Influences Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation Lesion Size: An In Vitro Study with Clinical Correlation.

Science.gov (United States)

Staudt, Michael D; Maturu, Sarita; Miller, Jonathan P

2018-02-16

Radiofrequency thermocoagulation of epileptogenic foci via stereoelectroencephalography (SEEG) electrodes has been suggested as a treatment for medically intractable epilepsy, but reported outcomes have been suboptimal, possibly because lesions generated using conventional high-energy radiofrequency parameters are relatively small. To describe a technique of delivering low energy across separate SEEG electrodes in order to create large confluent radiofrequency lesions. The size and configuration of radiofrequency lesions using different radiofrequency intensity and interelectrode distance was assessed in egg whites. Magnetic resonance images (MRI) from 3 patients who had undergone radiofrequency lesion creation were evaluated to determine the contribution of lesion intensity and electrode separation on lesion size. Electroencephalography, MRI, and clinical data were assessed before and after lesion creation. Both in Vitro and in Vivo analysis revealed that less energy paradoxically produced larger lesions, with the largest possible lesions produced when radiofrequency power was applied for long duration at less than 3 W. Linear separation of electrodes also contributed to lesion size, with largest lesions produced when electrodes were separated by a linear distance of between 5 and 12 mm. Clinical lesions produced using these parameters were large and resulted in improvement in interictal and ictal activity. Radiofrequency lesions produced using low-energy delivery between SEEG electrodes in close proximity can produce a large lesion. These findings might have advantages for treatment of focal epilepsy.

Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

Science.gov (United States)

Cartier, Victoire; Boursier, Jérôme; Lebigot, Jérôme; Oberti, Frédéric; Fouchard-Hubert, Isabelle; Aubé, Christophe

2016-03-01

Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure. A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77). Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P radiofrequency failure. Failure rate was lower with the multipolar technique for tumors radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Coagulants modulate the hypocholesterolemic effect of tofu ...

African Journals Online (AJOL)

hope&shola

2006-02-02

Feb 2, 2006 ... The recent increase in soymilk and tofu (coagulated soymilk) consumption especially in western countries is due to the recognition of the health benefits of soy foods. The amount and the type of coagulated biomolecules (such as isoflavones) vary with the type of coagulant, and this will inevitable alter their ...

Contact activation of blood-plasma coagulation

Science.gov (United States)

Golas, Avantika

Surface engineering of biomaterials with improved hemocompatibility is an imperative, given the widespread global need for cardiovascular devices. Research summarized in this dissertation focuses on contact activation of FXII in buffer and blood plasma frequently referred to as autoactivation. The extant theory of contact activation imparts FXII autoactivation ability to negatively charged, hydrophilic surfaces. According to this theory, contact activation of plasma involves assembly of proteins comprising an "activation complex" on activating surfaces mediated by specific chemical interactions between complex proteins and the surface. This work has made key discoveries that significantly improve our core understanding of contact activation and unravel the existing paradigm of plasma coagulation. It is shown herein that contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension t°a=g° Iv costheta in dyne/cm, where g°Iv is water interfacial tension in dyne/cm and theta is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties --36 moderated by adsorption of plasma proteins unrelated to coagulation through an "adsorption-dilution" effect that blocks FXII contact with hydrophobic activator surfaces. The adsorption-dilution effect explains the apparent specificity for hydrophilic activators pursued by earlier investigators. Finally a comparison of FXII autoactivation in buffer, serum, protein cocktail, and plasma solutions is shown herein. Activation of blood plasma coagulation in vitro by contact with material surfaces is demonstrably dependent on plasma-volume-to-activator-surface-area ratio. However, activation of factor XII dissolved in buffer, protein cocktail, heat-denatured serum, and FXI deficient plasma does not

Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation.

Science.gov (United States)

Stiermaier, Thomas; Okon, Thomas; Fengler, Karl; Mueller, Ulrike; Hoellriegel, Robert; Schuler, Gerhard; Desch, Steffen; Lurz, Philipp

2016-06-12

Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients. A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (pmeasures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04. Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

Creation of a Tumor-Mimic Model Using a Muscle Paste for Radiofrequency Ablation of the Lung

International Nuclear Information System (INIS)

Kawai, T.; Kaminou, T.; Sugiura, K.; Hashimoto, M.; Ohuchi, Y.; Adachi, A.; Fujioka, S.; Ito, H.; Nakamura, K.; Ogawa, T.

2009-01-01

The purpose of this study was to develop an easily created tumor-mimic model and evaluate its efficacy for radiofrequency ablation (RFA) of the lung. The bilateral lungs of eight living adult swine were used. A tumor-mimic model was made by percutaneous injection of 1.0 ml muscle paste through the bone biopsy needle into the lung. An RFA probe was then inserted into the tumor mimics immediately after tumor creation. Ablation time, tissue impedance, and temperature were recorded. The tumor mimics and their coagulated regions were evaluated microscopically and macroscopically. The muscle paste was easily injected into the lung parenchyma through the bone biopsy needle and well visualized under fluoroscopy. In 10 of 12 sites the tumor mimics were oval shaped, localized, and homogeneous on gross specimens. Ten tumor mimics were successfully ablated, and four locations were ablated in the normal lung parenchyma as controls. In the tumor and normal lung parenchyma, ablation times were 8.9 ± 3.5 and 4.4 ± 1.6 min, respectively; tissue impedances at the start of ablation were 100.6 ± 16.6 and 145.8 ± 26.8 Ω, respectively; and temperatures at the end of ablation were 66.0 ± 7.9 and 57.5 ± 7.6 o C, respectively. The mean size of tumor mimics was 13.9 x 8.2 mm, and their coagulated area was 18.8 x 13.1 mm. In the lung parenchyma, the coagulated area was 15.3 x 12.0 mm. In conclusion, our tumor-mimic model using muscle paste can be easily and safely created and can be ablated using the ablation algorithm in the clinical setting.

Combined radiofrequency ablation and acetic acid-hypertonic saline solution instillation: an in vivo study of rabbit liver

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong-Min; Han, Joon-Koo; Kim, Se-Hyung; Choi, Byung-Ihn [Seoul National University, Seoul (Korea, Republic of); Kim, Young-Kon; Kim, Sang-Won [Chonbuk National University, Chonju (Korea, Republic of)

2004-03-15

We wanted to determine whether combined radiofrequency ablation (RFA) and acetic acid-hypertonic saline solution (AHS) instillation can increase the extent of thermally mediated coagulation in in vivo rabbit liver tissue. We also wished to determine the optimal concentration of the solution in order to maximize its effect on extent of the RFA-induced coagulation. Forty thermal ablation zones were produced in 40 rabbits by using a 17-gauge internally cooled electrode with a 1-cm active tip under ultrasound guidance. The rabbits were assigned to one of four groups: group A: RFA alone (n=10); group B: RFA with 50% AHS instillation (n=10); group C: RFA with 25% AHS instillation (n=10); group D: RFA with 15% AHS instillation (n=10). A range of acetic acid concentrations diluted in 36% NaCl to a total volume of 2 mL were instilled into the liver before RFA. The RF energy (30W) was applied for three minutes. After RFA, in each group, the maximum diameters to the thermal ablation zones in the gross specimens were compared. Technical success and the complication that arose were evaluated by CT and on the basis of autopsy findings. All procedures are technically successful. There were six procedure-related complications (6/40; 15%); two localized perihepatic hematomas and four chemical peritonitis. The incidence of chemical peritonitis was highest for group B with the 50% AHS solution instillation (30%). With instillation of 15% AHS solution, a marked decrease of tissue impedance (24.5 {+-} 15.6 {omega}) and an increase of current (250 mA) occurred as compared to RFA alone. With instillation of the solutions before RFA (group B, C and D). this produced a greater mean diameter of coagulation necrosis than the diameters for rabbits not instilled with the solution (group A) ({rho}<0.05). However, there was no significant difference between group B, C, and D. Combined AHS instillation and RFA can increase the dimension of coagulation necrosis in the liver with a single

Evaluation of the safety and efficacy of a monopolar nonablative radiofrequency device for the improvement of vulvo-vaginal laxity and urinary incontinence.

Science.gov (United States)

Lalji, Shelena; Lozanova, Paula

2017-06-01

Vaginal childbirth, natural process of aging, congenital factors, and surgical interventions are considered the main causes of vulvo-vaginal laxity driven by changes in collagen and elastin fibers. This causes a loss of strength and flexibility within the vaginal wall. As a result, women may experience lack of sensation and stress urinary incontinence (SUI)-the condition of involuntary loss of urine associated with activities that cause an increase in intra-abdominal pressure (eg, sneezing, coughing, and lifting). Both vaginal laxity and urinary incontinence significantly affect patients' quality of life (QoL). The aim of this study was to evaluate efficacy and safety of a noninvasive radiofrequency device when used to treat SUI and vulvo-vaginal laxity through its heating effect which stimulates collagen and elastin fibers. Twenty-seven women (average age 44.78±10.04 years) with indications of mild/moderate SUI as well as vulvo-vaginal laxity were treated with a monopolar radiofrequency device. The treatment course consisted of three once-a-week sessions. Each session included intravaginal treatment followed by treatment of labia majora and the perineum. Improvement in the SUI condition was evaluated by applying the International Consultation on Incontinence Questionnaire - Urinary Incontinence Short Form (ICIQ-UI SF). Data were collected at the baseline, after the last treatment and at 1-month follow-up visit. Vaginal laxity was assessed by subjective vulvo-vaginal laxity questionnaire (VVLQ). Data were collected before the 1st treatment and during the 1-month follow-up visit. Patient's satisfaction was recorded using a satisfaction questionnaire. Data were collected after the last treatment and at the 1-month follow-up visit. Any adverse events related to the treatments were monitored. On a scale of 0 to 5, the average frequency of urine leak improved from "2-3 times a week" (2.15±1.03 points prior to treatment) to "once a week" (1.00±0.78 points post

Coagulant recovery and reuse for drinking water treatment.

Science.gov (United States)

Keeley, James; Jarvis, Peter; Smith, Andrea D; Judd, Simon J

2016-01-01

Coagulant recovery and reuse from waterworks sludge has the potential to significantly reduce waste disposal and chemicals usage for water treatment. Drinking water regulations demand purification of recovered coagulant before they can be safely reused, due to the risk of disinfection by-product precursors being recovered from waterworks sludge alongside coagulant metals. While several full-scale separation technologies have proven effective for coagulant purification, none have matched virgin coagulant treatment performance. This study examines the individual and successive separation performance of several novel and existing ferric coagulant recovery purification technologies to attain virgin coagulant purity levels. The new suggested approach of alkali extraction of dissolved organic compounds (DOC) from waterworks sludge prior to acidic solubilisation of ferric coagulants provided the same 14:1 selectivity ratio (874 mg/L Fe vs. 61 mg/L DOC) to the more established size separation using ultrafiltration (1285 mg/L Fe vs. 91 mg/L DOC). Cation exchange Donnan membranes were also examined: while highly selective (2555 mg/L Fe vs. 29 mg/L DOC, 88:1 selectivity), the low pH of the recovered ferric solution impaired subsequent treatment performance. The application of powdered activated carbon (PAC) to ultrafiltration or alkali pre-treated sludge, dosed at 80 mg/mg DOC, reduced recovered ferric DOC contamination to water quality parameters. Several PAC-polished recovered coagulants provided the same or improved DOC and turbidity removal as virgin coagulant, as well as demonstrating the potential to reduce disinfection byproducts and regulated metals to levels comparable to that attained from virgin material. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pulse-dose radiofrequency treatment in pain management-initial experience.

Science.gov (United States)

Ojango, Christine; Raguso, Mario; Fiori, Roberto; Masala, Salvatore

2018-05-01

Radiofrequency procedures have been used for treating various chronic pain conditions for decades. These minimally invasive percutaneous treatments employ an alternating electrical current with oscillating radiofrequency wavelengths to eliminate or alter pain signals from the targeted site. The aim of the continuous radiofrequency procedure is to increase the temperature sufficiently to create an irreversible thermal lesion on nerve fibres and thus permanently interrupt pain signals. The pulsed radiofrequency procedure utilises short pulses of radiofrequency current with intervals of longer pauses to avert a temperature increase to the level of permanent tissue damage. The goal of these pulses is to alter the processing of pain signals, but to avoid relevant structural damage to nerve fibres, as seen in the continuous radiofrequency procedure. The pulse-dose radiofrequency procedure is a technical improvement of the pulsed radiofrequency technique in which the delivery mode of the current is adapted. During the pulse-dose radiofrequency procedure thermal damage is avoided. In addition, the amplitude and width of the consecutive pulses are kept the same. The method ensures that each delivered pulse keeps the same characteristics and therefore the dose is similar between patients. The current review outlines the pulse-dose radiofrequency procedure and presents our institution's chronic pain management studies.

Coagulation and Mental Disorders

Directory of Open Access Journals (Sweden)

Silvia Hoirisch-Clapauch

2014-10-01

Full Text Available The neurovascular unit is a key player in brain development, homeostasis, and pathology. Mental stress affects coagulation, while severe mental illnesses, such as recurrent depression and schizophrenia, are associated with an increased thrombotic risk and cardiovascular morbidity. Evidence indicates that the hemostatic system is involved to some extent in the pathogenesis, morbidity, and prognosis of a wide variety of psychiatric disorders. The current review focuses on emerging data linking coagulation and some psychiatric disorders.

Removal of silver nanoparticles by coagulation processes

International Nuclear Information System (INIS)

Sun, Qian; Li, Yan; Tang, Ting; Yuan, Zhihua; Yu, Chang-Ping

2013-01-01

Highlights: • This study investigated the removal of AgNP suspensions by four regular coagulants. • The optimal removal efficiencies for the four coagulants were achieved at pH 7.5. • The removal efficiency of AgNPs was affected by the natural water characteristics. • TEM and XRD showed that AgNPs or silver-containing NPs were adsorbed onto the flocs. -- Abstract: Commercial use of silver nanoparticles (AgNPs) will lead to a potential route for human exposure via potable water. Coagulation followed by sedimentation, as a conventional technique in the drinking water treatment facilities, may become an important barrier to prevent human from AgNP exposures. This study investigated the removal of AgNP suspensions by four regular coagulants. In the aluminum sulfate and ferric chloride coagulation systems, the water parameters slightly affected the AgNP removal. However, in the poly aluminum chloride and polyferric sulfate coagulation systems, the optimal removal efficiencies were achieved at pH 7.5, while higher or lower of pH could reduce the AgNP removal. Besides, the increasing natural organic matter (NOM) would reduce the AgNP removal, while Ca 2+ and suspended solids concentrations would also affect the AgNP removal. In addition, results from the transmission electron microscopy and X-ray diffraction showed AgNPs or silver-containing nanoparticles were adsorbed onto the flocs. Finally, natural water samples were used to validate AgNP removal by coagulation. This study suggests that in the case of release of AgNPs into the source water, the traditional water treatment process, coagulation/sedimentation, can remove AgNPs and minimize the silver ion concentration under the well-optimized conditions

Preliminary clinical evaluation of a noninvasive device for the measurement of coagulability in the elderly

Directory of Open Access Journals (Sweden)

Lerman Y

2011-08-01

Full Text Available Yaffa Lerman1, Moshe M Werber2, Ilya Fine2, Polina Kemelman11Department of Geriatrics, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 2Elfi-Tech Ltd, Rehovot, IsraelAbstract: The feasibility of the noninvasive assessment of blood ‘coagulability’ (the tendency to coagulate has been tested by using a novel device, the Thrombo-Monitor. It monitors, by using the principles of near infra-red (NIR dynamic light scattering, the tendency of blood to create clots. The Thrombo-Monitor observes the very initial changes of blood viscosity, which occurs due to the temporarily induced stasis of capillary blood of the finger. One hundred and fifteen patients aged >65 years (matched by age and sex participated in the study. Patients were initially divided into four groups based on the patient’s medical therapy. The study groups were: warfarin, enoxaparin, aspirin and/or clopidogrel, and a control group. The medications were given according to the patient’s comorbidities (eg, atrial fibrillation [AF], status post pulmonary embolism [S/p PE], status post cerebrovascular accident [S/p CVA]. The Thrombo-Monitor Index (TMI is a noninvasive index, derived on the basis of laboratory test results of international normalized ratio (INR and prothrombin time (PT values. For the group of patients who were treated only with warfarin, TMI was adjusted by using the jackknife statistical approach to create maximum correlation and linearity with INR and PT values that ranged from 1.1 to 5.0. For all warfarin patients (N = 35 the TMI was found to have a good correlation with INR and PT values (R2 = 0.64, P < 0.00001; mean TMI = 1.86 (SD = 0.91; mean INR and PT = 2.3 (SD = 0.91. The calibration curve thus generated was used to calculate the TMI for all other groups: aspirin group, mean TMI = 1.3 (SD = 0.14, N = 23, corresponding approximately to INR and PT values of 1.036; enoxaparin group (N = 24, mean TMI = 1.34 (SD

Time-of-Flight Positron Emission Tomography with Radiofrequency Phototube

International Nuclear Information System (INIS)

Margaryan, A.; Kakoyan, V.; Knyazyan, S.

2011-01-01

In this paper γ-detector, based on the radiofrequency (RF) phototube and recently developed fast and ultrafast scintillators, is considered for Time-of-Flight positron emission tomography applications. Timing characteristics of such a device has been investigated by means of a dedicated Monte Carlo code based on the single photon counting concept. Biexponential timing model for scintillators have been used. The calculations have shown that such a timing model is in a good agreement with recently measured data. The timing resolution of -detectors can be significantly improved by using the RF phototube. (authors)

Imaging of blood plasma coagulation at supported lipid membranes.

Science.gov (United States)

Faxälv, Lars; Hume, Jasmin; Kasemo, Bengt; Svedhem, Sofia

2011-12-15

The blood coagulation system relies on lipid membrane constituents to act as regulators of the coagulation process upon vascular trauma, and in particular the 2D configuration of the lipid membranes is known to efficiently catalyze enzymatic activity of blood coagulation factors. This work demonstrates a new application of a recently developed methodology to study blood coagulation at lipid membrane interfaces with the use of imaging technology. Lipid membranes with varied net charges were formed on silica supports by systematically using different combinations of lipids where neutral phosphocholine (PC) lipids were mixed with phospholipids having either positively charged ethylphosphocholine (EPC), or negatively charged phosphatidylserine (PS) headgroups. Coagulation imaging demonstrated that negatively charged SiO(2) and membrane surfaces exposing PS (obtained from liposomes containing 30% of PS) had coagulation times which were significantly shorter than those for plain PC membranes and EPC exposing membrane surfaces (obtained from liposomes containing 30% of EPC). Coagulation times decreased non-linearly with increasing negative surface charge for lipid membranes. A threshold value for shorter coagulation times was observed below a PS content of ∼6%. We conclude that the lipid membranes on solid support studied with the imaging setup as presented in this study offers a flexible and non-expensive solution for coagulation studies at biological membranes. It will be interesting to extend the present study towards examining coagulation on more complex lipid-based model systems. Copyright © 2011 Elsevier Inc. All rights reserved.

Endoscopic release of congenital muscular torticollis with radiofrequency in teenagers.

Science.gov (United States)

Wang, Jun-Liang; Qi, Wei; Liu, Yu-Jie

2018-05-03

Congenital muscular torticollis (CMT) is due to contracture of the sternocleidomastoid muscle which may cause activity limitations of the neck, tilt of the head, craniofacial asymmetry, and deformity of the skull. The authors present their experience of arthroscopic tight fibrous band release with radiofrequency in teenagers under local anesthesia and evaluate the clinical results. A total of 69 patients who underwent arthroscopic release of CMT with radiofrequency under local anesthesia by a single surgeon could participate in this study. Before operation, surface landmarks of sternocleidomastoid muscle, bone, and neurovascular structures were marked. Local infiltrating anesthesia of the surgical region was then performed. Through a working space created by blunt dissection, the arthroscopy and radiofrequency devices were introduced. Then, the clavicular and sternal heads of the sternocleidomastoid muscle were identified and gradually transected. The patients were followed up postoperatively with Cheng's scoring system. There were 31 male patients and 38 female patients. The mean age of the patients was 16.1 years. The mean length of follow-up in this series was 36.7 months (range, 28 to 67 months). During the operation, 62 patients (89.9%) had no pain, 6 patients (8.7%) felt mild pain, and only 1 patient (1.4%) regarded the procedure as very painful. At all follow-up periods, there were no repeat arthroscopies for any of these patients. At the final follow-up, the average rotation deficit improved from 22.5° to 4.1° postoperatively, and the average lateral bending deficit improved from 14.6° to 3.3° (p radiofrequency under local anesthesia provides surgeons with an alternative to traditional open techniques for the management of congenital muscular torticollis (CMT). Our date shows that this method is minimally invasive and provides good functional recovery with a lower risk of complications.

Effect of nano-scale curvature on the intrinsic blood coagulation system

Science.gov (United States)

Kushida, Takashi; Saha, Krishnendu; Subramani, Chandramouleeswaran; Nandwana, Vikas; Rotello, Vincent M.

2014-11-01

The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation `silent' surface, while nanoparticles with lower surface curvature show denaturation and concomitant coagulation.The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation `silent' surface, while nanoparticles with lower surface curvature show denaturation and concomitant coagulation. Electronic supplementary information (ESI) available: Physical properties and scanning electron micrographs (SEM) of silica NPs, intrinsic coagulation activity after 3 h. See DOI: 10.1039/c4nr04128c

Delayed Development of Pneumothorax After Pulmonary Radiofrequency Ablation

International Nuclear Information System (INIS)

Clasen, Stephan; Kettenbach, Joachim; Kosan, Bora; Aebert, Hermann; Schernthaner, Melanie; Kroeber, Stefan-Martin; Boemches, Andrea; Claussen, Claus D.; Pereira, Philippe L.

2009-01-01

Acute pneumothorax is a frequent complication after percutaneous pulmonary radiofrequency (RF) ablation. In this study we present three cases showing delayed development of pneumothorax after pulmonary RF ablation in 34 patients. Our purpose is to draw attention to this delayed complication and to propose a possible approach to avoid this major complication. These three cases occurred subsequent to 44 CT-guided pulmonary RF ablation procedures (6.8%) using either internally cooled or multitined expandable RF electrodes. In two patients, the pneumothorax, being initially absent at the end of the intervention, developed without symptoms. One of these patients required chest drain placement 32 h after RF ablation, and in the second patient therapy remained conservative. In the third patient, a slight pneumothorax at the end of the intervention gradually increased and led into tension pneumothorax 5 days after ablation procedure. Underlying bronchopleural fistula along the coagulated former electrode track was diagnosed in two patients. In conclusion, delayed development of pneumothorax after pulmonary RF ablation can occur and is probably due to underlying bronchopleural fistula, potentially leading to tension pneumothorax. Patients and interventionalists should be prepared for delayed onset of this complication, and extensive track ablation following pulmonary RF ablation should be avoided.

Characterization of tracked radiofrequency ablation in phantom

International Nuclear Information System (INIS)

Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L.

2007-01-01

In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4±0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA

Temperature-controlled irrigated tip radiofrequency catheter ablation

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, Adrian

1998-01-01

INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

Radiofrequency Ablation of Hepatic Cysts : Case Report

International Nuclear Information System (INIS)

Lee, Ye Ri; Kim, Pyo Nyun

2005-01-01

Radiofrequency ablation has been frequently performed on intra-hepatic solid tumor, namely, hepatocellular carcinoma, metastatic tumor and cholangio carcinoma, for take the cure. But, the reports of radiofrequency ablation for intrahepatic simple cysts are few. In vitro experiment of animal and in vivo treatment for intrahepatic cysts of human had been reported in rare cases. We report 4 cases of radiofrequency ablation for symptomatic intrahepatic cysts

Ablation of liver metastases by radiofrequency

International Nuclear Information System (INIS)

Baere, T. de

2012-01-01

Radiofrequency is a thermal ablative technique that is most often used percuteanously under image guidance. Thermal damage is obtained through frictional heating of a high frequency current. The maximal volume of destruction obtained in one radiofrequency delivery is around 4 cm and consequently, best indication for treatment are tumours below 3 cm. When compared, radiofrequency and surgical removal for tumours below 25 mm in diameter demonstrated a rate of incomplete resection/ablation of 6% and 7.3% respectively. Median survival after the first radiofrequency of a liver metastasis of CRC is reported to be 24 to 52 months with a 5 years overall survival of 18 to 44%. The median overall survival increases from 22 to 48 months depending on the use of radiofrequency ablation as rescue treatment after failure of others, or as a first line treatment. For patients with a single tumour, less than 4 cm, the survival rates at 1, 3, and 5 years are respectively 97%, 84% and 40%, with a median survival of 50 months. Follow-up imaging requires to use contrast-enhanced CT or MRI, looking for local recurrences evidenced by local foci of enhancement at the periphery of the ablation zone. (author)

47 CFR 1.1310 - Radiofrequency radiation exposure limits.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency radiation exposure limits. 1... Procedures Implementing the National Environmental Policy Act of 1969 § 1.1310 Radiofrequency radiation... exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except in the case of portable...

Radiofrequency assisted pancreaticoduodenectomy for palliative surgical resection of locally advanced pancreatic adenocarcinoma.

Science.gov (United States)

Kumar, Jayant; Reccia, Isabella; Sodergren, Mikael H; Kusano, Tomokazu; Zanellato, Artur; Pai, Madhava; Spalding, Duncan; Zacharoulis, Dimitris; Habib, Nagy

2018-03-20

Despite careful patient selection and preoperative investigations curative resection rate (R0) in pancreaticoduodenectomy ranges from 15% to 87%. Here we describe a new palliative approach for pancreaticoduodenectomy using a radiofrequency energy device to ablate tumor in situ in patients undergoing R1/R2 resections for locally advanced pancreatic ductal adenocarcinoma where vascular reconstruction was not feasible. There was neither postoperative mortality nor significant morbidity. Each time the ablation lasted less than 15 minutes. Following radiofrequency ablation it was observed that the tumor remnant attached to the vessel had shrunk significantly. In four patients this allowed easier separation and dissection of the ablated tumor from the adherent vessel leading to R1 resection. In the other two patients, the ablated tumor did not separate from vessel due to true tumor invasion and patients had an R2 resection. The ablated remnant part of the tumor was left in situ. Whenever pancreaticoduodenectomy with R0 resection cannot be achieved, this new palliative procedure could be considered in order to facilitate resection and enable maximum destruction in remnant tumors. Six patients with suspected tumor infiltration and where vascular reconstruction was not warranted underwent radiofrequency-assisted pancreaticoduodenectomy for locally advanced pancreatic ductal adenocarcinoma. Radiofrequency was applied across the tumor vertically 5-10 mm from the edge of the mesenteric and portal veins. Following ablation, the duodenum and the head of pancreas were removed after knife excision along the ablated line. The remaining ablated tissue was left in situ attached to the vessel.

Use of bipolar radiofrequency in parenchymal transection of the liver, pancreas and kidney.

Science.gov (United States)

Pai, Madhava; Spalding, Duncan; Jiao, Long; Habib, Nagy

2012-01-01

Intraoperative blood loss has been shown to be an important factor correlating with increased morbidity and mortality in oncological surgery. Despite technological advances in parenchymal transection devices, bleeding remains the single most important complication. To address this, we designed and developed a bipolar radiofrequency (RF) device, the Habib 4X (Angiodynamics, Inc., Queensbury, N.Y., USA), which was initially used specifically for liver resections. A search using Medline, Embase and Google™ Scholar was performed for the period January 2001 to August 2011. The following Mesh terms were used: 'bipolar radiofrequency', 'Habib 4X', 'laparoscopic', 'liver resection', 'partial nephrectomy' and 'distal pancreatectomy'. The references of the studies included were also reviewed. Series from our centre were excluded. There were seven series published, reporting a total of 188 liver resections [113 minor (Habib 4X) device over this period. The median blood loss reported ranged from 15 to 427 ml with a transfusion rate of 0-14% In addition, five series of partial nephrectomies were also identified, reporting a total of 149 (45 open and 104 laparoscopic) cases. Hilar clamping was not used in any of the cases, and the mean blood loss reported was 100-337 ml whilst the transfusion rate ranged from 0 to 7.1%. There was only one published series of distal pancreatectomies; these were laparoscopic and included 14 patients. This review of bipolar RF-assisted liver resections, partial nephrectomies and distal pancreatectomies reported in the literature to date shows that there are significant advantages in using this device in these types of operation. Copyright © 2012 S. Karger AG, Basel.

Predictive factors for beneficial application of high-frequency electromagnetics for tumour vaporization and coagulation in neurosurgery

Directory of Open Access Journals (Sweden)

Koerbel Andrei

2008-04-01

Full Text Available Abstract Objective To identify preoperative and intraoperative factors and conditions that predicts the beneficial application of a high-frequency electromagnetic field (EMF system for tumor vaporization and coagulation. Methods One hundred three subsequent patients with brain tumors were microsurgically treated using the EMF system in addition to the standard neurosurgical instrumentarium. A multivariate analysis was performed regarding the usefulness (ineffective/useful/very helpful/essential of the new technology for tumor vaporization and coagulation, with respect to tumor histology and location, tissue consistency and texture, patients' age and sex. Results The EMF system could be used effectively during tumor surgery in 83 cases with an essential contribution to the overall success in 14 cases. In the advanced category of effectiveness (very helpful/essential, there was a significant difference between hard and soft tissue consistency (50 of 66 cases vs. 3 of 37 cases. The coagulation function worked well (very helpful/essential for surface (73 of 103 cases and spot (46 of 103 cases coagulation when vessels with a diameter of less than one millimeter were involved. The light-weight bayonet hand piece and long malleable electrodes made the system especially suited for the resection of deep-seated lesions (34 of 52 cases compared to superficial tumors (19 of 50 cases. The EMF system was less effective than traditional electrosurgical devices in reducing soft glial tumors. Standard methods where also required for coagulation of larger vessels. Conclusion It is possible to identify factors and conditions that predict a beneficial application of high-frequency electromagnetics for tumor vaporization and coagulation. This allows focusing the use of this technology on selective indications.

Radiofrequency identification: exploiting an old technology for measuring nurse time and motion.

Science.gov (United States)

Jones, Terry L

2012-09-01

A national campaign is underway to increase the amount of time staff nurses spend at the bedside of hospitalized patients through redesign of the work environment. This kind of work redesign requires robust data depicting what nurses do and how they spend their time. Historically, these kinds of data have been difficult, costly, and time consuming to collect. Wireless capture of data on the movement of humans within the work environment (ie, time and motion) is now possible through radiofrequency identification technology. When small tracking devices the size of a quarter are affixed to their clothing, the movement of nurses throughout a patient care unit can be monitored. The duration and frequency of patient interaction are captured along with the duration of time spent in other locations of interest to include nurses' station, supply room, medication room, doctors' station, electronic documentation stations, family waiting rooms, and the hallway. Patterns of nurse movement and time allocation can be efficiently identified, and the effects of staffing practices, workflows, and unit layout evaluated. Integration of radiofrequency identification time and motion data with other databases enables nurse leaders to link nursing time to important cost and quality outcomes. Nurse leaders should explore the usefulness of radiofrequency identification technology in addressing data needs for nurse time and motion.

Comparison of Moringa stenopetala seed extract as a clean coagulant with Alum and Moringa stenopetala-Alum hybrid coagulant to remove direct dye from Textile Wastewater.

Science.gov (United States)

Dalvand, Arash; Gholibegloo, Elham; Ganjali, Mohammad Reza; Golchinpoor, Najmeh; Khazaei, Mohammad; Kamani, Hossein; Hosseini, Sara Sadat; Mahvi, Amir Hossein

2016-08-01

In this study, the efficiency of Moringa stenopetala seed extract was compared with alum and M. stenopetala-alum hybrid coagulant to remove Direct Red 23 azo dye from textile wastewater. The effects of parameters such as pH, coagulant dose, type of salt used for the extraction of coagulant and initial dye concentration on dye removal efficiency were investigated. Moreover, the existing functional groups on the structure of M. stenopetala coagulant (MSC) were determined by Fourier transform infrared spectroscopy, and the morphology of sludge produced by MSC, alum, and hybrid coagulant was characterized by scanning electron microscopy. Ninhydrin test was also used to determine the quantity of primary amines in the MSC and Moringa oleifera coagulant (MOC). According to the results, with increasing the coagulant dose and decreasing the initial dye concentration, dye removal efficiency has increased. The maximum dye removal of 98.5, 98.2, and 98.3 % were obtained by using 240, 120, and 80 mg/L MSC, alum and hybrid coagulant at pH 7, respectively. The results also showed MSC was much more effective than MOC for dye removal. The volume of sludge produced by MSC was one fourth and half of those produced by alum and hybrid coagulant, respectively. Based on the results, hybrid coagulant was the most efficient coagulant for direct dye removal from colored wastewater.

Experimental investigation on electrical characteristics and dose measurement of dielectric barrier discharge plasma device used for therapeutic application.

Science.gov (United States)

Shahbazi Rad, Zahra; Abbasi Davani, Fereydoun

2017-04-01

In this research, a Dielectric Barrier Discharge (DBD) plasma device operating in air has been made. The electrical characteristics of this device like instantaneous power, dissipated power, and discharge capacitance have been measured. Also, the effects of applied voltage on the dissipated power and discharge capacitance of the device have been investigated. The determination of electrical parameters is important in DBD plasma device used in living tissue treatment for choosing the proper treatment doses and preventing the destructive effects. The non-thermal atmospheric pressure DBD plasma source was applied for studying the acceleration of blood coagulation time, in vitro and wound healing time, in vivo. The citrated blood drops coagulated within 5 s treatment time by DBD plasma. The effects of plasma temperature and electric field on blood coagulation have been studied as an affirmation of the applicability of the constructed device. Also, the effect of constructed DBD plasma on wound healing acceleration has been investigated.

Saline-enhanced radiofrequency electrocoagulation in bovine liver

Energy Technology Data Exchange (ETDEWEB)

Shin, Hong Seop; Oh, Joo Hyeong; Yoon, Yup; Kim, Hyun Cheol; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Kim, Eui Jong [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

1997-08-01

To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III (p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed.

Saline-enhanced radiofrequency electrocoagulation in bovine liver

International Nuclear Information System (INIS)

Shin, Hong Seop; Oh, Joo Hyeong; Yoon, Yup; Kim, Hyun Cheol; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Kim, Eui Jong

1997-01-01

To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III (p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed

3.0 T MR diffusion weighted imaging in the evaluation of radio-frequency ablation of the liver VX2 tumors

International Nuclear Information System (INIS)

Liu Yubao; Liang Changhong; Wang Qiushi; Xie Shufei; Yu Yuanxin; Liu Zaiyi; Zhang Zhonglin

2010-01-01

exhibited intense enhancement on contrast-enhanced images. Areas of low to intermediate signal intensity within the lesion on T 2 WI corresponded to coagulation necrosis. The tumor tissue appeared as areas of peripheral nodularity, with intermediate to high signal intensity on T 2 -weighted images and DWI. The tumor specimen was gray, among the tumor tissue, there were hyperplastic vessels, and granulation tissue. When b value was 600 s/mm 2 , the ADC value of viable tumor (9 cases), necrosis (18 cases), granulation tissue (18 cases), normal liver tissue (18 cases) were (1.227±0.140) × 10 -3 , (0.702±0.050) × 10 -3 , (1.918±0.124) × 10 -3 , (1.739±0.044) × 10 -3 mm 2 /s, respectively, which were statistically significant (P 2 , the differences of ADC values among viable tumor, granulation tissue, necrosis, normal liver tissue were also statistically significant (P<0.01). Conclusion: The rabbit liver VX2 tumor models and 3.0 T MR DWI are important tools in the basic and clinical researches of radiofrequency ablation. (authors)

Image-guided radiofrequency ablation of renal cell carcinoma

International Nuclear Information System (INIS)

Boss, Andreas; Clasen, Stephan; Pereira, Philippe L.; Kuczyk, Markus; Schick, Fritz

2007-01-01

The incidence of renal cell carcinoma is rising with the increased number of incidental detection of small tumours. During the past few years, percutaneous imaging-guided radiofrequency ablation has evolved as a minimally invasive treatment of small unresectable renal tumours offering reduced patient morbidity and overall health care costs. In radiofrequency ablation, thermal energy is deposited into a targeted tumour by means of a radiofrequency applicator. In recent studies, radiofrequency ablation was shown to be an effective and safe modality for local destruction of renal cell carcinoma. Radiofrequency applicator navigation can be performed via ultrasound, computed tomography or magnetic resonance guidance; however, ultrasound seems less favourable because of the absence of monitoring capabilities during ablation. On-line monitoring of treatment outcome can only be performed with magnetic resonance imaging giving the possibility of eventual applicator repositioning to ablate visible residual tumour tissue. Long-term follow-up is crucial to assess completeness of tumour ablation. New developments in ablation technology and radiological equipment will further increase the indication field for radiofrequency ablation of renal cell carcinoma. Altogether, radiofrequency ablation seems to be a promising new modality for the minimally invasive treatment of renal cell carcinoma, which was demonstrated to exhibit high short-term effectiveness. (orig.)

Fractional ablative and nonablative radiofrequency for skin resurfacing and rejuvenation of Thai patients.

Science.gov (United States)

Thanasarnaksorn, Wilai; Siramangkhalanon, Vorapot; Duncan, Diane Irvine; Belenky, Inna

2018-04-01

Fractional radiofrequency (RF) technology is often the preferable skin resurfacing treatment, especially among Asian patients. Second generation fractional RF technology has exclusive capability to produce separate biological responses (ablation, coagulation, or a combination of both) with 3 distinguished penetration depth programs. The aim of this study was to evaluate the efficacy and safety of a fractional RF handpiece such as this, on the Thai population. Fifty-five Thai patients were treated with a fractional RF handpiece. The clinical assessment included a pain score, satisfaction survey, physician assessment, a combined patient and physician's assessment of skin condition, and clinical photographic assessments. The wound healing response was evaluated according to 5-time points: immediately after applying a pulse, post 24 hours, post 7 days, post 1 month and post 8 weeks. The obtained patient satisfaction score was "very satisfied" among 74% of the patients, post 3 sessions. Positive correlation was found between patient satisfaction and the physician's assessment. The skin condition assessment showed an increase from an average of 4.2 to 7.9. All treated symptoms improved after each treatment and the clinical outcome lasted at least up to 3-5 months. No significant adverse events were recorded. The in vivo prospective study showed a dose-related response in the deepness of the coagulation injury. In addition, there was evidence for a progressive healing process beginning shortly after exposure and completed within a week. This study clinically and histologically supports the efficacy of fractional RF handpiece in question with a high safety profile. © 2017 Wiley Periodicals, Inc.

Thermometric determination of cartilage matrix temperatures during thermal chondroplasty: comparison of bipolar and monopolar radiofrequency devices.

