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Sample records for clamp infrahepatic inferior

  1. IVC CLAMP: infrahepatic inferior vena cava clamping during hepatectomy - a randomised controlled trial in an interdisciplinary setting

    Directory of Open Access Journals (Sweden)

    Reissfelder Christoph

    2009-10-01

    Full Text Available Abstract Background Intraoperative haemorrhage is a known predictor for perioperative outcome of patients undergoing hepatic resection. While anaesthesiological lowering of central venous pressure (CVP by fluid restriction is known to reduce bleeding during transection of the hepatic parenchyma its potential side effects remain poorly investigated. In theory it may have negative effects on kidney function and tissue perfusion and bears the risk to result in severe haemodynamic instability in case of profound intraoperative blood loss. The present randomised controlled trial evaluates efficacy and safety of infrahepatic inferior vena cava (IVC clamping as an alternative surgical technique to reduce CVP during hepatic resection. Methods/Design The proposed IVC CLAMP trial is a single-centre randomised controlled trial with a two-group parallel design. Patients and outcome-assessors are blinded for the treatment intervention. Patients undergoing elective hepatic resection due to any reason are enrolled in IVC CLAMP. All patients admitted to the Department of General-, Visceral-, and Transplant Surgery, University of Heidelberg for elective hepatic resection are consecutively screened for eligibility and written informed consent is obtained on the day before surgery. The primary objective of this trial is to assess and compare the amount of blood loss during hepatic resection in patients receiving surgical CVP reduction by clamping of the IVC as compared to anaesthesiological CVP without infrahepatic IVC clamping reduction. In addition to blood loss a set of general as well as surgical variables are analysed. Discussion This is a randomised controlled patient and observer blinded two-group parallel trial designed to assess efficacy and safety of infrahepatic IVC clamping during elective hepatectomy. Trial registration ClinicalTrials NCT00732979

  2. 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.

  3. 肾上段肝下下腔静脉肿瘤的手术治疗%Resection for tumors of the suprarenal infrahepatic segment of the inferior vena cava

    Institute of Scientific and Technical Information of China (English)

    陈建飞; 程志雷; 田远虎; 蔡俊; 苗成利; 罗成华; 朱继业

    2016-01-01

    目的 探讨不同类型肾上段肝下下腔静脉肿瘤的手术治疗方法.方法 回顾性分析8例肾上段肝下下腔静脉肿瘤患者的临床资料.根据肿瘤侵犯的范围不同及侧支形成情况分别采取肿瘤切除+下腔静脉血管重建术,肿瘤切除+右肾切除术.采用配对资料t检验的方式检测肿瘤切除术后肾功能的恢复情况.结果 肾上段肝下下腔静脉肿瘤完整切除.术后12 d患者肾功能均恢复正常.随访,7例24个月无复发,1例切除术后12个月复发而再次手术,再次切除后随访12个月未复发.结论 肾上段肝下下腔静脉肿瘤根据术前增强CT及下腔静脉造影,可判断肿瘤侵犯的范围以及侧支循环形成的情况,提高肿瘤切除率,保护肾功能.%Objective To evaluate surgical treatment for different types of tumor of the suprarenal infrahepatic segment of the inferior vena cava (IVC).Methods A retrospective analysis was made on 8cases of IVC leiomyosarcoma at the suprarenal infrahepatic IVC segment.According to the extent of tumor invasion and collateral circulations,operations included tumor resection plus inferior vena cava reconstruction or tumor resection plus right nephrectomy.Results Tumors were completly resected in all patients.Renal function recovered after operation.During a follow up of 24 mons,7 cases had no recurrence.One case with recurrence after 12 months underwent successful resection and is doing well after a follow-up of 12 months.Conclusion CT and inferior vena cavography can determine the extent of tumor invasion and collateral circulations helping select appropriate surgical aproach before the operation resulting in less renal injury.

  4. 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.

  5. 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.

  6. 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.

  7. Antiphospholipid Antibody Syndrome Associated with Graves' Disease Presenting As Inferior Vena Cava Thrombosis with Bilateral Lower Limb DVT.

    Science.gov (United States)

    Jain, Ankur

    2014-01-01

    We report a case of a 60-year-old lady who presented with bilateral lower limb swelling and a thyroid swelling with clinical features consistent with thyrotoxicosis. Investigations revealed the presence of a thrombus in bilateral external, internal iliac veins, and inferior vena cava extending up to its infrahepatic part. Hormone profile and radioiodine uptake scan confirmed the diagnosis of Graves' disease. Further workup revealed the presence of antiphospholipid antibodies (confirmed after a repeat test at 12 weeks). The patient was treated with antithyroid drugs and anticoagulants. The patient improved with normalization of thyroid function and partial recanalization of the infrahepatic part of inferior vena cava. Hyperthyroidism has been implicated as a potential hypercoagulable state; however, the association of Graves' disease with antiphospholipid antibody syndrome is limited to isolated case reports. This case highlights a new mechanism underlying hypercoagulability associated with Graves' disease.

  8. [An exceptional case of renal angiomyolipoma extended to the inferior vena cava. Successfull surgical management].

    Science.gov (United States)

    Dinis da Gama, A; Cunha e Sá, Diogo; Alves, José Maria; Carneiro de Moura, J L; Lopez, Dolores; Fernandes, Afonso

    2008-01-01

    The clinical case of a 39 years old female is reported, with the diagnosis of tumor of the right kidney extending into the infra-hepatic vena cava, assuming the shape of a floating thrombus. The patient underwent right radical nephrectomy, followed by resection of the intra caval tumor. Both the procedure and post operative course were uneventfull. Histopathological evaluation of the specimens, associated to specific imunohistochemistry studies, confirmed the diagnosis of angiomyolipoma of the kidney. A review of the literature concluded that this is the 27th case published of a kidney angiomyolipoma extending into the inferior vena cava, thus justifying its presentation and divulgation.

  9. 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.

  10. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

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

    Directory of Open Access Journals (Sweden)

    Márcio Benedito Palma Pimenta

    2007-01-01

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

  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. 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

  14. Robotic Partial Nephrectomy Using Robotic Bulldog Clamps

    OpenAIRE

    2011-01-01

    Background and Objectives: The need for a skilled assistant to perform hilar clamping during robotic partial nephrectomy is a potential limitation of the technique. We describe our experience using robotic bulldog clamps applied by the console surgeon for hilar clamping. Methods: A total of 60 consecutive patients underwent robotic partial nephrectomy, 30 using laparoscopic bulldog clamps applied by the assistant and 30 using robotic bulldog clamps applied with the robotic Prograsp instrument...

  15. Automated planar patch-clamp.

    Science.gov (United States)

    Milligan, Carol J; Möller, Clemens

    2013-01-01

    Ion channels are integral membrane proteins that regulate the flow of ions across the plasma membrane and the membranes of intracellular organelles of both excitable and non-excitable cells. Ion channels are vital to a wide variety of biological processes and are prominent components of the nervous system and cardiovascular system, as well as controlling many metabolic functions. Furthermore, ion channels are known to be involved in many disease states and as such have become popular therapeutic targets. For many years now manual patch-clamping has been regarded as one of the best approaches for assaying ion channel function, through direct measurement of ion flow across these membrane proteins. Over the last decade there have been many remarkable breakthroughs in the development of technologies enabling the study of ion channels. One of these breakthroughs is the development of automated planar patch-clamp technology. Automated platforms have demonstrated the ability to generate high-quality data with high throughput capabilities, at great efficiency and reliability. Additional features such as simultaneous intracellular and extracellular perfusion of the cell membrane, current clamp operation, fast compound application, an increasing rate of parallelization, and more recently temperature control have been introduced. Furthermore, in addition to the well-established studies of over-expressed ion channel proteins in cell lines, new generations of planar patch-clamp systems have enabled successful studies of native and primary mammalian cells. This technology is becoming increasingly popular and extensively used both within areas of drug discovery as well as academic research. Many platforms have been developed including NPC-16 Patchliner(®) and SyncroPatch(®) 96 (Nanion Technologies GmbH, Munich), CytoPatch™ (Cytocentrics AG, Rostock), PatchXpress(®) 7000A, IonWorks(®) Quattro and IonWorks Barracuda™, (Molecular Devices, LLC); Dynaflow(®) HT (Cellectricon

  16. 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.

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

    Lifescience Database Archive (English)

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

  18. 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.

  19. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

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

  20. The RFC clamp loader: structure and function.

    Science.gov (United States)

    Yao, Nina Y; O'Donnell, Mike

    2012-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction.

  1. Varices en Miembros Inferiores

    OpenAIRE

    Velásquez, Edna

    2015-01-01

    Insuficiencia venosa, es cuando las venas de las extremidades inferiores no son capaces de devolver al corazón toda la sangre que les llega y de hacerlo al ritmo y velocidad debidos, se puede afirmar que sufren insuficiencia venosa.

  2. 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.

  3. 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.

  4. 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.

  5. Dynamic clamp with StdpC software.

    Science.gov (United States)

    Kemenes, Ildikó; Marra, Vincenzo; Crossley, Michael; Samu, Dávid; Staras, Kevin; Kemenes, György; Nowotny, Thomas

    2011-03-01

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

  6. Clamp force and alignment checking device

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-04-11

    A check fixture measures a total clamp force applied by a welder device. The welder device includes a welding horn having a plurality of weld pads and welding anvil having a plurality of weld pads. The check fixture includes a base member operatively supporting a plurality of force sensors. The base member and the force sensors are received between the weld pads of the welding horn and the anvil pads of the welding anvil. Each force sensor is configured to measure an individual clamp force applied thereto by corresponding weld and anvil pads when the base member is received between the welding horn and the welding anvil and the welder device is in the clamped position. The individual clamp forces are used to determine whether the weld and/or anvil pads are worn or misaligned.

  7. Molecular Mechanisms of DNA Polymerase Clamp Loaders

    Science.gov (United States)

    Kelch, Brian; Makino, Debora; Simonetta, Kyle; O'Donnell, Mike; Kuriyan, John

    Clamp loaders are ATP-driven multiprotein machines that couple ATP hydrolysis to the opening and closing of a circular protein ring around DNA. This ring-shaped clamp slides along DNA, and interacts with numerous proteins involved in DNA replication, DNA repair and cell cycle control. Recently determined structures of clamp loader complexes from prokaryotic and eukaryotic DNA polymerases have revealed exciting new details of how these complex AAA+ machines perform this essential clamp loading function. This review serves as background to John Kuriyan's lecture at the 2010 Erice School, and is not meant as a comprehensive review of the contributions of the many scientists who have advanced this field. These lecture notes are derived from recent reviews and research papers from our groups.

  8. Ergonomic redesign and evaluation of a clamping tool handle.

    Science.gov (United States)

    Jung, Myung-Chul; Hallbeck, M Susan

    2005-09-01

    The handle of a commercial bar clamp was redesigned using ergonomic principles and then compared with an original clamp. Ten male and ten female students participated in simulated clamping tasks under various conditions, including different clamping heights, clamping methods, and handle-gripping methods, with respect to the dependent variables of clamping and handle-squeezing forces. The results showed that the redesigned clamp produced larger clamping force with lower handle-squeezing forces than the original clamp. As expected, males exerted more force than females in both clamping and squeezing forces. A pistol grip method was superior to an upside-down handle-gripping method. Two-handed operation was recommended for this type of clamp by simultaneously pulling the trigger and sliding the bar in order to initially tighten around objects. This study shows that the application of ergonomic guidelines increases the efficiency and usability of manual handtools.

  9. 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.

  10. 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

  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.; 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

  12. Vascular clamping in liver surgery: physiology, indications and techniques

    Directory of Open Access Journals (Sweden)

    Cherqui Daniel

    2010-03-01

    Full Text Available Abstract This article reviews the historical evolution of hepatic vascular clamping and their indications. The anatomic basis for partial and complete vascular clamping will be discussed, as will the rationales of continuous and intermittent vascular clamping. Specific techniques discussed and described include inflow clamping (Pringle maneuver, extra-hepatic selective clamping and intraglissonian clamping and outflow clamping (total vascular exclusion, hepatic vascular exclusion with preservation of caval flow. The fundamental role of a low Central Venous Pressure during open and laparoscopic hepatectomy is described, as is the difference in their intra-operative measurements. The biological basis for ischemic preconditioning will be elucidated. Although the potential dangers of vascular clamping and the development of modern coagulation devices question the need for systemic clamping; the pre-operative factors and unforseen intra-operative events that mandate the use of hepatic vascular clamping will be highlighted.

  13. 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.

  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. Compact, Stiff, Remotely-Actuable Quick-Release Clamp

    Science.gov (United States)

    Tsai, Ted W. (Inventor)

    2000-01-01

    The present invention provides a clamp that is compact and lightweight, yet provides high holding strength and stiffness or rigidity. The clamp uses a unique double slant interface design which provides mechanical advantages to resist forces applied to the clamp member as the load increases. The clamp allows for rapid and remote-activated release of the clamp jaws by applying only a small operating force to an over-center lock/release mechanism, such as by pulling a manual tether.

  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. Cerebral haemodynamics during carotid cross-clamping.

    Science.gov (United States)

    Pistolese, G R; Ippoliti, A; Appolloni, A; Ronchey, S; Faraglia, V

    1993-03-01

    Carotid artery cross-clamping ischaemia during carotid endarterectomy (CEA) causes 5-30% of perioperative neurological deficits. This study was performed to identify possible clinical situations at higher risk for carotid cross-clamping ischaemia. 606 consecutive patients underwent CEA and were retrospectively studied; they were grouped according to risk factors, presence of associated vascular diseases, clinical pattern, angiographic and CT scan findings. Stump pressure measurement was provided in all patients, perioperative monitoring during CEA was performed by electroencephalogram (EEG) in 469 (77%) and somatosensorial evoked potentials (SEP) in 137 (23%). Local anaesthesia was used in 88 (14.5%) patients. Ischaemic changes during carotid cross-clamping were registered in 118 patients (19.5%). The incidence of cross-clamping ischaemia was then related to different factors; it affected 5.6% of asymptomatics, 25.4% of patients with fixed stroke and 38.5% of those with stenosis and contralateral occlusion. Angiographic and clinical correlation showed that patients with more severe lesions are mostly affected by clamping ischaemia (up to 55% in those with stroke and stenosis with contralateral occlusion). Age, hypertension and diabetes do not significantly affect incidence of ischaemic changes. Positive CT scan increased this risk; statistical relevance was found in regard to patients with unilateral or bilateral stenosis and in those with transient ischaemic attacks. A higher risk can be expected for subjects with more severe clinical and instrumental findings, even if no patients can be considered completely at risk or risk free. Perioperative monitoring is always mandatory and is of great importance in detecting ischaemic changes and preventing cerebral damage using a temporary intraluminal shunt.

  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. Mechanical and metallurgical properties of carotid artery clamps.

    Science.gov (United States)

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.

  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. Noninverted images in inferior mirages

    NARCIS (Netherlands)

    van der Werf, S.Y.

    2011-01-01

    Inferior mirages over sun-exposed roads often appear in isolated strips at their near sides and the reflected scenery exhibits multiple images. This effect is explained as due to slight undulations of the road's surface. At the same time, some of these images, although they are reflections, are not

  3. Vibration of an eccentrically clamped annular plate

    Science.gov (United States)

    Tseng, J.-G.; Wickert, J. A.

    1994-04-01

    Small amplitude vibration of an eccentric annular plate, which is free along its outer edge and clamped along the interior, is investigated through experimental and analytical methods. A disk with this geometry, or a stacked array in which the clamping and symmetry axes of each disk are nominally coincident, is common in data storage and brake systems applications. In the present case, the geometric imperfections on the boundary can have important implications for the disk's dynamic response. Changes that occur in the natural frequency spectrum, the mode shapes, and the free response under eccentric mounting are studied through laboratory measurements and an approximate discrete model of the plate. The natural frequencies and modes are found through global discretization of the Kamke quotient for a classical thin plate. For the axisymmetric geometry, the natural frequencies of the sine and cosine vibration modes for a specified number of nodal diameters are repeated. With increasing eccentricity, on the other hand, each pair of repeated frequencies splits at a rate that depends on the number of nodal diameters. Over a range of clamping and eccentricity ratios, the model's predictions are compared to the measured results.

  4. 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.

  5. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460 Section 882.4460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used...

  6. 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 ...

  7. 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.

  8. Tuberculosis pulmonar de campos inferiores

    OpenAIRE

    Alejandra González; Marcelo Fernández Casares; Matías Baldini; Alfredo Monteverde

    2010-01-01

    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 loc...

  9. Early Results of the “Clamp and Sew” Fontan Procedure Without the Use of Circulatory Support

    Science.gov (United States)

    Shinkawa, Takeshi; Anagnostopoulos, Petros V.; Johnson, Natalie C.; Presnell, Laura; Watanabe, Naruhito; Sapru, Anil; Azakie, Anthony

    2017-01-01

    Background A modification of the Fontan operation was recently applied, which includes anastomoses of the extra-cardiac conduit to the right pulmonary artery and inferior vena cava using simple clamping with no additional circulatory support, venous shunting, pulmonary artery preparation, or prior maintenance of azygos vein patency. The objective of this study is to assess the outcomes of this novel off-pump “clamp and sew” Fontan procedure. Methods This is a retrospective review of all patients having a Fontan procedure between January 2009 and October 2010 at a single institution. Results Twelve patients had a Fontan procedure with the use of cardiopulmonary bypass (CPB group), and 12 had an off-pump Fontan procedure (off-pump group). Preoperative demographic and hemodynamic data were similar except for higher mean pulmonary artery pressure in the CPB group (12.2 ± 1.6 mm Hg versus 9.9 ± 2.4 mm Hg; p = 0.02). No patients in the off-pump group required conversion to CPB. The mean inferior vena cava clamp time in the off-pump group patients was 10 ± 3 minutes. There were no early or midterm deaths. No patients exhibited postoperative hepatic or renal dysfunction. Postoperative maximal serum creatinine and aspartate transaminase were significantly lower in the off-pump group compared with the CPB group (0.59 ± 0.12 versus 0.77 ± 0.22 mg/dL; p = 0.03 and 35.5 ± 8.3 versus 53.1 ± 19.0 U/L; p = 0.02, respectively). At median follow-up of 13 months (range, 1 to 20 months), all but 1 patient in the CPB group are in New York Heart Association class I with unobstructed Fontan circulation. Conclusions The clamp and sew technique for completion of an extracardiac conduit Fontan procedure appears safe and feasible for selected patients. PMID:21524454

  10. The PCNA-RFC families of DNA clamps and clamp loaders.

    Science.gov (United States)

    Majka, Jerzy; Burgers, Peter M J

    2004-01-01

    The proliferating cell nuclear antigen PCNA functions at multiple levels in directing DNA metabolic pathways. Unbound to DNA, PCNA promotes localization of replication factors with a consensus PCNA-binding domain to replication factories. When bound to DNA, PCNA organizes various proteins involved in DNA replication, DNA repair, DNA modification, and chromatin modeling. Its modification by ubiquitin directs the cellular response to DNA damage. The ring-like PCNA homotrimer encircles double-stranded DNA and slides spontaneously across it. Loading of PCNA onto DNA at template-primer junctions is performed in an ATP-dependent process by replication factor C (RFC), a heteropentameric AAA+ protein complex consisting of the Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 subunits. Loading of yeast PCNA (POL30) is mechanistically distinct from analogous processes in E. coli (beta subunit by the gamma complex) and bacteriophage T4 (gp45 by gp44/62). Multiple stepwise ATP-binding events to RFC are required to load PCNA onto primed DNA. This stepwise mechanism should permit editing of this process at individual steps and allow for divergence of the default process into more specialized modes. Indeed, alternative RFC complexes consisting of the small RFC subunits together with an alternative Rfc1-like subunit have been identified. A complex required for the DNA damage checkpoint contains the Rad24 subunit, a complex required for sister chromatid cohesion contains the Ctf18 subunit, and a complex that aids in genome stability contains the Elg1 subunit. Only the RFC-Rad24 complex has a known associated clamp, a heterotrimeric complex consisting of Rad17, Mec3, and Ddc1. The other putative clamp loaders could either act on clamps yet to be identified or act on the two known clamps.

  11. Advanced patch-clamp techniques and single-channel analysis

    NARCIS (Netherlands)

    Biskup, B; Elzenga, JTM; Homann, U; Thiel, G; Wissing, F; Maathuis, FJM

    1999-01-01

    Much of our knowledge of ion-transport mechanisms in plant cell membranes comes from experiments using voltage-clamp. This technique allows the measurement of ionic currents across the membrane, whilst the voltage is held under experimental control. The patch-clamp technique was developed to study t

  12. 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

  13. 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...

  14. Studying mechanosensitive ion channels with an automated patch clamp

    NARCIS (Netherlands)

    Barthmes, Maria; Jose, Mac Donald F; Birkner, Jan Peter; Brüggemann, Andrea; Wahl-Schott, Christian; Kocer, Armagan

    2014-01-01

    Patch clamp electrophysiology is the main technique to study mechanosensitive ion channels (MSCs), however, conventional patch clamping is laborious and success and output depends on the skills of the operator. Even though automated patch systems solve these problems for other ion channels, they cou

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

    Directory of Open Access Journals (Sweden)

    Zhao Xinze

    2013-01-01

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

  16. 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...

  17. 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

  18. Trends in Aortic Clamp Use During Coronary Artery Bypass Surgery: The Effect of Aortic Clamping Strategies on Neurologic Outcomes

    Science.gov (United States)

    Daniel, William T.; Kilgo, Patrick; Puskas, John D.; Thourani, Vinod H.; Lattouf, Omar M.; Guyton, Robert A.; Halkos, Michael E.

    2013-01-01

    Objective The purpose of this study was to determine the impact of different clamping strategies during CABG on the incidence of postoperative stroke. Methods In this case-control study, all patients at Emory hospitals from 2002–2009 with postoperative stroke after isolated CABG (N=141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (N=565). Patients were matched according to the Society of Thoracic Surgeons (STS) Predicted Risk of Postoperative Stroke (PROPS), which is based on 26 variables. On- (ONCAB) and off-pump (OPCAB) patients were matched separately. Multiple logistic regression analysis with adjusted odds ratios (OR) was performed to identify operative variables associated with postoperative stroke. Results Among the ONCAB cohort, the single cross-clamp technique was associated with a decreased risk of stroke compared to the double clamp (cross clamp + partial clamp) technique (OR=0.385, p=0.044). Within the OPCAB cohort, there was no significant difference in stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002–2009, clamp use decreased from 97.7% of cases to 72.7%. Conclusions During ONCAB, the use of a single cross-clamp compared to the double clamp technique decreases the risk of postoperative stroke. The use of any aortic clamp has decreased and epiaortic ultrasound use has increased from 2002–2009, indicating a change in operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta. PMID:23477689

  19. Single electrode dynamic clamp with StdpC.

    Science.gov (United States)

    Samu, David; Marra, Vincenzo; Kemenes, Ildiko; Crossley, Michael; Kemenes, György; Staras, Kevin; Nowotny, Thomas

    2012-10-15

    Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations.

  20. 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

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

    Directory of Open Access Journals (Sweden)

    Xiao-ting Li

    2016-01-01

    Full Text Available 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.

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

    Institute of Scientific and Technical Information of China (English)

    Xiao-ting Li; Ning-yu Wang; Yan-jun Wang; Zhi-qing Xu; Jin-feng Liu; Yun-fei Bai; Jin-sheng Dai; Jing-yi Zhao

    2016-01-01

    Theγ-aminobutyric acid neurons (GABAergic neurons) in the inferior colliculus are classiifed into various patterns based on their intrin-sic electrical properties to a constant current injection. Although this classiifcation is associated with physiological function, the exact role for neurons with various ifring patterns in acoustic processing remains poorly understood. In the present study, we analyzed characteristics of inferior colliculus neuronsin 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 classiifed into two ifring patterns: sustained-regular (n = 4) and sustained-adapting ifring 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 ifring pattern were suppressed after stimulation, but recovered to normal levels following application of theγ-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 ifring patterns. Additionally, GABAergic projections from the dorsal nu-cleus of the lateral lemniscus to the inferior colliculus are associated with sound localization. The different neuronal responses of various ifring patterns suggest a role in sound localization. A better understanding of these mechanisms and functions will provide better clinical treatment paradigms for hearing deifciencies.

  3. Integral transform solutions of dynamic response of a clamped-clamped pipe conveying fluid

    Energy Technology Data Exchange (ETDEWEB)

    Gu Jijun; An Chen [Ocean Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68508, Rio de Janeiro 21941-972 (Brazil); Duan Menglan [Offshore Oil/Gas Research Center, China University of Petroleum, Beijing 102249 (China); Levi, Carlos [Ocean Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68508, Rio de Janeiro 21941-972 (Brazil); Su Jian, E-mail: sujian@nuclear.ufrj.br [Nuclear Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68509, Rio de Janeiro 21941-972 (Brazil)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Dynamic response of pipe conveying fluid was studied numerically. Black-Right-Pointing-Pointer The generalized integral transform technique (GITT) was applied. Black-Right-Pointing-Pointer Numerical solutions with automatic global accuracy control were obtained. Black-Right-Pointing-Pointer Excellent convergence behavior was shown. Black-Right-Pointing-Pointer Modal separation analysis was carried out and the influence of mass ratio was analyzed. - Abstract: Analysis of dynamic response of pipe conveying fluid is an important aspect in nuclear power plant design. In the present paper, dynamic response of a clamped-clamped pipe conveying fluid was solved by the generalized integral transform technique (GITT). The governing partial differential equation was transformed into a set of second-order ordinary differential equations which is then numerically solved by making use of the subroutine DIVPAG from IMSL Library. A thorough convergence analysis was performed to yield sets of reference results of the transverse deflection at different time and spanwise position. We found good agreement between the computed natural frequencies at mode 1-3 and those obtained by previous theoretical study. Besides, modal separation analysis was carried out and the influence of mass ratio on deflection and natural frequencies was qualitatively and quantitatively assessed.

  4. 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.

  5. 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.

  6. Delay in Clamping Umbilical Cord Benefits Babies, Doctors Say

    Science.gov (United States)

    ... doctors' group said. Although delayed clamping increases the newborn's risk of jaundice that will require treatment, ACOG said there's no evidence that waiting increases the mother's risk of hemorrhage. The guidelines are to be published in the ...

  7. 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.

  8. Choosing the wire clamp microdrive for termosonic microwelding equipments

    Directory of Open Access Journals (Sweden)

    Lanin V. L.

    2010-06-01

    Full Text Available The article describes research of three types of wire clamp microdrive for termosonic microwelding equipment, covering an expanded range microconductors from 12,5 up to 75 mm. The most preferable, in the light of their high-speed and easy-programming qualities, proved to be the mechanisms of conductor clamp with piezoelement drives and the loading system based on "voice-coil" type electromagnet.

  9. Prehospital Emergency Inguinal Clamp Controls Hemorrhage in Cadaver Model

    Science.gov (United States)

    2013-07-01

    the CRoC preassembled for quick use. The clamp compresses the casualty’s tissues and is unat- tached to things like a litter. When screwed down, it is...for use on the battlefield to control difficult bleeds in the inguinal area. Study Design The study design was a sequence of experiments of clamp...temperature 4 hours before testing. The torso was rotated onto a wood block to intubate the aorta through a left thoracotomy incision. The thoracic aorta

  10. Defining the non-inferiority margin and analyzing non-inferiority: An overview.

    Science.gov (United States)

    Althunian, Turki A; de Boer, Anthonius; Groenwold, Rolf H H; Klungel, Olaf H

    2017-03-02

    Non-inferiority trials are used to assess whether the effect of a new drug is not worse than an active comparator by more than a non-inferiority margin. If the difference between the new drug and the active comparator does not exceed this pre-specified margin, non-inferiority can be concluded. This margin must be specified based on clinical and statistical reasoning; however, it is considered as one the most challenging step in the design of non-inferiority trials. Regulators recommend that the margin should be defined based on the historical evidence of the active comparator (the latter is often the well-established standard treatment of the disease), which can be performed by different approaches. There are several factors and assumptions that need to be accounted for during the process of defining the margin and during the analysis of non-inferiority. Three methods are commonly used to analyze non-inferiority trials: the fixed-margin method, the point-estimate method, and the synthesis method. This article provides an overview of analyzing non-inferiority inferiority and choosing the non-inferiority margin.

