Sample records for compression anastomosis ring

  1. Magnetic compression in gastrointestinal and bilioenteric anastomosis: how much force? (United States)

    Lambe, Tadhg; Ríordáin, Mícheál G Ó; Cahill, Ronan A; Cantillon-Murphy, Pádraig


    The concept of compression alimentary anastomosis is well established. Recently, magnetic axial alignment pressures have been encompassed within such device constructs. We quantify the magnetic compression force and pressure required to successfully achieve gastrointestinal and bilioenteric anastomosis by in-depth interrogation of the reported literature. Reports of successful deployment and proof of anastomotic patency on survival were scrutinized to quantify the necessary dimensions and strengths of magnetic devices in (a) gastroenteral anastomosis in live porcine models and (b) bilioenteric anastomosis in the clinical setting. Using a calculatory tool developed for this work (magnetic force determination algorithm, MAGDA), ideal magnetic force and compression pressure were quantified from successful reports with regard to their variance by intermagnet separation. Optimized ranges for both compression force and pressure were determined for successful porcine gastroenteral and clinical bilioenteric anastomoses. For gastroenteral anastomoses (porcine investigations), an optimized compression force between 2.55 and 3.57 kg at 2-mm intermagnet separation is recommended. The associated compression pressure should not exceed 60 N/cm(2). Successful bilioenteric anastomoses is best clinically achieved with intermagnet compression of 18 to 31 g and associated pressures between 1 and 3.5 N/mm(2) (at 2-mm intermagnet separation). The creation of magnetic compression anastomoses using permanent magnets demonstrates a remarkable resilience to variations in magnetic force and pressure exertion. However, inappropriate selection of compression characteristics and magnet dimensions may incur difficulties. Recommendations of this work and the availability of the free online tool ( may facilitate a factor of robustness in the design and refinement of future devices.

  2. "Tie over ring" sutureless compression based gastrointestinal anastomotic method: experimental rat model. (United States)

    Hiradfar, Mehran; Shojaeian, Reza; Zabolinejad, Nona; Gharavifard, Mohammad; Sabzevari, Alireza; Joodi, Marjan; Yal, Nazila; Saeedi Sharifabad, Parisa; Hajian, Sara; Nazarzadeh, Reza; Lotfinejad, Nasim


    Giving the ever-rising trend of pediatric minimally invasive surgery besides early neonatal surgical interventions, intestinal anastomosis turns out to be a time consuming stage due to several anatomical as well as technical difficulties. A perfect bowel anastomosis method should be easy, rapid, safe and reliable in creation of bowel continuity with minimal tissue damage. In this light, sutureless anastomotic methods have been introduced, using compression based anastomosis with biofragmentable rings or powerful magnets. Accordingly, this experimental animal model study has evaluated the result of an easy, rapid intestinal sutureless anastomotic technique via simple tying over an intraluminal ring, in comparison with conventional handsewn bowel anastomosis. Thirty Wistar-Albino male rats were enrolled and small bowel was transected via a midline laparotomy. A grooved plastic ring was inserted into the ileal lumen and both intestinal cutting ends were fixed over the ring with a simple tie in the first group. On the other hand, enteroenterostomy was performed by the conventional method of handsewn anastomosis in the second group. After 14 days, rats were sacrificed to evaluate for intraperitoneal adhesion and abscess formation in addition to other evidences of anastomotic leakage. Furthermore, the anastomotic site integrity, tensile strength and healing stage were assessed microscopically. The mean operative time and intraoperative bleeding in the tie over ring group were significantly less than those in the handsewn anastomosis group. Anastomotic stricture was more common in the conventional anastomosis group while the anastomotic tensile strength was significantly higher in the tie over ring group. Histopathological healing parameters and final healing score were almost similar in both groups but mean inflammatory cell infiltration in handsewn anastomosis was significantly higher. "Tie over ring" is a simple method of anastomosis that is feasible, fast, safe and

  3. The use of shape memory compression anastomosis clips in cholecystojejunostomy in pigs – a preliminary study

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    Piotr Holak


    Full Text Available This paper reports on the use of compression anastomosis clips (CAC in cholecystoenterostomy in an animal model. Cholecystojejunostomy was performed in 6 pigs using implants made of nickel-titanium alloy in the form of elliptical springs with two-way shape memory. The applied procedure led to the achievement of tight anastomosis with a minimal number of complications and positive results of histopathological evaluations of the anastomotic site. The results of the study indicate that shape memory NiTi clips are a promising surgical tool for cholecystoenterostomy in cats and dogs.

  4. Magnetic compression anastomosis for biliary obstruction: review and experience at Tokyo Medical University Hospital. (United States)

    Itoi, Takao; Kasuya, Kazuhiko; Sofuni, Atsushi; Itokawa, Fumihide; Tsuchiya, Takayoshi; Kurihara, Toshio; Ikeuchi, Nobuhito; Takeuchi, Mami; Nagano, Takeshi; Iwamoto, Hitoshi; Yamanouchi, Eigoro; Shimazu, Motohide; Tsuchida, Akihiko


    Magnetic compression anastomosis (MCA) is a revolutionary, minimally invasive method of performing choledochoenterostomy or choledochocholedochostomy without using surgical techniques in patients with biliary stricture or obstruction. Herein, we describe a case series of MCA for severe biliary stricture or obstruction, which could not be treated with conventional therapies. Two patients with biliary obstruction were treated using MCA for choledochocholedochostomy and choledochoenterostomy at Tokyo Medical University Hospital and Tokyo Medical University Hachioji Medical Center. Endoscopically, a samarium-cobalt (Sm-Co) rare-earth magnet was placed at the superior site of obstruction through the percutaneous transhepatic biliary drainage route and another Sm-Co magnet was placed at the inferior site of obstruction. A comprehensive computer-aided literature search for MCA was performed up to September 2009 by using MEDLINE and EMBASE. MCA techniques enabled complete anastomosis in both cases without procedure-related complications. The MCA technique is a revolutionary method of performing choledochocholedochostomy and choledochoenterostomy interventionally in patients with biliary obstruction, for whom the conventional endoscopic procedure is not available, or in candidates who are deemed unsuitable for surgery.

  5. Intraductal Ultrasonography as a Local Assessment Before Magnetic Compression Anastomosis for Obstructed Choledochojejunostomy. (United States)

    Kawabata, Hideaki; Hitomi, Misuzu; Inoue, Naonori; Kawakatsu, Yukino; Okazaki, Yuji; Miyata, Masatoshi


    Magnetic compression anastomosis (MCA) has been developed as a non-surgical alternative treatment for biliary obstruction without serious complications. A 70-year-old woman who had undergone pancreaticoduodenectomy with modified Child reconstruction for pancreatic head cancer suffered from obstructed choledochojejunostomy with no recurrent findings 4 months after the operation. Cholangiography using the percutaneous transhepatic cholangiographic drainage (PTCD) and fluoroscopy revealed complete obstruction of the upper common bile duct, and the length of the obstruction was 7 mm. Intraductal ultrasonography (IDUS) showed fibrous heterogenous hyperechoic appearance without fluid collection, vessels or foreign bodies at the site of the obstruction. We performed choledochojejunostomy using the MCA technique. One magnet was inserted into the obstruction of the hepatic side through the PTCD fistula. Another was delivered endoscopically to the obstruction of the jejunal side. The two magnets were immediately attracted towards each other transmurally, and reanastomosis was confirmed 7 days after starting the compression. The magnets were easily retrieved endoscopically. A 16-Fr indwelling drainage tube was placed in the jejunum through the PTCD. The internal tube is still in place 6 months after reanastomosis, and no MCA-related complications have been observed. In conclusion, MCA is a safe, effective, low-invasive treatment for biliary obstruction, and IDUS is useful for the pretreatment assessment of feasibility and safety.

  6. Rebound Of Previously Compressed O-Ring (United States)

    Moore, Carleton J.


    Report presents theoretical and experimental analysis of relaxation characteristics of O-ring of vinylidene fluoride/hexafluoropropylene copolymer of same composition used in solid rocket boosters on Space Shuttle flight 51-L. Study covers range of temperatures from 10 to 120 degree F. Presents one-dimensional mathematical model of response provided for both elastic response and creep.

  7. Compression anastomotic ring-locking procedure (CARP) is a safe and effective method for intestinal anastomoses following left-sided colonic resection

    DEFF Research Database (Denmark)

    Vilhjalmsson, Dadi; Appelros, Stefan; Toth, Ervin


    BACKGROUND: Compression anastomotic ring-locking procedure (CARP) is a novel procedure for creating colonic anastomoses. The surgical procedure allows perioperative quantification of the compression pressure between the intestinal ends within the anastomosis and postoperative monitoring of the an......BACKGROUND: Compression anastomotic ring-locking procedure (CARP) is a novel procedure for creating colonic anastomoses. The surgical procedure allows perioperative quantification of the compression pressure between the intestinal ends within the anastomosis and postoperative monitoring...... of 25 patients underwent CARP. CARP was not used in 11 patients due to advanced tumor disease (two cases) and size restrictions (nine cases). No case of anastomotic leakage, bowel obstruction, or stenosis formation was observed. No device-related perioperative adverse events were noted. The surgical....... CONCLUSION: Our results indicate that the novel suture-less CARP is a safe and effective method for creating colonic anastomoses. Further studies are warranted in larger patient populations to compare CARP head-on-head with stapled and/or hand-sewn colonic anastomoses....

  8. Conversion of Vertical Sleeve Gastrectomy to a Functional Single-Anastomosis Gastric Bypass: Technique and Preliminary Results Using a Non-Adjustable Ring Instead of Stapled Division. (United States)

    Greco, Francesco


    Recent data show that some patients will have insufficient weight loss or experience weight regain after sleeve gastrectomy. Dilation of the sleeve over time or use of an inadequate technique may contribute to relapse of morbid obesity. Repeat sleeve gastrectomy is the most obvious option but requires stapling of scarred tissue, has a higher risk of leakage, and is prone to re-enlargement with time. We herein describe a simple and innovative technique with which to revise vertical sleeve gastrectomy (VSG) into functional single-anastomosis gastric bypass (f-SAGB). Twelve VSGs were converted to f-SAGB by placing a GaBP Ring (Bariatec Corp., Palos Verdes Peninsula, CA, USA) at the base of the "sleeve" and performing the anastomosis above the ring. The length of the biliopancreatic loop was chosen according to the volume of the pouch and the patient's residual eating capability. All procedures were completed by laparoscopy and were uneventful. The average decrease in the body mass index was from 41.0 to 29.5 kg/m2 at the 12-month follow-up. No ring-related complications were reported. f-SAGB is a low-risk and effective option with which to revise VSG in patients with inadequate weight loss. Avoiding detachment of the pouch from the antrum assures full reversibility of the procedure and preserves the chance to explore the remnant stomach and biliary tree.

  9. A new cladding embrittlement criterion derived from ring compression tests

    Energy Technology Data Exchange (ETDEWEB)

    Herb, Joachim, E-mail:; Sievers, Jürgen, E-mail:; Sonnenburg, Heinz-Günther, E-mail:


    Highlights: • Using FEM it was possible to simulate measured ring compression test data. • The FEM provides burst stresses from Zry-4, M5 and ZIRLO cladding. • The ratio of burst stresses to yield stresses was correlated. • The ratio depends linearly on the state of oxidation and hydriding. • The ratio of stresses at unity can be applied as embrittlement criterion. - Abstract: It is of regulatory interest to prevent the breaking of fuel rods in LOCA transients. In current regulations this is accomplished by limiting the oxidation during LOCA to such an extent that still some residual ductility is preserved in the fuel rod cladding. The current oxidation limit in German as well as in US regulations is set to 17% ECR (Equivalent Cladding Reacted) which aims at maintaining a residual ductility for oxidized claddings. Recent ANL tests have shown that the combination of both oxidation and additionally hydrogen up-take affects the transition to zero-ductility. Furthermore, the oxidation during LOCA transient is accompanied by a significant up-take of hydrogen (secondary hydriding) if the fuel rod bursts during this transient. This secondary hydriding affects the cladding in the vicinity of the burst opening. These findings necessitate a new criterion for preserving cladding's strength. This paper describes a method how to derive a criterion which assures the required residual mechanical strength of the cladding for LOCA transients. This method utilizes the experimental results of 102 ring compression tests (RCT) conducted at ANL and KIT. RCTs of various cladding materials, oxidation levels and hydrogen content were considered. The basic approach was to compare the RCT test data with finite element analyses using the code ADINA. Starting with the cladding oxidation model of Leistikov, both the layer structure of the cladding and the distribution of the oxygen among these layers were determined. The mechanical properties of these layers were taken from

  10. The ITER pre-compression rings – A first in cryogenic composite technology

    Energy Technology Data Exchange (ETDEWEB)

    Rajainmaki, Hannu; Fanthome, John; Losasso, Marcello [Fusion for Energy, C/ Josep Pla, n. 2, E-08019 Barcelona (Spain); Foussat, Arnaud [ITER Organisation, 13108 St. Paul-lez-Durance (France); Rodriguez, Jesus [EADS CASA Espacio S.L., Av. de Aragón 404, E-28022 Madrid (Spain); Evans, David; Diaz, Victor [Advanced Cryogenic Materials Ltd, Abingdon, OX14 2HQ (United Kingdom)


    The ITER Pre-Compression Rings represent one of the heaviest composite structures ever manufactured as a single piece and the largest - the outer diameter will be above 5.5 meters - intended for use in a cryogenic environment. With a cross section of 337 mm × 288 mm, each item will weigh more than 3,000 kg. A development program, based on filament wound and dry wound S2 glass unidirectional fibers, the latter processed by VARTM, was completed on one fifth scale rings, and these materials and techniques were shown to be satisfactory. The paper describes how a technology applied to build up primary structures of European launchers is being accommodated to produce the ITER Pre-Compression Rings, fulfilling its extremely challenging requirements. In addition, we will describe how the structural analysis is correlated with the test results of scaled down rings, as well as how the pre-compression rings’ manufacturing process will be qualified.

  11. Ring artifacts correction in compressed sensing tomographic reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Paleo, Pierre, E-mail: [ESRF, 71 Avenue des Martyrs, 38000 Grenoble (France); Université de Grenoble, Gipsa-Lab, 11 Rue des Mathématiques, 38400 Saint-Martin-d’Hères (France); Mirone, Alessandro, E-mail: [ESRF, 71 Avenue des Martyrs, 38000 Grenoble (France)


    The formalism of iterative tomographic reconstruction with sparsity inducing penalty is extended to enable ring artifacts correction. Ring artifacts are a very common problem in tomographic reconstruction, and numerous methods exist to either pre-process the sinogram or correct the reconstructed slice. A novel approach to perform the correction as part of the reconstruction process is presented. It is shown that for iterative techniques, which amount to optimizing an objective function, the ring artifacts correction can be easily integrated in the formalism, enabling simultaneous slice reconstruction and ring artifacts correction. This method is tested and compared with mainstream correction techniques for both simulated and experimental data. Results show that the correction is efficient, especially for undersampled datasets. This technique is included in the PyHST2 code which is used at the European Synchrotron Radiation Facility for tomographic reconstruction.

  12. Wafer-level packaging with compression-controlled seal ring bonding (United States)

    Farino, Anthony J


    A device may be provided in a sealed package by aligning a seal ring provided on a first surface of a first semiconductor wafer in opposing relationship with a seal ring that is provided on a second surface of a second semiconductor wafer and surrounds a portion of the second wafer that contains the device. Forcible movement of the first and second wafer surfaces toward one another compresses the first and second seal rings against one another. A physical barrier against the movement, other than the first and second seal rings, is provided between the first and second wafer surfaces.

  13. Multispectral tissue characterization for intestinal anastomosis optimization (United States)

    Cha, Jaepyeong; Shademan, Azad; Le, Hanh N. D.; Decker, Ryan; Kim, Peter C. W.; Kang, Jin U.; Krieger, Axel


    Intestinal anastomosis is a surgical procedure that restores bowel continuity after surgical resection to treat intestinal malignancy, inflammation, or obstruction. Despite the routine nature of intestinal anastomosis procedures, the rate of complications is high. Standard visual inspection cannot distinguish the tissue subsurface and small changes in spectral characteristics of the tissue, so existing tissue anastomosis techniques that rely on human vision to guide suturing could lead to problems such as bleeding and leakage from suturing sites. We present a proof-of-concept study using a portable multispectral imaging (MSI) platform for tissue characterization and preoperative surgical planning in intestinal anastomosis. The platform is composed of a fiber ring light-guided MSI system coupled with polarizers and image analysis software. The system is tested on ex vivo porcine intestine tissue, and we demonstrate the feasibility of identifying optimal regions for suture placement.

  14. Long-term compression effects on elastomeric O-ring behavior (United States)

    Clinton, R. G.; Turner, J. E.


    This paper discusses the results of testing performed on elastomeric seal materials that had been under compression for extended periods of time. Elastomeric seals used in the Space Shuttle redesigned solid rocket motors can experience compression times of up to six months. These seals must be capable of sealing internal motor pressure upon ignition. The tests described herein were performed in order to verify that the seals, which had experienced long-term compression could seal throughout motor operation. Testing was divided into two phases: (1) dynamic high pressure testing, and (2) resiliency testing. Dynamic testing was performed using specialized test fixtures that allowed simulation of the field joint movements during initial motor operation along with high pressure gas. Resiliency testing was performed using specialized test fixtures that also simulated field joint movements and also had the ability to measure the sealing force of the O-ring. Results from all testing indicated that the current elastomeric seals used in the redesigned solid rocket motors will seal during motor operations in the currently defined launch environments.

  15. Comparison of ring compression testing to three point bend testing for unirradiated ZIRLO cladding

    Energy Technology Data Exchange (ETDEWEB)

    None, None


    Safe shipment and storage of nuclear reactor discharged fuel requires an understanding of how the fuel may perform under the various conditions that can be encountered. One specific focus of concern is performance during a shipment drop accident. Tests at Savannah River National Laboratory (SRNL) are being performed to characterize the properties of fuel clad relative to a mechanical accident condition such as a container drop. Unirradiated ZIRLO tubing samples have been charged with a range of hydride levels to simulate actual fuel rod levels. Samples of the hydrogen charged tubes were exposed to a radial hydride growth treatment (RHGT) consisting of heating to 400°C, applying initial hoop stresses of 90 to 170 MPa with controlled cooling and producing hydride precipitates. Initial samples have been tested using both a) ring compression test (RCT) which is shown to be sensitive to radial hydride and b) three-point bend tests which are less sensitive to radial hydride effects. Hydrides are generated in Zirconium based fuel cladding as a result of coolant (water) oxidation of the clad, hydrogen release, and a portion of the released (nascent) hydrogen absorbed into the clad and eventually exceeding the hydrogen solubility limit. The orientation of the hydrides relative to the subsequent normal and accident strains has a significant impact on the failure susceptability. In this study the impacts of stress, temperature and hydrogen levels are evaluated in reference to the propensity for hydride reorientation from the circumferential to the radial orientation. In addition the effects of radial hydrides on the Quasi Ductile Brittle Transition Temperature (DBTT) were measured. The results suggest that a) the severity of the radial hydride impact is related to the hydrogen level-peak temperature combination (for example at a peak drying temperature of 400°C; 800 PPM hydrogen has less of an impact/ less radial hydride fraction than 200 PPM hydrogen for the same thermal

  16. Investigation on thermal oxidative aging of nitrile rubber (NBR) O-rings under compression stress (United States)

    Liu, X. R.; Zhang, W. F.; Lou, W. T.; Huang, Y. X.; Dai, W.


    The degradation behaviors of nitrile rubber O-rings exposure to air under compression were investigated at three elevated temperatures. The physical and mechanical properties of the aging samples before and after exposure at selected time were studied by measuring weight loss, tensile strength and elongation at break. The Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and fracture morphology were used to reveal the microstructural changes of the aging samples. The results indicate that the weight decreased with exposure time and temperature. Based on the results of the crosslinking density, the crosslinking predominates during the most of aging process. The significant changes in tensile strength and elongation at break also indicate the severe degradation in air. The fracture morphology results show that the fracture surface after 64 days of exposure to air turns rough and present defects. The ATR-FTIR results demonstrate that the hydroxyl groups were formed for the samples aged in air.

  17. Traumatic Testicular Dislocation Associated with Lateral Compression Pelvic Ring Injury and T-Shaped Acetabulum Fracture

    Directory of Open Access Journals (Sweden)

    Daniel Howard Wiznia


    Full Text Available We report a case of a unilateral testicular dislocation to the superficial inguinal region associated with a lateral compression type pelvic ring injury (OTA classification 61-C3.3a2, b2, c3 and left T-shaped acetabulum fracture (OTA classification 62-B2 in a 44-year-old male who was in a motorcycle accident. The testicular dislocation was noted during the emergency department primary survey, and its location and viability were verified with ultrasound. The testicle was isolated during surgical stabilization of the left acetabulum through a Pfannenstiel incision and modified-Stoppa approach and returned through the inguinal canal to the scrotum. In follow-up, the patient did not suffer urologic or sexual dysfunction. All motorcycle collision patients presenting with pelvic ring injuries or acetabulum fractures should be worked up for possible testicular dislocation with a scrotal exam. Advanced imaging and a urologic consult may be necessary to detect and treat these injuries.

  18. Compression of 200 GHz DWDM channelized TDM pulsed carrier from optically modelocking WRC-FPLD fiber ring at 10 GHz. (United States)

    Lin, Yu-Chan; Peng, Guo-Hsuan; Lin, Gong-Ru


    The compression of 200GHz DWDM channelized optically mode-locking WRC-FPLD fiber ring pulse of at 10 GHz is performed for high-capacity TDM application. To prevent temporal and spectral cross-talk, the duty-cycle of the DWDM channelized WRC-FPLD FL pulse needs to be shortened without broadening its linewidth. With dual-cavity configuration induced DWDM channelization, a shortest single-channel WRC-FPLD FL pulsewidth of 19 ps is generated, which can be linearly compensated to 10 ps and fifth-order soliton compressed to 1.4 ps. Under a maximum pulsewidth compression ratio up to 14 and a +/-100 m tolerance on compressing fiber length, the single-channel pulsewidth remains DWDM channelized WRC-FPLD FL pulsed carrier is approaching 1% to satisfy at least 256 optical TDM channels.

  19. Ge nanobelts with high compressive strain fabricated by secondary oxidation of self-assembly SiGe rings

    DEFF Research Database (Denmark)

    Lu, Weifang; Li, Cheng; Lin, Guangyang


    Curled Ge nanobelts were fabricated by secondary oxidation of self-assembly SiGe rings, which were exfoliated from the SiGe stripes on the insulator. The Ge-rich SiGe stripes on insulator were formed by hololithography and modified Ge condensation processes of Si0.82Ge0.18 on SOI substrate. Ge...... nanobelts under a residual compressive strain of 2% were achieved, and the strain should be higher before partly releasing through bulge islands and breakage of the curled Ge nanobelts during the secondary oxidation process. The primary factor leading to compressive strain is thermal shrinkage of Ge...

  20. Study on Hot Ring Compression Test of Nimonic 115 Superalloy Using Experimental Observations and 3D FEM Simulation (United States)

    Shahriari, D.; Amiri, A.; Sadeghi, M. H.


    In hot forging of Nimonic 115, it is desirable to determine friction coefficients. Changing magnitudes of temperature and type of lubricant at the surface of the workpiece and dies influence friction coefficient. This paper describes an experimental investigation of friction under hot forging conditions using the ring compression test. The 3D FEM simulations were used to derive the friction calibration curves and to evaluate material deformation, geometric changes, and load-displacement results. A series of ring compression tests were carried out to obtain friction coefficients for a number of lubricants including mica plate, glass powder, graphite powder, and dry condition. The experiments show how the variations in temperature at the interface affected frictional behavior. On the basis of these results, mica is recommended for hot forging of Nimonic 115 and its friction coefficient is approximately 0.3.

  1. Abdominal compression during endoscopy (the Bolster technique) demonstrates hidden Schatzki rings (with videos). (United States)

    Jouhourian, Caroline; Bonis, Peter A; Guelrud, Moises


    Schatzki rings are found in the distal esophagus, are associated with hiatal hernias, and present with intermittent dysphagia to solid foods. They can be identified by radiology (GI series or barium swallow studies) or endoscopy. Rings are not always visualized during endoscopy in patients in whom they are suspected clinically. The Bolster technique involves application of epigastric abdominal pressure, which offers the potential to reveal a Schatzki ring that is otherwise obscured within a reduced hiatal hernia. The aim of this study was to determine whether the Bolster technique improves endoscopic detection of Schatzki rings. We reviewed 30 symptomatic patients with a history of a Schatzki ring in a tertiary care center. The Bolster technique was applied to patients in whom the ring was not visible during standard endoscopy. The main outcome measurement was identification of the Schatzki ring after the Bolster technique. A Schatzki ring was visible during standard endoscopy in 26 of the 30 patients. In the remaining 4, the ring was visible only after the application of the Bolster technique. The Bolster technique is a simple maneuver that can increase detection rates of Schatzki rings during endoscopy. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  2. False urethral anastomosis

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    M Kumar Prabhu


    Full Text Available We present images of three cases with false urethral anastomosis following urethroplasty. The likely causes are inadequate posterior urethral dissection and blind use of Hey Grove dilator. We recommend use of antegrade flexible cystoscopy to prevent this complication.

  3. Photonic compressive sensing with a micro-ring-resonator-based microwave photonic filter

    DEFF Research Database (Denmark)

    Chen, Ying; Ding, Yunhong; Zhu, Zhijing


    A novel approach to realize photonic compressive sensing (CS) with a multi-tap microwave photonic filter is proposed and demonstrated. The system takes both advantages of CS and photonics to capture wideband sparse signals with sub-Nyquist sampling rate. The low-pass filtering function required...


    Directory of Open Access Journals (Sweden)

    Fadhlika Ridha


    Full Text Available Pada proses pembuatan pupuk di PKT-5, berbagai gas limbah berbahaya dimusnahkan dengan cara membakarnya melalui Flare, sebelum terbakar di Flare gas-gas tersebut dialirkan dan ditampung pada sebuah Vessel bertekanan atau biasa disebut Vessel High Pressure Flare Knock Out Drum. Dalam perancangan konstruksinya perlu dilakukan analisis sehingga desain dari vessel tersebut sesuai dengan yang diharapkan dan aman untuk dioperasikan. Penelitian ini dilakukan dengan mensimulasikan desain dari Vessel KO Drum menggunakan perhitungan manual sesuai 2007 ASME BPVC Section VIII Division 1 dan Software Compress 6258. Perhitungan dilakukan pada desain head, shell, saddle, nozzle, stiffener ring secara manual dan menggunakan software untuk mengetahui tegangan-tegangan yang terjadi. Selanjutnya dari kedua metode tersebut akan dibandingan hasil perhitungan manual & software.

  5. The significance of compression wood in restoration of the leader in Pinus sihestris L. damaged by moose (Alces alces. II. Structure of growth rings in regenerating stems in relation to juvenile wood formation

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    B. A. Molski


    Full Text Available The corewood of pine ds very prone to compression wood formation, this changing the whole pattern of the tree ring structure and the of early and late wood. Compression wood always increases the formation of late wood at the expense of early wood. Tree rings with compression wood are generally wider than those without it, but there occur also tree rings wihout compression wood wider than those in which it is present, formed in the same year and in the same tree.

  6. Simultaneous anterior and posterior compression of the pelvic ring with external fixation using a pre-tensed curved bar: A biomechanical study. (United States)

    Queipo-de-Llano, Alfonso; Perez-Blanca, Ana; Ezquerro, Francisco; Luna-González, Felipe


    External fixators continue to be essential tools in the urgent treatment of pelvic fractures for compression and stabilization of the pelvic ring. Current systems fail to produce simultaneous anterior and posterior compression. A modified application of an existing curved bar fixator is proposed using a specifically designed tensioner to pre-tense the bar prior to its connection to Schanz screws. Subsequent pre-tension release and elastic recovery of the bar could potentially compress the pelvis. The aim of this work was to determine if the modified application could produce greater simultaneous compression across the sacroiliac joint and the symphysis of an unstable fractured pelvis than the standard application without pretension. Six synthetic pelvis models with symphyseal and unilateral sacroiliac joints disruptions, simulating a Tile type C pelvic ring fracture, were used. Each specimen was stabilized using two 5mm×250mm supra-acetabular Schanz pins, a couple of open adjustable clamps and a semicircular carbon fibre rod applied without and with pre-tension. Two distances from bar to bone and three levels of pretension were compared. Each pelvis was tested with the six possible parameter combinations. Compressive forces at the disrupted joints were measured using pressure sensitive film sensors. The modified application produced forces significantly higher than the minimal compression achieved with standard application. At the sacroiliac joint, after pre-tension release, mean compressive forces measured ranged from 28.7 to 85.6N. The closest bar-to-bone distance always produced a significantly higher force; similarly, a significant increase in compression was found as the pre-tension level rose. At the symphysis, mean compressive forces between 35.3N and 49.0N were determined. No significant variations were seen with changes of any of the two factors analyzed To pre-tense a semi-circular bar before its use for external fixation of the fractured pelvis, is an

  7. Modified Continuous Loop Technique for microvascular anastomosis

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    Kumar Pramod


    Full Text Available A modified method of continuous loop technique for microvascular anastomosis is described. The handling of loop is easier & even last suture is placed under vision. This makes the microvascular anastomosis easier and simpler.

  8. Effect of nepheline syenite particle size on diametrical compression strength and reliability of extruded ceramic Raschig rings used in packed towers

    Energy Technology Data Exchange (ETDEWEB)

    Salem, A.; Rostami, N.


    In order to understand the effect of nepheline syenite particle size on physico-chemical properties of ceramic Raschig rings, the fluxing agent was grinded at different milling times. The compositions were prepared by blending the illitic-kaolinitic clay and pre-grinded particles. The rings were shaped by a laboratory extruder and then were sintered at 1200 degree centigrade. The mechanical reliability of sintered specimens was mathematically described by Weibull theory and the effect of pre-grinding of fluxing agent on Weibull modulus was evaluated by measuring the diametrical compression strength. Weibull modulus and strength were the criteria for selecting the suitable particle size range of nepheline syenite. It was found that the pre-grinding of nepheline syenite acts as fairly strong parameter on microstructure of rings. The investigation concludes that reliable rings can be fabricated if the particle size of nepheline syenite is arranged between 53 and 75 {mu}m. This enhancement in reliability is valuable in packed towers. (Author)

  9. Effect of nepheline syenite particle size on diametrical compression strength and reliability of extruded ceramic Raschig rings used in packed towers

    Energy Technology Data Exchange (ETDEWEB)

    Salem, A.; Rostami, N.


    In order to understand the effect of nepheline syenite particle size on physico-chemical properties of ceramic Raschig rings, the fluxing agent was grinded at different milling times. The compositions were prepared by blending the illitic-kaolinitic clay and pre-grinded particles. The rings were shaped by a laboratory extruder and then were sintered at 1200 degree centigrade. The mechanical reliability of sintered specimens was mathematically described by Weibull theory and the effect of pre-grinding of fluxing agent on Weibull modulus was evaluated by measuring the diametrical compression strength. Weibull modulus and strength were the criteria for selecting the suitable particle size range of nepheline syenite. It was found that the pre-grinding of nepheline syenite acts as fairly strong parameter on microstructure of rings. The investigation concludes that reliable rings can be fabricated if the particle size of nepheline syenite is arranged between 53 and 75 {mu}m. This enhancement in reliability is valuable in packed towers. (Author) 17 refs.

  10. Supramicrosurgical lymphatic-venous anastomosis for postsurgical subcutaneous lymphocele treatment. (United States)

    Gentileschi, Stefano; Servillo, Maria; Salgarello, Marzia


    Postsurgical subcutaneous lymphocele is caused by accidental lesion of a lymphatic vessel that keeps on flowing lymph under the scar. Traditional treatments include aspiration and compression, with probable recurrence, and sclerotherapy which destroys both lymphatic cyst and vessel, creating risk of lymphedema. We describe the case of a postsurgical subcutaneous lymphocele of the left leg that was treated by supramicrosurgical lympatic-venous anastomosis. A single anastomosis was performed end-to-end, between one lymphatic vessel, individuated through indocyanine green lymphography, and one subcutaneous vein, distally to the lymphocele, under sedation and local anesthesia. Postoperative course was uneventful; the lymphocele completely resolved and never recurred during the nine months followup. This technique may heal the lymphocele with no impairing of lymph drainage function. © 2015 Wiley Periodicals, Inc.

  11. Comparative Study of High Powerful Magnet with Conventional Repair of Suture in the Intestinal Anastomosis of Rats

    Directory of Open Access Journals (Sweden)

    Marjan Joudi


    Full Text Available Background In this study, given the importance of gastrointestinal anastomosis in surgical procedures, attempts have been made to compare the results of employing magnetic compression anastomosis and magnetic coils in intestinal anastomosis of rats. Materials and Methods This study was an experimental trial on 60 rats which had been randomly divided into two experiment (30 and control (30 groups. First, the rat intestine was cut off from a relatively fixed point and then magnet anastomosis was performed at the both ends of bowel in the control group and manual suture in the experiment group.  Anastomosis was then examined 10 days after the surgery for possible complications with a histological analysis of the indices of tissue repair. Results The mean time required for performing anastomosis of the rat intestine was 735 and 366 seconds for the control and experiment groups, respectively. Also, the laparotomy performed 10 days after the first operation did not show any significant difference between two groups in terms of surgical complications such as infiltration factor of inflammatory cell and fibroblast activity (P>0.05. The microscopic examination indicated that the tissue reaction in the anastomosis site was better in terms of tissue repair of neo-angiogenesis intestine and collagen deposition in the magnet group(P>0.05.   Conclusion Given the shorter duration of the anastomosis by magnets and more favorable histological results reported in the experiment group, as well as the lack of any significant difference in complications of the two techniques, magnetic compressive anastomosis can be used as a new technique for intestinal surgeries and pertaining anastomosis. Although, we recommend that study will be done with large sample size to obtain reliable results.

  12. The preparation of anastomosis site at the insular segment of middle cerebral artery. (United States)

    Katsuno, Makoto; Tanikawa, Rokuya; Izumi, Naoto; Hashimoto, Masaaki


    An anastomosis at the insular segment of the middle cerebral artery (M2) is often required in cerebral reconstruction with high- or low-flow bypass. It is necessary to create a shallow, wide, fixed, and bloodless anastomosis field to achieve a safe and quick anastomosis for low surgical morbidity. We describe a method to perform a safe and quick anastomosis. From 2009 to 2013, the technique was used in 20 procedures to create an extracranial M2 high-flow bypass. The Sylvian fissure was dissected wide open to expose the M2. A silicon sheet was laid under M2 and the absorbable gelatin-compressed sponges were inserted between M2 and the insula cortex to lift up the M2 and fix it. The rolling surgical sheets were placed at each edge of the dissected Sylvian fissure, instead of brain spatulas. Finally, a small suction tube was placed at the Sylvian fissure and cerebrospinal fluid was continuously sucked. The postoperative patency of the bypass was evaluated by three-dimensional computed tomographic angiography (3D-CTA) in the acute and chronic stages. In all cases, the operation field acquired for the anastomosis was adequate. The average time required for the procedure was 19 min 27 s. Good patency of all high-flow grafts was confirmed by postoperative three-dimensional computed tomography angiography (3D-CTA). In our series, there were no technical complications related to the anastomosis at M2 performed according to our method.

  13. Autologous fibrin adhesive in experimental tubal anastomosis. (United States)

    Rajaram, S; Rusia, U; Agarwal, S; Agarwal, N


    To evaluate autologous fibrin in rabbit oviduct anastomosis versus 7-0 vikryl, a conventional suture material used in tubal anastomosis. Thrombin was added to the autologous fibrinogen at the site of anastomosis to obtain a tissue adhesive. The anastomotic time, pregnancy rate, and litter size were evaluated. Three months later, a relaparotomy was done to evaluate patency and degree of adhesions, and a tubal biopsy was taken from the site of anastomosis. Analysis of results showed a statistically significant (P < .001) shortened anastomotic time and superior histopathological union in the tissue adhesive group. Patency rate, pregnancy rate, and degree of adhesions were comparable in both groups.

  14. Advantages of handsewn over stapled bowel anastomosis. (United States)

    Dziki, A J; Duncan, M D; Harmon, J W; Saini, N; Malthaner, R A; Trad, K S; Fernicola, M T; Hakki, F; Ugarte, R M


    Bowel anastomoses are conventionally performed using a handsewn technique or a stapling device. Each has potential benefits and disadvantages. The most clinically significant complications of the bowel anastomosis are anastomotic leakage and stricture formation. The indices of healing and tissue cohesion were compared dynamically over time in 24 dogs randomized to undergo either a standard two-layer handsewn anastomosis or a stapled anastomosis with the Premium CEEA (United States Surgical Corporation, Norwalk, CT). Animals were sacrificed at 1, 4, 7, and 28 days postoperatively. Each anastomosis was evaluated for anastomotic index, burst pressure, collagen content, and histologic appearance. The anastomotic index was similar on postoperative day (POD) 1, 4, and 7; but on day 28 all handsewn anastomoses had larger diameters than the widest CEEA anastomosis. Burst pressure was higher in handsewn anastomoses at all intervals. Collagen content tended to be higher on POD 7 in the CEEA anastomoses. Histological evaluation showed more complete epithelialization and less inflammation in handsewn anastomoses on POD 28. The higher level of collagen in the CEEA anastomoses on POD 7 may be implicated in the tendency toward stricture formation found with this type of anastomosis. This study demonstrates that the greater speed and ease of the stapled anastomosis is offset by the greater strength, reduced tendency to stricture, and more complete healing of the handsewn anastomosis.

  15. Non-suture methods of vascular anastomosis

    NARCIS (Netherlands)

    Zeebregts, CJ; Heijmen, RH; van den Dungen, JJ; van Schilfgaarde, R

    Background: The main aim of performing a vascular anastomosis is to achieve maximal patency rates. An important factor to achieve that goal is to minimize damage to the vessel walls. Sutures inevitably induce vascular wall damage, which influences the healing of the anastomosis. Over time, several

  16. Effect of nepheline syenite particle size on diametrical compression strength and reliability of extruded ceramic Raschig rings used in packed towers

    Directory of Open Access Journals (Sweden)

    Salem, Amin


    Full Text Available In order to understand the effect of nepheline syenite particle size on physico-chemical properties of ceramic Raschig rings, the fluxing agent was grinded at different milling times. The compositions were prepared by blending the illitic-kaolinitic clay and pre-grinded particles. The rings were shaped by a laboratory extruder and then were sintered at 1200 ºC. The mechanical reliability of sintered specimens was mathematically described by Weibull theory and the effect of pre-grinding of fluxing agent on Weibull modulus was evaluated by measuring the diametrical compression strength. Weibull modulus and strength were the criteria for selecting the suitable particle size range of nepheline syenite. It was found that the pre-grinding of nepheline syenite acts as fairly strong parameter on microstructure of rings. The investigation concludes that reliable rings can be fabricated if the particle size of nepheline syenite is arranged between 53 and 75 μm. This enhancement in reliability is valuable in packed towers.Para conocer el efecto del tamaño de partícula de nefelina sienita sobre las propiedades fisicoquímicas de los anillos Raschig cerámicos, este fundente fue molido a diferentes tiempos. Las composiciones se prepararon mediante la mezcla de la arcilla caolinítica illitica y las partículas pre-molidas. Los anillos se obtuvieron en una extrusora de laboratorio y luego fueron sinterizados a 1200 ºC. La fiabilidad mecánica de las muestras sinterizadas se describe matemáticamente por la teoría de Weibull y el efecto de pre-molienda del fundente en el módulo de Weibull se evaluó midiendo la resistencia a la compresión diametral. El módulo de Weibull y la resistencia fueron los criterios para seleccionar el rango de tamaño de partícula adecuado de nefelina sienita para la fabricación de los anillos que se determinó estaba entre 53 y 75 μm comprobándose que influye considerablemente en la microestructura de los mismos. La

  17. Device For Testing Compatibility Of An O-Ring (United States)

    Davis, Dennis D.


    Fixture designed for use in exposing compressed elastomeric O-ring or other ring seal to test fluid. Made of metal or plastic, with threaded recess into which O-ring placed. Opposite threaded end is opening through which test fluid introduced and placed in contact with O-ring. After exposure, compression set and swell or shrinkage of ring measured. Fixture set to compress ring by selected amount, providing for reproducible compression.

  18. Primary small bowel anastomosis in generalised peritonitis

    NARCIS (Netherlands)

    deGraaf, JS; van Goor, Harry; Bleichrodt, RP

    Objective: To find out if primary small bowel anastomosis of the bowel is safe in patients with generalised peritonitis who are treated by planned relaparotomies. Design: Retrospective study. Setting: University hospital, The Netherlands. Subjects. 10 Patients with generalised purulent peritonitis

  19. Patent blue dye in lymphaticovenular anastomosis. (United States)

    Yap, Yan Lin; Lim, Jane; Shim, Timothy W H; Naidu, Shenthilkumar; Ong, Wei Chen; Lim, Thiam Chye


    Lymphaticovenular anastomosis (LVA) has been described as a treatment of chronic lymphoedema. This microsurgical technique is new and technically difficult. The small caliber and thin wall lymphatic vessels are difficult to identify and easily destroyed during the dissection. We describe a technique of performing lymphaticovenular anastomosis with patent blue dye enhancement. Our patient is a 50-year-old lady who suffers from chronic lymphoedema of the upper limb after mastectomy and axillary clearance for breast cancer 8 years ago. Patent blue dye is injected subdermally and is taken up readily by the draining lymphatic channels. This allows for easy identification of their course. The visualisation of the lumen of the lymphatic vessel facilitates microsurgical anastomosis. The patency of the anastomosis is also demonstrated by the dynamic pumping action of the lymphatic within the vessels. Patent blue dye staining during lymphaticovenular anastomosis is a simple, effective and safe method for mapping suitable subdermal lymphatics, allowing for speedier dissection of the lymphatic vessels intraoperatively. This technique also helps in the confirmation of the success of the lymphaticovenular anastomosis.

  20. Morbidity Following Coloanal Anastomosis: A Comparison of Colonic J-Pouch vs Straight Anastomosis. (United States)

    Brown, Shaun; Margolin, David A; Altom, Laura K; Green, Heather; Beck, David E; Kann, Brian R; Whitlow, Charles B; Vargas, Herschel David


    Low rectal tumors are often treated with sphincter-preserving resection followed by coloanal anastomosis. The purpose of this study was to compare the short-term complications following straight coloanal anastomosis vs colonic J-pouch anal anastomosis. Patients were identified who underwent proctectomy for rectal neoplasia followed by coloanal anastomosis in the 2008 to 2013 American College of Surgeons National Surgical Quality Improvement Program database. Demographic characteristics and 30-day postoperative complications were compared between groups. A national sample was extracted from the American College of Surgeons National Surgical Quality Improvement Project database. Inpatients following proctectomy and coloanal anastomosis for rectal cancer were selected. Demographic characteristics and 30-day postoperative complications were compared between the 2 groups. One thousand three hundred seventy patients were included, 624 in the straight anastomosis group and 746 in the colonic J-pouch group. Preoperative characteristics were similar between groups, with the exception of preoperative radiation therapy (straight anastomosis 35% vs colonic J-pouch 48%, p = 0.0004). Univariate analysis demonstrated that deep surgical site infection (3.7% vs 1.4%, p = 0.01), septic shock (2.25% vs 0.8%, p = 0.04), and return to the operating room (8.8% vs 5.0%, p = 0.0006) were more frequent in the straight anastomosis group vs the colonic J-pouch group. Major complications were also higher (23% vs 14%, p = 0.0001) and length of stay was longer in the straight anastomosis group vs the colonic J-pouch group (8.9 days vs 8.1 days, p = 0.02). After adjusting for covariates, major complications were less following colonic J-pouch vs straight anastomosis (OR, 0.57; CI, 0.38-0.84; p = 0.005). Subgroup analysis of patients who received preoperative radiation therapy demonstrated no difference in major complications between groups. This study had those limitations inherent to a

  1. O-Ring-Testing Fixture (United States)

    Turner, James E.; Mccluney, D. Scott


    Fixture tests O-rings for sealing ability under dynamic conditions after extended periods of compression. Hydraulic cylinder moves plug in housing. Taper of 15 degrees on plug and cavity of housing ensures that gap created between O-ring under test and wall of cavity. Secondary O-rings above and below test ring maintain pressure applied to test ring. Evaluates effects of variety of parameters, including temperature, pressure, rate of pressurization, rate and magnitude of radial gap movement, and pretest compression time.

  2. CO2 - Laser Intestinal Anastomosis Histological And Manometric Study (United States)

    Rabau, Micha Y.; Goldman, Gideon; Bar-Nea, Lilian; Wiznitzer, Theodor; Rochkind, Semion


    Low energy CO2 laser was used to perform intestinal anastomosis by means of tissue welding in 10 Wistar rats. The post operative course in the studied animals was uneventful. The integrity of the anastomosis was investigated manometrically, immediately upon completion of the anasto-mosis and twenty days later. Ten Wistar rats served as control in which conventional interrupted one-layer anastomosis was performed. The results show a significant superior-ity (Phistological examinations up to 90 days following surgery revealed complete healing and epithelialization of the anastomotic site. The technical details of the CO2 laser anastomosis are described.

  3. Robot-sewn ileoileal anastomosis during robot-assisted cystectomy. (United States)

    Loertzer, P; Siemer, S; Stöckle, M; Ohlmann, C H


    To analyze the feasibility and perioperative results of patients undergoing robot-assisted cystectomy with intracorporeal urinary diversion and robot-sewn ileoileal anastomosis. This is a mono-centric analysis of perioperative data from 48 consecutive patients undergoing robot-assisted cystectomy with intracorporeal urinary diversion and robot-sewn ileoileal anastomosis. Data include the preoperative variables, operative and postoperative course and complication rates related to bowel anastomosis. End points were time spent for anastomosis and intra- and postoperative complication rates. Median operating time was 23.0 (13-60) min for the ileoileal anastomosis. Median overall operating time was 295 (200-780) min, with a median of 282 (200-418) min and 414.0 (225-780) min for the ileum conduit (N = 35) and ileal neobladder (N = 13). Two patients developed paralytic ileus; in another patient acute peritonitis occurred, but was caused by urinary leakage and therefore unrelated to the bowel anastomosis. No anastomotic leakage was noticed. Costs for the robot-sewn anastomosis was 8€ compared to 1250€ for a stapled anastomosis which was performed in previous cases. Limitations are the non-comparative nature of the analysis and the limited number of patients. Robot-sewn ileoileal anastomosis is feasible with low complication rates. Compared to the stapled anastomosis, a robot-sewn ileoileal anastomosis may serve as an alternative and cost-saving approach.

  4. The importance of the apposition of the submucosal intestinal layers for primary wound healing of intestinal anastomosis. (United States)

    Jansen, A; Becker, A E; Brummelkamp, W H; Keeman, J N; Klopper, P J


    This study was undertaken to examine the importance of the apposition of the submucosal layers in healing of the intestinal anastomosis. On 18 mongrel dogs, weighing between 8 and 15 kilograms, four anastomoses were performed on the small intestine. Two with a conventional anastomosis and two with rings of polyester-polyethyleneterephtalate, containing small Ticonal magnets. The force between the rings with the magnets varied from 0-3 newton between, respectively, 15 millimeters and zero millimeter distance. After three to four days, the rings cut through and disappeared from the anastomosis. Morphologic and microangiographic studies, undertaken at ten days, revealed that, in instances of good submucosal apposition, direct bridging of the defect in the submucosal layer was seen with rapid restoration of the villous epithelium and an undisturbed vascular pattern in the anastomotic area. This we called primary intestinal healing. In instances of bad submucosal apposition, we saw indirect bridging of the submucosal layer defect by smaller and longer strands of newly synthesized collagen tissue in the outer intestinal layers with a collateral circulation from the submucosal plexus to the arterial plexuses in these layers. In all instances, an epithelial defect still persisted at ten days. This type of wound healing we called secondary intestinal healing. The results showed that, with the magnetic rings, a significantly better apposition of the intestinal layers was achieved.

  5. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas


    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  6. Billroth I anastomosis using a circular stapler for corrosive gastric ...

    African Journals Online (AJOL)

    Introduction: Resection and hand-sewn Billroth I reconstruction is the commonly carried out procedure for type I gastric strictures. The use of staplers for Billroth I anastomosis is limited. Here we describe a unique technique of Billroth I anastomosis using a circular stapler without a gastrotomy in a case of corrosive gastric ...

  7. Systematic review of the technique of colorectal anastomosis

    NARCIS (Netherlands)

    J.C. Slieker (Juliette); F. Daams (Freek); I.M. Mulder (Irene); J. Jeekel (Hans); J.F. Lange (Johan)


    textabstractMany different techniques of colorectal anastomosis have been described in search of the technique with the lowest incidence of anastomotic leak. A systematic review of leak rates of techniques of hand-sewn colorectal anastomosis was conducted to provide a guideline for surgical

  8. Simultaneous Periprosthetic Acetabular Fracture and Contralateral B-Type Compression Injury of the Pelvic Ring: A Case Report of a Rare Injury Combination

    Directory of Open Access Journals (Sweden)

    Sven Märdian


    Full Text Available The periprosthetic fracture of the acetabulum is a rare injury, and its management is only sporadically reported in the literature. A few case reports are available which mainly focus on periprosthetic acetabular fractures in the elderly population. In our case, a 32-year-old patient suffered from a periprosthetic acetabular fracture in combination with a pelvic ring injury following a high velocity accident. The fracture morphology allowed a salvage of the prosthesis with an open reduction and internal fixation with a good radiographic and functional outcome one year after trauma.

  9. Measuring Gaps In O-Ring Seals (United States)

    Johnson, Scott E.


    Technique enables measurement of leakage areas created by small obstructions in O-ring seals. With simple fixture, gaps measured directly. Compresses piece of O-ring by amount determined by spacers. Camera aimed through clear plastic top plate records depression made in O-ring by obstruction. Faster, easier, more accurate than conventional estimation.

  10. Replantation of ring avulsion amputations

    Directory of Open Access Journals (Sweden)

    Sabapathy R


    Full Text Available Replantation of ring avulsion injuries is a challenge because of the long segment damage to the vessels and intrinsic damage caused to soft tissues at the proximal edge of the amputation. Eight patients with total ring avulsion amputations underwent microsurgical replantation in the period 1994 to 2002. Arterial repair was done by direct vessel suture in three patients, interposition vein grafts in two and cross anastomosis of the digital arteries in three patients. Venous anastomosis was carried out by mobilization and direct suture in seven patients and vessel transfer from the adjacent finger in one patient. Seven of the eight replantations were successful, while one patient had a partial failure. At a minimum follow-up of one year, these patients showed good functional and cosmetic recovery. All successful patients were happy with the outcome and none have requested for amputation, even those whose results were not functionally adequate. However, in addition to technical factors, it is important to evaluate the patient's motivation to undergo not only the long surgery, but also multiple secondary procedures and regular supervised physiotherapy. We also describe a simple method which prevents the soft tissues inside the degloved digit from becoming wrapped around the K wire during bony fixation, thus making one step of this technically challenging procedure a little easier.

  11. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)


    White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

  12. Simple model for training in the laparoscopic vesicourethral running anastomosis. (United States)

    Nadu, Andrei; Olsson, Lief Eric; Abbou, Claude Clement


    To create a simple model for training in the complex technique of laparoscopic vesicourethral anastomosis after radical prostatectomy. A model simulating the performance of a laparoscopic running urethrovesical anastomosis was fashioned using skin of a supermarket chicken set in a laparoscopic training box. A circular continuous anastomosis was performed, following exactly the technique we use in vivo for performing a vesicourethral anastomosis after laparoscopic radical prostatectomy. Details regarding the use of the right or the left needle holder, needle positioning, precise stitch position, and use of forehand or backhand stitch were strictly respected in order to reproduce the continuous stitch currently done in vivo in our department. The learning curve was analyzed in terms of the time necessary to perform the task and the quality of the anastomosis. The model was created and used by the junior authors during their year of fellowship in advanced laparoscopic urology. The authors had no previous experience with hands-on laparoscopic suturing but have assisted in a great number of laparoscopic radical prostatectomies. The time required for performing the anastomosis on the model declined from 75 minutes initially to 20 minutes after the trainees had performed 20 anastomoses each. After this training, it was possible to create a watertight running laparoscopic vesicourethral anastomosis in patients in a mean time of 40 minutes (range 30-55 minutes). This simple model allows the trainee in laparoscopic urology to acquire the skills necessary to perform a laparoscopic vesicourethral anastomosis, one of the most complex steps in laparoscopic radical prostatectomy, as well as to develop dexterity and facility in laparoscopic manipulation of needles, sutures, and fragile tissues.

  13. [Hemi-hypoglossal-facial intratemporal side to side anastomosis]. (United States)

    Lassaletta, Luis; González, Teresa; Casas, Pablo; Roda, José María; Moraleda, Susana; Gavilán, Javier


    Conventional hypoglossal-facial anastomosis and the interposition jump graft variation are the most popular techniques for facial nerve reconstruction resulting from proximal facial nerve injury. We present a modification of this technique, the hemi-hypoglossal facial intratemporal side to side anastomosis, which overcomes many of the failings of previous techniques. The method involves mobilization of the intratemporal facial nerve, which is anastomosed to a partially incised hypoglossal nerve. It is especially indicated in patients with multiple cranial nerve palsies.

  14. Neptune's rings (United States)


    This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  15. Is hand-sewn anastomosis superior to stapled anastomosis following oesophagectomy? (United States)

    Kayani, Babar; Garas, George; Arshad, Mubarik; Athanasiou, Thanos; Darzi, Ara; Zacharakis, Emmanouil


    A best evidence topic was written according to a structured protocol. The question addressed was: In patients undergoing oesophagectomy is stapled anastomosis (STA) superior to hand-sewn anastomosis (HSA) with respect to post-operative outcomes. In total, 82 papers were found suitable using the reported search and 14 of these represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. Existing evidence shows that STA is associated with reduced time to anastomotic construction and decreased intra-operative blood loss but increased risk of benign stricture formation compared to HSA. There is no difference between HSA and STA with respect to cardiac or respiratory complications, anastomotic leakage, duration of hospital admission or 30-day mortality. In HSA, increasing surgical experience and intra-operative air leakage testing after anastomotic creation are associated with reduced risk of anastomotic leakage. Further adequately powered studies will enable identification of other local and systemic factors influencing anastomotic healing, which will lead to improved patient and anastomotic technique selection for optimal surgical outcomes. Copyright © 2013. Published by Elsevier Ltd.

  16. Ring theory

    CERN Document Server

    Rowen, Louis H


    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  17. Supermicrosurgical deep lymphatic vessel-to-venous anastomosis for a breast cancer-related arm lymphedema with severe sclerosis of superficial lymphatic vessels. (United States)

    Yamamoto, Takumi; Yamamoto, Nana; Hayashi, Akitatsu; Koshima, Isao


    Lymphatic supermicrosurgery or supermicrosurgical lymphaticovenular anastomosis (LVA) is becoming popular for the treatment of compression-refractory upper extremity lymphedema (UEL) with its effectiveness and minimally invasiveness. In conventional LVA, superficial lymphatic vessels are used for anastomosis, but its treatment efficacy would be minimum when superficial lymphatic vessels are severely sclerotic. Theoretically, deep lymphatic vessels can be used for LVA, but no clinical case has been reported regarding deep lymphatic vessel-to-venous anastomosis (D-LVA). We report a breast cancer-related UEL case treated with D-LVA, in which a less-sclerotic deep lymphatic vessel was useful for anastomosis but superficial lymphatic vessels were not due to severe sclerosis. A 62-year-old female suffered from an 18-year history of compression-refractory right UEL after right breast cancer treatments, and underwent LVA under local infiltration anesthesia. Because superficial lymphatic vessels found in surgical fields were all severely sclerotic, a deep lymphatic vessel was dissected at the cubital fossa. A 0.50-mm deep lymphatic vessel running along the brachial artery was supermicrosurgically anastomosed to a nearby 0.40-mm vein. At postoperative 12 months, her right UEL index decreased from 134 to 118, and she could reduce compression frequency from every day to 1-2 days per week to maintain the reduced lymphedematous volume. D-LVA may be a useful option for the treatment of compression-refractory UEL, when superficial lymphatic vessels are severely sclerotic. © 2015 Wiley Periodicals, Inc. Microsurgery 37:156-159, 2017. © 2015 Wiley Periodicals, Inc.

  18. Effect of omentum graft on esophageal anastomosis in dogs

    Directory of Open Access Journals (Sweden)

    A. K. Mahdi


    Full Text Available The aim of this study was to evaluate the complications and final function outcome of wrapping nonvascularized omentum graft around the suture line of esophageal anastomosis. Twelve adult local breed dogs were used in this study. The animals were divided into two equal groups (control and treated, all animal induced into general anesthesia by injection of atropen sulphate in a dose 0.04 mg/kg B.W, intramuscularly then after 15 minute given mixture of ketamine hydrochloride and xylazine hydrochloride in doses 15 mg/kg and 5 mg/kg B.W intramuscularly respectively. An oblique resection of about 1cm of the esophageal length and anastomosis by double layer of simple interrupted pattern by 2.0 cat gut suture (control group, same procedure was done in treated group except the wrapping the anastomosis site with patch of omentum tissue after lapratomy operation in the left flank region procedure. The clinical signs of treated animal revealed signs of dysphagia and regurgitation in treated group while this signs disappear in the control group. Radiological and histopathological examination of the anastomosis site performed at 15 and 30 days post operation. Radiological study recorded high degree of stenosis in the anastomosis site in treated group at 15 and 30 days post operation in compared with animals in control group that record mean degree of stenosis in treated group at 15 day (57.61±0.2 and at 30 day (55.78±0.2 while it recorded in control group at 15 day (39.34±1.04 and at 30 day (36.0.6 ±0.9, histopathological results recorded enhanced healing of anastomosis site in treated animals more than control animals. In conclusion we found that non vascularized omental graft prevent leak when used around the anastomosis line in esophageal and enhanced healing of anastomosis line but it increase the stenosis, fibrosis and adhesion of anastomosis site with surrounding muscle and this interferes with the swallowing as well as dysphagia and regurgitation

  19. Long-term functional results of radiation after coloanal anastomosis

    Directory of Open Access Journals (Sweden)

    CAC Mathias


    Full Text Available Surgery is the only treatment that can cure most patients with colorectal cancer. Radiation therapy (pre or postoperative has been shown to improve results by decreasing local recurrence and improving survival. Our aim was to analyze whether postoperative radiation influenced long-term functional outcomes and the probability of stricture of anastomosis in patients who underwent coloanal anastomosis for rectal cancer. Methods: The records of 84 patients with coloanal anastomosis for rectal cancer were studied between 1980 and 1996. There were 82 males and 28 females. Mean age was 57.8 years (range 24 to 78 years. Mean distal resection margin was 2.6 cm (range 0 to 14cm. Twenty-three patients received postoperative irradiation therapy. Patients who received chemotherapy were not included in the study. Results were analysed by examination , telephone or questionnaire. Mean follow-up was 3.8 years (range 0 to 13 years. Results: There was no operative mortality. Functional variables were much better in non-irradiated patients. The irradiated group had more number of stools/day (p>0.05, more number of stools/ night (p>0.05, more incontinence/day (p0.05. Conclusion: Postoperative irradiation after colo-anal anastomosis for rectal cancer is safe, but may increase the risk of stricture of anastomosis and does affect functional results adversely.

  20. [Hypoglossofacial anastomosis for facial palsy treatment: Indications and results]. (United States)

    Lamas, G; Gatignol, P; Barbut, J; Bernat, I; Tankéré, F


    Hypoglossofacial anastomosis is a classical surgical procedure for the treatment of facial paralysis when the trunk of the facial nerve cannot be repaired and its peripheral branches are normal. Between 2004 and 2015, 77 patients were able to benefit from an hypoglossofacial anastomosis. The etiology of the paralysis was mainly the surgery of vestibular schwannoma, tumors of the facial nerve and diseases of the brainstem. A specific and premature speech therapy remediation was realized for all patients in order to preserve the tongue function and to upgrade the facial motricity. Sixty-nine patients could be studied. The House Brackmann grading scale was used to appreciate the result. Thirty-one patients are grade III, 34 grade IV and in only one case the result is a grade V despite the anastomosis works. The main predictive factor for a good result is a small delay between the onset of the paralysis and the surgery for the rehabilitation. The specific physiotherapy upgrades the result with less side effects of the anastomosis. Hypoglossofacial anastomosis is a simple and reliable surgical procedure for rehabilitation of paralysed face. The quality of the result is linked with an early surgery and a specific physiotherapy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. Rupture of vesicourethral anastomosis following radical retropubic prostatectomy

    Directory of Open Access Journals (Sweden)

    Marcos Dall'oglio


    Full Text Available OBJECTIVE: Rupture of vesicourethral anastomosis following radical retropubic prostatectomy is a complication that requires immediate management. We evaluated the morbidity of this rare complication. MATERIALS AND METHODS: We analyzed retrospectively 5 cases of disruption of vesicourethral anastomosis during post-operative period in a consecutive series of 1,600 radical retropubic prostatectomies, performed by a single surgeon. RESULTS: It occurred in a ratio of 1:320 prostatectomies (0,3%. Management was conservative in all the cases with an average catheter permanence time of 28 days, being its removal preceded by cystography. Two cases were secondary to bleeding, 1 followed the change of vesical catheter and 2 by unknown causes after removing the Foley catheter. Only one patient evolved with urethral stenosis, in the period ranging from 6 to 120 months. CONCLUSION: Rupture of vesicourethral anastomosis is not related to the surgeon's experience, and conservative treatment has shown to be effective.

