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Sample records for surgical spacer placement

  1. [Interspinous spacers and disc herniation. Geomorphometric and clinical study of 71 cases treated by L4-L5 microdiscectomy associated to spacer placement].

    Science.gov (United States)

    Aso Escario, José; Aso Vizán, Alberto; Martínez Quiñones, José Vicente; Consolini, Fabian; Martín Gallego, Álvaro; Arregui Calvo, Ricardo

    2015-01-01

    A controversial indication of interspinous spacers is their use as a complement to discectomy. At the present time, there is no solid clinical evidence of effectiveness of that association, which might result from variability in spacer positioning, restricting its correct biomechanical actions. In this study our goal was to identify and analyse the variability in the placement of an interspinous spacer, and to investigate its relationship with the clinical results. We performed a retrospective study on X-ray films from 71 patients suffering from disc herniation in L4-L5 who underwent surgery in our hospital, consisting of: microdiscectomy and biomed interspinous spacer implantation. The geomorphometric techniques used to analyse the data were procrustes superimposition and principal components analysis. We compared the clinical results (using the Herron and Turner scale), segmental lordosis and surgical distraction with the geomorphometric parameters. Significant morphological variability was found in the implant position showing cephalo-caudal translation and clockwise-counterclockwise rotations. This variability did not correlate with clinical results. A relationship with anatomical features (lordosis) and additional surgical distraction was identified. A different morphology of implant-segment configuration was identified in cases with recurrence of disc herniation. Geometric morphometrics allowed identifying high variability in the final placement of interspinous spacers. Nevertheless, it seems not to be related to the clinical outcome, depending rather on the degree of lordosis and distraction. Some differences in segment-implant morphology were identified in cases with recurrences. To assess the effectiveness of spacers, larger studies including morphological and clinical variables are required. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  2. Renal failure after placement of an articulating, antibiotic impregnated polymethylmethacrlyate hip spacer

    Directory of Open Access Journals (Sweden)

    Robert P. Runner, MD

    2018-03-01

    Full Text Available A 58-year-old male presented with native joint septic arthritis of the hip and osteomyelitis. After treatment with an articulating antibiotic spacer, he developed acute renal failure requiring dialysis. He continued to have elevated serum tobramycin levels exclusively from the antibiotic spacer elution as no intravenous tobramycin was used. Subsequent explantation was required to correct his renal failure. Although renal failure after antibiotic impregnated cement placement is rare, the risk of this potential complication should be considered preoperatively and in the postoperative management of these patients.

  3. Antibiotic impregnated total femur spacers: a technical tip

    Directory of Open Access Journals (Sweden)

    Colin D. Canham, MD

    2018-03-01

    Full Text Available Simultaneous prosthetic joint infection of ipsilateral hip and knee arthroplasties is often accompanied by significant bone loss and presents a challenging reconstructive problem. Two-stage reconstruction is favored and requires the placement of a total femur spacer, which is not a commercially available device. We describe a surgical technique, reporting on 2 cases in which a customized total femur antibiotic impregnated spacer was created by combining an articulating knee spacer and an articulating hip spacer with a reinforced cement dowel construct connecting the 2 spacers. Custom total femoral spacers are useful in the management of infected femoral megaprostheses and cases with ipsilateral injected hip and knee arthroplasties and severe femoral bone loss. Keywords: total femur spacer, revision arthroplasty, total hip arthroplasty, total knee arthroplasty, prosthetic joint infection

  4. Immediate implant placement: surgical techniques for prevention and management of complications.

    Science.gov (United States)

    Al-Sabbagh, Mohanad; Kutkut, Ahmad

    2015-01-01

    Loss of soft and hard tissue is common after tooth extraction. Substantial resorption of alveolar bone compromises esthetics and may result in prosthetic and surgical limitations. Immediate implant placement at the time of tooth extraction is used to maintain alveolar ridge dimensions. Clinical studies support the successful outcome of immediate placement of dental implants in fresh extraction sockets; comparative clinical studies have found that implant survival rates after immediate placement are similar to those after delayed placement. This article addresses surgical techniques for immediate implant placement and the prevention and the management of complications associated with this procedure. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Static antibiotic spacers augmented by calcium sulphate impregnated beads in revision TKA: Surgical technique and review of literature.

    Science.gov (United States)

    Risitano, Salvatore; Sabatini, Luigi; Atzori, Francesco; Massè, Alessandro; Indelli, Pier Francesco

    2018-06-01

    Periprosthetic joint infection (PJI) is a serious complication in total knee arthroplasty (TKA) and represents one of the most common causes of revision. The challenge for surgeons treating an infected TKA is to quickly obtain an infection-free joint in order to re-implant, when possible, a new TKA. Recent literature confirms the role of local antibiotic-loaded beads as a strong bactericidal, allowing higher antibiotic elution when compared with antibiotic loaded spacers only. Unfortunately, classical Polymethylmethacrylate (PMMA) beads might allow bacteria adhesion, secondary development of antibiotic resistance and eventually surgical removal once antibiotics have eluted. This article describes a novel surgical technique using static, custom-made antibiotic loaded spacers augmented by calcium sulphate antibiotic-impregnated beads to improve the success rate of revision TKA in a setting of PJI. The use of calcium sulphate beads has several potential benefits, including a longer sustained local antibiotic release when compared with classical PMMA beads and, being resorbable, not requiring accessory surgical interventions.

  6. Preclinical evaluation of bioabsorbable polyglycolic acid spacer for particle therapy.

    Science.gov (United States)

    Akasaka, Hiroaki; Sasaki, Ryohei; Miyawaki, Daisuke; Mukumoto, Naritoshi; Sulaiman, Nor Shazrina Binti; Nagata, Masaaki; Yamada, Shigeru; Murakami, Masao; Demizu, Yusuke; Fukumoto, Takumi

    2014-12-01

    To evaluate the efficacy and safety of a polyglycolic acid (PGA) spacer through physical and animal experiments. The spacer was produced with surgical suture material made of PGA, forming a 3-dimensional nonwoven fabric. For evaluation or physical experiments, 150-MeV proton or 320-MeV carbon-ion beams were used to generate 60-mm width of spread-out Bragg peak. For animal experiments, the abdomens of C57BL/6 mice, with or without the inserted PGA spacers, were irradiated with 20 Gy of carbon-ion beam (290 MeV) using the spread-out Bragg peak. Body weight changes over time were scored, and radiation damage to the intestine was investigated using hematoxylin and eosin stain. Blood samples were also evaluated 24 days after the irradiation. Long-term thickness retention and safety were evaluated using crab-eating macaques. No chemical or structural changes after 100 Gy of proton or carbon-ion irradiation were observed in the PGA spacer. Water equivalency of the PGA spacer was equal to the water thickness under wet condition. During 24 days' observation after 20 Gy of carbon-ion irradiation, the body weights of mice with the PGA spacer were relatively unchanged, whereas significant weight loss was observed in those mice without the PGA spacer (P<.05). In mice with the PGA spacer, villus and crypt structure were preserved after irradiation. No inflammatory reactions or liver or renal dysfunctions due to placement of the PGA spacer were observed. In the abdomen of crab-eating macaques, thickness of the PGA spacer was maintained 8 weeks after placement. The absorbable PGA spacer had water-equivalent, bio-compatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to stop proton or carbon-ion beams and to separate normal tissues from the radiation field. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Accuracy Assessment of Immediate and Delayed Implant Placements Using CAD/CAM Surgical Guides.

    Science.gov (United States)

    Alzoubi, Fawaz; Massoomi, Nima; Nattestad, Anders

    2016-10-01

    The aim of this study is to assess the accuracy of immediately placed implants using Anatomage Invivo5 computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guides and compare the accuracy to delayed implant placement protocol. Patients who had implants placed using Anatomage Invivo5 CAD/CAM surgical guides during the period of 2012-2015 were evaluated retrospectively. Patients who received immediate implant placements and/or delayed implant placements replacing 1-2 teeth were included in this study. Pre- and postsurgical images were superimposed to evaluate deviations at the crest, apex, and angle. A total of 40 implants placed in 29 patients were included in this study. The overall mean deviations measured at the crest, apex, and angle were 0.86 mm, 1.25 mm, and 3.79°, respectively. The means for the immediate group deviations were: crest = 0.85 mm, apex = 1.10, and angle = 3.49°. The means for the delayed group deviations were: crest = 0.88 mm, apex = 1.59, and angle = 4.29°. No statistically significant difference was found at the crest and angle; however, there was a statistically significant difference between the immediate and delayed group at the apex, with the immediate group presenting more accurate placements at the apical point than the delayed group. CAD/CAM surgical guides can be reliable tools to accurately place implants immediately and/or in a delayed fashion. No statistically significant differences were found between the delayed and the immediate group at the crest and angle, however apical position was more accurate in the immediate group.

  8. One-piece implants: placement timing, surgical technique, loading protocol, and marginal bone loss.

    Science.gov (United States)

    Prithviraj, D R; Gupta, Vikas; Muley, Ninad; Sandhu, Pushpinder

    2013-04-01

    Osseointegration being an accepted and well-documented concept, attention is now directed towards simplification of the mechanical design of implants and towards achieving biomechanical success. The aim of this literature review is to provide an overview of the one-piece implant, with its advantages and disadvantages over a conventional two-piece implant. The PubMed database was searched in the English language using the keywords one-piece implant, single-piece implant, single-stage implant surgery, and two-piece implant. Articles were selected on the basis of whether they had sufficient information related to placement timing, surgical procedure used, loading protocol, follow-up periods, marginal bone loss, and implant success rates of one-piece implants. For inclusion, a study group must have had a minimum of 30 one-piece implants followed for at least 1 year. Nineteen articles were subjected to the selection criteria. Out of 19 clinical trials only 11 met the selection criteria. Five parameters were taken into consideration for studying one-piece implants: placement timing, surgical technique, loading protocol, marginal bone loss, and implant survival rate. The data from the identified studies were tabulated according to these parameters and discussed. Delayed placement of one-piece implants is more commonly practiced than extraction and immediate placement. Most surgeons prefer surgeries using flaps as compared to flapless surgeries, and in most cases, one-piece implants were loaded immediately. Limited literature reveals both positive and negative results regarding the effect of a one-piece implant system on surrounding hard and soft tissues. © 2012 by the American College of Prosthodontists.

  9. Preclinical Evaluation of Bioabsorbable Polyglycolic Acid Spacer for Particle Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, Hiroaki [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Sasaki, Ryohei, E-mail: rsasaki@med.kobe-u.ac.jp [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Miyawaki, Daisuke; Mukumoto, Naritoshi; Sulaiman, Nor Shazrina Binti [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Nagata, Masaaki [Division of Gastroenterology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Yamada, Shigeru [Research Center Hospital, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Murakami, Masao [Radiation Oncology Center, Dokkyo Medical University, Tochigi (Japan); Demizu, Yusuke [Department of Radiology, Hyogo Ion Beam Medical Center, Hyogo (Japan); Fukumoto, Takumi [Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Hyogo Japan (Japan)

    2014-12-01

    Purpose: To evaluate the efficacy and safety of a polyglycolic acid (PGA) spacer through physical and animal experiments. Methods and Materials: The spacer was produced with surgical suture material made of PGA, forming a 3-dimensional nonwoven fabric. For evaluation or physical experiments, 150-MeV proton or 320-MeV carbon-ion beams were used to generate 60-mm width of spread-out Bragg peak. For animal experiments, the abdomens of C57BL/6 mice, with or without the inserted PGA spacers, were irradiated with 20 Gy of carbon-ion beam (290 MeV) using the spread-out Bragg peak. Body weight changes over time were scored, and radiation damage to the intestine was investigated using hematoxylin and eosin stain. Blood samples were also evaluated 24 days after the irradiation. Long-term thickness retention and safety were evaluated using crab-eating macaques. Results: No chemical or structural changes after 100 Gy of proton or carbon-ion irradiation were observed in the PGA spacer. Water equivalency of the PGA spacer was equal to the water thickness under wet condition. During 24 days' observation after 20 Gy of carbon-ion irradiation, the body weights of mice with the PGA spacer were relatively unchanged, whereas significant weight loss was observed in those mice without the PGA spacer (P<.05). In mice with the PGA spacer, villus and crypt structure were preserved after irradiation. No inflammatory reactions or liver or renal dysfunctions due to placement of the PGA spacer were observed. In the abdomen of crab-eating macaques, thickness of the PGA spacer was maintained 8 weeks after placement. Conclusions: The absorbable PGA spacer had water-equivalent, bio-compatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to stop proton or carbon-ion beams and to separate normal tissues from the radiation field.

  10. Preclinical Evaluation of Bioabsorbable Polyglycolic Acid Spacer for Particle Therapy

    International Nuclear Information System (INIS)

    Akasaka, Hiroaki; Sasaki, Ryohei; Miyawaki, Daisuke; Mukumoto, Naritoshi; Sulaiman, Nor Shazrina Binti; Nagata, Masaaki; Yamada, Shigeru; Murakami, Masao; Demizu, Yusuke; Fukumoto, Takumi

    2014-01-01

    Purpose: To evaluate the efficacy and safety of a polyglycolic acid (PGA) spacer through physical and animal experiments. Methods and Materials: The spacer was produced with surgical suture material made of PGA, forming a 3-dimensional nonwoven fabric. For evaluation or physical experiments, 150-MeV proton or 320-MeV carbon-ion beams were used to generate 60-mm width of spread-out Bragg peak. For animal experiments, the abdomens of C57BL/6 mice, with or without the inserted PGA spacers, were irradiated with 20 Gy of carbon-ion beam (290 MeV) using the spread-out Bragg peak. Body weight changes over time were scored, and radiation damage to the intestine was investigated using hematoxylin and eosin stain. Blood samples were also evaluated 24 days after the irradiation. Long-term thickness retention and safety were evaluated using crab-eating macaques. Results: No chemical or structural changes after 100 Gy of proton or carbon-ion irradiation were observed in the PGA spacer. Water equivalency of the PGA spacer was equal to the water thickness under wet condition. During 24 days' observation after 20 Gy of carbon-ion irradiation, the body weights of mice with the PGA spacer were relatively unchanged, whereas significant weight loss was observed in those mice without the PGA spacer (P<.05). In mice with the PGA spacer, villus and crypt structure were preserved after irradiation. No inflammatory reactions or liver or renal dysfunctions due to placement of the PGA spacer were observed. In the abdomen of crab-eating macaques, thickness of the PGA spacer was maintained 8 weeks after placement. Conclusions: The absorbable PGA spacer had water-equivalent, bio-compatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to stop proton or carbon-ion beams and to separate normal tissues from the radiation field

  11. Use of the Toric Surgical Marker to Aid in Intraoperative Plaque Placement for the USC Eye Physics Plaques to Treat Uveal Melanoma: A New Surgical Technique.

    Science.gov (United States)

    Berry, Jesse L; Kim, Jonathan W; Jennelle, Richard; Astrahan, Melvin

    2015-09-01

    To describe a new surgical technique for intraoperative placement of Eye Physics (EP) plaques for uveal melanoma using a toric marker. A toric marker is designed for cataract surgery to align the axis of astigmatism; its use was modified in this protocol to mark the axis of suture coordinates as calculated by Plaque Simulator (PS) software. The toric marker can be used to localize suture coordinates, in degrees, during intraoperative plaque placement. Linear marking using the toric marker decreases potential inaccuracies associated with the surgeon estimating 'clock-hours' by dot placement. Use of the toric marker aided surgical placement of EP plaques. The EP planning protocol is now designed to display the suture coordinates either by clock-hours or degrees, per surgeon preference. Future research is necessary to determine whether routine use of the toric marker improves operative efficiency. [Ophthalmic Surg Lasers Imaging Retina. 2015;46:866-870.]. Copyright 2015, SLACK Incorporated.

  12. [NIC as a tool for assessing competences of nursing students in clinical placement at surgical units].

    Science.gov (United States)

    Celma Vicente, Matilde; Ajuria-Imaz, Eloisa; Lopez-Morales, Manuel; Fernandez-Marín, Pilar; Menor-Castro, Alicia; Cano-Caballero Galvez, Maria Dolores

    2015-01-01

    This paper shows the utility of a NIC standardized language to assess the extent of nursing student skills at Practicum in surgical units To identify the nursing interventions classification (NIC) that students can learn to perform in surgical units. To determine the level of difficulty in learning interventions, depending on which week of rotation in clinical placement the student is. Qualitative study using Delphi consensus technique, involving nurses with teaching experience who work in hospital surgical units, where students undertake the Practicum. The results were triangulated through a questionnaire to tutors about the degree of conformity. A consensus was reached about the interventions that students can achieve in surgical units and the frequency in which they can be performed. The level of difficulty of each intervention, and the amount of weeks of practice that students need to reach the expected level of competence was also determined. The results should enable us to design better rotations matched to student needs. Knowing the frequency of each intervention that is performed in each unit determines the chances of learning it, as well as the indicators for its assessment. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  13. Effect of surgical guide design and surgeon's experience on the accuracy of implant placement.

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    Hinckfuss, Simon; Conrad, Heather J; Lin, Lianshan; Lunos, Scott; Seong, Wook-Jin

    2012-08-01

    Implant position is a key determinant of esthetic and functional success. Achieving the goal of ideal implant position may be affected by case selection, prosthodontically driven treatment planning, site preparation, surgeon's experience and use of a surgical guide. The combined effect of surgical guide design, surgeon's experience, and size of the edentulous area on the accuracy of implant placement was evaluated in a simulated clinical setting. Twenty-one volunteers were recruited to participate in the study. They were divided evenly into 3 groups (novice, intermediate, and experienced). Each surgeon placed implants in single and double sites using 4 different surgical guide designs (no guide, tube, channel, and guided) and written instructions describing the ideal implant positions. A definitive typodont was constructed that had 3 implants in prosthetically determined ideal positions of single and double sites. The position and angulation of implants placed by the surgeons in the duplicate typodonts was measured using a computerized coordinate measuring machine and compared to the definitive typodont. The mean absolute positional error for all guides was 0.273, 0.340, 0.197 mm in mesial-distal, buccal-lingual, vertical positions, respectively, with an overall range of 0.00 to 1.81 mm. The mean absolute angle error for all guides was 1.61° and 2.39° in the mesial-distal and buccal-lingual angulations, respectively, with an overall range of 0.01° to 9.7°. Surgical guide design had a statistically significant effect on the accuracy of implant placement regardless of the surgeon's experience level. Experienced surgeons had significantly less error in buccal-lingual angulation. The size of the edentulous sites was found to affect both implant angle and position significantly. The magnitude of error in position and angulation caused by surgical guide design, surgeon's experience, and site size reported in this study are possibly not large enough to be clinically

  14. A COMPARATIVE ANALYSIS OF PERCUTANEOUS AND OPEN SURGICAL TECHNIQUESFOR PERITONEAL CATHETER PLACEMENT.

    LENUS (Irish Health Repository)

    Medani, Samar

    2012-05-01

    BACKGROUND: Peritoneal dialysis (PD) is the preferred available option of renal replacement therapy for a significant number of end-stage kidney disease patients. A major limiting factor to the successful continuation of PD is the long-term viability of the PD catheter (PDC). Bedside percutaneous placement of the PDC is not commonly practiced despite published data encouraging use of this technique. Its advantages include faster recovery and avoidance of general anesthesia.♢ METHODS: We carried out a retrospective analysis of the outcomes of 313 PDC insertions at our center, comparing all percutaneous PDC insertions between July 1998 and April 2010 (group P, n = 151) with all surgical PDC insertions between January 2003 and April 2010 (group S, n = 162).♢ RESULTS: Compared with group P patients, significantly more group S patients had undergone previous abdominal surgery or PDC insertion (41.8% vs 9.3% and 33.3% vs 3.3% respectively, p = 0.00). More exit-site leaks occurred in group P than in group S (20.5% vs 6.8%, p = 0.002). The overall incidence of peritonitis was higher in group S than in group P (1 episode in 19 catheter-months vs 1 episode in 26 catheter-months, p = 0.017), but the groups showed no significant difference in the peritonitis rate within 1 month of catheter insertion (5% in group P vs 7.4% in group S, p =0.4) or in poor initial drainage or secondary drainage failure (9.9% vs 11.7%, p = 0.1, and 7.9% vs 12.3%, p = 0.38, for groups P and S respectively). Technical survival at 3 months was significantly better for group P than for group S (86.6% vs 77%, p = 0.037); at 12 months, it was 77.7% and 68.7% respectively (p = 0.126). No life-threatening complications attributable to the insertion of the PDC occurred in either group.♢ CONCLUSIONS: Our analysis demonstrates further encouraging outcomes of percutaneous PDC placement compared with open surgical placement. However, the members of the percutaneous insertion group were primarily a

  15. Bone Reduction to Facilitate Immediate Implant Placement and Loading Using CAD/CAM Surgical Guides for Patients With Terminal Dentition.

    Science.gov (United States)

    Alzoubi, Fawaz; Massoomi, Nima; Nattestad, Anders

    2016-10-01

    The aim of this study is to present a method, using 3 computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guides, to accurately obtain the desired bone reduction followed by immediate implant placements and loading for patients diagnosed with terminal dentition. Patients who had bone reduction, implants placed, and immediate loading using Anatomage Invivo 5 CAD/CAM surgical guides between the period 2013 and 2015 were evaluated retrospectively. Patients diagnosed with terminal dentition and treated using the "3-guide technique" were identified. Pre- and postsurgical images were superimposed to evaluate deviations of the bone reduction and deviations at the crest, apex, and angle of implants placed. Twenty-six implants placed in 5 patients were included in this study. The overall deviation means measured for bone reduction was 1.98 mm. The overall deviation means measured for implant placement at the crest, apex, and angle were 1.43 mm, 1.90 mm, and 4.14°, respectively. The CAD/CAM surgical guide fabrication is an emerging tool that may facilitate the surgical process and aid in safe and predictable execution of bone reduction and immediate implant placement. Using 3 CAD/CAM surgical guides, a method is presented to obtain the desired bone reduction followed by immediate implant placement and loading for patients diagnosed with terminal dentition. This method may improve guide stability for patients with terminal dentition undergoing complete implant-supported treatment by taking advantage of the teeth to be extracted.

  16. Placement of fin type dental implant in three different surgical situations of alveolar bone

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    Coen Pramono D

    2007-03-01

    Full Text Available Three different dental implant placements according to surgical implant bed situations were observed in its bone integration 3 months after dental implant insertion. This observation was done on implant system which has plateau or fin system. Elf implants were placed in the upper jaw in two patients. In case one, two implants were inserted immediately after tooth extraction, and the other six implants were placed in the alveolar crest regions in delayed implantation or in which the teeth had been extracted over 6 months of period. In case two, three implants were inserted in the post trauma region in the anterior maxilla, which the labial plate had been lost and reconstructed with bone grafting procedure using a mixture of alloplastic and autogenous bones. The alveolar reconstruction was needed to be performed due to only thin alveolar crest width was left intact. All of those implants observed showed in good integration.

  17. Bedside intravascular ultrasound-guided inferior vena cava filter placement in medical-surgical intensive care critically-ill patients

    Directory of Open Access Journals (Sweden)

    Mohammad A. Abusedera

    2015-09-01

    Conclusions: Bedside IVUS-guided filter placement in medical-surgical critically ill patient in intensive care unit is a feasible, safe and reliable technique for IVC interruption. IVUS may be the most appropriate tool to guide filter insertion in obese patient.

  18. Fuel spacer

    International Nuclear Information System (INIS)

    Nishida, Koji; Yokomizo, Osamu; Kanazawa, Toru; Kashiwai, Shin-ichi; Orii, Akihito.

    1992-01-01

    The present invention concerns a fuel spacer for a fuel assembly of a BWR type reactor and a PTR type reactor. Springs each having a vane are disposed on the side surface of a circular cell which supports a fuel rods. A vortex streams having a vertical component are formed by the vanes in the flowing direction of a flowing channel between adjacent cylindrical cells. Liquid droplets carried by streams are deposited on liquid membrane streams flowing along the fuel rod at the downstream of the spacer by the vortex streams. In view of the above, the liquid droplets can be deposited to the fuel rod without increasing the amount of metal of the spacer. Accordingly, the thermal margin of the fuel assembly can be improved without losing neutron economy. (I.N.)

  19. Potential and challenges for learning during acute medical/surgical placement for intellectual disability, mental health and midwifery students.

    Science.gov (United States)

    Mc Carthy, Jane; Graham, Margaret M; Tuohy, Dympna; O'Brien, Brid; Fahy, Anne; Hennessy, Therese; O'Sullivan, Deirdre; Markey, Kathleen

    2018-01-01

    In Ireland nursing and midwifery degree programmes involve four pathways to registration. Three of which, intellectual disability and mental health nursing and midwifery require students to undertake acute medical/surgical placements offering learning opportunities caring for patients with complex needs in settings beyond their core discipline. This paper focuses on findings from a descriptive qualitative study exploring intellectual disability and mental health nursing and midwifery students experiences of such placements. Data analysis identified three themes: Getting ready, Navigating the way and Getting through. Feelings of stress and uncertainty are described by participants when moving from familiarity within a chosen discipline to an unfamiliar environment. Findings have influenced specific placement structures with local health service partners. While our study focuses on an Irish context, findings have relevance for student education in other jurisdictions. Enhancing preparation and support for students undertaking unfamiliar placements needs to be a constant endeavour. Such foundations will foster valuable experiences where students can feel part of a team, gain confidence, enhance skills and transfer meaningful learning to their core practice discipline. Further research is needed to explore the views of preceptors, ward managers and Clinical Placement Coordinators. Copyright © 2017. Published by Elsevier Ltd.

  20. Outcomes and Direct Costs of Inferior Vena Cava Filter Placement and Retrieval within the IR and Surgical Settings.

    Science.gov (United States)

    Makary, Mina S; Kapke, Jordan; Yildiz, Vedat; Pan, Xueliang; Dowell, Joshua D

    2018-02-01

    To compare the outcomes and costs of inferior vena cava (IVC) filter placement and retrieval in the interventional radiology (IR) and surgical departments at a tertiary-care center. Retrospective review was performed of 142 sequential outpatient IVC filter placements and 244 retrievals performed in the IR suite and operating room (OR) from 2013 to 2016. Patient demographic data, procedural characteristics, outcomes, and direct costs were compared between cohorts. Technical success rates of 100% were achieved for both IR and OR filter placements, and 98% of filters were successfully retrieved by IR means, compared with 83% in the OR (P IR and OR filter insertions, but IR retrievals required half the fluoroscopy time, with an average of 9 minutes vs 18 minutes in the OR (P = .02). There was no significant difference between cohorts in the incidences of complications for filter retrievals, but more postprocedural complications were observed for OR placements (8%) vs IR placements (1%; P = .05). The most severe complication occurred during an OR filter retrieval, resulting in entanglement of the snare device and conversion to an emergent open filter removal by vascular surgery. Direct costs were approximately 20% higher for OR vs IR IVC filter placements ($2,246 vs $2,671; P = .01). Filter placements are equally successfully performed in IR and OR settings, but OR patients experienced significantly higher postprocedural complication rates and incurred higher costs. In contrast, higher technical success rates and shorter fluoroscopy times were observed for IR filter retrievals compared with those performed in the OR. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  1. Chronic post-surgical pain following the placement of dental implants in the maxilla: A case series.

    Science.gov (United States)

    Devine, Maria; Taylor, Sarah; Renton, Tara

    To present ten cases of chronic post-surgical neuropathic pain (CPSP) arising after placement of maxillary dental implants, in order to raise awareness of this potential complication of treatment. Data collected from the case notes of consecutive patients presenting to the orofacial pain clinic, with neuropathic pain arising after placement of maxillary dental implants. Nine out of 10 patients were female, with an average age 55.4 years. Six patients had a significant medical history (depression, peripheral neuropathic pain, irritable bowel syndrome and fibromyalgia). Six patients had single implants placed, four had multiple implants. Four patients experienced pain during implant placement. Onset of pain was immediate in nine patients. Pain intensity (visual analogue scale) ranged from 2 to 9 (average 5.6). Pain was constant in all patients. Exacerbating factors included stress, tiredness, low mood and cold weather. Implants were removed in two patients however pain did not resolve. Pain management was complex; including medication (anti-epileptics and tricyclic antidepressants), Botox injections and cognitive behavioural therapy, however pain did not completely resolve in nine cases. Persistent pain after dental implant placement may occur with no apparent organic cause and without any neurosensory deficits. Practitioners must be aware of chronic post-surgical neuropathic pain as a possible complication of implant placement, particularly in patients with a significant medical history. Consideration should be given as to whether these patients are suitable for implant rehabilitation. Patients reporting very severe and prolonged postoperative pain following implant surgery should be considered at risk of CPSP and referred to a specialist in orofacial pain.

  2. Inferior Alveolar Nerve Lateralization and Transposition for Dental Implant Placement. Part I: a Systematic Review of Surgical Techniques

    Directory of Open Access Journals (Sweden)

    Boris Abayev

    2015-03-01

    Full Text Available Objectives: The purpose of this first part of a two-part series was to review the literature concerning the indications, contraindications, advantages, disadvantages and surgical techniques of the lateralization and transposition of the inferior alveolar nerve, followed by the placement of an implant in an edentulous atrophic posterior mandible. Material and Methods: A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed and PMC database, academic sites and books. The articles were searched from January 1997 to July 2014 and comprised English-language articles that included adult patients between 18 and 80 years old with minimal residual bone above the mandibular canal who had undergone inferior alveolar nerve (IAN repositioning with a minimum 6 months of follow-up. Results: A total of 16 studies were included in this review. Nine were related to IAN transposition, 4 to IAN lateralization and 3 to both transposition and lateralization. Implant treatment results and complications were presented. Conclusions: Inferior alveolar nerve lateralization and transposition in combination with the installation of dental implants is sometimes the only possible procedure to help patients to obtain a fixed prosthesis, in edentulous atrophic posterior mandibles. With careful pre-operative surgical and prosthetic planning, imaging, and extremely precise surgical technique, this procedure can be successfully used for implant placement in edentulous posterior mandibular segments.

  3. Comparison of cardiopulmonary responses during sedation with epidural and local anesthesia for laparoscopic-assisted jejunostomy feeding tube placement with cardiopulmonary responses during general anesthesia for laparoscopic-assisted or open surgical jejunostomy feeding tube placement in healthy dogs.

    Science.gov (United States)

    Hewitt, Saundra A; Brisson, Brigitte A; Sinclair, Melissa D; Sears, William C

    2007-04-01

    To evaluate the use of laparoscopic-assisted jejunostomy feeding tube (J-tube) placement in healthy dogs under sedation with epidural and local anesthesia and compare cardiopulmonary responses during this epidural anesthetic protocol with cardiopulmonary responses during general anesthesia for laparoscopic-assisted or open surgical J-tube placement. 15 healthy mixed-breed dogs. Dogs were randomly assigned to receive open surgical J-tube placement under general anesthesia (n = 5 dogs; group 1), laparoscopic-assisted J-tube placement under general anesthesia (5; group 2), or laparoscopic-assisted J-tube placement under sedation with epidural and local anesthesia (5; group 3). Cardiopulmonary responses were measured at baseline (time 0), every 5 minutes during the procedure (times 5 to 30 minutes), and after the procedure (after desufflation [groups 2 and 3] or at the start of abdominal closure [group 1]). Stroke volume, cardiac index, and O(2) delivery were calculated. All group 3 dogs tolerated laparoscopic-assisted J-tube placement under sedation with epidural and local anesthesia. Comparison of cardiovascular parameters revealed a significantly higher cardiac index, mean arterial pressure, and O(2) delivery in group 3 dogs, compared with group 1 and 2 dogs. Minimal differences in hemodynamic parameters were found between groups undergoing laparoscopic-assisted and open surgical J-tube placement under general anesthesia (ie, groups 1 and 2); these differences were not considered to be clinically important in healthy research dogs. Sedation with epidural and local anesthesia provided satisfactory conditions for laparoscopic-assisted J-tube placement in healthy dogs; this anesthetic protocol caused less cardiopulmonary depression than general anesthesia and may represent a better choice for J-tube placement in critically ill patients.

  4. Simplified Surgical Placement of Tenckhoff Catheter under Local Anesthesia: The Dammam Central Hospital Experience

    Directory of Open Access Journals (Sweden)

    Youmbissi T

    2001-01-01

    Full Text Available Many methods are used for the placement of Tenckhoff catheters. Eighteen consecutive Tenckhoff catheters were placed under local anesthesia through a mini laparotomy with a reduced operating team. There were only three total catheter failures. Complications were infrequent and operating time was less than one hour on average. This simple procedure should be a part of the training program of all junior surgeons and nephrologists.

  5. Accuracy of targeted wire guided tube thoracostomy in comparison to classical surgical chest tube placement - A clinical study.

    Science.gov (United States)

    Protic, Alen; Barkovic, Igor; Ivancic, Aldo; Kricka, Ozren; Zuvic-Butorac, Marta; Sustic, Alan

    2015-11-01

    Chest tube malfunction, after the tube thoracostomy, is often the result of an inappropriate chest tube tip position. The aim of this study was to analyse the precision of chest tube placement using the targeted wire guide technique (TWG technique) with curve dilator and to compare it to the classical surgical technique (CS technique). In this clinical study 80 patients with an indication for thoracic drainage, due to pneumothorax or pleural effusion were included. Experimental group contained 39 patients whose chest tube was placed using the TWG technique. The control group contained 41 patients whose chest tube was placed using the CS technique. The comparison of the outcomes of the two techniques applied suggests that the TWG technique was significantly more successful in achieving adequate (precise) chest tube placement, irrespective of patient diagnosis (TWG vs. CS in all patients, 78.4% vs. 36.6%, ppleural effusion group, TWG and CS had success rates of 78.2% and 37.5% (p=0.005), respectively, while in pneumothorax group, TWG and CS had success rates of 78.6% and 35.3% (p=0.029), respectively. Using a curved dilator and the TWG technique for the thoracic drainage procedure we found statistically significant advantage to the TWG technique in comparison to the CS technique (78% vs. 37%) regarding precise chest tube placement within the pleural cavity. Introducing the materials and technique used in this clinical trial into clinical practice may improve the quality of thoracic drainage, including residual volume of air and/or fluid, poor functioning of the chest tube, and, as a consequence of both, prolonged hospitalisation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A step-by-step oncoplastic breast conservation surgical atlas of reproducible dissection techniques and anatomically ideal incision placement.

    Science.gov (United States)

    Mitchell, Sunny D

    2017-10-01

    To develop an atlas for oncoplastic surgery (OPS) with template dissection techniques via anatomically ideal incisions for breast conservation surgery. The evolution of breast conservation techniques has evolved from placing an incision directly over the lesion to the incorporation of a thoughtful decision making process utilizing oncoplastic surgical (OPS) techniques to combining OPS with incision placement in anatomically advantageous sites. The high survival rates of breast cancer and effect of breast surgery on quality of life reinforce emphasis of optimal oncologic as well as aesthetic outcome. OPS results in greater patient satisfaction, fewer surgeries, and is oncologically safe. Today's breast surgeon is tasked with optimizing both oncologic and aesthetic outcomes. Presentation of reproducible dissection techniques and incision placement strategies to afford surgeons a step-by-step approach of OPS via anatomically ideal incisions in breast conservation surgery. Demonstration of reproducible techniques to facilitate the decision making process of optimal breast conservation surgery, eliminate knowledge gaps for surgeons, optimize outcome for individuals undergoing breast conservation surgery, and decrease disparity of care. Adoption of OPS techniques utilizing an anatomically ideal incision in breast conservation surgery is a feasible and reproducible practice for breast surgeons. Application of these techniques results in maintained optimal shape, size, and contour without the typical overlying skin envelope scars. OPS techniques performed under the skin envelope result in expected OPS oncologic and aesthetic outcomes with the addition of the resulting scar(s) in anatomically discrete position(s).

  7. Restoration of immediately placed implants in 3 appointments: from surgical placement to definitive prostheses.

    Science.gov (United States)

    Ercoli, Carlo; Romano, Paul R; Al Mardini, Majd; Cordaro, Luca

    2006-09-01

    This article describes a comprehensive approach that enables the clinician to place dental implants, and fabricate a provisional prosthesis and a definitive metal-acrylic resin or metal-ceramic fixed complete denture in 3 appointments. This technique allows the practitioner to immediately load the implants with a provisional fixed complete denture at the time of implant placement, to record the relative positions of the implants and soft tissues, the occlusal vertical dimension, maxillomandibular relationship, and tooth position at the second appointment by using the information provided by the provisional fixed denture, and to insert the definitive prosthesis at the third appointment. This technique reduces chair time for both the patient and the clinician, and could ultimately reduce the cost of implant treatment and potentially increase treatment acceptance.

  8. Assessment of pain and anxiety following surgical placement of dental implants.

    Science.gov (United States)

    Kim, Sungtae; Lee, Yoon-Jin; Lee, Sojin; Moon, Hong-Seok; Chung, Moon-Kyu

    2013-01-01

    To investigate the change in 89 patients' pain and anxiety following implant surgery and to evaluate the correlation among anxiety, pain, and influencing factors. Eighty-nine patients were included in this study. Subjective factors influencing pain perception included anxiety from the overall dental treatment (scored on the Dental Anxiety Scale [DAS]) and anxiety relative to the time from implant surgery. Objective factors were sex, age, and implant location and number. Patients completed questionnaires just before surgery (T0), immediately after surgery (T1), 1 day after surgery (T2), and 1 week after surgery (T3). The average pain perception was highest at T2, followed by T1 and T3. Pain perception at T1 was significantly higher in women and for a larger number of implant placements. Pain perception at T2 was significantly higher in women and when DAS and anxiety scores were high. The pain score at T3 was significantly higher in women and when anxiety scores were high. The results from multiple linear regression analysis showed that pain perception was significantly higher at T1 in women and for a larger number of implant placements, and at T3 when the dental anxiety score was high. Within the limitations of this study, a patient's anxiety represented by dental anxiety score and state of anxiety scores affected pain intensity 1 day after implant surgery. Sex and the number of implants affected pain intensity immediately after implant surgery. Patients who have high pain intensity 1 week after implant surgery showed high pain intensity at each time point.

  9. Digital design of a surgical guide for placement of definitive implants before orthodontic treatment.

    Science.gov (United States)

    Bayraktaroglu, Hanife Canan; Kim, Jae Seon; Londono, Jimmy; Baker, Philip S

    2015-08-01

    Interdisciplinary treatment planning is an essential part of orthodontic therapy for patients with partial edentulism, especially when dental implants are to serve initially as anchorage and ultimately as prosthetic abutments for the definitive fixed restoration. A technique is presented for designing and fabricating a computed tomography-based surgical guide to place definitive implants before orthodontic therapy. First, the diagnostic cast and the orthodontic tooth arrangement and diagnostic waxing cast are scanned with a 3-dimensional optical scanner. Three-dimensional renderings of these scans are then merged and superimposed onto the cone beam computed tomography (CBCT) image with implant planning software to develop definitive implant positions. A custom surgical guide is fabricated from these data. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  10. A clinically relevant accuracy study of computer-planned implant placement in the edentulous maxilla using mucosa-supported surgical templates.

    NARCIS (Netherlands)

    Verhamme, L.M.; Meijer, G.J.; Boumans, T.; Haan, A.F.J. de; Berge, S.J.; Maal, T.J.J.

    2015-01-01

    PURPOSE: The purpose of the study is to determine the clinically relevant accuracy of implant placement in the edentulous maxilla using computer planning and a mucosa-supported surgical template. MATERIALS AND METHODS: In each of in total 30 consecutive edentulous patients suffering from retention

  11. Deep Circumflex Iliac Artery-Related Hemoperitoneum Formation After Surgical Drain Placement: Successful Transcatheter Embolization

    International Nuclear Information System (INIS)

    Park, Sang Woo; Chang, Seong-Hwan; Yun, Ik Jin; Lee, Hae Won

    2010-01-01

    A 53-year-old woman with liver cirrhosis and hepatocellular carcinoma underwent living donor liver transplantation. After transplantation, her hemoglobin and hematocrit levels decreased to 6.3 g/dl and 18.5%, respectively, during the course of 3 days. A contrast-enhanced abdominal computed axial tomography (CAT) scan showed a hemoperitoneum in the right perihepatic space with no evidence of abdominal wall hematoma or pseudoaneurysm formation. An angiogram of the deep circumflex iliac artery (DCIA) showed extravasation of contrast media along the surgical drain, which had been inserted during the transplantation procedure. Transcatheter embolization of the branches of the DCIA was successfully performed using N-butyl cyanoacrylate.

  12. Predicting erectile dysfunction following surgical correction of Peyronie's disease without inflatable penile prosthesis placement: vascular assessment and preoperative risk factors.

    Science.gov (United States)

    Taylor, Frederick L; Abern, Michael R; Levine, Laurence A

    2012-01-01

    Surgical therapy remains the gold standard treatment for Peyronie's Disease (PD). Surgical options include plication, grafting, and placement of inflatable penile prosthesis (IPP). Postoperative erectile dysfunction (ED) is a potential complication for PD surgery without IPP. We present our large series follow-up to evaluate preoperative risk factors for postoperative ED. The aim of this study is to evaluate preoperative risk factors for the development of ED following surgical correction of PD taking into account the degree of curvature, graft size, surgical approach, hypertension, hyperlipidemia, diabetes, smoking history, preoperative use of phosphodiesterase 5 inhibitors (PDE5), and preoperative duplex ultrasound findings including peak systolic and end diastolic velocities and resistive index. We identified 218 men undergoing either tunica albuginea plication (TAP) or partial plaque excision with pericardial grafting for PD following a previously published algorithm between November 1992 and April 2007. Preoperative and postoperative erectile function, curvature characteristics, presence of vascular risk factors, and duplex ultrasound findings were available on 109 patients. Our primary outcome measure is the development of ED after surgery for PD. Ten percent of TAP and 21% of plaque excision with grafting patients developed postoperative ED. Neither curve direction (P = 0.76), graft area (P = 0.78), surgical approach (P = 0.12), chronic hypertension (P = 0.51), hyperlipidemia (P = 0.87), diabetes (P = 0.69), nor smoking history (P = 0.99) were significant predictors of postoperative ED. No combination of risk factors was found to be predictive of postoperative ED. Preoperative use of PDE5 was not a significant predictor of postoperative ED (P = 0.33). Neither peak systolic, end diastolic, nor resistive index were significant predictors of ED (P = 0.28, 0.28, and 0.25, respectively). This long-term follow-up of a large published series suggests that neither

  13. Surgical gastrojejunostomy or endoscopic stent placement for the palliation of malignant gastric outlet obstruction (SUSTENT study): a multicenter randomized trial

    NARCIS (Netherlands)

    Jeurnink, Suzanne M.; Steyerberg, Ewout W.; van Hooft, Jeanin E.; van Eijck, Casper H. J.; Schwartz, Matthijs P.; Vleggaar, Frank P.; Kuipers, Ernst J.; Siersema, Peter D.; Jeurnink, S. M.; Kuipers, E. J.; Siersema, P. D.; Steyerberg, E. W.; Polinder, S.; Borsboom, G.; van Eijck, C. H. J.; Fockens, P.; Gouma, D. J.; Schwartz, M. P.; Vermeijden, J. R.; van Ooijen, B.; Vleggaar, F. P.; Borel Rinkes, I. H. M.; Grubben, M.; van Laarhoven, C. H. J. M.; Peters, F. T. M.; Porte, R. J.; Plukker, J. Th M.; van Spreeuwel, J. P.; Jakimowicz, J. J.; Boot, H.; Cats, A.; van Coevorden, F. V.; Klaase, J. M.; van der Waaij, L. A.; Baas, P.; van der Schaar, P.; Sosef, M. N.; Timmer, R.; van Ramshorts, B.; Nicolai, J. J.; Houben, M. H. M. G.; Steup, W. H.; Pahlplatz, P. V. M.; Brouwers, M. A. M.; Meijssen, M. A. C.; Marinelli, A.; van der Linde, K.; Manusama, E.; ter Borg, F.; Eeftinck Schattenkerk, M.; Witteman, B.; Kruyt, F.; ten Hove, R.; Schmitz, R. F.; Lesterhuis, W.; Oostenbroek, R.; Veenendaal, R.; Hartgrink, H. H.; Tollenaar, R. A. E. M.; Wahab, P.; Spillenaar Bilgen, E. J.

    2010-01-01

    BACKGROUND: Both gastrojejunostomy (GJJ) and stent placement are commonly used palliative treatments of obstructive symptoms caused by malignant gastric outlet obstruction (GOO). OBJECTIVE: Compare GJJ and stent placement. DESIGN: Multicenter, randomized trial. SETTING: Twenty-one centers in The

  14. Accuracy of a real-time surgical navigation system for the placement of quad zygomatic implants in the severe atrophic maxilla: A pilot clinical study.

    Science.gov (United States)

    Hung, Kuo-Feng; Wang, Feng; Wang, Hao-Wei; Zhou, Wen-Jie; Huang, Wei; Wu, Yi-Qun

    2017-06-01

    A real-time surgical navigation system potentially increases the accuracy when used for quad-zygomatic implant placement. To evaluate the accuracy of a real-time surgical navigation system when used for quad zygomatic implant placement. Patients with severely atrophic maxillae were prospectively recruited. Four trajectories for implants were planned, and zygomatic implants were placed using a real-time surgical navigation system. The planned-placed distance deviations at entry (entry deviation)points, exit (exit deviation) points, and angle deviation of axes (angle deviation) were measured on fused operation images. The differences of all the deviations between different groups, classified based on the lengths and locations of implants, were analysed. A P value of implants were placed as planned in 10 patients. The entry deviation, exit deviation and angle deviation were 1.35 ± 0.75 mm, 2.15 mm ± 0.95 mm, and 2.05 ± 1.02 degrees, respectively. The differences of all deviations were not significant, irrespective of the lengths (P = .259, .158, and .914, respectively) or locations of the placed implants (P = .698, .072, and .602, respectively). A real-time surgical navigation system used for the placement of quad zygomatic implants demonstrated a high level of accuracy with only minimal planned-placed deviations, irrespective of the lengths or locations of the implants. © 2017 Wiley Periodicals, Inc.

  15. Spacer st4ructure

    International Nuclear Information System (INIS)

    Masetti, W.R.

    1978-01-01

    A spacer structure is described for maintaining a spaced relation between a plurality of generally parallel fuel rods within a housing in a nuclear reactor. The spacer structure is comprised of a grid pattern of ribs slotted to interlock with each other. The slots are arranged in such a way that when the ribs are welded to each other, the weld shrinkage is distributed uniformly in all directions to reduce or eliminate the amount of rework necessary in manufacturing the spacer structure

  16. Mixing vane grid spacer

    International Nuclear Information System (INIS)

    Patterson, J.F.; Galbraith, K.P.

    1978-01-01

    An improved mixing vane grid spacer having enhanced flow mixing capability by virtue of mixing vanes being positioned at welded intersecting joints of the spacer wherein each mixing vane has an opening or window formed therein substantially directly over the welded joint to provide improved flow mixing capability is described. Some of the vanes are slotted, depending on their particular location in the spacers. The intersecting joints are welded by initially providing consumable tabs at and within each window, which are consumed during the welding of the spacer joints

  17. Fouling resistant membrane spacers

    KAUST Repository

    Ghaffour, Noreddine

    2017-10-12

    Disclosed herein are spacers having baffle designs and perforations for efficiently and effectively separating one or more membrane layers a membrane filtration system. The spacer (504) includes a body (524) formed at least in part by baffles (520) that are interconnected, and the baffles define boundaries of openings or apertures (525) through a thickness direction of the body of the spacer. Alternatively or additionally, passages or perforations (526A, 526B) may be present in the spacer layer or baffles for fluid flow there through, with the passages and baffles having a numerous different shapes and sizes.

  18. Surgical Protocol and Short-Term Clinical Outcome of Immediate Placement in Molar Extraction Sockets Using a Wide Body Implant

    Science.gov (United States)

    Vandeweghe, Stefan; Hattingh, André; Wennerberg, Ann

    2011-01-01

    ABSTRACT Objectives Implant placement in molar extraction sockets can be difficult due to complex multi-root anatomy and the lack of predictable primary stability. The aim of this study was to evaluate the outcome of an 8 - 9 mm diameter tapered implant, designed to be placed in molar extraction sockets. Material and methods Patients treated at least 1 year before with a Max® implant (Southern Implants, Irene, South Africa) were invited for a clinical examination. Variables collected were surgical and prosthetic protocol, implant dimension and smoking habits. Peri-implant bone level was determined on peri-apical radiographs and compared to baseline, being implant insertion. Results 98 implants had been placed in 89 patients. One implant had failed. Thirty eight patients representing 47 implants (maxilla 26, mandible 21) were available for clinical examination. Mean bone loss was 0.38 mm (SD 0.48; range - 0.50 – 1.95) after a mean follow-up of 20 months (range 12 - 35). Implant success was 97.9%. Around 30 implants, a bone substitute was used to fill the residual space, but this did not affect the bone loss outcome. Bone loss was only significantly different between maxilla and mandible (0.48 mm vs. 0.27 mm) and between the 8 and 9 mm diameter implants (0.23 mm vs. 0.55 mm). A full papilla was present at 71% of the interproximal sites and irrespective of bone loss. Conclusions The Max® implant demonstrated good primary stability, when placed in molar extraction sockets, with limited bone loss over time. PMID:24421993

  19. Surgical Protocol and Short-Term Clinical Outcome of Immediate Placement in Molar Extraction Sockets Using a Wide Body Implant

    Directory of Open Access Journals (Sweden)

    Stefan Vandeweghe

    2011-08-01

    Full Text Available Objectives: Implant placement in molar extraction sockets can be difficult due to complex multi-root anatomy and the lack of predictable primary stability. The aim of this study was to evaluate the outcome of an 8 - 9 mm diameter tapered implant, designed to be placed in molar extraction sockets.Material and methods: Patients treated at least 1 year before with a Max® implant (Southern Implants, Irene, South Africa were invited for a clinical examination. Variables collected were surgical and prosthetic protocol, implant dimension and smoking habits. Peri-implant bone level was determined on peri-apical radiographs and compared to baseline, being implant insertion.Results: 98 implants had been placed in 89 patients. One implant had failed. Thirty eight patients representing 47 implants (maxilla 26, mandible 21 were available for clinical examination. Mean bone loss was 0.38 mm (SD 0.48; range - 0.50 – 1.95 after a mean follow-up of 20 months (range 12 - 35. Implant success was 97.9%. Around 30 implants, a bone substitute was used to fill the residual space, but this did not affect the bone loss outcome. Bone loss was only significantly different between maxilla and mandible (0.48 mm vs. 0.27 mm and between the 8 and 9 mm diameter implants (0.23 mm vs. 0.55 mm. A full papilla was present at 71% of the interproximal sites and irrespective of bone loss.Conclusions: The Max® implant demonstrated good primary stability, when placed in molar extraction sockets, with limited bone loss over time.

  20. Ultrasound-guided supra-acetabular pin placement in pelvic external fixation: description of a surgical technique and results.

    Science.gov (United States)

    Chana-Rodríguez, Francisco; Cuervas-Mons, Manuel; Rojo-Manaute, José; Mora, Félix; Arnal, Juan; Vaquero-Martín, Javier

    2017-11-01

    Pelvic fracture in trauma patients can lead to hemodynamic instability. External fixation is a treatment capable of stabilizing these injuries in the context of damage control surgery. Supra-acetabular pin offers the greater biomechanical stability but requires the use of intraoperative fluoroscopy. The aim of this study was to analyze our results for an ultrasound-guided supra-acetabular pinning. Cross-sectional study with cadaveric specimens. Ultrasound-guided pin placement assessed by fluoroscopy and dissection. Fourteen ultrasound-guided supra-acetabular pins were placed in seven cadaveric specimens. Excellent placement in all cases, evaluated with radiological control. Good qualitative bone fixation after dissection. One femoral cutaneous nerve was not found during anatomic dissection and was assumed injured. Ultrasound-guided supra-acetabular pin placement is a feasible and effective technique. Our study indicates that pin placement without intraoperative fluoroscopy is feasible without compromising the reliability of its placement. © 2017 Elsevier Ltd. All rights reserved.

  1. Structural Stator Spacers

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andreasen, Jens H.; Pijanowski, J. M.

    2001-01-01

    This paper presents a powerful new design aspect to reduce acoustic noise and vibration of electro-magnetic origin for electrical machines, by introducing improved slot wedges referred to as "Structural Stator Spacers". These spacers, by using a very stiff dielectric and non magnetic material, a ...

  2. Real-time thermographic analysis of low-density bone during implant placement: a randomized parallel-group clinical study comparing lateral condensation with bone drilling surgical technique.

    Science.gov (United States)

    Marković, Aleksa; Mišić, Tijana; Mančić, Dragan; Jovanović, Igor; Šćepanović, Miodrag; Jezdić, Zoran

    2014-08-01

    To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites. Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing. A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P ≤ 0.0005), it was significantly higher for bone condensing compared with drilling (P ≤ 0.0005; 3.79 ± 1.54°C; 1.91 ± 0.70°C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%. Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly. © 2013 John Wiley & Sons A/S. Published by John Wiley

  3. Gastroduodenal stent placement versus surgical gastrojejunostomy for the palliation of gastric outlet obstructions in patients with unresectable gastric cancer: a propensity score-matched analysis.

    Science.gov (United States)

    Park, Jung-Hoon; Song, Ho-Young; Yun, Sung-Cheol; Yoo, Moon-Won; Ryu, Min-Hee; Kim, Jin Hyoung; Kim, Do Hoon; Lee, Jeong Hoon; Zhou, Wei-Zhong; Yook, Jeong Hwan; Jung, Hwoon-Yong

    2016-08-01

    To compare the outcomes between stent placement and surgical gastrojejunostomy (GJ) for the palliation of gastric outlet obstruction (GOO) in patients with unresectable gastric cancer. A retrospective study was performed in a single university hospital in 224 patients with GOO, and who were treated either by stent placement (n = 124) or surgical GJ (n = 100). The outcomes were assessed with reference to the following variables with the use of propensity-score matching: success rates; complications; dysphagia scores, albumin, and body mass index; survival; symptom-free duration; and hospitalization. We identified a well-balanced cohort of 74 pairs of patients, matched on the basis of propensity score. The dysphagia score 7 days after treatment was significantly better in the stent group (P obstruction symptoms and better nutritional status. • The two methods are equally effective in palliating gastric outlet obstruction symptoms • The stent group showed rapid and efficient palliation of symptoms • Recurrent symptoms were more frequent in the stent group • Surgical gastrojejunostomy provides a longer symptom-free duration and better nutritional status.

  4. Accuracy and complications of computer-designed selective laser sintering surgical guides for flapless dental implant placement and immediate definitive prosthesis installation.

    Science.gov (United States)

    Di Giacomo, Giovanni A; da Silva, Jorge V; da Silva, Airton M; Paschoal, Gustavo H; Cury, Patricia R; Szarf, Gilberto

    2012-04-01

    Computer-aided dental implant placement seems to be useful for placing implants by using a flapless approach. However, evidence supporting such applications is scarce. The aim of this study is to evaluate the accuracy of and complications that arise from the use of selective laser sintering surgical guides for flapless dental implant placement and immediate definitive prosthesis installation. Sixty implants and 12 prostheses were installed in 12 patients (four males and eight females; age range: 41 to 71 years). Lateral (coronal and apical) and angular deviations between virtually planned and placed implants were measured. The patients were followed up for 30 months, and surgical and prosthetic complications were documented. The mean ± SD angular, coronal, and apical deviations were 6.53° ± 4.31°, 1.35 ± 0.65 mm, and 1.79 ± 1.01 mm, respectively. Coronal and apical deviations of prosthesis, and prosthesis fracture. The cumulative survival rates for implants and prostheses were 98.33% and 91.66%, respectively. The mean lateral deviation was 2 mm. The complication rate was 34.4%. Hence, computer-aided dental implant surgery still requires improvement and should be considered as in the developmental stage.

  5. INTERSPINOUS SPACER IN PERSISTENT DISCOGENIC PAIN: PERCUTANEOUS APPROACH OR OPEN TECHNIQUE

    Directory of Open Access Journals (Sweden)

    José Antonio Cruz Ricardez

    Full Text Available ABSTRACT Objective: To compare the postoperative clinical course of placement of interspinous spacer with open technique (ISO with percutaneous interspinous spacer (PIS. Methods: Quasi-experimental, longitudinal study of 42 patients with discogenic pain uncontrolled with analgesics, aged 35-55 years old, 21 women, and 21 men. Clinical history, location of pain, VAS scale before and after surgery, Oswestry Disability Index and Macnab modified scale at 6 months were used. Results: When performing quantitative analysis statistical significance (p = 0.0478, 0.0466, 0.0399 was demonstrated with Student's t test between the results according to VAS scale; in the qualitative analysis with the Oswestry index and Macnab modified scale it was demonstrated the hypothesis that the results is dependent of the surgical technique. Conclusions: According to the results, we can conclude that there is a statistically significant difference depending on the surgical technique used with respect to the rate of disability and functionality in daily life as well as in the improvement of pain symptoms.

  6. Familial placement of Wightia (Lamiales)

    DEFF Research Database (Denmark)

    Zhou, Qing-Mei; Jensen, Søren Rosendal; Liu, Guo-Li

    2014-01-01

    The familial placement of Wightia has long been a problem. Here, we present a comprehensive phylogenetic inspection of Wightia based on noncoding chloroplast loci (the rps16 intron and the trnL–F region) and nuclear ribosomal internal transcribed spacer, and on chemical analysis. A total of 70 sa...

  7. Perioperative management of gastrostomy tube placement in Duchenne muscular dystrophy adolescent and young adult patients: A role for a perioperative surgical home.

    Science.gov (United States)

    Boivin, Ariane; Antonelli, Richard; Sethna, Navil F

    2018-02-01

    In past decades, Duchenne muscular dystrophy patients have been living longer and as the disease advances, patients experience multisystemic deterioration. Older patients often require gastrostomy tube placement for nutritional support. For optimizing the perioperative care, a practice of multidisciplinary team can better anticipate, prevent, and manage possible complications and reduce the overall perioperative morbidity and mortality. The aim of this study was to review our experience with perioperative care of adolescent and young adults with Duchenne muscular dystrophy undergoing gastrostomy by various surgical approaches in order to identify challenges and improve future perioperative care coordination to reduce morbidity. We retrospectively examined cases of gastrostomy tube placement in patients of ages 15 years and older between 2005 and 2016. We reviewed preoperative evaluation, anesthetic and surgical management, and postoperative complications. Twelve patients were identified; 1 had open gastrostomy, 3 laparoscopic gastrostomies, 5 percutaneous endoscopic guided, and 3 radiologically inserted gastrostomy tubes. All patients had preoperative cardiac evaluation with 6 patients demonstrating cardiomyopathy. Nine patients had preoperative pulmonary consultations and the pulmonary function tests reported forced vital capacity of ≤36% of predicted. Eight patients were noninvasive positive pressure ventilation dependent. General anesthesia with tracheal intubation was administered in 8 patients, and intravenous sedation in 4 patients; 1 received sedation supplemented with regional anesthesia and 3 received deep sedation. One patient had a difficult intubation that resulted in trauma and prolonged tracheal intubation. Three patients developed postoperative respiratory complications. Two patients' procedures were postponed due to inadequate preoperative evaluation and 1 because of disagreement between anesthesia and procedural services as to the optimal

  8. Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement

    Science.gov (United States)

    2011-01-01

    Background Percutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Methods Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Results Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P corridor of choice in patients with sacral dysmorphia. Conclusions These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable

  9. Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement

    Directory of Open Access Journals (Sweden)

    Newman Justin T

    2011-05-01

    Full Text Available Abstract Background Percutaneous sacro-iliac (SI screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Methods Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Results Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%. The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069. In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99 having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal, compared to male counterparts (n = 245; P P = 0.06, implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia. Conclusions These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients

  10. Nasogastric tube placement into the hepaticojejunostomy anastomosis in pancreaticoduodenectomy: a simple surgical technique for prevention of bile leak.

    Science.gov (United States)

    Kaya, Bulent; Ozcabi, Yetkin; Tasdelen, Iksan; Onur, Ender; Memisoglu, Kemal

    2016-05-01

    Hepaticojejunostomy is an important part of many surgical procedures including pancreaticoduodenectomy. Biliary leakage from hepaticojejunostomy may be associated with intraabdominal abscess formation, biliary peritonitis, and even mortality. A 72-year-old female patient was admitted to our hospital with obstructive jaundice. After initial evaluation, she was diagnosed with distal common bile duct obstruction without accurate diagnosis. Before planned pancreaticoduodenectomy, biliary drainage with a T-tube was performed due to the presence of cholangitis. After the first operation, pancreaticoduodenectomy was performed. Postinflammatory changes around the hilar region made the hepaticojejunostomy risky. A bilio-digestive anastomosis was performed using a new technique. A nasogastric tube was placed into the common bile duct proximal to the anastomosis. The postoperative course of the patient was uneventful. The use of a nasogastric tube as a stent in risky hepaticojejunostomies is a simple technique that can be beneficial.

  11. Single Sitting Surgical Treatment of Generalized Aggressive Periodontitis Using GTR Technique and Immediate Implant Placement with 10-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Fatme Mouchref Hamasni

    2018-01-01

    Full Text Available This case report exhibits a patient with generalized aggressive periodontitis who has been under maintenance for the past 12 years after being surgically treated in a single sitting and restored with dental implants. A 41-year-old systemically healthy male patient presented complaining of lower anterior teeth mobility and pain in the upper right quadrant. After clinical and radiographic examination, the upper right molars and lower anterior incisors were deemed unrestorable. Covered by doxycycline, the patient received a nonsurgical periodontal treatment. Three weeks later, teeth extraction, immediate implant placement, immediate nonloading provisional prosthesis, and a guided tissue regeneration were performed at indicated areas in a single sitting. The clinical decisions were based on patient compliance, the status of the existing periodontal tissues, and the prognosis of the remaining teeth. During the 12-year follow-up period, no residual pockets were observed and there was no exacerbation of the inflammatory condition. Marginal bone stability is present on all implants. For aggressive periodontal disease, a high risk of relapse as well as limited success and survival of dental implants should be considered. This case shows proper containment of the disease based on appropriate treatment planning and a strict maintenance program.

  12. Histopathological comparative analysis of peri-implant soft tissue response after dental implant placement with flap and flapless surgical technique. Experimental study in pigs.

    Science.gov (United States)

    Vlahovic, Zoran; Markovic, Aleksa; Golubovic, Mileta; Scepanovic, Miodrag; Kalanovic, Milena; Djinic, Ana

    2015-11-01

    The aim of this study was comparing the effect of flapless vs. flap technique of implant placement on inflammation degree of peri-implant soft tissue, through histopathological analysis. The experiment was conducted on five domestic pigs. Nine weeks after tooth extraction, implants were installed. Each animal received six implants in mandible. According to split-mouth design, randomly one side was used for flapless technique using mini-incision, while on the other side, flap was raised. After 7, 14, 21, 28, and 90 days, the experimental animals were sacrificed. Samples for histopathological analyzes were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The degree of inflammatory response in the peri-implant soft tissue was estimated through ordinal scores from 0 to 3. In the flap group Score 3 indicating high degree of inflammation was present from day 7 to day 21, in contrast to flapless group where Score 3 was not recorded during the entire follow-up. Three months after implantation, there were no signs of inflammation neither around flap nor around flapless implants. Flapless surgical implantation technique using mini-incision decreases peri-implant soft tissue inflammatory reaction compared with flap surgery. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Spacer grid corner gusset

    International Nuclear Information System (INIS)

    Larson, J.G.

