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Sample records for calvarial defects filled

  1. Computed tomography of lambdoid calvarial defect in neurofibromatosis

    International Nuclear Information System (INIS)

    Mann, H.; Kozic, Z.; Medinilla, O.R.

    1983-01-01

    A patient with neurofibromatosis is reported in whom cranial computed tomography (CT) revealed a calvarial defect with an associated soft-tissue mass in the region of the left lambdoid suture. This defect has been the subject of several previous reports, having been demonstrated by means of conventional skull radiography. It should be included in the differential diagnosis when a lytic calvarial lesion is found on CT. (orig.)

  2. Reharvested cranial particulate bone graft ossifies inlay calvarial defects.

    Science.gov (United States)

    Hassanein, Aladdin H; Couto, Rafael A; Mulliken, John B; Rogers, Gary F; Greene, Arin K

    2012-09-01

    Particulate bone graft (PBG) heals calvarial critical-size defects and is procured from the cranium with a hand-driven bit and brace. The donor sites ossify, and thus PBG potentially could be reharvested from the original areas. The purpose of this study was to determine if PBG obtained from a healed donor site is effective for inlay cranioplasty. A 17 × 17-mm critical-size defect was created in the parietal bones of 8 rabbits and treated with either no implant (group 1) or PBG harvested from the frontal bone (group 2). In 4 animals (group 3), a parietal defect was not created initially; PBG was harvested from the frontal bone and then discarded. Sixteen weeks later after the PBG donor sites had healed, a 17 × 17-mm parietal defect was made and filled with PBG reharvested from the previous donor area. Animals underwent micro-computed tomography 16 weeks after inlay cranioplasty. Critical-size defects in controls (group 1) exhibited partial ossification (35.1% ± 10.5%) compared with those treated with PBG (group 2) (99.1% ± 1.5%) or reharvested PBG (group 3) (99.3% ± 1.5%) (P = 0.02). No difference was found between groups 2 and 3 (P = 0.69). Bony thickness was similar in defects implanted with PBG (1.8 mm ± 1.1 mm) or reharvested PBG (2.1 mm ± 0.5 mm) (P = 0.68). Particulate bone graft reharvested from healed donor sites ossifies inlay cranial defects. Because the donor area for PBG is of partial thickness and less than critical size, reparative osteogenesis theoretically allows an unlimited supply of autologous bone for inlay cranioplasty using PBG.

  3. Incomplete bone regeneration of rabbit calvarial defects using different membranes

    DEFF Research Database (Denmark)

    Aaboe, M; Pinholt, E M; Schou, S

    1998-01-01

    of the membrane. The calvarial defects of 2 groups were covered by an outer expanded polytetrafluoroethylene (ePTFE) membrane respectively by a Polyglactin 910 membrane. Bicortical ePTFE membranes or Polyglactin 910 membranes were used in 2 other groups. The defects were not covered by membranes in the control...... herniation into the defects. Subsequently, bone regeneration was impaired. The cellular reactions due to degradation of the material were minor and did not interfere with bone healing. Defects covered bicortically by ePTFE membranes revealed the largest amount of regenerated bone. The ePTFE membrane induced...

  4. Evaluation of Osteoconductive and Osteogenic Potential of a Dentin-Based Bone Substitute Using a Calvarial Defect Model

    Directory of Open Access Journals (Sweden)

    Ibrahim Hussain

    2012-01-01

    Full Text Available The aim of this study was to assess the osteoconductive and osteogenic properties of processed bovine dentin using a robust rabbit calvarial defect model. In total, 16 New Zealand White rabbits were operated to create three circular defects in the calvaria. One defect was left unfilled, one filled with collected autogenous bone, and the third defect was filled with the dentin-based bone substitute. Following surgery and after a healing period of either 1 or 6 weeks, a CT scan was obtained. Following sacrificing, the tissues were processed for histological examination. The CT data showed the density in the area grafted with the dentin-based material was higher than the surrounding bone and the areas grafted with autologous bone after 1 week and 6 weeks of healing. The area left unfilled remained an empty defect after 1 week and 6 weeks. Histological examination of the defects filled with the dentin product after 6 weeks showed soft tissue encapsulation around the dentin particles. It can be concluded that the rabbit calvarial model used in this study is a robust model for the assessment of bone materials. Bovine dentin is a biostable material; however, it may not be suitable for repairing large 4-wall defects.

  5. Benign gastric filling defect

    Energy Technology Data Exchange (ETDEWEB)

    Oh, K. K.; Lee, Y. H.; Cho, O. K.; Park, C. Y. [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    The gastric lesion is a common source of complaints to Orientals, however, evaluation of gastric symptoms and laboratory examination offer little specific aid in the diagnosis of gastric diseases. Thus roentgenography of gastrointestinal tract is one of the most reliable method for detail diagnosis. On double contract study of stomach, gastric filling defect is mostly caused by malignant gastric cancer, however, other benign lesions can cause similar pictures which can be successfully treated by surgery. 66 cases of benign causes of gastric filling defect were analyzed at this point of view, which was verified pathologically by endoscope or surgery during recent 7 years in Yensei University College of Medicine, Severance Hospital. The characteristic radiological picture of each disease was discussed for precise radiologic diagnosis. 1. Of total 66 cases, there were 52 cases of benign gastric tumor 10 cases of gastric varices, 5 cases of gastric bezoar, 5 cases of corrosive gastritis, 3 cases of granulomatous disease and one case of gastric hematoma. 2. The most frequent causes of benign tumors were adenomatous polyp (35/42) and the next was leiomyoma (4/42). Others were one of case of carcinoid, neurofibroma and cyst. 3. Characteristic of benign adenomatous polyp were relatively small in size, smooth surface and were observed that large size, benign polyp was frequently type IV lesion with a stalk. 4. Submucosal tumors such as leiomyoma needed differential diagnosis with polypoid malignant cancer. However, the characteristic points of differentiation was well circumscribed smooth margined filling defect without definite mucosal destruction on surface. 5. Gastric varices showed multiple lobulated filling defected especially on gastric fundus that changed its size and shape by respiration and posture of patients. Same varices lesions on esophagus and history of liver disease were helpful for easier diagnosis. 6. Gastric bezoar showed well defined movable mass

  6. Benign gastric filling defect

    International Nuclear Information System (INIS)

    Oh, K. K.; Lee, Y. H.; Cho, O. K.; Park, C. Y.

    1979-01-01

    The gastric lesion is a common source of complaints to Orientals, however, evaluation of gastric symptoms and laboratory examination offer little specific aid in the diagnosis of gastric diseases. Thus roentgenography of gastrointestinal tract is one of the most reliable method for detail diagnosis. On double contract study of stomach, gastric filling defect is mostly caused by malignant gastric cancer, however, other benign lesions can cause similar pictures which can be successfully treated by surgery. 66 cases of benign causes of gastric filling defect were analyzed at this point of view, which was verified pathologically by endoscope or surgery during recent 7 years in Yensei University College of Medicine, Severance Hospital. The characteristic radiological picture of each disease was discussed for precise radiologic diagnosis. 1. Of total 66 cases, there were 52 cases of benign gastric tumor 10 cases of gastric varices, 5 cases of gastric bezoar, 5 cases of corrosive gastritis, 3 cases of granulomatous disease and one case of gastric hematoma. 2. The most frequent causes of benign tumors were adenomatous polyp (35/42) and the next was leiomyoma (4/42). Others were one of case of carcinoid, neurofibroma and cyst. 3. Characteristic of benign adenomatous polyp were relatively small in size, smooth surface and were observed that large size, benign polyp was frequently type IV lesion with a stalk. 4. Submucosal tumors such as leiomyoma needed differential diagnosis with polypoid malignant cancer. However, the characteristic points of differentiation was well circumscribed smooth margined filling defect without definite mucosal destruction on surface. 5. Gastric varices showed multiple lobulated filling defected especially on gastric fundus that changed its size and shape by respiration and posture of patients. Same varices lesions on esophagus and history of liver disease were helpful for easier diagnosis. 6. Gastric bezoar showed well defined movable mass

  7. Effect of platelet-derived growth factor-BB on bone formation in calvarial defects: an experimental study in rabbits

    DEFF Research Database (Denmark)

    Vikjaer, D; Blom, S; Hjørting-Hansen, E

    1997-01-01

    The effect of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) on bone healing was examined in calvarial defects in rabbits. Bicortical circular (critical size) defects were prepared in the calvarial bone of 16 rabbits. The defects were closed on the dural side and covered externally...

  8. The effect of fresh bone marrow cells on reconstruction of mouse calvarial defect combined with calvarial osteoprogenitor cells and collagen-apatite scaffold.

    Science.gov (United States)

    Yu, Xiaohua; Wang, Liping; Peng, Fei; Jiang, Xi; Xia, Zengmin; Huang, Jianping; Rowe, David; Wei, Mei

    2013-12-01

    Fresh bone marrow cells have already exhibited its advantages as osteogenic donor cells, but the combination between fresh bone marrow cells and other donor cells utilized for bone healing has not been fully explored. To highlight the impact of fresh bone marrow cells on scaffold-based bone regeneration, single or a combination of calvarial osteoprogenitor cells (OPCs) and bone marrow cells (BMCs) were used as donor cells combined with collagen-apatite scaffold for calvarial defect healing. The host and donor contributions to bone formation were assessed using histological and GFP imaging analysis. Although the amount of new bone formed by different cell sources did not show significant differences, the origin of the bone formation in the defects mainly depended on the types of donor cells employed: when only calvarial OPCs were used as donor cells, a donor-derived bone healing instead of host-derived bone ingrowth was observed; when only fresh BMCs were loaded, the host bone could grow into the defect along the lamellar structure of the scaffolds, but the amount of new bone formed was significantly lower than the defect loaded with calvarial OPCs only. The combination of calvarial OPCs and fresh BMCs had similar amount of new bone formation as the group loaded with calvarial osteoprogenitors alone, but did not induce any host-derived bone formation. These results provide compelling evidence of the importance of fresh BMCs to induce host-implant integration in bone tissue engineering. Copyright © 2012 John Wiley & Sons, Ltd.

  9. A Versatile Protocol for Studying Calvarial Bone Defect Healing in a Mouse Model.

    Science.gov (United States)

    Samsonraj, Rebekah M; Dudakovic, Amel; Zan, Pengfei; Pichurin, Oksana; Cool, Simon M; van Wijnen, Andre J

    2017-11-01

    Animal models are vital tools for the preclinical development and testing of therapies aimed at providing solutions for several musculoskeletal disorders. For bone tissue engineering strategies addressing nonunion conditions, rodent models are particularly useful for studying bone healing in a controlled environment. The mouse calvarial defect model permits evaluation of drug, growth factor, or cell transplantation efficacy, together with offering the benefit of utilizing genetic models to study intramembranous bone formation within defect sites. In this study, we describe a detailed methodology for creating calvarial defects in mouse and present our results on bone morphogenetic protein-2-loaded fibrin scaffolds, thus advocating the utility of this functional orthotopic mouse model for the evaluation of therapeutic interventions (such as growth factors or cells) intended for successful bone regeneration therapies.

  10. Bone regeneration of calvarial defect using marine calcareous-derived beta-tricalcium phosphate macrospheres

    Directory of Open Access Journals (Sweden)

    Joshua Chou

    2014-02-01

    Full Text Available The aim of this study was to examine the bone regeneration properties of beta-tricalcium phosphate hydrothermally converted from foraminifera carbonate exoskeleton in the repair of rat calvarial defect. These natural materials possess unique interconnected porous network with uniform pore size distribution, which can be potentially advantageous. In total, 20 adult male Wistar rats received full-thickness calvarial defect with a diameter of 5 mm. The rate of newly formed bone was measured radiologically by X-ray and micro-computed tomography and by histologic examination. After 2 weeks, the beta-tricalcium phosphate group exhibited full closure of the defect site, while control group remained unrestored at the end of the 6-week experimentation. It was observed that the newly regenerated bone thickened over the course of the experiment in the beta-tricalcium phosphate group. No soft tissue reaction was observed around the beta-tricalcium phosphate implant and the rats remained healthy. These results showed that repair of the calvarial defect can be achieved by biomimetic beta-tricalcium phosphate macrospheres, which hold potential for application as bone grafts for bone augmentation surgeries.

  11. Incomplete bone regeneration of rabbit calvarial defects using different membranes

    DEFF Research Database (Denmark)

    Aaboe, M; Pinholt, E M; Schou, S

    1998-01-01

    group. Undecalcified sections were prepared for histologic evaluation after an observation period of 8 weeks. Complete bone healing of the defects was not observed in any of the specimens. The Polyglactin 910 material lacks physical strength, resulting in collapse of the membrane and brain tissue...

  12. In vivo micro-CT analysis of bone remodeling in a rat calvarial defect model

    Energy Technology Data Exchange (ETDEWEB)

    Umoh, Joseph U; Holdsworth, David W [Pre-Clinical Imaging Research Centre, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, PO Box 5015, 100 Perth Drive, London, ON N6A 5K8 (Canada); Sampaio, Arthur V; Underhill, T Michael [Laboratory of Molecular Skeletogenesis, Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC (Canada); Welch, Ian [Animal Care and Veterinary Services, University of Western Ontario, London, ON (Canada); Pitelka, Vasek; Goldberg, Harvey A [CIHR Group in Skeletal Development and Remodelling, University of Western Ontario, London, ON (Canada)], E-mail: jumoh@imaging.robarts.ca, E-mail: asampaio@interchange.ubc.ca, E-mail: tunderhi@interchange.ubc.ca, E-mail: iwelch@uwo.ca, E-mail: vasek.pitelka@schulich.uwo.ca, E-mail: hagoldbe@uwo.ca, E-mail: david.holdsworth@imaging.robarts.ca

    2009-04-07

    The rodent calvarial defect model is commonly used to investigate bone regeneration and wound healing. This study presents a micro-computed tomography (micro-CT) methodology for measuring the bone mineral content (BMC) in a rat calvarial defect and validates it by estimating its precision error. Two defect models were implemented. A single 6 mm diameter defect was created in 20 rats, which were imaged in vivo for longitudinal experiments. Three 5 mm diameter defects were created in three additional rats, which were repeatedly imaged ex vivo to determine precision. Four control rats and four rats treated with bone morphogenetic protein were imaged at 3, 6, 9 and 12 weeks post-surgery. Scan parameters were 80 kVp, 0.45 mA and 180 mAs. Images were reconstructed with an isotropic resolution of 45 {mu}m. At 6 weeks, the BMC in control animals (4.37 {+-} 0.66 mg) was significantly lower (p < 0.05) than that in treated rats (11.29 {+-} 1.01 mg). Linear regression between the BMC and bone fractional area, from 20 rats, showed a strong correlation (r{sup 2} = 0.70, p < 0.0001), indicating that the BMC can be used, in place of previous destructive analysis techniques, to characterize bone growth. The high precision (2.5%) of the micro-CT methodology indicates its utility in detecting small BMC changes in animals.

  13. Enhancing dermal and bone regeneration in calvarial defect surgery

    Directory of Open Access Journals (Sweden)

    Bruno Zanotti

    2014-01-01

    Full Text Available Introduction: To optimize the functional and esthetic result of cranioplasty, it is necessary to choose appropriate materials and take steps to preserve and support tissue vitality. As far as materials are concerned, custom-made porous hydroxyapatite implants are biomimetic, and therefore, provide good biological interaction and biointegration. However, before it is fully integrated, this material has relatively low mechanical resistance. Therefore, to reduce the risk of postoperative implant fracture, it would be desirable to accelerate regeneration of the tissues around and within the graft. Objectives: The objective was to determine whether integrating growth-factor-rich platelet gel or supportive dermal matrix into hydroxyapatite implant cranioplasty can accelerate bone remodeling and promote soft tissue regeneration, respectively. Materials and Methods: The investigation was performed on cranioplasty patients fitted with hydroxyapatite cranial implants between 2004 and 2010. In 7 patients, platelet gel was applied to the bone/prosthesis interface during surgery, and in a further 5 patients, characterized by thin, hypotrophic skin coverage of the cranial lacuna, a sheet of dermal matrix was applied between the prosthesis and the overlying soft tissue. In several of the former groups, platelet gel mixed with hydroxyapatite granules was used to fill small gaps between the skull and the implant. To confirm osteointegration, cranial computed tomography (CT scans were taken at 3-6 month intervals for 1-year, and magnetic resonance imaging (MRI was used to confirm dermal integrity. Results: Clinical examination performed a few weeks after surgery revealed good dermal regeneration, with thicker, healthier skin, apparently with a better blood supply, which was confirmed by MRI at 3-6 months. Furthermore, at 3-6 months, CT showed good biomimetism of the porous hydroxyapatite scaffold. Locations at which platelet gel and hydroxyapatite granules were

  14. Enhancing dermal and bone regeneration in calvarial defect surgery.

    Science.gov (United States)

    Zanotti, Bruno; Zingaretti, Nicola; Almesberger, Daria; Verlicchi, Angela; Stefini, Roberto; Ragonese, Mauro; Guarneri, Gianni Franco; Parodi, Pier Camillo

    2014-01-01

    To optimize the functional and esthetic result of cranioplasty, it is necessary to choose appropriate materials and take steps to preserve and support tissue vitality. As far as materials are concerned, custom-made porous hydroxyapatite implants are biomimetic, and therefore, provide good biological interaction and biointegration. However, before it is fully integrated, this material has relatively low mechanical resistance. Therefore, to reduce the risk of postoperative implant fracture, it would be desirable to accelerate regeneration of the tissues around and within the graft. The objective was to determine whether integrating growth-factor-rich platelet gel or supportive dermal matrix into hydroxyapatite implant cranioplasty can accelerate bone remodeling and promote soft tissue regeneration, respectively. The investigation was performed on cranioplasty patients fitted with hydroxyapatite cranial implants between 2004 and 2010. In 7 patients, platelet gel was applied to the bone/prosthesis interface during surgery, and in a further 5 patients, characterized by thin, hypotrophic skin coverage of the cranial lacuna, a sheet of dermal matrix was applied between the prosthesis and the overlying soft tissue. In several of the former groups, platelet gel mixed with hydroxyapatite granules was used to fill small gaps between the skull and the implant. To confirm osteointegration, cranial computed tomography (CT) scans were taken at 3-6 month intervals for 1-year, and magnetic resonance imaging (MRI) was used to confirm dermal integrity. Clinical examination performed a few weeks after surgery revealed good dermal regeneration, with thicker, healthier skin, apparently with a better blood supply, which was confirmed by MRI at 3-6 months. Furthermore, at 3-6 months, CT showed good biomimetism of the porous hydroxyapatite scaffold. Locations at which platelet gel and hydroxyapatite granules were used to fill gaps between the implant and skull appeared to show more rapid

  15. Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takao; Iizuka, Tadashi; Kanamori, Takeshi; Yokoyama, Atsuro [Department of Oral Functional Prosthodontics, Division of Oral Functional Science, Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo, Hokkaido 060-8586 (Japan); Matsumura, Sachiko; Shiba, Kiyotaka [Division of Protein Engineering, Cancer Institute, Japanese Foundation for Cancer Research, 3-8-31, Ariake, koutou-ku, Tokyo 135-8550 (Japan); Yudasaka, Masako; Iijima, Sumio, E-mail: tkasai@den.hokudai.ac.jp [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology, Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan)

    2011-02-11

    A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified. The purpose of this study was to evaluate the effect of CNHs on bone regeneration and their possible application for guided bone regeneration (GBR). CNHs dispersed in ethanol were fixed on a porous polytetrafluoroethylene membrane by vacuum filtration. Cranial defects were created in rats and covered by a membrane with/without CNHs. At two weeks, bone formation under the membrane with CNHs had progressed more than under that without CNHs and numerous macrophages were observed attached to CNHs. At eight weeks, there was no significant difference in the amount of newly formed bone between the groups and the appearance of macrophages was decreased compared with that at two weeks. Newly formed bone attached to some CNHs directly. These results suggest that macrophages induced by CNHs are related to bone regeneration. In conclusion, the present study indicates that CNHs are compatible with bone tissue and effective as a material for GBR.

  16. Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect

    Science.gov (United States)

    Kasai, Takao; Matsumura, Sachiko; Iizuka, Tadashi; Shiba, Kiyotaka; Kanamori, Takeshi; Yudasaka, Masako; Iijima, Sumio; Yokoyama, Atsuro

    2011-02-01

    A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified. The purpose of this study was to evaluate the effect of CNHs on bone regeneration and their possible application for guided bone regeneration (GBR). CNHs dispersed in ethanol were fixed on a porous polytetrafluoroethylene membrane by vacuum filtration. Cranial defects were created in rats and covered by a membrane with/without CNHs. At two weeks, bone formation under the membrane with CNHs had progressed more than under that without CNHs and numerous macrophages were observed attached to CNHs. At eight weeks, there was no significant difference in the amount of newly formed bone between the groups and the appearance of macrophages was decreased compared with that at two weeks. Newly formed bone attached to some CNHs directly. These results suggest that macrophages induced by CNHs are related to bone regeneration. In conclusion, the present study indicates that CNHs are compatible with bone tissue and effective as a material for GBR.

  17. Effect of GBR in Combination with Deproteinized Bovine Bone Mineral on the Healing of Calvarial Defects in Rabbits

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    AA. Khoshkhoonejad

    2006-06-01

    Full Text Available Statement of problem: The guided bone regeneration (GBR technique does not always produce consistent results. Bone filling within the space provided by the membrane can be incomplete.Purpose: The aim of this study was to evaluate the effect of a collagen membrane (Bio-Gide in combination with or without deproteinezed bovine bone mineral (Bio-Oss on the healing of calvarial defects in rabbits.Materials and Methods: Twelve New Zealand white rabbits were used in this randomized single-blind experimental study. Four equal defects were created on the calvarium of all animals. Each defect in each rabbit was randomly assigned to one of the following treatment groups: Group 1(control, no treatment; Group 2, covered withBio-Gide; Group 3, filled with Bio-Oss; Group 4, filled with Bio-Oss and Bio-Gide.The animals were sacrificed for histologic and histomorphometric analysis, 30 and 60 days after treatment.Results: A significant difference was not observed in regenerated bone between the control and Bio-Gide groups (P>0.05, at 1 and 2 months. The amount of regenerated bone was significantly higher (P0.05 between the Bio-Oss and Bio-Oss+Bio-Gide groups. Bone regeneration increased significantly in all treatment groups, between the two study periods (P<0.05.Conclusion: In groups 3 and 4, the presence of a collagen membrane did not affect the amount of new bone regeneration. According to these results, use of a collagen membrane has no additional benefit in the regeneration of intrabony defects.

  18. Effects of a chitosan membrane coated with polylactic and polyglycolic acid on bone regeneration in a rat calvarial defect

    International Nuclear Information System (INIS)

    Jung, Ui-Won; Song, Kun-Young; Kim, Chang-Sung; Lee, Yong-Keun; Cho, Kyoo-Sung; Kim, Chong-Kwan; Choi, Seong-Ho

    2007-01-01

    The purpose of this study was to evaluate the effects of a chitosan membrane coated with polylactic and polyglycolic acid (PLGA) on bone regeneration in a rat calvarial defect. Surgical implantation of chitosan membranes resulted in enhanced local bone formation at both 2 and 8 weeks. In conclusion, the chitosan membrane coated with PLGA had a significant potential to induce bone formation in the rat calvarial defect model. Within the selected PLGA dose range and observation intervals, there appeared to be no meaningful differences in bone formation

  19. Optimized Bone Regeneration in Calvarial Bone Defect Based on Biodegradation-Tailoring Dual-shell Biphasic Bioactive Ceramic Microspheres.

    Science.gov (United States)

    Xu, Antian; Zhuang, Chen; Xu, Shuxin; He, Fuming; Xie, Lijun; Yang, Xianyan; Gou, Zhongru

    2018-02-21

    Bioceramic particulates capable of filling bone defects have gained considerable interest over the last decade. Herein, dual-shell bioceramic microspheres (CaP@CaSi@CaP, CaSi@CaP@CaSi) with adjustable beta-tricalcium phosphate (CaP) and beta-calcium silicate (CaSi) distribution were fabricated using a co-concentric capillary system enabling bone repair via a tailorable biodegradation process. The in vitro results showed the optimal concentration (1/16 of 200 mg/ml) of extracts of dual-shell microspheres could promote bone marrow mesenchymal cell (BMSC) proliferation and enhance the level of ALP activity and Alizarin Red staining. The in vivo bone repair and microsphere biodegradation in calvarial bone defects were compared using micro-computed tomography and histological evaluations. The results indicated the pure CaP microspheres were minimally resorbed at 18 weeks post-operatively and new bone tissue was limited; however, the dual-shell microspheres were appreciably biodegraded with time in accordance with the priority from CaSi to CaP in specific layers. The CaSi@CaP@CaSi group showed a significantly higher ability to promote bone regeneration than the CaP@CaSi@CaP group. This study indicates that the biphasic microspheres with adjustable composition distribution are promising for tailoring material degradation and bone regeneration rate, and such versatile design strategy is thought to fabricate various advanced biomaterials with tailorable biological performances for bone reconstruction.

  20. The effects of newly formed synthetic peptide on bone regeneration in rat calvarial defects.

    Science.gov (United States)

    Choi, Jung-Yoo; Jung, Ui-Won; Kim, Chang-Sung; Eom, Tae-Kwan; Kang, Eun-Jung; Cho, Kyoo-Sung; Kim, Chong-Kwan; Choi, Seong-Ho

    2010-02-01

    Significant interest has emerged in the design of cell scaffolds that incorporate peptide sequences that correspond to known signaling domains in extracellular matrix and bone morphogenetic protein. The purpose of this study was to evaluate the bone regenerative effects of the synthetic peptide in a critical-size rat calvarial defect model. Eight millimeter diameter standardized, circular, transosseus defects created on the cranium of forty rats were implanted with synthetic peptide, collagen, or both synthetic peptide and collagen. No material was was implanted the control group. The healing of each group was evaluated histologically and histomorphometrically after 2- and 8-week healing intervals. Surgical implantation of the synthetic peptide and collagen resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. When the experimental groups were compared to each other, they showed a similar pattern of bone formation. The defect closure and new bone area were significantly different in synthetic peptide and collagen group at 8 weeks. Concerning the advantages of biomaterials, synthetic peptide can be an effective biomaterial for damaged periodontal regeneration.

  1. Regeneration of calvarial defects by a composite of bioerodible polyorthoester and demineralized bone in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1992-01-01

    polyorthoester and demineralized bone or demineralized bone alone were bridged by bone. Unfilled defects or defects filled with polyorthoester only did not heal. The polyorthoester caused slight inflammation that subsided by 3 weeks, and only traces of the filler could be detected at 4 weeks. The polyorthoester...

  2. Effect of platelet-derived growth factor-BB on bone formation in calvarial defects: an experimental study in rabbits

    DEFF Research Database (Denmark)

    Vikjaer, D; Blom, S; Hjørting-Hansen, E

    1997-01-01

    The effect of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) on bone healing was examined in calvarial defects in rabbits. Bicortical circular (critical size) defects were prepared in the calvarial bone of 16 rabbits. The defects were closed on the dural side and covered externally......, and the bone formation was evaluated after 8 weeks. Healing of defects in both groups was characterized by the presence of newly formed bone along the edges of the original defect and by a central area of fibrous connective tissue. The newly formed bone in the rhPDGF-BB treated defects had a trabecular...... structure; in contrast, a more compact structure was found in the control defects. In the rhPDGF-BB-treated defects, the bone ingrowth was 51.8 +/- 7.1% compared to 30.5 +/- 3.3% in the control defects. Furthermore, the amount of mineralized tissue was increased 112% in the rhPDGF-BB group. The amount...

  3. Comparative study of porous hydroxyapatite/chitosan and whitlockite/chitosan scaffolds for bone regeneration in calvarial defects

    Science.gov (United States)

    Zhou, Ding; Qi, Chao; Chen, Yi-Xuan; Zhu, Ying-Jie; Sun, Tuan-Wei; Chen, Feng; Zhang, Chang-Qing

    2017-01-01

    Hydroxyapatite (HAP; Ca10(PO4)6(OH)2) and whitlockite (WH; Ca18Mg2(HPO4)2(PO4)12) are widely utilized in bone repair because they are the main components of hard tissues such as bones and teeth. In this paper, we synthesized HAP and WH hollow microspheres by using creatine phosphate disodium salt as an organic phosphorus source in aqueous solution through microwave-assisted hydrothermal method. Then, we prepared HAP/chitosan and WH/chitosan composite membranes to evaluate their biocompatibility in vitro and prepared porous HAP/chitosan and WH/chitosan scaffolds by freeze drying to compare their effects on bone regeneration in calvarial defects in a rat model. The experimental results indicated that the WH/chitosan composite membrane had a better biocompatibility, enhancing proliferation and osteogenic differentiation ability of human mesenchymal stem cells than HAP/chitosan. Moreover, the porous WH/chitosan scaffold can significantly promote bone regeneration in calvarial defects, and thus it is more promising for applications in tissue engineering such as calvarial repair compared to porous HAP/chitosan scaffold. PMID:28435251

  4. Dural sinus filling defect: intrasigmoid encephalocele

    Science.gov (United States)

    Karatag, Ozan; Cosar, Murat; Kizildag, Betul; Sen, Halil Murat

    2013-01-01

    Filling defects of dural venous sinuses are considered to be a challenging problem especially in case of symptomatic patients. Many lesions have to be ruled out such as sinus thrombosis, arachnoid granulations and tumours. Encephalocele into dural sinus is also a rare cause of these filling defects of dural sinuses. Here, we report an extremely rare case with spontaneous occult invagination of temporal brain tissue into the left sigmoid sinus and accompanying cerebellar ectopia. PMID:24311424

  5. Guided bone regeneration in standardized calvarial defects using beta-tricalcium phosphate and collagen membrane: a real-time in vivo micro-computed tomographic experiment in rats.

    Science.gov (United States)

    Ramalingam, Sundar; Al-Rasheed, Abdulaziz; ArRejaie, Aws; Nooh, Nasser; Al-Kindi, Mohammed; Al-Hezaimi, Khalid

    2016-05-01

    Guided bone regeneration (GBR) procedures using graft materials have been used for reconstruction of osseous defects. The aim of the present in vivo micro-computed tomographic (µCT) and histologic study was to assess in real time the bone regeneration at GBR sites in standardized experimental calvarial defects (diameter 3.3 mm) using β-tricalcium phosphate (β-TCP) with and without collagen membrane (CM). A single full-thickness calvarial defect was created on the left parietal bone in young female Wistar albino rats (n = 30) weighing approximately 300 g and aged about 6 weeks. The animals were randomly divided into three groups for treatment, based on calvarial defect filling material: (1) control group (n = 10); (2) β-TCP + CM group (n = 10); (3) β-TCP group (n = 10). Real-time in vivo µCT analyses were performed immediately after surgery and at 2, 4, 6 and 10 weeks to determine the volume and mineral density of the newly formed bone (BVNFB, MDNFB) and remaining β-TCP particles (VRBP, MDRBP). The animals were killed at 10 weeks and calvarial specimens were evaluated histologically. In the control group, MDNFB increased significantly at 6 weeks (0.32 ± 0.002 g/mm(3), P < 0.01) compared to that at baseline. In β-TCP + CM group, BVNFB (1.10 ± 0.12 mm(3), P < 0.01) and MDNFB (0.13 ± 0.02 g/mm(3), P < 0.01) significantly increased at the 4th week than baseline. In the β-TCP group, BVNFB (1.13 ± 0.12 mm(3), P < 0.01) and MDNFB (0.14 ± 0.01 g/mm(3), P < 0.01) significantly increased at 6 weeks compared to that at baseline. Significant reduction in VRBP was neither seen in the β-TCP + CM group nor in the β-TCP group. While in the β-TCP + CM group MDRBP was reduced significantly at 6 weeks (0.44 ± 0.9 g/mm(3), P < 0.01) from baseline (0.98 ± 0.03 g/mm(3)), similar significant reduction in MDRBP from baseline (0.92 ± 0.07 g/mm(3)) was seen only at 10 weeks (0.45 ± 0.06 g/mm(3), P < 0.05) in the β-TCP group. Histologic findings at 10 weeks revealed

  6. Sequential Treatment with SDF-1 and BMP-2 Potentiates Bone Formation in Calvarial Defects.

    Science.gov (United States)

    Hwang, Hee-Don; Lee, Jung-Tae; Koh, Jeong-Tae; Jung, Hong-Moon; Lee, Heon-Jin; Kwon, Tae-Geon

    2015-07-01

    Stromal cell-derived factor-1 (SDF-1) protein and its receptor, CXCR-4, play an important role in tissue repair and regeneration in various organs, including the bone. SDF-1 is indispensable for bone morphogenetic protein-2 (BMP-2)-induced osteogenic differentiation. However, SDF-1 is not needed after the osteogenic induction has been activated. Since the precise condition for the additive effects of combined DF-1 and BMP-2 in bone healing had not been fully investigated, we aimed to determine the optimal conditions for SDF-1- and BMP-2-mediated bone regeneration. We examined the in vitro osteoblastic differentiation and cell migration after sequential treatments with SDF-1 and BMP-2. Based on the in vitro additive effects of SDF-1 and BMP-2, the critical size defects of mice calvaria were treated with these cytokines in various sequences. Phosphate buffered saline (PBS)-, SDF-1-, or BMP-2-soaked collagen scaffolds were implanted into the calvarial defects (n=36). Periodic percutaneous injections of PBS or the cytokine SDF-1 and BMP-2 into the implanted scaffolds were performed on days 3 and 6, postoperatively. Six experimental groups were used according to the types and sequences of the cytokine treatments. After 28 days, the mice were euthanized and bone formation was evaluated with microcomputed tomography and histology. The molecular mechanism of the additive effect of SDF-1 and BMP-2 was evaluated by analyzing intracellular signal transduction through Smad and Erk phosphorylation. The in vitro experiments revealed that, among all the treatments, the treatment with BMP-2 after SDF-1 showed the strongest osteoblastic differentiation and enhanced cell migration. Similarly, in the animal model, the treatment with SDF-1 followed by BMP-2 treatment showed the highest degree of new bone regeneration than any other groups, including the one with continuous BMP-2 treatment. This new bone formation can be partially explained by the activation of Smad and Erk pathways

  7. Injectable Reactive Biocomposites For Bone Healing In Critical-Size Rabbit Calvarial Defects

    Science.gov (United States)

    2012-03-29

    anterior lumbar interbody fusion and periodontal ridge augmentation (INFUSE R© bone graft) [21, 22]. When implanted in a rabbit calvarial CSD, rhBMP-2...Lewis G 2007 Percutaneous vertebroplasty and kyphoplasty for the stand-alone augmentation of osteoporosis -induced vertebral compression fractures

  8. Deletion of SHP-2 in mesenchymal stem cells causes growth retardation, limb and chest deformity, and calvarial defects in mice

    Directory of Open Access Journals (Sweden)

    Philip E. Lapinski

    2013-11-01

    In mice, induced global disruption of the Ptpn11 gene, which encodes the SHP-2 tyrosine phosphatase, results in severe skeletal abnormalities. To understand the extent to which skeletal abnormalities can be attributed to perturbation of SHP-2 function in bone-forming osteoblasts and chondrocytes, we generated mice in which disruption of Ptpn11 is restricted to mesenchymal stem cells (MSCs and their progeny, which include both cell types. MSC-lineage-specific SHP-2 knockout (MSC SHP-2 KO mice exhibited postnatal growth retardation, limb and chest deformity, and calvarial defects. These skeletal abnormalities were associated with an absence of mature osteoblasts and massive chondrodysplasia with a vast increase in the number of terminally differentiated hypertrophic chondrocytes in affected bones. Activation of mitogen activated protein kinases (MAPKs and protein kinase B (PKB; also known as AKT was impaired in bone-forming cells of MSC SHP-2 KO mice, which provides an explanation for the skeletal defects that developed. These findings reveal a cell-autonomous role for SHP-2 in bone-forming cells in mice in the regulation of skeletal development. The results add to our understanding of the pathophysiology of skeletal abnormalities observed in humans with germline mutations in the PTPN11 gene (e.g. Noonan syndrome and LEOPARD syndrome.