Science.gov (United States)

Edwards, Ryland B; Lu, Yan; Rodriguez, Edwin; Markel, Mark D

2002-04-01

To compare cartilage matrix temperatures between monopolar radiofrequency energy (mRFE) and bipolar RFE (bRFE) at 3 depths under the articular surface during thermal chondroplasty. We hypothesized that cartilage temperatures would be higher at all cartilage depths for the bRFE device than for the mRFE device. Randomized trial using bovine cartilage. Sixty osteochondral sections from the femoropatellar joint of 15 adult cattle were used for this study. Using a custom jig, fluoroptic thermometry probes were placed at one of the following depths under the articular surface: 200 microm, 500 microm, or 2,000 microm. RF treatment was performed either with fluid flow (F) (120 mL/min) or without fluid flow (NF) (n = 5/depth/RFE device/flow; total specimens, 60). Irrigation fluid temperature was room temperature (22 degrees C). Thermometry data were acquired at 4 Hz for 5 seconds with the RF probe off, for 20 seconds with the RF probe on, and then for 15 seconds with the RF probe off. During RF treatment, a 0.79-cm2 area (1.0-cm diameter) of the articular surface centered over the thermometry probe was treated in a paintbrush manner in noncontact (bRFE) or light contact (mRFE). Thermal chondroplasty with bRFE resulted in higher cartilage matrix temperatures compared with mRFE for all depths and regardless of fluid flow. Bipolar RFE resulted in temperatures of 95 degrees C to 100 degrees C at 200 microm and 500 microm under the surface, with temperatures of 75 degrees C to 78 degrees C at 2,000 microm. Fluid flow during bRFE application had no effect at 200 microm. Monopolar RFE resulted in temperatures of 61 degrees C to 68 degrees C at 200 microm, 54 degrees C to 70 degrees C at 500 microm under the surface, and 28 degrees C to 30 degrees C at 2,000 microm below the surface. A significant effect of fluid flow during mRFE application occurred at 200 microm (NF, 61 degrees C; F, 63 degrees C) and 500 microm (NF, 53 degrees C; F, 68 degrees C). In this study, we found

Polyferric sulphate: preparation, characterisation and application in coagulation experiments.

Science.gov (United States)

Zouboulis, A I; Moussas, P A; Vasilakou, F

2008-07-15

The process of coagulation is a core environmental protection technology, which is mainly used in the water or wastewater treatment facilities. Research is now focused on the development of inorganic pre-polymerised coagulants. A characteristic example is PFS (polyferric sulphate), a relatively new pre-polymerised inorganic coagulant with high cationic charge. In this paper, the role of major parameters, including temperature, types of chemical reagents, ratio r=[OH]/[Fe], rate of base addition in the preparation stages of PFS were investigated. Furthermore, the prepared PFS was characterised based on typical properties, such as the percentage of the polymerised iron present in the compound, z-potential, pH, etc. Moreover, dynamics of coagulation process were examined by means of the Photometric Dispersion Analyzer (PDA). Finally, the coagulation efficiency of PFS in treating kaolin suspension and biologically pre-treated wastewater was evaluated in comparison with the respective conventional coagulant agent. The results indicate that certain parameters, such as the r value, the rate of base addition and the duration and temperature of the polymerisation stage, significantly affected the properties of the PFS. Additionally, the prepared PFS polymerised coagulants exhibit a significantly better coagulation performance than the respective non-polymerised one, i.e. ferric sulphate.

Evaluation of coagulation factors and platelet function from an off-line modified ultrafiltration technique for post-cardiopulmonary bypass circuit blood recovery.

Science.gov (United States)

Beckmann, S; Lynn, P; Miller, S; Harris, R; DiMarco, R F; Ross, J E

2013-05-01

Modified ultrafiltration (MUF) is a technique that hemoconcentrates residual CPB circuit blood and the patient at the same time. Hemoconcentration and MUF are Class 1-A recommendations in the anesthesia and surgical blood conservation guidelines. This study evaluated the off-line MUF process of the Hemobag (HB, Global Blood Resources, Somers, CT, USA) to quantitate coagulation factor levels, platelet (PLT) count and function in one facility and cellular growth factor concentrations of the final product that were transfused to the patient in another facility In two cardiac surgery facilities, after decannulation, the extracorporeal circuit (ECC) blood from 22 patients undergoing cardiac surgery was processed with the HB device. In eleven patients from the first facility by the study design, blood samples for coagulation factor levels and PLT aggregation were drawn from the reservoir of the MUF device pre- and post-processing. The samples (n = 11) were sent to a reference laboratory where testing for prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), reptilase time, fibrinogen, clotting factors II, V, VII, VIII, IX, X, ADAMTS-13, protein C, protein S, antithrombin III, von Willebrand Factor (vWF), and platelet (PLT) aggregation were performed. A portion of the final concentrated HB blood samples (n = 5-10) from the second facility by design were evaluated for transforming and platelet-derived cellular growth factor concentrations. On average, approximately 800 - 2000 mls of whole blood were removed from the ECC post-CPB for processing in the HB device. After processing, there was, on the average, approximately 300 - 950 mls of concentrated whole blood salvaged for reinfusion. The PT and INR were significantly lower in the post-processing product compared to the pre-processing samples while the aPTT times were not significantly different. All coagulation factors and natural anti-coagulants were significantly

Electromagnetic induction imaging with a radio-frequency atomic magnetometer

Energy Technology Data Exchange (ETDEWEB)

Deans, Cameron; Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk; Hussain, Sarah; Renzoni, Ferruccio [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2016-03-07

We report on a compact, tunable, and scalable to large arrays imaging device, based on a radio-frequency optically pumped atomic magnetometer operating in magnetic induction tomography modality. Imaging of conductive objects is performed at room temperature, in an unshielded environment and without background subtraction. Conductivity maps of target objects exhibit not only excellent performance in terms of shape reconstruction but also demonstrate detection of sub-millimetric cracks and penetration of conductive barriers. The results presented here demonstrate the potential of a future generation of imaging instruments, which combine magnetic induction tomography and the unmatched performance of atomic magnetometers.

Coagulation activity in liver disease | Reza | Internet Journal of ...

African Journals Online (AJOL)

Patients with advanced hepatic failure may present with the entire spectrum of coagulation factor deficiencies. This study was designed to determine laboratory abnormalities in coagulation in chronic liver disease and the association of these abnormalities with the extent of chronic hepatitis and cirrhosis. Coagulation ...

Radiofrequency Ablation of Lung Malignancies: Where Do We Stand?

International Nuclear Information System (INIS)

Lencioni, Riccardo; Crocetti, Laura; Cioni, Roberto; Mussi, Alfredo; Fontanini, Gabriella; Ambrogi, Marcello; Franchini, Chiara; Cioni, Dania; Fanucchi, Olivia; Gemignani, Raffaello; Baldassarri, Rubia; Angeletti, Carlo Alberto; Bartolozzi, Carlo

2004-01-01

Percutaneous radiofrequency (RF) ablation is a minimally invasive technique used to treat solid tumors. Because of its ability to produce large volumes of coagulation necrosis in a controlled fashion, this technique has gained acceptance as a viable therapeutic option for unresectable liver malignancies. Recently, investigation has been focused on the clinical application of RF ablation in the treatment of lung malignancies. In theory, lung tumors are well suited to RF ablation because the surrounding air in adjacent normal parenchyma provides an insulating effect, thus facilitating energy concentration within the tumor tissue. Experimental studies in rabbits have confirmed that lung RF ablation can be safely and effectively performed via a percutaneous, transthoracic approach, and have prompted the start of clinical investigation. Pilot clinical studies have shown that RF ablation enables successful treatment of relatively small lung malignancies with a high rate of complete response and acceptable morbidity, and have suggested that the technique could represent a viable alternate or complementary treatment method for patients with non-small cell lung cancer or lung metastases of favorable histotypes who are not candidates for surgical resection. This article gives an overview of lung RF ablation, discussing experimental animal findings, rationale for clinical application, technique and methodology, clinical results, and complications

Ex vivo human bile duct radiofrequency ablation with a bipolar catheter.

Science.gov (United States)

Atar, Mustafa; Kadayifci, Abdurrahman; Daglilar, Ebubekir; Hagen, Catherine; Fernandez-Del Castillo, Carlos; Brugge, William R

2018-06-01

Management of the primary and secondary tumors of the bile ducts still remains as a major clinical challenge. Radiofrequency (RF) ablation (RFA) of these tumors is feasible but the effect of RF energy on the human common bile duct (CBD) and surrounding tissues has not been investigated. This pilot study aimed to determine the relationship between RF energy and the depth of ablation in the normal human CBD. The study was performed on fresh ex vivo human biliary-pancreatic tissue which had been resected for a pancreatic cyst or mass. The study was conducted within 15 min after resection. A bipolar Habib RFA catheter was placed into the middle of the intact CBD, and three different (5, 7, 10 W) power settings were applied over a 90-s period by an RF generator. Gross and histological examinations were performed. The depth of coagulation necrosis in CBD and the effect of RFA on CBD wall and surrounding pancreas tissue were determined by microscopic examination. The study included eight tissue samples. 5 W power was applied to three sites and RFA caused only focal epithelial necrosis limited to the CBD mucosa. 7 and 10 W were applied to five sites and coagulation necrosis occurred in all cases. Microscopically, necrosis was transmural, involved accessory bile duct glands, and extended to the surrounding pancreatic tissue in four of these cases. Macroscopically, RFA resulted in circumferential white-yellowish color change extending approximately 2 cm of the CBD. Bipolar RF energy application with 5 W resulted in limited ablation on CBD wall. However, 7 and 10 W generated tissue necrosis which extended through the CBD wall and into surrounding pancreas tissue. Endoscopic biliary RFA is an effective technique for local biliary tissue ablation but the use of high energy may injure surrounding tissue.

Coagulation and Adsorption Treatment of Printing Ink Wastewater

OpenAIRE

Klančnik, Maja

2014-01-01

The intention of the study was to improve the efficiency of total organic carbon (TOC) and colour removal from the wastewater samples polluted with flexographic printing ink following coagulation treatments with further adsorption onto activated carbons and ground orange peel. The treatment efficiencies were compared to those of further flocculation treatments and of coagulation and adsorption processes individually. Coagulation was a relatively effective single-treatment method, removing 99...

Effect of nano-scale curvature on the intrinsic blood coagulation system

Science.gov (United States)

Kushida, Takashi; Saha, Krishnendu; Subramani, Chandramouleeswaran; Nandwana, Vikas; Rotello, Vincent M.

2014-01-01

The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation ‘silent’ surface, while nanoparticles with lower surface curvature shows denaturation and concomitant coagulation. PMID:25341004

Radiofrequency initiation and radiofrequency sustainment of laser initiated seeded high pressure plasma

International Nuclear Information System (INIS)

Paller, Eric S.; Scharer, John E.; Akhtar, Kamran; Kelly, Kurt; Ding, Guowen

2001-01-01

We examine radiofrequency initiation of high pressure(1-70 Torr) inductive plasma discharges in argon, nitrogen, air and organic seed gas mixtures. Millimeter wave interferometry, optical emission and antenna wave impedance measurements for double half-turn helix and helical inductive antennas are used to interpret the rf/plasma coupling, measure the densities in the range of 10 12 cm -3 and analyze the ionization and excited states of the gas mixtures. We have also carried out 193 nm excimer laser initiation of an organic gas seed plasma which is sustained at higher pressures(150 Torr) by radiofrequency coupling at 2.8 kW power levels

Radiofrequency energy exposure from the Trilliant smart meter.

Science.gov (United States)

Foster, Kenneth R; Tell, Richard A

2013-08-01

This paper reviews radiofrequency (RF) field levels produced by electric utility meters equipped with RF transceivers (so-called Smart Meters), focusing on meters from one manufacturer (Trilliant, Redwood City, CA, USA, and Granby, QC, Canada). The RF transmission levels are summarized based on publicly available data submitted to the U.S. Federal Communications Commission supplemented by limited independent measurements. As with other Smart Meters, this meter incorporates a low powered radiofrequency transceiver used for a neighborhood mesh network, in the present case using ZigBee-compliant physical and medium access layers, operating in the 2.45 GHz unlicensed band but with a proprietary network architecture. Simple calculations based on a free space propagation model indicate that peak RF field intensities are in the range of 10 mW m or less at a distance of more than 1-2 m from the meters. However, the duty cycle of transmission from the meters is very low (meter that were consistent with data reported by the vendor to the U.S. Federal Communications Commission. Limited measurements conducted in two houses with the meters were unable to clearly distinguish emissions from the meters from the considerable electromagnetic clutter in the same frequency range from other sources, including Wi-Fi routers and, when it was activated, a microwave oven. These preliminary measurements disclosed the difficulties that would be encountered in characterizing the RF exposures from these meters in homes in the face of background signals from other household devices in the same frequency range. An appendix provides an introduction to Smart Meter technology. The RF transmitters in wireless-equipped Smart Meters operate at similar power levels and in similar frequency ranges as many other digital communications devices in common use, and their exposure levels are very far below U.S. and international exposure limits.

Treatment of waste water by coagulation and flocculation using biomaterials

Science.gov (United States)

Muruganandam, L.; Saravana Kumar, M. P.; Jena, Amarjit; Gulla, Sudiv; Godhwani, Bhagesh

2017-11-01

The present study deals with the determination of physical and chemical parameters in the treatment process of waste water by flocculation and coagulation processes using natural coagulants and assessing their feasibility for water treatment by comparing the performance with each other and with a synthetic coagulant. Initial studies were done on the synthetic waste water to determine the optimal pH and dosage, the activity of natural coagulant, followed by the real effluent from tannery waste. The raw tannery effluent was bluish-black in colour, mildly basic in nature, with high COD 4000mg/l and turbidity in the range 700NTU, was diluted and dosed with organic coagulants, AloeVera, MoringaOleifera and Cactus (O.ficus-indica). The study observed that coagulant Moringa Oleifera of 15 mg/L dose at 6 pH gave the best reduction efficiencies for major physicochemical parameters followed by Aloe Vera and Cactus under identical conditions. The study reveals that the untreated tannery effluents can be treated with environmental confirmative naturally occurring coagulants.

Coagulation chemistries for silica removal from cooling tower water.

Energy Technology Data Exchange (ETDEWEB)

Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

2010-02-01

The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

Comparison of the Performance of Corn Starch Coagulant Aid Accompany with Alum, Polyaluminum Chloride and Ferric Chloride Coagulants in Turbidity Removal from Water

Directory of Open Access Journals (Sweden)

Leila Mosleh

2014-09-01

Full Text Available Background: The most important process in water treatment plant is coagulation and flocculation. Regular chemical coagulant which used in Iran are aluminum sulfate (Alum and ferric chloride. Chemical coagulants have hazardous effect on human health and their cost is high for developing country. The purpose of this study was to evaluate the comparison of chemical coagulants accompany with corn starch as a coagulant aid, for the turbidity removal from water. Methods: This study was accomplished in pilot-scale with synthetic turbid water using clay. In this research, initial turbidity of 250 and 500 NTU was experimented. Chemical coagulant dose during the experiment was 1, 2 and 5 ppm and natural coagulant dose was 0, 0.1, 0.3, 0.5 and 0.7 ppm. Results: The results showed that maximum removal efficiency of turbidity in initial turbidity of 250 NTU belonged to poly aluminum chloride with 5 ppm dosage and corn starch with 0.7 ppm dosage which removed and reduced the initial turbidity to 98.48% and 3.73 NTU, respectively. Moreover, in initial turbidity of 500 NTU the maximum removal efficiency was 98.52% which belonged to ferric chloride and corn starch (5 and 0.7 ppm respectively and reduced the initial turbidity to 7.4 NTU. Conclusions: The results of this study showed that using natural coagulant aid reduce the chemical coagulant consumption, and also does not have significant effect on pH range and reduce the health risks. While huge amount of required polyelectrolytes for water treatment plant imported to the country and the production of corn starch in our country is high, it is hope that the results of this project can be used in industrial scale.

Coagulation profile in open and video-assisted thoracoscopic lobectomies

DEFF Research Database (Denmark)

Christensen, Thomas Decker; Vad, Henrik; Pedersen, Søren

2018-01-01

OBJECTIVES: Lung cancer patients are perceived to have a relatively high risk of venous thromboembolic events due to an activation of the coagulation system. In terms of activation of the coagulation system, the difference between video-assisted thoracoscopic surgery (VATS) and open lobectomies...... for primary lung cancer has not been investigated. The aim of this study was to compare the impact on the coagulation system in patients undergoing curative surgery for primary lung cancer by either VATS or open lobectomies. METHODS: In total, 62 patients diagnosed with primary lung cancer were allocated...... to either VATS (n = 32) or open lobectomies (n = 30). All patients received subcutaneous injections with dalteparin (Fragmin®) 5000 IE once daily. The coagulation was assessed pre- and intraoperatively, and the first 2 days postoperatively by standard coagulation blood tests, thromboelastometry (ROTEM...

Coagulation and inflammation

NARCIS (Netherlands)

van der Poll, T.

2001-01-01

Severe infection induces both activation of the coagulation system and multiple other inflammatory mediator cascades. This concise review summarizes the current knowledge of mechanisms that are considered to contribute to the procoagulant response to sepsis. Furthermore, evidence is discussed that

Hyperkalaemia after radiofrequency ablation of hepatocellular carcinoma

NARCIS (Netherlands)

Verhoevena, BH; Haagsma, EB; Appeltans, BMG; Slooff, MJH; de Jong, KP

Radiofrequency ablation of liver tumours is a useful therapy for otherwise unresectable tumours. The complication rate is said to be low. In this case report we describe hyperkalaemia after radiofrequency ablation of a hepatocellular carcinoma in a patient with end-stage renal insufficiency. (C)

Clinical efficacy and safety evaluation of a novel fractional unipolar radiofrequency device on facial tightening: A preliminary report.

Science.gov (United States)

Suh, Dong Hye; Byun, Eun Jung; Lee, Sang Jun; Song, Kye Yong; Kim, Hei Sung

2017-06-01

Previous studies have shown that radiofrequency (RF) energy is safe and effective for improving skin laxity. Unlike monopolar and bipolar devices, little has been studied with the unipolar hand piece. We sought to evaluate the safety and efficacy of a novel fractional unipolar RF device on facial tightening. This was a retrospective, single-center study of 14 subjects with age-related facial laxity who underwent five sessions of fractional unipolar RF at an interval of 2 weeks, and then followed-up for 3 months. Standardized photos were taken at baseline and at 3-months follow-up, and were assessed by two independent dermatologists using a 4-point scale (0=no improvement, 1=mild improvement, 2=moderate improvement, 3=significant improvement). Punch biopsies (2 mm) were performed and a questionnaire was used to evaluate the patient's satisfaction and the incidence of adverse reactions. Fourteen subjects with mild to moderate age-related facial laxity were included in the study. The mean age of the subjects was 49.7 years (range 32-80). 35.7% of the subjects showed significant improvement, 50% moderate improvement, and 14.3% slight improvement of facial laxity in their follow-up photos. About 85.7% of the patients replied that they were either greatly satisfied or satisfied with the results at 3-months follow-up. Skin biopsies revealed an increase in collagen in the dermis. None of the subjects experienced any serious adverse events during or after the procedure. Our findings suggest that fractional Unipolar RF can be safely performed on the face and is effective in skin tightening. It has a great advantage over other forms of RF by being entirely painless. © 2017 Wiley Periodicals, Inc.

Bio-responsive polymer hydrogels homeostatically regulate blood coagulation.

Science.gov (United States)

Maitz, Manfred F; Freudenberg, Uwe; Tsurkan, Mikhail V; Fischer, Marion; Beyrich, Theresa; Werner, Carsten

2013-01-01

Bio-responsive polymer architectures can empower medical therapies by engaging molecular feedback-response mechanisms resembling the homeostatic adaptation of living tissues to varying environmental constraints. Here we show that a blood coagulation-responsive hydrogel system can deliver heparin in amounts triggered by the environmental levels of thrombin, the key enzyme of the coagulation cascade, which--in turn--becomes inactivated due to released heparin. The bio-responsive hydrogel quantitatively quenches blood coagulation over several hours in the presence of pro-coagulant stimuli and during repeated incubation with fresh, non-anticoagulated blood. These features enable the introduced material to provide sustainable, autoregulated anticoagulation, addressing a key challenge of many medical therapies. Beyond that, the explored concept may facilitate the development of materials that allow the effective and controlled application of drugs and biomolecules.

Radio-frequency integrated-circuit engineering

CERN Document Server

Nguyen, Cam

2015-01-01

Radio-Frequency Integrated-Circuit Engineering addresses the theory, analysis and design of passive and active RFIC's using Si-based CMOS and Bi-CMOS technologies, and other non-silicon based technologies. The materials covered are self-contained and presented in such detail that allows readers with only undergraduate electrical engineering knowledge in EM, RF, and circuits to understand and design RFICs. Organized into sixteen chapters, blending analog and microwave engineering, Radio-Frequency Integrated-Circuit Engineering emphasizes the microwave engineering approach for RFICs. Provide

Postprandial triglycerides and blood coagulation.

Science.gov (United States)

Silveira, A

2001-01-01

Most of our lifetime we spend in the postprandial state. Postprandial triglyceridemia may represent a procoagulant state involving disturbances of both blood coagulation and fibrinolysis, in particular due to elevation of the plasma levels of activated factor VII (VIIa) and plasminogen activator inhibitor (PAI-1). Therefore, disturbances of the hemostatic system might, at least partly, account for by the link between hypertriglyceridemia and coronary heart disease (CHD). Factor VIIa is the first enzyme of the blood coagulation system and serves a priming function for triggering of the clotting cascade. The coagulant activity of factor VII (VIIc, total activity of factor VII in plasma) was identified as an independent predictor of myocardial infarction in initially healthy middle-aged men, and particularly of fatal coronary events, and both serum cholesterol and triglyceride concentrations correlated positively with the VIIc level. Addition of fat to diet has been consistently shown to cause a rapid conversion of the factor VII zymogen into its active form (VIIa) whereas the concentration of total protein is unaffected. Postprandial activation of factor VII is dependent on lipolytic activity and it is mainly supported by large triglyceride-rich lipoprotein of the VLDL class. Studies in vivo with specific coagulation factor-deficient patients indicate that factor IX is essential for the postprandial activation of factor VII. The basal generation of thrombin seems to be unaffected by increased plasma levels of VIIa. However, since VIIa-tissue factor complex is responsible for the initiation of the coagulation cascade, increased generation of VIIa in the postprandial state would increase the potential for thrombin production in the event of plaque rupture. Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of the plasminogen activators in the circulation and thereby the principal inhibitor of the fibrinolytic system. Postprandial

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

[Analysis and management of postoperative hemorrhage in surgery of obstructive sleep apnea hypopnea syndrome in children using plasma-mediated radio-frequency ablation at low temperature].

Science.gov (United States)

Wang, Jun; Chen, Jie; Yang, Jun

2013-09-01

To analyze retrospectively cause, prevention and management of postoperative hemorrhage in surgery of obstructive sleep apnea hypopnea syndrome (OSAHS) in children using plasma-mediated radio-frequency (pmRF) ablation at low temperature. Tonsil and adenoid ablation were carried out in 4028 cases diagnosed with OSAHS, using ENTColator lI plasma system of Arthocare company under general anesthesia. Postoperative hemorrhage occurred in 37 cases of 4028 cases, among which 1 case occurred after tonsil ablation and other 36 cases occurred after adenoid ablation. Primary hemorrhage was in 7 cases, while secondary hemorrhage in other 30 cases. Cessation of bleeding was achieved by using different methods of hemostasis in all cases. Tonsil and adenoid ablation were performed by pmRF at low temperature with advantages of less trauma, less bleeding. However, postoperative hemorrhage might occur in a few cases (accounting for 0.92%). Postoperative hemorrhage in these patients was related with preoperatively incomplete control of inflammation of tonsil or adenoid, surgeon's experience, intraoperatively incomplete hemostasis, postoperative crying and restlessness, eating improperly in two weeks after surgery, coagulation factor deficiency. In case of postoperative hemorrhage, good outcome could be achieved by management of compression, pmRF at low temperature, bipolar coagulation.

Potential Use of Polyaluminium Chloride and Tobacco Leaf as Coagulant and Coagulant Aid in Post-Treatment of Landfill Leachate

Directory of Open Access Journals (Sweden)

Nurfarahim Rusdizal

2015-12-01

Full Text Available A study was conducted to treat stabilized leachate by applying polyaluminium chloride (PAC and tobacco leaf extract as a coagulant and coagulant aid. Experimental results indicated that the tobacco leaves were positively charged. The removal rate of the chemical oxygen demand, using 1500 mg/L PAC as a sole coagulant, was approximately 63% and increased to 91% when 1000 mg/L PAC was mixed with 1000 mg/L tobacco leaf. Additionally, 1500 mg/L PAC with 250 - 1000 mg/L tobacco leaf and 54% ammoniacal nitrogen was removed, compared with only 46% reduction using 1500 mg/L with only 46% reduction.

Implementation of a microcontroller-based semi-automatic coagulator.

Science.gov (United States)

Chan, K; Kirumira, A; Elkateeb, A

2001-01-01

The coagulator is an instrument used in hospitals to detect clot formation as a function of time. Generally, these coagulators are very expensive and therefore not affordable by a doctors' office and small clinics. The objective of this project is to design and implement a low cost semi-automatic coagulator (SAC) prototype. The SAC is capable of assaying up to 12 samples and can perform the following tests: prothrombin time (PT), activated partial thromboplastin time (APTT), and PT/APTT combination. The prototype has been tested successfully.

Evaluation of the In Vivo Efficiency and Safety of Hepatic Radiofrequency Ablation Using a 15-G Octopus® in Pig Liver

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun Sun [Department of Radiology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, Jeong Min [Department of Radiology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Kim, Kyung Won [Department of Radiology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, In Joon [National Cancer Center, Seoul 410-769 (Korea, Republic of); Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of)

2013-07-01

To determine in vivo efficacy of radiofrequency ablation (RFA) in porcine liver by using 15-gauge Octopus® (15-G Octopus®) electrodes to create a large coagulation. A total of 18 coagulations were created by using a 180-W generator and 15-G Octopus® electrodes during laparotomy, performed in 14 pigs. Coagulation necrosis was created in the pig livers by the use of one of three RFA protocols: 1) group A, monopolar RFA using a 15-G Octopus® electrode with a 5-mm inter-electrode distance (n = 4); 2) group B, monopolar RFA using a 15-G Octopus® electrode with a 10-mm inter-electrode distance (n = 6); and 3) group C, switching monopolar RFA using two 15-G Octopus® electrodes (n = 8). The energy efficiency, shape, maximum and minimum diameters (Dmx and Dmi), and the volume of the coagulation volume were measured in each group. The Summary statistics were obtained and Mann-Whitney test was were performed. The mean ablated volume of each group was 49.23 cm{sup 3} in A, 64.11 cm{sup 3} in B, and 72.35 cm{sup 3} in C. The mean Dmx and Dmi values were 5.68 cm and 4.58 cm in A and 5.97 cm and 4.97 cm in B, respectively. In group C, the mean diameters of Dmx and Dmi were 6.80 cm and 5.11 cm, respectively. The mean ratios of Dmi/Dmx were 1.25, 1.20, and 1.35 in groups A, B, and C, respectively. There was one animal death during the RFA procedure, the cause of which could not be subsequently determined. However, there were no other significant, procedure-related complications during the seven-hour-delayed CT scans. RFA procedures using 15-G Octopus® electrodes are useful and safe for creating a large ablation in a single electrode model as well as in the multiple electrodes model.

Evaluation of the In Vivo Efficiency and Safety of Hepatic Radiofrequency Ablation Using a 15-G Octopus® in Pig Liver

International Nuclear Information System (INIS)

Lee, Eun Sun; Lee, Jeong Min; Kim, Kyung Won; Lee, In Joon; Han, Joon Koo; Choi, Byung Ihn

2013-01-01

To determine in vivo efficacy of radiofrequency ablation (RFA) in porcine liver by using 15-gauge Octopus® (15-G Octopus®) electrodes to create a large coagulation. A total of 18 coagulations were created by using a 180-W generator and 15-G Octopus® electrodes during laparotomy, performed in 14 pigs. Coagulation necrosis was created in the pig livers by the use of one of three RFA protocols: 1) group A, monopolar RFA using a 15-G Octopus® electrode with a 5-mm inter-electrode distance (n = 4); 2) group B, monopolar RFA using a 15-G Octopus® electrode with a 10-mm inter-electrode distance (n = 6); and 3) group C, switching monopolar RFA using two 15-G Octopus® electrodes (n = 8). The energy efficiency, shape, maximum and minimum diameters (Dmx and Dmi), and the volume of the coagulation volume were measured in each group. The Summary statistics were obtained and Mann-Whitney test was were performed. The mean ablated volume of each group was 49.23 cm 3 in A, 64.11 cm 3 in B, and 72.35 cm 3 in C. The mean Dmx and Dmi values were 5.68 cm and 4.58 cm in A and 5.97 cm and 4.97 cm in B, respectively. In group C, the mean diameters of Dmx and Dmi were 6.80 cm and 5.11 cm, respectively. The mean ratios of Dmi/Dmx were 1.25, 1.20, and 1.35 in groups A, B, and C, respectively. There was one animal death during the RFA procedure, the cause of which could not be subsequently determined. However, there were no other significant, procedure-related complications during the seven-hour-delayed CT scans. RFA procedures using 15-G Octopus® electrodes are useful and safe for creating a large ablation in a single electrode model as well as in the multiple electrodes model

Coagulation mechanism of salt solution-extracted active component in Moringa oleifera seeds.

Science.gov (United States)

Okuda, T; Baes, A U; Nishijima, W; Okada, M

2001-03-01

This study focuses on the coagulation mechanism by the purified coagulant solution (MOC-SC-PC) with the coagulation active component extracted from M. oleifera seeds using salt solution. The addition of MOC-SC-PC tap water formed insoluble matters. This formation was responsible for kaolin coagulation. On the other hand, insoluble matters were not formed when the MOC-SC-PC was added into distilled water. The formation was affected by Ca2+ or other bivalent cations which may connect each molecule of the active coagulation component in MOC-SC-PC and form a net-like structure. The coagulation mechanism of MOC-SC-PC seemed to be an enmeshment of Kaolin by the insoluble matters with the net-like structure. In case of Ca2+ ion (bivalent cations), at least 0.2 mM was necessary for coagulation at 0.3 mgC l-1 dose of MOC-SC-PC. Other coagulation mechanisms like compression of double layer, interparticle bridging or charge neutralization were not responsible for the coagulation by MOC-SC-PC.

The efficacy of two electrodes radiofrequency technique: comparison study using a cadaveric interspinous ligament and temperature measurement using egg white.

Science.gov (United States)

Lee, Chang-Hyung; Derby, Richard; Choi, Hyun-Seok; Lee, Sang-Heon; Kim, Se Hoon; Kang, Yoon Kyu

2010-01-01

One technique in radiofrequency neurotomies uses 2 electrodes that are simultaneously placed to lie parallel to one another. Comparing lesions on cadaveric interspinous ligament tissue and measuring the temperature change in egg white allows us to accurately measure quantitatively the area of the lesion. Fresh cadaver spinal tissue and egg white tissue were used. A series of samples were prepared with the electrodes placed 1 to 7 mm apart. Using radiofrequency, the needle electrodes were heated in sequential or simultaneous order and the distance of the escaped lesion area and temperature were measured. Samples of cadaver interspinous ligament showed sequential heating of the needles limits the placement of the needle electrodes up to 2 mm apart from each other and up to 4 mm apart when heated simultaneously. The temperature at the escaped lesion area decreased according to the distance for egg white. There was a significant difference in temperature at the escaped lesion area up to 6 mm apart and the temperature was above 50 degrees celsius up to 5 mm in simultaneous lesion and 3 mm in the sequential lesion. The limitations of this study include cadaveric experimentation and use of intraspinous ligament rather than medial branch of the dorsal ramus which is difficult to identify. Heating the 2 electrodes simultaneously appears to coagulate a wider area and potentially produce better results in less time.

Infrared coagulation: a new treatment for hemorrhoids

International Nuclear Information System (INIS)

Leicester, R.J.; Nicholls, R.J.; Mann, C.V.

1981-01-01

Many methods, which have effectively reduced the number of patients requiring hospital admission, have been described for the outpatient treatment of hemorrhoids. However, complications have been reported, and the methods are often associated with unpleasant side effects. In 1977 Neiger et al. described a new method that used infrared coagulation, which produced minimal side effects. The authors have conducted a prospective, randomized trial to evaluate infrared coagulation compared with more traditional methods of treatment. The authors' results show that it may be more effective than injection sclerotherapy in treating non-prolapsing hemorrhoids and that it compares favorably with rubber band ligation in most prolapsing hemorrhoids. No complications occurred, and significantly fewer patients experienced pain after infrared coagulation

Intraventricular hemorrhage in preterm infants: coagulation perspectives.

Science.gov (United States)

Kuperman, Amir A; Kenet, Gili; Papadakis, Emmanuel; Brenner, Benjamin

2011-10-01

It has long been considered that a severe coagulation deficiency in premature newborns could be a major contributing factor in the occurrence of intraventricular hemorrhage (IVH). High-grade IVH has also been shown to coincide with severe derangement of coagulation in extremely low birth weight infants. This review focuses on the relevance of the physiologically developing immature hemostatic system to IVH, and the potential benefit of agents affecting hemostasis for IVH therapy or prevention in preterm infants. The findings of small, open-label interventional studies on the effect of ethamsylate, vitamin K, fresh frozen plasma, recombinant activated factor VII, and prothrombin complex concentrate on the premature coagulation system will be reviewed. © Thieme Medical Publishers.

The Coagulant Type Influence on Removal Efficiency of 5- and 6-Ring Pahs During Water Coagulation Process

Directory of Open Access Journals (Sweden)

Nowacka Anna

2014-12-01

Full Text Available The article presents results on investigation of the removal efficiency of selected 5- and 6-ring polycyclic aromatic hydrocarbons (benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[g,h,i]perylene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene from water during coagulation and sedimentation process. Two pre-hydrolyzed aluminum coagulants: PAX XL 19H and FLOKOR 105V were chosen for research. Process was carried out at optimum process parameters: rapid-mixing - 3 min at the rotational speed of 200 rpm, slow mixing - 10 min at 30 rpm, sedimentation - 60 min. The removal effectiveness was dependant on coagulant type and its composition. Better results in the removal of 5-and 6-ring PAHs were obtained after application of FLOKOR 105V (lower aluminum content than after using PAX XL 19H.

Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

Energy Technology Data Exchange (ETDEWEB)

Park, Seung Hee; Yun, Chung Bang [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Inman, Daniel J. [Virginia Polytechnic Institute and State University, Virginia (United States)

2007-06-15

This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

International Nuclear Information System (INIS)

Park, Seung Hee; Yun, Chung Bang; Inman, Daniel J.

2007-01-01

This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

Optimum coagulant forecasting by modeling jar test experiments using ANNs

Science.gov (United States)

Haghiri, Sadaf; Daghighi, Amin; Moharramzadeh, Sina

2018-01-01

Currently, the proper utilization of water treatment plants and optimizing their use is of particular importance. Coagulation and flocculation in water treatment are the common ways through which the use of coagulants leads to instability of particles and the formation of larger and heavier particles, resulting in improvement of sedimentation and filtration processes. Determination of the optimum dose of such a coagulant is of particular significance. A high dose, in addition to adding costs, can cause the sediment to remain in the filtrate, a dangerous condition according to the standards, while a sub-adequate dose of coagulants can result in the reducing the required quality and acceptable performance of the coagulation process. Although jar tests are used for testing coagulants, such experiments face many constraints with respect to evaluating the results produced by sudden changes in input water because of their significant costs, long time requirements, and complex relationships among the many factors (turbidity, temperature, pH, alkalinity, etc.) that can influence the efficiency of coagulant and test results. Modeling can be used to overcome these limitations; in this research study, an artificial neural network (ANN) multi-layer perceptron (MLP) with one hidden layer has been used for modeling the jar test to determine the dosage level of used coagulant in water treatment processes. The data contained in this research have been obtained from the drinking water treatment plant located in Ardabil province in Iran. To evaluate the performance of the model, the mean squared error (MSE) and correlation coefficient (R2) parameters have been used. The obtained values are within an acceptable range that demonstrates the high accuracy of the models with respect to the estimation of water-quality characteristics and the optimal dosages of coagulants; so using these models will allow operators to not only reduce costs and time taken to perform experimental jar tests

Disseminated intravascular coagulation in meningococcal sepsis. Case 7

NARCIS (Netherlands)

Zeerleder, S.; Zürcher Zenklusen, R.; Hack, C. E.; Wuillemin, W. A.

2003-01-01

We report on a man (age: 49 years), who died from severe meningococcal sepsis with disseminated intravascular coagulation (DIC), multiple organ dysfunction syndrome and extended skin necrosis. We discuss in detail the pathophysiology of the activation of coagulation and fibrinolysis during sepsis.

Interplay between coagulation and vascular inflammation in sickle cell disease

Science.gov (United States)

Sparkenbaugh, Erica; Pawlinski, Rafal

2013-01-01

Sickle cell disease is the most common inherited hematologic disorder that leads to the irreversible damage of multiple organs. Although sickling of red blood cells and vaso-occlusion are central to the pathophysiology of sickle cell disease the importance of hemolytic anemia and vasculopathy has been recently recognized. Hypercoagulation state is another prominent feature of sickle cell disease and is mediated by activation of both intrinsic and extrinsic coagulation pathways. Growing evidence demonstrates that coagulation may not only contribute to the thrombotic complications, but also to vascular inflammation associated with this disease. This article summarizes the role of vascular inflammation and coagulation activation, discusses potential mechanisms responsible for activation of coagulation and reviews recent data demonstrating the crosstalk between coagulation and vascular inflammation in sickle cell disease. PMID:23593937

Colloids removal from water resources using natural coagulant: Acacia auriculiformis

Science.gov (United States)

Abdullah, M.; Roslan, A.; Kamarulzaman, M. F. H.; Erat, M. M.

2017-09-01

All waters, especially surface waters contain dissolved, suspended particles and/or inorganic matter, as well as several biological organisms, such as bacteria, algae or viruses. This material must be removed because it can affect the water quality that can cause turbidity and colour. The objective of this study is to develop water treatment process from Seri Alam (Johor, Malaysia) lake water resources by using natural coagulant Acacia auriculiformis pods through a jar test experiment. Jar test is designed to show the effectiveness of the water treatment. This process is a laboratory procedure that will simulate coagulation/flocculation with several parameters selected namely contact time, coagulant dosage and agitation speed. The most optimum percentage of colloids removal for each parameter is determined at 0.2 g, 90 min and 80 rpm. FESEM (Field-emission Scanning Electron Microscope) observed the small structures of final floc particles for optimum parameter in this study to show that the colloids coagulated the coagulant. All result showed that the Acacia auriculiformis pods can be a very efficient coagulant in removing colloids from water.

Tissue Factor Coagulant Activity is Regulated by the Plasma Membrane Microenvironment.

Science.gov (United States)

Yu, Yuanjie; Böing, Anita N; Hau, Chi M; Hajji, Najat; Ruf, Wolfram; Sturk, Auguste; Nieuwland, Rienk

2018-06-01

 Tissue factor (TF) can be present in a non-coagulant and coagulant form. Whether the coagulant activity is affected by the plasma membrane microenvironment is unexplored.  This article studies the presence and coagulant activity of human TF in plasma membrane micro-domains.  Plasma membranes were isolated from human MIA PaCa2 cells, MDA-MB-231 cells and human vascular smooth muscle cells by Percoll gradient ultracentrifugation after cell disruption. Plasma membranes were fractionated by OptiPrep gradient ultracentrifugation, and the presence of TF, flotillin, caveolin, clathrin, protein disulphide isomerase (PDI), TF pathway inhibitor (TFPI) and phosphatidylserine (PS) were determined.  Plasma membranes contain two detergent-resistant membrane (DRM) compartments differing in density and biochemical composition. High-density DRMs (DRM-H) have a density ( ρ ) of 1.15 to 1.20 g/mL and contain clathrin, whereas low-density DRMs (DRM-L) have a density between 1.09 and 1.13 g/mL and do not contain clathrin. Both DRMs contain TF, flotillin and caveolin. PDI is detectable in DRM-H, TFPI is not detectable in either DMR-H or DRM-L and PS is detectable in DRM-L. The DRM-H-associated TF (> 95% of the TF antigen) lacks detectable coagulant activity, whereas the DRM-L-associated TF triggers coagulation. This coagulant activity is inhibited by lactadherin and thus PS-dependent, but seemed insensitive to 16F16, an inhibitor of PDI.  Non-coagulant and coagulant TF are present within different types of DRMs in the plasma membrane, and the composition of these DRMs may affect the TF coagulant activity. Schattauer GmbH Stuttgart.