  11. 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

  12. 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.

  13. [Advantage of delayed umbilical cord clamping in the newborn infant].

    Science.gov (United States)

    Menget, A; Mougey, C; Thiriez, G; Riethmuller, D

    2013-09-01

    The timing of umbilical cord clamping remains controversial. Although most maternity wards use the early clamping (5-15s), randomized studies and meta-analyses have demonstrated the benefit of delayed clamping for term and preterm newborn infants over the past 10 years. Indeed, placentofetal transfusion of 20-30 ml/kg in 2-3 min improves the iron status of term infants and prevents infant hypochromic anemia. Infant anemia is a public health problem in many developing countries. For preterm newborns, placental transfusion for 45 s or milking the cord for 15 s improves cardiovascular adaptation, with better hemodynamic stability, as well as decreased intraventricular hemorrhages, need for transfusion, and late-onset sepsis. A new look at this symbolic act is needed and professionals need to be persuaded of the importance of the "wait a minute" policy for a better physiological delivery.

  14. Arterial Clamping Increases Central Renal Cryoablation Efficacy: An Animal Study

    DEFF Research Database (Denmark)

    Nonboe, Lasse Larsen; Nielsen, Tommy Kjaergaard; Høyer, Søren;

    2017-01-01

    INTRODUCTION: The minimally invasive treatment of small renal masses with cryoablation has become increasingly widespread during the past 15 years. Studies with long-term follow-up are beginning to emerge, showing good oncological control, however, tumors with a central and endophytic location seem...... to possess an increased risk of treatment failure. Such tumors are likely to be subjected to a high volume of blood giving thermal protection to the cancerous cells. Arterial clamping during freezing might reduce this effect but at the same time subject the kidney to ischemia. The aim of this study...... was to evaluate the effect of renal artery clamping during cryoablation in a porcine survival model. METHODS: Ten Danish Landrace pigs (approximately 40 kg) underwent bilateral laparoscopic cryoablation with clamping of the right renal artery during freezing. The cryoablation consisted of a standard double...

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  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. INOVASI SAMBUNGAN MEKANIS MENGGUNAKAN CLAMP BAJA UNTUK TULANGAN BETON

    Directory of Open Access Journals (Sweden)

    Parmo

    2015-12-01

    Full Text Available In the last few years, Indonesian urban growth has tends to be lead to the overground space. This was caused by the significant population increasement the lackness of land availability. The phenomenon is also marked with the increasing number of high-rise buildings and skyscrapers. However, high-rise buildings and skyscrapers have the potential dangers against earthquakes, even more Indonesia lay on an earthquake-prone areas. There are two main things that need to be considered in the planning of earthquake-resistant buildings, which is strength and ductility. Deformation capability and the connection strength between the reinforcement taken into consideration in the design of earthquake-resistant structures. From the steel clamp tensile test results for D13’s mechanical connection reinforcement, it gained 270.69 Mpa for yield strength, 351.45 MPa for ultimate tensile strength and 4757 kg for maximum load with 40% elongation. As for the D16’s mechanical connection reinforcement gained 217.80 MPa for yield strength, 327 605 MPa for ultimate tensile strength and 6717 kg for maximum load with 32% elongation. This study uses two pieces of steel clamp, but in order to obtain a better result then it need to be add more clamps while increasing the steel clamp material quality.

  5. 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

  6. COMPARISON OF PARTIAL INFERIOR TURBINECTOMY AND SUBMUCOSAL DIATHERMY FOR HYPERTROPHIED INFERIOR TURBINATE IN ALLERGIC RHINITIS PATIENTS

    Directory of Open Access Journals (Sweden)

    Smitha Chandra

    2015-07-01

    Full Text Available BACKGROUND : The inferior turbinate is the first point of contact of allergen in the nose. In patients with allergic rhinitis the turbinate hypertrophies and its mucosa becomes purplish edematous. This leads to significant obstruction of airway. Hence reduction of this hypertrophied inferior turbinate is essential. AIM: To analyze & evaluate the efficacy of sub mucosal diathermy and partial inferior turbinectomy in the treatment of symptomatic hypertrophied inferior turbinates in allergic rhinitis patients in a rural setup. METHODS AND MATERIAL S: A prospective clinical study of 132 patients between age group of 15 - 55 years of eith er sex were enrolled in the study with bilateral Inferior. Turbinate Hypertrophy who had history of failed medical line of treatment. After informing , the patients were randomized into two groups to eliminate bias byallotting them alternately into the groups. Patients in Group I underwent. Submucosal diathermy and Group II patients underwent Partial Inferior. Turbinectomy. Postoperative follow up was done at regular intervals by objective& subjective assessment. STATISTICAL ANALYSIS USED: Friedman test and Ch i Square test were used for statistical analysis. RESULTS: In group I significant improvement of nasal airflow was seen in 14% patients & 85.9% had moderate improvement. In group II 41.3% of patients had significant improvement & 58.6% had moderate i mprovement. Statistically by analyzing the ranks of subjective nasal obstruction and objective nasal obstruction of Group - I & Group - IIwe conclude that Group - II subjects showed more improvement than Group I. CONCLUSIONS: Various surgical methods have been t ried for enlarged inferior turbinate secondary to allergic rhinitis. Of them the well - known techniques are s ubmucosal Diathermy & Partial Inferior Turbinectomy. In this study Partial Inferior Turbinectomy was found to be more effective in relieving nasal ob structionin allergic rhinitis patients for

  7. 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

  8. 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 assess...

  9. 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

  10. The bihemispheric posterior inferior cerebellar artery

    Energy Technology Data Exchange (ETDEWEB)

    Cullen, Sean P. [Brigham and Women' s Hospital and Children' s Hospital, Department of Radiology and Neurosurgery, Boston, MA (United States); Ozanne, Augustin; Alvarez, Hortensia; Lasjaunias, Pierre [Service de Neuroradiologie Diagnostic et Therapeutique, Hopital de Bicetre-Universite Paris-sud Orsay (France)

    2005-11-01

    Rarely, a solitary posterior inferior cerebellar artery (PICA) will supply both cerebellar hemispheres. We report four cases of this variant. We present a retrospective review of clinical information and imaging of patients undergoing angiography at our institution to identify patients with a bihemispheric PICA. There were four patients: three males and one female. One patient presented with a ruptured arteriovenous malformation, and one with a ruptured aneurysm. Two patients had normal angiograms. The bihemispheric PICA was an incidental finding in all cases. The bihemispheric vessel arose from the dominant left vertebral artery, and the contralateral posterior inferior cerebellar artery was absent or hypoplastic. In all cases, contralateral cerebellar supply arose from a continuation of the ipsilateral PICA distal to the choroidal point and which crossed the midline dorsal to the vermis. We conclude that the PICA may supply both cerebellar hemispheres. This rare anatomic variant should be considered when evaluating patients with posterior fossa neurovascular disease. (orig.)

  11. 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.

  12. 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...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    of load changes which can avoid neutral point balancing problem in such converters. In addition, the presented topology is suitable for renewable energy systems to boost the low rectified output-voltage. In order to verify the proposed topology, steady state analysis, modelling and simulations are carried......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...... points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless...

  14. Indentation metrology of clamped, ultra-thin elastic sheets

    OpenAIRE

    Vella, Dominic; Davidovitch, Benny

    2017-01-01

    We study the indentation of ultrathin elastic sheets clamped to the edge of a circular hole. This classical setup has received considerable attention lately, being used by various experimental groups as a probe to measure the surface properties and stretching modulus of thin solid films. Despite the apparent simplicity of this method, the geometric nonlinearity inherent in the mechanical response of thin solid objects renders the analysis of the resulting data a nontrivial task. Importantly, ...

  15. Cleaning patch-clamp pipettes for immediate reuse

    Science.gov (United States)

    Kolb, I.; Stoy, W. A.; Rousseau, E. B.; Moody, O. A.; Jenkins, A.; Forest, C. R.

    2016-01-01

    Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator. PMID:27725751

  16. File list: Oth.ALL.10.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.10.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159170,SRX15917...2,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.10.Clamp.AllCell.bed ...

  17. File list: Oth.ALL.05.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.05.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.05.Clamp.AllCell.bed ...

  18. File list: Oth.CeL.10.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.10.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159170,SRX159172,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.10.Clamp.AllCell.bed ...

  19. File list: Oth.CeL.20.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.20.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.20.Clamp.AllCell.bed ...

  20. File list: Oth.ALL.50.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.50.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.50.Clamp.AllCell.bed ...

  1. File list: Oth.ALL.20.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.20.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.20.Clamp.AllCell.bed ...

  2. File list: Oth.CeL.05.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.05.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.05.Clamp.AllCell.bed ...

  3. 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

  4. Inferior venacaval compression due to excessive abdominal packing

    Directory of Open Access Journals (Sweden)

    M.C.B. Santhosh

    2014-06-01

    Full Text Available Inferior venacaval compression is a common problem in late pregnancy. It can also occur due to compression of inferior venacava by abdominal or pelvic tumors. We report a case of acute iatrogenic inferior venacaval compression due to excessive abdominal packing during an intraabdominal surgery.

  5. 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).

  6. 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.

  7. Clamping stiffness and its influence on load distribution between paired internal spinal fixation devices.

    Science.gov (United States)

    Rohlmann, A; Calisse, J; Bergmann, G; Radvan, J; Mayer, H M

    1996-06-01

    The load distribution between two internal spinal fixation devices depends, besides other factors, on their stiffness. The stiffness ranges were determined experimentally for the clamps of the AO internal fixator with lateral nut and with posterior nut as well as for the clamps of the SOCON fixator. The stiffness of eight devices each differed by a factor of 3.1 for the clamp with lateral nut, by a factor of 1.5 for the clamp with posterior nut, and by a factor of 1.4 for the clamp of the SOCON fixator. For the AO clamp with lateral nut, the influence of the nut-tightening torque on the stiffness was determined. Using instrumented internal spinal fixation devices mounted to plastic vertebrae and simulating a corpectomy, the load distribution between the implants was measured for different tightening torques. It could be shown that, for the AO internal fixator whose clamps have a lateral nut, a nut-tightening torque > 5 Nm has only a negligible influence on load-sharing between the implants. Tooth damage occurs when the teeth of the clamp body and clamping jaw of the clamp with lateral nut do not gear together exactly, which leads to changes in the clamping stiffness and load-sharing between the two implants.

  8. Decompression of inferior alveolar nerve: case report.

    Science.gov (United States)

    Marques, Tiago Miguel Santos; Gomes, Joana Marques

    2011-01-01

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

  9. Pulsewidth Modulation of Neutral-Point-Clamped Indirect Matrix Converter

    DEFF Research Database (Denmark)

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

    2008-01-01

    discussed in the existing literature. Addressing the previously described issues, this paper focuses on the operational mode analysis of a three-level indirect matrix converter implemented using a neutral-point-clamped inversion stage and the design of a number of PWM and modulation ratio compensation...... schemes for controlling the converter with improved waveform quality. The performances and practicalities of the designed schemes are verified in simulation and experimentally using an implemented laboratory prototype with some representative results captured and presented in this paper....

  10. 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.

  11. Euglycemic clamp insulin sensitivity and longitudinal systolic blood pressure

    DEFF Research Database (Denmark)

    Petrie, John R; Malik, Muhammad Omar; Balkau, Beverley;

    2013-01-01

    and Cardiovascular disease (RISC) study, we measured insulin sensitivity (M/I) using the euglycemic clamp technique in 1073 healthy European adults (587 women, 486 men) aged 30 to 60 years followed up 3 years later. Systolic BP (SBP) at baseline was higher in insulin-resistant women (ie, those in the low sex......Insulin resistance may be an independent risk factor for the development of hypertension, but change in blood pressure (BP) over time has not been adequately studied in healthy individuals fully characterized for insulin sensitivity. In the Relationship between Insulin Sensitivity...

  12. Accelerated commutation for passive clamp isolated boost converters

    OpenAIRE

    2002-01-01

    An efficient and cost effective bidirectional DC/DC converter reduces switch voltage stress via accelerated commutation allowing use of a low-cost passive clamp circuit in boost mode. The converter includes a primary circuit, transformer and secondary circuit. The primary circuit takes the form of a “full bridge converter,” a “push-pull converter,” or an “L-type converter.”. The primary circuit may include a dissipator such as a snubber circuit or small buck converter. A secondary side of the...

  13. Properties of the nucleo-olivary pathway: an in vivo whole-cell patch clamp study.

    Directory of Open Access Journals (Sweden)

    Paolo Bazzigaluppi

    Full Text Available The inferior olivary nucleus (IO forms the gateway to the cerebellar cortex and receives feedback information from the cerebellar nuclei (CN, thereby occupying a central position in the olivo-cerebellar loop. Here, we investigated the feedback input from the CN to the IO in vivo in mice using the whole-cell patch-clamp technique. This approach allows us to study how the CN-feedback input is integrated with the activity of olivary neurons, while the olivo-cerebellar system and its connections are intact. Our results show how IO neurons respond to CN stimulation sequentially with: i a short depolarization (EPSP, ii a hyperpolarization (IPSP and iii a rebound depolarization. The latter two phenomena can also be evoked without the EPSPs. The IPSP is sensitive to a GABA(A receptor blocker. The IPSP suppresses suprathreshold and subthreshold activity and is generated mainly by activation of the GABA(A receptors. The rebound depolarization re-initiates and temporarily phase locks the subthreshold oscillations. Lack of electrotonical coupling does not affect the IPSP of individual olivary neurons, nor the sensitivity of its GABA(A receptors to blockers. The GABAergic feedback input from the CN does not only temporarily block the transmission of signals through the IO, it also isolates neurons from the network by shunting the junction current and re-initiates the temporal pattern after a fixed time point. These data suggest that the IO not only functions as a cerebellar controlled gating device, but also operates as a pattern generator for controlling motor timing and/or learning.

  14. 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

  15. Inferior alveolar nerve injuries associated with mandibular fractures.

    Science.gov (United States)

    Bede, Salwan Yousif Hanna; Ismael, Waleed Khaleel; Al-Assaf, Dhuha A; Omer, Saad Salem

    2012-11-01

    The study evaluates the incidence of inferior alveolar nerve injuries in mandibular fractures, the duration of their recovery, and the factors associated with them. Fifty-two patients with mandibular fractures involving the ramus, angle, and body regions were included in this study; the inferior alveolar nerve was examined for neurological deficit posttraumatically using sharp/blunt differentiation method, and during the follow-up period the progression of neural recovery was assessed. The incidence of neural injury of the inferior alveolar nerve was 42.3%, comminuted and displaced linear fractures were associated with higher incidence of inferior alveolar nerve injury and prolonged recovery time, and recovery of inferior alveolar nerve function occurred in 91%.Fractures of the mandible involving the ramus, angle, and body regions, and comminuted and displaced linear fractures are factors that increase the incidence of inferior alveolar nerve injuries. Missile injuries can be considered as another risk factor.

  16. 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.

  17. Partial breast reconstruction with mini superficial inferior epigastric artery and mini deep inferior epigastric perforator flaps.

    Science.gov (United States)

    Spiegel, Aldona J; Eldor, Liron

    2010-08-01

    In this study, partial breast reconstruction was undertaken after breast conservation therapy using mini abdominal free flaps on both an immediate and delayed basis.Patient demographics, oncologic status, reconstructive data, and complications were collected from medical records.Twelve patients (age range 39-60) were included in this study with a mean follow-up time of 5 years. Ten mini superficial inferior epigastric artery flaps and 2 mini deep inferior epigastric perforator flaps were used (7 immediate and 5 delayed reconstructions). No flap lost, 1 minor abdominal wound dehiscence, and no local or distant recurrences were noted. Good to excellent results were reported by 91% of the women.In properly selected patients with high motivation toward breast conservation, tailored abdominal mini-free flaps can safely and satisfactorily be implemented for the reconstruction of partial mastectomy defects. Patients should be comprehensively educated on the potential future implications of using the abdominal donor site for partial breast reconstruction.

  18. PERFORATION OF INFERIOR ALVEOLAR NERVE BY MAXILLARY ARTERY. LA PERFORACION DEL NERVIO ALVEOLAR INFERIOR POR LA ARTERIA MAXILAR

    OpenAIRE

    Vanishree S Nayak; Ramachandra Bhat K; Prakash Billakanti Babu

    2011-01-01

    Infratemporal fossa is clinically important anatomical area for the delivery of local anesthetic agents in dentistry and maxillofacial surgery. Variations in the anatomy of the inferior alveolar nerve and maxillary artery were studied in infratemporal dissection. During routine dissection of the head in an adult male cadaver an unusual variation in the origin of the inferior alveolar nerve and its relationship with the surrounding structures was observed. The inferior alveolar nerve originate...

  19. 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

    ("ANG II clamp"). When blood pressure was acutely increased 50-60 mmHg by arterial constriction without ANG II clamp, urine output and endogenous lithium clearance increased 4.0- and 6.7-fold, respectively. With ANG II clamp, the effects of acute hypertension were reduced 50%: urine output...... 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...

  20. 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...

  1. 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.

  2. Mechanism of ATP-driven PCNA clamp loading by S. cerevisiae RFC.

    Science.gov (United States)

    Chen, Siying; Levin, Mikhail K; Sakato, Miho; Zhou, Yayan; Hingorani, Manju M

    2009-05-08

    Circular clamps tether polymerases to DNA, serving as essential processivity factors in genome replication, and function in other critical cellular processes as well. Clamp loaders catalyze clamp assembly onto DNA, and the question of how these proteins construct a topological link between a clamp and DNA, especially the mechanism by which ATP is utilized for the task, remains open. Here we describe pre-steady-state analysis of ATP hydrolysis, proliferating cell nuclear antigen (PCNA) clamp opening, and DNA binding by Saccharomyces cerevisiae replication factor C (RFC), and present the first kinetic model of a eukaryotic clamp-loading reaction validated by global data analysis. ATP binding to multiple RFC subunits initiates a slow conformational change in the clamp loader, enabling it to bind and open PCNA and to bind DNA as well. PCNA opening locks RFC into an active state, and the resulting RFC.ATP.PCNA((open)) intermediate is ready for the entry of DNA into the clamp. DNA binding commits RFC to ATP hydrolysis, which is followed by PCNA closure and PCNA.DNA release. This model enables quantitative understanding of the multistep mechanism of a eukaryotic clamp loader and furthermore facilitates comparative analysis of loaders from diverse organisms.

  3. 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...... is 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....

  4. 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...... 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...... 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...

  5. Surgical extraction of impacted inferior third molars at risk for inferior alveolar nerve injury.

    Science.gov (United States)

    Gallesio, Cesare; Berrone, Mattia; Ruga, Emanuele; Boffano, Paolo

    2010-11-01

    The objective of the study was to prospectively assess the intraoperative findings and the radiographic signs of a study population of patients with impacted third molars at risk of inferior alveolar nerve injury. One hundred thirty-four patients with impacted mandibular third molars at risk for nerve injury were included in the study. Radiographic signs of possible close relationship between the 2 structures and intraoperative exposition or damage of the inferior alveolar nerve were recorded. The follow-up controls comprised clinical examinations and assessment for the sensation of the lower lip and chin. In 24 patients, a real contiguity was encountered between the third molars and nerve. Among these, intraoperative neural exposition was observed in 19 patients. Four patients complained of postoperative temporary hypoesthesia. No deficit of sensibility was found in cases with no exposition of the nerve. The accidental exposition of the inferior alveolar nerve is associated with an increased risk for neural injuries. At panoramic radiograph, the presence of signs of bifid and radiolucent apex, superimposition, and radiolucent root band should be considered at high risk for neural damage.

  6. PARTIAL INFERIOR TURBINECTOMY FOR INFERIOR TURBINATE HYPERTROPHY: REVIEW OF 30 CASES

    Directory of Open Access Journals (Sweden)

    Vishnu

    2016-05-01

    Full Text Available OBJECTIVES To compare the preoperative and postoperative subjective, objective parameters and postoperative complications of 30 patients with nasal obstruction due to inferior turbinate hypertrophy following partial inferior turbinectomy. PATIENTS AND METHODS A prospective observational study involving 30 patients with nasal obstruction due to inferior turbinate hypertrophy was done at SGMC, TVM from January 2014 to June 2015. Patients were evaluated preoperatively and postoperatively based on subjective and objective parameters. Postoperative evaluation was done at day 1, 1 week, 1 month and 3 months based on subjective and objective parameters and postoperative complications. RESULTS Snoring among the study population decreased from 26.7% to 10% at the end of 1 month and was further reduced 3.3% at the end of 3 months. Feeling of nasal obstruction, present in all patients, preoperatively was reduced to 36.7%, 16.7% and 3.3% at the end of 1 week, 1 month, and 3 months respectively. Among preoperative objective parameters, cold spatula test which was showing decreased fogging for all patients initially, following the procedure showed improvement in fogging in 70%, 90%, 100% of patients at the end of 1 week, 1 month and 3 months postoperatively. Anterior rhinoscopy showing large turbinate in all patients preoperatively, showed reduction in turbinate size in 70%, 86.73% and 96.7% at the end of 1 week, 1 month and 3 months respectively. Radiological evidence of enlarged inferior turbinate present in all patients was reduced to 3.3% at the end of 3 months. Occurrence of postoperative reactionary haemorrhage on day 1 was 43.3%. Nasal crust formation was not seen in 6.7% of the patients by the end of 3 months. Nasal pain was seen in 6.7% of the patients at the end of 1 week. Remote sequelae like synechiae and atrophic rhinitis were not reported in any of the patients during the assessment time period. CONCLUSION PIT is an effective technique for

  7. Through the looking glass: understanding non-inferiority

    Directory of Open Access Journals (Sweden)

    Wittes Janet T

    2011-05-01

    Full Text Available Abstract Non-inferiority trials test whether a new product is not unacceptably worse than a product already in use. This paper introduces concepts related to non-inferiority, and discusses the regulatory views of both the European Medicines Agency and the United States Food and Drug Administration.

  8. 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.)

  9. 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)

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. On the mechanism of loading the PCNA sliding clamp by RFC.

    Science.gov (United States)

    Dionne, Isabelle; Brown, Nicola J; Woodgate, Roger; Bell, Stephen D

    2008-04-01

    Sliding clamps play central roles in a broad range of DNA replication and repair processes. The clamps form circular molecules that must be opened and resealed around DNA by the clamp loader complex to fulfil their function. While most eukaryotes and many archea possess a homo-trimeric PCNA, the PCNA of Sulfolobus solfataricus is a heterotrimer. Here, we exploit the asymmetry of S. solfataricus PCNA to create a series of circularly permuted PCNA subunit fusions, thereby covalently closing defined interfaces within the heterotrimer. Using these concatamers, we investigate the requirements for loading the clamp onto DNA and reveal that a single defined interface within the heterotrimer is opened during the loading process. Subunit-specific interactions between S. solfataricus RFC clamp loader and PCNA permit us to superimpose our data upon the structure of yeast RFC-PCNA complex, thereby presenting a general model for PCNA loading by RFC in archaea and eukaryotes.

  16. 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.

  17. Simultaneous patch-clamping and calcium imaging in developing dendrites.

    Science.gov (United States)

    Kleindienst, Thomas; Lohmann, Christian

    2014-03-01

    Calcium imaging has been used extensively to explore the role of action potential (AP) firing in the development of neuronal structure and synaptic function because increases in intracellular calcium ([Ca(2+)]i) reliably and, within a certain range, linearly reflect neuronal spiking activity. Patterns of APs in individual cells can be deduced from calcium recordings, which have typically been performed at the level of cell bodies. However, neurons are particularly susceptible to phototoxicity when they are illuminated at the soma. Furthermore, for some imaging experiments (e.g., those that address the interactions between dendrites and axons during synapse formation), the cell body of a given neuron may simply not be in the field of view. In these situations, it would be helpful to determine the spiking patterns of a neuron from the calcium activity in its subcellular compartments such as stretches of dendrites or axons. Here, we describe an approach for determining the relationship between AP firing and dendritic calcium transients by simultaneously imaging calcium transients in small dendritic stretches of hippocampal pyramidal neurons in slice cultures from neonatal rats and recording spiking activity with whole-cell patch-clamp recordings in these neurons. These experiments allow us to correlate the electrophysiological spiking pattern with the accompanying changes in the calcium concentration in individual dendritic segments.

  18. Non-Hookean statistical mechanics of clamped graphene ribbons

    Science.gov (United States)

    Bowick, Mark J.; Košmrlj, Andrej; Nelson, David R.; Sknepnek, Rastko

    2017-03-01

    Thermally fluctuating sheets and ribbons provide an intriguing forum in which to investigate strong violations of Hooke's Law: Large distance elastic parameters are in fact not constant but instead depend on the macroscopic dimensions. Inspired by recent experiments on free-standing graphene cantilevers, we combine the statistical mechanics of thin elastic plates and large-scale numerical simulations to investigate the thermal renormalization of the bending rigidity of graphene ribbons clamped at one end. For ribbons of dimensions W ×L (with L ≥W ), the macroscopic bending rigidity κR determined from cantilever deformations is independent of the width when W expected. When W >ℓth , however, this thermally renormalized bending rigidity begins to systematically increase, in agreement with the scaling theory, although in our simulations we were not quite able to reach the system sizes necessary to determine the fully developed power law dependence on W . When the ribbon length L >ℓp , where ℓp is the W -dependent thermally renormalized ribbon persistence length, we observe a scaling collapse and the beginnings of large scale random walk behavior.

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

    Directory of Open Access Journals (Sweden)

    Goedken Eric R

    2010-01-01

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

  20. A Central Swivel Point in the RFC Clamp Loader Controls PCNA Opening and Loading on DNA

    OpenAIRE

    Sakato, Miho; O’Donnell, Mike; Hingorani, Manju M.

    2011-01-01

    Replication Factor C (RFC) is a 5-subunit complex that loads PCNA clamps onto primer-template DNA (ptDNA) during replication. RFC subunits belong to the AAA+ superfamily, and their ATPase activity drives interactions between the clamp loader, clamp, and ptDNA, leading to topologically linked PCNA•ptDNA. We report the kinetics of transient events in S. cerevisiae RFC catalyzed PCNA loading, including ATP-induced RFC activation, PCNA opening, ptDNA binding, ATP hydrolysis, PCNA closing and PCNA...

  1. 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 paramet...

  2. Anterior transposition of the inferior oblique muscle as the initial treatment of a snapped inferior rectus muscle.

    Science.gov (United States)

    Aguirre-Aquino, B I; Riemann, C D; Lewis, H; Traboulsi, E I

    2001-02-01

    Snapping or tearing of an extraocular muscle refers to its rupture across its width, usually at the junction between muscle and tendon several millimeters behind the insertion. Tearing occurs during strabismus or retinal reattachment surgery, or after trauma. If the proximal end of the muscle cannot be located, transposition procedures are necessary to achieve ocular realignment. These surgical procedures carry the risk of anterior segment ischemia, especially in the elderly. Anterior transposition of the inferior oblique muscle has been used for the treatment of inferior oblique overaction, especially in the presence of a dissociated vertical deviation, and in patients with fourth nerve palsy. We transposed the inferior oblique muscle insertion in a 73-year-old woman with a snapped inferior rectus muscle.