  9. Repair of calvarial bone defects in mice using electrospun polystyrene scaffolds combined with β-TCP or gold nanoparticles.

    Science.gov (United States)

    Terranova, Lisa; Dragusin, Diana Maria; Mallet, Romain; Vasile, Eugeniu; Stancu, Izabela-Cristina; Behets, Catherine; Chappard, Daniel

    2017-02-01

    Non-biodegradable porous polystyrene (PS) scaffolds, composed of microfibers, have been prepared by electrospinning for the reconstruction of large bone defects. PS microfibers were prepared by incorporating β-TCP grains inside the polymer or grafting gold nanoparticles surface functionalized with mercaptosuccinic acid. Cytocompatibility of the three types of scaffolds (PS, β-TCP-PS and Au-PS) was studied by seeding human mesenchymal stem cells. Biocompatibility was evaluated by implanting β-TCP-PS and Au-PS scaffolds into a critical size (4mm) calvarial defect in mice. Calvaria were taken 6, 9, and 12 weeks after implantation; newly formed bone and cellular response was analyzed by microcomputed tomography (microCT) and histology. β-TCP-PS scaffolds showed a significantly higher cell proliferation in vitro than on PS or Au-PS alone; clearly, the presence of β-TCP grains improved cytocompatibility. Biocompatibility study in the mouse calvaria model showed that β-TCP-PS scaffolds were significantly associated with more newly-formed bone than Au-PS. Bone developed by osteoconduction from the defect margins to the center. A dense fibrous connective tissue containing blood vessels was identified histologically in both types of scaffolds. There was no inflammatory foci nor giant cell in these areas. AuNPs aggregates were identified histologically in the fibrosis and also incorporated in the newly-formed bone matrix. Although the different types of PS microfibers appeared cytocompatible during the in vitro experiment, they appeared biotolerated in vivo since they induced a fibrotic reaction associated with newly formed bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Evaluation of Bone Regeneration on Polyhydroxyethyl-polymethyl Methacrylate Membrane in a Rabbit Calvarial Defect Model.

    Science.gov (United States)

    Kim, Somin; Hwang, Yawon; Kashif, Muhammad; Jeong, Dosun; Kim, Gonhyung

    This study was conducted to evaluate the capacity of guiding bone regeneration of polyhydroxyethyl-polymethyl methacrylate (PHEMA-PMMA) membrane as a guided tissue regeneration membrane for bone defects. Two 8-mm diameter transosseous round defects were made at the parietal bone of 18 New Zealand White rabbits. Defects were covered with or without PHEMA-PMMA membrane. Radiological and histological evaluation revealed that the bone tissue over the defect was more regenerated with time in both groups. However, there was significantly more bone regeneration at 8 weeks in the experimental group than the control group (p<0.05). There was no sign of membrane degradation or tissue inflammation and no invasion of muscle and fibrous tissue into defects. PHEMA-PMMA is a potential material for guided tissue regeneration membrane as it induces no adverse tissue reaction and effectively supports selective bone regeneration. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  11. Engineering biomimetic periosteum with β-TCP scaffolds to promote bone formation in calvarial defects of rats.

    Science.gov (United States)

    Zhang, Dan; Gao, Peng; Li, Qin; Li, Jinda; Li, Xiaojuan; Liu, Xiaoning; Kang, Yunqing; Ren, Liling

    2017-06-05

    There is a critical need for the management of large bone defects. The purpose of this study was to engineer a biomimetic periosteum and to combine this with a macroporous β-tricalcium phosphate (β-TCP) scaffold for bone tissue regeneration. Rat bone marrow-derived mesenchymal stem cells (rBMSCs) were harvested and cultured in different culture media to form undifferentiated rBMSC sheets (undifferentiated medium (UM)) and osteogenic cell sheets (osteogenic medium (OM)). Simultaneously, rBMSCs were differentiated to induced endothelial-like cells (iECs), and the iECs were further cultured on a UM to form a vascularized cell sheet. At the same time, flow cytometry was used to detect the conversion rates of rBMSCs to iECs. The pre-vascularized cell sheet (iECs/UM) and the osteogenic cell sheet (OM) were stacked together to form a biomimetic periosteum with two distinct layers, which mimicked the fibrous layer and cambium layer of native periosteum. The biomimetic periostea were wrapped onto porous β-TCP scaffolds (BP/β-TCP) and implanted in the calvarial bone defects of rats. As controls, autologous periostea with β-TCP (AP/β-TCP) and β-TCP alone were implanted in the calvarial defects of rats, with a no implantation group as another control. At 2, 4, and 8 weeks post-surgery, implants were retrieved and X-ray, microcomputed tomography (micro-CT), histology, and immunohistochemistry staining analyses were performed. Flow cytometry results showed that rBMSCs were partially differentiated into iECs with a 35.1% conversion rate in terms of CD31. There were still 20.97% rBMSCs expressing CD90. Scanning electron microscopy (SEM) results indicated that cells from the wrapped cell sheet on the β-TCP scaffold apparently migrated into the pores of the β-TCP scaffold. The histology and immunohistochemistry staining results from in vivo implantation indicated that the BP/β-TCP and AP/β-TCP groups promoted the formation of blood vessels and new bone tissues in the bone

  12. Bone regeneration in rat calvarial defects implanted with fibrous scaffolds composed of a mixture of silicate and borate bioactive glasses.

    Science.gov (United States)

    Gu, Yifei; Huang, Wenhai; Rahaman, Mohamed N; Day, Delbert E

    2013-11-01

    Previous studies have evaluated the capacity of porous scaffolds composed of a single bioactive glass to regenerate bone. In the present study, scaffolds composed of a mixture of two different bioactive glasses (silicate 13-93 and borate 13-93B3) were created and evaluated for their response to osteogenic MLO-A5 cells in vitro and their capacity to regenerate bone in rat calvarial defects in vivo. The scaffolds, which have similar microstructures (porosity=58-67%) and contain 0, 25, 50 and 100 wt.% 13-93B3 glass, were fabricated by thermally bonding randomly oriented short fibers. The silicate 13-93 scaffolds showed a better capacity to support cell proliferation and alkaline phosphatase activity than the scaffolds containing borate 13-93B3 fibers. The amount of new bone formed in the defects implanted with the 13-93 scaffolds at 12 weeks was 31%, compared to values of 25, 17 and 20%, respectively, for the scaffolds containing 25, 50 and 100% 13-93B3 glass. The amount of new bone formed in the 13-93 scaffolds was significantly higher than in the scaffolds containing 50 and 100% 13-93B3 glass. While the 13-93 fibers were only partially converted to hydroxyapatite at 12 weeks, the 13-93B3 fibers were fully converted and formed a tubular morphology. Scaffolds composed of an optimized mixture of silicate and borate bioactive glasses could provide the requisite architecture to guide bone regeneration combined with a controllable degradation rate that could be beneficial for bone and tissue healing. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Effect of bioactive borate glass microstructure on bone regeneration, angiogenesis, and hydroxyapatite conversion in a rat calvarial defect model.

    Science.gov (United States)

    Bi, Lianxiang; Rahaman, Mohamed N; Day, Delbert E; Brown, Zackary; Samujh, Christopher; Liu, Xin; Mohammadkhah, Ali; Dusevich, Vladimir; Eick, J David; Bonewald, Lynda F

    2013-08-01

    Borate bioactive glasses are biocompatible and enhance new bone formation, but the effect of their microstructure on bone regeneration has received little attention. In this study scaffolds of borate bioactive glass (1393B3) with three different microstructures (trabecular, fibrous, and oriented) were compared for their capacity to regenerate bone in a rat calvarial defect model. 12weeks post-implantation the amount of new bone, mineralization, and blood vessel area in the scaffolds were evaluated using histomorphometric analysis and scanning electron microscopy. The amount of new bone formed was 33%, 23%, and 15%, respectively, of the total defect area for the trabecular, oriented, and fibrous microstructures. In comparison, the percent new bone formed in implants composed of silicate 45S5 bioactive glass particles (250-300μm) was 19%. Doping the borate glass with copper (0.4 wt.% CuO) had little effect on bone regeneration in the trabecular and oriented scaffolds, but significantly enhanced bone regeneration in the fibrous scaffolds (from 15 to 33%). The scaffolds were completely converted to hydroxyapatite within the 12week implantation. The amount of hydroxyapatite formed, 22%, 35%, and 48%, respectively, for the trabecular, oriented, and fibrous scaffolds, increased with increasing volume fraction of glass in the as-fabricated scaffold. Blood vessels infiltrated into all the scaffolds, but the trabecular scaffolds had a higher average blood vessel area compared with the oriented and fibrous scaffolds. While all three scaffold microstructures were effective in supporting bone regeneration, the trabecular scaffolds supported more bone formation and may be more promising in bone repair. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  14. Microarray gene expression during early healing of GBR-treated calvarial critical size defects.

    Science.gov (United States)

    Al-Kattan, R; Retzepi, M; Calciolari, E; Donos, N

    2017-10-01

    To investigate the gene expression and molecular pathways implicated in the regulation of the osseous healing process following guided bone regeneration (GBR). Six 6-month-old Wistar male rats were used. Standardized 5-mm critical size defects were created in the parietal bones of each animal and treated with an extracranial and intracranial ePTFE membrane, according to the GBR principle. Three animals were randomly sacrificed after 7 and 15 days of healing. Total RNA was extracted from each sample and prepared for gene expression analysis. RNA quality and quantity were assessed, followed by hybridization of the cRNA to Affymetrix GeneChip Rat Genome 230 2.0 Arrays. The Affymetrix data were processed, and first-order analysis, quality control and statistical analysis were performed. Biological interpretation was performed via pathway and Gene Ontology (GO) analysis. Between the 7- and 15-day samples, 538 genes were differently regulated. At day 7, inflammatory and immune responses were clearly upregulated. In addition, GO terms related to angiogenesis and cell cycle regulation were overexpressed. At day 15, a more complex cellular activity and cell metabolism were evident. The bone formation processes were significantly overexpressed, with several genes encoding growth factors, enzyme activity, and extracellular matrix formation found as upregulated. Remarkably, a negative regulation of Wnt signalling pathway was observed at 15 days. The gene expression profile of the cells participating in osseous formation varied depending on the healing stage. A number of candidate genes that seem differentially expressed during early stages of intramembranous bone regeneration was suggested. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Effect of recombinant PDGF-BB on bone formation in the presence of β-tricalcium phosphate and bovine bone mineral matrix: a pilot study in rat calvarial defects.

    Science.gov (United States)

    Luvizuto, Eloá R; Tangl, Stefan; Dobsak, Toni; Reich, Karoline; Gruber, Reinhard; Sonoda, Celso K; Okamoto, Roberta

    2016-05-04

    Supplementation of bone substitutes with recombinant platelet-derived growth factor-BB (PDGF-BB) can enhance bone regeneration. The aim of the study was to evaluate the effect of PDGF-BB on bone formation in the presence of β-tricalcium phosphate and bovine bone mineral matrix in a rat calvaria defect model. The authors examined 5 mm rat calvarial defects treated with β-tricalcium phosphate (TCP) or demineralized bovine bone mineral (DBBM) with and without 0.3 mg/ml recombinant PDGF-BB. Calvaria defects were randomly divided into the following treatment groups (n = 5); TCP; TCP plus PDGF-BB; DBBM; DBBM plus PDGF-BB; and untreated empty control. After 45 days, bone formation was evaluated by histomorphometry and fluorescence microscopy. The authors report that the area of newly formed bone was similar between the empty controls and the two bone substitutes, TCP and DBBM. Supplementation of TCP and DBBM with PDGF-BB had no significant impact on bone formation. Fluorochrome staining revealed no visible changes in the pattern of bone formation in defects filled with TCP and DBBM, irrespective of PDGF-BB. Furthermore, supplementation with PDGF-BB did not influence biomaterial degradation. The authors concluded that PDGF-BB had no impact on bone formation and degradation of bone substitutes in the respective rodent models. Thus, possible beneficial effects of PDGF-BB may require other model situations.

  16. Controlled Release of Granulocyte Colony-Stimulating Factor Enhances Osteoconductive and Biodegradable Properties of Beta-Tricalcium Phosphate in a Rat Calvarial Defect Model

    Directory of Open Access Journals (Sweden)

    Tomohiro Minagawa

    2014-01-01

    Full Text Available Autologous bone grafts remain the gold standard for the treatment of congenital craniofacial disorders; however, there are potential problems including donor site morbidity and limitations to the amount of bone that can be harvested. Recent studies suggest that granulocyte colony-stimulating factor (G-CSF promotes fracture healing or osteogenesis. The purpose of the present study was to investigate whether topically applied G-CSF can stimulate the osteoconductive properties of beta-tricalcium phosphate (β-TCP in a rat calvarial defect model. A total of 27 calvarial defects 5 mm in diameter were randomly divided into nine groups, which were treated with various combinations of a β-TCP disc and G-CSF in solution form or controlled release system using gelatin hydrogel. Histologic and histomorphometric analyses were performed at eight weeks postoperatively. The controlled release of low-dose (1 μg and 5 μg G-CSF significantly enhanced new bone formation when combined with a β-TCP disc. Moreover, administration of 5 μg G-CSF using a controlled release system significantly promoted the biodegradable properties of β-TCP. In conclusion, the controlled release of 5 μg G-CSF significantly enhanced the osteoconductive and biodegradable properties of β-TCP. The combination of G-CSF slow-release and β-TCP is a novel and promising approach for treating pediatric craniofacial bone defects.

  17. Combination of calcium sulfate and simvastatin-controlled release microspheres enhances bone repair in critical-sized rat calvarial bone defects

    Directory of Open Access Journals (Sweden)

    Fu YC

    2015-12-01

    Full Text Available Yin-Chih Fu,1–4 Yan-Hsiung Wang,1,5 Chung-Hwan Chen,1,3,4 Chih-Kuang Wang,1,6 Gwo-Jaw Wang,1,3,4 Mei-Ling Ho1,3,7,8 1Orthopaedic Research Center, 2Graduate Institute of Medicine, 3Department of Orthopaedics, 4Department of Orthopaedics, College of Medicine, 5School of Dentistry, College of Dental Medicine, 6Department of Medicinal and Applied Chemistry, 7Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 8Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, TaiwanAbstract: Most allogenic bone graft substitutes have only osteoconductive properties. Developing new strategies to improve the osteoinductive activity of bone graft substitutes is both critical and practical for clinical application. Previously, we developed novel simvastatin-encapsulating poly(lactic-co-glycolic acid microspheres (SIM/PLGA that slowly release simvastatin and enhance fracture healing. In this study, we combined SIM/PLGA with a rapidly absorbable calcium sulfate (CS bone substitute and studied the effect on bone healing in critical-sized calvarial bone defects in a rat model. The cytotoxicity and cytocompatibility of this combination was tested in vitro using lactate dehydrogenase leakage and a cell attachment assay, respectively. Combination treatment with SIM/PLGA and the CS bone substitute had no cytotoxic effect on bone marrow stem cells. Compared with the control, cell adhesion was substantially enhanced following combination treatment with SIM/PLGA and the CS bone substitute. In vivo, implantation of the combination bone substitute promoted healing of critical-sized calvarial bone defects in rats; furthermore, production of bone morphogenetic protein-2 and neovascularization were enhanced in the area of the defect. In summary, the combination of SIM/PLGA and a CS bone substitute has osteoconductive and osteoinductive properties, indicating that it could be used for regeneration

  18. Histologic Evaluation of Osseous Regeneration Following Combination Therapy With Platelet-Rich Plasma and Bio-Oss in a Rat Calvarial Critical-Size Defect Model.

    Science.gov (United States)

    DeNicolo, Philip J; Guyton, M Kelly; Cuenin, Michael F; Hokett, Steven D; Sharawy, Mohamed; Borke, James; McPherson, James C

    2015-10-01

    Platelet-rich plasma (PRP) is an autogenous source of growth factors shown to facilitate human bone growth. Bio-Oss, an osteoconductive xenograft, is used clinically to regenerate periodontal defects, restore dental alveolar ridges, and facilitate sinus-lift procedures. The purpose of this study was to analyze whether a combination of PRP and Bio-Oss would enhance bone regeneration better than either material alone. PRP and/or Bio-Oss were administered in an 8-mm critical-size defect (CSD) rat calvarial model of bone defect between 2 polytetrafluoroethylene membranes to prevent soft tissue incursion. Eight weeks after the induction of the CSD, histologic sections were stained with hematoxylin and eosin stain and analyzed via light microscopy. Qualitative analyses revealed new bone regeneration in all 4 groups. The Bio-Oss and PRP plus Bio-Oss groups demonstrated greater areas of closure in the defects than the control or PRP-only groups because of the space-maintaining ability of Bio-Oss. The groups grafted with Bio-Oss showed close contact with new bone growth throughout the defects, suggesting a stronger graft. The use of PRP alone or in combination with Bio-Oss, however, did not appear to enhance osseous regeneration at 8 weeks. Areas grafted with Bio-Oss demonstrated greater space-maintaining capacity than controls, and PRP was an effective vehicle for placement of the Bio-Oss. However, at 8 weeks this study was unable to demonstrate a significant advantage of using PRP plus Bio-Oss over using Bio-Oss alone.

  19. A Comparative Histological Study of Bone Healing in Rat Calvarial Defect Using the Erbium-Doped Yttrium Aluminum Garnet Laser and Rotary Instruments

    Science.gov (United States)

    Jung, Mi-Kyung; Kim, Su-Gwan; Oh, Ji-Su; Jin, Seung-Chan; Lee, Sook-Young; Jang, Eun-Sook; Piao, Zheng-Gang; Lim, Sung-Chul; Jeong, Mi-Ae

    2012-01-01

    Erbium-doped yttrium aluminum garnet (Er:YAG) lasers have been used in dentistry for cutting bone and removal of caries. The purpose of this study was to evaluate the bone healing in a skull defect prepared in rats using various instruments including Er:YAG laser. The 7 mm calvarial defects were created in 45 rats and 45 rats were divided into three groups (n = 15): a high-speed rotation engine with carbide round bur (2-mm diameter), a low-speed rotation engine with carbide round bur (2-mm diameter), and an Er:YAG laser. Specimens obtained after 3 days or 4 or 8 weeks were submitted for histological analysis. Three days after surgery, no bone formation had occurred in any of the groups. Four weeks after surgery, 90 ±8.16% new bone formation was observed in the high-speed group, and 8 weeks after surgery, 100 ±0% new bone formation was observed in the low- and high-speed groups. There were significant differences among the periods after surgery, but no significant differences were observed among final results with in different device groups.

  20. Osteointegration of Porous Poly-ε-Caprolactone-Coated and Previtalised Magnesium Implants in Critically Sized Calvarial Bone Defects in the Mouse Model

    Directory of Open Access Journals (Sweden)

    Michael Grau

    2017-12-01

    Full Text Available Metallic biomaterials are widely used in maxillofacial surgery. While titanium is presumed to be the gold standard, magnesium-based implants are a current topic of interest and investigation due to their biocompatible, osteoconductive and degradable properties. This study investigates the effects of poly-ε-caprolactone-coated and previtalised magnesium implants on osteointegration within murine calvarial bone defects: After setting a 3 mm × 3 mm defect into the calvaria of 40 BALB/c mice the animals were treated with poly-ε-caprolactone-coated porous magnesium implants (without previtalisation or previtalised with either osteoblasts or adipose derived mesenchymal stem cells, porous Ti6Al4V implants or without any implant. To evaluate bone formation and implant degradation, micro-computertomographic scans were performed at day 0, 28, 56 and 84 after surgery. Additionally, histological thin sections were prepared and evaluated histomorphometrically. The outcomes revealed no significant differences within the differently treated groups regarding bone formation and the amount of osteoid. While the implant degradation resulted in implant shifting, both implant geometry and previtalisation appeared to have positive effects on vascularisation. Although adjustments in degradation behaviour and implant fixation are indicated, this study still considers magnesium as a promising alternative to titanium-based implants in maxillofacial surgery in future.

  1. Bone Regeneration Using a Mixture of Silicon-Substituted Coral HA and β-TCP in a Rat Calvarial Bone Defect Model

    Directory of Open Access Journals (Sweden)

    Jiyeon Roh

    2016-02-01

    Full Text Available The demand of bone graft materials has been increasing. Among various origins of bone graft materials, natural coral composed of up to 99% calcium carbonate was chosen and converted into hydroxyapatite (HA; silicon was then substituted into the HA. Then, the Si-HA was mixed with β-tricalcium phosphate (TCP in the ratios 100:0 (S100T0, 70:30 (S70T30, 60:40 (S60T40, and 50:50 (S50T50. The materials were implanted for four and eight weeks in a rat calvarial bone defect model (8 mm. The MBCPTM (HA:β-TCP = 60:40, Biomatalante, Vigneux de Bretagne, France was used as a control. After euthanasia, the bone tissue was analyzed by making histological slides. From the results, S60T40 showed the fastest bone regeneration in four weeks (p < 0.05. In addition, S60T40, S50T50, and MBCPTM showed significant new bone formation in eight weeks (p < 0.05. In conclusion, Si-HA/TCP showed potential as a bone graft material.

  2. Mesenchymal stem cell expression of SDF-1β synergizes with BMP-2 to augment cell-mediated healing of critical-sized mouse calvarial defects.

    Science.gov (United States)

    Herberg, Samuel; Aguilar-Perez, Alexandra; Howie, R Nicole; Kondrikova, Galina; Periyasamy-Thandavan, Sudharsan; Elsalanty, Mohammed E; Shi, Xingming; Hill, William D; Cray, James J

    2017-06-01

    Bone has the potential for spontaneous healing. This process, however, often fails in patients with comorbidities. Tissue engineering combining functional cells, biomaterials and osteoinductive cues may provide alternative treatment strategies. We have recently demonstrated that stromal cell-derived factor-1β (SDF-1β) works in concert with bone morphogenetic protein-2 (BMP-2) to potentiate osteogenic differentiation of bone marrow-derived mesenchymal stem/stromal cells (BMSCs). Here, we test the hypothesis that SDF-1β overexpressed in Tet-Off-SDF-1β BMSCs, delivered on acellular dermal matrix (ADM), synergistically augments BMP-2-induced healing of critical-sized mouse calvarial defects. BMSC therapies alone showed limited bone healing, which was increased with co-delivery of BMP-2. This was further enhanced in Tet-Off-SDF-1β BMSCs + BMP-2. Only limited BMSC retention on ADM constructs was observed after 4 weeks in vivo, which was increased with BMP-2 co-delivery. In vitro cell proliferation studies showed that supplementing BMP-2 to Tet-Off BMSCs significantly increased the cell number during the first 24 h. Consequently, the increased cell numbers decreased the detectable BMP-2 levels in the medium, but increased cell-associated BMP-2. The data suggest that SDF-1β provides synergistic effects supporting BMP-2-induced, BMSC-mediated bone formation and appears suitable for optimization of bone augmentation in combination therapy protocols. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Low-Dose Bone Morphogenetic Protein-2/Stromal Cell-Derived Factor-1β Cotherapy Induces Bone Regeneration in Critical-Size Rat Calvarial Defects

    Science.gov (United States)

    Herberg, Samuel; Susin, Cristiano; Pelaez, Manuel; Howie, R. Nicole; Moreno de Freitas, Rubens; Lee, Jaebum; Cray, James J.; Johnson, Maribeth H.; Elsalanty, Mohammed E.; Hamrick, Mark W.; Isales, Carlos M.; Wikesjö, Ulf M.E.

    2014-01-01

    Increasing evidence suggests that stromal cell-derived factor-1 (SDF-1/CXCL12) is involved in bone formation, though underlying molecular mechanisms remain to be fully elucidated. Also, contributions of SDF-1β, the second most abundant splice variant, as an osteogenic mediator remain obscure. We have shown that SDF-1β enhances osteogenesis by regulating bone morphogenetic protein-2 (BMP-2) signaling in vitro. Here we investigate the dose-dependent contribution of SDF-1β to suboptimal BMP-2-induced local bone formation; that is, a dose that alone would be too low to significantly induce bone formation. We utilized a critical-size rat calvarial defect model and tested the hypotheses that SDF-1β potentiates BMP-2 osteoinduction and that blocking SDF-1 signaling reduces the osteogenic potential of BMP-2 in vivo. In preliminary studies, radiographic analysis at 4 weeks postsurgery revealed a dose-dependent relationship in BMP-2-induced new bone formation. We then found that codelivery of SDF-1β potentiates suboptimal BMP-2 (0.5 μg) osteoinduction in a dose-dependent order, reaching comparable levels to the optimal BMP-2 dose (5.0 μg) without apparent adverse effects. Blocking the CXC chemokine receptor 4 (CXCR4)/SDF-1 signaling axis using AMD3100 attenuated the osteoinductive potential of the optimal BMP-2 dose, confirmed by qualitative histologic analysis. In conclusion, SDF-1β provides potent synergistic effects that support BMP-induced local bone formation and thus appears a suitable candidate for optimization of bone augmentation using significantly lower amounts of BMP-2 in spine, orthopedic, and craniofacial settings. PMID:24341891

  4. Evaluation of appreciable filling defect in thyroid scan

    International Nuclear Information System (INIS)

    Kim, H. K.; Kim, C. K.; Choe, Y. K.; Choi, B. S.

    1973-01-01

    A summary of various data of the thyroid function test and clinical and pathological findings over 94 patients who have appreciable filling defect on their thyroid scan, among 860 patients received thyroid function tests due to suspected thyroid diseases at the Radiology and Nuclear Medicine, College of Medicine, Yonsei University, was discussed and evaluated. 1. The incidence of cold nodule in female is about 9.5 times more frequent than in male, and the majority of patients (72.3%) were in the 2nd through 3rd decades. 2. The cold nodules are more distributed in right lobe (60.0%) than in left lobe and more distributed in lower portions of both lobes (54.2%) than in middle and upper portions. 3. The clinical symptoms supporting the evaluation of thyroid functional state in various thyroid diseases are not helpful for patients with cold nodules. 4. Considering the mean values of various thyroid function tests of patients with cold nodules, the value of 1-131 thyroid uptake test is in lower limit of normal range, the value of T 3 -RBC uptake test in normal range, and the value of PBI test in upper limit of normal range. 5. Considering the filling defect portion on thyroid scan by cold nodule as fraction, in the case of involving entire one lobe the values of all thyroid function tests are more meaningfully decreased than in order cases but the case of involving more than half an lobe to one lobe compared with the case of involving less than half a lobe, the values of thyroid uptake tests are not meaningfully changed but the values of T 3 -RBC uptake tests or PBI tests are moreover increased in the former

  5. Sandwich-type PLLA-nanosheets loaded with BMP-2 induce bone regeneration in critical-sized mouse calvarial defects.

    Science.gov (United States)

    Huang, Kuo-Chin; Yano, Fumiko; Murahashi, Yasutaka; Takano, Shuta; Kitaura, Yoshiaki; Chang, Song Ho; Soma, Kazuhito; Ueng, Steve W N; Tanaka, Sakae; Ishihara, Kazuhiko; Okamura, Yosuke; Moro, Toru; Saito, Taku

    2017-09-01

    To overcome serious clinical problems caused by large bone defects, various approaches to bone regeneration have been researched, including tissue engineering, biomaterials, stem cells and drug screening. Previously, we developed a free-standing biodegradable polymer nanosheet composed of poly(L-lactic acid) (PLLA) using a simple fabrication process consisting of spin-coating and peeling techniques. Here, we loaded recombinant human bone morphogenetic protein-2 (rhBMP-2) between two 60-nm-thick PLLA nanosheets, and investigated these sandwich-type nanosheets in bone regeneration applications. The PLLA nanosheets displayed constant and sustained release of the loaded rhBMP-2 for over 2months in vitro. Moreover, we implanted the sandwich-type nanosheets with or without rhBMP-2 into critical-sized defects in mouse calvariae. Bone regeneration was evident 4weeks after implantation, and the size and robustness of the regenerated bone had increased by 8weeks after implantation in mice implanted with the rhBMP-2-loaded nanosheets, whereas no significant bone formation occurred over a period of 20weeks in mice implanted with blank nanosheets. The PLLA nanosheets loaded with rhBMP-2 may be useful in bone regenerative medicine; furthermore, the sandwich-type PLLA nanosheet structure may potentially be applied as a potent prolonged sustained-release carrier of other molecules or drugs. Here we describe sandwich-type poly(L-lactic acid) (PLLA) nanosheets loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) as a novel method for bone regeneration. Biodegradable 60-nm-thick PLLA nanosheets display strong adhesion without any adhesive agent. The sandwich-type PLLA nanosheets displayed constant and sustained release of the loaded rhBMP-2 for over 2months in vitro. The nanosheets with rhBMP-2 markedly enhanced bone regeneration when they were implanted into critical-sized defects in mouse calvariae. In addition to their application for bone regeneration, PLLA

  6. BMP2 genetically engineered MSCs and EPCs promote vascularized bone regeneration in rat critical-sized calvarial bone defects.

    Directory of Open Access Journals (Sweden)

    Xiaoning He

    Full Text Available Current clinical therapies for critical-sized bone defects (CSBDs remain far from ideal. Previous studies have demonstrated that engineering bone tissue using mesenchymal stem cells (MSCs is feasible. However, this approach is not effective for CSBDs due to inadequate vascularization. In our previous study, we have developed an injectable and porous nano calcium sulfate/alginate (nCS/A scaffold and demonstrated that nCS/A composition is biocompatible and has proper biodegradability for bone regeneration. Here, we hypothesized that the combination of an injectable and porous nCS/A with bone morphogenetic protein 2 (BMP2 gene-modified MSCs and endothelial progenitor cells (EPCs could significantly enhance vascularized bone regeneration. Our results demonstrated that delivery of MSCs and EPCs with the injectable nCS/A scaffold did not affect cell viability. Moreover, co-culture of BMP2 gene-modified MSCs and EPCs dramatically increased osteoblast differentiation of MSCs and endothelial differentiation of EPCs in vitro. We further tested the multifunctional bone reconstruction system consisting of an injectable and porous nCS/A scaffold (mimicking the nano-calcium matrix of bone and BMP2 genetically-engineered MSCs and EPCs in a rat critical-sized (8 mm caviarial bone defect model. Our in vivo results showed that, compared to the groups of nCS/A, nCS/A+MSCs, nCS/A+MSCs+EPCs and nCS/A+BMP2 gene-modified MSCs, the combination of BMP2 gene -modified MSCs and EPCs in nCS/A dramatically increased the new bone and vascular formation. These results demonstrated that EPCs increase new vascular growth, and that BMP2 gene modification for MSCs and EPCs dramatically promotes bone regeneration. This system could ultimately enable clinicians to better reconstruct the craniofacial bone and avoid donor site morbidity for CSBDs.