Correlation between thromboelastography and traditional coagulation test parameters in hospitalized dogs

Directory of Open Access Journals (Sweden)

Rubanick JV

2017-02-01

Full Text Available Jean V Rubanick, Medora B Pashmakova, Micah A Bishop, James W Barr Department of Veterinary Small Animal Clinical Sciences, Texas A&M University, College Station, TX, USA Abstract: A hospital-based, prospective cross-sectional study was used to compare kaolin-activated thromboelastography (TEG parameters with traditional coagulation tests in 29 hospitalized dogs. Cases were included if the attending clinician requested coagulation testing. Blood was obtained from each dog and coagulation (prothrombin time, partial thromboplastin time, antithrombin activity, d-dimer concentration, and fibrinogen concentration and TEG analyses were performed. Hematocrit (Hct was also measured. Traditional coagulation results were evaluated for correlation with those from kaolin-activated TEG. Spearman’s correlation was used to calculate correlation coefficients. Fibrinogen was positively correlated with maximum amplitude (Pearson r=0.72, P<0.001 and global clot strength (Pearson r=0.72, P<0.001. There was no correlation between any of the remaining coagulation variables, TEG parameters, or Hct. Results of kaolin-activated TEG and traditional coagulation tests are not interchangeable means of monitoring coagulation derangements in this intensive care unit patient population. Determination of a true outcome measure is necessary to establish TEG’s clinical relevance to veterinary medicine. Keywords: TEG, thromboelastography, coagulation, hemostasis

Fractionated bipolar radiofrequency and bipolar radiofrequency potentiated by infrared light for treating striae: A prospective randomized, comparative trial with objective evaluation.

Science.gov (United States)

Harmelin, Yona; Boineau, Dominique; Cardot-Leccia, Nathalie; Fontas, Eric; Bahadoran, Philippe; Becker, Anne-Lise; Montaudié, Henri; Castela, Emeline; Perrin, Christophe; Lacour, Jean-Philippe; Passeron, Thierry

2016-03-01

Very few treatments for striae are based on prospective randomized trials. The objective of this study was to assess the efficacy of bipolar fractional radiofrequency and bipolar radiofrequency potentiated with infrared light, alone or combined, for treating abdominal stretch marks. Bicentric prospective interventional randomized controlled trial in the department of Dermatology of University Hospital of Nice and Aesthetics Laser Center of Bordeaux, France. Men and women of age 18 years or above, who presented for the treatment of mature or immature abdominal striae were included. The patients' abdomens were divided into four equal quadrants. Bipolar radiofrequency potentiated with infrared light and fractional bipolar radiofrequency were applied, alone or combined, and compared to the remaining untreated quadrant. The main criterion of evaluation was the measurement of depth of striae, using 3D photography at 6 months follow-up. A global assessment was also rated by the physician performing the treatment and by the patients. Histological analysis and confocal laser microscopy were additionally performed. A total of 22 patients were enrolled, and 384 striae were measured. In per protocol analysis mean striae depth was decreased by 21.64%, observed at 6 months follow-up with the combined approach, compared to an increase of 1.73% in the control group (P radiofrequency, combined with bipolar radiofrequency potentiated by infrared light, is an effective treatment of both immature and mature striae of the abdomen. © 2016 Wiley Periodicals, Inc.

Enhanced Coagulation-Flocculation Performance of Iron-Based Coagulants: Effects of PO4(3-) and SiO3(2-) Modifiers.

Science.gov (United States)

Chen, Wei; Zheng, Huaili; Teng, Houkai; Wang, Yili; Zhang, Yuxin; Zhao, Chuanliang; Liao, Yong

2015-01-01

PO4(3-) and SiO3(2-) are often used as modifier to improve stability and aggregating ability of the iron-base coagulants, however, there are few reports about their detailed comparison between the coagulation performance and mechanisms. In this study, three coagulants--polyferric phosphoric sulfate (PFPS), polysilicon ferric sulfate (PFSS), and polyferric sulfate (PFS) were synthesized; their structure and morphology were characterized by Fourier transformed infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Scanning electron microscope (SEM). Alkali titration and Ferron species analysis were employed to investigate the hydrolysis performance and species distribution. Jar test was conducted to measure their coagulation behaviors at different dosage, pH, and temperatures in which the flocs properties were measured. The results showed that a number of new compounds were formed due to the presence of PO4(3-) and SiO3(2-). Moreover, PFPS and PFSS had similar level in Fea as well as Feb. Among them, PFPS produced more multi-core iron atoms polymer and content of Feb, and the formed flocs were larger and denser. It exhibited superior coagulation performance in terms of turbidity reduction, UV254 removal and residual ferric concentration. Jar test and floc breakage/regrowth experiments indicated other than charge neutrality, the dominated mechanism involved in PFSS was the adsorption between polysilicic acid and solution particle, while PFPS was sweeping, entrapment/adsorption resulting from larger polymer colloid of Fe-P chemistry bond.

Enhanced Coagulation-Flocculation Performance of Iron-Based Coagulants: Effects of PO4(3- and SiO3(2- Modifiers.

Directory of Open Access Journals (Sweden)

Wei Chen

Full Text Available PO4(3- and SiO3(2- are often used as modifier to improve stability and aggregating ability of the iron-base coagulants, however, there are few reports about their detailed comparison between the coagulation performance and mechanisms. In this study, three coagulants--polyferric phosphoric sulfate (PFPS, polysilicon ferric sulfate (PFSS, and polyferric sulfate (PFS were synthesized; their structure and morphology were characterized by Fourier transformed infrared (FT-IR spectroscopy, X-ray diffraction (XRD and Scanning electron microscope (SEM. Alkali titration and Ferron species analysis were employed to investigate the hydrolysis performance and species distribution. Jar test was conducted to measure their coagulation behaviors at different dosage, pH, and temperatures in which the flocs properties were measured. The results showed that a number of new compounds were formed due to the presence of PO4(3- and SiO3(2-. Moreover, PFPS and PFSS had similar level in Fea as well as Feb. Among them, PFPS produced more multi-core iron atoms polymer and content of Feb, and the formed flocs were larger and denser. It exhibited superior coagulation performance in terms of turbidity reduction, UV254 removal and residual ferric concentration. Jar test and floc breakage/regrowth experiments indicated other than charge neutrality, the dominated mechanism involved in PFSS was the adsorption between polysilicic acid and solution particle, while PFPS was sweeping, entrapment/adsorption resulting from larger polymer colloid of Fe-P chemistry bond.

The influence of hydraulic conditions on coagulation process effectiveness

Directory of Open Access Journals (Sweden)

Sambor Aleksandra

2017-01-01

Full Text Available This paper presents the impact that small changes in the hydraulic installation between the flocculation chamber and the sedimentation tanks have on coagulation process effectiveness. This study has shown significant improvements in the parameters of the treated water. The research was conducted in two treatment systems: reference and test, in order to compare the changes that were introduced in the time period between January and May 2016. The hydraulic conditions between the flocculation chamber and the sedimentation tank were changed in the test system, leaving the reference system unchanged for comparative purposes. The height-wise positioning of the sedimentation tank relative to the flocculation chamber resulted in a formation of a cascade at the flocculation chamber drain at a height of 0.60m. Air was therefore introduced into the water, forming an air-water mixture, which disturbed the flow between the devices. It was found that floc transported by the pipeline was broken down, which hampered sedimentation in the sedimentation tank. This was confirmed by the analysis of chosen parameters from treated water. After changes in the hydraulic system, changes in water turbidity were noticed, indicating an increase in post-coagulation suspension separation effectiveness. Consequently, an increase in organic carbon removal was found relative to the reference system. This change influenced changes in UV254 absorbance to a much lesser extent.

The influence of hydraulic conditions on coagulation process effectiveness

Science.gov (United States)

Sambor, Aleksandra; Ferenc, Zbigniew

2017-11-01

This paper presents the impact that small changes in the hydraulic installation between the flocculation chamber and the sedimentation tanks have on coagulation process effectiveness. This study has shown significant improvements in the parameters of the treated water. The research was conducted in two treatment systems: reference and test, in order to compare the changes that were introduced in the time period between January and May 2016. The hydraulic conditions between the flocculation chamber and the sedimentation tank were changed in the test system, leaving the reference system unchanged for comparative purposes. The height-wise positioning of the sedimentation tank relative to the flocculation chamber resulted in a formation of a cascade at the flocculation chamber drain at a height of 0.60m. Air was therefore introduced into the water, forming an air-water mixture, which disturbed the flow between the devices. It was found that floc transported by the pipeline was broken down, which hampered sedimentation in the sedimentation tank. This was confirmed by the analysis of chosen parameters from treated water. After changes in the hydraulic system, changes in water turbidity were noticed, indicating an increase in post-coagulation suspension separation effectiveness. Consequently, an increase in organic carbon removal was found relative to the reference system. This change influenced changes in UV254 absorbance to a much lesser extent.

Temperature-controlled radiofrequency ablation of cardiac tissue

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, Adrian

1999-01-01

BACKGROUND: A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available for the frequ......BACKGROUND: A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available...... for the frequently used temperature-controlled mode. The purpose of the present experimental study was to evaluate the impact during temperature-controlled radiofrequency ablation of three basic factors regarding electrode-tissue contact and convective cooling on lesion size. METHODS AND RESULTS: In vitro strips......-controlled radiofrequency ablation increased external cooling of the electrode tip due to either flow of the surrounding liquid or poor electrode tissue contact, as exemplified by perpendicular versus parallel electrode orientation, increases lesion size significantly. This is in contrast to the impact of these factors...

Pulsed Radiofrequency Ablation for Treating Sural Neuralgia.

Science.gov (United States)

Abd-Elsayed, Alaa; Jackson, Markus; Plovanich, Elizabeth

2018-01-01

Sural neuralgia is persistent pain in the distribution of the sural nerve that provides sensation to the lateral posterior corner of the leg, lateral foot, and fifth toe. Sural neuralgia is a rare condition but can be challenging to treat and can cause significant limitation. We present 2 cases of sural neuralgia resistant to conservative management that were effectively treated by pulsed radiofrequency ablation. A 65-year-old female developed sural neuralgia after a foot surgery and failed conservative management. She had successful sural nerve blocks, and pulsed radiofrequency ablation led to an 80% improvement in her pain. A 33-year-old female presented with sural neuralgia secondary to two falls. The patient had tried several conservative modalities with no success. We performed diagnostic blocks and pulsed radiofrequency ablation, and the patient reported 80% improvement in her pain. Pulsed radiofrequency ablation may be a safe and effective treatment for patients with sural neuralgia that does not respond to conservative therapy. However, studies are needed to elucidate its effectiveness and safety profile.

Bipolar radiofrequency ablation of liver metastases during laparotomy. First clinical experiences with a new multipolar ablation concept.

Science.gov (United States)

Ritz, Joerg-Peter; Lehmann, Kai S; Reissfelder, Christoph; Albrecht, Thomas; Frericks, Bernd; Zurbuchen, Urte; Buhr, Heinz J

2006-01-01

radiofrequency using the novel multipolar ablation concept permits a safe and effective therapy for the induction of large volumes of coagulation in the local treatment of liver metastases.

Combined infrared light and bipolar radiofrequency for skin tightening in Asians.

Science.gov (United States)

Yu, Carol S; Yeung, Chi K; Shek, Samantha Y; Tse, Raymond K; Kono, Taro; Chan, Henry H

2007-07-01

As the demand for non-invasive procedures for skin tightening is increasing, combined optical and radiofrequency (RF) devices have recently emerged. The purpose of this study is to evaluate the safety and efficacy of a device that combined broadband infrared (IR) light (700-2000 nm) and bipolar RF (electro-optical synergy [ELOS]) for non-ablative treatment of facial laxity. DESIGN/MATERIALS AND METHODS: Nineteen Chinese volunteers of skin types III-V, with facial laxity and periorbital rhytides, received three treatments at 3-week intervals with combined IR (700-2000 nm, 10 W/cm(2)) and RF energies (70-120 J/cm(3)). Standardized photographs were taken by the Canfield Visia CR system at baseline and serially for 3 months after the last treatment. Two masked assessors evaluated the photographs to assess the improvement in skin laxity. Patient satisfaction scores were also obtained. At 3 months after the last treatment, 89.5% of the subjects reported moderate to significant subjective improvement in skin laxity of cheek, jowl, periorbital area and upper neck, with a high overall satisfaction rating. Masked observers' assessments were less remarkable. Mild improvement in skin laxity was observed over mid and lower face. There was no serious complication. The combination of broadband infrared light and bipolar radiofrequency produces mild improvement of facial laxity in Asians with no serious adverse sequelae. A high patients' satisfaction is achieved. However, further studies are necessary to demonstrate the long-term effects of the procedure and to optimize treatment parameters. (c) 2007 Wiley-Liss, Inc.

MicroElectroMechanical devices and fabrication technologies for radio-frequency analog signal processing

Science.gov (United States)

Young, Darrin Jun

The proliferation of wireless services creates a pressing need for compact and low cost RF transceivers. Modern sub-micron technologies provide the active components needed for miniaturization but fail to deliver high quality passives needed in oscillators and filters. This dissertation demonstrates procedures for adding high quality inductors and tunable capacitors to a standard silicon integrated circuits. Several voltage-controlled oscillators operating in the low Giga-Hertz range demonstrate the suitability of these components for high performance RF building blocks. Two low-temperature processes are described to add inductors and capacitors to silicon ICs. A 3-D coil geometry is used for the inductors rather than the conventional planar spiral to substantially reduce substrate loss and hence improve the quality factor and self-resonant frequency. Measured Q-factors at 1 GHz are 30 for a 4.8 nH device, 16 for 8.2 nH and 13.8 nH inductors. Several enhancements are proposed that are expected to result in a further improvement of the achievable Q-factor. This research investigates the design and fabrication of silicon-based IC-compatible high-Q tunable capacitors and inductors. The goal of this investigation is to develop a monolithic low phase noise radio-frequency voltage-controlled oscillator using these high-performance passive components for wireless communication applications. Monolithic VCOs will help the miniaturization of current radio transceivers, which offers a potential solution to achieve a single hand-held wireless phone with multistandard capabilities. IC-compatible micromachining fabrication technologies have been developed to realize on-chip high-Q RF tunable capacitors and 3-D coil inductors. The capacitors achieve a nominal capacitance value of 2 pF and can be tuned over 15% with 3 V. A quality factor over 60 has been measured at 1 GHz. 3-D coil inductors obtain values of 4.8 nH, 8.2 nH and 13.8 nH. At 1 GHz a Q factor of 30 has been achieved

Coagulation profile in patients undergoing video-assisted thoracoscopic lobectomy

DEFF Research Database (Denmark)

Christensen, Thomas Decker; Vad, Henrik; Pedersen, Søren

2017-01-01

-, and the first two days postoperatively by standard coagulation blood test, thromboelastometry (ROTEM®) and thrombin generation. Results: Patients undergoing potential curative surgery for lung cancer were not hypercoagulable preoperatively. There was no statistically significant difference in the majority......Background: Knowledge about the impact of Low-Molecular-Weight Heparin (LMWH) on the coagulation system in patients undergoing minimal invasive lung cancer surgery is sparse. The aim of this study was to assess the effect of LMWH on the coagulation system in patients undergoing Video......-Assisted Thoracoscopic Surgery (VATS) lobectomy for primary lung cancer. Methods: Sixty-three patients diagnosed with primary lung cancer undergoing VATS lobectomy were randomized to either subcutaneous injection with dalteparin (Fragmin®) 5000 IE once daily or no intervention. Coagulation was assessed pre-, peri...

Radiofrequency (RF) radiation measurement for diathermy machine

International Nuclear Information System (INIS)

Rozaimah Abdul Rahim; Roha Tukimin; Mohd Amirul Nizam; Ahmad Fadzli; Mohd Azizi

2010-01-01

Full-text: Diathermy machine is one of medical device that use widely in hospital and clinic. During the diathermy treatment, high radiofrequency (RF) currents (shortwave and microwave) are used to heat deep muscular tissues through electromagnetic energy to body tissues. The heat increases blood flow, relieve pain and speeding up recovery. The stray RF radiation from the machine can exposes to unintended tissue of the patient, to the operator (physical therapist) and also can cause electromagnetic interference (EMI) effect to medical devices around the machine. The main objective of this study is to establish a database of the RF radiation exposure levels experienced by the operator and patient during the treatments. RF radiation (electric and magnetic field) produced by the diathermy machines were measured using special RF survey meters. The finding of this study confirms that radiation levels on the surface and near the applicator of the diathermy machine much more elevated due to the much closer distance to the source and they exceeding the occupational and general public exposure limit. The results also shows the field strengths drop very significantly when the distance of measurement increase. (author)

Characterization of coagulation factor synthesis in nine human primary cell types

NARCIS (Netherlands)

Dashty, Monireh; Akbarkhanzadeh, Vishtaseb; Zeebregts, Clark J.; Spek, C. Arnold; Sijbrands, Eric J.; Peppelenbosch, Maikel P.; Rezaee, Farhad

2012-01-01

The coagulation/fibrinolysis system is essential for wound healing after vascular injury. According to the standard paradigm, the synthesis of most coagulation factors is restricted to liver, platelets and endothelium. We challenged this interpretation by measuring coagulation factors in nine human

A Quick-responsive DNA Nanotechnology Device for Bio-molecular Homeostasis Regulation.

Science.gov (United States)

Wu, Songlin; Wang, Pei; Xiao, Chen; Li, Zheng; Yang, Bing; Fu, Jieyang; Chen, Jing; Wan, Neng; Ma, Cong; Li, Maoteng; Yang, Xiangliang; Zhan, Yi

2016-08-10

Physiological processes such as metabolism, cell apoptosis and immune responses, must be strictly regulated to maintain their homeostasis and achieve their normal physiological functions. The speed with which bio-molecular homeostatic regulation occurs directly determines the ability of an organism to adapt to conditional changes. To produce a quick-responsive regulatory system that can be easily utilized for various types of homeostasis, a device called nano-fingers that facilitates the regulation of physiological processes was constructed using DNA origami nanotechnology. This nano-fingers device functioned in linked open and closed phases using two types of DNA tweezers, which were covalently coupled with aptamers that captured specific molecules when the tweezer arms were sufficiently close. Via this specific interaction mechanism, certain physiological processes could be simultaneously regulated from two directions by capturing one biofactor and releasing the other to enhance the regulatory capacity of the device. To validate the universal application of this device, regulation of the homeostasis of the blood coagulant thrombin was attempted using the nano-fingers device. It was successfully demonstrated that this nano-fingers device achieved coagulation buffering upon the input of fuel DNA. This nano-device could also be utilized to regulate the homeostasis of other types of bio-molecules.

Effect of radiofrequency microtenotomy on degeneration of tendons: an experimental study on rabbits.

Science.gov (United States)

Gunes, Taner; Bilgic, Erkal; Erdem, Mehmet; Bostan, Bora; Koseoglu, Resit Dogan; Sahin, Seyyid Ahmet; Sen, Cengiz

2014-03-01

Radiofrequency microtenotomy is used to enhance healing by increasing vascularity in the degenerated tendon. In the present study, the effect of radiofrequency microtenotomy (Rf-mt) treatment on tendon degeneration was investigated. A total of 32 New Zealand rabbits were enrolled in the current study. Experimental degeneration was performed by injecting prostaglandin E1 (PGE1) into the bilateral Achilles tendons of rabbits. After excluding 4 rabbits with an infection on the injection site, 4 other rabbits were sacrificed to define the histopathologic changes in the tendons. The remaining 24 rabbits were divided into 2 groups: the control group and the Rf-mt group. In the control group, the Rf-mt device was only applied to the Achilles tendon without running the device. In the Rf-mt group, the Rf-mt device was applied bilaterally at the fourth energy level for 500ms to an area within 2cm proximal to the insertion site at 0.5cm intervals in order to form a grid. Six rabbits from each group were sacrificed at 6 and 12 weeks. The Achilles tendons were evaluated histopathologically by a modified Movin scale and by immunohistopathologic staining for vascular endothelial growth factor and type 4 collagen. After the PGE1 injection, findings similar to chronic degenerative tendinopathy were observed. The Rf-mt group showed significant improvement in vascularity in the histopathological and immunohistochemical examination (P0.05). Rf-mt treatment increases vascularity in degenerated tendons but does not create difference to facilitate the healing process comparing control group. Copyright © 2013 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Radiofrequency electromagnetic radiation from cell phone causes defective testicular function in male Wistar rats.

Science.gov (United States)

Oyewopo, A O; Olaniyi, S K; Oyewopo, C I; Jimoh, A T

2017-12-01

Cell phones have become an integral part of everyday life. As cell phone usage has become more widespread, concerns have increased regarding the harmful effects of radiofrequency electromagnetic radiation from these devices. The current study was undertaken to investigate the effects of the emitted radiation by cell phones on testicular histomorphometry and biochemical analyses. Adult male Wistar rats weighing 180-200 g were randomly allotted to control, group A (switched off mode exposure), group B (1-hr exposure), group C (2-hr exposure) and group D (3-hr exposure). The animals were exposed to radiofrequency electromagnetic radiation of cell phone for a period of 28 days. Histomorphometry, biochemical and histological investigations were carried out. The histomorphometric parameters showed no significant change (p electromagnetic radiation of cell phone leads to defective testicular function that is associated with increased oxidative stress and decreased gonadotropic hormonal profile. © 2017 Blackwell Verlag GmbH.

Treating multiple body parts for skin laxity and fat deposits using a novel focused radiofrequency device with an ultrasound component: Safety and efficacy study.

Science.gov (United States)

Chilukuri, Suneel; Denjean, Dominique; Fouque, Linda

2017-12-01

Growing demand for noninvasive skin tightening and reduction in fat results in an increasing pressure for devices with good clinical efficacy, consistency of results, and high patient comfort. The objective was to validate clinical efficacy and versatility of a novel device, which combines radiofrequency (RF) and ultrasound for treating skin laxity and fat deposits. We treated 34 subjects with facial skin laxity and/or abundant body or arm fat deposits. Subjects were divided based on their indications. Ten subjects received treatments to the face, 7 subjects to arms, 8 subjects to thighs, and 9 subjects on abdomen. All patients received 4 treatments on a weekly basis. Photographs of patients were assessed by blinded evaluators to recognize the baseline images from the 3-month follow-up images. Patient comfort and satisfaction were evaluated using a 5-point Likert scale questionnaire. Any adverse events were recorded. Patient images were correctly recognized in >90% of cases in all study groups. Patient questionnaires showed overall satisfaction with the therapy course and results. On a scale of 1 to 5, the patients agreed (4.1) that they are satisfied with the results that the treatment is comfortable (4.1) and that they are satisfied with the treatment time (4.1). No adverse events were reported. Consistent clinical efficacy was confirmed across all the treated areas, together with high patient comfort and satisfaction. We conclude the device is a highly versatile solution that can deliver results across body parts and different indications. © 2017 The Authors Journal of Cosmetic Dermatology Published by Wiley Periodicals, Inc.

Treatment of sugar beet thick juice spent wash by chemical and natural coagulants

Directory of Open Access Journals (Sweden)

Antov Mirjana G.

2009-01-01

Full Text Available The possibility of treatment of wastewater from bioethanol production by aluminium sulfate and natural coagulant extracted from common bean seed was studied. The highest coagulation activity at pH 6.5 is reached with analum dose of 1 g/l, but only a little lower coagulation activities were obtained by the dose of 0.05 and 0.10 g/l, which is more favorable for economic and environmental reasons. When natural coagulant from common bean was applied the highest coagulation activity, 14.3%, at pH 6.5 is reached with a dose of 0.5 ml/l. However, when common bean natural coagulant was used simultaneously with alum, the highest turbidity removal resulting in 24% coagulation activity was achieved and this was more efficient than when alum or natural coagulant were used.

The radiofrequency frontier: a review of radiofrequency and combined radiofrequency pulsed-light technology in aesthetic medicine.

Science.gov (United States)

Sadick, Neil; Sorhaindo, Lian

2005-05-01

Radiofrequency (RF) and combined RF light source technologies have established themselves as safe and effective treatment modalities for several dermatologic procedures, including skin tightening, hair and leg vein removal, acne scarring, skin rejuvenation, and wrinkle reduction. This article reviews the technology, clinical applications, and recent advances of RF and combined RF light/laser source technologies in aesthetic medicine.

Coagulation management in patients undergoing neurosurgical procedures.

Science.gov (United States)

Robba, Chiara; Bertuetti, Rita; Rasulo, Frank; Bertuccio, Alessando; Matta, Basil

2017-10-01

Management of coagulation in neurosurgical procedures is challenging. In this contest, it is imperative to avoid further intracranial bleeding. Perioperative bleeding can be associated with a number of factors, including anticoagulant drugs and coagulation status but is also linked to the characteristic and the site of the intracranial disorder. The aim of this review will be to focus primarily on the new evidence regarding the management of coagulation in patients undergoing craniotomy for neurosurgical procedures. Antihemostatic and anticoagulant drugs have shown to be associated with perioperative bleeding. On the other hand, an increased risk of venous thromboembolism and hypercoagulative state after elective and emergency neurosurgery, in particular after brain tumor surgery, has been described in several patients. To balance the risk between thrombosis and bleeding, it is important to be familiar with the perioperative changes in coagulation and with the recent management guidelines for anticoagulated patients undergoing neurosurgical procedures, in particular for those taking new direct anticoagulants. We have considered the current clinical trials and literature regarding both safety and efficacy of deep venous thrombosis prophylaxis in the neurosurgical population. These were mainly trials concerning both elective surgical and intensive care patients with a poor grade intracranial bleed or multiple traumas with an associated severe traumatic brain injury (TBI). Coagulation management remains a major issue in patients undergoing neurosurgical procedures. However, in this field of research, literature quality is poor and further studies are necessary to identify the best strategies to minimize risks in this group of patients.

Influence of Radiofrequency Electromagnetic Fields on the Fertility System: Protocol for a Systematic Review and Meta-Analysis.

Science.gov (United States)

Roozbeh, Nasibeh; Abdi, Fatemeh; Amraee, Azadeh; Atarodi Kashani, Zahra; Darvish, Leili

2018-02-08

Due to the increased number of users of mobile phones, tablets, and other devices over the past few years, concerns about the potential impact of mobile phones on health are growing. The influence of mobile phone exposure on male fertility has been studied in recent years. Other research has shown that electromagnetic fields (EMFs) increase macrophages in the corpus luteum and growing follicles. Due to conflicting results among studies and since no systematic review has been performed to analyze the effects of radiofrequency EMF exposure from electronic devices on the fertility system in recent years, this evidence-based study is necessary. The main objectives of this study are to determine the best evidence associated with the influence of radiofrequency EMFs on the fertility system and to provide insight into a potential mechanism using our observations. In this systematic review, the databases and gray literature will be searched with no language and date limitation. The following databases will be searched: Cochrane Library, MEDLINE, PubMed, EMBASE, CINAHL, ProQuest, Scopus, Science Direct, Google Scholar, and other Persian databases. The combination of the Medical Subject Heading terms "radiofrequency electromagnetic" and "male reproductive system" or "female reproductive system" will be searched. Observational study designs will be included but case reports, case series, reviews, and letters to the editor will be excluded. Papers selected for retrieval will be evaluated by two independent referees for methodological validation before entering a review using the Newcastle-Ottawa Scale for nonrandomized studies and cohort studies. The results of this study will be submitted to a peer-reviewed journal for publication and also presented at PROSPERO. This systematic review will provide evidence-based data on the effect of radiofrequency EMFs on the fertility system. This article will also classify the harmful effect of radiofrequency waves on primary and

Coagulation defects in experimental hepatic injury in the dog.

Science.gov (United States)

Osbaldiston, G W; Hoffman, M W

1971-04-01

Alteration in activity of blood coagulation factors in dogs with acute hepatic injury caused by oral carbon tetrachloride dosing was studied. Coagulation Factors II, VII and IX were dramatically reduced within 48 hours but recovered to normal in the next five days. Because surgery is rarely performed on dogs with hepatic necrosis, the use of fresh whole blood tranfusion to improve the coagulation defect in hepatic injury was also studied. Transfusion was found to have only a temporary beneficial effect.

Treatment of acne vulgaris with fractional radiofrequency microneedling.

Science.gov (United States)

Kim, Sang Tae; Lee, Kang Hoon; Sim, Hyung Jun; Suh, Kee Suck; Jang, Min Soo

2014-07-01

Fractional radiofrequency microneedling is a novel radiofrequency technique that uses insulated microneedles to deliver energy to the deep dermis at the point of penetration without destruction of the epidermis. It has been used for the treatment of various dermatological conditions including wrinkles, atrophic scars and hypertrophic scars. There have been few studies evaluating the efficacy of fractional radiofrequency microneedling in the treatment of acne, and none measuring objective parameters like the number of inflammatory and non-inflammatory acne lesions or sebum excretion levels. The safety and efficacy of fractional radiofrequency microneedling in the treatment of acne vulgaris was investigated. In a prospective clinical trial, 25 patients with moderate to severe acne were treated with fractional radiofrequency microneedling. The procedure was carried out three times at 1-month intervals. Acne lesion count, subjective satisfaction score, sebum excretion level and adverse effects were assessed at baseline and at 4, 8 and 12 weeks after the first treatment as well as 4, 8 and 12 weeks after the last treatment. Number of acne lesions (inflammatory and non-inflammatory) decreased. Sebum excretion and subjective satisfaction were more favorable at every time point compared with the baseline values (P acne vulgaris. © 2014 Japanese Dermatological Association.

Treatment of phosphate-containing oily wastewater by coagulation and microfiltration.

Science.gov (United States)

Zhang, Jin; Sun, Yu-xin; Huang, Zhi-feng; Liu, Xing-qin; Meng, Guang-yao

2006-01-01

The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment. At the coagulant Ca (OH)2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca(OH)2 was not used. The permeate obtained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are transmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparison results show that 0.2 microm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substantial gain in flux and removal efficiency of phosphate.

IMPROVEMENT OF COAGULATION PROCESS FOR THE PRUT RIVER WATER TREATMENT USING ALUMINUM SULPHATE

Directory of Open Access Journals (Sweden)

Larisa Postolachi

2015-06-01

Full Text Available The aim of presented research was to optimize the treatment process of the Prut River water. In order to realize the proposed goal, there were studied the following factors which can improve the process of coagulation: (i the influence of stirring speed during coagulation and (ii the influence of the concentration of the coagulant solution added in the process of coagulation. The optimal conditions of coagulation were established using the Jar-test method. Application of the recommended procedure contribute to the reduction of the coagulant dose, the contact time, the aluminum concentration in water and the expenses for water treatment.

[Clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis].

Science.gov (United States)

Oyake, Daisuke; Ochi, Kentaro; Takatsu, Mitsuharu; Shintani, Toshiharu; Umehara, Tsuyoshi; Koizuka, Izumi

2004-07-01

The clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis was evaluated. A bipolar radiofrequency system (CelonLab ENT) was used to treat 16 patients suffering from allergic rhinitis between February 2003 and August 2003. The thermotherapy was performed under local anesthesia at the otolaryngology outpatient clinic of St. Marianna University Toyoko Hospital. Data were collected by questionnaire and rhinomanometry preoperatively and 2 months postoperatively. The mean visual analogue scale (VAS) score for intraoperative pain was 31 mm (range, 0-100), and nearly all the patients felt no or a subtle pain during the thermotherapy. Postoperative pain was also well tolerated, with nearly all the patients not requiring analgesic drugs. Postoperative bleeding was minor, and none of the patients required additional treatment for bleeding. Nearly all the patients reported an improvement in their nasal patency, rhinorrhea, headaches, and sleeping. Statistically significant improvements were observed for all the measured VAS scores: nasal patency, rhinorrhea, headache, and olfactory function. Nasal resistance, as measured by anterior rhinomanometry, significantly improved after treatment. The effect of decongestion was also measured using anterior rhinomanometry. The ratio of nasal resistance before and after decongestion was significantly higher after thermotherapy, suggesting that nasal decongestion had a smaller effect on nasal patency after treatment. The current results suggest that the CelonLab ENT device is an effective and safe treatment for allergic rhinitis.

Coagulation profile of children with sickle cell anemia in steady state ...

African Journals Online (AJOL)

Background: Sickle cell anemia is associated with a hypercoagulable state that may lead to alterations in a coagulation profile. Measurements of coagulation factors are known to have some predictive value for clinical outcome. Objectives: To determine the coagulation profile of children with SCA in steady state and crisis ...

Disseminated intravascular coagulation (DIC)

Science.gov (United States)

... Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 141. Thachil J, Toh CH. Current concepts in the management of disseminated intravascular coagulation. Thromb Res . 2012;129 ...

Vitamin K: from coagulation to calcification.

Science.gov (United States)

Paakkari, Ilari

Vitamin K is not only essential for the synthesis of coagulation factors in the liver, but it also strengthens the bones and prevents calcification of the arteries. These effects are mediated through the same mechanism, i.e. carboxylation of Gla target proteins. The discovery of novel Gla proteins that are not associated with blood coagulation or calcium metabolism indicates that vitamin K has additional effects in the pancreas and the central nervous system, for example. As dietary supplements, vitamin K1 of plant origin and vitamins K2 of bacterial origin may exert different effects.

New resonant circuits for the ISOLTRAP radiofrequency quadrupole trap

CERN Document Server

SENECAL, Pierre

2015-01-01

This report describes my work during my Summer Student Program. My main project was building and testing a resonance-circuit box for a radio-frequency power supply used with the radio-frequency cooler and buncher.

Flexible GaN for High Performance, Strainable Radio Frequency Devices (Postprint)

Science.gov (United States)

2017-11-02

wireless systems where consumers will benefit significantly from the high power densities achievable in GaN devices.[8] Further complicating the...future strainable and conformal devices for transmission of radio-frequency (RF) signals over large distances for more efficient wireless communication... power density of traditional RF amplifier materials at different frequencies and wireless generation bands, as well as an image of the flexible GaN

WATER PURIFICATION BY COAGULATION UNDER THE INFLUENCE OF ULTRASONIC FIELD

Directory of Open Access Journals (Sweden)

Vikulina Vera Borisovna

2016-03-01

Full Text Available The authors carried out experiments on the in-fluence of ultrasound on the subsidence of suspended materials. The efficiency of coagulation process in wa-ter purification in ultrasound field is estimated. The influence of ultrasound on the water with suspended materials before introducing coagulant was a condition of the experiment. The magnetostriction method for obtaining ultrasound oscillations with the help of ultra-sound generator of batch production was applied. The samples were chosen and the coagulation process was controlled using standard procedures. The experimental data was obtained which estimate the efficiency in-crease in the subsidence of suspended materials de-pending on the duration of ultrasound processing. Dur-ing one minute of ultrasound processing the following results were obtained: the subsidence efficiency in-creased by 25.83 % in case of coagulant share Al2O3 2.5 mg/l; the subsidence efficiency increased by 23.70 % in case of coagulant share Al2O3 5.0 mg/l.

Physiological levels of blood coagulation factors IX and X control coagulation kinetics in an in vitro model of circulating tissue factor

International Nuclear Information System (INIS)

Tormoen, Garth W; Khader, Ayesha; Gruber, András; McCarty, Owen J T

2013-01-01

Thrombosis significantly contributes to cancer morbidity and mortality. The mechanism behind thrombosis in cancer may be circulating tissue factor (TF), as levels of circulating TF are associated with thrombosis. However, circulating TF antigen level alone has failed to predict thrombosis in patients with cancer. We hypothesize that coagulation factor levels regulate the kinetics of circulating TF-induced thrombosis. Coagulation kinetics were measured as a function of individual coagulation factor levels and TF particle concentration. Clotting times increased when pooled plasma was mixed at or above a ratio of 4:6 with PBS. Clotting times increased when pooled plasma was mixed at or above a ratio of 8:2 with factor VII-depleted plasma, 7:3 with factor IX- or factor X-depleted plasmas, or 2:8 with factor II-, V- or VIII-depleted plasmas. Addition of coagulation factors VII, X, IX, V and II to depleted plasmas shortened clotting and enzyme initiation times, and increased enzyme generation rates in a concentration-dependent manner. Only additions of factors IX and X from low-normal to high-normal levels shortened clotting times and increased enzyme generation rates. Our results demonstrate that coagulation kinetics for TF particles are controlled by factor IX and X levels within the normal physiological range. We hypothesize that individual patient factor IX and X levels may be prognostic for susceptibility to circulating TF-induced thrombosis. (paper)

Coagulation and flocculation of dissolved organic substances with organic polymers

OpenAIRE

Kvinnesland, Thomas

2002-01-01

Coagulation of natural organic matter (NOM) in water is a well-established process, enabling or enhancing the removal of these substances by different particle separation processes. The dominating coagulating agents used are, however, inorganic salts of iron (Fe3+) and aluminium (Al3+). The primary use of organic polymers is as flocculating agents for already coagulated aggregates. However, in recent years the use of cationic organic polymers have received increasing attent...

The performance of double layer structure membrane prepared from flowing coagulant

Science.gov (United States)

Mieow Kee, Chan; Xeng, Anthony Leong Chan; Regal, Sasiskala; Singh, Balvinder; Raoo, Preeshaath; Koon Eu, Yap; Sok Choo, Ng

2017-12-01

Membrane with double layer structure is favourable as it exhibits smooth surface and macrovoids free structure. However, its’ performance in terms of permeability, porosity and strength has not been studied thoroughly. Additionally, the effect of flowing coagulant on the formation of double layer membrane has not been reported. Thus, the objective of this study is to investigate the performance of double layer membranes, which were prepared using flowing coagulant. Results showed that when the coagulant flow changed from laminar to turbulent, the pure water permeation of the membrane increased. It was due to the higher porosity in the membrane, which prepared by turbulent flow (CA-Turbulent) compared to the membrane which fabricated under laminar condition (CA-Laminar). This can be explained by the rapid solvent-coagulant exchange rate between the polymer solution and the turbulent coagulant. In term of strength, the tensile strength of the CA-Turbulent was ~32 MPa, which was 100% higher compared to CA-Laminar. This may due to the presence of large amount of nodules on its surface, which reduced the surface integrity. In conclusion, flowing coagulant altered the membrane properties and adopting turbulent coagulant flow in membrane fabrication would improve the porosity, surface roughness and the strength of the membrane.

Coagulation and Adsorption Treatment of Printing Ink Wastewater

Directory of Open Access Journals (Sweden)

Maja Klančnik

2015-03-01

Full Text Available The intention of the study was to improve the efficiency of total organic carbon (TOC and colour removal from the wastewater samples polluted with flexographic printing ink following coagulation treatments with further adsorption onto activated carbons and ground orange peel. The treatment efficiencies were compared to those of further flocculation treatments and of coagulation and adsorption processes individually. Coagulation was a relatively effective single-treatment method, removing 99.7% of the colour and 86.9% of the organic substances (TOC from the printing ink wastewater samples. Further flocculation did not further eliminate organic pollutants, whereas subsequent adsorption with 7 g/l of granular activated carbon further reduced organic substances by 35.1%, and adsorption with 7 g/l of powdered activated carbon further reduced organic substances by 59.3%. Orange peel was an inappropriate adsorbent for wastewater samples with low amounts of pollution, such as water that had been treated by coagulation. However, in highly polluted printing ink wastewater samples, the adsorption treatment with ground orange peel achieved efficiencies comparable to those of the granular activated carbon treatments.

