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Sample records for clamp infrahepatic inferior

  1. Infrahepatic inferior caval and azygos vein formation in mammals with different degrees of mesonephric development.

    Science.gov (United States)

    Hikspoors, Jill P J M; Mekonen, Hayelom K; Mommen, Greet M C; Cornillie, Pieter; Köhler, S Eleonore; Lamers, Wouter H

    2016-03-01

    Controversies regarding the development of the mammalian infrahepatic inferior caval and azygos veins arise from using topography rather than developmental origin as criteria to define venous systems and centre on veins that surround the mesonephros. We compared caudal-vein development in man with that in rodents and pigs (rudimentary and extensive mesonephric development, respectively), and used Amira 3D reconstruction and Cinema 4D-remodelling software for visualisation. The caudal cardinal veins (CCVs) were the only contributors to the inferior caval (IVC) and azygos veins. Development was comparable if temporary vessels that drain the large porcine mesonephros were taken into account. The topography of the CCVs changed concomitant with expansion of adjacent organs (lungs, meso- and metanephroi). The iliac veins arose by gradual extension of the CCVs into the caudal body region. Irrespective of the degree of mesonephric development, the infrarenal part of the IVC developed from the right CCV and the renal part from vascular sprouts of the CCVs in the mesonephros that formed 'subcardinal' veins. The azygos venous system developed from the cranial remnants of the CCVs. Temporary venous collaterals in and around the thoracic sympathetic trunk were interpreted as 'footprints' of the dorsolateral-to-ventromedial change in the local course of the intersegmental and caudal cardinal veins relative to the sympathetic trunk. Interspecies differences in timing of the same events in IVC and azygos-vein development appear to allow for proper joining of conduits for caudal venous return, whereas local changes in topography appear to accommodate efficient venous perfusion. These findings demonstrate that new systems, such as the 'supracardinal' veins, are not necessary to account for changes in the course of the main venous conduits of the embryo. PMID:26659476

  2. Salvage with a Secondary Infrahepatic Cavocavostomy of the Occluded Modified Piggyback Anastomosis during Split Liver Transplantation: A Case Report

    Directory of Open Access Journals (Sweden)

    Erdem Kinaci

    2014-01-01

    Full Text Available Hepatic venous outflow obstruction following liver transplantation is rare but disastrous. Here we described a 14-year-old boy who underwent a split right lobe liver transplantation with modified (side-to-side piggyback technique which resulted in hepatic venous outflow obstruction. When the liver graft was lifted up, the outflow drainage returned to normal but when it was placed back into the abdomen, the outflow obstruction recurred. Because reanastomosis would have resulted in hepatic reischemia, alternatively, a second infrahepatic cavocavostomy was planned without requiring hepatic reischemia. During this procedure, the first assistant hung the liver up to provide sufficient outflow and the portal inflow of the graft continued as well. We only clamped the recipient’s infrahepatic vena cava and the caudal cuff of the graft cava. After the second end-to-side cavocaval anastomosis, the graft was placed in its orthotopic position and there was no outflow problem anymore. The patient tolerated the procedure well and there were no problems after three months of follow-up. A second cavocavostomy can provide an extra bypass for some hepatic venous outflow problems after piggyback anastomosis by avoiding hepatic reischemia.

  3. Salvage with a Secondary Infrahepatic Cavocavostomy of the Occluded Modified Piggyback Anastomosis during Split Liver Transplantation: A Case Report.

    Science.gov (United States)

    Kinaci, Erdem; Kayaalp, Cuneyt; Yilmaz, Sezai; Otan, Emrah

    2014-01-01

    Hepatic venous outflow obstruction following liver transplantation is rare but disastrous. Here we described a 14-year-old boy who underwent a split right lobe liver transplantation with modified (side-to-side) piggyback technique which resulted in hepatic venous outflow obstruction. When the liver graft was lifted up, the outflow drainage returned to normal but when it was placed back into the abdomen, the outflow obstruction recurred. Because reanastomosis would have resulted in hepatic reischemia, alternatively, a second infrahepatic cavocavostomy was planned without requiring hepatic reischemia. During this procedure, the first assistant hung the liver up to provide sufficient outflow and the portal inflow of the graft continued as well. We only clamped the recipient's infrahepatic vena cava and the caudal cuff of the graft cava. After the second end-to-side cavocaval anastomosis, the graft was placed in its orthotopic position and there was no outflow problem anymore. The patient tolerated the procedure well and there were no problems after three months of follow-up. A second cavocavostomy can provide an extra bypass for some hepatic venous outflow problems after piggyback anastomosis by avoiding hepatic reischemia. PMID:24959369

  4. To clamp or not to clamp late?

    Directory of Open Access Journals (Sweden)

    Nicoletta Iacovidou

    2013-04-01

    Full Text Available When resuscitating a neonate, one encounters controversial issues and a great deal of confusion. These issues include the question as to when should the umbilical cord be clamped. Clamping and cutting the umbilical cord at birth is the oldest intervention in humans. Even though many aspects of the timing for cord clamping have been clarified, some questions still remain unanswered. If delayed cord clamping is to become a standard approach which timing is the optimal? And depending on the mode of delivery should timing be the same or different for normal vaginal delivery or for caesarean section? What about  the compromised neonate, or the very preterm one? We have more questions than answers. More randomized controlled studies are needed in normal and pathologic neonates, in order to address these questions, before we practice delayed cord clamping with safety for the babies and the mothers.

  5. Servodrive Clamping Unit

    OpenAIRE

    Štefánek, Tomáš

    2009-01-01

    Design servodrive clamping unit with pneumatic or mechanic multiplier. Unit has be instrumental to strength clamp parts in tension technical machines. Frame unit’s is complicate from massive and movable clamping board and is self-supporting. Unit has be solution like incorporated modulus. Target is proposal main driving period for movable clamping board. Work up proposal constructional solution, drawing listings, production drawing of the three engaged part of, BOM. Computational report must ...

  6. Traumatismos de veia cava inferior Inferior vena cava injuries

    Directory of Open Access Journals (Sweden)

    Cleinaldo de Almeida Costa

    2005-10-01

    Full Text Available OBJETIVO: Avaliar a incidência, o perfil clínico e as estratégias operatórias dos ferimentos de Veia Cava Inferior (VCI. MÉTODOS: Foram analisados retrospectivamente os prontuários de 76 doentes com ferimento de VCI atendidos nos dois prontossocorros de Manaus, no período de janeiro de 1997 a julho de 2002. Mecanismo de lesão, mortalidade, estado hemodinâmico, índice de trauma abdominal penetrante (PATI, achados intra-operatórios e conduta cirúrgica foram estudados. RESULTADOS: Quarenta e nove (65% doentes sofreram lesão por arma branca, 26 (34% por arma de fogo e um por traumatismo abdominal fechado. Quarenta e um (54% doentes sobreviveram. Quase todos chegaram acordados, entretanto 40% estavam hipotensos (pressão arterial sistólica BACKGROUND: Injuries of inferior vena cava (IVC require immediate and definitive action. Our objective is to evaluate the incidence, the clinical findings and the operative approach to IVC injuries. METHODS: We retrospectively studied 76 patients with IVC injuries treated in two Emergency Hospitals of Manaus, AM, Brazil, from January 1997 to July 2002. Mechanisms of injuries, mortality, hemodynamic status, penetrating abdominal trauma index (PATI, intraoperative findings and surgical approach were among assessed data. RESULTS: Fourty-nine patients (65% had stab wounds, 26 (34% gunshot wounds, and one had blunt abdominal trauma. Fourty-one (54% patients survived. Almost all patients entered the emergency room awake, although 40% were hypotensive (systolic blood pressure < 70 mmHg, and the penetrating abdominal trauma index average was above 40. At laparotomy, active retroperitoneal bleeding or an expanding retroperitoneal hematoma were detected in all cases. Caval injury was retro-hepatic in 21 patients, and infrahepatic in the other 55. The prevailing surgical approach was lateral repair in 65 patients. Atrial-caval shunting was tried in six patients, with only three survivals. CONCLUSIONS: We

  7. Photovoltaic panel clamp

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  8. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  9. The intestinal tract as the major source of interleukin 6 production during abdominal aortic clamping and hind limb ischaemia-reperfusion injury O trato intestinal como a principal fonte na producao de interleucina 6 durante clampeamento da aorta abdominal e lesão de isquemia/rererfusão de membros inferiores

    Directory of Open Access Journals (Sweden)

    Márcio Benedito Palma Pimenta

    2007-01-01

    Full Text Available PURPOSE: The aim of this study was to investigate whether the hind limbs or intestinal tract is the most important initiator of the inflammatory response secondary aortic clamping and hind limb ischemia/reperfusion injury. METHODS: Blood samples of Wistar rats obtained from posterior cava vein, portal vein, and heart cavity during either laparotomy (control group, n=8 or laparotomy + 2 h of aortic clamping and bilateral hind limb ischemia (ischemia group, n=8, or 2 h after ischemia and 2 h of reperfusion (ischemia-reperfusion group, n=8 were assayed for interleukin 6 (IL-6 and C-reactive protein (CRP. RESULTS: Serum IL-6 at the heart (223.6±197.9 [10-832] pg/mL was higher (pOBJETIVO: Investigar qual o principal mediador da resposta inflamatória na lesao de isquemia/reperfusão após clampeamento da aorta abdominal e isquemia dos membros inferiores: o intestine ou as extremidades inferiores. MÉTODOS: amostra de sangue de ratos Wistar coletados da cava posterior, porta e cavidade cardíaca during tanto laparotomia (grupo controle n=8 ou laparotomia + 2 horas de clampeamento aórtico e isquemia bilateral de membros posteriores (grupo isquemia n=8, ou 2 h de isquemia seguido por 2 horas de reperfusão (grupo isquemia/reperfusão n=8, onde foram dosados interleucina 6 e proteína C-reativa. RESULTADOS: Il-6 no coração (223.6±197.9 [10-832] pg/mL foi maior (p<0.001 tanto na veia porta (133.08±108.52 [4-372] pg/mL quanto na veia cava posterior (127.58±109.15 [8-388] pg/mL. PCR não foi significativamente diferente entre os grupos. CONCLUSÃO: o trato intestinal foi responsável pela resposta inflamatória secundária a lesão de isquemia/reperfusão.

  10. Laser beam guard clamps

    Science.gov (United States)

    Dickson, Richard K.

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  11. Clamping characteristics study on different types of clamping unit

    International Nuclear Information System (INIS)

    Plastic products are becoming more and more widely used in aerospace, IT, digital electronics and many other fields. With the development of technology, the requirement of product precision is getting higher and higher. However, type and working performance of clamping unit play a decisive role in product precision. Clamping characteristics of different types of clamping unit are discussed in this article, which use finite element numerical analysis method through the software ABAQUS to study the clamping uniformity, and detect the clamping force repeatability precision. The result shows that compared with toggled three-platen clamping unit, clamping characteristics of internal circulation two-platen clamping unit are better, for instance, its mold cavity deformation and force that bars and mold parting surface suffered are more uniform, and its clamping uniformity and repeatability precision is also better

  12. Neuronal Response Clamp

    Directory of Open Access Journals (Sweden)

    Avner Wallach

    2011-04-01

    Full Text Available Responses of individual neurons to ongoing input are highly variable, reflecting complex threshold dynamics. Experimental access to this threshold dynamics is required in order to fully characterize neuronal input-output relationships. The challenge is practically intractable using present day experimental paradigms due to the cumulative, nonlinear interactions involved. Here we introduce the Neuronal Response Clamp, a closed-loop technique enabling control over the instantaneous response probability of the neuron. The potential of the technique is demonstrated by showing direct access to threshold dynamics of cortical neuron in-vitro using extracellular recording and stimulation, over timescales ranging from seconds to many hours. Moreover, the method allowed us to expose the sensitivity of threshold dynamics to spontaneous input from the network in which the neuron is embedded. The Response Clamp technique follows the rationale of the voltage-clamp and dynamic-clamp approaches, extending it to the neuron's spiking behavior. The general framework offered here is applicable in the study of other neural systems, beyond the single neuron level.

  13. Cantilever clamp fitting

    Science.gov (United States)

    Melton, Patrick B. (Inventor)

    1989-01-01

    A device is disclosed for sealing and clamping a cylindrical element which is to be attached to an object such as a wall, a pressurized vessel or another cylindrical element. The device includes a gland having an inner cylindrical wall, which is threaded at one end and is attached at a bendable end to a deformable portion, which in turn is attached to one end of a conical cantilever structure. The other end of the cantilever structure connects at a bendable area to one end of an outer cylindrical wall. The opposite end of cylindrical wall terminates in a thickened portion, the radially outer surface of which is adapted to accommodate a tool for rotating the gland. The terminal end of cylindrical wall also includes an abutment surface, which is adapted to engage a seal, which in turn engages a surface of a receiver. The receiver further includes a threaded portion for engagement with the threaded portion of gland whereby a tightening rotation of gland relative to receiver will cause relative movement between cylindrical walls and of gland. This movement causes a rotation of the conical structure and thus a bending action at bending area and at the bending end of the upper end of inner cylindrical wall. These rotational and bending actions result in a forcing of the deformable portion radially inwardly so as to contact and deform a pipe. This forcible contact creates a seal between gland and pipe, and simultaneously clamps the pipe in position.

  14. PKM Mechatronic Clamping Adaptive Device

    OpenAIRE

    Alberto Borboni; Francesco Aggogeri; Angelo Merlo; Nicola Pellegrini; Cinzia Amici

    2015-01-01

    This study proposes a novel adaptive fixturing device based on active clamping systems for smart micropositioning of thin-walled precision parts. The modular architecture and the structure flexibility make the system suitable for various industrial applications. The proposed device is realized as a Parallel Kinematic Machine (PKM), opportunely sensorized and controlled, able to perform automatic error-free workpiece clamping procedures, drastically reducing the overall fixturing set-up time. ...

  15. Temperature compensating stiff pipe clamp

    International Nuclear Information System (INIS)

    A new type of non-integral pipe attachment for nuclear piping seismic restraint that allows the pipe free thermal diametric expansion without constraint when using dissimilar pipe and clamp material is described. The clamp has a high spring rate that can be controlled by variable stiffness parameters in the design. Described in detail are thermal constraint stress, load stress distribution, spring rates, load angles and design philosophy. Analytical methods of code design, fabrication techniques, cost benefits and lead time reduction techniques are presented. 5 refs

  16. Clamp wins pipe repair prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

  17. Analysis list: Clamp [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Clamp Cell line + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Cla...mp.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Clamp.Cell_line.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cell_line.gml ...

  18. Dynamics of Open DNA Sliding Clamps.

    Directory of Open Access Journals (Sweden)

    Aaron J Oakley

    Full Text Available A range of enzymes in DNA replication and repair bind to DNA-clamps: torus-shaped proteins that encircle double-stranded DNA and act as mobile tethers. Clamps from viruses (such as gp45 from the T4 bacteriophage and eukaryotes (PCNAs are homotrimers, each protomer containing two repeats of the DNA-clamp motif, while bacterial clamps (pol III β are homodimers, each protomer containing three DNA-clamp motifs. Clamps need to be flexible enough to allow opening and loading onto primed DNA by clamp loader complexes. Equilibrium and steered molecular dynamics simulations have been used to study DNA-clamp conformation in open and closed forms. The E. coli and PCNA clamps appear to prefer closed, planar conformations. Remarkably, gp45 appears to prefer an open right-handed spiral conformation in solution, in agreement with previously reported biophysical data. The structural preferences of DNA clamps in solution have implications for understanding the duty cycle of clamp-loaders.

  19. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

  20. How Does Patch Clamp Work?--An easy approach to understanding patch clamp mechanism

    Institute of Scientific and Technical Information of China (English)

    关兵才; 李之望

    2003-01-01

    In order to help patch clamp users,most of whom are not good enough at electrics and electronics,to understandthe complicated principles of patch clamp technique,we present a readily accessible explanation of patch clamp mechanism,in-cluding basic analysis of membrane currents under voltage clamp,achievement of voltage clamp and current recording,capaci-tance compensation,series resistance compensation,voltage offset correction,leak subtraction and current clamp,based on ourworking and teaching experience and with the aid of some useful formulae.

  1. Protein folding in a force clamp

    Science.gov (United States)

    Cieplak, Marek; Szymczak, P.

    2006-05-01

    Kinetics of folding of a protein held in a force clamp are compared to an unconstrained folding. The comparison is made within a simple topology-based dynamical model of ubiquitin. We demonstrate that the experimentally observed variations in the end-to-end distance reflect microscopic events during folding. However, the folding scenarios in and out of the force clamp are distinct.

  2. Primary inferior oblique overaction-management by inferior oblique recession.

    Directory of Open Access Journals (Sweden)

    Kamlesh

    2002-01-01

    Full Text Available PURPOSE: To evaluate the effect of 10 mm inferior oblique recession in horizontal strabismus with V pattern and primary inferior oblique overaction. METHODS: Ten patients of V esotropia and exotropia with primary inferior oblique overaction underwent 10 mm inferior oblique recession by the methods described by Park and Stallard. Pre- and postoperative V pattern, inferior oblique overaction and binocularity were assessed. Patients were followed up for 3 months. RESULTS: The mean preoperative V pattern was 38.3 PD and the mean inferior oblique overaction was 22 PD. After surgery the mean correction of the V pattern was 26.9 PD and the mean residual V pattern was 11.4 PD. None of the patients had inferior oblique overaction postoperatively. 70% of the patients showed improvement in binocularity. CONCLUSION: 10 mm Inferior oblique recession by the described technique is a simple, safe and effective method for the cosmetic and functional treatment of horizontal deviation and V pattern with primary inferior oblique overaction.

  3. Luxatio erecta: Inferior glenohumeral dislocation

    OpenAIRE

    Baba Asif; Bhat Javid; Paljor S; Mir Naseer; Majid Suhail

    2007-01-01

    Inferior dislocation of the shoulder, also called luxatio erecta, is a rare form of the otherwise common shoulder dislocation. It accounts for less than 0.5% of all shoulder dislocations. A case involving the inferior dislocation of the shoulder is reported. A brief review of the presentation and management of the condition is described.

  4. Luxatio erecta: Inferior glenohumeral dislocation

    Directory of Open Access Journals (Sweden)

    Baba Asif

    2007-01-01

    Full Text Available Inferior dislocation of the shoulder, also called luxatio erecta, is a rare form of the otherwise common shoulder dislocation. It accounts for less than 0.5% of all shoulder dislocations. A case involving the inferior dislocation of the shoulder is reported. A brief review of the presentation and management of the condition is described.

  5. Dynamic clamp with StdpC software

    Science.gov (United States)

    2011-01-01

    Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based on a fast cycle of measuring the membrane potential of a cell, calculating the current of a desired simulated component using an appropriate model and injecting this current into the cell. Here, we present a dynamic clamp protocol using free, fully integrated, open-source software (StdpC, Spike timing dependent plasticity Clamp). Use of this protocol does not require specialist hardware, costly commercial software, experience in real time operating systems or a strong programming background. The software enables the configuration and operation of a wide range of complex and fully automated dynamic clamp experiments via an intuitive and powerful interface with a minimal initial lead-time of a few hours. After initial configuration, experimental results can be generated within minutes of cell impalement. PMID:21372819

  6. Inequalities for the Vibrating Clamped Plate Problem

    OpenAIRE

    MCHALE, K.P.

    2001-01-01

    We study the eigenvalues of the vibrating clamped plate problem. We have made improvements on the bounds of the ratios of the eigenvalues of the biharmonic operator (clamped plate) using the methods of Payne, Polya, and Weinberger. The difference in our proof lies mainly with the trial functions and the orthogonality arguments. While Payne, Polya, and Weinberger and Hile and Yeh project away components along u1,u2,...,uk to meet the orthogonality conditions,we use a translation/rotation ...

  7. Protein folding in a force-clamp

    Science.gov (United States)

    Cieplak, Marek; Szymczak, Piotr

    2006-03-01

    Kinetics of folding of a protein held in a force-clamp are compared to an unconstrained folding. The comparison is made within a simple topology-based dynamical model of ubiquitin. We demonstrate that the experimentally observed rapid changes in the end-to-end distance mirror microscopic events during folding. However, the folding scenarios in and out of the force-clamp are distinct.

  8. Protein folding in a force-clamp

    OpenAIRE

    Cieplak, Marek; Szymczak, Piotr

    2006-01-01

    Kinetics of folding of a protein held in a force-clamp are compared to an unconstrained folding. The comparison is made within a simple topology-based dynamical model of ubiquitin. We demonstrate that the experimentally observed variations in the end-to-end distance reflect microscopic events during folding. However, the folding scenarios in and out of the force-clamp are distinct.

  9. Moral Equality and Natural Inferiority

    OpenAIRE

    Thomas, Laurence

    2004-01-01

    This essay is a commentary upon "Race and Kant" by Thomas Hill, Jr and Bernard Boxill. They argue that although Kant in his anthropological writings took blacks to be inferior, his moral theory requires that they be shown the proper moral respect since blacks are persons nonetheless. I argue that this argument is sound, because the conception of inferiority that Kant attributed to blacks does not permit showing them the proper moral respect. Imagine a defective Mercedes Benz and a Ford...

  10. Piezoresistive cantilever force-clamp system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Goodman, Miriam B. [Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305 (United States)

    2011-04-15

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  11. An Ultrasonic Clamp for Bloodless Partial Nephrectomy

    Science.gov (United States)

    Lafon, Cyril; Bouchoux, Guillaume; Murat, François Joseph; Birer, Alain; Theillère, Yves; Chapelon, Jean Yves; Cathignol, Dominique

    2007-05-01

    Maximum conservation of the kidney is preferable through partial nephrectomy for patients at risk of disease recurrence of renal cancers. Haemostatic tools are needed in order to achieve bloodless surgery and reduce post surgery morbidity. Two piezo-ceramic transducers operating at a frequency of 4 MHz were mounted on each arm of a clamp. When used for coagulation purposes, two transducers situated on opposite arms of the clamp were driven simultaneously. Heat delivery was optimized as each transducers mirrored back to targeted tissues the wave generated by the opposite transducer. Real-time treatment monitoring with an echo-based technique was also envisaged with this clamp. Therapy was periodically interrupted so one transducer could generate a pulse. The echo returning from the opposite transducer was treated. Coagulation necroses were obtained in vitro on substantial thicknesses (23-38mm) of pig liver over exposure durations ranging from 30s to 130s, and with acoustic intensities of less than 15W/cm2 per transducer. Both kidneys of two pigs were treated in vivo with the clamp (14.5W/cm2 for 90s), and the partial nephrectomies performed proved to be bloodless. In vitro and in vivo, wide transfixing lesions corresponded to an echo energy decrease superior to -10dB and parabolic form of the time of flight versus treatment time. In conclusion, this ultrasound clamp has proven to be an excellent mean for achieving monitored haemostasis in kidney.

  12. IMPORTANT: Fluke is recalling Digital Clamp Meters

    CERN Multimedia

    2013-01-01

    Fluke is voluntarily recalling four models of Digital Clamp Meters: Fluke 373, 374, 375 and 376. If you own one of these clamp meters, please stop using it and send it back to Fluke for repair even if you have not experienced problems.   Description of the problem: "The printed circuit assembly may not be properly fastened to the test lead input jack. This may result in inaccurate voltage readings, including a low or no-voltage reading on a circuit energised with a hazardous voltage, presenting a shock, electrocution or thermal burn hazard." To determine if your clamp meter is affected by this recall notice, and for more information, click here.

  13. Design and application of multifunctional stomach clamp

    Institute of Scientific and Technical Information of China (English)

    Yun Fu Lu; Pi Wu Li; Xir Xin Zhang

    2000-01-01

    AIM Pylorus and pyloric vagus preserving gastrectomy (PPVPG) is an efficient operation mode for treatinggastric and duodenal ulcers. For its better application and popularization, we have designed andmanufactured a special multifunctional stomach clamp.METHODS The clamp has been designed carefully in view of the different sizes of the patients' stomachsand the different starting points of Latarjer nerves so as to facilitate the execution of the present operationmode, which requires the preservation of the vagus innervated pyloric region so as to make the remnantstomach maintain its normal physiological function and the vagus branches clinging antral seromuscular flapkept in proper size so that avoiding too much remaining antral mucosa is removed to cause greater difficultyin operation. With this in view, we observed and measured the distance between the Latarjer nerves distribution and the pyloric rings of 42 patients' stomachs in the course of operations. We bent an aluminumstring 3 mm thick for each stomach according to the size of antral seromuecular flap and chose an optimalcurvature from the 42 sizes for manufacturing the clamp. The clamp is made of 3 Cr13 stainless steel,consisting of three parts, the curved head, the fastening ring and the handle. The curved head is shapedalmost exactly like the remained antral seromuscular flap. The ring at its tip when in place fastens the twosides of the clamp so that the tissue of the stomach between will be clutched by an even force. On one sideare three cuts for moving the ring upwards, each cut representing 1 mm for fastening and adjustments can bemade in view of the thickness or thinness of the tissue. The handles bend backward for fighting shy of thecuts so as to facilitate the operation.RESULTS With the stomach disassociated in the light of PPVPG procedures, the clamp may easily beapplied from the upper part of the Latarjer nerves. The following merits can be noted. ① The curving line ofthe flap can be precisely

  14. Prolonged penile strangulation with metal clamps

    Institute of Scientific and Technical Information of China (English)

    Chirag Patel; Richard Kim; Michael Delterzo; Run Wang

    2006-01-01

    Various different objects have been reported to strangulate the penis. We reported on a patient who used metal radiator clamps for an extended period of time. Workup included history, physical examination and urinalysis. The patient was taken to the operating room for further evaluation with cystourethroscopy and orthopedic wire cutters were used to break the metal bands.

  15. Multilevel-clamped multilevel converters (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago; Busquets-Monge, Sergio; Blaabjerg, Frede

    2012-01-01

    This letter introduces a new series of multilevel (ML) converters based on the ML clamping concept. By applying this technique, a ML clamping unit (MCU) conveys additional levels for synthesizing the output waveforms of a diode-clampedML dc– ac power converter. The basic building block of the ML ...

  16. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress and...... better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

  17. π-Clamp-mediated cysteine conjugation

    Science.gov (United States)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  18. Hyperinsulinemic Euglycemic clamp for cardiac PET

    International Nuclear Information System (INIS)

    The aim of this study was to assess the adequacy of Hyperinsulinemic Euglycaemic clamp to yield technically adequate and clinically meaningful cardiac scans. The F- 18 Fluorodeoxyglucose scans obtained in diabetic patients are of sub-optimal quality as high level of glucose competes with radioactive Fluorodeoxyglucose for cardiac uptake. Thus to allow quick stabilization of metabolic environment and to get superior quality images, insulin clamp is an accepted technique. Thirty patients (20 males and 5 females) with ages ranging from 43 to 69 years, who were referred for post-myocardial infarction estimation of myocardial viability, were evaluated in this study. All patients reported for the test after 6 hours of fasting. At first myocardial perfusion studies were carried out in all patients with Tc-99m Tetrofosmin on a GE dual head gamma camera. Blood glucose levels were checked. The blood sugar levels in the patients were in the range of 130 - 190 mg%. Insulin clamp was applied depending upon the glucose level obtained, according to ASNC guidelines for PET Myocardial Glucose Metabolism and Perfusion Imaging. On stabilization of blood glucose levels, 10 mCi of F-18 FDG was injected and imaging was performed at 1 hour on a dedicated 16 slice STE GE PET -- CT scanner. Three patients had incidence of hypoglycemia as a side effect during the procedure, their blood sugar falling to 40 mg%. They were treated with 25ml of 25% dextrose intravenously following which there was stabilization of blood sugar. Entire procedure including Tetrofosmin imaging took approximately 4-6 hours. Good quality images were obtained after the use of insulin clamp. Infusion of insulin and glucose gives stable plasma glucose levels during imaging. The insulin clamp technique makes it possible to adjust and maintain a metabolic steady state during the PET study. It does not alter F-18 FDG uptake patterns in different myocardial areas and gives superior quality images. The technique is safe and

  19. Simulation of the Inferior Mirage

    Science.gov (United States)

    Branca, Mario

    2010-01-01

    A mirage can occur when a continuous variation in the refractive index of the air causes light rays to follow a curved path. As a result, the image we see is displaced from the location of the object. If the image appears higher in the air than the object, it is called a "superior" mirage, while if it appears lower it is called an "inferior"…

  20. Condition of chromic acid anodized aluminum clamps flown

    Science.gov (United States)

    Plagemann, W. L.

    1991-01-01

    A survey of the condition of the chromic acid anodized (CAA) coating on selected LDEF tray clamps was carried out. Measurements of solar absorptance and thermal emittance were carried out at multiple locations on both the space exposed and spacecraft facing sides of the clamps. Multiple clamps from each available angle relative to the ram direction were examined. The diffuse component of the reflectance spectrum was measured for a selected subset of the clamps. The thickness of the CAA was determined for a small set of clamps. Examples of variation in integrity of the coatings from leading to trailing edge will be shown.

  1. Biological cell controllable patch-clamp microchip

    Science.gov (United States)

    Penmetsa, Siva; Nagrajan, Krithika; Gong, Zhongcheng; Mills, David; Que, Long

    2010-12-01

    A patch-clamp (PC) microchip with cell sorting and positioning functions is reported, which can avoid drawbacks of random cell selection or positioning for a PC microchip. The cell sorting and positioning are enabled by air bubble (AB) actuators. AB actuators are pneumatic actuators, in which air pressure is generated by microheaters within sealed microchambers. The sorting, positioning, and capturing of 3T3 cells by this type of microchip have been demonstrated. Using human breast cancer cells MDA-MB-231 as the model, experiments have been demonstrated by this microchip as a label-free technical platform for real-time monitoring of the cell viability.

  2. Inferior mirages: an improved model.

    Science.gov (United States)

    Young, Andrew T

    2015-02-01

    A quantitative model of the inferior mirage is presented, based on a realistic temperature profile in the convective boundary layer, using Monin-Obukhov similarity theory. The top of the inverted image is determined by the logarithmic part of the profile; the bottom is the apparent horizon, which depends on optical obstruction by roughness elements. These effects of surface roughness are included in the model, which is illustrated with a simulation. The vertical magnification varies throughout the mirage, becoming infinite at Minnaert's ill-named "vanishing line"-which makes green flashes apparent to the naked eye. PMID:25967823

  3. Design of a hot clamp for small diameter LMFBR piping

    International Nuclear Information System (INIS)

    In order to evaluate the feasibility of using a strap-type clamp on breeder reactor small diameter piping, a series of analyses were conducted to determine the thermal and mechanical stresses induced in the pipe by the clamp. The effect of using a thin layer of insulation of varying thickness between the pipe and clamp was also investigated. A thermal analysis of the pipe and clamp was conducted for each thermal transient rate. Various insulation values ranging from metal-to-metal condition to perfect insulation between the pipe and clamp were analyzed to determine the effect of insulating the pipe from the clamp. An axisymmetric finite element model was used to determine the axial thermal and stress patterns

  4. Inferior epigastric artery angiography applied in the transplantation with the deep inferior epigastric perforator free flap

    International Nuclear Information System (INIS)

    Objective: To observe the effect of inferior epigastric artery angiography applied in the transplantation with the deep inferior epigastric perforator free flap. Methods: Seven patients who had undergone the deep inferior epigastric perforator free flap transplantation, received angiography of the inferior epigastric artery. The value of the angiography was discussed. Results: All patients were successful in angiography without any adverse reaction. All patients were successful in transplantation except one because of personal reason. Conclusion: Inferior epigastric artery angiography facilitates the transplantation with the deep inferior epigastric perforator free flap. (authors)

  5. Combination Space Station Handrail Clamp and Pointing Device

    Science.gov (United States)

    Hughes, Stephen J. (Inventor)

    1999-01-01

    A device for attaching an experiment carrier to a space station handrail is provided. The device has two major components, a clamping mechanism for attachment to a space station handrail, and a pointing carrier on which an experiment package can be mounted and oriented. The handrail clamp uses an overcenter mechanism and the carrier mechanism uses an adjustable preload ball and socket for carrier positioning. The handrail clamp uses a stack of disk springs to provide a spring loaded button. This configuration provides consistent clamping force over a range of possible handrail thicknesses. Three load points are incorporated in the clamping mechanism thereby spreading the clamping load onto three separate points on the handrail. A four bar linkage is used to provide for a single actuation lever for all three load points. For additional safety, a secondary lock consisting of a capture plate and push lock keeps the clamp attached to the handrail in the event of main clamp failure. For the carrier positioning mechanism, a ball in a spring loaded socket uses friction to provide locking torque; however. the ball and socket are torque limited so that the ball ran slip under kick loads (125 pounds or greater). A lead screw attached to disk spring stacks is used to provide an adjustable spring force on the socket. A locking knob is attached to the lead screw to allow for hand manipulation of the lead screw.

  6. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path...

  7. Analysis of Contact Characteristic of Overhead Line and Suspension Clamp

    Directory of Open Access Journals (Sweden)

    Zhao Xinze

    2013-01-01

    Full Text Available In this paper, a LGJ150/25 type ACSR transmission line and a CGU-3 type suspension clamp are taken as research objects. A contact model of the conductor and the clamp was established by using finite element method. The effects of sag angle of the conductor, holding force and tension force in section are analyzed. The results showed that the contact area in the middle of the clamp is of belt-like type. The extreme values of tress were observed on the edge of the contact area and near the edge of keeper. In clamp section, suspension angle had the greatest influence on contact stress, and then the clamp force. The tension force in section played a most important role in these affecting factors. In the exit section of clamp, the biggest impact factor was tension force in this section, then the suspension angle, the third was clamp force. The results provide theoretical basis on reducing corona loss, optimization the clamp. Doubtlessly, the conclusion has important theoretical significance and application value.

  8. 21 CFR 876.5160 - Urological clamp for males.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for...

  9. Applications of alcohol clamping in early drug development

    NARCIS (Netherlands)

    Zoethout, Remco Wiebe Martijn

    2012-01-01

    This thesis describes the development of a novel alcohol clamp, a new method to obtain stable plasma levels of alcohol and its application in CNS-research. The method might have several advantages that were explored in subsequent studies described in this thesis. The stability of the alcohol clamp w

  10. Breast Reconstruction: Deep Inferior Epigastric Perforator

    Medline Plus

    Full Text Available ... surgery each of them chose to undergo. The deep inferior epigastric perforator flap technique allows surgeons to rebuild breasts in the ... areolar-sparing mastectomy and immediate reconstruction using the deep inferior epigastric perforator flap, or the DIEP flap. I'm pleased to ...

  11. Responses from two firing patterns in inferior colliculus neurons to stimulation of the lateral lemniscus dorsal nucleus.

    Science.gov (United States)

    Li, Xiao-Ting; Wang, Ning-Yu; Wang, Yan-Jun; Xu, Zhi-Qing; Liu, Jin-Feng; Bai, Yun-Fei; Dai, Jin-Sheng; Zhao, Jing-Yi

    2016-05-01

    The γ-aminobutyric acid neurons (GABAergic neurons) in the inferior colliculus are classified into various patterns based on their intrinsic electrical properties to a constant current injection. Although this classification is associated with physiological function, the exact role for neurons with various firing patterns in acoustic processing remains poorly understood. In the present study, we analyzed characteristics of inferior colliculus neurons in vitro, and recorded responses to stimulation of the dorsal nucleus of the lateral lemniscus using the whole-cell patch clamp technique. Seven inferior colliculus neurons were tested and were classified into two firing patterns: sustained-regular (n = 4) and sustained-adapting firing patterns (n = 3). The majority of inferior colliculus neurons exhibited slight changes in response to stimulation and bicuculline. The responses of one neuron with a sustained-adapting firing pattern were suppressed after stimulation, but recovered to normal levels following application of the γ-aminobutyric acid receptor antagonist. One neuron with a sustained-regular pattern showed suppressed stimulation responses, which were not affected by bicuculline. Results suggest that GABAergic neurons in the inferior colliculus exhibit sustained-regular or sustained-adapting firing patterns. Additionally, GABAergic projections from the dorsal nucleus of the lateral lemniscus to the inferior colliculus are associated with sound localization. The different neuronal responses of various firing patterns suggest a role in sound localization. A better understanding of these mechanisms and functions will provide better clinical treatment paradigms for hearing deficiencies. PMID:27335563

  12. Tuberculosis pulmonar de campos inferiores

    Directory of Open Access Journals (Sweden)

    Alejandra González

    2010-10-01

    Full Text Available La tuberculosis (TB que compromete sólo los campos pulmonares inferiores (TBCI es poco frecuente en el adulto y en general está asociada a alguna causa de inmunodepresión. El objetivo de nuestro trabajo fue determinar la incidencia de TBCI en nuestra población y comparar sus características respecto de la TB pulmonar de localización habitual. Se estudiaron en forma retrospectiva en el período de 2004 a 2008, 42 pacientes con TBCI que fueron comparados con 84 pacientes con TB pulmonar de localización habitual (grupo control. Se excluyeron pacientes con HIV. La TBCI representó el 6% del total de TB pulmonar. No se encontraron diferencias significativas en cuanto a edad, sexo, presencia de cavidades en la radiografía, días de evolución y nivel de albúmina. La TBCI tuvo significativamente mayor proporción de comorbilidades (p < 0.001, presencia de condensación (p < 0.001 y compromiso unilateral (p < 0.001 en la radiografía de tórax, junto con mayor número de internaciones (p = 0.02. Cabe destacar que sólo16 de los 42 pacientes con TBCI (38% tenían alguna comorbilidad demostrada. La TBCI puede presentarse aun sin comorbilidades asociadas y debe sospecharse en neumonías de evolución tórpida independientemente de su localización.

  13. Dynamic clamp: a powerful tool in cardiac electrophysiology.

    Science.gov (United States)

    Wilders, Ronald

    2006-10-15

    Dynamic clamp is a collection of closely related techniques that have been employed in cardiac electrophysiology to provide direct answers to numerous research questions regarding basic cellular mechanisms of action potential formation, action potential transfer and action potential synchronization in health and disease. Building on traditional current clamp, dynamic clamp was initially used to create virtual gap junctions between isolated myocytes. More recent applications include the embedding of a real pacemaking myocyte in a simulated network of atrial or ventricular cells and the insertion of virtual ion channels, either simulated in real time or simultaneously recorded from an expression system, into the membrane of an isolated myocyte. These applications have proven that dynamic clamp, which is characterized by the real-time evaluation and injection of simulated membrane current, is a powerful tool in cardiac electrophysiology. Here, each of the three different experimental configurations used in cardiac electrophysiology is reviewed. Also, directions are given for the implementation of dynamic clamp in the cardiac electrophysiology laboratory. With the growing interest in the application of dynamic clamp in cardiac electrophysiology, it is anticipated that dynamic clamp will also prove to be a powerful tool in basic research on biological pacemakers and in identification of specific ion channels as targets for drug development. PMID:16873403

  14. POLYCYTHEMIA RISK IN NEONATES WITH DELAYED CORD CLAMPING

    OpenAIRE

    I Gusti Agung Ayu Sri Wulandari Pramana; Ketut Putera Kemara; I Wayan Megadhana

    2013-01-01

    Delayed Cord Clamping is still a controversial issue in the world of medicine. Until recently, the perfect times to do a Delayed Cord Clamping in various parts of the Earth in the world are still very diverse. There are a few things that became a major concern associated with Delayed Cord Clamping, one of which is the increase in blood volume due to an increase in the number of erythrocytes which led to occurrence of neonatal polycythemia which later can lead to various complications. Polycy...

  15. Breast Reconstruction: Deep Inferior Epigastric Perforator

    Medline Plus

    Full Text Available ... DEEP INFERIOR EPIGASTRIC PROCEDURE BETH ISRAEL MEDICAL CENTER NEW YORK, NY January 11, 2008 00:00:24 ... hour, live from Beth Israel Medical Center in New York City, you'll hear about the tough ...

  16. Breast Reconstruction: Deep Inferior Epigastric Perforator

    Medline Plus

    Full Text Available ... usually in that setting, we'll proceed as planned with the deep inferior epigastric perforator technique. 00: ... revision of the reconstruction. So it's almost a planned two-stage process. We like to do as ...

  17. Breast Reconstruction: Deep Inferior Epigastric Perforator

    Medline Plus

    Full Text Available BREAST RECONSTRUCTION: DEEP INFERIOR EPIGASTRIC PROCEDURE BETH ISRAEL MEDICAL CENTER NEW YORK, NY January 11, 2008 00:00:24 WOMAN 1: The diagnosis of breast cancer is shocking for anybody and ...

  18. Planar patch-clamp force microscopy on living cells

    Energy Technology Data Exchange (ETDEWEB)

    Pamir, Evren [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany); George, Michael; Fertig, Niels [Nanion Technologies GmbH, Erzgiessereistr. 4, 80335 Munich (Germany); Benoit, Martin [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany)], E-mail: martin.benoit@physik.uni-muenchen.de

    2008-05-15

    Here we report a new combination of the patch-clamp technique with the atomic force microscope (AFM). A planar patch-clamp chip microstructured from borosilicate glass was used as a support for mechanical probing of living cells. The setup not only allows for immobilizing even a non-adherent cell for measurements of its mechanical properties, but also for simultaneously measuring the electrophysiological properties of a single cell. As a proof of principle experiment we measured the voltage-induced membrane movement of HEK293 and Jurkat cells in the whole-cell voltage clamp configuration. The results of these measurements are in good agreement with previous studies. By using the planar patch-clamp chip for immobilization, the AFM not only can image non-adhering cells, but also gets easily access to an electrophysiologically controlled cellular probe at low vibrational noise.

  19. Insulin Tolerance Test and Hyperinsulinemic-Euglycemic Clamp

    Science.gov (United States)

    Paschos, Georgios K.; FitzGerald, Garret A.

    2016-01-01

    The two tests are used to evaluate in vivo sensitivity to insulin in mouse. The hypoerinsulinemic-euglycemic clamp provides information about the sensitivity to insulin in liver and other metabolically relevant tissues.

  20. An incidental finding of the accessory inferior thyroid artery

    OpenAIRE

    Sedy J

    2008-01-01

    We report a case of an incidental finding of the right accessory inferior thyroid artery, emerging from the thyrocervical trunk together with a typical inferior thyroid artery, present in a normal position. On the left side, only single inferior thyroid artery was present. Only one inferior thyroid vein was found on each side. The accessory inferior thyroid artery entered the thyroid gland approximately 1 cm above the normal inferior thyroid, above the superior parathyroid gland. Although acc...

  1. Usefulness of Kelly clamp crushing technique during hepatic resection

    OpenAIRE

    Kim, K. H.; Lee, S G

    2008-01-01

    Introduction. Recently, there are various kinds of parenchymal transection methods. The aim of this study is to evaluate the usefulness of the Kelly clamp crushing technique compared to ultrasonic dissector during hepatic resection. Materials and methods. Comparisons between 10 ultrasonic dissector group and 10 Kelly clamp crushing technique group were performed by using nine items (transaction time, right lobe volume, perioperative transfusion, total bilirubin (TB), aspartate aminotransferas...

  2. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Graeme R Polglase

    Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  3. Lateralization Technique and Inferior Alveolar Nerve Transposition

    Science.gov (United States)

    Sanches, Marco Antonio; Ramalho, Gabriel Cardoso; Manzi, Marcello Roberto

    2016-01-01

    Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics. PMID:27433360

  4. Anatomy of Inferior Mesenteric Artery in Fetuses.

    Science.gov (United States)

    Nuzhat, Ayesha

    2016-01-01

    Aim. To analyze Inferior Mesenteric Artery in fetuses through its site of origin, length, diameter, and variation of its branches. Method. 100 fetuses were collected from various hospitals in Warangal at Kakatiya Medical College in Andhra Pradesh, India, and were divided into two groups, group I (second-trimester fetuses) and group II (third-trimester fetuses), followed by dissection. Result. (1) Site of Origin. In group I fetuses, origin of Inferior Mesenteric Artery was at third lumbar vertebra in 33 out of 34 fetuses (97.2%). In one fetus it was at first lumbar vertebra, 2.8%. In all group II fetuses, origin of Inferior Mesenteric Artery was at third lumbar vertebra. (2) Length. In group I fetuses it ranged between 18 and 30 mm, average being 24 mm except in one fetus where it was 48 mm. In group II fetuses the length ranged from 30 to 34 mm, average being 32 mm. (3) Diameter. In group I fetuses it ranged from 0.5 to 1 mm, and in group II fetuses it ranged from 1 to 2 mm, average being 1.5 mm. (4) Branches. Out of 34 fetuses of group I, 4 fetuses showed variation. In one fetus left colic artery was arising from abdominal aorta, 2.9%. In 3 fetuses, Inferior Mesenteric Artery was giving a branch to left kidney, 8.8%. Out of 66 fetuses in group II, 64 had normal branching. In one fetus left renal artery was arising from Inferior Mesenteric Artery, 1.5%, and in another fetus one accessory renal artery was arising from Inferior Mesenteric Artery and entering the lower pole of left kidney. Conclusion. Formation, course, and branching pattern of an artery depend on development and origin of organs to attain the actual adult position. PMID:27313956

  5. Anatomy of Inferior Mesenteric Artery in Fetuses

    Directory of Open Access Journals (Sweden)

    Ayesha Nuzhat

    2016-01-01

    Full Text Available Aim. To analyze Inferior Mesenteric Artery in fetuses through its site of origin, length, diameter, and variation of its branches. Method. 100 fetuses were collected from various hospitals in Warangal at Kakatiya Medical College in Andhra Pradesh, India, and were divided into two groups, group I (second-trimester fetuses and group II (third-trimester fetuses, followed by dissection. Result. (1 Site of Origin. In group I fetuses, origin of Inferior Mesenteric Artery was at third lumbar vertebra in 33 out of 34 fetuses (97.2%. In one fetus it was at first lumbar vertebra, 2.8%. In all group II fetuses, origin of Inferior Mesenteric Artery was at third lumbar vertebra. (2 Length. In group I fetuses it ranged between 18 and 30 mm, average being 24 mm except in one fetus where it was 48 mm. In group II fetuses the length ranged from 30 to 34 mm, average being 32 mm. (3 Diameter. In group I fetuses it ranged from 0.5 to 1 mm, and in group II fetuses it ranged from 1 to 2 mm, average being 1.5 mm. (4 Branches. Out of 34 fetuses of group I, 4 fetuses showed variation. In one fetus left colic artery was arising from abdominal aorta, 2.9%. In 3 fetuses, Inferior Mesenteric Artery was giving a branch to left kidney, 8.8%. Out of 66 fetuses in group II, 64 had normal branching. In one fetus left renal artery was arising from Inferior Mesenteric Artery, 1.5%, and in another fetus one accessory renal artery was arising from Inferior Mesenteric Artery and entering the lower pole of left kidney. Conclusion. Formation, course, and branching pattern of an artery depend on development and origin of organs to attain the actual adult position.

  6. A NOVEL SINGLE IMPEDANCE NETWORK BASED NEUTRAL POINT CLAMPED SEVEN LEVEL THREE PHASE INVETER WITH REDUCED CLAMPING DIODES FOR REGENERATIVE APPLICATIONS

    OpenAIRE

    T. A. Raghavendiran; C.L.Kuppuswamy

    2012-01-01

    A Multilevel Inverter (MLI) can eliminate the need for the step-up transformer and reduce the harmonics produced by the inverter. This paper presents Neutral Point Clamped (NPC) seven level inverter with less number of clamping diodes which is suitable for regenerative loads such as three phase induction motor with regenerative braking. To reduce the stress across the main switches, diodes are clamped anti-parallel to the main switches. In Earlier configurations, the numbers of clamping diode...

  7. [Pedicular clamping in major hepatectomies: clamping "of principle" or "of necessity"? A comparative study].

    Science.gov (United States)

    Le Treut, Y P; Christophe, M; Banti, J C; Berthet, B; Bricot, R

    1995-02-01

    Fifty-two consecutive patients undergoing major hepatic resection for liver tumor were divided into two groups according to the operative procedure. Group A consisted of 34 patients in whom vascular inflow occlusion was performed "de principle" during parenchymal division and intrahepatic approach of the portal structures; the mean duration of the portal triad clamping was 43 mn (ranged 17 to 70 mn). Group B patients (18 cases) had hilar division of the structures of that portion of the liver due to be removed, prior to parenchymal division was performed without vascular arrest, except in five "de necessitate" cases during 5 to 22 mn. Groups A and B were comparable in terms of patient age or status, of king of liver tumors and extent of resection. Mean operating duration (215 vs 263 mn), volume of intraoperative blood transfusion (557 vs 1019 ml), intensive care (2.5 vs 4.2 days) and total hospital stays (19.6 vs 30.5 days) were significantly reduced in group A. A higher but transient increase of amino-transferase level was the only biochemical consequence of liver ischemia in group A, whereas postoperative disturbance in serum bilirubin, prothrombin time, fibrinogen, and total protein were significantly greater in group B, probably because of the greater volume of blood transfusion in this group. Thus, routine vascular inflow occlusion with transhepatic approach of the portal structures may be an effective and innocuous procedure for major liver resection. PMID:7751341

  8. Improved DNA clamps by stacking to adjacent nucleobases

    DEFF Research Database (Denmark)

    Fatthalla, M.I.; Pedersen, Erik Bjerregaard

    2012-01-01

    Three or four aromatic rings interconnected by acetylene bridges form a stiff conjugated system with sufficient conformational freedom to make it useful to link together the two strands of a DNA clamp. Upon targeting a ssDNA, the conformational flexibility allows better stacking of the linker to...... the underlying non-planar base triplet in the formed triplex. This type of triplexes has a substantially higher thermal melting temperature which can be further improved by inserting locked nucleic acids (LNAs) in the Hoogsteen part of the clamp. An extremely high sensitivity to mismatches is observed...

  9. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  10. New active load voltage clamp for HF-link converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, M.A.E.

    2005-07-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path during malfunctions of the secondary bidirectional bridge. The feasibility of the approach is shown on audio power amplifier prototype. New integrated magnetics design is presented that incorporates both the main power and auxiliary transformer on the same magnetic core. (au)

  11. The problem of isotropic rectangular plate with four clamped edges

    Indian Academy of Sciences (India)

    C Erdem İmrak; Ismail Gerdemeli

    2007-06-01

    The examination of the exact solution of the governing equation of the rectangular plate is important for many reasons. This report discusses in exact solution of the governing equation of an isotropic rectangular plate with four clamped edges. A numerical method for clamped isotropic rectangular plate under distributed loads and an exact solution of the governing equation in terms of trigonometric and hyperbolic function are given. Finally, an illustrative example is given and the results are compared with those reported earlier. This method is found to be easier and effective. The results show reasonable agreement with other available results, but with a simpler and practical approach.

  12. Breast Reconstruction: Deep Inferior Epigastric Perforator

    Medline Plus

    Full Text Available ... tough decisions these and other women made after learning they had breast cancer. You will also see the breast reconstruction surgery each of them chose to undergo. The deep inferior epigastric perforator flap technique allows surgeons to rebuild breasts in the most ...

  13. Inferior vena cava aneurysm. A case report

    International Nuclear Information System (INIS)

    Aneurysmal dilatation of the inferior vena cava can occur in patients with heart disease or, very likely, with congenital weakness of the vascular wall. Chest x-ray discloses a mass in right cardiophrenic angle. The diagnosis can be confirmed by ultrasound, more invasive measures being unnecessary. (Author) 6 refs

  14. A case of inferior lumbar hernia

    OpenAIRE

    Vidhyasagar M. Sharma; Sushil D. Akruwala; Shashank Desai; Dave, Rajendra I.

    2013-01-01

    In this article we report a case of inferior lumbar hernia. The patient underwent preperitoneal meshplasty. The patient is well on follow up with no recurrence. The relevant literature has been reviewed and management discussed in brief. [Int J Res Med Sci 2013; 1(1.000): 33-35

  15. A case of inferior lumbar hernia

    Directory of Open Access Journals (Sweden)

    Vidhyasagar M. Sharma

    2013-02-01

    Full Text Available In this article we report a case of inferior lumbar hernia. The patient underwent preperitoneal meshplasty. The patient is well on follow up with no recurrence. The relevant literature has been reviewed and management discussed in brief. [Int J Res Med Sci 2013; 1(1.000: 33-35

  16. Breast Reconstruction: Deep Inferior Epigastric Perforator

    Medline Plus

    Full Text Available ... that the lower blood supply, which is the deep inferior epigastric artery and vein, comes up from underneath the muscle ... the vein but there isn't an adequate artery, so usually in that setting, we'll proceed as planned ... perforator technique. 00:18:40 WILLIAM SAMSON, MD: ...

  17. COMPARISON OF VIBRATION PERFORMANCE OF A SANDWICH CLAMPED-CLAMPED BEAM WITH MAGNETS VERSUS CONVENTIONAL CONSTRAINED DAMPING TREATMENTS

    Institute of Scientific and Technical Information of China (English)

    ZhengHuiming; HeZeng; LiMing; ZhaoGaoyu

    2004-01-01

    This paper investigates how the magnetic constrained layer damping (MCLD) treatment suppresses the displacement and acceleration resonant peak of a clamped-clamped beam. Because MCLI) treatment reduces input work and gives more dissipation energy, the vibration from external excitation can be effectively suppressed.The vibration reduction effects of MCLD and other conventional constrained damping treatments are also evaluated. In many cases, using MCLD treatments can yield smaller displacement and acceleration resonant peak especially in mode 1 compared to the other treatments without greatly changing the natural frequencies of the base beam.

  18. Mechanical stability of multidomain proteins and novel mechanical clamps.

    Science.gov (United States)

    Sikora, Mateusz; Cieplak, Marek

    2011-06-01

    We estimate the size of mechanostability for 318 multidomain proteins which are single-chain and contain up to 1021 amino acids. We predict existence of novel types of mechanical clamps in which interdomain contacts play an essential role. Mechanical clamps are structural regions which are the primary source of a protein's resistance to pulling. Among these clamps there is one that opposes tensile stress due to two domains swinging apart. This movement strains and then ruptures the contacts that hold the two domains together. Another clamp also involves tensile stress but it originates from an immobilization of a structural region by a surrounding knot-loop (without involving any disulfide bonds). Still another mechanism involves shear between helical regions belonging to two domains. We also consider the amyloid-prone cystatin C which provides an example of a two-chain 3D domain-swapped protein. We predict that this protein should withstand remarkably large stress, perhaps of order 800 pN, when inducing a shearing strain. The survey is generated through molecular dynamics simulations performed within a structure-based coarse grained model. PMID:21465555

  19. Hyperinsulinemic Euglycemic Clamp for cardiac PET: An Initial Experience

    International Nuclear Information System (INIS)

    Full text: Aim: To study the adequacy of hyperinsulinemic euglycemic clamp to yield technically adequate and clinically meaningful cardiac scans in diabetic patients. 18 F- FDG scans are of suboptimal quality as high level of glucose competes with flurodeoxyglucose for cardiac uptake. Thus to allow quick stabilization of metabolic environment and to get superior quality images, insulin clamp is an accepted technique. Methods: 8 patients (7 males and 1 female) of ages ranging from 43 to 69 years were evaluated in this ongoing study, referred for estimation of myocardial viability post myocardial infarction. All patients were required 6 hours fasting. Initially they were injected with 20 milicurie of Technetium Tetrofosmin and myocardial perfusion imaging done 1 hour later on GE dual head gamma camera. Blood glucose levels were checked. Their blood sugars were in the range of 130mg% - 170mg%. Insulin clamp was applied depending upon the glucose level obtained, according to ASNC guidelines for PET Myocardial Glucose Metabolism and Perfusion Imaging. On stabilization of blood glucose levels, 10 milicurie of 18 F- FDG was injected. Imaging was done 1 hour later on Dedicated 16 slice STE PET CT scanner. There was no incidence of hypoglycemia or any other side effects during the procedure. Entire procedure including tetrofosmin imaging took approximately 4 hours. Results: Good quality images were obtained after the use of insulin clamp. Conclusion: Infusion of insulin and glucose gives stable plasma glucose and serum insulin levels during imaging. The insulin clamp technique makes it possible to adjust and maintain a metabolic steady state during PET study. It does not alter 18F-FDG uptake patterns in different myocardial areas. It permits the use of smaller FDG doses for the patient and gives superior quality images. The technique is safe and should improve both the clinical use and cost effectiveness of FDG-PET imaging for identification of injured but viable myocardium

  20. Vibration control of a flexible clamped-clamped plate based on an improved FULMS algorithm and laser displacement measurement

    Science.gov (United States)

    Xie, Lingbo; Qiu, Zhi-cheng; Zhang, Xian-min

    2016-06-01

    This paper presents a novel active resonant vibration control experiment of a flexible clamped-clamped plate using an improved filtered-U least mean square (FULMS) algorithm and laser displacement measurement. Different from the widely used PZT sensors or acceleration transducers, the vibration of the flexible clamped-clamped plate is measured by a non-contact laser displacement measurement sensor with higher measurement accuracy and without additional load to the plate. The conventional FULMS algorithm often uses fixed step size and needs reference signal related to the external disturbance signal. However, the fixed step size method cannot obtain a fast convergence speed and it will result in a low residual error. Thus, a variable step size method is investigated. In addition, it is difficult to extract reference signal related to the vibration source directly in the practical application. Therefore, it is practically useful that a reference signal is constructed by both the controller parameters and the vibration residual signal. The experimental results demonstrate that the improved FULMS algorithm has better vibration control effect than the proportional derivative (PD) feedback control algorithm and the fixed step-size control algorithm.