  7. Inkjet-based biopatterning of SDF-1β augments BMP-2-induced repair of critical size calvarial bone defects in mice.

    Science.gov (United States)

    Herberg, Samuel; Kondrikova, Galina; Periyasamy-Thandavan, Sudharsan; Howie, R Nicole; Elsalanty, Mohammed E; Weiss, Lee; Campbell, Phil; Hill, William D; Cray, James J

    2014-10-01

    A major problem in craniofacial surgery is non-healing bone defects. Autologous reconstruction remains the standard of care for these cases. Bone morphogenetic protein-2 (BMP-2) therapy has proven its clinical utility, although non-targeted adverse events occur due to the high milligram-level doses used. Ongoing efforts explore the use of different growth factors, cytokines, or chemokines, as well as co-therapy to augment healing. Here we utilize inkjet-based biopatterning to load acellular DermaMatrix delivery matrices with nanogram-level doses of BMP-2, stromal cell-derived factor-1β (SDF-1β), transforming growth factor-β1 (TGF-β1), or co-therapies thereof. We tested the hypothesis that bioprinted SDF-1β co-delivery enhances BMP-2 and TGF-β1-driven osteogenesis both in-vitro and in-vivo using a mouse calvarial critical size defect (CSD) model. Our data showed that BMP-2 bioprinted in low-doses induced significant new bone formation by four weeks post-operation. TGF-β1 was less effective compared to BMP-2, and SDF-1β therapy did not enhance osteogenesis above control levels. However, co-delivery of BMP-2+SDF-1β was shown to augment BMP-2-induced bone formation compared to BMP-2 alone. In contrast, co-delivery of TGF-β1+SDF-1β decreased bone healing compared to TGF-β1 alone. This was further confirmed in vitro by osteogenic differentiation studies using MC3T3-E1 pre-osteoblasts. Our data indicates that sustained release delivery of a low-dose growth factor therapy using biopatterning technology can aid in healing CSD injuries. SDF-1β augments the ability for BMP-2 to drive healing, a result confirmed in vivo and in vitro; however, because SDF-1β is detrimental to TGF-β1-driven osteogenesis, its effect on osteogenesis is not universal. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Radiographic and ultrasonographic features of uroliths and other urinary tract filling defects

    International Nuclear Information System (INIS)

    Johnston, G.R.; Walter, P.A.; Feeney, D.A.

    1986-01-01

    Radiopaque uroliths and nonradiopaque (water density) uroliths are filling defects encountered in the urinary tracts of dogs and cats. Other free luminal and attached soft tissue density filling defects encountered during uroradiographic special procedures include blood clots, air bubbles, hematomas, granulomas, abscesses, inflammatory and neoplastic polyps. Nonradiopaque uroliths cannot be identified on survey radiographs from other soft tissue dense structures. Gray scale ultrasonography can be used to differentiate nonradiopaque (water dense) uroliths from other soft tissue attached or free luminal filling defects of the excretory pathway. The differential radiographic features of filling defects encountered during cystography and urethrography are described and illustrated

  9. Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo micro-computed tomographic and histologic experiment in rats

    Science.gov (United States)

    Al-Hezaimi, Khalid; Ramalingam, Sundar; Al-Askar, Mansour; ArRejaie, Aws S; Nooh, Nasser; Jawad, Fawad; Aldahmash, Abdullah; Atteya, Muhammad; Wang, Cun-Yu

    2016-01-01

    The aim of the present real time in vivo micro-computed tomography (µCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial critical size defects (CSD) using bone marrow-derived mesenchymal stem cells (BMSCs), and collagen membrane (CM) with and without tricalcium phosphate (TCP) graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD (diameter 4.6 mm) were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone (NFB) and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo µCT. At the 10th week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups 1 and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical “lock” between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy. PMID:27025260

  10. Computed tomography angiography intraluminal filling defect is predictive of internal carotid artery free-floating thrombus

    Energy Technology Data Exchange (ETDEWEB)

    Jaberi, A.; Lum, C.; Stefanski, P.; Iancu, D. [University of Ottawa, Faculty of Medicine, Ottawa, Ontario (Canada); The Ottawa Hospital, Department of Radiology, Neuroradiology Section, Ottawa, Ontario (Canada); Thornhill, R. [Neurosciences and Clinical Epidemiology Program/Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario (Canada); The Ottawa Hospital, Department of Radiology, Neuroradiology Section, Ottawa, Ontario (Canada); Petrcich, W. [Neurosciences and Clinical Epidemiology Program/Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario (Canada); Momoli, F. [Children' s Hospital of Eastern Ontario Research Institute, Ottawa, Ontario (Canada); University of Ottawa, Department of Epidemiology and Community Medicine, Ottawa, Ontario (Canada); Torres, C.; Dowlatshahi, D. [University of Ottawa, Faculty of Medicine, Ottawa, Ontario (Canada); University of Ottawa, Division of Neurology, Department of Medicine, Ottawa, Ontario (Canada)

    2014-01-15

    Filling defects at the internal carotid artery (ICA) origin in the work-up of stroke or transient ischemic attack may be an ulcerated plaque or free-floating thrombus (FFT). This may be challenging to distinguish, as they can appear morphologically similar. This is an important distinction as FFT can potentially embolize distally, and its management differs. We describe a series of patients with suspected FFT and evaluate its imaging appearance, clinical features, and evolution with therapy. Between 2008 and 2013, we prospectively collected consecutive patients with proximal ICA filling defects in the axial plane surrounded by contrast on CT/MR angiography. We defined FFT as a filling defect that resolved on follow-up imaging. We assessed the cranial-caudal dimension of the filling defect and receiver operating characteristics to identify clinical and radiological variables that distinguished FFT from complex ulcerated plaque. Intraluminal filling defects were identified in 32 patients. Filling defects and resolved or decreased in 25 patients (78 %) and felt to be FFT; there was no change in 7 (22 %). Resolved defects and those that decreased in size extended more cranially than those that remained unchanged: 7.3 mm (4.2-15.9) versus 3.1 mm (2.7-3.7; p = 0.0038). Receiver operating characteristic analysis established a threshold of 3.8 mm (filling defect length), sensitivity of 88 %, specificity of 86 %, and area under the curve of 0.86 (p < 0.0001) for distinguishing FFT from plaque. Filling defects in the proximal ICA extending cranially >3.8 mm were more likely to be FFT than complex ulcerated plaque. Further studies evaluating filling defect length as a predictor for FFT are warranted. (orig.)

  11. Computed tomography angiography intraluminal filling defect is predictive of internal carotid artery free-floating thrombus

    International Nuclear Information System (INIS)

    Jaberi, A.; Lum, C.; Stefanski, P.; Iancu, D.; Thornhill, R.; Petrcich, W.; Momoli, F.; Torres, C.; Dowlatshahi, D.

    2014-01-01

    Filling defects at the internal carotid artery (ICA) origin in the work-up of stroke or transient ischemic attack may be an ulcerated plaque or free-floating thrombus (FFT). This may be challenging to distinguish, as they can appear morphologically similar. This is an important distinction as FFT can potentially embolize distally, and its management differs. We describe a series of patients with suspected FFT and evaluate its imaging appearance, clinical features, and evolution with therapy. Between 2008 and 2013, we prospectively collected consecutive patients with proximal ICA filling defects in the axial plane surrounded by contrast on CT/MR angiography. We defined FFT as a filling defect that resolved on follow-up imaging. We assessed the cranial-caudal dimension of the filling defect and receiver operating characteristics to identify clinical and radiological variables that distinguished FFT from complex ulcerated plaque. Intraluminal filling defects were identified in 32 patients. Filling defects and resolved or decreased in 25 patients (78 %) and felt to be FFT; there was no change in 7 (22 %). Resolved defects and those that decreased in size extended more cranially than those that remained unchanged: 7.3 mm (4.2-15.9) versus 3.1 mm (2.7-3.7; p = 0.0038). Receiver operating characteristic analysis established a threshold of 3.8 mm (filling defect length), sensitivity of 88 %, specificity of 86 %, and area under the curve of 0.86 (p 3.8 mm were more likely to be FFT than complex ulcerated plaque. Further studies evaluating filling defect length as a predictor for FFT are warranted. (orig.)

  12. A magnetically tunable non-Bragg defect mode in a corrugated waveguide filled with liquid crystals

    Science.gov (United States)

    Zhang, Lu; Fan, Ya-Xian; Liu, Huan; Han, Xu; Lu, Wen-Qiang; Tao, Zhi-Yong

    2018-04-01

    A magnetically tunable, non-Bragg defect mode (NBDM) was created in the terahertz frequency range by inserting a defect in the middle of a periodically corrugated waveguide filled with liquid crystals (LCs). In the periodic waveguide, non-Bragg gaps beyond the Bragg ones, which appear in the transmission spectra, are created by different transverse mode resonances. The transmission spectra of the waveguide containing a defect showed that a defect mode was present inside the non-Bragg gap. The NBDM has quite different features compared to the Bragg defect mode, which includes more complex, high-order guided wave modes. In our study, we filled the corrugated waveguide with LCs to realize the tunability of the NBDM. The simulated results showed that the NBDM in a corrugated waveguide filled with LCs can be used in filters, sensors, switches, and other terahertz integrated devices.

  13. [Calvarial reconstruction by customized bioactive implant].

    Science.gov (United States)

    Probst, F A; Hutmacher, D W; Müller, D F; Machens, H-G; Schantz, J-T

    2010-12-01

    Osseous craniofacial defects are commonly seen problems after operative treatment of craniosynostoses. This case report describes a calvarial reconstruction by means of computer-aided fabrication of a customised implant. Three-dimensional imaging is followed by computer-aided design and fabrication of a medical grade PCL-TCP biodegradable scaffold using the rapid prototyping technology fused deposition modelling (CAD/CAM). After six months the implant was well integrated, no defect area could be palpated any more and a beginning bony consolidation could be detected via CT. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Radiologic analysis of cecal filling defects and local wall displacement

    International Nuclear Information System (INIS)

    Kim, D. I.; Suh, J. S.; Kim, G. E.; Park, C. Y.

    1981-01-01

    It has long been accepted that cecum and ileocecal valve are prime important area in GI roentgenology because of variety and frequency of primary and secondary disease involvement. However, precise preoperative diagnosis is still debatable roentrenologically. It is necessary to use the more descriptive terms and systemic approach for roentgenologic diagnosis in this area. Authors analyzed pathologically verified 54 cases of cecal lesion by double contrast colon examination at Yonsei University Medical College Severance Hospital from January '75 to September '80. Of the distribution of diseases, pericecal abscess (16/54; 29.6%) was most common, and followed by intestinal tuberculosis (9/54; 16.6%), and carcinoma (9/54; 16.6%) etc. The ratio of male and female was 2.18: 1 and peak incidence was above 4th decade. The majority of cases show right lower quadrant pain and palpable mass as clinical manifestation. Of the radiologic findings, abnormality in appendix such as nonfilling or irregular filling of barium suggest pericecal abscess, mucocele and less frequently adenocarcinoma of cecum, and characteristically pericecal abscess show rather smooth displacement of medial wall of cecum, but abrupt transition of lesion is shown in adenocarcinoma. Irritability and shortening of cecum, and fixation and speculation of terminal ileum were frequently found in inflammatory conditions such as pericecal abscess, intestinal tuberculosis and chronic nonspecific inflammation. Cecal lesion associated with involvement of ileocecal value were noted in intestinal tuberculosis, lymphoma and adenocarcinoma

  15. Split calvarial graft and titanium mesh for reconstruction of post ...

    African Journals Online (AJOL)

    Background: The goal of cranioplasty is to achieve a lifelong, stable and structural reconstruction of the cranium covered by a healthy skin and scalp flap. We present two cases of large frontal bone defect following a accident.. Cases: We describe the utilization of autogenous local split calvarial graft and titanium mesh for ...

  16. The effects of dental pulp stem cells on bone regeneration in rat calvarial defect model: micro-computed tomography and histomorphometric analysis.

    Science.gov (United States)

    Asutay, Fatih; Polat, Serkan; Gül, Mehmet; Subaşı, Cansu; Kahraman, Sevil Altundağ; Karaöz, Erdal

    2015-12-01

    Stem cell therapies may be applicable to all fields of medicine, including craniomaxillofacial surgery. Dental pulp stem cells also have significant osteogenic properties. This study aimed to evaluate the influence of dental pulp stem cells on bone regeneration and to ascertain whether or not there was any superiority over traditional methods. In this study, 15 non-immunodeficient Wistar albino rats were used. The rats were divided into three groups: (1) untreated control group; (2) hydroxyapatite tri-calcium-phosphate (HA/TCP) paste; (3) human dental pulp derived stem cells (DPSC) mixed with HA/TCP paste (HA/TCP+DSPC group, n=10). Two symmetrical full-thickness cranial defects were created on each parietal region (10 defects for each group). The animals were sacrificed 8 weeks post-surgery and samples were analyzed by microcomputer tomography (μ-CT) and histomorphometry. The calcification rate and bone mineral density (BMD) values in Group 3 were found to be significantly higher than in the other two groups. Radiographically, bone regeneration was greater in Group 2 compared with the control group. However, there was no significant difference between Groups 2 and 1 in respect of histological analysis. According to the results of the present study, DPSCs may be a suitable factor for bone tissue engineering because they can be easily obtained and differentiate into bone cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Extensive calvarial exposure and full thickness sequestration ...

    African Journals Online (AJOL)

    Background: Calvarial osteomyelitis is an uncommon complication of burn injury due to electricity. Patient: A case of electrical injury that progressed from full thickness scalp loss to calvarial osteomyelitis and sequestration of outer and inner tables seen after one year of calvarial exposure is presented. Result: The patient ...

  18. Effect of copper-doped silicate 13–93 bioactive glass scaffolds on the response of MC3T3-E1 cells in vitro and on bone regeneration and angiogenesis in rat calvarial defects in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yinan; Xiao, Wei [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Bal, B. Sonny [Department of Orthopaedic Surgery, University of Missouri, Columbia, MO 65212 (United States); Rahaman, Mohamed N., E-mail: rahaman@mst.edu [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States)

    2016-10-01

    The release of inorganic ions from biomaterials could provide an alternative approach to the use of growth factors for improving tissue healing. In the present study, the release of copper (Cu) ions from bioactive silicate (13–93) glass scaffolds on the response of cells in vitro and on bone regeneration and angiogenesis in vivo was studied. Scaffolds doped with varying concentrations of Cu (0–2.0 wt.% CuO) were created with a grid-like microstructure by robotic deposition. When immersed in simulated body fluid in vitro, the Cu-doped scaffolds released Cu ions into the medium in a dose-dependent manner and converted partially to hydroxyapatite. The proliferation and alkaline phosphatase activity of pre-osteoblastic MC3T3-E1 cells cultured on the scaffolds were not affected by 0.4 and 0.8 wt.% CuO in the glass but they were significantly reduced by 2.0 wt.% CuO. The percent new bone that infiltrated the scaffolds implanted for 6 weeks in rat calvarial defects (46 ± 8%) was not significantly affected by 0.4 or 0.8 wt.% CuO in the glass whereas it was significantly inhibited (0.8 ± 0.7%) in the scaffolds doped with 2.0 wt.% CuO. The area of new blood vessels in the fibrous tissue that infiltrated the scaffolds increased with CuO content of the glass and was significantly higher for the scaffolds doped with 2.0 wt.% CuO. Loading the scaffolds with bone morphogenetic protein-2 (1 μg/defect) significantly enhanced bone infiltration and reduced fibrous tissue in the scaffolds. These results showed that doping the 13–93 glass scaffolds with up to 0.8 wt.% CuO did not affect their biocompatibility whereas 2.0 wt.% CuO was toxic to cells and detrimental to bone regeneration. - Highlights: • First study to evaluate Cu ion release from silicate (13-93) bioactive glass scaffolds on osteogenesis in vivo • Released Cu ions influenced bone regeneration in a dose dependent manner • Lower concentrations of Cu ions had little effect on bone regeneration • Cu ion

  19. Repair process of surgical defects filled with autogenous bone grafts in tibiae of diabetic rats

    Directory of Open Access Journals (Sweden)

    Jônatas Caldeira Esteves

    2008-10-01

    Full Text Available From a biological standpoint, the best material for reconstruction of bone defects is the autogenous bone graft. However, as tissue healing is affected under diabetic conditions, major changes might take place in the revascularization, incorporation, replacement and remodeling phases of the grafted area. The purpose of this study was to assess the bone healing process in surgical wounds prepared in tibiae of diabetic rats and filled with autogenous bone. Forty male rats (Rattus norvegicus albinus, Wistar were randomly assigned to receive an endovenous injection (penile vein of either citrate buffer solution (Group 1 - control; n=20 or streptozotocin dissolved in citrate buffer solution (35 mg/kg to induce diabetes (Group 2 - diabetic; n=20. After determination of glycemia, the animals were anesthetized and the anterolateral regions of the tibiae of both limbs were shaved, antisepsis was performed and longitudinal incisions were made in each limb. The tibiae were exposed and two 2mm-diameter surgical cavities were prepared: one in the right limb, filled with particulate autogenous bone and the other in the left limb, filled with blood clot. The animals were euthanized at 10 and 30 postoperative days. The anatomic pieces were obtained, submitted to laboratory processing and sections were stained by hematoxylin and eosin and Masson's Trichrome for histomorphologic and histometric analyses. In both groups, the wounds filled with autogenous bone graft showed better results than those filled with blood clot. The control group showed higher new bone formation in wounds filled with autogenous bone graft at 30 days than the diabetic group, but without statistical significance. It may be concluded that, in general, the new bone formation occurred with autogenous graft was quantitatively similar between control and diabetic groups and qualitatively better in the control group.

  20. Calcium phosphate ceramics as bone graft substitutes in filling bone tumor defects

    Directory of Open Access Journals (Sweden)

    Saikia K

    2008-01-01

    Full Text Available Background: Synthetic bio-inert materials are currently used as an alternative to autogenous bone graft. Calcium hydroxyapatite (HA and Beta tri-calcium phosphate (β-TCP, which belong to the calcium phosphate ceramics group, are biocompatible and osteo-conductive. The purpose of this study is to analyse the use of HA and β-TCP in their ceramic forms as a bone graft substitute in filling bone voids after curettage of benign bone tumors. Materials and Methods: Twenty-four patients in the age range of 3.5-55 years (mean 14.3 years having benign bone tumors with bone defects were filled with bone graft substitute following curettage. In 20 patients bone defects were filled with block/granules of HA ceramic and in four with β-TCP. Fibular strut graft was packed with HA in four patients. The patients were followed up for an average of 18 months (range 12-36 months. Results: The functional status of the patients at follow-up was evaluated and compared with preoperative functional status. Early incorporation of graft substitutes became evident radiologically between 6 and 10 weeks (Stage I. Complete incorporation (Stage III was observed in an average of nine months (6-18 months. Clinical healing was observed before radiological healing. The average time taken to return to preoperative function was 14 weeks. There was no recurrence of lesion or growth retardation. Conclusion: Calcium hydroxyapatite and β-TCP are excellent bone graft substitutes for autogenous bone graft in filling voids after curettage of benign bone tumors.

  1. Effects of partial La filling and Sb vacancy defects on CoS b3 skutterudites

    Science.gov (United States)

    Hu, Chongze; Zeng, Xiaoyu; Liu, Yufei; Zhou, Menghan; Zhao, Huijuan; Tritt, Terry M.; He, Jian; Jakowski, Jacek; Kent, Paul R. C.; Huang, Jingsong; Sumpter, Bobby G.

    2017-04-01

    Over the past decade, the open frame ("cagey") structure of CoS b3 skutterudite has invited intensive filling studies with various rare-earth elements for delivering state-of-the-art midtemperature thermoelectric performance. To rationalize previously reported experimental results and provide new insight into the underexplored roles of La fillers and Sb vacancies, ab initio density functional theory studies, along with semiclassical Boltzmann transport theory calculations, are performed for pristine CoS b3 of different lattice settings and La-filled CoS b3 with and without Sb's mono- and divacancy defects. The effects of spin-orbit coupling (SOC), partial La filling, Sb vacancy defects, and spin polarization on the electronic and thermoelectric properties are systematically examined. The SOC shows minor effects on the electronic and thermoelectric properties of CoS b3 . The peculiar quasi-Dirac band in the pristine CoS b3 largely survives La filling but not Sb vacancies, which instead introduce dispersive bands in the band gap region. The non-spin-polarized and spin-polarized solutions of La-filled CoS b3 are nearly degenerate. Importantly, the band structure, density of states, and Fermi surface of the latter are significantly spin polarized, giving rise to spin-dependent thermoelectric properties. Seebeck coefficients directly calculated as a function of chemical potential are interpreted in connection with the electronic structures. Temperature-dependent Seebeck coefficients derived for the experimentally studied materials agree well with available experimental data. Seebeck coefficients obtained as a function of charge carrier concentration corroborate the thermoelectrically favorable role at high filling fractions played by the Fermi electron pockets associated with the degenerate valleys in the conduction bands, and also point toward a similar role of the Fermi hole pockets associated with the degenerate hills in the valence bands. These results serve to

  2. Diffraction of electromagnetic waves by a metallic bar grating with a defect in dielectric filling of the slits

    Science.gov (United States)

    Kochetova, Lyudmila A.; Prosvirnin, Sergey L.

    2018-04-01

    The problem of electromagnetic wave diffraction by the metallic bar grating with inhomogeneous dielectric filling of each slit between bars has been investigated by using the mode matching technique. The transmission and the inner field distribution have been analyzed for the structure which has a single defect in the periodic filling of slits. Such periodic structures are of particular interest for applications in optics, as they have the ability to concentrate a strong inner electromagnetic field and are characterized by high-Q transmission resonances. We use a simple approach to control the width and location of the stopband of the structure by placing a defect in the periodic filling of the grating slits. As a result, we observe the narrow resonance of transmission in terms of stopband width of the defect-free grating and confinement of strong inner electromagnetic field. By changing the permittivity of the defect layer we can shift the frequency of the resonant transmission.

  3. A Novel Porcine Graft for Regeneration of Bone Defects

    Directory of Open Access Journals (Sweden)

    Eisner Salamanca

    2015-05-01

    Full Text Available Bone regeneration procedures require alternative graft biomaterials to those for autogenous bone. Therefore, we developed a novel porcine graft using particle sizes of 250–500 μm and 500–1000 μm in rabbit calvarial bone defects and compared the graft properties with those of commercial hydroxyapatite (HA/beta-tricalcium phosphate (β-TCP over eight weeks. Surgery was performed in 20 adult male New Zealand white rabbits. During a standardized surgical procedure, four calvarial critical-size defects of 5 mm diameter and 3 mm depth were prepared. The defects were filled with HA/β-TCP, 250–500 μm or 500–1000 μm porcine graft, and control defects were not filled. The animals were grouped for sacrifice at 1, 2, 4, and 8 weeks post-surgery. Subsequently, sample blocks were prepared for micro-computed tomography (micro-CT scanning and histological sectioning. Similar bone formations were observed in all three treatment groups, although the 250–500 μm porcine graft performed slightly better. Rabbit calvarial bone tissue positively responded to porcine grafts and commercial HA/β-TCP, structural analyses showed similar crystallinity and porosity of the porcine and HA/β-TCP grafts, which facilitated bone formation through osteoconduction. These porcine grafts can be considered as graft substitutes, although further development is required for clinical applications.

  4. Castor oil polyurethane containing silica nanoparticles as filling material of bone defect in rats.

    Science.gov (United States)

    Nacer, Renato Silva; Poppi, Rodrigo Ré; Carvalho, Paulo de Tarso Camilo de; Silva, Baldomero Antonio Kato da; Odashiro, Alexandre Nakao; Silva, Iandara Schettert; Delben, José Renato Jurkevicz; Delben, Angela Antonia Sanches Tardivo

    2012-01-01

    To evaluate the biologic behavior of the castor polymer containing silica nanoparticles as a bone substitute in diafisary defect. Twenty seven male Rattus norvegicus albinus Wistar lineage were submitted to bone defect filled with castor oil polymer. Three experimental groups had been formed with nine animals each: (1) castor oil polymer containing only calcium carbonate; (2) castor oil polymer with calcium carbonate and doped with 5% of silica nanoparticles; (3) castor polymer with calcium carbonate doped with 10% of silica nanoparticles; 3 animals of each group were submitted to euthanasia 15, 30 and 60 days after experimental procedure, and their femurs were removed to histological evaluation. there was bone growth in all the studied groups, with a greater tendency of growth in the group 1. After 30 days all the groups presented similar results. After 60 days a greater amount of fibroblasts, osteoblasts, osteocytes and osteoclasts in group 3 was observed, with integrated activity of 3 kinds of cells involved in the bone activation-reabsorption-formation. The castor polymer associated to the silica nanoparticles is biocompatible and allows osteoconduction. The presence of osteoprogenitors cells suggests silica osteoinduction capacity.

  5. [Bone defects in revision knee arthroplasty: filling with bone allograft plus platelet-derived growth factors].

    Science.gov (United States)

    Macule-Beneyto, Francisco; Segur-Vilalta, Josep; Vilchez-Cavazos, Felix; Esteban-Navarro, Pedro; Vidal-Sicart, Sergi; Acosta-Olivo, Carlos

    2014-01-01

    One of the most challenging aspects of a revision knee arthroplasty is the management of bone loss. The OBJECTIVE of the study is to show the capability to augment bone mineral density in areas with bone loss with platelet-derived growth factors. Randomized, prospective, blinded study in patients who underwent a total knee replacement revision with tibial-damaged metaphyseal bone were randomly allocated to have a revision total knee arthroplasty and to fill the bone defects with lyophilized bone allograft mixed with platelet growth factors (experimental group, n= 9) or with lyophilized bone allograft alone (control group, n= 7). To evaluate bone mineral density between groups, dual-energy X-ray absorptiometry (DEXA) was performed preoperatively, at 1 month, 6 months and 1 year after surgery. The study was comprised of a total of 16 patients. We found no significant differences observed during the follow-up between groups in mineral bone density. Use of platelet-derived growth factors does not improve bone mineral density in patients with revision knee arthroplasty.

  6. TCP is hardly resorbed and not osteoconductive in a non-loading calvarial model.

    Science.gov (United States)

    Handschel, Jörg; Wiesmann, Hans Peter; Stratmann, Udo; Kleinheinz, Johannes; Meyer, Ulrich; Joos, Ulrich

    2002-04-01

    Tricalciumphosphate (TCP) has been used as a ceramic bone substitute material in the orthopedic field as well as in craniofacial surgery. Some controversies exist concerning the osteoconductive potential of this material in different implantation sites. This study was designed to evaluate the biological response of calvarial bone towards TCP granules under non-loading conditions to assess the potential of TCP as a biodegredable and osteoconductive bone substitue material for the cranial vault. Full-thickness non-critical size defects were made bilaterally in the calvaria of 21 adult Wistar rats. One side was filled by TCP granules, the contralateral side was left empty and used as a control. Animals were sacrified in defined time intervals up to 6 months. Bone regeneration was analyzed with special respect toward the micromorphological and microanalytical features of the material-bone interaction by electron microscopy and electron diffraction analysis. Histologic examination revealed no TCP degradation even after 6 months of implantation. In contrast, a nearly complete bone regeneration of control defects was found after 6 months. At all times TCP was surrounded by a thin fibrous layer without presence of osteoblasts and features of regular mineralization. As far as degradation and substitution are concerned, TCP is a less favourable material tinder conditions of non-loading.

  7. Association of mesenchymal stem cells with platelet rich plasma on the repair of critical calvarial defects in mice Associação de células-tronco mesenquimais com plasma rico em plaquetas na reparação de defeitos críticos em calvária de camundongos

    Directory of Open Access Journals (Sweden)

    Betânia Souza Monteiro

    2012-03-01

    Full Text Available PURPOSE: To evaluate the effects of mesenchymal stem cells (MSC from eight mice C57BL/6 gfp+ bone marrows expanded in cultures associated with platelets rich plasma (PRP deriving from another eight mice, in the repair of critical defects in calvarial bone produced in twenty-four adult isogenic mice C57BL/6. METHODS: The animals were submitted to a cranial defect of 6.0mm in diameter and divided into two equal experimental groups. Control group did not receive treatment and the treated group received a MSC pellet containing 1.0 x 10(7 cells/mL associated with 50.0µL of plasma gel containing 1.0 x 10(9 autologous platelets within the defect. RESULTS: In the treated group was observed process of angiogenesis and bone repair better than control group. CONCLUSION: Mesenchymal stem cells derived from bone marrow of C57BL/6 gfp+ mice associated with PRP gel applied in bone critical defects produced in calvarial contributes positively to the process of bone repair.OBJETIVO: Avaliar os efeitos da associação das células-tronco mesenquimais (MSC oriundas da medula óssea de oito camundongos jovens C57BL/6 gfp+ e expandidas em culturas, com Plasma Rico em Plaquetas (PRP provenientes de outros oito camundongos, na reparação de defeitos críticos confeccionados em calvária de 24 camundongos adultos C57BL/6. MÉTODOS: Os animais foram submetidos a um defeito craniano de 6,0mm de diâmetro e separados em dois grupos experimentais iguais. O grupo controle não recebeu tratamento e no grupo tratado foi administrado, no interior do defeito, pellet de MSC contendo 1,0 x 10(7 células/mL associado com 50,0µL de plasma em gel autólogo contendo 1,0 x 10(9 plaquetas. RESULTADOS: No grupo tratado verificou-se processo de angiogênese e reparação óssea superior ao grupo controle. CONCLUSÃO: A associação das células-tronco mesenquimais (MSC derivadas da medula óssea de camundongos C57BL/6 gfp+ com gel de PRP aplicadas em defeitos ósseos cr

  8. Periapical bone defects of root filled teeth with persistent lesions evaluated by cone-beam computed tomography.

    Science.gov (United States)

    Yoshioka, T; Kikuchi, I; Adorno, C G; Suda, H

    2011-03-01

    To evaluate and categorize the bone defects of root filled teeth with persistent periapical lesions by cone-beam computed tomography (CBCT). Slice images of 532 teeth with persistent periapical lesions were obtained by CBCT in 427 patients and were examined by two endodontists. The periapical lesions were categorized into five types according to the characteristics of the bone defect based on CBCT images. The prevalence of each type was determined and analysed statistically at a 5% significance level using logistic regression. Of the 532 teeth analysed, 67% had buccal or labial bone plate defects (type II), 4% palatal or lingual bone plate defects (type III), 7%'through and through' defects (type IV) and 10% apical root protrusions from the bone plate (type V). Mandibular teeth had a significantly greater prevalence of type I lesions (P=0.0005) and a significantly lower prevalence for types IV (P=0.041), V (P=0.001), V-1 (P=0.015) and V-2 (Pperiapical bone defect in persistent lesions. Because 10% of the teeth had apical root protrusions, which could not be identified by periapical radiography, the diagnostic information obtained by CBCT was an essential component of the treatment planning process. © 2010 International Endodontic Journal.