Novel approaches to the management of disseminated intravascular coagulation

NARCIS (Netherlands)

Levi, M. [=Marcel M.; de Jonge, E.; van der Poll, T.; ten Cate, H.

2000-01-01

Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to widespread deposition of fibrin in the circulation. We addressed the issue of whether there is evidence that this fibrin deposition contributes to multiple organ

A Pontential Agriculture Waste Material as Coagulant Aid: Cassava Peel

Science.gov (United States)

Othman, N.; Abd-Rahim, N.-S.; Tuan-Besar, S.-N.-F.; Mohd-Asharuddin, S.; Kumar, V.

2018-02-01

All A large amount of cassava peel waste is generated annually by small and medium scale industries. This has led to a new policy of complete utilization of raw materials so that there will be little or no residue left that could pose pollution problems. Conversion of these by-products into a material that poses an ability to remove toxic pollutant would increase the market value and ultimately benefits the producers. This study investigated the characteristics of cassava peel as a coagulant aid material and optimization process using the cassava peel was explored through coagulation and flocculation. This research had highlighted that the Cassava peels contain sugars in the form of polysaccharides such as starch and holocellulose. The FTIR results revealed that amino acids containing abundant of carboxyl, hydroxyl and amino groups which has significant capabilities in removing pollutants. Whereas analysis by XRF spectrometry indicated that the CP samples contain Fe2O3 and Al2O3 which might contribute to its coagulation ability. The optimum condition allowed Cassava peel and alum removed high turbidity up to 90. This natural coagulant from cassava peel is found to be an alternative coagulant aid to reduce the usage of chemical coagulants

Evaluation of Impact of Coagulant Type on Operation Parameters in Direct Filtration

Directory of Open Access Journals (Sweden)

Ali Torabian

2007-06-01

Full Text Available Numerous advantages have been reported on PAC (poly aluminum chloride used as a coagulant over other coagulants such as alum and ferric chloride used in conventional water treatment process with medium and high turbidity levels. These include lower amounts of PACL required specially in removing turbidity, larger floc grain formation, reduced floc sedimentation time, lower sludge production, and relaxation of the need for pH adjustment by lime, among others. The present study aims to evaluate the effects of different coagulants such as ferric chloride and PACL on direct filtration and to identify the most effective material based on both turbidity and particle removal efficiencies. A perfectly experimental pilot system, including raw water preparation, coagulation, flocculation, distribution measurement, and filtration units, was designed and used. Raw water turbidity level in the experimental pilot was below 10 NTU. The effects of various parameters such as coagulant type, filtration rate, and coagulant dosage on the performance of the filter were investigated. The results obtained from several filtration cycles under different conditions indicated that average effluent turbidity level, effluent particle numbers, effluent turbidity variation graph, and effluent particle graph were lower throughout the filtration cycle when PACL was used compared to when ferric chloride was used as the coagulant. Increasing filtration rate led to increased turbidity and particle number. Addition of 2 mg/l of PACL (poor coagulation and flocculation scenario was compared with addition of 5 mg/l of ferric chloride (strong coagulation and flocculation scenario. The results indicated that higher average values of turbidity removal but lower turbidity and particle removal efficiencies obtained in the case of the poor coagulation and flocculation scenario.

Radiofrequency for the Treatment of Lumbar Radicular Pain: Impact on Surgical Indications.

Science.gov (United States)

Trinidad, José Manuel; Carnota, Ana Isabel; Failde, Inmaculada; Torres, Luis Miguel

2015-01-01

Study Design. Quasiexperimental study. Objective. To investigate whether radiofrequency treatment can preclude the need for spinal surgery in both the short term and long term. Background. Radiofrequency is commonly used to treat lumbosacral radicular pain. Only few studies have evaluated its effects on surgical indications. Methods. We conducted a quasiexperimental study of 43 patients who had been scheduled for spinal surgery. Radiofrequency was indicated for 25 patients. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment (pulsed radiofrequency of dorsal root ganglion, 76%; conventional radiofrequency of the medial branch, 12%; combined technique, 12%). The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment. In addition, we also evaluated adverse effects, ODI, NRS. Results. We observed after treatment with radiofrequency 80% of patients rejected spinal surgery in the short term and 76% in the long term. We conclude that radiofrequency is a useful treatment strategy that can achieve very similar outcomes to spinal surgery. Patients also reported a very high level of satisfaction (84% satisfied/very satisfied). We also found that optimization of the electrical parameters of the radiofrequency improved the outcome of this technique.

Radiofrequency for the Treatment of Lumbar Radicular Pain: Impact on Surgical Indications

Directory of Open Access Journals (Sweden)

José Manuel Trinidad

2015-01-01

Full Text Available Study Design. Quasiexperimental study. Objective. To investigate whether radiofrequency treatment can preclude the need for spinal surgery in both the short term and long term. Background. Radiofrequency is commonly used to treat lumbosacral radicular pain. Only few studies have evaluated its effects on surgical indications. Methods. We conducted a quasiexperimental study of 43 patients who had been scheduled for spinal surgery. Radiofrequency was indicated for 25 patients. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment (pulsed radiofrequency of dorsal root ganglion, 76%; conventional radiofrequency of the medial branch, 12%; combined technique, 12%. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment. In addition, we also evaluated adverse effects, ODI, NRS. Results. We observed after treatment with radiofrequency 80% of patients rejected spinal surgery in the short term and 76% in the long term. We conclude that radiofrequency is a useful treatment strategy that can achieve very similar outcomes to spinal surgery. Patients also reported a very high level of satisfaction (84% satisfied/very satisfied. We also found that optimization of the electrical parameters of the radiofrequency improved the outcome of this technique.

Treatment of sugar beet extraction juice stillage by natural coagulants extracted from common bean

Directory of Open Access Journals (Sweden)

Prodanović Jelena M.

2015-01-01

Full Text Available Distillery wastewaters have a great pollution potential, and pollution caused by them is one of the most critical environmental issues. This study is concerned with the coagulation efficiency of a new, environmental friendly, natural coagulant extracted from common bean seeds in the primary treatment of distillery wastewater in the bioethanol production from sugar beet juice. Active coagulation components were extracted from ground seeds of common bean with 0.5 mol/L NaCl. The obtained raw extract was used as a coagulant. The coagulation efficiency was measured by jar test at different pH values of wastewater, and a decrease in organic matter content was determined. The experiments confirmed that natural coagulant from common bean could be successfully used for the treatment of extraction juice distillery wastewater. The highest coagulation efficiencies were achieved at the pH 5.2 with a coagulant dose of 30 mL/L, and at the pH 8.5 with a coagulant dose of 5 mL/L, and they were 64.71% and 68.75% respectively. These encouraging results indicate that natural coagulant from common bean seeds is a potential alternative to conventional chemical coagulant/flocculant agents for treatment of wastewaters.[Projekat Ministarstva nauke Republike Srbije, br. III 43005

Symplicity multi-electrode radiofrequency renal denervation system feasibility study.

Science.gov (United States)

Whitbourn, Robert; Harding, Scott A; Walton, Antony

2015-05-01

The aim of this study was to test the safety and performance of the Symplicity™ multi-electrode radio-frequency renal denervation system which was designed to reduce procedure time during renal denervation. The multi-electrode radiofrequency renal denervation system feasibility study is a prospective, non-randomised, open label, feasibility study that enrolled 50 subjects with hypertension. The study utilises a new renal denervation catheter which contains an array of four electrodes mounted in a helical configuration at 90 degrees from each other to deliver radiofrequency energy simultaneously to all four renal artery quadrants for 60 seconds. The protocol specified one renal denervation treatment towards the distal end of each main renal artery with radiofrequency energy delivered for 60 seconds per treatment. Total treatment time for both renal arteries was two minutes. The 12-month change in office systolic blood pressure (SBP) and 24-hour SBP was -19.2±25.2 mmHg, prenal artery stenosis or hypertensive emergencies occurred. The Symplicity multi-electrode radiofrequency renal denervation system was associated with a significant reduction in SBP at 12 months and minimal complications whilst it also reduced procedure time. NCT01699529.

Treatment of Benign Thyroid Nodules: Comparison of Surgery with Radiofrequency Ablation.

Science.gov (United States)

Che, Y; Jin, S; Shi, C; Wang, L; Zhang, X; Li, Y; Baek, J H

2015-07-01

Nodular goiter is one of the most common benign lesions in thyroid nodule. The main treatment of the disease is still the traditional surgical resection, however there are many problems such as general anesthesia, surgical scar, postoperative thyroid or parathyroid function abnormalities, and high nodules recurrence rate in residual gland. The purpose of this study was to compare the efficacy, safety, and cost-effectiveness of 2 treatment methods, surgery and radiofrequency ablation, for the treatment of benign thyroid nodules. From May 2012 to September 2013, 200 patients with nodular goiters who underwent surgery (group A) and 200 patients treated by radiofrequency ablation (group B) were enrolled in this study. Inclusion criteria were the following: 1) cosmetic problem, 2) nodule-related symptoms, 3) hyperfunctioning nodules related to thyrotoxicosis, and 4) refusal of surgery (for group B). An internally cooled radiofrequency ablation system and an 18-ga internally cooled electrode were used. We compared the 2 groups in terms of efficacy, safety, and cost-effectiveness during a 1-year follow-up. After radiofrequency ablation, the nodule volume decreased significantly from 5.4 to 0.4 mL (P = .002) at the 12-month follow-up. The incidence of complications was significantly higher from surgery than from radiofrequency ablation (6.0% versus 1.0%, P = .002). Hypothyroidism was detected in 71.5% of patients after surgery but in none following radiofrequency ablation. The rate of residual nodules (11.9% versus 2.9%, P = .004) and hospitalization days was significantly greater after surgery (6.6 versus 2.1 days, P radiofrequency ablation are both effective treatments of nodular goiter. Compared with surgery, the advantages of radiofrequency ablation include fewer complications, preservation of thyroid function, and fewer hospitalization days. Therefore, radiofrequency ablation should be considered a first-line treatment for benign thyroid nodules. © 2015 by American

Operating Conditions of Coagulation-Flocculation Process for High Turbidity Ceramic Wastewater

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Sameer Al-Asheh

2017-04-01

Full Text Available This work attempted to determine the optimum conditions required for the coagulation and flocculation process as an essential stage of the ceramic wastewater treatment. Coagulation and flocculation is a very necessary step in industries as it lessens turbidity, color, and odor of wastewater. The experimental work was performed in several runs. The volume of wastewater used in each run was 200 mL and was kept at this value throughout. In certain runs, the speed of the mixer was varied while keeping the quantity of coagulant and flocculant constant in order to determine the optimum speed that resulted in the least turbidity. A speed of 5% was chosen as the ideal process speed according to the results obtained. Next, experiments were operated at this optimum speed while changing the dosage of coagulant and flocculant in order to decide the optimum dosage. Coagulant and flocculent amounts of 0.4 g (without booster and 0.2 g (with booster selected after the readings were taken. For all the readings, a turbidity meter was used providing results in Nephelometric Turbidity Units (NTU. Lowest turbidity was achieved when using 5% speed with 0.4 grams of coagulant and 0.4 grams of flocculant, or 5% speed with 0.2 grams of coagulant, 0.2 grams of flocculant and 0.25 g/L of booster coagulant. According to factorial design analysis, such as parameters as impeller speed and dosage have an influential impact on the turbidity; while the booster has insignificant influence and other interactions between parameters are important.

Treatment of sugar beet thick juice spent wash by chemical and natural coagulants

OpenAIRE

Antov Mirjana G.; Klašnja Mile T.; Šćiban Marina B.

2009-01-01

The possibility of treatment of wastewater from bioethanol production by aluminium sulfate and natural coagulant extracted from common bean seed was studied. The highest coagulation activity at pH 6.5 is reached with analum dose of 1 g/l, but only a little lower coagulation activities were obtained by the dose of 0.05 and 0.10 g/l, which is more favorable for economic and environmental reasons. When natural coagulant from common bean was applied the highest coagulation activity, 14.3%, at pH ...

Coagulation sensors based on magnetostrictive delay lines for biomedical and chemical engineering applications

International Nuclear Information System (INIS)

Maliaritsi, E.; Zoumpoulakis, L.; Simitzis, J.; Vassiliou, P.; Hristoforou, E.

2006-01-01

Coagulation sensors based on the magnetostrictive delay line technique are presented in this paper. They are based on magnetostrictive ribbons and are used for measuring the coagulation, curing or solidification time of different liquids. Experimental results indicate that the presented sensing elements can determine the blood coagulation with remarkable repeatability, thus allowing their use as blood coagulation sensors. Additionally, results indicate that they can also measure curing time of resins, solidification of fluids and coagulation of chemical substances, therefore allowing their implementation in chemical engineering applications

Superiority of ferric chloride as coagulant over alum and ferrous sulphate at controlled pH and cost comparison of these coagulant

International Nuclear Information System (INIS)

Irfan, M.

2008-01-01

This study was conducted by author as a member of Specialty Chemical Division of Sitara Chemical Industries which is the largest chlor -alkali manufacturing industry in Pakistan. Sitara is also producing FeCl/sub 3/ as a byproduct to consume its additional quantity of chlorine produced during electrolysis of brine solution for caustic soda preparation. Most of the industries are using Alum along with other polymers for treatment of effluent waste water. Treatment system is based on sand bed filters. For coagulation of unwanted materials present in the water, Alum is being used with Anionic Polymer (Accofloc-A2125) as flocculent. But the ferric chloride is not only functions as a reactants to remove water impurities but it also functions as a both coagulant and a Flocculent. This study was conducted for finding best alternative chemicals to improve treated water quality. For this purpose Ferric Chloride (FeCl/sub 3/) is used as best alternative of alum for better removal of turbidity, heavy metals and micro organisms to eradicate above said problems and for better removal of turbidity, heavy metals and micro, organisms to eradicate health problems. As per lab scale results quality of treated water with Ferric Chloride (FeCl/sub 3/) proved better than that of Alum. The main objective of this research is to investigate the efficiency of coagulation and flocculation processes for removing suspended solids, colour and COD which present in significant quantity. Three types of coagulants were examined using standard jar test apparatus, i.e., aluminum sulphate (alum), ferric chloride (FeCl/sub 3/) and ferrous sulphate (FeSO/sub 4/). The effects of agitation speed, settling time, pH, coagulant dosages and temperature were examined. At 300 rpm of rapid mixing and 50 rpm of slow mixing and 60 minutes settling time, higher removals of suspended solids (over 95%), colour (90%) and COD (43%) were achieved at pH 4 and 12. FeCl/sub 3/ was found to be superior compared with other

Using Coagulation Process in Optimizing Natural Organic Matter Removal from Low Turbidity Waters

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Alireza Mesdaghinia

2006-03-01

Full Text Available Optimization of coagulation process  for efficient removal of Natural Organic Matters (NOM has gained a lot of focus over the last years to meet the requirements of enhanced coagulation. NOM comprises both particulate and soluble components which the latter usually comprises the main portion. Removal of soluble NOM from low turbidity waters by coagulation is not a successful process unless enough attention is paid to stages of formation and development of both micro and macro-flocs. This study, which presents experimental results from pilot scale research studies aimed at optimizing coagulation process applied to synthetic raw waters supplemented by adding commercial humic acid with low turbidity levels, explains how pH and turbidity can be controlled to maximize soluble NOM removal. The removal of NOM at various coagulant doses and coagulation pHs has been assessed through raw and treated (coagulated-settled water measurements of total organic carbon (TOC. For low turbidity waters, essential floc nucleation sites can be provided by creating synthetic turbidities, for example by adding clay. Adjusting the initial pH at 5.5 or adding clay before coagulant addition allows the formation of micro-flocs as well as formation of the insoluble flocs at low coagulant doses.

Charging and coagulation of radioactive and nonradioactive particles in the atmosphere

International Nuclear Information System (INIS)

Kim, Yong-ha; Yiacoumi, Sotira

2016-01-01

Charging and coagulation influence one another and impact the particle charge and size distributions in the atmosphere. However, few investigations to date have focused on the coagulation kinetics of atmospheric particles accumulating charge. This study presents three approaches to include mutual effects of charging and coagulation on the microphysical evolution of atmospheric particles such as radioactive particles. The first approach employs ion balance, charge balance, and a bivariate population balance model (PBM) to comprehensively calculate both charge accumulation and coagulation rates of particles. The second approach involves a much simpler description of charging, and uses a monovariate PBM and subsequent effects of charge on particle coagulation. The third approach is further simplified assuming that particles instantaneously reach their steady-state charge distributions. It is found that compared to the other two approaches, the first approach can accurately predict time-dependent changes in the size and charge distributions of particles over a wide size range covering from the free molecule to continuum regimes. The other two approaches can reliably predict both charge accumulation and coagulation rates for particles larger than about 0.04 micrometers and atmospherically relevant conditions. These approaches are applied to investigate coagulation kinetics of particles accumulating charge in a radioactive neutralizer, the urban atmosphere, and an atmospheric system containing radioactive particles. Limitations of the approaches are discussed.

Simultaneous lactic acidification and coagulation by using recombinant Lactococcus lactis strain.

Science.gov (United States)

Raftari, M; Ghafourian, S; Abu Bakar, F

2017-04-01

This study was an attempt to create a novel milk clotting procedure using a recombinant bacterium capable of milk coagulation. The Rhizomucor pusillus proteinase (RPP) gene was sub-cloned into a pALF expression vector. The recombinant pALF-RPP vector was then electro-transferred into Lactococcus lactis. Finally, the milk coagulation ability of recombinant L. lactis carrying a RPP gene was evaluated. Nucleotide sequencing of DNA insertion from the clone revealed that the RPP activity corresponded to an open reading frame consisting of 1218 bp coding for a 43·45 kDa RPP protein. The RPP protein assay results indicated that the highest RPP enzyme expression with 870 Soxhlet units (SU) per ml and 7914 SU/OD were obtained for cultures which were incubated at pH 5·5 and 30°C. Interestingly, milk coagulation was observed after 205 min of inoculating milk with recombinant L. lactis carrying the RPP gene. The recombinant L. lactis carrying RPP gene has the ability to function as a starter culture for acidifying and subsequently coagulating milk by producing RPP as a milk coagulant agent. Creating a recombinant starter culture bacterium that is able to coagulate milk. It is significant because the recombinant L. lactis has the ability to work as a starter culture and milk coagulation agent. © 2016 The Society for Applied Microbiology.

Occupational exposure to radiofrequency fields in antenna towers

International Nuclear Information System (INIS)

Alanko, T.; Hietanen, M.

2007-01-01

Exposure of workers to radiofrequency fields was assessed in two medium-sized antenna towers. Towers had transmitting antennas from different networks, e.g. mobile phone networks, radio and digital TV sub-stations and amateur radio. The levels of radiofrequency fields were measured close to the ladders of the towers. All measured values were below ICNIRP occupational reference levels. (authors)

Critical assessment of chitosan as coagulant to remove cyanobacteria

NARCIS (Netherlands)

Lürling, Miquel; Noyma, Natalia Pessoa; Magalhães, Leonardo de; Miranda, Marcela; Mucci, Maíra; Oosterhout, Frank van; Huszar, Vera L.M.; Marinho, Marcelo Manzi

2017-01-01

Removal of cyanobacteria from the water column using a coagulant and a ballast compound is a promising technique to mitigate nuisance. As coagulant the organic, biodegradable polymer chitosan has been promoted. Results in this study show that elevated pH, as may be common during cyanobacterial

Critical assessment of chitosan as coagulant to remove cyanobacteria

NARCIS (Netherlands)

Lurling, Miguel; Noyma, Natalia Pessoa; Magalhães, de Leonardo; Miranda, Marcela; Mucci, Maíra; Oosterhout, van F.; Huszar, Vera L.M.; Marinho, Marcelo Manzi

2017-01-01

Removal of cyanobacteria from the water column using a coagulant and a ballast compound is a promising technique to mitigate nuisance. As coagulant the organic, biodegradable polymer chitosan has been promoted. Results in this study show that elevated pH, as may be common during cyanobacterial

Coagulation mechanism of salt solution-extracted active component in Moringa oleifera seeds

OpenAIRE

Okuda, Tetsuji; Baes, Aloysius U.; Nishijima, Wataru; Okada, Mitsumasa

2001-01-01

This study focuses on the coagulation mechanism by the purified coagulant solution (MOC-SC-PC) with the coagulation active component extracted from M. oleifera seeds using salt solution. The addition of MOC-SC-PC into tap water formed insoluble matters. The formation was responsible for kaolin coagulation. On the other hand, insoluble matters were not formed when the MOC-SC-PC was added into distilled water. The formation was affected by Ca2+ or other bivalent cations which may connect each m...

Improvement of extraction method of coagulation active components from Moringa oleifera seed

OpenAIRE

Okuda, Tetsuji; Baes, Aloysius U.; Nishijima, Wataru; Okada, Mitsumasa

1999-01-01

A new method for the extraction of the active coagulation component from Moringa oleifera seeds was developed and compared with the ordinary water extraction method (MOC–DW). In the new method, 1.0 mol l-1 solution of sodium chloride (MOC–SC) and other salts were used for extraction of the active coagulation component. Batch coagulation experiments were conducted using 500 ml of low turbid water (50 NTU). Coagulation efficiencies were evaluated based on the dosage required to remove kaolinite...

OPTIMISATION OF HIBISCUS SABDARIFFA AS A NATURAL COAGULANT TO TREAT CONGO RED IN WASTEWATER

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MUN Y. YONG

2016-02-01

Full Text Available The process of coagulation is commonly practiced in water and wastewater treatment to reduce level of dissolved chemical, turbidity and so on with the usage of coagulant. Aluminium sulphate (alum is the most commonly used coagulant, however, recent studies show that residual aluminium in drinking water and sludge may induce Alzheimer’s disease and environmental issues. Natural coagulant which is environmental friendly and non-toxic is developed as an alternative to overcome these issues. In this work, Hibiscus Sabdariffa was studied as natural coagulant to treat dye wastewater containing Congo red. The seeds were extracted with different solvent such as distilled water, 0.5 M NaCl and 0.05 M NaOH to extract the coagulation agent. The working parameters were optimised using Response Surface Methodology (RSM. 0.5 M NaCl was found to have highest colour removal of 95.1 % among the solvents. In addition, Hibiscus Sabdariffa seed was found to be an effective coagulant that has 91.2 % colour removal at the optimal working condition of pH 2, 190 mg/L coagulant dosage at 400 ppm of dye concentration. It was also been identified that the performance of natural coagulant is comparable with conventional coagulant, aluminium sulphate with colour removal of 91.2 % and 92.3 % respectively.

Removal of Arsenic from Drinking Water by Adsorption and Coagulation

Science.gov (United States)

Zhang, M.; Sugita, H.; Hara, J.; Takahashi, S.

2013-12-01

Removal of arsenic from drinking water has been an important issue worldwide, which has attracted greater attentions in recent years especially for supplying safe drinking water in developing countries. Although many kinds of treatment approaches that are available or applicable both in principle and practice, such as adsorption, coagulation, membrane filtration, ion exchange, biological process, electrocoagulation and so on, the first 2 approaches (i.e., adsorption and coagulation) are most promising due to the low-cost, high-efficiency, simplicity of treating systems, and thus can be practically used in developing countries. In this study, a literature survey on water quality in Bangladesh was performed to understand the ranges of arsenic concentration and pH of groundwater in Bangladesh. A series of tests were then organized and performed to investigate the effects of arsenic concentration, arsenic forms, pH, chemical compositions of the materials used for adsorption and coagulation, particle size distribution and treatment time on quality of treated water. The experimental results obtained in the study illustrated that both adsorption and coagulation can be used to effectively reduce the concentrations of either arsenic (V) or arsenic (III) from the contaminated water. Coagulation of arsenic with a magnesium-based material developed in this study can be very effective to remove arsenic, especially arsenic (V), from contaminated water with a concentration of 10 ppm to an undetectable level of 0.002 ppm by ICP analyses. Compared to arsenic (III), arsenic (V) is easier to be removed. The materials used for adsorption and coagulation in this study can remove arsenic (V) up to 9 mg/g and 6 mg/g, and arsenic (III) up to 4 mg/g and 3 mg/g, respectively, depending on test conditions and compositions of the materials being used. The control of pH during treatment can be a challenging technical issue for developing both adsorbent and coagulant. Keywords: Water Treatment

Clinical application and developmental trend of radiofrequency ablation technology

International Nuclear Information System (INIS)

Chen Dongfeng

2009-01-01

For recent two decades, radiofrequency ablation technology has made great progress in the field of the treatment for neoplasm. At the very beginning, radiofrequency ablation was adopted in treating the hepatic carcinoma, and since then it has been gradually practiced in treating malignancies of lung, bone, kidney, breast, prostate and other solid tumors. Statistical report of the year 2008 has indicated that in the aspect of similar therapeutic measures radiofrequency ablation therapy for tumors holds a 9% market share. Moreover, in the coming years the clinical use of this kind of therapy for tumors will be steadily increasing by 13% every year. (authors)

Percutaneous ultrasound-guided radiofrequency ablation for kidney tumors in patients with surgical risk

International Nuclear Information System (INIS)

Salagierski, Marek; Salagierski, Maciej; Sosnowski, Marek; Salagierska-Barwinska, Anna

2006-01-01

The aim of this study was to describe our experience with percutaneous ultrasound-guided radiofrequency ablation of kidney tumors. From July 2002 to August 2005, 45 radiofrequency ablations (RFA) in 42 selected patients with kidney tumor were performed. The patients had either contraindications to surgery procedures or had a solitary kidney. The average tumor size was 37.5 mm (range, 18-59 mm) with the mean age of 68 years (range, 28-83 years). RFA were performed based on radiographic findings. Needle biopsy was made only twice. Monopolar Cool-tip Tyco or bipolar Celon Olympus radiofrequency devices were used. The procedure was performed under conscious sedation with local anesthesia. Treatment efficacy was assessed by computed tomography and by Doppler ultrasound. The absence of contrast enhancement on computed tomography was considered to be a successful treatment. The average follow up was 14 months (range, 3-36 months). In 42 tumors (93%), total absence of contrast enhancement was obtained after the initial RFA and in three tumors (7%) after the second ablation session. There were no complications following 41 procedures, including all ablations in small (<35 mm) renal masses. In four procedures, minor complications were observed. All patients are alive. There has been no need for chronic hemodialysis and, until now, we have not observed any local recurrences with the exception of one metastasis to an ipsilateral adrenal gland. RFA of kidney tumors is a promising alternative treatment which could be considered for patients who are not suitable for surgery. (author)

Effects of Puff-Adder Venom on Coagulation, Fibrinolysis and ...

African Journals Online (AJOL)

The in vitro and in vivo haematological effects of puffadder (Bitis arietans) venom in the baboon (Papio ursinus) with regard to its effect on coagulation, fibrinolysis and platelet aggregation were studied. There is a delay in the intrinsic coagulation mechanism with fibrinolysis and in vitro fibrinogenolysis. Normal human ...

Direct measurement of the lethal isotherm for radiofrequency ablation of myocardial tissue.

Science.gov (United States)

Wood, Mark; Goldberg, Scott; Lau, Melissa; Goel, Aneesh; Alexander, Daniel; Han, Frederick; Feinstein, Shawn

2011-06-01

The lethal isotherm for radiofrequency catheter ablation of cardiac myocardium is widely accepted to be 50°C, but this has not been directly measured. The purpose of this study was to directly measure the tissue temperature at the edge of radiofrequency lesions in real time using infrared thermal imaging. Fifteen radiofrequency lesions of 6 to 240 seconds in duration were applied to the left ventricular surface of isolated perfused pig hearts. At the end of radiofrequency delivery, a thermal image of the tissue surface was acquired with an infrared camera. The lesion was then stained and an optical image of the lesion was obtained. The thermal and optical images were electronically merged to allow determination of the tissue temperature at the edge of the lesion at the end of radiofrequency delivery. By adjusting the temperature overlay display to conform with the edge of the radiofrequency lesion, the lethal isotherm was measured to be 60.6°C (interquartile ranges, 59.7° to 62.4°C; range, 58.1° to 64.2°C). The areas encompassed by the lesion border in the optical image and the lethal isotherm in the thermal image were statistically similar and highly correlated (Spearman ρ=0.99, Pradiofrequency delivery or to lesion size (both P>0.64). The areas circumscribed by 50°C isotherms were significantly larger than the areas of the lesions on optical imaging (P=0.002). By direct measurement, the lethal isotherm for cardiac myocardium is near 61°C for radiofrequency energy deliveries radiofrequency ablation is important to clinical practice as well as mathematical modeling of radiofrequency lesions.

Level of Radiofrequency (RF) Radiations from GSM Base Stations ...

African Journals Online (AJOL)

Levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located in the vicinity of a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations ...

Distribution functions and moments in the theory of coagulation

International Nuclear Information System (INIS)

Pich, J.

1990-04-01

Different distribution functions and their moments used in the Theory of coagulation are summarized and analysed. Relations between the moments of these distribution functions are derived and the physical meaning of individual moments is briefly discussed. The time evolution of the moment of order zero (total number concentration) during the coagulation process is analysed for the general kernel of the Smoluchowski equation. On this basis the time evolution of certain physically important quantities related to this moment such as mean particle size, surface and volume as well as surface concentration is described. Equations for the half time of coagulation for the general collision frequency factor are derived. (orig.) [de

Radiofrequency ablation of osteoid osteomas: five years experience.

Science.gov (United States)

Papathanassiou, Zafiria G; Petsas, Theodore; Papachristou, Dionysios; Megas, Panagiotis

2011-12-01

The purpose of this study is to retrospectively evaluate the efficacy of radiofrequency ablation as a curative treatment method for benign bone tumours. Twenty-nine osteoid osteomas were treated with radiofrequency ablation. Primary success rate was 89.6% and total secondary success rate was 93.1%. Mean clinical follow-up period was 26.7 months (range: 6-63 months). Statistical analysis of 25 cases of osteoid osteomas with CT follow-up revealed that post-treatment re-ossification does not correlate with clinical outcome (p = 0.14) but is strongly correlated with long-term (> or = 12 months) CT follow-up (p = 0.014). Percutaneous radiofrequency ablation was found to be an effective and safe treatment for osteoid osteomas. CT findings cannot solely differentiate between treatment successes and failures.

Interactions between radiofrequency signals and living organisms

International Nuclear Information System (INIS)

Boudin, F.; Hours, M.; Lacronique, J.F.; Conil, E.; Hadjem, A.; El Habachi, A.; Wiart, K.; Mann, S.; Kundi, M.; Marc-Vergnes, J.P.; Roosli, M.; Mohler, E.; Frei, P.; Davis, Ch.C.; Balzano, Q.; Ait-Aissa, S.; Billaudel, B.; Poulletier De Gannes, F.; Hurtier, A.; Haro, E.; Taxile, M.; Veyret, B.; Lagroye, I.; Ait-Aissa, S.; Poulletier De Gannes, F.; Athane, A.; Veyret, B.; Lagroye, I.; Yardin, C.; Perrin, A.; Freire, M.; Bachelet, Ch.; Collin, A.; Pla, S.; Debouzy, J.C.; Leveque, Ph.; Van Nierop, L.E.; Huss, A.; Roosli, M.; Egger, M.; Calvez, M.; Salomon, D.

2010-01-01

This dossier is composed of 13 articles dealing with the interactions between radio-frequencies and living organisms. It is an overview of various scientific approaches to the field and is of interest for all citizens as the use of mobile phones is widely spread. In the first article it is shown how a model has been built to assess the distribution of the whole body exposure of the population. The second article reviews the state of the art in personal exposure measurements at radio-frequencies. The third article shows that the knowledge of the mechanism of action by which exposure increases the risk of health hazards is necessary. The fourth article shows that individual neuro-psychic factors take a prominent but maybe not unique, part in electromagnetic hypersensitivity. The fifth article shows that no evidence was found to link health disturbances of electromagnetic hypersensitive individuals with radiofrequency exposure. The sixth article shows that the wireless phone is not an athermal hazard to the brain. The seventh article shows that the in utero and post-natal exposure to Wi-Fi does not damage the brains of young rats. The eighth article concludes that recent studies provide no convincing proof of deleterious effects of radiofrequency exposure on the integrity of the blood-brain barrier for specific absorption rates up to 6 W/kg. The ninth article shows that no co-genotoxic effect of radiofrequency was found at levels of exposure that did not induce heating. The tenth article confirms that industry-sponsored studies were least likely to report results suggesting effects. The last article shows that general practitioners are increasingly questioned by their patients about the issue of electromagnetic waves. (A.C.)

A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution

International Nuclear Information System (INIS)

Yilmaz, A. Erdem; Boncukcuoglu, Recep; Kocakerim, M. Muhtar

2007-01-01

This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively

A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution

Energy Technology Data Exchange (ETDEWEB)

Yilmaz, A. Erdem [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey)], E-mail: aerdemy@atauni.edu.tr; Boncukcuoglu, Recep [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey); Kocakerim, M. Muhtar [Atatuerk University, Faculty of Engineering, Department of Chemical Engineering, 25240 Erzurum (Turkey)

2007-10-22

This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively.

Arsenic removal in water by means of coagulation-flocculation processes

International Nuclear Information System (INIS)

Franco, M. F.; Carro P, M. E.

2014-01-01

Arsenic and arsenical compounds are considered as carcinogenic and risky for humans according to epidemiological evidence related with the ingestion of arsenical water during a long period. In many places the only source of drinking water contains arsenic and, therefore, removal strategies have to be investigated. This work shows experimental results of coagulation-flocculation processes implemented to evaluate the efficiency in the removal of arsenic from drinking water. The main objectives include the evaluation of the relevant aspect that controls the removal efficiency. Experimental tests were performed with coagulant concentrations from 5 to 500 mg/L, solid particle concentrations from 0 to 6000 mg/L, and initial arsenic concentrations from 0.5 to 5 mg/L. These variables were simultaneously varied in more than 100 experiments. The efficiency in remediation ranged from 0% to 95%. Removal efficiency near 95% was obtained when using ferric chloride as coagulant, and was close to 80% when using aluminium sulfate as coagulant in arsenate solutions. The remediation efficiency decreased significantly when the ferric chloride concentration was higher than 50 mg/L in relation to the obtained results for aluminum sulfate for different type and concentration of soil particles. The highest removal efficiency were obtained at ph between 3 and 5 in oxidized solutions. Obtained results simulated by means of multiple linear regression analysis (R>0.90) allow determining that the main parameters that control the removal of arsenic from drinking water are coagulant concentration, ph, and solid particles concentration. Conversely, particle mineralogy and coagulant type have less significant effect on the removal by means of coagulation-flocculation mechanisms. Obtained results are relevant for the removal of As in water treatment plants as well as for the development of small scale filters. The samples were studied by scanning electron microscopy and energy dispersive X

Radiofrequency catheter ablation in the treatment of cardiac arrhythmias (first of two parts)

International Nuclear Information System (INIS)

Kou, W.H; Morady, F.

1997-01-01

The intravenous radiofrequency catheter inside cardiac s chambers, for inspect signals intracardiac s and to encourage, has been developed as diagnostic tool with the purpose to search arrhythmias physiology and physiopathology.Many energy sources has been used: direct energy, radiofrequency 11-15, laser 6,17, and microwave 18,19. A comparison between radiofrequency and electric energy shock has been described in cardiac arrhythmias treatment, in the present article. It has been tested the radiation biological effects and risk in Wolff Parkinson White patients as well as doctors who handling the fluoroscopy for image during the radiofrequency ablation. Has been described the following techniques: Catheter ablation radiofrequency slow way and fast way

Effect of THI on milk coagulation properties of Holstein-Friesian dairy cattle

Directory of Open Access Journals (Sweden)

Simone Beux

Full Text Available ABSTRACT The objective of this study was to evaluate the effect of temperature-humidity index (THI on the milk coagulation properties of Holstein-Friesian dairy cattle from northeast part of Italy. A total of 592 individual milk samples from six dairy herds were evaluated. The milk coagulation properties traits analysed were milk rennet coagulation time and curd firmness, as well as the fat, protein, and casein contents, pH, milk aptitude to coagulate (IAC, and the somatic cell count. The THI was determined during the periods of sample collection. The THI results showed that values of up to 75 did not significantly change the IAC values; however, when the THI values were above 75, the IAC decreased significantly. The control of THI can be used to guarantee appropriate milk coagulation properties.

Quality standards for sample collection in coagulation testing.

Science.gov (United States)

Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Lima-Oliveira, Gabriel; Guidi, Gian Cesare; Favaloro, Emmanuel J

2012-09-01

Preanalytical activities, especially those directly connected with blood sample collection and handling, are the most vulnerable steps throughout the testing process. The receipt of unsuitable samples is commonplace in laboratory practice and represents a serious problem, given the reliability of test results can be adversely compromised following analysis of these specimens. The basic criteria for an appropriate and safe venipuncture are nearly identical to those used for collecting blood for clinical chemistry and immunochemistry testing, and entail proper patient identification, use of the correct technique, as well as appropriate devices and needles. There are, however, some peculiar aspects, which are deemed to be particularly critical when collecting quality specimens for clot-based tests, and these require clearer recognition. These include prevention of prolonged venous stasis, collection of nonhemolyzed specimens, order of draw, and appropriate filling and mixing of the primary collection tubes. All of these important preanalytical issues are discussed in this article, and evidence-based suggestions as well as recommendations on how to obtain a high-quality sample for coagulation testing are also illustrated. We have also performed an investigation aimed to identify variation of test results due to underfilling of primary blood tubes, and have identified a clinically significant bias in test results when tubes are drawn at less than 89% of total fill for activated partial thromboplastin time, less than 78% for fibrinogen, and less than 67% for coagulation factor VIII, whereas prothrombin time and activated protein C resistance remain relatively reliable even in tubes drawn at 67% of the nominal volume. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Fast beam radiofrequency spectroscopy

International Nuclear Information System (INIS)

Pipkin, F.M.

1983-01-01

The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles.

Science.gov (United States)

Nguyen, Duy T; Tzou, Wendy S; Zheng, Lijun; Barham, Waseem; Schuller, Joseph L; Shillinglaw, Benjamin; Quaife, Robert A; Sauer, William H

2016-05-01

Remote heating of metal located near a radiofrequency ablation source has been previously demonstrated. Therefore, ablation of cardiac tissue treated with metallic nanoparticles may improve local radiofrequency heating and lead to larger ablation lesions. We sought to evaluate the effect of magnetic nanoparticles on tissue sensitivity to radiofrequency energy. Ablation was performed using an ablation catheter positioned with 10 g of force over prepared ex vivo specimens. Tissue temperatures were measured and lesion volumes were acquired. An in vivo porcine thigh model was used to study systemically delivered magnetically guided iron oxide (FeO) nanoparticles during radiofrequency application. Magnetic resonance imaging and histological staining of ablated tissue were subsequently performed as a part of ablation lesion analysis. Ablation of ex vivo myocardial tissue treated with metallic nanoparticles resulted in significantly larger lesions with greater impedance changes and evidence of increased thermal conductivity within the tissue. Magnet-guided localization of FeO nanoparticles within porcine thigh preps was demonstrated by magnetic resonance imaging and iron staining. Irrigated ablation in the regions with greater FeO, after FeO infusion and magnetic guidance, created larger lesions without a greater incidence of steam pops. Metal nanoparticle infiltration resulted in significantly larger ablation lesions with altered electric and thermal conductivity. In vivo magnetic guidance of FeO nanoparticles allowed for facilitated radiofrequency ablation without direct infiltration into the targeted tissue. Further research is needed to assess the clinical applicability of this ablation strategy using metallic nanoparticles for the treatment of cardiac arrhythmias. © 2016 American Heart Association, Inc.