    1984-01-01

    There is provided a spacer grid for a bundle of longitudinally extending rods in spaced generally parallel relationship comprising spacing means for holding the rods in spaced generally parallel relationship; the spacing means includes at least one exterior grid strip circumscribing the bundle of rods along the periphery thereof; with at least one exterior grid strip having a first edge defining the boundary of the strip in one longitudinal direction and a second edge defining the boundary of the strip in the other longitudinal direction; with at least one exterior grid strip having at least one band formed therein parallel to the longitudinal direction; a plurality of corner gussets truncating each of a plurality of corners formed by at least one band and the first edge and the second edge

  14. Long-Term Outcomes of Permanent Cement Spacers in the Infected Foot.

    Science.gov (United States)

    Elmarsafi, Tammer; Oliver, Noah G; Steinberg, John S; Evans, Karen K; Attinger, Christopher E; Kim, Paul J

    When osteomyelitis occurs in the infected foot, cement spacers have been used as a limb salvage tool. The aim of the present study was to assess the longevity and outcomes in high-risk, low-demand patients who have undergone resection of bone and subsequent placement of permanent antibiotic-eluting cement spacers in the foot. A retrospective review case series of 30 patients who had undergone placement of a permanent antibiotic-eluting cement spacer in the foot were evaluated for retention, spacer exchange, removal, amputation, and functional status. The minimum follow-up time for inclusion was 12 months. Two thirds of all patients had successful spacers (n = 20) that were either retained (n = 14) or successfully exchanged (n = 6). One third of all patients experienced spacer failure (n = 10) and required removal. Of the 10 patients requiring spacer removal, 4 underwent removal with subsequent arthrodesis and 6 underwent removal with subsequent pseudoarthrosis. Also, 8 of these patients (26.7%) required partial foot amputation of the ipsilateral foot. These amputations were not directly related to the use or removal of the spacer. The average time to spacer removal or partial amputation was 20.9 (range 0.2 to 60.9) months. The longest retained spacer in the foot was 76 months at the last follow-up visit. The longest exchanged spacer at the last follow-up visit was 111 months. All surviving patients were ambulatory at the last follow-up visit. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sunil Munakomi

    2016-11-01

    Full Text Available Objective: Anterior odontoid screw fixation for type II odontoid fracture is the ideal management option. However in the context of unavailability of an O-arm or neuro-navigation and poor images from the available C-arm may be an obstacle to ideal trajectory and placement of the odontoid screw. We herein detail  our surgical technique so as to ensure a correct trajectory and subsequent good fusion in Type II odontoid fractures. This may be advantageous  in clinical set ups lacking state of the art facilities.  Methods and Results: In this cohort study we included 15 consecutive patients who underwent anterior odontoid screw placement. We routinely dissect the longus colli to completely visualize the entire width of C3 body. We then perform a median C2-C3 disectomy followed by creating a gutter in the superior end of C3 body. We then guide the Kirchsner (K wire purchasing adequate anterior cortex of C2. Rest of the procedure follows the similar steps as described for odontoid screw placement. We achieved 100% correct trajectory and screw placement in our study. There were no instances of screw break out, pull out or nonunion. There was one patient mortality following myocardial infarction in our study. Conclusion: Preoperative imaging details, proper patient positioning, meticulous dissection, thorough anatomical knowledge and few added surgical nuances are the cornerstones in ideal odontoid screw placement. This may be pivotal in managing  patients in developing nations having rudimentary neurosurgical set up.

  16. Spacer grid for fuel elements

    International Nuclear Information System (INIS)

    Hensolt, T.; Huenner, M.; Rau, P.; Veca, A.

    1978-01-01

    The spacer grid for fuel elements of a gas-cooled fast breeder reactor (but also for PWRs and BWRs) consists of a lattice field with dodecagonal meshes. These meshes are formed by three each adjacent hexagons grouped arround a central axis. The pairs of legs extending into the dodecagon and being staggered by 120 0 are designed as knubs with inclined abutting surfaces for the fuel rods. By this means there is formed a three-point bearing for centering the fuel rods. The spacer grid mentioned above is rough-worked from a single disc- resp. plate-shaped body (unfinished piece). (DG) [de

  17. Spacer grid for fuel elements

    International Nuclear Information System (INIS)

    Hensolt, T.; Huenner, M.; Rau, P.; Veca, A.

    1980-01-01

    The spacer grid for fuel elements of a gas-cooled fast breeder reactor (but also for PWRs and BWRs) consists of a lattice field with dodecagonal meshes. These meshes are formed by three each adjacent hexagons grouped arround a central axis. The pairs of legs extending into the dodecagon and being staggered by 120 are designed as knubs with inclined abutting surfaces for the fuel rods. By this means there is formed a three-point bearing for centering the fuel rods. The spacer grid mentioned above is rough-worked from a single disc- resp. plate-shaped body (unfinished piece). (orig.)

  18. Analyzing block placement errors in SADP patterning

    Science.gov (United States)

    Kobayashi, Shinji; Okada, Soichiro; Shimura, Satoru; Nafus, Kathleen; Fonseca, Carlos; Demand, Marc; Biesemans, Serge; Versluijs, Janko; Ercken, Monique; Foubert, Philippe; Miyazaki, Shinobu

    2016-03-01

    We discuss edge placement errors (EPE) for multi-patterning of Mx critical layers using ArF lithography. Specific focus is placed on the block formation part of the process. While plenty of literature characterization data exist on spacer formation, only limited published data is available on block processes. We analyze the accuracy of placing blocks relative to narrow spacers. Many publications calculate EPE assuming Gaussian distributions for key process variations contributing to EPE. For practical reasons, each contributor is measured on dedicated test structures. In this work, we complement such analysis and directly measure the EPE in product. We perform high density sampling of blocks using CDSEM images and analyze all feature edges of interest. We find that block placement errors can be very different depending on their local design context. Specifically we report on 2 block populations (further called block A and B) which have a 4x different standard deviation. We attribute this to differences in local topography (spacer shape) and interaction with the plasma-etch process design. Block A (on top of the `core space' S1) has excellent EPE uniformity of ~1 nm while block B (on top of `gap space' S2) has degraded EPE control of ~4 nm. Finally, we suggest that the SOC etch process is at the origin on positioning blocks accurately on slim spacers, helping the manufacturability of spacer-based patterning techniques, and helping its extension toward the 5nm node.

  19. Hydrogel spacer distribution within the perirectal space in patients undergoing radiotherapy for prostate cancer: Impact of spacer symmetry on rectal dose reduction and the clinical consequences of hydrogel infiltration into the rectal wall.

    Science.gov (United States)

    Fischer-Valuck, Benjamin W; Chundury, Anupama; Gay, Hiram; Bosch, Walter; Michalski, Jeff

    Hydrogel prostate-rectum spacers, biomaterials placed between the prostate and rectum, continue to gain interest as a method to reduce or limit rectal dose during dose escalated prostate cancer radiation therapy. Because the spacer is initially injected into the perirectal space as a liquid, the final distribution can vary. The purpose of this study was to evaluate hydrogel spacer (SpaceOAR system) implantation and distribution from a recent prospective randomized control trial and correlate spacer symmetry with rectal dose reduction as well as rectal wall infiltration (RWI) to acute and late toxicity. T2-weighted magnetic resonance imaging sets of 149 patients enrolled in a prospective clinical trial who received transperineal spacer injection were assessed for hydrogel spacer midline symmetry and RWI using a semiqualitative scoring system. Symmetry was then correlated to rectal dose reduction using a Student t test (1-tailed, paired), whereas a Fisher exact test was used to correlate RWI with acute and late rectal toxicity. All patients had control treatment plans created before spacer injection. Hydrogel spacer was symmetrically placed at midline for 71 (47.7%) patients at the prostate midgland as well as 1 cm superior and inferior to midgland. The remaining 78 (50.9%) patients had some level of asymmetry, with only 2 (1.3%) having far lateral distribution (ie, >2 cm) of hydrogel spacer. As the hydrogel spacer became more asymmetric, the level of rectal dose reduction relative to their control plans decreased. However, all but the most asymmetrical 1.3% had significant rectal dose reduction (P < .05). Rectal wall hydrogel spacer infiltration was seen in 9 (6.0%) patients. There was no correlation between RWI and procedure-related adverse events or acute/late rectal toxicity. Significant reduction of rectal dose can still be achieved even in the setting of asymmetric hydrogel spacer placement. RWI does not correlate with patient complications. Copyright © 2016

  20. Paving the Way for Implant Placement for an Auricular Prosthesis

    Directory of Open Access Journals (Sweden)

    Dipti S Shah

    2013-01-01

    Full Text Available Background: Ideal placement of bone integrated implants to retain a prosthesis is critical for a successful final prosthetic restoration. Several sources have described the importance and use of surgical templates for the optimal placement of extraoral implants. The literature is replete with information explaining the use of surgic al templates for intraoral implant placement. Indeed, correct placement of implants facilitates creating a prosthesis that functions well and looks natural. To ensure proper implant placement, considerable effort should go into pre-surgical planning. It is clear that extraoral surgical templates aid in proper implant placement, yet the literature describing fabrication is limited. This article describes different methods for fabrication of surgical template for placement of implants for an auricular prosthesis.

  1. Temporary placement of covered retrievable expandable nitinol stents with barbs in high-risk surgical patients with benign prostatic hyperplasia: work in progress.

    Science.gov (United States)

    Kim, Choung-Soo; Song, Ho-Young; Jeong, In Gab; Yeo, Hyun Jin; Kim, Eun-Young; Park, Jung-Hoon; Yoon, Chang Jin; Paick, Sung Hyun; Park, Sang Woo; Bae, Jae-Ik; Won, Je Hwan

    2011-10-01

    To report the use of a newly constructed, covered, retrievable, expandable nitinol stent with barbs to overcome the problem of stent migration associated with conventional covered prostatic expandable stents and to evaluate prospectively the technical feasibility and clinical effectiveness of the stents in patients with benign prostatic hyperplasia (BPH). A covered retrievable expandable nitinol stent with four barbs was placed with use of an 18-F stent delivery system in seven consecutive patients with symptomatic BPH who had high operative risks. Age range of patients was 62-83 years (mean 74 years). In cases in which the stent migrated, it was replaced with a stent with eight barbs. The stents were routinely removed 4 months after placement using a 21-F stent removal set. Stent placement was technically successful and well tolerated in six of the seven patients. The remaining patient needed a second stent placement after removal of the first stent. The stent with four barbs migrated into the urinary bladder in four patients (57%); three of these patients received a second stent with eight barbs with good results, and the fourth patient did not need further treatment because his symptoms improved. Routine removal of the stent 4 months after placement was performed in three of the seven patients with good results. Retrievable stents with eight barbs seem to overcome the problem of stent migration associated with conventional prostatic expandable stents. Preliminary results suggest that stents with barbs are both feasible and effective in patients with BPH. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  2. A comparison of the accuracy and safety of vertebral body pin placement using a fluoroscopically guided versus an open surgical approach: an in vitro study.

    Science.gov (United States)

    Wheeler, Jason L; Cross, Alan R; Rapoff, Andrew J

    2002-01-01

    To compare the safety and accuracy of Steinmann pin placement in vertebral bodies T10 through L7 using either an open or closed fluoroscopic method. In vitro radiographic and anatomic study. Ten medium-sized canine cadavers. Cadavers were randomly assigned to 2 groups: open and closed. Steinmann pins were placed in vertebral bodies through a standard dorsal incision in the open group and percutaneously with the aid of fluoroscopy in the closed group. Pins were placed bilaterally in vertebral bodies T10 through L7 at approximately 30 degrees from horizontal and driven to a uniform depth. Necropsies were performed to examine potential pulmonary, vascular, or neurological trauma as a result of pin placement. Spines were cross-sectioned through intervertebral disc spaces, and radiographs were performed to evaluate accuracy of pin placement. Descriptive statistics were determined for pin angle, percentage of bone purchase, and penetration length. Means of interest between groups were compared using a Student t test. Complication incidence was compared using Chi;(2) analysis. Significance was P thoracic and lumbar vertebrae and for the closed group in thoracic vertebrae. Mean pin insertion angle for all vertebrae was significantly greater than 30 degrees for the open group. Mean pin penetration distance in each vertebra was significantly different between groups with the closed group having less penetration and lower variance. Both groups were significantly different from the ideal penetration distance. The mean percentage of bone purchase was greater in the closed group for all vertebrae except T10 and T11. The complication incidence was significantly greater in the open group for thoracic vertebrae. The results of this study suggest that a closed technique for placement of Steinmann pins in lumbar vertebrae for use in external skeletal fixation is a reasonable and safer alternative to the traditional open technique. Use of either technique in thoracic vertebrae should

  3. Polyetheretherketone (PEEK) Spacers for Anterior Cervical Fusion: A Retrospective Comparative Effectiveness Clinical Trial.

    Science.gov (United States)

    Lemcke, Johannes; Al-Zain, Ferass; Meier, Ullrich; Suess, Olaf

    2011-01-01

    Anterior cervical decompression and fusion (ACDF) is the standard surgical treatment for radiculopathy and myelopathy. Polyetheretherketone (PEEK) has an elasticity similar to bone and thus appears well suited for use as the implant in ACDF procedures. The aim of this study is to examine the clinical and radiographic outcome of patients treated with standing alone PEEK spacers without bone morphogenic protein (BMP) or plating and to examine the influence of the different design of the two spacers on the rate of subsidence and dislocation. This retrospective comparative study reviewed 335 patients treated by ACDF in a specialized urban hospital for radiculopathy or myelopathy due to degenerative pathologies. The Intromed PEEK spacer was used in 181 patients from 3/2002 to 11/2004, and the AMT SHELL spacer was implanted in 154 patients from 4/2004 to 12/2007. The follow-up rate was 100% at three months post-op and 82.7% (277 patients) at one year. The patients were assessed with the Japanese Orthopedic Association (JOA) questionnaire and radiographically. At the one-year follow-up there were 118/277 patients with an excellent clinical outcome on the JOA, 112/277 with a good outcome, 20/277 with a fair outcome, and 27/277 with a poor outcome. Subsidence was observed in 13.3% of patients with the Intromed spacer vs 8.4% of the patients with the AMT SHELL. Dislocation of the spacer was observed in 10 of the 181 patients with Intromed spacers but in none of the 154 patients with Shell spacers. The study demonstrates that ACDF with standing alone PEEK cages leads to excellent and good clinical outcomes. The differences we observed in the subsidence rate between the two spacers were not significant and cannot be related to a single design feature of the spacers.

  4. Two pion correlation from SPACER

    International Nuclear Information System (INIS)

    Csoergoe, T.; Zimanyi, J.; Pratt, S.

    1989-12-01

    The correlation function for neutral and negative pions produced in ultrarelativistic heavy ion collisions was calculated without free parameters based on a space-time version of the LUND model, called SPACER: Simulation of Phase space distribution of Atomic nuclear Collisions in Energetic Reactions. This method includes the effect of Bose correlations for the emitted pion pair. Effects arising from correlations between space-time and momentum space distributions are investigated. The results are compared to the data of two different experiments. The role and interpretation of the chaocity parameter are discussed. (D.G.) 14 refs.; 4 figs

  5. Spacers for fuel rod clusters

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1978-01-01

    The proposition deals with the fixing of nuclear fuel element rods in a grid which consists of a number of crossed Zy-plates which form cells. The rectangular cells have projections which serve as spacers for the fuel rods. According to the invention there are additional butt straps which can be moved in such a way that insertion and extraction of the fuel rods can be done without obstruction and they can be spring-loaded hold in their final position. (UWI) [de

  6. STUDENT PLACEMENT

    African Journals Online (AJOL)

    User

    students express lack of interest in the field they are placed, it ... be highly motivated to learn than students placed in a department ... the following research questions. Research Questions. •. Did the criteria used by Mekelle. University for placement of students into different departments affect the academic performance of ...

  7. Percutaneous Placement of Peritoneal Dialysis Catheters in ...

    African Journals Online (AJOL)

    Background: The percutaneous placement of peritoneal dialysis (PD) catheters using conscious sedation with ultrasound and fluoroscopic guidance is underutilised and hasseveral advantages over the open surgical and laparoscopic placement methods, especially in the resource-limited developing world. Objectives: To ...

  8. Electromagnetic guided bedside or endoscopic placement of nasoenteral feeding tubes in surgical patients (CORE trial) : Study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Gerritsen, Arja; de Rooij, Thijs; Dijkgraaf, Marcel G.; Busch, Olivier R.; Bergman, Jacques J.; Ubbink, Dirk T.; van Duijvendijk, Peter; Erkelens, G. Willemien; Molenaar, IQ; Monkelbaan, JF; Rosman, Camiel; Tan, Adriaan C.; Kruyt, Philip M.; Bac, Dirk Jan; Mathus-Vliegen, Elisabeth M.; Besselink, Marc G.

    2015-01-01

    Background: Gastroparesis is common in surgical patients and frequently leads to the need for enteral tube feeding. Nasoenteral feeding tubes are usually placed endoscopically by gastroenterologists, but this procedure is relatively cumbersome for patients and labor-intensive for hospital staff.

  9. Cost-effectiveness of transcatheter aortic valve replacement compared with surgical aortic valve replacement in high-risk patients with severe aortic stenosis: results of the PARTNER (Placement of Aortic Transcatheter Valves) trial (Cohort A).

    Science.gov (United States)

    Reynolds, Matthew R; Magnuson, Elizabeth A; Lei, Yang; Wang, Kaijun; Vilain, Katherine; Li, Haiyan; Walczak, Joshua; Pinto, Duane S; Thourani, Vinod H; Svensson, Lars G; Mack, Michael J; Miller, D Craig; Satler, Lowell E; Bavaria, Joseph; Smith, Craig R; Leon, Martin B; Cohen, David J

    2012-12-25

    The aim of this study was to evaluate the cost-effectiveness of transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (AVR) for patients with severe aortic stenosis and high surgical risk. TAVR is an alternative to AVR for patients with severe aortic stenosis and high surgical risk. We performed a formal economic analysis based on cost, quality of life, and survival data collected in the PARTNER A (Placement of Aortic Transcatheter Valves) trial in which patients with severe aortic stenosis and high surgical risk were randomized to TAVR or AVR. Cumulative 12-month costs (assessed from a U.S. societal perspective) and quality-adjusted life-years (QALYs) were compared separately for the transfemoral (TF) and transapical (TA) cohorts. Although 12-month costs and QALYs were similar for TAVR and AVR in the overall population, there were important differences when results were stratified by access site. In the TF cohort, total 12-month costs were slightly lower with TAVR and QALYs were slightly higher such that TF-TAVR was economically dominant compared with AVR in the base case and economically attractive (incremental cost-effectiveness ratio economically dominated by AVR in the base case and economically attractive in only 7.1% of replicates. In the PARTNER trial, TAVR was an economically attractive strategy compared with AVR for patients suitable for TF access. Future studies are necessary to determine whether improved experience and outcomes with TA-TAVR can improve its cost-effectiveness relative to AVR. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. Development of a High Performance Spacer Grid

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kee Nam; Song, K. N.; Yoon, K. H. (and others)

    2007-03-15

    A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 18 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates 16 are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models.

  11. Development of a High Performance Spacer Grid

    International Nuclear Information System (INIS)

    Song, Kee Nam; Song, K. N.; Yoon, K. H.

    2007-03-01

    A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 18 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates 16 are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models

  12. A comparative study of surgical drain placement and the use of kinesiologic tape to reduce postoperative morbidity after third molar surgery.

    Science.gov (United States)

    Genc, Aysenur; Cakarer, Sirmahan; Yalcin, Basak Keskin; Kilic, Beril Berivan; Isler, Sabri Cemil; Keskin, Cengizhan

    2018-04-19

    Our aim was to compare the effects of the surgical drain and kinesiotape applications on postoperative morbidity after mandibular third molar surgery in a split-mouth study design. A single-centre, split-mouth study was performed in 23 patients who needed surgical removal of bilateral mandibular third molars. Each patient was treated with a drain tube on one side of the mandible and Kinesio tape (KT) on the contralateral side. Swelling was significantly greater in the KT group than in the drain group throughout the study period. The groups did not differ significantly in the amount of trismus at any time point. The Visual Analogue Scale (VAS)-measured pain intensity was significantly lower in the drainage group. Patients with KT had greater postoperative discomfort than those with a drain tube. All patients were generally satisfied with their treatments. Although both treatments were useful, a surgical drain was significantly more effective at reducing swelling and pain intensity than Kinesio tape. The effects of both on trismus were similar.

  13. Spacer for supporting fuel element boxes

    International Nuclear Information System (INIS)

    Wild, E.

    1979-01-01

    A spacer plate unit arranged externally on each side and at a predetermined level of a polygonal fuel element box for mutually supporting, with respect to one another, a plurality of the fuel element boxes forming a fuel element bundle, is formed of a first and a second spacer plate part each having the same length and the same width and being constituted of unlike first and second materials, respectively. The first and second spacer plate parts of the several spacer plate units situated at the predetermined level are arranged in an alternating continuous series when viewed in the peripheral direction of the fuel element box, so that any two spacer plate units belonging to face-to-face oriented sides of two adjoining fuel element boxes in the fuel element bundle define interfaces of unlike materials

  14. Private placements

    International Nuclear Information System (INIS)

    Bugeaud, G. J. R.

    1998-01-01

    The principles underlying private placements in Alberta, and the nature of the processes employed by the Alberta Securities Commission in handling such transactions were discussed. The Alberta Securities Commission's mode of operation was demonstrated by the inclusion of various documents issued by the Commission concerning (1) special warrant transactions prior to listing, (2) a decision by the Executive Director refusing to issue a receipt for the final prospectus for a distribution of securities of a company and the reasons for the refusal, (3) the Commission's decision to interfere with the Executive Director's decision not to issue a receipt for the final prospectus, with full citation of the Commission's reasons for its decision, (4) and a series of proposed rules and companion policy statements regarding trades and distributions outside and in Alberta. Text of a sample 'short form prospectus' was also included

  15. Application of spacer fabrics in composite production

    OpenAIRE

    Mecit, Diren; , Arzu Marmaralı

    2012-01-01

    Developments in the field of textile reinforced composites have been increasing in the last several years. In the first developed composite materials, fibers were used as reinforcement element. Textile materials such as staple fibers, bands, filament yarns, cables and two dimensional textiles are widely used as reinforcement elements in composite materials. Spacer fabrics consist of two outer surfaces and a connection layer between those outer surfaces. Spacer fabrics can be classified in the...

  16. Application of spacer fabrics in composite production

    OpenAIRE

    Mecit, Diren; -, Arzu Marmaralı

    2014-01-01

    Developments in the field of textile reinforced composites have been increasing in the last several years. In the first developed composite materials, fibers were used as reinforcement element. Textile materials such as staple fibers, bands, filament yarns, cables and two dimensional textiles are widely used as reinforcement elements in composite materials. Spacer fabrics consist of two outer surfaces and a connection layer between those outer surfaces. Spacer fabrics can be classified in the...

  17. Sediment Placement Areas 2012

    Data.gov (United States)

    California Department of Resources — Dredge material placement sites (DMPS), including active, inactive, proposed and historical placement sites. Dataset covers US Army Corps of Engineers San Francisco...

  18. Biarticular total femur spacer for massive femoral bone loss: the mobile solution for a big problem

    Directory of Open Access Journals (Sweden)

    Pablo Sanz-Ruiz, PhD, MD

    2018-03-01

    Full Text Available Bone cement spacers loaded with antibiotic are the gold standard in septic revision. However, the management of massive bone defects constitutes a surgical challenge, requiring the use of different nails, expensive long stems, or cement-coated tumor prostheses for preparing the spacer. In most cases, the knee joint must be sacrificed. We describe a novel technique for preparing a biarticular total femur spacer with the help of a trochanteric nail coated with antibiotic loaded cement, allowing mobility of the hip and knee joints and assisted partial loading until second step surgery. This technique is helpful to maintain the length of the leg, prevent soft tissue contracture, and help eradicate the infection preserving the patient comfort and autonomy while waiting to receive total femoral replacement.

  19. Biarticular total femur spacer for massive femoral bone loss: the mobile solution for a big problem.

    Science.gov (United States)

    Sanz-Ruiz, Pablo; Calvo-Haro, Jose Antonio; Villanueva-Martinez, Manuel; Matas-Diez, Jose Antonio; Vaquero-Martín, Javier

    2018-03-01

    Bone cement spacers loaded with antibiotic are the gold standard in septic revision. However, the management of massive bone defects constitutes a surgical challenge, requiring the use of different nails, expensive long stems, or cement-coated tumor prostheses for preparing the spacer. In most cases, the knee joint must be sacrificed. We describe a novel technique for preparing a biarticular total femur spacer with the help of a trochanteric nail coated with antibiotic loaded cement, allowing mobility of the hip and knee joints and assisted partial loading until second step surgery. This technique is helpful to maintain the length of the leg, prevent soft tissue contracture, and help eradicate the infection preserving the patient comfort and autonomy while waiting to receive total femoral replacement.

  20. Immediate Implant Placement: Report of Case Series

    Directory of Open Access Journals (Sweden)

    Koray M.

    2015-07-01

    Full Text Available Objective: The aim of this study was to evaluate the outcome of immediate postextraction implant placement. Immediate placement of dental implants have been claimed of the potential advantages such as reductions in the number of surgical interventions, a shorter treatment time, an ideal 3-dimensional implant positioning, the presumptive preservation of alveolar bone at the site of the tooth extraction and soft tissue aesthetics.

  1. High corrosion-resistant fuel spacers

    International Nuclear Information System (INIS)

    Yoshida, Toshimi; Takase, Iwao; Ikeda, Shinzo; Masaoka, Isao; Nakajima, Junjiro.

    1986-01-01

    Purpose: To enable manufacturing BWR fuel spacers by prior-art production process, using a zirconium-base alloy having very excellent corrosion resistance. Method: A highly improved nodular-resistant, corrosion-resistant zirconium alloy is devised by adding a slight amount of niobium, titanium and vanadium to zircaloy, of which fuel spacers are produced. That is, there can be obtained an alloy having much more excellent nodular resistance than conventional zircaloy, and free from a large change in plasticity, workability, and weldability, by adding to zirconium about 1.5 % of tin, about 0.15 % of iron, about 0.05 % of chromium, about 0.05 % of nickel, and 0.05 to 0.5 % of at least one or two kinds of niobium, titanium and vanadium. Using this zirconium-base alloy can manufacture fuel spacers by the same manufacturing process, thus improving economy and reliability. (Kamimura, M.)

  2. Fouling Resilient Perforated Feed Spacers for Membrane Filtration

    KAUST Repository

    Kerdi, Sarah

    2018-04-24

    The improvement of feed spacers with optimal geometry remains a key challenge for spiral-wound membrane systems in water treatment due to their impact on the hydrodynamic performance and fouling development. In this work, novel spacer designs are proposed by intrinsically modifying cylindrical filaments through perforations. Three symmetric perforated spacers (1-Hole, 2-Hole, and 3-Hole) were in-house 3D-printed and experimentally evaluated in terms of permeate flux, feed channel pressure drop and membrane fouling. Spacer performance is characterized and compared with standard no perforated (0-Hole) design under constant feed pressure and constant feed flow rate. Perforations in the spacer filaments resulted in significantly lowering the net pressure drop across the spacer filled channel. The 3-Hole spacer was found to have the lowest pressure drop (50% - 61%) compared to 0-Hole spacer for various average flow velocities. Regarding permeate flux production, the 0-Hole spacer produced 5.7 L.m-2.h-1 and 6.6 L.m-2.h-1 steady state flux for constant pressure and constant feed flow rate, respectively. The 1-Hole spacer was found to be the most efficient among the perforated spacers with 75% and 23% increase in permeate production at constant pressure and constant feed flow, respectively. Furthermore, membrane surface of 1-Hole spacer was found to be cleanest in terms of fouling, contributing to maintain higher permeate flux production. Hydrodynamic understanding of these perforated spacers is also quantified by performing Direct Numerical Simulation (DNS). The performance enhancement of these perforated spacers is attributed to the formation of micro-jets in the spacer cell that aided in producing enough unsteadiness/turbulence to clean the membrane surface and mitigate fouling phenomena. In the case of 1-Hole spacer, the unsteadiness intensity at the outlet of micro-jets and the shear stress fluctuations created inside the cells are higher than those observed with

  3. Report on reflood experiment of grid spacer effect

    International Nuclear Information System (INIS)

    Sugimoto, Jun; Murao, Yoshio

    1984-07-01

    Experiments were performed in order to clarify the effect of grid spacers on reflood heat transfer in PWR-LOCA. The flow pattern, the thermal responses and the water accumulation near the grid spacer were investigated by shifting the grid spacer at the midplane of the simulated core. Also tested is the effect of the thickness of the grid spacer wall on the reflood behavior. The heat transfer coefficient before the quenching was about 20 to 50 percent higher just above the grid spacer than just below the grid spacer. The decrease of the droplet diameter due to the grid spacer was observed in the droplet dispersed flow regime. In the slug flow regime, the grid spacer was rewetted early in the reflood transient and the increased water accumulation near the grid spacer was observed. Hence, the heat transfer enhancement due to the grid spacer is mainly attributed to the increased interfacial surface area of droplets in the dispersed flow and also to the increased film boiling heat transfer in the slug flow. The heat transfer enhancement tended to be larger with the larger thickness of the grid spacer. The simple model was developed for both the dispersed flow and slug flow regimes based on the present experimental results. The thermohydraulic behavior near the grid spacer was well calculated with the developed model. The further detailed information, however, is required for the improvement and the verification of the grid spacer model. (author)

  4. Nuclear reactor fuel assembly spacer grids

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1977-01-01

    Designs of nuclear reactor fuel assembly spacer grids for supporting and spacing fuel elements are described which do not utilize resilient grid plate protrusions in the peripheral band but retain the advantages inherent in the combination resilient and rigid protrusion cells. (U.K.)

  5. ADVANCED DENTAL IMPLANT PLACEMENT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Alex M. GREENBERG

    2017-12-01

    Full Text Available The availability of in office Cone Beam CT (CBCT scanners, dental implant planning software, CAD CAM milling, and rapid printing technologies allow for the precise placement of dental implants and immediate prosthetic temporization. These technologies allow for flapless implant placement, or open flap bone reduction for “All on 4” techniques with improved preoperative planning and intraoperative performance. CBCT permits practitioners in an office setting with powerful diagnostic capabilities for the evaluation of bone quality and quantity, as well as dental and osseous pathology essential for better informed dental implant treatment. CBCT provides the convenience of in office imaging and decreased radiation exposure. Rapid printing technologies provide decreased time and high accuracy for bone model and surgical guide fabrication.

  6. Pressure Drop Test of Hybrid Mixing Vane Spacer Grid

    Energy Technology Data Exchange (ETDEWEB)

    Oh, D. S.; Chang, S. K.; Kim, B. D.; Chun, S. Y.; Chun, T. H

    2007-08-15

    The pressure loss test has been accomplished in the test section containing 5x5 rod bundle with a length of 2 m including 3 spacer grids. The test has been performed for the 5 kinds of spacer grids to compare the pressure loss characteristics: 1. Plain spacer grid which has the same body of the Hybrid but without vane (Plain), 2. Hybrid Vane spacer grid (Hybrid), 3. Hybrid-SC spacer grid which is constructed with coined, chamfered strip and is fabricated by spot welding, 4. Hybrid-LC spacer grid which is constructed with coined, chamfered strip and is fabricated by line welding along intersection line, 5. Westinghouse spacer grid with split vane (Plus-7). The pressure loss coefficient of the Plain, Hybrid, Hybrid-SC, Hybrid-LC, and Plus-7 spacer grid is 0.93, 1.15, 1.02, 1.04, and 1.08, respectively.

  7. Boat boarding ladder placement

    Science.gov (United States)

    1998-04-01

    Presented in three volumes; 'Boat Boarding Ladder Placement,' which explores safety considerations including potential for human contact with a rotating propeller; 'Boat Handhold Placement,' which explores essential principles and methods of fall con...

  8. Hydraulic Design Criteria for Spacer Grids of Nuclear Fuel Element

    International Nuclear Information System (INIS)

    Juanico, Luis; Brasnarof, Daniel

    2000-01-01

    In this paper a hydraulic model for calculating the pressure drop on the CARA spacer grids is extended.This model is validated and feedback from experimental hydraulic test performed in a low pressure loop.The importance of the spacer grid geometric parameter (that is, its thickness and length, the number and kind of their fix spacer), developing hydraulic design criteria for spacer grid on fuel element

  9. A non-electrostatic spacer for aerosol delivery

    DEFF Research Database (Denmark)

    Bisgaard, H; Anhøj, J; Klug, B

    1995-01-01

    A pear shaped non-electrostatic spacer, composed of steel with a volume of 250 ml and equipped with a facemask containing integrated inlet and outlet valves for inspiration and expiration, was compared with three plastic spacers. The plastic spacers were primed with repeated puffs from a budesonide...

  10. A Placement Advisory Test

    Science.gov (United States)

    Hughes, Chris

    2010-01-01

    The primary method of placement at Portland CC (PCC) is the Compass Placement test. For the most part, students are placed correctly, but there are cases when students feel that they have been placed too low. In such cases we use our newly created Placement Advisory Test (PAT) to help us place them appropriately. (Contains 2 figures.)

  11. Autoclaved metal-on-cement spacer versus static spacer in two-stage revision in periprosthetic knee infection

    Directory of Open Access Journals (Sweden)

    Yu-Pin Chen

    2016-01-01

    Conclusions: The autoclaved metal-on-cement spacer is an effective and simple method for two-stage re-implantation of a periprosthetic knee infection. Through this spacer, the good interim ROM can be achieved without the additional cost of prefabricated molds or new polyethylene tibial inserts. In addition, ROM after re-implantation is better than that with static spacers.

  12. Heterogeneous diversity of spacers within CRISPR

    Science.gov (United States)

    Deem, Michael; He, Jiankui

    2011-03-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) in bacterial and archaeal DNA have recently been shown to be a new type of anti-viral immune system in these organisms. We here study the diversity of spacers in CRISPR under selective pressure. We propose a population dynamics model that explains the biological observation that the leader-proximal end of CRISPR is more diversified and the leader-distal end of CRISPR is more conserved. This result is shown to be in agreement with recent experiments. Our results show that the CRISPR spacer structure is influenced by and provides a record of the viral challenges that bacteria face. 1) J. He and M. W. Deem, Phys. Rev. Lett. 105 (2010) 128102

  13. Honeycomb spacer crush stength test results

    Energy Technology Data Exchange (ETDEWEB)

    Leader, D.R.

    1993-09-15

    This report discusses aluminum honeycomb spacers, which are used as an energy absorbent material in shipping packages for off site shipment of radioactive materials and which were ordered in two crush strengths, 1,000 psi and 2,000 psi for use in drop tests requested by the Packaging and Transportation group as part of the shipping container rectification process. Both the group as part of the shipping container rectification process. Both the vendor and the SRTC Materials Laboratory performed crush strength measurements on test samples made from the material used to fabricate the actual spacers. The measurements of crush strength made in the SRTC Materials Laboratory are within 100 psi of the measurements made by the manufacturer for all samples tested and all test measurements are within 10% of the specified crush strength, which is acceptable to the P&T group for the planned tests.

  14. Generic assessment of tight-fitting annulus spacer mobility

    International Nuclear Information System (INIS)

    Robertson, J.; Micuda, L.; Van Den Brekel, N.

    2006-01-01

    This paper provides a generic assessment of the mobility of tight-fitting fuel channel annulus spacers in OPG and Bruce Power nuclear units. This assessment is applicable to all tight-fitting annulus spacers, including those used in the original fuel channel installation (Darlington Units 1-4, retubed Pickering Units 1-4, and Bruce Unit 8) and as a result of single fuel channel replacements (SFCR) (Pickering Units 5-8, Bruce Units 3-7). Tight-fitting annulus spacers were designed not to move. Pressure tube to calandria tube contact analyses, and the associated blister susceptibility assessments, have assumed that these tight-fitting spacers remain at the pre-service installed locations. Given the importance of this assumption, the technical basis for the expectation that tight-fitting annulus spacers do not move significantly from their pre-service locations, relative to the pressure tube, was reviewed in detail. The review also assessed the inspection data, comparing spacer locations from in-service and pre-service inspections. The review has concluded that tight-fitting spacers do not move sufficiently to necessitate a postulated spacer movement in fuel channel contact analyses. The paper describes the background of this issue, briefly reviews the experimental programs used to qualify the positional stability of the tight-fitting spacer design, and evaluates the current database of in-service spacer location inspection information to demonstrate that no significant movement relative to the pressure tube has been observed. (author)

  15. The Effect of Subluxation of Articulating Antibiotic Spacers on Bone Defects and Degree of Constraint in Revision Knee Arthroplasty.

    Science.gov (United States)

    Lau, Adrian C K; Howard, James L; Macdonald, Steven J; Teeter, Matthew G; Lanting, Brent A

    2016-01-01

    This study investigated whether subluxation of articulating antibiotic spacers is associated with the bone defects found and constraint required when re-implanting the knee arthroplasty components. Staged revisions for infections of primary total knee arthroplasties between 2004 and 2012 were examined. Radiographic sagittal and coronal subluxations of 72 knees were measured prior to second stage revision. Coronal subluxation was found to be associated with increased requirement for constrained knee systems (P<0.035). Sagittal subluxation was associated with greater tibia bone defects (P<0.037). Careful surgical technique and monitoring of articulating spacers should be done to avoid subluxation after stage 1 revision. If subluxation of the articulating spacer is present, constrained revision knee systems as well as augments should be available at time of re-implantation. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Sequence and structure correlation of human ribosomal transcribed spacers.

    Science.gov (United States)

    Gonzalez, I L; Chambers, C; Gorski, J L; Stambolian, D; Schmickel, R D; Sylvester, J E

    1990-03-05

    We report the sequences of the transcribed spacers of human rRNA that now allow us to piece together the entire primary transcript sequence of approximately 13.3 x 10(3) base-pairs. Comparison of transcribed spacer sequences with those of variable regions of rRNA and with those of the non-transcribed spacers supports the hypothesis that the variable regions are descended from transcribed spacers. Nucleotide sequence-derived secondary structures for the 5' external transcribed spacer and for internal transcribed spacers 1 and 2 match both the sizes and shapes of the structures that were visualized 15 years ago on electron micrographs. Parts of these structures are conserved in mammals and may be related to transcript processing.

  17. A non-electrostatic spacer for aerosol delivery

    DEFF Research Database (Denmark)

    Bisgaard, H; Anhøj, J; Klug, B

    1995-01-01

    pressurised metered dose inhaler (p-MDI) to minimise the electrostatic charge on the plastic. The procedure prolonged the half life (t1/2) of the aerosol in the Nebuhaler from nine to 32 seconds. A normal cleaning procedure reduced the aerosol t1/2 back to baseline. The t1/2 of the aerosol in the metal spacer...... younger than 4 years. The improved dose delivery from the small volume non-electrostatic spacer is probably related to the non-electrostatic spacer material and the valves which assured unidirectional airflow from the spacer without adding any dead space in the inspiratory channel. The non-electro-static...

  18. Development of structural technology for a high performance spacer grid

    International Nuclear Information System (INIS)

    Song, Kee Nam; Kim, H. K.; Kang, H. S.

    2003-03-01

    A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 14 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates six are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models

  19. Nuclear reactor spring strip grid spacer

    International Nuclear Information System (INIS)

    Patterson, J.F.; Flora, B.S.

    1980-01-01

    An improved and novel grid spacer was developed for use in nuclear reactor fuel assemblies. It is comprised of a series of intersecting support strips and a peripheral support band attached to the ends of the support strips. Each of the openings into which the fuel element is inserted has a number of protruding dimples and springs extending in different directions. The dimples coact with the springs to secure the fuel rods in the openings. Compared with previous designs, this design gives more positive alignment of the support stips while allowing greater flexibility to counterbalance the effects of thermal expansion. The springs are arranged in alternating directions so that the reaction forces tend to counterbalance each other, which in turn minimizes the reaction loads on the supporting structure. (D.N.)

  20. Salvage of Infected Nasal Reconstruction with a Polymethyl Methacrylate Spacer.

    Science.gov (United States)

    Cavadas, Pedro C; Thione, Alessandro; Pacheco, Yvan D

    2017-07-01

    Total nasal reconstruction is a challenging multistage procedure. Infections can destroy the cartilage framework and seriously compromise the result. The use of polymethyl methacrylate with antibiotics as a spacer has been described in the treatment of skeletal infections. Using this same principle, the use of a polymethyl methacrylate with antibiotics spacer for an infected nasal reconstruction is reported in a clinical case.

  1. Intergenic spacer length variants in Old Portuguese bread wheat ...

    Indian Academy of Sciences (India)

    2011-08-19

    Aug 19, 2011 ... and the termination of the transcription (McMullen et al. 1986; Suzuki et al. 1996; Abdulova and Ananiev 2003). The non-coding rDNA spacers (IGS and the internal transcribed spacer (ITS)) could be substantially variable in size due to differences in the number of repetitive elements among the closely ...

  2. ATLAS barrel hadron tile calorimeter: spacers plates mass production

    International Nuclear Information System (INIS)

    Artikov, A.M.; Budagov, Yu.A.; Khubua, J.

    1999-01-01

    In this article we expose the main problems of the mass production of the so-called 'spacer plates' for the ATLAS Barrel Hadron Tile Calorimeter. We describe all practical solutions of these problems. Particularly we present the measurement procedures and calculation schemes we used for the spacers dimensions determination. The results of the calculations are presented

  3. PCR-Internal Transcribed Spacer (ITS) genes sequencing and ...

    African Journals Online (AJOL)

    Methods: DNA extraction, purification, amplification and sequencing of Internal Transcribed Spacer (ITS) genes were per- formed using ... Keywords: Internal transcribed spacer genes, phylogenetic, genetic relationship, clinical and environmental fungi, HIV-TB. ... Nigeria. An Ethical clearance was obtained from the Eth-.

  4. CFD application to advanced design for high efficiency spacer grid

    International Nuclear Information System (INIS)

    Ikeda, Kazuo

    2014-01-01

    Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

  5. ESL Placement and Schools

    Science.gov (United States)

    Callahan, Rebecca; Wilkinson, Lindsey; Muller, Chandra; Frisco, Michelle

    2010-01-01

    In this study, the authors explore English as a Second Language (ESL) placement as a measure of how schools label and process immigrant students. Using propensity score matching and data from the Adolescent Health and Academic Achievement Study and the National Longitudinal Study of Adolescent Health, the authors estimate the effect of ESL placement on immigrant achievement. In schools with more immigrant students, the authors find that ESL placement results in higher levels of academic performance; in schools with few immigrant students, the effect reverses. This is not to suggest a one-size-fits-all policy; many immigrant students, regardless of school composition, generational status, or ESL placement, struggle to achieve at levels sufficient for acceptance to a 4-year university. This study offers several factors to be taken into consideration as schools develop policies and practices to provide immigrant students opportunities to learn. PMID:20617111

  6. Immediate Intrauterine Device Insertion Following Surgical Abortion.

    Science.gov (United States)

    Patil, Eva; Bednarek, Paula H

    2015-12-01

    Placement of an intrauterine device (IUD) immediately after a first or second trimester surgical abortion is safe and convenient and decreases the risk of repeat unintended pregnancy. Immediate postabortion IUD placement is not recommended in the setting of postprocedure hemorrhage, uterine perforation, infection, or hematometra. Otherwise, there are few contraindications to IUD placement following surgical abortion. Sexually transmitted infection screening should follow US Centers for Disease Control and Prevention guidelines. No additional antibiotics are needed beyond those used for the abortion. Placing immediate postabortion IUDs makes highly-effective long-acting reversible contraception more accessible to women. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Grid spacers for use in a nuclear fuel assembly

    International Nuclear Information System (INIS)

    Kuwako, Akira.

    1987-01-01

    Purpose: To obtain spacers capable of reducing the pressure loss by enlarging coolant flow channels when the fuel temperature is high, while capable of reliably maintaining the fuel pins with no vibrations when the fuel temperature is low. Constitution: This invention concerns grid spacers for constituting fuel assemblies for use in water cooled reactors. Memory shape alloys are disposed at least a portion of a spacer element that takes such a shape as urging the pin when the fuel temperature is low, while enlarging the coolant flow channel to reduce the pressure loss when the fuel temperature is high. (Ikeda, J.)

  8. Product Placement in Cartoons

    Directory of Open Access Journals (Sweden)

    Irena Oroz Štancl

    2014-06-01

    Full Text Available Product placement is a marketing approach for integrating products or services into selected media content. Studies have shown that the impact of advertising on children and youth are large, and that it can affect their preferences and attitudes. The aim of this article is to determine the existing level of product placement in cartoons that are broadcast on Croatian television stations. Content analysis of cartoons in a period of one month gave the following results: in 30% of cartoons product placement was found; most product placement were visual ads, in 89%, however, auditory product placement and plot connection was also found. Most ads were related to toys and it is significant that even 65% of cartoons are accompanied by a large amount of products available on the Croatian market. This is the result of two sales strategies: brand licensing (selling popular cartoon characters to toys, food or clothing companies and cartoon production based on existing line of toys with the sole aim of making their sales more effective.

  9. Analysis of US patents on spacer grids

    International Nuclear Information System (INIS)

    Kim, Hyung Kyu; Song, Kee Nam; Yoon, Kyung Ho; Kang, Hong Seok; Kim, Hyung Kyu; Jeon, Tae Hyun; Oh, Dong Seok; In, Wang Ki; Bang, Jae Keun; Oh, Seung Eun; Seo, Jeong Min; Lee, Jin Seok; Park, Seong Keun

    1997-06-01

    The total of 137 US patents on spacer grids patented from 1968 through 1993 are analyzed and summarized. Database is constituted with designing the appropriate fields by which each patent can be identified. The fields consist of patent number, inventor, assignee, date of patent, title and major foci of the patent. The major foci are again classified by detailed subjects such as the fretting failure and fuel rod support-related, the strength-related, the fabrication-related as for mechanical subjects, while the cooling performance-related and the pressure drop-related as for thermal-hydraulic one. The 92% of the patents analyzed were issued form nuclear companies of USA, France and Germany. Among the patents dealing with mechanical subjects, the fretting failure and fuel rod support-related is more than the pressure drop-related among the patents of thermal-hydraulic subjects. The number of patents issued from Japan ranks just after Germany i.e., the 4th country. It is thought that much concern as well as investment should be increased in this field, the patent of nuclear components. (author). 2 tabs., 5 figs

  10. Abortion - surgical

    Science.gov (United States)

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... Surgical abortion involves dilating the opening to the uterus (cervix) and placing a small suction tube into the uterus. ...

  11. Surface plasmon resonance in electrodynamically coupled Au NPs monolayer/dielectric spacer/Al film nanostructure: tuning by variation of spacer thickness

    Science.gov (United States)

    Yeshchenko, Oleg A.; Kozachenko, Viktor V.; Liakhov, Yuriy F.; Tomchuk, Anastasiya V.; Haftel, Michael; Pinchuk, Anatoliy O.

    2017-10-01

    Effects of plasmonic coupling between metal nanoparticles and thin metal films separated by thin dielectric film-spacers have been studied by means of light extinction in three-layer planar Au NPs monolayer/dielectric (shellac) film/Al film nanostructure. The influence of coupling on the spectral characteristics of the Au NPs SPR extinction peak has been analyzed with spacer thickness, varied from 3 to 200 nm. The main observed features are a strong red shift (160 nm), and non-monotonical behavior of the magnitude and width of Au NPs SPR, as the spacer thickness decreased. The appearance of an intensive gap mode peak was observed at a spacer thickness smaller than approximately 30 nm, caused by the hybridization of the Au NPs SPR mode and gap mode in the presence of the Al film. Additionally, the appreciable enhancement (5.6 times) of light extinction by the Au NPs monolayer in the presence of Al film has been observed. A certain value of dielectric spacer thickness (70 nm) exists at which such enhancement is maximal.

  12. Surface-Tethered Iterative Carbohydrate Synthesis (STICS): A spacer study

    Science.gov (United States)

    Ganesh, N. Vijaya; Fujikawa, Kohki; Tan, Yih Horng; Nigudkar, Swati S.

    2013-01-01

    Comparative study of STICS using HPLC-assisted experimental set-up clearly demonstrated benefits of using longer spacer-anchoring systems. The use of mixed self-assembled monolayers helps to provide the required space for glycosylation reaction around the immobilized glycosyl acceptor. Both extension of the spacer length and using mixed self-assembled monolayers help to promote reaction and the beneficial effects may include moving the glycosyl acceptor further out into solution and providing additional conformational flexibility. It is possible that surface-immobilized glycosyl acceptors with a longer spacer (C8-O-C8)-lipoic acid have a higher tendency to mimic a solution-phase reaction environment than that of acceptors with shorter spacers. PMID:23822088

  13. Salvage of Infected Nasal Reconstruction with a Polymethyl Methacrylate Spacer

    Directory of Open Access Journals (Sweden)

    Pedro C. Cavadas, MD, PhD

    2017-07-01

    Full Text Available Summary:. Total nasal reconstruction is a challenging multistage procedure. Infections can destroy the cartilage framework and seriously compromise the result. The use of polymethyl methacrylate with antibiotics as a spacer has been described in the treatment of skeletal infections. Using this same principle, the use of a polymethyl methacrylate with antibiotics spacer for an infected nasal reconstruction is reported in a clinical case.

  14. Bioinformatics analyses of Shigella CRISPR structure and spacer classification.

    Science.gov (United States)

    Wang, Pengfei; Zhang, Bing; Duan, Guangcai; Wang, Yingfang; Hong, Lijuan; Wang, Linlin; Guo, Xiangjiao; Xi, Yuanlin; Yang, Haiyan

    2016-03-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are inheritable genetic elements of a variety of archaea and bacteria and indicative of the bacterial ecological adaptation, conferring acquired immunity against invading foreign nucleic acids. Shigella is an important pathogen for anthroponosis. This study aimed to analyze the features of Shigella CRISPR structure and classify the spacers through bioinformatics approach. Among 107 Shigella, 434 CRISPR structure loci were identified with two to seven loci in different strains. CRISPR-Q1, CRISPR-Q4 and CRISPR-Q5 were widely distributed in Shigella strains. Comparison of the first and last repeats of CRISPR1, CRISPR2 and CRISPR3 revealed several base variants and different stem-loop structures. A total of 259 cas genes were found among these 107 Shigella strains. The cas gene deletions were discovered in 88 strains. However, there is one strain that does not contain cas gene. Intact clusters of cas genes were found in 19 strains. From comprehensive analysis of sequence signature and BLAST and CRISPRTarget score, the 708 spacers were classified into three subtypes: Type I, Type II and Type III. Of them, Type I spacer referred to those linked with one gene segment, Type II spacer linked with two or more different gene segments, and Type III spacer undefined. This study examined the diversity of CRISPR/cas system in Shigella strains, demonstrated the main features of CRISPR structure and spacer classification, which provided critical information for elucidation of the mechanisms of spacer formation and exploration of the role the spacers play in the function of the CRISPR/cas system.

  15. Surgical Templates for Dental Implant Positioning; Current ...

    African Journals Online (AJOL)

    also dictates to the surgeon about the implant body placement that offers the best ... surgical template. The requirements are more relevant than the. Surgical Templates for Dental Implant Positioning;. Current Knowledge and Clinical Perspectives. Mohammed Zaheer Kola ..... A risk of damage to vital anatomical structures.

  16. Surgical Templates for Dental Implant Positioning; Current ...

    African Journals Online (AJOL)

    to the surgeon the implant body placement that offers the best combination of (1) support for the repetitive forces of occlusion, (2) esthetics, (3) hygiene requirements.[2,3]. Literature evidenced various methods of fabrication for the surgical template. The requirements are more relevant than the. Surgical Templates for Dental ...

  17. The potential of standard and modified feed spacers for biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The impact of feed spacers on initial feed channel pressure (FCP) drop, FCP increase and biomass accumulation has been studied in membrane fouling simulators using feed spacers applied in commercially available nanofiltration and reverse osmosis spiral wound membrane modules. All spacers had a similar geometry.Our studies showed that biofouling was not prevented by (i) variation of spacer thickness, (ii) feed spacer orientation, (iii) feed spacer coating with silver, copper or gold and (iv) using a biostatic feed spacer. At constant feed flow, a lower FCP and FCP increase were observed for a thicker feed spacer. At constant linear flow velocity, roughly the same FCP development and biomass accumulation were found irrespective of the feed spacer thickness: hydrodynamics and substrate load were more important for development and impact of biofouling than the thickness of currently applied spacers. Use of biostatic and metal coated spacers were not effective for biofouling control. The same small reduction of biofouling rate was observed with copper and silver coated spacers as well as uncoated 45° rotated spacers.The studied modified spacers were not effective for biofouling prevention and control. The impact of biofouling on FCP increase was reduced significantly by a lower linear flow velocity, while spacer orientation and spacer thickness in membrane modules had a smaller but still significant effect. © 2012 Elsevier B.V.

  18. Acute toxicity after a diverting stoma and spacer prior to chemoradiation in locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Voort van Zyp, Jochem R.N. van der; Ceha, Heleen M.; Niehe, Valerie; Marinelli, Andreas W.K.S.; Putter, Hein; Marijnen, Corrie A.M.

    2015-01-01

    Background and purpose: Chemoradiotherapy (CRT) followed by surgery is the standard of care for locally advanced rectal cancer (LARC). For grade ⩾3 acute diarrhea there is a relationship between dose and irradiated small bowel volume. The aim of this study was to evaluate whether combined placement of a diverting stoma and sigmoid spacer (DSSS) led to reduced irradiated small bowel volume and less grade ⩾3 acute diarrhea in the treatment of LARC. Materials/methods: Between 2003 and 2010, 54 of 189 LARC patients treated with CRT in two institutions had a DSSS prior to CRT. Data on patient and treatment characteristics and outcomes were collected retrospectively. Delineation of small bowel was performed with planning CT-scans. CTCAE version 4.0 was used for acute toxicity. Results: Patients with a DSSS had significantly less small bowel volume irradiated up to doses of 20 Gy. This difference was not observed for the higher dose levels. CRT induced grade ⩾3 acute diarrhea was not different between the two groups (8.3% vs. 12.8%; p = 0.41). Conclusion: DSSS is not clearly beneficial to reduce grade ⩾3 acute diarrhea, and it must be considered whether placement of a DSSS is justified for this purpose

  19. [Accuracy of computer-guided implant placement and influencing factors].

    Science.gov (United States)

    Jinmeng, Li; Guomin, Ou

    2017-02-01

    Digital technology is a new trend in implant dentistry and oral medical technology. Stereolithographic surgical guides, which are computer-guided implant placement, have been introduced gradually to the market. Surgeons are attracted to this approach because of it features visualized preoperative planning, simple surgical procedure, flapless implant, and immediate restoration. However, surgeons are concerned about the accuracy and complications of this approach. This review aims to introduce the classification of computer-guided implant placement. The advantages, disadvantages, and accuracy of this approach are also analyzed. Moreover, factors that may affect the outcomes of computer-guided implant placement are determined. Results will provide a reference to surgeons regarding the clinical application of this approach.

  20. Impact of spacer thickness on biofouling in forward osmosis.

    Science.gov (United States)

    Valladares Linares, R; Bucs, Sz S; Li, Z; AbuGhdeeb, M; Amy, G; Vrouwenvelder, J S

    2014-06-15

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46 mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Numerical analysis of the spacer grids' compression strength

    Energy Technology Data Exchange (ETDEWEB)

    Schettino, C.F.M.; Gouvea, J.P.; Medeiros, N., E-mail: carlosschettino@inb.gov.br, E-mail: jpg@metal.eeimvr.uff.br [Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil). Programa de Engenharia Metalurgica

    2013-07-01

    Among the components of the fuel assembly, the spacer grids play an important structural role during the energy generation process, mainly for their requirement to have enough structural strength to withstand lateral impact loads, due to fuel assembly shipping/handling and due to forces outcome from postulated accidents (earthquake and LOCA). This requirement ensures a proper geometry for cooling and for guide thimble straightness in the fuel assembly. In this way, the understanding of the macroscopic mechanical behavior of this component becomes essential even to any subsequent geometrical modifications to optimize the flue assemblies' structural behavior. In the present work, three-dimensional finite element models destined to provide consistent predictions of 16X16-type spacer grids lateral strength were proposed. Firstly, buckling tests based on results available in the literature were performed to establish a methodology for spacer grid finite element-based modeling. The, by considering a spacer grid interesting geometry and some possible variations associated to its fabrication, tolerance, the proposed numerical models were submitted to compression conditions to calculate the buckling force. Also, these models were validated for comparison with experimental buckling load results. Comparison of buckling predictions combined to observations of actual and simulated deformed spacer grids geometries permitted to verify the consistency and applicability of the proposed models. Thus, these numerical results show a good agreement between the and the experimental results. (author)

  2. A non-electrostatic spacer for aerosol delivery

    DEFF Research Database (Denmark)

    Bisgaard, H; Anhøj, J; Klug, B

    1995-01-01

    A pear shaped non-electrostatic spacer, composed of steel with a volume of 250 ml and equipped with a facemask containing integrated inlet and outlet valves for inspiration and expiration, was compared with three plastic spacers. The plastic spacers were primed with repeated puffs from a budesonide...... pressurised metered dose inhaler (p-MDI) to minimise the electrostatic charge on the plastic. The procedure prolonged the half life (t1/2) of the aerosol in the Nebuhaler from nine to 32 seconds. A normal cleaning procedure reduced the aerosol t1/2 back to baseline. The t1/2 of the aerosol in the metal spacer...... was 27 seconds and independent of the use of p-MDI. In vitro the maximum dose of budesonide from a p-MDI, expressed as a percentage of the nominal dose, was 56% from the non-electrostatic spacer, 61% from the Nebuhaler, 45% from the Babyhaler, and 30% from the AeroChamber. In 124 children, age 6 months...

  3. Zircaloy spacer grid for boiling light water reactors

    International Nuclear Information System (INIS)

    Borgiani, F.; Cali', G.P.; Cerretti, P.; Pazzo, P.

    1975-01-01

    The need to increase the neutronic efficiency of the new cores of BWR's, lead to study types of spacer-grids made of low neutronic absorption materials as zircaloy-4. The particular mechanical behaviour of this material suggested to design a spacer-grids such as to utilize only blanking, slotting and bending operations as plastic forming and to avoid therefore drawing effects. The optimization of the bending procedures lead to a final spacer-grids configuration equally stiff in all directions and planes. Only for the ''elastic constraints'' nichel alloy sheets were used to made easy the whole spacer design. The ''rigid constraints'', supporting the rods, have been obtained directly from the spacer structure. Calculations were performed to verify the mechanical strength of the main grid components. In this framework a computer code was developed to find the best elastic characteristic of the ''elastic constraints'' taking into account the machining tolerances. Some original methods to test the integral behaviour of the grid assembled as well as the procedures to be adopted for its best maintenance, are described

  4. Impact of spacer thickness on biofouling in forward osmosis

    KAUST Repository

    Valladares Linares, Rodrigo

    2014-06-01

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. © 2014 Elsevier Ltd.

  5. Analyses of the Collapse Behavior of a Spacer Grid

    International Nuclear Information System (INIS)

    Jang, Myung-Geun; Na, Geum Ju; Jag, Yeon-Hui; Kim, Hee Cheol; Kim, Jong-Bong; Kim, Jaeyoug

    2016-01-01

    In order to investigate the protection capability of a spacer grid assembly for impact load, a hammer impact test has been carried out. The crush strength is measured in the hammer impact test. Song et al. carried out the experiment and finite element analysis for the hammer impact test for various weld line depth. Park et al. designed the spacer grid shape to get required crush strength via finite element analysis. Song et al. also optimized the spacer grid shape to maximize the crush strength, and carried out the finite element analysis for the hammer impact test considering the weld properties. Kim et al. carried out finite element analysis for various guide tube hole shape and compared the crush shape and crush strength. In this study, the effect of shape defect on the crush behavior in the hammer impact test is investigated. The spacer grid cannot be exactly the square. Therefore a lateral displacement (imperfection) is imposed to square spacer grid and then hammer impact is carried out. The effect of the lateral imperfection on the crush strength is investigated. The effect of the shape defect on the crushing behavior in the hammer impact test is investigated by finite element analysis. It is shown that the collapse become severe as the lateral imperfection displacement increases, especially when the imperfection is greater than or equal to 0.7 mm

  6. CRISPR interference and priming varies with individual spacer sequences.

    Science.gov (United States)

    Xue, Chaoyou; Seetharam, Arun S; Musharova, Olga; Severinov, Konstantin; Brouns, Stan J J; Severin, Andrew J; Sashital, Dipali G

    2015-12-15

    CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems allow bacteria to adapt to infection by acquiring 'spacer' sequences from invader DNA into genomic CRISPR loci. Cas proteins use RNAs derived from these loci to target cognate sequences for destruction through CRISPR interference. Mutations in the protospacer adjacent motif (PAM) and seed regions block interference but promote rapid 'primed' adaptation. Here, we use multiple spacer sequences to reexamine the PAM and seed sequence requirements for interference and priming in the Escherichia coli Type I-E CRISPR-Cas system. Surprisingly, CRISPR interference is far more tolerant of mutations in the seed and the PAM than previously reported, and this mutational tolerance, as well as priming activity, is highly dependent on spacer sequence. We identify a large number of functional PAMs that can promote interference, priming or both activities, depending on the associated spacer sequence. Functional PAMs are preferentially acquired during unprimed 'naïve' adaptation, leading to a rapid priming response following infection. Our results provide numerous insights into the importance of both spacer and target sequences for interference and priming, and reveal that priming is a major pathway for adaptation during initial infection. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  7. Decision analysis model evaluating the cost of a temporary hydrogel rectal spacer before prostate radiation therapy to reduce the incidence of rectal complications.

    Science.gov (United States)

    Hutchinson, Ryan C; Sundaram, Varun; Folkert, Michael; Lotan, Yair

    2016-07-01

    We conducted a decision analysis to evaluate the cost effectiveness of a newly Food and Drug Administration approved rectal spacer gel (SpaceOAR, Augmenix) for the reduction of rectal toxicity of prostate radiation therapy (RT). A decision tree model (TreeAge Pro) was used to compare the strategy of pretherapy placement of a spacing hydrogel before RT to RT alone. The model compared costs associated with rectal complications because of rectal toxicity over a 10-year period across 3 different RT modalities. Rectal toxicity rates were estimated from studies on conformal RT dose escalation, high-dose stereotactic body radiotherapy (SBRT) and low-dose SBRT. Rectal toxicity reduction rates (baseline reduction 70%) were estimated from recently published 15 month data using a rectal spacer. Direct and indirect cost estimates for established grades of rectal toxicity were based on national and institutional costs. Reduction in short-term complications were assumed to carry forward to a reduction in long-term toxicity. One-way and two-way sensitivity analyses were performed. The overall standard management cost for conformal RT was $3,428 vs. $3,946 with rectal spacer for an incremental cost of $518 over 10 years. A 1-way sensitivity analyses showed the breakeven cost of spacer at $2,332 or a breakeven overall risk reduction of 86% at a cost of $2,850. For high-dose SBRT, spacer was immediately cost effective with a savings of $2,640 and breakeven risk reduction at 36%. However, 2-way spacer cost to risk reduction sensitivity analyses were performed. The use of a rectal spacer for conformal RT results in a marginal cost increase with a significant reduction in rectal toxicity assuming recently published 15 month rectal toxicity reduction is maintained over 10 years. For high-dose SBRT it was cost effective. Further studies would be necessary to validate the long-term benefits of rectal spacers. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Biomechanical Analysis of an Expandable Lumbar Interbody Spacer.