  9. Dural enhancement with primary calvarial lesions.

    Science.gov (United States)

    Arana, E; Martí-Bonmatí, L; Ricart, V; Pérez-Ebrí, M

    2004-11-01

    The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

  10. Mechanical properties of the weld line defect in micro injection molding for various nano filled polypropylene composites

    International Nuclear Information System (INIS)

    Xie Lei; Ziegmann, Gerhard

    2011-01-01

    is increased to 30%, the E modulus and tensile strength of micro weld line were increased again compared with the low loading level. → Finally, an empirical prediction equation for micro injection molded weld line strength of nano PP composites was proposed for higher nano filler loading fraction than 10 wt%. - Abstract: The nano filled functional polymer materials have been widely processed with micro injection molding technology for micro electromechanical systems (MEMS) fabrication. As the unfavorable defect in micro injection molding parts, weld line brings reduced mechanical and physical properties, especially for nano filled composites. In this study, polypropylene (PP) was compounded respectively with carbon nano fibers (CNFs) and TiO 2 nano particles at various weight fractions (10, 20, 30, 35 wt%) through co-screws internal mixing. The morphological, thermal and rheological properties of nano composites were characterized by wider angle X-ray diffraction (WXRD), different scanning calorimeter (DSC) and high pressure capillary rheometer. Additionally, under the constant setting of injection molding process parameters in injection molding machine, micro tensile samples with weld lines for each nano filled PP composite were produced. The tensile tests were served as the characterizing method for weld line mechanical properties. The results show that when the CNFs is filled higher than 10 wt%, the tensile strength of samples with weld lines made of nano composites become lower than neat PP. While the raising CNFs content contributes to the improved E modulus of micro injection molded weld lines. Additionally, with the increasing fraction of CNFs in PP, the weld line area's elongation percent is decreased. Whereas for case of TiO 2 , the 10 wt% is the threshold for micro injection molded weld line tensile strength turning from decrease trend to increase. The same as CNFs, elongation of micro weld line samples were in general lower than neat PP as well, due to

  11. Uso da biocerâmica no preenchimento de falhas ósseas Use of bioceramics in filling bone defects

    Directory of Open Access Journals (Sweden)

    Carlos Antônio Garrido

    2010-01-01

    Full Text Available OBJETIVO: Apresentar os resultados encontrados com o uso da biocerâmica no preenchimento das falhas ósseas decorrentes de lesões traumáticas ou ortopédicas. MÉTODO: Foram avaliados 36 pacientes, portadores de falhas ósseas de etiologia pós-traumática ou ortopédica, 19 pacientes do sexo masculino (52,8% e 17 do sexo feminino (47,2%. A idade variou de 19 a 84 anos, com média de 45,7 anos e mediana de 37 anos. Foram incluídos apenas os pacientes com falhas que necessitaram, no mínimo, cinco gramas de biocerâmica. Foram classificadas como ortopédicas o total de 18 casos; as falhas ósseas observadas nas revisões de artroplastias totais do quadril, 11 casos; artroplastia total do quadril, primária, por coxartrose, um caso; osteotomias de fêmur ou tíbia de cunha aberta, cinco casos, e artrodese do tarso, um caso. Como falhas pós-traumática, 18 casos; as pseudoartroses não infectadas, oito casos; fraturas recentes do planalto tibial com compressão do osso esponjoso, três casos; fraturas expostas tratadas com fixadores externos, sete casos. A técnica cirúrgica utilizada foi o de curetar e desbridar a lesão até se encontrar osso de aspecto viável a enxertia, a seguir utilizou-se a biocerâmica para preenchimento da falha e algum tipo de fixação. RESULTADO: Dos 36 pacientes avaliados, observou-se que 35 (97,2% apresentaram integração da biocerâmica, um caso de fratura exposta tratada com fixador externo apresentou integração deficiente da biocerâmica. CONCLUSÃO: O tratamento de falhas ósseas de etiologia pós-traumática ou ortopédica, com o uso da cerâmica fosfocálcica composta de hidroxiapatita, se revelou um método prático, eficaz e seguro.OBJETIVE: To present the results of the use of biological ceramic in filling bone defects resulting from traumatic or orthopedic injuries. METHODS: We evaluated 36 patients with bone defects caused by trauma or orthopedic injury. Nineteen patients were male (52.8% and 17

  12. Diffuse calvarial meningioma: a case report.

    Directory of Open Access Journals (Sweden)

    Muzumdar D

    2001-04-01

    Full Text Available A rare case of a diffuse calvarial meningioma in a sixty-three year-old female is reported. The patient presented with headache, painful proptosis and chemosis of the left eye. Imaging showed that the frontoparietal calvarium on both sides and the left orbital roof were thickened. The thickened bone showed patchy rarefaction. In relationship to the thickened bone, there was an enhancing en-plaque meningioma. The tumour extended on to the superolateral aspect of the left orbit and resulted in proptosis. Excision of the left frontoparietal calvarium and the orbital tumour was performed. The management of diffuse calvarial meningioma is discussed and the relevant literature is briefly reviewed.

  13. Calvarial Suture-Derived Stem Cells and Their Contribution to Cranial Bone Repair

    Directory of Open Access Journals (Sweden)

    Daniel H. Doro

    2017-11-01

    Full Text Available In addition to the natural turnover during life, the bones in the skeleton possess the ability to self-repair in response to injury or disease-related bone loss. Based on studies of bone defect models, both processes are largely supported by resident stem cells. In the long bones, the source of skeletal stem cells has been widely investigated over the years, where the major stem cell population is thought to reside in the perivascular niche of the bone marrow. In contrast, we have very limited knowledge about the stem cells contributing to the repair of calvarial bones. In fact, until recently, the presence of specific stem cells in adult craniofacial bones was uncertain. These flat bones are mainly formed via intramembranous rather than endochondral ossification and thus contain minimal bone marrow space. It has been previously proposed that the overlying periosteum and underlying dura mater provide osteoprogenitors for calvarial bone repair. Nonetheless, recent studies have identified a major stem cell population within the suture mesenchyme with multiple differentiation abilities and intrinsic reparative potential. Here we provide an updated review of calvarial stem cells and potential mechanisms of regulation in the context of skull injury repair.

  14. Biomechanical Evaluation of Rat Skull Defects, 1, 3, and 6 Months after Implantation with Osteopromotive Substances

    DEFF Research Database (Denmark)

    Jones, Leigh Robert; Thomsen, Jesper Skovhus; Mosekilde, Lis

    2007-01-01

    Purpose: To compare the mechanical strength of surgically created and healed rat calvarial defects having been filled with three different osteopromotive substances: hydroxyapatite, intramembraneous demineralised bone matrix (DBM), and autogenous bone chips. Material: Sixty adult male Wistar rats...... were divided into three groups of 20 animals, each group representing healing times of one, three, or six months. Methods: Identical 5 mm bilateral critical size defects were trephined into the parietal bones and hydroxyapatite, DBM, or autogenous bone chips were implanted into the defects, or left...... as unfilled controls. The repaired defects were evaluated biomechanically using a modified punch out test 1, 3, or 6 months postoperatively. Results: The maximum load carried in the DBM group was significantly higher than in the bone chips, hydroxyapatite, and control groups after one month of healing...

  15. Thyroid hormone action on rat calvarial sutures.

    Science.gov (United States)

    Akita, S; Nakamura, T; Hirano, A; Fujii, T; Yamashita, S

    1994-01-01

    To clarify the effect of thyroid hormone on the calvarial sutures, the morphology, histology, and bone mineral density were analyzed in thyroid hormone-injected rats. A total of 80 female Wistar rats at the age of 10 days were divided into 2 groups; the triiodothyronine (T3)-treated rats (n = 40, T3 100 micrograms/kg body weight/day) were maintained under the same conditions as controls (n = 40, saline-vehicle only), and both were sacrificed at 50, 80, and 200 experimental days, respectively. T3-treated animals showed smaller values of lambda-asterion and pterion-bregma distances at the various periods of examination, resulting in smaller sizes in right-left direction of the skull. The sagittal suture distance in the skull specimens observed by Goldner's staining (fibrous tissue content) appeared smaller and the osseous margin widths greatly increased in the T3-treated rats. Fluorescent microscopy revealed that the tetracycline-calcein double labelings were not interrupted from the periosteal to the endosteal areas in any specimens indicating the scantiness of osteoclastic activity in the suture areas. Mineral apposition rates at the osseous edges of the suture were significantly increased in the T3-treated rats (p < 0.01 at the age of 90 days). The distance between the second labels and the distance between the first labels were significantly larger in the T3-treated rats. Bone mineral density (BMD) measurement showed that the T3 administration decreased only the calvarial BMD at the age of 210 days (p < 0.01), but did not decrease lumbar or femur BMD. This experiment demonstrated clear evidence of excess thyroid hormone action on the early narrowing of the sagittal suture in infantile hyperthyroid rats, probably due to the enhanced osteogenic activity caused by the hormone.

  16. Atypical meningioma and extensive calvarium defects in neurofibromatosis type 1

    Energy Technology Data Exchange (ETDEWEB)

    Simsek, Enver [Department of Paediatrics, Duzce Medical Faculty, Abant Izzet Baysal University, Konuralp-Duzce (Turkey); Yavuz, Cevdet [Department of Neurosurgery, Duzce Medical Faculty, Abant Izzet Baysal University, Konuralp-Duzce (Turkey); Ustundag, Nil [Department of Pathology, Abant Izzet Baysal University School of Medicine, Konuralp-Duzce (Turkey)

    2003-08-01

    A 9-year-old girl with neurofibromatosis type 1 (NF1) presented with a massive atypical meningioma and calvarial defect. Skull radiographs and cranial CT showed an extensive lytic bone lesion at the vertex. MRI demonstrated a large mass invading the calvarium and sagittal sinus. The histopathological and immunohistochemical diagnosis of the resected mass was atypical meningioma. To our knowledge, this is the first case of NF1 associated with atypical meningioma and massive calvarial defect in a child. (orig.)

  17. Atypical meningioma and extensive calvarium defects in neurofibromatosis type 1

    International Nuclear Information System (INIS)

    Simsek, Enver; Yavuz, Cevdet; Ustundag, Nil

    2003-01-01

    A 9-year-old girl with neurofibromatosis type 1 (NF1) presented with a massive atypical meningioma and calvarial defect. Skull radiographs and cranial CT showed an extensive lytic bone lesion at the vertex. MRI demonstrated a large mass invading the calvarium and sagittal sinus. The histopathological and immunohistochemical diagnosis of the resected mass was atypical meningioma. To our knowledge, this is the first case of NF1 associated with atypical meningioma and massive calvarial defect in a child. (orig.)

  18. Accelerated Calvarial Healing in Mice Lacking Toll-Like Receptor 4

    Science.gov (United States)

    Wang, Dan; Gilbert, James R.; Cray, James J.; Kubala, Adam A.; Shaw, Melissa A.; Billiar, Timothy R.; Cooper, Gregory M.

    2012-01-01

    The bone and immune systems are closely interconnected. The immediate inflammatory response after fracture is known to trigger a healing cascade which plays an important role in bone repair. Toll-like receptor 4 (TLR4) is a member of a highly conserved receptor family and is a critical activator of the innate immune response after tissue injury. TLR4 signaling has been shown to regulate the systemic inflammatory response induced by exposed bone components during long-bone fracture. Here we tested the hypothesis that TLR4 activation affects the healing of calvarial defects. A 1.8 mm diameter calvarial defect was created in wild-type (WT) and TLR4 knockout (TLR4−/−) mice. Bone healing was tested using radiographic, histologic and gene expression analyses. Radiographic and histomorphometric analyses revealed that calvarial healing was accelerated in TLR4−/− mice. More bone was observed in TLR4−/− mice compared to WT mice at postoperative days 7 and 14, although comparable healing was achieved in both groups by day 21. Bone remodeling was detected in both groups on postoperative day 28. In TLR4−/− mice compared to WT mice, gene expression analysis revealed that higher expression levels of IL-1β, IL-6, TNF-α,TGF-β1, TGF-β3, PDGF and RANKL and lower expression level of RANK were detected at earlier time points (≤ postoperative 4 days); while higher expression levels of IL-1β and lower expression levels of VEGF, RANK, RANKL and OPG were detected at late time points (> postoperative 4 days). This study provides evidence of accelerated bone healing in TLR4−/− mice with earlier and higher expression of inflammatory cytokines and with increased osteoclastic activity. Further work is required to determine if this is due to inflammation driven by TLR4 activation. PMID:23071670

  19. Accelerated calvarial healing in mice lacking Toll-like receptor 4.

    Directory of Open Access Journals (Sweden)

    Dan Wang

    Full Text Available The bone and immune systems are closely interconnected. The immediate inflammatory response after fracture is known to trigger a healing cascade which plays an important role in bone repair. Toll-like receptor 4 (TLR4 is a member of a highly conserved receptor family and is a critical activator of the innate immune response after tissue injury. TLR4 signaling has been shown to regulate the systemic inflammatory response induced by exposed bone components during long-bone fracture. Here we tested the hypothesis that TLR4 activation affects the healing of calvarial defects. A 1.8 mm diameter calvarial defect was created in wild-type (WT and TLR4 knockout (TLR4(-/- mice. Bone healing was tested using radiographic, histologic and gene expression analyses. Radiographic and histomorphometric analyses revealed that calvarial healing was accelerated in TLR4(-/- mice. More bone was observed in TLR4(-/- mice compared to WT mice at postoperative days 7 and 14, although comparable healing was achieved in both groups by day 21. Bone remodeling was detected in both groups on postoperative day 28. In TLR4(-/- mice compared to WT mice, gene expression analysis revealed that higher expression levels of IL-1β, IL-6, TNF-α,TGF-β1, TGF-β3, PDGF and RANKL and lower expression level of RANK were detected at earlier time points (≤ postoperative 4 days; while higher expression levels of IL-1β and lower expression levels of VEGF, RANK, RANKL and OPG were detected at late time points (> postoperative 4 days. This study provides evidence of accelerated bone healing in TLR4(-/- mice with earlier and higher expression of inflammatory cytokines and with increased osteoclastic activity. Further work is required to determine if this is due to inflammation driven by TLR4 activation.

  20. Reconstruction of saddle nose deformity with calvarial bone graft

    International Nuclear Information System (INIS)

    Ghiasi, S.

    2013-01-01

    Objective: To evaluate the efficacy of calvarial bone in the reconstruction of saddle nose deformity. Methods: The cross-sectional study was conducted at the Plastic Surgery Unit of Imam Reza Hospital, Tabriz University of Medical Sciences, Iran, from July 2004 to October 2009. It comprised 19 patients who underwent saddle nose deformity reconstruction with calvarial bone graft. All patients were operated upon under general anaesthesia. They were followed up periodically. Results: The patients followed up for 25 to 61 months for an average period of 39.2+-4.3 months. In 14 (74%) patients the result of the surgical intervention was excellent, while in 5 (26%) it was acceptable. All patients were satisfied and there was not displacement, absorption, distortion or infection of the graft. Conclusion: Calvarial bone graft is a viable option for the reconstruction of saddle nose deformity, especially in severe cases. (author)

  1. Donor site complications in bone grafting: comparison of iliac crest, calvarial, and mandibular ramus bone.

    Science.gov (United States)

    Scheerlinck, Laura M E; Muradin, Marvick S M; van der Bilt, Andries; Meijer, Gert J; Koole, Ronald; Van Cann, Ellen M

    2013-01-01

    To compare the donor site complication rate and length of hospital stay following the harvest of bone from the iliac crest, calvarium, or mandibular ramus. Ninety-nine consecutively treated patients were included in this retrospective observational single-center study. Iliac crest bone was harvested in 55 patients, calvarial bone in 26 patients, and mandibular ramus bone in 18 patients. Harvesting of mandibular ramus bone was associated with the lowest percentages of major complications (5.6%), minor complications (22.2%), and total complications (27.8%). Harvesting of iliac crest bone was related to the highest percentages of minor complications (56.4%) and total complications (63.6%), whereas harvesting of calvarial bone induced the highest percentage of major complications (19.2%). The length of the hospital stay was significantly influenced by the choice of donor site (P = .003) and age (P = .009); young patients with the mandibular ramus as the donor site had the shortest hospital stay. Harvesting of mandibular ramus bone was associated with the lowest percentage of complications and the shortest hospital stay. When the amount of bone to be obtained is deemed sufficient, mandibular ramus bone should be the first choice for the reconstruction of maxillofacial defects.

  2. Bone marker gene expression in calvarial bones: different bone microenvironments.

    Science.gov (United States)

    Al-Amer, Osama

    2017-12-01

    In calvarial mice, mesenchymal stem cells (MSCs) differentiate into osteoprogenitor cells and then differentiate into osteoblasts that differentiate into osteocytes, which become embedded within the bone matrix. In this case, the cells participating in bone formation include MSCs, osteoprogenitor cells, osteoblasts and osteocytes. The calvariae of C57BL/KaLwRijHsD mice consist of the following five bones: two frontal bones, two parietal bones and one interparietal bone. This study aimed to analyse some bone marker genes and bone related genes to determine whether these calvarial bones have different bone microenvironments. C57BL/KaLwRijHsD calvariae were carefully excised from five male mice that were 4-6 weeks of age. Frontal, parietal, and interparietal bones were dissected to determine the bone microenvironment in calvariae. Haematoxylin and eosin staining was used to determine the morphology of different calvarial bones under microscopy. TaqMan was used to analyse the relative expression of Runx2, OC, OSX, RANK, RANKL, OPG, N-cadherin, E-cadherin, FGF2 and FGFR1 genes in different parts of the calvariae. Histological analysis demonstrated different bone marrow (BM) areas between the different parts of the calvariae. The data show that parietal bones have the smallest BM area compared to frontal and interparietal bones. TaqMan data show a significant increase in the expression level of Runx2, OC, OSX, RANKL, OPG, FGF2 and FGFR1 genes in the parietal bones compared with the frontal and interparietal bones of calvariae. This study provides evidence that different calvarial bones, frontal, parietal and interparietal, contain different bone microenvironments.

  3. Intraluminal filling defects of the bile ducts: differentiation of stones from tumors-the value of magnetic resonance cholangiography in conjunction with a 3D spoiled gradient echo gadolinium enhanced dynamic sequence

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Jin; Kim, Suk; Kim, Chang Won [Busan National University Hospital, Busan (Korea, Republic of)] (and others)

    2006-05-15

    We wanted to determinate the value of a dynamic volumetric interpolated breath-hold examination (VIBE) as a supplement to MR cholangiography for differentiating biliary stones from tumors when patient are suspected of having intraluminal filling defects on direct cholangiography. A retrospective analysis was performed for 49 patients who underwent MRI among all the patients who showed intraluminal filling defects on direct cholangiography for evaluating the cause of their jaundice from June 2002 to June 2003. After dividing these patients into two groups; i.e., the group with stones and the group wth tumors, we analyzed and compared each MR patterns of 1) signal intensity, 2) shape, and 3) enhancement. High signal intensity on T1-weighted images ({rho} < 0.001, X{sup 2} test), dark signal intensity on T2-weighted images ({rho} < 0.01, Fisher' s exact test) or smooth contour of intraluminal filling defects ({rho} < 0.001, X{sup 2} test) could be significantly suggestive findings of stone rather than a tumor mass. Dynamic VIBE is the most specific sequence for differentiating non-enhancing stone from an enhancing mass ({rho} < 0.001, Fisher' s exact test). We showed that MR cholangiography, when added to the dynamic VIBE sequences, could be an important imaging technique for patients who are suspected of having intraluminal filling defects on direct cholangiography to differentiate stones from tumors. Especially, the addition of dynamic VIBE images can provide the increased level of confidence in the diagnosis.

  4. Calvarial periosteal graft for second-stage cleft palate surgery: a preliminary report.

    Science.gov (United States)

    Neiva, Cecilia; Dakpe, Stephanie; Gbaguidi, Cica; Testelin, Sylvie; Devauchelle, Bernard

    2014-07-01

    The objectives of cleft palate surgery are to achieve optimal outcomes regarding speech development, hearing, maxillary arch development and facial skull growth. Early two-stage cleft palate repair has been the most recent protocol of choice to achieve good maxillary arch growth without compromising speech development. Hard palate closure occurs within one year of soft palate surgery. However, in some cases the residual hard palate cleft width is larger than 15 mm at the age of two. As previously reported, integrated speech development starts around that age and it is a challenge since we know that early mobilization of the mucoperiosteum interferes with normal facial growth on the long-term. In children with large residual hard palate clefts at the age 2, we report the use of calvarial periosteal grafts to close the cleft. With a retrospective 6-year study (2006-2012) we first analyzed the outcomes regarding impermeability of hard palate closure on 45 patients who at the age of two presented a residual cleft of the hard palate larger than 15 mm and benefited from a periosteal graft. We then studied the maxillary growth in these children. In order to compare long-term results, we included 14 patients (age range: 8-20) treated between 1994 & 2006. Two analyses were conducted, the first one on dental casts from birth to the age of 6 and the other one based on lateral cephalograms following Delaire's principles and TRIDIM software. After the systematic cephalometric analysis of 14 patients, we found no evidence of retrognathia or Class 3 dental malocclusion. In the population of 45 children who benefited from calvarial periosteal grafts the rate of palate fistula was 17% vs. 10% in the overall series. Despite major advances in understanding cleft defects, the issues of timing and choice of the surgical procedure remain widely debated. In second-stage surgery for hard palate closure, using a calvarial periosteal graft could be the solution for large residual clefts

  5. Religious Landscape and Ecological Ethics: Pilgrimage to the Lithuanian Calvaries

    Directory of Open Access Journals (Sweden)

    Darius Liutikas

    2015-07-01

    Full Text Available This article deals with the ecology of pilgrimage at the Calvaries – Ways of the Cross – in Lithuania. Personal obligations to nature and respect of sacred place intermingle with devotional practices and certain rituals. Large scale arrivals at the Calvaries only occurs at certain times of year, mostly during the Indulgence Feasts. Devotional practices such as meditation on the suffering of Christ, prayers and hymns, playing musical instruments, washing one’s face at the Cedron spring are quite common during the Way. Research shows that walking the Way of the Cross doesn’t cause negative environmental, cultural and social impacts. Moreover, pilgrimage could be beneficial to local communities - providing opportunities to sell handcraft products, to meet relatives and friends. Visiting Calvaries is a religious act restrained by time: usually it takes about 3-4 hours to undertake the Stations of the Cross, about one hour to celebrate Holy Mass, and up to one hour at the market place buying religious memorabilia and other souvenirs.

  6. Fronto-Orbital Advancement and Total Calvarial Remodelling for Craniosynostosis

    International Nuclear Information System (INIS)

    Haq, E. U.; Aman, S.; Tammimy, M. S.; Ahmad, R. S.

    2014-01-01

    Objective: To describe the results of fronto-orbital advancement and remodelling for craniosynostosis in children. Study Design: Case series. Place and Duration of Study: Department of Plastic Surgery, Combined Military Hospital, Rawalpindi, from June 2009 to June 2012. Methodology: All the patients with cranial suture synostosis operated were included in the study. Those patients who were lost to follow-up were excluded. Variables considered were age, gender, type of synostosis, intracranial pressure, and history of previous surgeries for the same problem. Outcome measures were studied in terms of improvement of skull measurements (anteroposterior and bicoronal), duration of surgery, hospital stay, blood transfusions, complications and parents satisfaction. Results: A total of 36 patients were included in the study. Male to female ratio was 3:1. The age ranged from 5 to 54 months. Thirty two patients presented with non-syndromic and four with syndromic craniosynostosis. Fronto orbital advancement and total calvarial remodelling was done in 26 and 10 patients respectively. There was improvement in the skull measurements and the parents were satisfied in all cases with the skull shape. Complications occurred in 11.1% including chest and wound infection and one death. Conclusion: Fronto-orbital advancement and remodelling is an effective procedure for the correction of craniosynostosis, however, individual cases may require other procedures like total calvarial remodelling. (author)

  7. Regenerative capacity of augmented bone in rat calvarial guided bone augmentation model.

    Science.gov (United States)

    Kubota, Tatsuya; Hasuike, Akira; Ozawa, Yasumasa; Yamamoto, Takanobu; Tsunori, Katsuyoshi; Yamada, Yutaka; Sato, Shuichi

    2017-04-01

    Guided bone regeneration (GBR) is the most widely used technique to regenerate and augment bones. Even though augmented bones (ABs) have been examined histologically in many studies, few studies have been conducted to examine the biological potential of these bones and the healing dynamics following their use. Moreover, whether the bone obtained from the GBR procedure possesses the same functions as the existing autogenous bone is uncertain. In particular, little attention has been paid to the regenerative ability of GBR bone. Therefore, the present study histologically evaluated the regenerative capacity of AB in the occlusive space of a rat guided bone augmentation (GBA) model. The calvaria of 30 rats were exposed, and plastic caps were placed on the right of the calvaria in 10 of the 30 rats. After a 12-week healing phase, critical-sized calvarial bone defects (diameter: 5.0 mm) were trephined into the dorsal parietal bone on the left of the calvaria. Bone particles were harvested from the AB or the cortical bone (CB) using a bone scraper and transplanted into the critical defects. The newly generated bone at the defects' edge was evaluated using micro-computed tomography (micro-CT) and histological sections. In the micro-CT analysis, the radiopacity in both the augmented and the CB groups remained high throughout the observational period. In the histological analysis, the closure rate of the CB was significantly higher than in the AB group. The numbers of cells positive for runt-related transcription factor 2 (Runx2) and tartrate-resistant acid phosphatase (TRAP) in the AB group were larger than in the CB group. The regenerative capacity of AB in the occlusive space of the rat GBA model was confirmed. Within the limitations of this study, the regenerative ability of the AB particulate transplant was inferior to that of the CB particulate transplant.

  8. Congenital giant plexiform neurofibroma with occipital calvarial dysplasia in association with meningoencephalocele in neurofibromatosis Type 1 and segmental neurofibromatosis: report of 2 cases.

    Science.gov (United States)

    Dadlani, Ravi; Sadanand, Venkatraman; Ghosal, Nandita; Hegde, Alangar S

    2013-11-01

    Giant plexiform neurofibroma (GPNF) of the scalp is an extremely rare lesion reported in association with neurofibromatosis. Occipital location of GPNF is even more infrequent, especially in association with occipital dysplasia (OD). The authors report 2 pediatric cases of GPNF associated with OD. The first case had an associated meningoencephalocele, and the second had large vascular channels within the lesion and the dominant ipsilateral transverse sinus lying in the center of the calvarial defect. The authors present these 2 unusual cases with a review of literature and discuss the radiological findings, theories of etiopathogenesis of the OD, and management dilemmas.

  9. Computed tomographic analysis of calvarial hyperostosis in captive lions.

    Science.gov (United States)

    Gross-Tsubery, Ruth; Chai, Orit; Shilo, Yael; Miara, Limor; Horowitz, Igal H; Shmueli, Ayelet; Aizenberg, Itzhak; Hoffman, Chen; Reifen, Ram; Shamir, Merav H

    2010-01-01

    Osseous malformations in the skull and cervical vertebrae of lions in captivity are believed to be caused by hypovitaminosis A. These often lead to severe neurologic abnormalities and may result in death. We describe the characterization of these abnormalities based on computed tomography (CT). CT images of two affected and three healthy lions were compared with define the normal anatomy of the skull and cervical vertebrae and provide information regarding the aforementioned osseous malformations. Because bone structure is influenced by various factors other than the aforementioned disease, all values were divided by the skull width that was not affected. The calculated ratios were compared and the most pronounced abnormalities in the affected lions were, narrowing of the foramen magnum, thickening of the tentorium osseus cerebelli and thickening of the dorsal arch of the atlas. CT is useful for detection of the calvarial abnormalities in lions and may be useful in further defining this syndrome.

  10. Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Lee-Chuan C.; Ford, Jeffery J. [Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX (United States); Lee, John C. [Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX (United States); The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, TX (United States); Adamo, Martin L., E-mail: adamo@biochem.uthscsa.edu [Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX (United States); The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, TX (United States)

    2014-07-18

    Highlights: • Palmitate inhibits osteoblast differentiation. • Fatty acid synthase. • PPARγ. • Acetyl Co-A carboxylase inhibitor TOFA. • Fetal rat calvarial cell culture. - Abstract: Aging is associated with the accumulation of ectopic lipid resulting in the inhibition of normal organ function, a phenomenon known as lipotoxicity. Within the bone marrow microenvironment, elevation in fatty acid levels may produce an increase in osteoclast activity and a decrease in osteoblast number and function, thus contributing to age-related osteoporosis. However, little is known about lipotoxic mechanisms in intramembraneous bone. Previously we reported that the long chain saturated fatty acid palmitate inhibited the expression of the osteogenic markers RUNX2 and osteocalcin in fetal rat calvarial cell (FRC) cultures. Moreover, the acetyl CoA carboxylase inhibitor TOFA blocked the inhibitory effect of palmitate on expression of these two markers. In the current study we have extended these observations to show that palmitate inhibits spontaneous mineralized bone formation in FRC cultures in association with reduced mRNA expression of RUNX2, alkaline phosphatase, osteocalcin, and bone sialoprotein and reduced alkaline phosphatase activity. The effects of palmitate on osteogenic marker expression were inhibited by TOFA. Palmitate also inhibited the mRNA expression of fatty acid synthase and PPARγ in FRC cultures, and as with osteogenic markers, this effect was inhibited by TOFA. Palmitate had no effect on FRC cell proliferation or apoptosis, but inhibited BMP-7-induced alkaline phosphatase activity. We conclude that palmitate accumulation may lead to lipotoxic effects on osteoblast differentiation and mineralization and that increases in fatty acid oxidation may help to prevent these lipotoxic effects.

  11. Death due to fracture of thin calvarial bones after a fall: A forensic approach

    Directory of Open Access Journals (Sweden)

    Georgios Sioutas

    2017-06-01

    Full Text Available A 45-year-old male was autopsied. He had fallen backwards from a two-stairs height to the ground and passed away. A skull fracture was detected in the left occipital area, extending up to the left side of the skull base. The patient's death occurred due to the very low thickness of the calvarial bones, which led to the aforementioned fracture, and in turn resulted in subarachnoid hemorrhage and death. The cortical thickness was measured and compared with average values at standardized points. Uniform bone thinning was confirmed rather than localized. Calvarial thinning may result from various conditions. In the present case study, however, the exact mechanism which led to the low thickness of the calvarial bones of the patient is undetermined. Death due to the susceptible structure and fracture of calvarial bones has rarely been reported throughout relevant literature.

  12. Reprogramming of Mouse Calvarial Osteoblasts into Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Yinxiang Wang

    2018-01-01

    Full Text Available Previous studies have demonstrated the ability of reprogramming endochondral bone into induced pluripotent stem (iPS cells, but whether similar phenomenon occurs in intramembranous bone remains to be determined. Here we adopted fluorescence-activated cell sorting-based strategy to isolate homogenous population of intramembranous calvarial osteoblasts from newborn transgenic mice carrying both Osx1-GFP::Cre and Oct4-EGFP transgenes. Following retroviral transduction of Yamanaka factors (Oct4, Sox2, Klf4, and c-Myc, enriched population of osteoblasts underwent silencing of Osx1-GFP::Cre expression at early stage of reprogramming followed by late activation of Oct4-EGFP expression in the resulting iPS cells. These osteoblast-derived iPS cells exhibited gene expression profiles akin to embryonic stem cells and were pluripotent as demonstrated by their ability to form teratomas comprising tissues from all germ layers and also contribute to tail tissue in chimera embryos. These data demonstrate that iPS cells can be generated from intramembranous osteoblasts.

  13. Influence of the Neo-Os® bone substitute powder on calvarial bone healing with and without membrane

    Directory of Open Access Journals (Sweden)

    Namjoy Nik Sh.

    2002-08-01

    Full Text Available Nowadays, different materials have been used for regeneration of interosseous defects and Neo-Os is one of them. The objective of this study was to evaluate histologically the influence of Neo-Os® particles on bone regeneration using rabbit caivarias defects with and without protection of Gore-Tex® barrier membrane. A cutaneous- periosteal incision and flap was made on the forehead of 32 rabbits exposing the top o"" the skull. A standardized trans-osseous skull defect (8 mm diameter was made in each of the parietal bone with rotating round bur. In half of the rabbits, one defect was filled with the Neo-Os® particles without any type of the barrier membrane. The other defect was left empty. In the other half of the rabbits, one defect was filled with Neo-Os® and two flat expanded polytetrafiuoroethyiene (Gore-tex® membranes. For the other defect, only the Gore-tex membrane protected the defect. After 8 and 16 weeks, the specimens were processed using standard, decalcified, hard tissue histology techniques. Rabbit caivarias defects treated with Neo-Os® particles and polytetrafiuoroethyiene (Gore-tex® membrane, healed by in growth of woven bone from the defect margins and by formation of bony islands within the defect area. Finally, the defects were treated with woven and lamellar bone.

  14. Filled Craters

    Science.gov (United States)

    2006-01-01

    11 May 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows adjacent impact craters located north-northwest of the Acheron Fossae region of Mars. The two craters are of similar size and formed by meteor impacts. However, one is much more filled than the other, indicating that it is older. The surface of the material in the older, partially-filled crater has a texture similar to the crater's surroundings. The southern (bottom) crater is bowl-shaped and is also partially-filled, however, the filling material seems to be limited to the southern half of the crater. Location near: 44.6oN, 128.4oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  15. Solitary giant neurofibroma of the scalp with calvarial defect in a child

    African Journals Online (AJOL)

    Neurofibroma of the scalp are mostly multiple as part of neurofibromatosis or other phakomatosis. De novo solitary types are less common and rarely erode the skull, unlike the intracranial counterpart. Skull erosion has been reported in adults with longstanding plexiform neurofibromas. We report a giant neurofibroma on ...

  16. Solitary Giant Neurofibroma of the Scalp with Calvarial Defect in a ...

    African Journals Online (AJOL)

    2010-06-29

    Jun 29, 2010 ... no headache, vomiting, visual impairment or seizures. Examination revealed a young boy who was not pale, not febrile, had no lymphadenopathy, and there ... types are less common and rarely erode the skull, unlike the intracranial counterpart. Skull erosion has been reported in adults with longstanding ...

  17. Partial thickness autologus calvarial bone orbitocranioplasty for a sphenorbital encephalocele presenting as pulsatile exophthalmos

    OpenAIRE

    Trivedi, Adarsh; Garg, Amrish Kumar; Hiran, Subodh

    2015-01-01

    Basal encephalocele accounts only 1.5% of all encephaloceles. But Sphenorbital encephalocele is the rarest cause of herniation of brain into orbit leading to pulsatile exphothalmos. Authors presenting a case of sphenorbital encephalocele in a 16 yrs old girl successsfully managed by orbitcranioplasty by partilal thickness autologus calvarial bone graft.