  3. Effect of modified inferior oblique anterior transposition on dissociated vertical strabismus patients with inferior oblique muscle hyperfunction

    Directory of Open Access Journals (Sweden)

    Xi-Lang Wang

    2017-02-01

    Full Text Available AIM: To investigate the effect of anterior transposition of inferior oblique muscle on the treatment of dissociated vertical deviation(DVDin children with inferior oblique overaction(IOOAand unequal inferior oblique transposition of the treatment of IOOA with the eyes of the asymmetry of DVD efficacy, associated with the lower oblique hyperfunction DVD patients to provide more effective treatment. METHODS: Eighty patients with hyperfunction who were treated in our hospital from January 2014 to December 2015 were randomly selected and treated with anterior transposition of inferior oblique muscle. Patients were followed up for 1 to 30mo. We compared the vertical incline at the original incline from far(5m, near(33cmdistance and IOOA degree before and after operations, and the correlation between the two. We also compared the vertical incline at the original incline from far(5m, near(33cmdistance and IOOA degree before and after operations in 30 eyes(20 patientswith bilateral asymmetry DVD and IOOA who received unequal inferior oblique transposition. The incidence of antielevation syndrome(AESwas observed after operations. RESULTS: The mean prism diopters(PDat 5m before operations was 19.5±0.15, the average PD after operations was 3.5±0.18, at 5m the original incline was 16±0.21PD. The mean PD at 33cm was 18.6±0.20 before operation, 4.5±0.26 after operations, and 14.1±0.16 at 33cm the original incline, the difference was statistically significant(Pr=0.554, Pr=0.454, P PPCONCLUSION: Anterior transposition of the inferior oblique muscle has a good therapeutic effect on isolated vertical strabismus patients with inferior oblique hyperfunction. While the incidence of postoperative AES is low in patients received unequal inferior oblique muscle transposition.

  4. Implementation of a fast 16-Bit dynamic clamp using LabVIEW-RT.

    Science.gov (United States)

    Kullmann, Paul H M; Wheeler, Diek W; Beacom, Joshua; Horn, John P

    2004-01-01

    The dynamic-clamp method provides a powerful electrophysiological tool for creating virtual ionic conductances in living cells and studying their influence on membrane potential. Here we describe G-clamp, a new way to implement a dynamic clamp using the real-time version of the Lab-VIEW programming environment together with a Windows host, an embedded microprocessor that runs a real-time operating system and a multifunction data-acquisition board. The software includes descriptions of a fast voltage-dependent sodium conductance, delayed rectifier, M-type and A-type potassium conductances, and a leak conductance. The system can also read synaptic conductance waveforms from preassembled data files. These virtual conductances can be reliably implemented at speeds LabVIEW should make it relatively easy for others to adapt G-clamp for new experimental applications.

  5. 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.

  6. Electrosurgical bipolar vessel sealing versus conventional clamping and suturing for total abdominal hysterectomy: a randomized trial.

    NARCIS (Netherlands)

    Lakeman, M.; Kruitwagen, R.F.P.M.; Vos, M.C.; Roovers, J.P.

    2008-01-01

    STUDY OBJECTIVE: To compare the effects of bipolar vessel sealing versus conventional clamping and suturing in women undergoing total abdominal hysterectomy. DESIGN: A randomized controlled trial was performed. Patients were randomized to vessel sealing or conventional surgery. Postoperative pain wa

  7. 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...... analysis of common mode voltage for switching states of diode clamping 3-level inverter is given in detail. Second the common mode voltage eliminating control strategy of SVM is described for diode clamping three-level inverter. Third, PLECS is briefly introduced. Fourth, the modeling of diode clamping...... three-level inverter is presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS is a very powerful tool to real power circuits modeling. They have also verified that proposed common mode voltage eliminating control strategy of SVM is feasible...

  8. 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

  9. 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.

  10. 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

  11. 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.

  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. A novel monolithic piezoelectric actuated flexure-mechanism based wire clamp for microelectronic device packaging

    Science.gov (United States)

    Liang, Cunman; Wang, Fujun; Tian, Yanling; Zhao, Xingyu; Zhang, Hongjie; Cui, Liangyu; Zhang, Dawei; Ferreira, Placid

    2015-04-01

    A novel monolithic piezoelectric actuated wire clamp is presented in this paper to achieve fast, accurate, and robust microelectronic device packaging. The wire clamp has compact, flexure-based mechanical structure and light weight. To obtain large and robust jaw displacements and ensure parallel jaw grasping, a two-stage amplification composed of a homothetic bridge type mechanism and a parallelogram leverage mechanism was designed. Pseudo-rigid-body model and Lagrange approaches were employed to conduct the kinematic, static, and dynamic modeling of the wire clamp and optimization design was carried out. The displacement amplification ratio, maximum allowable stress, and natural frequency were calculated. Finite element analysis (FEA) was conducted to evaluate the characteristics of the wire clamp and wire electro discharge machining technique was utilized to fabricate the monolithic structure. Experimental tests were carried out to investigate the performance and the experimental results match well with the theoretical calculation and FEA. The amplification ratio of the clamp is 20.96 and the working mode frequency is 895 Hz. Step response test shows that the wire clamp has fast response and high accuracy and the motion resolution is 0.2 μm. High speed precision grasping operations of gold and copper wires were realized using the wire clamper.

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

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    Chandragirish S

    2014-11-01

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

  15. 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.

  16. The effects of inferior olive lesion on strychnine seizure

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.C.; Chung, E.Y.; Van Woert, M.H. (Mount Sinai School of Medicine, New York, NY (USA))

    1990-10-01

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

  17. Inferior oblique muscle paresis as a sign of myasthenia gravis.

    Science.gov (United States)

    Almog, Yehoshua; Ben-David, Merav; Nemet, Arie Y

    2016-03-01

    Myasthenia gravis may affect any of the six extra-ocular muscles, masquerading as any type of ocular motor pathology. The frequency of involvement of each muscle is not well established in the medical literature. This study was designed to determine whether a specific muscle or combination of muscles tends to be predominantly affected. This retrospective review included 30 patients with a clinical diagnosis of myasthenia gravis who had extra-ocular muscle involvement with diplopia at presentation. The diagnosis was confirmed by at least one of the following tests: Tensilon test, acetylcholine receptor antibodies, thymoma on chest CT scan, or suggestive electromyography. Frequency of involvement of each muscle in this cohort was inferior oblique 19 (63.3%), lateral rectus nine (30%), superior rectus four (13.3%), inferior rectus six (20%), medial rectus four (13.3%), and superior oblique three (10%). The inferior oblique was involved more often than any other muscle (pmyasthenia gravis can be difficult, because the disease may mimic every pupil-sparing pattern of ocular misalignment. In addition diplopia caused by paresis of the inferior oblique muscle is rarely encountered (other than as a part of oculomotor nerve palsy). Hence, when a patient presents with vertical diplopia resulting from an isolated inferior oblique palsy, myasthenic etiology should be highly suspected.

  18. 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.

  19. 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.

  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. 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.

  2. 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.

  3. 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

  4. 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.

  5. A central swivel point in the RFC clamp loader controls PCNA opening and loading on DNA.

    Science.gov (United States)

    Sakato, Miho; O'Donnell, Mike; Hingorani, Manju M

    2012-02-17

    Replication factor C (RFC) is a five-subunit complex that loads proliferating cell nuclear antigen (PCNA) clamps onto primer-template DNA (ptDNA) during replication. RFC subunits belong to the AAA(+) superfamily, and their ATPase activity drives interactions between the clamp loader, the clamp, and the ptDNA, leading to topologically linked PCNA·ptDNA. We report the kinetics of transient events in Saccharomyces cerevisiae RFC-catalyzed PCNA loading, including ATP-induced RFC activation, PCNA opening, ptDNA binding, ATP hydrolysis, PCNA closing, and PCNA·ptDNA release. This detailed perspective enables assessment of individual RFC-A, RFC-B, RFC-C, RFC-D, and RFC-E subunit functions in the reaction mechanism. Functions have been ascribed to RFC subunits previously based on a steady-state analysis of 'arginine-finger' ATPase mutants; however, pre-steady-state analysis provides a different view. The central subunit RFC-C serves as a critical swivel point in the clamp loader. ATP binding to this subunit initiates RFC activation, and the clamp loader adopts a spiral conformation that stabilizes PCNA in a corresponding open spiral. The importance of RFC subunit response to ATP binding decreases as RFC-C>RFC-D>RFC-B, with RFC-A being unnecessary. RFC-C-dependent activation of RFC also enables ptDNA binding, leading to the formation of the RFC·ATP·PCNA(open)·ptDNA complex. Subsequent ATP hydrolysis leads to complex dissociation, with RFC-D activity contributing the most to rapid ptDNA release. The pivotal role of the RFC-B/C/D subunit ATPase core in clamp loading is consistent with the similar central location of all three ATPase active subunits of the Escherichia coli clamp loader.

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

    Directory of Open Access Journals (Sweden)

    Gilberto José Cação Pereira

    2008-07-01

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

  7. Incision Below The Clamp sebagai Modifikasi Teknik Insisi pada Frenektomi untuk Minimalisasi Perdarahan

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    S. Suryono

    2016-10-01

    Full Text Available Latar Belakang. Perlekatan frenulum tinggi berdampak merugikan bagi jaringan periodontal maupun fungsi estetik. Perlekatan tinggi yang terjadi pada labialis superior, menimbulkan gingivitis dan sentral diastema yang menjadikan indikasi untuk dilakukan frenektomi. Frenektomi dengan teknik melakukan insisi di atas dan di bawah clamp berakibat lebarnya luka karena tarikan otot bibir, yang berdampak terjadi banyak perdarahan. Tujuan. Melakukan evaluasi terhadap modifikasi teknik insisi yang diharapkan dapat mengurangi perdarahan. Kasus dan Penanganan. Laporan kasus ini memaparkan penanganan kasus pada perlekatan frenulum tinggi yang diikuti adanya sentral diastema. Pasien dengan diagnosa frenulum tinggi dan indikasi frenektomi dilakukan tindakan preoperasi. Tindakan operasi dilakukan dengan menggunakan pisau bedah, modifikasi insisi (Insision below the Clamp dilakukan dengan cara menempatkan clamp frenulum pada posisi yang berdekatan dan sejajar dengan bibir, tindakan insisi dilakukan di bawah clamp, disusul dengan penjahitan pada area mucolabial fold. Selama operasi dilakukan terlihat luka tidak melebar, tidak banyak darah yang keluar, pasien dan dokter merasa nyaman. Kesimpulan. Insision below the Clamp merupakan modifikasi teknik insisi pada frenektomi yang bisa dilakukan oleh para praktisi untuk meminimalisir perdarahan yang terjadi selama proses pengambilan frenulum dengan menggunakan pisau bedah.   Background. Attachment of high frenulum has negative impact on periodontal tissues as well as an aesthetic function. High attachment of frenulum that occurs in labialis superior, causing gingivitis and central diastema that are indications to do Frenectomy. Conventional techniques of Frenectomy performed with insisions above and below the clamp resulted in wide injury due to muscle contraction, which affects a lot of bleeding. Objective. To evaluate modification insision technique which hopefully can minimize the bleeding. Case and Treatment. This

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. An unusual delayed complication of inferior alveolar nerve block.

    Science.gov (United States)

    Smyth, Joanna; Marley, John

    2010-01-01

    Systemic and localised complications after administration of local anaesthetic for dental procedures are well recognised. We present two cases of patients with trismus and sensory deficit that arose during resolution of trismus as a delayed complication of inferior alveolar nerve block.

  13. Endodontic-related inferior alveolar nerve and mental foramen paresthesia.

    Science.gov (United States)

    Morse, D R

    1997-10-01

    Paresthesia is a condition that involves perverted sensations of pain, touch, or temperature. It has a variety of possible causes. This article presents a literature review and case reports of endodontically related inferior alveolar nerve and mental foramen paresthesia. Nondrug prevention methods and the dental uses of dexamethasone are also discussed.

  14. 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

  15. [Resection of leiomyosarcoma of the inferior vena cava].

    Science.gov (United States)

    Zotov, S P; Pyshkin, S A; Malyshev, M Iu; Safuanov, A Kh; Borovikov, D A; Siniukov, D M; Tereshin, O S; Panov, I O

    2013-01-01

    Experience in treatment of leiomyosarcoma of the retrohepatic segment of the inferior vena cava at any separately taken clinic is scarce. Given a rare nature of the pathology involved, whose diagnosis and management require joint participation of various-specialty physicians, we have considered it wise to present our own clinical case report.

  16. INVOLVEMENT OF THE INFERIOR CAVAL VEIN IN ADRENAL METASTASIS

    NARCIS (Netherlands)

    VANDALEN, KC; VANDRIEL, MF; MENSINK, HJA

    1992-01-01

    A patient was referred to our hospital for resection of a large renal cell carcinoma with invasion of the inferior caval vein, diagnosed as such with CT, angiography and cavography. The history mentioned partial resection of the left lung for lung carcinoma 16 months before. At operation the tumor c

  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. 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.

  19. Sequential dissection of multiple ionic currents in single cardiac myocytes under action potential-clamp.

    Science.gov (United States)

    Banyasz, Tamas; Horvath, Balazs; Jian, Zhong; Izu, Leighton T; Chen-Izu, Ye

    2011-03-01

    The cardiac action potential (AP) is shaped by myriad ionic currents. In this study, we develop an innovative AP-clamp Sequential Dissection technique to enable the recording of multiple ionic currents in the single cell under AP-clamp. This new technique presents a significant step beyond the traditional way of recording only one current in any one cell. The ability to measure many currents in a single cell has revealed two hitherto unknown characteristics of the ionic currents in cardiac cells: coordination of currents within a cell and large variation of currents between cells. Hence, the AP-clamp Sequential Dissection method provides a unique and powerful tool for studying individual cell electrophysiology.

  20. 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.

  1. Modified Blalock clamp: a single-hand autostatic device for pulmonary vessel occlusion during lung cancer resection

    OpenAIRE

    Petrella, Francesco; Solli, Piergiorgio; Borri, Alessandro; Spaggiari, Lorenzo

    2011-01-01

    Vascular clamping during lung cancer resection may be difficult in patients with short vessels or large neoplasms preventing adequate and safe exposure. In addition, the physiological vicinity of some vessels to rigid structures like the bronchi may interfere with ideal clamp positioning even in ordinary procedures. We have modified the original Blalock clamp to facilitate the control of pulmonary vessels and physiologically compress the vessel walls, thereby allowing optimal vascular resecti...

  2. Comparison of herniorrhaphy versus clamping of umbilical hernias in horses: a retrospective study of 93 cases (1982-1994).

    OpenAIRE

    1996-01-01

    Many uncomplicated umbilical hernias have been managed successfully in foals by the application of a hernia clamp. Isolated reports of complications following clamp application have led some authors to suggest that it is an unsuitable method of treatment. Little information has been published comparing the complication rates associated with the use of hernia clamps and herniorrhaphy in the treatment of umbilical hernias. The purpose of this retrospective study was to report the characteristic...

  3. Can robots patch-clamp as well as humans? Characterization of a novel sodium channel mutation.

    Science.gov (United States)

    Estacion, M; Choi, J S; Eastman, E M; Lin, Z; Li, Y; Tyrrell, L; Yang, Y; Dib-Hajj, S D; Waxman, S G

    2010-06-01

    Ion channel missense mutations cause disorders of excitability by changing channel biophysical properties. As an increasing number of new naturally occurring mutations have been identified, and the number of other mutations produced by molecular approaches such as in situ mutagenesis has increased, the need for functional analysis by patch-clamp has become rate limiting. Here we compare a patch-clamp robot using planar-chip technology with human patch-clamp in a functional assessment of a previously undescribed Nav1.7 sodium channel mutation, S211P, which causes erythromelalgia. This robotic patch-clamp device can increase throughput (the number of cells analysed per day) by 3- to 10-fold. Both modes of analysis show that the mutation hyperpolarizes activation voltage dependence (8 mV by manual profiling, 11 mV by robotic profiling), alters steady-state fast inactivation so that it requires an additional Boltzmann function for a second fraction of total current (approximately 20% manual, approximately 40% robotic), and enhances slow inactivation (hyperpolarizing shift--15 mV by human,--13 mV robotic). Manual patch-clamping demonstrated slower deactivation and enhanced (approximately 2-fold) ramp response for the mutant channel while robotic recording did not, possibly due to increased temperature and reduced signal-to-noise ratio on the robotic platform. If robotic profiling is used to screen ion channel mutations, we recommend that each measurement or protocol be validated by initial comparison to manual recording. With this caveat, we suggest that, if results are interpreted cautiously, robotic patch-clamp can be used with supervision and subsequent confirmation from human physiologists to facilitate the initial profiling of a variety of electrophysiological parameters of ion channel mutations.

  4. Design and fabrication of a planar patch-clamp substrate using a silicon-on-insulator wafer

    Science.gov (United States)

    Zhenlong, Zhang; Xiangyang, Liu; Yanli, Mao

    2009-09-01

    The planar patch-clamp technique has been applied to high throughput screening in drug discovery. The key feature of this technique is the fabrication of a planar patch-clamp substrate using appropriate materials. In this study, a planar patch-clamp substrate was designed and fabricated using a silicon-on-insulator (SOI) wafer. The access resistance and capacitance of SOI-based planar patch-clamp substrates are smaller than those of bulk silicon-based planar substrates, which will reduce the distributed RC noise.

  5. Discussion on compact mechanism of air-stream and synchro-formed clamp plate impact molding

    Directory of Open Access Journals (Sweden)

    Zhenling WANG

    2004-11-01

    Full Text Available Applying the air impact molding method to mold the complicated pattern with wider opening surface and deeper concave, there always exist vaulted phenomenon and lower compactibility of sand mold over the entrance and the concave regions. Using the air-stream and synchro-formed clamp plate impact molding, however, this problem will be preferably solved. In this paper, the compact mechanism of the new molding method and the effect of some configuration factors, such as the area flowed by compressed air and the highness of the protruding block displacement around the diffluent clamp plate, on the compactibility of sand mold were discussed.

  6. Experience of application of clamp-on cross-correlation flow meter in nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, Y. [Daystar Technology Inc., Ontario (Canada); Ton, V.; Kotenyov, S.; Zhao, C. [Ontario Power Generation, Ontario (Canada); Sharp, B.; Lopez, A. [Advanced Measurements and Analysis Group Inc., Ontario (Canada)

    2010-07-01

    The cross-correlation clamp-on flow meter, CROSSFLOW, developed and manufactured by AMAG, has been used over the world for over 15 years for flow measurements in various systems in nuclear and fossil power plants. Prior that, OPG has used similar technology in Canadian nuclear power plants since 1980-ies. Two recent examples of the application of the clamp-on cross-correlation technology are presented in this paper. In first example OPG meter was used to verify accuracy of ASME nozzles installed in condensate flow lines. In second example AMAG meter was used to measure Diesel Cooling Water (DCW). (author)

  7. Clamping drainage is unnecessary after minimally invasive total knee arthroplasty in patients with tranexamic acid

    Science.gov (United States)

    Wu, Yuangang; Yang, Timin; Zeng, Yi; Li, Canfeng; Shen, Bin; Pei, Fuxing

    2017-01-01

    Abstract Background: Drainage and tranexamic acid (TXA) have been widely used in total knee arthroplasty (TKA). However, it remains unclear whether it is necessary to clamp the drain after minimally invasive TKA (MIS-TKA) when TXA is used. We therefore conducted a randomized controlled trial to compare the effects of clamping versus not clamping drainage following MIS-TKA in patients in whom TXA was used. Methods: From January 2015 to December 2015, 121 patients undergoing unilateral primary MIS-TKA were enrolled and randomly divided into 2 groups. In the clamping group (N = 60), drainage was clamped for the 1st 4 postoperative hours. In the nonclamping group (N = 61), drainage was not clamped. All patients underwent a minimidvastus approach and received 10 mg/kg TXA intravenously before tourniquet deflation. We recorded the total blood loss, drainage volume, and transfusion requirements in the postoperative period. We also measured the hemoglobin (Hb) and hematocrit (Hct) levels on postoperative days 1, 3, and 5. Other factors, including range of motion (ROM), visual analog scale (VAS), and occurrence of wound-related complications, deep vein thrombosis (DVT), and pulmonary embolism (PE) were recorded at the time of discharge and 1 and 6 months postoperatively. No statistically significant differences were found between the 2 groups with regard to age, gender, weight, BMI, preoperative Hb and Hct levels, preoperative ROM, VAS, duration of surgery, anesthesia method, and the American Society of Anesthesiologists classification. Results: The clamping group experienced better drainage volume results than the nonclamping group (P < 0.001). There were no statistically significant differences in TBL and transfusion requirements (P = 0.105 and 0.276, respectively); Hb and Hct levels on postoperative days 1, 3, and 5 were similar between the 2 groups. No significant differences were found for ROM, VAS, DVT, PE, wound-related complications, and hospital

  8. 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

  9. 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.

  10. 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

  11. Predictors of inferior outcome in community acquired bacterial meningitis.

    Science.gov (United States)

    Streharova, A; Krcmery, V; Kisac, P; Kalavsky, E; Holeckova, K; Lesnakova, A; Luzinsky, L; Adamkovicova, E; Pavlikova, Z; Spilakova, N; Kacunova, B; Dovalova, V; Wiczmandyova, O; Spanik, S; Liskova, A; Chovancova, D; Kovac, M; Ondrusova, A; Bauer, F; Benca, J; Rudinsky, B; Sramka, M; Kralova, J; Krsakova, J; Krumpolcova, M; Findova, L; Svabova, V; Sladeckova, V; Seckova, S; Saniova, J; Pavlicova, B; Taziarova, M; Bukovinova, P; Kolenova, A; Horvathova, E; Hvizdak, F; Luzica, R; Rolnikova, B; Bocakova, A; Grey, E; Bielova, M; Huttova, M; Sabo, I; Jalili, N

    2007-11-01

    The aim of this study was to assess mortality and sequellae within cases from Nationwide survey of community acquired meningitis and identify risk factors for inferior outcome. Risk factors such as underlying disease (diabetes mellitus, cancer, trauma, neonatal age, splenectomy, alcoholism, sepsis, other infections), etiology, clinical symptoms and outcome (death, improvement and cured after modifications of ATB therapy, cured without change of therapy, cured with neurologic sequellae) were recorded and analysed with univariate analysis (chi2 or t test for trends, CDC Atlanta 2004). Analysing risk factors for inferior outcome (death or cured with neurologic sequellae), we compared patients who died or survived with neurologic sequellae to all patients with community acquired bacterial meningitis. Univariate analysis showed that trauma (palcohol abuse (pdiabetes, S. aureus (pdiabetes mellitus (palcoholism (palcohol abuse (p<0.05), craniocerbral trauma (p<0.05) and less common in meningitis with pneumococcal etiology (p<0.05).

  12. 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.

  13. Electronic thermography for the assessment of inferior alveolar nerve deficit.

    Science.gov (United States)

    Gratt, B M; Shetty, V; Saiar, M; Sickles, E A

    1995-08-01

    Neurosensory deficit is one of the major complications encountered in oral and maxillofacial surgery. OBJECTIVES. To determine the efficacy of electronic thermography in objectively assessing neurosensory deficits of the inferior alveolar nerve. STUDY DESIGN. Three studies were conducted measuring skin temperature over the chin region of the face at 0.1 degree C accuracy. RESULTS. (1) Thermal symmetry of the chin region in normal subjects (delta T = 0.2 degree C, SD = 0.02 degree C); (2) Induction of transient thermal asymmetry by local anesthetic injection (delta T = +0.4 degree C, SD = 0.2 degree C); (3) nine subjects with neurologic alterations of the inferior alveolar nerve (delta T = +0.5 degree C, SD = 0.2 degree C). Statistically significant differences were found between control group and experimental groups at p alveolar nerve injury or by pharmacologic nerve block.

  14. 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.

  15. Las alteraciones posturales en miembros inferiores en el surf

    OpenAIRE

    2015-01-01

    Cuando el equilibrio neuromuscular no es óptimo durante la práctica de un deporte, es posible que, a largo plazo, aparezcan trastornos posturales que, dependiendo del tiempo de entrenamiento, pueden convertirse en un obstáculo para la salud. Es por esto, que mediante esta investigación he pretendido mostrar las alteraciones posturales que el surf puede llegar a provocar en quienes lo practican. Objetivo: Analizar las alteraciones posturales en los miembros inferiores de surfist...

  16. Truncal ataxia from infarction involving the inferior olivary nucleus.

    Science.gov (United States)

    Park, Jae Hyun; Ryoo, Sookyung; Moon, So Young; Seo, Sand Won; Na, Duk L

    2012-08-01

    Truncal ataxia in medullary infarction may be caused by involvement of the lateral part of the medulla; however, truncal ataxia in infarction involving the inferior olivary nucleus (ION) has received comparatively little attention. We report a patient with truncal ataxia due to medial medullary infarction located in the ION. A lesion in the ION could produce a contralateral truncal ataxia due to increased inhibitory input to the contralesional vestibular nucleus from the contralesional flocculus.

  17. 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.

  18. 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.

  19. [Surgical treatment of leiomyosarcoma of the inferior vena cava].

    Science.gov (United States)

    Zotov, S P; Panov, I O; Tereshin, O S; Vazhenin, A V

    2012-01-01

    The presented review of the literature is generalization of the currently existing data of foreign and Russian literature concerning treatment of a rare non-organic retroperitoneal tumour from smooth-muscle tissue, i. e., leiomyosarcoma of the inferior vena cava. The authors also formulate and lay down the basic principles of surgical interventions depending on the scope and level of the lesion, as well statistical analysis of the outcomes of surgical management of the this severely ill patient cohort.

  20. 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.

  1. [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.

  2. Distal posterior inferior cerebellar artery aneurysm in a child

    Directory of Open Access Journals (Sweden)

    J. Francisco Salomão

    1992-06-01

    Full Text Available 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.

  3. 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

  4. Pulse and Trapezoidal Voltage Clamp Applied To Jurkat Cells: A T- Lymphocyte Cell Line

    Science.gov (United States)

    1993-04-01

    clamp. (Upward deflection represents depolarization). Low frequency oscillations are clearly visible. Such oscillations have been described by Maltsev ...1952. (8) Maltsev , V. A. Oscillating and triggering properties of T cell membrane potential. Imun. Lett. 26:277-282, 1990. 13 (9) Gallin, E. K

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  6. A Single-Strand Annealing Protein Clamps DNA to Detect and Secure Homology.

    Directory of Open Access Journals (Sweden)

    Marcel Ander

    2015-08-01

    Full Text Available Repair of DNA breaks by single-strand annealing (SSA is a major mechanism for the maintenance of genomic integrity. SSA is promoted by proteins (single-strand-annealing proteins [SSAPs], such as eukaryotic RAD52 and λ phage Redβ. These proteins use a short single-stranded region to find sequence identity and initiate homologous recombination. However, it is unclear how SSAPs detect homology and catalyze annealing. Using single-molecule experiments, we provide evidence that homology is recognized by Redβ monomers that weakly hold single DNA strands together. Once annealing begins, dimerization of Redβ clamps the double-stranded region and nucleates nucleoprotein filament growth. In this manner, DNA clamping ensures and secures a successful detection for DNA sequence homology. The clamp is characterized by a structural change of Redβ and a remarkable stability against force up to 200 pN. Our findings not only present a detailed explanation for SSAP action but also identify the DNA clamp as a very stable, noncovalent, DNA-protein interaction.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Avner eWallach

    2013-01-01

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

  9. 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...

  10. 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...

  11. 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 und...

  12. 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...

  13. 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

    for simultaneous patch clamping of cultured cells or neurons in the same network. A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work...

  14. A bulldog clamp that was forgotten during a coronary artery bypass operation 8 years ago.

    Science.gov (United States)

    Celkan, Mehmet Adnan; Bayatli, Kivanc

    2012-10-01

    Prevention of retained foreign bodies in the pericardial cavity is critical for patient safety. We report a patient with a bulldog clamp that was forgotten during a coronary artery bypass operation 8 years ago, which was detected by chance and removed.

  15. 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

  16. 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%.