    Science.gov (United States)

    Soriano-Baron, Hector; Newcomb, Anna G U S; Malhotra, Devika; Palma, Atilio E; Martinez-Del-Campo, Eduardo; Crawford, Neil R; Theodore, Nicholas; Kelly, Brian P; Kaibara, Taro

    2018-03-13

    Recently developed expandable interbody spacers are widely accepted in spinal surgery; however, the resulting biomechanical effects of their use have not yet been fully studied. We analyzed the biomechanical effects of an expandable polyetheretherketone interbody spacer inserted through a bilateral posterior approach with and without different modalities of posterior augmentation. Biomechanical nondestructive flexibility testing was performed in 7 human cadaveric lumbar (L2-L5) specimens followed by axial compressive loading. Each specimen was tested under 6 conditions: 1) intact, 2) bilateral L3-L4 cortical screw/rod (CSR) alone, 3) WaveD alone, 4) WaveD + CSR, 5) WaveD + bilateral L3-L4 pedicle screw/rod (PSR), and 6) WaveD + CSR/PSR, where CSR/PSR was a hybrid construct comprising bilateral cortical-level L3 and pedicle-level L4 screws interconnected by rods. The range of motion (ROM) with the interbody spacer alone decreased significantly compared with the intact condition during flexion-extension (P = 0.02) but not during lateral bending or axial rotation (P ≥ 0.19). The addition of CSR or PSR to the interbody spacer alone condition significantly decreased the ROM compared with the interbody spacer alone (P ≤ 0.002); and WaveD + CSR, WaveD + PSR, and WaveD + CSR/PSR (hybrid) (P ≥ 0.29) did not differ. The axial compressive stiffness (resistance to change in foraminal height during compressive loading) with the interbody spacer alone did not differ from the intact condition (P = 0.96), whereas WaveD + posterior instrumentation significantly increased compressive stiffness compared with the intact condition and the interbody spacer alone (P ≤ 0.001). The WaveD alone significantly reduced ROM during flexion-extension while maintaining the axial compressive stiffness. CSR, PSR, and CSR/PSR hybrid constructs were all effective in augmenting the expandable interbody spacer system and improving its stability. Copyright © 2018 Elsevier Inc. All

  9. Bone-anchored hearing device placement with translabyrinthine tumor removal.

    Science.gov (United States)

    McRackan, Theodore R; Goddard, John C; Wilkinson, Eric P; Slattery, William H; Brackmann, Derald E

    2015-02-01

    Translabyrinthine resection of intracranial tumors results in single-sided deafness, which can be treated by surgical and nonsurgical means. Here we describe the first series examining complication and device usage rates among patients receiving a surgically implanted bone-anchored hearing device (BAHD) at the time of translabyrinthine tumor removal. Case series with chart review. Private tertiary neurotologic referral center. Patients (N = 154) undergoing concurrent BAHD placement and translabyrinthine tumor resection. Concurrent BAHD placement and translabyrinthine tumor removal. Postoperative complication rates and BAHD usage. Of the 154 patients, 121 (78.6%) had no device-related complications. The most common device-related complications were skin overgrowth (8.4%), acute infection (5.2%), and chronic infection (3.2%). The overall and specific complication rates did not differ from published BAHD complication rates. One patient (0.6%) developed a cerebrospinal leak through the surgical site for the device. At the time of last follow-up (mean, 39.8 months), 151 patients (95.0%) were still using their devices. Patients undergoing concurrent translabyrinthine tumor removal and BAHD placement exhibit similar device-related complication profiles as patients undergoing standard device placement. Based on these outcomes and the high long-term usage rates, BAHD insertion at the time of translabyrinthine intracranial surgery can be considered a safe and useful procedure. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  10. Technical and surgical aspects of the sphenopalatine ganglion (SPG) microstimulator insertion procedure

    DEFF Research Database (Denmark)

    Assaf, A T; Hillerup, S; Rostgaard, J

    2016-01-01

    procedure. Perioperative surgical sequelae included sensory disturbances, pain, and swelling. Follow-up procedures included placement of a second microstimulator on the opposite side (n=2), adjustment of the microstimulator lead location (n=13), re-placement after initial unsuccessful placement (n=1...

  11. Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

    Science.gov (United States)

    Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2016-08-01

    Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

  12. Shelf life of pie caps with biodegradable films as spacers

    Directory of Open Access Journals (Sweden)

    Daniela Verónica Escobar Gianni

    2013-01-01

    Full Text Available Commonly pie caps at market use polyethylene films as spacers between them. This paper studies the conventional spacers replacement with edible and biodegradable films made with whey protein isolate (WPI and potassium sorbate as a preservative. Besides facilitating the separation of pie caps, with this application is intended to increase their shelf life. The films made by the compression molding method were used as spacers in pie caps without preservative in their formula (A and with preservative (B and they were compared with conventional polyethylene spacers (C. During four months, monthly sensory, microbiological and physicochemical (humidity evaluations were done on the pie caps, together with humidity and solubility evaluations of the films. None of the samples showed microbiological or sensory deterioration. The sensory attributes showed no or slight difference in study time. Between samples the differences were minor: the best scores were for sample A in color, sample C in flavor, and samples B and C in texture and overall liking. The edible films have an interesting potential for this application, although studies in disguise the flavor of serum should be done.

  13. Deformation behavior of cell spring of an irradiated spacer grid

    International Nuclear Information System (INIS)

    Jin, Y. G.; Baek, S. J.; Ryu, W. S.; Kim, G. S.; Yoo, B. O.; Kim, D. S.; Ahn, S. B.; Chun, Y. B.; Choo, Y. S.

    2012-01-01

    Mechanical properties of a space grid of a fuel assembly are of great importance for fuel operation reliability in extended fuel burnup and duration of fuel life. The spacer grid with inner and outer straps has cell spring and dimples, which are in contact with the fuel rod. The spacer grids supporting the fuel rods absorb vibration impacts due to the reactor coolant flow and also grid spring force is decreasing under irradiation. This reduction of contact force might cause the grid to rod fretting wear. The fretting failure of the fuel rod is one of the significant issues recently in the nuclear industry from an economical as well as a safety concern. Thus, it is important to understand the characteristics of cell spring behavior for an irradiated spacer grid. In the present study, the stiffness test and dimensional measurement of cell springs were conducted to investigate the deformation behavior of cell springs of an irradiated spacer grid in a hot cell at IMEF (irradiated materials examination facility) of KAERI

  14. Novel spacers for mass transfer enhancement in membrane separations

    NARCIS (Netherlands)

    Li, F.; Meindersma, G.W.; de Haan, A.B.; Reith, T.

    2005-01-01

    The optimal flow pattern for mass transfer enhancement in spacer-filled channels is characterized by the coexistence of transversal and longitudinal vortices in the flow close to the channel walls and minimal cross-flow power consumption in the middle of the channel. The mass transfer enhancement of

  15. Multi-layer spacer geometries with improved mass transport

    NARCIS (Netherlands)

    Balster, J.H.; Punt, Ineke G.M.; Stamatialis, Dimitrios; Wessling, Matthias

    2006-01-01

    In electrodialysis desalination processes, it is desirable to operate at the highest practicable current density in order to get the maximum ion flux per unit membrane area. The operating current density is limited by concentration polarisation. In this work the development of optimal spacer

  16. CRISPR interference and priming varies with individual spacer sequences

    NARCIS (Netherlands)

    Xue, Chaoyou; Seetharam, Arun S.; Musharova, Olga; Severinov, Konstantin; Brouns, Stan J.J.; Severin, Andrew J.; Sashital, Dipali G.

    2015-01-01

    CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems allow bacteria to adapt to infection by acquiring 'spacer' sequences from invader DNA into genomic CRISPR loci. Cas proteins use RNAs derived from these loci to target cognate sequences for

  17. The internal transcribed spacer rDNA specific markers for ...

    African Journals Online (AJOL)

    ... schinifolium. These primers are useful to study the structure of Rutaceae family. Such identifications will be helpful for phylogenetic analysis in intraspecies population of the genus Zanthoxylum. Key words: Zanthoxylum piperitum, rDNA Int-sp markers, phylogenetic relationship, ribosomal DNA, internal transcribed spacer.

  18. The 'rare allele phenomenon' in a ribosomal spacer

    NARCIS (Netherlands)

    Schilthuizen, M.; Hoekstra, R.F.; Gittenberger, E.

    2001-01-01

    We describe the increased frequency of a particular length variant of the internal transcribed spacer 1 (ITS-1) of the ribosomal DNA in a hybrid zone of the land snail Albinaria hippolyti. The phenomenon that normally rare alleles or other markers can increase in frequency in the centre of hybrid

  19. Comparative phylogenetic analysis of intergenic spacers and small ...

    African Journals Online (AJOL)

    Two microsporidian isolates extracted from infected tasar silkworms (Antheraea mylitta) collected from forest area in Deoghar district, Jharkhand, India were subjected to PCR amplification using intergenic spacer (IGS) region and small subunit rRNA (SSU-rRNA) gene specific primers followed by cloning and sequencing.

  20. On the impact analysis of a PWR spacer grid

    International Nuclear Information System (INIS)

    Song, Kee Nam; Lee, S. H.

    2012-01-01

    A spacer grid, which is an interconnected array of slotted grid straps and is welded at the intersections to form an egg crate structure, is one of the most important structural components in a PWR fuel assembly. From a structural point of view, the spacer grid is required to have sufficient crush strength under lateral loads so that nuclear fuel rods are maintained in a cool able geometry, and that control rods can be inserted. The capacity of a spacer grid to resist lateral loads is usually characterized in terms of its crush strength, and it was reported that the lateral crush strength of the spacer grid is closely related with welding quality of the spacer grid. Microstructures in the weld zone, including a heat affected zone (HAZ), are different from that in a parent material. Consequently, the mechanical properties in the weld zone are different from those in the parent material to some extent. When a welded structure is loaded, the mechanical behavior of the welded structure might be different from the case of a structure with homogeneous mechanical properties. Nonetheless, mechanical properties in the welded structure have been neglected in many structural analyses of the spacer grid due to a lack of mechanical properties in the weld zone. When the weld zone is very narrow and the interfaces are not clear, it is difficult to take tensile test specimens in the weld zone. The reason for this is that the mechanical properties in the parent material are usually used in the structural analyses in the welded structure. As an aside, it has been recently determined that the ball indentation technique has the potential to be an excellent substitute for a standard tensile test, particularly in the case of small specimens or property gradient materials such as welds. In this study, to investigate the effect on the mechanical behavior of the spacer grid when using weld mechanical properties, strength analyses considering the weld mechanical properties recently obtained

  1. 3-D flow analyses for design of nuclear fuel spacer

    Energy Technology Data Exchange (ETDEWEB)

    Karouta, Z. [ABB Combustion Engineering, Windsor, CT (United States); GU, Chun-Yuan [ABB Corporate Research, Vaesteras (Sweden); Schoelin, B. [ABB Atom AB, Vaesteras (Sweden)

    1995-09-01

    The Computational Fluid Dynamics (CFD) code, CFDS-FLOW3D, was used to develop improved fuel designs for PWR cores. It was used primarily to understand the fluid dynamics of grid spacers, the mass transfer between subchannels caused by spacers and in the long term to develop two-phase models which enable prediction of critical heat flux in PWR fuel. A single subchannel of one grid span was modeled. In this model different spacer designs with mixing devices were analyzed. A special treatment of the boundary condition was developed making use of flow symmetry to model the mass transfer between different subchannels and minimize the size of the computational model. This reduced the computational model to a fraction of a subchannel using traditional periodic boundary conditions. The Navier-Stokes equation was solved for the liquid and the flow turbulence was modeled by k-{xi} turbulence model. The spacer and mixing device were treated as infinite thin surfaces in the model and a zero velocity condition and turbulent wall function were applied on each side of the thin surfaces. This approach simulated the swirl from the mixing devices well, but had the drawback of not predicting pressure drop accurately since the wake behind the plates and the acceleration effect of the spacers were ignored. CFDS-FLOW3D models with mixing devices were applied in the single-phase flow regime. Velocity profiles from the CFDS-FLOW3D models were compared to Laser Doppler Velocimeter measurements taken from the flow field downstream of spaces in a full scale, cold water test loop. The predicted axial and lateral velocity profiles were in good agreement with the measurements. The evaluation of the performance of different spacer devices was made by comparing the swirl ratio downstream of the grid spacers. It is planned to evaluate heat transfer coefficient downstream of the spaces, to implement two-phase flow models, and to model the superheated boundary layer on the surface of the fuel rod.

  2. Implementation of spacer therapy for acute asthma in children.

    LENUS (Irish Health Repository)

    Vandeleur, M

    2009-09-01

    The aim was to develop and implement an evidence based guideline for the treatment of acute asthma using a metered dose inhaler and spacer combination. Children admitted to Cork University Hospital Paediatric Department with acute asthma were identified during two identical 2 month seasonal periods before (2005) and after (2006) implementation of the new guidelines in September 2006. Pre-intervention and post-intervention audits by case note review were performed to determine the impact of and compliance with this evidence-based guideline emphasising patient assessment, spacer delivered bronchodilator and specific discharge criteria. Patients had similar characteristics during the two study periods. There was a raised threshold for admission after guideline implementation with 11\\/52 patients having mild exacerbations in 2006, compared to 21\\/36 in 2005. Duration of admission was less in the post-implementation group for equivalent exacerbation severity e.g. for moderate severity; 28 hours in 2005, 23 hours in 2006. Duration of bronchodilator therapy was shorter in 2006 and more likely to be given by spacer device earlier for equivalent levels of severity e.g. for moderate exacerbations, in 2006 the average length of salbutamol therapy was 18 hours with 12 hours by spacer device, in 2005 the average length of therapy was 25 hours with 3 hours by spacer. There was earlier initiation of oral corticosteroids; the average time to administration was 56 minutes in 2006 and 227 minutes in 2005. There was an improved documentation of asthma education in 2006 e.g. inhaler technique was reviewed in 37\\/52 in 2006, 21\\/35 in 2005 and better use of written action plans.

  3. New innovative method relating guided surgery to dental implant placement.

    Science.gov (United States)

    Fauroux, M-A; De Boutray, M; Malthiéry, E; Torres, J-H

    2018-02-20

    Companies selling dental implant guided systems mostly offer similar surgical guides. The purpose of this paper is to present an innovative-guided surgery system which originality lies in its guidance device, and to report the author's experience in using this system for dental implant surgery. Two parallel tubes on either side of the drilling axis guide the successive drills and the implant placement. As a result of the lateral guidance, there is no friction of the drills on the surgical guide, which would damage it or contaminate the drilling hole with particles torn out from the guide. No radiological guide is needed during the radiographic examination stage. No successive diameter reduction tubes are requested. This guide can be used for all brands of implants. In our experience, 67 implants (31 titanium and 36 zircon implants) were placed in 35 patients with guided surgery system. Multiple clinical cases were treated with this system: 'one-stage' or a 'two-stage' surgical protocol, with flap and flapless surgical techniques, and with delayed or immediate loading. Clinical cases treated revealed good implant placement with planning. The widely open design of this guide allows irrigation and practitioner's sight control under conditions comparable to those of operations performed without surgical guide. This dental implant guided system appears to be a significant advance in the field of implant surgical guides. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  4. Optimal placement of capacito

    Directory of Open Access Journals (Sweden)

    N. Gnanasekaran

    2016-06-01

    Full Text Available Optimal size and location of shunt capacitors in the distribution system plays a significant role in minimizing the energy loss and the cost of reactive power compensation. This paper presents a new efficient technique to find optimal size and location of shunt capacitors with the objective of minimizing cost due to energy loss and reactive power compensation of distribution system. A new Shark Smell Optimization (SSO algorithm is proposed to solve the optimal capacitor placement problem satisfying the operating constraints. The SSO algorithm is a recently developed metaheuristic optimization algorithm conceptualized using the shark’s hunting ability. It uses a momentum incorporated gradient search and a rotational movement based local search for optimization. To demonstrate the applicability of proposed method, it is tested on IEEE 34-bus and 118-bus radial distribution systems. The simulation results obtained are compared with previous methods reported in the literature and found to be encouraging.

  5. Optimization of non-woven spacers by CFD and validation by experiments

    NARCIS (Netherlands)

    Li, F.; Meindersma, G.W.; de Haan, A.B.; Reith, T.

    2002-01-01

    CFD simulations were used to determine mass transfer coefficients and power consumptions in channels filled with non-woven net spacers. The geometric parameters of a non-woven spacer were found to have a great influence on the performance of a spacer in terms of mass transfer enhancement and power

  6. Biofouling Control in Spiral-Wound Membrane Systems: Impact of Feed Spacer Modification and Biocides

    KAUST Repository

    Siddiqui, Amber

    2016-12-01

    High-quality drinking water can be produced with membrane-based filtration processes like reverse osmosis and nanofiltration. One of the major problems in these membrane systems is biofouling that reduces the membrane performance, increasing operational costs. Current biofouling control strategies such as pre-treatment, membrane modification, and chemical cleaning are not sufficient in all cases. Feed spacers are thin (0.8 mm), complex geometry meshes that separate membranes in a module. The main objective of this research was to evaluate whether feed spacer modification is a suitable strategy to control biofouling. Membrane fouling simulator studies with six feed spacers showed differences in biofouled spacer performance, concluding that (i) spacer geometry influences biofouling impact and (ii) biofouling studies are essential for evaluation of spacer biofouling impact. Computed tomography (CT) was found as a suitable technique to obtain three-dimensional (3D) measurements of spacers, enabling more representative mathematical modeling of hydraulic behavior of spacers in membrane systems. A strategy for developing, characterizing, and testing of spacers by numerical modeling, 3D printing of spacers and experimental membrane fouling simulator studies was developed. The combination of modeling and experimental testing of 3D printed spacers is a promising strategy to develop advanced spacers aiming to reduce the impact of biofilm formation on membrane performance and to improve the cleanability of spiral-wound membrane systems.

  7. Excessive bleeding in the floor of the mouth after endosseus implant placement: a report of two cases

    NARCIS (Netherlands)

    Dubois, L.; de Lange, J.; Baas, E.; van Ingen, J.

    2010-01-01

    Placement of dental implants in the interforaminal region of the edentulous mandible is considered a safe and routine surgical procedure. Hemorrhage in the floor of the mouth has been reported as a rare, potentially life-threatening complication related to the placement of implants in this region.

  8. The internal transcribed spacer of nuclear ribosomal DNA in the gymnosperm Gnetum.

    Science.gov (United States)

    Won, Hyosig; Renner, Susanne S

    2005-09-01

    We analyze the structure of the internal transcribed spacers ITS1 and ITS2 of the nuclear ribosomal DNA in the gymnosperm Gnetum, using a phylogenetic framework derived mainly from an intron in the nuclear low-copy LEAFY gene. Gnetum comprises 25-35 species in South America, Africa, and Asia, of which we sampled 16, each with two to six clones. Criteria used to assess ITS functionality were highly divergent nucleotide substitution, GC content, secondary structure, and incongruent phylogenetic placement of presumed paralogs. The length of ITS1 ranged from 225 to 986 bp and that of ITS2 from 259 to 305 bp, the largest ranges so far reported from seed plants. Gnetum ITS1 contains two informative sequence motifs, but different from other gymnosperms, there are only few and short (7-13 bp) tandem repeats. Gnetum ITS2 contains two structural motifs, modified in different clades by shortening of stems and loops. Conspecific sequences grouped together except for two recombinant pseudogenes that had ITS1 of one clade and ITS2 of another. Most of the pseudogenic ITS copies, paralogs, and putative chimeras occurred in a clade that according to a fossil-calibrated chloroplast-DNA clock has an age of a few million years. Based on morphology and chromosome numbers, the most plausible causes of the observed high levels of ITS polymorphism are hybridization, allopolyploidy, and introgression.

  9. Effect of plastic spacer handling on salbutamol lung deposition in asthmatic children

    DEFF Research Database (Denmark)

    Lipworth, Brian J; Lee, Daniel K C; Anhøj, Jacob

    2002-01-01

    AIMS: To study the effects of electrostatics in a plastic spacer on the lung deposition of salbutamol in asthmatic children. METHODS: Twenty-five children (5-12 years) with mild asthma were given salbutamol hydrofluoroalkane pressurized metered dose inhaler 400 micro g via a 750 ml plastic spacer.......14 fold (1.24, 3.69), or vs RinsedDelay 3.28 fold (2.13, 5.04). CONCLUSIONS: The relative lung dose of salbutamol from a plastic spacer may differ considerably depending on spacer handling suggesting that nonelectrostatic spacers may be the best way forward....

  10. Heat transfer in smooth and roughened rod bundles near spacer grids

    International Nuclear Information System (INIS)

    Marek, J.; Rehme, K.

    1975-03-01

    An experimental investigation was performed of the heat transfer in smooth and rough rod bundles near spacer grids. Detailed wall temperature distributions were measured which clearly demonstrated that even in rod bundles roughened by artificial roughnesses there are no hot spots near spacer grids. On the basis of the few experimental results from the literature and the new data, heat transfer correlations are proposed for smooth and rough surfaces near spacer grids. These correlations allow a prediction to be made in a good approximation of the heat transfer near spacer grids as a function of the flow contraction due to the spacer. (orig.) [de

  11. Response of an electrostatic probe for a right cylindrical spacer

    DEFF Research Database (Denmark)

    Rerup, T; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    During the last decade many experimental studies of surface charge phenomena have been undertaken employing right cylindrical spacers. Measurement of the surface charge was performed using small electrostatic field probes to scan across the dielectric surface. Charges are electrostatically induced...... on the sensor plate by the ambient surface charge, and hence as the probe is moved parallel to the surface the potential of the sensor plate changes. The probe sensor-plate potential is thus the parameter of interest as this parameter can be related in a quantitative manner to the surface charge density....... In the present study, the influence of the spacer geometry upon the λ-function is examined. This knowledge allows the response of the probe with reference to detection sensitivity and spatial selectivity to be considered. Such probe characteristics enable general conclusions to be reached about...

  12. Patient Positioning and Port Placement for Robot-Assisted Surgery

    Science.gov (United States)

    Chang, Charles; Steinberg, Zoe; Shah, Anup

    2014-01-01

    Abstract The introduction of robotic surgical systems and their integration into minimally invasive procedures have changed the landscape of laparoscopic surgery dramatically. Intuitive Surgical's da Vinci Surgical System was first approved by the Food and Drug Administration for cardiothoracic procedures in the late 1990s. This trend quickly spread through other surgical specialties, with urologists as one of the frontrunners in adoption. Subsequently, pediatric urologists have adopted robot-assisted procedures in selected centers, performing procedures such as pyeloplasty for ureteropelvic junction obstruction, partial and complete nephrectomy, and both intravesical and extravesical ureteral reimplantation. In this article, we will discuss technical considerations related to patient positioning and port placement in pediatric robot-assisted surgery. PMID:24548088

  13. An insulating grid spacer for large-area MICROMEGAS chambers

    International Nuclear Information System (INIS)

    Bernard, D.; Delagrange, H.; D'Enterria, D.G.; Guay, M.L.M. Le; Martinez, G.; Mora, M.J.; Pichot, P.; Roy, D.; Schutz, Y.; Gandi, A.; Oliveira, R. de

    2002-01-01

    We present a novel design for large-area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides a uniform 200 μm amplification gap. The uniformity of the amplification gap thickness has been verified. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages

  14. Bimetallic spacer means for a nuclear fuel assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.

    1981-01-01

    A bimetallic spacer means designed to be cooperatively associated with a nuclear fuel assembly and operative to resist the occurrence of in-reactor bowing of the nuclear fuel assembly. The subject bimetallic spacer means in accord with one embodiment of the invention includes a member formed, at least principally, of Zircaloy to which are attached a plurality of stainless steel strips. The latter stainless steel strips are located on the external surface of the Zircaloy member and with the major axis of each of the plurality of stainless steel strips extending substantially perpendicular to the major axis of the Zircaloy member. In accord with another embodiment of the invention, the subject bimetallic spacer means includes a member formed at least principally of Zircaloy to which a plurality of stainless steel strips are attached so as to be positioned thereon externally thereof and with the major axis of each of the plurality of stainless steel strips extending substantially parallel to the major axis of the Zircaloy member. In accord with a further embodiment of the invention, the stainless steel strips are attached to preselected members, each embodying at least a cladding of Zircaloy, which are located in the rows of fuel rods that define the perimeter of the fuel matrix of the nuclear fuel assembly. In each of the embodiments, the stainless steel strips during power production expand outwardly to a greater extent than do the members to which the stainless steel strips are attached, thereby forming stiff springs which abut against like bimetallic spacer means with which the other nuclear fuel assemblies are provided in a given nuclear reactor core to thus prevent the occurrence of in-reactor bowing of the nuclear fuel assemblies. Namely, the stainless steel strips expand laterally relative to the fuel assembly and thereby occupy the space adjacent to the external surface of the fuel assembly

  15. Effects of two different post-surgical protocols including either 0.05 % chlorhexidine herbal extract or 0.1 % chlorhexidine on post-surgical plaque control, early wound healing and patient acceptance following standard periodontal surgery and implant placement.

    Science.gov (United States)

    Laugisch, Oliver; Ramseier, Christoph A; Salvi, Giovanni E; Hägi, Tobias T; Bürgin, Walter; Eick, Sigrun; Sculean, Anton

    2016-11-01

    The aim of this study was to compare early wound healing, tooth staining and patient acceptance with two different post-surgical maintenance protocols. Forty patients scheduled for flap surgery to treat periodontal pockets or accommodate dental implants were randomly assigned to receive the following two different post-surgical maintenance protocols: (a) 2 weeks rinsing with a 0.05 % chlorhexidine digluconate (CHX)/herbal extract combination (test) or (b) a 0.1 % CHX solution (control). Early wound healing was evaluated clinically and immunologically. Tooth staining and patient acceptance were assessed by means of visual analogue scale (VAS). Both groups presented with comparable wound healing profiles. No statistically significant differences were observed between the two protocols regarding early wound healing and plaque index (p > 0.05). However, in the control group, statistically significantly more patients felt discomfort due to tooth staining (p = 0.0467). Compared with patients from the test group, patients in the control group reported statistically significant more irritation of taste at week 1 (p = 0.0359) and at week 2 (p = 0.0042). The present findings indicate that the two CHX protocols resulted in comparable healing and inhibition of plaque formation. Tooth staining and subjective discomfort related to irritation of taste were more frequent in the control group. A post-operative protocol including 0.05 % CHX/herbal extract may have the potential to improve patient compliance during post-operative maintenance.

  16. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

  17. Membrane-spacer assembly for flow-electrode capacitive deionization

    Science.gov (United States)

    Lee, Ki Sook; Cho, Younghyun; Choo, Ko Yeon; Yang, SeungCheol; Han, Moon Hee; Kim, Dong Kook

    2018-03-01

    Flow-electrode capacitive deionization (FCDI) is a desalination process designed to overcome the limited desalination capacity of conventional CDI systems due to their fixed electrodes. Such a FCDI cell system is comprised of a current collector, freestanding ion-exchange membrane (IEM), gasket, and spacer for flowing saline water. To simplify the cell system, in this study we combined the membrane and spacer into a single unit, by coating the IEM on a porous ceramic structure that acts as the spacer. The combination of membrane with the porous structure avoids the use of costly freestanding IEM. Furthermore, the FCDI system can be readily scaled up by simply inserting the IEM-coated porous structures in between the channels for flow electrodes. However, coating the IEM on such porous ceramic structures can cause a sudden drop in the treatment capacity, if the coated IEM penetrates the ceramic pores and prevents these pores from acting as saline flow channels. To address this issue, we blocked the larger microscale pores on the outer surface with SiO2 and polymeric multilayers. Thus, the IEM is coated only onto the top surface of the porous structure, while the internal pores remain empty to function as water channels.

  18. Increased antibiotic release and equivalent biomechanics of a spacer cement without hard radio contrast agents.

    Science.gov (United States)

    Bitsch, R G; Kretzer, J P; Vogt, S; Büchner, H; Thomsen, M N; Lehner, B

    2015-10-01

    We compared a novel calcium carbonate spacer cement (Copal® spacem) to well-established bone cements. Electron microscopic structure and elution properties of the antibiotics ofloxacin, vancomycin, clindamycin, and gentamicin were examined. A knee wear simulator model for articulating cement spacers was established. Mechanical tests for bending strength, flexural modulus, and compressive and fatigue strength were performed. The electron microscopic analysis showed a microporous structure of the spacer cement, and this promoted a significantly higher and longer antibiotic elution. All spacer cement specimens released the antibiotics for a period of up to 50days with the exception of the vancomycin loading. The spacer cement showed significantly less wear scars and fulfilled the ISO 5833 requirements. The newly developed spacer cement is a hydrophilic antibiotic carrier with an increased release. Cement without hard radio contrast agents can improve tribological behaviour of spacers, and this may reduce reactive wear particles and abrasive bone defects. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Independent tuning of double plasmonic waves in a free-standing graphene-spacer-grating-spacer-graphene hybrid slab.

    Science.gov (United States)

    Chen, Ying; Yao, Jin; Song, Zhengyong; Ye, Longfang; Cai, Guoxiong; Liu, Qing Huo

    2016-07-25

    The independent excitation and tuning of double plasmonic waves are realized in a free-standing graphene-spacer-grating-spacer-graphene (GSGSG) hybrid slab, which consists of two graphene field effect transistors placed back-to-back to each other. Resulted from the high transparency and the tight confinement of surface plasmonic mode for the graphene, double plasmonic waves can be independently excited by guided-mode resonances (GMRs). Theoretical and numerical investigations are performed in the mid-infrared band. Furthermore, the tuning of individual GMR resonant wavelengths with respect to the system parameters is studied. The results provide opportunities to engineer the proposed hybrid slab for wavelength selective and multiplexing applications.

  20. Development and characterization of 3D-printed feed spacers for spiral wound membrane systems

    KAUST Repository

    Siddiqui, Amber

    2016-01-02

    Feed spacers are important for the impact of biofouling on the performance of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane systems. The objective of this study was to propose a strategy for developing, characterizing, and testing of feed spacers by numerical modeling, three-dimensional (3D) printing of feed spacers and experimental membrane fouling simulator (MFS) studies. The results of numerical modeling on the hydraulic behavior of various feed spacer geometries suggested that the impact of spacers on hydraulics and biofouling can be improved. A good agreement was found for the modeled and measured relationship between linear flow velocity and pressure drop for feed spacers with the same geometry, indicating that modeling can serve as first step in spacer characterization. An experimental comparison study of a feed spacer currently applied in practice and a 3D printed feed spacer with the same geometry showed (i) similar hydraulic behavior, (ii) similar pressure drop development with time and (iii) similar biomass accumulation during MFS biofouling studies, indicating that 3D printing technology is an alternative strategy for development of thin feed spacers with a complex geometry. Based on the numerical modeling results, a modified feed spacer with low pressure drop was selected for 3D printing. The comparison study of the feed spacer from practice and the modified geometry 3D printed feed spacer established that the 3D printed spacer had (i) a lower pressure drop during hydraulic testing, (ii) a lower pressure drop increase in time with the same accumulated biomass amount, indicating that modifying feed spacer geometries can reduce the impact of accumulated biomass on membrane performance. The combination of numerical modeling of feed spacers and experimental testing of 3D printed feed spacers is a promising strategy (rapid, low cost and representative) to develop advanced feed spacers aiming to reduce the impact of biofilm formation on

  1. Immediate placement of implant in fresh extraction socket with early loading

    Directory of Open Access Journals (Sweden)

    Archana Singh

    2012-01-01

    Full Text Available Implant placement in maxillary anterior region has most aesthetic challenges in implant dentistry because tooth loss lead to bone resorption and collapse of gingival architecture, which lead to aesthetic compromise and inadequate bone for implant placement. Immediate implant placement into fresh extraction socket reduces the treatment time, cost, preserved the gingival aesthetic and increases the comfort of the patient. This article describes the procedure for immediate implant placement in fresh extraction socket and early loading of implant with zirconia crown. Clinical and radiographic examination revealed width and length of the tooth for selecting implant size and design. Cement retained zirconia crown was used for early loading. Implant was successfully loaded and was functional during 36 months follow up period. Immediate placement and early loading of dental implant provides advantages like fewer surgical procedures, shorter treatment time, and improved aesthetic and psychological confidence.

  2. Surgical Audit

    African Journals Online (AJOL)

    2010-01-06

    Jan 6, 2010 ... A good way to describe the first surgical audits is that they were 'polite, restrained discussions'. This was the situation before the development of quality assurance in the business world. As this slowly infiltrated into the medical profession the discussions changed to more cri- teria based surgical audits.

  3. An insulating grid spacer for large-area MICROMEGAS chambers

    CERN Document Server

    Bernard, D; D'Enterria, D G; Le Guay, M; Martínez, G; Mora, M J; Pichot, P; Roy, D; Schutz, Y; Gandi, A; De Oliveira, R

    2002-01-01

    We present an original design for large area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides an uniform 200 $\\mu$m amplification gap. The uniformity of the amplification gap thickness has been verified under several experimental conditions. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages.

  4. Spacer grid with mixing blades for nuclear fuel assembly

    International Nuclear Information System (INIS)

    Noailly, J.

    1986-01-01

    The spacer grid for nuclear fuel assembly has two sets of intersecting metal plates provided with blades and defining cells. The plates are fitted only with half-blades associated with a single grid opening. The half-blades of adjacent cells are arranged at 90deg C to each other and each plate has at most one half-blade at each corner of a cell. The invention concerns fuel assemblies of pressurized water reactors. The blades arranged on a single side of the plate provide a good hydraulic uniformity. The invention provides a uniform distribution of blades (and thus of absorbing material in each hydraulic cell) [fr

  5. In vitro microbiologic evaluation of PTFE and cotton as spacer materials.

    Science.gov (United States)

    Paranjpe, Avina; Jain, Sumita; Alibhai, Karim J; Wadhwani, Chandur P; Darveau, Richard P; Johnson, James D

    2012-09-01

    To microbiologically evaluate the efficacy of cotton and polytetrafluoroethylene (PTFE) tape used as spacer materials. Twenty-six extracted human molars were restored using either cotton or PTFE tape as spacers under a standardized provisional restorative material (Cavit). The teeth were incubated for 7 days in a culture of Streptococcus gordonii or in liquid media alone. The spacers were removed and tested for bacterial contamination. The access cavities were also evaluated for bacterial contamination. Nine of 10 teeth with cotton spacers and one of 10 teeth with PTFE spacers were positive for S gordonii growth. The nine teeth in the cotton group also showed contamination of the access cavities. Even under optimal conditions, cotton spacers may cause leakage into the access cavities. Cotton fibers may serve as a route for bacterial contamination of the access cavities and root canal space. In contrast, PTFE tape did not provide an avenue for bacterial contamination.

  6. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    DEFF Research Database (Denmark)

    Liu, Tao; Li, Yingjun; Wang, Xiaodi

    2015-01-01

    Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I......, it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci...... in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence...

  7. Urethral catheterization facilitates preradiation fiducial marker placement in postprostatectomy patients.

    Science.gov (United States)

    Williams, Christopher; Costa, Joseph; Mandia, Stephen; Henderson, Randal; Marino, Robert; Mendenhall, Nancy

    2012-05-01

    Surgical absence of the prostate can make placement of fiducial markers difficult, because anatomic landmarks are distorted and there is a paucity of substantial tissue to hold fast the markers. We describe a method for improving the accuracy of fiducial marker placement for the purpose of salvage or adjuvant external beam radiation therapy for prostate cancer in patients who have undergone radical prostatectomy. To assist with identification of the urethrovesical junction and to facilitate placement of the markers, a Foley catheter was placed and the balloon was inflated. Gentle traction on the catheter seated the balloon at the bladder neck to echographically define the anatomy of the urethrovesical junction. Next, a rectal ultrasound probe was inserted into the rectum, allowing visualization of the region of the urethrovesical junction. Fiducial markers were then placed bilaterally in the detrusor muscle at the bladder neck or in the periurethral tissue using the applicator needle. The treating radiation oncologist verified that marker placement was suitable for assisting with radiation therapy in all cases. Preradiation pelvic imaging verified that markers were not in the bladder or urethral lumen, and there were no patient complaints of voiding out the markers with urination.

  8. Electrostatic charge on a plastic spacer device influences the delivery of salbutamol.

    Science.gov (United States)

    Wildhaber, J H; Devadason, S G; Hayden, M J; James, R; Dufty, A P; Fox, R A; Summers, Q A; LeSouëf, P N

    1996-09-01

    The aim of this study was to determine whether electrostatic charge on a plastic spacer decreases the delivery of salbutamol from a pressurized metered-dose inhaler (pMDI) and, if so, to find an optimal and practical treatment to remove the charge. Ten single actuations from a salbutamol pMDI were drawn through different Volumatic spacers at a constant flow of 60 L.min-1. The efficacies of different methods of removing charge were tested, including detergent coating of the spacers. A multistage liquid impinger was used to determine the particle size distribution of the output of the pMDI through the Volumatic spacers. The electrostatic charge on the inner surface of the spacers was measured both quantitatively with an electrometer, and qualitatively by the attraction of a thin strip of cellulose membrane to the wall of the spacer. Each experiment was repeated four times. Ionic detergent coating of the spacers removed the charge for at least 24 h. This resulted in an increase of 55-70% in small particle (< 6.8 microns) delivery compared to delivery from new spacers with high charge. We have demonstrated that electrostatic charge plays a major role in the delivery of salbutamol through plastic spacers. Adequate treatment with ionic detergent removes the charge and improves drug delivery.

  9. Nanoparticle-Based Brachytherapy Spacers for Delivery of Localized Combined Chemoradiation Therapy

    International Nuclear Information System (INIS)

    Kumar, Rajiv; Belz, Jodi; Markovic, Stacey; Jadhav, Tej; Fowle, William; Niedre, Mark; Cormack, Robert; Makrigiorgos, Mike G.; Sridhar, Srinivas

    2015-01-01

    Purpose: In radiation therapy (RT), brachytherapy-inert source spacers are commonly used in clinical practice to achieve high spatial accuracy. These implanted devices are critical technical components of precise radiation delivery but provide no direct therapeutic benefits. Methods and Materials: Here we have fabricated implantable nanoplatforms or chemoradiation therapy (INCeRT) spacers loaded with silica nanoparticles (SNPs) conjugated containing a drug, to act as a slow-release drug depot for simultaneous localized chemoradiation therapy. The spacers are made of poly(lactic-co-glycolic) acid (PLGA) as matrix and are physically identical in size to the commercially available brachytherapy spacers (5 mm × 0.8 mm). The silica nanoparticles, 250 nm in diameter, were conjugated with near infrared fluorophore Cy7.5 as a model drug, and the INCeRT spacers were characterized in terms of size, morphology, and composition using different instrumentation techniques. The spacers were further doped with an anticancer drug, docetaxel. We evaluated the in vivo stability, biocompatibility, and biodegradation of these spacers in live mouse tissues. Results: The electron microscopy studies showed that nanoparticles were distributed throughout the spacers. These INCeRT spacers remained stable and can be tracked by the use of optical fluorescence. In vivo optical imaging studies showed a slow diffusion of nanoparticles from the spacer to the adjacent tissue in contrast to the control Cy7.5-PLGA spacer, which showed rapid disintegration in a few days with a burst release of Cy7.5. The docetaxel spacers showed suppression of tumor growth in contrast to control mice over 16 days. Conclusions: The imaging with the Cy7.5 spacer and therapeutic efficacy with docetaxel spacers supports the hypothesis that INCeRT spacers can be used for delivering the drugs in a slow, sustained manner in conjunction with brachytherapy, in contrast to the rapid clearance of the drugs when

  10. Single-electron transistors fabricated with sidewall spacer patterning

    Science.gov (United States)

    Park, Byung-Gook; Kim, Dae Hwan; Kim, Kyung Rok; Song, Ki-Whan; Lee, Jong Duk

    2003-09-01

    We have implemented a sidewall spacer patterning method for novel dual-gate single-electron transistor (DGSET) and metal-oxide-semiconductor-based SET (MOSET) based on the uniform SOI wire, using conventional lithography and processing technology. A 30 nm wide silicon quantum wire is defined by a sidewall spacer patterning method, and depletion gates for two tunnel junctions of the DGSET are formed by the doped polycrystalline silicon sidewall. The fabricated DGSET and MOSET show clear single-electron tunneling phenomena at liquid nitrogen temperature and insensitivity of the Coulomb oscillation period to gate bias conditions. On the basis of the phase control capability of the sidewall depletion gates, we have proposed a complementary self-biasing method, which enables the SET/CMOS hybrid multi-valued logic (MVL) to operate perfectly well at high temperature, where the peak-to-valley current ratio of Coulomb oscillation severely decreases. The suggested scheme is evaluated by SPICE simulation with an analytical DGSET model, and it is confirmed that even DGSETs with a large Si island can be utilized efficiently in the multi-valued logic.

  11. Functional analysis of transcribed spacers of yeast ribosomal DNA.

    Science.gov (United States)

    Musters, W; Boon, K; van der Sande, C A; van Heerikhuizen, H; Planta, R J

    1990-12-01

    Making use of an rDNA unit, containing oligonucleotide tags in both the 17S and 26S rRNA gene, we have analyzed the effect of various deletions in the External Transcribed Spacer (ETS) and in one of the Internal Transcribed Spacers 1 (ITS1) on the process of ribosome formation in yeast. By following the fate of the tagged transcripts of this rDNA unit in vivo by Northern hybridization we found that deleting various parts of the ETS prevents the accumulation of tagged 17S rRNA and its assembly into 40S subunits, but not the formation of 60S subunits. Deleting the central region of ITS1, including a processing site that is used in an early stage of the maturation process, was also found to prevent the accumulation of functional 49 S subunits, whereas no effect on the formation of 60S subunits was detected. The implications of these findings for yeast pre-rRNA processing are discussed.

  12. Surgical treatment of degenerative spondylolisthesis.

    Science.gov (United States)

    Guigui, P; Ferrero, E

    2017-02-01

    Degenerative spondylolisthesis is a common pathology, often causing lumbar canal stenosis. There is, however, no strong consensus regarding the various medical and surgical treatments available. Surgery is indicated mainly for perceived functional impairment; when the indication is accepted, several questions determine the choice of surgical strategy. Improvement in neurological symptoms is one of the main treatment objectives. For this, it is useful to perform radicular decompression. Some authors recommend indirect decompression by interbody fusion (ALIF, TLIF, XLIF), others by means of an interspinous spacer but the most frequent technique is direct posterior decompression. In degenerative spondylolisthesis, functional results seem to be improved by associating stabilization to decompression, to prevent secondary destabilization. The following risk factors for destabilization are recognized: anteroposterior hypermobility, angular hypermobility and large disc height. Two stabilization techniques have been described: "dynamic" stabilization and (more frequently) fusion. Spinal instrumentation is frequently associated to fusion, in which case, it is essential for fusion position and length to take account of pelvic incidence and the patient's overall pattern of balance. Posterolateral fusion may be completed by interbody fusion (PLIF or TLIF). This has the theoretic advantage of increasing graft area and stability, restoring local lordosis and opening the foramina. Surgical treatment of degenerative spondylolisthesis usually consists in posterior release associated to instrumented fusion, but some cases can be more complex. It is essential for treatment planning to take account of the patient's general health status as well as symptomatology and global and segmental alignment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Penile Corporeal Reconstruction during Difficult Placement of a Penile Prosthesis

    Directory of Open Access Journals (Sweden)

    Viet Q. Tran

    2008-01-01

    Full Text Available For some patients with impotence and concomitant severe tunical/corporeal tissue fibrosis, insertion of a penile prosthesis is the only option to restore erectile function. Closing the tunica over an inflatable penile prosthesis in these patients can be challenging. We review our previous study which included 15 patients with severe corporeal or tunical fibrosis who underwent corporeal reconstruction with autologous rectus fascia to allow placement of an inflatable penile prosthesis. At a mean follow-up of 18 months (range 12 to 64, all patients had a prosthesis that was functioning properly without evidence of separation, herniation, or erosion of the graft. Sexual activity resumed at a mean time of 9 weeks (range 8 to 10. There were no adverse events related to the graft or its harvest. Use of rectus fascia graft for coverage of a tunical defect during a difficult penile prosthesis placement is surgically feasible, safe, and efficacious.

  14. Orbital exenteration and placement of a prosthesis in fish.

    Science.gov (United States)

    Nadelstein, B; Bakal, R; Lewbart, G A

    1997-09-01

    To develop a procedure for orbital exenteration and prosthesis placement in fish. Prospective study. 5 cultured hybrid striped bass (Morone saxatilis x M chrysops) ranging from 30 to 50 cm in length. Exenteration was performed, using a dorsal approach in which blunt dissection was performed in the circumorbital sulcus. The orbit was then dried, and simple interrupted sutures were placed, leaving 2 suture loops within the orbit. The orbit was filled with polyvinylsiloxane, and a prosthetic glass eye was seated in the polyvinylsiloxane. All fish retained the prosthesis and had satisfactory cosmetic results at the end of the 8-week study period. The increase in popularity of pet fish and abundance of valuable aquarium and show fish have led to heightened awareness of piscine ocular disease. Aquarium fish are often euthanatized because of disfiguring ocular problems. The technique described here for surgical exenteration and cosmetic orbital prosthesis placement in fish may extend the captive life of public display fish.

  15. The influence of the preliminary garter spring spacer simulator clamping force in the pressure tube spacer -calandria tube hook-up simulator aging behaviour

    International Nuclear Information System (INIS)

    Gyongyosi, T.; Deloreanu, G.; Puiu, D.; Corbescu, B.; Anghel, N.; Dinu, E.

    2016-01-01

    The garter spring spacer is a specially constructed torsion spring used to fit-out the CANDU 6 fuel channel. The pressure tube ageing decreases the gap to the calandria tube. Continuous gap decrease directly affects the garter spring spacers behavior during fuel channel assembly operation. The preliminary clamping force value of the garter spring spacer assembly is important for its ageing behavior. This paper briefly describes the experimental technological facilities used for conducted the experiments and highlights some of the important moments during an experiment carried out in laboratory conditions, without using pressurized boiled water and irradiation working conditions. The results analysis and some conclusions are outlined at the end, pointing out that a garter spring spacer preliminary clamping force increase reduces the vibration response signal amplitude, and does not lead to its relaxation. The paper is dedicated to specialists working in research and technological engineering. (authors)

  16. Automated Fiber Placement of Advanced Materials (Preprint)

    National Research Council Canada - National Science Library

    Benson, Vernon M; Arnold, Jonahira

    2006-01-01

    .... ATK has been working with the Air Force Research Laboratory to foster improvements in the BMI materials and in the fiber placement processing techniques to achieve rates comparable to Epoxy placement rates...

  17. Magnetic decoupling of ferromagnetic metals through a graphene spacer

    Energy Technology Data Exchange (ETDEWEB)

    Grimaldi, I.; Papagno, M. [Dipartimento di Fisica, Universitá della Calabria, Arcavacata di Rende (CS), 87036 (Italy); Ferrari, L. [Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Roma I-00133 (Italy); Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Trieste (Italy); Sheverdyaeva, P.M.; Mahatha, S.K. [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Trieste (Italy); Pacilé, D., E-mail: daniela.pacile@fis.unical.it [Dipartimento di Fisica, Universitá della Calabria, Arcavacata di Rende (CS), 87036 (Italy); Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Trieste (Italy); Carbone, C. [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Trieste (Italy)

    2017-03-15

    We study the magnetic coupling between different ferromagnetic metals (FMs) across a graphene (G) layer, and the role of graphene as a thin covalent spacer. Starting with G grown on a FM substrate (Ni or Co), we deposited on top at room temperature several FM metals (Fe, Ni, Co). By measuring the dichroic effect of 3p photoemission lines we detect the magnetization of the substrate and the sign of the exchange coupling in FM overlayer at room temperature. We show that the G layer magnetically decouples the FM metals. - Highlights: • The magnetic coupling between ferromagnets mediated by graphene is studied. • To this end, the linear dichroic effect in 3p photoemission lines is employed. • For selected junctions no magnetic coupling is attained through graphene. • Graphene inhibits the magnetic alignment that normally occurs between ferromagnets.

  18. Solution-processed organic tandem solar cells with embedded optical spacers

    NARCIS (Netherlands)

    Hadipour, Afshin; de Boer, Bert; Blom, Paul W. M.

    2007-01-01

    We demonstrate a solution-processed polymer tandem solar cell in which the two photoactive single cells are separated by an optical spacer. The use of an optical spacer allows for an independent optimization of both the electronic and optical properties of the tandem cell. The optical transmission

  19. Single electron transistor with P-type sidewall spacer gates.

    Science.gov (United States)

    Lee, Jung Han; Li, Dong Hua; Lee, Joung-Eob; Kang, Kwon-Chil; Kim, Kyungwan; Park, Byung-Gook

    2011-07-01

    A single-electron transistor (SET) is one of the promising solutions to overcome the scaling limit of the Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET). Up to now, various kinds of SETs are being proposed and SETs with a dual gate (DG) structure using an electrical potential barrier have been demonstrated for room temperature operation. To operate DG-SETs, however, extra bias of side gates is necessary. It causes new problems that the electrode for side gates and the extra bias for electrical barrier increase the complexity in circuit design and operation power consumption, respectively. For the reason, a new mechanism using work function (WF) difference is applied to operate a SET at room temperature by three electrodes. Its structure consists of an undoped active region, a control gate, n-doped source/drain electrodes, and metal/silicide or p-type silicon side gates, and a SET with metal/silicide gates or p-type silicon gates forms tunnel barriers induced by work function between an undoped channel and grounded side gates. Via simulation, the effectiveness of the new mechanism is confirmed through various silicide materials that have different WF values. Furthermore, by considering the realistic conditions of the fabrication process, SET with p-type sidewall spacer gates was designed, and its brief fabrication process was introduced. The characteristics of its electrical barrier and the controllability of its control gate were also confirmed via simulation. Finally, a single-hole transistor with n-type sidewall spacer gates was designed.

  20. Fully customized placement of orthodontic miniplates: a novel clinical technique

    Science.gov (United States)

    2014-01-01

    Introduction The initial stability and survival rate of orthodontic mini-implants are highly dependent on the amount of cortical bone at their insertion site. In areas with limited bone availability, mini-plates are preferred to provide effective skeletal anchorage. The purpose of this paper was to present a new clinical technique for the insertion of mini-plates. Methods In order to apply this new technique, a cone-beam image of the insertion area is required. A software (Galaxy Sirona, Bensheim, Germany) is used to construct a three-dimensional image of the scanned area and to virtually determine the exact location of the mini-plate as well as the position of the fixation screws. A stereolithographic model (STL) is then created by means of a three-dimensional scanner. Prior to its surgical insertion, the bone plate is adapted to the stereo-lithographic model. Finally, a custom transfer jig is fabricated in order to assist with accurate placement of the mini-plate intra-operatively. Results The presented technique minimizes intra-operative decision making, because the final position of the bone plate is determined pre-surgically. This significantly reduces the duration of the surgical procedure and improves its outcome. Conclusions A novel method for surgical placement of orthodontic mini-plates is presented. The technique facilitates accurate adaptation of mini-plates and insertion of retaining surgical screws; thereby enabling clinicians to more confidently increase the use of bone plates, especially in anatomical areas where the success of non-osseointegrated mini-screws is less favorable. PMID:24886597

  1. Designing a safety checklist for dental implant placement: a Delphi study.

    Science.gov (United States)

    Christman, Adam; Schrader, Stuart; John, Vanchit; Zunt, Susan; Maupome, Gerardo; Prakasam, Sivaraman

    2014-02-01

    Complications during and after dental implant placement can be a hindrance to successful treatment. Checklists are emerging as useful tools in error reduction in various fields. The authors selected a Delphi panel to explore the appropriate clinical practices involved in implant placement, with the objective of formulating a safety checklist that would aid in reducing errors. The authors administered a Delphi method survey to an expert panel of 24 board-certified periodontists to determine if consensus existed regarding the critical steps involved in implant placement. They defined consensus as 90 percent agreement among participants. Using the Delphi data, the authors designed a safety checklist for implant placement. The panelists generated 20 consensus statements regarding essential steps in implant placement. The authors divided the statements into preoperative, intraoperative and postoperative phases. To determine the rationale for consensus decisions, the authors conducted a thematic qualitative analysis of responses to all open-ended questionnaire items, asking panel members how or why a particular procedure was performed. The panelists reached a consensus regarding the steps they considered critical in implant placement. Further research is needed to assess the acceptance and effectiveness of this type of checklist in a clinical setting. Practical Implications. The authors developed a checklist that may be useful in reducing errors in placement of dental implants. If effective, this checklist ultimately will aid in minimizing risk and increasing implant success rates, especially for inexperienced practitioners, dental students, surgical residents and dental implant trainees (that is, dentists undergoing training to place implants through continuing education courses).

  2. Pros and cons of symmetrical dual-k spacer technology in hybrid FinFETs

    Science.gov (United States)

    Pradhan, K. P.; Andrade, M. G. C.; Sahu, P. K.

    2016-12-01

    The symmetrical dual-k spacer technology in hybrid FinFETs has been widely explored for better electrostatic control of the fin-based devices in nanoscale region. Since, high-k tangible spacer materials are broadly became a matter of study due to their better immunity to the short channel effects (SCEs) in nano devices. However, the only cause that restricts the circuit designers from using high-k spacer is the unreasonable increasing fringing capacitances. This work quantitatively analyzed the benefits and drawbacks of considering two different dielectric spacer materials symmetrically in either sides of the channel for the hybrid device. From the demonstrated results, the inclusion of high-k spacer predicts an effective reduction in off-state leakage along with an improvement in drive current. However, these devices have paid the cost in terms of a high total gate-to-gate capacitance (Cgg) that consequently results poor cutoff frequency (fT) and delay.

  3. Gastrojejunoscopy facilitates placement of a percutaneous transgastric jejunostomy in a patient with a pancreaticoduodenectomy and multiple-failed feeding tube placements

    Directory of Open Access Journals (Sweden)

    Jeffrey Forris Beecham Chick, MD, MPH, DABR

    2018-02-01

    Full Text Available Enteral access is one of the most common procedures performed in abdominal and interventional radiology. The surgical anatomy of the postoperative stomach may, however, make enteral access challenging. This report describes a patient with a pancreaticoduodenectomy complicated by a gastrojejunostomy leak who underwent 2 unsuccessful transoral endoscopic nasojejunal tube placements and 2 failed percutaneous gastrojejunostomy tube placements. Eventually, a gastrojejunostomy tube was placed utilizing percutaneous techniques with fluoroscopy assistance and gastrojejunoscopy guidance. A combined technique with fluoroscopy and endoscopy, both controlled by interventional radiology, may be useful in patients with complex postsurgical gastrointestinal anatomy who require enteral access.

  4. SURGICAL ANATOMY

    African Journals Online (AJOL)

    SURGICAL ANATOMY. Rare high origin of the radial artery: a bilateral, symmetrical ease. I. O. ()koro and B. C. J iburum. Department of Anatomy, College of Medicine, lrno State University, Owerri, Nigeria. Reprint requests to: Dr I. O. 0k0r0, Department of Anatomy, [mo State University, P. M. B. 2000. Owerri, Nigeria.

  5. SURGICAL TECHNIQUE

    African Journals Online (AJOL)

    Conclusion:Foraminotomy with or without discectomy is a simple posterior surgical approach to T B spine with good neurological outcome. It is adapted to our ... of the spine also referred to as. (HIV/AIDS) further challenge the outcome. These .... treatment; or for spinal cord or nerve root from 2 weeks depending on patient ...

  6. Intraoperative molds to create an articulating spacer for the infected knee arthroplasty.

    Science.gov (United States)

    Van Thiel, Geoffrey S; Berend, Keith R; Klein, Gregg R; Gordon, Alexander C; Lombardi, Adolph V; Della Valle, Craig J

    2011-04-01

    Chronic infections in TKA have been traditionally treated with a two-stage protocol incorporating a temporary antibiotic-loaded cement spacer. The use of a static as opposed to an articulating spacer is controversial. Some surgeons believe a static spacer results in a higher rate of infection eradication, whereas others believe an articulating spacer provides equivalent rates of infection control with improved function between stages and the potential for better eventual range of motion. We determined the rates of infection control and postoperative function for an articulating all-cement antibiotic spacer fashioned intraoperatively from prefabricated silicone molds. We retrospectively reviewed 60 patients with an infected TKA using the same cement-on-cement articulating spacer. A minimum of 4 g antibiotic per package of cement was used when making the spacer. Complications and pre- and postoperative knee flexion, extension, and Knee Society scores were recorded. Bone loss associated with the spacer was determined radiographically and by intraoperative inspection of the bony surfaces at the second stage. Minimum followup was 24 months (mean, 35 months; range, 24-51 months). Seven patients (12%) became reinfected, four with an organism different from that identified at the index resection arthroplasty. One spacer femoral component broke between stages but did not require any specific treatment. We identified no bone loss between stages and no complications related to the cement-on-cement articulation. The mean pretreatment Knee Society scores of 53 improved to 79. The mean preoperative flexion of 90.6º improved to 101.3º at final followup. An articulating antibiotic spacer was associated with control of a deep periprosthetic infection in 88% of patients while allowing range of motion between stages. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  7. BWR fuel assembly with improved spacer and fuel bundle design for enhanced thermal-hydraulic performance

    International Nuclear Information System (INIS)

    Mildrum, C.M.; Taleyarkhan, R.P.

    1987-01-01

    In a fuel assembly having a bundle of elongated fuel rods disposed in side-by-side relationship so as to form an array of spaced fuel rods, an outer tubular flow channel surrounding the fuel rods so as to direct flow of coolant/moderator fluid along the fuel rods, a hollow water cross extending centrally through and interconnected with the outer flow channel so as to divide the channel into separate compartments and the bundle of fuelrods into a plurality of mini-bundles thereof being disposed in the compartments, and spacers axially displaced along the fuel rods in each of the mini-bundles thereof. Each spacer is composed of inner and outer means which together define spacer cells at corner, side and interior locations of the spacer and have respective protrusions formed thereon which extend into cells so as to maintain the fuel rods received through the spacer cells in laterally spaced relationships. The improvement is described which comprises: (a) a generally uniform poison coating within at least a majority of the fuel rods; (b) a predetermined pattern of fuel enrichment with respect to the fuel rods of each mini-bundle thereof which together with the uniform poison coating within the fuel rods ensures that the packing powers of the fuel rods in the corner and side cells of the spacers are less than the peaking power of a leading one of the fuel rods in the interior cells of the spacers; and (c) each of the fuel rods being received through the cells of each spacer having a diametric size smaller than that of each of the fuel rods received through the side and interior cells of each spacer, the diametric sizes of each of the fuel rods received through the side and interior cells of each spacer being generally equal

  8. placements des gouverneurs

    International Development Research Centre (IDRC) Digital Library (Canada)

    André Lavoie

    Transit. Tout endroit qui n'est pas considéré comme la destination où l'on se rend par affaires. Voyageur. Désigne un gouverneur dans le contexte du présent règlement. 5. Rôles et responsabilités. 5.1. Personnes participant au processus lié aux déplacements des gouverneurs. Toutes les personnes, dont les gouverneurs, ...

  9. In vitro performance of three combinations of spacers and pressurized metered dose inhalers for treatment in children

    DEFF Research Database (Denmark)

    Berg, E; Madsen, J; Bisgaard, H

    1998-01-01

    The performance of pressurized metered dose inhalers (pMDIs) and spacers in correct dose recommendations is important, but limited information on dose delivery and fine-particle dose from different combinations of spacers and pMDIs is available. In this study, three combinations of spacers and p...... and spacers, with the NebuChamber giving the highest dose, both as delivered dose and in droplets account for these differences....

  10. Humanitarian engineering placements in our own communities

    Science.gov (United States)

    VanderSteen, J. D. J.; Hall, K. R.; Baillie, C. A.

    2010-05-01

    There is an increasing interest in the humanitarian engineering curriculum, and a service-learning placement could be an important component of such a curriculum. International placements offer some important pedagogical advantages, but also have some practical and ethical limitations. Local community-based placements have the potential to be transformative for both the student and the community, although this potential is not always seen. In order to investigate the role of local placements, qualitative research interviews were conducted. Thirty-two semi-structured research interviews were conducted and analysed, resulting in a distinct outcome space. It is concluded that local humanitarian engineering placements greatly complement international placements and are strongly recommended if international placements are conducted. More importantly it is seen that we are better suited to address the marginalised in our own community, although it is often easier to see the needs of an outside populace.

  11. Surgical Navigation

    DEFF Research Database (Denmark)

    Azarmehr, Iman; Stokbro, Kasper; Bell, R. Bryan

    2017-01-01

    body removal, respectively. The average technical system accuracy and intraoperative precision reported were less than 1 mm and 1 to 2 mm, respectively. In general, SN is reported to be a useful tool for surgical planning, execution, evaluation, and research. The largest numbers of studies and patients......Purpose: This systematic review investigates the most common indications, treatments, and outcomes of surgical navigation (SN) published from 2010 to 2015. The evolution of SN and its application in oral and maxillofacial surgery have rapidly developed over recent years, and therapeutic indications...... surgery, skull-base surgery, and foreign body removal were the areas of interests. Results: The search generated 13 articles dealing with traumatology; 5, 6, 2, and 0 studies were found that dealt with the topics of orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign...

  12. Bone grafting simultaneous to implant placement. Presentation of a case.

    Science.gov (United States)

    Peñarrocha-Diago, Miguel; Gómez-Adrián, Maria Dolores; García-Mira, Berta; Ivorra-Sais, Mariola

    2005-01-01

    Bone defects at mandibular alveolar crest level complicate the placement of dental implants in the ideal location. Surgical reconstruction using autologous bone grafts allows implant fixation in an esthetic and functional manner. We describe a patient with large mandibular bone loss secondary to periodontal inflammatory processes. Reconstruction of the mandibular alveolar process was carried out using onlay block bone grafts harvested from the mandible. The grafts were stabilized by positioning the dental implants through them--a procedure that moreover afforded good primary implant fixation. After two years of follow-up the clinical and radiological outcome is good. In the lower jaw, where bone regeneration is complicated, we were able to achieve good results in this patient--minimizing the corresponding waiting time by grafting and placing the implants in the same surgical step.