  18. Death due to fracture of thin calvarial bones after a fall: A forensic approach.

    Science.gov (United States)

    Sioutas, Georgios; Karakasi, Maria-Valeria; Kapetanakis, Stylianos; Pavlidis, Pavlos

    2017-06-01

    A 45-year-old male was autopsied. He had fallen backwards from a two-stairs height to the ground and passed away. A skull fracture was detected in the left occipital area, extending up to the left side of the skull base. The patient's death occurred due to the very low thickness of the calvarial bones, which led to the aforementioned fracture, and in turn resulted in subarachnoid hemorrhage and death. The cortical thickness was measured and compared with average values at standardized points. Uniform bone thinning was confirmed rather than localized. Calvarial thinning may result from various conditions. In the present case study, however, the exact mechanism which led to the low thickness of the calvarial bones of the patient is undetermined. Death due to the susceptible structure and fracture of calvarial bones has rarely been reported throughout relevant literature. Copyright © 2017 Daping Hospital and the Research Institute of Surgery of the Third Military Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  19. β-catenin/cyclin D1 mediated development of suture mesenchyme in calvarial morphogenesis

    Directory of Open Access Journals (Sweden)

    Yu Hsiao-Man

    2010-11-01

    Full Text Available Abstract Background Mouse genetic study has demonstrated that Axin2 is essential for calvarial development and disease. Haploid deficiency of β-catenin alleviates the calvarial phenotype caused by Axin2 deficiency. This loss-of-function study provides evidence for the requirement of β-catenin in exerting the downstream effects of Axin2. Results Here we utilize a gain-of-function analysis to further assess the role of β-catenin. A transgenic expression system permitting conditional activation of β-catenin in a spatiotemporal specific manner has been developed. Aberrant stimulation of β-catenin leads to increases in expansion of skeletogenic precursors and the enhancement of bone ossification reminiscent to the loss of Axin2. The constitutively active signal promotes specification of osteoprogenitors, but prevents their maturation into terminally differentiated osteoblasts, along the osteoblast lineage. However, the prevention does not interfere with bone synthesis, suggesting that mineralization occurs without the presence of mature osteoblasts. β-catenin signaling apparently plays a key role in suture development through modulation of calvarial morphogenetic signaling pathways. Furthermore, genetic inactivation of the β-catenin transcriptional target, cyclin D1, impairs expansion of the skeletogenic precursors contributing to deficiencies in calvarial ossification. There is a specific requirement for cyclin D1 in populating osteoprogenitor cell types at various developmental stages. Conclusion These findings advance our knowledge base of Wnt signaling in calvarial morphogenesis, suggesting a key regulatory pathway of Axin2/β-catenin/cyclin D1 in development of the suture mesenchyme.

  20. Multidisciplinary approach for reconstruction of cranial defect with polymethyl methacrylate resin reinforced with titanium mesh.

    Science.gov (United States)

    Sane, Vikrant Dilip; Kadam, Pankaj; Jadhav, Aniket; Saddiwal, Rashmi; Merchant, Yash

    2016-01-01

    Cranial defects occur most commonly as a sequelae to trauma, the incidence being as high as 70%. The successful management of a case of trauma in an emergency situation requires quick evacuation of the hematoma, repair of the dura, and the scalp but not necessarily the integrity of the calvarial segment as an immediate measure. So the reconstruction of the calvarial defect in these cases is mostly carried out as a secondary procedure. Various materials are used for reconstruction of cranial defects, polymethyl methacrylate (PMMA) resin being one of them. In this article, we report a case which was successfully treated by PMMA resin in combination with a titanium mesh for reconstruction of the cranial defect as a secondary procedure.

  1. DEFECTS SIMULATION OF ROLLING STRIP

    OpenAIRE

    Rudolf Mišičko; Tibor Kvačkaj; Martin Vlado; Lucia Gulová; Miloslav Lupták; Jana Bidulská

    2009-01-01

    The defects in the continuous casting slabs can be developed or kept down in principle by rolling technology, especially depend to sort, size and distribution of primary defects, as well as used of rolling parameters. Scope of the article is on observation behavior artificial surface and undersurface defects (scores) without filler (surface defects) and filling by oxides and casting powder (subsurface defects). First phase of hot rolling process have been done by software simulation DEFORM 3D...

  2. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  3. Evaluation of bone repair of critical size defects treated with simvastatin-loaded poly(lactic-co-glycolic acid) microspheres in rat calvaria.

    Science.gov (United States)

    Ferreira, Lorraine B; Bradaschia-Correa, Vivian; Moreira, Mariana M; Marques, Natasha D M; Arana-Chavez, Victor E

    2015-02-01

    Statins are hypolipemiant drugs with osteoinductive effect. We evaluated the potential of simvastatin loaded into poly(lactic-co-glycolic acid) (PLGA) microspheres to heal critical size defects in rat calvaria. PLGA scaffolds (50:50 ratio) were synthesized as pure membranes or as microspheres loaded with 2.5% simvastatin. Critical size defects (5-mm diameter) were created in the parietal bone of 3-month-old male Wistar rats; they were either left filled with blood clot (C group), covered with a PLGA membrane (M group) or with PLGA microspheres loaded with simvastatin (MSI group) or not (MM group), and then covered with the PLGA membrane. The defects were evaluated after 30 or 60 days by light and electron microscopy, immunohistochemistry for osteopontin (OPN), bone sialoprotein (BSP) and osteoadherin (OSAD), and immunocytochemistry for OPN. Scanning electron microscopy showed that the calvarial defects treated with MSI were almost completely healed after 60 days, while groups M and C presented less bone formation, whereas the bone matrix formed into the defects of MSI group was more organized and mature. The immunolabeling for OPN and BSP on the matrix in groups C and M showed typical areas of primary bone unlike the MSI that presented weak labeling at the formed area. In the MSI group, there was an intense immunostaining for OSAD in osteoid, as well as in osteocyte cytoplasm. The immunocytochemistry showed intense labeling for OPN with homogeneous distribution in the interfibrillar spaces in all groups after 30 days and after 60 days; however, while C and M groups exhibited similar aspect, the MSI specimens showed weak labeling. The ultrastructural evaluation showed the interaction between the biomaterial and the surrounding tissue where some cells established intimate contact with microspheres. The repair of critical size bone defects was accelerated and enhanced by the implantation of simvastatin-loaded PLGA microspheres. © The Author(s) 2014 Reprints and

  4. Castor oil polyurethane containing silica nanoparticles as filling material of bone defect in rats Poliuretana de mamona contendo nanopartículas de sílica como material de preenchimento de defeito ósseo em ratos

    Directory of Open Access Journals (Sweden)

    Renato Silva Nacer

    2012-01-01

    Full Text Available PURPOSE: To evaluate the biologic behavior of the castor polymer containing silica nanoparticles as a bone substitute in diafisary defect. METHODS: Twenty seven male rattus norvegicus albinus wistar lineage were submitted to bone defect filled with castor oil polymer. Three experimental groups had been formed with nine animals each: (1 castor oil polymer containing only calcium carbonate; (2 castor oil polymer with calcium carbonate and doped with 5% of silica nanoparticles; (3 castor polymer with calcium carbonate doped with 10% of silica nanoparticles; 3 animals of each group were submitted to euthanasia 15, 30 and 60 days after experimental procedure, and their femurs were removed to histological evaluation. RESULTS: there was bone growth in all the studied groups, with a greater tendency of growth in the group 1. After 30 days all the groups presented similar results. After 60 days a greater amount of fibroblasts, osteoblasts, osteocytes and osteoclasts in group 3 was observed, with integrated activity of 3 kinds of cells involved in the bone activation-reabsorption-formation. CONCLUSIONS: The castor polymer associated to the silica nanoparticles is biocompatible and allows osteoconduction. The presence of osteoprogenitors cells suggests silica osteoinduction capacity.OBJETIVO: Avaliar o comportamento biológico do polímero de mamona contendo nanopartículas de sílica como substituto ósseo. MÉTODOS: Vinte e sete rattus norvergicus albinus, Wistar foram submetidos a defeito ósseo preenchido com polímero de mamona. Foram formados três grupos experimentais, com nove ratos cada: (1 Polímero com carbonato de cálcio; (2 Polímero com carbonato de cálcio dopado com 5% de nanopartículas de sílica; (3 Polímero com carbonato de cálcio dopado com 10% de nanopartículas de sílica; três animais de cada grupo foram submetidos à eutanásia 15, 30 e 60 dias após o procedimento experimental e os fêmures removidos e submetidos à avalia

  5. Unravelling the molecular control of calvarial suture fusion in children with craniosynostosis

    Directory of Open Access Journals (Sweden)

    Morris C Phillip

    2007-12-01

    Full Text Available Abstract Background Craniosynostosis, the premature fusion of calvarial sutures, is a common craniofacial abnormality. Causative mutations in more than 10 genes have been identified, involving fibroblast growth factor, transforming growth factor beta, and Eph/ephrin signalling pathways. Mutations affect each human calvarial suture (coronal, sagittal, metopic, and lambdoid differently, suggesting different gene expression patterns exist in each human suture. To better understand the molecular control of human suture morphogenesis we used microarray analysis to identify genes differentially expressed during suture fusion in children with craniosynostosis. Expression differences were also analysed between each unfused suture type, between sutures from syndromic and non-syndromic craniosynostosis patients, and between unfused sutures from individuals with and without craniosynostosis. Results We identified genes with increased expression in unfused sutures compared to fusing/fused sutures that may be pivotal to the maintenance of suture patency or in controlling early osteoblast differentiation (i.e. RBP4, GPC3, C1QTNF3, IL11RA, PTN, POSTN. In addition, we have identified genes with increased expression in fusing/fused suture tissue that we suggest could have a role in premature suture fusion (i.e. WIF1, ANXA3, CYFIP2. Proteins of two of these genes, glypican 3 and retinol binding protein 4, were investigated by immunohistochemistry and localised to the suture mesenchyme and osteogenic fronts of developing human calvaria, respectively, suggesting novel roles for these proteins in the maintenance of suture patency or in controlling early osteoblast differentiation. We show that there is limited difference in whole genome expression between sutures isolated from patients with syndromic and non-syndromic craniosynostosis and confirmed this by quantitative RT-PCR. Furthermore, distinct expression profiles for each unfused suture type were noted, with

  6. Jaw cysts - filling or no filling after enucleation? A review.

    Science.gov (United States)

    Ettl, Tobias; Gosau, Martin; Sader, Robert; Reichert, Torsten E

    2012-09-01

    Jaw cysts are common lesions in the oral and maxillofacial region. Enucleation of the lesions and primary closure of the defects, the so-called "cystectomy", has evolved as the treatment of choice. In order to reduce infections and to accelerate bone regeneration, different types of bone grafts are increasingly investigated for defect filling. The present review reflects the most recent studies using autogenous, allogenic, xenogenic and alloplastic bone grafts and compares the results to current investigations about conservative cyst enucleation without using any filling materials. Relevant studies with significant patient sample sizes were electronically searched in PubMed and Medline. Simple cyst enucleation and blood clot healing show low complication rates and sufficient bone regeneration even in large defects. Prospective randomized trials comparing the additional use of filling materials to the "cystectomy" are rare. Currently available data do not indicate the superiority of additional bone grafts. Enucleation of jaw cysts and primary closure without bone substitutes remains "state of the art" in most cases. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  7. Surface temperature distributions in carbon dioxide, argon, and KTP (Nd:YAG) laser ablated otic capsule and calvarial bone

    NARCIS (Netherlands)

    Wong, B. J.; Neev, J.; van Gemert, M. J.

    1997-01-01

    The spatial and temporal surface temperature distribution was measured after laser irradiation in fresh porcine otic capsule and calvarial bone tissue using an HgCdTe (mercury-cadmium-tellurium) infrared camera. Carbon dioxide (CO2) (lambda = 10.6 mm), argon (lambda = 514 nm), and

  8. About Dental Amalgam Fillings

    Science.gov (United States)

    ... Medical Procedures Dental Devices Dental Amalgam About Dental Amalgam Fillings Share Tweet Linkedin Pin it More sharing ... I have my fillings removed? What is dental amalgam? Dental amalgam is a dental filling material used ...

  9. Calvarial Tuberculosis in a Preschool-Aged Child: An uncommon entity

    Directory of Open Access Journals (Sweden)

    Avradip Santra

    2018-01-01

    Full Text Available Calvarial tuberculosis is a rare manifestation of tuberculosis, especially in children under five years of age. We report a two-and-a-half-year-old male child who presented to the Nilratan Sircar Medical College, Kolkata, India, in 2015 with frontoparietal fluctuant swelling of three months’ duration. He had also had chronic sinus discharge from the left lower eyelid over the previous six months. Computed tomography of the head revealed a frontal swelling along with erosion of both the outer and inner plates of the left frontal bone. Fine needle aspiration of the pus indicated the presence of acid-fast bacilli. Unfortunately, no primary focus of tuberculosis could be established. The patient improved after one year of antitubercular therapy without requiring any surgical intervention and with no sign of subsequent disease recurrence.

  10. Calvarial-orbital Metastasis of Prostate Carcinoma which was Diagnosed with Sixth Cranial Nerve Palsy.

    Science.gov (United States)

    Özbek, Zühtü; Özkara, Emre; Arik, Deniz; Ant, Metin Atasoy

    2017-01-01

    Sixth nerve palsy is frequently due to infectious orbital lesions, trauma, elevated intracranial pressure, brainstem lesions, and vasculopathies. Here, we describe a rare cause of sixth cranial nerve (CN) palsy secondary to calvarial and orbital metastasis of prostate carcinoma. The diagnosis of the prostate carcinoma with sixth CN palsy is a very rare condition. A 66-year-old male patient presented with complaints of blurred vision, double vision, and inability to move outward in the right eye for 3 weeks. Magnetic resonance imaging revealed a right orbitocalvarial mass and the mass surgically removed completely. Pathologic findings were compatible with prostate adenocarcinoma metastasis. After surgical removal, significant improvement in sixth CN palsy was observed.

  11. Effect of calvarial burring on resorption of onlay cranial bone graft.

    Science.gov (United States)

    Hassanein, Aladdin H; Clune, James E; Mulliken, John B; Arany, Praveen R; Rogers, Gary F; Kulungowski, Ann M; Greene, Arin K

    2012-09-01

    Variable resorption occurs whenever calvarial bone graft is used for onlay cranioplasty. The recipient ectocortex may be burred to expose vessels and osteocytes to maximize healing. The purpose of this study was to determine whether abrading the recipient site improves the volume of onlay graft. The parietal bones of 17 rabbits were sectioned into split-thickness and full-thickness grafts. The right frontal cortex was abraded with a bur to punctate bleeding. Pairs of split-thickness (n = 48) or full-thickness (n = 20) grafts were onlayed to the burred right frontal bone and to the nonburred left frontal bone. Micro-computed tomography was used to determine graft volume immediately postoperatively and 16 weeks later. Histology, including tartrate-resistant acid phosphatase staining, was performed to quantify vascular channels and osteoclasts per high-power field 10 days postoperatively. Split-thickness graft volume decreased 58.0% when placed on the burred calvarial site, compared with grafts on the nonburred cortex (28.4%) (P = 0.01). Full-thickness grafts showed a similar trend: greater resorption (39.1%) when onlayed onto abraded calvaria compared with nonburred ectocortex (26.0%) (P = 0.11). Split-thickness graft orientation (cortical vs cancellous side in contact with the recipient site) did not affect resorption (P = 0.67). Onlay grafts placed on the burred recipient site had more vascular channels (11.8) and osteoclasts (5.7), compared with grafts over nonabraded cortex (3.4 and 4.2, respectively) (P cranial bone grafting promotes resorption, possibly by increasing vascularization and osteoclastic activity. This technique cannot be recommended.

  12. Birth Defects

    Science.gov (United States)

    A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of ... in the United States is born with a birth defect. A birth defect may affect how the ...

  13. Three-dimensional culture of rat calvarial osteoblasts in porous biodegradable polymers

    Science.gov (United States)

    Ishaug-Riley, S. L.; Crane-Kruger, G. M.; Yaszemski, M. J.; Mikos, A. G.

    1998-01-01

    Neonatal rat calvarial osteoblasts were cultured in 90% porous, 75:25 poly(DL-lactic-co-glycolic acid) (PLGA) foam scaffolds for up to 56 days to examine the effects of the cell seeding density, scaffold pore size, and foam thickness on the proliferation and function of the cells in this three-dimensional environment. Osteoblasts were seeded at either 11.1 x 10(5) or 22.1 x 10(5) cells per cm2 onto PLGA scaffolds having pore sizes in the range of 150-300 or 500-710 microm with a thickness of either 1.9 or 3.2 mm. After 1 day in culture, 75.6 and 68.6% of the seeded cells attached and proliferated on the 1.9 mm thick scaffolds of 150-300 microm pore size for the low and high seeding densities, respectively. The number of osteoblasts continued to increase throughout the study and eventually leveled off near 56 days, as indicated by a quantitative DNA assay. Osteoblast/foam constructs with a low cell seeding density achieved comparable DNA content and alkaline phosphatase (ALPase) activity after 14 days, and mineralization results after 56 days to those with a high cell seeding density. A maximum penetration depth of osseous tissue of 220+/-40 microm was reached after 56 days in the osteoblast/foam constructs of 150-300 microm pore size initially seeded with a high cell density. For constructs of 500-710 microm pore size, the penetration depth was 190+/-40 microm under the same conditions. Scaffold pore size and thickness did not significantly affect the proliferation or function of osteoblasts as demonstrated by DNA content, ALPase activity, and mineralized tissue formation. These data show that comparable bone-like tissues can be engineered in vitro over a 56 day period using different rat calvarial osteoblast seeding densities onto biodegradable polymer scaffolds with pore sizes in the range of 150-710 microm. When compared with the results of a previous study where similar polymer scaffolds were seeded and cultured with marrow stromal cells, this study

  14. The first archaeometric data metallurgy in the cemetery and settlement of Calvari del Molar (Priorat, Tarragona

    Directory of Open Access Journals (Sweden)

    Armada Pita, Xosé-Lois

    2005-06-01

    Full Text Available The presence of Phoenician pottery along the course of the river Ebro has been linked to Phoenician interest in the mineral resources of the north-eastern Iberian Peninsula in general and the Molar-Bellmunt-Falset area in particular, but until now this proposition has not been verified. In this article we present the first evidence of metalworking from the site of Calvari del Molar (Priorat, Tarragona excavations of 2002-2003, which consists of a tuyère of a type hitherto unknown in Catalonia, a millstone used to crush ore, and an Orientalizing arrowhead that can be interpreted as a local imitation of foreign prototypes. The archaeometallurgical study of four other bronzes found during the excavations by S. Vilaseca (1930 is also included. Publication of these archaeological and archaeometrical results enables us to set out our proposals for future research on the settlement, its mining/metallurgical area and its relationship with Phoenician traders. Special attention is paid to silver, which was obtained from ores of that metal, from native silver and from lead sulphide.

    La presencia de materiales fenicios en el curso del río Ebro se ha relacionado con su interés hacia los recursos mineros del nordeste peninsular en general y del área Molar- Bellmunt-Falset en particular, pero hasta la fecha esta propuesta no había sido adecuadamente contrastada. En este artículo presentamos las primeras evidencias de actividad metalúrgica procedentes del poblado de Calvari del Molar (Priorat, Tarragona (campañas 2002-2003, que consisten en una tobera de tipología desconocida hasta la fecha en Cataluña, un molino empleado para triturar el mineral y una punta de flecha orientalizante que puede interpretarse como una imitación local de modelos foráneos. Damos a conocer también el estudio arqueometalúrgico de otros cuatro bronces procedentes de las excavaciones de S. Vilaseca (1930. La publicación de los resultados arqueológicos y arqueom

  15. Influence of template fill in graphoepitaxy DSA

    Science.gov (United States)

    Doise, Jan; Bekaert, Joost; Chan, Boon Teik; Hong, SungEun; Lin, Guanyang; Gronheid, Roel

    2016-03-01

    Directed self-assembly (DSA) of block copolymers (BCP) is considered a promising patterning approach for the 7 nm node and beyond. Specifically, a grapho-epitaxy process using a cylindrical phase BCP may offer an efficient solution for patterning randomly distributed contact holes with sub-resolution pitches, such as found in via and cut mask levels. In any grapho-epitaxy process, the pattern density impacts the template fill (local BCP thickness inside the template) and may cause defects due to respectively over- or underfilling of the template. In order to tackle this issue thoroughly, the parameters that determine template fill and the influence of template fill on the resulting pattern should be investigated. In this work, using three process flow variations (with different template surface energy), template fill is experimentally characterized as a function of pattern density and film thickness. The impact of these parameters on template fill is highly dependent on the process flow, and thus pre-pattern surface energy. Template fill has a considerable effect on the pattern transfer of the DSA contact holes into the underlying layer. Higher fill levels give rise to smaller contact holes and worse critical dimension uniformity. These results are important towards DSA-aware design and show that fill is a crucial parameter in grapho-epitaxy DSA.

  16. Modified concentric craniotomy for the removal of a huge calvarial metastatic tumor: technical note.

    Science.gov (United States)

    Kao, Ying; Yang, Shih-Hung; Kuo, Meng-Fai

    2016-02-01

    It is challenging for neurosurgeons to remove huge tumors involving the skull that may possibly invade the dura or intracranial neural tissue. In this situation, excision of the tumor may cause profound blood loss, unexpected opening of the dura, or neurological injury. We describe a technique of craniotomy in a pediatric patient to avoid surgical complications. A 15-year-old boy had a huge metastatic calvarial Ewing's sarcoma. We removed the tumor successfully with modified concentric craniotomy. First, two oval burr holes are made on both sides of the tumor. The inner craniotomy uses the internal margin of the oval holes, while the outer cut uses the outer margins. The skull bone in between the two craniotomies is removed easily in two pieces and the dura surrounding the tumor can be exposed early in the procedure. In this way, the huge skull tumor can be removed en bloc under direct vision to avoid unwanted complications. Minimal blood and bone loss can be achieved. Blood transfusion was not necessary during the surgery. The patient did not have new neurological symptoms and signs after surgery. The goal of the modified concentric craniotomy is to develop an accessible margin of the dura surrounding the bulky tumor in the early phase of surgery. Blood and bone loss can be reduced significantly.

  17. High-voltage leak detection of a parenteral proteinaceous solution product packaged in form-fill-seal plastic laminate bags. Part 2. Method performance as a function of heat seal defects, product-package refrigeration, and package plastic laminate lot.

    Science.gov (United States)

    Rasmussen, Mats; Damgaard, Rasmus; Buus, Peter; Mulhall, Brian; Guazzo, Dana Morton

    2013-01-01

    Part 1 of this three-part research series detailed the development and validation of a high-voltage leak detection test (HVLD, also known as an electrical conductivity and capacitance test) for verifying the container-closure integrity of a small-volume laminate plastic bag containing an aqueous solution formulation of the rapid-acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®) by Novo Nordisk A/S, Bagsværd, Denmark. Leak detection capability was verified using positive controls each with a single laser-drilled hole in the bag film face. In this Part 2, HVLD leak detection capability was further explored in four separate studies. Study 1 investigated the ability of HVLD to detect weaknesses and/or gaps in the bag heat seal. Study 2 checked the HVLD detection of bag holes in packages stored 4 days at ambient conditions followed by 17 days at refrigeration. Study 3 examined HVLD test results for packages tested when cold. Study 4 compared HVLD test results as a function of bag plastic film lots. The final Part 3 of this series will report the impact of HVLD exposure on product visual appearance and chemical stability. In Part 1 of this three-part series, a leak test method based on electrical conductivity and capacitance, also called high-voltage leak detection (HVLD), was used to find leaks in small plastic bags filled with a solution for injection of the rapid-acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®) by Novo Nordisk A/S, Bagsværd, Denmark. In this Part 2, HVLD leak detection capability was further explored in four separate studies. Study 1 investigated the ability of HVLD to detect bag heat seal leaks. Study 2 checked HVLD's ability to detect bag holes after a total of 21 days at ambient plus refrigerated temperatures. Study 3 looked to see if HVLD results changed for packages tested when still cold. Study 4 compared HVLD results for multiple bag plastic film lots. The final Part 3 of this series will report any evidence of

  18. Regulation of Calvarial Osteogenesis by Concomitant De-repression of GLI3 and Activation of IHH Targets

    Directory of Open Access Journals (Sweden)

    Lotta K. Veistinen

    2017-12-01

    Full Text Available Loss-of-function mutations in GLI3 and IHH cause craniosynostosis and reduced osteogenesis, respectively. In this study, we show that Ihh ligand, the receptor Ptch1 and Gli transcription factors are differentially expressed in embryonic mouse calvaria osteogenic condensations. We show that in both Ihh−/− and Gli3Xt−J/Xt−J embryonic mice, the normal gene expression architecture is lost and this results in disorganized calvarial bone development. RUNX2 is a master regulatory transcription factor controlling osteogenesis. In the absence of Gli3, RUNX2 isoform II and IHH are upregulated, and RUNX2 isoform I downregulated. This is consistent with the expanded and aberrant osteogenesis observed in Gli3Xt−J/Xt−J mice, and consistent with Runx2-I expression by relatively immature osteoprogenitors. Ihh−/− mice exhibited small calvarial bones and HH target genes, Ptch1 and Gli1, were absent. This indicates that IHH is the functional HH ligand, and that it is not compensated by another HH ligand. To decipher the roles and potential interaction of Gli3 and Ihh, we generated Ihh−/−;Gli3Xt−J/Xt−J compound mutant mice. Even in the absence of Ihh, Gli3 deletion was sufficient to induce aberrant precocious ossification across the developing suture, indicating that the craniosynostosis phenotype of Gli3Xt−J/Xt−J mice is not dependent on IHH ligand. Also, we found that Ihh was not required for Runx2 expression as the expression of RUNX2 target genes was unaffected by deletion of Ihh. To test whether RUNX2 has a role upstream of IHH, we performed RUNX2 siRNA knock down experiments in WT calvarial osteoblasts and explants and found that Ihh expression is suppressed. Our results show that IHH is the functional HH ligand in the embryonic mouse calvaria osteogenic condensations, where it regulates the progression of osteoblastic differentiation. As GLI3 represses the expression of Runx2-II and Ihh, and also elevates the Runx2-I expression

  19. Tyrosine kinase receptor c-ros-oncogene 1 inhibition alleviates aberrant bone formation of TWIST-1 haploinsufficient calvarial cells from Saethre-Chotzen syndrome patients.

    Science.gov (United States)

    Camp, Esther; Anderson, Peter J; Zannettino, Andrew C W; Glackin, Carlotta A; Gronthos, Stan

    2018-04-16

    Saethre-Chotzen syndrome (SCS), associated with TWIST-1 mutations, is characterized by premature fusion of cranial sutures. TWIST-1 haploinsufficiency, leads to alterations in suture mesenchyme cellular gene expression patterns, resulting in aberrant osteogenesis and craniosynostosis. We analyzed the expression of the TWIST-1 target, Tyrosine kinase receptor c-ros-oncogene 1 (C-ROS-1) in TWIST-1 haploinsufficient calvarial cells derived from SCS patients and calvaria of Twist-1 del/+ mutant mice and found it to be highly expressed when compared to TWIST-1 wild-type controls. Knock-down of C-ROS-1 expression in TWIST-1 haploinsufficient calvarial cells derived from SCS patients was associated with decreased capacity for osteogenic differentiation in vitro. Furthermore, treatment of human SCS calvarial cells with the tyrosine kinase chemical inhibitor, Crizotinib, resulted in reduced C-ROS-1 activity and the osteogenic potential of human SCS calvarial cells with minor effects on cell viability or proliferation. Cultured human SCS calvarial cells treated with Crizotinib exhibited a dose-dependent decrease in alkaline phosphatase activity and mineral deposition, with an associated decrease in expression levels of Runt-related transcription factor 2 and OSTEOPONTIN, with reduced PI3K/Akt signalling in vitro. Furthermore, Crizotinib treatment resulted in reduced BMP-2 mediated bone formation potential of whole Twist-1 del/+ mutant mouse calvaria organotypic cultures. Collectively, these results suggest that C-ROS-1 promotes osteogenic differentiation of TWIST-1 haploinsufficient calvarial osteogenic progenitor cells. Furthermore, the aberrant osteogenic potential of these cells is inhibited by the reduction of C-ROS-1. Therefore, targeting C-ROS-1 with a pharmacological agent, such as Crizotinib, may serve as a novel therapeutic strategy to alleviate craniosynostosis associated with aberrant TWIST-1 function. © 2018 Wiley Periodicals, Inc.

  20. Fill tube fitted spheres

    International Nuclear Information System (INIS)

    Ives, B.H.

    1981-01-01

    The high temperature diffusion technique for fuel filling of some future direct drive cryogenic ICF targets may be unacceptable. The following describes a technique of fitting a 1 mm diameter x 6 μm thick glass microsphere with an approx. 50 μm O.D. glass fill tube. The process of laser drilling a 50 μm diameter hole in the microsphere wall, technique for making the epoxy joint between the sphere and fill tube, as well as the assembly procedure are also discussed

  1. Gas-filled detectors

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter deals with the nature of the interaction of radiation with gas-filled radiation detectors. A description of the theory of operation of the ionization chamber and Geiger-Mueller counter is included

  2. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  3. DEFECTS SIMULATION OF ROLLING STRIP

    Directory of Open Access Journals (Sweden)

    Rudolf Mišičko

    2009-06-01

    Full Text Available The defects in the continuous casting slabs can be developed or kept down in principle by rolling technology, especially depend to sort, size and distribution of primary defects, as well as used of rolling parameters. Scope of the article is on observation behavior artificial surface and undersurface defects (scores without filler (surface defects and filling by oxides and casting powder (subsurface defects. First phase of hot rolling process have been done by software simulation DEFORM 3D setting to the limited condition for samples with surface defects. Samples of material with low-carbon steel of sizes h x b x l have been chosen and the surface defects shape „U” and „V” of scores have been injected artificially by software. The process of rolling have been simulated on the deformation temperatures 1200°C and 900°C, whereas on the both of this deformation temperatures have been applied amount of deformation 10 and 50 %. With respect to the process of computer simulation, it is not possible to truthful real oxidation condition (physical – chemical process during heat of metal, in the second phase of our investigation have been observed influence of oxides and casting powders inside the scores for a defect behavior in plastic deformation process (hot and cold rolling process in laboratory condition. The basic material was STN steel class 11 375, cladding material was steel on the bases C-Mn-Nb-V. Scores have been filled by scales to get from the heating temperatures (1100°C a 1250°C, varied types of casting powders, if you like mixture of scale and casting powders in the rate 1:4. The joint of the basic and cladding material have been done by peripheral welded joint. Experiment results from both phases are pointed on the evolution of original typology defects in rolling process.

  4. Osteogenic potential of a chalcone in a critical-size defect in rat calvaria bone.

    Science.gov (United States)

    Ortolan, Xana Raquel; Fenner, Bruna Proiss; Mezadri, Telmo José; Tames, David Rivero; Corrêa, Rogério; de Campos Buzzi, Fátima

    2014-07-01

    This study describes the bone formation stimulated by the application of a type of chalcone to critical-size defects in rat calvarial bone. Sixty female Wistar rats were divided into 6 groups of 10 animals per group: control (no treatment), vehicle (vaseline) and the chalcone (1-phenyl-3-(4-chlorophenyl)-2-propen-1-one) suspended in vaseline at 10%. A critical-size defect of 5 mm was prepared using a trephine in the calvarial bone, after which the treatment was applied, in a single dose, according to the experimental group. The samples were evaluated macroscopically using ImageJ software, and histologically 30 and 45 days after surgery. At 30 days after surgery, there was significant bone formation (p chalcone, compared with the other groups. Many active osteoblasts were observed adjacent to the borders of the newly formed bone tissue. 45 days after surgery in the chalcone group, the surgical defects showed complete bone closure. The results of this study suggest that chalcone has significant potential to induce the formation of new bone. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  5. Defects and defect processes in nonmetallic solids

    CERN Document Server

    Hayes, W

    2004-01-01

    This extensive survey covers defects in nonmetals, emphasizing point defects and point-defect processes. It encompasses electronic, vibrational, and optical properties of defective solids, plus dislocations and grain boundaries. 1985 edition.

  6. Space-filling Curves

    Indian Academy of Sciences (India)

    mathematics and computer applications for the last 20 years. He has been a National Science. Talent awardee of. NCERT in mathematics. GENERAL I ARTICLE. Space-filling Curves. ReMittal. In this article some Peano curves are exhibited and some of their recent applications are dis- cussed. A C++ program to draw the ...

  7. Gas filled detectors

    International Nuclear Information System (INIS)

    Stephan, C.

    1993-01-01

    The main types of gas filled nuclear detectors: ionization chambers, proportional counters, parallel-plate avalanche counters (PPAC) and microstrip detectors are described. New devices are shown. A description of the processes involved in such detectors is also given. (K.A.) 123 refs.; 25 figs.; 3 tabs

  8. Microstructure Filled Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reese, T. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-24

    We propose replacing the gas fill in a hohlraum with a low average density, variable uniformity 3D printed structure. This creates a bimodal hohlraum which acts like a vacuum hohlraum initially during the picket, but could protect the capsule from glint or direct illumination, and then once expanded, homogenizes to behave like a variable z gas-fill during peak portion of the drive. This is motivated by a two main aims: 1) reduction of the Au bubble velocity to improve inner beam propagation, and 2) the introduction of a low density, high-Z, x-ray converter to improve x-ray production in the hohlraum and uniformity of the radiation field seen by the capsule.

