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Sample records for hydrodynamic limb vein

  1. In situ saphenous vein bypass for limb salvage.

    Science.gov (United States)

    Sarcina, A; Carlesi, R; Bellosta, R; Agrifoglio, G

    1993-02-01

    A total of 130 infrapopliteal in situ saphenous vein bypasses were performed in 128 patients between January 1980 and June 1991. The indication for surgery was critical ischaemia with impending limb loss in 121 patients; seven suffered from severe claudication. The distal anastomosis was to the popliteal artery below the knee in 60 cases (46.2%) and in 70 (53.8%) to the tibioperoneal arteries. The results, in terms of secondary patency and limb salvage rates, of the first 68 procedures (1980-1985) and subsequent 62 (1986-June 1991) were compared. In the first period, a secondary patency rate of 42.6% and a limb salvage rate of 67.0% were obtained, compared with 71.3 and 80.8% respectively in the second. These differences are significant for patency (P < 0.005) and limb salvage (P < 0.01). These results show that the in situ technique can give acceptable results but a learning period with a high percentage of early failures is to be expected.

  2. Upper limb vein anatomy before hemodialysis fistula creation: cross-sectional anatomy using MR venography

    International Nuclear Information System (INIS)

    Laissy, Jean-Pierre; Fernandez, Pedro; Karila-Cohen, Pascale; Chillon, Sylvie; Schouman-Claeys, Elisabeth; Delmas, Vincent; Dupuy, Emmanuel; Mignon, Francoise

    2003-01-01

    Preoperative imaging is indicated to discriminate patent, adequate superficial veins of the upper limbs undetectable by clinical inspection that could be anastomosed for the creation of a durable and functional hemodialysis fistula. The aim of this pictorial review is to provide a venous anatomic map of the upper limbs using MR venography (MRV) which could help surgeons before creation of hemodialysis access fistulas (AVF). At the level of the forearm, the antebrachial cephalic vein is the most commonly identified as patent. At the level of the elbow and distal arm, the cephalic vein is patent in 80% of normal subjects, and less often patent (23-26%) than basilic vein (33-38%) in patients. Overall, reading transaxial MR views can help for assessing upper limb vein anatomy before creation of a hemodialysis access fistula. (orig.)

  3. Upper limb vein anatomy before hemodialysis fistula creation: cross-sectional anatomy using MR venography

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    Laissy, Jean-Pierre; Fernandez, Pedro; Karila-Cohen, Pascale; Chillon, Sylvie; Schouman-Claeys, Elisabeth [Department of Radiology, Hopital Bichat, 46 rue Henri Huchard, 75877 Paris Cedex 18 (France); Delmas, Vincent [Department of Urology, Hopital Bichat, 46 rue Henri Huchard, 75877 Paris Cedex 18 (France); Dupuy, Emmanuel; Mignon, Francoise [Department of Nephrology, Hopital Bichat, 46 rue Henri Huchard, 75877 Paris Cedex 18 (France)

    2003-02-01

    Preoperative imaging is indicated to discriminate patent, adequate superficial veins of the upper limbs undetectable by clinical inspection that could be anastomosed for the creation of a durable and functional hemodialysis fistula. The aim of this pictorial review is to provide a venous anatomic map of the upper limbs using MR venography (MRV) which could help surgeons before creation of hemodialysis access fistulas (AVF). At the level of the forearm, the antebrachial cephalic vein is the most commonly identified as patent. At the level of the elbow and distal arm, the cephalic vein is patent in 80% of normal subjects, and less often patent (23-26%) than basilic vein (33-38%) in patients. Overall, reading transaxial MR views can help for assessing upper limb vein anatomy before creation of a hemodialysis access fistula. (orig.)

  4. Gigantism of the lower limb in Klippel-Trenaunay syndrome: anatomy of the lateral marginal vein.

    Science.gov (United States)

    Abdul-Rahman, N R; Mohammad, K F; Ibrahim, S

    2009-06-01

    The Klippel-Trenaunay syndrome is a combination of venous and capillary malformations associated with soft tissue and/or bony limb hypertrophy, with or without lymphatic malformations. Although persistent foetal veins are rare, the persistence of the lateral marginal vein is a common association in this syndrome. It results in venous hypertension, which gives rise to venous varicosities, which are commonly seen in this syndrome. This is a case report of a 28-year-old man with Klippel-Trenaunay syndrome, with persistence of the lateral marginal vein, affecting his right lower limb. He was treated with an above-knee amputation. The amputated limb was dissected to demonstrate the anatomy of the lateral marginal vein. To the best of the authors' knowledge, the gross anatomy of the lateral marginal vein has not been previously reported.

  5. Clinical effectiveness of DSA-guided foam sclerotherapy for varicose veins of lower limbs

    International Nuclear Information System (INIS)

    Fu Jianhua; He Xu; Chen Guoping; Gu Jianping; Wang Yafei

    2011-01-01

    Objective: To investigate the clinical effect of DSA-guided foam sclerotherapy for varicose veins of lower limbs. Methods: A total of 25 diseased limbs in 20 patients with varicose veins were treated with foam sclerotherapy. The patients were followed up for six months. Sodium morrhuate, used as the sclerosant, was foamed with air by using Tessari's method, with liquid-gas ratio of 1 : 4. The clinical effectiveness was estimated by CEAP, clinical signs and symptoms. Results: A total of 25 limbs in 20 patients with varicose veins were successfully treated with foam sclerotherapy. The technical success rate was 100%. No serious complications such as pulmonary embolism occurred. Phlebitis was observed in two cases at 2 days 4 days after foam sclerotherapy respectively which was relieved after anti-inflammatory medication for 3 days. At the time of discharge, excellent result was seen in 12 (48%) limbs, good effect in 13 (52%) limbs. The total effective rate was 100%. Six months after the treatment, excellent effect was obtained in 15 (60%) limbs and good effect was seen in 10 (40%) limbs. The total effective rate was 100%. Conclusion: DSA-guided foam sclerotherapy is a safe, effective and micro-invasive treatment for varicose veins of lower limbs with high technical success rate, although the long-term clinical effect needs to be further evaluated. (authors)

  6. Embolization of Incompetent Pelvic Veins for the Treatment of Recurrent Varicose Veins in Lower Limbs and Pelvic Congestion Syndrome

    International Nuclear Information System (INIS)

    Meneses, Luis; Fava, Mario; Diaz, Pía; Andía, Marcelo; Tejos, Cristian; Irarrazabal, Pablo; Uribe, Sergio

    2013-01-01

    We present our experience with embolization of incompetent pelvic veins (IPV) in women with recurrence of varicose veins (VV) in lower limbs, as well as symptoms of pelvic congestion syndrome (PCS), after first surgery. In addition, we evaluated the effects of embolization in decreasing the symptoms of VV before surgery as well as its effects on PCS symptoms. We included 10 women who had consulted a vascular surgeon because of recurrent VV in lower limbs after surgery. All of these patients were included in the study because they also had symptoms of PCS, probably due to IPV. In patients who had confirmed IPV, we performed embolization before a second surgery. VV and PCS were assessed before and at 3 months after embolization (before the second surgery) using a venous clinical severity score (VCSS) and a visual analog pain scale (VAS), respectively. Patients were controlled between 3 and 6 months after embolization. Paired Student t test analysis was used for comparing data before and after embolization. Fifteen vein segments in 10 women were suitable for embolization. There was a significant (p < 0.001) decrease of VCSS after embolization, and recurrence of VV was not detected within a period of 6 months. There was also significant (p < 0.01) relief of chronic pelvic pain related to PCS evaluated using VAS at 3 months after embolization. Embolization decreases the risk of VV recurrence after surgery and also improves PCS symptoms in women with VV in lower limbs and IPV.

  7. Embolization of Incompetent Pelvic Veins for the Treatment of Recurrent Varicose Veins in Lower Limbs and Pelvic Congestion Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Meneses, Luis, E-mail: lmeneseq@gmail.com; Fava, Mario; Diaz, Pia; Andia, Marcelo [Pontificia Universidad Catolica de Chile, Radiology Department and Biomedical Imaging Center (Chile); Tejos, Cristian; Irarrazabal, Pablo [Pontificia Universidad Catolica de Chile, Biomedical Imaging Center (Chile); Uribe, Sergio, E-mail: suribe@med.puc.cl [Pontificia Universidad Catolica de Chile, Radiology Department and Biomedical Imaging Center (Chile)

    2013-02-15

    We present our experience with embolization of incompetent pelvic veins (IPV) in women with recurrence of varicose veins (VV) in lower limbs, as well as symptoms of pelvic congestion syndrome (PCS), after first surgery. In addition, we evaluated the effects of embolization in decreasing the symptoms of VV before surgery as well as its effects on PCS symptoms. We included 10 women who had consulted a vascular surgeon because of recurrent VV in lower limbs after surgery. All of these patients were included in the study because they also had symptoms of PCS, probably due to IPV. In patients who had confirmed IPV, we performed embolization before a second surgery. VV and PCS were assessed before and at 3 months after embolization (before the second surgery) using a venous clinical severity score (VCSS) and a visual analog pain scale (VAS), respectively. Patients were controlled between 3 and 6 months after embolization. Paired Student t test analysis was used for comparing data before and after embolization. Fifteen vein segments in 10 women were suitable for embolization. There was a significant (p < 0.001) decrease of VCSS after embolization, and recurrence of VV was not detected within a period of 6 months. There was also significant (p < 0.01) relief of chronic pelvic pain related to PCS evaluated using VAS at 3 months after embolization. Embolization decreases the risk of VV recurrence after surgery and also improves PCS symptoms in women with VV in lower limbs and IPV.

  8. The value of MR angiography in the diagnosis of deep vein thrombosis of the lower limbs: comparative study with DSA

    International Nuclear Information System (INIS)

    Feng Min; Wang Shuzhi; Gu Jianping; Sun Jun; Mao Cunnan; Lu Lingquan; Yin Xindao

    2007-01-01

    Objective: To assess the clinical values of MR angiography (MRA) in the detection of deep vein thrombosis of the lower limbs. Methods: Two-dimensional time of flight (2D TOF) MRA was performed in thirty patients who were suspected of having deep vein thrombosis in the lower limbs. The findings of MRA were compared to that of digital subtraction angiography (DSA). Results: twenty-five cases showed deep vein thrombosis in the lower limbs, the MRA findings included venous filling defect (14 cases), occlusions and interruptions of veins (8 cases), venous recanalizations (3 cases), collateral veins (25 cases). Taking the results of DSA as a golden standard, MRA detected all of the affected cases with only one case as the false positive. Conclusion: 2D TOF MRA is a method of choice in the diagnosis of deep vein thrombosis of the lower limbs. (authors)

  9. Sclerotherapy for Reticular Veins in the Lower Limbs: A Triple-Blind Randomized Clinical Trial.

    Science.gov (United States)

    Bertanha, Matheus; Jaldin, Rodrigo Gibin; Moura, Regina; Pimenta, Rafael Elias Farres; Mariúba, Jamil Victor de Oliveira; Lúcio Filho, Carlos Eduardo Pinheiro; Alcantara, Giovana Piteri; Padovani, Carlos Roberto; Yoshida, Winston Bonetti; Sobreira, Marcone Lima

    2017-12-01

    Reticular veins are subdermal veins located in the lower limbs and are mainly associated with aesthetic complaints. Although sclerotherapy is the treatment of choice for reticular veins in the lower limbs, no consensus has been reached regarding to the optimal sclerosant. To compare the efficacy and safety of 2 sclerosants used to treat reticular veins: 0.2% polidocanol diluted in 70% hypertonic glucose (HG) (group 1) vs 75% HG alone (group 2). Prospective, randomized, triple-blind, controlled, parallel-group clinical trial with patients randomly assigned in a 1:1 ratio between the 2 treatment groups from March through December 2014, with 2 months' follow-up. The study was conducted in a single academic medical center. Eligible participants were all women, aged 18 to 69 years, who had at least 1 reticular vein with a minimum length of 10 cm in 1 of their lower limbs. The patients underwent sclerotherapy in a single intervention with either 0.2% polidocanol plus 70% HG or 75% HG alone to eliminate reticular veins. The primary efficacy end point was the disappearance of the reticular veins within 60 days after treatment with sclerotherapy. The reticular veins were measured on images obtained before treatment and after treatment using ImageJ software. Safety outcomes were analyzed immediately after treatment and 7 days and 60 days after treatment and included serious adverse events (eg, deep vein thrombosis and systemic complications) and minor adverse events (eg, pigmentation, edema, telangiectatic matting, and hematomas). Ninety-three women completed the study, median (interquartile range) age 43.0 (24.0-61.0) years for group 1 and 41.0 (27.0-62.0) years for group 2. Sclerotherapy with 0.2% polidocanol plus 70% HG was significantly more effective than with 75% HG alone in eliminating reticular veins from the treated area (95.17% vs 85.40%; P vein pigmentation length for group 1 and 7.09% for group 2, with no significant difference between the groups (P = .09

  10. Biomarkers of low-grade inflammation in primary varicose veins of the lower limbs.

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    Flore, R; Ponziani, F R; Gerardino, L; Santoliquido, A; Di Giorgio, A; Lupascu, A; Nesci, A; Tondi, P

    2015-02-01

    To analyze serum biomarkers of CVD in selected patients with primary axial reflux of great saphenous vein in one or both lower limbs. Ninety-six patients affected by uncomplicated varicose veins, were enrolled in the study. A unilateral, primary axial reflux in great saphenous veins was detected in 54 patients (U-CVD group) and a bilateral one in 42 (B-CVD group). Sixty-five age and sex-matched subjects without venous reflux were enrolled as controls. Mean venous pressure of both lower limbs at the distal great saphenous vein (mGSVP) and venous reflux were measured by continuous-wave Doppler ultrasound and echoduplex scanning, respectively. Reactive Oxygen Species (ROS), tissue Plasminogen Activator (t-PA) and its Inhibitor 1 (PAI-1) activities, Hematocrit (HTC), White Blood Cells (WBC), Neutrophyls (NEU), Platelets (PLT), Fibrinogen (FIB) and Blood Viscosity (BV) were assessed in blood samples drawn from the antecubital vein. B-CVD group showed higher fibrinogen values (p < 0.005) and higher mean venous pressure (0 < 0.0001) in comparison to controls, while U-CVD did not. No difference was found between both groups and controls for all the other parameters. Increased fibrinogen levels in patients with bilateral varicose veins may represent an early warning signal, as it could be associated to the long-term progression of chronic venous disease.

  11. Endovenous and perivenous 808-nm laser treatment of lower limb collateral, reticular and telangiectasiac veins.

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    Bugiantella, Walter; Bovani, Bruno; Zini, Francesco

    2017-02-01

    Visible leg veins are not only a mere aesthetic problem, but may also be manifestation of altered microcirculation and superficial venous incompetency. Sclerotherapy is the first-line treatment for leg veins veins: the greater, the harder photothermolysis is, so that higher powers may lead to aesthetic complications. We report our experience in the treatment of small collateral (reticular and telangiectasiac veins with endovenous and perivenous 808-nm laser. Overall, 325 treatments were performed on 113 patients. The endovenous and perivenous treatment proved to be a safe, quick, well-tolerated and effective procedure. It ensured an optimal closure of the target veins right from the first treatment in most patients. Sometimes, a second treatment of the same vein was needed. The endovenous and perivenous 808-nm laser photothermal sclerosis ensures a quick coagulation-fibrosis of the veins of the lower limbs, thus allowing rapid healing and good aesthetic results (stable in 95% of patients after an average follow-up of 18 months). It may be an effective alternative to sclerotherapy.

  12. Phlebographic variants of valvular insufficiency of deep veins in varicose disease of the lower limbs

    International Nuclear Information System (INIS)

    Firsov, E.F.; Gladkikh, V.G.; Lazarenko, V.A.; Shevelev, E.L.; Pashin, S.V.

    1995-01-01

    Analysis of clinical data and results of retrograde femoral and popliteal phlebographics in 108 patients with varicose disease of the lower limbs permitted the authors to propose a three-stage classification of valvular insufficiency of the deep veins and to demonstrate that the disease compensation stages are related to the presence and degree of retrograde blood flow. Analysis of retrograde phlebograms helped single out 8 variants of retrograde blood flow in the deep femoral veins and 12 variants in the deep veins of the shin with valvular insufficiency thereof, which is practically important for interpretation of x-ray findings and for the choice of the optimal method and volume of surgical correction of this vascular abnormality. 4 refs.; 5 figs

  13. Pathophysiology of Venous Thromboembolism with Respect to the Anatomical Features of the Deep Veins of Lower Limbs: A Review.

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    Ro, Ayako; Kageyama, Norimasa; Mukai, Toshiji

    2017-06-25

    Here the pathophysiology of venous thromboembolism is reviewed with respect to the anatomical features of the deep veins of lower limbs. A thrombus is less likely to form in the thigh veins compared with that in the calf veins; however, clinical symptoms are more likely to appear in the thigh veins owing to vascular occlusion. When a patient is bedridden, thrombosis is more likely to occur in the intramuscular vein, which mainly depends on muscular pumping and the venous valve, rather than in the three crural branches, which mainly depends on the pulsation of the accompanying artery. Thrombi are prone to be generated in the soleal vein compared with those in the gastrocnemius vein because of the vein and muscle structures. A soleal vein thrombosis grows toward the proximal veins along the drainage veins. To prevent a sudden pulmonary thromboembolism-related death in bedridden patients, preventing soleal vein thrombus formation and observing the thrombus proximal propagation via the drainage veins are clinically important. When deep vein thrombosis occurs, avoiding embolization and sequela caused by the thrombus organization is necessary.

  14. Deep vein thrombosis of the lower limbs: A retrospective analysis of doppler ultrasound findings

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    Sanjay M Khaladkar

    2014-01-01

    Full Text Available Background: Deep venous thrombosis (DVT of lower limbs is one of the most common cause for the majority of deaths caused by pulmonary embolism. Many medical and surgical disorders are complicated by DVT. Most venous thrombi are clinically silent. B-mode and color Doppler imaging is needed for early diagnosis of DVT to prevent complications and sequalae of DVT. Aim and Objectives: The objectives of the following study were to evaluate the role of Doppler as an imaging modality in diagnosing DVT of lower limbs, to study the spectrum of findings on Doppler ultrasound in patients with DVT. Materials and Methods: Retrospective descriptive analysis of 78 patients of DVT diagnosed on Doppler. Results: Nearly 74% of the patients were males and 26% were females with majority belonging to fifth decade (26%. 75 (96.1% cases showed unilateral while 3 (3.9% cases showed bilateral lower limb involvement. In our study, predominant distribution of thrombus was found to be in above knee region with 69/78 (88.5% patients having thrombus in the superficial femoral vein. Popliteal vein was involved in 54/78 (69.2% patients. Complete thrombosis was observed in 54/78 (69% cases, while partial thrombosis was observed in 24/78 (31% cases. Subacute stage was seen in 42 cases (53.8%, acute stage in 23 cases (29.5% while chronic stage in 13 cases (16.7%. 71 cases (91% had multiple contiguous segmental involvement, whereas 7 cases (9% had isolated vein involvement. Conclusion: Color Doppler is useful in diagnosing DVT in symptomatic and at risk patients and provides a non-invasive method of investigation. It is also helpful in evaluating the site, extent and stage of thrombus.

  15. [Variants of anatomical structure of lower-limb veins as a possible cause of the development of primary varicosity].

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    Vakhitov, M Kh; Bol'shakov, O P

    2011-01-01

    In order to reveal anatomical prerequisites for the development of primary varicose veins we investigated the structure of the venous system on a total of 53 adult human cadaveric lower extremities. Congenital morphological grounds providing the phlebohaemodynemics of the lower limbs are ambiguous in different individual forms. We revealed a total of 18 variants of the structure of deep veins, reflecting various stages of the embryonic development. In 34.1% of cases we saw the forms characteristic of incomplete reduction and unfinished transformation, with 30.2% of cases showing the utmost degree of reduction and transformation. An inadequate outflow along the deep veins conditioned by their anatomical structure is a prerequisite for the development of valvular insufficiency and venous reflux to the superficial veins followed by varicose transformation thereof

  16. Evaluation of the pharmacokinetics of imipenem following regional limb perfusion using the saphenous and the cephalic veins in standing horses.

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    Kelmer, G; Tatz, A J; Kdoshim, E; Britzi, M; Segev, G

    2017-10-01

    This prospective experimental study goal was to determine the pharmacokinetics of imipenem after intravenous regional limb perfusion (IV-RLP) in standing horses. Nine horses participated in the study; that was approved by the University Animal Care and Use Committee. One thoracic limb or one pelvic limb of each horse was randomly selected. After the veins were catheterized, an Esmarch bandage tourniquet was applied and the catheter was injected with a solution containing 500mg of imipenem. Synovial fluid samples were collected from the fetlock joint and blood samples were collected from the jugular vein. All samples were analyzed for imipenem concentration using liquid chromatography mass spectrometry. Cmax of imipenem in the fetlock joint using the cephalic and the saphenous vein was 87 and 60μg⁄mL, respectively. The results indicate that by performing IV-RLP using the cephalic/saphenous, one can achieve imipenem concentrations in the fetlock joint that are well above the MIC of most susceptible pathogens including resistant bacteria such as Methicillin Resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Thus, with selective; judicious use, RLP with imipenem can markedly increase treatment efficacy of severe distal limb infections in horses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. EVALUATION OF “SEPS” PROCEDURE IN THE MANAGEMENT OF PRIMARY VARICOSE VEINS WITH INCOMPETENT LOWER LIMB PERFORATOR

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    Shaik Ahmad

    2016-03-01

    Full Text Available BACKGROUND Varicose veins affect at least 1 out of 5 in the world and the cost of health care for the society is significant. In a developing country like India, study encompassing the clinical evaluation and management of lower limb varicose veins on the conventional lines seems a necessity to improve the quality care with the available resources. OBJECTIVES To study the relation between site of incompetence and complications, pattern of complications, surgical management and its outcome for lower limb varicose veins. METHODS A total 26 number of patients with primary varicose veins admitted, investigated, operated and followed up. Final outcome evaluated. All the information was taken down in the proforma, designed for the study. RESULTS In the study, it was noted that the varicose veins affect younger, adult, and middle age population. (20 to 60 years. Majority of the patients were male (84.60%. Perforator incompetence only = 42.3% (n=11. Perforator incompetence + saphenofemoral/saphenopopliteal incompetence seen in 57.7%. Long saphenous vein involvement was seen in 90.5% of the patients and both LSV and SSV involvement in 9.5%. A greater portion of the patients had combined valvular incompetence (69.56%. The mean ulcer healing time in our study was 2.8 weeks following surgery (90%. Residual incompetent perforators are seen in 7.6% (n=2. New incompetent perforators seen in 7.6% (n=2. Postoperative wound infection of the incision of SPJ ligation was seen in 3.8% (n=1 of the patients, but not the SEPS wound infection and the total complication rate was 3.85%. The mean postoperative stay for patients undergoing SEPS procedure alone was 3.6 days. The mean postoperative stay for patients who underwent perforator ligation with concomitant stripping procedure was 5 days. INTERPRETATION AND CONCLUSION Majority of the patients present with complications of varicose vein with combined valvular incompetence and surgical treatment with stripping of path

  18. Simultaneous Iliac Vein Bovine Pericardial Patch Venoplasty and Creation of PTFE Lower Limb Arteriovenous Fistula Graft for Rescue Vascular Access.

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    Meecham, Lewis; Fisher, Owain; Kirby, George; Evans, Richard; Buxton, Pauline; Legge, Jocelyn; Rajagopalan, Sriram; Asquith, John; Pherwani, Arun

    2016-10-01

    We present a case of external iliac vein patch venoplasty to accommodate rescue vascular access via a polytetrafluoroethylene loop arteriovenous fistula graft (AVG) for a patient with multiple central venous stenoses. A 35-year-old female with anti-glomerular basement membrane antibody disease required rescue vascular access for hemodialysis. Repeated occlusion and/or thrombosis of long-term central venous access cannulae, to facilitate dialysis, had caused stenosis of brachiocephalic veins: right external iliac vein and occlusion of the left common iliac vein. A previous right brachiobasilic fistula had occluded within 1 year. No other upper limb options for arteriovenous fistula (AVF) were available. A right external iliac vein bovine patch angioplasty concurrently with a polytetrafluoroethylene AV graft between common femoral artery and common femoral vein was performed to restore venous patency and allow rescue dialysis access. At 3-year follow-up, the fistula remains widely patent with 2 L/min flow rates and no recurrent stenosis to the treated iliac vein. She has not required any further surgical or interventional radiological procedures to maintain fistula or central venous patency. Central venous stenosis or occlusion is common for patients requiring dialysis, especially those with multiple previous long-term central venous cannulations. If restriction of outflow is present, AVF may fail. Venous patch angioplasty in these cases is a successful technique, allowing AVF formation and long-term patency. Central venous stenosis can be treated successfully with patch venoplasty to accommodate AVF/AVG formation for rescue vascular access; this is a potentially lifesaving intervention for patients requiring dialysis. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Extraluminal venous interruption for free-floating thrombus in the deep veins of lower limbs.

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    Casian, D; Gutsu, E; Culiuc, V

    2010-01-01

    The free-floating thrombus (FFT) represents a particular form of deep vein thrombosis with extremely high potential of fatal pulmonary embolism. The purpose of the study was to evaluate the early results of aggressive surgical approach to FFT. During the period 2005-2008 years FFT was diagnosed in 13 patients. Demographic characteristics of patients: medium age--54.7 years, male--76.9%, significant comorbidity--5 (38.5%) cases. Localization of FFT: superficial femoral vein (SFV)--5 (38.5%), common femoral vein (CFV)--4 (30.7%), external iliac vein (EIV)--2 (15.4%), inferior cava vein (ICV)--2 (15.4%). Manifestations of previous pulmonary embolism were documented preoperatively in 3 (23.1%) cases. The following emergency surgical procedures were performed: ligation--3 (23.1%) or plication--2 (15.4%) of SFV; plication of CFV--5 (38.5%) patients, combined in 4 cases with partial thrombectomy (free-floating part of thrombus); plication of common iliac vein--1 (7.6%); plication of ICV--2 (15.4%) cases. Primary or recurrent cases of clinically significant pulmonary embolism were not detected in the postoperative period. The accumulated experience of surgical management of patients with FFT reveals the important role of deep vein ligation/plication in prevention of fatal pulmonary embolism.

  20. Innominate Vein Stenosis in Association with Ipsilateral Hyperdynamic Brachiobasilic Fistula Causing Ipsilateral Limb and Hemifacial Swelling.

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    Narendra, J B; Sreenivas, J; Karthikeyan, V S; Nagaraja, N H

    2017-01-01

    A 34-year-old hypertensive woman with a hyperdynamic, left brachiobasilic dialysis fistula presented with a long history of throbbing in her head and swelling of the left side of the face. Tight stenosis of left brachiocephalic vein was found to be causing retrograde flow into the left jugular vein which normalized after dilatation and stenting with resolution of all the symptoms and patient is asymptomatic for 1 year.

  1. Clinical course and effective treatment of varicose vein of lower limb in diabetic patients

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    Yu.O. Syniachenko

    2017-02-01

    Full Text Available Background. Type 2 diabetes mellitus (DM2 is a risk factor for arteriosclerosis of the lower extremities, and the relationship with the state of the feet venous vascular territory remains insufficiently studied, the effectiveness of surgical treatment of patients with varicose veins is not defined. Objective: to analyze the clinical course of foot varicose veins and the effectiveness of medical measures on the background of DM2. Materials and methods. The study included 302 patients (227 men and 75 women aged 29–72 years old, 16 % of which had previous phlebothrombosis and the prevalece of II, III, IV, V and VI class of venous insufficiency was 10, 14, 37 16 and 23 %, respectively. 263 patients underwent endovenous laser coagulation, and 39 — the traditional phlebectomy and ligation of perforating veins. Results. Among the examined patients with varicose veins of lower extremities DM2 was diagnosed in 9 % of cases, more often in males and elderly patients on the background of atherosclerosis of the foot vessels (iliac, femoral, tibial, popliteal artery, which was accompanied by more frequent involvement of the great saphenous vein in the process and its gate extension, the prevalence of severe grades of venous insufficiency, significantly worse the results of surgical treatment of varicose veins and greater frequency of complications, despite more frequent using of rivaroxaban and low molecular weight heparins, and the effectiveness of endovenous laser ablation after four weeks of its implementation is inferior to that in the group without DM2, while glycemic index inversely correlated with the surface tension of the venous blood, which has prognostic significance in the context of future medical interventions. Conclusions. The presence of DM2 is a risk factor for more severe feet varicose veins, is a negative predictive factor in the effectiveness of surgical treatment of the disease and the complications number.

  2. D-dimer as an applicable test for detection of posttraumatic deep vein thrombosis in lower limb fracture.

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    Bakhshi, Hooman; Alavi-Moghaddam, Mostafa; Wu, Karin C; Imami, Mohammad; Banasiri, Mohammad

    2012-06-01

    Measuring the plasma levels of D-dimer is an accurate and easy modality to detect deep vein thrombosis (DVT) in nontraumatic settings. However, the diagnostic reliability of D-dimer assays in detecting posttraumatic DVT among patients with lower limb fracture undergoing orthopedic surgery is not validated. In this study, 141 patients with lower limb fracture admitted through the emergency department and undergoing orthopedic surgery were enrolled. Postoperative venous blood samples for D-dimer assay were taken on the 1st, 7th, and 28th postoperative days. Color Doppler sonography examination of both lower limbs was performed at the same time as a standard test. Eight out of the 141 patients (6%) had acute DVT based on Color Doppler sonography. Mean D-dimer was 2160 ng/mL in DVT positive patients and 864 in DVT negative patients. D-dimer levels greater than 1000 ng/mL were 100% sensitive and 71% specific for detecting postoperative DVT. D-dimer assay is a useful and sensitive test for detecting posttraumatic DVT.

  3. Ultrasonographic analysis in vitro of parietal thickness of lower limb varicose veins.

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    Bruschi, E; Como, G; Zuiani, C; Segatto, E; Rocco, M; Biasi, G; Bazzocchi, M

    2006-09-01

    The aim of this study was to evaluate the ability of ultrasound (US) to measure the parietal thickness of varicose veins. In a blind in vitro analysis, 28 great saphenous veins, obtained after stripping surgery from 28 patients with chronic venous insufficiency, were examined with a digital US scanner ATL-HDI5000, linear 5-1 to 2-MHz broadband probe, compound imaging technique and analogic-digital zooming. We obtained one to three progressive measurements for each vein wall (total 67 parietal thicknesses). The samples, fixed in formalin, were sent to the pathology laboratory: sections were obtained at the same level of the sonographic planes, and images were obtained by digital camera mounted on an optical microscope. Measurements obtained at histology were considered as the gold standard. K-statistic was applied to compare sonographic and histologic measurements. Considering only the hypoechoic wall portion, 29/29 (100%) diagnoses of hypotrophy (K=0.91), 19/22 (86%) diagnoses of normotrophy (K=0,47) and 12/16 (75%) diagnoses of hypertrophy (K=0.7) were obtained by sonography. In our preliminary experience, the in vitro study of varicose veins allows precise, at least morphological, detection of hypotrophic walls. If these preliminary data are confirmed in vivo, sonography could be used to discriminate patients eligible for conservative treatment instead of surgery.

  4. Post ablation recanalization of varicose veins of the limbs: Comparison ablation method of mechanochemical and laser procedure

    Science.gov (United States)

    Suhartono, R.; Irfan, W.; Wangge, G.; Moenadjat, Y.; Destanto, W. I.

    2017-08-01

    Endovenous ablation has been performed for varicose veins of the limbs in Indonesia since 2010. Endovenous laser ablation (EVLA) therapy has been performed in Cipto Mangunkusumo Hospital (RSCM) in Jakarta, and mechanochemical ablation (MOCA) has been conducted in Fatmawati Hospital. This was a descriptive analytical study, with a cross-sectional design to analyze post-ablation recanalization after MOCA and EVLA procedures. Patients who had undergone MOCA or EVLA treatment were interviewed 3-18 months after the procedures. All the patients underwent vascular ultrasonography (USG) of the operated limb to assess recanalization. Secondary presurgery data were obtained from the patients’ from patients’ medical records. The clinical characteristics of the subjects were recorded to compare the potential correlation between these characteristics and recanalization post-MOCA and EVLA procedures. All the data were analyzed using SPSS ver. 20.0. The study consisted of 43 limbs: 24 treated by MOCA and 19 treated by EVLA. Most subjects in the MOCA group were 7 mm in 13/19 extremities. In the MOCA group, total recanalization occurred in 2/24 extremities, and partial recanalization occurred in 8/24 extremities. In the EVLA group, total recanalization occurred in 1/19 extremities, and partial recanalization occurred in 3/19 extremities. The association between the clinical characteristics of the patients and recanalization was not statistically significant (p > 0.05). The recanalization tendency was higher in the MOCA group than in the EVLA group. Although there was no statistically significant association between the clinical characteristics of the patients and recanalization, the largest diameter of the VSM presurgery (>7 mm) was higher in 3/4 extremities in the MOCA group, as compared to 3/13 extremities in the EVLA group.

  5. Deep vein thrombosis of the lower limbs in intravenous drug users

    Directory of Open Access Journals (Sweden)

    Wiesława Kwiatkowska

    2015-04-01

    Full Text Available Addiction to intravenously administered drugs has been a serious epidemiological problem for years. Among the related health complications, deep vein thrombosis (DVT is one of the most important. This paper provides an illustrative presentation of DVT in intravenous drug users (IDUs, HIV-positive subjects among them.We searched PubMed, Ovid Journals, Scopus, ScienceDirect, Cochrane Library, Google Scholar and references from articles obtained. The main terms used to identify appropriate studies of DVT in IDUs were ‘intravenous drug users’, ‘substance-related disorders’ and ‘deep vein thrombosis’.No guidelines exist for DVT in intravenous drug users. As many as 47.6% of IDUs report having suffered from DVT. IDUs may constitute approx. 50% of patients under 40 years of age with DVT, this being promoted by multiple vein punctures, groin injections, lack of sterility, insoluble microparticles and other factors. The clinical appearance is more complex than in the general population, which also makes prognosis more difficult. HIV infection can worsen DVT. It often appears as proximal iliofemoral thrombosis, accompanied by local and general complications. Ultrasound with a compression test is an objective method of choice, but must often be complemented with computed tomography. Antithrombotic therapy in IDUs needs to be applied individually. The optimal method is supervised therapy at addiction treatment services.Individual and public preventive measures, among them locally prepared guidelines for DVT in IDUs, may be the most important processes capable of effectively reducing the morbidity of septic and non-septic DVT.

  6. Combined treatment of acute deep vein thrombosis of the lower limbs

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    Vasylij Rusin

    2017-06-01

    Full Text Available The article represents the combined treatment results analysis of 50 patients with deep vein thromboses of inferior vena cava system. The complex clinical and instrumental examination of patients included duplex ultrasound scan, X-ray phlebography, multislice computed tomography with intravenous contrast and radionuclide fleboscintigrahpy. All patients were performed the regional thrombolytic therapy, combined with an open palliative thrombectomy in 19 (38% patients and endovascular implantation of a temporary or constant cava-filter in 31 (62% patients. In postoperative period for 12 months’ monitoring the local and general complications after combined treatment were found in 4 (8.0% out of 50 patients, who were performed the combined treatment.

  7. Sympathetic responses during saline infusion into the veins of an occluded limb.

    Science.gov (United States)

    Cui, Jian; McQuillan, Patrick; Moradkhan, Raman; Pagana, Charles; Sinoway, Lawrence I

    2009-07-15

    Animal studies have shown that the increased intravenous pressure stimulates the group III and IV muscle afferent fibres, and in turn induce cardiovascular responses. However, this pathway of autonomic regulation has not been examined in humans. The aim of this study was to examine the hypothesis that infusion of saline into the venous circulation of an arterially occluded vascular bed evokes sympathetic activation in healthy individuals. Blood pressure, heart rate, and muscle sympathetic nerve activity (MSNA) responses were assessed in 19 young healthy subjects during local infusion of 40 ml saline into a forearm vein in the circulatory arrested condition. From baseline (11.8 +/- 1.2 bursts min(-1)), MSNA increased significantly during the saline infusion (22.5 +/- 2.6 bursts min(-1), P Blood pressure also increased significantly during the saline infusion. Three control trials were performed during separate visits. The results from the control trial show that the observed MSNA and blood pressure responses were not due to muscle ischaemia. The present data show that saline infusion into the venous circulation of an arterially occluded vascular bed induces sympathetic activation and an increase in blood pressure. We speculate that the infusion under such conditions stimulates the afferent endings near the vessels, and evokes the sympathetic activation.

  8. Preservação da veia safena magna na cirurgia de varizes dos membros inferiores Varicose vein surgery in lower limbs with preservation of the great saphenous vein

    Directory of Open Access Journals (Sweden)

    Hamilton Almeida Rollo

    2009-06-01

    Full Text Available A veia safena magna autóloga é o melhor substituto arterial nas revascularizações dos membros inferiores, importante na revascularização do miocárdio e pode ser utilizada nas cirurgias do sistema venoso e nos traumas das extremidades. A fleboextração aumenta os riscos de lesões linfáticas e neurológicas. Assim, no tratamento das varizes primárias dos membros inferiores por meio da cirurgia ou de outras técnicas, a preservação da safena é recomendável se ela for normal ou apresentar alterações que ainda permitam sua preservação pela correção da causa desencadeante. Tal correção pode ser feita por técnicas cirúrgicas. Entre elas, a cura hemodinâmica da insuficiência venosa em ambulatório (CHIVA tem mostrado bons resultados. Recentemente, um ensaio clínico randomizado e controlado foi publicado comprovando sua eficácia. Outra técnica bastante utilizada é a da ligadura rasante da junção safenofemoral + crossectomia + ligadura das tributárias de crossa, com a qual se tem obtido resultados contraditórios. Finalmente, as técnicas que corrigem a insuficiência da safena reparando as valvas ostial e pré-ostial (valvoplastia externa são mais fisiológicas. Um ensaio clínico internacional multicêntrico, randomizado e controlado, testando um novo dispositivo, está sendo realizado, com resultados iniciais favoráveis. Este estudo pretende fazer uma revisão sobre as técnicas utilizadas na preservação da safena magna.The autologous great saphenous vein is the most effective bypass choice for lower limb revascularization, playing an important role in myocardial revascularization, and can be used in venous system surgeries and extremity traumas. Stripping increases the risk of lymphatic lesions and nerve damage. Therefore, when surgery or other techniques are used to treat primary varicose veins in the lower limbs, preservation of the saphenous vein is a desirable objective whenever the vein remains healthy or

  9. Magnetic resonance direct thrombus imaging at 3 T field strength in patients with lower limb deep vein thrombosis: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, S.A. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); O' Regan, D.P. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom)]. E-mail: declan.oregan@imperial.ac.uk; Gibson, D. [Imaging Department, Hammersmith Hospitals NHS Trust, London (United Kingdom); Cunningham, C. [Imaging Department, Hammersmith Hospitals NHS Trust, London (United Kingdom); Fitzpatrick, J. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); Allsop, J. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); Larkman, D.J. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom); Hajnal, J.V. [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom)

    2006-03-15

    AIM: To investigate the feasibility of imaging lower limb deep vein thrombosis using magnetic resonance imaging (MRI) at 3.0 T magnetic field strength with an optimized a T1 magnetization prepared rapid gradient echo technique (MP-RAGE) in patients with normal volunteers as controls. MATERIALS AND METHODS: Patients with deep vein thrombosis (n=4), thrombophlebitis (n=2) and healthy volunteers (n=9) were studied. MRI of the distal thigh and upper calf was performed at 3.0 T with MP-RAGE using two pre-pulses to suppress blood and fat (flip angle 15{sup o}, echo time 5 ms, and repetition time 10 ms). A qualitative analysis was performed for detection of thrombi and image quality. Contrast-to-noise ratios were determined in thrombosed and patent veins. RESULTS: Thrombi were clearly visible as high-signal intensity structures with good suppression of the anatomical background. A blinded reader accurately diagnosed 15 out of 16 cases. The contrast-to-noise ratio measurements showed a positive contrast of thrombus over background muscle 16.9 (SD 4.3, 95% CI: 12.5-21.3) and a negative contrast of the lumen to muscle in patent veins of normal volunteers -7.8 (SD 4.3, 95% CI: -11.1 to -4.5), with p=0.0015. CONCLUSION: Thrombi generate high signal intensity at 3.0 T allowing for their direct visualization if flowing blood, stationary blood and fat are sufficiently suppressed. This preliminary data supports the development of these techniques for other vascular applications.

  10. Trans-jugular catheter-directed thrombolysis combined with trans-dorsalis pedis vein thrombolysis for the treatment of deep venous thrombosis of the lower limbs

    International Nuclear Information System (INIS)

    Qian Jiesheng; Li Zhengran; Jiang Zaibo; Zhu Kangshun; Guan Shouhai; Zhou Bing; Xu Changmou; He Keke; Shang Hong

    2009-01-01

    Objective: To investigate the feasibility and efficacy of trans-jugular catheter-directed thrombolysis (CDT) together with trans-dorsalis pedis vein thrombolysis for the treatment of deep venous thrombosis (DVT) of the lower limbs. Methods: Jugular vein puncture, indwelling catheter and placement of IVC filter were performed in 18 patients with DVT (study group) followed by continuous trans-jugular CDT together with trans-dorsalis pedis vein thrombolysis. During the corresponding period, 16 patients with DVT (control group) received trans-dorsalis pedis vein thrombolysis only. Results: The thrombolytic time and total dose of urokinase in study group and control group were (6.6 ± 2.3) days, (5.52 ± 2.24) x 106 units and (8.2 ± 1.4) days, (7.00 ± 1.66) x 106 units respectively. The thrombolytic time and total dose of urokinase in study group were significantly lower than that in control group (P < 0.05). After the treatment the thigh circumference and calf circumference in study group showed a reduction of (4.6 ± 2.1) cm and (4.0 ± 2.1) cm respectively, which were (3.2 ± 1.7) cm and (2.7 ± 1.5) cm respectively in control group, the difference between two groups was statistically significant (P < 0.05). The complete patent of the veins was 66.7% in study group and 31.3% in control group, the difference between two groups was significant (P < 0.05). In four cases of the study group, the filters were withdrawn through the original puncture site after the thrombus was completely dissolved. Conclusion: Trans-jugular CDT combined with trans-dorsalis pedis vein thrombolysis is an effective and safe therapeutic technique for the treatment of deep venous thrombosis of the lower extremities, moreover, the filter can be taken back via the original puncture site when the thrombus is completely dissolved. (authors)

  11. Polidocanol versus hypertonic glucose for sclerotherapy treatment of reticular veins of the lower limbs: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bertanha, Matheus; Sobreira, Marcone Lima; Pinheiro Lúcio Filho, Carlos Eduardo; de Oliveira Mariúba, Jamil Victor; Farres Pimenta, Rafael Elias; Jaldin, Rodrigo Gibin; Moroz, Andrei; Moura, Regina; Rollo, Hamilton Almeida; Yoshida, Winston Bonetti

    2014-12-19

    The prevalence of chronic venous disease is high and occurs more frequently in females. According to the clinical, etiological, anatomical, and pathological classification (CEAP) definition, the reticular veins are included in the C1 class and are mainly associated with aesthetic complaints. Several invasive techniques are used for treatment, including mini phlebectomy, laser ablation, and radiofrequency ablation. However, a wide range of sclerosing agents may serve as minimally invasive alternatives, promoting chemical sclerosis of the vein wall. Although this technique is routinely performed around the world, there is no consensus on the most efficacious and safe chemical agent to be used. Inclusion criteria are women between 18 and 69 years old with at least 10 cm long reticular veins in the lower limbs, on the outer side of the leg/thigh. Patients with CEAP 2 to 6, or with allergies, pregnancy, performing breastfeeding, or with any dermatologic or clinical problems will be excluded. Patients with venous ultrasound mapping showing involvement of saphenous trunks and/or a deep venous system will also be excluded. Patients will be randomized into two groups, one receiving 75% pure glucose and the other group receiving 0.2% polidocanol diluted in 70% glucose. Just one limb and one session per patient will be performed. The sclerosing agent volume will not exceed 5 mL. Clinical follow-up will include visits on days 7 and 60, always with photographic documentation. This project aims to enroll 96 patients and subject them to a double-blind treatment after the randomization process. The design is intended to evaluate efficacy through a primary end point and safety through a secondary end point. Forty-eight patients have currently been enrolled. Preliminary results for these patients showed that 25 received treatment, 2 were excluded, and 22 returned after 7 days and showed no greater adverse events. To date, establishing efficacy criteria has not been possible, and no

  12. A profile of lower-limb deep-vein thrombosis: the hidden menace of below-knee DVT

    Energy Technology Data Exchange (ETDEWEB)

    Cowell, G.W. [Department of Clinical Radiology, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); Reid, J.H. [Department of Clinical Radiology, Borders General Hospital, Melrose (United Kingdom); Simpson, A.J. [Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); Murchison, J.T. [Department of Clinical Radiology, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom)]. E-mail: john.murchison@luht.scot.nhs.uk

    2007-09-15

    Aims: To describe the anatomical site and laterality of deep-vein thrombosis (DVT) in symptomatic patients using contrast venography (CV), and to assess age, sex distribution, and accuracy of pre-test clinical suspicion of DVT. Methods: One thousand, five hundred and seventy-two patients undergoing CV because of a clinical suspicion of DVT at a large teaching hospital from October 1995 to March 2003 were prospectively studied. Results: Thrombi were demonstrated in 511 (32.5%) of all CV studies. Isolated, below-knee thrombi were identified in 29.4% of positive studies. There was a left-sided predominance of DVT (ratio 1.24:1) that was most evident in the elderly and in more proximal veins. Conclusion: Almost a third of positive cases were shown to be isolated, below-knee thrombi. These are thrombi that are more difficult to detect by non-invasive means. A left-sided predominance of DVT is evident.

  13. A profile of lower-limb deep-vein thrombosis: the hidden menace of below-knee DVT

    International Nuclear Information System (INIS)

    Cowell, G.W.; Reid, J.H.; Simpson, A.J.; Murchison, J.T.

    2007-01-01

    Aims: To describe the anatomical site and laterality of deep-vein thrombosis (DVT) in symptomatic patients using contrast venography (CV), and to assess age, sex distribution, and accuracy of pre-test clinical suspicion of DVT. Methods: One thousand, five hundred and seventy-two patients undergoing CV because of a clinical suspicion of DVT at a large teaching hospital from October 1995 to March 2003 were prospectively studied. Results: Thrombi were demonstrated in 511 (32.5%) of all CV studies. Isolated, below-knee thrombi were identified in 29.4% of positive studies. There was a left-sided predominance of DVT (ratio 1.24:1) that was most evident in the elderly and in more proximal veins. Conclusion: Almost a third of positive cases were shown to be isolated, below-knee thrombi. These are thrombi that are more difficult to detect by non-invasive means. A left-sided predominance of DVT is evident

  14. Estudo anatômico da veia braquial comum como via de drenagem colateral do membro superior Anatomic study of the common brachial vein as a collateral drainage channel of the upper limb

    Directory of Open Access Journals (Sweden)

    Carlos Adriano Silva dos Santos

    2011-03-01

    Full Text Available CONTEXTO: Traumatismos ou tromboses que possam evoluir com alterações da drenagem venosa do membro superior, dependendo do território interrompido, podem ter como mecanismo compensatório uma via colateral de drenagem sem que haja prejuízo para o retorno venoso desse membro. A veia braquial comum apresenta-se como uma alternativa plausível e pouco conhecida. OBJETIVO: Descrever a anatomia da veia braquial comum como via de drenagem colateral no membro superior. MÉTODOS: Utilizamos 30 cadáveres do sexo masculino, cujos membros superiores estavam articulados ao tronco, não importando a raça, formolizados e mantidos em conservação com solução de formol a 10%. Utilizamos como critérios de exclusão cadáveres com um dos membros desarticulado ou alterações deformantes em topografia das estruturas estudadas. RESULTADOS: A veia braquial comum esteve presente em 73% (22/30 dos cadáveres estudados, sendo que em 18% (04/22 dos casos drenou para a veia basílica no seguimento proximal do braço e em 82% (18/22, para a veia axilar. CONCLUSÃO: A veia braquial comum está frequentemente presente e, na maior parte das vezes, desemboca na veia axilar.BACKGROUND: Trauma and thrombosis that can result in changes in the venous drainage of the upper limb, depending on the vascular territory interrupted, may have as a compensatory mechanism a collateral drainage channel that prevents damage to the venous return of that limb. The common brachial vein is a plausible and little known collateral channel for this purpose. OBJECTIVE: To describe the anatomy of the common brachial vein as a collateral drainage channel of the upper limb. METHODS: We have dissected 30 cadavers of people of different races, whose upper limbs were articulated to the trunk and preserved in a 10% formaldehyde solution. The exclusion criteria were disarticulated limbs or deformities in the topography of the studied structures. RESULTS: The common brachial vein was present in 73

  15. Midterm Outcomes From a Pilot Study of Percutaneous Deep Vein Arterialization for the Treatment of No-Option Critical Limb Ischemia.

    Science.gov (United States)

    Kum, Steven; Tan, Yih Kai; Schreve, Michiel A; Ferraresi, Roberto; Varcoe, Ramon L; Schmidt, Andrej; Scheinert, Dierk; Mustapha, Jihad A; Lim, Darryl M; Ho, Derek; Tang, Tjun Y; Alexandrescu, Vlad-Adrian; Mutirangura, Pramook

    2017-10-01

    To report the initial clinical experience with percutaneous deep vein arterialization (PDVA) to treat critical limb ischemia (CLI) via the creation of an arteriovenous fistula. Seven patients (median age 85 years; 5 women) with CLI and no traditional endovascular or surgical revascularization options (no-option CLI) were recruited in a pilot study to determine the safety of PDVA. All patients were diabetic; 4 had Rutherford category 6 ischemia. Six were classified at high risk of amputation based on the Society for Vascular Surgery WIfI (wound, ischemia, and foot infection) classification. The primary safety endpoints were major adverse limb events and major adverse coronary events through 30 days and serious adverse events through 6 months. Secondary objectives included clinical efficacy based on outcome measures including thermal measurement, transcutaneous partial pressure of oxygen (TcPO 2 ), clinical improvement at 6 months, and wound healing. The primary safety endpoints were achieved in 100% of patients, with no deaths, above-the-ankle amputations, or major reinterventions at 30 days. The technical success rate was 100%. Two myocardial infarctions occurred within 30 days, each with minor clinical consequences. All patients demonstrated symptomatic improvement with formation of granulation tissue, resolution of rest pain, or both. Complete wound healing was achieved in 4 of 7 patients and 5 of 7 patients at 6 and 12 months, respectively, with a median healing time of 4.6 months (95% confidence interval 84-192). Median postprocedure peak TcPO 2 was 61 mm Hg compared to a preprocedure level of 8 mm Hg (p=0.046). At the time of wound healing, 4 of 5 of patients achieved TcPO 2 levels of >40 mm Hg. There were 2 major amputations, 1 above the knee after PDVA thrombosis and 1 below the knee for infection. Three patients died of causes unrelated to the procedure or study device at 6, 7, and 8 months, respectively. Limb salvage was 71% at 12 months. PDVA is an

  16. A 1470-nm laser combined with foam sclerotherapy in day surgery: a better choice for lower limb varicose veins.

    Science.gov (United States)

    Zhang, Xing; Wang, Xin; Gao, Cheng; Qin, Jinbao; Zhao, Haiguang; Li, Weimin; Lu, Xinwu

    2018-04-23

    Day surgery is being more and more adopted by clinicians. Higher wavelength lasers give patients better experience than lower wavelength lasers, which makes it more suitable for day surgery. This study compares the short- and mid-term efficacy, postoperative morbidity, and patient satisfaction of "1470-nm endovenous laser ablation (EVLA) combining foam sclerotherapy in day surgery" with "810-nm EVLA with high ligation combining foam sclerotherapy in hospital surgery" on great saphenous vein (GSV) insufficiency postoperatively. A single-institution historical cohort study of 194 patients was performed in Shanghai Ninth People's Hospital, China. Ninety-seven patients received 1470-nm EVLA combining foam sclerotherapy in day surgery ("1470-nm group"), and 97 patients received 810-nm EVLA with high ligation combining foam sclerotherapy in hospital surgery recommended by guidelines ("810-nm group"). No significant difference was found between the 1470-nm group and the 810-nm group in terms of GSV occlusion rate (both 100%), complication rate, and recurrence rate (8.2 vs. 11.3%) during the period of 1-12 months after surgery. Serious complications in the 1470-nm group and 810-nm group were 0 and 1.0%. Minor complications in the 1470-nm group and 810-nm group were ecchymosis at 20.6 and 18.6%, edema at 69.1 and 63.9%, and paresthesia around ankle at 0 and 3.1%, respectively. Advantage of the 1470-nm group over the 810-nm group was statistically significant considering the patient perioperative comfort and economic cost. Treatment of 1470-nm EVLA combining foam sclerotherapy in day surgery has similar efficacy as the 810-nm EVLA with high ligation combining foam sclerotherapy in hospital surgery in GSV insufficiency and is more comfortable with less incision, hospitalization procedure, and medical costs. It may be a new option for patients who are afraid or unable to be hospitalized.

  17. Veias soleares: bases anatômicas e seu papel na origem da trombose venosa profunda em membro inferior Soleus veins: anatomic basis and their role in the origin of deep venous lower limb thrombosis

    Directory of Open Access Journals (Sweden)

    Carlos Miguel Gomes Sequeira

    2007-08-01

    Full Text Available OBJETIVO: Estudar o número, a setorização e a terminação das veias soleares. MÉTODOS: Em 100 pernas de 50 cadáveres, excluídos aqueles com alterações congênitas ou adquiridas dos membros inferiores, foram realizadas, a fresco, na região crural posterior, dissecções anatômicas minuciosas, estratigráficas. Após o rebatimento da pele, foram realizadas a individualização das veias superficiais e perfurantes, rebatimento da tela subcutânea e da fáscia, individualização e rebatimento dos músculos gastrocnêmio e plantar, desinserção tibial do músculo sóleo, individualização das veias soleares e o estudo morfométrico. A região foi dividida em seis setores: súpero-medial, súpero-lateral, médio-medial, médio-lateral, ínfero-medial e ínfero-lateral. No estudo estatístico utilizaram-se os testes não-paramétricos Wilcoxon e Friedman. RESULTADOS: Foram encontradas 4.679 veias soleares. O setor com maior número de veias soleares foi o súpero-lateral com 1.529 veias (32,7%, seguido do médio-medial com 1.256 veias (26,8% e do médio-lateral com 975 veias (20,8%. As terminações ocorreram em veias comunicantes (1.207 veias - 25,8%, veias tibiais posteriores (964 veias - 20,6%, veias fibulares (709 veias - 15,2% e em mais 32 tipos (1799 veias - 38,4%. CONCLUSÃO: A drenagem venosa do músculo sóleo é realizada por um grande número de veias soleares, freqüentemente localizadas nos setores súpero-lateral, médio-medial e médio-lateral, terminando comumente em veias tibiais posteriores e fibulares e, em veias comunicantes.OBJECTIVE: Study of the number, sectorization and termination of the soleus veins. METHODS: Meticulous, stratigraphical, anatomical dissections were carried out in the posterior crural region of 100 legs of 50 fresh cadavers. Those belonging to subjects with congenital or acquired pathologies in the lower limbs were disregarded. After the skin was reflected on both sides, dissection of superficial

  18. Factors affecting optimal linear endovenous energy density for endovenous laser ablation in incompetent lower limb truncal veins - A review of the clinical evidence.

    Science.gov (United States)

    Cowpland, Christine A; Cleese, Amy L; Whiteley, Mark S

    2017-06-01

    Objectives The objective is to identify the factors that affect the optimal linear endovenous energy density (LEED) to ablate incompetent truncal veins. Methods We performed a literature review of clinical studies, which reported truncal vein ablation rates and LEED. A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) flow diagram documents the search strategy. We analysed 13 clinical papers which fulfilled the criteria to be able to compare results of great saphenous vein occlusion as defined by venous duplex ultrasound, with the LEED used in the treatment. Results Evidence suggests that the optimal LEED for endovenous laser ablation of the great saphenous vein is >80 J/cm and water might have a lower optimal LEED. A LEED 80 J/cm and <95 J/cm based on current evidence for shorter wavelength lasers. There is evidence that longer wavelength lasers may be effective at LEEDs of <85 J/cm.

  19. Pelvic Vein Embolisation in the Management of Varicose Veins

    International Nuclear Information System (INIS)

    Ratnam, Lakshmi A.; Marsh, Petra; Holdstock, Judy M.; Harrison, Charmaine S.; Hussain, Fuad F.; Whiteley, Mark S.; Lopez, Anthony

    2008-01-01

    Pelvic vein incompetence is common in patients with atypical varicose veins, contributing to their recurrence after surgery. Therefore, refluxing pelvic veins should be identified and treated. We present our experience with pelvic vein embolisation in patients presenting with varicose veins. Patients presenting with varicose veins with a duplex-proven contribution from perivulval veins undergo transvaginal duplex sonography (TVUS) to identify refluxing pelvic veins. Those with positive scans undergo embolisation before surgical treatment of their lower limb varicose veins. A total of 218 women (mean age of 46.3 years) were treated. Parity was documented in the first 60 patients, of whom 47 (78.3%) were multiparous, 11 (18.3%) had had one previous pregnancy, and 2 (3.3%) were nulliparous. The left ovarian vein was embolised in 78%, the right internal iliac in 64.7%, the left internal iliac in 56.4%, and the right ovarian vein in 42.2% of patients. At follow-up TVUS, mild reflux only was seen in 16, marked persistent reflux in 6, and new reflux in 3 patients. These 9 women underwent successful repeat embolisation. Two patients experienced pulmonary embolisation of the coils, of whom 1 was asymptomatic and 1 was successfully retrieved; 1 patient had a misplaced coil protruding into the common femoral vein; and 1 patient had perineal thrombophlebitis. The results of our study showed that pelvic venous embolisation by way of a transjugular approach is a safe and effective technique in the treatment of pelvic vein reflux.

  20. Improving the Outcome of Vein Grafts: Should Vascular Surgeons Turn Veins into Arteries?

    OpenAIRE

    Isaji, Toshihiko; Hashimoto, Takuya; Yamamoto, Kota; Santana, Jeans M.; Yatsula, Bogdan; Hu, Haidi; Bai, Hualong; Jianming, Guo; Kudze, Tambudzai; Nishibe, Toshiya; Dardik, Alan

    2017-01-01

    Autogenous vein grafts remain the gold standard conduit for arterial bypass, particularly for the treatment of critical limb ischemia. Vein graft adaptation to the arterial environment, i.e., adequate dilation and wall thickening, contributes to the superior performance of vein grafts. However, abnormal venous wall remodeling with excessive neointimal hyperplasia commonly causes vein graft failure. Since the PREVENT trials failed to improve vein graft outcomes, new strategies focus on the ada...