Application of Moringa Oleifera Seed Powder For Iron (III Coagulation on Local Water Resources

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Fadillah Utami Prasetyaningtyas

2013-07-01

Full Text Available This research aims to know the effect of the use of powder moringa seed to coagulant mass and coagulation process, and its effectiveness to increase the quality of pure water. This research uses factorial research design and statistic test MANOVA. To analyse water quality, the researcher uses Fe parameter.  A graphic of coagulant mass and time for each parameter is used to analyse the data. Based on the research result, the uses of moringa seed as coagulant in each 300 mL mineral water gives a possitives result to the river water sample using 100 mg coagulant mass and sedimentations time for 60 minutes, well water sample using 500 mg coagulant mass and sedimentations time for 60 minutes, tap water sample using 300 mg  coagulant mass and sedimentations time for 90 minutes. The effective coagulant that increase the water quality on well water is 98,32% of moringa seed powder, on river water is 96,64%  and for tap water is 25,62%.

Epicardial, Biatrial Ablation With Integrated Uni-bipolar Radiofrequency Technology in Stand-alone Persistent Atrial Fibrillation.

Science.gov (United States)

Rosati, Fabrizio; Muneretto, Claudio; Merati, Elisa; Polvani, Gianluca; Moltrasio, Massimo; Tondo, Claudio; Curnis, Antonio; Cerini, Manuel; Metras, Alexandre; Bisleri, Gianluigi

Although minimally invasive approaches for surgical treatment of stand-alone atrial fibrillation have gained popularity for the past decade, ablation technology and extensive lesion sets play a major role in the achievement of a successful procedure, especially in presence of persistent and long-standing persistent atrial fibrillation. We evaluated clinical outcomes after totally endoscopic biatrial epicardial ablation of persistent atrial fibrillation with a novel integrated uni-bipolar radiofrequency device. Forty-nine (49) consecutive patients with stand-alone atrial fibrillation underwent right-sided monolateral thoracoscopic surgical ablation with a novel integrated uni-bipolar radiofrequency energy delivery and temperature-controlled technology. Atrial fibrillation was persistent in 13 (26.5%) of 49 and long-standing persistent in 36 (73.5%) of 49 patients. Mean ± SD age was 60.6 ± 10.3 years. Median duration of atrial fibrillation was 74 months. Mean ± SD left atrial diameter was 44.7 ± 4.0 mm. Epicardial en bloc isolation of all pulmonary veins (box lesion) and additional ablation of the right atrial free wall was successfully performed via minimally invasive approach without any intraoperative and postoperative major complications. Intraoperative entrance and exit block was achieved in 77.5% (38/49) and 91.8% (45/49) of patients, respectively. Mean ± SD ablation time was 16.3 ± 4.8 minutes. No intensive care unit stay was required. Postoperative sinus rhythm was achieved in 93.8% (30/32) patients, and no pacemaker implantation was required. At 13 months, 87.7% (43/49) of patients were in sinus rhythm; 71.4% (35/49) were free from antiarrhythmic drugs and 75.5% (37/49) from oral anticoagulation. Integrated uni-bipolar radiofrequency ablation technology showed to be effective for the surgical treatment of atrial fibrillation with a total endoscopic approach. A versapolar suction device with extensive right-left atrial lesion set may further improve

Influential factors of formation kinetics of flocs produced by water treatment coagulants.

Science.gov (United States)

Wu, Chunde; Wang, Lin; Hu, Bing; Ye, Jian

2013-05-01

The growth rate and size of floc formation is of great importance in water treatment especially in coagulation process. The floc formation kinetics and the coagulation efficiency of synthetic water were investigated by using an on-line continuous optical photometric dispersion analyze and the analysis of water quality. Experimental conditions such as alum dosage, pH value for coagulation, stirring intensity and initial turbidity were extensively examined. The photometric dispersion analyze results showed that coagulation of kaolin suspensions with two coagulants (alum and polyaluminium chloride) could be taken as a two-phase process: slow and rapid growth periods. Operating conditions with higher coagulant doses, appropriate pH and average shear rate might be particularly advantageous. The rate of overall floc growth was mainly determined by a combination of hydraulic and water quality conditions such as pH and turbidity. The measurement of zeta potential indicates that polyaluminium chloride exhibited higher charge-neutralizing ability than alum and achieved lower turbidities than alum for equivalent Al dosages. Under the same operating conditions, the alum showed a higher grow rate, but with smaller floc size.

Percutaneous radiofrequency treatment for refractory anteromedial pain of osteoarthritic knees.

Science.gov (United States)

Ikeuchi, Masahiko; Ushida, Takahiro; Izumi, Masashi; Tani, Toshikazu

2011-04-01

Although severe knee osteoarthritis with refractory pain is commonly treated surgically, this is often not an option for patients with poor health status or unwillingness to undergo major surgery. We examined the efficacy of radiofrequency application to sensory nerves as a novel alternative treatment for refractory knee pain. This study was an open-label, nonrandomized, and controlled study. Patients complaining of refractory anteromedial knee pain associated with radiological osteoarthritis (moderate or severe) were included. They were assigned to one of two groups: those receiving radiofrequency thermocoagulation (N = 18) or those receiving nerve block (N = 17), depending on the time period that they were referred to the clinic. Radiofrequency current or local anesthetics was applied to the medial retinacular nerve and the infrapatellar branch of the saphenous nerve. Western Ontario McMaster Universities osteoarthritis index score, pain visual analog scale (VAS), and patient's global assessment were assessed with a minimum follow-up of 6 months.   Radiofrequency treatment significantly decreased knee pain as measured by VAS for 12 weeks compared with the control group. In terms of responders, more patients in the RF group responded to the treatment than in the control group. The differences were statistically significant at 4 weeks, 8 weeks, and 12 weeks in pain VAS. Eight patients (44%) treated with radiofrequency rated excellent or good but only three (18%) in the control group rated good, although the difference was not statistically significant. Some patients were able to benefit substantially from radiofrequency treatment. Even if its effective period is limited, radiofrequency application is a promising treatment to alleviate refractory anteromedial knee pain with osteoarthritis. Further experience and technical improvements are needed to establish its role in the management of knee osteoarthritis. Wiley Periodicals, Inc.

Coagulation-flocculation studies of laboratory wastewater using different combinations

International Nuclear Information System (INIS)

Butt, M. T.; Khan, R. A.; Khokar, A.; Iqbal, K.

2013-01-01

This study was conducted on the wastewater of PCSIR Laboratories complex Lahore. Both single as well as blended form was used in order to achieve maximum results and to reduce the cost. These experiments were conducted in Hudson Jars of one liter capacity using the coagulation technique for the removal of total suspended solids (TSS) and turbidity. The pH range was 6-8 and 4-10 for treatment. Four coagulants were used such as FeCl 3 , AlCl 3 . Alum and FeSO 4 , to remove the turbidity in single and blended form. Results of single coagulant are FeCl 3 from 39.7 to 11.51 NTU; AlCl 3 from 47.48 to 11.8 NTU. Alum 43 to 25.3NTU.FeSO 4 showed increasing trend in turbidity 53 to 120 NTU. The blended set of coagulants AlCl 3 +Alum turbidity from 45 to 18.55 NTU. The AlCl 3 and FeCl 3 showed almost similar results but after overnight settling results were excellent and alum showed also good results. The turbidity was removed from 54 to 27 NTU, 48 to 22 NTU, 44 to 17 NTU, and after overnight settling 33 to 4 NTU. The results of blended coagulants FeCl 3 +AlCl 3 after one, two and three hours settling were also studied and found best and blend AlCl3+Alum showed also similar trend and the blend of Alum+FeCl 3 after overnight settling was excellent. The same coagulants and its blended form were used for TSS removal and results are 278 to 7 mg/L, in blended form AlCl 3 +Alum show similar results but Alum + FeCl 3 showed excellent results. The TSS and turbidity removal was 87%, 97.5%. (author)

Treatment of Refractory Idiopathic Supraorbital Neuralgia Using Percutaneous Pulsed Radiofrequency.

Science.gov (United States)

Luo, Fang; Lu, Jingjing; Ji, Nan

2018-02-26

No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who do not respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients. We prospectively investigated the long-term effects of ultrasound-guided percutaneous pulsed radiofrequency in the treatment of 22 refractory idiopathic supraorbital neuralgia patients. A reduction in the verbal pain numeric rating scale score of more than 50% was used as the standard of effectiveness. The effectiveness rates at different time points within 2 years were calculated. After a single pulsed radiofrequency treatment, the effectiveness rate at 1 and 3 months was 77%, and the rates at 6 months, 1 year, and 2 years were 73%, 64%, and 50%, respectively. Except for a small portion of patients (23%) who experienced mild upper eyelid ecchymosis that gradually disappeared after approximately 2 weeks, no obvious complications were observed. In conclusion, the results of our study demonstrate that for patients with refractory idiopathic supraorbital neuralgia, percutaneous pulsed radiofrequency may be an effective and safe treatment choice. © 2018 World Institute of Pain.

Percutaneous radiofrequency treatment of osteoid osteoma using cool-tip electrodes

Energy Technology Data Exchange (ETDEWEB)

Martel, Jose [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Avda. de Budapest s/n, 28922 Alcorcon, Madrid (Spain)]. E-mail: jmartel@fhalcorcon.es; Bueno, Angel [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Avda. de Budapest s/n, 28922 Alcorcon, Madrid (Spain); Ortiz, Eduardo [Departamento de Cirugia ortopedica, Fundacion Hospital Alcorcon, Madrid (Spain)

2005-12-15

Objectives: To report our experience with percutaneous cool-tip radiofrequency ablation of osteoid osteomas and to evaluate clinical outcome. Methods and material: Forty-one patients with clinically and radiologically suspected osteoid osteoma were seen over a 48-month period (27 males and 14 females with a mean age of 18.7 years; range 5-43 years). Thirty-eight patients were treated by computed tomography (CT)-guided percutaneous radiofrequency ablation. The procedure was performed under regional or general anaesthesia. After location of the nidus, a 14G-bone biopsy needle is introduced into the nidus. Sampling is performed with a 17G-bone biopsy needle using a coaxial technique. The radiofrequency needle with a 10 mm active tip (cool-tip) is inserted through the biopsy needle and is connected to the radiofrequency generator for 6-8 min. Results: Primary success was obtained in 37 patients (97%) with a 100% secondary success rate. All patients are currently pain-free. No major complications occurred. Patients could resume unrestricted normal activity within 24 h. Conclusions: Percutaneous radiofrequency ablation of osteoid osteomas is an efficient and safe method that can be considered the procedure of choice for most cases.

Evaluation of Chitin as Natural Coagulant in Water Treatment

Directory of Open Access Journals (Sweden)

V. Saritha

2012-04-01

Full Text Available The use of synthetic coagulants is not regarded as suitable due to health and economic considerations. The present study was aimed to investigate the effects of alum as coagulant in conjunction with chitin as coagulant aid on the removal of turbidity, hardness and Escherichia coli from water. A conventional jar test apparatus was employed for the tests. The experiment was conducted at three different pH conditions of 6, 7 and 8. The dosages chosen were 0.5, 1, 1.5 and 2mg/l. The results showed that turbidity decrease provided also a primary Escherichia coli reduction. Hardness removal efficiency was observed to be 93% at pH 7 with 1mg/l concentration by alum whereas chitin was stable at all the pH ranges showing highest removal at 1 and 1.5mg/l with pH 7. At low concentration chitin showed marginally better performance on hardness. In conclusion, using natural coagulants results in considerable savings in chemicals and sludge handling cost may be achieved.

Use of non-Conventional Material to Remove Cu+2 ions from Aqueous Solutions using Chemical Coagulation

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Muna Yousif Abdul. Ahad

2015-05-01

Full Text Available Coagulation - flocculation are basic chemical engineering method in the treatment of metal-bearing industrial wastewater because it removes colloidal particles, some soluble compounds and very fine solid suspensions initially present in the wastewater by destabilization and formation of flocs. This research was conducted to study the feasibility of using natural coagulant such as okra and mallow and chemical coagulant such as alum for removing Cu and increase the removal efficiency and reduce the turbidity of treated water. Fourier transform Infrared (FTIR was carried out for okra and mallow before and after coagulant to determine their type of functional groups. Carbonyl and hydroxyl functional groups on the surface of okra and mallow were the major groups responsible for coagulation process. By using alum (conventional coagulants, okra and mallow (as a primary coagulant or in combination with the other two primary coagulants and by the jar testing, the optimum pH-value and dose of the coagulants were determined. The results indicated that the optimal pH values were 6.7, 8 and 6 for alum, okra and mallow, respectively. Mathematical modeling show significant results (sig.<0.05 for the % Cu removal (dependent variable with respect to coagulant dose (independent variable for the okra as a primary coagulant, alum with okra and alum with mallow as binary coagulants and alum, okra and mallow as ternary coagulants .

Coagulation of highly turbid suspensions using magnesium hydroxide: effects of slow mixing conditions.

Science.gov (United States)

Ayoub, George M; BinAhmed, Sara W; Al-Hindi, Mahmoud; Azizi, Fouad

2014-09-01

Laboratory experiments were carried out to study the effects of slow mixing conditions on magnesium hydroxide floc size and strength and to determine the turbidity and total suspended solid (TSS) removal efficiencies during coagulation of highly turbid suspensions. A highly turbid kaolin clay suspension (1,213 ± 36 nephelometric turbidity units (NTU)) was alkalized to pH 10.5 using a 5 M NaOH solution; liquid bittern (LB) equivalent to 536 mg/L of Mg(2+) was added as a coagulant, and the suspension was then subjected to previously optimized fast mixing conditions of 100 rpm and 60 s. Slow mixing speed (20, 30, 40, and 50 rpm) and time (10, 20, and 30 min) were then varied, while the temperature was maintained at 20.7 ± 1 °C. The standard practice for coagulation-flocculation jar test ASTM D2035-13 (2013) was followed in all experiments. Relative floc size was monitored using an optical measuring device, photometric dispersion analyzer (PDA 2000). Larger and more shear resistant flocs were obtained at 20 rpm for both 20- and 30-min slow mixing times; however, given the shorter duration for the former, the 20-min slow mixing time was considered to be more energy efficient. For slow mixing camp number (Gt) values in the range of 8,400-90,000, it was found that the mixing speed affected floc size and strength more than the time. Higher-turbidity removal efficiencies were achieved at 20 and 30 rpm, while TSS removal efficiency was higher for the 50-rpm slow mixing speed. Extended slow mixing time of 30 min yielded better turbidity and TSS removal efficiencies at the slower speeds.

A personal radio-frequency dosimeter with cumulative-dose recording capabilities

International Nuclear Information System (INIS)

Rochelle, R.W.; Moore, M.R.; Thomas, R.S.; Ewing, P.D.; Hess, R.A.; Hoffheins, B.S.

1990-01-01

The radio-frequency (rf) dosimeter developed by the Oak Ridge National Laboratory is a portable, pocket-sized cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. Features of the rf dosimeter include a frequency range of 30 MHz to 10 GHz and a three-dimensional sensor. Data obtained with the rf dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to 6 months, after which the data are transferred to a computer via the dosimeter's serial port. The rf dosimeter should increase knowledge of the levels of electric fields to which individuals are exposed. 13 refs., 16 figs., 2 tabs

Blood coagulation factor VIII

Indian Academy of Sciences (India)

Factor VIII (FVIII) functions as a co-factor in the blood coagulation cascade for the proteolytic activation of factor X by factor IXa. Deficiency of FVIII causes hemophilia A, the most commonly inherited bleeding disorder. This review highlights current knowledge on selected aspects of FVIII in which both the scientist and the ...

Effect of radiofrequency on capacitance of low density plasma sheath

International Nuclear Information System (INIS)

Carneiro, L.T.; Cunha Rapozo, C. da

1988-01-01

It is shown that the influence of induced radiofrequency potential (V RF ) modifies the Bohm theory on ion saturation current, measured with Langmuir probes. The effect of radiofrequency potential on diode type plasma sheath resonance is also investigated. (M.C.K.)

Removal of algal blooms from freshwater by the coagulation-magnetic separation method.

Science.gov (United States)

Liu, Dan; Wang, Peng; Wei, Guanran; Dong, Wenbo; Hui, Franck

2013-01-01

This research investigated the feasibility of changing waste into useful materials for water treatment and proposed a coagulation-magnetic separation technique. This technique was rapid and highly effective for clearing up harmful algal blooms in freshwater and mitigating lake eutrophication. A magnetic coagulant was synthesized by compounding acid-modified fly ash with magnetite (Fe(3)O(4)). Its removal effects on algal cells and dissolved organics in water were studied. After mixing, coagulation, and magnetic separation, the flocs obtained from the magnet surface were examined by SEM. Treated samples were withdrawn for the content determination of chlorophyll-a, turbidity, chemical oxygen demand (COD), total nitrogen, and total phosphorus. More than 99 % of algal cells were removed within 5 min after the addition of magnetic coagulant at optimal loadings (200 mg L(-1)). The removal efficiencies of COD, total nitrogen, and phosphorus were 93, 91, and 94 %, respectively. The mechanism of algal removal explored preliminarily showed that the magnetic coagulant played multiple roles in mesoporous adsorption, netting and bridging, as well as high magnetic responsiveness to a magnetic field. The magnetic-coagulation separation method can rapidly and effectively remove algae from water bodies and greatly mitigate eutrophication of freshwater using a new magnetic coagulant. The method has good performance, is low cost, can turn waste into something valuable, and provides reference and directions for future pilot and production scale-ups.

PILOT PLANT STUDY ON NATURAL WATER COAGULANTS AS COAGULAN AIDS FOR WATER SUPPLY

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B BINA

2001-06-01

Full Text Available Introduction: Natural plant coagulants have an important role to play in provision of portable water to rural communities in the developing world. The plant material that their coagulation properties have been confirmed in previous lab scale studies and can be found widely in Iran was selected as coagulant aids. Pilot plant study was done to evaluate the efficiency of natural material such as Starch/Gum Tragacanth, Fenugreek and Yeast as coagulant aids in conjunction with comercial alum. Methods: The pilot was placed in Isfahan Water Treatment Plant (IWTP and efficiency of these materials in removal of turbidity from raw water enters the IWTP was evaluated. The results indicated while these materials were used as coagulant aids in concentration of 1-5 mg/l conjunction with alum are able to reduced the turbidity and final residuals turbidity meets the standards limits. Results: The coagulation efficiency of these material were found to be effected by certain physico-chemical factors, namely, concentration of suspended solids, divalent cation metal and time of agitation. The relative importance of these variable was evaluated. The results of COD test proved that the natural coagulant aids in the optimum doses produce no any significant organic residual. Discussion: Economical considerations showed that using of these material as coagulant aids can cause reduction in alum consumption and in some cases are more econmical than synthetic polyelectrolyte.

Eye examinations of laser and radiofrequency radiation workers

International Nuclear Information System (INIS)

Hocking, B.

1988-01-01

There are a growing number of uses of lasers and radiofrequency radiation in industry. Because these radiations may lead to various ocular effects, examinations of the eye are required for laser and radiofrequency workers as part of safe working practices. Various issues concerning these examinations are raised for discussion including: handling personal data, placement criteria, data collection, quality control, control data, the load on service providers, and costs

Bray–Liebhafsky oscillatory reaction in the radiofrequency electromagnetic field

Energy Technology Data Exchange (ETDEWEB)

Stanisavljev, Dragomir R., E-mail: dragisa@ffh.bg.ac.rs [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 473, 11001 Belgrade (Serbia); Velikić, Zoran [Institute of Physics, University of Belgrade, Pregrevica 118, Zemun (Serbia); Veselinović, Dragan S.; Jacić, Nevena V.; Milenković, Maja C. [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 473, 11001 Belgrade (Serbia)

2014-09-30

Highlights: • Oscillatory Bray–Liebhafsky reaction is coupled with the radiofrequency radiation. • The effects of radiofrequency field on oscillatory parameters are investigated. • Radiofrequency power of up to the 0.2 W did not produced observable changes. • The explanation related with dissipative and capacitive effects is given. • Open the possibility of investigations of reactive effects on biological systems. - Abstract: Oscillatory Bray–Liebhafsky (BL) reaction is capacitively coupled with the electromagnetic radiation in the frequency range 60–110 MHz. Because of the specific reaction dynamics characterized by several characteristic parameters (induction period, period between chemical oscillations and their amplitude) it served as a good model system for the investigation of the effects of radiofrequent (RF) radiation. RF power of up to 0.2 W did not produce observable changes of the BL reaction parameters in the limit of the experiment reproductivity. Results indicate that, under the given experimental conditions, both dissipative and reactive properties of the solution are not considerably coupled with the RF electrical field.

A new inorganic-organic composite coagulant, consisting of polyferric sulphate (PFS) and polyacrylamide (PAA).

Science.gov (United States)

Moussas, P A; Zouboulis, A I

2009-08-01

Currently, research is focused on the synthesis of new composite coagulants, which are constituted of both inorganic and organic materials. In this paper, the development of relevant reagents was investigated, by combining the inorganic pre-polymerised iron-based coagulant Polyferric Sulphate (PFS) with an organic, non-ionic polymer (Polyacrylamide, PAA) under different PAA/Fe (mg/l) and OH/Fe molar ratios. Moreover, the new reagents were characterised in terms of typical properties, stability and morphological analysis (XRD, FTIR, SEM). Their coagulation performance, when treating low or high turbid kaolin-humic acid suspensions, was also investigated, whereas the applied coagulation mechanisms were discussed by using the Photometric Dispersion Analysis (PDA) analysis. The results show that the new coagulation reagents present improved properties, including increased effective polymer species concentration, and they exhibit very good stability. The respective tests using PDA confirmed that the predominant coagulation mechanism of PFS-PAA is the bridge formation mechanism. Coagulation experiments in low or high turbid kaolin-humic acid suspensions reveal that the novel composite reagent PFS-PAA exhibits better coagulation performance, when compared with simple PFS, in terms of zeta-potential reduction, turbidity and organic matter removal and residual iron concentration.

Exact combinatorial approach to finite coagulating systems

Science.gov (United States)

Fronczak, Agata; Chmiel, Anna; Fronczak, Piotr

2018-02-01

This paper outlines an exact combinatorial approach to finite coagulating systems. In this approach, cluster sizes and time are discrete and the binary aggregation alone governs the time evolution of the systems. By considering the growth histories of all possible clusters, an exact expression is derived for the probability of a coagulating system with an arbitrary kernel being found in a given cluster configuration when monodisperse initial conditions are applied. Then this probability is used to calculate the time-dependent distribution for the number of clusters of a given size, the average number of such clusters, and that average's standard deviation. The correctness of our general expressions is proved based on the (analytical and numerical) results obtained for systems with the constant kernel. In addition, the results obtained are compared with the results arising from the solutions to the mean-field Smoluchowski coagulation equation, indicating its weak points. The paper closes with a brief discussion on the extensibility to other systems of the approach presented herein, emphasizing the issue of arbitrary initial conditions.

Vegetable coagulants as alternative for treatment of wastewater in Mexico

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Servando López-León

2017-11-01

Full Text Available This review addresses the various properties of natural coagulants, water, the chemical substance essential for life and the ideal solvent for a large number of compounds, it is commonly used with domestic, commercial and industrial purposes. After its use, it presents sewage to be retired before use it once again. To remove pollutant, water is subject to different physical, chemical and biological processes. Here, the clarification process uses aluminum and iron materials to remove the solids present; these materials are reported as health hazardous and toxic. In Mexico, regulatory frame work stablish that treated wastewater should do not exceed 0.2 mg/L of aluminum even though has been reported an increased risk of Alzheimer's in populations when water exceeds 0.1 mg/L. Natural coagulants have showed coagulation properties when are used in the clarification process, proven its advantages over traditional ones; such as low cost, good coagulant properties and safe health and non-toxic properties. Here, we enlist some vegetable species as alternatives to the traditional based on aluminum and iron. Additionally, these species are known to have origins on Mexico or being present extensively in the territory, making possible to think about them as alternative coagulants in the clarification process of the wastewater treatment process.

Percutaneous radiofrequency ablation for benign nodules of the thyroid gland

International Nuclear Information System (INIS)

Baek, Jung Hwan; Jeong, Hyun Jo; Kim, Yoon Suk; Kwak, Min Sook; Chang, Sun Hee; Rhim, Hyun Chul

2005-01-01

We wanted to evaluate the efficacy and safety of using ultrasound guided percutaneous radiofrequency ablation for the benign nodules of the thyroid gland. We studied 148 patients with benign thyroid nodules (200 total nodules) that were confirmed histopathologically, and we performed ultrasound guided radiofrequency ablation. The radiofrequency ablation was done 1 to 5 times per one nodule, and follow-up ultrasonography was performed one to nineteen months after the ablation procedures. The physical changes and the decrease of volume of the nodules were evaluated, and the complications related to radiofrequency ablation were observed. The mean initial nodule volume was 0.01-95.61 ml (mean; 6.83 ± SD of 10.63 ml) and the nodule volume after radiofrequency ablation was decreased to 0.00-46.56 ml (mean; 1.83 ± SD of 4.69 ml). The mean volume reduction rate was 73.2%. Reduction of more than 50% was noted in 90% of all cases. For 180 nodules (90%), the decrease was 50% or more, in 20 nodules (10%), the decrease was 49% or less. On gray-scale ultrasonogram obtained after ablation, the echogenicity of the nodules changed to darker, and on the doppler-sonogram, the vascular flow within the nodules disappeared in all cases. Most patients complained pain during or right after the procedure, but the pain was transient and subsided after medication. Two patients developed hoarseness that was improved in 1 week and 2 months, respectively. Sonoguided percutaneous radiofrequency ablation can be one of the treatments for benign nodules of the thyroid gland

Hemocompatibility of Axial Versus Centrifugal Pump Technology in Mechanical Circulatory Support Devices.

Science.gov (United States)

Schibilsky, David; Lenglinger, Matthias; Avci-Adali, Meltem; Haller, Christoph; Walker, Tobias; Wendel, Hans Peter; Schlensak, Christian

2015-08-01

The hemocompatible properties of rotary blood pumps commonly used in mechanical circulatory support (MCS) are widely unknown regarding specific biocompatibility profiles of different pump technologies. Therefore, we analyzed the hemocompatibility indicating markers of an axial flow and a magnetically levitated centrifugal device within an in vitro mock loop. The HeartMate II (HM II; n = 3) device and a CentriMag (CM; n = 3) adult pump were investigated in a human whole blood mock loop for 360 min using the MCS devices as a driving component. Blood samples were analyzed by enzyme-linked immunosorbent assay for markers of coagulation, complement system, and inflammatory response. There was a time-dependent activation of the coagulation (thrombin-antithrombin complexes [TAT]), complement (SC5b-9), and inflammation system (polymorphonuclear [PMN] elastase) in both groups. The mean value of TAT (CM: 4.0 μg/L vs. 29.4 μg/L, P technologies and a magnetically levitated centrifugal pump design might be superior. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals Inc.

Knee cooled radiofrequency vs continuous radiofrequency for genicular neurotomy: preliminary experience - Crio-radiofrequenza vs radiofrequenza continua per neurotomia dei nervi genicolati: esperienza preliminare

Directory of Open Access Journals (Sweden)

Alfonso Papa

2016-09-01

Full Text Available Radiofrequency neurotomy of genicular nerves has been often used as an efficacious treatment option in all patients suffering from chronic osteoarthritis pain to provide long-term pain relief. After providing informed written consent, 80 patients with severe knee chronic osteoarthritis pain had been enrolled; patients had been divided into two groups (Group C, crioneurolysis, vs Group R, traditional radiofrequency, 40 patients for each group. Pain relief in C group was poorer and with shorter time in duration (median NRS reducing from 8 to 5. Radiofrequency can be considered as an effective, minimally invasive treat­ment for these kinds of conditions, and offers the benefit of being a fast procedure with long-term pain relief.

Reduction of Turbidity of Water Using Locally Available Natural Coagulants

Science.gov (United States)

Asrafuzzaman, Md.; Fakhruddin, A. N. M.; Hossain, Md. Alamgir

2011-01-01

Turbidity imparts a great problem in water treatment. Moringa oleifera, Cicer arietinum, and Dolichos lablab were used as locally available natural coagulants in this study to reduce turbidity of synthetic water. The tests were carried out, using artificial turbid water with conventional jar test apparatus. Optimum mixing intensity and duration were determined. After dosing water-soluble extracts of Moringa oleifera, Cicer arietinum, and Dolichos lablab reduced turbidity to 5.9, 3.9, and 11.1 nephelometric turbidity unit (NTU), respectively, from 100 NTU and 5, 3.3, and 9.5, NTU, respectively, after dosing and filtration. Natural coagulants worked better with high, turbid, water compare to medium, or low, turbid, water. Highest turbidity reduction efficiency (95.89%) was found with Cicer arietinum. About 89 to 96% total coliform reduction were also found with natural coagulant treatment of turbid water. Using locally available natural coagulants, suitable, easier, and environment friendly options for water treatment were observed. PMID:23724307

Multiple roles of the coagulation protease cascade during virus infection.

Science.gov (United States)

Antoniak, Silvio; Mackman, Nigel

2014-04-24

The coagulation cascade is activated during viral infections. This response may be part of the host defense system to limit spread of the pathogen. However, excessive activation of the coagulation cascade can be deleterious. In fact, inhibition of the tissue factor/factor VIIa complex reduced mortality in a monkey model of Ebola hemorrhagic fever. Other studies showed that incorporation of tissue factor into the envelope of herpes simplex virus increases infection of endothelial cells and mice. Furthermore, binding of factor X to adenovirus serotype 5 enhances infection of hepatocytes but also increases the activation of the innate immune response to the virus. Coagulation proteases activate protease-activated receptors (PARs). Interestingly, we and others found that PAR1 and PAR2 modulate the immune response to viral infection. For instance, PAR1 positively regulates TLR3-dependent expression of the antiviral protein interferon β, whereas PAR2 negatively regulates expression during coxsackievirus group B infection. These studies indicate that the coagulation cascade plays multiple roles during viral infections.

Mechanisms for enlarging lesion size during irrigated tip radiofrequency ablation

DEFF Research Database (Denmark)

Petersen, Helen Høgh; Roman-Gonzalez, Javier; Johnson, Susan B

2004-01-01

INTRODUCTION: Irrigated tip radiofrequency ablation of cardiac arrhythmias was developed to increase the size of the radiofrequency-induced lesion, since cooling of the electrode tip allows use of higher power settings. The purpose of this study was to determine if the increased lesion size during...

Paying attention to radiofrequency ablation therapy for neoplasms

International Nuclear Information System (INIS)

Wang Zhongming; Li Linsun

2010-01-01

Radiofrequency ablation is an effective treatment for malignant tumors. With the development of imaging technique, it has been widely used in treating different kinds of malignant tumors, such as liver cancer, lung cancer, kidney carcinoma, etc. Radiofrequency ablation has a lot of advantages. As a minimally-invasive, safe and effective treatment with less sufferings and fewer complications, this technique has attracted more and more attention of the experts both at home and abroad. (authors)

Microwave Ablation Compared with Radiofrequency Ablation for Breast Tissue in an Ex Vivo Bovine Udder Model

International Nuclear Information System (INIS)

Tanaka, Toshihiro; Westphal, Saskia; Isfort, Peter; Braunschweig, Till; Penzkofer, Tobias; Bruners, Philipp; Kichikawa, Kimihiko; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2012-01-01

Purpose: To compare the effectiveness of microwave (MW) ablation with radiofrequency (RF) ablation for treating breast tissue in a nonperfused ex vivo model of healthy bovine udder tissue. Materials and Methods: MW ablations were performed at power outputs of 25W, 35W, and 45W using a 915-MHz frequency generator and a 2-cm active tip antenna. RF ablations were performed with a bipolar RF system with 2- and 3-cm active tip electrodes. Tissue temperatures were continuously monitored during ablation. Results: The mean short-axis diameters of the coagulation zones were 1.34 ± 0.14, 1.45 ± 0.13, and 1.74 ± 0.11 cm for MW ablation at outputs of 25W, 35W, and 45W. For RF ablation, the corresponding values were 1.16 ± 0.09 and 1.26 ± 0.14 cm with electrodes having 2- and 3-cm active tips, respectively. The mean coagulation volumes were 2.27 ± 0.65, 2.85 ± 0.72, and 4.45 ± 0.47 cm 3 for MW ablation at outputs of 25W, 35W, and 45W and 1.18 ± 0.30 and 2.29 ± 0.55 cm 3 got RF ablation with 2- and 3-cm electrodes, respectively. MW ablations at 35W and 45W achieved significantly longer short-axis diameters than RF ablations (P < 0.05). The highest tissue temperature was achieved with MW ablation at 45W (P < 0.05). On histological examination, the extent of the ablation zone in MW ablations was less affected by tissue heterogeneity than that in RF ablations. Conclusion: MW ablation appears to be advantageous with respect to the volume of ablation and the shape of the margin of necrosis compared with RF ablation in an ex vivo bovine udder.

Coagulation-flocculation studies of wastewaters

NARCIS (Netherlands)

Leentvaar, J.

1982-01-01

Although coagulation-flocculation processes have been practiced world-wide for almost a century in water treatment, several problems both in the theoretical and in the applied field have not been resolved yet. Especially interpretation of practical results with respect to governing

Cosmetic wastewater treatment by coagulation and advanced oxidation processes.

Science.gov (United States)

Naumczyk, Jeremi; Bogacki, Jan; Marcinowski, Piotr; Kowalik, Paweł

2014-01-01

In this study, the treatment process of three cosmetic wastewater types has been investigated. Coagulation allowed to achieve chemical oxygen demand (COD) removal of 74.6%, 37.7% and 74.0% for samples A (Al2(SO4)3), B (Brentafloc F3) and C (PAX 16), respectively. The Fenton process proved to be effective as well - COD removal was equal to 75.1%, 44.7% and 68.1%, respectively. Coagulation with FeCl3 and the subsequent photo-Fenton process resulted in the best values of final COD removal equal to 92.4%, 62.8% and 90.2%. In case of the Fenton process, after coagulation these values were equal to 74.9%, 50.1% and 84.8%, while in case of the H2O2/UV process, the obtained COD removal was 83.8%, 36.2% and 80.9%. High value of COD removal in the Fenton process carried out for A and C wastewater samples was caused by a significant contribution of the final neutralization/coagulation. Very small effect of the oxidation reaction in the Fenton process in case of sample A resulting from the presence of antioxidants, 'OH radical scavengers' in the wastewater.

Treatment of melanoidin wastewater by anaerobic digestion and coagulation.

Science.gov (United States)

Arimi, Milton M; Zhang, Yongjun; Götz, Gesine; Geißen, Sven-Uwe

2015-01-01

Melanoidins are dark-coloured recalcitrant pollutants found in many industrial wastewaters including coffee-manufacturing effluent, molasses distillery wastewater (MDWW) and other wastewater with molasses as the raw material. The wastewaters are mostly treated with anaerobic digestion after some dilution to minimize the inhibition effect. However, the dark colour and recalcitrant dissolved organic carbon (DOC) mainly caused by melanoidin are not effectively removed. The aim of this study was to investigate the removal of colour and remnant DOC by different coagulants from anaerobically digested MDWW. From the six coagulants tested, ferric chloride had the highest melanoidin (48%), colour (92.7%) and DOC (63.3%) removal at pH 5 and a dosage of 1.6 g/l. Both polymer and inorganic salt coagulants tested had optimal colour, melanoidin and DOC removal at acidic pH. The molecular size distribution of synthetic melanoidins by liquid chromatography-organic carbon detection indicated a preferential removal of high-molecular-weight melanoidins over low weight melanoidins by the coagulation. Further studies should focus on how to improve biodegradability of the treated effluent for it to be reused as dilution water for anaerobic digestion.

Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review.

Science.gov (United States)

Sillanpää, Mika; Ncibi, Mohamed Chaker; Matilainen, Anu; Vepsäläinen, Mikko

2018-01-01

Natural organic matter (NOM) is a complex matrix of organic substances produced in (or channeled to) aquatic ecosystems via various biological, geological and hydrological cycles. Such variability is posing a serious challenge to most water treatment technologies, especially the ones designed to treat drinking water supplies. Lately, in addition to the fluctuating composition of NOM, a substantial increase of its concentration in fresh waters, and also municipal wastewater effluents, has been reported worldwide, which justifies the urgent need to develop highly efficient and versatile water treatment processes. Coagulation is among the most applied processes for water and wastewater treatment. The application of coagulation to remove NOM from drinking water supplies has received a great deal of attention from researchers around the world because it was efficient and helped avoiding the formation of disinfection by products (DBPs). Nonetheless, with the increased fluctuation of NOM in water (concentration and composition), the efficiency of conventional coagulation was substantially reduced, hence the need to develop enhanced coagulation processes by optimizing the operating conditions (mainly the amount coagulants and pH), developing more efficient inorganic or organic coagulants, as well as coupling coagulation with other water treatment technologies. In the present review, recent research studies dealing with the application of coagulation for NOM removal from drinking water supplies are presented and compared. In addition, integration schemes combining coagulation and other water treatment processes are presented, including membrane filtration, oxidation, adsorption and others processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review of Coagulation Technology for Removal of Arsenic: Case of Chile

OpenAIRE

Sancha, Ana María

2006-01-01

Coagulation technology has been used since 1970 in northern Chile for removing arsenic from drinking-water. This experience suggests that coagulation is an effective technology for the removal of arsenic. It is currently possible to reduce arsenic from 400 μg/L to 10 μg/L at a rate of 500 L/sec, assuming pH, oxidizing and coagulation agents are strictly controlled. The Chilean experience with the removal of arsenic demonstrates that the water matrix dictates the selection of the arsenic-remov...

Impact of cavitron ultrasonic surgical aspirator (CUSA) and bipolar radiofrequency device (Habib-4X) based hepatectomy for hepatocellular carcinoma on tumour recurrence and disease-free survival.

Science.gov (United States)

Huang, Kai-Wen; Lee, Po-Huang; Kusano, Tomokazu; Reccia, Isabella; Jayant, Kumar; Habib, Nagy

2017-11-07

The aim of this study was to evaluate the oncological outcomes of hepatocellular carcinoma patients undergoing liver resection using cavitron ultrasonic surgical aspirator (CUSA) or radiofrequency (RF) based device Habib-4X.
. We prospectively analyzed the data of 280 patients who underwent liver resection for hepatocellular carcinoma at our institution from 2010-2012 with follow up till August 2016. The CUSA was used in the 163 patients whilst Habib-4X in 117 patients. The end points of analysis were oncological outcomes as disease recurrence, disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method, which has been compared with all other existing literature on the survival study. Compared with CUSA the reported incidence of recurrence was significantly lower, in Habib-4X group; p Habib-4X group than CUSA group (50.80 vs 45.87 months, p = 0.03). The median OS was better in Habib-4X group than CUSA group (60.57 vs 57.17 months, p = 0.12) though the lesser difference in OS between the groups might be explained by the use of palliative therapies as TACE, percutaneous RFA, etc. in case of recurrence. RF based device Habib-4X, is safe and effective device for resection of hepatocellular carcinoma, in comparison to CUSA with better oncological outcomes, i.e., significantly lesser tumour recurrence and better DFS. This could be explained on the basis of systemic and local immunomodulatory effect involving induction of kupffer cells and effector CD-8 T cells that help in minimizing postoperative complications and bring more advantageous oncological outcomes.