  2. Diabetes resolution after one anastomosis gastric bypass. (United States)

    Abu-Abeid, Adam; Lessing, Yonatan; Pencovich, Niv; Dayan, Danit; Klausner, Joseph M; Abu-Abeid, Subhi


    Diabetes and other obesity-related diseases are a worldwide pandemic that transcends geographic borders as well as socioeconomic levels. Currently, it is well known that medical treatment alone is insufficient to ensure adequate and sustainable weight loss and co-morbidity resolution. It has been well proven that bariatric surgery can produce almost immediate resolution of diabetes and other co-morbidities as well as long-term weight loss. Here, we present our experience with the one anastomosis gastric bypass (OAGB) in terms of weight loss and diabetes resolution with 1 year of follow-up. Large, metropolitan, tertiary, university hospital. A retrospective analysis of all patients who underwent OAGB between March 2015 and March 2016 was performed. Patient demographic characteristics, co-morbidities, operative and postoperative data, as well as first year outcomes were collected and analyzed. There were 407 patients who underwent OAGB (254 females, average age 41.8 ± 12.05 yr, body mass index = 41.7 ± 5.77 kg/m 2 ). Of patients, 102 (25.1%) had diabetes with average glycosylated hemoglobin of 8.64 ± 1.94 g%, 93 (22.8%) had hypertension, 123 (28.8%) had hyperlipidemia, and 35 patients (8.6%) had obstructive sleep apnea. The average length of hospital stay was 2.2 ± .84 days (range, 2-10 d). The average excess weight loss 1 year after surgery was 88.9 ± 27.3. After 1 year, follow-up data were available for more than 85% of the study's general population. Of 102 diabetic patients, only 8 (7.8%) were still considered diabetic and taking antidiabetic medication, with an average glycosylated hemoglobin of 5.4 ± 0.6. OAGB may be performed safely and with promising efficacy as both a primary and a revisional bariatric surgery, and it offers excellent resolution of diabetes. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  3. [Prevention of the anastomosis dehiscence following low anterior rectal resections]. (United States)

    Hut'an, M; Lukác, I; Poticný, V


    Authors analyse 106 patients that were operated in their department by Dixon's method, in retrospective study. They analyse indications for operations, lesions distance in rectum, endosonographic and CT findings. Basic principles of the operation technique are adequate blood flow, sufficient colon mobilization and tightness of the anastomosis being supplemented with transanal pertubation. Out of early complications anastomosis dehiscence appeared in 6 patients (e.g. 5.6%) out of which 4 were treated conservatively and 2 were being reoperated on (by axial ileostomia and drainage). In discussion different opinions on preoperative preparation, neoadjuvant therapy, presacral drainage, transanal pertubation and other decompressive techniques are anticipated.

  4. Double-O-Ring Plug For Leak Tests (United States)

    Greene, James H.


    Pressure plug features redundant O-ring bore seals and axial port opening laterally into space between O-rings to enable testing of seals. Axial passage in plug connected through radial passage to space between O-rings. Opening used to test O-rings, then sealed with smaller O-ring compressed by machine screw. Useful to seal test or cleanout holes normally kept closed in hydraulic actuators, pumps, and other pressurized systems.

  5. Anastomosis grouping and genetic diversity analysis of Rhizoctonia ...

    African Journals Online (AJOL)

    Rhizoctonia solani is considered as one of the most destructive soil-and-seed borne plant pathogens infecting various agricultural crops including chickpea. The 50 chickpea isolates of R. solani representing 10 different states of India were variable in hyphal anastomosis reactions and they were grouped into seven AGs as ...

  6. New method of hand anastomosis to complete the Duhamel ...

    African Journals Online (AJOL)

    Objective/Purpose: This paper describes a new method of hand anastomosis to complete the Duhamel operation for Hirschsprung\\'s disease (HD). Methodology: All patients had diagnosis of Hirschsrung\\'s disease confirmed by rectal biopsy and had defunctioning colostomy. At the definitive operation, the ganglionic bowel ...

  7. The effect of extracoporeal schock waves on intestinal anastomosis

    African Journals Online (AJOL)


    Background and Objectives: To investigate the effect of extracorporeal shock waves on the healing of intestinal anastomosis. Materials and Methods: Thirty Wistar rats were randomly divided into three groups of ten each comprising of Group I. (only laparotomy), Group II (right colon segment resection and end to end ...

  8. OCT-aided anastomosis platform study in the rodent model (United States)

    Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.


    Anastomosis is one of the most commonly performed procedure in the clinical environment that involves tubular structures, such as blood vessel, lymphatic vessel, seminal duct and ureter. Suture based anastomosis is still the foundation for most basic surgical training and clinical operation, although alternate techniques have been developed and under development. For those tubular-structure-anastomosis, immediate real-time post-operative evaluation of the surgical outcome is critical to the success of surgery. Previously evaluation is mostly based on surgeons' experience. Fourier-domain optical coherence tomography is high-speed, high-resolution noninvasive 3D imaging modality that has been widely used in the biomedical research and clinical study. In this study we used Fourier-domain optical coherence tomography as an evaluation tool for anastomosis of lymphatic vessels, ureter and seminal duct in rodent model. Immediate post-operative and long term surgical site data were collected and analyzed. Critical clinical parameters such as lumen patency, anastomosed site narrowing and suture error detection are provided to surgeons.

  9. Safe Resection and Primary Anastomosis of Gangrenous Sigmoid ...

    African Journals Online (AJOL)

    Introduction The management of sigmoid volvulus has remained a controversial issue to many surgeons. Rapid resection with colostomy fashioning has been done over time for gangrenous sigmoid volvulus. However, resection and primary anastomosis has also been described with less complications and a shorter ...

  10. Surgery for necrotising enterocolitis : primary anastomosis or enterostomy?

    NARCIS (Netherlands)

    Hofman, FN; Bax, NMA; van der Zee, DC

    The ideal surgical management of neonates with necrotising enterocolitis (NEC) is still a matter of debate. The purpose of this study was to compare the results of bowel resection with primary anastomosis with the results of bowel resection with enterostomy. Sixty-three neonates with NEC had a bowel

  11. Anastomosis Procedure through an Inguinal Hernia Incision in ...

    African Journals Online (AJOL)

    For laparoscopic anterior resection, an additional small incision is usually placed in the left lower quadrant or the suprapubic portion. As a left inguinal hernia incision is close to both the left lower quadrant and the suprapubic portion, such an incision can be used for anastomosis in laparoscopic anterior resection, without ...

  12. Rehabilitation of central facial paralysis with hypoglossal-facial anastomosis. (United States)

    Corrales, C Eduardo; Gurgel, Richard K; Jackler, Robert K


    To evaluate the ability of hypoglossal-facial nerve anastomosis to reanimate the face in patients with complete nuclear (central) facial nerve palsy. Retrospective case series. Tertiary academic medical center. Four patients with complete facial nerve paralysis due to lesions of the facial nucleus in the pons caused by hemorrhage due to arteriovenous or cavernous venous malformations, stroke, or injury after tumor resection. All patients underwent end-to-end hypoglossal-facial nerve anastomosis. Facial nerve function using the House-Brackmann (HB) scale and physical and social/well-being function using the facial disability index. The mean age of the patients was 53.3 years (range, 32-73). There were 3 female and 1 male patients. All patients had preoperative facial function HB VI/VI. With a minimum of 12 months' follow-up after end-to-end hypoglossal-facial anastomosis, 75% of patients regained function to HB grade III/VI, and 25% had HB grade IV/VI. Average facial disability index scores were 61.25 for physical function and 78 for social/well-being, comparable to results from complete hypoglossal-facial anastomosis after peripheral facial nerve palsy after acoustic neuroma resection. Patients with nuclear facial paralysis who undergo end-to-end hypoglossal-facial nerve anastomosis achieve similar degrees of reanimation compared with those with peripheral facial nerve palsies. This raises the intriguing possibility that reinnervation may also be of benefit in patients with the vastly more common facial dysfunction because of cortical stroke or injury.

  13. Common Anastomosis and Internal Transcribed Spacer RFLP Groupings in Binucleate Rhizoctonia Isolates Representing Root Endophytes of Pinus sylvestris, Ceratorhiza spp. from Orchid Mycorrhizas and a Phytopathogenic Anastomosis Group

    National Research Council Canada - National Science Library

    Robin Sen; Ari M. Hietala; Carla D. Zelmer


    ...) seedlings and the orchid Goodyera repens from Scots pine forests were characterized on the basis of morphological characters, anastomosis group membership and PCR-assisted ribosomal DNA fingerprinting...

  14. Vascular ring

    DEFF Research Database (Denmark)

    Schmidt, Anne Mette S; Larsen, Signe H; Hjortdal, Vibeke E


    BACKGROUND: Vascular ring is a rare cause of recurrent respiratory infections, dysphagia and stridor. Surgical repair is considered safe but the long-term outcomes are unclear. The purpose of this study was to investigate the mortality and morbidity following vascular ring surgery in a single...... age of 1.4 years (range 0.008-64 years) were operated for vascular ring. Median follow-up was 6.8 years (range 2.4-34 years). Presenting symptoms were stridor (52%), dysphagia or vomiting (52%) and recurrent respiratory infections (48%). There were no early or late deaths. Three months postoperatively...

  15. Determinantal rings

    CERN Document Server

    Bruns, Winfried


    Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a ...

  16. Cardiovascular anatomy in children with bidirectional Glenn anastomosis, regarding the transcatheter Fontan completion. (United States)

    Sizarov, Aleksander; Raimondi, Francesca; Bonnet, Damien; Boudjemline, Younes


    Transcatheter stent-secured completion of total cavopulmonary connection (TCPC) after surgical preparations during the Glenn anastomosis procedure has been reported, but complications from this approach have precluded its clinical acceptance. To analyse cardiovascular morphology and dimensions in children with bidirectional Glenn anastomosis, regarding the optimal device design for transcatheter Fontan completion without special surgical "preconditionings". We retrospectively analysed 60 thoracic computed tomography and magnetic resonance angiograms performed in patients with a median age of 4.1 years (range: 1.8-17.1 years). Additionally, we simulated TCPC completion using different intra-atrial stent-grafts in a three-dimensional model of the representative anatomy, and performed calculations to determine the optimal stent-graft dimensions, using measured distances. Two types of cardiovascular arrangement were identified: left atrium interposing between the right pulmonary artery (RPA) and inferior vena cava, with the right upper pulmonary vein (RUPV) orifice close to the intercaval axis (65%); and intercaval axis traversing only the right(-sided) atrial cavity, with the RUPV located posterior to the atrial wall (35%). In the total population, the shortest median RPA-to-atrial wall distance was 1.9mm (range: 0.6-13.8mm), while the mean intra-atrial distance along the intercaval axis was 50.1±11.2mm. Regardless of the arrangement, 83% of all patients required a deviation of at least 5.9±2.4mm (range: 1.2-12.7mm) of the stent-graft centre at the RUPV level anteriorly to the intercaval axis to avoid covering or compressing this vein. Fixing the anterior deviation of the curved stent-graft centre at 10mm significantly decreased the range of bend angle per every given RUPV-RPA distance. For both types of cardiovascular arrangement, after conventional bidirectional Glenn anastomosis, the intra-atrial curved stent-graft seemed most suitable for achieving

  17. JPEG ringing artifact visibility evaluation (United States)

    Hu, Sirui; Pizlo, Zygmunt; Allebach, Jan P.


    To achieve high perceptual quality of compressed images, many objective image quality metrics for compression artifacts evaluation and reduction have been developed based on characterization of local image features. However, it is the end user who is judging the image quality in various applications, so the validation of how well these metrics predict human perception is important and necessary. In this paper, we present a preliminary psychophysics experiment method to capture human perception of local ringing artifacts in JPEG images with different severity levels. Observers are asked to annotate the compressed image where they perceive artifacts along the edges, directly on the screen using an interactive tablet display. They are asked to catalog the severity of artifacts into one of the three levels: Strong, Medium, and Light. We process the hand-marked data into a ringing visibility edge map showing a ringing severity mean opinion score (MOS) at every edge pixel. The perceptual information captured in this experiment, enables us to study the correlation between human perception and local image features, which is an important step towards the goal of developing a non-reference (NR) objective metric to predict the visibility of JPEG ringing artifacts in alignment with the assessments of human observers.

  18. Estudo comparativo entre anastomoses intestinais com sutura manual e com anel biofragmentável em cães sob a administração de corticosteróides Comparative study of intestinal anastomoses with manual suture and biofragmentable ring in dogs under corticosteroid administration

    Directory of Open Access Journals (Sweden)

    L. C. Fernandes


    of hydrocortisone hemisuccinate, 25 to 33 mg/kg/day, on the 30th preoperative and 7th postoperative days. During surgery, each animal underwent two colon sections with anastomosis by manual suture in a single extramucous plane and compression with biofragmentable ring. The animals were sacrificed 7 days after the procedure to evaluate the anastomoses. RESULTS: In the postoperative period, one death occurred in the test group and two in the control group, caused by nonblocked fistula in the anastomoses by ring compression. Statistically, there was a similar incidence of adherences, fistulas, afferent dilatation and obstruction using comparison methods. On microscopy, deficiency in mucous regeneration of the anastomoses by compression was observed. Computerized histological analysis evidenced in the anastomoses by compression, a greater inflammatory reaction, greater edema of the submucous membrane and enlarged scars. CONCLUSIONS: It was concluded that, with the biofragmentable ring, in colonic anastomosis under delay of cicatrization induced by corticoids, similar results to manual suture regarding to postoperative complications incidence were obtained; ring, however, determined worse mucous regeneration and greater cicatricial inflammatory reaction.

  19. Left-sided colectomy with retroileal colorectal anastomosis. (United States)

    Rombeau, J L; Collins, J P; Turnbull, R B


    Following resection of the sigmoid and descending colon for cancer or extensive diverticular disease, it may be impossible to make a colorectal anastomosis due to inadequate length of the residual transverse colon. To correct this problem, the remaining transverse colon may be pulled into the pelvis by making a "window" in the terminal part of the ileal mesentery. From January 1966 to January 1975, 302 resections of the descending colon with colorectal anastomoses were performed by one of the authors (R.B.T.) for upper sigmoid cancer and extensive diverticulitis at the Cleveland Clinic. Eleven patients (4%) had retroileal colorectal anastomoses. The retroileal apprach is a technical aid when performing an extensive left-sided colectomy and/or when there is insufficient length of residual transverse colon to make a tension-free colorectal anastomosis.

  20. Evaluation healing of jejunal anastomosis in preoperative dexamethasone treated dogs

    Directory of Open Access Journals (Sweden)

    A.S. Al-Qadhi


    Full Text Available The objective of this study is to evaluate the healing process of jejunal anastomosis by the aid of histopathology and measurement of bursting pressure of anastomosis site in thirty two adult preoperatively with dexamethasone. The animals were randomly divided into 2 equal groups: Group 1: consists of 16 dogs underwent apposition end-to-end jejunal anastomosis using simple interrupted suture technique which in turn divided into 2 subgroups: subgroup A: consists of 8 dogs treated preoperatively for 15 days with dexamethasone at a dose of (0.2mg/kg given I/M. Subgroup B: control group consists of 8 dogs not treated with dexamethasone. Group 2: consists of 16 dogs underwent inverted end-to-end jejunal anastomosis using continuous Lembert suture pattern that also divided into 2 subgroups: subgroup A: consists of 8 dogs treated preoperatively for 15 days with dexamethasone at a dose of (0.2mg/kg given I/M. subgroup B: control group consists of 8 dogs not treated with dexamethasone. The result of bursting pressure measurement showed higher tensile strength in the control groups (445±9.6 in comparison with the steroidal groups (255±25.3 for both techniques. The histopathological study showed that the healing was good in all groups but the rupture that occur due to shedding the pressure lead to non discrimination between which is better in terms of healing. Massonʼs trichrome showed that collagen content of subgroups taking dexamethasone was lower than that of subgroups not treated with dexamethasone.


    Directory of Open Access Journals (Sweden)

    T. I. Shraer


    Full Text Available We studied the outcomes of the operations for distal splenorenal venous anastomosis of 134 patients with type 1 diabetes mellitus. We have noticed the significant improvement of patient’s general condition due to spasmolytic effect of glucagon, bypassed to blood circulation without coming through liver and also a stabilization of glyce- mia because of a restoration of insulin-glucagon ratio in systemic circulation. The effect of a surgery depends on a stage of microangiopathy and nephrosclerosis. 

  2. Vesicopreputial anastomosis for the treatment of obstructive urolithiasis in goats. (United States)

    Cypher, Elizabeth Erin; van Amstel, Sarel R; Videla, Ricardo; Force Clark, Kyle; Anderson, David E


    To describe a novel surgical technique for the correction of recurrent obstructive urolithiasis in male goats. Clinical case series. Castrated male goats (n = 4). Medical records of male goats having undergone vesicopreputial anastomosis (VPA) as a treatment for obstructive urolithiasis were reviewed for history, signalment, clinical signs, and intraoperative and postoperative complications. Long-term follow-up (≥12 months) was obtained by telephone interview with owners or by clinical examination. All goats had undergone at least one surgical procedure (median, 2.5, range 2-4) to correct obstructive urolithiasis before undergoing VPA. Postoperative complications included premature removal of the tube from the bladder (1 goat), bacterial cystitis (2), and abscess formation (1). One goat suffered stricture of the anastomosis site 3 months following the original procedure and underwent a second VPA and 1 goat died 7 months after surgery due to severe, acute hydronephrosis and renal failure. Long-term survival ≥12 months was good with 3/4 goats (75%) or 3/5 VPA procedures (60%) having unobstructed urine flow at 12 months. Vesicopreputial anastomosis is a feasible surgical procedure for the correction of recurrent obstructive urolithiasis in male goats and one that can result in a favorable clinical outcome. Further investigation in a larger population of goats is warranted for the evaluation of the suitability of VPA in male goats with obstructive urolithiasis. © 2017 The American College of Veterinary Surgeons.

  3. Trichobezoar obstruction after stapled jejunal anastomosis in a dog. (United States)

    Carobbi, Barbara; Foale, Robert D; White, Richard A S


    To describe an unusual long-term complication of circular end-to-end anastomosis (CEEA) stapling in a dog. Clinical case report. An 11-year-old, female neutered, Labrador Retriever. The dog was referred for clinical signs of bowel obstruction. An enterectomy was performed 2 years before presentation using a CEEA stapling device. Palpation, plain radiographs, and ultrasound of the abdomen confirmed the presence of a mass in the bowel, causing obstruction, and requiring surgical approach. An exploratory celiotomy revealed a 5 cm mass in the jejunum, involving the site of the previous surgery. The mass was removed by enterectomy. Dissection of the mass revealed the presence of many staples at the previous enterectomy site, and a trichobezoar entangled in the exposed parts of the staples. An enterectomy was required to treat an intestinal obstruction caused by a trichobezoar entangled in a CEEA-stapled anastomosis. Development of trichobezoar and subsequent bowel obstruction should be considered an unusual but potential long-term complication of CEEA-stapled anastomosis.

  4. Comparison of postoperative motility in hand-sewn end-to-end anastomosis and functional end-to-end anastomosis: an experimental study in conscious dogs. (United States)

    Toyomasu, Yoshitaka; Mochiki, Erito; Ando, Hiroyuki; Yanai, Mitsuhiro; Ogata, Kyoichi; Tabe, Yuichi; Ohno, Tetsuro; Aihara, Ryuusuke; Kuwano, Hiroyuki


    The objective of this study is to compare the postoperative motility between hand-sewn end-to-end anastomosis and functional end-to-end anastomosis. Fifteen conscious dogs were divided into three groups: normal intact dog group, end-to-end anastomosis group (EE), and functional end-to-end anastomosis group (FEE). In the EE and FEE groups, the dogs underwent a transection of the jejunum 30 cm distal to the Treitz ligament and anastomosis in each method. To compare the gastrointestinal motility, the time to the appearance and the rate of propagation of interdigestive migrating motor contractions (IMC) across the anastomosis, as well as the motility index (MI) at the oral and anal sides of the anastomosis, were measured using strain gauge force transducers. Furthermore, the histological examination of intrinsic nerve fibers was evaluated. The time to the appearance of propagation of IMC in the EE and FEE was not significantly different. The propagation rates of IMC in the EE and FEE completely recovered within 4 weeks of the surgery. The MI in the EE and FEE was not significantly different. In addition, no continuity of intrinsic nerve fibers across the anastomosis could be identified in either group. In the present study, there are no significant differences between the EE and FEE with regard to the time of the appearance and the rate of propagation of IMC. These results suggest that the effect of functional end-to-end anastomosis on postoperative motility is not different from that of hand-sewn end-to-end anastomosis.

  5. Topological rings

    CERN Document Server

    Warner, S


    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  6. Compression embedding (United States)

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.


    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique are disclosed. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%. 21 figs.

  7. Distal third rectal cancer: intersphincteric anterior resection with manual anastomosis using the techniques of Parks or Turnbull-Cutait. (United States)

    Biondo, Sebastiano; Trenti, Loris; Kreisler, Esther


    Rectal ultralow, intersphincteric anterior resection (RIE) can be used in selected cases with the intention of improving the quality of life of patients avoiding permanent colostomy. RIE is indicated for tumors that are located from 1-2 cm above the anorectal ring to the top of the internal anal sphincter without involvement of the pelvic floor, puborrectalis muscle or external anal sphincter. RIE aims to get a free distal margin tumour not less than 1cm. Correct preoperative staging and anatomical tumour location and relation with adjacent structures and organs is fundamental. Intestinal transit reconstruction can be performed manually with a coloanal anastomosis according with Parks and with a lateral ileostomy or, alternatively, by a two-stage coloanal anastomosis technique as Turnbull-Cutait avoiding the stoma protection. Postoperative morbidity and mortality and the rate of local recurrence and overall disease-free survival at 5 years after RIE are comparable to those observed in standard ultra low anterior resection. Postoperative functional alterations of the RIE can affect the quality of life of patients regardless of reconstructive technique. Published studies do not provide sufficient data to establish the most efficient reconstruction method in terms of functional outcomes. Copyright © 2014 Asociación Española de Cirujanos. Published by Elsevier Espana. All rights reserved.

  8. Stapled versus handsewn methods for colorectal anastomosis surgery. (United States)

    Neutzling, Cristiane B; Lustosa, Suzana A S; Proenca, Igor M; da Silva, Edina M K; Matos, Delcio


    Previous systematic reviews comparing stapled and handsewn colorectal anastomosis that are available in the medical literature have not shown either technique to be superior. An update of this systematic review was performed to find out if there are any data that properly answer this question. To compare the safety and effectiveness of stapled and handsewn colorectal anastomosis surgery. The following primary hypothesis was tested: the stapled technique is more effective because it decreases the level of complications. A computerized search was performed in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE according to the strategies of the Colorectal Cancer Group of The Cochrane Collaboration. There were no limits upon language, date or other criteria. A revised search strategy was performed for this updated version of the review May 2011. All randomised controlled trials (RCTs) in which stapled and handsewn colorectal anastomosis techniques were compared. Participants were adult patients undergoing elective colorectal anastomosis surgery. The interventions were endoluminal circular stapler and handsewn colorectal anastomosis surgery. Outcomes considered were a) mortality; b) overall anastomotic dehiscence; c) clinical anastomotic dehiscence; d) radiological anastomotic dehiscence; e) stricture; f) anastomotic haemorrhage; g) reoperation; h) wound infection; i) anastomosis duration; and j) hospital stay. Data were independently analysed by the two review authors (CBN, SASL) and cross-checked. The methodological quality of each trial was assessed by the same two authors. After searching the literature for this update, no study was added to those in the previous version of this review. Details of randomizations (generation and concealment), blinding, whether an intention-to-treat analysis was done or not, and the number of patients lost to follow-up were recorded. The analysis of the risk of bias was updated according to the software

  9. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei


    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  10. The preparation of anastomosis site at the insular segment of middle cerebral artery


    Katsuno, Makoto; Tanikawa, Rokuya; Izumi, Naoto; Hashimoto, Masaaki


    Background: An anastomosis at the insular segment of the middle cerebral artery (M2) is often required in cerebral reconstruction with high- or low-flow bypass. It is necessary to create a shallow, wide, fixed, and bloodless anastomosis field to achieve a safe and quick anastomosis for low surgical morbidity. We describe a method to perform a safe and quick anastomosis. Methods: From 2009 to 2013, the technique was used in 20 procedures to create an extracranial M2 high-flow bypass. The S...

  11. Reanastomosis with Stapler in Duodenojejunal Junction Anastomosis Leakage: A Case Report

    Directory of Open Access Journals (Sweden)

    Ahmet Seker


    Full Text Available After anastomosis leakages, treatment of patient gets more difficult and mortality rates increase. At lower level gastrointestinal anastomosis leakages, because of always there is an ostomy alternative, digestion problems are seen lesser. But at upper level gastrointestinal system anastomosis leakages, when it is taken account of nutrient condition of patient, requirement of making anastomos increases. So moratlity rates increase. At this article we aimed to present a different technique that we administered on management of a patient who had duodenojejunal junction anastomosis leakage.

  12. Anastomosis coronaria. Técnica quirúrgica. Endarterectomía coronaria


    Legarra, Juan José


    La técnica quirúrgica para la realización de las anastomosis coronarias engloba desde la propia estrategia preoperatoria de revascularización al hecho técnico quirúrgico de la anastomosis. Los pasos importantes a destacar son la localización de los lechos coronarios, la preparación de los mismos, la arteriotomía y la sutura del injerto o anastomosis. Es crucial la comprobación del resultado funcional de las anastomosis con un medidor de flujo coronario. Estos aspectos son comunes a la circula...


    Chai, Libing; Liu, Hongxia; Liu, Yuejiao; Lu, Laijin; Cui, Jianli


    To investigate the decompression and diverting effects of vascular anastomosis based on the digital arterial arch branch in replantation of free finger-pulp in distal phalanges. A retrospective analysis was performed on the clinical data of 12 patients (12 fingers) who underwent free finger-pulp replantation with anastomosis of proper palmar digital artery and the palmar digital artery arch branch in the distal end between December 2004 and March 2015. Of 12 cases, 9 were male and 3 were female, aged 15-39 years with an average of 32 years. The causes of injury included cutting injury in 4 cases, crush injury in 7 cases, and avulsion injury in 1 case. The thumb was involved in 2 cases, index finger in 4 cases, ring finger in 3 cases, middle finger in 1 case, and little finger in 2 cases. The free finger pulp ranged from 1.8 cm x 1.5 cm to 2.8 cmx2.0 cm. The time from injury to operation ranged from 1.5 to 11.0 hours, with an average of 5.7 hours. No arterial arch or proper palmar digital arteriae anastomosis was excluded. Free finger-pulp survived in 11 cases after operation; venous crisis occurred in 1 case at 2 days after operation, and was cured after symptomatic treatment. Nine cases were followed up 6-18 months with an average of 10 months. The finger-pulp had good appearance, clear fingerprint, and soft texture. The two-point discrimination was 3.1-6.0 mm, with an average of 4.6 mm at 6 months after operation. The function of finger flexion and extension was normal. And according to upper extremity functional evaluation standard by hand surgery branch of Chinese Medical Association, the results were excellent in 7 cases, and good in 2 cases. In the replantation of amputated pulp with insufficiency of venous blood outflow, the anastomosis of digital arterial arch branch in the distal end can decompress and shunt arterial blood, adjust blood inflow and outflow, and solve the problems of insufficient quantity of the vein and venous reflux disturbance.


    African Journals Online (AJOL)

    ); 0 “C1211; 30.13 ('BuP. o. J,.,_. = 12.2 1-11). @500 (OCH._,, dq,. J“. = 34.6. JR. = 15.8 H2). 124.39 (CF3. dq, JPF = 269.0, JR. = 9.7 Hz). 35.63 (PC. cl. .... The compound was prepared using the same technique from the boron ring [31 [2 g.

  15. Combined conservative treatment and lymphatic venous anastomosis for severe lower limb lymphedema with recurrent cellulitis. (United States)

    Mihara, Makoto; Hara, Hisako; Tsubaki, Hiromi; Suzuki, Takiko; Yamada, Naomi; Kawahara, Mari; Murai, Noriyuki


    Lymphedema may be treated either conservatively or surgically. Although conservative therapy is the first-line treatment, some patients are refractory to it and repeat severe cellulitis. We usually perform lymphaticovenous anastomosis (LVA) for lymphedema patients, and LVA can reduce the frequency of cellulitis. A 67-year-old woman who had undergone a radical hysterectomy, pelvic lymphadenectomy, and postoperative radiotherapy for cervical cancer at the age 50 years. She developed lymphedema in both legs, and high-pressure compression stockings caused lymphorrhea in the groin and thigh, resulting in recurrent episodes of cellulitis. Lymphoscintigraphy revealed dilation of the lymphatic vessels in both legs. Results of an indocyanine green test revealed dermal backflow throughout the lower body. After wearing low-pressure stocking, we performed LVA to reduce cellulitis. After confirming the result of LVA, the patients started wearing high-pressure stocking. The patient underwent a subsequent LVA, 3 months after the first, to further improve edema. The lymphorrhea resolved, and cellulitis did not recur. The combination of surgical treatment and conservative treatment is important for severe lymphedema treatment. Although conservative treatment is usually said to be the first-line treatment, LVA can antecede in cases refractory to conservative treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Relinkable Ring Signature (United States)

    Suzuki, Koutarou; Hoshino, Fumitaka; Kobayashi, Tetsutaro

    In this paper, we propose the concept of a relinkable ring signature, which is a ring signature with ring reformation function, i.e., a signer can delegate ring reformation ability separately from signing ability to his/her proxy. The relinkable ring signature can be applicable to proxy ring reformation, anonymization of past-generated signature, or ring signature for dynamic group. We also propose a concrete relinkable ring signature scheme that uses pairing in the random oracle model.

  17. The relationship between method of anastomosis and anastomotic failure after right hemicolectomy and ileo-caecal resection

    DEFF Research Database (Denmark)

    Laurberg, Søren


    BACKGROUND: Anastomosis technique following right sided colonic resection is widely variable and may affect patient outcomes. This study aimed to assess the association between leak and anastomosis technique (stapled versus handsewn) METHODS: This was a prospective, multicentre, international audit...

  18. Peri-operative care for patients undergoing lymphaticovenular anastomosis: A systematic review

    NARCIS (Netherlands)

    Winters, H.; Tielemans, H.J.P.; Sprangers, P.N.; Ulrich, D.J.O.


    BACKGROUND: Lymphaticovenular anastomosis (LVA) is a supermicrosurgical procedure that involves the anastomosis of a functional lymphatic channel to a venule. Although peri-operative care might be an important contributor to the success of this technique, evidence about optimal peri-operative care

  19. The efficacy of lymphaticovenular anastomosis in breast cancer-related lymphedema

    NARCIS (Netherlands)

    Winters, H.; Tielemans, H.J.P.; Hameeteman, M.; Paulus, V.A.A.; Beurskens, C.H.G.; Slater, N.J.; Ulrich, D.J.O.


    INTRODUCTION: Lymphedema can be a debilitating condition, causing a great decrease in a person's quality of life (QoL). Treatment with lymphaticovenular anastomosis (LVA), in which an anastomosis is created between the lymphatic and venous system, may attenuate lymphedema symptoms and reduce

  20. Abdominal aorta anastomosis in rats and stable gastric pentadecapeptide BPC 157, prophylaxis and therapy. (United States)

    Hrelec, M; Klicek, R; Brcic, L; Brcic, I; Cvjetko, I; Seiwerth, S; Sikiric, P


    We focused on abdominal aorta, clamped and transected bellow renal arteries, and aortic termino-terminal anastomosis created in Albino male rats. We suggested stomach cytoprotection theory holding endothelium protection and peptidergic anti-ulcer cytoprotection therapy to improve management of abdominal aorta anastomosis and thrombus formation. The stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, MW 1419) is a small anti-ulcer peptide efficient in inflammatory bowel disease trials (PL 14736) and various wound treatment, no toxicity reported. After 24 h following aortic termino-terminal anastomosis, we shown that BPC 157 (10 microg/kg) may also decrease formation of cloth after aortic termino-terminal anastomosis and preserved walking ability and muscle strength when given as a bath immediately after aortic anastomosis creation. This may be important since aortic termino-terminal anastomosis is normally presenting in rats with a formed cloth obstructing more than third of aortic lumen, severely impaired walking ability, painful screaming and weak muscle strength. Thereby, the effect of BPC 157 (10 microg/kg) was additionally studied at 24 h following aortic termino-terminal anastomosis. Given at the that point, intraperitoneally, within 3 minutes post-application interval the pentadecapeptide BPC 157 rapidly recovered the function of lower limbs and muscle strength while no cloth could be seen in those rats at the anastomosis site.

  1. Vascular diameter determining the magnification for a microvascular anastomosis. (United States)

    Andrades, Patricio; Benítez, Susana; Danilla, Stefan; Erazo, Cristian; Hasbun, Andrea; Fix, Jobe


    The purpose of this study was to determine the association between vascular diameters and amount of magnification and to assess the influence of the magnification media on the microanastomosis quality and permeability. Sixty arterial microanostomoses were distributed into three groups: group I (diameter 1.5 mm), group II (1.5 to 2.5 mm), and group III (> 2.5 mm). The models used were carotid artery of Sprague-Dawley rats and carotid and abdominal artery of wild rabbits. In each group, 10 anastomoses were performed with 2.5 x loupes and 10 with 10 x microscope. The total time of anastomosis, the quality of the anastomosis (Gorman scale), and 24-hour permeability rate were measured. The total anastomotic time and quality had statistical differences for the microscope by analyzing the total sample and group I only. The global permeability was 83% for the microscope and 40% for the loupe. The same result was observed in group I but no differences were observed in the other groups. The histology and the survey showed similar results. Microanastomoses performed under a microscope (10 x) were performed in less time, were of better quality, and had higher permeability rates when compared with those performed under a loupe (2.5 x). In vessels 1.5 mm no differences were observed.

  2. Ileoanal anastomosis with proximal ileal reservoir: an experimental study. (United States)

    Schraut, W H; Block, G E


    Endorectal ileoanal anastomosis with proximal interposition of an ileal reservoir was evaluated experimentally in dogs as an approach to retain sphincteric control of defecation after proctocolectomy. Two months after the operative procedure, eight animals with a reservoir had four to eight semisolid stools per day and were continent. In contrast, six animals with straight ileoanal anastomosis were incontinent with 10 to 14 evacuations per day. Motility studies demonstrated a reduction of propulsive peristalsis within the undistended reservoir, which is considered the responsible factor for increased intestinal transit time and reduced stool frequency. Filling of the reservoir to capacity elicited strong peristaltic contractions, which may assure a more complete evacuation of the reservoir during defecation. Reservoir capacity increased substantially (150% to 200%) within 2 months but only to a minor degree thereafter, indicating that the reservoir does not dilate progressively into an atonic viscus. Motility patterns remained unaltered as the reservoir became more complaint with time. Mucosal alterations (flattening of villi, submucosal inflammation) were detected in the reservoir but did not result in nutritional defects within an observation period of 1 year.

  3. Compatibility and incompatibility in hyphal anastomosis of arbuscular mycorrhizal fungi

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    Candido Barreto de Novais

    Full Text Available ABSTRACT: Arbuscular mycorrhizal fungi (AMF, which live in symbiosis with 80 % of plants, are not able to grow when separated from their hosts. Spore germination is not host-regulated and germling growth is shortly arrested in the absence of host roots. Germling survival chances may be increased by hyphal fusions (anastomoses, which allow access to nutrients flowing in the extraradical mycelium (ERM. Perfect anastomoses, occurring with high frequency among germlings and the ERM of the same isolate, show protoplasm continuity and disappearance of hyphal walls. A low frequency of perfect fusions has been detected among co-specific genetically different isolates, although fungal nuclei have been consistently detected in all perfect fusions, suggesting active nuclear migration. When plants of different taxa establish symbioses with the same AMF species, anastomoses between ERM spreading from single root systems establish a common mycelium, which is an essential element to plant nutrition and communication. The interaction among mycelia produced by different isolates may also lead to pre-fusion incompatibility which hinders anastomosis formation, or to incompatibility after fusion, which separates the hyphal compartments. Results reported here, obtained by analyses of hyphal compatibility/incompatibility in AMF, suggest that anastomosis formation and establishment of protoplasm flow, fundamental to the maintenance of mycelial physiological and genetic continuity, may affect the fitness of these ecologically important biotrophic fungi.

  4. Advantages of Robotic Right Colectomy With Intracorporeal Anastomosis. (United States)

    Lujan, Henry J; Plasencia, Gustavo; Rivera, Brian X; Molano, Andres; Fagenson, Alex; Jane, Louis A; Holguin, Diego


    Through retrospective review of consecutive charts, we compare the short-term and long-term clinical outcomes after robotic-assisted right colectomy with intracorporeal anastomosis (RIA) (n=89) and laparoscopic right colectomy with extracorporeal anastomosis (LEA) (n=135). Cohorts were similar in demographic characteristics, comorbidities, pathology, and perioperative outcomes (conversion, days to flatus and bowel movement, and length of hospitalization). The RIA cohort experienced statistically significant: less blood loss, shorter incision lengths, and longer specimen lengths than the LEA cohort. Operative times were significantly longer for the RIA group. No incisional hernias occurred in the RIA group, whereas the LEA group had 5 incisional hernias; mean follow-up was 33 and 30 months, respectively. RIA is effective and safe and provides some clinical advantages. Future studies may show that, in obese and other technically challenging patients, RIA facilitates resection of a longer, consistent specimen with less mesentery trauma that can be extracted through smaller incisions.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  5. Usefulness of continuous suture using short-thread double-armed micro-suture for cerebral vascular anastomosis


    Sei Haga; Shinji Nagata


    Background: When microvascular anastomosis is performed in a deep, narrow operating field, securing space to throw knots is difficult. To simplify the procedure and avoid obstruction of the anastomosis, we use a continuous suturing with short-thread double-armed micro-suture. Methods: Sixty-four patients (38 cerebral revasculazation, 16 moyamoya disease, and 10 aneurysm surgery) undergoing microvaucular anastomosis were included. During anastomosis, a continuous suture was placed with sho...

  6. Effect of shelf aging on O-ring materials (United States)

    Wood, T. E.; Stone, W. P.


    Commercial O-rings made from 13 different rubber compounds were tested for physical properties after 7 and 12 years of shelf aging. No gross changes were observed in tensile strength, elongation, or compression deflection characteristics.

  7. The Hand-sewn Anastomosis with an Absorbable Bidirectional Monofilament Barbed Suture Stratafix® During Laparoscopic One Anastomosis Loop Gastric Bypass. Retrospective Study in 50 Patients. (United States)

    Blanc, Pierre; Lointier, Patrice; Breton, Christophe; Debs, Tarek; Kassir, Radwan


    Laparoscopic One Anastomosis Gastric Bypass (LOAGB) is one of the main bariatric procedures that require a safe and reproducible gastrojejunal anastomosis. Barbed suture has been widely used for surgery in recent years; however, few studies have reported their use for gastro-intestinal anastomosis. We proposed their use for totally hand-sewn anastomosis during LOAGB. The objective of this study is to evaluate the risk of leaks and stenosis after a hand-sewn anastomosis using an absorbable bidirectional monofilament barbed suture: Stratafix®. The study was done in a private practice setting. Between April and November 2014, 50 consecutive patients undergoing a hand-sewn antecolic, antegastric gastrojejunal anastomosis (GJA) using Stratafix®. Pre, intra, and postoperative parameters were assessed for these patients. No fistulas or anastomotic stenosis had occurred up to 6 months after surgery. All procedures were completed laparoscopically, and no intraoperative complications occurred. The mean length of hospital stay was 3 days. The use of an absorbable bidirectional monofilament barbed suture for the GJA was safe. Further prospective studies with a higher number of patients are needed to address the safety and efficacy of the absorbable bidirectional monofilament barbed suture in bariatric surgery.

  8. The Complete Genome of a New Betabaculovirus from Clostera anastomosis.

    Directory of Open Access Journals (Sweden)

    Feifei Yin

    Full Text Available Clostera anastomosis (Lepidoptera: Notodontidae is a defoliating forest insect pest. Clostera anastomosis granulovirus-B (ClasGV-B belonging to the genus Betabaculovirus of family Baculoviridae has been used for biological control of the pest. Here we reported the full genome sequence of ClasGV-B and compared it to other previously sequenced baculoviruses. The circular double-stranded DNA genome is 107,439 bp in length, with a G+C content of 37.8% and contains 123 open reading frames (ORFs representing 93% of the genome. ClasGV-B contains 37 baculovirus core genes, 25 lepidopteran baculovirus specific genes, 19 betabaculovirus specific genes, 39 other genes with homologues to baculoviruses and 3 ORFs unique to ClasGV-B. Hrs appear to be absent from the ClasGV-B genome, however, two non-hr repeats were found. Phylogenetic tree based on 37 core genes from 73 baculovirus genomes placed ClasGV-B in the clade b of betabaculoviruses and was most closely related to Erinnyis ello GV (ErelGV. The gene arrangement of ClasGV-B also shared the strongest collinearity with ErelGV but differed from Clostera anachoreta GV (ClanGV, Clostera anastomosis GV-A (ClasGV-A, previously also called CaLGV and Epinotia aporema GV (EpapGV with a 20 kb inversion. ClasGV-B genome contains three copies of polyhedron envelope protein gene (pep and phylogenetic tree divides the PEPs of betabaculoviruses into three major clades: PEP-1, PEP-2 and PEP/P10. ClasGV-B also contains three homologues of P10 which all harbor an N-terminal coiled-coil domain and a C-terminal basic sequence. ClasGV-B encodes three fibroblast growth factor (FGF homologues which are conserved in all sequenced betabaculoviruses. Phylogenetic analysis placed these three FGFs into different groups and suggested that the FGFs were evolved at the early stage of the betabaculovirus expansion. ClasGV-B is different from previously reported ClasGV-A and ClanGV isolated from Notodontidae in sequence and gene

  9. The Complete Genome of a New Betabaculovirus from Clostera anastomosis (United States)

    Yin, Feifei; Zhu, Zheng; Liu, Xiaoping; Hou, Dianhai; Wang, Jun; Zhang, Lei; Wang, Manli; Kou, Zheng; Wang, Hualin; Deng, Fei; Hu, Zhihong


    Clostera anastomosis (Lepidoptera: Notodontidae) is a defoliating forest insect pest. Clostera anastomosis granulovirus-B (ClasGV-B) belonging to the genus Betabaculovirus of family Baculoviridae has been used for biological control of the pest. Here we reported the full genome sequence of ClasGV-B and compared it to other previously sequenced baculoviruses. The circular double-stranded DNA genome is 107,439 bp in length, with a G+C content of 37.8% and contains 123 open reading frames (ORFs) representing 93% of the genome. ClasGV-B contains 37 baculovirus core genes, 25 lepidopteran baculovirus specific genes, 19 betabaculovirus specific genes, 39 other genes with homologues to baculoviruses and 3 ORFs unique to ClasGV-B. Hrs appear to be absent from the ClasGV-B genome, however, two non-hr repeats were found. Phylogenetic tree based on 37 core genes from 73 baculovirus genomes placed ClasGV-B in the clade b of betabaculoviruses and was most closely related to Erinnyis ello GV (ErelGV). The gene arrangement of ClasGV-B also shared the strongest collinearity with ErelGV but differed from Clostera anachoreta GV (ClanGV), Clostera anastomosis GV-A (ClasGV-A, previously also called CaLGV) and Epinotia aporema GV (EpapGV) with a 20 kb inversion. ClasGV-B genome contains three copies of polyhedron envelope protein gene (pep) and phylogenetic tree divides the PEPs of betabaculoviruses into three major clades: PEP-1, PEP-2 and PEP/P10. ClasGV-B also contains three homologues of P10 which all harbor an N-terminal coiled-coil domain and a C-terminal basic sequence. ClasGV-B encodes three fibroblast growth factor (FGF) homologues which are conserved in all sequenced betabaculoviruses. Phylogenetic analysis placed these three FGFs into different groups and suggested that the FGFs were evolved at the early stage of the betabaculovirus expansion. ClasGV-B is different from previously reported ClasGV-A and ClanGV isolated from Notodontidae in sequence and gene arrangement

  10. Sealing Out-Of-Round Tubes With O-Rings (United States)

    Shlichta, Paul J.


    Glass or ceramic tubes out-of-round sealed effectively by ordinary O-rings in caps of modified hydraulic fittings. In typical connection, O-ring squeezed between two surfaces having inward-opening slants of 5 degrees or 10 degrees. Slanted surfaces force ring inward, compressing it around tube. Connector metal fitting, tightened by hand around O-ring, seals O-ring against tube as much as 1/16 in. out of round. Modified connectors seal glass or ceramic tubes against gas or vacuum leakage in furnaces, vacuum systems, and tubes for glassblowing equipment.

  11. Sutureless microvascular anastomosis assisted by an expandable shape-memory alloy stent. (United States)

    Saegusa, Noriko; Sarukawa, Shunji; Ohta, Kunihiro; Takamatsu, Kensuke; Watanabe, Mitsuhiro; Sugino, Takashi; Nakagawa, Masahiro; Akiyama, Yasuto; Kusuhara, Masatoshi; Kishi, Kazuo; Inoue, Keita


    Vascular anastomosis is the highlight of cardiovascular, transplant, and reconstructive surgery, which has long been performed by hand using a needle and suture. However, anastomotic thrombosis occurs in approximately 0.5-10% of cases, which can cause serious complications. To improve the surgical outcomes, attempts to develop devices for vascular anastomosis have been made, but they have had limitations in handling, cost, patency rate, and strength at the anastomotic site. Recently, indwelling metal stents have been greatly improved with precise laser metalwork through programming technology. In the present study, we designed a bare metal stent, Microstent, that was constructed by laser machining of a shape-memory alloy, NiTi. An end-to-end microvascular anastomosis was performed in SD rats by placing the Microstent at the anastomotic site and gluing the junction. The operation time for the anastomosis was significantly shortened using Microstent. Thrombus formation, patency rate, and blood vessel strength in the Microstent anastomosis were superior or comparable to hand-sewn anastomosis. The results demonstrated the safety and effectiveness, as well as the operability, of the new method, suggesting its great benefit for surgeons by simplifying the technique for microvascular anastomosis.

  12. Ostomy or intestinal anastomosis in cases of peritonitis

    Directory of Open Access Journals (Sweden)

    Samir Rasslan

    Full Text Available Twenty-six patients showing peritonitis due to nontraumatic acute abdomen were submitted to ostomy. Mean age was 51 years (range 25-83, being 13 males and 13 females. Bowel obstruction (BO was the most frequent cause of peritonitis (11 cases, followed by intestinal perforation (IP (8 cases, acute mesenteric infarction (AMI (5 cases, and acute abdomen of inflammatory / infectious origin (AAIO (2 cases. Brook's ileostomy was performed on 65% of the patients. Jejunostomy was performed only in 4 patients, leading to a bad evolution. Overall mortality was 54%. Primary ostomy or anastomosis in cases of peritonitis constitute a highly controversial theme. Indications and problems involving the intestinal exteriorization in emergency surgery urgency are herein discussed.

  13. Infliximab treatment reduces tensile strength in intestinal anastomosis

    DEFF Research Database (Denmark)

    Jensen, Jonas Sanberg; Petersen, Nacie Bello; Biagini, Matteo


    :1) to receive either repeated IFX treatment or placebo. On day 15, three separate end-to-end anastomoses were performed on the jejunum. On postoperative day 5, tensile strength and bursting pressure for the anastomoses were tested and histologic changes examined. RESULTS: We found a significantly reduced...... tensile strength in the IFX group (1.94 +/- 0.44 N) compared with the placebo group (3.33 +/- 0.39 N), (P tensile strength and serum values of IFX (coefficient = -0.63; P = 0.003) as well...... as number of sutures in the tested anastomosis (coefficient = 0.51; P = 0.024). The general histologic score was significantly higher in the placebo group (5.00 +/- 1.26 versus 3.31 +/- 1.65, P = 0.03). CONCLUSIONS: Repeated high-dose IFX treatment reduces tensile strength significantly in rabbits...

  14. Fingertip Reconstruction Using Free Toe Tissue Transfer Without Venous Anastomosis

    Directory of Open Access Journals (Sweden)

    Won Young Yoon


    Full Text Available BackgroundThis study was designed to introduce the feasibility of toe tissue transfer without venous outflow for fingertip reconstruction.MethodsFive cases of fingertip defects were treated successfully with this method. Four cases were traumatic fingertip defects, and one case was a hook-nail deformity. The lateral pulp of a great toe or medioinferior portion of a second toe was used as the donor site. An arterial pedicle was dissected only within the digit and anastomosis was performed within 2 cm around the defect margin. The digital nerve was repaired simultaneously. No additional dissection of the dorsal or volar pulp vein was performed in either the donor or recipient sites. Other surgical procedures were performed following conventional techniques. Postoperative venous congestion was monitored with pulp temperature, color, and degree of tissue oxygen saturation. Venous congestion was decompressed with a needle-puncture method intermittently, but did not require continuous external bleeding for salvage.ResultsVenous congestion was observed in all the flaps, but improved within 3 or 4 days postoperatively. The flap size was from 1.5×1.5 cm2 to 2.0×3.0 cm2. The mean surgical time was 2 hours and 20 minutes. A needle puncture was carried out every 2 hours during the first postoperative day, and then every 4 hours thereafter. The amount of blood loss during each puncture procedure was less than 0.2 mL. In the long-term follow-up, no flap atrophy was observed.ConclusionsWhen used properly, the free toe tissue transfer without venous anastomosis method can be a treatment option for small defects on the fingertip area.

  15. Comprehensive Analysis of Chicken Vessels as Microvascular Anastomosis Training Model

    Directory of Open Access Journals (Sweden)

    Bo Young Kang


    Full Text Available BackgroundNonliving chickens are commonly used as a microvascular anastomosis training model. However, previous studies have investigated only a few types of vessel, and no study has compared the characteristics of the various vessels. The present study evaluated the anatomic characteristics of various chicken vessels as a training model.MethodsEight vessels—the brachial artery, basilic vein, radial artery, ulnar artery, ischiatic artery and vein, cranial tibial artery, and common dorsal metatarsal artery—were evaluated in 26 fresh chickens and 30 chicken feet for external diameter (ED and thicknesses of the tunica adventitia and media. The dissection time from skin incision to application of vessel clamps was also measured.ResultsThe EDs of the vessels varied. The ischiatic vein had the largest ED of 2.69±0.33 mm, followed by the basilic vein (1.88±0.36 mm, ischiatic artery (1.68±0.24 mm, common dorsal metatarsal artery (1.23±0.23 mm, cranial tibial artery (1.18±0.19 mm, brachial artery (1.08±0.15 mm, ulnar artery (0.82±0.13 mm, and radial artery (0.56±0.12 mm, and the order of size was consistent across all subjects. Thicknesses of the tunica adventitia and media were also diverse, ranging from 74.09±19.91 µm to 158.66±40.25 µm (adventitia and from 31.2±7.13 µm to 154.15±46.48 µm (media, respectively. Mean dissection time was <3 minutes for all vessels.ConclusionsOur results suggest that nonliving chickens can provide various vessels with different anatomic characteristics, which can allow trainees the choice of an appropriate microvascular anastomosis training model depending on their purpose and skillfulness.

  16. Myofibroblasts and colonic anastomosis healing in Wistar rats

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    Vasiliadou Kalliopi


    Full Text Available Abstract Background The myofibroblasts play a central role in wound healing throughout the body. The process of wound healing in the colon was evaluated with emphasis on the role of myofibroblasts. Methods One hundred male Wistar rats weighing 274 ± 9.1 g (mean age: 3.5 months were used. A left colonic segment was transected and the colon was re-anastomosed. Animals were randomly divided into two groups. The first group experimental animals (n = 50 were sacrificed on postoperative day 3, while the second group rats (n = 50 were sacrificed on postoperative day 7. Healing of colonic anastomosis was studied in terms of anastomotic bursting pressure, as well as myofibroblastic reaction and expression of α-smooth muscle actin (α-SMA, adhesion formation, inflammatory reaction and neovascularization. Results The mean anastomotic bursting pressure increased from 20.6 ± 3.5 mmHg on the 3rd postoperative day to 148.8 ± 9.6 Hg on the 7th postoperative day. Adhesion formation was increased on the 7th day, as compared to the 3rd day. In addition, the myofibroblastic reaction was more profound on the 7th postoperative day in comparison with the 3rd postoperative day. The staining intensity for α-SMA was progressive from the 3rd to the 7th postoperative day. On the 7th day the α-SMA staining in the myofibroblats reached the level of muscular layer cells. Conclusions Our study emphasizes the pivotal role of myofibroblasts in the process of colonic anastomosis healing. The findings provide an explanation for the reduction in the incidence of wound dehiscence after the 7th postoperative day.

  17. Anastomosis behavior differs between asymbiotic and symbiotic hyphae of Rhizophagus clarus. (United States)

    Purin, Sonia; Morton, Joseph B


    The life history of arbuscular mycorrhizal fungi (AMF, Glomeromycota) consists of a short asymbiotic phase when spores germinate and a longer symbiotic phase where hyphae form a network within roots and subsequently in the rhizosphere. Hyphal anastomosis contributes to colony formation, yet this process has been studied mostly in the asymbiotic phase rather than in mycorrhizal plants because of methodological limitations. We sought to compare patterns of anastomosis during each phase of fungal growth by measuring hyphal fusions in genetically identical and different single spore isolates of Rhizophagus clarus from different environments and geographic locations. These isolates were genotyped with two anonymous markers of microsatellite-flanking regions. Anastomosis of hyphae from germinating spores was examined in axenic Petri dishes. A rhizohyphatron consisting of agar-coated glass slides bridging single or paired mycorrhizal sorghum plants allowed evaluation of anastomosis of symbiotic hyphae. Anastomosis of hyphae within a colony, defined here as a mycelium from an individual germinating spore or from mycorrhizal roots of one plant, occurred with similar frequencies (8-38%). However, anastomosis between paired colonies was observed in germinating spores from either genetically identical or different isolates, but it was never detected in symbiotic hyphae. The frequency of anastomosis in asymbiotic hyphae from paired interactions was low, occurring in fewer than 6% of hyphal contacts. These data suggest that anastomosis is relatively unconstrained when interactions occur within a colony but is confined to asymbiotic hyphae when interactions occur between paired colonies. This pattern of behavior suggests that asymbiotic and symbiotic phases of mycelium development by R. clarus may differ in function. Anastomosis in the asymbiotic phase may provide brief opportunities for gene flow between populations of this and possibly other AMF species.

  18. Robot-assisted Ivor-Lewis esophagectomy with intrathoracic robot-sewn anastomosis. (United States)

    Jin, Runsen; Xiang, Jie; Han, Dingpei; Zhang, Yajie; Li, Hecheng


    This video clip demonstrated a performance of robot-assisted Ivor-Lewis esophagectomy with intrathoracic robot-sewn anastomosis. The patient had an esophageal mass located approximately 33 cm away from incisor, and robot-assisted Ivor-Lewis esophagectomy was applied for him. Importantly, a double-layer esophago-gastric anastomosis was made by robotic hand-sewn suture. Our early experience demonstrated that the robot-sewn intrathoracic anastomosis is feasible and safe with a lower complication rate and the absence of anastomotic leakage.

  19. Effects of sodium hypochlorite and ozone on healing of intestinal anastomosis in simulated strangulation colorectal obstruction. (United States)

    Lelyanov, A D; Sergienko, V I; Ivliev, N V; Emel'yanov, V V; Guseva, E D


    Strangulation colorectal obstruction was modeled in 60 Wistar rats. Necrotic segment of the intestine was resected under conditions of peritonitis and end-to-end intestinal anastomosis was performed on a PCV catheter conducted through the anus. Sodium hypochlorite and ozone solution were used for sanitation of the abdominal cavity and intestinal lavage, and the intestinal anastomosis was coated with Ozonide (ozonized oil). The use of physicochemical methods notably reduced the incidence of postoperative pyoinflammatory complications, incompetence of intestinal anastomosis sutures, and animal mortality.

  20. Robot-assisted Ivor-Lewis esophagectomy with intrathoracic robot-sewn anastomosis (United States)

    Jin, Runsen; Xiang, Jie; Han, Dingpei; Zhang, Yajie


    This video clip demonstrated a performance of robot-assisted Ivor-Lewis esophagectomy with intrathoracic robot-sewn anastomosis. The patient had an esophageal mass located approximately 33 cm away from incisor, and robot-assisted Ivor-Lewis esophagectomy was applied for him. Importantly, a double-layer esophago-gastric anastomosis was made by robotic hand-sewn suture. Our early experience demonstrated that the robot-sewn intrathoracic anastomosis is feasible and safe with a lower complication rate and the absence of anastomotic leakage. PMID:29268555

  1. Compressive beamforming

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Mosegaard, Klaus


    Sound source localization with sensor arrays involves the estimation of the direction-of-arrival (DOA) from a limited number of observations. Compressive sensing (CS) solves such underdetermined problems achieving sparsity, thus improved resolution, and can be solved efficiently with convex...

  2. Radical theory of rings

    CERN Document Server

    Gardner, JW


    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  3. Open versus laparoscopic (assisted) ileo pouch anal anastomosis for ulcerative colitis and familial adenomatous polyposis

    NARCIS (Netherlands)

    Ali, Usama Ahmed; Keus, Frederik; Heikens, Joost T.; Bemelman, Willem A.; Berdah, Stephane V.; Gooszen, H. G.; van Laarhoven, Cees J. H. M.


    Background Restorative proctocolectomy with ileo pouch anal anastomosis (IPAA) is the main surgical treatment for patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). With the advancements of minimal-invasive surgery this demanding operation is increasingly being performed

  4. Saturn's Spectacular Ring System (United States)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)


    Saturn's beautiful rings have fascinated astronomers since they were first observed by Galileo in 1610. The main rings consist of solid particles mostly in the 1 cm - 10 m range, composed primarily of water ice. The ring disk is exceptionally thin - the typical local thickness of the bright rings is tens of meters, whereas the diameter of the main rings is 250,000 km! The main rings exhibit substantial radial variations "ringlets", many of which are actively maintained via gravitational perturbations from Saturn's moons. Exterior to the main rings lie tenuous dust rings, which have little mass but occupy a very large volume of space. This seminar will emphasize the physics of ring-moon interactions, recent advances in our understanding of various aspects of the rings obtained from observations taken during 1995 when the rings appeared edge-on to the Earth and then to the Sun, and observations in subsequent years from HST.

  5. Bovine pericardium patch wrapping intestinal anastomosis improves healing process and prevents leakage in a pig model.

    Directory of Open Access Journals (Sweden)

    Mario Testini

    Full Text Available Failure of intestinal anastomosis is a major complication following abdominal surgery. Biological materials have been introduced as reinforcement of abdominal wall hernia in contaminated setting. An innovative application of biological patch is its use as reinforcement of gastrointestinal anastomosis. The aim of study was to verify whether the bovine pericardium patch improves the healing of anastomosis, when in vivo wrapping the suture line of pig intestinal anastomosis, avoiding leakage in the event of deliberately incomplete suture. Forty-three pigs were randomly divided: Group 1 (control, n = 14: hand-sewn ileo-ileal and colo-colic anastomosis; Group 2 (n = 14: standard anastomosis wrapped by pericardium bovine patch; Group 3 (n = 1 and 4 (n = 14: one suture was deliberately incomplete and also wrapped by patch in the last one. Intraoperative evaluation, histological, biochemical, tensiometric and electrophysiological studies of intestinal specimens were performed at 48 h, 7 and 90 days after. In groups 2 and 4, no leak, stenosis, abscess, peritonitis, mesh displacement or shrinkage were found and adhesion rate decreased compared to control. Biochemical studies showed mitochondrial function improvement in colic wrapped anastomosis. Tensiometric evaluations suggested that the patch preserves the colic contractility similar to the controls. Electrophysiological results demonstrated that the patch also improves the mucosal function restoring almost normal transport properties. Use of pericardium bovine patch as reinforcement of intestinal anastomosis is safe and effective, significantly improving the healing process. Data of prevention of acute peritonitis and leakage in cases of iatrogenic perforation of anastomoses, covered with patch, is unpublished.

  6. Portal flow into the liver through veins at the site of biliary-enteric anastomosis. (United States)

    Hashimoto, M; Heianna, J; Yasuda, K; Tate, E; Watarai, J; Shibata, S; Sato, T; Yamamoto, Y


    The aim of this study was to establish the role played by jejunal veins in hepatopetal flow after biliary-enteric anastomosis and to evaluate the helical CT features of hepatopetal flow through the anastomosis. We retrospectively analyzed helical CT images of the liver in 31 patients with biliary-enteric anastomosis who underwent hepatic angiography with (n=13) or without (n=18) CT arterial portography within 2 weeks of the CT examination during the last 4 years. Arterial portography showed hepatopetal flow through small vessels located (communicating veins) between the elevated jejunal veins and the intrahepatic portal branches in two (9%) of 22 patients with a normal portal system. Helical CT showed focal parenchymal enhancement around the anastomosis in these two patients. All nine patients with extrahepatic portal vein occlusion (100%) had hepatopetal flow through the anastomosis, and four of the nine had decreased portal flow. CT revealed small communicating veins in two of these four patients. In five patients with normal portal perfusion despite extrahepatic portal vein occlusion, CT detected dilated communicating veins and elevated jejunal veins. The presence of communicating veins and/or focal parenchymal enhancement around the anastomosis indicates hepatopetal flow through the elevated jejunal veins.