  1. Polidocanol versus hypertonic glucose for sclerotherapy treatment of reticular veins of the lower limbs: study protocol for a randomized controlled trial

    OpenAIRE

    Bertanha, Matheus [UNESP; Sobreira, Marcone Lima [UNESP; Lúcio Filho, Carlos Eduardo Pinheiro [UNESP; Mariúba, Jamil Victor de Oliveira [UNESP; Pimenta, Rafael Elias Farres [UNESP; Jaldin, Rodrigo Gibin [UNESP; Moroz, Andrei [UNESP; Moura, Regina [UNESP; Rollo, Hamilton Almeida [UNESP; Yoshida, Winston Bonetti [UNESP

    2014-01-01

    Background The prevalence of chronic venous disease is high and occurs more frequently in females. According to the clinical, etiological, anatomical, and pathological classification (CEAP) definition, the reticular veins are included in the C1 class and are mainly associated with aesthetic complaints. Several invasive techniques are used for treatment, including mini phlebectomy, laser ablation, and radiofrequency ablation. However, a wide range of sclerosing agents may serve as minimally in...

  2. A Morphological Insight of the Femoral Vein

    Directory of Open Access Journals (Sweden)

    Ferreira AH

    2015-10-01

    Full Text Available A total of 13 cadavers (12 men and 1 women of different age group were used for the study with the purpose to determine the prevalence of femoral vein duplication. Lower limb regions (26 sides were carefully dissected as per the standard dissection procedure. Femoral vein (unitruncular was found in 96.15% of specimen. Bitruncular configurations (total bifidity was found in a male cadaver of 75 years of age (3.85%. In the right lower limb, 6.5 cms below the inguinal ligament the femoral vein - lateral ramus received the lateral circumflex femoral vein, and the medial circumflex femoral vein, and the lateral and medial ramii formed a common venous trunk. Knowledge of the truncular venous variations is important to recognize and avoid potential errors in diagnosis of deep venous thrombosis of the femoral vein, in the case of an occluded duplicated trunk.

  3. Derivação com veias de membro superior após trombólise de aneurisma de artéria poplítea: alternativa para salvamento de membro Arm vein bypass after popliteal artery aneurysm thrombolysis: an alternative for limb salvage

    Directory of Open Access Journals (Sweden)

    João Antonio Corrêa

    2007-06-01

    Full Text Available Os autores relatam um caso de aneurisma de artéria poplítea trombosado em que se realizou fibrinólise com sucesso na fase aguda. Foram utilizadas veias de braço para realização do enxerto e exclusão do aneurisma, pois o paciente havia sido previamente submetido à safenectomia bilateral e revascularização do miocárdio com as veias do outro braço. Apesar das dificuldades, o salvamento do membro foi alcançado.The authors report a case of a thrombosed popliteal artery aneurysm successfully treated by fibrinolysis in its acute stage. Arm veins were used to perform a bypass and aneurysm exclusion, since the patient had previously been submitted to bilateral saphenous vein stripping and myocardial revascularization using the veins of the other arm. Despite the difficulties, limb salvage was achieved.

  4. Interposition vein cuffs.

    Science.gov (United States)

    Harris, P; Da Silva, T; How, T

    1996-01-01

    A vein cuff interposed at the distal anastomosis between a prosthetic vascular graft and a recipient infrageniculate artery improves the chances of continued patency of the graft, at least in the short and medium term. The mode of effect appears to be suppression or modification of anastomotic myointimal hyperplasia (MIH). In the event of graft failure the recipient artery and run-off vessels remain free from MIH and their patency is preserved thereby improving the prospects for further vascular reconstruction and limb salvage. The mechanisms by which interposition vein cuffs might modulate MIH are reviewed. Experimental evidence is described to show that the geometry of a cuffed anastomosis promotes a characteristic haemodynamic flow structure with a stable vortex. It is suggested that this vortex exerts greater shear stress upon the wall of the artery than the normal laminar flow observed in conventional anastomoses. High shear stress is known to inhibit MIH.

  5. Sclerotherapy of Varicose Veins and Spider Veins

    Science.gov (United States)

    ... Index A-Z Sclerotherapy of Varicose Veins and Spider Veins Sclerotherapy uses injections from a very fine, ... Sclerotherapy? What is Sclerotherapy of Varicose Veins and Spider Veins? Sclerotherapy is a minimally invasive treatment used ...

  6. Interventional treatment of iliac vein compression syndrome

    International Nuclear Information System (INIS)

    Li Xiaoqiang; Zhou Weiming; Nie Zhonglin; Yu Chaowen

    2002-01-01

    Objective: To explore the clinical significance of interventional treatment of iliac vein compression syndrome (IVCS). Methods: Percutaneous transluminal angioplasty (PTA) was performed in 40 cases. Thirty-three cases underwent endovascular stent implantation and 27 cases underwent second-stage left saphenous vein ligation and stripping and the valves of left femoral veins narrowing. Thirty-one cases were followed-up postoperatively and the duration was 6-66 months (mean 28 months). Results: The dilation of iliac veins was successful in 36 cases and there were god efficacy in all patients when they discharged from hospital. Followed-up during post-operation, all the limbs ulcers were cured and varicose veins disappeared. The skin pigmentation disappeared in 17 of 19 cases and markedly relieved in 2 cases. Left lower limb swelling disappeared in 15 of 17 cases and relieved in 2 cases. Conclusion: There is good efficacy in the interventional treatment of left iliac vein lesions, but second-stage procedures should be performed in secondary lesions of saphenous veins and valves of femoral veins

  7. Evaluation of pelvic varicose veins using color Doppler ultrasound: comparison of results obtained with ultrasound of the lower limbs, transvaginal ultrasound, and phlebography Avaliação de varizes pélvicas por Doppler colorido: comparação dos resultados obtidos com ultrassom dos membros inferiores, ultrassom transvaginal e flebografia

    Directory of Open Access Journals (Sweden)

    Fanilda Souto Barros

    2010-06-01

    Full Text Available Introduction: Pelvic varicose veins, one of the main causes of chronic pelvic pain and dyspareunia, are an important source of reflux for lower limb varicose veins, especially in recurrent cases. Color Doppler ultrasound of the lower limbs and transvaginal ultrasound are the noninvasive diagnostic methods most commonly used to assess pelvic venous insufficiency, whereas phlebography is still considered as the gold standard. Objectives: To determine the prevalence of lower limb varicose veins originating from the pelvis in a group of female patients and to determine the agreement between results obtained via color Doppler ultrasound of the lower limbs, transvaginal ultrasound, and phlebography. Methods: The sample comprised female patients referred to a vascular laboratory for lower limb screening. Patients diagnosed with deep venous thrombosis were excluded. Data analysis included kappa coefficient of agreement, McNemar's test, sensitivity and specificity values. Results: Of a total of 1,020 patients, 124 (12.2% had findings compatible with reflux of pelvic origin. Among these patients, 51 (41.2% were recurrent cases. A total of 249 were submitted to transvaginal ultrasound. There was significant agreement between lower limb ultrasonographic findings and transvaginal findings. Phlebography was performed in 54 patients. The comparison between transvaginal ultrasound and phlebography was associated with a 96.2% sensitivity and 100% specificity. Conclusions: The authors draw attention to the relatively high prevalence of lower limb varicose veins originating from the pelvis, suggesting an important but underdiagnosed cause of recurrent varicose veins.Introdução: AS VARIZES Pélvicas, uma das principais causas de dor pélvica crônica e dispareunia, são uma importante fonte de refluxo para as varizes dos membros inferiores, especialmente em casos recorrentes. O Doppler colorido dos membros inferiores e o ultrassom transvaginal são os m

  8. Varicose vein - noninvasive treatment

    Science.gov (United States)

    ... spider veins. These are small varicose veins. Salt water (saline) or a chemical solution is injected into the varicose vein. The vein will harden and then disappear. Laser treatment can be used on the surface of the skin. Small bursts ...

  9. Varicose vein stripping

    Science.gov (United States)

    ... stripping; Venous reflux - vein stripping; Venous ulcer - veins Patient Instructions Surgical wound care - open Varicose veins - what to ask your doctor Images Circulatory system References American Family Physician. Management of varicose veins. www.aafp.org/afp/2008/ ...

  10. What Are Varicose Veins?

    Science.gov (United States)

    ... Leer en español What Is Varicose (VAR-i-kos) veins are swollen, twisted veins that you can ... TA-ze-uhs), spider veins, varicoceles (VAR-i-ko-seals), and other vein problems. Telangiectasias Telangiectasias are ...

  11. The Incidence of Giacomini Vein and Its Association with Lower Extremity venous Insufficiency: An Ultrasonographic Study

    International Nuclear Information System (INIS)

    Park, Soon Chan; Kwon, Se Hwan; Oh, Joo Hyeong; Ryu, Kyung Nam; Ahn, Hyung Joon; Park, Ho Chul

    2009-01-01

    We wanted to evaluate the incidence of Giacomini vein and its association with lower extremity venous insufficiency by performing US. From September 2006 to July 2007, 173 patients (58 males and 115 females, mean age: 52.7 years, age range: 22-72 years) who had been diagnosed with unilateral/bilateral varicose veins or telangiectasias were evaluated with duplex Doppler ultrasonography. The presence of Giacomini vein, superficial/deep vein reflux, the anatomical sites of the venous reflux and the abnormal perforating veins was investigated in 346 legs. Giacomini veins were found in 33 limbs (9.5%) of 21 patients (12.1%). Bilateral Giacomini veins were found in 12 patients. Of the 33 limbs that had Giacomini veins, 20 limbs had great saphenous vein (GSV) reflux and 4 limbs had small saphenous vein (SSV) reflux. The patients with Giacomini veins were classified into two groups according to the presence of Giacomini vein. There was no significant difference of the GSV reflux (p = 0.155), the SSV reflux (p = 0.760) and the mean velocity of the GSV reflux or the SSV reflux (p = 0.685, p = 0.431, respectively) between the two groups. Our results indicated that Giacomini vein is not associated with either GSV or SSV reflux, and this is contrary to conventional belief

  12. Focus on Varicose Veins

    Science.gov (United States)

    ... because the valves of the veins no longer work. Under the pressure of gravity these veins can continue to expand and, in ... and to determine whether the vein valves are work- ing properly or have ... painless. How are varicose veins treated? Varicose veins are always ...

  13. Varicose Veins - Multiple Languages

    Science.gov (United States)

    ... Concerns and Discomforts of Pregnancy: Varicose Veins - English MP3 Concerns and Discomforts of Pregnancy: Varicose Veins - 简体中文 (Chinese, Simplified (Mandarin dialect)) MP3 Concerns and Discomforts of Pregnancy: Varicose Veins - English ...

  14. Spider Vein Removal

    Science.gov (United States)

    Spider veins: How are they removed? I have spider veins on my legs. What options are available ... M.D. Several options are available to remove spider veins — thin red lines or weblike networks of ...

  15. Update of endovenous treatment modalities for insufficient saphenous veins-A review of literature

    NARCIS (Netherlands)

    van Eekeren, Ramon R. J. P.; Boersma, Doeke; de Vries, Jean-Paul P. M.; Zeebregts, Clark J.; Reijnen, Michel M. P. J.

    Lower-limb venous insufficiency resulting from saphenous vein incompetence is a common disorder, increasing with age. For decades, surgical stripping of the great saphenous vein has been the gold standard in varicose vein treatment. The desire to optimize outcomes of treatment and reduce surgical

  16. Relativistic hydrodynamics

    CERN Document Server

    Luciano, Rezzolla

    2013-01-01

    Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...

  17. Recanalization after acute deep vein thrombosis

    Directory of Open Access Journals (Sweden)

    Gustavo Mucoucah Sampaio Brandao

    2013-12-01

    Full Text Available The process of recanalization of the veins of the lower limbs after an episode of acute deep venous thrombosis is part of the natural evolution of the remodeling of the venous thrombus in patients on anticoagulation with heparin and vitamin K inhibitors. This remodeling involves the complex process of adhesion of thrombus to the wall of the vein, the inflammatory response of the vessel wall leading to organization and subsequent contraction of the thrombus, neovascularization and spontaneous lysis of areas within the thrombus. The occurrence of spontaneous arterial flow in recanalized thrombosed veins has been described as secondary to neovascularization and is characterized by the development of flow patterns characteristic of arteriovenous fistulae that can be identified by color duplex scanning. In this review, we discuss some controversial aspects of the natural history of deep vein thrombosis to provide a better understanding of its course and its impact on venous disease.

  18. Hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the rheological models and the equations of lubrication. It also presents the numerical approaches used to solve the above equations by finite differences, finite volumes and finite elements methods.

  19. Hydrodynamic Lubrication

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 9. Hydrodynamic Lubrication Experiment with 'Floating' Drops. Jaywant H Arakeri K R Sreenivas. General Article Volume 1 Issue 9 September 1996 pp 51-58. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Theoretical hydrodynamics

    CERN Document Server

    Milne-Thomson, L M

    2011-01-01

    This classic exposition of the mathematical theory of fluid motion is applicable to both hydrodynamics and aerodynamics. Based on vector methods and notation with their natural consequence in two dimensions - the complex variable - it offers more than 600 exercises and nearly 400 diagrams. Prerequisites include a knowledge of elementary calculus. 1968 edition.

  1. Hydrodynamic disperser

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, A.I.; Chernov, V.S.; Prokopov, L.I.; Proselkov, Yu.M.; Tikhonov, Yu.P.

    1980-01-15

    A hydrodynamic disperser is suggested which contains a housing, slit nozzles installed on a circular base arranged opposite from each other, resonators secured opposite the nozzle and outlet sleeve. In order to improve the effectiveness of dispersion by throttling the flow, each resonator is made in the form of a crimped plate with crimpings that decrease in height in a direction towards the nozzle.

  2. Portal Vein Thrombosis

    Directory of Open Access Journals (Sweden)

    Hakan Demirci

    2016-01-01

    Full Text Available Portal vein thrombosis is an important cause of presinusoidal portal hypertension. Portal vein thrombosis commonly occurs in patient with cirrhosis, malignancy and prothrombotic states. Patients with acute portal vein thrombosis have immediate onset. Patients with chronic portal vein thrombosis have developed portal hypertension and cavernous portal transformation. Portal vein thrombosis is diagnosed with doppler ultrasound, computed tomography and magnetic resonance imaging. Therapy with low molecular weight heparin achieves recanalization in more than half of acute cases.

  3. Limb anomalies

    DEFF Research Database (Denmark)

    Gurrieri, Fiorella; Kjær, Klaus Wilbrandt; Sangiorgi, Eugenio

    2002-01-01

    of limb development has been conserved for more than 300 millions years, with all the necessary adaptive modifications occurring throughout evolution, we also take into consideration the evolutionary aspects of limb development in terms of genetic repertoire, molecular pathways, and morphogenetic events....

  4. PTFE bypass to below-knee arteries: distal vein collar or not? A prospective randomised multicentre study

    DEFF Research Database (Denmark)

    Lundgren, Fredrik; Bergqvist, David; Norgren, Lars

    2010-01-01

    Patency and limb salvage after synthetic bypass to the arteries below-knee are inferior to that which can be achieved with autologous vein. Use of a vein collar at the distal anastomosis has been suggested to improve patency and limb salvage, a problem that is analysed in this randomised clinical...

  5. Limb Loss

    Science.gov (United States)

    ... in amputation. Injuries, including from traffic accidents and military combat Cancer Birth defects Some amputees have phantom pain, which is the feeling of pain in the missing limb. Other physical problems include surgical complications and skin problems, if you ...

  6. Supernova hydrodynamics

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1981-01-01

    The explosion of a star supernova occurs at the end of its evolution when the nuclear fuel in its core is almost, or completely, consumed. The star may explode due to a small residual thermonuclear detonation, type I SN or it may collapse, type I and type II SN leaving a neutron star remnant. The type I progenitor should be thought to be an old accreting white dwarf, 1.4 M/sub theta/, with a close companion star. A type II SN is thought to be a massive young star 6 to 10 M/sub theta/. The mechanism of explosion is still a challenge to our ability to model the most extreme conditions of matter and hydrodynamics that occur presently and excessively in the universe. 39 references

  7. Submarine hydrodynamics

    CERN Document Server

    Renilson, Martin

    2015-01-01

    This book adopts a practical approach and presents recent research together with applications in real submarine design and operation. Topics covered include hydrostatics, manoeuvring, resistance and propulsion of submarines. The author briefly reviews basic concepts in ship hydrodynamics and goes on to show how they are applied to submarines, including a look at the use of physical model experiments. The issues associated with manoeuvring in both the horizontal and vertical planes are explained, and readers will discover suggested criteria for stability, along with rudder and hydroplane effectiveness. The book includes a section on appendage design which includes information on sail design, different arrangements of bow planes and alternative stern configurations. Other themes explored in this book include hydro-acoustic performance, the components of resistance and the effect of hull shape. Readers will value the author’s applied experience as well as the empirical expressions that are presented for use a...

  8. Physical hydrodynamics

    CERN Document Server

    Guyon, Etienne; Petit, Luc; Mitescu, Catalin D

    2015-01-01

    This new edition is an enriched version of the textbook of fluid dynamics published more than 10 years ago. It retains the same physically oriented pedagogical perspective. This book emphasizes, as in the first edition, experimental inductive approaches and relies on the study of the mechanisms at play and on dimensional analysis rather than more formal approaches found in many classical textbooks in the field. The need for a completely new version also originated from the increase, over the last few decades, of the cross-overs between the mechanical and physical approaches, as is visible in international meetings and joint projects. Hydrodynamics is more widely linked today to other fields of experimental sciences: materials, environment, life sciences and earth sciences, as well as engineering sciences.

  9. Introduction to hydrodynamics

    International Nuclear Information System (INIS)

    Wilkins, M.L.

    1979-01-01

    Various aspects of hydrodynamics and elastic--plastic flow are introduced for the purpose of defining hydrodynamic terms and explaining what some of the important hydrodynamic concepts are. The first part covers hydrodynamic theory; and discussed fundamental hydrodynamic equations, discontinuities, and shock, detonation, and elastic--plastic waves. The second part deals with applications of hydrodynamic theory to material equations of state, spall, Taylor instabilities, and detonation pressure measurements

  10. Edema de membro inferior secundário a exérese de veia safena magna para utilização como enxerto na revascularização do miocárdio Lower limb edema after great saphenous vein harvesting to be used as graft in myocardial revascularization

    Directory of Open Access Journals (Sweden)

    Cleusa Ema Quilici Belczak

    2009-03-01

    Full Text Available CONTEXTO: A revascularização do miocárdio utilizando-se a veia safena magna ainda é procedimento cirúrgico bastante realizado na atualidade. O edema que surge no membro inferior operado causa grande desconforto e necessita ser melhor estudado. OBJETIVOS: Caracterizar o edema de membro inferior secundário a exérese da veia safena magna pela técnica de incisões escalonadas para sua utilização como enxerto venoso na revascularização do miocárdio. MÉTODOS: Foram selecionados aleatoriamente 44 indivíduos submetidos a exérese de veia safena magna para revascularização miocárdica há mais de 3 meses. Excluíram-se fatores que pudessem interferir na formação de edema dos membros inferiores. Foram avaliados por volumetria e perimetria maleolares ambos os membros inferiores. Considerou-se como presença de edema significativo a diferença de volume maior que 50 mL e maior de 2 cm em relação ao membro não-operado. Para a análise estatística foram empregados o teste do qui-quadrado, teste exato de Fisher, teste t de Student e o teste de McNemar. O nível de significância adotado foi de 5% (a = 0,05. RESULTADOS: Encontraram-se diferenças estatisticamente significativas (p BACKGROUND: Myocardial revascularization using the great saphenous vein is still a very common surgical procedure. The edema that occurs in the operated leg causes much discomfort and requires further studies. OBJECTIVES: To describe lower limb edema secondary to great saphenous vein harvesting using the bridge technique for use as venous graft in myocardial revascularization. METHODS: Forty-four individuals previously submitted to great saphenous vein harvesting for myocardial revascularization more than 3 months before were randomly selected. Patients with factors that might interfere with formation of lower limb edema were excluded. Both operated and non-operated legs were evaluated by volumetry and perimetry of the malleolar region. Differences greater than

  11. Thermo-hydrodynamic lubrication in hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the thermo-hydrodynamic and the thermo-elasto-hydrodynamic lubrication. The algorithms are methodically detailed and each section is thoroughly illustrated.

  12. Animal Model of Acute Deep Vein Thrombosis

    International Nuclear Information System (INIS)

    Roy, Sumit; Laerum, Frode; Brosstad, Frank; Kvernebo, Knut; Sakariassen, Kjell S.

    1998-01-01

    Purpose: To develop an animal model of acute deep vein thrombosis (DVT). Methods: In part I of the study nine juvenile domestic pigs were used. Each external iliac vein was transluminally occluded with a balloon catheter. Thrombin was infused through a microcatheter in one leg according to one of the following protocols: (1) intraarterial (IA): 1250 U at 25 U/min in the common femoral artery (n= 3); (2) intravenous (IV): 5000 U in the popliteal vein at 500 U/min (n= 3), or at 100 U/min (n= 3). Saline was administered in the opposite leg. After the animals were killed, the mass of thrombus in the iliofemoral veins was measured. The pudendoepiploic (PEV), profunda femoris (PF), and popliteal veins (PV) were examined. Thrombosis in the tributaries of the superficial femoral vein (SFVt) was graded according to a three-point scale (0, +, ++). In part II of the study IV administration was further investigated in nine pigs using the following three regimens with 1000 U at 25 U/min serving as the control: (1) 1000 U at 100 U/min, (2) 250 U at 25 U/min, (3) 250 U at 6.25 U/min. Results: All animals survived. In part I median thrombus mass in the test limbs was 1.40 g as compared with 0.25 g in the controls (p= 0.01). PEV, PFV and PV were thrombosed in all limbs infused with thrombin. IV infusion was more effective in inducing thrombosis in both the parent veins (mass 1.32-1.78 g) and SVFt (++ in 4 of 6 legs), as compared with IA infusion (mass 0.0-1.16 g; SFVt ++ in 1 of 3 legs). In part II thrombus mass in axial veins ranged from 1.23 to 2.86 g, and showed no relationship with the dose of thrombin or the rate of infusion. Tributary thrombosis was less extensive with 250 U at 25 U/min than with the other regimens. Conclusion: Slow distal intravenous thrombin infusion in the hind legs of pigs combined with proximal venous occlusion induces thrombosis in the leg veins that closely resembles clinical DVT in distribution

  13. Limb myokymia

    International Nuclear Information System (INIS)

    Albers, J.W.; Allen, A.A.; Bastron, J.A.; Daube, J.R.

    1981-01-01

    Thirty-eight patients with myokymic discharges localized to limb muscles on needle electromyography had various neurologic lesions, both acute and chronic. Of the 38 patients, 27 had had previous radiation therapy and the clinical diagnosis of radiation-induced plexopathy, myelopathy, or both. For the remaining 11 patients, the diagnoses included multiple sclerosis, inflammatory polyradiculoneuropathy, ischemic neuropathy, inflammatory myopathy, and chronic disorders of the spinal cord and peripheral nerves. The clinical presentations and results of local ischemia, peripheral nerve block, and percutaneous stimulation suggest that most limb myokymic discharges arise focally at the site of a chronic peripheral nerve lesion

  14. Hydrodynamic dispersion

    International Nuclear Information System (INIS)

    Pryce, M.H.L.

    1985-01-01

    A dominant mechanism contributing to hydrodynamic dispersion in fluid flow through rocks is variation of travel speeds within the channels carrying the fluid, whether these be interstices between grains, in granular rocks, or cracks in fractured crystalline rocks. The complex interconnections of the channels ensure a mixing of those parts of the fluid which travel more slowly and those which travel faster. On a macroscopic scale this can be treated statistically in terms of the distribution of times taken by a particle of fluid to move from one surface of constant hydraulic potential to another, lower, potential. The distributions in the individual channels are such that very long travel times make a very important contribution. Indeed, while the mean travel time is related to distance by a well-defined transport speed, the mean square is effectively infinite. This results in an asymmetrical plume which differs markedly from a gaussian shape. The distribution of microscopic travel times is related to the distribution of apertures in the interstices, or in the microcracks, which in turn are affected in a complex way by the stresses acting on the rock matrix

  15. Management of reticular veins and telangiectases.

    Science.gov (United States)

    Smith, Philip Coleridge

    2015-11-01

    To review the literature related to the management of reticular varices and telangiectases of the lower limbs to provide guidance on the treatment of these veins. Very few randomised clinical trials are available in this field. A European Guideline has been published on the treatment of reticular varices and telangiectases, which is largely based on the opinion of experts. Older accounts written by individual phlebologists contain extensive advice from their own practice, which is valuable in identifying effective methods of sclerotherapy. All accounts indicate that a history should be taken combined with a clinical and ultrasound examination to establish the full extent of the venous disease. Sclerotherapy is commenced by injecting the larger veins first of all, usually the reticular varices. Later in the same session or in subsequent sessions, telangiectases can be treated by direct injection. Following treatment, the application of class 2 compression stockings for a period of up to three weeks is beneficial but not used universally by all phlebologists. Further sessions can follow at intervals of 2-8 weeks in which small residual veins are treated. Resistant veins can be managed by ultrasound-guided injection of underlying perforating veins and varices. Other treatments including RF diathermy and laser ablation of telangiectases have very limited efficacy in this condition. Sclerotherapy, when used with the correct technique, is the most effective method for the management of reticular varices and telangiectases. © The Author(s) 2015.

  16. Chromatin Hydrodynamics

    Science.gov (United States)

    Bruinsma, Robijn; Grosberg, Alexander Y.; Rabin, Yitzhak; Zidovska, Alexandra

    2014-01-01

    Following recent observations of large scale correlated motion of chromatin inside the nuclei of live differentiated cells, we present a hydrodynamic theory—the two-fluid model—in which the content of a nucleus is described as a chromatin solution with the nucleoplasm playing the role of the solvent and the chromatin fiber that of a solute. This system is subject to both passive thermal fluctuations and active scalar and vector events that are associated with free energy consumption, such as ATP hydrolysis. Scalar events drive the longitudinal viscoelastic modes (where the chromatin fiber moves relative to the solvent) while vector events generate the transverse modes (where the chromatin fiber moves together with the solvent). Using linear response methods, we derive explicit expressions for the response functions that connect the chromatin density and velocity correlation functions to the corresponding correlation functions of the active sources and the complex viscoelastic moduli of the chromatin solution. We then derive general expressions for the flow spectral density of the chromatin velocity field. We use the theory to analyze experimental results recently obtained by one of the present authors and her co-workers. We find that the time dependence of the experimental data for both native and ATP-depleted chromatin can be well-fitted using a simple model—the Maxwell fluid—for the complex modulus, although there is some discrepancy in terms of the wavevector dependence. Thermal fluctuations of ATP-depleted cells are predominantly longitudinal. ATP-active cells exhibit intense transverse long wavelength velocity fluctuations driven by force dipoles. Fluctuations with wavenumbers larger than a few inverse microns are dominated by concentration fluctuations with the same spectrum as thermal fluctuations but with increased intensity. PMID:24806919

  17. Inflammatory pseudotumor causing deep vein thrombosis after metal-on-metal hip resurfacing arthroplasty.

    LENUS (Irish Health Repository)

    Memon, Adeel Rasool

    2013-01-01

    Metal-on-metal hip resurfacings have recently been associated with a variety of complications resulting from adverse reaction to metal debris. We report a case of extensive soft tissue necrosis associated with a huge pelvic mass causing extensive deep vein thrombosis of the lower limb secondary to mechanical compression of the iliac vein. This is a rare and unusual cause of deep vein thrombosis after metal-on-metal hip resurfacing arthroplasty.

  18. Multimodal ultrasonographic assessment of leiomyosarcoma of the femoral vein in a patient misdiagnosed as having deep vein thrombosis

    Science.gov (United States)

    Zhang, Mei; Yan, Feng; Huang, Bin; Wu, Zhoupeng; Wen, Xiaorong

    2017-01-01

    Abstract Rationale: Primary leiomyosarcoma (LMS) of the vein is a rare tumor that arises from the smooth muscle cells of the vessel wall and has an extremely poor prognosis. This tumor can occur in vessels such as the inferior vena cava, great saphenous vein, femoral vein, iliac vein, popliteal vein, and renal vein; the inferior vena cava is the most common site. LMS of the femoral vein can result in edema and pain in the lower extremity; therefore, it is not easy to be differentiated from deep vein thrombosis (DVT). Moreover, virtually no studies have described the ultrasonographic features of LMS of the vein in detail. Patient concerns: We present a case of a 55-year-old woman with LMS of the left femoral vein that was misdiagnosed as having deep vein thrombosis (DVT) on initial ultrasonographic examination. The patient began to experience edema and pain in her left leg seven months previously. She was diagnosed as having DVT on initial ultrasonographic examination, but the DVT treatment that she had received for 7 months failed to improve the status of her left lower limb. Diagnoses: She subsequently underwent re-examination by means of a multimodal ultrasonographic imaging approach (regular B-mode imaging, color Doppler imaging, pulsed-wave Doppler imaging, contrast-enhanced ultrasonography), which confirmed a diagnosis of LMS. Interventions: This patient was treated successfully with surgery. Outcomes: This case demonstrates that use of multiple ultrasonographic imaging techniques can be helpful to diagnose LMS accurately. Detection of vasculature in a dilated vein filled with a heterogeneous hypoechoic substance on ultrasonography is a sign of a tumor. Lessons: The pitfall of misdiagnosing this tumor as DVT is a useful reminder. PMID:29145269

  19. Bilateral meandering pulmonary veins

    Energy Technology Data Exchange (ETDEWEB)

    Thupili, Chakradhar R.; Udayasankar, Unni [Pediatric Imaging, Imaging Institute Cleveland Clinic, Cleveland, OH (United States); Renapurkar, Rahul [Imaging Institute Cleveland Clinic, Thoracic Imaging, L10, Cleveland, OH (United States)

    2015-06-15

    Meandering pulmonary veins is a rare clinical entity that can be mistaken for more complex congenital syndromes such as hypogenetic lung syndrome. We report imaging findings in a rare incidentally detected case of bilateral meandering pulmonary veins. We briefly discuss the role of imaging in diagnosing this condition, with particular emphasis on contrast-enhanced CT. (orig.)

  20. Deep Vein Thrombosis

    African Journals Online (AJOL)

    OWNER

    Deep Vein Thrombosis: Risk Factors and Prevention in Surgical Patients. Deep Vein ... preventable morbidity and mortality in hospitalized surgical patients. ... the elderly.3,4 It is very rare before the age ... depends on the risk level; therefore an .... but also in the post-operative period. ... is continuing uncertainty regarding.

  1. The clinical efficacy evaluation of transcatheter hardening treatment for varicose veins of lower extremity

    International Nuclear Information System (INIS)

    Chen Junhui; Ren Yi; He Ping; Xiong Hongli; Wang Li; Zhou Xianbo

    2007-01-01

    Objective: To explore the clinical efficacy and safety of transcatheter absolute ethanol injection treatment on varicose veins of lower extremity. Methods: twenty-there patients with 25 varicose veins of lower extremity were treated by puncture of great saphenous vein above 1-2 cm of complicated inner ankle, perforating catheter to the point below the 3-4 cm of the conjunction of great saphenous vein and Femoral vein and pressing the conjunction of these two veins. Under the monitor of DSA, inject the absolute ethanol slowly while retrieve the catheter little by little (one limb with varicose veins injected total volume 15-20 mi), in the mean time, using contrast agent to monitor the level of embolism until the formation of total embolism in the all great saphenous veins. Results: All the cases were retrospectively followed up with CDFI examination after 3-12 months of the surgery, No blood flow were seen in the 25 embolismic great saphenous vein. Clinical symptom were alleviated obviously after 2-3 weeks of treatment; varicose veins were collapse after 3 to 7 days. Two cases of leg ulceration were healed after 4 to 6 weeks of operation. 20 limbs were found mild swelling in the 2 day after the surgery. However, all the cases were disappeared after 1 to 2 weeks; 4 treated limbs developed delayed paresthesia in the 3 day after the surgery, and recovered totally in the 2 weeks. No complications of deep vein thrombosis, lung thrombosis etc al, were found after operation. Conclusions: Using transcatheter injection of absolute ethanol to treat varicose veins of lower extremity has the advantage of less invasion, more safety and low appearance of complications. The short term efficacy is solid while the long term effect needs further evaluation. (authors)

  2. Transposition of cephalic vein to rescue hemodialysis access arteriovenous fistula and treat symptomatic central venous obstruction

    Directory of Open Access Journals (Sweden)

    Felipe Jose Skupien

    2014-03-01

    Full Text Available It is known that stenosis or central venous obstruction affects 20 to 50% of patients who undergo placement of catheters in central veins. For patients who are given hemodialysis via upper limbs, this problem causes debilitating symptoms and increases the risk of loss of hemodialysis access. We report an atypical case of treatment of a dialysis patient with multiple comorbidities, severe swelling and pain in the right upper limb (RUL, few alternative sites for hemodialysis vascular access, a functioning brachiobasilic fistula in the RUL and severe venous hypertension in the same limb, secondary to central vein occlusion of the internal jugular vein and right brachiocephalic trunk. The alternative surgical treatment chosen was to transpose the RUL cephalic vein, forming a venous necklace at the anterior cervical region, bypassing the site of venous occlusion. In order to achieve this, we dissected the cephalic vein in the right arm to its junction with the axillary vein, devalved the cephalic vein and anastomosed it to the contralateral external jugular vein, providing venous drainage to the RUL, alleviating symptoms of venous hypertension and preserving function of the brachiobasilic fistula.

  3. Preventing Deep Vein Thrombosis

    Science.gov (United States)

    ... Physicians Contact Us My ACOG ACOG Departments Donate Shop Career Connection Home Clinical Guidance & Publications Practice Management ... skin. A clot also can form if blood flow is too slow the lining of a vein ...

  4. The comparative anatomy of the forelimb veins of primates.

    OpenAIRE

    Thiranagama, R; Chamberlain, A T; Wood, B A

    1989-01-01

    One hundred and thirteen forelimbs taken from 62 individuals belonging to 17 primate genera were dissected to reveal the entire course of the superficial venous system. The course of the deep venous system was also documented in at least one forelimb of each primate genus, and the number and location of perforating veins was recorded in 18 human and 45 non-human primate limbs. In Pan, Gorilla and in about 25% of human specimens the lateral superficial vein was confined to the forearm, while i...

  5. Upper Extremity Deep Vein Thromboses: The Bowler and the Barista

    Directory of Open Access Journals (Sweden)

    Seth Stake

    2016-01-01

    Full Text Available Effort thrombosis of the upper extremity refers to a deep venous thrombosis of the upper extremity resulting from repetitive activity of the upper limb. Most cases of effort thrombosis occur in young elite athletes with strenuous upper extremity activity. This article reports two cases who both developed upper extremity deep vein thromboses, the first being a 67-year-old bowler and the second a 25-year-old barista, and illustrates that effort thrombosis should be included in the differential diagnosis in any patient with symptoms concerning DVT associated with repetitive activity. A literature review explores the recommended therapies for upper extremity deep vein thromboses.

  6. Upper Extremity Deep Vein Thromboses: The Bowler and the Barista.

    Science.gov (United States)

    Stake, Seth; du Breuil, Anne L; Close, Jeremy

    2016-01-01

    Effort thrombosis of the upper extremity refers to a deep venous thrombosis of the upper extremity resulting from repetitive activity of the upper limb. Most cases of effort thrombosis occur in young elite athletes with strenuous upper extremity activity. This article reports two cases who both developed upper extremity deep vein thromboses, the first being a 67-year-old bowler and the second a 25-year-old barista, and illustrates that effort thrombosis should be included in the differential diagnosis in any patient with symptoms concerning DVT associated with repetitive activity. A literature review explores the recommended therapies for upper extremity deep vein thromboses.

  7. Reinforced long saphenous vein bypass graft for infrainguinal reconstruction procedures: case series and literature review.

    LENUS (Irish Health Repository)

    Hynes, Niamh

    2006-03-01

    Poor rehabilitation rates and the high-cost of managing postamputation patients justify an aggressive revascularization policy in critical lower limb ischemia. Endovascular therapy is our first choice for limb salvage in these patients. However there are patients for whom endovascular therapy is not feasible. When bypass is necessary, autologous vein is a superior conduit to synthetic material. However, varicosities usually contraindicate autologous vein bypass because of the risk of aneurysm formation, rupture and increased intimal hyperplasia compared with nonvaricose venous grafts. We report the use of varicosed long saphenous vein (LSV) with external Dacron support in infrainguinal bypass procedures for limb salvage, where endovascular therapy was not feasible. The external Dacron tube was not brought close to the distal anastomotic area itself. With a mean follow-up of 18 months, duplex ultrasonography and computed tomography angiography showed no evidence of stenosis of the reinforced vein segments or aneurysmal degeneration of the residual vein. External reinforcement with Dacron prosthesis allows the use of autogenous greater saphenous veins with varicose dilatation without compromising graft patency and limb salvage.

  8. The color Doppler ultrasonography in in the diagnosis of deep vein thrombosis

    International Nuclear Information System (INIS)

    Ameneiro Perez, Santiago; Alvarez Sanchez, Jose A.; Rodriguez Villalonga, Luis; Borras Migues, Marisela; Quinnones Castro, Mayda

    2004-01-01

    The paper was aimed at evaluating the accuracy of color Doppler ultrasonography, a noninvasive method, in the diagnosis of deep vein thrombosis of the lower limbs, comparing it to the results of the cruel and costly diagnostic g olden rule , that is, phlebography. Methods: Color Doppler ultrasonography served to assess 102 patients clinically suspected of deep vein thrombosis of the lower limbs, taking into account the following criteria: vein compressibility, echographic images, color, Vein Doppler signal modulation after several maneuvers and distal compression. Sensitivity, specificity, positive and negative predictive values and diagnostic efficacy were estimated for each criteria, taking the phlebography as a reference. Results: Total or partial lack of vein compressibility combined with the vein flow evaluation is the ultrasonographic criterion that reveals higher degree of sensitivity, specificity and efficacy (0,98; 0,95 and 0,97 respectively. Color Doppler ultrasonography is a highly effective noninvasive diagnostic method that detects deep vein thrombosis in proximal areas of the lower limbs

  9. Elasto-hydrodynamic lubrication

    CERN Document Server

    Dowson, D; Hopkins, D W

    1977-01-01

    Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented.Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussio

  10. Elementary classical hydrodynamics

    CERN Document Server

    Chirgwin, B H; Langford, W J; Maxwell, E A; Plumpton, C

    1967-01-01

    Elementary Classical Hydrodynamics deals with the fundamental principles of elementary classical hydrodynamics, with emphasis on the mechanics of inviscid fluids. Topics covered by this book include direct use of the equations of hydrodynamics, potential flows, two-dimensional fluid motion, waves in liquids, and compressible flows. Some general theorems such as Bernoulli's equation are also considered. This book is comprised of six chapters and begins by introducing the reader to the fundamental principles of fluid hydrodynamics, with emphasis on ways of studying the motion of a fluid. Basic c

  11. Primary Iliac Venous Leiomyosarcoma: A Rare Cause of Deep Vein Thrombosis in a Young Patient

    Directory of Open Access Journals (Sweden)

    Nelson Oliveira

    2011-01-01

    Full Text Available Introduction. Primary venous tumours are a rare cause of deep vein thrombosis. The authors present a case where the definitive diagnosis was delayed by inconclusive complementary imaging. Clinical Case. A thirty-seven-year-old female presented with an iliofemoral venous thrombosis of the right lower limb. The patient had presented with an episode of femoral-popliteal vein thrombosis five months before and was currently under anticoagulation. Phlegmasia alba dolens installed progressively, as thrombus rapidly extended to the inferior vena cava despite systemic thrombolysis and anticoagulation. Diagnostic imaging failed to identify the underlying aetiology of the deep vein thrombosis. The definitive diagnosis of primary venous leiomyosarcoma was reached by a subcutaneous abdominal wall nodule biopsy. Conclusion. Primary venous leiomyosarcoma of the iliac vein is a rare cause of deep vein thrombosis, which must be considered in young patients with recurrent or refractory to treatment deep vein thrombosis.

  12. CO2-DSA in lower extremity veins: a clinical application

    International Nuclear Information System (INIS)

    Guo Jinhe; Teng Gaojun; Zhu Guangyu; Liu Zhensheng; Li Guozhao; Ding Huijuan; Shen Zhiping; He Shicheng; Deng Gang; Fang Wen

    2005-01-01

    Objective: To explore the feasibility and usefulness of carbon dioxide digital subtraction angiography (CO 2 -DSA) in deep veins of lower extremity via the dorsal is pedis vein. Methods: CO 2 -DSA in lower extremity veins was performed in 15 patients (15 limbs affected, male 9, female 6) by injection of CO 2 via the dorsal is pedis vein. Among them, 8 patients were suspected with deep venous thrombosis (DVT), 6 patients with saphena magna dilation, and 1 patient with a follow-up after thrombolysis due to DVT. Results: Excellent image was obtained in 12 cases, which showed branches of the venous system clearly, as well as the details of DVT. Good image was obtained in 2 cases. Technical failure was encountered in one patient due to inaccessible puncture veins. Mild discomfort (transient pain at the percutaneous site) during the procedure was demonstrated in 11 patients. There was no severe side effects or complications in this series. Conclusion: CO 2 -DSA in lower extremity veins is feasible and safe, the preliminary result is satisfactory. (authors)

  13. Varicography in the preoperative evaluation of primary varicose veins

    International Nuclear Information System (INIS)

    Pinzani, A.; Paoli, G.; Gongolo, A.; Spreafico, G.

    1989-01-01

    Primary varicose veins in the lower limb are usually well evaluated by the surgeon, who avails himself of tornequet tests and Doppler US. However, the operation is often followed by failure or recurrence, or else it requires ugly skin dissection to eradicate an unforeseeably complicated varicose vein. The authors suggest that, whenever the surgeon considers the information obtained with tests and Doppler US inadequate for planning surgery, varicography be performed to get further morphological (and functional) data about the origin of varicose veins, which is of fundamental importance for an accurate surgical planning (crossectomy, stripping, ligation, sclerosis). Out of 100 varicographies consecutively carried out on patients in whom clinical examination was not conclusive, 62% allowed an already planned surgical approach to be changed. The figure rose to 100% in the case of unusual varicose veins. Such a results allowed the needs of both the surgeon (selectivity, effectiveness, radicality) and the patients (narrow scars, absence of relapse) to be respected. Furthermore, it has been pointed out that some vein segments are often only pathological, and they are to be adequately treated, while others can be undamaged, and they are to be preserved for both their function and an eventual by-pass surgery. Varicography is rapidly performed, without complication, and is well accepted by the patients. It is a fundamental help in the preoperative study of primary varicose veins, especially in case of unusual ones, whenever the surgeon is in the slightest diagnostic - and therefore surgical - doubt

  14. Portal vein thrombosis.

    Science.gov (United States)

    Chawla, Yogesh K; Bodh, Vijay

    2015-03-01

    Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

  15. The vein collar

    DEFF Research Database (Denmark)

    Lundgren, F; Schroeder, Torben Veith

    2012-01-01

    Randomized studies evaluating the effect of a vein collar at the distal anastomosis of PTFE-grafts show conflicting results. The study of the Joint Vascular Research Group (JVRG) of UK found improved primary patency while the Scandinavian Miller Collar Study (SCAMICOS) found neither any effect...

  16. Deep Vein Thrombosis

    Centers for Disease Control (CDC) Podcasts

    2012-04-05

    This podcast discusses the risk for deep vein thrombosis in long-distance travelers and ways to minimize that risk.  Created: 4/5/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/5/2012.

  17. [Deep vein thrombosis prophylaxis.

    Science.gov (United States)

    Sandoval-Chagoya, Gloria Alejandra; Laniado-Laborín, Rafael

    2013-01-01

    Background: despite the proven effectiveness of preventive therapy for deep vein thrombosis, a significant proportion of patients at risk for thromboembolism do not receive prophylaxis during hospitalization. Our objective was to determine the adherence to thrombosis prophylaxis guidelines in a general hospital as a quality control strategy. Methods: a random audit of clinical charts was conducted at the Tijuana General Hospital, Baja California, Mexico, to determine the degree of adherence to deep vein thrombosis prophylaxis guidelines. The instrument used was the Caprini's checklist for thrombosis risk assessment in adult patients. Results: the sample included 300 patient charts; 182 (60.7 %) were surgical patients and 118 were medical patients. Forty six patients (15.3 %) received deep vein thrombosis pharmacologic prophylaxis; 27.1 % of medical patients received deep vein thrombosis prophylaxis versus 8.3 % of surgical patients (p < 0.0001). Conclusions: our results show that adherence to DVT prophylaxis at our hospital is extremely low. Only 15.3 % of our patients at risk received treatment, and even patients with very high risk received treatment in less than 25 % of the cases. We have implemented strategies to increase compliance with clinical guidelines.

  18. Radionuclide venography of lower limbs by subcutaneous injection

    International Nuclear Information System (INIS)

    Wu, Chung-Chieng; Jong, Shiang-Bin

    1989-01-01

    We have proved that subcutaneous injection (SC) of a small dose of Tc-99m pertechnetate (1 to 2 mCi: 37 to 74 MBq) at acupuncture points (K-3 and B-60) may offer an alternative method of radionuclide venography (RNV) of the lower limbs. In this study, we compared intravenous (IV) RNV and SC-RNV in 22 consecutive cases with typical signs and symptoms suggesting venous abnormality of the lower limb(s) from March to May 1988. They are 11 male and 11 female, aged 47.7±15.7 years. Among the 44 limbs of the 22 cases, 4 were normal, 12 (27.3%) were found to have varicose veins in the legs only, 18 (40.9%) had partial stenosis of the deep veins (14 poplito-tibial and 4 superficial femoral), and 13 (29.6%) had complete stenosis of the deep veins (4 poplito-tibial, 1 superficial femoral and 8 ilio-femoral. SC-RNV showed almost the same results as IV-RNV in 21 (47.7%), superior to IV-RNV in 22 (50%) (including 4.6% failure of IV-RNV), and inferior to IV-RNV in 1 (2.3%). We conclude that SC-RNV is definitely an alternative method of lower-limb venography. Since it is in most cases superior to IV-RNV, we suggest that it can take the place of IV-RNV in routine work. (author) 62 refs

  19. Collateral veins in left renal vein stenosis demonstrated via CT

    Energy Technology Data Exchange (ETDEWEB)

    Lien, H.H.; Lund, G.; Talle, K.

    1983-02-01

    Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development.

  20. Collateral veins in left renal vein stenosis demonstrated via CT

    International Nuclear Information System (INIS)

    Lien, H.H.; Lund, G.; Talle, K.

    1983-01-01

    Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development. (orig.)

  1. Concerns and Discomforts of Pregnancy - Varicose Veins

    Science.gov (United States)

    Concerns and Discomforts of Pregnancy - Varicose Veins Varicose veins are enlarged veins you may see on your ... Healthy Roads Media project www. healthyroadsmedia. org English - Concerns and Discomforts of Pregnancy (Varicose Veins) Last reviewed ...

  2. Congenital vascular malformations: the persistence of marginal and embryonal veins.

    Science.gov (United States)

    Weber, J; Daffinger, N

    2006-05-01

    In about 18% of cases with conginental vascular malformations we find a perspective of an atypical truncular vein, located along the outside of the leg, frequently extended from the dorsal foot up to the bottom. In presence of a normally developed system of the deep collecting veins of the lower limb and within the pelvic outflow we are talking about a persisting marginal vein (MV). Hypoplasia or even aplasia of the main deep veins in contrary defines the persisting embryonal vein (EV). Already in childhood these truncular dysplastic veins tend to develop varicose enlargement, causing severe reflux of a huge volume of blood--even more when being associated with av-fistulas (46%). In consequence a rapidly growing chronic venous insufficiency will guide to additional injuries. We have analysed 97 patients showing a persisting MV (n: 92 ) within a total of 102 legs. A persistent embryonal vein (EV) was seen 10 times within this clientel. The persisting truncular veins, associated with phlebectasias and typical clinical symptoms have been examined in a diagnostic "step-by-step" procedure, mainly phlebographically (ascending leg phlebography and varicography), including direct venous blood pressure measurements (phlebodynamometry) and--if needed--by arteriography, showing av-shunting fistulae in 46% of cases. CT and MRI were consulted for the exact therapy planing (frequently initially offered as a non-invasive, however, inadequate key of diagnostic). Actually now these techniques cannot replace pre-operatively the angiographic imaging techniques. The analysis of clinical, morphologic and functional signs, guiding to a specific therapy-relevant classification of MV's and EV's will be presented. And a specific strategy of surgical repair, interventional treatment of av-fistulas and conservative compressive follow-up treatment attempting palliative recompensation of the diseased venous outflow will be discussed also.

  3. Multimodal ultrasonographic assessment of leiomyosarcoma of the femoral vein in a patient misdiagnosed as having deep vein thrombosis: A case report.

    Science.gov (United States)

    Zhang, Mei; Yan, Feng; Huang, Bin; Wu, Zhoupeng; Wen, Xiaorong

    2017-11-01

    Primary leiomyosarcoma (LMS) of the vein is a rare tumor that arises from the smooth muscle cells of the vessel wall and has an extremely poor prognosis. This tumor can occur in vessels such as the inferior vena cava, great saphenous vein, femoral vein, iliac vein, popliteal vein, and renal vein; the inferior vena cava is the most common site. LMS of the femoral vein can result in edema and pain in the lower extremity; therefore, it is not easy to be differentiated from deep vein thrombosis (DVT). Moreover, virtually no studies have described the ultrasonographic features of LMS of the vein in detail. We present a case of a 55-year-old woman with LMS of the left femoral vein that was misdiagnosed as having deep vein thrombosis (DVT) on initial ultrasonographic examination. The patient began to experience edema and pain in her left leg seven months previously. She was diagnosed as having DVT on initial ultrasonographic examination, but the DVT treatment that she had received for 7 months failed to improve the status of her left lower limb. She subsequently underwent re-examination by means of a multimodal ultrasonographic imaging approach (regular B-mode imaging, color Doppler imaging, pulsed-wave Doppler imaging, contrast-enhanced ultrasonography), which confirmed a diagnosis of LMS. This patient was treated successfully with surgery. This case demonstrates that use of multiple ultrasonographic imaging techniques can be helpful to diagnose LMS accurately. Detection of vasculature in a dilated vein filled with a heterogeneous hypoechoic substance on ultrasonography is a sign of a tumor. The pitfall of misdiagnosing this tumor as DVT is a useful reminder.

  4. Accessory hepatic vein: MR imaging

    International Nuclear Information System (INIS)

    Lee, Chang Hee; Rho, Tack Soo; Cha, Sang Hoon; Park, Cheol Min; Cha, In Ho

    1995-01-01

    To evaluate the MR appearance of the accessory hepatic veins. The study included 87 consecutive patients for whom abdominal MR images were obtained. The subjects who had liver lesion or hepatic vascular abnormalities were excluded. Couinaud classified accessory hepatic veins into inferior and middle right hepatic veins. Our major interests were evaluation of the incidence, morphology, and location of the accessory hepatic vein. Inferior right hepatic vein was demonstrated in 43 out of 87 patients (49%). The morphology was linear in 35 patients (80.5%), and V-shaped in 8 patients (19.5%). In 40 patients (93%), the inferior right hepatic vein was located in the posteroinferior aspect of the right lobe. Middle right hepatic vein was demonstrated in 7 out of 87 patients (8%). All were single linear in morphology, combined with the inferior right hepatic vein, and located between the right hepatic vein and inferior right hepatic vein. The accessory hepatic vein was demonstrated in 49% among the Korean adult population, and was located in posteroinferior portion of the liver, in 93%

  5. [Clinical analysis of lower limb thrombosis caused by paraquat poisoning].

    Science.gov (United States)

    Yu, L J; Jian, X D; Zhang, Z C; Ren, Y L; Ning, Q; Wang, K; Gao, B J; Jia, J E

    2018-01-20

    Objective: To investigate the causes of peripheral vascular thrombosis in patients with paraquat poisoning. Methods: The patients with paraquat poisoning who were admitted to our department in recent two years were observed to screen out the patients with large vessel thrombosis. The data on toxic exposure history, clinical features, and treatment were collected to analyze the causes of thrombosis in the patients with paraquat poisoning. Results: Three patients had typical lower limb thrombosis. There was one case of right common femoral vein thrombosis, one case of bilateral calf muscle vein thrombosis, and one case of right calf superficial vein thrombosis and right calf muscle vein thrombosis. Conclusions: After paraquat poisoning, the blood is in a hypercoagulable state and prolonged bed rest may increase the risk of thrombosis.

  6. Catheter directed thrombolysis for deep vein thrombosis during the first trimester of pregnancy: two case report

    International Nuclear Information System (INIS)

    Kim, Kum Rae; Park, Won Kyu; Kim, Jae Woon; Kwun, Woo Hyung; Suh, Bo Yang; Park, Kyeong Seok

    2008-01-01

    Anticoagulation with heparin has been the standard management therapy of deep vein thrombosis during pregnancy. Pregnancy is generally considered as a contraindication for thrombolysis. However, anticoagulation therapy alone does not protect the limbs from post-thrombotic syndrome and venous valve insufficiency. Catheter-directed thrombolysis, combined with angioplasty and stenting, can remove the thrombus and restore patency of the veins, resulting in prevention of post-thrombotic syndrome and valve insufficiency. We report successful catheter-directed thrombolysis and stenting in two early gestation patients with a deep vein thrombosis of the left lower extremity

  7. Catheter directed thrombolysis for deep vein thrombosis during the first trimester of pregnancy: two case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kum Rae; Park, Won Kyu; Kim, Jae Woon; Kwun, Woo Hyung; Suh, Bo Yang [College of Medicine, Yeungnam University, Daegu (Korea, Republic of); Park, Kyeong Seok [Yeungnam University, Medical Center, Daegu (Korea, Republic of)

    2008-02-15

    Anticoagulation with heparin has been the standard management therapy of deep vein thrombosis during pregnancy. Pregnancy is generally considered as a contraindication for thrombolysis. However, anticoagulation therapy alone does not protect the limbs from post-thrombotic syndrome and venous valve insufficiency. Catheter-directed thrombolysis, combined with angioplasty and stenting, can remove the thrombus and restore patency of the veins, resulting in prevention of post-thrombotic syndrome and valve insufficiency. We report successful catheter-directed thrombolysis and stenting in two early gestation patients with a deep vein thrombosis of the left lower extremity.

  8. Leiomyosarcoma of the great saphenous vein

    Directory of Open Access Journals (Sweden)

    Alexandre Campos Moraes Amato

    2015-06-01

    Full Text Available A 56-year-old male patient presented with a complaint of two painful, hard, palpable nodules in the right lower limb. A Doppler ultrasound scan revealed the presence of nodules, likely to be neoplastic. Computed angiography showed two solid hypervascular nodules in the right great saphenous vein, fed by branches of the posterior tibial artery. Embolization of the nodules using surgical cyanoacrylate was performed, followed by an excisional biopsy. Anatomical pathology and immunohistochemical analysis identified the nodule as a high-grade leiomyosarcoma, characterized by ten mitotic figures per ten high-power fields, necrosis and cell pleomorphism. Immunohistochemical analysis results were positive for caldesmon and desmin labeling. A second surgical procedure was performed to enlarge the free margins.

  9. Vein grafting in fingertip replantations.

    Science.gov (United States)

    Yan, Hede; Jackson, William D; Songcharoen, Somjade; Akdemir, Ovunc; Li, Zhijie; Chen, Xinglong; Jiang, Liangfu; Gao, Weiyang

    2009-01-01

    In this retrospective study, the survival rates of fingertip replantation with and without vein grafting were evaluated along with their postoperative functional and cosmetic results. One hundred twenty-one-fingertip amputations were performed in 103 patients between September 2002 and July 2007. Thirty-four amputated fingertips were replanted without vein grafting, while 87 amputated fingertips were replanted with vein grafting for arterial and/or venous repairs. The overall survival rates of the replantations with and without vein grafting were 90% (78/87) and 85% (29/34), respectively. The survival rates were 88% (36/41) with venous repair, 93% (25/27) with arterial repair, and 89% (17/19) with both. Nineteen patients without vein grafting and 48 patients with vein grafting had a follow-up period of more than one year. Good cosmetic and functional outcomes were observed in both groups of patients. The results show that vein grafting is a reliable technique in fingertip replantations, showing no significant difference (P > 0.05) in survival between those with and without vein grafting. Furthermore, no significant difference (P > 0.05) in survival was found between cases with vein grafts for arterial and/or venous repairs. In fingertip replantations with vein grafting, favorable functional and esthetic results can be achieved without sacrificing replantation survival. (c) 2009 Wiley-Liss, Inc.

  10. Ultrasound diagnosis of lower limb deep venous thrombosis.

    Science.gov (United States)

    Fletcher, J P; Kershaw, L Z; Barker, D S; Koutts, J; Varnava, A

    1990-10-15

    Venous ultrasound imaging was compared with ascending contrast venography for the diagnosis of suspected deep vein thrombosis (DVT) in the femoral, popliteal and calf vein segments of 44 limbs in 44 patients. One femoral and one calf vein segment could not be imaged (1.5% of the segments examined), but during the same period venography failed in six patients because of an inability to cannulate a swollen limb. Ultrasound imaging compared with venography as a means of diagnosing DVT showed an overall sensitivity of 95% and a specificity of 92%. The sensitivity and specificity of ultrasound imaging for the diagnosis of both femoral and popliteal vein thromboses were 100% and 97%, respectively, and for calf vein thrombosis were 85% and 83%, respectively. This study supports the recommendation that ultrasound imaging is now the investigation of choice for the diagnosis of DVT provided that the scan is performed by an experienced vascular technologist. Ultrasound imaging may also define other pathological conditions presenting in the differential diagnosis of DVT, such as superficial thrombophlebitis and Baker's cyst.

  11. Endovascular Radiofrequency Ablation for Varicose Veins

    Science.gov (United States)

    2011-01-01

    or worse as other chronic diseases such as back pain and arthritis. Lower limb VV is a very common disease affecting adults – estimated to be the 7th most common reason for physician referral in the US. There is a very strong familial predisposition to VV. The risk in offspring is 90% if both parents affected, 20% when neither affected and 45% (25% boys, 62% girls) if one parent affected. The prevalence of VV worldwide ranges from 5% to 15% among men and 3% to 29% among women varying by the age, gender and ethnicity of the study population, survey methods and disease definition and measurement. The annual incidence of VV estimated from the Framingham Study was reported to be 2.6% among women and 1.9% among men and did not vary within the age range (40-89 years) studied. Approximately 1% of the adult population has a stasis ulcer of venous origin at any one time with 4% at risk. The majority of leg ulcer patients are elderly with simple superficial vein reflux. Stasis ulcers are often lengthy medical problems and can last for several years and, despite effective compression therapy and multilayer bandaging are associated with high recurrence rates. Recent trials involving surgical treatment of superficial vein reflux have resulted in healing and significantly reduced recurrence rates. Endovascular Radiofrequency Ablation for Varicose Veins RFA is an image-guided minimally invasive treatment alternative to surgical stripping of superficial venous reflux. RFA does not require an operating room or general anaesthesia and has been performed in an outpatient setting by a variety of medical specialties including surgeons and interventional radiologists. Rather than surgically removing the vein, RFA works by destroying or ablating the refluxing vein segment using thermal energy delivered through a radiofrequency catheter. Prior to performing RFA, color-flow Doppler ultrasonography is used to confirm and map all areas of venous reflux to devise a safe and effective

  12. Hydrodynamic optical soliton tunneling

    Science.gov (United States)

    Sprenger, P.; Hoefer, M. A.; El, G. A.

