WorldWideScience

Sample records for clamp infrahepatic inferior

  1. Infrahepatic inferior vena cava agenesis with bilateral renal vein thrombosis.

    Science.gov (United States)

    Skeik, Nedaa; Wickstrom, Kelly K; Schumacher, Clark W; Sullivan, Timothy M

    2013-10-01

    Congenital anomalies of the inferior vena cava (IVC) are rare and are estimated to be present in 0.07-8.7% of the general population. IVC agenesis (IVCA) is found in approximately 5% of cases of unprovoked lower extremity deep vein thrombosis in patients Renal vein thrombosis (RVT) is an extremely rare and unusual presentation of IVCA. We report a unique case of a 23-year-old previously healthy man presenting with infrahepatic IVCA-induced bilateral RVT with azygos and hemiazygos continuation. To our knowledge, this is the third reported case in the literature of IVCA-induced RVT and the first to affect the bilateral renal veins in the absence of any other thrombogenic risk factors or any lower extremity venous complications. We also present a literature review of IVCA-induced vein thrombosis and highlight the lack of literature to manage this condition.

  2. 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

  3. Substance P-mediated membrane currents in voltage-clamped guinea pig inferior mesenteric ganglion cells.

    Science.gov (United States)

    Griffith, W H; Hills, J M; Brown, D A

    1988-01-01

    Responses to substance P (SP) and to hypogastric nerve stimulation were recorded from voltage-clamped guinea pig inferior mesenteric ganglion (IMG) neurons, and compared with those to muscarine. Muscarine produced a voltage-dependent inward current accompanied by a reduced input conductance and inhibition of IM a time- and voltage-dependent K+-current (Brown and Adams: Nature 283:673-676, 1980). SP also produced an inward current, accompanied by a fall in input conductance (20 out of 31 cells) or a rise in input conductance (7 out of 31 cells). The fall in input conductance was not accompanied by an inhibition of M-current (unlike frog ganglia: Adams et al.: British Journal of Pharmacology 79:330-333, 1983) or an inhibition of the inward rectifier current (unlike globus pallidus neurons: Stanfield et al.: Nature 315:498-501, 1985). Repetitive hypogastric nerve stimulation (10-20 Hz, 2-10 s) produced a slow inward postsynaptic current lasting 1-3 min, with decreases or increases of input conductance matching those produced by SP. The postsynaptic current did not show a consistent or reproducible change in amplitude on varying the holding potential between -90 and -25 mV. It is concluded that SP and hypogastric stimulation produce complex and variable changes in ionic conductance in IMG neurons.

  4. 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.

  5. 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

  6. 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 ...

  7. 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

  8. Photovoltaic panel clamp

    Science.gov (United States)

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

    2012-06-05

    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.

  9. 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

  10. Clamping characteristics study on different types of clamping unit

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zhiwei; Liu, Haichao; Xie, Pengcheng [College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing China 100029 (China); Yang, Weimin [College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing China 100029 (China); State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing China 100029 (China)

    2015-05-22

    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.

  11. 门静脉和下腔静脉阻断与开放后门静脉高压犬肺动脉和肺组织超微结构改变%Ultrastructural pathology observation of pulmonary artery and lung in a portal hypertension canine model after portal and inferior vena cave clamped and opened

    Institute of Scientific and Technical Information of China (English)

    池信锦; 黑子清; 金亦; 杨扬; 陈规划

    2009-01-01

    Objective To observe the ultrastructural pathological characteristics of pulmonary artery and lung in a portal hypertension canine model after portal and inferior vena cave clamped and opened and to preliminarily explore the mechanism of perioperative acute pulmonary hypertension and injury in liver transplantation for end-stage liver cirrhosis.Methods Eighteen canines were randomly divided into groups Ⅰ (negative control group),Ⅱ (control group) and Ⅲ (model group). Canines in the negative control group were only for collecting lung and pulmonary artery, and a partial ligation of portal vein were performed in the model group. Portal-cavity was clamped and opened after 12 weeks in groups Ⅱ and Ⅲ. Samples of lung and pulmonary artery were collected postoperatively for transmission electron microscope observation.Results Endothelial cell, alveolar epithelial cell type Ⅰ and alveolar epithelium type Ⅱ showed obvious pathology changes;alveolar septum developed fibrosis and collagen fiber proliferation;pulmonary capillary formed thrombosis, basal membrane thickened markedly. Pulmonary vascular endothelial cells were dramatically damaged and were shed in part;the gap between pulmonary artery endothelial cell and tunica media was widened and subendothelial edema and more collagen fiber were developed.Conclusions The ultrastructure of pulmonary artery and lung was obviously changed in a portal hypertension canine model. This may be the ultrastructural pathology basis for acute pulmonary hypertension and acute lung injury during the perioperation in liver transplantation.%目的 观察门静脉和下腔静脉阻断与开放后门静脉高压模型犬肺组织与肺动脉的超微结构改变. 方法 正常家犬18只,随机均分为阴性对照组(仅用于取肺组织和肺动脉标本)、对照组和门静脉高压模型组(采用部分结扎门静脉的方法 建立门静脉高压症犬的模型并饲养12周),进行门静脉、肝上和肝下下腔静脉

  12. Surgical management of renal cell carcinoma with inferior vena caval thrombus: A teaching hospital experience

    Directory of Open Access Journals (Sweden)

    Kulkarni Jagdeesh

    2007-01-01

    Full Text Available Purpose: To evaluate the outcome of patients of renal cell carcinoma (RCC with inferior vena caval (IVC thrombus treated by radical nephrectomy and IVC thrombectomy in terms of clinical and pathological factors and prognosis. Materials and Methods: Sixty-three consecutive patients of RCC with IVC thrombus who underwent radical nephrectomy with IVC thrombectomy between June 1993 and May 2003 were included in this retrospective analysis. Data was analyzed in terms of clinical factors, such as level of thrombus, and pathological factors, such as grade, local invasion and N status. Results: Tumor thrombus level was infrahepatic in 35 patients, retrohepatic in 20 and suprahepatic in 8, including 5 with right atrial thrombus. The immediate post-operative mortality was 3%, and the incidence of major post-operative complications was 34%, but most of them improved after conservative management except one who needed surgery for burst abdomen. The disease free survival (DFS was 48.5%, 50.6%, 66.6% and 40% for infrahepatic, retrohepatic, suprahepatic and intra-atrial tumors, respectively. Of the histological types, patients with clear cell tumors had the best prognosis; those with granular cell had the worst prognosis (DFS of 53.5% vs 33.3%, though statistically not significant. Grade-2 tumors had better prognosis than grade-4 tumors (DFS 66.6% vs 0%, P < 0.001. Sixty-eight percent of patients without perinephric fat invasion were free of disease as compared to 31% of those with perinephric fat invasion (P < 0.01. Further, N status showed DFS of 60.9% in patients with negative nodes and 30% in patients with positive nodes (P < 0.05. Conclusion: Though surgery for RCC with IVC thrombus has high morbidity, it can give good results in terms of prolonged DFS in expert hands. Regarding long-term survival, pathological factors, such as local stage and grade, are more important than clinical factors, such as level of thrombus.

  13. Energy harvesting under excitation of clamped-clamped beam

    Science.gov (United States)

    Batra, Ashok; Alomari, Almuatasim; Aggarwal, Mohan; Bandyopadhyay, Alak

    2016-04-01

    In this article, a piezoelectric energy harvesting has been developed experimentally and theoretically based on Euler- Bernoulli Theory. A PVDF piezoelectric thick film has attached along of clamped-clamped beam under sinusoidal base excitation of shaker. The results showed a good agreement between the experimental and simulation of suggested model. The voltage output frequency response function (FRF), current FRF, and output power has been studied under short and open circuit conditions at first vibration mode. The mode shape of the clamped-clamped beam for first three resonance frequency has been modeled and investigated using COMSOL Multiphysics and MATLAB.

  14. 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.

  15. Bilateral inferior turbinate osteoma

    Science.gov (United States)

    Sahemey, R.; Warfield, A.T.; Ahmed, S.

    2016-01-01

    Osteomas are the most common benign osteoclastic tumours of the paranasal sinuses. However, nasal cavity and turbinate osteomas are extremely rare. Only nine middle turbinate, three inferior turbinate and one inferior turbinate osteoma cases have been reported to date. The present case report describes the management and follow-up of symptomatic bilateral inferior turbinate osteoma. A 60-year-old female presented with symptoms of bilateral nasal obstruction and right-sided epiphora. Radiological investigation found hypertrophic bony changes involving both inferior turbinates. The patient was managed successfully by endoscopic inferior turbinectomies in order to achieve a patent airway, with no further recurrence of tumour after 3 months postoperatively. To the best of our knowledge, this is the first reported case of bilateral inferior turbinate osteoma. We describe a safe and minimally invasive method of tumour resection, which has a better cosmetic outcome compared with other approaches. PMID:27534890

  16. 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. ...

  17. 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

  18. 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.

  19. Multifrequency Excitation of a Clamped-Clamped Microbeam

    KAUST Repository

    Jaber, Nizar R.

    2016-01-20

    We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

  20. 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 ...

  1. Oxygen clamps in gold nanowires

    OpenAIRE

    Novaes, Frederico D.; da Silva, Antonio J. R.; da Silva, E. Z.; Fazzio, A.

    2005-01-01

    We investigate how the insertion of an oxygen atom in an atomically thin gold nanowire can affect its rupture. We find, using ab initio total energy density functional theory calculations, that O atoms when inserted in gold nanowires form not only stable but also very strong bonds, in such a way that they can extract atoms from a stable tip, serving in this way as a clamp that could be used to pull a string of gold atoms.

  2. 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.

  3. 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.

  4. Dynamics of Open DNA Sliding Clamps.

    Science.gov (United States)

    Oakley, Aaron J

    2016-01-01

    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. PMID:27148748

  5. Incarcerated inferior lumbar (Petit's) hernia.

    Science.gov (United States)

    Astarcioğlu, H; Sökmen, S; Atila, K; Karademir, S

    2003-09-01

    Petit's hernia is an uncommon abdominal wall defect in the inferior lumbar triangle. Colonic incarceration through the inferior lumbar triangle, which causes mechanical obstructive symptoms, necessitates particular diagnostic and management strategy. We present a rare case of inferior lumbar hernia, leading to mechanical bowel obstruction, successfully treated with prosthetic mesh reinforcement repair.

  6. 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.

  7. Isolated inferior mesenteric portal hypertension with giant inferior mesenteric vein and anomalous inferior mesenteric vein insertion

    Directory of Open Access Journals (Sweden)

    G Raghavendra Prasad

    2013-01-01

    Full Text Available Extrahepatic portal hypertension is not an uncommon disease in childhood, but isolated inferior mesenteric portal varices and lower gastrointestinal (GI bleed have not been reported till date. A 4-year-old girl presented with lower GI bleed. Surgical exploration revealed extrahepatic portal vein obstruction with giant inferior mesenteric vein and colonic varices. Inferior mesenteric vein was joining the superior mesenteric vein. The child was treated successfully with inferior mesenteric - inferior vena caval anastomosis. The child was relieved of GI bleed during the follow-up.

  8. 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.

  9. 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.

  10. Organ protection during aortic cross-clamping.

    Science.gov (United States)

    Yeung, Kak Khee; Groeneveld, Menno; Lu, Joyce Ja-Ning; van Diemen, Pepijn; Jongkind, Vincent; Wisselink, Willem

    2016-09-01

    Open surgical repair of an aortic aneurysm requires aortic cross-clamping, resulting in temporary ischemia of all organs and tissues supplied by the aorta distal to the clamp. Major complications of open aneurysm repair due to aortic cross-clamping include renal ischemia-reperfusion injury and postoperative colonic ischemia in case of supra- and infrarenal aortic aneurysm repair. Ischemia-reperfusion injury results in excessive production of reactive oxygen species and in oxidative stress, which can lead to multiple organ failure. Several perioperative protective strategies have been suggested to preserve renal function during aortic cross-clamping, such as pharmacotherapy and therapeutic hypothermia of the kidneys. In this chapter, we will briefly discuss the pathophysiology of ischemia-reperfusion injury and the preventative measures that can be taken to avoid abdominal organ injury. Finally, techniques to minimize the risk of complications during and after open aneurysm repair will be presented. PMID:27650341

  11. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H. R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Job; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    BACKGROUND: To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. METHODS: Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inl

  12. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H.R.; Pol, Robert A.; Hulsebos, Robin G.; Det, van Rob J.; Palen, van der Job; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    Background To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Methods Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inla

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. Multilevel-clamped multilevel converters (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago;

    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...... clamping scheme is the ML clamping cell, which is composed of a pair of dc sources associated with one single-pole/triple-throw type of switch arrangement. The number of series-connected ML-clamping cells will set the number of levels of the synthesized waveform. By depending on the MCU arrangements...

  18. Dynamics and Stability of Pinned-Clamped and Clamped-Pinned Cylindrical Shells Conveying Fluid

    Science.gov (United States)

    Misra, A. K.; Wong, S. S. T.; Païdoussis, M. P.

    2001-11-01

    The paper examines the dynamics and stability of fluid-conveying cylindrical shells having pinned-clamped or clamped-pinned boundary conditions, where ``pinned'' is an abbreviation for ``simply supported''. Flügge's equations are used to describe the shell motion, while the fluid-dynamic perturbation pressure is obtained utilizing the linearized potential flow theory. The solution is obtained using two methods - the travelling wave method and the Fourier-transform approach. The results obtained by both methods suggest that the negative damping of the clamped-pinned systems and positive damping of the pinned-clamped systems, observed by previous investigators for any arbitrarily small flow velocity, are simply numerical artefacts; this is reinforced by energy considerations, in which the work done by the fluid on the shell is shown to be zero. Hence, it is concluded that both systems are conservative.

  19. Single molecule study of a processivity clamp sliding on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  20. AN ACTIVE VALVE WITH A CLAMPED MEMBRANE

    DEFF Research Database (Denmark)

    2009-01-01

    An active valve for use e.g. in fluidic microsystems is provided, wherein the active valve comprises a membrane having at least one flow gate, arranged between a first and a second substantially rigid element. Adjusting means provides an adjustment of the clamping force on membrane arranged between...... the first and second substantially rigid element. Hereby the flow rate through the active valve can be continuously and precisely controlled....

  1. 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....

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. Optimization of a clamped plate silencer.

    Science.gov (United States)

    Wang, Chunqi; Han, Jun; Huang, Lixi

    2007-02-01

    A previous theoretical study [L. Huang, J. Acoust. Soc. Am. 119, 2628-2638 (2006)] shows that, in a duct, a simply supported plate covering a side-branch rigid cavity can function effectively as a wave reflector over a broad range of low to medium frequencies. In this study, analytical formulation is extended to the boundary condition of clamped plate, which is easier to implement in practice. The theoretical model is tested experimentally using balsawood, which has a very high stiffness to mass ratio. The spectral peaks and shapes of the measured TL are in agreement with those calculated theoretically, attempts are also made to account for the considerable sound absorption in the rig. Further numerical studies based on the validated model show that, for a uniform plate, the optimal stopband is narrower and the lower band limit is worse than that of the simply supported configuration. However, a wave reflector using nonuniform, clamped plates with thinner ends out-performs the simply supported configuration in every aspect. Analyses show that the improvement is attributed to the increased acoustic radiation efficiency over the bulk length of the nonuniform plate, which behaves more like a rigid plate.

  7. 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

  8. Agenesia of the vena cava inferior

    Energy Technology Data Exchange (ETDEWEB)

    Kullnig, P.; Lammer, J.; Ranner, G.; Pilger, E.

    1986-12-01

    A case of agenesia of 3 of the 4 segments of the vena cava inferior is presented. The embryogenesis of the v. cava inferior is discussed in so far as is relevant for the malformation in this case. Exact diagnosis and classification can be made via intravenous and intraarterial DSA and computed tomography.

  9. Bilateral inferior petrosal sinus sampling

    Science.gov (United States)

    Grossrubatscher, Erika; Dalino Ciaramella, Paolo; Boccardi, Edoardo

    2016-01-01

    Simultaneous bilateral inferior petrosal sinus sampling (BIPSS) plays a crucial role in the diagnostic work-up of Cushing’s syndrome. It is the most accurate procedure in the differential diagnosis of hypercortisolism of pituitary or ectopic origin, as compared with clinical, biochemical and imaging analyses, with a sensitivity and specificity of 88–100% and 67–100%, respectively. In the setting of hypercortisolemia, ACTH levels obtained from venous drainage of the pituitary are expected to be higher than the levels of peripheral blood, thus suggesting pituitary ACTH excess as the cause of hypercortisolism. Direct stimulation of the pituitary corticotroph with corticotrophin-releasing hormone enhances the sensitivity of the procedure. The procedure must be undertaken in the presence of hypercortisolemia, which suppresses both the basal and stimulated secretory activity of normal corticotrophic cells: ACTH measured in the sinus is, therefore, the result of the secretory activity of the tumor tissue. The poor accuracy in lateralization of BIPSS (positive predictive value of 50–70%) makes interpetrosal ACTH gradient alone not sufficient for the localization of the tumor. An accurate exploration of the gland is recommended if a tumor is not found in the predicted area. Despite the fact that BIPSS is an invasive procedure, the occurrence of adverse events is extremely rare, particularly if it is performed by experienced operators in referral centres. PMID:27352844

  10. Bilateral inferior petrosal sinus sampling.

    Science.gov (United States)

    Zampetti, Benedetta; Grossrubatscher, Erika; Dalino Ciaramella, Paolo; Boccardi, Edoardo; Loli, Paola

    2016-07-01

    Simultaneous bilateral inferior petrosal sinus sampling (BIPSS) plays a crucial role in the diagnostic work-up of Cushing's syndrome. It is the most accurate procedure in the differential diagnosis of hypercortisolism of pituitary or ectopic origin, as compared with clinical, biochemical and imaging analyses, with a sensitivity and specificity of 88-100% and 67-100%, respectively. In the setting of hypercortisolemia, ACTH levels obtained from venous drainage of the pituitary are expected to be higher than the levels of peripheral blood, thus suggesting pituitary ACTH excess as the cause of hypercortisolism. Direct stimulation of the pituitary corticotroph with corticotrophin-releasing hormone enhances the sensitivity of the procedure. The procedure must be undertaken in the presence of hypercortisolemia, which suppresses both the basal and stimulated secretory activity of normal corticotrophic cells: ACTH measured in the sinus is, therefore, the result of the secretory activity of the tumor tissue. The poor accuracy in lateralization of BIPSS (positive predictive value of 50-70%) makes interpetrosal ACTH gradient alone not sufficient for the localization of the tumor. An accurate exploration of the gland is recommended if a tumor is not found in the predicted area. Despite the fact that BIPSS is an invasive procedure, the occurrence of adverse events is extremely rare, particularly if it is performed by experienced operators in referral centres. PMID:27352844

  11. Bilateral inferior petrosal sinus sampling

    Directory of Open Access Journals (Sweden)

    Benedetta Zampetti

    2016-08-01

    Full Text Available Simultaneous bilateral inferior petrosal sinus sampling (BIPSS plays a crucial role in the diagnostic work-up of Cushing’s syndrome. It is the most accurate procedure in the differential diagnosis of hypercortisolism of pituitary or ectopic origin, as compared with clinical, biochemical and imaging analyses, with a sensitivity and specificity of 88–100% and 67–100%, respectively. In the setting of hypercortisolemia, ACTH levels obtained from venous drainage of the pituitary are expected to be higher than the levels of peripheral blood, thus suggesting pituitary ACTH excess as the cause of hypercortisolism. Direct stimulation of the pituitary corticotroph with corticotrophin-releasing hormone enhances the sensitivity of the procedure. The procedure must be undertaken in the presence of hypercortisolemia, which suppresses both the basal and stimulated secretory activity of normal corticotrophic cells: ACTH measured in the sinus is, therefore, the result of the secretory activity of the tumor tissue. The poor accuracy in lateralization of BIPSS (positive predictive value of 50–70% makes interpetrosal ACTH gradient alone not sufficient for the localization of the tumor. An accurate exploration of the gland is recommended if a tumor is not found in the predicted area. Despite the fact that BIPSS is an invasive procedure, the occurrence of adverse events is extremely rare, particularly if it is performed by experienced operators in referral centres.

  12. 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

  13. 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

    2016-01-01

    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

  14. 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

  15. 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...

  16. 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 du...

  17. 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.

  18. Cell-Detection Technique for Automated Patch Clamping

    Science.gov (United States)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

  19. 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...