  13. A Study on Cell Size of Irradiated Spacer Grid for PWR Fuel

    International Nuclear Information System (INIS)

    Jin, Y. G.; Kim, G. S.; Ryu, W. S. and others

    2014-01-01

    The spacer grids supporting the fuel rods absorb vibration impacts due to the reactor coolant flow, and grid spring force decreases under irradiation. This reduction of contact force might cause grid-to-rod fretting wear. The fretting failure of the fuel rod is one of the recent significant issues in the nuclear industry from an economical as well as a safety concern. Thus, it is important to understand the characteristics of cell spring behavior and the change in size of grid cells for an irradiated spacer grid. In the present study, the dimensional measurement of a spacer grid was conducted to investigate the cell size of an irradiated spacer grid in a hot cell at IMEF (Irradiated Materials Examination Facility) of KAERI. To evaluate the fretting wear performance of an irradiated spacer grid, hot cell tests were carried out at IMEF of KAERI. Hot cell examinations include dimensional measurements for the irradiated spacer grid. The change of cell sizes was dependent on the direction of the spacer grids, leading to significant gap variations. It was found that the change in size of the cell springs due to irradiation-induced stress relaxation and creep during the fuel residency in the reactor core affect the contact behavior between the fuel rod and the cell spring

  14. Detection and repositioning of tight fighting annulus spacers in CANDU® fuel channels

    Energy Technology Data Exchange (ETDEWEB)

    Hersak, G.; Kittmer, A. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Goszczynski, J. [Candu Energy Inc., Mississauga, Ontario (Canada); Kazimer, D. [Bruce Power, Tiverton, Ontario (Canada)

    2014-06-15

    The latest generation of CANDU® reactors has been constructed with tight-fitting annulus spacers to maintain the annular gap between the inner pressure tubes and the outer calandria tubes. These spacers cannot be detected and repositioned with the existing Spacer Location and Repositioning (SLAR) process, which is designed to work with loose-fitting annulus spacers. There is currently no established technology to detect and reposition tight-fitting annulus spacers. Atomic Energy of Canada Limited has been performing research and development to locate and move tight-fitting annulus spacers using Modal Detection and Repositioning (MODAR) technology since 2005 and is currently working in collaboration with Candu Energy and Bruce Power on a production system to be deployed for an In-reactor demonstration in the next year. The MODAR technology uses controlled vibrations on a short, isolated length of pressure tube to locate and reposition tight-fitting annulus spacers. MODAR technology will allow the utilities to demonstrate fuel channel integrity to the regulator and obtain approval for additional years of reactor operation. This paper briefly describes the technology and provides an overview of the tool testing and development. (author)

  15. Evaluation of spacer grid spring characteristics by means of physical tests and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schettino, Carlos Frederico Mattos, E-mail: carlosschettino@inb.gov.br [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil)

    2017-11-01

    Among all fuel assemblies' components, the spacer grids play an important structural role during the energy generation process, mainly due for its primary functional requirement, that is, to provide fuel rod support. The present work aims to evaluate the spring characteristics of a specific spacer grid design used in a PWR fuel assembly type 16 x 16. These spring characteristics comprises the load versus deflection capability and its spring rate, which are very important, and also mandatory, to be correctly established in order to preclude spacer grid spring and fuel rod cladding fretting during operation, as well as prevent an excessive fuel rod buckling. This study includes physical tests and numerical simulation. The tests were performed on an adapted load cell mechanical device, using as a specimen a single strap of the spacer grid. Three numerical models were prepared using the Finite Element Method, with the support of the commercial code ANSYS. One model was built to validate the simulation according to the performed physical test, the others were built inserting a gradient of temperature (Beginning Of Life hot condition) and to evaluate the spacer grid spring characteristics in End Of Life condition. The obtained results from physical test and numerical model have shown a good agreement between them, therefore validating the simulation. The obtained results from numerical models make available information regarding the spacer grid design purpose, such as the behavior of the fuel rod cladding support during operation. Therewith, these evaluations could be useful to improve the spacer grid design. (author)

  16. Efficient double-emitting layer inverted organic light-emitting devices with different spacer layers

    Science.gov (United States)

    Nie, Qu-yang; Zhang, Fang-hui

    2017-09-01

    Double-emitting layer inverted organic light-emitting devices (IOLEDs) with different spacer layers were investigated, where 2,20,7,70-tetrakis(carbazol-9-yl)-9,9-spirobifluorene (CBP), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen) and 4,40,400-tris(N-carbazolyl)-triphenylamine (TCTA) were used as spacer layers, respectively, and GIr1 and R-4b were used as green and red guest phosphorescent materials, respectively. The results show that the device with BCP spacer layer has the best performance. The maximum current efficiency of the BCP spacer layer device reaches up to 24.15 cd·A-1 when the current density is 3.99 mA·cm-2, which is 1.23 times bigger than that of the CBP spacer layer device. The performance is better than that of corresponding conventional device observably. The color coordinate of the device with BCP spacer layer only changes from (0.625 1, 0.368 0) to (0.599 5, 0.392 8) when the driving voltage increases from 6 V to 10 V, so it shows good stability in color coordinate, which is due to the adoption of the co-doping evaporation method for cladding luminous layer and the effective restriction of spacer layer to carriers in emitting layer.

  17. Cochlear implant simulator for surgical technique analysis

    Science.gov (United States)

    Turok, Rebecca L.; Labadie, Robert F.; Wanna, George B.; Dawant, Benoit M.; Noble, Jack H.

    2014-03-01

    Cochlear Implant (CI) surgery is a procedure in which an electrode array is inserted into the cochlea. The electrode array is used to stimulate auditory nerve fibers and restore hearing for people with severe to profound hearing loss. The primary goals when placing the electrode array are to fully insert the array into the cochlea while minimizing trauma to the cochlea. Studying the relationship between surgical outcome and various surgical techniques has been difficult since trauma and electrode placement are generally unknown without histology. Our group has created a CI placement simulator that combines an interactive 3D visualization environment with a haptic-feedback-enabled controller. Surgical techniques and patient anatomy can be varied between simulations so that outcomes can be studied under varied conditions. With this system, we envision that through numerous trials we will be able to statistically analyze how outcomes relate to surgical techniques. As a first test of this system, in this work, we have designed an experiment in which we compare the spatial distribution of forces imparted to the cochlea in the array insertion procedure when using two different but commonly used surgical techniques for cochlear access, called round window and cochleostomy access. Our results suggest that CIs implanted using round window access may cause less trauma to deeper intracochlear structures than cochleostomy techniques. This result is of interest because it challenges traditional thinking in the otological community but might offer an explanation for recent anecdotal evidence that suggests that round window access techniques lead to better outcomes.

  18. Characterization of feed channel spacer performance using geometries obtained by X-ray computed tomography

    KAUST Repository

    Haaksman, Viktor A.

    2016-09-09

    Spiral-wound membrane modules used in water treatment for water reuse and desalination make use of spacer meshes for keeping the membrane leaves apart and for enhancing the mass transfer. Computational fluid dynamics (CFD) has gained importance in the design of new spacers with optimized hydrodynamic characteristics, but this requires a precise description of the spacer geometry. This study developed a method to obtain accurate three-dimensional (3-D) geometry representations for any given spacer design from X-ray computed tomography (CT) scans. The method revealed that the filaments of industrial spacers have a highly variable cross-section size and shape, which impact the flow characteristics in the feed channel. The pressure drop and friction factors were calculated from numerical simulations on five commercially available feed spacers used in practice. Model solutions compared well to experimental data measured using a flow cell for average velocities up to 0.2 m/s, as used in industrial reverse osmosis and nanofiltration membrane operations. A newly-proposed spacer geometry with alternating strand thickness was tested, which was found to yield a lower pressure drop while being highly efficient in converting the pumping power into membrane shear. Numerical model solutions using CFD with geometries from CT scans were closer to measurements than those obtained using the traditional circular cross-section strand simplification, indicating that CT scans are very well suitable to approximate real feed spacer geometries. By providing detailed insight on the spacer filament shape, CT scans allow better quantification of local distribution of velocity and shear, possibly leading to more accurate estimations of fouling and concentration polarization. © 2016 Elsevier B.V.

  19. Computer guided pre-operative planning and dental implant placement

    Directory of Open Access Journals (Sweden)

    Dušan Grošelj

    2007-05-01

    Full Text Available Background: Implants in dentistry are, besides fixed, removable and maxillofacial prosthodontics, one of the reliable possibility to make functional and aesthetic rehabilitation of the edentulism. Surgical and prosthodontic implant complications are often an inattentive consequence of wrong diagnosis, planning, and placement. In this article we present a technique using a highly advanced software program along with a rapid prototyping technology named stereolithography. A planning software for implant placement needs basically the high quality computed tomographic scan of one or both jaws for making accurate preoperative diagnostics and 3D preoperative plan. Later individual drill guide is designed and generated based on both the CT images and the preoperative planning. The patient specific drill guide transfers the virtual planning to the patient’s mouth at time of surgery.Conclusions: The advantages of computer guided implantology are the better prepared surgery with visualisation of critical anatomic structures, assessment of available bone and data about bone quality, increased confidence for the surgeon, deceased operative time, less frequent use of bone grafts, higher quality of collaboration between specialists and prosthetic lab and better communication with patients. Radiographic examination of the operation field for computer guided planning for implant placement is due to high costs justified as the most important information source on the areas to be implanted.

  20. Placement of replace select Ti-Unite-coated type implants using a combination of immediate and submerge techniques after tooth extraction

    Directory of Open Access Journals (Sweden)

    Coen Pramono D

    2006-06-01

    Full Text Available The high success rate of immediate implant placement both in the anterior and posterior regions were reported by many authors, therefore applying this techniques can be considered as a safe surgical procedure and minimizing the dental office visit for patient satisfaction. This paper reports the outcome of immediate placement of implants following extraction of anterior maxillary teeth. Combination technique of immediate and submerge implant placements including bone grafting procedure were used. Four implants with TiUnite surface type were placed immediately in two patients with the short-term result indicated that this technique may serve as a simple and safe procedure for immediate implant placement. It was concluded that immediate implant placement technique combined with TiUnite implant surface was successful in treating region directly after tooth extraction therefore this technique can be use as an alternative surgical method for dental implant rehabilitation.

  1. Patient-specific port placement for laparoscopic surgery using atlas-based registration

    Science.gov (United States)

    Enquobahrie, Andinet; Shivaprabhu, Vikas; Aylward, Stephen; Finet, Julien; Cleary, Kevin; Alterovitz, Ron

    2013-03-01

    Laparoscopic surgery is a minimally invasive surgical approach, in which abdominal surgical procedures are performed through trocars via small incisions. Patients benefit by reduced postoperative pain, shortened hospital stays, improved cosmetic results, and faster recovery times. Optimal port placement can improve surgeon dexterity and avoid the need to move the trocars, which would cause unnecessary trauma to the patient. We are building an intuitive open source visualization system to help surgeons identify ports. Our methodology is based on an intuitive port placement visualization module and atlas-based registration algorithm to transfer port locations to individual patients. The methodology follows three steps:1) Use a port placement visualization module to manually place ports in an abdominal organ atlas. This step generates port-augmented abdominal atlas. This is done only once for a given patient population. 2) Register the atlas data with the patient CT data, to transfer the prescribed ports to the individual patient 3) Review and adjust the transferred port locations using the port placement visualization module. Tool maneuverability and target reachability can be tested using the visualization system. Our methodology would decrease the amount of physician input necessary to optimize port placement for each patient case. In a follow up work, we plan to use the transferred ports as starting point for further optimization of the port locations by formulating a cost function that will take into account factors such as tool dexterity and likelihood of collision between instruments.

  2. Increase of the electron mobility in HEMT heterostructures with composite spacers containing AlAs nanolayers

    Energy Technology Data Exchange (ETDEWEB)

    Vinichenko, A. N., E-mail: vanaxel@gmail.com; Gladkov, V. P.; Kargin, N. I.; Strikhanov, M. N.; Vasil’evskii, I. S. [National Research Nuclear University “MEPhI” (Russian Federation)

    2014-12-15

    The effect of the hybridization of quantum states on electron transport in a two-barrier quantum well δ-doped through a spacer layer at the limit of heavy doping is shown theoretically and experimentally. A method for increasing the electron mobility in the quantum well by suppressing the tunnel coupling with the donor region through the introduction of an AlAs nanobarrier into the spacer layer is proposed. It is experimentally shown that, in the samples with a shallow quantum well, the AlAs nanobarrier introduced into the spacer layer provides a larger than threefold increase in the electron mobility at low temperatures.

  3. Modulation of porphyrin photoluminescence by nanoscale spacers on silicon substrates

    International Nuclear Information System (INIS)

    Fang, Y.C.; Zhang, Y.; Gao, H.Y.; Chen, L.G.; Gao, B.; He, W.Z.; Meng, Q.S.; Zhang, C.; Dong, Z.C.

    2013-01-01

    We investigate photoluminescence (PL) properties of quasi-monolayered tetraphenyl porphyrin (TPP) molecules on silicon substrates modulated by three different nanoscale spacers: native oxide layer (NOL), hydrogen (H)-passivated layer, and Ag nanoparticle (AgNP) thin film, respectively. In comparison with the PL intensity from the TPP molecules on the NOL-covered silicon, the fluorescence intensity from the molecules on the AgNP-covered surface was greatly enhanced while that for the H-passivated surface was found dramatically suppressed. Time-resolved fluorescence spectra indicated shortened lifetimes for TPP molecules in both cases, but the decay kinetics is believed to be different. The suppressed emission for the H-passivated sample was attributed to the weaker decoupling effect of the monolayer of hydrogen atoms as compared to the NOL, leading to increased nonradiative decay rate; whereas the enhanced fluorescence with shortened lifetime for the AgNP-covered sample is attributed not only to the resonant excitation by local surface plasmons, but also to the increased radiative decay rate originating from the emission enhancement in plasmonic “hot-spots”.

  4. Modulation of porphyrin photoluminescence by nanoscale spacers on silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Y.C. [Department of Vacuum Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009 (China); HFNL, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Zhang, Y.; Gao, H.Y.; Chen, L.G.; Gao, B.; He, W.Z.; Meng, Q.S.; Zhang, C. [HFNL, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Dong, Z.C., E-mail: zcdong@ustc.edu.cn [HFNL, University of Science and Technology of China, Hefei, Anhui, 230026 (China)

    2013-11-15

    We investigate photoluminescence (PL) properties of quasi-monolayered tetraphenyl porphyrin (TPP) molecules on silicon substrates modulated by three different nanoscale spacers: native oxide layer (NOL), hydrogen (H)-passivated layer, and Ag nanoparticle (AgNP) thin film, respectively. In comparison with the PL intensity from the TPP molecules on the NOL-covered silicon, the fluorescence intensity from the molecules on the AgNP-covered surface was greatly enhanced while that for the H-passivated surface was found dramatically suppressed. Time-resolved fluorescence spectra indicated shortened lifetimes for TPP molecules in both cases, but the decay kinetics is believed to be different. The suppressed emission for the H-passivated sample was attributed to the weaker decoupling effect of the monolayer of hydrogen atoms as compared to the NOL, leading to increased nonradiative decay rate; whereas the enhanced fluorescence with shortened lifetime for the AgNP-covered sample is attributed not only to the resonant excitation by local surface plasmons, but also to the increased radiative decay rate originating from the emission enhancement in plasmonic “hot-spots”.

  5. APPLICATIONS OF SPACERS MADE WITH DOUBLE BAR RASCHEL MACHINE

    Directory of Open Access Journals (Sweden)

    DÍAZ-GARCÍA Pablo

    2016-05-01

    Full Text Available Nowadays, textile technologies develop to adapt their different techniques for creating new products for the different sectors of application every day. Particularly, warp knitted fabrics and warp-knitting technology have applications in all different groups of technical textiles. It could be the most applied technique, the most versatile technology to develop new textile products for the new textile market. Warp knitted fabrics play the most important role among the technical textile fabrics. This technology is used in different product groups such as mobile textiles (car seat covers, dashboard cover, industrial textiles (composites, medical textiles (anti-decubitus blankets, sports textiles and foundation garments (bra cups, pads for swimwear. This study presents some examples of the application of this technology in some markets Within the market of technical textile, medical textile has an increasing relevance and knitted fabrics and knitting technology, at the same time, play a very important role in the fields of technical and medical textiles. Studies have demonstrated that knitted structures possess excellent mechanical properties and can promote more effective regenerative medicine, tissue repair, ligament, tendon cartilage, reconstruction, etc. The aim of this paper is to present different possibilities of textiles developed with this kind of structures, to present different alternatives, different examples of products obtained with this kind of textile structure combined with the correct kind of textile fiber. In this kind of technology, double-bar Raschel machines used for producing three-dimensional textiles, spacers, play an important role.

  6. Surgical endodontics.

    Science.gov (United States)

    Carrotte, P

    2005-01-22

    Root canal treatment usually fails because infection remains within the root canal. An orthograde attempt at re-treatment should always be considered first. However, when surgery is indicated, modern microtechniques coupled with surgical magnification will lead to a better prognosis. Careful management of the hard and soft tissues is essential, specially designed ultrasonic tips should be used for root end preparation which should ideally be sealed with MTA. All cases should be followed up until healing is seen, or failure accepted, and should form a part of clinical audit.

  7. Effects of grid spacer with mixing vane on entrainments and depositions in two-phase annular flows

    Directory of Open Access Journals (Sweden)

    Akimaro Kawahara

    2015-06-01

    Full Text Available The effects of mixing vanes (MVs attached to a grid spacer on the characteristics of air–water annular flows were experimentally investigated. To know the effects, a grid spacer with or without MV was inserted in a vertical circular pipe of 16-mm internal diameter. For three cases (i.e., no spacer, spacer without MV, and spacer with MV, the liquid film thickness, liquid entrainment fraction, and deposition rate were measured by the constant current method, single liquid film extraction method, and double liquid film extraction method, respectively. The MVs significantly promote the re-deposition of liquid droplets in the gas core flow into the liquid film on the channel walls. The deposition mass transfer coefficient is three times higher for the spacer with MV than for the spacer without MV, even for cases 0.3-m downstream from the spacer. The liquid film thickness becomes thicker upstream and downstream for the spacer with MV, compared with the thickness for the spacer without MV and for the case with no spacer.

  8. Predictable periimplant gingival esthetics: use of the natural tooth as a provisional following implant placement.

    Science.gov (United States)

    Margeas, Robert C

    2006-01-01

    Maintaining the interdental papilla and bone height following implant placement has been a challenge for the restorative dentist. Bone resorption following anterior tooth extraction is common and often compromises the esthetics of the final restoration. The tissue must be maintained during the surgical and healing phases to achieve an esthetic outcome. Using the patient's natural tooth as a provisional can help maintain the volume and support the papilla. This article describes a technique to achieve maximum esthetics and preservation of tissue following tooth extraction and implant placement. By using the patient's extracted natural tooth, the tissue should maintain itself with minimal recession. This will allow for a more esthetic outcome.

  9. Non linear fe analysis on the static buckling behavior of the spacer grid structures

    International Nuclear Information System (INIS)

    Song, K.N.; Yoon, K.H.

    2001-01-01

    In this study considered is the static buckling behavior of spacer grids in the fuel assembly, which are required to have a sufficient strength against an accident like earthquake. Special attention is given to the finite element modeling of the spot-welding and the constraints between the spacer strips assembled together: it is found that a proper treatment of the constraints is critical for accurate assessment of the buckling behavior including strain localization at the point of spot welding. The buckling strength of the 17 x 17 spacer grid, which is difficult to analyze due to a large number of degrees of freedom, is estimated from analysis for the smaller models 3 x 3, 5 x 5, 7 x 7, and 9 x 9 spacer grids. (authors)

  10. Impact of a Protective Vest and Spacer Garment on Exercise-Heat Strain

    National Research Council Canada - National Science Library

    Cheuvront, Samuel N; Goodman, Daniel A; Kenefick, Robert W; Montain, Scott J; Sawka, Michael N

    2008-01-01

    ...). Volunteers wore the US Army battle dress uniform (trial B), B + protective vest (trial P), and B + P + spacer garment (trial S). Biophysical clothing properties were determined and found similar to many law enforcement, industry, and sports ensembles...

  11. A simulation methodology of spacer grid residual spring deflection for predictive and interpretative purposes

    International Nuclear Information System (INIS)

    Kim, K. T.; Kim, H. K.; Yoon, K. H.

    1994-01-01

    The in-reactor fuel rod support conditions against the fretting wear-induced damage can be evaluated by spacer grid residual spring deflection. In order to predict the spacer grid residual spring deflection as a function of burnup for various spring designs, a simulation methodology of spacer grid residual spring deflection has been developed and implemented in the GRIDFORCE program. The simulation methodology takes into account cladding creep rate, initial spring deflection, initial spring force, and spring force relaxation rate as the key parameters affecting the residual spring deflection. The simulation methodology developed in this study can be utilized as an effective tool in evaluating the capability of a newly designed spacer grid spring to prevent the fretting wear-induced damage

  12. The effect of endoskeleton on antibiotic impregnated cement spacer for treating deep hip infection

    Directory of Open Access Journals (Sweden)

    Hsu Wei-Hsiu

    2011-01-01

    Full Text Available Abstract Backgrounds A two-stage revision arthroplasty was suggested optimal treatment for deep infections in hip joint. The effect of endoskeleton of cement spacers on the interim function and infection control remains unclear. Methods From Jan. 2004 to Dec. 2007, we collected a prospective cohort of consecutive 34 patients who treated with two-stage revision total hip arthroplasty for deep infection of hip joint. In group 1, fifteen patients were treated by a novel design augmented with hip compression screw while nineteen patients were treated by traditional design in group 2. Results No fracture of cement spacer occurred in group 1 while 6 cases developed spacer failure in group 2. (p Conclusions Patients being treated for deep infection of hip joint using cement spacer augmented with stronger endoskeleton have lower pain levels and better joint function between stages.

  13. Spacer geometry and particle deposition in spiral wound membrane feed channels

    KAUST Repository

    Radu, A.I.

    2014-11-01

    Deposition of microspheres mimicking bacterial cells was studied experimentally and with a numerical model in feed spacer membrane channels, as used in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane systems. In-situ microscopic observations in membrane fouling simulators revealed formation of specific particle deposition patterns for different diamond and ladder feed spacer orientations. A three-dimensional numerical model combining fluid flow with a Lagrangian approach for particle trajectory calculations could describe very well the in-situ observations on particle deposition in flow cells. Feed spacer geometry, positioning and cross-flow velocity sensitively influenced the particle transport and deposition patterns. The deposition patterns were not influenced by permeate production. This combined experimental-modeling approach could be used for feed spacer geometry optimization studies for reduced (bio)fouling. © 2014 Elsevier Ltd.

  14. A Facile Technique to Make Articulating Spacers for Infected Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Yu-Ping Su

    2009-03-01

    Conclusion: Treating infected total knee arthroplasty with these self-made articulating spacers eradicates infection effectively, improves the life quality before reimplantation and provides good final results without significant complications.

  15. Computer-Aided Design Method of Warp-Knitted Jacquard Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Li Xinxin

    2016-06-01

    Full Text Available Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.

  16. CRISPR Spacer Arrays for Detection of Viral Signatures from Acidic Hot Springs

    Science.gov (United States)

    Snyder, J. C.; Bateson, M. M.; Suciu, D.; Young, M. J.

    2010-04-01

    Viruses are the most abundant life-like entities on the planet Earth. Using CRISPR spacer sequences, we have developed a microarray-based approach to detecting viral signatures in the acidic hot springs of Yellowstone.

  17. Annular flow in rod-bundle: Effect of spacer on disturbance waves

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Son H.; Kunugi, Tomoaki

    2016-08-01

    A high-speed camera technique is used to study the effect of spacers on the disturbance waves present in annular two-phase flow within a rod-bundle geometry. Images obtained using a backlight configuration to visualize the spacer-wave interactions at the micro-scale resolution (in time and space) are discussed. This paper also presents additional images obtained using a reflected light configuration which provides new observations of the disturbance waves. These images show the separation effect caused by the spacer on the liquid film in which the size of generated liquid droplets can be controlled by the gas superficial velocity. Furthermore, the data confirm that the spacer breaks the circumferential coherent structures of the waves.

  18. Product placement of computer games in cyberspace.

    Science.gov (United States)

    Yang, Heng-Li; Wang, Cheng-Shu

    2008-08-01

    Computer games are considered an emerging media and are even regarded as an advertising channel. By a three-phase experiment, this study investigated the advertising effectiveness of computer games for different product placement forms, product types, and their combinations. As the statistical results revealed, computer games are appropriate for placement advertising. Additionally, different product types and placement forms produced different advertising effectiveness. Optimum combinations of product types and placement forms existed. An advertisement design model is proposed for use in game design environments. Some suggestions are given for advertisers and game companies respectively.

  19. Feasibility Study of Interactive Game Technologies to Improve Experience with Inhaler Spacer Devices in Young Children

    OpenAIRE

    Aslam, Tariq; Shakir, Savana; Murray, Clare

    2016-01-01

    IntroductionThe correct use of inhaler devices with facemasks and spacers in young children can be difficult for both children and parents, resulting in distress for both, poor adherence and ineffective drug delivery. The aim of this study was to develop and assess the utility and impact of an interactive electronic game designed to improve the experience of spacer devices in young asthmatic children.MethodsThe Respiratory Aid For Inhaler (RAFIhaler) technology consists of a smartphone mounte...

  20. Biofouling patterns in spacer filled channels: High resolution imaging for characterization of heterogeneous biofilms

    KAUST Repository

    Staal, Marc

    2017-08-15

    Biofilms develop in heterogeneous patterns at a µm scale up to a cm scale, and patterns become more pronounced when biofilms develop under complex hydrodynamic flow regimes. Spatially heterogeneous biofilms are especially known in spiral wound reverse osmosis (RO) and nanofiltration (NF) membrane filtration systems used for desalination and wastewater reuse to produce high quality (drinking) water. These spiral wound membrane modules contain mesh-like spacer structures used to create an intermembrane space and improve water mixing. Spacers create inhomogeneous water flow patterns resulting in zones favouring biofilm growth, possibly leading to biofouling thus hampering water production. Oxygen sensing planar optodes were used to visualize variations in oxygen decrease rates (ODR). ODR is an indication of biofilm activity. In this study, ODR images of multiple repetitive spacer areas in a membrane fouling simulator were averaged to produce high resolution, low noise ODR images. Averaging 40 individual spacer areas improved the ODR distribution image significantly and allowed comparison of biofilm patterning over a spacer structure at different positions in an RO filter. This method clearly showed that most active biofilm accumulated on and in direct vicinity of the spacer. The averaging method was also used to calculate the deviation of ODR patterning from individual spacer areas to the average ODR pattern, proposing a new approach to determine biofilm spatial heterogeneity. This study showed that the averaging method can be applied and that the improved, averaged ODR images can be used as an analytical, in-situ, non-destructive method to assess and quantify the effect of membrane installation operational parameters or different spacer geometries on biofilm development in spiral wound membrane systems characterized by complex hydrodynamic conditions.

  1. Does exchange arthroplasty of an infected shoulder prosthesis provide better eradication rate and better functional outcome, compared to a permanent spacer or resection arthroplasty? a systematic review.

    Science.gov (United States)

    George, D A; Volpin, A; Scarponi, S; Haddad, F S; Romanò, C L

    2016-02-01

    The best surgical modality for treating chronic periprosthetic shoulder infections has not been established, with a lack of randomised comparative studies. This systematic review compares the infection eradication rate and functional outcomes after single- or two-stage shoulder exchange arthroplasty, to permanent spacer implant or resection arthroplasty. Full-text papers and those with an abstract in English published from January 2000 to June 2014, identified through international databases, such as EMBASE and PubMed, were reviewed. Those reporting the success rate of infection eradication after a single-stage exchange, two-stage exchange, resection arthroplasty or permanent spacer implant, with a minimum follow-up of 6 months and sample size of 5 patients were included. Eight original articles reporting the results after resection arthroplasty (n = 83), 6 on single-stage exchange (n = 75), 13 on two-stage exchange (n = 142) and 8 papers on permanent spacer (n = 68) were included. The average infection eradication rate was 86.7 % at a mean follow-up of 39.8 months (SD 20.8) after resection arthroplasty, 94.7 % at 46.8 months (SD 17.6) after a single-stage exchange, 90.8 % at 37.9 months (SD 12.8) after two-stage exchange, and 95.6 % at 31.0 months (SD 9.8) following a permanent spacer implant. The difference was not statistically significant (p = 0.650). Regarding functional outcome, patients treated with single-stage exchange had statistically significant better postoperative Constant scores (mean 51, SD 13) than patients undergoing a two-stage exchange (mean 44, SD 9), resection arthroplasty (mean 32, SD 7) or a permanent spacer implant (mean 31, SD 9) (p = 0.029). However, when considering studies comparing pre- and post-operative Constant scores, the difference was not statistically significant. This systematic review failed to demonstrate a clear difference in infection eradication and functional improvement between all four

  2. Testing for hydraulic characteristics of HIPER spacer grids

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kyu; Lee, Kang Hee; Kang, Heung Seok; Lee, Young Ho; Kim, Jae Yong; Yoon, Kyung Ho

    2009-12-15

    The Korea Nuclear Fuel Co. requested the high frequency flow-induced vibration and pressure drop tests of top, mid, IFM, bottom grid candidates of HIPER and protective grid candidates of a commercial fuel. The following results were obtained for each test. 1) High frequency flow-induced vibration of HIPER spacer grids Measured maximum vibration amplitude of the HIPER mid grid was under 21 mm/s at lower region of the grid's center spring. The peak vibration amplitudes of the upper, IFM, and bottom grids were 5{approx}10 times less than that of the mid grid. Peak frequency associated with the peak amplitude have gradually increased with the flow velocity. This suggested that a high frequency vibration of grid was originated from the vortex shedding due to the thickness edge of grid strap. 2) Hydraulic vibration test of protective grids for a commercial fuel Peak vibration amplitudes of 16x16 type fuel protective grids were above 200 mm/s at the frontal direction of HyGrid 4. There might be a strong resonance near at the measurement point of the grid. Peak vibration amplitude of 17x17 type fuel were measured by 46.6 mm/s, 376.5 mm/s for the ACE7 and RFA protective grids in order. Peak frequency also had increasing trend with the bundle flow velocity. Measured pressure drops of 16x16 type fuel protective grids were comparatively higher than those of the reference fuel protective grids

  3. 5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F., E-mail: higorfabiano@gmail.com, E-mail: mdora@nuclear.ufmg.br, E-mail: vitors@cdtn.br, E-mail: aacs@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10{sup 4} to 5.4 x 10{sup 4}. This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

  4. 5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

    International Nuclear Information System (INIS)

    Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F.

    2017-01-01

    The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10 4 to 5.4 x 10 4 . This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

  5. Dimensional Changes Following Immediate and Delayed Implant Placement: A Histomorphometric Study in the Canine.

    Science.gov (United States)

    Yi, Hee-Yong; Park, Young-Seok; Pippenger, Benjamin E; Lee, Bongho; Miron, Richard J; Dard, Michel

    The placement of immediate implants has become a routine treatment modality for the replacement of missing teeth. The aim of the present study was to evaluate dimensional changes of hard tissues following tooth extraction, implant bed preparation, and the subsequent integration of titanium implants placed immediately or following an 8-week healing period. All mandibular premolars were extracted and used as experimental sites in five beagle dogs. The left quadrant was used to compare the healing of alveolar bone following regular tooth extraction or surgical implant bed preparation. The right quadrant was used to compare immediate with delayed implant placement (3.3 mm, Bone Level SLActive, Roxolid, Straumann) after an 8-week healing period. All samples were assessed histologically for new bone area/total area (BATA), bone-to-implant contact (BIC), and bone height changes from the buccal and lingual midlines. Implant bed preparation led to significantly lower BATA values and bone height loss compared with regular extraction sockets (-2.46 mm vs -1.44 mm, respectively; P = .0007). Placement of immediate implants demonstrated buccal and lingual bone height loss of 1.51 mm and 0.91 mm, respectively, whereas only 0.12 mm and 0.12 mm of bone height loss was observed during delayed implant placement. A significantly higher BIC was observed for implants placed immediately compared with delayed placement (52% vs 35%, P Implant bed preparation further increased dimensional changes when compared with routine extraction sockets. Although immediate implant placement produced better BIC than did delayed placement, a significantly higher bone height loss at both the buccal and lingual midlines was reported. Further investigation is underway to minimize dimensional changes following immediate implant placement.

  6. SURGICAL NUTRITION

    Directory of Open Access Journals (Sweden)

    Danny Kurniawan Darianto

    2015-07-01

    Full Text Available A patient undergoing surgery faces great physiologic and psychologic stress. so nutritional demands are greatly increased during this period and deficiencies can easily develop. If these deficiencies are allowed to develop and are not in screening, serious malnutrition and clinical problem can occur. Therefore careful attention must be given to a patient's nutritional status in preparation of surgery, as well as to the individual nutritional needs. If these needs are met, complications are less likely developing. Natural resources provide for rapid recovery. Proper nutrition can speed healing in surgical patients with major trauma, severe malnutition, burns, and other severe illnesses. New techniques for tube feeding, intravenous nutrition for patients with serious weight loss due to gastrointestinal disorders, and use of supplements can hasten wound healing and shorten recovery times.

  7. Accuracy of computer-assisted implant placement with insertion templates

    Science.gov (United States)

    Naziri, Eleni; Schramm, Alexander; Wilde, Frank

    2016-01-01

    Objectives: The purpose of this study was to assess the accuracy of computer-assisted implant insertion based on computed tomography and template-guided implant placement. Material and methods: A total of 246 implants were placed with the aid of 3D-based transfer templates in 181 consecutive partially edentulous patients. Five groups were formed on the basis of different implant systems, surgical protocols and guide sleeves. After virtual implant planning with the CoDiagnostiX Software, surgical guides were fabricated in a dental laboratory. After implant insertion, the actual implant position was registered intraoperatively and transferred to a model cast. Deviations between the preoperative plan and postoperative implant position were measured in a follow-up computed tomography of the patient’s model casts and image fusion with the preoperative computed tomography. Results: The median deviation between preoperative plan and postoperative implant position was 1.0 mm at the implant shoulder and 1.4 mm at the implant apex. The median angular deviation was 3.6º. There were significantly smaller angular deviations (P=0.000) and significantly lower deviations at the apex (P=0.008) in implants placed for a single-tooth restoration than in those placed at a free-end dental arch. The location of the implant, whether in the upper or lower jaw, did not significantly affect deviations. Increasing implant length had a significant negative influence on deviations from the planned implant position. There was only one significant difference between two out of the five implant systems used. Conclusion: The data of this clinical study demonstrate the accuracy and predictable implant placement when using laboratory-fabricated surgical guides based on computed tomography. PMID:27274440

  8. Bilateral sacroiliac luxation fixation using a single transiliosacral pin: surgical technique and clinical outcomes in eight cats.

    Science.gov (United States)

    Parslow, A; Simpson, D J

    2017-06-01

    A very limited safe anatomical window for transiliosacral implant placement exists in cats (fluoroscopy. The procedure can be performed using surgical tools and inventory readily available in general small animal practices. © 2017 British Small Animal Veterinary Association.

  9. A Novel Surgical Template Design in Staged Dental Implant Rehabilitations

    Directory of Open Access Journals (Sweden)

    Michael Patras

    2012-05-01

    Full Text Available Background: The philosophy of a gradual transition to an implant retained prosthesis in cases of full-mouth or extensive rehabilitation usually involves a staged treatment concept. In this therapeutic approach, the placement of implants may sometimes be divided into phases. During a subsequent surgical phase of treatment, the pre-existing implants can serve as anchors for the surgical template. Those modified surgical templates help in the precise transferring of restorative information into the surgical field and guide the optimal three-dimensional implant positioning. Methods: This article highlights the rationale of implant-retained surgical templates and illustrates them through the presentation of two clinical cases. The templates are duplicates of the provisional restorations and are secured to the existing implants through the utilization of implant mounts. Results: This template design in such staged procedures provided stability in the surgical field and enhanced the accuracy in implant positioning based upon the planned restoration, thus ensuring predictable treatment outcomes.Conclusions: Successful rehabilitation lies in the correct sequence of surgical and prosthetic procedures. Whenever a staged approach of implant placement is planned, the clinician can effectively use the initially placed implants as anchors for the surgical template during the second phase of implant surgery.

  10. A novel surgical template design in staged dental implant rehabilitations.

    Science.gov (United States)

    Patras, Michael; Martin, William; Sykaras, Nikitas

    2012-01-01

    The philosophy of a gradual transition to an implant retained prosthesis in cases of full-mouth or extensive rehabilitation usually involves a staged treatment concept. In this therapeutic approach, the placement of implants may sometimes be divided into phases. During a subsequent surgical phase of treatment, the pre-existing implants can serve as anchors for the surgical template. Those modified surgical templates help in the precise transferring of restorative information into the surgical field and guide the optimal three-dimensional implant positioning. This article highlights the rationale of implant-retained surgical templates and illustrates them through the presentation of two clinical cases. The templates are duplicates of the provisional restorations and are secured to the existing implants through the utilization of implant mounts. This template design in such staged procedures provided stability in the surgical field and enhanced the accuracy in implant positioning based upon the planned restoration, thus ensuring predictable treatment outcomes. Successful rehabilitation lies in the correct sequence of surgical and prosthetic procedures. Whenever a staged approach of implant placement is planned, the clinician can effectively use the initially placed implants as anchors for the surgical template during the second phase of implant surgery.

  11. Determining factors of aerosol deposition for four pMDI-spacer combinations in an infant upper airway model.

    Science.gov (United States)

    Janssens, Hettie M; Krijgsman, Arno; Verbraak, Ton F M; Hop, Wim C J; de Jongste, Johan C; Tiddens, Harm A W M

    2004-01-01

    The aim of this study was to measure and compare the influence of tidal volume (Vt) respiratory rate (RR) and pMDI/spacer combination on aerosol deposition of 4 pMDI/spacer combinations, which are used for infants. An anatomically correct upper airway model of a 9-month-old infant was connected to a breathing simulator. Sinusoidal breathing patterns were simulated with; duty cycle T(i)/T(tot) = 0.42, Vt: 25, 50, 75, 100, 150, 200 ml (RR: 30 breaths/min); and RR: 20, 30, 42, 60, 78 breaths/min (Vt: 100 mL). pMDI/Spacers tested were: budesonide 200 microg/Nebuchamber, fluticasone 125 microg/Babyhaler and both budesonide and fluticasone with Aerochamber. Plastic spacers were detergent coated to reduce electrostatic charge. Spacer-output and lung dose were measured by a filter positioned between spacer and facemask or between model and breathing simulator. Particle size distribution of lung dose was assessed with an impactor during simulated breathing. Spacer-output was significantly positively correlated with Vt for all pMDI/spacers (all R > 0.77, p particles particles in the upper airways. Deposition of particles <2.1 microm is relatively flow independent. When electrostatic charge of spacers is reduced, lung dose is pMDI dependent and spacer independent.

  12. Understanding Successful Sandwich Placements: A Bourdieusian Approach

    Science.gov (United States)

    Clark, Martyn; Zukas, Miriam

    2016-01-01

    Sandwich placements and other integrated work and study schemes are increasingly advocated as a key means by which universities can promote students' employability. However, there is little understanding of how successful placements work in terms of facilitating learning and development. Drawing on three longitudinal case studies of students who…

  13. Clitoral Pain Following Retropubic Midurethral Sling Placement

    Directory of Open Access Journals (Sweden)

    Melanie Christofferson, DO

    2015-12-01

    Conclusion: Clitoral pain symptoms following placement of a retropubic midurethral sling should be evaluated and promptly addressed, given the potential negative impact on the patient's sexual function. Christofferson M, Barnard J, and Montoya TI. Clitoral pain following retropubic midurethral sling placement. Sex Med 2015;3:346–348.

  14. Private Placement Debt Financing for Public Entities

    Science.gov (United States)

    Holman, Lance S.

    2010-01-01

    Private placement financing is a debt or capital lease obligation arranged between a municipality or a 501(c) (3) not-for-profit organization and a single sophisticated institutional investor. The investor can be a bank, insurance company, finance company, hedge fund, or high-net worth individual. Private placement financing is similar to…

  15. 32 CFR 1656.10 - Job placement.

    Science.gov (United States)

    2010-07-01

    ... will be reassigned in accordance with § 1656.12. (c) In making job interview referrals and in making... 32 National Defense 6 2010-07-01 2010-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing...

  16. Predicting the impact of feed spacer modification on biofouling by hydraulic characterization and biofouling studies in membrane fouling simulators

    KAUST Repository

    Siddiqui, Amber

    2016-12-22

    Feed spacers are an essential part of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane modules. Geometric modification of feed spacers is a potential option to reduce the impact of biofouling on the performance of membrane systems. The objective of this study was to evaluate the biofouling potential of two commercially available reference feed spacers and four modified feed spacers. The spacers were compared on hydraulic characterization and in biofouling studies with membrane fouling simulators (MFSs). The virgin feed spacer was characterized hydraulically by their resistance, measured in terms of feed channel pressure drop, performed by operating MFSs at varying feed water flow rates. Short-term (9 days) biofouling studies were carried out with nutrient dosage to the MFS feed water to accelerate the biofouling rate. Long-term (96 days) biofouling studies were done without nutrient dosage to the MFS feed water. Feed channel pressure drop was monitored and accumulation of active biomass was quantified by adenosine tri phosphate (ATP) determination. The six feed spacers were ranked on pressure drop (hydraulic characterization) and on biofouling impact (biofouling studies). Significantly different trends in hydraulic resistance and biofouling impact for the six feed spacers were observed. The same ranking for biofouling impact on the feed spacers was found for the (i) short-term biofouling study with nutrient dosage and the (ii) long-term biofouling study without nutrient dosage. The ranking for hydraulic resistance for six virgin feed spacers differed significantly from the ranking of the biofouling impact, indicating that hydraulic resistance of clean feed spacers does not predict the hydraulic resistance of biofouled feed spacers. Better geometric design of feed spacers can be a suitable approach to minimize impact of biofouling in spiral wound membrane systems.

  17. Zygomatic bone graft for oral-antral communication closure and implant placement.

    Science.gov (United States)

    Peñarrocha-Diago, Miguel; García, Berta; Gomez, Dolores; Balaguer, José

    2007-01-01

    The roots of molar and premolar maxillary teeth are often very close to the floor of the maxillary sinus. As a result, extraction of these teeth can leave an oral-antral communication or lead to a fistula that requires treatment. A woman with an oral-antral communication secondary to extraction of a maxillary molar is presented. The communication was closed by means of a bone graft harvested from the wall of the sinus (zygomatic bone). After 3 months, 2 dental implants were placed, one in the pterygoid area and the other with parasinusal angulation. Rehabilitation followed in the form of a screw-retained, fixed prosthesis 3 months after implant placement. There have been no complications after 1 year of follow-up. This surgical technique allowed closure of an oral-antral communication produced by molar extraction through placement of a zygomatic bone graft and subsequent placement of 2 dental implants.

  18. Artificial Intelligence based technique for BTS placement

    International Nuclear Information System (INIS)

    Alenoghena, C O; Emagbetere, J O; 1 Minna (Nigeria))" data-affiliation=" (Department of Telecommunications Engineering, Federal University of Techn.1 Minna (Nigeria))" >Aibinu, A M

    2013-01-01

    The increase of the base transceiver station (BTS) in most urban areas can be traced to the drive by network providers to meet demand for coverage and capacity. In traditional network planning, the final decision of BTS placement is taken by a team of radio planners, this decision is not fool proof against regulatory requirements. In this paper, an intelligent based algorithm for optimal BTS site placement has been proposed. The proposed technique takes into consideration neighbour and regulation considerations objectively while determining cell site. The application will lead to a quantitatively unbiased evaluated decision making process in BTS placement. An experimental data of a 2km by 3km territory was simulated for testing the new algorithm, results obtained show a 100% performance of the neighbour constrained algorithm in BTS placement optimization. Results on the application of GA with neighbourhood constraint indicate that the choices of location can be unbiased and optimization of facility placement for network design can be carried out

  19. Genetic Algorithm Approaches for Actuator Placement

    Science.gov (United States)

    Crossley, William A.

    2000-01-01

    This research investigated genetic algorithm approaches for smart actuator placement to provide aircraft maneuverability without requiring hinged flaps or other control surfaces. The effort supported goals of the Multidisciplinary Design Optimization focus efforts in NASA's Aircraft au program. This work helped to properly identify various aspects of the genetic algorithm operators and parameters that allow for placement of discrete control actuators/effectors. An improved problem definition, including better definition of the objective function and constraints, resulted from this research effort. The work conducted for this research used a geometrically simple wing model; however, an increasing number of potential actuator placement locations were incorporated to illustrate the ability of the GA to determine promising actuator placement arrangements. This effort's major result is a useful genetic algorithm-based approach to assist in the discrete actuator/effector placement problem.

  20. Posterior Cervical Transfacet Fusion with Facetal Spacer for the Treatment of Single-Level Cervical Radiculopathy: A Randomized, Controlled Prospective Study.

    Science.gov (United States)

    Lenzi, Jacopo; Nardone, Antonio; Passacantilli, Emiliano; Caporlingua, Alessandro; Lapadula, Gennaro; Caporlingua, Federico

    2017-04-01

    Single-level cervical radiculopathy may be treated conservatively with cervical tractions. Posterior cervical transfacet fusion with a facetal spacer is a viable option. The aim of the present study is to compare posterior cervical transfacet fusion with conservative physical treatment in single-level cervical radiculopathy. A total of 80 patients were randomized in 2 groups, a surgical group in which patients were given posterior cervical transfacet fusion and a traction group in which patients were treated conservatively with mechanical cervical tractions. Visual analog scale for arm and neck, Neck Disability Index, and Short Form-36 (SF-36) questionnaires were administered preoperatively and after treatment up to 12 months. After treatment, visual analog scale arm scores were greater in traction group (4.7 vs. 1.5 the day after treatment) and at follow-up controls (traction group vs. surgical group: 5.3 vs. 0.6 at 1 month, 3.6 vs. 0.3 at 6 months, 1.8 vs. 0.2 at 12 months). Neck Disability Index scores were lower in the surgical group (surgical group vs. traction group: 4.4 vs. 20.3 at 1 month, 1.3 vs. 10.5 at 6 months). SF-36 scores were greater in the surgical group (surgical group vs. traction group: 96 vs. 70 at 1 month, 96.5 vs. 82.6 at 6 months). Neck disability index and SF-36 scores were superimposable between the groups at 12-month follow-up. No adjacent-segment arthrosis or late complications were reported at 1-year follow-up in the surgical group. posterior cervical transfacet fusion is a safe and effective procedure to treat single-level cervical radiculopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A functional analysis of the spacer of V(DJ recombination signal sequences.

    Directory of Open Access Journals (Sweden)

    Alfred Ian Lee

    2003-10-01

    Full Text Available During lymphocyte development, V(DJ recombination assembles antigen receptor genes from component V, D, and J gene segments. These gene segments are flanked by a recombination signal sequence (RSS, which serves as the binding site for the recombination machinery. The murine Jbeta2.6 gene segment is a recombinationally inactive pseudogene, but examination of its RSS reveals no obvious reason for its failure to recombine. Mutagenesis of the Jbeta2.6 RSS demonstrates that the sequences of the heptamer, nonamer, and spacer are all important. Strikingly, changes solely in the spacer sequence can result in dramatic differences in the level of recombination. The subsequent analysis of a library of more than 4,000 spacer variants revealed that spacer residues of particular functional importance are correlated with their degree of conservation. Biochemical assays indicate distinct cooperation between the spacer and heptamer/nonamer along each step of the reaction pathway. The results suggest that the spacer serves not only to ensure the appropriate distance between the heptamer and nonamer but also regulates RSS activity by providing additional RAG:RSS interaction surfaces. We conclude that while RSSs are defined by a "digital" requirement for absolutely conserved nucleotides, the quality of RSS function is determined in an "analog" manner by numerous complex interactions between the RAG proteins and the less-well conserved nucleotides in the heptamer, the nonamer, and, importantly, the spacer. Those modulatory effects are accurately predicted by a new computational algorithm for "RSS information content." The interplay between such binary and multiplicative modes of interactions provides a general model for analyzing protein-DNA interactions in various biological systems.

  2. Experimental investigations of turbulent flows in rod bundles with and without spacer grids

    International Nuclear Information System (INIS)

    Trippe, G.

    1979-07-01

    In the thermofluiddynamic design of liquid metal cooled reactor fuel elements the lack of experimentally confirmed knowledge of the three-dimensional flow events in rod bundles provided with spacer grids has appeared as a significant problem. To close this gap of knowledge, detailed measurements of the local velocities were made on a 19-rod bundle model. The Pitot method of differential pressure measurements was used as the measuring system. In the first part of the work the fully developed flow regime not influenced by spacers was investigated. A simple relation was derived for distributing the mass flow among the subchannels of a rod bundle; it is but slightly dependent on the Reynolds number. This relation allows a quick, coarse calculation of the distribution of the undisturbed, fully developed mass flow in bundles with similar geometries. By evaluation of further experiments known from the literature, empirical relationships were found for the local velocity distribution within the subchannels of such bundles. In the second part the effect of grid shaped spacers was investigated. The three-dimensional flow events caused by the spacers were completely recorded and interpreted physically. The deeper understanding of these flow processes can now serve to improve the model concept used in the present design computer programs. Single results of the investigations which take primary importance are the quantitative relations existing between the changes of mass flow in the bundle boundary zone, caused by a spacer, and the geometry of this spacer. The transferability to other bundle geometries was discussed and delimited. Moreover, it was shown that the mass flow in the bundle boundary zone can be successively reduced by spacers placed one behind the other in the bundle. A noticeable dependence of flow events on the Reynolds number was not found for the range relevant in practical application (30.000 [de

  3. Immediate placement of implants into infected sites: a systematic review.

    Science.gov (United States)

    Chrcanovic, Bruno Ramos; Martins, Maximiliano Delany; Wennerberg, Ann

    2015-01-01

    Traditionally, before placing dental implants, the compromised teeth are removed and the extraction sockets are left to heal for several months. To preserve the alveolar bone level from the collapse caused by healing and to reduce treatment time in situations in which tooth extraction precedes implant placement, some clinicians began to install the implant immediately into the postextraction socket without waiting for the site to heal. The purpose of this study was to review the literature regarding treatment outcomes of immediate implant placement into sites exhibiting pathology after clinical procedures to perform the decontamination of the implant's site. The following questions were raised: Does the presence of periodontal or endodontic infection affect immediate implant placement success? What is suggested to address the infection in the socket prior to immediate placement? An electronic search in PubMed (U.S. National Library of Medicine, Bethesda, MD, USA) was undertaken in March 2013. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included both animal and human studies, and excluded any review and case reports articles. The publication's intervention had to have been implant placement into a site classified as having an infection (periapical, endodontic, perioendodontic, and periodontal). The search strategy initially yielded 706 references. Thirty-two studies were identified within the selection criteria, from which nine were case reports and review articles and were excluded. Additional hand-searching of the reference lists of selected studies yielded five additional papers. The high survival rate obtained in several studies supports the hypothesis that implants may be successfully osseointegrated when placed immediately after extraction of teeth presenting endodontic and periodontal lesions, provided that appropriate clinical procedures are performed before the implant

  4. AICRG, Part V: Factors influencing implant stability at placement and their influence on survival of Ankylos implants.

    Science.gov (United States)

    Morris, Harold F; Ochi, Shigeru; Orenstein, Ira H; Petrazzuolo, Vincent

    2004-01-01

    Several factors influence primary stabilization of dental implants at placement surgery. These include implant design, bone quality, implant jaw location, and the use of a bone tap. This report evaluates clinical data gathered by the Ankylos Implant Clinical Research Group (AICRG) to assess (1) the influence of several variables on primary stability and (2) the potential for an Ankylos implant (Friadent GmbH, Mannheim, Germany) that is mobile at placement to integrate and survive for at least 3 years of clinical function. The Ankylos implant is a roughened grade-2 titanium screw. A total of 1554 implants were placed in 478 patients. At both the time of placement and abutment connection, the implants were tested for evidence of clinical mobility by attempting to rotate or move the implant with an application of force. Survival was recorded from placement and up to 36 months following placement. At placement, 2.8% were found to be mobile. In the maxillary posterior quadrant, 6.3% were clinically mobile. Implant mobility was frequent (12.2%) in jaw regions with poor-quality bone (BQ-4) or with short implants (8 mm = 8.3% mobile). Of the implants mobile at placement, 97.7% were stable at uncovering. The 3-year postplacement survival of initially mobile implants was 84.1% compared with 96.8% for implants not mobile at placement (chi2 test, P = .001). The Ankylos implant predictably promoted primary stability during surgical placement. Poor bone quality, short implants, and maxillary posterior jaw locations were all associated with a slightly higher rate of mobility at placement. Primary implant stability, while highly desirable, is not absolutely necessary for achieving osseointegration of Ankylos

  5. Surgical accuracy of three-dimensional virtual planning

    DEFF Research Database (Denmark)

    Stokbro, Kasper; Aagaard, Esben; Torkov, Peter

    2016-01-01

    This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy...... and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation...

  6. Anesthetic and Airways Management of a Dog with Severe Tracheal Collapse during Intraluminal Stent Placement

    Directory of Open Access Journals (Sweden)

    M. Argano

    2013-01-01

    Full Text Available This case report describes the anesthetic and airways management of a dog affected by 4th degree tracheal collapse and undergoing endoscope-guided intraluminal stent placement. After premedication with acepromazine and butorphanol, general anesthesia was induced with propofol and maintained with intravenous propofol and butorphanol in constant rate infusion. During intraluminal stent placement, oxygen was supplemented by means of a simple and inexpensive handmade device, namely, a ureteral catheter inserted into the trachea and connected to an oxygen source, which allowed for the maintenance of airways’ patency and adequate patient’s oxygenation, without decreasing visibility in the surgical field or interfering with the procedure. The use of the technique described in the present paper was the main determinant of the successful anesthetic management and may be proposed for similar critical cases in which surgical manipulation of the tracheal lumen, which may potentially result in hypoxia by compromising airways patency, is required.

  7. Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Li Xiaoying

    2015-09-01

    Full Text Available This paper introduces a knitting technique for making innovative curved three-dimensional (3D spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns, and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

  8. Delayed ischemic cecal perforation despite optimal decompression after placement of a self-expanding metal stent: report of a case

    DEFF Research Database (Denmark)

    Knop, Filip Krag; Pilsgaard, Bo; Meisner, Søren

    2004-01-01

    Endoscopic deployment of self-expanding metal stents offers an alternative to surgical intervention in rectocolonic obstructions. Reported clinical failures in the literature are all related to the site of stent placement. We report a case of serious intra-abdominal disease after technically and ...

  9. The Interspinous Spacer: A Clinicoanatomical Investigation Using Plastination

    Directory of Open Access Journals (Sweden)

    Thomas Kaulhausen

    2012-01-01

    Full Text Available Purpose. The relatively new and less-invasive therapeutic alternative “interspinous process decompression device (IPD” is expected to result in improved symptoms of neurogenic intermittent claudication (NIC caused by lumbar spinal stenosis. The aim of the study was to analyze IPD position particularly regarding damage originating from surgical implantation. Methods. Anatomic assessments were performed on a fresh human cadaver. For the anatomic examination, the lumbar spine was plastinated after implantation of the IPDs. After radiographic control, serial 4 mm thick sections of the block plastinate were cut in the sagittal (L1–L3 and horizontal (L3–L5 planes. The macroanatomical positioning of the implants was then analyzed. The insertion procedure caused only little injury to osteoligamentous or muscular structures. The supraspinous ligament was completely intact, and the interspinous ligaments were not torn as was initially presupposed. No osseous changes at the spinal processes were apparent. Contact of the IPD with the spinous processes was visible, so that sufficient biomechanical limitation of the spinal extension seems likely. Conclusions. Minimally invasive IPD implantation with accurate positioning in the anterior portion of the interspinous place is possible without severe surgical trauma.

  10. A Study of Neutronics Effects of the Spacer Grids in a Typical PWR via Monte Carlo Calculation

    OpenAIRE

    Xuan Bach Tran; Nam Zin Cho

    2016-01-01

    Spacer grids play an important role in maintaining the proper form of the fuel assembly structure and ensuring the safety of reactor core design. This study applies the Monte Carlo method to the analysis of the neutronics effects of spacer grids in a typical pressurized water reactor (PWR). The core problem used to analyze the neutronics effects of spacer grids is a modified version of Korea Advanced Institute of Science and Technology benchmark problem 1B, based on an Advanced Power Reactor ...

  11. Effect of different commercial feed spacers on biofouling of reverse osmosis membrane systems: A numerical study

    KAUST Repository

    Bucs, Szilard

    2014-06-01

    Feed spacers and hydrodynamics have been found relevant for the impact of biofouling on performance in reverse osmosis (RO) and nanofiltration (NF) membrane systems.The objectives of this study on biofouling development were to determine the impact of (i) linear flow velocity and bacterial cell load, (ii) biomass location and (iii) various feed spacer geometries as applied in practice as well as a modified geometry spacer.A three-dimensional mathematical model for biofouling of feed spacer channels including hydrodynamics, solute mass transport and biofilm formation was developed in COMSOL Multiphysics and MATLAB software.Results of this study indicate that the feed channel pressure drop increase caused by biofilm formation can be reduced by using thicker and/or modified feed spacer geometry and/or a lower flow rate in the feed channel. The increase of feed channel pressure drop by biomass accumulation is shown to be strongly influenced by the location of biomass. Results of numerical simulations are in satisfactory agreement with experimental data, indicating that this micro-scale mechanistic model is representative for practice. The developed model can help to understand better the biofouling process of spiral-wound RO and NF membrane systems and to develop strategies to reduce and control biofouling. © 2013 Elsevier B.V.

  12. Detection and characterization of spacer integration intermediates in type I-E CRISPR-Cas system.

    Science.gov (United States)

    Arslan, Zihni; Hermanns, Veronica; Wurm, Reinhild; Wagner, Rolf; Pul, Ümit

    2014-07-01

    The adaptation against foreign nucleic acids by the CRISPR-Cas system (Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated proteins) depends on the insertion of foreign nucleic acid-derived sequences into the CRISPR array as novel spacers by still unknown mechanism. We identified and characterized in Escherichia coli intermediate states of spacer integration and mapped the integration site at the chromosomal CRISPR array in vivo. The results show that the insertion of new spacers occurs by site-specific nicking at both strands of the leader proximal repeat in a staggered way and is accompanied by joining of the resulting 5'-ends of the repeat strands with the 3'-ends of the incoming spacer. This concerted cleavage-ligation reaction depends on the metal-binding center of Cas1 protein and requires the presence of Cas2. By acquisition assays using plasmid-located CRISPR array with mutated repeat sequences, we demonstrate that the primary sequence of the first repeat is crucial for cleavage of the CRISPR array and the ligation of new spacer DNA. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. Shape optimization of spacer grids / development of a FE model their buckling analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, B. M.; Im, S. Y.; Chang, J. H.; Jang, I. G.; Choi, K. H. [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    2000-04-01

    An optimal design method is adopted for spacer grids. For contact analysis, a typical cell out of repeated pattern in the assembly is modeled. A commercial code, ABAQUS, is used for detailed analysis of frictional contact. For the optimization, design variables are taken from geometric parameters and several objectives are considered. The optimized shapes and resulting performances are discussed and shown satisfactory. This method is illustrated as a good design tool for structures that has complex behavior due to friction and wear. In this study considered is the buckling of spacer grids in the nuclear fuel assembly, which are required to have a sufficient strength against an accident like earthquake. Special attention is given to the modeling of the spot-welding and the constraints between the unit spacers assembled together : it is found that a proper treatment of the constraints is critical for accurate assessment of the buckling behavior including strain localization at the point of spot welding. The buckling strength of the 17 x 17 spacer grid, which is difficult to analyze due to a large number of degrees of freedom, is obtained from analysis for the smaller models 3 x 3, 5 x 5, 7 x 7 and 9 x 9 spacer grids. 9 refs., 36 figs., 8 tabs. (Author)

  14. Fourteen internal transcribed spacers in the circular ribosomal DNA of Euglena gracilis.

    Science.gov (United States)

    Schnare, M N; Cook, J R; Gray, M W

    1990-09-05

    Cytoplasmic ribosomes from Euglena gracilis contain 16 rRNA components. These include the typical 5 S, 5.8 S and 19 S rRNAs that are found in other eukaryotes as well as 13 discrete small RNAs that interact to form the equivalent of eukaryotic 25-28 S rRNA (accompanying paper). We have utilized DNA sequencing techniques to establish that genes for all of these RNAs, with the exception of 5 S rRNA, are encoded by the 11,500 base-pair circular rDNA of E. gracilis. We have determined the relative positions of the coding regions for the 19 S rRNA and the 14 components (including 5.8 S rRNA) of the large subunit rRNA, thereby establishing that the genes for each of these rRNAs are separated by internal transcribed spacers. We conclude that sequences corresponding to these spacers are removed post-transcriptionally from a high molecular weight pre-rRNA, resulting in a multiply fragmented large subunit rRNA. Internal transcribed spacers, in positions analogous to some of these additional Euglena rDNA spacers, have been found in the rDNA of other organisms and organelles. This finding supports the view that at least some internal transcribed spacers may have been present at an early stage in the evolution of rRNA genes.

  15. Air-water flooding in multirod channels: effects of spacer grids and blockages

    International Nuclear Information System (INIS)

    Cha, Jong Hee; Jun, Hyung Gil

    1993-01-01

    This paper presents the experimental results on flooding of countercurrent flow in vertical multirod channels, which consists of falling water film and upward air flow. In particular, the effects of spacer grids, with and without mixing vane, and of blockage in the multirod bundle on the behaviour of flooding were investigated. The 5 x 5 zircaloy tube bundle was used for the test section. The comparison of previous analytical models and empirical correlations with present data on flooding showed that the existing models and correlations predict much higher flooding curves. The spacer grid causes the lower flooding air flow rate to compare with the bare rod bundle. However, the mixing spacer grids need a higher flooding air flow rate for a constant liquid flow rate than the spacer grids without mixing vanes. The bundle containing blockages has the highest flooding air flow rate among the bundles with spacer grids and blokages. Empirical flooding correlations for the three types of test section have been made. (Author)

  16. Simulation study of transfer characteristics for spacer-filled membrane distillation desalination modules

    International Nuclear Information System (INIS)

    Chang, Hsuan; Hsu, Jian-An; Chang, Cheng-Liang; Ho, Chii-Dong; Cheng, Tung-Wen

    2017-01-01

    Highlights: • A 3D CFD model takes in transmembrane heat and mass transfer developed. • DCMD modules using spacer-filled and empty channels for desalination simulated. • Fluid flow, heat transfer and mass transfer profiles revealed. • Correlations of friction factor and Nusselt number developed. - Abstract: Membrane distillation (MD) is an emerging and promising membrane separation process, which can directly utilize renewable thermal energy or low-grade waste heat, for applications in water or wastewater treatment and food industry. However, a major drawback of MD process is its low energy efficiency. Spacer is the most suggested and studied eddy promoter to enhance the heat and mass transfer, which further improves both the separation and the energy utilization performance, of MD processes. This paper presents the results of a 3D computational fluid dynamics (CFD) simulation of DCMD (direct contact membrane distillation) modules using channels with and without spacers for desalination application. The model employs permeable wall boundary condition to take into account the transmembrane heat and mass transfer and simulates the entire module length. The simulation reveals similar fluctuating distributions of temperature polarization coefficient, transmembrane heat and mass fluxes as well as the shear stress on the membrane surface along the entire module length. Correlations have been developed for friction factor and average Nusselt number. These correlations are useful for the analysis and design of DCMD modules. The extent of heat transfer enhancement by spacers depends on the geometry of spacers and the Reynolds number of fluid.

  17. Using cathode spacers to minimize reactor size in air cathode microbial fuel cells

    KAUST Repository

    Yang, Qiao

    2012-04-01

    Scaling up microbial fuel cells (MFCs) will require more compact reactor designs. Spacers can be used to minimize the reactor size without adversely affecting performance. A single 1.5mm expanded plastic spacer (S1.5) produced a maximum power density (973±26mWm -2) that was similar to that of an MFC with the cathode exposed directly to air (no spacer). However, a very thin spacer (1.3mm) reduced power by 33%. Completely covering the air cathode with a solid plate did not eliminate power generation, indicating oxygen leakage into the reactor. The S1.5 spacer slightly increased columbic efficiencies (from 20% to 24%) as a result of reduced oxygen transfer into the system. Based on operating conditions (1000ς, CE=20%), it was estimated that 0.9Lh -1 of air would be needed for 1m 2 of cathode area suggesting active air flow may be needed for larger scale MFCs. © 2012 Elsevier Ltd.

  18. Investigation of bacteremia after separator placement

    Directory of Open Access Journals (Sweden)

    Anjuman Preet Kaur Dua

    2016-01-01

    Full Text Available Background: Simple orthodontic procedure such as separator placement can be associated with the occurrence of transient bacteraemia. Use of clorhexidine before separator placement has been recommended as a measure to decrease the bacteraemia. Aim: The purpose of this study was to detect the presence of transient bacteremia after separator placement following use of 0.2% chlorhexidine gluconate mouthwash. Methodology: The study group consisted of 27 adult patients who reported for orthodontic treatment (18 males and 9 females. The patients were asked to rinse their mouth for 60 sec with 15 mL of 0.2% chlorhexidine gluconate mouthwash before the separator placement. An aseptic technique was used to draw out 5 ml of blood was from either the left or right antecubital fossa immediately before orthodontic separator placement (as control group, and the second 5 ml sample was taken 1–2 min after the placement of separators mesial and distal to all the first molars. All the blood samples were inoculated into culture bottles containing Brain Heart Infusion and incubated aerobically for 7 days. Media used for bacterial growth is chocolate agar and MacConkey agar. Results: From a total of 27 patients and 54 samples, none of the sample was found positive for bacteremia. Conclusion: This study demonstrated that there is no bacteremia after the placement of separators following the use of chlorhexidine mouthwash.