    2018-03-01

    A notion of hydrodynamic optical soliton tunneling is introduced in which a dark soliton is incident upon an evolving, broad potential barrier that arises from an appropriate variation of the input signal. The barriers considered include smooth rarefaction waves and highly oscillatory dispersive shock waves. Both the soliton and the barrier satisfy the same one-dimensional defocusing nonlinear Schrödinger (NLS) equation, which admits a convenient dispersive hydrodynamic interpretation. Under the scale separation assumption of nonlinear wave (Whitham) modulation theory, the highly nontrivial nonlinear interaction between the soliton and the evolving hydrodynamic barrier is described in terms of self-similar, simple wave solutions to an asymptotic reduction of the Whitham-NLS partial differential equations. One of the Riemann invariants of the reduced modulation system determines the characteristics of a soliton interacting with a mean flow that results in soliton tunneling or trapping. Another Riemann invariant yields the tunneled soliton's phase shift due to hydrodynamic interaction. Soliton interaction with hydrodynamic barriers gives rise to effects that include reversal of the soliton propagation direction and spontaneous soliton cavitation, which further suggest possible methods of dark soliton control in optical fibers.

  13. Small systems – hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bożek, Piotr, E-mail: piotr.bozek@fis.agh.edu.pl

    2016-12-15

    The scenario assuming a collective expansion stage in collisions of small systems, p-A, d-Au, and {sup 3}He-Au is discussed. A review of the observables predicted in relativistic hydrodynamic models in comparison with experimental data is presented, with arguments indicating the presence of collective expansion. The limits of applicability of the hydrodynamic model are addressed. We briefly indicate possible applications of the collective flow in small systems to study the space-time dynamics at very small scales in relativistic collisions.

  14. Diagnosis of deep vein thrombosis using autologous indium-III-labelled platelets

    International Nuclear Information System (INIS)

    Fenech, A.; Hussey, J.K.; Smith, F.W.; Dendy, P.P.; Bennett, B.; Douglas, A.S.

    1981-01-01

    Forty-eight patients who had undergone surgical reduction of a fractured neck of femur or in whom deep vein thrombosis was suspected clinically were studied by ascending phlebography and imaging after injection of autologous indium-III-labelled platelets to assess the accuracy and value of the radioisotopic technique in diagnosing deep vein thrombosis. Imaging was performed with a wide-field gammacamera linked with data display facilities. Phlebography showed thrombi in 26 out of 54 limbs examined and a thrombus in the inferior vena cava of one patient; imaging the labelled platelets showed the thrombi in 24 of the 26 limbs and the thrombus in the inferior vena cava. The accumulation of indium-III at sites corresponding to those at which venous thrombi have been shown phlebographically indicates that this radioisotopic technique is a useful addition to methods already available for the detection of deep vein thrombosis. (author)

  15. Diagnosis of deep vein thrombosis using autologous indium-III-labelled platelets

    Energy Technology Data Exchange (ETDEWEB)

    Fenech, A.; Hussey, J.K.; Smith, F.W.; Dendy, P.P.; Bennett, B.; Douglas, A.S. (Aberdeen Univ. (UK))

    1981-03-28

    Forty-eight patients who had undergone surgical reduction of a fractured neck of femur or in whom deep vein thrombosis was suspected clinically were studied by ascending phlebography and imaging after injection of autologous indium-III-labelled platelets to assess the accuracy and value of the radioisotopic technique in diagnosing deep vein thrombosis. Imaging was performed with a wide-field gamma camera linked with data display facilities. Phlebography showed thrombi in 26 out of 54 limbs examined and a thrombus in the inferior vena cava of one patient; imaging the labelled platelets showed the thrombi in 24 of the 26 limbs and the thrombus in the inferior vena cava. The accumulation of indium-III at sites corresponding to those at which venous thrombi have been shown phlebographically indicates that this radioisotopic technique is a useful addition to methods already available for the detection of deep vein thrombosis.

  16. Leiomyosarcoma of the renal vein

    Directory of Open Access Journals (Sweden)

    Lemos Gustavo C.

    2003-01-01

    Full Text Available Leiomyosarcoma of the renal vein is a rare tumor of complex diagnosis. We presented a case of renal vein leiomyosarcoma detected in a routine study. The primary treatment was complete surgical removal of the mass. In cases where surgical removal is not possible the prognosis is poor, with high rates of local recurrence and distant spread.

  17. Vein type uranium deposits

    International Nuclear Information System (INIS)

    1986-01-01

    Veins are tabular- or sheet-like masses of minerals occupying or following a fracture or a set of fractures in the enclosing rock. They have been formed later than the country rock and fractures, either by filling of the open spaces or by partial or complete replacement of the adjoining rock or most commonly by both of these processes combined. This volume begins with the occurrences and deposits known from old shield areas and the sedimentary belts surrounding them. They are followed by papers describing the European deposits mostly of Variscan age, and by similar deposits known from China being of Jurassic age. The volume is completed by two papers which do not fit exactly in the given scheme. A separate abstract was prepared for each of the 25 papers in this report

  18. The economics of vein disease.

    Science.gov (United States)

    Sales, Clifford M; Podnos, Joan; Levison, Jonathan

    2007-09-01

    The management of cosmetic vein problems requires a very different approach than that for the majority of most other vascular disorders that occur in a vascular surgery practice. This article focuses on the business aspects of a cosmetic vein practice, with particular attention to the uniqueness of these issues. Managing patient expectations is critical to the success of a cosmetic vein practice. Maneuvering within the insurance can be difficult and frustrating for both the patient and the practice. Practices should use cost accounting principles to evaluate the success of their vein work. Vein surgery--especially if performed within the office--can undergo an accurate break-even analysis to determine its profitability.

  19. Hydrodynamical description of collective flow

    OpenAIRE

    Huovinen, Pasi

    2003-01-01

    I review how hydrodynamical flow is related to the observed flow in ultrarelativistic heavy ion collisions and how initial conditions, equation of state and freeze-out temperature affect flow in hydrodynamical models.

  20. Dissipative relativistic hydrodynamics

    International Nuclear Information System (INIS)

    Imshennik, V.S.; Morozov, Yu.I.

    1989-01-01

    Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova

  1. Hydrodynamic interactions in metachronal paddling: effects of varying stroke kinematics

    Science.gov (United States)

    Samaee, Milad; Kasoju, Vishwa; Lai, Hong Kuan; Santhanakrishnan, Arvind

    2017-11-01

    Crustaceans such as shrimp and krill use a drag-based technique for propulsion, in which multiple pairs of limbs are paddled rhythmically from the tail to the head. Each limb is phase-shifted in time relative to its neighbor. Most studies of this type of metachronal swimming have focused on the jet formed in the animal's wake. However, synergistic hydrodynamic interactions between adjacent limbs in metachrony have received minimal attention. We used a dynamically scaled robotic model to experimentally investigate how variations in stroke kinematics impact inter-paddle hydrodynamic interactions and thrust generation. Physical models of limbs were fitted to the robot and paddled with two different motion profiles (MPs)-1) MP1: metachronal power stroke (PS) and metachronal recovery stroke (RS); and 2) MP2: metachronal PS and synchronous RS. Stroke frequency and amplitude were maintained constant across both MPs. Our results show that MP2 produced faster jets in the thrust-generating direction as compared to MP1. The necessity for a pause in MP2 after completion of PS by the paddles leading the motion, prior to executing the synchronous RS, aided in further downstream flow propagation. The effect of using asymmetric stroke kinematics on thrust generated will be discussed.

  2. Varicose Vein Treatment (Endovenous Ablation of Varicose Veins)

    Science.gov (United States)

    ... associated veins. top of page What are the benefits vs. risks? Benefits No surgical incision is needed—only a small ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ...

  3. Vein matching using artificial neural network in vein authentication systems

    Science.gov (United States)

    Noori Hoshyar, Azadeh; Sulaiman, Riza

    2011-10-01

    Personal identification technology as security systems is developing rapidly. Traditional authentication modes like key; password; card are not safe enough because they could be stolen or easily forgotten. Biometric as developed technology has been applied to a wide range of systems. According to different researchers, vein biometric is a good candidate among other biometric traits such as fingerprint, hand geometry, voice, DNA and etc for authentication systems. Vein authentication systems can be designed by different methodologies. All the methodologies consist of matching stage which is too important for final verification of the system. Neural Network is an effective methodology for matching and recognizing individuals in authentication systems. Therefore, this paper explains and implements the Neural Network methodology for finger vein authentication system. Neural Network is trained in Matlab to match the vein features of authentication system. The Network simulation shows the quality of matching as 95% which is a good performance for authentication system matching.

  4. Thrombosis of right ovarian vein

    International Nuclear Information System (INIS)

    Forner, J.; Talens, A.; Flores, M.; Mendez, M.

    2001-01-01

    Ovarian vein thrombosis is a rare postpartum complication (0.1%). It can be fatal, since it can lead to sepsis, pulmonary thromboembolisms and inferior vena cava or renal vein thrombosis. Computed tomography and magnetic resonance imaging are the techniques of choice for its diagnosis, while the value of ultrasound is limited due to its low sensitivity and specificity. We report the case of a woman who, during puerperium, developed thrombosis of right ovarian vein that presented clinical, ultrasonographic and computed tomographic features of appendicitis. We describe the radiological sings and stress the fact that this diagnosis should be suspected in puerperal women. (Author) 9 refs

  5. Subclavian vein thrombosis following fracture of the clavicle: case report

    OpenAIRE

    Terra, Bernardo Barcellos; Cocco, Luiz Fernando; Ejnisman, Benno; Fernandes, Hélio Jorge Alvachian; Reis, Fernando Baldy dos

    2011-01-01

    A trombose venosa profunda no membro superior não é frequente na literatura ortopédica. Relatamos um caso de trombose da veia subclávia durante o tratamento conservador de fratura do terço médio da clavícula. O diagnóstico é difícil e requer um alto grau de suspeição e o tratamento pode prevenir um tromboembolismo fatal. Há raros casos descritos associados à fratura de clavícula.Deep vein thrombosis in the upper limbs is uncommon in the orthopedic literature. We report on a case of subclavian...

  6. Deep vein thrombosis: A rare complication in oral and maxillofacial surgery: A review of two cases

    Directory of Open Access Journals (Sweden)

    M.R. Ramesh Babu

    2013-01-01

    Full Text Available Deep vein thrombosis (DVT is caused by obstruction of blood flow of deep veins in upper and lower limb. One of the precipitating factors for DVT is surgery under general anesthesia exceeding 30 min. However, there are very few reports of DVT associated with surgery of oral and maxillofacial region. In this paper we report two cases of DVT involving left ilio-femoropopliteal deep vein in one patient treated for fractured left angle of mandible and left peroneal vein in the other patient treated for oral sub mucous fibrosis. Clinical and color Doppler examination were performed to diagnose the condition and were referred to vascular surgical unit of higher institute for further management. These cases illustrates any surgery of maxillofacial region is not free from risk of DVT, which can cause fatal pulmonary thromboembolism.

  7. An overview of hydrodynamic studies of mineralization

    Directory of Open Access Journals (Sweden)

    Guoxiang Chi

    2011-07-01

    Full Text Available Fluid flow is an integral part of hydrothermal mineralization, and its analysis and characterization constitute an important part of a mineralization model. The hydrodynamic study of mineralization deals with analyzing the driving forces, fluid pressure regimes, fluid flow rate and direction, and their relationships with localization of mineralization. This paper reviews the principles and methods of hydrodynamic studies of mineralization, and discusses their significance and limitations for ore deposit studies and mineral exploration. The driving forces of fluid flow may be related to fluid overpressure, topographic relief, tectonic deformation, and fluid density change due to heating or salinity variation, depending on specific geologic environments and mineralization processes. The study methods may be classified into three types, megascopic (field observations, microscopic analyses, and numerical modeling. Megascopic features indicative of significantly overpressured (especially lithostatic or supralithostatic fluid systems include horizontal veins, sand injection dikes, and hydraulic breccias. Microscopic studies, especially microthermometry of fluid inclusions and combined stress analysis and microthermometry of fluid inclusion planes (FIPs can provide important information about fluid temperature, pressure, and fluid-structural relationships, thus constraining fluid flow models. Numerical modeling can be carried out to solve partial differential equations governing fluid flow, heat transfer, rock deformation and chemical reactions, in order to simulate the distribution of fluid pressure, temperature, fluid flow rate and direction, and mineral precipitation or dissolution in 2D or 3D space and through time. The results of hydrodynamic studies of mineralization can enhance our understanding of the formation processes of hydrothermal deposits, and can be used directly or indirectly in mineral exploration.

  8. Hydrodynamics of Turning Flocks

    OpenAIRE

    Yang, Xingbo; Marchetti, M. Cristina

    2014-01-01

    We present a hydrodynamic model of flocking that generalizes the familiar Toner-Tu equations to incorporate turning inertia of well-polarized flocks. The continuum equations controlled by only two dimensionless parameters, orientational inertia and alignment strength, are derived by coarse graining the inertial spin model recently proposed by Cavagna et al. The interplay between orientational inertia and bend elasticity of the flock yields anisotropic spin waves that mediate the propagation o...

  9. A Vein Map Biometric System

    Directory of Open Access Journals (Sweden)

    Felix Fuentes

    2013-08-01

    Full Text Available There is increasing demand world-wide, from government agencies and the private sector for cutting-edge biometric security technology that is difficult to breach but userfriendly at the same time. Some of the older tools, such as fingerprint, retina and iris scanning, and facial recognition software have all been found to have flaws and often viewed negatively because of many cultural and hygienic issues associated with them. Comparatively, mapping veins as a human barcode, a new technology, has many advantages over older technologies. Specifically, reproducing a three-dimensional model of a human vein system is impossible to replicate. Vein map technology is distinctive because of its state-of-the-art sensors are only able to recognize vein patterns if hemoglobin is actively flowing through the person

  10. Hydrodynamics of insect spermatozoa

    Science.gov (United States)

    Pak, On Shun; Lauga, Eric

    2010-11-01

    Microorganism motility plays important roles in many biological processes including reproduction. Many microorganisms propel themselves by propagating traveling waves along their flagella. Depending on the species, propagation of planar waves (e.g. Ceratium) and helical waves (e.g. Trichomonas) were observed in eukaryotic flagellar motion, and hydrodynamic models for both were proposed in the past. However, the motility of insect spermatozoa remains largely unexplored. An interesting morphological feature of such cells, first observed in Tenebrio molitor and Bacillus rossius, is the double helical deformation pattern along the flagella, which is characterized by the presence of two superimposed helical flagellar waves (one with a large amplitude and low frequency, and the other with a small amplitude and high frequency). Here we present the first hydrodynamic investigation of the locomotion of insect spermatozoa. The swimming kinematics, trajectories and hydrodynamic efficiency of the swimmer are computed based on the prescribed double helical deformation pattern. We then compare our theoretical predictions with experimental measurements, and explore the dependence of the swimming performance on the geometric and dynamical parameters.

  11. Female Pelvic Vein Embolization: Indications, Techniques, and Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Anthony James, E-mail: consultant@radiologist.co.uk [The Imaging Clinic (United Kingdom)

    2015-08-15

    Until recently, the main indication for pelvic vein embolization (PVE) in women was to treat pelvic venous congestion syndrome (PVC) but increasingly, patients with refluxing pelvic veins associated with leg varicosities are also being treated. A more unusual reason for PVE is to treat pelvic venous malformations, although such lesions may be treated with sclerotherapy alone. Embolotherapy for treating PVC has been performed for many years with several published studies included in this review, whilst an emerging indication for PVE is to treat lower limb varicosities associated with pelvic vein reflux. Neither group, however, has been subjected to an adequate randomized, controlled trial. Consequently, some of the information presented in this review should be considered anecdotal (level III evidence) at this stage, and a satisfactory ‘proof’ of clinical efficacy remains deficient until higher-level evidence is presented. Furthermore, a wide range of techniques not accepted by all are used, and some standardization will be required based on future mandatory prospective studies. Large studies have also clearly shown an unacceptably high recurrence rate of leg varicose veins following venous surgery. Furthermore, minimally or non-invasive imaging is now revealing that there is a refluxing pelvic venous source in a significant percentage of women with de novo leg varicose veins, and many more with recurrent varicosities. Considering that just over half the world’s population is female and a significant number of women not only have pelvic venous reflux, but also have associated leg varicosities, minimally invasive treatment of pelvic venous incompetence will become a common procedure.

  12. Female Pelvic Vein Embolization: Indications, Techniques, and Outcomes

    International Nuclear Information System (INIS)

    Lopez, Anthony James

    2015-01-01

    Until recently, the main indication for pelvic vein embolization (PVE) in women was to treat pelvic venous congestion syndrome (PVC) but increasingly, patients with refluxing pelvic veins associated with leg varicosities are also being treated. A more unusual reason for PVE is to treat pelvic venous malformations, although such lesions may be treated with sclerotherapy alone. Embolotherapy for treating PVC has been performed for many years with several published studies included in this review, whilst an emerging indication for PVE is to treat lower limb varicosities associated with pelvic vein reflux. Neither group, however, has been subjected to an adequate randomized, controlled trial. Consequently, some of the information presented in this review should be considered anecdotal (level III evidence) at this stage, and a satisfactory ‘proof’ of clinical efficacy remains deficient until higher-level evidence is presented. Furthermore, a wide range of techniques not accepted by all are used, and some standardization will be required based on future mandatory prospective studies. Large studies have also clearly shown an unacceptably high recurrence rate of leg varicose veins following venous surgery. Furthermore, minimally or non-invasive imaging is now revealing that there is a refluxing pelvic venous source in a significant percentage of women with de novo leg varicose veins, and many more with recurrent varicosities. Considering that just over half the world’s population is female and a significant number of women not only have pelvic venous reflux, but also have associated leg varicosities, minimally invasive treatment of pelvic venous incompetence will become a common procedure

  13. Persistence of the embryonic lateral marginal vein: report of two cases

    Directory of Open Access Journals (Sweden)

    Rojas Martinez Raúl

    2001-01-01

    Full Text Available PURPOSE: Congenital venous malformations of the lower limbs represent a particular challenge for the vascular surgeon. Persistence of fetal veins is a rare malformation, and the most common is the persistence of the lateral marginal vein usually observed in patients with Klippel-Trenaunnay Syndrome. The persistence of this embryonic vein as an isolated venous malformation without the other characteristics of the Klippel-Trenaunnay Syndrome has not yet been reported. This paper describes two cases. METHODS: Two patients, a 17-year-old male patient and a 16-year-old female, have had since their birth a large venous trunk in the lateral aspect of the right leg and thigh. The limbs underwent duplex scanning and phlebography. The surgical removal of the lateral marginal vein was performed. RESULTS: Surgical treatment resulted in very good functional and aesthetic results. Follow-up at 26 months showed no evidence of varicose vein recurrence. CONCLUSIONS: To achieve good results, surgical intervention may be indicated in cases of orthopedic deformity, hemorrhage, symptomatic, and unaesthetic lesions.

  14. Titan's hydrodynamically escaping atmosphere

    Science.gov (United States)

    Strobel, Darrell F.

    2008-02-01

    The upper atmosphere of Titan is currently losing mass at a rate ˜(4-5)×10 amus, by hydrodynamic escape as a high density, slow outward expansion driven principally by solar UV heating by CH 4 absorption. The hydrodynamic mass loss is essentially CH 4 and H 2 escape. Their combined escape rates are restricted by power limitations from attaining their limiting rates (and limiting fluxes). Hence they must exhibit gravitational diffusive separation in the upper atmosphere with increasing mixing ratios to eventually become major constituents in the exosphere. A theoretical model with solar EUV heating by N 2 absorption balanced by HCN rotational line cooling in the upper thermosphere yields densities and temperatures consistent with the Huygens Atmospheric Science Investigation (HASI) data [Fulchignoni, M., and 42 colleagues, 2005. Nature 438, 785-791], with a peak temperature of ˜185-190 K between 3500-3550 km. This model implies hydrodynamic escape rates of ˜2×10 CHs and 5×10 Hs, or some other combination with a higher H 2 escape flux, much closer to its limiting value, at the expense of a slightly lower CH 4 escape rate. Nonthermal escape processes are not required to account for the loss rates of CH 4 and H 2, inferred by the Cassini Ion Neutral Mass Spectrometer (INMS) measurements [Yelle, R.V., Borggren, N., de la Haye, V., Kasprzak, W.T., Niemann, H.B., Müller-Wodarg, I., Waite Jr., J.H., 2006. Icarus 182, 567-576].

  15. How to fake hydrodynamic signals

    Energy Technology Data Exchange (ETDEWEB)

    Romatschke, Paul [Department of Physics, 390 UCB, University of Colorado at Boulder, Boulder, CO (United States); Center for Theory of Quantum Matter, University of Colorado, Boulder, CO 80309 (United States)

    2016-12-15

    Flow signatures in experimental data from relativistic ion collisions, are usually interpreted as a fingerprint of the presence of a hydrodynamic phase during the evolution of these systems. I review some theoretical ideas to ‘fake’ this hydrodynamic behavior in p+A and A+A collisions. I find that transverse flow and femtoscopic measurements can easily be forged through non-hydrodynamic evolution, while large elliptic flow requires some non-vanishing interactions in the hot phase.

  16. Modeling hydrodynamic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.S.; Pandit, A.B. [Mumbai Univ. (India). Chemical Engineering Div.

    1999-12-01

    Cavitation as a source and method of energy input for chemical processing is increasingly studied due to its ability to generate localized high temperatures and pressures under nearly ambient conditions. Compared to cavitation generated by ultrasound, hydrodynamic cavitation has been proved to be a very energy-efficient alternative. A simple and unified model has been developed to study the cavitation phenomena in hydraulic systems with emphasis on the venturi tube and high-speed homogenizer. The model has been found to be satisfactory in explaining the effect of operating variables and equipment geometry on two different modes of cavitation generation qualitatively and in some cases quantitatively. (orig.)

  17. Hydrodynamics of Ship Propellers

    DEFF Research Database (Denmark)

    Breslin, John P.; Andersen, Poul

    This book deals with flows over propellers operating behind ships, and the hydrodynamic forces and moments which the propeller generates on the shaft and on the ship hull.The first part of the text is devoted to fundamentals of the flow about hydrofoil sections (with and without cavitation...... of an intermittently cavitating propeller in a wake and the pressures and forces it exerts on the shaft and on the ship hull is examined. A final chapter discusses the optimization of efficiency of compound propulsors. The authors have taken care to clearly describe physical concepts and mathematical steps. Appendices...

  18. Foundations of radiation hydrodynamics

    CERN Document Server

    Mihalas, Dimitri

    1999-01-01

    Radiation hydrodynamics is a broad subject that cuts across many disciplines in physics and astronomy: fluid dynamics, thermodynamics, statistical mechanics, kinetic theory, and radiative transfer, among others. The theory developed in this book by two specialists in the field can be applied to the study of such diverse astrophysical phenomena as stellar winds, supernova explosions, and the initial phases of cosmic expansion, as well as the physics of laser fusion and reentry vehicles. As such, it provides students with the basic tools for research on radiating flows.Largely self-contained,

  19. A case of deep vein thrombosis with postthrombotic syndrome cured by homoeopathic therapy

    Directory of Open Access Journals (Sweden)

    Gyandas G Wadhwani

    2015-01-01

    Full Text Available A 46-year-old woman consulted for right-sided deep vein thrombosis in external iliac, common femoral, superficial femoral and popliteal veins with extension along with postthrombotic syndrome. After homoeopathic consultation, she was prescribed Argentum nitricum in ascending LM potencies. Symptomatic relief was reported within 2 weeks of treatment, and gradually the quality of life improved after simultaneous reduction in pain due to other complaints of sciatica and osteoarthrosis. Venous Doppler studies repeated a year later showed complete resolution of the medical condition with homoeopathic drug therapy alone. The physical examination also revealed a reduction in limb circumference.

  20. The use of expanded microporous polytetrafluoroethylene for limb salvage: a preliminary report.

    Science.gov (United States)

    Campbell, C D; Brooks, D H; Webster, M W; Bahnson, H T

    1976-05-01

    Initial laboratory and clinical evaluations of a new prosthetic material, expanded microporous polytetrafluoroethylene (PTFE), for small vessel replacement is promising and encourages further clinical trial. Frequently the autogenous saphenous vein is not available for bypass procedures, and alternative arterial substitutes have not proved reliable for replacement of small vessels. In this study, 15 patients with impending loss of limb and no available saphenous vein underwent revascularization of the lower extremity with expanded microporous PTFE grafts. Thirteen of 15 patients now demonstrate viable extremities with a resulting over-all early patency and limb salvage rate of 87 percent for this series. Follow-up ranges from one to 8 months. Seven patients had diabetes mellitus and eight had atherosclerotic heart disease. Nine grafts crossed the knee joint. In all patients arterial runoff was poor. Six patients had previous femoropopliteal bypasses, five with autogenous veins and one with Dacron velour. Two patients had multiple previous operations that failed, first with autogenous vein and later with fabric grafts. The current limb salvage and patency rate of 87 percent in high-risk patients suggests that expanded PTFE may be the prosthesis of choice when an autogenous vein is not available and possibly an equally good substitute when the venous autograft is available.

  1. Nanoscale hydrodynamics near solids

    Science.gov (United States)

    Camargo, Diego; de la Torre, J. A.; Duque-Zumajo, D.; Español, Pep; Delgado-Buscalioni, Rafael; Chejne, Farid

    2018-02-01

    Density Functional Theory (DFT) is a successful and well-established theory for the study of the structure of simple and complex fluids at equilibrium. The theory has been generalized to dynamical situations when the underlying dynamics is diffusive as in, for example, colloidal systems. However, there is no such a clear foundation for Dynamic DFT (DDFT) for the case of simple fluids in contact with solid walls. In this work, we derive DDFT for simple fluids by including not only the mass density field but also the momentum density field of the fluid. The standard projection operator method based on the Kawasaki-Gunton operator is used for deriving the equations for the average value of these fields. The solid is described as featureless under the assumption that all the internal degrees of freedom of the solid relax much faster than those of the fluid (solid elasticity is irrelevant). The fluid moves according to a set of non-local hydrodynamic equations that include explicitly the forces due to the solid. These forces are of two types, reversible forces emerging from the free energy density functional, and accounting for impenetrability of the solid, and irreversible forces that involve the velocity of both the fluid and the solid. These forces are localized in the vicinity of the solid surface. The resulting hydrodynamic equations should allow one to study dynamical regimes of simple fluids in contact with solid objects in isothermal situations.

  2. Anisotropic nonequilibrium hydrodynamic attractor

    Science.gov (United States)

    Strickland, Michael; Noronha, Jorge; Denicol, Gabriel S.

    2018-02-01

    We determine the dynamical attractors associated with anisotropic hydrodynamics (aHydro) and the DNMR equations for a 0 +1 d conformal system using kinetic theory in the relaxation time approximation. We compare our results to the nonequilibrium attractor obtained from the exact solution of the 0 +1 d conformal Boltzmann equation, the Navier-Stokes theory, and the second-order Mueller-Israel-Stewart theory. We demonstrate that the aHydro attractor equation resums an infinite number of terms in the inverse Reynolds number. The resulting resummed aHydro attractor possesses a positive longitudinal-to-transverse pressure ratio and is virtually indistinguishable from the exact attractor. This suggests that an optimized hydrodynamic treatment of kinetic theory involves a resummation not only in gradients (Knudsen number) but also in the inverse Reynolds number. We also demonstrate that the DNMR result provides a better approximation of the exact kinetic theory attractor than the Mueller-Israel-Stewart theory. Finally, we introduce a new method for obtaining approximate aHydro equations which relies solely on an expansion in the inverse Reynolds number. We then carry this expansion out to the third order, and compare these third-order results to the exact kinetic theory solution.

  3. Load responsive hydrodynamic bearing

    Science.gov (United States)

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  4. Adrenal vein catheterization. Anatomic considerations

    Energy Technology Data Exchange (ETDEWEB)

    El-Sherief, M.A. (Akademiska Sjukhuset, Uppsala (Sweden))

    1982-01-01

    Twenty post-mortem specimens and 93 phlebographies (56 right side, 37 left side) from 44 patients were investigated with respect to the adrenal venous anatomy. At autopsy, the venous orifices displayed in the area of adrenal drainage were injected bilaterally to identify the adrenal vein(s), the surrounding channels and the presence of interconnections. The findings were correlated with those at clinical phlebography, and the different sources of error were elicited. These were mainly found on the right side. Some guidelines are suggested in the hope that these will contribute to eliminate misconceptions.

  5. Deep Vein Thrombosis as Initial Manifestation of Whipple Disease

    Directory of Open Access Journals (Sweden)

    Mônica Souza de Miranda Henriques

    2016-11-01

    Full Text Available Introduction: Wipple disease (WD is a rare chronic disease caused by the bacillus Tropheryma whipplei. Constitutive, rheumatologic, gastrointestinal, cardiac, cerebral, lymphatic, cutaneous, and ophthalmological signs are possible systemic symptoms. However, thrombotic manifestations are rarely described as “stroke-like syndrome” or arterial thrombosis. Diagnosis is based on clinical manifestations and pathological examination. Laboratory findings may include anemia, leukocytosis, and thrombocytosis. Objective: We report a case of venous thrombosis as initial manifestation of WD. Case Report: We describe the case of a 53-year-old male with iliofemoral vein thrombosis followed by intermittent diarrhea, loss of appetite, abdominal distension, and bloating. A mild malnutrition state with a weight loss of 13 kg, pallor (+/4 +, presence of lower-limb edema (+/4 +, and hypertympanic distended abdomen occurred. Laboratory tests on admission revealed anemia, positive inflammatory activity tests, and normal coagulation. Endoscopic examination showed villous edema with white dotted infiltrates in the second duodenal portion and intestinal lymphangiectasia in the terminal ileum. Pathological examination revealed numerous macrophages with positive periodic acid-Schiff inclusions. Venous Doppler ultrasound showed extensive deep thrombosis on the left lower limb and recanalization of the femoral vein in the right lower limb. The patient was treated with ceftriaxone and enoxaparin sodium, which led to an improvement of gastrointestinal and thrombosis symptoms. Comments: Hypercoagulability, endothelial damage, vasculitis, and blood stasis are present in T. whipplei infection, which are associated with the activation of inflammatory mechanisms as well as procoagulant and thromboembolic events. WD should be part of the differential diagnosis of diseases that cause venous thrombosis of unknown origin.

  6. Hydrodynamic Forces on Composite Structures

    Science.gov (United States)

    2014-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited HYDRODYNAMIC ...Thesis 4. TITLE AND SUBTITLE HYDRODYNAMIC FORCES ON COMPOSITE STRUCTURES 5. FUNDING NUMBERS 6. AUTHOR(S) Scott C. Millhouse 7. PERFORMING...angles yields different free surface effects including vortices and the onset of cavitation . 14. SUBJECT TERMS Fluid structure interaction, FSI, finite

  7. Black brane entropy and hydrodynamics

    NARCIS (Netherlands)

    Booth, I.; Heller, M.P.; Spaliński, M.

    2010-01-01

    A generalization of entropy to near-equilibrium phenomena is provided by the notion of a hydrodynamic entropy current. Recent advances in holography have lead to the formulation of fluid-gravity duality, a remarkable connection between the hydrodynamics of certain strongly coupled media and dynamics

  8. Black brane entropy and hydrodynamics

    NARCIS (Netherlands)

    Booth, I.; Heller, M.P.; Spaliński, M.

    2011-01-01

    A generalization of entropy to near-equilibrium phenomena is provided by the notion of a hydrodynamic entropy current. Recent advances in holography have lead to the formulation of fluid-gravity duality, a remarkable connection between the hydrodynamics of certain strongly coupled media and dynamics

  9. A hydrodynamic formalism for Brownian systems

    International Nuclear Information System (INIS)

    Pina, E.; Rosales, M.A.

    1981-01-01

    A formal hydrodynamic approach to Brownian motion is presented and the corresponding equations are derived. Hydrodynamic quantities are expressed in terms of the physical variables characterizing the Brownian systems. Contact is made with the hydrodynamic model of Quantum Mechanics. (author)

  10. Limb salvage surgery.

    Science.gov (United States)

    Kadam, Dinesh

    2013-05-01

    The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy.

  11. Limb salvage surgery

    Directory of Open Access Journals (Sweden)

    Dinesh Kadam

    2013-01-01

    Full Text Available The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy.

  12. CT findings of portal vein aneurysm

    International Nuclear Information System (INIS)

    Yang, Dal Mo; Chang, Mi Son; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Hyo Sun; Chung, Jin Woo

    1999-01-01

    To describe the CT findings of portal vein aneurysm in eight patients. All patients included in this study (two men and six women) underwent CT examinations between October 1996 and June1998. Of these eight, three were suffering from hepatic disease and portal hypertension. We determined the location, shape, size, and characteristics of the lesions, and the presence or absence of portal vein anomaly. Seven patients had intrahepatic portal vein aneurysm (at the umbilical portion of the left portal vein in five patients, between the transverse and umbilical portion of the left portal vein in one, and at the bifurcation of the anterior and posterior branch of the right portal vein in one), while extrahepatic portal vein aneurysm, at the confluence of the superior mesenteric and splenic vein was found in only one. Lesions were cyst-shaped in seven cases and saccular in one, and showed well-circumscribed, markedly enhanced mass, which communicated with the portal vein and/or gives off major branches. Portal vein anomaly, in which the right anterior segmental portal vein originated from the umbilical portion of the left portal vein, was seen in three patients. In all three, intrahepatic portal vein aneurysm was present at the umbilical portion of the left portal vein, and in one, the umbilical protion of the left portal vein was located to the right of the Cantlic line. CT examination can help reveal portal vein aneurysm by detecting a well-circumscribed, markedly enhanced mass which communicates with the portal vein and/or gives off major branches

  13. Foundations of radiation hydrodynamics

    Science.gov (United States)

    Mihalas, D.; Mihalas, B. W.

    This book is the result of an attempt, over the past few years, to gather the basic tools required to do research on radiating flows in astrophysics. The microphysics of gases is discussed, taking into account the equation of state of a perfect gas, the first and second law of thermodynamics, the thermal properties of a perfect gas, the distribution function and Boltzmann's equation, the collision integral, the Maxwellian velocity distribution, Boltzmann's H-theorem, the time of relaxation, and aspects of classical statistical mechanics. Other subjects explored are related to the dynamics of ideal fluids, the dynamics of viscous and heat-conducting fluids, relativistic fluid flow, waves, shocks, winds, radiation and radiative transfer, the equations of radiation hydrodynamics, and radiating flows. Attention is given to small-amplitude disturbances, nonlinear flows, the interaction of radiation and matter, the solution of the transfer equation, acoustic waves, acoustic-gravity waves, basic concepts of special relativity, and equations of motion and energy.

  14. From TDHF to hydrodynamics

    International Nuclear Information System (INIS)

    Koehler, H.S.

    1983-01-01

    The Time-Dependent Hartree-Fock theory provides a microscopic approach to the scattering of heavy ions. Fundamental in this theory is a mean-(one-body) field. The calculation of this field from a two-body effective interaction makes the theory microscopic. Many-body effects are included by the Brueckner definition of this interaction; the reaction-matrix. In excited media it is in general complex allowing for decays. The imaginary part relates directly to the collision-term in a transport equation. We treat this term by the time-relaxation-method. This implies an extension of the TDHF-equation to include two-body collisions. Hydrodynamic equations are derived from this new equation. The solution of the two equations agree quantitatively for short-relaxation-times. Relaxation-times are calculated as a function of temperature. (orig.)

  15. Hydrodynamics of Peristaltic Propulsion

    Science.gov (United States)

    Athanassiadis, Athanasios; Hart, Douglas

    2014-11-01

    A curious class of animals called salps live in marine environments and self-propel by ejecting vortex rings much like jellyfish and squid. However, unlike other jetting creatures that siphon and eject water from one side of their body, salps produce vortex rings by pumping water through siphons on opposite ends of their hollow cylindrical bodies. In the simplest cases, it seems like some species of salp can successfully move by contracting just two siphons connected by an elastic body. When thought of as a chain of timed contractions, salp propulsion is reminiscent of peristaltic pumping applied to marine locomotion. Inspired by salps, we investigate the hydrodynamics of peristaltic propulsion, focusing on the scaling relationships that determine flow rate, thrust production, and energy usage in a model system. We discuss possible actuation methods for a model peristaltic vehicle, considering both the material and geometrical requirements for such a system.

  16. Hydrodynamic effects on coalescence.

    Energy Technology Data Exchange (ETDEWEB)

    Dimiduk, Thomas G.; Bourdon, Christopher Jay; Grillet, Anne Mary; Baer, Thomas A.; de Boer, Maarten Pieter; Loewenberg, Michael (Yale University, New Haven, CT); Gorby, Allen D.; Brooks, Carlton, F.

    2006-10-01

    The goal of this project was to design, build and test novel diagnostics to probe the effect of hydrodynamic forces on coalescence dynamics. Our investigation focused on how a drop coalesces onto a flat surface which is analogous to two drops coalescing, but more amenable to precise experimental measurements. We designed and built a flow cell to create an axisymmetric compression flow which brings a drop onto a flat surface. A computer-controlled system manipulates the flow to steer the drop and maintain a symmetric flow. Particle image velocimetry was performed to confirm that the control system was delivering a well conditioned flow. To examine the dynamics of the coalescence, we implemented an interferometry capability to measure the drainage of the thin film between the drop and the surface during the coalescence process. A semi-automated analysis routine was developed which converts the dynamic interferogram series into drop shape evolution data.

  17. Straight configuration saphenous vein transposition to popliteal artery for vascular access.

    Science.gov (United States)

    Caco, Gentian; Golemi, Dhurata; Likaj, Eriola

    2017-03-21

    The saphenous vein is commonly used as a vascular graft in peripheral artery surgery but rarely used for vascular access. The literature on straight configuration saphenous vein transposition to the popliteal artery is scarce. Here we present two cases of straight configuration saphenous vein transposition to the popliteal artery for vascular access, the surgical technique and respective follow-up. Two young men, aged 29 and 36 years, were chosen for lower-limb vascular access for hemodialysis. The first patient was paraplegic since birth. He used his arms to move so upper extremity vascular access was avoided. The second patient presented with an infected upper extremity arteriovenous graft (AVG) and after multiple closed AVFs he had no more available arm veins. Both patients received autologous lower extremity straight configuration saphenous vein transpositions to the popliteal artery under spinal anesthesia in May and October 2012, respectively. Cannulation of the fistula was allowed after one month. There were no early complications. Slight swelling on the leg appeared in one of the patients. Both fistulas were still functional after 36 and 32 months, respectively. The straight configuration saphenous vein transposition to popliteal artery is simple to perform, offers a long and straight segment for cannulation and may be a suitable autologous vascular access in selected patients.

  18. The technique advantages of 16-detector multic-slice spiral CT in evaluating combined pulmonary and deep vein thromboembolism

    International Nuclear Information System (INIS)

    Xia Shuang; Qi Ji; Lei Xinwei; Wen Lianqing; Li Yiming; Liu Jisheng

    2004-01-01

    Objective: To study the scanning technique of 16-detector multic-slice spiral CT(MSCT) for combined pulmonary artery and deep vein of lower limb in pulmonary thromboembolism (PE) patients. Methods: Forty suspected pulmonary thromboembolism patients were performed both pulmonary artery angiography (CTA) and indirect deep vein venography (CTV) on 16-detector MSCT. The parameters of the latter as following: total contrast volume 120-150 ml, injection rate 4.0-4.5 ml/s (from antecubital vein), delay time 4.0 for CTA 20-23 s, CTV 120-180 s, collimation for CTA 1.25 mm and 0.625 mm, CTV 2.5 mm, scan range of CTV: from popliteal vein to the level of bilateral renal vein into the inferior vena cava. Postprocessing include MPR, MIP, and VR. The test was used to analyzed the images. Results: Twenty five patients had both pulmonary thromboembolism (PE) and deep vein thromboembolism (DVT), 8 patients had only DVT, 2 had only PE, and 5 had neither. There was no difference between different collimation in depicting thrombus. The CT value number of enhanced pulmonary artery and lower deep vein was obviously higher than the thrombus. The value of MPR, MIP, VR for PE was 100%, 100%, and 65%, The value of MPR, MIP, VR for DVT is 100%, 60%, and 50%. Conclusion: The technique of combined pulmonary CTA and deep vein CTV of 16-detector MSCT will provide a new modality for pulmonary thromboembolism patients. (author)

  19. Congestive index of portal vein

    International Nuclear Information System (INIS)

    Kim, Won Ho; Kim, H. K.; Lee, S. C.; Han, S. H.; Han, K. H.; Chung, J. B.; Choi, H. J.

    1989-01-01

    In patients with portal hypertension, the blood flow volume is maintained despite decreased blood flow velocity due to enlargement of the vascular cross sectional area. Thus, the 'congestion index' of the portal vein, which is the ratio between the cross sectional area (cm2) and the blood flow velocity (cm/sec) determined by a Doppler ultrasonography, may be a sensitive index by which to assess portal hypertension. We performed Doppler ultrasonography on 24 normal subjects, 14 patients with biopsy proved chronic active hepatitis and 55 patients with liver cirrhosis in order to assess the diagnostic value of the congestion index. The cross sectional area of the portal vein was significantly enlarged and the mean blood flow velocity was significantly reduced in patients with liver cirrhosis compared with controls. However, the blood flow volume was no difference. The congestion index of the portal vein was significantly increased in patients with liver cirrhosis (0.113+0.035) compared with patients with chronic active hepatitis(0.078+0.029) (p<0.001) and controls (0.053+0.016) (p<0.001). The sensitivity, specificity and predictability of the congestion index for detection of patients with the cirrhosis of the liver were 76.4%, 100% and 100% respectively, when the normal range was set at mean+2SD. The results suggest that the congestion index of the portal vein may pla a significant role in diagnosis of portal hypertensive patients

  20. Kinetics of vein graft hyperplasia

    International Nuclear Information System (INIS)

    Zwolak, R.M.; Adams, M.C.; Clowes, A.W.

    1986-01-01

    Human aortocoronary vein grafts fail due to accelerated occlusive disease. The possibility that this is related to cellular hyperplasia was investigated in a rabbit model where kinetics of vein graft thickening, endothelial (EC) repair, and smooth muscle cell (SMC) proliferation were measured from 2 days to 24 weeks after implanting jugular vein segments in the carotid artery. Immediately after graft placement focal EC denudation was observed. These defects were repaired within 1 week and did not recur. By 4 weeks intimal area had increased 30 fold from 0.028 +/- 0.004 to 0.705 +/- 0.021 mm 2 , and a 24 weeks was 0.93 +/- 0.21 mm 2 . This response did not produce a reduction in graft lumen area. EC and SMC thymidine-labeling index were measured by en face and cross-section autoradiography after injection of 3 H-thymidine and perfusion fixation. Despite rapid EC surface repair EC labeling index remained elevated and only returned to normal levels at 12 weeks; SMC labeling was 10 fold greater than baseline even at 24 weeks (0.22% vs 0.02%). SMC mass demonstrated morphometrically increased between 2 and 12 weeks. Intimal thickening in vein grafts is due to SMC proliferation and develops after the EC layer has been restored. In contrast, intimal SMC proliferate in damaged arteries when the EC layer is absent and cease when the EC layer is regenerated

  1. [The use of labelled albumin microspheres in the study of arteriovenous shunting in varicosities of the lower limbs (author's transl)].

    Science.gov (United States)

    Serise, J M; Le Héron, D; Le Héron, G; Bonnet, A; Busquet, J; Basse-Cathalinat, B; Tingaud, R

    1982-01-01

    The greater proportion of oxygen in the blood circulating in veins of the lower limbs bought to attention the possibility of pre-capillary arteriovenous shunting. The intra-arteriel injection of Technetium labelled serum albumin microspheres enables one to quantify arteriovenous shunts greater than 25 microns. The authors made a comparative study of arterio-venous shunting by blood gases analysis and isotopic techniques in twenty patients. The results seem to deny the existence of arteriovenous shunts in the genesis of essential varicose veins in the lower limb.

  2. Isolated limb perfusion.

    Science.gov (United States)

    Gillespie, Rosalyn; Chantier, Nariane

    1994-12-08

    Growing concern over the rising incidence of malignant melanoma has brought about a need for information on this disorder and the treatment available. Isolated limb perfusion is a relatively new technique used in only a few hospitals. An increased knowledge base will lead to a better understanding of the nursing care required and to a more in-depth care plan.

  3. Hydrodynamic cavitation for sonochemical effects.

    Science.gov (United States)

    Moholkar, V S; Kumar, P S; Pandit, A B

    1999-03-01

    A comparative study of hydrodynamic and acoustic cavitation has been made on the basis of numerical solutions of the Rayleigh-Plesset equation. The bubble/cavity behaviour has been studied under both acoustic and hydrodynamic cavitation conditions. The effect of varying pressure fields on the collapse of the cavity (sinusoidal for acoustic and linear for hydrodynamic) and also on the latter's dynamic behaviour has been studied. The variations of parameters such as initial cavity size, intensity of the acoustic field and irradiation frequency in the case of acoustic cavitation, and initial cavity size, final recovery pressure and time for pressure recovery in the case of hydrodynamic cavitation, have been found to have significant effects on cavity/bubble dynamics. The simulations reveal that the bubble/cavity collapsing behaviour in the case of hydrodynamic cavitation is accompanied by a large number of pressure pulses of relatively smaller magnitude, compared with just one or two pulses under acoustic cavitation. It has been shown that hydrodynamic cavitation offers greater control over operating parameters and the resultant cavitation intensity. Finally, a brief summary of the experimental results on the oxidation of aqueous KI solution with a hydrodynamic cavitation set-up is given which supports the conclusion of this numerical study. The methodology presented allows one to manipulate and optimise of specific process, either physical or chemical.

  4. Catheter-Directed Thrombolysis via Small Saphenous Veins for Treating Acute Deep Venous Thrombosis.

    Science.gov (United States)

    Yang, Bin; Xu, Xiao-Dong; Gao, Peng; Yu, Ji-Xiang; Li, Yu; Zhu, Ai-Dong; Meng, Ran-Ran

    2016-08-23

    BACKGROUND There is little data comparing catheter-directed thrombolysis (CDT) via small saphenous veins vs. systematic thrombolysis on complications and efficacy in acute deep venous thrombosis patients. The aim of our study was to compare the efficacy and safety of CDT via the small saphenous veins with systematic thrombolysis for patients with acute deep venous thrombosis (DVT). MATERIAL AND METHODS Sixty-six patients with acute DVT admitted from June 2012 to December 2013 were divided into 2 groups: 27 patients received systemic thrombolysis (ST group) and 39 patients received CDT via the small saphenous veins (CDT group). The thrombolysis efficiency, limb circumference differences, and complications such as post-thrombotic syndrome (PTS) in the 2 groups were recorded. RESULTS The angiograms demonstrated that all or part of the fresh thrombus was dissolved. There was a significant difference regarding thrombolysis efficiency between the CDT group and ST group (71.26% vs. 48.26%, P=0.001). In both groups the postoperative limb circumference changes were higher compared to the preoperative values. The differences between postoperative limb circumferences on postoperative days 7 and 14 were significantly higher in the CDT group than in the ST group (all Pdeep venous thrombosis.

  5. Effect of a venotonic agent on the main arteries and veins during a 5 day HDT

    Science.gov (United States)

    Roumy, Jerome; Herault, Stephane; Tobal, Nathalie; Besnard, Stephane; Arbeille, Philippe

    2001-08-01

    Objective: To evaluate the cardiac, arterial and venous effect of a venotonic drug (Cirkan « Ck å) administrated orally daily to 6 subjects in HDT position during 5 days. These subjects underwent a second 5d HDT without Ck treatment one month later. Pre and post HDT the subjects were submitted to a stand test. Method: The cardiovascular parameters were measured by echography and Doppler. Results and discussion: The Cirkan treatment contributed to reduce the increase in cerebral resistance, and to maintain the lower limb resistance at a higher level than on controls. It reduces the vein section at the extremities (Jugular, femoral) and in the central vein system connected to the right heart (sub hepatics). On the other hand it increases the portal vein section which means that the blood stagnation at the splanchnic level is increased. Despite these arterial and venous significant modifications the clinical and ECG and Blood pressure response to the Stand test was similar in both groups.

  6. Surgical Access to Jejunal Veins for Local Thrombolysis and Stent Placement in Portal Vein Thrombosis

    International Nuclear Information System (INIS)

    Schellhammer, Frank; Esch, Jan Schulte am; Hammerschlag, Sascha; Knoefel, Wolfram Trudo; Fuerst, Guenter

    2008-01-01

    Portal vein thrombosis is an infrequent entity, which may cause high morbidity and mortality. We report a case of portal vein thrombosis due to benign stenosis following partial pancreatoduodenectomy with segmental replacement of the portal vein by a Gore-tex graft. Using a surgical access to jenunal veins, local thrombolysis, mechanical fragmentation of thrombus, and stent placement were successfully performed.

  7. Preoperative mapping of the saphenous vein

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Sillesen, H; Nielsen, Tina G

    1995-01-01

    A consecutive series of 92 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. A naturally occurring optimal vein diameter was discovered. It was significantly correlated with higher postoperative ankle-brachial pres......-brachial pressure index (ABI) and lesser early postoperative thrombosis. A significant linear regression was found between the pre and postoperative vein diameter....

  8. Recent development of hydrodynamic modeling

    Science.gov (United States)

    Hirano, Tetsufumi

    2014-09-01

    In this talk, I give an overview of recent development in hydrodynamic modeling of high-energy nuclear collisions. First, I briefly discuss about current situation of hydrodynamic modeling by showing results from the integrated dynamical approach in which Monte-Carlo calculation of initial conditions, quark-gluon fluid dynamics and hadronic cascading are combined. In particular, I focus on rescattering effects of strange hadrons on final observables. Next I highlight three topics in recent development in hydrodynamic modeling. These include (1) medium response to jet propagation in di-jet asymmetric events, (2) causal hydrodynamic fluctuation and its application to Bjorken expansion and (3) chiral magnetic wave from anomalous hydrodynamic simulations. (1) Recent CMS data suggest the existence of QGP response to propagation of jets. To investigate this phenomenon, we solve hydrodynamic equations with source term which exhibits deposition of energy and momentum from jets. We find a large number of low momentum particles are emitted at large angle from jet axis. This gives a novel interpretation of the CMS data. (2) It has been claimed that a matter created even in p-p/p-A collisions may behave like a fluid. However, fluctuation effects would be important in such a small system. We formulate relativistic fluctuating hydrodynamics and apply it to Bjorken expansion. We found the final multiplicity fluctuates around the mean value even if initial condition is fixed. This effect is relatively important in peripheral A-A collisions and p-p/p-A collisions. (3) Anomalous transport of the quark-gluon fluid is predicted when extremely high magnetic field is applied. We investigate this possibility by solving anomalous hydrodynamic equations. We found the difference of the elliptic flow parameter between positive and negative particles appears due to the chiral magnetic wave. Finally, I provide some personal perspective of hydrodynamic modeling of high energy nuclear collisions

  9. SPECIAL RELATIVISTIC HYDRODYNAMICS WITH GRAVITATION

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu (Korea, Republic of); Noh, Hyerim [Korea Astronomy and Space Science Institute, Daejon (Korea, Republic of)

    2016-12-20

    Special relativistic hydrodynamics with weak gravity has hitherto been unknown in the literature. Whether such an asymmetric combination is possible has been unclear. Here, the hydrodynamic equations with Poisson-type gravity, considering fully relativistic velocity and pressure under the weak gravity and the action-at-a-distance limit, are consistently derived from Einstein’s theory of general relativity. An analysis is made in the maximal slicing, where the Poisson’s equation becomes much simpler than our previous study in the zero-shear gauge. Also presented is the hydrodynamic equations in the first post-Newtonian approximation, now under the general hypersurface condition. Our formulation includes the anisotropic stress.

  10. Similarity flows in relativistic hydrodynamics

    International Nuclear Information System (INIS)

    Blaizot, J.P.; Ollitrault, J.Y.

    1986-01-01

    In ultra-relativistic heavy ion collisions, one expects in particular to observe a deconfinement transition leading to a formation of quark gluon plasma. In the framework of the hydrodynamic model, experimental signatures of such a plasma may be looked for as observable consequences of a first order transition on the evolution of the system. In most of the possible scenario, the phase transition is accompanied with discontinuities in the hydrodynamic flow, such as shock waves. The method presented in this paper has been developed to treat without too much numerical effort such discontinuous flow. It relies heavily on the use of similarity solutions of the hydrodynamic equations

  11. Collateral veins in inferior caval vein occlusion demonstrated via CT

    International Nuclear Information System (INIS)

    Lien, H.H.; Lund, G.

    1983-01-01

    CT-scans of 12 patients with tumour-induced occlusion of the inferior vena cava were studied with regard to collateral veins. A comparison was performed with findings at phlebography in 10 patients and at autopsy in 2. The site and appearance of the main collateral pathway are presented. A close study of vascular structures renders useful information on collateral circulation in occlusion of the inferior vena cava. (orig.)

  12. Recurrence of superficial vein thrombosis in patients with varicose veins.

    Science.gov (United States)

    Karathanos, Christos; Spanos, Konstantinos; Saleptsis, Vassileios; Tsezou, Aspasia; Kyriakou, Despina; Giannoukas, Athanasios D

    2016-08-01

    To investigate which factors other than history of superficial vein thrombosis (SVT) are associated with recurrent spontaneous SVT episodes in patients with varicose veins (VVs). Patients with a history of spontaneous SVT and VVs were followed up for a mean period of 55 months. Demographics, comorbidities, and thrombophilia screening test were analyzed. Patients were grouped according to the clinical-etiology-anatomy-pathophysiology classification. A multiple logistic regression analysis with the forward likelihood ratio method was undertaken. Thirteen patients out of 97 had a recurrence SVT episode during the follow-up period. All those patients were identified to have a thrombophilia defect. Protein C and S, antithrombin, and plasminogen deficiencies were more frequently present in patients without recurrence. Gene mutations were present in 38% in the nonrecurrence group and 77% in the recurrence group. After logistic regression analysis, patients with dislipidemia and mutation in prothrombin G20210A (FII) had an increased risk for recurrence by 5.4-fold and 4.6-fold, respectively. No deep vein thrombosis or pulmonary embolism occurred. Dislipidemia and gene mutations of F II are associated with SVT recurrence in patients with VVs. A selection of patients may benefit from anticoagulation in the short term and from VVs intervention in the long term. © The Author(s) 2015.

  13. Upper limb joint forces and moments during underwater cyclical movements.

    Science.gov (United States)

    Lauer, Jessy; Rouard, Annie Hélène; Vilas-Boas, João Paulo

    2016-10-03

    Sound inverse dynamics modeling is lacking in aquatic locomotion research because of the difficulty in measuring hydrodynamic forces in dynamic conditions. Here we report the successful implementation and validation of an innovative methodology crossing new computational fluid dynamics and inverse dynamics techniques to quantify upper limb joint forces and moments while moving in water. Upper limb kinematics of seven male swimmers sculling while ballasted with 4kg was recorded through underwater motion capture. Together with body scans, segment inertial properties, and hydrodynamic resistances computed from a unique dynamic mesh algorithm capable to handle large body deformations, these data were fed into an inverse dynamics model to solve for joint kinetics. Simulation validity was assessed by comparing the impulse produced by the arms, calculated by integrating vertical forces over a stroke period, to the net theoretical impulse of buoyancy and ballast forces. A resulting gap of 1.2±3.5% provided confidence in the results. Upper limb joint load was within 5% of swimmer׳s body weight, which tends to supports the use of low-load aquatic exercises to reduce joint stress. We expect this significant methodological improvement to pave the way towards deeper insights into the mechanics of aquatic movement and the establishment of practice guidelines in rehabilitation, fitness or swimming performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Blood sampling from adrenal gland vein

    International Nuclear Information System (INIS)

    Sun Yong; Ni Caifang

    2009-01-01

    Adrenal gland vein sampling is an interventional method to get the blood samples from the adrenal gland vein. The blood is obtained via a catheter which is selectively inserted in the adrenal gland vein. This technique is mainly used to be diagnostic for primary hyperaldosteronism. A full knowledge of the anatomy and variations of the adrenal gland vein, serious preoperative preparation and skilled catheterization manipulation are necessary for obtaining sufficient blood sample and for reducing the occurrence of complications. Providing the physicians with definite diagnostic evidence and being technically feasible, adrenal gland vein sampling should become one of the routine examinations for clarifying the cause of primary hyperaldosteronism. (authors)

  15. Lotic Water Hydrodynamic Model

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David Ryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tasseff, Byron Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-23

    Water-related natural disasters, for example, floods and droughts, are among the most frequent and costly natural hazards, both socially and economically. Many of these floods are a result of excess rainfall collecting in streams and rivers, and subsequently overtopping banks and flowing overland into urban environments. Floods can cause physical damage to critical infrastructure and present health risks through the spread of waterborne diseases. Los Alamos National Laboratory (LANL) has developed Lotic, a state-of-the-art surface water hydrodynamic model, to simulate propagation of flood waves originating from a variety of events. Lotic is a two-dimensional (2D) flood model that has been used primarily for simulations in which overland water flows are characterized by movement in two dimensions, such as flood waves expected from rainfall-runoff events, storm surge, and tsunamis. In 2013, LANL developers enhanced Lotic through several development efforts. These developments included enhancements to the 2D simulation engine, including numerical formulation, computational efficiency developments, and visualization. Stakeholders can use simulation results to estimate infrastructure damage and cascading consequences within other sets of infrastructure, as well as to inform the development of flood mitigation strategies.

  16. Hydrodynamics of rotating superfluids

    International Nuclear Information System (INIS)

    Chandler, E.A.

    1981-01-01

    In this thesis, a coarse grained hydrodynamics is developed from the exact description of Tkachenko. To account for the dynamics of the vortex lattice, the macroscopic vortex displacement field is treated as an independent degree of freedom. The conserved energy is written in terms of the coarse-grained normal fluid, superfluid, and vortex velocities and includes an elastic energy associated with deformations of the vortex lattice. Equations of motion consistent with the conservation of energy, entropy and vorticity and containing mutual friction terms arising from microscopic interactions between normal fluid excitations and the vortex lines are derived. When the vortex velocity is eliminated from the damping terms, this system of equations becomes essentially that of BK with added elastic terms in the momentum stress tensor and energy current. The dispersion relation and damping of the first and second sound modes and the two transverse modes sustained by the system are investigated. It is shown that mutual friction mixes the transverse modes of the normal and superfluid components and damps the transverse mode associated with the relative velocity of these components, making this wave evanescent in the plane perpendicular to the rotation axis. The wave associated with transverse motion of the total mass current is a generalized Tkachenko mode, whose dispersion relation reduces to that derived by Tkachenko wave when the wavevector lies in this plane

  17. Advanced in Macrostatistical Hydrodynamics

    International Nuclear Information System (INIS)

    Graham, A.L.; Tetlow, N.; Abbott, J.R.; Mondy, L.S.; Brenner, H.