  9. Bone regeneration in 3D printing bioactive ceramic scaffolds with improved tissue/material interface pore architecture in thin-wall bone defect.

    Science.gov (United States)

    Shao, Huifeng; Ke, Xiurong; Liu, An; Sun, Miao; He, Yong; Yang, Xianyan; Fu, Jianzhong; Liu, Yanming; Zhang, Lei; Yang, Guojing; Xu, Sanzhong; Gou, Zhongru

    2017-04-12

    Three-dimensional (3D) printing bioactive ceramics have demonstrated alternative approaches to bone tissue repair, but an optimized materials system for improving the recruitment of host osteogenic cells into the bone defect and enhancing targeted repair of the thin-wall craniomaxillofacial defects remains elusive. Herein we systematically evaluated the role of side-wall pore architecture in the direct-ink-writing bioceramic scaffolds on mechanical properties and osteogenic capacity in rabbit calvarial defects. The pure calcium silicate (CSi) and dilute Mg-doped CSi (CSi-Mg6) scaffolds with different layer thickness and macropore sizes were prepared by varying the layer deposition mode from single-layer printing (SLP) to double-layer printing (DLP) and then by undergoing one-, or two-step sintering. It was found that the dilute Mg doping and/or two-step sintering schedule was especially beneficial for improving the compressive strength (∼25-104 MPa) and flexural strength (∼6-18 MPa) of the Ca-silicate scaffolds. The histological analysis for the calvarial bone specimens in vivo revealed that the SLP scaffolds had a high osteoconduction at the early stage (4 weeks) but the DLP scaffolds displayed a higher osteogenic capacity for a long time stage (8-12 weeks). Although the DLP CSi scaffolds displayed somewhat higher osteogenic capacity at 8 and 12 weeks, the DLP CSi-Mg6 scaffolds with excellent fracture resistance also showed appreciable new bone tissue ingrowth. These findings demonstrate that the side-wall pore architecture in 3D printed bioceramic scaffolds is required to optimize for bone repair in calvarial bone defects, and especially the Mg doping wollastontie is promising for 3D printing thin-wall porous scaffolds for craniomaxillofacial bone defect treatment.

  10. Use of autologous platelet - Rich plasma in the treatment of intrabony defects

    Directory of Open Access Journals (Sweden)

    Sharath K Shetty

    2009-01-01

    Treatment of intrabony defects by autologous PRP gel alone caused significant soft tissue clinical improvement as well as hard tissue defect fill as evidenced by SSD view in spiral computed tomography.

  11. Embedded defects

    International Nuclear Information System (INIS)

    Barriola, M.; Vachaspati, T.; Bucher, M.

    1994-01-01

    We give a prescription for embedding classical solutions and, in particular, topological defects in field theories which are invariant under symmetry groups that are not necessarily simple. After providing examples of embedded defects in field theories based on simple groups, we consider the electroweak model and show that it contains the Z string and a one-parameter family of strings called the W(α) string. It is argued that although the members of this family are gauge equivalent when considered in isolation, each member becomes physically distinct when multistring configurations are considered. We then turn to the issue of stability of embedded defects and demonstrate the instability of a large class of such solutions in the absence of bound states or condensates. The Z string is shown to be unstable for all values of the Higgs boson mass when θ W =π/4. W strings are also shown to be unstable for a large range of parameters. Embedded monopoles suffer from the Brandt-Neri-Coleman instability. Finally, we connect the electroweak string solutions to the sphaleron

  12. Filled/Eroded Craters

    Science.gov (United States)

    2005-01-01

    14 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows rugged terrain in northern Arabia Terra. The circular features are the remains of old meteor impact craters -- either the eroded remnants of the interiors of craters, or the remains of craters that were filled by layered material. The martian bedrock has craters of all sizes and states of erosion interbedded with its layered materials. Location near: 31.4oN, 299.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  13. Fluid Dynamics of Bottle Filling

    Science.gov (United States)

    McGough, Patrick; Gao, Haijing; Appathurai, Santosh; Basaran, Osman

    2011-11-01

    Filling of bottles is a widely practiced operation in a large number of industries. Well known examples include filling of ``large'' bottles with shampoos and cleaners in the household products and beauty care industries and filling of ``small'' bottles in the pharmaceutical industry. Some bottle filling operations have recently drawn much attention from the fluid mechanics community because of the occurrence of a multitude of complex flow regimes, transitions, and instabilities such as mounding and coiling that occur as a bottle is filled with a fluid. In this talk, we present a primarily computational study of the fluid dynamical challenges that can arise during the rapid filling of bottles. Given the diversity of fluids used in filling applications, we consider four representative classes of fluids that exhibit Newtonian, shear-thinning, viscoelastic, and yield-stress rheologies. The equations governing the dynamics of bottle filling are solved either in their full 3D but axisymmetric form or using the slender-jet approximation.

  14. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  15. Osterix-Cre transgene causes craniofacial bone development defect

    Science.gov (United States)

    Wang, Li; Mishina, Yuji; Liu, Fei

    2015-01-01

    The Cre/loxP system has been widely used to generate tissue-specific gene knockout mice. Inducible (Tet-off) Osx-GFP::Cre (Osx-Cre) mouse line that targets osteoblasts is widely used in the bone research field. In this study, we investigated the effect of Osx-Cre on craniofacial bone development. We found that newborn Osx-Cre mice showed severe hypomineralization in parietal, frontal, and nasal bones as well as the coronal sutural area when compared to control mice. As the mice matured the intramembranous bone hypomineralization phenotype became less severe. The major hypomineralization defect in parietal, frontal, and nasal bones had mostly disappeared by postnatal day 21, but the defect in sutural areas persisted. Importantly, Doxycycline treatment eliminated cranial bone defects at birth which indicates that Cre expression may be responsible for the phenotype. In addition, we showed that the primary calvarial osteoblasts isolated from neonatal Osx-Cre mice had comparable differentiation ability compared to their littermate controls. This study reinforces the idea that Cre positive litter mates are indispensable controls in studies using conditional gene deletion. PMID:25550101

  16. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  17. Magnetoencephalography signals are influenced by skull defects.

    Science.gov (United States)

    Lau, S; Flemming, L; Haueisen, J

    2014-08-01

    Magnetoencephalography (MEG) signals had previously been hypothesized to have negligible sensitivity to skull defects. The objective is to experimentally investigate the influence of conducting skull defects on MEG and EEG signals. A miniaturized electric dipole was implanted in vivo into rabbit brains. Simultaneous recording using 64-channel EEG and 16-channel MEG was conducted, first above the intact skull and then above a skull defect. Skull defects were filled with agar gels, which had been formulated to have tissue-like homogeneous conductivities. The dipole was moved beneath the skull defects, and measurements were taken at regularly spaced points. The EEG signal amplitude increased 2-10 times, whereas the MEG signal amplitude reduced by as much as 20%. The EEG signal amplitude deviated more when the source was under the edge of the defect, whereas the MEG signal amplitude deviated more when the source was central under the defect. The change in MEG field-map topography (relative difference measure, RDM(∗)=0.15) was geometrically related to the skull defect edge. MEG and EEG signals can be substantially affected by skull defects. MEG source modeling requires realistic volume conductor head models that incorporate skull defects. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  18. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  19. Interdisciplinary Management of an Isolated Intrabony Defect

    Directory of Open Access Journals (Sweden)

    Sheetal Ghivari

    2014-01-01

    Full Text Available The treatment of intrabony defects is a real challenge in molar teeth as it is chronic, slowly progressing disease which needs timely intervention. Periodontal inflammation associated with intrabony defect is not a separate entity as it secondarily affects the pulp causing retrograde pulpitis. However, treatment of these lesions will be complicated due to extensive bone loss. The tooth was endodontically treated followed by periodontal surgery to eliminate the deep periodontal pocket and promote bone fill in osseous defect. PepGen P-15 composited with platelet rich plasma was utilized for enhancing bone formation. The combination of these graft materials provides synergistic effect on bone regeneration.

  20. Electrospun PLLA nanofiber scaffolds and their use in combination with BMP-2 for reconstruction of bone defects.

    Science.gov (United States)

    Schofer, Markus D; Roessler, Philip P; Schaefer, Jan; Theisen, Christina; Schlimme, Sonja; Heverhagen, Johannes T; Voelker, Maximilian; Dersch, Roland; Agarwal, Seema; Fuchs-Winkelmann, Susanne; Paletta, Jürgen R J

    2011-01-01

    Adequate migration and differentiation of mesenchymal stem cells is essential for regeneration of large bone defects. To achieve this, modern graft materials are becoming increasingly important. Among them, electrospun nanofiber scaffolds are a promising approach, because of their high physical porosity and potential to mimic the extracellular matrix (ECM). The objective of the present study was to examine the impact of electrospun PLLA nanofiber scaffolds on bone formation in vivo, using a critical size rat calvarial defect model. In addition we analyzed whether direct incorporation of bone morphogenetic protein 2 (BMP-2) into nanofibers could enhance the osteoinductivity of the scaffolds. Two critical size calvarial defects (5 mm) were created in the parietal bones of adult male Sprague-Dawley rats. Defects were either (1) left unfilled, or treated with (2) bovine spongiosa, (3) PLLA scaffolds alone or (4) PLLA/BMP-2 scaffolds. Cranial CT-scans were taken at fixed intervals in vivo. Specimens obtained after euthanasia were processed for histology, histomorphometry and immunostaining (Osteocalcin, BMP-2 and Smad5). PLLA scaffolds were well colonized with cells after implantation, but only showed marginal ossification. PLLA/BMP-2 scaffolds showed much better bone regeneration and several ossification foci were observed throughout the defect. PLLA/BMP-2 scaffolds also stimulated significantly faster bone regeneration during the first eight weeks compared to bovine spongiosa. However, no significant differences between these two scaffolds could be observed after twelve weeks. Expression of osteogenic marker proteins in PLLA/BMP-2 scaffolds continuously increased throughout the observation period. After twelve weeks osteocalcin, BMP-2 and Smad5 were all significantly higher in the PLLA/BMP-2 group than in all other groups. Electrospun PLLA nanofibers facilitate colonization of bone defects, while their use in combination with BMP-2 also increases bone regeneration in

  1. Electrospun PLLA nanofiber scaffolds and their use in combination with BMP-2 for reconstruction of bone defects.

    Directory of Open Access Journals (Sweden)

    Markus D Schofer

    Full Text Available Adequate migration and differentiation of mesenchymal stem cells is essential for regeneration of large bone defects. To achieve this, modern graft materials are becoming increasingly important. Among them, electrospun nanofiber scaffolds are a promising approach, because of their high physical porosity and potential to mimic the extracellular matrix (ECM.The objective of the present study was to examine the impact of electrospun PLLA nanofiber scaffolds on bone formation in vivo, using a critical size rat calvarial defect model. In addition we analyzed whether direct incorporation of bone morphogenetic protein 2 (BMP-2 into nanofibers could enhance the osteoinductivity of the scaffolds. Two critical size calvarial defects (5 mm were created in the parietal bones of adult male Sprague-Dawley rats. Defects were either (1 left unfilled, or treated with (2 bovine spongiosa, (3 PLLA scaffolds alone or (4 PLLA/BMP-2 scaffolds. Cranial CT-scans were taken at fixed intervals in vivo. Specimens obtained after euthanasia were processed for histology, histomorphometry and immunostaining (Osteocalcin, BMP-2 and Smad5.PLLA scaffolds were well colonized with cells after implantation, but only showed marginal ossification. PLLA/BMP-2 scaffolds showed much better bone regeneration and several ossification foci were observed throughout the defect. PLLA/BMP-2 scaffolds also stimulated significantly faster bone regeneration during the first eight weeks compared to bovine spongiosa. However, no significant differences between these two scaffolds could be observed after twelve weeks. Expression of osteogenic marker proteins in PLLA/BMP-2 scaffolds continuously increased throughout the observation period. After twelve weeks osteocalcin, BMP-2 and Smad5 were all significantly higher in the PLLA/BMP-2 group than in all other groups.Electrospun PLLA nanofibers facilitate colonization of bone defects, while their use in combination with BMP-2 also increases bone

  2. Vertical osteoconductivity of sputtered hydroxyapatite-coated mini titanium implants after dura mater elevation: Rabbit calvarial model

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2016-03-01

    Full Text Available This study evaluated the quantity and quality of newly formed vertical bone induced by sputtered hydroxyapatite-coated titanium implants compared with sandblasted acid-etched implants after dura mater elevation. Hydroxyapatite-coated and non-coated implants (n = 20/group were used and divided equally into two groups. All implants were randomly placed into rabbit calvarial bone (four implants for each animal emerging from the inferior cortical layer, displacing the dura mater 3 mm below the original bone. Animals were sacrificed at 4 (n = 5 and 8 (n = 5 weeks post-surgery. Vertical bone height and area were analyzed histologically and radiographically below the original bone. Vertical bone formation was observed in both groups. At 4 and 8 weeks, vertical bone height reached a significantly higher level in the hydroxyapatite compared with the non-coated group (p < 0.05. Vertical bone area was significantly larger in the hydroxyapatite compared with the non-coated group at 4 and 8 weeks (p < 0.05. This study indicates that vertical bone formation can be induced by dura mater elevation and sputtered hydroxyapatite coating can enhance vertical bone formation.

  3. Mistura de proteínas morfogenéticas ósseas, hidroxiapatita, osso inorgânico e colágeno envolta por membrana de pericárdio no preenchimento de defeito ósseo segmentar em coelhos Mixture of bone morphogenetic protein, hydroxyapatite, inorganic bone and collagen interposed by pericardium barrier membrane in the filling of the segmental bone defect in rabbits

    Directory of Open Access Journals (Sweden)

    R.B. Ciani

    2006-02-01

    Full Text Available Avaliou-se o uso de biomaterial de origem bovina na regeneração de defeitos ósseos segmentares empregando-se 12 coelhos, fêmeas, da raça Norfolk, com idade de seis meses e pesos entre 3 e 4,5kg. Realizou-se falha segmentar bilateral de um centímetro de comprimento na diáfise do rádio, com inclusão do periósteo. No membro direito, o defeito foi delimitado por membrana de pericárdio liofilizada, contendo em seu interior mistura de proteínas morfogenéticas ósseas adsorvidas a hidroxiapatita, colágeno liofilizado e osso inorgânico. No membro esquerdo, o defeito não recebeu tratamento. Radiografias foram obtidas ao término do procedimento cirúrgico e aos sete, 30, 60, 90, 120 e 150 dias de pós-operatório. Após eutanásia de seis coelhos aos 60 dias e seis aos 150 dias de pós-cirúrgico, os resultados radiográficos e histológicos mostraram que a regeneração óssea foi inibida nos defeitos segmentares tratados com o biomaterial.Biomaterials of bovine origin in regenerating segmental bone defects were evaluated. Twelve six-month old Norfolk rabbits, weighting 3 to 4.5kg were used. A 1cm long segmental defect was created in the radial diaphysis, including the periosteum, of both forelimbs. In the right forelimb, the defect was filled using a mixture of bone morphogenic proteins adsorbed to hydroxyapatite, agglutinant of lyophilized collagen in granules and anorganic cortical bone in granules delimited by a pericardial membrane. In the left forelimb, the defect did not receive treatment and served as a control. Radiographies were taken immediately after surgery and at seven, 30, 60, 90, 120 and 150 days post-operatively. Six rabbits were euthanized at 60 days and the other six at 150 days post-surgery for histological evaluation. Radiographic and histological results revealed that bone regeneration was inhibited in the segmental defects receiving biomaterials.

  4. Coagulation defects.

    Science.gov (United States)

    Soliman, Doreen E; Broadman, Lynn M

    2006-09-01

    The present understanding of the coagulation process emphasizes the final common pathway and the proteolytic systems that result in the degradation of formed clots and the prevention of unwanted clot formations, as well as a variety of defense systems that include tissue repair, autoimmune processes, arteriosclerosis, tumor growth, the spread of metastases, and defense systems against micro-organisms. This article discusses diagnosis and management of some of the most common bleeding disorders. The goals are to provide a simple guide on how best to manage patients afflicted with congenital or acquired clotting abnormalities during the perioperative period, present a brief overview of the methods of testing and monitoring the coagulation defects, and discuss the appropriate pharmacologic or blood component therapies for each disease.

  5. Repair of a large congenital frontal bone defect with autologous exchange cranioplasty.

    Science.gov (United States)

    Ropper, Alexander E; Rogers, Gary F; Ridgway, Emily B; Proctor, Mark R

    2010-11-01

    The authors report the case of a large idiopathic frontal bone defect and concomitant sagittal synostosis corrected by autologous exchange cranioplasty by using a corticocancellous bone graft and cranial vault expansion. An otherwise healthy, developmentally normal 6-year-old girl presented to our clinic with a large frontal bone defect. The osseous defect was midline and inferior to the coronal sutures, and the underlying dura was slightly tense. She had no signs or symptoms of increased intracranial pressure, and her head circumference and cephalic index were normal. Imaging demonstrated fusion of the sagittal synostosis. The defect was repaired using full-thickness autologous bone harvested from the bilateral parietal regions, which were widened using barrel-stave osteotomies to reduce pressure on the graft site in the setting of sagittal synostosis and mild cranial narrowing. The donor sites were covered with autologous particulate bone graft harvested from the endocortical surface of the grafted segments and the ectocortical surface of the intact parietal bones. The donor and recipient sites healed. Imaging revealed that the particulate bone healed with a thickness similar to the surrounding bone. This bony defect is analogous to parietal foramina and may have a similar etiopathogenesis. The technique of autologous exchange cranioplasty using corticocancellous particulate bone graft provides a simple and reliable method to repair large structural calvarial defects.

  6. Low-level laser therapy vs. pulsed electromagnetic field on neonatal rat calvarial osteoblast-like cells.

    Science.gov (United States)

    Emes, Yusuf; Akça, Kivanç; Aybar, Buket; Yalçın, Serhat; Çavuşoğlu, Yeliz; Baysal, Uğur; Işsever, Halim; Atalay, Belir; Vural, Pervin; Ergüven, Mine; Çehreli, Murat Cavit; Bilir, Ayhan

    2013-05-01

    To compare the effects of pulsed electromagnetic field (PEMF) and low-level laser therapy (LLLT) on osteoblast cells in a cell culture model. Fifty thousand neonatal rat calvarial osteoblast-like cells per milliliter were seeded and 0.06 mT PEMF, 0.2 mT PEMF, and LLLT at 808 nm were applied for 24 and 96 h on the cells. To evaluate cellular proliferation and differentiation, specimens were examined for DNA synthesis, alkaline phosphatase (ALP) activity, cell numbers, and viability of the cells. Morphological appearances of the cells were observed using scanning electron microcopy after 24 and 96 h of incubation. At 24 and 96 h, the control group had a higher cell proliferation than 0.06 and 0.2 mT PEMF groups (p=0.001). At 96 h, 0.2 mT PEMF group had higher cell proliferation rate than 0.06 mT PEMF and LLLT groups (p=0.001). The cell count and cell viability in 0.2 mT PEMF group were higher than the 0.06-mT PEMF and LLLT groups, although these differences were not statistically significant at 96 h (p>0.05). At 24 and 96 h, cell viability in the control group was higher than the test groups. Alkaline phosphatase levels of the groups were comparable in both time intervals (p>0.05). 0.2 mT PEMF application on osteoblast-like cells led to cell proliferation and differentiation better than 0.06 mT PEMF and LLLT at 808 nm, although a remarkable effect of both PEMF and LLLT could not be detected. The ALP activity of 0.2 and 0.06 mT PEMF and LLLT were comparable.

  7. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  8. Effect of via depth on the TSV filling process for different current densities

    Science.gov (United States)

    Wang, Feng; Zhao, Zhipeng; Nie, Nantian; Wang, Fuliang; Zhu, Wenhui

    2018-04-01

    Through-silicon-via (TSV) filling with optimum electrodeposition parameters is still a challenge in the industry, especially for via with different depths. Herein, the effects of via depth on optimum current density and filling patterns were investigated. It was found that the deeper the via, the lower the optimum current density. At low current density (4 mA cm-2), the via depth only affects the size of the defect, but does not change the filling pattern. However, at medium current density (7 mA cm-2), the filling pattern changes from super-conformal filling to sub-conformal filling with the increase of via depth, the pinch-off position remaining constant at a depth of about 70 µm from the top surface. Simulations of the TSV filling process using COMSOL modeling software revealed that the local concentration of additives, which is affected by the via depth, determine the morphology of the electrodeposition, matching well the experimental results.

  9. Radiopacity of root filling materials

    International Nuclear Information System (INIS)

    Beyer-Olsen, E.M.

    1983-01-01

    A method for measuring the radiopacity of root filling materials is described. Direct measurements were made of the optic density values of the materials in comparison with a standard curve relating optic density to the thickness of an aluminium step wedge exposed simultaneously. By proper selection of film and conditions for exposure and development, it was possible to obtain a near-linear standard curve which added to the safety and reproducibility of the method. The technique of radiographic assessment was modified from clinical procedures in evaluating the obturation in radiographs, and it was aimed at detecting slits or voids between the dental wall and the filling material. This radiographic assessment of potensial leakage was compared with actual in vitro lekage of dye (basic fuchsin) into the roots of filled teeth. The result of the investigation show that root filling materials display a very wide range of radiopacity, from less than 3 mm to more than 12 mm of aluminium. It also seem that tooth roots that appear to be well obturated by radiographic evaluation, stand a good chance of beeing resistant to leakage in vitro, and that the type of filling material rather than its radiographic appearance, determines the susceptibility of the filled tooth to leakage in vitro. As an appendix the report contains a survey of radiopaque additives in root filling materials

  10. Root canal filling evaluation using optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Topala, Florin; Nica, Luminita; Ionita, Ciprian; Marcauteanu, Corina; Goguta, Luciana; Bradu, Adrian; Dobre, George; Rominu, Mihai; Podoleanu, Adrian Gh.

    2010-04-01

    Endodontic therapy consists in cleaning and shaping the root canal system, removing organic debris and sealing the intra-canal space with permanent filling materials. The purpose of this study was to evaluate various root canal fillings in order to detect material defects, the marginal adaptation at the root canal walls and to assess the quality of the apical sealing. 21 extracted single-root canal human teeth were selected for this study. We instrumented all roots using NiTi rotary instruments. All canals were enlarged with a 6% taper size 30 GT instrument, 0,5 mm from the anatomical apex. The root canals were irrigated with 5% sodium hypochlorite, followed by 17% ethylenediaminetetraacetic acid (EDTA). After the instrumentation was completed, the root canals were obturated using a thermoplasticizable polymer of polyesters. In order to assess the defects inside the filling material and the marginal fit to the root canal walls, the conebeam micro-computed tomography (CBμCT) was used first. After the CBμCT investigation, time domain optical coherence tomography working in en face mode (TDefOCT) was employed to evaluate the previous samples. The TDefOCT system was working at 1300 nm and was doubled by a confocal channel at 970 nm. The results obtained by CBμCT revealed no visible defects inside the root-canal fillings and at the interfaces with the root-canal walls. TDefOCT investigations permit to visualize a more complex stratificated structure at the interface filling material/dental hard tissue and in the apical region.

  11. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  12. Attachment and proliferation of neonatal rat calvarial osteoblasts on Ti6Al4V: effect of surface chemistries of the alloy.

    Science.gov (United States)

    Lee, T M; Chang, E; Yang, C Y

    2004-01-01

    This study examined the cell attachment and proliferation of neonatal rat calvarial osteoblasts on Ti6Al4V alloy as affected by the surface modifications. The modifications could alter simultaneously the surface chemistries of the alloy (elemental difference of Ti, Al, V, Cu and Ni about 300-600mum thick examined by EDS) as well as the XPS nano-surface characteristics of oxides on the metal surface (chemistries of oxides, amphoteric OH group adsorbed on oxides, and oxide thickness). Three materials including two from modifications and a control were examined. It is argued that a slight change of the nano-surface characteristics of oxides as a result of the modifications neither alters the in vitro capability of Ca and P ion adsorption nor affects the metal ion dissolution behavior of the alloy. This implies that any influence on the cytocompatibility of the materials should only be correlated to the effect of surface chemistries of the alloy and the associated metal ion dissolution behavior of the alloy. The experimental results suggest that the cell response of neonatal rat calvarial osteoblasts on the Ti6Al4V alloy should neither be affected by the variation of surface chemistries of the alloy in a range studied.

  13. Onlay bone augmentation on mouse calvarial bone using a hydroxyapatite/collagen composite material with total blood or platelet-rich plasma.

    Science.gov (United States)

    Ohba, Seigo; Sumita, Yoshinori; Umebayashi, Mayumi; Yoshimura, Hitoshi; Yoshida, Hisato; Matsuda, Shinpei; Kimura, Hideki; Asahina, Izumi; Sano, Kazuo

    2016-01-01

    The aim of this study was to assess newly formed onlay bone on mouse calvarial bone using a new artificial bone material, a hydroxyapatite/collagen composite, with total blood or platelet-rich plasma. The hydroxyapatite/collagen composite material with normal saline, total blood or platelet-rich plasma was transplanted on mouse calvarial bone. The mice were sacrificed and the specimens were harvested four weeks after surgery. The newly formed bone area was measured on hematoxylin and eosin stained specimens using Image J software. The hydroxyapatite/collagen composite materials with total blood or platelet-rich plasma induced a significantly greater amount of newly formed bone than that with normal saline. Moreover, bone marrow was observed four weeks after surgery in the transplanted materials with total blood or platelet-rich plasma but not with normal saline. However, there were no significant differences in the amount of newly formed bone between materials used with total blood versus platelet-rich plasma. The hydroxyapatite/collagen composite material was valid for onlay bone augmentation and this material should be soaked in total blood or platelet-rich plasma prior to transplantation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Effects of high-frequency near-infrared diode laser irradiation on the proliferation and migration of mouse calvarial osteoblasts.

    Science.gov (United States)

    Kunimatsu, Ryo; Gunji, Hidemi; Tsuka, Yuji; Yoshimi, Yuki; Awada, Tetsuya; Sumi, Keisuke; Nakajima, Kengo; Kimura, Aya; Hiraki, Tomoka; Abe, Takaharu; Naoto, Hirose; Yanoshita, Makoto; Tanimoto, Kotaro

    2018-01-04

    Laser irradiation activates a range of cellular processes and can promote tissue repair. Here, we examined the effects of high-frequency near-infrared (NIR) diode laser irradiation on the proliferation and migration of mouse calvarial osteoblastic cells (MC3T3-E1). MC3T3-E1 cells were cultured and exposed to high-frequency (30 kHz) 910-nm diode laser irradiation at a dose of 0, 1.42, 2.85, 5.7, or 17.1 J/cm 2 . Cell proliferation was evaluated with BrdU and ATP concentration assays. Cell migration was analyzed by quantitative assessment of wound healing using the Incucyt ® ZOOM system. In addition, phosphorylation of mitogen-activated protein kinase (MAPK) family members including p38 mitogen-activated protein kinase (p38), stress-activated protein kinase/Jun-amino-terminal kinase (SAPK/JNK), and extracellular signal-regulated protein kinase (ERK)1/2) after laser irradiation was examined with western blotting. Compared to the control, cell proliferation was significantly increased by laser irradiation at a dose of 2.85, 5.7, or 17.1 J/cm 2 . Laser irradiation at a dose of 2.85 J/cm 2 induced MC3T3-E1 cells to migrate more rapidly than non-irradiated control cells. Irradiation with the high-frequency 910-nm diode laser at a dose of 2.85 J/cm 2 induced phosphorylation of MAPK/ERK1/2 15 and 30 min later. However, phosphorylation of p38 MAPK and SAPK/JNK was not changed by NIR diode laser irradiation at a dose of 2.85 J/cm 2 . Irradiation with a high-frequency NIR diode laser increased cell division and migration of MT3T3-E1 cells, possibly via MAPK/ERK signaling. These observations may be important for enhancing proliferation and migration of osteoblasts to improve regeneration of bone tissues.

  15. Safe Harvesting of Outer Table Parietal Bone Grafts Using an Oscillating Saw and a Bone Scraper : A Refinement of Technique for Harvesting Cortical and "Cancellous"-Like Calvarial Bone

    NARCIS (Netherlands)

    Schortinghuis, Jurjen; Putters, Thomas F.; Raghoebar, Gerry M.

    Calvarial bone is a readily available source of bone for preimplantation augmentation procedures of the alveolar process. However, the calvaria consist mostly of cortical bone, and cancellous bone of the diploic space is scarce. A bone scraper (Safescraper Twist; META, Reggio Emilia, Italy) was used

  16. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it More sharing options ... it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell that is filled ...

  17. Spectrally Compatible Iterative Water Filling

    Science.gov (United States)

    Verlinden, Jan; Bogaert, Etienne Vanden; Bostoen, Tom; Zanier, Francesca; Luise, Marco; Cendrillon, Raphael; Moonen, Marc

    2006-12-01

    Until now static spectrum management has ensured that DSL lines in the same cable are spectrally compatible under worst-case crosstalk conditions. Recently dynamic spectrum management (DSM) has been proposed aiming at an increased capacity utilization by adaptation of the transmit spectra of DSL lines to the actual crosstalk interference. In this paper, a new DSM method for downstream ADSL is derived from the well-known iterative water-filling (IWF) algorithm. The amount of boosting of this new DSM method is limited, such that it is spectrally compatible with ADSL. Hence it is referred to as spectrally compatible iterative water filling (SC-IWF). This paper focuses on the performance gains of SC-IWF. This method is an autonomous DSM method (DSM level 1) and it will be investigated together with two other DSM level-1 algorithms, under various noise conditions, namely, iterative water-filling algorithm, and flat power back-off (flat PBO).

  18. Spectrally Compatible Iterative Water Filling

    Directory of Open Access Journals (Sweden)

    Cendrillon Raphael

    2006-01-01

    Full Text Available Until now static spectrum management has ensured that DSL lines in the same cable are spectrally compatible under worst-case crosstalk conditions. Recently dynamic spectrum management (DSM has been proposed aiming at an increased capacity utilization by adaptation of the transmit spectra of DSL lines to the actual crosstalk interference. In this paper, a new DSM method for downstream ADSL is derived from the well-known iterative water-filling (IWF algorithm. The amount of boosting of this new DSM method is limited, such that it is spectrally compatible with ADSL. Hence it is referred to as spectrally compatible iterative water filling (SC-IWF. This paper focuses on the performance gains of SC-IWF. This method is an autonomous DSM method (DSM level 1 and it will be investigated together with two other DSM level-1 algorithms, under various noise conditions, namely, iterative water-filling algorithm, and flat power back-off (flat PBO.

  19. Gas-Filled Capillary Model

    International Nuclear Information System (INIS)

    Steinhauer, L. C.; Kimura, W. D.

    2006-01-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration -- Laser Wakefield (STELLA-LW) experiment

  20. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  1. Defect of the Eyelids.

    Science.gov (United States)

    Lu, Guanning Nina; Pelton, Ron W; Humphrey, Clinton D; Kriet, John David

    2017-08-01

    Eyelid defects disrupt the complex natural form and function of the eyelids and present a surgical challenge. Detailed knowledge of eyelid anatomy is essential in evaluating a defect and composing a reconstructive plan. Numerous reconstructive techniques have been described, including primary closure, grafting, and a variety of local flaps. This article describes an updated reconstructive ladder for eyelid defects that can be used in various permutations to solve most eyelid defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Filling of charged cylindrical capillaries

    NARCIS (Netherlands)

    Das, S.; Chanda, Sourayon; Eijkel, Jan C.T.; Tas, Niels Roelof; Chakraborty, Suman; Mitra, Sushanta K.

    2014-01-01

    We provide an analytical model to describe the filling dynamics of horizontal cylindrical capillaries having charged walls. The presence of surface charge leads to two distinct effects: It leads to a retarding electrical force on the liquid column and also causes a reduced viscous drag force because

  3. 3D printing cybersecurity: detecting and preventing attacks that seek to weaken a printed object by changing fill level

    Science.gov (United States)

    Straub, Jeremy

    2017-06-01

    Prior work by Zeltmann, et al. has demonstrated the impact of small defects and other irregularities on the structural integrity of 3D printed objects. It posited that such defects could be introduced intentionally. The current work looks at the impact of changing the fill level on object structural integrity. It considers whether the existence of an appropriate level of fill can be determined through visible light imagery-based assessment of a 3D printed object. A technique for assessing the quality and sufficiency of quantity of 3D printed fill material is presented. It is assessed experimentally and results are presented and analyzed.