  20. A clamp-like biohybrid catalyst for DNA oxidation

    Science.gov (United States)

    van Dongen, Stijn F. M.; Clerx, Joost; Nørgaard, Kasper; Bloemberg, Tom G.; Cornelissen, Jeroen J. L. M.; Trakselis, Michael A.; Nelson, Scott W.; Benkovic, Stephen J.; Rowan, Alan E.; Nolte, Roeland J. M.

    2013-11-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric) template. In the case of the bacteriophage T4 replisome, a dedicated clamp protein acts as a processivity mediator by encircling DNA and subsequently recruiting its polymerase. Here we use this DNA-binding protein to construct a biohybrid catalyst. Conjugation of the clamp protein to a chemical catalyst with sequence-specific oxidation behaviour formed a catalytic clamp that can be loaded onto a DNA plasmid. The catalytic activity of the biohybrid catalyst was visualized using a procedure based on an atomic force microscopy method that detects and spatially locates oxidized sites in DNA. Varying the experimental conditions enabled switching between processive and distributive catalysis and influencing the sliding direction of this rotaxane-like catalyst.

  1. 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.

  2. 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.

  3. 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...

  4. Clinical studies on inferior right hepatic veins

    Institute of Scientific and Technical Information of China (English)

    Xue Xing; Hong Li; Wei-Guo Liu

    2007-01-01

    BACKGROUND:Many small veins are called accessory, short hepatic veins in addition to the right, middle and left hepatic veins. The size of these veins varied from a pinhole to 1 cm; the size of inferior right hepatic veins (IRHVs) is thicker than that of short hepatic veins or more than 1 cm occasionally. Adults have a higher incidence rate of the IRHV. DATA SOURCES:A literature search of the PubMed database was conducted and research articles were reviewed. RESULTS:The size of IRHVs is related to the size of the right hepatic vein, i.e. the larger the diameter of the right hepatic vein, the smaller the diameter of the IRHVs, and vice versa. The IRHVs are divided into superior, medial and inferior groups, separately named the superior, medial and inferior right hepatic veins according to the position of the IRHV entering the inferior vena cava. The superior right hepatic vein mainly drains the superior part of segmentⅦ, and the medial right hepatic vein drains the middle part of segmentⅦ. A thicker IRHV mainly drains segmentⅥ and the inferior part of segmentⅦ and a thinner IRHV drains the inferior part of segmentⅤ. CONCLUSIONS:The clinical signiifcance of these studies on IRHVs is varied: (1) Hepatic caudate lobe resection could be introduced after study on the veins of that lobe. (2) It is very important to identify the draining region of the IRHV for guiding hepatic segmentectomy. The postero-inferior area of the right lobe can be preserved along with the hypertrophic IRHV even if the entire main right hepatic vein is resected during segmentectomy ofⅦ andⅧwith right hepatic vein resection for patients with primary liver cancer. (3) The ligation of the major hepatic vein for the treatment of juxtahepatic vein injury is recommended because of severe hemorrhagic shock and dififculty in

  5. 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.

  6. Functional organization of the left inferior precentral sulcus: dissociating the inferior frontal eye field and the inferior frontal junction.

    Science.gov (United States)

    Derrfuss, J; Vogt, V L; Fiebach, C J; von Cramon, D Y; Tittgemeyer, M

    2012-02-15

    Two eye fields have been described in the human lateral frontal cortex: the frontal eye field (FEF) and the inferior frontal eye field (iFEF). The FEF has been extensively studied and has been found to lie at the ventral part of the superior precentral sulcus. Much less research, however, has focused on the iFEF. Recently, it was suggested that the iFEF is located at the dorsal part of the inferior precentral sulcus. A similar location was proposed for the inferior frontal junction area (IFJ), an area thought to be involved in cognitive control processes. The present study used fMRI to clarify the topographical and functional relationship of the iFEF and the IFJ in the left hemispheres of individual participants. The results show that both the iFEF and the IFJ are indeed located at the dorsal part of the inferior precentral sulcus. Nevertheless, the activations were spatially dissociable in every individual examined. The IFJ was located more towards the depth of the inferior precentral sulcus, close to the junction with the inferior frontal sulcus, whereas the iFEF assumed a more lateral, posterior and superior position. Furthermore, the results provided evidence for a functional double dissociation: the iFEF was activated only in a comparison of saccades vs. button presses, but not in a comparison of incongruent vs. congruent Stroop conditions, while the opposite pattern was found at the IFJ. These results provide evidence for a spatial and functional dissociation of two directly adjacent areas in the left posterior frontal lobe.

  7. Lateralization Technique and Inferior Alveolar Nerve Transposition

    Directory of Open Access Journals (Sweden)

    Angélica Castro Pimentel

    2016-01-01

    Full Text Available 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.

  8. 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

  9. 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

  10. 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.

  11. Portal Decompression Using the Inferior Mesenteric Vein

    Directory of Open Access Journals (Sweden)

    Paolo Gorini

    1998-01-01

    Full Text Available We report five patients with variceal hemorrhage, in three cases secondary to diffuse thrombosis of the portal, superior mesenteric and splenic veins. Mesenteric angiography demonstrated patency of the inferior mesenteric vein (IMV in each, and successful portal decompression by anastomosis of the IMV to the left renal vein (n=4 or the inferior vena cava (n=1 was accomplished. Bleeding was permanently controlled: four patients have survived from one to eight years post-operatively. Because shunt procedures utilizing the IMV are technically straightforward, subtotally decompress the portal system and avoid the right upper quadrant, they may be advantageous in certain clinical settings.

  12. Functional organization of the left inferior precentral sulcus: dissociating the inferior frontal eye field and the inferior frontal junction

    NARCIS (Netherlands)

    Derrfuss, J.; Vogt, V.L.; Fiebach, C.J.; Cramon, D.Y. von; Tittgemeyer, M.

    2012-01-01

    Two eye fields have been described in the human lateral frontal cortex: the frontal eye field (FEF) and the inferior frontal eye field (iFEF). The FEF has been extensively studied and has been found to lie at the ventral part of the superior precentral sulcus. Much less research, however, has focuse

  13. 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...

  14. 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...

  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. Hysteresis modeling of clamp band joint with macro-slip

    Science.gov (United States)

    Qin, Zhaoye; Cui, Delin; Yan, Shaoze; Chu, Fulei

    2016-01-01

    Clamp band joints are commonly used to connect spacecrafts with launch vehicles. Due to the frictional slippage between the joint components, hysteresis behavior might occur at joint interfaces under cyclic loading. The joint hysteresis will bring friction damping into the launching systems. In this paper, a closed-form hysteresis model for the clamp band joint is developed based on theoretical and numerical analyses of the interactions of the joint components. Then, the hysteresis model is applied to investigating the dynamic response of a payload fastened by the clamp band joint, where the nonlinearity and friction damping effects of the joint is evaluated. The proposed analytical model, which is validated by both finite element analyses and quasi-static experiments, has a simple form with sound accuracy and can be incorporated into the dynamic models of launching systems conveniently.

  17. Umbilical cord clamping. An analysis of a usual neonatological conduct.

    Science.gov (United States)

    Papagno, L

    1998-01-01

    Here we described a critical analysis of the neonatological procedure of early cord clamping, meaning this, within 40 seconds after birth. Fifty three cases are here analysed, in which this practice was not performed, but instead a late umbilical cord clamping was done after birth or after the cord had stopped beating. Variations in hematocrito values within 24 to 36 hours after birth were studied. A transitory polycithemia, with a maximum peak 12 hours post-delivery was observed. These values returned to normal levels between 24 and 36 hours after birth. K vitamin was not administered to any of the newborns. No pathology appeared related to this transitory polycithemia. In can be concluded that the late umbilical cord clamping represents no risk to the new-born and that the pathological phenomena described under these circumstances may be attributed to the increase in K vitamin dependent coagulation factors that are induced by the routinary administration of phitonadione to all normal newborns.

  18. 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...

  19. 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.

  20. 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)

  1. 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.

  2. [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

  3. 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.

  4. A piezoelectric vibration harvester based on clamped-guided beams

    NARCIS (Netherlands)

    Wang, Z.; Matova, S.; Elfrink, R.; Jambunathan, M.; Nooijer, C. de; Schaijk, R. van; Vullers, R.J.M.

    2012-01-01

    The paper addresses the design, modeling, fabrication and experimental results of a piezoelectric energy harvester based on clamped-guided beams. The design is featured by shorter mass displacement and higher reliability than cantilever beams. Two separate sets of capacitors allow exploiting both te

  5. 21 CFR 882.5175 - Carotid artery clamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable...

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

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ledwich, G.;

    2008-01-01

    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 poi...

  7. 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.

  8. 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...

  9. 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

  10. 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.

  11. Maxillary antral lavage using inferior meatal cannula anaesthesia.

    Science.gov (United States)

    Mochloulis, G; Hern, J D; Hollis, L J; Tolley, N S

    1996-08-01

    Antral puncture and lavage through the inferior meatus is a minor but common otolaryngological procedure, usually performed under local anaesthesia. We describe a new method of introducing local anaesthetic into the inferior meatus, via the use of a soft intravenous cannula connected to a syringe containing 10 per cent cocaine paste. We have called this new technique inferior meatal cannula anaesthesia (IMCA).

  12. 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

  13. 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

  14. 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

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

    NARCIS (Netherlands)

    Brouwer, D.M.; Jong, de B.R.; Boer, de M.J.; Jansen, H.V.; Dijk, van J.; Krijnen, G.J.M.; Soemers, H.M.J.R.

    2009-01-01

    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. s

  16. 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...

  17. 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...

  18. 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...

  19. 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 ...

  20. 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...

  1. Umbilical cord clamping. An analysis of a usual neonatological conduct.

    Science.gov (United States)

    Papagno, L

    1998-01-01

    Here we described a critical analysis of the neonatological procedure of early cord clamping, meaning this, within 40 seconds after birth. Fifty three cases are here analysed, in which this practice was not performed, but instead a late umbilical cord clamping was done after birth or after the cord had stopped beating. Variations in hematocrito values within 24 to 36 hours after birth were studied. A transitory polycithemia, with a maximum peak 12 hours post-delivery was observed. These values returned to normal levels between 24 and 36 hours after birth. K vitamin was not administered to any of the newborns. No pathology appeared related to this transitory polycithemia. In can be concluded that the late umbilical cord clamping represents no risk to the new-born and that the pathological phenomena described under these circumstances may be attributed to the increase in K vitamin dependent coagulation factors that are induced by the routinary administration of phitonadione to all normal newborns. PMID:9914812

  2. 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.

  3. 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...

  4. Total laparoscopic retrieval of inferior vena cava filter

    Directory of Open Access Journals (Sweden)

    Ehsan Benrashid

    2015-08-01

    Full Text Available While there is some local variability in the use of inferior vena cava filters and there has been some evolution in the indications for filter placement over time, inferior vena cava filters remain a standard option for pulmonary embolism prophylaxis. Indications are clear in certain subpopulations of patients, particularly those with deep venous thrombosis and absolute contraindications to anticoagulation. There are, however, a variety of reported inferior vena cava filter complications in the short and long term, making retrieval of the filter desirable in most cases. Here, we present the case of a morbidly obese patient complaining of chronic abdominal pain after inferior vena cava filter placement and malposition of the filter with extensive protrusion outside the inferior vena cava. She underwent successful laparoscopic retrieval of her malpositioned inferior vena cava filters after failure of a conventional endovascular approach.

  5. 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.

  6. Congenital anomalies of the inferior vena cava

    Energy Technology Data Exchange (ETDEWEB)

    Malaki, M., E-mail: mbmv@doctors.org.uk [Department of Clinical Radiology, Queen Elizabeth Hospital, Birmingham (United Kingdom); Willis, A.P.; Jones, R.G. [Department of Clinical Radiology, Queen Elizabeth Hospital, Birmingham (United Kingdom)

    2012-02-15

    Congenital anomalies of the inferior vena cava (IVC) and its tributaries are increasingly recognized in asymptomatic patients due to the more frequent use of cross-sectional imaging and computed tomography (CT) in particular. IVC development is a complex process involving formation of anastomoses between three pairs of embryonic veins in the 4th to 8th week of gestation. Various permutations occur in the basic venous plan of the abdomen and pelvis resulting in variants such as isolated left IVC, double IVC, and retroaortic left renal vein. The majority of these anomalies are asymptomatic but occasionally present clinically with thromboembolic complications. However, awareness of their existence is important to avoid important diagnostic pitfalls and in preoperative surgical and interventional radiological planning.

  7. 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.

  8. 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.

  9. Effect of Clamping Rigidity of the Armour on Ballistic Performance

    Directory of Open Access Journals (Sweden)

    S. N. Dikshit

    1992-04-01

    Full Text Available Influence of the manner in which the armour plates are held during their ballistic testing on the armour performance, has been evaluated. One armour plate was clamped rigidly to the test stand while a second plate of identical composition, hardness, and dimensions was hung loosely from the target holder. Both these plates were impacted with the same type of projectiles and over the same impact velocity range. The nature of ballistic damage evaluated indicates that the manner in which the armour is held during ballistic testing has a negligible influence on its performance at least when the mass of the plate is substantially higher than that of the projectile.

  10. 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....

  11. Patch-clamp detection of macromolecular translocation along nuclear pores

    Directory of Open Access Journals (Sweden)

    Bustamante J.O.

    1998-01-01

    Full Text Available The present paper reviews the application of patch-clamp principles to the detection and measurement of macromolecular translocation along the nuclear pores. We demonstrate that the tight-seal 'gigaseal' between the pipette tip and the nuclear membrane is possible in the presence of fully operational nuclear pores. We show that the ability to form a gigaseal in nucleus-attached configurations does not mean that only the activity of channels from the outer membrane of the nuclear envelope can be detected. Instead, we show that, in the presence of fully operational nuclear pores, it is likely that the large-conductance ion channel activity recorded derives from the nuclear pores. We conclude the technical section with the suggestion that the best way to demonstrate that the nuclear pores are responsible for ion channel activity is by showing with fluorescence microscopy the nuclear translocation of ions and small molecules and the exclusion of the same from the cisterna enclosed by the two membranes of the envelope. Since transcription factors and mRNAs, two major groups of nuclear macromolecules, use nuclear pores to enter and exit the nucleus and play essential roles in the control of gene activity and expression, this review should be useful to cell and molecular biologists interested in understanding how patch-clamp can be used to quantitate the translocation of such macromolecules into and out of the nucleus

  12. 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.

  13. 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.)

  14. 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.)

  15. 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...

  16. 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....

  17. Electrically integrated SU-8 clamped graphene drum resonators for strain engineering

    Science.gov (United States)

    Lee, Sunwoo; Chen, Changyao; Deshpande, Vikram V.; Lee, Gwan-Hyoung; Lee, Ilkyu; Lekas, Michael; Gondarenko, Alexander; Yu, Young-Jun; Shepard, Kenneth; Kim, Philip; Hone, James

    2013-04-01

    Graphene mechanical resonators are the ultimate two-dimensional nanoelectromechanical systems (NEMS) with applications in sensing and signal processing. While initial devices have shown promising results, an ideal graphene NEMS resonator should be strain engineered, clamped at the edge without trapping gas underneath, and electrically integratable. In this Letter, we demonstrate fabrication and direct electrical measurement of circular SU-8 polymer-clamped chemical vapor deposition graphene drum resonators. The clamping increases device yield and responsivity, while providing a cleaner resonance spectrum from eliminated edge modes. Furthermore, the clamping induces a large strain in the resonator, increasing its resonant frequency.

  18. Anticoagulation management during cross-clamping and bypass.

    Science.gov (United States)

    Lander, H; Zammert, M; FitzGerald, D

    2016-09-01

    Anticoagulation is required for successful implementation of cardiopulmonary bypass (CPB), as well as for surgeries requiring temporary aortic occlusion. It is well established that both coagulation and fibrinolysis are activated during CPB (Teufelsbauer et al., 1992) [1]. Appropriate dosing, monitoring, and maintenance of anticoagulation are essential to prevent devastating thrombosis of the CPB circuit or the occluded aorta and to minimize the activation of the hemostatic system. Although numerous novel anticoagulants have been developed over the past decade, unfractionated heparin remains the primary anticoagulant utilized during these types of procedures, with monitoring systems primarily based upon the activated clotting time and/or heparin concentration. This article will review the current state of anticoagulation management during cross-clamp and CPB. PMID:27650345

  19. 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...

  20. 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

  1. Implementing dynamic clamp with synaptic and artificial conductances in mouse retinal ganglion cells.

    Science.gov (United States)

    Huang, Jin Y; Stiefel, Klaus M; Protti, Dario A

    2013-05-16

    Ganglion cells are the output neurons of the retina and their activity reflects the integration of multiple synaptic inputs arising from specific neural circuits. Patch clamp techniques, in voltage clamp and current clamp configurations, are commonly used to study the physiological properties of neurons and to characterize their synaptic inputs. Although the application of these techniques is highly informative, they pose various limitations. For example, it is difficult to quantify how the precise interactions of excitatory and inhibitory inputs determine response output. To address this issue, we used a modified current clamp technique, dynamic clamp, also called conductance clamp (1, 2, 3) and examined the impact of excitatory and inhibitory synaptic inputs on neuronal excitability. This technique requires the injection of current into the cell and is dependent on the real-time feedback of its membrane potential at that time. The injected current is calculated from predetermined excitatory and inhibitory synaptic conductances, their reversal potentials and the cell's instantaneous membrane potential. Details on the experimental procedures, patch clamping cells to achieve a whole-cell configuration and employment of the dynamic clamp technique are illustrated in this video article. Here, we show the responses of mouse retinal ganglion cells to various conductance waveforms obtained from physiological experiments in control conditions or in the presence of drugs. Furthermore, we show the use of artificial excitatory and inhibitory conductances generated using alpha functions to investigate the responses of the cells.

  2. Effect of clamping pressure on the performance of a PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Chang, W.R. [Department of Landscape Architecture, Chung-Hua University, Hsinchu 300 (Taiwan); Hwang, J.J. [Department of Environment and Energy, National University of Tainan, Tainan 700 (Taiwan); Weng, F.B.; Chan, S.H. [Fuel Cell Center and Department of Mechanical Engineering, Yuan Ze University, Nei Li, Taoyuan 320 (Taiwan)

    2007-03-30

    Examined were the effects of the clamping pressure on the performance of a proton exchange membrane (PEM) fuel cell. The electro-physical properties of the gas diffusion layer (GDL) such as porosity, gas permeability, electrical resistance and thickness were measured using a special-designed test rig under various clamping pressure levels. Correlations for the gas permeability of the GDL were developed in terms of the clamping pressure. In addition, the contact resistance between the GDL and the bipolar (graphite) plate was measured under various clamping pressures. Results showed that at the low clamping pressure levels (e.g. <5 bar) increasing the clamping pressure reduces the interfacial resistance between the bipolar plate and the GDL that enhances the electrochemical performance of a PEM fuel cell. In contrast, at the high clamping pressure levels (e.g. >10 bar), increasing the clamping pressure not only reduces the above Ohmic resistance but also narrows down the diffusion path for mass transfer from gas channels to the catalyst layers. Comprising the above two effects did not promote the power density too much but reduce the mass-transfer limitation for high current density. (author)

  3. Structural insight into β-Clamp and its interaction with DNA Ligase in Helicobacter pylori.

    Science.gov (United States)

    Pandey, Preeti; Tarique, Khaja Faisal; Mazumder, Mohit; Rehman, Syed Arif Abdul; Kumari, Nilima; Gourinath, Samudrala

    2016-08-08

    Helicobacter pylori, a gram-negative and microaerophilic bacterium, is the major cause of chronic gastritis, gastric ulcers and gastric cancer. Owing to its central role, DNA replication machinery has emerged as a prime target for the development of antimicrobial drugs. Here, we report 2Å structure of β-clamp from H. pylori (Hpβ-clamp), which is one of the critical components of DNA polymerase III. Despite of similarity in the overall fold of eubacterial β-clamp structures, some distinct features in DNA interacting loops exists that have not been reported previously. The in silico prediction identified the potential binders of β-clamp such as alpha subunit of DNA pol III and DNA ligase with identification of β-clamp binding regions in them and validated by SPR studies. Hpβ-clamp interacts with DNA ligase in micromolar binding affinity. Moreover, we have successfully determined the co-crystal structure of β-clamp with peptide from DNA ligase (not reported earlier in prokaryotes) revealing the region from ligase that interacts with β-clamp.