    1993-01-01

    An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small (Macrostatistical Hydrodynamics). First, we describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. We suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. We also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, we briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about the microstructure and boundary effects in concentrated suspensions

  18. Engineering Hydrodynamic AUV Hulls

    Science.gov (United States)

    Allen, J.

    2016-12-01

    AUV stands for autonomous underwater vehicle. AUVs are used in oceanography and are similar to gliders. MBARIs AUVs as well as other AUVs map the ocean floor which is very important. They also measure physical characteristics of the water, such as temperature and salinity. My science fair project for 4th grade was a STEM activity in which I built and tested 3 different AUV bodies. I wanted to find out which design was the most hydrodynamic. I tested three different lengths of AUV hulls to see which AUV would glide the farthest. The first was 6 inches. The second was 12 inches and the third was 18 inches. I used clay for the nosecone and cut a ruler into two and made it the fin. Each AUV used the same nosecone and fin. I tested all three designs in a pool. I used biomimicry to create my hypothesis. When I was researching I found that long slim animals swim fastest. So, my hypothesis is the longer AUV will glide farthest. In the end I was right. The longer AUV did glide the farthest.

  19. Unusual termination of the right testicular vein | Woldeyes | Anatomy ...

    African Journals Online (AJOL)

    The testicular veins are formed by the veins emerging from the testis and epididymis forming the pampiniform venous plexus. The right testicular vein drains into inferior vena cava and the left testicular vein to the left renal vein. Testicular veins display a great variability with regard to their number, course and sites of ...

  20. Hydrodynamics of electrons in graphene

    Science.gov (United States)

    Lucas, Andrew; Chung Fong, Kin

    2018-02-01

    Generic interacting many-body quantum systems are believed to behave as classical fluids on long time and length scales. Due to rapid progress in growing exceptionally pure crystals, we are now able to experimentally observe this collective motion of electrons in solid-state systems, including graphene. We present a review of recent progress in understanding the hydrodynamic limit of electronic motion in graphene, written for physicists from diverse communities. We begin by discussing the ‘phase diagram’ of graphene, and the inevitable presence of impurities and phonons in experimental systems. We derive hydrodynamics, both from a phenomenological perspective and using kinetic theory. We then describe how hydrodynamic electron flow is visible in electronic transport measurements. Although we focus on graphene in this review, the broader framework naturally generalizes to other materials. We assume only basic knowledge of condensed matter physics, and no prior knowledge of hydrodynamics.

  1. The angiographic demonstration of hepatic vein obstruction

    International Nuclear Information System (INIS)

    Zu Maoheng; Xu Hao; Li Guojun; Gu Yuming; Wei Ning; Wang Cheng; Xu Wei

    2004-01-01

    Objective: To evaluate the angiographic feature of hepatic vein obstruction. Methods Forty-five patients (male 23, female 22, age 9-54 years) suffered from hepatic vein obstruction. The inferior vena cavography and the hepatic venography were performed in all cases. Results: IVC was free in 37 patients with hepatic vein obstruction, both IVC and HV were obstructed in 8 patients. The local or long stenosis of IVC was found in 31 inferior vena cavography. The diameter of IVC was normal in 12 patients. The sign of membranous dome was found in hepatic vein orifice in 5 cases and in accessory hepatic vein orifice in 4 cases. Intrahepatic venous collaterals were found in 45 cases. Conclusion: Hepatic vein obstruction can be reproached primarily in inferior vena cavography, the membranous dome is a direct sign of membranous obstruction of HV and AHV in inferior vena cavography. The selected hepatic venography can provide reliable evidence to diagnose hepatic vein obstruction

  2. Analytic approaches to relativistic hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hatta, Yoshitaka

    2016-12-15

    I summarize our recent work towards finding and utilizing analytic solutions of relativistic hydrodynamic. In the first part I discuss various exact solutions of the second-order conformal hydrodynamics. In the second part I compute flow harmonics v{sub n} analytically using the anisotropically deformed Gubser flow and discuss its dependence on n, p{sub T}, viscosity, the chemical potential and the charge.

  3. Hydrodynamic aspects of flotation separation

    Directory of Open Access Journals (Sweden)

    Peleka Efrosyni N.

    2016-01-01

    Full Text Available Flotation separation is mainly used for removing particulates from aqueous dispersions. It is widely used for ore beneficiation and recovering valuable materials. This paper reviews the hydrodynamics of flotation separations and comments on selected recent publications. Units are distinguished as cells of ideal and non-ideal flow. A brief introduction to hydrodynamics is included to explain an original study of the hybrid flotation-microfiltration cell, effective for heavy metal ion removal.

  4. An introduction to astrophysical hydrodynamics

    CERN Document Server

    Shore, Steven N

    1992-01-01

    This book is an introduction to astrophysical hydrodynamics for both astronomy and physics students. It provides a comprehensive and unified view of the general problems associated with fluids in a cosmic context, with a discussion of fluid dynamics and plasma physics. It is the only book on hydrodynamics that addresses the astrophysical context. Researchers and students will find this work to be an exceptional reference. Contents include chapters on irrotational and rotational flows, turbulence, magnetohydrodynamics, and instabilities.

  5. Vein-type uranium deposits

    International Nuclear Information System (INIS)

    Rich, R.A.; Holland, H.D.; Petersen, U.

    1975-01-01

    A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

  6. Tharsis Limb Cloud

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Annotated image of Tharsis Limb Cloud 7 September 2005 This composite of red and blue Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) daily global images acquired on 6 July 2005 shows an isolated water ice cloud extending more than 30 kilometers (more than 18 miles) above the martian surface. Clouds such as this are common in late spring over the terrain located southwest of the Arsia Mons volcano. Arsia Mons is the dark, oval feature near the limb, just to the left of the 'T' in the 'Tharsis Montes' label. The dark, nearly circular feature above the 'S' in 'Tharsis' is the volcano, Pavonis Mons, and the other dark circular feature, above and to the right of 's' in 'Montes,' is Ascraeus Mons. Illumination is from the left/lower left. Season: Northern Autumn/Southern Spring

  7. [Limb lengthening in dwarfism].

    Science.gov (United States)

    Correll, J; Held, P

    2000-09-01

    Limb lengthening in dwarfism has become a standardised procedure with a good prognosis. In most cases external fixation is used. Gain of leg length up to 15 cm and more is possible in the lower leg and the femur and 8.5 cm in the humerus. Limb lengthening is useful in many cases of dwarfism due to skeletal dysplasia. There are a number of risks and possible complications involved and the procedure also requires considerable time. We report the results of 48 patients with dwarfism operated on in the Orthopädische Kinderklinik Aschau (Orthopaedic Hospital for Children). It must not be recommended as a normal tool in handling the problems of dwarfism, but it makes sense in some cases of dwarfism. We describe and discuss the prerequisites for the operative treatment.

  8. Microwave solar limb brightening

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I A; Kundu, M R [Maryland Univ., College Park (USA)

    1981-02-01

    Previous models of microwave limb brightening have omitted the alignment of spicules along supergranule boundaries, have neglected the high temperature sheath around spicules, and have assumed an interspicular medium which was averaged over chromospheric network and non-network regions. We present a model which includes these factors. By constraining the model to conform to results from earlier UV and optical studies we are effectively left with two free parameters: the temperature at the core of the spicules, Tsub(c)sub(o)sub(r)sub(e), and (at solar minimum), the interspicular chromospheric network density model of the lower transition zone. The absence of limb brightening at the short millimeter wavelengths implies Tsub(c)sub(o)sub(r)sub(e) approx. < 6000 k. Differences between the model and certain deconvolved observations near 9 mm are expected as a consequence of an extension of emission beyond the optical limb, predicted by the model, which affects the accuracy of the deconvolution technique. Unlike models which assume homogeous spicules in a random distribution, ours does not require an abnormally high spicule area.

  9. Tendon vibration attenuates superficial venous vessel response of the resting limb during static arm exercise

    Directory of Open Access Journals (Sweden)

    Ooue Anna

    2012-11-01

    Full Text Available Abstract Background The superficial vein of the resting limb constricts sympathetically during exercise. Central command is the one of the neural mechanisms that controls the cardiovascular response to exercise. However, it is not clear whether central command contributes to venous vessel response during exercise. Tendon vibration during static elbow flexion causes primary muscle spindle afferents, such that a lower central command is required to achieve a given force without altering muscle force. The purpose of this study was therefore to investigate whether a reduction in central command during static exercise with tendon vibration influences the superficial venous vessel response in the resting limb. Methods Eleven subjects performed static elbow flexion at 35% of maximal voluntary contraction with (EX + VIB and without (EX vibration of the biceps brachii tendon. The heart rate, mean arterial pressure, and rating of perceived exertion (RPE in overall and exercising muscle were measured. The cross-sectional area (CSAvein and blood velocity of the basilic vein in the resting upper arm were assessed by ultrasound, and blood flow (BFvein was calculated using both variables. Results Muscle tension during exercise was similar between EX and EX + VIB. However, RPEs at EX + VIB were lower than those at EX (P P vein in the resting limb at EX decreased during exercise from baseline (P vein at EX + VIB did not change during exercise. CSAvein during exercise at EX was smaller than that at EX + VIB (P vein did not change during the protocol under either condition. The decreases in circulatory response and RPEs during EX + VIB, despite identical muscle tension, showed that activation of central command was less during EX + VIB than during EX. Abolishment of the decrease in CSAvein during exercise at EX + VIB may thus have been caused by a lower level of central command at EX + VIB rather than EX. Conclusion Diminished central command induced by tendon

  10. CALIBRATED HYDRODYNAMIC MODEL

    Directory of Open Access Journals (Sweden)

    Sezar Gülbaz

    2015-01-01

    Full Text Available The land development and increase in urbanization in a watershed affect water quantityand water quality. On one hand, urbanization provokes the adjustment of geomorphicstructure of the streams, ultimately raises peak flow rate which causes flood; on theother hand, it diminishes water quality which results in an increase in Total SuspendedSolid (TSS. Consequently, sediment accumulation in downstream of urban areas isobserved which is not preferred for longer life of dams. In order to overcome thesediment accumulation problem in dams, the amount of TSS in streams and inwatersheds should be taken under control. Low Impact Development (LID is a BestManagement Practice (BMP which may be used for this purpose. It is a land planningand engineering design method which is applied in managing storm water runoff inorder to reduce flooding as well as simultaneously improve water quality. LID includestechniques to predict suspended solid loads in surface runoff generated over imperviousurban surfaces. In this study, the impact of LID-BMPs on surface runoff and TSS isinvestigated by employing a calibrated hydrodynamic model for Sazlidere Watershedwhich is located in Istanbul, Turkey. For this purpose, a calibrated hydrodynamicmodel was developed by using Environmental Protection Agency Storm WaterManagement Model (EPA SWMM. For model calibration and validation, we set up arain gauge and a flow meter into the field and obtain rainfall and flow rate data. Andthen, we select several LID types such as retention basins, vegetative swales andpermeable pavement and we obtain their influence on peak flow rate and pollutantbuildup and washoff for TSS. Consequently, we observe the possible effects ofLID on surface runoff and TSS in Sazlidere Watershed.

  11. Hydrodynamic escape from planetary atmospheres

    Science.gov (United States)

    Tian, Feng

    Hydrodynamic escape is an important process in the formation and evolution of planetary atmospheres. Due to the existence of a singularity point near the transonic point, it is difficult to find transonic steady state solutions by solving the time-independent hydrodynamic equations. In addition to that, most previous works assume that all energy driving the escape flow is deposited in one narrow layer. This assumption not only results in less accurate solutions to the hydrodynamic escape problem, but also makes it difficult to include other chemical and physical processes in the hydrodynamic escape models. In this work, a numerical model describing the transonic hydrodynamic escape from planetary atmospheres is developed. A robust solution technique is used to solve the time dependent hydrodynamic equations. The method has been validated in an isothermal atmosphere where an analytical solution is available. The hydrodynamic model is applied to 3 cases: hydrogen escape from small orbit extrasolar planets, hydrogen escape from a hydrogen rich early Earth's atmosphere, and nitrogen/methane escape from Pluto's atmosphere. Results of simulations on extrasolar planets are in good agreement with the observations of the transiting extrasolar planet HD209458b. Hydrodynamic escape of hydrogen from other hypothetical close-in extrasolar planets are simulated and the influence of hydrogen escape on the long-term evolution of these extrasolar planets are discussed. Simulations on early Earth suggest that hydrodynamic escape of hydrogen from a hydrogen rich early Earth's atmosphere is about two orders magnitude slower than the diffusion limited escape rate. A hydrogen rich early Earth's atmosphere could have been maintained by the balance between the hydrogen escape and the supply of hydrogen into the atmosphere by volcanic outgassing. Origin of life may have occurred in the organic soup ocean created by the efficient formation of prebiotic molecules in the hydrogen rich early

  12. Lower limb edema after arterial reconstruction, a comparison with lymph, reconstruction and DVT edema by RI scintigram

    International Nuclear Information System (INIS)

    Ojiro, M.; Takenosita, M.; Toshinaga, R.; Shimazu, H.; Nakajo, M.; Iwasita, S.

    1991-01-01

    Postoperative lower limb edema after arterial-reconstruction is common complication. However the precise mechanism of this process is not fully understood. In order to investigate this pathogenesis, it was studied whether the postoperative edema was affected by the various types of reconstruction, the materials, the degree of preoperative ischemia and the grade of improvement of ankle pressure index (API) after reconstruction retrospectively. Furthermore, by pertechnetate anion the difference of scintigraph pattern was studied in the lower limb and was compared with postoperative edema, lymph edema and acute deep vein thrombosis (DVT) with swelling limb. (author). 4 refs.; 2 figs

  13. Pulmonary embolism and pelvic-lower limb deep venous thrombosis: initial experience with magnetic resonance angiography

    International Nuclear Information System (INIS)

    Jiang Tao; Qiu Chuanya; Jiang Hua

    2004-01-01

    Objective: To evaluate the usefulness of combined three-dimensional (3D) and two-dimensional (2D) contrast enhanced magnetic resonance angiography (CE-MRA) for checking the thrombus embolism of different positions within single examination on the pulmonary artery and pelvic-lower limb deep veins. Methods: Fifteen patients with suspected pulmonary embolism and pelvic-lower limb deep venous thrombosis (DVT) were evaluate with combined 3D MRA and 2D CE-MRA. 3D spoiled gradient-recalled-echo bolus chase MR angiograms were obtained in four stations from the pulmonary artery to the ankle. Thereafter, 3D CE MRA was reversely scanned from the ankle to the pelvic. 2D contrast-enhanced MRI was obtained in pelvis, thigh, and calf. Pulmonary CT angiography (CTA) and/or DSA were performed in 15 patients, and duplex ultrasonography of lower-limb vein was performed in 12 patients. Results: Of the 15 cases, acceptable imaging of pulmonary vessel was acquired with 3D CE-MRA in 12 cases. The signal intensity was lower in the deep iliac vein and lower extremities than that in the artery, but vein frame was distinct after post processing. The artery and deep vein were clearly revealed with contrast enhanced FSPGR sequence in 15 cases. 3D CD-MRA imaging disclosed pulmonary embolism in fourteen patients and pelvis-lower limb DVT with multi-place involvement in nine patients. 2D contrast-enhanced MR imaging proved DVT in pelvis-lower limb. 2D contrast-enhanced FSPGR sequence was a complementation of 3D CE-MRA and it had larger scan field. Thrombus presented as low signals and eccentral or intraluminal filling defect. Local caliber of vein thrombus in 6 cases was evidently broadened. Conclusion: Within only one MR examination procedure, it is capable of examining the pulmonary embolism and DVT of pelvis-lower limb with combined 3D MRA and 2D contrast enhanced MR. The results are promising as a non-invasion 'on-stop shopping' tool in the evaluation of thromboembolic disease

  14. The umbilical and paraumbilical veins of man.

    Science.gov (United States)

    Martin, B F; Tudor, R G

    1980-03-01

    During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persists in an eccentric position. This residual lumen transmits blood to the portal system from paraumbilical and systemic sources, and is retained in the upper part of the vein, even in old age. A similar process of lumen closure is observed in the ductus venosus. In early childhood the lower third of the vein undergoes breakdown, with fatty infiltration, resulting in its complete division into vascular fibro-elastic strands, and in old age some breakdown occurs in the outermost part of the wall of the upper two thirds. The paraumbilical veins are thick-walled and of similar structure to the umbilical vein. Together they constitute an accessory portal system which is confined between the layers of the falciform ligament and is in communication with the veins of the ventral abdominal wall. The constituents form an ascending series, namely, Burow's veins, the umbilical vein, and Sappey's inferior and superior veins. The main channel of Sappey's inferior veins may be the remnant of the right umbilical vein since it communicates with the right rectus sheath and often communicates directly with the portal system within the right lobe of the liver. The results are of significance in relation to clinical usage of the umbilical vein.

  15. Distal anastomotic vein adjunct usage in infrainguinal prosthetic bypasses.

    Science.gov (United States)

    McPhee, James T; Goodney, Philip P; Schanzer, Andres; Shaykevich, Shimon; Belkin, Michael; Menard, Matthew T

    2013-04-01

    Single-segment saphenous vein remains the optimal conduit for infrainguinal revascularization. In its absence, prosthetic conduit may be used. Existing data regarding the significance of anastomotic distal vein adjunct (DVA) usage with prosthetic grafts are based on small series. This is a retrospective cohort analysis derived from the regional Vascular Study Group of New England as well as the Brigham and Women's hospital database. A total of 1018 infrainguinal prosthetic bypass grafts were captured in the dataset from 73 surgeons at 15 participating institutions. Propensity scoring and 3:1 matching was performed to create similar exposure groups for analysis. Outcome measures of interest included: primary patency, freedom from major adverse limb events (MALEs), and amputation free survival at 1 year as a function of vein patch utilization. Time to event data were compared with the log-rank test; multivariable Cox proportional hazard models were used to evaluate the adjusted association between vein cuff usage and the primary end points. DVA was defined as a vein patch, cuff, or boot in any configuration. Of the 1018 bypass operations, 94 (9.2%) had a DVA whereas 924 (90.8%) did not (no DVA). After propensity score matching, 88 DVAs (25%) and 264 no DVAs (75%) were analyzed. On univariate analysis of the matched cohort, the DVA and no DVA groups were similar in terms of mean age (70.0 vs 69.0; P = .55), male sex (58.0% vs 58.3%; P > .99), and preoperative characteristics such as living at home (93.2% vs 94.3%; P = .79) and independent ambulatory status (72.7% vs 75.7%; P = .64). The DVA and no DVA groups had similar rates of major comorbidities such as hypertension chronic obstructive pulmonary disease, diabetes mellitus, coronary artery disease, and dialysis dependence (P > .05 for all). Likewise, they had similar rates of distal origin grafts (13.6% vs 12.5%; P = .85), critical limb ischemia indications (P = .53), and prior arterial bypass (58% vs 47%; P = .08

  16. Limb immobilization and corticobasal syndrome.

    Science.gov (United States)

    Graff-Radford, Jonathan; Boeve, Bradley F; Drubach, Daniel A; Knopman, David S; Ahlskog, J Eric; Golden, Erin C; Drubach, Dina I; Petersen, Ronald C; Josephs, Keith A

    2012-12-01

    Recently, we evaluated two patients with corticobasal syndrome (CBS) who reported symptom onset after limb immobilization. Our objective was to investigate the association between trauma, immobilization and CBS. The charts of forty-four consecutive CBS patients seen in the Mayo Clinic Alzheimer Disease Research Center were reviewed with attention to trauma and limb immobilization. 10 CBS patients (23%) had immobilization or trauma on the most affected limb preceding the onset or acceleration of symptoms. The median age at onset was 61. Six patients manifested their first symptoms after immobilization from surgery or fracture with one after leg trauma. Four patients had pre-existing symptoms of limb dysfunction but significantly worsened after immobilization or surgery. 23 percent of patients had immobilization or trauma of the affected limb. This might have implications for management of CBS, for avoiding injury, limiting immobilization and increasing movement in the affected limb. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Normal hepatic vein patterns on ultrasound

    International Nuclear Information System (INIS)

    Kim, Hae Jin; Chae, Yoo Soon; Park, Hea Yeoung; Park, Bok Hwan; Kim, Yang Sook

    1987-01-01

    Understanding of the anatomy of the hepatic vein is important in manipulation for transplantation of the liver, hepatectomy and the treatment of hepatic trauma with avulsion of the hepatic vein. Demonstrated of the inferior right hepatic vein (IRHV) is also important; in some cases of hepatocellular carcinoma, thrombus can be seen in the IRHV; in primary Budd-Chiari syndrome, the IRHV is main draining vein; during hepatectomy, the postero-inferior segment of the right lobe and draining IRHV can be preserved. For some 10 months ultrasound examination was done in a total of 124 patients with normal liver function with special emphasis on the hepatic vein, their branches, and the IRHV, and analysed in terms of branching pattern and relative size of the hepatic vein and the detection rate of the IRHV.

  18. Limb lengthening in achondroplasia

    Directory of Open Access Journals (Sweden)

    Sanjay K Chilbule

    2016-01-01

    Full Text Available Background: Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Materials and Methods: Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Results: Nine patients aged five to 25 years (mean age 10.2 years underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%, 9.9 cm (52.8% and 9.6 cm (77.9%, respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3 rd percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment. Healing index was not affected by age or bone segment. Conclusion: Extensive limb lengthening (more than 50% over initial length carries significant risk and should be undertaken only after due

  19. Limb lengthening in achondroplasia.

    Science.gov (United States)

    Chilbule, Sanjay K; Dutt, Vivek; Madhuri, Vrisha

    2016-01-01

    Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Nine patients aged five to 25 years (mean age 10.2 years) underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%), 9.9 cm (52.8%) and 9.6 cm (77.9%), respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3(rd) percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment). Healing index was not affected by age or bone segment. Extensive limb lengthening (more than 50% over initial length) carries significant risk and should be undertaken only after due consideration.

  20. Safety and efficacy of stenting nonthrombotic iliac vein lesions in octogenarians and nonagenarians in an office setting.

    Science.gov (United States)

    Kibrik, Pavel; Eisenberg, Justin; Alsheekh, Ahmad; Rizvi, Syed Ali; Aurshina, Afsha; Marks, Natalie; Hingorani, Anil; Ascher, Enrico

    2018-02-01

    Objectives Treatment options for venous insufficiency are rapidly evolving in the office setting and include venography, intravascular ultrasound, and venous stenting. Non-thrombotic iliac vein lesions assessment and treatment in an office setting is currently an area of interest. The purpose of this study is to demonstrate the safety and efficacy of evaluating non-thrombotic iliac vein lesion with this office-based procedure in octogenarians and nonagenarians. Methods From January 2012 through December 2013, 300 non-thrombotic iliac vein lesion limbs in 192 patients with venous insufficiency ≥80 years old were evaluated for non-thrombotic iliac vein lesion. Patients were evaluated and treated with venography, intravascular ultrasound, and stent placement for significant lesions demonstrated by greater than 50% diameter or cross-sectional area reduction. Group 1: 168 of these patients were octogenarians; female/male ratio was 1.75:1, bilateral in 89/168 patients (53%), left sided in 131/259 limbs (51%), right sided in 128 limbs (49%), average age 83.5 ± 2.6 years (range 80-89) compared to Group 2: 24 nonagenarians; female/male was 3:1, bilateral in 17/24 patients (70%), left sided in 20/41 limbs (49%), right sided in 21/41 limbs (51%), average age 92.9 ± 2.2 years (range 90-99). Stent related outcomes were evaluated with communication to the patient within 24 h to assess post-procedure pain followed by serial iliocaval ultrasonography. Results Out of the 300 limbs evaluated, in Group 1, 86% of limbs had stents placed compared to 90% in Group 2 and 11% of both groups had two stents placed. Overall improvement in pain, edema, and ulcers was reported in 147 (59%) of octogenarians and 24 (65%) of nonagenarians. There were no surgical site infections, pseudo-aneurysms, arteriovenous fistulas, or femoral artery injuries. No patients required transfusion within three days post-operatively and there were no 30-day mortalities in both sets of patients

  1. Generating and analyzing synthetic finger vein images

    OpenAIRE

    Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

    2014-01-01

    Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have posed challenges in exploring this technology for large scale applications. This paper details the first such attempt to synthesize finger-vein images and presents analysis of synthesized images fo...

  2. Preduodenal portal vein: its surgical significance.

    Science.gov (United States)

    Makey, D A; Bowen, J C

    1978-11-01

    Preduodenal portal vein is a rare anatomical variant which may be one of many anomalies in the neonate with duodenal "atresia." Preduodenal portal vein also may be an occasional finding in an adult undergoing biliary, gastric, or pancreatic surgery. Awareness and recognition of the anomaly are essential for the avoidance of injury during such operations. We report here a symptomless patient whose preduodenal portal vein was discovered at cholecystectomy.

  3. Soliton Gases and Generalized Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Yoshimura, Takato; Caux, Jean-Sébastien

    2018-01-01

    We show that the equations of generalized hydrodynamics (GHD), a hydrodynamic theory for integrable quantum systems at the Euler scale, emerge in full generality in a family of classical gases, which generalize the gas of hard rods. In this family, the particles, upon colliding, jump forward or backward by a distance that depends on their velocities, reminiscent of classical soliton scattering. This provides a "molecular dynamics" for GHD: a numerical solver which is efficient, flexible, and which applies to the presence of external force fields. GHD also describes the hydrodynamics of classical soliton gases. We identify the GHD of any quantum model with that of the gas of its solitonlike wave packets, thus providing a remarkable quantum-classical equivalence. The theory is directly applicable, for instance, to integrable quantum chains and to the Lieb-Liniger model realized in cold-atom experiments.

  4. Anomalous hydrodynamics of Weyl materials

    Science.gov (United States)

    Monteiro, Gustavo; Abanov, Alexander

    Kinetic theory is a useful tool to study transport in Weyl materials when the band-touching points are hidden inside a Fermi surface. It accounts, for example, for the negative magnetoresistance caused by the chiral magnetic effect and quantum oscillations (SdH effect) in the magnetoresistance together within the same framework. As an alternative approach to kinetic theory we also consider the regime of strong interactions where hydrodynamics can be applicable. A variational principle of these hydrodynamic equations can be found in and provide a natural framework to study hydrodynamic surface modes which correspond to the strongly-interacting physics signature of Fermi arcs. G.M. acknowledges the financial support from FAPESP.

  5. Brownian dynamics with hydrodynamic interactions

    International Nuclear Information System (INIS)

    Ermak, D.L.; McCammon, J.A.

    1978-01-01

    A method for simulating the Brownian dynamics of N particles with the inclusion of hydrodynamic interactions is described. The particles may also be subject to the usual interparticle or external forces (e.g., electrostatic) which have been included in previous methods for simulating Brownian dynamics of particles in the absence of hydrodynamic interactions. The present method is derived from the Langevin equations for the N particle assembly, and the results are shown to be consistent with the corresponding Fokker--Planck results. Sample calculations on small systems illustrate the importance of including hydrodynamic interactions in Brownian dynamics simulations. The method should be useful for simulation studies of diffusion limited reactions, polymer dynamics, protein folding, particle coagulation, and other phenomena in solution

  6. The influence of upper limb position on the effect of a contrast agent in chest CT enhancement

    International Nuclear Information System (INIS)

    Feng, Shi-Ting; Wang, Meng; Gao, Zhenhua; Tan, Guosheng; Cai, Huasong; Hu, Xiaoshu; Yang, Jianyong; Li, Zi-Ping

    2013-01-01

    Purpose: To compare the influence of two different upper limb positions on contrast agent effects in chest CT enhancement. Materials and methods: In 142 patients undergoing contrast-enhanced CT chest scanning, an indwelling venous catheter was placed in the right hand and iodinated contrast agent was injected through a high-pressure single syringe pump. The patients were divided into three age groups (<40 years; 40–60 years; and >60 years) and randomly assigned to one of two upper limb position groups: (1) supine position, both upper limbs extended and raised above head in the same horizontal plane as the body; and (2) supine position, both upper limbs raised and crossed on the forehead, with the right arm on top. Differences in mean CT values on the two sides of the thoracic inlet along the right subclavian vein were used to evaluate the effects of the contrast agent. Results: Although contrast agent effects were not significantly different among the three age groups with either limb position, there was a significant difference between patients adopting the second limb positions (Chi-square value was 5.936, P < 0.05). An excellent or good contrast agent effect was observed in 63.08% of patients assuming the first limb position, as compared with 81.69% assuming the second position. Conclusion: For contrast-enhanced CT chest scans, use of the second limb position can reduce retention of the contrast agent in the right axillary vein and the right subclavian vein outside the thorax, increase contrast agent utilization, and decrease artifacts caused by high-density, local retention of the contrast agent

  7. Abnormal pressures as hydrodynamic phenomena

    Science.gov (United States)

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  8. Anisotropic hydrodynamics: Motivation and methodology

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael

    2014-06-15

    In this proceedings contribution I review recent progress in our understanding of the bulk dynamics of relativistic systems that possess potentially large local rest frame momentum-space anisotropies. In order to deal with these momentum-space anisotropies, a reorganization of relativistic viscous hydrodynamics can be made around an anisotropic background, and the resulting dynamical framework has been dubbed “anisotropic hydrodynamics”. I also discuss expectations for the degree of momentum-space anisotropy of the quark–gluon plasma generated in relativistic heavy ion collisions at RHIC and LHC from second-order viscous hydrodynamics, strong-coupling approaches, and weak-coupling approaches.

  9. Hydrodynamics of oceans and atmospheres

    CERN Document Server

    Eckart, Carl

    1960-01-01

    Hydrodynamics of Oceans and Atmospheres is a systematic account of the hydrodynamics of oceans and atmospheres. Topics covered range from the thermodynamic functions of an ideal gas and the thermodynamic coefficients for water to steady motions, the isothermal atmosphere, the thermocline, and the thermosphere. Perturbation equations, field equations, residual equations, and a general theory of rays are also presented. This book is comprised of 17 chapters and begins with an introduction to the basic equations and their solutions, with the aim of illustrating the laws of dynamics. The nonlinear

  10. Hydrodynamic constants from cosmic censorship

    International Nuclear Information System (INIS)

    Nakamura, Shin

    2008-01-01

    We study a gravity dual of Bjorken flow of N=4 SYM-theory plasma. We point out that the cosmic censorship hypothesis may explain why the regularity of the dual geometry constrains the hydrodynamic constants. We also investigate the apparent horizon of the dual geometry. We find that the dual geometry constructed on Fefferman-Graham (FG) coordinates is not appropriate for examination of the apparent horizon since the coordinates do not cover the trapped region. However, the preliminary analysis on FG coordinates suggests that the location of the apparent horizon is very sensitive to the hydrodynamic parameters. (author)

  11. Hydrodynamic simulation of elliptic flow

    CERN Document Server

    Kolb, P F; Ruuskanen, P V; Heinz, Ulrich W

    1999-01-01

    We use a hydrodynamic model to study the space-time evolution transverse to the beam direction in ultrarelativistic heavy-ion collisions with nonzero impact parameters. We focus on the influence of early pressure on the development of radial and elliptic flow. We show that at high energies elliptic flow is generated only during the initial stages of the expansion while radial flow continues to grow until freeze-out. Quantitative comparisons with SPS data from semiperipheral Pb+Pb collisions suggest the applicability of hydrodynamical concepts already $\\approx$ 1 fm/c after impact.

  12. Doppler ultrasound venous mapping of the lower limbs

    Directory of Open Access Journals (Sweden)

    Galeandro AI

    2012-02-01

    Full Text Available Aldo Innocente Galeandro1, Giovanni Quistelli2, Pietro Scicchitano2, Michele Gesualdo2, Annapaola Zito2, Paola Caputo2, Rosa Carbonara2, Giuseppe Galgano3, Francesco Ciciarello4, Sandro Mandolesi4, Claude Franceschi5, Marco Matteo Ciccone21Centro Diagnostica Globale and ASL-TA, Taranto, Italy; 2Cardiovascular Diseases Section, Department of Emergency and Organ Transplantation (DETO, University of Bari, Bari, Italy; 3Cardiovascular Diseases Section, Ente Ecclesiastico Ospedale Generale Regionale F Miulli, Acquaviva delle Fonti, Bari, Italy; 4Cardiology Department, Policlinico Umberto I, Sapienza University of Rome, Italy; 5Vascular Laboratories of Hospitals Saint Joseph and Pitié-Salpétrière, Paris, FranceBackground: The study aim was to test the accuracy (intra and interobserver variability, sensitivity, and specificity of a simplified noninvasive ultrasound methodology for mapping superficial and deep veins of the lower limbs.Methods: 62 consecutive patients, aged 62 ± 11 years, were enrolled. All underwent US-examinations, performed by two different investigators, of both legs, four anatomical parts, and 17 veins, to assess the interobserver variability of evaluation of superficial and deep veins of the lower limbs.Results: Overall the agreement between the second versus the first operator was very high in detecting reflux (sensitivity 97.9, specificity 99.7, accuracy 99.5; P = 0.80 at McNemar test. The higher CEAP classification stages were significantly associated with reflux (odds ratio: 1.778, 95% confidence interval: 1.552–2.038; P < 0.001 as well as with thrombosis (odds ratio: 2.765, 95% confidence interval: 1.741–4.389; P < 0.001. Thus, our findings show a strict association between the symptoms of venous disorders and ultrasound evaluation results for thrombosis or reflux.Conclusion: This study demonstrated that our venous mapping protocol is a reliable method showing a very low interobserver variability, which makes it

  13. Arterial mapping of lower limbs

    International Nuclear Information System (INIS)

    Acuna Allen, Rafael

    2011-01-01

    A bibliographic review is realized in the arterial mapping of lower limbs by ultrasonographic. The physical properties of the Doppler effect applied to diagnostic ultrasound are described. The anatomical characteristics of the general arterial system and specifically of the lower limbs arterial system are mentioned. Pathologies of the ischemic arterial disease of lower limbs are explained. The study characteristics of lower limbs arterial mapping are documented to determine its importance as appropriate method for the assessment of lower limb ischemia. An adequate arterial mapping of lower limbs is recognized in atherosclerotic ischemic disease as a reliable initial method alternative to arteriography. Arteriography is considered as reference pattern for therapeutic decision making in patients with critical ischemia of the lower limbs. Non-invasive methods to assess the arterial system of lower limbs has evidenced the advantages of the arterial mapping with Doppler, according to the consulted literature. The combination morphological and hemodynamic information has been possible and a map of the explored zone is made. The arterial mapping by ultrasonography has offered similar reliability to angiography [es

  14. Normal distal pulmonary vein anatomy

    Directory of Open Access Journals (Sweden)

    Wiesława Klimek-Piotrowska

    2016-01-01

    Full Text Available Background. It is well known that the pulmonary veins (PVs, especially their myocardial sleeves play a critical role in the initiation and maintenance of atrial fibrillation. Understanding the PV anatomy is crucial for the safety and efficacy of all procedures performed on PVs. The aim of this study was to present normal distal PV anatomy and to create a juxtaposition of all PV ostium variants.Methods. A total of 130 randomly selected autopsied adult human hearts (Caucasian were examined. The number of PVs ostia was evaluated and their diameter was measured. The ostium-to-last-tributary distance and macroscopic presence of myocardial sleeves were also evaluated.Results. Five hundred forty-one PV ostia were identified. Four classical PV ostia patterns (two left and two right PVs were observed in 70.8% of all cases. The most common variant was the classical pattern with additional middle right PV (19.2%, followed by the common ostium for the left superior and the inferior PVs (4.44%. Mean diameters of PV ostia (for the classical pattern were: left superior = 13.8 ± 2.9 mm; left inferior = 13.3 ± 3.4 mm; right superior = 14.3 ± 2.9 mm; right inferior = 13.7 ± 3.3 mm. When present, the additional middle right PV ostium had the smallest PV ostium diameter in the heart (8.2 ± 4.1 mm. The mean ostium-to-last-tributary (closest to the atrium distances were: left superior = 15.1 ± 4.6 mm; left inferior = 13.5 ± 4.0 mm; right superior = 11.8 ± 4.0 mm; right inferior = 11.0 ± 3.7 mm. There were no statistically significant differences between sexes in ostia diameters and ostium-to-last-tributary distances.Conclusion. Only 71% of the cases have four standard pulmonary veins. The middle right pulmonary vein is present in almost 20% of patients. Presented data can provide useful information for the clinicians during interventional procedures or radiologic examinations of PVs.

  15. Anomalous hydrodynamics in two dimensions

    Indian Academy of Sciences (India)

    Abstract. A new approach is presented to discuss two-dimensional hydrodynamics with gauge and gravitational anomalies. Exact constitutive relations for the stress tensor and charge current are obtained. Also, a connection between response parameters and anomaly coefficients is discussed. These are new results which, ...

  16. Topics in fluctuating nonlinear hydrodynamics

    International Nuclear Information System (INIS)

    Milner, S.T.

    1986-01-01

    Models of fluctuating nonlinear hydrodynamics have enjoyed much success in explaining the effect of long-wavelength fluctuations in diverse hydrodynamic systems. This thesis explores two such problems; in both, the body of hydrodynamic assumptions powerfully constrains the predictions of a well-posed theory. The effects of layer fluctuations in smectic-A liquid crystals are first examined. The static theory (introduced by Grinstein and Pelcovits) is reviewed. Ward identities, resulting from the arbitrariness of the layering direction, are derived and exploited. The static results motivate an examination of dynamic fluctuation effects. A new sound-damping experiment is proposed that would probe singular dependence of viscosities on applied stress. A theory of Procaccia and Gitterman that reaction rates of chemically reacting binary mixtures are drastically reduced near their thermodynamic critical points is analyzed. Hydrodynamic arguments and Van Hove theory are applied, concluding that the PG idea is drastically slowed, and spatially varying composition fluctuations are at best slowed down over a narrow range of wavenumbers

  17. Radiation hydrodynamics in the laboratory

    International Nuclear Information System (INIS)

    1985-12-01

    This report contains a collection of five preprints devoted to the subject of laser induced phenomena of radiation hydrodynamics. These preprints cover approximately the contents of the presentations made by the MPQ experimental laser-plasma group at the 17th European Conference on Laser Interaction with Matter (ECLIM), Rome, November 18-22, 1985. (orig.)

  18. Numerical Hydrodynamics in General Relativity

    Directory of Open Access Journals (Sweden)

    Font José A.

    2003-01-01

    Full Text Available The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article, the present update provides additional information on numerical schemes, and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes, and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.

  19. Hydrodynamics of a quark droplet

    DEFF Research Database (Denmark)

    Bjerrum-Bohr, Johan J.; Mishustin, Igor N.; Døssing, Thomas

    2012-01-01

    We present a simple model of a multi-quark droplet evolution based on the hydrodynamical description. This model includes collective expansion of the droplet, effects of the vacuum pressure and surface tension. The hadron emission from the droplet is described following Weisskopf's statistical...

  20. Hydrodynamic instabilities in inertial fusion

    International Nuclear Information System (INIS)

    Hoffman, N.M.

    1994-01-01

    This report discusses topics on hydrodynamics instabilities in inertial confinement: linear analysis of Rayleigh-Taylor instability; ablation-surface instability; bubble rise in late-stage Rayleigh-Taylor instability; and saturation and multimode interactions in intermediate-stage Rayleigh-Taylor instability

  1. Evaluation of Limb-Girdle Muscular Dystrophy

    Science.gov (United States)

    2014-03-06

    Becker Muscular Dystrophy; Limb-Girdle Muscular Dystrophy, Type 2A (Calpain-3 Deficiency); Limb-Girdle Muscular Dystrophy, Type 2B (Miyoshi Myopathy, Dysferlin Deficiency); Limb-Girdle Muscular Dystrophy, Type 2I (FKRP-deficiency)

  2. Retinal vein occlusion: pathophysiology and treatment options

    OpenAIRE

    Karia, Niral

    2010-01-01

    Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss

  3. Generating and analyzing synthetic finger vein images

    NARCIS (Netherlands)

    Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

    2014-01-01

    Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have

  4. Preoperative mapping of the saphenous vein

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Sillesen, H; Nielsen, Tina G

    1996-01-01

    A series of 124 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. 33 (27%) bypass procedures thrombosed within the first year. A naturally occurring optimal vein diameter was discovered: 5.0-6.5 mm at mid-thigh lev...

  5. IVC filter limb penetration of the caval wall during retroperitoneal surgery/lymph node dissection.

    LENUS (Irish Health Repository)

    Goh, Gerard S

    2012-12-01

    Optional inferior vena cava (IVC) filters are being increasingly used for protection against pulmonary embolism in patients with deep vein thrombosis where anticoagulation is contraindicated. We describe two cases during retroperitoneal surgery where the IVC filters were found to have perforated the cava wall and were subsequently removed intra-operatively. Cava wall penetration by filter limbs poses a significant danger during retroperitoneal lymph node dissection and filters should be removed preoperatively.

  6. Venous ulcers of the lower limb: Where do we stand?

    Directory of Open Access Journals (Sweden)

    Chatterjee S Sasanka

    2012-01-01

    Full Text Available Venous ulcers are the most common ulcers of the lower limb. It has a high morbidity and results in economic strain both at a personal and at a state level. Chronic venous hypertension either due to primary or secondary venous disease with perforator paucity, destruction or incompetence resulting in reflux is the underlying pathology, but inflammatory reactions mediated through leucocytes, platelet adhesion, formation of pericapillary fibrin cuff, growth factors and macromolecules trapped in tissue result in tissue hypoxia, cell death and ulceration. Duplex scan with colour flow is the most useful investigation for venous disease supplying information about patency, reflux, effects of proximal and distal compression, Valsalva maneuver and effects of muscle contraction. Most venous disease can be managed conservatively by leg elevation and compression bandaging. Drugs of proven benefit in venous disease are pentoxifylline and aspirin, but they work best in conjunction with compression therapy. Once ulceration is chronic or the patient does not respond to or cannot maintain conservative regime, surgical intervention treating the underlying venous hypertension and cover for the ulcer is necessary. The different modalities like sclerotherapy, ligation and stripping of superficial varicose veins, endoscopic subfascial perforator ligation, endovenous laser or radiofrequency ablation have similar long-term results, although short-term recovery is best with radiofrequency and foam sclerotherapy. For deep venous reflux, surgical modalities include repair of incompetent venous valves or transplant or transposition of a competent vein segment with normal valves to replace a post-thrombotic destroyed portion of the deep vein.

  7. Limb girdle muscular dystrophies

    DEFF Research Database (Denmark)

    Vissing, John

    2016-01-01

    PURPOSE OF REVIEW: The aim of the study was to describe the clinical spectrum of limb girdle muscular dystrophies (LGMDs), the pitfalls of the current classification system for LGMDs, and emerging therapies for these conditions. RECENT FINDINGS: Close to half of all LGMD subtypes have been...... or are registered in other classification systems for muscle disease. On the contrary, diseases that fulfill classical criteria for LGMD have found no place in the LGMD classification system. These shortcomings call for revision/creation of a new classification system for LGMD. The rapidly expanding gene sequencing...... capabilities have helped to speed up new LGMD discoveries, and unveiled pheno-/genotype relations. Parallel to this progress in identifying new LGMD subtypes, emerging therapies for LGMDs are under way, but no disease-specific treatment is yet available for nonexperimental use. SUMMARY: The field of LGMD...

  8. The veining phenomenon in unalloyed plutonium

    International Nuclear Information System (INIS)

    White, J.S.

    1976-01-01

    An investigation has been made of the veining phenomenon in unalloyed plutonium. The surface markings, or veins, which are sometimes seen on α-phase plutonium samples, arise as a result of the β→α transformation. As far as is known, this veining is unrivalled in its scale and form as compared with the solid state surface transformation effects shown by any other metal. The phenomenon has been explained by the application of the Le Chatelier principle to the phase change. In this instance, the large (10%) volume contraction associated with the β→α reaction and the anisotropy of the nonoclinic α-phase structure, account for the fact that the veins are so prominent in plutonium. On the basis of the proposed model, the veins can only form at temperatures where the transformation mechanism is non-martensitic. (Auth.)

  9. Ultrasound assessment of great saphenous vein insufficiency

    Directory of Open Access Journals (Sweden)

    Chander RK

    2015-06-01

    Full Text Available Rajiv K Chander,1 Thomas S Monahan1,2 1Section of Vascular Surgery, Department of Surgery, University of Maryland School of Medicine, 2Department of Surgery, Baltimore Veterans Affairs Medical Center, Baltimore, MD, USA Abstract: Duplex ultrasonography is the ideal modality to assess great saphenous vein insufficiency. Duplex ultrasonography incorporates both gray scale images to delineate anatomy and color-Doppler imaging that visualizes the flow of blood in a structure. Assessment of great saphenous vein requires definition of the anatomy, augmentation of flow, evaluation for both superficial and deep vein thrombosis, and determining the presence of reflux. Currently, evolution in the treatment of reflux also relies on ultrasound for the treatment of the disease. Understanding the utilization of the ultrasound for the diagnosis and treatment of greater saphenous vein reflux is important for practitioners treating reflux disease. Keywords: duplex ultrasonography, small saphenous vein 

  10. Cavernous transformation of the portal vein

    International Nuclear Information System (INIS)

    Lehotska, V.; Dostalova, K.; Durkovsky, A.; Samal, V.

    1995-01-01

    In this contribution, the authors give an account of a rare case of a cavernous transformation of the portal vein that may have originated secondarily in a proliferative hematogenous disease with a polyglobulia and thrombosis in the periferal blood count as well as development of portal hypertension of a prehepatal type. The state of hyper-coagulation in a myeloproliferative disease may have lead to a chronic thrombosis of the portal vein with a subsequent malformation of the portal vein in terms of a cavernous transformation of the portal vein. The case is an interesting one because of the discrepancy between the gravity of the thrombotic complication and slightness of the symptoms in the clinical picture. The authors point out the importance of ultrasonography and computed tomography examination following the intravenous application of a water solution of a contrast medium in a morphologic diagnosing of a rare complication of a chronic thrombotic clot of the portal vein - the cavernous transformation. (authors)

  11. Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

    International Nuclear Information System (INIS)

    R Paul Drake

    2004-01-01

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

  12. Assessment and management of patients with varicose veins.

    Science.gov (United States)

    Allen, Louise

    Varicose veins are enlarged superficial veins found in the legs. This article explores the anatomy and physiology of the venous system to assist nurses to assess, manage and treat patients with varicose veins.

  13. Idiopathic Bilateral External Jugular Vein Thrombosis.

    Science.gov (United States)

    Hindi, Zakaria; Fadhel, Ehab

    2015-08-20

    Vein thrombosis is mainly determined by 3 factors, which constitute a triad called Virchow's triad: hypercoagulability, stasis, and endothelial injury. Venous thrombosis commonly occurs in the lower extremities since most of the blood resides there and flows against gravity. The veins of the lower extremities are dependent on intact valves and fully functional leg muscles. However, in case of valvular incompetency or muscular weakness, thrombosis and blood stasis will occur as a result. In contrast, the veins of the neck, specially the jugulars, have distensible walls which allow flexibility during respiration. In addition, the blood directly flows downward towards the heart. Nevertheless, many case reports mentioned the thrombosis of internal jugular veins and external jugular veins with identified risk factors. Jugular vein thrombosis has previously been associated in the literature with a variety of medical conditions, including malignancy. This report is of a case of idiopathic bilateral external jugular vein thrombosis in a 21 year-old male construction worker of Southeast Asian origin with no previous medical history who presented with bilateral facial puffiness of gradual onset over 1 month. Doppler ultrasound and computed tomography were used in the diagnosis. Further work-up showed no evidence of infection or neoplasia. The patient was eventually discharged on warfarin. The patient was assessed after 6 months and his symptoms had resolved completely. Bilateral idiopathic external jugular veins thrombosis is extremely rare and can be an indicator of early malignancy or hidden infection. While previous reports in the literature have associated jugular vein thrombosis with malignancy, the present case shows that external jugular vein thrombosis can also be found in persons without malignancy.

  14. Understanding the three-dimensional anatomy of the superficial lymphatics of the limbs.

    Science.gov (United States)

    Tourani, Saam S; Taylor, G Ian; Ashton, Mark W

    2014-11-01

    There are minimal data in the current literature regarding the depth of the superficial lymphatic collectors of the limbs in relation to the various subcutaneous tissue layers. Injection, microdissection, radiographic, and histologic studies of the superficial lymphatics and the subcutaneous tissues of 32 limbs from 15 human cadavers were performed. Five layers were consistently identified in the integument of all the upper and lower limb specimens: (1) skin, (2) subcutaneous fat, (3) superficial fascia, (4) loose areolar tissue, and (5) deep fascia. Layer 2 was further divided into superficial (2a) and deep (2c) compartments by a thin, transparent, horizontal septum (layer 2b). The main superficial veins and the superficial nerves coursed in layer 4. The lymphatic collectors were found at layer 2c and layer 4. The use of consistent nomenclature to describe the subcutaneous tissue layers facilitates a greater understanding and discussion of the anatomy. In lymphovenous anastomosis for the treatment of lymphedema, indocyanine green lymphography is an unreliable method for identification of the superficial collectors of the thigh. The medial proximal leg, the dorsum of the wrist over the anatomical snuffbox, and the volar proximal forearm provide suitable areas for locating superficial collectors with nearby matching size veins. In vertical medial thigh lift, choosing a dissection plane superficial to the great saphenous vein is unlikely to preserve the collectors of the ventromedial bundle.

  15. Distal vein patch as a form of autologus modification for infragenicular prosthetic bypass.

    Science.gov (United States)

    Totic, Dragan; Rustempasic, Nedzad; Djedovic, Muhamed; Solakovic, Sid; Vukas, Haris; Aslani, Ilijas; Krvavac, Alma; Rudalija, Dzejra; Ahmetasevic, Alen

    2013-01-01

    Preferred graft for infragenicular bypass is autologus vein. The problem is when there is not available autologus vein. Literature suggest that in these situations, prosthetic graft with some form of modification of distal anastomosis with autogenic tissue is valuable adjunctive. Frequently used modifications are Miller's cuff, Taylor's patch and St. Mary's boot. Recently, there are reports on "Distal vein patch" as a form of autologus modification which, due to its simplicity and patency rate, attracted attention. The aim of this study was to evaluate benefits of this novel modification by comparing its patencies with other autologus modification of distal anastomosis. Study was performed on 60 patients, diabetics, with critical limb ischemia (CLI). Patients were divided in two groups: Group with distal vein patch modification; and group with some other form modification - control group. Patients were followed at least 22 months. We examined patency of grafts by physical examination or using Color Doppler. For statistical purposes we used KIaplan Meier analysis and curve. Significance was determined by Mann-Whitney, Fisher's exact, Pearsons chi square or Student T test as appropriate. P value less than 0,05 was considered significant. Groups were fairly matched relative to demographics, risk factors, operative intervention and distal anastomosis site. There was not statistical difference in two year primary patency between distal vein patch and control group--50% vs 53% respectivly (X2 = 0,08; p = 0,773). Also, there was not statistically significant difference in extremity survival (77% vs 77%) and patient survival between groups (89% vs 93%; X2 = 2,458; p = 0,117). This study proved equivalent patencies of infragenicular prosthetic bypasses performed using distal vein patch technique as with any other modification of distal anastomosis.

  16. Radionuclide venography of lower limbs by subcutaneous injection; Comparison with venography by intravenous injection

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chung-Chieng; Jong, Shiang-Bin (Kaohsiung Medical College, Kaohsiung (Taiwan))

    1989-11-01

    We have proved that subcutaneous injection (SC) of a small dose of Tc-99m pertechnetate (1 to 2 mCi: 37 to 74 MBq) at acupuncture points (K-3 and B-60) may offer an alternative method of radionuclide venography (RNV) of the lower limbs. In this study, we compared intravenous (IV) RNV and SC-RNV in 22 consecutive cases with typical signs and symptoms suggesting venous abnormality of the lower limb(s) from March to May 1988. They are 11 male and 11 female, aged 47.7{plus minus}15.7 years. Among the 44 limbs of the 22 cases, 4 were normal, 12 (27.3%) were found to have varicose veins in the legs only, 18 (40.9%) had partial stenosis of the deep veins (14 poplito-tibial and 4 superficial femoral), and 13 (29.6%) had complete stenosis of the deep veins (4 poplito-tibial, 1 superficial femoral and 8 ilio-femoral). SC-RNV showed almost the same results as IV-RNV in 21 (47.7%), superior to IV-RNV in 22 (50%) (including 4.6% failure of IV-RNV), and inferior to IV-RNV in 1 (2.3%). We conclude that SC-RNV is definitely an alternative method of lower-limb venography. Since it is in most cases superior to IV-RNV, we suggest that it can take the place of IV-RNV in routine work. (author) 62 refs.

  17. Duplex sonography of the near-surface leg veins

    International Nuclear Information System (INIS)

    Mendoza, E.

    2007-01-01

    The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins

  18. Comparison of Efficacy Compressive Stockings with Heparin in Prevention of Deep Vein Thrombosis in Stroke Patients

    Directory of Open Access Journals (Sweden)

    Nastaran Majdi-Nasab

    2013-04-01

    Full Text Available Background: The present study is carried out to make a comparison between two pharmacological (heparin and physical (compression stockings in the prevention of deep vein thrombosis in lower limb of the patients suffered from acute stroke. Materials and Methods: In this investigation as a clinical trial, the effectiveness of the above methods on 100 patients with the stroke was compared in two groups of 50 persons. Results: Three patients in physical group and two patients in pharmacological group got deep vein thrombosis that showed no significant difference between two groups.Conclusion: In spite of no significant relationship and due to less incurrence of thrombosis in heparin group, it is more reasonable to use pharmacological methods.

  19. Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

    Science.gov (United States)

    Min, Seung-Kee; Kim, Young Hwan; Joh, Jin Hyun; Kang, Jin Mo; Park, Ui Jun; Kim, Hyung-Kee; Chang, Jeong-Hwan; Park, Sang Jun; Kim, Jang Yong; Bae, Jae Ik; Choi, Sun Young; Kim, Chang Won; Park, Sung Il; Yim, Nam Yeol; Jeon, Yong Sun; Yoon, Hyun-Ki; Park, Ki Hyuk

    2016-01-01

    Lower extremity deep vein thrombosis is a serious medical condition that can result in death or major disability due to pulmonary embolism or post-thrombotic syndrome. Appropriate diagnosis and treatment are required to improve symptoms and salvage the affected limb. Early thrombus clearance rapidly resolves symptoms related to venous obstruction, restores valve function and reduces the incidence of post-thrombotic syndrome. Recently, endovascular treatment has been established as a standard method for early thrombus removal. However, there are a variety of views regarding the indications and procedures among medical institutions and operators. Therefore, we intend to provide evidence-based guidelines for diagnosis and treatment of lower extremity deep vein thrombosis by multidisciplinary consensus. These guidelines are the result of a close collaboration between interventional radiologists and vascular surgeons. The goals of these guidelines are to improve treatment, to serve as a guide to the clinician, and consequently to contribute to public health care. PMID:27699156

  20. Endovascular treatment of external iliac vein stenosis caused by graft compression after kidney transplantation

    Directory of Open Access Journals (Sweden)

    Willamax Oliveira de Sousa

    2013-06-01

    Full Text Available A 57-year old patient presented with approximately 80% stenosis of the left external iliac vein due to compression by the renal graft after kidney transplantation. The initial clinical manifestation of this vascular complication was progressive edema of the left lower limb, starting in the foot during the immediate postoperative period and reaching the thigh. Renal function also deteriorated during the first four months after transplantation. Venous Doppler ultrasound findings were suggestive of a diagnosis of extrinsic compression by the kidney graft and so phlebography was ordered, confirming stenosis of the left external iliac vein. The patient was initially treated with balloon angioplasty, but there was still residual stenosis so a stent was inserted, eliminating the stenosis. The edema reduced over time and the patient's renal function improved. While vascular complications are rare, and potentially severe, events, success rates are good if treatment is started early.

  1. Personal authentication through dorsal hand vein patterns

    Science.gov (United States)

    Hsu, Chih-Bin; Hao, Shu-Sheng; Lee, Jen-Chun

    2011-08-01

    Biometric identification is an emerging technology that can solve security problems in our networked society. A reliable and robust personal verification approach using dorsal hand vein patterns is proposed in this paper. The characteristic of the approach needs less computational and memory requirements and has a higher recognition accuracy. In our work, the near-infrared charge-coupled device (CCD) camera is adopted as an input device for capturing dorsal hand vein images, it has the advantages of the low-cost and noncontact imaging. In the proposed approach, two finger-peaks are automatically selected as the datum points to define the region of interest (ROI) in the dorsal hand vein images. The modified two-directional two-dimensional principal component analysis, which performs an alternate two-dimensional PCA (2DPCA) in the column direction of images in the 2DPCA subspace, is proposed to exploit the correlation of vein features inside the ROI between images. The major advantage of the proposed method is that it requires fewer coefficients for efficient dorsal hand vein image representation and recognition. The experimental results on our large dorsal hand vein database show that the presented schema achieves promising performance (false reject rate: 0.97% and false acceptance rate: 0.05%) and is feasible for dorsal hand vein recognition.

  2. On dynamics of uranium vein mineralization

    International Nuclear Information System (INIS)

    Petrosyan, R.V.

    1981-01-01

    The formation of urnaium vein deposits and the essence of consanguinity of the mineralization and wall metasomatites are considered. The formation of uranium mineralization is analysed from the positions of Korzhinsky D. S. : the formation of metasomatite aureole and associated vein ores take place as a result of the development of one solution flow while the formation of mineral vein associations occurs on the background of contineous filtration of the solution during metasomato is due to a repeated (pulse) half-opening of fractures and their filling with a part of filtrating solution. The analysis of the available information on the example of two different uranium manifestations permits to reveal certain relations both in the character of wall rock alterations and between the metasomatosis and the formation of ore minerals in veins. The conclusion is made that spatial-time correlations of vein formations with wall metasomatites attest that the pulse formation of ores in veinlets occurs on the background and in interrelation with a consecutive precipitation of components in the aureole volume. The analysis of element migration dynamics in wall aureole carried out from the positions of the Korzhinsky hypothesis of the advance wave of acid components that takes into account the interaction of continuous and pulse mechanisms of solution movement permits to avoid contradictions when interpreting the processes of wall rock alterations and vein ore-forming, and permits to make a common scheme of vein ore-genesis [ru

  3. The Compartment Syndrome Associated with Deep Vein Thrombosis due to Rattlesnake Bite: A Case Report

    Directory of Open Access Journals (Sweden)

    Radu Ciprian Tincu

    2017-08-01

    Full Text Available Background: Snakebite is a health issue specific to some parts of the world, especially in the tropical area, where it produces many victims. The main clinical damage caused by snake bite involves hemotoxic, neurotoxic and myotoxic reactions. It is also established that the importance of systemic impairment varies according to individual factors and are related to organ dysfunction, shock or hypotension. We report the case of a young woman suffering from snakebite who developed deep vein thrombosis and compartment syndrome. Case Report: We present the case of a 32-year-old Romanian woman who was injured by her own Crotalinae snake (also known as pit viper or rattlesnake on her left forearm. When admitted to our Emergency Department, she was conscious with a Glasgow coma scale of 12/15, somnolent, febrile, suffering of headache, tachypnea; the marks of the snakebite were located in the distal part of the anterior left forearm; she had pain and bleeding at the bite site and swelling of the left upper limb with lymphangitis up to the axilla. She experienced fasciotomy-requiring compartment syndrome of the upper limb and required unfractionated heparin and closed monitored using activated partial thromboplastin time evolution due micro-thrombosis in the brachial vein. Local improvement was achieved in the next 4 days with progressive diminish of local tenderness and swelling. Conclusion: Limb deep vein thrombosis might be induced by snakebite, despite pro-hemorrhagic general condition induced by the envenomation. High index of clinical suspicion is needed for early diagnosis and timely management which can improve survival of these patients

  4. Valsalva and gravitational variability of the internal jugular vein and common femoral vein: Ultrasound assessment

    Energy Technology Data Exchange (ETDEWEB)

    Beddy, P. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)]. E-mail: pbeddy@eircom.net; Geoghegan, T. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Ramesh, N. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Buckley, O. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); O' Brien, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Colville, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Torreggiani, W.C. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)

    2006-05-15

    Purpose: Central venous cannulation via the common femoral vein is an important starting point for many interventions. The purpose of this study was to determine the optimum conditions for cannulation of the femoral vein and to compare these with the relative changes in the internal jugular vein. Methods: High-resolution 2D ultrasound was utilised to determine variability of the calibre of the femoral and internal jugular veins in 10 healthy subjects. Venous diameter was assessed during the Valsalva manoeuvre and in different degrees of the Trendelenburg position. Results: The Valsalva manoeuvre significantly increased the size of the femoral and internal jugular veins. There was a relatively greater increase in femoral vein diameter when compared with the internal jugular vein of 40 and 29%, respectively. Changes in body inclination (Trendelenburg position) did not significantly alter the luminal diameter of the femoral vein. However, it significantly increased internal jugular vein diameter. Conclusions: Femoral vein cannulation is augmented by the Valsalva manoeuvre but not significantly altered by the gravitational position of the subject.