  4. On holographic defect entropy

    Energy Technology Data Exchange (ETDEWEB)

    Estes, John [Blackett Laboratory, Imperial College,London SW7 2AZ (United Kingdom); Jensen, Kristan [Department of Physics and Astronomy, University of Victoria,Victoria, BC V8W 3P6 (Canada); C.N. Yang Institute for Theoretical Physics, SUNY Stony Brook,Stony Brook, NY 11794-3840 (United States); O’Bannon, Andy [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford OX1 3NP (United Kingdom); Tsatis, Efstratios [8 Kotylaiou Street, Athens 11364 (Greece); Wrase, Timm [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States)

    2014-05-19

    We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions.

  5. On holographic defect entropy

    Science.gov (United States)

    Estes, John; Jensen, Kristan; O'Bannon, Andy; Tsatis, Efstratios; Wrase, Timm

    2014-05-01

    We study a number of (3 + 1)- and (2 + 1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3 + 1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1 + 1)-dimensional field theories generalizes to higher dimensions.

  6. Lyophilized allogeneic bone grafts for cystic and discontinuity defects of the jaws

    International Nuclear Information System (INIS)

    Pill Hoon Choung; Eun Seok Kim

    1999-01-01

    Allogenic bone grafts have been used after various processing in each institute was made by lyophilized allogenic bone and used for maxillofacial reconstruction. Three types of lyophilized allogenic bone grafts as powder, chip and block form were performed to reconstruct the following defects: 1) maxillectomy, 2) mandiblectomy, 3) cystectomy, 4) cleft alveolus, 5) gap in orthognathic osteotomy, 6) peri-implant defect, 7) extraction socket, and 8) facial contouring. Above defects can be classified as cystic and discontinuity defects of the maxilia and the mandible. Because discontinuity defects have more difficult problems to reconstruct considering mechanical strength of the allogenic bone. We performed allogenic bone grafts on 50 cystic defects and 12 discontinuity defects of the jaws. Among them, 3 cases were removed due to infection, and the others had no complications. In reconstruction of cystic defects, the defects were filled with allogenic chip which were made from allogenic block bone at the surgery, which later were changed to host bone. Three cases of them showed tooth eruption through the allogenic bone grafting site, changing the eruption pathway, which was interrupted by the lesion. in reconstruction of discontinuity defects, usually allogenic bone has been used as a tray, in which PMCB or demineralized bone chips were filled. But we tried to reconstruct this discontinuity defect using allogeneic bone block without inside filling of PMCB different from tray type. We will present the results of allogenic bone grafts using cranial bone, costochondral graft, and the mandible

  7. Composite Biomaterial as a Carrier for Bone-Active Substances for Metaphyseal Tibial Bone Defect Reconstruction in Rats

    DEFF Research Database (Denmark)

    Horstmann, Peter Frederik; Raina, Deepak Bushan; Isaksson, Hanna

    2017-01-01

    /hydroxyapatite biomaterial (GBM) could serve as a carrier for local delivery of bone morphogenic protein-2 (BMP-2) and zoledronic acid (ZA) in a tibia defect model in rats. Empty and allograft-filled defects were used as controls. A 3 × 4-mm metaphyseal bone defect was created in the proximal tibia, and the rats were...

  8. Computational mask defect review for contamination and haze inspections

    Science.gov (United States)

    Morgan, Paul; Rost, Daniel; Price, Daniel; Corcoran, Noel; Satake, Masaki; Hu, Peter; Peng, Danping; Yonenaga, Dean; Tolani, Vikram; Wolf, Yulian; Shah, Pinkesh

    2013-09-01

    the mask manufacturing process. The latter characterization qualifies real defect signatures, such as pin-dots or pin-holes, extrusions or intrusions, assist-feature or dummy-fill defects, writeerrors or un-repairable defects, chrome-on-shifter or missing chrome-from-shifter defects, particles, etc., and also false defect signatures, such as those due to inspection tool registration or image alignment, interlace artifacts, CCD camera artifacts, optical shimmer, focus errors, etc. Such qualitative characterization of defects has enabled better inspection tool SPC and process defect control in the mask shop. In this paper, the same computational approach to defect review has been extended to contamination style defect inspections, including Die-to-Die reflected, and non Die-to-Die or single-die inspections. In addition to the computational methods used for transmitted aerial images, defects detected in die-to-die reflected light mode are analyzed based on special defect and background coloring in reflected-light, and other characteristics to determine the exact type and severity. For those detected in the non Die-to-Die mode, only defect images are available from the inspection tool. Without a reference, i.e., defect-free image, it is often difficult to determine the true nature or impact of the defect in question. Using a combination of inspection-tool modeling and image inversion techniques, Luminescent's LAIPHTM system generates an accurate reference image, and then proceeds with automated defect characterization as if the images were simply from a die-to-die inspection. The disposition of contamination style defects this way, filters out >90% of false and nuisance defects that otherwise would have been manually reviewed or measured on AIMSTM. Such computational defect review, unifying defect disposition across all available inspection modes, has been imperative to ensuring no yield losses due to errors in operator defect classification on one hand, and on the other

  9. 3D-Printed Atsttrin-Incorporated Alginate/Hydroxyapatite Scaffold Promotes Bone Defect Regeneration with TNF/TNFR Signaling Involvement.

    Science.gov (United States)

    Wang, Quan; Xia, Qingqing; Wu, Yan; Zhang, Xiaolei; Wen, Feiqiu; Chen, Xiaowen; Zhang, Shufang; Heng, Boon Chin; He, Yong; Ouyang, Hong-Wei

    2015-08-05

    High expression levels of pro-inflammatory tumor necrosis factor (TNF)-α within bone defects can decelerate and impair bone regeneration. However, there are few available bone scaffolds with anti-inflammatory function. The progranulin (PGRN)-derived engineered protein, Atsttrin, is known to exert antagonistic effects on the TNF-α function. Hence, this study investigates whether 3D-printed Atsttrin-incorporated alginate(Alg)/hydroxyapatite(nHAp) scaffolds can facilitate bone healing through affecting the TNF/TNFR signaling. A 3D bioprinting system is used to fabricate Atsttrin-Alg/nHAp composite scaffolds, and the Atsttrin release from this scaffold is characterized, followed by evaluation of its efficacy on bone regeneration both in vitro and in vivo. The 3D-printed Atsttrin-Alg/nHAp scaffold exhibits a precisely defined structure, can sustain Atsttrin release for at least 5 days, has negligible cytotoxicity, and supports cell adhesion. Atsttrin can also attenuate the suppressive effects of TNF-α on BMP-2-induced osteoblastic differentiation in vitro. The 3D-printed Atsttrin-Alg/nHAp scaffold significantly reduces the number of TNF-α positive cells within wound sites, 7 days after post-calvarial defect surgery. Additionally, histological staining and X-ray scanning results also show that the 3D-printed Atsttrin-Alg/nHAp scaffold enhances the regeneration of mice calvarial bone defects. These findings thus demonstrate that the precise structure and anti-inflammatory properties of 3D-printed Atsttrin-Alg/nHAp scaffolds may promote bone defect repair. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Defects in semiconductors

    CERN Document Server

    Romano, Lucia; Jagadish, Chennupati

    2015-01-01

    This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

  11. Phononic crystals with one-dimensional defect as sensor materials

    Science.gov (United States)

    Aly, Arafa H.; Mehaney, Ahmed

    2017-09-01

    Recently, sensor technology has attracted great attention in many fields due to its importance in many engineering applications. In the present work, we introduce a study using the innovative properties of phononic crystals in enhancing a new type of sensors based on the intensity of transmitted frequencies inside the phononic band gaps. Based on the transfer matrix method and Bloch theory, the expressions of the reflection coefficient and dispersion relation are presented. Firstly, the influences of filling fraction ratio and the angle of incidence on the band gap width are discussed. Secondly, the localization of waves inside band gaps is discussed by enhancing the properties of the defected phononic crystal. Compared to the periodic structure, localization modes involved within the band structure of phononic crystals with one and two defect layers are presented and compared. Trapped localized modes can be detected easily and provide more information about defected structures. Such method could increase the knowledge of manufacturing defects by measuring the intensity of propagated waves in the resonant cavities and waveguides. Moreover, several factors enhance the role of the defect layer on the transmission properties of defected phononic crystals are presented. The acoustic band gap can be used to detect or sense the type of liquids filling the defect layer. The liquids make specific resonant modes through the phononic band gaps that related to the properties of each liquid. The frequency where the maximum resonant modes occur is correlated to material properties and allows to determine several parameters such as the type of an unknown material.

  12. Electronic structure of point defects in semiconductors

    International Nuclear Information System (INIS)

    Bruneval, Fabien

    2014-01-01

    This 'Habilitation a diriger des Recherches' memoir presents most of my scientific activities during the past 7 years, in the field of electronic structure calculations of defects in solids. Point defects (vacancies, interstitials, impurities) in functional materials are a key parameter to determine if these materials will actually fill the role they have been assigned or not. Indeed, the presence of defects cannot be avoided when the temperature is increased or when the material is subjected to external stresses, such as irradiation in the nuclear reactors and in artificial satellites with solar radiations. However, in many cases, defects are introduced in the materials on purpose to tune the electronic transport, optical or even magnetic properties. This procedure is called the doping of semiconductors, which is the foundation technique for transistors, diodes, or photovoltaic cells. However, doping is not always straightforward and unexpected features may occur, such as doping asymmetry or Fermi level pinning, which can only be explained by complex phenomena involving different types of defects or complexes of defects. In this context, the calculations of electronic structure ab initio is an ideal tool to complement the experimental observations, to gain the understanding of phenomena at the atomic level, and even to predict the properties of defects. The power of the ab initio calculations comes from their ability to describe any system of electrons and nuclei without any specific adjustment. But although there is a strong need for numerical simulations in this field, the ab initio calculations for defects are still under development as of today. The work presented in this memoir summarizes my contributions to methodological developments on this subject. These developments have followed two main tracks. The first topic is the better understanding of the unavoidable finite size effects. Indeed, defects in semiconductors or insulators are generally present in

  13. Charge balancing fill rate monitor

    International Nuclear Information System (INIS)

    Rothman, J.L.; Blum, E.B.

    1995-01-01

    A fill rate monitor has been developed for the NSLS storage rings to allow machine tuning over a very large dynamic range of beam current. Synchrotron light, focused on a photodiode, produces a signal proportional to the beam current. A charge balancing circuit processes the diode current, creating an output signal proportional to the current injected into the ring. The unit operates linearly over a dynamic range of 120 dB and can resolve pulses of injected beam as small as 1 μA

  14. Rice Husk Filled Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Arjmandi

    2015-01-01

    Full Text Available Natural fibers from agricultural wastes are finding their importance in the polymer industry due to the many advantages such as their light weight, low cost and being environmentally friendly. Rice husk (RH is a natural sheath that forms around rice grains during their growth. As a type of natural fiber obtained from agroindustrial waste, RH can be used as filler in composites materials in various polymer matrices. This review paper is aimed at highlighting previous works of RH filled polymer composites to provide information for applications and further research in this area. Based on the information gathered, application of RH filled composites as alternative materials in building and construction is highly plausible with both light weight and low cost being their main driving forces. However, further investigations on physical and chemical treatment to further improve the interfacial adhesion with polymeric matrix are needed as fiber-polymer interaction is crucial in determining the final composite properties. Better understanding on how the used polymer blends as the matrix and secondary fillers may affect the properties would provide interesting areas to be explored.

  15. Domain walls and spacetime-filling branes

    NARCIS (Netherlands)

    Bergshoeff, E; Wess, J; Ivanov, EA

    1999-01-01

    We discuss branes with one transversal direction (domain walls) and no transversal direction (spacetime-filling branes). In particular, we briefly discuss a relationship between spacetime-filling branes and superstring theories with sixteen supercharges.

  16. Vertical Scan-Conversion for Filling Purposes

    OpenAIRE

    Hersch, R. D.

    1988-01-01

    Conventional scan-conversion algorithms were developed independently of filling algorithms. They cause many problems, when used for filling purposes. However, today's raster printers and plotters require extended use of filling, especially for the generation of typographic characters and graphic line art. A new scan-conversion algorithm, called vertical scan-conversion has been specifically designed to meet the requirements of parity scan line fill algorithms. Vertical scan-conversion ensures...

  17. Defects in hardwood timber

    Science.gov (United States)

    Roswell D. Carpenter; David L. Sonderman; Everette D. Rast; Martin J. Jones

    1989-01-01

    Includes detailed information on all common defects that may aRect hardwood trees and logs. Relationships between manufactured products and those forms of round material to be processed from the tree for conversion into marketable products are discussed. This handbook supersedes Agriculture Handbook No. 244, Grade defects in hardwood timber and logs, by C.R. Lockard, J...

  18. Craniotomy Frontal Bone Defect

    African Journals Online (AJOL)

    2018-03-01

    Mar 1, 2018 ... with cosmetic deformity of fore head (Figure 1), and he claimed that he could not get job because of ... 1: Pre-operative forontal view of patient. Figure 2: Intra operative photography of defect (A) reconstructed defect (B) ... with a cosmetic deformity of forehead on left side. (4nA and B). He was a candidate for.

  19. 21 CFR 1305.15 - Unaccepted and defective DEA Forms 222.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Unaccepted and defective DEA Forms 222. 1305.15... I AND II CONTROLLED SUBSTANCES DEA Form 222 § 1305.15 Unaccepted and defective DEA Forms 222. (a) A DEA Form 222 must not be filled if either of the following apply: (1) The order is not complete...

  20. Unicortical critical size defect of rabbit tibia is larger than 8 mm

    DEFF Research Database (Denmark)

    Aaboe, M; Pinholt, E M; Hjørting-Hansen, E

    1994-01-01

    The critical-size defect is important as an experimental model to test bone repair materials. Guided tissue regeneration is an established method for tissue regeneration within periodontal surgery. Bony defects covered by a membrane are allowed to be filled by bony tissue. Healing of 8-mm...

  1. 7 CFR 58.923 - Filling containers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Filling containers. 58.923 Section 58.923 Agriculture... Procedures § 58.923 Filling containers. (a) The filling of small containers with product shall be done in a sanitary manner. The containers shall not contaminate or detract from the quality of the product in any way...

  2. Defects at oxide surfaces

    CERN Document Server

    Thornton, Geoff

    2015-01-01

    This book presents the basics and characterization of defects at oxide surfaces. It provides a state-of-the-art review of the field, containing information to the various types of surface defects, describes analytical methods to study defects, their chemical activity and the catalytic reactivity of oxides. Numerical simulations of defective structures complete the picture developed. Defects on planar surfaces form the focus of much of the book, although the investigation of powder samples also form an important part. The experimental study of planar surfaces opens the possibility of applying the large armoury of techniques that have been developed over the last half-century to study surfaces in ultra-high vacuum. This enables the acquisition of atomic level data under well-controlled conditions, providing a stringent test of theoretical methods. The latter can then be more reliably applied to systems such as nanoparticles for which accurate methods of characterization of structure and electronic properties ha...

  3. Turbine superalloy component defect repair with low-temperature curing resin

    Science.gov (United States)

    Hunt, David W.; Allen, David B.

    2015-09-08

    Voids, cracks or other similar defects in substrates of thermal barrier coated superalloy components, such as turbine blades or vanes, are filled with resin, without need to remove substrate material surrounding the void by grinding or other processes. The resin is cured at a temperature under 200.degree. C., eliminating the need for post void-filling heat treatment. The void-filled substrate and resin are then coated with a thermal barrier coating.

  4. Possible mechanism for d0 ferromagnetism mediated by intrinsic defects

    KAUST Repository

    Zhang, Zhenkui

    2014-01-01

    We examine the effects of several intrinsic defects on the magnetic behavior of ZnS nanostructures using hybrid density functional theory to gain insights into d0 ferromagnetism. Previous studies have predicted that the magnetism is due to a coupling between partially filled defect states. By taking into account the electronic correlations, we find an additional splitting of the defect states in Zn vacancies and thus the possibility of gaining energy by preferential filling of hole states, establishing ferromagnetism between spin polarized S 3p holes. We demonstrate a crucial role of neutral S vacancies in promoting ferromagnetism between positively charged S vacancies. S dangling bonds on the nanoparticle surface also induce ferromagnetism. This journal is

  5. Evaluating the Effect of Dental Filling Material and Filling Depth on the Strength and Deformation of Filled Teeth

    Directory of Open Access Journals (Sweden)

    Seifollah Gholampour

    2016-10-01

    Full Text Available ackground and aim: It is important to evaluate the effect of the type of filling material on deformation and strength of tooth after filling and also the effect of filling depth on quality of restoration of a decayed tooth. Material and Methods: The Orthopantomogram (OPG of the first and second molars of a 28-year-old man was made and the teeth were 3D modeled. The stress-deformation analysis was then performed on the models in the three states of normal tooth, tooth filled with amalgam and tooth filled with composite using finite element method under a distributed load of 400N equivalent to chewing force. Two values (1/2 and 1/3 of the tooth height were considered for filling depth in the analyses. Results: The results showed that the normal first molar was exposed to a 7.2% greater risk of dental injuries compared to the normal second molar and also a greater stress is created in it when it is filled with composite. The first molar filled with a composite material is 13.7% weaker than the normal tooth while it is almost as strong as a normal tooth when it is filled with amalgam. The effect of the type of filling material on the strength and deformation of the second molar was trivial. Conclusion: Amalgam is a more proper dental filling material for the first molar although a 16.7% change in drilling depth is needed for tooth preparation. Dental filling material and filling depth have a small effect on the strength and deformation of filled second molars.

  6. Screening Tests for Birth Defects

    Science.gov (United States)

    ... Advocacy For Patients About ACOG Screening Tests for Birth Defects Home For Patients Search FAQs Screening Tests ... FAQ165, April 2014 PDF Format Screening Tests for Birth Defects Pregnancy What is a birth defect? What ...

  7. Single Ventricle Defects

    Science.gov (United States)

    ... heart defects along with pulmonary atresia. (Children with tetralogy of Fallot who also have pulmonary atresia may have treatment similar to others with tetralogy of Fallot.) How does it affect the heart? An opening ...

  8. Repairing Nanoparticle Surface Defects

    NARCIS (Netherlands)

    Marino, Emanuele; Kodger, Thomas E.; Crisp, R.W.; Timmerman, Dolf; MacArthur, Katherine E.; Heggen, Marc; Schall, Peter

    2017-01-01

    Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We

  9. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  10. Mathematical modeling of the process of filling a mold during injection molding of ceramic products

    Science.gov (United States)

    Kulkov, S. N.; Korobenkov, M. V.; Bragin, N. A.

    2015-10-01

    Using the software package Fluent it have been predicted of the filling of a mold in injection molding of ceramic products is of great importance, because the strength of the final product is directly related to the presence of voids in the molding, making possible early prediction of inaccuracies in the mold prior to manufacturing. The calculations were performed in the formulation of mathematical modeling of hydrodynamic turbulent process of filling a predetermined volume of a viscous liquid. The model used to determine the filling forms evaluated the influence of density and viscosity of the feedstock, and the injection pressure on the mold filling process to predict the formation of voids in the area caused by the shape defect geometry.

  11. Operation feedback of hydrogen filling station

    International Nuclear Information System (INIS)

    Pregassame, S.; Barral, K.; Allidieres, L.; Charbonneau, T.; Lacombe, Y.

    2004-01-01

    One of the technical challenges of hydrogen technology is the development of hydrogen infrastructures which satisfy either safety requirements and reliability of filling processes. AIR LIQUIDE realized an hydrogen filling station in Sassenage (France) operational since September 2003. This station is able to fill 3 buses a day up to 350bar by equilibrium with high pressure buffers. In parallel with commercial stations, the group wanted to create a testing ground in real conditions running with several objectives: validate on a full scale bench a simulation tool able to predict the temperature of both gas and cylinder's materials during filling processes; define the best filling procedures in order to reach mass, temperature and filling time targets; analyse the temperature distribution and evolution inside the cylinder; get a general knowledge about hydrogen stations from safety and reliability point of view; operate the first full scale refuelling station in France. The station is also up-graded for 700bar filling from either a liquid hydrogen source or a gas booster, with cold filling possibility. This paper presents the results concerning 350bar filling : thermal effects, optimal filling procedures and influence of parameters such as climatic conditions are discussed. (author)

  12. Dedicated composite fillings − inlays

    Directory of Open Access Journals (Sweden)

    Šaulić Slobodan

    2003-01-01

    Full Text Available Background. The aim of the study was to evaluate the quality and persistance of esthetics of dedicated inlay by clinical methods. Methods. The paper reviews the clinical significance and technique of preparing particular composite inlays before and after the construction of the metallic framework partial denture. On the basis of indications the total of 30 inlays were placed into cavities under relatively dry working conditions. Six, twelve eighteen and twenty-four months after the placement of filling, control check-up was carried out by Ryge criteria. Results. After two years marginal discoloration as well as the change of the colour occured in 3.3% of inlays. There was neither detectable secondary caries, nor the symtoms of pulpal damage. The requirements to be fulfilled concerning the composite materials in order that they can be implemented for this purpose, were also discussed. Conclusion. From the clinical point of view, purpouse inlays from Herculite XRV lab C8B in combination with Opti Bond System and composite cement Porcelite Dual Cure showed high functional and esthetic values in the observational period of two years.

  13. Mekong Floods Fill Tonle Sap

    Science.gov (United States)

    2002-01-01

    The monsoon season in Southeast Asia brings recurring, often devastating floods to countries in the region, but these floods also play a necessary role in the region's water cycle. These MODIS images centered on Cambodia reveal extensive flooding of the Mekong River, which comes in from Laos in the north, to the right of center in the images, and flows south through Cambodia and southeast through Vietnam to empty into the South China Sea. The true-color image shows the brownish, sediment-laden floodwaters filling the Mekong Delta in southern Cambodia and Vietnam on September 15, 2001. The false color image above has been enhanced to bring out the contrast between the floodwaters and the lands, with sediment-carrying floodwaters in purple. Sediment can be seen flowing into the South China Sea as well. This year's floods have affected over a million people, and 100 people have been killed in Vietnam alone. The monsoon floods bring not only devastation, but renewal. The large body of water just left of center in Cambodia is the Tonle Sap. This shallow lake plays a changing role in the regional water cycle. During the dry season, the stream-fed Tonle Sap drains via the Tonle Sab River into the Mekong River. During the wet season (June-November), flooding of the Mekong reverses the course of the Tonle Sab, roughly tripling the lake's size from about 3000 km2 to about 10,000. When the dry season returns, the lake once again begins to drain into the Mekong Delta, where it provides a flow of fresh water that balances the intrusion of salty seawater into the delta's agricultural lands. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  14. Comparison of Guided Bone Regeneration Between Surface-Modified and Pristine Titanium Membranes in a Rat Calvarial Model.

    Science.gov (United States)

    Nguyen, Thuy-Duong; Moon, So-Hee; Oh, Tae-Ju; Seok, Jung-Jin; Lee, Min-Ho; Bae, Tae-Sung

    2016-01-01

    The objectives of this study were to evaluate bioactivity of a titanium membrane with anodization, cyclic precalcification, and heat (APH) treatment (APHTM), and to compare APHTM and nontreated titanium membrane (NTTM) in guided bone regeneration using histologic analysis and microcomputed tomography (micro-CT). APHTM samples were prepared and immersed in simulated body fluid for 2 days, then observed using field-emission scanning electron microscopy, followed by an analysis of calcium and phosphate precipitation using an energy dispersive x-ray spectroscopy. For the in vivo experiment, critical-size defects were created in rat calvaria (diameter, 8 mm) and treated with either APHTM or NTTM (n = 14 each). Biopsies were performed at 2 and 4 weeks for histologic analysis (n = 3 per group each time). Fluorochrome bone markers were injected in three rats in each group at 3 (alizarin red) and 5 weeks (calcein green), followed by histologic examination at 7 weeks. Micro-CT was performed at 8 weeks (n = 5 per group). APHTM exhibited high bioactivity, characterized by dense nano-sized flakelike crystals throughout the membrane and an increase in the calcium-phosphate concentrations after 2-day immersion in simulated body fluid. At 2 and 4 weeks, APHTM samples showed an intimate bone formation onto the membrane, whereas NTTM samples demonstrated interposition of connective tissue between the membrane and newly formed bone. The same pattern was found in the fluorescent study. The micro-CT analysis revealed significantly lower bone volume but higher bone mineral density in the APHTM samples than in the NTTM samples (P bone formation toward the membrane, thus increasing structural durability for bone regeneration. Further research is warranted to confirm the results found in these in vitro and in vivo experiments.

  15. Selective COX-2 inhibitor reduces bone healing in bone defects Inibidor seletivo de COX-2 reduz reparo em defeitos ósseos

    Directory of Open Access Journals (Sweden)

    Bruno César de Vasconcelos Gurgel

    2005-12-01

    Full Text Available Anti-inflammatory agents have been reported to regulate bone healing. The aim of this study was to investigate the effect of a selective cyclooxygenase-2 inhibitor (meloxicam on bone healing in calvarial defects in rats. Thirty-six adult male Wistar rats were included. After anesthesia, a linear incision was made through the skin of the scalp, a full-thickness flap was reflected and a 4 mm round defect was made with a trephine drill. The animals were randomly assigned to one of the following 4 treatment groups (9 animals each, including daily subcutaneous injections: A: saline solution for 15 days; B: saline solution for 45 days; C: 3 mg/kg of meloxicam for 15 days and D: 3 mg/kg of meloxicam for 45 days. The animals were sacrificed and the specimens, routinely processed. The bone filling was histometrically measured and statistical analysis, performed. Intergroup comparisons demonstrated that the meloxicam groups presented a significant reduction in bone healing when compared to their respective controls (group A, 44.5 ± 5.75%, against group C, 57.5 ± 7.25%, p Agentes antiinflamatórios têm sido descritos como reguladores do reparo ósseo. O objetivo deste estudo foi investigar o efeito de um inibidor seletivo da cicloxigenase-2 (meloxicam no reparo ósseo em defeitos de calvárias de ratos. Trinta e seis ratos machos Wistar foram incluídos no estudo. Após anestesia, incisão linear e rebatimento de retalho de espessura total, um defeito de 4 mm de diâmetro foi criado na calvária dos animais com broca trefina. Os mesmos foram aleatoriamente distribuídos em um dos 4 grupos de tratamento (9 animais por grupo, recebendo injeções subcutâneas diárias de: A: soro fisiológico por 15 dias; B: soro fisiológico por 45 dias; C: 3 mg/kg de meloxicam por 15 dias; D: 3 mg/kg de meloxicam por 45 dias. Os animais foram sacrificados e os espécimes rotineiramente processados. Medidas do preenchimento ósseo foram histometricamente realizadas e

  16. A single intraperitoneal injection of bovine fetuin-A attenuates bone resorption in a murine calvarial model of particle-induced osteolysis.

    Science.gov (United States)

    Jablonski, Heidrun; Polan, Christina; Wedemeyer, Christian; Hilken, Gero; Schlepper, Rüdiger; Bachmann, Hagen Sjard; Grabellus, Florian; Dudda, Marcel; Jäger, Marcus; Kauther, Max Daniel

    2017-12-01

    Particle-induced osteolysis, which by definition is an aseptic inflammatory reaction to implant-derived wear debris eventually leading to local bone destruction, remains the major reason for long-term failure of orthopedic endoprostheses. Fetuin-A, a 66kDa glycoprotein with diverse functions, is found to be enriched in bone. Besides being an important inhibitor of ectopic calcification, it has been described to influence the production of mediators of inflammation. Furthermore, a regulatory role in bone metabolism has been assigned. In the present study, the influence of a single dose of bovine fetuin-A, intraperitoneally injected in mice subjected to particle-induced osteolysis of the calvaria, was analyzed. Twenty-eight male C57BL/6 mice, twelve weeks of age, were randomly divided into four groups. Groups 2 and 4 were subjected to ultra-high molecular weight polyethylene (UHMWPE) particles placed on their calvariae while groups 1 and 3 were sham-operated. Furthermore, groups 3 and 4 received a single intraperitoneal injection of 20mg bovine fetuin-A while groups 1 and 2 were treated with physiologic saline. After 14days calvarial bone was qualitatively and quantitatively assessed using microcomputed tomography (μCT) and histomorphometrical approaches. Application of fetuin-A led to a reduction of particle-induced osteolysis in terms of visible osteolytic lesions and eroded bone surface. The reduction of bone thickness and bone volume, as elicited by UHMWPE, was alleviated by fetuin-A. In conclusion, fetuin-A was found to exert an anti-resorptive effect on particle-induced osteolysis in-vivo. Thus, fetuin-A could play a potentially osteoprotective role in the treatment of bone metabolic disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Long-term results of secondary alveolar bone grafting using a technique to harvest pure calvarial cancellous bone: Evaluation based on plain radiography and computed tomography.

    Science.gov (United States)

    Han, Kihwan; Jeong, Woonhyeok; Yeo, Hyeonjung; Choi, Jaehoon; Kim, Junhyung; Son, Daegu; Oh, Sangho; Kim, Changhyun

    2017-03-01

    We introduce a method to extract the maximum amount of cancellous bone from the calvarium and analyze the outcomes using plain radiography and computed tomography. We retrospectively analyzed the medical records of patients who underwent secondary alveolar bone grafts using a maximal harvesting technique for calvarial cancellous bone. Bone survival was determined based on Enemark's grading system using plain radiographs. Alveolar thickness and height were analyzed by computed tomography and compared with radiographic measurements. Our study enrolled 27 patients, 22 unilateral and 5 bilateral, for a total of 32 alveolar clefts. The mean age at surgery was 9.04 ± 0.41 years (range: 6-12 years). Donor sites were successfully recovered without complications, such as hematomas, seromas, infections, or tears in the dura mater. The mean follow-up duration for obtaining plain radiographs was 6.90 ± 0.61 years (range: 2.0-18.50 years). The mean follow-up duration for computed tomography was 6.51 ± 0.99 years (range: 2.0-14.83 years). A canine tooth erupted in 30 cases. Success (Enemark's grades I or II) was achieved in 26 cases. Alveolar height was strongly correlated with the Enemark scale results (γ = 0.878, p technique resulted in successful graft survival without serious complications, including dural or brain injuries. Although the ilium is widely accepted as the optimal donor site for secondary alveolar bone grafting, the calvarium could be an alternative donor site that results in equivalent outcomes. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. 7 CFR 58.730 - Filling containers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Filling containers. 58.730 Section 58.730 Agriculture... Procedures § 58.730 Filling containers. Hot fluid cheese from the cookers may be held in hotwells or hoppers... shall effectively measure the desired amount of product into the pouch or container in a sanitary manner...

  19. Quantum computing with defects

    Science.gov (United States)

    Varley, Joel

    2011-03-01

    The development of a quantum computer is contingent upon the identification and design of systems for use as qubits, the basic units of quantum information. One of the most promising candidates consists of a defect in diamond known as the nitrogen-vacancy (NV-1) center, since it is an individually-addressable quantum system that can be initialized, manipulated, and measured with high fidelity at room temperature. While the success of the NV-1 stems from its nature as a localized ``deep-center'' point defect, no systematic effort has been made to identify other defects that might behave in a similar way. We provide guidelines for identifying other defect centers with similar properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate systems. To elucidate these points, we compare electronic structure calculations of the NV-1 center in diamond with those of several deep centers in 4H silicon carbide (SiC). Using hybrid functionals, we report formation energies, configuration-coordinate diagrams, and defect-level diagrams to compare and contrast the properties of these defects. We find that the NC VSi - 1 center in SiC, a structural analog of the NV-1 center in diamond, may be a suitable center with very different optical transition energies. We also discuss how the proposed criteria can be translated into guidelines to discover NV analogs in other tetrahedrally coordinated materials. This work was performed in collaboration with J. R. Weber, W. F. Koehl, B. B. Buckley, A. Janotti, C. G. Van de Walle, and D. D. Awschalom. This work was supported by ARO, AFOSR, and NSF.

  20. Structure defects in cementite

    International Nuclear Information System (INIS)

    Schmitt, Bernard

    1971-01-01

    After a presentation of experimental techniques (elaboration principles, elaboration techniques, and investigation techniques for cementite thin layers and iron-carbon massive alloys), the author of this research thesis reports the study of cementite structure (interatomic distance, description and representation), reports the study of iron-carbon thin layers (structure, influence of silicon, defects), reports the study of perfect and imperfect dislocations and of plane defects in cementite. The author also reports hardness measurements, and discusses the relationships between cementite and other iron carbides

  1. Influence of defects on diamond detection properties

    International Nuclear Information System (INIS)

    Tromson, Dominique

    2000-01-01

    This work focuses on the study of the influence of defects on the detection properties of diamond. Devices are fabricated using natural as well as synthetic diamond samples grown using the plasma enhanced chemical vapour deposition (CVD). Optical studies with infrared and Raman spectrometry are used to characterise the material properties as well as thermoluminescence and thermally stimulated current measurements. These thermally stimulated analyses reveal the presence of several trapping levels with emission temperatures below or near room temperature as well as an important level near 550 K. The influence of these defects on the alpha and X-ray detector responses is studied as a function of the initial state of the detectors (thermal treatment, irradiation) and of the measurement conditions (time, temperature). The results show a significant correlation between the charged state of traps, namely filled or empty and the response of the detectors. It appears that filling and emptying the traps respectively enhances the sensitivity and stability of detection devices to be used at room temperature and decreases the detection properties at higher temperature. Localised measurements are also used to study the spatial inhomogeneity of natural and CVD diamond samples from the 2D mapping of the detector responses. Non uniformity are attributed to a non-isotropic distribution of defects in natural diamonds. By comparing the detector responses to the topographical map of CVD samples a correlation appears between grains and grain boundaries with the variation of the detector sensitivity. Devices fabricated for detection applications with CVD samples are presented and namely for the monitoring and profiling of synchrotron beams as well as dose rate measurements in harsh environments. (author) [fr

  2. Defect-induced mix experiment for NIF

    Directory of Open Access Journals (Sweden)

    Schmitt M.J.