  4. 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

    The attempt to combine the planar patch clamping idea with the microelectrode array (MEA) concept has led to the fabrication of a patch clamp micro-channel array (PC mu CA). Such a system is thought to be a powerful framework for neuroscience research and drug screening, as a novel tool for simul...

  5. Note: High-efficiency energy harvester using double-clamped piezoelectric beams

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon, E-mail: mems@jnu.ac.kr [MEMS and Nanotechnology Laboratory, School of Mechanical Systems Engineering, Chonnam National University, Gwangju (Korea, Republic of)

    2014-02-15

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  6. Note: high-efficiency energy harvester using double-clamped piezoelectric beams.

    Science.gov (United States)

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon

    2014-02-01

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  7. 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.

  8. 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...

  9. Note: high-efficiency energy harvester using double-clamped piezoelectric beams.

    Science.gov (United States)

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon

    2014-02-01

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g. PMID:24593401

  10. 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)

  11. 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

  12. 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

  13. 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.

  14. 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

    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 moiety...

  15. 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

  16. Inferior Flap Tympanoplasty: A Novel Technique for Anterior Perforation Closure

    Directory of Open Access Journals (Sweden)

    Haim Gavriel

    2013-01-01

    Full Text Available Objective. To report a novel tympanoplasty modification for anterior tympanic membrane perforation closure. Materials and Methods. A prospective study on 13 patients who underwent inferior tympanoplasty between December 2008 and May 2011 was carried out. In our technique, an inferior rather than a posterior flap is raised and the graft is laid from the inferior direction to obtain better access to the anterior part of the tympanic membrane perforation and provide better support. Results. A total of 13 patients underwent the novel inferior tympanoplasty technique with a mean age of 33 years. Six patients had undergone tympanoplasties and/or mastoidectomies in the past, 3 in the contralateral ear. A marginal perforation was observed in 3 cases, total perforation in 2 and subtotal in 1 case. The mean preoperative pure-tone average was 40.4 dB (10 to 90 dB, compared to 26.5 dB (10 to 55 dB postoperatively. All perforations were found to be closed but one (92.3% success rate. Conclusions. The inferior tympanoplasty technique provides a favorable outcome in terms of tympanic membrane closure and hearing improvement for anterior perforations, even in difficult and complex cases. It is based on a well-known technique and is easy to implement.

  17. Traumatic neuroma of the inferior alveolar nerve: a case report.

    Science.gov (United States)

    Arribas-García, Ignacio; Alcalá-Galiano, Andrea; Gutiérrez, Ramón; Montalvo-Moreno, Juan José

    2008-03-01

    Traumatic neuromas are rare entities which characteristically arise subsequently to surgery and are usually accompanied by pain, typically neuralgic. We present an unusual case of an intraosseous traumatic neuroma of the inferior alveolar nerve following tooth extraction. A 56-year-old man consulted for paresthesias and hyperesthesia in the left mandibular region following extraction of the left mandibular third molar (#38). The panoramic radiograph revealed a radiolucent lesion in the inferior alveolar nerve canal, and CT demonstrated the existence of a mass within the canal, producing widening of the same. Nerve-sparing excisional biopsy was performed. Histopathology and immunohistochemistry were consistent with traumatic neuroma of the left inferior alveolar nerve. After 3 years of follow-up, the patient is asymptomatic and there are no signs of recurrence.

  18. 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

  19. 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.

  20. Agenesia de veia cava inferior associada à trombose venosa profunda Agenesis of inferior vena cava associated with deep venous thrombosis

    Directory of Open Access Journals (Sweden)

    Clovis Luis Konopka

    2010-09-01

    Full Text Available A agenesia da veia cava inferior é uma anomalia congênita rara, que foi recentemente identificada como um importante fator de risco para o desenvolvimento e a recorrência de trombose venosa profunda de membros inferiores em jovens. O objetivo deste trabalho foi relatar o caso de uma paciente que apresentou trombose venosa profunda dois meses após a realização de cirurgia de varizes. A angiotomografia computadorizada demonstrou a presença de anomalia venosa complexa com ausência da veia cava inferior.The agenesis of the inferior vena cava is a rare congenital anomaly, which was recently identified as an important risk factor for the development and recurrence of deep venous thrombosis especially in young people. The goal of this work was to report the case of a patient who presented deep venous thrombosis approximately two months after varicose vein surgery. The computerized angiotomography demonstrated the presence of a complex venous anomaly with absence of the inferior vena cava.

  1. 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%.

  2. 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 ...

  3. 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.

  4. 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

  5. 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.

  6. Maksilektomi Inferior pada Karsinoma Sel Skuamosa Palatum Durum

    Directory of Open Access Journals (Sweden)

    Sukri Rahman

    2016-01-01

    Full Text Available Abstrak          Karsinoma Palatum Durum adalah keganasan daerah kepala dan leher yang jarang terjadi dimana setengah diantaranya merupakan Karsinoma Sel Skuamosa. Pada fase awal keganasan ini dapat bersifat asimptomatis namun dapat juga menimbulkan gejala berupa ulkus yang terasa nyeri pada perkembangan penyakitnya. Operasi maksilektomi inferior merupakan salah satu pilihan tindakan yang dapat dilakukan dalam tatalaksana kasus ini, diikuti oleh pemberian radioterapi. Kasus ini dibuat untuk memahami penatalaksanaan karsinoma palatum durum. Dilaporkan kasus seorang laki-laki 45 tahun dengan diagnosis Karsinoma Sel Skuamosa Palatum Durum (Well to Moderately Differentiated Keratinized stadium IVa (T4aN0M0 dilakukan operasi maksilektomi inferior, namun tidak diikuti dengan radioterapi karena pasien menolak. Maksilektomi inferior merupakan pilihan pembedahan pada tumor yang terbatas pada palatum, lantai sinus maksila dan kavum nasi. Prognosis karsinoma sel skuamosa palatum durum cukup baik dan angka harapan hidup lima tahun akan bertambah bila dilakukan operasi diikuti dengan pemberian radioterapi. Kata kunci: Karsinoma sel skuamosa, maksilektomi inferior, radioterapi AbstractCarcinoma of the hard palate is a rare head and neck cancer in which half of it was Squamous Cell Carcinoma. In the initial phase of this malignancy may be asymptomatic, but can also cause symptoms such as painful ulcers in the development of the disease. Inferior maxillectomy is one of the choice of operation that can be performed, followed by radiotherapy to understand the management of carcinoma of the hard palate. Reported one case of a man 45 years old with diagnosis Squamous Cell Carcinoma of hard palate (Well to Moderately Differentiated Keratinized stage IVa (T4aN0M0 treated by inferior maxillectomy surgery, but not followed by radiotherapy because the patient refused. Inferior Maksilektomi is a surgical option in tumor that limited to the palate, floor of the

  7. 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.

  8. Suprarenal symplastic leiomyoma of the inferior vena cava.

    Science.gov (United States)

    Kepenekci, Ilknur; Demirkan, Arda; Sözener, Ulas; Cakmak, Atil; Demirer, Seher; Alaçayir, Iskender; Ekinci, Cemil

    2009-01-01

    We report on a case of a leiomyoma in the inferior vena cava that appeared in the image to be located in the adrenal gland. En bloc excision of the tumor with the right adrenal gland and the involved segment of the vena cava was carried out. Histopathological work-up of the tumor revealed smooth muscle fibers and marked nuclear pleomorphism consistent with symplastic leiomyoma. This case report presents a distinct histological variant of the rarely seen primary smooth muscle tumor of the inferior vena cava.

  9. 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

  10. 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.

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

    Science.gov (United States)

    Das, Debasis; Krantz, Bryan A.

    2016-01-01

    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

  14. 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.

  15. 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

  16. 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.

  17. Introduction of a modular automated voltage-clamp platform and its correlation with manual human Ether-à-go-go related gene voltage-clamp data.

    Science.gov (United States)

    Scheel, Olaf; Himmel, Herbert; Rascher-Eggstein, Gesa; Knott, Thomas

    2011-12-01

    In investigating ion channel pharmacology, the manual patch clamp is still considered the gold standard for data quality, notwithstanding the major drawbacks of low throughput and the need for skilled operators. The automated patch clamp platform CytoPatch™ Instrument overcomes these restrictions. Its modular fully automated design makes it possible to obtain scalable throughput without the need for well-trained operators. Its chip design and perfusion system reproduces the manual patch technique, thus ensuring optimal data quality. Further, the use of stably transfected frozen cells, usable immediately after thawing, eliminates the cell quality impairment and low success rates associated with a running cell culture and renders screening costs accurately calculable. To demonstrate the applicability of this platform, 18 blinded compounds were assessed for their impact on the cardiac human Ether-à-go-go related gene K(+) channel. The IC(50) values obtained by the CytoPatch Instrument using the frozen human embryonic kidney 293 cells showed a high correlation (R(2)=0.928) with those obtained from manual patch clamp recordings with human embryonic kidney 293 cells from a running cell culture. Moreover, this correlation extended to sticky compounds such as terfenadine or astemizole. In conclusion, the CytoPatch Instrument operated with frozen cells ready to use directly after thawing provides the same high data quality known from the manual voltage clamp and has the added benefit of enhanced throughput for use in ion channel screening and safety assessment. PMID:21675869

  18. 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.

  19. INFERIOR VENA-CAVA OBSTRUCTION AFTER ORTHOTOPIC LIVER-TRANSPLANTATION

    NARCIS (Netherlands)

    BROUWERS, MAM; DEJONG, KP; PEETERS, PMJG; BIJLEVELD, CMA; KLOMPMAKER, IJ; SLOOFF, MJH

    1994-01-01

    Post-operative inferior vena cava (IVC) obstruction is reported as an uncommon complication after orthotopic liver transplantation (OLT). We report 6 cases after 245 OLT's in the period between March '79 and December '92. Compression or torsion of the IVC or a technical problem were underlying cause

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. Novel Low Loss Active Voltage Clamp Circuit for Series Connection of RCGCT thyristors

    Science.gov (United States)

    Ito, Hiroshi; Suzuki, Akihiro; Iwata, Akihiko

    This paper describes novel low loss active voltage clamp circuits for the series connection of RCGCT thyristors. For high voltage converters the series connection of power semiconductor devices is an essential technique for direct switching of high voltages. Several protection circuits have been applied to the series connection of RCGCT thyristors such as CRD snubber circuits which suppress over-voltages across RCGCT thyristors, and voltage balancing resistors to equalize voltage sharing in steady states. However, significant losses in these protection circuits lower the converter’s efficiency. We propose novel low-loss protection circuits, which have active voltage clamp snubber circuits and static voltage balancing circuits. The clamp capacitor voltage of the active voltage clamp snubber circuits are designed to be higher than the equally divided DC-Link voltage. This method can reduce the loss of the clamp circuit to no more than 1/10 of that of the conventional CRD snubber. Also the static voltage balancing circuits compensate for the voltage imbalance generated by the difference in the leakage current between the series connection RCGCT thyristors.

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

    Directory of Open Access Journals (Sweden)

    Can eTao

    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.

  7. PEMANFAATAN BIJI KAKAO INFERIOR CAMPURAN SEBAGAI SUMBER ANTIOKSIDAN DAN ANTIBAKTERI

    Directory of Open Access Journals (Sweden)

    Yulianto Tri Chandra Kusuma

    2013-11-01

    Full Text Available [ENGLISH] There are about 30% of cocoa beans still classified as inferior or low quality beans due to diseases. Low-quality cocoa beans can be used as the source of polyphenolic substances. The purpose of this study was to determine the potency of inferior cocoa beans with various particle sizes as raw materials for polyphenol extraction, and the use of polyphenol-rich cocoa extracts as antioxidant and antibacterial substances. The research was conducted in two stages, namely preliminary research and primary research. This preliminary study aimed to obtain polyphenol-rich cocoa bean extract and to examine antioxidant activity using DPPH method. The next research was to conduct antibacterial test against Escherichia coli and Bacillus subtilis using well diffusion method treated using polyphenols of each type of various particle size (16 mesh, 25 mesh, 35 mesh with concentrations of 0 ppm, 25.000 ppm, 50.000 ppm, 75.000 ppm, 100.000 ppm. The plates were incubated at 37°C for 24 hours and the inhibition power against bacteria was observed. The results showed that the greater the concentration of polyphenol extracts and the smaller size of the filter powder cocoa resulted in the increase of bacterial growth inhibition area. Keywords: Polyphenol; Cocoa beans; Escherichia coli; Bacillus subtilis [INDONESIAN] Biji kakao inferior merupakan biji buah kakao bermutu rendah karena terserang penyakit dan belum termanfaatkan secara maksimal. Biji kakao berkualitas rendah dapat dimanfaatkan dengan cara mengekstrak kandungan polifenolnya. Tujuan penelitian ini adalah mengetahui potensi ekstrak polifenol biji kakao inferior dengan variasi ukuran partikel sebagai bahan yang memiliki aktivitas antioksidan dan penghambat pertumbuhan bakteri. Penelitian ini dilakukan dalam dua tahap, yaitu penelitian pendahuluan dan penelitian utama. Penelitian pendahuluan bertujuan untuk memperoleh esktrak polifenol dari biji kakao inferior campuran yang terserang penyakit

  8. 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...... for the chip, because it influences contact electrical resistance, contact thermal resistance and power cycling capability. Ideally, the clamping force should be equally distributed among chips, in order to maximize the reliability of the PP IGBT. The model is built around a hypothetical PP IGBT with 9 chips......, and it has numerous simplifications in order to reduce the simulation time as much as possible. The developed model is used to analyze the clamping force distribution among chips, in various study cases, where uniform and non-uniform clamping pressures are applied on the studied PP IGBT....

  9. 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

  10. 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.

  11. Inferior turbinate osteoma as a cause of unilateral nose obstruction.

    Science.gov (United States)

    Grabovac, Stjepan; Hadzibegović, Ana Danić; Markesić, Josip

    2012-11-01

    Osteomas are benign, slow growing bone tumors often seen in paranasal sinuses, mostly in the frontal sinus, whereas they are rare in the nasal cavity. Inferior turbinate osteoma is extremely rare and our case is the third reported in the literature to date. Symptoms vary depending on the location, size and spreading and nasal obstruction is the most common symptom. Treatment of osteomas is surgical and is reserved only for rapidly growing osteomas with symptoms of infection or compression. Although endoscopic surgery is preferred modality, external approach with lateral rhinotomy should be considered with larger osteomas especially those that involve the ethmoid labyrinth. In cases like ours, when large osteoma is localized on the inferior nasal turbinate, sublabial incision through the vestibulum is very suitable approach because it provides wide access and good visibility and leaves no visible scar.

  12. 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.

  13. 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.

  14. 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

  15. Promoting physiologic transition at birth: re-examining resuscitation and the timing of cord clamping.

    Science.gov (United States)

    Niermeyer, Susan; Velaphi, Sithembiso

    2013-12-01

    Delayed clamping of the umbilical cord is recommended for term and preterm infants who do not require resuscitation. However, the approach to the newly born infant with signs of fetal compromise, prematurity and extremely low birthweight, or prolonged apnea is less clear. Human and experimental animal data show that delaying the clamping of the umbilical cord until after the onset of respirations promotes cardiovascular stability in the minutes immediately after birth. Rather than regarding delayed cord clamping as a fixed time period before resuscitation begins, a more physiologic concept of transition at birth should encompass the relative timing of onset of respirations and cord occlusion. Further research to explore the potential benefits of resuscitation with the cord intact is needed. PMID:24055300

  16. Minimum Normal Force Principle Based Quantitive Optimizationof Clamping Forces for Thin Walled Part

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fa-ping; SUN Hou-fang; SHAHID I.Butt

    2008-01-01

    Based on the stability criteria of workpiece-fixture system, quantitative optimization of clamping forces during precise machining process for thin walled part is studied considering the contact condition between wokpiece and locator, the contact mechanical model is achieved ,which is further been used to calculate the entire passive forces acting on the statically undetermined workpiece by means of the force screw theory as well as minimum norm force principle. Furthermore, a new methodology to optimize clamping forces is put forward, on the criteria of keeping the stability of workpiece during cutting process. By this way, the intensity of clamping forces is decreased dramatically, which will be most beneficial for improving the machining quality of thin-walled parts. Finally, a case study is used to support and validate the proposed model.

  17. FUNDAMENTAL RESONANCE AND BIFURCATION OF LARGE GENERATOR END WINDING WHEN ITS CLAMPING PLATES ARE LOOSE

    Institute of Scientific and Technical Information of China (English)

    HU Yu-da; QIU Jia-jun; TA Na

    2005-01-01

    Vibration problems of a segment of winding between two clamping plates are studied when the clamping plates, which are used to fix stator end winding, are loose. First,magnetic induction expressions of the winding while the generator was running were given by using separation of variables method. Also, the expressions of the winding electromagnetic force and dry friction force between loosing clamping plates were gotten. Secondly, a mechanical model, which was used to study nonlinear vibration problem of the winding, was set up. Fundamental resonance was analyzed by using multiple scales method, and a resonance equation of amplitude and frequency in steady state was given. Then stability,bifurcation and singularity of the steady solution were studied. Criterions of stability and transition set of the bifurcation equation were obtained. At last, through numerical calculations, resonance curves were obtained. The results are helpful for analysis and protection of generator accidents.

  18. 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...

  19. 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.

  20. 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.

  1. 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 ...

  2. [Aneurysm of the anterior inferior cerebellar artery: case report].

    Science.gov (United States)

    Adorno, Juan Oscar Alarcón; de Andrade, Guilherme Cabral

    2002-12-01

    The intracranial aneurysms of the posterior circulation have been reported between 5 and 10% of all cerebral aneurysms and the aneurysms of the anterior inferior cerebellar artery (AICA) are considered rare, can cause cerebello pontine angle (CPA) syndrome with or without subarachnoid hemorrhage. Since 1948 few cases were described in the literature. We report on a 33 year-old female patient with subarachnoid hemorrhage due to sacular aneurysm of the left AICA. She was submitted to clipage of the aneurysm without complications.

  3. 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.

  4. 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.

  5. Evidence of Mirror Neurons in Human Inferior Frontal Gyrus

    OpenAIRE

    Kilner, J. M.; Neal, A.; Weiskopf, N; Friston, K.J.; Frith, C. D.

    2009-01-01

    There is much current debate about the existence of mirror neurons in humans. To identify mirror neurons in the inferior frontal gyrus (IFG) of humans we employed a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging. Subjects either executed or observed a series of actions. Here we show that in the IFG, responses were suppressed both when an executed action was followed by the same rather than a different observed action and when an obse...

  6. 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.

  7. 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.

  8. Inferior hip dislocation after falling from height: A case report

    Science.gov (United States)

    Tekin, Ali Çağrı; Çabuk, Haluk; Büyükkurt, Cem Dinçay; Dedeoğlu, Süleyman Semih; İmren, Yunus; Gürbüz, Hakan

    2016-01-01

    Introduction Traumatic inferior hip dislocation is the least common of all hip dislocations. Adult inferior hip dislocations usually occur after high-energy trauma, very few cases are reported without fracture. Presentation of case A 26-year-old female was brought to the emergency department with severe pain in the left hip, impaired posture and restricted movement following a fall from 15 m height. The hip joint was fixed in 90° flexion, 15° abduction, and 20° external rotation. No neurovascular impairment was determined. On radiologic examination, a left ischial type inferior hip dislocation was detected. Hemorrhagic shock which developed due to acute blood loss to thoracic and abdominal cavity and patient died at third hour after she was brought to the hospital. Discussion Traumatic hip dislocations have high morbidity and mortality rates due to multiple organ damage, primarily of the extremities, chest and abdomen. In the treatment of traumatic hip dislocation, closed reduction is recommended through muscle relaxation under general anesthesia or sedation. This procedure should be applied before any intervention for concomitant extremity injuries. A detailed evaluation on emergency presentation, a multi-disciplinary approach and early diagnosis with the rapid application of imaging methods could be life-saving for such patients. PMID:27058153

  9. 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

  10. [Inferior vertical nystagmus: is magnetic resonance imaging mandatory?].