  5. Analytic solutions of hydrodynamics equations

    International Nuclear Information System (INIS)

    Coggeshall, S.V.

    1991-01-01

    Many similarity solutions have been found for the equations of one-dimensional (1-D) hydrodynamics. These special combinations of variables allow the partial differential equations to be reduced to ordinary differential equations, which must then be solved to determine the physical solutions. Usually, these reduced ordinary differential equations are solved numerically. In some cases it is possible to solve these reduced equations analytically to obtain explicit solutions. In this work a collection of analytic solutions of the 1-D hydrodynamics equations is presented. These can be used for a variety of purposes, including (i) numerical benchmark problems, (ii) as a basis for analytic models, and (iii) to provide insight into more complicated solutions

  6. Diagnostic value of color doppler ultrasonography in detecting stenosis and occlusion of central veins in patients with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Masoud Pezeshki Rad

    2015-01-01

    Full Text Available Venography is an invasive diagnostic test that uses contrast material that provides a picture of the condition of the veins. But, complications, including adverse effects on the kidney, do occur. On the other hand, with the current technological development, application of ultrasound in the diagnosis of obstructive diseases of the veins is gaining popularity, being non-invasive, easy to perform and cost-effective. The aim of this study was to evaluate the diagnostic value of Doppler sonography in the diagnosis of central vein stenosis. In this descriptive-analytical study, 41 hemodialysis patients who had been referred for 50 upper limb venographies to the radiology department of Imam Reza (AS were included. Patients with chronic kidney disease with a history of catheterization of the vein, jugular or subclavian, and who had established fistulas or synthetic vascular grafts were targeted. Central venous ultrasound was performed on both sides to evaluate stenosis or occlusion. Venography was performed by the radiologist the next day or the day before hemodialysis. Data on demographic characteristics, findings of clinical examination and findings of ultrasound as well as venography were recorded by using the SPSS software, Chi-square test and Spearman correlation, and Kappa agreement was calculated for sensitivity, specificity and predictive values. Twenty-three (56% patients were male subjects and 18 patients (44% were female. Twenty-three (56% patients of the study population were aged 60 years. The overall sensitivity, specificity and positive predictive value and negative predictive value of Doppler sonography in the proximal veins in hemodialysis patients compared with venography were, respectively, 80.9%, 79.3%, 73.9% and 85.1%. Color Doppler sonography, as a non-invasive method, could be a good alternative for venography in the assessment of the upper limb with central vein stenosis and occlusion.

  7. Diagnostic value of color doppler ultrasonography in detecting stenosis and occlusion of central veins in patients with chronic kidney disease.

    Science.gov (United States)

    Rad, Masoud Pezeshki; Kazemzadeh, Gholam Hosain; Ziaee, Masood; Azarkar, Ghodsieh

    2015-03-01

    Venography is an invasive diagnostic test that uses contrast material that provides a picture of the condition of the veins. But, complications, including adverse effects on the kidney, do occur. On the other hand, with the current technological development, application of ultrasound in the diagnosis of obstructive diseases of the veins is gaining popularity, being non-invasive, easy to perform and cost-effective. The aim of this study was to evaluate the diagnostic value of Doppler sonography in the diagnosis of central vein stenosis. In this descriptive-analytical study, 41 hemodialysis patients who had been referred for 50 upper limb venographies to the radiology department of Imam Reza (AS) were included. Patients with chronic kidney disease with a history of catheterization of the vein, jugular or subclavian, and who had established fistulas or synthetic vascular grafts were targeted. Central venous ultrasound was performed on both sides to evaluate stenosis or occlusion. Venography was performed by the radiologist the next day or the day before hemodialysis. Data on demographic characteristics, findings of clinical examination and findings of ultrasound as well as venography were recorded by using the SPSS software, Chi-square test and Spearman correlation, and Kappa agreement was calculated for sensitivity, specificity and predictive values. Twenty-three (56%) patients were male subjects and 18 patients (44%) were female. Twenty-three (56%) patients of the study population were aged 60 years. The overall sensitivity, specificity and positive predictive value and negative predictive value of Doppler sonography in the proximal veins in hemodialysis patients compared with venography were, respectively, 80.9%, 79.3%, 73.9% and 85.1%. Color Doppler sonography, as a non-invasive method, could be a good alternative for venography in the assessment of the upper limb with central vein stenosis and occlusion.

  8. Laser driven hydrodynamic instability experiments

    International Nuclear Information System (INIS)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1993-01-01

    An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils allow a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes

  9. Rapidity correlations test stochastic hydrodynamics

    International Nuclear Information System (INIS)

    Zin, C; Gavin, S; Moschelli, G

    2017-01-01

    We show that measurements of the rapidity dependence of transverse momentum correlations can be used to determine the characteristic time τ π that dictates the rate of isotropization of the stress energy tensor, as well as the shear viscosity ν = η/sT . We formulate methods for computing these correlations using second order dissipative hydrodynamics with noise. Current data are consistent with τ π /ν ∼ 10 but targeted measurements can improve this precision. (paper)

  10. Hydrodynamic simulations of expanding shells

    Czech Academy of Sciences Publication Activity Database

    Wünsch, Richard; Palouš, Jan; Ehlerová, Soňa

    2004-01-01

    Roč. 289, 3-4 (2004), s. 35-36 ISSN 0004-640X. [From observation to self-consistent modelling of the ISM in galaxies. Porto, 03.09.2002-05.09.2002] R&D Projects: GA AV ČR KSK1048102 Keywords : hydrodynamic simulations * ISM * star formation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.597, year: 2004

  11. Hydrodynamic Limit of Multiple SLE

    Science.gov (United States)

    Hotta, Ikkei; Katori, Makoto

    2018-04-01

    Recently del Monaco and Schleißinger addressed an interesting problem whether one can take the limit of multiple Schramm-Loewner evolution (SLE) as the number of slits N goes to infinity. When the N slits grow from points on the real line R in a simultaneous way and go to infinity within the upper half plane H, an ordinary differential equation describing time evolution of the conformal map g_t(z) was derived in the N → ∞ limit, which is coupled with a complex Burgers equation in the inviscid limit. It is well known that the complex Burgers equation governs the hydrodynamic limit of the Dyson model defined on R studied in random matrix theory, and when all particles start from the origin, the solution of this Burgers equation is given by the Stieltjes transformation of the measure which follows a time-dependent version of Wigner's semicircle law. In the present paper, first we study the hydrodynamic limit of the multiple SLE in the case that all slits start from the origin. We show that the time-dependent version of Wigner's semicircle law determines the time evolution of the SLE hull, K_t \\subset H\\cup R, in this hydrodynamic limit. Next we consider the situation such that a half number of the slits start from a>0 and another half of slits start from -a exact solutions, we will discuss the universal long-term behavior of the multiple SLE and its hull K_t in the hydrodynamic limit.

  12. Hydrodynamical model with massless constituents

    International Nuclear Information System (INIS)

    Chiu, C.B.; Wang, K.H.

    1974-01-01

    Within the constituent hydrodynamical model, it is shown that the total number of constituents is conserved, if these constituents are massless and satisfy the Fermi-Dirac distribution. A simple scheme for the transition from the constituent-phase to the hadron-phase is suggested, and the hadron inclusive momentum spectra are presented for this case. This phase transition scheme predicts the average transverse momentum of meson resonances which is compatible with the data. (U.S.)

  13. Muscle and Limb Mechanics.

    Science.gov (United States)

    Tsianos, George A; Loeb, Gerald E

    2017-03-16

    Understanding of the musculoskeletal system has evolved from the collection of individual phenomena in highly selected experimental preparations under highly controlled and often unphysiological conditions. At the systems level, it is now possible to construct complete and reasonably accurate models of the kinetics and energetics of realistic muscles and to combine them to understand the dynamics of complete musculoskeletal systems performing natural behaviors. At the reductionist level, it is possible to relate most of the individual phenomena to the anatomical structures and biochemical processes that account for them. Two large challenges remain. At a systems level, neuroscience must now account for how the nervous system learns to exploit the many complex features that evolution has incorporated into muscle and limb mechanics. At a reductionist level, medicine must now account for the many forms of pathology and disability that arise from the many diseases and injuries to which this highly evolved system is inevitably prone. © 2017 American Physiological Society. Compr Physiol 7:429-462, 2017. Copyright © 2017 John Wiley & Sons, Inc.

  14. Black Hole Scrambling from Hydrodynamics.

    Science.gov (United States)

    Grozdanov, Sašo; Schalm, Koenraad; Scopelliti, Vincenzo

    2018-06-08

    We argue that the gravitational shock wave computation used to extract the scrambling rate in strongly coupled quantum theories with a holographic dual is directly related to probing the system's hydrodynamic sound modes. The information recovered from the shock wave can be reconstructed in terms of purely diffusionlike, linearized gravitational waves at the horizon of a single-sided black hole with specific regularity-enforced imaginary values of frequency and momentum. In two-derivative bulk theories, this horizon "diffusion" can be related to late-time momentum diffusion via a simple relation, which ceases to hold in higher-derivative theories. We then show that the same values of imaginary frequency and momentum follow from a dispersion relation of a hydrodynamic sound mode. The frequency, momentum, and group velocity give the holographic Lyapunov exponent and the butterfly velocity. Moreover, at this special point along the sound dispersion relation curve, the residue of the retarded longitudinal stress-energy tensor two-point function vanishes. This establishes a direct link between a hydrodynamic sound mode at an analytically continued, imaginary momentum and the holographic butterfly effect. Furthermore, our results imply that infinitely strongly coupled, large-N_{c} holographic theories exhibit properties similar to classical dilute gases; there, late-time equilibration and early-time scrambling are also controlled by the same dynamics.

  15. Numerical Hydrodynamics in Special Relativity.

    Science.gov (United States)

    Martí, José Maria; Müller, Ewald

    2003-01-01

    This review is concerned with a discussion of numerical methods for the solution of the equations of special relativistic hydrodynamics (SRHD). Particular emphasis is put on a comprehensive review of the application of high-resolution shock-capturing methods in SRHD. Results of a set of demanding test bench simulations obtained with different numerical SRHD methods are compared. Three applications (astrophysical jets, gamma-ray bursts and heavy ion collisions) of relativistic flows are discussed. An evaluation of various SRHD methods is presented, and future developments in SRHD are analyzed involving extension to general relativistic hydrodynamics and relativistic magneto-hydrodynamics. The review further provides FORTRAN programs to compute the exact solution of a 1D relativistic Riemann problem with zero and nonzero tangential velocities, and to simulate 1D relativistic flows in Cartesian Eulerian coordinates using the exact SRHD Riemann solver and PPM reconstruction. Supplementary material is available for this article at 10.12942/lrr-2003-7 and is accessible for authorized users.

  16. Anomalous adrenal vein anatomy complicating the evaluation of primary hyperaldosteronism

    Directory of Open Access Journals (Sweden)

    Kaitlin M. Ford, BS

    2018-02-01

    Full Text Available Adrenal vein development in utero occurs concurrently with the development of the inferior vena cava, the renal veins, and the gonadal veins. The embryologic formation of these veins involves communication of various venous systems. Although the left adrenal-renal vein complex is most commonly described as a shared emptying of the left adrenal vein and the left inferior phrenic vein into the left renal vein, there have been reports of numerous anatomic variations of this complex. In this report, we present a case of a rare variant of the left adrenal vein, in which the left adrenal vein empties into the left gonadal vein, which takes an atypical course superolateral to the left kidney.

  17. Lower-Limb Wearable Exoskeleton

    OpenAIRE

    Pons, J.L.; Moreno, J.C.; Brunetti, F.J.; Rocon, E.

    2007-01-01

    The differences found in the patients' kinematic gait patterns during the application of functional compensation on the lower limb showed significant differences regarding the subjects' usual gait. In both patients rapid adaptations were observed and new motor commands were learnt necessary for managing the exoskeleton with the constraints imposed on the limb. The benefits of the correct release of the knee in both instances is clear evidence of approximating their gait patterns to the normal...

  18. Artificial limb representation in amputees

    OpenAIRE

    van den Heiligenberg, FMZ; Orlov, T; Macdonald, SN; Duff, EP; Henderson Slater, JDE; Beckmann, CF; Johansen-Berg, H; Culham, JC; Makin, TR

    2018-01-01

    The human brain contains multiple hand-selective areas, in both the sensorimotor and visual systems. Could our brain repurpose neural resources, originally developed for supporting hand function, to represent and control artificial limbs? We studied individuals with congenital or acquired hand-loss (hereafter one-handers) using functional MRI. We show that the more one-handers use an artificial limb (prosthesis) in their everyday life, the stronger visual hand-selective areas in the lateral o...

  19. Physiotherapy after amputation of the limb

    OpenAIRE

    Pospíšil, Daniel

    2010-01-01

    In this bachelor thesis the author considers physiotherapy after amputation of the lower limb. The theoretical section describes the anatomy of the lower limb, a procedure for amputation of the lower limb, occupational theraoy and prosthesis. The author then goes on to discuss physiotherapy in relation to two case studies of patients who have had their lower limbs removed.

  20. Complications of umbilical vein catherisation. Case Report

    International Nuclear Information System (INIS)

    Bothur-Nowacka, J.; Czech-Kowalska, J.; Gruszfeld, D.; Nowakowska-Rysz, M.; Dobrzanska, A.; Kosciesza, A.; Polnik, D.

    2011-01-01

    Umbilical vein catheterization is a relatively easy procedure performed routinely on the neonate intensive care units. It provides a fast central vein access, but some complications have been described in the literature. Case Reports: We presented a case report of a premature infant (34 hbd) with extravasation of the parenteral nutrition and drugs to the liver after umbilical vein catheterization. Fever and increasing biochemical markers of infection were observed. USG revealed a heterogenic, well-limited space of 4 cm in diameter, located in the right lobe of the liver. CT excluded liver abscess. Considering neoplastic process or incorrect location of the catheter of the central vein, we performed liver biopsy. Results: Cytological and biochemical analysis of the aspirated fluid revealed extravasation of parenteral nutrition to the liver.Our case confirms the necessity of controlling a proper location of the central catheter right after its insertion and during hospitalization. (authors)

  1. The Dependence of Solar Flare Limb Darkening on Emission Peak Formation Temperature

    Science.gov (United States)

    Thiemann, Edward; Epp, Luke; Eparvier, Francis; Chamberlin, Phillip C.

    2017-08-01

    Solar limb effects are local brightening or darkening of an emission that depend on where in the Sun's atmosphere it forms. Near the solar limb, optically thick (thin) emissions will darken (brighten) as the column of absorbers (emitters) along the line-of-sight increases. Note that in limb brightening, emission sources are re-arranged whereas in limb darkening they are obscured. Thus, only limb darkening is expected to occur in disk integrated observations. Limb darkening also results in center-to-limb variations of disk-integrated solar flare spectra, with important consequences for how planetary atmospheres are affected by flares. Flares are typically characterized by their flux in the optically thin 0.1-0.8 nm band measured by the X-ray Sensor (XRS) on board the Geostationary Operational Environmental Satellite (GOES). On the other hand, Extreme Ultraviolet (EUV) line emissions can limb darken because they are sensitive to resonant scattering, resulting in a flare's location on the solar disk controlling the amount of ionizing radiation that reaches a planet. For example, an X-class flare originating from disk center may significantly heat a planet's thermosphere, whereas the same flare originating near the limb may have no effect because much of the effective emissions are scattered in the solar corona.To advance the relatively poor understanding of flare limb darkening, we use over 300 M-class or larger flares observed by the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) to characterize limb darkening as a function of emission peak formation temperature, Tf. For hot coronal emissions (Tf>2 MK), these results show a linear relationship between the degree of limb darkening and Tf where lines with Tf=2 MK darken approximately 7 times more than lines with Tf=16 MK. Because the extent of limb darkening is dependent on the height of the source plasma, we use simple Beer-Lambert radiative transfer analysis to interpret these results

  2. Entropy-limited hydrodynamics: a novel approach to relativistic hydrodynamics

    Science.gov (United States)

    Guercilena, Federico; Radice, David; Rezzolla, Luciano

    2017-07-01

    We present entropy-limited hydrodynamics (ELH): a new approach for the computation of numerical fluxes arising in the discretization of hyperbolic equations in conservation form. ELH is based on the hybridisation of an unfiltered high-order scheme with the first-order Lax-Friedrichs method. The activation of the low-order part of the scheme is driven by a measure of the locally generated entropy inspired by the artificial-viscosity method proposed by Guermond et al. (J. Comput. Phys. 230(11):4248-4267, 2011, doi: 10.1016/j.jcp.2010.11.043). Here, we present ELH in the context of high-order finite-differencing methods and of the equations of general-relativistic hydrodynamics. We study the performance of ELH in a series of classical astrophysical tests in general relativity involving isolated, rotating and nonrotating neutron stars, and including a case of gravitational collapse to black hole. We present a detailed comparison of ELH with the fifth-order monotonicity preserving method MP5 (Suresh and Huynh in J. Comput. Phys. 136(1):83-99, 1997, doi: 10.1006/jcph.1997.5745), one of the most common high-order schemes currently employed in numerical-relativity simulations. We find that ELH achieves comparable and, in many of the cases studied here, better accuracy than more traditional methods at a fraction of the computational cost (up to {˜}50% speedup). Given its accuracy and its simplicity of implementation, ELH is a promising framework for the development of new special- and general-relativistic hydrodynamics codes well adapted for massively parallel supercomputers.

  3. Primary leiomyosarcoma of the innominate vein.

    Science.gov (United States)

    Illuminati, Giulio; Miraldi, Fabio; Mazzesi, Giuseppe; D'urso, Antonio; Ceccanei, Gianluca; Bezzi, Marcello

    2007-01-01

    Primary venous leiomyosarcoma is rare. We report the case of a primary leiomyosarcoma of the left innominate vein, with neoplastic thrombus extending into the left jugular and subclavian veins. The tumor was curatively resected en bloc with anterior mediastinal and laterocervical lymphatics, through a median sternotomy prolonged into left cervicotomy. Primary venous sarcomas may be associated with prolonged survival in individual cases, with curative resection recommended as the standard treatment, in the absence of distant spread.

  4. The umbilical and paraumbilical veins of man.

    OpenAIRE

    Martin, B F; Tudor, R G

    1980-01-01

    During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persis...

  5. Deep vein thrombosis of the leg

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hee; Rhee, Kwang Woo; Jeon, Suk Chul; Joo, Kyung Bin; Lee, Seung Ro; Seo, Heung Suk; Hahm, Chang Kok [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    1987-04-15

    Ascending contrast venography is the definitive standard method for the diagnosis of deep vein thrombosis (DVT) of the lower extremities. Authors analysed 22 cases of DVT clinically and radiographically. 1.The patients ranged in age from 15 to 70 yrs and the most prevalent age group was 7th decade (31%). There was an equal distribution of males and females. 2.In 11 cases of 22 cases, variable etiologic factors were recognized, such as abdominal surgery, chronic bedridden state, local trauma on the leg, pregnancy, postpartum, Behcet's syndrome, iliac artery aneurysm, and chronic medication of estrogen. 3.Nineteen cases out of 22 cases showed primary venographic signs of DVT, such as well-defined filling defect in opacified veins and narrowed, irregularly filled venous lumen. In only 3 cases, the diagnosis of DVT was base upon the segmental nonvisualization of deep veins with good opacification of proximal and distal veins and presence of collaterals. 4.Extent of thrombosis: 3 cases were confined to calf vein, 4 cases extended to femoral vein, and 15 cases had involvement above iliac vein. 5.In 17 cases involving relatively long segment of deep veins, propagation pattern of thrombus was evaluated by its radiologic morphology according to the age of thrombus: 9 cases suggested central or antegrade propagation pattern and 8 cases, peripheral or retrograde pattern. 6.None of 22 cases showed clinical evidence of pulmonary embolism. The cause of the rarity of pulmonary embolism in Korean in presumed to be related to the difference in major involving site and propagation pattern of DVT in the leg.

  6. Deep vein thrombosis of the leg

    International Nuclear Information System (INIS)

    Lee, Eun Hee; Rhee, Kwang Woo; Jeon, Suk Chul; Joo, Kyung Bin; Lee, Seung Ro; Seo, Heung Suk; Hahm, Chang Kok

    1987-01-01

    Ascending contrast venography is the definitive standard method for the diagnosis of deep vein thrombosis (DVT) of the lower extremities. Authors analysed 22 cases of DVT clinically and radiographically. 1.The patients ranged in age from 15 to 70 yrs and the most prevalent age group was 7th decade (31%). There was an equal distribution of males and females. 2.In 11 cases of 22 cases, variable etiologic factors were recognized, such as abdominal surgery, chronic bedridden state, local trauma on the leg, pregnancy, postpartum, Behcet's syndrome, iliac artery aneurysm, and chronic medication of estrogen. 3.Nineteen cases out of 22 cases showed primary venographic signs of DVT, such as well-defined filling defect in opacified veins and narrowed, irregularly filled venous lumen. In only 3 cases, the diagnosis of DVT was base upon the segmental nonvisualization of deep veins with good opacification of proximal and distal veins and presence of collaterals. 4.Extent of thrombosis: 3 cases were confined to calf vein, 4 cases extended to femoral vein, and 15 cases had involvement above iliac vein. 5.In 17 cases involving relatively long segment of deep veins, propagation pattern of thrombus was evaluated by its radiologic morphology according to the age of thrombus: 9 cases suggested central or antegrade propagation pattern and 8 cases, peripheral or retrograde pattern. 6.None of 22 cases showed clinical evidence of pulmonary embolism. The cause of the rarity of pulmonary embolism in Korean in presumed to be related to the difference in major involving site and propagation pattern of DVT in the leg

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

    Directory of Open Access Journals (Sweden)

    G Raghavendra Prasad

    2013-01-01

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

  8. Veins improve fracture toughness of insect wings.

    Directory of Open Access Journals (Sweden)

    Jan-Henning Dirks

    Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

  9. Transvenous liver biopsy via the femoral vein

    International Nuclear Information System (INIS)

    Khosa, F.; McNulty, J.G.; Hickey, N.; O'Brien, P.; Tobin, A.; Noonan, N.; Ryan, B.; Keeling, P.W.N.; Kelleher, D.P.; McDonald, G.S.A.

    2003-01-01

    AIM: To study the safety, effectiveness and diagnostic value of transvenous forceps biopsy of the liver in 54 patients with coagulopathy, gross ascites or morbid obesity and suspected liver disease in whom percutaneous liver biopsy was contraindicated. MATERIAL AND METHODS: Forceps biopsy of the liver via the femoral vein was attempted in 54 adult patients with advanced liver disease of unknown aetiology who had coagulation disorders (41 cases), gross ascites (11 cases) or morbid obesity (two cases). In each patient two to six biopsies (average four) were taken using a radial jaw forceps inserted via the right or left femoral vein. RESULTS: The procedure was successful in 53 cases. Hepatic vein catheterization failed in one patient. Adequate liver tissue for diagnosis was obtained in 84% of cases. One patient developed delayed haemorrhage at 12 h from a capsular leak that was undetected during the biopsy procedure. This patient required blood transfusions and laparotomy to control bleeding. There were no deaths in the 53 patients studied. Transient minor chest and shoulder pain was encountered during sheath insertion into a hepatic vein in 23 patients. Three patients developed a femoral vein haematoma, which resolved with conservative treatment. CONCLUSION: Transvenous liver biopsy via the femoral vein is another safe, effective, simple alternative technique of biopsy when the percutaneous route is contraindicated

  10. Solitonic Dispersive Hydrodynamics: Theory and Observation

    Science.gov (United States)

    Maiden, Michelle D.; Anderson, Dalton V.; Franco, Nevil A.; El, Gennady A.; Hoefer, Mark A.

    2018-04-01

    Ubiquitous nonlinear waves in dispersive media include localized solitons and extended hydrodynamic states such as dispersive shock waves. Despite their physical prominence and the development of thorough theoretical and experimental investigations of each separately, experiments and a unified theory of solitons and dispersive hydrodynamics are lacking. Here, a general soliton-mean field theory is introduced and used to describe the propagation of solitons in macroscopic hydrodynamic flows. Two universal adiabatic invariants of motion are identified that predict trapping or transmission of solitons by hydrodynamic states. The result of solitons incident upon smooth expansion waves or compressive, rapidly oscillating dispersive shock waves is the same, an effect termed hydrodynamic reciprocity. Experiments on viscous fluid conduits quantitatively confirm the soliton-mean field theory with broader implications for nonlinear optics, superfluids, geophysical fluids, and other dispersive hydrodynamic media.

  11. The origin of vertebrate limbs.

    Science.gov (United States)

    Coates, M I

    1994-01-01

    The earliest tetrapod limbs are polydactylous, morphologically varied and do not conform to an archetypal pattern. These discoveries, combined with the unravelling of limb developmental morphogenetic and regulatory mechanisms, have prompted a re-examination of vertebrate limb evolution. The rich fossil record of vertebrate fins/limbs, although restricted to skeletal tissues, exceeds the morphological diversity of the extant biota, and a systematic approach to limb evolution produces an informative picture of evolutionary change. A composite framework of several phylogenetic hypotheses is presented incorporating living and fossil taxa, including the first report of an acanthodian metapterygium and a new reconstruction of the axial skeleton and caudal fin of Acanthostega gunnari. Although significant nodes in vertebrate phylogeny remain poorly resolved, clear patterns of morphogenetic evolution emerge: median fin origination and elaboration initially precedes that of paired fins; pectoral fins initially precede pelvic fin development; evolving patterns of fin distribution, skeletal tissue diversity and structural complexity become decoupled with increased taxonomic divergence. Transformational sequences apparent from the fish-tetrapod transition are reiterated among extant lungfishes, indicating further directions for comparative experimental research. The evolutionary diversification of vertebrate fin and limb patterns challenges a simple linkage between Hox gene conservation, expression and morphology. A phylogenetic framework is necessary in order to distinguish shared from derived characters in experimental model regulatory systems. Hox and related genomic evolution may include convergent patterns underlying functional and morphological diversification. Brachydanio is suggested as an example where tail-drive patterning demands may have converged with the regulation of highly differentiated limbs in tetrapods.

  12. Annual Report: Hydrodynamics and Radiative Hydrodynamics with Astrophysical Applications

    Energy Technology Data Exchange (ETDEWEB)

    R. Paul Drake

    2005-12-01

    We report the ongoing work of our group in hydrodynamics and radiative hydrodynamics with astrophysical applications. During the period of the existing grant, we have carried out two types of experiments at the Omega laser. One set of experiments has studied radiatively collapsing shocks, obtaining high-quality scaling data using a backlit pinhole and obtaining the first (ever, anywhere) Thomson-scattering data from a radiative shock. Other experiments have studied the deeply nonlinear development of the Rayleigh-Taylor (RT) instability from complex initial conditions, obtaining the first (ever, anywhere) dual-axis radiographic data using backlit pinholes and ungated detectors. All these experiments have applications to astrophysics, discussed in the corresponding papers either in print or in preparation. We also have obtained preliminary radiographs of experimental targets using our x-ray source. The targets for the experiments have been assembled at Michigan, where we also prepare many of the simple components. The above activities, in addition to a variety of data analysis and design projects, provide good experience for graduate and undergraduates students. In the process of doing this research we have built a research group that uses such work to train junior scientists.

  13. [A reduction in the invasiveness during surgical revascularization: the harvesting of the great saphenous vein by a video endoscopic technic].

    Science.gov (United States)

    Terrini, A; Graffigna, A; Martinelli, L

    2000-05-01

    The authors report their preliminary experience of endoscopic saphenous vein harvesting as part of a program devoted to reducing the invasivity of surgical myocardial revascularization. This method allows us to minimize the cutaneous incisions in the inferior limbs necessary to harvest the saphenous vein, thus reducing the incidence of complications. The study includes 41 patients who underwent endoscopic saphenous vein harvesting from October 1998 to September 1999 and, as a control group, 20 patients with similar characteristics operated on with the traditional technique during the same period. The variables considered were: the time necessary to harvest the saphenous vein, the incidence of complications, and the postoperative mobilization. All the endoscopically harvested grafts were adequate for the scheduled procedure. The only complication occurred in a patient operated on with the traditional technique. The time of harvesting and the day of mobilization were similar in the two groups. The reduction of surgical trauma allowed a fast deambulation recovery and better esthetic results. When complete arterial revascularization is not feasible, the endoscopic harvesting of the required saphenous vein segment allows for a significant reduction in the invasivity of the procedure.

  14. Hydrodynamic interactions in active colloidal crystal microrheology

    OpenAIRE

    Weeber, R; Harting, JDR Jens

    2012-01-01

    In dense colloids it is commonly assumed that hydrodynamic interactions do not play a role. However, a found theoretical quantification is often missing. We present computer simulations that are motivated by experiments where a large colloidal particle is dragged through a colloidal crystal. To qualify the influence of long-ranged hydrodynamics, we model the setup by conventional Langevin dynamics simulations and by an improved scheme with limited hydrodynamic interactions. This scheme signif...

  15. Disruptive Innovation in Numerical Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Waltz, Jacob I. [Los Alamos National Laboratory

    2012-09-06

    We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.

  16. Laser driven hydrodynamic instability experiments

    International Nuclear Information System (INIS)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1992-01-01

    We have conducted an extensive series of experiments on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime; multimode foils allow an assessment of the degree of mode coupling; and surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes. Experimental results and comparisons with theory and simulations are presented

  17. Hydrodynamics of post CHF region

    International Nuclear Information System (INIS)

    Ishii, M.; De Jarlais, G.

    1984-04-01

    Among various two-phase flow regimes, the inverted flow in the post-dryout region is relatively less well understood due to its special heat transfer conditions. The review of existing data indicates further research is needed in the areas of basic hydrodynamics related to liquid core disintegration mechanisms, slug and droplet formations, entrainment, and droplet size distributions. In view of this, the inverted flow is studied in detail both analytically and experimentally. Criteria for initial flow regimes in the post-dryout region are given. Preliminary models for subsequent flow regime transition criteria are derived together with correlations for a mean droplet diameter based on the adiabatic simulation data

  18. Problems in astrophysical radiation hydrodynamics

    International Nuclear Information System (INIS)

    Castor, J.I.

    1983-01-01

    The basic equations of radiation hydrodynamics are discussed in the regime that the radiation is dynamically as well as thermally important. Particular attention is paid to the question of what constitutes an acceptable approximate non-relativistic system of dynamical equations for matter and radiation in this regime. Further discussion is devoted to two classes of application of these ideas. The first class consists of problems dominated by line radiation, which is sensitive to the velocity field through the Doppler effect. The second class is of problems in which the advection of radiation by moving matter dominates radiation diffusion

  19. Induced chorioretinal venous anastomosis in experimental retinal branch vein occlusion.

    OpenAIRE

    McAllister, I L; Yu, D Y; Vijayasekaran, S; Barry, C; Constable, I

    1992-01-01

    Iatrogenic retinal vein to choroidal vein anastomoses were created using laser photocoagulation in six of seven dog eyes in which a partial branch retinal vein occlusion had previously been created photochemically. A similar attempt to create an anastomosis was made in six control eyes in which no branch vein occlusion was present. In the eyes in which a branch retinal vein had been created, a venous chorioretinal anastomosis appeared to be present by 3 to 6 weeks. In three control eyes simil...

  20. The CT appearance of the superior intercostal veins

    International Nuclear Information System (INIS)

    Lund, G.

    1982-01-01

    The CT appearance of the superior intercostal veins is described. The veins are more frequently seen on the right side. The right superior intercostal vein should not be misinterpreted as a paraspinal mass when it is large or bulges into the contour of the right lung. A case of stenosis of the left brachiocephalic vein is shown, where the left superior intercostal vein serves as a collateral. (orig.)

  1. Duplication of the Portal Vein: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Won; Shin, Hyeong Cheol; Jou, Sung Shick; Han, Jong Kyu; Kim, Il Young [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of)

    2009-12-15

    The duplication of the portal vein is an uncommon congenital anomaly. To date, only four cases have been reported in the medical literature. This anomaly can cause portal hypertension in pediatric patients. In addition, duplication of the portal vein has various patterns of connection with a splenic vein or mesenteric veins, and it can lie anterior or posterior to the duodenum. We report the MDCT findings of an adult patient with duplication of the portal vein that was found incidentally

  2. Gonadal vein tumor thrombosis due to renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Hamidreza Haghighatkhah

    2015-01-01

    Full Text Available Renal cell carcinoma (RCC had a tendency to extend into the renal vein and inferior vena cava, while extension into the gonadal vein has been rarely reported. Gonadal vein tumor thrombosis appears as an enhancing filling defect within the dilated gonadal vein anterior to the psoas muscle and shows an enhancement pattern identical to that of the original tumor. The possibility of gonadal vein thrombosis should be kept in mind when looking at an imaging study of patients with RCC

  3. Hydrodynamics and stellar winds an introduction

    CERN Document Server

    Maciel, Walter J

    2014-01-01

    Stellar winds are a common phenomenon in the life of stars, from the dwarfs like the Sun to the red giants and hot supergiants, constituting one of the basic aspects of modern astrophysics. Stellar winds are a hydrodynamic phenomenon in which circumstellar gases expand towards the interstellar medium. This book presents an elementary introduction to the fundamentals of hydrodynamics with an application to the study of stellar winds. The principles of hydrodynamics have many other applications, so that the book can be used as an introduction to hydrodynamics for students of physics, astrophysics and other related areas.

  4. Hydrodynamic interactions in active colloidal crystal microrheology.

    Science.gov (United States)

    Weeber, R; Harting, J

    2012-11-01

    In dense colloids it is commonly assumed that hydrodynamic interactions do not play a role. However, a found theoretical quantification is often missing. We present computer simulations that are motivated by experiments where a large colloidal particle is dragged through a colloidal crystal. To qualify the influence of long-ranged hydrodynamics, we model the setup by conventional Langevin dynamics simulations and by an improved scheme with limited hydrodynamic interactions. This scheme significantly improves our results and allows to show that hydrodynamics strongly impacts the development of defects, the crystal regeneration, as well as the jamming behavior.

  5. Corrosion cast study of the canine hepatic veins.

    Science.gov (United States)

    Uršič, M; Vrecl, M; Fazarinc, G

    2014-11-01

    This study presents a detailed description of the distribution, diameters and drainage patterns of hepatic veins on the basis of the corrosion cast analysis in 18 dogs. We classified the hepatic veins in three main groups: the right hepatic veins of the caudate process and right lateral liver lobe, the middle hepatic veins of the right medial and quadrate lobes and the left hepatic veins of both left liver lobes and the papillary process. The corrosion cast study showed that the number of the veins in the Nomina Anatomica Veterinaria and most anatomical textbooks is underestimated. The number of various-sized hepatic veins of the right liver division ranged from 3 to 5 and included 1 to 4 veins from the caudate process and 2 to 4 veins from the right lateral liver lobe. Generally, in all corrosion casts, one middle-sized vein from the right part of the right medial lobe, which emptied separately in the caudal vena cava, was established. The other vein was a large-sized vein from the remainder of the central division, which frequently joined the common left hepatic vein from the left liver lobes. The common left hepatic vein was the largest of all the aforementioned hepatic veins.

  6. Warfarin improves the outcome of infrainguinal vein bypass grafting at high risk for failure.

    Science.gov (United States)

    Sarac, T P; Huber, T S; Back, M R; Ozaki, C K; Carlton, L M; Flynn, T C; Seeger, J M

    1998-09-01

    Patients with marginal venous conduit, poor arterial runoff, and prior failed bypass grafts are at high risk for infrainguinal graft occlusion and limb loss. We sought to evaluate the effects of anticoagulation therapy after autogenous vein infrainguinal revascularization on duration of patency, limb salvage rates, and complication rates in this subset of patients. This randomized prospective trial was performed in a university tertiary care hospital and in a Veterans Affairs Hospital. Fifty-six patients who were at high risk for graft failure were randomized to receive aspirin (24 patients, 27 bypass grafts) or aspirin and warfarin (WAR; 32 patients, 37 bypass grafts). All patients received 325 mg of aspirin each day, and the patients who were randomized to warfarin underwent anticoagulation therapy with heparin immediately after surgery and then were started on warfarin therapy to maintain an international normalized ratio between 2 and 3. Perioperative blood transfusions and complications were compared with the Student t test or with the chi2 test. Graft patency rates, limb salvage rates, and survival rates were compared with the Kaplan-Meier method and the log-rank test. Sixty-one of the 64 bypass grafts were performed for rest pain or tissue loss, and 3 were performed for short-distance claudication. There were no differences between the groups in ages, indications, bypass graft types, risk classifications (ie, conduit, runoff, or graft failure), or comorbid conditions (except diabetes mellitus). The cumulative 5-year survival rate was similar between the groups. The incidence rate of postoperative hematoma (32% vs 3.7%; P = .004) was greater in the WAR group, but no differences were seen between the WAR group and the aspirin group in the number of packed red blood cells transfused, in the incidence rate of overall nonhemorrhagic wound complications, or in the overall complication rate (62% vs 52%). The immediate postoperative primary graft patency rates (97

  7. Venous hemodynamic changes in lower limb venous disease

    DEFF Research Database (Denmark)

    Lee, Byung Boong; Nicolaides, Andrew N; Myers, Kenneth

    2016-01-01

    ). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various...... forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein thrombosis indicating their pathophysiological and clinical significance. Chapter 3 describes the hemodynamic...... changes that occur in different classes of chronic venous disease and their relation to the anatomic extent of disease in the macrocirculation and microcirculation. The next four chapters (Chapters 4-7) describe the hemodynamic changes resulting from treatment by compression using different materials...

  8. Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

    International Nuclear Information System (INIS)

    Currarino, G.; Stannard, M.W.; Texas Univ., Dallas, TX; Kolni, H.

    1991-01-01

    This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.)

  9. Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

    Energy Technology Data Exchange (ETDEWEB)

    Currarino, G.; Stannard, M.W. (Children' s Medical Center, Dallas, TX (United States). Dept. of Radiology Texas Univ., Dallas, TX (United States). Southwestern Medical Center); Kolni, H. (Methodist Hospital, Dallas, TX (United States). Dept. of Pediatrics)

    1991-05-01

    This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.).

  10. Catheter-directed thrombolysis for acute iliofemoral deep vein thrombosis via the ipsilateral great saphenous vein approach: a comparative clinical study

    International Nuclear Information System (INIS)

    Su Haobo; Gu Jianping; Lou Wensheng; He Xu; Chen Liang; Chen Guoping; Song Jinhua; Wang Tao

    2011-01-01

    Objective: To investigate prospectively the feasibility and clinical value of catheterization via the ipsilateral great saphenous vein in catheter-directed thrombolysis (CDT) for acute iliofemoral deep vein thrombosis (IFVT) by a comparative study. Methods: The prospective study included 93 cases of IFVT proved by venography. All patients were divided into three groups randomly. In group A, 31 patients received CDT via the ipsilateral great saphenous vein. In group B, 27 patients received CDT via the ipsilateral popliteal vein. In group C, 35 patients received anterograde thrombolysis via an ipsilateral dorsalis pedis vein. Urokinase was adopted as the thrombolytic agent in all cases. The assessment of the curative effect include therapeutic effective rate, rate of edema reduction and venous patency which were observed according to the clinical symptoms and the follow-up venograms obtained 5 days after thrombolysis. The time and comfort scores of procedures was recorded and compared between group A and B using two independent samples t test. The rate of edema reduction and venous patency were assessed using analysis of variance (LSD method). Therapeutic effective rate and complication rate were assessed using Chi-square test. Results: The total effective rate of the three groups were 90.3% (28/31), 92.6% (25/27) and 68.6% (24/35) respectively. The limbs edema reduction rate were (83.5±21.1)%, (82.4±20.1)%, and (67.0±23.3)% respectively (F= 6.059, P=0.003). The venous patency rate after thrombolysis were (61.2±20.2)%, (55.7±20.5)%, and (44.2±23.6)% respectively. There was no significant difference between group A and B in therapeutic effective rate (χ 2 =0.09, P=0.759), rate of edema reduction (P=0.822) and venous patency (P=0.343) . There was a significant difference statistically in therapeutic effective rate (χ 2 =4.65, P=0.031), rate of edema reduction (P=0.002) and venous patency (P=0.002) between group A and C. Compared with group A and B, the

  11. Invariant description of solutions of hydrodynamic-type systems in hodograph space: hydrodynamic surfaces

    International Nuclear Information System (INIS)

    Ferapontov, E.V.

    2002-01-01

    Hydrodynamic surfaces are solutions of hydrodynamic-type systems viewed as non-parametrized submanifolds of the hodograph space. We propose an invariant differential-geometric characterization of hydrodynamic surfaces by expressing the curvature form of the characteristic web in terms of the reciprocal invariants. (author)

  12. An introduction to relativistic hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Font, Jose A [Departamento de AstronomIa y AstrofIsica, Universidad de Valencia, Dr. Moliner 50, 46100 Burjassot (Valencia) (Spain)

    2007-11-15

    We review formulations of the equations of (inviscid) general relativistic hydrodynamics and (ideal) magnetohydrodynamics, along with methods for their numerical solution. Both systems can be cast as first-order, hyperbolic systems of conservation laws, following the explicit choice of an Eulerian observer and suitable fluid and magnetic field variables. During the last fifteen years, the so-called (upwind) high-resolution shock-capturing schemes based on Riemann solvers have been successfully extended from classical to relativistic fluid dynamics, both special and general. Nowadays, general relativistic hydrodynamical simulations in relativistic astrophysics are routinely performed, particularly within the test-fluid approximation but also for dynamical spacetimes. While such advances also hold true in the case of the MHD equations, the astrophysical applications investigated so far are still limited, yet the field is bound to witness major developments in the near future. The article also presents a brief overview of numerical techniques, providing state-of-the-art examples of their applicability to general relativistic fluids and magneto-fluids in characteristic scenarios of relativistic astrophysics.

  13. Inducer Hydrodynamic Load Measurement Devices

    Science.gov (United States)

    Skelley, Stephen E.; Zoladz, Thomas F.

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This "rotating balance" was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  14. CHASM Challenge Problem: Lagrangian Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, R [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keasler, J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gokhale, M [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-09-10

    Computer simulations of many science and engineering problems require modeling the equations of hydrodynamics which describe the motion of materials relative to each other induced by various forces. Many important DoD simulation problems involve complex multi-material systems that undergo large deformations. Examples include the analysis of armor defense, penetration mechanics, blast effects, structural integrity, and conventional munitions such as shaped charges and explosively formed projectiles. Indeed, the original motivation for developing codes that solve the equations of hydrodynamics, herein referred to as “hydrocodes”, was to solve problems with defense applications. The FY2010 Requirements Analysis Report issued by the DoD High Performance Computing Modernization Program (HPCMP) Office shows that a major portion of DoD HPC activities involves hydrocodes [HPCMP2010]. The report surveyed 496 projects across the Services and various Agencies, representing 4,050 HPCMP users at more than 125 locations, including government, contractors, and academia, and grouped each project into one of ten categories.

  15. Fluctuating hydrodynamics for ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lazaridis, Konstantinos [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States); Wickham, Logan [Department of Computer Science, Washington State University, Richland, 99354 (United States); Voulgarakis, Nikolaos, E-mail: n.voulgarakis@wsu.edu [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States)

    2017-04-25

    We present a mean-field fluctuating hydrodynamics (FHD) method for studying the structural and transport properties of ionic liquids in bulk and near electrified surfaces. The free energy of the system consists of two competing terms: (1) a Landau–Lifshitz functional that models the spontaneous separation of the ionic groups, and (2) the standard mean-field electrostatic interaction between the ions in the liquid. The numerical approach used to solve the resulting FHD-Poisson equations is very efficient and models thermal fluctuations with remarkable accuracy. Such density fluctuations are sufficiently strong to excite the experimentally observed spontaneous formation of liquid nano-domains. Statistical analysis of our simulations provides quantitative information about the properties of ionic liquids, such as the mixing quality, stability, and the size of the nano-domains. Our model, thus, can be adequately parameterized by directly comparing our prediction with experimental measurements and all-atom simulations. Conclusively, this work can serve as a practical mathematical tool for testing various theories and designing more efficient mixtures of ionic liquids. - Highlights: • A new fluctuating hydrodynamics method for ionic liquids. • Description of ionic liquid morphology in bulk and near electrified surfaces. • Direct comparison with experimental measurements.

  16. Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

    Science.gov (United States)

    Cui, Jian; McQuillan, Patrick M.; Blaha, Cheryl; Kunselman, Allen R.

    2012-01-01

    We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects. PMID:22707559

  17. Treatment of intimal sarcoma of peripheral veins

    Directory of Open Access Journals (Sweden)

    Javier López-Gómez

    2017-01-01

    Conclusion: We propose that given the aggressive behavior of these tumors, they should be treated with chemoradiotherapy postoperative, either by systemic chemotherapy or isolated limb perfusion for the limp sparing surgery in this histology.

  18. Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

    Science.gov (United States)

    Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B.

    2014-01-01

    62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. Conclusion The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival. PMID:25568802

  19. Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy - Case report.

    Science.gov (United States)

    Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B

    2014-12-01

    62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

  20. Hydrodynamic Overview at Hot Quarks 2016

    International Nuclear Information System (INIS)

    Noronha-Hostler, Jacquelyn

    2017-01-01

    Event-by-event relativistic hydrodynamics has been extremely successful in describing flow observables in heavy-ion collisions. However, the initial state and viscosity simultaneously affect comparisons to data so a discussion of experimental observables that help to distinguish the two follows. Specific problems that arise in the hydrodynamical modeling at the Beam Energy Scan are also addressed. (paper)

  1. Two-fluid hydrodynamic model for semiconductors

    DEFF Research Database (Denmark)

    Maack, Johan Rosenkrantz; Mortensen, N. Asger; Wubs, Martijn

    2018-01-01

    The hydrodynamic Drude model (HDM) has been successful in describing the optical properties of metallic nanostructures, but for semiconductors where several different kinds of charge carriers are present an extended theory is required. We present a two-fluid hydrodynamic model for semiconductors...

  2. 980-nm laser therapy versus varicose vein surgery in racially diverse Penang, Malaysia.

    Science.gov (United States)

    Lakhwani, Murli N; Dadlani, Navin I; Wong, Yong C

    2009-05-01

    Chronic venous disorders are conditions of increasing prevalence in the developing world, and venous ulceration is the terminal sequel. Currently there are only limited data on all aspects of this from Southeast Asia. The aim of the present study was to assess differences in the demography and outcome between varicose vein surgery (VVS) and the relatively new endovenous laser therapy (EVT) in patients from Penang, Malaysia. A retrospective study was performed. Patients who presented to the outpatient clinic of the surgical department with saphenofemoral junction and/or saphenopopliteal junction incompetence associated with reflux of the great saphenous vein or small saphenous vein, respectively, underwent either surgery (1999-2004) or laser therapy (2004-2006). A single surgeon at a single institution performed all procedures. A total of 350 limbs were treated from 292 patients. Demographics, symptoms, outcomes and complications that arose in both groups were compared. There were significant improvements in pains, swelling, cramps and heaviness postoperatively (P popular as an elective procedure with its minimally invasive nature, cosmesis, rapid recovery and other advantages. Surgery remains an important and very cost-effective procedure, especially in a developing society such as Penang.

  3. Hemolytic potential of hydrodynamic cavitation.

    Science.gov (United States)

    Chambers, S D; Bartlett, R H; Ceccio, S L

    2000-08-01

    The purpose of this study was to determine the hemolytic potentials of discrete bubble cavitation and attached cavitation. To generate controlled cavitation events, a venturigeometry hydrodynamic device, called a Cavitation Susceptibility Meter (CSM), was constructed. A comparison between the hemolytic potential of discrete bubble cavitation and attached cavitation was investigated with a single-pass flow apparatus and a recirculating flow apparatus, both utilizing the CSM. An analytical model, based on spherical bubble dynamics, was developed for predicting the hemolysis caused by discrete bubble cavitation. Experimentally, discrete bubble cavitation did not correlate with a measurable increase in plasma-free hemoglobin (PFHb), as predicted by the analytical model. However, attached cavitation did result in significant PFHb generation. The rate of PFHb generation scaled inversely with the Cavitation number at a constant flow rate, suggesting that the size of the attached cavity was the dominant hemolytic factor.

  4. Deterministic hydrodynamics: Taking blood apart

    Science.gov (United States)

    Davis, John A.; Inglis, David W.; Morton, Keith J.; Lawrence, David A.; Huang, Lotien R.; Chou, Stephen Y.; Sturm, James C.; Austin, Robert H.

    2006-10-01

    We show the fractionation of whole blood components and isolation of blood plasma with no dilution by using a continuous-flow deterministic array that separates blood components by their hydrodynamic size, independent of their mass. We use the technology we developed of deterministic arrays which separate white blood cells, red blood cells, and platelets from blood plasma at flow velocities of 1,000 μm/sec and volume rates up to 1 μl/min. We verified by flow cytometry that an array using focused injection removed 100% of the lymphocytes and monocytes from the main red blood cell and platelet stream. Using a second design, we demonstrated the separation of blood plasma from the blood cells (white, red, and platelets) with virtually no dilution of the plasma and no cellular contamination of the plasma. cells | plasma | separation | microfabrication

  5. The hydrodynamic theory of detonation

    Science.gov (United States)

    Langweiler, Heinz

    1939-01-01

    This report derives equations containing only directly measurable constants for the quantities involved in the hydrodynamic theory of detonation. The stable detonation speed, D, is revealed as having the lowest possible value in the case of positive material velocity, by finding the minimum of the Du curve (u denotes the speed of the gases of combustion). A study of the conditions of energy and impulse in freely suspended detonating systems leads to the disclosure of a rarefaction front traveling at a lower speed behind the detonation front; its velocity is computed. The latent energy of the explosive passes into the steadily growing detonation zone - the region between the detonation front and the rarefaction front. The conclusions lead to a new definition of the concept of shattering power. The calculations are based on the behavior of trinitrotoluene.

  6. Fluctuating nonlinear hydrodynamics of flocking

    Science.gov (United States)

    Yadav, Sunil Kumar; Das, Shankar P.

    2018-03-01

    Starting from a microscopic model, the continuum field theoretic description of the dynamics of a system of active ingredients or "particles" is presented. The equations of motion for the respective collective densities of mass and momentum follow exactly from that of a single element in the flock. The single-particle dynamics has noise and anomalous momentum dependence in its frictional terms. The equations for the collective densities are averaged over a local equilibrium distribution to obtain the corresponding coarse grained equations of fluctuating nonlinear hydrodynamics (FNH). The latter are the equations used frequently for describing active systems on the basis of intuitive arguments. The transport coefficients which appear in the macroscopic FNH equations are determined in terms of the parameters of the microscopic dynamics.

  7. Hydrodynamics and phases of flocks

    International Nuclear Information System (INIS)

    Toner, John; Tu Yuhai; Ramaswamy, Sriram

    2005-01-01

    We review the past decade's theoretical and experimental studies of flocking: the collective, coherent motion of large numbers of self-propelled 'particles' (usually, but not always, living organisms). Like equilibrium condensed matter systems, flocks exhibit distinct 'phases' which can be classified by their symmetries. Indeed, the phases that have been theoretically studied to date each have exactly the same symmetry as some equilibrium phase (e.g., ferromagnets, liquid crystals). This analogy with equilibrium phases of matter continues in that all flocks in the same phase, regardless of their constituents, have the same 'hydrodynamic'-that is, long-length scale and long-time behavior, just as, e.g., all equilibrium fluids are described by the Navier-Stokes equations. Flocks are nonetheless very different from equilibrium systems, due to the intrinsically nonequilibrium self-propulsion of the constituent 'organisms'. This difference between flocks and equilibrium systems is most dramatically manifested in the ability of the simplest phase of a flock, in which all the organisms are, on average moving in the same direction (we call this a 'ferromagnetic' flock; we also use the terms 'vector-ordered' and 'polar-ordered' for this situation) to exist even in two dimensions (i.e., creatures moving on a plane), in defiance of the well-known Mermin-Wagner theorem of equilibrium statistical mechanics, which states that a continuous symmetry (in this case, rotation invariance, or the ability of the flock to fly in any direction) can not be spontaneously broken in a two-dimensional system with only short-ranged interactions. The 'nematic' phase of flocks, in which all the creatures move preferentially, or are simply oriented preferentially, along the same axis, but with equal probability of moving in either direction, also differs dramatically from its equilibrium counterpart (in this case, nematic liquid crystals). Specifically, it shows enormous number fluctuations, which

  8. Anomalous hydrodynamics kicks neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Matthias, E-mail: mski@ua.edu [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 5C2 (Canada); Uhlemann, Christoph F. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Bleicher, Marcus [Frankfurt Institute for Advanced Studies, Goethe-Universität Frankfurt (Germany); Institut für Theoretische Physik, Goethe Universität Frankfurt (Germany); Schaffner-Bielich, Jürgen [Institut für Theoretische Physik, Goethe Universität Frankfurt (Germany)

    2016-09-10

    Observations show that, at the beginning of their existence, neutron stars are accelerated briskly to velocities of up to a thousand kilometers per second. We argue that this remarkable effect can be explained as a manifestation of quantum anomalies on astrophysical scales. To theoretically describe the early stage in the life of neutron stars we use hydrodynamics as a systematic effective-field-theory framework. Within this framework, anomalies of the Standard Model of particle physics as underlying microscopic theory imply the presence of a particular set of transport terms, whose form is completely fixed by theoretical consistency. The resulting chiral transport effects in proto-neutron stars enhance neutrino emission along the internal magnetic field, and the recoil can explain the order of magnitude of the observed kick velocities.

  9. Deep vein thrombosis: a clinical review

    Directory of Open Access Journals (Sweden)

    Kesieme EB

    2011-04-01

    Full Text Available Emeka Kesieme1, Chinenye Kesieme2, Nze Jebbin3, Eshiobo Irekpita1, Andrew Dongo11Department of Surgery, Irrua Specialist Teaching Hospital, Irrua, Nigeria; 2Department of Paediatrics, Irrua Specialist Teaching Hospital, Irrua, Nigeria; 3Department of Surgery, University of Port Harcourt Teaching Hospital, Port-Harcourt, NigeriaBackground: Deep vein thrombosis (DVT is the formation of blood clots (thrombi in the deep veins. It commonly affects the deep leg veins (such as the calf veins, femoral vein, or popliteal vein or the deep veins of the pelvis. It is a potentially dangerous condition that can lead to preventable morbidity and mortality.Aim: To present an update on the causes and management of DVT.Methods: A review of publications obtained from Medline search, medical libraries, and Google.Results: DVT affects 0.1% of persons per year. It is predominantly a disease of the elderly and has a slight male preponderance. The approach to making a diagnosis currently involves an algorithm combining pretest probability, D-dimer testing, and compression ultrasonography. This will guide further investigations if necessary. Prophylaxis is both mechanical and pharmacological. The goals of treatment are to prevent extension of thrombi, pulmonary embolism, recurrence of thrombi, and the development of complications such as pulmonary hypertension and post-thrombotic syndrome.Conclusion: DVT is a potentially dangerous condition with a myriad of risk factors. Prophylaxis is very important and can be mechanical and pharmacological. The mainstay of treatment is anticoagulant therapy. Low-molecular-weight heparin, unfractionated heparin, and vitamin K antagonists have been the treatment of choice. Currently anticoagulants specifically targeting components of the common pathway have been recommended for prophylaxis. These include fondaparinux, a selective indirect factor Xa inhibitor and the new oral selective direct thrombin inhibitors (dabigatran and selective

  10. Epidemiological study on varicose veins in Budapest.

    Science.gov (United States)

    Bihari, I; Tornoci, L; Bihari, P

    2012-03-01

    To analyse the prevalence and risk factors of varicose veins and chronic venous disease in Budapest. Data were collected using a questionnaire, as well as by performing physical and Doppler ultrasound examination of 566 adult inhabitants of Budapest and some neighbouring villages. The prevalence of lower-extremity varicose veins was 57.1% in the study population. Verified risk factors include advancing age, pregnancy, jobs requiring a lot of standing, blue-collar work and excess body weight. Neither female gender nor the use of oral contraceptives or hormone replacement therapy was identified as a contributing factor. Hungarian prevalence data and risk factors seem to be similar to other European countries.

  11. Superficial Vein Thrombophlebitis in a Football Athlete.

    Science.gov (United States)

    Schleich, Kevin T; Smoot, M Kyle

    2016-03-01

    A 22-year-old professional football player presented to a preparticipation physical examination with a 2-week history of left leg discomfort extending from the groin to the knee over the previous 2 weeks. He was found to have superficial vein thrombophlebitis (SVT) of the left great saphenous vein extending from the knee to within approximately 1.6 cm of the saphenofemoral junction. There is paucity in the literature regarding the management of SVT, particularly in actively training athletes. This case addresses the considerations of anticoagulation management for SVT as well as the unique challenge of managing anticoagulation therapy in an athlete that is actively training.

  12. Focal skin defect, limb anomalies and microphthalmia.

    NARCIS (Netherlands)

    Jackson, K.E.; Andersson, H.C.

    2004-01-01

    We describe two unrelated female patients with congenital single focal skin defects, unilateral microphthalmia and limb anomalies. Growth and psychomotor development were normal and no brain malformation was detected. Although eye and limb anomalies are commonly associated, clinical anophthalmia and

  13. An approach to the painful upper limb

    African Journals Online (AJOL)

    Pain in the upper limb is a common presenting complaint in the primary health care setting and the ... disruptions or pathological fracture, as opposed to ... and a neurological assessment of the lower limbs. This is in addition to a thorough.