  7. Deep organ space infection after emergency bowel resection and anastomosis: The anatomic site does not matter. (United States)

    Benjamin, Elizabeth; Siboni, Stefano; Haltmeier, Tobias; Inaba, Kenji; Lam, Lydia; Demetriades, Demetrios


    Deep organ space infection (DOSI) is a serious complication after emergency bowel resection and anastomosis. The aim of this study was to identify the incidence and risk factors for the development of DOSI. National Surgical Quality Improvement Program database study including patients who underwent large bowel or small bowel resection and primary anastomosis. The incidence, outcomes, and risk factors for DOSI were evaluated using univariate and multivariate analyses. A total of 87,562 patients underwent small bowel, large bowel, or rectal resection and anastomosis. Of these, 14,942 (17.1%) underwent emergency operations and formed the study population. The overall mortality rate in emergency operations was 12.5%, and the rate of DOSI was 5.6%. A total of 18.0% required ventilatory support in more than 48 hours, and 16.0% required reoperation. Predictors of DOSI included age, steroid use, sepsis or septic shock on admission, severe wound contamination, and advanced American Society of Anesthesiologists classification. The anatomic location of resection and anastomosis was not significantly associated with DOSI. Patients undergoing emergency bowel resection and anastomosis have a high mortality, risk of DOSI, and systemic complications. Independent predictors of DOSI include wound and American Society of Anesthesiologists classification, sepsis or septic shock on admission, and steroid use. The anatomic location of resection and anastomosis was not significantly associated with DOSI. Epidemiologic/prognostic study, level III.

  8. Experimental study of sutureless vascular anastomosis with use of glued prosthesis in rabbits. (United States)

    Vokrri, Lulzim; Qavdarbasha, Arsim; Rudari, Hajriz; Ahmetaj, Halil; Manxhuka-Kërliu, Suzana; Hyseni, Nexhmi; Porcu, Paolo; Cinquin, Philippe; Sessa, Carmine


    The objective of this study is to explore the feasibility and efficacy of a new technique for sutureless vascular anastomosis, using glued prosthesis, as a sole anastomosis fixation method in rabbits. Ten rabbits were randomly selected to conduct the experiment. Five rabbits underwent direct anastomosis of infrarenal abdominal aorta, with glued prosthesis. In five other rabbits, reconstruction was done by sutured anastomosis. All animals were immediately examined by echo-Doppler for patency of anastomosis. The burst pressure of the glued anastomosis was measured and compared with that of a sutured artery. The animals were euthanized, and tissue samples were taken for histological examination immediately after the experiment. Compared to conventional anastomoses, sutureless vascular anastomoses required shorter time of creation and significantly reduced blood loss (Pprosthesis, examined by echo-Doppler, were patent at the anastomotic site, except one, which was stenosed immediately after surgery. In the control group, except one with stenosis, all conventional anastomoses were patent. Mean burst pressure at the anastomotic site for sutureless anastomoses was lower than in control group. Macroscopically, the BioGlue did not demonstrate any adhesion to the surrounding tissue as it was covered by the vascular prosthesis. Histological examination showed low-grade inflammatory reaction in glued anastomoses versus no inflammatory reaction at the sutured anastomoses. This technique may provide a feasible and successful alternative in vascular surgery. However, further long-term studies are necessary to elucidate the break pressure and degree of inflammation at the anastomotic site.

  9. Speech Compression

    Directory of Open Access Journals (Sweden)

    Jerry D. Gibson


    Full Text Available Speech compression is a key technology underlying digital cellular communications, VoIP, voicemail, and voice response systems. We trace the evolution of speech coding based on the linear prediction model, highlight the key milestones in speech coding, and outline the structures of the most important speech coding standards. Current challenges, future research directions, fundamental limits on performance, and the critical open problem of speech coding for emergency first responders are all discussed.

  10. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C


    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  11. Comparison of the axial stiffness of carbon composite and aluminium alloy circular external skeletal fixator rings. (United States)

    Gauthier, C M; Kowaleski, M P; Gerard, P D; Rovesti, G L


    The purpose of this study was to compare the axial stiffness of aluminium alloy and carbon composite single-ring constructs. Single-ring constructs were made with rings of different material compositions (aluminium alloy and carbon composite), diameters (55 mm, 85 mm, and 115 mm), and thicknesses (6 mm for the single-ring, 12 mm for the double-ring) with all other components remaining constant. Stiffness of each construct was determined under loading in axial compression with a materials testing machine. The axial stiffness of each group was compared using a three-factor factorial analysis of variance investigating all main effects and interactions between ring diameter, ring thickness, and ring material composition; p <0.05 was considered significant. Carbon composite constructs were 16-55% as stiff as corresponding aluminium alloy constructs. Within each combination of ring material composition and ring diameter, stiffness did not significantly increase when the ring thickness was doubled. Within each combination of ring material composition and ring thickness, stiffness significantly decreased with increased ring diameter. Aluminium alloy rings were found to be significantly stiffer than carbon composite rings. Although the carbon composite rings were considerably less stiff, clinical recommendations cannot be made from a single-ring in vitro analysis. Further studies are needed to evaluate the behaviour of these rings in vivo.

  12. CO2 vascular anastomosis of atherosclerotic and calcified arteries (United States)

    White, John V.; Leefmans, Eric; Stewart, Gwendolyn J.; Katz, Mira L.; Comerota, Anthony J.


    The technique for CO2 laser fusion vascular anastomosis in normal vessels has been well established. Normal arterial wall has a predictable thermal response to the incident laser energy, with rapid heating and cooling of collagen within the arterial wall. Since atherosclerosis involves subendothelial cellular proliferation, lipid and calcium deposition, it may modify the thermal responsiveness of the arterial wall. To this study, CO2 laser fusion anastomoses were attempted in rabbits with non-calcific atherosclerosis and humans with calcific atherosclerosis. All anastomoses were successfully completed without alteration in technique despite the presence of plaque at the site of laser fusion. Histology of rabbit vessels revealed the classic laser fusion cap within the adventitia and persistent atherosclerotic plaque at the flow surface. Duplex imaging of patients post-operatively demonstrated long term anastomotic patency in 2 of 3 fistulae. These results suggest that neither non-calcified or calcified atherosclerosis significantly alters the arterial wall thermal responsiveness to CO2 laser energy or inhibits creation of laser fusion anastomoses. Therefore, this technique may be applicable to the treatment of patients with atherosclerotic occlusive disease.

  13. [Laparoscopic antevasal uretero-ureteral anastomosis for treating retrocaval ureter]. (United States)

    Komyakov, B K; Guliev, B G; Idrisov, Sh N; Shibliev, R G


    The article presents a case of laparoscopic antevasal correction of the retrocaval ureter in a 16 year old patient, who was admitted to the hospital with complaints of aching pain in the right lower back. His history was noteworthy of early age onset of intermittent fever accompanied by abdominal and lumbar pain. Blood count and urinalysis were within normal limits, and he was treated symptomatically. However, no renal ultrasound scan was done. Intravenous urography and MSCT showed a retrocaval ureter. The diagnosis was confirmed by retrograde ureteropyelography. With the patient placed in the lateral position, the right ureter was mobilized by transperitoneal access, transected and mobilized from under the inferior vena cava. Anterior uretero-ureteral anastomosis on the stent was performed, drainage was established. The operating time was 90 minutes, blood loss was 60 ml. There were no postoperative complications. Drainage was removed 2 days after surgery and the patient was discharged for outpatient treatment. The stent was removed 6 weeks postoperatively. Control urography showed normal function of both kidneys, no urodynamic abnormality of the upper urinary tract was identified.

  14. The effects of ghrelin on colonic anastomosis healing in rats

    Directory of Open Access Journals (Sweden)

    Canan Ceran


    Full Text Available OBJECTIVES: In addition to its roles in the stimulation of growth hormone secretion and the regulation of appetite and metabolism, ghrelin exerts immunomodulatory, anti-inflammatory and antioxidant actions in several organ systems. In this study, we investigated the effects of ghrelin on the healing of experimental colonic anastomoses. METHODS: Wistar rats were randomly divided into two groups (n = 10 in each. A segment of colon was excised, and an end-to-end anastomosis was performed in the distal colon. The Ghrelin Group received 10 ng/kg/day IP ghrelin for seven days postoperatively, whereas the Control Group received an identical volume of saline. On the seventh postoperative day, the anastomotic bursting pressures and hydroxyproline levels were measured, and adhesion formation around the anastomoses was examined. Histopathological analyses were performed to evaluate inflammatory cell infiltration, fibroblast infiltration, collagen density and neovascularization. RESULTS: In the Ghrelin Group, the bursting pressure and hydroxyproline levels were significantly higher than in the Control Group. The adhesion formation scores were lower in the Ghrelin Group than in the Control Group. Although the inflammatory cell infiltration was diminished in the Ghrelin Group, the degrees of fibroblast infiltration, collagen density and neovascularization were not significantly different between the groups. CONCLUSION: Our results indicate that ghrelin improves the healing of colonic anastomoses in rats.

  15. Numerical Simulation of Piston Ring Lubrication

    DEFF Research Database (Denmark)

    Felter, Christian Lotz


    is extended to include also the oil film outside the piston rings. The numerical model consists of a 2D free surface code that solves the time dependent compressible Navier-Stokes equations. The equations are cast in Lagrangian form and discretized by a meshfree moving least squares method using the primitive...... and the angle between the normals of the solid and the free surface. The numerical model is compared with the results from an analytical solution of Reynolds equation for a fixed incline slider bearing. Then results from a more compli- cated simulation of piston ring lubrication is given and discussed....

  16. Impact of top end anastomosis design on patency and flow stability in coronary artery bypass grafting. (United States)

    Koyama, Sachi; Kitamura, Tadashi; Itatani, Keiichi; Yamamoto, Tadashi; Miyazaki, Shohei; Oka, Norihiko; Nakashima, Kouki; Horai, Tetsuya; Ono, Minoru; Miyaji, Kagami


    For coronary artery bypass grafting (CABG), free grafts such as a saphenous vein or radial artery are often used for grafts to the lateral and posterior walls. However, the relationship between top-end anastomosis design and long-term patency remains unknown. Because coronary artery blood flow is dominant during diastole, top-end anastomosis may work better if the graft is directed towards the apex, whereas the shortest graft pathway appears to be most efficient. Using computational fluid dynamic models, we evaluated the hemodynamic variables that were affected by the angle of the top-end anastomosis. We created three-dimensional geometries of the aortic root with coronary arteries that involved 75 % stenosis in the obtuse marginal and postero-lateral branches. Two bypass models under vasodilator administration were created: in a"Model A", the top-end anastomosis is parallel to the long axis of the ascending aorta and the graft passed over the conus directed towards the apex; in a "Model B", the top-end anastomosis is directed toward the shortest pathway, and form near the right angles to the long axis of the ascending aorta. Wall shear stress (WSS) and its fluctuation, an oscillatory shear index (OSI) were evaluated to predict fibrosis progression at the anastomosis site and graft flow. Graft flow was 197.3 ml/min and 207.3 ml/min in the "Model A" and "Model B", respectively. The minimal WSS value inside the graft with the "Model A" and "Model B" was 0.53 Pa and 4.09 Pa, respectively, and the OSI value was 0.46 and 0.04, respectively. The top-end anastomosis of a free graft should be directed vertically towards the aorta to achieve the shortest graft pathway to maintain a high graft flow rate and to avoid the risks of endothelial fibrosis and plaque progression over the long-term after CABG.

  17. Small bowel fibrosis and systemic inflammatory response after ileocolonic anastomosis in IL-10 null mice. (United States)

    Borowiec, Anna M; Sydora, Beate C; Doyle, Jason; Guan, Le Luo; Churchill, Thomas A; Madsen, Karen; Fedorak, Richard N


    Crohn's disease recurrence after an ileocecal resection is common; yet, its pathophysiology is poorly understood and available treatment is suboptimal. The purpose of this study was to examine the bacterial, local, and systemic immune changes that follow ileocolonic anastomosis in a rodent model of Crohn's disease, the interleukin-10 gene-deficient (IL-10 null) mice. We divided wild-type and IL-10 null mice into three treatment groups: ileocolonic anastomosis, sham operation (ileo-ileal anastomosis), and control group without an operation. We sacrificed mice at 6 and 15 wks after the operation. At 6 wks, we assessed bacterial changes using the denaturing gel electrophoresis and similarity coefficient calculation. At both time points, we examined the small bowel for inflammation and fibrosis with histology. We measured the interferon gamma secretion by splenocytes stimulated with gastrointestinal bacterial antigens and splenocyte composition as a marker of systemic response. At 6 wks, ileocolonic anastomosis resulted in increased similarity in bacterial species between the ileum and colon. The ileocolonic anastomosis did not lead to significant inflammation in the small intestine, but it resulted in an increased collagen deposition in all animals undergoing surgery, the most pronounced fibrosis of which was present in IL-10 null mice 15 wks after ileocolonic anastomosis. Furthermore, this was associated with significantly increased interferon gamma secretion by bacterial antigen-stimulated splenocytes and a decreased number of CD11+ cells in the same experimental group. Ileocolonic anastomosis leads to bacterial changes in the terminal ileum. In the genetically susceptible host, it is associated with small bowel fibrosis and systemic immune alterations. The composition of immune cells in the spleen is altered and splenocytes hypersecrete proinflammatory cytokine (interferon gamma) when challenged with gastrointestinal bacterial antigens. Copyright © 2012 Elsevier

  18. Intimal Surface Suture Line (End-Product) Assessment of End-to-Side Microvascular Anastomosis. (United States)

    Pafitanis, Georgios; Veljanoski, Damjan; Ghanem, Ali M; Myers, Simon


    Microsurgery simulation courses increasingly use assessment methodologies to evaluate the quality of microvascular anastomosis and to provide constructive feedback in competency-based training. Assessment tools evaluating the "journey" of skill acquisition in anastomosis have evolved, including global rating scores, hand motion analysis, and evaluation of the final outcome, that is, "end-product" assessment. Anastomotic patency is the gold standard end-product in clinical microvascular surgery, and in vivo end-to-side anastomosis, which can be confirmed using the Acland-test. Microsurgery simulation training is moving to include nonliving models, where possible, according to the principles of the replacement, reduction, and refinement of the use of animals in research. While a standardized end-product assessment tool for nonliving end-to-end anastomosis exists, there is no similar tool for end-to-side anastomosis. Intimal surface suture line assessment is an error list-based tool, which involves exposing the intimal surface of a vessel and analysis of the quality of suture placement. Errors in end-to side anastomosis were classified according to the potential clinical significance (high, medium, or low) perceived by the senior authors. Intimal surface suture line assessment provides constructive feedback during microsurgery training, helping to minimize technical errors, which are likely to impact on the final outcome in a clinical environment. Intimal surface suture line assessment lends itself to nonliving simulation training courses as an end-product self-assessment tool, especially during the early learning curve, to demonstrate progression. It has intraoperative relevance by assessment of the intimal surface suture line as the final sutures are placed in an end-to-side anastomosis to provide objective feedback to trainees in relation to likely physiological anastomotic outcome.

  19. Intimal Surface Suture Line (End-Product Assessment of End-to-Side Microvascular Anastomosis

    Directory of Open Access Journals (Sweden)

    Georgios Pafitanis, MD


    Full Text Available Summary:. Microsurgery simulation courses increasingly use assessment methodologies to evaluate the quality of microvascular anastomosis and to provide constructive feedback in competency-based training. Assessment tools evaluating the “journey” of skill acquisition in anastomosis have evolved, including global rating scores, hand motion analysis, and evaluation of the final outcome, that is, “end-product” assessment. Anastomotic patency is the gold standard end-product in clinical microvascular surgery, and in vivo end-to-side anastomosis, which can be confirmed using the Acland-test. Microsurgery simulation training is moving to include nonliving models, where possible, according to the principles of the replacement, reduction, and refinement of the use of animals in research. While a standardized end-product assessment tool for nonliving end-to-end anastomosis exists, there is no similar tool for end-to-side anastomosis. Intimal surface suture line assessment is an error list-based tool, which involves exposing the intimal surface of a vessel and analysis of the quality of suture placement. Errors in end-to side anastomosis were classified according to the potential clinical significance (high, medium, or low perceived by the senior authors. Intimal surface suture line assessment provides constructive feedback during microsurgery training, helping to minimize technical errors, which are likely to impact on the final outcome in a clinical environment. Intimal surface suture line assessment lends itself to nonliving simulation training courses as an end-product self-assessment tool, especially during the early learning curve, to demonstrate progression. It has intraoperative relevance by assessment of the intimal surface suture line as the final sutures are placed in an end-to-side anastomosis to provide objective feedback to trainees in relation to likely physiological anastomotic outcome.

  20. Minimally invasive oesophagectomy: preliminary results after introduction of an intrathoracic anastomosis. (United States)

    van Workum, Frans; van den Wildenberg, Frits J H; Polat, Fatih; de Wilt, Johannes H W; Rosman, Camiel


    Intrathoracic anastomosis after oesophagectomy has recently been associated with reduced functional morbidity compared to a cervical anastomosis. From January 2011 until August 2012, all operable patients were scheduled to undergo minimally invasive oesophagectomy (MIE) with intrathoracic anastomosis. Patient characteristics, complications, morbidity and mortality were prospectively registered and analysed. Forty-five patients underwent MIE with intrathoracic stapled end-to-side anastomosis. Major changes in operative technique were made 2 times due to non-satisfactory results, dividing the patients into 3 groups. One patient in group 1 died. The anastomotic leakage rate decreased from 44% in group 1 to 0% in groups 2 and 3 (p = 0.007). The pulmonary complication rate decreased from 67% in group 1 to 44% in group 2 (not significant, NS) and 22% in group 3 (p = 0.04). The median hospital stay decreased from 17 days in group 1 to 14 days in group 2 (NS) and 8 days in group 3 (p < 0.001). There were no stenoses, no dilatations and no patients with recurrent laryngeal nerve palsy. The introduction of the intrathoracic anastomosis led to favourable functional results but was initially associated with considerable morbidity. RESULTS improved after changing operative techniques, but the learning curve may also be responsible. © 2014 S. Karger AG, Basel.

  1. Carotid-anterior cerebral artery anastomosis on MR angiography: a university hospital-based study

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Saito, Naoko; Okada, Yoshitaka; Inoue, Kaiji [Saitama Medical University International Medical Center, Department of Diagnostic Radiology, Hidaka, Saitama (Japan)


    Rarely in the anterior circulation, an anastomosis of the carotid and anterior cerebral arteries occurs when an anomalous branch arises from the ophthalmic segment of the internal carotid artery and anastomoses with the A1-A2 junction of the anterior communicating artery. Right-side predominance is known. To our knowledge, the incidence of carotid-anterior cerebral artery anastomosis has not been reported, so we researched cases in our institution records to determine incidence and investigated characteristic features of the condition on magnetic resonance (MR) angiography. To isolate such cases, we retrospectively reviewed cranial MR angiographic images of 3,491 consecutive patients in our institution. We found three cases with carotid-anterior cerebral artery anastomosis (two men, one woman), representing an incidence of 0.086%. The anastomosis was on the right in all three cases. A normal A1 segment of the anterior cerebral artery (ACA) was present in two cases but could not be identified in the remaining case on MR angiographic images that included source images. Two of the three patients demonstrated associated arterial variations in their carotid systems. On MR angiography, we observed a 0.086% incidence of carotid-anterior cerebral artery anastomosis in our institution and reaffirmed the right-side predominance of this anomaly. We found a high frequency of other associated arterial variations in the carotid system. (orig.)

  2. The side-to-side fashion for individual distal coronary anastomosis using venous conduit. (United States)

    Kato, Takayoshi; Tsunekawa, Tomohiro; Motoji, Yusuke; Hirakawa, Akihiro; Okawa, Yasuhide; Tomita, Shinji


    Regarding to coronary artery bypass grafting (CABG), the end-to-side anastomosis (ESA) has been performed as a gold standard. Recently, the effectiveness of the distal side-to-side anastomosis (SSA) in CABG using internal mammary artery has been reported. The benefit of SSA comparing to ESA also has been disclosed by computing simulation. However, use of SSA by venous conduit for individual CABG has not been reported. In this study, we investigated feasibility of SSA. From January 2013 to October 2014, we conducted 114 CABGs. There were 92 venous distal anastomoses without sequential anastomotic site (61 SSA and 31 ESA). The anastomosis was evaluated before discharge and at 1 year after the procedure by angiography or multi-detector row computed tomographic coronary angiography. The median values for time to anastomosis were 13 min in the two group (p = 0.89). There was no revision of anastomosis in both groups. Additional stitches for hemostasis were required significantly less in SSA than ESA (18.0 vs 45.2 %, respectively, p fashion is easy to perform and maybe beneficial in blood flow pattern.

  3. Significance and specificity of vascular anastomosis in liver transplantation: Our experience

    Directory of Open Access Journals (Sweden)

    Nenezić Dragoslav


    Full Text Available Introduction Transplantation is the method of choice in the treatment of terminal liver diseases with acute and structural damage of liver tissue and congenital liver diseases. Objective The aim of our study was to determine specificity and significance of vascular anastomosis in liver transplantation by postoperative evaluation of vascular anastomosis function. Method The study included 16 patients with 16 liver transplantations and one re-do liver transplantation. In all patients, preoperative angiography and postoperative duplex sonographic and angiographic evaluation of vascular anastomosis were performed. Results Preoperative angiographic evaluation did not reveal anomalies in liver blood vessels of transplant candidates. In one patient, we identified and angiographically confirmed stenosis on anastomosis of the hepatic artery on the 7th postoperative day. In another patient, we had artificial thrombosis of the hepatic artery branch due to the liver biopsy. Conclusion The successful performance of vascular anastomosis in liver transplantation is significant for adequate liver graft perfusion, good postoperative graft function and overall outcome of the liver transplantation.

  4. Periventricular anastomosis in moyamoya disease: detecting fragile collateral vessels with MR angiography. (United States)

    Funaki, Takeshi; Takahashi, Jun C; Yoshida, Kazumichi; Takagi, Yasushi; Fushimi, Yasutaka; Kikuchi, Takayuki; Mineharu, Yohei; Okada, Tomohisa; Morimoto, Takaaki; Miyamoto, Susumu


    OBJECT The authors' aim in this paper was to determine whether periventricular anastomosis, a novel term for the abnormal collateral vessels typical of moyamoya disease, is reliably measured with MR angiography and is associated with intracranial hemorrhage. METHODS This cross-sectional study sampled consecutive patients with moyamoya disease or moyamoya syndrome at a single institution. Periventricular anastomoses were detected using MR angiography images reformatted as sliding-thin-slab maximum-intensity-projection coronal images and were scored according to 3 subtypes: lenticulostriate, thalamic, and choroidal types. The association between periventricular anastomosis and hemorrhagic presentation at onset was evaluated using multivariate analyses. RESULTS Of 136 eligible patients, 122 were analyzed. Eighteen (14.8%) patients presented with intracranial hemorrhage with neurological symptoms at onset. Intra- and interrater agreement for rating of the periventricular anastomosis score was good (κw = 0.65 and 0.70, respectively). The prevalence of hemorrhagic presentation increased with the periventricular anastomosis score: 2.8% for Score 0, 8.8% for Score 1, 18.9% for Score 2, and 46.7% for Score 3 (p moyamoya disease. The clinical utility of periventricular anastomosis as a predictor for hemorrhage should be validated in further prospective studies.

  5. Anastomosis coronaria. Técnica quirúrgica. Endarterectomía coronaria

    Directory of Open Access Journals (Sweden)

    Juan José Legarra


    Full Text Available La técnica quirúrgica para la realización de las anastomosis coronarias engloba desde la propia estrategia preoperatoria de revascularización al hecho técnico quirúrgico de la anastomosis. Los pasos importantes a destacar son la localización de los lechos coronarios, la preparación de los mismos, la arteriotomía y la sutura del injerto o anastomosis. Es crucial la comprobación del resultado funcional de las anastomosis con un medidor de flujo coronario. Estos aspectos son comunes a la circulación extracorpórea o con el corazón latiendo, para realizar la revascularización miocárdica. La cirugía coronaria moderna apuesta por una mayor utilización de injertos arteriales, basada fundamentalmente en las dos arterias mamarias esqueletizadas, empleando injertos compuestos o no, y con varias anastomosis secuenciales. La endarterectomía coronaria, técnica poco empleada en la actualidad, es un recurso que permite revascularizar territorios miocárdicos, en determinados pacientes con aterosclerosis coronaria generalizada grave.

  6. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice


    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  7. The effect of lymphatico-venous anastomosis for an intractable ulcer at the lower leg in a marked obese patient. (United States)

    Mihara, Makoto; Hara, Hisako; Todokoro, Takeshi; Seki, Yukio; Iida, Takuya; Koshima, Isao; Murai, Noriyuki


    Secondary lymphedema occurs after trauma, cancer surgery, or obesity, and wounds in lymphedema can easily become intractable. We report positive results using lymphatico-venous anastomosis (LVA) to treat a post-traumatic lymph fistula and an intractable ulcer in a severely obese patient. A 41-year-old male (BMI 51.8), one year prior, had a traffic injury, and had an 18-cm contusion in his right leg. Six months later, lymph leakage in a 14 cm × 8 cm region and a 5 cm × 3 cm skin ulcer occurred in the center of the wound. We made a diagnosis of lymphedema resulting from obesity, accompanied with lymphorrhea and intractable ulcer. He was unable to reach his legs owing to obesity, making complex physical therapy impossible. We performed LVA under local anesthesia. The lymphorrhea healed 2 weeks after the operation and had not recurred 3 months after the operation. The leg lymphedema improved after the surgery without the compression therapy. In cases of intractable ulcers, suspected of being caused by lymphostasis, treatments indicated for lymphedema, for example LVA, may possibly allow satisfactory wound healing. © 2013 Wiley Periodicals, Inc. Microsurgery 34:64-67, 2014. © 2013 The Authors. Microsurgery Published by Wiley Periodicals, Inc.

  8. Elastic ring deformation and pedestal contact status analysis of elastic ring squeeze film damper (United States)

    Zhang, Wei; Ding, Qian


    This paper investigates the dynamic parametric characteristic of the elastic ring squeeze film damper (ERSFD). Firstly, the coupled oil film Reynolds equations and dynamic equations of an ERSFD supported rotor system are established. The finite differential method and numerical simulation are used to analyze the oil film pressure distribution, bearing capacity of ERSFD, oil film stiffness and damping characteristics during a vibration period. Then, based on the oil film pressure results, the deformation of elastic ring is revealed by the finite element method. Finally, pedestal contact status is analyzed according to the change of oil film thickness during a vibration period. The results reveal that the oil film pressure is sectionally continuous, the deformation of elastic ring is complex under the compression of inner and outer oil film, and different pedestal contacts occur in a vibration period. The level of nonlinearity of the bearing capacity, oil film stiffness and damping can be effectively lightened by application of the elastic ring.

  9. Colectomy and ileorectal anastomosis is still an option for selected patients with familial adenomatous polyposis

    DEFF Research Database (Denmark)

    Bülow, Steffen; Bulow, C.; Vasen, H.


    PURPOSE: The risk of rectal cancer after colectomy and ileorectal anastomosis may be reduced in the last decades, as patients with severe polyposis now have an ileoanal pouch. We have reevaluated the risk of rectal cancer and proctectomy for all causes according to the year of operation. METHODS......: On the basis of the year of operation in 776 patients with ileorectal anastomosis and 471 pouch patients in Denmark, Finland, Holland, and Sweden, the "pouch period" was defined to start in 1990. Ileorectal anastomosis follow-up data was captured by May 31, 2006. The cumulative risk of rectal cancer...... and proctectomy was compared before and after 1990 by Kaplan-Meier analysis. RESULTS: In the prepouch period 56/576 patients (10 percent) developed rectal cancer, vs. 4/200 (2 percent) in the pouch period. Neither the cumulative risk of rectal cancer (p = 0.07) nor the cumulative risk of proctectomy (p = 0...

  10. Totally stapled gastrojejunal anastomosis using hybrid NOTES: single 12-mm trocar approach in a porcine model. (United States)

    Polese, Lino; Merigliano, Stefano; Mungo, Benedetto; Rizzato, Roberto; Luisetto, Roberto; Ancona, Ermanno; Norberto, Lorenzo


    The aim of this study was to evaluate the feasibility of a totally stapled gastrojejunal anastomosis performed using one transabdominal 12-mm trocar and a gastroscope in a porcine model. The procedure was carried out on six domestic pigs weighing 45 kg using a hybrid technique with a gastroscope and a 12-mm Hasson trocar, positioned in the left hypochondrium. At the end of the procedure a mechanical circular 21-mm gastrojejunal anastomosis was performed by inserting the stapler through a small gastrotomy after enlarging the trocar incision. In all six cases the procedure was completed through a single 3 cm abdominal incision and without complications. The mean operating time was 2 h, and endoscopic investigation showed that the anastomoses were intact, patent, and airtight. Totally stapled gastrojejunal anastomosis using a hybrid NOTES-single 12-mm trocar approach is a feasible procedure in the porcine model. Further survival studies are warranted, particularly to evaluate the functional results of this procedure.

  11. Fluorescent Angiography Used to Evaluate the Perfusion Status of Anastomosis in Laparoscopic Anterior Resection. (United States)

    Koh, Frederick H; Tan, Ker-Kan


    Anastomotic leakage after gastrointestinal surgery is associated with significant morbidity and mortality.1 Insufficient vascular supply is one cause.2 Recent reports of using intraoperative indocyanine green (ICG) fluorescent angiography to evaluate whether perfusion of the anastomosis is adequate has yielded positive outcomes.3 (-) 6 The authors describe their use of ICG-enhanced fluorescence angiography in a laparoscopic anterior resection. The patient was an 80-year-old with an upper rectal adenocarcinoma and significant cardiovascular risk factors. Fluorescence angiography with 0.4 mg/kg of ICG was administered intravenously just before the colorectal anastomosis was fashioned. A near-infrared (NIR) laparoscopic camera (KARLSTORZ, GmbH & Co. KG, Tuttlingen, Germany) was used to inspect the anastomosis. For this video, 0.4 mg/kg of ICG also was injected after ligation of the inferior mesenteric artery to demonstrate the appearance of a poorly perfused sigmoid bowel. Just before the staple was fired to fashion the colorectal anastomosis, an intravenous bolus of ICG was administered. Within seconds, vessels on both ends of the anastomosis turned fluorescent blue, indicating adequacy of perfusion. The use of ICG did not significantly lengthen the operative time (285 min) because its effect appeared within seconds after its administration. The patient recovered well and was discharged on postoperative day 5. Another four patients who also underwent intraoperative fluorescent angiography for left-sided colorectal lesions did not experience anastomotic leakage. The study showed that ICG fluorescent angiography is a simple and quick intraoperative tool for evaluating the perfusion of the anastomosis. The authors' experience with ICG fluorescent angiography has shown promising results, with a 0 % anastomotic leak rate.

  12. The learning rate in three dimensional high definition video assisted microvascular anastomosis in a rat model. (United States)

    Kotsougiani, Dimitra; Hundepool, Caroline A; Bulstra, Liselotte F; Shin, Delaney M; Shin, Alexander Y; Bishop, Allen T


    Three-dimensional (3D) high definition (HD) video systems are changing microsurgical practice by providing stereoscopic imaging not only for the surgeon and first assistant using the binocular microscope, but also for others involved in the surgery. The purpose of this study was to evaluate the potential to replace the binocular microscope for microarterial anastomoses and assess the rate of learning based on surgeons' experience. Two experienced and two novice microsurgeons performed a total of 88 rat femoral arterial anastomoses: 44 using a 3D HD video device ('Trenion', Carl Zeiss Meditech) and 44, a binocular microscope. We evaluated anastomosis time and modified OSATS scores as well as the subjects' preference for comfort, image adequacy and technical ease. Experienced microsurgeons showed a steep learning curve for anastomosis times with equivalent OSATS scores for both systems. However, prolonged anastomosis times were required when using the novel 3D-HD system rather than direct binocular vision. Comparable learning rates for anastomosis time were demonstrated for novice microsurgeons and modified OSATS scores did not differ between the different viewing technologies. All microsurgeons reported improved comfort for the 3D HD video system but found the image quality of the conventional microscope superior, facilitating technical ease. The present study demonstrates the potential of 3D HD video systems to replace current binocular microscopes, offering qualitatively-equivalent microvascular anastomosis with improved comfort for experienced microsurgeons. However, image quality was rated inferior with the 3D HD system resulting in prolonged anastomosis times. Microsurgical skill acquisition in novice microsurgeons was not influenced by the viewing system used. Copyright © 2016. Published by Elsevier Ltd.

  13. Tubal anastomosis after previous sterilization: a systematic review. (United States)

    van Seeters, Jacoba A H; Chua, Su Jen; Mol, Ben W J; Koks, Carolien A M


    chance of conception was female age. The surgical approach (i.e. laparotomy [microscopic], laparoscopy or robotic) had no impact on the outcome, with the exception of the macroscopic laparotomic technique, which had inferior results and is not currently utilized. For older women, IVF could be a more cost-effective alternative for the reversal of sterilization. However, direct comparative data are lacking and a cut-off age cannot be stated. In sterilized women who suffer regret, surgical tubal re-anastomosis is an effective treatment, especially in younger women. However, there is a need for randomized controlled trials comparing the success rates and costs of surgical reversal with IVF.

  14. Relationship between method of anastomosis and anastomotic failure after right hemicolectomy and ileo-caecal resection: an international snapshot audit

    NARCIS (Netherlands)

    Pinkney, T.; Battersby, N.; Bhangu, A.; Chaudhri, S.; El-Hussuna, A.; Frasson, M.; Nepogodiev, D.; Singh, B.; Vennix, S.; Zmora, O.; Altomare, D.; Bemelman, W.; Christensen, P.; D'Hoore, A.; Laurberg, S.; Morton, D.; Rubbini, M.; Vaizey, C.; Magill, L.; Perry, R.; Sheward, N.; Ives, N.; Mehta, S.; Cillo, M.; Estefania, D.; Patron Uriburu, J.; Ruiz, H.; Salomon, M.; Makhmudov, A.; Selnyahina, L.; Varabei, A.; Vizhynis, Y.; Claeys, D.; Defoort, B.; Muysoms, F.; Pletinckx, P.; Vergucht, V.; Debergh, I.; Feryn, T.; Reusens, H.; Nachtergaele, M.; Francart, D.; Jehaes, C.; Markiewicz, S.; Monami, B.; Weerts, J.; Bouckaert, W.; Houben, B.; Knol, J.; Sergeant, G.; Vangertruyden, G.; Haeck, L.; Lange, C.; Sommeling, C.; Vindevoghel, K.; Castro, S.; de Bruyn, H.; Huyghe, M.; de Wolf, E.; Reynders, D.; van Overstraeten, A. de Buck; Wolthuis, A.; Delibegovic, S.; Christiani, A.; Marchiori, M.; Rocha de Moraes, C.; Tercioti, V.; Arabadjieva, E.; Bulanov, D.; Dardanov, D.; Stoyanov, V.; Yonkov, A.; Angelov, K.; Maslyankov, S.; Sokolov, M.; Todorov, G.; Toshev, S.; Georgiev, Y.; Karashmalakov, A.; Zafirov, G.; Wang, X.; Condic, D.; Kraljik, D.; Mrkovic, H.; Pavkovic, V.; Raguz, K.; Bencurik, V.; Holaskova, E.; Skrovina, M.; Farkasova, M.; Grolich, T.; Kala, Z.; Antos, F.; Pruchova, V.; Sotona, O.; Chobola, M.; Dusek, T.; Ferko, A.; Orhalmi, J.; Hoch, J.; Kocian, P.; Martinek, L.; Bernstein, I.; Sunesen, K. Gotschalck; Leunbach, J.; Thorlacius-Ussing, O.; Oveson, A. Uth; Chirstensen, S. Dahl; Gamez, V.; Oeting, M.; Loeve, U. Schou; Ugianskis, A.; Jessen, M.; Krarup, P.; Linde, K.; Mirza, Q.; Stovring, J. Overgaard; Erritzoe, L.; Jakobsen, H. Loft; Lykke, J.; Colov, E. Palmgren; Madsen, A. Husted; Friis, T. Linde; Funder, J. Amstrup; Dich, R.; Kjaer, S.; Rasmussen, S.; Schlesinger, N.; Kjaer, M. Dilling; Qvist, N.; Khalid, A.; Ali, G.; Hadi, S.; Walker, L. Rosell; Kivela, A.; Lehtonen, T.; Lepisto, A.; Scheinin, T.; Siironen, P.; Kossi, J.; Kuusanmaki, P.; Tomminen, T.; Turunen, A.; Rautio, T.; Vierimaa, M.; Huhtinen, H.; Karvonen, J.; Lavonius, M.; Rantala, A.; Varpe, P.; Cotte, E.; Francois, Y.; Glehen, O.; Kepenekian, V.; Passot, G.; Maggiori, L.; Manceau, G.; Panis, Y.; Gout, M.; Rullier, E.; van Geluwe, B.; Chafai, N.; Lefevre, J. H.; Parc, Y.; Tiret, E.; Couette, C.; Duchalais, E.; Agha, A.; Hornberger, M.; Hungbauer, A.; Iesalnieks, I.; Weindl, I.; Crescenti, F.; Keller, M.; Kolodziejski, N.; Scherer, R.; Sterzing, D.; Bock, B.; Boehm, G.; El-Magd, M.; Krones, C.; Niewiera, M.; Buhr, J.; Cordesmeyer, S.; Hoffmann, M.; Krueckemeier, K.; Vogel, T.; Schoen, M.; Baral, J.; Lukoschek, T.; Muench, S.; Pullig, F.; Horisberger, K.; Kienle, P.; Magdeburg, J.; Post, S.; Batzalexis, K.; Germanos, S.; Agalianos, C.; Dervenis, C.; Gouvas, N.; Kanavidis, P.; Kottikias, A.; Katsoulis, I. E.; Korkolis, D.; Plataniotis, G.; Sakorafas, G.; Akrida, I.; Argentou, M.; Kollatos, C.; Lampropoulos, C.; Tsochatzis, S.; Besznyak, I.; Bursics, A.; Egyed, T.; Papp, G.; Svastics, I.; Atladottir, J.; Moller, P.; Sigurdsson, H.; Stefansson, T.; Valsdottir, E.; Andrews, E.; Foley, N.; Hechtl, D.; Majeed, M.; McCourt, M.; Hanly, A.; Hyland, J.; Martin, S.; O'Connell, P. R.; Winter, D.; Connelly, T.; Joyce, W.; Wrafter, P.; Berkovitz, R.; Avital, S.; Yahia, I. Haj; Hermann, N.; Shpitz, B.; White, I.; Lishtzinsky, Y.; Tsherniak, A.; Wasserberg, N.; Horesh, N.; Keler, U.; Pery, R.; Shapiro, R.; Tulchinsky, H.; Badran, B.; Dayan, K.; Iskhakov, A.; Lecaros, J.; Nabih, N.; Angrima, I.; Bardini, R.; Pizzolato, E.; Tonello, M.; Arces, F.; Balestri, R.; Ceccarelli, C.; Prosperi, V.; Rossi, E.; Giannini, I.; Vincenti, L.; Altomare, D. F.; Di Candido, F.; Di Iena, M.; Guglielmi, A.; Caputi-Iam-Brenghi, O.; Marsanic, P.; Mellano, A.; Muratore, A.; Annecchiarico, M.; Bencini, L.; Bona-Pasta, S. Amore; Coratti, A.; Guerra, F.; Asteria, C. R.; Boccia, L.; Gerard, L.; Pascariello, A.; Manca, G.; Marino, F.; Casaril, A.; Inama, M.; Moretto, G.; Bacchelli, C.; Carvello, M.; Mariani, N.; Montorsi, M.; Spinelli, A.; Romairone, E.; Scabini, S.; Belli, A.; Bianco, F.; de Franciscis, S.; Romano, G. Maria; Delrio, P.; Pace, U.; Rega, D.; Sassaroli, C.; Scala, D.; de Luca, R.; Ruggieri, E.; Elbetti, C.; Garzi, A.; Romoli, L.; Scatizzi, M.; Vannucchi, A.; Curletti, G.; Durante, V.; Galleano, R.; Mariani, F.; Reggiani, L.; Bellomo, R.; Infantino, A.; Franceschilli, L.; Sileri, P.; Clementi, I.; Coletta, D.; La Torre, F.; Mingoli, A.; Velluti, F.; Di Giacomo, A.; Fiorot, A.; Massani, M.; Padoan, L.; Ruffolo, C.; Caruso, S.; Franceschini, F.; Laessig, R.; Monaci, I.; Rontini, M.; de Nardi, P.; Elmore, U.; Lemma, M.; Rosati, R.; Tamburini, A.; de Luca, M.; Sartori, A.; Benevento, A.; Bottini, C.; Ferrari, C. C.; Pata, F.; Tessera, G.; Pellino, G.; Selvaggi, F.; Lanzani, A.; Romano, F.; Sgroi, G.; Steccanella, F.; Turati, L.; Yamamoto, T.; Ancans, G.; Gerkis, S.; Leja, M.; Pcolkins, A.; Sivins, A.; Latkauskas, T.; Lizdenis, P.; Saladzin-Skas, Z.; Svagzdys, S.; Tamelis, A.; Razbadauskas, A.; Sokolovas, M.; Dulskas, A.; Samalavicius, N.; Jotautas, V.; Mikalauskas, S.; Poskus, E.; Poskus, T.; Strupas, K.; Camenzuli, C.; Cini, C.; Predrag, A.; Psaila, J.; Spiteri, N.; Buskens, C.; de Groof, E. J.; Gooszen, J.; Tanis, P.; Belgers, E.; Davids, P.; Furnee, E.; Postma, E.; Pronk, A.; Smakman, N.; Clermonts, S.; Zimmerman, D.; Omloo, J.; van der Zaag, E.; van Duijvendijk, P.; Wassenaar, E.; Bruijninckx, M.; de Graff, E.; Doornebosch, P.; Tetteroo, G.; Vermaas, M.; Iordens, G.; Knops, S.; Toorenvliet, B.; van Westereenen, H. L.; Boerma, E.; Coene, P.; van der Harst, E.; van der Pool, A.; Raber, M.; Melenhorst, J.; de Castro, S.; Gerhards, M.; Arron, M.; Bremers, A.; de Wilt, H.; Ferenschild, F.; Yauw, S.; Cense, H.; Demirkiran, A.; Hunfeld, M.; Mulder, I.; Nonner, J.; Swank, H.; van Wagensveld, B.; Bolmers, M.; Briel, J.; van Geloven, A.; van Rossem, C.; Klemann, V.; Konsten, J.; Leenders, B.; Schok, T.; Bleeker, W.; Brun, M.; Helgeland, M.; Ignjatovic, D.; Oresland, T.; Yousefi, P.; Backe, I. Faten; Sjo, O. Helmer; Nesbakken, A.; Tandberg-Eriksen, M.; Cais, A.; Traeland, J. Hallvard; Herikstad, R.; Korner, H.; Lauvland, N.; Jajtner, D.; Kabiesz, W.; Rak, M.; Gmerek, L.; Horbacka, K.; Horst, N.; Krokowicz, P.; Kwiatkowski, A.; Pasnik, K.; Karcz, P.; Romaniszyn, M.; Rusek, T.; Walega, P.; Czarencki, R.; Obuszko, Z.; Sitarska, M.; Wojciech, W.; Zawadzki, M.; Amado, S.; Clara, P.; Couceiro, A.; Malaquias, R.; Rama, N.; Almeida, A.; Barbosa, E.; Cernadas, E.; Duarte, A.; Silva, P.; Costa, S.; Martinez Insua, C.; Pereira, J.; Pereira, C.; Sacchetti, M.; Carvalho Pinto, B.; Vieira Sousa, P. Jorge; Marques, R.; Oliveira, A.; Cardoso, R.; Carlos, S.; Corte-Real, J.; Moniz Pereira, P.; Souto, R.; Carneiro, C.; Marinho, R.; Nunes, V.; Rocha, R.; Sousa, M.; Leite, J.; Melo, F.; Pimentel, J.; Ventura, L.; Vila Nova, C.; Copacscu, C.; Bintintan, V.; Ciuce, C.; Dindelegan, G.; Scurtu, R.; Seicean, R.; Domansky, N.; Karachun, A.; Moiseenko, A.; Pelipas, Y.; Petrov, A.; Pravosudov, I.; Aiupov, R.; Akmalov, Y.; Parfenov, A.; Suleymanov, N.; Tarasov, N.; Jumabaev, H.; Mamedli, Z.; Rasulov, A.; Aliev, I.; Chernikovskiy, I.; Kochnev, V.; Komyak, K.; Smirnov, A.; Achkasov, S.; Bolikhov, K.; Shelygin, Y.; Sushkov, O.; Zapolskiy, A.; Gvozdenovic, M.; Jovanovic, D.; Lausevic, Z.; Cvetkovic, D.; Maravic, M.; Milovanovic, B.; Stojakovic, N.; Tripkovic, I.; Mihajlovic, D.; Nestorovic, M.; Pecic, V.; Petrovic, D.; Stanojevic, G.; Barisic, G.; Dimitrijevic, I.; Krivokapic, Z.; Markovic, V.; Popovic, M.; Aleksic, A.; Dabic, D.; Kostic, I.; Milojkovic, A.; Perunicic, V.; Lukic, D.; Petrovic, T.; Radovanovic, D.; Radovanovic, Z.; Cuk, V. M.; Cuk, V. V.; Kenic, M.; Kovacevic, B.; Krdzic, I.; Korcek, J.; Rems, M.; Toplak, J.; Escarra, J.; Gil Barrionuevo, M.; Golda, T.; Kreisler Moreno, E.; Zerpa Martin, C.; Alvarez Laso, C.; Cumplido, P.; Padin, H.; Baixauli Fons, J.; Hernandez-Lizoain, J.; Martinez-Ortega, P.; Molina-Fernandez, M.; Sanchez-Justicia, C.; Gracia Solanas, J. Antonio; Diaz de laspra, E. Cordoba; Echazarreta-Gallego, E.; Elia-Guedea, M.; Ramirez, J.; Arredondo Chaves, J.; Gonzalez, P. Diez; Elosua, T.; Sahagun, J.; Turienzo Frade, A.; Alvarez Conde, J.; Castrillo, E.; Diaz Maag, R.; Maderuelo, V.; Saldarriaga, L.; Aldrey Cao, I.; Fernandez Varela, X.; Nunez Fernandez, S.; Parajo Calvo, A.; Villar Alvarez, S.; Blesa Sierra, I.; Lozano, R.; Marquez, M.; Porcel, O.; Menendez, P.; Fernandez Hevia, M.; Flores Siguenza, L.; Jimenez Toscano, M.; Lacy Fortuny, A.; Ordonez Trujillo, J.; Espi, A.; Garcia-Botello, S.; Martin-Arevalo, J.; Moro-Valdezate, D.; Pla-Marti, V.; Blanco-Antona, F.; Abrisqueta, J.; Ibanez Canovas, N.; Lujan Mompean, J.; Escola Ripoll, D.; Martinez Gonzalez, S.; Parodi, J.; Fernandez Lopez, A.; Ramos Fernandez, M.; Castellvi Valls, J.; Ortiz de Zarate, L.; Ribas, R.; Sabia, D.; Viso, L.; Alonso Goncalves, S.; Gil Egea, M. Jose; Pascual Damieta, M.; Pera, M.; Salvans Ruiz, S.; Bernal, J.; Landete, F.; Ais, G.; Etreros, J.; Aguilo Lucia, J.; Bosca, A.; Deusa, S.; Garcia del Cano, J.; Viciano, V.; Garcia-Armengol, J.; Roig, J.; Blas, J.; Escartin, J.; Fatas, J.; Fernando, J.; Ferrer, R.; Arias Pacheco, R.; Garcia Florez, L.; Moreno Gijon, M.; Otero Diez, J.; Solar Garcia, L.; Aguilar Teixido, F.; Balaguer Ojo, C.; Bargallo Berzosa, J.; Lamas Moure, S.; Sierra, J. Enrique; Ferminan, A.; Herrerias, F.; Rufas, M.; Vinas, J.; Codina-Cazador, A.; Farres, R.; Gomez, N.; Julia, D.; Planellas, P.; Lopez, J.; Luna, A.; Maristany, C.; Munoz Duyos, A.; Puertolas, N.; Alcantara Moral, M.; Serra-Aracil, X.; Concheiro Coello, P.; Gomez, D.; Carton, C.; Miguel, A.; Reoyo Pascual, F.; Valero Cerrato, X.; Zambrano Munoz, R.; Cervera-Aldama, J.; Gonzalez, J. Garcia; Ramos-Prada, J.; Santamaria-Olabarrieta, M.; Uriguen-Echeverria, A.; Coves Alcover, R.; Espinosa Soria, J.; Fernandez Rodriguez, E.; Hernandis Villalba, J.; Maturana Ibanenz, V.; de la Torre Gonzalez, F.; Huerga, D.; Perez Viejo, E.; Rivera, A.; Ruiz Ucar, E.; Garcia-Septiem, J.; Jimenez, V.; Jimenez Miramon, J.; Ramons Rodriquez, J.; Rodriguez Alvarez, V.; Garcea, A.; Ponchietti, L.; Borda, N.; Enriquez-Navascues, J.; Saralegui, Y.; Febles Molina, G.; Nogues, E.; Rodriguez Mendez, A.; Roque Castellano, C.; Sosa Quesada, Y.; Alvarez-Gallego, M.; Pascual, I.; Rubio-Perez, I.; Diaz-San Andres, B.; Tone-Villanueva, F.; Alonso, J.; Cagigas, C.; Castillo, J.; gomez, M.; Martin-Parra, J.; Mengual Ballester, M.; Pellicer Franco, E.; Soria Aledo, V.; Valero Navarro, G.; Caballero Rodriguez, E.; Gonzalez de Chaves, P.; Hernandez, G.; Perez Alvarez, A.; Soto Sanchez, A.; Becerra Garcia, F. Cesar; Alonso Roque, J. Guillermo; Rodriguez Arias, F. Lopez; del Valle Ruiz, S. R.; Sanchez de la Villa, G.; Compan, A.; Garcia Marin, A.; Nofuentes, C.; Orts Mico, F.; Perez Auladell, V.; Carrasco, M.; Duque Perez, C.; Galvez-Pastor, S.; Navarro Garcia, I.; Sanchez Perez, A.; Enjuto, D.; Manuel Bujalance, F.; Marcelin, N.; Perez, M.; Serrano Garcia, R.; Cabrera, A.; de la Portilla, F.; Diaz-Pavon, J.; Jimenez-Rodriguez, R.; Vazquez-Monchul, J.; Daza Gonzalez, J.; Gomez Perez, R.; Rivera Castellano, J.; Roldan de la Rua, J.; Errasti Alustiza, J.; Fernandez, L.; Romeo Ramirez, J.; Sardon Ramos, J.; Cermeno Toral, B.; Alias, D.; Garcia-Olmo, D.; Guadalajara, H.; Herreros, M.; Pacheco, P.; del Castillo Diez, F.; Lima Pinto, F.; Martinez Alegre, J.; Ortega, I.; Nieto Antonio, A. Picardo; Caro, A.; Escuder, J.; Feliu, F.; Millan, M.; Alos Company, R.; Frangi Caregnato, A.; Lozoya Trujillo, R.; Rodriguez Carrillo, R.; Ruiz Carmona, M.; Alonso, N.; Ambrona Zafra, D.; Ayala Candia, B. Amilka; Bonnin Pascual, J.; Pineno Flores, C.; Alcazar Montero, J.; Angoso Clavijo, M.; Garcia, J.; Sanchez Tocino, J.; Gomez-Alcazar, C.; Costa-Navarro, D.; Ferri-Romero, J.; Rey-Riveiro, M.; Romero-Simo, M.; Arencibia, B.; Esclapez, P.; Garcia-Granero, E.; Granero, P.; Medina Fernandez, F. J.; Gallardo Herrera, A. B.; Diaz Lopez, C.; Navarro Rodriguez, E.; Torres Tordera, E.; Arenal, J.; Citores, M.; Marcos, J.; Sanchez, J.; Tinoco, C.; Espin, E.; Garcia Granero, A.; Jimenez Gomez, L.; Sanchez Garcia, J.; Vallribera, F.; Folkesson, J.; Skoldberg, F.; Bergman, K.; Borgstrom, E.; Frey, J.; Silfverberg, A.; Soderholm, M.; Nygren, J.; Segelman, J.; Gustafsson, D.; Lagerqvist, A.; Papp, A.; Pelczar, M.; Abraham-Nordling, M.; Ahlberg, M.; Sjovall, A.; Tengstrom, J.; Hagman, K.; Chabok, A.; Ezra, E.; Nikberg, M.; Smedh, K.; Tiselius, C.; Al-Naimi, N.; Duc, M. Dao; Meyer, J.; Mormont, M.; Ris, F.; Prevost, G.; Villiger, P.; Hoffmann, H.; Kettelhack, C.; Kirchhoff, P.; Oertli, D.; Weixler, B.; Aytac, B.; Leventoglu, S.; Mentes, B.; Yuksel, O.; Demirbas, S.; Ozkan, B. Busra; Ozbalci, G. Selcuk; Sungurtekin, U.; Gulcu, B.; Ozturk, E.; Yilmazlar, T.; Challand, C.; Fearnhead, N.; Hubbard, R.; Kumar, S.; Arthur, J.; Barben, C.; Skaife, P.; Slawik, S.; Williams, M.; Zammit, M.; Barker, J.; French, J.; Sarantitis, I.; Slawinski, C.; Clifford, R.; Eardley, N.; Johnson, M.; McFaul, C.; Vimalachandran, D.; Allan, S.; Bell, A.; Oates, E.; Shanmugam, V.; Brigic, A.; Halls, M.; Pucher, P.; Stubbs, B.; Agarwal, T.; Chopada, A.; Mallappa, S.; Pathmarajah, M.; Sugden, C.; Brown, C.; Macdonald, E.; Mckay, A.; Richards, J.; Robertson, A.; Kaushal, M.; Patel, P.; Tezas, S.; Touqan, N.; Ayaani, S.; Marimuthu, K.; Piramanayagam, B.; Vourvachis, M.; Iqbal, N.; Korsgen, S.; Seretis, C.; Shariff, U.; Arnold, S.; Chan, H.; Clark, E.; Fernandes, R.; Moran, B.; Bajwa, A.; McArthur, D.; Cao, K.; Cunha, P.; Pardoe, H.; Quddus, A.; Theodoropoulou, K.; Bolln, C.; Denys, G.; Gillespie, M.; Manimaran, N.; Reidy, J.; Malik, A. I.; Malik, A.; Pitt, J.; Aryal, K.; El-Hadi, A.; Lal, R.; Pal, A.; Velchuru, V.; Cunha, M. Oliveira; Thomas, M.; Bains, S.; Boyle, K.; Miller, A.; Norwood, M.; Yeung, J.; Goian, L.; Gurjar, S.; Saghir, W.; Sengupta, N.; Stewart-Parker, E.; Bailey, S.; Khalil, T.; Lawes, D.; Nikolaou, S.; Omar, G.; Church, R.; Muthiah, B.; Garrett, W.; Marsh, P.; Obeid, N.; Chandler, S.; Coyne, P.; Evans, M.; Hunt, L.; Lim, J.; Oliphant, Z.; Papworth, E.; Weaver, H.; Leon, K. Cuinas; Williams, G.; Hernon, J.; Kapur, S.; Moosvi, R.; Shaikh, I.; Swafe, L.; Aslam, M.; Evans, J.; Ihedioha, U.; Kang, P.; Merchant, J.; Hompes, R.; Middleton, R.; Broomfield, A.; Crutten-Wood, D.; Foster, J.; Nash, G.; Akhtar, M.; Boshnaq, M.; Eldesouky, S.; Mangam, S.; Rabie, M.; Ahmed, J.; Khan, J.; Goh, N. Ming; Shamali, A.; Stefan, S.; Thompson, C.; Amin, A.; Docherty, J.; Lim, M.; Walker, K.; Watson, A.; Hossack, M.; Mackenzie, N.; Paraoan, M.; Alam, N.; Daniels, I.; Narang, S.; Pathak, S.; Smart, N.; Al-Qaddo, A.; Codd, R.; Rutka, O.; Bronder, C.; Crighton, I.; Davies, E.; Raymond, T.; Bookless, L.; Griffiths, B.; Plusa, S.; Carlson, G.; Harrison, R.; Lees, N.; Mason, C.; Quayle, J.; Branagan, G.; Broadhurst, J.; Chave, H.; Sleight, S.; Awad, F.; Cruickshank, N.; Joy, H.; Boereboom, C.; Daliya, P.; Dhillon, A.; Watson, N.; Watson, R.; Artioukh, D.; Gokul, K.; Javed, M.; Kong, R.; Sutton, J.; Faiz, O.; Jenkins, I.; Leo, C. A.; Samaranayake, S. F.; Warusavitarne, J.; Arya, S.; Bhan, C.; Mukhtar, H.; Oshowo, A.; Wilson, J.; Duff, S.; Fatayer, T.; Mbuvi, J.; Sharma, A.; Cornish, J.; Davies, L.; Harries, R.; Morris, C.; Torkington, J.; Knight, J.; Lai, C.; Shihab, O.; Tzivanakis, A.; Hussain, A.; Luke, D.; Padwick, R.; Torrance, A.; Tsiamis, A.; Dawson, P.; Balfour, A.; Brady, R.; Mander, J.; Paterson, H.; Chandratreya, N.; Chu, H.; Cutting, J.; Vernon, S.; Ho, C. Wai; Andreani, S.; Patel, H.; Warner, M.; Tan, J. Yan Qi; Gidwani, A.; Lawther, R.; Loughlin, P.; Skelly, B.; Spence, R.; Iqbal, A.; Khan, A.; Perrin, K.; Raza, A.; Tan, S.


    Aim The anastomosis technique used following right-sided colonic resection is widely variable and may affect patient outcome. This study aimed to assess the association between leak and anastomosis technique (stapled vs handsewn). Method This was a prospective, multicentre, international audit

  15. Outcome of 132 consecutive reconstructive operations for intestinal fistula--staged operation without primary anastomosis improved outcome in retrospective analysis

    DEFF Research Database (Denmark)

    Runström, B; Hallböök, O; Nyström, P O


    rate was lower after an operation with stoma without anastomosis (6 of 43, 14%) than after an operation with anastomosis (30 of 89, 34%) p = 0.0213. Of the 36 instances with unhealed fistula, 13 (36%) could be ascribed to inadvertent bowel lesions at the reconstructive operation. In addition...

  16. Physics of quantum rings

    CERN Document Server

    Fomin, Vladimir M


    This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is po

  17. Compression limits in cascaded quadratic soliton compression

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw


    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  18. Saturn's largest ring. (United States)

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P


    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

  19. Use of bioabsorbable staple reinforcement material in side-to-side anastomoses: Suture line reinforcement of the weak point of the anastomosis


    Kimura, Masahiro; Terashita, Yukio


    Background: Few studies have been designed regarding optimal reinforcement of the crotch of a side-to-side anastomosis. The purpose of this study was to clarify the weak point of the side-to-side anastomosis and to evaluate the effect of bioabsorbable reinforcement material. Methods: Fresh pig small bowel was used for all experiments. A side-to-side anastomosis was performed using a linear stapler, and the burst pressure of the anastomosis was measured. Three separate experiments were done...

  20. Higher magnification microsurgical repair of donor artery dissection in superficial temporal artery to middle cerebral artery anastomosis--technical note. (United States)

    Matsumura, Nobuhisa; Shibata, Takashi; Kamiyama, Hironaga; Tomita, Takahiro; Okamoto, Soushi; Kubo, Michiya; Horie, Yukio


    Donor artery dissection is a known cause of technical failure in microvascular anastomosis. A method for detection and direct repair of donor artery dissection before superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis is described using a high magnification operating microscope (maximum 50.4× magnification). Before STA-MCA anastomosis, the stump of the STA is stained using methylrosaniline chloride (pyoctaninum blue) and is observed under higher magnifications. Microsurgical suturing of the arterial dissection is performed before the anastomosis procedure under the high magnification microscope. This method was used in two patients with symptomatic hemodynamic cerebrovascular occlusive disease. Postoperative angiography revealed good patency and no complications occurred. This method may be useful for detection and direct repair of arterial dissection in small vessel walls before STA-MCA anastomosis.

  1. Eficacitatea combaterii larvelor de Clostera anastomosis L. la ieșirea din hibernare [Treatment efficacy of Clostera anastomosis L. caterpillars control in postdormancy phase


    Duduman Mihai-Leonard; Lupaștean Daniela; Pînzanu Ștefan Ionuț; Ilașcă Alexandra; Dănilă Iulian Constantin


    Clostera anastomosis is an important poplar and willow defoliator which, especially since 1950, caused important damages to intensive hybrid poplar crops in Europe and Asia. The need to reduce the loss caused by this insect, often led to radical control tactics, consisting in spraying chemical insecticides with low specificity and high impact on biodiversity. Other control methods (biological control) had not the expected effect. Considering the above mentioned aspects and t...

  2. Investigation of different piston ring curvatures on lubricant transport along cylinder liner in large two-stroke marine diesel engines

    DEFF Research Database (Denmark)

    Overgaard, H; Klit, P; Vølund, A


    A theoretical investigation of the hydrodynamic lubrication of the top compression piston ring in a large two-stroke marine diesel engine is presented. The groove mounted piston ring is driven by the reciprocal motion of the piston. The ring shape follows a circular geometry and the effect...

  3. Investigation of Different Piston Ring Curvatures on Lubricant Transport along Cylinder Liner in Large Two-Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Overgaard, Hannibal Christian; Klit, Peder; Vølund, Anders


    A theoretical investigation of the hydrodynamic lubrication of the top compression piston ring in a large two-stroke marine diesel engine is presented. The groove mounted piston ring is driven by the reciprocal motion of the piston. The ring shape follows a circular geometry and the effect...

  4. Adenocarcinoma in the anal canal after ileal pouch-anal anastomosis for familial adenomatous polyposis using a double-stapled technique: report of two cases

    NARCIS (Netherlands)

    Vrouenraets, Bart C.; van Duijvendijk, Peter; Bemelman, Willem A.; Offerhaus, G. Johan A.; Slors, J. Frederik M.