  17. Thermographic assessment of reversible inferior alveolar nerve deficit.

    Science.gov (United States)

    Shetty, V; Gratt, B M; Flack, V

    1994-01-01

    The purpose of this study was to investigate thermography's potential as a diagnostic alternative for evaluating neurosensory deficits of the inferior alveolar nerve. Electronic thermography was used to evaluate the alterations in facial thermal patterns attendant to a conduction defect of the inferior alveolar nerve induced in 12 subjects using 2% lidocaine. The rates of onset and duration of sensory block, as visualized by thermography, were related to the results of conventional neurosensory testing. Comparison of the rate of response change within each measurement system revealed that changes in facial skin temperature manifest the induced deficit earlier than discriminative tests. Also, the prolonged elevation of thermal asymmetry suggested that electronic thermography has the ability to detect subtle changes in nerve function that are not discernible by physical neurosensory tests relying on patient response. Although cutaneous temperature increases were highest in the field of observation near the sensory distribution of the mental nerve, an inexplicable warming of the contralateral side of the face and neck was also observed. These attendant findings emphasize the need for further studies on the pathophysiologic mechanisms of facial thermal changes to better understand thermography's diagnostic accuracy and clinical utility for monitoring inferior alveolar nerve dysfunction.

  18. Inferior vestibular neuritis in a fighter pilot: a case report.

    Science.gov (United States)

    Xie, Su Jiang; Jia, Hong Bo; Xu, Po; Zheng, Ying Juan

    2013-06-01

    Spatial disorientation in airplane pilots is a leading factor in many fatal flying accidents. Spatial orientation is the product of integrative inputs from the proprioceptive, vestibular, and visual systems. One condition that can lead to sudden pilot incapacitation in flight is vestibular neuritis. Vestibular neuritis is commonly diagnosed by a finding of unilateral vestibular failure, such as a loss of caloric response. However, because caloric response testing reflects the function of only the superior part of the vestibular nerve, it cannot detect cases of neuritis in only the inferior part of the nerve. We describe the case of a Chinese naval command fighter pilot who exhibited symptoms suggestive of vestibular neuritis but whose caloric response test results were normal. Further testing showed a unilateral loss of vestibular evoked myogenic potentials (VEMPs). We believe that this pilot had pure inferior nerve vestibular neuritis. VEMP testing plays a major role in the diagnosis of inferior nerve vestibular neuritis in pilots. We also discuss this issue in terms of aeromedical concerns.

  19. Intraosseous schwannoma originating in inferior alveolar nerve: a case report.

    Science.gov (United States)

    Suga, Kenichiro; Ogane, Satoru; Muramatsu, Kyotaro; Ohata, Hitoshi; Uchiyama, Takeshi; Takano, Nobuo; Shibahara, Takahiko; Eguchi, Jun; Murakami, Satoshi; Matsuzaka, Kenichi

    2013-01-01

    Schwannomas (neurilemmomas) are benign neoplasms derived from Schwann cells of the neurilemma and appear most frequently on the auditory nerve or peripheral nerves of the skin. They arise in the oral and maxillofacial region infrequently, and very rarely in the center of the jaw. We herein present a case of a rare mandibular intraosseous schwannoma derived from the main trunk of the inferior alveolar nerve in a 33-year-old man. Fusiform expansion in the mandibular canal was observed and a mass showing the target sign in the mandibular canal was confirmed on T2-weighted and Gd contrastenhanced T1-weighted MRI. Based on these findings, an inferior alveolar nerve-derived schwannoma or other benign nervous system neoplasm was diagnosed. A buccal side cortical bone flap in the mandibular molar region was removed to expose the mass, which was then peeled away from the nerve fibers and completely removed. Some inferior alveolar nerve fibers that were connected to the mass were removed at the same time, but the remaining nerve fiber bundle was preserved. Histopathology confirmed the diagnosis of a schwannoma with Antoni type A and Antoni type B regions. Although the patient experienced extremely mild paresthesia in the skin over the mental region and mental foramen at immediately after surgery, this had almost entirely disappeared at 7 years and 4 months later, and there has been no tumor recurrence.

  20. [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.

  1. 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...

  2. An AFM-based stiffness clamp for dynamic control of rigidity.

    Science.gov (United States)

    Webster, Kevin D; Crow, Ailey; Fletcher, Daniel A

    2011-03-08

    Atomic force microscopy (AFM) has become a powerful tool for measuring material properties in biology and imposing mechanical boundary conditions on samples from single molecules to cells and tissues. Constant force or constant height can be maintained in an AFM experiment through feedback control of cantilever deflection, known respectively as a 'force clamp' or 'position clamp'. However, stiffness, the third variable in the Hookean relation F = kx that describes AFM cantilever deflection, has not been dynamically controllable in the same way. Here we present and demonstrate a 'stiffness clamp' that can vary the apparent stiffness of an AFM cantilever. This method, employable on any AFM system by modifying feedback control of the cantilever, allows rapid and reversible tuning of the stiffness exposed to the sample in a way that can decouple the role of stiffness from force and deformation. We demonstrated the AFM stiffness clamp on two different samples: a contracting fibroblast cell and an expanding polyacrylamide hydrogel. We found that the fibroblast, a cell type that secretes and organizes the extracellular matrix, exhibited a rapid, sub-second change in traction rate (dF/dt) and contraction velocity (dx/dt) in response to step changes in stiffness between 1-100 nN/µm. This response was independent of the absolute contractile force and cell height, demonstrating that cells can react directly to changes in stiffness alone. In contrast, the hydrogel used in our experiment maintained a constant expansion velocity (dx/dt) over this range of stiffness, while the traction rate (dF/dt) changed with stiffness, showing that passive materials can also behave differently in different stiffness environments. The AFM stiffness clamp presented here, which is applicable to mechanical measurements on both biological and non-biological samples, may be used to investigate cellular mechanotransduction under a wide range of controlled mechanical boundary conditions.

  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. Differences in synaptic and intrinsic properties result in topographic heterogeneity of temporal processing of neurons within the inferior colliculus.

    Science.gov (United States)

    Yassin, Lina; Pecka, Michael; Kajopoulos, Jasmin; Gleiss, Helge; Li, Lu; Leibold, Christian; Felmy, Felix

    2016-11-01

    The identification and characterization of organization principals is essential for the understanding of neural function of brain areas. The inferior colliculus (IC) represents a midbrain nexus involved in numerous aspects of auditory processing. Likewise, neurons throughout the IC are tuned to a diverse range of specific stimulus features. Yet beyond a topographic arrangement of the cochlea-inherited frequency tuning, the functional organization of the IC is not well understood. Particularly, a common principle that links the diverse tuning characteristics is unknown. Here we used in vitro patch clamp recordings combined with laser-uncaging, and in vivo single cell recordings to study the spatial and functional organization principles of the central IC. We identified a topographic bias of ascending synaptic input timing that is balanced between inhibition and excitation and co-varies with in vivo first-spike latency. This bias was paralleled post-synaptically by differences in biophysical membrane properties and firing patterns, with integrating neurons predominantly found in the dorso-medial part, and coincidence-detector neurons biased to the ventro-lateral IC. Importantly, these cellular and network features translated into distinct temporal processing capabilities irrespectively of the neurons' characteristic frequency. Our data therefore imply that heterogeneity of synaptic inputs, intrinsic properties and temporal processing are functional principles that underlie the spatial organization of the central IC.

  5. 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

  6. MATLAB implementation of a dynamic clamp with bandwidth >125 KHz capable of generating INa at 37°C

    Science.gov (United States)

    Clausen, Chris; Valiunas, Virginijus; Brink, Peter R.; Cohen, Ira S.

    2012-01-01

    We describe the construction of a dynamic clamp with bandwidth >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, 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 (INa) 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: INa, the hyperpolarizing-activated inward pacemaker current (If), and an inward-rectifier K+ current (IK1). 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

  7. Induction of DNA DSB and its rejoining in clamped and non-clamped tumours after exposure to carbon ion beams in comparison to X rays.

    Science.gov (United States)

    Hirayama, R; Uzawa, A; Matsumoto, Y; Noguchi, M; Kase, Y; Takase, N; Ito, A; Koike, S; Ando, K; Okayasu, R; Furusawa, Y

    2011-02-01

    We studied double-strand breaks (DSB) induction and rejoining in clamped and non-clamped transplanted tumours in mice leg after exposure to 80 keV µm(-1) carbon ions and X rays. The yields of DSB in the tumours were analysed by a static-field gel electrophoresis. The OER of DSB after X rays was 1.68±0.31, and this value was not changed after 1 h rejoining time (1.40±0.26). These damages in oxygenated conditions were rejoined 60-70% within 1 h in situ. No difference was found between the exposure to X rays and carbon ions for the induction and rejoining of DSB. Thus, the values of OER and rejoined fraction after exposure to carbon ions were similar to those after X rays, and the calculated relative biological effectivenesses of carbon ion were around 1 under both oxygen conditions. The yields of DSB in vivo depend on exposure doses, oxygen conditions and rejoining time, but not on the types of radiation quality.

  8. Hemianopsia altitudinal inferior por aracnoidite optoquiasmática

    Directory of Open Access Journals (Sweden)

    R. Melaragno Filho

    1949-09-01

    Full Text Available Os autores relatam o caso de um paciente de 48 anos de idade, queixando-se de falta de visão nas metades inferiores dos campos visuais, há aproximadamente um ano. A doença evoluiu progressivamente após sinusotomia maxilar e frontal. Os diversos exames complementares realizados nada revelaram de anormal. Reação de Wassermann sempre negativa no sangue. Ao exame oftalmoscópico ficou patenteado, em AO, franca atrofia, no setor superior das papilas e edema pronunciado em suas metades inferiores. O exame campimétrico revelou nítida hemianopsia altitudinal inferior. As demais funções neurológicas e o exame clínico geral nada mais demonstraram de anormal. A iodoventriculografia evidenciou sinais radiológicos de aracnoidite optoquiasmática. À intervenção cirúrgica, foi verificada a existência de aracnoidite intensa na região quiasmática, com compressão dos nervos ópticos e do próprio quiasma. Após a intervenção cirúrgica, exames oftalmoscópicos sucessivos demonstraram melhora franca da acuidade visual em AO e discreto aumento dos campos visuais. Finalizando, os AA. tecem considerações sôbre as prováveis causas etiológicas dêsse tipo de reação meníngea.

  9. 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.

  10. Duplicate inferior vena cava filters: more is not always better.

    Science.gov (United States)

    Katyal, Anup; Javed, Muhammad Ali

    2016-01-01

    Duplication of the inferior vena cava (IVC) has been reported in literature. This achieves clinical significance in the setting of lower extremity venous thromboembolism with a contraindication for anticoagulation. We describe a case of lower extremity deep vein thrombosis with duplicate IVC. Anticoagulation was contraindicated in this case leading to successful treatment with double IVC filters. We conducted a PubMed search for all current English language published literature, where filters were placed in the presence of duplicate IVC. We suggest that patients with deep vein thrombosis should have an accurate assessment of venous anatomy before IVC filter placement. Duplication of IVC, although rare, should be considered as this has management implications.

  11. 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.

  12. Amiloidosis renal en paciente con osteomielitis de extremidad inferior

    Directory of Open Access Journals (Sweden)

    María Vicente Santos

    2012-09-01

    Full Text Available La amiloidosis secundaria (AA sistémica es una entidad frecuente, asociada con enfermedades inflamatorias e infecciones de larga evolución, así como con algunas neoplasias. Presentamos el caso de un varón de 58 años, con antecedente de úlcera en miembro inferior derecho de más de 30 años de evolución y con síndrome nefrótico secundario a amiloidosis AA.

  13. Inferior alveolar nerve paresthesia relieved by microscopic endodontic treatment.

    Science.gov (United States)

    Yatsuhashi, Takaaki; Nakagawa, Kan-Ichi; Matsumoto, Miho; Kasahara, Masataka; Igarashi, Tomoko; Ichinohe, Tatsuya; Kaneko, Yuzuru

    2003-11-01

    We experienced two cases of inferior alveolar nerve paresthesia caused by root canal medicaments, which were successfully relieved by microscopic endodontic treatment. In the first case, the paresthesia might have been attributable to infiltration of calcium hydroxide into the mandibular canal through the root canals of the mandibular left second molar tooth. In the second case, the paresthesia might have been attributable to infiltration of paraformaldehyde through the root canals of the mandibular right second molar tooth. The paresthesia was relieved in both cases by repetitive microscopic endodontic irrigation using physiological saline solution in combination with oral vitamin B12 and adenosine triphosphate.

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

    Science.gov (United States)

    Koeth, Oliver; Zeymer, Uwe; Schiele, Rudolf; Zahn, Ralf

    2010-01-01

    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. PMID:20811565

  15. 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.

  16. 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.

  17. Inferior epigastric artery: Surface anatomy, prevention and management of injury.

    Science.gov (United States)

    Wong, Clare; Merkur, Harry

    2016-04-01

    The anatomical position of the inferior epigastric artery (IEA) subjects it to risk of injury during abdominal procedures that are close to the artery, such as laparoscopic trocar insertion, insertion of intra-abdominal drains, Tenckhoff(®) catheter (peritoneal dialysis catheter) and paracentesis. This article aims to raise the awareness of the anatomical variations of the course of the IEA in relation to abdominal landmarks in order to define a safer zone for laparoscopic ancillary trocar placement. Methods of managing the IEA injury as well as techniques to minimise the risk of injury to the IEA are reviewed and discussed.

  18. 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.

  19. Tuberculosis pulmonar de campos inferiores Lower lung field tuberculosis

    OpenAIRE

    Alejandra González; Marcelo Fernández Casares; Matías Baldini; Alfredo Monteverde

    2010-01-01

    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 loc...

  20. 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.

  1. Implementation and Tuning of an Optical Tweezers Force-Clamp Feedback System.

    Science.gov (United States)

    Bugiel, Michael; Jannasch, Anita; Schäffer, Erik

    2017-01-01

    Feedback systems can be used to control the value of a system variable. In optical tweezers, active feedback is often implemented to either keep the position or tension applied to a single biomolecule constant. Here, we describe the implementation of the latter: an optical force-clamp setup that can be used to study the motion of processive molecular motors under a constant load. We describe the basics of a software-implemented proportional-integral-derivative (PID) controller, how to tune it, and how to determine its optimal feedback rate. Limitations, possible feed-forward applications, and extensions into two- and three-dimensional optical force clamps are discussed. The feedback is ultimately limited by thermal fluctuations and the compliance of the involved molecules. To investigate a particular mechanical process, understanding the basics and limitations of the feedback system will be helpful for choosing the proper feedback hardware, for optimizing the system parameters, and for the design of the experiment.

  2. 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

  3. [Traumatic section of the thoracic aorta: its repair by direct aortic clamping].

    Science.gov (United States)

    Cairols, M A; Sieyro, F; Miralles, M; Blanes, I; Lozano, P

    1991-01-01

    Traumatic section of descendent aorta, severe complication of a thoracic traumatism, requires an early recognition and restoration because its high mortality rate. Between 1988 and 1990, three patients underwent surgical approach, by direct aortic clamping [correction of clamplaje], at our Service. In two cases, a heart stoppage appeared during the clamping/unclamping [correction of clampaje/desclampaje] maneuvers. One of them had previously electrocardiographic abnormalities, suggestive of heart contusion. Two patients died, one of them during surgical procedure because an irreversible heart stoppage, and the second patient died after 7 days because of a brain hemorrhage. One case presented postoperative paraplegia. Respective rates and literature about the main factors implicated in the diagnosis and treatment of such pathology are reviewed.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Conformal analysis of fundamental frequency of vibration of elastic clamped plates

    Institute of Scientific and Technical Information of China (English)

    QI Hongyuan; ZHU Hengjun

    2007-01-01

    To calculate the fundamental frequency of vibration of special-shaped and elastic clamped plates, the conformal mapping theory is adopted to separate the interpolating points of a complicated boundary into odd and even sequences,both of which can be mutually iterated, so that the conformal mapping function between the complicated region and the unit dish region is established. Trigonometric interpolation and convergence along the normal direction methods are provided, and the complex coefficients of the conformal mapping function are calculated. Galerkin method is used to obtain the solution of fundamental frequency in the vibrating differential function of the complicated vibrating region.Finally, taking ellipse elastic clamped plates as an example,the effects on fundamental frequency coefficient caused by eccentric ratio e and area size are analyzed.

  9. MATLAB-based automated patch-clamp system for awake behaving mice

    OpenAIRE

    Desai, Niraj S.; Siegel, Jennifer J.; Taylor, William; Chitwood, Raymond A.; Johnston, Daniel

    2015-01-01

    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 th...

  10. 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.

  11. Generation of high-performance binding proteins for peptide motifs by affinity clamping

    OpenAIRE

    Koide, Shohei; Huang, Jin

    2013-01-01

    We describe concepts and methodologies for generating “Affinity Clamps”, a new class of recombinant binding proteins that achieve high affinity and high specificity toward short peptide motifs of biological importance, which is a major challenge in protein engineering. The Affinity Clamping concept exploits the potential of nonhomologous recombination of protein domains in generating large changes in protein function and the inherent binding affinity and specificity of the so-called modular i...

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    literature. Addressing the afore-described issues, this paper focuses on the operational mode analysis of a three-level sparse matrix converter implemented using a neutral-point-clamped inversion stage, and  the design of a number of PWM and modulation ratio compensation schemes for controlling the converter...... with improved waveform quality. Performances and practicalities of the designed schemes are verified in simulation and experimentally using an implemented laboratory prototype with some representative results captured and presented in the paper....

  13. Adverse impact of intermittent portal clamping on long-term postoperative outcomes in hepatocellular carcinoma.

    Science.gov (United States)

    Hao, S; Chen, S; Yang, X; Wan, C

    2017-01-01

    Introduction To evaluate the impact of intermittent portal clamping (IPC) on long-term postoperative outcomes in patients with hepatocellular carcinoma (HCC). Methods Clinical records of 355 patients underwent curative liver resection for HCC in January 2007 to December 2010 were retrospectively reviewed. According to how portal clamping was performed, patients were grouped as: IPC, n=113; other portal clamping (OPC), n=190; and no portal clamping (NPC), n=52. Results Median recurrence-free survival (RFS) was statistically significantly shorter in the IPC (39.4 months) than OPC (47.3 months, p=0.010) and NPC groups (51.4 months, p=0.008). Median overall survival (OS) was also significantly shorter with IPC (46.3 months), versus 52.9 months with OPC (p=0.022) and 56.2 months with NPC (p=0.015). Kaplan-Meier survival analysis revealed that 5-year cumulative RFS was much lower in the IPC (42.5%) than OPC (50.9%, p=0.014) and NPC groups (49.6%, p=0.013). Five-year cumulative OS was also much lower in the IPC (44.9%) than OPC (58.0%, p=0.020) and NPC groups (57.7%, p=0.025). On univariate analysis, tumour grade, size and number, TNM stage, blood transfusion, vascular invasion and IPC were significantly inversely correlated with RFS and OS. On multivariate analysis, tumour size and number, blood transfusion, vascular invasion and IPC remained significant. Conclusions Our study suggests that IPC is an independent risk factor for poor long-term postoperative outcomes in patients with HCC.

  14. 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.

  15. 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....

  16. New device for saphenous vein-to-aorta proximal anastomosis without side-clamping

    Directory of Open Access Journals (Sweden)

    Tappainer Ernesto

    2007-05-01

    Full Text Available Abstract Background Side clamping to perform saphenous vein-to-aorta proximal anastomosis is a well known cause of cerebral embolization during coronary bypass surgery. Automatic and manual devices have been introduced to avoid aortic clamping and facilitate proximal anastomosis but the manual ones only allow the traditional hand-sewing running suture. Nevertheless, they are not easy to use and very expensive to buy. Methods We developed a simple object that helps to perform a manual proximal anastomosis without the need to clamp the side of the aorta. This device is a steel bar which blocks the aortic hole and simultaneously it provides a slit to receive the needle. Through the slit comes out a thin, sharp, straight, but also well directed and predictable jet of blood which could be easily controlled during the suture. Results The function of the object is quite different from other devices. Nothing is deployed in the aorta. The object is only placed on the aorta with the small appendage slipped into the hole. The main advantage of the device is that while manipulation of the aorta is avoided no foreign bodies are incorporated in the suture and – most importantly – the aortic intima is not touched at all. The main drawback of the device is the blood jet coming from the slit so that the blood pressure has to be lowered by vasodilators during the anastomosis. Moreover, the suture has to change direction and the needle has to enter the aortic wall first to slip out through the slit. Conclusion The object was named "Slit Device" and is not a routine instrument. It would be only an alternative to other anastomotic devices with the same surgical indications. In the case of ascending aortic disease and saphenous vein grafting, the Slit Device avoids aortic clamping thereby preventing atheroembolism and also avoiding the need for hypothermic circulatory arrest in patients with unclampable aorta.

  17. A complete dc characterization of a constant-frequency, clamped-mode, series-resonant converter

    Science.gov (United States)

    Tsai, Fu-Sheng; Lee, Fred C.

    1988-01-01

    The dc behavior of a clamped-mode series-resonant converter is characterized systematically. Given a circuit operating condition, the converter's mode of operation is determined and various circuit parameters are calculated, such as average inductor current (load current), rms inductor current, peak capacitor voltage, rms switch currents, average diode currents, switch turn-on currents, and switch turn-off currents. Regions of operation are defined, and various circuit characteristics are derived to facilitate the converter design.

  18. Monopolar intracochlear pulse trains selectively activate the inferior colliculus.

    Science.gov (United States)

    Schoenecker, Matthew C; Bonham, Ben H; Stakhovskaya, Olga A; Snyder, Russell L; Leake, Patricia A

    2012-10-01

    Previous cochlear implant studies using isolated electrical stimulus pulses in animal models have reported that intracochlear monopolar stimulus configurations elicit broad extents of neuronal activation within the central auditory system-much broader than the activation patterns produced by bipolar electrode pairs or acoustic tones. However, psychophysical and speech reception studies that use sustained pulse trains do not show clear performance differences for monopolar versus bipolar configurations. To test whether monopolar intracochlear stimulation can produce selective activation of the inferior colliculus, we measured activation widths along the tonotopic axis of the inferior colliculus for acoustic tones and 1,000-pulse/s electrical pulse trains in guinea pigs and cats. Electrical pulse trains were presented using an array of 6-12 stimulating electrodes distributed longitudinally on a space-filling silicone carrier positioned in the scala tympani of the cochlea. We found that for monopolar, bipolar, and acoustic stimuli, activation widths were significantly narrower for sustained responses than for the transient response to the stimulus onset. Furthermore, monopolar and bipolar stimuli elicited similar activation widths when compared at stimulus levels that produced similar peak spike rates. Surprisingly, we found that in guinea pigs, monopolar and bipolar stimuli produced narrower sustained activation than 60 dB sound pressure level acoustic tones when compared at stimulus levels that produced similar peak spike rates. Therefore, we conclude that intracochlear electrical stimulation using monopolar pulse trains can produce activation patterns that are at least as selective as bipolar or acoustic stimulation.

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

    Directory of Open Access Journals (Sweden)

    P.J.S. Praveen,

    2015-11-01

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

  20. Low noise patch-clamp current amplification by nanoparticles plasmonic-photonic coupling (analysis and modelling).

    Science.gov (United States)

    Haberal, E O; SalmanOgli, A; Nasseri, B

    2016-10-01

    In this article, a patch-clamp low noise current amplification based on nanoparticles plasmonic radiation is analyzed. It is well-known, a very small current is flowing from different membrane channels and so, for extra processing the current amplification is necessary. It is notable that there are some problems in traditional electronic amplifier due to its noise and bandwidth problem. Because of the important role of the patch-clamp current in cancer research and especially its small amplitude, it is vital to intensify it without adding any noises. In this study, the current amplification is performed firstly: from the excitement of nanoparticles by the patch-clamp pico-ampere current and then, the effect of nanoparticles plasmonic far-field radiation on conductor's carriers, which will cause the current amplification. This relates to the plasmonic-photonic coupling and their effect on conductor carriers as the current perturbation agent. In the steady state, the current amplification can reach to 1000 times of initial level. Furthermore, we investigated the nanoparticles morphology changing effect such as size, nanoparticles inter-distance, and nanoparticles distance from the conductor on the amplifier parameters. Finally, it should note that the original aim is to use nanoparticles plasmonic engineering and their coupling to photonics for output current manipulating.

  1. 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.

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

    Science.gov (United States)

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

    2011-02-01

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

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

    Directory of Open Access Journals (Sweden)

    V. Ranjith Kumar

    2013-09-01

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

  4. 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.

  5. Voltage- and space-clamp errors associated with the measurement of electrotonically remote synaptic events.

    Science.gov (United States)

    Spruston, N; Jaffe, D B; Williams, S H; Johnston, D

    1993-08-01

    1. The voltage- and space-clamp errors associated with the use of a somatic electrode to measure current from dendritic synapses are evaluated using both equivalent-cylinder and morphologically realistic models of neuronal dendritic trees. 2. As a first step toward understanding the properties of synaptic current distortion under voltage-clamp conditions, the attenuation of step and sinusoidal voltage changes are evaluated in equivalent cylinder models. Demonstration of the frequency-dependent attenuation of voltage in the cable is then used as a framework for understanding the distortion of synaptic currents generated at sites remote from the somatic recording electrode and measured in the voltage-clamp recording configuration. 3. Increases in specific membrane resistivity (Rm) are shown to reduce steady-state voltage attenuation, while producing only minimal reduction in attenuation of transient voltage changes. Experimental manipulations that increase Rm therefore improve the accuracy of estimates of reversal potential for electrotonically remote synapses, but do not significantly reduce the attenuation of peak current. In addition, increases in Rm have the effect of slowing the kinetics of poorly clamped synaptic currents. 4. The effects of the magnitude of the synaptic conductance and its kinetics on the measured synaptic currents are also examined and discussed. The error in estimating parameters from measured synaptic currents is greatest for synapses with fast kinetics and large conductances. 5. A morphologically realistic model of a CA3 pyramidal neuron is used to demonstrate the generality of the conclusions derived from equivalent cylinder models. The realistic model is also used to fit synaptic currents generated by stimulation of mossy fiber (MF) and commissural/associational (C/A) inputs to CA3 neurons and to estimate the amount of distortion of these measured currents. 6. Anatomic data from the CA3 pyramidal neuron model are used to construct a

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Gintaras Juodzbalys

    2011-01-01

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

  8. Properties of the Nucleo-Olivary Pathway: An In Vivo Whole-Cell Patch Clamp Study

    NARCIS (Netherlands)

    P. Bazzigaluppi (Paolo); T.J.H. Ruigrok (Tom); P. Saisan (Payam); C.I. de Zeeuw (Chris); M.T.G. de Jeu (Marcel)

    2012-01-01

    textabstractThe inferior olivary nucleus (IO) forms the gateway to the cerebellar cortex and receives feedback information from the cerebellar nuclei (CN), thereby occupying a central position in the olivo-cerebellar loop. Here, we investigated the feedback input from the CN to the IO in vivo in mic

  9. Conformational analysis of processivity clamps in solution demonstrates that tertiary structure does not correlate with protein dynamics.

    Science.gov (United States)

    Fang, Jing; Nevin, Philip; Kairys, Visvaldas; Venclovas, Ceslovas; Engen, John R; Beuning, Penny J

    2014-04-08

    The relationship between protein sequence, structure, and dynamics has been elusive. Here, we report a comprehensive analysis using an in-solution experimental approach to study how the conservation of tertiary structure correlates with protein dynamics. Hydrogen exchange measurements of eight processivity clamp proteins from different species revealed that, despite highly similar three-dimensional structures, clamp proteins display a wide range of dynamic behavior. Differences were apparent both for structurally similar domains within proteins and for corresponding domains of different proteins. Several of the clamps contained regions that underwent local unfolding with different half-lives. We also observed a conserved pattern of alternating dynamics of the α helices lining the inner pore of the clamps as well as a correlation between dynamics and the number of salt bridges in these α helices. Our observations reveal that tertiary structure and dynamics are not directly correlated and that primary structure plays an important role in dynamics.