  14. Fingernails Yield Clues to Limb Regeneration

    Science.gov (United States)

    ... it is involved in limb formation in mammalian embryonic development, as well as limb regeneration in amphibians. ... of the nail stem cells and the underlying layer of cells called the nail epithelium are left ...

  15. Hydrodynamic dispersion within porous biofilms

    KAUST Repository

    Davit, Y.

    2013-01-23

    Many microorganisms live within surface-associated consortia, termed biofilms, that can form intricate porous structures interspersed with a network of fluid channels. In such systems, transport phenomena, including flow and advection, regulate various aspects of cell behavior by controlling nutrient supply, evacuation of waste products, and permeation of antimicrobial agents. This study presents multiscale analysis of solute transport in these porous biofilms. We start our analysis with a channel-scale description of mass transport and use the method of volume averaging to derive a set of homogenized equations at the biofilm-scale in the case where the width of the channels is significantly smaller than the thickness of the biofilm. We show that solute transport may be described via two coupled partial differential equations or telegrapher\\'s equations for the averaged concentrations. These models are particularly relevant for chemicals, such as some antimicrobial agents, that penetrate cell clusters very slowly. In most cases, especially for nutrients, solute penetration is faster, and transport can be described via an advection-dispersion equation. In this simpler case, the effective diffusion is characterized by a second-order tensor whose components depend on (1) the topology of the channels\\' network; (2) the solute\\'s diffusion coefficients in the fluid and the cell clusters; (3) hydrodynamic dispersion effects; and (4) an additional dispersion term intrinsic to the two-phase configuration. Although solute transport in biofilms is commonly thought to be diffusion dominated, this analysis shows that hydrodynamic dispersion effects may significantly contribute to transport. © 2013 American Physical Society.

  16. Premier's imaging IR limb sounder

    Science.gov (United States)

    Kraft, Stefan; Bézy, Jean-Loup; Meynart, Roland; Langen, Jörg; Carnicero Dominguez, Bernardo; Bensi, Paolo; Silvestrin, Pierluigi

    2017-11-01

    The Imaging IR Limb Sounder (IRLS) is one of the two instruments planned on board of the candidate Earth Explorer Core Mission PREMIER. PREMIER stands for PRocess Exploration through Measurements of Infrared and Millimetre-wave Emitted Radiation. PREMIER went recently through the process of a feasibility study (Phase A) within the Earth Observation Envelope Program. Emerging from recent advanced instrument technologies IRLS shall, next to a millimetre-wave limb sounder (called STEAMR), explore the benefits of three-dimensional limb sounding with embedded cloud imaging capability. Such 3D imaging technology is expected to open a new era of limb sounding that will allow detailed studies of the link between atmospheric composition and climate, since it will map simultaneously fields of temperature and many trace gases in the mid/upper troposphere and stratosphere across a large vertical and horizontal field of view and with high vertical and horizontal resolution. PREMIER shall fly in a tandem formation looking backwards to METOP's swath and thereby improve meteorological and environmental analyses.

  17. Adolescent Neuroblastoma of Lower Limb

    Directory of Open Access Journals (Sweden)

    Rajeshwari K

    2013-04-01

    Full Text Available Neuroblastoma is an embryonic tumour of neural crest origin, commonly seen in children with upper abdomen involvement. Rarely neuroblastomas present in adolescents and adults involving lower limb. Histopathologically neuroblastoma of lower limb can be confused with other small round cell tumour especially with Ewing's sarcoma and rhabdomyosarcoma. A 16 year old male presented with 15x11cm swelling, pain and multiple discharging sinuses of right leg since 4 months. Routine haematological and biochemical analysis were within normal limits. Radiology of right leg showed large soft tissue swelling encompassing the pathological fracture of tibia and bowing of fibula. Fine needle aspiration of the swelling revealed malignant small round cell tumour. Histopathology revealed poorly differentiated neuroblastoma of lower limb. The immunohistochemistry of Synaptophysin and Chromogranin were positive and CD 99 was negative. Neuroblastoma diagnosed at unusual site with uncommon age has poor prognosis. Hence, one must keep in mind the differential diagnosis of neuroblastoma as one of the differential diagnosis in evaluating the soft tissue tumours of lower limb.

  18. Learning about Vertebrate Limb Development

    Science.gov (United States)

    Liang, Jennifer O.; Noll, Matthew; Olsen, Shayna

    2014-01-01

    We have developed an upper-level undergraduate laboratory exercise that enables students to replicate a key experiment in developmental biology. In this exercise, students have the opportunity to observe live chick embryos and stain the apical ectodermal ridge, a key tissue required for development of the vertebrate limb. Impressively, every…

  19. Endograft Limb Occlusion in EVAR

    DEFF Research Database (Denmark)

    Taudorf, M; Jensen, L P; Vogt, K C

    2014-01-01

    % at 3 years. Logistic regression showed that iliac artery tortuosity (DIS) (p = .001) and body mass index (p = .007) had a significant impact on graft patency. CONCLUSION: A tortuous vessel on the preoperative CTA is associated with an increased risk of limb occlusion after EVAR. Adjunctive stenting...

  20. Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

    Directory of Open Access Journals (Sweden)

    Young Ho Park

    2012-10-01

    Full Text Available On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger-vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger-vein recognition is advantageous in that it involves the use of inexpensive and small devices that are difficult to counterfeit. In general, finger-vein recognition systems capture images by using near infrared (NIR illumination in conjunction with a camera. However, such systems can face operational difficulties, since the scattering of light from the skin can make capturing a clear image difficult. To solve this problem, we proposed new image quality enhancement method that measures the direction and thickness of vein lines. This effort represents novel research in four respects. First, since vein lines are detected in input images based on eight directional profiles of a grey image instead of binarized images, the detection error owing to the non-uniform illumination of the finger area can be reduced. Second, our method adaptively determines a Gabor filter for the optimal direction and width on the basis of the estimated direction and thickness of a detected vein line. Third, by applying this optimized Gabor filter, a clear vein image can be obtained. Finally, the further processing of the morphological operation is applied in the Gabor filtered image and the resulting image is combined with the original one, through which finger-vein image of a higher quality is obtained. Experimental results from application of our proposed image enhancement method show that the equal error rate (EER of finger-vein recognition decreases to approximately 0.4% in the case of a local binary pattern-based recognition and to approximately 0.3% in the case of a wavelet transform

  1. Management of the multiple limb amputee.

    Science.gov (United States)

    Davidson, J H; Jones, L E; Cornet, J; Cittarelli, T

    2002-09-10

    Multiple limb amputations involving at least one upper extremity are very uncommon. The amputation of both an upper and lower limb is even more uncommon. Due to the rarity of these amputations therapists are uncertain regarding the most appropriate treatment methods. While the majority of the protocols used for single limb amputations are appropriate for these multiple limb amputees, there are differences. Loss of multiple limbs creates a problem of overheating for the individual. Loss of an arm and leg results in difficulty donning the prostheses and difficulty using crutches and parallel bars during mobilization. A review is given of 16 multiple limb amputees seen in our rehabilitation centre in the last 15 years. Return to work was seen in one third and was not related to the number of the amputations. A higher proportion of these multiple limb amputations occur through alcoholism or attempted suicide behaviour than occurs with either single upper limb amputations or lower limb amputations. This existing behaviour can create a management problem for the rehabilitation team during rehabilitation. Guidelines as to appropriate prosthetic and preprosthetic care are provided to assist the practitioner who has the acute and long term care of these patients. All multiple limb amputees should be referred to a specialized rehabilitation centre to discuss prosthetic options and long term rehabilitation requirements. This paper does not discuss bilateral lower limb amputations when not combined with an upper limb amputation.

  2. Hyperinnervation improves Xenopus laevis limb regeneration.

    Science.gov (United States)

    Mitogawa, Kazumasa; Makanae, Aki; Satoh, Akira

    2018-01-15

    Xenopus laevis (an anuran amphibian) shows limb regeneration ability between that of urodele amphibians and that of amniotes. Xenopus frogs can initiate limb regeneration but fail to form patterned limbs. Regenerated limbs mainly consist of cone-shaped cartilage without any joints or branches. These pattern defects are thought to be caused by loss of proper expressions of patterning-related genes. This study shows that hyperinnervation surgery resulted in the induction of a branching regenerate. The hyperinnervated blastema allows the identification and functional analysis of the molecules controlling this patterning of limb regeneration. This paper focuses on the nerve affects to improve Xenopus limb patterning ability during regeneration. The nerve molecules, which regulate limb patterning, were also investigated. Blastemas grown in a hyperinnervated forelimb upregulate limb patterning-related genes (shh, lmx1b, and hoxa13). Nerves projecting their axons to limbs express some growth factors (bmp7, fgf2, fgf8, and shh). Inputs of these factors to a blastema upregulated some limb patterning-related genes and resulted in changes in the cartilage patterns in the regenerates. These results indicate that additional nerve factors enhance Xenopus limb patterning-related gene expressions and limb regeneration ability, and that bmp, fgf, and shh are candidate nerve substitute factors. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. An unusual case: right proximal ureteral compression by the ovarian vein and distal ureteral compression by the external iliac vein

    Directory of Open Access Journals (Sweden)

    Halil Ibrahim Serin

    2015-12-01

    Full Text Available A 32-years old woman presented to the emergency room of Bozok University Research Hospital with right renal colic. Multidetector computed tomography (MDCT showed compression of the proximal ureter by the right ovarian vein and compression of the right distal ureter by the right external iliac vein. To the best of our knowledge, right proximal ureteral compression by the ovarian vein together with distal ureteral compression by the external iliac vein have not been reported in the literature. Ovarian vein and external iliac vein compression should be considered in patients presenting to the emergency room with renal colic or low back pain and a dilated collecting system.

  4. From fins to limbs to fins: limb evolution in fossil marine reptiles.

    Science.gov (United States)

    Caldwell, Michael W

    2002-10-15

    Limb osteology and ontogenetic patterns of limb ossification are reviewed for extinct lineages of aquatically adapted diapsid reptiles. Phylogenies including these fossil taxa show that paddle-like limbs were independently derived, and that the varied limb morphologies were produced by evolutionary modifications to different aspects of the limb skeleton. Ancient marine reptiles modify the limb by reducing the relative size of the epipodials, modifying the perichondral and periosteal surface of elements distal to the propodials, and evolving extremes of hyperphalangy and hyperdactyly. Developmental genetic models illuminate gene systems that may have controlled limb evolution in these animals. Copyright 2002 Wiley-Liss, Inc.

  5. Transcutaneous laser treatment of leg veins

    NARCIS (Netherlands)

    Meesters, Arne A.; Pitassi, Luiza H. U.; Campos, Valeria; Wolkerstorfer, Albert; Dierickx, Christine C.

    2014-01-01

    Leg telangiectasias and reticular veins are a common complaint affecting more than 80% of the population to some extent. To date, the gold standard remains sclerotherapy for most patients. However, there may be some specific situations, where sclerotherapy is contraindicated such as needle phobia,

  6. Puerperal ovarian vein thrombosis: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Sik; Jeon, Woo Ki; Han, Chang Yul [Inje College Paik Hospital, Pusan (Korea, Republic of)

    1989-08-15

    Puerperal ovarian vein thrombophlebitis(POVT) is a postpartum complication that requires prompt medical treatment to avoid extension of thrombus with potentially life-threatening complications. The prompt noninvasive diagnosing method is CT that defines the location and the extent about the thrombus. There findings will supply future case to be definitely diagnosed and treated without invasive procedures.

  7. Endovascular vein harvest: systemic carbon dioxide absorption.

    Science.gov (United States)

    Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

    2006-06-01

    Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

  8. What Are Varicose Veins? (For Kids)

    Science.gov (United States)

    ... Recipes for Kids Kids site Sitio para niños How the Body Works Puberty & Growing Up Staying Healthy Staying Safe Recipes & ... those body parts are farthest from the heart. Gravity pulls blood down into your ... down. So the veins have to work extra hard to get that blood back up ...

  9. THE INFLUENCE OF LOWER LIMB MOVEMENT ON UPPER LIMB MOVEMENT SYMMETRY WHILE SWIMMING THE BREASTSTROKE

    OpenAIRE

    M. Jaszczak

    2011-01-01

    This study 1) examined the influence of lower limb movement on upper limb movement symmetry, 2) determined the part of the propulsion phase displaying the greatest hand movement asymmetry, 3) diagnosed the range of upper limb propulsion phase which is the most prone to the influence of the lower limbs while swimming the breaststroke. Twenty-four participants took part in two tests. Half of them performed an asymmetrical leg movement. The propulsion in the first test was generated by four limb...

  10. Varicose Veins: Role of Mechanotransduction of Venous Hypertension

    Science.gov (United States)

    Atta, Hussein M.

    2012-01-01

    Varicose veins affect approximately one-third of the adult population and result in significant psychological, physical, and financial burden. Nevertheless, the molecular pathogenesis of varicose vein formation remains unidentified. Venous hypertension exerted on veins of the lower extremity is considered the principal factor in varicose vein formation. The role of mechanotransduction of the high venous pressure in the pathogenesis of varicose vein formation has not been adequately investigated despite a good progress in understanding the mechanomolecular mechanisms involved in transduction of high blood pressure in the arterial wall. Understanding the nature of the mechanical forces, the mechanosensors and mechanotransducers in the vein wall, and the downstream signaling pathways will provide new molecular targets for the prevention and treatment of varicose veins. This paper summarized the current understanding of mechano-molecular pathways involved in transduction of hemodynamic forces induced by blood pressure and tries to relate this information to setting of venous hypertension in varicose veins. PMID:22489273

  11. Incidental retroaortic left innominate vein in adult patient

    Directory of Open Access Journals (Sweden)

    Alexandre Semionov, MD, PhD

    2017-09-01

    Full Text Available Retro-aortic left innominate vein is a rare vascular abnormality, usually associated with congenital heart disease. Here we report a case of isolated retro-aortic left innominate vein in an adult female.

  12. Efficacy and safety of rotating pigtail catheter: lower extremity deep vein thrombosis of may-thurner syndrome

    International Nuclear Information System (INIS)

    Kim, Yoon Kyung; Kang, Byung Chul; Gang, Sung Gown

    2004-01-01

    The purpose of this study was to evaluate the efficacy and safety of mechanical fragmentation of iliofemoral deep vein thromboses (DVTs) with a rotating pigtail catheter followed by aspiration thrombectomy. Ten patients (eight females, two males, 56.8 +/- 21.37 years) with iliofemoral DVT underwent treatment for a total of ten affected limbs. Approximately 5-10 min after infusing 400,000-700,000 IU urokinase (UK) into the thrombosed deep veins, the thromboses were fragmented by the mechanical action of the rotating pigtail catheter tip. Following their fragmentation, the fragmented thromboses were aspirated. After completion of the above procedure, a stent was inserted if iliac vein stenosis was demonstrated. We evaluated the total procedure time, volume of thrombolytic agent (urokinase), valvular injury, symptom-free time interval and success rate (primary patency rate). In all 10 patients, the iliofemoral deep vein thrombosis was successfully fragmented and aspirated using the combination method of a rotating pigtail catheter and aspiration thrombectomy (clinical and technical success rate, 100%). The thromboses were declotted by means of a rotating pigtail catheter with an average treatment time of 5.7 minutes. The average duration of the total intervention was 108 min. The mean primary patency was approximately 4 months with no recurrence. The total UK dose was 890,000 IU on average. There were no major complications, such as pulmonary embolism or cerebral hemorrhage, while performing the thrombus-fragmentation procedure using the rotating pigtail catheter. The combination method of a rotating pigtail catheter and aspiration thrombectomy for the treatment of iliofemoral deep vein thrombosis was found to be rapid, safe and effective for accomplishing recanalization in all cases without complication. Therefore, this procedure constitutes a potential treatment option in patients presenting with iliofemoral vein thrombosis

  13. The clinical application of interventional therapy for lower limb deep venous thrombosis

    International Nuclear Information System (INIS)

    Tang Maoshun; Gao Wenhui; Chen Zhou; Zhang Ming; Qian Sheng

    2009-01-01

    Objective: To evaluate the clinical effect of comprehensive interventional treatment for lower extremity deep venous thrombosis. Methods: Comprehensive interventional therapy was performed in 33 patients with lower extremity deep venous thrombosis. The clinical data and the therapeutic results were retrospectively analyzed. Of 33 patients, placement of inferior vena cava filter with postoperative anticoagulant and thrombolytic therapy was employed in 10, while placing of inferior vena cava filter together with reopening of the affected-side iliac-femoral vein was carried out in 23. Results: During the follow-up period, no serious complications, such as massive hemorrhage and lethal pulmonary artery embolism, occurred. Complete dissolution of the thrombus in the lower extremity deep vein was obtained in 23 cases, and partial dissolution of the thrombus in 10 cases. Conclusion: Comprehensive interventional therapy is an effective,safe and feasible technique for the treatment of lower limb deep venous thrombosis. (authors)

  14. Surgical treatment for a complex congenital arteriovenous malformation of the lower limb.

    Science.gov (United States)

    Ozcan, Ali Vefa; Boysan, Emre; Isikli, Osman Yasar; Goksin, Ibrahim

    2013-01-01

    Arteriovenous fistula is defined as an abnormal communication between the arterial and venous systems. The complexity of congenital arteriovenous malformations makes treatment challenging. We present the case of a 23-year-old woman who had a complex congenital arteriovenous malformation in her left leg and a history of 2 unsuccessful coil-embolization procedures. We ligated all the feeding arteries of the arteriovenous malformation in the region of the superficial femoral artery, and the surgery was successful without sequelae. The patient returned 2 years later with thrombosis of the great saphenous vein and underwent a second operation. The thrombosed vein and all varicosities were excised successfully. Surgery can be an effective method for correcting complex congenital arteriovenous malformations, especially in the lower limbs. A 2-staged surgical approach like ours might be a good option in suitable patients.

  15. Relativistic conformal magneto-hydrodynamics from holography

    International Nuclear Information System (INIS)

    Buchbinder, Evgeny I.; Buchel, Alex

    2009-01-01

    We use the AdS/CFT correspondence to study first-order relativistic viscous magneto-hydrodynamics of (2+1)-dimensional conformal magnetic fluids. It is shown that the first order magneto-hydrodynamics constructed following Landau and Lifshitz from the positivity of the entropy production is inconsistent. We propose additional contributions to the entropy motivated dissipative current and, correspondingly, new dissipative transport coefficients. We use the strongly coupled M2-brane plasma in external magnetic field to show that the new magneto-hydrodynamics leads to self-consistent results in the shear and sound wave channels.

  16. Dileptons from transport and hydrodynamical models

    International Nuclear Information System (INIS)

    Huovinen, P.; Koch, V.

    2000-01-01

    Transport and hydrodynamical models used to describe the expansion stage of a heavy-ion collision at the CERN SPS give different dilepton spectrum even if they are tuned to reproduce the observed hadron spectra. To understand the origin of this difference we compare the dilepton emission from transport and hydrodynamical models using similar initial states in both models. We find that the requirement of pion number conservation in a hydrodynamical model does not change the dilepton emission. Also the mass distribution from the transport model indicates faster cooling and longer lifetime of the fireball

  17. Tuning bacterial hydrodynamics with magnetic fields

    Science.gov (United States)

    Pierce, C. J.; Mumper, E.; Brown, E. E.; Brangham, J. T.; Lower, B. H.; Lower, S. K.; Yang, F. Y.; Sooryakumar, R.

    2017-06-01

    Magnetotactic bacteria are a group of motile prokaryotes that synthesize chains of lipid-bound, magnetic nanoparticles called magnetosomes. This study exploits their innate magnetism to investigate previously unexplored facets of bacterial hydrodynamics at surfaces. Through use of weak, uniform, external magnetic fields and local, micromagnetic surface patterns, the relative strength of hydrodynamic, magnetic, and flagellar force components is tuned through magnetic control of the bacteria's orientation. The resulting swimming behaviors provide a means to experimentally determine hydrodynamic parameters and offer a high degree of control over large numbers of living microscopic entities. The implications of this controlled motion for studies of bacterial motility near surfaces and for micro- and nanotechnology are discussed.

  18. Limb development: a paradigm of gene regulation.

    Science.gov (United States)

    Petit, Florence; Sears, Karen E; Ahituv, Nadav

    2017-04-01

    The limb is a commonly used model system for developmental biology. Given the need for precise control of complex signalling pathways to achieve proper patterning, the limb is also becoming a model system for gene regulation studies. Recent developments in genomic technologies have enabled the genome-wide identification of regulatory elements that control limb development, yielding insights into the determination of limb morphology and forelimb versus hindlimb identity. The modulation of regulatory interactions - for example, through the modification of regulatory sequences or chromatin architecture - can lead to morphological evolution, acquired regeneration capacity or limb malformations in diverse species, including humans.

  19. Adventitial cystic disease of the common femoral vein presenting as deep vein thrombosis

    Directory of Open Access Journals (Sweden)

    Young-Kyun Kim

    2016-07-01

    Full Text Available Adventitial cystic disease of the common femoral vein is a rare condition. We herein report the case of a 50-year-old woman who presented with painless swelling in her left lower leg that resembled deep vein thrombosis. She underwent femoral exploration and excision of the cystic wall. The presentation, investigation, treatment, and pathology of this condition are discussed with a literature review.

  20. Vein visualization: patient characteristic factors and efficacy of a new infrared vein finder technology.

    Science.gov (United States)

    Chiao, F B; Resta-Flarer, F; Lesser, J; Ng, J; Ganz, A; Pino-Luey, D; Bennett, H; Perkins, C; Witek, B

    2013-06-01

    We investigated the patient characteristic factors that correlate with identification of i.v. cannulation sites with normal eyesight. We evaluated a new infrared vein finding (VF) technology device in identifying i.v. cannulation sites. Each subject underwent two observations: one using the conventional method (CM) of normal, unassisted eyesight and the other with the infrared VF device, VueTek's Veinsite™ (VF). A power analysis for moderate effect size (β=0.95) required 54 samples for within-subject differences. Patient characteristic profiles were obtained from 384 subjects (768 observations). Our sample population exhibited an overall average of 5.8 [95% confidence interval (CI) 5.4-6.2] veins using CM. As a whole, CM vein visualization were less effective among obese [4.5 (95% CI 3.8-5.3)], African-American [4.6 (95% CI 3.6-5.5 veins)], and Asian [5.1 (95% CI 4.1-6.0)] subjects. Next, the VF technology identified an average of 9.1 (95% CI 8.6-9.5) possible cannulation sites compared with CM [average of 5.8 (95% CI 5.4-6.2)]. Seventy-six obese subjects had an average of 4.5 (95% CI 3.8-5.3) and 8.2 (95% CI 7.4-9.1) veins viewable by CM and VF, respectively. In dark skin subjects, 9.1 (95% CI 8.3-9.9) veins were visible by VF compared with 5.4 (95% CI 4.8-6.0) with CM. African-American or Asian ethnicity, and obesity were associated with decreased vein visibility. The visibility of veins eligible for cannulation increased for all subgroups using a new infrared device.

  1. Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

    OpenAIRE

    Park, Young Ho; Park, Kang Ryoung

    2012-01-01

    On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger‐vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger‐vein recognition is advantageous in that it involves the use of inexpensive and small devices that are diffic...

  2. Palliative treatment of TIPS to portal vein tumor thrombosis complicated with portal vein hypertension

    International Nuclear Information System (INIS)

    Jiang Zaibo; Shan Hong; Guan Shouhai; Zhu Kangshun; Huang Mingsheng; Li Zhengran; Guo Tiansheng; Liu Lang

    2002-01-01

    Objective: To evaluate the palliative therapeutic effects of transjugular intrahepatic portosystemic shunt (TIPS) in portal vein tumor thrombosis (PVTT) complicated with portal vein hypertension, and to discuss the technical skills. Methods: There were 14 cases of end-stage hepatocellular carcinoma complicated with PVTT and portal vein hypertension, the average age was 53.6 yr. There were 8 cases with complete occlusion of main portal vein, 6 eases with incomplete thrombosis, and 5 cases combined with portal vein cavernous transformation. One case had simple hemorrhage, 3 eases had intractable ascites, and 10 cases had hemorrhage accompanied by intractable ascites. Results: The procedure of TIPS was successful in 10 cases, the successful rate was about 71%. The mean portal vein pressure was reduced from 37.2 mm Hg to 18.2 mm Hg, with an average reduction of 19.0 mm Hg. After the procedure of TIPS, the ascites decreased, hemorrhage stopped and the clinical symptoms disappeared. The average survival period was 132.3 days. The procedure were failing in 4 cases. Conclusion: TIPS was an effective palliative therapeutic methods to control the hemorrhage and ascites aroused by hepatic carcinoma complicated with PVTT

  3. Development and the evolvability of human limbs.

    Science.gov (United States)

    Young, Nathan M; Wagner, Günter P; Hallgrímsson, Benedikt

    2010-02-23

    The long legs and short arms of humans are distinctive for a primate, the result of selection acting in opposite directions on each limb at different points in our evolutionary history. This mosaic pattern challenges our understanding of the relationship of development and evolvability because limbs are serially homologous and genetic correlations should act as a significant constraint on their independent evolution. Here we test a developmental model of limb covariation in anthropoid primates and demonstrate that both humans and apes exhibit significantly reduced integration between limbs when compared to quadrupedal monkeys. This result indicates that fossil hominins likely escaped constraints on independent limb variation via reductions to genetic pleiotropy in an ape-like last common ancestor (LCA). This critical change in integration among hominoids, which is reflected in macroevolutionary differences in the disparity between limb lengths, facilitated selection for modern human limb proportions and demonstrates how development helps shape evolutionary change.

  4. Continuum limbed robots for locomotion

    Science.gov (United States)

    Mutlu, Alper

    This thesis focuses on continuum robots based on pneumatic muscle technology. We introduce a novel approach to use these muscles as limbs of lightweight legged robots. The flexibility of the continuum legs of these robots offers the potential to perform some duties that are not possible with classical rigid-link robots. Potential applications are as space robots in low gravity, and as cave explorer robots. The thesis covers the fabrication process of continuum pneumatic muscles and limbs. It also provides some new experimental data on this technology. Afterwards, the designs of two different novel continuum robots - one tripod, one quadruped - are introduced. Experimental data from tests using the robots is provided. The experimental results are the first published example of locomotion with tripod and quadruped continuum legged robots. Finally, discussion of the results and how far this technology can go forward is presented.

  5. Conformal invariance in hydrodynamic turbulence

    International Nuclear Information System (INIS)

    Falkovich, Gregory

    2007-01-01

    This short survey is written by a physicist. It contains neither theorems nor precise definitions. Its main content is a description of the results of numerical solution of the equations of fluid mechanics in the regime of developed turbulence. Due to limitations of computers, the results are not very precise. Despite being neither exact nor rigorous, the findings may nevertheless be of interest for mathematicians. The main result is that the isolines of some scalar fields (vorticity, temperature) in two-dimensional turbulence belong to the class of conformally invariant curves called SLE (Scramm-Loewner evolution) curves. First, this enables one to predict and find a plethora of quantitative relations going far beyond what was known previously about turbulence. Second, it suggests relations between phenomena that seemed unrelated, like the Euler equation and critical percolation. Third, it shows that one is able to get exact analytic results in statistical hydrodynamics. In short, physicists have found something unexpected and hope that mathematicians can help to explain it.

  6. The hydrodynamics of swimming microorganisms

    International Nuclear Information System (INIS)

    Lauga, Eric; Powers, Thomas R

    2009-01-01

    Cell motility in viscous fluids is ubiquitous and affects many biological processes, including reproduction, infection and the marine life ecosystem. Here we review the biophysical and mechanical principles of locomotion at the small scales relevant to cell swimming, tens of micrometers and below. At this scale, inertia is unimportant and the Reynolds number is small. Our emphasis is on the simple physical picture and fundamental flow physics phenomena in this regime. We first give a brief overview of the mechanisms for swimming motility, and of the basic properties of flows at low Reynolds number, paying special attention to aspects most relevant for swimming such as resistance matrices for solid bodies, flow singularities and kinematic requirements for net translation. Then we review classical theoretical work on cell motility, in particular early calculations of swimming kinematics with prescribed stroke and the application of resistive force theory and slender-body theory to flagellar locomotion. After examining the physical means by which flagella are actuated, we outline areas of active research, including hydrodynamic interactions, biological locomotion in complex fluids, the design of small-scale artificial swimmers and the optimization of locomotion strategies.

  7. Brachial Artery Aneurysm as a Limb Threatening Condition: a Case Report

    Directory of Open Access Journals (Sweden)

    Farhad Heydari

    2015-05-01

    Full Text Available Brachial artery aneurysms are rare but potentially limb threatening condition. The presented case here is a 52-year old male referred to the emergency department complaining a sudden onset and progressive pain with coldness of his right upper extremity during brushing. The right upper extremity was pulseless and three-dimensional computed tomography showed an aneurysm of the proximal right brachial artery associated with arterial occlusion in its distal branch. Embolectomy was done, the aneurysm resected, and the artery successfully re-vascularised by interposing a saphenous vein graft. 

  8. Framing Camera Improvements and hydrodynamic Experiments

    National Research Council Canada - National Science Library

    Drake, R. P

    2007-01-01

    .... We also propose to participate in hydrodynamic experiments at NRL whenever they occur, to prepare for an experiment for NIKE to study the onset of turbulence via the Kelvin Helmholtz instability...

  9. Hydrodynamic limit of interacting particle systems

    International Nuclear Information System (INIS)

    Landim, C.

    2004-01-01

    We present in these notes two methods to derive the hydrodynamic equation of conservative interacting particle systems. The intention is to present the main ideas in the simplest possible context and refer for details and references. (author)

  10. Hydrodynamic approach to electronic transport in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Narozhny, Boris N. [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Gornyi, Igor V. [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe (Germany); Ioffe Physical Technical Institute, St. Petersburg (Russian Federation); Mirlin, Alexander D. [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe (Germany); Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Schmalian, Joerg [Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute for Solid State Physics, Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2017-11-15

    The last few years have seen an explosion of interest in hydrodynamic effects in interacting electron systems in ultra-pure materials. In this paper we briefly review the recent advances, both theoretical and experimental, in the hydrodynamic approach to electronic transport in graphene, focusing on viscous phenomena, Coulomb drag, non-local transport measurements, and possibilities for observing nonlinear effects. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Improvements to SOIL: An Eulerian hydrodynamics code

    International Nuclear Information System (INIS)

    Davis, C.G.

    1988-04-01

    Possible improvements to SOIL, an Eulerian hydrodynamics code that can do coupled radiation diffusion and strength of materials, are presented in this report. Our research is based on the inspection of other Eulerian codes and theoretical reports on hydrodynamics. Several conclusions from the present study suggest that some improvements are in order, such as second-order advection, adaptive meshes, and speedup of the code by vectorization and/or multitasking. 29 refs., 2 figs

  12. Relabeling symmetries in hydrodynamics and magnetohydrodynamics

    International Nuclear Information System (INIS)

    Padhye, N.; Morrison, P.J.

    1996-04-01

    Lagrangian symmetries and concomitant generalized Bianchi identities associated with the relabeling of fluid elements are found for hydrodynamics and magnetohydrodynamics (MHD). In hydrodynamics relabeling results in Ertel's theorem of conservation of potential vorticity, while in MHD it yields the conservation of cross helicity. The symmetries of the reduction from Lagrangian (material) to Eulerian variables are used to construct the Casimir invariants of the Hamiltonian formalism

  13. Standardized Approach to Quantitatively Measure Residual Limb Skin Health in Individuals with Lower Limb Amputation.

    Science.gov (United States)

    Rink, Cameron L; Wernke, Matthew M; Powell, Heather M; Tornero, Mark; Gnyawali, Surya C; Schroeder, Ryan M; Kim, Jayne Y; Denune, Jeffrey A; Albury, Alexander W; Gordillo, Gayle M; Colvin, James M; Sen, Chandan K

    2017-07-01

    Objective: (1) Develop a standardized approach to quantitatively measure residual limb skin health. (2) Report reference residual limb skin health values in people with transtibial and transfemoral amputation. Approach: Residual limb health outcomes in individuals with transtibial ( n  = 5) and transfemoral ( n  = 5) amputation were compared to able-limb controls ( n  = 4) using noninvasive imaging (hyperspectral imaging and laser speckle flowmetry) and probe-based approaches (laser doppler flowmetry, transcutaneous oxygen, transepidermal water loss, surface electrical capacitance). Results: A standardized methodology that employs noninvasive imaging and probe-based approaches to measure residual limb skin health are described. Compared to able-limb controls, individuals with transtibial and transfemoral amputation have significantly lower transcutaneous oxygen tension, higher transepidermal water loss, and higher surface electrical capacitance in the residual limb. Innovation: Residual limb health as a critical component of prosthesis rehabilitation for individuals with lower limb amputation is understudied in part due to a lack of clinical measures. Here, we present a standardized approach to measure residual limb health in people with transtibial and transfemoral amputation. Conclusion: Technology advances in noninvasive imaging and probe-based measures are leveraged to develop a standardized approach to quantitatively measure residual limb health in individuals with lower limb loss. Compared to able-limb controls, resting residual limb physiology in people that have had transfemoral or transtibial amputation is characterized by lower transcutaneous oxygen tension and poorer skin barrier function.

  14. Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

    Directory of Open Access Journals (Sweden)

    Jianlin Tang

    2014-12-01

    Conclusion: The lessons we learned are (1 Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2 Synthetic graft is an alternative for internal jugular vein graft. (3 Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4 It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

  15. Early regulation of axolotl limb regeneration.

    Science.gov (United States)

    Makanae, Aki; Satoh, Akira

    2012-10-01

    Amphibian limb regeneration has been studied for a long time. In amphibian limb regeneration, an undifferentiated blastema is formed around the region damaged by amputation. The induction process of blastema formation has remained largely unknown because it is difficult to study the induction of limb regeneration. The recently developed accessory limb model (ALM) allows the investigation of limb induction and reveals early events of amphibian limb regeneration. The interaction between nerves and wound epidermis/epithelium is an important aspect of limb regeneration. During early limb regeneration, neurotrophic factors act on wound epithelium, leading to development of a functional epidermis/epithelium called the apical epithelial cap (AEC). AEC and nerves create a specific environment that inhibits wound healing and induces regeneration through blastema formation. It is suggested that FGF-signaling and MMP activities participate in creating a regenerative environment. To understand why urodele amphibians can create such a regenerative environment and humans cannot, it is necessary to identify the similarities and differences between regenerative and nonregenerative animals. Here we focus on ALM to consider limb regeneration from a new perspective and we also reported that focal adhesion kinase (FAK)-Src signaling controlled fibroblasts migration in axolotl limb regeneration. Copyright © 2012 Wiley Periodicals, Inc.

  16. Varicose Vein Stripping Under Low-Dose Spinal Anaesthesia

    Directory of Open Access Journals (Sweden)

    Nalan Muhammedoğlu

    2014-03-01

    Full Text Available Aim: Spinal anesthesia is frequently used for procedures involving the lower limbs. Compared with general anesthesia, low-dose spinal anesthesia is a cost-effective method and has advantages such as avoiding hypotension, longer duration of anesthesia and increased length of hospitalization. The aim of this trial was to compare two different low-dose bupivacaine drug regimens. Methods: Sixty unpremedicated patients were randomly allocated into two groups (n=30. There were no differences between the groups in age, weight, the American Society of Anesthesiologists (ASA physical status classification, gender, and duration of surgery. We performed spinal anesthesia at the L3-4 interspace with the patient in the lateral decubitus position. We administered 6.5 mg (group 1 and 8 mg (group 2 0.5% heavy bupivacaine into the subarachnoid space. We positioned the patient laterally to the operation side for 15 minutes, then, turned to supine position. Motor and sensory block was assessed by the Bromage scale and pinprick test. Results: There were significant differences between the two groups in duration of motor block, but no significant differences in hemodynamic response to spinal anesthesia. None of the patients had intraoperative pain. Five patients in group 1 and 2 patients in group 2 had urinary retention. Conclusion: Our observations suggest that 6.5 mg heavy bupivacaine is efficient and suitable for unilateral varicose veins stripping operation. (The Me­di­cal Bul­le­tin of Ha­se­ki 2014; 52: 25-8

  17. Lower extremity dep vein thrombosis in children

    International Nuclear Information System (INIS)

    Perlmutt, L.; Fellows, K.E.; Harvard Medical School, Boston, MA

    1983-01-01

    Of 113 leg venograms performed in patients of all ages between 1969 and 1982, 68 were in children 16 years old or less. The patients were all studied on a tilt table (method of Rabinov and Paulin) in a head-up, 40-50 0 incline without tourniquets, supporting their weight on the unaffected leg. Among the 68 venograms, 12 (18%) were positive for deep vein thrombosis. The clinical settings for thrombosis in children were post-catheterization (two patients), post surgery (two), tumor/tumor therapy (three), drug abuse (one), and idiopathic (three). There were no long-term clinical sequelae in five patients. Pulmonary infarction occurred in three, and three patients required either long-term anticoagulation or IVC clipping. Clinical diagnosis is no more accurate for the diagnosis of deep vein thrombosis in children than it is in adults. Venography is the best method for making an accurate diagnosis and directing subsequent therapy.(orig.)

  18. Varicose vein therapy and nerve lesions.

    Science.gov (United States)

    Hirsch, Tobias

    2017-03-01

    Treating varicose veins using endovenous thermal techniques - especially laser and radio frequency ablation - has emerged as an effective alternative to open surgery with stripping and high ligation. Even though these methods are very gentle and patient-friendly, they are nevertheless accompanied by risks and side effects. Compared to open surgical therapy, the risk of damage to peripheral and motor nerves is reduced; however, it still exists as a result of heat exposure and tumescent anaesthesia. Non-thermal methods that can be applied without tumescent anaesthesia have been introduced to the market. They pose a considerably lower risk of nerve lesions while proving to be much more effective. This paper investigates data on postoperative nerve damage and paraesthesia using internet research (PubMed). It analyses the current state of knowledge regarding non-thermal treatment methods and takes into account the latest developments in the use of cyanoacrylate to close insufficient saphenous veins.

  19. Finger vein recognition with personalized feature selection.

    Science.gov (United States)

    Xi, Xiaoming; Yang, Gongping; Yin, Yilong; Meng, Xianjing

    2013-08-22

    Finger veins are a promising biometric pattern for personalized identification in terms of their advantages over existing biometrics. Based on the spatial pyramid representation and the combination of more effective information such as gray, texture and shape, this paper proposes a simple but powerful feature, called Pyramid Histograms of Gray, Texture and Orientation Gradients (PHGTOG). For a finger vein image, PHGTOG can reflect the global spatial layout and local details of gray, texture and shape. To further improve the recognition performance and reduce the computational complexity, we select a personalized subset of features from PHGTOG for each subject by using the sparse weight vector, which is trained by using LASSO and called PFS-PHGTOG. We conduct extensive experiments to demonstrate the promise of the PHGTOG and PFS-PHGTOG, experimental results on our databases show that PHGTOG outperforms the other existing features. Moreover, PFS-PHGTOG can further boost the performance in comparison with PHGTOG.

  20. Finger Vein Recognition with Personalized Feature Selection

    Directory of Open Access Journals (Sweden)

    Xianjing Meng

    2013-08-01

    Full Text Available Finger veins are a promising biometric pattern for personalized identification in terms of their advantages over existing biometrics. Based on the spatial pyramid representation and the combination of more effective information such as gray, texture and shape, this paper proposes a simple but powerful feature, called Pyramid Histograms of Gray, Texture and Orientation Gradients (PHGTOG. For a finger vein image, PHGTOG can reflect the global spatial layout and local details of gray, texture and shape. To further improve the recognition performance and reduce the computational complexity, we select a personalized subset of features from PHGTOG for each subject by using the sparse weight vector, which is trained by using LASSO and called PFS-PHGTOG. We conduct extensive experiments to demonstrate the promise of the PHGTOG and PFS-PHGTOG, experimental results on our databases show that PHGTOG outperforms the other existing features. Moreover, PFS-PHGTOG can further boost the performance in comparison with PHGTOG.

  1. Chaotic hydrodynamics of fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Van der Stappen, M.L.M. [Unit Process and Systems Engineering, Advanced Manufacturing Technology Group, Unilever Research Laboratorium, Vlaardingen (Netherlands)

    1996-12-31

    The major goals of this thesis are: (1) to develop and evaluate an analysis method based on techniques from non-linear chaos theory to characterize the nonlinear hydrodynamics of gas-solids fluidized beds quantitatively; and (2) to determine the dependence of the chaotic invariants on the operating conditions and investigate how the chaos analysis method can be profitably applied to improve scale-up and design of gas-solids fluidized bed reactors. Chaos theory is introduced in chapter 2 with emphasis on analysis techniques for (experimental) time series, known from literature at the start of this work (1990-1991). In chapter 3, the testing of existing and newly developed techniques on both model and fluidized bed data is described. This leads to the development of the chaos analysis method to analyze measured pressure fluctuations time series of a fluidized bed. Following, in chapter 4, this method is tested and all choices for the parameters are evaluated. The influence of the experimental parameters and external disturbances on the measurements and analysis results is discussed and quantified. The result is a chaos measurement and analysis protocol, which is further used in this work. In chapter 5, the applications to fluidized beds are discussed. It is shown that the entropy is a good measure for the characterization of the dynamical behavior of gas-solids bubbling/slugging fluidized beds. Entropy is applied to characterize the influence of the operating conditions, to assess regime transitions and to analyze dimensionless similar beds of different scale. Quantitative design correlations that relate entropy to the operating parameters (including the bed diameter) are described. Finally, it is discussed how the results of this work might be used in scaling up the chaotic dynamics of fluidized beds. The overall conclusions and outlook from this work are presented in chapter 6. 182 refs.

  2. Hydrodynamics of soft active matter

    Science.gov (United States)

    Marchetti, M. C.; Joanny, J. F.; Ramaswamy, S.; Liverpool, T. B.; Prost, J.; Rao, Madan; Simha, R. Aditi

    2013-07-01

    This review summarizes theoretical progress in the field of active matter, placing it in the context of recent experiments. This approach offers a unified framework for the mechanical and statistical properties of living matter: biofilaments and molecular motors in vitro or in vivo, collections of motile microorganisms, animal flocks, and chemical or mechanical imitations. A major goal of this review is to integrate several approaches proposed in the literature, from semimicroscopic to phenomenological. In particular, first considered are “dry” systems, defined as those where momentum is not conserved due to friction with a substrate or an embedding porous medium. The differences and similarities between two types of orientationally ordered states, the nematic and the polar, are clarified. Next, the active hydrodynamics of suspensions or “wet” systems is discussed and the relation with and difference from the dry case, as well as various large-scale instabilities of these nonequilibrium states of matter, are highlighted. Further highlighted are various large-scale instabilities of these nonequilibrium states of matter. Various semimicroscopic derivations of the continuum theory are discussed and connected, highlighting the unifying and generic nature of the continuum model. Throughout the review, the experimental relevance of these theories for describing bacterial swarms and suspensions, the cytoskeleton of living cells, and vibrated granular material is discussed. Promising extensions toward greater realism in specific contexts from cell biology to animal behavior are suggested, and remarks are given on some exotic active-matter analogs. Last, the outlook for a quantitative understanding of active matter, through the interplay of detailed theory with controlled experiments on simplified systems, with living or artificial constituents, is summarized.

  3. Augmented reality based real-time subcutaneous vein imaging system.

    Science.gov (United States)

    Ai, Danni; Yang, Jian; Fan, Jingfan; Zhao, Yitian; Song, Xianzheng; Shen, Jianbing; Shao, Ling; Wang, Yongtian

    2016-07-01

    A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. Vein structures captured by the two cameras are matched and reconstructed based on the epipolar constraint and homographic property. The skin surface is reconstructed by active structured light with spatial encoding values and fusion displayed with the reconstructed vein. The vein and skin surface are both reconstructed in the 3D space. Results show that the structures can be precisely back-projected to the back of the hand for further augmented display and visualization. The overall system performance is evaluated in terms of vein segmentation, accuracy of vein matching, feature points distance error, duration times, accuracy of skin reconstruction, and augmented display. All experiments are validated with sets of real vein data. The imaging and augmented system produces good imaging and augmented reality results with high speed.

  4. Finger vein extraction using gradient normalization and principal curvature

    Science.gov (United States)

    Choi, Joon Hwan; Song, Wonseok; Kim, Taejeong; Lee, Seung-Rae; Kim, Hee Chan

    2009-02-01

    Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging. It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared images is the most difficult part in finger vein authentication. Uneven illumination, varying tissues and bones, and changes in the physical conditions and the blood flow make the thickness and brightness of the same vein different in each acquisition. Accordingly, extracting finger veins at their accurate positions regardless of their thickness and brightness is necessary for accurate personal identification. For this purpose, we propose a new finger vein extraction method which is composed of gradient normalization, principal curvature calculation, and binarization. As local brightness variation has little effect on the curvature and as gradient normalization makes the curvature fairly uniform at vein pixels, our method effectively extracts finger vein patterns regardless of the vein thickness or brightness. In our experiment, the proposed method showed notable improvement as compared with the existing methods.

  5. Brucellosis associated with deep vein thrombosis.

    Science.gov (United States)

    Tolaj, Ilir; Mehmeti, Murat; Ramadani, Hamdi; Tolaj, Jasmina; Dedushi, Kreshnike; Fejza, Hajrullah

    2014-11-19

    Over the past 10 years more than 700 cases of brucellosis have been reported in Kosovo, which is heavily oriented towards agriculture and animal husbandry. Here, brucellosis is still endemic and represents an uncontrolled public health problem. Human brucellosis may present with a broad spectrum of clinical manifestations; among them, vascular complications are uncommon. Hereby we describe the case of a 37-year-old male patient with brucellosis complicated by deep vein thrombosis on his left leg.

  6. Angiographic investigation of the male gonadal vein

    International Nuclear Information System (INIS)

    Vajda, J.; Boehm, K.; Horvath, L.; Molnar, Z.

    1980-01-01

    Retrograde angiography of the gonadal vein was carried out in 110 cases. Because of valve-insufficience the left vena spermatica interna filled spontaneously from the vena renalis in the majority (88%) of the cases. In the cases of well functioning valves superselective angiography was carried out. The examination is advised in cases of the following syndromes: varicokele, abdominal tumours, determination of the place of non-palpable testes, Klinefelter syndrome. (L.E.)

  7. Deep vein thrombosis: diagnosis, treatment, and prevention

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, W.P.; Youngswick, F.D.

    Deep vein thrombosis (DVT) is a dangerous complication that may present after elective foot surgery. Because of the frequency with which DVT occurs in the elderly patient, as well as in the podiatric surgical population, the podiatrist should be acquainted with this entity. A review of the diagnosis, treatment, prevention, and the role of podiatry in the management of DVT is discussed in this paper.

  8. Brucellosis associated with deep vein thrombosis

    Directory of Open Access Journals (Sweden)

    Ilir Tolaj

    2014-11-01

    Full Text Available Over the past 10 years more than 700 cases of brucellosis have been reported in Kosovo, which is heavily oriented towards agriculture and animal husbandry. Here, brucellosis is still endemic and represents an uncontrolled public health problem. Human brucellosis may present with a broad spectrum of clinical manifestations; among them, vascular complications are uncommon. Hereby we describe the case of a 37-year-old male patient with brucellosis complicated by deep vein thrombosis on his left leg.

  9. Brucellosis Associated with Deep Vein Thrombosis

    Science.gov (United States)

    Tolaj, Ilir; Mehmeti, Murat; Ramadani, Hamdi; Tolaj, Jasmina; Dedushi, Kreshnike; Fejza, Hajrullah

    2014-01-01

    Over the past 10 years more than 700 cases of brucellosis have been reported in Kosovo, which is heavily oriented towards agriculture and animal husbandry. Here, brucellosis is still endemic and represents an uncontrolled public health problem. Human brucellosis may present with a broad spectrum of clinical manifestations; among them, vascular complications are uncommon. Hereby we describe the case of a 37-year-old male patient with brucellosis complicated by deep vein thrombosis on his left leg. PMID:25568754

  10. Brucellosis Associated with Deep Vein Thrombosis

    OpenAIRE

    Tolaj, Ilir; Mehmeti, Murat; Ramadani, Hamdi; Tolaj, Jasmina; Dedushi, Kreshnike; Fejza, Hajrullah

    2014-01-01

    Over the past 10 years more than 700 cases of brucellosis have been reported in Kosovo, which is heavily oriented towards agriculture and animal husbandry. Here, brucellosis is still endemic and represents an uncontrolled public health problem. Human brucellosis may present with a broad spectrum of clinical manifestations; among them, vascular complications are uncommon. Hereby we describe the case of a 37-year-old male patient with brucellosis complicated by deep vein thrombosis on his left ...

  11. Absent right superior caval vein in situs solitus

    DEFF Research Database (Denmark)

    Lytzen, Rebekka; Sundberg, Karin; Vejlstrup, Niels

    2015-01-01

    Introduction In up to 0.07% of the general population, the right anterior cardinal vein obliterates and the left remains open, creating an absent right superior caval vein and a persistent left superior caval vein. Absent right superior caval vein is associated with additional congenital heart...... disease in about half the patients. We wished to study the consequences of absent right superior caval vein as an incidental finding on prenatal ultrasonic malformation screening. Material and methods This is a retrospective case series study of all foetuses diagnosed with absent right superior caval vein...... no postnatal complications. All children were found to have healthy hearts at follow-up. CONCLUSIONS: In all cases, the findings proved to be a benign condition with no clinical manifestations or complications. Although isolated absent right superior caval vein does not seem to affect the outcome, associated...

  12. Laser photocoagulation for retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    K. A. Mirzabekova

    2015-03-01

    Full Text Available Retinal vein occlusion (RVO is one of the leading causes of permanent vision loss. In adults, central retinal vein occlusion (CRVO occurs in 1.8% while branch retinal vein occlusion (BRVO occurs in 0.2%. Treatment strategy and disease prognosis are determined by RVO type (ischemic/non-ischemic. Despite numerous studies and many current CRVO and BRVO treatment approaches, the management of these patients is still being debated. Intravitreal injections of steroids (triamcinolone acetate, dexamethasone and vascular endothelial growth factor (VEGF inhibitors (bevacizumab, ranibizumab were shown to be fairly effective. However, it is unclear whether anti-VEGF agents are reasonable in ischemic RVOs. Laser photocoagulation remains the only effective treatment of optic nerve head and/or retinal neovascularization. Laser photocoagulation is also indicated for the treatment of macular edema. Both threshold and sub-threshold photocoagulation may be performed. Photocoagulation performed with argon (514 nm, krypton (647 nm, or diode (810 nm laser for macular edema provides similar results (no significant differences. The treatment may be complex and include medication therapy and/or surgery. Medication therapy includes anti-aggregant agents and antioxidants, i.e., emoxypine which may be used in acute RVO as well as in post-thrombotic retinopathy. 

  13. Compressed sensing approach for wrist vein biometrics.

    Science.gov (United States)

    Lantsov, Aleksey; Ryabko, Maxim; Shchekin, Aleksey

    2018-04-01

    The work describes features of the compressed sensing (CS) approach utilized for development of a wearable system for wrist vein recognition with single-pixel detection; we consider this system useful for biometrics authentication purposes. The CS approach implies use of a spatial light modulation (SLM) which, in our case, can be performed differently-with a liquid crystal display or diffusely scattering medium. We show that compressed sensing combined with above-mentioned means of SLM allows us to avoid using an optical system-a limiting factor for wearable devices. The trade-off between the 2 different SLM approaches regarding issues of practical implementation of CS approach for wrist vein recognition purposes is discussed. A possible solution of a misalignment problem-a typical issue for imaging systems based upon 2D arrays of photodiodes-is also proposed. Proposed design of the wearable device for wrist vein recognition is based upon single-pixel detection. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Laser photocoagulation for retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    K. A. Mirzabekova

    2015-01-01

    Full Text Available Retinal vein occlusion (RVO is one of the leading causes of permanent vision loss. In adults, central retinal vein occlusion (CRVO occurs in 1.8% while branch retinal vein occlusion (BRVO occurs in 0.2%. Treatment strategy and disease prognosis are determined by RVO type (ischemic/non-ischemic. Despite numerous studies and many current CRVO and BRVO treatment approaches, the management of these patients is still being debated. Intravitreal injections of steroids (triamcinolone acetate, dexamethasone and vascular endothelial growth factor (VEGF inhibitors (bevacizumab, ranibizumab were shown to be fairly effective. However, it is unclear whether anti-VEGF agents are reasonable in ischemic RVOs. Laser photocoagulation remains the only effective treatment of optic nerve head and/or retinal neovascularization. Laser photocoagulation is also indicated for the treatment of macular edema. Both threshold and sub-threshold photocoagulation may be performed. Photocoagulation performed with argon (514 nm, krypton (647 nm, or diode (810 nm laser for macular edema provides similar results (no significant differences. The treatment may be complex and include medication therapy and/or surgery. Medication therapy includes anti-aggregant agents and antioxidants, i.e., emoxypine which may be used in acute RVO as well as in post-thrombotic retinopathy. 

  15. Metabolic effects of portal vein sensing.

    Science.gov (United States)

    Mithieux, G

    2014-09-01

    The extrinsic gastrointestinal nerves are crucial in the sensing of nutrients and hormones and its translation in terms of control of food intake. Major macronutrients like glucose and protein are sensed by the extrinsic nerves located in the portal vein walls, which signal to the brain and account for the satiety phenomenon they promote. Glucose is sensed in the portal vein by neurons expressing the glucose receptor SGLT3, which activate the main regions of the brain involved in the control of food intake. Proteins indirectly act on food intake by inducing intestinal gluconeogenesis and its sensing by the portal glucose sensor. The mechanism involves a prior antagonism by peptides of the μ-opioid receptors present in the portal vein nervous system and a reflex arc with the brain inducing intestinal gluconeogenesis. In a comparable manner, short-chain fatty acids produced from soluble fibre act via intestinal gluconeogenesis to exert anti-obesity and anti-diabetic effects. In the case of propionate, the mechanism involves a prior activation of the free fatty acid receptor FFAR3 present in the portal nerves and a reflex arc initiating intestinal gluconeogenesis. © 2014 John Wiley & Sons Ltd.

  16. Autologous alternative veins may not provide better outcomes than prosthetic conduits for below-knee bypass when great saphenous vein is unavailable.

    Science.gov (United States)

    Avgerinos, Efthymios D; Sachdev, Ulka; Naddaf, Abdallah; Doucet, Dannielle R; Mohapatra, Abhisekh; Leers, Steven A; Chaer, Rabih A; Makaroun, Michel S

    2015-08-01

    There is a need to better define the role of alternative autologous vein (AAV) segments over contemporary prosthetic conduits in patients with critical limb ischemia when great saphenous vein (GSV) is not available for use as the bypass conduit. Consecutive patients who underwent bypass to infrageniculate targets between 2007 and 2011 were categorized in three groups: GSV, AAV, and prosthetic. The primary outcome was graft patency. The secondary outcome was limb salvage. Cox proportional hazards regression was used to adjust for baseline confounding variables. A total of 407 infrainguinal bypasses to below-knee targets were analyzed; 255 patients (63%) received a single-segment GSV, 106 patients (26%) received an AAV, and 46 patients (11%) received a prosthetic conduit. Baseline characteristics were similar among groups, with the exception of popliteal targets and anticoagulation use being more frequent in the prosthetic group. Primary patency at 2 and 5 years was estimated at 47% and 32%, respectively, for the GSV group; 24% and 23% for the AAV group; and 43% and 38% for the prosthetic group. Primary assisted patency at 2 and 5 years was estimated at 71% and 55%, respectively, for the GSV group; 53% and 51% for the AAV group; and 45% and 40% for the prosthetic group. Secondary patency at 2 and 5 years was estimated at 75% and 60%, respectively, for the GSV group; 57% and 55% for the AAV group; and 46% and 41% for the prosthetic group. In Cox analysis, primary patency (hazard ratio [HR], 0.55; P < .001; 95% confidence interval [CI], 0.404-0.758), primary assisted patency (HR, 0.57; P = .004; 95% CI, 0.388-0.831), and secondary patency (HR, 0.56; P = .005; 95% CI, 0.372-0.840) were predicted by GSV compared with AAV, but there was no difference between AAV and prosthetic grafts except for the primary patency, for which prosthetic was protective (HR, 0.38; P < .001; 95% CI, 0.224-0.629). Limb salvage was similar among groups. AAV conduits may not offer a significant

  17. Patterning of leaf vein networks by convergent auxin transport pathways.

    Science.gov (United States)

    Sawchuk, Megan G; Edgar, Alexander; Scarpella, Enrico

    2013-01-01

    The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM)-localized PIN-FORMED1 (PIN1) intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

  18. Patterning of leaf vein networks by convergent auxin transport pathways.

    Directory of Open Access Journals (Sweden)

    Megan G Sawchuk

    Full Text Available The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM-localized PIN-FORMED1 (PIN1 intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

  19. Comparison between mechanical properties of human saphenous vein and umbilical vein

    Directory of Open Access Journals (Sweden)

    Hamedani Borhan

    2012-08-01

    Full Text Available Abstract Background As a main cause of mortality in developed countries, Coronary Artery Disease (CAD is known as silent killer with a considerable cost to be dedicated for its treatment. Coronary Artery Bypass Graft (CABG is a common remedy for CAD for which different blood vessels are used as a detour. There is a lack of knowledge about mechanical properties of human blood vessels used for CABG, and while these properties have a great impact on long-term patency of a CABG. Thus, studying these properties, especially those of human umbilical veins which have not been considered yet, looks utterly necessary. Methods Umbilical vein, as well as human Saphenous vein, are respectively obtained after cesarean and CABG. First, histological tests were performed to investigate different fiber contents of the samples. Having prepared samples carefully, force-displacement results of samples were rendered to real stress–strain measurements and then a fourth-order polynomial was used to prove the non-linear behavior of these two vessels. Results Results were analyzed in two directions, i.e. circumferentially and longitudinally, which then were compared with each other. The comparison between stiffness and elasticity of these veins showed that Saphenous vein’s stiffness is much higher than that of umbilical vein and also, it is less stretchable. Furthermore, for both vessels, longitudinal stiffness was higher than that of circumferential and in stark contrast, stretch ratio in circumferential direction came much higher than longitudinal orientation. Conclusion Blood pressure is very high in the region of aorta, so there should be a stiff blood vessel in this area and previous investigations showed that stiffer vessels would have a better influence on the flow of bypass. To this end, the current study has made an attempt to compare these two blood vessels’ stiffness, finding that Saphenous vein is stiffer than umbilical vein which is somehow as stiff as

  20. STOPDVTs: Development and testing of a clinical assessment tool to guide nursing assessment of postoperative patients for Deep Vein Thrombosis.