  1. CT appearance of pneumatized inferior turbinate

    International Nuclear Information System (INIS)

    Aim: To study the computed tomography (CT) features of pneumatized inferior turbinate (PIT). Materials and methods: A retrospective review of paranasal sinus CT over a period of 12 years showed 16 cases of PIT. The pneumatization pattern was analysed according to the classification proposed by Bolger. Pneumatization was classified into three types: bulbous, lamellar, and extensive. Results: Fourteen patients had unilateral and two patients had bilateral pneumatization (n = 18). Seven (39%) of the 18 PIT were bulbous, nine (50%) were lamellar, and two (11%) were of the extensive type. In eight (44%) cases there was communication between the medial wall of the maxillary sinus and the PIT. Conclusions: The features of PIT can be readily identified on CT. Imaging helps clinicians to differentiate PIT from other causes of the inferior turbinate hypertrophy or complications

  2. Rare Inferior Shoulder Dislocation (Luxatio Erecta)

    OpenAIRE

    Hakan Cift; Salih Soylemez; Murat Demiroglu; Korhan Ozkan; Vahit Emre Ozden; Ozkut, Afsar T.

    2015-01-01

    Although shoulder dislocations have been seen very frequently, inferior dislocation of shoulder constitutes only 0.5% of all shoulder dislocations. We share our 4 patients with luxatio erecta and present their last clinical control. 2 male and 2 female Caucasian patients were diagnosed as luxatio erecta. Patients’ ages were 78, 62, 65, and 76. All patients’ reduction was done by traction-abduction and contour traction maneuver in the operating room. The patients had no symptoms and no limitat...

  3. Does Wal-Mart Sell Inferior Goods?

    OpenAIRE

    Emek Basker

    2008-01-01

    I estimate the aggregate income elasticity of Wal-Mart's and Target's revenues using quarterly data for 1997-2006. I find that Wal-Mart's revenues increase during bad times, whereas Target's revenues decrease, consistent with Wal-Mart selling "inferior goods" in the technical sense of the term. An upper bound on the aggregate income elasticity of demand for Wal-Mart's wares is -0.5.

  4. Four- year thyroidectomy procedures: Ligasure Vs. clamp & tie

    Directory of Open Access Journals (Sweden)

    Pazoki AR

    2010-01-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The electrothermal bipolar vessel sealing system is an adjunct to the hemostatic technique, which has been successfully used in many abdominal operation, recently made available to thyroid surgery. The purpose of this was compare the outcomes of new hemostatic technique with traditional method of clamp and tie."n"nMethods: In this retrospective cross-sectional study has been done in surgery's wards of Milad & Rasul- Akram hospitals in Tehran, Iran. During three- year period between 2005-2008 all patients with different kind of pathology that need operation were assessed. Time duration of surgery and hospital stay and post surgery complication in two group, ligasure (n=45 and clamp & tie (n=145 were compared with each others."n"nResults: No difference was seen between two groups in time duration of surgery. Significant difference was seen in hospital stay and complications of surgery. Time of operation in Ligasure group was 132/22 minute and in clamp and tie group was 130/10 minute. There was found significant difference in duration of hospital stay and postoperative complication. Hypocalcemia were seen in two and 24 cases in Ligasure and Clamp & Tie group, respectively (p<0.05. Hospital stay was 2

  5. Review: The lord of the rings: Structure and mechanism of the sliding clamp loader.

    Science.gov (United States)

    Kelch, Brian A

    2016-08-01

    Sliding clamps are ring-shaped polymerase processivity factors that act as master regulators of cellular replication by coordinating multiple functions on DNA to ensure faithful transmission of genetic and epigenetic information. Dedicated AAA+ ATPase machines called clamp loaders actively place clamps on DNA, thereby governing clamp function by controlling when and where clamps are used. Clamp loaders are also important model systems for understanding the basic principles of AAA+ mechanism and function. After nearly 30 years of study, the ATP-dependent mechanism of opening and loading of clamps is now becoming clear. Here I review the structural and mechanistic aspects of the clamp loading process, as well as comment on questions that will be addressed by future studies. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 532-546, 2016. PMID:26918303

  6. Design of Voltage-clamp-controlled Current-clamp%电压钳控制电流钳的设计

    Institute of Scientific and Technical Information of China (English)

    熊俊; 樊枫; 瞿安连

    2008-01-01

    研究证明,传统膜片钳放大器在电流钳模式下记录到的快速电压信号会存在失真,且造成失真的根本原因是由于膜片钳的探头电路设计.为了克服这些缺陷重新设计了一种探头,新探头电路不仅能像传统的电压跟随器一样测量瞬态电压,而且适用于传统的电压钳工作模式.此外,一种命名为电压钳控制的电流钳技术被应用来改进传统的膜片钳放大器.用可变的低通滤波器来调整电压钳模块的响应速度,从而在实现膜电位钳位的同时准确记录快速电压信号.桥平衡电路用来消除命令电流流过串联电阻时带来的电压误差.而传统膜片钳中的快电容补偿环节则被改进用来补偿电极分布电容和探头放大器输入电容并提高电流钳模式下系统的响应速度.细胞模型实验结果表明,改进后的膜片钳放大器能够满足电生理研究中快速电位变化测量的需要.%Previous research rcvealed that distortion is detected in transient voltage signal recorded with traditional patch clamp amplifier under current clamp mode, which is essentially resulted by electronic design of the headstage of the patch clamp. A new kind of headstage is designed to modify the defect, the circuit of which not only measures the transient potentials as the classical voltage follower does but also is quite suitable for the standard voltage-clamp mode. Furthermore, the technique of voltage-clamp-controlled current-clamp is applied for modifying the conventional patch-clamp amplifier, the variable low-pass filter is added into the circuit to reduce the response speed of voltage-clamp module, thus the transient potentials changes can be measured while membrane potential is kept at a constant value. Bridge balance circuitry is designed to eliminate the voltage drop while the variable current injected into the electrode. And fast capacitance compensation stage of conventional PCA is modified to nentralize the

  7. Gigaseal formation in patch clamping with applications of nanotechnology

    CERN Document Server

    Malboubi, Majid

    2014-01-01

    This book presents an investigation of gigaseal formation using micro/nanotechnology. The aims of the book are twofold. First, it explains the mechanisms of gigaseal formation using the latest discoveries. Second, it provides practical techniques for frequent formation of high resistance seals. The formation of a high-resistance electrical seal, also known as a gigaseal, between a cell membrane and a glass micropipette tip is essential in patch-clamp experiments. Even though four decades have passed since the introduction of the patch-clamping technique by Neher and Sakmann, gigaseal formation remains an obstacle in developing the high-throughput ion channel screening systems required by the pharmaceutical industry. Here the authors share their latest methods for achieving gigaseal formation and describe techniques that are highly desirable at both research and industrial levels. Nanotechnology has been found to be a powerful tool for studying and modifying glass micropipettes and in tackling the problem of g...

  8. A new configuration for multilevel converters with diode clamped topology

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ledwich, G.; Ghosh, A.; Blaabjerg, Frede

    points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless of......Due to the increased use of renewable energy and power elctronic applications, more multilevel converters (MLC) are developed. A Neutral Point Clamped (NPC) inverter is one of the most used multilevel topologies for wind turbine (WT) and photovoltaic (PV) applications. One of the most crucial...... load changes which can avoid neutral point balancing problem in such converters. In addition, the presented topology is suitable for renewable energy systems to boost the low rectified output-voltage. In order to verify the proposed topology, steady state analysis, modelling and simulations are carried...

  9. The early effects of delayed cord clamping in term infants born to Libyan mothers

    NARCIS (Netherlands)

    Emhamed, Musbah Omar; van Rheenen, Patrick; Brabin, Bernard J

    2004-01-01

    This study was conducted to evaluate the haematological effects of the timing of umbilical cord clamping in term infants 24 h after birth in Libya. Mother-infant pairs were randomly assigned to early cord clamping (within 10s after delivery) or delayed clamping (after the cord stopped pulsating). Ma

  10. Gamma radiation methods for clamp-on multiphase flow metering

    OpenAIRE

    Blaney, S

    2008-01-01

    The development of a cost-effective multiphase flow meter to determine the individual phase flow rates of oil, water and gas was investigated through the exploitation of a single clamp-on gamma densitometer and signal processing techniques. A fast-sampling (250 Hz) gamma densitometer was installed at the top of the 10.5 m high, 108.2 mm internal diameter, stainless steel catenary riser in the Cranfield University multiphase flow test facility. Gamma radiation attenuation data w...

  11. Analysis of Control Strategies for Diode Clamped Multilevel Inverter

    OpenAIRE

    C. R. Balamurugan; S. P. NATARAJAN; R. Revathy

    2013-01-01

    This paper presents the comparison of various Pulse Width Modulation (PWM) strategies for the three phase Diode Clamped Multi Level Inverter (DCMLI). The main contribution of this paper is the proposal of new modulation schemes with Variable Amplitude (VA) and various new schemes adopting the constant switching frequency and also variable switching frequency multicarrier control freedom degree combination concepts are developed and simulated for the chosen three phase DCMLI. The three phase D...

  12. Stretching of proteins in a force-clamp

    OpenAIRE

    Szymczak, Piotr; Cieplak, Marek

    2005-01-01

    Mechanically induced protein unfolding in the force-clamp apparatus is shown, in a coarse-grained model of ubiquitin, to have lognormal statistics above a treshold force and exponential below it. Correspondingly, the mean unfolding time is slowly varying and exponentially decreases as a function of the force. The time dependencies of the end-to-end distances are also distinct. The time sequence of unfolding events weakly depends on force and much of it resembles that for stretching at constan...

  13. The human dynamic clamp as a paradigm for social interaction

    OpenAIRE

    Dumas, Guillaume; de Guzman, Gonzalo C.; Tognoli, Emmanuelle; Kelso, J. A. Scott

    2014-01-01

    The human dynamic clamp (HDC) is proposed as a general paradigm for studies of elementary forms of social behavior in complex biological systems. HDC enables parametric control of real-time bidirectional interaction between humans and empirically grounded theoretical models of coordination dynamics. It thus provides necessary experimental access for laboratory investigations, while preserving the reciprocity and open boundary conditions inherent in daily life social interactions. As proof of ...

  14. POLYCYTHEMIA RISK IN NEONATES WITH DELAYED CORD CLAMPING

    Directory of Open Access Journals (Sweden)

    I Gusti Agung Ayu Sri Wulandari Pramana

    2013-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Delayed Cord Clamping is still a controversial issue in the world of medicine. Until recently, the perfect times to do a Delayed Cord Clamping in various parts of the Earth in the world are still very diverse. There are a few things that became a major concern associated with Delayed Cord Clamping, one of which is the increase in blood volume due to an increase in the number of erythrocytes which led to occurrence of neonatal polycythemia which later can lead to various complications. Polycythemia in neonates is a situation where the value of venous blood hematokrit over 65% (0.65 or the amount of hemoglobin more than 22gr/Dl. However, to date the data from a variety of the latest research and analysis of the studies mention that the polycythemia that occurs in neonates with umbilical cord pinching the flush delay was mild polycythemia that can improve after 48 to 72 hours after the baby is born.

  15. Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

    KAUST Repository

    Masri, Karim M.

    2014-08-17

    We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

  16. Inferior Gluteal Perforator Flaps for Breast Reconstruction

    OpenAIRE

    Allen, Robert J.; LoTempio, Maria M.; Granzow, Jay W.

    2006-01-01

    Perforator flaps represent the latest in the evolution of soft tissue flaps. They allow the transfer of the patient's own skin and fat in a reliable manner with minimal donor-site morbidity. The powerful perforator flap concept allows transfer of tissue from numerous, well-described donor sites to almost any distant site with suitable recipient vessels. The inferior gluteal artery perforator (I-GAP) flap is one option that allows a large volume of tissue to be used for breast reconstruction w...

  17. Iatrogenic injury to the inferior alveolar nerve

    DEFF Research Database (Denmark)

    Hillerup, Søren

    2008-01-01

    The purpose of this prospective, non-randomised, descriptive study is to characterise the neurosensory deficit and associated neurogenic discomfort in 52 patients with iatrogenic injury to the inferior alveolar nerve (IAN). All patients were examined and followed up according to a protocol...... injuries associated with third molar surgery, other dento-alveolar surgery or implant surgery occur sufficiently often to render prevention a key issue....... assessing tactile, thermal, and positional perception as well as two-point discrimination and pain. In 48 patients with IAN injuries of differing etiologies who did not undergo surgery, 32 patients with injury associated with third molar surgery exhibited significant spontaneous improvement of sensory...

  18. M. tuberculosis Sliding β-Clamp Does Not Interact Directly with the NAD+ -Dependent DNA Ligase

    OpenAIRE

    Vandna Kukshal; Taran Khanam; Deepti Chopra; Nidhi Singh; Sabyasachi Sanyal; Ravishankar Ramachandran

    2012-01-01

    The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp) to 3.0 Å resolution. The protein crystallized in the space group C222(1) with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains...

  19. Analysis of dynamic properties of boring bars concerning different clamping conditions

    Science.gov (United States)

    Åkesson, Henrik; Smirnova, Tatiana; Håkansson, Lars

    2009-11-01

    Boring bars are frequently used in the manufacturing industry to turn deep cavities in workpieces and are usually associated with vibration problems. This paper focuses on the clamping properties' influence on the dynamic properties of clamped boring bars. A standard clamping housing of the variety commonly used in industry today has been used. Both a standard boring bar and a modified boring bar have been considered. Two methods have been used: Euler-Bernoulli beam modeling and experimental modal analysis. It is demonstrated that the number of clamping screws, the clamping screw diameter sizes, the screw tightening torques, the order the screws are tightened has a significant influence on a clamped boring bars eigenfrequencies and its mode shapes orientation in the cutting speed—cutting depth plane. Also, the damping of the modes is influenced. The results indicate that multi-span Euler-Bernoulli beam models with pinned boundary condition or elastic boundary condition modeling the clamping are preferable as compared to a fixed-free Euler-Bernoulli beam for modeling dynamic properties of a clamped boring bar. It is also demonstrated that a standard clamping housing clamping a boring bar with clamping screws imposes non-linear dynamic boring bar behavior.

  20. Nonlinear vibrations of fluid-filled clamped circular cylindrical shells

    Science.gov (United States)

    Karagiozis, K. N.; Amabili, M.; Païdoussis, M. P.; Misra, A. K.

    2005-12-01

    In this study, the nonlinear vibrations are investigated of circular cylindrical shells, empty or fluid-filled, clamped at both ends and subjected to a radial harmonic force excitation. Two different theoretical models are developed. In the first model, the standard form of the Donnell's nonlinear shallow-shell equations is used; in the second, the equations of motion are derived by a variational approach which permits the inclusion of constraining springs at the shell extremities and taking in-plane inertial terms into account. In both cases, the solution includes both driven and companion modes, thus allowing for a travelling wave in the circumferential direction; they also include axisymmetric modes to capture the nonlinear inward shell contraction and the correct type (softening) nonlinear behaviour observed in experiments. In the first model, the clamped beam eigenfunctions are used to describe the axial variations of the shell deformation, automatically satisfying the boundary conditions, leading to a 7 degree-of-freedom (dof) expansion for the solution. In the second model, rotational springs are used at the ends of the shell, which when large enough reproduce a clamped end; the solution involves a sine series for axial variations of the shell deformation, leading to a 54 dof expansion for the solution. In both cases the modal expansions satisfy the boundary conditions and the circumferential continuity condition exactly. The Galerkin method is used to discretize the equations of motion, and AUTO to integrate the discretized equations numerically. When the shells are fluid-filled, the fluid is assumed to be incompressible and inviscid, and the fluid structure interaction is described by linear potential flow theory. The results from the two theoretical models are compared with existing experimental data, and in all cases good qualitative and quantitative agreement is observed.

  1. Stretching of proteins in a force-clamp

    Energy Technology Data Exchange (ETDEWEB)

    Szymczak, P [Institute of Theoretical Physics, Warsaw University, ulica Hoza 69, 00-681 Warsaw (Poland); Cieplak, Marek [Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland)

    2006-01-11

    Mechanically induced protein unfolding in the force-clamp apparatus is shown, in a coarse-grained model of ubiquitin, to have lognormal statistics above a threshold force and exponential statistics below it. Correspondingly, the mean unfolding time is slowly varying and exponentially decreases as a function of the force. The time dependences of the end-to-end distances are also distinct. The time sequence of unfolding events weakly depends on force and much of it resembles that for stretching at constant speed. A more complicated time dependence arises for integrin. (letter to the editor)

  2. Five-level Z-source diode-clamped inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, Poh Chiang; Blaabjerg, Frede;

    2010-01-01

    This study proposes a five-level Z-source diode-clamped inverter designed with two intermediate Z-source networks connected between the dc input sources and rear-end inverter circuitry. By partially shorting the Z-source networks, new operating states not previously reported for two-level Z...... scheme, which always inserts two partial shoot-through states per half carrier cycle for smooth balanced operation. Theoretical findings and practical issues identified are eventually verified by constructing a scaled down laboratory prototype for testing....

  3. Rare Inferior Shoulder Dislocation (Luxatio Erecta

    Directory of Open Access Journals (Sweden)

    Hakan Cift

    2015-01-01

    Full Text Available Although shoulder dislocations have been seen very frequently, inferior dislocation of shoulder constitutes only 0.5% of all shoulder dislocations. We share our 4 patients with luxatio erecta and present their last clinical control. 2 male and 2 female Caucasian patients were diagnosed as luxatio erecta. Patients’ ages were 78, 62, 65, and 76. All patients’ reduction was done by traction-abduction and contour traction maneuver in the operating room. The patients had no symptoms and no limitation of range of motion of their shoulder at their last control. Luxatio erecta is seen rarely, and these patients may have neurovascular injury. These patients should be carefully examined and treated by the orthopaedic and traumatology surgeons.

  4. Injuries of the inferior vena cava.

    Science.gov (United States)

    Burch, J M; Feliciano, D V; Mattox, K L; Edelman, M

    1988-12-01

    Beginning in 1946, 577 patients with inferior vena cava injuries were managed at a single institution. After decreasing from 37 to 30 percent, the mortality rate showed a distinct increase in the last 7 years studied. This increase was related to an increasing percentage of patients who arrived in the emergency center in severe shock and required resuscitative thoracotomy. In-hospital care advances have not kept pace with improvements in prehospital care. Although venous complications have not been infrequent, morbidity has not been a significant long-term problem. Fatal pulmonary embolism occurred and was a special problem for patients over the age of 50. More basic research is needed to expedite diagnosis and vascular control in addition to understanding and treating the severe metabolic problems of patients dying from shock and hemorrhage. PMID:3202271

  5. Bilateral inferior petrosal sinus sampling using vasopressin

    Directory of Open Access Journals (Sweden)

    Narendra Kotwal

    2016-01-01

    Full Text Available Context: Anatomical localization of pituitary adenoma can be challenging in adrenocorticotropic hormone (ACTH-dependent Cushing's syndrome, and bilateral inferior petrosal sinus sampling (BIPSS is considered gold standard in this regard. Stimulation using corticotrophin-releasing hormone (CRH improves the sensitivity of BIPSS, however, same is not easily available in India. Therefore, we undertook this study of BIPPS using vasopressin as agent for stimulation owing to its ability to stimulate V3 receptors present on corticotrophs. Aims: To study the tumor localization and lateralization in difficult to localize cases of ACTH-dependent Cushing's syndrome by bilateral inferior petrosal sinus sampling using vasopressin for corticotroph stimulation. Settings and Design: Prospective observational study. Subjects and Methods: Six patients (5 females meeting inclusion criteria underwent BIPSS using vasopressin for stimulation. Results: All six patients had nonsuppressible overnight and low dose dexamethasone suppression test with elevated plasma ACTH levels suggestive of ACTH-dependent Cushing's syndrome. High dose dexamethasone suppression test showed suppressible cortisol in two cases, and microadenoma was seen in two patients on magnetic resonance imaging pituitary. Contrast enhanced computed tomography of the abdomen showed left adrenal hyperplasia in one case and anterior mediastinal mass with bilateral adrenal hyperplasia another. Using BIPSS four patients were classified as having Cushing's disease that was confirmed histopathologically following surgery. Of the remaining two, one had primary pigmented nodular adrenocortical disease, and another had thymic carcinoid with ectopic ACTH production as the cause of Cushing's syndrome. No serious adverse events were noted. Conclusions: Vasopressin may be used instead of CRH and desmopressin for stimulation in BIPSS.

  6. Percutaneous insertion of the inferior vena cava filter

    International Nuclear Information System (INIS)

    Objective: To evaluate the effect of inferior vena cava filter for prevention of pulmonary embolus (PE) formation. Methods: Twenty-eight cases of deep venous thrombosis (DVT) were treated with insertion of the inferior vena cava filter. Results: The filter was implanted into inferior vena cava below the rena vein. There were no severe complications occurred in the group. Twenty-seven cases were followed up to 2-34 months, and no migration of the filters were found. And no pulmonary embolism were revealed in fifteen cases without pulmonary thromboembolism. Conclusions: The inferior vena cava filter implantation is a safe and effective method to prevent pulmonary thromboembolism

  7. A NOVEL SINGLE IMPEDANCE NETWORK BASED NEUTRAL POINT CLAMPED SEVEN LEVEL THREE PHASE INVETER WITH REDUCED CLAMPING DIODES FOR REGENERATIVE APPLICATIONS

    Directory of Open Access Journals (Sweden)

    T. A. Raghavendiran

    2012-09-01

    Full Text Available A Multilevel Inverter (MLI can eliminate the need for the step-up transformer and reduce the harmonics produced by the inverter. This paper presents Neutral Point Clamped (NPC seven level inverter with less number of clamping diodes which is suitable for regenerative loads such as three phase induction motor with regenerative braking. To reduce the stress across the main switches, diodes are clamped anti-parallel to the main switches. In Earlier configurations, the numbers of clamping diodes were increased proportionately with thenumber of levels and the number of impedance network required increases with increase number of levels. Therefore the cost and converter size increases as the number of levels goes high. In this paper a single impedance network based seven level neutral point clamped inverter with reduced number of clamping diodes without deterioration in performance is proposed, the simulation of proposed circuit is carried out using MATLAB/Simulink and the results for the same are presented. The MOSFET internal capacitance and body diodes are used for active clamping which eliminates the need for snubber circuit.

  8. Performance Evaluation of Multicarrier SPWM Strategies for Three Phase Z - source Seven Level Diode Clamped Inverter

    OpenAIRE

    V.Arun#1 , B.Shanthi

    2013-01-01

    This paper presents multicarrier PWM strategies for three phase diode clamped seven level Z-source inverter. Multilevel inverters posses the advantage of reduced harmonics,high power capability and high voltage level. Impedance network in the diode clamped multilevel inverter circuit will perform boost operation. This paper focuses on multicarriersinusoidal pulse width modulation (MCSPWM) strategy for the three phase seven level Z-source diode clamped inverter. Performance parameters of three...

  9. Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording.

    Science.gov (United States)

    Harrison, Reid R; Kolb, Ilya; Kodandaramaiah, Suhasa B; Chubykin, Alexander A; Yang, Aimei; Bear, Mark F; Boyden, Edward S; Forest, Craig R

    2015-02-15

    Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a custom patch-clamp amplifier microchip that can be fabricated using standard commercial silicon processes capable of performing both voltage- and current-clamp measurements. A key innovation is the use of nonlinear feedback elements in the voltage-clamp amplifier circuit to convert measured currents into logarithmically encoded voltages, thereby eliminating the need for large high-valued resistors, a factor that has limited previous attempts at integration. Benchtop characterization of the chip shows low levels of current noise [1.1 pA root mean square (rms) over 5 kHz] during voltage-clamp measurements and low levels of voltage noise (8.2 μV rms over 10 kHz) during current-clamp measurements. We demonstrate the ability of the chip to perform both current- and voltage-clamp measurement in vitro in HEK293FT cells and cultured neurons. We also demonstrate its ability to perform in vivo recordings as part of a robotic patch-clamping system. The performance of the patch-clamp amplifier microchip compares favorably with much larger commercial instrumentation, enabling benchtop commoditization, miniaturization, and scalable patch-clamp instrumentation. PMID:25429119

  10. Modeling of SVM Diode Clamping Three-Level Inverter Connected to Grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong;

    2011-01-01

    PLECS is used to model the diode clamping three-level inverter connected to grid and good results are obtained. First the output voltage SVM is described for diode clamping three-level inverter with loads connected to Y. Then the output voltage SVM of diode clamping three-level inverter is simply...... very powerful tool to real power circuits and it is very easy to simulate them. They have also verified that SVM control strategy is feasible to control the diode clamping three-level inverter....

  11. Cryogenic Clamp-on Ultrasonic Flowmeters using Single Crystal Piezoelectric Transducers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clamp-on ultrasound cryogenic flowmeters using single crystal piezoelectric transducers are proposed to enable reliable, accurate cryogenic instrumentation needs in...

  12. Clinical application and advancement of inferior vena cava filter

    International Nuclear Information System (INIS)

    Deep venous thrombosis is a common disorder, with a considerably high incidence and mortality. Inferior vena cava filter provides fruitful means in decrease and prevention of fatal pulmonary embolism. The authors reviewed the history, indications and applications of inferior vena cava filter for different types of deep venous thrombosis, with outlook of future trends. (authors)

  13. Self-clamping arc light reflector for welding torch

    Science.gov (United States)

    Gordon, Stephen S.

    1987-07-01

    This invention is directed to a coaxial extending metal mirror reflector attached to the electrode housing or gas cup on a welding torch. An electric welding torch with an internal viewing system for robotic welding is provded with an annular arc light reflector to reflect light from the arc back onto the workpiece. The reflector has a vertical split or gap in its surrounding wall to permit the adjacent wall ends forming the split to be sprung open slightly to permit the reflector to be removed or slipped onto the torch housing or gas cup. The upper opening of the reflector is slightly smaller than the torch housing or gas cup and therefore, when placed on the torch housing or gas cup has that springiness to cause it to clamp tightly on the housing or gas cup. The split or gap also serves to permit the feed of weld wire through to the weld area,

  14. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.;

    2012-01-01

    Transformer based Z-source (trans-Z-source) inverters are recently proposed by extending the traditional Z-source inverter with higher buck-boost capability as well as reducing the passive components at the same time. Multi-Level Z-source inverters are single-stage topological solutions used for...... buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...... modulation scheme, the three-level trans-Z-source inverter can function with minimum of six device commutations per half carrier cycle (same as the traditional buck NPC inverter), while maintaining to produce the designed volt-sec average and inductive voltage boosting at ac output terminals. The designed...

  15. Whole-cell Patch-clamp Recordings in Brain Slices.

    Science.gov (United States)

    Segev, Amir; Garcia-Oscos, Francisco; Kourrich, Saïd

    2016-01-01

    Whole-cell patch-clamp recording is an electrophysiological technique that allows the study of the electrical properties of a substantial part of the neuron. In this configuration, the micropipette is in tight contact with the cell membrane, which prevents current leakage and thereby provides more accurate ionic current measurements than the previously used intracellular sharp electrode recording method. Classically, whole-cell recording can be performed on neurons in various types of preparations, including cell culture models, dissociated neurons, neurons in brain slices, and in intact anesthetized or awake animals. In summary, this technique has immensely contributed to the understanding of passive and active biophysical properties of excitable cells. A major advantage of this technique is that it provides information on how specific manipulations (e.g., pharmacological, experimenter-induced plasticity) may alter specific neuronal functions or channels in real-time. Additionally, significant opening of the plasma membrane allows the internal pipette solution to freely diffuse into the cytoplasm, providing means for introducing drugs, e.g., agonists or antagonists of specific intracellular proteins, and manipulating these targets without altering their functions in neighboring cells. This article will focus on whole-cell recording performed on neurons in brain slices, a preparation that has the advantage of recording neurons in relatively well preserved brain circuits, i.e., in a physiologically relevant context. In particular, when combined with appropriate pharmacology, this technique is a powerful tool allowing identification of specific neuroadaptations that occurred following any type of experiences, such as learning, exposure to drugs of abuse, and stress. In summary, whole-cell patch-clamp recordings in brain slices provide means to measure in ex vivo preparation long-lasting changes in neuronal functions that have developed in intact awake animals

  16. Inferior patellar pole fragmentation in children: just a normal variant?

    International Nuclear Information System (INIS)

    Fragmentary ossification of the inferior patella is often dismissed as a normal variant in children younger than 10 years of age. The purpose of this study was to determine whether fragmentary inferior patellar pole ossification is a normal variant or is associated with symptoms or signs of pathology using MRI and clinical exam findings as reference. A retrospective review was performed on 150 patients ages 5-10 years who underwent 164 knee radiography and MRI exams (45.1% male, mean age: 7.8 years). The presence or absence of inferior patellar pole fragmentation on radiography was correlated with the presence or absence of edema-like signal on MR images. Clinical notes were reviewed for the presence of symptoms or signs referable to the inferior patellar pole. These data were compared with a 1:1 age- and sex-matched control group without inferior pole fragmentation. Statistical analysis was performed using two-tailed t-tests. Forty of 164 (24.4%) knee radiographs showed fragmentary ossification of the inferior patella. Of these 40 knees, 62.5% (25/40) had edema-like signal of the inferior patellar bone marrow compared with 7.5% (3/40) of controls (P = 0.035). Patients with fragmentary ossification at the inferior patella had a significantly higher incidence of documented focal inferior patellar pain compared with controls (20% vs. 2.5%, P = 0.015). Inferior patellar pole fragmentation in children 5 to 10 years of age may be associated with localized symptoms and bone marrow edema-like signal and should not be routinely dismissed as a normal variant of ossification. (orig.)

  17. Inferior patellar pole fragmentation in children: just a normal variant?

    Energy Technology Data Exchange (ETDEWEB)

    Kan, J.H.; Vogelius, Esben S.; Orth, Robert C.; Guillerman, R.P.; Jadhav, Siddharth P. [Texas Children' s Hospital, E.B. Singleton Pediatric Radiology, Houston, TX (United States)

    2015-06-15

    Fragmentary ossification of the inferior patella is often dismissed as a normal variant in children younger than 10 years of age. The purpose of this study was to determine whether fragmentary inferior patellar pole ossification is a normal variant or is associated with symptoms or signs of pathology using MRI and clinical exam findings as reference. A retrospective review was performed on 150 patients ages 5-10 years who underwent 164 knee radiography and MRI exams (45.1% male, mean age: 7.8 years). The presence or absence of inferior patellar pole fragmentation on radiography was correlated with the presence or absence of edema-like signal on MR images. Clinical notes were reviewed for the presence of symptoms or signs referable to the inferior patellar pole. These data were compared with a 1:1 age- and sex-matched control group without inferior pole fragmentation. Statistical analysis was performed using two-tailed t-tests. Forty of 164 (24.4%) knee radiographs showed fragmentary ossification of the inferior patella. Of these 40 knees, 62.5% (25/40) had edema-like signal of the inferior patellar bone marrow compared with 7.5% (3/40) of controls (P = 0.035). Patients with fragmentary ossification at the inferior patella had a significantly higher incidence of documented focal inferior patellar pain compared with controls (20% vs. 2.5%, P = 0.015). Inferior patellar pole fragmentation in children 5 to 10 years of age may be associated with localized symptoms and bone marrow edema-like signal and should not be routinely dismissed as a normal variant of ossification. (orig.)

  18. The deformation of an elastic rod with a clamp sliding along a smooth and curved profile

    CERN Document Server

    Misseroni, D; Zaccaria, D; Bigoni, D

    2015-01-01

    The design of compliant mechanisms is crucial in several technologies and relies on the availability of solutions for nonlinear structural problems. One of these solutions is given and experimentally validated in the present article for a compliant mechanism moving along a smooth curved profile. In particular, a deformable elastic rod is held by two clamps, one at each end. The first clamp is constrained to slide without friction along a curved profile, while the second clamp moves in a straight line transmitting its motion through the elastic rod to the first clamp. For this system it is shown that the clamp sliding on the profile imposes nontrivial boundary conditions (derived via a variational and an asymptotic approach), which strongly influence buckling and nonlinear structural behaviour. Investigation of this behaviour shows that a compliant mechanism can be designed, which gives an almost neutral response in compression. This behavior could easily be exploited to make a force limiting device. Finally a...

  19. A reduction clamp for an aiming component in associated acetabular fractures

    Directory of Open Access Journals (Sweden)

    Zhang-Fu Wang

    2015-01-01

    Full Text Available Background: The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed. Materials and Methods: In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures. Results: This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp′s aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use. Conclusion: This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

  20. Clamp ultrastructure of the basal monogenean Chimaericola leptogaster (Leuckart, 1830) (Polyopisthocotylea: Chimaericolidae).

    Science.gov (United States)

    Poddubnaya, Larisa G; Hemmingsen, Willy; Gibson, David I

    2014-11-01

    The ultrastructure of the haptoral clamps of the chimaericolid monogenean Chimaericola leptogaster, a basal polyopisthocotylean from the gills of a holocephalan fish, is described. These clamps are characterized by the presence of two muscle blocks interrupted mid-anteriorly and mid-posteriorly and different kinds of hard structures: a single median and paired lateral sclerites embedded in the clamp wall; six spine-like structures directed towards the clamp lumen; and electron dense surface structures along the internal surface of the anterior clamp lips and along the luminal surface of the tegument of the clamp lumen. The lateral sclerites are situated deep within muscular tissue and are closely bounded by radial myofibrils, possessing a uniform electron dense matrix within which are hollow areas of different sizes. The median sclerite occupies an area between the clamp wall myofibrils and the luminal epithelium, is surrounded by a basement lamina and is composed of a heterogeneous matrix comprising two different morphological layers related to variations in the type and concentration of fibrils. Four of the spine-like structures are extensions of the margins of the two spindle-like muscle blocks in the clamps, i.e. the two anterior and two posterior structures, and the two others are situated at the lateral constrictions of the left and right muscle blocks. The electron dense surface structures are derivations of the clamp tegument or, to be more precise, its outer, densely fibrous region. These results are discussed in relation to the evidence that the haptoral clamps of C. leptogaster are apparently ancient origin. PMID:25112214

  1. Neoplasms of the inferior vena cava - pictorial essay

    International Nuclear Information System (INIS)

    This pictorial essay reviews common and rare neoplasms affecting the inferior vena cava (IVC, Table 1), with a particular emphasis on the clinical implications and the role and efficacy of the various imaging techniques. (author)

  2. Voltage clamping single cells in intact malpighian tubules of mosquitoes.

    Science.gov (United States)

    Masia, R; Aneshansley, D; Nagel, W; Nachman, R J; Beyenbach, K W

    2000-10-01

    Principal cells of the Malpighian tubule of the yellow fever mosquito were studied with the methods of two-electrode voltage clamp (TEVC). Intracellular voltage (V(pc)) was -86.7 mV, and input resistance (R(pc)) was 388.5 kOmega (n = 49 cells). In six cells, Ba(2+) (15 mM) had negligible effects on V(pc), but it increased R(pc) from 325.3 to 684.5 kOmega (P usefulness of TEVC methods in single principal cells of the intact Malpighian tubule. Dinitrophenol (0.1 mM) reversibly depolarized V(pc) from -94.3 to -10.7 mV (P < 0.001) and reversibly increased R(pc) from 412 to 2,879 kOmega (P < 0.001), effects that were duplicated by cyanide (0.3 mM). Significant effects of metabolic inhibition on voltage and resistance suggest a role of ATP in electrogenesis and the maintenance of conductive transport pathways. PMID:10997925

  3. Analysis of Control Strategies for Diode Clamped Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    C. R. Balamurugan

    2013-05-01

    Full Text Available This paper presents the comparison of various Pulse Width Modulation (PWM strategies for the three phase Diode Clamped Multi Level Inverter (DCMLI. The main contribution of this paper is the proposal of new modulation schemes with Variable Amplitude (VA and various new schemes adopting the constant switching frequency and also variable switching frequency multicarrier control freedom degree combination concepts are developed and simulated for the chosen three phase DCMLI. The three phase DCMLI, is controlled in this paper with Sinusoidal PWM (SPWM reference along with triangular carriers and analysis is made among both without carrier overlapping and with Carrier Overlapping (CO techniques to choose the better strategy by performing simulation using MATLAB-SIMULINK. The variation of Total Harmonic Distortion (THD and fundamental RMS output voltage is observed for various modulation indices. It is observed that among the various equal amplitude PWM strategies, COPWM-C provides less THD and higher RMS voltage. It is recognized that among the various variable amplitude PWM strategies, VACOPWM-C provides less THD and VACOPWM-B provides higher RMS voltage. By comparing the equal amplitude PWM strategies with the variable amplitude PWM strategies it is inferred that VACOPWM-C provides less THD and VACOPWM-B provides higher RMS voltage. It is also inferred that carrier overlapping techniques provides better results compared to the without carrier overlapping techniques.

  4. Position clamping in a holographic counterpropagating optical trap.

    Science.gov (United States)

    Bowman, Richard; Jesacher, Alexander; Thalhammer, Gregor; Gibson, Graham; Ritsch-Marte, Monika; Padgett, Miles

    2011-05-01

    Optical traps consisting of two counterpropagating, divergent beams of light allow relatively high forces to be exerted along the optical axis by turning off one beam, however the axial stiffness of the trap is generally low due to the lower numerical apertures typically used. Using a high speed spatial light modulator and CMOS camera, we demonstrate 3D servocontrol of a trapped particle, increasing the stiffness from 0.004 to 1.5 μN m(-1). This is achieved in the "macro-tweezers" geometry [Thalhammer, J. Opt. 13, 044024 (2011); Pitzek, Opt. Express 17, 19414 (2009)], which has a much larger field of view and working distance than single-beam tweezers due to its lower numerical aperture requirements. Using a 10×, 0.2 NA objective, active feedback produces a trap with similar effective stiffness to a conventional single-beam gradient trap, of order 1 μN m(-1) in 3D. Our control loop has a round-trip latency of 10 ms, leading to a resonance at 20 Hz. This is sufficient bandwidth to reduce the position fluctuations of a 10 μm bead due to Brownian motion by two orders of magnitude. This approach can be trivially extended to multiple particles, and we show three simultaneously position-clamped beads. PMID:21643247

  5. Troubleshooting OptEase inferior vena cava filter retrieval.

    Science.gov (United States)

    Nakashima, Masaya; Kobayashi, Hideaki; Kobayashi, Masayoshi

    2016-01-01

    For treatment of deep vein thrombosis and prevention of pulmonary thromboembolism, a retrievable inferior vena cava filter is commonly utilized as an effective bridge to anticoagulation. However, we have experienced difficulties in retrieving inferior vena cava filters. Endovascular retrieval assisted by disposable biopsy forceps is an appropriate approach because it provides a less-invasive low-cost way to remove a migrated filter. We suggest this troubleshooting technique to deal with filter hook migration into the caval wall. PMID:24828829

  6. Concentrations of plastic strains in the clamping region of cylindrical shells under excessive loading

    International Nuclear Information System (INIS)

    Different clamping conditions and variations of the material behaviour are considered. Especially the plastic strain concentrations at the shell clamping are determined. The analyses have been carried out with a finite-element code. Standard stress analysis procedures like the ASME-code are critically assessed. The results show that only minor plastic strain concentrations have to be expected for a rigidly clamped shell loaded by internal pressure. The work hardening characteristic of the material has little influence on these strain concentrations. On the other hand considerable plastic strain concentrations have to be expected at a flange type clamping loaded by axial stresses in the shell. These concentrations depend on the work hardening characteristic of the material. Comparison of these analyses with standard stress analysis procedures shows that these procedures are conservative, provided the classification of the different types of stresses has been done in a correct way which, however, may be difficult for some problems. For instance, for the rigidly clamped shell bending stresses can be classified as secondary stresses, but for a flange type clamping bending stresses must be treated as primary stresses with lower limits. With these results the structural integrity of the core barrel clamping of a PWR under blowdown loading has been assessed. Even in case of a sudden and complete pipe break the structure is able to withstand blowdown loading. (orig./HP)

  7. Modelling the clamping force distribution among chips in press-pack IGBTs using the finite element method

    DEFF Research Database (Denmark)

    Hasmasan, Adrian Augustin; Busca, Christian; Teodorescu, Remus;

    2012-01-01

    In this paper, a FEM (finite element method) based mechanical model for PP (press-pack) IGBTs (insulated gate bipolar transistors) is presented, which can be used to calculate the clamping force distribution among chips under various clamping conditions. The clamping force is an important parameter...

  8. Voltage clamp of the cardiac sodium current at 37 degrees C in physiologic solutions.

    OpenAIRE

    Murray, K T; Anno, T.; Bennett, P B; Hondeghem, L M

    1990-01-01

    The cardiac sodium current was studied in guinea pig ventricular myocytes using the cell-attached patch voltage clamp at 37 degrees C in the presence of 145 mM external sodium concentration. When using large patch pipettes (access resistance, 1-2 M omega), the capacity current transient duration was typically 70 microseconds for voltage clamp steps up to 150 mV. At 37 degrees C the maximum inward sodium current peaked in approximately 200 microseconds after the onset of a clamp step and at th...

  9. Nuclear EMP: voltage clamping levels for several TransZorb transient suppression devices

    International Nuclear Information System (INIS)

    Voltage clamping levels for the 1N5629A, 1N5545A, 1N5654A, and 1N5664A TransZorb/sup T.M./ silicon transient-suppression devices in a DO-13 package are presented as data in photographs of test waveforms. A graph is compiled which illustrates the clamping voltage at a time point of 80 nsec for each of the devices. The duration of the test pulse was 250 nsec with a slope of 4 kV per nsec for the rise portion. Clamping levels are nearly constant for test current amplitudes of up to 120 A

  10. Analysis of the role of PCNA-DNA contacts during clamp loading

    Directory of Open Access Journals (Sweden)

    Goedken Eric R

    2010-01-01

    Full Text Available Abstract Background Sliding clamps, such as Proliferating Cell Nuclear Antigen (PCNA in eukaryotes, are ring-shaped protein complexes that encircle DNA and enable highly processive DNA replication by serving as docking sites for DNA polymerases. In an ATP-dependent reaction, clamp loader complexes, such as the Replication Factor-C (RFC complex in eukaryotes, open the clamp and load it around primer-template DNA. Results We built a model of RFC bound to PCNA and DNA based on existing crystal structures of clamp loaders. This model suggests that DNA would enter the clamp at an angle during clamp loading, thereby interacting with positively charged residues in the center of PCNA. We show that simultaneous mutation of Lys 20, Lys 77, Arg 80, and Arg 149, which interact with DNA in the RFC-PCNA-DNA model, compromises the ability of yeast PCNA to stimulate the DNA-dependent ATPase activity of RFC when the DNA is long enough to extend through the clamp. Fluorescence anisotropy binding experiments show that the inability of the mutant clamp proteins to stimulate RFC ATPase activity is likely caused by reduction in the affinity of the RFC-PCNA complex for DNA. We obtained several crystal forms of yeast PCNA-DNA complexes, measuring X-ray diffraction data to 3.0 Å resolution for one such complex. The resulting electron density maps show that DNA is bound in a tilted orientation relative to PCNA, but makes different contacts than those implicated in clamp loading. Because of apparent partial disorder in the DNA, we restricted refinement of the DNA to a rigid body model. This result contrasts with previous analysis of a bacterial clamp bound to DNA, where the DNA was well resolved. Conclusion Mutational analysis of PCNA suggests that positively charged residues in the center of the clamp create a binding surface that makes contact with DNA. Disruption of this positive surface, which had not previously been implicated in clamp loading function, reduces RFC

  11. Prehospital Nitroglycerin Safety in Inferior ST Elevation Myocardial Infarction.

    Science.gov (United States)

    Robichaud, Laurie; Ross, Dave; Proulx, Marie-Hélène; Légaré, Sébastien; Vacon, Charlene; Xue, Xiaoqing; Segal, Eli

    2016-01-01

    Patients with inferior ST elevation myocardial infarction (STEMI), associated with right ventricular infarction, are thought to be at higher risk of developing hypotension when administered nitroglycerin (NTG). However, current basic life support (BLS) protocols do not differentiate location of STEMI prior to NTG administration. We sought to determine if NTG administration is more likely to be associated with hypotension (systolic blood pressure vs. 8.9%, p = 0.73. A drop in systolic blood pressure ≥ 30 mmHg post NTG occurred in 23.4% of inferior STEMIs and 23.9% of non-inferior STEMIs, p = 0.87. Interrater agreement for chart review of the primary outcome was excellent (κ = 0.94). NTG administration to patients with chest pain and inferior STEMI on their computer-interpreted electrocardiogram is not associated with a higher rate of hypotension compared to patients with STEMI in other territories. Computer interpretation of inferior STEMI cannot be used as the sole predictor for patients who may be at higher risk for hypotension following NTG administration. PMID:26024432

  12. STUDY ON VARIATIONS OF INFERIOR SEGMENTAL BRANCH OF RENAL ARTERY

    Directory of Open Access Journals (Sweden)

    Chandragirish S

    2014-11-01

    Full Text Available Background: The segmental arteries of the kidney supply the organ in such a way that, each renal pole receives its own artery while, the anterior portion between the poles is supplied by an upper and lower segmental vessel. These two arteries also include in their territory the lateral edge of the kidney and adjacent to the strip of parenchyma on the dorsal or posterior aspect of the organ. The knowledge of inferior segmental branch of renal artery is very important for surgeries in its distribution area in kidney. Materials and Methods: 100 kidneys (Fifty pairs intact with abdominal aorta were collected from department of Forensic medicine, JSS Medical College and Mysore Medical College. For study of segmental variation Corrosion cast technique method was used. The variations of inferior segmental branch of renal artery were observed and recorded. Results: In present study type I inferior segmental branch of renal artery were found in - 59% cases, type II in - 6% cases, type III in - 28% cases, type IV in - 2% cases. Conclusion: The inferior segmental artery from the anterior division of the renal artery is the commonest event –arising in 59%. This is Type I, the normal type. It arises from the renal artery (28% or from the posterior division (6% or from the aorta (2%. The knowledge of inferior segmental branch of renal artery helpful in kidney transplantation and renal surgery because these type of surgeries success mainly depends on arterial ligations.

  13. The effects of inferior olive lesion on strychnine seizure

    International Nuclear Information System (INIS)

    Bilateral inferior olive lesions, produced by systemic administration of the neurotoxin 3-acetylpyridine (3AP) produce a proconvulsant state specific for strychnine-induced seizures and myoclonus. We have proposed that these phenomena are mediated through increased excitation of cerebellar Purkinje cells, through activation of glutamate receptors, in response to climbing fiber deafferentation. An increase in quisqualic acid (QA)-displaceable [3H]AMPA [(RS)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid] binding in cerebella from inferior olive-lesioned rats was observed, but no difference in [3H]AMPA binding displaced by glutamate, kainic acid (KA) or glutamate diethylester (GDEE) was seen. The excitatory amino acid antagonists GDEE and MK-801 [(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclo-hepten-5,10 imine] were tested as anticonvulsants for strychnine-induced seizures in 3AP inferior olive-lesioned and control rats. Neither drug effected seizures in control rats, however, both GDEE and MK-801 produced a leftward shift in the strychnine-seizure dose-response curve in 3AP inferior olive-lesioned rats. GDEE also inhibited strychnine-induced myoclonus in the lesioned group, while MK-801 had no effect on myoclonus. The decreased threshold for strychnine-induced seizures and myoclonus in the 3AP-inferior olive-lesioned rats may be due to an increase in glutamate receptors as suggested by the [3H]AMPA binding data

  14. Finite element analysis on factors influencing the clamping force in an electrostatic chuck

    International Nuclear Information System (INIS)

    As one of the core components of IC manufacturing equipment, the electrostatic chuck (ESC) has been widely applied in semiconductor processing such as etching, PVD and CVD. The clamping force of the ESC is one of the most important technical indicators. A multi-physics simulation software COMSOL is used to analyze the factors influencing the clamping force. The curves between the clamping force and the main parameters such as DC voltage, electrode thickness, electrode radius, dielectric thickness and helium gap are obtained. Moreover, the effects of these factors on the clamping force are investigated by means of orthogonal experiments. The results show that the factors can be ranked in order of voltage, electrode radius, helium gap and dielectric thickness according to their importance, which may offer certain reference for the design of ESCs. (semiconductor devices)

  15. BER improvement using optical gain clamped amplifier for burst transmission and critical cases studies

    OpenAIRE

    Zannin, Marcelo; Ennser, Karin; Taccheo, Stefano; Careglio, Davide; Solé Pareta, Josep; Aracil Rico, Javier

    2009-01-01

    This paper demonstrates significant BER improvement in burst traffic transmission using optical-gain clamped amplifiers. Critical chaotic cases are identified for peculiar burst sequences and their impact in transmission is assessed.

  16. Effective amplification of real WDM burst traffic using optical gain clamping

    OpenAIRE

    Zannin, Marcelo; Taccheo, Stefano; Ennser, Karin; Careglio, Davide; Solé Pareta, Josep

    2008-01-01

    Experimental studies of real optical burst traffic in WDM systems are performed with optical gain clamping for stabilizing the EDFA amplification. Impairments of power variation due to burst are shown to be negligible.

  17. Suppression of Spiral Waves by Voltage Clamp Techniques in a Conductance-Based Cardiac Tissue Model

    Institute of Scientific and Technical Information of China (English)

    YU Lian-Chun; MA Jun; ZHANG Guo-Yong; CHEN Yong

    2008-01-01

    A new control method is proposed to control the spatio-temporal dynamics in excitable media, which is described by the Morris-Lecar cells model. It is confirmed that successful suppression of spiral waves can be obtained by spatially clamping the membrane voltage of the excitable cells. The low voltage clamping induces breakup of spiral waves and the fragments are soon absorbed by low voltage obstacles, whereas the high voltage clamping generates travel waves that annihilate spiral waves through collision with them. However, each method has its shortcomings. Furthermore, a two-step method that combines both low and high voltage clamp techniques is then presented as a possible way of out this predicament.

  18. Anterior ST segment depression in acute inferior myocardial infarction as a marker of greater inferior, apical, and posterolateral damage

    International Nuclear Information System (INIS)

    The clinical significance of anterior precordial ST segment depression during acute inferior myocardial infarction was evaluated in 67 consecutive patients early after onset of symptoms with gated blood pool scans, thallium-201 perfusion images, and 12-lead ECGs. Patients with anterior ST depression (n = 33) had depressed mean values for left ventricular ejection fraction (54 +/- 2% [mean +/- S.E.M.] vs 59 +/- 2%; p = 0.02), cardiac index (3.1 +/- 0.2 vs 3.6 +/- 0.2 L/m2; p = 0.03), and ratio of systolic blood pressure to end-systolic volume (2.0 +/- 0.1 vs 2.5 +/- 0.3 mm Hg/ml; p = 0.04) compared to patients with no anterior ST depression (n = 34). Patients with anterior ST depression had (1) lower mean wall motion values for the inferior, apical, and inferior posterolateral segments (p less than 0.05) and (2) greater reductions in thallium-201 uptake in the inferior and posterolateral regions (p less than 0.05). However, anterior and septal (1) wall motion and (2) thallium-201 uptake were similar in patients with and without ST depression. Thus, anterior precordial ST segment depression in patients with acute inferior wall myocardial infarction represents more than a reciprocal electrical phenomenon. It identifies patients with more severe wall motion impairment and greater hypoperfusion of the inferior and adjacent segments. The poorer global left ventricular function in these patients is a result of more extensive inferior infarction and not of remote septal or anterior injury

  19. A novel voltage clamp technique for mapping ionic currents from cultured skeletal myotubes.

    OpenAIRE

    Anson, B D; Roberts, W M

    1998-01-01

    The biophysical properties and cellular distribution of ion channels largely determine the input/output relationships of electrically excitable cells. A variety of patch pipette voltage clamp techniques are available to characterize ionic currents. However, when used by themselves, such techniques are not well suited to the task of mapping low-density channel distributions. We describe here a new voltage clamp method (the whole cell loose patch (WCLP) method) that combines whole-cell recordin...

  20. Delayed umbilical cord clamping after childbirth: potential benefits to baby's health

    Directory of Open Access Journals (Sweden)

    Uwins C

    2014-11-01

    Full Text Available Christina Uwins,1 David JR Hutchon2 1Department of Obstetrics and Gynaecology, Croydon University Hospital, Croydon, 2Department of Obstetrics, Darlington Memorial Hospital, Darlington, UKAbstract: Early cord clamping was initially introduced as part of the package of care known as “active management of the third stage”, which was implemented to reduce postpartum hemorrhage. It has now been shown to provide no benefit to the mother and to result in harm to the neonate. The clinical trial evidence relating to delayed cord clamping compared to immediate cord clamping is presented and the physiological rationale for delayed cord clamping is discussed in this paper. Most organizations (eg World Health Organization (WHO, Royal College of Obstetricians and Gynaecologists (RCOG, Resuscitation Council (UK,The International Federation of Gynecology and Obstetrics (FIGO, International Confederation of Midwives, International Liaison Committee on Resuscitation (ILCOR and the European Resuscitation Council now advise a delay of 1–3 minutes before clamping the cord in term and preterm infants, and clinicians need to be aware of this change. Healthy neonates benefit from a more physiological and gentle transition from placental to pulmonary respiration, and we explain why this benefit should be provided to all neonates until there is any evidence to the contrary. The harm of early cord clamping is not limited to anemia and iron deficiency, and evidence for a wide range of possible harms of early cord clamping is presented. The need for resuscitation is one of the most common concerns, and ways of overcoming these concerns are described.Keywords: transition, cord clamping, hypovolemia, intraventricular hemorrhage

  1. Development of a Reusable, Low-Shock Clamp Band Separation System for Small Spacecraft Release Applications

    OpenAIRE

    Dowen, David; Christiansen, Scott; Peffer, Andrew

    2001-01-01

    In small spacecraft, the proximity of sensitive components to release systems has led to the need for lowshock spacecraft release systems. Marmon band systems are often desirable for their flight history, structural capability, and reliability. Until recently, only pyrotechnically released clamp bands were readily available. The clamp band system described in ths paper reduces shock in two ways: it eliminates shock typically associated with pyrotechnic release devices as well as utilizing a r...

  2. Patch Clamp: A Powerful Technique for Studying the Mechanism of Acupuncture

    Directory of Open Access Journals (Sweden)

    D. Zhang

    2012-01-01

    Full Text Available Cellular and molecular events can be investigated using electrophysiological techniques. In particular, the patch-clamp method provides detailed information. In addition, the patch-clamp technique has become a powerful method for investigating the mechanisms underlying the effects of acupuncture. In this paper, recent researches on how acupuncture might modulate electrophysiological responses in the central nervous system (CNS and affect peripheral structures are reviewed.

  3. Three Level Diode Clamped Inverter Fed Induction Motor with Dtc-Svm

    OpenAIRE

    V. Ranjith Kumar

    2013-01-01

    This project presents a three-level diode-clamped inverter feeding an asynchronous motor drive with direct torque control (DTC). The control method is based on DTC operating principles. The stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a diode-clamped inverter, where each phase of the inverter can be implemented using a dc source, which would be available from fuel c...

  4. Active Clamped ZVS Forward Converter With Soft-Switched Synchronous Rectifier

    OpenAIRE

    AÇIK, Adnan; ÇADIRCI, Işık

    2002-01-01

    This paper presents the analysis, design and implementation of an active-clamped, ZVS forward converter equipped with a soft-switched synchronous rectifier (ACFC-SR) proposed for high-efficiency, low output voltage dc-dc converter applications. The converter efficiency is maximized due to the soft-switching of the main, active clamp, synchronous rectifier and freewheeling MOSFET switches. The operating principles of the ACFC-SR are analyzed in detail and the converter performance is ...

  5. Deformation and perforation of clamped work-hardening plates struck transversely by blunt missiles

    International Nuclear Information System (INIS)

    A simple theory is given in this paper for the behaviour of clamped circular work-hardening plates struck transversely by flat-ended projectiles which travel at low velocities. By closely following the previous studies, force-displacement relationships are obtained and used to predict the deformation and perforation of the plates. It is shown that the theoretical predictions agree well with the experimental results on fully clamped steel plates when strain rate effects are taken into account. (orig.)

  6. Single-stage active clamp power factor correction AC/DC converter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A simple single-stage AC/DC converter circuit with active clamp is presented. The operation theory and state are analyzed. The experimental results show that the voltage across main switch can be clamped to a certain value, and zero voltage switching (ZVS) can be achieved. The voltage stress and switching loss are both decreased. In range of the whole load, power factors can be always more than 97%, and the highest efficiency can reach 88%.