  10. Tools for electrophysiology labs: a C coded dynamic-clamp on DSP board (aC/DC).

    OpenAIRE

    Boussa, Sofiane; Pasquier, Jennifer; Leboulenger, Francois; Le Foll, Frank; Faure, Alain

    2008-01-01

    ISBN : 978-2-9532965-0-1; Dynamic-clamp represents an archetypal interdisciplinary approach in the field of computational neuroscience because it aims at establishing a dialog in real time between i) a numerical model and a spiking cell and ii) between neurobiologists and computer programmers. In this paper, we present a relative simple hardware solution for an efficient dynamic-clamp application. The prototype has been built around a DSP board (dsPIC 33F, Microchip INC). Our results demonstr...

  11. Preservation of the recipient inferior vena cava in liver transplantation.

    Science.gov (United States)

    Pereira, F; Herrera, J; Mora, N P; Nuño, J; Turrión, V S; Vicente, E; Ardaiz, J

    1994-01-01

    Twenty piggy-back (PB) liver transplantations (LT) were compared with 20 LT performed by the standard technique in order to evaluate whether or not the theoretical haemodynamic advantages of the preservation of the inferior vena cava (IVC) have any impact on the final results of the LT. Statistically significant differences were observed in the duration of the hepatectomy, which was longer for PB LT (192 min vs. 146 min), and in the duration of the anhepatic phase, which was shorter in that group (52 min vs. 76 min). There were no differences in the duration of the complete surgical procedure, consumption of blood products, incidence of postoperative acute renal failure, number of reoperations or survival.

  12. 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.

  13. 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.

  14. 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.

  15. Electrophysiological properties of inferior olive neurons: A compartmental model.

    Science.gov (United States)

    Schweighofer, N; Doya, K; Kawato, M

    1999-08-01

    As a step in exploring the functions of the inferior olive, we constructed a biophysical model of the olivary neurons to examine their unique electrophysiological properties. The model consists of two compartments to represent the known distribution of ionic currents across the cell membrane, as well as the dendritic location of the gap junctions and synaptic inputs. The somatic compartment includes a low-threshold calcium current (I(Ca_l)), an anomalous inward rectifier current (I(h)), a sodium current (I(Na)), and a delayed rectifier potassium current (I(K_dr)). The dendritic compartment contains a high-threshold calcium current (I(Ca_h)), a calcium-dependent potassium current (I(K_Ca)), and a current flowing into other cells through electrical coupling (I(c)). First, kinetic parameters for these currents were set according to previously reported experimental data. Next, the remaining free parameters were determined to account for both static and spiking properties of single olivary neurons in vitro. We then performed a series of simulated pharmacological experiments using bifurcation analysis and extensive two-parameter searches. Consistent with previous studies, we quantitatively demonstrated the major role of I(Ca_l) in spiking excitability. In addition, I(h) had an important modulatory role in the spike generation and period of oscillations, as previously suggested by Bal and McCormick. Finally, we investigated the role of electrical coupling in two coupled spiking cells. Depending on the coupling strength, the hyperpolarization level, and the I(Ca_l) and I(h) modulation, the coupled cells had four different synchronization modes: the cells could be in-phase, phase-shifted, or anti-phase or could exhibit a complex desynchronized spiking mode. Hence these simulation results support the counterintuitive hypothesis that electrical coupling can desynchronize coupled inferior olive cells.

  16. A conserved physical and functional interaction between the cell cycle checkpoint clamp loader and DNA ligase I of eukaryotes.

    Science.gov (United States)

    Song, Wei; Levin, David S; Varkey, Johnson; Post, Sean; Bermudez, Vladimir P; Hurwitz, Jerard; Tomkinson, Alan E

    2007-08-03

    DNA ligase I joins Okazaki fragments during DNA replication and completes certain excision repair pathways. The participation of DNA ligase I in these transactions is directed by physical and functional interactions with proliferating cell nuclear antigen, a DNA sliding clamp, and, replication factor C (RFC), the clamp loader. Here we show that DNA ligase I also interacts with the hRad17 subunit of the hRad17-RFC cell cycle checkpoint clamp loader, and with each of the subunits of its DNA sliding clamp, the heterotrimeric hRad9-hRad1-hHus1 complex. In contrast to the inhibitory effect of RFC, hRad17-RFC stimulates joining by DNA ligase I. Similar results were obtained with the homologous Saccharomyces cerevisiae proteins indicating that the interaction between the replicative DNA ligase and checkpoint clamp is conserved in eukaryotes. Notably, we show that hRad17 preferentially interacts with and specifically stimulates dephosphorylated DNA ligase I. Moreover, there is an increased association between DNA ligase I and hRad17 in S phase following DNA damage and replication blockage that occurs concomitantly with DNA damage-induced dephosphorylation of chromatin-associated DNA ligase I. Thus, our results suggest that the in vivo interaction between DNA ligase I and the checkpoint clamp loader is regulated by post-translational modification of DNA ligase I.

  17. Blunt injury to the inferior gluteal artery: case report of a rare "near miss" event

    OpenAIRE

    Chen Wei; Pan Jinshe; Smith Wade R; Liu Huaijun; Zhang Qi; Zhang Yingze

    2008-01-01

    Abstract Traumatic injuries of the inferior gluteal artery are rare, the majority of which are aneurysms due to sharp or blunt trauma. We report the rare case of a "near miss" event of a patient with an acute hemorrhagic mass in the right buttock caused by blunt trauma to the inferior gluteal artery without "hard" clinical signs of vascular injury. Despite the unusual presentation, diffuse injury of the inferior gluteal artery branches was diagnosed by ultrasonography and angiography. This ar...

  18. Spiral CT in aplasia of the pre-renal inferior vena cava as a cause of phlebothrombosis from the femoral veins to the inferior vena cava; Spiral-CT einer Aplasie der praerenalen Vena cava inferior als Ursache einer Phlebothrombose von den Oberschenkelvenen bis in die Vena cava inferior

    Energy Technology Data Exchange (ETDEWEB)

    Schweiger, U. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schedel, H. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Thiede, U. [Deutsches Herzzentrum Berlin (Germany). Arbeitsgruppe Digitale Bildbearbeitung; Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1994-12-31

    The case report focuses on the computed tomography of the thrombotic okklusion of the inferior vena cava, venae iliacae and femorales communes due to congenital interruption of the prerenal inferior vena cava. The embryology of the abnormality was discussed. (orig.) [Deutsch] Anhand einer Fallstudie wurden die Moeglichkeiten der computertomographischen Diagnostik bei einer durch Teilplasie der `praerenalen` Vena cava inferior hervorgerufenen Thrombose der Vv. femorales superficiales et profundae, der grossen Beckenvenen und der Vena cava inferior erlaeutert. In der Diskussion wurde auf die Embryologie der Missbildung eingegangen. (orig.)

  19. Transition from fetal to neonatal circulation: Modeling the effect of umbilical cord clamping.

    Science.gov (United States)

    Yigit, Mehmet B; Kowalski, William J; Hutchon, David J R; Pekkan, Kerem

    2015-06-25

    Hemodynamics of the fetal to neonatal transition are orchestrated through complex physiological changes and results in cardiovascular adaptation to the adult biventricular circulation. Clinical practice during this critical period can influence vital organ physiology for normal newborns, premature babies and congenital heart defect patients. Particularly, the timing of the cord clamping procedure, immediate (ICC) vs. delayed cord clamping (DCC), is hypothesized to be an important factor for the transitory fetal hemodynamics. The clinical need for a quantitative understanding of this physiology motivated the development of a lumped parameter model (LPM) of the fetal cardio-respiratory system covering the late-gestation to neonatal period. The LPM was validated with in vivo clinical data and then used to predict the effects of cord clamping procedures on hemodynamics and vital gases. Clinical time-dependent resistance functions to simulate the vascular changes were introduced. For DCC, placental transfusion (31.3 ml) increased neonatal blood volume by 11.7%. This increased blood volume is reflected in an increase in preload pressures by ~20% compared to ICC, which in turn increased the cardiac output (CO) by 20% (COICC=993 ml/min; CODCC=1197 ml/min). Our model accurately predicted dynamic flow patterns in vivo. DCC was shown to maintain oxygenation if the onset of pulmonary respiration was delayed or impaired. On the other hand, a significant 25% decrease in oxygen saturations was observed when applying ICC under the same physiological conditions. We conclude that DCC has a significant impact on newborn hemodynamics, mainly because of the improved blood volume and the sustained placental respiration.

  20. 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.

  1. 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...

  2. 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

  3. 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.

  4. 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 the erbium-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.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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)

  10. 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.

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

    Science.gov (United States)

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

    1992-01-01

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

  12. Characterization of the IEC 61000-4-6 Electromagnetic Clamp for Conducted-Immunity Testing

    Science.gov (United States)

    Grassi, F.; Pignari, S. A.; Spadacini, G.; Toscani, N.; Pelissou, P.

    2016-05-01

    A multiconductor transmission line model (MTL) is used to investigate the operation of the IEC 61000-4-6 electromagnetic (EM) clamp in a conducted-immunity test setup for aerospace applications. Aspects of interest include the performance of such a coupling device at very high frequencies (up to 1 GHz), and for extreme values of the common-mode impedance of equipment (short circuits, open circuits). The MTL model is finally exploited to predict the frequency response of coupling and decoupling factors defined in the IEC 61000-4-6 standard.

  13. The Elg1 Clamp Loader Plays a Role in Sister Chromatid Cohesion

    OpenAIRE

    Oren Parnas; Adi Zipin-Roitman; Yuval Mazor; Batia Liefshitz; Shay Ben-Aroya; Martin Kupiec

    2009-01-01

    Mutations in the ELG1 gene of yeast lead to genomic instability, manifested in high levels of genetic recombination, chromosome loss, and gross chromosomal rearrangements. Elg1 shows similarity to the large subunit of the Replication Factor C clamp loader, and forms a RFC-like (RLC) complex in conjunction with the 4 small RFC subunits. Two additional RLCs exist in yeast: in one of them the large subunit is Ctf18, and in the other, Rad24. Ctf18 has been characterized as the RLC that functions ...

  14. 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...

  15. 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...

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

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    2016-01-01

    reliability. Furthermore, a capacitor voltage control strategy by alternating two operation modes of the proposed modulation strategy is proposed to balance the voltage of the flying capacitor, which ensures multi-level voltages producing. Finally, the performance of the proposed converter and control......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...

  17. 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.

  18. 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.

  19. 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.

  20. A dnaN plasmid shuffle strain for rapid in vivo analysis of mutant Escherichia coli β clamps provides insight into the role of clamp in umuDC-mediated cold sensitivity.

    Directory of Open Access Journals (Sweden)

    Vignesh M P Babu

    Full Text Available The E. coli umuDC gene products participate in two temporally distinct roles: UmuD2C acts in a DNA damage checkpoint control, while UmuD'2C, also known as DNA polymerase V (Pol V, catalyzes replication past DNA lesions via a process termed translesion DNA synthesis. These different roles of the umuDC gene products are managed in part by the dnaN-encoded β sliding clamp protein. Co-overexpression of the β clamp and Pol V severely blocked E. coli growth at 30°C. We previously used a genetic assay that was independent of the ability of β clamp to support E. coli viability to isolate 8 mutant clamp proteins (βQ61K, βS107L, βD150N, βG157S, βV170M, βE202K, βM204K and βP363S that failed to block growth at 30°C when co-overexpressed with Pol V. It was unknown whether these mutant clamps were capable of supporting E. coli viability and normal umuDC functions in vivo. The goals of this study were to answer these questions. To this end, we developed a novel dnaN plasmid shuffle assay. Using this assay, βD150N and βP363S were unable to support E. coli viability. The remaining 6 mutant clamps, each of which supported viability, were indistinguishable from β+ with respect to umuDC functions in vivo. In light of these findings, we analyzed phenotypes of strains overexpressing either β clamp or Pol V alone. The strain overexpressing β+, but not those expressing mutant β clamps, displayed slowed growth irrespective of the incubation temperature. Moreover, growth of the Pol V-expressing strain was modestly slowed at 30°, but not 42°C. Taken together, these results suggest the mutant clamps were identified due to their inability to slow growth rather than an inability to interact with Pol V. They further suggest that cold sensitivity is due, at least in part, to the combination of their individual effects on growth at 30°C.

  1. A dnaN plasmid shuffle strain for rapid in vivo analysis of mutant Escherichia coli β clamps provides insight into the role of clamp in umuDC-mediated cold sensitivity.

    Science.gov (United States)

    Babu, Vignesh M P; Sutton, Mark D

    2014-01-01

    The E. coli umuDC gene products participate in two temporally distinct roles: UmuD2C acts in a DNA damage checkpoint control, while UmuD'2C, also known as DNA polymerase V (Pol V), catalyzes replication past DNA lesions via a process termed translesion DNA synthesis. These different roles of the umuDC gene products are managed in part by the dnaN-encoded β sliding clamp protein. Co-overexpression of the β clamp and Pol V severely blocked E. coli growth at 30°C. We previously used a genetic assay that was independent of the ability of β clamp to support E. coli viability to isolate 8 mutant clamp proteins (βQ61K, βS107L, βD150N, βG157S, βV170M, βE202K, βM204K and βP363S) that failed to block growth at 30°C when co-overexpressed with Pol V. It was unknown whether these mutant clamps were capable of supporting E. coli viability and normal umuDC functions in vivo. The goals of this study were to answer these questions. To this end, we developed a novel dnaN plasmid shuffle assay. Using this assay, βD150N and βP363S were unable to support E. coli viability. The remaining 6 mutant clamps, each of which supported viability, were indistinguishable from β+ with respect to umuDC functions in vivo. In light of these findings, we analyzed phenotypes of strains overexpressing either β clamp or Pol V alone. The strain overexpressing β+, but not those expressing mutant β clamps, displayed slowed growth irrespective of the incubation temperature. Moreover, growth of the Pol V-expressing strain was modestly slowed at 30°, but not 42°C. Taken together, these results suggest the mutant clamps were identified due to their inability to slow growth rather than an inability to interact with Pol V. They further suggest that cold sensitivity is due, at least in part, to the combination of their individual effects on growth at 30°C.

  2. 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...

  3. 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.

  4. 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.

  5. 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

  6. Robotic partial nephrectomy with cold ischemia and on-clamp tumor extraction: recapitulating the open approach.

    Science.gov (United States)

    Rogers, Craig G; Ghani, Khurshid R; Kumar, Ramesh K; Jeong, Wooju; Menon, Mani

    2013-03-01

    We describe a reproducible technique for achieving cold ischemia with intraoperative tumor assessment during robotic partial nephrectomy (RPN) that recapitulates the open approach: intracorporeal cooling and extraction (ICE). A total of seven patients underwent the ICE modification of RPN by transperitoneal (n=5) and retroperitoneal (n=2) approaches. A Gelpoint access port was used for the camera and assistant ports. Following hilar clamping, ice slush was introduced through the Gelpoint via syringes and applied over the kidney surface. The excised tumor was immediately extracted through the Gelpoint, allowing gross margin assessment by pathology during the renorrhaphy. RPN was achieved in all cases with successful introduction of ice slush and tumor extraction while on clamp. Median RENAL nephrometry score was 8 (range: 6-10), and there was one solitary kidney. Mean cold ischemia time was 19.6 min (range: 8-37) and mean estimated blood loss was 296.4 ml (range: 50-1000). Renal parenchymal temperatures 0.5°C during any procedures. Intraoperative assessment of the excised tumor showed adequate gross margins in all cases and final pathology confirmed negative surgical margins.

  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. 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)

  9. 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 inver......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...

  10. Artificial neural networks based controller for glucose monitoring during clamp test.

    Directory of Open Access Journals (Sweden)

    Merav Catalogna

    Full Text Available Insulin resistance (IR is one of the most widespread health problems in modern times. The gold standard for quantification of IR is the hyperinsulinemic-euglycemic glucose clamp technique. During the test, a regulated glucose infusion is delivered intravenously to maintain a constant blood glucose concentration. Current control algorithms for regulating this glucose infusion are based on feedback control. These models require frequent sampling of blood, and can only partly capture the complexity associated with regulation of glucose. Here we present an improved clamp control algorithm which is motivated by the stochastic nature of glucose kinetics, while using the minimal need in blood samples required for evaluation of IR. A glucose pump control algorithm, based on artificial neural networks model was developed. The system was trained with a data base collected from 62 rat model experiments, using a back-propagation Levenberg-Marquardt optimization. Genetic algorithm was used to optimize network topology and learning features. The predictive value of the proposed algorithm during the temporal period of interest was significantly improved relative to a feedback control applied at an equivalent low sampling interval. Robustness to noise analysis demonstrates the applicability of the algorithm in realistic situations.

  11. 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.

  12. The use of clamping grips and friction pads by tree frogs for climbing curved surfaces

    Science.gov (United States)

    Ji, Aihong; Yuan, Shanshan; Hill, Iain; Wang, Huan; Barnes, W. Jon P.; Dai, Zhendong; Sitti, Metin

    2017-01-01

    Most studies on the adhesive mechanisms of climbing animals have addressed attachment against flat surfaces, yet many animals can climb highly curved surfaces, like twigs and small branches. Here we investigated whether tree frogs use a clamping grip by recording the ground reaction forces on a cylindrical object with either a smooth or anti-adhesive, rough surface. Furthermore, we measured the contact area of fore and hindlimbs against differently sized transparent cylinders and the forces of individual pads and subarticular tubercles in restrained animals. Our study revealed that frogs use friction and normal forces of roughly a similar magnitude for holding on to cylindrical objects. When challenged with climbing a non-adhesive surface, the compressive forces between opposite legs nearly doubled, indicating a stronger clamping grip. In contrast to climbing flat surfaces, frogs increased the contact area on all limbs by engaging not just adhesive pads but also subarticular tubercles on curved surfaces. Our force measurements showed that tubercles can withstand larger shear stresses than pads. SEM images of tubercles revealed a similar structure to that of toe pads including the presence of nanopillars, though channels surrounding epithelial cells were less pronounced. The tubercles' smaller size, proximal location on the toes and shallow cells make them probably less prone to buckling and thus ideal for gripping curved surfaces. PMID:28228509

  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. Potential clamp of isolated dialyzed neuron: minimalization of the effect of series resistance.

    Science.gov (United States)

    Stolc, S; Nemcek, V; Boska, D

    1988-06-01

    A modification of the technique of intracellular dialysis of isolated single excitable cells, such as rat spinal ganglion neuron, suitable for potential clamping of its somatic membrane is described. The advantage of the new modification is the substantial reduction of the effect of inherent resistance in series (RS) to the membrane resistance (RM) on precision of potential clamping. This is attained by reversal of cell position in the perfusion pipette resulting in an approximately tenfold reduction in the area of active membrane. The resistance of this area proportionally increased while RS remained unchanged. Hence the error in potential fixation, which is inversely proportional to the ratio RM/RS, is by approximately one order smaller with the new technique than with the original one. An essential step in the new technique is the osmotic expansion of the cell to improve the contact of the cell with the perfusion pipette in the pore and to facilitate disruption of the appropriate part of the membrane. All features and advantages of the technique of intracellular dialysis, such as simplicity, the possibility to easily change ionic composition of media, and/or to apply drugs to any side of the membrane in the same cell, etc., have been maintained.

  15. Higher order modes excitation of electrostatically actuated clamped–clamped microbeams: experimental and analytical investigation

    KAUST Repository

    Jaber, Nizar

    2016-01-06

    © 2016 IOP Publishing Ltd. 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.

  16. Visually guided whole cell patch clamp of mouse supraoptic nucleus neurons in cultured and acute conditions.

    Science.gov (United States)

    Stachniak, Tevye J E; Bourque, Charles W

    2006-07-01

    Recent advances in neuronal culturing techniques have supplied a new set of tools for studying neural tissue, providing effective means to study molecular aspects of regulatory elements in the supraoptic nucleus of the hypothalamus (SON). To combine molecular biology techniques with electrophysiological recording, we modified an organotypic culture protocol to permit transfection and whole cell patch-clamp recordings from SON cells. Neonatal mouse brain coronal sections containing the SON were dissected out, placed on a filter insert in culture medium, and incubated for at least 4 days to allow attachment to the insert. The SON was identifiable using gross anatomical landmarks, which remained intact throughout the culturing period. Immunohistochemical staining identified both vasopressinergic and oxytocinergic cells present in the cultures, typically appearing in well-defined clusters. Whole cell recordings from these cultures demonstrated that certain properties of the neonatal mouse SON were comparable to adult mouse magnocellular neurons. SON neurons in both neonatal cultures and acute adult slices showed similar sustained outward rectification above -60 mV and action potential broadening during evoked activity. Membrane potential, input resistance, and rapidly inactivating potassium current density (IA) were reduced in the cultures, whereas whole cell capacitance and spontaneous synaptic excitation were increased, perhaps reflecting developmental changes in cell physiology that warrant further study. The use of the outlined organotypic culturing procedures will allow the study of such electrophysiological properties of mouse SON using whole cell patch-clamp, in addition to various molecular, techniques that require longer incubation times.

  17. 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.

  18. 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.

  19. 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.

  20. Ion channels as medicinal targets of biological toxins: the impact of automated patch-clamp electrophysiology.

    Science.gov (United States)

    Picones, Arturo

    2015-01-01

    Patch-Clamp electrophysiology, the "gold standard" for the functional study of ion channels has become automated. This innovative technology, already over a decade old, has revolutionized the strategies for the search of medicinal compounds which now can be screened at unprecedented speed, approaching the high throughput standards required by primary screening campaigns emblematic of the pharmaceutical and biotechnology industries. Consequently, an acceleration of the discovery and development of new drugs targeting ion channels is expected. These pore forming membrane proteins had been relegated as crucial therapeutic drug targets due to the difficulty of their experimental analysis. This new technological approach has begun to impact the finding of new toxins which are conspicuously relevant as medicinal agents given their extraordinary potency and specificity when acting upon ion channels. The introduction of automated patch-clamp instrumentation to academic labs and institutions pursuing the finding of new pharmacological agents, peptide toxins in particular, will certainly enrich these scientific and technological fields by contributing with their always prolific generosity of originality and innovation.

  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. 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.

  3. Does clamping during liver surgery predispose to thrombosis of the hepatic veins? Analysis of 210 cases

    Institute of Scientific and Technical Information of China (English)

    Nikolaos Arkadopoulos; Vaia Stafyla; Athanasios Marinis; Vassilios Koutoulidis; Kassiani Theodoraki; Theodosios Theodosopoulos; Ioannis Vassiliou; Nikolaos Dafnios; Georgios Fragulidis; Vassilios Smyrniotis

    2009-01-01

    AIM: To test whether clamping during liver surgery predisposes to hepatic vein thrombosis.METHODS: We performed a retrospective analysis of 210 patients who underwent liver resection with simultaneous inflow and outflow occlusion.Intraoperatively, flow in the hepatic veins was assessed by Doppler ultrasonography during the reperfusion phase. Postoperatively, patency of the hepatic veins was assessed by contrast-enhanced CT angiography,when necessary after 3-6 mo follow up.RESULTS: Twelve pat ients (5.7%) developed intraoperative liver remnant swelling. However,intraoperative ultrasonography did not reveal evidence of hepatic vein thrombosis. In three of these patients a kinking of the common trunk of the middle and left hepatic veins hindering outflow was recognized and was managed successfully by suturing the liver remnant to the diaphragm. Twenty three patients (10.9%) who developed signs of mild outflow obstruction postoperatively, had no evidence of thrombi in the hepatic veins or flow disturbances on ultrasonography and contrast-enhanced CT angiography, while hospitalized. Long term assessment of the patency of the hepatic veins over a 3-6 mo follow-up period did not reveal thrombi formation or clinical manifestations of outflow obstruction.CONCLUSION: Extrahepatic dissection and clamping of the hepatic veins does not predispose to clinically important thrombosis.

  4. 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.…

  5. Simultaneous paresthesia of the lingual nerve and inferior alveolar nerve caused by a radicular cyst.

    Science.gov (United States)

    Hamada, Yoshiki; Yamada, Hiroyuki; Hamada, Akiko; Kondoh, Toshirou; Suzuki, Mami; Noguchi, Kazuhide; Ito, Ko; Seto, Kanichi

    2005-10-01

    The inferior alveolar nerve is sometimes affected by periapical pathoses and mandibular cysts. However, mandibular intraosseous lesions have not been reported to disturb the lingual nerve. A case of simultaneous paresthesia of the right lingual nerve and the right inferior alveolar nerve is presented. The possible mechanisms of this extremely uncommon condition are discussed.

  6. 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.

  7. 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.

  8. 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.

  9. Predictions Shape Confidence in Right Inferior Frontal Gyrus.

    Science.gov (United States)

    Sherman, Maxine T; Seth, Anil K; Kanai, Ryota

    2016-10-05

    It is clear that prior expectations shape perceptual decision-making, yet their contribution to the construction of subjective decision confidence remains largely unexplored. We recorded fMRI data while participants made perceptual decisions and confidence judgments, manipulating perceptual prior expectations while controlling for potential confounds of attention. Results show that subjective confidence increases as expectations increasingly support the decision, and that this relationship is associated with BOLD activity in right inferior frontal gyrus (rIFG). Specifically, rIFG is sensitive to the discrepancy between expectation and decision (mismatch), and higher mismatch responses are associated with lower decision confidence. Connectivity analyses revealed expectancy information to be represented in bilateral orbitofrontal cortex and sensory signals to be represented in intracalcarine sulcus. Together, our results indicate that predictive information is integrated into subjective confidence in rIFG, and reveal an occipital-frontal network that constructs confidence from top-down and bottom-up signals. This interpretation was further supported by exploratory findings that the white matter density of right orbitofrontal cortex negatively predicted its respective contribution to the construction of confidence. Our findings advance our understanding of the neural basis of subjective perceptual processes by revealing an occipitofrontal functional network that integrates prior beliefs into the construction of confidence.

  10. Skeletal stability after inferior maxillary repositioning without interpositional graft.

    Science.gov (United States)

    Santos, S E; Moreira, R W F; de Moraes, M; Asprino, L; Araujo, M M

    2012-04-01

    True vertical maxillary deficiency is a characteristic of short face syndrome. In these patients, inferior repositioning of the maxilla (IRM) is indicated to improve facial aesthetics and function, but this procedure has been described as the most unstable. The aim of this study was to evaluate the long term, post surgical stability of IRM, fixed with four 2.0mm L-shaped miniplates, without any type of graft. A cephalometric study was performed, analysing linear measurements (anterior nasal spine, the A point, top of the incisor, top of the buccal-mesial cusp of the first molar, and posterior nasal spine on an X-Y coordinate system) traced immediately preoperatively, immediately postoperatively and at least 6 months post operatively. Eight young adult patients who underwent IRM were studied. The average results of this study were: surgical movement of 4.65 mm at I point, 5.32 mm at anterior nasal spine (ANS) point, and 4.70 mm at A point and relapses of 1.60 mm (35%), 2.23 mm (43%) and 2.10 mm (46%), respectively. It was concluded, that IRM using this type of internal rigid fixation without graft is unstable.