    Science.gov (United States)

    Esteban-Sánchez, Jonathan; Rueda-Marcos, Almudena; Sanz-Fernández, Ricardo; Martín-Sanz, Eduardo

    2016-02-01

    Introduccion. La aparicion de un nistagmo vertical inferior clasicamente obliga a descartar una patologia vascular o de la union craneocervical mediante resonancia magnetica (RM). Estudios recientes demuestran una baja rentabilidad de esta prueba, ya que sugieren que este signo oculomotor puede tener una causa vestibular periferica, sobre todo cuando el paciente presenta un vertigo posicional paroxistico benigno (VPPB) del canal semicircular superior. Objetivo. Comprobar la rentabilidad de la RM en una poblacion de pacientes con nistagmo de posicion vertical inferior. Pacientes y metodos. Estudio retrospectivo de 42 pacientes consecutivos a los que se les realizo una historia clinica, exploracion fisica, y pruebas vestibulares caloricas y rotatorias. A todos ellos se les practico una RM craneal y cervical. Resultados. El 52% de los pacientes con nistagmo de posicion vertical inferior presentaba una clinica y exploracion fisica compatibles con VPPB del canal semicircular superior. La RM fue normal en un 67%, un 26% mostraba datos de espondilopatia y un 5% de microangiopatia cerebral no relacionados con la clinica del paciente. La prevalencia de malformacion de Arnold-Chiari de tipo I fue de un 9% en la poblacion estudiada, sin que nadie tuviera un antecedente reciente de VPPB. Los resultados obtenidos en las pruebas complementarias vestibulares no aportaron informacion adicional para llegar a un diagnostico etiologico. Conclusion. En los pacientes con un VPPB, la RM craneal y las pruebas vestibulares tienen una baja rentabilidad diagnostica, y se debe evaluar la necesidad real de esta prueba con el contexto clinico.

  11. Cerebral oxygenation and processed EEG response to clamping and shunting during carotid endarterectomy under general anesthesia.

    Science.gov (United States)

    Perez, William; Dukatz, Christopher; El-Dalati, Sami; Duncan, James; Abdel-Rasoul, Mahmoud; Springer, Andrew; Go, Michael R; Dzwonczyk, Roger

    2015-12-01

    Clamping and shunting during carotid endarterectomy (CEA) surgery causes changes in cerebral blood flow. The purpose of this study was to assess and compare, side by side, the cerebral oxygenation (rSO2) and processed electroencephalogram (EEG) response bilaterally to carotid artery clamping and shunting in patients undergoing CEA under general anesthesia. With institutional approval and written informed consent, patients undergoing CEA under general anesthesia and routine carotid artery shunting were recorded bilaterally, simultaneously and continuously with an rSO2 and processed EEG monitor. The response of the monitors during carotid artery clamping and shunting were assessed and compared between monitors and bilaterally within each monitor. Sixty-nine patients were included in the study. At clamping the surgical-side and contralateral-side rSO2 dropped significantly below the baseline incision value (-17.6 and -9.4% respectively). After shunting, the contralateral-side rSO2 returned to baseline while the surgical-side rSO2 remained significantly below baseline (-9.0%) until the shunt was removed following surgery. At clamping the surgical-side and contralateral-side processed EEG also dropped below baseline (-19.9 and -20.6% respectively). However, following shunt activation, the processed EEG returned bilaterally to baseline. During the course of this research, we found the rSO2 monitor to be clinically more robust (4.4% failure rate) than the processed EEG monitor (20.0% failure rate). There was no correlation between the rSO2 or processed EEG changes that occurred immediately after clamping and the degree of surgical side stenosis measured pre-operatively. Both rSO2 and processed EEG respond to clamping and shunting during CEA. Cerebral oximetry discriminates between the surgical and contralateral side during surgery. The rSO2 monitor is more reliable in the real-world clinical setting. Future studies should focus on developing algorithms based on these

  12. 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.

  13. 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.

  14. Arterial blood pressure regulation following aorta clamping and declamping during surgery.

    Science.gov (United States)

    Ferrario, Manuela; Aletti, Federico; Toschi, Nicola; Canichella, Antonio; Coniglione, Filadelfo; Sabato, Elisabetta; Della Badia Giussi, Florencia; Dauri, Mario; Sabato, Alessandro F; Guerrisi, Maria; Cerutti, Sergio

    2011-01-01

    In this paper, we propose the use of black box models for the system identification of the cardiopulmonary baroreflex control of arterial resistance and of ventricular contractility and of arterial baroreflex control of heart rate (HR) from invasive, continuous measurements of arterial blood pressure (ABP) and central venous pressure (CVP), and non invasive, continuous recordings of ECG and respiration. Two crucial phases of the abdominal aortic aneurism (AAA) repair were investigated: the clamping and declamping of aorta. The objective of the present work is to evaluate and to test the ability to monitor baroreflex responses to clamping and declamping maneuvers preceding and following aneurism removal. PMID:22256303

  15. 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.

  16. 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...

  17. 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

  18. 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%.

  19. Critical clamp loader processing by an essential AAA+ protease in Caulobacter crescentus.

    Science.gov (United States)

    Vass, Robert H; Chien, Peter

    2013-11-01

    Chromosome replication relies on sliding clamps that are loaded by energy-dependent complexes. In Escherichia coli, the ATP-binding clamp loader subunit DnaX exists as both long (τ) and short (γ) forms generated through programmed translational frameshifting, but the need for both forms is unclear. Here, we show that in Caulobacter crescentus, DnaX isoforms are unexpectedly generated through partial proteolysis by the AAA+ protease casein lytic proteinase (Clp) XP. We find that the normally processive ClpXP protease partially degrades DnaX to produce stable fragments upon encountering a glycine-rich region adjacent to a structured domain. Increasing the sequence complexity of this region prevents partial proteolysis and generates a τ-only form of DnaX in vivo that is unable to support viability on its own. Growth is restored when γ is provided in trans, but these strains are more sensitive to DNA damage compared with strains that can generate γ through proteolysis. Our work reveals an unexpected mode of partial processing by the ClpXP protease to generate DnaX isoforms, demonstrates that both τ and γ forms of DnaX are required for Caulobacter viability, and identifies a role for clamp loader diversity in responding to DNA damage. The conservation of distinct DnaX isoforms throughout bacteria despite fundamentally different mechanisms for producing them suggests there may be a conserved need for alternate clamp loader complexes during DNA damaging conditions.

  20. 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...

  1. Five-Level Active-Neutral-Point-Clamped DC/DC Converter

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    2016-01-01

    Multi-level converters are getting more and more attentions because of their obvious merits such as lower voltage stress and harmonic, smaller size of output filters, and so on. In this paper, a five-level active-neutral-point-clamped (5L-ANPC) dc/dc converter is proposed for power transfer...

  2. Five-Level Active-Neutral-Point-Clamped DC/DC Converter

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    Multi-level converters are getting more and more attentions because of their obvious merits such as lower voltage stress and harmonic, smaller size of output filters, and so on. In this paper, a five-level active-neutral-point-clamped (5L-ANPC) dc/dc converter is proposed for power transfer...

  3. Diuretic response to acute hypertension is blunted during angiotensin II clamp

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Zhang, Yibin; Yang, Li E;

    2002-01-01

    and endogenous lithium clearance increased two- and threefold, respectively. We conclude that HOE-140, an inhibitor of the B(2) receptor, potentiates the sensitivity of arterial pressure to ANG II and that clamping systemic ANG II levels during acute hypertension blunts the magnitude of the pressure diuretic...

  4. 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-volta...

  5. 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.

  6. 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

  7. Glucose consumption by various tissues in pregnant rats : effects of a 6-day euglycaemic hyperinsulinaemic clamp

    NARCIS (Netherlands)

    Nieuwenhuizen, AG; Schuiling, GA; Bonen, A; Paans, AMJ; Vaalburg, W; Koiter, TR

    1998-01-01

    In the course of pregnancy maternal tissues become increasingly more insensitive to insulin. As 6 days of euglycaemic hyperinsulinaemic clamping, from day 8 until 14 of gestation, ameliorates total glucose consumption, we analysed the contribution of individual tissues in this phenomenon. We measure

  8. 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.

  9. 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

  10. 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...

  11. Evaluation of diel patterns of relative changes in cell turgor of tomato plants using leaf patch clamp pressure probes

    NARCIS (Netherlands)

    Lee, K.M.; Driever, S.M.; Heuvelink, E.; Rüger, S.; Zimmermann, U.; Gelder, de A.; Marcelis, L.F.M.

    2012-01-01

    Relative changes in cell turgor of leaves of well-watered tomato plants were evaluated using the leaf patch clamp pressure probe (LPCP) under dynamic greenhouse climate conditions. Leaf patch clamp pressure changes, a measure for relative changes in cell turgor, were monitored at three different hei

  12. 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.)

  13. Evidence of mirror neurons in human inferior frontal gyrus.

    Science.gov (United States)

    Kilner, James M; Neal, Alice; Weiskopf, Nikolaus; Friston, Karl J; Frith, Chris D

    2009-08-12

    There is much current debate about the existence of mirror neurons in humans. To identify mirror neurons in the inferior frontal gyrus (IFG) of humans, we used a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging. Subjects either executed or observed a series of actions. Here we show that in the IFG, responses were suppressed both when an executed action was followed by the same rather than a different observed action and when an observed action was followed by the same rather than a different executed action. This pattern of responses is consistent with that predicted by mirror neurons and is evidence of mirror neurons in the human IFG.

  14. 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

  15. 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

  16. Laparoscopic management of inferior lumbar hernia (Petit triangle hernia).

    Science.gov (United States)

    Ipek, T; Eyuboglu, E; Aydingoz, O

    2005-05-01

    Lumbar hernias are rare defects in the posterolateral abdominal wall that may be congenital or acquired. We present a case of laparoscopic approach to repair an acquired inferior triangle (Petit) lumbar hernia in a woman by using polytetrafluoroethylene mesh. The size of the hernia was 8 x 10 cm. The length of her hospital stay was 2 days. The patient resumed normal activities in less than 2 weeks. The main advantage of this approach is excellent operative visualization, thus avoiding injury to structures near the hernia during repair. Patients benefit from a minimally invasive approach with less pain, shortened hospital course, less analgesic requirements, better cosmetic result, and minimal life-style interference.

  17. Renal transplantation in a child with thrombosed inferior vena cava

    Directory of Open Access Journals (Sweden)

    Surjeet Kumar

    2014-01-01

    Full Text Available The external iliac vein is commonly used in renal transplantation for vascular anastomosis of the allograft renal vein. However, there are rare instances when the transplant surgeon may encounter thrombosis of the ilio-caval vein during surgery, making renal transplantation a challenge. Often, these patients are considered unsuitable for renal transplantation. We report a case of thrombosis of the inferior vena cava in an asymptomatic pediatric patient in whom the splenic vein was used, at transplantation, for venous drainage. This case highlights that pre-operative Doppler screening should be performed in all potential renal transplant recipients.

  18. 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)

  19. Retro-aortic, left inferior renal capsular vein

    Directory of Open Access Journals (Sweden)

    Umberto G Rossi

    2015-01-01

    Full Text Available In our case report, abdominal multi-detector computed tomography was used for the pre-operative anatomy evaluation in a living kidney donor. The early phase of the test revealed normal kidneys in the donor. The vascular phase detected a venous variant on the left side: An inferior renal capsular vein, which had a loop and a retro-aortic course. This preoperative knowledge was crucial for the laparoscopic nephrectomy as a surgical procedure for harvesting kidney from the living donor.

  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 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.

  2. 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)

  3. Ventilation before Umbilical Cord Clamping improves the physiological transition at birth.

    Directory of Open Access Journals (Sweden)

    Sasmira eBhatt

    2014-10-01

    Full Text Available The transition from a fetus to a neonate at birth represents a critical phase in our life. Most infants make this transition without complications, but preterm infants usually require some form of assistance due to immature cardiopulmonary systems that predispose them to lifelong sequelae. As the incidence of preterm birth is increasing, there is now an urgent need for the development of management strategies that facilitate this transition, which will likely include improved strategies for the management of the maternal third stage of labour. For instance, recent studies on the physiological transition at birth have led to the discovery that establishing ventilation in the infant before the umbilical cord is clamped greatly stabilizes the cardiovascular transition at birth. While most benefits of delayed clamping have previously been attributed to an increase in placenta to infant blood transfusion, clearly there are other significant benefits for the infant, which are not well understood. Nevertheless, if ventilation can be established before cord clamping in a preterm infant, the large adverse changes in cardiac function that normally accompanies umbilical cord clamping can be avoided. As preterm infants have an immature cerebral vascular bed, large swings in cardiovascular function places them at high risk of cerebral vascular rupture and the associated increased risk of mortality and morbidity. In view of the impact that cord clamping has on the cardiovascular transition at birth, it is also time to re-examine some of the strategies used in the management of the third stage of labour. These include the appropriate timing of uterotonic administration in relation to delivery of the infant and placenta. As there is a lack of evidence on the effects these individual practices have on the infant, there is a necessity to improve our understanding of their impact in order to develop strategies that facilitate the transition to newborn life.

  4. 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.

  5. 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.

  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. 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.

  8. Testing and evaluation of stretching strain in clamped–clamped beams for energy harvesting

    Science.gov (United States)

    Emad, Ahmed; Mahmoud, Mohamed A. E.; Ghoneima, Maged; Dessouky, Mohamed

    2016-11-01

    In this paper, evaluation of stretching strain capabilities to harvest energy from a piezoelectric clamped–clamped beam is theoretically modeled and experimentally tested. The utilization of stretching strain has many advantages as: elimination of any substrate material, and the simple electrode configuration. The doubly clamped structure exhibits a highly nonlinear frequency response (Hardening Duffing) that widens the bandwidth during the frequency up-ward sweep. The wide bandwidth makes it suitable for practical applications. A design of 53.5 {{mm}}3 (29.7 {{mm}}3 piezoelectric material + 23.8 {{mm}}3 proof mass) energy harvester was tested using PVDF (polyvinylidene fluoride) that can generate up to 15 μW from vibrations of 0.5{g} at 128 {Hz} and 2 MΩ load. The design can also generate up to 41 μ {{W}} from vibrations of 1{g} at 140 {Hz} and 2 MΩ load.

  9. 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

  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. 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 ... 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 Sip (7.1 vs 9.41(2) x kg(-1) x min(-1) x mmol(-1), p

  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. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. Inhibition and the right inferior frontal cortex: one decade on.

    Science.gov (United States)

    Aron, Adam R; Robbins, Trevor W; Poldrack, Russell A

    2014-04-01

    In our TICS Review in 2004, we proposed that a sector of the right inferior frontal cortex (rIFC) in humans is critical for inhibiting response tendencies. Here we survey new evidence, discuss ongoing controversies, and provide an updated theory. We propose that the rIFC (along with one or more fronto-basal-ganglia networks) is best characterized as a brake. This brake can be turned on in different modes (totally, to outright suppress a response; or partially, to pause), and in different contexts (externally, by stop or salient signals; or internally, by goals). We affirm inhibition as a central component of executive control that relies upon the rIFC and associated networks, and explain why rIFC disruption could generally underpin response control disorders.

  20. 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 proce...... and physiological response to OER in fish indicates that frustration is an evolutionarily conserved affective state. Moreover, our results indicate that aggressive motivation to reward unpredictability affects low RHP individuals strongest...... processes can alter contest dynamics, but the interaction between such effects and that of differing RHPs has not been adjudged. We investigated effects of omission of expected reward (OER) on competing individuals with contrasting RHPs. Small and large rainbow trout (Oncorhynchus mykiss) were conditioned...... 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...

  1. Scorpion envenomation-induced acute thrombotic inferior myocardial infarction.

    Science.gov (United States)

    Baykan, Ahmet Oytun; Gür, Mustafa; Acele, Armağan; Şeker, Taner; Çaylı, Murat

    2016-01-01

    The occurrence of a serious cardiac emergency following scorpion envenomation has rarely been reported and, when so, mostly presented as non-ST segment elevation myocardial infarction, cardiogenic shock, or myocarditis. Possible mechanisms include imbalance in blood pressure and coronary vasospasm caused by the combination of sympathetic excitation, scorpion venom-induced release of catecholamines, and the direct effect of the toxin on the myocardium. We report a case of a 55-year-old man who presented with acute inferior wall myocardial infarction (MI) within 2 h of being stung by a scorpion. Coronary angiogram revealed total thrombotic occlusion of the left circumflex artery, which was treated successfully with glycoprotein IIb/IIIa inhibitor, thrombus aspiration, antivenom serum, and supportive therapy. Therefore, life-threatening MI can complicate the clinical course during some types of scorpion envenomation and should be managed as an acute coronary syndrome. PMID:26875137

  2. 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.)

  3. 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...

  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. 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...

  6. 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.

  7. Microwave electromechanical resonator consisting of clamped carbon nanotubes in an abacus arrangement

    Science.gov (United States)

    Peng, H. B.; Chang, C. W.; Aloni, S.; Yuzvinsky, T. D.; Zettl, A.

    2007-07-01

    We describe nanoscale electromechanical resonators capable of operating in ambient-pressure air at room temperature with unprecedented fundamental resonance frequency of ˜4GHz . The devices are created from suspended carbon nanotubes loaded abacus style with inertial metal clamps, yielding short effective beam lengths. We examine the energy dissipation in the system due to air damping and contact loss. Such nanoabacus resonators open windows for immediate practical microwave frequency nanoelectromechanical system applications.

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

    Directory of Open Access Journals (Sweden)

    S. Kastelic

    2010-10-01

    Full Text Available 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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,...

  13. 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...... 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....

  14. 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...

  15. Pseudoaneurisma Ventricular Izquierdo en Cara Inferior con Flujo Bidireccional

    Directory of Open Access Journals (Sweden)

    Adrián J Da Silva-De Abreu

    2011-01-01

    Full Text Available Los pseudoaneurismas son complicaciones infrecuentes de los infartos del miocardio. Consisten en un saco pericárdico que comunica con la cavidad ventricular a través de un cuello de menor diámetro. Se presenta el caso de una paciente de 68 años de edad, con DM II e HTA, sufre Infarto Agudo del Miocardio en Mayo del 2008, presentando disnea y tos por una semana, con diaforesis profusa de inicio súbito y síncope sin dolor precordial. El electrocardiograma reporta zonas de isquemia transmural y subendocárdica en caras inferolateral y lateral alta; respectivamente, y zona eléctricamente inactivable en cara inferior. El ecocardiograma transtorácico muestra el ventrículo izquierdo con dilatación severa, disminución de la fracción de eyección (25% y un pseudoaneurisma de la pared inferior con cuello de 3 mm a través del cual se evidencia flujo bidireccional: de entrada al ventrículo durante la diástole y salida al pseudoaneurisma en sístole. El flujo bidireccional y el gasto cardíaco disminuido contribuyen a evitar el taponamiento cardiaco, sin embargo, en condiciones de mayor demanda el pseudoaneurisma podría perforarse y ocasionar dicha entidad. De ello, la importancia del diagnostico diferencial con los aneurismas verdaderos, lo cual permite llevar a cabo la terapéutica adecuada y evitar tal complicación. Palabras claves: Pseudoaneurisma, Infarto del Miocardio, Diabetes.

  16. Pseudoaneurisma Ventricular Izquierdo en Cara Inferior con Flujo Bidireccional

    Directory of Open Access Journals (Sweden)

    Adrián J Da Silva-De Abreu

    2009-01-01

    Full Text Available Los pseudoaneurismas son complicaciones infrecuentes de los infartos del miocardio. Consisten en un saco pericárdico que comunica con la cavidad ventricular a través de un cuello de menor diámetro. Se presenta el caso de una paciente de 68 años de edad, con DM II e HTA, sufre Infarto Agudo del Miocardio en Mayo del 2008, presentando disnea y tos por una semana, con diaforesis profusa de inicio súbito y síncope sin dolor precordial. El electrocardiograma reporta zonas de isquemia transmural y subendocárdica en caras inferolateral y lateral alta, respectivamente, y zona eléctricamente inactivable en cara inferior. El ecocardiograma transtorácico muestra el ventrículo izquierdo con dilatación severa, disminución de la fracción de eyección (25% y un pseudoaneurisma de la pared inferior con cuello de 3 mm a través del cual se evidencia flujo bidireccional, de entrada al ventrículo durante la diástole y salida al pseudoaneurisma en sístole. El flujo bidireccional y el gasto cardíaco disminuido contribuyen a evitar el taponamiento cardiaco, sin embargo, en condiciones de mayor demanda el pseudoaneurisma podría perforarse y ocasionar dicha entidad. De ello, la importancia del diagnostico diferencial con los aneurismas verdaderos, lo cual permite llevar a cabo la terapéutica adecuada y evitar tal complicación.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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 ...

  2. 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

  3. 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.