    Science.gov (United States)

    O'Brien, Alanna; Redley, Bernice; Wood, Beverley; Botti, Mari; Hutchinson, Anastasia F

    2018-03-01

    To develop and test a clinical tool to guide nurses' assessment of postoperative patients for Deep Vein Thrombosis. Preventing venous thromboembolism in hospitalised patients is an international patient safety priority. Despite high-level evidence for optimal venous thromboembolism prophylaxis, implementation is inconsistent and the incidence of Deep Vein Thrombosis remains high. A two-stage sequential multi-method design was used. In stage 1, the STOPDVTs tool was developed using a review of the literature and focus groups with local clinical experts. Stage 2 involved pilot testing the tool with 38 surgical nurses who conducted repeated assessments on a prospective sample of 50 postoperative orthopaedic patients. Stage 1: The focus group members who were members of the nursing leadership team agreed on eight local and systemic signs and symptoms that should be included in a nursing patient assessment tool for early Deep Vein Thrombosis. Local symptoms were pain in the limbs, calf swelling and tightness, changes in the affected limb's skin temperature. Systemic signs included in the tool were as follows: increased shortness of breath, increased respiratory and heart rates, and decreased oxygen saturation. Stage 2: The STOPDVTs tool had acceptable face and content validity, the agreement between the expert nurse and surgical nurses on assessments of individual signs and symptoms varied between 44%-94%. Surgical nurses were less likely than the expert nurse to identify signs indicative of Deep Vein Thrombosis. Despite finding the STOPDVTs clinical assessment tool was a useful guide for nursing assessment, surgical nurses often underestimated the potential importance of clinical signs. The findings reveal a gap in nursing knowledge and skill in assessing for Deep Vein Thrombosis in postoperative orthopaedic patients. This study identified a possible risk to patient safety related to under-recognition of the signs and symptoms of possible Deep Vein Thrombosis (DVT) in

  1. Pharmacokinetics, pharmacodynamics and local tolerance at injection site of marbofloxacin administered by regional intravenous limb perfusion in standing horses.

    Science.gov (United States)

    Lallemand, Elodie; Trencart, Pierre; Tahier, Carine; Dron, Frederic; Paulin, Angelique; Tessier, Caroline

    2013-08-01

    To evaluate pharmacokinetic-pharmacodynamic variables and local tolerance at injection-site of marbofloxacin administered via regional intravenous limb perfusion (RIVLP) in standing horses. Adult horses (n = 6). RIVLP were performed with rubber tourniquets applied to the forelimbs of standing sedated horses. Marbofloxacin (0.67 mg/kg) was randomly injected in 1 forelimb, with the contralateral limb serving as a control (0.9% NaCl solution). Samples of jugular blood and synovial fluid from the radiocarpal joint of the marbofloxacin-perfused limb were collected before and at intervals after RIVLP for determination of drug concentrations. All injection sites were evaluated before, 24 and 48 hours after RIVLP by means of ultrasonographic examination, circumferential measurements and subjective visible inflammation scores by veterinarians unaware of treatment received. No adverse effects associated with the technique or antibiotic were observed. High marbofloxacin concentrations were obtained in the synovial fluid, AUCINF was significantly higher in synovial fluid than in plasma (78.64 ± 49.41 and 2.85 ± 0.60 µg h/mL respectively, P = .028). The efficacy indices, AUC0-24 /MIC90 and Cmaxobs/MIC90 , predicted a favorable outcome in the treatment of synovial fluid infections caused by enterobacteriaceae and Staphylococcus aureus. After RIVLP, there was no statistically significant difference between marbofloxacin-injected and control limbs for lameness, visual inflammation score, limb circumference, and ultrasonographic appearance of the veins. Marbofloxacin injected limbs had a significantly greater subcutaneous thickness, compared with control limbs. These data suggest that RIVLP of marbofloxacin (0.67 mg/kg) could be a safe and effective method for treatment of infections of the distal portion of the limb for susceptible organisms. © Copyright 2013 by The American College of Veterinary Surgeons.

  2. Absence of Middle Hepatic Vein Combined with Retro-Aortic Left Renal Vein: a Very Rare Case Report

    Directory of Open Access Journals (Sweden)

    Sezer Akçer

    2012-06-01

    Full Text Available The hepatic and renal veins drain into the inferior vena cava. The upper group of hepatic veins consists of three veins which extend to the posterior face of the liver to join the inferior cava. The left renal vein passes anterior to the aorta just below the origin of the superior mesenteric artery. We detected a variation in the hepatic and renal veins in a multislice CT angiogram of a nine-year-old male patient in the Radiology Department of Afyon Kocatepe University Medical School. The upper group hepatic veins normally drains into the inferior vena cava as three separate trunks, namely the right, left and middle. In our case, we found that only the right and left hepatic veins existed and the middle hepatic vein was absent. Furthermore, the left renal vein, which normally passes anterior to the abdominal aorta, was retro-aortic. Left renal vein variations are of great importance in planning retroperitoneal surgery and vascular interventions. Knowledge of a patient’s hepatic vein and renovascular anatomy and determining their variations and anomalies are of critical importance to abdominal operations, transplantations and preoperative evaluation of endovascular interventions.

  3. Diagnosis and treatment of upper limb apraxia

    OpenAIRE

    Dovern, A.; Fink, G. R.; Weiss, P. H.

    2012-01-01

    Upper limb apraxia, a disorder of higher motor cognition, is a common consequence of left-hemispheric stroke. Contrary to common assumption, apraxic deficits not only manifest themselves during clinical testing but also have delirious effects on the patients’ everyday life and rehabilitation. Thus, a reliable diagnosis and efficient treatment of upper limb apraxia is important to improve the patients’ prognosis after stroke. Nevertheless, to date, upper limb apraxia is still an underdiagnosed...

  4. Development and the evolvability of human limbs

    OpenAIRE

    Young, Nathan M.; Wagner, Günter P.; Hallgrímsson, Benedikt

    2010-01-01

    The long legs and short arms of humans are distinctive for a primate, the result of selection acting in opposite directions on each limb at different points in our evolutionary history. This mosaic pattern challenges our understanding of the relationship of development and evolvability because limbs are serially homologous and genetic correlations should act as a significant constraint on their independent evolution. Here we test a developmental model of limb covariation in anthropoid primate...

  5. Efficacy of duplex ultrasound surveillance after infrainguinal vein bypass may be enhanced by identification of characteristics predictive of graft stenosis development.

    Science.gov (United States)

    Tinder, Chelsey N; Chavanpun, Joe P; Bandyk, Dennis F; Armstrong, Paul A; Back, Martin R; Johnson, Brad L; Shames, Murray L

    2008-09-01

    Controversy regarding the efficacy of duplex ultrasound surveillance after infrainguinal vein bypass led to an analysis of patient and bypass graft characteristics predictive for development of graft stenosis and a decision of secondary intervention. Retrospective analysis of a contemporary, consecutive series of 353 clinically successful infrainguinal vein bypasses performed in 329 patients for critical (n = 284; 80%) or noncritical (n = 69; 20%) limb ischemia enrolled in a surveillance program to identify and repair duplex-detected graft stenosis. Variables correlated with graft stenosis and bypass repair included: procedure indication, conduit type (saphenous vs nonsaphenous vein; reversed vs nonreversed orientation), prior bypass graft failure, postoperative ankle-brachial index (ABI) < 0.85, and interpretation of the first duplex surveillance study as "normal" or "abnormal" based on peak systolic velocity (PSV) and velocity ratio (Vr) criteria. Overall, 126 (36%) of the 353 infrainguinal bypasses had 174 secondary interventions (endovascular, 100; surgery, 74) based on duplex surveillance; resulting in 3-year Kaplan-Meier primary (46%), assisted-primary (80%), and secondary (81%) patency rates. Characteristics predictive of duplex-detected stenosis leading to intervention (PSV: 443 +/- 94 cm/s; Vr: 8.6 +/- 9) were: "abnormal" initial duplex testing indicating moderate (PSV: 180-300 cm/s, Vr: 2-3.5) stenosis (P < .0001), non-single segment saphenous vein conduit (P < .01), warfarin drug therapy (P < .01), and redo bypass grafting (P < .001). Procedure indication, postoperative ABI level, statin drug therapy, and vein conduit orientation were not predictive of graft revision. The natural history of 141 (40%) bypasses with an abnormal first duplex scan differed from "normal" grafts by more frequent (51% vs 24%, P < .001) and earlier (7 months vs 11 months) graft revision for severe stenosis and a lower 3-year assisted primary patency (68% vs 87%; P < .001). In 52

  6. Radiologic analysis of congenital limb anomalies

    International Nuclear Information System (INIS)

    Chung, Hong Jun; Kim, Ok Hwa; Shinn, Kyung Sub; Kim, Nam Ae

    1994-01-01

    Congenital limb anomalies are manifested in various degree of severity and complexity bearing conclusion for description and nomenclature of each anomaly. We retrospectively analyzed the roentgenograms of congenital limb anomalies for the purpose of further understanding of the radiologic manifestations based on the embryonal defect and also to find the incidence of each anomaly. Total number of the patients was 89 with 137 anomalies. Recently the uniform system of classification for congenital anomalies of the upper limb was adopted by International Federation of Societies for Surgery of the Hand (IFSSH), which were categorized as 7 classifications. We used the IFSSH classification with some modification as 5 classifications; failure of formation of parts, failure of differentiation of parts, duplications, overgrowth and undergrowth. The patients with upper limb anomalies were 65 out of 89(73%), lower limb were 21(24%), and both upper and lower limb anomalies were 3(4%). Failure of formation was seen in 18%, failure of differentiation 39%, duplications 39%, overgrowth 8%, and undergrowth in 12%. Thirty-five patients had more than one anomaly, and 14 patients had intergroup anomalies. The upper limb anomalies were more common than lower limb. Among the anomalies, failure of differentiation and duplications were the most common types of congenital limb anomalies. Patients with failure of formation, failure of differentiation, and undergrowth had intergroup association of anomalies, but duplication and overgrowth tended to be isolated anomalies

  7. Anisotropic hydrodynamics for conformal Gubser flow

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Michael; Nopoush, Mohammad [Kent State University, Kent OH 44242 (United States); Ryblewski, Radoslaw [The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland)

    2016-12-15

    In this proceedings contribution, we review the exact solution of the anisotropic hydrodynamics equations for a system subject to Gubser flow. For this purpose, we use the leading-order anisotropic hydrodynamics equations which assume that the distribution function is ellipsoidally symmetric in local-rest-frame momentum. We then prove that the SO(3){sub q} symmetry in de Sitter space constrains the anisotropy tensor to be of spheroidal form with only one independent anisotropy parameter remaining. As a consequence, the exact solution reduces to the problem of solving two coupled non-linear differential equations. We show that, in the limit that the relaxation time goes to zero, one obtains Gubser's ideal hydrodynamic solution and, in the limit that the relaxation time goes to infinity, one obtains the exact free streaming solution obtained originally by Denicol et al. For finite relaxation time, we solve the equations numerically and compare to the exact solution of the relaxation-time-approximation Boltzmann equation subject to Gubser flow. Using this as our standard, we find that anisotropic hydrodynamics describes the spatio-temporal evolution of the system better than all currently known dissipative hydrodynamics approaches.

  8. Hydrodynamic Modeling and Its Application in AUC.

    Science.gov (United States)

    Rocco, Mattia; Byron, Olwyn

    2015-01-01

    The hydrodynamic parameters measured in an AUC experiment, s(20,w) and D(t)(20,w)(0), can be used to gain information on the solution structure of (bio)macromolecules and their assemblies. This entails comparing the measured parameters with those that can be computed from usually "dry" structures by "hydrodynamic modeling." In this chapter, we will first briefly put hydrodynamic modeling in perspective and present the basic physics behind it as implemented in the most commonly used methods. The important "hydration" issue is also touched upon, and the distinction between rigid bodies versus those for which flexibility must be considered in the modeling process is then made. The available hydrodynamic modeling/computation programs, HYDROPRO, BEST, SoMo, AtoB, and Zeno, the latter four all implemented within the US-SOMO suite, are described and their performance evaluated. Finally, some literature examples are presented to illustrate the potential applications of hydrodynamics in the expanding field of multiresolution modeling. © 2015 Elsevier Inc. All rights reserved.

  9. Anisotropic hydrodynamics for conformal Gubser flow

    International Nuclear Information System (INIS)

    Strickland, Michael; Nopoush, Mohammad; Ryblewski, Radoslaw

    2016-01-01

    In this proceedings contribution, we review the exact solution of the anisotropic hydrodynamics equations for a system subject to Gubser flow. For this purpose, we use the leading-order anisotropic hydrodynamics equations which assume that the distribution function is ellipsoidally symmetric in local-rest-frame momentum. We then prove that the SO(3)_q symmetry in de Sitter space constrains the anisotropy tensor to be of spheroidal form with only one independent anisotropy parameter remaining. As a consequence, the exact solution reduces to the problem of solving two coupled non-linear differential equations. We show that, in the limit that the relaxation time goes to zero, one obtains Gubser's ideal hydrodynamic solution and, in the limit that the relaxation time goes to infinity, one obtains the exact free streaming solution obtained originally by Denicol et al. For finite relaxation time, we solve the equations numerically and compare to the exact solution of the relaxation-time-approximation Boltzmann equation subject to Gubser flow. Using this as our standard, we find that anisotropic hydrodynamics describes the spatio-temporal evolution of the system better than all currently known dissipative hydrodynamics approaches.

  10. Quantification of deep medullary veins at 7 T brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kuijf, Hugo J.; Viergever, Max A.; Vincken, Koen L. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Bouvy, Willem H.; Razoux Schultz, Tom B.; Biessels, Geert Jan [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Zwanenburg, Jaco J.M. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands)

    2016-10-15

    Deep medullary veins support the venous drainage of the brain and may display abnormalities in the context of different cerebrovascular diseases. We present and evaluate a method to automatically detect and quantify deep medullary veins at 7 T. Five participants were scanned twice, to assess the robustness and reproducibility of manual and automated vein detection. Additionally, the method was evaluated on 24 participants to demonstrate its application. Deep medullary veins were assessed within an automatically created region-of-interest around the lateral ventricles, defined such that all veins must intersect it. A combination of vesselness, tubular tracking, and hysteresis thresholding located individual veins, which were quantified by counting and computing (3-D) density maps. Visual assessment was time-consuming (2 h/scan), with an intra-/inter-observer agreement on absolute vein count of ICC = 0.76 and 0.60, respectively. The automated vein detection showed excellent inter-scan reproducibility before (ICC = 0.79) and after (ICC = 0.88) visually censoring false positives. It had a positive predictive value of 71.6 %. Imaging at 7 T allows visualization and quantification of deep medullary veins. The presented method offers fast and reliable automated assessment of deep medullary veins. (orig.)

  11. Computed tomographic evaluation of the portal vein in the hepatomas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    1986-10-15

    Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

  12. Computed tomographic evaluation of the portal vein in the hepatomas

    International Nuclear Information System (INIS)

    Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam

    1986-01-01

    Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

  13. Percutaneous aspiration thrombectomy with adjunctive venoplasty for iliac vein compression syndrome with lower extremity deep venous thrombosis

    International Nuclear Information System (INIS)

    Wang Yiping; Zhang Xiquan; Sun Yequan

    2013-01-01

    Objective: To investigate the clinical effect of mechanical aspiration thrombectomy with adjunctive PTA and stenting for iliac vein compression syndrome with lower extremity deep venous thrombosis. Materials and Methods: The clinical data of 184 patients who had iliac vein compression syndrome with lower extremity DVT were analyzed retrospectively. The healthy femoral vein was accessed, then a 12-14 F sheath was introduced via a guide wire to aspirate thrombus in the iliofemoral; For the cases with femoropopliteal thrombus, the thrombus was macerated and pulled by Fogarty balloon catheter, then performing mechanical aspiration thrombectomy. After thrombus removal, PTA and stenting were performed on stenosis or occlusion of common iliac vein that displayed on venography. Results: The thrombus removal rate: Grade Ⅲ 80.89% and Grade Ⅱ 19.02%. The circumference of affected limbs at 15 cm above and below knee joints were (43.9±4.7) cm and (31.5±4.1) cm, respectively, after being discharged from hospital, the differences were statistical significance (t=6.43, t=-5.79, both P=0.000)compared to be hospitalized. The follow -up result: the treatment efficiency was 97.75%. The stent patency rate of postoperation at 6, 12, and 24 months were 97.19%, 94.94%, 92.13%, respectively, on sonography or digital subtract angiography. Conclusion: Mechanical aspiration thrombectomy with adjunctive venoplasty for iliac vein compression syndrome with lower extremity deep venous thrombosis is an effective and safe therapy having notable therapeutic effect in short l middle-term follow-up and shorter hospitalization time. (authors)

  14. Brachial artery repair using the basilic vein as a reliable conduit in a 3-year-old child

    Directory of Open Access Journals (Sweden)

    Hyunyoung G. Kim

    2017-04-01

    Full Text Available A supracondylar fracture of the humerus is the most common upper extremity fracture in children with concurrent neurovascular complications. However, bypass grafting in the management of a pediatric open elbow dislocation with an arterial injury has rarely been reported in the literature. Hence, an adequate conduit for a vessel graft interposition remains questionable when a primary anastomosis is limited in an arterial reconstruction. The purpose of this study is to present a brachial artery reconstruction in a 3-year-old patient with an open supracondylar fracture of the humerus. In the clinical and surgical examination of the patient, an open wound in the left antecubital fossa presented with accompanying brachial artery injury. To repair the artery, a reverse end-to-end anastomosis was conducted using basilic vein graft from the ipsilateral arm under general anesthesia. The patient had palpable radial pulses in the postoperative clinical examination and was discharged without complications. The great saphenous vein (GSV has proven to be the most common and the best conduit for arterial reconstruction of the upper extremity in the adult patients. However, the GSV graft is known to have the propensity for becoming aneurysmal in pediatric patients. Some studies have demonstrated the basilic vein as a suitable conduit in pediatric patients, in that it has durable patency, fewer branches, size compatibility for anastomosis, and proximity to the brachial artery. Our case confirms the safety of using this autogenous vein from within the zone of injury for arterial reconstruction, after a supracondylar humeral fracture. The management of pediatric elbow fractures accompanying vascular injuries can be technically demanding due to relatively small, delicate structures and concurrent neurovascular network. Nonetheless, a vascular injury should be treated with high level of suspicion and immediate intervention to avoid any limb ischemia or loss. In

  15. Mesenteric vein thrombosis after percitaneous transhepatic portal vein catheterisation for the localisation of an insulinoma

    International Nuclear Information System (INIS)

    Luska, G.; Langer, H.E.; Le Blanc, S.; Medizinische Hochschule Hannover

    1984-01-01

    The authors report on a fatal mesenteric vein thrombosis following an uncomplicated percutaneous transhepatic portal vein catheterisation for the localisation of an insulinoma. Several hours after the procedure the patient developed an acute abdomen. An emergency laparotomy revealed a haemorrhagic infarct of the ileum. The resected specimen showed an acute phlebitis with fresh thrombus. The cause of the phlebothrombosis was thought to be intimal damage from high osmolar contrast medium. There was no evidence of damage due to the catheder, either on the phlebogram or pathologically. (orig.) [de

  16. Mechanobiology of embryonic limb development.

    Science.gov (United States)

    Nowlan, Niamh C; Murphy, Paula; Prendergast, Patrick J

    2007-04-01

    Considerable evidence exists to support the hypothesis that mechanical forces have an essential role in healthy embryonic skeletal development. Clinical observations and experimental data indicate the importance of muscle contractions for limb development. However, the influence of these forces is seldom referred to in biological descriptions of bone development, and perhaps this is due to the fact that the hypothesis that mechanical forces are essential for normal embryonic skeletal development is difficult to test and elaborate experimentally in vivo, particularly in humans. Computational modeling has the potential to address this issue by simulating embryonic growth under a range of loading conditions but the potential of such models has yet to be fully exploited. In this article, we review the literature on mechanobiology of limb development in three main sections: (a) experimental alteration of the mechanical environment, (b) mechanical properties of embryonic tissues, and (c) the use of computational models. Then we analyze the main issues, and suggest how experimental and computational fields could work closer together to enhance our understanding of mechanobiology of the embryonic skeleton.

  17. Adjustments to amputation and an artificial limb in lower limb amputees

    NARCIS (Netherlands)

    Sinha, Richa; van den Heuvel, Wim J. A.; Arokiasamy, Perianayagam

    Background: Positive adjustments to amputation and an artificial limb play important roles in the rehabilitation process. Objectives: To study the different facets of adjustments to amputation and an artificial limb in lower limb amputees and to assess the possible role of different background and

  18. Radionuclide venography of lower limbs by subcutaneous injection; A clinical evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chung-Chieng; Jong, Shiang-Bin (Kaohsiung Medical Coll., Taiwan (China))

    1993-02-01

    SC-RNV, radionuclide venography by subcutaneous injection of Tc-99m pertechnetate at acupuncture points K-3, a new alternative of lower limb venography, was recently developed in our clinical laboratory. In some of the previous studies, we have proved its superiority to radionuclide venography by intravenous injection. The current investigation was conducted to understand the reliability of SC-RNV in the diagnosis of deep vein thrombosis (DVT). Fifty-seven cases with lower leg edema, from November 1989 through October 1990, received both SC-RNV and duplex US for causative evaluation. As a result of duplex US, 26 were considered normal (non-DVT), 19 were classified as unilateral DVT, and 12 as bilateral DVT. In nineteen cases (61%, 19/31) with DVT also a XCT and/or a CV (contrast venography) was taken, that showed compatible results. All of the non-DVT had a normal pattern of SC-RNV, all of the unilateral DVT had unilateral impairment of deep vein drainage in SC-RNV, and all of the bilateral DVT had impaired deep venous drainage bilaterally in SC-RNV. It is therefore, concluded that SC-RNV is one of the best choices among available non-invasive lower-limb venographic methods. (author).

  19. A theoretical study of hydrodynamic cavitation.

    Science.gov (United States)

    Arrojo, S; Benito, Y

    2008-03-01

    The optimization of hydrodynamic cavitation as an AOP requires identifying the key parameters and studying their effects on the process. Specific simulations of hydrodynamic bubbles reveal that time scales play a major role on the process. Rarefaction/compression periods generate a number of opposing effects which have demonstrated to be quantitatively different from those found in ultrasonic cavitation. Hydrodynamic cavitation can be upscaled and offers an energy efficient way of generating cavitation. On the other hand, the large characteristic time scales hinder bubble collapse and generate a low number of cavitation cycles per unit time. By controlling the pressure pulse through a flexible cavitation chamber design these limitations can be partially compensated. The chemical processes promoted by this technique are also different from those found in ultrasonic cavitation. Properties such as volatility or hydrophobicity determine the potential applicability of HC and therefore have to be taken into account.

  20. Shear viscosity, cavitation and hydrodynamics at LHC

    International Nuclear Information System (INIS)

    Bhatt, Jitesh R.; Mishra, Hiranmaya; Sreekanth, V.

    2011-01-01

    We study evolution of quark-gluon matter in the ultrarelativistic heavy-ion collisions within the frame work of relativistic second-order viscous hydrodynamics. In particular, by using the various prescriptions of a temperature-dependent shear viscosity to the entropy ratio, we show that the hydrodynamic description of the relativistic fluid becomes invalid due to the phenomenon of cavitation. For most of the initial conditions relevant for LHC, the cavitation sets in very early stage. The cavitation in this case is entirely driven by the large values of shear viscosity. Moreover we also demonstrate that the conformal terms used in equations of the relativistic dissipative hydrodynamic can influence the cavitation time.

  1. The RAGE radiation-hydrodynamic code

    Energy Technology Data Exchange (ETDEWEB)

    Gittings, Michael; Clover, Michael; Betlach, Thomas; Byrne, Nelson; Ranta, Dale [Science Applications International Corp. MS A-1, 10260 Campus Point Drive, San Diego, CA 92121 (United States); Weaver, Robert; Coker, Robert; Dendy, Edward; Hueckstaedt, Robert; New, Kim; Oakes, W Rob [Los Alamos National Laboratory, MS T087, PO Box 1663, Los Alamos, NM 87545 (United States); Stefan, Ryan [TaylorMade-adidas Golf, 5545 Fermi Court, Carlsbad, CA 92008-7324 (United States)], E-mail: michael.r.clover@saic.com

    2008-10-01

    We describe RAGE, the 'radiation adaptive grid Eulerian' radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov solver, to which we have made significant improvements to increase the advection algorithm's robustness and to converge stiffnesses in the equation of state. Similarly, the radiation transport is a basic gray diffusion, but our treatment of the radiation-material coupling, wherein we converge nonlinearities in a novel manner to allow larger timesteps and more robust behavior, can be applied to any multi-group transport algorithm.

  2. The RAGE radiation-hydrodynamic code

    International Nuclear Information System (INIS)

    Gittings, Michael; Clover, Michael; Betlach, Thomas; Byrne, Nelson; Ranta, Dale; Weaver, Robert; Coker, Robert; Dendy, Edward; Hueckstaedt, Robert; New, Kim; Oakes, W Rob; Stefan, Ryan

    2008-01-01

    We describe RAGE, the 'radiation adaptive grid Eulerian' radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov solver, to which we have made significant improvements to increase the advection algorithm's robustness and to converge stiffnesses in the equation of state. Similarly, the radiation transport is a basic gray diffusion, but our treatment of the radiation-material coupling, wherein we converge nonlinearities in a novel manner to allow larger timesteps and more robust behavior, can be applied to any multi-group transport algorithm

  3. Arabidopsis thaliana Ei-5: Minor Vein Architecture Adjustment Compensates for Low Vein Density in Support of Photosynthesis.

    Science.gov (United States)

    Stewart, Jared J; Polutchko, Stephanie K; Demmig-Adams, Barbara; Adams, William W

    2018-01-01

    An Arabidopsis thaliana accession with naturally low vein density, Eifel-5 (Ei-5), was compared to Columbia-0 (Col-0) with respect to rosette growth, foliar vein architecture, photosynthesis, and transpiration. In addition to having to a lower vein density, Ei-5 grew more slowly, with significantly lower rates of rosette expansion, but had similar capacities for photosynthetic oxygen evolution on a leaf area basis compared to Col-0. The individual foliar minor veins were larger in Ei-5, with a greater number of vascular cells per vein, compared to Col-0. This compensation for low vein density resulted in similar values for the product of vein density × phloem cell number per minor vein in Ei-5 and Col-0, which suggests a similar capacity for foliar sugar export to support similar photosynthetic capacities per unit leaf area. In contrast, the product of vein density × xylem cell number per minor vein was significantly greater in Ei-5 compared to Col-0, and was associated not only with a higher ratio of water-transporting tracheary elements versus sugar-transporting sieve elements but also significantly higher foliar transpiration rates per leaf area in Ei-5. In contrast, previous studies in other systems had reported higher ratios of tracheary to sieve elements and higher transpiration rate to be associated with higher - rather than lower - vein densities. The Ei-5 accession thus further underscores the plasticity of the foliar vasculature by illustrating an example where a higher ratio of tracheary to sieve elements is associated with a lower vein density. Establishment of the Ei-5 accession, with a low vein density but an apparent overcapacity for water flux through the foliar xylem network, may have been facilitated by a higher level of precipitation in its habitat of origin compared to that of the Col-0 accession.

  4. Mineral vein dynamics modeling (FRACS). Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Urai, J.; Virgo, S.; Arndt, M. [RWTH Aachen (Germany). Geologie-Endogene Dynamik] [and others

    2013-07-15

    The Mineral Vein Dynamics Modeling group ''FRACS'' is a team of 7 research groups from the Universities of Mainz, Aachen, Tuebingen, Karlsruhe, Bayreuth, ETH Zuerich and Glasgow working on an understanding of the dynamic development of fracturing, fluid flow and fracture sealing. World-class field laboratories, especially carbonate sequences from the Oman Mountains are studied and classified. State of the art numerical programs are written, expanded and used to simulate the dynamic interaction of fracturing, flow and resealing and the results are compared with the natural examples. Newest analytical technologies including laser scanning, high resolution X-ray microtomography, fluid inclusion and isotope analysis are performed to understand and compare the results of simulations with natural examples. A new statistical program was developed to classify the natural fracture and vein systems and compare them with dynamic numerical simulations and analytical models. The results of the first project phase are extremely promising. Most of the numerical models have been developed up to the stage where they can be used to simulate the natural examples. The models allow a definition of the first proxies for high fluid pressure and tectonic stresses. It was found out that the Oman Mountains are a complex and very dynamic system that constantly fractures and reseals from the scale of small veins up to the scale of large normal and strike slip faults. The numerical simulations also indicate that the permeability of such systems is not a constant but that the system adjusts to the driving force, for ex-ample high fluid pressure. When the system reseals fast a fluctuating behavior can be observed in the models where the system constantly fractures and reseals, which is in accordance with the observation of the natural laboratory.

  5. Detection of imminent vein graft occlusion: what is the optimal surveillance program?

    Science.gov (United States)

    Tinder, Chelsey N; Bandyk, Dennis F

    2009-12-01

    The prediction of infrainguinal vein bypass failure remains an inexact judgment. Patient demographics, technical factors, and vascular laboratory graft surveillance testing are helpful in identifying a high-risk graft cohort. The optimal surveillance program to detect the bypass at risk for imminent occlusion continues to be developed, but required elements are known and include clinical assessment for new or changes in limb ischemia symptoms, measurement of ankle and/or toe systolic pressure, and duplex ultrasound imaging of the bypass graft. Duplex ultrasound assessment of bypass hemodynamics may be the most accurate method to detect imminent vein graft occlusion. The finding of low graft flow during intraoperative assessment or at a scheduled surveillance study predicts failure; and if associated with an occlusive lesion, a graft revision can prolong patency. The most common abnormality producing graft failure is conduit stenosis caused by myointimal hyperplasia; and the majority can be repaired by an endovascular intervention. Frequency of testing to detect the failing bypass should be individualized to the patient, the type of arterial bypass, and prior duplex ultrasound scan findings. The focus of surveillance is on identification of the low-flow arterial bypass and timely repair of detected critical stenosis defined by duplex velocity spectra criteria of a peak systolic velocity 300 cm/s and peak systolic velocity ratio across the stenosis >3.5-correlating with >70% diameter-reducing stenosis. When conducted appropriately, a graft surveillance program should result in an unexpected graft failure rate of <3% per year.

  6. Interferon-induced central retinal vein thrombosis

    International Nuclear Information System (INIS)

    Nazir, L.; Husain, A.; Haroon, W.; Shaikh, M.I.; Mirza, S.A.; Khan, Z.

    2012-01-01

    A middle-aged lady presented with sudden onset of unilateral central retinal vein thrombosis after completing 6 months course of interferon and ribavirin for chronic hepatitis C infection. She had no risk factors and all her thrombophilia workup was normal, however, she was found to be dyslipidemic which may have contributed to atherosclerosis and predispose to thrombosis. Despite anticoagulation, her visual acuity deteriorated. This case illustrates the possibility of unpredictable visual complication of interferon. Frequent eye examination should be undertaken in patients having underlying risk factors like diabetes, hypertension or dyslipidemia undergoing interferon therapy. (author)

  7. Interferon-induced central retinal vein thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, L; Husain, A; Haroon, W; Shaikh, M I; Mirza, S A; Khan, Z

    2012-11-15

    A middle-aged lady presented with sudden onset of unilateral central retinal vein thrombosis after completing 6 months course of interferon and ribavirin for chronic hepatitis C infection. She had no risk factors and all her thrombophilia workup was normal, however, she was found to be dyslipidemic which may have contributed to atherosclerosis and predispose to thrombosis. Despite anticoagulation, her visual acuity deteriorated. This case illustrates the possibility of unpredictable visual complication of interferon. Frequent eye examination should be undertaken in patients having underlying risk factors like diabetes, hypertension or dyslipidemia undergoing interferon therapy. (author)

  8. Impact of hydrodynamic stresses on bacterial flagella

    Science.gov (United States)

    Das, Debasish; Riley, Emily; Lauga, Eric

    2017-11-01

    The locomotion of bacteria powered by helical filaments, such as Escherichia coli, critically involves the generation of flows and hydrodynamic stresses which lead to forces and moments balanced by the moment applied by the bacterial rotary motor (which is embedded in the cell wall) and the deformation of the short flexible hook. In this talk we use numerical computations to accurately compute these hydrodynamic stresses, to show how they critically lead to fluid-structure instabilities at the whole-cell level, and enquire if they can be used to rationalise experimental measurements of bacterial motor torques. ERC Consolidator Grant.

  9. Hydrodynamics of quark-gluon plasmas

    International Nuclear Information System (INIS)

    Blaizot, J.P.

    1986-06-01

    This paper reviews some aspects of the hydrodynamics of quark-gluon plasmas. Various stages of ultra-relativistic heavy ion collisions are described. Several estimates of the maximum energy density expected to be achieved in these collisions are compared. Discontinuities which may be induced in the hydrodynamic flow by a phase transition are described and a convenient numerical method designed to deal with such discontinuous flows is briefly presented. Finally, the correlations between particle transverse momenta and multiplicities are analyzed and one discusses to which extent these correlations could signal the occurrence of a phase transition in heavy ion collisions

  10. FDTD for Hydrodynamic Electron Fluid Maxwell Equations

    Directory of Open Access Journals (Sweden)

    Yingxue Zhao

    2015-05-01

    Full Text Available In this work, we develop a numerical method for solving the three dimensional hydrodynamic electron fluid Maxwell equations that describe the electron gas dynamics driven by an external electromagnetic wave excitation. Our numerical approach is based on the Finite-Difference Time-Domain (FDTD method for solving the Maxwell’s equations and an explicit central finite difference method for solving the hydrodynamic electron fluid equations containing both electron density and current equations. Numerical results show good agreement with the experiment of studying the second-harmonic generation (SHG from metallic split-ring resonator (SRR.

  11. Modeling of laser-driven hydrodynamics experiments

    Science.gov (United States)

    di Stefano, Carlos; Doss, Forrest; Rasmus, Alex; Flippo, Kirk; Desjardins, Tiffany; Merritt, Elizabeth; Kline, John; Hager, Jon; Bradley, Paul

    2017-10-01

    Correct interpretation of hydrodynamics experiments driven by a laser-produced shock depends strongly on an understanding of the time-dependent effect of the irradiation conditions on the flow. In this talk, we discuss the modeling of such experiments using the RAGE radiation-hydrodynamics code. The focus is an instability experiment consisting of a period of relatively-steady shock conditions in which the Richtmyer-Meshkov process dominates, followed by a period of decaying flow conditions, in which the dominant growth process changes to Rayleigh-Taylor instability. The use of a laser model is essential for capturing the transition. also University of Michigan.

  12. Fish stocking density impacts tank hydrodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Lunger, Angela; Laursen, Jesper

    2006-01-01

    The effect of stocking density upon the hydrodynamics of a circular tank, configured in a recirculation system, was investigated. Red drums Sciaenops ocellatus of approximately 140 g wet weight, were stocked at five rates varying from 0 to 12 kg m-3. The impact of the presence of fish upon tank...... hydrodynamics was established using in-tank-based Rhodamine WT fluorometry at a flow rate of 0.23 l s-1 (tank exchange rate of 1.9 h-1). With increasing numbers of animals, curvilinear relationships were observed for dispersion coefficients and tank mixing times. Stocking densities of 3, 6, 9 and 12 kg m-3...

  13. Introduction to physics mechanics, hydrodynamics thermodynamics

    CERN Document Server

    Frauenfelder, P

    2013-01-01

    Introduction of Physics: Mechanics , Hydrodynamics, Thermodynamics covers the principles of matter and its motion through space and time, as well as the related concepts of energy and force. This book is composed of eleven chapters, and begins with an introduction to the basic principles of mechanics, hydrodynamics, and thermodynamics. The subsequent chapters deal with the statics of rigid bodies and the dynamics of particles and rigid bodies. These topics are followed by discussions on elasticity, mechanics of fluids, the basic concept of thermodynamic, kinetic theory, and crystal structure o

  14. Shadowfax: Moving mesh hydrodynamical integration code

    Science.gov (United States)

    Vandenbroucke, Bert

    2016-05-01

    Shadowfax simulates galaxy evolution. Written in object-oriented modular C++, it evolves a mixture of gas, subject to the laws of hydrodynamics and gravity, and any collisionless fluid only subject to gravity, such as cold dark matter or stars. For the hydrodynamical integration, it makes use of a (co-) moving Lagrangian mesh. The code has a 2D and 3D version, contains utility programs to generate initial conditions and visualize simulation snapshots, and its input/output is compatible with a number of other simulation codes, e.g. Gadget2 (ascl:0003.001) and GIZMO (ascl:1410.003).

  15. Retrograde endovenous laser ablation through saphenopopliteal junctional area for incompetent small saphenous vein; Comparison with antegrade approach

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Seok; Park, Sang Woo; Yun, Ik Jin; Hwang, Jae Joon; Lee, Song Am; Chee, Hyun Keun; Hwang, Jin Ho [Konkuk University Hospital, Konkuk University School of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    To evaluate the safety and efficacy of retrograde endovenous laser ablation (EVLA) and to compare it with the conventional antegrade EVLA for incompetent small saphenous vein (SSV). Small saphenous vein was cannulated via two approaches under ultrasound-guidance. One method involved puncturing the SSV cranially at mid-calf (the antegrade group). If the antegrade puncture into the SSV failed twice, the other approach for puncture was selected that involved puncturing the SSV toward the ankle (the retrograde group). Patients were evaluated in terms of technical and clinical success, closure rates of the SSV, and complications including pain, bruising, or paresthesia at all follow-up visits. The 1470 nm endovenous laser was used in all limbs. Technical success was seen in all limbs in both groups (100%). Closure rate in both groups showed about 95%, without significant difference (p = 0.685). Similar linear endovenous energy density was supplied during the EVLA in both groups (p = 0.876). Three frequent complications including bruising, pain, and paresthesia did not show statistical significance between groups (p = 0.465, 0.823, 1.000, respectively). Major complications were absent in both groups. The EVLA for the incompetent SSV using a retrograde approach is safe and effective and should be considered the alternative method if the antegrade access fails due to vasospasm or small SSV diameter.

  16. Retrograde endovenous laser ablation through saphenopopliteal junctional area for incompetent small saphenous vein; Comparison with antegrade approach

    International Nuclear Information System (INIS)

    Kim, Jun Seok; Park, Sang Woo; Yun, Ik Jin; Hwang, Jae Joon; Lee, Song Am; Chee, Hyun Keun; Hwang, Jin Ho

    2016-01-01

    To evaluate the safety and efficacy of retrograde endovenous laser ablation (EVLA) and to compare it with the conventional antegrade EVLA for incompetent small saphenous vein (SSV). Small saphenous vein was cannulated via two approaches under ultrasound-guidance. One method involved puncturing the SSV cranially at mid-calf (the antegrade group). If the antegrade puncture into the SSV failed twice, the other approach for puncture was selected that involved puncturing the SSV toward the ankle (the retrograde group). Patients were evaluated in terms of technical and clinical success, closure rates of the SSV, and complications including pain, bruising, or paresthesia at all follow-up visits. The 1470 nm endovenous laser was used in all limbs. Technical success was seen in all limbs in both groups (100%). Closure rate in both groups showed about 95%, without significant difference (p = 0.685). Similar linear endovenous energy density was supplied during the EVLA in both groups (p = 0.876). Three frequent complications including bruising, pain, and paresthesia did not show statistical significance between groups (p = 0.465, 0.823, 1.000, respectively). Major complications were absent in both groups. The EVLA for the incompetent SSV using a retrograde approach is safe and effective and should be considered the alternative method if the antegrade access fails due to vasospasm or small SSV diameter

  17. Early results from an angiosome-directed open surgical technique for venous arterialization in patients with critical lower limb ischemia

    Directory of Open Access Journals (Sweden)

    Kim Houlind

    2013-12-01

    Full Text Available Background: Patients with critical lower limb ischemia without patent pedal arteries cannot be treated by the conventional arterial reconstruction. Venous arterialization has been suggested to improve limb salvage in this subgroup of patients but has not gained wide acceptance. We report our early experience after implementing deep and superficial venous arterialization of the lower limb. Materials and methods: Ten patients with critical ischemia and without crural or pedal arteries available for conventional bypass surgery or angioplasty were treated with distal venous arterialization. Inflow was from the most distal unobstructed segment. Run-off was the dorsal pedal venous arch (n=5, the dorsal pedal venous arch and a concomitant vein of the posterior tibial artery (n=3, or the dorsal pedal venous arch and a concomitant vein of the common plantar artery (n=2 depending on the location of the ischemic lesion. Venous valves were destroyed using antegrade valvulotomes, guide wires, knob needles, or retrograde valvulotomes via an extra incision. Results: Seven of the operated limbs were amputated after 23 (1–256 days (median [range]. The main reasons for amputation were lack of healing of either the original wound, of incisional wounds on the foot, or persisting pain at rest. In three cases, the bypass was open at the time of amputation. Two patients experienced complete wound healing after 231 and 342 days, respectively. By the end of follow-up, the last patient was ambulating with slow wound healing but without pain 309 days after surgery. Conclusion: Venous arterialization may be used as a treatment of otherwise unsalveable limbs. The success rate is, however, limited. Technical optimization of the technique is warranted.

  18. Limb-segment selection in drawing behaviour

    NARCIS (Netherlands)

    Meulenbroek, R G; Rosenbaum, D A; Thomassen, A.J.W.M.; Schomaker, L R

    How do we select combinations of limb segments to carry out physical tasks? Three possible determinants of limb-segment selection are hypothesized here: (1) optimal amplitudes and frequencies of motion for the effectors; (2) preferred movement axes for the effectors; and (3) a tendency to continue

  19. LIMB-SEGMENT SELECTION IN DRAWING BEHAVIOR

    NARCIS (Netherlands)

    MEULENBROEK, RGJ; ROSENBAUM, DA; THOMASSEN, AJWM; SCHOMAKER, LRB; Schomaker, Lambertus

    How do we select combinations of limb segments to carry out physical tasks? Three possible determinants of limb-segment selection are hypothesized here: (1) optimal amplitudes and frequencies of motion for the effectors; (2) preferred movement axes for the effectors; and (3) a tendency to continue

  20. Genomic features of human limb specific enhancers.

    Science.gov (United States)

    Ali, Shahid; Amina, Bibi; Anwar, Saneela; Minhas, Rashid; Parveen, Nazia; Nawaz, Uzma; Azam, Syed Sikandar; Abbasi, Amir Ali

    2016-10-01

    To elucidate important cellular and molecular interactions that regulate patterning and skeletal development, vertebrate limbs served as a model organ. A growing body of evidence from detailed studies on a subset of limb regulators like the HOXD cluster or SHH, reveals the importance of enhancers in limb related developmental and disease processes. Exploiting the recent genome-wide availability of functionally confirmed enhancer dataset, this study establishes regulatory interactions for dozens of human limb developmental genes. From these data, it appears that the long-range regulatory interactions are fairly common during limb development. This observation highlights the significance of chromosomal breaks/translocations in human limb deformities. Transcriptional factor (TF) analysis predicts that the differentiation of early nascent limb-bud into future territories entail distinct TF interaction networks. Conclusively, an important motivation for annotating the human limb specific regulatory networks is to pave way for the systematic exploration of their role in disease and evolution. Copyright © 2016. Published by Elsevier Inc.

  1. A Dynamic Model for Limb Selection

    NARCIS (Netherlands)

    Cox, R.F.A; Smitsman, A.W.

    2008-01-01

    Two experiments and a model on limb selection are reported. In Experiment 1 left-handed and right-handed participants (N = 36) repeatedly used one hand for grasping a small cube. After a clear switch in the cube’s location, perseverative limb selection was revealed in both handedness groups. In

  2. The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb.

    Science.gov (United States)

    Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A; Danish, Qazi

    2016-09-01

    Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation.

  3. Aneurysmal malformation of the extrahepatic portal vein: a case report

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Kang, Sung Soo; Kim, Chong Soo; Han, Hyeun Young

    1999-01-01

    Aneurysmal malformation of the portal vein is a rare entity. To our knowledge, only scattered reports of portal vein aneurysms appear in the literature in English, and there is no previously published report in Korean. We describe a case exhibiting aneurysmal malformation of the extrahepatic portal vein at the hepatic hilum ; the findings demonstrated by ultrasound, CT and angiography are discussed, a review of previously described cases is included

  4. CT of portal vein tumor thrombosis. Usefulness of dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Inoue, Yuichi; Tanaka, Masahiro; Nemoto, Yutaka; Nakamura, Kenji [Osaka City Univ. (Japan). Faculty of Medicine

    1983-08-01

    We evaluated CT findings of portal vein tumor thrombosis in 16 hepatomas by plain, contrast and dynamic CT. Plain and contrast CT findings were an enlargement of the portal vein (81%), intraluminal low density area (63%). Dynamic CT enhanced the diagnostic capability of the tumor thrombus as a relatively low density area because of the marked enhancement of the portal vein. In addition, dynamic CT newly demonstrated hyperdense peripheral ring (35%) and arterio portal shunt (35%). It is advisable to select the scan level to include the portal vein when dynamic CT is performed in the patient of hepatocellular carcinoma.

  5. Radiation Retinopathy Associated with Central Retinal Vein Occlusion

    Institute of Scientific and Technical Information of China (English)

    Yan; Liu; FengWen

    2007-01-01

    Purpose: To report a case of radiation retinopathy associated with central retinal vein occlusion.Methods: The clinical features and fundus fluorescein angiography of this case were analyzed.Results: The patient had been treated with radiotherapy for her nasopharyngeal carcinoma, and presented with sudden visual loss in the left eye. The funduscopic examination and fluorescein angiography showed the features of radiation retinopathy in both eyes, and central retinal vein occlusion in the left eye.Conclusions: Radiation retinopathy can be associated with central retinal vein occlusion in the same eye, and it seems that the endothelial cell loss caused by radiation retinopathy may lead to retinal vein occlusion.

  6. Characterization of a porcine model of chronic superficial varicose veins.

    Science.gov (United States)

    Jones, Gregory T; Grant, Mark W; Thomson, Ian A; Hill, B Geraldine; van Rij, André M

    2009-06-01

    Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins. Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.

  7. [Portal perfusion with right gastroepiploic vein flow in liver transplant].

    Science.gov (United States)

    Mendoza-Sánchez, Federico; Javier-Haro, Francisco; Mendoza-Medina, Diego Federico; González-Ojeda, Alejandro; Cortés-Lares, José Antonio; Fuentes-Orozco, Clotilde

    Liver transplantation in patients with liver cirrhosis, portal vein thrombosis, and cavernous transformation of the portal vein, is a complex procedure with high possibility of liver graft dysfunction. It is performed in 2-19% of all liver transplants, and has a significantly high mortality rate in the post-operative period. Other procedures to maintain portal perfusion have been described, however there are no reports of liver graft perfusion using right gastroepiploic vein. A 20 year-old female diagnosed with cryptogenic cirrhosis, with a Child-Pugh score of 7 points (class "B"), and MELD score of 14 points, with thrombosis and cavernous transformation of the portal vein, severe portal hypertension, splenomegaly, a history of upper gastrointestinal bleeding due to oesophageal varices, and left renal agenesis. The preoperative evaluation for liver transplantation was completed, and the right gastroepiploic vein of 1-cm diameter was observed draining to the infrahepatic inferior vena cava and right suprarenal vein. An orthotopic liver transplantation was performed from a non-living donor (deceased on January 30, 2005) using the Piggy-Back technique. Portal vein perfusion was maintained using the right gastroepiploic vein, and the outcome was satisfactory. The patient was discharged 13 days after surgery. Liver transplantation was performed satisfactorily, obtaining an acceptable outcome. In this case, the portal perfusion had adequate blood flow through the right gastroepiploic vein. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  8. Vein Patch Closure Using Below the Knee Greater Saphenous Vein for Femoral Endarterectomy Procedures is Not Always a Safe Choice

    Directory of Open Access Journals (Sweden)

    M. Berner

    Full Text Available : Background: The complication of vein patch rupture is well described after carotid patch angioplasty; however, there is a paucity of data about the safety of vein patch closure in the setting of femoral endarterectomy. Methods/results: From May 2012 to May 2015, 115 femoral endarterectomies with patch closure were performed. A patch rupture occurred in three cases (2.6% with a mortality rate of 66% (2/3. In all cases the greater saphenous vein below the knee was used as patch material. Discussion/conclusion: Vein patches, particularly from small calibre veins, should be excluded in femoral endarterectomy procedures as they pose a substantial risk of rupture. Keywords: Angioplasty, Patch rupture, Femoral artery, Patch, Great saphenous vein

  9. Artificial limb representation in amputees.

    Science.gov (United States)

    van den Heiligenberg, Fiona M Z; Orlov, Tanya; Macdonald, Scott N; Duff, Eugene P; Henderson Slater, David; Beckmann, Christian F; Johansen-Berg, Heidi; Culham, Jody C; Makin, Tamar R

    2018-05-01

    The human brain contains multiple hand-selective areas, in both the sensorimotor and visual systems. Could our brain repurpose neural resources, originally developed for supporting hand function, to represent and control artificial limbs? We studied individuals with congenital or acquired hand-loss (hereafter one-handers) using functional MRI. We show that the more one-handers use an artificial limb (prosthesis) in their everyday life, the stronger visual hand-selective areas in the lateral occipitotemporal cortex respond to prosthesis images. This was found even when one-handers were presented with images of active prostheses that share the functionality of the hand but not necessarily its visual features (e.g. a 'hook' prosthesis). Further, we show that daily prosthesis usage determines large-scale inter-network communication across hand-selective areas. This was demonstrated by increased resting state functional connectivity between visual and sensorimotor hand-selective areas, proportional to the intensiveness of everyday prosthesis usage. Further analysis revealed a 3-fold coupling between prosthesis activity, visuomotor connectivity and usage, suggesting a possible role for the motor system in shaping use-dependent representation in visual hand-selective areas, and/or vice versa. Moreover, able-bodied control participants who routinely observe prosthesis usage (albeit less intensively than the prosthesis users) showed significantly weaker associations between degree of prosthesis observation and visual cortex activity or connectivity. Together, our findings suggest that altered daily motor behaviour facilitates prosthesis-related visual processing and shapes communication across hand-selective areas. This neurophysiological substrate for prosthesis embodiment may inspire rehabilitation approaches to improve usage of existing substitutionary devices and aid implementation of future assistive and augmentative technologies.

  10. Suitability of Varicose Veins for Endovenous Treatments

    International Nuclear Information System (INIS)

    Goode, S. D.; Kuhan, G.; Altaf, N.; Simpson, R.; Beech, A.; Richards, T.; MacSweeney, S. T.; Braithwaite, B. D.

    2009-01-01

    The aim of the study was to assess the suitability of radiofrequency ablation (RFA), endovenous laser ablation (EVLA), and foam sclerotherapy (FS) for patients with symptomatic varicose veins (VVs). The study comprised 403 consecutive patients with symptomatic VVs. Data on 577 legs from 403 consecutive patients with symptomatic VVs were collected for the year 2006. Median patient age was 55 years (interquartile range 45-66), and 62% patients were women. A set of criteria based on duplex ultrasonography was used to select patients for each procedure. Great saphenous vein (GSV) reflux was present in 77% (446 of 577) of legs. Overall, 328 (73%) of the legs were suitable for at least one of the endovenous options. Of the 114 legs with recurrent GSV reflux disease, 83 (73%) were suitable to receive endovenous therapy. Patients with increasing age were less likely to be suitable for endovenous therapy (P = 0.03). Seventy-three percent of patients with VVs caused by GSV incompetence are suitable for endovenous therapy.

  11. Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

    OpenAIRE

    Madhusudhan, KS; Agrawal, Nikhil; Srivastava, Deep N; Pal, Sujoy; Gupta, Arun K

    2013-01-01

    Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, su...

  12. Impact of Hydrodynamics on Oral Biofilm Strength

    NARCIS (Netherlands)

    Paramonova, E.; Kalmykowa, O. J.; van der Mei, H. C.; Busscher, H. J.; Sharma, P. K.

    2009-01-01

    Mechanical removal of oral biofilms is ubiquitously accepted as the best way to prevent caries and periodontal diseases. Removal effectiveness strongly depends on biofilm strength. To investigate the influence of hydrodynamics on oral biofilm strength, we grew single- and multi-species biofilms of

  13. Hydrodynamic states of phonons in insulators

    Directory of Open Access Journals (Sweden)

    S.A. Sokolovsky

    2012-12-01

    Full Text Available The Chapman-Enskog method is generalized for accounting the effect of kinetic modes on hydrodynamic evolution. Hydrodynamic states of phonon system of insulators have been studied in a small drift velocity approximation. For simplicity, the investigation was carried out for crystals of the cubic class symmetry. It has been found that in phonon hydrodynamics, local equilibrium is violated even in the approximation linear in velocity. This is due to the absence of phonon momentum conservation law that leads to a drift velocity relaxation. Phonon hydrodynamic equations which take dissipative processes into account have been obtained. The results were compared with the standard theory based on the local equilibrium validity. Integral equations have been obtained for calculating the objects of the theory (including viscosity and heat conductivity. It has been shown that in low temperature limit, these equations are solvable by iterations. Steady states of the system have been considered and an expression for steady state heat conductivity has been obtained. It coincides with the famous result by Akhiezer in the leading low temperature approximation. It has been established that temperature distribution in the steady state of insulator satisfies a condition of heat source absence.

  14. Magneto-hydrodynamical model for plasma

    Science.gov (United States)

    Liu, Ruikuan; Yang, Jiayan

    2017-10-01

    Based on the Newton's second law and the Maxwell equations for the electromagnetic field, we establish a new 3-D incompressible magneto-hydrodynamics model for the motion of plasma under the standard Coulomb gauge. By using the Galerkin method, we prove the existence of a global weak solution for this new 3-D model.

  15. Statistical analysis of hydrodynamic cavitation events

    Science.gov (United States)

    Gimenez, G.; Sommer, R.

    1980-10-01

    The frequency (number of events per unit time) of pressure pulses produced by hydrodynamic cavitation bubble collapses is investigated using statistical methods. The results indicate that this frequency is distributed according to a normal law, its parameters not being time-evolving.

  16. Filter-Feeding Zoobenthos and Hydrodynamics

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2017-01-01

    interplay between benthic filter feeders and hydrodynamics. Starting from the general concept of grazing potential and typical data on benthic population densities its realization is considered, first at the level of the individual organism through the processes of pumping and trapping of food particles...

  17. does earthworms density really modify soil's hydrodynamic ...

    African Journals Online (AJOL)

    N. Ababsa,, M. Kribaa, D. Addad, L. Tamrabet and M. Baha

    1 mai 2016 ... Journal of Fundamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCommercial 4.0. International License. Libraries Resource Directory. We are listed under Research Associations category. DOES EARTHWORMS DENSITY REALLY MODIFY SOIL'S HYDRODYNAMIC.

  18. PHANTOM: Smoothed particle hydrodynamics and magnetohydrodynamics code

    Science.gov (United States)

    Price, Daniel J.; Wurster, James; Nixon, Chris; Tricco, Terrence S.; Toupin, Stéven; Pettitt, Alex; Chan, Conrad; Laibe, Guillaume; Glover, Simon; Dobbs, Clare; Nealon, Rebecca; Liptai, David; Worpel, Hauke; Bonnerot, Clément; Dipierro, Giovanni; Ragusa, Enrico; Federrath, Christoph; Iaconi, Roberto; Reichardt, Thomas; Forgan, Duncan; Hutchison, Mark; Constantino, Thomas; Ayliffe, Ben; Mentiplay, Daniel; Hirsh, Kieran; Lodato, Giuseppe

    2017-09-01

    Phantom is a smoothed particle hydrodynamics and magnetohydrodynamics code focused on stellar, galactic, planetary, and high energy astrophysics. It is modular, and handles sink particles, self-gravity, two fluid and one fluid dust, ISM chemistry and cooling, physical viscosity, non-ideal MHD, and more. Its modular structure makes it easy to add new physics to the code.

  19. Microflow Cytometers with Integrated Hydrodynamic Focusing

    Directory of Open Access Journals (Sweden)

    Martin Schmidt

    2013-04-01

    Full Text Available This study demonstrates the suitability of microfluidic structures for high throughput blood cell analysis. The microfluidic chips exploit fully integrated hydrodynamic focusing based on two different concepts: Two-stage cascade focusing and spin focusing (vortex principle. The sample—A suspension of micro particles or blood cells—is injected into a sheath fluid streaming at a substantially higher flow rate, which assures positioning of the particles in the center of the flow channel. Particle velocities of a few m/s are achieved as required for high throughput blood cell analysis. The stability of hydrodynamic particle positioning was evaluated by measuring the pulse heights distributions of fluorescence signals from calibration beads. Quantitative assessment based on coefficient of variation for the fluorescence intensity distributions resulted in a value of about 3% determined for the micro-device exploiting cascade hydrodynamic focusing. For the spin focusing approach similar values were achieved for sample flow rates being 1.5 times lower. Our results indicate that the performances of both variants of hydrodynamic focusing suit for blood cell differentiation and counting. The potential of the micro flow cytometer is demonstrated by detecting immunologically labeled CD3 positive and CD4 positive T-lymphocytes in blood.

  20. Numerical methods for hydrodynamic stability problems

    International Nuclear Information System (INIS)

    Fujimura, Kaoru

    1985-11-01

    Numerical methods for solving the Orr-Sommerfeld equation, which is the fundamental equation of the hydrodynamic stability theory for various shear flows, are reviewed and typical numerical results are presented. The methods of asymptotic solution, finite difference methods, initial value methods and expansions in orthogonal functions are compared. (author)

  1. Hydrodynamic relaxations in dissipative particle dynamics

    Science.gov (United States)

    Hansen, J. S.; Greenfield, Michael L.; Dyre, Jeppe C.

    2018-01-01

    This paper studies the dynamics of relaxation phenomena in the standard dissipative particle dynamics (DPD) model [R. D. Groot and P. B. Warren, J. Chem. Phys. 107, 4423 (1997)]. Using fluctuating hydrodynamics as the framework of the investigation, we focus on the collective transverse and longitudinal dynamics. It is shown that classical hydrodynamic theory predicts the transverse dynamics at relatively low temperatures very well when compared to simulation data; however, the theory predictions are, on the same length scale, less accurate for higher temperatures. The agreement with hydrodynamics depends on the definition of the viscosity, and here we find that the transverse dynamics are independent of the dissipative and random shear force contributions to the stress. For high temperatures, the spectrum for the longitudinal dynamics is dominated by the Brillouin peak for large length scales and the relaxation is therefore governed by sound wave propagation and is athermal. This contrasts the results at lower temperatures and small length scale, where the thermal process is clearly present in the spectra. The DPD model, at least qualitatively, re-captures the underlying hydrodynamical mechanisms, and quantitative agreement is excellent at intermediate temperatures for the transverse dynamics.

  2. Hydrodynamic dispersion of microswimmers in suspension

    Science.gov (United States)

    Martin, Matthieu; Rafaï, Salima; Peyla, Philippe

    2014-11-01

    In our laboratory, we study hydrodynamics of suspensions of micro-swimmers. These micro-organisms are unicellular algae Chlamydomonas Rheinhardii which are able to swim by using their flagella. The swimming dynamics of these micro-swimmers can be seen as a random walk, in absence of any kind of interaction. In addition, these algae have the property of being phototactic, i.e. they swim towards the light. Combining this property with a hydrodynamic flow, we were able to reversibly separate algae from the rest of the fluid. But for sufficiently high volume fraction, these active particles interact with each other. We are now interested in how the coupling of hydrodynamic interactions between swimmers and phototaxis can modify the swimming dynamics at the scale of the suspension. To this aim, we conduct experiments in microfluidic devices to study the dispersion of the micro-organisms in a the liquid phase as a function of the volume fraction. We show that the dispersion of an assembly of puller type microswimmers is quantitatively affected by hydrodynamics interactions. Phd student.