Coagulation-Adsorption Hybrid Process for the Treatment of Dyes and Pigments Wastewater

Directory of Open Access Journals (Sweden)

Abdul Karim Shah

2013-10-01

Full Text Available The study aimed to improve the effectiveness of dyes and pigments wastewater treatment. Hybrid system of adsorption and coagulation was applied for the reduction of COD, color, turbidity and TSS. Activated carbon adsorbent was prepared from a waste of sugar industry boiler. It was processed through physicochemical treatment with sulfuric acid following grinding, sieving, washing and drying unit operations. Combined wastewater of dyes and pigments manufacturing plant was treated with a hybrid process of coagulation and adsorption. FeCl 3, FeSO 4and Alum coagulants were tested individually and found them less effective. It was revealed that FeCl 3 coagulation, adsorption and hybrid process reduced COD (41, 51 and 54%, Color (67, 70 and 89%, turbidity (69, 71 and 90% and TSS (82, 93 and 97% respectively. Combination of FeCl3 -SBFA (Sugarcane Bagasse Fly Ash proved 90% efficient in removal than coagulation as an individual process. 4g adsorbent dose was optimized for this hybrid process

New radiofrequency device to reduce bleeding after core needle biopsy: Experimental study in a porcine liver model

International Nuclear Information System (INIS)

Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun

2017-01-01

To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments

New radiofrequency device to reduce bleeding after core needle biopsy: Experimental study in a porcine liver model

Energy Technology Data Exchange (ETDEWEB)

Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2017-01-15

To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments.

Comparison of renal artery, soft tissue, and nerve damage after irrigated versus nonirrigated radiofrequency ablation.

Science.gov (United States)

Sakakura, Kenichi; Ladich, Elena; Fuimaono, Kristine; Grunewald, Debby; O'Fallon, Patrick; Spognardi, Anna-Maria; Markham, Peter; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Shen, Kai; Kolodgie, Frank D; Joner, Michael; Virmani, Renu

2015-01-01

The long-term efficacy of radiofrequency ablation of renal autonomic nerves has been proven in nonrandomized studies. However, long-term safety of the renal artery (RA) is of concern. The aim of our study was to determine if cooling during radiofrequency ablation preserved the RA while allowing equivalent nerve damage. A total of 9 swine (18 RAs) were included, and allocated to irrigated radiofrequency (n=6 RAs, temperature setting: 50°C), conventional radiofrequency (n=6 RAs, nonirrigated, temperature setting: 65°C), and high-temperature radiofrequency (n=6 RAs, nonirrigated, temperature setting: 90°C) groups. RAs were harvested at 10 days, serially sectioned from proximal to distal including perirenal tissues and examined after paraffin embedding, and staining with hematoxylin-eosin and Movat pentachrome. RAs and periarterial tissue including nerves were semiquantitatively assessed and scored. A total of 660 histological sections from 18 RAs were histologically examined by light microscopy. Arterial medial injury was significantly less in the irrigated radiofrequency group (depth of medial injury, circumferential involvement, and thinning) than that in the conventional radiofrequency group (Pradiofrequency group (Pradiofrequency group and conventional radiofrequency group (P=0.36), there was a trend toward less nerve damage in the irrigated compared with conventional. Compared to conventional radiofrequency, circumferential medial damage in highest-temperature nonirrigated radiofrequency group was significantly greater (Pradiofrequency ablation, and there is a trend toward less nerve damage. © 2014 American Heart Association, Inc.

Electromagnetic field sources in radiofrequency

International Nuclear Information System (INIS)

Oliveira, C.; Sebastiao, D.; Ladeira, D.; Antunes, M.; Correia, L.M.

2010-01-01

In the scope of the monIT Project, several measurements were made of electromagnetic fields in Portugal. This paper presents an analysis of the sources operating in the radiofrequency range, resulting from 2429 measurements in 466 locations.

Modelling of the Blood Coagulation Cascade in an In Vitro Flow System

DEFF Research Database (Denmark)

Andersen, Nina Marianne; Sørensen, Mads Peter; Efendiev, Messoud A.

2010-01-01

We derive a mathematical model of a part of the blood coagulation cascade set up in a perfusion experiment. Our purpose is to simulate the influence of blood flow and diffusion on the blood coagulation pathway. The resulting model consists of a system of partial differential equations taking...... and flow equations, which guarantee non negative concentrations at all times. The criteria is applied to the model of the blood coagulation cascade....

REMOVAL OF ORGANIC MATTER FROM SURFACE WATER USING COAGULANTS WITH VARIOUS BASICITY

Directory of Open Access Journals (Sweden)

Lidia Dąbrowska

2016-07-01

Full Text Available Humic substances are a natural admixture of surface water and determine the level of organic pollution of water and colour intensity. Application of coagulation process in surface water treatment allows for decrease turbidity and colour of water, as well as organic matter content. In Poland most drinking water treatment plants use aluminium sulphate as a coagulant. Research works on pre-hydrolysed coagulants, e.g. polyaluminium chlorides (general formula Aln(OHmCl3n-m are also carried out. The aim of this study was to evaluate the effectiveness of the coagulation process using polyaluminium chlorides with different basicity, in reducing the level of pollution of surface water with organic substances. Apart from the typical indicators used to evaluate the content of organic compounds, the potential for trihalomethanes formation THM-FP was also determined. The influence of the type of coagulant (low, medium, highly alkaline on the efficiency of organic compound removal, determined as total organic carbon TOC, oxidisability OXI, absorbance UV254, was stated. Under the conditions of the coagulation (pH 7.2-7.4, temperature of 19-21°C, the best results were obtained using highly alkaline polyaluminium chlorides PAX-XL19F, PAX-XL1905 and PAX-XL1910S, decrease in TOC and OXI by 43-46%, slightly worse - 40-41% using low alkaline PAX18. Using the medium alkaline coagulants PAX-XL61 and PAXX-XL69, 30-35% removal of organic matter was obtained. Despite various effects of dissolved organic carbon removal, depending on the used coagulant, THM-FP in purified water did not differ significantly and ranged from 10.0 to 10.9 mgCHCl3 m-3. It was by 37-42% lower than in surface water.

New treatment strategies for disseminated intravascular coagulation based on current understanding of the pathophysiology

NARCIS (Netherlands)

Levi, Marcel; de Jonge, Evert; van der Poll, Tom

2004-01-01

A variety of clinical conditions may cause systemic activation of coagulation, ranging from insignificant laboratory changes to severe disseminated intravascular coagulation (DIC). DIC consists of a widespread, systemic activation of coagulation, resulting in diffuse fibrin deposition in small and

[Coagulation factor VII levels in uremic patients and theirs influence factors].

Science.gov (United States)

Fang, Jun; Xia, Ling-Hui; Wei, Wen-Ning; Song, Shan-Jun

2004-12-01

This study was aimed to investigate coagulation factor VII level in uremic patients with chronic renal failure and to explore theirs influence factors. The plasma levels of coagulation factor VII were detected in 30 uremic patients with chronic renal failure before and after hemodialysis for 1 month, the factor VII activity (FVII:C) was determined by one-stage coagulation method, while activated factor VII (FVIIa) was measured by one-stage coagulation method using recombinant soluble tissue factor, and factor VII antigen was detected by ELISA. The results showed that: (1) The FVIIa, FVII:C and FVIIAg levels in chronic uremic patients before hemodialysis were 4.00 +/- 0.86 microg/L, (148.5 +/- 40.4)% and (99.8 +/- 21.1)% respectively, which were significantly increased, as compared with healthy controls [2.77 +/- 1.02 microg/L, (113.1 +/- 33.0)% and (73.7 +/- 18.3)% respectively, P factor VII was positively correlated with levels of blood uria nitrogen and serum creatinine before hemodialysis but not after hemodialysis. It is concluded that the enhanced levels of coagulation factor VII in chronic uremic patients suggested abnormal activated state, herperactivity and elevated production of factor VII which correlated with renal functional injury. The abnormality of factor VII in uremia may be aggravated by hemodialysis. Coagulation factor (FVII) may be a risk factor for cardiovascular events in uremic patients who especially had been accepted long-term hemodialysis.

Removal of total suspended solid by natural coagulant derived from cassava peel waste

Science.gov (United States)

Mohd-Asharuddin, S.; Othman, N.; Mohd-Zin, N. S.; Tajarudin, H. A.

2018-04-01

The present study was aimed to investigate the performance of starch derived from cassava peel waste as primary coagulant and coagulant aid. Comparable study was also conducted using commercially used aluminium sulfate (alum) as primary coagulant. A series of Jar tests were performed using raw water from Sembrong Barat water treatment plant. It was observed that coagulation test using cassava peel starch (CPS) alone had unappreciable removing ability. However, it was found that combination of alum-CPS successfully achieve up to 90.48% of total suspended solid (TSS) removal under optimized working conditions (pH 9, 7.5mg/L : 100 mg/L of alum : CPS dosage, rapid mixing of 200 rpm for 1 minute; 100 rpm for 2 minutes, slow mixing of 25 rpm for 30 minutes and 30 minutes settling time). This remarks the reduction in alum dosage up to 50% compared to coagulation test using alum alone. Therefore this finding suggesting that CPS can be considered as potential source of sustainable and effective coagulant aid for water treatment especially in developing countries.

Radiofrequency ablation with epinephrine injection: in vivo study in normal pig livers

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyoung Jung; Lee, Dong Hoo; Lim, Joo Won; Ko, Young Tae; Kim, Youn Wha; Choi, Bong Keun [Kyung Hee University Medical Center, Seoul (Korea, Republic of)

2007-07-15

We wanted to evaluate whether epinephrine injection prior to radiofrequency (RF) ablation can increase the extent of thermally mediated coagulation in vivo normal pig liver tissue. Eighteen RF ablation zones were created in six pigs using a 17-gauge internally cooled electrode under ultrasound guidance. Three RF ablation zones were created in each pig under three conditions: RF ablation alone, RF ablation after the injection of 3 mL of normal saline, and RF ablation after the injection of 3 mL of epinephrine (1:10,000 solution). After the RF ablation, we measured the short and long diameters of the white zones in the gross specimens. Three of the RF ablations were technically unsuccessful; therefore, measurement of white zone was finally done in 15 RF ablation zones. The mean short and long diameters of the white zone of the RF ablation after epinephrine injection (17.2 mm {+-} 1.8 and 20.8 mm {+-} 3.7, respectively) were larger than those of RF ablation only (10 mm {+-} 1.2 and 12.2 mm {+-} 1.1, respectively) and RF ablation after normal saline injection (12.8 mm {+-} 1.5 and 15.6 mm {+-} 2.5, respectively) ({rho} < .05). RF ablation with epinephrine injection can increase the diameter of the RF ablation zone in normal pig liver tissue.

Causes and consequences of coagulation activation in sepsis: an evolutionary medicine perspective.

Science.gov (United States)

Fiusa, Maiara Marx Luz; Carvalho-Filho, Marco Antonio; Annichino-Bizzacchi, Joyce M; De Paula, Erich V

2015-05-06

Coagulation and innate immunity have been linked together for at least 450 million years of evolution. Sepsis, one of the world's leading causes of death, is probably the condition in which this evolutionary link is more evident. However, the biological and the clinical relevance of this association have only recently gained the attention of the scientific community. During sepsis, the host response to a pathogen is invariably associated with coagulation activation. For several years, coagulation activation has been solely regarded as a mechanism of tissue damage, a concept that led to several clinical trials of anticoagulant agents for sepsis. More recently, this paradigm has been challenged by the failure of these clinical trials, and by a growing bulk of evidence supporting the concept that coagulation activation is beneficial for pathogen clearance. In this article we discuss recent basic and clinical data that point to a more balanced view of the detrimental and beneficial consequences of coagulation activation in sepsis. Reappraisal of the association between coagulation and immune activation from an evolutionary medicine perspective offers a unique opportunity to gain new insights about the pathogenesis of sepsis, paving the way to more successful approaches in both basic and clinical research in this field.

Pretreatment of wastewater: Optimal coagulant selection using Partial Order Scaling Analysis (POSA)

International Nuclear Information System (INIS)

Tzfati, Eran; Sein, Maya; Rubinov, Angelika; Raveh, Adi; Bick, Amos

2011-01-01

Jar-test is a well-known tool for chemical selection for physical-chemical wastewater treatment. Jar test results show the treatment efficiency in terms of suspended matter and organic matter removal. However, in spite of having all these results, coagulant selection is not an easy task because one coagulant can remove efficiently the suspended solids but at the same time increase the conductivity. This makes the final selection of coagulants very dependent on the relative importance assigned to each measured parameter. In this paper, the use of Partial Order Scaling Analysis (POSA) and multi-criteria decision analysis is proposed to help the selection of the coagulant and its concentration in a sequencing batch reactor (SBR). Therefore, starting from the parameters fixed by the jar-test results, these techniques will allow to weight these parameters, according to the judgments of wastewater experts, and to establish priorities among coagulants. An evaluation of two commonly used coagulation/flocculation aids (Alum and Ferric Chloride) was conducted and based on jar tests and POSA model, Ferric Chloride (100 ppm) was the best choice. The results obtained show that POSA and multi-criteria techniques are useful tools to select the optimal chemicals for the physical-technical treatment.

Multipurpose HTS Coagulation Analysis: Assay Development and Assessment of Coagulopathic Snake Venoms

Directory of Open Access Journals (Sweden)

Kristina B. M. Still

2017-11-01

Full Text Available Coagulation assays currently employed are often low throughput, require specialized equipment and/or require large blood/plasma samples. This study describes the development, optimization and early application of a generic low-volume and high-throughput screening (HTS assay for coagulation activity. The assay is a time-course spectrophotometric measurement which kinetically measures the clotting profile of bovine or human plasma incubated with Ca2+ and a test compound. The HTS assay can be a valuable new tool for coagulation diagnostics in hospitals, for research in coagulation disorders, for drug discovery and for venom research. A major effect following envenomation by many venomous snakes is perturbation of blood coagulation caused by haemotoxic compounds present in the venom. These compounds, such as anticoagulants, are potential leads in drug discovery for cardiovascular diseases. The assay was implemented in an integrated analytical approach consisting of reversed-phase liquid chromatography (LC for separation of crude venom components in combination with parallel post-column coagulation screening and mass spectrometry (MS. The approach was applied for the rapid assessment and identification of profiles of haemotoxic compounds in snake venoms. Procoagulant and anticoagulant activities were correlated with accurate masses from the parallel MS measurements, facilitating the detection of peptides showing strong anticoagulant activity.

Arsenic removal by coagulation using ferric chloride and chitosan from water

Directory of Open Access Journals (Sweden)

Farid Hesami

2013-01-01

Conclusions: Chitosan as natural coagulant aid improved arsenic removal efficiency by coagulation process using FeCl 3 . This method can be used for regions with drinking water contaminated with initial arsenic concentration less than 1 000 μg/l.

Evaluation of Moringa oleifera seed as coagulation aid for treatment ...

African Journals Online (AJOL)

Laboratory tests were carried out to evaluate the potentials of Moringa oleifera seed powder as a coagulation aid for removal of suspended particles in fish culture effluent. The standard jar test was used to investigate the dosage and mixing intensity required to optimize the use of the coagulant in removing of suspended ...

Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety

Science.gov (United States)

Alvarez-Sánchez, María-Victoria; Napoléon, Bertrand

2016-01-01

Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with self-expanding metal stents (SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency (RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation (RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reports have also

Coagulation of sheep intestinal and prefemoral lymph.

Science.gov (United States)

Hanley, C A; Johnston, M G; Nelson, W

1988-06-01

We have determined the most suitable method for the automated analysis of the clotting parameters in sheep intestinal and prefemoral lymph as defined by the Activated Partial Thromboplastin Times (APTT; measure of intrinsic coagulation pathway) and the Prothrombin Times (PT; measure of extrinsic coagulation pathway). As opposed to optical density systems, the use of a Fibro-System Fibrometer was found to provide the most consistent assessment of coagulation with the endpoint being the time to fibrin strand formation. We measured APTT in sheep intestinal and prefemoral lymph of 59.78 +/- 7.69 seconds and 51.03 +/- 10.49 seconds respectively. These values were more prolonged than those obtained from sheep blood plasma but only in the case of intestinal lymph were the differences significant (p less than 0.025). Human blood APTT values were significantly less than both sheep blood (p less than 0.05) and sheep intestinal (p less than 0.001) and prefemoral lymph (p less than 0.01). PT values were found to be 21.56 +/- 1.14 seconds in intestinal and 22.00 +/- 1.88 seconds in prefemoral lymph. These values were also significantly greater than those obtained from sheep blood (both p less than 0.001). Human blood PTs were significantly less than both sheep blood (p less than 0.001) and intestinal and prefemoral lymph (both p less than 0.001). Measurement of APTT and PT values in intestinal lymph and PT determinations in prefemoral lymph were not affected by storage in the refrigerator or freezer. There was some indication that APTT values in prefemoral samples were susceptible to storage artifacts; however, the differences in coagulation times were not significant.

[Catheter ablation in patients with refractory cardiac arrhythmias with radiofrequency techniques].

Science.gov (United States)

de Paola, A A; Balbão, C E; Silva Netto, O; Mendonça, A; Villacorta, H; Vattimo, A C; Souza, I A; Guiguer Júnior, N; Portugal, O P; Martinez Filho, E E

1993-02-01

evaluate the efficacy of radiofrequency catheter ablation in patients with refractory cardiac arrhythmias. twenty patients with refractory cardiac arrhythmias were undertaken to electrophysiologic studies for diagnosis and radiofrequency catheter ablation of their reentrant arrhythmias. Ten patients were men and 10 women with ages varying from 13 to 76 years (mean = 42.4 years). Nineteen patients had supraventricular tachyarrhythmias: One patient had atrial tachycardia and 1 atrial fibrillation with rapid ventricular rate, 5 patients had reentrant nodal tachycardia, 12 patients had reentrant atrioventricular tachycardia and 1 patient had right ventricular outflow tract tachycardia. the mean time of the procedure was 4.1 hours. The radiofrequency current energy applied was 40-50 V for 30-40 seconds. Ablation was successful in 18/20 (90%) patients; in 15/18 (83%) of successfully treated patients the same study was done for diagnosis and radiofrequency ablation. One patient had femoral arterial occlusion and was treated with no significant sequelae. During a mean follow-up of 4 months no preexcitation or reentrant tachycardia occurred. the results of our experience with radiofrequency catheter ablation of cardiac arrhythmias suggest that this technique can benefit an important number of patients with cardiac arrhythmias.

Radiofrequency ablation of hepatic metastasis: Results of treatment in forty patients

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Rath G

2008-01-01

Full Text Available Aim: To evaluate the local control of hepatic metastasis with radiofrequency ablation treatment. Materials and Methods: We did a retrospective analysis in 40 patients treated with radiofrequency ablation for hepatic metastasis. The tumors ablated included up to two metastatic liver lesions, with primaries in breast, gastrointestinal tract, cervix, etc. Radiofrequency ablation was performed under general anesthesia in all cases, using ultrasound guidance. Radionics Cool-Tip RF System was used to deliver the treatment. Results: The median age of patients treated was 49 years. There were 13 female and 27 male patients. The median tumor size ablated was 1.5 cm (0.75-4.0 cm. A total of 52 radiofrequency ablation cycles were delivered. Successful ablation was achieved in all patients with hepatic metastasis less than 3 cm in size. Pain was the most common complication seen (75%. One patients developed skin burns. At 2-year follow-up 7.5% of patients had locally recurrent disease. Conclusions: Radiofrequency ablation is a minimally invasive treatment modality. It can be useful in a select group of patients with solitary liver metastasis of less than 3 cm size.

21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation, including...

Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

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L. D. Sánchez

2012-12-01

Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

Performance optimization of coagulant/flocculant in the treatment of wastewater from a beverage industry.

Science.gov (United States)

Amuda, O S; Amoo, I A; Ajayi, O O

2006-02-28

This study investigated the effect of coagulation/flocculation treatment process on wastewater of Fumman Beverage Industry, Ibadan, Nigeria. The study also compared different dosages of coagulant, polyelectrolyte (non-ionic polyacrylamide) and different pH values of the coagulation processes. The effect of different dosages of polyelectrolyte in combination with coagulant was also studied. The results reveal that low pH values (3-8), enhance removal efficiency of the contaminants. Percentage removal of 78, 74 and 75 of COD, TSS and TP, respectively, were achieved by the addition of 500 mg/L Fe2(SO4)3.3H2O and 93, 94 and 96% removal of COD, TSS and TP, respectively, were achieved with the addition of 25 mg/L polyelectrolyte to the coagulation process. The volume of sludge produced, when coagulant was used solely, was higher compared to the use of polyelectrolyte combined with Fe2(SO4)3.3H2O. This may be as a result of non-ionic nature of the polyelectrolyte; hence, it does not chemically react with solids of the wastewater. Coagulation/flocculation may be useful as a pre-treatment process for beverage industrial wastewater prior to biological treatment.

Influence of floc size and structure on membrane fouling in coagulation-ultrafiltration hybrid process-The role of Al{sub 13} species

Energy Technology Data Exchange (ETDEWEB)

Xu, Weiying [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan 250100, Shandong (China); Gao, Baoyu, E-mail: baoyugao_sdu@yahoo.com.cn [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan 250100, Shandong (China); Mao, Ranran; Yue, Qinyan [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan 250100, Shandong (China)

2011-10-15

Highlights: {yields} The optimum dose of Al{sub 13} for improving the membrane permeability was 5 mg/L and for PACl was 7 mg/L. {yields} Effluent coagulated by Al{sub 13} species presented lower proportion of R{sub a} in the total resistance due to the high strength of Al{sub 13}-HA flocs. {yields} The high D{sub f} of flocs formed by Al{sub 13} was not favorable for the reduction of cake layer resistance. - Abstract: Coagulation application prior to ultrafiltration process was carried out to increase humic acid (HA) removal and membrane permeability. The [Al{sub 13}O{sub 4}(OH){sub 24}(H{sub 2}O){sub 12}]{sup 7+} polycation (Al{sub 13} species) was used in the coagulant process and polyaluminum chloride (PACl) was also used for comparison. Characteristics of aggregates pre-coagulated by Al{sub 13} species and PACl were investigated using a laser diffraction particle sizing device. Additionally, membrane fouling was investigated under different coagulation conditions. The various resistances caused by Al{sub 13} and PACl treatment effluents were determined using the membrane fouling index equation. The results indicated that at dose of 1 and 3 mg/L, Al{sub 13} produced larger flocs than PACl; while when dosage further increased, the PACl-HA flocs were much larger. The flocs formed by Al{sub 13} were strong and compact, and those formed by PACl were weak and loosely structured with the exception of the flocs generated at 1 mg/L. The investigation of membrane fouling demonstrated that Al{sub 13} contributed to the best effluent permeating at 5 mg/L and the corresponding dose for PACl was 7 mg/L. The adsorption resistance of effluent pre-treated by Al{sub 13} accounted for a smaller percentage of the total resistances compared with that by PACl.

Inhibitory Effect of Triterpenoids from Panax ginseng on Coagulation Factor X

Directory of Open Access Journals (Sweden)

Lingxin Xiong

2017-04-01

Full Text Available Enzymes involved in the coagulation process have received great attention as potential targets for the development of oral anti-coagulants. Among these enzymes, coagulation factor Xa (FXa has remained the center of attention in the last decade. In this study, 16 ginsenosides and two sapogenins were isolated, identified and quantified. To determine the inhibitory potential on FXa, the chromogenic substrates method was used. The assay suggested that compounds 5, 13 and 18 were mainly responsible for the anti-coagulant effect. Furthermore, these three compounds also possessed high thrombin selectivity in the thrombin inhibition assay. Furthermore, Glide XP from Schrödinger was employed for molecular docking to clarify the interaction between the bioactive compounds and FXa. Therefore, the chemical and biological results indicate that compounds 5 (ginsenoside Rg2, 13 (ginsenoside Rg3 and 18 (protopanaxtriol, PPT are potential natural inhibitors against FXa.

Interpretation of coagulation test results using a web-based reporting system.

Science.gov (United States)

Quesada, Andres E; Jabcuga, Christine E; Nguyen, Alex; Wahed, Amer; Nedelcu, Elena; Nguyen, Andy N D

2014-01-01

Web-based synoptic reporting has been successfully integrated into diverse fields of pathology, improving efficiency and reducing typographic errors. Coagulation is a challenging field for practicing pathologists and pathologists-in-training alike. To develop a Web-based program that can expedite the generation of a individualized interpretive report for a variety of coagulation tests. We developed a Web-based synoptic reporting system composed of 119 coagulation report templates and 38 thromboelastography (TEG) report templates covering a wide range of findings. Our institution implemented this reporting system in July 2011; it is currently used by pathology residents and attending pathologists. Feedback from the users of these reports have been overwhelmingly positive. Surveys note the time saved and reduced errors. Our easily accessible, user-friendly, Web-based synoptic reporting system for coagulation is a valuable asset to our laboratory services. Copyright© by the American Society for Clinical Pathology (ASCP).

A Newly Developed Perfused Umbrella Electrode for Radiofrequency Ablation: An Ex Vivo Evaluation Study in Bovine Liver

International Nuclear Information System (INIS)

Bruners, Philipp; Pfeffer, Jochen; Kazim, Rana M.; Guenther, Rolf W.; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2007-01-01

The purpose of this study was to evaluate the effectiveness of a newly developed perfused monopolar radiofrequency (RF) probe with an umbrella-shaped array. A perfused umbrella-shaped monopolar RF probe based on a LeVeen electrode (Boston Scientific Corp., Natick, MA, USA) with a 3-cm array diameter was developed. Five different configurations of this electrode were tested: (a) perfusion channel/endhole, (b) perfusion channel/endhole + sideholes, (c) 1 cm insulation removed at the tip, (d) 1 cm insulation removed at the tip + perfusion channel/endhole, and (e) 1 cm insulation removed at the tip + perfusion channel/endhole + sideholes. An unmodified LeVeen electrode served as a reference standard. RF ablations were performed in freshly excised bovine liver using a commercial monopolar RF system with a 200-W generator (RF 3000; Boston Scientific Corp.). Each electrode was tested 10 times applying the vendor's recommended ablation protocol combined with the preinjection of 2 ml 0.9% saline. Volumes and shapes of the lesions were compared. Lesions generated with the original LeVeen electrode showed a mean volume of 12.74 ± 0.52 cm 3 . Removing parts of the insulation led to larger coagulation volumes (22.65 ± 2.12 cm 3 ). Depending on the configuration, saline preinjection resulted in a further increase in coagulation volume (25.22 ± 3.37 to 31.28 ± 2.32 cm 3 ). Besides lesion volume, the shape of the ablation zone was influenced by the configuration of the electrode used. We conclude that saline preinjection in combination with increasing the active tip length of the umbrella-shaped LeVeen RF probe allows the reliable ablation of larger volumes in comparison to the originally configured electrode

Ultrasound-guided percutaneous treatment of hepatocellular carcinoma by radiofrequency hyperthermia with a 'cooled-tip needle'. A preliminary clinical experience.

Science.gov (United States)

Francica, G; Marone, G

1999-05-01

Radiofrequency hyperthermia using the newly-developed 'cooled-tip' needle has recently been proposed as a therapeutic modality for hepatocellular carcinoma (HCC). Herein we report our preliminary results on feasibility and effectiveness of the thermal ablation of mono- or pauci-focal hepatocellular carcinoma with the cooled-tip needle. We treated 15 cirrhotic patients (mean age 68.8 years; 12 males; 14 HCV-positive; 13 in Child's Class A and 2 in Class B) with 20 hepatocellular carcinoma nodules (mean diameter 28.1 mm; range 10-43 mm; nine lesions with diameter greater than 3 cm). None of the patients had portal thrombosis and/or extrahepatic spread. We used a radiofrequency generator (100 W of power) connected to a 18 g perfusion electrode needle with an exposed tip of 2-3 cm. The circuit was closed through a dispersive electrode positioned under the patient's thighs. A peristaltic pump infused a chilled (2-5 degrees C) saline solution to guarantee the continuous cooling of the needle tip. The needle was placed into target lesions under US guidance. The interventional procedure was carried out in general anesthesia without intubation. Dynamic helical CT was carried out 15-20 days after thermal ablation to assess therapeutic efficacy. In all, 38 areas of coagulation necrosis (at 1000-1200 mA for 10-15 min) were generated in 24 sessions in the 20 hepatocellular carcinoma nodules (mean 1.9 lesions per nodule and 1.2 sessions per nodule). Complete necrosis as assessed at dynamic CT (lack of enhancement during the arteriographic phase) was achieved in 75% of cases in a single session; after a second RF session success rate was 90% (18 out of 20 nodules). A self-limited pleurisy along with a 5-fold increase in transaminases occurred in one patient; a 3-fold elevation of transaminases was encountered in three other patients. During the follow-up (median 15 months) five patients had recurrent hepatocellular carcinoma with a 1-year disease free interval of 64%. Of the

Photoacoustic discrimination of viable and thermally coagulated blood using a two-wavelength method for burn injury monitoring

International Nuclear Information System (INIS)

Talbert, Robert J; Holan, Scott H; Viator, John A

2007-01-01

Discriminating viable from thermally coagulated blood in a burn wound can be used to profile burn depth, thus aiding the removal of necrotic tissue. In this study, we used a two-wavelength photoacoustic imaging method to discriminate coagulated and non-coagulated blood in a dermal burn phantom. Differences in the optical absorption spectra of coagulated and non-coagulated blood produce different values of the ratio of peak photoacoustic amplitude at 543 and 633 nm. The absorption values obtained from spectroscopic measurements indicate that the ratio of photoacoustic pressure for 543 and 633 nm for non-coagulated blood was 15.7:1 and 1.6:1 for coagulated blood. Using planar blood layers, we found the photoacoustic ratios to be 13.5:1 and 1.6:1, respectively. Using the differences in the ratios of coagulated and non-coagulated blood, we propose a scheme using statistical classification analysis to identify the different blood samples. Based upon these distinctly different ratios, we identified the planar blood samples with an error rate of 0%. Using a burn phantom with cylindrical vessels containing coagulated and non-coagulated blood, we achieved an error rate of 11.4%. These results have shown that photoacoustic imaging could prove to be a valuable tool in the diagnosis of burns

The use of cold coagulation for the treatment of cervical intraepithelial neoplasia

LENUS (Irish Health Repository)

Wyse, A

2017-05-01

In 2015, Cold Coagulation was introduced as a treatment for cervical intraepithelial neoplasia (CIN) at our colposcopy clinic. We reviewed the 6-month follow up data of the first 200 women who underwent Cold Coagulation using cytology and HPV status as tests of cure (TOC). A random sample of 200 patients treated by Large Loop Excision of the Transformation Zone (LLETZ) during the same period was used to compare treatment outcome. Six months following treatment,173 (86.5%) of the women treated by CC and 167 (83.5%) treated by LLETZ had negative cytology. (x2= P>0.05). 148 (74%) treated by Cold Coagulation and 166 (83%) treated by LLETZ were HPV negative (x2= P<0.05). One hundred and thirty-nine (70%) women treated by Cold Coagulation and 152 (76%) treated with LLETZ had normal cytology and were HPV negative. This audit of our initial experience supports the observation that Cold Coagulation is as effective as LLETZ in the management of CIN when cervical cytology is used as a test of cure.

Comparison of the level of residual coagulant activity in different cheese varieties.

Science.gov (United States)

Bansal, Nidhi; Fox, Patrick F; McSweeney, Paul L H

2009-08-01

The coagulant retained in cheese curd is a major contributor to proteolysis during ripening. The objective of this study was to quantify residual coagulant in 9 cheese varieties by measuring its activity on a synthetic heptapeptide (Pro-Thr-Glu-Phe-[NO2-Phe]-Arg-Leu) assayed using reversed-phase HPLC. The level of residual coagulant activity was highest in Camembert cheese, probably due to its low pH at whey drainage and the high moisture content of the cheese, followed in order by Feta=Port du Salut=Cheddar>Gouda>Emmental=Parmigiano Reggiano=low-moisture part-skim Mozzarella=Mozzarella di Bufala Campana. The high cooking temperature (50-54 degrees C) used during the manufacture of Emmental and Parmigiano Reggiano cheeses and the cooking and stretching step in hot water during the manufacture of Mozzarella cheese may be the reasons for the lowest residual coagulant activity in these cheeses. The level of residual coagulant activity was higher in Feta cheese made from milk concentrated by ultrafiltration than in conventional Feta.

Radiofrequency facial rejuvenation: evidence-based effect.

Science.gov (United States)

el-Domyati, Moetaz; el-Ammawi, Tarek S; Medhat, Walid; Moawad, Osama; Brennan, Donna; Mahoney, My G; Uitto, Jouni

2011-03-01

Multiple therapies involving ablative and nonablative techniques have been developed for rejuvenation of photodamaged skin. Monopolar radiofrequency (RF) is emerging as a gentler, nonablative skin-tightening device that delivers uniform heat to the dermis at a controlled depth. We evaluated the clinical effects and objectively quantified the histologic changes of the nonablative RF device in the treatment of photoaging. Six individuals of Fitzpatrick skin type III to IV and Glogau class I to II wrinkles were subjected to 3 months of treatment (6 sessions at 2-week intervals). Standard photographs and skin biopsy specimens were obtained at baseline, and at 3 and 6 months after the start of treatment. We performed quantitative evaluation of total elastin, collagen types I and III, and newly synthesized collagen using computerized histometric and immunohistochemical techniques. Blinded photographs were independently scored for wrinkle improvement. RF produced noticeable clinical results, with high satisfaction and corresponding facial skin improvement. Compared with the baseline, there was a statistically significant increase in the mean of collagen types I and III, and newly synthesized collagen, while the mean of total elastin was significantly decreased, at the end of treatment and 3 months posttreatment. A limitation of this study is the small number of patients, yet the results show a significant improvement. Although the results may not be as impressive as those obtained by ablative treatments, RF is a promising treatment option for photoaging with fewer side effects and downtime. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

12-month efficacy of a single radiofrequency ablation on autonomously functioning thyroid nodules.

Science.gov (United States)

Bernardi, Stella; Stacul, Fulvio; Michelli, Andrea; Giudici, Fabiola; Zuolo, Giulia; de Manzini, Nicolò; Dobrinja, Chiara; Zanconati, Fabrizio; Fabris, Bruno

2017-09-01

Radiofrequency ablation has been advocated as an alternative to radioiodine and/or surgery for the treatment of autonomously functioning benign thyroid nodules. However, only a few studies have measured radiofrequency ablation efficacy on autonomously functioning benign thyroid nodules. The aim of this work was to evaluate the 12-month efficacy of a single session of radiofrequency ablation (performed with the moving shot technique) on solitary autonomously functioning benign thyroid nodules. Thirty patients with a single, benign autonomously functioning benign thyroid nodules, who were either unwilling or ineligible to undergo surgery and radioiodine, were treated with radiofrequency ablation between April 2012 and May 2015. All the patients underwent a single radiofrequency ablation, performed with the 18-gauge needle and the moving shot technique. Clinical, laboratory, and ultrasound evaluations were scheduled at baseline, and after 1, 3, 6, and 12 months from the procedure. A single radiofrequency ablation reduced thyroid nodule volume by 51, 63, 69, and 75 % after 1, 3, 6, and 12 months, respectively. This was associated with a significant improvement of local cervical discomfort and cosmetic score. As for thyroid function, 33 % of the patients went into remission after 3 months, 43 % after 6 months, and 50 % after 12 months from the procedure. This study demonstrates that a single radiofrequency ablation allowed us to withdraw anti-thyroid medication in 50 % of the patients, who remained euthyroid afterwards. This study shows that a single radiofrequency ablation was effective in 50 % of patients with autonomously functioning benign thyroid nodules. Patients responded gradually to the treatment. It is possible that longer follow-up studies might show greater response rates.

Characteristics of BPA removal from water by PACl-Al13 in coagulation process.

Science.gov (United States)

Xiaoying, Ma; Guangming, Zeng; Chang, Zhang; Zisong, Wang; Jian, Yu; Jianbing, Li; Guohe, Huang; Hongliang, Liu

2009-09-15

This paper discussed the coagulation characteristics of BPA with polyaluminum chloride (PACl-Al(13)) as coagulant, examined the impact of coagulation pH, PACl-Al(13) dosage, TOC (total organic carbon) and turbidity on BPA removal, and analyzed the possible dominant mechanisms in water coagulation process. Formation and performance of flocs during coagulation processes were monitored using photometric dispersion analyzer (PDA). When the concentration of humic acid matters and turbidity was low in the solution, the experimental results showed that the removal of BPA experienced increase and subsequently decrease with the PACl-Al(13) dosage increasing. The optimal PACl-Al(13) dosage was found at BPA/PACl-Al(13)=1:2.6(M/M) under our experiment conditions. Results show that the maximum BPA removal efficiency occurred at pH 9.0 due to the adsorption by Al(13) aggregates onto BPA rather than charge neutralization mechanism by polynuclear aluminous salts in the solution. The humic acid matters and kaolin in the solution have significant effect on BPA removal with PACl-Al(13) in the coagulation. The BPA removal will be weakened at high humic matters. The removal rate of BPA increased and subsequently decreased with the turbidity increasing.

Effects of storage conditions of Moringa oleifera seeds on its performance in coagulation.

Science.gov (United States)

Katayon, S; Noor, M J Megat Mohd; Asma, M; Ghani, L A Abdul; Thamer, A M; Azni, I; Ahmad, J; Khor, B C; Suleyman, A M

2006-09-01

Moringa oleifera is a plant whose seeds have coagulation properties for treating water and wastewater. In this study the coagulation efficiency of Moringa oleifera kept in different storage conditions were studied. The Moringa oleifera seeds were stored at different conditions and durations; open container and closed container at room temperature (28 degrees C) and refrigerator (3 degrees C) for durations of 1, 3 and 5 months. Comparison between turbidity removal efficiency of Moringa oleifera kept in refrigerator and room temperature revealed that there was no significant difference between them. The Moringa oleifera kept in refrigerator and room temperature for one month showed higher turbidity removal efficiency, compared to those kept for 3 and 5 months, at both containers. The coagulation efficiency of Moringa oleifera was found to be dependent on initial turbidity of water samples. Highest turbidity removals were obtained for water with very high initial turbidity. In summary coagulation efficiency of Moringa oleifera was found independent of storage temperature and container, however coagulation efficiency of Moringa oleifera decreased as storage duration increased. In addition, Moringa oleifera can be used as a potential coagulant especially for very high turbidity water.

Application of Moringa Oleifera Seed Powder for Iron (III) Coagulation on Local Water Resources

OpenAIRE

Prasetyaningtyas, Fadillah Utami; Rumhayati, Barlah; Masruri, Masruri

2013-01-01

This research aims to know the effect of the use of powder moringa seed to coagulant mass and coagulation process, and its effectiveness to increase the quality of pure water. This research uses factorial research design and statistic test MANOVA. To analyse water quality, the researcher uses Fe parameter.  A graphic of coagulant mass and time for each parameter is used to analyse the data. Based on the research result, the uses of moringa seed as coagulant in each 300 mL mineral water gives ...