    Restorative proctocolectomy with an ileal pouch-anal anastomosis is thought to abolish the risk of colorectal adenoma development in patients suffering from familial adenomatous polyposis. Both after mucosectomy with a handsewn anastomosis and after a double-stapled anastomosis, rectal mucosa is

  5. Surgical outcomes in the newly introduced phase of intracorporeal anastomosis following laparoscopic distal gastrectomy is safe and feasible compared with established procedures of extracorporeal anastomosis. (United States)

    Kanaji, Shingo; Harada, Hitoshi; Nakayama, Shunji; Yasuda, Takashi; Oshikiri, Taro; Kawasaki, Kentaro; Yamamoto, Masashi; Imanishi, Tatsuya; Nakamura, Tetsu; Suzuki, Satoshi; Tanaka, Kenichi; Fujino, Yasuhiro; Tominaga, Masahiro; Kakeji, Yoshihiro


    Totally laparoscopic distal gastrectomy (TLDG) with intracorporeal anastomosis has been introduced to achieve safer anastomosis with good vision, and a small wound. However, little is known about the surgical outcomes of newly introduced TLDG compared with established procedures of laparoscopy-assisted gastrectomy (LADG) with extracorporeal anastomosis. This retrospective study included 114 patients who underwent laparoscopic distal gastrectomy (LDG) between January 2010 and September 2012. The patients were classified into two groups according to the approach of reconstruction (LADG group: n = 74; TLDG group: n = 40). The parameters analyzed included patients, operation details, and operative outcomes. No complication was observed in the TLDG group. Surgical outcomes of the TLDG group, such as mean operation time, estimated blood loss, and rate of conversion to laparotomy were not inferior to the LADG group. Furthermore, postoperative hospital stay of the TLDG group was significantly shorter than the LADG group (p Surgical outcomes in the newly introduced phase of TLDG were safe as well as feasible compared with established LADG. TLDG has several advantages over LADG, such as shorter post-hospital stay, no incidence of operative complication, adequate working space, and small wound size. Although prospective, randomized control studies are warranted, we submit that TLDG can be used as a standard procedure for LDG.

  6. Ring extension of entire ring with conjugation; arithmetic in entire rings


    Laugier, Alexandre


    Some basic properties of the ring of integers $\\mathbb{Z}$ are extended to entire rings. In particular, arithmetic in entire principal rings is very similar than arithmetic in the ring of integers $\\mathbb{Z}$. These arithmetic properties are derived from a $\\star$-ring extension of the considered entire ring (ring extension with conjugation) equipped with a real function which is a multiplicative structure-preserving map between two algebras. The algebra of this ring extension is studied in ...

  7. Particle Simulations of Ion Rings for Magnetic Fusion. (United States)

    Lyster, Peter Michael


    This thesis contains a numerical study of the dynamics of axis encircling charged particles in ion rings and layers. Part of this work deals with the coalescence of ion rings to form field reversed rings, which may be useful for Compact Torus magnetic fusion reactors. The coalescence of weak ion rings with Compact Toroids is also investigated. This is important because a component of energetic particles may help to maintain the flux or stabilize these configurations against a number of macroscopic magnetohydrodynamic instabilities. Several different types of particle codes are used. RINGA and CIDER are two and one half-dimensional codes in cylindrical axisymmetric geometry. For the RINGA code, a simple Ohm's law is used for modeling a resistive background plasma. For CIDER, the massless electron momentum equation is used for modeling a conductive background plasma. In a resistive plasma, ring coalescence can be achieved if the initial relative translational velocity is not excessive, and if the plasma conductivity is chosen to maximize the dissipation of ring energy. A theoretical and computational study is made of a mechanism by which ring translational energy is transferred to Alfven waves in a conductive plasma. A new collective phenomenon is discussed, whereby the merging of rings is improved if they have stronger initial self fields. A study is made of the coalescence of strong field-reversed ion rings in highly conductive plasmas, in which it is found that magnetic field line reconnection is an important process. Finally, a study of the magnetic compression of ion layers in conductive plasmas is presented. BAGSHAW, a one-dimensional particle code which treats the background plasma in the two fluid approximation, was developed for this purpose. Compression on a timescale which is comparable with the Alfven transit time may create considerable transients in the system. In a one-dimensional system, the plasma return current does not cancel the increase in the

  8. [Application of Halo-vest head ring in replantation of total scalp avulsion]. (United States)

    Jian, Lin; Lizhi, Wu; Yuhua, Guo; Tianhao, Zhang; Shilin, Gu; Cheng, Wang; Zhongyi, Chen; Haixiao, Chen


    To investigate the clinical effect of Halo-vest head ring in the treatment of replantation of total scalp avulsion. We treated 11 cases of total scalp avulsion with the anastomosis of arteriovenous vessels and Halo-vest head ring from December 2006 to February 2015. One patient's replanted scalp got necrosis because of serious contusion which was healed without hair growth after free skin graft and dressing. All the scalp flaps in the other 10 patients survived. After 3-96 months follow-up, the wound completely healed, the scalp and hair grew well with satisfactory appearance. The use of Halo-vest head ring for replantation of total scalp avulsion can effectively improve the survival rate and survival area.

  9. Heterogeneity in electrophoretic karyotype within and between anastomosis groups of Rhizoctonia solani

    NARCIS (Netherlands)

    Keijer, J.; Houterman, P.M.; Dullemans, A.M.; Korsman, M.G.


    Isolates of the soil borne basidiomycete Rhizoctonia solani vary in cultural appearance, in growth characteristics and in pathogenicity towards plants. Isolates of R. solani can be divided into anastomosis groups (AGs) and this division accommodates part of the observed diversity. However, a clear

  10. [Method of preventive maintenance of a leakage stitch of a small intestine anastomosis]. (United States)

    Agaev, E K


    Dynamic follow-up of 110 patients (main group) and retrospective analysis of 59 patients (control group) with widespread peritonitis and acute intestinal obstruction was performed to assess the efficacy of permanent intramesenteric blockade and limphotropic therapy in the prevention of intestinal anastomosis insufficiency. Frequency of anastomotic insufficiency decreased from 15.5 to 3.4% (χ2=16.2, pprevention.

  11. Early and late complications among long-term colorectal cancer survivors with ostomy or anastomosis. (United States)

    Liu, Liyan; Herrinton, Lisa J; Hornbrook, Mark C; Wendel, Christopher S; Grant, Marcia; Krouse, Robert S


    Among long-term (>or=5 y) colorectal cancer survivors with permanent ostomy or anastomosis, we compared the incidence of medical and surgical complications and examined the relationship of complications with health-related quality of life. The incidence and effects of complications on long-term health-related quality of life among colorectal cancer survivors are not adequately understood. Participants (284 survivors with ostomies and 395 survivors with anastomoses) were long-term colorectal cancer survivors enrolled in an integrated health plan. Health-related quality of life was assessed via mailed survey questionnaires from 2002 to 2005. Information on colorectal cancer, surgery, comorbidities, and complications was obtained from computerized data and analyzed by use of survival analysis and logistic regression. Ostomy and anastomosis survivors were followed up for an average of 12.1 and 11.2 years, respectively. Within 30 days of surgery, 19% of ostomy survivors and 10% of anastomosis survivors experienced complications (P Ostomy was associated with long-term fistula (odds ratio, 5.4; 95% CI 1.4-21.2), and among ostomy survivors, fistula was associated with reduced health-related quality of life (P ostomy have more complications early in their survivorship period, but complications among anastomosis survivors catch up after 20 years, when the 2 groups have convergent complication rates. Among colorectal cancer survivors with ostomy, fistula has especially important implications for health-related quality of life.

  12. Indications of a Defunctioning Stoma in Colorectal Anastomosis--Our Experience and Review of the Literature. (United States)

    Coroş, Marius F; Sorlea, Sorin; Hintea, Alexandru; Georgescu, Rareş; Crăciun, Călin; Pascarenco, Ghenadie


    Defunctioning stomas can prevent consequences of anastomotic leakage, but they are not free of complications. The identification of high-risk patients to establish criteria for strong and relative indications for the formation of a defunctioning stoma. Two hundred fifty consecutive colorectal anastomoses were performed between 2004 and 2015; 95.2% of these were for colorectal cancer. In 130 cases, mechanical anastomosis was used. A protective stoma was performed in only 15 cases. The incidence of anastomotic leakage was evaluated according to multiple parameters, as were the postoperative complications related to protective stomas. The outcomes were compared to those reported in the literature. Symptomatic anastomotic leakage occurred in six patients (2.4%) and resulted in four deaths. None of the patients with a protective stoma developed serious complications related to the colorectal anastomosis. However, serious ileostomy-related complications occurred in two cases (15.38%). Protective stomas should be used only according to the risk criteria of the patients. Strong indications are: anastomotic imperfections, anastomosis under tension, previous pelvic irradiation, ultralow anastomosis in patients older than 70 years, patients over 80 years, and significant co-morbidities. Celsius.

  13. When is primary anastomosis safe in the colon? | Ostrow | Annals of ...

    African Journals Online (AJOL)

    When is primary anastomosis safe in the colon? B Ostrow. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  14. [Restrictive artificial mechanisms in prevention of late complications after small intestine-colon anastomosis]. (United States)

    Baulin, A A


    The experiments on 30 dogs proved that reduplication and semi-invagination serve as restrictive mechanisms before small intestine-colon anastomosis. These procedures slow dowm the evacuation of intestinal contents, interfere with small intestine-colonic outflow, improve digestion and absorption, contribute to the shortening of the time needed for compensation, provide better late results of the right hemicolonectomy.

  15. Cardiovascular Surgery Residency Program: Training Coronary Anastomosis Using the Arroyo Simulator and UNIFESP Models

    Directory of Open Access Journals (Sweden)

    Miguel Angel Maluf


    Full Text Available ABSTRACT OBJECTIVE: Engage the UNIFESP Cardiovascular Surgery residents in coronary anastomosis, assess their skills and certify results, using the Arroyo Anastomosis Simulator and UNIFESP surgical models. METHODS: First to 6th year residents attended a weekly program of technical training in coronary anastomosis, using 4 simulation models: 1. Arroyo simulator; 2. Dummy with a plastic heart; 3. Dummy with a bovine heart; and 4. Dummy with a beating pig heart. The assessment test was comprised of 10 items, using a scale from 1 to 5 points in each of them, creating a global score of 50 points maximum. RESULTS: The technical performance of the candidate showed improvement in all items, especially manual skill and technical progress, critical sense of the work performed, confidence in the procedure and reduction of the time needed to perform the anastomosis after 12 weeks practice. In response to the multiplicity of factors that currently influence the cardiovascular surgeon training, there have been combined efforts to reform the practices of surgical medical training. CONCLUSION: 1 - The four models of simulators offer a considerable contribution to the field of cardiovascular surgery, improving the skill and dexterity of the surgeon in training. 2 - Residents have shown interest in training and cooperate in the development of innovative procedures for surgical medical training in the art.

  16. Sources and severity of self-reported food intolerance after ileal pouch-anal anastomosis

    NARCIS (Netherlands)

    Steenhagen, E.; Roos, de N.M.; Bouwman, C.A.; Laarhoven, van C.J.H.M.; Staveren, van W.A.


    Data on food intolerance after ileal pouch-anal anastomosis are scarce. The aim of this study was to identify foods causing intolerance and to determine the nature and severity of reported symptoms. Patients from the Dutch Crohn's and Ulcerative Colitis Association were mailed a survey on food

  17. Review or recent EBT coupled ring-core stability theory (United States)

    Spong, D. A.


    During the past several years Elmo Bumpy Torus (EBT) stability calculations have evolved with respect to treatment of ring-core plasma coupling effects. This evolution began with recognition of the important role of ring compressibility and paramagnetic effects on core beta limits. Since then, models have continued to increase in sophistication, incuding ring-core frequency coupling, velocity space and hot electron distribution function effects, and radially dependent models. Some of these features resulted in wide variations in predicted plasma performance limitations. A number of the models are reviewed and assumptions to which they are particularly sensitive are discussed.

  18. Review of recent EBT coupled ring-core stability theory (United States)

    Spong, D. A.

    During the past several years Elmo Bumpy Torus (EBT) stability calculations evolved with respect to treatment of ring-core plasma coupling effects. This evolution began with recognition of the important role of ring compressibility and paramagnetic effects on core beta limits. Models continued to increase in sophistication, including ring-core freqency coupling, velocity space and hot electron distribution function effects, and radically dependent models. Some of these features resulted in wide variations in predicted plasma performance limitations. A number of the models were reviewed and assumptions to which they are particularly sensitive are discussed.

  19. Review of recent EBT coupled ring-core stability theory

    Energy Technology Data Exchange (ETDEWEB)

    Spong, D.A.


    During the past several years Elmo Bumpy Torus (EBT) stability calculations have evolved with respect to treatment of ring-core plasma coupling effects. This evolution began with recognition of the important role of ring compressibility and paramagnetic effects on core beta limits. Since then, models have continued to increase in sophistication, including ring-core frequency coupling, velocity space and hot electron distribution function effects, and radially dependent models. Some of these features have resulted in wide variations in predicted plasma performance limitations. A number of the models will be reviewed and assumptions to which they are particularly sensitive will be discussed.

  20. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu


    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  1. The Vibration Ring. Phase 1; [Seedling Fund (United States)

    Asnani, Vivake M.; Krantz, Timothy L.; Delap, Damon C.; Stringer, David B.


    The vibration ring was conceived as a driveline damping device to prevent structure-borne noise in machines. It has the appearance of a metal ring, and can be installed between any two driveline components like an ordinary mechanical spacer. Damping is achieved using a ring-shaped piezoelectric stack that is poled in the axial direction and connected to an electrical shunt circuit. Surrounding the stack is a metal structure, called the compression cage, which squeezes the stack along its poled axis when excited by radial driveline forces. The stack in turn generates electrical energy, which is either dissipated or harvested using the shunt circuit. Removing energy from the system creates a net damping effect. The vibration ring is much stiffer than traditional damping devices, which allows it to be used in a driveline without disrupting normal operation. In phase 1 of this NASA Seedling Fund project, a combination of design and analysis was used to examine the feasibility of this concept. Several designs were evaluated using solid modeling, finite element analysis, and by creating prototype hardware. Then an analytical model representing the coupled electromechanical response was formulated in closed form. The model was exercised parametrically to examine the stiffness and loss factor spectra of the vibration ring, as well as simulate its damping effect in the context of a simplified driveline model. The results of this work showed that this is a viable mechanism for driveline damping, and provided several lessons for continued development.

  2. Token ring technology report

    CERN Document Server


    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  3. Ordered Rings and Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph


    Full Text Available We introduce ordered rings and fields following Artin-Schreier’s approach using positive cones. We show that such orderings coincide with total order relations and give examples of ordered (and non ordered rings and fields. In particular we show that polynomial rings can be ordered in (at least two different ways [8, 5, 4, 9]. This is the continuation of the development of algebraic hierarchy in Mizar [2, 3].

  4. Radioactive gold ring dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.A.; Aldrich, J.E. (Dalhousie Univ., Halifax, Nova Scotia (Canada))


    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  5. Suture Line Response of End-to-Side Anastomosis: A Stress Concentration Methodology. (United States)

    Roussis, P C; Giannakopoulos, A E; Charalambous, H P


    End-to-side vascular anastomosis has a considerable complexity regarding the suturing of the juncture line between the artery and the graft. The present study proposes a stress-concentration methodology for the prediction of the stress distribution at the juncture line, aiming to provide generic expressions describing the response of an end-to-side anastomosis. The proposed methodology is based on general results obtained from the analysis of pipe connections, a topic that has been investigated in recent years in the field of offshore structural engineering. A key aspect for implementing the stress-concentration-factor approach is the recognition that the axial load due to pressure and flow dynamics exerted along the graft axis controls the "hot spots" on the juncture line, which in turn affects the mechanical response of the sutures. Several parameters, identified to influence the suture line response, are introduced in closed-form expressions for the suture line response calculations. The obtained results compare favorably with finite element results published in the literature. The proposed model predicts analytically the suture line response of end-to-side anastomosis, while capturing the influence of and interdependence among the problem parameters. Lower values of the graft radius, the distance between sequential stitches, and the intersecting angle between the artery and the graft are some of the key parameters that reduce the suture line response. The findings of this study are broad in scope and potentially applicable to improving the end-to-side anastomosis technique through improved functionality of the sutures and optimal selection of materials and anastomosis angle.

  6. Predictors of patency after two-stitch invagination vaso-epididymal anastomosis for idiopathic obstructive azoospermia

    Directory of Open Access Journals (Sweden)

    G Gautam


    Full Text Available Objectives: Anastomotic patency with return of sperm in the ejaculate following microsurgical vasoepididymostomy (VEA is not universal and may be delayed. The ability to predict the result of VEA based on preoperative or intra-operative parameters would enable the surgeon to offer the best treatment to the infertile couple. We used the two-stitch invagination technique of VEA in patients of idiopathic obstructive azoospermia and prospectively analyzed factors that could predict a patent anastomosis. While such studies have previously been done for patients undergoing VEA for secondary infertility following a vasectomy, to the best of our knowledge this is the first study analyzing these parameters for patients with primary infertility and idiopathic obstruction. Methods and materials: Over a 2-year period, 29 men underwent the 2-suture invagination VEA for idiopathic obstructive azoospermia. Twenty-four patients provided at least one postoperative semen sample. Preoperative and intra-operative parameters were compared between patients with a patent anastomosis with sperm in ejaculate (n = 12 and those with no sperm in the ejaculate (n = 12 using the t-test, Fisher′s exact test or chi-square test, as appropriate and a multivariate statistical analysis to determine any significant difference. Results: The mean follow up of the 24 patients was 7.6 months (2-30 months. A significantly greater number of patients with patent anastomosis had motile epididymal sperms (P = 0.034 and higher surgeon′s technical satisfaction with the procedure (P = 0.034. However, this difference was seen only on a univariate analysis and did not persist when a multivariate analysis was used. Conclusions: The presence of motile sperms in the epididymal fluid and a high level of technical satisfaction with the anastomosis may indicate a higher likelihood of success following a vaso-epididymal anastomosis for idiopathic obstruction. However, these parameters are not

  7. Anastomotic leak rate and outcome for laparoscopic intra-corporeal stapled anastomosis

    Directory of Open Access Journals (Sweden)

    Goriainov Vitali


    Full Text Available Aims :A prospective clinical audit of all patients undergoing laparoscopic surgery with the intention of primary colonic left-sided intracorporeal stapled anastomosis to identify the rate of anastomotic leaks on an intention to treat basis with or without defunctioning stoma. Materials and Methods : All patients undergoing laparoscopic colorectal surgery resulting in left-sided stapled anastomosis were included with no selection criteria applied. All operations were conducted by the same surgical team and the same preparation and intraoperative methods were used. The factors analyzed for this audit were patient demographics (age and sex, indication for operation, procedure performed, height of anastomosis, leak rate and the outcome, inpatient stay, mortality, rate of defunctioning stomas, and rate of conversion to open procedure. Results for anastomotic leakage were compared with known results from the Wessex Colorectal Audit for open colorectal surgery. Results : A total of 69 patients (43 females, 26 males; median age 69 years, range 19 - 86 years underwent colonic procedures with left-sided intracorporeal stapled anastomoses. Of these, 14 patients underwent reversal of Hartmann′s, 42 - Anterior Resection, 11 - Sigmoid Colectomy, 2 - Left Hemicolectomy. Excluding reversals of Hartmann′s, 29 operations were performed for malignant and 26 for benign disease. Five patients were defunctioned, and 3 were subsequently reversed. The median height of anastomosis was 12 cm, range 4 - 18 cm from anal verge as measured either intra-operatively, or by rigid sigmoidoscopy post-operatively. Four cases were converted to open surgery. There was 1 post-operative death within 30 days. There was 1 anastomotic leak (the patient that died, and 1 patient developed a colo-vesical fistula. Median post-operative stay was 7 days, range 2-19. Conclusion : This clinical audit confirms that the anastomotic leak rate for left-sided colorectal stapled anastomosis is no

  8. Utility of contrast enema for detecting anastomotic strictures after total proctocolectomy and ileal pouch-anal anastomosis. (United States)

    Dolinsky, David; Levine, Marc S; Rubesin, Stephen E; Laufer, Igor; Rombeau, John L


    The purpose of our study was to determine the utility of contrast enemas for detecting clinically relevant anastomotic strictures after total proctocolectomy and ileal pouch-anal anastomosis and to facilitate management by defining a critical anastomotic caliber at or below which obstruction is likely to develop after ileostomy closure. Our radiology database revealed 42 patients with contrast enemas after total proctocolectomy and ileal pouch-anal anastomosis who fulfilled our exclusion criteria. The initial postoperative contrast enemas were reviewed blindly to determine the diameter of the ileoanal anastomosis. The diagnosis of a stricture was made only if the patient had signs of intestinal obstruction after ileostomy closure with confirmation on follow-up contrast enema or sigmoidoscopy and clinical improvement after anastomotic dilatation. The data were then correlated to determine if there was a critical anastomotic caliber at or below which such strictures were likely to develop. Using this threshold value, the sensitivity and specificity of routine contrast enemas for detecting clinically relevant anastomotic strictures were then determined. Six (14%) of the 42 patients who underwent total proctocolectomy and ileal pouch-anal anastomosis had strictures at the ileoanal anastomosis on contrast enemas. The mean diameter of the anastomosis was 5.8 mm in the six patients with anastomotic strictures versus 15 mm in the 36 patients without strictures (p = 0.0002). If an anastomotic diameter of 8 mm is defined as the critical caliber at or below which clinically relevant strictures are present, the sensitivity of contrast enemas for detecting strictures at the ileoanal anastomosis was 100% (six of six patients) and the specificity was 92% (33 of 36 patients). Routine contrast enema after total proctocolectomy and ileal pouch-anal anastomosis is a sensitive test for detecting clinically relevant strictures at the ileoanal anastomosis when an anastomotic diameter of

  9. Saturn's dynamic D ring (United States)

    Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.


    The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

  10. Anastomosis cava-pulmonar en el tratamiento quirúrgico de la tetralogía de fallot


    Patiño, José Félix; Demner, Sigifredo; Alvarado, Enrique; Colmenares, Jorge


    Se informa sobre la aplicación clínica exitosa de la técnica de anastomosis cava-pulmonar, originalmente descrito por Glenn y Patiño, en un caso de Tetralogía de Fallot. Representa este caso el primer paciente tratado en esta forma en la literatura médica occidental. La anastomosis cava-pulmonar es un procedimiento técnicamente muy sencillo que permite mejorar notablemente la oxigenación en pacientes que presentan ciertas anomalías en el corazón derecho o en la arteria pulmonar. La anastomosi...

  11. Identification of Spanish isolates of Rhizoctonia solani from potato by anastomosis grouping, ITS-RFLP and RAMS-fingerprinting

    Directory of Open Access Journals (Sweden)

    A.M. Elbakali


    Full Text Available Anastomosis grouping, restriction fragment length polymorphism (RFLP of the ITS regions including the 5.85 rDNA, and random amplified microsatellites (RAMS were used to characterize isolates of Rhizoctonia solani collected from Spain and Finland. There was a high similarity between the results obtained with the three techniques. RAMS markers revealed more genetic variation among isolates of R. solani than RFLP. The anastomosis group (AG–3 isolates were clearly separated from isolates belonging to other AGs by RAMS, RFLPs and anastomosis grouping. Almost all the isolates sampled from potato belonged to AG–3. No differences were observed between Spanish and Finnish AG–3 isolates.

  12. Thump, ring: the sound of a bouncing ball

    Energy Technology Data Exchange (ETDEWEB)

    Katz, J I, E-mail: katz@wuphys.wustl.ed [Department of Physics and McDonnell Center for the Space Sciences, Washington University, St Louis, MO 63130 (United States)


    A basketball bounced on a stiff surface produces a characteristic loud thump, followed by a high-pitched ringing. Describing the ball as an inextensible but flexible membrane containing compressed air, I formulate an approximate theory of the generation of these sounds and predict their amplitudes and waveforms.

  13. Algorithms for finite rings

    NARCIS (Netherlands)

    Ciocanea Teodorescu I.,


    In this thesis we are interested in describing algorithms that answer questions arising in ring and module theory. Our focus is on deterministic polynomial-time algorithms and rings and modules that are finite. The first main result of this thesis is a solution to the module isomorphism problem in

  14. Relativistic ring models

    Energy Technology Data Exchange (ETDEWEB)

    Ujevic, Maximiliano [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Letelier, Patricio S.; Vogt, Daniel [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Matematica, Estatistica e Computacao Cientifica. Dept. de Matematica Aplicada


    Full text: Relativistic thick ring models are constructed using previously found analytical Newtonian potential-density pairs for flat rings and toroidal structures obtained from Kuzmin-Toomre family of discs. This was achieved by inflating previously constructed Newtonian ring potentials using the transformation |z|{yields}{radical}z{sup 2} + b{sup 2}, and then finding their relativistic analog. The models presented have infinite extension but the physical quantities decays very fast with the distance, and in principle, one could make a cut-off radius to consider it finite. In particular, we present systems with one ring, two rings and a disc with a ring. Also, the circular velocity of a test particle and its stability when performing circular orbits are presented in all these models. Using the Rayleigh criterion of stability of a fluid at rest in a gravitational field, we find that the different systems studied present a region of non-stability that appears in the intersection of the disc and the ring, and between the rings when they become thinner. (author)

  15. EBT ring physics

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, N.A. (ed.)


    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)

  16. Illustration of Saturn's Rings (United States)


    This illustration shows a close-up of Saturn's rings. These rings are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.

  17. Smoke Ring Physics (United States)

    Huggins, Elisha


    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  18. Estimates of post-acceleration longitudinal bunch compression

    Energy Technology Data Exchange (ETDEWEB)

    Judd, D.L.


    A simple analytic method is developed, based on physical approximations, for treating transient implosive longitudinal compression of bunches of heavy ions in an accelerator system for ignition of inertial-confinement fusion pellet targets. Parametric dependences of attainable compressions and of beam path lengths and times during compression are indicated for ramped pulsed-gap lines, rf systems in storage and accumulator rings, and composite systems, including sections of free drift. It appears that for high-confidence pellets in a plant producing 1000 MW of electric power the needed pulse lengths cannot be obtained with rings alone unless an unreasonably large number of them are used, independent of choice of rf harmonic number. In contrast, pulsed-gap lines alone can meet this need. The effects of an initial inward compressive drift and of longitudinal emittance are included.

  19. Imaging rings in ring imaging Cherenkov counters

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, Blair N


    The general concepts used to form images in Ring Imaging Cherenkov (RICH) counters are described and their performance properties compared. Particular attention is paid to issues associated with imaging in the time dimension, especially in Detectors of Internally Reflected Cherenkov light (DIRCs).

  20. Inflatable O-ring seal would ease closing of hatch cover plate (United States)

    Neary, K. J.


    Inflatable O-ring seal provides positive sealing means that does not require the manual exertion of a large compressive force during opening or closing of a rotary-type hatch cover plate. The O-ring is deflated during opening and closing and inflated after closure by a gas pressure source.

  1. Rings and their modules

    CERN Document Server

    Bland, Paul E


    This book is an introduction to the theory of rings and modules that goes beyond what one normally obtains in a graduate course in abstract algebra. In addition to the presentation of standard topics in ring and module theory, it also covers category theory, homological algebra and even more specialized topics like injective envelopes and projective covers, reflexive modules and quasi-Frobenius rings, and graded rings and modules. The book is a self-contained volume written in a very systematic style: allproofs are clear and easy for the reader to understand and allarguments are based onmaterials contained in the book. A problem sets follow each section. It is suitable for graduate and PhD students who have chosen ring theory for their research subject.

  2. Effect of Ozone Therapy (OT) on Healing of Colonic Anastomosis in a Rat Model of Peritonitis. (United States)

    Erginel, Başak; Erginel, Turgay; Aksoy, Bilgin; Dokucu, Ali İhsan


    Ozone is a three-oxygen molecule (O3). Ozone therapy (OT) is systematically effective when pathological inflammatory and immunologic processes are activated. Among of these conditions are wound healing, macular degeneration related to aging, and conditions that are ischemic or infectious. The aim of this study was to determine the effects of OT on wound healing of intestinal anastomosis in the presence of peritonitis in a rat model. Animal experimentation. A total of 40 Wistar albino rats were randomized into four groups (n=10) including: sham (S), peritonitis (P), ozone 0 (O0), and ozone 24 (O24). In group S, only cecal dissection was carried out. The S group had only a cecal dissection and intestinal anastomosis performed, but no peritonitis. In all other groups, cecal ligation and puncture (CLP) followed the cecal dissection to induce bacterial peritonitis. 24 h after puncture, a cecal resection and ileocolic anastomosis were performed. In group P, 24 h after CLP, a cecal resection and ileocolic anastomosis were performed and no ozone was administered. In group O0, immediately after the anastomosis, and in group O24, starting 24 hours after the anastomosis, an intraperitoneal 1 mg/kg/day ozone administration was applied for seven days. On the seventh day the animals were sacrificed, the anastomotic bursting pressures (BP) and the hydroxyproline values of the anastomotic tissues were measured, and histopathologic examination of the anastomotic segment was carried out. The highest BP was in group S, with 211±23.13 mmHg. The mean BP of group P was 141±56.25 mmHg, which was significantly lower than in the other two peritonitis groups that received ozone therapy, group O0 and O24, where it was 192±22 and 166±45 mmHg, respectively (p0.05). Histopathologic analyses of the anastomotic segments determined there was significantly more oedema and necrosis in the control group rats, and collagen deposition in the anastomotic tissue was significantly higher in the ozone

  3. Genital and Subjective Sexual Response in Women After Restorative Proctocolectomy with Ileal Pouch Anal Anastomosis-A Prospective Clinical Trial

    NARCIS (Netherlands)

    Vlug, Malaika S.; Laan, Ellen T.; van Lunsen, Rik H. W.; van Koperen, Paul J.; Polle, Sebastiaan W.; Bemelman, Willem A.


    Introduction. Sexual dysfunction after ileo pouch anal anastomosis (IPAA) is common. The most systematic physical reaction to sexual stimulation is an increase in vaginal vasocongestion. Genital response can be assessed by vaginal pulse amplitude (VPA) using vaginal photoplethysmography. Aim. To

  4. Successful treatment of recurrent stoma prolapse after Hartmann’s procedure through ileorectal anastomosis: A case report

    Directory of Open Access Journals (Sweden)

    Noriya Takayama


    Conclusion: We suggest that ileorectal anastomosis may be an optimal surgical treatment for patients with recurrent stoma prolapse and concomitant colonic motility disorder who have undergone Hartmann’s procedure.

  5. Evaluation of strategies for the control of canola and lupin seedling diseases caused by Rhizoctonia anastomosis groups (United States)

    Several methods with potential for the management of Rhizoctonia diseases of canola and lupin including several methods with potential for the management of Rhizoctonia plant resistance, fungicide seed treatment and biological control using binucleate Rhizoctonia anastomosis groups (AGs) were evalua...

  6. Technique Selection of Bricker or Wallace Ureteroileal Anastomosis in Ileal Conduit Urinary Diversion: A Strategy Based on Patient Characteristics

    National Research Council Canada - National Science Library

    Liu, Longfei; Chen, Minfeng; Li, Yuan; Wang, Long; Qi, Fan; Dun, Jingeng; Chen, Jinbo; Zu, Xiongbing; Qi, Lin


    ... (Bricker and Wallace anastomosis) used in ileal conduit (IC) diversion. Patients who underwent IC diversion after radical cystectomy for transitional cell carcinoma between January 2009 and December 2011 were prospectively collected...

  7. Central arteriovenous anastomosis for the treatment of patients with uncontrolled hypertension (the ROX CONTROL HTN study): a randomised controlled trial.

    LENUS (Irish Health Repository)

    Lobo, Melvin D


    Hypertension contributes to cardiovascular morbidity and mortality. We assessed the safety and efficacy of a central iliac arteriovenous anastomosis to alter the mechanical arterial properties and reduce blood pressure in patients with uncontrolled hypertension.

  8. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix


    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  9. Nanoscale borromean rings. (United States)

    Cantrill, Stuart J; Chichak, Kelly S; Peters, Andrea J; Stoddart, J Fraser


    The molecular expression of topologically interesting structures represents a formidable challenge for synthetic chemists. The nontrivial link known as the Borromean rings has long been regarded as one of the most ambitious targets in this field. Of ancient provenance, this symbol comprises three interlocked rings in an inseparable union, but cut any one of the rings and the whole assembly unravels into three separate pieces. This Account delineates different strategies that can be applied to the formation of molecules possessing this distinctive topology, culminating with two successful syntheses of such compounds, thus cutting the Gordian knot of topological chemistry.

  10. Saturn's Rings are Fractal


    Li, Jun; Ostoja-Starzewski, Martin


    Over the past few decades, various conjectures were advanced that Saturn's rings are Cantor-like sets, although no convincing fractal analysis of actual images has ever appeared. We focus on the images sent by the Cassini spacecraft mission: slide #42 "Mapping Clumps in Saturn's Rings" and slide #54 "Scattered Sunshine". Using the box-counting method, we determine the fractal dimension of rings seen here (and in several other images from the same source) to be consistently about 1.6~1.7. This...

  11. Modified Newton's rings: II


    Chaitanya, T. Sai; Kumar, Rajiv; Krishna, V. Sai; Anandh, B Shankar; Umesh, K S


    In an earlier work (Shankar kumar Jha, A Vyas, O S K S Sastri, Rajkumar Jain & K S Umesh, 'Determination of wavelength of laser light using Modified Newton's rings setup', Physics Education, vol. 22, no.3, 195-202(2005)) reported by our group, a version of Newton's rings experiment called Modified Newton's rings was proposed. The present work is an extension of this work. Here, a general formula for wavelength has been derived, applicable for a plane of observation at any distance. A relation...

  12. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B


    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation...... with the probe L1.26 confirmed the derivation from chromosome 13 and DNA polymorphism analysis showed maternal origin of the ring chromosome. Our results, together with a review of previous reports of cases with ring chromosome 13 with identified breakpoints, could neither support the theory of distinct clinical...

  13. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M


    In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

  14. Effect of anastomosis level on continence performance and quality of life after colonic J-pouch reconstruction. (United States)

    Otto, Susanne; Kroesen, Anton J; Hotz, Hubert G; Buhr, Heinz J; Kruschewski, Martin


    Total mesorectal excision (TME) has become the recommended method for treatment of cancer in the middle or lower third of the rectum. Thus very low anastomoses are necessary to preserve continence, and pouch reconstruction is favored. It is unclear whether the level of anastomosis is important for continence and quality of life in colonic J-pouch reconstruction. In this investigation all patients were included who underwent curative elective anterior continuity resection with colorectal or coloanal J-pouch reconstruction for primary rectal cancer between January 2001 and December 2004. Exclusion criteria were distant metastases and any signs of recurrence at the time of investigation. Evaluation of continence performance by Wexner and Holschneider questionnaire and quality of life using the QLQ-C30 and QLQ-CR38 (EORTC) questionnaires was done 220 +/- 38 days after closure of the protective Ileostomy, which was performed 106 +/- 48 days after primary intervention. Fifty-two patients (79%) were analyzed. Colopouch rectal anastomosis was performed in eighteen cases and colopouch anal anastomosis in thirty-four cases. Fifty percent of the patients in both groups were continent for solid stool. Patients with a colopouch anal anastomosis had a significantly higher rate of incontinence for liquid stool, however. They took stool-regulating medicine more frequently and complained of fecal soiling and a restricted quality of life. Patients with a colopouch anal anastomosis had a significantly lower score on the most important points of the QLQ-C30 (emotional functioning, social functioning, pain, and quality of life). The same applied to the QLQ-CR38 for body image and problems with defecation. The quality of life of patients with a colopouch anal anastomosis was still considered acceptable compared with reference data for the normal healthy population, however. Both continence and quality of life are substantially affected by the level of the anastomosis after colonic pouch

  15. Modified esophagogastrostomy in laparoscopy-assisted proximal gastrectomy: A reverse-Tornado anastomosis. (United States)

    Kubota, Keisuke; Suzuki, Akihiro; Fujikawa, Aoi; Watanabe, Takayuki; Sekido, Yuki; Shiozaki, Hironori; Taketa, Takashi; Shimada, Gen; Ohigashi, Seiji; Sakurai, Shintaro; Kishida, Akihiro


    The aim of this study was to introduce and examine a modified mechanical end-to-side esophagogastrostomy method ("reverse-Tornado" anastomosis) in laparoscopy-assisted proximal gastrectomy. Five patients with gastric cancer who underwent laparoscopy-assisted proximal gastrectomy were analyzed retrospectively. Esophagogastrostomy in the anterior wall was performed in three patients, and esophagogastrostomy in the posterior wall was performed in two patients. Clinicopathological features, operative outcomes (operative time, operative blood loss), and postoperative outcomes (complications, postoperative hospital stay, reflux esophagitis) were evaluated. Operative time was normal (278 min). There was no marked operative blood loss, postoperative complications, prolonged hospital stay, or reflux esophagitis. Esophagogastrostomy was completed in a normal time with reverse-Tornado anastomosis. This method can be safe and can enable good postoperative quality of life. © 2016 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

  16. Colovaginal anastomosis: an unusual complication of stapler use in restorative procedure after Hartmann operation

    Directory of Open Access Journals (Sweden)

    Liao Guoqing


    Full Text Available Abstract Background Rectovaginal fistula is uncommon after lower anterior resection for rectal cancer. The most leading cause of this complication is involvement of the posterior wall of the vagina into the staple line when firing the circular stapler. Case presentation A 50-year-old women underwent resection for obstructed carcinoma of the sigmoid colon with Hartmann procedure. Four months later she underwent restorative surgery with circular stapler. Following which she developed rectovaginal fistula. A transvaginal repair was performed but stool passing from vagina not per rectum. Laporotomy revealed colovaginal anastomosis, which was corrected accordingly. Patient had an uneventful recovery. Conclusion Inadvertent formation of colovaginal anastomosis associated with a rectovaginal fistula is a rare complication caused by the operator's error. The present case again highlights the importance of ensuring that the posterior wall of vagina is away from the staple line.

  17. Transvaginal coloanal anastomosis after rectal resection for the treatment of a rectovaginal fistula induced by radiation. (United States)

    Brezean, I


    Although decreasing in number, radiation induced rectovaginal fistulas are caused by some radiation injuries and chronic ischemic lesions. Most of the experienced authors recommend anterior rectal resection with coloanal anastomosis accessed through the abdominal-perineum area for high fistula. We present a patient with a fistula that developed 23 years after hysterectomy and radiotherapy. In this case we performed an abdominal-transvaginal rectal resection with transverse coloplastypouch, coloanal anastomosis and protection ileostomy three months after a terminal sigmoidostomy. The dissection of the distal rectum by posteriour colpotomy and coloanal transvaginalan astomosis is a technical variant that may prove advantage ous compared to the procedures featured in the literature as solutions by rectal resection for rectovaginal fistula. Celsius.

  18. A meta-analysis of aneurysm formation in laser assisted vascular anastomosis (LAVA) (United States)

    Chen, Chen; Peng, Fei; Xu, Dahai; Cheng, Qinghua


    Laser assisted vascular anastomosis (LAVA) is looked as a particularly promising non-suture method in future. However, aneurysm formation is one of the main reasons delay the clinical application of LAVA. Some scientists investigated the incidence of aneurysms in animal model. To systematically analyze the literature on reported incidence of aneurysm formation in LAVA therapy, we performed a meta-analysis comparing LAVA with conventional suture anastomosis (CSA) in animal model. Data were systematically retrieved and selected from PUBMED. In total, 23 studies were retrieved. 18 studies were excluded, and 5 studies involving 647 animals were included. Analysis suggested no statistically significant difference between LAVA and CSA (OR 1.24, 95%CI 0.66-2.32, P=0.51). Result of meta analysis shows that the technology of LAVA is very close to clinical application.

  19. A new anastomosis technique for intestinal diseases with proximal dilated segments

    Directory of Open Access Journals (Sweden)

    Metin Gündüz


    Full Text Available A number of techniques have been described for intestinal anastomosis. We describe a different, simple, and safe technique that can be used in patients with intestinal diseases, such as jejunoileal atresia and perforation that has proximal dilated segments. In this technique, an atraumatic bowel clamp was applied on the proximal dilated bowel at a 90° angle. In the narrow distal segment, we resected the bowel at a 0° angle and continued at a 30° angle from the antimesenteric side. Finally, a two-layer interrupted anastomosis was performed. We applied this technique to a 31-day-old patient who had a divided jejunostomy due to malrotation and perforation with a proximal dilated bowel. Neither anastomotic complications nor feeding and passage problems were seen postoperatively.

  20. Laparoscopic restorative proctocolectomy ileal pouch anal anastomosis: How I do it? (United States)

    Madnani, Manish A; Mistry, Jitendra H; Soni, Harshad N; Shah, Atul J; Patel, Kantilal S; Haribhakti, Sanjiv P


    Surgery for ulcerative colitis is a major and complex colorectal surgery. Laparoscopy benefits these patients with better outcomes in context of cosmesis, pain and early recovery, especially in young patients. For surgeons, it is a better tool for improving vision and magnification in deep cavities. This is not the simple extension of the laparoscopy training. Starting from preoperative preparation to post operative care there are wide variations as compared to open surgery. There are also many variations in steps of laparoscopic surgery. It involves left colon, right colon and rectal mobilisation, low division of rectum, pouch creation and anastomosis of pouch to rectum. Over many years after standardisation of this technique, it takes same operative time as open surgery at our centre. So we present our standardized technique of laparoscopic assisted restorative proctocolectomy and ileal pouch anal anastomosis (IPAA). PMID:26195886

  1. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Rune Hansen, Esben; Srinivasa Rao, S.; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1......-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances....

  2. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter


    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1......-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances...

  3. Partial recovery of respiratory function and diaphragm reinnervation following unilateral vagus nerve to phrenic nerve anastomosis in rabbits.

    Directory of Open Access Journals (Sweden)

    Junxiang Wen

    Full Text Available Respiratory dysfunction is the leading cause of mortality following upper cervical spinal cord injury (SCI. Reinnervation of the paralyzed diaphragm via an anastomosis between phrenic nerve and a donor nerve is a potential strategy to mitigate ventilatory deficits. In this study, anastomosis of vagus nerve (VN to phrenic nerve (PN in rabbits was performed to assess the potential capacity of the VN to compensate for lost PN inputs. At first, we compared spontaneous discharge pattern, nerve thickness and number of motor fibers between these nerves. The PN exhibited a highly rhythmic discharge while the VN exhibited a variable frequency discharge pattern. The rabbit VN had fewer motor axons (105.3±12.1 vs. 268.1±15.4. Nerve conduction and respiratory function were measured 20 weeks after left PN transection with or without left VN-PN anastomosis. Compared to rabbits subjected to unilateral phrenicotomy without VN-PN anastomosis, diaphragm muscle action potential (AP amplitude was improved by 292%, distal latency by 695%, peak inspiratory flow (PIF by 22.6%, peak expiratory flow (PRF by 36.4%, and tidal volume by 21.8% in the anastomosis group. However, PIF recovery was only 28.0%, PEF 28.2%, and tidal volume 31.2% of Control. Our results suggested that VN-PN anastomosis is a promising therapeutic strategy for partial restoration of diaphragm reinnervation, but further modification and improvements are necessary to realize the full potential of this technique.

  4. Hyperspectral data compression

    CERN Document Server

    Motta, Giovanni; Storer, James A


    Provides a survey of results in the field of compression of remote sensed 3D data, with a particular interest in hyperspectral imagery. This work covers topics such as compression architecture, lossless compression, lossy techniques, and more. It also describes a lossless algorithm based on vector quantization.

  5. [Endoprosthesis of the frontonasal anastomosis after extranasal radical operations using biocompatible tubular polymeric materials]. (United States)

    Klochikhin, A L; Markov, G I; Shilenkova, V V


    The authors present pilot experience of extranasal radical operations on the frontal sinuses with the use of polymeric tube endoprostheses made of biocompatible polymeric materials EFOS 1, 2, 3 containing antimicrobial drugs (dioxidin, chinoxidin) and active substances promoting regeneration and epithelization (orotic acid derivatives). The above technique was employed in operations on frontal sinuses in 12 patients. Polymeric endoprostheses EFOS provide adequate lumen of the formed frontonasal anastomosis, reduce the occurrence of postoperative complications and recurrences as well as hospital stay.

  6. Anastomosis between accessory middle cerebral artery and middle cerebral artery diagnosed by magnetic resonance angiography. (United States)

    Takahashi, Masao; Uchino, Akira; Suzuki, Chihiro


    The accessory middle cerebral artery (MCA) is a common variation of the MCA that arises from the anterior cerebral artery. We report a patient with anastomosis of the accessory MCA with the main MCA, an extremely rare variant that we diagnosed by magnetic resonance (MR) angiography. Both partial maximum-intensity-projection and partial volume-rendering MR angiographic images obtained at 3 T are useful to identify such rare vascular variation.

  7. Aberrant cervical vasculature anastomosis as cause of neck pain and successful treatment with embolization technique. (United States)

    He, Lucy; Ladner, Travis R; Cobb, Mark; Mocco, J


    We report a patient with non-dermatomal radiating neck pain without focal neurologic deficit. Traditional workup could not identify an anatomic or biomechanical cause. Imaging showed a deep cervical vessel centered in the region of pain. Angiography later identified an aberrant anastomosis of this vessel with the occipital artery. Subsequent endovascular embolization of this arterial trunk resulted in complete pain relief. 2016 BMJ Publishing Group Ltd.

  8. [A case of dural AVM detected after STA-MCA anastomosis]. (United States)

    Igase, K; Oka, Y; Kumon, Y; Zenke, K; Iwata, S; Sakaki, S


    A case of dural arteriovenous malformation (AVM) in the posterior cranial fossa detected after STA-MCA anastomosis surgery. A 52-year-old male consulted a neighbourhood hospital for sudden headache and vomiting. He was diagnosed as having intraventricular hemorrhage on CT scan. Though the obstruction of the right internal carotid artery was revealed angiographically, his symptoms improved after conservative therapy. Two weeks after onset, his consciousness deteriorated and he developed left hemiparesis. Thereafter, he was transferred to our hospital. After thorough examination, right STA-MCA anastomosis surgery was performed. Approximately 2 months after surgery, right tinnitus developed and gradually exacerbated. Since it was thought to be due to increased blood flow in the right superficial temporal artery, it was kept under observation. On angiogram, 8 months after surgery, good blood flow supplied from the right superficial temporal artery to the territory of the right middle cerebral artery was shown, and a dural AVM fed by the right occipital artery was found. Fourteen months after the surgery, an enlarged dural AVM with backflow to the superficial cerebral veins fed by the enlarged right occipital artery and right ascending pharyngeal artery was revealed. Embolization therapy to the right occipital and ascending pharyngeal artery was performed using coils and ivalon, and irradiation of 30 Gy was added. After this treatment, right tinnitus improved. On angiography 2 years later, transverse sinus was slightly visible via the right occipital artery and ascending pharyngeal artery, but the dural AVM was significantly reduced. The origin of dural AVMs remains controversial. In our case, dural AVM was not found before the STA-MCA anastomosis surgery, and sinus thrombosis was not found throughout the course of observation. It is thought that the occult dural AVM was disclosed and enlarged by the increased blood flow through the external carotid artery via the STA

  9. Real-time 3D Fourier-domain optical coherence tomography guided microvascular anastomosis (United States)

    Huang, Yong; Ibrahim, Zuhaib; Lee, W. P. A.; Brandacher, Gerald; Kang, Jin U.


    Vascular and microvascular anastomosis is considered to be the foundation of plastic and reconstructive surgery, hand surgery, transplant surgery, vascular surgery and cardiac surgery. In the last two decades innovative techniques, such as vascular coupling devices, thermo-reversible poloxamers and suture-less cuff have been introduced. Intra-operative surgical guidance using a surgical imaging modality that provides in-depth view and 3D imaging can improve outcome following both conventional and innovative anastomosis techniques. Optical coherence tomography (OCT) is a noninvasive high-resolution (micron level), high-speed, 3D imaging modality that has been adopted widely in biomedical and clinical applications. In this work we performed a proof-of-concept evaluation study of OCT as an assisted intraoperative and post-operative imaging modality for microvascular anastomosis of rodent femoral vessels. The OCT imaging modality provided lateral resolution of 12 μm and 3.0 μm axial resolution in air and 0.27 volume/s imaging speed, which could provide the surgeon with clearly visualized vessel lumen wall and suture needle position relative to the vessel during intraoperative imaging. Graphics processing unit (GPU) accelerated phase-resolved Doppler OCT (PRDOCT) imaging of the surgical site was performed as a post-operative evaluation of the anastomosed vessels and to visualize the blood flow and thrombus formation. This information could help surgeons improve surgical precision in this highly challenging anastomosis of rodent vessels with diameter less than 0.5 mm. Our imaging modality could not only detect accidental suture through the back wall of lumen but also promptly diagnose and predict thrombosis immediately after reperfusion. Hence, real-time OCT can assist in decision-making process intra-operatively and avoid post-operative complications.

  10. An intraluminal prosthesis may improve healing of a one-layer colonic anastomosis

    DEFF Research Database (Denmark)

    Buch, N; Glad, H; Svendsen, P


    OBJECTIVE: To compare healing of one-layer colonic anastomoses with or without a soluble intraluminal prosthesis (* SBS-tube). DESIGN: Randomised, partly blinded controlled study. SETTING: University hospital, Denmark. SUBJECTS: 16 female Danish country strain pigs, of which 8 had the SBS tube in...... of the anastomosis and may improve healing, possibly because of better apposition of the cut ends and reduced tension in the sutures....

  11. Transanal Inspection and Management of Low Colorectal Anastomosis Performed With a New Technique: the TICRANT Study. (United States)

    Crafa, Francesco; Smolarek, Sebastian; Missori, Giulia; Shalaby, Mostafa; Quaresima, Silvia; Noviello, Adele; Cassini, Diletta; Ascenzi, Pasquale; Franceschilli, Luana; Delrio, Paolo; Baldazzi, Giannandrea; Giampiero, Ucchino; Megevand, Jacques; Maria Romano, Giovanni; Sileri, Pierpaolo


    Anastomotic leakage is one of the most serious complications after rectal cancer surgery. A prospective multicenter interventional study to assess a newly described technique of creating the colorectal and coloanal anastomosis. The primary outcome was to access the safety and efficacy of this technique in the reduction of anastomotic leak. Fifty-three patients with rectal cancer who underwent low or ultra-low anterior resection were included in the study. There were 35 males and 18 females, with a median age of 68 years (range = 49-89 years). The median tumor distance from the anal verge was 8 cm (range = 4-12 cm), and the median body mass index was 24 kg/m(2) (range = 20-35 kg/m(2)). Thirty patients underwent open, 16 laparoscopic, and 7 robotic surgeries. Multiple firing (2-charges) was required in 30 patients to obtain a complete rectal division. Forty-five patients had colorectal anastomosis, and 8 patients had coloanal anastomosis. The protective ileostomy was created in 40 patients at the time of initial surgery. There was no mortality in the first 30 days postoperatively, and only 10 (19%) patients developed complications. There were 3 anastomotic leakages (6%); 2 of them were subclinical with ileostomy created at initial operation and both were treated conservatively with transanal drainage and intravenous antibiotics. One patient required reoperation and ileostomy. The median length of hospital stay was 10 days (range = 4-20 days). Our technique is a safe and efficient method of creation of colorectal anastomosis. It is also a universal method that can be used in open, laparoscopic, and robotic surgeries.

  12. Inferior mesenteric artery stump pressure is an unreliable predictor of the outcome of colorectal anastomosis. (United States)

    Hsu, Tzu-Chi


    Ankle/brachial pressure is used as a predictor for the outcome of femoro-popliteal bypass. It has been suggested that a mean inferior mesenteric artery stump pressure (IMASP) below 40 mmHg after aortic reconstruction may be similarly predictive of postoperative ischemic colitis. No previous report has considered IMASP as a predictor of the integrity of colorectal anastomosis. The aim of the study is to examine the correlation between IMASP and anastomotic leakage rate after left colectomy. From April 2004 to March 2006, 99 patients undergoing left colon resection by a single surgeon were measured for their IMASP and arm systemic pressure (SP). All but two patients were operated for carcinoma of the colon or rectum. Sixty-nine patients had primary anastomosis without diverting stomies. The stump mean pressure varied from 24 to 75 mmHg. Seventy-nine patients (79.8%) had pressures equal or above 40 mmHg. IMASP/SP ratios ranged from 0.21 to 0.7. Sixty-seven patients (67.7%) had IMASP/SP ratios equal or above 0.4. Two patients were found to have postoperative leakage of anastomosis. Their IMASP were 35 and 70 mmHg, and their IMASP/SP ratios were 0.28 and 0.62, respectively. We could not identify a significant difference between the two groups, and the pressure of the inferior mesenteric artery could not be proven to be a relevant predictor of anastomotic leakage. This series suggested that IMASP lower than 40 mmHg or an IMASP/SP ratio less than 0.4 does not correlate with an increased leakage rate. Neither IMASP nor the IMASP/SP ratio is a reliable indicator for predicting the outcome of colorectal anastomosis.

  13. Improving the side-to-side stapled anastomosis: comparison of staplers for robust crotch formation. (United States)

    Kimura, Masahiro; Kuwabara, Yoshiyuki; Taniwaki, Satoshi; Mitsui, Akira; Shibata, Yasuyuki; Ueno, Shuhei


    Few studies have investigated the burst pressure of side-to-side anastomoses comparing different stapling devices that are commercially available. We conducted side-to-side anastomoses with a variety of staplers and compared burst pressure in the crotch of the anastomoses. Nagoya City East Medical Center. We conducted side-to-side anastomoses with 9 staplers with different shapes and forms. Fresh pig small intestines were used. A side-to-side anastomosis was performed between 2 intestine specimens using a linear stapler. The burst pressure of the anastomosis was recorded. In total, 45 staplers were used for this experiment. The site of leakage in all cases was the crotch. Regarding the influence of the number of staple rows, the burst pressure in 3-row staplers was significantly higher than in 2-row staplers. With regard to the relationship between staple height and burst pressure, staples with a height slightly shorter than the intestinal thickness showed the highest burst pressure. In a comparison of staplers with uniform staple heights and stamplers with staples of 3 different heights, the latter had significantly lower burst pressures. Neoveil significantly increased the burst pressure in the crotch and contributed to the highest burst pressure of all the staplers used in this experiment. In this experiment, we defined the important factors that influence burst pressure at the crotch of a stapled, side-to-side anastomosis. These factors include the number of staple rows, the height of the staple compared with the thickness of the tissue, uniformity of staple height, and reinforcement of the staple line. In any surgical case requiring intestinal anastomosis, selection of a stapler is a critical step. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  14. How to perform a coronary artery anastomosis in complete endoscopic fashion with robotic assistance. (United States)

    Canale, Leonardo Secchin; Bonatti, Johannes


    Current technology in robotic surgery allows us to perform myocardial revascularization procedures in a totally endoscopic fashion. We will describe the technique of choice for left internal mammary artery to left anterior descendent artery anastomosis with the use of cardiopulmonary bypass machine. The method is efficient and there is long term follow-up showing similar patency of the graft when compared to conventional methods (when performed through sternotomy).

  15. How to perform a coronary artery anastomosis in complete endoscopic fashion with robotic assistance (United States)

    Canale, Leonardo Secchin; Bonatti, Johannes


    Current technology in robotic surgery allows us to perform myocardial revascularization procedures in a totally endoscopic fashion. We will describe the technique of choice for left internal mammary artery to left anterior descendent artery anastomosis with the use of cardiopulmonary bypass machine. The method is efficient and there is long term follow-up showing similar patency of the graft when compared to conventional methods (when performed through sternotomy). PMID:25714222

  16. How to perform a coronary artery anastomosis in complete endoscopic fashion with robotic assistance

    Directory of Open Access Journals (Sweden)

    Leonardo Secchin Canale


    Full Text Available Current technology in robotic surgery allows us to perform myocardial revascularization procedures in a totally endoscopic fashion. We will describe the technique of choice for left internal mammary artery to left anterior descendent artery anastomosis with the use of cardiopulmonary bypass machine. The method is efficient and there is long term follow-up showing similar patency of the graft when compared to conventional methods (when performed through sternotomy.

  17. Novel Dry-Lab Training Method for Totally Endoscopic Coronary Anastomosis: A Pilot Study. (United States)

    Ujihira, Kosuke; Yamada, Akira

    We describe our original dry-lab training system for nonrobotic and beating heart endoscopic coronary artery anastomosis. All the materials used for this training were commercially available. We selected a boxed machine, which can produce pulsatile movements of artificial vessels, and on its roof, we installed a two-dimensional home video camera and a monitor. A multiple-holed plate was placed in front of the machine, and through these holes, a trainee inserted endoscopic surgical instruments and anastomosed the artificial vessels by running fashion while watching the monitor. This training program has four stages. During the first stage, a trainee has to demonstrate mastery in conducting a conventional off-pump coronary artery anastomosis without assistance. The second stage is the "nonbeating" version, and the third stage is the "beating" version with the model mentioned previously. After a trainee gets accustomed to the third stage, the original artificial vessel is replaced with an extremely fragile one, and this is the fourth stage. Our trainee conducted one hundred fourth-stage anastomoses and each procedure was recorded with the video camera. We analyzed several factors from the videos and evaluated the efficacy of the training method. We compared the outcomes of the first 50 consecutive anastomoses with the following 50 ones and described the learning curves. The comparison showed a significant decrease in anastomotic time and vessel injury. We considered the quality of anastomosis acceptable after 47 anastomoses, and anastomotic time fell below 15 minutes at the 81st training at the fourth stage. Our dry-lab system might be an effective training method for endoscopic coronary anastomosis.

  18. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre


    The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... the analogy to a doublet field is made. The following section derive the value of the vector potential and velocity field in the full domain. The expression for the velocity gradient is also provided since it may be relevant in a simulation with vortex particles and vortex rings. Most of this chapter...... is dedicated to vortex rings. Source rings are only briefly mentioned....

  19. The g-2 ring

    CERN Multimedia


    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  20. Ringed Seal Distribution Map (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) of the five subspecies of ringed seals (Phoca hispida). It was produced...

  1. Coronary artery bypass grafting hemodynamics and anastomosis design: a biomedical engineering review (United States)


    In this paper, coronary arterial bypass grafting hemodynamics and anastomosis designs are reviewed. The paper specifically addresses the biomechanical factors for enhancement of the patency of coronary artery bypass grafts (CABGs). Stenosis of distal anastomosis, caused by thrombosis and intimal hyperplasia (IH), is the major cause of failure of CABGs. Strong correlations have been established between the hemodynamics and vessel wall biomechanical factors and the initiation and development of IH and thrombus formation. Accordingly, several investigations have been conducted and numerous anastomotic geometries and devices have been designed to better regulate the blood flow fields and distribution of hemodynamic parameters and biomechanical factors at the distal anastomosis, in order to enhance the patency of CABGs. Enhancement of longevity and patency rate of CABGs can eliminate the need for re-operation and can significantly lower morbidity, and thereby reduces medical costs for patients suffering from coronary stenosis. This invited review focuses on various endeavors made thus far to design a patency-enhancing optimized anastomotic configuration for the distal junction of CABGs. PMID:24330653

  2. Laparoscopic Conversion of One Anastomosis Gastric Bypass to a Standard Roux-en-Y Gastric Bypass. (United States)

    Amor, Imed Ben; Petrucciani, Niccolo; Kassir, Radwan; Al Munifi, Abdullah; Piche, Thierry; Debs, Tarek; Gugenheim, Jean


    One anastomosis gastric bypass (OAGB) demonstrated results similar to traditional Roux-en-Y procedures [1-3], in terms of weight loss and resolution of obesity-related comorbidities. The main controversy regarding OAGB is the concern for an association between biliary alkaline gastritis and esophageal or gastric cancer raised by some studies [4]. We present the case of a 51-year-old woman with a BMI of 41 kg/m2 who underwent a laparoscopic OAGB in 2014. One year later, she consulted for recurrent heartburns. An upper GI endoscopy showed pouchitis and bile reflux in the esophagus. Medical treatment of gastroesophageal reflux disease was ineffective. We decided to convert the OAGB to a Roux-en-Y gastric bypass (RYGB). In this video, we show how to revise an OAGB to treat chronic bile reflux, by converting the procedure to a standard RYGB. The intervention starts by restoring the normal anatomy of the small bowel, with the resection of the gastrojejunal anastomosis, which was located at 250-cm du Treitz's ligament. Then, the gastric pouch is created. A standard Roux-en-Y gastric bypass is performed. The resection of the gastrojejunal anastomosis allows fashioning the Roux-en-Y limb with the classical measures. This technique allows a conversion to a standard RYGB and is effective in treating the biliary reflux.


    CASTRO, Paula Marcela Vilela; RIBEIRO, Felipe Piccarone Gonçalves; ROCHA, Amanda de Freitas; MAZZURANA, Mônica; ALVAREZ, Guines Antunes


    Introduction Postoperative anastomotic leak and stricture are dramatic events that cause increased morbidity and mortality, for this reason it's important to evaluate which is the best way to perform the anastomosis. Aim To compare the techniques of manual (hand-sewn) and mechanic (stapler) esophagogastric anastomosis after resection of malignant neoplasm of esophagus, as the occurrence of anastomotic leak, anastomotic stricture, blood loss, cardiac and pulmonary complications, mortality and surgical time. Methods A systematic review of randomized clinical trials, which included studies from four databases (Medline, Embase, Cochrane and Lilacs) using the combination of descriptors (anastomosis, surgical) and (esophagectomy) was performed. Results Thirteen randomized trials were included, totaling 1778 patients, 889 in the hand-sewn group and 889 in the stapler group. The stapler reduced bleeding (p <0.03) and operating time (p<0.00001) when compared to hand-sewn after esophageal resection. However, stapler increased the risk of anastomotic stricture (NNH=33), pulmonary complications (NNH=12) and mortality (NNH=33). There was no significant difference in relation to anastomotic leak (p=0.76) and cardiac complications (p=0.96). Conclusion After resection of esophageal cancer, the use of stapler shown to reduce blood loss and surgical time, but increased the incidence of anastomotic stricture, pulmonary complications and mortality. PMID:25184776

  4. Pouch Failures Following Ileal Pouch-anal Anastomosis for Ulcerative Colitis

    DEFF Research Database (Denmark)

    Mark-Christensen, Anders; Erichsen, Rune; Brandsborg, Søren


    BACKGROUND: The ileal pouch-anal anastomosis is a procedure offered to patients with ulcerative colitis who opt for restoration of bowel continuity. The aim of this study was to determine the risk of pouch failure and ascertain risk factors associated with failure. METHOD: 1,991 patients with ulc......BACKGROUND: The ileal pouch-anal anastomosis is a procedure offered to patients with ulcerative colitis who opt for restoration of bowel continuity. The aim of this study was to determine the risk of pouch failure and ascertain risk factors associated with failure. METHOD: 1,991 patients...... with ulcerative colitis operated with ileal pouch-anal anastomosis in Denmark in the period 1980-2013 were included. Pouch failure was defined as excision of the pouch or presence of a stoma un-reversed within one year after its creation. We used Cox proportional hazards regression to explore the association....... high-volume 2.30, 95% CI: 1.26-4.20) were also associated with a higher risk of failure. The risk of failure was not associated with calendar year, primary sclerosing cholangitis, synchronous colectomy, or laparoscopy. CONCLUSION: In a cohort of patients with ulcerative colitis and ileal pouch...