  7. Modeling CICR in rat ventricular myocytes: voltage clamp studies

    Directory of Open Access Journals (Sweden)

    Palade Philip T

    2010-11-01

    Full Text Available Abstract Background The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR in cardiac myocytes, with voltage clamp (VC studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect Ca2+ loading of the sarcoplasmic reticulum (SR, and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR Ca2+ release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic Ca2+ concentration ([Ca2+]myo. Methods The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU, in which resides the mechanistic basis of CICR. The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed Ca2+ channels (trigger-channel and release-channel. It releases Ca2+ flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[Ca2+]myo. Results Our model reproduces measured VC data published by several laboratories, and generates graded Ca2+ release at high Ca2+ gain in a homeostatically-controlled environment where [Ca2+]myo is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR Ca2+ release, its activation by trigger Ca2+, and its

  8. MEMS-based clamp with a passive hold function for precision position retaining of micro manipulators

    International Nuclear Information System (INIS)

    In this paper the design, modeling and fabrication of a precision MEMS-based clamp with a relatively large clamping force are presented. The purpose of the clamp is to mechanically fix a six-degree-of-freedom (DOF) MEMS-based sample manipulator (Brouwer et al J. Int. Soc. Precis. Eng. Nanotechnol. submitted) once the sample has been positioned in all DOFs. The clamping force is generated by a rotational electrostatic comb-drive actuator and can be latched passively by a parallel plate type electrostatically driven locking device. The clamp design is based on the principles of exact constraint design, resulting in a high actuation compliance (flexibility) combined with a high suspension stiffness. Therefore, a relatively large blocking force of 1.4 mN in relation to the used area of 1.8 mm2 is obtained. The fabrication is based on silicon bulk micromachining technology and combines a high-aspect-ratio deep reactive ion etching (DRIE), conformal deposition of low-pressure chemical vapor deposition (LPCVD) silicon nitride and an anisotropic potassium hydroxide (KOH) backside etching technology. Special attention is given to void reduction of SixNy trench isolation and reduction of heating phenomena during front-side release etching. Guidelines are given for the applied process. Measurements showed that the clamp was able to fix, hold and release a test actuator. The dynamic behavior was in good agreement with the modal analysis

  9. Early identification of hERG liability in drug discovery programs by automated patch clamp

    Directory of Open Access Journals (Sweden)

    Timm eDanker

    2014-09-01

    Full Text Available Blockade of the cardiac ion channel coded by hERG can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms.

  10. Effect of non-ideal clamping shape on the resonance frequencies of silicon nanocantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Guillon, Samuel; Saya, Daisuke; Mazenq, Laurent; Nicu, Liviu [CNRS, LAAS, 7 Avenue du Colonel Roche, F-31077 Toulouse Cedex 4 (France); Perisanu, Sorin; Vincent, Pascal [LPMCN, Universite Claude Bernard Lyon 1 et CNRS, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Lazarus, Arnaud; Thomas, Olivier, E-mail: sguillon@laas.fr [Structural Mechanics and Coupled Systems Laboratory, Conservatoire National des Arts et Metiers, 2 rue Conte, 75003 Paris (France)

    2011-06-17

    In this paper, we investigate the effects of non-ideal clamping shapes on the dynamic behavior of silicon nanocantilevers. We fabricated silicon nanocantilevers using silicon on insulator (SOI) wafers by employing stepper ultraviolet (UV) lithography, which permits a resolution of under 100 nm. The nanocantilevers were driven by electrostatic force inside a scanning electron microscope (SEM). Both lateral and out-of-plane resonance frequencies were visually detected with the SEM. Next, we discuss overhanging of the cantilever support and curvature at the clamping point in the silicon nanocantilevers, which generally arises in the fabrication process. We found that the fundamental out-of-plane frequency of a realistically clamped cantilever is always lower than that for a perfectly clamped cantilever, and depends on the cantilever width and the geometry of the clamping point structure. Using simulation with the finite-elements method, we demonstrate that this discrepancy is attributed to the particular geometry of the clamping point (non-zero joining curvatures and a flexible overhanging) that is obtained in the fabrication process. The influence of the material orthotropy is also investigated and is shown to be negligible.

  11. Peptide- and proton-driven allosteric clamps catalyze anthrax toxin translocation across membranes.

    Science.gov (United States)

    Das, Debasis; Krantz, Bryan A

    2016-08-23

    Anthrax toxin is an intracellularly acting toxin in which sufficient information is available regarding the structure of its transmembrane channel, allowing for detailed investigation of models of translocation. Anthrax toxin, comprising three proteins-protective antigen (PA), lethal factor (LF), and edema factor-translocates large proteins across membranes. Here we show that the PA translocase channel has a transport function in which its catalytic active sites operate allosterically. We find that the phenylalanine clamp (ϕ-clamp), the known conductance bottleneck in the PA translocase, gates as either a more closed state or a more dilated state. Thermodynamically, the two channel states have >300-fold different binding affinities for an LF-derived peptide. The change in clamp thermodynamics requires distant α-clamp and ϕ-clamp sites. Clamp allostery and translocation are more optimal for LF peptides with uniform stereochemistry, where the least allosteric and least efficiently translocated peptide had a mixed stereochemistry. Overall, the kinetic results are in less agreement with an extended-chain Brownian ratchet model but, instead, are more consistent with an allosteric helix-compression model that is dependent also on substrate peptide coil-to-helix/helix-to-coil cooperativity. PMID:27506790

  12. A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

    Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

  13. Variant Inferior Alveolar Nerves and Implications for Local Anesthesia.

    Science.gov (United States)

    Wolf, Kevin T; Brokaw, Everett J; Bell, Andrea; Joy, Anita

    2016-01-01

    A sound knowledge of anatomical variations that could be encountered during surgical procedures is helpful in avoiding surgical complications. The current article details anomalous morphology of inferior alveolar nerves encountered during routine dissection of the craniofacial region in the Gross Anatomy laboratory. We also report variations of the lingual nerves, associated with the inferior alveolar nerves. The variations were documented and a thorough review of literature was carried out. We focus on the variations themselves, and the clinical implications that these variations present. Thorough understanding of variant anatomy of the lingual and inferior alveolar nerves may determine the success of procedural anesthesia, the etiology of pathologic processes, and the avoidance of surgical misadventure. PMID:27269666

  14. M. tuberculosis sliding β-clamp does not interact directly with the NAD+-dependent DNA ligase.

    Directory of Open Access Journals (Sweden)

    Vandna Kukshal

    Full Text Available The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp to 3.0 Å resolution. The protein crystallized in the space group C222(1 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent K(d of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD(+-dependent DNA ligase (LigA and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria.

  15. Pseudo-dissection of ascending aorta in inferior myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Grahame K. Goode

    2011-06-01

    Full Text Available Acute aortic dissection is a cardiac emergency which can present as inferior myocardial infarction. It has high morbidity and mortality requiring prompt diagnosis and treatment. Rapid advances in noninvasive imaging modalities have facilitated the early diagnosis of this condition and in ruling out this potentially catastrophic illness. We report an interesting case of a 57 year- old -man who presented with inferior myocardial infarction requiring thrombolysis and temporary pacing wire for complete heart block. An echocardiogram was highly suspicious of aortic dissection. CT scan confirmed that the malposition of the temporary pacing wire through the aorta mimicked aortic dissection.

  16. Simulation of inferior mirages observed at the Halligen Sea

    Science.gov (United States)

    Tränkle, Eberhard

    1999-08-01

    Two unusual forms of inferior mirage are observed and photographed at the Halligen Sea. With heuristic analytic functions for the temperature profiles, numerical integration of the refraction differ-ential equation on a flat earth is performed. The simulation shows that a double inferior mirage can appear if a light wind carries hot air from above dry sandbanks in the mud flats. Horizontal stripes can appear in the mirage image if a water channel crosses the line of sight between the observer and the object.

  17. Inferior glenohumeral joint dislocation with greater tuberosity avulsion

    Institute of Scientific and Technical Information of China (English)

    Mohd Faizan; Latif Zafar Jilani; Mazhar Abbas; Yasir Salam Siddiqui; Aamir Bin Sabir; M.K.A.Sherwani; Saifullah Khalid

    2015-01-01

    Inferior glenohumeral dislocation is the least common type of glenohumeral dislocations.It may be associated with fractures of the adjacent bones and neurovascular compromise.It should be treated immediately by close reduction.The associated neuropraxia usually recovers with time.Traction-counter traction method is commonly used for reduction followed by immobilization of the shoulder for three weeks.Here,we report a case of inferior glenohumeral joint dislocation with greater tuberosity fracture with transient neurovascular compromise and present a brief review of the literature.

  18. Yielding of the clamped-wire system in the Ilizarov external fixator.

    Science.gov (United States)

    Watson, M A; Matthias, K J; Maffulli, N; Hukins, D W L

    2003-01-01

    This study demonstrates that the clamped-wire system used to suspend bones within an Ilizarov external fixator yields when the perpendicular load exceeds 50 N per wire. Cyclic loading was applied to tensioned wires clamped within an Ilizarov ring component, with steadily increasing load amplitude. Wires were tested at four initial tension settings. The amount of energy lost within the clamped-wire system per load cycle was calculated for every test. The results showed that there was a consistent trend to increasing non-recoverable energy loss per load cycle when peak loads exceed 50 N for all initial tension settings. A finite element (FE) model replicating the experimental conditions was performed to investigate the levels of stress within the loaded wires. The FE model analyses showed that high stresses were generated in the wires close to the clamping sites, and that the stress levels could reasonably be expected to exceed the material yield stress when loaded to about 55 N, for all initial tension settings. The results show that material yield, accompanied by some wire slippage through the clamps, is responsible for system yield, in agreement with previous studies. Although the initial wire tension has an appreciable effect on the wire stiffness, it did not affect the elastic load range of the clamped-wire system. To prevent yield of the clamped-wire system in practice, the fixator should be assembled with sufficient wires to ensure that the load transmitted to each wire by the patient does not exceed 50 N. PMID:14558649

  19. Intermittent selective clamping improves rat liver regeneration by attenuating oxidative and endoplasmic reticulum stress.

    Science.gov (United States)

    Ben Mosbah, I; Duval, H; Mbatchi, S-F; Ribault, C; Grandadam, S; Pajaud, J; Morel, F; Boudjema, K; Compagnon, P; Corlu, A

    2014-01-01

    Intermittent clamping of the portal trial is an effective method to avoid excessive blood loss during hepatic resection, but this procedure may cause ischemic damage to liver. Intermittent selective clamping of the lobes to be resected may represent a good alternative as it exposes the remnant liver only to the reperfusion stress. We compared the effect of intermittent total or selective clamping on hepatocellular injury and liver regeneration. Entire hepatic lobes or only lobes to be resected were subjected twice to 10 min of ischemia followed by 5 min of reperfusion before hepatectomy. We provided evidence that the effect of intermittent clamping can be damaging or beneficial depending to its mode of application. Although transaminase levels were similar in all groups, intermittent total clamping impaired liver regeneration and increased apoptosis. In contrast, intermittent selective clamping improved liver protein secretion and hepatocyte proliferation when compared with standard hepatectomy. This beneficial effect was linked to better adenosine-5'-triphosphate (ATP) recovery, nitric oxide production, antioxidant activities and endoplasmic reticulum adaptation leading to limit mitochondrial damage and apoptosis. Interestingly, transient and early chaperone inductions resulted in a controlled activation of the unfolded protein response concomitantly to endothelial nitric oxide synthase, extracellular signal-regulated kinase-1/2 (ERK1/2) and p38 MAPK activation that favors liver regeneration. Endoplasmic reticulum stress is a central target through which intermittent selective clamping exerts its cytoprotective effect and improves liver regeneration. This procedure could be applied as a powerful protective modality in the field of living donor liver transplantation and liver surgery. PMID:24603335

  20. Duodenal Perforation Caused by an Inferior Vena Cava Filter

    OpenAIRE

    Bae, Mi Ju; Chung, Sung Woon; Lee, Chung Won; Kim, Sangpil; Song, Seunghwan

    2012-01-01

    The inferior vena cava (IVC) filter is known as an effective and safe method for preventing fatal pulmonary thromboembolism in patients with deep vein thrombosis. Usually, the remaining IVC filters are asymptomatic and do not cause clinical problems. We report a case of duodenal perforation caused by a remaining IVC filter.

  1. Duodenal perforation caused by an inferior vena cava filter.

    Science.gov (United States)

    Bae, Mi Ju; Chung, Sung Woon; Lee, Chung Won; Kim, Sangpil; Song, Seunghwan

    2012-02-01

    The inferior vena cava (IVC) filter is known as an effective and safe method for preventing fatal pulmonary thromboembolism in patients with deep vein thrombosis. Usually, the remaining IVC filters are asymptomatic and do not cause clinical problems. We report a case of duodenal perforation caused by a remaining IVC filter. PMID:22363914

  2. Hepatic and postrenal segment anomalies of inferior vena cava

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Yeon Hyeon; Park, Jae Hyung; Yeon, Kyung Mo; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1986-06-15

    Postrenal segment anomalies of inferior vena cava such as bilateral inferior vena cava and left-sided inferior vena cava can simulate lymphadenopathy on CT scan and these anomalous veins need consideration in retroperitoneal operations such as procedures for prevention of venous embolism, splenorenal shunt operation and aortic prosthetic replacement. Retrocaval ureter is a rare cause of obstructive uropathy or medical deviation of ureter. We analyzed 16 cases of postrenal segment anomalies diagnosed by CT, vena cavography, retrograde pyelography and ultrasonography including six rare positional anomalies at hepatic segment of inferior vena cava diagnosed by cardiac angiography. The results were as follows. 1. Postrenal segment anomalies were 6 cases of bilateral IVC, 8 cases of left-sided IVC and 2 cases of retrocaval ureters. On CT scan, 3 cases of bilateral IVC and 4 cases of left-sided IVC were accompanied by malignant tumors, but caval veins could be discriminated from enlarged nodes because of continuous tubular nature of vein on consecutive sections with homogeneous strong enhancement. Two cases of retrocaval ureters showed hydroureteronephrosis due to ureteral compression by IVC. 2. Hepatic segment anomalies were 6 cases. Five cases of IVC on left side of vertebra crossed midline at live to enter right-sided right atrium and one case of IVC on right side crossed midline to enter left-sided right atrium. Four cases of complex cardiac anomalies, 4 cases of annapolis and 2 cases of situs ambiguous were associated with these anomalies.

  3. Inferior Colliculus Lesions Impair Eyeblink Conditioning in Rats

    Science.gov (United States)

    Freeman, John H.; Halverson, Hunter E.; Hubbard, Erin M.

    2007-01-01

    The neural plasticity necessary for acquisition and retention of eyeblink conditioning has been localized to the cerebellum. However, the sources of sensory input to the cerebellum that are necessary for establishing learning-related plasticity have not been identified completely. The inferior colliculus may be a source of sensory input to the…

  4. Transhepatic approach for extracardiac inferior cavopulmonary connection stent fenestration.

    LENUS (Irish Health Repository)

    Kenny, Damien

    2012-02-01

    We report on a 3-year-old male who underwent transcatheter stent fenestration of the inferior portion of an extracardiac total cavopulmonary connection in the setting of hypoplastic left heart syndrome. Transhepatic approach, following an unsuccessful attempt from the femoral vein facilitated delivery of a diabolo-shaped stent.

  5. Unilateral Breast Reconstruction Using Bilateral Inferior Gluteal Artery Perforator Flaps

    Directory of Open Access Journals (Sweden)

    Toshihiko Satake, MD

    2015-03-01

    Conclusions: Use of bilateral IGAP flaps for breast reconstruction helps to avoid asymmetry of the inferior buttock volume and shape. Bilateral flaps provide sufficient tissue volume and allow for reconstruction of a breast comparable to the unaffected side. In patients with moderate-to-high projection breast whose abdominal tissue cannot be used for reconstruction, IGAP flaps may be a suitable alternative.

  6. Clampe de Ganz no tratamento de urgência em lesões do anel pélvico Ganz clamps to treat emergencies in pelvic ring lesions

    Directory of Open Access Journals (Sweden)

    Gilberto José Cação Pereira

    2008-07-01

    Full Text Available OBJETIVO: Avaliar a eficiência do clampe de Ganz na estabilização e redução dos deslocamentos da pelve, quando utilizado no tratamento de urgência, além de aquilatar eventuais dificuldades e facilidades do método. MÉTODOS: O clampe de Ganz foi utilizado no tratamento de urgência em 31 pacientes com graves lesões do anel pélvico (Tile C associadas a importante instabilidade hemodinâmica. RESULTADO: Entre os pacientes, 27 (87,1% apresentaram evolução favorável, com estabilização, redução dos deslocamentos e compressão da região posterior do anel, além de estabilização hemodinâmica, e quatro (12,9% evoluíram para óbito. CONCLUSÃO: O clampe de Ganz mostrou-se eficiente ferramenta no tratamento de urgência das lesões do anel pélvico, por ser de concepção simples, de rápida colocação, não impedir ou dificultar procedimentos no abdome e, principalmente, por permitir a estabilização da pelve, redução dos deslocamentos e compressão na região posterior do anel, local onde ocorrem os maiores sangramentos, reduzindo-os ou eliminando-os.OBJECTIVE: To evaluate the effectiveness of Ganz clamp to stabilize and reduce pelvic dislocations in emergency situations, and to assess possible difficult and easy aspects of the method. METHOD: Ganz clamp was used in the emergency treatment of 31 patients with severe lesions of the pelvic ring (Tile C associated to major hemodynamic instability. RESULTS: Among the patients, 27 (87.1% presented a favorable evolution, with stabilization, reduction of dislocations, and compression of the posterior portion of the ring, and also hemodynamic stabilization, and 4 (12.9% died. CONCLUSION: The Ganz clamp was found to be an effective tool in the emergency treatment of pelvic ring lesions because it has an uncomplicated conception, allowing for a fast placement, because it does not prevent nor make it difficult for abdominal procedures, and most of all because it allows for the

  7. A bacterial toxin inhibits DNA replication elongation through a direct interaction with the β sliding clamp.

    Science.gov (United States)

    Aakre, Christopher D; Phung, Tuyen N; Huang, David; Laub, Michael T

    2013-12-12

    Toxin-antitoxin (TA) systems are ubiquitous on bacterial chromosomes, yet the mechanisms regulating their activity and the molecular targets of toxins remain incompletely defined. Here, we identify SocAB, an atypical TA system in Caulobacter crescentus. Unlike canonical TA systems, the toxin SocB is unstable and constitutively degraded by the protease ClpXP; this degradation requires the antitoxin, SocA, as a proteolytic adaptor. We find that the toxin, SocB, blocks replication elongation through an interaction with the sliding clamp, driving replication fork collapse. Mutations that suppress SocB toxicity map to either the hydrophobic cleft on the clamp that binds DNA polymerase III or a clamp-binding motif in SocB. Our findings suggest that SocB disrupts replication by outcompeting other clamp-binding proteins. Collectively, our results expand the diversity of mechanisms employed by TA systems to regulate toxin activity and inhibit bacterial growth, and they suggest that inhibiting clamp function may be a generalizable antibacterial strategy. PMID:24239291

  8. Dynamics of beta and proliferating cell nuclear antigen sliding clamps in traversing DNA secondary structure.

    Science.gov (United States)

    Yao, N; Hurwitz, J; O'Donnell, M

    2000-01-14

    Chromosomal replicases of cellular organisms utilize a ring shaped protein that encircles DNA as a mobile tether for high processivity in DNA synthesis. These "sliding clamps" have sufficiently large linear diameters to encircle duplex DNA and are perhaps even large enough to slide over certain DNA secondary structural elements. This report examines the Escherichia coli beta and human proliferating cell nuclear antigen clamps for their ability to slide over various DNA secondary structures. The results show that these clamps are capable of traversing a 13-nucleotide ssDNA loop, a 4-base pair stem-loop, a 4-nucleotide 5' tail, and a 15-mer bubble within the duplex. However, upon increasing the size of these structures (20-nucleotide loop, 12-base pair stem-loop, 28-nucleotide 5' tail, and 20-nucleotide bubble) the sliding motion of the beta and proliferating cell nuclear antigen over these elements is halted. Studies of the E. coli replicase, DNA polymerase III holoenzyme, in chain elongation with the beta clamp demonstrate that upon encounter with an oligonucleotide annealed in its path, it traverses the duplex and resumes synthesis on the 3' terminus of the oligonucleotide. This sliding and resumption of synthesis occurs even when the oligonucleotide contains a secondary structure element, provided the beta clamp can traverse the structure. However, upon encounter with a downstream oligonucleotide containing a large internal secondary structure, the holoenzyme clears the obstacle by strand displacing the oligonucleotide from the template. Implications of these protein dynamics to DNA transactions are discussed. PMID:10625694

  9. Functional dissection of synaptic circuits: in vivo patch-clamp recording in neuroscience

    Directory of Open Access Journals (Sweden)

    Yi Zhou

    2015-05-01

    Full Text Available Neuronal activity is dominated by synaptic inputs from excitatory or inhibitory neural circuits. With the development of in vivo patch-clamp recording, especially in vivo voltage-clamp recording, researchers can not only directly measure neuronal activity, such as spiking responses or membrane potential dynamics, but also quantify synaptic inputs from excitatory and inhibitory circuits in living animals. This approach enables researchers to directly unravel different synaptic components and to understand their underlying roles in particular brain functions. Combining in vivo patch-clamp recording with other techniques, such as two-photon imaging or optogenetics, can provide even clearer functional dissection of the synaptic contributions of different neurons or nuclei. Here, we summarized current applications and recent research progress using the in vivo patch-clamp recording method and focused on its role in the functional dissection of different synaptic inputs. The key factors of a successful in vivo patch-clamp experiment and possible solutions based on references and our experiences were also discussed.

  10. Gain-clamping techniques in two-stage double-pass L-band EDFA

    Indian Academy of Sciences (India)

    S W harun; N Md Samsuri; H Ahmad

    2006-03-01

    Two designs of long-wavelength band erbium-doped fiber amplifier (L-band EDFA) for gain clamping in double-pass systems are demonstrated and compared. The first design is based on ring laser technique where a backward amplified spontaneous emission (ASE) from the second stage is routed into the feedback loop to create an oscillating laser for gain clamping. The gain is clamped at 18.6 dB from -40 to -8 dBm with a gain variation of less than ± 0.1 dB and a noise figure of less than 6 dB. Another scheme is based on partial reflection of ASE into the EDFA, which is demonstrated using a narrowband fiber Bragg grating. This scheme achieves a good gain clamping characteristic up to -12 dBm of input signal power with a gain variation of less than ± 0.3 dB from a clamped gain of 22 dB. The noise figure of a 1580 nm signal is maintained below 5 dB in this amplifier since this scheme is not based on lasing mechanism. The latter scheme is also expected to be free from the relaxation oscillation problem.

  11. Nonlinear Bending Stiffness of Plates Clamped by Bolted Joints under Bending Moment

    Science.gov (United States)

    Naruse, Tomohiro; Shibutani, Yoji

    Equivalent stiffness of plates clamped by bolted joints for designing should be evaluated according to not only the strength of bolted joints but also the deformation and vibration characteristics of the structures. When the applied external axial load or the bending moment is sufficiently small, the contact surfaces of the bolted joint are stuck together, and thus both the bolt and the clamped plates deform linearly. Although the sophisticated VDI 2230 code gives the appropriate stiffness of clamped plates for the infinitesimal deformation, the stiffness may vary nonlinearly with increasing the loading because of changing the contact state. Therefore, the present paper focuses on the nonlinear behaviour of the bending stiffness of clamped plates by using Finite Element (FE) analyses, taking the contact condition on bearing surfaces and between the plates into account. The FE models of the plates with thicknesses of 3.2, 4.5, 6.0 and 9.0 mm tightened with M8, 10, 12 and 16 bolts were constructed. The relation between bending moment and bending compliance of clamped plates is found to be categorized into three regions, namely, (i) constant compliance with fully stuck contact surfaces, (ii) transition showing the nonlinear compliance, and (iii) constant compliance with one-side contact surfaces. The mechanical models for these three regions are proposed and compared with FEM solutions. The prediction on the bounds of three regions is in a fairly good agreement except the case with smaller bolts and thicker plates.

  12. Combined Triplex/Duplex Invasion of Double-Stranded DNA by "Tail-Clamp" Peptide Nucleic Acid

    DEFF Research Database (Denmark)

    Bentin, Thomas; Larsen, H. J.; Nielsen, Peter E.

    2003-01-01

    "Tail-clamp" PNAs composed of a short (hexamer) homopyrimidine triplex forming domain and a (decamer) mixed sequence duplex forming extension have been designed. Tail-clamp PNAs display significantly increased binding to single-stranded DNA compared with PNAs lacking a duplex-forming extension as...... determined by T-m measurements. Binding to double-stranded (ds) DNA occurred by combined triplex and duplex invasion as analyzed by permanganate probing. Furthermore, C-50 measurements revealed that tail-clamp PNAs consistently bound the dsDNA target more efficiently, and kinetics experiments revealed that...... this was due to a dramatically reduced dissociation rate of such complexes. Increasing the PNA net charge also increased binding efficiency, but unexpectedly, this increase was much more pronounced for tailless-clamp PNAs than for tail-clamp PNAs. Finally, shortening the tail-clamp PNA triplex invasion...

  13. Delayed cord clamping in red blood cell alloimmunization: safe, effective, and free?

    Science.gov (United States)

    McAdams, Ryan M

    2016-04-01

    Hemolytic disease of the newborn (HDN), an alloimmune disorder due to maternal and fetal blood type incompatibility, is associated with fetal and neonatal complications related to red blood cell (RBC) hemolysis. After delivery, without placental clearance, neonatal hyperbilirubinemia may develop from ongoing maternal antibody-mediated RBC hemolysis. In cases refractory to intensive phototherapy treatment, exchange transfusions (ET) may be performed to prevent central nervous system damage by reducing circulating bilirubin levels and to replace antibody-coated red blood cells with antigen-negative RBCs. The risks and costs of treating HDN are significant, but appear to be decreased by delayed umbilical cord clamping at birth, a strategy that promotes placental transfusion to the newborn. Compared to immediate cord clamping (ICC), safe and beneficial short-term outcomes have been demonstrated in preterm and term neonates receiving delayed cord clamping (DCC), a practice that may potentially be effective in cases RBC alloimmunization. PMID:27186530

  14. Significance of Shrinkage Induced Clamping Pressure in Fiber-Matrix Bonding in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Stang, Henrik

    1996-01-01

    The present paper accesses the significance of shrinkage inducedclamping pressure in fiber/matrix bonding mechanisms incementitious composite materials. The paper contains a description of an experimental setup whichallows mbox{measurement} of the clamping pressure which develops on anelastic...... inhomogeneity embedded in a matrix consisting of acementitious material undergoing shrinkage during hydration(autogenous shrinkage). Furthermore, the paperpresents the analysis necessary to perform an interpretation of the experimental results and which allows for thedetermination of the clamping pressure...... used in high performance cementitious composite materials.Assuming a Coulomb type of friction on the fiber/matrix interface andusing typical values for the frictional coefficient it is shownthat the shrinkage induced clamping pressure could be one of the mostimportant factors determining the frictional...

  15. Enhancing endogenous stem cells in the newborn via delayed umbilical cord clamping

    Directory of Open Access Journals (Sweden)

    Christopher Lawton

    2015-01-01

    Full Text Available There is currently no consensus among clinicians and scientists over the appropriate or optimal timing for umbilical cord clamping. However, many clinical studies have suggested that delayed cord clamping is associated with various neonatal benefits including increased blood volume, reduced need for blood transfusion, increased cerebral oxygenation in pre-term infants, and decreased frequency of iron deficiency anemia in term infants. Human umbilical cord blood contains significant amounts of stem and progenitor cells and is currently used in the treatment of several life-threatening diseases. We propose that delayed cord clamping be encouraged as it enhances blood flow from the placenta to the neonate, which is accompanied by an increase supply of valuable stem and progenitor cells, as well as may improve blood oxygenation and increase blood volume, altogether reducing the infant′s susceptibility to both neonatal and age-related diseases.

  16. Enhancing endogenous stem cells in the newborn via delayed umbilical cord clamping.

    Science.gov (United States)

    Lawton, Christopher; Acosta, Sandra; Watson, Nate; Gonzales-Portillo, Chiara; Diamandis, Theo; Tajiri, Naoki; Kaneko, Yuji; Sanberg, Paul R; Borlongan, Cesar V

    2015-09-01

    There is currently no consensus among clinicians and scientists over the appropriate or optimal timing for umbilical cord clamping. However, many clinical studies have suggested that delayed cord clamping is associated with various neonatal benefits including increased blood volume, reduced need for blood transfusion, increased cerebral oxygenation in pre-term infants, and decreased frequency of iron deficiency anemia in term infants. Human umbilical cord blood contains significant amounts of stem and progenitor cells and is currently used in the treatment of several life-threatening diseases. We propose that delayed cord clamping be encouraged as it enhances blood flow from the placenta to the neonate, which is accompanied by an increase supply of valuable stem and progenitor cells, as well as may improve blood oxygenation and increase blood volume, altogether reducing the infant's susceptibility to both neonatal and age-related diseases. PMID:26604879

  17. Enhancing endogenous stem cells in the newbornvia delayed umbilical cord clamping

    Institute of Scientific and Technical Information of China (English)

    Christopher Lawton; Sandra Acosta; Nate Watson; Chiara Gonzales-Portillo; hTeo Diamandis; Naoki Tajiri; Yuji Kaneko; Paul R. Sanberg; Cesar V. Borlongan

    2015-01-01

    There is currently no consensus among clinicians and scientists over the appropriate or optimal timing for umbilical cord clamping. However, many clinical studies have suggested that delayed cord clamping is associated with various neonatal beneifts including increased blood volume, reduced need for blood transfusion, increased cerebral oxygenation in pre-term infants, and decreased frequency of iron deifciency anemia in term infants. Human umbilical cord blood con-tains signiifcant amounts of stem and progenitor cells and is currently used in the treatment of several life-threatening diseases. We propose that delayed cord clamping be encouraged as it en-hances blood lfow from the placenta to the neonate, which is accompanied by an increase supply of valuable stem and progenitor cells, as well as may improve blood oxygenation and increase blood volume, altogether reducing the infant’s susceptibility to both neonatal and age-related diseases.

  18. Development of planar patch clamp technology and its application in the analysis of cellular electrophysiology

    Institute of Scientific and Technical Information of China (English)

    Peihua Chen; Wei Zhang; Jun Zhou; Ping Wang; Lidan Xiao; Mo Yang

    2009-01-01

    A patch clamp chip, as a novel cell-based chip for electrophysiological recordings, has many prominent advantages such as high res-olution, accuracy, high throughput and automation. It can be used to perform multivariate and real-time measurements of cell networks in situ. Therefore, this technology will dramatically promote the research on ionic channels, neuronal networks and the application of this technology in drug screening. This paper reviews the development of planar patch clamp technology and its applications in detail. The latest progress in the research of taste cells electrophysiology and taste transduction is also presented. Finally, this paper analyzes the methodology of neural chips. Based on the current research of our laboratory, the prospective applications of a patch clamp chip in the research of taste sensation and transduction mechanisms at molecular and cellular levels are discussed.

  19. Delayed cord clamping for prevention of iron deficiency anemia in term infants

    Directory of Open Access Journals (Sweden)

    Olga Rasiyanti Siregar

    2012-07-01

    Full Text Available Background Iron deficiency anemia (IDA during infancy and childhood is a concern due to its potentially detrimental effects on development, some of which may be irreversible even after iron treatment. Delayed cord clamping may prevent IDA by increasing an infant’s iron reserve at birth. Objective We aimed to evaluate the effect of delayed umbilical cord clamping at birth on the iron status in newborns at age 24 hours of life. Methods This randomized, single-blind study was conducted from March to May 2009, at two general hospitals in Medan, North Sumatera Province. Eligible newborn infants were randomly assigned to one of two groups: early cord clamping (ECC performed 15 seconds after delivery or delayed cord clamping (DCC performed 2 minutes after delivery. Infants were placed on their mothers’ abdomens before the umbilical cords were clamped. Hematologic status was determined from umbilical cord blood. Results Sixty-three subjects were included in our study, consisting of 31 infants in the ECC group and 32 infants in the DCC group. We found that mean neonatal hemoglobin level was higher in the DCC group than in the ECC group (18.4 g% and 16.2 g%, respectively, P=0.0001. Also, mean ferritin level was higher in the DCC group than in the ECC group (556 mg/dL and 329 mg/dL, respectively, P=0.015. Other hematological status indicators, including mean hematocrit and mean corpuscular volume (MCV level, were also higher in the DCC group. However, mean red blood cell levels were not significantly different between the two groups. Nor was there a significant difference in mean bilirubin level between the DCC and ECC groups. Conclusion Delayed cord clamping may improve iron status and prevent IDA in term infants.

  20. Role of the α Clamp in the Protein Translocation Mechanism of Anthrax Toxin.

    Science.gov (United States)

    Brown, Michael J; Thoren, Katie L; Krantz, Bryan A

    2015-10-01

    Membrane-embedded molecular machines are utilized to move water-soluble proteins across these barriers. Anthrax toxin forms one such machine through the self-assembly of its three component proteins--protective antigen (PA), lethal factor, and edema factor. Upon endocytosis into host cells, acidification of the endosome induces PA to form a membrane-inserted channel, which unfolds lethal factor and edema factor and translocates them into the host cytosol. Translocation is driven by the proton motive force, composed of the chemical potential, the proton gradient (ΔpH), and the membrane potential (Δψ). A crystal structure of the lethal toxin core complex revealed an "α clamp" structure that binds to substrate helices nonspecifically. Here, we test the hypothesis that, through the recognition of unfolding helical structure, the α clamp can accelerate the rate of translocation. We produced a synthetic PA mutant in which an α helix was crosslinked into the α clamp to block its function. This synthetic construct impairs translocation by raising a yet uncharacterized translocation barrier shown to be much less force dependent than the known unfolding barrier. We also report that the α clamp more stably binds substrates that can form helices than those, such as polyproline, that cannot. Hence, the α clamp recognizes substrates by a general shape-complementarity mechanism. Substrates that are incapable of forming compact secondary structure (due to the introduction of a polyproline track) are severely deficient for translocation. Therefore, the α clamp and its recognition of helical structure in the translocating substrate play key roles in the molecular mechanism of protein translocation. PMID:26344833

  1. Analysis and testing of the DIII-D ohmic heating coil lead repair clamp

    International Nuclear Information System (INIS)

    DIII-D has been operating for the last year with limited volt-second capabilities due to structural failure of a conductor lead to one of the ohmic heating (OH) solenoids. The conductor failure was due to poor epoxy impregnation of the overwrap of the lead pack, resulting in copper fatigue and a water leak. A number of structural analyses were performed to assist in determining the failure scenario and to evaluate various repair options. A fatigue stress analysis of the leads with a failed epoxy overwrap indicated crack initiation after 1,000 cycles at the maximum operating conditions. The failure occurred in a very inaccessible area which restricted design repair options to concepts which could be implemented remotely. Several design options were considered for repairing the lead so that it can sustain the loads for 7.5 Vs conditions at full toroidal field. A clamp, along with preloaded banding straps and shim bags, provides a system that guarantees that the stress at the crack location is always compressive and prevents further crack growth in the conductor. Due to the limited space available for the repair, it was necessary to design the clamp system to operate at the material yield stress. The primary components of the clamp system were verified by load tests prior to installation. The main body of the clamp contains a load cell and potentiometer for monitoring the load-deflection characteristics of the clamp and conductors during plasma operation. Strain gages provides redundant instrumentation. If required, the preload on the conductors can be increased remotely by a special wrench attached to the clamp assembly

  2. Cracking associated with micrometeoroid impact craters in anodized aluminum alloy clamps on LDEF

    Science.gov (United States)

    Murr, Lawrence E.; Niou, Chorng S.; Quinones, Stella; Murr, Kyle S.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) is a reusable hollow-cylindrical satellite sustaining a total of 57 different experiments. The 130 sq m of spacecraft surface area included anodized 6061-T6 Al alloy bay frames and clamps for holding experiment trays in the bay areas. Attention is presently given to the micrometeoroid impact crater features observed on two tray clamps recovered from the LDEF leading-edge locations. It is found that even very subtle surface modifications in structural alloy anodizing can influence micrometeoroid impact crater cracking, notable radial cracking due to the ejecta-rim of the impact craters.

  3. High pressure clamp for electrical measurements up to 8 GPa and temperature down to 77 K

    Science.gov (United States)

    Bandyopadhyay, A. K.; Nalini, A. V.; Gopal, E. S. R.; Subramanyam, S. V.

    1980-01-01

    A compact clamp-type high pressure cell for carrying out electrical conductivity measurements on small solid samples of size 1 mm or less at pressures upto 8 GPa (i.e., 80 kbar) and for use down to 77 K has been designed and fabricated. The pressure generated in the sample region has been calibrated at room temperature against the polymorphic phase transitions of Bismuth and Ytterbium. The pressure relaxation of the clamp at low temperatures has been estimated by monitoring the electrical conductivity behavior of lead.

  4. In vivo patch clamp recording technique in the study of neurophysiology

    Institute of Scientific and Technical Information of China (English)

    Lan-Wei CUI; Yu-Rong LI

    2006-01-01

    The patch clamp recording technique in vivois a blind patch clamp recording methods to record the current of the spinal or cereral neurons of anaesthesia ( or awake) animals. This technique can be used to study the synaptic function and plasticity in central nervous system in vivoin order to understand the physiological properties of the ion channels from an integrated point of view. The advantage of this technique have already presented itself in the study of the synaptic transmission and nervous network. Nowadays, in vivo patch whole-cell recording technique in combination with other techniques is becoming a common method in the research fields.

  5. Cushing's disease; inferior petrosal sinus venography and samplings

    International Nuclear Information System (INIS)

    Hypersecretion of ACTH in patients with Cushing's syndrome originates from either a pituitary tumor (Cushing's disease) or an ectopic ACTH-secreting tumor. These 2 entities may be clinically indistinguishable, and additional difficulty arise because pituitary microadenomas may be radiologically occult. Recently, bilateral selective venous sampling from the inferior petrosal sinuses became the procedure of choice for confirming a false negative study of a combined hormonal test and pituitary ACTH hypersecretion. We performed selective venous catheterization and sampling for ACTH. The central location of the lesion was detected in 1 case (intersinus gradient = 1.1 : 1), and the remaining 5 cases revealed lateralization of the lesions (intersinus gradient = 3.7 - 20.1 : 1), which correlated well with transsphenoidal microadenomectomies in all the cases. We concluded that selective venous ACTH sampling from the inferior petroal sinus is a reliable and useful aid in the diagnosis of Cushing's disease when standard clinical and biochemical studies are inconclusive

  6. Isolated inferior rectus muscle rupture after blunt orbital trauma

    Science.gov (United States)

    Tomasetti, Patrick; Metzler, Philipp; Jacobsen, Christine

    2013-01-01

    A 44-year-old man was referred to our department with diplopia, periorbital swelling and haematoma of the left eye after orbital trauma due to a punch. During the examination, mild enophthalmos, hypertropia and a total absence of infraduction were observed. An orbital computed tomography (CT) scan demonstrated a left orbital floor blow-out fracture, with caudal herniation of periorbital fat and rectus inferior muscle. Repair was performed under total anaesthesia with placement of a Titan mesh. The following days were marked by the persistence of diplopia without improvement of infraduction. A postoperative, 0.5 mm CT scan highlighted a complete rupture of the inferior rectus muscle, not seen before operation, by a 1.0 mm-sliced CT. In this case, orthoptic therapy was undertaken with good results after 6 months and without need of a second repair. PMID:24963904

  7. Right Ventricular Involvement in either Anterior or Inferior Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Firoozeh Abtahi

    2016-06-01

    Full Text Available Background: Unlike left ventricular function, less attention has been paid to Right Ventricular (RV function after Myocardial Infarction (MI. Objectives: The current study aimed to compare RV function in patients with inferior and anterior MI. Patients and Methods: During the study period, 60 patients consecutively presented to the Emergency Department with chest pain were divided into two groups based on their electrocardiographic findings. Accordingly, 25 patients had inferior MI (IMI group and 35 ones had anterior MI (AMI group. Echocardiography was performed 48 hours after starting the standard therapy. Conventional echocardiographic parameters and Tissue Doppler Imaging (TDI measurements were acquired from the standard views. Student t-test and the chi-square test were respectively used for comparisons of the normally distributed continuous and categorical variables in the two groups. Besides, P < 0.05 was considered to be statistically significant.

  8. Management of the Thrombosed Filter-Bearing Inferior Vena Cava

    OpenAIRE

    Sildiroglu, Onur; Ozer, Harun; Turba, Ulku Cenk

    2012-01-01

    Inferior vena cava (IVC) filter thrombosis is a complex problem. Thrombus within an IVC filter may range from an asymptomatic small thrombus to critical IVC occlusion that affects both lower extremities. The published experience of IVC thrombosis management in relation to filters is either anecdotal or limited to a small group of patients; however, endovascular treatment methods appear to be safe and effective in patients with IVC thrombosis. This review focuses on filter-related IVC thrombos...

  9. Unusual variant of infrarenal duplication of inferior vena cava

    Directory of Open Access Journals (Sweden)

    Ranjan Kumar Sahoo

    2016-01-01

    Full Text Available Infrarenal inferior vena cava (IVC duplication is a rare anomaly. Most of the cases are asymptomatic and are detected incidentally. Prior knowledge of the anomaly is essential for safe procedure by intervention radiologist, retroperitoneal operation, and multi-visceral recovery operation from deceased donor by surgeon. We report a case of infrarenal IVC duplication detected incidentally during contrast-enhanced computed tomography examination of abdomen of a patient presenting with viral hepatitis and mild obstructive jaundice.

  10. Distal posterior inferior cerebellar artery aneurysm in a child

    OpenAIRE

    J. FRANCISCO SALOMÃO; René D. Leibinger; Yara M. S. Lima Ciro de A. Cunha; Ilton G. Shinzato; Paulo de T. L. Dantas

    1992-01-01

    The case of a 7-year-old boy presenting with recurrent episodes of subarachnoid hemorrhage due to a distal posterior inferior cerebellar artery aneurysm (PICA), successfully operated, is reported.' The low incidence of intracranial aneurysms in the first decade of life and the rare occurrence of distal PICA aneurysms are unusual features of this case. The theories regarding the origin of intracranial berry aneurysms are discussed.

  11. Optional inferior vena caval filters: where are we now?

    LENUS (Irish Health Repository)

    Keeling, A N

    2008-08-01

    With the advent of newer optional\\/retrievable inferior vena caval filters, there has been a rise in the number of filters inserted globally. This review article examines the currently available approved optional filter models, outlines the clinical indications for filter insertion and examines the expanding indications. Additionally, the available evidence behind the use of optional filters is reviewed, the issue of anticoagulation is discussed and possible future filter developments are considered.

  12. Asymptomatic Duodenal Perforation from an Inferior Vena Cava Filter

    OpenAIRE

    Park, Jean R.; Oza, Veeral M; Krishna, Somashekar G

    2014-01-01

    Recent exponential increase in inferior vena cava (IVC) filter placements has led to a higher rate of filter complications. A 46-year-old man with a past history of IVC filter placement for bilateral deep vein thrombosis presented with lower abdominal pain. Imaging studies demonstrated IVC filter strut penetrations into multiple structures. Upper endoscopy confirmed an uncomplicated single IVC filter strut penetration into the duodenal wall. The abdominal pain was determined to be unrelated t...

  13. Decompression of inferior alveolar nerve: case report comment

    OpenAIRE

    Ngeow, W. C.

    2011-01-01

    Paresthesia as a result of mechanical trauma is one of the most frequent sensory disturbances of the inferior alveolar nerve. This case report describes surgical treatment for paresthesia caused by a compressive phenomenon within the mandibular canal. The cause of the compression, a broken instrument left in the patient's mouth during previous endodontic therapy, was identified during routine radiography and computed tomography. Once the foreign object was removed by surgery, the paresthesia ...

  14. Coronectomy - A viable alternative to prevent inferior alveolar nerve injury

    Directory of Open Access Journals (Sweden)

    Alok Sagtani

    2015-12-01

    Full Text Available Background and Objectives: Coronectomy is a relatively new method to prevent the risk of Inferior Alveolar Nerve (IAN injury during removal of lower third molars with limited scientific literature among Nepalese patients. Thus, a study was designed to evaluate coronectomy regarding its use, outcomes and complications.Materials and Methods: A descriptive study was conducted from December 2012 to December 2013 among patients attending Department of Oral and Maxillofacial Surgery, College of Dental Sciences, BP Koirala Institute of Health Sciences, Dharan, Nepal for removal of mandibular third molars. After reviewing the radiograph for proximity of third molar to the IAN, coronectomy was advised. A written informed consent was obtained from the patients and coronectomy was performed. Patients were recalled after one week. The outcome measures in the follow-up visit were primary healing, pain, infection, dry socket, root exposure and IAN injury. The prevalence of IAN proximity of lower third molars and incidence of complications were calculated.Results: A total 300 mandibular third molars were extracted in 278 patients during the study period. Out of 300 impacted mandibular third molar, 41 (13.7% showed close proximity to inferior alveolar nerve . The incidence of complications and failed procedure was 7.4% among the patients who underwent coronectomy. During the follow up visit, persistent pain and root exposure was reported while other complications like inferior alveolar nerve injury, dry socket and infection was not experienced by the study patients.Conclusion: With a success rate of 92.6% among the 41 patients, coronectomy is a viable alternative to conventional total extraction for mandibular third molars who have a higher risk for damage to the inferior alveolar nerve.JCMS Nepal. 2015;11(3:1-5.

  15. Myelinated axon counts of human inferior alveolar nerves.

    OpenAIRE

    Heasman, P A; Beynon, A D

    1987-01-01

    A quantitative, postmortem study of 36 human inferior alveolar nerves is described. The total myelinated fibre count (TMFC) of nerves was not related to sex or age of the subjects but significant positive correlations were found between TMFC and subject body weight in both dentate (r = 0.616) and edentulous (r = 0.676) groups. The TMFC was significantly lower in nerves from edentulous subjects than in nerves from dentate subjects.

  16. Two Classes of GABAergic Neurons in the Inferior Colliculus

    OpenAIRE

    Ito, Tetsufumi; Bishop, Deborah C; Oliver, Douglas L.

    2009-01-01

    The inferior colliculus (IC) is unique, having both glutamatergic and GABAergic projections ascending to the thalamus. Although subpopulations of GABAergic neurons in the IC have been proposed, criteria to distinguish them have been elusive and specific types have not been associated with specific neural circuits. Recently, the largest IC neurons were found to be recipients of somatic terminals containing vesicular glutamate transporter 2 (VGLUT2). Here, we show with electron microscopy that ...

  17. Bilateral catheterization of inferior petrosal sinous: Utility in Cushing syndrome

    International Nuclear Information System (INIS)

    The aim of this study is to present our experience on bilateral and simultaneous inferior petrous sinus catheterization, on those patients with ACTH -dependent Cushing's syndrome. We describe the procedure and our results. Material and Method: A retrospective study was held between January 2003 and September 2009, including nine patients (2 men, 7 women) presenting ACTH - dependent Cushing's syndrome. Simultaneous inferior petrosal sinus catheterization was performed in all of them, sampling basal ACTH and after CRH stimulation. ACTH levels gradient in different pituitary locations and peripheral blood levels was recorded. Diagnosis was suggested when inappropriate and maintained hypercortisolemia. High urinary free cortisol levels and no response to dexamethasone suppression were detected. Eight out of nine patients had a prior negative imaging test result. Results: Inferior petrosal sinus bilateral catheterization was successfully performed in all cases, with no evidence of further complications. The results showed definitive diagnosis in all cases. In four patients ACTH levels gradient was lateralized to the left, leading to a specific surgical approach. One patient presented pituitary ACTH - secreting adenoma. Two other patients showed ectopic ACTH production, one showed suprarenal adenoma secreting ACTH and other one showed response to pituitary stimulation without side lateralisation, presenting a histological diagnosis of pituitary hyperplasia. Conclusion: Petrosal sinus catheterization is shown to be an efficient procedure to manage Cushing's syndrome differential diagnosis and to obtain specific anatomical information.

  18. Bilateral inferior dislocation of the hip-a case report

    Directory of Open Access Journals (Sweden)

    Bhagwat Kishan R

    2012-04-01

    Full Text Available 【Abstract】Inferior dislocation of the hip is the ra-rest type in hip dislocation. Very few cases have been re-ported in the anglophonic literature, most of which involved the pediatric age group. Surprisingly, we came across a 30-year-old patient with a bilateral inferior hip dislocation. He had sustained a road traffic accident and the attitude of both hip joints was flexion and abduction. The diagnosis was confirmed by radiographs which revealed the long axis of the femur at an angle of 110 (right degrees and 100 (left degrees respectively away from the axis. Closed reduction under sedation was successfully performed. Skin traction for a period of 6 weeks was advised and the follow-up re-vealed an excellent result. We present the details of this case, the first of its kind along with a review of the literature, discussing the various modes and mechanisms of injury inducing inferior dislocation of the hip. Key words: Hip dislocation; Joints; Femur

  19. Efficacy of Radiofrequency Turbinatoplasty for Treatment of Inferior Turbinate Hypertrophy

    Directory of Open Access Journals (Sweden)

    Nader Saki

    2011-03-01

    Full Text Available Introduction: Nasal inferior turbinate hypertrophy is one of the most common causes of nasal obstruction. Many different surgical methods are currently available. The aim of this study was to review the efficacy and results of radiofrequency turbinatoplasty as a new method in the treatment of the large inferior nasal turbinate. Materials and Methods: This prospective study was conducted on 50 patients with symptoms and signs of nasal obstruction associated with inferior turbinate hypertrophy refractory to medical therapy. The turbinoplasty was performed using the radiofrequency method. Effectiveness of treatment, signs and symptoms before surgery compared to the first week, first and third month after surgery and possible complications were evaluated. Nasal endoscopy and visual analogue scale (VAS were used to assess treatment outcomes at the end of week 1 and months 1 and 3 after surgery. Results: In this study the average age was 24 years old. 27 male (54% and 23 female (46% are included in this study. The etiology was vasomotor rhinitis (28 cases and allergic rhinitis (22 cases. Turbinate edema and secretions decreased significantly (P

  20. Gaining Surgical Access for Repositioning the Inferior Alveolar Neurovascular Bundle

    Directory of Open Access Journals (Sweden)

    Saif Yousif Abdullah Al-Siweedi

    2014-01-01

    Full Text Available This study is aimed at determining anatomical landmarks that can be used to gain access to the inferior alveolar neurovascular (IAN bundle. Scanned CBCT (i-CAT machine data of sixty patients and reconstructions performed using the SimPlant dental implant software were reviewed. Outcome variables were the linear distances of the mandibular canal to the inferior border and the buccal cortex of the mandible, measured immediately at the mental foramen (D1 and at 10, 20, 30, and 40 mm (D2–D5 distal to it. Predictor variables were age, ethnicity, and gender of subjects. Apicobasal assessment of the canal reveals that it is curving downward towards the inferior mandibular border until 20 mm (D3 distal to the mental foramen where it then curves upwards, making an elliptic-arc curve. The mandibular canal also forms a buccolingually oriented elliptic arc in relation to the buccal cortex. Variations due to age, ethnicity, and gender were evident and this study provides an accurate anatomic zone for gaining surgical access to the IAN bundle. The findings indicate that the buccal cortex-IAN distance was greatest at D3. Therefore, sites between D2 and D5 can be used as favorable landmarks to access the IAN bundle with the least complications to the patient.

  1. Increased transvascular escape rate of albumin during experimental portal and hepatic venous hypertension in the pig. Relation to findings in patients with cirrhosis of the liver

    DEFF Research Database (Denmark)

    Henriksen, J H; Parving, H H; Christiansen, Lasse; Winkler, K; Lassen, N A

    1981-01-01

    during regional venous congestion in the infradiaphragmatic area. Balloon catheters were placed in the portal vein (infrahepatic portal congestion) and in the inferior vena cava above (suprahepatic caval congestion) and below (infrahepatic caval congestion) the outlets of the hepatic veins. TERalb was on...... the average 13% IVMalb.h-1 under basal pressure conditions. TERalb rose significantly (p less than 0.01) during suprahepatic caval and infrahepatic portal congestion to an average of 29 and 19% IVMalb.h-1, respectively. TERalb was positively correlated to the portal pressure (r = 0.75, P less than 0.......001). Only a minor increment in TERalb was found during infrahepatic caval congestion. The hepatic share of the increasedTERalb during stasis above the hepatic veins was estimated to be threefold that of the extrahepatic splanchnic area. Our results point to filtration of protein, predominantely through the...

  2. Increased transvascular escape rate of albumin during experimental portal and hepatic venous hypertension in the pig. Relation to findings in patients with cirrhosis of the liver

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Parving, H H; Christiansen, L; Winkler, K; Lassen, N A

    1981-01-01

    during regional venous congestion in the infradiaphragmatic area. Balloon catheters were placed in the portal vein (infrahepatic portal congestion) and in the inferior vena cava above (suprahepatic caval congestion) and below (infrahepatic caval congestion) the outlets of the hepatic veins. TERalb was on...... the average 13% IVMalb.h-1 under basal pressure conditions. TERalb rose significantly (p less than 0.01) during suprahepatic caval and infrahepatic portal congestion to an average of 29 and 19% IVMalb.h-1, respectively. TERalb was positively correlated to the portal pressure (r = 0.75, P less than 0.......001). Only a minor increment in TERalb was found during infrahepatic caval congestion. The hepatic share of the increased TERalb during stasis above the hepatic veins was estimated to be threefold that of the extrahepatic splanchnic area. Our results point to filtration of protein, predominantely through the...

  3. Injury of the Inferior Alveolar Nerve during Implant Placement: a Literature Review

    OpenAIRE

    Gintaras Juodzbalys; Hom-Lay Wang; Gintautas Sabalys

    2011-01-01

    ABSTRACT Objectives The purpose of present article was to review aetiological factors, mechanism, clinical symptoms, and diagnostic methods as well as to create treatment guidelines for the management of inferior alveolar nerve injury during dental implant placement. Material and Methods Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were inferior alveolar nerve injury, inferior alveolar nerve injuries, inferior alveo...

  4. An Unusual Case Of Inferior Turbinate Osteoma Removed Endoscopically: A Case Report.

    Science.gov (United States)

    Prasad, Shyamakant; Kumar, Ashok; Naik, Sulabha M; Kalhan, Shivani

    2016-03-01

    Inferior turbinate osteoma is exceptionally rare. Here we are reporting a case of inferior turbinate osteoma presented with history of left nasal obstruction. CT unveiled osseous hypertrophy of left inferior turbinate. Osteoma was removed endoscopically using hammer and gouge. This is the fourth case to be reported in the world literature and second in India. PMID:27066424

  5. Two-Dimensional Fiber Positioning and Clamping Device for Product-Internal Microassembly

    NARCIS (Netherlands)

    Henneken, V.A.; Sassen, W.P.; Van der Vlist, W.; Wien, W.H.A.; Tichem, M.; Sarro, P.M.

    2008-01-01

    In this paper, we present a microelectromechanical systems-based two-degrees-of-freedom positioning device combined with a clamping structure for positioning and constraining an optical fiber. The fiber position can be controlled in the two directions perpendicular to the fiber axis using two specif

  6. ELECTROCARDIOGRAPHIC RESPONSES OF RAT FETUSES WITH CLAMPED OR INTACT UMBILICAL CORDS TO ACUTE MATERNAL UTERINE ISCHEMIA

    Science.gov (United States)

    Uterine ischemia results in severe cardiac disturbances in the fetus. It has been postulated that these effects are due to interaction with the ischemic uterus or placenta and not due to hypoxia or build up of metabolites in the fetus. The fetal cardiac responses to uterine clamp...

  7. The Response Clamp: Functional characterization of neural systems using closed-loop control

    Directory of Open Access Journals (Sweden)

    Avner Wallach

    2013-01-01

    Full Text Available The voltage clamp method, pioneered by Hodgkin, Huxley and Katz, laid the foundations to neurophysiological research. Its core rationale is the use of closed-loop control as a tool for system characterization. A recently introduced method, the response clamp, extends the voltage clamp rationale to the functional, phenomenological level. The method consists of on-line estimation of a response variable of interest (e.g. the probability of response or its latency and a simple feedback control mechanism designed to tightly converge this variable towards a desired trajectory. In the present contribution I offer a perspective on this novel method and its applications in the broader context of system identification and characterization. First, I demonstrate how internal state variables are exposed using the method, and how the use of several controllers may allow for a detailed, multi-variable characterization of the system. Second, I discuss three different categories of applications of the method: (i exploration of intrinsically generated dynamics, (ii exploration of extrinsically generated dynamics and (iii generation of input-output trajectories. The relation of these categories to similar uses in the voltage clamp and other techniques is also discussed. Finally, I discuss the method’s limitations, as well as its possible synthesis with existing complementary approaches.

  8. Early vs delayed clamping of the umbilical cord in full term, preterm and very preterm infants

    DEFF Research Database (Denmark)

    Moller, N.K.; Weber, T.

    2008-01-01

    Randomized studies from 2006 and two meta-analyses published in 2007 agree that clamping of the umbilical cord can be delayed. For the preterm and very preterm infant benefits include less need for blood transfusion and less morbidity, especially for the very preterm male infant. For the term...

  9. Experimental and numerical analysis of clamped joints in front motorbike suspensions

    Directory of Open Access Journals (Sweden)

    Vincenzi N.