  19. Percutaneous Thrombin Injection to Complete SMA Pseudoaneurysm Exclusion After Failing of Endograft Placement

    International Nuclear Information System (INIS)

    Szopinski, Piotr; Ciostek, Piotr; Pleban, Eliza; Iwanowski, Jaroslaw; Krol, Malgorzata Serafin-; Marianowska, Agnieszka; Noszczyk, Wojciech

    2005-01-01

    Visceral aneurysms are potentially life-threatening vascular lesions. Superior mesenteric artery (SMA) pseudoaneurysms are a rare but well-recognized complication of chronic pancreatitis. Open surgical repair of such an aneurysm, especially in patients after previous surgical treatment, might be dangerous and risky. Stent graft implantation makes SMA pseudoaneurysm exclusion possible and therefore avoids a major abdominal operation. Percutaneous direct thrombin injection is also one of the methods of treating aneurysms in this area. We report a first case of percutaneous ultrasound-guided thrombin injection to complete SMA pseudoaneurysm exclusion after an unsuccessful endograft placement. Six-month follow-up did not demonstrate any signs of aneurysm recurrence

  20. Interventional radiologic placement of tunneled central venous catheters : results and complications in 557 cases

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Kyo; Do, Young Soo; Paik, Chul H. [Samsung Medical Center, Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)] (and others)

    1999-05-01

    To evaluate prospectively the results of interventional radiologic placement of tunneled central venous catheters, and subsequent complications. Between April 1997 and April 1998, a total of 557 tunneled central venous catheters were percutaneously placed in 517 consecutive patients in an interventional radiology suite. The indications were chemotherapy in 533 cases, total parenteral nutrition in 23 and transfusion in one. Complications were evaluated prospectively by means of a chart review, chest radiography, central vein angiography and blood/catheter culture. The technical success rate for tunneled central venous catheter placement was 100% (557/557 cases). The duration of catheter placement ranged from 4 to 356 (mean, 112{+-}4.6) days; Hickman catheters were removed in 252 cases during follow-up. Early complications included 3 cases of pneumothorax(0.5%), 4 cases of local bleeding/hematoma(0.7%), 2 cases of primary malposition(0.4%), and 1 case of catheter leakage(0.2%). Late complications included 42 cases of catheter-related infection(7.5%), 40 cases of venous thrombosis (7.2%), 18 cases of migration (3.2%), 5 cases of catheter / pericatheter of occlusion(0.8%), and 1 case of pseudoaneurysm(0.2%). The infection rate and thrombosis rate per 1000 days were 1.57 and 1.50, respectively. The technical success rate of interventional radiologic placement of tunneled central venous catheters was high. In comparison to conventional surgical placement, it is a more reliable method and leads to fewer complications.

  1. Are success and survival rates of early implant placement higher than immediate implant placement?

    Science.gov (United States)

    Soydan, S S; Cubuk, S; Oguz, Y; Uckan, S

    2013-04-01

    Immediate placement refers to the placement of an implant into a tooth socket at the time of extraction; early placement refers to the placement of an implant after substantial gingival healing, but before any clinically significant bone fill occurs within the socket. This study evaluated the success and survival rates of implants following immediate and early placement. 50 implants were placed in 36 patients. 26 immediate (group I) and 24 early placements (group II) were performed. Pain or tenderness with function, mobility, radiographic bone loss from initial surgery and exudate history were evaluated. Mean vertical bone loss in the immediate placement group was 0.55 mm and 0.80 mm in the early placement group. The survival rate for the immediate placement group was 96.16% with 51.6 months follow-up and in the early placement group was 100% with 61.9 months follow-up. The results of this study suggest that although the success and survival rates of early placed implants were a little higher and the follow up period was longer than immediately placed implants, the difference was not remarkable. In conclusion, both implant insertion techniques are safe and reliable procedures with considerably high survival rates. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Microbiologic Evaluation of Cotton and Polytetrafluoroethylene (PTFE) Tape as Endodontic Spacer Materials in Primary Molars An in Vivo Study.

    Science.gov (United States)

    Prabhakar, Attiguppe Ramasetty; Dixit, Kratika; Raju, O S

    PTFE tape, which is commonly used as plumber's tape is an inorganic, non-fibrous, ribbon like material. The aim of this study was to evaluate PTFE tape as endodontic spacer material and to compare it with commonly used spacer material that is cotton, in primary teeth. Seventeen children undergoing pulpectomy of lower second primary molar bilaterally were included in the study. Cotton and PTFE tape were placed as spacers on each side randomly. Samples were taken from the access cavity at baseline and after seven days to check for microbial leakage. Spacer materials were also checked for microbial contamination. The results revealed that there was a significant increase in the bacterial colony count after seven days in cotton group. The access cavities were also positive for microbial leakage in the cotton group where the spacers showed positive growth. In PTFE group only two samples showed microbial contamination of spacer and out of two only one sample showed contamination of access cavity along with spacer. Within the limitations of this study, it can be concluded that PTFE tape performed better than cotton as endodontic spacer material. Thus, PTFE tape can be recommended as an endodontic spacer material as an alternative to cotton in primary teeth.

  3. Precordial electrode placement in women.

    Science.gov (United States)

    Macfarlane, P W; Colaco, R; Stevens, K; Reay, P; Beckett, C; Aitchison, T

    2003-03-01

    Precordial ECG electrode positioning was standardised in the early 1940s. However, it has been customary for the V 3 to V 6 electrodes to be placed under the left breast in women rather than in the correct anatomical positions relating to the 4th and 5th interspaces. For this reason, a comparison between the two approaches to chest electrode positioning in women was undertaken. In total 84 women were recruited and ECGs recorded with electrodes in the correct anatomical position and also in the more commonly used positions under the breast. As a separate study, 299 healthy women were recruited to study normal limits of leads V 3 to V 6 recorded with electrodes in the correct anatomical positions and compare them with published normal limits with electrodes in the more commonly used locations. It was shown that there was less variability with electrodes in the correct anatomical positions and that there were significant differences between the new limits of normality compared with the old established limits. Expansion of the database and further analysis of the data is required to make a definitive recommendation with respect to precordial electrode placement in women.

  4. Sensor Placement Optimization using Chama

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geotechnology and Engineering Dept.; Nicholson, Bethany L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Discrete Math and Optimization Dept.; Laird, Carl Damon [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Discrete Math and Optimization Dept.

    2017-10-01

    Continuous or regularly scheduled monitoring has the potential to quickly identify changes in the environment. However, even with low - cost sensors, only a limited number of sensors can be deployed. The physical placement of these sensors, along with the sensor technology and operating conditions, can have a large impact on the performance of a monitoring strategy. Chama is an open source Python package which includes mixed - integer, stochastic programming formulations to determine sensor locations and technology that maximize monitoring effectiveness. The methods in Chama are general and can be applied to a wide range of applications. Chama is currently being used to design sensor networks to monitor airborne pollutants and to monitor water quality in water distribution systems. The following documentation includes installation instructions and examples, description of software features, and software license. The software is intended to be used by regulatory agencies, industry, and the research community. It is assumed that the reader is familiar with the Python Programming Language. References are included for addit ional background on software components. Online documentation, hosted at http://chama.readthedocs.io/, will be updated as new features are added. The online version includes API documentation .

  5. Effect of Weld Properties on the Crush Strength of the PWR Spacer Grid

    Directory of Open Access Journals (Sweden)

    Kee-nam Song

    2012-01-01

    Full Text Available Mechanical properties in a weld zone are different from those in the base material because of different microstructures. A spacer grid in PWR fuel is a structural component with an interconnected and welded array of slotted grid straps. Previous research on the strength analyses of the spacer grid was performed using base material properties owing to a lack of mechanical properties in the weld zone. In this study, based on the mechanical properties in the weld zone of the spacer grid recently obtained by an instrumented indentation technique, the strength analyses considering the mechanical properties in the weld zone were performed, and the analysis results were compared with the previous research.

  6. Assessment of cover to reinforcement in slabs using different spacer and tying distances

    Directory of Open Access Journals (Sweden)

    A. P. Maran

    Full Text Available ABSTRACTGiven that the durability of structures is directly related to the thickness of the cover to reinforcement, it is essential to ensure minimum cover is achieved when building a structure. However, studies show that this is not always the case. One of the reasons for the this problem is the lack of indication, in structural projects, of the positioning of spacers. This situation is compounded by the lack of standards and regulations on the use of spacers (i.e. minimum quantities and required layout. This study assesses three different spacer distances and two different tying distances in order to examine the influence of these factors in the cover to reinforcement. To achieve so, three slabs were prepared in situ using different arrangements. After demoulding, cover thickness was determined using a digital covermeter. It was observed that the factors investigated have a significant influence in the final cover.

  7. A high-performance channel engineered charge-plasma-based MOSFET with high-κ spacer

    Science.gov (United States)

    Shan, Chan; Wang, Ying; Luo, Xin; Bao, Meng-tian; Yu, Cheng-hao; Cao, Fei

    2017-12-01

    In this paper, the performance of graded channel double-gate MOSFET (GC-DGFET) that utilizes the charge-plasma concept and a high-κ spacer is investigated through 2-D device simulations. The results demonstrate that GC-DGFET with high-κ spacer can effectively improve the ON-state driving current (ION) and reduce the OFF-leakage current (IOFF). We find that reduction of the initial energy barrier between the source and channel is the origin of this ION enhancement. The reason for the IOFF reduction is identified to be the extension of the effective channel length owing to the fringing field via high-κ spacers. Consequently, these devices offer enhanced performance by reducing the total gate-to-gate capacitance (Cgg) and decreasing the intrinsic delay (τ).

  8. Measurement of droplet dynamics across grid spacer in mist cooling of subchannel of PWR

    International Nuclear Information System (INIS)

    Lee, S.L.; Sheen, H.J.; Cho, S.K.; Issapour, I.

    1984-01-01

    An experiment was conducted of the dynamics and heat transfer of a droplet-vapor mist flow across a test grid spacer in a flow channel of 2 x 2 electrically heated simulation fuel rods. Embedded thermocouples were used to measure the rod cladding temperature and an unshielded Chromel-Alumel thermocouple was transversed in the center of the subchannel to measure the temperature of the water and steam coolant phases at various axial locations. Thermocouples were also embedded in the test grid spacer. Optical measurements of the size and velocity distributions of droplets and the velocity distribution of the superheated steam were made by special laser-Doppler anemometry techniques through quartz glass windows immediately upstream and downstream of the test grid spacer. Experiments over a range of steam and injected water flow rates and rod heat flux have been performed and some representative results and discussions are presented

  9. [Cervical adaptation of complete cast crowns of various metal alloys, with and without die spacers].

    Science.gov (United States)

    Stephano, C B; Roselino, R F; Roselino, R B; Campos, G M

    1989-01-01

    A metallic replica from a dental preparation for crown was used to make 8 class-IV stone dies. The wax patterns for the casting of the crowns were obtained in two conditions: a) from the stone die with no spacer; and b) from the stone die with an acrylic spacer. Thus, 64 metallic crowns were casted, using 4 different alloys: DURACAST (Cu-Al), NICROCAST (Ni-Cr) and DURABOND (Ni-Cr), and gold. The casted crowns were fitted in the metallic replica and measured as to the cervical discrepance of fitting. The results showed that the use of die spacers decreases the clinical discrepancies of fitting of the casted crowns (in a statistically significant level), no matter the metallic alloy employed.

  10. Temperature dependence of magnetoresistive properties in bottom spin valve films employing very thin Cu spacers

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Soonchul [School of Electronic Engineering, Soongsil University, Seoul 156-743 (Korea, Republic of)]. E-mail: jschul@ssu.ac.kr; Seigler, Michael A. [Seagate Research, Pittsburgh, PA 15222 (United States)

    2007-09-15

    Temperature dependence of magnetoresistive properties in bottom spin valve films having very thin Cu spacers are reported. NiFeCr55 A/NiFe10 A/IrMn70 A/CoFetA/Ru4 A/CoFe(t+3)A/Cu/CoFe tA/NiFe10 A/Ta50 A bottom spin valve films were deposited using a DC magnetron sputter deposition system. Magnetoresistance (MR) ratio reached a maximum of 13.5% and 11.9% at the Cu thickness of 10.4 A, when the thickness of the CoFe layers t was 20 and 10 A, respectively. Unlike the top spin valves reported earlier, the dip in the MR ratio was not observed when the interlayer coupling between the free layer and reference layer became zero. Sheet resistance change (DR{sub s}) reached a maximum of 4.22 {omega}/{open_square} at the Cu spacer thickness of 10 A when the CoFe thickness t was 10 A. Temperature dependences of MR ratio, DR{sub s}, interlayer coupling field (H {sub i}), and sensitivity showed mostly monotonic decrease as the temperature was increased up to 200 deg. C. It turns out that DR{sub s} for the film having 10.4 A of Cu spacer thickness at 200 deg. C was larger than the DR{sub s} for the film having 20 A of Cu spacer thickness at 40 deg. C. This suggests a high output voltage of the spin valve sensor made of the thin Cu spacer even at high operating temperature. These very thin Cu spacers could be utilized for very small devices where the interlayer coupling field is dominated by high demagnetizing fields.

  11. Allergy to pacemaker silicone compounds: recognition and surgical management.

    Science.gov (United States)

    Oprea, Mihaela L; Schnöring, Heike; Sachweh, Jörg S; Ott, Hagen; Biertz, Julia; Vazquez-Jimenez, Jaime F

    2009-04-01

    Silicone is a widely used biomaterial. Contact allergy, particularly to silicone components of pacemaker coatings, is uncommon. We present a 12-year-old girl with a history of complex congenital heart disease and acquired complete heart block excluding transvenous lead placement. Contact allergy to silicone led to multiple surgical interventions until the etiology for recurrent pacemaker wound complications was discovered. The key to diagnosis was a specific manufacturer's patch test. Complete removal of the former pacing system and placement of custom-made silicone free pacemaker components and epicardial use of silicone free transvenous leads were essential for successful therapy.

  12. Selective Placement Program Coordinator (SPPC) Directory

    Data.gov (United States)

    Office of Personnel Management — List of the Selective Placement Program Coordinators (SPPC) in Federal agencies, updated as needed. Users can filter the list by choosing a state and/or agency name.

  13. Spacer stitching’, an innovative material feeding technology for improved thermal resistance

    Science.gov (United States)

    Saeed, H.; Rödel, H.; Krzywinski, S.; Hes, L.

    2017-10-01

    This paper investigates the problems associated with heat loss occurring at the points of needle insertion. The insulation material at stitching points is compressed by sewing thread tensions and consequently the air entrapped is forced to leave its structure. It results in poor thermal insulation at the points of needle insertions. An innovative material feeding technology, ‘Spacer stitching’ is developed which addresses the state of the art of cold spots with a simpler and much efficient method. A comparison of sewing samples of conventional sewing technology with the spacer stitching is carried out in this research paper to study the improvement in thermal properties.

  14. Automatic actuation of a dry powder inhaler into a nonelectrostatic spacer

    DEFF Research Database (Denmark)

    Bisgaard, H

    1998-01-01

    This article describes a new "automatic spacer" device, which has been developed to improve the delivery of inhaled medication to young children. In the device, a dry powder inhaler (DPI) is mechanically actuated into a nonelectrostatic spacer, producing an aerosol cloud of fine drug particles (a...... of the actuation (relative standard deviation, 12%), and a prolonged residence time of the fine particle aerosol (half-life of the fallout of the fine particles, 82 s). These features should prove advantageous in the treatment of young children with inhaled medication....

  15. Microbial fuel cells with an integrated spacer and separate anode and cathode modules

    KAUST Repository

    He, Weihua

    2016-01-01

    A new type of scalable MFC was developed based on using alternating graphite fiber brush array anode modules and dual cathode modules in order to simplify construction, operation, and maintenance of the electrodes. The modular MFC design was tested with a single (two-sided) cathode module with a specific surface area of 29 m2 m−3 based on a total liquid volume (1.4 L; 20 m2 m−3 using the total reactor volume of 2 L), and two brush anode modules. Three different types of spacers were used in the cathode module to provide structural stability, and enhance air flow relative to previous cassette (combined anode–cathode) designs: a low-profile wire spacer; a rigid polycarbonate column spacer; and a flexible plastic mesh spacer. The best performance was obtained using the wire spacer that produced a maximum power density of 1100 ± 10 mW m−2 of cathode (32 ± 0.3 W m−3 based on liquid volume) with an acetate-amended wastewater (COD = 1010 ± 30 mg L−1), compared to 1010 ± 10 mW m−2 for the column and 650 ± 20 mW m−2 for the mesh spacers. Anode potentials were unaffected by the different types of spacers. Raw domestic wastewater produced a maximum of 400 ± 8 mW m−2 under fed batch conditions (wire-spacers), which is one of the highest power densities for this fuel. Over time the maximum power was reduced to 300 ± 10 mW m−2 and 275 ± 7 mW m−2 for the two anode compartments, with only slightly less power of 250 ± 20 mW m−2 obtained under continuous flow conditions. In fixed-resistance tests, the average COD removal was 57 ± 5% at a hydraulic retention time of 8 h. These results show that this modular MFC design can both simplify reactor construction and enable relatively high power generation from even relatively dilute wastewater.

  16. Heterogeneous Diversity of Spacers within CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)

    Science.gov (United States)

    He, Jiankui; Deem, Michael W.

    2010-09-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) in bacterial and archaeal DNA have recently been shown to be a new type of antiviral immune system in these organisms. We here study the diversity of spacers in CRISPR under selective pressure. We propose a population dynamics model that explains the biological observation that the leader-proximal end of CRISPR is more diversified and the leader-distal end of CRISPR is more conserved. This result is shown to be in agreement with recent experiments. Our results show that the CRISPR spacer structure is influenced by and provides a record of the viral challenges that bacteria face.

  17. Self-structuring of lamellar bridged silsesquioxanes with long side spacers.

    Science.gov (United States)

    Fernandes, Mariana; Nobre, Sónia S; Xu, Qinghong; Carcel, Carole; Cachia, Jean Nicolas; Cattoën, Xavier; Sousa, José M; Ferreira, Rute A S; Carlos, Luís D; Santilli, Celso V; Wong Chi Man, Michel; Bermudez, Verónica de Zea

    2011-09-22

    Diurea cross-linked bridged silsesquioxanes (BSs) C(10)C(n)C(10) derived from organosilane precursors, including decylene chains as side spacers and alkylene chains with variable length as central spacers (EtO)(3)Si-(CH(2))(10)-Y-(CH(2))(n)-Y-(CH(2))(10)-Si(OEt)(3) (n = 7, 9-12; Y = urea group and Et = ethyl), have been synthesized through the combination of self-directed assembly and an acid-catalyzed sol-gel route involving the addition of dimethylsulfoxide (DMSO) and a large excess of water. This new family of hybrids has enabled us to conclude that the length of the side spacers plays a unique role in the structuring of alkylene-based BSs, although their morphology remains unaffected. All the samples adopt a lamellar structure. While the alkylene chains are totally disordered in the case of the C(10)C(7)C(10) sample, a variable proportion of all-trans and gauche conformers exists in the materials with longer central spacers. The highest degree of structuring occurs for n = 9. The inclusion of decylene instead of propylene chains as side spacers leads to the formation of a stronger hydrogen-bonded urea-urea array as evidenced by two dimensional correlation Fourier transform infrared spectroscopic analysis. The emission spectra and emission quantum yields of the C(10)C(n)C(10) materials are similar to those reported for diurea cross-linked alkylene-based BSs incorporating propylene chains as side spacers and prepared under different experimental conditions. The emission of the C(10)C(n)C(10) hybrids is ascribed to the overlap of two distinct components that occur within the urea cross-linkages and within the siliceous nanodomains. Time-resolved photoluminescence spectroscopy has provided evidence that the average distance between the siliceous domains and the urea cross-links is similar in the C(10)C(n)C(10) BSs and in oxyethylene-based hybrid analogues incorporating propylene chains as side spacers (diureasils), an indication that the longer side chains in the

  18. Optimization of base-to-emitter spacer thickness to maximize the frequency response of bipolar transistors

    Science.gov (United States)

    Lee, Wai-Kit; Chan, Alain C. K.; Chan, Mansun

    2005-04-01

    The impacts of base-to-emitter spacer thickness on the unity gain frequency ( fT), base resistance ( rB), base collector capacitance ( CBC) and maximum oscillation frequency ( fmax) of a bipolar junction transistor (BJT) are studied. Using the extracted Y-parameters from a simulated device with structural parameters calibrated to an actual process, the resulting fT and fmax with different spacer thickness is reported. A tradeoff between peak fT and fmax is observed and the process window to obtain high fT and fmax is proposed.

  19. Comparison of velocity and temperature fields for two types of spacers in an annular channel

    Directory of Open Access Journals (Sweden)

    Lávička David

    2012-04-01

    Full Text Available The paper deals with measurement of flow field using a modern laser method (PIV in an annular channel of very small dimension - a fuel cell model. The velocity field was measured in several positions and plains around the spacer. The measurement was extended also to record temperatures by thermocouples soldered into stainless-steel tube wall. The measurement was focused on cooling process of the preheated fuel cell tube model, where the tube was very slowly flooded with water. Main result of the paper is comparison of two spacer's designs with respect to measured velocity and temperature fields.

  20. Disclosing brand placement to young children

    OpenAIRE

    De Pauw, Pieter; Hudders, Liselot; Cauberghe, Veroline; De Kuysscher, Charlotte

    2015-01-01

    Purpose – This article examines whether a television brand placement warning cue can alter young children’s susceptibility for advertising effects (i.e., brand attitude) through activating their advertising literacy. The proposed model also puts forward an important moderating role for children’s skeptical attitude toward the brand placement format. Design/methodology/approach – The data were collected among 63 children between 7 and 9 years old (Mage = 8.49; 51% girls) through a single...

  1. Pregnancy Outcomes After Myomectomy With Polytetrafluoroethylene Placement

    OpenAIRE

    Eaton, Jennifer L.; Milad, Magdy P.

    2014-01-01

    Background and Objectives: The aim of this study was to report preliminary data on pregnancy outcomes after myomectomy with placement of an expanded polytetrafluoroethylene adhesion barrier membrane. Methods: In this retrospective case series, 68 women who underwent myomectomy with expanded polytetrafluoroethylene membrane placement between January 1, 2003, and December 31, 2009, were identified. Of these women, 15 subsequently had documented pregnancies and were included in the final dataset...

  2. Règlement institutionnel Déplacements

    International Development Research Centre (IDRC) Digital Library (Canada)

    Julie Pépin

    placements et toutes les réservations connexes conformément au présent règlement. Toutes les personnes qui voyagent pour le Centre doivent avoir recours aux services de cette agence pour l'obtention de conseils, de réservations et de titres de transport aux fins de tous les déplacements payés par le CRDI (transport ...

  3. Multiple immediate implants placement with immediate loading

    OpenAIRE

    Narang, Sumit; Narang, Anu; Jain, Kapil; Bhatia, Vineet

    2014-01-01

    The replacement of missing teeth with implant-borne restorations has become a treatment modality accepted by the scientific community for fully and partially edentulous patients. Recent reports have demonstrated the successful placement of dental implants into the fresh extraction socket in the anterior as well as in molar regions, which is made possible due to modification in implant surface. The present case report highlights the placement of three bicortical screw (BCS) implants into the f...

  4. Hole-transfer induced energy transfer in perylene diimide dyads with a donor-spacer-acceptor motif.

    Science.gov (United States)

    Kölle, Patrick; Pugliesi, Igor; Langhals, Heinz; Wilcken, Roland; Esterbauer, Andreas J; de Vivie-Riedle, Regina; Riedle, Eberhard

    2015-10-14

    We investigate the photoinduced dynamics of perylene diimide dyads based on a donor-spacer-acceptor motif with polyyne spacers of varying length by pump-probe spectroscopy, time resolved fluorescence, chemical variation and quantum chemistry. While the dyads with pyridine based polyyne spacers undergo energy transfer with near-unity quantum efficiency, in the dyads with phenyl based polyyne spacers the energy transfer efficiency drops below 50%. This suggests the presence of a competing electron transfer process from the spacer to the energy donor as the excitation sink. Transient absorption spectra, however, reveal that the spacer actually mediates the energy transfer dynamics. The ground state bleach features of the polyyne spacers appear due to the electron transfer decay with the same time constant present in the rise of the ground state bleach and stimulated emission of the perylene energy acceptor. Although the electron transfer process initially quenches the fluorescence of the donor it does not inhibit energy transfer to the perylene energy acceptor. The transient signatures reveal that electron and energy transfer processes are sequential and indicate that the donor-spacer electron transfer state itself is responsible for the energy transfer. Through the introduction of a Dexter blocker unit into the spacer we can clearly exclude any through bond Dexter-type energy transfer. Ab initio calculations on the donor-spacer and the donor-spacer-acceptor systems reveal the existence of a bright charge transfer state that is close in energy to the locally excited state of the acceptor. Multipole-multipole interactions between the bright charge transfer state and the acceptor state enable the energy transfer. We term this mechanism coupled hole-transfer FRET. These dyads represent a first example that shows how electron transfer can be connected to energy transfer for use in novel photovoltaic and optoelectronic devices.

  5. The Placement History Chart: A Tool for Understanding the Longitudinal Pattern of Foster Children's Placements.

    Science.gov (United States)

    Kim, Hyoun K; Pears, Katherine C; Fisher, Philip A

    2012-08-01

    Despite growing concerns about foster placement instability, little information is available regarding the longitudinal patterns of placement histories among foster children. The purpose of the present study was to develop a charting system using child welfare records to facilitate a better understanding of longitudinal patterns of placement history for 117 foster children. The resulting Placement History Chart included all placements that occurred during the observed time period and accounted for various dimensions: number, length, type, and sequence of placements; timing of transitions; and total time in out-of-home care. The Placement History Chart is an effective tool for placing foster care experiences within a broader developmental context. As such, the Placement History Chart can be a valuable research tool for understanding various dimensions and variations of placement transitions among foster children by capturing sequences and cumulative risks over time. Furthermore, this chart can facilitate the development of intervention programs that are developmentally sensitive and effectively address particularly vulnerable subpopulations of foster children.

  6. Novel anthracycline-spacer-beta-glucuronide, -beta-glucoside, and -beta-galactoside prodrugs for application in selective chemotherapy

    NARCIS (Netherlands)

    Leenders, RGG; Damen, EWP; Bijsterveld, EJA; Scheeren, HW; Houba, PHJ; van der Meulen-Muileman, IH; Boven, E; Haisma, HJ

    A series of anthracycline prodrugs containing an immolative spacer was synthesized for application in selective chemotherapy. The prodrugs having the general structure anthracycline-spacer-beta-glycoside were designed to be activated by beta-glucuronidase or beta-galactosidase. Prodrugs with

  7. Interference-driven spacer acquisition is dominant over naive and primed adaptation in a native CRISPR-Cas system

    NARCIS (Netherlands)

    Staals, Raymond H.J.; Jackson, Simon A.; Biswas, Ambarish; Brouns, Stan J.J.; Brown, Chris M.; Fineran, Peter C.

    2016-01-01

    CRISPR-Cas systems provide bacteria with adaptive immunity against foreign nucleic acids by acquiring short, invader-derived sequences called spacers. Here, we use high-throughput sequencing to analyse millions of spacer acquisition events in wild-type populations of Pectobacterium atrosepticum.

  8. A Study of Neutronics Effects of the Spacer Grids in a Typical PWR via Monte Carlo Calculation

    Directory of Open Access Journals (Sweden)

    Xuan Bach Tran

    2016-02-01

    Full Text Available Spacer grids play an important role in maintaining the proper form of the fuel assembly structure and ensuring the safety of reactor core design. This study applies the Monte Carlo method to the analysis of the neutronics effects of spacer grids in a typical pressurized water reactor (PWR. The core problem used to analyze the neutronics effects of spacer grids is a modified version of Korea Advanced Institute of Science and Technology benchmark problem 1B, based on an Advanced Power Reactor 1400 (APR1400 core model. The spacer grids are modeled and added to this test problem in various ways. Then, by running MCNP5 for all cases of spacer grid modeling, some important numerical results, such as the effective multiplication factor, the spatial distributions of neutron flux, and its energy spectrum are obtained. The numerical results of each case of spacer grid modeling are analyzed and compared to assess which type has more advantages in accuracy of numerical results and effectiveness in terms of geometry building. The conclusion is that the most realistic modeling for Monte Carlo calculation is the “volume-preserving” streamlined heterogeneous spacer grids, but the “banded” dissolution spacer grids modeling is a more practical yet accurate model for routine (deterministic analysis.

  9. Unusual low-energy near-infrared bands for ferrocenyl-naphthalimide donor-acceptor dyads with aromatic spacer groups

    DEFF Research Database (Denmark)

    Tagg, Tei; Kjærgaard, Henrik Grum; Lane, Joseph R.

    2015-01-01

    Time-dependent density functional theory (TDDFT) calculations for a series of donor-spacer-acceptor (D-S-A) molecules with phenyl (1), biphenyl (2), and anthryl (3) spacers interpolated between the ferrocenylalkene donor and -C≡C-4-naphthalimido acceptor components predicted the presence of weak,...

  10. Micro-surgical endodontics.

    Science.gov (United States)

    Eliyas, S; Vere, J; Ali, Z; Harris, I

    2014-02-01

    Non-surgical endodontic retreatment is the treatment of choice for endodontically treated teeth with recurrent or residual disease in the majority of cases. In some cases, surgical endodontic treatment is indicated. Successful micro-surgical endodontic treatment depends on the accuracy of diagnosis, appropriate case selection, the quality of the surgical skills, and the application of the most appropriate haemostatic agents and biomaterials. This article describes the armamentarium and technical procedures involved in performing micro-surgical endodontics to a high standard.

  11. Immediate implant placement and provisionalization in edentulous, extraction, and sinus grafted sites.

    Science.gov (United States)

    Petrungaro, Paul S

    2003-02-01

    The incorporation of restorative procedures during implant placement, as well as during the creation of natural emergence profiles and lifelike ceramic restorations, has become the focus of implantology over the last few years. Recent publications have provided guidelines for success with the immediate restoration procedure and have presented basic surgical protocols for the implant team. Enhancement of the healing phase through the local delivery of growth factors to the surgical site, as well as through advancements in bone grafting materials, has allowed the implant surgeon to accomplish multiple surgical procedures during the initial surgical visit. In addition, advancements in surgical stent designs have allowed the restorative dentist to adequately communicate to the surgeon during surgery the parameters required in the final restoration to replace the natural tooth system with form, function, and esthetics. This article presents the results of more than 400 immediate restored implants placed in edentulous sites, fresh extraction sockets, and sinus grafted sites. Also highlighted are guidelines for surgical success, as well as a description of a surgical stent design that communicates requirements for restorative success to the surgeon, while also serving as an esthetic provisional restoration.

  12. An examination of the influence of spacers on burnout in an annulus cooled by the upflow of Freon-12

    International Nuclear Information System (INIS)

    Ilic, V.

    1975-04-01

    To evaluate the spacer influence on burnout, tests were carried out in Freon-12 at 1.04 MPa (abs.) test section inlet pressure with an internally heated annulus 2743 mm long by 14.4 mm heater diameter, the outer tube (shroud) having a bore of 22.1 mm. The inner rod (heater) was located centrally to the shroud by spacers and their configuration was changed for each test. Comparison of the results with those obtained with a test section having no spacers indicated that spacers can increase burnout power up to 75 per cent, decrease it, or show no effect at all, depending on the combination of the inlet temperature and mass velocity. If the spacers were streamlined, removed from the upstream portion of the heater or relocated farther upstream from the downstream end of the heater, there was a considerably reduced effect on the test section performance. (author)

  13. Plasmin-activated doxorubicin prodrugs containing a spacer reduce tumor growth and angiogenesis without systemic toxicity

    NARCIS (Netherlands)

    Devy, L.; Groot, F.M.H. de; Blacher, S.; Hajitou, A.; Beusker, P.H.; Scheeren, J.W.; Foidart, J.M.; Noel, A.

    2004-01-01

    To generate doxorubicin (Dox) specifically at the tumor site, the chemotherapeutic agent was incorporated into a prodrug by linkage to a peptide specifically recognized by plasmin, which is overproduced in many cancers. ST-9905, which contains an elongated self-elimination spacer, is activated more

  14. Phylogenetic relationships of the genus Phanerochaete inferred from the internal transcribed spacer region

    Science.gov (United States)

    Theodorus H. de Koker; Karen K. Nakasone; Jacques Haarhof; Harold H. Burdsall; Bernard J.H. Janse

    2003-01-01

    Phanerochaete is a genus of resupinate homobasidiomycetes that are saprophytic on woody debris and logs. Morphological studies in the past indicated that Phanerochaete is a heterogeneous assemblage of species. In this study the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA was used to test the monophyly of the genus Phanerochaete and to infer...

  15. Exploring backbone-cation alkyl spacers for multi-cation side chain anion exchange membranes

    Science.gov (United States)

    Zhu, Liang; Yu, Xuedi; Hickner, Michael A.

    2018-01-01

    In order to systematically study how the arrangement of cations on the side chain and length of alkyl spacers between cations impact the performance of multi-cation AEMs for alkaline fuel cells, a series of polyphenylene oxide (PPO)-based AEMs with different cationic side chains were synthesized. This work resulted in samples with two or three cations in a side chain pendant to the PPO backbone. More importantly, the length of the spacer between cations varied from 3 methylene (-CH2-) (C3) groups to 8 methylene (C8) groups. The highest conductivity, up to 99 mS/cm in liquid water at room temperature, was observed for the triple-cation side chain AEM with pentyl (C5) or hexyl (C6) spacers. The multi-cation AEMs were found to have decreased water uptake and ionic conductivity when the spacer chains between cations were lengthened from pentyl (C5) or hexyl (C6) to octyl (C8) linking groups. The triple-cation membranes with pentyl (C5) or hexyl (C6) groups between cations showed greatest stability after immersion in 1 M NaOH at 80 °C for 500 h.

  16. Response of an annular electrostatic probe for a right cylindrical spacer

    DEFF Research Database (Denmark)

    Johansson, Torben; MacAllister, I. W.

    2002-01-01

    The response of an annular electrostatic probe mounted in an electrode is examined with reference to a right cylindrical spacer. The study involves using the probe λ function to derive characteristic parameters. These parameters enable the response of the probe to different charge distributions...

  17. rDNA internal transcribed spacer sequence analysis of Lycoris Hert ...

    African Journals Online (AJOL)

    This paper suggested that the likelihood of hybrid origin of Lycoris species was supported and ITS could be used as a good molecular marker to identify plants of Lycoris. Keywords: Lycoris Hert., internal transcribed spacer (ITS), molecular taxonomy, interspecific relationship. African Journal of Biotechnology Vol. 11(29), pp.

  18. The sequence of spacers between the consensus sequences modulates the strength of procaryotic promoters

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Hammer, Karin

    1998-01-01

    A library of synthetic promoters for Lactococcus lactis was constructed, in which the known consensus sequences were kept constant while the sequences of the separating spacers were randomized. The library consists of 38 promoters which differ in strength from 0.3 relative units, and up to more t......-reactors and cell factories....

  19. Plane wave scattering from a plasmonic nanowire array spacer-separated from a plasmonic film

    Science.gov (United States)

    Thomas, Arun; Trivedi, Rahul; Dhawan, Anuj

    2016-06-01

    In this paper, we present a theoretical analysis of the electromagnetic response of a plasmonic nanowire-spacer-plasmonic film system. The analytical solution presented in this paper is a full-wave solution, which is used to compute the fields scattered by the plasmonic nanostructure system on illumination by a plane electromagnetic wave. The physical structure comprises of an array of plasmonic nanowires made of a plasmonic metal such as gold or silver placed over a plasmonic film of the same material and separated from it by a dielectric spacer such as silica or alumina. Such a nanostructure exhibits a spectrum that is extremely sensitive to various geometric and electromagnetic parameters such as spacer thickness and spacer refractive index, which makes it favourable for various sensing applications such as chemical and biological sensing, strain sensing, position sensing, vibration sensing, and thickness sensing. We report a comparison of our analytical solution with a numerical rigorous coupled wave analysis of the same structure with the plasmonic medium being treated as local in nature.

  20. Recovery of knee mobility after a static or mobile spacer in total knee infection

    NARCIS (Netherlands)

    Brunnekreef, J.J.; Hannink, G.; Mde, W. Malefijt

    2013-01-01

    The purpose of the study was to compare the recovery of knee mobility after two-stage revision of an infected total knee arthroplasty using a static or mobile spacer. At 12 months follow-up, none of the patients had a recurrent infection of their new prosthesis. Knee flexion was lower in the static

  1. Peri-Prosthetic Knee Infection Management: Spacers Loaded with Two or Three Antibiotic Agents.

    Science.gov (United States)

    Ortola, David Joaquin; Fenga, Domenico; Marcellino, Sandra; Rosi, Massimiliano; Centofanti, Francesco; Rosa, Michele Attilio

    2017-07-01

    The purpose of this work was to compare pre-made antibiotic-loaded spacers with two commercially available antibiotic agents and custom-made cements with three antibiotic agents added. We evaluated: (a) the validity of our procedures, (b) the control of the rate of infection in the long term, (c) complications, and (d) quality of life and patient satisfaction. A retrospective cohort study was performed on 112 consecutively treated patients between January 2010 and December 2013; 56 patients were treated with a pre-formed cement spacer (clindamycin + gentamicin), and 56 patients were treated with a spacer loaded with three antibiotic agents (clindamycin + gentamicin + vancomycin). Demographic data were collected: Classification of infection according to criteria of Cierny-Mader; microbiologic results; number of previous operations; and years of disease. Infection control or relapse after at least 18 months of follow-up was evaluated. Complications were recorded. Every patient completed the SF-36 test and Oxford Knee Score. With a follow-up of 32.87 months (standard deviation 12.04), at the end of treatment, amputation occurred in three of 112 patients because of recurrence of infection, and one patient died from other causes not related to the infection. The study population presented a rate of recurrence of infection of 2.70%. Our results suggest that a two stage re-implant with three antibiotic agents added to the spacer should be considered to avoid rescue procedures, especially in patients with multi-resistant micro-organism infections.

  2. Mechanical Properties Of 3D-Structure Composites Based On Warp-Knitted Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Chen Si

    2015-06-01

    Full Text Available In this paper, the mechanical properties (compression and impact behaviours of three-dimension structure (3D-structure composites based on warp-knitted spacer fabrics have been thoroughly investigated. In order to discuss the effect of fabric structural parameters on the mechanical performance of composites, six different types of warp-knitted spacer fabrics having different structural parameters (such as outer layer structure, diameter of spacer yarn, spacer yarn inclination angle and thickness were involved for comparison study. The 3D-structure composites were fabricated based on a flexible polyurethane foam. The produced composites were characterised for compression and impact properties. The findings obtained indicate that the fabric structural parameters have strong influence on the compression and impact responses of 3D-structure composites. Additionally, the impact test carried out on the 3D-structure composites shows that the impact loads do not affect the integrity of composite structure. All the results reveal that the product exhibits promising mechanical performance and its service life can be sustained.

  3. Anomalous DNA binding by E2 regulatory protein driven by spacer sequence TATA.

    Science.gov (United States)

    Xi, Zhiqun; Zhang, Yongli; Hegde, Rashmi S; Shakked, Zippora; Crothers, Donald M

    2010-06-01

    We have investigated the anomalously weak binding of human papillomavirus (HPV) regulatory protein E2 to a DNA target containing the spacer sequence TATA. Experiments in magnesium (Mg(2+)) and calcium (Ca(2+)) ion buffers revealed a marked reduction in cutting by DNase I at the CpG sequence in the protein-binding site 3' to the TATA spacer sequence, Studies of the cation dependence of DNA-E2 affinities showed that upon E2 binding the TATA sequence releases approximately twice as many Mg(2+) ions as the average of the other spacer sequences. Binding experiments for TATA spacer relative to ATAT showed that in potassium ion (K(+)) the E2 affinity of the two sequences is nearly equal, but the relative dissociation constant (K(d)) for TATA increases in the order K(+ )TATA relative to ATAT is independent of ion concentration, whereas for Mg(2+) the affinity for TATA drops sharply as ion concentration increases. Thus, ions of increasing positive charge density increasingly distort the E2 binding site, weakening the affinity for protein. In the case of Mg(2+), additional ions are bound to TATA that require displacement for protein binding. We suggest that the TATA sequence may bias the DNA structure towards a conformation that binds the protein relatively weakly.

  4. The Interspinous Spacer: A New Posterior Dynamic Stabilization Concept for Prevention of Adjacent Segment Disease

    Directory of Open Access Journals (Sweden)

    Antoine Nachanakian

    2013-01-01

    Full Text Available Introduction. Posterior Dynamic stabilization using the interspinous spacer device is a known to be used as an alternative to rigid fusion in neurogenic claudication patients in the absence of macro instability. Actually, it plays an important in the management of adjacent segment disease in previously fused lumbar spine. Materials and Method. We report our experience with posterior dynamic stabilization using an interspinous spacer. 134 cases performed in our institution between September 2008 and August 2012 with different lumbar spine pathologies. The ages of our patients were between 40 and 72 years, with a mean age of 57 years. After almost 4 years of follow up in our patient and comparing their outcome to our previous serious we found that in some case the interspinous distracter has an important role not only in the treatment of adjacent segment disease but also in its prevention. Results and Discussion. Clinical improvement was noted in ISD-treated patients, with high satisfaction rate. At first, radicular pain improves with more than 3/10 reduction of the mean score on visual analog scale (VAS. In addition, disability score as well as disc height and lordotic angle showed major improvement at 3 to 6 months post operatively. And, no adjacent segment disease was reported in the patient operated with interspinous spacer. Conclusion. The interspinous spacer is safe and efficient modality to be used not only as a treatment of adjacent segment disease but also as a preventive measure in patients necessitating rigid fusion.

  5. Silver Nanoparticles Stabilised by Cationic Gemini Surfactants with Variable Spacer Length

    Directory of Open Access Journals (Sweden)

    Martin Pisárčik

    2017-10-01

    Full Text Available The present study is focused on the synthesis and investigation of the physicochemical and biological properties of silver nanoparticles stabilized with a series of cationic gemini surfactants having a polymethylene spacer of variable length. UV-VIS spectroscopy, dynamic light scattering, scanning electron microscopy and zeta potential measurements were applied to provide physicochemical characterization of the silver nanoparticles. The mean size values of the nanoparticles were found to be in the 50 to 115 nm range. From the nanoparticle size distributions and scanning electron microscopy images it results that a population of small nanoparticles with the size of several nanometers was confirmed if the nanoparticles were stabilized with gemini molecules with either a short methylene spacer (two or four −CH2− groups or a long spacer (12 −CH2− groups. The average zeta potential value for silver nanoparticles stabilized with gemini molecules is roughly independent of gemini surfactant spacer length and is approx. +58 mV. An interaction model between silver nanoparticles and gemini molecules which reflects the gained experimental data, is suggested. Microbicidal activity determinations revealed that the silver nanoparticles stabilized with gemini surfactants are more efficient against Gram-negative bacteria and yeasts, which has a direct relation to the interaction mechanism of nanoparticles with the bacterial cell membrane and its structural composition.

  6. Hybrid interventions for catheter placement in pediatric intestinal rehabilitation patients with end-stage venous access.

    Science.gov (United States)

    Sieverding, Ludger; Busch, Andreas; Gesche, Jens; Blumenstock, Gunnar; Sturm, Ekkehard; Tsiflikas, Ilias; Piersma, Femke; Hauser, Anja; Wiegand, Gesa; Hartleif, Steffen; Hofbeck, Michael; Fuchs, Jörg; Warmann, Steven W

    2018-03-01

    The purpose of this study is to analyze the combined approach of endovascular and open surgical procedures for insertion of permanent central venous catheters in children with intestinal failure and end-stage venous access. Data of 14 children (16 interventions) with intestinal failure and end-stage venous access, treated within the pediatric intestinal rehabilitation program at our institution between September 2011 and November 2016, were retrospectively reviewed. The patients underwent hybrid endovascular/open surgical approaches for insertion of central venous catheters. Access to central veins was established through endovascular intervention; catheter placement was achieved with combined interventional and surgical measures depending on the individual vascular conditions. Median age at intervention was 47months (interquartile range (IQR),29-74), median time for interventions was 66min (IQR,42-111). Catheter placement was successfully achieved in all patients. The median dose of irradiation during angiography was 0.2Gy*cm 2 (IQR, 0.2-0.6), no complications occurred during or after interventions. Hybrid endovascular/open surgical procedures can be successfully applied for restoring or maintaining permanent central venous catheters in children with intestinal failure and end-stage venous access. These approaches are a valuable contribution in intestinal rehabilitation programs contributing to a further decrease of the need for intestinal transplantation in affected patients. Treatment Study. Level IV. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Modeling the effect of spacers and biofouling on forward osmosis performance

    KAUST Repository

    Mosqueira Santillán, María José

    2014-11-01

    Currently, the most utilized desalination technology is reverse osmosis (RO), where a membrane is used as a physical barrier to separate the salts from the seawater, using high hydraulic pressure as driving force. A major problem in RO systems is biofouling, caused by severe growth of bacterial biofilms. Both, the need of an external energy input, as well as biofouling, impose a high cost on RO operation. Forward osmosis (FO) is an alternative membrane process that uses an osmotic pressure difference as driving force. FO uses a concentrated draw solution to generate high osmotic pressure, which extracts water across a semi permeable membrane from a feed solution. One of the main advantages of FO is the limited amount of external energy required to extract water from the feed solution. The objective of this research is the assessment of the impact of spacers, separating the membrane sheets, and biofouling on the FO system performance. This type of studies allow the optimization of membrane devices and operational conditions. For this, a two dimensional numerical model for FO systems was developed using computational fluid dynamics (CFD). This model allowed the evaluation of the impact of (i) spacers and (ii) biofilm, and (iii) the combined impact of spacers and biofilm on the performance of FO systems. The results obtained showed that the presence of spacers improved the performance of FO systems. Cavity configuration spacer gave the higher water flux across the membrane in clean systems; whereas for biofouled systems, the submerged configuration showed a better performance. In absence of spacers, the thickness or amount of biofilm is inversely proportional with the water flux. Furthermore, membrane surface coverage of the biofilm is more important than the amount of biofilm in terms of the impact on the performance. The numerical model can be adapted with other parameters (e.g. membrane and spacer thickness, feed and draw solution, solution concentration, etc.) to

  8. How type II CRISPR-Cas establish immunity through Cas1-Cas2-mediated spacer integration.

    Science.gov (United States)

    Xiao, Yibei; Ng, Sherwin; Nam, Ki Hyun; Ke, Ailong

    2017-10-05

    CRISPR (clustered regularly interspaced short palindromic repeats) and the nearby Cas (CRISPR-associated) operon establish an RNA-based adaptive immunity system in prokaryotes. Molecular memory is created when a short foreign DNA-derived prespacer is integrated into the CRISPR array as a new spacer. Whereas the RNA-guided CRISPR interference mechanism varies widely among CRISPR-Cas systems, the spacer integration mechanism is essentially identical. The conserved Cas1 and Cas2 proteins form an integrase complex consisting of two distal Cas1 dimers bridged by a Cas2 dimer. The prespacer is bound by Cas1-Cas2 as a dual-forked DNA, and the terminal 3'-OH of each 3' overhang serves as an attacking nucleophile during integration. The prespacer is preferentially integrated into the leader-proximal region of the CRISPR array, guided by the leader sequence and a pair of inverted repeats inside the CRISPR repeat. Spacer integration in the well-studied Escherichia coli type I-E CRISPR system also relies on the bacterial integration host factor. In type II-A CRISPR, however, Cas1-Cas2 alone integrates spacers efficiently in vitro; other Cas proteins (such as Cas9 and Csn2) have accessory roles in the biogenesis phase of prespacers. Here we present four structural snapshots from the type II-A system of Enterococcus faecalis Cas1 and Cas2 during spacer integration. Enterococcus faecalis Cas1-Cas2 selectively binds to a splayed 30-base-pair prespacer bearing 4-nucleotide 3' overhangs. Three molecular events take place upon encountering a target: first, the Cas1-Cas2-prespacer complex searches for half-sites stochastically, then it preferentially interacts with the leader-side CRISPR repeat, and finally, it catalyses a nucleophilic attack that connects one strand of the leader-proximal repeat to the prespacer 3' overhang. Recognition of the spacer half-site requires DNA bending and leads to full integration. We derive a mechanistic framework to explain the stepwise spacer

  9. Manchester Clinical Placement Index (MCPI): Conditions for medical students’ learning in hospital and community placements

    NARCIS (Netherlands)

    Dornan, Tim; Muijtjens, Arno; Graham, Jennifer; Scherpbier, Albert; Boshuizen, Els

    2012-01-01

    Dornan, T., Muijtjens, A., Graham, J., Scherpbier, A., & Boshuizen, H. P. A. (2012). Manchester Clinical Placement Index (MCPI): Conditions for medical students’ learning in hospital and community placements. Advances in Health Sciences Education, 17, 703-716. doi:10.1007/s10459-10011-19344-x

  10. Barriers and supports to implementation of MDI/spacer use in nine Canadian pediatric emergency departments: a qualitative study

    Directory of Open Access Journals (Sweden)

    Graham Ian D

    2009-10-01

    Full Text Available Abstract Background Despite recent research supporting the use of metered dose inhalers with spacer devices (MDI/spacers in pediatric emergency departments (PEDs for acute exacerbations of asthma, uptake of this practice has been slow. The objectives of this study were to determine the barriers and supports to implementing MDI/spacer research and to identify factors associated with early and late adoption of MDI/spacers in Canadian PEDs. Methods Using a comparative case study design, we classified nine tertiary care pediatric hospital PEDs based on their stage of implementation. Data were collected using focus group interviews with physicians, registered nurses (RNs, and respiratory therapists (RTs, and individual interviews with both patient care and medical directors at each site. Initial coding was based on the Ottawa Model of Research Use (OMRU categories of elements known to influence the uptake of innovations. Results One hundred and fifty healthcare professionals from nine different healthcare institutions participated in this study. Lack of leadership in the form of a research champion, a lack of consensus about the benefits of MDI/spacers among staff, perceived resistance from patients/parents, and perceived increased cost and workload associated with MDI/spacer use were the most prevalent barriers to the adoption of the MDI/spacer. Common strategies used by early-adopting sites included the active participation of all professional groups in the adoption process in addition to a well-planned and executed educational component for staff, patients, and families. Early adopter sites were also more likely to have the MDI/spacer included in a clinical protocol/pathway. Conclusion Potential barriers and supports to implementation have been identified that will help EDs adopt MDI/spacer use. Future interventions intended to increase MDI/spacer use in PEDs will need to be sensitive to the barriers identified in this study.

  11. Shape-memory-alloy-based smart knee spacer for total knee arthroplasty: 3D CAD modelling and a computational study.

    Science.gov (United States)

    Gautam, Arvind; Callejas, Miguel A; Acharyya, Amit; Acharyya, Swati Ghosh

    2018-03-22

    This study introduced a shape memory alloy (SMA)-based smart knee spacer for total knee arthroplasty (TKA). Subsequently, a 3D CAD model of a smart tibial component of TKA was designed in Solidworks software, and verified using a finite element analysis in ANSYS Workbench. The two major properties of the SMA (NiTi), the pseudoelasticity (PE) and shape memory effect (SME), were exploited, modelled, and analysed for a TKA application. The effectiveness of the proposed model was verified in ANSYS Workbench through the finite element analysis (FEA) of the maximum deformation and equivalent (von Mises) stress distribution. The proposed model was also compared with a polymethylmethacrylate (PMMA)-based spacer for the upper portion of the tibial component for three subjects with body mass index (BMI) of 23.88, 31.09, and 38.39. The proposed SMA -based smart knee spacer contained 96.66978% less deformation with a standard deviation of 0.01738 than that of the corresponding PMMA based counterpart for the same load and flexion angle. Based on the maximum deformation analysis, the PMMA-based spacer had 30 times more permanent deformation than that of the proposed SMA-based spacer for the same load and flexion angle. The SME property of the lower portion of the tibial component for fixation of the spacer at its position was verified by an FEA in ANSYS. Wherein, a strain life-based fatigue analysis was performed and tested for the PE and SME built spacers through the FEA. Therefore, the SMA-based smart knee spacer eliminated the drawbacks of the PMMA-based spacer, including spacer fracture, loosening, dislocation, tilting or translation, and knee subluxation. Copyright © 2018. Published by Elsevier Ltd.

  12. Structural equivalence in the transcribed spacers of pre-rRNA transcripts in Schizosaccharomyces pombe.

    Science.gov (United States)

    Lalev, A I; Nazar, R N

    1999-08-01

    The structure of the internal transcribed spacer 2 (ITS2) in Schizosaccharomyces pombe was re-evaluated with respect to phylogenetically conserved features in yeasts, features in other transcribed spacer regions as well as the binding of transacting factors which potentially play a role in ribosomal maturation. Computer analyses and probes for nuclease protection indicate a very simple core structure consisting of a single extended hairpin which includes the interacting termini of the mature 5.8S and 25S rRNAs. Comparisons with ITS2 sequences in greatly diverging organisms indicate that the same feature also can be recognized. This is especially clear in organisms that contain very short sequences in which the putative structures are much less ambiguous. Diversity between organisms is the result of changes in hairpin length as well as the addition of branched helices. Protein binding and gel retardation studies with the S.pombe ITS2 further indicate that, as observed in the 3" external transcribed spacer (ETS) and ITS1 regions, the extended hairpin is not only the site of intermediate RNA cleavage during rRNA processing but also a site for specific interactions with one or more soluble factors. Taken together with other analyses on transcribed spacer regions, the present data suggest that the spacer regions all may act in a similar fashion, not only to organize the maturing terminal sequences, but also serve to organize specific soluble factors possibly acting with snoRNAs or in a manner which is analogous with that of the free snoRNPs.

  13. [Determinants of urgency of nursing home placement].

    Science.gov (United States)

    Kishida, Kensaku; Tanizaki, Shizuko

    2008-05-01

    The aim of this paper was to identify factors affecting the urgency of nursing home placement after introduction of public long-term care insurance. The subjects were families including at least one disabled elderly person and one another family member in two cities in Chugoku Prefecture. The measure of the urgency of placement was 0 if the family did not submit any application for placement, 1 if the care managers judged that the elderly person should enter in the future when she/he really needs placement, 2 if the care managers judged that she/he might be able to wait for a short while, and 3 if the care managers judged that she/he should enter as early as possible. Our estimation method was by ordered logit model. The dependent variable was the measure of the urgency and the independent variables were several attributes of the families. In the estimation, we considered the possibility that the coefficients depend on categories of dependent variable. We obtained data for 146 waiting families and 494 others (total 640). There were differences in the urgency of placement among waiting elderly as follows "she/he should enter as early as possible" (28.8%); "she/he can wait for a while" (32.2%), "she/he should enter in the future when she/he really needs placement" (39.0%). The results of multivariate analyses showed that the urgency of placement correlated significantly with the severity of the elderly persons disabilities, the number of primary caregivers' self-symptoms, the family members' negative attitude toward caregiving, residing in city A, not having one's own house and limited use of short-stay facilities due to the circumstances of the providers. When judging the urgency of placement, we should consider not only whether the applicant has submitted a request for a nursing home or not, but also differences among the waiting families. The urgency of placement correlates significantly with severity of disability of the elderly person, the number of primary

  14. Neoleptonema yongpilii E.-Y. Lee & I.K. Lee, gen. et sp. nov. (Phaeophyceae), based on morphological characters and RuBisCO spacer sequences

    DEFF Research Database (Denmark)

    Lee, E.-Y.; Pedersen, Poul Møller; Lee, I.K.

    2002-01-01

    Elachistaceae, Neoleptonema yongpilii gen. et sp. nov., phylogenetic relationships, plurilocular sporangia, RuBisCO spacer sequences......Elachistaceae, Neoleptonema yongpilii gen. et sp. nov., phylogenetic relationships, plurilocular sporangia, RuBisCO spacer sequences...

  15. Fine Control of Local Whitespace in Placement

    Directory of Open Access Journals (Sweden)

    Jarrod A. Roy

    2008-01-01

    Full Text Available In modern design methodologies, a large fraction of chip area during placement is left unused by standard cells and allocated as “whitespace.” This is done for a variety of reasons including the need for subsequent buffer insertion, as a means to ensure routability, signal integrity, and low coupling capacitance between wires, and to improve yield through DFM optimizations. To this end, layout constraints often require a certain minimum fraction of whitespace in each region of the chip. Our work introduces several techniques for allocation of whitespace in global, detail, and incremental placement. Our experiments show how to efficiently improve wirelength by reallocating whitespace in legal placements at the large scale. Additionally, for the first time in the literature, we empirically demonstrate high-precision control of whitespace in designs with macros and obstacles. Our techniques consistently improve the quality of whitespace allocation of top-down as well as analytical placement methods and achieve low penalties on designs from the ISPD 2006 placement contest with minimal interconnect increase.

  16. Page placement policies for NUMA multiprocessors

    Energy Technology Data Exchange (ETDEWEB)

    LaRowe, R.P. Jr.; Ellis, C.S. (Dept. of Computer Science, Duke Univ., Durham, NC (US))

    1991-02-01

    In many parallel applications, the size of the program's data exceeds even the very large amount of main memory available on large-scale multiprocessors. Virtual memory, in the sense of a transparent management of the main/secondary memory hierarchy, is a natural solution. The replacement, fetch, and placement policies used in uniprocessor paging systems need to be reexamined in light of the differences in the behavior of parallel computations and in the memory architectures of multiprocessors. In this paper the authors investigate the impact of page placement in nonuniform memory access time (NUMA) shared memory MIMD machines. The authors experimentally evaluate several paging algorithms that incorporate different approaches to the placement issue. Under certain workload assumptions, the results show that placement algorithms that are strongly biased toward local frame allocations but are able to borrow remote frames can reduce the number of page faults over strictly local allocation. The increased cost of memory operations due to the extra remote accesses is more than compensated for by the savings resulting from the reduction in demand fetches, effectively reducing the computation completion time for these programs without having adverse effects on the performance of typical NUMA programs. The authors also discuss some early results obtained from an actual kernel implementation of one of the page placement algorithms.

  17. Lateral trap-door window approach with maxillary sinus membrane lifting for dental implant placement in atrophied edentulous alveolar ridge

    Directory of Open Access Journals (Sweden)

    Shou-Yen Kao

    2015-02-01

    Full Text Available One of the most challenging and technically sensitive surgical procedures in conjunction with dental implant rehabilitation is sinus membrane lifting to increase the bone height or volume from the maxillary sinus floor. This important preprosthetic surgical technique has been available for >15 years, making possible the creation of bone volume in the edentulous posterior maxilla for the placement of dental implants in surgically compromised cases. Substantial literature exists regarding the most efficacious way to increase the predictability of this surgical procedure, and reduce its associated complications. In this article, we describe the regional anatomy of the maxillary sinus, the evolution of the sinus membrane lifting procedure, the current surgical technique, its survival rate and associated complications, the need for bone graft or bone substitutes, and current advances in the lateral approach through a trap-door window for sinus membrane lifting for dental implants.

  18. Patterns of major divergence between the internal transcribed spacers of ribosomal DNA in Xenopus borealis and Xenopus laevis, and of minimal divergence within ribosomal coding regions.

    OpenAIRE

    Furlong, J C; Maden, B E

    1983-01-01

    We have determined the nucleotide sequences of the two internal transcribed spacers, the adjacent ribosomal coding sequences and the boundary between the external transcribed spacer and the 18S coding sequence in a cloned ribosomal transcription unit from Xenopus borealis. The transcribed spacers differ very extensively from those of X. laevis. Nevertheless, embedded in the internal transcribed spacers are several short sequence elements which are identical between the two species. These cons...

  19. Surgical handicraft: teaching and learning surgical skills.

    Science.gov (United States)

    Barnes, R W

    1987-05-01

    Surgeons choose their profession with a strong desire to excel at manual therapeutic skills. Although we mime our mentors, we have often received the torch of technique in the absence of a systematic program to optimally develop our manual dexterity. The operating room is the ultimate arena to refine one's technical ability, but a surgical skills laboratory should assume increasing importance in introducing the trainee to the many nuances of the fine manual motor skills necessary for optimal surgical technique. Surgical educators should address the science of surgical handicraft in a manner similar to the science of preoperative and postoperative surgical principles that have been espoused over the past 40 years. Although it has been euphemistically said that "you can teach a monkey to operate," few of us have broken the process down into the basic elements to accomplish such a goal. In view of the increasing complexity of operations and equipment, the constraints on animal laboratories and teaching caseloads, and the mounting economic and medico-legal pressures, the development of optimal surgical skills should be a major objective of every surgical training program. By developing novel programs and scientifically evaluating the results of such endeavors, surgical faculties may find increased academic rewards for being a good teacher.

  20. Fluoroscopic placement of jejunal feeding tubes

    International Nuclear Information System (INIS)

    Hoffer, F.; Mandell, V.S.; Sandler, R.H.; Leichner, A.; Kaplan, L.C.; Haynie, M.

    1992-01-01

    Over a two-and-one-half year period, 50 children underwent placements of jejunal tubes through a nasal route (NJ, n=47) or through an existing gastrostomy site (GJ, n=119). There were four attempted placements (98% success rate). The NJ tubes remained in place an average of 13 days, and the GJ tubes remained in place an average of 37 days. Fluoroscopic time for placement of an NJ tube an averaged 6 min (29 cases) and for a GJ tube 8 minutes (91 cases). In spite of the limited retention time, fluoroscopic time, and availability of alternative methods, fluoroscopically placed jejunal feedings tubes are still playing an active role in this institution. (orig.)