  5. Microvascular anastomosis in rodent model evaluated by Fourier domain Doppler optical coherence tomography (United States)

    Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.


    Vascular and microvascular anastomosis are critical components of reconstructive microsurgery, vascular surgery and transplant surgery. Imaging modality that provides immediate, real-time in-depth view and 3D structure and flow information of the surgical site can be a great valuable tool for the surgeon to evaluate surgical outcome following both conventional and innovative anastomosis techniques, thus potentially increase the surgical success rate. Microvascular anastomosis for vessels with outer diameter smaller than 1.0 mm is extremely challenging and effective evaluation of the outcome is very difficult if not impossible using computed tomography (CT) angiograms, magnetic resonance (MR) angiograms and ultrasound Doppler. Optical coherence tomography (OCT) is a non-invasive high-resolution (micron level), high-speed, 3D imaging modality that has been adopted widely in biomedical and clinical applications. Phaseresolved Doppler OCT that explores the phase information of OCT signals has been shown to be capable of characterizing dynamic blood flow clinically. In this work, we explore the capability of Fourier domain Doppler OCT as an evaluation tool to detect commonly encountered post-operative complications that will cause surgical failure and to confirm positive result with surgeon's observation. Both suture and cuff based techniques were evaluated on the femoral artery and vein in the rodent model.

  6. Technique of totally robotic delta-shaped anastomosis in distal gastrectomy

    Directory of Open Access Journals (Sweden)

    Hidehiko Kitagami


    Full Text Available Background: We aimed to clarify the utility of delta-shaped anastomosis (Delta, an intracorporeal Billroth-I anastomosis-based reconstruction technique used after laparoscopy-assisted distal gastrectomy (LADG, in robot-assisted distal gastrectomy (RADG. Methods: RADG was performed in patients with clinical Stage I gastric cancer, and reconstruction was performed using Delta. The Delta procedure was the same as that performed after LADG, and the operator practiced the procedure in simulated settings with surgical assistants before the operation. After gastrectomy, the scope and robotic first arm were reinserted from separate ports on the right side of the patient. Then, a port on the left side of the abdomen was used as the assistant port from which a stapler was inserted, with the robotic arm in a coaxial mode. The surgical assistant performed functional end-to-end anastomosis of the remnant stomach and duodenal stump using a powered stapler. Results: The mean anastomotic time in four patients who underwent Delta after RADG was 16.5 min. All patients were discharged on the post-operative day 7 without any post-operative complications or need for readmission. Conclusions: Pre-operative simulation, changes in ports for insertion of the scope and robotic first arm, continuation of the coaxial operation, and use of a powered stapler made Delta applicable for RADG. Delta can be considered as a useful reconstruction method.

  7. Technique of totally robotic delta-shaped anastomosis in distal gastrectomy. (United States)

    Kitagami, Hidehiko; Nonoyama, Keisuke; Yasuda, Akira; Kurashima, Yo; Watanabe, Kaori; Fujihata, Shiro; Yamamoto, Minoru; Shimizu, Yasunobu; Tanaka, Moritsugu


    We aimed to clarify the utility of delta-shaped anastomosis (Delta), an intracorporeal Billroth-I anastomosis-based reconstruction technique used after laparoscopy-assisted distal gastrectomy (LADG), in robot-assisted distal gastrectomy (RADG). RADG was performed in patients with clinical Stage I gastric cancer, and reconstruction was performed using Delta. The Delta procedure was the same as that performed after LADG, and the operator practiced the procedure in simulated settings with surgical assistants before the operation. After gastrectomy, the scope and robotic first arm were reinserted from separate ports on the right side of the patient. Then, a port on the left side of the abdomen was used as the assistant port from which a stapler was inserted, with the robotic arm in a coaxial mode. The surgical assistant performed functional end-to-end anastomosis of the remnant stomach and duodenal stump using a powered stapler. The mean anastomotic time in four patients who underwent Delta after RADG was 16.5 min. All patients were discharged on the post-operative day 7 without any post-operative complications or need for readmission. Pre-operative simulation, changes in ports for insertion of the scope and robotic first arm, continuation of the coaxial operation, and use of a powered stapler made Delta applicable for RADG. Delta can be considered as a useful reconstruction method.

  8. Immediate primary anastomosis for isolated oesophageal atresia: A single-centre experience

    Directory of Open Access Journals (Sweden)

    Ibrahim Uygun


    Full Text Available Background: Isolated oesophageal atresia without tracheo-oesophageal fistula represents a major challenge for most paediatric surgeons. Here, we present our experience with six neonates with isolated oesophageal atresia who successfully underwent immediate primary anastomosis using multiple Livaditis circular myotomy. Materials and Methods: All six neonates were gross type A isolated oesophageal atresia (6%, from among 102 neonates with oesophageal atresia, treated between January 2009 and December 2013. Five neonates were female; one was male. The mean birth weight was 2300 (range 1700-3100 g. Results: All six neonates successfully underwent immediate primary anastomosis using multiple myotomies (mean 3; range 2-4 within 10 (median 3 days after birth. The gap under traction ranged from 6 to 7 cm. One neonate died of a major cardiac anomaly. Another neonate was lost to follow-up after being well for 3 months. Three anastomotic strictures were treated with balloon dilatation, and four anastomotic leaks were treated conservatively. The mean duration of follow-up was 33 months. Conclusions: To treat isolated oesophageal atresia, an immediate primary anastomosis can be achieved using multiple myotomies. Although, this approach is associated with high complication rates, as are other similar approaches, these complications can be overcome.

  9. Integrations on rings

    Directory of Open Access Journals (Sweden)

    Banič Iztok


    Full Text Available In calculus, an indefinite integral of a function f is a differentiable function F whose derivative is equal to f. The main goal of the paper is to generalize this notion of the indefinite integral from the ring of real functions to any ring. We also investigate basic properties of such generalized integrals and compare them to the well-known properties of indefinite integrals of real functions.

  10. Matrimonial ring structures


    Hamberger, Klaus; Houseman, Michael; Daillant, Isabelle; White, Douglas R.; Barry, Laurent


    The paper deals with matrimonial rings, a particular kind of cycles in kinship networks which result when spouses are linked to each other by ties of consanguinity or affinity. By taking a network-analytic perspective, the paper endeavours to put this classical issue of structural kinship theory on a general basis, such as to allow conclusions which go beyond isolated discussions of particular ring types (like "cross-cousin marriage", "sister exchange", and so forth). The paper provides a def...

  11. MEMS-based handheld fourier domain Doppler optical coherence tomography for intraoperative microvascular anastomosis imaging.

    Directory of Open Access Journals (Sweden)

    Yong Huang

    Full Text Available To demonstrate the feasibility of a miniature handheld optical coherence tomography (OCT imager for real time intraoperative vascular patency evaluation in the setting of super-microsurgical vessel anastomosis.A novel handheld imager Fourier domain Doppler optical coherence tomography based on a 1.3-µm central wavelength swept source for extravascular imaging was developed. The imager was minimized through the adoption of a 2.4-mm diameter microelectromechanical systems (MEMS scanning mirror, additionally a 12.7-mm diameter lens system was designed and combined with the MEMS mirror to achieve a small form factor that optimize functionality as a handheld extravascular OCT imager. To evaluate in-vivo applicability, super-microsurgical vessel anastomosis was performed in a mouse femoral vessel cut and repair model employing conventional interrupted suture technique as well as a novel non-suture cuff technique. Vascular anastomosis patency after clinically successful repair was evaluated using the novel handheld OCT imager.With an adjustable lateral image field of view up to 1.5 mm by 1.5 mm, high-resolution simultaneous structural and flow imaging of the blood vessels were successfully acquired for BALB/C mouse after orthotopic hind limb transplantation using a non-suture cuff technique and BALB/C mouse after femoral artery anastomosis using a suture technique. We experimentally quantify the axial and lateral resolution of the OCT to be 12.6 µm in air and 17.5 µm respectively. The OCT has a sensitivity of 84 dB and sensitivity roll-off of 5.7 dB/mm over an imaging range of 5 mm. Imaging with a frame rate of 36 Hz for an image size of 1000(lateral×512(axial pixels using a 50,000 A-lines per second swept source was achieved. Quantitative vessel lumen patency, lumen narrowing and thrombosis analysis were performed based on acquired structure and Doppler images.A miniature handheld OCT imager that can be used for intraoperative evaluation of

  12. Esophagogastric anastomosis in rats: Improved healing by BPC 157 and L-arginine, aggravated by L-NAME. (United States)

    Djakovic, Zeljko; Djakovic, Ivka; Cesarec, Vedran; Madzarac, Goran; Becejac, Tomislav; Zukanovic, Goran; Drmic, Domagoj; Batelja, Lovorka; Zenko Sever, Anita; Kolenc, Danijela; Pajtak, Alen; Knez, Nikica; Japjec, Mladen; Luetic, Kresimir; Stancic-Rokotov, Dinko; Seiwerth, Sven; Sikiric, Predrag


    To cure typically life-threatening esophagogastric anastomosis in rats, lacking anastomosis healing and sphincter function rescue, in particular. Because we assume esophagogastric fistulas represent a particular NO-system disability, we attempt to identify the benefits of anti-ulcer stable gastric pentadecapeptide BPC 157, which was in trials for ulcerative colitis and currently for multiple sclerosis, in rats with esophagocutaneous fistulas. Previously, BPC 157 therapies have promoted the healing of intestinal anastomosis and fistulas, and esophagitis and gastric lesions, along with rescued sphincter function. Additionally, BPC 157 particularly interacts with the NO-system. In the 4 d after esophagogastric anastomosis creation, rats received medication (/kg intraperitoneally once daily: BPC 157 (10 μg, 10 ng), L-NAME (5 mg), or L-arginine (100 mg) alone and/or combined or BPC 157 (10 μg, 10 ng) in drinking water). For rats underwent esophagogastric anastomosis, daily assessment included progressive stomach damage (sum of the longest diameters, mm), esophagitis (scored 0-5), weak anastomosis (mL H2O before leak), low pressure in esophagus at anastomosis and in the pyloric sphincter (cm H2O), progressive weight loss (g) and mortality. Immediate effect assessed blood vessels disappearance (scored 0-5) at the stomach surface immediately after anastomosis creation. BPC 157 (all regimens) fully counteracted the perilous disease course from the very beginning (i.e., with the BPC 157 bath, blood vessels remained present at the gastric surface after anastomosis creation) and eliminated mortality. Additionally, BPC 157 treatment in combination with L-NAME nullified any effect of L-NAME that otherwise intensified the regular course. Consistently, with worsening (with L-NAME administration) and amelioration (with L-arginine), either L-arginine amelioration prevails (attenuated esophageal and gastric lesions) or they counteract each other (L-NAME + L-arginine); with the

  13. Comparison of three different pelvic circumferential compression devices: a biomechanical cadaver study.

    NARCIS (Netherlands)

    Knops, S.P.; Schep, N.W.; Spoor, C.W.; Riel, M.P. van; Spanjersberg, W.R.; Kleinrensink, G.J.; Lieshout, E.M. van; Patka, P.; Schipper, I.B.


    BACKGROUND: Pelvic circumferential compression devices are designed to stabilize the pelvic ring and reduce the volume of the pelvis following trauma. It is uncertain whether pelvic circumferential compression devices can be safely applied for all types of pelvic fractures because the effects of the

  14. Comparison of three different pelvic circumferential compression devices: A biomechanical cadaver study

    NARCIS (Netherlands)

    S.P. Knops (Simon); N.W.L. Schep (Niels); C.W. Spoor (Cornelis); M.P.J.M. Riel (Marcel); W.R. Spanjersberg (Willem); G.J. Kleinrensink (Gert Jan); E.M.M. van Lieshout (Esther); P. Patka (Peter); I.B. Schipper (Inger)


    textabstractBackground: Pelvic circumferential compression devices are designed to stabilize the pelvic ring and reduce the volume of the pelvis following trauma. It is uncertain whether pelvic circumferential compression devices can be safely applied for all types of pelvic fractures because the

  15. Comparison of three different pelvic circumferential compression devices: a biomechanical cadaver study

    NARCIS (Netherlands)

    Knops, S. P.; Schep, N. W. L.; Spoor, C. W.; van Riel, M. P. J. M.; Spanjersberg, W. R.; Kleinrensink, G. J.; van Lieshout, E. M. M.; Patka, P.; Schipper, I. B.


    Pelvic circumferential compression devices are designed to stabilize the pelvic ring and reduce the volume of the pelvis following trauma. It is uncertain whether pelvic circumferential compression devices can be safely applied for all types of pelvic fractures because the effects of the devices on

  16. Holomorphic Dynamics and Herman Rings

    DEFF Research Database (Denmark)

    Henriksen, Christian


    Existence theorem for Herman Rings of holomorphic mappings in a certain holomorphic family is given, using quasiconformal mappings. Proofs of topological properties of these Herman rings are given.......Existence theorem for Herman Rings of holomorphic mappings in a certain holomorphic family is given, using quasiconformal mappings. Proofs of topological properties of these Herman rings are given....

  17. Anastomosis Martin-Gruber: Aspectos anatómicos y electrofisiológicos Martin-Gruber Anastomosis: Anatomical and electrophysiological issues

    Directory of Open Access Journals (Sweden)

    Esperanza Herrera


    Full Text Available La anastomosis de Martin Gruber (AMG es una de las variaciones anatómicas más frecuentes que consiste en la contribución de axones motores desde el nervio mediano hacia el ulnar en el antebrazo. Factores filogenéticos y genéticos se asocian con la aparición de la AMG. Entre tanto, otros factores como género, raza o lateralidad no parecen tener importancia en la aparición de la rama comunicante. Las clasificaciones de la AMG han sido establecidas según los hallazgos anatómicos, electrofisiológicos e histológicos y también según el lugar de origen y destino de la anastomosis. El objetivo de este artículo es revisar los factores asociados a la presencia de la AMG, así como las descripciones y clasificaciones anatómicas y electrofisiológicas. Esta revisión aporta información relevante para el reconocimiento de los patrones clásico y variante de inervación de la musculatura intrínseca de la mano. Dicho reconocimiento permite diagnosticar e intervenir apropiadamente las alteraciones de los nervios periféricos de la extremidad superior. Salud UIS 2009; 41: 157-168The Martin Gruber Anastomosis (MGA is one of the most common anatomical variants of the upper limb, which consists of motor axons crossing through the forearm from the median nerve to the ulnar nerve. Phylogenetic and hereditary factors have been associated whit the MGA. However, gender, race, or laterality, do not seem to have importance in the appearance of the communicating branch. The MGA has been categorized according to findings in anatomy, electrophysiology and histology, in relation to the source and destination of the communicating branch. The aim of this article is to review the factors related to the presence of MGA, as well as the descriptions and classifications according to anatomy and electrophysiology. This revision contributes with important information relevant to the recognition of differences between the classic pattern and the variant pattern of the

  18. Schatzki ring, statistically reexamined. (United States)

    Pezzullo, John C; Lewicki, Ann M


    In the article by Schatzki published in 1963, data about the lower esophageal ring relate ring diameter to presence of dysphagia. Statistical analysis of these measurements was performed to quantify conclusions of Schatzki and to extract additional information from the data. Ring diameters in 332 patients with and without dysphagia are described in a histogram in the original article of Schatzki. Data were evaluated with analysis of variance, logistic regression, and receiver operating characteristic (ROC) analysis to quantify the relationship between ring diameter and dysphagia. Follow-up information was available in 36 symptomatic and 30 asymptomatic patients of Schatzki. Logistic regression indicated that there was a highly significant difference in ring diameter between the asymptomatic group and patients with recurrent dysphagia (P Schatzki had a 96% (104 of 108) sensitivity and a 58% (130 of 224) specificity, with area under the ROC curve of 0.888. Retrospective statistical analysis of original data of Schatzki validated his major conclusions about the data. Some important questions remain unanswered because of missing data in the study of Schatzki. Copyright RSNA, 2003

  19. Oligomeric ferrocene rings (United States)

    Inkpen, Michael S.; Scheerer, Stefan; Linseis, Michael; White, Andrew J. P.; Winter, Rainer F.; Albrecht, Tim; Long, Nicholas J.


    Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category—differently sized rings comprising only 1,1‧-disubstituted ferrocene units (cyclo[n], n = 5-7, 9). Due to the close proximity and connectivity of centres (covalent Cp-Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e- waves. Theoretical interrogations into correlations based on ring size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall ring charge and in conjunction with fast intramolecular electron transfer (˜107 s-1), these molecules can be considered as uniformly charged nanorings (diameter ˜1-2 nm).

  20. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  1. Den mindst ringe verdensorden

    DEFF Research Database (Denmark)

    Hansen, Birthe


    I 25 år har USA's styrkeposition og politik forsynet os med en 'verdensorden', der i et historisk perspektiv fremstår som den mindst ringe: fravær af store krige, mere demokrati, økonomisk fremgang - men dog også sammenbrudte stater og terrorisme.......I 25 år har USA's styrkeposition og politik forsynet os med en 'verdensorden', der i et historisk perspektiv fremstår som den mindst ringe: fravær af store krige, mere demokrati, økonomisk fremgang - men dog også sammenbrudte stater og terrorisme....

  2. Electrothermal Ring Burn

    Directory of Open Access Journals (Sweden)

    Yakup Çil


    Full Text Available Low-voltage fountainheads such as car, tractor or motorcycle batteries are predisposed to produce large currents. Any metal object that comes into contact with these batteries may result in short-circuit. This may result in rapid and excessive heating of metal object and an electrothermal burn. Herein we presented a motorcycle driver who was 28-year-old man with electrothermal ring burn which was caused by metal chain that was used as a ring. (Turk J Dermatol 2012; 6: 106-7

  3. Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire (United States)

    Rubincam, David Parry


    The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.

  4. Celiac Artery Compression Syndrome

    Directory of Open Access Journals (Sweden)

    Mohammed Muqeetadnan


    Full Text Available Celiac artery compression syndrome is a rare disorder characterized by episodic abdominal pain and weight loss. It is the result of external compression of celiac artery by the median arcuate ligament. We present a case of celiac artery compression syndrome in a 57-year-old male with severe postprandial abdominal pain and 30-pound weight loss. The patient eventually responded well to surgical division of the median arcuate ligament by laparoscopy.

  5. Wavelet image compression

    CERN Document Server

    Pearlman, William A


    This book explains the stages necessary to create a wavelet compression system for images and describes state-of-the-art systems used in image compression standards and current research. It starts with a high level discussion of the properties of the wavelet transform, especially the decomposition into multi-resolution subbands. It continues with an exposition of the null-zone, uniform quantization used in most subband coding systems and the optimal allocation of bitrate to the different subbands. Then the image compression systems of the FBI Fingerprint Compression Standard and the JPEG2000 S

  6. Compressed sensing & sparse filtering

    CERN Document Server

    Carmi, Avishy Y; Godsill, Simon J


    This book is aimed at presenting concepts, methods and algorithms ableto cope with undersampled and limited data. One such trend that recently gained popularity and to some extent revolutionised signal processing is compressed sensing. Compressed sensing builds upon the observation that many signals in nature are nearly sparse (or compressible, as they are normally referred to) in some domain, and consequently they can be reconstructed to within high accuracy from far fewer observations than traditionally held to be necessary. Apart from compressed sensing this book contains other related app

  7. Alcohol acute intoxication before sepsis impairs the wound healing of intestinal anastomosis: rat model of the abdominal trauma patient

    Directory of Open Access Journals (Sweden)

    Morais Pedro


    Full Text Available Abstract Introduction Most trauma patients are drunk at the time of injury. Up to 2% of traumatized patients develop sepsis, which considerably increases their mortality. Inadequate wound healing of the colonic repair can lead to postoperative complications such as leakage and sepsis. Objective To assess the effects of acute alcohol intoxication on colonic anastomosis wound healing in septic rats. Methods Thirty six Wistar rats were allocated into two groups: S (induction of sepsis and AS (alcohol intake before sepsis induction. A colonic anastomosis was performed in all groups. After 1, 3 or 7 days the animals were killed. Weight variations, mortality rate, histopathology and tensile breaking strength of the colonic anastomosis were evaluated. Results There was an overall mortality of 4 animals (11.1%, three in the group AS (16.6% and one in the S group (5.5%. Weight loss occurred in all groups. The colon anastomosis of the AS group didn’t gain strength from the first to the seventh postoperative day. On the histopathological analysis there were no differences in the deposition of collagen or fibroblasts between the groups AS and S. Conclusion Alcohol intake increased the mortality rate three times in septic animals. Acute alcohol intoxication delays the acquisition of tensile strength of colonic anastomosis in septic rats. Therefore, acute alcohol intoxication before sepsis leads to worse prognosis in animal models of the abdominal trauma patients.

  8. A single surgeon's experience transitioning to robotic-assisted right colectomy with intracorporeal anastomosis. (United States)

    Reitz, Alexandra C W; Lin, Ed; Rosen, Seth A


    Despite substantial evidence demonstrating benefits of minimally invasive surgery, a large percentage of right colectomies are still performed via an open technique. Most laparoscopic right colectomies are completed as a hybrid procedure with extracorporeal anastomosis. As part of a pure minimally invasive procedure, intracorporeal anastomosis (ICA) may confer additional benefits for patients. The robotic platform may shorten the learning curve for minimally invasive right colectomy with ICA. From January 2014 to May 2016, 49 patients underwent robotic-assisted right colectomy by a board-certified colorectal surgeon (S.R). Extracorporeal anastomosis (ECA) was used in the first 20 procedures, whereas ICA was used in all subsequent procedures. Outcomes recorded in a database for retrospective review included operating time (OT), estimated blood loss (EBL), length of stay (LOS), conversion rate, complications, readmissions, and mortality rate. Comparison of average OT, EBL, and LOS between extracorporeal and intracorporeal groups demonstrated no significant differences. For all patients, average OT was 141.6 ± 25.8 (range 86-192) min, average EBL was 59.5 ± 83.3 (range 0-500) mL, and average LOS was 3.4 ± 1.19 (range 1.5-8) days. Four patients required conversion, all of which occurred in the extracorporeal group. There were no conversions after the 18th procedure. The 60-day mortality rate was 0%. There were no anastomotic leaks, ostomies created, or readmissions. As the surgeon gained experience, a statistically significant increase in lymph node sampling was observed in oncologic cases (p = .02). The robotic platform may help more surgeons safely and efficiently transition to a purely minimally invasive procedure, enabling more patients to reap the benefits of less invasive surgery. Transitioning from ECA to ICA during robotic right colectomy resulted in no significant change in OT or LOS. A lower rate of conversion to open surgery was noted with

  9. Effect of beta blocker combined with COX-2 inhibitor on colonic anastomosis in rats. (United States)

    Benjamin, Barak; Hazut, Ofir; Shaashua, Lee; Benish, Marganit; Zmora, Niv; Barshack, Iris; Hoffman, Aviad; Ben-Eliyahu, Shamgar; Zmora, Oded


    Pharmacologic modulation of the perioperative physiologic stress response, using the beta-blocker propranolol, combined with the COX-2 inhibitor etodolac, has been shown to reduce metastatic spread and increase survival rates following surgery for primary tumor excision in rodents. Prior to implantation of this pharmacological approach in clinical trials in patients with colon cancer, the safety of this technique has to be evaluated. This study assessed the effects of these drugs on the healing of colonic anastomosis in rats. Forty-eight F344 rats were divided into two groups, which were given seven daily subcutaneous injections of either vehicle, or propranolol (up to 1.2 mg/kg/day) combined with etodolac (12.5 mg/kg/day), starting the day before surgery. Each animal underwent laparotomy, colotomy of the descending colon, and anastomosis. Anastomotic leak rate and bursting pressure were compared at 1 week after the operation. The harvested anastomosis was histologically assessed for wound healing parameters. Forty-three rats survived the operation and were eligible for analysis at 1 week. No significant difference in survival, anastomotic leakage, or bursting pressure was found between animals that received propranolol and etodolac versus those receiving vehicle (drugs 179 mmHg ± 45.4; vehicle 187 mmHg, SD ± 35.0, p = 0.54). Histologic assessment of fibrosis, necrosis, cell infiltration, and tissue reaction zone did not differ between the two groups. Perioperative administration of propranolol and etodolac seems safe in colon operations in rats and does not affect anastomotic failure or colon healing.

  10. Storage Ring EDM Experiments

    Directory of Open Access Journals (Sweden)

    Semertzidis Yannis K.


    Full Text Available Dedicated storage ring electric dipole moment (EDM methods show great promise advancing the sensitivity level by a couple orders of magnitude over currently planned hadronic EDM experiments. We describe the present status and recent updates of the field.

  11. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina


    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...... functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also compute the fu- sion rings for type G2....

  12. Parks' coloanal sleeve anastomosis for treatment of postirradiation rectovaginal fistula

    Energy Technology Data Exchange (ETDEWEB)

    Nowacki, M.P.; Szawlowski, A.W.; Borkowski, A.


    Postirradiation rectovaginal fistula is a complex problem in colorectal surgery. The modified Parks procedure curettage of rectal mucosa heavily damaged by radiation is introduced. Fifteen cases of coloanal sleeve anastomosis for the repair of rectovaginal postirradiation fistula are described. All patients previously were irradiated heavily because of carcinoma of the uterine cervix. Three patients had simultaneous repair of vesicovaginal fistula. One postoperative death was observed. Of the surviving patients, functional results have been good in 11. In the seven patients with difficult stripping of the rectal mucosa, surgical curettage was performed. The latter procedure is suggested as the method of choice in relevant cases.

  13. Vascularized Lymph Node Flap Transfer and Lymphovenous Anastomosis for Klippel-Trenaunay Syndrome with Congenital Lymphedema

    Directory of Open Access Journals (Sweden)

    Shan Shan Qiu, MD


    Full Text Available Summary: A female patient with Klippel-Trenaunay syndrome, including hypertrophic bone and soft tissue in the forelimbs, bilateral lower limbs lymphedema, port-wine stains, and superficial veins of Servelle, was presented. The diagnosis of lymphedema was confirmed by lymphoscintigraphy and indocyanine green lymphography. The novel treatments consisted of vascularized lymph node transplantation to the left lymphedematous extremity and lymphovenous anastomosis to the right lymphedematous extremity. Significant improvements in subjective and objective clinical outcome were observed early in the postoperative period with continued improvements during the follow-up period.

  14. Vólvulo de sigmoides: Resección y anastomosis primaria, resultados

    Directory of Open Access Journals (Sweden)

    Juan Manuel Fajes Alfonso


    Full Text Available Se intervinieron quirúrgicamente 12 pacientes por vólvulo del sigmoides. Se les realizó la resección de éste y la anastomosis primaria término-terminal sin previa preparación del colon. En el 58 % de los pacientes se usó drenaje de la cavidad abdominal, en el resto no. Dos enfermos, (16,6 % presentaron sepsis de la herida como complicación posoperatoria. La mortalidad fue del 8,3 %

  15. Ovarian cancer mimicking recurrence at colorectal anastomosis: report of a case.

    LENUS (Irish Health Repository)

    Reardon, C M


    PURPOSE: The aim of this article is to emphasize the increased risk of developing metachronous ovarian tumors after resection of rectal cancer. METHOD AND RESULTS: We report the case of a postmenopausal female patient who, five years after anterior resection, developed a primary ovarian malignancy that invaded a rectal anastomosis and in so doing mimicked a recurrence of a Dukes A rectal cancer. To our knowledge, such an occurrence has not been described previously in the literature. CONCLUSION: This case illustrates the possible benefits of routine prophylactic oophorectomy at the time of colorectal cancer resection.

  16. Ring Bubbles of Dolphins (United States)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)


    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  17. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.


    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...... navigational queries directly on the compressed representation. We show that the new compression scheme achieves close to optimal worst-case compression, can compress exponentially better than DAG compression, is never much worse than DAG compression, and supports navigational queries in logarithmic time....

  18. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.


    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...... navigational queries directly on the compressed representation. We show that the new compression scheme achieves close to optimal worst-case compression, can compress exponentially better than DAG compression, is never much worse than DAG compression, and supports navigational queries in logarithmic time....

  19. Saturn ring temperature changes before and after ring equinox (United States)

    Spilker, Linda; Flandes, Alberto; Morishima, Ryuji; Leyrat, Cedric; Altobelli, Nicolas; Ferrari, Cecile; Brooks, Shawn; Pilorz, Stu


    The Cassini Composite infrared spectrometer (CIRS) retrieved the temperatures of Saturn's main rings at solar elevations ranging from 24 degrees to zero degrees at equinox (August 2009) as the sun traversed from the south to north side of the rings. Over this broad range of solar elevation the CIRS data show that the ring temperatures vary as much as 29K- 38K for the A ring, 22K-34K for the B ring and 18K-23K for the C ring. Interestingly the unlit sides of the rings show a similar decrease in temperature with the decreasing solar elevation. As equinox approached, the main rings cooled to their lowest temperatures measured to date. At equinox the solar input is very small and the primary heat sources for the rings are Saturn thermal and visible energy. Temperatures are almost identical for similar geometries on the north and south sides of the rings. The ring temperatures at equinox were: C ring, 55-75 K; B ring, 45-60 K; Cassini Division, 45 - 58 K; and A ring, 43 - 52 K. After Saturn equinox the solar elevation angle began to increase again and the temperatures on both the lit (north) and unlit (south) sides of the rings have begun to increase as well. Ring thermal models developed by Flandes and Morishima are able to reproduce most of the equinox temperatures observed by CIRS. Results before and after equinox will be presented. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and at CEA Saclay supported by the "Programme National de Planetologie". Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  20. Anisotropic Concrete Compressive Strength

    DEFF Research Database (Denmark)

    Gustenhoff Hansen, Søren; Jørgensen, Henrik Brøner; Hoang, Linh Cao


    When the load carrying capacity of existing concrete structures is (re-)assessed it is often based on compressive strength of cores drilled out from the structure. Existing studies show that the core compressive strength is anisotropic; i.e. it depends on whether the cores are drilled parallel...

  1. Experiments with automata compression

    NARCIS (Netherlands)

    Daciuk, J.; Yu, S; Daley, M; Eramian, M G


    Several compression methods of finite-state automata are presented and evaluated. Most compression methods used here are already described in the literature. However, their impact on the size of automata has not been described yet. We fill that gap, presenting results of experiments carried out on

  2. Role of plastic surgeons in hepatic artery anastomosis in living donor liver transplantation: our experience of 10 cases. (United States)

    Mangal, Mahesh; Gambhir, Swaroop; Gupta, Anubhav; Shah, Amiti


    To understand the practical difficulties encountered while performing hepatic artery anastomosis by microsurgical technique in living donor liver transplantation. We undertook a retrospective study of 10 cases of hepatic artery anastomosis done at the level of bifurcation of the right hepatic artery and proximal when the plastic surgery team was called in for assistance. All the anastomoses were performed under an operating microscope (up to 24× magnification). In seven of these cases, anterior wall anastomosis was performed primarily, and in three cases, posterior wall approach was chosen. The main indications of calling in the plastic surgery team were to overcome these technical hurdles: (1) in cases where the caliber of the vessel was less than 2 mm in size; (2) dissection (separation of mucosa and adventitia) of the recipient vessel wall; (3) donor pedicle being so short that possibility of revision of the anastomosis seemed unlikely, necessitating single, sure-shot anastomosis without a chance of revision. The problems encountered by our microsurgical team were: (1) a special set of instruments was warranted because of the depth of the hepatic artery; (2) anastomosis had to be done in standing, stooped position with unsupported hands; (3) excessive movements due to respiration and profuse fluid collection in the field added to the hurdles encountered. All patients were prospectively followed by color Doppler ultrasound protocol for the first 5 days after surgery. Hepatic artery thrombosis was encountered in one case on postoperative day 10, which was successfully treated by thrombolytic therapy, but unfortunately the patient died of multiorgan failure on posttransplant day 30. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Evaluation of a novel thermosensitive heparin-poloxamer hydrogel for improving vascular anastomosis quality and safety in a rabbit model.

    Directory of Open Access Journals (Sweden)

    Ying-Zheng Zhao

    Full Text Available Despite progress in the design of advanced surgical techniques, stenosis recurs in a large percentage of vascular anastomosis. In this study, a novel heparin-poloxamer (HP hydrogel was designed and its effects for improving the quality and safety of vascular anastomosis were studied. HP copolymer was synthesized and its structure was confirmed by Fourier transform infrared spectroscopy (FTIR and nuclear magnetic resonance spectroscopy ((1H-NMR. Hydrogels containing HP were prepared and their important characteristics related to the application in vascular anastomosis including gelation temperature, rheological behaviour and micromorphology were measured. Vascular anastomosis were performed on the right common carotid arteries of rabbits, and the in vivo efficiency and safety of HP hydrogel to achieve vascular anastomosis was verified and compared with Poloxamer 407 hydrogel and the conventional hand-sewn method using Doppler ultrasound, CT angiograms, scanning electron microscopy (SEM and histological technique. Our results showed that HP copolymer displayed special gel-sol-gel phase transition behavior with increasing temperature from 5 to 60 °C. HP hydrogel prepared from 18 wt% HP solution had a porous sponge-like structure, with gelation temperature at approximately 38 °C and maximum elastic modulus at 10,000 Pa. In animal studies, imaging and histological examination of rabbit common jugular artery confirmed that HP hydrogel group had similar equivalent patency, flow and burst strength as Poloxamer 407 group. Moreover, HP hydrogel was superior to poloxamer 407 hydrogel and hand-sewn method for restoring the functions and epithelial structure of the broken vessel junctions after operation. By combining the advantages of heparin and poloxamer 407, HP hydrogel holds high promise for improving vascular anastomosis quality and safety.

  4. Inorganic glass ceramic slip rings (United States)

    Glossbrenner, E. W.; Cole, S. R.


    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  5. Ex vivo proof-of-concept of end-to-end scaffold-enhanced laser-assisted vascular anastomosis of porcine arteries

    NARCIS (Netherlands)

    Pabittei, Dara R.; Heger, Michal; van Tuijl, Sjoerd; Simonet, Marc; de Boon, Wadim; van der Wal, Allard C.; Balm, Ron; de Mol, Bas A.


    The low welding strength of laser-assisted vascular anastomosis (LAVA) has hampered the clinical application of LAVA as an alternative to suture anastomosis. To improve welding strength, LAVA in combination with solder and polymeric scaffolds (ssLAVA) has been optimized in vitro. Currently, ssLAVA

  6. A No-Reference Sharpness Metric Based on Structured Ringing for JPEG2000 Images

    Directory of Open Access Journals (Sweden)

    Zhipeng Cao


    Full Text Available This work presents a no-reference image sharpness metric based on human blur perception for JPEG2000 compressed image. The metric mainly uses a ringing measure. And a blurring measure is used for compensation when the blur is so severe that ringing artifacts are concealed. We used the anisotropic diffusion for the preliminary ringing map and refined it by considering the property of ringing structure. The ringing detection of the proposed metric does not depend on edge detection, which is suitable for high degraded images. The characteristics of the ringing and blurring measures are analyzed and validated theoretically and experimentally. The performance of the proposed metric is tested and compared with that of some existing JPEG2000 sharpness metrics on three widely used databases. The experimental results show that the proposed metric is accurate and reliable in predicting the sharpness of JPEG2000 images.

  7. Damping Ring R&D at CESR-TA

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, David L. [Cornell Univ., Ithaca, NY (United States). Dept. of Physics


    Accelerators that collide high energy beams of matter and anti-matter are essential tools for the investigation of the fundamental constituents of matter, and the search for new forms of matter and energy. A “Linear Collider” is a machine that would bring high energy and very compact bunches of electrons and positrons (anti-electrons) into head-on collision. Such a machine would produce (among many other things) the newly discovered Higgs particle, enabling a detailed study of its properties. Among the most critical and challenging components of a linear collider are the damping rings that produce the very compact and intense beams of electrons and positrons that are to be accelerated into collision. Hot dilute particle beams are injected into the damping rings, where they are compressed and cooled. The size of the positron beam must be reduced more than a thousand fold in the damping ring, and this compression must be accomplished in a fraction of a second. The cold compact beams are then extracted from the damping ring and accelerated into collision at high energy. The proposed International Linear Collider (ILC), would require damping rings that routinely produce such cold, compact and intense beams. The goal of the Cornell study was a credible design for the damping rings for the ILC. Among the technical challenges of the damping rings; the development of instrumentation that can measure the properties of the very small beams in a very narrow window of time, and mitigation of the forces that can destabilize the beams and prevent adequate cooling, or worse lead to beam loss. One of the most pernicious destabilizing forces is due to the formation of clouds of electrons in the beam pipe. The electron cloud effect is a phenomenon in particle accelerators in which a high density of low energy electrons, build up inside the vacuum chamber. At the outset of the study, it was anticipated that electron cloud effects would limit the intensity of the positron ring

  8. Ring closure in actin polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Supurna, E-mail: [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)


    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

  9. The "Sun window" - a simple and effective alternative to the use of background contrast material during microvascular anastomosis. (United States)

    Sun, Tzong-Bor; Hsu, Lee-Ping; Chen, Peir-Rong


    A new and simple alternative method, the "Sun window," is introduced for creating a comfortable environment while doing microvascular anastomoses. A prospective randomized study, analyzing the anastomosis time for 34 free radial forearm flaps, was conducted to validate the effectiveness of this method. The time required for doing anastomoses with and without a "Sun window" are 8.74 +/- 1.46 and 10.36 +/- 1.20, respectively, p Sun window" is an effective method for promoting the patency rate and accuracy of microvascular anastomosis.

  10. Anastomotic salvage after rectal cancer resection using the Turnbull-Cutait delayed anastomosis. (United States)

    Hallet, Julie; Bouchard, Alexandre; Drolet, Sébastien; Milot, Hélène; Desrosiers, Emilie; Lebrun, Aude; Grégoire, Roger Charles


    Turnbull-Cutait abdominoperineal pull-through followed by delayed coloanal anastomosis (DCA) was first described in 1961. Studies have described its use for challenging colorectal conditions. We reviewed our experience with Turnbull-Cutait DCA as a salvage procedure for complex failure of colorectal anastomosis. We performed a retrospective cohort study from October 2010 to September 2011, with analysis of postoperative morbidity and mortality. Seven DCAs were performed for anastomotic complications (3 chronic leaks, 2 rectovaginal fistulas, 1 colovesical fistula, 1 colonic ischemia) following surgery for rectal cancer. Six patients had a diverting ileostomy constructed as part of previous treatment for anastomotic complications before the salvage procedure. No anastomotic leaks were observed. All procedures but 1 were completed successfully. One patient who underwent DCA subsequently required an abdominoperineal resection and a permanent colostomy for postoperative extensive colonic ischemia. No 30-day mortality occurred. Salvage Turnbull-Cutait DCA appears to be a safe procedure and could be offered to patients with complex anastomotic complications. This procedure could be added to the surgeon's armamentarium as an alternative to the creation of a permanent stoma.

  11. Bricker's ileal conduit urinary diversion with a simple non-refluxing uretero ileal anastomosis

    DEFF Research Database (Denmark)

    Bernstein, I T; Bennicke, K; Rørdam, P


    Fifty consecutive patients had ileal conduits constructed with a technically and quick simple antireflux ureteroileal anastomosis. Complications related to the ureteral implantation were studied retrospectively, and at follow-up (8 months-12 years later, median 3 years) conduit dysfunction and ur...... from 300 to 420 mumol/l. Partial ureteral reflux was present in three (2 patients) of 33 ureters studied and minimal conduit dysfunction was found in 8 patients. In conclusion we find this method of urinary diversion to be quick, easy, and safe.......Fifty consecutive patients had ileal conduits constructed with a technically and quick simple antireflux ureteroileal anastomosis. Complications related to the ureteral implantation were studied retrospectively, and at follow-up (8 months-12 years later, median 3 years) conduit dysfunction...... and ureteral reflux were assessed in 18 patients out of the 25 patients who were still alive. Early complications and signs of late upper urinary tract deterioration were similar to those found after other operative techniques had been used. One patient had a postoperative urinary leak from the uretero ileal...

  12. Is it safe to perform rectal anastomosis in gynaecological debulking surgery without a diverting stoma? (United States)

    Reinisch, A; El-Balat, A; Becker, S; Bechstein, W O; Habbe, N


    Colorectal resection is frequently performed during cytoreductive surgery for gynaecological malignancy. The aim of this study was to assess the safety of colorectal anastomosis, and especially low rectal anastomosis, in the absence of a protective stoma in patients with gynaecological cancer and peritoneal metastasis. Patient data were retrospectively collected from a database for gynaecological cancer procedures carried out between January 2013 and July 2015. All patients who underwent a colorectal resection during cytoreduction were included in the study. The primary outcome was anastomotic leakage in the presence or absence of a diverting stoma. Secondary outcome parameters were complications and reoperations. In the period of study, 43 major colorectal procedures were performed on 37 women. The most common colorectal procedure was low rectal resection (n = 22; 59%) followed by anterior rectal resection (n = 7; 19%) and sigmoid resection (n = 4; 11%). Five (14%) patients underwent Hartmann's procedure. In three (8%) patients, a diverting loop ileostomy was created. Low rectal resection during debulking procedures for gynaecological cancers with peritoneal carcinomatosis can safely be performed by an experienced surgeon without a diverting stoma. Colorectal Disease © 2016 The Association of Coloproctology of Great Britain and Ireland.

  13. Tyrolean tensiometer: a new instrument for easy intraoperative tension measurement before vascular anastomosis. (United States)

    Schubert, Heinrich M; Hohlrieder, Matthias; Buchegger, Johannes W; Brodbeck, Achim F; Hager, Martina; Zimmermann, Robert F; Moser, Thomas M


    In reconstructive surgery microsurgical repair of dissected arteries sometimes has to be done under longitudinal tension. Guidelines to support an objective decision on whether tension associated with direct suture is acceptable or whether grafting is needed, do not exist. All experimental data found concerned the clinical outcome of a certain length defect treated in various animal models. The aim of this study was to show the feasibility of a new instrument for measuring the tension required to adapt arterial stumps, thereby allowing surgical outcome to be assessed before beginning anastomosis. A modified tension spring balance was used to measure the force applied to the arterial stumps before knotting. Twenty-four rat femoral arteries were dissected, segments of up to 9mm were resected, and the tension needed for approximation was measured. These ex-vivo data were combined with clinical outcome data of previous animal trials. The tension measured increased proportionally to the size of the arterial gap created. The correlation between tension and arterial gap was found to be almost linear. The average additional time required for tension measurement using the Tyrolean Tensiometer was 13 (+/-6) s. High anastomotic tension may cause critical or even poor clinical outcome. None of the tension measurement methods described so far allow intraoperative measurement at a time when changes in strategy are still possible. The Tyrolean Tensiometer for the first time allows fast and reliable measurement of the tension acting on the first suture of an anastomosis.

  14. Compression fractures of the back (United States)

    ... most effective way to prevent compression or insufficiency fractures. Getting regular load-bearing exercise (such as walking) can help you avoid bone loss. Alternative Names Vertebral compression fractures Images Compression fracture References Cosman F, de Beur ...

  15. O-Ring-Testing Fixture (United States)

    Turner, James E.; Mccluney, D. Scott


    Fixture used to evalute properties of O-rings of various materials. Hydraulic actuator positions plug in housing, creating controlled, variable gap in O-ring glands formed by grooves in plug and by inner wall of housing. Creates controlled axial and radial gaps between sealing surfaces around ring so effectiveness of material in maintaining seal determined under dynamic conditions.

  16. Clean elements in abelian rings

    Indian Academy of Sciences (India)

    equivalent to being clean for an abelian ring is 'topologically boolean'. In line with [1] we say that a ring R (not necessarily commutative) is right (resp. left) topologically boolean, or a right (resp. left) tb-ring for short, if for every pair of distinct maximal right (resp. left) ideals of R there is an idempotent in exactly one of them.

  17. Ring closure in actin polymers


    Sinha, Supurna; Chattopadhyay, Sebanti


    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments.We also discuss the effect of ring closure on bend angle fluctuations in actin polymers.

  18. Non-Commutative Ring Theory

    CERN Document Server

    López-Permouth, Sergio


    The papers of this volume share as a common goal the structure and classi- fication of noncommutative rings and their modules, and deal with topics of current research including: localization, serial rings, perfect endomorphism rings, quantum groups, Morita contexts, generalizations of injectivitiy, and Cartan matrices.

  19. Compressive Properties and Anti-Erosion Characteristics of Foam Concrete in Road Engineering (United States)

    Li, Jinzhu; Huang, Hongxiang; Wang, Wenjun; Ding, Yifan


    To analyse the compression properties and anti-erosion characteristics of foam concrete, one dimensional compression tests were carried out using ring specimens of foam concrete, and unconfined compression tests were carried out using foam concrete specimens cured in different conditions. The results of one dimensional compression tests show that the compression curve of foam concrete has two critical points and three stages, which has significant difference with ordinary geotechnical materials such as soil. Based on the compression curve the compression modulus of each stage were determined. The results of erosion tests show that sea water has a slight influence on the long-term strength of foam concrete, while the sulphate solution has a significant influence on the long-term strength of foam concrete, which needs to pay more attention.

  20. Saturn Ring Observer (United States)

    Spilker, T. R.


    Answering fundamental questions about ring particle characteristics, and individual and group behavior, appears to require close-proximity (a few km) observations. Saturn's magnificent example of a ring system offers a full range of particle sizes, densities, and behaviors for study, so it is a natural choice for such detailed investigation. Missions implementing these observations require post-approach Delta(V) of approximately 10 km/s or more, so past mission concepts called upon Nuclear Electric Propulsion. The concept described here reduces the propulsive Delta(V) requirement to as little as 3.5 km/s, difficult but not impossible for high-performance chemical propulsion systems. Additional information is contained in the original extended abstract.

  1. Satellite Rings Movie (United States)


    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000.Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  2. Eficacitatea combaterii larvelor de Clostera anastomosis L. la ieșirea din hibernare [Treatment efficacy of Clostera anastomosis L. caterpillars control in postdormancy phase

    Directory of Open Access Journals (Sweden)

    Duduman Mihai-Leonard


    Full Text Available Clostera anastomosis is an important poplar and willow defoliator which, especially since 1950, caused important damages to intensive hybrid poplar crops in Europe and Asia. The need to reduce the loss caused by this insect, often led to radical control tactics, consisting in spraying chemical insecticides with low specificity and high impact on biodiversity. Other control methods (biological control had not the expected effect. Considering the above mentioned aspects and the fact that C. anastomosis overwinters as larvae, mainly in bark crevices of the stems of infested trees, it was tested the possibility of controlling this pest, by chemical control of the larvae, early in spring. There were designed two trials in lab and in field, in order to test the efficacy of 5 insecticides [Proteus (thiacloprid + deltamethrin, Ovipron (horticultural oil, Nuprid (imidacloprid, Confidor (imidacloprid and Karate Zeon (lambda-cyhalothin], sprayed directly on the stem of the poplar trees colonized with overwintering larvae nests. The treatment efficacy was assessed based on the survival rate of larvae after chemical spraying, by comparing it to the control samples. All surviving larvae were trapped in sticky barriers placed around the stems, above the sprayed area. Of the tested insecticides, the most efficient was Confidor, causing mortality of the 90.2 ± 1.8% of the larvae, significantly higher than the rest of the tested insecticides (Proteus, Ovipron, Nuprid. In field conditions, Confidor caused the decrease of the larvae population with 78.2 ± 7.4% for poplar clone AF2, and with 92.9 ± 6.4% for poplar clone AF8, and Karate Zeon caused 100% mortality. Control of the larvae in spring was efficient. It is a matter of course that this control method will have a lower environmental impact due to both the application moment (early spring, before poplars flush, and high control of the sprayed area (only the lower section of the infested tree stems

  3. Eelgrass fairy rings

    DEFF Research Database (Denmark)

    Borum, Jens; Raun, Ane-Marie Løvendahl; Hasler-Sheetal, Harald


    Distinct ‘fairy rings’ consisting of narrow fringes of eelgrass (Zostera marina l.) expand radially over a bottom of chalk plates outside the calcium carbon- ate cliffs of the island of Møn, Denmark. We conducted a survey to evaluate possible explanations for the formation of the rings and, more...... sulfide accumulating in the sediment due to low iron availability in the carbonate-rich environment....

  4. Uranus rings and two moons (United States)


    Voyager 2 has discovered two 'shepherd' satellites associated with the rings of Uranus. The two moons -- designated 1986U7 and 1986U8 -- are seen here on either side of the bright epsilon ring; all nine of the known Uranian rings are visible. The image was taken Jan. 21, 1986, at a distance of 4.1 million kilometers (2.5 million miles) and resolution of about 36 km (22 mi). The image was processed to enhance narrow features. The epsilon ring appears surrounded by a dark halo as a result of this processing; occasional blips seen on the ring are also artifacts. Lying inward from the epsilon ring are the delta, gamma and eta rings; then the beta and alpha rings; and finally the barely visible 4, 5 and 6 rings. The rings have been studied since their discovery in 1977, through observations of how they diminish the light of stars they pass in front of. This image is the first direct observation of all nine rings in reflected sunlight. They range in width from about 100 km (60 mi) at the widest part of the epsilon ring to only a few kilometers for most of the others. The discovery of the two ring moons 1986U7 and 1986U8 is a major advance in our understanding of the structure of the Uranian rings and is in good agreement with theoretical predictions of how these narrow rings are kept from spreading out. Based on likely surface brightness properties, the moons are of roughly 2O- and 3O-km diameter, respectively. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  5. Two-stage Turnbull-Cutait pull-through coloanal anastomosis versus coloanal anastomosis with protective loop ileostomy for low rectal cancer. Protocol for a randomized controlled trial (Turnbull-BCN). (United States)

    Biondo, Sebastiano; Trenti, Loris; Galvez, Ana; Espin-Basany, Eloy; Bianco, Francesco; Romano, Giovanni; Kreisler, Esther


    The aim of this study was to determine whether patients that underwent ultra-low rectal resection for cancer can benefit from the recently reintroduced two-stage Turnbull-Cutait abdominoperineal pull-through procedure. Patients with low rectal tumors undergoing radical sphincter-sparing resection are eligible for inclusion in a randomized multicenter study. Whether two-stage Turnbull-Cutait coloanal anastomosis provides significant benefits over hand-sewn coloanal anastomosis and associated lateral ileostomy in terms of postoperative morbidity is the primary endpoint. In addition, the study aims to assess secondary endpoints such as quality of life, fecal incontinence, and locoregional recurrence of the neoplasm. Patients with adenocarcinoma of the lower rectum diagnosed by rigid proctoscopy, with histological confirmation of malignancy, and who are candidates of rectal removal and coloanal anastomosis will be included in a randomized controlled and multicenter trial. Postoperative morbidity is defined as complications that occur within 30 days of the data of the second surgical procedure of the last patient included in the trial. Patients will be followed for a minimum period of 3 years. The two-stage Turnbull-Cutait coloanal anastomosis may constitute an effective surgical alternative in the current approach to the treatment of low rectal cancer without the need of a temporary loop colostomy, preventing the wide range of complications related to stoma surgery. This trial is registered at (trial number: NCT01766661). This trial is registered in January 10, 2013.

  6. Mass of Saturn's A ring (United States)

    Horn, L. J.; Russell, C. T.


    The mass of Saturn's A ring is reestimated using the behavior of spiral density waves embedded in the ring. The Voyager photopolarimeter (PPS) observed the star delta-Scorpii as it was occulted by Saturn's rings during the Voyager 2 flyby of Saturn in 1981 producing a radial profile of the rings. We examined forty spiral density waves in the Voyager PPS data of the A ring including 10 weaker waves that have not been previously analyzed by means of an autoregressive power spectral technique called Burg. The strengths of this new method for ring studies are that weaker, less extended waves are easily detected and characterized. This method is also the first one which does not require precise knowledge of the resonance location and phase of the wave in order to calculate the surface mass density. Uncertainties of up to 3 km are present in the currently available radial scales for Saturn's rings.

  7. Arcuate ligament compression as a cause of early-onset thrombosis of the hepatic artery after liver transplantation. (United States)

    Vilatobá, Mario; Zamora-Valdés, Daniel; Guerrero-Hernández, Manuel; Romero-Talamás, Héctor; Leal-Villalpando, Rafael P; Mercado, Miguel A


    Early hepatic artery thrombosis (HAT) is a potentially lethal complication after orthotopic liver transplantation (OLT) requiring immediate intervention. To report an infrequent cause of HAT after OLT and by itself a controversial clinical entity, the median arcuate ligament celiac artery compression. A 59-year-old female with hepatitis C virus-induced cirrhosis, Child B, MELD 15, underwent cadaveric-donor OLT with complete vena cava exclusion. Type 1 hepatic artery anatomy was found both in the donor and the recipient, the gastroduodenal artery was ligated. During the first eight postoperative days, clinical and analytical evolution was satisfactory and Doppler ultrasound showed no abnormalities. On the ninth postoperative day, the patient developed hypovolemic shock due to bleeding at the hepatic artery anastomosis, surgical reconstruction was performed. Postoperative color Doppler showed absent hepatic artery flow and an angiography suggested celiac artery compression. The patient was explored again the same day, liberating the celiac artery from the median arcuate ligament and performing thrombectomy and reconstruction of the hepatic artery anastomosis. The patient made a satisfactory recovery and color Doppler showed adequate flow in the hepatic artery. She is alive, free of biliary complications and enjoying a good quality of life 12 months after transplantation. Median arcuate ligament celiac artery compression is an infrequent anatomical variant that should be intentionally evaluated in the recipient at the time of arterial reconstruction in OLT and specifically be considered in early HAT to allow recognition and effective correction.

  8. Compressed Video Segmentation

    National Research Council Canada - National Science Library

    Kobla, Vikrant; Doermann, David S; Rosenfeld, Azriel


    ... changes in content and camera motion. The analysis is performed in the compressed domain using available macroblock and motion vector information, and if necessary, discrete cosine transform (DCT) information...

  9. Compressive light field displays. (United States)

    Wetzstein, Gordon; Lanman, Douglas; Hirsch, Matthew; Heidrich, Wolfgang; Raskar, Ramesh


    Light fields are the multiview extension of stereo image pairs: a collection of images showing a 3D scene from slightly different perspectives. Depicting high-resolution light fields usually requires an excessively large display bandwidth; compressive light field displays are enabled by the codesign of optical elements and computational-processing algorithms. Rather than pursuing a direct "optical" solution (for example, adding one more pixel to support the emission of one additional light ray), compressive displays aim to create flexible optical systems that can synthesize a compressed target light field. In effect, each pixel emits a superposition of light rays. Through compression and tailored optical designs, fewer display pixels are necessary to emit a given light field than a direct optical solution would require.

  10. Reference Based Genome Compression

    CERN Document Server

    Chern, Bobbie; Manolakos, Alexandros; No, Albert; Venkat, Kartik; Weissman, Tsachy


    DNA sequencing technology has advanced to a point where storage is becoming the central bottleneck in the acquisition and mining of more data. Large amounts of data are vital for genomics research, and generic compression tools, while viable, cannot offer the same savings as approaches tuned to inherent biological properties. We propose an algorithm to compress a target genome given a known reference genome. The proposed algorithm first generates a mapping from the reference to the target genome, and then compresses this mapping with an entropy coder. As an illustration of the performance: applying our algorithm to James Watson's genome with hg18 as a reference, we are able to reduce the 2991 megabyte (MB) genome down to 6.99 MB, while Gzip compresses it to 834.8 MB.

  11. Compressive Optical Image Encryption (United States)

    Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong


    An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume. PMID:25992946

  12. Deep Blind Compressed Sensing


    Singh, Shikha; Singhal, Vanika; Majumdar, Angshul


    This work addresses the problem of extracting deeply learned features directly from compressive measurements. There has been no work in this area. Existing deep learning tools only give good results when applied on the full signal, that too usually after preprocessing. These techniques require the signal to be reconstructed first. In this work we show that by learning directly from the compressed domain, considerably better results can be obtained. This work extends the recently proposed fram...

  13. Early Mobilization after Free-flap Transfer to the Lower Extremities: Preferential Use of Flow-through Anastomosis

    Directory of Open Access Journals (Sweden)

    Shimpei Miyamoto, MD


    Conclusions: This study demonstrates that early mobilization after free-flap transfer to the lower extremity is made possible by flow-through anastomosis for both arteries and veins. Flow-through flaps have stable circulation from the acute phase and can tolerate early dangling and ambulation.

  14. Colectomy and immediate anastomosis versus on-table colonic lavage for the management of acutely obstructed left colon

    Directory of Open Access Journals (Sweden)

    Mohamed I Kassem


    Conclusions: In favorable situations, omission of on-table lavage may be preferred for immediate anastomosis in obstructed left colonic emergencies. The technique is reliable and well-tolerated with no additional morbidity or mortality. [Arch Clin Exp Surg 2017; 6(3.000: 138-148

  15. Pouchitis-Associated Iritis (Uveitis Following Total Proctocolectomy and Ileal Pouch-to-Anal Anastomosis in Ulcerative Colitis

    Directory of Open Access Journals (Sweden)

    Hugh James Freeman


    Full Text Available A 26-year-old woman with ulcerative colitis treated with a proctocolectomy and ileal pouch-to-anal anastomosis developed an erosive and ulcerative pouchitis. Although no ophthalmological manifestations were present before the staged surgical procedures, iritis developed after appearance of the pouchitis. Both conditions subsequently resolved with oral corticosteroids and metronidazole.

  16. Multiple adjustable vascular clamp prototype: feasibility study on an experimental model of end-to-side microsurgical vascular anastomosis. (United States)

    Pereira, A; Ichihara, S; Collon, S; Bodin, F; Gay, A; Facca, S; Liverneaux, P


    The aim of this study was to establish the feasibility of microsurgical end-to-side vascular anastomosis with a multiclamp adjustable vascular clamp prototype in an inert experimental model. Our method consisted of performing an end-to-side microsurgical anastomosis with 10/0 suture on a 2-mm diameter segment. In group 1, the end-to-side segment was held in place by a double clamp and a single end clamp. In group 2, the segment was held in place with a single multiclamp adjustable clamp. The average time for performing the anastomosis was shorter in group 2. The average number of sutures was the same in both groups. No leak was found and permeability was always positive in both groups. Our results show that performing end-to-side anastomosis with a multiclamp adjustable vascular clamp is feasible in an inert experimental model. Feasibility in a live animal model has to be demonstrated before clinical use. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Sutureless functional end-to-end anastomosis using a linear stapler with polyglycolic acid felt for intestinal anastomoses

    Directory of Open Access Journals (Sweden)

    Masanori Naito, MD, PhD


    Conclusion: Sutureless functional end-to-end anastomosis using the Endo GIA™ Reinforced appears to be safe, efficacious, and straightforward. Reinforcement of the crotch site with a bioabsorbable polyglycolic acid sheet appears to mitigate conventional problems with crotch-site vulnerability.

  18. Pregnancy outcomes and prognostic factors from tubal sterilization reversal by sutureless laparoscopical re-anastomosis: a retrospective cohort study

    NARCIS (Netherlands)

    Schepens, Janneke J. B. F. G.; Mol, Ben W. J.; Wiegerinck, Maarten A. H. M.; Houterman, Saskia; Koks, Carolien A. M.


    BACKGROUND: Female sterilization is a widely used contraceptive method but in a small group of women, post-sterilization regret occurs. A dilemma for these women is the choice between surgical re-anastomosis and IVF. We evaluated the factors that affected pregnancy rate after laparoscopic tubal

  19. Novel Anastomotic Device for Distal Coronary Anastomosis: Preclinical Results From Swine Off-Pump Coronary Artery Bypass Model. (United States)

    Itoda, Yoshifumi; Panthee, Nirmal; Tanaka, Tsuruhito; Ando, Takehiro; Sakuma, Ichiro; Ono, Minoru


    We evaluated the safety and feasibility of a new anastomotic device that simplifies coronary distal anastomosis during minimally invasive and robotically assisted coronary artery bypass graft surgery (CABG). Fourteen miniature pigs underwent off-pump CABG using bilateral internal thoracic arteries (ITA), namely, left ITA to left anterior descending artery and right ITA to right coronary artery. The device was used for distal anastomosis in a device group (n = 11), and conventional 7-0 polypropylene suture in a control group (n = 3). Graft flow was measured intraoperatively. One-month, 3-month, and 6-month postoperative angiography evaluations were done. Histopathologic examination of the anastomosis was also done. Baseline and intraoperative characteristics were similar in the two groups. There was no difference of anastomotic time between groups (p = 0.59). Graft flows were also similar (p = 0.55), with good diastolic pattern in both groups. Angiography demonstrated FitzGibbon A patency in all anastomoses of both groups at each evaluation period. Histopathologic examination showed nonspecific inflammatory changes in the device group. The safety and feasibility of this anastomotic device for distal coronary anastomosis were shown in the swine model. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  20. Compressed Sensing in Astronomy (United States)

    Bobin, Jérôme; Starck, Jean-Luc; Ottensamer, Roland


    Recent advances in signal processing have focused on the use of sparse representations in various applications. A new field of interest based on sparsity has recently emerged: compressed sensing. This theory is a new sampling framework that provides an alternative to the well-known Shannon sampling theory. In this paper, we investigate how compressed sensing (CS) can provide new insights into astronomical data compression. We first give a brief overview of the compressed sensing theory which provides very simple coding process with low computational cost, thus favoring its use for real-time applications often found onboard space mission. In practical situations, owing to particular observation strategies (for instance, raster scans) astronomical data are often redundant; in that context, we point out that a CS-based compression scheme is flexible enough to account for particular observational strategies. Indeed, we show also that CS provides a new fantastic way to handle multiple observations of the same field view, allowing us to recover low level details, which is impossible with standard compression methods. This kind of CS data fusion concept could lead to an elegant and effective way to solve the problem ESA is faced with, for the transmission to the earth of the data collected by PACS, one of the instruments onboard the Herschel spacecraft which will launched in late 2008/early 2009. We show that CS enables to recover data with a spatial resolution enhanced up to 30% with similar sensitivity compared to the averaging technique proposed by ESA.