    2010-06-01

    Full Text Available Clamped joints are shaft-hub connections used, as an instance, in front motorbike suspensions to lock the steering plates with the legs and the legs with the wheel pin, by means of one or two bolts. The preloading force, produced during the tightening process, should be evaluated accurately, since it must lock safely the shaft, without overcoming the yielding point of the hub. Firstly, friction coefficients have been evaluated on “ad-hoc designed” specimens, by applying the Design of Experiment approach: the applied tightening torque has been precisely related to the imposed preloading force. Then, the tensile state of clamps have been evaluated both via FEM and by leveraging some design formulae proposed by the Authors as function of the preloading force and of the clamp geometry. Finally, the results have been compared to those given by some strain gauges applied on the tested clamps: the discrepancies between numerical analyses, the design formulae and the experimental results remains under a threshold of 10%.

  10. Two simple finite element methods for Reissner--Mindlin plates with clamped boundary condition

    OpenAIRE

    Bishnu P. Lamichhane

    2013-01-01

    We present two simple finite element methods for the discretization of Reissner--Mindlin plate equations with {\\em clamped} boundary condition. These finite element methods are based on discrete Lagrange multiplier spaces from mortar finite element techniques. We prove optimal a priori error estimates for both methods.

  11. Trans-Z-source and Γ-Z-source neutral-point-clamped inverters

    DEFF Research Database (Denmark)

    Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede;

    2015-01-01

    Z-source neutral-point-clamped (NPC) inverters are earlier proposed for obtaining voltage buck-boost and three-level switching simultaneously. Their performances are, however, constrained by a trade-off between their input-to-output gain and modulation ratio. This trade-off can lead to high...

  12. An Efficient Single Impedance Network Three Level Z-Source Neutral Point Clamped Inverter

    Directory of Open Access Journals (Sweden)

    C.L.Kuppuswamy

    2012-07-01

    Full Text Available A multilevel inverter can eliminate the need for the step-up transformer and reduce the harmonics produced by the inverter. Although the multilevel inverter structure was initially introduced as a means of reducing the output waveform harmonic content, it was found that the dc bus voltage could be increased beyond the voltage rating of an individual power device by the use of a voltage clamping network consisting of diodes. By using voltage clamping techniques, the system KV rating can be extended beyond limits of an individual device. This paper presents Impedance (Z Source Neutral Point Clamped (NPC three level inverter with reduced number of impedance source networks and clamping diodes for non-linear loads. Earlier for a three level NPC inverter two separate impedance networks were used. But to reduce the circuit complexity without compromising with output requirement; only one impedance network is used and to substantiate this, the simulation of proposed circuit is carried out using MATLAB/Simulink for a 48 V input supply. A prototype is developed for an input voltage of 26V and the experimental results for the same are presented in this paper.

  13. A direct proofreader-clamp interaction stabilizes the Pol III replicase in the polymerization mode

    NARCIS (Netherlands)

    Jergic, Slobodan; Horan, Nicholas P.; Elshenawy, Mohamed M.; Mason, Claire E.; Urathamakul, Thitima; Ozawa, Kiyoshi; Robinson, Andrew; Goudsmits, Joris M. H.; Wang, Yao; Pan, Xuefeng; Beck, Jennifer L.; van Oijen, Antoine M.; Huber, Thomas; Hamdan, Samir M.; Dixon, Nicholas E.

    2013-01-01

    Processive DNA synthesis by the alpha epsilon theta core of the Escherichia coli Pol III replicase requires it to be bound to the beta(2) clamp via a site in the a polymerase subunit. How the epsilon proofreading exonuclease subunit influences DNA synthesis by alpha was not previously understood. In

  14. Common voltage eliminating of SVM diode clamping three-level inverter connected to grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong;

    2011-01-01

    A novel method of common voltage eliminating is put forward for SVM diode clamping three-level inverter connected to grid by calculation of common voltage of its various switching states. PLECS is used to model this three-level inverter connected to grid and good results are obtained. First...

  15. Applicability of fiber model in seismic response analysis for center-clamp type bushings on transformers

    International Nuclear Information System (INIS)

    A bushing is a device for insulation and support of a conductor. Especially it is called center-clamp type when it is connected with a metal holder through clamping force. As a consequence of damage of center-clamp type bushings in Tohoku Earthquake in 2011, refinement of the response analysis method and review of the seismic design procedure became necessary. In the present report, the fiber model, which can evaluate non-linear behavior in the section subjected to axial force and bending moment, was implemented to the CRIEPI's finite element analysis program 'Mastrd' considering following characteristics of center-clamp type bushings. a) The gasket section between a porcelain tube and a metal holder has a torus shape. b) Springs around the top of the bushing give clamping force, but they lock in excessive base rotation. c) The gasket does not resist against tension. d) Local resistance against compression due to bending increases in use of very thin gaskets. The developed program was verified through comparison with the shaking table test result for real bushings whose voltage classes were 154 kV and 275 kV. Deformation indices as rotation angle and base opening due to bending were influenced by damping conditions. Though there was not the condition which brought about remarkable underestimation, reduction of damping for a fiber model element was preferable for safety. On the other hand, bending moment was consistent with experimental results because it tended not to fluctuate in the non-linear region. (author)

  16. A Novel Technique for Inferior Vena Cava Filter Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Edward William, E-mail: ed.johnston@doctors.org.uk; Rowe, Luke Michael Morgan; Brookes, Jocelyn; Raja, Jowad; Hague, Julian, E-mail: julian.hague@uclh.nhs.uk [University College Hospital, Multidisciplinary Endovascular Team (United Kingdom)

    2013-05-02

    Inferior vena cava (IVC) filters are used to protect against pulmonary embolism in high-risk patients. Whilst the insertion of retrievable IVC filters is gaining popularity, a proportion of such devices cannot be removed using standard techniques. We describe a novel approach for IVC filter removal that involves snaring the filter superiorly along with the use of flexible forceps or laser devices to dissect the filter struts from the caval wall. This technique has used to successfully treat three patients without complications in whom standard techniques failed.

  17. Retrievable Inferior Vena Cava Filters for Venous Thromboembolism

    International Nuclear Information System (INIS)

    Inferior vena cava (IVC) filters are used as an alternative to anticoagulants for prevention of fatal pulmonary embolism (PE) in venous thromboembolic disorders. Retrievable IVC filters have become an increasingly attractive option due to the long-term risks of permanent filter placement. These devices are shown to be technically feasible in insertion and retrieval percutaneously while providing protection from PE. Nevertheless, there are complications and failed retrievals with these retrievable filters. The aim of the paper is to review the retrievable filters and their efficacy, safety, and retrievability

  18. Inferior Vena Cava Duplication: Incidental Case in a Young Woman.

    Science.gov (United States)

    Coco, Danilo; Cecchini, Sara; Leanza, Silvana; Viola, Massimo; Ricci, Stefano; Campagnacci, Roberto

    2016-01-01

    A case of a double inferior vena cava (IVC) with retroaortic left renal vein, azygos continuation of the IVC, and presence of the hepatic portion of the IVC drained into the right renal vein is reported and the embryologic, clinical, and radiological significance is discussed. The diagnosis is suggested by multidetector computed tomography (MDCT), which reveals the aberrant vascular structures. Awareness of different congenital anomalies of IVC is necessary for radiologists to avoid diagnostic pitfalls and they should be remembered because they can influence several surgical interventions and endovascular procedures. PMID:27217964

  19. Inferior ST-Elevation Myocardial Infarction Associated with Takotsubo Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Oliver Koeth

    2010-01-01

    Full Text Available Takotsubo cardiomyopathy (TCM is usually characterized by transient left ventricular apical ballooning. Due to the clinical symptoms which include chest pain, electrocardiographic changes, and elevated myocardial markers, Takotsubo cardiomyopathy is frequently mimicking ST-elevation myocardial infarction in the absence of a significant coronary artery disease. Otherwise an acute occlusion of the left anterior descending coronary artery can produce a typical Takotsubo contraction pattern. ST-elevation myocardial infarction (STEMI is frequently associated with emotional stress, but to date no cases of STEMI triggering TCM have been reported. We describe a case of a female patient with inferior ST-elevation myocardial infarction complicated by TCM.

  20. Leiomiossarcoma da veia cava inferior: relato de caso

    Directory of Open Access Journals (Sweden)

    Rafael Lemos Nascif

    2014-12-01

    Full Text Available Relatamos um caso de paciente do sexo feminino, 48 anos, com quadro clínico de dor abdominal de moderada intensidade e abaulamento do abdome. Ao exame físico constatou-se massa abdominal palpável. A tomografia computadorizada mostrou volumosa massa retroperitoneal, com realce heterogêneo e íntima relação com a veia cava inferior. Realizou-se ressecção em bloco da massa e do segmento invadido da veia cava. A histologia revelou leiomiossarcoma.

  1. Inferior phrenic artery pseudoaneurysm complicating drug-induced acute pancreatitis.

    Science.gov (United States)

    Salem, Jean F; Haydar, Ali; Hallal, Ali

    2014-01-01

    Inferior phrenic artery (IPA) pseudoaneurysm is an extremely rare complication of chronic pancreatitis with only three cases reported in the literature so far. It is a serious condition that can be life-threatening if not diagnosed promptly. Recent advances in endovascular interventions made angiography with embolisation the modality of choice for diagnosis and treatment. We presented the first report of a case of ruptured IPA pseudoaneurysm complicating a drug-induced acute pancreatitis that was successfully treated by transcatheter arterial embolisation. Despite its rarity, rupture of pseudoaneurysm due to drug-induced pancreatitis should be suspected and included in the differential diagnosis when associated with haemodynamic instability. PMID:24385392

  2. Bruxism elicited by inferior alveolar nerve injury: a case report.

    Science.gov (United States)

    Melis, Marcello; Coiana, Carlo; Secci, Simona

    2012-02-01

    The aim of this case report is to describe the history of a patient who received an injury to the right inferior alveolar nerve after placement of a dental implant, with bruxism noted afterward. The symptoms were managed by the use of an occlusal appliance worn at night and occasionally during the day, associated with increased awareness of parafunction during the day to reduce muscle pain and fatigue. Paresthesia of the teeth, gingiva, and lower lip persisted but were reduced during appliance use. PMID:22254232

  3. Radiological evaluation of inferior vena cava obstruction: pictorial essay

    International Nuclear Information System (INIS)

    The clinical diagnosis of inferior vena cava (IVC) obstruction is often difficult, since patients may present with a multitude of signs and symptoms. The clinical manifestations depend on several factors: the underlying cause, the level of obstruction, the adequacy of collateral circulation, the presence of intercurrent disease, and the organ system involved. Although the most common clinical manifestations are deep venous thrombosis in the legs, abdominal pain, low back pain, loin pain and hematuria, patients may present with unusual and varied pathologic conditions. IVC obstruction may resemble or be associated with such conditions as congestive cardiac failure, cirrhosis of the liver or renal disease. (author)

  4. Liver trauma and transection of the inferior vena cava

    International Nuclear Information System (INIS)

    CT of a child with severe liver trauma due to a seat belt injury demonstrated avulsion of a portion of the lateral segment of the left lobe of the liver. The location of nondependent extravasated contrast material aided in identification of the visceral fracture site (the sentinel contrast sign). Associated transection of the inferior vena cava was evidenced by hypoatenuating zones adjacent to all the major hepatic veins and vena cava (hepatic perivenous tracking). Recognition of these two signs is important so that the radiologist can help the surgeon select the optimal operative approach. (orig.)

  5. Ausência de veia cava inferior: relato de caso Absence of the inferior vena cava: case report

    Directory of Open Access Journals (Sweden)

    Elton Correia Alves

    2010-12-01

    Full Text Available A ausência congênita de veia cava inferior é achado incomum e ocasional durante exames complementares ou cirurgias do abdome. Em razão de a maioria dos pacientes sem outras malformações serem assintomáticos, há dificuldade em estimar a prevalência dessas anomalias. O objetivo deste trabalho foi relatar o caso de um paciente de 28 anos, sexo masculino, referido para radiografia de tórax devido a quadro de febre alta (39ºC não-responsiva à medicação. Radiografia de tórax sugeriu dilatação de veia ázigos. Em inquérito dirigido para sintomas cardiovasculares, referiu dor torácica (durante atividade física e em repouso e dispneia ocasionais durante o sono associada ao período em que intensificou a prática de exercícios. Realizada tomografia computadorizada sem contraste e, posteriormente, contrastada. As mesmas não esclareceram o caso, fazendo-se necessário angiotomografia, a qual evidenciou ausência de veia cava inferior torácica.The congenital absence of the inferior vena cava is a rare and occasional finding at complementary exams or abdominal surgeries. As the majority of patients without other malformations are asymptomatic, it is hard to estimate the prevalence of these anomalies. Our goal was to report a case of a 28-year-old patient, male, referred to thorax X-ray due to high fever state (39ºC, nonresponder to medication. The X-ray suggested azygos vein dilatation. The interview about cardiovascular symptoms revealed thoracic pain during both physical exercises and at rest, and occasional dyspnea during sleep related to the period of intensification of physical exercises. Computadorized tomography with and without contrast did not solve the case, what explain the request of an angiotomography, that showed absence of thoracic inferior vena cava.

  6. Free Vibration Analysis of an Alround-Clamped Rectangular Thin Orthotropic Plate Using Taylor-Mclaurin Shape Function

    Directory of Open Access Journals (Sweden)

    D.O Onwuka

    2016-06-01

    Full Text Available A comprehensive free vibration analysis of an alround-clamped rectangular thin or thotropic plate, was carried out using Taylor- Mclaurin shape function, and Ritz method. The Taylor-Mclaurin shape function truncated at the fourth term satisfied all the boundary conditions of the alround-clamped thin orthotropic plate. The shape function was substituted into the total energy functional, which was subsequently minimized. From the minimized equation, the natural frequency equation for the clamped plate, was derived. The resulting equation was used to calculate fundamental natural frequencies of the clamped plate for various aspect ratios, p and different combinations of flexural rigidity ratios, φ. The fundamental frequencies for a clamped plate vibrating in the first mode are given in Tables1-5, for different flexural rigidities, φ and aspect ratios varying from 0.1 to 2 at increments of 0.1. The average percentage difference in the values of natural frequency for the flexural rigidity ratios, φ1, φ2, and φ3, are 1.532%,1.367% and 1.425% for different values of the aspect ratio, = ; and 1.149%, 1.506% and……..for different values of the aspect ratio, = . These average percentage differences indicate that the formulated deflection function for the clamped plate, is a very good approximation to the exact deflection function of the free vibration of a clamped rectangular thin orthotropic plate

  7. Injury of the Inferior Alveolar Nerve during Implant Placement: a Literature Review

    Directory of Open Access Journals (Sweden)

    Gintaras Juodzbalys

    2011-01-01

    Full Text Available Objectives: The purpose of present article was to review aetiological factors, mechanism, clinical symptoms, and diagnostic methods as well as to create treatment guidelines for the management of inferior alveolar nerve injury during dental implant placement.Material and Methods: Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were inferior alveolar nerve injury, inferior alveolar nerve injuries, inferior alveolar nerve injury implant, inferior alveolar nerve damage, inferior alveolar nerve paresthesia and inferior alveolar nerve repair. The search was restricted to English language articles, published from 1972 to November 2010. Additionally, a manual search in the major anatomy, dental implant, periodontal and oral surgery journals and books were performed. The publications there selected by including clinical, human anatomy and physiology studies.Results: In total 136 literature sources were obtained and reviewed. Aetiological factors of inferior alveolar nerve injury, risk factors, mechanism, clinical sensory nerve examination methods, clinical symptoms and treatment were discussed. Guidelines were created to illustrate the methods used to prevent and manage inferior alveolar nerve injury before or after dental implant placement.Conclusions: The damage of inferior alveolar nerve during the dental implant placement can be a serious complication. Clinician should recognise and exclude aetiological factors leading to nerve injury. Proper presurgery planning, timely diagnosis and treatment are the key to avoid nerve sensory disturbances management.

  8. Comparison between symmetrical and asymmetrical single phase multilevel inverter with diode-clamped topology

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Nami, A.; Zare, F.; Ledwich, G.; Ghosh, A.

    In this paper, a different configuration based on different DC bus voltage for a diode-clamped multilevel inverter has been presented. Two different symmetrical and asymmetrical arrangements of a four-level diode clamped inverters have been compared, in order to find an optimum arrangement with...... lower switching losses and optimised output voltage quality. The optimised asymmetrical arrangement has been compared with a conventional four- level inverter. The comparison results show that an asymmetrical configuration can obtain more voltage levels in output voltage with same number of component...... compared with the conventional four-level inverter and this will lead to the reduction of harmonic content of output voltage. A predictive current control technique has been carried out to verify the viability of new configuration. The advantages of this control method are simplicity and applicability for...

  9. High Efficiency Interleaved Active Clamped Dc-Dc Converter with Fuel Cell for High Voltage Applications

    Directory of Open Access Journals (Sweden)

    Sona P

    2014-02-01

    Full Text Available A high efficiency interleaved ZVS active clamped current fed dc-dc converter is proposed in this paper specially used for fuel cell applications. As the fuel cell output is very low we are in need of a step up dc-dc converter. Here a current fed dc-dc converter is used. Two current fed dc-dc converters are interleaved by connecting their inputs in parallel and outputs in series. With this proposed methodology input current ripples in the fuel cell stacks can be reduced and a regulated output voltage ripples can be obtained. The active clamping circuit used in this model absorbs the turn off voltage spikes hence low voltage devices with low on state resistance can be used.Voltage doubler circuits will give double the output voltage than normal with smaller transformer turns ratio and flexibility. The proposed method is simulated in MATLAB for verifying the accuracy of the proposed design.

  10. Short Hypoxia Does not Affect Plasma Leptin in Healthy Men under Euglycemic Clamp Conditions

    Directory of Open Access Journals (Sweden)

    Andre Schmoller

    2009-01-01

    Full Text Available Leptin is involved in the endocrine control of energy expenditure and body weight regulation. Previous studies emphasize a relationship between hypoxic states and leptin concentrations. The aim of this study was to investigate the effects of acute hypoxia on leptin concentrations in healthy subjects. We examined 14 healthy men. Hypoxic conditions were induced by decreasing oxygen saturation to 75% for 30 minutes. Plasma leptin concentrations were determined at baseline, after 3 hours of euglycemic clamping, during hypoxia, and repeatedly the following 2.5 hours thereafter. Our results show an increase of plasma leptin concentrations in the course of 6 hours of hyperinsulinemic-euglycemic clamping which may reflect diurnal rhythmicity. Notwithstanding, there was no difference between levels of leptin in the hypoxic and the normoxic condition (=.2. Since we did not find any significant changes in leptin responses upon hypoxia, plasma leptin levels do not seem to be affected by short hypoxic episodes of moderate degree.

  11. Membrane tether formation from voltage-clamped outer hair cells using optical tweezers

    Science.gov (United States)

    Qian, Feng; Ermilov, Sergey A.; Murdock, David R.; Brownell, William E.; Anvari, Bahman

    2004-06-01

    Outer hair cells contribute an active mechanical feedback to the vibrations of the cochlear structures resulting in the high sensitivity and frequency selectivity of normal hearing. We have designed and implemented a novel experimental setup that combines optical tweezers with patch-clamp apparatus to investigate the electromechanical properties of cellular plasma membranes. A micron-size bead trapped by the optical tweezers is brought in contact with the membrane of a voltage-clamped cell, and subsequently moved away to form a plasma membrane tether. Bead displacement during tether elongation is monitored by a quadrant photodetector to obtain time-resolved measurements of the tethering force. Salient information associated with the mechanical properties of the membrane tether can thus be obtained. Tethers can be pulled from the cell membrane at different holding potentials, and the tether force response can be measured while changing transmembrane potential. Experimental results from outer hair cells and human embryonic kidney cells are presented.

  12. Detailed Theoretical Model for Adjustable Gain-Clamped Semiconductor Optical Amplifier

    Directory of Open Access Journals (Sweden)

    Lin Liu

    2012-01-01

    Full Text Available The adjustable gain-clamped semiconductor optical amplifier (AGC-SOA uses two SOAs in a ring-cavity topology: one to amplify the signal and the other to control the gain. The device was designed to maximize the output saturated power while adjusting gain to regulate power differences between packets without loss of linearity. This type of subsystem can be used for power equalisation and linear amplification in packet-based dynamic systems such as passive optical networks (PONs. A detailed theoretical model is presented in this paper to simulate the operation of the AGC-SOA, which gives a better understanding of the underlying gain clamping mechanics. Simulations and comparisons with steady-state and dynamic gain modulation experimental performance are given which validate the model.

  13. Simplified Estimating Method for Shock Response Spectrum Envelope of V-Band Clamp Separation Shock

    Science.gov (United States)

    Iwasa, Takashi; Shi, Qinzhong

    A simplified estimating method for the Shock Response Spectrum (SRS) envelope at the spacecraft interface near the V-band clamp separation device has been established. This simplified method is based on the pyroshock analysis method with a single degree of freedom (D.O.F) model proposed in our previous paper. The parameters required in the estimating method are only geometrical information of the interface and a tension of the V-band clamp. According to the use of these parameters, a simplified calculation of the SRS magnitude at the knee frequency is newly proposed. By comparing the estimation results with actual pyroshock test results, it was verified that the SRS envelope estimated with the simplified method appropriately covered the pyroshock test data of the actual space satellite systems except some specific high frequency responses.

  14. Study of transmembrane La3+ movement in rat ventricular myocytes by the patch-clamp technique

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1μmol/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currentsincrease with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.

  15. Experimental validation of new mathematical solutions for orthotropic plates with clamped edges

    Science.gov (United States)

    Sprinťu, Iuliana; Roateşi, Simona

    2013-10-01

    This paper deals with analytical solutions for the bending deformation of rectangular orthotropic elastic composite plates with various boundary conditions. The models are based on the classical laminated plate theory (CLPT). The Ritz method, in conjunction with the weighted residue method for the coefficients calculation is used to analytically determine the bending solutions of orthotropic laminated plates subjected to uniform pressure on the bottom laminate, having clamped edges or possessing two opposite edges simply supported and the remaining two edges clamped, respectively. Numerical examples of laminated plates considering similar boundary value problems as treated analytically are presented. It is presented the experimental device and the experimental test results, as well. Thorough comparison between analytical solutions, numerical results and experimental data is performed and a good agreement is obtained.

  16. Anthropomorphizing the Mouse Cardiac Action Potential via a Novel Dynamic Clamp Method

    Science.gov (United States)

    Ahrens-Nicklas, Rebecca C.; Christini, David J.

    2009-01-01

    Abstract Interspecies differences can limit the translational value of excitable cells isolated from model organisms. It can be difficult to extrapolate from a drug- or mutation-induced phenotype in mice to human pathophysiology because mouse and human cardiac electrodynamics differ greatly. We present a hybrid computational-experimental technique, the cell-type transforming clamp, which is designed to overcome such differences by using a calculated compensatory current to convert the macroscopic electrical behavior of an isolated cell into that of a different cell type. We demonstrate the technique's utility by evaluating drug arrhythmogenicity in murine cardiomyocytes that are transformed to behave like human myocytes. Whereas we use the cell-type transforming clamp in this work to convert between mouse and human electrodynamics, the technique could be adapted to convert between the action potential morphologies of any two cell types of interest. PMID:19917221

  17. Duration of Cord Clamping and Neonatal Outcomes in Very Preterm Infants.

    Directory of Open Access Journals (Sweden)

    Dongli Song

    Full Text Available Delayed cord clamping (DCC, ≥30 s increases blood volume in newborns and is associated with fewer blood transfusions and short-term neonatal complications. The optimal timing of cord clamping for very preterm infants should maximize placental transfusion without interfering with stabilization and resuscitation.We compared the effect of different durations of DCC, 30-45 s vs. 60-75 s, on delivery room (DR and neonatal outcomes in preterm infants 48 hours of antenatal steroid exposure. There was no difference between the two groups in neonatal death, intraventricular hemorrhage, chronic lung disease, late onset sepsis, necrotizing enterocolitis and severe retinopathy of prematurity.In this study cohort increasing DCC duration from 30-45 s to 60-75 s is associated with decreased hypothermia on admission, neonatal respiratory interventions and red blood cell transfusions without increase in neonatal mortality and morbidities.

  18. The effect of adrenergic β2 receptor agonist on paraplegia following clamping of abdominal aorta

    OpenAIRE

    Lee, Bok Y.; Al-Waili, Noori; Butler, Glenn

    2011-01-01

    Introduction Surgical repair of an aortic aneurysm might be complicated by spinal cord injury and paraplegia. Since β-adrenoreceptor agonists showed neuroprotective effects, the study was designed to investigate the effect of clenbuterol on post-aortic clamping paraplegia and to identify if there is hyperemia associated with paraplegia. Material and methods Material and methods: Thirty rabbits were divided into two groups: 15 control and 15 experimental (given clenbuterol 9 mg in drinking wat...

  19. Ionic diffusion in voltage-clamped isolated cardiac myocytes. Implications for Na,K-pump studies.

    OpenAIRE

    Mogul, D J; Singer, D H; ten Eick, R E

    1989-01-01

    The whole-cell voltage-clamp technique employing electrolyte-filled micro-pipette suction electrodes is widely used to investigate questions requiring an electrophysiological approach. With this technique, the ionic composition of the cytosol is assumed to be strongly influenced (as result of diffusion) by the ionic composition of the solution contained in the electrode. If this assumption is valid for isolated cardiac myocytes, the technique would be particularly powerful for studying the de...

  20. Evidence for cooperativity between nicotinic acetylcholine receptors in patch clamp records.

    OpenAIRE

    Keleshian, A M; Edeson, R. O.; G.J. Liu; Madsen, B W

    2000-01-01

    It is often assumed that ion channels in cell membrane patches gate independently. However, in the present study nicotinic receptor patch clamp data obtained in cell-attached mode from embryonic chick myotubes suggest that the distribution of steady-state probabilities for conductance multiples arising from concurrent channel openings may not be binomial. In patches where up to four active channels were observed, the probabilities of two or more concurrent openings were greater than expected,...

  1. Direct Tensile Strength of Steel Fiber Reinforced Concrete by Using Clamping Grips

    OpenAIRE

    ISHIGURO, Satoru; NAKAYA, Mitsuo

    1985-01-01

    This report presents the tensile strength behavior of steel fiber reinforced concrete (SFRC). In this experimental work, direct tensile test by using clamping grips is carried out for the prismatic mortar and concrete specimens reinforced with steel fibers. The volume content of steel fibers varies from 1.0 percent to 2.0 percent of the concrete volume. Test results for different fiber content, fiber length, and specimen size are presented. The results are compared with the results of indirec...

  2. A clinical comparative analysis of crush/clamp, stapler, and dissecting sealer hepatic transection methods1

    OpenAIRE

    Castaldo, Eric T.; Earl, T. Mark; Chari, Ravi S.; Gorden, D. Lee; Merchant, Nipun B; Wright, J. Kelly; Feurer, Irene D; Pinson, C Wright

    2008-01-01

    Introduction. Several methods for hepatic parenchymal division exist. The primary aim was to assess differences in postoperative bile leaks, operative blood loss, and margin status between three transection methods: crush/clamp (CC), stapler (SP), or dissecting sealer (DS). Methods. A single institution, retrospective cohort study was performed on data collected over a three-year period in patients undergoing elective liver resection using the CC, SP, or DS. Patients were excluded if multiple...

  3. Visual patch clamp recording of neurons in thick portions of the adult spinal cord

    DEFF Research Database (Denmark)

    Munch, Anders Sonne; Smith, Morten; Moldovan, Mihai; Perrier, Jean-Francois Marie

    2010-01-01

    enlargement of the spinal cord. With a conventional upright microscope in which the light condenser was carefully adjusted, we could visualize neurons present at the surface of the slice and record them with the whole-cell patch clamp technique. We show that neurons present in the middle of the preparation...... currents (IPSCs) remains constant. These preliminary data suggest that inhibitory and excitatory synaptic connections are balanced locally while excitation dominates long-range connections in the spinal cord....

  4. Study of hepatocellular function in the murine model following hepatic artery selective clamping

    OpenAIRE

    Tralhão, JG; Abrantes, AM; Gonçalves, AC; Hoti, E.; Laranjo, M; Martins, R.; Oliveiros, B.; Cardoso, D; Sarmento-Ribeiro, AB; Botelho, MF; Castro e Sousa, F

    2013-01-01

    PURPOSE: To investigate the impact of selective hepatic artery clamping (SHAC) in hepatocellular function. METHODS: Three groups of Wistar male rats were subjected to SHAC ischemia period of 60min: Group A continuous SHAC were subjected to SHAC ischemia period of 60min, Group B intermittent SHAC of 30min with 5min of reperfusion and Group C intermittent SHAC of 15min with 5min of reperfusion. Animals without SHAC were included-Group D. To evaluate hepatocellular function blood marker...

  5. Resolution of DNA molecules greater than 5 megabases by contour-clamped homogeneous electric fields.

    OpenAIRE

    Vollrath, D; Davis, R.W.

    1987-01-01

    Excellent resolution of chromosomal DNA molecules from Saccharomyces cerevisiae, Candida albicans and Schizosaccharomyces pombe has been obtained using alternating contour-clamped homogeneous electric field (CHEF) gel electrophoresis. The largest of these molecules is greater than 5 Mb in size and is resolved after 130 hours in a 0.6% agarose gel at a field strength of 1.3 V/cm and a switching interval of 1 hour. Separation of concatamers of phage lambda DNA reveals four regions of resolution...

  6. High Speed On-Off Valve Self-adapting Clamping System

    OpenAIRE

    Bing Wang

    2014-01-01

    The high-speed switch electromagnetic valve was a new type of element in the electro-hydraulic control system. The study aimed at the functional requirements and technical specifications of the turbine governor system for high speed on-off valve, designed the new Pulse Width Modulation high speed on-off valve. The high speed on-off valve could control fixture clamping force. Through the analysis of the working characteristics of the hydraulic actuator and h...

  7. Development of a computer interface for a clamp-on ultrasonic flow meter

    OpenAIRE

    Sundin, Peter

    2007-01-01

    The section for volume, flow and temperature at SP Technical Research Institute of Sweden performs measurements of volume, flow and temperature in liquids. Flow meters are best calibrated in its installation to take sources of error like installation effects and the medium into account. If this can be done without having to place measurement equipment inside the pipe it will mean several practical benefits. Since many years, clamp-on ultrasonic flow meters have been available on the market. B...

  8. Higher Accurate Estimation of Axial and Bending Stiffnesses of Plates Clamped by Bolts

    Science.gov (United States)

    Naruse, Tomohiro; Shibutani, Yoji

    Equivalent stiffness of clamped plates should be prescribed not only to evaluate the strength of bolted joints by the scheme of “joint diagram” but also to make structural analyses for practical structures with many bolted joints. We estimated the axial stiffness and bending stiffness of clamped plates by using Finite Element (FE) analyses while taking the contact condition on bearing surfaces and between the plates into account. The FE models were constructed for bolted joints tightened with M8, 10, 12 and 16 bolts and plate thicknesses of 3.2, 4.5, 6.0 and 9.0 mm, and the axial and bending compliances were precisely evaluated. These compliances of clamped plates were compared with those from VDI 2230 (2003) code, in which the equivalent conical compressive stress field in the plate has been assumed. The code gives larger axial stiffness for 11% and larger bending stiffness for 22%, and it cannot apply to the clamped plates with different thickness. Thus the code shall give lower bolt stress (unsafe estimation). We modified the vertical angle tangent, tanφ, of the equivalent conical by adding a term of the logarithm of thickness ratio t1/t2 and by fitting to the analysis results. The modified tanφ can estimate the axial compliance with the error from -1.5% to 6.8% and the bending compliance with the error from -6.5% to 10%. Furthermore, the modified tanφ can take the thickness difference into consideration.

  9. A helping clamp for thoracoscopic plication of eventration of the diaphragm

    OpenAIRE

    Reju Joseph Thomas; Ravi Kishore; Sundeep Kisku

    2011-01-01

    Background and Aim: It is difficult to suture an extremely thin and billowed up congenital eventration of the diaphragm thoracoscopically, without insufflation. Materials and Methods: The authors describe their technique using an intestinal clamp to control the redundant tissue and a feeding tube as a flexible knot pusher, to perform the thoracoscopic plication without risking hypercapnia. Results: A satisfactory result was obtained in all the four children. Conclusion: This is a useful adjun...

  10. A helping clamp for thoracoscopic plication of eventration of the diaphragm

    Directory of Open Access Journals (Sweden)

    Reju Joseph Thomas

    2011-01-01

    Full Text Available Background and Aim: It is difficult to suture an extremely thin and billowed up congenital eventration of the diaphragm thoracoscopically, without insufflation. Materials and Methods: The authors describe their technique using an intestinal clamp to control the redundant tissue and a feeding tube as a flexible knot pusher, to perform the thoracoscopic plication without risking hypercapnia. Results: A satisfactory result was obtained in all the four children. Conclusion: This is a useful adjunctive for thoracoscopic plication of diaphragmatic eventration.

  11. Prediction of numerical distortion after welding with various welding sequences and clampings

    OpenAIRE

    S. Kastelic; J. Medved; Mrvar, P.

    2010-01-01

    Welding simulation of a test cover for hydropower plant was made due to very large dimensions of the cover. The main aim was to predict distortion after welding in order to avoid machining the cover. Welding process was simulated with the Sysweld program to keep distortion in desired limits. Various welding sequences and clamping conditions were calculated to reduce the distortion. Calculation of microstructure constituents in virtual complex geometry of joints was also analyzed.

  12. Efficient Power Conversion in Common Active Clamp for Interleaved Dc-Dc Boost

    Directory of Open Access Journals (Sweden)

    V. Rathinavel Subramaniam

    2014-10-01

    Full Text Available This project presents a high-efficiency and high-step-up non isolated interleaved dc to dc converter with a common active-clamp circuit. In the presented converter, the coupled-inductor boost converters are interleaved. A boost converter is used to clamp the voltage stresses of all the switches in the interleaved converters, caused by the leakage inductances present in the practical coupled inductors, to a low voltage level. The leakage energies of the inter-leaved converters are collected in a clamp capacitor and recycled to the output by the clamp boost converter. The proposed converter achieves high efficiency because of the recycling of the leakage energies, reduction of the switch voltage stress, mitigation of the output diode is reverse recovery problem, and interleaving of the converters. In many applications, high-efficiency, high-voltage step-up dc–dc converters are required as an interface between the available low voltage sources and the output loads, which are operated at much higher voltages. Examples of such applications are as follows. Different distributed energy storage components such as batteries, fuel cells, and ultra capacitors are used in the power trains of hybrid electric vehicles (HEV, electric vehicles (EV, and fuel cell vehicles (FCV. In the present power train architectures of these vehicles, the voltage levels of the energy storage elements are usually low; whereas the motors of the vehicles are driven at much higher voltages. The telecom and the computer industry utilize the standard batteries, with low voltage levels, as a back-up power source. The dc–dc converter, used in this case, is required to boost the low-input voltage of the batteries to the high voltage of the dc bus. Another example is the automotive headlamps, using the high-intensity discharge lamp ballasts..

  13. A Color LED Driver Implemented by the Active Clamp Forward Converter

    OpenAIRE

    C. H. Chang; Cheng, H L; C. A. Cheng; E. C. Chang

    2013-01-01

    Because light emitting diodes (LEDs) have the advantages of dc working voltage, high luminescent efficiency, shortignition time, high reliability and pollution free, they have substituted for incandescent bulbs and fluorescent lampsgradually. In order to simplify circuit complexity, an active clamp forward converter with the sequential color display(SCD) control is proposed to drive red, green and blue (RGB) LED arrays. The proposed converter has zero-voltageswitching (ZVS) operations of both...

  14. Photoluminescence clamping with few excitons in a single-walled carbon nanotube

    OpenAIRE

    Xiao, Y. -F.; Nhan, T. Q.; Wilson, M. W. B.; Fraser, J. M.

    2009-01-01

    Single air-suspended carbon nanotubes (length 2 - 5 microns) exhibit high optical quantum efficiency (7 - 20%) for resonant pumping at low intensities. Under ultrafast excitation, the photoluminescence dramatically saturates for very low injected exciton numbers (2 to 6 excitons per pulse per SWCNT). This PL clamping is attributed to highly efficient exciton-exciton annihilation over micron length scales. Stochastic modeling of exciton dynamics and femtosecond excitation correlation spectrosc...

  15. What we talk about when we talk about capacitance measured with the voltage-clamp step method

    OpenAIRE

    Taylor, Adam L.

    2011-01-01

    Capacitance is a fundamental neuronal property. One common way to measure capacitance is to deliver a small voltage-clamp step that is long enough for the clamp current to come to steady state, and then to divide the integrated transient charge by the voltage-clamp step size. In an isopotential neuron, this method is known to measure the total cell capacitance. However, in a cell that is not isopotential, this measures only a fraction of the total capacitance. This has generally been thought ...

  16. A capacitor-clamped inverter based torsional oscillation damping method for electromechanical drivetrains

    Directory of Open Access Journals (Sweden)

    Shagar Viknash

    2016-01-01

    Full Text Available A typical electromechanical drivetrain consists of an electric motor, connecting shafts and gears. Premature failures of these shafts and gears have been reported which are mainly due to fatigue caused by extreme loads and torsional oscillations. Overdesign and passive damping are the common approaches taken to increase the fatigue life. Nevertheless, they increase the system cost, weight and volume. Alternatively, active damping through advanced inverter control of the motor drive has been identified as a promising solution that does not require overdesign or alterations to the existing system. Even with the active damping control, oscillations propagate into the dc side of the power converter and subsequently to the upstream power bus. Generally, a large capacitor or an additional energy storage system is placed to suppress these oscillations. This paper proposes to use the clamping capacitors of the capacitor-clamped inverter as energy storage elements and thereby eliminate the need for a large dc side capacitor or an additional energy storage system. The efficacy of the proposed method has been verified with computer simulations. Simulation results show that the clamping capacitors are capable of containing torsional oscillations within the inverter without passing them to the upstream power bus.

  17. An ANN Based Capicitor Voltage Balancing Method For Neutral Point Clamped Multi-Level Inverter

    Directory of Open Access Journals (Sweden)

    P.J.S. Praveen,

    2015-11-01

    Full Text Available Multi-level inverters are became popular for usage in medium voltage, low voltage power applications due to flexibility in control and better performance characteristics in terms of harmonic regulation. Neutral point clamped are popular as they require less number of sources as their input when compared with their counter parts i.e. cascaded multi-level inverters and found to be reliable when compared with flying capacitor based multi-level inverters. But when neutral clamped technologies are used for generation of three-phase voltages, the capacitors that are connected at input side experiences imbalance in their voltages, this makes neutral point clamped multi-level inverters less reliable. In the proposed work an attempt is made to study circuits that balances the capacitor voltages and a scheme is investigated for balancing the capacitor voltages. Method proposed in [1] uses PID controller for balancing the capacitor voltages. In this project PI based control scheme and artificial neural network (ANN based control scheme for the front end circuit shown in [1] are designed for achieving balance among the capacitor voltages. The proposed control scheme is simulated with the help of Simpowersystems block set and neural network toolbox of MATLAB software for different load conditions. Results obtained from ANN based controller and PI controller are presented.

  18. Desktop Software for Patch-Clamp Raw Binary Data Conversion and Preprocessing

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2011-01-01

    Full Text Available Since raw data recorded by patch-clamp systems are always stored in binary format, electrophysiologists may experience difficulties with patch clamp data preprocessing especially when they want to analyze by custom-designed algorithms. In this study, we present desktop software, called PCDReader, which could be an effective and convenient solution for patch clamp data preprocessing for daily laboratory use. We designed a novel class module, called clsPulseData, to directly read the raw data along with the parameters recorded from HEKA instruments without any other program support. By a graphical user interface, raw binary data files can be converted into several kinds of ASCII text files for further analysis, with several preprocessing options. And the parameters can also be viewed, modified and exported into ASCII files by a user-friendly Explorer style window. The real-time data loading technique and optimized memory management programming makes PCDReader a fast and efficient tool. The compiled software along with the source code of the clsPulseData class module is freely available to academic and nonprofit users.

  19. A phage-encoded inhibitor of Escherichia coli DNA replication targets the DNA polymerase clamp loader.

    Science.gov (United States)

    Yano, Sho T; Rothman-Denes, Lucia B

    2011-03-01

    Coliphage N4 infection leads to shut-off of host DNA replication without inhibition of host transcription or translation. We report the identification and characterization of gp8, the N4 gene product responsible for this phenotype. N4 gp8 is an Escherichia coli bacteriostatic inhibitor that colocalizes with the E. coli replisome in a replication-dependent manner. Gp8 was purified and observed to cross-link to complexes containing the replicative DNA polymerase, DNAP III, in vivo. Purified gp8 inhibits DNA polymerization by DNA polymerase III holoenzyme in vitro by interfering with polymerase processivity. Gp8 specifically inhibits the clamp-loading activity of DNAP III by targeting the delta subunit of the DNAP III clamp loader; E. coli mutations conferring gp8 resistance were identified in the holA gene, encoding delta. Delta and gp8 interact in vitro; no interaction was detected between gp8 inactive mutants and wild-type delta or between delta gp8-resistant mutants and wild-type gp8. Therefore, this work identifies the DNAP III clamp loader as a new target for inhibition of bacterial growth. Finally, we show that gp8 is not essential in N4 development under laboratory conditions, but its activity contributes to phage yield. PMID:21205014

  20. Molecular jamming--the cystine slipknot mechanical clamp in all-atom simulations.

    Science.gov (United States)

    Pepłowski, Lukasz; Sikora, Mateusz; Nowak, Wiesław; Cieplak, Marek

    2011-02-28

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e., by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement with previous studies within a coarse grained structure based model, the level of resistance is found to be substantially higher than in proteins in which the mechanical clamp operates through shear. The large stretching forces arise through formation of the cystine slipknot mechanical clamp and the resulting steric jamming. We elucidate the workings of such a clamp in an atomic detail. We also study the behavior of five top strength proteins with the shear-based mechanostability in which no jamming is involved. We show that in the atomic model, the jamming state is relieved by moving one amino acid at a time and there is a choice in the selection of the amino acid that advances the first. In contrast, the coarse grained model also allows for a simultaneous passage of two amino acids. PMID:21361557

  1. Molecular jamming—The cystine slipknot mechanical clamp in all-atom simulations

    Science.gov (United States)

    Pepłowski, Łukasz; Sikora, Mateusz; Nowak, Wiesław; Cieplak, Marek

    2011-02-01

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e., by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement with previous studies within a coarse grained structure based model, the level of resistance is found to be substantially higher than in proteins in which the mechanical clamp operates through shear. The large stretching forces arise through formation of the cystine slipknot mechanical clamp and the resulting steric jamming. We elucidate the workings of such a clamp in an atomic detail. We also study the behavior of five top strength proteins with the shear-based mechanostability in which no jamming is involved. We show that in the atomic model, the jamming state is relieved by moving one amino acid at a time and there is a choice in the selection of the amino acid that advances the first. In contrast, the coarse grained model also allows for a simultaneous passage of two amino acids.

  2. Is Near-Infrared Spectroscopy a Reliable Method to Evaluate Clamping Ischemia during Carotid Surgery?

    Directory of Open Access Journals (Sweden)

    Luciano Pedrini

    2012-01-01

    Full Text Available Guidelines do not include cerebral oximetry among monitoring for carotid endarterectomy (CEA. The purpose of this study was to evaluate the reliability of near-infrared spectroscopy (NIRS in the detection of clamping ischemia and in the prevention of clamping-related neurologic deficits using, as a cutoff for shunting, a 20% regional cerebral oxygen saturation (rSO2 decrease if persistent more than 4 minutes, otherwise a 25% rSO2 decrease. Bilateral rSO2 was monitored continuously in patients undergoing CEA under general anesthesia (GA. Data was recorded after clamping, declamping, during shunting and lowest values achieved. Preoperative neurologic, CT-scan, and vascular lesions were recorded. We reviewed 473 cases: 305 males (64.5% mean age 73.3±7.3. Three patients presented transient ischemic deficits at awakening, no perioperative stroke or death; 41 (8.7% required shunting: 30 based on the initial rSO2 value and 11 due to a decrease during surgery. Using the ROC curve analysis we found, for a >25% reduction from baseline value, a sensitivity of 100% and a specificity of 90.6%. Reliability, PPV, and NPV were 95.38%, 9%, and 100%, respectively. In conclusion, this study indicates the potential reliability of NIRS monitoring during CEA under GA, using a cutoff of 25% or a cutoff of 20% for prolonged hypoperfusion.

  3. Three Level Diode Clamped Inverter Fed Induction Motor with Dtc-Svm

    Directory of Open Access Journals (Sweden)

    V. Ranjith Kumar

    2013-09-01

    Full Text Available This project presents a three-level diode-clamped inverter feeding an asynchronous motor drive with direct torque control (DTC. The control method is based on DTC operating principles. The stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a diode-clamped inverter, where each phase of the inverter can be implemented using a dc source, which would be available from fuel cells, batteries, or ultra capacitors. This inverter provides nearly sinusoidal voltages with very low distortion, even without filtering, using fewer switching devices. In addition, the multilevel inverter can generate a high and fixed switching frequency output voltage with fewer switching losses, since only the small power cells of the inverter operate at a high switching rate. Therefore, a high performance and also efficient torque and flux controllers are obtained, enabling a DTC solution for multilevel-inverter-powered motor drives. The Pulse Width modulation technique for an inverter permits to obtain three phase system voltages, which can be applied to the controlled output. Space Vector Modulation (SVPWM principle differs from other PWM processes in the fact that all three drive signals for the inverter will be created simultaneously. The implementation of SVPWM process in digital systems necessitates less operation time and also less program memory. This project uses SVPWM technique for generation of pulses for three-level diode clamped inverter. Simulation is carried out on MATLAB-Simulink software.

  4. Endovascular treatment of the posterior inferior cerebellar artery aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Bradac, G.B.; Bergui, M. [Neuroradiology, Univ. di Torino, Turin (Italy)

    2004-12-01

    Aneurysms may arise at various locations along the course of the posterior inferior cerebellar artery. Brainstem and cranial nerves manipulation make the surgical approach to proximal aneurysms difficult, while the occlusion of the parent vessel is sometimes unavoidable in peripheral aneurysms. Endovascular treatment can be a good alternative, but also with this approach the location of the aneurysm is critical. If occlusion of the parent vessel is planned, anatomical variations and vascular territories of the brainstem should be considered. We report our experience with 18 consecutive aneurysms (12 proximal, 6 peripheral) treated by coils. Complete occlusion was achieved in 14 patients and subtotal in 4. In three patients the parent vessel had to be sacrificed. During treatment two perforations occurred; aneurysms were completely occluded without clinical consequences. Two small asymptomatic cerebellar infarctions were seen on postoperative computed tomography. Clinical outcome was good in 16 patients. (orig.)

  5. [Acute inferior myocardial infarction after injection of etofenamate].

    Science.gov (United States)

    Tekin, Yusuf Kenan; Tekin, Gülaçan

    2012-12-01

    Allergic symptoms accompanied by myocardial ischemic symptoms are defined as Kounis syndrome. Etofenamate is a safe and effective non-steroidal antiinflammatory drug that has widespread utilization. We hereby present a 71-year-old man with Kounis syndrome. Following intramuscular 1 g etofenamate injection, the clinical presentation when admitted to the emergency department (ED) was erythematous rash, pruritus, nausea and vomiting, dizziness, diaphoresis, and chest pain resulting in cardiopulmonary arrest. After 10 minutes of successful cardiopulmonary resuscitation, the electrocardiogram revealed acute inferior myocardial infarction. Patients who admit to the ED with allergic symptoms accompanied by chest pain should consider Kounis syndrome for prompt management. Electrocardiographic examination should be an essential part of the initial evaluation in such patients. PMID:23518891

  6. Anatomy and radiology of the anterior inferior cerebellar artery

    International Nuclear Information System (INIS)

    This study describes the variations of the Anterior Inferior Cerebellar Artery (AICA) and identifies its types of appearance in normal angiograms as well as in angiograms of patients suffering from posterior fossa tumours or from ischemic lesions in the vertebro-basilar territory. For this purpose a study of 20 normal specimens was undertaken. Four main types of the AICA are distinguished. One hundred normal vertebral angiograms, made between 1976 and 1982 in the Valeriuskliniek and the Academisch Ziekenhuis der Vrije Univesiteit are reviewed. The AICA's are classified in the same way as in the anatomical study. The same classification was used in the analysis of 41 vertebral angiograms of patients with posterior fossa tumours and nine angiograms of patients with ischemic disturbances in the posterior cranial fossa. (Auth.)

  7. Frustrative reward omission increases aggressive behaviour of inferior fighters

    DEFF Research Database (Denmark)

    Vindas, Marco A.; Johansen, Ida B.; Vela-Avitua, Sergio;

    2014-01-01

    Animals use aggressive behaviour to gain access to resources, and individuals adjust their behaviour relative to resource value and own resource holding potential (RHP). Normally, smaller individuals have inferior fighting abilities compared with larger conspecifics. Affective and cognitive...... to associate a light with reward. Thereafter, the reward was omitted for half of the fish prior to a contest between individuals possessing a 36–40% difference in RHP. Small control individuals displayed submissive behaviour and virtually no aggression. By contrast, small OER individuals were more...... aggressive, and twoout of 11 became socially dominant. Increased aggression insmall OER individuals was accompanied by increased serotonin levels in the dorsomedial pallium (proposed amygdala homologue), but no changes in limbic dopamine neurochemistry were observed in OER-exposed individuals. The...

  8. Experimental determination of optimal clamping torque for AB-PEM Fuel cell

    Directory of Open Access Journals (Sweden)

    Noor Ul Hassan

    2016-04-01

    Full Text Available Polymer electrolyte Membrane (PEM fuel cell is an electrochemical device producing electricity by the reaction of hydrogen and oxygen without combustion. PEM fuel cell stack is provided with an appropriate clamping torque to prevent leakage of reactant gases and to minimize the contact resistance between gas diffusion media (GDL and bipolar plates. GDL porous structure and gas permeability is directly affected by the compaction pressure which, consequently, drastically change the fuel cell performance. Various efforts were made to determine the optimal compaction pressure and pressure distributions through simulations and experimentation. Lower compaction pressure results in increase of contact resistance and also chances of leakage. On the other hand, higher compaction pressure decreases the contact resistance but also narrows down the diffusion path for mass transfer from gas channels to the catalyst layers, consequently, lowering cell performance. The optimal cell performance is related to the gasket thickness and compression pressure on GDL. Every stack has a unique assembly pressure due to differences in fuel cell components material and stack design. Therefore, there is still need to determine the optimal torque value for getting the optimal cell performance. This study has been carried out in continuation of deve­lopment of Air breathing PEM fuel cell for small Unmanned Aerial Vehicle (UAV application. Compaction pressure at minimum contact resistance was determined and clamping torque value was calcu­la­ted accordingly. Single cell performance tests were performed at five different clamping torque values i.e 0.5, 1.0, 1.5, 2.0 and 2.5 N m, for achieving optimal cell per­formance. Clamping pressure distribution tests were also performed at these torque values to verify uniform pressure distribution at optimal torque value. Experimental and theoretical results were compared for making inferences about optimal cell perfor­man­ce. A

  9. Percutaneous placement of bird's nest inferior vena cava filter

    International Nuclear Information System (INIS)

    To describe clinical experiences of the use of Bird's Nest inferior vena cava(IVC) filter. Between August 1991 and August 1997, IVC filter was percutaneously inserted in 51 patients with pulmonary embolism(PE) and deep vein thrombosis of the lower extremities. Indications for the placement of this filter were contraindication to anticoagulation in 17 patients, prophylaxis of PE in 17, failed anticoagulation in 11, massive PE with residual floating thrombus in three and complications involving anticoagulation in 3. In order to delineate the location of renal vein and extension of deep vein thrombosis into the IVC, all patients under went inferior vena cavography before filter placement. Thirty filters were inserted through the right femoral vein, 19 through the right internal jugular vein and three through the left femoral vein. The patients involved were followed up for periods ranging from one week to six years (mean 10 months). A Bird's Nest IVC filter was placed in the infrarenal IVC in 44 patients and in the suprarenal IVC in 7. Certain complicatioins ensued. IVC penetration occurred in three patients(5.9%), and in seven(1.37%) the filter wire prolapsed. Except for transient pain, however, there were no serious IVC penetration-related complications and no evidence of recurrence of PE in the cases involving prolapse of the filter wire. During follow up, clinically suspected recurrent PE was noted in two patients(3.9%), but there was no evidence of newly developed occlusion of the IVC. In patients who under went follow up, Bird's Nest IVC filter effectively prevented the development and recurrence of PE, and there were no complications. To prevent of penetration of the IVC and prolapse of the filter, however, technical skill was needed

  10. Left inferior frontal gyrus is critical for response inhibition

    Directory of Open Access Journals (Sweden)

    Ashley Victoria

    2008-10-01

    Full Text Available Abstract Background Lesion studies in human and non-human primates have linked several different regions of prefrontal cortex (PFC with the ability to inhibit inappropriate motor responses. However, recent functional neuroimaging studies have specifically implicated right inferior PFC in response inhibition. Right frontal dominance for inhibitory motor control has become a commonly accepted view, although support for this position has not been consistent. Particularly conspicuous is the lack of data on the importance of the homologous region in the left hemisphere. To investigate whether the left inferior frontal gyrus (IFG is critical for response inhibition, we used neuropsychological methodology with carefully characterized brain lesions in neurological patients. Results Twelve individuals with damage in the left IFG and the insula were tested in a Go/NoGo response inhibition task. In alternating blocks, the difficulty of response inhibition was easy (50% NoGo trials or hard (10% NoGo trials. Controls showed the predicted pattern of faster reaction times and more false alarm errors in the hard condition. Left IFG patients had higher error rates than controls in both conditions, but were more impaired in the hard condition, when a greater degree of inhibitory control was required. In contrast, a patient control group with orbitofrontal cortex lesions showed intact performance. Conclusion Recent neuroimaging studies have focused on a highly specific association between right IFG and inhibitory control. The present results indicate that the integrity of left IFG is also critical for successful implementation of inhibitory control over motor responses. Our findings demonstrate the importance of obtaining converging evidence from multiple methodologies in cognitive neuroscience.

  11. Detection by means of CT of inferior vena cava filters

    International Nuclear Information System (INIS)

    Vena cava filters are an excellent tool for the prevention of pulmonary embolism (PE) in patients with deep vein thrombosis (DVT) of the lower limbs. However, these devices are not entirely free of complications as thrombi can develop inside them, threatening to occlude them completely. The objective of this report is to study the incidence of thrombosis in vena cava filters, as well as their impact on prognosis. We also mention the importance of CT as an imaging technique in the study of this complication. We present 30 patients in whom different filters were implanted and their prospective follow-up by means of CT over a mean follow-up period of 36 months. Chi-square analysis was used to determine whether there was a significant relationship among the complications encountered (p<0,05), and their course over time was studied by means of Kaplan-Meyer curves. Five cases (16%) of complete thrombosis of the filter were observed among patients in whom the Gunther model had been implanted, yielding an index of probability of complete permeability of the inferior vena cava at 13 months of 82%. Thrombi of different degrees (between 5% and 60%) were also observed inside the filter in ten patients (33%) with Gunther, Simon-Nitional and LGM models. Filter thrombosis was not significantly associated with the onset of recurrent PE or of venous disorders involving lower limbs, the relationship between PE and preimplantation presence of inferior vena cava thrombosis was significant (p<0.01). It was also observed that post implantation anti coagulation did not significantly prevent later onset of filter thrombosis. (Author)

  12. Inferior vena cava leiomyosarcoma confirmed by catheter suction biopsy during digital subtraction angiography

    OpenAIRE

    Wei, Ning; Xu, Xiang-Dong; Xu, Hao; ZU, MAO-HENG

    2014-01-01

    Leiomyosarcoma of vascular origin is a rare disease and most cases arise in the inferior vena cava. Inferior vena cava leiomyosarcoma (IVCLMS) usually presents in females in their sixth decade of life. The clinical symptoms are often non-specific and the diagnosis is often delayed. Current imaging techniques can accurately differentiate inferior vena cava neoplasms from other non-neoplastic lesions. However, definitive diagnosis of IVCLMS needs histologic evidence. We report a case of IVCLMS ...

  13. In vivo measurements of whole body (WB) and skeletal muscle glucose metabolism under basal and euglycemic insulin clamp (Clamp) by combined PET and stable isotope (SI) tracer studies

    International Nuclear Information System (INIS)

    Aim/Background: Primed-constant infusion of SI labeled tracers is a classic technique for studying metabolism at the WB level, however, this procedure provides no information about the metabolism of specific tissues. In contrast PET provides primarily tissue specific data. In this study, we combined PET with SI techniques to measure glucose metabolism in WB and lower limb skeletal muscle (LLM) of humans under Basal and Clamp conditions. Methods and Materials: Four healthy volunteers (73.0 ± 6.0 kg, mean ± sem) were studied. After fasting overnight, each subject was injected with 10 mCi of 18FDG and serial 1.0 min. PET images of the mid-thigh region were acquired over 90 min. Arterial blood samples were collected in parallel. Glucose metabolic rate (GM) was calculated with a 3-compartment / 4 rate constant model; LC assumed to be 1.0. A primed constant infusion of [6,6, 2H2]glucose was performed in parallel with the PET measurements. On another day, the PET and SI measurements were repeated under clamp conditions. All results are expressed as mean ± sem. Results: The glucose kinetics in whole body and in low limb skeletal muscles are shown. Under in vivo conditions, Clamp caused: 1) a 10.2 ± 2.3 fold increase in GM by LLM but only a 4.7 ± 0.4 fold increase in GM by MB. 2) Increased contribution of LLM to WB GM, indicating that LLM GM is more sensitive to insulin compared with anterior LLM (extensors). Discussion: The study demonstrated the unique advantages of using PET to study substrate metabolism in specific tissues in human subjects: i) It is less invasive than the conventional A-V difference and muscle biopsy method. ii) It provides a more detailed picture of substrate metabolism in different parts of the muscle in the same limb, as compared to one spot muscle biopsy. Data in demonstrated that GM in posterior LLM is more sensitive to insulin than that in anterior LLM. iii) It can detect substrate metabolism in deep muscles which cannot be reached by biopsy

  14. INFERIORITY COMPLEX AND ASSERTIVENESS AMONG UG STUDENTS STUDIED IN ENGLISH th AND VERNACULAR LANGUAGE IN 12 STANDARD.