  4. 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

  5. Leiomioma benigno metastatizante de veia cava inferior: rara complicação tardia de histerectomia Benign metastasizing leiomyoma of inferior vena cava: a rare condition following hysterectomy

    Directory of Open Access Journals (Sweden)

    Marcos Filgueiras

    2008-08-01

    Full Text Available Large vessel tumors diagnosis is usually difficult. Benign metastasizing leiomyoma is a rare condition occurring inside peripheral vessels. There are few publications about this tumor inside inferior vena cava. A 54 years old female patient is presented with a previous hysterectomy for myomas. She complained of no specific symptoms 18 months after surgery. Computer tomography revealed a 7.5 x 3.5 x 4.0 cm mass at inferior vena cava and right psoas muscle. After surgical management and immunohistochemical screening biopsy, the diagnosis was benign metastasizing leiomyoma of inferior vena cava. The patient recovery was uneventful. Benign metastasizing leiomyoma of inferior vena cava is a very rare condition, and must be suspected in patients with primary leiomyosarcoma, especially in women previously submitted to hysterectomy for leiomyomatosis.

  6. 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.

  7. 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.…

  8. Deep venous thrombosis in a young woman with hypoplastic inferior vena cava.

    Science.gov (United States)

    Lavens, Matthias; Moors, Boudewijn; Thomis, Sarah

    2014-05-01

    We present a 33-year-old woman with deep venous thrombosis of the left iliac vein and the left lower limb. A computed tomography scan of her abdomen revealed a hypoplastic inferior vena cava and agenesis of the right kidney. Congenital anomalies of the inferior vena cava are uncommon and are sometimes an unrecognized cause of deep venous thrombosis.

  9. 75 FR 9228 - Draft Guidance for Industry on Non-Inferiority Clinical Trials; Availability

    Science.gov (United States)

    2010-03-01

    ... ``Non- Inferiority Clinical Trials.'' This draft guidance provides sponsors and review staff in the... announcing the availability of a draft guidance for industry entitled ``Non-Inferiority Clinical Trials... clinical trials. It does not create or confer any rights for or on any person and does not operate to...

  10. 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.

  11. 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

  12. 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

  13. Dopaminergic Input to the Inferior Colliculus in Mice

    Directory of Open Access Journals (Sweden)

    Alexander A Nevue

    2016-01-01

    Full Text Available The response of sensory neurons to stimuli can be modulated by a variety of factors including attention, emotion, behavioral context, and disorders involving neuromodulatory systems. For example, patients with Parkinson’s disease have disordered speech processing, suggesting that dopamine alters normal representation of these salient sounds. Understanding the mechanisms by which dopamine modulates auditory processing is thus an important goal. The principal auditory midbrain nucleus, the inferior colliculus (IC, is a likely location for dopaminergic modulation of auditory processing because it contains dopamine receptors and nerve terminals immunoreactive for tyrosine hydroxylase (TH, the rate-limiting enzyme in dopamine synthesis. However, the sources of dopaminergic input to the IC are unknown. In this study, we iontophoretically injected a retrograde tracer into the IC of mice and then stained the tissue for TH. We also immunostained for dopamine beta-hydroxylase (DBH, an enzyme critical for the conversion of dopamine to norepinephrine, to differentiate between dopaminergic and noradrenergic inputs. Retrogradely labeled neurons that were positive for TH were seen bilaterally, with strong ipsilateral dominance, in the subparafascicular thalamic nucleus (SPF. All retrogradely labeled neurons that we observed in other brain regions were TH-negative. Projections from the SPF were confirmed using an anterograde tracer, revealing TH-positive and DBH-negative anterogradely labeled fibers and terminals in the IC. While the functional role of this dopaminergic input to the IC is not yet known, it provides a potential mechanism for context dependent modulation of auditory processing.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... 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...

  20. 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.

  1. 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

  2. Longitudinal relaxation of mechanically clamped KH2PO4 type crystals

    Directory of Open Access Journals (Sweden)

    R.R. Levitskii

    2012-10-01

    Full Text Available Within the framework of a modified proton ordering model of the KH2PO4 family ferroelectric crystals, taking into account a linear over the strain ϵ6 contribution into the proton system energy, we obtain an expression for longitudinal dynamic dielectric permittivity of a mechanically clamped crystal using the four-particle cluster approximation and the dynamic Glauber approach. At a proper choice of the model parameters, we obtain a good quantitative description of available experimental data for these crystals.

  3. 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;

    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...

  4. 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

    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 (mmHg, decreased urine output, and shifted NHE3 and NaPi2 out of the low...... in 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...

  5. 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

  6. Exaggerated natriuresis during clamping of systemic NO supply in healthy young men

    DEFF Research Database (Denmark)

    Simonsen, Jane Angel; Rasmussen, Mona S; Vach, Werner;

    2012-01-01

    -nitro-L-arginine methyl ester; bolus of 750 μg·kg-1 of body weight and 8.3 μg·min-1·kg-1 of body weight] and SNP (sodium nitroprusside), the latter at a rate preventing L-NAME from increasing total peripheral resistance ('NO-clamping'). Slow volume expansion (saline, 20 μmol of NaCl·min-1·kg-1 of body weight for 3 h...

  7. 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...

  8. 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

  9. Dynamic Gain-Clamped Amplifier with Backward-Injection of a Fabry-Perot Laser

    Institute of Scientific and Technical Information of China (English)

    Chien-Hung; Yeh; Chih-Yang; Chen; Chien-Chung; Lee; Sien; Chi

    2003-01-01

    We have been experimentally demonstrated an active control technique of dynamic gain-clamped spectra for theerbium-doped fiber amplifiers (EDFA's) by a backward-injected Fabry-Perot (F-P) laser into this EDFA. In addition, employing a short length erbium-doped fiber (EDF) that not cause any gain saturation for preamplification in front of this amplifier module, it can reduce the noise figure degradation and simultaneously achieve gain variation from 11.1 dB to 0.5 dB for 10 dB input power level change.

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

    OpenAIRE

    Sona P; Sheela Joseph

    2014-01-01

    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 re...

  11. 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

  12. 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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    -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......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...

  15. Transverse Vibrations of Clamped and Simply-Supported Circular Plates with Two Dimensional Thickness Variation

    Directory of Open Access Journals (Sweden)

    N. Bhardwaj

    2012-01-01

    Full Text Available Two dimensional boundary characteristic orthonormal polynomials are used in the Ritz method for the vibration analysis of clamped and simply-supported circular plates of varying thickness. The thickness variation in the radial direction is linear whereas in the circumferential direction the thickness varies according to cos kθ, where k is an integer. In order to verify the validity, convergence and accuracy of the results, comparison studies are made against existing results for the special case of linearly tapered thickness plates. Variations in frequencies for the first six normal modes of vibration and mode shapes for various taper parameters are presented.

  16. 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)

  17. 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)

  18. 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...

  19. 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...

  20. 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. ...

  1. Gain Clamped Two-Stage Double-Pass L-Band EDFA with a Single Fibre Bragg Grating

    Institute of Scientific and Technical Information of China (English)

    Sulaiman Wadi Harun; Harith Ahmad

    2004-01-01

    A gain clamping is demonstrated in a two-stage double-pass L-band erbium-doped fibre amplifier (EDFA) by using a single fibre Bragg grating. Two types of the fibre-Bragg-grating (FBG) broadband and narrowband have been used in the gain-clamped system. The combinatiox of the FBG and the optical circulator has created a laser in the cavity for gain clamping. The application ora broadband FBG has improved the amplifier's efficiency and noise figure compared to the narrowband FBG system. The gain is clamped at about 22.1 dB for the amplifier with broadband FBG with gain variation of less than ±0.15 dB and the input saturation power Psat at -8 dBm.The gain varies from 19.0 to 25.4dB in the signal wavelength region of 1574nm-1604nm. The noise figure varies from 6.0 to 10. 8dB at this wavelength range. The noise figure values are found to improve by as much as 0.3-1.1 dB when compared to the unclamped amplifier for signal wavelengths above 1580nm. The high clamped gain and low noise figure are obtained due to the suppression of the backward C-band amplified spontaneous emission. The gain clamped amplifier shows only a small power excursions when three of the four channels are added/dropped. The effects of relaxation oscillation are not seen for the gain-clamped two-stage double-pass L-band EDFA.

  2. 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

  3. A Molecular Imaging Approach to Mercury Sensing Based on Hyperpolarized (129)Xe Molecular Clamp Probe.

    Science.gov (United States)

    Guo, Qianni; Zeng, Qingbin; Jiang, Weiping; Zhang, Xiaoxiao; Luo, Qing; Zhang, Xu; Bouchard, Louis-S; Liu, Maili; Zhou, Xin

    2016-03-14

    Mercury pollution, in the form of mercury ions (Hg(2+)), is a major health and environmental hazard. Commonly used sensors are invasive and limited to point measurements. Fluorescence-based sensors do not provide depth resolution needed to image spatial distributions. Herein we report a novel sensor capable of yielding spatial distributions by MRI using hyperpolarized (129)Xe. A molecular clamp probe was developed consisting of dipyrrolylquinoxaline (DPQ) derivatives and twocryptophane-A cages. The DPQ derivatives act as cation receptors whereas cryptophane-A acts as a suitable host molecule for xenon. When the DPQ moiety interacts with mercury ions, the molecular clamp closes on the ion. Due to overlap of the electron clouds of the two cryptophane-A cages, the shielding effect on the encapsulated Xe becomes important. This leads to an upfield change of the chemical shift of the encapsulated Xe. This sensor exhibits good selectivity and sensitivity toward the mercury ion. This mercury-activated hyperpolarized (129)Xe-based chemosensor is a new concept method for monitoring Hg(2+) ion distributions by MRI.

  4. 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.

  5. 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

  6. 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...

  7. 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...

  8. 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...

  9. 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.

  10. Simple circuit to improve electric field homogeneity in contour-clamped homogeneous electric field chambers.

    Science.gov (United States)

    Herrera, José A; Canino, Carlos A; López-Cánovas, Lilia; Gigato, Regnar; Riverón, Ana Maria

    2003-04-01

    We redesigned contour-clamped homogeneous electric field (CHEF) circuitry to eliminate crossover distortion, to set identical potentials at electrodes of each equipotential pair and to drive pairs with transistors in emitter follower stages. An equipotential pair comprised the two electrodes set at the same potential to provide electric field homogeneity inside of the hexagonal array. The new circuitry consisted of two identical circuits, each having a resistor ladder, diodes and transistors. Both circuits were interconnected by diodes that controlled the current flow to electrodes when the array was energized in the 'A' or 'B' direction of the electric field. The total number of transistors was two-thirds of the total number of electrodes. Average voltage deviation from potentials expected at electrodes to achieve a homogeneous electric field was 0.06 V, whereas 0.44 V was obtained with another circuit that used transistors in push-pull stages. The new voltage clamp unit is cheap, generated homogeneous electric field, and gave reproducible and undistorted DNA band patterns. PMID:12707904

  11. 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)

  12. 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.

  13. Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams

    KAUST Repository

    Alcheikh, N

    2016-05-06

    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. © 2016 IOP Publishing Ltd.

  14. Correlation of open cell-attached and excised patch clamp techniques.

    Science.gov (United States)

    Filipovic, D; Hayslett, J P

    1995-11-01

    The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the nystatin-induced open cell-attached patch could serve as an alternative configuration. Compared to excised inside-out patches, stable preparations were achieved more readily with the open cell-attached patch (9% vs. 56% of attempts). In both preparations, the current voltage (I-V) relation was linear, current amplitudes were equal at opposite equivalent clamped voltages, and Erev was zero in symmetrical Na+ solutions, indicating similar Na+ activities on the cytosolic and external surfaces of the patch. Moreover, there was no evidence that nystatin altered channel activity in the patch because slope conductance (3-4pS) and Erev (75 mV), when the bath was perfused with a high K:low Na solution (ENa = 80 mV), were nearly equal in both patch configurations. Our results therefore indicate that the nystatin-induced open cell-attached patch can serve as an alternative approach to the excised inside-out patch when experiments require modulation of univalent ions in the cytosol.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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.

  2. 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

  3. 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

  4. 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

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

    Science.gov (United States)

    Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

    2013-07-01

    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. PMID:23902112

  6. 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.

  7. 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

  8. 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...

  9. Hypertrophic degeneration of the inferior olivary nucleus impacts perception of gravity

    Directory of Open Access Journals (Sweden)

    Alexander A Tarnutzer

    2012-05-01

    Full Text Available Interruption of the Guillain-Mollaret triangle interconnecting the red nucleus, the inferior olivary nucleus and the contralateral dentate nucleus is predicted to interfere with the dentate nucleus’ role in estimating direction of gravity. In a patient with pendular nystagmus due to hypertrophic inferior olivary nucleus degeneration secondary to ponto-mesencephalic hemorrhage, perceived vertical shifted from clockwise to counter-clockwise deviations within 4 months. We hypothesize that synchronized oscillations of inferior olivary nucleus neurons induce a loss of inhibitory control, leading to hyperactivity of the contralateral dentate nucleus and, as a result, to perceived vertical roll-tilt to the side of the overactive dentate nucleus.

  10. 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

  11. Surgical treatment for ruptured anterior inferior cerebellar artery aneurysms

    Directory of Open Access Journals (Sweden)

    TONG Xiao-guang

    2013-03-01

    Full Text Available Background Anterior inferior cerebellar artery (AICA aneurysm is an extremely raretumor, which can cause severe results after ruptured. This article retrospectively analyzed the clinical symptoms, imaging manifestations, surgical approaches, endovascular therapy and postoperative outcomes of 12 cases with AICA aneurysms, so as to provide reference for clinical practice. Methods Clinical data of patients with AICA aneurysms, who were treated in our hospital between June 2004 and June 2012, were carefully collected and studied. Glasgow Outcome Scale (GOS scores were used to evaluate the patients' living status. Results There were 12 patients (the average age was 54 years old with 13 ruptured aneurysms, accounting for 0.19% of all aneurysms (6467 cases treated in the same period. CT showed simple subarachnoid hemorrhage (SAH in 6 patients, simple ventricular hemorrhage in 1 patient and SAH complicated with ventricular hemorrhage in 5 patients. According to Hunt-Hess Grade, 2 patients were classified as Grade Ⅰ; 7 were Grade Ⅱ; 3 were Grade Ⅲ. Digital subtraction angiography (DSA showed there were 10 saccular aneurysms and 3 fusiform aneurysms. Three aneurysms were located in the proximal segment of AICA (the junction of AICA and basilar artery, 3 premeatal segment (first bifurcation of AICA, 3 meatal and 4 postmeatal. The mean diameter was 3.90 mm. Three patients with 4 aneurysms were treated with microsurgery, of which clipping was carried out in 2 patients with 3 aneurysms and trapping in 1 case. Other 9 patients were treated with endovascular therapy, of which 2 cases underwent coil embolization, 3 stent-assisted coil, and 4 parent artery occlusion (PAO. Postoperative complications included facial paralysis (1 case, dysphagia and coughing when drinking (1 case and contralateral hemianopia in both eyes (1 case. Follow-up was available in all of these cases for a mean of 36.41 months, with GOS scores 3 in 1 case, 4 in 2 cases and 5 in 9

  12. 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...

  13. Testing of New Materials and Computer Aided Optimization of Process Parameters and Clamping Device During Predevelopment of Laser Welding Processes

    Science.gov (United States)

    Weidinger, Peter; Günther, Kay; Fitzel, Martin; Logvinov, Ruslan; Ilin, Alexander; Ploshikhin, Vasily; Hugger, Florian; Mann, Vincent; Roth, Stephan; Schmidt, Michael

    The necessity for weight reduction in motor vehicles in order to save fuel consumption pushes automotive suppliers to use materials of higher strength. Due to their excellent crash behavior high strength steels are increasingly applied in various structures. In this paper some predevelopment steps for a material change from a micro alloyed to dual phase and complex phase steels of a T-joint assembly are displayed. Initially the general weldability of the materials regarding pore formation, hardening in the heat affected zone and hot cracking susceptibility is discussed. After this basic investigation, the computer aided design optimization of a clamping device is shown, in which influences of the clamping jaw, the welding position and the clamping forces upon weld quality are presented. Finally experimental results of the welding process are displayed, which validate the numerical simulation.

  14. 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

  15. Mycobacterium tuberculosis class II apurinic/apyrimidinic-endonuclease/3'-5' exonuclease III exhibits DNA regulated modes of interaction with the sliding DNA β-clamp.

    Science.gov (United States)

    Khanam, Taran; Rai, Niyati; Ramachandran, Ravishankar

    2015-10-01

    The class-II AP-endonuclease (XthA) acts on abasic sites of damaged DNA in bacterial base excision repair. We identified that the sliding DNA β-clamp forms in vivo and in vitro complexes with XthA in Mycobacterium tuberculosis. A novel 239 QLRFPKK245 motif in the DNA-binding domain of XthA was found to be important for the interactions. Likewise, the peptide binding-groove (PBG) and the C-terminal of β-clamp located on different domains interact with XthA. The β-clamp-XthA complex can be disrupted by clamp binding peptides and also by a specific bacterial clamp inhibitor that binds at the PBG. We also identified that β-clamp stimulates the activities of XthA primarily by increasing its affinity for the substrate and its processivity. Additionally, loading of the β-clamp onto DNA is required for activity stimulation. A reduction in XthA activity stimulation was observed in the presence of β-clamp binding peptides supporting that direct interactions between the proteins are necessary to cause stimulation. Finally, we found that in the absence of DNA, the PBG located on the second domain of the β-clamp is important for interactions with XthA, while the C-terminal domain predominantly mediates functional interactions in the substrate's presence.

  16. Research and development of a self-centering clamping device for deep-water multifunctional pipeline repair machinery

    Directory of Open Access Journals (Sweden)

    Liquan Wang

    2016-01-01

    Full Text Available When multifunctional pipeline repair machinery (MPRM is used in the deep sea area, it is difficult to grip the pipeline and ensure concentricity between the cutter heads and the pipeline during its operation. In view of this, a new system of two-arm holding self-centering pipeline clamping device was proposed. The system is composed of two groups of parallelogram double-rocker mechanism and cranking block mechanism which are symmetrically distributed on the frame. The geometric parameter solutions of the clamping device were analyzed with motion and transmission as the constraints. A mechanical model was established to associate the friction torque of clamping points with the driving force. Clamping device and machinery were designed and manufactured for the Ø304.8–457.2 mm pipelines used in this test. ADAMS simulation experiments were conducted underwater, and the cutting and beveling tests were carried out onshore. The following results are achieved. First, the smaller the pipe diameter, the smaller the transmission angle of the oscillating slider mechanism; the longer the hydraulic cylinder stroke, the greater the transmission angle of the double rocker mechanism. Second, the driving force of the clamping device increases with the increase of the pipe diameter. When the diameter reaches 457.2 mm, the hydraulic cylinder driving force of the clamping device should be greater than 10219 N. Third, the feed rate of the cutters increases suddenly due to the slight shaking of the machinery which occurs at the beginning of the pipe cutting, so it is necessary to adopt a small feed rate. And fourth, onshore experiment results agree well with the theoretical design and simulation results, proving the rationality of the system. The research results in this paper provide technical basis for the research and development of similar engineering prototypes.

  17. 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

  18. Deep Venous Thrombosis Associated With Inferior Vena Cava Abnormalities And Hypoplastic Kidney In Siblings

    Directory of Open Access Journals (Sweden)

    Duicu Carmen

    2016-06-01

    Full Text Available Congenital inferior vena cava anomalies have a reduced frequency in general population, many times being an asymptomatic finding. Patients caring such anomalies are at risk to develop deep vein thrombosis. In this paper, we present 2 siblings with deep venous thrombosis and inferior vena cava abnormalities, with a symptomatic onset at similar age. The inferior vena cava abnormality was documented by an angio-CT in each case. The thrombophilic workup was negative. Patients were treated with conservative therapy: low molecular weight heparin anticoagulants converted later to oral anticoagulant with resolution of symptoms and disappearance of the thrombus. Finally, in the absence of any risk factor in a young patient admitted with deep vein thrombosis investigations to exclude inferior vena cava anomalies are mandatory.

  19. [Calcified bullet thrombus of the inferior vena cava and left renal vein in an adult].

    Science.gov (United States)

    Leclerc, A; Lapébie, F-X; Thuillier, F; Lacroix, P

    2016-07-01

    Calcifications are rarely located within the inferior vena cava and the renal veins. The etiology is poorly understood and the prognosis is uncertain. We report a case in a 55-year-old man. PMID:27344300

  20. 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.