  1. Unidirectional barbed suture versus standard monofilament for urethrovesical anastomosis during robotic assisted laparoscopic radical prostatectomy

    Directory of Open Access Journals (Sweden)

    Marc Manganiello


    Full Text Available PURPOSE: V-LocTM180 (Covidien Healthcare, Mansfield, MA is a new unidirectional barbed suture that may reduce loss of tension during a running closure. We evaluated the use of the barbed suture for urethrovesical anastomosis (UVA during robotic assisted laparoscopic prostatectomy (RALP. Time to completion of UVA, post-operative anastomotic leak rate, and urinary incontinence were compared in patients undergoing UVA with 3-0 unidirectional-barbed suture vs. 3-0 MonocrylTM (Ethicon, Somerville, NJ. MATERIALS AND METHODS: Data were prospectively collected for 70 consecutive patients undergoing RALP for prostate cancer between November 2009 and October 2010. In the first 35 patients, the UVA was performed using a modified running van Velthoven anastomosis technique using two separate 3-0 monofilament sutures. In the subsequent 35 patients, the UVA was performed using two running novel unidirectional barbed sutures. At 7-12 days postoperatively, all patients were evaluated with a cystogram to determine anastomotic integrity. Urinary incontinence was assessed at two months and five months by total daily pad usage. Clinical symptoms suggestive of bladder neck contracture were elicited. RESULTS: Age, PSA, Gleason score, prostate size, estimated blood loss, body mass index, and clinical and pathologic stage between the 2 groups were similar. Comparing the monofilament group and V-LocTM180 cohorts, average time to complete the anastomosis was similar (27.4 vs. 26.4 minutes, p = 0.73 as was the rate of urinary extravasation on cystogram (5.7 % vs. 8.6%, p = 0.65. There were no symptomatic bladder neck contractures noted at 5 months of follow-up. At 2 months, the percentage of patients using 2 or more pads per day was lower in the V-LocTM180 cohort (24% vs. 44%, p < 0.02. At 5 months, this difference was no longer evident. CONCLUSIONS: Time to complete the UVA was similar in the intervention and control groups. Rates of urine leak were also comparable

  2. Full robot-assisted gastrectomy with intracorporeal robot-sewn anastomosis produces satisfying outcomes (United States)

    Liu, Xin-Xin; Jiang, Zhi-Wei; Chen, Ping; Zhao, Yan; Pan, Hua-Feng; Li, Jie-Shou


    AIM: To evaluate the feasibility and safety of full robot-assisted gastrectomy with intracorporeal robot hand-sewn anastomosis in the treatment of gastric cancer. METHODS: From September 2011 to March 2013, 110 consecutive patients with gastric cancer at the authors’ institution were enrolled for robotic gastrectomies. According to tumor location, total gastrectomy, distal or proximal subtotal gastrectomy with D2 lymphadenectomy was fully performed by the da Vinci Robotic Surgical System. All construction, including Roux-en-Y jejunal limb, esophagojejunal, gastroduodenal and gastrojejunal anastomoses were fully carried out by the intracorporeal robot-sewn method. At the end of surgery, the specimen was removed through a 3-4 cm incision at the umbilicus trocar point. The details of the surgical technique are well illustrated. The benefits in terms of surgical and oncologic outcomes are well documented, as well as the failure rate and postoperative complications. RESULTS: From a total of 110 enrolled patients, radical gastrectomy could not be performed in 2 patients due to late stage disease; 1 patient was converted to laparotomy because of uncontrollable hemorrhage, and 1 obese patient was converted due to difficult exposure; 2 patients underwent extra-corporeal anastomosis by minilaparotomy to ensure adequate tumor margin. Robot-sewn anastomoses were successfully performed for 12 proximal, 38 distal and 54 total gastrectomies. The average surgical time was 272.52 ± 53.91 min and the average amount of bleeding was 80.78 ± 32.37 mL. The average number of harvested lymph nodes was 23.1 ± 5.3. All specimens showed adequate surgical margin. With regard to tumor staging, 26, 32 and 46 patients were staged as I, II and III, respectively. The average hospitalization time after surgery was 6.2 d. One patient experienced a duodenal stump anastomotic leak, which was mild and treated conservatively. One patient was readmitted for intra-abdominal infection and was

  3. Deformation characteristics and sealing performance of metallic-O-ring for a reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Ming Xue; Peng, Xudong; Xie, Linjun; Meng, Xiang Kai [Engineering Research Center of Process Equipment and Its Remanufacture, Ministry of Education, Zhejiang University of Technology, Hangzhou (China); Li, Xing Gen [Ningbo Tiansheng Sealing Packing Co., Ltd., Ningbo (China)


    This paper provides a reference to determine the seal performance of metallic O-rings for a reactor pressure vessel (RPV). A nonlinear elastic-plastic model of an O-ring was constructed by the finite element method to analyze its intrinsic properties. It is also validated by experiments on scaled samples. The effects of the compression ratio, the geometrical parameters of the O-ring, and the structure parameters of the groove on the flange are discussed in detail. The results showed that the numerical analysis of the O-ring agrees well with the experimental data, the compression ratio has an important role in the distribution and magnitude of contact stress, and a suitable gap between the sidewall and groove can improve the sealing capability of the O-ring. After the optimization of the sealing structure, some key parameters of the O-ring (i.e., compression ratio, cross-section diameter, wall thickness, sidewall gap) have been recommended for application in megakilowatt class nuclear power plants. Furthermore, air tightness and thermal cycling tests were performed to verify the rationality of the finite element method and to reliably evaluate the sealing performance of a RPV.

  4. Deformation Characteristics and Sealing Performance of Metallic O-rings for a Reactor Pressure Vessel

    Directory of Open Access Journals (Sweden)

    Mingxue Shen


    Full Text Available This paper provides a reference to determine the seal performance of metallic O-rings for a reactor pressure vessel (RPV. A nonlinear elastic-plastic model of an O-ring was constructed by the finite element method to analyze its intrinsic properties. It is also validated by experiments on scaled samples. The effects of the compression ratio, the geometrical parameters of the O-ring, and the structure parameters of the groove on the flange are discussed in detail. The results showed that the numerical analysis of the O-ring agrees well with the experimental data, the compression ratio has an important role in the distribution and magnitude of contact stress, and a suitable gap between the sidewall and groove can improve the sealing capability of the O-ring. After the optimization of the sealing structure, some key parameters of the O-ring (i.e., compression ratio, cross-section diameter, wall thickness, sidewall gap have been recommended for application in megakilowatt class nuclear power plants. Furthermore, air tightness and thermal cycling tests were performed to verify the rationality of the finite element method and to reliably evaluate the sealing performance of a RPV.

  5. A New Supermicrosurgery Training Model of Saphenous Artery and Great Saphenous Vein Anastomosis for Development of Advanced Microsurgical Skills. (United States)

    Bas, Can Emre; Cwykiel, Joanna; Siemionow, Maria


    Background This study aimed to confirm the feasibility and reliability of saphenous artery (SA) and great saphenous vein (GSV) anastomosis as a new supermicrosurgery training model and to compare the one-way-up anastomosis with the currently used end-to-end anastomosis technique. Methods Twenty supermicrosurgical anastomoses were performed in 10 Sprague Dawley rats. The external diameters of SA and GSV were measured using Leica LAS EZ software. The right-side SA and GSV anastomoses were performed using the standard end-to-end anastomosis technique. The left-side SA and GSV anastomoses were performed using the one-way-up technique with 11-0 monofilament-interrupted sutures. The duration of the surgery, patency rates, and technical challenges of the two anastomoses methods were compared. Results The mean external diameters of SA and GSV were 0.273 ± 0.03 and 0.291 ± 0.02 mm, respectively, which qualify these vessels for supermicrosurgical training. The vessels were easily accessible and both anastomosis techniques were feasible. The one-way-up technique was proven to be faster as compared with the end-to-end anastomosis technique (artery: 34 ± 2.55 vs. 40.4 ± 2.97 minutes, p = 0.02; and vein: 37 ± 4.85 vs. 44 ± 2.35 minutes, p = 0.05, respectively). Short-term patency rates for arteries and veins were 100% for both techniques. Seven-day anastomosis patency rates for arteries and veins were 80 and 100% for the end-to-end technique and 100 and 80% for the one-way-up technique, respectively. Conclusions We confirmed that saphenous pedicle is suitable for creating a supermicrosurgery training model for practicing the ultrafine motor skills. To the best of our knowledge, this is the first report on supermicrosurgery of SA and GSV in the rat model. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  6. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana


    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  7. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina


    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction and a realis......We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  8. Instrumento quirúrgico de sutura para anastomosis automática del tubo digestivo


    Tornero García, José Antonio; Suárez Feijóo, Raúl; Cano Casas, Francesc; Montaño Sarria, Andrés Felipe; López Cano, Manuel


    En la cirugía digestiva, una anastomosis del intestino consiste en la reconstrucción del tubo digestivo por unión de dos cabos tras la resección de una porción del mismo. Este procedimiento, de común aplicación en diversos tipos de intervención quirúrgica se realiza actualmente mediante la aplicación de grapas metálicas debido a la complejidad inherente de la realización de una sutura manual. La automatización del proceso de sutura mediante un dispositivo diseñado a tal efecto supondría una n...

  9. Late results of mucosal proctectomy and colo-anal sleeve anastomosis for chronic irradiation rectal injury

    Energy Technology Data Exchange (ETDEWEB)

    Browning, G.G.P.; Varma, J.S.; Smith, A.N.; Small, W.P.; Duncan, W.


    Ten patients with severe chronic irradiation injury to the rectum were treated by mucosal proctectomy and colo-anal sleeve anastomosis. The indications were: recurrent rectal bleeding (five), stricture (three), fistula (one) and intractable pain (one). Overall follow-up has ranged from 8 to 77 months (mean 40 months). In the present survivors (n=7) the follow-up ranges from 18 to 77 months (mean 52 months). Six patients have been followed up for more than 3 years and four for more than 5 years. There was no operative mortality. Three anastomotic strictures occurred but the protecting stoma could be closed in all but one patient. Continence was acceptable although urgency and frequency of defaecation were troublesome symptoms. The operation is recommended for life-threatening, haemorrhagic chronic irradiation injury to the rectum.

  10. Robotic Assisted Laparoscopic Prostatectomy in Men with Proctocolectomy and Restorative Ileal Pouch-Anal Anastomosis

    Directory of Open Access Journals (Sweden)

    Michael Leapman


    Full Text Available We conducted a retrospective chart review of robotic prostatectomies done by a single surgeon between 2003 and 2012. During that time period, we identified two patients within the year 2012, with ileal pouch-anal anastomosis (IPPA who also underwent robotic prostatectomies. The demographics and postoperative characteristics of the two patients were assessed. In both patients, prostatectomy, bilateral nerve sparing, and pelvic lymphadenectomy were successfully performed and the integrity of ileal pouch was maintained. There was a mean surgical time of 144.5 minutes, and an average estimated blood loss was 125 mL. Both patients were discharged on the second day postoperatively. In both patients there was a Gleason upgrade to 3 + 4, with negative margins, and preservation of fecal and urinary continence by their six-month followup. Owing to surgical modifications, these two surgeries represent the first successful robotic prostatectomies in patients with a J-pouch.

  11. Robotic assisted laparoscopic prostatectomy in men with proctocolectomy and restorative ileal pouch-anal anastomosis. (United States)

    Leapman, Michael; Kwon, Young Suk; Collingwood, Shemille A; Chin, Edward; Katsigeorgis, Maria; Hobbs, Adele R; Samadi, David B


    We conducted a retrospective chart review of robotic prostatectomies done by a single surgeon between 2003 and 2012. During that time period, we identified two patients within the year 2012, with ileal pouch-anal anastomosis (IPPA) who also underwent robotic prostatectomies. The demographics and postoperative characteristics of the two patients were assessed. In both patients, prostatectomy, bilateral nerve sparing, and pelvic lymphadenectomy were successfully performed and the integrity of ileal pouch was maintained. There was a mean surgical time of 144.5 minutes, and an average estimated blood loss was 125 mL. Both patients were discharged on the second day postoperatively. In both patients there was a Gleason upgrade to 3 + 4, with negative margins, and preservation of fecal and urinary continence by their six-month followup. Owing to surgical modifications, these two surgeries represent the first successful robotic prostatectomies in patients with a J-pouch.

  12. Peri-orbital lymphangioma treated by lymphatic-venous anastomosis with indocyanine green lymphography analysis

    Directory of Open Access Journals (Sweden)

    Motoi Kato, M.D.


    There has been a question of the exact location and direction of lymphatic flow into, within, and out of LM. There were some reports investigating the intra-cystic flow of LM; however, only a few focused on the afferent and efferent lymphatic flow of LM. With our detailed study using lymphography, we were able to determine the lymphatic flow pattern in periorbital LM, which was large enough to perform lymphatic venous anastomosis (LVA. LVA is a surgically-placed bypass between afferent collecting lymphatic vessels and veins, which in our study resulted in decreasing both the influx and the total volume of lymph in the LM. To our knowledge, this is the first study of Indocyanine green (ICG lymphography on mLM, and LVA for its treatment. Here we present our case of periorbital mLM with LVA and discuss its less invasive surgical strategy.

  13. Venous anastomosis procedure for treatment of lymphatic malformation in Klippel-Trenaunay syndrome

    Directory of Open Access Journals (Sweden)

    Motoi Kato, M.D.


    We previously reported that lymphatic venous anastomosis (LVA may be a safe and effective procedure for reducing the size of micro cystic type LM by decreasing the intra cystic lymph [3]. We treated a case of KTS in a 9-year-old boy who had improvement of lower abdominal swelling and penile pain after a single LVA. The method involved is to make a bypass, from the afferent lymph-collecting vessel to subcutaneous veins. However, to apply LVA to LM, it is sometimes problematic to detect the afferent flow in combined vascular malformations, such as KTS. Therefore, we performed VA making a bypass directly from LM, instead. We classify two types of LVA methods for LM: afferent lymph vessel LMVA (A-LMVA, and sidewall LMVA (S-LMVA. S-LMVA has more merits than the previously reported A-LMVA.

  14. A сase of obstruction of SVC-right atrium appendage anastomosis after procedure Warden

    Directory of Open Access Journals (Sweden)

    Е. А. Связов


    Full Text Available The analysis of a 6-year patient’s medical history after correction of congenital heart disease (partial anomalous drainage of the right superior pulmonary vein into the superior vena cava complicated by obstruction of the anastomosis between the SVC and the appendage right atrium is presented. The article discusses the stages of diagnosis and patient management features, as well as the choice of treatment.Received 12 December 2016. Accepted 14 February 2017.Financing: The study did not have sponsorship.Conflict of interest: The authors declare no conflict of interest.Svyazov E.A.: data analysis, article writing and editing. Podoksenov A.U.: article editing. Varvarenko V.I.: implantation of the stent-graft in superior vena cava.Martsinkevich G.I.: echocardiographic examination of the patient before and after endograft implantation, article editing. Krivoshchyokov E.V.: organizational work and referral of the patient to endovascular treatment, article editing.

  15. Ring Image Analyzer (United States)

    Strekalov, Dmitry V.


    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  16. Improved Functional Results After Minimally Invasive Esophagectomy: Intrathoracic Versus Cervical Anastomosis. (United States)

    van Workum, Frans; van der Maas, Jolijn; van den Wildenberg, Frits J H; Polat, Fatih; Kouwenhoven, Ewout A; van Det, Marc J; Nieuwenhuijzen, Grard A P; Luyer, Misha D; Rosman, Camiel


    Both cervical esophagogastric anastomosis (CEA) and intrathoracic esophagogastric anastomosis (IEA) are used to restore gastrointestinal integrity following minimally invasive esophagectomy (MIE). No prospective randomized data on functional outcome, postoperative morbidity, and mortality between these techniques are currently available. A comparison was conducted including all consecutive patients with esophageal carcinoma of the distal esophagus or gastroesophageal junction undergoing MIE with CEA or MIE with IEA from October 2009 to July 2014 in 3 high-volume esophageal cancer centers. Functional outcome, postoperative morbidity, and mortality were analyzed. MIE with CEA was performed in 146 patients and MIE with IEA in 210 patients. The incidence of recurrent laryngeal nerve palsy was 14.4% after CEA and 0% after IEA (p < 0.001). Dysphagia, dumping, and regurgitation were reported less frequently after IEA compared with CEA (p < 0.05). Dilatation of benign strictures occurred in 43.8% after CEA and this was 6.2% after IEA (p < 0.001). If a benign stricture was identified, it was dilated a median of 4 times in the CEA group and only once in the IEA group (p < 0.001). Anastomotic leakage for which reoperation was required occurred in 8.2% after CEA and in 11.4% after IEA (not significant). Median ICU stay, hospital stay, in-hospital mortality, 30-day mortality, and 90-day mortality were similar between the groups (not significant). MIE with IEA was associated with better functional results than MIE with CEA with less dysphagia, less benign anastomotic strictures requiring fewer dilatations, and a lower incidence of recurrent laryngeal nerve palsy. Other postoperative morbidity and mortality did not differ between the groups. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Safety and Efficacy of Alginate Adhesion Barrier Gel in Compromised Intestinal Anastomosis. (United States)

    Chaturvedi, Ankit A; Yauw, Simon T K; Lomme, Roger M L M; Hendriks, Thijs; van Goor, Harry

    For any anti-adhesive barrier developed for abdominal surgery, the use under conditions in which anastomotic healing is compromised needs to be investigated. The current study evaluates the effect of a new ultrapure alginate gel on early healing of high-risk anastomoses in the ileum and compares this with the gold standard used in clinical practice. In 75 adult male Wistar rats, a 5 mm ileal segment was resected and continuity was restored by construction of an inverted anastomosis. Rats were divided randomly into a control group and groups receiving either alginate gel or a sodium hyaluronate carboxymethylcellulose (HA/CMC) film around the anastomosis (n = 25 each). Carprofen, given in a daily dose of 1.25 mg/kg, was used to compromise anastomotic healing. At day three, animals were killed and scored for signs of anastomotic leakage and the presence of adhesions. The incidence of adhesion formation was 95% in the HA/CMC film group, which was significantly higher than in the controls (64%, p = 0.010) and the alginate gel group (52%, p = 0.004). The adhesion score was nearly 40% lower in the alginate gel group compared with the HA/CMC film group. The incidence of ileal leakage in the HA/CMC film group (92%) was significantly higher than in the controls (68%, p = 0.016). Leakage rate did not differ between the alginate gel and control groups. There was no significant difference between groups in either incision bursting pressure or incision breaking strength. Ultrapure alginate gel does not interfere with repair of ileal anastomoses constructed under conditions in which chances of anastomotic dehiscence are high. The alginate gel performs better than the HA/CMC film.

  18. Intraoral microvascular anastomosis for segmental mandibular reconstruction following removal of an ameloblastoma. (United States)

    Nkenke, Emeka; Agaimy, Abbas; St Pierre, Michael; Gratzki, Nils; Stockmann, Philipp; von Wilmowsky, Cornelius


    Cases of immediate bony microvascular reconstruction following segmental mandibulectomy in children are hard to find in the current literature. Moreover, microvascular segmental mandibular reconstruction that adopts an intraoral anastomosis technique has not been described so far. Therefore, the present clinical report aims at extending the armamentarium of bony microvascular reconstruction in pediatric cases of segmental mandibulectomy by highlighting an intraoral microvascular anastomosing technique.A 6-year-old boy, who suffered from an ameloblastoma of the mural type in the mandible, received a radical segmental mandibular resection because of the high recurrence rate of this tumor entity. Immediate reconstruction was carried out with a fibular double-barrel graft. Microvascular anastomoses were performed in an end-to-end fashion with the facial artery and vein as recipient vessels. The postoperative course was uneventful. There was no impairment of speech, deglutition, mastication, and facial nerve function. The facial appearance remained unobtrusive. On removal of the reconstruction plate 3 months after the reconstruction procedure, bleeding from the reconstructed mandibular segment indicated vascularization of the graft.It seems that segmental mandibulectomy and simultaneous microvascular bony reconstruction do not necessarily lead to impaired function as far as speech, deglutition, and mastication are concerned. Instead, the intraoral anastomosis technique allows waiving extraoral skin incisions and subsequent scarring, leaving the facial appearance unchanged and unobtrusive. Especially, the potential risk of stigmatization of the patient is avoided. Therefore, decision making in the choice of 1 or the other reconstruction option following segmental mandibulectomy should always consider the adoption of an intraoral anastomosing technique.

  19. Vascular anatomy in children with univentricular hearts regarding transcatheter bidirectional Glenn anastomosis. (United States)

    Sizarov, Aleksander; Raimondi, Francesca; Bonnet, Damien; Boudjemline, Younes


    Transcatheter stent-secured Glenn anastomosis, aiming to reduce the invasiveness of palliation in patients with univentricular heart defects, has been reported in large experimental animals. The advent of biodegradable stents and tissue-engineered vascular grafts will make this procedure a reality in human patients. However, the relationship between the superior vena cava (SVC) and the right pulmonary artery (RPA) is different in humans. To characterise vascular anatomy in children with univentricular hearts, regarding technical aspects and device design for this procedure. Retrospective analysis of 35 thoracic computed tomography angiograms at a mean age of 18.1±22.4 months. Two types of arrangement between the SVC and the RPA were identified: anatomy convenient for immediate wire passage and stent deployment between the two vessels (60%); and pattern of early RPA branching, requiring the perforation wire to traverse the intervascular space to avoid entrance into the upper RPA branch (40%). In patients with the convenient vascular arrangement, the vessels were nearly perpendicular, having immediate contact, with the posterior SVC aspect partially "wrapping" the adjacent RPA in most patients. In patients with early RPA branching, the mean shortest SVC-to-central RPA distance was 4.3±2.7mm. For the total population, the mean length of proximal SVC that allowed stent deployment without covering the brachiocephalic vein was 15.6±5.1mm. A trumpet-shaped covered stent in a craniocaudal orientation reaching from the SVC into the prebranching RPA seems most suitable for achieving bidirectional Glenn anastomosis percutaneously in humans. However, the short length of the proximal SVC and the presence of early RPA branching pose challenges for optimal design of the dedicated device. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. Side-to-end hypoglossal to facial anastomosis with transposition of the intratemporal facial nerve. (United States)

    Slattery, William H; Cassis, Adam M; Wilkinson, Eric P; Santos, Felipe; Berliner, Karen


    To describe results in a large series of patients using a recent variation of hypoglossal-facial nerve anastomosis (HFA) in which the intratemporal facial nerve segment is used, obviating the need for a sensory nerve "jump graft." Retrospective chart review. Tertiary neurotologic referral center. Nineteen patients (12 female/7 male subjects) with facial paralysis because of posterior fossa surgery for tumor (n = 15), Bell's palsy (n = 1), facial neuroma (n = 1), hemangioma (n = 1), and trauma (n = 1) who underwent HFA from 1997 to 2011, with at least 1-year follow-up. Mean age at surgery is 47.4 years (range, 11.2-83 yr). Mean follow-up is 4.0 years. Side-to-end hypoglossal to facial anastomosis with transposition of the intratemporal facial nerve (swingdown HFA). House-Brackmann (H-B) facial nerve grade. Seven patients (36.8%) achieved an H-B Grade III, 9 patients (47.4%) a grade IV, and 3 patients (15.8%) a grade V at last follow-up. No patients complained of dysphagia, dysarthria, or had evidence of oral incompetence. One patient complained of mild tongue weakness. Age at time of HFA (p ≤ 0.049, III younger than V) and time from facial nerve injury to HFA (p ≤ 0.02, IIIfacial nerve outcome. All patients with an H-B III result had HFA within 6 months of injury. Other factors were not significant. The HFA swingdown technique is a safe and effective method to restore facial nerve function in patients with facial paralysis and obviates the need for an interposition jump graft.

  1. Use of bioabsorbable staple reinforcement material in side-to-side anastomoses: Suture line reinforcement of the weak point of the anastomosis. (United States)

    Kimura, Masahiro; Terashita, Yukio


    Few studies have been designed regarding optimal reinforcement of the crotch of a side-to-side anastomosis. The purpose of this study was to clarify the weak point of the side-to-side anastomosis and to evaluate the effect of bioabsorbable reinforcement material. Fresh pig small bowel was used for all experiments. A side-to-side anastomosis was performed using a linear stapler, and the burst pressure of the anastomosis was measured. Three separate experiments were done. In experiment 1, the weak point and the burst pressure of that point were defined. In experiment 2, the burst pressure of the side of the anastomosis was measured. In experiment 3, we evaluated the effect of Neoveil(®) to strengthen the weak point of the anastomosis. The weak point of the side-to side anastomosis was the crotch and the burst pressure was 39.8 ± 5.7 mmHg. The burst pressure of the side of the anastomosis was 109.9 ± 7.9 mmHg. This was significantly higher than the burst pressure of the crotch (P = 0.008). The burst pressure of the crotch in the group with Neoveil(®) was 83.3 ± 14.9 mmHg. This pressure was significantly higher than the group with no Neoveil(®) reinforcement (P = 0.001). These findings suggest that the use of Neoveil(®) as a buttressing material is associated with reinforced staple lines and increased crotch burst pressures compared to non-buttressed staple lines. Neoveil(®) was found to perform comparably to clinically available buttress materials in this ex vivo model. Reinforcement of the weak point of the side-to-side anastomosis with Neoveil(®)may lead to fewer anastomotic leaks.

  2. Deformation Characteristics and Sealing Performance of Metallic O-rings for a Reactor Pressure Vessel


    Shen, Mingxue; PENG, Xudong; Xie, Linjun; Meng, Xiangkai; Li, Xinggen


    This paper provides a reference to determine the seal performance of metallic O-rings for a reactor pressure vessel (RPV). A nonlinear elastic-plastic model of an O-ring was constructed by the finite element method to analyze its intrinsic properties. It is also validated by experiments on scaled samples. The effects of the compression ratio, the geometrical parameters of the O-ring, and the structure parameters of the groove on the flange are discussed in detail. The results showed that the ...

  3. Useful signs for the assessment of vascular rings on cross-sectional imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gould, Sharon W. [Nemours/Alfred I. duPont Hospital for Children, Medical Imaging, P.O. Box 269, Wilmington, DE (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital, Medical Imaging, Chicago, IL (United States); Donnelly, Lane F. [Texas Children' s Hospital, Pediatric Radiology, Houston, TX (United States); McCulloch, Michael [Nemours/Alfred I. duPont Hospital for Children, Pediatric Cardiology, P.O. Box 269, Wilmington, DE (United States); Pizarro, Christian [Nemours/Alfred I. duPont Hospital for Children, Pediatric Cardiac Surgery, P.O. Box 269, Wilmington, DE (United States); Epelman, Monica [Nemours Children' s Hospital, Medical Imaging, Orlando, FL (United States)


    Vascular rings can be challenging to diagnose because they can contain atretic portions not detectable with current imaging modalities. In these cases, where the compressed airway and esophagus are not encircled by patent, opacified vessels, there are useful secondary signs that should be considered and should raise suspicion for the presence of a vascular ring. These signs include a double aortic arch, the four-vessel sign, the distorted subclavian artery sign, a diverticulum of Kommerell, a ductal diverticulum contralateral to the aortic arch, and a descending aorta contralateral to the arch or circumflex aorta. If none of these findings is present, a ring can be excluded with confidence. (orig.)

  4. Ring current and radiation belts (United States)

    Williams, D. J.


    Studies performed during 1983-1986 on the ring current, the injection boundary model, and the radiation belts are discussed. The results of these studies yielded the first observations on the composition and charge state of the ring current throughout the ring-current energy range, and strong observational support for an injection-boundary model accounting for the origins of radiation-belt particles, the ring current, and substorm particles observed at R less than about 7 earth radii. In addition, the results have demonstrated that the detection of energetic neutral atoms generated by charge-exchange interactions between the ring current and the hydrogen geocorona can provide global images of the earth's ring current and its spatial and temporal evolution.

  5. Filtration on a Ring Make a Quasi Valuation or Valuation Ring

    Directory of Open Access Journals (Sweden)

    Mohammad Hassan Anjom SHoa


    Full Text Available In this paper we show that if R is a filtered ring then we can define a quasi valuation ring. And there exists a valuation ring if R is some kind of filtered ring. Then we prove some properties and relations between filtered ring and quasi valuation ring and valuation ring.

  6. Saturn's Rings and Associated Ring Plasma Cavity: Evidence for Slow Ring Erosion (United States)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.


    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C- ring, leading to field-aligned plasma transport to Saturns ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma fountains. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >10(exp 9) years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  7. Saturn's rings and associated ring plasma cavity: Evidence for slow ring erosion (United States)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.


    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C-ring, leading to field-aligned plasma transport to Saturn's ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma 'fountains'. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >109 years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  8. [Gastric adenocarcinoma following "silastic vertical ring gastroplasty": case report]. (United States)

    Belhaj, A; Memmo, L; Memo, L; Mehdi, A; Mboti, F; Closset, J


    Bariatric surgery is considered as the most effective therapy for morbid obesity. But, each procedure carries both short-and long-term complications. And, it remains unclear if the late occurrence of gastric adenocarcinoma could be linked to bariatric surgery. We described a case of a female who developed a gastric adenocarcinoma after a silastic ring vertical gastroplasty (SRVG). A 54-year-old female presented with postprandial vomiting, poor appetite, dysphagia and weight loss 10 year after a SRVG. A gastroscopy with biopsy disclosed a juxta-pyloric adenocarcinoma. No distant metastasis was found. After 3 cycles of neoadjuvant chemotherapy, a subtotal gastrectomy with Roux-en-Y anastomosis was performed. After the surgery, a minor anastomotic leak was treated conservatively and a parietal abscess was drained. The pathological studies demonstrated a T2bN1 adenocarcinoma with negative margins. Adjuvant chemotherapy was administered. At the last work up, the patient is disease-free. The association between a gastric adenocarcinoma and a bariatric procedure such as a SRVG is difficult to assess without a case-control or a cross-sectional study. Nevertheless, when new upper digestive tract complaints occur in any patient with an otherwise unremarkable bariatric surgery follow-up, the diagnosis of gastric cancer should be bear in mind.

  9. Ground Movement in SSRL Ring

    Energy Technology Data Exchange (ETDEWEB)

    Sunikumar, Nikita; /UCLA /SLAC


    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  10. n-X-Coherent Rings


    Bennis, Driss


    This paper unifies several generalizations of coherent rings in one notion. Namely, we introduce $n$-$\\mathscr{X}$-coherent rings, where $\\mathscr{X}$ is a class of modules and $n$ is a positive integer, as those rings for which the subclass $\\mathscr{X}_n$ of $n$-presented modules of $\\mathscr{X}$ is not empty, and every module in $\\mathscr{X}_n$ is $n+1$-presented. Then, for each particular class $\\mathscr{X}$ of modules, we find correspondent relative coherent rings. Our main aim is to sho...

  11. Integrated Ring Resonators The Compendium

    CERN Document Server

    Rabus, Dominik G


    The optical filter, which has emerged in the last few years in integrated optics, is resonator based. Ring-resonator filters do not require facets or gratings for optical feedback and are thus particularly suited for monolithic integration with other components. Ring resonators find applications not only in optical networks, but also as sensors. The required passband shape of ring resonator-filters can be custom designed by the use of configurations of various ring coupled resonators. This book describes the current state-of-the-art on these devices with respect to design, fabrication and application.

  12. Studies Performed in Preparation for the Spallation Neutron Source Accumulator Ring Commissioning

    CERN Document Server

    Cousineau, Sarah M; Henderson, Stuart; Holmes, Jeffrey Alan; Plum, Michael


    The Spallation Neutron Source accumulator ring will compress 1.5?1014, 1 GeV protons from a 1 ms bunch train to a single 695 ns proton bunch for use in neutron spallation. Due to the high beam power, unprecedented control of beam loss will be required in order to control radiation and allow for hands-on maintenance in most areas of the ring. A number of detailed investigations have been performed to understand the primary sources of beam loss and to predict and mitigate problems associated with radiation hot spots in the ring. The ORBIT particle tracking code is used to perform realistic simulations of the beam accumulation in the ring, including detailed modeling of the injection system, transport through the measured magnet fields including higher order multipoles, and beam loss and collimation. In this paper we present the results of a number of studies performed in preparation for the 2006 commissioning of the accumulator ring.

  13. Distances in generalized Double Rings and Degree Three Chordal Rings

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun


    Generalized Double Rings (N2R) are compared to Degree Three Chordal Rings (CR) in terms of average distance, diameter, k-average distance and k-diameter. For each number of nodes, structures of each class are chosen to minimize diameter and average distance, an approach which is shown to result...

  14. Distances in Generalized Double Rings and Degree Three Chordal Rings

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun


    Generalized Double Rings (N2R) are compared to Degree Three Chordal Rings (CR) in terms of average distance, diameter, k-average distance and k-diameter. For each number of nodes, structures of each class are chosen to minimize diameter and average distance, an approach which is shown to result...

  15. RING E3 ligases

    DEFF Research Database (Denmark)

    Cho, Seok Keun; Ryu, Moon Young; Kim, Jong Hum


    Plants are constantly exposed to a variety of abiotic stresses, such as drought, heat, cold, flood, and salinity. To survive under such unfavorable conditions, plants have evolutionarily developed their own resistant-mechanisms. For several decades, many studies have clarified specific stress...... response pathways of plants through various molecular and genetic studies. In particular, it was recently discovered that ubiquitin proteasome system (UPS), a regulatory mechanism for protein turn over, is greatly involved in the stress responsive pathways. In the UPS, many E3 ligases play key roles...... in recognizing and tethering poly-ubiquitins on target proteins for subsequent degradation by the 26S proteasome. Here we discuss the roles of RING ligases that have been defined in related to abiotic stress responses in plants....

  16. The eRHIC Ring-Ring Collider Design

    CERN Document Server

    Wang, Fuhua; Beebe-Wang, Joanne; Deshpande, Abhay A; Farkhondeh, Manouchehr; Franklin, Wilbur; Graves, William; Litvinenko, Vladimir N; MacKay, William W; Milner, Richard; Montag, Christoph; Ozaki, Satoshi; Parker, Brett; Peggs, Steve; Ptitsyn, Vadim; Roser, Thomas; Tepikian, Steven; Trbojevic, Dejan; Tschalär, C; Wang, Dong; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan


    The eRHIC ring-ring collider is the main design option of the future lepton-ion collider at Brookhaven National Laboratory. We report the revisions of the ring-ring collider design features to the baseline design presented in the eRHIC Zeroth Design Report (ZDR). These revisions have been made during the past year. They include changes of the interaction region which are required from the modifications in the design of the main detector. They also include changes in the lepton storage ring for high current operations as a result of better understandings of beam-beam interaction effects. The updated collider luminosity and beam parameters also take into account a more accurate picture of current and future operational aspects of RHIC.

  17. Graph Compression by BFS

    Directory of Open Access Journals (Sweden)

    Alberto Apostolico


    Full Text Available The Web Graph is a large-scale graph that does not fit in main memory, so that lossless compression methods have been proposed for it. This paper introduces a compression scheme that combines efficient storage with fast retrieval for the information in a node. The scheme exploits the properties of the Web Graph without assuming an ordering of the URLs, so that it may be applied to more general graphs. Tests on some datasets of use achieve space savings of about 10% over existing methods.

  18. Anisotropic Concrete Compressive Strength

    DEFF Research Database (Denmark)

    Gustenhoff Hansen, Søren; Jørgensen, Henrik Brøner; Hoang, Linh Cao


    When the load carrying capacity of existing concrete structures is (re-)assessed it is often based on compressive strength of cores drilled out from the structure. Existing studies show that the core compressive strength is anisotropic; i.e. it depends on whether the cores are drilled parallel...... correlation to the curing time. The experiments show no correlation between the anisotropy and the curing time and a small strength difference between the two drilling directions. The literature shows variations on which drilling direction that is strongest. Based on a Monto Carlo simulation of the expected...

  19. Rheology modification with ring polymers (United States)

    Vlassopoulos, Dimitris

    It is now established that experimental unconcatenated ring polymers can be purified effectively by means of fractionation at the critical condition. For molecular weights well above the entanglement threshold, purified rings relax stress via power-law (with an exponent of about -0.4), sharply departing from their linear counterparts. Experimental results are in harmony with modeling predictions and simulations. Here, we present results from recent interdisciplinary efforts and discuss two challenges: (i) the nonlinear shear rheology of purified ring melts is also very different from that of unlinked chains. Whereas the latter exhibit features that can be explained, to a first approach, in the framework in the tube model, the former behave akin to unentangled chains with finite extensibility and exhibit much small deformation at steady state. (ii) blends of rings and linear polymers exhibit unique features in different regimes: The addition of minute amounts of linear chains drastically affects ring dynamics. This relates to ring purity and the ability of unlinked linear chains to thread rings. With the help of simulations, it is possible to rationalize the observed surprisingly slow viscoelastic relaxation, which is attributed to ring-linear and ring-ring penetrations. On the other hand, adding small amounts of rings to linear polymers of different molecular weights influences their linear and nonlinear rheology in an unprecedented way. The blend viscosity exceeds that of the slower component (linear) in this non-interacting mixture, and its dependencies on composition and molecular weight ratio are examined, whereas the role of molecular architecture is also addressed. Consequently, closing the ends of a linear chain can serve as a powerful means for molecular manipulation of its rheology. This presentation reflects collaborative efforts with S. Costanzo, Z-C. Yan, R. Pasquino, M. Kaliva, S. Kamble, Y. Jeong, P. Lutz, J. Allgaier, T. Chang, D. Talikis, V

  20. Clean elements in abelian rings

    Indian Academy of Sciences (India)

    Let be a ring with identity. An element in is said to be clean if it is the sum of a unit and an idempotent. is said to be clean if all of its elements are clean. If every idempotent in is central, then is said to be abelian. In this paper we obtain some conditions equivalent to being clean in an abelian ring.

  1. Code–checkable group rings

    Directory of Open Access Journals (Sweden)

    Noha Abdelghany


    Full Text Available A code over a group ring is defined to be a submodule of that group ring. For a code $C$ over a group ring $RG$, $C$ is said to be checkable if there is $v\\in RG$ such that {$C=\\{x\\in RG: xv=0\\}$}. In \\cite{r2}, Jitman et al. introduced the notion of code-checkable group ring. We say that a group ring $RG$ is code-checkable if every ideal in $RG$ is a checkable code. In their paper, Jitman et al. gave a necessary and sufficient condition for the group ring $\\mathbb{F}G$, when $\\mathbb{F}$ is a finite field and $G$ is a finite abelian group, to be code-checkable. In this paper, we give some characterizations for code-checkable group rings for more general alphabet. For instance, a finite commutative group ring $RG$, with $R$ is semisimple, is code-checkable if and only if $G$ is $\\pi'$-by-cyclic $\\pi$; where $\\pi$ is the set of noninvertible primes in $R$. Also, under suitable conditions, $RG$ turns out to be code-checkable if and only if it is pseudo-morphic.

  2. Richard Schatzki: a familiar ring. (United States)

    Patel, Birju; Han, Eugene; Swan, Kenneth


    The Schatzki ring was named for Richard Schatzki, a renowned radiologist who described the entity with his colleague, John E. Gary. The purpose of this article is to shed more light on a man who made such a significant contribution and to chronicle developments concerning this important radiologic finding. The Schatzki ring was described long ago, but its cause is poorly understood even today.

  3. Contraceptive vaginal rings: a review. (United States)

    Brache, Vivian; Faundes, Anibal


    Development efforts on contraceptive vaginal rings were initiated over 40 years ago based on two principles: the capacity of the vaginal epithelium to absorb steroids and the capacity of elastomers to release these hormones at a nearly constant rate. Numerous models of contraceptive vaginal rings (CVRs) have been studied, but only two have reached the market: NuvaRing, a combined ring that releases etonogestrel (ENG) and ethinylestradiol (EE), and Progering, a progesterone-releasing ring for use in lactating women. The main advantages of CVRs are their effectiveness (similar to or slightly better than the pill), ease of use without the need of remembering a daily routine, user's ability to control initiation and discontinuation, nearly constant release rate allowing for lower doses, greater bioavailability and good cycle control with the combined ring. The main disadvantages are related to the mode of delivery; CVRs may cause vaginal discharge and complaints, ring expulsion is not uncommon, the ring may be felt during coitus and vaginal insertion may be unpleasant for some women. The studies reviewed in this article provide evidence that CVRs are safe, effective and highly acceptable to women. There is no doubt that CVRs offer a new, effective contraceptive option to women, expanding their available choices of hormonal contraception. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Biomechanics of Corneal Ring Implants (United States)


    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619

  5. Biomechanics of Corneal Ring Implants. (United States)

    Daxer, Albert


    To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus.

  6. How Jupiter's Ring Was Discovered. (United States)

    Elliot, James; Kerr, Richard


    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  7. Constructions over localizations of rings

    Directory of Open Access Journals (Sweden)

    Alessandro Logar


    Full Text Available In this paper we construct a category of effective noetherian rings in which linear equations can be “solved”. This category is closed with respect to some important constructions like trascendental extensions, quotientations, finite products and localizations with respect to a large class of multiplicatively closed systems. Hence it gives a definition of “constructive” rings.

  8. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia


    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  9. Nonlinear Frequency Compression (United States)

    Scollie, Susan; Glista, Danielle; Seelisch, Andreas


    Frequency lowering technologies offer an alternative amplification solution for severe to profound high frequency hearing losses. While frequency lowering technologies may improve audibility of high frequency sounds, the very nature of this processing can affect the perceived sound quality. This article reports the results from two studies that investigated the impact of a nonlinear frequency compression (NFC) algorithm on perceived sound quality. In the first study, the cutoff frequency and compression ratio parameters of the NFC algorithm were varied, and their effect on the speech quality was measured subjectively with 12 normal hearing adults, 12 normal hearing children, 13 hearing impaired adults, and 9 hearing impaired children. In the second study, 12 normal hearing and 8 hearing impaired adult listeners rated the quality of speech in quiet, speech in noise, and music after processing with a different set of NFC parameters. Results showed that the cutoff frequency parameter had more impact on sound quality ratings than the compression ratio, and that the hearing impaired adults were more tolerant to increased frequency compression than normal hearing adults. No statistically significant differences were found in the sound quality ratings of speech-in-noise and music stimuli processed through various NFC settings by hearing impaired listeners. These findings suggest that there may be an acceptable range of NFC settings for hearing impaired individuals where sound quality is not adversely affected. These results may assist an Audiologist in clinical NFC hearing aid fittings for achieving a balance between high frequency audibility and sound quality. PMID:23539261

  10. Distributed Compressive Sensing (United States)


    more powerful algorithms like SOMP can be used. The ACIE algorithm is similar in spirit to other iterative estimation algorithms, such as turbo...Mitchell, “JPEG: Still image data compression standard,” Van Nostrand Reinhold , 1993. [11] D. S. Taubman and M. W. Marcellin, JPEG 2000: Image

  11. Temporal compressive sensing systems

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Bryan W.


    Methods and systems for temporal compressive sensing are disclosed, where within each of one or more sensor array data acquisition periods, one or more sensor array measurement datasets comprising distinct linear combinations of time slice data are acquired, and where mathematical reconstruction allows for calculation of accurate representations of the individual time slice datasets.

  12. Compression of Infrared images

    DEFF Research Database (Denmark)

    Mantel, Claire; Forchhammer, Søren


    This paper investigates the compression of infrared images with three codecs: JPEG2000, JPEG-XT and HEVC. Results are evaluated in terms of SNR, Mean Relative Squared Error (MRSE) and the HDR-VDP2 quality metric. JPEG2000 and HEVC perform fairy similar and better than JPEG-XT. JPEG2000 performs...

  13. Compressive CFAR radar detection

    NARCIS (Netherlands)

    Anitori, L.; Otten, M.P.G.; Rossum, W.L. van; Maleki, A.; Baraniuk, R.


    In this paper we develop the first Compressive Sensing (CS) adaptive radar detector. We propose three novel architectures and demonstrate how a classical Constant False Alarm Rate (CFAR) detector can be combined with ℓ1-norm minimization. Using asymptotic arguments and the Complex Approximate

  14. Centrifugal Gas Compression Cycle (United States)

    Fultun, Roy


    A centrifuged gas of kinetic, elastic hard spheres compresses isothermally and without flow of heat in a process that reverses free expansion. This theorem follows from stated assumptions via a collection of thought experiments, theorems and other supporting results, and it excludes application of the reversible mechanical adiabatic power law in this context. The existence of an isothermal adiabatic centrifugal compression process makes a three-process cycle possible using a fixed sample of the working gas. The three processes are: adiabatic mechanical expansion and cooling against a piston, isothermal adiabatic centrifugal compression back to the original volume, and isochoric temperature rise back to the original temperature due to an influx of heat. This cycle forms the basis for a Thomson perpetuum mobile that induces a loop of energy flow in an isolated system consisting of a heat bath connectable by a thermal path to the working gas, a mechanical extractor of the gas's internal energy, and a device that uses that mechanical energy and dissipates it as heat back into the heat bath. We present a simple experimental procedure to test the assertion that adiabatic centrifugal compression is isothermal. An energy budget for the cycle provides a criterion for breakeven in the conversion of heat to mechanical energy.

  15. Fingerprints in compressed strings

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Cording, Patrick Hagge


    In this paper we show how to construct a data structure for a string S of size N compressed into a context-free grammar of size n that supports efficient Karp–Rabin fingerprint queries to any substring of S. That is, given indices i and j, the answer to a query is the fingerprint of the substring S...

  16. Fingerprints in Compressed Strings

    DEFF Research Database (Denmark)

    Bille, Philip; Cording, Patrick Hagge; Gørtz, Inge Li


    The Karp-Rabin fingerprint of a string is a type of hash value that due to its strong properties has been used in many string algorithms. In this paper we show how to construct a data structure for a string S of size N compressed by a context-free grammar of size n that answers fingerprint queries...

  17. The Search for Ringed Exoplanets (United States)

    Kohler, Susanna


    Are planetary rings as common in our galaxy as they are in our solar system? A new study demonstrates how we might search for ringed exoplanets and then possibly finds one!Saturns Elsewhere?Artists illustration of the super ring system around exoplanet J1407b. This is the only exoplanet weve found with rings, but its not at all like Saturn. [Ron Miller]Our solar system is filled with moons and planetary rings, so it stands to reason that exoplanetary systems should exhibit the same features. But though weve been in the planet-hunting game for decades, weve only found one exoplanet thats surrounded by a ring system. Whats more, that system J1407b has enormous rings that are vastly different from the modest, Saturn-like rings that we might expect to be more commonplace.Have we not discovered ringed exoplanets just because theyre hard to identify? Or is it because theyre not out there? A team of scientists led by Masataka Aizawa (University of Tokyo) has set out to answer this question by conducting a systematic search for rings around long-period planet candidates.The transit light curve of KIC 10403228, shown with three models: the best-fitting planet-only model (blue) and the two best-fitting planet+ring models (green and red). [Aizawa et al. 2017]The Hunt BeginsWhy long-period planets? Rings are expected to be unstable as the planet gets closer to the central star. Whats more, the planet needs to be far enough away from the stars warmth for the icy rings to exist. The authors therefore select from the collection of candidate transiting planets 89 long-period candidates that might be able to host rings.Aizawa and collaborators then fit single-planet models (with no rings) to the light curves of these planets and search for anomalies curves that arent fit well by these standard models. Particularly suspicious characteristics include a long ingress/egress as the planet moves across the face of the star, and asymmetry of the transit shape.After applying a series of

  18. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer


    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  19. Compressed Sensing for Chemistry (United States)

    Sanders, Jacob Nathan

    Many chemical applications, from spectroscopy to quantum chemistry, involve measuring or computing a large amount of data, and then compressing this data to retain the most chemically-relevant information. In contrast, compressed sensing is an emergent technique that makes it possible to measure or compute an amount of data that is roughly proportional to its information content. In particular, compressed sensing enables the recovery of a sparse quantity of information from significantly undersampled data by solving an ℓ 1-optimization problem. This thesis represents the application of compressed sensing to problems in chemistry. The first half of this thesis is about spectroscopy. Compressed sensing is used to accelerate the computation of vibrational and electronic spectra from real-time time-dependent density functional theory simulations. Using compressed sensing as a drop-in replacement for the discrete Fourier transform, well-resolved frequency spectra are obtained at one-fifth the typical simulation time and computational cost. The technique is generalized to multiple dimensions and applied to two-dimensional absorption spectroscopy using experimental data collected on atomic rubidium vapor. Finally, a related technique known as super-resolution is applied to open quantum systems to obtain realistic models of a protein environment, in the form of atomistic spectral densities, at lower computational cost. The second half of this thesis deals with matrices in quantum chemistry. It presents a new use of compressed sensing for more efficient matrix recovery whenever the calculation of individual matrix elements is the computational bottleneck. The technique is applied to the computation of the second-derivative Hessian matrices in electronic structure calculations to obtain the vibrational modes and frequencies of molecules. When applied to anthracene, this technique results in a threefold speed-up, with greater speed-ups possible for larger molecules. The

  20. Robotically Assisted Single Anastomosis Duodenoileal Bypass after Previous Sleeve Gastrectomy Implementing High Valuable Technology for Complex Procedures

    Directory of Open Access Journals (Sweden)

    Ramon Vilallonga


    Full Text Available Staged bariatric procedures in high risk patients are a common used strategy for morbid obese patients nowadays. After previous sleeve gastrectomy, surgical treatments in order to complete weight loss or comorbidities improvements or resolutions are possible. One strategy is to perform a novel technique named SADI (single anastomosis duodenoileal bypass-sleeve. We present the technique for totally intracorporeal robotically assisted SADI using five ports and a liver retractor. We aim to see if the robotic technology offers more advantageous anastomosis and dissection obtained by the robotic approach in comparison to standard laparoscopy. The safety, feasibility, and reproducibility of a minimally invasive robotic surgical approach to complex abdominal operations such as SADI are discussed.


    Gil-Vernet Vila, José María


    To perform arterial or venous spleno-renal anastomoses, surgeons have so far systematically used the transperitoneal way whic is burdened by a high mortality an morbility percentage. On the basis of anatomo-surgical considerations, a retroperitoneal approach has been found reaching the hilus of the spleen via the lumbar region; the first arterial spleno-renal anastomosis by this way was performed in 1972 and the first venous spleno-renal anastomosis due to portal hipertension also by this way was performed in 1974, the alter proving to be the least aggresive by avoiding damaging the páncreas, the most surgical and direct for reaching the splenic vessels thereby enabling a better exposure and an easier performing of the anastomoses. By being retroperitoneal, the loss or infección of the ascitic liquid in the cirrhotic patient is prevented.

  2. In-vivo mitral annuloplasty ring transducer: implications for implantation and annular downsizing. (United States)

    Siefert, Andrew W; Touchton, Steven A; McGarvey, Jeremy R; Takebayashi, Satoshi; Rabbah, Jean Pierre M; Jimenez, Jorge H; Saikrishnan, Neelakantan; Gorman, Robert C; Gorman, Joseph H; Yoganathan, Ajit P


    Mitral annuloplasty has been a keystone to the success of mitral valve repair in functional mitral regurgitation. Understanding the complex interplay between annular-ring stresses and left ventricular function has significant implications for patient-ring selection, repair failure, and patient safety. A step towards assessing these challenges is developing a transducer that can be implanted in the exact method as commercially available rings and can quantify multidirectional ring loading. An annuloplasty ring transducer was developed to measure stresses at eight locations on both the in-plane and out-of-plane surfaces of an annuloplasty ring's titanium core. The transducer was implanted in an ovine subject using 10 sutures at near symmetric locations. At implantation, the ring was observed to undersize the mitral annulus. The flaccid annulus exerted both compressive (-) and tensile stresses (+) on the ring ranging from -3.17 to 5.34 MPa. At baseline hemodynamics, stresses cyclically changed and peaked near mid-systole. Mean changes in cyclic stress from ventricular diastole to mid-systole ranged from -0.61 to 0.46 MPa (in-plane direction) and from -0.49 to 1.13 MPa (out-of-plane direction). Results demonstrate the variability in ring stresses that can be introduced during implantation and the cyclic contraction of the mitral annulus. Ring stresses at implantation were approximately 4 magnitudes larger than the cyclic changes in stress throughout the cardiac cycle. These methods will be extended to ring transducers of differing size and geometry. Upon additional investigation, these data will contribute to improved knowledge of annulus-ring stresses, LV function, and the safer development of mitral repair techniques. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Single layer versus double layer suture anastomosis of the gastrointestinal tract. (United States)

    Sajid, Muhammad S; Siddiqui, Muhammed Rafay Sameem; Baig, Mirza K


    Gastrointestinal anastomosis (GIA) is an essential step to maintain the continuity of gastrointestinal tract following intestinal resection. GIA is still a source of significant controversy among surgeons due to the use of variety of approaches. Adequate apposition by single layer or double layer anastomosis may affect outcome after GIA OBJECTIVES: The objective of this review is to compare the effectiveness of single layer GIA (SGIA) versus double layer GIA (DGIA) being used in general surgery. The particular question we would attempt to answer will be; is single layer hand made GIA in surgical patients is as effective as double layer? The CCCG (Colorectal Cancer Cochrane Group) Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1, 2011), MEDLINE (until April 2011) , EMBASE ( The Intelligent Gateway to Biomedical & Pharmacological Information until April 2011), LILACS (The Latin American and Caribbean Health Sciences Library until April 2011 ) and Science Citation Index Expanded (SCI-E until April 2011) using the medical subject headings (MeSH) terms were searched without date, language or age restrictions. Randomised, controlled trials comparing the effectiveness of SGIA versus DGIA DATA COLLECTION AND ANALYSIS: At least two review authors independently scrutinised search results, selected eligible studies and extracted data. Seven randomised, controlled trials encompassing 842 patients undergoing SGIA versus DGIA were retrieved from the electronic databases. There were 408 patients in the SGIA group and 432 patients in the DGIA group. All included studies were small, with sample sizes ranging from 60 to 172. There was no heterogeneity among the included trials. Therefore, in the fixed effects model, incidence of anastomotic dehiscence, peri-operative complications and mortality was statistically equivalent between two techniques of GIA. Average hospital stay following SGIA and DGIA was also

  4. Pancreatic Transplantation and Subsequent Graft Surveillance by Pancreatic Portal–Enteric Anastomosis and Temporary Venting Jejunostomy (United States)

    Zibari, Gazi B.; Boykin, Kevin N.; Sawaya, David E.; Abreo, Kenneth D.; Gonzalez, Enrique; Gebel, Howard M.; McDonald, John C.


    Objective To evaluate portal–enteric (PE) pancreas and kidney transplantation with venting jejunostomy (VJ) for its efficacy, safety, and reproducibility. Summary Background Data Simultaneous pancreas and kidney transplantation for patients with long-standing insulin-dependent diabetes mellitus that progresses to renal failure has revolutionized their treatment and quality of life. A current clinical focus is to refine the technical aspects of this procedure. Simultaneous pancreas and kidney transplantation with PE anastomosis with VJ appears to offer several advantages over bladder drainage. VJ allows initial decompression of the enteric anastomosis, monitoring of pancreatic function by ostomy amylase, and simple access for endoscopic evaluation and biopsy of the allograft. Methods Simultaneous pancreas and kidney transplantation with VJ was performed in 21 patients from December 1996 to October 2000 at Willis Knighton/LSU Regional Transplant Center. All patients had long-standing insulin-dependent diabetes mellitus and subsequent renal failure. They were evaluated at the time of surgery by a multidisciplinary transplant team and monitored for numerous factors, including length of hospital stay, immunosuppressive regimen, and ischemia times. All patients had intermittent visual and biochemical evaluation of pancreatic secretions monitored by means of the VJ. Results Of the 21 patients, 10 were women and 11 were men. Four patients were black and 17 were white. The mean age at transplantation was 38 years; average human leukocyte antigen (HLA) match was one; and average cold ischemia time was 12 hours. The median hospital stay was 16 days. Four episodes of postoperative bleeding requiring exploration occurred in four patients. Postoperative wound infections developed in four patients. There were 12 episodes of rejection in nine patients. All patients with suspected acute pancreatic rejection underwent endoscopy by means of the VJ and duodenal biopsy for evaluation

  5. Postpartum complications in a patient with a previous proctocolectomy and ileo-pouch-anal anastomosis (IPAA) for ulcerative colitis


    Spina, Vincenzo; Giovannini, Massimo; Fabiani, Cristina; Vetrano, Giuseppe; Bagolan, Pietro; Colizza, Sergio; Aleandri, Vincenzo


    This case report regards pregnancy and delivery of a patient who had undergone proctocolectomy and ileo-pouch-anal-anastomosis (IPAA) for ulcerative colitis. The patient delivered through cesarean section and experienced serious complications postpartum. Such complications have been described in association with Chron’s disease and have never been described after proctocolectomy and IPAA for ulcerative colitis. This case report suggests that the limit between these two diseases is not sharp.

  6. One-stitch anastomosis through the skin with bicanalicular intubation:a modified approach for repair of bicanalicular laceration

    Directory of Open Access Journals (Sweden)

    Hai Tao


    Full Text Available AIM: To evaluate the efficacy and safety of one-stitch anastomosis through the skin with bicanalicular silicone tube intubation in repairing of bicanalicular laceration.METHODS:The clinical data of 15 consecutive patients with both superior and inferior canalicular laceration in one eye who underwent surgical repair using one-stitch anastomosis through the skin and bicanalicular stent were retrospective studied. All the operations were performed under surgical microscope, 5-0 silk sutures were used and were with bicanalicular silicone tube (diameter was 8mm intubation, for one lacerated canaliculi one-stitch anastomosis through the skin. The stents were left in place for 3 months postoperatively and then removed. The follow-up period was 3 - 36 months (average 14 months.RESULTS:In 15 patients, 13 patients were cured entirely, 1 patient was meliorated, 1 patient with no effects. All patients had got good recovery of eyelid laceration with no traumatic deformity in eyelid and canthus. Complication was seen in one case, for not followed the doctor’s guidance to come back to hospital to had the suture removed on the 7th day after operation, when he came at the 15th day, the inferior canalicular wall and eyelid skin were corroded by the suture caused 2mm wound, and the inside silicone tube was exposed, a promptly repair with 10-0 nylon suture was done, the wound healed in a week. There were no early tube protrusions and punctal slits in the patients.CONCLUSION:One-stitch anastomosis through the skin with bicanalicular silicone tube intubation is a good method in repair of bicanalicular laceration in one eye, the cut ends can be anastomosed directly, and with excellent cosmetic results, it is acceptable for the patients. For there is no suture remained in the wound permanently, so there is no suture-related granuloma which may cause obstruction or stenosis of canaliculi. It is simple, economical, effective and safe.

  7. Ten years of experience with Parks' coloanal sleeve anastomosis for the treatment of post-irradiation rectovaginal fistula

    Energy Technology Data Exchange (ETDEWEB)

    Mowacki, M.P. (Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Warsaw (Poland). Dept. of Surgical Oncology)


    Twenty-four cases of coloanal sleeve anastomosis for the repair of rectovaginal post-irradiation fistula are described. All patients were previously irradiated because of carcinoma of the uterine cervix. Eleven patients had simultaneous repair of vesicovaginal fistula. One postoperative death was observed. Of the 23 surviving patients, functional results were good in 18. In 16 patients with difficult stripping of the rectal mucosa, surgical curettage was performed. The latter procedure is suggested as a useful method in relevant cases. (author).

  8. A new training model for robot-assisted urethrovesical anastomosis and posterior muscle-fascial reconstruction: the Verona training technique. (United States)

    Cacciamani, G; De Marco, V; Siracusano, S; De Marchi, D; Bizzotto, L; Cerruto, M A; Motton, G; Porcaro, A B; Artibani, W


    A training model is usually needed to teach robotic surgical technique successfully. In this way, an ideal training model should mimic as much as possible the "in vivo" procedure and allow several consecutive surgical simulations. The goal of this study was to create a "wet lab" model suitable for RARP training programs, providing the simulation of the posterior fascial reconstruction. The second aim was to compare the original "Venezuelan" chicken model described by Sotelo to our training model. Our training model consists of performing an anastomosis, reproducing the surgical procedure in "vivo" as in RARP, between proventriculus and the proximal portion of the esophagus. A posterior fascial reconstruction simulating Rocco's stitch is performed between the tissues located under the posterior surface of the esophagus and the tissue represented by the serosa of the proventriculus. From 2014 to 2015, during 6 different full-immersion training courses, thirty-four surgeons performed the urethrovesical anastomosis using our model and the Sotelo's one. After the training period, each surgeon was asked to fill out a non-validated questionnaire to perform an evaluation of the differences between the two training models. Our model was judged the best model, in terms of similarity with urethral tissue and similarity with the anatomic unit urethra-pelvic wall. Our training model as reported by all trainees is easily reproducible and anatomically comparable with the urethrovesical anastomosis as performed during radical prostatectomy in humans. It is suitable for performing posterior fascial reconstruction reported by Rocco. In this context, our surgical training model could be routinely proposed in all robotic training courses to develop specific expertise in urethrovesical anastomosis with the reproducibility of the Rocco stitch.