    OpenAIRE

    S. Shalini

    2014-01-01

    The present paper focused on the aspects of inferiority complex and assertiveness among students .By participating in student life, students realize their abilities and creativity. But some students develop inferiority complex in their life. The problem of Inferiority complex among adolescents is becoming increasingly alarming. Teenage years are the prime years of bearing the burden of inferiority feelings. This study was done to assess the inferiority complex ( measured b...

  15. Simulation Based Performance analysis of Active Clamp DHB ZVZCS Bidirectional DC-DC converter for Low Power Applications

    Directory of Open Access Journals (Sweden)

    V.V.Subrahmanya Kumar Bhajana

    2012-06-01

    Full Text Available A novel active clamp dual half bridge DC/DC converter with bidirectional power flow is proposed in this paper and comparative analysis between active clamp DHB ZVZCS and ZVS-ZCS bidirectional DC-DC converter topologies is also presented. By adding active clamping circuits to both bridges, zero voltage and zero current switching are achieved to improve the performance of the bidirectional DC/DC converter. The principle of operation is analyzed and simulated. With the proposed active clamp ZVZCS concept, the MATLAB simulation results of the applications of the fuel cell and battery have been obtained and compared with those of ZVS-ZCS bidirectional converter. The simulation results of proposed converter is compared with the ZVS-ZCS bidirectional DC-DC converter, efficiency, switching losses are the key parameters compared.

  16. Robotic clamp and index tool and method for their use in repairing certain elements with in a nuclear reactor

    International Nuclear Information System (INIS)

    This patent describes a clamp-and-index tool for use in the replacement of old split-pin assemblies of a guide tube of a nuclear reactor by new split-pin assemblies, the old split-pin assemblies and the guide tube being radioactive and the clamp-and-index tool to operate under a pool of water. The tool includes means, to be connected to the guide tube, for suspending the guide tube in a first position in which the tube is to be processed to effect the replacement. The tool also includes a means, connected to the suspending means, for rotating the guide tube to a second position in which the tube is to be processed to effect the replacement and clamping means, connected to the suspending means and to be connected to the guide tube, for selectively clamping the guide tube in the first or second position

  17. Structure-function analysis of the C-clamp of TCF/Pangolin in Wnt/ß-catenin signaling.

    Directory of Open Access Journals (Sweden)

    Aditi J Ravindranath

    Full Text Available The evolutionarily conserved Wnt/ß-catenin (Wnt/ß-cat pathway plays an important role in animal development in metazoans. Many Wnt targets are regulated by members of the TCF/LEF1 (TCF family of transcription factors. All TCFs contain a High Mobility Group (HMG domain that bind specific DNA sequences. Invertebrate TCFs and some vertebrate TCF isoforms also contain another domain, called the C-clamp, which allows TCFs to recognize an additional DNA motif known as the Helper site. While the C-clamp has been shown to be important for regulating several Wnt reporter genes in cell culture, its physiological role in regulating Wnt targets is less clear. In addition, little is known about this domain, except that two of the four conserved cysteines are functionally important. Here, we carried out a systematic mutagenesis and functional analysis of the C-clamp from the Drosophila TCF/Pangolin (TCF/Pan protein. We found that the C-clamp is a zinc-binding domain that is sufficient for binding to the Helper site. In addition to this DNA-binding activity, the C-clamp also inhibits the HMG domain from binding its cognate DNA site. Point mutations were identified that specifically affected DNA-binding or reduced the inhibitory effect. These mutants were characterized in TCF/Pan rescue assays. The specific DNA-binding activity of the C-clamp was essential for TCF/Pan function in cell culture and in patterning the embryonic epidermis of Drosophila, demonstrating the importance of this C-clamp activity in regulating Wnt target gene expression. In contrast, the inhibitory mutation had a subtle effect in cell culture and no effect on TCF/Pan activity in embryos. These results provide important information about the functional domains of the C-clamp, and highlight its importance for Wnt/ß-cat signaling in Drosophila.

  18. Modulation of major voltage- and ligand-gated ion channels in cultured neurons of the rat inferior colliculus by lidocaine

    Institute of Scientific and Technical Information of China (English)

    Mu YU; Lin CHEN

    2008-01-01

    Aim: The purpose of the present study was to explore how lidocaine as a thera-peutic drug for tinnitus targets voltage- and ligand-gated ion channels and changes the excitability of central auditory neurons. Methods: Membrane cur-rents mediated by major voltage- and ligand-gated channels were recorded from primary cultured neurons of the inferior colliculus (IC) in rats with whole-cell patch-clamp techniques in the presence and absence of lidocaine. The effects of lidocaine on the current-evoked firing of action potentials were also exam-ined. Results: Lidocaine at 100 μmol/L significantly suppressed voltage-gated sodium currents, transient outward potassium currents, and the glycine-induced chloride currents to 87.66%±2.12%, 96.33%±0.35%, and 91.46%±2.69% of that of the control level, respectively. At 1 mmol/L, lidocaine further suppressed the 3 currents to 70.26%±4.69%, 62.80% ±2.61%, and 89.11%±3.17% of that of the control level, respectively, However, lidocaine at concentrations lower than 1 mmol/L did not significantly affect GABA- or aspartate-induced currents. At a higher concentration (3 retool/L), lidocaine slightly depressed the GABA-in-duced current to 87.70%±1.87% of that of the control level. Finally, lidocaine at 100 μmol/L was shown to significantly suppress the current-evoked firing of IC neurons to 58.62%±11.22% of that of the control level, indicating that lidocaine decreases neuronal excitability. Conclusion: Although the action of lidocaine on the ion channels and receptors is complex and non-specific, it has an overall inhibitory effect on IC neurons at a clinically-relevant concentration, suggesting a central mechanism for lidocaine to suppress tinnitus.

  19. The Analysis of Clamping Mechanism Theory and the Application Design of Tobacco Leaves'Clamping Tool%夹紧机构的理论分析及烘烤烟叶夹的应用设计

    Institute of Scientific and Technical Information of China (English)

    徐远龙; 孙有祥

    2011-01-01

    In view of the complicated manual skill of the tobacco leaf weaving, the study and design of a kind tool clamping tobacco leaf is proposed by our actual investigation; According to the predetermined function demand and the available clamping mechanism, the principle of the clamping tool is studied out, the structural design scheme of the clamping tool is worked out and the clamping tool is made by the theory analysis of mechanism design and the study of clamping mechanism. The clamping tool tested by the surveyor is good in use, which is welcome to use by the peasants and the economy benefit of the market can be achieved highly.%通过对烟叶烘烤生产工艺的实际调研,针对手工繁杂的编烟技术,提出了研究设计一种烘烤烟叶夹持工具;针对烘烤烟叶夹的预定功能要求,参考现有的实用夹紧机构,通过对机械产品机构设计的理论分析和夹紧机构的力学研究,确定了夹紧烟叶的力学原理,提出了烘烤烟叶夹的结构设计方案,设计制造出烘烤烟叶夹;该烘烤烟叶夹通过了产品的质量检测,使用效果良好,烟农用户普遍接受使用,预计有较高的市场经济效益.

  20. Clamping end-tidal carbon dioxide during graded exercise with control of inspired oxygen.

    Science.gov (United States)

    Farra, Saro D; Kessler, Cathie; Duffin, James; Wells, Greg D; Jacobs, Ira

    2016-09-01

    Exercise- and hypoxia-induced hyperventilation decreases the partial pressure of end-tidal carbon dioxide (PETCO2), which in turn exerts many physiological effects. Several breathing circuits that control PETCO2 have been previously described, but their designs are not satisfactory for exercise studies where changes in inspired oxygen (FIO2) may be desired. This study is the first report of a breathing system that can maintain PETCO2 constant within a single session of graded submaximal exercise and graded hypoxia. Thirteen fit and healthy subjects completed two bouts of exercise consisting of three 3min stages on a cycle ergometer with increasing exercise intensity in normoxia (Part A; 142±14, 167±14, 192±14W) or with decreasing FIO2 at a constant exercise intensity (Part B; 21, 18, and 14%). One bout was a control (CON) where PETCO2 was not manipulated, while during the other bout the investigator clamped PETCO2 within 2mmHg (CO2Clamp) using sequential gas delivery (SGD). During the final 30s of each exercise stage during CO2Clamp, PETCO2 was successfully maintained in Part A (43±4, 44±4, 44±3mmHg; P=0.44) and Part B (45±3, 46±3, 45±3mmHg; P=0.68) despite the increases in ventilation due to exercise. These findings demonstrate that this SGD circuit can be used to maintain isocapania in exercising humans during progressively increasing exercise intensities and changing FIO2. PMID:27236039

  1. Plasmodium falciparum: analysis of chromosomes separated by contour-clamped homogenous electric fields.

    Science.gov (United States)

    Gu, H; Inselburg, J W; Bzik, D J; Li, W B

    1990-08-01

    We have established improved conditions for separating the chromosomes of Plasmodium falciparum by pulsed field gradient gel electrophoresis (PFG) using a contour-clamped homogenous electric field (CHEF) apparatus. Thirteen clearly separable chromosomal bands were reproducibly isolated from the strain FCR3 and their sizes have been determined. Evidence that indicates one band may contain two chromosomes is presented. The relationship between the PFG separable DNA and the number of unique chromosomes in P. falciparum is considered. We have established a relationship between the maximum resolvable sizes of the chromosomes and the pulse times. The chromosomal location of twenty-seven P. falciparum DNA probes is also reported. PMID:2197113

  2. Enhanced Buck-Boost Three-Level Neutral-Point-Clamped Inverters

    DEFF Research Database (Denmark)

    Tan, K. K.; Gao, F.; Chiang Loh, Poh; Blaabjerg, Frede

    In traditional three-level neutral-point-clamped (NPC) inverters, a major issue is capacitor voltage imbalance, which results in low order harmonics. The compensation of the capacitor voltages often require additional control complexity, which cannot be conveniently implemented. The "alternative...... method, with the ability to easily adjust for capacitor voltage imbalances. To further improve the boost capability of the three-level NPC inverters, another new topology introduces 2 additional diodes,achieving higher boost performance while totally eliminating thepossibility of capacitor voltage...

  3. Trans-Z-source and Γ-Z-source neutral-point-clamped inverters

    DEFF Research Database (Denmark)

    Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede; Wang, Peng

    2015-01-01

    Z-source neutral-point-clamped (NPC) inverters are earlier proposed for obtaining voltage buck-boost and three-level switching simultaneously. Their performances are, however, constrained by a trade-off between their input-to-output gain and modulation ratio. This trade-off can lead to high-voltage...... stress across the inverter bridge and poor output voltage spectrum. As alternatives with improved performances, two transformer-based Z-source NPC inverters are proposed, whose gain can be adjusted by varying the transformer turns ratio, and is hence less dependent on the inverter modulation ratio...

  4. HERG channel (dys)function revealed by dynamic action potential clamp technique

    OpenAIRE

    Berecki, G; Zegers, J.G.; Verkerk, A.O.; Bhuiyan, Z.A.; Jonge, de, M.J.I.; Veldkamp, M.W.; Wilders, R; Ginneken, van, CJJM Kees

    2005-01-01

    The human ether-a-go-go-related gene (HERG) encodes the rapid component of the cardiac delayed rectifier potassium current (IKr). Per-Arnt-Sim domain mutations of the HERG channel are linked to type 2 long-QT syndrome. We studied wild-type and/or type 2 long-QT syndrome-associated mutant (R56Q) HERG current (IHERG) in HEK-293 cells, at both 23 and 36°C. Conventional voltage-clamp analysis revealed mutation-induced changes in channel kinetics. To assess functional implication(s) of the mutatio...

  5. Strong localization induced by one clamped point in thin plate vibrations.

    Science.gov (United States)

    Filoche, Marcel; Mayboroda, Svitlana

    2009-12-18

    We discover a strong localization of flexural (bi-Laplacian) waves in rigid thin plates. We show that clamping just one point inside such a plate not only perturbs its spectral properties, but essentially divides the plate into two independently vibrating regions. This effect progressively appears when increasing the plate eccentricity. Such a localization is qualitatively and quantitatively different from the results known for the Laplacian waves in domains of irregular boundary. It would allow us to control the confinement of mechanical vibrations in rigid plates and of eddies in the slow Stokes flow. PMID:20366256

  6. Sodium influxes in internally perfused squid giant axon during voltage clamp.

    Science.gov (United States)

    Atwater, I; Bezanilla, F; Rojas, E

    1969-05-01

    1. An experimental method for measuring ionic influxes during voltage clamp in the giant axon of Dosidicus is described; the technique combines intracellular perfusion with a method for controlling membrane potential.2. Sodium influx determinations were carried out while applying rectangular pulses of membrane depolarization. The ratio ;measured sodium influx/computed ionic flux during the early current' is 0.92 +/- 0.12.3. Plots of measured sodium influx and computed ionic flux during the early current against membrane potential are very similar. There was evidence that the membrane potential at which the sodium influx vanishes is the potential at which the early current reverses. PMID:5767887

  7. Thermal and Efficiency Analysis of Five-Level Multilevel-Clamped Multilevel Converter Considering Grid Codes

    DEFF Research Database (Denmark)

    Ma, Ke; Muñoz-Aguilar, R. S.; Rodriguez, Pedro; Blaabjerg, Frede

    2014-01-01

    In this paper, a five-level multilevel-clamped multilevel converter (5L- MLC2) topology is analyzed based on a typical grid integration application for renewable energy system. The loss and thermal distributions of the power devices in different switching legs are investigated and illustrated under...... rated condition. Afterward, a loss and efficiency evaluation method is proposed and applied which takes into account various injected reactive power ranges regulated by the grid codes. It is concluded that the loss and thermal distributions of the 5L- MLC2 multilevel topology are unequal between the...

  8. Surface analysis of anodized aluminum clamps from NASA-LDEF satellite

    Science.gov (United States)

    Grammer, H. L.; Wightman, J. P.; Young, Philip R.

    1992-01-01

    Surface analysis results of selected anodized aluminum clamps containing black (Z306) and white (A276) paints which received nearly six years of Low Earth Orbit (LEO) exposure on the Long Duration Exposure Facility are reported. Surface analytical techniques, including x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and scanning electron microscopy/energy dispersive analysis by x-ray (SEM/EDAX), showed significant differences in the surface composition of these materials depending upon the position on the LDEF. Differences in the surface composition are attributed to varying amounts of atomic oxygen and vacuum ultraviolet radiation (VUV). Silicon containing compounds were the primary contaminant detected on the materials.

  9. Modeling of Busbars in High Power Neutral Point Clamped Three-Level Inverters

    Institute of Scientific and Technical Information of China (English)

    YI Rung; ZHAO Zhengming; ZHONG Yulin

    2008-01-01

    The busbars in high power neutral point clamped three-level inverters are modeled using the Maxwell Q3D Extractor software, which is based on the partial element equivalent circuits method. The equivalent circuits of the busbars and devices model are simulated in the electric simulator PSIM to analyze the effects of the parasitic inductance on the switching characteristics of the integrated gate commutatedthyristor (IGCT) in different topology positions. The simulation results agree well with the measured imped-ance analyzer results and the IGCT test results, which proves the effectiveness of the modeling method for the large, complex busbars.

  10. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify design, increase efficiency and integration level, reduce product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented. (au)

  11. A broadly tunable fiber ring laser employing a gain-clamped semiconductor optical amplifier

    International Nuclear Information System (INIS)

    A widely tunable fiber ring laser is demonstrated experimentally using a specially designed gain-clamped semiconductor optical amplifier (GC-SOA). The 3 dB bandwidth of the generated amplified spontaneous emission is increased by 10 nm using the GC-SOA. The lasing wavelength is continuously tunable in a range from 1522 nm to almost 1600 nm using a thin-film Fabry–Pérot tunable filter. A side-mode-suppression ratio of greater than 55 dB is achieved over the entire tuning range. (paper)

  12. Paired Patch Clamp Recordings from Motor-neuron and Target Skeletal Muscle in Zebrafish

    OpenAIRE

    Wen, Hua; Brehm, Paul

    2010-01-01

    Larval zebrafish represent the first vertebrate model system to allow simultaneous patch clamp recording from a spinal motor-neuron and target muscle. This is a direct consequence of the accessibility to both cell types and ability to visually distinguish the single segmental CaP motor-neuron on the basis of morphology and location. This video demonstrates the microscopic methods used to identify a CaP motor-neuron and target muscle cells as well as the methodologies for recording from each c...

  13. Effect of La3+ on myocardiac potassium channels revealed by patch-clamp technique

    Institute of Scientific and Technical Information of China (English)

    XUE Shaowu; YANG Pin

    2005-01-01

    The effect of La3+ on potassium channels in rat ventricular myocytes was investigated using the whole-cell patch-clamp recording mode. The Ca2+-independent voltage- activated outward K+ current was activated by the depolarizing pulse in enzymatically isolated rat ventricular myocytes. After addition of different concentrations La3+ to the bath solution, the outward K+ current was depressed gradually. The inhibition effect was in a concentration-dependent manner. The phenomena of the outward K+ current, being the main repolarizing current suppressed by La3+, suggest that the effect of lanthanides on myocardial function should be exploited further.

  14. Patch Clamp Recordings in Inner Ear Hair Cells Isolated from Zebrafish

    OpenAIRE

    Einarsson, Rachel; Haden, Marshall; DiCiolli, Gabrielle; Lim, Andrea; Mah-Ginn, Kolina; Aguilar, Kathleen; Yazejian, Lucy; Yazejian, Bruce

    2012-01-01

    Patch clamp analyses of the voltage-gated channels in sensory hair cells isolated from a variety of species have been described previously1-4 but this video represents the first application of those techniques to hair cells from zebrafish. Here we demonstrate a method to isolate healthy, intact hair cells from all of the inner ear end-organs: saccule, lagena, utricle and semicircular canals. Further, we demonstrate the diversity in hair cell size and morphology and give an example of the kind...

  15. Micro-agar salt bridge in patch-clamp electrode holder stabilizes electrode potentials

    OpenAIRE

    Shao, Xuesi M; Feldman, Jack L.

    2006-01-01

    Maintaining a stable electrode potential is critical for patch-clamp measurements. The electrode potential of conventional patch electrode-holder assembly, where an Ag/AgCl wire is in direct contact with the patch pipette filling solution, is subject to drift if the pipette solution contains a low concentration of chloride ions (Cl−). We developed an agar bridge of 3 M KCl filled in a polyimide microtubing which forms an electrical connection between an Ag/AgCl wire and the pipette solution. ...

  16. Voltage-clamp frequency domain analysis of NMDA-activated neurons.

    Science.gov (United States)

    Moore, L E; Hill, R H; Grillner, S

    1993-02-01

    1. Voltage and current-clamp steps were added to a sum of sine waves to measure the tetrodotoxin-insensitive membrane properties of neurons in the intact lamprey spinal cord. A systems analysis in the frequency domain was carried out on two types of cells that have very different morphologies in order to investigate the structural dependence of their electrophysiological properties. The method explicitly takes into account the geometrical shapes of (i) nearly spherical dorsal cells with one or two processes and (ii) motoneurons and interneurons that have branched dendritic structures. Impedance functions were analysed to obtain the cable properties of these in situ neurons. These measurements show that branched neurons are not isopotential and, therefore, a conventional voltage-clamp analysis is not valid. 2. The electrophysiological data from branched neurons were curve-fitted with a lumped soma-equivalent cylinder model consisting of eight equal compartments coupled to an isopotential cell body to obtain membrane parameters for both passive and active properties. The analysis provides a quantitative description of both the passive electrical properties imposed by the geometrical structure of neurons and the voltage-dependent ionic conductances determined by ion channel kinetics. The model fitting of dorsal cells was dominated by a one-compartment resistance and capacitance in parallel (RC) corresponding to the spherical, non-branched shape of these cells. Branched neurons required a model that contained both an RC compartment and a cable that reflected the structure of the cells. At rest, the electrotonic length of the cable was about two. Uniformly distributed voltage-dependent ionic conductance sites were adequate to describe the data at different membrane potentials. 3. The frequency domain admittance method in conjunction with a step voltage clamp was used to control and measure the oscillatory behavior induced by N-methyl-D-aspartate (NMDA) on lamprey spinal

  17. LETTER TO THE EDITOR: Stretching of proteins in a force-clamp

    Science.gov (United States)

    Szymczak, P.; Cieplak, Marek

    2006-01-01

    Mechanically induced protein unfolding in the force-clamp apparatus is shown, in a coarse-grained model of ubiquitin, to have lognormal statistics above a threshold force and exponential statistics below it. Correspondingly, the mean unfolding time is slowly varying and exponentially decreases as a function of the force. The time dependences of the end-to-end distances are also distinct. The time sequence of unfolding events weakly depends on force and much of it resembles that for stretching at constant speed. A more complicated time dependence arises for integrin.

  18. Acute hypotension induced by aortic clamp vs. PTH provokes distinct proximal tubule Na+ transporter redistribution patterns

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; Lin, Harrison W;

    2004-01-01

    renal cortical membranes fractionated on sorbitol density gradients. Aortic clamp-induced acute hypotension (from 100 +/- 3 to 78 +/- 2 mmHg) provoked a 62% decrease in urine output and a significant decrease in volume flow from the proximal tubule detected as a 66% decrease in endogenous lithium...... clearance. There was, however, no significant change in glomerular filtration rate (GFR) or subcellular distribution of NHE3 and NaPi2. In contrast, high-dose PTH rapidly (<2 min) decreased arterial blood pressure to 51 +/- 3 mmHg, decreased urine output, and shifted NHE3 and NaPi2 out of the low...

  19. Characterization of the insulin sensitivity of ghrelin receptor KO mice using glycemic clamps

    Directory of Open Access Journals (Sweden)

    Morgan Kristen

    2011-01-01

    Full Text Available Abstract Background We and others have demonstrated previously that ghrelin receptor (GhrR knock out (KO mice fed a high fat diet (HFD have increased insulin sensitivity and metabolic flexibility relative to WT littermates. A striking feature of the HFD-fed GhrR KO mouse is the dramatic decrease in hepatic steatosis. To characterize further the underlying mechanisms of glucose homeostasis in GhrR KO mice, we conducted both hyperglycemic (HG and hyperinsulinemic-euglycemic (HI-E clamps. Additionally, we investigated tissue glucose uptake and specifically examined liver insulin sensitivity. Results Consistent with glucose tolerance-test data, in HG clamp experiments, GhrR KO mice showed a reduction in glucose-stimulated insulin release relative to WT littermates. Nevertheless, a robust 1st phase insulin secretion was still achieved, indicating that a healthy β-cell response is maintained. Additionally, GhrR KO mice demonstrated both a significantly increased glucose infusion rate and significantly reduced insulin requirement for maintenance of the HG clamp, consistent with their relative insulin sensitivity. In HI-E clamps, both LFD-fed and HFD-fed GhrR KO mice showed higher peripheral insulin sensitivity relative to WT littermates as indicated by a significant increase in insulin-stimulated glucose disposal (Rd, and decreased hepatic glucose production (HGP. HFD-fed GhrR KO mice showed a marked increase in peripheral tissue glucose uptake in a variety of tissues, including skeletal muscle, brown adipose tissue and white adipose tissue. GhrR KO mice fed a HFD also showed a modest, but significant decrease in conversion of pyruvate to glucose, as would be anticipated if these mice displayed increased liver insulin sensitivity. Additionally, the levels of UCP2 and UCP1 were reduced in the liver and BAT, respectively, in GhrR KO mice relative to WT mice. Conclusions These results indicate that improved glucose homeostasis of GhrR KO mice is

  20. Generalizing Screen Inferiority--Does the Medium, Screen versus Paper, Affect Performance Even with Brief Tasks?

    Science.gov (United States)

    Sidi, Yael; Ophir, Yael; Ackerman, Rakefet

    2016-01-01

    Screen inferiority in performance and metacognitive processes has been repeatedly found with text learning. Common explanations for screen inferiority relate to technological and physiological disadvantages associated with extensive reading on screen. However, recent studies point to lesser recruitment of mental effort on screen than on paper.…

  1. Does the Left Inferior Longitudinal Fasciculus Play a Role in Language? A Brain Stimulation Study

    Science.gov (United States)

    Mandonnet, Emmanuel; Nouet, Aurelien; Gatignol, Peggy; Capelle, Laurent; Duffau, Hugues

    2007-01-01

    Although advances in diffusion tensor imaging have enabled us to better study the anatomy of the inferior longitudinal fasciculus (ILF), its function remains poorly understood. Recently, it was suggested that the subcortical network subserving the language semantics could be constituted, in parallel with the inferior occipitofrontal fasciculus, by…

  2. Mesoaortic entrapment of a left inferior vena cava

    International Nuclear Information System (INIS)

    A persistent left inferior vena cava (IVC) is a rare anomaly, with a reported incidence of only 0.2-0.5%. When present, it courses between the superior mesenteric artery and the aorta to continue as the right IVC, similar to the course of a left renal vein (LRV). This anomaly is usually asymptomatic, but there may be vague abdominal complaints if the IVC is compressed in the mesoaortic angle. Although symptomatic compression of the LRV (anterior nutcracker syndrome) is well recognized, there has been only one report in the literature of a similar compression of a persistent left IVC. Because of its rarity, this anomaly may be missed or mistaken for other conditions on imaging. An accurate diagnosis is crucial as the presence of this anomaly may have implications for surgical treatment of aortic lesions or placement of an IVC filter. Magnetic resonance angiography and, more recently, multidetector computed tomography scan, can provide an exquisite three-dimensional demonstration of vascular abnormalities

  3. Right inferior longitudinal fasciculus lesions disrupt visual-emotional integration.

    Science.gov (United States)

    Fischer, David B; Perez, David L; Prasad, Sashank; Rigolo, Laura; O'Donnell, Lauren; Acar, Diler; Meadows, Mary-Ellen; Baslet, Gaston; Boes, Aaron D; Golby, Alexandra J; Dworetzky, Barbara A

    2016-06-01

    The mechanism by which the brain integrates visual and emotional information remains incompletely understood, and can be studied through focal lesions that selectively disrupt this process. To date, three reported cases of visual hypoemotionality, a vision-specific form of derealization, have resulted from lesions of the temporo-occipital junction. We present a fourth case of this rare phenomenon, and investigate the role of the inferior longitudinal fasciculus (ILF) in the underlying pathophysiology. A 50-year-old right-handed male was found to have a right medial temporal lobe tumor following new-onset seizures. Interstitial laser ablation of the lesion was complicated by a right temporo-parieto-occipital intraparenchymal hemorrhage. The patient subsequently experienced emotional estrangement from visual stimuli. A lesion overlap analysis was conducted to assess involvement of the ILF by this patient's lesion and those of the three previously described cases, and diffusion tensor imaging was acquired in our case to further investigate ILF disruption. All four lesions specifically overlapped with the expected trajectory of the right ILF, and diminished structural integrity of the right ILF was observed in our case. These findings implicate the ILF in visual hypoemotionality, suggesting that the ILF is critical for integrating visual information with its emotional content. PMID:26940563

  4. PERIPHERAL HEARING LOSS CAUSES HYPEREXCITABILITY OF THE INFERIOR COLLICULUS

    Institute of Scientific and Technical Information of China (English)

    Sun Wei

    2013-01-01

    Growing evidence has been found to suggest that early development of the central auditory system is dependent on acoustic stimuli. Peripheral damage caused by noise exposure and ototoxic drugs can induce functional and anatomical changes along the auditory pathways. The inferior colliculus (IC) is a unique structure in the auditory system located between the primary auditory nuclei of the brainstem and the thala-mus. Damage to the IC inhibitory circuitry may affect central auditory processing and sound perception. Here, we review some of the striking electrophysiological changes in the IC that occur after noise exposure and ototoxic drug treatment. A common occurrence that emerges in the IC after peripheral damage is hyper-excitability of sound-evoked response. The hyperexcitability of the IC is likely related with reduced inhibi-tory response that requires normal peripheral inputs. Early age hearing loss can result in a long lasting in-creased susceptibility to audiogenic seizure which is related to hyperactivity in the IC evoked by loud sounds. Our studies suggest that hearing loss can cause increased IC neuron responsiveness which may be related to tinnitus, hyperacusis, and audiogenic seizure.

  5. Surgical treatment of painful lesions of the inferior alveolar nerve.

    Science.gov (United States)

    Biglioli, Federico; Allevi, Fabiana; Lozza, Alessandro

    2015-10-01

    Nerve-related complications are being reported with increasing frequency following oral and dental surgery, and typically involve the inferior alveolar nerve (IAN). We assess herein the etiology of neuropathic pain related to IAN injuries, and describe the various surgical treatment techniques available. Between 2007 and 2013, 19 patients were referred to the Maxillofacial Surgery Department of San Paolo Hospital (Milan, Italy) with pain in the area supplied by the IAN, which developed following endodontic treatment, oral surgery and maxillofacial surgery. All patients underwent IAN surgery by several different microsurgical procedures. Most of the patients affected by pain before surgery experienced complete or partial amelioration of symptoms. All patients receiving sural nerve grafts were pain-free 12 months after surgery. In five patients the operation was unsuccessful. In 78.94% of cases, a significant increase in nerve function was observed. Pain following IAN surgical damage may be addressed by microsurgery; nerve substitution with a sural nerve interpositional graft appears to represent the most efficacious procedure. Scar releasing, nerve decompression and nerve substitution using vein grafts are less effective. Removal of endodontic material extravasated into the mandibular canal is mandatory and effective in patients experiencing severe pain. Surgery should be performed within 12 months postoperatively, ideally during the first few weeks after symptoms onset. PMID:26315275

  6. Effect of Preoperative Pain on Inferior Alveolar Nerve Block.

    Science.gov (United States)

    Aggarwal, Vivek; Singla, Mamta; Subbiya, Arunajatesan; Vivekanandhan, Paramasivam; Sharma, Vikram; Sharma, Ritu; Prakash, Venkatachalam; Geethapriya, Nagarajan

    2015-01-01

    The present study tested the hypothesis that the amount and severity of preoperative pain will affect the anesthetic efficacy of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. One-hundred seventy-seven adult volunteer subjects, actively experiencing pain in a mandibular molar, participated in this prospective double-blind study carried out at 2 different centers. The patients were classified into 3 groups on the basis of severity of preoperative pain: mild, 1-54 mm on the Heft-Parker visual analog scale (HP VAS); moderate, 55-114 mm; and severe, greater than 114 mm. After IANB with 1.8 mL of 2% lidocaine, endodontic access preparation was initiated. Pain during treatment was recorded using the HP VAS. The primary outcome measure was the ability to undertake pulp access and canal instrumentation with no or mild pain. The success rates were statistically analyzed by multiple logistic regression test. There was a significant difference between the mild and severe preoperative pain group (P = .03). There was a positive correlation between the values of preoperative and intraoperative pain (r = .2 and .4 at 2 centers). The amount of preoperative pain can affect the anesthetic success rates of IANB in patients with symptomatic irreversible pulpitis. PMID:26650491

  7. The inferior cochlear vein: surgical aspects in cochlear implantation.

    Science.gov (United States)

    Guo, Rui; Zhang, HongLei; Chen, Wei; Zhu, XiaoQuan; Liu, Wei; Rask-Andersen, Helge

    2016-02-01

    The patency of the inferior cochlear vein (ICV) may be challenged in cochlear implantation (CI) due to its location near the round window (RW). This may be essential to consider during selection of different trajectories for electrode insertion aiming at preserving residual hearing. Venous blood from the human cochlea is drained through the ICV. The vein also drains blood from the modiolus containing the spiral ganglion neurons. Surgical interference with this vein could cause neural damage influencing CI outcome. We analyzed the topographical relationship between the RW and ICV bony channel and cochlear aqueduct (CA) from a surgical standpoint. Archival human temporal bones were further microdissected to visualize the CA and its accessory canals (AC1 and AC2). This was combined with examinations of plastic and silicone molds of the human labyrinth. Metric analyses were made using photo stereomicroscopy documenting the proximal portion of the AC1, the internal aperture of the CA and the RW. The mean distance between the AC1 and the anterior rim of the RW was 0.81 mm in bone specimens and 0.67 mm assessed in corrosion casts. The AC1 runs from the floor of the scala tympani through the otic capsule passing parallel to the CA to the posterior cranial fossa. The mean distance between the CA and AC1 canal was 0.31 and 0.25 mm, respectively. PMID:25700831

  8. Inferior vena cava filter placement in orthopedic surgery.

    Science.gov (United States)

    Bass, Anne R; Mattern, Christopher J; Voos, James E; Peterson, Margaret G E; Trost, David W

    2010-09-01

    Inferior vena cava (IVC) filters were developed for the treatment of venous thromboembolism but in high-risk patients are often used for prophylaxis instead. In the study reported here, we reviewed all the orthopedic surgery cases in which IVC filters were used at our institution in 2005. Charts were analyzed and patients contacted by telephone for long-term follow-up. IVC filters were used in 90 (0.96%) of the 9,348 inpatient orthopedic surgeries. Sixty-one percent of filters were placed for prophylaxis, though only 42% of patients with prophylactic filters had a contraindication to anticoagulation. Eighty-one percent of patients with prophylactic filters who received anticoagulation received warfarin. Ratios of prophylactic-to-treatment filters were 3.25 for fracture surgeries, 2.1 for arthroplasties, and 0.89 for spine surgeries. Five percent of patients with prophylactic filters developed deep vein thrombosis. Fifty-two percent of filters were retrievable, but only 40% of those were removed a mean of 5.1 months (SD, 3.9 months) after placement. Filter removal was associated with complications in 11% of patients, and in another 10% the filter could not be removed. Forty-one patients were contacted a mean of 21 months (SD, 3 months) after filter placement. Only 32% of those who still had filters were on anticoagulation at follow-up. PMID:21290021

  9. Obstruction increases activation in the right inferior frontal gyrus.

    Science.gov (United States)

    Liu, Tao; Saito, Hirofumi; Oi, Misato

    2016-08-01

    The right inferior frontal gyrus (IFG) is involved in intention understanding during interpersonal interactions. To examine how prior experience of cooperation and competition affects one's right IFG activation in the subsequent interaction, using near-infrared spectroscopy (NIRS) we simultaneously measured paired participants' bilateral IFG activations during a turn-taking game. Participant pairs were assigned to either one of two roles: a Builder taking the initial move to copy a target disk-pattern on monitor and the Partner taking the second move to aid in (cooperation) or to obstruct (competition) the Builder. The experiment consisted of two sessions. One participant (B-P) played as a Builder (B-) in session 1 and changed the role to the Partner (-P) in session 2, and vice versa for the paired participant (P-B). NIRS data in competition demonstrated that the Builder (B-) being obstructed in session 1 showed higher right IFG activation when (s)he took a role of obstructor (-P) in session 2 (the obstructed effect), whereas "the cooperated effect" was not revealed in cooperation. These results suggest that prior experience of being obstructed may facilitate understanding of the Builder and/or the obstructor's tactical move, thereby increasing his/her right IFG activation when one is meant to obstruct in subsequent competitions. PMID:26366676

  10. Advanced Techniques for Removal of Retrievable Inferior Vena Cava Filters

    Energy Technology Data Exchange (ETDEWEB)

    Iliescu, Bogdan; Haskal, Ziv J., E-mail: ziv2@mac.com [University of Maryland School of Medicine, Division of Vascular and Interventional Radiology (United States)

    2012-08-15

    Inferior vena cava (IVC) filters have proven valuable for the prevention of primary or recurrent pulmonary embolism in selected patients with or at high risk for venous thromboembolic disease. Their use has become commonplace, and the numbers implanted increase annually. During the last 3 years, in the United States, the percentage of annually placed optional filters, i.e., filters than can remain as permanent filters or potentially be retrieved, has consistently exceeded that of permanent filters. In parallel, the complications of long- or short-term filtration have become increasingly evident to physicians, regulatory agencies, and the public. Most filter removals are uneventful, with a high degree of success. When routine filter-retrieval techniques prove unsuccessful, progressively more advanced tools and skill sets must be used to enhance filter-retrieval success. These techniques should be used with caution to avoid damage to the filter or cava during IVC retrieval. This review describes the complex techniques for filter retrieval, including use of additional snares, guidewires, angioplasty balloons, and mechanical and thermal approaches as well as illustrates their specific application.

  11. Inferior vena cava filters: What radiologists need to know

    International Nuclear Information System (INIS)

    Inferior vena cava (IVC) filters are a controversial mechanical adjunct in the prevention of pulmonary embolism, the most serious result of venous thromboembolism. Despite modern IVC filters being in clinical use for more than 45 years, there is still uncertainty amongst many radiologists about the indications for IVC filter placement and their removal, particularly the more recent prophylactic use in patients without confirmed deep vein thrombosis (DVT) or pulmonary embolism (PE). Recently published guidelines on filter use from the National Institute of Health and Clinical Excellence (NICE) and other professional bodies are discussed. The vast majority of IVC filters in the UK are inserted by interventional radiologists, so radiologists may be the first point of contact for information requested by other clinicians. The increasing use of filters means that radiologists will encounter filters increasingly often during abdominal cross-sectional imaging. Awareness of common filter-related complications, such as tilting, thrombosis, and caval perforation, is useful to reassure or alert other clinicians. The potential role of filters in upper extremity DVT and requirement for concomitant anticoagulation is discussed

  12. The Quantitative Analysis to Inferior Oil with Electronic Nose Based on Adaptive Multilayer Stochastic Resonance

    Directory of Open Access Journals (Sweden)

    Hong Men

    2011-09-01

    Full Text Available This study makes the three acryl glycerin polymers, oxidation three acryl glycerins, and low carbon number fatty acid as inferior oil feature index. Using double steady state stochastic resonance signal-to-noise ratio analysis methods make the quantitative analysis to inferior oil. This paper analyzes the stochastic resonance. Introduces the principle detection system structure based on adaptive multilayer stochastic resonance algorithm in inferior oil quantitativeanalysis; and make adaptive double stochastic resonance model and inferior oil as example, give the simulation and numerical analysis of this model of the system. The results show that the system can obtain more accurate quality the proportion of the inferior oil information. At the same time, this method can effectively solve the semiconductor gas sensors of the baseline drift problem. The method of stochastic resonance has a lot of application prospect in improving the system performance.

  13. Impact of early versus delayed umbilical cord clamping on post partum blood loss: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Yogiraj Vaijanathrao Chidre,Vijayalakshmi Chirumamilla

    2015-08-01

    Methods: A randomized, controlled trial was performed on 183 consenting women fulfilling eligibility criteria in labour ward of a teaching hospital in India. They were randomly assigned into early cord clamping or delayed cord clamping group; other components of active management of third stage of labour being same for all. The duration of third stage of labour was noted. Quantitative assessment of post partum blood loss was done using BRASSS-V drapes and weighing blood soaked pads. Cord blood haemoglobin and hematocrit at birth and infant haemoglobin and hematocrit at 90 +/-7 days were estimated. Statistical analysis done using students unpaired and lsquo;t' test. Results: No difference was noted in the mean blood loss (203.52 +/- 122.74 ml versus 200.74+/- 104.07 ml in early and delayed cord clamping respectively and the duration of third stage of labour (Mean: 296.59+/- 98.97 seconds versus 281.79+/-104.59 seconds for early and delayed clamping respectively. Infant haemoglobin at 90 +/-7 days was 11.07 +/- 1.27 gm/dl versus 12.70+/- 1.41 gm/dl (p=0.0000 and infant hematocrit at 90 +/-7 days was 34.13+/-3.93 % versus 39.33 +/-4.88 % in early and delayed clamping respectively (p=0.0000. Conclusion: The timing of cord clamping has no impact on the mean blood loss and duration of third stage of labour. Delayed clamping significantly increases mean venous haemoglobin and hematocrit at 90 +/-7 days without increasing NICU admissions. [Int J Reprod Contracept Obstet Gynecol 2015; 4(4.000: 1103-1108

  14. Direct Torque Control for Three-Level Neutral Point Clamped Inverter-Fed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    M. K. Sahu

    2012-04-01

    Full Text Available Direct torque control (DTC is a control technique in AC drive systems to obtain high performance torque control. The classical DTC drive contains a pair of hysteresis comparators and suffers from variable switching frequency and high torque ripple. These problems can be solved by using space vector depending on the reference torque and flux. In this paper the space vector modulation technique is applied to the three-level Neutral Point Clamped (NPC inverter control in the proposed DTC-based induction motor drive system, resulting to a significant reduce of torque ripple. Three-level neutral point clamped inverters have been widely used in medium voltage applications. This type of inverters have several advantages over standard two-level VSI, such as greater number of levels in the output voltage waveforms, less harmonic distortion in voltage and current waveforms and lower switching frequencies. This paper emphasizes the derivation of switching states using the Space Vector Pulse Width Modulation (SVPWM technique. The control scheme is implemented using Matlab/Simulink. Experimental results using dSPACE validate the steady-state and the dynamic performance of the proposed control strategy.

  15. Testing of Diode-Clamping in an Inductive Pulsed Plasma Thruster Circuit

    Science.gov (United States)

    Toftul, Alexandra; Polzin, Kurt A.; Martin, Adam K.; Hudgins, Jerry L.

    2014-01-01

    Testing of a 5.5 kV silicon (Si) diode and 5.8 kV prototype silicon carbide (SiC) diode in an inductive pulsed plasma thruster (IPPT) circuit was performed to obtain a comparison of the resulting circuit recapture efficiency,eta(sub r), defined as the percentage of the initial charge energy remaining on the capacitor bank after the diode interrupts the current. The diode was placed in a pulsed circuit in series with a silicon controlled rectifier (SCR) switch, and the voltages across different components and current waveforms were collected over a range of capacitor charge voltages. Reverse recovery parameters, including turn-off time and peak reverse recovery current, were measured and capacitor voltage waveforms were used to determine the recapture efficiency for each case. The Si fast recovery diode in the circuit was shown to yield a recapture efficiency of up to 20% for the conditions tested, while the SiC diode further increased recapture efficiency to nearly 30%. The data presented show that fast recovery diodes operate on a timescale that permits them to clamp the discharge quickly after the first half cycle, supporting the idea that diode-clamping in IPPT circuit reduces energy dissipation that occurs after the first half cycle

  16. A Clamped Be Window for the Dump of the HiRadMat Experiment at CERN

    CERN Document Server

    Delonca, M; Grenier, D; Maglioni, C; Sarrio Martinez, A

    2012-01-01

    At CERN, the High Radiation to Materials facility (HiRadMat) is designed to test accelerator components under the impact of high-intensity pulsed beams and will start operation in 2012. In this frame an LHC TED-type dump was installed at the end of the line, working in nitrogen overpressure, and a 254μm-thick beryllium window was placed as barrier between the inside of the dump and the external atmosphere. Because of the special loading conditions, a clamped window design was especially developed, optimized and implemented, the more standard welded window not being suitable for such loads. Considering then the clamping force and the applied differential pressures, the stresses on the window components were carefully evaluated thanks to empirical as well as numerical models, to guarantee the structural integrity of the beryllium foil. This paper reports on choices and optimizations that led to the final design, presenting also comparative results from different solutions and the detailed results for the adopt...

  17. Mechanically clamped PZT ceramics investigated by First-order reversal curves diagram

    Directory of Open Access Journals (Sweden)

    Laurentiu Stoleriu

    2010-09-01

    Full Text Available The First Order Reversal Curves (FORC diagrams method was developed for characterizing the switching properties of ferroelectrics. In the present paper, the FORC method was applied for hard Pb(Zr,TiO3 ceramics with symmetric and asymmetric clamping. An ideal high-oriented single-crystalline ferroelectric with rectangular P(E loop would be characterised by a delta-function FORC distribution, while real ferroelectrics and mostly the polycrystalline ceramics show dispersed FORC distributions. All the investigated ceramics show FORC distributions with non-Gaussian shape, slightly elongated along the coercitive axis, meaning a high dispersion of the energy barriers separating the two bi-stable polarizations ±P. The degree of dispersion is enhanced by clamping. The maximum FORC coercivity is located at ~ (1.9-2 MV/m for all the hard ceramics. The FORC cycling experiment causes the reversal of the initial poling and result in a positive/negative bias on the FORC diagrams. According to the observed features, it results that FORC coercivity is more related to the nature of the material, while the bias field is more sensitive to the electrical and mechanical boundary conditions in which the ferroelectric ceramics evolves while switching.

  18. MODELING, VALIDATION AND OPTIMAL DESIGN OF THE CLAMPING FORCE CONTROL VALVE USED IN CONTINUOUSLY VARIABLE TRANSMISSION

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yunshan; LIU Jin'gang; CAI Yuanchun; ZOU Naiwei

    2008-01-01

    Associated dynamic performance of the clamping force control valve used in continuously variable transmission (CVT) is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm (GA) with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.Key words: Dynamic modeling Optimal design Genetic algorithm Clamping force control valve Continuously variable transmission (CVT)

  19. Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy

    DEFF Research Database (Denmark)

    Olsen, M H; Andersen, U B; Wachtell, K;

    1999-01-01

    We wanted to investigate whether time to steady state was reached within 2 h of insulin infusion during isoglycemic hyperinsulinemic clamp, comparing the glucose uptake index (M/IG) with Bergman's insulin sensitivity index (Sip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic...... hyperinsulinemic clamp in 26 young, healthy subjects and 43 elderly patients with unmedicated essential hypertension and left ventricular hypertrophy. The 3-h Sip correlated strongly with the 2-h M/IG in the patients (r = 0.88, p <0.001) as well as in the healthy subjects (r = 0.96, p <0.001) with relatively...... narrow limits of agreement in the patients. However, during the third hour of insulin infusion, M/IG (10.0 vs 12.21(2) x kg(-1) x min(-1) x mmol(-1), p <0.001) as well as Sip (7.1 vs 9.41(2) x kg(-1) x min(-1) x mmol(-1), p <0.001) increased significantly in the patients, but not in the healthy subjects...

  20. High Performance ZVT with Bus Clamping Modulation Technique for Single Phase Full Bridge Inverters

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yinglai; Ayyanar, Raja

    2016-03-20

    This paper proposes a topology based on bus clamping modulation and zero-voltage-transition (ZVT) technique to realize zero-voltage-switching (ZVS) for all the main switches of the full bridge inverters, and inherent ZVS and/or ZCS for the auxiliary switches. The advantages of the strategy include significant reduction in the turn-on loss of the ZVT auxiliary switches which typically account for a major part of the total loss in other ZVT circuits, and reduction in the voltage ratings of auxiliary switches. The modulation scheme and the commutation stages are analyzed in detail. Finally, a 1kW, 500 kHz switching frequency inverter of the proposed topology using SiC MOSFETs has been built to validate the theoretical analysis. The ZVT with bus clamping modulation technique of fixed timing and adaptive timing schemes are implemented in DSP TMS320F28335 resulting in full ZVS for the main switches in the full bridge inverter. The proposed scheme can save up to 33 % of the switching loss compared with no ZVT case.

  1. Indirect Field Oriented Control for Five Phase Three Level Neutral Point Clamped Inverter Fed PMSM Drive

    Directory of Open Access Journals (Sweden)

    S. Sengottaian

    2015-08-01

    Full Text Available This study deals with a five phase three level Neutral Point Clamped (NPC inverter fed PMSM drive application. The motor performances depend upon mathematical model so the parameters vary are: noise, common mode voltage, flux variation and harmonic levels of the inverter or motor. Voltage saturation is one of the major problems of a motor which occurs due to speed oscillations, more current fluctuations. This problem can be solved by using PWM technique depends on the reference motor torque and flux. In this study Indirect Field Oriented Control (IFOC NPC inverter is suggested to reduce the voltage saturation. The three level neutral point clamped inverter is widely used for medium and high level applications. Compared with standard two level inverter, this type of NPC inverters have more merits. It generates greater number of levels output waveform in lower harmonic content at the same switching frequency and less voltage stress across the semiconductor switches; finally motor performance and control schemes are verified by using MATLAB/SIMULINK.

  2. Estimating residual stress, curvature and boundary compliance of doubly clamped MEMS from their vibration response

    International Nuclear Information System (INIS)

    Structural parameters of doubly clamped microfabricated beams such as initial curvature, boundary compliance, thickness and mean residual stress are often critical to the performance of microelectromechanical systems (MEMS) and need to be estimated as a part of quality control of the microfabrication process. However, these parameters couple and influence many metrics of device response and thus are very difficult to disentangle and estimate using conventional methods such as the M-test, static mechanical tests, pull-in measurements or dynamic mechanical tests. Here we present a simple, non-destructive experimental method to extract these parameters based on the non-contact measurement of the natural frequencies of the lowest few eigenmodes of the microfabricated beam, and knowledge of Young's modulus and plan dimensions of the beam alone. The method exploits the fact that certain eigenmodes are insensitive to some of these structural parameters which enable a convenient decoupling and estimation of the parameters. As a result, the method does not require complicated finite element analysis, is insensitive to the gap height and introduces no contact wear or dielectric charging effects. Experiments are performed using laser Doppler vibrometry to measure the natural frequencies of doubly clamped, nickel, RF-MEMS capacitive switches and the method is applied to extract the residual stress, beam thickness, boundary compliance and post-release curvature. (paper)

  3. Temporary clamping of bilateral external carotid arteries for surgical excision of a complex dural arteriovenous fistula

    Directory of Open Access Journals (Sweden)

    Shih-Chieh Shen

    2014-01-01

    Full Text Available Background: Some complex dural arteriovenous fistulas (DAVFs are lesions that typically have numerous arterial feeders. Surgery, including resection of fistulas or skeletonization of the diseased sinus, is still one of the important treatments for these lesions. However, major blood loss is usually encountered during craniotomy because of abundant arterial feeders from the scalp and transosseous vessels. We present a novel approach for obliteration of the fistulas with less blood loss. Methods: Our first case was a 52-year-old male who suffered from syncope and seizure. Cerebral digital subtraction angiography (DSA revealed complex DAVFs with numerous arterial feeders from bilateral external carotid arteries (ECAs and drainage into the superior sagittal sinus with cerebral venous reflux. The second case was a 48-year-old male presenting with chronic headache. His DSA also showed complex DAVFs along the superior sagittal sinus with cerebral venous reflux. In both cases, we performed the surgical procedure to obliterate the pathological fistulas after temporary clamping of bilateral ECAs and noted less blood loss than in the conventional surgery. Results: The follow-up DSA showed successful obliteration of the complex DAVFs on the first case and partial improvement on the second case followed by transarterial embolization (TAE. The symptoms of the both patients were relieved after surgery with good recovery. Conclusion: Temporary clamping of bilateral ECAs can improve the safety and ease the surgical excision for complex DAVFs. By using this technique, neurosurgeons can deal with aggressive DAVFs more confidently and calmly.

  4. A Clamped Be Window for the Dump of the HiRadMat Experiment at CERN

    CERN Document Server

    Delonca, M; Grenier, D; Maglioni, C; Sarrio Martinez, A

    2012-01-01

    At CERN, the High Radiation to Materials facility (HiRadMat) is designed to test accelerator components under the impact of high-intensity pulsed beams and will start operation in 2012. In this frame an LHC TED-type dump was installed at the end of the line, working in nitrogen over-pressure, and a 254μm-thick beryllium window was placed as barrier between the inside of the dump and the external atmosphere. Because of the special loading conditions, a clamped window design was especially developed, optimized and implemented, the more standard welded window not being suitable for such loads. Considering then the clamping force and the applied differential pressures, the stresses on the window components were carefully evaluated thanks to empirical as well as numerical models, to guarantee the structural integrity of the beryllium foil. This paper reports on choices and optimizations that led to the final design, presenting also comparative results from different solutions and the detailed results for the adop...

  5. Interleukin-2 activity can be fine tuned with engineered receptor signaling clamps.

    Science.gov (United States)

    Mitra, Suman; Ring, Aaron M; Amarnath, Shoba; Spangler, Jamie B; Li, Peng; Ju, Wei; Fischer, Suzanne; Oh, Jangsuk; Spolski, Rosanne; Weiskopf, Kipp; Kohrt, Holbrook; Foley, Jason E; Rajagopalan, Sumati; Long, Eric O; Fowler, Daniel H; Waldmann, Thomas A; Garcia, K Christopher; Leonard, Warren J

    2015-05-19

    Interleukin-2 (IL-2) regulates lymphocyte function by signaling through heterodimerization of the IL-2Rβ and γc receptor subunits. IL-2 is of considerable therapeutic interest, but harnessing its actions in a controllable manner remains a challenge. Previously, we have engineered an IL-2 "superkine" with enhanced affinity for IL-2Rβ. Here, we describe next-generation IL-2 variants that function as "receptor signaling clamps." They retained high affinity for IL-2Rβ, inhibiting binding of endogenous IL-2, but their interaction with γc was weakened, attenuating IL-2Rβ-γc heterodimerization. These IL-2 analogs acted as partial agonists and differentially affected lymphocytes poised at distinct activation thresholds. Moreover, one variant, H9-RETR, antagonized IL-2 and IL-15 better than blocking antibodies against IL-2Rα or IL-2Rβ. Furthermore, this mutein prolonged survival in a model of graft-versus-host disease and blocked spontaneous proliferation of smoldering adult T cell leukemia (ATL) T cells. This receptor-clamping approach might be a general mechanism-based strategy for engineering cytokine partial agonists for therapeutic immunomodulation. PMID:25992859

  6. A direct proofreader-clamp interaction stabilizes the Pol III replicase in the polymerization mode

    KAUST Repository

    Jergic, Slobodan

    2013-02-22

    Processive DNA synthesis by the αÉ"θ core of the Escherichia coli Pol III replicase requires it to be bound to the β 2 clamp via a site in the α polymerase subunit. How the É" proofreading exonuclease subunit influences DNA synthesis by α was not previously understood. In this work, bulk assays of DNA replication were used to uncover a non-proofreading activity of É". Combination of mutagenesis with biophysical studies and single-molecule leading-strand replication assays traced this activity to a novel β-binding site in É" that, in conjunction with the site in α, maintains a closed state of the αÉ"θ-β 2 replicase in the polymerization mode of DNA synthesis. The É"-β interaction, selected during evolution to be weak and thus suited for transient disruption to enable access of alternate polymerases and other clamp binding proteins, therefore makes an important contribution to the network of protein-protein interactions that finely tune stability of the replicase on the DNA template in its various conformational states. © 2013 European Molecular Biology Organization.

  7. Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy

    DEFF Research Database (Denmark)

    Olsen, M H; Andersen, U B; Wachtell, K;

    1999-01-01

    We wanted to investigate whether time to steady state was reached within 2 h of insulin infusion during isoglycemic hyperinsulinemic clamp, comparing the glucose uptake index (M/IG) with Bergman's insulin sensitivity index (Sip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic...... narrow limits of agreement in the patients. However, during the third hour of insulin infusion, M/IG (10.0 vs 12.21(2) x kg(-1) x min(-1) x mmol(-1), p <0.001) as well as Sip (7.1 vs 9.41(2) x kg(-1) x min(-1) x mmol(-1), p <0.001) increased significantly in the patients, but not in the healthy subjects....... Because the 2-h M/IG correlated strongly with the 3-h Sip with relatively narrow limits of agreement, it is a good measure of insulin sensitivity. However, a 2-h clamp results in lower insulin sensitivity values in elderly, hypertensive patients due to the fact that steady state is not reached...

  8. Automatic Calibration of Frequency Compensation System in Computer-Controlled Patch-Clamp Amplifier

    Directory of Open Access Journals (Sweden)

    Jun Xion

    2007-01-01

    Full Text Available Computer-controlled patch-clamp amplifier is a digitally controlled analog device used to record the cellular ion channel currents in electrophysiology research. The inherent bandwidth and performance of the headstage is limited by the stray capacitance and distributed capacitance across the feedback resistors. In order to effectively improve the performance of the headstage, the paper advanced a simplified automatic calibration method of frequency compensation system in resistor-feedback patch-clamp amplifier. The dynamic model of headstage was approximate as a two poles and one zero system in the transfer function by experience and test results, so the dynamic characteristics of the headstage were obtained employing least squares parameter estimation algorithm. Further more, the compensation parameter of high frequency booster can be estimated by the time constant of main pole of headstage. And automatic adjustment of the parameters in transient response correction stage was performed as a least squares fitting problem. The software routine running on the host computer conducted all operations of frequency compensation. Experimental results demonstrate that the simplified automatic calibration method can substantially extend the bandwidth and minimize step response error of headstage.