  11. Anterior Inferior Iliac Spine (AIIS) and Subspine Hip Impingement

    Science.gov (United States)

    Carton, Patrick; Filan, David

    2016-01-01

    Summary Background Abnormal morphology of the anterior inferior iliac spine (AIIS) and the subspine region of the acetabular rim are increasingly being recognised as a source of symptomatic extra-articular hip impingement. This review article aims to highlight important differences in the pathogenesis, clinical presentation and management of extra-articular hip impingement from both the AIIS and subspine bony regions, and the outcome following surgical intervention. Methods A literature review was undertaken to examine the supporting evidence for AIIS and subspine hip impingement. A narrative account of the Author’s professional experience in this area, including operative technique for arthroscopic correction, is also presented. Results Abnormal morphology of the AIIS and subspine region has been classified using cadaveric, radiological and arthroscopic means; the clinical presentation and operative treatment has been documented in several case series studies. Dual pathology is often present - recognition and treatment of both intra- and extra-articular components are necessary for good postoperative outcome. Conclusions AIIS and sub-spine hip impingement should be considered as distinct pathological entities, which may also co-exist. Symptom relief can be expected following arthroscopic deformity correction with the treatment of concomitant intra-articular pathology. Failure to recognise and treat the extra-articular component may affect postoperative outcome. Level of evidence V. PMID:28066737

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

    Directory of Open Access Journals (Sweden)

    Hong Men

    2011-09-01

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

  13. Opto-current-clamp actuation of cortical neurons using a strategically designed channelrhodopsin.

    Directory of Open Access Journals (Sweden)

    Lei Wen

    Full Text Available BACKGROUND: Optogenetic manipulation of a neuronal network enables one to reveal how high-order functions emerge in the central nervous system. One of the Chlamydomonas rhodopsins, channelrhodopsin-1 (ChR1, has several advantages over channelrhodopsin-2 (ChR2 in terms of the photocurrent kinetics. Improved temporal resolution would be expected by the optogenetics using the ChR1 variants with enhanced photocurrents. METHODOLOGY/PRINCIPAL FINDINGS: The photocurrent retardation of ChR1 was overcome by exchanging the sixth helix domain with its counterpart in ChR2 producing Channelrhodopsin-green receiver (ChRGR with further reform of the molecule. When the ChRGR photocurrent was measured from the expressing HEK293 cells under whole-cell patch clamp, it was preferentially activated by green light and has fast kinetics with minimal desensitization. With its kinetic advantages the use of ChRGR would enable one to inject a current into a neuron by the time course as predicted by the intensity of the shedding light (opto-current clamp. The ChRGR was also expressed in the motor cortical neurons of a mouse using Sindbis pseudovirion vectors. When an oscillatory LED light signal was applied sweeping through frequencies, it robustly evoked action potentials synchronized to the oscillatory light at 5-10 Hz in layer 5 pyramidal cells in the cortical slice. The ChRGR-expressing neurons were also driven in vivo with monitoring local field potentials (LFPs and the time-frequency energy distribution of the light-evoked response was investigated using wavelet analysis. The oscillatory light enhanced both the in-phase and out-phase responses of LFP at the preferential frequencies of 5-10 Hz. The spread of activity was evidenced by the fact that there were many c-Fos-immunoreactive neurons that were negative for ChRGR in a region of the motor cortex. CONCLUSIONS/SIGNIFICANCE: The opto-current-clamp study suggests that the depolarization of a small number of neurons

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-21

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

  16. Robust Clamping Force Control of an Electro-Mechanical Brake System for Application to Commercial City Buses

    Directory of Open Access Journals (Sweden)

    Sangjune Eum

    2017-02-01

    Full Text Available This paper proposes a sensor-less robust force control method for improving the control performance of an electro-mechanical brake (EMB which is applicable to commercial city buses. The EMB generates the accurate clamping force commanded by a driver through an independent motor control at each wheel instead of using existing mechanical components. In general, an EMB undergoes parameter variation and a backdrivability problem. For this reason, the cascade control strategy (e.g., force-position cascade control structure is proposed and the disturbance observer is employed to enhance control robustness against model variations. Additionally, this paper proposed the clamping force estimation method for a sensor-less control, i.e., the clamping force observer (CFO. Finally, in order to confirm the performance and effectiveness of a proposed robust control method, several experiments are performed and analyzed.

  17. 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.

  18. Firing clamp: A novel method for single-trial estimation of excitatory and inhibitory synaptic neuronal conductances

    Directory of Open Access Journals (Sweden)

    Anton eChizhov

    2014-03-01

    Full Text Available Understanding non-stationary neuronal activity as seen in vivo requires estimation of both excitatory and inhibitory synaptic conductances from a single trial of recording. We propose a new intracellular recording method for this purpose called firing clamp. Synaptic conductances are estimated from the characteristics of artificially evoked probe spikes, namely the spike amplitude and the mean subthreshold potential, which are sensitive to both excitatory and inhibitory synaptic input signals. The probe spikes, timed at a fixed rate, are evoked in the dynamic-clamp mode by injected meander-like current steps, with the step duration depending on neuronal membrane voltage. We test the method with perforated-patch recordings from isolated cells stimulated by external application or synaptic release of transmitter, and validate the method with simulations of a biophysically-detailed neuron model. The results are compared with the conductance estimates based on conventional current-clamp recordings.

  19. Surgical site wound infection in relation to antibiotic prophylaxis given before skin incision and after cord clamping during cesarean delivery.

    Science.gov (United States)

    Shrestha, B; Marhatha, R; Giri, A; Jaisi, S; Maskey, U

    2014-12-01

    Surgical site infection is one of the most common complications following Lower Segment Cesarean Section, which accounts for prolonged hospital stay thereby increasing expense. Prophylactic antibiotics in cesarean section reduces surgical site infection significantly. The best protection is provided when tissue level of antibiotics are adequate before incision, without prejudice to neonatal infectious morbidity. The objective of this study was to compare the incidence of surgical site wound infection with prophylactic antibiotics given before skin incision and after cord clamping following delivery of baby. This was a prospective, hospital based study, in which hundred cases of cesarean deliveries who received antibiotics prophylaxis one hour before the skin incision were compared with another 100 cases where antibiotic was given after cord clamping following delivery of the baby. Surgical site infection occurred in 3% of women who received antibiotics prophylaxis before skin incision as compared to 6% in whom antibiotic was given after cord clamping. It was statistically not significant (p = 0.465).

  20. 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.

  1. State-of-the-art automated patch clamp devices: Heat activation, action potentials and high throughput in ion channel screening

    Directory of Open Access Journals (Sweden)

    Sonja eStoelzle

    2011-11-01

    Full Text Available Ion channels are essential in a wide range of cellular functions and their malfunction underlies many disease states making them important targets in drug discovery. Diverse automated patch clamp systems with high-throughput capabilities are available for drug screening, but there are limitations in the application range. For example, solution exchange time, temperature control and the availability of the current clamp mode can be limiting factors. However, further development of existing devices and introduction of new systems widen the range of possible experiments and increase throughput. Here we introduce new features and platforms that meet the needs of drug discovery researchers and basic researchers alike.The Patchliner is an automated patch clamp system capable of recording up to 8 cells simultaneously with high success rates. Novel features such as temperature control and recordings in the current clamp mode are described here. Standard cell lines and excitable cells such as stem cell-derived cardiomyocytes have been used in the voltage clamp and current clamp modes with the view to finding new drug candidates and safety testing methods in a more physiologically relevant environment. The SyncroPatch 96, is a screening platform capable of recording from 96 cells in parallel and offers a throughput of 5000 data points per day. Full dose response curves can be acquired from individual cells reducing the cost per data point. The system is an ideal tool for secondary screening efforts and for safety testing on ligand- and voltage-gated ion channels.The Patchliner and SyncroPatch 96 are ideal platforms for drug discovery, ion channel research and safety testing, combining long awaited features such as parallel action potential recordings and temperature control with extensively increased throughput.

  2. ATP binding and hydrolysis-driven rate-determining events in the RFC-catalyzed PCNA clamp loading reaction.

    Science.gov (United States)

    Sakato, Miho; Zhou, Yayan; Hingorani, Manju M

    2012-02-17

    The multi-subunit replication factor C (RFC) complex loads circular proliferating cell nuclear antigen (PCNA) clamps onto DNA where they serve as mobile tethers for polymerases and coordinate the functions of many other DNA metabolic proteins. The clamp loading reaction is complex, involving multiple components (RFC, PCNA, DNA, and ATP) and events (minimally: PCNA opening/closing, DNA binding/release, and ATP binding/hydrolysis) that yield a topologically linked clamp·DNA product in less than a second. Here, we report pre-steady-state measurements of several steps in the reaction catalyzed by Saccharomyces cerevisiae RFC and present a comprehensive kinetic model based on global analysis of the data. Highlights of the reaction mechanism are that ATP binding to RFC initiates slow activation of the clamp loader, enabling it to open PCNA (at ~2 s(-1)) and bind primer-template DNA (ptDNA). Rapid binding of ptDNA leads to formation of the RFC·ATP·PCNA(open)·ptDNA complex, which catalyzes a burst of ATP hydrolysis. Another slow step in the reaction follows ATP hydrolysis and is associated with PCNA closure around ptDNA (8 s(-1)). Dissociation of PCNA·ptDNA from RFC leads to catalytic turnover. We propose that these early and late rate-determining events are intramolecular conformational changes in RFC and PCNA that control clamp opening and closure, and that ATP binding and hydrolysis switch RFC between conformations with high and low affinities, respectively, for open PCNA and ptDNA, and thus bookend the clamp loading reaction.

  3. 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.

  4. 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.

  5. 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 ...

  6. 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 (blood pressure to 51 +/- 3 mmHg, decreased urine output, and shifted NHE3 and NaPi2 out of the low......-density membranes enriched in apical markers. PTH at much lower doses (blood pressure and was diuretic. In conclusion, acute hypotension per se increases proximal tubule Na(+) reabsorption without changing NHE3 or NaPi2 subcellular distribution, indicating that trafficking...... 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...

  7. Global optimisation methods for poroelastic material characterisation using a clamped sample in a Kundt tube setup

    Science.gov (United States)

    Vanhuyse, Johan; Deckers, Elke; Jonckheere, Stijn; Pluymers, Bert; Desmet, Wim

    2016-02-01

    The Biot theory is commonly used for the simulation of the vibro-acoustic behaviour of poroelastic materials. However, it relies on a number of material parameters. These can be hard to characterize and require dedicated measurement setups, yielding a time-consuming and costly characterisation. This paper presents a characterisation method which is able to identify all material parameters using only an impedance tube. The method relies on the assumption that the sample is clamped within the tube, that the shear wave is excited and that the acoustic field is no longer one-dimensional. This paper numerically shows the potential of the developed method. It therefore performs a sensitivity analysis of the quantification parameters, i.e. reflection coefficients and relative pressures, and a parameter estimation using global optimisation methods. A 3-step procedure is developed and validated. It is shown that even in the presence of numerically simulated noise this procedure leads to a robust parameter estimation.

  8. Molecular force spectroscopy with a DNA origami-based nanoscopic force clamp.

    Science.gov (United States)

    Nickels, Philipp C; Wünsch, Bettina; Holzmeister, Phil; Bae, Wooli; Kneer, Luisa M; Grohmann, Dina; Tinnefeld, Philip; Liedl, Tim

    2016-10-21

    Forces in biological systems are typically investigated at the single-molecule level with atomic force microscopy or optical and magnetic tweezers, but these techniques suffer from limited data throughput and their requirement for a physical connection to the macroscopic world. We introduce a self-assembled nanoscopic force clamp built from DNA that operates autonomously and allows massive parallelization. Single-stranded DNA sections of an origami structure acted as entropic springs and exerted controlled tension in the low piconewton range on a molecular system, whose conformational transitions were monitored by single-molecule Förster resonance energy transfer. We used the conformer switching of a Holliday junction as a benchmark and studied the TATA-binding protein-induced bending of a DNA duplex under tension. The observed suppression of bending above 10 piconewtons provides further evidence of mechanosensitivity in gene regulation.

  9. 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.

  10. Endotoxemia-induced lymphocyte apoptosis is augmented by a hyperinsulinemic-euglycemic clamp

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Sylvest; A, Larsson; Brix-Christensen, Vibeke

    2005-01-01

    BACKGROUND: Sepsis and endotoxemia are associated with lymphocyte apoptosis. This has been regarded as harmful, contributing to further immune suppression in already immune-compromised patients. Because normalization of blood glucose improves outcome in critically ill patients, the authors...... hypothesized that one of the effects of insulin and normoglycemia would be inhibition of lymphocyte apoptosis. Therefore, in this experimental study in pigs, the authors examined the separate and combined effects of acute endotoxemia and a hyperinsulinemic-euglycemic clamp (HEC) on lymphocyte apoptosis...... sections of each sample, the apoptosis of B and T lymphocytes were analyzed using stereologic methods: The number of apoptotic B and T cells was estimated by fluorescence immunohistochemistry with anti-active caspase-3 and either anti-CD21 (B lymphocytes) or anti-CD3epsilon (T lymphocytes). The number...

  11. 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...

  12. An integrated, low noise patch-clamp amplifier for biological nanopore applications.

    Science.gov (United States)

    Wang, Gang; Dunbar, William B

    2010-01-01

    We present an integrated, low noise patch-clamp amplifier for biological nanopore applications. Our amplifier consists of an integrator-differentiator architecture coupled with a novel opamp design in the CMOS 0.35 µm process. The post-layout full-chip simulation shows the input referred noise of the amplifier is 0.49 pA RMS over a 5 kHz bandwidth using a verified electrical model for the biological nanopore system. In our biological nanopore experiments studying protein-DNA interactions, we encounter capacitive transients with a nominal settling time of 5 ms. Our amplifier design reduces the settling time to 0.2 ms, without requiring any compensation circuitry.

  13. 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.

  14. 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.

  15. 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.

  16. Simultaneous multi-patch-clamp and extracellular-array recordings: Single neuron reflects network activity

    Science.gov (United States)

    Vardi, Roni; Goldental, Amir; Sardi, Shira; Sheinin, Anton; Kanter, Ido

    2016-11-01

    The increasing number of recording electrodes enhances the capability of capturing the network’s cooperative activity, however, using too many monitors might alter the properties of the measured neural network and induce noise. Using a technique that merges simultaneous multi-patch-clamp and multi-electrode array recordings of neural networks in-vitro, we show that the membrane potential of a single neuron is a reliable and super-sensitive probe for monitoring such cooperative activities and their detailed rhythms. Specifically, the membrane potential and the spiking activity of a single neuron are either highly correlated or highly anti-correlated with the time-dependent macroscopic activity of the entire network. This surprising observation also sheds light on the cooperative origin of neuronal burst in cultured networks. Our findings present an alternative flexible approach to the technique based on a massive tiling of networks by large-scale arrays of electrodes to monitor their activity.

  17. 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.

  18. Macromechanical parametric amplification with a base-excited doubly clamped beam

    DEFF Research Database (Denmark)

    Neumeyer, Stefan; Thomsen, Jon Juel

    2013-01-01

    of steady-state vibration amplitude of the directly and parametrically excited system, to vibration amplitude of the directly excited only system. The nonlinear effect of midplane stretching is compared to the effects of nonlinear inertia and curvature. An approximate analytical expression for the vibration...... amplitude is derived. For a given small level of transverse displacement for both the cantilever and doubly clamped beam, the effect of midplane stretching is dominant compared to those caused by nonlinear inertia and curvature. It was found that the beam slenderness ratio can be used as an effective design......Parametric amplification is realized by adding parametric excitation to externally driven near-resonant oscillations. The effect of specific cubic nonlinearities on the parametrically amplified steady-state vibrations and gain is investigated theoretically. Here, gain is defined as the ratio...

  19. 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.

  20. 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%.

  1. 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.

  2. 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.

  3. 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

    NO (nitric oxide) may be involved in fluid homoeostasis. We hypothesized that increases in NO synthesis contribute to acute, saline-induced natriuresis, which, therefore, should be blunted when NO availability is stabilized. Young men were studied during simultaneous infusions of L-NAME [NG......-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...

  4. Screening system for drug-induced arrhythmogenic risk combining a patch clamp and heart simulator

    Science.gov (United States)

    Okada, Jun-ichi; Yoshinaga, Takashi; Kurokawa, Junko; Washio, Takumi; Furukawa, Tetsushi; Sawada, Kohei; Sugiura, Seiryo; Hisada, Toshiaki

    2015-01-01

    To save time and cost for drug discovery, a paradigm shift in cardiotoxicity testing is required. We introduce a novel screening system for drug-induced arrhythmogenic risk that combines in vitro pharmacological assays and a multiscale heart simulator. For 12 drugs reported to have varying cardiotoxicity risks, dose-inhibition curves were determined for six ion channels using automated patch clamp systems. By manipulating the channel models implemented in a heart simulator consisting of more than 20 million myocyte models, we simulated a standard electrocardiogram (ECG) under various doses of drugs. When the drug concentrations were increased from therapeutic levels, each drug induced a concentration-dependent characteristic type of ventricular arrhythmia, whereas no arrhythmias were observed at any dose with drugs known to be safe. We have shown that our system combining in vitro and in silico technologies can predict drug-induced arrhythmogenic risk reliably and efficiently. PMID:26601174

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

    DEFF Research Database (Denmark)

    Munch, Anders Sonne; Smith, Morten; Moldovan, Mihai

    2010-01-01

    The study of visually identified neurons in slice preparations from the central nervous system offers considerable advantages over in vivo preparations including high mechanical stability in the absence of anaesthesia and full control of the extracellular medium. However, because of their relative...... thinness, slices are not appropriate for investigating how individual neurons integrate synaptic inputs generated by large numbers of neurons. Here we took advantage of the exceptional resistance of the turtle to anoxia to make slices of increasing thicknesses (from 300 to 3000 microm) from the lumbar...... enlargement of the spinal cord. With a conventional upright microscope in which the light condenser was carefully adjusted, we could visualize neurons present at the surface of the slice and record them with the whole-cell patch clamp technique. We show that neurons present in the middle of the preparation...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-03

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

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

    Directory of Open Access Journals (Sweden)

    Nor Faezah Alias

    2013-12-01

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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...... that have been presented. The presented strategies are also comparatively evaluated to identify their individual advantages and disadvantages, which are subsequently summarized in a comprehensive reference table. Last, simulation and experimental results are included for validating the performances...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...... 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...... 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Evaluating LMA and CLAMP: Using information criteria to choose a model for estimating elevation

    Science.gov (United States)

    Miller, I.; Green, W.; Zaitchik, B.; Brandon, M.; Hickey, L.

    2005-12-01

    The morphology of leaves and composition of the flora respond strongly to the moisture and temperature of their environment. Elevation and latitude correlate, at first order, to these atmospheric parameters. An obvious modern example of this relationship between leaf morphology and environment is the tree line, where boreal forests give way to artic (high latitude) or alpine (high elevation) tundra. Several quantitative methods, all of which rely on uniformitarianism, have been developed to estimate paleoelevation using fossil leaf morphology. These include 1) the univariate leaf-margin analysis (LMA), which estimates mean annual temperature (MAT) by the positive linear correlation between MAT and P, the proportion of entire or smooth to non-entire or toothed margined woody dicot angiosperm leaves within a flora and 2) the Climate Leaf Analysis Multivariate Program (CLAMP) which uses Canonical Correspondence Analysis (CCA) to estimate MAT, moist enthalpy, and other atmospheric parameters using 31 explanatory leaf characters from woody dicot angiosperms. Given a difference in leaf-estimated MAT or moist enthalpy between contemporaneous, synlatitudinal fossil floras-one at sea-level, the other at an unknown paleoelevation-paleoelevation may be estimated. These methods have been widely applied to orogenic settings and concentrate particularly in the Western US. We introduce the use of information criteria to compare different models for estimating elevation and show how the additional complexity of the CLAMP analytical methodology does not necessarily improve on the elevation estimates produced by simpler regression models. In addition, we discuss the signal-to-noise ratio in the data, give confidence intervals for detecting elevations, and address the problem of spatial autocorrelation and irregular sampling in the data.

  15. 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.

  16. 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.

  17. 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.

  18. Tne stiffness of first-order and second-order modules assembled with extracortical clamp devices

    Directory of Open Access Journals (Sweden)

    F. K. Sabirov

    2015-01-01

    Full Text Available The extracortical clamp device (ECD is a tool used in external fixation which unlike the K-wires and half-pins don’t perforate cortical bone. The use of ECD is prospective for the treatment of periprosthetic femoral fractures and in the lengthening over nail and bone transport over nail. The data on the bench tests of the osteosynthesis rigidity by the external fixation first-order and second-order modules on the base of extracortical clamp devices are observed in the article. Materials and methods. The authors made 240 bench tests using torsional-vibration machine, Indicators measuring linear displacements with a scale of 0.01 mm, bone simulators («Sawbones», calibrated load, Ilizarov’s apparatus и extracortical fixators. The statistical analysis was performed with use software «STATISTICA» (ver. 6.0. The data obtained are presented in graphs «Box and Whisker Plot». Results. Among the investigated variants of first-order modules the better results of osteosynthesis rigidity were found in the module based on two ECD inserted at angle 60 degrees to each other and at distance of 10 cm from each other. Among the investigated second-order modules, better results of osteosynthesis rigidity were found in the module based on two ECD inserted at an angle 60 degrees to each other at distance of 10 cm from each other. Conclusion. Thus the tested modules can be used in practice in assemblies of external fixation devices in periprosthetic fractures, lengthening and bone transport over the nail.

  19. 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.

  20. [Massive inferior vena cava thrombosis in a patient with autosomal dominant polycystic hepatorenal disease].

    Science.gov (United States)

    Peces, R; Gil, F; Costero, O; Pobes, A

    2002-01-01

    We report a 68-year-old man with autosomal dominant polycystic kidney disease, who developed multiple venous thromboses (inferior vena cava, left renal vein and iliofemoral veins) caused by local compression of the intrahepatic inferior vena cava by hepatic cysts. To our knowledge this is the first reported case of inferior vena cava thrombosis caused by hepatic cysts compression. Doppler ultrasound, computed tomography, and magnetic resonance imaging were effective in documenting the venous thromboses and the underlying lesions non-invasively. Long-term anticoagulation was an efficient and safe treatment.

  1. [Anesthetic management of a patient with aortocaval fistula caused by rupture of a huge abdominal aortic aneurysm into the inferior vena cava].

    Science.gov (United States)

    Tanaka, Motonari; Kawashima, Akira; Kuremoto, Yoshito; Tanada, Kazuko

    2013-12-01

    Aortocaval fistula is a rare complication of ruptured abdominal aortic aneurysm. We report anesthetic management of a patient with aortocaval fistula caused by rupture of a huge abdominal aortic aneurysm into the inferior vena cava. A 51-year-old man who had complained of low back pain and general fatigue was referred to our hospital because of his liver damage. Aortocaval fistula due to rupture of a huge abdominal aortic aneurysm was diagnosed from physical examination, enhanced computed tomography and color Doppler ultrasonography. Anesthesia was induced with propofol and rocuronium, and was maintained with sevoflurane and remifentanil. After induction of anesthesia, the central venous pressure and cardiac index showed remarkably high values because of arteriovenous shunt. When the aneurysm was incised after the clamping of the abdominal aorta, massive venous bleeding occurred from the fistula and caused severe hypotension. Blood pressure recovered by digital compression of the bleeding point and the use of an autotransfusion device. After the repair of the aortocaval fistula, the hemodynamics became stable. The patient had a high output but a good cardiac function in preoperative examination. Therefore anesthesia was managed successfully without worsening high-output heart failure.

  2. Language outcomes after resection of dominant inferior parietal lobule gliomas.

    Science.gov (United States)

    Southwell, Derek G; Riva, Marco; Jordan, Kesshi; Caverzasi, Eduardo; Li, Jing; Perry, David W; Henry, Roland G; Berger, Mitchel S

    2017-01-06

    OBJECTIVE The dominant inferior parietal lobule (IPL) contains cortical and subcortical regions essential for language. Although resection of IPL tumors could result in language deficits, little is known about the likelihood of postoperative language morbidity or the risk factors predisposing to this outcome. METHODS The authors retrospectively examined a series of patients who underwent resections of gliomas from the dominant IPL. Postoperative language outcomes were characterized across the patient population. To identify factors associated with postoperative language morbidity, the authors then compared features between those patients who experienced postoperative deficits and those who experienced no postoperative language dysfunction. RESULTS Twenty-four patients were identified for analysis. Long-term language deficits occurred in 29.2% of patients (7 of 24): 3 of these patients had experienced preoperative language deficits, whereas new long-term language deficits occurred in 4 patients (16.7%; 4 of 24). Of those patients who exhibited preoperative language deficits, 62.5% (5 of 8) experienced long-term resolution of their language deficits with surgical treatment. All patients underwent intraoperative brain mapping by direct electrical stimulation. Awake, intraoperative cortical language mapping was performed on 17 patients (70.8%). Positive cortical language sites were identified in 23.5% of these patients (4 of 17). Awake, intraoperative subcortical language mapping was performed in 8 patients (33.3%). Positive subcortical language sites were identified in 62.5% of these patients (5 of 8). Patients with positive cortical language sites exhibited a higher rate of long-term language deficits (3 of 4, 75%), compared with those who did not (1 of 13, 7.7%; p = 0.02). Although patients with positive subcortical language sites exhibited a higher rate of long-term language deficits than those who exhibited only negative sites (40.0% vs 0.0%, respectively), this

  3. 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

  4. Tuberculosis pulmonar de campos inferiores Lower lung field tuberculosis

    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 Tuberculosis (TB that affects lower lung fields (LLFTB is infrequent in the adult population and is generally associated with immunodeficiency. The objective of our study was to determine the incidence of LLFTB in our patients population and compare the characteristics of these patients with those who presented TB of typical pulmonary localization. We studied 42 patients with LLFTB retrospectively between 2004 and 2008 and compared them to 84 patients with TB of typical localization (control group. HIV-positive patients were excluded. LLFTB represented 6% of the pulmonary TB cases. No significant differences were found with respect to age, sex, the presence of cavities in chest x-rays, days of evolution, and albumin levels. LLFTB had a significantly greater proportion of comorbilities (p < 0.001, the presence of condensation (p < 0.001, and unilateral involvement (p < 0.001, with a higher number of hospital admissions (p = 0.02. The observation that only 16 of the 42 patients with LLFTB (38% had a notable comorbility is important. Thus, LLFTB can be present without associated comorbilities and must be suspected in

  5. 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.

  6. Inferior mesenteric artery branch avulsion from blunt trauma--CT findings. Case report.

    Science.gov (United States)

    Olson, M; Posniak, H; Gomes, G

    1992-01-01

    Mesenteric arterial injuries are uncommon following blunt abdominal trauma. We describe the computed tomography (CT) findings of a patient with avulsion of a branch of the inferior mesenteric artery following a low-speed motor vehicle accident.

  7. Permanent neurologic deficit after inferior alveolar nerve block: a case report.

    Science.gov (United States)

    Shenkman, Z; Findler, M; Lossos, A; Barak, S; Katz, J

    1996-10-01

    Permanent neurologic damage after an inferior dental nerve block is reported. Clinical manifestations included hemisensory syndrome, facial nerve palsy, hearing impairment, and ataxia. Possible mechanisms and preventive measures are discussed.

  8. Anterior and posterior inferior cerebellar artery infarction with sudden deafness and vertigo.

    Science.gov (United States)

    Murakami, Takenobu; Nakayasu, Hiroyuki; Doi, Mitsuru; Fukada, Yasuyo; Hayashi, Miwa; Suzuki, Takeo; Takeuchi, Yuichi; Nakashima, Kenji

    2006-12-01

    We report a patient with anterior and posterior inferior cerebellar artery infarction, which manifested as profound deafness, transient vertigo, and minimal cerebellar signs. We suspect that ischaemia of the left internal auditory artery, which originates from the anterior inferior cerebellar artery, caused the deafness and transient vertigo. A small lesion in the middle cerebellar peduncle in the anterior inferior cerebellar artery territory and no lesion in the dentate nucleus in the posterior inferior cerebellar artery territory are thought to explain the minimal cerebellar signs despite the relatively large size of the infarction. Thus a relatively large infarction of the vertebral-basilar territory can manifest as sudden deafness with vertigo. Neuroimaging, including magnetic resonance imaging, is strongly recommended for patients with sudden deafness and vertigo to exclude infarction of the vertebral-basilar artery territory.

  9. 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.

  10. 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.

  11. 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.