  1. A novel endobronchial approach to massive hemoptysis complicating silicone Y-stent placement for tracheobronchomalacia

    Science.gov (United States)

    Ryu, Changwan; Boffa, Daniel; Bramley, Kyle; Pisani, Margaret; Puchalski, Jonathan

    2018-01-01

    Abstract Rationale: Airway stabilization for severe, symptomatic tracheobronchomalacia (TBM) may be accomplished by silicone Y-stent placement. Common complications of the Y-stent include mucus plugging and granulation tissue formation. Patient concerns: We describe a rare case of massive hemoptysis originating from a silicone Y-stent placed for TBM. Diagnoses: An emergent bronchoscopy showed an actively bleeding, pulsatile vessel at the distal end of the left bronchial limb of the Y-stent. It was felt that the bleeding was caused by, or at least impacted by, the distal left bronchial limb of the Y-stent eroding into the airway wall. Interventions: We hypothesized that placement of oxidized regenerated cellulose (ORC) would provide initial hemostasis, and the subsequent placement of a biocompatible surgical sealant would lead to definitive resolution. Outcomes: ORC provided sufficient hemostasis and the subsequent synthetic polymer reinforced the tissue for complete cessation of the bleed. Lessons: The combined use of ORC and a biocompatible surgical sealant provided long-term management for life-threatening hemoptysis, and potentially morbid procedures such as embolization or surgery were avoided by advanced endobronchial therapy. PMID:29465600

  2. Low-dose acetylsalicylic acid and bleeding risks with ventriculoperitoneal shunt placement.

    Science.gov (United States)

    Kamenova, Maria; Croci, Davide; Guzman, Raphael; Mariani, Luigi; Soleman, Jehuda

    2016-09-01

    OBJECTIVE Ventriculoperitoneal (VP) shunt placement is a common procedure for the treatment of hydrocephalus following diverse neurosurgical conditions. Most of the patients present with other comorbidities and receive antiplatelet therapy, usually acetylsalicylic acid (ASA). Despite its clinical relevance, the perioperative management of these patients has not been sufficiently investigated. The aim of this study was to compare the peri- and postoperative bleeding complication rates associated with ASA intake in patients undergoing VP shunt placement. METHODS Of 172 consecutive patients undergoing VP shunt placement between June 2009 and December 2015, 40 (23.3%) patients were receiving low-dose ASA treatment. The primary outcome measure was bleeding events in ASA users versus nonusers, whereas secondary outcome measures were postoperative cardiovascular events, hematological findings, morbidity, and mortality. A subgroup analysis was conducted in patients who discontinued ASA treatment for < 7 days (n = 4, ASA Group 1) and for ≥ 7 days (n = 36, ASA Group 2). RESULTS No statistically significant difference for bleeding events was observed between ASA users and nonusers (p = 0.30). Cardiovascular complications, surgical morbidity, and mortality did not differ significantly between the groups either. Moreover, there was no association between ASA discontinuation regimens (< 7 days and ≥ 7 days) and hemorrhagic events. CONCLUSIONS Given the lack of guidelines regarding perioperative management of neurosurgical patients with antiplatelet therapy, these findings elucidate one issue, showing comparable bleeding rates in ASA users and nonusers undergoing VP shunt placement.

  3. German causative events with placement verbs

    Directory of Open Access Journals (Sweden)

    De Knop Sabine

    2016-06-01

    Full Text Available Several studies have described the semantic uses of German posture verbs, but only few have dealt with German placement verbs. The present study wants to make up for this gap. Starting from a collection of examples from the core corpora of the Digitales Wörterbuch der Deutschen Sprache (DWDS and some former studies on posture verbs, it first describes the variety of the most common German placement verbs stellen (‘to put upright’, legen (‘to lay down’, setzen (‘to set’ and stecken (‘to stick’.

  4. Multiple immediate implants placement with immediate loading.

    Science.gov (United States)

    Narang, Sumit; Narang, Anu; Jain, Kapil; Bhatia, Vineet

    2014-09-01

    The replacement of missing teeth with implant-borne restorations has become a treatment modality accepted by the scientific community for fully and partially edentulous patients. Recent reports have demonstrated the successful placement of dental implants into the fresh extraction socket in the anterior as well as in molar regions, which is made possible due to modification in implant surface. The present case report highlights the placement of three bicortical screw (BCS) implants into the fresh extraction sockets and one KOS implant in edentulous area with flapless technique. All the implants were immediately loaded and followed up for a period of 6 months.

  5. Multiple immediate implants placement with immediate loading

    Directory of Open Access Journals (Sweden)

    Sumit Narang

    2014-01-01

    Full Text Available The replacement of missing teeth with implant-borne restorations has become a treatment modality accepted by the scientific community for fully and partially edentulous patients. Recent reports have demonstrated the successful placement of dental implants into the fresh extraction socket in the anterior as well as in molar regions, which is made possible due to modification in implant surface. The present case report highlights the placement of three bicortical screw (BCS implants into the fresh extraction sockets and one  KOS implant in edentulous area with flapless technique. All the implants were immediately loaded and followed up for a period of 6 months.

  6. Abortion - surgical - aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000658.htm Abortion - surgical - aftercare To use the sharing features on ... please enable JavaScript. You have had a surgical abortion. This is a procedure that ends pregnancy by ...

  7. Optimizing surgical f

    Directory of Open Access Journals (Sweden)

    Sabry Mohamed Amin

    2016-07-01

    Conclusions: In our study both dexmedetomidine and esmolol were effective in reducing MABP, and lowering the heart rate providing dry surgical field and ensured good surgical condition during cochlear implant surgery in pediatric patients.

  8. American Pediatric Surgical Association

    Science.gov (United States)

    American Pediatric Surgical Association Search for: Login Resources + For Members For Professionals For Training Program Directors For Media For ... Surgical Outcomes Surveys & Results Publications Continuing Education + ExPERT Pediatric Surgery NaT Annual Meeting CME MOC Requirements Residents / ...

  9. Intravenous adenosine for surgical management of penetrating heart wounds.

    Science.gov (United States)

    Kokotsakis, John; Hountis, Panagiotis; Antonopoulos, Nikolaos; Skouteli, Elian; Athanasiou, Thanos; Lioulias, Achilleas

    2007-01-01

    Accurate suturing of penetrating cardiac injuries is difficult. Heart motion, ongoing blood loss, arrhythmias due to heart manipulation, and the near-death condition of the patient can all affect the outcome. Rapid intravenous injection of adenosine induces temporary asystole that enables placement of sutures in a motionless surgical field. Use of this technique improves surgical conditions, and it is faster than other methods. Herein, we describe our experience with the use of intravenous adenosine to successfully treat 3 patients who had penetrating heart wounds.

  10. Finite element modeling of stress distribution in intervertebral spacers of different surface geometries.

    Science.gov (United States)

    Lee, Jae Hyup; Baek, Myong-Hyun; Kim, Young Eun; Seo, Jun-Hyuk; Song, Dong Ryul; Ryu, Hyun-Seung; Lee, Choon-Ki; Chang, Bong-Soon

    2013-11-01

    Intervertebral disc spacers using bioactive ceramics have been used to treat degenerative spinal disease. Tooth-shaped spacers are commonly used to prevent migration, but there is a possibility of fracture when inserted or after insertion. Intervertebral disc spacers with either an isosceles triangle-shaped tooth (T1) or a right triangle-shaped tooth (T2) were used as a control group. The design factors for the experimental group were modified to prevent fractures induced by stress concentration, and the surfaces of the spacers were designed as either an isosceles triangle-shaped valley (V1) or a right triangle-shaped valley (V2). Linear analysis using finite element model (FEM) was performed, and Von Mises stress distribution was calculated by applying 1000 N of uniformly distributed load. Samples of the V2 design were made with bioactive glass-ceramics (BGS-7) and evaluated for compressive strength, fatigue degree, and impact strength. Von Mises stress was highest at the first tooth from the posterior side for the control group and at the center for the experimental group. Compared with the control group, the experimental group showed 18.4% and 82.5% reduction (V1 vs. T1 and V2 vs. T2, respectively) in the maximum stress at the bottom of the valleys. The FEM analysis revealed that the V2 design had the most even load distribution. The V2 samples with bioactive glass-ceramics were evaluated for compressive strength, and all six samples were not fractured up to 24 000 N. However, the average impact strength was 19.42 kN, suggesting that momentary force caused damage at a lower load than compression with a steady speed. The BGS-7 intervertebral disc spacer with V2 design was not fractured during the fatigue test at maximum pressure of 8000 N, R ≥10, 5 Hz, and 5 million cycles. These data confirm that the BGS-7 spacer with the V2 design may be clinically applicable. Collectively, the modified surface geometry of the experimental group significantly lowered Von

  11. Influence of spacer length on heparin coupling efficiency and fibrinogen adsorption of modified titanium surfaces

    Directory of Open Access Journals (Sweden)

    Gbureck Uwe

    2007-07-01

    Full Text Available Abstract Background Chemical bonding of the drug onto surfaces by means of spacer molecules is accompanied with a reduction of the biological activity of the drug due to a constricted mobility since normally only short spacer molecule like aminopropyltrimethoxysilane (APMS are used for drug coupling. This work aimed to study covalent attachment of heparin to titanium(oxide surfaces by varying the length of the silane coupling agent, which should affect the biological potency of the drug due to a higher mobility with longer spacer chains. Methods Covalent attachment of heparin to titanium metal and TiO2 powder was carried out using the coupling agents 3-(Trimethoxysilyl-propylamine (APMS, N- [3-(Trimethoxysilylpropyl]ethylenediamine (Diamino-APMS and N1- [3-(Trimethoxy-silyl-propyl]diethylenetriamine (Triamino-APMS. The amount of bound coupling agent and heparin was quantified photometrically by the ninhydrin reaction and the tolidine-blue test. The biological potency of heparin was determined photometrically by the chromogenic substrate Chromozym TH and fibrinogen adsorption to the modified surfaces was researched using the QCM-D (Quartz Crystal Microbalance with Dissipation Monitoring technique. Results Zeta-potential measurements confirmed the successful coupling reaction; the potential of the unmodified anatase surface (approx. -26 mV shifted into the positive range (> + 40 mV after silanisation. Binding of heparin results in a strongly negatively charged surface with zeta-potentials of approx. -39 mV. The retaining biological activity of heparin was highest for the spacer molecule Triamino-APMS. QCM-D measurements showed a lower viscosity for adsorbed fibrinogen films on heparinised surfaces by means of Triamino-APMS. Conclusion The remaining activity of heparin was found to be highest for the covalent attachment with Triamino-APMS as coupling agent due to the long chain of this spacer molecule and therefore the highest mobility of the drug

  12. An update on implant placement and provisionalization in extraction, edentulous, and sinus-grafted sites. A clinical report on 3200 sites over 8 years.

    Science.gov (United States)

    Petrungaro, Paul S

    2008-06-01

    Provisionalization of dental implants at placement has become more prominent in the field of implantology over the past several years, especially in the esthetic zone. The benefits of this treatment option include immediate tooth replacement, formation and maintenance of esthetic soft-tissue contours, containment for bone-grafting and tissue-regenerative procedures, and an improved sense of the patient's perception of the implant process. The blending together of the surgical and prosthetic/esthetic phase has never been more important as implant systems, abutment options, and surgical techniques have helped optimize procedures that can be accomplished at the surgical visit. This article reviews the guidelines for surgical success first described by the author in 2003 and expands upon those results. This article highlights the results of more than 3200 immediately restored implants placed in edentulous, fresh extraction sockets, and sinus-grafted sites, over an 8-year period, and presents a case for each area of placement.

  13. Mechanical evaluation of hip cement spacer reinforcement with stainless steel Kirschner wires, titanium and carbon rods, and stainless steel mesh.

    Science.gov (United States)

    Kaku, Nobuhiro; Tabata, Tomonori; Tsumura, Hiroshi

    2015-04-01

    In two-stage treatments for infections after total hip arthroplasty, antibiotic-loaded cement spacers help treat the infection by antibiotic elution and prevent contraction. However, such spacers are weak and may fracture while awaiting replacement, impairing functionality. We evaluated whether a Kirschner wire (K-wire) mounted into the spacer reinforced its strength along with the effects of the reinforcing material, position, and intensity. Spacers without reinforcing materials constituted the control group. As reinforcing materials, stainless steel K-wires (diameters 3 and 6 mm), titanium alloy and carbon fibers (diameter 3.175 mm), and stainless steel meshes (inner and outer diameters, 6 and 9 mm, respectively) were inserted into the spacer mold before filling with cement. The spacers complied with ISO 7206-4; a compressive load was applied using a testing machine with a velocity of 25.4 mm/min, and the maximum load was recorded. We used 1-3 K-wires positioned on the medial side, lateral side, neck only, and stem only and tested 3 specimens for each condition. The control group withstood the highest load. Stainless steel was the strongest material; 3-mm K-wires in the neck and lateral side withstood a higher load. The computed tomography (CT) imaging revealed a cavity between the K-wires and cement. When K-wires were inserted along the whole length, despite cement fractures, continuity was maintained because of the reinforcing materials. It is difficult to improve the reinforcing strength of spacers using K-wires; however, K-wires prevented dislocation of cement spacer fragments, which can help prevent contraction and facilitate spacer removal during replacement.

  14. On the Origin of Reverse Transcriptase-Using CRISPR-Cas Systems and Their Hyperdiverse, Enigmatic Spacer Repertoires

    Directory of Open Access Journals (Sweden)

    Sukrit Silas

    2017-07-01

    Full Text Available Cas1 integrase is the key enzyme of the clustered regularly interspaced short palindromic repeat (CRISPR-Cas adaptation module that mediates acquisition of spacers derived from foreign DNA by CRISPR arrays. In diverse bacteria, the cas1 gene is fused (or adjacent to a gene encoding a reverse transcriptase (RT related to group II intron RTs. An RT-Cas1 fusion protein has been recently shown to enable acquisition of CRISPR spacers from RNA. Phylogenetic analysis of the CRISPR-associated RTs demonstrates monophyly of the RT-Cas1 fusion, and coevolution of the RT and Cas1 domains. Nearly all such RTs are present within type III CRISPR-Cas loci, but their phylogeny does not parallel the CRISPR-Cas type classification, indicating that RT-Cas1 is an autonomous functional module that is disseminated by horizontal gene transfer and can function with diverse type III systems. To compare the sequence pools sampled by RT-Cas1-associated and RT-lacking CRISPR-Cas systems, we obtained samples of a commercially grown cyanobacterium—Arthrospira platensis. Sequencing of the CRISPR arrays uncovered a highly diverse population of spacers. Spacer diversity was particularly striking for the RT-Cas1-containing type III-B system, where no saturation was evident even with millions of sequences analyzed. In contrast, analysis of the RT-lacking type III-D system yielded a highly diverse pool but reached a point where fewer novel spacers were recovered as sequencing depth was increased. Matches could be identified for a small fraction of the non-RT-Cas1-associated spacers, and for only a single RT-Cas1-associated spacer. Thus, the principal source(s of the spacers, particularly the hypervariable spacer repertoire of the RT-associated arrays, remains unknown.

  15. Similar Results in Children with Asthma for Steady State Pharmacokinetic Parameters of Ciclesonide Inhaled with or without Spacer

    Directory of Open Access Journals (Sweden)

    H. Boss

    2010-01-01

    Full Text Available Background Ciclesonide is an inhaled corticosteroid administered by a metered dose inhaler (MDI to treat bronchial asthma. After inhalation, the inactive ciclesonide is converted by esterases in the airways to active metabolite desisobutyryl-ciclesonide (des-CIC. Aim To compare the pharmacokinetic (PK parameters of des-CIC in children after administration of therapeutic dose of ciclesonide with and without spacer (AeroChamber Plus™. Methods Open-label, 3 period, cross over, repeated dose, PK study in 37 children with mild to moderate stable asthma (age: 6–11 y; body weight: 20–53 kg. During each 7-day treatment period, ciclesonide was inhaled once in the morning: A 160 μg MDI with spacer, B 80 μg MDI with spacer, and C 160 μg MDI without spacer. Serum PK parameters of ciclesonide and des-CIC were determined on Day 7 of each period. The primary PK parameters were the AUC τ and C max for des-CIC. Results Inhaling ciclesonide with spacer led to a dose proportional systemic exposure (AUC τ of des-CIC (0.316 μg*h/L for 80 μg and 0.663 μg*h/L for 160 μg. The dose-normalized systemic exposure for des-CIC (based on AUC τ was 27% higher after inhalation of ciclesonide 80 μg or 160 μg with spacer than without spacer; the corresponding C max values for des-CIC were, respectively, 63% and 55% higher with spacer. No clinically relevant abnormalities or adverse drug reactions were observed. Conclusions Inhalation of therapeutic ciclesonide dose with spacer led to a slight increase in the systemic exposure of des-CIC, which does not warrant dose adjustment.

  16. A comparative evaluation of application techniques of a paint-on die spacer in grooves: an in vitro study.

    Science.gov (United States)

    Vaishali, K; Prasad, D Krishna; Shetty, Manoj

    2013-12-01

    The use of paint-on die spacer to improve the seating of casting has become quite popular in the recent years. The generally accepted range of paint-on die spacer is approximately 20-40 μm, which suggests a range of tolerance. The painting of the retentive grooves with die spacer has always been a subject of debate. The primary purpose of this study was to determine if there was a tendency for the paint-on die spacer to accumulate in grooves of tooth preparation in sufficient thickness to exceed this accepted range of tolerance when applied using two different techniques. Eight die stone blocks with three grooves each were prepared. Half the samples were painted in unidirectional method and the other halves were painted using the haphazard method of application. The thickness of the die spacer was measured at different positions using 200× magnification and the mean and standard deviations were calculated. On analysis it was seen that the thickness of the paint-on die spacer in grooves was in the range of 20-40 μm for unidirectional method of application, whereas in haphazard method of application the thickness of the paint-on die spacer was in the range of 28-132 μm. From the above study it was concluded that the method of application influenced the thickness of the paint-on die spacer. The recommended thickness of the die spacer was achieved on unidirectional method of application.

  17. Prosthetically directed implant placement using computer software to ensure precise placement and predictable prosthetic outcomes. Part 1: diagnostics, imaging, and collaborative accountability.

    Science.gov (United States)

    Rosenfeld, Alan L; Mandelaris, George A; Tardieu, Philippe B

    2006-06-01

    The need for an accurate diagnosis and treatment plan remains essential for predictable treatment outcomes with dental implants. Advances in computerized tomography (CT) technology now enable the execution of a surgical outcome based on presurgical planning. Precise implant placement no longer relies on socalled mental navigation but rather can be computer guided, based on a three-dimensional, prosthetically directed plan. Current CT technology enables all implant team members to embrace the concept of collaborative accountability, which can ensure consistent outcomes. Clinicians can fabricate an implant-supported prosthesis presurgically using patients' CT scan data. The purpose of this paper is to discuss the use of scanning appliances to transfer clinically relevant prosthetic outcome information to a CT data set. With SimPlant software, this information can be used to provide a pretreatment outcome analysis, which can be used for fabrication of stereolithographic models and surgical drilling guides used during osteotomy preparation.

  18. Tissue modeling following implant placement in fresh extraction sockets.

    Science.gov (United States)

    Araújo, Mauricio G; Sukekava, Flavia; Wennström, Jan L; Lindhe, Jan

    2006-12-01

    To study whether osseointegration once established following implant placement in a fresh extraction socket may be lost as a result of tissue modeling. Seven beagle dogs were used. The third and fourth premolars in both quadrants of the mandible were used as experimental teeth. Buccal and lingual full-thickness flaps were elevated and distal roots were removed. Implants were installed in the fresh extraction socket. Semi-submerged healing of the implant sites was allowed. In five dogs, the experimental procedure was first performed in the right side of the mandible and 2 months later in the left mandible. These five animals were sacrificed 1 month after the final implant installation. In two dogs, the premolar sites on both sides of the mandible were treated in one surgical session and biopsies were obtained immediately after implant placement. All biopsies were processed for ground sectioning and stained. The void that existed between the implant and the socket walls at surgery was filled at 4 weeks with woven bone that made contact with the SLA surface. In this interval, (i) the buccal and lingual bone walls underwent marked surface resorption and (ii) the height of the thin buccal hard tissue wall was reduced. The process of healing continued, and the buccal bone crest shifted further in the apical direction. After 12 weeks, the buccal crest was located>2 mm apical of the marginal border of the SLA surface. The bone-to-implant contact that was established during the early phase of socket healing following implant installation was in part lost when the buccal bone wall underwent continued resorption.

  19. Hard tissue augmentation for alveolar defects before implant placement

    Directory of Open Access Journals (Sweden)

    Mutia Rochmawati

    2017-08-01

    Full Text Available Background. Often when planning implant therapy, there is a need to augment or  replace  bone  that  has  been  lost. The alveolar defects may occur as a result of tooth loss due to extraction, advanced periodontal diseases or trauma, long term use of removable appliances, dehiscence and fenestration defects, developmental defects/clefts, congenitally missing teeth and odontogenic cysts and tumors. Insufficient bone volume can be brought about by hard tissue augmentation. This techniques have led to increased predictability in reconstruction of alveolar ridge defects and functional implant placement. Purpose. To describe the methods of hard tissue augmentation which can be done with block grafts (autografts and allografts, particulate grafts (cortical and cancellous, xenografts, or synthetic materials. Review. The reconstruction of a normal alveolar housing, in height and width, is imperative to achieve a harmonious balance between biology, function, and aesthetics. Depending on the size and morphology of the defect, horizontal or vertical, various augmentation procedures can be used. Soft tissue management is a critical aspect of hard tissue augmentation procedures. Incisions, reflection, and manipulation should be designed to optimize blood supply and wound closure. The design and management of mucoperiosteal flaps must consider the increased dimensions of the ridge after augmentation as well as esthetics and approximation of the wound margins. The surgical procedure needs to be executed with utmost care to preserve the maximum vascularity to the flap and minimize tissue injury. Conclusion. Alveolar ridge defects can be classified by using Seibert’s classification or HVC System. The treatment of alveolar ridge defect before implant placement can be done with hard tissue augmentation.

  20. Predicting success on the Advanced Placement Biology Examination

    Science.gov (United States)

    Shepherd, Lesa Hanlin

    Four hundred sixty students in four public high schools were used as subjects to determine which of eleven academic and demographic factors studied were significant predictors of success for the Advanced Placement Biology Examination. Factors studied were attendance, class rank, gender, grade level at the time of the examination, grade point average, level of prerequisite biology course, number of Advanced Placement Examinations taken in the year prior to the Advanced Placement Biology Examination, number of Advanced Placement Examinations taken in the same year as the Advanced Placement Biology Examination, proposed major in college, race, and SAT mathematics, verbal, and combined score. Significant relationships were found to exist between the Advanced Placement Biology Examination score and attendance, class rank, gender, grade level at the time of the Advanced Placement Biology Examination, grade point average, number of Advanced Placement Examinations taken in the year prior to the Advanced Placement Biology Examination, number of Advanced Placement Examinations taken in the same year as the Advanced Placement Biology Examination, race, and SAT scores. Significant relationships were not found to exist between Advanced Placement Biology Examination score and level prerequisite biology course and Advanced Placement Biology Examination score and proposed major in college. A multiple regression showed the best combination of predictors to be attendance, SAT verbal score, and SAT mathematics score. Discriminant analysis showed the variables in this study to be good predictors of whether the student would pass the Advanced Placement Biology Examination (score a 3, 4, or 5) or fail the Advanced Placement Biology Examination (score a 1 or 2). These results demonstrated that significant predictors for the Advanced Placement Biology Examination do exist and can be used to assist in the prediction of scores, prediction of passing or failing, the identification of

  1. Immediate dental implant placement with immediate loading following extraction of natural teeth.

    Science.gov (United States)

    Singh, Mayank; Kumar, Lakshya; Anwar, Mohd; Chand, Pooran

    2015-01-01

    The loss of tooth in the esthetic area is often a traumatic experience for the patient. Patients may suffer real or perceived detrimental effects following the loss of one or more teeth. Dental implant offers the most cost-effective and long-term solution for replacement of missing teeth with high average life expectancy, providing the patient with the best sense of security and well-being. Recently, immediate implant placement after extraction of tooth with early loading has become more common. The advantages of this procedure include fewer surgical interventions, reduction in overall treatment time, reduced soft and hard tissue loss, and psychological satisfaction to the patient. This case report describes the procedure for immediate implant placement with immediate loading of implants by provisional restorations.

  2. A Novel Technique of Fabricating a Modified Removable Provisional Prosthesis over an Autologous Bone Grafted Maxillary Anterior Edentulous Segment Prior to Implant Placement

    OpenAIRE

    Andonissamy, Leoney; Vidhya, N. Sri

    2017-01-01

    Implant dentistry has provided a lot of surgical as well as prosthetic techniques for improving the success of the implants. The surgical technique commonly followed now prior to implant placement is bone grafting procedure. One of the commonest techniques is the use of autologous block graft harvested from mandibular chin region. However, interference in healing as well as excessive bone resorption due to the use of removable provisional prosthesis over the bone grafted region has been commo...

  3. Source placement for equalization in small enclosures

    DEFF Research Database (Denmark)

    Stefanakis, Nick; Sarris, J.; Cambourakis, G.

    2008-01-01

    ) but not with those that will deteriorate it (the "undesired" modes). Simulation results in rectangular rooms and in a car cavity show the benefits of source placement in terms of reduced overall error and increased spatial robustness in the equalization process. Additional benefits, which can be derived by proper...

  4. Endoscopic stent placement throughout the gastrointestinal tract

    NARCIS (Netherlands)

    van den Berg, M.W.

    2014-01-01

    In this thesis we focussed our research on stent placement throughout the GI tract. In search for ideal stents for treatment of malignant oesophageal stenosis and gastric outlet obstruction we evaluated new stent designs in prospective cohort studies. Smaller research projects mainly aimed to

  5. Simple, quick, and efficient implant placement jig

    Directory of Open Access Journals (Sweden)

    Nikhil Narayan Pai

    2015-01-01

    Full Text Available Implants have become an inherent part of everyday orthodontic practice, but unlike prosthodontic implants, their placement and insertion into narrow interradicular spaces for orthodontic purposes remain a tricky and challenging part to most clinicians. An innovative and clinically useful method has been described here for safe and easy insertion of mini-implants.

  6. Weld Strength Assessment for Tape Placement

    NARCIS (Netherlands)

    Grouve, Wouter Johannes Bernardus; Warnet, Laurent; Akkerman, Remko; Wijskamp, Sebastiaan; Kok, J.S.M.

    2010-01-01

    A mandrel peel set-up is developed to assess the peel fracture toughness of fibre reinforced thermoplastic tapes welded on a woven laminate using a laser-assisted tape placement robot. A comprehensive experimental programme was designed to investigate the influence of nip point temperature and

  7. Suboccipital neuropathy after bone conduction device placement

    NARCIS (Netherlands)

    Faber, H.T.; Ru, J.A. de

    2013-01-01

    OBJECTIVE: To describe the clinical characteristics of a 70-year-old female with occipital neuropathy following bone conduction device surgery. DESCRIPTION: A 65-year-old woman underwent bone conduction device placement surgery on the left temporal bone. Postoperatively she progressively developed

  8. Photoelectron Spectroscopy in Advanced Placement Chemistry

    Science.gov (United States)

    Benigna, James

    2014-01-01

    Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

  9. BIBLIOGRAPHIC GUIDE FOR ADVANCED PLACEMENT, LATIN.

    Science.gov (United States)

    BARRON, ROBERT; ROSELLE, LEONE

    LITERARY AND CRITICAL WORKS, REFERENCE BOOKS, PERIODICALS, RECORDS, FILMS, AND FILMSTRIPS DEALING WITH ROMAN LITERATURE, HISTORY, CIVILIZATION, MYTHOLOGY, AND LANGUAGE ARE INCLUDED IN THIS BIBLIOGRAPHY OF RECOMMENDED READING IN ENGLISH FOR ADVANCED PLACEMENT PROGRAMS IN LATIN. THE LIST IS DIVIDED INTO TWO $500 GROUPS, SO THAT FOR CONVENIENCE IN…

  10. 34 CFR 300.116 - Placements.

    Science.gov (United States)

    2010-07-01

    ... educational placement of a child with a disability, including a preschool child with a disability, each public... with a disability requires some other arrangement, the child is educated in the school that he or she... modifications in the general education curriculum. (Approved by the Office of Management and Budget under...

  11. Realistic Approach for Phasor Measurement Unit Placement

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul

    2015-01-01

    This paper presents a realistic cost-effectivemodel for optimal placement of phasor measurement units (PMUs) for complete observability of a power system considering practical cost implications. The proposed model considers hidden or otherwise unaccounted practical costs involved in PMU installat...

  12. Literary Archetypes. Advanced Placement English Curriculum Guide.

    Science.gov (United States)

    Anne Arundel County Public Schools, Annapolis, MD.

    Providing students with the opportunity to earn college credit while still in high school, the Advanced Placement English course described in this guide is designed to help students (1) want to choose from a wide range of literature for independent reading; (2) develop a critical awareness about literature; (3) recognize connections among works of…

  13. 5 CFR 359.702 - Placement rights.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Placement rights. 359.702 Section 359.702 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REMOVAL FROM THE SENIOR... rights. (a) An appointee covered by this subpart is entitled to be placed in a vacant civil service...

  14. Flapless single-tooth immediate implant placement.

    Science.gov (United States)

    de Carvalho, Breno Carnevalli Franco; de Carvalho, Elaine Manso Oliveira Franco; Consani, Rafael Leonardo Xediek

    2013-01-01

    This 15-year prospective study evaluated the success rate and preservation of the gingival margin of single implants placed in a flapless procedure loaded immediately after extraction or after a healing period. Immediate flapless implant placement was performed in patients who fulfilled specified inclusion criteria. Implants were either immediately restored with a provisional crown or left unloaded (received healing abutment only). Implant success and gingival margin levels were evaluated after implant placement and after 1 to 15 years. A total of 305 healthy nonsmoking subjects (90 men, 215 women) were treated with 430 immediate implants during a 15-year period (December 1994 to December 2009) and monitored for 1 to 15 years. Two hundred seventy-five implants received an immediate provisional crown, and 155 received a healing abutment. The implant survival rate was 93.03% (± 3.74%). The immediate provisional helped to maintain the original gingival margin, although the implant survival rate was higher for implants that were not immediately restored (96.78%) than for the implants that were immediately restored with a provisional (90.9%). This 15-year prospective study showed a favorable implant success rate related to the flapless immediate implant placement protocol with healing abutment placement or an immediate provisional crown to replace a single missing tooth.

  15. Optimization of portal placement for endoscopic calcaneoplasty

    NARCIS (Netherlands)

    van Sterkenburg, Maayke N.; Groot, Minke; Sierevelt, Inger N.; Spennacchio, Pietro A.; Kerkhoffs, Gino M. M. J.; van Dijk, C. Niek

    2011-01-01

    The purpose of our study was to determine an anatomic landmark to help locate portals in endoscopic calcaneoplasty. The device for optimal portal placement (DOPP) was developed to measure the distance from the distal fibula tip to the calcaneus (DFC) in 28 volunteers to determine the location of the

  16. Delayed bracket placement in orthodontic treatment

    Directory of Open Access Journals (Sweden)

    Chandra Wigati

    2008-12-01

    Full Text Available Background: Beside bracket position, the timing of bracket placement is one of the most essential in orthodontic treatment with fixed appliances. Even it seems simple the timing of bracket placement can be crucial and significantly influence the result of orthodontic treatment. However it is often found brackets are placed without complete understanding of its purpose and effects, which could be useless and even detrimental for the case. Purpose: The aim of this case report is to show that the timing of bracket placement could be different depending on the cases. Case: Five different cases are presented here with different timing of bracket placement. Case management: On these cases, brackets were placed on the upper arch first, on the lower arch first, or even only on some teeth first. Good and efficient orthodontic treatment results were achieved. Conclusion: For every orthodontic case, from the very beginning of treatment, bracket should be placed with the end result in mind. If brackets are correctly placed at a correct time, better treatment result could be achieved without unnecessary round tripping tooth movement.

  17. Spacer layer effect and microstructure on multi-layer [NdFeB/Nb]n films

    International Nuclear Information System (INIS)

    Tsai, J.-L.; Yao, Y.-D.; Chin, T.-S.; Kronmueller, H.

    2002-01-01

    Spacer layer effect on multi-layer [NdFeB/Nb] n films has been investigated from the variation of magnetic properties and microstructure of the films. From a HRTEM cross-section view observation, the average grain size of [NdFeB/Nb] n multi-layers was controlled by both annealing temperature and thickness of NdFeB layer. Selected area diffraction pattern indicated that the structure of Nb spacer layer was amorphous. The grain size and coercivity of [NdFeB x /Nb] n films change from 50 nm and 16.7 kOe to 167 nm and 9 kOe for films with x=40 nm, n=10 and x=200 nm, n=2, respectively

  18. Synthesis, Characterization and Biological Studies of New Linear Thermally Stable Schiff Base Polymers with Flexible Spacers.

    Science.gov (United States)

    Qureshi, Farah; Khuhawar, Muhammad Yar; Jahangir, Taj Muhammad; Channar, Abdul Hamid

    2016-01-01

    Five new linear Schiff base polymers having azomethine structures, ether linkages and extended aliphatic chain lengths with flexible spacers were synthesized by polycondensation of dialdehyde (monomer) with aliphatic and aromatic diamines. The formation yields of monomer and polymers were obtained within 75-92%. The polymers with flexible spacers of n-hexane were somewhat soluble in acetone, chloroform, THF, DMF and DMSO on heating. The monomer and polymers were characterized by melting point, elemental microanalysis, FT-IR, (1)HNMR, UV-Vis spectroscopy, thermogravimetry (TG), differential thermal analysis (DTA), fluorescence emission, scanning electron microscopy (SEM) and viscosities and thermodynamic parameters measurements of their dilute solutions. The studies supported formation of the monomer and polymers and on the basis of these studies their structures have been assigned. The synthesized polymers were tested for their antibacterial and antifungal activities.

  19. Effect of spacer layer on the magnetization dynamics of permalloy/rare-earth/permalloy trilayers

    International Nuclear Information System (INIS)

    Luo, Chen; Yin, Yuli; Zhang, Dong; Jiang, Sheng; Yue, Jinjin; Zhai, Ya; Du, Jun; Zhai, Hongru

    2015-01-01

    The permalloy/rare-earth/permalloy trilayers with different types (Gd and Nd) and thicknesses of spacer layer are investigated using frequency dependence of ferromagnetic resonance (FMR) measurements at room temperature, which shows different behaviors with different rare earth spacer layers. By fitting the frequency dependence of the FMR resonance field and linewidth, we find that the in-plane uniaxial anisotropy retains its value for all samples, the perpendicular anisotropy remains almost unchanged for different thickness of Gd layer but the values are tailored by different thicknesses of Nd layer. The Gilbert damping is almost unchanged with different thicknesses of Gd; however, the Gilbert damping is significantly enhanced from 8.4×10 −3 to 20.1×10 −3 with 6 nm of Nd and then flatten out when the Nd thickness rises above 6 nm

  20. Multilayer barrier films comprising nitrogen spacers between free-standing barrier layers

    Science.gov (United States)

    Granstrom, Jimmy; Villet, Michael; Chatterjee, Tirtha; Gerbec, Jeffrey A.; Jerkunica, Evan; Roy, Anshuman

    2009-08-01

    An encapsulation architecture for organic electronic devices utilizing nitrogen gas-phase spacers between free-standing barrier films is demonstrated. The nitrogen spacers act as sinks for permeating H2O and O2, delaying establishment of steady-state chemical potential gradients across the barriers and thereby reducing permeation rates. Water vapor transmission through nitrogen-spaced barriers was measured via the calcium optical transmission test. Substantial reductions in permeation rate were observed for a variety of barrier materials and configurations, suggesting a general and cost-effective approach for improving encapsulation performance. A low-cost polyethylene terephthalate film increases the calcium lifetime of a Cytop™-Kureha structure from 7000 to 12000 min.

  1. Transcriptome changes in STSV2-infected Sulfolobus islandicus REY15A undergoing continuous CRISPR spacer acquisition

    DEFF Research Database (Denmark)

    León-Sobrino, Carlos; Kot, Witold P; Garrett, Roger A

    2016-01-01

    A transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich and basal media over a 6 day period. Spacer acquisition preceded strong host growth retardation, altered transcriptional activity...... of four different CRISPR-Cas modules and changes in viral copy numbers, and with significant differences in the two media. Transcript levels of proteins involved in the cell cycle were reduced, while those of DNA replication, DNA repair, transcriptional regulation, and some antitoxin-toxin pairs...... and transposases were unchanged or enhanced. Antisense RNAs were implicated in the transcriptional regulation of adaptation and interference modules of the type I-A CRISPR-Cas system and evidence was found for the occurrence of functional coordination between the single CRISPR-Cas adaptation module...

  2. Metagenomic data of fungal internal transcribed spacer from serofluid dish, a traditional Chinese fermented food

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2016-03-01

    Full Text Available Serofluid dish (or Jiangshui, in Chinese, a traditional food in the Chinese culture for thousands of years, is made from vegetables by fermentation. In this work, microorganism community of the fermented serofluid dish was investigated by the culture-independent method. The metagenomic data in this article contains the sequences of fungal internal transcribed spacer (ITS regions of rRNA genes from 12 different serofluid dish samples. The metagenome comprised of 50,865 average raw reads with an average of 8,958,220 bp and G + C content is 45.62%. This is the first report on metagenomic data of fungal ITS from serofluid dish employing Illumina platform to profile the fungal communities of this little known fermented food from Gansu Province, China. The Metagenomic data of fungal internal transcribed spacer can be accessed at NCBI, SRA database accession no. SRP067411.

  3. Development and Manufacture of the Coil End Spacers of the LHC Pre-series Dipoles

    CERN Document Server

    Farina, E; Perini, D; Schiappapietra, A; Seneé, L

    2002-01-01

    The coil end spacers play an important role in the performance of superconducting coils, as their shape and location determine the mechanical stability of the conductors in the coil ends (and hence the overall coil training performance) and the local field quality. The dipole end spacers are often of a size and a geometry difficult to be industrially series manufactured and measured. Efficiency of the production and related costs are a key issue to achieve the required production rate of the LHC main dipoles at an affordable price. For the latter reasons, a design approach integrating state-of-the-art CAD/CAM optimization techniques allowing to considerably decrease design and machining time was implemented. This paper gives examples and describes the design criteria, the computation methods, the machining and measuring procedures adopted to carry out the pre-series production.

  4. A comparative study of onlay and retrorectus mesh placement in incisional hernia repair

    Directory of Open Access Journals (Sweden)

    Kundan Kharde

    2013-01-01

    Full Text Available Introduction: Incisional hernia after abdominal surgery is a well-known complication and the incidence of incisional hernias continues to be 2-11% after laparotomy. The repair of incisional hernia has always been a challenge to the surgeon. Various operative techniques for the repair of incisional hernia are in practice; however, the management is not standardized. The retro-rectus mesh placement or the sub-lay technique, popularized by Rives and Stoppa in Europe, has been reported to be quite effective, with low recurrence rates (0-23% and minimal complications. Aims and Objective: The purpose of this study was to compare the traditional on-lay mesh and retro-rectus mesh placement in incisional hernia repairs in terms of time taken for surgery, early complications (wound infections, Mesh extrusion, and Delayed complications (Recurrence. Materials and Methods: This is a prospective study which was conducted in the surgical department of our hospital. A total of 50 cases were included in this study. Of these cases, 25 cases were operated by the on-lay mesh method and 25 by retro-rectus mesh placement. Only the patients with midline hernias up to 10 cm in diameter were included in the study. Result: The operative time for retro-rectus mesh placement was insignificantly higher than that of on-lay mesh repair, whereas, complications like superficial Surgical site infection SSI were identical in both the study groups, but deep SSI leading to infection of mesh was higher in on-lay mesh repair. The recurrence rate was found to be 4% in on-lay mesh repair and 0% in retro-rectus mesh repair. Conclusion: The follow-up period in this study was 6months; hence, late recurrences were not taken into account. However, the low rate of local complications and the low recurrence rate indicate that retro-rectus mesh repair has an advantage over traditional on-lay repair.

  5. Imidacloprid and Thiamethoxam Induced Mutations in Internal Transcribed Spacer 2 (ITS2) of Anopheles stephensi

    OpenAIRE

    Bhinder, Preety; Chaudhry, Asha; Barna, Bhupinder; Kaur, Satvinderjeet

    2012-01-01

    The present article deals with the polymerase chain reaction (PCR)-based genotoxicity evaluation of neonicotinoid pesticides, imidacloprid and thiamethoxam, by using the genome of a mosquito Anopheles stephensi taken as an experimental model. After treatment of the second instar larvae with LC20 of the pesticides for 24 h, the induced nucleotide sequence variations in the internal transcribed spacer 2 (ITS2) of freshly hatched unfed control and treated individuals was studied from the sequenc...

  6. Novel electromagnetic technique for repositioning of coolant tube spacers in CANDU nuclear reactors

    Science.gov (United States)

    Dableh, Joseph H.

    1986-06-01

    A novel electromagnetic technique to reposition the coolant tube spacers in the fuel channels of CANDU nuclear reactors was successfully developed in the fall of 1983 at Ontario Hydro Research Division. The need to reposition dislocated spacers in noncommissioned reactors was discovered subsequent to the rupture of a pressure tube in one reactor at the Pickering Nuclear Generator Station in Ontario. A contributing factor to the failure of the tube was the fact that the annular spacers (garter springs), used to maintain the coaxial configuration between the pressure tube and its surrounding calandria tube, had been displaced longitudinally for a number of years. Subsequent to this finding, it was discovered that a number of garter springs in noncommissioned nuclear reactors were displaced due to vibration induced by various sources during the construction stage. Since the garter springs are not directly accessible by mechanical means, extensive dismantling of the fuel channels would have been necessary to reposition the springs in their designated locations. This paper describes a novel method to reposition the garter springs without dismantling the fuel channels. The method consists of exerting a force on the springs in the direction of the required displacement by applying a large electromagnetic impulse (generated by a 200-kJ capacitor bank) to a drive coil inserted into the pressure tube opposite the spacer. The repositioning of displaced garter springs in five new reactors in Ontario has been carried out successfully in 1984. The saving in reactor repair cost, interest charges, and replacement energy cost was on the order of hundreds of millions of dollars. Equally large benefits and savings will be realized if the need to use this technique in commissioned reactors arises. Also, the related development of strong compact coils and low-resistance pulse power cable have significant implications and advantages in various other applications related to the pulse

  7. Silver-graphene oxide based plasmonic spacer for surface plasmon-coupled fluorescence emission enhancements

    Science.gov (United States)

    Badiya, Pradeep Kumar; Srinivasan, Venkatesh; Sathish Ramamurthy, Sai

    2017-06-01

    We report the application of single layered graphene oxide (SLGO) and silver decorated SLGO (Ag-SLGO) as plasmonic spacer material for obtaining enhanced fluorescence from a Rhodamine 6G (Rh6G) radiating dipole in a surface plasmon-coupled emission platform. To this end, we have decorated SLGO with biphasic silver nanoparticles using an in situ deposition technique to achieve 112-fold fluorescence enhancements.

  8. Photo-induced antiferromagnetic interlayer coupling in Fe superlattices with iron silicide spacers

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, J.E.; Fullerton, E.E.; Kumar, S.; Lee, S.R.; Sowers, C.H.; Grimsditch, M.; Bader, S.D. [Argonne National Lab., IL (United States); Parker, F.T. [California Univ., San Diego, La Jolla, CA (United States). Center for Magnetic Recording Research

    1993-09-01

    Sputtered Fe/FeSi films possessing antiferromagnetic (AF) interlayer coupling at room temperature develop ferromagnetic remanence when cooled below 100K, but the AF coupling can be restored at low temperature by exposure to visible light of sufficient intensity (>10 mW/mm{sup 2}). We attribute these effects to charge carriers in the FeSi spacer layer which, when thermally or photo-generated, are capable of communicating spin information between the Fe layers.

  9. Experimental benchmark data for PWR rod bundle with spacer-grids

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Ontiveros, Elvis E. [Nuclear Engineering Department, Texas A and M University, College Station, TX 77843-3133 (United States); Hassan, Yassin A., E-mail: y-hassan@tamu.edu [Nuclear Engineering Department, Texas A and M University, College Station, TX 77843-3133 (United States); Conner, Michael E.; Karoutas, Zeses [Westinghouse Nuclear Fuel, 5801 Bluff Road, Columbia, SC 29209 (United States)

    2012-12-15

    In numerical simulations of fuel rod bundle flow fields, the unsteady Navier-Stokes equations have to be solved in order to determine the time (phase) dependent characteristics of the flow. In order to validate the simulations results, detailed comparison with experimental data must be done. Experiments investigating complex flows in rod bundles with spacer grids that have mixing devices (such as flow mixing vanes) have mostly been performed using single-point measurements. In order to obtain more details and insight on the discrepancies between experimental and numerical data as well as to obtain a global understanding of the causes of these discrepancies, comparisons of the distributions of complete phase-averaged velocity and turbulence fields for various locations near spacer-grids should be performed. The experimental technique Particle Image Velocimetry (PIV) is capable of providing such benchmark data. This paper describes an experimental database obtained using two-dimensional Time Resolved Particle Image Velocimetry (TR-PIV) measurements within a 5 Multiplication-Sign 5 PWR rod bundle with spacer-grids that have flow mixing vanes. One of the unique characteristic of this set-up is the use of the Matched Index of Refraction technique employed in this investigation to allow complete optical access to the rod bundle. This unique feature allows flow visualization and measurement within the bundle without rod obstruction. This approach also allows the use of high temporal and spatial non-intrusive dynamic measurement techniques namely TR-PIV to investigate the flow evolution below and immediately above the spacer. The experimental data presented in this paper includes explanation of the various cases tested such as test rig dimensions, measurement zones, the test equipment and the boundary conditions in order to provide appropriate data for comparison with Computational Fluid Dynamics (CFD) simulations. Turbulence parameters of the obtained data are presented

  10. A new spacer-guided, PCL balancing technique for cruciate-retaining total knee replacement.

    Science.gov (United States)

    Heesterbeek, P J C; Labey, L; Wong, P; Innocenti, B; Wymenga, A B

    2014-03-01

    The goal of this study was to investigate whether a new posterior cruciate ligament (PCL) balancing approach with a spacer technique during total knee arthroplasty (TKA) reproduced the correct tibiofemoral contact point (CP) location. It was hypothesized that it should be possible to adequately balance the PCL with this geometrical technique, obtaining correct position and stability of the medial femoral condyle, independent of insert shape. Nine fresh-frozen full-leg cadaver specimens were used. After native testing, prototype components of a new PCL-retaining implant were implanted using navigation and a bone-referencing technique. After finishing the bone cuts, the spacer technique was used to ascertain balancing of the PCL and the tibial cut was corrected if necessary. Passive and squat motions were performed before and after TKA using a dynamic knee simulator while tibiofemoral kinematics were recorded using six infrared cameras. CPs (native and implant) were calculated as the projections of the femoral condylar centres on the horizontal plane of the tibia. The spacer technique resulted in correct PCL balancing in all specimens. The kinematic patterns of native and replaced knees showed no statistically significant differences in passive and squat motions. The medial CP after TKA was at the same position as in the native knee. No paradoxical sliding forward was seen after TKA, supporting our hypothesis. The spacer technique can be applied by surgeons during PCL-retaining TKA and will lead to good PCL balancing, indicated by a correct CP, no lift-off in flexion and no posterior sag.

  11. Apparatus for steam generator tube wrapper spacer and support block removal

    International Nuclear Information System (INIS)

    Calhoun, G.L.; Cassette, A.J.

    1982-01-01

    A cutting torch is described that may be used to cut through the spacers and the support blocks in the annulus between the outer shell of a steam generator and a tube bundle wrapper. The torch is supported by a multi-section column made up of a number of interlocked separable aluminum channel sections carried by a motorized carriage movable vertically along a rack and guide member clamped to the wrapper

  12. Experimental benchmark data for PWR rod bundle with spacer-grids

    International Nuclear Information System (INIS)

    Dominguez-Ontiveros, Elvis E.; Hassan, Yassin A.; Conner, Michael E.; Karoutas, Zeses

    2012-01-01

    In numerical simulations of fuel rod bundle flow fields, the unsteady Navier–Stokes equations have to be solved in order to determine the time (phase) dependent characteristics of the flow. In order to validate the simulations results, detailed comparison with experimental data must be done. Experiments investigating complex flows in rod bundles with spacer grids that have mixing devices (such as flow mixing vanes) have mostly been performed using single-point measurements. In order to obtain more details and insight on the discrepancies between experimental and numerical data as well as to obtain a global understanding of the causes of these discrepancies, comparisons of the distributions of complete phase-averaged velocity and turbulence fields for various locations near spacer-grids should be performed. The experimental technique Particle Image Velocimetry (PIV) is capable of providing such benchmark data. This paper describes an experimental database obtained using two-dimensional Time Resolved Particle Image Velocimetry (TR-PIV) measurements within a 5 × 5 PWR rod bundle with spacer-grids that have flow mixing vanes. One of the unique characteristic of this set-up is the use of the Matched Index of Refraction technique employed in this investigation to allow complete optical access to the rod bundle. This unique feature allows flow visualization and measurement within the bundle without rod obstruction. This approach also allows the use of high temporal and spatial non-intrusive dynamic measurement techniques namely TR-PIV to investigate the flow evolution below and immediately above the spacer. The experimental data presented in this paper includes explanation of the various cases tested such as test rig dimensions, measurement zones, the test equipment and the boundary conditions in order to provide appropriate data for comparison with Computational Fluid Dynamics (CFD) simulations. Turbulence parameters of the obtained data are presented in order to gain

  13. Similar rate of infection eradication for functional articulating, prefabricated and custom-made spacers in 2-stage revision of the infected total hip: a literature review.

    Science.gov (United States)

    Veltman, Ewout S; Moojen, Dirk Jan F; Glehr, Mathias; Poolman, Rudolf W

    2016-07-25

    2-stage revision with the use of an antibiotic-loaded interval spacer is therapy of choice in late periprosthetic joint infection for most surgeons. For the spacer, either a prefabricated, functional articulating or custom-made spacer can be used. Little is known about which type of spacer provides optimal outcome after 2-stage revision. The aim of this study was to determine which type of spacer provides the best results, when used in 2-stage revision of an infected THA. We performed a systematic review of the literature to analyse which type of interval spacer provides highest infection eradication rate and best functional outcome after a minimum 2 year follow-up. Exclusion criteria were follow-up of less than 2 years, single-stage revision, or 2-stage revision without use of a spacer. 25 studies were included. Infection eradication rate was similar with rates of 96%, 93% and 95% for the prefabricated-, functional articulating- and custom-made spacers respectively. Functional outcome was scarcely described. Postoperative HHS was 81, 90 and 83 respectively. Functional articulating spacers achieve a comparable rate of infection eradication in the treatment of periprosthetic hip joint infections as compared to preformed or custom-made antibiotic-loaded spacers. There is insufficient evidence concerning rehabilitation and functional outcome after 2-stage revision hip arthroplasty to advocate or discourage the use of either kind of interval spacer.

  14. Cas4 Facilitates PAM-Compatible Spacer Selection during CRISPR Adaptation

    Directory of Open Access Journals (Sweden)

    Sebastian N. Kieper

    2018-03-01

    Full Text Available Summary: CRISPR-Cas systems adapt their immunological memory against their invaders by integrating short DNA fragments into clustered regularly interspaced short palindromic repeat (CRISPR loci. While Cas1 and Cas2 make up the core machinery of the CRISPR integration process, various class I and II CRISPR-Cas systems encode Cas4 proteins for which the role is unknown. Here, we introduced the CRISPR adaptation genes cas1, cas2, and cas4 from the type I-D CRISPR-Cas system of Synechocystis sp. 6803 into Escherichia coli and observed that cas4 is strictly required for the selection of targets with protospacer adjacent motifs (PAMs conferring I-D CRISPR interference in the native host Synechocystis. We propose a model in which Cas4 assists the CRISPR adaptation complex Cas1-2 by providing DNA substrates tailored for the correct PAM. Introducing functional spacers that target DNA sequences with the correct PAM is key to successful CRISPR interference, providing a better chance of surviving infection by mobile genetic elements. : Kieper et al. demonstrate that the ubiquitous protein Cas4 assists Cas1 and Cas2 in the selection of new CRISPR spacers with a PAM licensing efficient CRISPR interference. Keywords: CRISPR adaptation, Cas4, spacer acquisition, type I-D CRISPR-Cas system

  15. Design, Synthesis and Hydrolytic Behavior of Mutual Prodrugs of NSAIDs with Gabapentin Using Glycol Spacers

    Directory of Open Access Journals (Sweden)

    Hiba Najeh Alsaad

    2012-10-01

    Full Text Available The free –COOH present in NSAIDs is thought to be responsible for the GI irritation associated with all traditional NSAIDs. Exploitation of mutual prodrugs is an approach wherein the NSAID is covalently bounded to a second pharmacologically active carrier/drug with the ultimate aim of reducing the gastric irritation. In this study some NSAIDs were conjugated with gabapentin via ester bonds using glycol spacers with the expectation of reducing gastric adverse effects and obtaining synergistic analgesic effects. The kinetics of ester hydrolysis were studied in two different non enzymatic buffer solutions at pH 1.2 and 7.4, as well as in 80% human plasma using HPLC with chloroform -methanol as mobile phase. Compounds 9a–c with ethylene glycol spacers showed significant stability at buffer solutions with half lives ranging from about 8–25 h, while the underwent a reasonable plasma hydrolysis (49%–88% in 2 h. Compound 9d with a propylene glycol spacer shows a higher rate of enzymatic hydrolysis than the corresponding ethylene glycol compound 9c. The result of compounds 9a-c indicate that these compounds may be stable during their passage through the GIT until reaching the blood circulation.

  16. Procedure for vibration test of the fuel rod supported by spacer grids

    International Nuclear Information System (INIS)

    Choi, Myoung Hwan; Kang, Heung Seok; Yoon, Kyung Ho; Kim, Hyung Kyu; Song, Kee Nam

    2002-07-01

    One of the methods that are used to compare and verify the supporting performance of the spacer grids developed is the vibration characteristic test. In this report there are two aims. One is of the understand of the experimental method and procedure performing the modal testing using I-DEAS TDAS module. The other is the investigation of the vibration behaviors of a dummy fuel rod supported by 8 optimized H type spacer grids. This report describes the method and procedure of modal testing to obtain the vibration characteristics such as amplitudes, natural frequencies and mode shapes of the fuel rod using a shaker, a non-contact gap sensor and an accelerometer. This report provides a test procedure in detail so that anyone can be easily understood and use the I-DEAS TDAS program. The I-DEAS TDAS program related to the modal testing has several tasks including the Modal analysis, Signal Processing et al.. This report includes model preparation to prepare the geometrical model, Signal Processing (Sine/Standard measurement) to acquire the signal, Modal analysis to obtain the frequencies and mode shapes, Correlation to analyze the relation between the test and FE analysis and Post Processing tasks. In addition, this report contains the actual test and analysis data of a dummy fuel rod in length 3847mm supported by 8 optimized H type spacer grids

  17. Finite element analysis of the contact between fuel rod and spacer grid

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kyu; Kim, Young Koon; Kang, Heung Seok; Yoon, Kyung Ho; Song, Kee Nam [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-01-01

    For the research on the fretting failure problem of nuclear fuel, the contact length and normal stress field are evaluated for the contact between fuel rod and spacer grid by using the Finite Element Method (FEM). An assumption of semi-infiniteness is necessary for applying the Contact Mechanics which is based on the classical theory of elasticity to the present problem. For the contact problem of fuel fretting, the contact mechanical solutions could be utilized well with sufficient accuracy if the contact bodies (i.e., the cladding tube and the spacer grid) can be assumed as semi-infinite bodies. To this end, the contact length evaluated by FEM is discussed together with the relevant research which concerned the effect of dimension for the validity of the assumption of semi-infiniteness. Normal stress profile on the contact is also studied through comparing the theoretical and the FE results. For the analysis of contact problem by FEM, ANSYS code (Version 5.3) is utilized and the geometry is chosen to be the Hertzian (cylinder-to-cylinder), the strip-to-cylinder and the fuel rod/spacer grid contact (strip-to-tube). Present research will be utilized for accessing the fuel fretting problem by FEM together with the theoretical (i.e., contact mechanical) analysis which has been published as KAERI/TR-1113/98. (author). 15 refs., 44 figs., 4 tabs.

  18. A data-mining approach to spacer oligonucleotide typing of Mycobacterium tuberculosis.

    Science.gov (United States)

    Sebban, M; Mokrousov, I; Rastogi, N; Sola, C

    2002-02-01

    The Direct Repeat (DR) locus of Mycobacterium tuberculosis is a suitable model to study (i) molecular epidemiology and (ii) the evolutionary genetics of tuberculosis. This is achieved by a DNA analysis technique (genotyping), called sp acer oligo nucleotide typing (spoligotyping ). In this paper, we investigated data analysis methods to discover intelligible knowledge rules from spoligotyping, that has not yet been applied on such representation. This processing was achieved by applying the C4.5 induction algorithm and knowledge rules were produced. Finally, a Prototype Selection (PS) procedure was applied to eliminate noisy data. This both simplified decision rules, as well as the number of spacers to be tested to solve classification tasks. In the second part of this paper, the contribution of 25 new additional spacers and the knowledge rules inferred were studied from a machine learning point of view. From a statistical point of view, the correlations between spacers were analyzed and suggested that both negative and positive ones may be related to potential structural constraints within the DR locus that may shape its evolution directly or indirectly. By generating knowledge rules induced from decision trees, it was shown that not only the expert knowledge may be modeled but also improved and simplified to solve automatic classification tasks on unknown patterns. A practical consequence of this study may be a simplification of the spoligotyping technique, resulting in a reduction of the experimental constraints and an increase in the number of samples processed.

  19. Insufficient sensitivity of joint aspiration during the two-stage exchange of the hip with spacers.

    Science.gov (United States)

    Boelch, Sebastian Philipp; Weissenberger, Manuel; Spohn, Frederik; Rudert, Maximilian; Luedemann, Martin

    2018-01-10

    Evaluation of infection persistence during the two-stage exchange of the hip is challenging. Joint aspiration before reconstruction is supposed to rule out infection persistence. Sensitivity and specificity of synovial fluid culture and synovial leucocyte count for detecting infection persistence during the two-stage exchange of the hip were evaluated. Ninety-two aspirations before planned joint reconstruction during the two-stage exchange with spacers of the hip were retrospectively analyzed. The sensitivity and specificity of synovial fluid culture was 4.6 and 94.3%. The sensitivity and specificity of synovial leucocyte count at a cut-off value of 2000 cells/μl was 25.0 and 96.9%. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values were significantly higher before prosthesis removal and reconstruction or spacer exchange (p = 0.00; p = 0.013 and p = 0.039; p = 0.002) in the infection persistence group. Receiver operating characteristic area under the curve values before prosthesis removal and reconstruction or spacer exchange for ESR were lower (0.516 and 0.635) than for CRP (0.720 and 0.671). Synovial fluid culture and leucocyte count cannot rule out infection persistence during the two-stage exchange of the hip.

  20. Sub-22 nm silicon template nanofabrication by advanced spacer patterning technique for NIL applications

    Science.gov (United States)

    Park, Jong-Moon; Park, Kun-Sik; Kim, Dong-Pyo; Yoo, Seong-Ook; Lee, Jin-Ho

    2013-03-01

    A spacer patterning technique using a poly-Si micro-feature and a SiO2 spacer has been demonstrated to achieve sub-22 nm structures with conventional semiconductor equipments. The sub-22 nm structures have been fabricated by a plasma etching of Si substrate with a spacer oxide mask of which dimension is accurately controlled by the deposited film thickness. The profile of the Si nano-feature was influenced by an O2 flow rate during Si etching in inductively coupled plasma (ICP). As the O2 flow rate was decreased, the etch profile was improved vertically even though the etch rate of Si was slightly decreased. We obtained a 6-inch Si template with both nano- and micro-features of positive shape used for a master mold in nanoimprint lithography (NIL). The nano-sized Si features showed 22-nm width and 145-nm height with the slope of 87°. Further size reduction by anisotropic wet etching with KOH solution was also investigated.

  1. Unsteadiness and transition to turbulence in woven spacer filled channels for Membrane Distillation

    Science.gov (United States)

    Ciofalo, M.; Ponzio, F.; Tamburini, A.; Cipollina, A.; Micale, G.

    2017-01-01

    To characterize the performance of Membrane Distillation (MD) modules, channels filled with woven spacers were investigated by Computational Fluid Dynamics (including Direct Numerical Simulations and the use of the SST k-ω turbulence model) and by parallel experiments with Thermochromic Liquid Crystals. The cases considered here regard mutually orthogonal filaments with a spacer pitch to channel height ratio P/H=2, two spacer orientations θ with respect to the main flow (0° and 45°), and bulk Reynolds numbers Re from ∼200 to ∼2000, an interval of great interest in practical MD applications. For both values of θ, CFD predicted steady-state flow for Re up to ∼300, and chaotic flow for Re larger than ∼400. In the intermediate range Re≈300-400, periodic flow regimes were predicted for both orientations. These regimes were of particular interest and complexity, as they exhibited a slow global oscillation of the flow superimposed on high order harmonics corresponding to fast local oscillations. Experiments confirmed the appearance of unsteadiness for Re>∼300. Heat transfer and friction were little affected by unsteadiness and exhibited a smooth behaviour with Re. The agreement with the experimental results was good using DNS, and acceptable using RANS.

  2. Interaction between zircaloy tube and inconel spacer grid at high temperature

    International Nuclear Information System (INIS)

    Nagase, Fumihisa; Otomo, Takashi; Uetsuka, Hiroshi; Furuta, Teruo

    1990-09-01

    In order to investigate the interaction between fuel cladding and spacer grid of the pressurized water reactor during a severe accident, isothermal reaction tests were performed at the temperature range from 1248 to 1673K. A specimen consisted of a short Zircaloy-4 cladding tube and a piece of spacer grid of Inconel-718. In the tests in an argon atmosphere, eutectic reaction between Zircaloy and Inconel was observed at the contact points at 1248K. Rapid reaction was observed at higher test temperatures. For example, in the test at 1373K for 300s, Zircaloy reacted with Inconel over the entire thickness (0.62mm) of the tube in the vicinity of the contact point. In the present tests, Zircaloy which has higher melting point than Inconel was dissolved preferentially due to eutectic formation. In the tests in an oxygen atmosphere, no eutectic reaction was observed at temperatures below 1437K. A trace of interaction was found at the contact point of specimen heated at 1573 and 1623K. However, decrease in Zircaloy thickness was not measured. The possibility of eutectic reaction between Zircaloy cladding and Inconel spacer grid seems to be quite limited when sufficient oxygen is supplied. (author)

  3. Design, synthesis and hydrolytic behavior of mutual prodrugs of NSAIDs with gabapentin using glycol spacers.

    Science.gov (United States)

    Mahdi, Monther Faisal; Alsaad, Hiba Najeh

    2012-10-12

    The free –COOH present in NSAIDs is thought to be responsible for the GI irritation associated with all traditional NSAIDs. Exploitation of mutual prodrugs is an approach wherein the NSAID is covalently bounded to a second pharmacologically active carrier/drug with the ultimate aim of reducing the gastric irritation. In this study some NSAIDs were conjugated with gabapentin via ester bonds using glycol spacers with the expectation of reducing gastric adverse effects and obtaining synergistic analgesic effects. The kinetics of ester hydrolysis were studied in two different non enzymatic buffer solutions at pH 1.2 and 7.4, as well as in 80% human plasma using HPLC with chloroform -methanol as mobile phase. Compounds 9a–c with ethylene glycol spacers showed significant stability at buffer solutions with half lives ranging from about 8–25 h, while the underwent a reasonable plasma hydrolysis (49%–88%) in 2 h. Compound 9d with a propylene glycol spacer shows a higher rate of enzymatic hydrolysis than the corresponding ethylene glycol compound 9c. The result of compounds 9a-c indicate that these compounds may be stable during their passage through the GIT until reaching the blood circulation.

  4. Immediate placement of endosseous implants into the extraction sockets

    OpenAIRE

    Vijay Ebenezer; K Balakrishnan; R Vigil Dev Asir; Banu Sragunar

    2015-01-01

    Implant by definition ?means any object or material, such as an alloplastic substance or other tissue, which is partial or completely inserted into the body for therapeutic, diagnostic, prosthetic, or experimental purpose.? The placement of a dental implant in an extraction socket at the time of extraction or explantation is known as immediate implant placement whereas delayed placement of implant signifies the implant placement in edentulous areas where healing has completed with new bone fo...

  5. Advantages of the paraspinal muscle splitting approach in comparison with conventional midline approach for s1 pedicle screw placement.