  9. A patch-clamp study on human sperm Cl-channel reassembled into giant liposome

    Institute of Scientific and Technical Information of China (English)

    Jun-Ping BAI; Yu-Liang SHI

    2001-01-01

    Aim: To record the single-channel currents and characterize the electrophysiological properties of the Cl-channels in human sperm membrane. Methods: The membrane proteins extracted from the human sperm were reassembled into liposome bilayer, and the liposomes were fused into giant liposomes with a diameter more than 10 μm by dehydrationrehydration procedure. The giant liposomes were used to study the Cl-channel activities by patch-clamp technique.Results: By patch clamping the giant liposome in an asymmetric NMDG (N-methyl-D-glucamine)-Cl (bath 100//pipette 200 mmol/L) solution system, three kinds of single-channel events with unit conductances of (74.1 ± 8.3) pS,( 117.0 ± 5.7) pS and ( 144.7 ±+ 4.5 ) pS, respectively, were detected. Their activities were voltage-dependent and all manner. By constructing the open and close dwell time distribution histograms and then fitting them with exponential function, two time constants were obtained in both the open and the close states. The burst activity and conductance substate of the channels were observed. Conclusion: There exist three kinds of Cl-channels with different conductance in human sperm membrane at least.

  10. Effect of organometallic clamp properties on the apparent diversity of tensile response of nanowires

    International Nuclear Information System (INIS)

    The influence of the experimental boundary conditions used for tensile testing of individual nanowires on the measured apparent mechanical response is reported. Using a microelectromechanical platform designed for in situ tensile testing, in combination with digital image correlation of sequences of scanning electron microscope images, the mechanical behavior of single crystalline Si, Pd, and Ge2Sb2Te5 nanowires was measured during load–unload cycles. In situ testing enables direct determination of the nanowire strain. Comparison of the direct strain with common metrics for apparent strain that include any compliance or slipping of the clamping materials (electron-beam induced Pt-containing deposits) highlights several different artifacts that may be manifested. Calculation of the contact stiffness is thus enabled, providing guidelines for both proper strain measurement and selection of clamping materials and geometries that facilitate elucidation of intrinsic material response. Our results suggest that the limited ability to tailor the stiffness of electron-beam induced deposits results from the predominance of the organic matrix in controlling its mechanical properties owing to relatively low Pt content and sparse morphology. (paper)

  11. Quantification of material slippage in the iliotibial tract when applying the partial plastination clamping technique.

    Science.gov (United States)

    Sichting, Freddy; Steinke, Hanno; Wagner, Martin F-X; Fritsch, Sebastian; Hädrich, Carsten; Hammer, Niels

    2015-09-01

    The objective of this study was to evaluate the potential of the partial plastination technique in minimizing material slippage and to discuss the effects on the tensile properties of thin dense connective tissue. The ends of twelve iliotibial tract samples were primed with polyurethane resin and covered by plastic plates to provide sufficient grip between the clamps. The central part of the samples remained in an anatomically unfixed condition. Strain data of twelve partially plastinated samples and ten samples in a completely anatomically unfixed state were obtained using uniaxial crosshead displacement and an optical image tracking technique. Testing of agreement between the strain data revealed ongoing but markedly reduced material slippage in partially plastinated samples compared to the unfixed samples. The mean measurement error introduced by material slippage was up to 18.0% in partially plastinated samples. These findings might complement existing data on measurement errors during material testing and highlight the importance of individual quantitative evaluation of errors that come along with self-made clamping techniques. PMID:26005842

  12. Laser microsurgery of higher plant cell walls permits patch-clamp access

    Science.gov (United States)

    Henriksen, G. H.; Taylor, A. R.; Brownlee, C.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    1996-01-01

    Plasma membranes of guard cells in epidermal peels of Vicia faba and Commelina communis can be made accessible to a patch-clamp pipet by removing a small portion (1-3 micrometers in diameter) of the guard cell wall using a microbeam of ultraviolet light generated by a nitrogen laser. Using this laser microsurgical technique, we have measured channel activity across plasma membranes of V. faba guard cells in both cell-attached and isolated patch configurations. Measurements made in the inside-out patch configuration revealed two distinct K(+)-selective channels. Major advantages of the laser microsurgical technique include the avoidance of enzymatic protoplast isolation, the ability to study cell types that have been difficult to isolate as protoplasts or for which enzymatic isolation protocols result in protoplasts not amenable to patch-clamp studies, the maintenance of positional information in single-channel measurements, reduced disruption of cell-wall-mediated signaling pathways, and the ability to investigate intercellular signaling through studies of cells remaining situated within tissue.

  13. Enhanced brain release of erythropoietin, cytokines and NO during carotid clamping.

    Science.gov (United States)

    Carelli, Stephana; Ghilardi, Giorgio; Bianciardi, Paola; Latorre, Elisa; Rubino, Federico; Bissi, Marina; Di Giulio, Anna Maria; Samaja, Michele; Gorio, Alfredo

    2016-02-01

    Although effective and safe, carotid endarterectomy (CEA) implies a reduced blood flow to the brain and likely an ischemia/reperfusion event. The high rate of uneventful outcomes associated with CEA suggests the activation of brain endogenous protection mechanisms aimed at limiting the possible ischemia/reperfusion damage. This study aims at assessing whether CEA triggers protective mechanisms such as brain release of erythropoietin and nitric oxide. CEA was performed in 12 patients; blood samples were withdrawn simultaneously from the surgically exposed ipsilateral jugular and leg veins before, during (2 and 40 min) and after clamp removal (2 min). Plasma antioxidant capacity, carbonylated proteins, erythropoietin, nitrates and nitrites (NOx) were determined. No changes in intraoperative EEG, peripheral and transcranial blood oxygen saturation were detectable, and no patients showed any neurologic sign after the intervention. Antioxidant capacity and protein carbonylation in plasma were unaffected. Differently, erythropoietin, VEGF, TNF-α and NOx increased during clamping in the jugular blood (2 and 40 min), while no changes were observed in the peripheral circulation. These results show that blood erythropoietin, VEGF, TNF-α, and NOx increased in the brain during uncomplicated CEA. This may represent an endogenous self-activated neuroprotective mechanism aimed at the prevention of ischemia/reperfusion damage. PMID:26494654

  14. Attachment ability of a clamp-bearing fish parasite, Diplozoon paradoxum (Monogenea), on gills of the common bream, Abramis brama.

    Science.gov (United States)

    Wong, Wey-Lim; Gorb, Stanislav N

    2013-08-15

    Monogeneans, which are mainly fish ectoparasites, use various types of haptoral (posterior) attachment apparatus to secure their attachment onto their hosts. However, it remains unclear how strongly a monogenean can attach onto its host. In the present study, we aimed for the first time to (1) measure pull-off forces required to detach a pair of clamp-bearing monogeneans, Diplozoon paradoxum, from gills of Abramis brama and (2) determine the contribution of muscles to the clamp movements. A mean force of 6.1±2.7 mN (~246 times the animals' weight) was required to dislodge a paired D. paradoxum vertically from the gills. There were significant differences (Pfiltered lake water (20.16±8.63 μm). This suggests that the closing of the clamps is probably not due to the continuous contraction of extrinsic muscles but is caused by the elasticity of the clamp material and that muscle activity is required for clamp opening. PMID:23580722

  15. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers

    International Nuclear Information System (INIS)

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class

  16. del Nido versus St. Thomas Cardioplegia Solutions: A Single-Center Retrospective Analysis of Post Cross-Clamp Defibrillation Rates.

    Science.gov (United States)

    Buel, Shane T; Striker, Carrie Whittaker; O'Brien, James E

    2016-06-01

    There are many cardioplegia solutions currently in use for pediatric cardiopulmonary bypass (CPB). The most common being del Nido solution. Another common cardioplegia solution used for pediatric CPB is St. Thomas. In October 2014, Children's Mercy Kansas City changed from the use of modified St. Thomas to del Nido. This study compared rates of post cross-clamp fibrillation requiring defibrillation between del Nido solution and modified St. Thomas solution stratified by weight at Children's Mercy Kansas City. This retrospective study consisted of 394 patients who underwent cardiac surgery requiring cardioplegia between January 1, 2014 and July 31, 2015. The outcome measured was defibrillation upon cross-clamp removal. Statistical significance was determined using Fishers exact test with a two-sided significance level of .05. Incidence of defibrillation post cross-clamp removal was 4.4% in the del Nido group and 26.8% in the St. Thomas group (p 60-kg category had an incidence of defibrillation of 16.7% in the del Nido group and 63% in the St. Thomas group (p < .0623). This study demonstrates a 6-fold decrease in the overall rate of defibrillation post cross-clamp removal between St. Thomas and del Nido cardioplegia solutions. Analyses of weight stratifications demonstrate a decrease in the rate of defibrillation post cross-clamp removal in all categories within the del Nido group. PMID:27578896

  17. Temporary Inferior Vena Cava Filters: How Do We Move Forward?

    Science.gov (United States)

    Arous, Edward J; Messina, Louis M

    2016-05-01

    Despite their widespread use, the indications for the selective use of temporary inferior vena cava (IVC) filters remains uncertain with few trials supporting their use. Additionally, the risks of long-term temporary IVC filter insertion are being increasingly discussed amongst the mainstream media and through multiple class action lawsuits. Retrievable IVC filters were specifically designed to have a less secure implantation in order to facilitate retrieval. However, multiple reports have demonstrated significant filter-related complications, most commonly related to duration of implantation. Furthermore, the risk is not isolated to one manufacturer alone. The incidence of filter-related complications is linearly related to its duration of time on the market. Currently, the FDA recommends that IVC filters be removed within 25-54 days of their implantation. Unfortunately, little evidence exists to show that this recommendation is followed routinely. Recently, the PRESERVE Trial (NCT02381509) was initiated as a multicenter non-randomized open label study to determine the safety and effectiveness of commercially available IVC filters (both temporary and permanent) in individuals who require mechanical prophylaxis against pulmonary embolism. Until such evidence is developed, temporary IVC filters should be implanted based on best available evidence and routinely removed within the guidelines of the FDA of 25-54 days. A fair question at this point is whether the design features themselves that are required to manufacture a low profile removable IVC filter can achieve effective prophylaxis against pulmonary embolism at a low rate of short and long-term complications. PMID:27012891

  18. Determinants of survival after inferior vena cava trauma.

    Science.gov (United States)

    Kuehne, J; Frankhouse, J; Modrall, G; Golshani, S; Aziz, I; Demetriades, D; Yellin, A E

    1999-10-01

    Inferior vena cava (IVC) injuries continue to be associated with mortality rates of 21 to 66 per cent despite advances in prehospital, surgical, and critical care. The purpose of this study was to evaluate outcome of patients with IVC injury after treatment at a major urban trauma center and to identify factors predictive of survival. Between 1989 and 1995, 158 patients presented to the Los Angeles County + University of Southern California Medical Center with IVC injuries. One hundred thirty-six patient records were available for review, and 69 data points were collected and analyzed. Mean age was 26 years (range, 6-54), and 122 (90%) patients were male. Mechanism of injury included gunshot in 88 (65%) patients, stab in 23 (17%) patients, shotgun in 7 (5%) patients, and blunt trauma in 18 (13%) patients. The mean Injury Severity Score was 25. Seventy (52%) patients were hypotensive. Eleven (8%) patients died before surgical intervention, and 25 (18%) patients died before operative repair. Repair (79), ligation (20), or observation (1) was accomplished in 100 (74%) patients. Overall survival was 48 per cent and 65 per cent in the 100 patients surviving to operative repair, including 5 of 20 patients requiring IVC ligation. Significant differences (Pthoracotomy, blood loss, level of injury, tamponade, and associated aortic injury. Logistic regression analysis identified hypotension, anatomic level of injury, and associated aortic injury as significant predictors of outcome (P = 0.001). Survival is predominantly determined by severity and anatomic accessibility of the IVC injury and by the absence of associated major vascular injuries. Ligation may control otherwise exsanguinating injuries and should be considered early in the management of complex injuries. PMID:10515547

  19. "Mini-Flow-Through" Deep Inferior Epigastric Perforator Flap for Breast Reconstruction with Preservation of Both Internal Mammary and Deep Inferior Epigastric Vessels

    Science.gov (United States)

    Sugawara, Jun; Yasumura, Kazunori; Mikami, Taro; Kobayashi, Shinji; Maegawa, Jiro

    2015-01-01

    This procedure was developed for preservation of the rectus muscle components and deep inferior epigastric vessel after deep inferior epigastric perforator (DIEP) flap harvesting. A 53-year-old woman with granuloma caused by silicone injection underwent bilateral nipple-sparing mastectomies and immediate reconstruction with "mini-flow-through" DIEP flaps. The flaps were dissected based on the single largest perforator with a short segment of the lateral branch of the deep inferior epigastric vessel that was transected as a free flap for breast reconstruction. The short segments of the donor deep inferior epigastric vessel branch are primarily end-to-end anastomosed to each other. A short T-shaped pedicle mini-flow-through DIEP flap is interposed in the incised recipient's internal mammary vessels with two arterial and four concomitant venous anastomoses. Although it requires multiple vascular anastomoses and a short pedicle for the flap setting, the mini-flow-through DIEP flap provides a large pedicle caliber, enabling safer microsurgical anastomosis and well-vascularized tissue for creating a natural breast without consuming time or compromising the rectus muscle components and vascular flow of both the deep inferior epigastric and internal mammary vessels. PMID:26618128

  20. Non-inferiority clinical trials: Practical issues and current regulatory perspective

    Directory of Open Access Journals (Sweden)

    Sandeep K Gupta

    2011-01-01

    Full Text Available Non-inferiority clinical trials are being performed with an increasing frequency now-a-days, because it helps in finding a new treatment that have approximately the same efficacy, but may offer other benefits such as better safety profile. Non-inferiority clinical trials aim to demonstrate that the test product is no worse than the comparator by more than a pre-specified small amount. There are several fundamental differences between non-inferiority and superiority trials. Some practical issues concerning the non-inferiority trials are assay sensitivity, choice of the non-inferiority margin, sample size estimation, choice of active-control, and analysis of non-inferiority clinical trials. For serious infections such as hospital-acquired bacterial pneumonia/ventilator-associated bacterial pneumonia, community-acquired bacterial pneumonia, and acute bacterial skin and skin structure infections, the United States Food and Drug Administration (US FDA has recently recommended that it is possible to define a reliable and consistent estimate of the efficacy of active treatment relative to placebo from available data, which can serve as the basis for defining a new inferiority margin for an active-controlled, non-inferiority trial. But for some indications with a high rate of resolution without antibacterial drug therapy such as acute bacterial sinusitis (ABS, acute bacterial exacerbation of chronic bronchitis (ABECB, and acute bacterial otitis media (ABOM, the US FDA has recommended that the available data will not support the use of a non-inferiority design and other trial designs (i.e., superiority designs should be used to provide the evidence of effectiveness in these three indications.

  1. Occipital artery-to-posterior inferior cerebellar artery anastomosis with multiple-layer dissection of suboccipital muscles under a reverse C-shaped skin incision.

    Science.gov (United States)

    Katsuno, Makoto; Tanikawa, Rokuya; Uemori, Genki; Kawasaki, Kazutsune; Izumi, Naoto; Hashimoto, Masaaki

    2015-06-01

    Although occipital artery (OA)-to-posterior inferior cerebellar artery (PICA) anastomosis is the most familiar reconstruction for posterior cerebral circulation, the procedure is considered difficult because of the anatomical complex course of OA and the depth of the operative field at the anastomosis site. Therefore, we attempted a safe and reliable method for OA-to-PICA anastomosis under multiple-layer dissection of suboccipital muscles and a reverse C-shaped skin incision. We reviewed the clinical records of patients who underwent OA-to-PICA anastomosis in our institute, and report the outcome with special emphasis on graft patency and surgical complications. Nine patients are described. In one patient the bypass was accomplished at the cortical segment of the PICA and in all others at the caudal loop. The average time for de-clamping the PICA was 29 min and 29 s. Although the overall graft patency rate was 100%, one patient showed a new medulla infarction at the time of post-operatory three-dimensional computed tomography angiography. Besides a secure OA-to-PICA anastomosis, this technique allows safe harvest of the OA and the creation of a shallow and wide anastomosis field. PMID:25633907

  2. A Hybrid Cascade Converter Topology With Series-Connected Symmetrical and Asymmetrical Diode-Clamped H-Bridge Cells

    DEFF Research Database (Denmark)

    Nami, Alireza; Zare, Firuz; Ghosh, Arindam; Blaabjerg, Frede

    2011-01-01

    A novel H-bridge multilevel pulsewidth modulation converter topology based on a series connection of a high-voltage diode-clamped inverter and a low-voltage conventional inverter is proposed in this paper. A dc link voltage arrangement for the new hybrid and asymmetric solution is presented to have...... configuration to approach a very low total harmonic distortion of voltage and current, which leads to the possible elimination of the output filter. Regarding the proposed configuration, a new cascade inverter is verified by cascading an asymmetrical diode-clamped inverter, in which 19 levels can be synthesized...... in output voltage with the same number of components. To balance the dc link capacitor voltages for the maximum output voltage resolution as well as synthesize asymmetrical dc link combination, a new multi-output boost converter is utilized at the dc link voltage of a seven-level H-bridge diode-clamped...

  3. Comparison: Simulation and Experimental Characterisation of an all-Optical Gain-Clamped Erbium-Doped Fibre Amplifier

    Directory of Open Access Journals (Sweden)

    T. Subramaniam M. A. Mahdi P. Poopalan, and H. Ahmad

    2012-10-01

    Full Text Available This paper presents the GC-EDFA characteristics comparison between the simulated results (using EDFA_Design software and experimental results. The comparisons reveal the usefulness of the software in simulating the behaviour of an all-optical GC-EDFA system. Comparisons are made for values obtained from the system operated at high laser power, in order to highlight the differences between the experimental and simulated values. The main objective for this comparison is to prove the capability of the software in simulating the gain-clamped system. Therefore, the software can be used to test new configurations, aimed at improvising current gain-clamped EDFA performances.Keywords optical, gain-clamping, erbium, fibre amplifier, simulation, experiment

  4. Negligible substrate clamping effect on piezoelectric response in (111)-epitaxial tetragonal Pb(Zr, Ti)O{sub 3} films

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Tomoaki, E-mail: t-yamada@nucl.nagoya-u.ac.jp [Department of Materials, Physics and Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Yasumoto, Jun; Ito, Daisuke; Yoshino, Masahito; Nagasaki, Takanori [Department of Materials, Physics and Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Sakata, Osami [Synchrotron X-ray Station at SPring-8 and Synchrotron X-ray Group, National Institute for Materials Science, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Department of Innovative and Engineered Material, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Imai, Yasuhiko [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kiguchi, Takanori [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Shiraishi, Takahisa; Shimizu, Takao; Funakubo, Hiroshi [Department of Innovative and Engineered Material, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)

    2015-08-21

    The converse piezoelectric responses of (111)- and (001)-epitaxial tetragonal Pb(Zr{sub 0.35}Ti{sub 0.65})O{sub 3} [PZT] films were compared to investigate the orientation dependence of the substrate clamping effect. Synchrotron X-ray diffraction (XRD) and piezoelectric force microscopy revealed that the as-grown (111)-PZT film has a polydomain structure with normal twin boundaries that are changed by the poling process to inclined boundaries, as predicted by Romanov et al. [Phys. Status Solidi A 172, 225 (1999)]. Time-resolved synchrotron XRD under bias voltage showed the negligible impact of substrate clamping on the piezoelectric response in the (111)-PZT film, unlike the case for (001)-PZT film. The origin of the negligible clamping effect in the (111)-PZT film is discussed from the viewpoint of the elastic properties and the compensation of lattice distortion between neighboring domains.

  5. Interdependência da lateralidade com a estabilidade articular do membro inferior

    OpenAIRE

    Atalaia, Tiago João Viegas

    2015-01-01

    A presença de dominância de um membro inferior em relação ao seu contra lateral, leva a esperar a existência de diferenças funcionais. O objetivo desta tese visou a identificação de diferenças entre membro inferior dominante (DOM) e não dominante (NDOM), no que diz respeito à estabilidade articular (JS), avaliada por medidas de rigidez dinâmica articular (DJS), rigidez vertical (KVERT) ou rigidez de membro inferior (KLEG). A integração de elementos conceptuais e metodológicos foi desenvolvida...

  6. Inferior vena cava leiomyosarcoma confirmed by catheter suction biopsy during digital subtraction angiography.

    Science.gov (United States)

    Wei, Ning; Xu, Xiang-Dong; Xu, Hao; Zu, Mao-Heng

    2014-01-01

    Leiomyosarcoma of vascular origin is a rare disease and most cases arise in the inferior vena cava. Inferior vena cava leiomyosarcoma (IVCLMS) usually presents in females in their sixth decade of life. The clinical symptoms are often non-specific and the diagnosis is often delayed. Current imaging techniques can accurately differentiate inferior vena cava neoplasms from other non-neoplastic lesions. However, definitive diagnosis of IVCLMS needs histologic evidence. We report a case of IVCLMS in a 61-year old Chinese woman. This is the first IVCLMS case confirmed by catheter suction biopsy during digital subtraction angiography. PMID:25232438

  7. Control de pacientes con problemas isquémicos en miembros inferiores

    OpenAIRE

    Armero Barranco, David; Alcaraz Baños, Miguel; Bernal Páez, F.L.; Felices Abad, J.M.

    2002-01-01

    La isquemia de miembros inferiores, es una patología frecuente entre los pacientes que acuden a una unidad de Radiología Vascular para ser diagnosticados y/o tratados. La exploración mediante doppler lineal (realizada en nuestro centro por el personal de enfermería) para problemas circulatorios en miembros inferiores, junto con la angiografía también de miembros inferiores, son las exploraciones que mas frecuentemente realizamos en estos pacientes. Objetivo: Se pretende determinar un posi...

  8. Stress-stimulated current of dry rocks with constant clamping stress

    Science.gov (United States)

    Dahlgren, R. P.; Vanderbilt, V. C.; Johnston, M. J. S.

    2014-12-01

    A set of nominally dry rocks (gabbro, granite, limestone, marble, and sandstone) were subjected to asymmetric loading with a large hydraulic press. A pair of precision platens made from 1018 low carbon steel were used to apply uniaxial compressive stress (σ) to the sample, via a thin electrical insulator made from ultra-high molecular weight (UHMW) polyethylene. Self-adhesive copper electrodes were applied and burnished on the end faces and the stress-stimulated current (SSC) was monitored using a Keithley 617 instrument. A preload stress level of 5.5 MPa was applied to firmly clamp the assembly throughout the experiment. From this baseline, σ was increased to 22.25 MPa and held for 100 seconds before returning to the clamping stress level. This loading profile was repeated for four or more cycles, with a stress rate on the order of 5MPa/sec. After the first load cycle, the SSC transients (and SSV offsets) are reversible when σ returned to its baseline level. All samples showed alternating unipolar SSC transients at the beginning and end of each load cycle. SSC from limestone, Westerly granite and marble were at, or below, the measurement limit (±1 pA). All other samples except sandstone showed a negative SSC with increasing stress. For stress-stimulated voltage (SSV) there was a richer variety of transients observed such as unipolar, bipolar and more complex transient dynamics. Limestone was the only sample tested with no SSV transients although this particular rock had a major calcite inclusion in the sample. White granite tended to have the least stable SSC and SSV values. Of the six different rock samples tested under identical conditions, the SSC and SSV observed were not greater than -15 pA, presumably due to improved experimental procedures. The response for rocks with semiconductor properties (gabbro, granite) is the same as those without semiconductor properties (limestone, marble), although the values for marble were below the noise. For repetitive

  9. Pars plana vitrectomy for the repair of primary, inferior rhegmatogenous retinal detachment associated to inferior breaks. A comparison of a 25-gauge versus a 20-gauge system

    OpenAIRE

    dell’Omo, Roberto; Barca, Francesco; Tan, H. Stevie; Bijl, Heico M.; Oberstein, Sarit Y Lesnik; Mura, Marco

    2012-01-01

    Background To compare anatomical, functional outcomes and complications of high-speed 25-gauge (G) pars plana vitrectomy (PPV) versus 20-G PPV for the management of primary inferior rhegmatogenous retinal detachment (RRD) associated to inferior breaks/holes. Methods Eighty-five eyes from 85 patients with a minimum follow-up of 3 months were retrospectively evaluated. Forty-one patients underwent 25-G and 44 patients underwent 20-G PPV. All patients underwent PPV with fluid-air exchange, sulfu...

  10. An Experimental Method for Measuring the Clamping Force in Double Lap Simple Bolted and Hybrid (Bolted-Bonded) Joints

    OpenAIRE

    Goldarag, Firooz Esmaeili; Barzegar, Sajjad; Babaei, Alireza

    2015-01-01

    In this research, an experimental method for measuring the clamping force as a result of tightening torque in double lap simple bolted and hybrid (bolted-bonded) joints is proposed. Two types of joints, i.e. double lap simple and hybrid (bolted-bonded) joints were prepared for testing. In order to measure the clamping force or pretension resulting from the tightening torque at different applied torques, for both types of joints, a special experimental method was designed using a steel bush th...

  11. A novel latch-up free SCR-LDMOS with high holding voltage for a power-rail ESD clamp

    International Nuclear Information System (INIS)

    The low snapback holding voltage of the SCR-LDMOS device makes it susceptible to latch-up failure, when used in power-rail ESD (electro-static discharge) clamp circuits. In order to eliminate latch-up risk, this work presents a novel SCR-LDMOS structure with an N-type implantation layer to achieve a 17 V holding voltage and a 5.2 A second breakdown current. The device has been validated using TLP measurement analysis and is applied to a power-rail ESD clamp in half-bridge driver ICs. (semiconductor devices)

  12. A novel latch-up free SCR-LDMOS with high holding voltage for a power-rail ESD clamp

    Institute of Scientific and Technical Information of China (English)

    Pan Hongwei; Liu Siyang; Sun Weifeng

    2013-01-01

    The low snapback holding voltage of the SCR-LDMOS device makes it susceptible to latch-up failure,when used in power-rail ESD (electro-static discharge) clamp circuits.In order to eliminate latch-up risk,this work presents a novel SCR-LDMOS structure with an N-type implantation layer to achieve a 17 V holding voltage and a 5.2 A second breakdown current.The device has been validated using TLP measurement analysis and is applied to a power-rail ESD clamp in half-bridge driver ICs.

  13. Nonlinear dynamic behaviors of clamped laminated shallow shells with one-to-one internal resonance

    Science.gov (United States)

    Abe, Akira; Kobayashi, Yukinori; Yamada, Gen

    2007-07-01

    This paper investigates one-to-one internal resonance of laminated shallow shells with rigidly clamped edges. It is assumed that the natural frequencies ω2 and ω3 of two asymmetric (second and third) vibration modes have the relationship ω2≈ ω3. The displacements are expressed by using eigenvectors for linear vibration modes calculated by the Ritz method. Applying Galerkin's procedure to the equation of motion, nonlinear differential equations are derived. By considering the first vibration mode in addition to the two asymmetric vibration modes, quadratic nonlinear terms expressing the interaction between the asymmetric and the first modes appear in the differential equations. Shooting method is used to obtain the steady-state response when the driving frequency Ω is near ω2. The dynamic characteristics of the shells with the internal resonance are discussed.

  14. Fabrication and characterization of GaN nanowire doubly clamped resonators

    Science.gov (United States)

    Maliakkal, Carina B.; Mathew, John P.; Hatui, Nirupam; Rahman, A. Azizur; Deshmukh, Mandar M.; Bhattacharya, Arnab

    2015-09-01

    Gallium nitride (GaN) nanowires (NWs) have been intensely researched as building blocks for nanoscale electronic and photonic device applications; however, the mechanical properties of GaN nanostructures have not been explored in detail. The rigidity, thermal stability, and piezoelectric properties of GaN make it an interesting candidate for nano-electromechanical systems. We have fabricated doubly clamped GaN NW electromechanical resonators on sapphire using electron beam lithography and estimated the Young's modulus of GaN from resonance frequency measurements. For wires of triangular cross section with side ˜90 nm, we obtained values for the Young's modulus to be about 218 and 691 GPa, which are of the same order of magnitude as the values reported for bulk GaN. We also discuss the role of residual strain in the nanowire on the resonant frequency and the orientation dependence of the Young's modulus in wurtzite crystals.

  15. Fabrication of Si-based planar type patch clamp biosensor using silicon on insulator substrate

    International Nuclear Information System (INIS)

    The aim of this paper is to fabricate the planar type patch clamp ion-channel biosensor, which is suitable for the high throughput screening, using silicon-on-insulator (SOI) substrate. The micropore with 1.2 μm diameter is formed through the top Si layer and the SiO2 box layer of the SOI substrate by focused ion beam (FIB). Then the substrate is assembled into the microfluidic circuit. The human embryonic kidney 293 (HEK-293) cell transfected with transient receptor potential vanilloid type 1 (TRPV1) is positioned on the micropore and the whole-cell configuration is formed by the suction. Capsaicin is added to the extracellular solution as a ligand molecule, and the channel current showing the desensitization unique to TRPV1 is measured successfully

  16. Fabrication of Si-based planar type patch clamp biosensor using silicon on insulator substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.L.; Asano, T. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Uno, H. [Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Tero, R. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Suzui, M.; Nakao, S. [Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Kaito, T. [SII NanoTechnology Inc., 36-1, Takenoshita, Oyama-cho, Sunto-gun, Shizuoka, 410-1393 (Japan); Shibasaki, K.; Tominaga, M. [Okazaki Institute for Integrative Bioscience, 5-1, Higashiyama, Myodaiji, Okazaki, 444-8787 (Japan); Utsumi, Y. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2, Koto, Kamigori, Ako-gun, Hyogo, 678-1205 (Japan); Gao, Y.L. [Department of Physics and Astronomy, Rochester University, Rochester, New York 14627 (United States); Urisu, T. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan)], E-mail: urisu@ims.ac.jp

    2008-03-03

    The aim of this paper is to fabricate the planar type patch clamp ion-channel biosensor, which is suitable for the high throughput screening, using silicon-on-insulator (SOI) substrate. The micropore with 1.2 {mu}m diameter is formed through the top Si layer and the SiO{sub 2} box layer of the SOI substrate by focused ion beam (FIB). Then the substrate is assembled into the microfluidic circuit. The human embryonic kidney 293 (HEK-293) cell transfected with transient receptor potential vanilloid type 1 (TRPV1) is positioned on the micropore and the whole-cell configuration is formed by the suction. Capsaicin is added to the extracellular solution as a ligand molecule, and the channel current showing the desensitization unique to TRPV1 is measured successfully.

  17. Harmonic Mitigated Front End Three Level Diode Clamped High Frequency Link Inverter by Using MCI Technique

    Directory of Open Access Journals (Sweden)

    Sreedhar Madichetty

    2014-02-01

    Full Text Available In this paper it proposes a high efficient soft-switching scheme based on zero-voltage-switching (ZVS and zero-current-switching(ZCS principle operated with a simple auxiliary circuit extended range for the front-end isolated DC-AC-DC-AC high power converter with an three phase three level diode clamped multi level inverter by using Minority Charge Carrier inspired optimization technique (MCI with Total Harmonic Distortion(THD,Switching losses, Selective harmonic elimination maintaining with its fundamental as an objective function. Input to the inverter is obtained by the photo voltaic cells and with battery bank. The switching scheme is optimized by MCI technique, analyzed and executed in Matlab and implemented with a digital signal processor (DSP .Experimental results with different loads have observed and shows its effectives, robustness of the applied technique.

  18. Note: Decoupling design for high frequency piezoelectric ultrasonic transducers with their clamping connections

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F. J., E-mail: wangfujun@tju.edu.cn; Liang, C. M.; Tian, Y. L.; Zhao, X. Y.; Zhang, D. W. [Tianjin Key Laboratory of Equipment Design and Manufacturing Technology, School of Mechanical Engineering, Tianjin University, Tianjin 300072 (China); Zhang, H. J. [Tianjin Key Laboratory of Modern Mechatronics Equipment Technology, School of Mechanical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

    2015-12-15

    This work presents the flexure-mechanism based decoupling design between high frequency piezoelectric ultrasonic transducers and their clamping connections to improve ultrasonic energy transmission efficiency. The ring, prismatic beam, and circular notched hinge based flanges were presented, and the crucial geometric dimensions of the transducers with the flexure decoupling flanges were determined. Finite element analysis (FEA) was carried out to investigate the dynamic characteristics of the transducers. Finally, experiments were conducted to examine and verify the effects of the proposed decoupling flanges. FEA and experimental results show that smaller frequency deviations and larger tip displacement amplitudes have been achieved by using the transducers with the flexure flanges compared with the transducer with a rigid ring-type flange, and thus the ultrasonic transmission efficiency can be improved through the flexure flanges.

  19. Nanoscale-targeted patch-clamp recordings of functional presynaptic ion channels.

    Science.gov (United States)

    Novak, Pavel; Gorelik, Julia; Vivekananda, Umesh; Shevchuk, Andrew I; Ermolyuk, Yaroslav S; Bailey, Russell J; Bushby, Andrew J; Moss, Guy W J; Rusakov, Dmitri A; Klenerman, David; Kullmann, Dimitri M; Volynski, Kirill E; Korchev, Yuri E

    2013-09-18

    Direct electrical access to presynaptic ion channels has hitherto been limited to large specialized terminals such as the calyx of Held or hippocampal mossy fiber bouton. The electrophysiology and ion-channel complement of far more abundant small synaptic terminals (≤ 1 μm) remain poorly understood. Here we report a method based on superresolution scanning ion conductance imaging of small synapses in culture at approximately 100-150 nm 3D resolution, which allows presynaptic patch-clamp recordings in all four configurations (cell-attached, inside-out, outside-out, and whole-cell). Using this technique, we report presynaptic recordings of K(+), Na(+), Cl(-), and Ca(2+) channels. This semiautomated approach allows direct investigation of the distribution and properties of presynaptic ion channels at small central synapses. PMID:24050398

  20. Multi-mode excitation of a clamped–clamped microbeam resonator

    KAUST Repository

    Younis, Mohammad I.

    2015-02-18

    We present modeling and simulation of the nonlinear dynamics of a microresonator subjected to two-source electrostatic excitation. The resonator is composed of a clamped–clamped beam excited by a DC voltage load superimposed to two AC voltage loads of different frequencies. One frequency is tuned close to the first natural frequency of the beam and the other is close to the third (second symmetric) natural frequency. A multi-mode Galerkin procedure is applied to extract a reduced-order model, which forms the basis of the numerical simulations. Time history response, Poincare’ sections, Fast Fourier Transforms FFT, and bifurcation diagrams are used to reveal the dynamics of the system. The results indicate complex nonlinear phenomena, which include quasiperiodic motion, torus bifurcations, and modulated chaotic attractors.

  1. A New Preparation of Pancreatic Ducts for Patch-Clamp Studies

    DEFF Research Database (Denmark)

    Novak, Ivana; Hug, M.J.

    1995-01-01

    -containing solutions. Duct cells were found to have a resting membrane voltage, Vm, of-55 ± 2 mV (n = 63). An increase in the bath K+ concentration (to 19 mmol/l) or an introduction of Ba2+ (3-5 mmol/l) into the bathing solution depolarized Vm by 16 and 22 mV (n = 21; 7), respectively. Secretin (10-9 mol/l) and...... parameters, monitored with the whole-cell patch-clamp method, and those in isolated perfused ducts, monitored with the conventional microelectrodes [Novak I, Greger R: Pflügers Arch 1988;411:58-68, 546-553], are comparable. Similar conclusion can be made about the calcium measurements [Hug M, et al: Pflügers...

  2. A DTC Algorithm for Induction Motor Drives with 3-level Diode-Clamped Inverters

    Directory of Open Access Journals (Sweden)

    M. Cirrincione

    2005-12-01

    Full Text Available This paper presents a novel Direct Torque Control (DTC algorithm for induction motor electrical drives supplied by 3-level diode clamped inverters. It is the natural extension of the classic Switching Table (ST based DTC, modified for a 3-level inverter supply. It presents also a very simple algorithm for the minimization of the capacitor voltage ripple. Results obtained with numerical simulations show that the employment of a 3-level inverter in such a control scheme permits to obtain the same dynamical performances as those obtained with a 2-level inverter with resulting lower torque and flux ripples as well as a lower harmonic content in the stator voltages and currents. Some considerations about the consequent benefits as for EMC of this drive are also presented.

  3. Single stage buck-boost DC-AC neutral point clamped inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Andrew, A.;

    2012-01-01

    windings thus preventing the core from saturation; lowers the voltage stresses and power losses of inverter switches and reduces the sizes of filtering devices and as well as obtains better output performance compared to the original two-level Z-source inverters. A phase disposition pulse width modulation......This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence, it...... has enhanced buck-boost functionality and low output voltage distortions compared to the traditional Z-source inverter; it has continuous input current which reduces the source stress and inverter noise; it also contains two built-in capacitors which can block the DC current in the transformer...

  4. Pulse-Width-Modulation of Neutral-Point-Clamped Sparse Matrix Converter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Gao, F.;

    2007-01-01

    Sparse matrix converter is an alternative "allsemiconductor" energy processor proposed recently for converting an ac source with fixed magnitude and frequency to a variable voltage and frequency supply that can meet the requirements of a particular industry application. In principle, sparse matrix...... input current and output voltage can be achieved with minimized rectification switching loss, rendering the sparse matrix converter as a competitive choice for interfacing the utility grid to (e.g.) defense facilities that require a different frequency supply. As an improvement, sparse matrix converter...... literature. Addressing the afore-described issues, this paper focuses on the operational mode analysis of a three-level sparse matrix converter implemented using a neutral-point-clamped inversion stage, and  the design of a number of PWM and modulation ratio compensation schemes for controlling the converter...

  5. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts......Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage...

  6. Ultra-coherent nanomechanical resonators via soft clamping and dissipation dilution

    CERN Document Server

    Tsaturyan, Yeghishe; Polzik, Eugene S; Schliesser, Albert

    2016-01-01

    The small mass and high coherence of nanomechanical resonators render them the ultimate force probe, with applications ranging from biosensing and magnetic resonance force microscopy, to quantum optomechanics. A notorious challenge in these experiments is thermomechanical noise related to dissipation through internal or external loss channels. Here, we introduce a novel approach to defining nanomechanical modes, which simultaneously provides strong spatial confinement, full isolation from the substrate, and dilution of the resonator material's intrinsic dissipation by five orders of magnitude. It is based on a phononic bandgap structure that localises the mode, without imposing the boundary conditions of a rigid clamp. The reduced curvature in the highly tensioned silicon nitride resonator enables mechanical $Q>10^{8}$ at $ 1 \\,\\mathrm{MHz}$, yielding the highest mechanical $Qf$-products ($>10^{14}\\,\\mathrm{Hz}$) yet reported at room temperature. The corresponding coherence times approach those of optically t...

  7. Simple Switching Strategy for High-Torque Control Performance utilizing Neutral Point Clamped Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    Nor Faezah Alias

    2013-12-01

    Full Text Available Three-level Neutral Point Clamped (NPC inverter allows the configuration of switching devices to operate at high voltage and produce lower current/voltage harmonics. It is known that, DTC of induction machine which employs hysteresis controller has major drawbacks namely larger torque ripple and variable switching frequency. This paper aims to propose a suitable voltage vector selection to provide better torque regulation and lower switching frequency by employing DTC with 3-level NPC multilevel inverter. A simple switching strategy was formulated using 7-level torque hysteresis and 2-level flux hysteresis controllers to give more options in selecting an appropriate voltage vector, inherently, according the motor operation conditions. The improvements offered were verified through simulations.

  8. Influence of pipe wall effects on clamp-on ultrasonic flow measurement

    Energy Technology Data Exchange (ETDEWEB)

    Funck, B.; Mitzkus, A. [Flexim GmbH, Berlin (Germany); Panicke, M.; Specht, O.; Fiedler, O. [Flexim GmbH, Berlin (Germany)]|[Rostock Univ. (Germany). FB Elektrotechnik

    2001-07-01

    Clamp-on ultrasonic flowmeters enable the noninvasive measurement of flow in pipes. The transducers are coupled to the pipe wall and cover a wide range of rated inside diameters when suitably dimensioned. The transit time technique is applicable at sufficiently pure fluids. The time difference of contrapropagating signals is related to the velocity of flow on the path defined by the transducers. The Doppler method utilizes the signals scattered by particles or bubbles. The calibration factor depends on the size and position of the volume determined by the intersection of the transducer beams. The paper reports on effects of the pipe wall on both the transit time technique and the Doppler method of flow measurement. The sound propagation between the transducer is described by acoustic transfer functions. (orig.)

  9. Multifrequency excitation of a clamped–clamped microbeam: Analytical and experimental investigation

    KAUST Repository

    Jaber, Nizar

    2016-03-14

    Using partial electrodes and a multifrequency electrical source, we present a large-bandwidth, large-amplitude clamped–clamped microbeam resonator excited near the higher order modes of vibration. We analytically and experimentally investigate the nonlinear dynamics of the microbeam under a two-source harmonic excitation. The first-frequency source is swept around the first three modes of vibration, whereas the second source frequency remains fixed. New additive and subtractive resonances are demonstrated. We illustrated that by properly tuning the frequency and amplitude of the excitation force, the frequency bandwidth of the resonator is controlled. The microbeam is fabricated using polyimide as a structural layer coated with nickel from the top and chromium and gold layers from the bottom. Using the Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device. A good agreement between the theoretical and experimental data are reported.

  10. Calculation Method for Flight Limit Load of V-band Clamp Separation Shock

    Science.gov (United States)

    Iwasa, Takashi; Shi, Qinzhong

    A simplified calculation method for estimating a flight limit load of the V-band clamp separation shock was established. With this method, the flight limit load is estimated through addition of an appropriate envelope margin to the results acquired with the simplified analysis method proposed in our previous paper. The envelope margin used in the method was calculated based on the reviews on the differences observed between the results of a pyroshock test and the analysis. Using the derived envelope margin, a calculating formula of the flight limit load, which envelopes the actual pyroshock responses with a certain probability, was developed. Based on the formula, flight limit loads for several actual satellites were estimated and compared to the test results. The comparative results showed that the estimated flight limit loads appropriately envelope the test results, which confirmed the effectiveness of the proposed method.

  11. Model Predictive Control of Z-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    2011-01-01

    inductor current, capacitor voltage as well as switching frequency, transient response are all regulated as subjecting to constraints of this control method. The quality of output waveform, stability of impedance-network, level constraint of variable switching frequency as well as robustness of transient......This paper presents Model Predictive Control (MPC) of Z-source Neutral Point Clamped (NPC) inverter. For illustration, current control of Z-source NPC grid-connected inverter is analyzed and simulated. With MPC’s advantage of easily including system constraints, load current, impedance network...... response are obtained at the same time with a formulated Z-source NPC inverter network model. Operation steady state and transient state simulation results of MPC are going to be presented, which shows good reference tracking ability of this method. It provides new control method for Z-source NPC inverter...

  12. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase effic...... efficiency, reduce the product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented.......This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase...

  13. Comparative Analysis and Simulation of Diode Clamped & Cascaded H-Bridge Multilevel Inverter using SPWM Technique

    Directory of Open Access Journals (Sweden)

    Mohit Jain

    2015-01-01

    Full Text Available Multilevel inverters have become more popular over the years in high power medium voltage applications without the use of a transformer and with promise of less disturbance & reduced harmonic distortion. In this paper, two types of multilevel converter in three phase configuration, cascaded H-Bridge multilevel inverter (CMLI and diode clamped multilevel inverter (DCMLI of 5 and 7-level are modelled and compared in the case of feeding of a three phase squirrel cage induction motor. Here, carrier based sinusoidal pulse width modulation (SPWM technique is used as the modulation strategy. These modulation strategy include phase disposition technique (PD, phase opposition disposition technique (POD, and an alternative phase opposition disposition technique (APOD. A detailed study of the modulation technique has been carried out through MATLAB/SIMULINK for both multilevel converters and a comparative evaluation between DCMLI and CMLI using SPWM technique in terms of THD%.

  14. The strain dependence of the transport current characteristics in Bi-2223 silver clamped thick film

    International Nuclear Information System (INIS)

    The dependences of stress on strain, strain on the critical current density, and the relation of Jc(H) at several strains were measured in Bi-2223 silver clamped thick film. The results indicate that the stress-strain curve has two strain transitions which are respectively correspond to the beginning and ending of breaking in Bi1.8Pb0.4Sr2Ca2Cu3Oy thick film. At ΔX/X≤2.5%, the critical current density Jc decreases slowly with ΔX/X increasing. At ΔX/X≥2.5%, Jc decreases rapidly with ΔX/X increasing. As strain increases, the characteristics of Jc(H) decrease rapidly and the weak link junctions emerges obviously. The microstructures show that the decrease of Jc and the variance of characteristics of Jc(H) relate to the breaking of intergrain and grains in the thick film

  15. The fluorescent detection of Paradiplozoon sp. (Monogenea: Diplozoidae attachment clamps' sclerites and integumental proteins : research communication

    Directory of Open Access Journals (Sweden)

    S.J. Milne

    2006-09-01

    Full Text Available In the genus Paradiplozoon, few hard structures are present therefore most of the taxonomic studies have focused on the unique ultrastructure of the sclerites. Alcohol-fixed specimens were transferred to BSA-saline for 5 min. before staining indefinitely with 5 µl WGA-TRX, 5 µl SYTO 9 and 5 µl of Cal co fluor White M2R. Rhodamine, Fluorescein and DAPI bandpass filters on the microscope enabled selective light wavelength illumination of the three flourochromes by a mercury light source. This method provided an easy and rapid methodology to show the internal sclerites of attachment clamps. It is suitable for alcohol preserved specimens and may have additional applications in other helminth organisms.

  16. Palaeoclimate Interpretation at the Locality Velka Causa (Early Miocene, Western Carpathians) based on CLAMP Method

    International Nuclear Information System (INIS)

    Palaeontological locality Velka Causa is situated in the Handlova-Novaky brown-coal basin (Upper Nitra depression) about 3 km north of Velka Causa in an outcrop exposed by a stream flowing through the village of Mala Causa. Studied palaeobotanical material, stored in the Hornonitrianske museum in Prievidza, is fossilized in light-gray clays of Eggenburgian age proved by occurrence of molluscs, foraminifers and ostracods. Sediments were laid down in a sea gulf formed during an Eggenburgian transgression. Plant imprints belong to plants which grew near the sea shore and on the slopes of adjacent mountains. Only dicots were chosen from all fossil leaves occurred in the studied collection. They were sorted into morpho-species and were examined for the presence or absence of each of the 31 morphological characters used after CLAMP categorization. A total of 246 fossil samples were studied. Vegetation used in the dataset for this study indicates subtropical climate.

  17. A Color LED Driver Implemented by the Active Clamp Forward Converter

    Directory of Open Access Journals (Sweden)

    C. H. Chang

    2013-03-01

    Full Text Available Because light emitting diodes (LEDs have the advantages of dc working voltage, high luminescent efficiency, shortignition time, high reliability and pollution free, they have substituted for incandescent bulbs and fluorescent lampsgradually. In order to simplify circuit complexity, an active clamp forward converter with the sequential color display(SCD control is proposed to drive red, green and blue (RGB LED arrays. The proposed converter has zero-voltageswitching (ZVS operations of both the main switch and the auxiliary switch, resulting in high system efficiency. DrivingRGB LED arrays sequentially by one converter can save components and reduce cost significantly. Additionally, thepulse-width modulation (PWM control is applied to achieve a large chromaticity variation. The circuit operations areanalyzed in detail and the circuit parameters are designed based on the practical considerations. Finally, an illustrativeexample is implemented to demonstrate the feasibility and validity of the proposed LED driver.

  18. Room temperature, very sensitive thermometer using a doubly clamped microelectromechanical beam resonator for bolometer applications

    Science.gov (United States)

    Zhang, Y.; Watanabe, Y.; Hosono, S.; Nagai, N.; Hirakawa, K.

    2016-04-01

    We propose a room temperature, all electrical driving and detecting, very sensitive thermometer structure using a microelectromechanical (MEMS) resonator for bolometer applications. We have fabricated a GaAs doubly clamped MEMS beam resonator whose oscillation can be excited and detected by the piezoelectric effect. When a heating power is applied to a NiCr film deposited on the MEMS beam surface, internal thermal stress is generated in the beam, leading to a reduction in the resonance frequency. The present device detects the shift in the resonance frequency caused by heating and works as a very sensitive thermometer. When the resonator was driven by a voltage slightly below the threshold for the nonlinear, hysteretic oscillation, the thermometer showed a voltage responsivity of about 3300 V/W, while keeping a low noise spectral density of about 60 nV/Hz1/2, demonstrating a noise equivalent power of bolometers for room-temperature operation.

  19. Characterization of a patch-clamp microchannel array towards neuronal networks analysis

    DEFF Research Database (Denmark)

    Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.;

    2010-01-01

    simultaneous patch clamping of cultured cells or neurons in the same network. A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work as a...... theory, but the capacitance is still too high for high resolution recording. The system was tested on HeLa cells: successful cell trapping with a sealing of 40 M Omega was recorded. Modification of the Si/SiO2 chip is needed in order to achieve a better sealing and long-term cell culturing in the PC mu...

  20. Five-Level Z-Source Neutral Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede;

    2007-01-01

    This paper proposes a five-level Z-source neutralpoint- clamped (NPC) inverter with two Z-source networks functioning as intermediate energy storages coupled between dc sources and NPC inverter circuitry. Analyzing the operational principles of Z-source network with partial dclink shoot......-through scheme reveals the hidden theories in the five-level Z-source NPC inverter unlike the operational principle appeared in the general two-level Z-source inverter, so that the five-level Z-source NPC inverter can be designed with the modulation of carrier-based phase disposition (PD) or alternative phase...... opposite disposition (APOD) technique. To verify the theoretical findings and practical issues, a scaled down laboratory prototype was constructed and tested with a 1.3 kw induction motor load....

  1. Gel chromatography of immunoextracted plasma calcitonin in response to the calcium clamp in healthy males

    International Nuclear Information System (INIS)

    A radioimmunoassay (RIA) was developed for immunoreactive calcitonin (iCT) in human plasma. Antibodies against synthetic human calcitonin (hCT) coupled to bovine serum albumin (BSA) were raised in rabbits and were directed against the carboxy terminal part of CT. The detection limit of the assay was 8 pg/ml. In 7 males the iCT response to a calcium-clamp was studied. Blood was collected at 0,30 and 60 min after the start of the calcium infusion. iCT was measured directly in plasma and in extracts obtained after purification of plasma iCT by means of immobilized CT antiboides. There was a good correlation between iCT in plasma samples and extracts, r = 0.993, n = 14 (P< 0.001). Dilution curves of extracts and plasma were parallel with the hCT standard curves. Gel chromatography of the extracts on Sephadex G-50 and G-75 disclosed heterogeneity of iCT in normal plasma during basal conditions as well as during calcium stimulation. Thirty min after the start of the calcium clamp all molecular forms, most likely constituting monomeric and dimeric CT and larger forms, were increased, while after 60 min iCT seemed to constitute predominantly forms larger than monomeric TCY. Basal levels of unextracted iCT in healthy males (n = 44, 37 +/- 10 years) were 15 +/- 9 pg-equivalents/ml (mean +/- SD), which was higher than in females (n = 40, 32 +/- 9 years) 11 +/- 4 pg-equivalents/ml (P < 0.05). (author)

  2. Management of open olecranon fractures using clamp-cum-compressor device

    Directory of Open Access Journals (Sweden)

    Kundu Zile

    2009-01-01

    Full Text Available Background: Open fractures of olecranon are not a rare occurrence in patients with road traffic accidents particularly motor bike riders who don′t use elbow guards. Definitive treatment has to be delayed in many till the wound heals. The present study was conducted to evaluate the results of open fractures of olecranon using clamp-cum-compressor device. Materials and Methods: Seventeen patients between the ages of 20 and 45 years of open olecranon fractures reported 5-20 days after injury were treated using an indigenous clamp-cum-compressor. All fractures were Mayo type II-A, i.e., displaced, stable and noncomminuted. Four patients had Gustilo-Anderson grade I and 13 had Gustilo-Anderson grade II open fractures. The patients with transverse or short oblique fractures were included in the study. The apparatus was applied under regional anesthesia after thorough washing and debridement of wounds with few loose sutures applied wherever needed. The wounds healed within 2-4 weeks and fractures united within 8-10 weeks. The elbow was mobilized with apparatus still in place. The results were evaluated by MayoElbow performance score. Results: We achieved excellent results in twelve patients, good in four and poor in one patient, who reported late, hooks of the apparatus were cut through the proximal fragment, leading to union of fracture in elongation and restricted elbow movements. Conclusion: The apparatus was found to be quite useful in transverse and short oblique fractures with contamination or infection, where internal fixation has to be delayed or avoided.

  3. Dynamic response of a clamped/free hollow circular cylinder under travelling torsional impact loads

    International Nuclear Information System (INIS)

    Impact-induced vibrations in the casing of a gas centriguge due to a sudden failure of the spinning rotor (crash) can cause structural disintegrity of the casing. In order to study the influence of the rotor failure bahaviour and the impact load histories on the dynamic response of the casing, a simple crash model is proposed in this paper to analyse the transient torsional response due to tangential components of the impact loads. The casing is modeled as a linear-elastic hollow circular cylinder, clamped at the lower end and free at the upper end. The rotor is thought to breakup in identical sections in a sequence determined by its fracture behaviour. Each section is assumed to cause an axi-symmetric load distribution at the inner surface of the casing. Therefore the problem is essentially reduced to the analysis of a clamped/free cylinder under travelling torsional impact loads. The problem is solved by representing the impact loads as local pulses acting over the length of the sections. A perturbation method is used to show that the general two-dimensional theory of axi-symmetric torsional wave propagation in circular cylinders, for the problem under consideration, may be approximated by the elementary one-dimensional theory. Solutions are obtained according to the usual modal expansion approach. Measurements of transient torsional responses are shown to be in good agreement with the calculated responses by choosing a suitable shape of the pulses. The effects of travelling velocity and pulse shape are investigated. Finally the transfer of kinetic energy in the rotor to vibrational energy of torsion in the casing is studied. (orig.)

  4. MATLAB-based automated patch-clamp system for awake behaving mice.

    Science.gov (United States)

    Desai, Niraj S; Siegel, Jennifer J; Taylor, William; Chitwood, Raymond A; Johnston, Daniel

    2015-08-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585-587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process that revolves around analysis of a single signal (electrode impedance) and movement along a single axis. Here, we introduce an automated system for blind patch-clamp recordings from awake, head-fixed mice running on a wheel. In its design, we were guided by 3 requirements: easy-to-use and easy-to-modify software; seamless integration of behavioral equipment; and efficient use of time. The resulting system employs equipment that is standard for patch recording rigs, moderately priced, or simple to make. It is written entirely in MATLAB, a programming environment that has an enormous user base in the neuroscience community and many available resources for analysis and instrument control. Using this system, we obtained 19 whole cell patch recordings from neurons in the prefrontal cortex of awake mice, aged 8-9 wk. Successful recordings had series resistances that averaged 52 ± 4 MΩ and required 5.7 ± 0.6 attempts to obtain. These numbers are comparable with those of experienced electrophysiologists working manually, and this system, written in a simple and familiar language, will be useful to many cellular electrophysiologists who wish to study awake behaving mice. PMID:26084901

  5. Progress and Outlook on Technologies for Processing Inferior Crude Oil in China

    Institute of Scientific and Technical Information of China (English)

    Yuan Qingtang

    2008-01-01

    The recent growth of the global petroleum refining industry and the main technologies and measures for China to process inferior crude oil were introduced. The main technologies and measures include the control over equipment corrosion induced by sour and acidic crude, in particular the corrosion of atmospheric and vacuum distillation units, the development of technology for processing inferior residue,and the development of desulfurization technology and sulfur recovery technology in the course of processing of petroleum products. In order to meet the needs for national economic development, China's refining enterprises will uninterruptedly develop and prefect technologies for processing inferior crude,enhance the process and equipment management, sum up the experience for better processing of inferior crude, so as to provide high-quality oil products and petrochemical feedstocks to public with better economic return.

  6. Facilitated lexical ambiguity processing by transcranial direct current stimulation over the left inferior frontal cortex.