  9. Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Charles Y., E-mail:; Tandberg, Daniel J.; Rosenberg, Michael D.; Miller, Michael J.; Suhocki, Paul V.; Smith, Tony P. [Duke University Medical Center, Division of Vascular and Interventional Radiology (United States)


    Purpose: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. Methods: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metal stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. Results: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). Conclusion: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.

  10. Free jejunal graft for esophageal reconstruction using end-to-side vascular anastomosis and extended pharyngo-jejunostomy. (United States)

    Lee, Hyun-Sung; Park, Seong Yong; Jang, Hee-Jin; Kim, Moon Soo; Lee, Jong Mog; Zo, Jae Ill


    Pharyngo-esophageal reconstruction using free jejunal grafts (FJGs) has been widely used, but the procedure is technically demanding and requires the involvement of multiple departments. We performed simplified reconstruction with FJGs using end-to-side vascular anastomosis and extended pharyngo-jejunostomy. The jejunal artery and vein were anastomosed to the neck vessels in an end-to-side fashion without microvascular anastomosis. Pharyngo-jejunostomy with extended end-to-end anastomosis was performed to reduce size mismatch. We retrospectively analyzed the medical records of 32 patients diagnosed with pharyngeal, esophageal, or pyriform sinus cancer who received a FJG. The mean age was 61.5±9.4 years, and there were 25 male patients. Jejunal vessels were commonly anastomosed to the right common carotid artery and the right internal jugular vein (22, 68.8%). The mean ischemic times of the FJG and carotid artery clamping time were 46.5±8.1 and 15.8±4.4 minutes, respectively. During the procedure, 3 patients suffered from inadequate reperfusion of the FJG requiring removal of the initial graft and replacement with another FJG. There were no neurologic complications, postoperative deaths, or adverse events directly related to FJG except for leakage of the pharyngo-jejunostomy site in 1 patient, which was primarily repaired. During the follow-up period, 5 patients (15.6%) suffered from dysphagia, but only 3 patients had evidence of anastomotic strictures at the jejuno-esophagostomy site. Thirteen patients (40.6%) received postoperative adjuvant radiotherapy. Our technique of FJG with end-to-side vascular anastomosis and extended pharyngo-jejunostomy is simple and safe. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Computed Tomographic Angiography-Based Planning of Bipedicled DIEP Flaps with Intraflap Crossover Anastomosis: An Anatomical and Clinical Study. (United States)

    Kim, So Young; Lee, Kyeong-Tae; Mun, Goo-Hyun


    When using deep inferior epigastric artery perforator (DIEP) flaps in breast reconstruction, harvesting bipedicled flaps can be a valuable option in cases requiring the transfer of a large portion of harvested flaps. Connecting the bilateral deep inferior epigastric arteries (DIEAs) by intraflap crossover anastomosis is one of the most popular methods of constructing bipedicled DIEP flaps. Planning the primary and secondary pedicle configurations for reliable intraflap crossover anastomosis is crucial. To achieve this, detailed anatomical DIEA information might be helpful. However, meticulous planning of bipedicled DIEP flaps based on computed tomographic angiography has not been reported. Detailed anatomical investigation of DIEA branches was conducted using computed tomographic angiographs of 100 hemiabdomens. Thirty-eight prospectively collected patients who underwent breast reconstruction using bipedicled DIEP flaps with intraflap crossover under computed tomographic angiography-based planning were reviewed. Three intramuscular DIEA branching patterns with distinct branch point topography, branch diameters, and superior continuations cranial to sizable perforators were observed. In the prospective clinical study, a primary pedicle with a recipient branch for intraflap crossover anastomosis could be specified preoperatively using computed tomographic angiography-based anatomical data of the pedicles, including size of DIEA branches or their superior continuation and size of perforators. In all cases, the bipedicle configuration was easily achieved as planned on computed tomographic angiography, and secure perfusion of the entire flap was achieved. The authors' results suggest that computed tomographic angiography provides detailed anatomical DIEA information, and comprehensive analysis of these data allows precise planning of bipedicle configurations with intraflap crossover anastomosis in DIEP flaps. Therapeutic, IV.


    Directory of Open Access Journals (Sweden)

    L. D. Roman


    Full Text Available Background. How to derive urine is stemmed from removal of the bladder and from the necessity of its disengaging from the process of urination. Most surgeons prefer to do incontinent urine derivation in elderly and senile patients.Subjects and methods. In 2007 to 2009, the Leningrad Regional Oncology Dispensary treated 103 patients with diseases requiring the bladder be removed. All these patients underwent cystectomy as an independent operation or one of the surgical stages, followed by incontinent urine derivation described by Bricker. The patients were divided into 2 groups: 1 Bricker-type end-to-side ureteroileal anastomosis; 2 Wallace-type one. Group 1 comprised 50 patients: 37 (74 % women and 13 (26 % men; Group 2 included 53 patients: 48 (90.6 % women and 5 (9.6 % men. These were elderly and senile patients aged 60 to 79 years (mean age 65 ± 3.71.Results. In Group 1, 36 (72 % patients were preoperatively diagnosed as having hydroureteronephrosis (HUN. Of them, 23 (64% patients underwent preoperative percutaneous puncture nephrostomy (PPN. In Group 2, HUN was diagnosed in 43 (81 % patients; of them 27 (63 % had PPN. Complications and resurgeries were more common in Group 1 (p < 0.001. In Group 2, there were a larger number of cases of incompetence of the ureteroileal anastomosis. This complication required no surgical correction, but a longer drainage standing.Conclusion. The Bricker operation is the safest urine derivation in elderly and senile patients after surgery involving cystectomy. Wallacetype ureteroileal anastomosis during the Bricker operation is accompanied by a considerable reduction in the number of early and late postoperative complications and resurgeries. Wallace-type ureteroileal anastomosis is considered the method of choice in cancer patients.


    Directory of Open Access Journals (Sweden)

    L. D. Roman


    Full Text Available Background. How to derive urine is stemmed from removal of the bladder and from the necessity of its disengaging from the process of urination. Most surgeons prefer to do incontinent urine derivation in elderly and senile patients.Subjects and methods. In 2007 to 2009, the Leningrad Regional Oncology Dispensary treated 103 patients with diseases requiring the bladder be removed. All these patients underwent cystectomy as an independent operation or one of the surgical stages, followed by incontinent urine derivation described by Bricker. The patients were divided into 2 groups: 1 Bricker-type end-to-side ureteroileal anastomosis; 2 Wallace-type one. Group 1 comprised 50 patients: 37 (74 % women and 13 (26 % men; Group 2 included 53 patients: 48 (90.6 % women and 5 (9.6 % men. These were elderly and senile patients aged 60 to 79 years (mean age 65 ± 3.71.Results. In Group 1, 36 (72 % patients were preoperatively diagnosed as having hydroureteronephrosis (HUN. Of them, 23 (64% patients underwent preoperative percutaneous puncture nephrostomy (PPN. In Group 2, HUN was diagnosed in 43 (81 % patients; of them 27 (63 % had PPN. Complications and resurgeries were more common in Group 1 (p < 0.001. In Group 2, there were a larger number of cases of incompetence of the ureteroileal anastomosis. This complication required no surgical correction, but a longer drainage standing.Conclusion. The Bricker operation is the safest urine derivation in elderly and senile patients after surgery involving cystectomy. Wallacetype ureteroileal anastomosis during the Bricker operation is accompanied by a considerable reduction in the number of early and late postoperative complications and resurgeries. Wallace-type ureteroileal anastomosis is considered the method of choice in cancer patients.

  14. TEM Video Compressive Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Andrew; Kovarik, Libor; Abellan, Patricia; Yuan, Xin; Carin, Lawrence; Browning, Nigel D.


    One of the main limitations of imaging at high spatial and temporal resolution during in-situ TEM experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing methods [1, 2, 3, 4] to increase the framerate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integrated into a single camera frame during the acquisition process, and then extracted upon readout using statistical compressive sensing inversion. Our simulations show that it should be possible to increase the speed of any camera by at least an order of magnitude. Compressive Sensing (CS) combines sensing and compression in one operation, and thus provides an approach that could further improve the temporal resolution while correspondingly reducing the electron dose rate. Because the signal is measured in a compressive manner, fewer total measurements are required. When applied to TEM video capture, compressive imaging couled improve acquisition speed and reduce the electron dose rate. CS is a recent concept, and has come to the forefront due the seminal work of Candès [5]. Since the publication of Candès, there has been enormous growth in the application of CS and development of CS variants. For electron microscopy applications, the concept of CS has also been recently applied to electron tomography [6], and reduction of electron dose in scanning transmission electron microscopy (STEM) imaging [7]. To demonstrate the applicability of coded aperture CS video reconstruction for atomic level imaging, we simulate compressive sensing on observations of Pd nanoparticles and Ag nanoparticles during exposure to high temperatures and other environmental conditions

  15. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi


    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  16. Hybrid silicon ring lasers (United States)

    Liang, Di; Fiorentino, Marco; Bowers, John E.; Beausoleil, Raymond G.


    Hybrid silicon platform provides a solution to integrate active components (lasers, amplifiers, photodetectors, etc.) with passive ones on the same silicon substrate, which can be used for building an optical interconnect system. Owing to the advantages in footprint, power consumption, and high-speed modulation, hybrid silicon microring lasers have been demonstrated as a potential candidate for on-chip silicon light source. In this paper we review the progress to improve the performance of recently demonstrated compact microring lasers with ring diameter of 50 μm. A simple approach to enhance optical mode and electron-hole recombination, which results in threshold reduction and efficiency improvement is developed. This is done by appropriately undercutting the multiple quantum well (MQW) region to force carriers to flow towards the outer edge of the microring for better gain/optical mode overlap. We observe a reduction of the threshold of over 20% and up to 80% output power enhancement. The model and the experimental results highlight the benefits, as well as the negative effects from excessive undercutting, including lower MQW confinement, higher modal loss and higher thermal impedance. A design rule for MQW undercutting is therefore provided. Application as on-chip optical interconnects is discussed from a system perspective.

  17. Ion Rings for Magnetic Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Greenly, John, B.


    This Final Technical Report presents the results of the program, Ion Rings for Magnetic Fusion, which was carried out under Department of Energy funding during the period August, 1993 to January, 2005. The central objective of the program was to study the properties of field-reversed configurations formed by ion rings. In order to reach this objective, our experimental program, called the Field-reversed Ion Ring Experiment, FIREX, undertook to develop an efficient, economical technology for the production of field-reversed ion rings. A field-reversed configuration (FRC) in which the azimuthal (field-reversing) current is carried by ions with gyro-radius comparable to the magnetic separatrix radius is called a field-reversed ion ring. A background plasma is required for charge neutralization of the ring, and this plasma will be confined within the ring's closed magnetic flux. Ion rings have long been of interest as the basis of compact magnetic fusion reactors, as the basis for a high-power accelerator for an inertial fusion driver, and for other applications of high power ion beams or plasmas of high energy density. Specifically, the FIREX program was intended to address the longstanding question of the contribution of large-orbit ions to the observed stability of experimental FRCs to the MHD tilt mode. Typical experimental FRCs with s {approx} 2-4, where s is the ratio of separatrix radius to ion gyro-radius, have been stable to tilting, but desired values for a fusion reactor, s > 20, should be unstable. The FIREX ring would consist of a plasma with large s for the background ions, but with s {approx} 1 for the ring ions. By varying the proportions of these two populations, the minimum proportion of large-orbit ions necessary for stability could be determined. The incorporation of large-orbit ions, perhaps by neutral-beam injection, into an FRC has been advanced for the purpose of stabilizing, heating, controlling angular momentum, and aiding the formation

  18. Early Mobilization after Free-flap Transfer to the Lower Extremities: Preferential Use of Flow-through Anastomosis. (United States)

    Miyamoto, Shimpei; Kayano, Shuji; Fujiki, Masahide; Chuman, Hirokazu; Kawai, Akira; Sakuraba, Minoru


    Prolonged bed rest and elevation have traditionally been considered necessary after free-flap transfer to the lower extremities. In this retrospective study, we tried to mobilize patients early after free-flap transfer to the lower extremity by means of flow-through anastomosis for both arteries and veins. This study included 13 consecutive patients who underwent immediate free-flap transfer after wide resection of soft-tissue tumors of the lower extremity from March 2012 through July 2013. The defects were above the knee in 5 patients and below the knee in 8 patients. In all patients, flow-through anastomosis was used for both arteries and veins. The patients were mobilized starting on the first postoperative day, and their activities of daily life were gradually expanded, depending on the wound conditions. Postoperative complications and the progression of their activities of daily life were investigated retrospectively. No anastomotic failure or take back occurred. Partial flap necrosis occurred in 1 patient because of a poor perforator but was unrelated to early mobilization. All patients could move to wheelchairs on the first postoperative day. Within 1 week, 12 of 13 patients could start dangling and 10 of 13 patients could start ambulating. This study demonstrates that early mobilization after free-flap transfer to the lower extremity is made possible by flow-through anastomosis for both arteries and veins. Flow-through flaps have stable circulation from the acute phase and can tolerate early dangling and ambulation.

  19. Time resolved spectroscopy of shock compressed liquids (United States)

    Ogilvie, K.; Duvall, G. E.


    An experimental procedure has been developed for using a rotating mirror camera to record time-resolved absorption spectra of liquids undergoing shock compression. Experimental records have been obtained for cells containing liquid carbon disulfide shocked, through reverberation, to peak pressures of 55, 80, 100 and 120 kbar. Experiments have been performed using both reflected and transmitted light. Time and spectral resolution were limited to approximately 30 nsec and 30 Å; spectral range was from 4000 to 2500 Å. This initial work on carbon disulfide shows it to become highly absorptive when shocked to low pressures of 8 to 14 kbar, and to progressively become a better broadband reflector as the pressure in a thin layer rings up to the final value. A decay in the reflectivity after reaching peak pressure in the 120 kbar experiment may indicate chemical decomposition. This is in accord with earlier results of S. A. Sheffield based on measurement of flow parameters.

  20. Ring-Ringlet Interactions in Saturn's C Ring (United States)

    Rappaport, N. J.


    The overall obejective of this work is to derive a theoretical model for the formation of gaps harboring isolated ringlets in order to explain the presence of such features in Saturn's C ring and Cassini division.

  1. Origin and Evolution of Saturn's Ring System


    Charnoz, Sebastien; Dones, Luke; Esposito, Larry W.; Estrada, Paul R.; Hedman, Matthew M.


    The origin and long-term evolution of Saturn's rings is still an unsolved problem in modern planetary science. In this chapter we review the current state of our knowledge on this long-standing question for the main rings (A, Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During the Voyager era, models of evolutionary processes affecting the rings on long time scales (erosion, viscous spreading, accretion, ballistic transport, etc.) had suggested that Saturn's rings are...

  2. Soft Congruence Relations over Rings

    Directory of Open Access Journals (Sweden)

    Xiaolong Xin


    Full Text Available Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively.

  3. Codes over infinite family of rings : Equivalence and invariant ring (United States)

    Irwansyah, Muchtadi-Alamsyah, Intan; Muchlis, Ahmad; Barra, Aleams; Suprijanto, Djoko


    In this paper, we study codes over the ring Bk=𝔽pr[v1,…,vk]/(vi2=vi,∀i =1 ,…,k ) . For instance, we focus on two topics, i.e. characterization of the equivalent condition between two codes over Bk using a Gray map into codes over finite field 𝔽pr, and finding generators for invariant ring of Hamming weight enumerator for Euclidean self-dual codes over Bk.

  4. Comparação entre dois fios de sutura não absorvíveis na anastomose traqueal término-terminal em cães Comparison of two nonabsorbable suture materials in the end-to-end tracheal anastomosis in dogs

    Directory of Open Access Journals (Sweden)

    Sheila Canevese Rahal


    Full Text Available Doze cães sem raça definida, com idade variando entre 1 e 6 anos e peso de 6 a 20kg, foram submetidos a ressecção traqueal e anastomose término-terminal, na qual foram testados os fios poliéster trançado não capilar e náilon monofilamento. Seis animais, cada três com um mesmo tipo de fio de sutura, sofreram a excisão equivalente a três anéis traqueais. Com 15 dias foi executada uma nova intervenção onde se ressecou o equivalente a mais seis anéis, perfazendo um total de nove. Ao final de outros 15 dias foram sacrificados. Os outros seis animais, cada três com um mesmo tipo de fio, foram submetidos à excisão equivalente a três anéis traqueais e mantidos por 43 dias. As traquéias foram avaliadas por exames clínicos, radiográficos, macroscópicos e histopatológicos. O fio de náilon monofilamento apresentou menos reação tecidual do que o poliéster trançado não capilar, promoveu uma anastomose segura e com menor chance de formação de granuloma.Twelve mongrel dogs, with age between 1 and 6 years old and weight between 12 and 40 pounds, were submitted to tracheal resection and end-to-end anastomosis in which were tested braided polyester no capillary and monofilament nylon materiais. Six animais, every threeones with a same type of suture material, suffered the excision equivalent to three tracheal rings. A new intervention was performed with fifteen days, in which the equivalent of more six tracheal rings were removed, completing the total of nine. At the end of more fifteen days they were sacrificed. The other six animals, every three with a same type of suture material, were submitted to the excision equivalent to three tracheal rings and maintained for 43 days. The tracheal anastomosis were evaluated to clinic, radiographic, macroscopic and histopathologic studies. The monofilament nylon material exhibited less reaction than polyester and promoted a secure anastomosis with less risk of granuloma formation.

  5. Artifact reduction of compressed images and video combining adaptive fuzzy filtering and directional anisotropic diffusion

    DEFF Research Database (Denmark)

    Nadernejad, Ehsan; Forchhammer, Søren; Korhonen, Jari


    and ringing artifacts, we have applied directional anisotropic diffusion. Besides that, the selection of the adaptive threshold parameter for the diffusion coefficient has also improved the performance of the algorithm. Experimental results on JPEG compressed images as well as MJPEG and H.264 compressed......Fuzzy filtering is one of the recently developed methods for reducing distortion in compressed images and video. In this paper, we combine the powerful anisotropic diffusion equations with fuzzy filtering in order to reduce the impact of artifacts. Based on the directional nature of the blocking...

  6. Compressive Ulnar Neuropathy Caused by Olecranon Bursitis and Concomitant Epidermal Cyst: A Case Report. (United States)

    Yamazaki, Hiroshi; Shinone, Michitaka; Kato, Hiroyuki


    Epidermal cyst is a dermal or subcutaneous epithelial cyst that contains keratin and is lined by true epidermis. Although extremely rare, it can cause pathology including nerve compression syndrome. We report a rare case of ulnar nerve compression in the elbow that was caused by olecranon bursitis and concomitant epidermal cyst in a 67-year-old man. The ulnar nerve was immediately adjacent to the olecranon bursa and was significantly compressed. There was no connection between the tumor and the ulnar nerve. Pain, numbness, and weakness in his ring and little fingers disappeared after resection of the cyst and bursa.

  7. Compressive Spectral Renormalization Method

    CERN Document Server

    Bayindir, Cihan


    In this paper a novel numerical scheme for finding the sparse self-localized states of a nonlinear system of equations with missing spectral data is introduced. As in the Petviashivili's and the spectral renormalization method, the governing equation is transformed into Fourier domain, but the iterations are performed for far fewer number of spectral components (M) than classical versions of the these methods with higher number of spectral components (N). After the converge criteria is achieved for M components, N component signal is reconstructed from M components by using the l1 minimization technique of the compressive sampling. This method can be named as compressive spectral renormalization (CSRM) method. The main advantage of the CSRM is that, it is capable of finding the sparse self-localized states of the evolution equation(s) with many spectral data missing.

  8. Regional diagnosis of lymphoedema and selection of sites for lymphaticovenular anastomosis using elastography

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, M., E-mail: [Department of Plastic Surgery and Reconstructive Surgery, University of Tokyo, Tokyo (Japan); Hayashi, Y. [Department of Plastic Surgery and Reconstructive Surgery, University of Tokyo, Tokyo (Japan); Murai, N. [Department of Vascular Surgery, Saiseikai Kawaguchi Hospital, Saitama, Saitamaken (Japan); Moriguchi, H.; Iida, T.; Hara, H.; Todokoro, T.; Narushima, M.; Uchida, G.; Koshima, I. [Department of Plastic Surgery and Reconstructive Surgery, University of Tokyo, Tokyo (Japan)


    Aim: To evaluate the use of ultrasound elastography as a basis for determining the most appropriate sites for lymphaticovenular anastomosis (LVA) for treatment of lymphoedema. Materials and methods: Preoperative elastography and LVA were performed in 11 patients (11 legs) with leg lymphoedema, including two cases of primary oedema and nine of secondary oedema. Results: The mean number of LVAs applied per leg was 4.4 (range 3-7). The mean reduction in the leg circumference was 91.7%, and 10 of the 11 cases (90.0%) were improved. Hardness was reduced from a mean of 1.6 before surgery to 0.9 after surgery, and improvement was also noted in 10 cases (90.9%). The severity of oedema was determined in five regions in each leg, and was classified as elastography stage (ES) 0 in 11 regions, ES1 in 23, ES2 in 15, and ES3 in six. Conclusions: These results demonstrate the value of ultrasound elastography for the diagnosis of early-stage lymphoedema and determination of LVA sites. This is the first report of diagnosis of lymphoedema using elastography and the findings suggest that this procedure followed by LVA could be used as a new therapeutic method for early-stage lymphoedema.

  9. Handling difficult anastomosis. Tips and tricks in obese patients and narrow pelvis

    Directory of Open Access Journals (Sweden)

    Srinivas Samavedi


    Full Text Available Vesico-urethral anastomosis (VUA is a technically challenging step in robotic-assisted laparoscopic prostatectomy (RALP in obese individuals. We describe technical modifications to facilitate VUA encountered in obese individuals and in patients with a narrow pelvis. A Pubmed literature search was performed between 2000 and 2012 to review all articles related to RALP, obesity and VUA for evaluation of technique, complications and outcomes of VUA in obese individuals. In addition to the technical modifications described in the literature, we describe our own experience to encounter the technical challenges induced by obesity and narrow pelvis. In obese patients, technical modifications like use of air seal trocar technology, steep Trendlenburg positioning, bariatric trocars, alterations in trocar placement, barbed suture and use of modified posterior reconstruction facilitate VUA in robotic-assisted radical prostatectomy. The dexterity of the robot and the technical modifications help to perform the VUA in challenging patients with lesser difficulty. The experience of the surgeon is a critical factor in outcomes in these technically challenging patients, and obese individuals are best avoided during the initial phase of the learning curve.

  10. Smart tissue anastomosis robot (STAR): a vision-guided robotics system for laparoscopic suturing. (United States)

    Leonard, Simon; Wu, Kyle L; Kim, Yonjae; Krieger, Axel; Kim, Peter C W


    This paper introduces the smart tissue anastomosis robot (STAR). Currently, the STAR is a proof-of-concept for a vision-guided robotic system featuring an actuated laparoscopic suturing tool capable of executing running sutures from image-based commands. The STAR tool is designed around a commercially available laparoscopic suturing tool that is attached to a custom-made motor stage and the STAR supervisory control architecture that enables a surgeon to select and track incisions and the placement of stitches. The STAR supervisory-control interface provides two modes: A manual mode that enables a surgeon to specify the placement of each stitch and an automatic mode that automatically computes equally-spaced stitches based on an incision contour. Our experiments on planar phantoms demonstrate that the STAR in either mode is more accurate, up to four times more consistent and five times faster than surgeons using state-of-the-art robotic surgical system, four times faster than surgeons using manual Endo360(°)®, and nine times faster than surgeons using manual laparoscopic tools.

  11. Gastrojejunal Anastomosis Complications and Their Management after Laparoscopic Roux-en-Y Gastric Bypass

    Directory of Open Access Journals (Sweden)

    Yannick Fringeli


    Full Text Available Background. Complications at the gastrojejunal anastomosis after laparoscopic Roux-en-Y gastric bypass (LRYGB are challenging in terms of diagnosis, therapy, and prevention. This study aims at identifying these complications and discussing their management. Methods. Data of 228 patients who underwent a LRYGB between October 2008 and December 2011 were reviewed retrospectively to evaluate the frequency and treatment of complications such as stenoses, marginal ulcers, perforated marginal ulcers, or anastomotic leaks related to the operation. Results. Follow-up information was available for 209 patients (91.7% with a median follow-up of 38 months (range 24–62 months. Of these patients 16 patients (7.7% experienced complications at the gastrojejunostomy. Four patients (1.9% had stenoses and 12 patients (5.7% marginal ulcers, one of them with perforation (0.5%. No anastomotic leaks were reported. One case with perforated ulcer and one with recurrent ulcers required surgical revision. Conclusion. Gastrojejunal anastomotic complications are frequent and occur within the first few days or up to several years after surgery. Stenoses or marginal ulcers are usually successfully treated nonoperatively. Laparoscopic repair, meanwhile, is an appropriate therapeutic option for perforated ulcers.

  12. Hepaticocystic duct and a rare extra-hepatic "cruciate" arterial anastomosis: a case report

    Directory of Open Access Journals (Sweden)

    Abeysuriya Vasitha


    Full Text Available Abstract Introduction The variations in the morphological characteristics of the extra-hepatic biliary system are interesting. Case presentation During the dissection of cadavers to study the morphological characteristics of the extra-hepatic biliary system, a 46-year-old male cadaver was found to have drainage of the common hepatic duct drains directly into the gall bladder neck. The right and left hepatic ducts were not seen extra-hepatically. Further drainage of the bile away from the gallbladder and into the duodenum was provided by the cystic duct. Formation of the common bile duct by the union of the common hepatic duct and cystic duct was absent. Further more the right hepatic artery was found to be communicating with the left hepatic artery by a "bridging artery" after giving rise to the cystic artery. An accessory hepatic artery originated from the "bridging artery" forming a "cruciate" hepatic arterial anastomosis. Conclusion Combination of a Hepaticocystic duct and an aberrant variation in the extra-hepatic arterial system is extremely rare.

  13. Cavopulmonary Anastomosis in a Patient With Arrhythmogenic Right Ventricular Cardiomyopathy With Severe Right Ventricular Dysfunction. (United States)

    Vaidyanathan, Swaminathan; Kothandam, Sivakumar; Kumar, Rajesh; Indrajith, Sujatha Desai; Agarwal, Ravi


    A 26-year-old lady presented with exertional dyspnea, palpitations, central cyanosis, and oxygen saturations of 80% in room air. Her electrocardiogram, echocardiogram, and cardiac magnetic resonance were diagnostic of arrhythmogenic right ventricular dysplasia. There was no documented ventricular arrhythmia or syncopal episodes and Holter recordings were repeatedly normal. Cardiac hemodynamics showed right to left shunt through atrial septal defect, low pulmonary blood flow, normal atrial pressures, and minimally elevated right ventricular end-diastolic pressures. Since her presenting symptoms and cyanosis were attributed to reduced pulmonary blood flow, she underwent off-pump cavopulmonary anastomosis between right superior vena cava and right pulmonary artery. As we intended to avoid the adverse effect of extracorporeal circulation on the myocardial function and pulmonary vasculature, we did not attempt to reduce the size of the atrial septal defect. Her postoperative period was uneventful; oxygen saturation improved to 89% with significant improvement in effort tolerance. At 18-month follow-up, there were no ventricular arrhythmias on surveillance. The clinical presentation of this disease may vary from serious arrhythmias warranting defibrillators and electrical ablations at one end to right ventricular pump failure warranting cardiomyoplasty or right ventricular exclusion procedures at the other end. However, when the presentation was unusual with severe cyanosis through a stretched foramen ovale leading to reduced pulmonary blood flows, Glenn shunt served as a good palliation and should be considered as one of the options in such patients.

  14. Altered expression of genes regulating skeletal muscle mass in the portacaval anastomosis rat. (United States)

    Dasarathy, Srinivasan; Muc, Sean; Hisamuddin, Kola; Edmison, John M; Dodig, Milan; McCullough, Arthur J; Kalhan, Satish C


    We examined the temporal relationship between portacaval anastomosis (PCA), weight gain, changes in skeletal muscle mass and molecular markers of protein synthesis, protein breakdown, and satellite cell proliferation and differentiation. Male Sprague-Dawley rats with end to side PCA (n=24) were compared with sham-operated pair-fed rats (n=24). Whole body weight, lean body mass, and forelimb grip strength were determined at weekly intervals. The skeletal muscle expression of the ubiquitin proteasome system, myostatin, its receptor (the activin 2B receptor) and its signal, cyclin-dependent kinase inhibitor (CDKI) p21, insulin-like growth factor (IGF)-I and its receptor (IGF-I receptor-alpha), and markers of satellite cell proliferation and differentiation were quantified. PCA rats did not gain body weight and had lower lean body mass, forelimb grip strength, and gastrocnemius muscle weight. The skeletal muscle expression of the mRNA of ubiquitin proteasome components was higher in PCA rats in the first 2 wk followed by a lower expression in the subsequent 2 wk (Pmuscle protein synthesis, impaired satellite cell function, and lower skeletal muscle mass.

  15. EMG feedback and recovery of facial and speech gestures following neural anastomosis. (United States)

    Daniel, B; Guitar, B


    A case report is presented of an attempt to increase muscle activity during nonspeech and speech activities through surface electromyographic feedback. The subject, a 25-year-old male, had a surgical anastomosis of the seventh cranial to the twelfth cranial nerve five years prior to the initiation of this therapy. The right side of the face was immobile. Frequency analogs of muscle action potentials from the right lower lip during pressing, retraction, eversion, and speech were presented to the subject. His task was to increase the frequency of the tone thereby increasing muscle activity. The subject made substantial improvement in the gestures listed above. Electrodes also were placed in various infraorbital positions for an upper lip lifting task. This gesture was unimproved. Pre- and posttherapy independence of facial gestures from conscious tongue contraction was found. Possible explanations were proposed for (1) increases of muscle activity in the lower lip, (2) lack of change of MAPs in the upper lip, (3) independence of the facial muscle activity from conscious tongue contraction, and (4) effectiveness of this feedback training.

  16. Role of the trigeminal nerve in regrowth of hypoglossal motoneurons after hypoglossal-facial anastomosis. (United States)

    Mameli, Ombretta; Pellitteri, Rosalia; Russo, Antonella; Stanzani, Stefania; Caria, Marcello Alessandro; De Riu, Pier Luigi


    Conclusion. Functional recovery of facial muscles following hypoglossal-facial anastomosis (HFA) may be dependent not only on sensory information, relayed via the trigeminal nuclei to the hypoglossal nucleus, but also on extratrigeminal fibers, originating from the hypoglossal nucleus that travel in the infraorbital nerve (ION). This fact helps to explain the ability of hypoglossal neurons, after HFA, to induce contractions of muscles originally innervated from other nervous structures. Objective. The aim of the study was to better understand the role of the trigeminal nerve in reinnervation of facial muscles by hypoglossal motoneurons following HFA. Materials and methods. Central afferences of the ION were analyzed in rats by labeling the exposed nerve with horseradish peroxidase (HRP), whereas central organization of the efferent projections to the vibrissal area was analyzed by labeling the whisker pad muscles of the rat with a 5% solution of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil) in N,N-dimethylformamide. Results. The results show that extratrigeminal fibers, originating in the hypoglossal nucleus, travel along the ION. Retrograde tracing applied to ION or injected into the whisker pad showed labeled neurons in the Pr5 nucleus and all Sp5 trigeminal subnuclei. Small labeled neurons (10-15 microm diameter; 10-12 neurons per section), were also found in the hypoglossal nucleus.

  17. Primary Anastomosis versus Ostomy after Colon Resection during Debulking of Ovarian Carcinomatosis: A NSQIP Analysis. (United States)

    Fleetwood, Vidya A; Kubasiak, John C; Janssen, Imke; Myers, Jonathan A; Millikan, Keith W; Deziel, Daniel J; Luu, Minh B


    Ovarian carcinomatosis poses a dilemma for the surgeon. When resecting colon for tumor invasion, one must decide between diversion and primary anastomosis (PA). We examined the National Surgical Quality Improvement Program to determine whether PA associated with more complications than ostomy. The National Surgical Quality Improvement Program dataset was queried for patients with ovarian carcinomatosis between 2007 and 2012. Current Procedural Terminology codes were used to further identify patients undergoing colectomy with PA or ostomy. Logistic regression was used to evaluate 30-day morbidity and mortality. The 1013 ovarian carcinomatosis patients who underwent elective colon surgery were divided into primary repair (n = 453, 43.5%) or ostomy (n = 586, 56.5%) groups. Preoperative demographics were similar; however, ostomy patients had more severe preoperative laboratory derangements. The 30-day mortality and postoperative transfusion requirements were higher in the ostomy group. On multivariate analysis controlling for confounders, the differences were no longer significant. In conclusion, 30-day mortality and postoperative complications were increased in the ostomy group. Given the laboratory derangements in this group, this may reflect tendency to allocate ostomies to more ill patients. Primary repair in a selected population does not worsen outcomes. Prospective evaluation would help determine the impact of PA in the ovarian carcinomatosis population.

  18. Does bilioenteric anastomosis impair results of liver resection in primary intrahepatic lithiasis? (United States)

    Herman, Paulo; Perini, Marcos V; Pugliese, Vincenzo; Pereira, Julio Cesar; Machado, Marcel Autran C; Saad, William A; D'Albuquerque, Luiz A C; Cecconello, Ivan


    To evaluate the long-term results of liver resection for the treatment of primary intrahepatic lithiasis. Prognostic factors, especially the impact of bilioenteric anastomosis on recurrence of symptoms were assessed. Forty one patients with intrahepatic stones and parenchyma fibrosis/atrophy and/or biliary stenosis were submitted to liver resection. Resection was associated with a Roux-en-Y hepaticojejunostomy in all patients with bilateral stones and in those with unilateral disease and dilation of the extrahepatic biliary duct (> 2 cm). Late results and risk factors for recurrence of symptoms or stones were evaluated. There was no operative mortality. After a mean follow-up of 50.3 mo, good late results were observed in 82.9% of patients; all patients submitted to liver resection alone and 58.8% of those submitted to liver resection and hepaticojejunostomy were free of symptoms (P = 0.0006). Patients with unilateral and bilateral disease showed good late results in 94.1% and 28.6%, respectively (P < 0.001). Recurrence of symptoms in patients with hepaticojejunostomy showed that this may not be the ideal solution. Further studies are needed to establish the best treatment for patients with bilateral stones or unilateral disease and a dilated extrahepatic duct.

  19. Use of Indocyanine Green-SPY Angiography for Tracking Lymphatic Recovery After Lymphaticovenous Anastomosis. (United States)

    Shih, Hubert B; Shakir, Afaaf; Nguyen, Dung H


    Lymphaticovenous anastomosis (LVA) is a surgical treatment option for patients with early stage lymphedema. To date, no ideal imaging modality exists for tracking patency of the LVA postoperatively. We hypothesize that laser angiography utilizing indocyanine green (ICG) via the SPY system (Lifecell Corp.) would be a useful methodology for assessing the patency of the LVA and lymphatic recovery postoperatively. A prospective trial was performed on patients with stage II lymphedema who underwent LVA from 2013 to 2014 by a single surgeon. All candidates underwent preoperative and postoperative lymphatic mapping using ICG-SPY angiography. Postoperative analyses were performed at 1 month and at 9 months after surgery and assessed for patency at the site of the LVAs and for changes in lymphatic pattern. Five patients underwent LVA, 3 for upper extremity and 2 for lower extremity stage II lymphedema. The number of LVAs per extremity was 1 to 3 (total, 11). One month postoperative ICG-SPY angiography demonstrated flow through 9 of 11 anastomoses. Evaluation at 9 months postoperative showed improvement in lymphatic drainage. Indocyanine green-SPY angiography may be used to objectively evaluate the surgical outcome of LVA.

  20. fMRI after Phalloplasty with Nerve Anastomosis in a Trans-Man Patient (United States)

    Carlsson, Åsa; Jönsson, Emma H.; Jönsson, Lars; Thorarinsson, Andri; Lidén, Mattias; Selvaggi, Gennaro


    Summary: We report on a case of a trans-man patient, who underwent penile reconstruction with the use of a radial forearm flap, urethroplasty, vaginectomy and scrotoplasty, insertion of testicle implants, and penile erection implants, similar to previously described methods. One of the requirements for an ideal phalloplasty is the preservation of erogenous sensitivity, which is often demanded by the patients for fulfilling their sexual well-being. For the first time known to us, we use a functional magnetic resonance imaging following radial forearm flap phalloplasty with nerve anastomosis to assess the cortical activation after clitoral stimulation. The patient was poked with a plastic pen on the neophallus and the groin. Regular block design with T1 and BOLD-T2* images were used. The results contradict the classic Penfield and Rasmussen homunculus, that is, the activations in the primary somatosensory cortex (S1) were bilateral with a left-sided dominance in the lateral parts of the medial postcentral gyrus (same region as the groin), and no activations were observed in the mesial parts of the postcentral gyrus. We also reported bilateral activations with a left-sided dominance in the secondary somatosensory cortex (S2) and near Broca’s area at the sylvian fissure just posterior to ramus ascendens. Our findings are similar to previous studies reporting on imaging related to genital sensitivity. PMID:28740768

  1. An end-to-end anastomosis model of guinea pig bile duct: A 6-mo observation (United States)

    Zhang, Xiao-Qing; Tian, Yuan-Hu; Xu, Zhi; Wang, Li-Xin; Hou, Chun-Sheng; Ling, Xiao-Feng; Zhou, Xiao-Si


    AIM: To establish the end-to-end anastomosis (EEA) model of guinea pig bile duct and evaluate the healing process of bile duct. METHODS: Thirty-two male guinea pigs were randomly divided into control group, 2-, 3-, and 6-mo groups after establishment of EEA model. Histological, immunohistochemical and serologic tests as well as measurement of bile contents were performed. The bile duct diameter and the diameter ratio (DR) were measured to assess the formation of relative stricture. RESULTS: Acute and chronic inflammatory reactions occurred throughout the healing process of bile duct. Serology test and bile content measurement showed no formation of persistent stricture in 6-mo group. The DR revealed a transient formation of relative stricture in 2-mo group in comparation to control group (2.94 ± 0.17 vs 1.89 ± 0.27, P = 0.004). However, this relative stricture was released in 6-mo group (2.14 ± 0.18, P = 0.440). CONCLUSION: A simple and reliable EEA model of guinea pig bile duct can be established with a good reproducibility and a satisfactory survival rate. PMID:21390151

  2. MAPS Image Compression. (United States)


    SUMMARY MICRO-ADAPTIVE PICTURE SEQUENCING (MAPS) is a digital image data compression technique which originated at Control Data Corporation and underwent...w w Figure 1-3. Test Imagery Set 6 L.( The MAPS process is clearly sensitive to contrast but not to the Mean gray scale in the image . Thus, all images ...BUFFERED WORD TRANSFER RATES image processing Typical computa- tional functions which can be solved e DUAL 16-BIT INTERNAL DATA BUS SYSTEM with this

  3. Differential Privacy with Compression


    Zhou, Shuheng; Ligett, Katrina; Wasserman, Larry


    This work studies formal utility and privacy guarantees for a simple multiplicative database transformation, where the data are compressed by a random linear or affine transformation, reducing the number of data records substantially, while preserving the number of original input variables. We provide an analysis framework inspired by a recent concept known as differential privacy (Dwork 06). Our goal is to show that, despite the general difficulty of achieving the differential privacy guaran...

  4. Compressibility of solids (United States)

    Vinet, P.; Ferrante, J.; Rose, J. H.; Smith, J. R.


    A universal form is proposed for the equation of state (EOS) of solids. Good agreement is found for a variety of test data. The form of the EOS is used to suggest a method of data analysis, which is applied to materials of geophysical interest. The isothermal bulk modulus is discussed as a function of the volume and of the pressure. The isothermal compression curves for materials of geophysical interest are examined.

  5. Leak Rate Performance of Silicone Elastomer O-Rings Contaminated with JSC-1A Lunar Regolith Simulant (United States)

    Oravec, Heather Ann; Daniels, Christopher C.


    Contamination of spacecraft components with planetary and foreign object debris is a growing concern. Face seals separating the spacecraft cabin from the debris filled environment are particularly susceptible; if the seal becomes contaminated there is potential for decreased performance, mission failure, or catastrophe. In this study, silicone elastomer O-rings were contaminated with JSC- 1A lunar regolith and their leak rate performance was evaluated. The leak rate values of contaminated O-rings at four levels of seal compression were compared to those of as-received, uncontaminated, O-rings. The results showed a drastic increase in leak rate after contamination. JSC-1A contaminated O-rings lead to immeasurably high leak rate values for all levels of compression except complete closure. Additionally, a mechanical method of simulant removal was examined. In general, this method returned the leak rate to as-received values.

  6. Viscoelastic properties of elastomeric materials for O-ring applications (United States)

    Bower, Mark V.


    Redesign of the Space Shuttle Solid Rocket Booster necessitated re-evaluation of the material used in the field joint O-ring seals. This research project was established to determine the viscoelastic characteristics of five candidate materials. The five materials are: two fluorocarbon compounds, two nitrile compounds, and a silicon compound. The materials were tested in a uniaxial compression test to determine the characteristic relaxation functions. These tests were performed at five different temperatures. A master material curve was developed for each material from the experimental data. The results of this study are compared to tensile relaxation tests. Application of these results to the design analysis is discussed in detail.

  7. [Video-assisted thoracoscopic esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in thoracic cavity: analysis of 60 cases]. (United States)

    Sun, Xiang-xiang; Xu, Mei-qing; Guo, Ming-fa; Liu, Chang-qing; Xu, Shi-bin; Mei, Xin-yu; Tian, Jie-yong; Zhang, Zheng-hua; Wei, Da-zhong


    To investigate the feasibility and safety of video-assisted thoracoscopic esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity. The clinical data of 120 patients who underwent esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity from March to December 2011 was analyzed retrospectively. In the video-assisted thoracoscopic surgery group, there were 60 patients [41 male and 19 female patients with aver age of (62 ± 7) years old] who underwent video-assisted thoracoscopic esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity. In the routine thoracotomy group, there were 60 patients [39 male and 21 female patients with aver age of (62 ± 9) years old] who underwent routine thoracotomy esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity. Operation time, intra-operative blood loss, postoperative total thoracic drainage in 3 days, total number of harvested lymph nodes, hospitalization, cost of hospitalization and complications were compared between the two groups. The operations were carried out successfully in two groups. There was no perioperative death in all patients. There was no statistical difference in intra-operative blood loss, postoperative total thoracic drainage and cost of hospitalization between the two groups. Operation time of rideo-assisted thoracoscopic surgery group was significantly longer than that of thoracotomy group ((188 ± 38) minutes vs. (138 ± 50) minutes, t = 6.171, P = 0.000), but postoperative hospitalization was significantly lower ((14 ± 3) d vs. (18 ± 6) d, t = -4.093, P = 0.000) and total number of harvested lymph nodes was lower (17 ± 9 vs. 21 ± 11, t = -2.058, P = 0.042). There was significantly statistical difference in total postoperative main complication (25.0% vs. 48.3%, χ(2) = 7.033, P = 0.008). And postoperative incisional infection of VATE

  8. Measurement of Dead Space Fraction Upon ICU Admission Predicts Length of Stay and Clinical Outcomes Following Bidirectional Cavopulmonary Anastomosis. (United States)

    Cigarroa, Claire L; van den Bosch, Sarah J; Tang, Xiaoqi; Gauvreau, Kimberlee; Baird, Christopher W; DiNardo, James A; Kheir, John Nagi


    Increased alveolar dead space fraction has been associated with prolonged mechanical ventilation and increased mortality in pediatric patients with respiratory failure. The association of alveolar dead space fraction with clinical outcomes in patients undergoing bidirectional cavopulmonary anastomosis for single ventricle congenital heart disease has not been reported. We describe an association of alveolar dead space fraction with postoperative outcomes in patients undergoing bidirectional cavopulmonary anastomosis. In a retrospective case-control study, we examined for associations between alveolar dead space fraction ([PaCO2 - end-tidal CO2]/PaCO2), arterial oxyhemoglobin saturation, and transpulmonary gradient upon postoperative ICU admission with a composite primary outcome (requirement for surgical or catheter-based intervention, death, or transplant prior to hospital discharge, defining cases) and several secondary endpoints in infants following bidirectional cavopulmonary anastomosis. Cardiac ICU in a tertiary care pediatric hospital. Patients undergoing bidirectional cavopulmonary anastomosis at our institution between 2011 and 2016. None. Of 191 patients undergoing bidirectional cavopulmonary anastomosis, 28 patients were cases and 163 were controls. Alveolar dead space fraction was significantly higher in the case (0.26 ± 0.09) versus control group (0.17 ± 0.09; p space fraction at admission was less than 0.12 in 0% of cases and was greater than 0.28 in 35% of cases. Admission arterial oxyhemoglobin saturation was significantly lower in the case (77% ± 12%) versus control group (83% ± 9%; p space fraction (AUC, 0.74), and arterial oxyhemoglobin saturation (AUC, 0.65) were combined in a summarial model (AUC, 0.83). For a given arterial oxyhemoglobin saturation, the odds of becoming a case increased on average by 181% for every 0.1 unit increase in alveolar dead space fraction. Admission alveolar dead space fraction and arterial oxyhemoglobin

  9. Flow and wall shear stress in end-to-side and side-to-side anastomosis of venous coronary artery bypass grafts

    Directory of Open Access Journals (Sweden)

    Poulikakos Dimos


    Full Text Available Abstract Purpose Coronary artery bypass graft (CABG surgery represents the standard treatment of advanced coronary artery disease. Two major types of anastomosis exist to connect the graft to the coronary artery, i.e., by using an end-to-side or a side-to-side anastomosis. There is still controversy because of the differences in the patency rates of the two types of anastomosis. The purpose of this paper is to non-invasively quantify hemodynamic parameters, such as mass flow and wall shear stress (WSS, in end-to-side and side-to-side anastomoses of patients with CABG using computational fluid dynamics (CFD. Methods One patient with saphenous CABG and end-to-side anastomosis and one patient with saphenous CABG and side-to-side anastomosis underwent 16-detector row computed tomography (CT. Geometric models of coronary arteries and bypasses were reconstructed for CFD analysis. Blood flow was considered pulsatile, laminar, incompressible and Newtonian. Peri-anastomotic mass flow and WSS were quantified and flow patterns visualized. Results CFD analysis based on in-vivo CT coronary angiography data was feasible in both patients. For both types of CABG, flow patterns were characterized by a retrograde flow into the native coronary artery. WSS variations were found in both anastomoses types, with highest WSS values at the heel and lowest WSS values at the floor of the end-to-side anastomosis. In contrast, the highest WSS values of the side-to-side anastomosis configuration were found in stenotic vessel segments and not in the close vicinity of the anastomosis. Flow stagnation zones were found in end-to-side but not in side-to-side anastomosis, the latter also demonstrating a smoother stream division throughout the cardiac cycle. Conclusion CFD analysis of venous CABG based on in-vivo CT datasets in patients was feasible producing qualitative and quantitative information on mass flow and WSS. Differences were found between the two types of anastomosis

  10. Autumn study on storage rings

    CERN Multimedia


    The first two weeks of October have seen storage ring people from accelerator Laboratories throughout the world at CERN to study the fundamental problems of very high energy protonproton colliding beam machines.

  11. Burnside Rings of Fusion Systems

    DEFF Research Database (Denmark)

    Reeh, Sune Precht

    In this thesis we study the interactions between saturated fusion systems and group actions of the underlying p-groups. For a saturated fusion system F on a finite p-group S we construct the Burnside ring of F in terms of the finite S-sets whose actions respect the structure of the fusion system...... of the characteristic idempotent of F { the unique idempotent in the p-local double Burnside ring of S satisfying properties of Linckelmann and Webb. We describe this idempotent both in terms of fixed points and as a linear combination of transitive bisets. Additionally, using fixed points we determine the map...... of Burnside rings given by multiplication with the characteristic idempotent, and we show that this map is the transfer map previously constructed. Applying these results, we show that for every saturated fusion system the ring generated by all (non-idempotent) characteristic elements in the p-local double...

  12. Compression Amplification in Hearing Aids. (United States)

    Hickson, L M


    In this tutorial, the characteristics of compression amplification in analog hearing aids and the experimental results obtained with single- and multichannel compression amplification systems are reviewed. Single-channel compression systems are classified into four broad groups on the basis of their static and dynamic characteristics: compression limiters, syllabic compressors, automatic volume control (AVC) systems, and "others," those with adaptive recovery time (aRT) and dual frontend automatic gain control (AGC) (Moore, 1990; Moore & Glasberg, 1988). Multichannel compression devices have, to date, used a variety of different types of compression, with syllabic compression in each frequency channel being the most popular. Experimental evidence suggests that compression limiting is generally superior to peak clipping as a means of controlling output, except for some individuals with severe to profound hearing loss. There is some evidence that syllabic compression and AVC systems enhance speech perception in quiet compared to conventional linear amplification; however, this improvement is not consistently maintained in the presence of background noise. The majority of recent research has focused on multichannel compression, and favorable results have been obtained with some systems. Research findings about the efficacy of using compression amplification for people with hearing loss have been extremely variable, and possible reasons for this are discussed.

  13. $(n,m)$-SG rings


    Bennis, Driss


    This paper is a continuation of the paper Int. Electron. J. Algebra 6 (2009), 219-227. Namely, we introduce and study a doubly filtered set of classes of rings of finite Gorenstein global dimension, which are called $(n,m)$-SG for integers $n\\geq 1$ and $m\\geq 0$. Examples of $(n,m)$-SG rings, for $n=1$ and 2 and every $m\\geq 0$, are given.

  14. Black Saturn with dipole ring


    Yazadjiev, Stoytcho


    We present a new stationary, asymptotically flat solution of 5D Einstein-Maxwell gravity describing a Saturn-like black object: a rotating black hole surrounded by a rotating dipole black ring. The solution is generated by combining the vacuum black Saturn solution and the vacuum black ring solution with appropriately chosen parameters. Some basic properties of the solution are analyzed and the basic quantities are calculated.

  15. Commuting Π-regular rings

    Directory of Open Access Journals (Sweden)

    Shervin Sahebi


    Full Text Available ‎$R$ is called commuting regular ring (resp‎. ‎semigroupif‎ for each $x,y\\in R$ there exists $a\\in R$‎ such that$xy=yxayx$‎. ‎In this paper‎, ‎we introduce the concept of‎‎commuting $\\pi$-regular rings (resp‎. ‎semigroups and‎‎study various properties of them.

  16. Synlig læring

    DEFF Research Database (Denmark)

    Brandsen, Mads


    Introduktionen af John Hatties synlig læring i den danske skoleverden møder stadig meget kritik. Mange lærere og pædagoger oplever synlig læring som en tornado, der vil opsuge og ødelægge deres særlige danske udgave af den kontinentale dannelsestænkning, didaktik og pædagogik. Spørgsmålet er om...

  17. Black rings in six dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: [Institut fuer Physik, Universitaet Oldenburg, D-26111 Oldenburg (Germany); Kunz, Jutta; Radu, Eugen [Institut fuer Physik, Universitaet Oldenburg, D-26111 Oldenburg (Germany)


    We propose a general framework for the numerical study of balanced black rings for any spacetime dimensions d Greater-Than-Or-Slanted-Equal-To 5. Numerical solutions are constructed in a systematic way for d=6, by solving the Einstein field equations with suitable boundary conditions. These black rings have a regular event horizon with S{sup 1} Multiplication-Sign S{sup 3} topology, and they approach the Minkowski background asymptotically. We analyze their global and horizon properties.

  18. Optofluidic ring resonator dye lasers (United States)

    Sun, Yuze; Suter, Jonathan D.; Fan, Xudong


    We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall thickness of a few micrometers. The capillary circular cross-section forms the ring resonator and supports the whispering gallery modes (WGMs) that interact evanescently with the gain medium in the core. The laser cavity structure is versatile to adapt to the gain medium of any refractive index. Owing to the high Q-factor (>109), the lasing threshold of 25 nJ/mm2 is achieved. Besides directly pump the dye molecules, lasing through fluorescence resonance energy transfer (FRET) between the donor and acceptor dye molecules is also studied in COFRR laser. The energy transfer process can be further controlled by designed DNA scaffold labeled with donor/acceptor molecules. The ICOFRR dye laser is based on a cylindrical ring resonator fused onto the inner surface of a thick walled glass capillary. The structure has robust mechanical strength to sustain rapid gain medium circulation. The CpOFRR utilizes a cylindrical ring resonator fused on the inner surface of the COFRR capillary. Since the capillary wall is thin, the individual WGMs of the cylindrical ring resonator and the COFRR couples strongly and forms Vernier effect, which provides a way to generate a single mode dye laser.

  19. ring og forandring

    DEFF Research Database (Denmark)

    I de sidste ti år har læring været på dagsordenen som aldrig før. Inden for uddannelsesverdenen og den pædagogiske debat har man kunnet se et markant skift, hvor læringsbegrebet er blevet tematiseret langt stærkere på bekostning af undervisningsbegrebet. Samtidig er læring blevet sat på dagsordenen...

  20. Biomechanics of Corneal Ring Implants


    Daxer, Albert


    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant de...

  1. Electrothermal Ring Burn - Case Report

    Directory of Open Access Journals (Sweden)

    Yakup Çil


    Full Text Available Low-voltage fountainheads such as car, tractor or motorcycle batteries are predisposed to produce large currents. Any metal object that comes into contact with these batteries may result in short-circuit. This may result in rapid and excessive heating of metal object and an electrothermal burn. Herein we presented a motorcycle driver who was 28-year-old man with electrothermal ring burn which was caused by metal chain that was used as a ring.

  2. Gastrojejunal anastomosis stricture after laparoscopic gastric bypass: Our experience with 62 patients Estenosis de la anastomosis gastroyeyunal en el bypass gástrico laparoscópico: Nuestra experiencia con 62 pacientes

    Directory of Open Access Journals (Sweden)

    A. Campillo-Soto


    Full Text Available Objective: gastrojejunal stricture (GYS, not only is a common complication after laparoscopic gastric bypass (LGBP, but its frequency is about 15% according to bibliography. Our aim is to present our experience after 62 LGBP. Patients and method: from January 2004 to September-2006, we performed 62 consecutive laparoscopic gastric bypass (Wittgrove's technique. The gastrojejunal anastomosis is performed with auto suture material type CEAA No 21 termino-lateral (ILS, Ethicon. In 4 cases (6.45% was converted to laparotomy, perform the anastomosis in the same way. Monitoring has a range of 3-35 months, conducted in 61 patients because one patient died of pulmonary thromboembolism in the immediate postoperative period after reoperation, after two weeks of gastric bypass, by necrosis of a small fragment of the remnant gastric. In all patients with persistent feeding intolerance were performed barium transit and/or gastroscopy. When gastrojejunal stricture showed proceeded to endoscopic pneumatic dilation (recommending dilate the anastomosis to a maximum 1.5 cm. Results: five cases (8.1% developed a gastrojejunal stricture, in 4 of these cases the initial diagnosis was made by barium transit and in 1 case by endoscopy. Two patients had a history of digestive bleeding that required endoscopic sclerosis of the bleeding lesion (circumferentially sclerosis within 48 hours of surgery and sclerosis of bleeding points. All cases were resolved by endoscopic dilatation. At follow-up has not been detected re-stricture. Conclusion: Clinically, gastrojejunal stricture results in a progressive oral intolerance, revealing stenosis between 1 and 3 months postoperatively. The situations of sclerosis of the bleeding lesions favor, especially in cases of extensive sclerosis. In cases of suspected barium transit offers us a high diagnostic yield. Endoscopic dilatation resolved, so far, all cases.Objetivo: la estenosis de la anastomosis gastroyeyunal representa una

  3. Testing compression strength of wood logs by drilling resistance (United States)

    Kalny, Gerda; Rados, Kristijan; Rauch, Hans Peter


    Soil bioengineering is a construction technique using biological components for hydraulic and civil engineering solutions, based on the application of living plants and other auxiliary materials including among others log wood. Considering the reliability of the construction it is important to know about the durability and the degradation process of the wooden logs to estimate and retain the integral performance of a soil bioengineering system. An important performance indicator is the compression strength, but this parameter is not easy to examine by non-destructive methods. The Rinntech Resistograph is an instrument to measure the drilling resistance by a 3 mm wide needle in a wooden log. It is a quasi-non-destructive method as the remaining hole has no weakening effects to the wood. This is an easy procedure but result in values, hard to interpret. To assign drilling resistance values to specific compression strengths, wooden specimens were tested in an experiment and analysed with the Resistograph. Afterwards compression tests were done at the same specimens. This should allow an easier interpretation of drilling resistance curves in future. For detailed analyses specimens were investigated by means of branch inclusions, cracks and distances between annual rings. Wood specimens are tested perpendicular to the grain. First results show a correlation between drilling resistance and compression strength by using the mean drilling resistance, average width of the annual rings and the mean range of the minima and maxima values as factors for the drilling resistance. The extended limit of proportionality, the offset yield strength and the maximum strength were taken as parameters for compression strength. Further investigations at a second point in time strengthen these results.

  4. Lubrication of Piston Rings in Large 2–and 4–stroke Diesel Engines

    DEFF Research Database (Denmark)

    Felter, Christian Lotz

    Piston rings are vital components of any internal combustion engine, and their performance affect important properties such as frictional losses, oil consumption, and wear of parts. This thesis deals with the lubrication of piston rings from a theoretical point of view. Predictions are made using...... numerical models implemented as computer programs. The classical Reynolds equation can be used to calculate the pressure distribution in thin films of fluid. In relation to piston ring lubrication it is, however, less straight forward to apply the Reynolds equation since the inlet (and outlet) point...... is fulfilled in a quasi-static sense a concrete example is analyzed using the Reynolds equation. Next a free surface 2D code based on the compressible Navier–Stokes equations is developed. The main idea is to model also the oil film outside the piston ring. Through time integration the movement of the inlet...

  5. Compressive Phase Contrast Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao


    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

  6. Portacaval shunt established in six dogs using magnetic compression technique.

    Directory of Open Access Journals (Sweden)

    Xiaopeng Yan

    Full Text Available BACKGROUND AND AIMS: Installing the transjugular intrahepatic portosystemic shunt for portal hypertension is relatively safe, but complications are still high. To explore a new method of portacaval shunt, the magnetic compression technique was introduced into the shunting procedure. METHODS: A portal-inferior vena cava shunt was performed on 6 male mongrel dogs by two hemocompatible Nd-Fe-B permanent magnets, parent and daughter. The parent magnet was applied to the inferior vena cava guided by a catheter through the femoral vein. The daughter magnet was moved to the anastomosis position on the portal vein with a balloon catheter through the splenic vein. After the daughter magnet reached the target position, the two magnets acted to compress the vessel wall and hold it in place. Five to 7 days later, under X-ray guidance, the magnets were detached from the vessel wall with a rosch-uchida transjugular liver access set. One month later, histological analysis and portal venography were performed. RESULTS: 5-7 days after the first surgery, a mild intimal hyperplasia in the portal vein and the inferior vena cava, and continuity of the vascular adventitia from the portal vein to the inferior vena cava as observed. During the second surgery, the contrast media could be observed flowing from the portal vein into the inferior vena cava. Portal venography revealed that the portosystemic shunt was still present one month after the second surgery. CONCLUSIONS: Magnamosis via a device of novel design was successfully used to establish a portacaval shunt in dogs.

  7. Mammographic compression in Asian women (United States)

    Lau, Susie; Abdul Aziz, Yang Faridah; Ng, Kwan Hoong


    Objectives To investigate: (1) the variability of mammographic compression parameters amongst Asian women; and (2) the effects of reducing compression force on image quality and mean glandular dose (MGD) in Asian women based on phantom study. Methods We retrospectively collected 15818 raw digital mammograms from 3772 Asian women aged 35–80 years who underwent screening or diagnostic mammography between Jan 2012 and Dec 2014 at our center. The mammograms were processed using a volumetric breast density (VBD) measurement software (Volpara) to assess compression force, compression pressure, compressed breast thickness (CBT), breast volume, VBD and MGD against breast contact area. The effects of reducing compression force on image quality and MGD were also evaluated based on measurement obtained from 105 Asian women, as well as using the RMI156 Mammographic Accreditation Phantom and polymethyl methacrylate (PMMA) slabs. Results Compression force, compression pressure, CBT, breast volume, VBD and MGD correlated significantly with breast contact area (pimage quality (p>0.05). Conclusions Force-standardized protocol led to widely variable compression parameters in Asian women. Based on phantom study, it is feasible to reduce compression force up to 32.5% with minimal effects on image quality and MGD. PMID:28419125

  8. International magnetic pulse compression (United States)

    Kirbie, H. C.; Newton, M. A.; Siemens, P. D.


    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12-14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card - its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  9. Compressive Transient Imaging

    KAUST Repository

    Sun, Qilin


    High resolution transient/3D imaging technology is of high interest in both scientific research and commercial application. Nowadays, all of the transient imaging methods suffer from low resolution or time consuming mechanical scanning. We proposed a new method based on TCSPC and Compressive Sensing to achieve a high resolution transient imaging with a several seconds capturing process. Picosecond laser sends a serious of equal interval pulse while synchronized SPAD camera\\'s detecting gate window has a precise phase delay at each cycle. After capturing enough points, we are able to make up a whole signal. By inserting a DMD device into the system, we are able to modulate all the frames of data using binary random patterns to reconstruct a super resolution transient/3D image later. Because the low fill factor of SPAD sensor will make a compressive sensing scenario ill-conditioned, We designed and fabricated a diffractive microlens array. We proposed a new CS reconstruction algorithm which is able to denoise at the same time for the measurements suffering from Poisson noise. Instead of a single SPAD senor, we chose a SPAD array because it can drastically reduce the requirement for the number of measurements and its reconstruction time. Further more, it not easy to reconstruct a high resolution image with only one single sensor while for an array, it just needs to reconstruct small patches and a few measurements. In this thesis, we evaluated the reconstruction methods using both clean measurements and the version corrupted by Poisson noise. The results show how the integration over the layers influence the image quality and our algorithm works well while the measurements suffer from non-trival Poisson noise. It\\'s a breakthrough in the areas of both transient imaging and compressive sensing.