  1. 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

  2. How to explant a diseased liver for living donor liver transplantation after previous gastrectomy with severe adhesion (with video).

    Science.gov (United States)

    Eguchi, Susumu; Soyama, Akihiko; Takatsuki, Mitsuhisa; Hidaka, Masaaki; Adachi, Tomohiko; Kitasato, Amane; Baimakhanov, Zhassulan; Kuroki, Tamotsu

    2014-08-01

    We performed living donor liver transplantation (LDLT) in a patient who had undergone distal gastrectomy for gastric ulcer disease with Billroth I reconstruction 30 years before the LDLT. The adhesion was very severe between remnant stomach and hepatic hilum as well as left liver lobe with shortening of hepatoduodenal structures. After dissection of the infrahepatic inferior vena cava, the Spiegel lobe was identified from the dorsal side. The Spiegel lobe was then penetrated with a right angle dissector so that a plastic tape could be placed around the whole adhesion, including important structures in the hepatoduodenal ligament. Next, the right hepatic vein was transected with a vascular stapler using Pringle's maneuver using the plastic tape to fasten the entire adhesional structure. Subsequently, the trunk of the middle and left hepatic vein was transected after clamping. The remaining short hepatic veins in the left side were divided completely from the cranial to the caudal direction to dissect Spiegel's lobe. Finally, the hepatoduodenal ligament was identified from the attached remnant stomach and the duodenum and a vascular clamp was placed on the entire hepatoduaodenal ligament. Finally, the diseased liver was explanted for graft implantation. Thus, retrograde explantation of the liver was effective in decreasing the risk of damaging vital elements in the hepatoduodenal ligament, the remnant stomach, and the duodenum.

  3. 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

  4. 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.

  5. 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)

  6. 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.

  7. 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...

  8. 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...

  9. 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...

  10. 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

  11. Amebic Liver abscess Complicated by Inferior Vena Cava Thrombosis: A Case Report.

    Science.gov (United States)

    Ray, S; Khanra, D; Saha, M; Talukdar, A

    2012-10-01

    Amebic liver abscess is the most common extraintestinal manifestation of infection with Entamoeba histolytica. It is a common disease, especially in endemic areas, but it is a rare cause of inferior vena cava (IVC) obstruction, with only a few cases appearing in the literature. The authors describe a case of amebic liver abscess in a patient who developed a rare vascular complication of inferior vena cava thrombosis. The case responded to conservative treatment and radiological intervention.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    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...... phase opposition disposition" (APOD) modulation method used in traditional NPC topologies also has lower harmonics performance as compared to the "phase disposition" (PD) modulation method.In this paper, we introduce a new three-level NPC topology that utilises the harmonically superior PD modulation...

  20. Novel Full-bridge ZVS DC-DC Converter with an Clamp Diodes

    Science.gov (United States)

    Guangqun, Nan; Xue, Hu

    The two arms of this converter all work at zero-voltage switching condition, that bring many advantages, such as little loss of power, simple control, etc. But these also exists some problems, such as parasitic oscillation on the output rectifier diodes. A novel full-bridge ZVS PWM DC-DC converter which adopts two clamping diodes in the first side of the transformer is proposed to reduce the parasitic oscillation in this paper. In this paper, It heavily analyzes the realization process of their soft-switching and the reason of related issues and solution, we establishes simulation model and simulates using orCAD. Finally,a 5 kW ZVS PWM DC-DC converter Prototype in that TMS320F2812 is the core controlled chip has been set up, and the experiments showed us the validation of the correlative theory.

  1. 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

  2. Force-clamp analysis techniques reveal stretched exponential unfolding kinetics in ubiquitin

    CERN Document Server

    Lannon, Herbert; Brujic, Jasna

    2012-01-01

    Force-clamp spectroscopy reveals the unfolding and disulfide bond rupture times of single protein molecules as a function of the stretching force, point mutations and solvent conditions. The statistics of these times reveal whether the protein domains are independent of one another, the mechanical hierarchy in the polyprotein chain, and the functional form of the probability distribution from which they originate. It is therefore important to use robust statistical tests to decipher the correct theoretical model underlying the process. Here we develop multiple techniques to compare the well-established experimental data set on ubiquitin with existing theoretical models as a case study. We show that robustness against filtering, agreement with a maximum likelihood function that takes into account experimental artifacts, the Kuiper statistic test and alignment with synthetic data all identify the Weibull or stretched exponential distribution as the best fitting model. Our results are inconsistent with recently ...

  3. 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.

  4. SIMPLIFIED SVPWM ALGORITHM BASED DIODE CLAMPED 3-LEVEL INVERTER FED DTC-IM DRIVE

    Directory of Open Access Journals (Sweden)

    C. HARI KRISHNA

    2012-05-01

    Full Text Available This paper presents a simplified space vector pulse width modulation (SVPWM based diode clamped threelevel inverter fed direct torque controlled (DTC induction motor drive. The space vector diagram of three-level inverter is simplified into two-level inverter. So the selection of switching sequences is done as conventional two-level SVPWM method. Thus, the proposed algorithm reduces the complexity involved in the PWM algorithm. To validate the proposed PWM lgorithm, several simulation studies have been carried and resultsare presented. From the results, it can be observed that the proposed algorithm reduces the total harmonic distortion (THD of the line current and line voltages when compared with the 2-level inverter fed induction motor drive.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Cyclic peptide inhibitors of the β-sliding clamp in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Kjelstrup, Susanne; Hansen, Paula Melo Paulon; Thomsen, Line Elnif;

    2013-01-01

    Interaction between pairs of Staphylococcus aureus replication proteins was detected in an Escherichia coli based two-hybrid analysis. A reverse two-hybrid system was constructed for selection of compounds that hindered interaction between interacting protein pairs. A number of cyclic peptides......, from a library generated by the split intein-mediated circular ligation of peptides and proteins technology, were found to interfere with dimerization of the β-sliding clamp of the replisome. Two 8-mer peptides were analyzed in more detail. Both inhibited DNA replication, led to SOS induction, altered...... cell morphology and cell death. The peptides were active when added to bacterial cultures indicating that they could traverse the bacterial membrane to find their intracellular target. Peptide specificity was confirmed by overproduction of the putative target (DnaN) which resulted in resistance...

  10. 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.

  11. 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.

  12. 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...

  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. 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)

  15. Agenesia de vena cava inferior en un caso de autopsia forense Absence of the inferior cava vein in a case of forensic autopsy

    Directory of Open Access Journals (Sweden)

    M. Subirana Domènech

    2011-06-01

    Full Text Available La agenesia de vena cava inferior es una entidad congénita poco frecuente que a menudo se asocia con otras severas anomalías congénitas o malposiciones viscerales. También ha sido descrita como un factor de riesgo de trombosis venosa en pacientes jóvenes. La mayoría de los casos publicados proceden de estudios radiológicos y muy raramente aparece como hallazgo necrópsico. Presentamos un caso de agenesia de vena cava inferior, sin otras anomalías asociadas, que apareció como hallazgo incidental en una autopsia forense.The absence of the inferior vena cava is a rare congenital anomaly, often associated with severe congenital deformities and visceral position abnormalities. It has been described also as a risk factor for deep vein thrombosis in young patients. We present a case of congenital absence of inferior vena cava appeared as an incidental finding in a forensic autopsy.

  16. 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.

  17. Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage Source Inverter

    Directory of Open Access Journals (Sweden)

    Zulkifilie Bin Ibrahim

    2014-07-01

    Full Text Available Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM and Space Vector Pulse Width Modulation (SVPWM.  SPWM is the most simple modulation technique that can realize easily in analog circuit.  However, it has some drawbacks such as higher total harmonic distortion (THD, lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results are compared with conventional sinusoidal pulse width modulation (SPWM where SVPWM shows better performance than SPWM in terms of THD.

  18. 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.)

  19. 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.

  20. Characterization of ryanodine receptor type 1 single channel activity using "on-nucleus" patch clamp.

    Science.gov (United States)

    Wagner, Larry E; Groom, Linda A; Dirksen, Robert T; Yule, David I

    2014-08-01

    In this study, we provide the first description of the biophysical and pharmacological properties of ryanodine receptor type 1 (RyR1) expressed in a native membrane using the on-nucleus configuration of the patch clamp technique. A stable cell line expressing rabbit RyR1 was established (HEK-RyR1) using the FLP-in 293 cell system. In contrast to untransfected cells, RyR1 expression was readily demonstrated by immunoblotting and immunocytochemistry in HEK-RyR1 cells. In addition, the RyR1 agonists 4-CMC and caffeine activated Ca(2+) release that was inhibited by high concentrations of ryanodine. On nucleus patch clamp was performed in nuclei prepared from HEK-RyR1 cells. Raising the [Ca(2+)] in the patch pipette resulted in the appearance of a large conductance cation channel with well resolved kinetics and the absence of prominent subconductance states. Current versus voltage relationships were ohmic and revealed a chord conductance of ∼750pS or 450pS in symmetrical 250mM KCl or CsCl, respectively. The channel activity was markedly enhanced by caffeine and exposure to ryanodine resulted in the appearance of a subconductance state with a conductance ∼40% of the full channel opening with a Po near unity. In total, these properties are entirely consistent with RyR1 channel activity. Exposure of RyR1 channels to cyclic ADP ribose (cADPr), nicotinic acid adenine dinucleotide phosphate (NAADP) or dantrolene did not alter the single channel activity stimulated by Ca(2+), and thus, it is unlikely these molecules directly modulate RyR1 channel activity. In summary, we describe an experimental platform to monitor the single channel properties of RyR channels. We envision that this system will be influential in characterizing disease-associated RyR mutations and the molecular determinants of RyR channel modulation.

  1. A clamp fixture with interdigital capacitive sensor for in situ evaluation of wire insulation

    Science.gov (United States)

    Sheldon, Robert T.; Bowler, Nicola

    2014-02-01

    An interdigital capacitive sensor has been designed and optimized for testing aircraft wires by applying a quasinumerical model developed and reported previously. The sensor consists of two patches of interdigitated electrodes, connected by a long signal bus strip, that are intended to conform to two sides of an insulated wire. The electrodes are deposited using photolithography upon a 25.4-μm-thick Kapton® polyimide film. The two electrode patches are attached to the two jaws of a plastic spring-loaded clamp, with each jaw having a milled groove designed such that the electrodes conform to the curved surface of the insulated wire. An SMA connector and cable connect between the electrodes on the clamp and an LCR meter. Segments of pristine M5086/2 aircraft wire, each 10 cm long, were immersed in fluids commonly found in aircraft environments, to cause accelerated chemical degradation. The effects of Jet A fuel, deicing fluid, hydraulic fluid, aircraft cleaner, isopropyl alcohol and distilled water were studied. The frequency-dependent capacitance and dissipation factor of one pristine wire segment and of those degraded in the six fluid environments were measured within the frequency range 100 Hz to 1 MHz. Significant changes in capacitance and dissipation factor were observed for all degraded wires, compared with results for the pristine sample, suggesting the feasibility of detecting insulation degradation in the field. The results were also consistent with those of a similar experiment performed on sheets of Nylon 6, the material that comprises the outermost layer of M5086/2 wire.

  2. Estudo clínico e ultraestrutural pós-turbinectomia inferior parcial Clinical and ultrastructural study after partial inferior turbinectomy

    Directory of Open Access Journals (Sweden)

    Rogério Dutra Bandos

    2006-10-01

    Full Text Available O presente trabalho refere-se ao estudo dos resultados clínicos e histológicos obtidos após a turbinectomia inferior parcial (TIP, cirurgia indicada no tratamento da obstrução nasal crônica causada pela hipertrofia das conchas nasais inferiores. MATERIAL E MÉTODOS: Foram estudados vinte pacientes, divididos em dois grupos de dez cada (grupos A e B, submetidos à TIP, associada à septoplastia ou não. Os pacientes foram reavaliados clinicamente e histologicamente (com biópsia das áreas regeneradas das conchas inferiores, em dois períodos pós-operatórios diferentes: um grupo após oito a doze meses (grupo A e outro após dois anos de TIP (grupo B. RESULTADOS: Os resultados clínicos mostraram-se satisfatórios para o alívio da obstrução nasal no grupo A, e insatisfatórios no grupo B. Entretanto, melhores resultados histológicos, com maior recuperação e diferenciação epitelial da mucosa regenerada das conchas inferiores após a TIP foram observados no grupo B, com sua ultraestrutura ciliar normal. CONCLUSÕES: A cirurgia revelou ser eficaz a curto, mas não em médio prazo, apesar da recuperação histológica ter sido importante.We report clinical and histological results obtained after partial inferior turbinectomy (PIT, surgery indicated for the treatment of chronic nasal obstruction. METHODS: Twenty patients were divided into two groups submitted to PIT plus septoplasty and PIT alone. The patients were reassessed clinically and histologically by means of a biopsy of the regenerated areas in the inferior turbinates at two different times after PIT, i.e., after 8 to 12 months (group A and after two years (group B. RESULTS: The clinical results proved to be satisfactory for the relief of nasal obstruction in group A and unsatisfactory in group B. However, better histological results with better recovery and epithelial differentiation of the regenerated mucosa of the inferior turbinates after PIT were observed in group B

  3. 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

  4. The Circuit-Level Decoupling Modulation Strategy for Three-Level Neutral-Point-Clamped (TL-NPC) Inverter

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2011-01-01

    In this paper, a circuit-level decoupling modulation strategy is proposed for the three-level (TL) neutral-point-clamped (NPC) inverters. With the proposed modulation scheme, the TL-NPC inverter can be decoupled into two three-level Buck converters in each defined operating section, which makes...... without any feedback control. The simulation results show the validity of theoretical analysis....

  5. 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...

  6. 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...

  7. Thermal and efficiency analysis of five-level multi-level clamped multilevel converter considering grid codes

    DEFF Research Database (Denmark)

    Ma, Ke; Muñoz-Aguilar, S.; Rodriguez, P.;

    2012-01-01

    In this paper a five-level Multi-Clamped Multilevel Converter (5L-MLC2) topology is analyzed based on a typical grid integration application for renewable energy generation system. The loss and thermal distribution of the power devices in different switching legs are investigated and illustrated...

  8. 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

  9. 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.

  10. 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.

  11. Single-Carrier Modulation for Neutral-Point-Clamped Inverters in Three-Phase Transformerless Photovoltaic Systems

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Cavalcanti, Marcelo C.; Farias, Alexandre M.;

    2013-01-01

    Modulation strategy is one of the most important issues for three-level neutral-point-clamped inverters in three-phase transformerless photovoltaic systems. A challenge for modulation is how to keep the common-mode voltages constant to reduce the leakage currents. A single-carrier modulation...

  12. 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.

  13. 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...

  14. 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

  15. Recommendations for implementation of clamping strength in SteenToets: Kennisontwikkeling t.b.v. SteenToets 2006 Onderdeel 1 Normaalkracht

    NARCIS (Netherlands)

    Peters, D.J.

    2007-01-01

    This report belongs to the research programme on unknown aspects of Block Revetment systems. The stability of block revetments under wave loading is presumed to benefit from clamping forces. In previous studies a physical model for clamping forces was developed and verified. The existing design and

  16. 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

  17. 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)

  18. Comparison of inferior myocardial defect between planar and SPECT image of {sup 123}I-metaiodobenzylguanidine cardiac scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hideki; Momose, Mitsuru; Kashikura, Kenichi; Matsumoto, Nobusuke; Saito, Katsumi; Asano, Ryuta; Hosoda, Saichi; Kusakabe, Kiyoko [Tokyo Women`s Medical Coll. (Japan)

    1995-02-01

    Discordant findings of inferior MIBG defect between SPECT and planar images were sometimes observed in the clinical studies. In this study, we compared inferior myocardial findings between planar and SPECT image of {sup 123}I-metaiodobenzyl-guanidine (MIBG) cardiac scintigraphy in 29 patients. All patients were estimated as normal in anterior accumulation of MIBG. The patients were divided into 3 groups according to the visual finding of inferior defect in the planar and SPECT image; normal group (normal inferior accumulation of MIBG both in the planar and SPECT image, N=10), discordance group (inferior MIBG defect was only observed in the SPECT image, but was not observed in the planar image, N=7), inferior defect group (inferior MIBG defect was observed both in the planar and SPECT image, N=12). Inferior/anterior count ratio of SPECT and planar image were 0.96{+-}0.11 vs. 0.97{+-}0.05 in normal group, 0.59{+-}0.21 vs. 0.99{+-}0.13 in discordance group, 0.46{+-}0.13 vs. 0.82{+-}0.04 in inferior defect group. Liver/heart count ratio was significantly higher in the discordance group (2.07{+-}0.49) than that in the normal (1.14{+-}0.15) and inferior defect group (1.45{+-}0.39). In phantom study, it has been reported that increased liver accumulation of MIBG causes artifactual inferior defect adjacent to the liver. These data indicate that increased liver/heart count ratio may cause artifactual inferior defect on MIBG SPECT image in the clinical studies. Planar image evaluation may be helpful to distinct the artifactual inferior defect on SPECT image. (author).

  19. 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.

  20. Inferior Oblique Muscle Weakening: Is It Possible to Quantify Its Effects on Horizontal Deviations?

    Directory of Open Access Journals (Sweden)

    Hande Taylan Sekeroglu

    2012-01-01

    Full Text Available Objective. To evaluate and quantify the effect of inferior oblique muscle weakening on horizontal deviations. Methods. The medical files of patients who had undergone an inferior oblique weakening as a single procedure were all reviewed. The main measures were the type of inferior oblique overaction (IOOA, pre- and postoperative amount of IOOA, and horizontal deviations in primary position. Results. The study was conducted with 66 patients (30 males, 36 females. The median age was 11 years (1–49. Of the 66 patients, 30 (45.5% had primary and 36 (54.5% had secondary IOOA. The most common procedure was inferior oblique anteriorization in 32 patients (48.5%. The mean postoperative horizontal and vertical deviations and the amount of IOOA were decreased postoperatively ( for all. The median amount of correction of horizontal near and distance deviations was (0–20. The preoperative amount of IOOA, the presence of fourth nerve palsy, and the type of the weakening procedure had no significant effect on the amount of correction of horizontal deviations. Conclusion. The inferior oblique weakening procedures have secondary effects and warrant reduction of horizontal deviations in varying degrees. This should be borne in mind in planning a simultaneous horizontal muscle surgery and setting the surgical amount.

  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. 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.

  3. 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.

  4. Growth in the area of the inferior dental foramen of rats.

    Science.gov (United States)

    Engel, G; West, V C

    1983-01-01

    The object of the present investigation was to see if the bone around the inferior dental nerve remodelled during mandibular growth and development. The investigation was carried out by injecting 27 albino Lewis rats with three fluorescent bone seeking dyes--oxytetracycline HCl (OTC), alizarin red S (ARS), and 2,4 bis-[N,N'-di' (carbomethyl-aminomethyl)] fluorescein (DCAF)--and then studying the bone around the inferior dental foramen. The mandibles of the animals were studied both macroscopically and microscopically under ultraviolet light to investigate the growth processes occurring and to see if the inferior dental foramen was relocated during growth. A quantitative analysis utilizing two specimens was also carried out for the same purpose. The results of both the qualitative and the quantitative analyses showed that the bone around the inferior dental nerve remodeled during mandibular growth. The mandible grew in an upward and backward direction, and the inferior dental foramen was correspondingly relocated in an upward and backward direction to maintain exactly the same position relative to the condyle and the posterior border of the ramus. This study, then, supports Moss's concept of the "unloaded" nerve, and is in keeping with his view of mandibular growth based on the functional matrix theory.

  5. 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.

  6. 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

  7. Importance of human right inferior frontoparietal network connected by inferior branch of superior longitudinal fasciculus tract in corporeal awareness of kinesthetic illusory movement.