  12. Measurement of the cell membrane capacitance and conductance of colonic crypt cells of the rat using the patch clamp technique

    CERN Document Server

    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. Accurately control and flatten gain spectrum of L-band erbium doped fiber amplifier based on suitable gain-clamping

    Science.gov (United States)

    Yang, Jiuru; Meng, Xiangyu; Liu, Chunyu

    2016-04-01

    The increasing traffic with dynamic nature requires the applications of gain-clamped L-band erbium-doped fiber amplifier (EDFA). However, the weak or over clamping may lead the unexpected gain-compression and flatness-worsening. In this article, to enhance practicality, we modify the partly gain-clamping configuration and utilize a pair of C-band fiber Bragg gratings (FBGs) to non-uniformly compress the gain spectrum of L-band. Through a comprehensive test and comparison, the suitable gain-clamping region for the amplified signals is found, and the gain in L-band is accurately controlled and flattened under the matched central wavelength of FBGs. The experimental results show that, our designed L-band EDFA achieves a trade-off among the output gain, flatness and stability. The ±0.44 dB flatness and 20.2 dB average gain are together obtained in the range of 1570-1610 nm, with the ±0.1 dB stability of signals in over 30 dBm dynamic range.

  14. 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....

  15. 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.

  16. 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 ...

  17. 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...

  18. 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...

  19. Inflammatory trigeminal nerve and tract lesions associated with inferior alveolar nerve anaesthesia.

    Science.gov (United States)

    Blair, N F; Parratt, J D E; Garsia, R; Brazier, D H; Cremer, P D

    2013-11-01

    Inferior alveolar nerve blocks are commonly performed for dental anaesthesia. The procedure is generally safe with a low rate of complications. We report a patient with a reproducible, delayed-onset sensory deficit associated with contrast-enhancing lesions in the trigeminal nerve, pons and medulla following inferior alveolar nerve local anaesthesia. We propose that this previously undescribed condition is a form of Type IV hypersensitivity reaction.

  20. Sample Size Estimation for Non-Inferiority Trials: Frequentist Approach versus Decision Theory Approach.

    Directory of Open Access Journals (Sweden)

    A C Bouman

    Full Text Available Non-inferiority trials are performed when the main therapeutic effect of the new therapy is expected to be not unacceptably worse than that of the standard therapy, and the new therapy is expected to have advantages over the standard therapy in costs or other (health consequences. These advantages however are not included in the classic frequentist approach of sample size calculation for non-inferiority trials. In contrast, the decision theory approach of sample size calculation does include these factors. The objective of this study is to compare the conceptual and practical aspects of the frequentist approach and decision theory approach of sample size calculation for non-inferiority trials, thereby demonstrating that the decision theory approach is more appropriate for sample size calculation of non-inferiority trials.The frequentist approach and decision theory approach of sample size calculation for non-inferiority trials are compared and applied to a case of a non-inferiority trial on individually tailored duration of elastic compression stocking therapy compared to two years elastic compression stocking therapy for the prevention of post thrombotic syndrome after deep vein thrombosis.The two approaches differ substantially in conceptual background, analytical approach, and input requirements. The sample size calculated according to the frequentist approach yielded 788 patients, using a power of 80% and a one-sided significance level of 5%. The decision theory approach indicated that the optimal sample size was 500 patients, with a net value of €92 million.This study demonstrates and explains the differences between the classic frequentist approach and the decision theory approach of sample size calculation for non-inferiority trials. We argue that the decision theory approach of sample size estimation is most suitable for sample size calculation of non-inferiority trials.

  1. Exposed inferior alveolar neurovascular bundle during surgical removal of a residual cyst.

    Science.gov (United States)

    Boffano, Paolo; Gallesio, Cesare

    2010-01-01

    Iatrogenic neurodeficiency is one of the most distressing complications to any surgical procedure. The prediction of close proximity of the oral lesions to the inferior alveolar neurovascular bundle is extremely important. Furthermore, iatrogenic neurosensory dysfunctions of the facial region involve important medicolegal issues. In this report, we describe the case of a patient who did not show either paresthesia or anesthesia after the surgical removal of a mandibular residual cyst that exhibited adherence to the inferior alveolar nerve bundle.

  2. Spontaneous alignment of crowded inferior incisives after the extractionof temporary canines

    OpenAIRE

    Orellana Manrique, Tomás Oriel; Departamento Académico de Estomatología Pediátrica. Facultad de Odontología UNMSM. Lima Perú.; Calderón Cortez, Iván; Estudiante de pre grado. Facultad de Odontología UNMSM. Lima Perú.; Orellana Manrique, Martín; Estudiante de Maestría. Facultad de Odontología UNMSM. Lima Perú.

    2014-01-01

    This investigation evaluated the behavior of permanent inferior incisives after the primary canine’s extractions. The study was carried out in the Pediatric Clinic of Dental Faculty of San Marcos University. The sample was conformed by 10 patients, male and female children, between 8 and 9 years of age, with good general health, having Class I malocclusion and severe crowding of the inferior incisives. It was taken Cephalometric and Panoramic radiographies, as well as models to make the ortho...

  3. [Investigation of the age-dependent development of brachygnathia inferior in the East Friesian milk sheep].

    Science.gov (United States)

    Pielmeier, Ricarda; Kerkmann, Andrea; Distl, Ottmar

    2012-01-01

    Shortness of the lower jaw (brachygnathia inferior, underbite) is a common anomaly in sheep. In order to study the age-dependent development of brachygnathia inferior, data of 73 East Friesian milk sheep from a breeding experiment over six generations were analysed. Data were recorded in regular intervals of four weeks from birth up to an age of at least 25 weeks. Brachygnathia inferior was determined by the distance between the edge of the central incisor of the lower jaw and the anterior surrounding of the upper jaw (DIFF-UK) using a measuring tape. Four main types of brachygnathia inferior were distinguished using means, standard deviations and maximum values of the individual animals.The thresholds were a maximum and mean DIFF-UK of 0.5 cm and a standard deviation of 0.266 cm. A total of 14 sheep (main types 3 and 4) showed an obvious brachygnathia inferior with mean DIFF-UK larger than 0.5 cm whereof ten animals showed a large variation of DIFF-UK values (standard deviation > 0.226 cm). Mean DIFF-UK values of 59 sheep were smaller than 0.5 cm (main types 1 and 2). One of these 59 animals had during the first four weeks of life DIFF-UK values of 1 cm and than decreasing values reaching zero within the next nine months (main type 2). Five of the 58 animals with main type 1 had a perfect occlusion of jaws, all with DIFF-UK values at zero during the whole recording period. Parents with severe or mild brachygnathia inferior had severely affected progeny. Selection of sheep for breeding with a perfect occlusion of jaws decreases the risk to pass on the hereditary disposition for brachygnathia inferior. An early inspection of potential breeding animals is advisable to detect all cases of brachygnathia inferior even if the underbite decreases in the first year of life.

  4. 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...

  5. 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)

  6. 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

  7. Proposal for the award of a contract, without competitive tendering, for the supply of chain clamps for the LHC beam vacuum system

    CERN Document Server

    2005-01-01

    This document concerns the award of a contract, without competitive tendering, for the supply of 810 chain clamps for the LHC beam vacuum system. The Finance Committee is invited to agree to the negotiation of a contract, without competitive tendering, with MKT (AT) for the supply of 810 chain clamps for a total amount of 480 000 Swiss francs, not subject to revision.

  8. Replication factor C is a more effective proliferating cell nuclear antigen (PCNA) opener than the checkpoint clamp loader, Rad24-RFC.

    Science.gov (United States)

    Thompson, Jennifer A; Marzahn, Melissa R; O'Donnell, Mike; Bloom, Linda B

    2012-01-13

    Clamp loaders from all domains of life load clamps onto DNA. The clamp tethers DNA polymerases to DNA to increase the processivity of synthesis as well as the efficiency of replication. Here, we investigated proliferating cell nuclear antigen (PCNA) binding and opening by the Saccharomyces cerevisiae clamp loader, replication factor C (RFC), and the DNA damage checkpoint clamp loader, Rad24-RFC, using two separate fluorescence intensity-based assays. Analysis of PCNA opening by RFC revealed a two-step reaction in which RFC binds PCNA before opening PCNA rather than capturing clamps that have transiently and spontaneously opened in solution. The affinity of RFC for PCNA is about an order of magnitude lower in the absence of ATP than in its presence. The affinity of Rad24-RFC for PCNA in the presence of ATP is about an order magnitude weaker than that of RFC for PCNA, similar to the RFC-PCNA interaction in the absence of ATP. Importantly, fewer open clamp loader-clamp complexes are formed when PCNA is bound by Rad24-RFC than when bound by RFC.

  9. Measuring the Pressure in the Superficial Inferior Epigastric Vein to Monitor for Venous Congestion in Deep Inferior Epigastric Artery Perforator Breast Reconstructions : A Pilot Study

    NARCIS (Netherlands)

    Smit, Jeroen M.; Audolfsson, Thorir; Whitaker, Iain S.; Werker, Paul M. N.; Acosta, Rafael; Liss, Anders G.

    2010-01-01

    During deep inferior epigastric artery perforator (DIEP) flap dissection, we noted that in many cases the superficial vein on the ipsilateral side of the flap was engorged and tense, and in others, it was empty. This led us to believe that the pressure is increased as the result of preferential outf

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Young's Modulus, Residual Stress, and Crystal Orientation of Doubly Clamped Silicon Nanowire Beams.

    Science.gov (United States)

    Calahorra, Y; Shtempluck, O; Kotchetkov, V; Yaish, Y E

    2015-05-13

    Initial or residual stress plays an important role in nanoelectronics. Valley degeneracy in silicon nanowires (SiNWs) is partially lifted due to built-in stresses, and consequently, electron-phonon scattering rate is reduced and device mobility and performance are improved. In this study we use a nonlinear model describing the force-deflection relationship to extract the Young's modulus, the residual stress, and the crystallographic growth orientation of SiNW beams. Measurements were performed on suspended doubly clamped SiNWs subjected to atomic force microscopy (AFM) three-point bending constraints. The nanowires comprised different growth directions and two SiO2 sheath thicknesses, and underwent different rapid thermal annealing processes. Analysis showed that rapid thermal annealing introduces compressive strains into the SiNWs and may result in buckling of the SiNWs. Furthermore, the core-shell model together with the residual stress analysis accurately describe the Young's modulus of oxide covered SiNWs and the crystal orientation of the measured nanowires.

  16. Peripheral nerve function during hyperglycemic clamping in insulin-dependent diabetic patients

    DEFF Research Database (Denmark)

    Sindrup, S H; Ejlertsen, B; Gjessing, H;

    1989-01-01

    glucose infusion. Hyperglycemia was accompanied by increased plasma osmolality. Sensory and motor nerve conduction and distal motor latency in the ulnar nerve were determined before, immediately after induction of hyperglycemia, and again after 120 min hyperglycemia. Distal (5th finger - wrist......) and proximal (wrist - elbow) sensory nerve conduction showed an insignificant increase as hyperglycemia was induced. During hyperglycemia mean distal sensory conduction decreased from 53.1 m/s to 50.4 m/s (P less than 0.05) and mean proximal sensory conduction decreased from 56.0 m/s to 54.2 m/s (P less than 0.......01). A mean of distal and proximal sensory conduction increased (53.5 m/s vs 54.6 m/s) (P less than 0.05) as hyperglycemia was induced and decreased (54.6 m/s vs 52.3 m/s) (P less than 0.01) during clamping. Motor nerve conduction decreased insignificantly throughout the study. Mean distal motor latency...

  17. A Novel, ;Double-Clamp; Binding Mode for Human Heme Oxygenase-1 Inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Mona N.; Vlahakis, Jason Z.; Vukomanovic, Dragic; Lee, Wallace; Szarek, Walter A.; Nakatsu, Kanji; Jia, Zongchao (Queens)

    2012-08-01

    The development of heme oxygenase (HO) inhibitors is critical in dissecting and understanding the HO system and for potential therapeutic applications. We have established a program to design and optimize HO inhibitors using structure-activity relationships in conjunction with X-ray crystallographic analyses. One of our previous complex crystal structures revealed a putative secondary hydrophobic binding pocket which could be exploited for a new design strategy by introducing a functional group that would fit into this potential site. To test this hypothesis and gain further insights into the structural basis of inhibitor binding, we have synthesized and characterized 1-(1H-imidazol-1-yl)-4,4-diphenyl-2-butanone (QC-308). Using a carbon monoxide (CO) formation assay on rat spleen microsomes, the compound was found to be {approx}15 times more potent (IC{sub 50} = 0.27{+-}0.07 {mu}M) than its monophenyl analogue, which is already a potent compound in its own right (QC-65; IC{sub 50} = 4.0{+-}1.8 {mu}M). The crystal structure of hHO-1 with QC-308 revealed that the second phenyl group in the western region of the compound is indeed accommodated by a definitive secondary proximal hydrophobic pocket. Thus, the two phenyl moieties are each stabilized by distinct hydrophobic pockets. This 'double-clamp' binding offers additional inhibitor stabilization and provides a new route for improvement of human heme oxygenase inhibitors.

  18. Intraoperative forces and moments analysis on patient head clamp during awake brain surgery.

    Science.gov (United States)

    De Lorenzo, Danilo; De Momi, Elena; Conti, Lorenzo; Votta, Emiliano; Riva, Marco; Fava, Enrica; Bello, Lorenzo; Ferrigno, Giancarlo

    2013-03-01

    In brain surgery procedures, such as deep brain stimulation, drug-resistant epilepsy and tumour surgery, the patient is intentionally awakened to map functional neural bases via electrophysiological assessment. This assessment can involve patient's body movements; thus, increasing the mechanical load on the head-restraint systems used for keeping the skull still during the surgery. The loads exchanged between the head and the restraining device can potentially result into skin and bone damage. The aim of this work is to assess such loads for laying down the requirements of a surgical robotics system for dynamic head movements compensation by fast moving arms and by an active restraint able to damp such actions. A Mayfield(®) head clamp was tracked and instrumented with strain gages (SGs). SG locations were chosen according to finite element analyses. During an actual brain surgery, displacements and strains were measured and clustered according to events that generated them. Loads were inferred from strain data. The greatest force components were exerted vertically (median 5.5 N, maximum 151.87 N) with frequencies up to 1.5 Hz. Maximum measured displacement and velocity were 9 mm and 60 mm/s, with frequencies up to 2.8 Hz. The analysis of loads and displacements allowed to identify the surgery steps causing maximal loads on the head-restraint device.

  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. The ELG1 clamp loader plays a role in sister chromatid cohesion.

    Directory of Open Access Journals (Sweden)

    Oren Parnas

    Full Text Available Mutations in the ELG1 gene of yeast lead to genomic instability, manifested in high levels of genetic recombination, chromosome loss, and gross chromosomal rearrangements. Elg1 shows similarity to the large subunit of the Replication Factor C clamp loader, and forms a RFC-like (RLC complex in conjunction with the 4 small RFC subunits. Two additional RLCs exist in yeast: in one of them the large subunit is Ctf18, and in the other, Rad24. Ctf18 has been characterized as the RLC that functions in sister chromatid cohesion. Here we present evidence that the Elg1 RLC (but not Rad24 also plays an important role in this process. A genetic screen identified the cohesin subunit Mcd1/Scc1 and its loader Scc2 as suppressors of the synthetic lethality between elg1 and ctf4. We describe genetic interactions between ELG1 and genes encoding cohesin subunits and their accessory proteins. We also show that defects in Elg1 lead to higher precocious sister chromatid separation, and that Ctf18 and Elg1 affect cohesion via a joint pathway. Finally, we localize both Ctf18 and Elg1 to chromatin and show that Elg1 plays a role in the recruitment of Ctf18. Our results suggest that Elg1, Ctf4, and Ctf18 may coordinate the relative movement of the replication fork with respect to the cohesin ring.

  1. Elg1, an alternative subunit of the RFC clamp loader, preferentially interacts with SUMOylated PCNA.

    Science.gov (United States)

    Parnas, Oren; Zipin-Roitman, Adi; Pfander, Boris; Liefshitz, Batia; Mazor, Yuval; Ben-Aroya, Shay; Jentsch, Stefan; Kupiec, Martin

    2010-08-04

    Replication-factor C (RFC) is a protein complex that loads the processivity clamp PCNA onto DNA. Elg1 is a conserved protein with homology to the largest subunit of RFC, but its function remained enigmatic. Here, we show that yeast Elg1 interacts physically and genetically with PCNA, in a manner that depends on PCNA modification, and exhibits preferential affinity for SUMOylated PCNA. This interaction is mediated by three small ubiquitin-like modifier (SUMO)-interacting motifs and a PCNA-interacting protein box close to the N-terminus of Elg1. These motifs are important for the ability of Elg1 to maintain genomic stability. SUMOylated PCNA is known to recruit the helicase Srs2, and in the absence of Elg1, Srs2 and SUMOylated PCNA accumulate on chromatin. Strains carrying mutations in both ELG1 and SRS2 exhibit a synthetic fitness defect that depends on PCNA modification. Our results underscore the importance of Elg1, Srs2 and SUMOylated PCNA in the maintenance of genomic stability.

  2. Eigensensitivity analysis of rotating clamped uniform beams with the asymptotic numerical method

    Science.gov (United States)

    Bekhoucha, F.; Rechak, S.; Cadou, J. M.

    2016-12-01

    In this paper, free vibrations of a rotating clamped Euler-Bernoulli beams with uniform cross section are studied using continuation method, namely asymptotic numerical method. The governing equations of motion are derived using Lagrange's method. The kinetic and strain energy expression are derived from Rayleigh-Ritz method using a set of hybrid variables and based on a linear deflection assumption. The derived equations are transformed in two eigenvalue problems, where the first is a linear gyroscopic eigenvalue problem and presents the coupled lagging and stretch motions through gyroscopic terms. While the second is standard eigenvalue problem and corresponds to the flapping motion. Those two eigenvalue problems are transformed into two functionals treated by continuation method, the Asymptotic Numerical Method. New method proposed for the solution of the linear gyroscopic system based on an augmented system, which transforms the original problem to a standard form with real symmetric matrices. By using some techniques to resolve these singular problems by the continuation method, evolution curves of the natural frequencies against dimensionless angular velocity are determined. At high angular velocity, some singular points, due to the linear elastic assumption, are computed. Numerical tests of convergence are conducted and the obtained results are compared to the exact values. Results obtained by continuation are compared to those computed with discrete eigenvalue problem.

  3. 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.

  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. 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).

  6. 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.

  7. 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.

  8. 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.

  9. Thermography for the clinical assessment of inferior alveolar nerve deficit: a pilot study.

    Science.gov (United States)

    Gratt, B M; Sickles, E A; Shetty, V

    1994-01-01

    Neurosensory deficit is a major complication encountered in maxillofacial surgery. This study assessed the ability of electronic thermography to identify inferior alveolar nerve deficits in a pilot clinical study. The study population comprised six patients with inferior alveolar nerve deficit and 12 normal subjects. Frontally projected facial thermograms were taken on 18 subjects and measured using an Agema 870 unit and thermal image computer. Mathematical analysis of thermal measurements included temperature and delta T calculations of the anatomic zone over the mental region of the face. Results included (1) high levels of thermal symmetry of the chin in normal subjects (delta T = 0.1 degree C, standard deviation = 0.1 degree C); (2) low levels of thermal symmetry in patients with inferior alveolar nerve deficits (delta T = +0.5 degree C, standard deviation = 0.2 degree C); (3) statistically significant differences in delta T values (t = 4.82, P > .001) in patients with inferior alveolar nerve deficit; and (4) absolute temperature variations of the mental region in both groups. This pilot study demonstrated thermal asymmetry in patients with inferior alveolar nerve deficit and suggests that electronic thermography has promise as a simple, objective, noninvasive method for evaluating nerve deficits. However, more extensive studies are needed before thermographic procedures are accepted clinically.

  10. 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.

  11. 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.

  12. 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.

  13. Restoration of diaphragmatic function after diaphragm reinnervation by inferior laryngeal nerve; experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    de Barros Angelique

    2006-01-01

    Full Text Available Abstract Objectives To assess the possibilities of reinnervation in a paralyzed hemidiaphragm via an anastomosis between phrenic nerve and inferior laryngeal nerve in rabbits. Reinnervation of a paralyzed diaphragm could be an alternative to treat patients with ventilatory insufficiency due to upper cervical spine injuries. Material and method Rabbits were divided into five groups of seven rabbits each. Groups I and II were respectively the healthy and the denervated control groups. The 3 other groups were all reinnervated using three different surgical procedures. In groups III and IV, phrenic nerve was respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the trunk of the inferior laryngeal nerve. In group V, the fifth and fourth cervical roots were respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the nerve of the sternothyroid muscle (originating from the hypoglossal nerve. Animals were evaluated 4 months later using electromyography, transdiaphragmatic pressure measurements, sonomicrometry and histological examination. Results A poor inspiratory activity was found in quiet breathing in the reinnervated groups, with an increasing pattern of activity during effort. In the reinnervated groups, transdiaphragmatic pressure measurements and sonomicrometry were higher in group III with no significant differencewith groups IV and V. Conclusion Inspiratory contractility of an hemidiaphragm could be restored with immediate anastomosis after phrenic nerve section between phrenic nerve and inferior laryngeal nerve.

  14. Dual joint space arthrography in temporomandibular joint disorders: Comparison with single inferior joint space arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyung Sik; Chang, Duk Soo; Lee, Kyung Soo; Kim, Woo Sun; Sung, Jung Ho; Jun, Young Hwan [Capital Armed Forces General Hospital, Seoul (Korea, Republic of)

    1989-02-15

    The temporomandibular joint(TMJ) is really a complex of two synovial space separated by fibrocartilaginous disc. Single inferior joint space arthrography is commonly performed for evaluation of TMJ disorders, which is known to be superior in demonstrating joint dynamics. But it reveals only the inferior surface of the disc. Therefore, dual space arthrography is superior to demonstrate the soft tissue anatomic feature of the joint such as disc position and shape. Authors performed 83 TMJ arthrograms in TMJ problems. Initially, the inferior joint space was done and then the superior space was sequentially contrasted. The follow results were noted: 1. In all cases, dual space arthrography revealed accurate disc shape and positions. 2. Concordant findings between the two techniques: 68 cases (82%). Discordance between the two techniques: 15 cases (18%) 3. Possible causes of discordance between inferior and dual space arthrography. a) Normal varians of anterior recess: 3 cases b) Posterior disc displacement: 4 cases c) Influence of the patient's head position change :4 cases d) False perforation: 2 cases e) Reduction change: 2 cases 4. In 5 cases with anterior displacement, dual space arthrography gave additional findings such as adhesion within the superior space, which could not be evaluated by single inferior space.

  15. [MASSIVE HEMORRHAGE FROM THE FISTULA FORMATION BETWEEN CUTANEOUS URETEROSTOMY AND INFERIOR EPIGASTRIC ARTERY: A CASE REPORT].

    Science.gov (United States)

    Fujinami, Hiroyuki; Shibuya, Tadamasa; Mori, Kenichi; Shin, Toshitaka; Sumino, Yasuhiro; Sato, Fuminori; Mimata, Hiromitsu; Sato, Yoshiyasu; Matsubara, Takanori; Sakamoto, Sadaaki; Kamei, Noritaka; Hongo, Tetsuo

    2015-04-01

    A 87-year-old man received radical nephroureterectomy for right renal pelvic cancer in 2009 and left cutaneous ureterostomy after radical cystectomy for bladder cancer in 2013. He visited the hospital for exchanging a 7 or 8 Fr single-J catheter every 2 to 4 weeks. Eleven months after the 2nd operation, massive bleeding from the stoma occurred when ureteral catheter was exchanged. Contrast-enhanced computed tomography showed that left inferior epigastric artery was located close to left ureter. Angiography of the left inferior epigastric artery didn't show an obvious fistula, but revealed the stoma was surrounded by ramified new blood vessels from left inferior epigastric artery. We suspected a rupture of the vessels and performed embolization for the branch of inferior epigastric artery to left ureter. This embolization made it possible for the bleeding to be controlled. Massive bleeding from the branch of inferior epigastric artery is very rare, and we report the case and review the literature.

  16. On the Experimental Investigation of the Clamping Pressure Effects on the Proton Exchange Membrane Water Electrolyser Cell Performance

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Frensch, Steffen Henrik; Kær, Søren Knudsen

    2017-01-01

    to migrate to negatively chargedcathode, where hydrogen is reduced. Meanwhile, oxygen is produced at the anode sideelectrode and escape as a gas with the circulating water.In the recent few years, PEMWE’s R&D has inched towards; operating conditions; such asincreased operating temperature and cathode...... at different clamping pressures. All thesemeasurements are conducted at constant cell temperature (70°C) and atmospheric pressure.Furthermore, to ensure a high confidence level in the obtained data, experiments are repeatedfew times.Early results for polarization curve predict that the PEMWE cell performance...... increases withincreasing the clamping pressure at fixed temperature and current density. This can beelucidated by the EIS measurements which predict an increment in ohmic and activation...

  17. Improved non-dimensional dynamic influence function method for vibration analysis of arbitrarily shaped plates with clamped edges

    Directory of Open Access Journals (Sweden)

    Sang-Wook Kang

    2016-03-01

    Full Text Available A new formulation for the non-dimensional dynamic influence function method, which was developed by the authors, is proposed to efficiently extract eigenvalues and mode shapes of clamped plates with arbitrary shapes. Compared with the finite element and boundary element methods, the non-dimensional dynamic influence function method yields highly accurate solutions in eigenvalue analysis problems of plates and membranes including acoustic cavities. However, the non-dimensional dynamic influence function method requires the uneconomic procedure of calculating the singularity of a system matrix in the frequency range of interest for extracting eigenvalues because it produces a non-algebraic eigenvalue problem. This article describes a new approach that reduces the problem of free vibrations of clamped plates to an algebraic eigenvalue problem, the solution of which is straightforward. The validity and efficiency of the proposed method are illustrated through several numerical examples.

  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. 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.

  1. PWM Regulation of Grid-Tied PV System on the Base of Photovoltaic-Fed Diode-Clamped Inverters

    Directory of Open Access Journals (Sweden)

    Oleschuk V.I.

    2015-12-01

    Full Text Available Investigation of grid-tied photovoltaic system on the base of two diode-clamped inverters, controlled by specific algorithms of pulse-width modulation (PWM, has been done. This system includes two strings of photovoltaic panels feeding two diode-clamped inverters. The outputs of inverters are connected with the corresponding windings on the primary side of three-phase transformer, connected with a grid. In order to reduce phase voltage distortion and to increase efficiency of operation of the system, special scheme of control and modulation of inverters has been used, providing minimization of common-mode voltages and voltage waveforms symmetries under different operating conditions. Detailed simulation of processes in this photovoltaic-fed power conversion system has been executed. The results of simulations verify good performance of photovoltaic system regulated in accordance with specific strategy of control and modulation.

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

    DEFF Research Database (Denmark)

    Nami, Alireza; Zare, Firuz; Ghosh, Arindam

    2011-01-01

    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......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...

  3. The use of a bulldog clamp to control the dorsal vein complex during robot-assisted radical prostatectomy.

    Science.gov (United States)

    Tüfek, Ilter; Atuğ, Fatih; Argun, Burak; Keskin, Selçuk; Obek, Can; Coşkuner, Enis; Kural, Ali Riza

    2012-12-01

    Optimal control of the dorsal venous complex (DVC) is a critical step in robot-assisted radical prostatectomy (RARP). If DVC is not controlled properly, bleeding may occur during the apical dissection. On the other hand, if it is controlled well, a bloodless field is attained and, thus, a precise apical dissection and urethral division is possible. Suture ligation is the most common technique used for dorsal vein control, while some authors recommend using an endovascular stapler. Recently, athermal division and selective suture ligation technique has been reported for DVC control. We describe a new technique: Use of a bulldog clamp to control the DVC during RARP. The control of the DVC with a bulldog clamp allows a bloodless field with precise apical dissection and provides preservation of maximum urethral length while avoiding sphincteral injury.

  4. 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.