Diffusion mediated coagulation and fragmentation based study of domain formation in lipid bilayer membrane

Energy Technology Data Exchange (ETDEWEB)

Rao, Laxminarsimha V., E-mail: laxman@iitk.ac.in [Mechanics and Applied Mathematics Group, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Roy, Subhradeep [Department of Biomedical Engineering and Mechanics (MC 0219), Virginia Tech, 495 Old Turner Street, Blacksburg, VA 24061 (United States); Das, Sovan Lal [Mechanics and Applied Mathematics Group, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

2017-01-15

We estimate the equilibrium size distribution of cholesterol rich micro-domains on a lipid bilayer by solving Smoluchowski equation for coagulation and fragmentation. Towards this aim, we first derive the coagulation kernels based on the diffusion behaviour of domains moving in a two dimensional membrane sheet, as this represents the reality better. We incorporate three different diffusion scenarios of domain diffusion into our coagulation kernel. Subsequently, we investigate the influence of the parameters in our model on the coagulation and fragmentation behaviour. The observed behaviours of the coagulation and fragmentation kernels are also manifested in the equilibrium domain size distribution and its first moment. Finally, considering the liquid domains diffusing in a supported lipid bilayer, we fit the equilibrium domain size distribution to a benchmark solution.

Endoscopic ultrasound guided radiofrequency ablation, for pancreatic cystic neoplasms and neuroendocrine tumors

Science.gov (United States)

Pai, Madhava; Habib, Nagy; Senturk, Hakan; Lakhtakia, Sundeep; Reddy, Nageshwar; Cicinnati, Vito R; Kaba, Iyad; Beckebaum, Susanne; Drymousis, Panagiotis; Kahaleh, Michel; Brugge, William

2015-01-01

AIM: To outline the feasibility, safety, adverse events and early results of endoscopic ultrasound (EUS)-radiofrequency ablation (RFA) in pancreatic neoplasms using a novel probe. METHODS: This is a multi-center, pilot safety feasibility study. The intervention described was radiofrequency ablation (RF) which was applied with an innovative monopolar RF probe (1.2 mm Habib EUS-RFA catheter) placed through a 19 or 22 gauge fine needle aspiration (FNA) needle once FNA was performed in patients with a tumor in the head of the pancreas. The Habib™ EUS-RFA is a 1 Fr wire (0.33 mm, 0.013”) with a working length of 190 cm, which can be inserted through the biopsy channel of an echoendoscope. RF power is applied to the electrode at the end of the wire to coagulate tissue in the liver and pancreas. RESULTS: Eight patients [median age of 65 (range 27-82) years; 7 female and 1 male] were recruited in a prospective multicenter trial. Six had a pancreatic cystic neoplasm (four a mucinous cyst, one had intraductal papillary mucinous neoplasm and one a microcystic adenoma) and two had a neuroendocrine tumors (NET) in the head of pancreas. The mean size of the cystic neoplasm and NET were 36.5 mm (SD ± 17.9 mm) and 27.5 mm (SD ± 17.7 mm) respectively. The EUS-RFA was successfully completed in all cases. Among the 6 patients with a cystic neoplasm, post procedure imaging in 3-6 mo showed complete resolution of the cysts in 2 cases, whilst in three more there was a 48.4% reduction [mean pre RF 38.8 mm (SD ± 21.7 mm) vs mean post RF 20 mm (SD ± 17.1 mm)] in size. In regards to the NET patients, there was a change in vascularity and central necrosis after EUS-RFA. No major complications were observed within 48 h of the procedure. Two patients had mild abdominal pain that resolved within 3 d. CONCLUSION: EUS-RFA of pancreatic neoplasms with a novel monopolar RF probe was well tolerated in all cases. Our preliminary data suggest that the procedure is straightforward and safe. The

Blood coagulation and fibrinolysis of the whole-body irradiated rabbits

International Nuclear Information System (INIS)

Hishikawa-Itoh, Youko; Ayakawa, Yoshio; Miyata, Nobuki

1984-01-01

To study the effects of irradiation on blood coagulation and fibrinolysis, rabbits were irradiated with 60 Co γ-rays (whole-body: 0, 100, 400, 800, 1200 rads). Clotting time, activity of plasmin and plasminogen, and fibrinogen contents of irradiated rabbit plasma were measured at 4 days before, immediately after, and at 1, 3, 7, 10, and 14 days after irradiation. Both clotting times obtained by addition of (kaolin+phospholipid) which expressed effects on the total intrinsic coagulation system, and by addition of (Ca 2+ ) which expressed effects on the total extrinsic coagulation system, were prolonged with small dose irradiation (100 rads) immediately and 3 days after irradiation. However, with high dose irradiation (400-1200 rads), these clotting times were prolonged 1 day after irradiation. The times of manifestation of irradiation effects on clotting time were different in small and high dose irradiation. Plasmin activity was decreased immediately, 1 day after and recovered 3 days after irradiation. Plasminogen activity was markedly increased in 800 and 1200 rads irradiated groups from 3 days after irradiation. Conversion of plasminogen into plasmin was impaired by irradiation. Fibrinogen contents increased rapidly in all irradiated rabbits except for 100 rads from 1 day after irradiation. These results revealed decreased coagulation and fibrinolysis activities in rabbit blood, irradiation injury of both coagulation and fibrinolysis activation systems, and accumulation of the precursors of fibrin and plasmin (i.e., fibrinogen and plasminogen). (author)

WORKSHOP: Radiofrequency superconductivity

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-10-15

The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators.

WORKSHOP: Radiofrequency superconductivity

International Nuclear Information System (INIS)

Anon.

1984-01-01

The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators

Nanoparticles and the blood coagulation system. Part I: benefits of nanotechnology.

Science.gov (United States)

Ilinskaya, Anna N; Dobrovolskaia, Marina A

2013-05-01

Nanotechnology is proven to provide certain benefits in drug delivery by improving solubility, increasing uptake to target sites and changing pharmacokinetics profiles of traditional drugs. Since properties of many materials change tremendously at the nanoscale levels, nanotechnology is also being explored in various industrial applications. As such, nanoparticles are rapidly entering various areas of industry, biology and medicine. The benefits of using nanotechnology for industrial and biomedical applications are often tempered by concerns about the safety of these new materials. One such area of concern includes their effect on the immune system. While nanoparticle interactions with various constituents of the immune system have been reviewed before, little attention was given to nanoparticle effects on the blood coagulation system. Nanoparticle interface with the blood coagulation system may lead to either benefits to the host or adverse reactions. This article reviews recent advances in our understanding of nanoparticle interactions with plasma coagulation factors, platelets, endothelial cells and leukocytes. Part I is focused on desirable interactions between nanoparticles and the coagulation system, and discusses benefits of using nanotechnology to intervene in coagulation disorders. Undesirable interactions posing safety concerns are covered in part II, which will be published in the June issue of Nanomedicine.

Effect of fibrinogen on blood coagulation detected by optical coherence tomography

International Nuclear Information System (INIS)

Xu, Xiangqun; Teng, Xiangshuai

2015-01-01

Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d 1/e ) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d 1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0–8 g L −1 ); and 2) native plasma with commercial Fbg added (0–8 g L −1 ). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels. (paper)

Chemical coagulants and Moringa oleifera seed extract for treating concrete wastewater

Directory of Open Access Journals (Sweden)

Heber Martins de Paula

2016-01-01

Full Text Available Wastewater from concrete plants has a high pH and a high concentration of suspended solids, necessitating treatment before reuse or discharge into the environment. The objective of this study is to evaluate the efficiency of two chemical coagulants, aluminum sulfate (Al2(SO43 and iron chloride (FeCl3, and a natural coagulant, Moringa oleifera (MO, all in their soluble forms, in the treatment of wastewater from concrete plants. To this end, the efficiencies of the three coagulants, in combinations with different proportions, were tested. The quality parameters of the wastewater obtained after the treatments were compared to the limit values for non-potable water. The use of coagulants in their soluble form potentiates their effect, especially when preparing the MO extract, i.e., greater amounts of the protein responsible for the coagulation is extracted. A mixture with MO and Al2(SO43 in a 20:80 proportion showed the best results, with 97.5% of the turbidity removed at 60 min. of sedimentation, allowing the treated water to be used for washing vehicles and flushing toilets. The FeCl3 treatment produced a high concentration of chlorides, which could cause corrosion problems, and is therefore not recommended for concrete wastewater treatment.

Aqueous arsenite removal by simultaneous ultraviolet photocatalytic oxidation-coagulation of titanium sulfate

Energy Technology Data Exchange (ETDEWEB)

Wang, Yuxia [Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, School of Environmental & Municipal Engineering, Xi’an University of Architecture and Technology (China); Duan, Jinming, E-mail: jinmingduan@xauat.edu.cn [Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, School of Environmental & Municipal Engineering, Xi’an University of Architecture and Technology (China); Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Mawson Lakes Campus, South Australia (Australia); Li, Wei [Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, School of Environmental & Municipal Engineering, Xi’an University of Architecture and Technology (China); Beecham, Simon; Mulcahy, Dennis [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Mawson Lakes Campus, South Australia (Australia)

2016-02-13

Highlights: • A simultaneous UV catalysed oxidation–coagulation for As(III) removal is proposed. • As(III) was effectively oxidised to As(V) by the UV catalysed coagulation. • >99% removal for As(III) in pH 4–6 at low doses of Ti(SO{sub 4}){sub 2} was achieved. • Concurrent UV radiation in massive small crystal formation facilitate the effects. • Reaction mechanisms involve both hydroxyl radicals and superoxide radicals. - Abstract: This study explored the efficacy and efficiency of a simultaneous UV-catalyzed oxidation–coagulation process of titanium sulfate (UV/Ti(SO{sub 4}){sub 2}) for efficient removal of As(III) from water. It revealed that, As(III) could be oxidized to As(V) during the UV catalyzed coagulation of Ti(SO{sub 4}){sub 2} with highly efficient As(III) removal in the pH range 4–6{sub .} The UV catalyzed oxidation–coagulation showed surprisingly effective oxidation of As(III) to As(V) within a short time. XPS indicated that 84.7% of arsenic on the coagulated precipitate was in the oxidized form of As(V) after the UV/Ti(SO{sub 4}){sub 2} treatment of As(III) aqueous solutions at pH 5. Arsenic remaining in solution at high pH was in the oxidized form As(V). Removal efficiencies of As(III) were investigated as a function of pH, Ti(SO{sub 4}){sub 2} dosage, initial As(III) concentration and irradiation energy. As(III) could almost completely be removed (>99%) by the photocatalytic oxidation–coagulation process with a moderate dose of Ti(SO{sub 4}){sub 2} in the pH range 4–6 at an initial arsenic concentration of 200 μg/L. The mechanisms of the photocatalytic coagulation oxidation of Ti(SO{sub 4}){sub 2} are similar to those of UV/crystalline TiO{sub 2} particles, involving the formation and reactions of the hydroxyl radical OH· and superoxide HO{sub 2}·/O{sub 2}{sup ·−}.

Case Experience of Radiofrequency Ablation for Benign Thyroid Nodules: From an Ex Vivo Animal Study to an Initial Ablation in Taiwan

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Ming-Tsang Lee

2016-03-01

Full Text Available Radiofrequency ablation (RFA is a minimally invasive technique, used with ultrasound or computed tomography guidance, which can produce tissue coagulation necrosis in various kinds of tumors in the human body. In the past 10 years, numerous studies about RFA in benign thyroid nodules have been published. Reviewing these studies, we noticed that the effectiveness of ablation was higher when it was performed with the “moving-shot technique” via an internally cooled electrode. A consensus statement published from the Korean Society of Radiology also suggested the moving-shot technique as a standard ablation procedure for benign thyroid nodule ablation in Korea. In Taiwan, most symptomatic benign nodules are currently treated with surgical removal. RFA for mass lesions is primarily performed for the treatment of metastatic hepatic tumors. In our case, we have attempted to introduce RFA for benign thyroid nodules in Taiwan. Because endocrinologists in Taiwan were not familiar with this technique, we adopted a stepwise approach in learning how to perform RFA. We conducted ex vivo animal ablation exercises to gain experience in setting the radiofrequency generator for the right ablation mode and appropriate power output. The thyroid nodule volume reduction rate after 1 year of follow up was approximately 50% in this case. The most important thing we learned from this trial is that we confirmed the safety of thyroid nodule ablation. To the best of our knowledge, this is the first reported study of RFA of a thyroid nodule in Taiwan.

RETRACTED: Six different hemofiltration devices for blood conservation in cardiac surgery.

Science.gov (United States)

Boldt, J; Zickmann, B; Fedderson, B; Herold, C; Dapper, F; Hempelmann, G

1991-05-01

Hemofiltration devices and the Cell Saver are the most often used techniques to reduce homologous blood requirements in cardiac surgery. In a controlled, randomized study, 105 patients underwent elective aortocoronary bypass grafting. Six different hemofilters (HF-80, HFT 14, CPB 7000, Cobe 1200, UF-205, BC-140) were tested and compared with the Cell Saver (Cell Saver 4) for blood concentration during and after cardiopulmonary bypass. Efficacy, practicality, and laboratory indices including coagulation variables were documented through the morning of the first postoperative day. The HF-80 and UF-205 were the most effective devices for blood concentration. At the end of the operation, the number of platelets was least reduced in these two groups (HF-80, -7%; UF-205, -6%). Moreover, both devices had a significantly higher filtration rate than the other hemofilters. Use of the Cell Saver resulted in the lowest values in coagulation variables (AT-III, fibrinogen, number of platelets) and the most pronounced deterioration in protein homeostasis (colloid osmotic pressure, albumin). In this group, the AT-III concentration was reduced until the morning of the first postoperative day. No negative effects were seen in regard to hemofiltration (free hemoglobin and polymorphonuclear elastase; the Cell Saver group had similar values for these variables). We conclude that blood salvage with hemofiltration devices is superior to that with the Cell Saver. There were, however, significant differences among the hemofilters. The HF-80 and UF-205 were the most effective devices in this study.

Quinine-induced disseminated intravascular coagulation.

Science.gov (United States)

Spearing, R L; Hickton, C M; Sizeland, P; Hannah, A; Bailey, R R

Recurrent disseminated intravascular coagulation occurred in 3 women after ingestion of quinine tablets for cramp. All had circulating quinine-dependent antibodies to platelets and in 2 there was initial evidence of antibody consumption, with low titres that rose steeply over the next few days and remained high for many months.

A natural coagulant protein from Moringa oleifera: isolation, characterization, and potential use for water treatment

Science.gov (United States)

Choudhary, Manisha; Neogi, Sudarsan

2017-10-01

In developing countries pond water is still widely used for drinking and household purposes, which develops higher turbidity during rainy seasons and requires a large amount of chemical coagulants, and this leads to high cost of treatment. To mitigate this, it is important to find an economical and natural coagulant to treat turbid water. The present study is focused on using a plant based component as a natural coagulant that is sustainable and environment-friendly. This work focuses on the extraction, isolation and purification of a natural coagulant from seed kernels of Moringa oleifera to enhance its turbidity removal efficiency. The determination of themolecular weight of the purified proteins was done using sodium dodecyl sulfate polyacrylamide gel electrophoresis. The active coagulant proteins were isolated using 30-60% and 60-80% saturation of ammonium sulfate. It was observed that proteins with molecular weight less than 36 kDa have superior coagulation activity. Turbidity removal efficiency of these active coagulant proteins was compared with alum. The possibility of using Moringa oleifera seeds as a natural antimicrobial agent was also investigated.

Hibiscus rosa- sinensis leaf extract as coagulant aid in leachate treatment

Science.gov (United States)

Awang, Nik Azimatolakma; Aziz, Hamidi Abdul

2012-12-01

Hibiscus rosa- sinensis is a biodegradable material that has remained untested for flocculating properties. The objective of this study is to examine the efficiency of coagulation-flocculation processes for the removal of color, iron (Fe3+), suspended solids, turbidity and ammonia nitrogen(NH3-N), from landfill leachate using 4,000 mg/L alum in conjunction with H. rosa- sinensis leaf extract (HBaqs). Hydroxyl (O-H) and (carboxyl) C=O functional groups along the HBaqs chain help to indulge flocculating efficiency of HBaqs via bridging. The experiments confirm the positive coagulation properties of HBaqs. The Fe3+ removal rate using 4,000 mg/L alum as sole coagulant was approximately 60 %, and increased to 100 % when 4,000 mg/L alum was mixed with 500 mg/L HBaqs. By mixing, 4,000 mg/L alum with 100-500 mg/L HBaqs, 72 % of SS was removed as compared with only 45 % reduction using 4,000 mg/L alum as sole coagulant.

Potential of Hibiscus Sabdariffa and Jatropha Curcas as Natural Coagulants in the Treatment of Pharmaceutical Wastewater

Directory of Open Access Journals (Sweden)

Sibartie Sheena

2018-01-01

Full Text Available Pharmaceutical wastewater is one of the most difficult wastewater to treat due to the presence of pharmaceutical compounds resulting in high concentration of organic matter, high turbidity and Chemical Oxygen Demand (COD. Chemical-based coagulation is a common method used to treat wastewater. However, the issue that has been raised with the use of chemical coagulants is their presence in water after treatment that can cause risks to the human health such as Alzheimer and cancer. Natural coagulants can be used as a safe alternative to these chemicals instead. Therefore, the objective of this experiment was to study the effect of H. Sabdariffa and J. Curcas as natural coagulants, separately and as a combination, on the treatment of pharmaceutical wastewater. Jar test experiment were carried out where beakers of 0.5L wastewater were mixed with the coagulants. The pH of the wastewater was varied from 2 to 12 while the coagulant dosage was varied from 40 to 200 mg/L. It was found that H. Sabdariffa works best at pH 4 and at a coagulant dosage of 190 mg/L with a highest turbidity removal of 35.8% and a decrease of COD by 29%. J. Curcas was found to perform best at pH 3 and with a coagulant dosage of 200 mg/L with a highest turbidity removal of 51% and a decrease of COD by 32%. When J. Curcas and H. Sabdariffa were used in combination, the optimum composition was found to be 80% J. Curcas and 20% H. Sabdariffa by weight with a maximum turbidity removal of 46.8% and a decrease in COD by 46%. In comparison between the two natural coagulants, J. Curcas is found to be a better and more suited coagulative agent for the treatment of pharmaceutical wastewater. The same experiment was carried with alum at pH 6 and coagulant dosage of 750 mg/L and a turbidity removal of 48% and a decrease in COD by 38% were recorded. In comparison with alum, J. Curcas was a better coagulant in treating the pharmaceutical wastewater. This shows that natural coagulants can be

Exact results for the Boltzmann equation and Smoluchowski's coagulation equation

International Nuclear Information System (INIS)

Hendriks, E.M.

1983-01-01

Almost no analytical solutions have been found for realistic intermolecular forces, largely due to the complicated structure of the collision term which calls for the construction of simplified models, in which as many physical properties are maintained as possible. In the first three chapters of this thesis such model Boltzmann equations are studied. Only spatially homogeneous gases with isotropic distribution functions are considered. Chapter I considers transition kernels, chapter II persistent scattering models and chapter III very hard particles. The second part of this dissertation deals with Smoluchowski's coagulation equation for the size distribution function in a coagulating system, with chapters devoted to the following topics: kinetics of gelation and universality, coagulation equations with gelation and exactly soluble models of nucleation. (Auth./C.F.)

A New Radiofrequency Ablation Procedure to Treat Sacroiliac Joint Pain.

Science.gov (United States)

Cheng, Jianguo; Chen, See Loong; Zimmerman, Nicole; Dalton, Jarrod E; LaSalle, Garret; Rosenquist, Richard

2016-01-01

Low back pain may arise from disorders of the sacroiliac joint in up to 30% of patients. Radiofrequency ablation (RFA) of the nerves innervating the sacroiliac joint has been shown to be a safe and efficacious strategy. We aimed to develop a new RFA technique to relieve low back pain secondary to sacroiliac joint disorders. Methodology development with validation through prospective observational non-randomized trial (PONRT). Academic multidisciplinary health care system, Ohio, USA. We devised a guide-block to facilitate accurate placement of multiple electrodes to simultaneously ablate the L5 dorsal ramus and lateral branches of the S1, S2, and S3 dorsal rami. This was achieved by bipolar radiofrequency ablation (b-RFA) to create a strip lesion from the lateral border of the base of the sacral superior articular process (L5-S1 facet joint) to the lateral border of the S3 sacral foramen. We applied this technique in 31 consecutive patients and compared the operating time, x-ray exposure time and dose, and clinical outcomes with patients (n = 62) who have been treated with the cooled radiofrequency technique. Patients' level of pain relief was reported as 80% pain relief at one, 3, 6, and 12 months after the procedure. The relationship between RFA technique and duration of pain relief was evaluated using interval-censored multivariable Cox regression. The new technique allowed reduction of operating time by more than 50%, x-ray exposure time and dose by more than 80%, and cost by more than $1,000 per case. The percent of patients who achieved > 50% pain reduction was significantly higher in the b-RFA group at 3, 6, and 12 months follow-up, compared to the cooled radiofrequency group. No complications were observed in either group. Although the major confounding factors were taken into account in the analysis, use of historical controls does not balance observed and unobserved potential confounding variables between groups so that the reported results are potentially

Disseminated intravascular coagulation in solid tumors

International Nuclear Information System (INIS)

Terzieff, V.; Alonso, I.; Vázquez, A.

2004-01-01

It is estimated that 20-25% of cases of disseminated intravascular coagulation (DIC) relate to an underlying neoplasia primarily hematologic. It is estimated that about 5% of patients with solid tumors have CID clinic, although the incidence of subclinical alterations is much higher. The CID is not limited to the activation of the coagulation cascade, which leads to bleeding micro thrombosis and consumption of coagulation factors. Solid tumors are frequently associated adenocarcinomas producers mucin (especially gastric), usually in the context of a disseminated disease. The mucin may act as a promoter of the cascade, but probably it is a multi-event. High levels of TNF to produced by the tumor mass and chemotherapy-induced cell lysis have Also linked. Although the bleeding is usually oriented diagnosis, the most frequent cause of death is thrombosis. There are no specific tests for diagnosis. Elevated levels of D-dimer and products oriented fibrinogen degradation diagnosis. No reduction fibrinogen and almost always, one thrombocytopenia consumption. Treatment is complex and there is no consensus on many points. To recover the lost factors for consumption, it is recommended to use fresh frozen plasma and / or washed red blood cells. the heparin anticoagulation low dose is indicated since the disease causal can not be controlled quickly, but should not be initiated if there thrombocytopenia 50.000.El under profuse bleeding can require the use of tranexamic acid or EACA. Acute DIC, the case of our patient, is rare and very serious

Cooling system for the IFMIF-EVEDA radiofrequency system

International Nuclear Information System (INIS)

Perez Pichel, G. D.

2012-01-01

The IFMIF-EVEDA project consists on an accelerator prototype that will be installed at Rokkasho (Japan). Through CIEMAT, that is responsible of the development of many systems and components. Empresarios Agrupados get the responsibility of the detailed design of the cooling system for the radiofrequency system (RF system) that must feed the accelerator. the RF water cooling systems is the water primary circuit that provides the required water flow (with a certain temperature, pressure and water quality) and also dissipates the necessary thermal power of all the radiofrequency system equipment. (Author) 4 refs.

Enhanced coagulation for turbidity and Total Organic Carbon (TOC) removal from river Kansawati water.

Science.gov (United States)

Narayan, Sumit; Goel, Sudha

2011-01-01

The objective of this study was to determine optimum coagulant doses for turbidity and Total Organic Carbon (TOC) removal and evaluate the extent to which TOC can be removed by enhanced coagulation. Jar tests were conducted in the laboratory to determine optimum doses of alum for the removal of turbidity and Natural Organic Matter (NOM) from river water. Various other water quality parameters were measured before and after thejar tests and included: UV Absorbance (UVA) at 254 nm, microbial concentrations, TDS, conductivity, hardness, alkalinity, and pH. The optimum alum dose for removal of turbidity and TOC was 20 mg/L for the sample collected in November 2009 and 100 mg/L for the sample collected in March 2010. In both cases, the dose for enhanced coagulation was significantly higher than that for conventional coagulation. The gain in TOC removal was insignificant compared to the increase in coagulant dose required. This is usual for low TOC (TOC need to be tested to demonstrate the effectiveness of enhanced coagulation.

A simple purification and activity assay of the coagulant protein from Moringa oleifera seed.

Science.gov (United States)

Ghebremichael, Kebreab A; Gunaratna, K R; Henriksson, Hongbin; Brumer, Harry; Dalhammar, Gunnel

2005-06-01

Use of extracts from Moringa oleifera (MO) is of great interest for low-cost water treatment. This paper discusses water and salt extraction of a coagulant protein from the seed, purification using ion exchange, its chemical characteristics, coagulation and antimicrobial properties. The coagulant from both extracts is a cationic protein with pI greater than 9.6 and molecular mass less than 6.5 kDa. Mass spectrometric analysis of the purified water extract indicated that it contained at least four homologous proteins, based on MS/MS peptide sequence data. The protein is thermoresistant and remained active after 5h heat treatment at 95 degrees C. The coagulant protein showed both flocculating and antibacterial effects of 1.1--4 log reduction. With samples of high turbidity, the MO extract showed similar coagulation activity as alum. Cecropin A and MO extract were found to have similar flocculation effects for clay and microorganisms. Simple methods for both the purification and assay of MO coagulating proteins are presented, which are necessary for large-scale water treatment applications.

Study on the method and mechanism of pre-pressure coagulation and sedimentation for Microcystis removal from drinking-water sources.

Science.gov (United States)

Cong, Haibing; Sun, Feng; Chen, Wenjing; Xu, Yajun; Wang, Wei

2018-02-01

In order to effectively remove the Microcystis from drinking-water sources, pre-pressure treatment was first used to make the Microcystis lose buoyancy, and then it is easily removed by coagulation and sedimentation processes. The Microcystis-containing water from Taihu Lake was taken for the pre-pressure coagulation and sedimentation treatments in this study. Both intermittent laboratory experiment and continuous-flow field experiment were conducted. Experimental results showed that the optimum pre-pressure condition was pressuring at 0.6-0.8 MPa for at least 10 s, and 60 s was the best. Comparing with the pre-oxidation, pre-pressure could obviously increase the removal efficiency of Microcystis by following coagulation and sedimentation, and would not increase the dissolved microcystins. The mechanism of pre-pressure treatment was that the pre-pressure destroys the gas vesicles in Microcystis cells and the gas diffuses out of the cells, which leads the Microcystis to lose buoyancy and make them to sink. The recovery time of gas vesicles was longer than the sludge discharge period of sedimentation tank; therefore, the sinking Microcystis would not re-float in the sedimentation tank. In the practical application of drinking water treatment plant, the continuous-flow pressure device could be chosen, with the energy consumption of about 22.9 kw·h per 10,000 m 3 .

OPTIMIZATION OF FLOCCULATION PROCESS BY MICROBIAL COAGULANT IN RIVER WATER

Directory of Open Access Journals (Sweden)

Fatin Nabilah Murad

2017-12-01

Full Text Available The existing process of coagulation and flocculation are using chemicals that known as cationic coagulant such as alum, ferric sulfate, calcium oxide, and organic polymers.  Thus, this study concentrates on optimizing of flocculation process by microbial coagulant in river water. Turbidity and suspended solids are the main constraints of river water quality in Malaysia. Hence, a study is proposed to produce microbial coagulants isolated locally for river water treatment. The chosen microbe used as the bioflocculant producer is Aspergillus niger. The parameters to optimization in the flocculation process were pH, bioflocculant dosage and effluent concentration. The research was done in the jar test process and the process parameters for maximum turbidity removal was validated. The highest flocculating activity was obtained on day seven of cultivation in the supernatant. The optimum pH and bioflocculant dosage for an optimize sedimentation process were between 4-5 and 2-3 mL for 0.3 g/L of effluent concentration respectively. The model was validated by using a river water sample from Sg. Pusu and the result showed that the model was acceptable to evaluate the bioflocculation process.

Investigation of high sensitivity radio-frequency readout circuit based on AlGaN/GaN high electron mobility transistor

International Nuclear Information System (INIS)

Zhang Xiao-Yu; Sun Jian-Dong; Li Xin-Xing; Zhou Yu; Lü Li; Qin Hua; Tan Ren-Bing

2015-01-01

An AlGaN/GaN high electron mobility transistor (HEMT) device is prepared by using a semiconductor nanofabrication process. A reflective radio-frequency (RF) readout circuit is designed and the HEMT device is assembled in an RF circuit through a coplanar waveguide transmission line. A gate capacitor of the HEMT and a surface-mounted inductor on the transmission line are formed to generate LC resonance. By tuning the gate voltage V g , the variations of gate capacitance and conductance of the HEMT are reflected sensitively from the resonance frequency and the magnitude of the RF reflection signal. The aim of the designed RF readout setup is to develop a highly sensitive HEMT-based detector. (paper)

Blood coagulation in lead poisoning and the influence of specific treatment

Energy Technology Data Exchange (ETDEWEB)

Levantovskaya, O M; Lyubcenko, P N; Dayhin, I S; Sorkina, N S

1974-07-01

Results of blood coagulation studies in 104 workers with long-term exposure in a storage-battery plant. Over-all coagulation activity is unchanged in cases of mild lead poisoning, but long-term exposure gives rise to increased fibrinogen levels, activated fibrinolysis, and reduced serum accelerator globulin and prothrombin activities. 13 workers were given D-penicillamine (oral doses of 450 mg daily). All coagulation indices had become normal after 10 days' treatment. The changes observed are thought to be due to protein synthesis disturbances in the liver and to inhibition of enzymes by lead which combines with their sulfhydryl and disulfide groups. (CIS Abstr. Vol. 2)

Analysis of public perception of increased radiofrequency exposure from mobile phone in Southwestern Nigeria

International Nuclear Information System (INIS)

Oladapo, O.O.; Ishola, G.A.; Ayokunnnu, D.O.

2011-01-01

Wireless communication devices have been increasingly used recently in Nigeria with a corresponding public perception of increase in radiofrequency (RF) radiation. This perception has developed into public concerns, thus requiring verification. For the purpose of verification, a survey in form of an opinion poll was conducted by means of an interview using questionnaires. The survey shows that people actually experienced symptoms like headache, fatigue, dizziness, and heat sensation. However, out of the respondents that have experienced one symptoms or the other, 84% still believe it is safe to use mobile phones. Only 4 % of those that claimed they experienced symptoms had consulted a doctor in connection with the symptoms.

Removal of chemical oxygen demand from textile wastewater using a natural coagulant

Energy Technology Data Exchange (ETDEWEB)

Ramavandi, Bahman [Bushehr University of Medical Sciences, Bushehr (Iran, Islamic Republic of); Farjadfard, Sima [Islamic Azad University, Tehran (Iran, Islamic Republic of)

2014-01-15

A biomaterial was successfully synthesized from Plantago ovata by using an FeCl{sub 3}-induced crude extract (FCE). The potential of FCE to act as a natural coagulant was tested for the pretreatment of real textile wastewater. Tests were performed to evaluate the effects of FCE quantity, salt concentration, and wastewater pH on chemical oxygen demand (COD) reduction during a coagulation/flocculation process. Experimental results indicated that the wastewater could be effectively treated by using a coagulation/flocculation process, where the BOD{sub 5}/COD ratio of the effluent was improved to 0.48. A low coagulant dose, 1.5mg/L, achieved a high COD removal percentage, 89%, at operational conditions of neutral pH and room temperature. The experimental data revealed that the maximum COD removal occurred at water pH<8. Increasing the salt promoted the COD removal. The settling and filterability characteristics of the sludge were also studied. Scanning electron microscopy and energy dispersive spectroscopy studies were conducted to determine the sludge structure and composition, respectively. Overall, FCE as an eco-friendly biomaterial was revealed to be a very efficient coagulant and a promising option for the removal of COD from wastewaters.

Reincarnation of ancient links between coagulation and complement.

Science.gov (United States)

Conway, E M

2015-06-01

Throughout evolution, organisms have developed means to contain wounds by simultaneously limiting bleeding and eliminating pathogens and damaged host cells via the recruitment of innate defense mechanisms. Disease emerges when there is unchecked activation of innate immune and/or coagulation responses. A key component of innate immunity is the complement system. Concurrent excess activation of coagulation and complement - two major blood-borne proteolytic pathways - is evident in numerous diseases, including atherosclerosis, diabetes, venous thromboembolic disease, thrombotic microangiopathies, arthritis, cancer, and infectious diseases. Delineating the cross-talk between these two cascades will uncover novel therapeutic insights. © 2015 International Society on Thrombosis and Haemostasis.

Arthroscopic surgery using radio-frequency electrocautery

International Nuclear Information System (INIS)

Takatsuka, Shigeyuki; Yoshida, Kan; Nakagawa, Kiyomasa; Yamamoto, Etsuhide; Kubota, Yoshiyuki; Narinobou, Masayoshi; Terai, Koichi; Hasegawa, Hiroshi

2008-01-01

Arthroscopic surgery using radio-frequency electrocautery was carried out on 23 temporomandibular joints (TMJs) in 13 patients. Because these patients did not respond to conservative therapy, surgery was indicated. Preoperative MRI showed anterior disc displacement without reduction in all patients. Disturbed translation was also recognized in all of the discs and mandibular condyles. Intraoperative arthroscopic examination showed severe fibrous adhesion in the upper joint compartment and disc displacement. Four joints showed perforation between the disc and retrodiscal tissue. Postoperative findings included an increased range of vertical maximal mouth opening and decreased pain on mandibular movement. Analyses of postoperative MRI indicated recovery of disc and condylar translation. These results suggested that the introduction of arthroscopic surgery using radiofrequency electrocautery would significantly reduce the number of patients with osteoarthritic TMJ disorders. (author)

Comparison of single-step and two-step purified coagulants from Moringa oleifera seed for turbidity and DOC removal.

Science.gov (United States)

Sánchez-Martín, J; Ghebremichael, K; Beltrán-Heredia, J

2010-08-01

The coagulant proteins from Moringa oleifera purified with single-step and two-step ion-exchange processes were used for the coagulation of surface water from Meuse river in The Netherlands. The performances of the two purified coagulants and the crude extract were assessed in terms of turbidity and DOC removal. The results indicated that the optimum dosage of the single-step purified coagulant was more than two times higher compared to the two-step purified coagulant in terms of turbidity removal. And the residual DOC in the two-step purified coagulant was lower than in single-step purified coagulant or crude extract. (c) 2010 Elsevier Ltd. All rights reserved.

Performance of alum and assorted coagulants in turbidity removal of muddy water

Science.gov (United States)

Malik, Qasim H.

2018-03-01

Coagulation is a primary and cost effective process in water treatment plants. Under optimum conditions, not only it effectively removes turbidity but also results in reduced sludge volume and subsequently minimizes sludge management costs. Highly turbid water from streams, canals, rivers and rain run offs was run through jar test for turbidity removal. The brown water with 250NTU turbidity when coagulated with alum and assorted coagulants proved that maximum turbidity removal was witnessed using alum dose of 0.25 g/l at ph 6 with a sedimentation time of 30 min.

Early markers of blood coagulation and fibrinolysis activation in Argentine hemorrhagic fever

NARCIS (Netherlands)

Heller, M. V.; Marta, R. F.; Sturk, A.; Maiztegui, J. I.; Hack, C. E.; Cate, J. W.; Molinas, F. C.

1995-01-01

Junin virus, an arenaviridae, is the etiological agent of Argentine hemorrhagic fever. In addition to thrombocytopenia, patients present several alterations in both the blood coagulation and the fibrinolytic system, but diffuse intravascular coagulation could not be demonstrated. To investigate

Effect of variable heat transfer coefficient on tissue temperature next to a large vessel during radiofrequency tumor ablation

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Pinheiro Cleber

2008-07-01

Full Text Available Abstract Background One of the current shortcomings of radiofrequency (RF tumor ablation is its limited performance in regions close to large blood vessels, resulting in high recurrence rates at these locations. Computer models have been used to determine tissue temperatures during tumor ablation procedures. To simulate large vessels, either constant wall temperature or constant convective heat transfer coefficient (h have been assumed at the vessel surface to simulate convection. However, the actual distribution of the temperature on the vessel wall is non-uniform and time-varying, and this feature makes the convective coefficient variable. Methods This paper presents a realistic time-varying model in which h is a function of the temperature distribution at the vessel wall. The finite-element method (FEM was employed in order to model RF hepatic ablation. Two geometrical configurations were investigated. The RF electrode was placed at distances of 1 and 5 mm from a large vessel (10 mm diameter. Results When the ablation procedure takes longer than 1–2 min, the attained coagulation zone obtained with both time-varying h and constant h does not differ significantly. However, for short duration ablation (5–10 s and when the electrode is 1 mm away from the vessel, the use of constant h can lead to errors as high as 20% in the estimation of the coagulation zone. Conclusion For tumor ablation procedures typically lasting at least 5 min, this study shows that modeling the heat sink effect of large vessels by applying constant h as a boundary condition will yield precise results while reducing computational complexity. However, for other thermal therapies with shorter treatment using a time-varying h may be necessary.

Matriptase activation connects tissue factor-dependent coagulation initiation to epithelial proteolysis and signaling.

Science.gov (United States)

Le Gall, Sylvain M; Szabo, Roman; Lee, Melody; Kirchhofer, Daniel; Craik, Charles S; Bugge, Thomas H; Camerer, Eric

2016-06-23

The coagulation cascade is designed to sense tissue injury by physical separation of the membrane-anchored cofactor tissue factor (TF) from inactive precursors of coagulation proteases circulating in plasma. Once TF on epithelial and other extravascular cells is exposed to plasma, sequential activation of coagulation proteases coordinates hemostasis and contributes to host defense and tissue repair. Membrane-anchored serine proteases (MASPs) play critical roles in the development and homeostasis of epithelial barrier tissues; how MASPs are activated in mature epithelia is unknown. We here report that proteases of the extrinsic pathway of blood coagulation transactivate the MASP matriptase, thus connecting coagulation initiation to epithelial proteolysis and signaling. Exposure of TF-expressing cells to factors (F) VIIa and Xa triggered the conversion of latent pro-matriptase to an active protease, which in turn cleaved the pericellular substrates protease-activated receptor-2 (PAR2) and pro-urokinase. An activation pathway-selective PAR2 mutant resistant to direct cleavage by TF:FVIIa and FXa was activated by these proteases when cells co-expressed pro-matriptase, and matriptase transactivation was necessary for efficient cleavage and activation of wild-type PAR2 by physiological concentrations of TF:FVIIa and FXa. The coagulation initiation complex induced rapid and prolonged enhancement of the barrier function of epithelial monolayers that was dependent on matriptase transactivation and PAR2 signaling. These observations suggest that the coagulation cascade engages matriptase to help coordinate epithelial defense and repair programs after injury or infection, and that matriptase may contribute to TF-driven pathogenesis in cancer and inflammation.

An assessment of the utility of unselected coagulation screening in general hospital practice.

LENUS (Irish Health Repository)

McHugh, Johnny

2011-03-01

Coagulation screening using prothrombin time (PT) and activated partial thromboplastin time (APTT) is widely used. We performed an audit of coagulation screening in an Irish teaching hospital. We analysed PT and\\/or APTT results received during normal working hours during a 1-week period in our hospital. Abnormal results due to anticoagulants were excluded from further study. In samples with PT longer than 15.5 s and\\/or APTT longer than 42 s, we proceeded to 1: 1 mixing studies if the PT was prolonged and 1: 1 mixing studies, factor XII assay and lupus screen if the APTT was prolonged. We also obtained referral source for all samples and clinical details for abnormal samples. Six hundred and seventy-one coagulation requests were received during the study period. Three hundred and eighteen of 671 (47.4%) coagulation requests were for monitoring of anticoagulation. Three hundred and fifty-three of 671 (52.6%) requests were for coagulation screening rather than anticoagulant monitoring. In the coagulation screens received, PT was prolonged in 19 of 353 (5.4%). PT was longer than 20 s in four of 353 cases (1.1%). APTT was prolonged in 19 of 353 (5.4%). APTT was longer than 50 s in four of 353 (1.1%). No patients with abnormal PT or APTT had any bleeding sequelae during the study period. Unregulated coagulation screening has a low yield of abnormal results; the majority of these abnormal results show mild prolongation of PT or APTT with no evidence that they are associated with an increased bleeding risk.