    Science.gov (United States)

    Ihara, Aya S; Mimura, Takanori; Soshi, Takahiro; Yorifuji, Shiro; Hirata, Masayuki; Goto, Tetsu; Yoshinime, Toshiki; Umehara, Hiroaki; Fujimaki, Norio

    2015-01-01

    Previous studies suggest that the left inferior frontal cortex is involved in the resolution of lexical ambiguities for language comprehension. In this study, we hypothesized that processing of lexical ambiguities is improved when the excitability of the left inferior frontal cortex is enhanced. To test the hypothesis, we conducted an experiment with transcranial direct current stimulation (tDCS). We investigated the effect of anodal tDCS over the left inferior frontal cortex on behavioral indexes for semantic judgment on lexically ambiguous and unambiguous words within a context. Supporting the hypothesis, the RT was shorter in the anodal tDCS session than in the sham session for ambiguous words. The results suggest that controlled semantic retrieval and contextual selection were facilitated by anodal tDCS over the left inferior frontal cortex. PMID:25208744

  7. Active management of the third stage of labour without controlled cord traction: a randomized non-inferiority controlled trial

    Directory of Open Access Journals (Sweden)

    Derman Richard

    2009-01-01

    Full Text Available Abstract Background The third stage of labour refers to the period between birth of the baby and complete expulsion of the placenta. Some degree of blood loss occurs after the birth of the baby due to separation of the placenta. This period is a risky period because uterus may not contract well after birth and heavy blood loss can endanger the life of the mother. Active management of the third stage of labour (AMTSL reduces the occurrence of severe postpartum haemorrhage by approximately 60–70%. Active management consists of several interventions packaged together and the relative contribution of each of the components is unknown. Controlled cord traction is one of those components that require training in manual skill for it to be performed appropriately. If it is possible to dispense with controlled cord traction without losing efficacy it would have major implications for effective management of the third stage of labour at peripheral levels of health care. Objective The primary objective is to determine whether the simplified package of oxytocin 10 IU IM/IV is not less effective than the full AMTSL package. Methods A hospital-based, multicentre, individually randomized controlled trial is proposed. The hypothesis tested will be a non-inferiority hypothesis. The aim will be to determine whether the simplified package without CCT, with the advantage of not requiring training to acquire the manual skill to perform this task, is not less effective than the full AMTSL package with regard to reducing blood loss in the third stage of labour. The simplified package will include uterotonic (oxytocin 10 IU IM injection after delivery of the baby and cord clamping and cutting at approximately 3 minutes after birth. The full package will include the uterotonic injection (oxytocin 10 IU IM, controlled cord traction following observation of uterine contraction and cord clamping and cutting at approximately 3 minutes after birth. The primary outcome

  8. Prenatal diagnosis of isolated interrupted inferior vena cava with azygos continuation to superior vena cava

    Directory of Open Access Journals (Sweden)

    Do Thi Cam Giang

    2014-01-01

    Full Text Available Absence of inferior vena cava is an uncommon congenital abnormality. It is usually associated with other structural anomalies, typically left isomerism. We report a case of interrupted inferior vena cava with azygos continuation diagnosed as an isolated finding during routine prenatal ultrasound scan, confirmed by post-natal echocardiography. Detailed ultrasound examination of the fetal anatomy failed to demonstrate other anomalies. The neonatal course of this fetus was uneventful.

  9. A novel technique to remove inferior vena cava filters using a homemade snare device.

    Science.gov (United States)

    Singh, Kuldeep; Zia, Saqib; Khan, Muhammad Asad; Marco, Sean; Hill, David

    2014-01-01

    The need to retrieve inferior vena cava filters is quite evident due to the long-term complications. We present a novel technique to remove inferior vena cava filters using a homemade snare created using a looped a 0.014-inch semistiff wire. Employing this technique, 18 consecutive retrievable filters were removed. All filters were easily snared on the very first attempt, and no complications occurred. Our novel technique to retrieve filters is efficient, safe, and cost-effective. PMID:26992977

  10. Living donor liver transplantation in the absence of inferior vena cava: a case report.

    Science.gov (United States)

    Hatipoglu, S; Olmez, A; Ozgor, D; Kayaalp, C; Yilmaz, S

    2012-01-01

    Because of difficulties in the supply of cadaveric organs, of living donor liver transplantations are performed in increasing numbers. Congenital hepatic fibrosis associated with fibrosis and atrophy of the inferior vena cava were present in a potential recipient of living donor liver transplantation. This case report documented living donor liver transplantation as a treatment modality for a patient with absence of the inferior vena cava due to chronic liver failure. PMID:22841266

  11. Anatomy of the ostia venae hepaticae and the retrohepatic segment of the inferior vena cava.

    OpenAIRE

    Camargo, A M; Teixeira, G G; Ortale, J R

    1996-01-01

    In 30 normal adult livers the retrohepatic segment of inferior vena cava had a length of 6.7 cm and was totally encircled by liver substance in 30% of cases. Altogether 442 ostia venae hepaticae were found, averaging 14.7 per liver and classified as large, medium, small and minimum. The localisation of the openings was studied according to the division of the wall of the retrohepatic segment of the inferior vena cava into 16 areas.

  12. Anatomy of the ostia venae hepaticae and the retrohepatic segment of the inferior vena cava.

    Science.gov (United States)

    Camargo, A M; Teixeira, G G; Ortale, J R

    1996-02-01

    In 30 normal adult livers the retrohepatic segment of inferior vena cava had a length of 6.7 cm and was totally encircled by liver substance in 30% of cases. Altogether 442 ostia venae hepaticae were found, averaging 14.7 per liver and classified as large, medium, small and minimum. The localisation of the openings was studied according to the division of the wall of the retrohepatic segment of the inferior vena cava into 16 areas. PMID:8655416

  13. Heterotopic ossification following surgical treatment of avulsion fracture of the anterior inferior iliac spine

    OpenAIRE

    Gojković Zoran; Harhaji Vladimir; Milankov Miroslav Ž.; Drapšin Miodrag

    2011-01-01

    Avulsion fractures of the anterior inferior iliac spine are rare injuries of the pelvic ring and occur during sports activities. Hereby is presented a case of a 22-year-old professional football player who was diagnosed to have an avulsion fracture of the anterior inferior iliac spine on the right side four months after the initial injury and he was treated surgically with the excision of the avulsed fragment. The football player recovered completely and returned to his usual sports act...

  14. Huge Trombus including Left Renal Vein, Ovarian Vein, and Inferior Vena Cava Mimicking Renal Colic

    OpenAIRE

    Sakir Ongun; Sermin Coban; Abdullah Katgi; Funda Obuz; Aykut Kefi

    2014-01-01

    A 31-year-old female presented with acute left flank pain; she had a C/S at the postpartum day 24. Ureteral stone was suspected but ultrasound examination was normal. Then Doppler ultrasound revealed a trombus in left renal vein and inferior vena cava. Contrast enhanced MDCT scan showed swelled and nonfunctional left kidney, a trombus including distal part of left ovarian vein, left renal vein, and inferior vena cava. We started anticoagulation treatment. Further examination revealed diagnosi...

  15. Significance of initial ST segment changes for thrombolytic treatment in first inferior myocardial infarction.

    OpenAIRE

    Schröder, K; Wegscheider, K; Neuhaus, K. L.; Tebbe, U; Schröder, R.

    1997-01-01

    OBJECTIVE: To evaluate the benefit to risk ratio of thrombolytic treatment in patients with small inferior acute myocardial infarction (AMI). Controlled studies relating the benefit from thrombolysis with initial electrocardiographic features are scarce and of limited sample size. DESIGN: Retrospective study of 728 patients with a first inferior AMI of six hours' duration from the Intravenous Streptokinase in Acute Myocardial Infarction (ISAM) study comparing streptokinase with placebo strati...

  16. Hypoactivation in right inferior frontal cortex is specifically associated with motor response inhibition in adult ADHD

    OpenAIRE

    Morein-Zamir, Sharon; Dodds, Chris; van Hartevelt, Tim J.; Schwarzkopf, Wolfgang; Sahakian, Barbara; Müller, Ulrich; Robbins, Trevor

    2014-01-01

    Adult ADHD has been linked to impaired motor response inhibition and reduced associated activation in the right inferior frontal cortex (IFC). However, it is unclear whether abnormal inferior frontal activation in adult ADHD is specifically related to a response inhibition deficit or reflects a more general deficit in attentional processing. Using functional magnetic resonance imaging, we tested a group of 19 ADHD patients with no comorbidities and a group of 19 healthy control volunteers on ...

  17. Rezeptorarchitektonische Kartierung der Broca-Region und angrenzender Areale im posterioren inferior-frontalen Kortex

    OpenAIRE

    Falk, Marianne

    2008-01-01

    In order to enhance our functional and anatomical understanding of Broca’s region and neighbouring areas in the posterior inferior-frontal cortex, a multimodal parcellation was conducted to create the foundation for a reliable localisation of functional activations. The present doctoral thesis gives the first complete, comprehensive receptor architectonic description of the posterior inferior-frontal cortex. The laminar and regional distribution patterns of the neurotransmitters noradrenalin,...

  18. Inferior Alveolar Nerve Injuries Following Implant Placement - Importance of Early Diagnosis and Treatment: a Systematic Review

    OpenAIRE

    Ilana Shavit; Gintaras Juodzbalys

    2014-01-01

    ABSTRACT Objectives The purpose of this article is to systematically review diagnostic procedures and risk factors associated with inferior alveolar nerve injury following implant placement, to identify the time interval between inferior alveolar nerve injury and its diagnosis after surgical dental implant placement and compare between outcomes of early and delayed diagnosis and treatment given based on case series recorded throughout a period of 10 years. Material and Methods We performed li...

  19. Massive hemothorax due to inferior phrenic artery injury after blunt trauma

    OpenAIRE

    Aoki, Makoto; Shibuya, Kei; Kaneko, Minoru; Koizumi, Ayana; Murata, Masato; Nakajima, Jun; Hagiwara, Shuichi; Kanbe, Masahiko; Koyama, Yoshinori; Tsushima, Yoshito; Oshima, Kiyohiro

    2015-01-01

    Injury to the inferior phrenic artery after blunt trauma is an extremely rare event, and it may occur under unanticipated conditions. This case report describes an injury to the left inferior phrenic artery caused by blunt trauma, which was complicated by massive hemothorax, and treated with transcatheter arterial embolization (TAE). An 81 year-old female hit by a car while walking at the traffic intersection was transferred to the emergency department, computed tomography scanning revealed a...

  20. Prevalence, morphological and electrophysiological characteristics of confluent inferior pulmonary veins in patients with atrial fibrillation

    International Nuclear Information System (INIS)

    Although the common trunk of left pulmonary veins (PVs) has been reported as a relatively popular anatomical variation of PVs, little is known about the coalescence of contralateral PVs. The present study was conducted to reveal the prevalence and electrophysiologic characteristics of the confluent inferior common PVs. Anatomical variation in the PV drainage to the left atrium (LA) was assessed using the multidetector computed tomography scan in 326 patients with atrial fibrillation (AF) who underwent the PV isolation procedure. Coalescence of inferior PVs was observed in 5 cases (1.5%). Both inferior PVs conjoined prior to the junction with the LA in 3 cases, while they coalesced at the LA junction in the other 2 cases. The arrhythmogenic activities of the confluent inferior PVs were generally low in all cases without any ectopic firings triggering the observed AF. All inferior PVs, as well as the superior PVs, were successfully isolated either en bloc at the common trunk or individually at the orifice of each PV. Confluent inferior PVs were present in 1.5% of cases in patients with AF who underwent the PV isolation procedure. Preoperative recognition of this venous anomaly by 3-dimensional imaging is important for smooth and safe ablation. (author)

  1. New Modulation Strategy to Balance the Neutral-Point Voltage for Three-Level Neutral-Clamped Inverter Systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, June-Seok; Lee, Kyo-Beum

    2014-01-01

    This paper proposes a new modulation strategy that balances the neutral-point voltage for three-level neutral-clamped inverter systems. The proposed modulation replaces the P-type or N-type small switching states with other switching states that do not affect the neutral-point voltage. The zero and...

  2. Modulation Methods for Three-level Neutral-Point-Clamped Inverter Achieving Stress Redistribution under Moderate Modulation Index

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2016-01-01

    This letter investigates the loss and thermal behaviors of a three-level neutral-point-clamped (3L-NPC) inverter undergoing moderate modulation index, which is typically presented during minor voltage sags of the power grid or speed changes of the electric machines. A series of new space vector m...

  3. Characterization of heterologously expressed transporter genes by patch- and voltage-clamp methods: Application to cyclic nucleotide-dependent responses

    KAUST Repository

    Lemtiri-Chlieh, Fouad

    2013-09-03

    The application of patch- and voltage-clamp methods to study ion transport can be limited by many hurdles: the size of the cells to be patched and/or stabbed, the subcellular localization of the molecule of interest, and its density of expression that could be too low even in their own native environment. Functional expression of genes using recombinant DNA technology not only overcomes those hurdles but also affords additional and elegant investigations such as single-point mutation studies and subunit associations/regulations. In this chapter, we give a step-by-step description of two electrophysiological methods, patch clamp and two-electrode voltage clamp (TEVC), that are routinely used in combination with heterologous gene expression to assist researchers interested in the identification and characterization of ion transporters. We describe how to (1) obtain and maintain the cells suitable for the use with each of the above-mentioned methods (i.e., HEK-293 cells and yeast spheroplasts to use with the patch-clamp methodology and Xenopus laevis oocytes with TEVC), (2) transfect/inject them with the gene of interest, and (3) record ion transport activities. © Springer Science+Business Media New York 2013.

  4. Measurement of the cell membrane capacitance and conductance of colonic crypt cells of the rat using the patch clamp technique

    OpenAIRE

    Schill, C.

    2005-01-01

    Using the patch clamp technique the membrane capacitance and membrane conductance of colonic crypt cells of the rat was measured. The influence of the intracellular agonists Ca++, cAMP and of osmotic changes on the membrane capacitance and conductance was studied.

  5. Asystole to cross-clamp period predicts development of biliary complications in liver transplantation using donation after cardiac death donors.

    Science.gov (United States)

    Taner, C Burcin; Bulatao, Ilynn G; Perry, Dana K; Sibulesky, Lena; Willingham, Darrin L; Kramer, David J; Nguyen, Justin H

    2012-08-01

    This study sought to determine the procurement factors that lead to development of intrahepatic bile duct strictures (ITBS) and overall biliary complications in recipients of donation after cardiac death (DCD) liver grafts. Detailed information for different time points during procurement (withdrawal of support; SBP mandatory wait period; asystole; incision; aortic cross clamp) and their association with the development of ITBS and overall biliary complications were examined using logistic regression. Two hundred and fifteen liver transplants using DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida. Of all the time periods during procurement, only asystole-cross clamp period was significantly different between patients with ITBS versus no ITBS (P = 0.048) and between the patients who had overall biliary complications versus no biliary complications (P = 0.047). On multivariate analysis, only asystole-cross clamp period was significant predictor for development of ITBS (P = 0.015) and development of overall biliary complications (P = 0.029). Hemodynamic changes in the agonal period did not emerge as risk factors. The results of the study raise the possibility of utilizing asystole-cross-clamp period in place of or in conjunction with donor warm ischemia time in determining viability or quality of liver grafts. PMID:22703372

  6. The application of the Escherichia coli giant spheroplast for drug screening with automated planar patch clamp system

    Directory of Open Access Journals (Sweden)

    Kyoko Kikuchi

    2015-09-01

    Full Text Available Kv2.1, the voltage-gated ion channel, is ubiquitously expressed in variety of tissues and dysfunction of this ion channel is responsible for multiple diseases. Electrophysiological properties of ion channels are so far characterized with eukaryotic cells using the manual patch clamp which requires skilful operators and expensive equipments. In this research, we created a simple and sensitive drug screen method using bacterial giant spheroplasts and the automated patch clamp which does not require special skills. We expressed a eukaryotic voltage-gated ion channel Kv2.1 in Escherichia coli using prokaryotic codon, and prepared giant spheroplasts large enough for the patch clamp. Human Kv2.1 currents were successfully recorded from giant spheroplasts with the automated system, and Kv2.1-expressed E. coli spheroplasts could steadily reacted to the dose–response assay with TEA and 4-AP. Collectively, our results indicate for the first time that the bacterial giant spheroplast can be applied for practical pharmaceutical assay using the automated patch clamp.

  7. Structure of p15PAF-PCNA complex and implications for clamp sliding during DNA replication and repair

    DEFF Research Database (Denmark)

    De Biasio, Alfredo; de Opakua, Alain Ibáñez; Mortuza, Gulnahar B;

    2015-01-01

    The intrinsically disordered protein p15(PAF) regulates DNA replication and repair by binding to the proliferating cell nuclear antigen (PCNA) sliding clamp. We present the structure of the human p15(PAF)-PCNA complex. Crystallography and NMR show the central PCNA-interacting protein motif (PIP...

  8. Late umbilical cord-clamping as an intervention for reducing iron deficiency anaemia in term infants in developing and industrialised countries : a systematic review

    NARCIS (Netherlands)

    van Rheenen, Patrick; Brabin, Bernard J

    2004-01-01

    This review evaluates the potential of delayed cord-clamping for improving iron status and reducing anaemia in term infants and for increasing the risk of polycythaemia and hyperbilirubinaemia. We applied a strict search protocol to identify controlled trials of early vs late cord-clamping. Four tri

  9. Issues on the selection of non-inferiority margin in clinical trials

    Institute of Scientific and Technical Information of China (English)

    HOU Yan; WU Xiao-yan; LI Kang

    2009-01-01

    Objective The determination of non-inferiority margin is an important and confusing issue which directly influences the acceptability of a new medication. We reviewed the published literature, International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) Guidelines and Committee for Proprietary Medicinal Products (CPMP) papers on the selection of non-inferiority margin and the corresponding statistical tests in clinical trials, in order to provide practical recommendations and suggestions for establishing reference criteria for the non-inferiority margin in China.Data sources The literature on the selection of a non-inferiority margin and statistical tests was mainly extracted from relevant English articles on non-inferior clinical trials published from 1990 to 2007. The starting point (1990) was chosen due to lack of such papers published prior to 1990. This literature was searched via PubMed, Medline and Chinese Knowledge Information (CNKI). ICH guidelines and CPMP papers were downloaded from their official websites. The keywords "clinical trial", "non-inferiority" and "non-inferiority margin" were used.Study selection Forty-three original articles and critical reviews, ICH E10 guideline and CPMP papers were selected.Results The non-inferiority testing with treatment difference and ratio are commonly used, where the non-inferiority margin is determined with and without historical data. Traditionally, this margin is treated as a fixed value, while developed methods take the variation into account in the determination of this margin, on which the test depends is more convincing. The mixed margin consisting of a margin based on treatment difference and a margin based on treatment ratio can exactly control the type Ⅰ error at the desirable level and obtain a better power. In this review, we also provide some recommendations and suggestions for the selection of the non-inferiority margin in the western

  10. Study of 99Tcm-annexin V distribution in inferior vena cava thrombus models of rabbits

    International Nuclear Information System (INIS)

    To study 99Tcm-Annexin V distribution in inferior vena cava thrombus models of rabbits and uptake of 99Tcm-Annexin V in fresh and old venous thrombus. Rabbits (n=15) were randomly grouped into 3 groups (the fresh thrombus group, old thrombus group, and control group). The rabbits of two thrombus groups developed inferior vena cava thrombus models by operations. The control group received sham operation. The fresh thrombus group and control group rabbits were injected 99Tcm-Annexin V after operating 1 d; the old thrombus group 14 d. After 1 h all rabbits were killed by injecting overdose pentobarbital sodium. The thrombus (or the inferior vena cava about 3 cm below inferior pole of right kidney level in the control group rabbits), blood, thrombus area inferior vena cava, head lateral inferior vena cava (except the control group), thigh muscle, stomach, myocardium, pulmonary, liver, kidney, spleen, bone and small intestine were obtained from all group rabbits. The ex tissue and blood were weighed and measured by a Well-type detector. The percentage of the injected dose per gram of ex tissue (or blood) was calculated by the above data. The thrombus to blood, thrombus area inferior vena cava, head lateral inferior vena cava and thigh muscle ratios were calculated by percentage of the injected dose per gram of ex tissue (or blood). The test was used to compare the fresh thrombus group and old thrombus group by SPSS 17.0. The percentage of' the injected dose per gram of thrombi (0.01894± 0.002 16% ID/g) in the fresh thrombus group was higher than the old thrombus group (0.00473±0.001 28% ID/g), P<0.05. The thrombus to blood, thrombus area inferior vena cava, head lateral inferior vena cava and muscle ratios (3.42±1.06, 26.32±13.60, 31.23 ±16.00, 111.62±52.23) in the fresh thrombus group were higher than the old thrombus group (0.98±0.09, 5.12±2.01, 6.25±2.38, 21.82±5.93), P<0.05 for all. All the thrombi of the fresh thrombus group were confirmed fresh

  11. Isolated PWM DC-AC SICAM with an active capacitive voltage clamp[Pulse Density Modulated; Pulse Width Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2004-03-15

    In this report an isolated PWM DC-AC SICAM with an active capacitive voltage clamp is presented. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitors and possibly with an EMC filter on the mains entrance. Isolation from the AC mains is achieved using a high frequency (HF) transformer, whose voltages are not audio-modulated. The latter simplifies the design and is expected to have many advantages over the approach where the transformer voltages are modulated in regards to the audio signal reference. Input stage is built as a DC-AC inverter (push-pull, half-bridge or a full-bridge) and operated with 50% duty cycle, with all the challenges to avoid transformer saturation and obtain symmetrical operation. On the secondary side the output section is implemented as rectifier+inverter AC-AC stage, i.e. a true bidirectional bridge, which operation is aimed towards amplification of the audio signal. In order to solve the problem with the commutation of the load current, a dead time between the incoming and outgoing bidirectional switch is implemented, while a capacitive voltage clamp is used to keep the induced overvoltage to reasonable levels. The energy stored in the clamping capacitor is not wasted as in the dissipative clamps, but is rather transferred back to the primary side for further processing using an auxiliary isolated single-switch converter, i.e. an active clamping technique is used. (au)

  12. The position of the mandibular canal and histologic feature of the inferior alveolar nerve.

    Science.gov (United States)

    Kilic, C; Kamburoğlu, K; Ozen, T; Balcioglu, H A; Kurt, B; Kutoglu, T; Ozan, H

    2010-01-01

    The inferior alveolar nerve is the one of the large branches of the mandibular division of the trigeminal nerve. It is vulnerable during surgical procedures of the mandible. Despite its importance, no anatomical and histological examination has been conducted to provide a detailed cross-sectional morphology of the mandibular canal according to dental status. Therefore, the present study aimed to identify the position of the mandibular canal through direct measurement and to determine the branches of the inferior alveolar nerve through histologic examination. The area between the anterior margin of the third molar and the anterior margin of the second premolar of dentulous, partially dentulous, and edentulous hemimandible specimens (n = 49) from 26 human cadavers was serially sectioned into seven segments, and specific distances were measured using digital calipers. Following this, 5-microm cross-sections were prepared along the mandibular canal and mental foramen, and examined by fluorescence microscopy. The mandibular canal was located at a mean distance of 10.52 mm above the inferior margin of the mandible. The mean maximum diameters of the mandibular canal, inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein were 2.52, 1.84, 0.42, and 0.58 mm, respectively. This study found that the inferior alveolar nerve often gives rise to several branches at each level (range 0-3). To minimize the risk of injury, knowledge of the small branches of the nerve and of the detailed findings regarding the position of the mandibular canal reported here should be considered when planning mandibular surgery, especially during implant placement. PMID:19918867

  13. Preliminary evaluation of the deep inferior epigastric artery perforator with CT angiography

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical value of multislice-CT angiography (MSCTA) in planning for the patients undergoing deep inferior epigastric artery perforator (DIEAP) flap operations. Methods: Eighteen patients were performed with a 16-slice CT scanner to evaluate the deep inferior epigastric artery perforator prior to DIEAP flap operations. Axial, multiplanar reconstruction (MPR), maximum intensity projection (MIP) and volume rendered( VR) images were analysed and the origins, calibers, courses and anatomic relationships of the deep inferior epigastric artery perforator were evaluated. The anastomosis between the superficial inferior epigastric artery and the main perforator was observed as well. The images were classified into three grades based on the vessels' appearance. A + indicated the vessel appeared clear, continuous and thick. A - indicated the vessel appeared foggy, discontinuous and thin or the vessel partly showed. B indicated no related vessel can be seen. Other 18 patients undergoing conventional abdomen-pelvis CT scans for other reasons were used for control group t o compare their CT findings of the deep inferior epigastric artery perforator. Results: MSCTA well showed the course of the deep inferior epigastric artery (DIEA). Of the 18 cases, 17 cases appeared as A +, another one A -. It precisely displayed the origins, subcutaneous and intramuscular courses, relations of the main perforators on all cases of showing A +. The exact points where the chosen perforator vessels emerged from the rectus abdominis muscle fascia were located precisely. The superficial inferior epigastric arteries were mostly displayed and the connection between the arteries and the largest-caliber perforator from the deep system could also be shown clearly. Strict concordance with operative findings was found in CTA. Conclusion: MSCTA can precisely locate the chosen perforator vessels emerging from the rectus abdominis muscle fascia and it may be a feasible, fast, safe

  14. Illuminating Myocyte-Fibroblast Homotypic and Heterotypic Gap Junction Dynamics Using Dynamic Clamp.

    Science.gov (United States)

    Brown, Tashalee R; Krogh-Madsen, Trine; Christini, David J

    2016-08-23

    Fibroblasts play a significant role in the development of electrical and mechanical dysfunction of the heart; however, the underlying mechanisms are only partially understood. One widely studied mechanism suggests that fibroblasts produce excess extracellular matrix, resulting in collagenous septa that slow propagation, cause zig-zag conduction paths, and decouple cardiomyocytes, resulting in a substrate for cardiac arrhythmia. An emerging mechanism suggests that fibroblasts promote arrhythmogenesis through direct electrical interactions with cardiomyocytes via gap junction (GJ) channels. In the heart, three major connexin (Cx) isoforms, Cx40, Cx43, and Cx45, form GJ channels in cell-type-specific combinations. Because each Cx is characterized by a unique time- and transjunctional voltage-dependent profile, we investigated whether the electrophysiological contributions of fibroblasts would vary with the specific composition of the myocyte-fibroblast (M-F) GJ channel. Due to the challenges of systematically modifying Cxs in vitro, we coupled native cardiomyocytes with in silico fibroblast and GJ channel electrophysiology models using the dynamic-clamp technique. We found that there is a reduction in the early peak of the junctional current during the upstroke of the action potential (AP) due to GJ channel gating. However, effects on the cardiomyocyte AP morphology were similar regardless of the specific type of GJ channel (homotypic Cx43 and Cx45, and heterotypic Cx43/Cx45 and Cx45/Cx43). To illuminate effects at the tissue level, we performed multiscale simulations of M-F coupling. First, we developed a cell-specific model of our dynamic-clamp experiments and investigated changes in the underlying membrane currents during M-F coupling. Second, we performed two-dimensional tissue sheet simulations of cardiac fibrosis and incorporated GJ channels in a cell type-specific manner. We determined that although GJ channel gating reduces junctional current, it does not

  15. Dual joint space arthrography in temporomandibular joint disorders: Comparison with single inferior joint space arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyung Sik; Chang, Duk Soo; Lee, Kyung Soo; Kim, Woo Sun; Sung, Jung Ho; Jun, Young Hwan [Capital Armed Forces General Hospital, Seoul (Korea, Republic of)

    1989-02-15

    The temporomandibular joint(TMJ) is really a complex of two synovial space separated by fibrocartilaginous disc. Single inferior joint space arthrography is commonly performed for evaluation of TMJ disorders, which is known to be superior in demonstrating joint dynamics. But it reveals only the inferior surface of the disc. Therefore, dual space arthrography is superior to demonstrate the soft tissue anatomic feature of the joint such as disc position and shape. Authors performed 83 TMJ arthrograms in TMJ problems. Initially, the inferior joint space was done and then the superior space was sequentially contrasted. The follow results were noted: 1. In all cases, dual space arthrography revealed accurate disc shape and positions. 2. Concordant findings between the two techniques: 68 cases (82%). Discordance between the two techniques: 15 cases (18%) 3. Possible causes of discordance between inferior and dual space arthrography. a) Normal varians of anterior recess: 3 cases b) Posterior disc displacement: 4 cases c) Influence of the patient's head position change :4 cases d) False perforation: 2 cases e) Reduction change: 2 cases 4. In 5 cases with anterior displacement, dual space arthrography gave additional findings such as adhesion within the superior space, which could not be evaluated by single inferior space.

  16. Dual joint space arthrography in temporomandibular joint disorders: Comparison with single inferior joint space arthrography

    International Nuclear Information System (INIS)

    The temporomandibular joint(TMJ) is really a complex of two synovial space separated by fibrocartilaginous disc. Single inferior joint space arthrography is commonly performed for evaluation of TMJ disorders, which is known to be superior in demonstrating joint dynamics. But it reveals only the inferior surface of the disc. Therefore, dual space arthrography is superior to demonstrate the soft tissue anatomic feature of the joint such as disc position and shape. Authors performed 83 TMJ arthrograms in TMJ problems. Initially, the inferior joint space was done and then the superior space was sequentially contrasted. The follow results were noted: 1. In all cases, dual space arthrography revealed accurate disc shape and positions. 2. Concordant findings between the two techniques: 68 cases (82%). Discordance between the two techniques: 15 cases (18%) 3. Possible causes of discordance between inferior and dual space arthrography. a) Normal varians of anterior recess: 3 cases b) Posterior disc displacement: 4 cases c) Influence of the patient's head position change :4 cases d) False perforation: 2 cases e) Reduction change: 2 cases 4. In 5 cases with anterior displacement, dual space arthrography gave additional findings such as adhesion within the superior space, which could not be evaluated by single inferior space

  17. Differences in superior thyroid artery and inferior thyroid artery blood flow spectrum parameters in subacute thyroiditis

    Institute of Scientific and Technical Information of China (English)

    Jin-Bo Li

    2016-01-01

    Objective:To study the differences in superior thyroid artery and inferior thyroid artery blood flow spectrum parameters in subacute thyroiditis. Methods:A Total of 40 cases of patients with subacute thyroiditis and 40 cases of healthy volunteers were selected for study and enrolled in pathology group and control group respectively, color Doppler ultrasonography was conducted to detect peak blood flow velocities (Vmax) of superior thyroid artery and inferior thyroid artery as well as resistance index (RI), and serum was collected to detect thyroid hormone contents, infection indexes and oxidative stress indexes. Results:Peak blood flow velocities Vmax of superior thyroid artery and inferior thyroid artery of pathology group were significantly higher than those of control group, and resistance index RI was not different from that of control group;FT3, FT4, TT3, TT4, ESR, CRP, PCT and MDA of pathology group were significantly higher than those of control group, and SOD and TAOC were significantly lower than those of control group;Vmax of superior thyroid artery and inferior thyroid artery were positively correlated with FT3, FT4, TT3, TT4, ESR, CRP, PCT and MDA, and negatively correlated with SOD and TAOC. Conclusion:Peak blood flow velocities (Vmax) of superior thyroid artery and inferior thyroid artery in subacute thyroiditis are significantly accelerated, Vmax has good consistency with thyroid hormone contents, infection indexes and oxidative stress indexes, and it can accurately assess the severity of the disease.

  18. ROLE OF RADIO FREQUENCY IN THE MANAGEMENT OF INFERIOR TURBINATE HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    Amarnath

    2014-10-01

    Full Text Available BACKGROUND: Surgery of inferior turbinates is a divisive subject. Surgical management includes functional and invasive procedures. Radiofrequency ablation –A Minimally invasive well-designed daycare nasal surgery which also preserves mucosal function of the inferior turbinate. OBJECTIVE: To appraise the efficacy of radiofrequency in the management of inferior turbinate hypertrophy. MATERIALS AND METHODS: current study is a prospective cram conducted in the Department of ENT from August 2013 to August 2014 with 100 patients who had nasal obstruction due to Inferior turbinate hypertrophy and obstinate to medical therapy. Patients were excluded if they had history or physical examination that indicate other causes of nasal obstruction like nasal polyp, nasal tumors, previous nasal surgeries, diabetes mellitus, severe nasal deformities, coagulopathy disorders, severe systemic diseases, radiotherapy to nose. The study was based on history of diagnosis, clinical examination, diagnostic nasal endoscopy and imaging. We used radio frequency generator BM-780II unit with power of 70watt radio wave emission in bipolar mode for 5-9seconds, stopped the emission once visual blanching of mucous membrane occurred. Postoperative follow up scheduled as follows: 1stmonth, 3rdmonth, 6thmonth, 12thmonth. RESULTS: Among 100 patients 92 patients completely relieved of symptoms, 8 patients showed no improvement based on both subjective and objective parameters. CONCLUSIONS: Simple, harmless, minimally invasive, daycare procedure advantages made the Radiofrequency tissue ablation procedure as one amongst the best apt surgical option for management of inferior turbinate hypertrophy and the current study added credit to its efficiency once again.

  19. Inferior Turbinate Flap for Nasal-side Closure of Palatal Fistula in Cleft Patients: Technical Note

    Directory of Open Access Journals (Sweden)

    Amin Rahpeyma

    2014-12-01

    Full Text Available Summary: Residual palatal fistula after repair of palatal cleft is common. Repair of residual oronasal fistula is not always successful. Two-layer closure techniques that close these fistulas with soft tissue are a common practice. Turnover flaps are the most used flaps and often the sole method for nasal-side closure of fistula. Anteriorly based inferior turbinate flap can be used to provide soft tissue for nasal-side closure when turnover flaps will not provide sufficient tissue for this purpose. Under general anesthesia with nasotracheal intubation, inferior turbinate was released from posterior attachment. After removing the inferior conchal bone, mucoperiosteal flap was used for nasal-side closure of anterior palatal fistula in patients with cleft. Anteriorly based inferior turbinate flap was used for nasal-side closure of residual palatal fistula in 3 patients with cleft. Age of the patients was 14, 16, and 18, and recurrence of palatal fistula has not occurred. Anteriorly based inferior turbinate flap is an axial pattern flap with appropriate surface of the paddle and vicinity to the oral cavity roof. It can be used in large anterior, palatal fistula for reconstruction of nasal floor. Considering appropriate another flap for oral side coverage of such fistula is mandatory.

  20. Prognostic significance of right bundle branch block in patients with acute inferior myocardial infarction

    Directory of Open Access Journals (Sweden)

    Iwasaki,Jun

    2009-02-01

    Full Text Available

    There is little information available concerning the influence of right bundle branch block (RBBB on the prognosis of patients with inferior myocardial infarction (MI. In this study we evaluated the influence of RBBB on the short-term prognosis of patients with inferior MI. Our study subjects were 1,265 hospitalized patients with Q wave MI. Patients were divided into 4 groups based on the presence or absence of RBBB and on the location of the infarction. RBBB was classified into 4 categories according to the timing of its appearance and its duration as new permanent, transient, old and age indeterminate. In-hospital death and pulmonary congestion were observed more frequently in patients with RBBB than in those without RBBB. Moreover, in inferior MI as in anterior MI, in-hospital death and pulmonary congestion occurred more frequently in new permanent RBBB patients than in patients with other types of RBBB. Multivariate regression analysis reveals that new permanent RBBB was a strong independent predictor for an adverse short-term prognosis in patients with inferior MI, as well as in patients with anterior MI. New permanent RBBB during inferior MI is a strong independent predictor for increased in-hospital mortality, regardless of the infarction location.

  1. Inferior Alveolar Nerve Injuries Following Implant Placement - Importance of Early Diagnosis and Treatment: a Systematic Review

    Directory of Open Access Journals (Sweden)

    Ilana Shavit

    2014-12-01

    Full Text Available Objectives: The purpose of this article is to systematically review diagnostic procedures and risk factors associated with inferior alveolar nerve injury following implant placement, to identify the time interval between inferior alveolar nerve injury and its diagnosis after surgical dental implant placement and compare between outcomes of early and delayed diagnosis and treatment given based on case series recorded throughout a period of 10 years. Material and Methods: We performed literature investigation through MEDLINE (PubMed electronic database and manual search through dental journals to find articles concerning inferior alveolar nerve injury following implant placement. The search was restricted to English language articles published during the last 10 years, from December 2004 to March 2014. Results: In total, we found 33 articles related to the topic, of which 27 were excluded due to incompatibility with established inclusion criteria. Six articles were eventually chosen to be suitable. The studies presented diagnostic methods of inferior alveolar nerve sensory deficit, and we carried out an assessment of the proportion of patients diagnosed within different time intervals from the time the injury occurred. Conclusions: Various diagnostic methods have been developed throughout the years for dealing with 1 quite frequent complication in the implantology field - inferior alveolar nerve injury. Concurrently, the importance of early diagnosis and treatment was proved repeatedly. According to the results of the data analysis, a relatively high percentage of the practitioners successfully accomplished this target and achieved good treatment outcomes.

  2. Neuropharmacologic characterization of strychnine seizure potentiation in the inferior olive lesioned rat

    International Nuclear Information System (INIS)

    Cerebellar stimulation is associated with anticonvulsant activity in several animal models. There are two afferent inputs to cerebellar Purkinje cells: (1) parallel fibers, which relay mossy fiber input, from brainstem, spinal cord, cerebral cortex and cerebellum, and (2) climbing fibers, arising from the inferior olive. Both climbing and parallel fibers release excitatory amino acid neurotransmitters, which stimulate Purkinje cells and cause GABA release in the deep cerebellar nuclei. Climbing fibers also exert tonic inhibition over Purkinje cell activity by producing an absolute refractory period following stimulation, rendering Purkinje cells unresponsive to parallel fibers. Climbing fiber deafferentation by bilateral inferior olive lesions produced a specific decrease in threshold for strychnine-seizures in the rat. Inferior olive lesions produced no change in threshold to seizures induced by picrotoxin, bicuculline or pentylenetetrazole. Inferior olive lesions also produced abnormal motor behavior including, myoclonus, backward locomotion and hyperextension, which was significantly aggravated by strychnine, brucine, picrotoxin, bicuculline and pentylenetetrazole. Inferior olive lesions produced a significant increase in quisqualate sensitive [3H]AMPA ((Rs)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid) binding to cerebellar membranes. AMPA is a glutamate analog with high affinity for quisqualate sensitive receptors

  3. Classical and numerical approaches to determining V-section band clamp axial stiffness

    Science.gov (United States)

    Barrans, Simon M.; Khodabakhshi, Goodarz; Muller, Matthias

    2014-12-01

    V-band clamp joints are used in a wide range of applications to connect circular flanges, for ducts, pipes and the turbocharger housing. Previous studies and research on V-bands are either purely empirical or analytical with limited applicability on the variety of V-band design and working conditions. In this paper models of the V-band are developed based on the classical theory of solid mechanics and the finite element method to study the behaviour of theV-bands under axial loading conditions. The good agreement between results from the developed FEA and the classical model support the suitability of the latter to modelV-band joints with diameters greater than 110mm under axial loading. The results from both models suggest that the axial stiffness for thisV-band cross section reaches a peak value for V-bands with radius of approximately 150 mmacross a wide range of coefficients of friction. Also, it is shown that the coefficient of friction and the wedge angle have a significant effect on the axial stiffness of V-bands.

  4. Fabrication and characterization of GaN nanowire doubly clamped resonators

    Energy Technology Data Exchange (ETDEWEB)

    Maliakkal, Carina B., E-mail: carina@tifr.res.in; Mathew, John P.; Hatui, Nirupam; Rahman, A. Azizur; Deshmukh, Mandar M.; Bhattacharya, Arnab [Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2015-09-21

    Gallium nitride (GaN) nanowires (NWs) have been intensely researched as building blocks for nanoscale electronic and photonic device applications; however, the mechanical properties of GaN nanostructures have not been explored in detail. The rigidity, thermal stability, and piezoelectric properties of GaN make it an interesting candidate for nano-electromechanical systems. We have fabricated doubly clamped GaN NW electromechanical resonators on sapphire using electron beam lithography and estimated the Young's modulus of GaN from resonance frequency measurements. For wires of triangular cross section with side ∼90 nm, we obtained values for the Young's modulus to be about 218 and 691 GPa, which are of the same order of magnitude as the values reported for bulk GaN. We also discuss the role of residual strain in the nanowire on the resonant frequency and the orientation dependence of the Young's modulus in wurtzite crystals.

  5. Requirements to gap widths and clamping for CO2 laser butt welding

    DEFF Research Database (Denmark)

    Gong, Hui; Juhl, Thomas Winther

    1999-01-01

    In the experimental study of fixturing and gap width requirements a clamping device for laser butt welding of steel sheets has been developed and tested. It has fulfilled the work and made the gap width experiments possible.It has shown that the maximum allowable gap width to some extent is...... inversely related to the welding speed. Also larger laser power leads to bigger allowable gap widths. The focal point position, though, has little influence on the maximum allowable gap width.During analysis X-ray photos show no interior porosity in the weld seam. Other methods have been applied to measure...... responses from variations in welding parameters.The table below lists the results of the study, showing the maximum allowable gap widths and some corresponding welding parameters.Maximum allowable Gap Width; Welding Speed; Laser Power:0.10 mm2 m/min2, 2.6 kW0.15 mm1 m/min2 kW0.20 mm1 m/min2.6 kW0.30 mm0.5 m...

  6. Dynamics of a clamped–clamped microbeam resonator considering fabrication imperfections

    KAUST Repository

    Bataineh, Ahmad M.

    2014-10-18

    We present an investigation into the static and dynamic behavior of an electrostatically actuated clamped–clamped polysilicon microbeam resonator accounting for its fabrication imperfections, which are commonly encountered in similar microstructures. These are mainly because of the initial deformation of the beam due to stress gradient and its flexible anchors. First, we show experimental data of the microbeam when driven electrically by varying the amplitude and frequency of the voltage loads. The results reveal several interesting nonlinear phenomena of jumps, hysteresis, and softening behaviors. Theoretical investigation is then conducted to model the microbeam, and hence, interpret the experimental data. We solve the Eigen value problem governing the natural frequencies analytically. We then utilize a Galerkin-based procedure to derive a reduced order model, which is then used to simulate both the static and dynamic responses. To achieve good matching between theory and experiment, we show that the exact profile of the deformed beam needs to be utilized in the reduced order model, as measured from the optical profiler, combined with a shooting technique simulation, which is capable of tracing the resonant frequency branches under very-low damping conditions.

  7. Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams

    Science.gov (United States)

    Alcheikh, N.; Kosuru, L.; Jaber, N.; Bellaredj, M.; Younis, M. I.

    2016-06-01

    This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped–clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes.

  8. Higher order modes excitation of electrostatically actuated clamped–clamped microbeams: experimental and analytical investigation

    International Nuclear Information System (INIS)

    In this study, we demonstrate analytically and experimentally the excitations of the higher order modes of vibrations in electrostatically actuated clamped–clamped microbeam resonators. The concept is based on using partial electrodes with shapes that induce strong excitation of the mode of interest. The devices are fabricated using polyimide as a structural layer coated with nickel from the top and chrome and gold layers from the bottom. Experimentally, frequency sweeps with different electro-dynamical loading conditions are shown to demonstrate the excitation of the higher order modes of vibration. Using a half electrode, the second mode is excited with high amplitude of vibration compared with almost zero response using the full electrode. Also, using a two-third electrode configuration is shown to amplify the third mode resonance amplitude compared with the full electrode under the same electrical loading conditions. An analytical model is developed based on the Euler–Bernollui beam model and the Galerkin method to simulate the device response. Good agreement between the simulation results and the experimental data is reported. (paper)

  9. Study of Dynamic Behavior of Multilayered Clamped Composite Skewed Hypar Shell Roofs under Impact Load

    Directory of Open Access Journals (Sweden)

    Sanjoy Das Neogi

    2013-01-01

    Full Text Available With advancement in the field of structural engineering, hunt for smarter materials has channelised the research towards the application of composite material. It is the high specific weight and specific stiffness of this material that have drawn the interest of different industrial sectors. Civil engineers also picked up composites to use it as a roofing material. Laminated composite shells, which can cover large column-free area and reduces dead weight of structure, show vulnerability under sudden impact due to their low transverse shear resistances. This study utilises finite element tool to investigate the dynamic response of a multilayered laminated composite hypar shells for fully clamped boundary condition. This class of shells is unique in a sense that the curvature has only the radius of cross curvature and these shells do not admit easy closed form solution particularly when the boundary conditions are complicated. Contact behavior of impactor and impacted mass has been modeled by modified Hertzian contact law and time-dependent equations are solved using Newmark’s time integration technique. Basic aim is to analyse the shell for symmetrically placed multilayered angle and cross ply lamination under different impact velocities.

  10. Analysis of subsynchronous resonance with 5 level diode-clamped VSI based SSSC

    Energy Technology Data Exchange (ETDEWEB)

    Pillai, G.N.; Gupta, H.O. [Indian Inst. of Technology, Roorkee (India). Dept. of Electrical Engineering

    2005-07-01

    Series capacitors are often used in long transmission lines to increase power transfer capability and improve transient stability. This paper presented an analysis of a series compensated power system with a static synchronous series compensator (SSSC). The aim of the study was to investigate the subsynchronous resonance (SSR) characteristics of the system. A 5-level diode clamped voltage source inverter (VSI) with fundamental frequency switching was applied. SSR characteristics were investigated using an eigenvalue analysis technique. The interactions between the compensated network and the generator were examined using the IEEE SSR benchmark system. The system was characterized by 4 unstable torsional modes. A control loop was incorporated in order to understand the behaviour of the overall system, and 2 steady-state operating points were selected. Results of the study showed that torsional or subsynchronous modes can become unstable when parameters of the controllers are not properly considered. It was concluded that the SSSC was capable of damping out the torsional oscillations of the systems. 12 refs., 1 tab., 6 figs.

  11. Active vibration control of clamped beams using positive position feedback controllers with moment pair

    International Nuclear Information System (INIS)

    This paper investigates the active vibration control of clamp beams using positive position feedback (PPF) controllers with a sensor/ moment pair actuator. The sensor/moment pair actuator which is the non-collocated configuration leads to instability of the control system when using the direct velocity feedback (DVFB) control. To alleviate the instability problem, a PPF controller is considered in this paper. A parametric study of the control system with PPF controller is first conducted to characterize the effects of the design parameters (gain and damping ratio in this paper) on the stability and performance. The gain of the controller is found to affect only the relative stability. Increasing the damping ratio of the controller slightly improves the stability condition while the performance gets worse. In addition, the higher mode tuned PPF controller affects the system response at the lower modes significantly. Based on the characteristics of PPF controllers, a multi-mode controllable SISO PPF controller is then considered and tuned to different modes (in this case, three lowest modes) numerically and experimentally. The multi-mode PPF controller can be achieved to have a high gain margin. Moreover, it reduces the vibration of the beam significantly. The vibration levels at the tuned modes are reduced by about 11 dB

  12. A clamp-on ultrasonic cross correlation flow meter for one-phase flow

    Science.gov (United States)

    Worch, A.

    1998-04-01

    The correlation technique presented offers a good possibility for measuring the average rate of flow of fluids through pipes. The only physical parameter required for the measurement principle is the well known distance between the sensors. The new system presented consists of ultrasonic sensors, transforming the natural, stochastic fluctuations of velocity, pressure and density into two signals with a delay time T, and a real-time correlator, extracting the delay time from the signals and calculating the average rate of flow of the fluid. In contrast to established flow measuring methods, no bluff bodies are necessary and electrical conductivity of the fluid is not required. In contrast to time-of-flight flow meters, a small amount of air bubbles or particles causes no signal losses and does not interrupt the measurement process. In this paper a detailed theoretical signal model describing the interaction of sound waves in random continuum and turbulent media will be presented. With this model the phase modulation of the ultrasonic waves and systematic errors can be described and some design parameters can be optimized. Measurements have been carried out with 40 and 50 mm pipe diameters for direct fluid contact and clamp-on transducers. The measurement error of the new flow meter has been found to be less than 2% from the reference value for a Reynolds number range 25 000-250 000 and, even down to a Reynolds number of 4000, it has been found to be less than 3%.

  13. Fabrication and characterization of GaN nanowire doubly clamped resonators

    International Nuclear Information System (INIS)

    Gallium nitride (GaN) nanowires (NWs) have been intensely researched as building blocks for nanoscale electronic and photonic device applications; however, the mechanical properties of GaN nanostructures have not been explored in detail. The rigidity, thermal stability, and piezoelectric properties of GaN make it an interesting candidate for nano-electromechanical systems. We have fabricated doubly clamped GaN NW electromechanical resonators on sapphire using electron beam lithography and estimated the Young's modulus of GaN from resonance frequency measurements. For wires of triangular cross section with side ∼90 nm, we obtained values for the Young's modulus to be about 218 and 691 GPa, which are of the same order of magnitude as the values reported for bulk GaN. We also discuss the role of residual strain in the nanowire on the resonant frequency and the orientation dependence of the Young's modulus in wurtzite crystals

  14. Acute retroperitoneal bleeding due to inferior mesenteric artery aneurysm: Case report

    Directory of Open Access Journals (Sweden)

    Ferrón JA

    2010-06-01

    Full Text Available Abstract Background Visceral artery aneurysms (VAA, although uncommon, are increasingly being detected. We describe a case of spontaneous retroperitoneal hemorrhage from a ruptured IMA aneurysm associated with stenosis of the superior mesenteric artery (SMA and celiac trunk, successfully treated with surgery. Methods A 65-year-old man presented with abdominal pain and hypovolemic shock. Abdominal CT scan showed an aneurysm of the inferior mesenteric artery with retroperitoneal hematoma. In addition, an obstructive disease of the superior mesenteric artery and celiac axis was observed. Results Upon emergency laparotomy a ruptured inferior mesenteric artery aneurysm was detected. The aneurysm was excised and the artery reconstructed by end-to-end anastomosis. Conclusions This report discusses the etiology, presentation, diagnosis and case management of inferior mesenteric artery aneurysms.

  15. Bilateral catheterization of the inferior petrosal sinuses in 23 cases of ACTh-dependent hypercoarisolism

    International Nuclear Information System (INIS)

    Our purpose is to assess the results of catheterization of the inferior petrosal sinuses, a measure that is included in the diagnostic protocol for ACTH-dependent hypercortisolism. We analyzed retrospectively the data obtained for 23 patients (20 women and 3 men) subjected to this procedure. The test was complete (catheterization both inferior petrosal sinuses) in 21 patients (91%). The sensitivity in differentiating between Cushing's disease (n=21) and ectopic ACTH syndrome (n=21) was 95.2% after administration of CRH, with a specificity of 100%, and the positive predictive value for the intra pituitary localization of the micro adenoma (confirmed by histological study in 19 cases) was 61%. Catheterization of the inferior petrosal sinuses shows an elevated sensitivity and specificity in the diagnosis of Cushing's disease, although the positive predictive value for determining the intrapituitary localization of the adenoma is low. (Author) 12 refs

  16. Bilateral inferior dislocation of the hip——a case report

    Institute of Scientific and Technical Information of China (English)

    Kishan R Bhagwat; Bhavuk Garg; Sameer Aggarwal; Mandeep S Dhillon

    2012-01-01

    Inferior dislocation of the hip is the rarest type in hip dislocation.Very few cases have been reported in the anglophonic literature,most of which involved the pediatric age group.Surprisingly,we came across a 30-year-old patient with a bilateral inferior hip dislocation.He had sustained a road traffic accident and the attitude of both hip joints was flexion and abduction.The diagnosis was confirmed by radiographs which revealed the long axis of the femur at an angle of 110 (fight) degrees and 100 (left) degrees respectively away from the axis.Closed reduction under sedation was successfully performed.Skin traction for a period of 6 weeks was advised and the follow-up revealed an excellent result.We present the details of this case,the first of its kind along with a review of the literature,discussing the various modes and mechanisms of injury inducing inferior dislocation of the hip.

  17. Spatial Relationship between Mandibular Third Molars and Inferior Alveolar Nerve using a Volume Rendering Software

    Directory of Open Access Journals (Sweden)

    Shahrokh Nasseri

    2013-12-01

    Full Text Available Precise localization of the third molars in relation to the inferior alveolar nerve canal is critical from a clinical point of view and strongly affects the surgical treatment outcome. Recently, by using three-dimensional modeling software, the relationship of third molar root apices and inferior alveolar nerve canal can be better understood. In this study, the spatial relationship of two surgical sites of 19 impacted third molars with close relationship to the inferior alveolar nerve canal is described by using imaging data from a cone beam computed tomography system. This study aimed to investigate the ability of three-dimensional modeling of tooth-nerve relationship using the data imported to Amira 5.2.2 imaging software

  18. Prevention of iatrogenic inferior alveolar nerve injuries in relation to dental procedures.

    Science.gov (United States)

    Renton, T

    2010-09-01

    This article aims to review current hypotheses on the aetiology and prevention of inferior alveolar nerve (IAN) injuries in relation to dental procedures. The inferior alveolar nerve can be damaged during many dental procedures, including administration of local anaesthetic, implant bed preparation and placement, endodontics, third molar surgery and other surgical interventions. Damage to sensory nerves can result in anaesthesia, paraesthesia, pain, or a combination of the three. Pain is common in inferior alveolar nerve injuries, resulting in significant functional problems. The significant disability associated with these nerve injuries may also result in increasing numbers of medico-legal claims. Many of these iatrogenic nerve injuries can be avoided with careful patient assessment and planning. Furthermore, if the injury occurs there are emerging strategies that may facilitate recovery. The emphasis of this review is on how we may prevent these injuries and facilitate resolution in the early post surgical phase. PMID:21133047

  19. Tonotopic changes in GABA receptor expression in guinea pig inferior colliculus after partial unilateral hearing loss.

    Science.gov (United States)

    Dong, S; Rodger, J; Mulders, W H A M; Robertson, D

    2010-06-25

    Immunohistochemistry was used to investigate the topographic distribution of the alpha1 subunit of the GABA receptor (GABRA1) in guinea pig inferior colliculus after treatments that caused a unilateral loss of peripheral neural sensitivity in the high-frequency regions of the cochlea. Both forms of treatment (direct mechanical lesion of the cochlea and acoustic overstimulation) resulted in a significant decrease in GABRA1 labeling in regions of the contralateral inferior colliculus in which high-frequency sound stimuli are represented. This localized region of reduced inhibitory receptor expression corresponds to the region in which hyperactivity of inferior colliculus neurons has been shown to develop after such treatments. The results strengthen the notion of a causal link between reduced GABRA1 expression and neural hyperactivity in central auditory nuclei and provide a possible mechanism for the development of phantom auditory sensations, or tinnitus. PMID:20438718

  20. Application of inferior major bone flap craniotomy decompression in brain injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To summarize the application of inferior major boneflap craniotomy decompression in brain injury operation.Methods: A retrospective analysis was done in 218 cases with brain injuries who were admitted to our department from January 1995 to December 1999 and treated with the inferior major bone flap craniotomy decompression.Results: Of 218 cases, 121 cases (55.50%) were cured according to GOS, 39 (18.30%) were with good recovery or moderate disability, 13 (5.60%) with severe deformity, 3 (1.40%) vegetative life, the rest 42 (19.20%) died after operation; no encephalocele or incarceration were found.Conclusions: The inferior major bone flap craniotomy decompression can remove hematoma timely and completely, is better than general craniotomy decompression and has a positive effect on brain injuries especially when bone flap is small.

  1. Comparison of dynamic ultrasound and stress radiology for assessment of inferior glenohumeral laxity in asymptomatic shoulders

    International Nuclear Information System (INIS)

    To determine the level of agreement between dynamic ultrasound imaging and stress radiography used for the measurement of inferior glenohumeral laxity in asymptomatic shoulders, and to determine the repeatability of the dynamic ultrasound technique. Using a custom-made stress device to apply an inferior displacement force of 90 N, we assessed 20 asymptomatic male subjects for inferior glenohumeral laxity, using stress radiography and dynamic ultrasound. Paired differences between the two methods were evaluated by the 95% limits of agreement method. At a separate session, 19 subjects had inferior glenohumeral laxity assessed by two observers, using dynamic ultrasound. Inter- and intra-observer repeatability was determined for the ultrasound technique. The mean [± standard deviation (SD)] inferior translation was 4.7 ± 4.1 mm by stress radiography and 4.4 ± 2.3 mm by dynamic ultrasound. The 95% limits of agreement showed good agreement between the two methods. The paired difference between the two measurement methods varied with the magnitude of the measurement (P < 0.001). Intra-observer repeatability of dynamic ultrasound was determined by the use of intra-class correlation coefficients and was 0.94 and 0.89 for the two investigators. Inter-observer repeatability was 0.85. The standard error of the measurement was 0.60 mm and 0.66 mm, for repeated measurements by the two investigators, and 0.85 mm between investigators. Repeatability coefficients demonstrated excellent consistency of measurement between sessions and good consistency between observers. Dynamic ultrasound is a valid and reproducible method for the assessment and quantification of inferior glenohumeral laxity. (orig.)

  2. Non-inferiority and networks: inferring efficacy from a web of data.

    Science.gov (United States)

    Lin, Junjing; Gamalo-Siebers, Margaret; Tiwari, Ram

    2016-01-01

    In the absence of placebo-controlled trials, the efficacy of a test treatment can be alternatively examined by showing its non-inferiority to an active control; that is, the test treatment is not worse than the active control by a pre-specified margin. The margin is based on the effect of the active control over placebo in historical studies. In other words, the non-inferiority setup involves a network of direct and indirect comparisons between test treatment, active controls, and placebo. Given this framework, we consider a Bayesian network meta-analysis that models the uncertainty and heterogeneity of the historical trials into the non-inferiority trial in a data-driven manner through the use of the Dirichlet process and power priors. Depending on whether placebo was present in the historical trials, two cases of non-inferiority testing are discussed that are analogs of the synthesis and fixed-margin approach. In each of these cases, the model provides a more reliable estimate of the control given its effect in other trials in the network, and, in the case where placebo was only present in the historical trials, the model can predict the effect of the test treatment over placebo as if placebo had been present in the non-inferiority trial. It can further answer other questions of interest, such as comparative effectiveness of the test treatment among its comparators. More importantly, the model provides an opportunity for disproportionate randomization or the use of small sample sizes by allowing borrowing of information from a network of trials to draw explicit conclusions on non-inferiority. PMID:26639225

  3. Differentially expressed microRNA cohorts in seed development may contribute to poor grain filling of inferior spikelets in rice

    OpenAIRE

    Peng, Ting; Sun, Hongzheng; Qiao, Mengmeng; Zhao, Yafan; Du, Yanxiu; Zhang, Jing; Li, Junzhou; Tang, Guiliang; Zhao, Quanzhi

    2014-01-01

    Background The inferior spikelets are defined to be those at portions where the grains receive less photosynthetic products during the seed development. The typical inferior spikelets are physically located on the proximal secondary branches in a rice panicle and traditionally characterized by a later flowering time and a slower grain-filling rate, compared to those so-called superior spikelets. Grains produced on the inferior spikelets are consequently under-developed and lighter in weight t...