  10. Fast Compressive Tracking. (United States)

    Zhang, Kaihua; Zhang, Lei; Yang, Ming-Hsuan


    It is a challenging task to develop effective and efficient appearance models for robust object tracking due to factors such as pose variation, illumination change, occlusion, and motion blur. Existing online tracking algorithms often update models with samples from observations in recent frames. Despite much success has been demonstrated, numerous issues remain to be addressed. First, while these adaptive appearance models are data-dependent, there does not exist sufficient amount of data for online algorithms to learn at the outset. Second, online tracking algorithms often encounter the drift problems. As a result of self-taught learning, misaligned samples are likely to be added and degrade the appearance models. In this paper, we propose a simple yet effective and efficient tracking algorithm with an appearance model based on features extracted from a multiscale image feature space with data-independent basis. The proposed appearance model employs non-adaptive random projections that preserve the structure of the image feature space of objects. A very sparse measurement matrix is constructed to efficiently extract the features for the appearance model. We compress sample images of the foreground target and the background using the same sparse measurement matrix. The tracking task is formulated as a binary classification via a naive Bayes classifier with online update in the compressed domain. A coarse-to-fine search strategy is adopted to further reduce the computational complexity in the detection procedure. The proposed compressive tracking algorithm runs in real-time and performs favorably against state-of-the-art methods on challenging sequences in terms of efficiency, accuracy and robustness.

  11. Reinforcement core facilitates O-ring installation (United States)


    Reinforcement core holds O-ring in place within a structure while adjacent parts are being assembled. The core in the O-ring adds circumferential rigidity to the O-ring material. This inner core does not appreciably affect the sectional elasticity or gland-sealing characteristics of the O-ring.

  12. Metal Hydride Compression

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bowman, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Barton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anovitz, Lawrence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jensen, Craig [Hawaii Hydrogen Carriers LLC, Honolulu, HI (United States)


    Conventional hydrogen compressors often contribute over half of the cost of hydrogen stations, have poor reliability, and have insufficient flow rates for a mature FCEV market. Fatigue associated with their moving parts including cracking of diaphragms and failure of seal leads to failure in conventional compressors, which is exacerbated by the repeated starts and stops expected at fueling stations. Furthermore, the conventional lubrication of these compressors with oil is generally unacceptable at fueling stations due to potential fuel contamination. Metal hydride (MH) technology offers a very good alternative to both conventional (mechanical) and newly developed (electrochemical, ionic liquid pistons) methods of hydrogen compression. Advantages of MH compression include simplicity in design and operation, absence of moving parts, compactness, safety and reliability, and the possibility to utilize waste industrial heat to power the compressor. Beyond conventional H2 supplies of pipelines or tanker trucks, another attractive scenario is the on-site generating, pressuring and delivering pure H2 at pressure (≥ 875 bar) for refueling vehicles at electrolysis, wind, or solar generating production facilities in distributed locations that are too remote or widely distributed for cost effective bulk transport. MH hydrogen compression utilizes a reversible heat-driven interaction of a hydride-forming metal alloy with hydrogen gas to form the MH phase and is a promising process for hydrogen energy applications [1,2]. To deliver hydrogen continuously, each stage of the compressor must consist of multiple MH beds with synchronized hydrogenation & dehydrogenation cycles. Multistage pressurization allows achievement of greater compression ratios using reduced temperature swings compared to single stage compressors. The objectives of this project are to investigate and demonstrate on a laboratory scale a two-stage MH hydrogen (H2) gas compressor with a

  13. Analysis by compression

    DEFF Research Database (Denmark)

    Meredith, David

    MEL is a geometric music encoding language designed to allow for musical objects to be encoded parsimoniously as sets of points in pitch-time space, generated by performing geometric transformations on component patterns. MEL has been implemented in Java and coupled with the SIATEC pattern discov...... discovery algorithm to allow for compact encodings to be generated automatically from in extenso note lists. The MEL-SIATEC system is founded on the belief that music analysis and music perception can be modelled as the compression of in extenso descriptions of musical objects....

  14. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben


    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...

  15. Hemodynamics and arteriovenous malformations in cavopulmonary anastomosis: the case for residual antegrade pulsatile flow. (United States)

    Henaine, Roland; Vergnat, Mathieu; Mercier, Olaf; Serraf, Alain; De Montpreville, Vincent; Ninet, Jean; Bacha, Emile A


    Continuous flow in Fontan circulation results in impairment of pulmonary artery endothelial function, increased pulmonary vascular resistance, and, potentially, late failure of Fontan circulation. Bidirectional cavopulmonary shunt is the interim procedure in palliation of patients with single-ventricle physiology, but pulmonary arteriovenous malformations occur in many patients. In a porcine chronic model of cavopulmonary shunt, we studied pulmonary hemodynamics, pulmonary arteriovenous malformation occurrence, and gas exchange capabilities. We hypothesized that residual antegrade pulsatile pulmonary flow may attenuate the deleterious effects of nonpulsatile Fontan-type circulation. Thirty pigs underwent a sham procedure (n = 10, group I), a cavopulmonary shunt with right pulmonary artery ligation (n = 10, group II, nonpulsatile), or a cavopulmonary shunt with proximal right pulmonary artery partial ligation (n = 10, group III, micropulsatile). Three months later, in vivo hemodynamics, blood gas exchange, pulmonary arteriovenous malformation occurrence, and lung histology were assessed. At 3 months, group II right lungs demonstrated significantly increased pulmonary artery pressure, pulmonary vascular resistance, and evidence of pulmonary arteriovenous malformations compared with groups I and III (all P < .001). Group III lungs also showed increased pulmonary artery pressure and pulmonary vascular resistance compared with the sham group, but significantly less than group II. Group III right lungs had the best gas exchange performance, with less histologic changes compared with group II. We developed a viable chronic large animal model of bidirectional cavopulmonary anastomosis. Residual antegrade pulsatile flow in the setting of a cavopulmonary shunt prevents pulmonary arteriovenous malformation formation and attenuates, but does not suppress, the development of pulmonary hypertension. From a clinical standpoint, these data would support keeping a small

  16. Detection of transplant renal artery stenosis: determining normal velocities at the renal artery anastomosis. (United States)

    Robinson, Kristin A; Kriegshauser, J Scott; Dahiya, Nirvikar; Young, Scott W; Czaplicki, Christopher D; Patel, Maitray D


    Renal artery anastomosis peak systolic velocity (RAA PSV) exceeding 250 cm/s and a ratio of the renal artery to the adjacent external iliac artery (RAA:EIA) exceeding 1.8 historically suggest significant transplant renal artery stenosis (TRAS). However, the range of RAA PSV in transplants without TRAS has not been established. A retrospective review of renal transplants at a single institution over 5 years was performed identifying patients without graft dysfunction, failure, or refractory hypertension. RAA PSV obtained during interval postoperative sonograms was recorded. Of 1141 patients, 844 met the inclusion criteria. Mean RAA PSV for 377 patients evaluated within 2 days of transplant measured 195 cm/s; RAA PSV exceeded 250 cm/s in 97 patients (26%). Mean RAA PSV for 820 patients evaluated 1-month post-transplant measured 206 cm/s; RAA PSV exceeded 250 cm/s in 224 patients (27%). Mean RAA PSV for 785 patients evaluated 4-month post-transplant measured 203 cm/s; RAA PSV exceeded 250 cm/s in 201 patients (26%). Mean RAA PSV for 766 patients evaluated 1-year post-transplant measured 189 cm/s; RAA PSV exceeded 250 cm/s in 141 patients (18%). At each of the given time points, 24%-34% of normal patients had RAA-to-EIA ratios greater than 1.8. Approximately, 26% of patients without TRAS have RAA PSV > 250 cm/s in the first 9 months, and 18% do at 1 year. Similar findings also occurred with regards to the RAA-to-EIA ratio threshold of 1.8. In isolation, a PSV over 250 cm/s or 1.8 ratio threshold for suspicion of TRAS will lead to a large number of false-positive assessments.

  17. Outcome after restorative proctocolectomy and ileal pouch-anal anastomosis in children and adults. (United States)

    Diederen, K; Sahami, S S; Tabbers, M M; Benninga, M A; Kindermann, A; Tanis, P J; Oomen, M W; de Jong, J R; Bemelman, W A


    Studies comparing the outcome of ileal pouch-anal anastomosis (IPAA) in children and adults are scarce. This complicates decision-making in young patients. The aim of this study was to compare adverse events and pouch function between children and adults who underwent IPAA. This cross-sectional cohort study included all consecutive children (aged less than 18 years) and adults with a diagnosis of inflammatory bowel disease or familial adenomatous polyposis who underwent IPAA in a tertiary referral centre between 2000 and 2015. Adverse events were assessed by chart review, and pouch function by interview using a pouch function score (PFS). In total, 445 patients underwent IPAA: 41 children (median age 15 years) and 404 adults (median age 39 years), with a median follow-up of 22 (i.q.r. 8-68) months. Being overweight (P = 0·001), previous abdominal surgery (P = 0·018), open procedures (P children than adult patients. The occurrence of anastomotic leakage, surgical fistulas, chronic pouchitis and Crohn's of the pouch was not associated with paediatric age at surgery, nor was pouch failure. The development of anastomotic strictures was associated with having IPAA surgery during childhood (odds ratio 4·22, 95 per cent c.i. 1·13 to 15·77; P = 0·032). Pouch function at last follow-up was similar in the children and adult groups (median PFS 5·0 versus 6·0 respectively; P = 0·194). Long-term pouch failure rates and pouch function were similar in children and adults. There is no need for a more cautious attitude to use of IPAA in children based on concerns about poor outcome. © 2017 BJS Society Ltd Published by John Wiley & Sons Ltd.

  18. In Vitro Fertilization Is Successful in Women With Ulcerative Colitis and Ileal Pouch Anal Anastomosis. (United States)

    Pabby, Vikas; Oza, Sveta Shah; Dodge, Laura E; Hacker, Michele R; Moragianni, Vasiliki A; Correia, Katherine; Missmer, Stacey A; Fox, Janis H; Ibrahim, Yetunde; Penzias, Alan; Burakoff, Robert; Cheifetz, Adam; Friedman, Sonia


    Women with ulcerative colitis (UC), who require ileal pouch anal anastomosis (IPAA), have up to a threefold increased incidence of infertility. To better counsel patients who require colectomy, we examined the success rates of in vitro fertilization (IVF) among women who have undergone IPAA. This was a retrospective cohort study conducted at the Brigham and Women's Hospital and Beth Israel Deaconess Medical Center. Female patients with UC were identified via ICD-9 codes and cross-referenced with those presenting for IVF from 1998 through 2011. UC patients with IPAA were compared with the following two unexposed groups that underwent IVF: (1) patients with UC, who had not undergone IPAA, and (2) patients without inflammatory bowel disease (IBD). The primary outcome was the cumulative live birth rate. Secondary outcomes included number of oocytes retrieved, proportion of patients who underwent embryo transfer, pregnancy rate, and live birth rate at first cycle. There were 22 patients with UC and IPAA, 49 patients with UC and without IPAA, and 470 patients without IBD. The cumulative live birth rate after six cycles in the UC and IPAA groups was 64% (95% confidence interval (CI): 44-83%). This rate did not differ from the cumulative live birth rate in the UC without IPAA group (71%, 95% CI: 59-83%; P=0.63) or the group without IBD (53%, 95% CI: 48-57%; P=0.57). This study demonstrates that in our cohort, women who undergo IPAA achieve live births following IVF at comparable rates to women with UC without IPAA and to women without IBD.

  19. Impact of ileal pouch-anal anastomosis on female fertility: meta-analysis and systematic review. (United States)

    Rajaratnam, Siraj G; Eglinton, Timothy W; Hider, Phil; Fearnhead, Nicola S


    The aim of this review is to determine the effect of ileal pouch-anal anastomosis (IPAA) on female fertility in ulcerative colitis (UC) and familial adenomatous polyposis (FAP), the mechanisms of this effect, strategies for prevention and management of infertility post-IPAA. This paper is a systematic literature review of all articles investigating IPAA and fertility from 1966 onwards that were found searching the Medline and Embase databases. Meta-analysis was performed on relevant studies. Seventeen relevant studies were identified. Six studies were excluded (duplicate data, one; predominantly not IPAA patients, one; no control group, four). The control groups of the remaining 11 studies were too varied for comparison, and so the meta-analysis was limited to six studies that provided data on infertility both pre- and post-IPAA. Five of these involved predominantly UC patients and one FAP. Average infertility rates were 20% pre-IPAA and 63% post-IPAA. The relative risk of infertility after IPAA is 3.91 ([2.06, 7.44] 95% CI). The possibility of publication bias suggests that the risk may be lower. Any increased risk is probably due to tubal dysfunction secondary to adhesions. Various methods have been proposed to reduce pelvic adhesions, but there is no evidence they have any effect in preventing infertility. Infertility treatment post-IPAA is associated with good success rates. Infertility is increased after IPAA in female patients in both UC and FAP. Both these disease processes affect patients during their reproductive years. This evidence emphasizes the need for careful consideration of fertility in the choice and timing of surgery.

  20. Cropping Systems and Cultural Practices Determine the Rhizoctonia Anastomosis Groups Associated with Brassica spp. in Vietnam (United States)

    Soltaninejad, Saman; Höfte, Monica


    Ninety seven Rhizoctonia isolates were collected from different Brassica species with typical Rhizoctonia symptoms in different provinces of Vietnam. The isolates were identified using staining of nuclei and sequencing of the rDNA-ITS barcoding gene. The majority of the isolates were multinucleate R. solani and four isolates were binucleate Rhizoctonia belonging to anastomosis groups (AGs) AG-A and a new subgroup of A-F that we introduce here as AG-Fc on the basis of differences in rDNA-ITS sequence. The most prevalent multinucleate AG was AG 1-IA (45.4% of isolates), followed by AG 1-ID (17.5%), AG 1-IB (13.4%), AG 4-HGI (12.4%), AG 2-2 (5.2%), AG 7 (1.0%) and an unknown AG related to AG 1-IA and AG 1-IE that we introduce here as AG 1-IG (1.0%) on the basis of differences in rDNA-ITS sequence. AG 1-IA and AG 1-ID have not been reported before on Brassica spp. Pathogenicity tests revealed that isolates from all AGs, except AG-A, induced symptoms on detached leaves of several cabbage species. In in vitro tests on white cabbage and Chinese cabbage, both hosts were severely infected by AG 1-IB, AG 2-2, AG 4-HGI, AG 1-IG and AG-Fc isolates, while under greenhouse conditions, only AG 4-HGI, AG 2-2 and AG-Fc isolates could cause severe disease symptoms. The occurrence of the different AGs seems to be correlated with the cropping systems and cultural practices in different sampling areas suggesting that agricultural practices determine the AGs associated with Brassica plants in Vietnam. PMID:25372406

  1. Sexuality and fertility outcomes after hand sewn versus stapled ileal pouch anal anastomosis for ulcerative colitis. (United States)

    Harnoy, Yann; Desfourneaux, Véronique; Bouguen, Guillaume; Rayar, Michel; Meunier, Bernard; Siproudhis, Laurent; Boudjema, Karim; Sulpice, Laurent


    Ileal pouch anal anastomosis (IPAA) may alter sexuality and fertility in women. The laparoscopic approach seems to reduce infertility rates in women after IPAA. However, the impact of hand sewn versus stapled IPAA on sexuality and fertility has never been assessed in patients with ulcerative colitis (UC). The objective of this study was to analyze the impact of the IPAA technique on sexuality and fertility in UC. All UC patients who underwent an IPAA between May 1996 and April 2011 were included. The patients answered mailed questionnaires including sexuality validated questionnaires and fertility questionnaires. The risk factors of sexual dysfunction were explored. A total of 135 patients were included. Eighty-eight patients (65%) answered the questionnaires. Their mean age and follow-up were 37.2 ± 13.4 y and 109.7 ± 57.5 mo. The rates of female and male sexual dysfunction were 50% and 29%, respectively. Intestinal transit disorders were identified as risk factors in both men and women and anastomotic stricture in women sexual dysfunction, in univariate analyses. The IPAA technique did not impact sexual function in women but there was a trend for less erectile dysfunction after hand sewn IPAA (16.7% versus 44.4%). The fertility rate was 47% in women and 75% in men, with a trend for a better fertility in women after hand sewn IPAA (P = 0.07). In this preliminary study, the hand sewn or stapled IPAA technique did not impact the sexuality or fertility outcomes of UC patients, but there was a trend for better female fertility and male erectile function after hand sewn IPAA. Intestinal transit disorders contributed to male and female sexual dysfunction after IPAA. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Manipulation of vortex rings for flow control

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Kuniaki; Hiramoto, Riho [Mechanical Systems Engineering, Hokkaido Institute of Technology, Maeda 7-15-4-1, Teine-ku, Sapporo 006-855 (Japan)], E-mail:


    This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

  3. Concluding Remarks on the Planetary Rings Conference


    Stone, E. C.


    In the past five years ring systems have been discovered around Uranus and Jupiter and a wealth of new data acquired about Saturn's rings. This vigorous observational program has been accompanied by renewed theoretical interest in ring systems. Although all of these topics have been addressed in papers at this first conference on planetary rings, these concluding remarks are focused on some of the key aspects of Saturn's rings about which more needs to be understood throu...

  4. Dream of Isochronous Ring Again

    CERN Document Server

    Hama, H


    More than 20 years ago, D.A.G. Deacon proposed an isochronous storage ring for FEL to avoid bunch heating and decreasing instantaneous gain [1]. Some of low momentum compaction (alpha) operations have been carried out, and recently coherent infrared radiation are observed on a 3rd generation light source. Because the 3rd generation rings are optimized to obtain very low emittance beam, the dispersion function in the arc sections are much reduced by introducing large bending radius, so that those are very big machines. Meanwhile N.A. Vinokurov et al. recently proposed a ring type SASE FEL based on a complete isochronous bending transport [2]. At least, experimental and theoretical study of the isochronous ring so far suggests nonlinear effects resulted from higher order dispersion and chromaticity declines the "complete" isochronous system. On the other hand, in a wavelength region of THz, tolerance of the path length along a turn of the ring seems to be within our reach. A concept to preserve of a form factor...

  5. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons


    Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

  6. Compressive Sensing DNA Microarrays

    Directory of Open Access Journals (Sweden)

    Sheikh Mona A


    Full Text Available Compressive sensing microarrays (CSMs are DNA-based sensors that operate using group testing and compressive sensing (CS principles. In contrast to conventional DNA microarrays, in which each genetic sensor is designed to respond to a single target, in a CSM, each sensor responds to a set of targets. We study the problem of designing CSMs that simultaneously account for both the constraints from CS theory and the biochemistry of probe-target DNA hybridization. An appropriate cross-hybridization model is proposed for CSMs, and several methods are developed for probe design and CS signal recovery based on the new model. Lab experiments suggest that in order to achieve accurate hybridization profiling, consensus probe sequences are required to have sequence homology of at least 80% with all targets to be detected. Furthermore, out-of-equilibrium datasets are usually as accurate as those obtained from equilibrium conditions. Consequently, one can use CSMs in applications in which only short hybridization times are allowed.

  7. FY2017 status report: Model 9975 O-ring fixture long-term leak performance

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    A series of experiments to monitor the aging performance of Viton® GLT and GLT-S O-rings used in the Model 9975 shipping package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups with GLT O-rings were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, a smaller test matrix with fourteen additional tests was initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. Leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The 300 °F GLT O-ring fixtures failed after 2.8 to 5.7 years at temperature. The remaining GLT O-ring fixtures aging at 300 ºF were retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 9 to 10.5 years, or in GLT O-ring fixtures aging at 270 ºF for 5.7 years. These aging temperatures bound O-ring temperatures anticipated during normal storage in K-Area Complex (KAC). Leak test failures have been experienced in all of the GLT-S O-ring fixtures aging at 300 ºF and above. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 and 250 ºF for 6.9 to 7.5 years. Data from the O-ring fixtures are generally consistent with results from compression stress relaxation testing, and provide confidence in the predictive models based on those results

  8. Introduction to compressible fluid flow

    CERN Document Server

    Oosthuizen, Patrick H


    IntroductionThe Equations of Steady One-Dimensional Compressible FlowSome Fundamental Aspects of Compressible FlowOne-Dimensional Isentropic FlowNormal Shock WavesOblique Shock WavesExpansion Waves - Prandtl-Meyer FlowVariable Area FlowsAdiabatic Flow with FrictionFlow with Heat TransferLinearized Analysis of Two-Dimensional Compressible FlowsHypersonic and High-Temperature FlowsHigh-Temperature Gas EffectsLow-Density FlowsBibliographyAppendices

  9. Shock compression of precompressed deuterium (United States)

    Armstrong, Michael; Crowhurst, Jonathan; Goncharov, Alexander; Zaug, Joseph; Bastea, Sorin; Militzer, Burkhard


    Here we report quasi-isentropic dynamic compression and thermodynamic characterization of solid, precompressed deuterium over an ultra fast time scale (< 100 ps) and a microscopic length scale (< 1 ìm). We further report a fast transition in dynamically compressed solid deuterium that is consistent with the ramp to shock transition, with a time scale of less than 10 ps. These results suggest that high density dynamic compression of hydrogen may be possible on microscopic length scales.

  10. Spectroscopic insight for tablet compression. (United States)

    Lakio, S; Ylinärä, H; Antikainen, O; Räikkönen, H; Yliruusi, J


    Tablet compression process has been studied over the years from various perspectives. However what exactly happens to material during compression is still unknown. In this study a novel compression die which enables real-time spectroscopic measurements during the compression of material is represented. Both near infrared and Raman spectroscope probes can be attached to the die. In this study the usage of the die is demonstrated by using Raman spectroscopy. Eicosane, d-glucose anhydrate, α-lactose monohydrate and xylitol were used in the study because their compression behavior and bonding properties during compression were assumed to be different. The intensity of the Raman signal changed during compression with all of the materials. However, the intensity changes were different within the materials. The biggest differences were within the xylitol spectra. It was noticed that some peaks disappeared with higher compression pressures indicating that the pressure affected variously on different bonds in xylitol structure. These reversible changes were supposed to relate the changes in conformation and crystal structure. As a conclusion, the die was found to be a significant addition for studying compression process in real-time. It can help to reveal Process induced transformations (PITs) occurring during powder compaction. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Lossless Compression of Broadcast Video

    DEFF Research Database (Denmark)

    Martins, Bo; Eriksen, N.; Faber, E.


    We investigate several techniques for lossless and near-lossless compression of broadcast video.The emphasis is placed on the emerging international standard for compression of continous-tone still images, JPEG-LS, due to its excellent compression performance and moderatecomplexity. Except for one...... artificial sequence containing uncompressible data all the 4:2:2, 8-bit test video material easily compresses losslessly to a rate below 125 Mbit/s. At this rate, video plus overhead can be contained in a single telecom 4th order PDH channel or a single STM-1 channel. Difficult 4:2:2, 10-bit test material...

  12. Crohn's disease recurrence in patients with ileocolic anastomosis: Value of computed tomography enterography with water enema

    Energy Technology Data Exchange (ETDEWEB)

    Paparo, Francesco [Department of Radiology, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa (Italy); Revelli, Matteo; Puppo, Cristina [School of Radiology, University of Genoa, Via Leon Battista Alberti 4, 16132 Genoa (Italy); Bacigalupo, Lorenzo; Garello, Isabella [Department of Radiology, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa (Italy); Garlaschi, Alessandro [School of Radiology, University of Genoa, Via Leon Battista Alberti 4, 16132 Genoa (Italy); Biscaldi, Ennio [Department of Radiology, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa (Italy); Rollandi, Ludovica [School of Medicine, University of Genoa, Via Leon Battista Alberti 4, 16132 Genoa (Italy); Binda, Gian Andrea [Division of General Surgery, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa (Italy); Rollandi, Gian Andrea, E-mail: [Department of Radiology, E.O. Ospedali Galliera, Mura della Cappuccine 14, 16128 Genoa (Italy)


    Objectives: the main objective of the present work was to determine the diagnostic value of CT-enterography with water enema (CTe-WE) in the assessment of the ileocolic anastomosis in patients with Crohn's disease (CD). The prevalence of synchronous inflammatory lesions (SILs) involving gastrointestinal segments distinct from the anastomosis was also determined. Further, the association between the type of ileocolic anastomosis and the behavior (i.e. inflammatory, stricturing, penetrating) of CD recurrence was evaluated. Methods: 51 patients were retrospectively included (26 [51%] male and 25 [49%] female; mean age: 52.88 years ± 13.35). Ileocolic anastomoses were: 18 (35.3%) stapled side-to-side, 17 (33.3%) end-to-side, and 16 (31.4%) end-to-end. CTe-WEs were reviewed in consensus by two gastrointestinal radiologists. Endoscopy and medical records were used as reference standards. Results: CTe-WE yielded 95.35% sensitivity (CI 95%: 84.19–99.43%), 75.00% specificity (CI 95%: 34.91–96.81%), and 92.15% diagnostic accuracy (CI 95%: 81.31–98.02%). Anastomotic recurrence was found in 41/51 (80.4%) patients, including 30/41 (73.2%) cases of isolated anastomotic recurrence, and 11/41 (26.8%) cases of anastomotic recurrence with a SIL. A significant lower prevalence of stricturing recurrence was observed in patients with stapled side-to-side anastomoses (p = 0.033). Conclusions: CTe-WE provides a good distension of both sides of ileocolic anastomoses allowing the detection of SILs.

  13. Extending the reach of stapled anastomosis with a prepared OrVil™ device in laparoscopic oesophageal and gastric cancer surgery. (United States)

    Salih, Abdelmonim E A; Bass, Gary A; D'Cruz, Yvonne; Brennan, Robert P; Smolarek, Sebastian; Arumugasamy, Mayilone; Walsh, Thomas N


    The introduction of minimally invasive surgery and the use of laparoscopic techniques have significantly improved patient outcomes and have offered a new range of options for the restoration of intestinal continuity. Various reconstruction techniques have been described and various devices employed but none has been established as superior. This study evaluates our experience with, and modifications of, the orally inserted anvil (OrVil™). We conducted a prospective observational study on 72 consecutive patients who underwent OrVil™-assisted oesophago-gastric or oesophago-jejunal anastomosis between September 2010 and September 2013. We collected data including patient demographics, disease site, type of procedure, location of the anastomosis, involvement of resection margins and peri-operative complications. Seventy-two patients were included in the study. Patient ages ranged from 45 to 92 years (median ± SD = 69 ± 10 years). Total gastrectomy with Roux-en-Y anastomosis was the most-commonly performed procedure (n = 41; 57 %). R 0 resection was achieved in 67 patients (93 %). There were no Orvil™-related clinical leaks during the study period, and just two patients (2.8 %) demonstrated radiological evidence of leak, both of whom were managed conservatively. There were three in-hospital mortalities during the study period; these were unrelated to the anastomotic technique. Despite a steep learning curve, the OrVil™ device is safe and reliable. It also permits the creation of higher trans-hiatal anastomoses without resorting to thoracotomy in high-risk patients with cardia tumours. Certain shortcomings of the device, that had implications for patient safety, were identified and addressed by intra-operative modification during the study period. We commend the use of a prepared OrVil™ device, as a game changer, for upper gastrointestinal reconstruction.

  14. Primary anastomosis with a defunctioning stoma versus Hartmann's procedure for perforated diverticulitis--a comparison of stoma reversal rates. (United States)

    Alizai, P H; Schulze-Hagen, M; Klink, C D; Ulmer, F; Roeth, A A; Neumann, U P; Jansen, M; Rosch, R


    The ideal treatment of patients with perforated diverticulitis is still controversial. Hartmann's procedure has been the treatment of choice for decades, but primary anastomosis with a defunctioning stoma has become an accepted alternative. The aim of this study was to evaluate the stoma reversal rates after these two surgical strategies. A retrospective review of the data from patients with perforated sigmoid diverticulitis between 2002 and 2011 undergoing a Hartmann's procedure (HP) versus a primary anastomosis with a defunctioning stoma (PA) was performed. Additionally, patients were contacted by mail or telephone in March 2012 using a standardized questionnaire. A total of 98 patients were identified: 72 undergoing HP and 26 patients receiving PA. The median follow-up time was 63 months (range 4-118). Whilst 85 % of patients with PA have had their stoma reversed, only 58 % of patients with an HP had a stoma reversal (p = 0.046). The median period until stoma reversal was significantly longer for HP (19 weeks) than for PA (12 weeks; p = 0.03). The 30-day mortality for PA was 12 % as opposed to 25 % for HP (p = 0.167). According to the Clavien-Dindo classification, surgical complications occurred significantly less frequently in patients with PA (p = 0.014). The stoma reversal rates for PA are significantly higher than for HP. Thus, depending on the overall clinical situation, primary resection and anastomosis with a proximal defunctioning stoma might be the optimal procedure for selected patients with perforated diverticular disease.

  15. Mini-mastoidectomía para anastomosis hipogloso-facial con sección parcial del nervio hipogloso (United States)

    Campero, Álvaro; Ajler, Pablo; Socolovsky, Mariano; Martins, Carolina; Rhoton, Albert


    Introducción: La anastomosis hipogloso-facial es la técnica de elección para la reparación de la parálisis facial cuando no se dispone de un cabo proximal sano del nervio facial. La técnica de anastomosis mediante fresado mastoideo y sección parcial del hipogloso minimiza la atrofia lingual sin sacrificar resultados a nivel facial. Método: La porción mastoidea del nervio facial transcurre por la pared anterior de la AM, a un promedio de 18+/-3 mm de profundidad respecto de la pared lateral. Se debe reconocer la cresta supramastoidea, desde la cual se marca una línea vertical paralela al eje mayor de la AM, 1 cm por detrás de la pared posterior del CAE El fresado se comienza desde la línea medio mastoidea hasta la pared posterior del CAE. Una vez encontrado el nervio facial en el tercio medio del canal mastoideo, el mismo es seguido hacia proximal y distal. Resultados: El abordaje descripto permite acceder al nervio facial intratemporal en su porción mastoidea, y efectuar un fresado óseo sin poner en riesgo al nervio o a estructuras vasculares cercanas. Se trata de un procedimiento técnicamente más sencillo que los abordajes amplios habitualmente utilizados al hueso temporal; no obstante su uso debe ser restringido mayormente a la anastomosis hipogloso-facial. Conclusión: Esta es una técnica relativamente sencilla, que puede ser reproducida por cirujanos sin mayor experiencia en el tema, luego de su paso por el laboratorio de anatomía. PMID:23596555

  16. Effects of intraluminal infusion of short-chain fatty acids on the healing of colonic anastomosis in the rat. (United States)

    Rolandelli, R H; Koruda, M J; Settle, R G; Rombeau, J L


    The effects of an intracolonic infusion of short-chain fatty acids (SCFA) on the healing of colonic anastomosis in the rat were investigated. Thirty-three Sprague-Dawley rats underwent transection and anastomosis of the descending colon and transection and diversion of the ascending colon. The proximal limb of the ascending colon was exteriorized as an end colostomy, and the distal (defunctionalized) limb was cannulated for continuous infusion. Rats received either no infusion (N = 11) or an infusion of either electrolytes (N = 11) or SCFA (acetate, propionate, and butyrate; N = 11) into the defunctionalized colonic segment. On the sixth postoperative day bursting pressure (BP) and bowel wall tension (BWT) were determined. The occurrence of spontaneous anastomotic dehiscence was significantly less for the SCFA group (0/11) compared with the no infusion group (5/11, p less than 0.01). The anastomotic suture line burst in significantly fewer colons from the SCFA group (1/11) than either the electrolyte infusion (8/11, p less than 0.003) or the no infusion (6/6, p less than 0.001) groups. BP and BWT were significantly higher for the SCFA group (BP: 147 +/- 10 mm Hg; BWT: 59 +/- 1.0 dyne 10(3)/cm) than for either the electrolyte (BP: 99 +/- 30 mm Hg, p less than 0.002; BWT: 45 +/- 19, p less than 0.03) or no infusion (BP: 111 +/- 42, p less than 0.02; BWT 36 +/- 15, p less than 0.007) groups. The results of this study indicate that intracolonic infusion of SCFA resulted in significantly stronger colonic anastomosis in the rat.

  17. Traumatic colon injury in damage control laparotomy-A multicenter trial: Is it safe to do a delayed anastomosis? (United States)

    Tatebe, Leah Carey; Jennings, Andrew; Tatebe, Ken; Handy, Alexandra; Prajapati, Purvi; Smith, Michael; Do, Tai; Ogola, Gerald O; Gandhi, Rajesh R; Duane, Therese M; Luk, Stephen; Petrey, Laura Bruce


    Delayed colonic anastomosis after damage control laparotomy (DCL) is an alternative to colostomies during a single laparotomy (SL) in high-risk patients. However, literature suggests increased colonic leak rates up to 27% with DCL, and various reported risk factors. We evaluated our regional experience to determine if delayed colonic anastomosis was associated with worse outcomes. A multicenter retrospective cohort study was performed across three Level I trauma centers encompassing traumatic colon injuries from January 2006 through June 2014. Patients with rectal injuries or mortality within 24 hours were excluded. Patient and injury characteristics, complications, and interventions were compared between SL and DCL groups. Regional readmission data were utilized to capture complications within 6 months of index trauma. Of 267 patients, 69% had penetrating injuries, 21% underwent DCL, and the mortality rate was 4.9%. Overall, 176 received primary repair (26 in DCL), 90 had resection and anastomosis (28 in DCL), and 26 had a stoma created (10 end colostomies and 2 loop ileostomies in DCL). Thirty-five of 56 DCL patients had definitive colonic repair subsequent to their index operation. DCL patients were more likely to be hypotensive; require more resuscitation; and suffer acute kidney injury, pneumonia, adult respiratory distress syndrome, and death. Five enteric leaks (1.9%) and three enterocutaneous fistulas (ECF, 1.1%) were identified, proportionately distributed between DCL and SL (p = 1.00, p = 0.51). No difference was seen in intraperitoneal abscesses (p = 0.13) or surgical site infections (SSI, p = 0.70) between cohorts. Among SL patients, pancreas injuries portended an increased risk of intraperitoneal abscesses (p = 0.0002), as did liver injuries in DCL patients (p = 0.06). DCL was not associated with increased enteric leaks, ECF, SSI, or intraperitoneal abscesses despite nearly two-thirds having delayed repair. Despite this being a multicenter study, it is

  18. Ring vaccination and smallpox control. (United States)

    Kretzschmar, Mirjam; van den Hof, Susan; Wallinga, Jacco; van Wijngaarden, Jan


    We present a stochastic model for the spread of smallpox after a small number of index cases are introduced into a susceptible population. The model describes a branching process for the spread of the infection and the effects of intervention measures. We discuss scenarios in which ring vaccination of direct contacts of infected persons is sufficient to contain an epidemic. Ring vaccination can be successful if infectious cases are rapidly diagnosed. However, because of the inherent stochastic nature of epidemic outbreaks, both the size and duration of contained outbreaks are highly variable. Intervention requirements depend on the basic reproduction number (R0), for which different estimates exist. When faced with the decision of whether to rely on ring vaccination, the public health community should be aware that an epidemic might take time to subside even for an eventually successful intervention strategy.

  19. Anastomosis colorrectal facilitada mediante empleo de dispositivo de sellado tisular: estudio comparativo en animal de experimentación


    Sánchez de Pedro, Francisco


    En el ámbito de la cirugía son muchos los avances que se han venido produciendo en los últimos años en aspectos tales como materiales protésicos, dispositivos y materiales para hemostasia o procedimientos de abordaje menos invasivos. Con la irrupción en la práctica quirúrgica de vías de abordaje mínimamente invasivas, han surgido nuevas dificultades técnicas a la hora de realizar las diferentes maniobras quirúrgicas, entre ellas la creación de anastomosis, lo que demanda el desarrollo d...

  20. Tree rings and radiocarbon calibration

    Energy Technology Data Exchange (ETDEWEB)

    Barbetti, M. [University of Sydney, Sydney, NSW (Australia). NWG Macintosh Centre for Quaternary Dating


    Only a few kinds of trees in Australia and Southeast Asia are known to have growth rings that are both distinct and annual. Those that do are therefore extremely important to climatic and isotope studies. In western Tasmania, extensive work with Huon pine (Lagarostrobos franklinii) has shown that many living trees are more than 1,000 years old, and that their ring widths are sensitive to temperature, rainfall and cloud cover (Buckley et al. 1997). At the Stanley River there is a forest of living (and recently felled) trees which we have sampled and measured. There are also thousands of subfossil Huon pine logs, buried at depths less than 5 metres in an area of floodplain extending over a distance of more than a kilometre with a width of tens of metres. Some of these logs have been buried for 50,000 years or more, but most of them belong to the period between 15,000 years and the present. In previous expeditions in the 1980s and 1990s, we excavated and sampled about 350 logs (Barbetti et al. 1995; Nanson et al. 1995). By measuring the ring-width patterns, and matching them between logs and living trees, we have constructed a tree-ring dated chronology from 571 BC to AD 1992. We have also built a 4254-ring floating chronology (placed by radiocarbon at ca. 3580 to 7830 years ago), and an earlier 1268-ring chronology (ca. 7,580 to 8,850 years ago). There are many individuals, or pairs of logs which match and together span several centuries, at 9,000 years ago and beyond 15 refs., 1 tab., 1 fig.

  1. Nanoscale nonlinear PANDA ring resonator

    CERN Document Server

    Yupapin, Preecha


    Microring/nanoring resonator is an interesting device that has been widely studied and investigated by researchers from a variety of specializations. This book begins with the basic background of linear and nonlinear ring resonators. A novel design of nano device known as a PANDA ring resonator is proposed. The use of the device in the form of a PANDA in applications such as nanoelectronics, measurement, communication, sensors, optical and quantum computing, drug delivery, hybrid transistor and a new concept of electron-hole pair is discussed in detail.

  2. ring eller indlæring?

    DEFF Research Database (Denmark)

    Holsting, Vilhelm Stefan; Sjøstedt, Peter; Sørensen, Dorthe

    Dette working paper skal bidrage til den pædagogiske debat i forsvaret. Tekstens for mål er at støtte udviklingen af en voksenpædagogik i forsvaret, baseret på en konstruktivistisk opfattelse af læring, hvilket er i overensstemmelse med konklusionerne i rapporten fra Arbejdsgruppe vedrørende...

  3. Autologous nerve graft repair of different degrees of sciatic nerve defect: stress and displacement at the anastomosis in a three-dimensional fnite element simulation model

    Directory of Open Access Journals (Sweden)

    Cheng-dong Piao


    Full Text Available In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the magnitude of tensile forces at the anastomosis affects its response to physiological stress and the ultimate success of the treatment. One-dimensional stretching is commonly used to measure changes in tensile stress and strain however, the accuracy of this simple method is limited. Therefore, in the present study, we established three-dimensional finite element models of sciatic nerve defects repaired by autologous nerve grafts. Using PRO E 5.0 finite element simulation software, we calculated the maximum stress and displacement of an anastomosis under a 5 N load in 10-, 20-, 30-, 40-mm long autologous nerve grafts. We found that maximum displacement increased with graft length, consistent with specimen force. These findings indicate that three-dimensional finite element simulation is a feasible method for analyzing stress and displacement at the anastomosis after autologous nerve grafting.

  4. Axisymmetric contour dynamics for buoyant vortex rings (United States)

    Chang, Ching; Llewellyn Smith, Stefan


    Vortex rings are important in many fluid flows in engineering and environmental applications. A family of steady propagating vortex rings including thin-core rings and Hill's spherical vortex was obtained by Norbury (1973). However, the dynamics of vortex rings in the presence of buoyancy has not been investigated yet in detail. When the core of a ring is thin, we may formulate reduced equations using momentum balance for vortex filaments, but that is not the case for ``fat'' rings. In our study, we use contour dynamics to study the time evolution of axisymmetric vortex rings when the density of the fluid inside the ring differs from that of the ambient. Axisymmetry leads to an almost-conserved material variable when the Boussinesq approximation is made. A set of integro-differential equations is solved numerically for these buoyant vortex rings. The same physical settings are also used to run a DNS code and compare to the results from contour dynamics.

  5. Adaptively Compressed Exchange Operator

    CERN Document Server

    Lin, Lin


    The Fock exchange operator plays a central role in modern quantum chemistry. The large computational cost associated with the Fock exchange operator hinders Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals, even for systems consisting of hundreds of atoms. We develop the adaptively compressed exchange operator (ACE) formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. In an iterative framework for solving Hartree-Fock-like systems, the ACE formulation only requires moderate modification of the code, and can be potentially beneficial for all electronic structure software packages involving exchange calculations. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens...

  6. Waves and compressible flow

    CERN Document Server

    Ockendon, Hilary


    Now in its second edition, this book continues to give readers a broad mathematical basis for modelling and understanding the wide range of wave phenomena encountered in modern applications.  New and expanded material includes topics such as elastoplastic waves and waves in plasmas, as well as new exercises.  Comprehensive collections of models are used to illustrate the underpinning mathematical methodologies, which include the basic ideas of the relevant partial differential equations, characteristics, ray theory, asymptotic analysis, dispersion, shock waves, and weak solutions. Although the main focus is on compressible fluid flow, the authors show how intimately gasdynamic waves are related to wave phenomena in many other areas of physical science.   Special emphasis is placed on the development of physical intuition to supplement and reinforce analytical thinking. Each chapter includes a complete set of carefully prepared exercises, making this a suitable textbook for students in applied mathematics, ...

  7. Central cooling: compressive chillers

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.


    Representative cost and performance data are provided in a concise, useable form for three types of compressive liquid packaged chillers: reciprocating, centrifugal, and screw. The data are represented in graphical form as well as in empirical equations. Reciprocating chillers are available from 2.5 to 240 tons with full-load COPs ranging from 2.85 to 3.87. Centrifugal chillers are available from 80 to 2,000 tons with full load COPs ranging from 4.1 to 4.9. Field-assemblied centrifugal chillers have been installed with capacities up to 10,000 tons. Screw-type chillers are available from 100 to 750 tons with full load COPs ranging from 3.3 to 4.5.

  8. Transmission of compressed video (United States)

    Pasch, H. L.


    An overview of video coding is presented. The aim is not to give a technical summary of possible coding techniques, but to address subjects related to video compression in general and to the transmission of compressed video in more detail. Bit rate reduction is in general possible by removing redundant information; removing information the eye does not use anyway; and reducing the quality of the video. The codecs which are used for reducing the bit rate, can be divided into two groups: Constant Bit rate Codecs (CBC's), which keep the bit rate constant, but vary the video quality; and Variable Bit rate Codecs (VBC's), which keep the video quality constant by varying the bit rate. VBC's can be in general reach a higher video quality than CBC's using less bandwidth, but need a transmission system that allows the bandwidth of a connection to fluctuate in time. The current and the next generation of the PSTN does not allow this; ATM might. There are several factors which influence the quality of video: the bit error rate of the transmission channel, slip rate, packet loss rate/packet insertion rate, end-to-end delay, phase shift between voice and video, and bit rate. Based on the bit rate of the coded video, the following classification of coded video can be made: High Definition Television (HDTV); Broadcast Quality Television (BQTV); video conferencing; and video telephony. The properties of these classes are given. The video conferencing and video telephony equipment available now and in the next few years can be divided into three categories: conforming to 1984 CCITT standard for video conferencing; conforming to 1988 CCITT standard; and conforming to no standard.

  9. Contact mechanical analysis of O-ring stresses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kyu


    The purpose of this project is to develop the approximate solutions of contact traction and internal stress of an O-ring by using a two dimensional elasticity for enhancing the design and failure prediction technology. Investigated were the applicability of Lindley's formulae of contact force prediction and the Hertz theory. Three cases of O-ring installation were considered. The approximate solution of contact tractions and internal stresses of each case were derived. The key results are summarized as follows: 1. It is verified that Lindley's formulae predicts the relationship between the fractional compression and contact force. 2. In the case of Case I, II and III without internal pressure, it is found that a function form of the contact traction is the Hertzian. So it is possible to express the traction with a Hertzian form and correction factors. 3. The internal stresses are derived in the case of the Hertzian traction profile. The stresses at the center of O-ring show a satisfactory result when compared with the finite element result.

  10. The presentation and management of vascular rings: an otolaryngology perspective. (United States)

    Shah, Rahul K; Mora, Bassem N; Bacha, Emile; Sena, Laureen M; Buonomo, Carlo; Del Nido, Pedro; Rahbar, Reza


    To review the presentation and natural history of children with vascular rings and present management guidelines. Retrospective study of tertiary care pediatric medical center charts from 1991 to 2002. There were 37 males and 27 females with a diagnosis of vascular rings. At presentation, 91% of patients had airway symptoms and 47% had esophageal symptoms. Airway symptoms included stridor (63%), recurrent respiratory infections (47%), respiratory distress (19%), and cough (17%). The most common esophageal symptom was dysphagia (27%). Pre-operative studies included: echocardiography (96%), chest X-ray (93%), barium swallow (75%), magnetic resonance imaging (MRI) (60%), and computerized tomography (CT) scan of the chest (59%). Surgical management included open (n=25) and thoracoscopic (n=39) approach. Complications included recurrent laryngeal nerve injury in five patients (8%). Children with vascular rings present with respiratory and/or feeding difficulty. The evaluation should include chest X-ray, echocardiography, and barium swallow. Direct laryngoscopy and bronchoscopy are recommended to assess the degree of compression of the airway and/or esophagus, tracheomalacia, and vocal fold motion prior to intervention. Indication for surgical release is given when the diagnosis is made and can be assisted by advanced radiology studies. Surgical options include minimally invasive techniques involving either thoracoscopic or robotic-assisted repairs, as well as open procedures involving thoracotomy.

  11. Detection of biliary stenoses in patients after liver transplantation: is there a different diagnostic accuracy of MRCP depending on the type of biliary anastomosis? (United States)

    Kinner, Sonja; Dechêne, Alexander; Paul, Andreas; Umutlu, Lale; Ladd, Susanne C; de Dechêne, Evelin Maldonado; Zöpf, Thomas; Gerken, Guido; Lauenstein, Thomas C


    Two different forms of biliary anastomosis can be created in patients undergoing liver transplantation: (a) bilio-digestive anastomoses or (b) choledocho-choledochostomy. Aim of this study was to assess the accuracy of MR cholangiopancreatography (MRCP) for the depiction of biliary stenoses in liver transplant patients depending on the type of biliary anastomosis. 24 liver transplant patients with clinical suspicion of biliary stenosis were studied (each 12 with bilio-digestive anastomosis/choledocho-choledochostomy). MRCP was performed on a 1.5 T scanner (Magnetom Avanto, Siemens) including 2D single shot RARE, 2D T2w HASTE, TrueFISP and 3D high-resolution navigator corrected sequences. Presence of (a) anastomotic stenoses (AST) and (b) NAS (non-anastomotic strictures) were assessed. Percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangiopancreatography (ERCP) were performed within 48h after MRCP and served as the standard of reference. In patients with bilio-digestive anastomoses sensitivities of MRCP for the detection of AST and NAS amounted to 50% and 67%, respectively with specificity values of 83% and 50%. In patients with choledocho-chledochostomy sensitivities (AST: 100%, NAS: 100%) and specificities (AST: 100%, NAS: 88%) were significantly higher. Biliary strictures after liver transplantation can be accurately detected by MRCP in patients after choledocho-chledochostomy. However, the diagnostic value of MRCP is lower if liver transplantation was performed in combination with a bilio-digestive anastomosis. This may be due to the less exact depiction of the anastomosis in the bowel wall. Thus, it is crucial to know the type of biliary anastomosis before choosing a diagnostic procedure. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  12. Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia) heals ileoileal anastomosis in the rat. (United States)

    Vuksic, Tihomir; Zoricic, Ivan; Brcic, Luka; Sever, Marko; Klicek, Robert; Radic, Bozo; Cesarec, Vedran; Berkopic, Lidija; Keller, Neike; Blagaic, Alenka Boban; Kokic, Neven; Jelic, Ivan; Geber, Juraj; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag


    Gastric pentadecapeptide BPC 157 (BPC 157), which has been shown to be safe in clinical trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia), may be able to cure intestinal anastomosis dehiscence. This antiulcer peptide shows no toxicity, is limit test negative, and a lethal dose is not achieved. It is stable in human gastric juice. In comparison with other standard treatments it is more effective for ulcers and various wounds, and can be used without a carrier needed for other peptides, both locally and systemically (i.e., perorally, parenterally). We studied the effectiveness of BPC 157 for ileoileal anastomosis healing in rats. We assessed ileoileal anastomosis dehiscence macroscopically, histologically, and biomechanically (volume [ml] infused through a syringe-perfusion pump system (1 ml/10 s), and pressure [mmHg] to leak induction [catheter connected to a chamber and a monitor, at 10 cm proximal to anastomosis]), at 1, 2, 3, 4, 5, 6, 7, and 14 days. BPC 157 (10 microg, 10 ng, 10 pg/kg i.p. (or saline [5 ml/kg]) was first administered after surgery, while it was last given 24 h before either assessment or sacrifice. Throughout the experiment, both higher doses of BPC 157 were shown to improve all parameters of anastomotic wound healing. The formation of adhesions remained slight, the blood vessels were filled with blood, and a mild intestinal passage obstruction was only temporarily observed. Anastomosis without leakage induces markedly higher volume and pressure values, with a continuous increase toward healthy values. From day 1, edema was markedly attenuated and the number of granulocytes decreased, while from days 4 or 5 necrosis decreased and granulation tissue, reticulin, and collagen formation substantially increased, thus resulting in increased epithelization. This study showed BPC 157 to have a beneficial effect on ileoileal anastomosis healing in the rat.

  13. Detection of biliary stenoses in patients after liver transplantation: Is there a different diagnostic accuracy of MRCP depending on the type of biliary anastomosis?

    Energy Technology Data Exchange (ETDEWEB)

    Kinner, Sonja, E-mail: [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen (Germany); Dechene, Alexander [Department of Hepatology and Gastroenterology, University Hospital Essen (Germany); Paul, Andreas [Department of General-, Visceral- and Transplant Surgery, University Hospital Essen (Germany); Umutlu, Lale; Ladd, Susanne C. [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen (Germany); Dechene, Evelin Maldonado de; Zoepf, Thomas; Gerken, Guido [Department of Hepatology and Gastroenterology, University Hospital Essen (Germany); Lauenstein, Thomas C. [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen (Germany)


    Purpose: Two different forms of biliary anastomosis can be created in patients undergoing liver transplantation: (a) bilio-digestive anastomoses or (b) choledocho-choledochostomy. Aim of this study was to assess the accuracy of MR cholangiopancreatography (MRCP) for the depiction of biliary stenoses in liver transplant patients depending on the type of biliary anastomosis. Method and materials: 24 liver transplant patients with clinical suspicion of biliary stenosis were studied (each 12 with bilio-digestive anastomosis/choledocho-choledochostomy). MRCP was performed on a 1.5T scanner (Magnetom Avanto, Siemens) including 2D single shot RARE, 2D T2w HASTE, TrueFISP and 3D high-resolution navigator corrected sequences. Presence of (a) anastomotic stenoses (AST) and (b) NAS (non-anastomotic strictures) were assessed. Percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangiopancreatography (ERCP) were performed within 48 h after MRCP and served as the standard of reference. Results: In patients with bilio-digestive anastomoses sensitivities of MRCP for the detection of AST and NAS amounted to 50% and 67%, respectively with specificity values of 83% and 50%. In patients with choledocho-chledochostomy sensitivities (AST: 100%, NAS: 100%) and specificities (AST: 100%, NAS: 88%) were significantly higher. Conclusion: Biliary strictures after liver transplantation can be accurately detected by MRCP in patients after choledocho-chledochostomy. However, the diagnostic value of MRCP is lower if liver transplantation was performed in combination with a bilio-digestive anastomosis. This may be due to the less exact depiction of the anastomosis in the bowel wall. Thus, it is crucial to know the type of biliary anastomosis before choosing a diagnostic procedure.

  14. Tight bounds for top tree compression

    DEFF Research Database (Denmark)

    Bille, Philip; Fernstrøm, Finn; Gørtz, Inge Li


    We consider compressing labeled, ordered and rooted trees using DAG compression and top tree compression. We show that there exists a family of trees such that the size of the DAG compression is always a logarithmic factor smaller than the size of the top tree compression (even for an alphabet...

  15. ANASTOMOSIS ENTRE LA RAMA PROFUNDA DEL NERVIO CUBITAL Y EL NERVIO MEDIANO EN LA MANO. Anastomosis between the deep branch of the ulnar nerve and the median nerve in the hand

    Directory of Open Access Journals (Sweden)

    Luis E Criado del Río


    Full Text Available Introducción: La anastomosis de Riche-Cannieu (ARC es una variación anatómica formada entre la rama tenar del nervio mediano (NM y la rama profunda del nervio cubital (NC. Debido a la importancia clínica y electromiográfica su descripción anatómica es de gran interés, ya que debido a esta variación anatómica existen distintas formas de inervación motora a nivel de la mano. Materiales y Métodos: Se realizaron disecciones cadavéricas en 38 manos (19 cadáveres de ambos sexos formolizados en solución al 5 %, de entre 50 y 70 años de edad. Se utilizó instrumental y técnicas convencionales de disección. Resultados: En la rama profunda del NC no se evidenciaron variaciones y finalizaba su recorrido en el músculo aductor del pulgar. En el 86,84%  de los casos emerge una rama que se anastomosa con el NM de diferentes formas. Esta rama anastomótica, en el 50% de las manos, era una arcada nerviosa de considerable calibre entre el NC y NM, que daba ramas motoras a los músculos de la eminencia tenar. Discusión: El conocimiento de esta anastomosis es muy importante ya que, en casos de lesión del nervio mediano o cubital, puede causar confusión clínica, quirúrgica y en los hallazgos electromiográficos. Debido a su alta frecuencia fue considerada un rasgo anatómico normal. Introduction: The Riche-Cannieu anastomosis (RCA is an anatomic variation formed between the thenar branch of the median nerve and the deep branch of the ulnar nerve. Its anatomical description is of great interest because of its clinical and electromyographic relevance. Due to the RCA, there are various types of hand motor innervation. Materials and Methods: Thirty eight hands from 19 corpses (formolized in a 5% solution whose ages ranged from 50 to 70 years old were dissected. Conventional instruments and techn-iques were used. Results: The pathway of the deep branch of the ulnar nerve did not show variations and ended at the adductor pollicis muscle. In 86

  16. Clostridium difficile infection after restorative proctocolectomy and ileal pouch anal anastomosis for ulcerative colitis. (United States)

    Martinez Ugarte, M L; Lightner, A L; Colibaseanu, D; Khanna, S; Pardi, D S; Dozois, E J; Mathis, K L


    Clostridium difficile infection (CDI) of the ileal pouch following restorative proctocolectomy (RPC) is becoming increasingly recognized. We aimed to understand better (i) the associated risk factors, (ii) treatment practices and (iii) the pouch diversion and failure rate in patients who developed CDI of the pouch after RPC for ulcerative colitis (UC). Patients who tested positive for C. difficile of the pouch between 2007 and 2010 were included in the analysis. Data collected included patient demographics, time from RPC to documented CDI, the treatment of CDI and rate of excision of the pouch. Of 2785 patients recorded in the hospital CDI database, 15 had had an RPC with ileal pouch anal anastomosis. The median age was 44 years and the median interval from RPC to first documented episode of CDI was 3 years. Thirteen (81%) patients had had multiple episodes of pouchitis before and after CDI infection, and all were symptomatic at the time of testing for CDI. Within 30 days of the diagnosis of CDI, six (40%) patients were taking immunosuppressive medication, seven (47%) were taking a proton pump inhibitor and 12 (80%) had received antibiotics. Five patients required hospitalization for CDI and four had severe infections characterized by a serum creatinine more than 1.5 times baseline (n = 3) and a white cell count above 15 000 (n = 1). Six patients who underwent endoscopy had severe inflammation of the pouch including the presence of a pseudomembrane in one case. Ten patients were treated with metronidazole alone and five with vancomycin. Two patients had recurrent CDI of the pouch during a median follow-up period of 2.9 years and one had CDI refractory to medical management. This patient required diversion of the pouch with an ileostomy for refractory CDI but no patient required excision of the pouch. All 15 patients developing CDI of the pouch were successfully treated with antibiotics and only one required surgery in the form of an ileostomy. Colorectal

  17. Revisional single-anastomosis gastric bypass for a failed restrictive procedure: 5-year results. (United States)

    Bruzzi, Matthieu; Voron, Thibault; Zinzindohoue, Franck; Berger, Anne; Douard, Richard; Chevallier, Jean-Marc


    Long-term outcomes of revisional laparoscopic single anastomosis-gastric bypass for a failed restrictive procedure (rSAGB) have not been analyzed. To assess 5-year outcomes of rSAGB compared with 5-year outcomes of primary SAGB (pSAGB). University public hospital, France. One hundred twenty-six patients who underwent SAGB between October 2006 and October 2008 were included in this retrospective study. rSAGB was defined as SAGB performed after failure of a first restrictive procedure. Five-year outcomes of each procedure regarding mortality, morbidity (i.e., Clavien-Dindo score), weight loss (change in body mass index [BMI] and percentage of excess BMI loss [%EBMIL]), co-morbidities remission, and Gastrointestinal Quality of Life Index (GIQLI) score, were assessed. Thirty patients (24%) who had prior restrictive bariatric surgery (including 22 laparoscopic adjustable gastric bandings, 4 vertical banded gastroplasties, and 4 sleeve gastrectomies) underwent conversion to rSAGB. Ninety-six patients (76%) underwent primary SAGB (pSAGB group). Both groups were comparable in age, gender, BMI, and preoperative co-morbidities. Preoperative mean BMI of the rSAGB group was 45.5±7 kg/m(2). There were no deaths and the major complications rate was 10%. No increase in morbidity was found between the 2 groups. Two patients required conversion to RYGB after rSAGB because of intractable biliary reflux. At 5 years, mean BMI was 32 kg/m(2) and mean %EBMIL was 66% after rSAGB; no significant differences were found compared with pSAGB (BMI = 31 kg/m(2), %EBMIL = 73%). Co-morbidities and remission rates were statically similar. Overall, GIQLI score was significantly lower in the rSAGB group (104.1±17.6 versus 112.5±16.8, P = .025). Significant differences were found in "upper gastrointestinal symptoms" and "psychological" scores. At 5 years, rSAGB for a failed restrictive procedure was safe and effective, but quality of life and upper gastrointestinal function were lower compared

  18. Application specific compression : final report.

    Energy Technology Data Exchange (ETDEWEB)

    Melgaard, David Kennett; Byrne, Raymond Harry; Myers, Daniel S.; Harrison, Carol D.; Lee, David S.; Lewis, Phillip J.; Carlson, Jeffrey J.


    With the continuing development of more capable data gathering sensors, comes an increased demand on the bandwidth for transmitting larger quantities of data. To help counteract that trend, a study was undertaken to determine appropriate lossy data compression strategies for minimizing their impact on target detection and characterization. The survey of current compression techniques led us to the conclusion that wavelet compression was well suited for this purpose. Wavelet analysis essentially applies a low-pass and high-pass filter to the data, converting the data into the related coefficients that maintain spatial information as well as frequency information. Wavelet compression is achieved by zeroing the coefficients that pertain to the noise in the signal, i.e. the high frequency, low amplitude portion. This approach is well suited for our goal because it reduces the noise in the signal with only minimal impact on the larger, lower frequency target signatures. The resulting coefficients can then be encoded using lossless techniques with higher compression levels because of the lower entropy and significant number of zeros. No significant signal degradation or difficulties in target characterization or detection were observed or measured when wavelet compression was applied to simulated and real data, even when over 80% of the coefficients were zeroed. While the exact level of compression will be data set dependent, for the data sets we studied, compression factors over 10 were found to be satisfactory where conventional lossless techniques achieved levels of less than 3.

  19. Recent progress in compressible turbulence

    NARCIS (Netherlands)

    Chen, S.; Xia, Z.; Wang, Jianchun; Yang, Yantao


    In this paper, we review some recent studies on compressible turbulence conducted by the authors’ group, which include fundamental studies on compressible isotropic turbulence (CIT) and applied studies on developing a constrained large eddy simulation (CLES) for wall-bounded turbulence. In the first

  20. Streaming Compression of Hexahedral Meshes

    Energy Technology Data Exchange (ETDEWEB)

    Isenburg, M; Courbet, C


    We describe a method for streaming compression of hexahedral meshes. Given an interleaved stream of vertices and hexahedral our coder incrementally compresses the mesh in the presented order. Our coder is extremely memory efficient when the input stream documents when vertices are referenced for the last time (i.e. when it contains topological finalization tags). Our coder then continuously releases and reuses data structures that no longer contribute to compressing the remainder of the stream. This means in practice that our coder has only a small fraction of the whole mesh in memory at any time. We can therefore compress very large meshes - even meshes that do not file in memory. Compared to traditional, non-streaming approaches that load the entire mesh and globally reorder it during compression, our algorithm trades a less compact compressed representation for significant gains in speed, memory, and I/O efficiency. For example, on the 456k hexahedra 'blade' mesh, our coder is twice as fast and uses 88 times less memory (only 3.1 MB) with the compressed file increasing about 3% in size. We also present the first scheme for predictive compression of properties associated with hexahedral cells.