    Science.gov (United States)

    Amemiya, Kaoru; Naito, Eiichi

    2016-05-01

    It is generally believed that the human right cerebral hemisphere plays a dominant role in corporeal awareness, which is highly associated with conscious experience of the physical self. Prompted by our previous findings, we examined whether the right frontoparietal activations often observed when people experience kinesthetic illusory limb movement are supported by a large-scale brain network connected by a specific branch of the superior longitudinal fasciculus fiber tracts (SLF I, II, and III). We scanned brain activity with functional magnetic resonance imaging (MRI) while nineteen blindfolded healthy volunteers experienced illusory movement of the right stationary hand elicited by tendon vibration, which was replicated after the scanning. We also scanned brain activity when they executed and imagined right hand movement, and identified the active brain regions during illusion, execution, and imagery in relation to the SLF fiber tracts. We found that illusion predominantly activated the right inferior frontoparietal regions connected by SLF III, which were not substantially recruited during execution and imagery. Among these regions, activities in the right inferior parietal cortices and inferior frontal cortices showed right-side dominance and correlated well with the amount of illusion (kinesthetic illusory awareness) experienced by the participants. The results illustrated the predominant involvement of the right inferior frontoparietal network connected by SLF III when people recognize postural changes of their limb. We assume that the network bears a series of functions, specifically, monitoring the current status of the musculoskeletal system, and building-up and updating our postural model (body schema), which could be a basis for the conscious experience of the physical self.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. [Several common types of counterfeit and inferior drugs in Chinese medicinal materials market].

    Science.gov (United States)

    Liu, Yimei; Chen, Keli

    2012-04-01

    Though there are many species of counterfeit and inferior drugs of Chinese Medicinal Materials in the market, the means of fabrication is common. According to our investigating and reports in the literature it is found that the counterfeits and inferior drugs exist in 4 styles: counterfeits, reused medicinal materials and their slices which have been extracted by boiling water or ethanol, medicinal materials and their slices which have been added with non-medicinal parts or chemicals, medicinal materials which have no enough growth time or have been reserved for a long time. Through summarizing the styles and their common characteristics of the counterfeits and inferior drugs,it is helpful to raise vigilance and detect them.

  13. 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

  14. Acute inferior myocardial infarction with right ventricular infarction is more prone to develop cardiogenic shock.

    Science.gov (United States)

    Bari, M A; Roy, A K; Islam, M Z; Aditya, G; Bhuiyan, A S

    2015-01-01

    Cardiogenic shock is rare in isolated acute inferior myocardial infarction but there is relationship of cardiogenic shock with inferior myocardial infarction if associated with right ventricular infarction. A prospective study was carried out to see the association of cardiogenic shock with inferior myocardial infarction if associated with right ventricular infarction. This study was conducted from January 2011 to November 2011. A total of 100 cases were selected as study population which was taken from the Department of Cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh. Among them 50 were in Group A and 50 were in Group B. Group A was the patients of acute myocardial infarction with right ventricular infarction. Group B was the patients of acute myocardial infarction without right ventricular infarction. It revealed that 9(18%) in Group A and 3(6%) in Group B developed cardiogenic shock which is statistically significant (pcardiogenic shock.

  15. 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)

  16. Planar patch clamp approach to characterize ionic currents from intact lysosomes.

    Science.gov (United States)

    Schieder, Michael; Rötzer, Katrin; Brüggemann, Andrea; Biel, Martin; Wahl-Schott, Christian

    2010-01-01

    Since its launch in the early 1980s, the patch clamp method has been extensively used to study ion channels in the plasma membrane, but its application to the study of intracellular ion channels has been limited. Unlike the plasma membrane, intracellular membranes are usually not stable enough to withstand mechanical manipulation by glass electrodes during seal formation and rupturing of the membrane. To circumvent these problems, we developed a method involving the immobilization of isolated organelles on a solid matrix planar glass chip. This glass chip contains a microstructured hole that supports the formation of gigaseals and subsequent electrophysiological recordings despite the high fragility of intracellular membranes. Here, we report the experimental details of this method using lysosomes, which are the smallest cellular organelles, as a model system. We demonstrate that we can record endogenous ionic currents from wild-type lysosomes, as well as from lysosomes overexpressing ion channels, and expect that this method will provide electrophysiological access to a broad range of intracellular ion channels.

  17. 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.

  18. The Dynamics of a Doubly Clamped Microbeam Near the Primary Resonance: Experimental and Analytical Investigation

    KAUST Repository

    Masri, Karim M.

    2016-01-20

    We present experimental and analytical investigation of the dynamics of a doubly clamped microbeam near its primary resonance. The microbeam is excited electrostatically by an electrode on the first half of the beam. These microbeams are fabricated using polyimide as structural layer coated with nickel from top and chromium and gold layers from bottom. A noise signal is applied to experimentally detect the natural frequencies. Then, frequency sweep tests are generated for various values of DC bias revealing hardening, transition, and softening behavior of the microbeam. We report for the first time the transition from lower stable state, to unstable state, and then to large stable state experimentally. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. Shooting method is used to find the periodic motion and is utilized to generate frequency response curves. The curves show good agreement with the experimental results with hardening behavior at lower DC voltage then softening at higher voltage loads and dynamic pull-in. © Copyright 2015 by ASME.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  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. Cyclic peptide inhibitors of the β-sliding clamp in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Susanne Kjelstrup

    Full Text Available Interaction between pairs of Staphylococcus aureus replication proteins was detected in an Escherichia coli based two-hybrid analysis. A reverse two-hybrid system was constructed for selection of compounds that hindered interaction between interacting protein pairs. A number of cyclic peptides, from a library generated by the split intein-mediated circular ligation of peptides and proteins technology, were found to interfere with dimerization of the β-sliding clamp of the replisome. Two 8-mer peptides were analyzed in more detail. Both inhibited DNA replication, led to SOS induction, altered cell morphology and cell death. The peptides were active when added to bacterial cultures indicating that they could traverse the bacterial membrane to find their intracellular target. Peptide specificity was confirmed by overproduction of the putative target (DnaN which resulted in resistance. The minimum inhibitory concentration was ∼50 μg/ml for S. aureus cells. These compounds may serve as lead candidates for future development into novel classes of antibiotics as well as provide information on the function of the S. aureus replication process.

  5. 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%.

  6. Inferior retinal light exposure is more effective than superior retinal exposure in suppressing melatonin in humans

    Science.gov (United States)

    Glickman, Gena; Hanifin, John P.; Rollag, Mark D.; Wang, Jenny; Cooper, Howard; Brainard, George C.

    2003-01-01

    Illumination of different areas of the human retina elicits differences in acute light-induced suppression of melatonin. The aim of this study was to compare changes in plasma melatonin levels when light exposures of equal illuminance and equal photon dose were administered to superior, inferior, and full retinal fields. Nine healthy subjects participated in the study. Plexiglass eye shields were modified to permit selective exposure of the superior and inferior halves of the retinas of each subject. The Humphrey Visual Field Analyzer was used both to confirm intact full visual fields and to quantify exposure of upper and lower visual fields. On study nights, eyes were dilated, and subjects were exposed to patternless white light for 90 min between 0200 and 0330 under five conditions: (1) full retinal exposure at 200 lux, (2) full retinal exposure at 100 lux, (3) inferior retinal exposure at 200 lux, (4) superior retinal exposure at 200 lux, and (5) a dark-exposed control. Plasma melatonin levels were determined by radioimmunoassay. ANOVA demonstrated a significant effect of exposure condition (F = 5.91, p exposures as well as the inferior retinal exposure; however, superior retinal exposure was significantly less effective in suppressing melatonin. Furthermore, suppression with superior retinal exposure was not significantly different from that of the dark control condition. The results indicate that the inferior retina contributes more to the light-induced suppression of melatonin than the superior retina at the photon dosages tested in this study. Findings suggest a greater sensitivity or denser distribution of photoreceptors in the inferior retina are involved in light detection for the retinohypothalamic tract of humans.

  7. 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

  8. INFERIOR TURBINECTOMY FOR NASAL OBSTRUCTION-STUDY O F 219 CASES

    Directory of Open Access Journals (Sweden)

    Santhosh

    2013-03-01

    Full Text Available ABSTRACT: OBJECTIVE : To determine the success rate of inferior turbine ctomy for nasal obstruction. To study complications of inferior turb inectomy. To study the histopathological changes in the inferior turbinate specimens. METHOD : This prospective, single blinded, randomized study of 219 consecutive patients carried out in two tertiary le vel centres from January 2010 to October 2011. The patients were asse ssed preoperatively and postoperatively both subjectively and objectively. The patients who were refractory to the directed conservative treatment for chronic nasal obstruction underwent i nferior turbinectomy on both sides and septoplasty if required. The inferior turbinectomy spe cimen was sent for histopathological examination. NOSE Questionnaires were used for subj ective assessment and rigid nasal endoscopy used for objective assessment. Follow up do ne at 1 week, 1 month and 6 months after surgery. Friedman test applied for assessment o f the improvement. RESULTS : 92 % (n=203 of patients relieved of nasal obstruction fo r which they approached. The improvement is statistically significant both subjectively and objectively. The common complications in present study is postoperative nasal synechia which o ccurred in 5% (n=10. Bleeding occurred in 4%(n=8. Dryness and crusting occurred in 2%(n=4 and foul odour in 2% (n=4. The present study also showed that most common cause for turbinate enlargement is chronic nonspecific inflammatory hypertrophy followed by aller gic turbinate hypertrophy. CONCLUSION : -The results show that inferior turbinectomy is t he good method of achieving relief from the nasal obstruction with minimal morb idity. Histopathological examination showed that most common cause of turbinate enlargem ent is chronic non specific turbinate hypertrophy and it proves beyond doubt that unnecessa ry excessive antiallergic treatment should be avoided in patients with chronic nasal obs truction KEY WORDS: inferior

  9. 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.

  10. 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 ...

  11. 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.

  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. Involvement of the right inferior longitudinal fascicle in visual hemiagnosia: a brain stimulation mapping study.

    Science.gov (United States)

    Fernández Coello, Alejandro; Duvaux, Sophie; De Benedictis, Alessandro; Matsuda, Ryosuke; Duffau, Hugues

    2013-01-01

    Neural foundations underlying visual agnosia are poorly understood. The authors present the case of a patient who underwent awake surgery for a right basal temporooccipital low-grade glioma in which direct electrostimulation was used both at the cortical and subcortical level. Brain mapping over the inferior longitudinal fascicle generated contralateral visual hemiagnosia. These original findings are in agreement with recent tractography data that have confirmed the existence of an occipitotemporal pathway connecting occipital visual input to higher-level processing in temporal lobe structures. This is the first report of a true transient visual hemiagnosia elicited through electrostimulation, supporting the crucial role of inferior longitudinal fascicle in visual recognition.

  14. 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

  15. 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

  16. 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.

  17. Enhanced static ground power unit based on flying capacitor based h-bridge hybrid active-neutral-point-clamped converter

    DEFF Research Database (Denmark)

    Abarzadeh, Mostafa; Madadi Kojabadi, Hossein; Deng, Fujin;

    2016-01-01

    Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages of the p......Static power converters have various applications, such as static ground power units (GPUs) for airplanes. This study proposes a new configuration of a static GPU based on a novel nine-level flying capacitor h-bridge active-neutral-point-clamped (FCHB_ANPC) converter. The main advantages...... of the proposed converter in comparison with conventional nine-level ANPC converter are decreasing the number of switches and flying capacitors (FCs) in the proposed converter, doubling the output voltage level of a traditional ANPC converter and reduction of output L-C filter sizes which results in significant...

  18. 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.

  19. 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.

  20. 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;

    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...... a maximum number of output voltage levels by preserving the adjacent switching vectors between voltage levels. Hence, a 15-level hybrid converter can be attained with a minimum number of power components. A comparative study has been carried out to present high performance of the proposed configuration...... 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 inverter...

  1. 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.

  2. 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.

  3. 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.

  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. 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.

  6. 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.

  7. 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...

  8. 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...

  9. Off-Clamp Laparoscopic Partial Nephrectomy for a Fat-Poor Angiomyolipoma Arising from the Renal Capsule: A Case Report

    Directory of Open Access Journals (Sweden)

    Koichi Kodama

    2012-01-01

    Full Text Available Renal function can be significantly preserved after nephron-sparing surgery by decreasing the intraoperative ischemic duration or by performing off-clamp surgery. We report the case of a 56-year-old woman diagnosed with a minimal-fat angiomyolipoma arising from the renal capsule, which was successfully treated by retroperitoneoscopic partial nephrectomy without hilar clamping. Computed tomography revealed a 16 × 13 mm homogenous lenticular mass protruding from the lateral aspect of the left kidney. On both T1- and T2-weighted magnetic resonance images, the mass exhibited homogenous low-signal intensity and well-defined margins. Laparoscopic magnification indicated that the exophytic tumor was attached to the renal cortex by a small peduncle. The tumor was resected completely with negative surgical margin. The estimated glomerular filtration rate after surgery was nearly equal to that before surgery. Off-clamp laparoscopic partial nephrectomy is a feasible surgical option to prevent ischemic renal damage in select patients presenting with small, exophytic, and peripheral renal masses.

  10. Time-domain simulation of channel crosstalk and inter-modulation distortion in gain-clamped semiconductor optical amplifiers

    Science.gov (United States)

    Li, Xun; Park, Jongwoon

    2006-07-01

    A time-domain model is implemented for gain-clamped semiconductor optical amplifiers (GC-SOAs) based on a combination of the separated traveling-wave equations and effective Bloch equations. The key feature of this model lies in its capability of handling the lasing-signal, signal-signal, and signal-noise interactions over a broad wavelength band. Therefore, various nonlinear phenomena such as the cross-gain saturation (XGS) and nondegenerate four-wave mixing (ND-FWM) can readily be captured. After being implemented and validated, this model is applied to the simulation of GC-SOA dynamic behaviors such as the channel crosstalk and intermodulation distortion (IMD). Simulation results show that the third-order IMD can be effectively suppressed by a gain-clamping lasing mode in GC-SOAs in comparison with that in conventional SOAs. The channel crosstalk can also be suppressed to some extent in GC-SOAs, but not as effectively. Other than a homogeneous reduction, the gain-clamping in GC-SOAs does not change the dependence of the channel crosstalk and IMD on the input signal power and channel spacing. It is also shown that the channel crosstalk, unlike the IMD, cannot be efficiently reduced by enlarging the channel spacing even in GC-SOAs.

  11. Analysis of failed and nickel-coated 3093 beam clamp components at the East Tennessee Technology Park (ETTP).

    Energy Technology Data Exchange (ETDEWEB)

    Singh, D.; Pappacena, K.; Gaviria, J.; Burtsteva, T.; Nuclear Engineering Division

    2010-10-11

    The U.S. Department of Energy and its contractor, Bechtel Jacobs Company (BJC), are undertaking a major effort to clean up the former gaseous diffusion facility (K-25) located in Oak Ridge, TN. The decontamination and decommissioning activities require systematic removal of contaminated equipment and machinery followed by demolition of the buildings. As part of the cleanup activities, a beam clamp, used for horizontal life lines (HLLs) for fall protection, was discovered to be fractured during routine inspection. The beam clamp (yoke and D-ring) was a component in the HLL system purchased from Reliance Industries LLC. Specifically, the U-shaped stainless steel yoke of the beam clamp failed in a brittle mode at under less than 10% of the rated design capacity of 14,500 lb. The beam clamp had been in service for approximately 16 months. Bechtel Jacobs approached Argonne National Laboratory to assist in identifying the root cause of the failure of the beam clamp. The objectives of this study were to (1) review the prior reports and documents on the subject, (2) understand the possible failure mechanism(s) that resulted in the failed beam clamp components, (3) recommend approaches to mitigate the failure mechanism(s), and (4) evaluate the modified beam clamp assemblies. Energy dispersive x-ray analysis and chemical analysis of the corrosion products on the failed yoke and white residue on an in-service yoke indicated the presence of zinc, sulfur, and calcium. Analysis of rainwater in the complex, as conducted by BJC, indicated the presence of sulfur and calcium. It was concluded that, as a result of galvanic corrosion, zinc from the galvanized components of the beam clamp assembly (D-ring) migrated to the corroded region in the presence of the rainwater. Under mechanical stress, the corrosion process would have accelerated, resulting in the catastrophic failure of the yoke. As suggested by Bechtel Jacobs personnel, hydrogen embrittlement as a consequence of corrosion

  12. TFE and Spt4/5 open and close the RNA polymerase clamp during the transcription cycle.

    Science.gov (United States)

    Schulz, Sarah; Gietl, Andreas; Smollett, Katherine; Tinnefeld, Philip; Werner, Finn; Grohmann, Dina

    2016-03-29

    Transcription is an intrinsically dynamic process and requires the coordinated interplay of RNA polymerases (RNAPs) with nucleic acids and transcription factors. Classical structural biology techniques have revealed detailed snapshots of a subset of conformational states of the RNAP as they exist in crystals. A detailed view of the conformational space sampled by the RNAP and the molecular mechanisms of the basal transcription factors E (TFE) and Spt4/5 through conformational constraints has remained elusive. We monitored the conformational changes of the flexible clamp of the RNAP by combining a fluorescently labeled recombinant 12-subunit RNAP system with single-molecule FRET measurements. We measured and compared the distances across the DNA binding channel of the archaeal RNAP. Our results show that the transition of the closed to the open initiation complex, which occurs concomitant with DNA melting, is coordinated with an opening of the RNAP clamp that is stimulated by TFE. We show that the clamp in elongation complexes is modulated by the nontemplate strand and by the processivity factor Spt4/5, both of which stimulate transcription processivity. Taken together, our results reveal an intricate network of interactions within transcription complexes between RNAP, transcription factors, and nucleic acids that allosterically modulate the RNAP during the transcription cycle.

  13. 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

  14. Inferior fronto-temporo-occipital connectivity: a missing link between maltreated girls and neglectful mothers.

    Science.gov (United States)

    Rodrigo, María José; León, Inmaculada; Góngora, Daylin; Hernández-Cabrera, Juan A; Byrne, Sonia; Bobes, María A

    2016-10-01

    The neurobiological alterations resulting from adverse childhood experiences that subsequently may lead to neglectful mothering are poorly understood. Maternal neglect of an infant's basic needs is the most prevalent type of child maltreatment. We tested white matter alterations in neglectful mothers, the majority of whom had also suffered maltreatment in their childhood, and compared them to a matched control group. The two groups were discriminated by a structural brain connectivity pattern comprising inferior fronto-temporo-occipital connectivity, which constitutes a major portion of the face-processing network and was indexed by fewer streamlines in neglectful mothers. Mediation and regression analyses showed that fewer streamlines in the right inferior longitudinal fasciculus tract (ILF-R) predicted a poorer quality of mother-child emotional availability observed during cooperative play and that effect depended on the respective interactions with left and right inferior fronto-occipital fasciculi (IFO-R/L), with no significant impact of psychopathological and cognitive conditions. Volume alteration in ILF-R but not in IFO-L modulated the impact of having been maltreated on emotional availability. The findings suggest the altered inferior fronto-temporal-occipital connectivity, affecting emotional visual processing, as a possible common neurological substrate linking a history of childhood maltreatment with maternal neglect.

  15. Prominence vs. Aboutness in Sequencing: A Functional Distinction within the Left Inferior Frontal Gyrus

    Science.gov (United States)

    Bornkessel-Schlesewsky, Ina; Grewe, Tanja; Schlesewsky, Matthias

    2012-01-01

    Prior research on the neural bases of syntactic comprehension suggests that activation in the left inferior frontal gyrus (lIFG) correlates with the processing of word order variations. However, there are inconsistencies with respect to the specific subregion within the IFG that is implicated by these findings: the pars opercularis or the pars…

  16. Inferior fronto-temporo-occipital connectivity: a missing link between maltreated girls and neglectful mothers.

    Science.gov (United States)

    Rodrigo, María José; León, Inmaculada; Góngora, Daylin; Hernández-Cabrera, Juan A; Byrne, Sonia; Bobes, María A

    2016-10-01

    The neurobiological alterations resulting from adverse childhood experiences that subsequently may lead to neglectful mothering are poorly understood. Maternal neglect of an infant's basic needs is the most prevalent type of child maltreatment. We tested white matter alterations in neglectful mothers, the majority of whom had also suffered maltreatment in their childhood, and compared them to a matched control group. The two groups were discriminated by a structural brain connectivity pattern comprising inferior fronto-temporo-occipital connectivity, which constitutes a major portion of the face-processing network and was indexed by fewer streamlines in neglectful mothers. Mediation and regression analyses showed that fewer streamlines in the right inferior longitudinal fasciculus tract (ILF-R) predicted a poorer quality of mother-child emotional availability observed during cooperative play and that effect depended on the respective interactions with left and right inferior fronto-occipital fasciculi (IFO-R/L), with no significant impact of psychopathological and cognitive conditions. Volume alteration in ILF-R but not in IFO-L modulated the impact of having been maltreated on emotional availability. The findings suggest the altered inferior fronto-temporal-occipital connectivity, affecting emotional visual processing, as a possible common neurological substrate linking a history of childhood maltreatment with maternal neglect. PMID:27342834

  17. Diffusion tensor imaging of the inferior colliculus and brainstem auditory-evoked potentials in preterm infants

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, Milla; Lehtonen, Liisa; Lapinleimu, Helena [Turku University Central Hospital, Department of Paediatrics, Turku (Finland); Parkkola, Riitta [Turku University Central Hospital, Department of Radiology and Turku PET Centre, Turku (Finland); Johansson, Reijo [Turku University Central Hospital, Department of Otorhinolaryngology, Turku (Finland); Jaeaeskelaeinen, Satu K. [Turku University Central Hospital, Department of Clinical Neurophysiology, Turku (Finland); Kujari, Harry [Turku University Central Hospital, Department of Pathology, Turku (Finland); Haataja, Leena [Turku University Central Hospital, Department of Paediatric Neurology, Turku (Finland)

    2009-08-15

    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.)