  5. 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.

  6. In vitro Imaging neokortikaler Pyramidenneuronen nach patch-clamp gestützter Beladung mit Quantum Dots

    OpenAIRE

    Bullinger, Ruben

    2013-01-01

    In dieser Arbeit wurden mit einer neueren Klasse von Fluoreszenzfarbstoffen, den sogenannten „Quantum Dots“, neokortikale Pyramidenneurone in vitro angefärbt. Als Markierungsmethoden wurden Mikroinjektion, unter Anwendung der Patch clamp-Technik und Elektroporation optimiert. Zielsetzungen waren die Darstellung einzelner Pyramidenneurone bis hin zu ganzen Zellverbänden des Kortex. Es konnte gezeigt werden, dass Mikroinjektion und Elektroporation zuverlässige Methoden sind, um einzelne Pyramid...

  7. Vascular relaxation of canine visceral arteries after ischemia by means of supraceliac aortic cross-clamping followed by reperfusion

    OpenAIRE

    Dalio Marcelo B; Evora Paulo RB; Joviliano Edwaldo E; Baldo Caroline F; Celotto Andrea C; Capellini Verena K; Ciscato José G; Piccinato Carlos E

    2010-01-01

    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 dysfunctio...

  8. 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.

  9. Incidence and Progression of Cardiac Surgery-associated Acute Kidney Injury and its Relationship with Bypass and Cross Clamp Time

    Science.gov (United States)

    Karim, Habib Md Reazaul; Yunus, Mohd; Saikia, Manuj Kumar; Kalita, Jyoti Prasad; Mandal, Mrinal

    2017-01-01

    Introduction: Cardiac surgery-associated kidney injury (CSA-AKI) is common but relatively less is known about its progression. The present study is aimed at evaluating the incidence and course of CSA-AKI and its relationship with the different durations of cardiopulmonary bypass (CPB) and cross clamp times. Materials and Methods: Occurrences of CSA-AKI are evaluated as per the Akin Kidney Injury Network (AKIN) criteria over the course of 5 postoperative day (POD) in 100 patients. The relationship of different durations of CPB and aortic cross clamp time with CSA-AKI is analyzed by Chi-squared test for trend and other appropriate tests using INSTAT software. Results: One hundred (43 male, 57 female; mean age of 37.01 ± 12.28 years, and baseline mean serum creatinine 0.99 ± 0.20 mg %) patients undergone mostly valve replacement, and congenital heart disease correction was evaluated. Nearly 49% suffered CSA-AKI (81.63% AKIN Class I) with maximum numbers on 2nd POD. Serum creatinine followed a falling trend 3rd POD onward except in 8.16% cases of CSA-AKI. Oliguria was absent even in AKIN Class II. The CPB time >70 min and cross clamp time >60 min increase CSA-AKI risk by an OR of 4.76 and 2.84, respectively (P < 0.05). Conclusion: CSA-AKI is very prevalent; mostly of AKIN Class I and increases with increasing CPB and cross clamp time. Urine output is not a reliable indicator of CSA-AKI. The AKIN Class II on the very 1st POD or increasing trend of serum creatinine beyond 3rd POD should alert for early intervention. PMID:28074790

  10. 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.

  11. Dynamics of T-Junction Solution Switching Aimed at Patch Clamp Experiments

    Science.gov (United States)

    Auzmendi, Jerónimo A.; Smoler, Mariano; Moffatt, Luciano

    2015-01-01

    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. PMID:26177538

  12. 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.

  13. Safety of over twelve hundred infant male circumcisions using the Mogen clamp in Kenya.

    Directory of Open Access Journals (Sweden)

    Marisa R Young

    Full Text Available BACKGROUND: Several sub-Saharan African countries plan to scale-up infant male circumcision (IMC for cost-efficient HIV prevention. Little data exist about the safety of IMC in East and southern Africa. We calculated adverse event (AE rate and risks for AEs associated with introduction of IMC services at five government health facilities in western Kenya. METHODS: AE data were analyzed for IMC procedures performed between September, 2009 and November, 2011. Healthy infants aged ≤ 2 months and weighing ≥ 2.5 kg were eligible for IMC. Following parental consent, trained clinicians provided IMC services free of charge under local anesthesia using the Mogen clamp. Odds ratios and 95% confidence intervals were used to explore AE risk factors. FINDINGS: A total of 1,239 IMC procedures were performed. Median age of infants was 4 days (IQR=1, 16. The overall AE rate among infants reviewed post-operatively was 2.7% (18/678; 95%CI: 1.4, 3.9. There was one severe AE involving excision of a small piece of the lateral aspect of the glans penis. Other AEs were mild or moderate and were treated conservatively. Babies one month of age or older were more likely to have an AE (OR 3.20; 95%CI: 1.23, 8.36. AE rate did not differ by nurse versus clinical officer or number of previous procedures performed. CONCLUSION: IMC services provided in Kenyan Government hospitals in the context of routine IMC programming have AE rates comparable to those in developed countries. The optimal time for IMC is within the first month of life.

  14. Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography

    Science.gov (United States)

    Brueggemann, Lioubov I.; Mani, Bharath K.; Haick, Jennifer; Byron, Kenneth L.

    2012-01-01

    Contraction or relaxation of smooth muscle cells within the walls of resistance arteries determines the artery diameter and thereby controls flow of blood through the vessel and contributes to systemic blood pressure. The contraction process is regulated primarily by cytosolic calcium concentration ([Ca2+]cyt), which is in turn controlled by a variety of ion transporters and channels. Ion channels are common intermediates in signal transduction pathways activated by vasoactive hormones to effect vasoconstriction or vasodilation. And ion channels are often targeted by therapeutic agents either intentionally (e.g. calcium channel blockers used to induce vasodilation and lower blood pressure) or unintentionally (e.g. to induce unwanted cardiovascular side effects). Kv7 (KCNQ) voltage-activated potassium channels have recently been implicated as important physiological and therapeutic targets for regulation of smooth muscle contraction. To elucidate the specific roles of Kv7 channels in both physiological signal transduction and in the actions of therapeutic agents, we need to study how their activity is modulated at the cellular level as well as evaluate their contribution in the context of the intact artery. The rat mesenteric arteries provide a useful model system. The arteries can be easily dissected, cleaned of connective tissue, and used to prepare isolated arterial myocytes for patch clamp electrophysiology, or cannulated and pressurized for measurements of vasoconstrictor/vasodilator responses under relatively physiological conditions. Here we describe the methods used for both types of measurements and provide some examples of how the experimental design can be integrated to provide a clearer understanding of the roles of these ion channels in the regulation of vascular tone. PMID:23007713

  15. Whole-cell clamp of dissociated photoreceptors from the eye of Lima scabra.

    Science.gov (United States)

    Nasi, E

    1991-01-01

    Voltage-dependent membrane currents were investigated in enzymatically dissociated photoreceptors of Lima scabra using the whole-cell clamp technique. Depolarizing steps to voltages more positive than -10 mV elicit a transient inward current followed by a delayed, sustained outward current. The outward current is insensitive to replacement of a large fraction of extracellular Cl- with the impermeant anion glucuronate. Superfusion with tetraethylammonium and 4-aminopyridine reversibly abolishes the outward current, and internal perfusion with cesium also suppresses it, indicating that it is mediated by potassium channels. Isolation of the inward current reveals a fast activation kinetics, the peak amplitude occurring as early as 4-5 ms after stimulus onset, and a relatively rapid, though incomplete inactivation. Within the range of voltages examined, spanning up to +90 mV, reversal was not observed. The inward current is not sensitive to tetrodotoxin at concentrations up to 10 microM, and survives replacement of extracellular Na with tetramethylammonium. On the other hand, it is completely eliminated by calcium removal from the perfusing solution, and it is partially blocked by submillimolar concentrations of cadmium, suggesting that it is entirely due to voltage-dependent calcium channels. Analysis of the kinetics and voltage dependence of the isolated calcium current indicates the presence of two components, possibly reflecting the existence of separate populations of channels. Barium and strontium can pass through these channels, though less easily than calcium. Both the activation and the inactivation become significantly more sluggish when these ions serve as the charge carrier. A large fraction of the outward current is activated by preceding calcium influx. Suppression of this calcium-dependent potassium current shows a small residual component resembling the delayed rectifier. In addition, a transient outward current sensitive to 4-aminopyridine (Ia) could

  16. 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.

  17. Expanding neurochemical investigations with multi-modal recording: simultaneous fast-scan cyclic voltammetry, iontophoresis, and patch clamp measurements.

    Science.gov (United States)

    Kirkpatrick, D C; McKinney, C J; Manis, P B; Wightman, R M

    2016-08-02

    Multi-modal recording describes the simultaneous collection of information across distinct domains. Compared to isolated measurements, such studies can more easily determine relationships between varieties of phenomena. This is useful for neurochemical investigations which examine cellular activity in response to changes in the local chemical environment. In this study, we demonstrate a method to perform simultaneous patch clamp measurements with fast-scan cyclic voltammetry (FSCV) using optically isolated instrumentation. A model circuit simulating concurrent measurements was used to predict the electrical interference between instruments. No significant impact was anticipated between methods, and predictions were largely confirmed experimentally. One exception was due to capacitive coupling of the FSCV potential waveform into the patch clamp amplifier. However, capacitive transients measured in whole-cell current clamp recordings were well below the level of biological signals, which allowed the activity of cells to be easily determined. Next, the activity of medium spiny neurons (MSNs) was examined in the presence of an FSCV electrode to determine how the exogenous potential impacted nearby cells. The activities of both resting and active MSNs were unaffected by the FSCV waveform. Additionally, application of an iontophoretic current, used to locally deliver drugs and other neurochemicals, did not affect neighboring cells. Finally, MSN activity was monitored during iontophoretic delivery of glutamate, an excitatory neurotransmitter. Membrane depolarization and cell firing were observed concurrently with chemical changes around the cell resulting from delivery. In all, we show how combined electrophysiological and electrochemical measurements can relate information between domains and increase the power of neurochemical investigations.

  18. 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.

  19. 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

  20. Percutaneous clamping of spiral and oblique fractures of the tibial shaft: a safe and effective reduction aid during intramedullary nailing.

    Science.gov (United States)

    Collinge, Cory A; Beltran, Michael J; Dollahite, Henry A; Huber, Florian G

    2015-06-01

    The reduction of tibial shaft fractures during intramedullary nailing is important if limb alignment is to be restored and successful clinical outcomes are expected. We have used a percutaneously applied (or open) clamp or clamps to achieve and maintain reduction during nailing of all amendable tibial shaft fractures. In this article, we describe the technique and preliminary results comparing closed, simple spiral and oblique tibial shaft fractures (OTA 42-A1 and A2) managed with percutaneous clamp-assisted nailing (CAN) versus nailing using manual reduction (MRN) held by the surgical team. In the MRN group, there were an increased fracture gap (P = 0.04) and trends toward malalignment (P = 0.07) and healing time (P = 0.06) compared with the CAN group. There were also trends in clinical; no wound complications occurred in either group. We have found that percutaneous CAN of closed, simple spiral and oblique tibial shaft fractures seems safe and allows for early predictable union with reproducible alignment compared with nailing using MRN.

  1. Analysis of the dynamic avalanche of carrier stored trench bipolar transistor (CSTBT) during clamped inductive turn-off transient

    Science.gov (United States)

    Xue, Peng; Fu, Guicui

    2017-03-01

    The dynamic avalanche has a huge impact on the switching robustness of carrier stored trench bipolar transistor (CSTBT). The purpose of this work is to investigate the CSTBT's dynamic avalanche mechanism during clamped inductive turn-off transient. At first, with a Mitsubishi 600 V/150 A CSTBT and a Infineon 600 V/200 A field stop insulated gate bipolar transistor (FS-IGBT) utilized, the clamped inductive turn-off characteristics are obtained by double pulse test. The unclamped inductive switching (UIS) test is also utilized to identify the CSTBT's clamping voltage under dynamic avalanche condition. After the test data analysis, it is found that the CSTBT's dynamic avalanche is abnormal and can be triggered under much looser condition than the conventional buffer layer IGBT. The comparison between the FS-IGBT and CSTBT's experimental results implies that the CSTBT's abnormal dynamic avalanche phenomenon may be induced by the carrier storage (CS) layer. Based on the semiconductor physics, the electric field distribution and dynamic avalanche generation in the depletion region are analyzed. The analysis confirms that the CS layer is the root cause of the CSTBT's abnormal dynamic avalanche mechanism. Moreover, the CSTBT's negative gate capacitance effect is also investigated to clarify the underlying mechanism of the gate voltage bump observed in the test. In the end, the mixed-mode numerical simulation is utilized to reproduce the CSTBT's dynamic avalanche behavior. The simulation results validate the proposed dynamic avalanche mechanisms.

  2. DnaN clamp zones provide a platform for spatiotemporal coupling of mismatch detection to DNA replication.

    Science.gov (United States)

    Lenhart, Justin S; Sharma, Anushi; Hingorani, Manju M; Simmons, Lyle A

    2013-02-01

    Mismatch repair (MMR) increases the fidelity of DNA replication by identifying and correcting replication errors. Processivity clamps are vital components of DNA replication and MMR, yet the mechanism and extent to which they participate in MMR remains unclear. We investigated the role of the Bacillus subtilis processivity clamp DnaN, and found that it serves as a platform for mismatch detection and coupling of repair to DNA replication. By visualizing functional MutS fluorescent fusions in vivo, we find that MutS forms foci independent of mismatch detection at sites of replication (i.e. the replisome). These MutS foci are directed to the replisome by DnaN clamp zones that aid mismatch detection by targeting the search to nascent DNA. Following mismatch detection, MutS disengages from the replisome, facilitating repair. We tested the functional importance of DnaN-mediated mismatch detection for MMR, and found that it accounts for 90% of repair. This high dependence on DnaN can be bypassed by increasing MutS concentration within the cell, indicating a secondary mode of detection in vivo whereby MutS directly finds mismatches without associating with the replisome. Overall, our results provide new insight into the mechanism by which DnaN couples mismatch recognition to DNA replication in living cells.

  3. 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.

  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. 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.

  6. [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.

  7. 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.

  8. Blunt injury to the inferior gluteal artery: case report of a rare "near miss" event

    Directory of Open Access Journals (Sweden)

    Chen Wei

    2008-10-01

    Full Text Available Abstract Traumatic injuries of the inferior gluteal artery are rare, the majority of which are aneurysms due to sharp or blunt trauma. We report the rare case of a "near miss" event of a patient with an acute hemorrhagic mass in the right buttock caused by blunt trauma to the inferior gluteal artery without "hard" clinical signs of vascular injury. Despite the unusual presentation, diffuse injury of the inferior gluteal artery branches was diagnosed by ultrasonography and angiography. This article highlights the importance of considering an arterial injury following blunt trauma to the buttock with subsequent pain and swelling. Appreciation of this rare injury pattern is necessary in order to facilitate rapid diagnosis and appropriate treatment.

  9. 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.

  10. Avoiding injury to the inferior alveolar nerve by routine use of intraoperative radiographs during implant placement.

    Science.gov (United States)

    Burstein, Jeffrey; Mastin, Chris; Le, Bach

    2008-01-01

    Injury to the inferior alveolar nerve during implant placement in the posterior atrophic mandible is a rare but serious complication. Although a preoperative computerized tomography scan can help determine the distance from the alveolar ridge to the nerve canal, variables such as magnification errors, ridge anatomy, and operator technique can increase the chance for complications. The routine use of intraoperative periapical radiographs during the drilling sequence is an inexpensive and reliable tool, allowing the operator to confidently adjust the direction and depth of the implant during placement. Most important, it helps avoid the risk of injury to the inferior alveolar nerve in cases in which there is limited vertical alveolar bone. Using this technique for 21 implants placed in the posterior atrophic mandible, with less than 10 mm of vertical bone to the inferior alveolar nerve canal, the authors observed no incidents of postoperative paresthesia.

  11. Variação anatômica venosa rara em membros inferiores

    Directory of Open Access Journals (Sweden)

    Melissa Andreia de Moraes Silva

    Full Text Available Resumo A anatomia do sistema venoso dos membros inferiores é uma das mais complexas no corpo humano. Devido a essa condição, é de extrema importância saber identificar variações que possam acometê-la, como as malformações congênitas. Em casos de agenesia de veias profundas, como uma malformação vascular rara, o quadro clínico pode manifestar-se com insuficiência venosa crônica, que pode evoluir com edema, hiperpigmentação e úlcera de membro inferior. Assim, em muitos casos, torna-se uma doença incapacitante e de difícil tratamento. Apresenta-se um caso de agenesia de segmento venoso femoropoplíteo no membro inferior direito em paciente de 36 anos de idade, que cursou com edema e varizes de grosso calibre no membro acometido.

  12. 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.

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

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    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

  14. Significance of Radiological Variables Studied on Orthopantamogram to Pridict Post-Operative Inferior Alveoler Nerve Paresthesia After Third Molar Extraction

    OpenAIRE

    Pathak, Sachin; Mishra, Nitin; Rastogi, Madhur Kant; Sharma, Shalini

    2014-01-01

    Context: Removal of impacted third molar is a procedure that is often associated with post-operative complications. The rate of complications is somewhat high because of its proximity to the vital structures. Inferior alveolar nerve paresthesia is one of the common complications of impacted their molar surgery. This is due to intimate relationship between roots of mandibular third molar and inferior alveolar canal. To access the proximity of inferior alveolar canal to third molar many diagnos...

  15. 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.

  16. 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.

  17. Estudo comparativo entre dois protocolos anestésicos envolvendo bloqueio do nervo alveolar inferior convencional e de Vazirani-Akinosi para exodontia de terceiro molar inferior

    Directory of Open Access Journals (Sweden)

    Danilo de Paula Ribeiro Borges

    Full Text Available INTRODUÇÃO: O bloqueio do nervo alveolar inferior (BNAI apresenta alta porcentagem de falha na Odontologia. A fim de melhorar esse índice, vêm-se estudando diferentes alternativas, como diferentes técnicas e soluções anestésicas. OBJETIVO: Avaliar duas diferentes técnicas - técnica convencional e de Vazirani-Akinosi - para o bloqueio do nervo alveolar inferior, bem como compará-las quanto à sua efetividade e quantificar o percentual de aspirações positivas nas duas diferentes técnicas. MATERIAL E MÉTODO: Foram avaliados 160 pacientes de ambos os sexos, sendo 80 submetidos ao bloqueio do nervo alveolar inferior de Vazirani-Akinosi e bloqueio do nervo bucal (G1, e 80 submetidos ao bloqueio do nervo alveolar inferior convencional e ao bloqueio do nervo bucal (G2. Em ambos os grupos, utilizou-se a combinação de articaína 4% com epinefrina 1:100.000 para bloqueio do nervo bucal, e lidocaína 2% com epinefrina 1:100.000 para bloqueio do nervo alveolar inferior. Foram avaliados: a quantidade de aspirações positivas, a eficácia da anestesia e o momento em que ocorreu a falha anestésica durante o procedimento cirúrgico. RESULTADO: Não houve diferenças estatisticamente significantes (p = 0,2453 entre os grupos G1 e G2 observando-se a eficácia e o índice de aspirações positivas, e o momento em que ocorreu a falha anestésica, observando-se uma maior eficácia de ambas as técnicas, quando comparadas com a literatura (90% CONCLUSÃO: Não houve diferença significativa entre o BNAI pela técnica convencional e o BNAI pela técnica de Vazirani-Akinosi quanto a quantidade de aspirações positivas e eficácia, sendo que o uso da articaína 4% com epinefrina 1:100.000 no bloqueio do nervo bucal possivelmente aumentou a eficácia anestésica de ambas as técnicas.

  18. Colgajos de perforantes de las arterias epigástricas inferiores profunda y superficial Deep and superficial inferior epigastric artery perforator flaps

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    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

  19. Voltage-clamp studies of transient inward current and mechanical oscillations induced by ouabain in ferret papillary muscle.

    Science.gov (United States)

    Karagueuzian, H S; Katzung, B G

    1982-06-01

    1. We studied the effects of a toxic concentration of ouabain on transmembrane electrical activity and on mechanical behaviour of right ventricular papillary muscles from ferrets in a single sucrose-gap using current clamp and voltage clamp.2. Ouabain (1.4-1.8 muM) induced oscillatory after-potentials and after-concentrations in current-clamp experiments. Voltage clamp showed that the oscillatory after-potential was caused by a transient inward current, similar to that in Purkinje fibres.3. The transient current had a sigmoidal dependence on the preceding (activating) voltage step V1, with a treshold around -13 mV and a plateau between +10 and 20 mV. There was a decline in current amplitude for more positive clamps. When activated by a fixed V1 voltage step, and measured at different repolarization levels V2, the transient current manifested an inverse dependence on V2 between -50 and -10 mV. No outward transient current could be detected. Total replacement of Na in the bathing medium by Tris or by sucrose abolished the transient current.4. Ouabain caused an increase of phasic (twitch) tension responses to voltage steps at all potentials without shifting the curve relating these variables on the voltage axis. The drug evoked an even greater increase in the tonic tension responses.5. After prolonged exposure, oscillatory mechanical responses were frequently recorded during positive voltage steps. Unlike the after-contraction, these mechanical fluctuations were not consistently damped and were not accompanied by detectable synchronous current fluctuations. Catecholamines and dibutyryl cyclic AMP markedly reduced the amplitude of the tonic contraction and the mechanical oscillations but increased their frequency. Caffeine had no effect on the tonic contraction amplitude but abolished the fluctuations.6. These results support the proposal that Ca is transiently released from the overloaded sarcoplasmic reticulum in ouabain-intoxicated muscle and may evoke oscillatory

  20. Perforated patch-clamp analysis of the passive membrane properties of three classes of hippocampal neurons.

    Science.gov (United States)

    Spruston, N; Johnston, D

    1992-03-01

    1. Perforated patch-clamp recordings were made from the three major classes of hippocampal neurons in conventional in vitro slices prepared from adult guinea pigs. This technique provided experimental estimates of passive membrane properties (input resistance, RN, and membrane time constant, tau m) determined in the absence of the leak conductance associated with microelectrode impalement or the washout of cytoplasmic constituents associated with conventional whole-cell recordings. 2. To facilitate comparison of our data with previous results and to determine the passive membrane properties under conditions as physiological as possible, recordings were made at the resting potential, in physiological saline, and without any added blockers of voltage-dependent conductances. 3. Membrane-potential responses to current steps were analyzed, and four criteria were used to identify voltage responses that were the least affected by activation of voltage-dependent conductances. tau m was estimated from the slowest component (tau 0) of multiexponential fits of responses deemed passive by these criteria. RN was estimated from the slope of the linear region in the hyperpolarizing direction of the voltage-current relation. 4. It was not possible to measure purely passive membrane properties that were completely independent of membrane potential in any of the three classes of hippocampal neurons. Changing the membrane potential by constant current injection resulted in changes in RN and tau 0; subthreshold depolarization produced an increase, and hyperpolarization a decrease, in both RN and tau 0 for all three classes of hippocampal neurons. 5. Each of the three classes of hippocampal neurons also displayed a depolarizing "sag" during larger hyperpolarizing voltage transients. To evaluate the effect of the conductances underlying this sag on passive membrane properties, 2-5 mM Cs+ was added to the physiological saline. Extracellular Cs+ effectively blocked the sag in all three

  1. 75 FR 9228 - Draft Guidance for Industry on Non-Inferiority Clinical Trials; Availability

    Science.gov (United States)

    2010-03-01

    ...The Food and Drug Administration (FDA) is announcing the availability of a draft guidance for industry entitled ``Non- Inferiority Clinical Trials.'' This draft guidance provides sponsors and review staff in the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation and Research (CBER) with the agency's interpretation of the underlying principles involved in the......

  2. Randomized Controlled Non-Inferiority Trial of a Telehealth Treatment for Chronic Stuttering: The Camperdown Program

    Science.gov (United States)

    Carey, Brenda; O'Brian, Sue; Onslow, Mark; Block, Susan; Jones, Mark; Packman, Ann

    2010-01-01

    Background: Although there are treatments that can alleviate stuttering in adults for clinically significant periods, in Australia there are barriers to the accessibility and availability of best-practice treatment. Aims: This parallel group, non-inferiority randomized controlled trial with multiple blinded outcome assessments investigated whether…

  3. 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.

  4. 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

  5. [The syndrome of blepharophimosis-ptosis-dystopia of the inferior puncta lacrimalia and epicanthus].

    Science.gov (United States)

    Dumitrache, L

    1991-01-01

    The paper presents a family with 28 members belonging to four generations. 12 of them show an association of blepharophimosis--ptosis--dystopia of the inferior lacrimal points and epicanthus. 9 members of the family in the 3rd and 4th generations were examined and a dominant mode of transmission was evidenced.

  6. Intracellular responses to frequency modulated tones in the dorsal cortex of the mouse inferior colliculus

    NARCIS (Netherlands)

    H.R.A.P. Geis (H.-Rüdiger A.P.); J.G.G. Borst (Gerard)

    2013-01-01

    textabstractFrequency modulations occur in many natural sounds, including vocalizations. The neuronal response to frequency modulated (FM) stimuli has been studied extensively in different brain areas, with an emphasis on the auditory cortex and the central nucleus of the inferior colliculus. Here,

  7. Cementoblastoma benigno associado a segundo pré molar inferior : relato de caso

    OpenAIRE

    Mahl, Carlos Eduardo Winck; Gegler, Aderson; Fontanella, Vania Regina Camargo

    2003-01-01

    0 cementoblastoma benigno é uma lesao produtora de cemento que constitui apenas 1% dos tumores odontogenicos, na maioria dos casos esta associada a molares inferiores e acomete adultos jovens. Relata-se urn caso no qual observa-se uma apresentagao atipica quanto localizacao e faixa etaria.

  8. 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.

  9. Related anomalies of origin of left vertebral and left inferior thyroid arteries

    Energy Technology Data Exchange (ETDEWEB)

    Sartor, K.; Freckmann, N.; Boeker, D.K.

    1981-01-01

    The known rare occurrence of related anomalies of origin of vertebral and inferior thyroid arteries appears not to be documented in the angiographic literature. Three cases with manifestation on the left side are presented. Embryology is discussed briefly. Knowledge of such anomalies is of importance to surgeons as well as angiographers.

  10. Inferior alveolar nerve paresthesia caused by a dentigerous cyst associated with three teeth.

    Science.gov (United States)

    Sumer, Mahmut; Baş, Burcu; Yildiz, Levent

    2007-09-01

    The dentigerous cyst is a common pathologic entity associated with an impacted tooth, usually third molars. They generally are asymptomatic, being found on routine dental radiographic examination. This report describes the case of a 43 year old male with a large dentigerous cyst associated with mandibular canine, first and second premolar teeth that caused paresthesia of the inferior alveolar nerve.

  11. 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.

  12. 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…

  13. 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.)

  14. 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.

  15. 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.

  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.

  17. 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

  18. Fatal thrombotic complications of hepatic cystic compression of the inferior vena: A case report

    Institute of Scientific and Technical Information of China (English)

    Ting-Kai Leung; Chi-Ming Lee; Hsin-Chi Chen

    2005-01-01

    Of 5% of patients who develop liver cysts, only 10-15%of them come for medical attention, typically because of dull right upper quadrant pain, abdominal bloating or early satiety. We treated a 77-year-old female with a rare complication of inferior vena cava thrombosis. The patient expired due to septic shock and multiple organ failure.

  19. "A Hidden Part of Me": Latino/a Students, Silencing, and the Epidermalization of Inferiority

    Science.gov (United States)

    Irizarry, Jason G.; Raible, John

    2014-01-01

    Using Critical Race Theory (CRT) and Latino/a Critical Race Theory (LatCrit) as analytical tools, this article examines the experiences of a seven Latino/a high school students at various points of engagement with the school-to-prison pipeline. Building on and extending Franz Fanon's (1952) concept of the epidermalization of inferiority, the…

  20. 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.