    Science.gov (United States)

    Ota, Masato; Neo, Masashi; Fujibayashi, Shunsuke; Takemoto, Mitsuru; Nakamura, Takashi

    2010-05-15

    A retrospective comparative study of the S1 pedicle screw (S1PS) position obtained using 2 surgical approaches. To determine whether the paraspinal approach leads to more medially oriented placement of the S1PS compared with the midline approach. To obtain a stronger as well as safer fixation of the S1PS, medially oriented screw placement is very important. However, no study has recommended a surgical approach to achieve this object. The positions of 32 screws placed by the midline approach and 34 screws placed by the paraspinal approach were compared using postoperative computed tomography. The location of the bilateral common iliac veins (CIV) in relation to the S1PS tips was also analyzed to evaluate their safety. There was no statistical difference in screw insertion point regardless of the approach employed. However, in the paraspinal group the S1PS were placed with significantly greater medial direction and with longer screws. In addition, they pierced the anterior sacral cortex closer to the midline compared with the midline approach. Four left screws in the midline approach group made contact with the left CIV, whereas no screw in the paraspinal approach group lay adjacent to the CIV. Our results demonstrate that the paraspinal approach for S1PS placement may be superior to the midline approach in terms of the medially oriented screw placement that is biomechanically stronger and less risky for the CIV.

  6. Effect of electrostatic charge in plastic spacers on the lung delivery of HFA-salbutamol in children

    DEFF Research Database (Denmark)

    Anhøj, J; Bisgaard, H; Lipworth, B J

    1999-01-01

    was delivered on 3 different study days from plastic spacers with mouthpiece. Pre-treatment of the spacers differed between study days: (a) Non-electrostatic 350 ml Babyhaler (coated with benzalkonium chloride) (b) New 350 ml Babyhaler (rinsed in water), and (c) New 145 ml AeroChamber (rinsed in water). Plasma......AIMS: The effect of the electrostatic charge in plastic spacers in vivo on drug delivery to the lung of hydrofluoroalkane (HFA) salbutamol spray was studied in children. METHODS: Five children, aged 7-12 years, were included in a 3-way crossover randomised single-blind trial. Salbutamol HFA spray...... delivered a significantly (Pplastic spacers reduces lung dose in children by more than two-fold. This is clinically significant and the use of potentially electrostatically charged...

  7. INFLUENCE OF THE SIZE OF METHYLENE SPACERS ON THE THERMAL BEHAVIOR OF SEVERAL ALIPHATIC-AROMATIC POLYESTERS

    Directory of Open Access Journals (Sweden)

    NATALIA HURDUC

    2014-04-01

    Full Text Available Polyesters have a wide range of technical applications and therefore their processing is of the utmost importance. Since polyesters are usually processed by melting, their thermal stability is an extremely important characteristic for the exact determination of the operational parameters. The thermal analysis was carried out using a MOM-Budapest derivatograph at the 10 C/min heating speed, aluminum oxide the reference material, and the air conditions were static. The study lead to conclusions on the thermal stability and degradation mechanism depending on the number of methylene groups in the spacer. Thermal stability is supported by the increase in the number of methylene groups in the spacer. The degradation mechanism is complex through successive reactions. The spacer size influences the nature of the micromolecules formed by spacer fragmenting and by the number of carbon atoms, respectively.

  8. Review and Comparison of simulation software for additive manufacturing process: the practical case of dipole End-Spacers

    CERN Document Server

    Vevers, Arturs

    2017-01-01

    Project was made to compare and benchmark simulation software for additive manufacturing. Simulations for End-spacers and HOM crab cavity were made to compare simulation results with 3D scanned data for these parts.

  9. Spacer Thickness-Dependent Electron Transport Performance of Titanium Dioxide Thick Film for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Reda E. El-Shater

    2015-01-01

    Full Text Available A titanium dioxide (P25 film was deposited by cast coating as conductive photoelectrode and subsequently immersed in dye solution (N719 to fabricate the photoanode of dye-sensitized solar cells (DSSCs. A plastic spacer was used as a separation and sealant layer between the photoanode and the counter electrode. The effect of the thickness of this spacer on the transfer of electrons in the liquid electrolyte of the DSSCs was studied by means of both IV curves and electrochemical impedance. Using a spacer thickness range of 20 μm to 50 μm, efficiency ranges from 3.73% to 7.22%. The highest efficiency of 7.22% was obtained with an optimal spacer thickness of 40 μm.

  10. Low-velocity impact behavior of weft-knitted spacer fabrics reinforced composites based on energy absorption

    Science.gov (United States)

    Hasanalizadeh, F.; Dabiryan, H.; Sadighi, M.

    2017-10-01

    Spacer fabrics are prefered to other types of textile fabrics in energy absorption applications due to existence of pile yarns. The particular geometry of spacer fabrics induce to increase resisting out of plane forces such as impact along their thickness. In order to investigate the low-velocity impact behaviour of composites reinforced with spacer fabric, weft-knitted spacer fabrics with different types of pile orientation and pile length were produced using E-glass yarns. Using produced fabrics and epoxy resin, composites samples were provided by hand lay-up method. Low-velocity impact test was carried out on the prepared samples based on a drop-weight method using spherical steel projectile. The indentation at maximum force was extracted as - comparative criteria used to calculate absorbed energy.The results show that the energy absorption of composites increases by increasing the pile density and pile length.

  11. Review of the correlation developments and a new concept based on mixing mechanism for heat transfer enhancement of spacer grids

    Energy Technology Data Exchange (ETDEWEB)

    Mao, H.; Yang, B.W.; Liu, X. [Xi' an Jiaotong Univ., Shaanxi (China). Science and Technology Center for Advanced Nuclear Fuel Research

    2016-07-15

    Spacer grids could cause heat transfer enhancement both at the spacer grid regions and downstream of the spacer grids as a result of mixing promoted by the spacer grids in the rod bundle. This phenomenon has been demonstrated by many experiments, and several correlations have been developed based on these experimental data. This paper gives a review of the grid-enhanced heat transfer correlation developments in single phase flow. Following the exploration of the correlation development history, a predictive formulation of grid-enhanced heat transfer in single phase flow is established taking into account the effect of both swirl flow and crossflow. With emphasis on modeling of the mixing mechanism associated with the mixing vane grid, the new correlation could better reflect the physical process of the heat transfer augmentation, while a large number of experimental data are needed to determine the coefficients of the new correlation.

  12. Long-term Results of Endovascular Stent Graft Placement of Ureteroarterial Fistula

    International Nuclear Information System (INIS)

    Okada, Takuya; Yamaguchi, Masato; Muradi, Akhmadu; Nomura, Yoshikatsu; Uotani, Kensuke; Idoguchi, Koji; Miyamoto, Naokazu; Kawasaki, Ryota; Taniguchi, Takanori; Okita, Yutaka; Sugimoto, Koji

    2013-01-01

    PurposeTo evaluate the safety, efficacy, and long-term results of endovascular stent graft placement for ureteroarterial fistula (UAF).MethodsWe retrospectively analyzed stent graft placement for UAF performed at our institution from 2004 to 2012. Fistula location was assessed by contrast-enhanced computed tomography (CT) and angiography, and freedom from hematuria recurrence and mortality rates were estimated.ResultsStent graft placement for 11 UAFs was performed (4 men, mean age 72.8 ± 11.6 years). Some risk factors were present, including long-term ureteral stenting in 10 (91 %), pelvic surgery in 8 (73 %), and pelvic radiation in 5 (45 %). Contrast-enhanced CT and/or angiography revealed fistula or encasement of the artery in 6 cases (55 %). In the remaining 5 (45 %), angiography revealed no abnormality, and the suspected fistula site was at the crossing area between urinary tract and artery. All procedures were successful. However, one patient died of urosepsis 37 days after the procedure. At a mean follow-up of 548 (range 35–1,386) days, 4 patients (36 %) had recurrent hematuria, and two of them underwent additional treatment with secondary stent graft placement and surgical reconstruction. The hematuria recurrence-free rates at 1 and 2 years were 76.2 and 40.6 %, respectively. The freedom from UAF-related and overall mortality rates at 2 years were 85.7 and 54.9 %, respectively.ConclusionEndovascular stent graft placement for UAF is a safe and effective method to manage acute events. However, the hematuria recurrence rate remains high. A further study of long-term results in larger number of patients is necessary

  13. An alternative method for flapless implant placement and an immediate provisional crown: a case report.

    Science.gov (United States)

    Turkyilmaz, Ilser; Suarez, Jose Carlos

    2009-05-01

    The aim of this case report is to present a description of bone mapping as an alternative method to determine the dimensions of bone prior to placement of a flapless implant and an immediate provisional crown. The use of a temporary removable partial denture (RPD) or "flipper" during healing following an extraction is not acceptable for some highly demanding patients. As a result, flapless implant placement is gaining popularity because it offers some advantages such as less bleeding, less swelling, and the protection of soft tissue contours. A 65-year-old woman missing a maxillary left lateral incisor was treated using flapless implant placement and an immediate provisional acrylic crown. Under local anesthesia, the bone anatomy was mapped by inserting a standard periodontal probe in the gingiva. By using the recorded measurements, the thickness of soft tissue was removed from the cast. A surgical guide based on this adjusted model was fabricated prior to surgery. The guide was seated on the teeth when actual surgery was performed to facilitate bone drilling and then the implant was placed. Utilizing the previously fabricated acrylic tooth index, the temporary acrylic crown was fabricated on the adjusted temporary metal abutment and delivered to the patient the same day. In this case report the missing maxillary left lateral tooth was restored using flapless implant placement and an immediate provisional single crown. The dimension of the bone at the implant recipient area was determined by an alternative bone mapping method. This case report suggests the use of flapless implant placement using the bone mapping method and immediate provisional crowns for single crowns when esthetics are a high priority and preserving ideal soft tissue contours and papillary heights are critical.

  14. Cannot ventilate-cannot intubate an infant: surgical tracheotomy or transtracheal cannula?

    DEFF Research Database (Denmark)

    Johansen, Karina; Holm-Knudsen, Rolf J; Charabi, Birgitte

    2010-01-01

    An unanticipated difficult airway is very uncommon in infants. The recommendations for managing the cannot ventilate-cannot intubate (CVCI) situation in infants and small children are based on difficult airway algorithms for adults. These algorithms usually recommend placement of a transtracheal...... cannula or performing a surgical tracheotomy as a last resort. In this study, we compared the success rate and time used for inserting a transtracheal cannula vs performing a modified surgical tracheotomy in a piglet model....

  15. Determining the brand awareness of product placement in video games

    OpenAIRE

    Král, Marek

    2015-01-01

    This bachelor thesis focusses on the determination of the brand awareness of product placement in video games. The theoretical part includes information about marketing, product placement and video games. The practical part consists of evaluation of the market research about product placements in video games. Conclusion suggests the most important factors influencing the level brand awareness.

  16. Brand Placement and Consumer Choice: An in-Store Experiment

    Science.gov (United States)

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior.…

  17. Optimal capacitor sizing and placement based on real time analysis ...

    African Journals Online (AJOL)

    In this paper, optimal capacitor sizing and placement method was used to improve energy efficiency. It involves the placement of capacitors in a specific location with suitable sizing based on the current load of the electrical system. The optimization is done in real time scenario where the sizing and placement of the ...

  18. 20 CFR 638.409 - Placement and job development.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Placement and job development. 638.409 Section 638.409 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR JOB CORPS... Placements in the Job Corps § 638.409 Placement and job development. The overall objective of all Job Corps...

  19. Effect of electrostatic charge in plastic spacers on the lung delivery of HFA-salbutamol in children

    DEFF Research Database (Denmark)

    Anhøj, J; Bisgaard, H; Lipworth, B J

    1999-01-01

    AIMS: The effect of the electrostatic charge in plastic spacers in vivo on drug delivery to the lung of hydrofluoroalkane (HFA) salbutamol spray was studied in children. METHODS: Five children, aged 7-12 years, were included in a 3-way crossover randomised single-blind trial. Salbutamol HFA spray...... delivered a significantly (Pcharge in plastic spacers reduces lung dose in children by more than two-fold. This is clinically significant and the use of potentially electrostatically charged...

  20. Distribution of CRISPR spacer matches in viruses and plasmids of crenarchaeal acidothermophiles and implications for their inhibitory mechanism

    DEFF Research Database (Denmark)

    Shah, Shiraz Ali; Hansen, Niels R; Garrett, Roger A

    2009-01-01

    Transcripts from spacer sequences within chromosomal repeat clusters [CRISPRs (clusters of regularly interspaced palindromic repeats)] from archaea have been implicated in inhibiting or regulating the propagation of archaeal viruses and plasmids. For the crenarchaeal thermoacidophiles, the chromo......Transcripts from spacer sequences within chromosomal repeat clusters [CRISPRs (clusters of regularly interspaced palindromic repeats)] from archaea have been implicated in inhibiting or regulating the propagation of archaeal viruses and plasmids. For the crenarchaeal thermoacidophiles...

  1. MO-AB-BRA-02: Modeling Nanoparticle-Eluting Spacer Degradation During Brachytherapy Application with in Situ Dose-Painting

    Energy Technology Data Exchange (ETDEWEB)

    Boateng, F [University of Massachusetts Lowell, Lowell, Massachusetts (United States); Ngwa, W [University of Massachusetts Lowell, Lowell, Massachusetts (United States); Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Brachytherapy application with in situ dose-painting using gold nanoparticles (GNP) released from GNP-loaded brachytherapy spacers has been proposed as an innovative approach to increase therapeutic efficacy during brachytherapy. This work investigates the dosimetric impact of slow versus burst release of GNP from next generation biodegradable spacers. Methods: Mathematical models were developed based on experimental data to study the release of GNP from a spacer designed with FDA approved poly(lactic-co-glycolic acid) (PLGA) polymer. The diffusion controlled released process and PLGA polymer degradation kinetics was incorporated in the calculations for the first time. An in vivo determined diffusion coefficient was used for determining the concentration profiles and corresponding dose enhancement based on initial GNP-loading concentrations of 7 mg/g. Results: The results showed that there is significant delay before the concentration profile of GNP diffusion in the tumor is similar to that when burst release is assumed as in previous studies. For example, in the case of burst release after spacer administration, it took up to 25 days for all the GNP to be released from the spacer using diffusion controlled release process only. However, it took up to 45 days when a combined model for both diffusion and polymer degradation processes was used. Based on the tumor concentration profiles, a significant dose enhancement factor (DEF >20%), could be attained at a tumor distances of 5 mm from a spacer loaded with 10 nm GNP sizes. Conclusion: The results highlight the need to take the slow release of GNP from spacers and factors such as biodegradation of polymers into account in research development of GNP-eluting spacers for brachytherapy applications with in-situ dose-painting using gold nanoparticles. The findings suggest that I-125 may be the more appropriate for such applications given the relatively longer half-live compared to other radioisotopes like Pd-103

  2. Feasibility and Accuracy of Thoracolumbar Minimally Invasive Pedicle Screw Placement With Augmented Reality Navigation Technology.

    Science.gov (United States)

    Elmi-Terander, Adrian; Nachabe, Rami; Skulason, Halldor; Pedersen, Kyrre; Söderman, Michael; Racadio, John; Babic, Drazenko; Gerdhem, Paul; Edström, Erik

    2017-12-19

    Cadaveric laboratory study. To assess the feasibility and accuracy of minimally invasive thoracolumbar pedicle screw placement using augmented reality (AR) surgical navigation SUMMARY OF BACKGROUND DATA.: Minimally invasive spine (MIS) surgery has increasingly become the method of choice for a wide variety of spine pathologies. Navigation technology based on AR has been shown to be feasible, accurate and safe in open procedures. AR technology may also be used for MIS surgery. The AR surgical navigation was installed in a hybrid operating room (OR). The hybrid OR includes a surgical table, a motorized flat detector C-arm with intraoperative 2D/3D imaging capabilities, integrated optical cameras for AR navigation and patient motion tracking using optical markers on the skin. Navigation and screw placement was without any X-ray guidance. Two neurosurgeons placed 66 Jamshidi needles (2 cadavers) and 18 cannulated pedicle screws (1 cadaver) in the thoracolumbar spine. Technical accuracy was evaluated by measuring the distance between the tip of the actual needle position and the corresponding planned path as well as the angles between the needle and the desired path. Time needed for navigation along the virtual planned path was measured. An independent reviewer assessed the postoperative scans for the pedicle screws' clinical accuracy. Navigation time per insertion was 90 ± 53 seconds with an accuracy of 2.2 ± 1.3 mm. Accuracy was not dependent on operator. There was no correlation between navigation time and accuracy. The mean error angle between the Jamshidi needles and planned paths was 0.9 ± 0.8°. No screw was misplaced outside the pedicle. Two screws breached 2 to 4 mm yielding an overall accuracy of 89% (16/18). MIS screw placement directed by AR with intraoperative 3D imaging in a hybrid OR is accurate and efficient, without any fluoroscopy or X-ray imaging during the procedure. 4.

  3. Preclinical usability study of multiple augmented reality concepts for K-wire placement.

    Science.gov (United States)

    Fischer, Marius; Fuerst, Bernhard; Lee, Sing Chun; Fotouhi, Javad; Habert, Severine; Weidert, Simon; Euler, Ekkehard; Osgood, Greg; Navab, Nassir

    2016-06-01

    In many orthopedic surgeries, there is a demand for correctly placing medical instruments (e.g., K-wire or drill) to perform bone fracture repairs. The main challenge is the mental alignment of X-ray images acquired using a C-arm, the medical instruments, and the patient, which dramatically increases in complexity during pelvic surgeries. Current solutions include the continuous acquisition of many intra-operative X-ray images from various views, which will result in high radiation exposure, long surgical durations, and significant effort and frustration for the surgical staff. This work conducts a preclinical usability study to test and evaluate mixed reality visualization techniques using intra-operative X-ray, optical, and RGBD imaging to augment the surgeon's view to assist accurate placement of tools. We design and perform a usability study to compare the performance of surgeons and their task load using three different mixed reality systems during K-wire placements. The three systems are interventional X-ray imaging, X-ray augmentation on 2D video, and 3D surface reconstruction augmented by digitally reconstructed radiographs and live tool visualization. The evaluation criteria include duration, number of X-ray images acquired, placement accuracy, and the surgical task load, which are observed during 21 clinically relevant interventions performed by surgeons on phantoms. Finally, we test for statistically significant improvements and show that the mixed reality visualization leads to a significantly improved efficiency. The 3D visualization of patient, tool, and DRR shows clear advantages over the conventional X-ray imaging and provides intuitive feedback to place the medical tools correctly and efficiently.

  4. Face and content validity of a virtual-reality simulator for myringotomy with tube placement.

    Science.gov (United States)

    Huang, Caiwen; Cheng, Horace; Bureau, Yves; Agrawal, Sumit K; Ladak, Hanif M

    2015-10-20

    Myringotomy with tube insertion can be challenging for junior Otolaryngology residents as it is one of the first microscopic procedures they encounter. The Western myringotomy simulator was developed to allow trainees to practice microscope positioning, myringotomy, and tube placement. This virtual-reality simulator is viewed in stereoscopic 3D, and a haptic device is used to manipulate the digital ear model and surgical tools. To assess the face and content validity of the Western myringotomy simulator. The myringotomy simulator was integrated with new modules to allow speculum placement, manipulation of an operative microscope, and insertion of the ventilation tube through a deformable tympanic membrane. A questionnaire was developed in consultation with instructing surgeons. Fourteen face validity questions focused on the anatomy of the ear, simulation of the operative microscope, appearance and movement of the surgical instruments, deformation and cutting of the eardrum, and myringotomy tube insertion. Six content validity questions focused on training potential on surgical tasks such as speculum placement, microscope positioning, tool navigation, ear anatomy, myringotomy creation and tube insertion. A total of 12 participants from the Department of Otolaryngology-Head and Neck Surgery were recruited for the study. Prior to completing the questionnaire, participants were oriented to the simulator and given unlimited time to practice until they were comfortable with all of its aspects. Responses to 12 of the 14 questions on face validity were predominantly positive. One issue of concern was with contact modeling related to tube insertion into the eardrum, and the second was with the movement of the blade and forceps. The former could be resolved by using a higher resolution digital model for the eardrum to improve contact localization. The latter could be resolved by using a higher fidelity haptic device. With regard to content validity, 64% of the responses

  5. PEG spacers of different length influence the biological profile of bombesin-based radiolabeled antagonists

    International Nuclear Information System (INIS)

    Jamous, Mazen; Tamma, Maria L.; Gourni, Eleni; Waser, Beatrice; Reubi, Jean C.; Maecke, Helmut R.; Mansi, Rosalba

    2014-01-01

    Introduction: The gastrin-releasing peptide receptor (GRPR) was shown to be expressed with high density on several types of cancers. Radiolabeled peptides for imaging and targeted radionuclide therapy have been developed. In this study, we evaluated the potential of statine-based bombesin antagonists, conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) through oligoethyleneglycol spacers, labeled with 177 Lu and we determined the effect of polyethyleneglycol (PEG) spacer length on in vitro and in vivo properties. Methods: The bombesin antagonists were synthesized on solid phase using Fmoc chemistry; the spacers Fmoc-dPEG x -OH (x = 2, 4, 6 and 12) and the DOTA(tBu) 3 were coupled using a standard procedure. The peptides were labeled with 177 Lu and evaluated in vitro (lipophilicity, serum stability, internalization and binding affinity assays). Biodistribution studies were performed in PC-3 tumor-bearing nude mice. Results: The solid-phase synthesis was straightforward with an overall yield ranging from 30% to 35% based on the first Fmoc cleavage. The hydrophilicity increased with spacer length (logD: − 1.95 vs − 2.22 of PEG 2 and PEG 12 analogs, respectively). There is a tendency of increased serum stability by increasing the spacer length (T 1/2 = 246 ± 4 and 584 ± 20 for PEG 2 and PEG 6 analogs, respectively) which seems to reverse with the PEG 12 analog. The IC 50 values are similar with the only significant difference of the PEG 12 analog. The 177 Lu-labeled PEG 4 and PEG 6 conjugates showed similar pharmacokinetic with high tumor uptake and excellent tumor-to-kidney ratios (7.8 and 9.7 at 4 h for the PEG 4 and PEG 6 derivatives, respectively). The pancreas uptake was relatively high at 1 h but it shows fast washout (0.46% ± 0.02% IA/g and 0.29% ± 0.08% IA/g already at 4 h). Conclusion: Among all the studied analogs the PEG 4 and PEG 6 showed significantly better properties. The very high tumor-to-non-target organ ratios, in

  6. Dansyl-naphthalimide dyads as molecular probes: effect of spacer group on metal ion binding properties.

    Science.gov (United States)

    Shankar, Balaraman H; Ramaiah, Danaboyina

    2011-11-17

    Interaction of a few dansyl-naphthalimide conjugates 1a-e linked through polymethylene spacer groups with various metal ions was investigated through absorption, fluorescence, NMR, isothermal calorimetric (ITC), and laser flash photolysis techniques. The characteristic feature of these dyads is that they exhibit competing singlet-singlet energy transfer (SSET) and photoinduced electron transfer (PET) processes, both of which decrease with the increase in spacer length. Depending on the spacer group, these dyads interact selectively with divalent Cu(2+) and Zn(2+) ions, as compared to other mono- and divalent metal ions. Jobs plot analysis showed that these dyads form 2:3 complexes with Cu(2+) ions, while 1:1 complexes were observed with Zn(2+) ions. The association constants for the Zn(2+) and Cu(2+) complexes were determined and are found to be in the order 10(3)-10(5) M(-1). Irrespective of the length of the spacer group, these dyads interestingly act as fluorescence ratiometric molecular probes for Cu(2+) ions by altering the emission intensity of both dansyl and naphthalimide chromophores. In contrast, only the fluorescence intensity of the naphthalimide chromophore of the lower homologues (n = 1-3) was altered by Zn(2+) ions. (1)H NMR and ITC measurements confirmed the involvement of both sulfonamide and dimethylamine groups in the complexation with Cu(2+) ions, while only the latter group was involved with Zn(2+) ions. Laser excitation of the dyads 1a-e showed formation of a transient absorption which can be attributed to the radical cation of the naphthalimide chromophore, whereas only the triplet excited state of the dyads 1a-e was observed in the presence of Cu(2+) ions. Uniquely, the complexation of 1a-e with Cu(2+) ions affects both PET and SSET processes, while only the PET process was partially inhibited by Zn(2+) ions in the lower homologues (n = 1-3) and the higher homologues exhibited negligible changes in their emission properties. Our results

  7. Measurements of Epidural Space Depth Using Preexisting CT Scans Correlate with Loss of Resistance Depth during Thoracic Epidural Catheter Placement

    Directory of Open Access Journals (Sweden)

    Nathaniel H. Greene

    2015-01-01

    Full Text Available Background. Thoracic epidural catheters provide the best quality postoperative pain relief for major abdominal and thoracic surgical procedures, but placement is one of the most challenging procedures in the repertoire of an anesthesiologist. Most patients presenting for a procedure that would benefit from a thoracic epidural catheter have already had high resolution imaging that may be useful to assist placement of a catheter. Methods. This retrospective study used data from 168 patients to examine the association and predictive power of epidural-skin distance (ESD on computed tomography (CT to determine loss of resistance depth acquired during epidural placement. Additionally, the ability of anesthesiologists to measure this distance was compared to a radiologist, who specializes in spine imaging. Results. There was a strong association between CT measurement and loss of resistance depth (P35 changed this relationship (P=0.007. The ability of anesthesiologists to make CT measurements was similar to a gold standard radiologist (all individual ICCs>0.9. Conclusions. Overall, this study supports the examination of a recent CT scan to aid in the placement of a thoracic epidural catheter. Making use of these scans may lead to faster epidural placements, fewer accidental dural punctures, and better epidural blockade.

  8. A Comparison of Flow Field Characteristics from PIV Experiment Measurement to Numerical Simulation behind a Spacer in a Vertical Pipe

    Directory of Open Access Journals (Sweden)

    Lávička D.

    2010-07-01

    Full Text Available This paper describes the topic of measurement using a modern laser method (PIV in an annular channel of very small dimensions. The annular channel simulates the flow area around a model of a fuel rod in the VVER nuclear reactor. The annular channel holds spacers which create obstacles to fluid flow. The spacers serve a number of important purposes. In the real nuclear reactor, the spacer holds a fuel rod in the fuel rod bundle. Another important function of the spacer is to influence the flow field characteristics, especially turbulence size, by the shape of the spacer. The value of the turbulence regulates the intensity of heat transfer between the fuel rod and the fluid. Therefore, it is very important to provide a correct description and analysis of the flow field behind the obstacle the spacer generates. The paper further looks into the solution of the same task using numerical simulation. The solution of this task consisted of setting the suitable boundary conditions and of setting the turbulence model for the numerical simulation. The result is a comparison of the flow field characteristics from the experimental measurement and the findings of the numerical simulation. The numerical simulation was carried out using commercial CFD software package, FLUENT.

  9. A Rationale for Going Back to the Future: Use of Disposable Spacers for Pressurised Metered Dose Inhalers

    Directory of Open Access Journals (Sweden)

    Mark Sanders

    2015-01-01

    Full Text Available The introduction of pressurised metered dose inhalers (MDIs in the mid-1950s completely transformed respiratory treatment. Despite decades of availability and healthcare support and development of teaching aids and devices to promote better use, poor pMDI user technique remains a persistent issue. The main pMDI user aid is the spacer/valved holding chamber (VHC device. Spacer/chamber features (size, shape, configuration, construction material, and hygiene considerations can vie with clinical effectiveness (to deliver the same dose as a correctly used pMDI, user convenience, cost, and accessibility. Unsurprisingly, improvised, low-cost alternatives (plastic drink bottles, paper cups, and paper towel rolls have been pressed into seemingly effective service. A UK law change permitting schools to hold emergency inhalers and spacers has prompted a development project to design a low-cost, user-friendly, disposable, and recyclable spacer. This paper spacer requires neither preuse priming nor washing, and has demonstrated reproducible lung delivery of salbutamol sulphate pMDI, comparable to an industry-standard VHC, an alternative paperboard VHC, and pMDI alone. This new device appears to perform better than these other VHC devices at the low flow rates thought achievable by paediatric patients. The data suggest that this disposable spacer may have a place in the single-use emergency setting.

  10. Metallic stent placement for the management of acute colorectal obstruction caused by colorectal carcinomas: its effect on scheduled surgery

    International Nuclear Information System (INIS)

    Cao Yan; Liu Bingyan; Mao Aiwu; Yin Xiang; Gao Zhongdu

    2011-01-01

    Objective: To prospectively evaluate the safety and clinical efficacy of a newly designed self-expandable metallic stent (SEMS) placement in the treatment of patients with acute malignant colorectal obstruction due to colorectal carcinomas. Methods: During the period from April 2001 to October 2007, a total of 52 patients with acute malignant colorectal obstruction were treated with stent placement by using a new designed SEMS, which was employed as a preoperative transit means. All the patients were followed up and the relevant data, including technical success rate, clinical efficacy, complications and overall survival rate, were documented. The results were analyzed. Results: Stent placement was successfully carried out in all patients except for two patients who showed complete colorectal obstruction. No procedure-related complications occurred. Technical success rate was 96% (50/52). Two days after the treatment, the relief rate of colorectal obstruction was 98% (49/50). Postoperative complications included stent migration (n=4), anal pain (n=2) and stool impaction (n=1). The stool impaction seen in one patient was successfully removed away with endoscopic manipulation two days after stent placement. An elective one-stage surgical procedure was performed in all 50 patients who successfully received a SEMS placement within a mean interval of (8±2) days (ranged 4-11 days) after stent placement. Mean follow-up time was (36±12) months with a range of (3-70) months. All patients remained alive at the time of this report. Conclusion: The newly designed SEMS placement used as a preoperative transit means is a safe and effective intervention for colonic decompression in patients with acute malignant colorectal obstruction due to colorectal carcinomas. It can reliably ensure most of patients with colorectal carcinomas to successfully accomplish an elective surgery. (authors)

  11. Special considerations for placement of an inflatable penile prosthesis for the patient with Peyronie's disease: techniques and patient preference

    Directory of Open Access Journals (Sweden)

    Lyons MD

    2015-07-01

    Full Text Available Matthew D Lyons, Culley C Carson III, Robert M Coward Department of Urology, University of North Carolina, Chapel Hill, NC, USA Abstract: Placement of an inflatable penile prosthesis (IPP is the mainstay of surgical treatment for patients with Peyronie's disease (PD and concomitant medication-refractory erectile dysfunction. Special considerations and adjunctive surgical techniques during the IPP procedure are often required for patients with PD to improve residual penile curvature, as well as postoperative penile length. The surgical outcomes and various adjunctive techniques are not significantly different from one another, and selection of the appropriate technique must be tailored to patient-specific factors including the extent of the deformity, the degree of penile shortening, and preoperative patient expectations. The aims of this review were to assess the current literature on published outcomes and surgical techniques involving IPP placement in the treatment of PD. Patient satisfaction and preferences are reported, along with the description and patient selection for surgical techniques that include manual penile modeling, management of refractory curvature with concurrent plication, and correction of severe residual curvature and penile shortening with tunica release and plaque incision and grafting. A thorough description of the available techniques and their associated outcomes may help guide surgeons to the most appropriate choice for their patients. Keywords: Peyronie's disease, outcomes, inflatable penile prosthesis, patient expectation, patient satisfaction 

  12. Immediate Implant Placement After Removal of Maxillary Impacted Canine Teeth: A Technical Note.

    Science.gov (United States)

    Demarosi, Federica; Varoni, Elena; Rimondini, Lia; Carrassi, Antonio; Leghissa, Giulio Cesare

    2016-01-01

    Impacted maxillary canine teeth commonly occur in the general population. The traditional therapeutic approach comprises fenestration and orthodontic traction; however, if traction is not feasible or the patient refuses orthodontic treatment, an alternative solution is to remove the impacted tooth and immediately place an implant. This technical note describes a novel surgical approach to rehabilitation after impacted canine tooth removal, entailing immediate placement of a long implant in combination with regenerative materials and a barrier. Of note, this procedure preserves the apical ridge bone crest, allowing implant anchorage and primary stability to be achieved.

  13. Planned and unplanned terminations of foster care placements in the Netherlands: Relationships with characteristics of foster children and foster placements

    NARCIS (Netherlands)

    van Rooij, F.; Maaskant, A.; Weijers, I.; Weijers, D.; Hermanns, J.

    2015-01-01

    This study examined the role of placement and child characteristics in the unplanned termination of foster placements. Data were used from 169 foster children aged 0 to 20. Results showed that 35% of all foster placement terminations were unplanned. Outcomes of logistic regression analyses

  14. Effect of epilepsy magnetic source imaging on intracranial electrode placement

    Science.gov (United States)

    Knowlton, Robert C.; Razdan, Shantanu N.; Limdi, Nita; Elgavish, Rotem A.; Killen, Jeff; Blount, Jeffrey; Burneo, Jorge G.; Ver Hoef, Lawrence; Paige, Lebron; Faught, Edward; Kankirawatana, Pongkiat; Bartolucci, Al; Riley, Kristen; Kuzniecky, Ruben

    2009-01-01

    Objective Intracranial electroencephalography (ICEEG) with chronically implanted electrodes is a costly invasive diagnostic procedure that remains necessary for a large proportion of patients who undergo evaluation for epilepsy surgery. This study was designed to evaluate whether magnetic source imaging (MSI), a non-invasive test based on magnetoencephalography source localization, can supplement ICEEG by affecting electrode placement to improve sampling of the seizure onset zone(s). Methods Of 298 consecutive epilepsy surgery candidates (between 2001-2006) 160 cases were prospectively enrolled on the basis of insufficient localization from seizure monitoring and MRI results. Prior to presenting MSI results, decisions were made as to whether to proceed with ICEEG, and if so, where to place electrodes such that the hypothetical seizure onset zone would be sampled. MSI results were then provided with allowance of changes to the original plan. Results MSI indicated additional electrode coverage in 18 of 77 (23%) ICEEG cases. In 39% percent (95% CI: 16.4, 61.4) seizure onset ICEEG patterns involved the additional electrodes indicated by MSI. Sixty-two patients underwent surgical resection based on ICEEG recording of seizures. Highly localized MSI was significantly associated with seizure-free outcome (mean=3.4 years, minimum > 1 year) for the entire surgical population (n=62). Interpretation MSI spike localization increases the chance that the seizure onset zone is sampled when patients undergo ICEEG for presurgical epilepsy evaluations. The clinical impact of this effect–-improving diagnostic yield of ICEEG–-should be considered in surgery candidates that do not have satisfactory indication of epilepsy localization from seizure semiology, EEG, and MRI. PMID:19557860

  15. Minimally invasive piezosurgery for a safe placement of blade dental implants in jaws with severe bone loss

    Directory of Open Access Journals (Sweden)

    F. Rossi

    2014-10-01

    Full Text Available Aim :Severe atrophies of edentulous jaws require major reconstructive bone surgery in order to allow the placement of root-form implants with standard diameter. These bone augmentation techniques represent the best option reported in the literature, but they are often rejected by patients because of their high economic and biological costs in addition to the possibility of failure in the short and/or long term. In the maxilla regenerative methods (onlay, inlay, and distraction have high success rates, whereas in the mandible, especially in the distal atrophic area, they are not so predictable. In such situations an alternative technique for fixed prosthethic rebilitation is the insertion of platform blade implants, which have their elective indication for atrophic bone ridges with reduced width, owing to their reduced thickness. The aim of this study is to assess the effectiveness of the use of piezoelectric ultrasonic handpieces, in order to simplify the placement of blade implants, making it safer and less traumatic than with conventional surgical procedures. Materials and methods: Platform blade implants are extension implant functionally and aesthetically reliable, even if they require a more difficult surgical technique compared with the one currently in use for screw implants. A minimally invasive procedure by means of piezosurgery that was performed on 142 subjects is presented and a case is reported which highlights the successful results. Results: and conclusion The use of piezoelectric ultrasonic handpieces simplifies the surgical procedure for the placement of blade implant, making it safer and less traumatic.

  16. Ultrasonography for confirmation of gastric tube placement.

    Science.gov (United States)

    Tsujimoto, Hiraku; Tsujimoto, Yasushi; Nakata, Yukihiko; Akazawa, Mai; Kataoka, Yuki

    2017-04-17

    Gastric tubes are commonly used for the administration of drugs and tube feeding for people who are unable to swallow. Feeding via a tube misplaced in the trachea can result in severe pneumonia. Therefore, the confirmation of tube placement in the stomach after tube insertion is important. Recent studies have reported that ultrasonography provides good diagnostic accuracy estimates in the confirmation of appropriate tube placement. Hence, ultrasound could provide a promising alternative to X-rays in the confirmation of tube placement, especially in settings where X-ray facilities are unavailable or difficult to access. To assess the diagnostic accuracy of ultrasound for gastric tube placement confirmation. We searched the Cochrane Library (2016, Issue 3), MEDLINE (to March 2016), Embase (to March 2016), National Institute for Health Research (NIHR) PROSPERO Register (to May 2016), Aggressive Research Intelligence Facility Databases (to May 2016), ClinicalTrials.gov (to May 2016), ISRCTN registry (May 2016), World Health Organization International Clinical Trials Registry Platform (to May 2016) and reference lists of articles, and contacted study authors. We included studies that evaluated the diagnostic accuracy of naso- and orogastric tube placement confirmed by ultrasound visualization using X-ray visualization as the reference standard. We included cross-sectional studies, and case-control studies. We excluded case series or case reports. Studies were excluded if X-ray visualization was not the reference standard or if the tube being placed was a gastrostomy or enteric tube. Two review authors independently assessed the risk of bias and extracted data from each of the included studies. We contacted authors of the included studies to obtain missing data. We identified 10 studies (545 participants and 560 tube insertions) which met our inclusion criteria.No study was assigned low risk of bias or low concern in every QUADAS-2 domain. We judged only three (30

  17. Stent graft placement for dysfunctional arteriovenous grafts

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, College of Medicine, CHA University, Seongnam (Korea, Republic of); Shin, Byung Seok; Ohm, Joon Young; Ahn, Moon Sang [Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2015-07-15

    This study aimed to evaluate the usefulness and outcomes of stent graft use in dysfunctional arteriovenous grafts. Eleven patients who underwent stent graft placement for a dysfunctional hemodialysis graft were included in this retrospective study. Expanded polytetrafluoroethylene covered stent grafts were placed at the venous anastomosis site in case of pseudoaneurysm, venous laceration, elastic recoil or residual restenosis despite the repeated angioplasty. The patency of the arteriovenous graft was evaluated using Kaplan-Meier analysis. Primary and secondary mean patency was 363 days and 741 days. Primary patency at 3, 6, and 12 months was 82%, 73%, and 32%, respectively. Secondary patency at the 3, 6, 12, 24, and 36 months was improved to 91%, 82%, 82%, 50%, and 25%, respectively. Fractures of the stent graft were observed in 2 patients, but had no effect on the patency. Stent graft placement in dysfunctional arteriovenous graft is useful and effective in prolonging graft patency.

  18. VLSI Cells Placement Using the Neural Networks

    International Nuclear Information System (INIS)

    Azizi, Hacene; Zouaoui, Lamri; Mokhnache, Salah

    2008-01-01

    The artificial neural networks have been studied for several years. Their effectiveness makes it possible to expect high performances. The privileged fields of these techniques remain the recognition and classification. Various applications of optimization are also studied under the angle of the artificial neural networks. They make it possible to apply distributed heuristic algorithms. In this article, a solution to placement problem of the various cells at the time of the realization of an integrated circuit is proposed by using the KOHONEN network

  19. Placement Strategies of World's Top Business Schools

    OpenAIRE

    Varun Shenoy; Aithal P. S .

    2017-01-01

    Institutional Ranking in higher education space has become a very important practice and management institutions across the world are greatly profited by the published global rankings based on various criterions. The ranking is usually publicized depending upon Institutional infrastructure, their employment &placements, teaching pedagogy, research output, faculty-student ratio, international linkage, application of technology in teaching –learning process etc. In this study, we have chosen to...

  20. A Placement Model for Flight Simulators.

    Science.gov (United States)

    1982-09-01

    simulator basing strategies. Captains David R. VanDenburg and Jon D. Veith developed a mathematical model to assist in the placement analysis of A-7...Institute for Defense Analysis, Arlington VA, August 1977. AD A049979. 23. Sugarman , Robert C., Steven L. Johnson, and William F. H. Ring. "B-I Systems...USAF Cost and Plan- nin& Factors. AFR 173-13. Washington: Govern- ment Printing Office, I February 1982. * 30. Van Denburg, Captain David R., USAF

  1. Easy Suprapubic Tube Placement Using a Van Buren Sound.

    Science.gov (United States)

    Wyner, Lawrence M

    2018-01-17

    To place a suprapubic tube without using specialized instruments. Suprapubic cystostomy is a straightforward urological procedure, which nevertheless may become complicated if the equipment needed to perform the operation is unavailable. Nowadays, in most operating rooms, control of urological instruments has been taken away from a small cadre of dedicated urology nurses, and instead is delegated to a central sterilization department or is even outsourced, leading to an increased rate of instrument misplacement or breakage. Disposable kits are useful, but may not be stocked at all facilities. Hence, the tools needed by the urologist to perform suprapubic cystostomy may not be readily available when they are needed. This reality was the impetus for the development of the following technique for suprapubic tube placement, which relies only upon ordinary instruments. A simple method is described for placing a suprapubic catheter using a curved Van Buren sound, a cystoscope, and a minor surgical set. Not only is the operation is easy to do, but is also advantageous in that the catheter may be exchanged over a wire, if necessary, before the establishment of a suprapubic tract. The technique depends on the presence of an intact urethra; therefore, it is contraindicated in the setting of pelvic trauma. This suprapubic cystostomy method may be used either as a primary technique or as a back-up procedure if the urologist's preferred instrumentation is not available. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. FPGA Congestion-Driven Placement Refinement

    Energy Technology Data Exchange (ETDEWEB)

    Vicente de, J.

    2005-07-01

    The routing congestion usually limits the complete proficiency of the FPGA logic resources. A key question can be formulated regarding the benefits of estimating the congestion at placement stage. In the last years, it is gaining acceptance the idea of a detailed placement taking into account congestion. In this paper, we resort to the Thermodynamic Simulated Annealing (TSA) algorithm to perform a congestion-driven placement refinement on the top of the common Bounding-Box pre optimized solution. The adaptive properties of TSA allow the search to preserve the solution quality of the pre optimized solution while improving other fine-grain objectives. Regarding the cost function two approaches have been considered. In the first one Expected Occupation (EO), a detailed probabilistic model to account for channel congestion is evaluated. We show that in spite of the minute detail of EO, the inherent uncertainty of this probabilistic model impedes to relieve congestion beyond the sole application of the Bounding-Box cost function. In the second approach we resort to the fast Rectilinear Steiner Regions algorithm to perform not an estimation but a measurement of the global routing congestion. This second strategy allows us to successfully reduce the requested channel width for a set of benchmark circuits with respect to the widespread Versatile Place and Route (VPR) tool. (Author) 31 refs.

  3. Experiences of Supervision at Practice Placement Sites

    Directory of Open Access Journals (Sweden)

    Lesley Diack

    2014-01-01

    Full Text Available Background. Whilst placement supervision and clinical education programmes are of significant value in shaping the behaviours of undergraduate healthcare students, appropriate provisions which are efficacious to the learner are somewhat lacking, particularly for students studying on UK MPharm programmes. Objectives. To explore and explain the value of placement supervision to the personal development and employability of undergraduate pharmacy students. Methods. Students participated in a week long community pharmacy pilot programme, a result of a collaborative effort between the School of Pharmacy and Life Sciences and a small consortium of community pharmacies. Students and stakeholders were asked to evaluate their experiences via separate questionnaires which had been developed to elicit views and attitudes. Key Findings. Feedback from students and stakeholders towards the experience was overwhelmingly positive with multiple benefits being reported. Of particular prominence was the emphasis in student feedback on the value of placement supervision to their professional and personal development. Findings were indicative of a development in clinical practice proficiencies, core skills, and improvement in decision-making practice. Conclusions. The benefits of clinical supervision to the professional and personal development of MPharm students are well documented, although attracting professional pharmacy supervisors is proving a problematic task for educational providers in the UK.

  4. Can donated media placements reach intended audiences?

    Science.gov (United States)

    Cooper, Crystale Purvis; Gelb, Cynthia A; Chu, Jennifer; Polonec, Lindsey

    2013-09-01

    Donated media placements for public service announcements (PSAs) can be difficult to secure, and may not always reach intended audiences. Strategies used by the Centers for Disease Control and Prevention's (CDC) Screen for Life: National Colorectal Cancer Action Campaign (SFL) to obtain donated media placements include producing a diverse mix of high-quality PSAs, co-branding with state and tribal health agencies, securing celebrity involvement, monitoring media trends to identify new distribution opportunities, and strategically timing the release of PSAs. To investigate open-ended recall of PSAs promoting colorectal cancer screening, CDC conducted 12 focus groups in three U.S. cities with men and women either nearing age 50 years, when screening is recommended to begin, or aged 50-75 years who were not in compliance with screening guidelines. In most focus groups, multiple participants recalled exposure to PSAs promoting colorectal cancer screening, and most of these individuals reported having seen SFL PSAs on television, in transit stations, or on the sides of public buses. Some participants reported exposure to SFL PSAs without prompting from the moderator, as they explained how they learned about the disease. Several participants reported learning key campaign messages from PSAs, including that colorectal cancer screening should begin at age 50 years and screening can find polyps so they can be removed before becoming cancerous. Donated media placements can reach and educate mass audiences, including millions of U.S. adults who have not been screened appropriately for colorectal cancer.

  5. Perioperative management for the prevention of bacterial infection in cardiac implantable electronic device placement

    Directory of Open Access Journals (Sweden)

    Katsuhiko Imai

    2016-08-01

    Full Text Available Cardiac implantable electronic devices (CIEDs have become important in the treatment of cardiac disease and placement rates increased significantly in the last decade. However, despite the use of appropriate antimicrobial prophylaxis, CIED infection rates are increasing disproportionately to the implantation rate. CIED infection often requires explantation of all hardware, and at times results in death. Surgical site infection (SSI is the most common cause of CIED infection as a pocket infection. The best method of combating CIED infection is prevention. Prevention of CIED infections comprises three phases: before, during, and after device implantation. The most critical factors in the prevention of SSIs are detailed operative techniques including the practice of proper technique by the surgeon and surgical team.

  6. Angioplasty and stent placement - carotid artery

    Science.gov (United States)

    ... How to read food labels Low-salt diet Mediterranean diet Surgical wound care - open Images Atherosclerosis of internal carotid artery Carotid stenosis, x-ray of the right artery Cholesterol producers References Amarenco P, Labreuche ...

  7. Deriving DICOM surgical extensions from surgical workflows

    Science.gov (United States)

    Burgert, O.; Neumuth, T.; Gessat, M.; Jacobs, S.; Lemke, H. U.

    2007-03-01

    The generation, storage, transfer, and representation of image data in radiology are standardized by DICOM. To cover the needs of image guided surgery or computer assisted surgery in general one needs to handle patient information besides image data. A large number of objects must be defined in DICOM to address the needs of surgery. We propose an analysis process based on Surgical Workflows that helps to identify these objects together with use cases and requirements motivating for their specification. As the first result we confirmed the need for the specification of representation and transfer of geometric models. The analysis of Surgical Workflows has shown that geometric models are widely used to represent planned procedure steps, surgical tools, anatomical structures, or prosthesis in the context of surgical planning, image guided surgery, augmented reality, and simulation. By now, the models are stored and transferred in several file formats bare of contextual information. The standardization of data types including contextual information and specifications for handling of geometric models allows a broader usage of such models. This paper explains the specification process leading to Geometry Mesh Service Object Pair classes. This process can be a template for the definition of further DICOM classes.

  8. Back-to-basics with a surgical rotation programme.

    Science.gov (United States)

    Hall, Catherine L

    This article describes the development and implementation of a rotation programme for Band 5 nurses within the surgical directorate at Heart of England NHS Foundation Trust. The article highlights the challenges raised for nurses with health service modernization and develops the rationale for the need for a different way of thinking. At Heart of England NHS Foundation Trust, the authors evaluation has led to the development of the surgical rotation programme for Band 5 nurses. This rotation programme challenged basic clinical practice and traditional modes of staff placement. Indications, so far, are that quality of care for patients has improved and nurses satisfaction has increased as a result of the implementation of the Band 5 surgical rotation programme.

  9. Combat surgical workload in Operation Iraqi Freedom and Operation Enduring Freedom: The definitive analysis.

    Science.gov (United States)

    Turner, Caryn A; Stockinger, Zsolt T; Gurney, Jennifer M

    2017-07-01

    Relatively few publications exist on surgical workload in the deployed military setting. This study analyzes US military combat surgical workload in Iraq and Afghanistan to gain a more thorough understanding of surgical training gaps and personnel requirements. A retrospective analysis of the Department of Defense Trauma Registry was performed for all Role 2 (R2) and Role 3 (R3) military treatment facilities from January 2001 to May 2016. International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes were grouped into 18 categories based on functional surgical skill sets. The 189,167 surgical procedures identified were stratified by role of care, month, and year. Percentiles were calculated for the number of procedures for each skill set. A literature search was performed for publications documenting combat surgical workload during the same period. A total of 23,548 surgical procedures were performed at R2 facilities, while 165,619 surgical procedures were performed at R3 facilities. The most common surgical procedures performed overall were soft tissue (37.5%), orthopedic (13.84%), abdominal (13.01%), and vascular (6.53%). The least common surgical procedures performed overall were cardiac (0.23%), peripheral nervous system (0.53%), and spine (0.34%).Mean surgical workload at any point in time clearly underrepresented those units in highly kinetic areas, at times by an order of magnitude or more. The published literature always demonstrated workloads well in excess of the 50th percentile for the relevant time period. The published literature on combat surgical workload represents the high end of the spectrum of deployed surgical experience. These trends in surgical workload provide vital information that can be used to determine the manpower needs of future conflicts in ever-changing operational tempo environments. Our findings provide surgical types and surgical workload requirements that will be useful in surgical training and

  10. Surgical medical record

    DEFF Research Database (Denmark)

    Bulow, S.

    2008-01-01

    A medical record is presented on the basis of selected linguistic pearls collected over the years from surgical case records Udgivelsesdato: 2008/12/15......A medical record is presented on the basis of selected linguistic pearls collected over the years from surgical case records Udgivelsesdato: 2008/12/15...

  11. Recognizing surgical patterns

    NARCIS (Netherlands)

    Bouarfa, L.

    2012-01-01

    In the Netherlands, each year over 1700 patients die from preventable surgical errors. Numerous initiatives to improve surgical practice have had some impact, but problems persist. Despite the introduction of checklists and protocols, patient safety in surgery remains a continuing challenge. This is

  12. Surgical management of pain

    African Journals Online (AJOL)

    the spinal cord.[4] In this article, the reader is referred back to this illustration to understand the surgical techniques used to manage pain. Pain is caused by ... Injured dorsal root neurons discharge at higher frequencies and more spontaneously than normally. Surgical techniques. The physician should ensure that treat-.

  13. Surgical site infections

    African Journals Online (AJOL)

    the development of SSI. Complications associated with surgical site infections7. • Longer hospital stay with risk of acquiring other hospital acquired infections like pneumonia. • Require more surgical procedures. • Risk for development of resistance to antibiotics. • Risk for development of necrotizing fasciitis with skin loss.

  14. The CRISPRdb database and tools to display CRISPRs and to generate dictionaries of spacers and repeats

    Directory of Open Access Journals (Sweden)

    Vergnaud Gilles

    2007-05-01

    Full Text Available Abstract Background In Archeae and Bacteria, the repeated elements called CRISPRs for "clustered regularly interspaced short palindromic repeats" are believed to participate in the defence against viruses. Short sequences called spacers are stored in-between repeated elements. In the current model, motifs comprising spacers and repeats may target an invading DNA and lead to its degradation through a proposed mechanism similar to RNA interference. Analysis of intra-species polymorphism shows that new motifs (one spacer and one repeated element are added in a polarised fashion. Although their principal characteristics have been described, a lot remains to be discovered on the way CRISPRs are created and evolve. As new genome sequences become available it appears necessary to develop automated scanning tools to make available CRISPRs related information and to facilitate additional investigations. Description We have produced a program, CRISPRFinder, which identifies CRISPRs and extracts the repeated and unique sequences. Using this software, a database is constructed which is automatically updated monthly from newly released genome sequences. Additional tools were created to allow the alignment of flanking sequences in search for similarities between different loci and to build dictionaries of unique sequences. To date, almost six hundred CRISPRs have been identified in 475 published genomes. Two Archeae out of thirty-seven and about half of Bacteria do not possess a CRISPR. Fine analysis of repeated sequences strongly supports the current view that new motifs are added at one end of the CRISPR adjacent to the putative promoter. Conclusion It is hoped that availability of a public database, regularly updated and which can be queried on the web will help in further dissecting and understanding CRISPR structure and flanking sequences evolution. Subsequent analyses of the intra-species CRISPR polymorphism will be facilitated by CRISPRFinder and the

  15. PairWise Neighbours database: overlaps and spacers among prokaryote genomes

    Directory of Open Access Journals (Sweden)

    Garcia-Vallvé Santiago

    2009-06-01

    Full Text Available Abstract Background Although prokaryotes live in a variety of habitats and possess different metabolic and genomic complexity, they have several genomic architectural features in common. The overlapping genes are a common feature of the prokaryote genomes. The overlapping lengths tend to be short because as the overlaps become longer they have more risk of deleterious mutations. The spacers between genes tend to be short too because of the tendency to reduce the non coding DNA among prokaryotes. However they must be long enough to maintain essential regulatory signals such as the Shine-Dalgarno (SD sequence, which is responsible of an efficient translation. Description PairWise Neighbours is an interactive and intuitive database used for retrieving information about the spacers and overlapping genes among bacterial and archaeal genomes. It contains 1,956,294 gene pairs from 678 fully sequenced prokaryote genomes and is freely available at the URL http://genomes.urv.cat/pwneigh. This database provides information about the overlaps and their conservation across species. Furthermore, it allows the wide analysis of the intergenic regions providing useful information such as the location and strength of the SD sequence. Conclusion There are experiments and bioinformatic analysis that rely on correct annotations of the initiation site. Therefore, a database that studies the overlaps and spacers among prokaryotes appears to be desirable. PairWise Neighbours database permits the reliability analysis of the overlapping structures and the study of the SD presence and location among the adjacent genes, which may help to check the annotation of the initiation sites.

  16. Optimization of an organic photovoltaic device via modulation of thickness of photoactive and optical spacer layers.

    Science.gov (United States)

    Li, Qi; Yoon, Won Jung; Ju, Heongkyu

    2014-01-01

    We examine the modulation effects of thicknesses of both a photoactive layer (a bulk-heterojunction (BHJ) of poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM)) and an optical spacer of a transparent metal oxide, for power conversion efficiency optimization of organic photovoltaic devices. The redistribution of the optical intensity at the photoactive layer via the thickness modulation of both layers is taken into account, to produce three-dimensional (3D) plots as a function of both layer thicknesses of 0 to 400 nm range (5 nm step), for the device efficiency optimization. The modulation pattern of absorption is produced in the 3D plot as scanning the thicknesses of both layers as a result of modulation of interference between incoming and reflected light, which can be secured by changing the effective optical path length between two electrodes of a photovoltaic device. It is also seen that the case of inserting the spacer of the higher refractive index demands finer adjustment of the spacer layer thickness to achieve the optimum device efficiency. In addition, the series resistance of the photoactive layer of the thickness range of 0 to 70 nm is taken into account to provide the 3D plots as a function of the scanned thicknesses of both layers. Inclusion of the series resistance of the photoactive layer, which is also the function of its thickness, in the simulation, indicates that the series resistance can influence qualitatively the dependence of power conversion efficiency (PCE) on the thicknesses of both layers. We also find that minimization of series resistance, e.g., by device annealing, allows not only the relevant voltage to increase but also the optimum thickness of the photoactive layer to increase, leading to more absorption of light.

  17. Diversity in a Polymicrobial Community Revealed by Analysis of Viromes, Endolysins and CRISPR Spacers.

    Directory of Open Access Journals (Sweden)

    Michelle Davison

    Full Text Available The polymicrobial biofilm communities in Mushroom and Octopus Spring in Yellowstone National Park (YNP are well characterized, yet little is known about the phage populations. Dominant species, Synechococcus sp. JA-2-3B'a(2-13, Synechococcus sp. JA-3-3Ab, Chloroflexus sp. Y-400-fl, and Roseiflexus sp. RS-1, contain multiple CRISPR-Cas arrays, suggesting complex interactions with phage predators. To analyze phage populations from Octopus Spring biofilms, we sequenced a viral enriched fraction. To assemble and analyze phage metagenomic data, we developed a custom module, VIRITAS, implemented within the MetAMOS framework. This module bins contigs into groups based on tetranucleotide frequencies and CRISPR spacer-protospacer matching and ORF calling. Using this pipeline we were able to assemble phage sequences into contigs and bin them into three clusters that corroborated with their potential host range. The virome contained 52,348 predicted ORFs; some were clearly phage-like; 9319 ORFs had a recognizable Pfam domain while the rest were hypothetical. Of the recognized domains with CRISPR spacer matches, was the phage endolysin used by lytic phage to disrupt cells. Analysis of the endolysins present in the thermophilic cyanophage contigs revealed a subset of characterized endolysins as well as a Glyco_hydro_108 (PF05838 domain not previously associated with sequenced cyanophages. A search for CRISPR spacer matches to all identified phage endolysins demonstrated that a majority of endolysin domains were targets. This strategy provides a general way to link host and phage as endolysins are known to be widely distributed in bacteriophage. Endolysins can also provide information about host cell wall composition and have the additional potential to be used as targets for novel therapeutics.

  18. Percutaneous transluminal angioplasty and stent placement for iliofemoral arterial atherosclerotic occlusive disease

    International Nuclear Information System (INIS)

    Zheng Yanbo; Jiang Wenjin; Liu Sheng; Song Xuepeng; Sheng Qirui

    2006-01-01

    Objectives: To assess the safety and efficacy of percutaneous transluminal angioplasty (PTA) and stent placement for the treatment of iliofemoral arterial atherosclerotic occlusive diseases. Methods From April 1999 to August 2004, 13 cases of iliofemoral arterial occlusions were recanalized with contact thrombolytic therapy combined with guide wire mechanical recanalization method, followed by angioplasty and stent placement. A total of 25 self-expanding Wallstents were deployed. All patients were followed up by means of duplex ultrasound, angiography, or both. Results: All 13 cases were successfully recanalized, with technical successful rate of 100%. Available follow-up for all patients from 8 months-5 years (mean 26.2 months) included one patient undergoing again with successful contact thrombolysis because of early thrombosis; another patient with recurrent symptoms at 19 month after operation undertaking surgical bypass because of later reocclusion; all of the rest stents showing patency by the end of the study. Conclusions: Contact thrombolysis combined with guide wire mechanical recanalization for iliofemoral arterial occlusion is safe and effective, whereas PTA and stent placement would have the nearly same efficacy for the disease with mild injury and low restenosis. (authors)

  19. Modal properties of the flexural vibrating package of rods linked by spacer grids

    Directory of Open Access Journals (Sweden)

    Zeman V.

    2011-06-01

    Full Text Available The paper deals with the modelling and modal analysis of the large package of identical parallel rods linked by transverse springs (spacer grids placed on several level spacings. The rod discretization by finite element method is based on Rayleigh beam theory. For the cyclic and central symmetric package of rods (such as fuel rods in nuclear fuel assembly the system decomposition on the identical revolved rod segments was applied. A modal synthesis method with condensation is used for modelling of the whole system. The presented method is the first step for modelling the nuclear fuel assembly vibration caused by excitation determined by the support plate motion of the reactor core.

  20. Development of a manufacturing process for Zr-based spacer grid materials

    International Nuclear Information System (INIS)

    Jung, Yang-Il; Lee, Myung-Ho; Choi, Byoung-Kwon; Park, Jeong-Yong; Jeong, Yong-Hwan

    2009-01-01

    A novel manufacturing process for zirconium-based alloy strips has been developed. This process consists of a prior heat-treatment under a monotectoid temperature before subsequent deformation processes. During the prior heat-treatment process at 580 deg. C for 10 h, β-Nb phase particles were precipitated. The second phase particles stabilized the alloy from corrosion even the subsequent annealings at high temperatures. This result enhances the manufacturability of zirconium-based alloys, especially for high strength alloys with high Nb contents. The process developed can also be applied to commercial zirconium-based spacer grid materials, which would give rise to a higher producibility of such materials.

  1. Influence of the boundary conditions on heat and mass transfer in spacer-filled channels

    Science.gov (United States)

    Ciofalo, M.; La Cerva, M. F.; Di Liberto, M.; Tamburini, A.

    2017-11-01

    The purpose of this study is to discuss some problems which arise in heat or mass transfer in complex channels, with special reference to the spacer-filled channels adopted in membrane processes. Among the issues addressed are the consistent definition of local and mean heat or mass transfer coefficients; the influence of the wall boundary conditions; the influence of one-side versus two-side heat/mass transfer. Most of the results discussed were obtained by finite volume CFD simulations concerning heat transfer in Membrane Distillation or mass transfer in Electrodialysis and Reverse Electrodialysis, but many of the conclusions apply also to different processes involving geometrically complex channels

  2. Placement of subcutaneous ureteral bypasses without fluoroscopic guidance in cats with ureteral obstruction: 19 cases (2014-2016).

    Science.gov (United States)

    Livet, Véronique; Pillard, Paul; Goy-Thollot, Isabelle; Maleca, David; Cabon, Quentin; Remy, Denise; Fau, Didier; Viguier, Éric; Pouzot, Céline; Carozzo, Claude; Cachon, Thibaut

    2017-10-01

    Objectives The purpose of this study was to describe the perioperative and postoperative complications as well as short-term and long-term outcomes in cats with ureteral obstructions treated by placement of a subcutaneous ureteral bypass (SUB) device without imaging control. The second objective of this study was to compare cats treated by SUB device with cats treated by traditional surgical intervention. Methods Data were obtained retrospectively from the medical records (2014-2016) of cats that underwent SUB placement (SUB cats) and cats that underwent traditional ureteral surgery (C cats). Results Nineteen SUB devices were placed without fluoroscopic, radiographic or ultrasonographic guidance in 13 cats. Fifteen traditional interventions (ureterotomy and neoureterocystostomy) were performed in 11 cats. Successful placement of the SUB device was achieved in all cats with only one major intraoperative complication (kinking of the kidney catheter) and one minor intraoperative complication (misplacement of the kidney catheter). Eleven SUB cats recovered from the surgical procedure; two SUB cats and three C cats died during the anaesthesia recovery period. Postoperative SUB complications included anaemia (n = 2), urinary tract infection (UTI) (n = 4), non-infectious cystitis (n = 5) and SUB device obstruction (n = 1). Postoperative traditional surgery complications included anaemia (n = 7), UTIs (n = 6), non-infectious cystitis (n = 1), re-obstruction (n = 4) and ureteral stricture (n = 1). Median postoperative duration of hospitalisation (3 days) was significantly shorter for SUB cats than for C cats ( P = 0.013). Ten SUB cats (76.9%) and four C cats (40%) were still alive at a median follow-up of 225 days and 260 days, respectively. Owners were completely (90%) or mostly (10%) satisfied with the SUB device placement. Conclusions and relevance SUB device placement appears to be an effective and safe option for treating ureteral obstruction in cats, and this study

  3. FROM BRAND PLACEMENT TO TOURISM PRODUCT PLACEMENT. FICTION SERIES AS PROMOTIONAL SUPPORT OF SPANISH TOURISM DESTINATIONS

    Directory of Open Access Journals (Sweden)

    Noelia Araújo-Vila

    2011-12-01

    Full Text Available Every day more consumers spend much of their free time to the consumption of audiovisual series, which is reflected in the notable increase in downloads and audiences. Therefore, many sectors have decided to use audiovisual series as advertising (brand placement, being one of them the tourism sector (tourism product placement. There are many worldwide destinations that have decided to set in a fiction series, thus being viewed by thousands of spectators, which has resulted in increases in visitors. In the Spanish case is not so clear the use of this strategy, as it is analysed in this article.