  3. Hydrodynamic modelling of hydrostatic magnesium extrusion

    NARCIS (Netherlands)

    Moodij, Ellen; de Rooij, Matthias B.; Schipper, Dirk J.

    2006-01-01

    Wilson’s hydrodynamic model of the hydrostatic extrusion process is extended to meet the geometry found on residual billets. The transition from inlet to work zone of the process is not considered sharp as in the model of Wilson but as a rounded edge, modelled by a parabolic function. It is shown

  4. Dilepton production in schematic causal viscous hydrodynamics

    International Nuclear Information System (INIS)

    Song, Taesoo; Han, Kyong Chol; Ko, Che Ming

    2011-01-01

    Assuming that in the hot dense matter produced in relativistic heavy-ion collisions, the energy density, entropy density, and pressure as well as the azimuthal and space-time rapidity components of the shear tensor are uniform in the direction transversal to the reaction plane, we derive a set of schematic equations from the Isreal-Stewart causal viscous hydrodynamics. These equations are then used to describe the evolution dynamics of relativistic heavy-ion collisions by taking the shear viscosity to entropy density ratio of 1/4π for the initial quark-gluon plasma (QGP) phase and of 10 times this value for the later hadron-gas (HG) phase. Using the production rate evaluated with particle distributions that take into account the viscous effect, we study dilepton production in central heavy-ion collisions. Compared with results from the ideal hydrodynamics, we find that although the dilepton invariant mass spectra from the two approaches are similar, the transverse momentum spectra are significantly enhanced at high transverse momenta by the viscous effect. We also study the transverse momentum dependence of dileptons produced from QGP for a fixed transverse mass, which is essentially absent in the ideal hydrodynamics, and find that this so-called transverse mass scaling is violated in the viscous hydrodynamics, particularly at high transverse momenta.

  5. Hydrodynamic forces on inundated bridge decks

    Science.gov (United States)

    2009-05-01

    The hydrodynamic forces experienced by an inundated bridge deck have great importance in the design of bridges. Specifically, the drag force, lift force, and the moment acting on the bridge deck under various levels of inundation and a range of flow ...

  6. The quantum hydrodynamics of the Sutherland model

    International Nuclear Information System (INIS)

    Stone, Michael; Gutman, Dmitry

    2008-01-01

    We show that the form of the chiral condition found by Abanov et al in the quantum hydrodynamics of the Sutherland model arises because there are two distinct inner products with respect to which the chiral Hamiltonian is Hermitian, but only one with respect to which the full, non-chiral, Hamiltonian is Hermitian

  7. Hydrodynamic impact response, a flexible view

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Hoogeland, M.; Janssen, G.Th.M.

    2001-01-01

    The popularity of high-speed craft is steadily increasing. Until now, much attention has been focussed on the hydrodynamic aspects of these craft. The structural design of these vessels is usually considered in a quasi static sense. However, due to the requirement of light ship structures, fast ship

  8. Universal hydrodynamics of non-conformal branes

    International Nuclear Information System (INIS)

    Kanitscheider, Ingmar; Skenderis, Kostas

    2009-01-01

    We examine the hydrodynamic limit of non-conformal branes using the recently developed precise holographic dictionary. We first streamline the discussion of holography for backgrounds that asymptote locally to non-conformal brane solutions by showing that all such solutions can be obtained from higher dimensional asymptotically locally AdS solutions by suitable dimensional reduction and continuation in the dimension. As a consequence, many holographic results for such backgrounds follow from the corresponding results of the Asymptotically AdS case. In particular, the hydrodynamics of non-conformal branes is fully determined in terms of conformal hydrodynamics. Using previous results on the latter we predict the form of the non-conformal hydrodynamic stress tensor to second order in derivatives. Furthermore we show that the ratio between bulk and shear viscosity is fixed by the generalized conformal structure to be ζ/η = 2(1/(d-1)-c s 2 ), where c s is the speed of sound in the fluid.

  9. Detailed simulation of morphodynamics : 1. Hydrodynamic model

    NARCIS (Netherlands)

    Nabi, M.; De Vriend, H.J.; Mosselman, E.; Sloff, C.J.; Shimizu, Y.

    2012-01-01

    We present a three-dimensional high-resolution hydrodynamic model for unsteady incompressible flow over an evolving bed topography. This is achieved by using a multilevel Cartesian grid technique that allows the grid to be refined in high-gradient regions and in the vicinity of the river bed. The

  10. On the Nature of Off-limb Flare Continuum Sources Detected by SDO /HMI

    Energy Technology Data Exchange (ETDEWEB)

    Heinzel, P.; Kašparová, J. [Astronomical Institute, Czech Academy of Sciences, 25165 Ondřejov (Czech Republic); Kleint, L.; Krucker, S., E-mail: pheinzel@asu.cas.cz [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland)

    2017-09-20

    The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory has provided unique observations of off-limb flare emission. White-light continuum enhancements were detected in the “continuum” channel of the Fe 6173 Å line during the impulsive phase of the observed flares. In this paper we aim to determine which radiation mechanism is responsible for such enhancement being seen above the limb, at chromospheric heights around or below 1000 km. Using a simple analytical approach, we compare two candidate mechanisms, the hydrogen recombination continuum (Paschen) and the Thomson continuum due to scattering of disk radiation on flare electrons. Both mechanisms depend on the electron density, which is typically enhanced during the impulsive phase of a flare as the result of collisional ionization (both thermal and also non-thermal due to electron beams). We conclude that for electron densities higher than 10{sup 12} cm{sup −3}, the Paschen recombination continuum significantly dominates the Thomson scattering continuum and there is some contribution from the hydrogen free–free emission. This is further supported by detailed radiation-hydrodynamical (RHD) simulations of the flare chromosphere heated by the electron beams. We use the RHD code FLARIX to compute the temporal evolution of the flare-heating in a semi-circular loop. The synthesized continuum structure above the limb resembles the off-limb flare structures detected by HMI, namely their height above the limb, as well as the radiation intensity. These results are consistent with recent findings related to hydrogen Balmer continuum enhancements, which were clearly detected in disk flares by the IRIS near-ultraviolet spectrometer.

  11. Gender-related Changes in Dorsal Hand and Foot Vein Function Following 60 Days of Head Down Bed Rest

    Science.gov (United States)

    Westby, Christian M.; Phillips, Tiffany; Stenger, Michael B.; Platts, Steven H.

    2009-01-01

    It is well known that female astronauts are more likely to experience post-flight orthostatic hypotension and presyncope compared to male astronauts. It has been suggested that the disproportionally higher incidence of presyncope (83% of female vs. 20% male crewmembers) may be due to sex-related differences in vascular function between the upper and lower limbs. However, much of this evidence is specific to changes in resistance vessels. Given that more than 70% of the circulating blood volume resides in compliance vessels, it is conceivable that even small changes in venous function may contribute to post-flight orthostatic hypotension. In spite of this, little is currently known regarding the influence of microgravity exposure on venous function between males and females. PURPOSE: To determine the influence of 60 days of HDBR on dorsal foot and hand vein function between healthy males (M) and females (F). METHODS: Using 2-D ultrasound, dorsal hand and foot vein diameter responses to intravenous infusions phenylephrine (PE), acetylcholine (ACh), and nitroglycerine (NTG) were determined in 26 adults; 10 females (age:37 +/- 2 yr ) and 16 males (age:34 +/- 2 yr ). Changes in venous function were calculated as the difference between diameter at baseline and following each venoactive drug. Differences in venous function between limb and sexes across HDBR were determined using mixed-effects linear regression. RESULTS: In response to 60 days of HDBR, the change in venousconstrictor response to PE in the dorsal hand veins was not significantly different between M and F. Interestingly, the change in constrictor response in the dorsal foot veins (compared to pre HDBR) was approximately 30% greater in the F, whereas the constrictor response was approximately 45% less in the M (p=0.026). HDBR had no influence on the change in dilator response to ACh, or NTG between M and F and between vascular beds. CONCLUSION: These results demonstrate that 60 days of HDBR contributes to sex

  12. Analysis of 1,338 Patients with Acute Lower Limb Deep Venous Thrombosis (DVT) Supports the Inadequacy of the Term "Proximal DVT".

    Science.gov (United States)

    De Maeseneer, M G R; Bochanen, N; van Rooijen, G; Neglén, P

    2016-03-01

    For decades acute lower limb deep venous thrombosis (DVT) has been subdivided into distal DVT (isolated to the calf veins) and proximal DVT (extending above calf vein level). The aim of this study was to analyse the anatomical site and extent of thrombus in a large cohort of patients with acute DVT. A retrospective analysis of all patients aged >18 years, presenting with unilateral DVT according to duplex ultrasound investigation was performed at the University Hospital of Antwerp, Belgium (1994-2012). The anatomical site and extent of thrombus was registered and subdivided into five segments: calf veins (segment 1), popliteal vein (segment 2), femoral vein (segment 3), common femoral vein (segment 4), and iliac veins, with or without inferior vena cava (segment 5). The median age of the 1,338 patients (50% male) included was 62 years (range 18-98 years). Left sided DVT was predominant (57%). DVT was limited to one segment in 443 patients, of whom 370 had DVT isolated to the calf veins (28% of total cohort). In 968 patients with what was previously called "proximal DVT", the median number of affected segments was three (range 1-5 segments). In this group iliofemoral DVT (at least involving segment four and/or five) was present in 506 patients (38% of total cohort), whereas the remaining patients had femoropopliteal DVT (at least in segment two and/or three but not in four or five). Iliofemoral DVT without thrombus in segments one and two was present in 160 patients (12% of total cohort). This study illustrates the large diversity of thrombus distribution in patients previously described as having "proximal DVT". Therefore, this term should be abandoned and replaced with iliofemoral and femoropopliteal DVT. Patients with iliofemoral DVT (38%) could be considered for early clot removal; 12% of all patients with DVT would be ideal candidates for such intervention. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  13. Cross-limb interference during motor learning.

    Directory of Open Access Journals (Sweden)

    Benedikt Lauber

    Full Text Available It is well known that following skill learning, improvements in motor performance may transfer to the untrained contralateral limb. It is also well known that retention of a newly learned task A can be degraded when learning a competing task B that takes place directly after learning A. Here we investigate if this interference effect can also be observed in the limb contralateral to the trained one. Therefore, five different groups practiced a ballistic finger flexion task followed by an interfering visuomotor accuracy task with the same limb. Performance in the ballistic task was tested before the training, after the training and in an immediate retention test after the practice of the interference task for both the trained and the untrained hand. After training, subjects showed not only significant learning and interference effects for the trained limb but also for the contralateral untrained limb. Importantly, the interference effect in the untrained limb was dependent on the level of skill acquisition in the interfering motor task. These behavioural results of the untrained limb were accompanied by training specific changes in corticospinal excitability, which increased for the hemisphere ipsilateral to the trained hand following ballistic training and decreased during accuracy training of the ipsilateral hand. The results demonstrate that contralateral interference effects may occur, and that interference depends on the level of skill acquisition in the interfering motor task. This finding might be particularly relevant for rehabilitation.

  14. Large-Scale Description of Interacting One-Dimensional Bose Gases: Generalized Hydrodynamics Supersedes Conventional Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Dubail, Jérôme; Konik, Robert; Yoshimura, Takato

    2017-11-01

    The theory of generalized hydrodynamics (GHD) was recently developed as a new tool for the study of inhomogeneous time evolution in many-body interacting systems with infinitely many conserved charges. In this Letter, we show that it supersedes the widely used conventional hydrodynamics (CHD) of one-dimensional Bose gases. We illustrate this by studying "nonlinear sound waves" emanating from initial density accumulations in the Lieb-Liniger model. We show that, at zero temperature and in the absence of shocks, GHD reduces to CHD, thus for the first time justifying its use from purely hydrodynamic principles. We show that sharp profiles, which appear in finite times in CHD, immediately dissolve into a higher hierarchy of reductions of GHD, with no sustained shock. CHD thereon fails to capture the correct hydrodynamics. We establish the correct hydrodynamic equations, which are finite-dimensional reductions of GHD characterized by multiple, disjoint Fermi seas. We further verify that at nonzero temperature, CHD fails at all nonzero times. Finally, we numerically confirm the emergence of hydrodynamics at zero temperature by comparing its predictions with a full quantum simulation performed using the NRG-TSA-abacus algorithm. The analysis is performed in the full interaction range, and is not restricted to either weak- or strong-repulsion regimes.

  15. A review of supernumerary and absent limbs and digits of the upper limb.

    Science.gov (United States)

    Klaassen, Zachary; Choi, Monica; Musselman, Ruth; Eapen, Deborah; Tubbs, R Shane; Loukas, Marios

    2012-03-01

    For years people have been enamored by anomalies of the human limbs, particularly supernumerary and absent limbs and digits. Historically, there are a number of examples of such anomalies, including royal families of ancient Chaldea, tribes from Arabia, and examples from across nineteenth century Europe. The development of the upper limbs in a growing embryo is still being elucidated with the recent advent of homeobox genes, but researchers agree that upper limbs develop between stages 12-23 through a complex embryological process. Maternal thalidomide intake during limb development is known to cause limb reduction and subsequent amelia or phocomelia. Additionally, a number of clinical reports have illustrated different limb anomaly cases, with each situation unique in phenotype and developmental abnormality. Supernumerary and absent limbs and digits are not unique to humans, and a number of animal cases have also been reported. This review of the literature illustrates the historical, anatomical, and clinical aspects of supernumerary and absent limbs and digits for the upper limb.

  16. Incidence of upper limb venous thrombosis associated with peripherally inserted central catheters (PICC).

    Science.gov (United States)

    Abdullah, B J J; Mohammad, N; Sangkar, J V; Abd Aziz, Y F; Gan, G G; Goh, K Y; Benedict, I

    2005-07-01

    The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).

  17. The role of colour Doppler sonography in the diagnosis of lower limb Klippel–Trénaunay syndrome

    International Nuclear Information System (INIS)

    Qi, H.T.; Wang, X.M.; Zhang, X.D.; Zhang, M.H.; Li, C.M.; Bao, S.G.; Yuan, H.

    2013-01-01

    Aim: To investigate the accuracy of colour Doppler sonography as compared to phlebography in patients with Klippel-Trénaunay syndrome (KTS). Materials and methods: From September 2004 to May 2012, 59 consecutive patients seen in Shandong medical imaging research institute with a clinical suggestion of KTS were included. Thirty-four were female and 25 were male, with a mean age of 28.4 years. Colour Doppler sonography was used to assess the lower limb veins. The main sonographic criteria for a positive diagnosis were visualization of the lateral vein or sciatic vein, capillary haemangioma, and abnormality of the deep veins. These data were compared with phlebography findings. The κ statistic was used to determine the level of agreement. The sensitivity, specificity, positive and negative predictive values, and accuracy of colour Doppler sonography as a diagnostic test were assessed. Results: Colour Doppler sonography findings were positive in 21 of 59 patients with a clinical suggestion of KTS. The diagnosis was confirmed using phlebography in 22 patients. There were two false-positive results and one false-negative result by colour Doppler sonography. The κ-value was 0.892. Sensitivity, specificity, positive and negative predictive values, and accuracy for colour Doppler sonography were 95.4, 94.6, 91.3, 97.2, and 94.9%, respectively. Conclusion: Colour Doppler sonography is an accurate, reliable, and non-invasive investigation in the assessment of patients with suspected KTS

  18. Cetacean Swimming with Prosthetic Limbs

    Science.gov (United States)

    Bode-Oke, Ayodeji; Ren, Yan; Dong, Haibo; Fish, Frank

    2016-11-01

    During entanglement in fishing gear, dolphins can suffer abrasions and amputations of flukes and fins. As a result, if the dolphin survives the ordeal, swimming performance is altered. Current rehabilitation technques is the use of prosthesis to regain swimming ability. In this work, analyses are focused on two dolphins with locomotive impairment; Winter (currently living in Clearwater Marine Aquarium in Florida) and Fuji (lived in Okinawa Churaumi Aquarium in Japan). Fuji lost about 75% of its fluke surface to necrosis (death of cells) and Winter lost its tail due to amputation. Both dolphins are aided by prosthetic tails that mimic the shape of a real dolphin tail. Using 3D surface reconstruction techniques and a high fidelity Computational Fluid Dynamics (CFD) flow solver, we were able to elucidate the kinematics and hydrodynamics and fluke deformation of these swimmers to clarify the effectiveness of prostheses in helping the dolphins regain their swimming ability. Associated with the performance, we identified distinct features in the wake structures that can explain this gap in the performance compared to a healthy dolphin. This work was supported by ONR MURI Grant Number N00014-14-1-0533.

  19. Selective Thrombolysis in Acute Deep Vein Thrombosis: Evaluation of Adjuvant Therapy In Vivo

    International Nuclear Information System (INIS)

    Roy, Sumit; Brosstad, Frank; Sakariassen, Kjell S.

    1999-01-01

    Purpose: To evaluate in a porcine model of acute deep vein thrombosis (DVT) the efficacy of dalteparin and antithrombin with respect to heparin for local adjuvant therapy during selective thrombolysis, and the utility of nitroglycerin and iloprost as heparin supplements. Methods: DVT was induced in both hind limbs using a previously described technique (n = 20). Thirty minutes later, the animal was heparinized (2500 IU IV), and bilateral sequestrated thrombolysis was performed using 8 mg alteplase: both external iliac veins were endoluminally occluded with Swan-Ganz catheters, and a multi-sideport infusion wire coaxially introduced through each catheter and advanced into the ipsilateral popliteal vein. In the control limbs, tissue plasminogen activator (tPA) 8 mg was injected as 0.8-ml boluses at 3-min intervals for 2 hr as a 0.25-mg/ml solution containing heparin 50 IU/ml (n 20). On the contralateral side, heparin was substituted with either dalteparin 50 IU/ml (n = 5) or antithrombin 12.5 IU/ml (n = 5), or supplemented with either nitroglycerin 0.075 mg/ml (n = 5) or iloprost (150 ng/ml) (n = 5). Blood samples were taken at predetermined intervals to measure the activated partial thromboplastin time (aPTT), prothrombin time (PT), and fibrinogen concentration. At autopsy, the thrombus mass in the iliofemoral veins was measured, and the extent of residual thrombosis in the venous tributaries graded at four sites. Results: Bilateral thrombolysis was successfully completed in all animals. The median thrombus mass in the iliofemoral veins after thrombolysis was 0.48 g (range 0.06-1.58 g), 0.95 g (0.59-1.29 g), 0.74 g (0.52-0.96 g), and 0.29 g (0.0-0.77 g) for dalteparin, antithrombin, iloprost, and nitroglycerin respectively, as compared with 0.53 g (0.18-0.88 g) (p = 0.69), 0.97 g (0.46-1.15 g) (p = 0.69), 0.53 g (0.48-1.10 g) (p = 0.69), and 0.18 g (0.13-1.04 g) (p = 0.5) for the respective controls. Likewise, the severity of residual thrombosis in the venous

  20. Sciatica caused by a dilated epidural vein: MR findings

    International Nuclear Information System (INIS)

    Demaerel, P.; Petre, C.; Wilms, G.; Plets, C.

    1999-01-01

    We report the MR imaging findings in a 41-year-old woman presenting with sudden low back pain and sciatica. At surgery a dilated epidural vein was found compressing the nerve root. The MR findings may suggest the diagnosis. Magnetic resonance imaging of a dilated epidural vein or varix causing sciatica has not been reported until now. (orig.) (orig.)

  1. Endovascular management for significant iatrogenic portal vein bleeding.

    Science.gov (United States)

    Kim, Jong Woo; Shin, Ji Hoon; Park, Jonathan K; Yoon, Hyun-Ki; Ko, Gi-Young; Gwon, Dong Il; Kim, Jin Hyoung; Sung, Kyu-Bo

    2017-11-01

    Background Despite conservative treatment, hemorrhage from an intrahepatic branch of the portal vein can cause hemodynamic instability requiring urgent intervention. Purpose To retrospectively report the outcomes of hemodynamically significant portal vein bleeding after endovascular management. Material and Methods During a period of 15 years, four patients (2 men, 2 women; median age, 70.5 years) underwent angiography and embolization for iatrogenic portal vein bleeding. Causes of hemorrhage, angiographic findings, endovascular treatment, and complications were reported. Results Portal vein bleeding occurred after percutaneous liver biopsy (n = 2), percutaneous radiofrequency ablation (n = 1), and percutaneous cholecystostomy (n = 1). The median time interval between angiography and percutaneous procedure was 5 h (range, 4-240 h). Common hepatic angiograms including indirect mesenteric portograms showed active portal vein bleeding into the peritoneal cavity with (n = 1) or without (n = 2) an arterioportal (AP) fistula, and portal vein pseudoaneurysm alone with an AP fistula (n = 1). Successful transcatheter arterial embolization (n = 2) or percutaneous transhepatic portal vein embolization (n = 2) was performed. Embolic materials were n-butyl cyanoacrylate alone (n = 2) or in combination with gelatin sponge particles and coils (n = 2). There were no major treatment-related complications or patient mortality within 30 days. Conclusion Patients with symptomatic or life-threatening portal vein bleeding following liver-penetrating procedures can successfully be managed with embolization.

  2. A Modified Technique of Basilic Vein Transposition for Haemodialysis

    International Nuclear Information System (INIS)

    Chaudhary, F. A.; Parvez, Z.

    2014-01-01

    Objective: To modify the technique of basilic vein transposition for vascular accesss for haemodialysis aiming at better maturation rate, longer survival of fistula and lesser complications. Study Design: Case series. Place and Duration of Study: Shaikh Zayed Hospital and Omer Hospital, Lahore, from February 2008 to July 2011. Methodology: Patients referred for basilic vein transposition for haemodialysis vascular access were prospectively enrolled. The surgical technique included small tracking incisions, an extra 3 - 4 cm of vein length harvesting to avoid tension in the vein in its new course, an oval arteriotomy and a smooth curved pathway, away from vein harvesting incision to avoid entrapment of vein in the scar. Maturation rate, fistula survival and other complications were noted. Results: There was no immediate failure in 51 patients. The complications during follow-up period were infection and thrombosis, bleeding and non-development of basilic vein in 2 patients each; and false aneurysm formation in one. Four patients died during follow-up period. The maturation time was 4.9 A +- 1.1 weeks. The early patency rate was 92.2%, same at 6 months and 90.7% at 12 months. Conclusion: Arteriovenous fistula constructed with modified technique of basilic vein transposition is an acceptable and valid option of vascular access for haemodialysis. (author)

  3. A study of images of Projective Angles of pulmonary veins

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jue [Beijing Anzhen Hospital, Beijing (China); Zhaoqi, Zhang [Beijing Anzhen Hospital, Beijing (China)], E-mail: zhaoqi5000@vip.sohu.com; Yu Wei; Miao Cuilian; Yan Zixu; Zhao Yike [Beijing Anzhen Hospital, Beijing (China)

    2009-09-15

    Aims: In images of magnetic resonance and computed tomography (CT) there are visible angles between pulmonary veins and the coronary, transversal or sagittal section of body. In this study these angles are measured and defined as Projective Angles of pulmonary veins. Several possible influential factors and characters of distribution are studied and analyzed for a better understanding of this imaging anatomic character of pulmonary veins. And it could be the anatomic base of adjusting correctly the angle of the central X-ray of the angiography of pulmonary veins undergoing the catheter ablation of atrial fibrillation (AF). Method: Images of contrast enhanced magnetic resonance angiography (CEMRA) and contrast enhanced computer tomography (CECT) of the left atrium and pulmonary veins of 137 health objects and patients with atrial fibrillation (AF) are processed with the technique of post-processing, and Projective Angles to the coronary and transversal sections are measured and analyzed statistically. Result: Project Angles of pulmonary veins are one of real and steady imaging anatomic characteristics of pulmonary veins. The statistical distribution of variables is relatively concentrated, with a fairly good representation of average value. It is possible to improve the angle of the central X-ray according to the average value in the selective angiography of pulmonary veins undergoing the catheter ablation of AF.

  4. The Short Saphenous Vein: A Viable Alternative Conduit for ...

    African Journals Online (AJOL)

    This novel position allowed for two members of the surgical team to operate at the same time, thus ... along the ultrasound-marked vein positions similar to when harvesting the LSV. Once the veins were harvested and ... occlusion compared to LSV grafts utilized in the same procedure,[8] it was brought back to prominence ...

  5. A Tight Spot After Pulmonary Vein Catheter Ablation

    NARCIS (Netherlands)

    Amir, Rabia; Yeh, Lu; Montealegre-Gallegos, Mario; Saraf, Rabya; Matyal, Robina; Mahmood, Feroze

    2016-01-01

    A 52-YEAR-OLD woman with a history of embolic stroke due to paroxysmal atrial fibrillation was referred to the authors’ institution for epicardial surgical pulmonary vein isolation with left atrial appendage resection. The patient had 2 previous failed pulmonary vein catheter ablations. Dense

  6. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  7. Portal vein thrombosis after splenectomy for beta-thalassemia major

    International Nuclear Information System (INIS)

    Al-Hawsawi, Zakaria M.; Tarawah, Ahmed M.; Hassan, Ruhul Amin A.; Haouimi, Ammar S.

    2004-01-01

    Portal vein thrombosis is a recognized complication after splenectomy for beta-thalassemia major due to the chronic hypercoagulable state which has been recognized to exist in childhood thalassemia and contribute to thromboembolic events. We reporting one patient with beta-thalassemia major developed portal vein thrombosis following splenectomy. (author)

  8. Portal Vein Stenting for Portal Biliopathy with Jaundice

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, Dongho, E-mail: mesentery@naver.com; Park, Kwang Bo, E-mail: kbjh.park@samsung.com [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center (Korea, Republic of); Lim, Seong Joo [Konyang University, Department of Radiology, College of Medicine, Konyang University Hospital (Korea, Republic of); Hwang, Jin Ho [Hallym University Sacred Heart Hospital, Department of Radiology (Korea, Republic of); Sinn, Dong Hyun [Sungkyunkwan University School of Medicine, Department of Medicine, Samsung Medical Center (Korea, Republic of)

    2016-04-15

    Portal biliopathy refers to obstruction of the bile duct by dilated peri- or para-ductal collateral channels following the main portal vein occlusion from various causes. Surgical shunt operation or endoscopic treatment has been reported. Herein, we report a case of portal biliopathy that was successfully treated by interventional portal vein recanalization.

  9. Customizable Rehabilitation Lower Limb Exoskeleton System

    Directory of Open Access Journals (Sweden)

    Riaan Stopforth

    2012-10-01

    Full Text Available Disabled people require assistance with the motion of their lower limbs to improve rehabilitation. Exoskeletons used for lower limb rehabilitation are highly priced and are not affordable to the lowerincome sector of the population. This paper describes an exoskeleton lower limb system that was designed keeping in mind that the cost must be as low as possible. The forward kinematic system that is used must be a simplified model to decrease computational time, yet allow the exoskeleton to be adjustable according to the patient's leg dimensions.

  10. Radiography of syndactylous limbs of cattle

    International Nuclear Information System (INIS)

    Taura, Y.; Takeuchi, A.; Uchino, T.

    1985-01-01

    Fore and hind limbs of 4-month-old Holstein-Friesian cattle ♀ (No.I) and those of 1-month-old Holstein-Friesian×Japanese Black cattle ♀ (No.II) suffering from syndactyly were dissected by means of radiographic examinations. The details were reported as follows. 1. The phalanges of both fore and left hind limbs of No.II cattle were completely fused. But, all the phalanges of left fore limb and proximal phalanges of right fore limb in No.I and the distal phalanges of right hind limb in No.II were normal, the others being of partial synostosis. 2. The distal parforating canal was absent in the metacarpus and the right metatarsus in No.II cattle. Also, in No.II on the distal part of the metacarpal or metatarsal, bone vestiges were noted, not only of the fifth and second metacarpus or metatarsus, but also the mutually jointed phalanges. 3. In No.I cattle, the left fore limb and 4 proximal sesamoid bones and 2 distal sesamoid bones, but the right limb had 4 sesamoid bones and 0 distal one. In No.II cattle, the fore limbs had 2 proximal and 0 distal sesamoid bones, left hind limb had 3 proximal and 0 distal ones, right hind limb had 3 proximal and 1 distal ones. 4. The arteries accommodated the syndactylous deformities. The median and radial arteries were fixed to be descended on to the palmar side of the metacarpus and mutually anastomosed to form a deep palmar arch. arising from the deep palmar arch, two branches (palmar proper digital aa. III and IV) were terminated by the lateral and medial palmar surfaces of the digit, where some anastomosing arches were formed by them. The arteries of the hind limbs were also similar to those of the fore limbs. 5. In radiographic examinations of syndactyly (in No.II) after 7-month feeding, hoof and digital bones were noted to have been developed, but distal phalanges were destructed and left in suspicion of bad prognosis

  11. Smartphone supported upper limb prosthesis

    Directory of Open Access Journals (Sweden)

    Hepp D.

    2015-09-01

    Full Text Available State of the art upper limb prostheses offer up to six active DoFs (degrees of freedom and are controlled using different grip patterns. This low number of DoFs combined with a machine-human-interface which does not provide control over all DoFs separately result in a lack of usability for the patient. The aim of this novel upper limb prosthesis is both offering simplified control possibilities for changing grip patterns depending on the patients’ priorities and the improvement of grasp capability. Design development followed the design process requirements given by the European Medical Device Directive 93/42 ECC and was structured into the topics mechanics, software and drive technology. First user needs were identified by literature research and by patient feedback. Consequently, concepts were evaluated against technical and usability requirements. A first evaluation prototype with one active DoF per finger was manufactured. In a second step a test setup with two active DoF per finger was designed. The prototype is connected to an Android based smartphone application. Two main grip patterns can be preselected in the software application and afterwards changed and used by the EMG signal. Three different control algorithms can be selected: “all-day”, “fine” and “tired muscle”. Further parameters can be adjusted to customize the prosthesis to the patients’ needs. First patient feedback certified the prosthesis an improved level of handling compared to the existing devices. Using the two DoF test setup, the possibilities of finger control with a neural network are evaluated at the moment. In a first user feedback test, the smartphone based software application increased the device usability, e.g. the change within preselected grip patterns and the “tired muscle” algorithm. Although the overall software application was positively rated, the handling of the prosthesis itself needs to be proven within a patient study to be

  12. On the dragnosis of deep vein thrombosis

    International Nuclear Information System (INIS)

    Olsson, C.-G.

    1979-01-01

    Clinical and laboratory diagnostic methods were studied in 301 consecutive patients with suspected deep vein thrombosis (DVT). Unexpectedly, phlebography (the reference method) was found to cause DVT in estimated 48 % of patients without initial DVT. Using a new type of contrast medium, however, no thrombotic complications were found. - Neither clinical examination nor plethysmography were found to give reliable results. Using a modified technique for radioisotope detection, high sensitivity to DVT was found with the 125 I-fibrinogen uptake test (within 2 days) and a newly developed 99 Tcsup(m)-plasmin test (within one hour). Since both tests showed low specificity, they are reliable as screening tests to exclude DVT, but not as independent diagnostic methods. (author)

  13. Portal Vein Embolization: What Do We Know?

    Energy Technology Data Exchange (ETDEWEB)

    Denys, Alban, E-mail: Alban.Denys@chuv.ch [Centre Hospitalo Universitaire Vaudois, Department of Radiology and Interventional Radiology Unit (Switzerland); Prior, John [Centre Hospitalo Universitaire Vaudois, Department of Nuclear Medicine (Switzerland); Bize, Pierre; Duran, Rafael [Centre Hospitalo Universitaire Vaudois, Department of Radiology and Interventional Radiology Unit (Switzerland); Baere, Thierry De [Institut Gustave Roussy, Department of Interventional Radiology (France); Halkic, Nermin; Demartines, Nicolas [Centre Hospitalo Universitaire Vaudois, Department of Visceral Surgery (Switzerland)

    2012-10-15

    Portal vein embolization (PVE) has been developed to increase the size of the future remnant liver (FRL) left in place after major hepatectomy, thus reducing the risk of postoperative liver insufficiency. PVE consist in embolizing preoperatively portal branches of the segments that will be resected. Indication is based on preoperative measurements of the FRL by computed tomography and its ratio with either the theoretical liver volume or by direct measurement of the functional liver volume. After PVE, the volume and function of the FRL increases in 3 to 6 weeks, permitting extensive resections in patients otherwise contraindicated for liver resection. The PVE technique is variable from one center to another; however n-butyl-cyano-acrylate provides an interesting compromise between hypertrophy rate and procedure risk.

  14. Disastrous Portal Vein Embolization Turned into a Successful Intervention

    Energy Technology Data Exchange (ETDEWEB)

    Dobrocky, Tomas, E-mail: tomas.dobrocky@insel.ch [University of Bern, Department of Interventional, Pediatric and Diagnostic Radiology, Inselspital, University Hospital (Switzerland); Kettenbach, Joachim, E-mail: joachim.kettenbach@stpoelten.lknoe.at [Universitätsklinikum St. Pölten-Lilienfeld, Institute of Medical Radiology, Diagnostic, Intervention (Austria); Lopez-Benitez, Ruben, E-mail: Ruben.lopez@insel.ch; Kara, Levent, E-mail: levent.kara@insel.ch [University of Bern, Department of Interventional, Pediatric and Diagnostic Radiology, Inselspital, University Hospital (Switzerland)

    2015-10-15

    Portal vein embolization (PVE) may be performed before hemihepatectomy to increase the volume of future liver remnant (FLR) and to reduce the risk of postoperative liver insufficiency. We report the case of a 71-year-old patient with hilar cholangiocarcinoma undergoing PVE with access from the right portal vein using a mixture of n-butyl-2-cyanoacrylate and ethiodized oil. During the procedure, nontarget embolization of the left portal vein occurred. An aspiration maneuver of the polymerized plug failed; however, the embolus obstructing portal venous flow in the FLR was successfully relocated into the right portal vein while carefully bypassing the plug with a balloon catheter, inflating the balloon, and pulling the plug into the main right portal vein.

  15. Acute paraumbilical vein recanalization: an unusual complication of acute pancreatitis

    Directory of Open Access Journals (Sweden)

    R J Foster

    2015-04-01

    Full Text Available Acute pancreatitis is associated with a number of well-known complications and imaging findings. Spontaneous recanalization of the paraumbilical veins as a consequence of pancreatitis in a patient with an otherwise normal liver is, however, a rare entity. This case report depicts this unusual complication as a consequence of gallstone pancreatitis in a patient with a non-cirrhotic liver and no clinical or radiological evidence of portal hypertension. There was recanalization of the paraumbilical veins followed by thrombosis, which is believed to have propagated in a retrograde fashion into distal branches of the otherwise patent portal vein. A literature search for similar cases such as this has yielded no results. Although rare, clinicians and radiologists alike need to be aware of this finding. This case discussion highlights the embryology and anatomy of the paraumbilical veins, as well as discusses the management of paraumbilical and portal vein thrombosis.

  16. Mineral vein dynamics modelling (FRACS II)

    International Nuclear Information System (INIS)

    Urai, J.; Virgo, S.; Arndt, M.

    2016-08-01

    The Mineral Vein Dynamics Modeling group ''FRACS'' started out as a team of 7 research groups in its first phase and continued with a team of 5 research groups at the Universities of Aachen, Tuebingen, Karlsruhe, Mainz and Glasgow during its second phase ''FRACS 11''. The aim of the group was to develop an advanced understanding of the interplay between fracturing, fluid flow and fracture healing with a special emphasis on the comparison of field data and numerical models. Field areas comprised the Oman mountains in Oman (which where already studied in detail in the first phase), a siliciclastic sequence in the Internal Ligurian Units in Italy (closed to Sestri Levante) and cores of Zechstein carbonates from a Lean Gas reservoir in Northern Germany. Numerical models of fracturing, sealing and interaction with fluid that were developed in phase I where expanded in phase 11. They were used to model small scale fracture healing by crystal growth and the resulting influence on flow, medium scale fracture healing and its influence on successive fracturing and healing, as well as large scale dynamic fluid flow through opening and closing fractures and channels as a function of fluid overpressure. The numerical models were compared with structures in the field and we were able to identify first proxies for mechanical vein-hostrock properties and fluid overpressures versus tectonic stresses. Finally we propose a new classification of stylolites based on numerical models and observations in the Zechstein cores and continued to develop a new stress inversion tool to use stylolites to estimate depth of their formation.

  17. Mineral vein dynamics modelling (FRACS II)

    Energy Technology Data Exchange (ETDEWEB)

    Urai, J.; Virgo, S.; Arndt, M. [RWTH Aachen (Germany); and others

    2016-08-15

    The Mineral Vein Dynamics Modeling group ''FRACS'' started out as a team of 7 research groups in its first phase and continued with a team of 5 research groups at the Universities of Aachen, Tuebingen, Karlsruhe, Mainz and Glasgow during its second phase ''FRACS 11''. The aim of the group was to develop an advanced understanding of the interplay between fracturing, fluid flow and fracture healing with a special emphasis on the comparison of field data and numerical models. Field areas comprised the Oman mountains in Oman (which where already studied in detail in the first phase), a siliciclastic sequence in the Internal Ligurian Units in Italy (closed to Sestri Levante) and cores of Zechstein carbonates from a Lean Gas reservoir in Northern Germany. Numerical models of fracturing, sealing and interaction with fluid that were developed in phase I where expanded in phase 11. They were used to model small scale fracture healing by crystal growth and the resulting influence on flow, medium scale fracture healing and its influence on successive fracturing and healing, as well as large scale dynamic fluid flow through opening and closing fractures and channels as a function of fluid overpressure. The numerical models were compared with structures in the field and we were able to identify first proxies for mechanical vein-hostrock properties and fluid overpressures versus tectonic stresses. Finally we propose a new classification of stylolites based on numerical models and observations in the Zechstein cores and continued to develop a new stress inversion tool to use stylolites to estimate depth of their formation.

  18. Neurological sequelae from brachiocephalic vein stenosis.

    Science.gov (United States)

    Herzig, David W; Stemer, Andrew B; Bell, Randy S; Liu, Ai-Hsi; Armonda, Rocco A; Bank, William O

    2013-05-01

    Stenosis of central veins (brachiocephalic vein [BCV] and superior vena cava) occurs in 30% of hemodialysis patients, rarely producing intracranial pathology. The authors present the first cases of BCV stenosis causing perimesencephalic subarachnoid hemorrhage and myoclonic epilepsy. In the first case, a 73-year-old man on hemodialysis presented with headache and blurry vision, and was admitted with presumed idiopathic intracranial hypertension after negative CT studies and confirmatory lumbar puncture. The patient mildly improved until hospital Day 3, when he experienced a seizure; emergency CT scans showed perimesencephalic subarachnoid hemorrhage. Cerebral angiography failed to find any vascular abnormality, but demonstrated venous congestion. A fistulogram found left BCV occlusion with jugular reflux. The occlusion could not be reopened percutaneously and required open fistula ligation. Postoperatively, symptoms resolved and the patient remained intact at 7-month follow-up. In the second case, a 67-year-old woman on hemodialysis presented with right arm weakness and myoclonic jerks. Admission MRI revealed subcortical edema and a possible dural arteriovenous fistula. Cerebral angiography showed venous engorgement, but no vascular malformation. A fistulogram found left BCV stenosis with jugular reflux, which was immediately reversed with angioplasty and stent placement. Postprocedure the patient was seizure free, and her strength improved. Seven months later the patient presented in myoclonic status epilepticus, and a fistulogram revealed stent occlusion. Angioplasty successfully reopened the stent and she returned to baseline; she was seizure free at 4-month follow-up. Central venous stenosis is common with hemodialysis, but rarely presents with neurological findings. Prompt recognition and endovascular intervention can restore normal venous drainage and resolve symptoms.

  19. Puerperal ovarian vein thrombosis: two case reports.

    Science.gov (United States)

    Angelini, Marta; Barillari, Giovanni; Londero, Ambrogio P; Bertozzi, Serena; Bernardi, Sergio; Petri, Roberto; Driul, Lorenza; Marchesoni, Diego

    2013-02-01

    Ovarian vein thrombosis (OVT) is an uncommon but potentially serious complication in the early postpartum. Two case studies seem to prove the point: Case 1 A 24-year-old woman was transferred to our hospital with the chief complaint of abdominal pain radiating to the right thigh, vomit, diarrhea, and a slight pyrexia (37.6 °C rectal). Five days earlier, she had a spontaneous vaginal delivery after labor induction. The woman appeared slightly distressed because of pain; vital signs were found to be normal and the CRP elevated (129.9 mg/L). Abdominal examination was remarkable for tenderness by palpation in the right lower quadrant with no rebound tenderness or guarding. Pelvic examination was remarkable for mild right adnexal tenderness. Abdominal-pelvic computer tomography with contrast medium revealed a 2.5-cm OVT having extended into the inferior vena cava for 14 cm with a slight peripheral edema. The patient was treated with nadroparin 0.6 cc (5700 IU) bid and warfarin 5 mg since the attainment of the therapeutic INR range. Case 2 A 31-year-old twin-pregnant woman had an emergency cesarean section at 35 gestational weeks because of hypertension complicated by increased liver enzymes, diuresis contraction, and continuous lower back pain bilaterally radiating to the groins. One day after delivery, CT scan that was performed because of onward anemia showed a pelvic, perihepatic, and perisplenic blood effusion, and a 1-cm right OVT extended to the inferior vena cava below renal veins for 28 mm. She underwent exploratory laparotomy and blood transfusion, and because of respiratory insufficiency she was transferred to a second level center with ICU facility, where she was placed under a suprarenal inferior vena cava filter, and AngioJet Rheolytic Thrombectomy for acute pulmonary embolism was performed.

  20. Modelling hydrodynamic parameters to predict flow assisted corrosion

    International Nuclear Information System (INIS)

    Poulson, B.; Greenwell, B.; Chexal, B.; Horowitz, J.

    1992-01-01

    During the past 15 years, flow assisted corrosion has been a worldwide problem in the power generating industry. The phenomena is complex and depends on environment, material composition, and hydrodynamic factors. Recently, modeling of flow assisted corrosion has become a subject of great importance. A key part of this effort is modeling the hydrodynamic aspects of this issue. This paper examines which hydrodynamic parameter should be used to correlate the occurrence and rate of flow assisted corrosion with physically meaningful parameters, discusses ways of measuring the relevant hydrodynamic parameter, and describes how the hydrodynamic data is incorporated into the predictive model

  1. Contralateral Deep Vein Thrombosis after Iliac Vein Stent Placement in Patients with May-Thurner Syndrome.

    Science.gov (United States)

    Le, Trong Binh; Lee, Taeg Ki; Park, Keun-Myoung; Jeon, Yong Sun; Hong, Kee Chun; Cho, Soon Gu

    2018-04-25

    To investigate the incidence and potential causes of contralateral deep vein thrombosis (DVT) after common iliac vein (CIV) stent placement in patients with May-Thurner syndrome (MTS). Data of 111 patients (women: 73%) who had CIV stent implantation for symptomatic MTS at a single center were retrospectively analyzed. Mean patient age was 63.1 ± 15.2 years. Median follow-up was 36 months (range, 1-142 months). Stent location was determined by venogram and classified as extended to the inferior vena cava (IVC), covered the confluence, or confined to the iliac vein. Potential causes of contralateral DVT were presumed based on venographic findings. The relationship between stent location and contralateral DVT was analyzed. Ten patients (9%, men/women: 4/6) exhibited contralateral DVT at a median timing of 40 months (range, 6-98 months). Median age was 69 years (range, 42-85 years). Median follow-up was 73.5 months (range, 20-134 months). Potential causes were venous intimal hyperplasia (VIH) (n = 7), "jailing" (n = 2), and indeterminate (n = 1). All patients with VIH had previous CIV stents overextended to the IVC. Overextension of CIV stent was associated with contralateral DVT (P VIH should be considered a potential cause. Copyright © 2018 SIR. Published by Elsevier Inc. All rights reserved.

  2. Percutaneous closure of patent ductus arteriosus in interrupted inferior caval vein through femoral vein approach

    Directory of Open Access Journals (Sweden)

    Endale Tefera

    2014-01-01

    Full Text Available Percutaneous closure of the patent arterial duct in patients with interrupted inferior caval vein poses a technical challenge. A 12-year-old girl with a patent ductus arteriosus (PDA and interrupted inferior caval vein is described in this report. The diagnosis of interrupted inferior caval vein and azygos continuation was made in the catheterization laboratory. A catheter was advanced and snared in the descending aorta. An exchange wire was advanced through the catheter and snared in the descending aorta. Then, an Amplatzer TorqVue 2 delivery sheath was advanced over the wire from the venous side and again snared in the descending aorta. An Amplatzer duct occluder (ADO size 8/6 was advanced through the sheath while still holding the sheath with a snare. The device was opened. The sheath was then unsnared once the aortic disc was completely out. The sheath and the device were pulled back into the duct and the device was successfully implanted. The device was then released and it attained a stable position. An aortic angiogram was performed which showed complete occlusion.

  3. Percutaneous closure of patent ductus arteriosus in interrupted inferior caval vein through femoral vein approach

    International Nuclear Information System (INIS)

    Tefera, Endale; Bermudez-Cañete, Ramon

    2014-01-01

    Percutaneous closure of the patent arterial duct in patients with interrupted inferior caval vein poses a technical challenge. A 12-year-old girl with a patent ductus arteriosus (PDA) and interrupted inferior caval vein is described in this report. The diagnosis of interrupted inferior caval vein and azygos continuation was made in the catheterization laboratory. A catheter was advanced and snared in the descending aorta. An exchange wire was advanced through the catheter and snared in the descending aorta. Then, an Amplatzer TorqVue 2 delivery sheath was advanced over the wire from the venous side and again snared in the descending aorta. An Amplatzer duct occluder (ADO) size 8/6 was advanced through the sheath while still holding the sheath with a snare. The device was opened. The sheath was then unsnared once the aortic disc was completely out. The sheath and the device were pulled back into the duct and the device was successfully implanted. The device was then released and it attained a stable position. An aortic angiogram was performed which showed complete occlusion

  4. Endovenous mechanochemical ablation of great saphenous vein incompetence using the ClariVein device: a safety study

    NARCIS (Netherlands)

    Eekeren, R. van; Boersma, D.; Elias, S.; Holewijn, S.; Werson, D.A.; Vries, J.P. de; Reijnen, M.M.P.J.

    2011-01-01

    PURPOSE: To evaluate the feasibility and safety of endovenous mechanochemical ablation (MOCA) for the treatment of great saphenous vein (GSV) incompetence. METHODS: The newly developed ClariVein device uses a technique that combines mechanical endothelial damage using a rotating wire with the

  5. Treatment of hepatic encephalopathy by retrograde transcaval coil embolization of an ileal vein-to-right gonadal vein portosystemic shunt

    International Nuclear Information System (INIS)

    Nishie, Akihiro; Yoshimitsu, Kengo; Honda, Hiroshi; Kaneko, Kuniyuki; Kuroiwa, Toshiro; Fukuya, Tatsuro; Irie, Hiroyuki; Ninomiya, Toshiharu; Yoshimitsu, Takahiro; Hirakata, Hideki; Okuda, Seiya; Masuda, Kouji

    1997-01-01

    A 43-year-old non-cirrhotic woman suffered from encephalopathy caused by an extrahepatic portosystemic shunt between the ileal vein and inferior vena cava via the right gonadal vein. Percutaneous transcatheter embolization with stainless steel coils was performed by the retrograde systemic venous approach. Encephalopathy improved dramatically

  6. The benefit of limb cloud imaging for infrared limb sounding of tropospheric trace gases

    OpenAIRE

    G. Heinemann; P. Preusse; R. Spang; S. Adams

    2009-01-01

    Advances in detector technology enable a new generation of infrared limb sounders to measure 2-D images of the atmosphere. A proposed limb cloud imager (LCI) mode will detect clouds with a spatial resolution unprecedented for limb sounding. For the inference of temperature and trace gas distributions, detector pixels of the LCI have to be combined into super-pixels which provide the required signal-to-noise and information content for the retrievals. This study examines the extent to which tr...

  7. γ -phlebography of the upper limbs

    International Nuclear Information System (INIS)

    Jacolot, G.; Legendre, P.; Millour, L.; Barra, J.A.; Perramant, M.; Morin, P.P.

    1981-01-01

    γ-phlebography is an easy and repetitive exploration of deep venous thrombosis. This investigation becomes very useful for the upper limbs on account of the present frequency of iatrogenic thrombosis [fr

  8. A Cognitive Overview of Limb Apraxia.

    Science.gov (United States)

    Bartolo, Angela; Ham, Heidi Stieglitz

    2016-08-01

    Since the first studies on limb apraxia carried out by Hugo Liepmann more than a century ago, research interests focused on the way humans process manual gestures by assessing gesture production after patients suffered neurologic deficits. Recent reviews centered their attention on deficits in gesture imitation or processing object-related gestures, namely pantomimes and transitive gestures, thereby neglecting communicative/intransitive gestures. This review will attempt to reconcile limb apraxia in its entirety. To this end, the existing cognitive models of praxis processing that have been designed to account for the complexity of this disorder will be taken into account, with an attempt to integrate in these models the latest findings in the studies of limb apraxia, in particular on meaningful gestures. Finally, this overview questions the very nature of limb apraxia when other cognitive deficits are observed.

  9. Balloon-occluded retrograde transvenous obliteration of gastric varix draining via the left inferior phrenic vein into the left hepatic vein

    International Nuclear Information System (INIS)

    Ibukuro, Kenji; Mori, Koichi; Tsukiyama, Toshitaka; Inoue, Yoshihiro; Iwamoto, Yukako; Tagawa, Kazumi

    1999-01-01

    We encountered a patient with gastric varix draining not via the usual left suprarenal vein but via the left inferior phrenic vein joining the left hepatic vein. Transfemoral balloon-occluded retrograde transvenous obliteration (BRTO) of the varix was performed under balloon occlusion of the left inferior phrenic vein via the left hepatic vein and retrograde injection of the sclerosing agent (5% of ethanolamine oleate) into the gastric varix. Disappearance of the gastric varix was confirmed on endoscopic examination 2 months later.

  10. Supracardiac total anomalous pulmonary venous connection with a descending vertical vein.

    Science.gov (United States)

    Shah, Sejal; Singh, Mukesh; John, Colin; Maheshwari, Sunita

    2009-10-01

    The commonly used Darling classification for total anomalous pulmonary venous connection (TAPVC) consists of supracardiac, cardiac, infracardiac, and mixed types (Craig et al., Lab Invest 6:44-64, 1967). In supracardiac TAPVC, the common pulmonary vein drains superiorly into the left innominate vein, the superior vena cava, or the azygos vein by way of an ascending vertical vein. We describe a case of supracardiac TAPVC draining into the azygos vein atypically by way of a descending vertical vein.

  11. Goniometry and Limb Girth in Miniature Dachshunds

    OpenAIRE

    Thomovsky, Stephanie A.; Chen, Annie V.; Kiszonas, Alecia M.; Lutskas, Lori A.

    2016-01-01

    Purpose. To report the mean and median pelvic limb joint angles and girth measurements in miniature Dachshunds presenting with varying degrees of pelvic limb weakness secondary to thoracolumbar intervertebral disc extrusion. Methods. 15 miniature Dachshunds who presented to WSU-VTH for thoracolumbar disc extrusion. Dachshunds varied in neurologic status from ambulatory paraparetic to paraplegic at the time of measurements. Results. There were no significant differences in joint angles or girt...

  12. THE INFLUENCE OF LOWER LIMB MOVEMENT ON UPPER LIMB MOVEMENT SYMMETRY WHILE SWIMMING THE BREASTSTROKE

    Directory of Open Access Journals (Sweden)

    M. Jaszczak

    2011-09-01

    Full Text Available This study 1 examined the influence of lower limb movement on upper limb movement symmetry, 2 determined the part of the propulsion phase displaying the greatest hand movement asymmetry, 3 diagnosed the range of upper limb propulsion phase which is the most prone to the influence of the lower limbs while swimming the breaststroke. Twenty-four participants took part in two tests. Half of them performed an asymmetrical leg movement. The propulsion in the first test was generated by four limbs while in the second one only by the upper limbs. The pressure differentials exerted by the water on the back and on the palm of the right and left hand were measured. Then, the asymmetry coefficient of the hand movement was determined. No changes in the level of the asymmetry index in participants performing correct (symmetrical lower limb movement were observed. Incorrect (asymmetrical leg motion resulted in an increase of hand asymmetry. It could be concluded that lower limb faults neutralize upper limb performance when swimming on a rectilinear path. However, most asymmetrical arm performance should be identified with the conversion of propulsion into recovery. Nevertheless, its proneness to influence improper leg performance might be expected at the beginning of arm propulsion.

  13. Hydrodynamic Cavitation-Assisted Synthesis of Nanocalcite

    Directory of Open Access Journals (Sweden)

    Shirish H. Sonawane

    2010-01-01

    Full Text Available A systematic study was made on the synthesis of nanocalcite using a hydrodynamic cavitation reactor. The effects of various parameters such as diameter and geometry of orifice, CO2 flow rate, and Ca(OH2 concentration were investigated. It was observed that the orifice diameter and its geometry had significant effect on the carbonation process. The reaction rate was significantly faster than that observed in a conventional carbonation process. The particle size was significantly affected by the reactor geometry. The results showed that an orifice with 5 holes of 1 mm size resulted in the particle size reduction to 37 nm. The experimental investigation reveals that hydrodynamic cavitation may be more energy efficient.

  14. Application of hydrodynamics to heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Felsberger, Lukas

    2014-12-02

    The Bjorken model is a simple tool for making rough predictions of the hydrodynamic evolution of the thermalized matter created in a heavy ion collision. The advantage of the model clearly lies in its simplicity, rather than accuracy. As it is still used for making rough estimations 'by hand', in this thesis, I investigate in which cases the Bjorken model gives useful results and in which it is not recommended. For central collisions, I show which critical size the nuclei should have so that the Bjorken model can be applied. For non-central collisions, I demonstrate that using Glauber initial conditions combined with the Bjorken evolution, leads to reasonable results up to large impact parameters. Finally, I study the case of a non-ideal (viscous) description of the thermalized matter which leads to strongly differing results if first- or second-order hydrodynamics is applied.

  15. Hyperbolic metamaterial lens with hydrodynamic nonlocal response

    DEFF Research Database (Denmark)

    Yan, Wei; Mortensen, N. Asger; Wubs, Martijn

    2013-01-01

    We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves...... of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion curves numerically. As an application, we find that the focusing characteristics of a HMM lens...... in the local-response approximation and in the hydrodynamic Drude model can differ considerably. In particular, the optimal frequency for imaging in the nonlocal theory is blueshifted with respect to that in the local theory. Thus, to detect whether nonlocal response is at work in a hyperbolic metamaterial, we...

  16. Application of hydrodynamics to heavy ion collisions

    International Nuclear Information System (INIS)

    Felsberger, Lukas

    2014-01-01

    The Bjorken model is a simple tool for making rough predictions of the hydrodynamic evolution of the thermalized matter created in a heavy ion collision. The advantage of the model clearly lies in its simplicity, rather than accuracy. As it is still used for making rough estimations 'by hand', in this thesis, I investigate in which cases the Bjorken model gives useful results and in which it is not recommended. For central collisions, I show which critical size the nuclei should have so that the Bjorken model can be applied. For non-central collisions, I demonstrate that using Glauber initial conditions combined with the Bjorken evolution, leads to reasonable results up to large impact parameters. Finally, I study the case of a non-ideal (viscous) description of the thermalized matter which leads to strongly differing results if first- or second-order hydrodynamics is applied.

  17. Hydrodynamic interaction between bacteria and passive sphere

    Science.gov (United States)

    Zhang, Bokai; Ding, Yang; Xu, Xinliang

    2017-11-01

    Understanding hydrodynamic interaction between bacteria and passive sphere is important for identifying rheological properties of bacterial and colloidal suspension. Over the past few years, scientists mainly focused on bacterial influences on tracer particle diffusion or hydrodynamic capture of a bacteria around stationary boundary. Here, we use superposition of singularities and regularized method to study changes in bacterial swimming velocity and passive sphere diffusion, simultaneously. On this basis, we present a simple two-bead model that gives a unified interpretation of passive sphere diffusion and bacterial swimming. The model attributes both variation of passive sphere diffusion and changes of speed of bacteria to an effective mobility. Using the effective mobility of bacterial head and tail as an input function, the calculations are consistent with simulation results at a broad range of tracer diameters, incident angles and bacterial shapes.

  18. Granular Gases: Probing the Boundaries of Hydrodynamics

    International Nuclear Information System (INIS)

    Goldhirsch, I.

    1999-01-01

    The dissipative nature of the particle interactions in granular systems renders granular gases mesoscopic and bearing some similarities to regular gases in the ''continuum transition regime'' where shear rates and/or thermal gradients are very large). The following properties of granular gases support the above claim: (i). Mean free times are of the same order as macroscopic time scales (inverse shear rates); (ii). Mean free paths can be macroscopic and comparable to the system's dimensions; (iii). Typical flows are supersonic; (iv). Shear rates are typically ''large''; (v). Stress fields are scale (resolution) dependent; (vi). Burnett and super-Burnett corrections to both the constitutive relations and the boundary conditions are of importance; (vii). Single particle distribution functions can be far from Gaussian. It is concluded that while hydrodynamic descriptions of granular gases are relevant, they are probing the boundaries of applicability of hydrodynamics and perhaps slightly beyond

  19. The role of Weyl symmetry in hydrodynamics

    Science.gov (United States)

    Diles, Saulo

    2018-04-01

    This article is dedicated to the analysis of Weyl symmetry in the context of relativistic hydrodynamics. Here is discussed how this symmetry is properly implemented using the prescription of minimal coupling: ∂ → ∂ + ωA. It is shown that this prescription has no problem to deal with curvature since it gives the correct expressions for the commutator of covariant derivatives. In hydrodynamics, Weyl gauge connection emerges from the degrees of freedom of the fluid: it is a combination of the expansion and entropy gradient. The remaining degrees of freedom, shear, vorticity and the metric tensor, are see in this context as charged fields under the Weyl gauge connection. The gauge nature of the connection provides natural dynamics to it via equations of motion analogous to the Maxwell equations for electromagnetism. As a consequence, a charge for the Weyl connection is defined and the notion of local charge is analyzed generating the conservation law for the Weyl charge.

  20. Heat capacity of liquids: A hydrodynamic approach

    Directory of Open Access Journals (Sweden)

    T. Bryk

    2015-03-01

    Full Text Available We study autocorrelation functions of energy, heat and entropy densities obtained by molecular dynamics simulations of supercritical Ar and compare them with the predictions of the hydrodynamic theory. It is shown that the predicted by the hydrodynamic theory single-exponential shape of the entropy density autocorrelation functions is perfectly reproduced for small wave numbers by the molecular dynamics simulations and permits the calculation of the wavenumber-dependent specific heat at constant pressure. The estimated wavenumber-dependent specific heats at constant volume and pressure, Cv(k and Cp(k, are shown to be in the long-wavelength limit in good agreement with the macroscopic experimental values of Cv and Cp for the studied thermodynamic points of supercritical Ar.