  4. High quality cord blood banking is feasible with delayed clamping practices. The eight-year experience and current status of the national Swedish Cord Blood Bank.

    Science.gov (United States)

    Frändberg, Sofia; Waldner, Berit; Konar, Jan; Rydberg, Lennart; Fasth, Anders; Holgersson, Jan

    2016-09-01

    The National Swedish Cord Blood Bank (NS-CBB) is altruistic and publicly funded. Herein we describe the status of the bank and the impact of delayed versus early clamping on cell number and volume. Cord Blood Units (CBUs) were collected at two University Hospitals in Sweden. Collected volume and nucleated cell content (TNC) were investigated in 146 consecutive Cord Blood (CB) collections sampled during the first quarter of 2012 and in 162 consecutive CB collections done in the first quarter of 2013, before and after clamping practices were changed from immediate to late (60 s) clamping. NS-CBB now holds close to 5000 units whereof 30 % are from non-Caucasian or mixed origins. Delayed clamping had no major effect on collection efficiency. The volume collected was slightly reduced (mean difference, 8.1 ml; 95 % CI, 1.3-15.0 ml; p = 0.02), while cell recovery was not (p = 0.1). The proportion of CBUs that met initial total TNC banking criteria was 60 % using a TNC threshold of 12.5 × 10(8), and 47 % using a threshold of 15 × 10(8) for the early clamping group and 52 and 37 % in the late clamping group. Following implementation of delayed clamping practices at NS-CBB; close to 40 % of the collections in the late clamping group still met the high TNC banking threshold and were eligible for banking, implicating that that cord blood banking is feasible with delayed clamping practices. PMID:27342904

  5. Firing clamp: A novel method for single-trial estimation of excitatory and inhibitory synaptic neuronal conductances

    Directory of Open Access Journals (Sweden)

    Anton Chizhov

    2014-03-01

    Full Text Available Understanding non-stationary neuronal activity as seen in vivo requires estimation of both excitatory and inhibitory synaptic conductances from a single trial of recording. We propose a new intracellular recording method for this purpose called “firing clamp”. Synaptic conductances are estimated from the characteristics of artificially evoked probe spikes, namely the spike amplitude and the mean subthreshold potential, which are sensitive to both excitatory and inhibitory synaptic input signals. The probe spikes, timed at a fixed rate, are evoked in the dynamic-clamp mode by injected meander-like current steps, with the step duration depending on neuronal membrane voltage. We test the method with perforated-patch recordings from isolated cells stimulated by external application or synaptic release of transmitter, and validate the method with simulations of a biophysically-detailed neuron model. The results are compared with the conductance estimates based on conventional current-clamp recordings.

  6. Fatigue Property of Open-Hole Steel Plates Influenced by Bolted Clamp-up and Hole Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Zhi-Yu Wang

    2016-08-01

    Full Text Available Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared with the contemporary test data. The analysis results show that the presence of draglines greatly influences the fatigue crack initiation at the open-hole cut by laser. The bolted clamp-up condition greatly enhances the stiffness and the fatigue life of the open-hole details. A discussion is also made from a comparison with the referred fatigue life of hole fabrication details, such as the influence of plate thickness and plasma cutting, drilling and oxy-fuel gas cutting, with the details studied herein. This work could enhance the understanding of the fatigue property and design of such details.

  7. IMPROVE THE KINETIC PERFORMANCE OF THE PUMP CONTROLLED CLAMPING UNIT IN PLASTIC INJECTION MOLDING MACHINE WITH ADAPTIVE CONTROL STRATEGY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated.Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment. The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.

  8. A propagation time difference evaluation for a clamp-on ultrasonic flowmeter for low-pressure gas

    Science.gov (United States)

    Nishiguchi, Hiroshi; Sawayama, Toshiyuki; Nagamune, Kouki

    2016-07-01

    We have been studying the development of a clamp-on ultrasonic flowmeter for measuring the gas flow rate, especially at low-pressure gas such as atmospheric pressure. In this study, we evaluated the propagation time difference of ultrasonic wave for measuring the airflow at atmospheric pressure. We placed a pair of ultrasonic transducers outside a pipe and generated ultrasonic waves aslant to the flow direction. We observed the propagation time difference of the ultrasonic wave as a function of the gas flow velocity, and found that the difference was proportional to the gas flow. Therefore, it was shown that we were able to measure the atmospheric pressure gas flow rate with a clamp-on ultrasonic flowmeter. Moreover, we evaluated the dependency of ultrasonic wave intensity on gas pressure.

  9. Retained Intra-Abdominal Surgical Clamp Complicating Emergency Laparotomy: Incidental Finding on Hysterosalpingogram for Evaluation of Tubal Infertility

    Directory of Open Access Journals (Sweden)

    Adebiyi Gbadebo Adesiyun

    2014-01-01

    Full Text Available The finding of intraperitoneal foreign body complicating surgical intervention broadly remains as an issue of safety in the operative room, a source of emotive concern for the patient, and an upsetting but equally embarrassing situation to the surgeon and the team. However, in the media world, it is a source of sumptuous and captivating headline on the newspaper and to the legal profession, an attractive case to prosecute. A middle age teacher presented with secondary infertility. She had emergency laparotomy fifteen years ago for ruptured tubal ectopic pregnancy in a private hospital and postoperative period was uneventful. Amongst other investigations to find out the cause of infertility, she had hysterosalpingography and a radio-opaque clamp was visualized on the films. She was counselled and had laparotomy. A pair of surgical Kocher clamps was retrieved buried in the mesentery.

  10. Three Phase Two Leg Neutral Point Clamped Converter with output DC Voltage Regulation and Input Power Factor Correction

    Directory of Open Access Journals (Sweden)

    Bogimi Sirisha

    2012-03-01

    Full Text Available In this paper, a three-phase two leg neutral point clamped (NPC converter is presented for power factor correction and dc-link voltage regulation. The adopted converter has simpler circuit configuration and less number of power switches compared to three-level PWM converter. In this circuit configuration, only eight power switches and four clamping diodes with voltage stress of half the dc bus voltage are used. A simplified space vector pulse width modulation scheme (SVPWM is also adopted to track the line current commands. A reference voltage vector is generated on the ac terminal for drawing the sinusoidal line currents with unity power factor. This algorithm reduces the time required to calculate the switching time durations of voltage vectors. The simulation results have been presented to verify the validity and effectiveness of the proposed control strategy.

  11. Unusual facial pain secondary to inferior alveolar nerve compression caused by impacted mandibular second molar

    Directory of Open Access Journals (Sweden)

    Urvashi Sharma

    2014-01-01

    Full Text Available Symptoms of inferior alveolar nerve (IAN compression are reported during endodontic procedures, placement of implants, third molar surgeries, inferior alveolar nerve block injections, trauma, orthognathic injuries, ablative surgeries or use of medicaments. Presented is a rare case of a 15-year-old girl who reported severe pain in relation to an impacted permanent mandibular left second molar, the roots of which had entrapped the mandibular canal causing compression of IAN. Timely surgical intervention and sectional removal of the impacted molar is indicated to relieve the symptoms and avoid permanent damage to the nerve.

  12. Advanced Hepatocellular Carcinoma with Subtotal Occlusion of the Inferior Vena Cava and a Right Atrial Mass

    Directory of Open Access Journals (Sweden)

    Christian Steinberg

    2013-01-01

    Full Text Available Hepatocellular carcinoma usually metastasizes to regional lymph nodes, lung, and bones but can rarely invade the inferior vena cava with intravascular extension to the right atrium. We present the case of a 75-year-old man who was admitted for generalized oedema and was found to have advanced HCC with invasion of the inferior vena cava and endovascular extension to the right atrium. In contrast to the great majority of hepatocellular carcinoma, which usually develops on the basis of liver cirrhosis due to identifiable risk factors, none of those factors were present in our patient.

  13. Huge Trombus including Left Renal Vein, Ovarian Vein, and Inferior Vena Cava Mimicking Renal Colic

    Directory of Open Access Journals (Sweden)

    Sakir Ongun

    2014-01-01

    Full Text Available A 31-year-old female presented with acute left flank pain; she had a C/S at the postpartum day 24. Ureteral stone was suspected but ultrasound examination was normal. Then Doppler ultrasound revealed a trombus in left renal vein and inferior vena cava. Contrast enhanced MDCT scan showed swelled and nonfunctional left kidney, a trombus including distal part of left ovarian vein, left renal vein, and inferior vena cava. We started anticoagulation treatment. Further examination revealed diagnosis of chronic myeloproliferative disease. The trombus was completely recanalized at 3-month followup.

  14. Consideraciones sobre el Cretácico inferior de la zona Jumilla-Yecla

    OpenAIRE

    Vilas, Lorenzo; Arias, C; Elizaga, E.; García de Domingo, A.; López-Olmedo, F.

    1982-01-01

    [ES] Se estudia el Cretácico inferior y sus relaciones con el superior y con el Jurásico en una zona alargada en sentido SO-NE, que abarca aproximadamente desde Socovos hasta Villena, con una anchura variable delimitada, en general, por fracturas y que se denomina no observándose para el Cretácico inferior tránsito gradual con dichas zonas limítrofes según la posición relativa que ocupan actualmente. Por último, cabe destacar la abundancia de terrígenos en el Barremíense ...

  15. Colgajos de perforantes de las arterias epigástricas inferiores profunda y superficial Deep and superficial inferior epigastric artery perforator flaps

    Directory of Open Access Journals (Sweden)

    A. R. Gagnon

    2006-12-01

    Full Text Available Con el desarrollo de los colgajos miocutáneos de recto abdominal (TRAM, el abdomen inferior ha sido reconocido como la principal área dadora de tejidos autólogos de alta calidad, especialmente útiles en reconstrucción mamaria. Más recientemente la habilidad para obtener componentes adiposocutáneos similares sin sacrificar el músculo recto ha revolucionado el campo de la Cirugía Reconstructiva. El advenimiento de los colgajos de perforantes ha permitido a los cirujanos plásticos lograr los mismos buenos resultados estéticos que con los colgajos miocutáneos tradicionales, pero con un considerable descenso en la morbilidad del área donante. Con los colgajos de perforantes de la arteria epigástrica inferior profunda (DIEP y de la arteria epigástrica inferior superficial (SIEA, los pacientes han incrementado sus opciones de reconstrucción. Este artículo revisa la anatomía quirúrgica de la pared abdominal relativa a los colgajos SIEA y DIEP. Se explican detalladamente los pasos principales para la preparación preoperatoria, la técnica quirúrgica y los cuidados postoperatorios. Se discuten las ventajas y desventajas y se presen- tan los trucos técnicos que pueden ayudar a mejorar el resultado final. Además se ilustran con ayuda de casos clínicos las indicaciones típicas y atípicas.Following the development of the transverse rectus abdominis myocutaneous (TRAM flap, the lower abdomen has been recognized as a prime source of high quality autogenous tissue, especially useful in breast reconstruction. More recently, the ability to harvest a similar adipocutaneous component without sacrifice of the rectus muscle has revolutionized the field of reconstructive surgery. The advent of perforator flaps has allowed plastic surgeons to achieve the same highly esthetic results as with the former myocutaneous flaps while significantly decreasing the donor site morbidity. With the deep inferior epigastric artery perforator (DIEP flap and

  16. Comparative Study through Modal Analysis of Thin Trapeze Shape Plates Clamped on Contour without and with Damages

    Directory of Open Access Journals (Sweden)

    Cornel Hatiegan

    2015-09-01

    Full Text Available This paper presents a comparative study of four types of plates in the form of trapeze, clamped on the contour, regarding modal analysis. After this analysis, there have been obtained the Eigen frequencies for 30 vibration modes between the limits 183.37 ÷ 1206.3 [Hz]. For these results there has been computed the absolute variation, respectively the relative frequency shifts of the analyzed plates.

  17. From understanding cellular function to novel drug discovery: the role of planar patch-clamp array chip technology

    Directory of Open Access Journals (Sweden)

    Christophe ePy

    2011-10-01

    Full Text Available All excitable cell functions rely upon ion channels that are embedded in their plasma membrane. Perturbations of ion channel structure or function result in pathologies ranging from cardiac dysfunction to neurodegenerative disorders. Consequently, to understand the functions of excitable cells and to remedy their pathophysiology, it is important to understand the ion channel functions under various experimental conditions – including exposure to novel drug targets. Glass pipette patch-clamp is the state of the art technique to monitor the intrinsic and synaptic properties of neurons. However, this technique is labor-intensive and has low data throughput. Planar patch-clamp chips, integrated into automated systems, offer high throughputs but are limited to isolated cells from suspensions, resulting in questionable models of true physiological function, and are unsuitable for studies involving neuronal communication. Multi-electrode arrays (MEA, in contrast, have the ability to monitor network activity by measuring local field potentials from multiple extracellular sites, but specific ion channel activity is challenging to extract from these multiplexed signals. Here we describe a novel planar patch-clamp chip technology that enables the simultaneous high resolution electrophysiological interrogation of individual neurons at multiple sites in synaptically connected neuronal networks, thereby combining the advantages of MEA and patch-clamp techniques. Each neuron can be probed through an aperture that connects to a dedicated subterranean microfluidic channel. Neurons growing in networks are aligned to the apertures by physisorbed or chemisorbed chemical cues. In this review, we describe the design and fabrication process of these chips, the approach to the chemical patterning for cell placement, and present physiological data from cultured neuronal cells.

  18. Voltage Clamp Fluorimetry Reveals a Novel Outer Pore Instability in a Mammalian Voltage-gated Potassium Channel

    OpenAIRE

    Vaid, Moninder; Claydon, Thomas W.; Rezazadeh, Saman; Fedida, David

    2008-01-01

    Voltage-gated potassium (Kv) channel gating involves complex structural rearrangements that regulate the ability of channels to conduct K+ ions. Fluorescence-based approaches provide a powerful technique to directly report structural dynamics underlying these gating processes in Shaker Kv channels. Here, we apply voltage clamp fluorimetry, for the first time, to study voltage sensor motions in mammalian Kv1.5 channels. Despite the homology between Kv1.5 and the Shaker channel, attaching TMRM ...

  19. Vascular relaxation of canine visceral arteries after ischemia by means of supraceliac aortic cross-clamping followed by reperfusion

    Directory of Open Access Journals (Sweden)

    Dalio Marcelo B

    2010-07-01

    Full Text Available Abstract Background The supraceliac aortic cross-clamping can be an option to save patients with hipovolemic shock due to abdominal trauma. However, this maneuver is associated with ischemia/reperfusion (I/R injury strongly related to oxidative stress and reduction of nitric oxide bioavailability. Moreover, several studies demonstrated impairment in relaxation after I/R, but the time course of I/R necessary to induce vascular dysfunction is still controversial. We investigated whether 60 minutes of ischemia followed by 30 minutes of reperfusion do not change the relaxation of visceral arteries nor the plasma and renal levels of malondialdehyde (MDA and nitrite plus nitrate (NOx. Methods Male mongrel dogs (n = 27 were randomly allocated in one of the three groups: sham (no clamping, n = 9, ischemia (supraceliac aortic cross-clamping for 60 minutes, n = 9, and I/R (60 minutes of ischemia followed by reperfusion for 30 minutes, n = 9. Relaxation of visceral arteries (celiac trunk, renal and superior mesenteric arteries was studied in organ chambers. MDA and NOx concentrations were determined using a commercially available kit and an ozone-based chemiluminescence assay, respectively. Results Both acetylcholine and calcium ionophore caused relaxation in endothelium-intact rings and no statistical differences were observed among the three groups. Sodium nitroprusside promoted relaxation in endothelium-denuded rings, and there were no inter-group statistical differences. Both plasma and renal concentrations of MDA and NOx showed no significant difference among the groups. Conclusion Supraceliac aortic cross-clamping for 60 minutes alone and followed by 30 minutes of reperfusion did not impair relaxation of canine visceral arteries nor evoke biochemical alterations in plasma or renal tissue.

  20. Carrier-based PWM strategies for the comprehensive capacitor voltage balance of multilevel multileg diode-clamped converters

    OpenAIRE

    Busquets Monge, Sergio; Ruderman, Alex

    2010-01-01

    This paper presents four carrier-based PWM strategies for diode-clamped converters of any number of levels and any number of legs (phases). These carrier-based PWM strategies guarantee the dc-link capacitor voltage balance in every switching cycle without the need of additional hardware and with low dc-link capacitance values for any modulation index and load, provided that the sum of leg currents equals zero. The performance of the presented carrier-based PWM strategies,...

  1. Inter-layer slide and stress relaxation in a bilayer fluid membrane in the patch-clamp setting

    OpenAIRE

    Mukhin, Sergei I.; Baoukina, Svetlana V.

    2003-01-01

    Protein mechanosensitive channels (MS) are activated by tension transmitted through the lipid bilayer. We propose a theory of lateral stress relaxation in a bilayer lipid membrane exposed to external pressure pulse in the patch-clamp experimental setting. It is shown that transfer of lipid molecules into a strained region is thermodynamically advantageous due to local decrease of the stress. Considered stress relaxation mechanism may explain recent experimental observations (Davidson and Mart...

  2. Clamp ablation of the testes compared to bilateral orchiectomy as androgen deprivation therapy for advanced prostate cancer

    OpenAIRE

    AD Zarrabi; CF Heyns

    2011-01-01

    PURPOSE: Burdizzo clamp ablation of the testes (CAT) may provide an incisionless, cost-effective form of androgen deprivation therapy (ADT) in men with adenocarcinoma of the prostate (ACP) who find bilateral orchiectomy (BO) unacceptable or can not afford medical ADT. The aim of this study was to compare CAT with BO as primary ADT in men with ACP. MATERIALS AND METHODS: Written, informed consent was obtained from men with locally advanced or metastatic ACP. Patients were prospectively randomi...

  3. RELATIONSHIP OF TIMING OF CORD CLAMP TO THE NEONATAL HA EMATOLOGICAL STATUS OF NEWBORN - A COMPARISON IN TERM BABIES BORN VIA NORMAL VAGINAL DELIVERY & CESAREAN DELIVERY

    Directory of Open Access Journals (Sweden)

    Madhur

    2014-02-01

    Full Text Available AIM : To study the relationship of timing of cord clamping to the hematocrit and hemoglobin values within 0 - 6 hours of life - comparison in term normal vaginal delivery to cesarean delivery . Clamping and cutting of the umbilical cord at birth is by far the oldest and most prevalent intervention i n humans. In spite of that the optimal time of cord clamping has been a con troversial issue for decades . There are no formal practice guidelines as such but practitioners in western countries clamp and cut the cord immediately after birth while the pr actic e worldwide is variable . OBJECTIVE : To study and observe the effect of timing of cord clamping on neonatal hematocrit and hemoglobin within 0 – 6 hours of life & compare in term normal vaginal delivery to cesarean delivery. METHODS : This is a randomized , c ontrol trial conducted in the Dept. of Pediatrics and Dept. of Gyn & Obst. , Mahatma Gandhi Medical College & hospital. Jaipur , between 20 th to 30 th September 2013. Patients admitted in labor ward were selected according to the inclusion criteria of the study. Group A included 50 term normal vaginal delivery babies in whom the time of cord clamp from birth was noted and a cord blood or venous blood of baby was send within 6 hours of life for estimation of hematocrit & hemoglobin values , while group B incl uded 50 term babies born via cesarean section and same procedure was followed . RESULTS : It was observed that delayed cord clamping ( at 1 or 2 minutes after birth in healthy term newborns increases hematocrit & hemoglobin value within physiologic ranges wi thout causing any harmful effects . Umbilical cord clamping at 1 minute of life increases hematocrit in no more than much 8 - 10 points compared with cord clamping in first 15 seconds after birth. As per normal practice of early cord clamping in Indian scena rio timing of cord clamping in term normal vaginal delivery was at least more than 30 seconds to 1 minute while in term

  4. Solution study of the Escherichia coli DNA polymerase III clamp loader reveals the location of the dynamic ψχ heterodimer

    Directory of Open Access Journals (Sweden)

    Farzaneh Tondnevis

    2015-09-01

    Full Text Available Several X-ray crystal structures of the E. coli core clamp loader containing the five core (δ′, δ, and three truncated γ subunits have been determined, but they lack the ψ and χ subunits. We report the first solution structure of the complete seven-subunit clamp loader complex using small angle X-ray scattering. This structure not only provides information about the location of the χ and ψ subunits but also provides a model of the dynamic nature of the clamp loader complex.

  5. A DC-Link Voltage Self-Balance Method for a Diode-Clamped Modular Multilevel Converter With Minimum Number of Voltage Sensors

    DEFF Research Database (Denmark)

    Gao, Congzhe; Jiang, Xinjian; Li, Yongdong; Chen, Zhe; Liu, Jingyun

    2013-01-01

    the developed control strategy, the proposed diode-clamped circuit becomes a controllable closed loop which enables the capacitor voltages to be clamped by low power rating clamping diodes. The proposed topology and control strategy has quicker response and requires much fewer voltage sensors than the...... normally used traditional method; therefore, the system performance improvement and cost reduction are expected. Based on the proposed DCM2C, a novel N +1-level cascade multilevel topology is proposed for a cascade active power filter (CS-APF). The simulation and experimental results from the CS-APF have...

  6. Establishing a Methodology for Experimental Measuring of Loads and Stress State Determination on Clamp Dogs of Carrying Structures

    Directory of Open Access Journals (Sweden)

    E. Hristovska

    2015-12-01

    Full Text Available The experimental measuring of working loads upon the parts of rotating excavator is a complicated procedure given the complexity of the construction of the excavator and the specificity of exploitation conditions. Therefore, there are no uniform solutions and methods for this purpose, and any proposed solution is of great benefit to excavator users, as well to science studying this issue. This paper presents a preset methodology for measuring working loads of the clamp dogs on the carrying structure of the working wheel at the excavator used in surface coal mining. This methodology uses the default settings implicit to the strain gage method, which records the stresses resulting from external loads occurring within the clamp dogs’ material using strain gages and measuring equipment. Within this concept, the paper shows the manner of determining the measuring points and setting up the strain gages on both clamp dogs, the connecting with the measuring installation and the equipment. Employing diagrams, the paper presents the measurement results of static and dynamic loads, as well as induced stress state by them.

  7. A clinical comparative analysis of crush/clamp, stapler, and dissecting sealer hepatic transection methods1

    Science.gov (United States)

    Earl, T. Mark; Chari, Ravi S.; Gorden, D. Lee; Merchant, Nipun B.; Wright, J. Kelly; Feurer, Irene D.; Pinson, C. Wright

    2008-01-01

    Introduction. Several methods for hepatic parenchymal division exist. The primary aim was to assess differences in postoperative bile leaks, operative blood loss, and margin status between three transection methods: crush/clamp (CC), stapler (SP), or dissecting sealer (DS). Methods. A single institution, retrospective cohort study was performed on data collected over a three-year period in patients undergoing elective liver resection using the CC, SP, or DS. Patients were excluded if multiple methods of transection were used or for intraoperative death. The association of bile leak with transection type was assessed. A logistic regression model was tested to assess if blood loss was associated with the covariates of transection method, use of portal inflow occlusion, extent of liver resection, and other concurrent major operations. Results. Analyses included 141 patients. The stapler method was quicker than the other methods (p=0.01). The risk of postoperative bile leak was no different between CC, SP, and DS transection methods (p=0.23). There was no difference in mean blood loss or transfusions; however, hepatectomies performed with DS were associated with an increased risk of blood loss ≥1000 mL compared to CC (p=0.04). There were no differences in mean surgical margin between the three methods. Conclusion. The risk of bile leaks was not different between the three methods. While mean blood loss was similar, hepatectomy performed with the DS was associated with an increased risk of having operative blood loss ≥1000 mL compared to CC. Margins were equal by all methods. The stapler method was quicker. PMID:18982146

  8. Development of the clamp-on ultrasound flow meter for steam in pipe

    International Nuclear Information System (INIS)

    Gas flow metering of a pipe flow such as chemical plant, reactors and power stations is one of the significant techniques that enable to diagnose and control the behavior of working fluid, and to govern the entire fluid system in the industrial facilities. In order to operate the aforementioned systems, the precise measurement of the flow rate is required. The conventional flow meter, however, needs the installation of the spool piece that disturbs the stable and continuous operation of the plants. i.e., the destructive set-up process of the measurement section is necessary. In this study, the novel ultrasound gas flow metering technique has been developed by means of the clamp-on ultrasound transmitter and receivers. By the numerical simulation, the ultrasound propagation through the gas and metal pipe was firstly investigated. The effects of the external damping material, applicable vapor pressure range as well as the appropriate shape of the acoustic lens were analyzed that was followed by the feasibility test of the actual measurement system. The pressurized vapor flow was used as a working fluid. Pressure and sensor dimension were varied to compare the efficiency of the ultrasound transmission between transducers. The temperature of the working fluid was beyond 373 K. The ultrasound pulsar-receiver was used that could control the frequency, amplitude and phase of the burst sinusoids. The signal processing algorithm was developed in order to discriminate the direct signal through the gaseous flow from the unwanted circumference noise through the solid stainless pipe. The linear relation between flow rate and ultrasound peak shift was confirmed. (author)

  9. Dynamics of T-Junction Solution Switching Aimed at Patch Clamp Experiments.

    Directory of Open Access Journals (Sweden)

    Jerónimo A Auzmendi

    Full Text Available Solutions exchange systems are responsible for the timing of drug application on patch clamp experiments. There are two basic strategies for generating a solution exchange. When slow exchanges are bearable, it is easier to perform the exchange inside the tubing system upstream of the exit port. On the other hand, fast, reproducible, exchanges are usually performed downstream of the exit port. As both strategies are combinable, increasing the performance of upstream exchanges is desirable. We designed a simple method for manufacturing T-junctions (300 μm I.D. and we measured the time profile of exchange of two saline solutions using a patch pipette with an open tip. Three factors were found to determine the timing of the solution switching: pressure, travelled distance and off-center distance. A linear relationship between the time delay and the travelled distance was found for each tested pressure, showing its dependence to the fluid velocity, which increased with pressure. The exchange time was found to increase quadratically with the delay, although a sizeable variability remains unexplained by this relationship. The delay and exchange times increased as the recording pipette moved away from the center of the stream. Those increases became dramatic as the pipette was moved close to the stream borders. Mass transport along the travelled distance between the slow fluid at the border and the fast fluid at the center seems to contribute to the time course of the solution exchange. This effect would be present in all tubing based devices. Present results might be of fundamental importance for the adequate design of serial compound exchangers which would be instrumental in the discovery of drugs that modulate the action of the physiological agonists of ion channels with the purpose of fine tuning their physiology.

  10. Hebbian induction of LTP in visual cortex: perforated patch-clamp study in cultured neurons.

    Science.gov (United States)

    Otsu, Y; Kimura, F; Tsumoto, T

    1995-12-01

    1. To see whether presynaptic activation paired with postsynaptic depolarization is necessary for the induction of long-term potentiation (LTP) in visual cortex or whether an activation of postsynaptic receptors in conjunction with depolarization is sufficient, we carried out perforated patch-clamp recordings with nystatin from cultured cortical neurons of rats. 2. Recorded neurons were monosynaptically activated either by electrical stimulation of an adjacent neuron or by direct activation of glutamate on "hot spots" of dendrites through iontophoresis or pressure ejection. In experiments in which cultured neurons were stained immunocytochemically with antibody against synaptophysin after electrophysiological recordings, hot spots were found to correspond to probable synaptic sites. 3. Excitatory postsynaptic currents (EPSCs) evoked by test stimulation applied to the adjacent neuron at 0.1 Hz were recorded at a holding potential of -60 or -70 mV for 5-10 min after an establishment of the whole cell recording configuration. Then, stimulation was paired with postsynaptic depolarization (0 mV for 200 ms) at 1 Hz for 30 or 60 s. LTP of EPSCs was induced in 7 of the 15 cells from which stable recordings were obtained for 18-30 min after pairing. 4. When postsynaptic depolarization was paired with direct glutamate application in the absence of presynaptic stimulation in 12 cells, only 1 showed LTP. Postsynaptic depolarization alone did not induce LTP in any of the six cells tested. Also, presynaptic stimulation alone did not induce LTP in any of the five cells tested. 5. These results suggest that the concurrent activation of presynaptic elements with postsynaptic depolarization is necessary for the induction of LTP in visual cortex. PMID:8747204

  11. Topographical projection from the superior colliculus to the nucleus of the brachium of the inferior colliculus in the ferret: convergence of visual and auditory information.

    Science.gov (United States)

    Doubell, T P; Baron, J; Skaliora, I; King, A J

    2000-12-01

    The normal maturation of the auditory space map in the deeper layers of the ferret superior colliculus (SC) depends on signals provided by the superficial visual layers, but it is unknown where or how these signals influence the developing auditory responses. Here we report that tracer injections in the superficial layers label axons with en passant and terminal boutons, both in the deeper layers of the SC and in their primary source of auditory input, the nucleus of the brachium of the inferior colliculus (nBIC). Electron microscopy confirmed that biocytin-labelled SC axons form axodendritic synapses on nBIC neurons. Injections of biotinylated dextran amine in the nBIC resulted in anterograde labelling in the deeper layers of the SC, as well as retrogradely labelled superficial and deep SC neurons, whose distribution varied systematically with the rostrocaudal placement of the injection sites in the nBIC. Topographical order in the projection from the SC to the ipsilateral nBIC was confirmed using fluorescent microspheres. We demonstrated the existence of functional SC-nBIC connections by making whole-cell current-clamp recordings from young ferret slices. Both monosynaptic and polysynaptic EPSPs were generated by electrical stimulation of either the superficial or deep SC layers. In addition to unimodal auditory units, both visual and bimodal visual-auditory units were recorded in the nBIC in vivo and their incidence was higher in juvenile ferrets than in adults. The SC-nBIC circuit provides a potential means by which visual and other sensory or premotor signals may be delivered to the nBIC to calibrate the representation of auditory space. PMID:11122340

  12. Age-Related Increase in Inferior Frontal Gyrus Activity and Social Functioning in Autism Spectrum Disorder

    NARCIS (Netherlands)

    Bastiaansen, Jojanneke A.; Thioux, Marc; Nanetti, Luca; van der Gaag, Christiaan; Ketelaars, Cees; Minderaa, Ruud; Keysers, Christian

    2011-01-01

    Background: Hypoactivation of the inferior frontal gyrus during the perception of facial expressions has been interpreted as evidence for a deficit of the mirror neuron system in children with autism. We examined whether this dysfunction persists in adulthood, and how brain activity in the mirror ne

  13. Moyamoya disease associated with an anterior inferior cerebellar artery arising from a persistent trigeminal artery

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, A.; Sawada, A.; Takase, Y.; Kudo, S. [Department of Radiology, Saga Medical School, 5-1-1, Nabeshima, Saga, 849-8501 (Japan); Koizumi, T. [Department of Neurosurgery, Saga Medical School, 5-1-1, Nabeshima, Saga, 849-8501 (Japan)

    2002-07-01

    The authors present a case of moyamoya disease associated with a persistent trigeminal artery from which the anterior inferior cerebellar artery arose. We reviewed previously reported cases of moyamoya disease associated with persistent carotid-basilar arterial anastomosis and investigated the embryology of this rare arterial variation. (orig.)

  14. A follow-up study of cognitive impairment due to inferior capsular genu infarction.

    Science.gov (United States)

    Madureira, S; Guerreiro, M; Ferro, J M

    1999-09-01

    Abulia, memory loss, other cognitive deficits, and behavioral changes consistent with dementia can follow an inferior capsular genu infarction, but only little is known about the time course of these disturbances. The present study describes the long-term outcome of cognitive defects in four patients with inferior capsular genu infarction who underwent a neuropsychological examination within 3 and 12 months of onset. Three patients had infarcts in the inferior genu of the left internal capsule and had similar symptoms in the acute phase: disorientation, memory loss, language impairment, and behavioral changes. The patient with right-side infarct showed memory impairment and behavioral changes. Three patients had deficits in one or more cognitive domains on the first assessment, but none was demented. By the second evaluation all subjects had improved. In two patients there were a moderate memory defect persisted and a language disturbance. Improvement in these disturbances during long-time follow-up demonstrates that there are alternative pathways that reestablish the functional connections damaged by the strategically located capsular genu infarct. Inferior capsular genu infarction is not a cause of persisting "strategic infarct dementia." PMID:10525972

  15. Evaluation of macular thickness change after inferior oblique muscle recession surgery

    Directory of Open Access Journals (Sweden)

    Ece Turan-Vural

    2014-01-01

    Full Text Available Purpose: This study aimed to evaluate the changes in macular thickness following inferior oblique muscle recession surgery. Materials and Methods: Thirty-eight eyes from 21 patients undergoing ocular muscle surgery were included. Patients were grouped into three groups based on the type of surgical intervention: Group I (n = 12, inferior oblique recession surgery alone; Group II (n = 12, inferior oblique plus horizontal muscle surgery; Group III (n = 14, horizontal muscle surgery alone. Each eye was scanned using the optical coherence tomography (OCT device preoperatively and on the first postoperative day to measure macular thickness. Results: Following surgery, a significant increase in foveal thickness occurred in Group I (P < 0.05 and Group II (P < 0.01. In addition, a statistically significant difference was observed between the groups with regard to the increase in foveal thickness (P = 0.016, with significantly lower changes in Group III. Conclusion: Our findings suggested that inferior oblique muscle recession surgery is associated with an increase in macular thickness.

  16. Effects of sexual reproduction of the inferior competitor Brachionus calyciflorus on its fitness against Brachionus angularis

    Science.gov (United States)

    Li, Chen; Niu, Cuijuan

    2015-03-01

    Sexual reproduction adversely affects the population growth of cyclic parthenogenetic animals. The density-dependent sexual reproduction of a superior competitor could mediate the coexistence. However, the cost of sex may make the inferior competitor more vulnerable. To investigate the effect of sexual reproduction on the inferior competitor, we experimentally paired the competition of one Brachionus angularis clone against three Brachionus calyciflorus clones. One of the B. calyciflorus clones showed a low propensity for sexual reproduction, while the other two showed high propensities. The results show that all B. calyciflorus clones were excluded in the competition for resources at low food level. The increased food level promoted the competition persistence, but the clones did not show a clear pattern. Both the cumulative population density and resting egg production increased with the food level. The cumulative population density decreased with the mixis investment, while the resting egg production increased with the mixis investment. A trade-off between the population growth and sexual reproduction was observed in this research. The results indicate that although higher mixis investment resulted in a lower population density, it would not determinately accelerate the exclusion process of the inferior competitor. On the contrary, higher mixis investment promoted resting egg production before being excluded and thus promised a long-term benefit. In conclusion, our results suggest that mixis investment, to some extent, favored the excluded inferior competitor under fierce competition or some other adverse conditions.

  17. Effects of Category Learning on the Stimulus Selectivity of Macaque Inferior Temporal Neurons

    Science.gov (United States)

    De Baene, Wouter; Ons, Bart; Wagemans, Johan; Vogels, Rufin

    2008-01-01

    Primates can learn to categorize complex shapes, but as yet it is unclear how this categorization learning affects the representation of shape in visual cortex. Previous studies that have examined the effect of categorization learning on shape representation in the macaque inferior temporal (IT) cortex have produced diverse and conflicting results…

  18. Drenagem anômala de veia pulmonar inferior direita em veia cava inferior associada a apêndice hepático intracardíaco Anomalous drainage of the right inferior pulmonary vein into the inferior vena cava associated to intrathoracic hepatic appendix

    Directory of Open Access Journals (Sweden)

    Carlos R Moraes

    1988-08-01

    Full Text Available Descreve-se o caso de uma paciente de 61 anos de idade, com drenagem anômala de veia pulmonar inferior direita em veia cava inferior, associada a apêndice hepático intratorácico, herniado através de fenda no diafragma. A correção cirúrgica foi realizada por anastomose direta da veia anômala com o átrio esquerdo, pela redução do apêndice hepático para a cavidade abdominal e, finalmente, pelo fechamento do defeito diafragmático. O pós-operatório decorreu sem qualquer complicação. Os autores chamam a atenção para a raridade do caso.The authors present a case of a 61-year-old woman with anomalous drainage of the right inferior pulmonary vein into the inferior vena cava associated to an intrathoracic hepatic appendix herniated through a diaphragmatic defect. Surgical correction was obtained by direct anastomosis of the anomalous vein to the left atrium, reduction of the hepatic appendix to the abdominal cavity and closure of the diphragmatic defect. The postoperative course was unevenftul. The rarity of this condition is stressed.

  19. Inferior Frontal Gyrus Activity Triggers Anterior Insula Response to Emotional Facial Expressions

    NARCIS (Netherlands)

    Jabbi, Mbemba; Keysers, Christian

    2008-01-01

    The observation of movies of facial expressions of others has been shown to recruit similar areas involved in experiencing one's own emotions: the inferior frontal gyrus (IFG). the anterior insula and adjacent frontal operculum (IFO). The Causal link bet between activity in these 2 regions, associat

  20. Radiographic abnormalities of the inferior pole of the patella in juvenile athletes

    International Nuclear Information System (INIS)

    We examined radiographs of the inferior pole of the patella in seven juvenile athletes diagnosed as having Sinding-Larsen-Johansson disease (SLJD) and discussed the etiology of the syndrome. Eight knees had tenderness at the inferior pole of the patella accompanied by radiographic abnormalities. A regular or irregular calcification was found at the inferior pole of the patella in three knees; coalescence of the calcification was found in two knees; incorporation of the calcification into the patella to yield a normal radiographic configuration of the area was found in two knees; and a small calcification separated from the patella was found in one knee. All of these findings varied and did not always correspond to the radiographic stages of the disease process identified by Medlar. One case was not clearly distinguished from either osteochondritis or stress fracture, and one case had a similar symptom to tendinitis. Thus, the etiology of the syndrome seems not to be unified, and the differential diagnosis between SLJD and osteochondritis, stress fracture, or tendinitis was difficult to arrive at. We were only able to conclude that the radiographic abnormalities and consequently the etiology of the syndrome vary, and therefore there is a limitation to call the syndrome accompanied by abnormal findings of the inferior pole of the patella under the umbrella term of SLJD. (author)

  1. Inferior alveolar nerve injury with laryngeal mask airway: a case report.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2011-01-01

    The incidence of damage to the individual cranial nerves and their branches associated with laryngeal mask airway use is low; there have been case reports of damage to the lingual nerve, hypoglossal nerve and recurrent laryngeal nerve. To the best of our knowledge we present the first reported case of inferior alveolar nerve injury associated with laryngeal mask airway use.

  2. Inferior alveolar nerve injuries associated with mandibular fractures at risk: a two-center retrospective study

    NARCIS (Netherlands)

    P. Boffano; F. Roccia; C. Galessio; K. Karagozoglu; T. Forouzanfar

    2014-01-01

    The aim of the study was to investigate the incidence of the inferior alveolar nerve (IAN) injury in mandibular fractures. This study is based on two databases that have continuously recorded patients hospitalized with maxillofacial fractures in two departments—Department of Maxillofacial Surgery, V

  3. Inferior Alveolar Nerve Injury after Mandibular Third Molar Extraction: a Literature Review

    Directory of Open Access Journals (Sweden)

    Rafael Sarikov

    2014-12-01

    Full Text Available Objectives: The purpose of this study was to systematically review the comprehensive overview of literature data about injury to the inferior alveolar nerve after lower third molar extraction to discover the prevalence of injury, the risk factors, recovery rates, and alternative methods of treatment. Material and Methods: Literature was selected through a search of PubMed electronic databases. Articles from January 2009 to June 2014 were searched. English language articles with a minimum of 6 months patient follow-up and injury analysis by patient’s reporting, radiographic, and neurosensory testing were selected. Results: In total, 84 literature sources were reviewed, and 14 of the most relevant articles that are suitable to the criteria were selected. Articles were analyzed on men and women. The influence of lower third molar extraction (especially impacted on the inferior alveolar nerve was clearly seen. Conclusions: The incidence of injury to the inferior alveolar nerve after lower third molar extraction was about 0.35 - 8.4%. The injury of the inferior alveolar nerve can be predicted by various radiological signs. There are few risk factors that may increase the risk of injury to the nerve such as patients over the age of 24 years old, with horizontal impactions, and extraction by trainee surgeons. Recovery is preferable and permanent injury is very rare.

  4. A case of emotional facial palsy with ipsilateral anterior inferior cerebellar artery territory infarction.

    Directory of Open Access Journals (Sweden)

    Khurana D

    2002-01-01

    Full Text Available Emotional facial palsy (EFP commonly results from anterolateral thalamic or striatocapsular infarcts. Its occurrence in brainstem lesions is uncommon, with previously reported cases being restricted to superior cerebellar artery infarction (3 cases. We report an unusual case of EFP ipsilateral to an anterior inferior cerebellar artery infarction, which opens new insights into the facial corticobulbar tract pathway.

  5. Aberrant network integrity of the inferior frontal cortex in women with anorexia nervosa

    Directory of Open Access Journals (Sweden)

    Stephanie Kullmann

    2014-01-01

    These results suggest that AN patients have reduced connectivity within the cognitive control system of the brain and increased connectivity within regions important for salience processing. Due to its fundamental role in inhibitory behavior, including motor response, altered integrity of the inferior frontal cortex could contribute to hyperactivity in AN.

  6. Sex segregation and equality in a multicultural society: inferiority as a standard for legal acceptability

    NARCIS (Netherlands)

    Brink, Marjolein van den; Loenen, T.; Tigchelaar, Jet

    2010-01-01

    This contribution explores the legal acceptability of old and new forms of sex segregation, using a multilayered ‘inferiority test’ that can be regarded as a specification of (inter)national equality and non-discrimination standards. The test is applied to a number of topical cases of sex segregatio

  7. Diffusion tensor imaging of the inferior colliculus and brainstem auditory-evoked potentials in preterm infants

    International Nuclear Information System (INIS)

    Preterm and low-birth-weight infants have an increased risk of sensorineural hearing loss. Brainstem auditory-evoked potentials (BAEP) are an effective method to detect subtle deficits in impulse conduction in the auditory pathway. Abnormalities on diffusion tensor imaging (DTI) have been shown to be associated with perinatal white-matter injury and reduced fractional anisotropy (FA) has been reported in patients with sensorineural hearing loss. To evaluate the possibility of a correlation between BAEP and DTI of the inferior colliculus in preterm infants. DTI at term age and BAEP measurements were performed on all very-low-birth-weight or very preterm study infants (n=56). FA and apparent diffusion coefficient (ADC) of the inferior colliculus were measured from the DTI. Shorter BAEP wave I, III, and V latencies and I-III and I-V intervals and higher wave V amplitude correlated with higher FA of the inferior colliculus. The association between the DTI findings of the inferior colliculus and BAEP responses suggests that DTI can be used to assess the integrity of the auditory pathway in preterm infants. (orig.)

  8. Mechanisms contributing to cluster formation in the inferior olivary nucleus in brainstem slices from postnatal mice

    DEFF Research Database (Denmark)

    Kølvraa, Mathias; Müller, Felix C; Jahnsen, Henrik;

    2014-01-01

    The inferior olivary nucleus (IO) in in vitro slices from postnatal mice (P5.5-P15.5) spontaneously generates clusters of neurons with synchronous calcium transients, and intracellular recordings from IO neurons suggest that electrical coupling between neighbouring IO neurons may serve as a...

  9. Case report: Conservative management of an arteriovenous fistula of the inferior epigastric artery.

    Science.gov (United States)

    Piñero, A; Reus, M; Agea, B; Capel, A; Riquelme, J; Parrilla, P

    2003-02-01

    We present a case of pseudoaneurysm and arteriovenous fistula of the inferior epigastric artery secondary to the placement of a drain during a surgical intervention. We stress the utility of colour Doppler ultrasound and arteriography embolisation in diagnosis and treatment, respectively. PMID:12642284

  10. Typology of abdominal arteries, with special reference to inferior phrenic arteries and their esophageal branches.

    Science.gov (United States)

    Piao, D X; Ohtsuka, A; Murakami, T

    1998-08-01

    Origins and distribution of the human inferior phrenic arteries were studied by dissecting 68 Japanese adult cadavers. The inferior phrenic arteries were usually observed as paired (left and right) vessels. Their origins were summarized as follows: a) the aorta itself (85/138 cases, 61.6%), b) the ventro-visceral arteries (celiaco-mesenteric system of the aorta) including the celiac trunk (39/138 cases, 28.2%) and the left gastric artery (4/138 cases, 2.9%), and c) the latero-visceral arteries (adreno-renal system of the aorta) including the middle adrenal artery (4/138 cases, 2.9%) and the renal artery (6/138 cases, 4.3%). The left and right arteries occasionally originated in common trunk from the aorta, celiaco-mesenteric system or adreno-renal system (22/138 cases, 15.9%). A typological diagram explaining these variations is given. The inferior phrenic arteries, especially the left ones, sometimes issued visceral or esophageal branches. This fact indicates that the inferior phrenic arteries are homologous with the celiac trunk and mesenteric arteries. It is further discussed that the celiac trunk and mesenteric arteries are originally paired vessels, through introduction of our previous typological diagram of the abdominal arteries. PMID:9781269

  11. Arrhythmia and conduction disorders in acute inferior myocardial infarction with right ventricular involvement

    International Nuclear Information System (INIS)

    To assess the prognostic impact of Right Ventricular (RV) myocardial involvement in patients with inferior MI. One hundred seventy patients who were admitted to cardiac care unit of Madani Heart Hospital, Tabriz, Iran with the diagnosis of inferior MI with (group 1) or without (group 2) simultaneous involvement of RV were studied from 2005 to 2006. Patients presenting within 12 hours of symptom onset were eligible for inclusion. Those with simultaneous Anterior wall MI, patients undergoing primary percutaneous transluminal coronary angioplasty and those with renal impairment (creatinine >2 mg/dl) were excluded. Eighty eight percent of the patients with RVMI and 75% with isolated inferior MI had some type of arrhythmia. AV block occurred in 42% of the infarctions with RV involvement and only in 29% of the control group. Intra ventricular conduction disturbance (IVCD) also were more frequent in RVMI (29.4% VS 13.1%, p=0.021), especially the RBBB (20% VS 7.4%, P=0.003). Ventricular fibrillation (VF) was observed in 5.2% and 1.2% and ventricular tachycardia in 26% and 12.2% respectively. In 27% of patients with RVMI it was necessary to implant a pacemaker as compared to 10% in control group. Mortality was higher in the patients with inferior infarction extended to the RV (15.3% vs 3.5%., P=0.0001). There was not a meaningful difference in incidence of LBBB between group 1 and 2 (3.1% vs 2.9% P=0.9). Patients with inferior MI who also have RV myocardial involvement are at increased risk of death and arrhythmias. (author)

  12. Clinical implications of anterior S-T segment depression in patients with acute inferior myocardial infarction

    International Nuclear Information System (INIS)

    To assess various factors associated with anterior S-T segment depression during acute inferior myocardial infarction, 47 consecutive patients with electrocardiographic evidence of a first transmural inferior infarction were studied prospectively with radionuclide ventriculography an average of 7.3 hours (range 2.9 to 15.3) after the onset of symptoms. Thirty-nine patients (Group I) had anterior S-T depression in the initial electrocardiogram and 8 (Group II) did not have such reciprocal changes. There was no difference between the two groups in left ventricular end-diastolic or end-diastolic volume index or left ventricular ejection fraction. Stroke volume index was greater in Group I than in Group II. There were no group differences in left ventricular total or regional wall motion scores. A weak correlation existed between the quantities (mV) or inferior S-T segment elevation and reciprocal S-T depression. No relation between anterior S-T segment depression and the left ventricular end-diastolic volume index could be demonstrated; the extent of left ventricular apical and right ventricular wall motion abnormalities, both frequently associated with inferior infarction, did not correlate with the quantity of anterior S-T depression. These data show that anterior S-T segment depression occurs commonly during the early evolution of transmural inferior infarction, is not generally a marker of functionally significant anterior ischemia and cannot be used to predict left ventricular function in individual patients. Anterior S-T segment depression may be determined by reciprocal mechanisms

  13. Primary percutaneous coronary intervention ameliorates complete atrioventricular block complicating acute inferior myocardial infarction

    Directory of Open Access Journals (Sweden)

    Lee SN

    2014-11-01

    Full Text Available Su Nam Lee, You-Mi Hwang, Gee-Hee Kim, Ji-Hoon Kim, Ki-Dong Yoo, Chul-Min Kim, Keon-Woong MoonDepartment of Internal Medicine, St Vincent’s Hospital, The Catholic University of Korea, Suwon, South KoreaObjective: Complete atrioventricular block (CAVB in acute inferior ST-segment elevation myocardial infarction (STEMI is associated with poor clinical outcomes after noninvasive treatment. This study was designed to determine the effect of primary percutaneous coronary intervention (PCI in patients with CAVB complicating acute inferior STEMI, at a single center.Methods: We enrolled 138 consecutive patients diagnosed with STEMI involving the inferior wall; of these, 27 patients had CAVB. All patients received primary PCI. The clinical characteristics, procedural data, and clinical outcomes were compared in patients with versus without CAVB. Results: Baseline clinical characteristics were similar between patients with and without CAVB. Patients with CAVB were more likely to present with cardiogenic shock, and CAVB was caused primarily by right coronary artery occlusion. Door-to-balloon time was similar between those two groups. After primary PCI, CAVB was reversed in all patients. The peak creatinine phosphokinase level, left ventricular ejection fraction and in-hospital mortality rate were similar between the two groups. After a median follow up of 318 days, major adverse cardiac events did not differ between the groups (8.1% in patients without CAVB; 11.1% in patients with CAVB (P=0.702.Conclusion: We conclude that primary PCI can ameliorate CAVB-complicated acute inferior STEMI, with an acceptable rate of major adverse cardiac events, and suggest that primary PCI should be the preferred reperfusion therapy in patients with CAVB complicating acute inferior myocardial infarction. Keywords: major adverse cardiac events, PCI-capable hospital

  14. On the Specificity of Interaction between the Saccharomyces cerevisiae Clamp Loader Replication Factor C and Primed DNA Templates during DNA Replication*

    OpenAIRE

    Hingorani, Manju M.; Coman, Maria Magdalena

    2002-01-01

    Replication factor C (RFC) catalyzes assembly of circular proliferating cell nuclear antigen clamps around primed DNA, enabling processive synthesis by DNA polymerase during DNA replication and repair. In order to perform this function efficiently, RFC must rapidly recognize primed DNA as the substrate for clamp assembly, particularly during lagging strand synthesis. Earlier reports as well as quantitative DNA binding experiments from this study indicate, however, that RFC interacts with prim...

  15. MATLAB implementation of a dynamic clamp with bandwidth of >125 kHz capable of generating I Na at 37 °C.

    Science.gov (United States)

    Clausen, Chris; Valiunas, Virginijus; Brink, Peter R; Cohen, Ira S

    2013-04-01

    We describe the construction of a dynamic clamp with a bandwidth of >125 kHz that utilizes a high-performance, yet low-cost, standard home/office PC interfaced with a high-speed (16 bit) data acquisition module. High bandwidth is achieved by exploiting recently available software advances (code-generation technology and optimized real-time kernel). Dynamic-clamp programs are constructed using Simulink, a visual programming language. Blocks for computation of membrane currents are written in the high-level MATLAB language; no programming in C is required. The instrument can be used in single- or dual-cell configurations, with the capability to modify programs while experiments are in progress. We describe an algorithm for computing the fast transient Na(+) current (I Na) in real time and test its accuracy and stability using rate constants appropriate for 37 °C. We then construct a program capable of supplying three currents to a cell preparation: I Na, the hyperpolarizing-activated inward pacemaker current (I f) and an inward-rectifier K(+) current (I K1). The program corrects for the IR drop due to electrode current flow and also records all voltages and currents. We tested this program on dual patch-clamped HEK293 cells where the dynamic clamp controls a current-clamp amplifier and a voltage-clamp amplifier controls membrane potential, and current-clamped HEK293 cells where the dynamic clamp produces spontaneous pacing behavior exhibiting Na(+) spikes in otherwise passive cells. PMID:23224681

  16. Evaluation of Early and Late Term Outcomes of Radiofrequency Surgery in the Treatment of Inferior Turbinate Hypertrophy

    Directory of Open Access Journals (Sweden)

    Murat Salihoglu

    2014-02-01

    Conclusion: Inferior turbinate RFA can be used alone effectively in the treatment of nasal obstruction caused by ITH. Results of inferior turbinate RFA are satisfactory for at least one year without causing impairment in physiologic mucociliary activity or other adverse effects. [Arch Clin Exp Surg 2014; 3(1.000: 34-39

  17. Cambios en el colículo inferior de la rata tras ablación cortical auditiva unilateral

    OpenAIRE

    Lamas Álvarez, Verónica

    2009-01-01

    [ES]El presente trabajo trata sobre los cambios en el colículo inferior de la rata tras ablación cortical auditiva unilateral. [En]This paper deals with changes in the inferior colliculus of the rat after unilateral auditory cortex ablation. Trabajo de Fin de Máster del Máster en Neurociencias, curso 2008-2009.

  18. Hombre de 75 años con edemas y sangrado digestivo inferior A 75 years old man with edema and inferior gastrointestinal bleeding

    Directory of Open Access Journals (Sweden)

    Alberto Carlos Reino Buelvas

    2004-02-01

    Full Text Available Se presenta el caso de un hombre de 75 años, quien consultó por edemas generalizados originados en un síndrome nefrótico, secundario a una glomerulopatía clasificada como de cambios mínimos. Se le iniciaron esteroides con mejoría de su proteinuria, pero al disminuir las dosis de éstos, recayó, por lo que requirió nueva hospitalización en la que se le documentaron trombosis venosa profunda y sangrado por tracto gastrointestinal inferior. Se le implantó un filtro de vena cava inferior y se le practicó una colonoscopia, en la que se encontró poliposis coli. Al estudio histológico se reportó un linfoma no Hodgkin compatible con un linfoma del manto (poliposis linfomatoide versus linfoma marginal tipo MALT de bajo grado. The case of a 75 year old man is presented. He consulted because of generalized edema and the diagnosis of nephrotic syndrome was done. Histologic study of a renal biopsy reported a glomerulopathy of minimal changes. Treatment with steroids improved of proteinuria, but on reducing the doses, proteinuria returned. In a second hospitalization deep venous thrombosis and gastrointestinal bleeding were diagnosed. A cava vein filter was implanted, colonoscopy was performed and Polyposis Coli was found. A non Hodgkin lymphoma compatible with MANTLE CELL lymphoma (lymphomatous polyposis vs MALT lymphoma was reported in the colonic biopsy.

  19. Two unique ligand-binding clamps of Rhizopus oryzae starch binding domain for helical structure disruption of amylose.

    Directory of Open Access Journals (Sweden)

    Ting-Ying Jiang

    Full Text Available The N-terminal starch binding domain of Rhizopus oryzae glucoamylase (RoSBD has a high binding affinity for raw starch. RoSBD has two ligand-binding sites, each containing a ligand-binding clamp: a polyN clamp residing near binding site I is unique in that it is expressed in only three members of carbohydrate binding module family 21 (CBM21 members, and a Y32/F58 clamp located at binding site II is conserved in several CBMs. Here we characterized different roles of these sites in the binding of insoluble and soluble starches using an amylose-iodine complex assay, atomic force microscopy, isothermal titration calorimetry, site-directed mutagenesis, and structural bioinformatics. RoSBD induced the release of iodine from the amylose helical cavity and disrupted the helical structure of amylose type III, thereby significantly diminishing the thickness and length of the amylose type III fibrils. A point mutation in the critical ligand-binding residues of sites I and II, however, reduced both the binding affinity and amylose helix disruption. This is the first molecular model for structure disruption of the amylose helix by a non-hydrolytic CBM21 member. RoSBD apparently twists the helical amylose strands apart to expose more ligand surface for further SBD binding. Repeating the process triggers the relaxation and unwinding of amylose helices to generate thinner and shorter amylose fibrils, which are more susceptible to hydrolysis by glucoamylase. This model aids in understanding the natural roles of CBMs in protein-glycan interactions and contributes to potential molecular engineering of CBMs.

  20. ß-adrenergic regulation of ion transport in pancreatic ducts: Patch-clamp study of isolated rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I

    1998-01-01

    . METHODS: Small intralobular ducts were isolated from rat pancreas and studied in vitro by the whole-cell patch clamp technique. Cell membrane voltages and currents were indicators of cellular ion transport. In some ducts, intracellular Ca2+ activity was measured by fluorescence optical methods. RESULTS......: Unstimulated duct cells had a membrane voltage (Vm) of about -50 mV. Isoproterenol had a concentration-dependent effect on Vm; at 10(-7) mol/L, it depolarized Vm by 20-25 mV and the cell conductance increased by 100 nanosiemens. These effects were a result of opening of luminal Cl- channels. Phenylephrine had...