MR images of radiofrequency lesions following ventrolateral thalamotomy

Energy Technology Data Exchange (ETDEWEB)

Shinno, Kiyohito [Tokushima Univ. (Japan). School of Medicine

1992-10-01

In 14 patients with Parkinson's disease and one with intension tremor, thalamotomy lesions were examined with magnetic resonance (MR) imaging at acute (day 3), subacute (day 14), and chronic (2 months to 1 year) stages after surgery. Standard radiofrequency lesion-making was repeated up to a complete abolition of motor symptoms. At acute stage, three or four distinct zones of the thalamus were seen on MR images: the central and third zones were of low signal on T1- and high signal on T2-weighted images; and the second zone was isointense on T1- and of low signal on T2-weighted images. The out-most zone was of high signal on T2-weighted images, but not noticeable on T1-weighted images. MR appearances at subacute stage showed hyperintensity on T1- and T2-weighted images for both the central and third zones. The second zone became smaller and fainter, although there was no signal change. The out-most zone became much smaller on T2-weighted images and was invisible on T1-weighted images. At subacute stage, T2-weighted images showed two distinct layers: the inner layer was of high signal and the outer layer was of low signal. T1-weighted imaging showed mixed isointensity and hyperintensity. At chronic stage one year after surgery, the lesions became small, round cystic with low signal on T1- and either low or high signal on T2-weighted images. At acute stage, the central, second, and third zones seemed reflect a small area of needle destruction composed of blood and edema, a layer of coagulation necrosis, and a layer of hemorrhagic colliquation necrosis with edema, respectively. Water content increased due to edema at acute stage; and hemoglobin changed paramagentic forms in association with diminution of edema in subacute or chronic stage.(N.K.).

Development of a magnetic coagulant based on Moringa oleifera seed extract for water treatment.

Science.gov (United States)

Santos, Tássia R T; Silva, Marcela F; Nishi, Leticia; Vieira, Angélica M S; Fagundes-Klen, Márcia R; Andrade, Murilo B; Vieira, Marcelo F; Bergamasco, Rosângela

2016-04-01

In this work, to evaluate the effectiveness of the coagulation/flocculation using a natural coagulant, using Moringa oleifera Lam functionalized with magnetic iron oxide nanoparticles, producing flakes that are attracted by an external magnetic field, thereby allowing a fast settling and separation of the clarified liquid, is proposed. The removal efficiency of the parameters, apparent color, turbidity, and compounds with UV254nm absorption, was evaluated. The magnetic functionalized M. oleifera Lam coagulant could effectively remove 90 % of turbidity, 85 % of apparent color, and 50 % for the compounds with absorption at UV254nm, in surface waters under the influence of an external magnetic field within 30 min. It was found that the coagulation/flocculation treatment using magnetic functionalized M. oleifera Lam coagulant was able to reduce the values of the physico-chemical parameters evaluated with reduced settling time.

Initiator Systems Effect on Particle Coagulation and Particle Size Distribution in One-Step Emulsion Polymerization of Styrene

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Baijun Liu

2016-02-01

Full Text Available Particle coagulation is a facile approach to produce large-scale polymer latex particles. This approach has been widely used in academic and industrial research owing to its higher polymerization rate and one-step polymerization process. Our work was motivated to control the extent (or time of particle coagulation. Depending on reaction parameters, particle coagulation is also able to produce narrowly dispersed latex particles. In this study, a series of experiments were performed to investigate the role of the initiator system in determining particle coagulation and particle size distribution. Under the optimal initiation conditions, such as cationic initiator systems or higher reaction temperature, the time of particle coagulation would be advanced to particle nucleation period, leading to the narrowly dispersed polymer latex particles. By using a combination of the Smoluchowski equation and the electrostatic stability theory, the relationship between the particle size distribution and particle coagulation was established: the earlier the particle coagulation, the narrower the particle size distribution, while the larger the extent of particle coagulation, the larger the average particle size. Combined with the results of previous studies, a systematic method controlling the particle size distribution in the presence of particle coagulation was developed.

Ion collection from laser-induced plasma by applying radio-frequency voltage

International Nuclear Information System (INIS)

Shibata, Takemasa; Ogura, Koichi

1995-01-01

Ions were collected on the electrodes from a laser resonance photoionized plasma by applying 1.8MHz radio-frequency voltage to the electrode. It was demonstrated that the ions are collected in a shorter time at the same kinetic energy of the collected ions compared with ion collection by applying DC voltage to the electrode. A simple one-dimensional model was extended for prediction of ion collection times in the cases of applications of not only the DC voltage but also the radio-frequency voltage. The ion collection times estimated using the simple one-dimensional model agreed with experimental values in both cases of DC and radio-frequency voltages. (author)

Moringa oleifera-mediated coagulation of textile wastewater and its biodegradation using novel consortium-BBA grown on agricultural waste substratum.

Science.gov (United States)

Bedekar, Priyanka A; Bhalkar, Bhumika N; Patil, Swapnil M; Govindwar, Sanjay P

2016-10-01

Generation of secondary sludge is a major concern of textile dye removal by coagulation process. Combinatorial coagulation-biodegradation treatment system has been found efficient in degradation of coagulated textile dye sludge. Moringa oleifera seed powder (700 mg L -1 ) was able to coagulate textile dyestuff from real textile wastewater with 98 % color removal. Novel consortium-BBA was found to decolorize coagulated dye sludge. Parameters that significantly affect coagulation process were optimized using response surface methodology. The bench-scale stirred tank reactor (50-L capacity) designed with optimized parameters for coagulation process could efficiently remove 98, 89, 78, and 67 % of American Dye Manufacturer's Institute (ADMI) in four repetitive cycles, respectively. Solid-state fermentation composting reactor designed to treat coagulated dye sludge showed 96 % removal of dye within 10 days. Coagulation of dyes from textile wastewater and degradation of coagulated dye sludge were confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. Cell morphology assay, comet assay, and phytotoxicity confirmed the formation of less toxic products after coagulation and degradation mechanism.

The effects of chemical coagulants on the decolorization of dyes by electrocoagulation using response surface methodology (RSM)

Science.gov (United States)

Butler, Erick B.; Hung, Yung-Tse; Mulamba, Oliver

2017-09-01

This study assessed the efficiency of electrocoagulation (ECF) coupled with an addition of chemical coagulant to decolorize textile dye. Tests were conducted using Box Behnken methodology to vary six parameters: dye type, weight, coagulant type, dose, initial pH and current density. The combination of electrocoagulation and chemical coagulation was able to decolorize dye up to 99.42 % in 30 min of treatment time which is remarkably shorter in comparison with using conventional chemical coagulation. High color removal was found to be contingent upon the dye type and current density, along with the interactions between the current density and the coagulant dose. The addition of chemical coagulants did enhanced treatment efficiency.

Coagulation measurement from whole blood using vibrating optical fiber in a disposable cartridge.

Science.gov (United States)

Yaraş, Yusuf Samet; Gündüz, Ali Bars; Sağlam, Gökhan; Ölçer, Selim; Civitçi, Fehmi; Baris, İbrahim; Yaralioğlu, Göksenin; Urey, Hakan

2017-11-01

In clinics, blood coagulation time measurements are performed using mechanical measurements with blood plasma. Such measurements are challenging to do in a lab-on-a-chip (LoC) system using a small volume of whole blood. Existing LoC systems use indirect measurement principles employing optical or electrochemical methods. We developed an LoC system using mechanical measurements with a small volume of whole blood without requiring sample preparation. The measurement is performed in a microfluidic channel where two fibers are placed inline with a small gap in between. The first fiber operates near its mechanical resonance using remote magnetic actuation and immersed in the sample. The second fiber is a pick-up fiber acting as an optical sensor. The microfluidic channel is engineered innovatively such that the blood does not block the gap between the vibrating fiber and the pick-up fiber, resulting in high signal-to-noise ratio optical output. The control plasma test results matched well with the plasma manufacturer's datasheet. Activated-partial-thromboplastin-time tests were successfully performed also with human whole blood samples, and the method is proven to be effective. Simplicity of the cartridge design and cost of readily available materials enable a low-cost point-of-care device for blood coagulation measurements. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Effect of Radiofrequency Endometrial Ablation on Dysmenorrhea.

Science.gov (United States)

Wyatt, Sabrina N; Banahan, Taylor; Tang, Ying; Nadendla, Kavita; Szychowski, Jeff M; Jenkins, Todd R

To examine rates of dysmenorrhea after radiofrequency endometrial ablation in patients with and without known dysmenorrhea symptoms prior to the procedure in a diverse population. Retrospective cohort study (Canadian Task Force classification II-2). Academic gynecology practice. A total of 307 women underwent endometrial ablation between 2007 and 2013 at our institution. Patients who had preoperative and postoperative pain symptom assessments as well as a description of pain timing recorded were included in our analysis. Exclusion criteria were age dysmenorrhea was evaluated. Demographic information and other outcome variables were used to evaluate factors associated with resolution of dysmenorrhea. A total of 307 patients who underwent radiofrequency endometrial ablation were identified. After exclusions, 296 charts were examined, and 144 patients met our enrollment criteria. The mean age of the study cohort was 45.4 ± 6.2 years; 57 patients (40%) were African American, 16 (11%) had a body mass index (BMI) > 40, and 41 (29%) were of normal weight. Preoperative dysmenorrhea was reported by 100 patients (69%); 48 of these patients (48%) experienced resolution of symptoms postoperatively. Only 3 of the 44 patients (7%) without preoperative dysmenorrhea reported new-onset dysmenorrhea postoperatively. Significantly fewer patients had dysmenorrhea after compared to before radiofrequency ablation (55 of 144 [38%] vs 100 of 144 [69%]; p dysmenorrhea after ablation was associated with reduction in bleeding volume (p = .048) but not with a reduction in frequency of bleeding (p = .12). Approximately one-half of women who undergo radiofrequency endometrial ablation to treat heavy menstrual bleeding who also have preoperative dysmenorrhea exhibit documented pain resolution after the procedure. Resolution of dysmenorrhea is more likely if menstrual flow volume is decreased postprocedure. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

Chronic sleep deprivation markedly reduces coagulation factor VII expression

Science.gov (United States)

Pinotti, Mirko; Bertolucci, Cristiano; Frigato, Elena; Branchini, Alessio; Cavallari, Nicola; Baba, Kenkichi; Contreras-Alcantara, Susana; Ehlen, J. Christopher; Bernardi, Francesco; Paul, Ketema N.; Tosini, Gianluca

2010-01-01

Chronic sleep loss, a common feature of human life in industrialized countries, is associated to cardiovascular disorders. Variations in functional parameters of coagulation might contribute to explain this relationship. By exploiting the mouse model and a specifically designed protocol, we demonstrated that seven days of partial sleep deprivation significantly decreases (−30.5%) the thrombin generation potential in plasma evaluated upon extrinsic (TF/FVIIa pathway) but not intrinsic activation of coagulation. This variation was consistent with a decrease (−49.8%) in the plasma activity levels of factor VII (FVII), the crucial physiologicalal trigger of coagulation, which was even more pronounced at the liver mRNA level (−85.7%). The recovery in normal sleep conditions for three days completely restored thrombin generation and FVII activity in plasma. For the first time, we demonstrate that chronic sleep deprivation on its own reduces, in a reversible manner, the FVII expression levels, thus influencing the TF/FVIIa activation pathway efficiency. PMID:20418241

Ventricular metastasis resulting in disseminated intravascular coagulation

Directory of Open Access Journals (Sweden)

Davis Ian D

2005-05-01

Full Text Available Abstract Background Disseminated Intravascular Coagulation (DIC complicates up to 7% of malignancies, the commonest solid organ association being adenocarcinoma. Transitional Cell Carcinoma (TCC has rarely been associated with DIC. Case presentation A 74-year-old woman with TCC bladder and DIC was found to have a cardiac lesion suspicious for metastatic disease. The DIC improved with infusion of plasma and administration of Vitamin K, however the cardiac lesion was deemed inoperable and chemotherapy inappropriate; given the patients functional status. We postulate that direct activation of the coagulation cascade by the intraventricular metastasis probably triggered the coagulopathy in this patient. Conclusion Cardiac metastases should be considered in cancer patients with otherwise unexplained DIC. This may influence treatment choices.

EFFECTIVENESS OF CHITOSAN AS NATURAL COAGULANT AID IN TREATING TURBID WATERS

Directory of Open Access Journals (Sweden)

B. Bina ، M. H. Mehdinejad ، M. Nikaeen ، H. Movahedian Attar

2009-10-01

Full Text Available During the last decade, there has been a concern about the relation between aluminum residuals in treated water and Alzheimer disease, and more interest has been considered on the development of natural coagulants such as chitosan. Chitosan, a natural linear biopolyaminosaccharide, is obtained by alkaline deacetylation of chitin. The present study was aimed to investigate the effects of alum as coagulant in conjunction with chitosan as coagulant aid on the removal of turbidity, hardness and Escherichia coli from water. A conventional jar test apparatus was employed for the tests. The optimum pH was observed between 7 to 7.5 for all turbidities. The optimum doses of alum and chitosan when used in conjunction, were 10mg/L and 1mg/L, 5mg/L and 0.5mg/L, and 5mg/L and 0.5mg/L in low, medium and high turbidities, respectively. Turbidity removal efficiency was resulted between %74.3 to %98.2 by alum in conjunction with chitosan. Residual Al+3 in treated water was less than 0.2 mg/L, meeting the international guidelines. The results showed that turbidity decrease provided also a primary Escherichia coli reduction of 2-4 log units within the first 1 to 2 hr of treatment. Hardness removal efficiency decreased when the total hardness increased from 102 to 476mg/L as CaCO3. At low initial turbidity, chitosan showed marginally better performance on hardness, especially at the ranges of 100 to 210 mg/L as CaCO3. In conclusion, coagulant aid showed a useful method for coagulation process. By using natural coagulants, considerable savings in chemicals and sludge handling cost may be achieved.

Self-production of tissue factor-coagulation factor VII complex by ovarian cancer cells

OpenAIRE

Yokota, N; Koizume, S; Miyagi, E; Hirahara, F; Nakamura, Y; Kikuchi, K; Ruf, W; Sakuma, Y; Tsuchiya, E; Miyagi, Y

2009-01-01

Background: Thromboembolic events are a major complication in ovarian cancer patients. Tissue factor (TF) is frequently overexpressed in ovarian cancer tissue and correlates with intravascular thrombosis. TF binds to coagulation factor VII (fVII), changing it to its active form, fVIIa. This leads to activation of the extrinsic coagulation cascade. fVII is produced by the liver and believed to be supplied from blood plasma at the site of coagulation. However, we recently showed that ovarian ca...

Identification of coagulation gene 3′UTR variants that are potentially regulated by microRNAs

NARCIS (Netherlands)

Vossen, Carla Y.; van Hylckama Vlieg, Astrid; Teruel-Montoya, Raúl; Salloum-Asfar, Salam; de Haan, Hugoline G.; Corral, Javier; Reitsma, Pieter H.; Koeleman, Bobby P.C.; Martínez, Constantino

2017-01-01

MicroRNAs have been recognized as critical regulators of gene expression and might affect the risk of venous thrombosis. We aimed to identify 3′ untranslated region (UTR) variants in coagulation genes that influence coagulation factor levels and venous thrombosis risk. The 3′UTR of coagulation genes

The hydrophilic/hydrophobic ratio vs. dissolved organics removal by coagulation – A review

Directory of Open Access Journals (Sweden)

Djamel Ghernaout

2014-07-01

Full Text Available This review discusses the hydrophilic/hydrophobic ratio as a function of the hydrophilic and hydrophobic contents removal by coagulation process. It is well established that coagulation process could bring a reduction in dissolved organic carbon of around 30–60% by increasing the coagulant dose and optimising reaction pH, in which large organic molecules with hydrophobic property was removed preferentially. Furthermore, the literature affirmed that the greater removal of UV-absorbing substances indicates that alum coagulation preferentially removed the hydrophobic fraction of the total organic carbon. For the hydrophobic fraction, it needs to be removed entirely without its transformation into hydrophilic fractions by coagulation process avoiding pre-chlorination/pre-oxidation due to the risk of organic molecules fragmentation. Determining the exact numerical values of the hydrophilic/hydrophobic ratio for raw water and treated water at different stages of the treatment processes in a water treatment plant, as for the DCO/DBO5 ratio in the case of wastewater treatment, would help on more focusing on OM control and removal.

Study on Coagulant Dosing Control System of Micro Vortex Water Treatment

Science.gov (United States)

Fengping, Hu; Qi, Fan; Wenjie, Hu; Xizhen, He; Hongling, Dai

2018-03-01

In view of the characteristics of nonlinearity, large time delay and multi disturbance in the process of coagulant dosing in water treatment, it is difficult to control the dosage of coagulant. According to the four indexes of raw water quality parameters (raw water flow, turbidity, pH value) and turbidity of sedimentation tank, the micro vortex coagulation dosing control model is constructed based on BP neural network and GA. The forecast results of BP neural network model are ideal, and after the optimization of GA, the prediction accuracy of the model is partly improved. The prediction error of the optimized network is ±0.5 mg/L, and has a better performance than non-optimized network.

Comparative study of conventional US, contrast enhanced US and enhanced MR for the follow-up of prostatic radiofrequency ablation.

Science.gov (United States)

Feng, Chao; Hu, Bin; Hu, Bing; Chen, Lei; Li, Jia; Huang, Jin

2017-06-01

The aim of the present study was to evaluate and compare the effectiveness of different imaging methods during follow-up of prostatic radiofrequency ablation. Prostatic radiofrequency ablation (RFA) was performed in 20 healthy beagle dogs. Various imaging examinations were used to monitor the results of RFA, including conventional ultrasound (US), contrast enhanced ultrasound (CEUS) and enhanced magnetic resonance (MR). Imaging exams were performed at five phases: Immediately following RFA, one week later, one month later, three months later and six months later. The morphology for each imaging test and histological results were recorded and compared in each phase. Based on the actual results from autopsy, the accuracy of those imaging exams was evaluated. The canine prostate gland demonstrated typical coagulative necrosis immediately following RFA. The lesion would develop into stable cyst if no other complications occurred within the six-month follow-up. Regarding the RFA lesion volume measurement and the reflection of pathological changes, conventional US was not able to accurately measure the volume of RFA lesion and missed many more details concerning the RFA-treated area than CEUS and MR during the three months. The results from CEUS exhibited comparable accuracy to those from enhanced MR at each phase. However, there were no significant differences in the results from US, CEUS and MR at six months, which may contribute to the complete formation of lesion cyst. In the early phase, conventional US was not sufficient for evaluating the efficacy of RFA. Enhanced US and MR provided clear images and accurate information. However, CEUS has the advantage of being more economical, using more convenient equipment and faster scanning, thus identifying it as the more feasible choice. Furthermore, no notable advantages were observed among any image examinations in the long-term follow-up.

Blood viscosity during coagulation at different shear rates

Science.gov (United States)

Ranucci, Marco; Laddomada, Tommaso; Ranucci, Matteo; Baryshnikova, Ekaterina

2014-01-01

Abstract During the coagulation process, blood changes from a liquid to a solid gel phase. These changes are reflected by changes in blood viscosity; however, blood viscosity at different shear rates (SR) has not been previously explored during the coagulation process. In this study, we investigated the viscosity changes of whole blood in 10 subjects with a normal coagulation profile, using a cone‐on‐plate viscosimeter. For each subject, three consecutive measurements were performed, at a SR of 20, 40, 80 sec−1. On the basis of the time‐dependent changes in blood viscosity, we identified the gel point (GP), the time‐to‐gel point (TGP), the maximum clot viscosity (MCV), and the clot lysis half‐time (CLH). The TGP significantly (P = 0.0023) shortened for increasing SR, and was significantly associated with the activated partial thromboplastin time at a SR of 20 sec−1 (P = 0.038) and 80 sec−1 (P = 0.019). The MCV was significantly lower at a SR of 80 sec−1 versus 40 sec−1 (P = 0.027) and the CLH significantly (P = 0.048) increased for increasing SR. These results demonstrate that measurement of blood viscosity during the coagulation process offers a number of potentially useful parameters. In particular, the association between the TGP and the activated partial thromboplastin time is an expression of the clotting time (intrinsic and common pathway), and its shortening for increasing SR may be interpreted the well‐known activating effects of SR on platelet activation and thrombin generation. Further studies focused on the TGP under conditions of hypo‐ or hypercoagulability are required to confirm its role in the clinical practice. PMID:24994896

Coagulation and electrocoagulation for co-treatment of stabilized landfill leachate and municipal wastewater

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Mohini Verma

2018-04-01

Full Text Available Landfill leachate and municipal wastewater at various ratios (1:20, 1:10, 1:7 and 1:5 were subjected to coagulation and electrocoagulation (EC. Alum was used in conventional coagulation at pH 6 and aluminum plate as electrode was used in EC at a current density of 386 A/m2 with 5 cm inter electrode spacing. Treatment efficiency was assessed from removal of chemical oxygen demand (COD, total suspended solids (TSS, turbidity, ammonia, nitrate and phosphate. At 1:5 ratio of landfill leachate to municipal wastewater, highest COD removal was with 3.8 g/L alum whereas highest turbidity removal was with 3.3 g/L alum during coagulation. EC exhibited almost similar removal efficiency for all the parameters at different ratios tested except for COD which was considerably higher at 1:20 ratio. Aluminum consumption from electrode was 0.7 g/L following EC as compared to 3.8 g/L alum used in coagulation. The amount of sludge produced was found to be higher with EC as compared to coagulation which could be due to the fact that the electrochemical method was performed for a longer duration than conventional coagulation. For minimal sludge generation, EC reaction time should be ∼30 min. Further studies with EC process on costing and sludge generation will help to advance the technology for wastewater treatment.

Radiofrequency Ablation Effectively Treated Focal Recurrence of Mesothelioma.

Science.gov (United States)

Nakamura, Akifumi; Takuwa, Teruhisa; Hashimoto, Masaki; Kondo, Nobuyuki; Takaki, Haruyuki; Fujiwara, Masayuki; Yamakado, Koichiro; Hasegawa, Seiki

2018-02-01

A 55-year-old man with malignant pleural mesothelioma underwent multimodality treatment comprising induction chemotherapy followed by extrapleural pneumonectomy and radiation therapy. After 2.5 years, focal recurrence occurred, with computed tomography revealing a tumor in the left cardiophrenic angle. Surgery was considered a problem for the patient because of the previous extrapleural pneumonectomy and difficult tumor location. Radiofrequency ablation was thus performed; the course was uneventful, and there was no recurrence. Radiofrequency ablation should be considered an option to treat recurrence of malignant pleural mesothelioma. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Endoscopic ultrasound-guided radiofrequency ablation of the pancreas

DEFF Research Database (Denmark)

Silviu, Ungureanu Bogdan; Daniel, Pirici; Claudiu, Mărgăritescu

2015-01-01

ultrasound (EUS)-guided radiofrequency ablation (RFA) probe through a 19G needle in order to achieve a desirable necrosis area in the pancreas. Radiofrequency ablation of the head of the pancreas was performed on 10 Yorkshire pigs with a weight between 25 kg and 35 kg and a length of 40-70 cm. Using an EUS...... analysis revealed increased values of amylase, alkaline phosphatase, and gamma-glutamyl transpeptidase on the 3rd day but a decrease on the 5th day. After necropsy and isolation of the pancreas, the ablated area was easily found, describing a solid necrosis. The pathological examination revealed...

Radiofrequency ablation for oral and maxillofacial pathologies: A description of the technique

Science.gov (United States)

Tandon, Rahul; Stevens, Timothy W.; Herford, Alan S.

2014-03-01

Introduction: Radiofrequency ablation (RFA) refers to a high-frequency current that heats and coagulates tissue. In the standard RFA setup, three components are used: a generator, an active electrode, and a dispersive electrode. RFA has garnered support in many of the surgical fields as an alternative to traditional procedures used in tumor removal. Other methods can prove to be more invasive and disfiguring to the patient, in addition to the unwarranted side effects; however, RFA provides a more localized treatment, resulting in decreased co-morbidity to the patient. Currently, its use in the field of oral and maxillofacial surgery is limited, as its technology has not reached our field. By describing its limited use to the optics community, we hope to expand its uses and provide patients with one more alternative treatment option. Methods and Uses: We will describe the use of RFA on three types of pathology: lymphangioma, rhabdomyoscarcoma, oral squamous cell carcinoma, and neoplastic osseous metastasis. The majority of treatments geared towards these pathologies involve surgical resection, followed by reconstruction. However, damage to vital structures coupled with esthetic disfigurement makes RFA a more valuable alternative. In many of the cases, the tumors were successfully removed without recurrence. Conclusion: While the use of RFA has been scarce in our field, we believe that with more exposure it can gain momentum as an alternative to current treatment options. However, there are improvements that we feel can be made, helping to maximize its effectiveness.

Treatment of sugar beet extraction juice stillage by natural coagulants extracted from common bean

OpenAIRE

Prodanović Jelena M.; Šćiban Marina B.; Antov Mirjana G.; Kukić Dragana V.; Vasić Vesna M.

2015-01-01

Distillery wastewaters have a great pollution potential, and pollution caused by them is one of the most critical environmental issues. This study is concerned with the coagulation efficiency of a new, environmental friendly, natural coagulant extracted from common bean seeds in the primary treatment of distillery wastewater in the bioethanol production from sugar beet juice. Active coagulation components were extracted from ground seeds of common bean with...

Numerical Simulation of the Coagulation Dynamics of Blood

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T. Bodnár

2008-01-01

Full Text Available The process of platelet activation and blood coagulation is quite complex and not yet completely understood. Recently, a phenomenological meaningful model of blood coagulation and clot formation in flowing blood that extends existing models to integrate biochemical, physiological and rheological factors, has been developed. The aim of this paper is to present results from a computational study of a simplified version of this coupled fluid-biochemistry model. A generalized Newtonian model with shear-thinning viscosity has been adopted to describe the flow of blood. To simulate the biochemical changes and transport of various enzymes, proteins and platelets involved in the coagulation process, a set of coupled advection–diffusion–reaction equations is used. Three-dimensional numerical simulations are carried out for the whole model in a straight vessel with circular cross-section, using a finite volume semi-discretization in space, on structured grids, and a multistage scheme for time integration. Clot formation and growth are investigated in the vicinity of an injured region of the vessel wall. These are preliminary results aimed at showing the validation of the model and of the numerical code.

Coagulation competence and fluid recruitment after moderate blood loss in young men

DEFF Research Database (Denmark)

Zaar, Morten; Mørkeberg, Jakob; Pott, Frank C

2014-01-01

The coagulation system is activated by a reduction of the central blood volume during orthostatic stress and lower body negative pressure suggesting that also a blood loss enhances coagulation. During bleeding, however, the central blood volume is supported by fluid recruitment to the circulation...

Split-face comparison of radiofrequency versus long-pulse Nd-YAG treatment of facial laxity.

Science.gov (United States)

Taylor, Mark B; Prokopenko, Inna

2006-04-01

To improve photoaging skin with laser treatment, multiple sessions have been considered necessary to achieve results comparable with one radiofrequency (RF) treatment. We compared single-treatment improvements obtained by the long-pulse 1064 nm Nd:YAG laser and RF device. In a split-face study, patients with sagging skin were treated once with laser (left side) and once with RF (right side) energy. Improvement judged by six blinded observers was greater for wrinkles and laxity (30% median) on the laser-treated side and essentially the same with both modalities (15% median) for texture, pores, and pigmentation. Improvement was maintained for at least 2-6 months on both facial sides without adverse effects. With a single treatment, both the long-pulse 1064 nm Nd:YAG laser and ThermaCool RF device provide a modest degree of improvement in both wrinkles and laxity of facial skin and similar improvement in texture, pores, and pigmentation.

Brownian coagulation at high particle concentrations

NARCIS (Netherlands)

Trzeciak, T.M.

2012-01-01

The process of Brownian coagulation, whereby particles are brought together by thermal motion and grow by collisions, is one of the most fundamental processes influencing the final properties of particulate matter in a variety of technically important systems. It is of importance in colloids,

Quantifying interspecific coagulation efficiency of phytoplankton

DEFF Research Database (Denmark)

Hansen, J.L.S.; Kiørboe, Thomas

1997-01-01

. nordenskjoeldii. Mutual coagulation between Skeletonema costatum and the non-sticky cel:ls of Ditylum brightwellii also proceeded with hall the efficiency of S. costatum alone. The latex beads were suitable to be used as 'standard particles' to quantify the ability of phytoplankton to prime aggregation...

47 CFR 2.1091 - Radiofrequency radiation exposure evaluation: mobile devices.

Science.gov (United States)

2010-10-01

... transmission of a signal. In general, maximum average power levels must be used to determine compliance. (3) If... workers that can be easily re-located, such as wireless devices associated with a personal computer, are... Satellite Communications Services, the General Wireless Communications Service, the Wireless Communications...

Performance Evaluation of the Sysmex CS-5100 Automated Coagulation Analyzer.

Science.gov (United States)

Chen, Liming; Chen, Yu

2015-01-01

Coagulation testing is widely applied clinically, and laboratories increasingly demand automated coagulation analyzers with short turn-around times and high-throughput. The purpose of this study was to evaluate the performance of the Sysmex CS-5100 automated coagulation analyzer for routine use in a clinical laboratory. The prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (Fbg), and D-dimer were compared between the Sysmex CS-5100 and Sysmex CA-7000 analyzers, and the imprecision, comparison, throughput, STAT function, and performance for abnormal samples were measured in each. The within-run and between-run coefficients of variation (CV) for the PT, APTT, INR, and D-dimer analyses showed excellent results both in the normal and pathologic ranges. The correlation coefficients between the Sysmex CS-5100 and Sysmex CA-7000 were highly correlated. The throughput of the Sysmex CS-5100 was faster than that of the Sysmex CA-7000. There was no interference at all by total bilirubin concentrations and triglyceride concentrations in the Sysmex CS-5100 analyzer. We demonstrated that the Sysmex CS-5100 performs with satisfactory imprecision and is well suited for coagulation analysis in laboratories processing large sample numbers and icteric and lipemic samples.

The Inflammatory Actions of Coagulant and Fibrinolytic Proteases in Disease

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Michael Schuliga

2015-01-01

Full Text Available Aside from their role in hemostasis, coagulant and fibrinolytic proteases are important mediators of inflammation in diseases such as asthma, atherosclerosis, rheumatoid arthritis, and cancer. The blood circulating zymogens of these proteases enter damaged tissue as a consequence of vascular leak or rupture to become activated and contribute to extravascular coagulation or fibrinolysis. The coagulants, factor Xa (FXa, factor VIIa (FVIIa, tissue factor, and thrombin, also evoke cell-mediated actions on structural cells (e.g., fibroblasts and smooth muscle cells or inflammatory cells (e.g., macrophages via the proteolytic activation of protease-activated receptors (PARs. Plasmin, the principle enzymatic mediator of fibrinolysis, also forms toll-like receptor-4 (TLR-4 activating fibrin degradation products (FDPs and can release latent-matrix bound growth factors such as transforming growth factor-β (TGF-β. Furthermore, the proteases that convert plasminogen into plasmin (e.g., urokinase plasminogen activator evoke plasmin-independent proinflammatory actions involving coreceptor activation. Selectively targeting the receptor-mediated actions of hemostatic proteases is a strategy that may be used to treat inflammatory disease without the bleeding complications of conventional anticoagulant therapies. The mechanisms by which proteases of the coagulant and fibrinolytic systems contribute to extravascular inflammation in disease will be considered in this review.

A parametric comparative study of electrocoagulation and coagulation using ultrafine quartz suspensions.

Science.gov (United States)

Kiliç, Mehtap Gülsün; Hoşten, Cetin; Demirci, Sahinde

2009-11-15

This paper attempts to compare electrocoagulation using aluminum anodes and stainless steel cathodes with conventional coagulation by aluminum sulfate dosing on aqueous suspensions of ultrafine quartz. Several key parameters affecting the efficiency of electrocoagulation and coagulation were investigated with laboratory scale experiments in search of optimal parameter values. Optimal values of the parameters were determined on the basis of the efficiency of turbidity removal from ultrafine quartz suspensions. The parameters investigated in the study were suspension pH, electrical potential, current density, electrocoagulation time, and aluminum dosage. A comparison between electrocoagulation and coagulation was made on the basis of total dissolved aluminum, revealing that electrocoagulation and coagulation were equally effective at the same aluminum dosage for the removal of quartz particles from suspensions. Coagulation, however, was more effective in a wider pH range (pH 6-9) than electrocoagulation which yielded optimum effectiveness in a relatively narrower pH range around 9, where, in both methods, these pH values corresponded to near-zero zeta potentials of quartz particles. Furthermore, experimental results confirmed that electrocoagulation could display some pH buffering capacity. The kinetics of electrocoagulation was very fast (<10 min) in approaching a residual turbidity, which could be modeled with a second-order rate equation.

Improvement of NOM Removal from Water Resources by Modifying the Coagulation Process

Directory of Open Access Journals (Sweden)

F Vaezi, A Mohagheghian, J Nouri, MR Eshraghian, A Ghasri

2005-01-01

Full Text Available As a result of the regulations on DBPs, interest in NOM removal is increasing and many water treatment plants in developed countries have started to measure the concentration of TOC in their finished waters. Promulgation of the rules will substantially increase these efforts in other countries too. Since the cost of TOC (and DBPs determination was high, it was decided to study the traditional analysis of COD as a surrogate measure to detect the organic constituents in raw water and the extent to which optimized coagulation with ferric chloride can increase COD removal. The two water samples studied belonged to Karaj and Jajrood Rivers. For both samples the observed values of COD removal by coagulation at lower pH (about 1-1.5 pH values less than the regular pH were about 85-95 percent without making water turbidity unacceptable. In order to determine the effects of organic content on coagulation, synthetic samples were also prepared with much higher COD values. Again, considerable increases in COD removal have been observed for most of these samples only by decreasing 0.5-2 pH value. The results indicated that a modified coagulation process without need to much increasing the amount of coagulant can be developed for these water samples.

Neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia.

Science.gov (United States)

Zhang, W C; Zhong, W X; Li, S T; Zheng, X S; Yang, M; Shi, J

2012-03-01

Although radiofrequency thermocoagulation is considered as a primary treatment for most patients with trigeminal neuralgia, neuronavigator-guided percutaneous radiofrequency thermocoagulation has been rarely reported. The object of this study was to assess the clinical value of neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia. The radiofrequency thermocoagulation was performed in 100 cases of trigeminal neuralgia. The patients were positioned supine or sitting, under Hartel's technique (reported by Sweet and Wepsic J Neurosurg 40:143-156, 1974), by anterior lateral facial approaches. The Gasserian ganglions were acupunctured, assisted by intraoperative CT scanning (3-digital reconstruction) and electrophysiology in order to accurately locate target. The needles located in oval foramen at the first puncture, the direction and position could be defined according to the electrophysiology examination. The pain alleviated immediately after operation. There occurred no serious complication and other nerve injury in all patients despite face numbness only. 3D-CT and electrophysiology Gasser's ganglion locations can raise the success rate of puncture, enhance the safety and reduce the incidence of complication, showing high academic value and its promising future.

Personal radiofrequency electromagnetic field exposure measurements in Swiss adolescents.

Science.gov (United States)

Roser, Katharina; Schoeni, Anna; Struchen, Benjamin; Zahner, Marco; Eeftens, Marloes; Fröhlich, Jürg; Röösli, Martin

2017-02-01

Adolescents belong to the heaviest users of wireless communication devices, but little is known about their personal exposure to radiofrequency electromagnetic fields (RF-EMF). The aim of this paper is to describe personal RF-EMF exposure of Swiss adolescents and evaluate exposure relevant factors. Furthermore, personal measurements were used to estimate average contributions of various sources to the total absorbed RF-EMF dose of the brain and the whole body. Personal exposure was measured using a portable RF-EMF measurement device (ExpoM-RF) measuring 13 frequency bands ranging from 470 to 3600MHz. The participants carried the device for three consecutive days and kept a time-activity diary. In total, 90 adolescents aged 13 to 17years participated in the study conducted between May 2013 and April 2014. In addition, personal measurement values were combined with dose calculations for the use of wireless communication devices to quantify the contribution of various RF-EMF sources to the daily RF-EMF dose of adolescents. Main contributors to the total personal RF-EMF measurements of 63.2μW/m 2 (0.15V/m) were exposures from mobile phones (67.2%) and from mobile phone base stations (19.8%). WLAN at school and at home had little impact on the personal measurements (WLAN accounted for 3.5% of total personal measurements). According to the dose calculations, exposure from environmental sources (broadcast transmitters, mobile phone base stations, cordless phone base stations, WLAN access points, and mobile phones in the surroundings) contributed on average 6.0% to the brain dose and 9.0% to the whole-body dose. RF-EMF exposure of adolescents is dominated by their own mobile phone use. Environmental sources such as mobile phone base stations play a minor role. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of electrocoagulation and chemical coagulation for heavy metal removal

Energy Technology Data Exchange (ETDEWEB)

Akbal, F.; Camci, S. [Ondokuz Mayis University, Engineering Faculty, Environmental Engineering Department, Kurupelit, Samsun (Turkey)

2010-10-15

Copper (Cu), chromium (Cr), and nickel (Ni) removal from metal plating wastewater by electrocoagulation and chemical coagulation was investigated. Chemical coagulation was performed using either aluminum sulfate or ferric chloride, whereas electrocoagulation was done in an electrolytic cell using aluminum or iron electrodes. By chemical coagulation, Cu-, Cr-, and Ni-removal of 99.9 % was achieved with aluminum sulfate and ferric chloride dosages of 500, 1000, and 2000 mg L{sup -1}, respectively. Removal of metals by electrocoagulation was affected by the electrode material, wastewater pH, current density, number of electrodes, and electrocoagulation time. Electrocoagulation with iron electrodes at a current density of 10 mA cm{sup -2}, electrocoagulation time of 20 min, and pH 3.0 resulted in 99.9 % Cu-, 99.9 % Cr-, and 98 % Ni-removal. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Laser, light, and energy devices for cellulite and lipodystrophy.

Science.gov (United States)

Peterson, Jennifer D; Goldman, Mitchel P

2011-07-01

Cellulite affects all races, and it is estimated that 85% of women older than 20 years have some degree of cellulite. Many currently accepted cellulite therapies target deficiencies in lymphatic drainage and microvascular circulation. Devices using radiofrequency, laser, and light-based energies, alone or in combination and coupled frequently with tissue manipulation, are available for improving cellulite. Laser assisted liposuction may improve cellulite appearance. Although improvement using these devices is temporary, it may last several months. Patients who want smoother skin with less visible cellulite can undergo a series of treatments and then return for additional treatments as necessary. Copyright © 2011 Elsevier Inc. All rights reserved.

Feasibility of Noninvasive Temperature Assessment During Radiofrequency Liver Ablation on Computed Tomography

NARCIS (Netherlands)

Pandeya, Ganga D.; Greuter, Marcel J. W.; de Jong, Koert P.; Schmidt, Bernhard; Flohr, Thomas; Oudkerk, Matthijs