  4. Computer-guided implant placement for rehabilitation of the edentulous maxilla with two impacted canines: an approach without extraction of the impacted teeth.

    Science.gov (United States)

    Mazor, Ziv; Segal, Philip; Levin, Liran

    2015-01-01

    The aim of this report was to suggest an alternative approach to avoid impacted canine extraction by utilizing computer-guided implant placement for providing an implant adjacent to the impacted canine without contact to the impacted tooth. In cases when the adjacent area is available for implant placement, a computerized three-dimensional (3D) planning system can be used to place implants in a way that avoids the impacted canine. Tilted implants could be used to achieve the proper support for implant-supported fixed dentures without damaging the impacted teeth. Following careful 3D planning, a computer-derived surgical stent is used to guide the surgical placement of the implants in the proper place. Since the position of the implants is known prior to the surgical procedure, a prefabricated provisional restoration is delivered immediately at the end of the surgery. Following a waiting period of 6 months, the implant-supported definitive restoration is fabricated using the same technique and delivered to the patient, making sure that proper maintenance and oral home care hygiene are feasible. This suggested treatment modality, when suitable, could provide a relatively short treatment time, a less invasive procedure, and fewer potential complications compared to the extraction of an impacted canine, massive bone grafting, and implant placement. Also, it might be assumed that the use of the native bone, as suggested here, rather than an augmented bone could lead to better long-term results.

  5. Implant placement and provisionalization in extraction, edentulous, and sinus grafted sites: a clinical report on 1,500 sites.

    Science.gov (United States)

    Petrungaro, Paul S

    2005-12-01

    The incorporation of restorative procedures at implant placement and the creation of natural emergence profiles and lifelike ceramic restorations have become the focus of implantology. Recent publications have provided guidelines for success with the immediate restoration procedure, and have presented basic surgical protocols for the implant team. Enhancement of the healing phase through the local delivery of growth factors to the surgical site, as well as through advancements in bone grafting materials, has allowed implant surgeons to accomplish multiple surgical procedures during the initial surgical visit. In addition, advancements in surgical stent designs have allowed the restorative dentist to adequately communicate to the surgeon, during surgery, the parameters required in the final restoration to replace the natural tooth system with form, function, and esthetics. This article presents the results of more than 1,500 immediate restored implants placed in edentulous sites, fresh extraction sockets, and sinus grafted sites. Also highlighted are guidelines for surgical success, as well as a description of a surgical stent design that communicates requirements for restorative success to the surgeon, while also serving as an esthetic provisional restoration.

  6. Comparative study of the contribution of various PWR spacer grid components to hydrodynamic and wall pressure characteristics

    International Nuclear Information System (INIS)

    Bhattacharjee, Saptarshi; Ricciardi, Guillaume; Viazzo, Stéphane

    2017-01-01

    Highlights: • Complex geometry inside a PWR fuel assembly is simulated using simplified 3D models. • Structured meshes are generated as far as possible. • Fluctuating hydrodynamic and wall pressure field are analyzed using LES. • Comparative studies between square spacer grid, circular spacer grid and mixing vanes are presented. • Simulations are compared with experimental data. - Abstract: Flow-induced vibrations in a pressurized water reactor (PWR) core can cause fretting wear in fuel rods. These vibrations can compromise safety of a nuclear reactor. So, it is necessary to know the random fluctuating forces acting on the rods which cause these vibrations. In this paper, simplified 3D models like square spacer grid, circular spacer grid and symmetric mixing vanes have been used inside an annular pipe. Hydrodynamic and wall pressure characteristics are evaluated using large eddy simulations (LES). Structured meshes are generated as far as possible. Simulations are compared with an experiment. Results show that the grid and vanes have a combined effect: grid accelerates the flow whereas the vanes contribute to the swirl structures. Spectral analysis of the simulations illustrate vortex shedding phenomenon in the wake of spacer grids. This initial study opens up interesting perspectives towards improving the modeling strategy and understanding the complex phenomenon inside a PWR core.

  7. Comparative study of the contribution of various PWR spacer grid components to hydrodynamic and wall pressure characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Saptarshi, E-mail: saptarshi.bhattacharjee@outlook.com [Alternative Energies and Atomic Energy Commission (CEA) – Cadarache, DEN/DTN/STCP/LHC, 13108 Saint Paul lez Durance Cedex (France); Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), UMR7340 CNRS, Aix-Marseille Université, Centrale Marseille, 13451 Marseille Cedex (France); Ricciardi, Guillaume [Alternative Energies and Atomic Energy Commission (CEA) – Cadarache, DEN/DTN/STCP/LHC, 13108 Saint Paul lez Durance Cedex (France); Viazzo, Stéphane [Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), UMR7340 CNRS, Aix-Marseille Université, Centrale Marseille, 13451 Marseille Cedex (France)

    2017-06-15

    Highlights: • Complex geometry inside a PWR fuel assembly is simulated using simplified 3D models. • Structured meshes are generated as far as possible. • Fluctuating hydrodynamic and wall pressure field are analyzed using LES. • Comparative studies between square spacer grid, circular spacer grid and mixing vanes are presented. • Simulations are compared with experimental data. - Abstract: Flow-induced vibrations in a pressurized water reactor (PWR) core can cause fretting wear in fuel rods. These vibrations can compromise safety of a nuclear reactor. So, it is necessary to know the random fluctuating forces acting on the rods which cause these vibrations. In this paper, simplified 3D models like square spacer grid, circular spacer grid and symmetric mixing vanes have been used inside an annular pipe. Hydrodynamic and wall pressure characteristics are evaluated using large eddy simulations (LES). Structured meshes are generated as far as possible. Simulations are compared with an experiment. Results show that the grid and vanes have a combined effect: grid accelerates the flow whereas the vanes contribute to the swirl structures. Spectral analysis of the simulations illustrate vortex shedding phenomenon in the wake of spacer grids. This initial study opens up interesting perspectives towards improving the modeling strategy and understanding the complex phenomenon inside a PWR core.

  8. Anti-cas spacers in orphan CRISPR4 arrays prevent uptake of active CRISPR-Cas I-F systems.

    Science.gov (United States)

    Almendros, Cristóbal; Guzmán, Noemí M; García-Martínez, Jesús; Mojica, Francisco J M

    2016-06-06

    Archaea and bacteria harbour clustered regularly interspaced short palindromic repeats (CRISPR) loci. These arrays encode RNA molecules (crRNA), each containing a sequence of a single repeat-intervening spacer. The crRNAs guide CRISPR-associated (Cas) proteins to cleave nucleic acids complementary to the crRNA spacer, thus interfering with targeted foreign elements. Notably, pre-existing spacers may trigger the acquisition of new spacers from the target molecule by means of a primed adaptation mechanism. Here, we show that naturally occurring orphan CRISPR arrays that contain spacers matching sequences of the cognate (absent) cas genes are able to elicit both primed adaptation and direct interference against genetic elements carrying those genes. Our findings show the existence of an anti-cas mechanism that prevents the transfer of a fully equipped CRISPR-Cas system. Hence, they suggest that CRISPR immunity may be undesired by particular prokaryotes, potentially because they could limit possibilities for gaining favourable sequences by lateral transfer.

  9. The Construction of Chimeric T-Cell Receptor with Spacer Base of Modeling Study of VHH and MUC1 Interaction

    Directory of Open Access Journals (Sweden)

    Nazanin Pirooznia

    2011-01-01

    Full Text Available Adaptive cell immunotherapy with the use of chimeric receptors leads to the best and most specific response against tumors. Chimeric receptors consist of a signaling fragment, extracellular spacer, costimulating domain, and an antibody. Antibodies cause immunogenicity; therefore, VHH is a good replacement for ScFv in chimeric receptors. Since peptide sequences have an influence on chimeric receptors, the effect of peptide domains on each other's conformation were investigated. CD3Zeta, CD28, VHH and CD8α, and FcgIIα are used as signaling moieties, costimulating domain, antibody, and spacers, respectively. To investigate the influence of the ligation of spacers on the conformational structure of VHH, models of VHH were constructed. Molecular dynamics simulation was run to study the influence of the presence of spacers on the conformational changes in the binding sites of VHH. Root mean square deviation and root mean square fluctuation of critical segments in the binding site showed no noticeable differences with those in the native VHH. Results from molecular docking revealed that the presence of spacer FcgIIα causes an increasing effect on VHH with MUC1 interaction. Each of the constructs was transformed into the Jurkat E6.1. Expression analysis and evaluation of their functions were examined. The results showed good expression and function.

  10. Sequences in the intergenic spacer influence RNA Pol I transcription from the human rRNA promoter

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.M.; Sylvester, J.E. [Hahnemann Univ., Philadelphia, PA (United States)

    1994-09-01

    In most eucaryotic species, ribosomal genes are tandemly repeated about 100-5000 times per haploid genome. The 43 Kb human rDNA repeat consists of a 13 Kb coding region for the 18S, 5.8S, 28S ribosomal RNAs (rRNAs) and transcribed spacers separated by a 30 Kb intergenic spacer. For species such as frog, mouse and rat, sequences in the intergenic spacer other than the gene promoter have been shown to modulate transcription of the ribosomal gene. These sequences are spacer promoters, enhancers and the terminator for spacer transcription. We are addressing whether the human ribosomal gene promoter is similarly influenced. In-vitro transcription run-off assays have revealed that the 4.5 kb region (CBE), directly upstream of the gene promoter, has cis-stimulation and trans-competition properties. This suggests that the CBE fragment contains an enhancer(s) for ribosomal gene transcription. Further experiments have shown that a fragment ({approximately}1.6 kb) within the CBE fragment also has trans-competition function. Deletion subclones of this region are being tested to delineate the exact sequences responsible for these modulating activities. Previous sequence analysis and functional studies have revealed that CBE contains regions of DNA capable of adopting alternative structures such as bent DNA, Z-DNA, and triple-stranded DNA. Whether these structures are required for modulating transcription remains to be determined as does the specific DNA-protein interaction involved.

  11. Same-Day Evaluation and Surgery for Otitis Media and Tympanostomy Tube Placement: A Feasibility Study.

    Science.gov (United States)

    Billings, Kathleen R; Hajduk, John; Rose, Allison; De Oliveira, Gildasio S; Suresh, Suresh S; Thompson, Dana M

    2016-10-01

    To determine the feasibility of providing streamlined same-day evaluation and surgical management of children with recurrent otitis media or chronic serous otitis media who meet criteria for tympanostomy tube (TT) placement. Retrospective matched case series. Tertiary care children's hospital. A comparison group (age, sex, insurance product) was utilized to determine if the same-day process decreased facility time and surgical time for the care episode. A parent satisfaction survey was administered. Thirty children, with a median age of 16 months (range, 12-22 months), participated in the same-day surgery process for TT. Twenty-one patients (70.0%) were male, and these patients were matched to a comparison group (similar age, sex, and insurance product) having non-same-day (routine) TT placement. The same-day patients spent significantly less time in clinic for the preoperative physician visit (average, 15 minutes) when compared with the non-same-day patients (average, 51.5 minutes; P otitis media. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  12. A novel 3-dimensional electromagnetic guidance system increases intraoperative microwave antenna placement accuracy.

    Science.gov (United States)

    Sastry, Amit V; Swet, Jacob H; Murphy, Keith J; Baker, Erin H; Vrochides, Dionisios; Martinie, John B; McKillop, Iain H; Iannitti, David A

    2017-12-01

    Failure to locate lesions and accurately place microwave antennas can lead to incomplete tumor ablation. The Emprint™ SX Ablation Platform employs real-time 3D-electromagnetic spatial antenna tracking to generate intraoperative laparoscopic antenna guidance. We sought to determine whether Emprint™ SX affected time/accuracy of antenna-placement in a laparoscopic training model. Targets (7-10 mm) were set in agar within a laparoscopic training device. Novices (no surgical experience), intermediates (surgical residents), and experts (HPB-surgeons) were asked to locate and hit targets using a MWA antenna (10-ultrasound only, 10-Emprint™ SX). Time to locate target, number of attempts to hit the target, first-time hit rate, and time from initiating antenna advance to hitting the target were measured. Participants located 100% of targets using ultrasound, with experts taking significantly less time than novices and intermediates. Using ultrasound only, successful hit-rates were 70% for novices and 90% for intermediates and experts. Using Emprint™ SX, successful hit rates for all 3-groups were 100%, with significantly increased first-time hit-rates and reduced time required to hit targets compared to ultrasound only. Emprint™ SX significantly improved accuracy and speed of antenna-placement independent of experience, and was particularly beneficial for novice users. Copyright © 2017 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

  13. Advanced Esthetic Management of Dental Implants: Surgical and Restorative Considerations to Improve Outcomes.

    Science.gov (United States)

    Levin, Barry P; Rubinstein, Sergio; Rose, Louis F

    2015-01-01

    Successful dental implant therapy in the maxillary anterior dentition requires meticulous attention to surgical and prosthodontic measures. Proper diagnosis, extraction technique, implant selection, and placement significantly impact outcomes. Respect of hard and soft tissue physiology following tooth loss and implant placement requires specific steps be taken. Management tissue contours properly, via regenerative therapy, results in successful framing of the restoration. Provisionalization and definitive restorative therapy also impacts the level of esthetic success. The contours of the temporary abutment and crown develop soft tissue contours for the final restoration. Overcontouring can lead to soft tissue recession and mucosal asymmetry. Design of the definitive crown(s) is crucial for long-term maintenance of esthetically acceptable results. Visualizing the outcome of treatment prior to its inception, following specific surgical and restorative guidelines, increases the likelihood of success. This article demonstrates the importance of proper surgical and prosthetic principles in achieving esthetic implant results. © 2015 Wiley Periodicals, Inc.

  14. Effective conflict resolution strategies for SRAF placement

    Science.gov (United States)

    Ganjugunte, Shashidhara K.; Strecker, Norbert; Jayaram, Srividya; LaCour, Pat; Torunoglu, Ilhami

    2015-07-01

    Sub-Resolution Assist Features (SRAFs) have emerged as a key technology to enable semiconductor manufacturing for advanced technology nodes. SRAF placement is required to adhere to manufacturability constraints (MRC). MRC specifications are distance and size constraints specified by the user to ensure SRAFs are not detrimental to the final target shapes being printed. Conceptually, SRAF placement can be divided into two steps - SRAF candidate generation and SRAF candidate cleanup or conflict resolution. SRAFs generated as candidates may not adhere to MRC constraints. It is during the cleanup/conflict resolution process that the MRC constraints are enforced. In this paper we focus on the latter phase - cleanup. The goal of the cleanup phase is to retain as much of the initial candidates as possible, and, if necessary, transform them to adhere to MRC conditions. An SRAF is said to be in conflict with another shape if it violates the distance MRC constraint. One can model these conflicts using a conflict graph G=(V,E), whose vertices V correspond to geometric shapes involved in a conflict and an edge is present in E, between two vertices if the corresponding shapes are involved in a conflict. A weight is associated with each vertex that could, for example, correspond to area of the corresponding shape. The goal of conflict resolution then, is to find a transformation of the vertices so that the resulting graph is conflict free while maximizing the weight of vertices retained. This can be viewed as a generalization of the computationally hard problem of finding the largest independent set of candidates, albeit allowing for transformation. The transformations we allow include deletion, splitting, resizing, merge, and bounded translation. In this paper, we describe an approach which classifies the conflicts and apply appropriate transformations to achieve effective SRAF placement. Further, we demonstrate that such a strategy reduces the number of rules to be specified by

  15. Design and Application of a Novel Patient-Specific Three-Dimensional Printed Drill Navigational Guiding in Atlantoaxial Pedicle Screw Placement.

    Science.gov (United States)

    Pu, Xinwei; Yin, Mengchen; Ma, Junming; Liu, Yujie; Chen, Guanghui; Huang, Quan; Zhao, Guoquan; Lu, Tingsheng; Yao, Shudan; Chen, Qinlin; Luo, Chunshan

    2017-12-11

    To explore accuracy and clinical efficacy of a novel patient-specific three-dimensional (3D) printed drill navigational guiding template in atlantoaxial pedicle screw placement. A retrospective analysis of 49 patients with atlantoaxial vertebral fractures and dislocations was performed. Patients were divided into a 3D printed navigational guiding template group (n = 25) and traditional group (n = 14). Safety of screw position was assessed, and accuracy of 2 screw placement methods was compared. Accuracy of screw placement was assessed by comparing differences between preoperative designed channel transverse angle and postoperative actual screw placement angle. Two groups were compared to find differences between operative time, intraoperative blood loss, screw placement time, number of fluoroscopy examinations, visual analog scale score, and Japanese Orthopaedic Association score. There were statistically significant differences between the guiding template group and traditional group in operative time, intraoperative blood loss, screw placement time, and number of fluoroscopy examinations. No statistically significant differences were found between groups in transverse and sagittal angles with ideal values. There were statistically significant differences between preoperative and 1-week, 1-month, 3-month, 6-month, and 1-year postoperative visual analog scale and Japanese Orthopaedic Association scores in the same group, whereas there were no statistically significant differences between the groups. Use of the novel patient-specific 3D printed drill navigational guiding template in surgical treatment of atlantoaxial fracture and dislocation can improve accuracy of pedicle screw placement and safety of the surgery, can reduce surgical risks, and can obtain satisfactory clinical curative effects. Copyright © 2017. Published by Elsevier Inc.

  16. Post-placement temperature reduction techniques

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    2010-01-01

    With technology scaled to deep submicron era, temperature and temperature gradient have emerged as important design criteria. We propose two post-placement techniques to reduce peak temperature by intelligently allocating whitespace in the hotspots. Both methods are fully compliant with commercial...... technologies, and can be easily integrated with state-of-the-art thermal-aware design flow. Experiments in a set of tests on circuits implemented in STM 65nm technologies show that our methods achieve better peak temperature reduction than directly increasing circuit's area....

  17. New strategy for optimizing wavelength converter placement

    Science.gov (United States)

    Foo, Y. C.; Chien, S. F.; Low, Andy L. Y.; Teo, C. F.; Lee, Youngseok

    2005-01-01

    This paper proposes a new strategic alternate-path routing to be combined with the particle swarm optimization (PSO) algorithm to better solve the wavelength converters placement problem. The strategic search heuristic is designed to provide network connectivity topologies for the converters to be placed more effectively. The new strategy is applied to the 14-node NSFNET to examine its efficiency in reducing the blocking probability in sparse wavelength conversion network. Computed results show that, when applied to the identical optimization framework, our search method outperforms both the equal-cost multipath routing and traffic-engineering-aware shortest-path routing.

  18. Surgical ethics: surgical virtue and more.

    Science.gov (United States)

    Vercler, Christian J

    2015-01-01

    The encounter between a patient and her surgeon is unique for several reasons. The surgeon inflicts pain upon a patient for the patient's own good. An operative intervention is irreducibly personal, such that the decisions about and performance of operations are inseparable from the idiosyncrasies of the individual surgeon. Furthermore, there is a chasm of knowledge between the patient and surgeon that is difficult to cross. Hence, training in the discipline of surgery includes the inculcation of certain virtues and practices to safeguard against abuses of this relationship and to make sure that the best interests of the patient are prioritized. The stories in this issue are evidence that in contemporary practice this is not quite enough, as surgeons reflect on instances they felt were ethically challenging. Common themes include the difficulty in communicating surgical uncertainty, patient-surgeon relationships, ethical issues in surgical training, and the impact of the technological imperative on caring for dying patients.

  19. Preoperative short hookwire placement for small pulmonary lesions: evaluation of technical success and risk factors for initial placement failure.

    Science.gov (United States)

    Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Masaoka, Yoshihisa; Tanaka, Takashi; Sato, Takuya; Gobara, Hideo; Toyooka, Shinichi; Kanazawa, Susumu

    2018-05-01

    To retrospectively evaluate the technical success of computed tomography fluoroscopy-guided short hookwire placement before video-assisted thoracoscopic surgery and to identify the risk factors for initial placement failure. In total, 401 short hookwire placements for 401 lesions (mean diameter 9.3 mm) were reviewed. Technical success was defined as correct positioning of the hookwire. Possible risk factors for initial placement failure (i.e., requirement for placement of an additional hookwire or to abort the attempt) were evaluated using logistic regression analysis for all procedures, and for procedures performed via the conventional route separately. Of the 401 initial placements, 383 were successful and 18 failed. Short hookwires were finally placed for 399 of 401 lesions (99.5%). Univariate logistic regression analyses revealed that in all 401 procedures only the transfissural approach was a significant independent predictor of initial placement failure (odds ratio, OR, 15.326; 95% confidence interval, CI, 5.429-43.267; p failure (OR 0.793, 95% CI 0.631-0.996; p = 0.046). The technical success of preoperative short hookwire placement was extremely high. The transfissural approach was a predictor initial placement failure for all procedures and small lesion size was a predictor of initial placement failure for procedures performed via the conventional route. • Technical success of preoperative short hookwire placement was extremely high. • The transfissural approach was a significant independent predictor of initial placement failure for all procedures. • Small lesion size was a significant independent predictor of initial placement failure for procedures performed via the conventional route.

  20. Sonographic Identification of Tube Thoracostomy Study (SITTS: Confirmation of Intrathoracic Placement

    Directory of Open Access Journals (Sweden)

    Jamie A. Jenkins

    2012-09-01

    Full Text Available Introduction: Thoracostomy tubes (TT are commonly placed in the management of surgical, emergency, and trauma patients and chest radiographs (CXR and computed tomography (CT are performed to confirm placement. Ultrasound (US has not previously been used as a means to confirm intrathoracic placement of chest tubes. This study involves a novel application of US to demonstrate chest tubes passing through the pleural line, thus confirming intrathoracic placement.Methods: This was an observational proof-of-concept study using a convenience sample of patients with TTs at a tertiary-care university hospital. Bedside US was performed by the primary investigatorusing first the low-frequency (5–1 MHz followed by the high-frequency (10–5 MHz transducers, in both 2-dimensional gray-scale and M-modes in a uniform manner. The TTs were identified in transverse and longitudinal views by starting at the skin entry point and scanning to where the TT passed the pleural line, entering the intrathoracic region. All US images were reviewed by US fellowship-trained emergency physicians. CXRs and CTs were used as the standard for confirmation ofTT placement.Results: Seventeen patients with a total of 21 TTs were enrolled. TTs were visualized entering the intrathoracic space in 100% of cases. They were subjectively best visualized with the high-frequency (10–5 MHz linear transducer. Sixteen TTs were evaluated using M-mode. TTs produced a distinct pattern on M-mode.Conclusion: Bedside US can visualize the TT and its entrance into the thoracic cavity and it can distinguish it from the pleural line by a characteristic M-mode pattern. This is best visualized with the high-frequency (10–5 MHz linear transducer. [West J Emerg Med. 2012;13(4:305–311.

  1. 45S rDNA external transcribed spacer organization reveals new phylogenetic relationships in Avena genus.

    Science.gov (United States)

    Rodrigues, Joana; Viegas, Wanda; Silva, Manuela

    2017-01-01

    The genus Avena comprises four distinct genomes organized in diploid (AA or CC), tetraploid (AABB or AACC) and hexaploid species (AACCDD), constituting an interesting model for phylogenetic analysis. The aim of this work was to characterize 45S rDNA intergenic spacer (IGS) variability in distinct species representative of Avena genome diversity-A. strigosa (AA), A. ventricosa (CvCv), A. eriantha (CpCp), A. barbata (AABB), A. murphyi (AACC), A. sativa (AACCDD) and A. sterilis (AACCDD) through the assessment of the 5' external transcribed spacer (5'-ETS), a promising IGS region for phylogenetic studies poorly studied in Avena genus. In this work, IGS length polymorphisms were detected mainly due to distinct 5'-ETS sequence types resulting from major differences in the number and organization of repeated motifs. Although species with A genome revealed a 5'-ETS organization (A-organization) similar to the one previously described in A. sativa, a distinct organization was unraveled in C genome diploid species (C-organization). Interestingly, such new organization presents a higher similarity with other Poaceae species than A-genome sequences, supporting the hypothesis of C-genome being the ancestral Avena genome. Additionally, polyploid species with both genomes mainly retain the A-genome 5'-ETS organization, confirming the preferential elimination of C-genome sequences in Avena polyploid species. Moreover, 5'-ETS sequences phylogenetic analysis consistently clustered the species studied according to ploidy and genomic constitution supporting the use of ribosomal genes to highlight Avena species evolutive pathways.

  2. Cationic gemini surfactants with cleavable spacer: chemical hydrolysis, biodegradation, and toxicity.

    Science.gov (United States)

    Tehrani-Bagha, A R; Holmberg, K; van Ginkel, C G; Kean, M

    2015-07-01

    The paper describes synthesis and characterization of a new type of cationic gemini surfactant, which has dodecyl tails and a spacer that contains an ester bond. The nomenclature used to describe the structure is 12Q2OCO1Q12, with Q being a quaternary ammonium group and the numbers indicating the number of methylene or methyl groups. Due to the close proximity to the two quaternary ammonium groups, the ester bond is very stable on the acid side and very labile already at slightly alkaline conditions. The hydrolysis products are two single chain surfactants (i.e. 12Q2OH and 12Q1COOH) which are less surface active than the intact gemini surfactant. 12Q2OCO1Q12 was found to be readily biodegradable, i.e. it gave more than 60% biodegradation after 28 days. This is interesting because similar gemini surfactants but with ester bonds in the tails instead of the spacer, have previously been found not to be readily biodegradable. The gemini surfactant was found to be toxic to aquatic organisms (ErC50 value of 0.27 mg/l), although less toxic than the two hydrolysis products. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Role of spacer length in interaction between novel gemini imidazolium surfactants and Rhizopus oryzae lipase.

    Science.gov (United States)

    Adak, Sunita; Datta, Sougata; Bhattacharya, Santanu; Banerjee, Rintu

    2015-11-01

    An insight into the effects of new ionic liquid-type gemini imidazolium cationic surfactants on the structure and function of the lipases is of prime importance for their potential application. Changes in the activity, stability and structure of Rhizopus oryzae lipase in the presence of novel gemini surfactants, [C16-3-C16im]Br2 and [C16-12-C16im]Br2 were probed in the present study. Surfactant with shorter spacer length, [C16-3-C16im]Br2 was found to be better in improving the hydrolytic activity and thermal stability of the lipase. For both the surfactants, activation was concentration dependent. CD spectroscopy results showed a decrease in α-helix and an increase in β-sheet content in the presence of these surfactants. A higher structural change observed in presence of [C16-12-C16im]Br2 correlated with lower enzyme activity. Isothermal titration calorimetric studies showed the binding to be spontaneous in nature based on sequential two site binding model. The forces involved in binding were found to differ for the two surfactants proving that the spacer length is an important factor which governs the interaction. These surfactants could be used as promising components both in enzyme modification and media engineering for attaining the desired goals in biocatalytic reactions. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The intergenic spacer region of the rDNA in Haplopappus gracilis (Nutt.) Gray.

    Science.gov (United States)

    Ruffini Castiglione, M; Gelati, M T; Cremonini, R; Frediani, M

    2013-06-01

    In this paper, we provide further information on the genome organisation of Haplopappus gracilis, one of the six angiosperms showing the lowest chromosome number, i.e. 2n = 4, by determining the nucleotide sequence of the intergenic spacer region of the ribosomal RNA genes and its cytological localization on metaphase chromosomes. DNA sequence analysis reveals the occurring of a product of 4,382 bp in length, characterised by the presence of four blocks of different repeated sequences. Our analysis also evidenced putative promoter regions with three transcription initiation sites for polymerase I, as previously reported in Artemisia absinthium, belonging to the same Asteraceae family. A fluorescent in situ hybridization with the intergenic spacer probe indicates the presence of rDNA genes only in the satellited chromosomes of H. gracilis; besides, differences in the signal intensity between homologous chromosomes were frequently observed, thus suggesting for these chromosome sites the presence of a variable number of rDNA gene copies, even if a divergent chromatin organisation in corresponding regions cannot be ruled out.

  5. A Pilot Study of Augmented Reality Technology Applied to the Acetabular Cup Placement During Total Hip Arthroplasty.

    Science.gov (United States)

    Ogawa, Hiroyuki; Hasegawa, Seiichirou; Tsukada, Sachiyuki; Matsubara, Masaaki

    2018-02-05

    We developed an acetabular cup placement device, the AR-HIP system, using augmented reality (AR). The AR-HIP system allows the surgeon to view an acetabular cup image superimposed in the surgical field through a smartphone. The smartphone also shows the placement angle of the acetabular cup. This preliminary study was performed to assess the accuracy of the AR-HIP system for acetabular cup placement during total hip arthroplasty (THA). We prospectively measured the placement angles using both a goniometer and AR-HIP system in 56 hips of 54 patients undergoing primary THA. We randomly determined the order of intraoperative measurement using the 2 devices. At 3 months after THA, the placement angle of the acetabular cup was measured on computed tomography images. The primary outcome was the absolute value of the difference between intraoperative and postoperative computed tomography measurements. The measurement angle using AR-HIP was significantly more accurate in terms of radiographic anteversion than that using a goniometer (2.7° vs 6.8°, respectively; mean difference 4.1°; 95% confidence interval, 3.0-5.2; P < .0001). There was no statistically significant difference in terms of radiographic inclination (2.1° vs 2.6°; mean difference 0.5°; 95% confidence interval, -1.1 to 0.1; P = .13). In this pilot study, the AR-HIP system provided more accurate information regarding acetabular cup placement angle than the conventional method. Further studies are required to confirm the utility of the AR-HIP system as a navigation tool. Copyright © 2018. Published by Elsevier Inc.

  6. A comparison C1-C2 transarticular screw placement after self-education and mentored education of orthopaedic residents.

    Science.gov (United States)

    Kirkpatrick, John S

    2012-08-01

    Prospective randomized trial. This study will provide preliminary data on whether residents can be "self-taught" and to what extent a lecture, demonstration, and coaching can improve skills and knowledge. Practice-based learning is an essential competency in Accreditation Council for graduate Medical Education-accredited residencies. Little has been done to demonstrate whether residents can be self-taught or benefit from mentoring in understanding and performing difficult surgical tasks. A written test was given to orthopedic residents on C1-C2 transarticular screw placement. They were then provided reading on C1-C2 transarticular screw placement. Residents were then divided into a "self-directed learning" group and a "mentored learning" group. All residents then performed the technique on models, with the "mentored" group receiving a lecture and coaching from the mentor. The models were analyzed for technique errors and the previous test was administered again as a posttest. The test and screw placement were repeated 4 months later. Residents without mentoring had an average improvement of 4.5 points, those with mentoring had average improvement of 8.6 points (P=0.0068). The screw placement technique error rate for the nonmentored group (n=8) was 2.55, and for the mentored group (n=9) was 1.47 (P=0.004). Sixteen residents completed the delayed test, 7 from the nonmentored groups and 8 from the mentored group. Nine residents were able to repeat the screw placement technique 4 months after the initial test and screw placement, 3 nonentored, and 6 mentored. Although there were some trends toward the mentored group having better retention, neither knowledge nor skill was statistically different. This preliminary trial seems to indicate that residents provided a lecture and guided technical instruction will obtain knowledge and perform procedures better than those that do not. Conclusions based upon Post Graduate year, motivation, and interest in spine surgery could

  7. Simple and surgical exodontia.

    Science.gov (United States)

    DeBowes, Linda J

    2005-07-01

    Preemptive and postoperative pain management is part of patient care when performing extractions. Simple extractions can become complicated when tooth roots are fractured. Adequate lighting,magnification, and surgical techniques are important when per-forming surgical (complicated) extractions. Radiographs should be taken before extractions and also during the procedure to assist with difficult extractions. Adequate flap design and bone removal are necessary when performing surgical extractions. Complications, including ocular trauma, jaw fracture, and soft tissue trauma, are avoided or minimized with proper patient selection and technique.

  8. Immediate placement of endosseous implants into the extraction sockets

    Directory of Open Access Journals (Sweden)

    Vijay Ebenezer

    2015-01-01

    Full Text Available Implant by definition "means any object or material, such as an alloplastic substance or other tissue, which is partial or completely inserted into the body for therapeutic, diagnostic, prosthetic, or experimental purpose." The placement of a dental implant in an extraction socket at the time of extraction or explantation is known as immediate implant placement whereas delayed placement of implant signifies the implant placement in edentulous areas where healing has completed with new bone formation after the loss of tooth/teeth. Recent idea goes by "why late when it can be done immediately." There are several advantages of immediate placement of implants, and lots of studies have been done. In this article, the advantages and disadvantages of immediate versus delayed placement of implants have been reviewed.

  9. Immediate placement of endosseous implants into the extraction sockets.

    Science.gov (United States)

    Ebenezer, Vijay; Balakrishnan, K; Asir, R Vigil Dev; Sragunar, Banu

    2015-04-01

    Implant by definition "means any object or material, such as an alloplastic substance or other tissue, which is partial or completely inserted into the body for therapeutic, diagnostic, prosthetic, or experimental purpose." The placement of a dental implant in an extraction socket at the time of extraction or explantation is known as immediate implant placement whereas delayed placement of implant signifies the implant placement in edentulous areas where healing has completed with new bone formation after the loss of tooth/teeth. Recent idea goes by "why late when it can be done immediately." There are several advantages of immediate placement of implants, and lots of studies have been done. In this article, the advantages and disadvantages of immediate versus delayed placement of implants have been reviewed.

  10. Two-stage revision of septic knee prosthesis with articulating knee spacers yields better infection eradication rate than one-stage or two-stage revision with static spacers.

    Science.gov (United States)

    Romanò, C L; Gala, L; Logoluso, N; Romanò, D; Drago, L

    2012-12-01

    The best method for treating chronic periprosthetic knee infection remains controversial. Randomized, comparative studies on treatment modalities are lacking. This systematic review of the literature compares the infection eradication rate after two-stage versus one-stage revision and static versus articulating spacers in two-stage procedures. We reviewed full-text papers and those with an abstract in English published from 1966 through 2011 that reported the success rate of infection eradication after one-stage or two-stage revision with two different types of spacers. In all, 6 original articles reporting the results after one-stage knee exchange arthoplasty (n = 204) and 38 papers reporting on two-stage revision (n = 1,421) were reviewed. The average success rate in the eradication of infection was 89.8% after a two-stage revision and 81.9% after a one-stage procedure at a mean follow-up of 44.7 and 40.7 months, respectively. The average infection eradication rate after a two-stage procedure was slightly, although significantly, higher when an articulating spacer rather than a static spacer was used (91.2 versus 87%). The methodological limitations of this study and the heterogeneous material in the studies reviewed notwithstanding, this systematic review shows that, on average, a two-stage procedure is associated with a higher rate of eradication of infection than one-stage revision for septic knee prosthesis and that articulating spacers are associated with a lower recurrence of infection than static spacers at a comparable mean duration of follow-up. IV.

  11. Evaluation of surgically placed gastrojejunostomy feeding tubes in critically ill dogs.

    Science.gov (United States)

    Cavanaugh, Ryan P; Kovak, Janet R; Fischetti, Anthony J; Barton, Linda J; Bergman, Philip

    2008-02-01

    To evaluate complications and outcomes associated with surgical placement of gastrojejunostomy feeding tubes in dogs with naturally occurring disease. Prospective study. 26 dogs. Multiple preoperative, intraoperative, and postoperative variables were evaluated. Daily postoperative abdominal radiographic examinations were performed to determine the presence of the following mechanical tube complications: kinking, coiling, knotting, and migration. Tube stoma abnormalities (erythema, cellulitis, and discharge) were observed daily and recorded by use of a standardized visual analog grading scale. Additionally, presence of complications was compared with median survival times. The most common indication for gastrojejunostomy tube placement was gastrointestinal disease (n = 11), with confirmed septic peritonitis in 8 of 11 dogs. Other indications for gastrojejunostomy tube placement included extrahepatic biliary surgery (n = 6) and pancreatic disease (9). Mean +/- SD surgical time required for tube placement was 26 +/- 14 minutes. Overall, mechanical tube complication rate was 46% (12/26), including coiling (7), migration (4), and kinking (2). Overall minor tube stoma complication rate was 77% (20/26) and included erythema (16), cellulitis (13), and discharge (17). Dislodgement or self-induced tube trauma resulted in accidental tube removal in 2 of 26 dogs, and inadvertent tube damage necessitated premature removal by the clinician in 1 of 26 dogs. Kaplan-Meier median survival time was 39 days with 13 of 26 dogs still alive. Gastrojejunostomy tube placement affords flexibility in the postoperative nutritional regimen by allowing for postgastric feeding with simultaneous access to the stomach.

  12. Surgical technique for permanent intracoelomic radiotransmitter placement in Anegada iguanas (Cyclura pinguis).

    Science.gov (United States)

    Ferrell, Shannon T; Marlar, Annajane B; Alberts, Allison C; Young, Lee A; Bradley, Kelly; Hurlbut, Sandra L; Lung, Nancy P

    2005-12-01

    Twenty-four juvenile to subadult Anegada iguanas (Cyclura pinguis), captive-reared in a propagation facility, were designated by a coordinated recovery program for release in the summer of 2003. To facilitate postrelease monitoring, a radiotransmitter device was placed within the coelomic cavity of each animal under general anesthesia before release. The equipment sterilization technique and the method of attachment of the transmitters to the coelomic body wall resulted in functional transmitters and acceptably low rates of mortality associated with the procedure.

  13. Closure Using a Surgical Closure Device of Inadvertent Subclavian Artery Punctures During Central Venous Catheter Placement

    International Nuclear Information System (INIS)

    Berlet, Matthew H.; Steffen, Diana; Shaughness, George; Hanner, James

    2001-01-01

    Severe complications can and do occur when central venous catheters are inadvertently placed into subclavian arteries. Two cases are discussed that describe how these inadvertent arterial punctures can be closed using the Perclose device (Abbott Laboratories, Redwood City, CA, USA)

  14. Re-mind the gap! Insertion - deletion data reveal neglected phylogenetic potential of the nuclear ribosomal internal transcribed spacer (ITS of fungi.

    Directory of Open Access Journals (Sweden)

    László G Nagy

    Full Text Available Rapidly evolving, indel-rich phylogenetic markers play a pivotal role in our understanding of the relationships at multiple levels of the tree of life. There is extensive evidence that indels provide conserved phylogenetic signal, however, the range of phylogenetic depths for which gaps retain tree signal has not been investigated in detail. Here we address this question using the fungal internal transcribed spacer (ITS, which is central in many phylogenetic studies, molecular ecology, detection and identification of pathogenic and non-pathogenic species. ITS is repeatedly criticized for indel-induced alignment problems and the lack of phylogenetic resolution above species level, although these have not been critically investigated. In this study, we examined whether the inclusion of gap characters in the analyses shifts the phylogenetic utility of ITS alignments towards earlier divergences. By re-analyzing 115 published fungal ITS alignments, we found that indels are slightly more conserved than nucleotide substitutions, and when included in phylogenetic analyses, improved the resolution and branch support of phylogenies across an array of taxonomic ranges and extended the resolving power of ITS towards earlier nodes of phylogenetic trees. Our results reconcile previous contradicting evidence for the effects of data exclusion: in the case of more sophisticated indel placement, the exclusion of indel-rich regions from the analyses results in a loss of tree resolution, whereas in the case of simpler alignment methods, the exclusion of gapped sites improves it. Although the empirical datasets do not provide to measure alignment accuracy objectively, our results for the ITS region are consistent with previous simulations studies alignment algorithms. We suggest that sophisticated alignment algorithms and the inclusion of indels make the ITS region and potentially other rapidly evolving indel-rich loci valuable sources of phylogenetic information

  15. Phylogeny and biogeography of Allium (Amaryllidaceae: Allieae) based on nuclear ribosomal internal transcribed spacer and chloroplast rps16 sequences, focusing on the inclusion of species endemic to China.

    Science.gov (United States)

    Li, Qin-Qin; Zhou, Song-Dong; He, Xing-Jin; Yu, Yan; Zhang, Yu-Cheng; Wei, Xian-Qin

    2010-11-01

    The genus Allium comprises more than 800 species, placing it among the largest monocotyledonous genera. It is a variable group that is spread widely across the Holarctic region. Previous studies of Allium have been useful in identifying and assessing its evolutionary lineages. However, there are still many gaps in our knowledge of infrageneric taxonomy and evolution of Allium. Further understanding of its phylogeny and biogeography will be achieved only through continued phylogenetic studies, especially of those species endemic to China that have often been excluded from previous analyses. Earlier molecular studies have shown that Chinese Allium is not monophyletic, so the goal of the present study was to infer the phylogeny and biogeography of Allium and to provide a classification of Chinese Allium by placement of Chinese species in the context of the entire phylogeny. Phylogenetic studies were based on sequence data of the nuclear ribosomal internal transcribed spacer (ITS) and chloroplast rps16 intron, analysed using parsimony and Bayesian approaches. Biogeographical patterns were conducted using statistical dispersal-vicariance analysis (S-DIVA). Phylogenetic analyses indicate that Allium is monophyletic and consists of three major clades. Optimal reconstructions have favoured the ancestors of Amerallium, Anguinum, Vvedenskya, Porphyroprason and Melanocrommyum as originating in eastern Asia. Phylogenetic analyses reveal that Allium is monophyletic but that some subgenera are not. The large genetic distances imply that Allium is of ancient origin. Molecular data suggest that its evolution proceeded along three separate evolutionary lines. S-DIVA indicates that the ancestor of Amerallium, Anguinum, Vvedenskya, Porphyroprason and Melanocrommyum originated from eastern Asia and underwent different biogeographical pathways. A taxonomic synopsis of Chinese Allium at sectional level is given, which divides Chinese Allium into 13 subgenera and 34 sections.

  16. Flow resistance of orifices and spacers of BWR thermal-hydraulic and neutronic coupling loop

    International Nuclear Information System (INIS)

    Iguchi, Tadashi; Asaka, Hideaki; Nakamura, Hideo

    2002-03-01

    Authors are performing THYNC experiments to study thermal-hydraulic instability under neutronic and thermal-hydraulic coupling. In THYNC experiments, the orifices are installed at the exit of the test section and the spacers are installed in the test section, in order to properly simulate in-core thermal-hydraulics in the reactor core. It is necessary to know the flow resistance of the orifices and spacers for the analysis of THYNC experimental results. Consequently, authors measured the flow resistance of orifice and spacer under single-phase and two-phase flows. Using the experimental results, authors investigated the dependency of the flow resistances on the parameters, such as pressure, mass flux, an geometries. Furthermore, authors investigated the applicability of the basic two-phase flow models, for example the separate flow model, to the two-phase flow multiplier. As the result of the investigation on the single-phase flow experiment, it was found (1) that the effects of pressure and mass flux flow resistance are described by a function of Reynolds number, and (2) that flow resistances of the orifice and the spacer are calculated with the previous prediction methods. However, it was necessary to introduce an empirical coefficient, since it was difficult to predict accurately the flow resistance only with the previous prediction method due to the complicated geometry dependency, for example a flow area blockage ratio. On the other hand, according to the investigation on two-phase flow experiment, the followings were found. (1) Relation between the two-phase flow multiplier and the quality is regarded to be linear under pressure of 2MPa - 7MPa. The relation is dependent on pressure and geometry, and is little dependent on mass flux. (2) Relation between the two-phase flow multiplier and void fraction is little dependent on pressure, mass flux, and geometry under pressure of 0.2MPa - 7MPa and void fraction less than 0.6. The relation is less dependent on

  17. The Re-Placement Test: Using TOEFL for Purposes of Placement

    Science.gov (United States)

    Moglen, Daniel

    2015-01-01

    This article will consider using TOEFL scores for purposes of placement and advising for international graduate students at a northern California research university. As the number of international students is on the rise and the funds for the graduate ESL program are diminishing, the way in which the university is handling the influx of…

  18. Placement suitability criteria of composite tape for mould surface in automated tape placement

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2015-10-01

    Full Text Available Automated tape placement is an important automated process used for fabrication of large composite structures in aeronautical industry. The carbon fiber composite parts realized with this process tend to replace the aluminum parts produced by high-speed machining. It is difficult to determine the appropriate width of the composite tape in automated tape placement. Wrinkling will appear in the tape if it does not suit for the mould surface. Thus, this paper deals with establishing placement suitability criteria of the composite tape for the mould surface. With the assumptions for ideal mapping and by applying some principles and theorems of differential geometry, the centerline trajectory of the composite tape is identified to follow the geodesic. The placement suitability of the composite tape is examined on three different types of non-developable mould surfaces and four criteria are derived. The developed criteria have been used to test the deposition process over several mould surfaces and the appropriate width for each mould surface is obtained by referring to these criteria.

  19. Placement Design of Changeable Message Signs on Curved Roadways

    Directory of Open Access Journals (Sweden)

    Zhongren Wang, Ph.D. P.E. T.E.

    2015-01-01

    Full Text Available This paper presented a fundamental framework for Changeable Message Sign (CMS placement design along roadways with horizontal curves. This analytical framework determines the available distance for motorists to read and react to CMS messages based on CMS character height, driver's cone of vision, CMS pixel's cone of legibility, roadway horizontal curve radius, and CMS lateral and vertical placement. Sample design charts were developed to illustrate how the analytical framework may facilitate CMS placement design.

  20. Vibrational modes and strain in GaN/AlN quantum dot stacks: dependence on spacer thickness

    Energy Technology Data Exchange (ETDEWEB)

    Fresneda, J.; Cros, A.; Llorens, J.M.; Garcia-Cristobal, A.; Cantarero, A. [Institut de Ciencia del Materials, Universitat de Valencia, 46071 Valencia (Spain); Amstatt, B.; Bellet-Amalric, E.; Daudin, B. [CEA-CNRS Group, Nanophysique et Semiconducteurs, DRFMC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France)

    2007-06-15

    We have investigated the influence of spacer thickness on the vibrational and strain characteristics of GaN/AlN quantum dot multilayers (QD). The Raman shift corresponding to the E{sub 2h} vibrational mode related to the QDs has been analyzed for AlN thicknesses ranging from 4.4 nm to 13 nm, while the amount of GaN deposited in each layer remained constant from sample to sample. It is shown that there is a rapid blue shift of the GaN vibrational mode with spacer thickness when its value is smaller than 7 nm while it remains almost constant for thicker spacers. A rapid increase of the Raman line-width in the thicker samples is also observed. The experimental behavior is discussed in comparison with the results of a theoretical model for the strain in the QDs. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Mutations in Cas9 Enhance the Rate of Acquisition of Viral Spacer Sequences during the CRISPR-Cas Immune Response.

    Science.gov (United States)

    Heler, Robert; Wright, Addison V; Vucelja, Marija; Bikard, David; Doudna, Jennifer A; Marraffini, Luciano A

    2017-01-05

    CRISPR loci and their associated (Cas) proteins encode a prokaryotic immune system that protects against viruses and plasmids. Upon infection, a low fraction of cells acquire short DNA sequences from the invader. These sequences (spacers) are integrated in between the repeats of the CRISPR locus and immunize the host against the matching invader. Spacers specify the targets of the CRISPR immune response through transcription into short RNA guides that direct Cas nucleases to the invading DNA molecules. Here we performed random mutagenesis of the RNA-guided Cas9 nuclease to look for variants that provide enhanced immunity against viral infection. We identified a mutation, I473F, that increases the rate of spacer acquisition by more than two orders of magnitude. Our results highlight the role of Cas9 during CRISPR immunization and provide a useful tool to study this rare process and develop it as a biotechnological application. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Steady-state, local temperature fields with turbulent liquid sodium flow in nominal and disturbed bundle geometries with spacer grids

    International Nuclear Information System (INIS)

    Moeller, R.; Tschoeke, H.

    1980-01-01

    The operating reliability of nuclear reactors calls for a reliable strength analysis of the highly loaded core elements, one of its prerequisites being the reliable determination of the three-dimensional velocity and temperature fields. To verify thermohydraulics computer programs, extensive local temperature measurements in the rod claddings of the critical bundle zone were performed on a heated 19-rod bundle model with sodium flow and provided with spacer grids (P/D = 1.30; W/D = 1.19). The essential results are: - Outside the spacer grids, the azimuthal temperature variations of the side and corner rods are approximately 10-fold those of rods in the central bundle zone. - The spacer grids investigated give rise to great local temperature peaks and correspondingly great temperature gradients in the axial and azimuthal directions immediately around the support points. - Continuous reduction of a subchannel by rod bowing results in substantial rises of temperature which, however, are limited to adjacent cladding tubes. (orig.)

  3. Invariance of the magnetic behavior and AMI in ferromagnetic biphase films with distinct non-magnetic metallic spacers

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.F. [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Gamino, M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Instituto de Física, Universidade Federal do Rio Grande de Sul, 91501-970 Porto Alegre, RS (Brazil); Andrade, A.M.H. de [Instituto de Física, Universidade Federal do Rio Grande de Sul, 91501-970 Porto Alegre, RS (Brazil); Vázquez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Correa, M.A. [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Bohn, F., E-mail: felipebohn@fisica.ufrn.br [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil)

    2017-02-01

    We investigate the quasi-static magnetic, magnetotransport, and dynamic magnetic properties in ferromagnetic biphase films with distinct non-magnetic metallic spacer layers. We observe that the nature of the non-magnetic metallic spacer material does not have significant influence on the overall biphase magnetic behavior, and, consequently, on the magnetotransport and dynamic magnetic responses. We focus on the magnetoimpedance effect and verify that the films present asymmetric magnetoimpedance effect. Moreover, we explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the probe current frequency in order to achieve higher sensitivity values. The invariance of the magnetic behavior and the asymmetric magnetoimpedance effect in ferromagnetic biphase films with distinct non-magnetic metallic spacers place them as promising candidates for probe element and open possibilities to the development of lower-cost high sensitivity linear magnetic field sensor devices.

  4. Multi-Scaled Modeling the Mechanical Properties of Tubular Composites Reinforced with Innovated 3D Weft Knitted Spacer Fabrics

    Science.gov (United States)

    Omrani, Elahe; Hasani, Hossein; Dibajian, Sayed Houssain

    2018-02-01

    Textile composites of 3D integrated spacer configurations have been recently focused by several researchers all over the world. In the present study, newly-designed tubular composites reinforced with 3D spacer weft knitted fabrics were considered and the effects of their structural parameters on some applicable mechanical properties were investigated. For this purpose, two different samples of 3D spacer weft knitted textile types in tubular form were produced on an electronic flat knitting machine, using glass/nylon hybrid yarns. Thermoset tubular-shaped composite parts were manufactured via vacuum infusion molding process using epoxy resin. The mechanical properties of the produced knitted composites in term of external static and internal hydrostatic pressures were evaluated. Resistance of the produced composites against the external static and internal hydrostatic pressures was numerically simulated using multi-scale modeling method. The finding revealed that there is acceptable correlation between experimental and theoretical results.

  5. Parylene C-on-photoresist (POP): a low temperature spacer scheme for polymer/metal nanowire fabrication

    International Nuclear Information System (INIS)

    Li, Yuanhui; Xie, Quan; Wang, Wei; Zhang, Hao; Lei, Yinhua; Zhang, Haixia Alice; Wu, Wengang; Li, Zhihong; Zheng, Mingxin

    2011-01-01

    This work introduced a novel spacer scheme for polymer/metal nanowire preparation by combining Parylene C and photoresist (Parylene C on photoresist, POP, process), both of which possess a low temperature fabrication essence. Adhesion between the Parylene C and the substrate with photoresist onside was improved by introducing a modified silanization pretreatment. Parylene C filled in an undercut generated by regular lithography on a dual-layered photoresist was left as nanometer-sized residues after an isotropic oxygen plasma etching. Parylene C nanowires with the minimal width down to 200 nm were successfully obtained by this POP-based spacer technique, and were then utilized as the etching mask for ion milling of the metal films beneath to realize corresponding chromium/gold nanowires. The present POP scheme will expand the application of the spacer technique in polymer/metal nanowire fabrication for integrated micro/nanoelectromechanical systems. (technical note)

  6. Advancement of a Job- and Personal- Characteristics Placement Model

    National Research Council Canada - National Science Library

    Frink, Dwight

    2001-01-01

    Research toward validation of a comprehensive model mapping personal characteristics onto differentiated job characteristics for effective placement, development, and retention of Navy personnel is described...

  7. Ambulatory Surgical Measures - Facility

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Ambulatory Surgical Center Quality Reporting (ASCQR) Program seeks to make care safer and more efficient through quality reporting. ASCs eligible for this...

  8. Ambulatory Surgical Measures - State

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Ambulatory Surgical Center Quality Reporting (ASCQR) Program seeks to make care safer and more efficient through quality reporting. ASCs eligible for this...

  9. Surgical Treatments for Fibroids

    Science.gov (United States)

    ... NICHD Research Information Find a Study More Information Preeclampsia and Eclampsia About NICHD Research Information Find a ... Treatments Share Facebook Twitter Pinterest Email Print Surgical Treatments for Fibroids If you have moderate or severe ...

  10. Ambulatory Surgical Measures - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Ambulatory Surgical Center Quality Reporting (ASCQR) Program seeks to make care safer and more efficient through quality reporting. ASCs eligible for this...

  11. [Surgical treatment of ulcer].

    Science.gov (United States)

    Ungeheuer, E; Schröder, D; Lüders, K

    1978-04-27

    The standard of today in surgical treatment of the duodenal and gastric ulcer in Germany is shown. Positive and negative aspects of the different methods are discussed. Special technics are recommended for the different types of gastroduodenal ulcera.

  12. Disruptive visions: surgical education.

    Science.gov (United States)

    Satava, R M

    2004-05-01

    Technological change, decreased financial support for medical education, and social oversight (in the form of the "To Err Is Human" report, HIPPA, and reduced work hours) are forcing a rethinking of the traditional model of surgical education to improve patient safety. New approaches to evaluating surgical competence, such as objective assessment, in combination with new technologies, such as the Internet and surgical simulators, provide the tools to effect a revolution in surgical education and training. Competency based upon quantifiable criteria measures must replace the traditional subjective assessment. The implementation requires accurately defining the elements of training, establishing new quantifiable metrics, stringently measuring performance against criterion, and reporting outcomes throughout the career of a surgeon.

  13. Surgical Critical Care Initiative

    Data.gov (United States)

    Federal Laboratory Consortium — The Surgical Critical Care Initiative (SC2i) is a USU research program established in October 2013 to develop, translate, and validate biology-driven critical care....

  14. Laparoscopic adrenalectomy: Surgical techniques

    Directory of Open Access Journals (Sweden)

    Matthew J Mellon

    2008-01-01

    Full Text Available Since its first description in 1992, laparoscopic adrenalectomy has become the gold standard for the surgical treatment of most adrenal conditions. The benefits of a minimally invasive approach to adrenal resection such as decreased hospital stay, shorter recovery time and improved patient satisfaction are widely accepted. However, as this procedure becomes more widespread, critical steps of the operation must be maintained to ensure expected outcomes and success. This article reviews the surgical techniques for the laparoscopic adrenalectomy.

  15. Diversity and Inheritance of Intergenic Spacer Sequences of 45S Ribosomal DNA among Accessions of Brassica oleracea L. var. capitata

    Directory of Open Access Journals (Sweden)

    Kiwoung Yang

    2015-12-01

    Full Text Available Ribosomal DNA (rDNA of plants is present in high copy number and shows variation between and within species in the length of the intergenic spacer (IGS. The 45S rDNA of flowering plants includes the 5.8S, 18S and 25S rDNA genes, the internal transcribed spacer (ITS1 and ITS2, and the intergenic spacer 45S-IGS (25S-18S. This study identified six different types of 45S-IGS, A to F, which at 363 bp, 1121 bp, 1717 bp, 1969 bp, 2036 bp and 2111 bp in length, respectively, were much shorter than the reported reference IGS sequences in B. oleracea var. alboglabra. The shortest two IGS types, A and B, lacked the transcription initiation site, non-transcribed spacer, and external transcribed spacer. Functional behavior of those two IGS types in relation to rRNA synthesis is a subject of further investigation. The other four IGSs had subtle variations in the transcription termination site, guanine-cytosine (GC content, and number of tandem repeats, but the external transcribed spacers of these four IGSs were quite similar in length. The 45S IGSs were found to follow Mendelian inheritance in a population of 15 F1s and their 30 inbred parental lines, which suggests that these sequences could be useful for development of new breeding tools. In addition, this study represents the first report of intra-specific (within subspecies variation of the 45S IGS in B. oleracea.

  16. Diversity and Inheritance of Intergenic Spacer Sequences of 45S Ribosomal DNA among Accessions of Brassica oleracea L. var. capitata.

    Science.gov (United States)

    Yang, Kiwoung; Robin, Arif Hasan Khan; Yi, Go-Eun; Lee, Jonghoon; Chung, Mi-Young; Yang, Tae-Jin; Nou, Ill-Sup

    2015-12-03

    Ribosomal DNA (rDNA) of plants is present in high copy number and shows variation between and within species in the length of the intergenic spacer (IGS). The 45S rDNA of flowering plants includes the 5.8S, 18S and 25S rDNA genes, the internal transcribed spacer (ITS1 and ITS2), and the intergenic spacer 45S-IGS (25S-18S). This study identified six different types of 45S-IGS, A to F, which at 363 bp, 1121 bp, 1717 bp, 1969 bp, 2036 bp and 2111 bp in length, respectively, were much shorter than the reported reference IGS sequences in B. oleracea var. alboglabra. The shortest two IGS types, A and B, lacked the transcription initiation site, non-transcribed spacer, and external transcribed spacer. Functional behavior of those two IGS types in relation to rRNA synthesis is a subject of further investigation. The other four IGSs had subtle variations in the transcription termination site, guanine-cytosine (GC) content, and number of tandem repeats, but the external transcribed spacers of these four IGSs were quite similar in length. The 45S IGSs were found to follow Mendelian inheritance in a population of 15 F₁s and their 30 inbred parental lines, which suggests that these sequences could be useful for development of new breeding tools. In addition, this study represents the first report of intra-specific (within subspecies) variation of the 45S IGS in B. oleracea.

  17. Faculty staff and rural placement supervisors' pre- and post-placement perceptions of a clinical rural placement programme in NSW Australia.

    Science.gov (United States)

    Johnson, G; Blinkhorn, A

    2013-02-01

    Staff views on a rural clinical placement involving 4th year dental undergraduates from the University of Sydney (Australia) were collected in order to monitor whether the programme was feasible and acceptable to the academic Faculty Staff and the rural clinical supervisors. An evaluation of the rural placement programme was undertaken in 2009 at three rural sites in New South Wales (Australia). Semi-structured pre- and post-placement in person interviews recorded the views of three University Faculty Staff whilst similar data were collected by telephone interviews for three supervising clinicians at the rural clinical sites. Interviews gathered opinions on the organisation, implementation and outcomes of the rural placement programme. Eight qualitative analysis identified themes were specified and included communication, programme duration, effect on students and staff, benefits of the programme, rural intentions, programme sustainability and the success of the programme. Positive pre-placement aspects were potentially good clinical experience, new environment, sharing of knowledge and interaction with a rural community. Negative issues were anxieties about students' clinical ability to offer a service, missing lectures and maintaining clinical training quotas. The post-placement themes were generally positive; staff reported that the students enjoyed the rural community experience, their communication and clinical skills improved. According to the staff, the placement programme was feasible and provided acceptable positive clinical and personal development for the students. This research will help educators planning to incorporate a rural clinical programme into a University curriculum. © 2012 John Wiley & Sons A/S.

  18. Porosity of spacer-filled channels in spiral-wound membrane systems: Quantification methods and impact on hydraulic characterization.

    Science.gov (United States)

    Siddiqui, A; Lehmann, S; Haaksman, V; Ogier, J; Schellenberg, C; van Loosdrecht, M C M; Kruithof, J C; Vrouwenvelder, J S

    2017-08-01

    The porosity of spacer-filled feed channels influences the hydrodynamics of spiral-wound membrane systems and impacts the overall performance of the system. Therefore, an exact measurement and a detailed understanding of the impact of the feed channel porosity is required to understand and improve the hydrodynamics of spiral-wound membrane systems applied for desalination and wastewater reuse. The objectives of this study were to assess the accuracy of porosity measurement techniques for feed spacers differing in geometry and thickness and the consequences of using an inaccurate method on hydrodynamic predictions, which may affect permeate production. Six techniques were applied to measure the porosity namely, three volumetric techniques based on spacer strand count together with a cuboidal (SC), cylindrical (VCC) and ellipsoidal volume calculation (VCE) and three independent techniques based on volume displacement (VD), weight and density (WD) and computed tomography (CT) scanning. The CT method was introduced as an alternative for the other five already existing and applied methods in practice. Six feed spacers used for the porosity measurement differed in filament thickness, angle between the filaments and mesh-size. The results of the studies showed differences between the porosities, measured by the six methods. The results of the microscopic techniques SC, VCC and VCE deviated significantly from measurements by VD, WD and CT, which showed similar porosity values for all spacer types. Depending on the maximum deviation of the porosity measurement techniques from -6% to +6%, (i) the linear velocity deviations were -5.6% and +6.4% respectively and (ii) the pressure drop deviations were -31% and +43% respectively, illustrating the importance of an accurate porosity measurement. Because of the accuracy and standard deviation, the VD and WD method should be applied for the porosity determination of spacer-filled channels, while the CT method is recommended

  19. Investigation of optical spacer layers from solution based precursors for polymer solar cells using X-ray reflectometry

    DEFF Research Database (Denmark)

    Andersen, Philip Hvidthøft Delff; Skårhøj, Jakob; Andreasen, Jens Wenzel

    2009-01-01

    Optical spacer layers based on titaniumalkoxide precursor solutions were prepared by spin-coating on top of bulk heterojunction layers based on poly-3-hexylthiophene (P3HT) and phenyl-C61-butyric acid methylester (PCBM). Models and experiment have shown that the performance of polymer solar cells...... can improve upon application of an optical spacer by shifting the maximum of the electrical field vector of the incident light into the active layer. This avoids the so called “dead zone” close to the reflective electrode. We demonstrate a simple linear model that can be used to predict the intensity...

  20. Porosity of spacer-filled channels in spiral-wound membrane systems: Quantification methods and impact on hydraulic characterization

    KAUST Repository

    Siddiqui, Amber

    2017-04-13

    The porosity of spacer-filled feed channels influences the hydrodynamics of spiral-wound membrane systems and impacts the overall performance of the system. Therefore, an exact measurement and a detailed understanding of the impact of the feed channel porosity is required to understand and improve the hydrodynamics of spiral-wound membrane systems applied for desalination and wastewater reuse. The objectives of this study were to assess the accuracy of porosity measurement techniques for feed spacers differing in geometry and thickness and the consequences of using an inaccurate method on hydrodynamic predictions, which may affect permeate production. Six techniques were applied to measure the porosity namely, three volumetric calculations based on spacer strand count together with cuboidal (SC), cylindrical (VCC) and ellipsoidal volume calculation (VCE) and three independent techniques based on volume displacement (VD), weight and density (WD) and computed tomography scanning (CT). The CT method was introduced as an alternative for the other five already existing and applied methods in practice.Six feed spacers used for the porosity measurement differed in filament thickness, angle between the filaments and mesh-size. The results of the studies showed differences between the porosities, measured by the six methods. The results of the microscopic techniques SC, VCC and VCE deviated significantly from measurements by VD, WD and CT, which showed similar porosity values for all spacer types.Depending on the maximum deviation of the porosity measurement techniques from –6% to +6%, (i) the linear velocity deviations were −5.6% and +6.4% respectively and (ii) the pressure drop deviations were –31% and +43% respectively, illustrating the importance of an accurate porosity measurement. Because of the accuracy and standard deviation, the VD and WD method should be applied for the porosity determination of spacer-filled channels, while the CT method is recommended for