  18. 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

  19. 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.

  20. 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 synch...

  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 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

  3. HISTOLOGICAL STUDIES OF THE EFFECTS OF MONOSODIUM GLUTAMATE ON THE INFERIOR COLLICULUS OF ADULT WISTAR RATS.

    Directory of Open Access Journals (Sweden)

    A.O. Eweka.

    2008-01-01

    Full Text Available Histological effects of Monosodium glutamate (MSG commonly used as food additive on the inferior colliculus (IC of adult Wistar rats were carefully studied. The rats of both sexes (n=24, average weight of 185g were randomly assigned into two treatments (n=16 and control (n=8 groups. The rats in the treatment groups received 3g and 6g of MSG thoroughly mixed with their feeds for fourteen days, while the control rats received equal amounts of feeds without MSG added. The rats were fed with growers' mash purchased from Edo Feeds and Flour Mill Ltd, Ewu, Edo State and were given water liberally. The rats were sacrificed on day fifteen of the experiment. The inferior colliculus was carefully dissected out and quickly fixed in 10% formal saline for routine histological study after H&E method.The histological findings after H&E methods indicated that the treated sections of the inferior colliculus showed some cellular degenerative changes, cellular hypertrophy, and autophagic vacuoles with some intercellular vacuolations appearing in the stroma, and some degree of neuronal hypertrophy when compared to the control sections.These findings indicate that MSG consumption may have a deleterious effect on the neurons of the inferior colliculus (IC. MSG may probably have adverse effects on the auditory sensibilities by its deleterious effects on the nerve cells of the IC of adult Wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out.

  4. 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…

  5. 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.

  6. 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.

  7. 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

  8. 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.)

  9. 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.

  10. 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

  11. Permutation test for non-inferiority of the linear to the optimal combination of multiple tests.

    Science.gov (United States)

    Jin, Hua; Lu, Ying

    2009-03-01

    We proposed a permutation test for non-inferiority of the linear discriminant function to the optimal combination of multiple tests based on Mann-Whitney statistic estimate of the area under the receiver operating characteristic curve. Monte Carlo simulations showed its good performance.

  12. Left Inferior Frontal Cortex and Syntax: Function, Structure and Behaviour in Patients with Left Hemisphere Damage

    Science.gov (United States)

    Tyler, Lorraine K.; Marslen-Wilson, William D.; Randall, Billi; Wright, Paul; Devereux, Barry J.; Zhuang, Jie; Papoutsi, Marina; Stamatakis, Emmanuel A.

    2011-01-01

    For the past 150 years, neurobiological models of language have debated the role of key brain regions in language function. One consistently debated set of issues concern the role of the left inferior frontal gyrus in syntactic processing. Here we combine measures of functional activity, grey matter integrity and performance in patients with left…

  13. 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

  14. 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.

  15. 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

  16. 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)

  17. Inferior oblique weakening surgery on ocular torsion in congenital superior oblique palsy

    Institute of Scientific and Technical Information of China (English)

    Jinho; Lee; Soh-Youn; Suh; Ho-Kyung; Choung; Seong-Joon; Kim

    2015-01-01

    AIM: To investigate changes in fundus excyclotorsion after inferior oblique myectomy or myotomy. METHODS: The records of 21 patients undergoing strabismus surgery by a single surgeon between 2009 and 2012 were examined. Only patients who had undergone an inferior oblique myectomy or myotomy,with or without horizontal rectus muscle surgery, were evaluated. Digital fundus photographs were obtained,and the angle formed by a horizontal line passing through the optic disc center and a reference line connecting the foveola and optic disc center was measured. Associated clinical factors examined include age at the time of surgery, presence or absence of a head tilt, degree of preoperative vertical deviation,torsional angle, inferior oblique muscle overaction/superior oblique muscle underaction, and surgery laterality. Whether the procedure was performed alone or in combination with a horizontal rectus muscle surgery was also examined. RESULTS: Mean preoperative torsional angle was12. 0 ± 6. 4 °, which decreased to 6. 9 ± 5. 7 ° after surgery(P <0.001, paired t-test). Torsional angle also decreased from 15. 1 ± 7. 0 ° to 6. 2 ± 4. 3 ° in the myectomy group(P <0.001, paired t-test) but there were no significant changes in the myotomy group(P =0.093, Wilcoxon signed rank test). Multivariable linear regression analysis showed that preoperative torsional angle, degree ofinferior oblique overaction, and age at surgery independently and significantly affected postoperative torsional angle.CONCLUSION: Mean torsional angle decreased after inferior oblique myectomy. Degree of preoperative torsional angle, inferior oblique overaction, and age at surgery influence postoperative torsional angle.

  18. 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

  19. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J M; De Bruin, J. P.; Van Den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A M; Laven, J. S E; Van Der Linden, P. J Q; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    2016-01-01

    studyquestion: Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? summaryanswer: AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy rat

  20. 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.

  1. A RARE CASE OF EXTENSIVE THROMBOSIS OF INFERIOR VENA CAVA, PORTAL VEIN, SPLENIC VEIN AND SUPERIOR MESENTRIC VEIN

    Directory of Open Access Journals (Sweden)

    Giridhar

    2015-03-01

    Full Text Available While the most common presentation of venous thromboembolic disease is deep vein thrombosis (DVT or pulmonary thromboembolism, rarer manifestations are thrombosis of jugular vein, cerebral sinus and inferior vena cava. Here we are presenting a rare case of inferior vena caval thrombosis with multiple thrombus in portal vein, splenic vein and superior mesenteric vein

  2. 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...

  3. 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

  4. Aneurisma da artéria cerebelar ântero-inferior: relato de caso Aneurysm of the anterior inferior cerebellar artery: case report

    Directory of Open Access Journals (Sweden)

    Juan Oscar Alarcón Adorno

    2002-12-01

    Full Text Available Os aneurismas intracranianos do sistema vértebro-basilar representam cerca de 5 a 10% de todos os aneurismas cerebrais. Os aneurismas da artéria cerebelar ântero-inferior (AICA são considerados raros, podendo causar síndrome do ângulo ponto cerebelar, com ou sem hemorragia subaracnóidea. Desde 1948, foram descritos poucos casos na literatura. Apresentamos o caso de uma paciente, de 33 anos, na qual, após investigação de quadro de hemorragia subaracnóidea, diagnosticou-se aneurisma sacular da AICA esquerda. Foi submetida a clipagem do aneurisma, com ótimo resultado pós operatório.The intracranial aneurysms of the posterior circulation have been reported between 5 and 10% of all cerebral aneurysms and the aneurysms of the anterior inferior cerebellar artery (AICA are considered rare, can cause cerebello pontine angle (CPA syndrome with or without subarachnoid hemorrhage. Since 1948 few cases were described in the literature. We report on a 33 year-old female patient with subarachnoid hemorrhage due to sacular aneurysm of the left AICA. She was submitted to clipage of the aneurysm without complications.

  5. 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.

  6. Meta-analysis of thyroidectomy with ultrasonic dissector versus conventional clamp and tie

    Directory of Open Access Journals (Sweden)

    Sanguinetti Alessandro

    2010-12-01

    Full Text Available Abstract Background We conducted a systematic review to evaluate the role of Ultrasonic dissector (UAS versus conventional clamp and tie in thyroidectomy. Materials and methods We searched for all published RCT in into electronic databases. To be included in the analysis, the studies had to compare thyroidectomy with UAS versus conventional vessel ligation and tight (conventional technique = CT. The following outcomes were used to compare the total thyroidectomy group with UAS versus CT group: operative duration, operative blood loss, overall drainage volume during the first 24 hours, transiet laryngeal nerve palsy, permanent laryngeal nerve palsy, transiet hypocalcaemia and permanent hypocalcaemia. Results There are currently 7 RCT on this issue to compare thyroidectomy with UAS versus CT. From the analysis of these studies it was possible to confront 608 cases: 303 undergoing to thyroidectomy with UAS versus 305 that were treated with CT. Actually, it was shown a relevant advantage of cost-effectiveness in patients treated with UAS; there is a statistically significant reduction of the operative duration (weighted mean difference [WMD], -18.74 minutes; 95% confidence interval [CI], (-26.97 to -10.52 minutes (P = 0.00001, intraoperative blood loss (WMD, -60.10 mL; 95% CI, -117.04 to 3.16 mL (P = 0.04 and overall drainage volume (WMD, -35.30 mL; 95% CI, -49.24 to 21.36 mL (P = 0.00001 in the patients underwent thyroidectomy with UAS. Although the analysis showed that the patients who were treated with USA presented more favourable results in incidence of post-operative complications (transient laryngeal nerve palsy: P = 0.11; permanent laryngeal nerve palsy: not estimable; transient hypocalcaemia: P = 0.24; permanent hypocalcaemia: P = 0.45, these data didn't present statistical relevance. Conclusion This meta-analysis shown a relevant advantage only in terms of cost-effectiveness in patients treated with UAS; it is subsequent to statistically

  7. An Interpretation of Jane Eyre’s Feeling of Inferiority at Gateshead in Jane Eyre

    Institute of Scientific and Technical Information of China (English)

    赵艳梅

    2015-01-01

    Jane Eyre has been the focus of numerous critics and scholars since its publication in 1847 and they have made a great contribution to the study of Jane Eyre, exploring it from different perspectives. Most of critics and readers regard Jane Eyre as an independent and brave feminism fighter to challenge the tradition in Victorian period while they tend to pay less attention to the invisible side of Jane Eyre. Jane Eyre is not always so brave and strong and confident to face her life, which can be discovered from her language and behavior when she confronts conflicts. This is Jane Eyre ’s feeling of inferiority. From the perspective of Alfred Adler’s individual psychology, this thesis studies Jane Eyre’s feeling of inferiority at Gateshead.

  8. Subacute sclerosing panencephalitis with bilateral inferior collicular hyperintensity on magnetic resonance imaging brain

    Directory of Open Access Journals (Sweden)

    Maya Thomas

    2012-01-01

    Full Text Available Subacute sclerosing panencephalitis (SSPE is chronic encephalitis occurring after infection with measles virus. An 8-year-old boy presented with progressive behavioral changes, cognitive decline and myoclonic jerks, progressing to a bed bound state over 2 months. Magnetic resonance imaging (MRI brain showed T2-weighted hyperintensities in the subcortical areas of the left occipital lobe and brachium of the inferior colliculus on both sides. EEG showed bilateral, synchronous periodic discharges. Serum/cerebrospinal fluid measles IgG titer was significantly positive. The overall features were suggestive of SSPE. MRI finding of bilateral inferior colliculus changes on MRI without significant involvement of other commonly involved areas suggests an uncommon/rare imaging pattern of SSPE.

  9. Agenesis of Ductus Venosus Presenting with Dilated Inferior Vena Cava with Favorable Outcome

    Directory of Open Access Journals (Sweden)

    Omer Dai

    2014-04-01

    Full Text Available The ductus venosus regulates the distribution of oxygen and placental nutrients by restricting the centralization of blood flow in fetal circulation. The ductus venosus is a small vein transmitting oxygen-rich blood from the umbilical vein to the fetal heart.. Increasing numbers of case reports are being published about ductus venosus agenesis with cardiac structural abnormalities, other malformations, chromosomal abnormalities, and stillbirth. Heart failure, hydrops and unexplained polyhydramnios could also be associated with ductus venosus agenesis. In the follow-up of fetuses with ductus venosus agenesis, care must be taken to examine for hydrops and heart failure. The agenesis of ductus venosus is often only found in fetuses by coincidentally. Herein we discuss the prenatal diagnosis of isolated agenesis of the ductus venosus presenting with a dilated inferior vena cava and without any disturbance of fetal hemodynamics and any other malformation. In conclusion a dilated inferior vena cava can be a sign of ductus venosus agenesia.

  10. 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.

  11. Agarose gel purification of PCR products for denaturing gradient gel electrophoresis results in GC-clamp deletion.

    Science.gov (United States)

    Sun, Guowei; Xiao, Jinzhou; Lu, Man; Wang, Hongming; Chen, Xiaobing; Yu, Yongxin; Pan, Yingjie; Wang, Yongjie

    2015-01-01

    The 16S ribosomal RNA (rRNA) gene of marine archaeal samples was amplified using a nested PCR approach, and the V3 region of 16S rRNA gene of crab gut microbiota (CGM) was amplified using the V3 universal primer pair with a guanine and cytosine (GC)-clamp. Unpurified PCR products (UPPs), products purified from reaction solution (PPFSs), and products purified from gel (PPFGs) of above two DNA samples were used for denaturing gradient gel electrophoresis (DGGE) analysis, respectively. In contrast to almost identical band patterns shared by both the UPP and PPFS, the PPFGs were barely observed on the DGGE gel for both the marine archaea and CGM samples. Both PPFS and PPFG of CGM V3 regions were subjected to cloning. A small amount of positive clones was obtained for PPFS, but no positive clones were observed for PPFG. The melt curve and direct sequencing analysis of PPFS and PPFG of E. coli V3 region indicated that the Tm value of PPFG (82.35 ± 0.19 °C) was less than that of PPFS (83.81 ± 0.11 °C), and the number of shorter GC-clamps was significant higher in PPFG than in PPFS. The ultraviolet exposure experiment indicated that the ultraviolet was not responsible for the deletion of the GC-clamps. We conclude that the gel purification method is not suitable for DGGE PCR products or even other GC-rich DNA samples. PMID:25300603

  12. The inferiority complex in paranoia readdressed. A study with the Implicit Association Test

    OpenAIRE

    von Collani, Gernot; Werner, Ronny; Moritz, Steffen

    2006-01-01

    It has been theorised that patients with persecutory delusions display a lack of covert self-esteem (formerly termed the 'inferiority complex'), while at the same time displaying normal or even heightened levels of explicit self-esteem. However, the empirical basis for this assumption is inconsistent. Methods. In view of apparent shortcomings of prior studies to assess implicit self-esteem, the Implicit Association Test was utilised to readdress this theory. The Rosenberg scale served as an i...

  13. Individual structural differences in left inferior parietal area are associated with schoolchildrens’ arithmetic scores

    Directory of Open Access Journals (Sweden)

    Yongxin eLi

    2013-12-01

    Full Text Available Arithmetic skill is of critical importance for academic achievement, professional success and everyday life, and childhood is the key period to acquire this skill. Neuroimaging studies have identified that left parietal regions are a key neural substrate for representing arithmetic skill. Although the relationship between functional brain activity in left parietal regions and arithmetic skill has been studied in detail, it remains unclear about the relationship between arithmetic achievement and structural properties in left inferior parietal area in schoolchildren. The current study employed a combination of voxel-based morphometry (VBM for high-resolution T1-weighted images and fiber tracking on diffusion tensor imaging (DTI to examine the relationship between structural properties in the inferior parietal area and arithmetic achievement in 10-year-old schoolchildren. VBM of the T1-weighted images revealed that individual differences in arithmetic scores were significantly and positively correlated with the grey matter (GM volume in the left intraparietal sulcus (IPS. Fiber tracking analysis revealed that the forceps major, left superior longitudinal fasciculus (SLF, bilateral inferior longitudinal fasciculus (ILF and inferior fronto-occipital fasciculus (IFOF were the primary pathways connecting the left IPS with other brain areas. Furthermore, the regression analysis of the probabilistic pathways revealed a significant and positive correlation between the fractional anisotropy (FA values in the left SLF, ILF and bilateral IFOF and arithmetic scores. The brain structure-behavior correlation analyses indicated that the GM volumes in the left IPS and the FA values in the tract pathways connecting left IPS were both related to children’s arithmetic achievement. The present findings provide evidence that individual structural differences in the left IPS are associated with arithmetic scores in schoolchildren.

  14. Extra-Adrenal Retroperitoneal Paraganglioma with Extensive Duodenal Invasion and Inferior Vena Cava Tumor Thrombus.

    Science.gov (United States)

    Sadamori, Hiroshi; Monden, Kazuteru; Hioki, Masayoshi; Yoshimoto, Masashi; Ueki, Toru; Hyodo, Tsuyoshi; Omonishi, Kunihiro; Kioka, Yukio; Kuriyama, Mitsuhito; Ohno, Satoshi; Sakaguchi, Kohsaku; Matsuda, Tadakazu; Takakura, Norihisa

    2016-08-01

    We report a case of extra-adrenal retroperitoneal paraganglioma (RP) with extensive duodenal invasion and tumor thromboses both in the right testicular vein and in the inferior vena cava (IVC). Because there was rigid adherence between the RP and the abdominal aorta, pancreatoduodenectomy with replacement of the IVC and aorta was performed for complete surgical resection. In the present case, both the mode of progression of the RP and the surgical approach were extremely rare. PMID:26921027

  15. Bullet embolisation from injured inferior cava vein to the right ventricle

    OpenAIRE

    Zenelaj, A; M Brati; Kerci, M

    2010-01-01

    Gunshot injuries of the human body challenge surgical teams in the emergency department. Since such injuries do not follow any rule, every patient should be considered a special case. Our case, of bullet embolism from injured inferior cava vein to the right heart ventricle is a rare one. Such cases make us be more alert for diagnosis and treatment of this kind of injury. Well equipped hospitals and experienced medical teams are necessary for successful outcome.

  16. Male mate choice in hermit crabs: prudence by inferior males and simple preference by superior males

    OpenAIRE

    Wada, Satoshi; Arashiro, Yuusei; Takeshita, Fumio; Shibata, Yasutoki

    2011-01-01

    In species with both male-male competition and male mate choice, inferior males may make different mate choice decisions from superior males. Males of the intertidal hermit crab, Pagurus middendorffii, are known to conduct precopulatory guarding and to adjust the threshold for guarding according to social parameters, such as encounter rate with females, competitor size, and sex ratio. Larger males are stronger in male--male competition during guarding in this species. We here tested whether m...

  17. Inferior Alveolar Nerve Injury after Mandibular Third Molar Extraction: a Literature Review

    OpenAIRE

    Rafael Sarikov; Gintaras Juodzbalys

    2014-01-01

    ABSTRACT 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 minim...

  18. Inferior alveolar nerve injury following orthognathic surgery: a review of assessment issues

    OpenAIRE

    Phillips, C.; ESSICK, G.

    2010-01-01

    The sensory branches of the trigeminal nerve encode information about facial expressions, speaking and chewing movements, and stimuli that come into contact with the orofacial tissues. Whatever the cause, damage to the inferior alveolar nerve negatively affects the quality of facial sensibility as well as the patient's ability to translate patterns of altered nerve activity into functionally meaningful motor behaviours. There is no generally accepted, standard method of estimating sensory dis...

  19. Unusual inferior dislocation of shoulder: reduction by two-step maneuver: a case report

    OpenAIRE

    Patro Dilip K; Agarwal Dinesh K; Saseendar S; Menon Jagdish

    2009-01-01

    Abstract Dislocation of the shoulder is the commonest of all large joint dislocations. Inferior dislocation constitutes 0.5% of all shoulder dislocations. It characteristically presents with overhead abduction of the arm, the humerus being parallel to the spine of scapula. We present an unusual case of recurrent luxatio erecta in which the arm transformed later into an adducted position resembling the more common anterior shoulder dislocation. Such a case has not been described before in Engl...

  20. Right portal vein embolization by laparoscopic catheterization of the inferior mesenteric vein

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Martins Cury

    2013-12-01

    Full Text Available Right portal vein embolization is often performed to prevent liver insufficiency after major hepatic resection. The procedure usually involves direct puncture of the portal vein, which requires hepatic hilum manipulation, and may be associated with liver injury, pneumothorax, and hemoperitoneum. This report describes a technique of laparoscopic insertion of a sheath into the inferior mesenteric vein followed by right portal vein embolization.