    2013-11-01

    Full Text Available The Defect Induced Mix Experiment (DIME-II will measure the implosion and mix characteristics of CH capsules filled with 5 atmospheres of DT by incorporating mid-Z dopant layers of Ge and Ga. This polar direct drive (PDD experiment also will demonstrate the filling of a CH capsule at target chamber center using a fill tube. Diagnostics for these experiments include areal x-ray backlighting to obtain early time images of the implosion trajectory and a multiple-monochromatic imager (MMI to collect spectrally-resolved images of the capsule dopant line emission near bangtime. The inclusion of two (or more thin dopant layers at separate depths within the capsule shell facilitates spatial correlation of mix between the layers and the hot gas core on a single shot. The dopant layers are typically 2 μm thick and contain dopant concentrations of 1.5%. Three dimensional Hydra simulations have been performed to assess the effects of PDD asymmetry on capsule performance.

  3. The effect of reciprocation versus rotational movement on the incidence of root defects during retreatment procedures.

    Science.gov (United States)

    Üstün, Y; Topçuoğlu, H S; Düzgün, S; Kesim, B

    2015-10-01

    To compare the incidence of dentinal defects caused by reciprocating and rotary techniques during retreatment procedures. One hundred and twenty extracted mandibular premolars with single canals were selected. Twenty teeth were left unprepared. The root canals in the remaining 100 teeth were prepared with K-files up to size 35 and filled with Gutta-percha and AH Plus sealer using a passive cold lateral compaction technique. Twenty canals were filled and received no further treatment. Eighty teeth were divided into four groups (n = 20 in each) to undergo the removal of the root filling. In groups 1 and 2, the root filling was removed using ProTaper Retreatment files and Reciproc files, respectively, and the canals were not refilled. In groups 3 and 4, the root filling was removed using ProTaper Retreatment files and Reciproc files, respectively, and the canals were then refilled using a conventional cold lateral compaction technique. The roots were sectioned horizontally at 3, 6 and 9 mm from the root apex and observed under a stereomicroscope at 20× magnification. Defects were categorized as no defect, incomplete defect and fracture. The differences between the groups were analysed using the chi-square exact test (P = 0.05). No defects were observed in the unprepared and filled groups, in contrast to the experimental groups. In the coronal thirds, groups 2 and 4 had more dentinal defects than groups 1 and 3 (P 0.05). Both nickel-titanium systems were associated with dentinal defects during retreatment procedures in extracted premolar teeth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  4. Quantum computing with defects.

    Science.gov (United States)

    Weber, J R; Koehl, W F; Varley, J B; Janotti, A; Buckley, B B; Van de Walle, C G; Awschalom, D D

    2010-05-11

    Identifying and designing physical systems for use as qubits, the basic units of quantum information, are critical steps in the development of a quantum computer. Among the possibilities in the solid state, a defect in diamond known as the nitrogen-vacancy (NV(-1)) center stands out for its robustness--its quantum state can be initialized, manipulated, and measured with high fidelity at room temperature. Here we describe how to systematically identify other deep center defects with similar quantum-mechanical properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate defect systems. To illustrate these points in detail, we compare electronic structure calculations of the NV(-1) center in diamond with those of several deep centers in 4H silicon carbide (SiC). We then discuss the proposed criteria for similar defects in other tetrahedrally coordinated semiconductors.

  5. Defects in semiconductor nanostructures

    Indian Academy of Sciences (India)

    sizes were less than 100 Si atoms due to computational limitations. An interesting parallel is that current first principles calculations alluded to in §5 are size ham- pered for similar reasons. These 'defect molecule' calculations were probably the first studies in SN. We believe that a perusal of this 'ancient' scientific literature.

  6. Production of point defects

    International Nuclear Information System (INIS)

    Zuppiroli, L.

    1975-01-01

    Vacancies at thermodynamic equilibrium and the annealing of these defects are studied first, after which electron irradiations are dealt with. The displacement threshold energy concept is introduced. Part three concerns heavy ion and neutron irradiations. Displacement cascades and the thermal spike concept are discussed [fr

  7. Fetal abdominal wall defects.

    Science.gov (United States)

    Prefumo, Federico; Izzi, Claudia

    2014-04-01

    The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Defects in flexoelectric solids

    Science.gov (United States)

    Mao, Sheng; Purohit, Prashant K.

    2015-11-01

    A solid is said to be flexoelectric when it polarizes in proportion to strain gradients. Since strain gradients are large near defects, we expect the flexoelectric effect to be prominent there and decay away at distances much larger than a flexoelectric length scale. Here, we quantify this expectation by computing displacement, stress and polarization fields near defects in flexoelectric solids. For point defects we recover some well known results from strain gradient elasticity and non-local piezoelectric theories, but with different length scales in the final expressions. For edge dislocations we show that the electric potential is a maximum in the vicinity of the dislocation core. We also estimate the polarized line charge density of an edge dislocation in an isotropic flexoelectric solid which is in agreement with some measurements in ice. We perform an asymptotic analysis of the crack tip fields in flexoelectric solids and show that our results share some features from solutions in strain gradient elasticity and piezoelectricity. We also compute the energy release rate for cracks using simple crack face boundary conditions and use them in classical criteria for crack growth to make predictions. Our analysis can serve as a starting point for more sophisticated analytic and computational treatments of defects in flexoelectric solids which are gaining increasing prominence in the field of nanoscience and nanotechnology.

  9. Semiconductor Nanowires: Defects Update

    Science.gov (United States)

    Kavanagh, Karen L.

    2008-05-01

    Structural defects commonly observed in semiconducting nanowires by electron microscopy will be reviewed and their origins discussed. Their effects on electrical and optical properties will be illustrated with examples from GaSb, InAs, and ZnSe nanowires grown by MOCVD and MBE.

  10. Solubility of Hydrogen and Nitrogen in liquid cast iron during melting and mold filling

    OpenAIRE

    Diószegi, Attila; Elfsberg, Jessica; Diószegi, Zoltán

    2016-01-01

    Defect formation like gas- and shrinkage porosity at cast iron component production is related to the content of gaseous elements in the liquid metal. The present work investigate the solubility of hydrogen and nitrogen in liquid iron aimed for production of lamellar and compacted graphite cast iron. The used methods and instruments are a combination of commercial measuring devices and novel experimental assemblies for measuring solubility of hydrogen and nitrogen during melting and mold fill...

  11. Effect of synthetic cell-binding peptide on the healing of cortical segmental bone defects

    International Nuclear Information System (INIS)

    Cakmak, G.; Bolukbasi, S.; Simsek, A.; Senkoylu, A.; Erdem, O.; Yilmaz, G.

    2006-01-01

    To determine the effect of inorganic bone matric/Pepgen P-15 (ABM/P-15) on the healing of a critical sized segmental defect in a rat radius using a radiological and histological grading system. We carried out this study at the Research Laboratories, Gazi University School of Medicine in 2004. Critical sized segmental defects were created in the radius of 36 Wistar rats. Thirteen defects were filled with ABM/P-15 Flow (gel form), 12 defects were filled with ABM/P-15, and 11 defects were used as a control group. The rats were sacrified at the tenth week, and healing of the defects was evaluated radiographically and histologically. The usage of ABM/P-15 and ABM/P-15 Flow were demonstrated to improve healing of segmental bone defects compared with the control group. Statistical evaluation showed that there were significant differences between control sites, and the sites treated with P-15 and P-15 Flow (p=0.011). The highest radiological and histological grades were achieved by P-15. Segmental cortical bone defects may be treated with ABM/P-15 instead of bone allografts, and autografts. According to the radiological and histological parameters measured in this study, the implantation of ABM/P-15 resulted in optimum healing of the segmental cortical bone defects. Pepgen P-15 has a positive effect on bone healing, without any immunogenic features and disease transmission risk. Therefore, ABM/P-15 can also be used for orthopedic surgery. (author)

  12. Droplet Measurement below Single-Layer Grid Fill

    Directory of Open Access Journals (Sweden)

    Vitkovic Pavol

    2016-01-01

    Full Text Available The main part of the heat transfer in a cooling tower is in a fill zone. This one is consist of a cooling fill. For the cooling tower is used a film fill or grid fill or splash fill in the generally. The grid fill has lower heat transfer performance like film fill usually. But their advantage is high resistance to blockage of the fill. The grid fill is consisted with independent layers made from plastic usually. The layers consist of several bars connected to the different shapes. For experiment was used the rhombus shape. The drops diameter was measured above and below the Grid fill.

  13. Retrograde root filling with amalgam and Cavit.

    Science.gov (United States)

    Finne, K; Nord, P G; Persson, G; Lennartsson, B

    1977-04-01

    In a 3-year review of 218 teeth with retrograde root filling with amalgam orCavit, the results obtained with the former proved significantly better than those obtained with the latter. The difference seemed to be due to a better obliteration of the canal by amalgam. The obliterating effect of amalgam probably eliminates the need for revision of incomplete othograde root filling, for example, in cases with a post in the root canal. Irrespective of type of filling materials, the results were less good in cases with marginal bone loss.

  14. Photo-induced current transient spectroscopy of defect clusters in heavily irradiated silicon

    CERN Document Server

    Menichelli, D

    2002-01-01

    We report an experimental study on radiation-induced defects in silicon p sup + n junctions irradiated with 1 MeV neutrons up to a fluence of approx 2x10 sup 1 sup 5 cm sup - sup 2. Heavily irradiated silicon diodes have been studied by means of Photon-Induced Current Transient Spectroscopy (PICTS) technique using a variable filling time. A dominant broad and structured peak has been found in the temperature range 200-300 K. The behavior of this broad peak upon changing the filling time has been analyzed, and it is observed that spectral line-shape broadens toward lower temperature as the filling time is increased. The observed spectra shape modification cannot be explained in terms of isolated point defects being consistent with quasi-continuous distributions of deep levels inside the band gap. We suggest that the investigated broad peak is at least in part, generated by emission from defect clusters.

  15. Sealing And Filling Cracks In Asphalt Pavements

    Science.gov (United States)

    1999-11-01

    The primary objective of the crack treatment experiment was to determine the most effective and economical materials and methods for conducting crack-sealing and crack-filling operations. Secondary objectives included the identification of performanc...

  16. PERVAPORATION USING ADSORBENT-FILLED MEMBRANES

    Science.gov (United States)

    Membranes containing selective fillers, such as zeolites and activated carbon, can improve the separation by pervaporation. Applications of adsorbent-filled membranes in pervaporation have been demonstrated by a number of studies. These applications include removal of organic co...

  17. Ventricular Septal Defect (For Teens)

    Science.gov (United States)

    ... have a heart defect should avoid getting body piercings. Piercing increases the possibility that bacteria can get into ... damage heart valves. If you're considering a piercing and you have a heart defect, talk to ...

  18. Congenital Heart Defects (For Parents)

    Science.gov (United States)

    ... diagnosed until the teen years — or even adulthood. Newborn Screening Newborns in the U.S. are screened at ... Has a Heart Defect Coarctation of the Aorta Arrhythmias Mitral Valve Prolapse Atrial Septal Defect Ventricular Septal ...

  19. Mechanism of gap-filling during postreplication repair of ultraviolet damage in Haemophilus influenzae

    International Nuclear Information System (INIS)

    Small, G.D.

    1975-01-01

    Deoxyribonucleic acid (DNA), pulse labeled after ultraviolet irradiation of excision-defective mutants of Haemophilus influenzae, is of lower single strand molecular weight than that of unirradiated cells but approaches the size of DNA from unirradiated cells upon further incubation in growth medium. This gap-filling process is controlled by the rec-1 gene. Gap-filling occurs normally in a temperature-sensitive DNA synthesis mutant at the restrictive temperature showing that normal semiconservative DNA synthesis is not necessary for gap-filling. To test for recombinational events after irradiation, the DNA synthesized after irradiation was radioactively labeled for a short time in medium containing 5-bromodeoxyuridine followed by incubation for various times in nonradioactive, 5-bromodeoxyuridine-containing medium. The DNA was denatured and analyzed isopycnically. The labeled DNA was initially ''heavy'', but later shifted toward lighter densities. This shift occurred in the temperature-sensitive DNA synthesis mutant at the restrictive temperature and in the recombination-defective mutant rec-2, but was not seen in the rec-1 mutant. The density shift can be interpreted as evidence that rather extensive exchanges occurred between parental DNA and the DNA made after irradiation. These results suggest that such exchanges are important for gap-filling in H. influenzae. (auth)

  20. Iron-Oxide-Filled Carbon Nanotubes

    Science.gov (United States)

    Cava, Carlos Eduardo

    Carbon nanotubes (CNT) are recognized as one of the most important materials in the recent history of nanotechnology. In the last 25 years, intensive studies about this material have led to new ideas for the use of nanomaterials in many technological products. The unique properties presented by this material allow its use in a wide range of applications. Known as a crystalline material, CNTs can, however, interact with many materials in different manners, making it easy to use as a composite. One interesting aspect is the possibility of filling the CNT hollow core with a foreign material, forming a filled CNT. This composite can be achieved in situ using chemical vapor deposition and arc-discharge or after the synthesis, by chemical methods. The technique choice to achieve the filled CNT depends on the material inside the CNT. The resulting material can provide new electrical, optical, and mechanical features due to the synergistic effect between the CNTs themselves and the filling, which can originate new multifunctional materials. Concerning the electrical conductivity and the gas sensing, the possible interaction between the CNT and the filling can modify the electronic structure of the material and, consequently, affect the kind of interaction between the CNT and different gases. Commonly, the filled CNTs are obtained with magnetic materials inside the tube, which are also precursors in their syntheses; this feature brings new possibilities to magnetic devices, such as memories. Among them, iron-oxide-filled carbon nanotubes have been suggested as a technological material for use in magnetic, electrical, and medical applications. Therefore, this kind of nanocomposite material can be useful in the preparation of versatile and durable solid-state sensors, memory devices, with simple manufacturing and in a proper size. In this chapter, an introduction about the production and application of iron-oxide-filled CNTs in its many different forms will be presented.

  1. Damage evolution in a filled epoxy resin

    International Nuclear Information System (INIS)

    Depoorter, Nicolas; Coutellier, Daniel; Muzic, Markus; Berg-Pollack, Antje; Cai Ye; Zimmermann, Andre

    2006-01-01

    A method is proposed for studying damage evolution in a filled epoxy resin submitted to low-cycle fatigue loading. Transmission electron microscopy analysis was performed, which indicates a damage mechanism that corresponds well to the decreasing slope of the stress-strain hysteresis observed in strain-controlled fatigue experiments. Also, the suggested damage model appears to be suitable for the simulation of strain-controlled cyclic tests and fits the damage evolution of the filled epoxy resin fairly well [de

  2. Amorphous Silica: A New Antioxidant Role for Rapid Critical-Sized Bone Defect Healing.

    Science.gov (United States)

    Ilyas, Azhar; Odatsu, Tetsuro; Shah, Ami; Monte, Felipe; Kim, Harry K W; Kramer, Philip; Aswath, Pranesh B; Varanasi, Venu G

    2016-09-01

    Traumatic fractures cause structurally unstable sites due to severe bone loss. Such fractures generate a high yield of reactive oxygen species (ROS) that can lead to oxidative stress. Excessive and prolonged ROS activity impedes osteoblast differentiation and instigates long healing times. Stimulation of antioxidants such as superoxide dismutase (SOD1), are crucial to reduce ROS, stimulate osteogenesis, and strengthen collagen and mineral formation. Yet, no current fixative devices have shown an ability to enhance collagen matrix formation through antioxidant expression. This study reports plasma-enhanced chemical vapor deposition based amorphous silicon oxynitride (Si(ON)x) as a potential new fracture healing biomaterial that adheres well to the implant surface, releases Si(+4) to enhance osteogenesis, and forms a surface hydroxyapatite for collagen mineral attachment. These materials provide a sustained release of Si(+4) in physiological environment for extended times. The dissolution rate partially depends on the film chemistry and can be controlled by varying O/N ratio. The presence of Si(+4) enhances SOD1, which stimulates other osteogenic markers downstream and leads to rapid mineral formation. In vivo testing using a rat critical-sized calvarial defect model shows a more rapid bone-regeneration for these biomaterials as compared to control groups, that implies the clinical significance of the presented biomaterial. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Defects in Quantum Computers.

    Science.gov (United States)

    Gardas, Bartłomiej; Dziarmaga, Jacek; Zurek, Wojciech H; Zwolak, Michael

    2018-03-14

    The shift of interest from general purpose quantum computers to adiabatic quantum computing or quantum annealing calls for a broadly applicable and easy to implement test to assess how quantum or adiabatic is a specific hardware. Here we propose such a test based on an exactly solvable many body system-the quantum Ising chain in transverse field-and implement it on the D-Wave machine. An ideal adiabatic quench of the quantum Ising chain should lead to an ordered broken symmetry ground state with all spins aligned in the same direction. An actual quench can be imperfect due to decoherence, noise, flaws in the implemented Hamiltonian, or simply too fast to be adiabatic. Imperfections result in topological defects: Spins change orientation, kinks punctuating ordered sections of the chain. The number of such defects quantifies the extent by which the quantum computer misses the ground state, and is, therefore, imperfect.

  4. Reconstructions of eyelid defects

    Directory of Open Access Journals (Sweden)

    Nirmala Subramanian

    2011-01-01

    Full Text Available Eyelids are the protective mechanism of the eyes. The upper and lower eyelids have been formed for their specific functions by Nature. The eyelid defects are encountered in congenital anomalies, trauma, and postexcision for neoplasm. The reconstructions should be based on both functional and cosmetic aspects. The knowledge of the basic anatomy of the lids is a must. There are different techniques for reconstructing the upper eyelid, lower eyelid, and medial and lateral canthal areas. Many a times, the defects involve more than one area. For the reconstruction of the lid, the lining should be similar to the conjunctiva, a cover by skin and the middle layer to give firmness and support. It is important to understand the availability of various tissues for reconstruction. One layer should have the vascularity to support the other layer which can be a graft. A proper plan and execution of it is very important.

  5. Amalgam dental fillings and hearing loss.

    Science.gov (United States)

    Rothwell, Janet A; Boyd, Paul J

    2008-12-01

    In this study we investigated the effects of amalgam dental fillings on auditory thresholds. Participants (n=39) were non-smoking women age 40 to 45. Regression and correlation analyses were performed between auditory thresholds, measured from 0.25 to 16 kHz, and the number/surface area of dental fillings, using the ASHA criteria for ototoxic change as a reference for comparison. No significant correlation (p>0.05) was found between composite (non-amalgam) filling or drilling data and auditory thresholds. However, there was a significant positive linear correlation between amalgam filling data and auditory thresholds at 8, 11.2, 12.5, 14, and 16 kHz. The strongest association (r=0.587, n=39, pamalgam filling was associated with a 2.4 dB decline in hearing threshold (95% confidence interval [CI], 1.3-3.5 dB). The results suggest an association between more amalgam fillings and poorer thresholds at higher frequencies, which could contribute to presbyacusis in developed countries. This provides further argument for the use of amalgams to be phased out where suitable alternatives exist.

  6. [Influence of magnification tools on the recognition of simulated preparation and filling errors].

    Science.gov (United States)

    Zaugg, Balthasar; Stassinakis, Alexandros; Hotz, Peter

    2004-01-01

    37 mistakes or filling defects were mounted onto a phantom model. Three groups--each consisting of thirteen dentists--examined the jaws under clinical conditions using either no visual aid, magnifying glasses or a microscope. They were further asked if using magnifying tools had a positive effect on pains such as neck and back pain, headaches or sore eyes. The group using the microscope spent more time on examination and found significantly more defects than their colleagues using magnifying glasses. They also profited more from the ergonomical advantages. The main clinical use for microscopes is in endodontics. The group of dentists using magnifying glasses spent less time on examination but found more defects than their colleagues using no magnification tools at all. The positive effect on neck and back pain was less pronounced than in the group working with microscopes. Magnifying glasses are used in all kinds of clinical work.

  7. Automatic detection of NIL defects using microscopy and image processing

    KAUST Repository

    Pietroy, David

    2013-12-01

    Nanoimprint Lithography (NIL) is a promising technology for low cost and large scale nanostructure fabrication. This technique is based on a contact molding-demolding process, that can produce number of defects such as incomplete filling, negative patterns, sticking. In this paper, microscopic imaging combined to a specific processing algorithm is used to detect numerically defects in printed patterns. Results obtained for 1D and 2D imprinted gratings with different microscopic image magnifications are presented. Results are independent on the device which captures the image (optical, confocal or electron microscope). The use of numerical images allows the possibility to automate the detection and to compute a statistical analysis of defects. This method provides a fast analysis of printed gratings and could be used to monitor the production of such structures. © 2013 Elsevier B.V. All rights reserved.

  8. Healing of experimental femoral defects in rats after implantation of collagen-calcium phosphate biocomposites

    Directory of Open Access Journals (Sweden)

    O. V. Korenkov

    2017-06-01

    Full Text Available The aim of this study was to investigate the healing process of experimental defects of the femoral shaft diaphysis of rats after implantation of osteoplastic material Collapan into its cavity. In experi-mental animals, a perforated defect with diameter of 2.5 mm was created in the medullary canal of the femoral shaft and filled with osteoplastic material Collapan. In control rats, the defect was left un-filled. The bone fragments were examined on the 15th and 30th day by light microscopy morphometry and scanning electron microscopy. It was found that application of osteoplastic material Collapan in the femoral diaphysis defect optimised reparative osteogenesis, showed high biocompatibility, osteo-conductive properties, resorption ability and good integration with tissue-specific structures of the regenerate

  9. Assessment of periapical health, quality of root canal filling, and ...

    African Journals Online (AJOL)

    Sixty three teeth were found to have short root canal fillings, whereas 74 teeth had adequate root canal fillings, and the remaining 10 teeth had over extended root canal filling. A significant correlation was observed between the length of root filling and apical periodontitis (P = 0,023). Inadequately dense root canal filling was ...

  10. Thermal properties of defective fullerene

    Science.gov (United States)

    Li, Jian; Zheng, Dong-Qin; Zhong, Wei-Rong

    2016-09-01

    We have investigated the thermal conductivity of defective fullerene (C60) by using the nonequilibrium molecular dynamics (MD) method. It is found that the thermal conductivity of C60 with one defect is lower than the thermal conductivity of perfect C60. However, double defects in C60 have either positive or negative influence on the thermal conductivity, which depends on the positions of the defects. The phonon spectra of perfect and defective C60 are also provided to give corresponding supports. Our results can be extended to long C60 chains, which is helpful for the thermal management of C60.

  11. NSLS-II filling pattern measurement

    International Nuclear Information System (INIS)

    Yong Hu; Dalesio, L.B.; Kiman Ha; Pinayev, I.

    2012-01-01

    Multi-bunch injection will be deployed at NSLS-II. High bandwidth diagnostic beam monitors with high speed digitizers are used to measure bunch-by-bunch charge variation. In order to minimize intensity-correlated orbit oscillations due to uneven bunch patterns, we need to measure the filling pattern (also named bunch pattern or bunch structure). This paper focuses on filling pattern measurements: how to measure bunch structure and make this information available in EPICS-based control system. This measurement requires combination of 3 types of beam monitors (Wall Current Monitor, Fast Current Transformer and Beam Position Monitor), data acquisition and controls (fast digitizer, EPICS software, etc.) and Event Timing system. High-bandwidth filling pattern monitor requires high-speed digitizer to sample its analog output signal. The evaluation results of commercial fast digitizer Agilent Acqiris and high bandwidth detector Bergoz FCT are presented. We have also tested the algorithm software for filling pattern measurement as well as the interface to event timing system. It appears that filling pattern measurement system is well understood and the tests for control hardware and software have given good results

  12. Point defects in nickel

    International Nuclear Information System (INIS)

    Peretto, P.

    1969-01-01

    The defects in electron irradiated nickel (20 deg. K) or neutron irradiated nickel (28 deg. K) are studied by simultaneous analysis using the magnetic after-effect, electron microscopy and electrical resistivity recovery. We use zone refined nickel (99.999 per cent) which, for some experiments, is alloyed with a small amount of iron (for example 0.1 per cent Fe). The temperature dependant electrical recovery may be divided in four stages. The sub-stages I B (31 deg. K), I C (42 deg. K), I D (from to 57 deg. K) and I E (62 deg. K) of stage I are due to the disappearance of single interstitials into vacancies. The interstitial defect has a split configuration with a migration energy of about 0.15 eV. In the close pair which disappears in stage I B the interstitial is found to be in a 3. neighbour position whilst in stage I D it is near the direction from the vacancy. In stage I E there is no longer any interaction between the interstitial and the vacancy. The stage II is due to more complicated interstitial defects: di-interstitials for stage II B (84 deg. K) and larger and larger interstitial loops for the following sub-stages. The loops may be seen by electron microscopy. Impurities can play the role of nucleation centers for the loops. Stages III A (370 deg. K) and III B (376 deg. K) are due to two types of di-vacancies. During stage IV (410 deg. K) the single vacancies migrate. Vacancy type loops and interstitial type loops grow concurrently and disappear at about 800 deg. K as observed by electron microscopy. (author) [fr

  13. Single ventricle cardiac defect

    International Nuclear Information System (INIS)

    Eren, B.; Turkmen, N.; Fedakar, R.; Cetin, V.

    2010-01-01

    Single ventricle heart is defined as a rare cardiac abnormality with a single ventricle chamber involving diverse functional and physiological defects. Our case is of a ten month-old baby boy who died shortly after admission to the hospital due to vomiting and diarrhoea. Autopsy findings revealed cyanosis of finger nails and ears. Internal examination revealed; large heart, weighing 60 grams, single ventricle, without a septum and upper membranous part. Single ventricle is a rare pathology, hence, this paper aims to discuss this case from a medico-legal point of view. (author)

  14. Posterior bulk-filled resin composite restorations.

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    Purpose/aim: To evaluate in a randomized controlled study the 5-year clinical durability of a flowable resin composite bulk-fill technique in Class I and Class II restorations. Materials and methods: 38 pairs Class I and 62 pairs Class II restorations were placed in 44 male and 42 female (mean age...... 52.4 years). Each patient received at least two, as similar as possible, extended Class I or Class II restorations. In all cavities, a 1-step self-etch adhesive (Xeno V+) was applied. Randomized, one of the cavities of each pair received the flowable bulk-filled resin composite (SDR), in increments...... up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using...

  15. Fissure fillings from Finnsjoen and Studsvik Sweden

    International Nuclear Information System (INIS)

    Tullborg, E.-L.; Larsson, S.Aa.

    1982-12-01

    Samples were taken from cores and collected at different levels. The bedrock at Finnsjoen is a Svecokarelian granite-granodiorite, the most frequent mineral in the fissures being calcite. The water from boreholes have a mean S 18 O value of -12 per thousand and saturated by calcite. Isotopically three different groups of calcite have been distinguished. Ages of 29+-13x10 3 years to 79+-25x10 3 years were estimated. Two generations of quartz were recognized the minerals prehnite and lanmontite were found Most fissure filling materials have cation exchange capacities. The bedrock at Studsvik is a Svecokarelian gneiss of sedimentary type which is migmatized with calcite and chlorite as fissure filling minerals. Most fissure fillings are thin and simple Claby minerals of smectite type are also frequent. (G.B.)

  16. One-dimensional Gromov minimal filling problem

    International Nuclear Information System (INIS)

    Ivanov, Alexandr O; Tuzhilin, Alexey A

    2012-01-01

    The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.

  17. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    Science.gov (United States)

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  18. Dipole defects in beryl

    International Nuclear Information System (INIS)

    Holanda, B A; Cordeiro, R C; Blak, A R

    2010-01-01

    Dipole defects in gamma irradiated and thermally treated beryl (Be 3 Al 2 Si 6 O 18 ) samples have been studied using the Thermally Stimulated Depolarization Currents (TSDC) technique. TSDC experiments were performed in pink (morganite), green (emerald), blue (aquamarine) and colourless (goshenite) natural beryl. TSDC spectra present dipole peaks at 190K, 220K, 280K and 310K that change after gamma irradiation and thermal treatments. In morganite samples, for thermal treatments between 700K and 1100K, the 280K peak increase in intensity and the band at 220K disappears. An increase of the 280K peak and a decrease of the 190K peak were observed in the TSDC spectra of morganite after a gamma irradiation of 25kGy performed after the thermal treatments. In the case of emerald samples, thermal treatments enhanced the 280K peak and gamma irradiation partially destroyed this band. The goshenite TSDC spectra present only one band at 280K that is not affected either by thermal treatments or by gamma irradiation. All the observed peaks are of dipolar origin because the intensity of the bands is linearly dependent on the polarization field, behaviour of dipole defects. The systematic study, by means of TSDC measurements, of ionizing irradiation effects and thermal treatments in these crystals makes possible a better understanding of the role played by the impurities in beryl crystals.

  19. A clinical study on the efficacy of hydroxyapatite - Bioactive glass composite granules in the management of periodontal bony defects

    Directory of Open Access Journals (Sweden)

    Tirthankar Debnath

    2014-01-01

    Full Text Available Background: In periodontal regeneration, several alloplastic materials are being used with a goal to reconstruct new osseous tissue in the infrabony defect sites. The present study was undertaken to evaluate the efficacy of hydroxyapatite-bioactive glass (HA:BG composite granules in the management of periodontal bony defects. Materials and Methods: A randomized control study was conducted. Subjects with infrabony defects were divided into three groups. Test Group 1 (n = 10: Defect site was treated with HA:BG, with a biodegradable membrane. Test Group 2 (n = 10: Defect site was treated with HAP, with a biodegradable membrane. Control group (n = 10: Defect site was treated with open flap debridement with a biodegradable membrane Results: The healing of defects was uneventful and free of any biological complications. The gain in clinical attachment level, reduction of probing pocket depth, and defect fill were statistically significant in all three groups. TG1 sites showed significant defect fill than TG2 and CG sites. Conclusion: The performance of HA:BG was better compared to HAP and open flap debridement for the reconstruction of infrabony defects.

  20. Intermittent surface water connectivity: Fill and spill vs. fill and merge dynamics

    Science.gov (United States)

    Leibowitz, Scott G.; Mushet, David M.; Newton, Wesley E.

    2016-01-01

    Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining differences in response was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes.

  1. Evaluation of Amnion-derived Multipotent Progenitor (AMP) Cells and Amnion-derived Cellular Cytokine Solution (ST266) in Promoting Craniomaxillofacial Regenerative Bone Healing in Critical Size Calvarial Defects

    Science.gov (United States)

    2017-10-10

    NAVAL MEDICAL RESEARCH UNIT SAN ANTONIO EVALUATION OF AMNION-DERIVED MULTIPOTENT PROGENITOR ( AMP ) CELLS AND AMNION-DERIVED...Care International AMP Amnion-derived multipotent progenitor BCA Bicinchoninic acid BS/BV Bone surface/bone volume BV/TV Bone volume/tissue... AMP ) cells release ST266, a secretome of biomolecules identified as integral to the process of bone regeneration and angiogenesis. The AMP cells

  2. The structure of filled skutterudites and the local vibration behavior of the filling atom

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiaojuan [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dongguan Institute of Neutron Science, Dongguan 523808 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zong, Peng-an [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Chen, Xihong [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Tao, Juzhou, E-mail: taoj@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dongguan Institute of Neutron Science, Dongguan 523808 (China); Lin, He, E-mail: linhe@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201204 (China)

    2017-02-15

    Both of atomic pair distribution function (PDF) and extended x-ray absorption fine structure (EXAFS) experiments have been carried out on unfilled and Yb-filled skutterudites Yb{sub x}Co{sub 4}Sb{sub 12} (x=0, 0.15, 0.2 and 0.25) samples. The structure refinements on PDF data confirm the large amplitude vibration of Yb atom and the dependence of Yb vibration amplitude on the filling content. Temperature dependent EXAFS experiment on filled skutterudites have been carried out at Yb L{sub Ⅲ}-edge in order to explore the local vibration behavior of filled atom. EXAFS experiments show that the Einstein temperature of the filled atom is very low (70.9 K) which agrees with the rattling behavior.

  3. Use of cyanoacrylate as barrier in guided tissue regeneration in class II furcation defects

    Directory of Open Access Journals (Sweden)

    Carmen L Mueller Storrer

    2014-01-01

    Full Text Available The guided bone regeneration (GBR is a technique that uses resorbable and non-resorbable membranes in association with other filling biomaterials. GBR is one of the optional treatments for therapy of class II furcation defects. The current case report evaluates clinically and radiographically the use of the cyanoacrylate membrane (Glubran ®2 associated with organic bovine bone (GenOx for the treatment of vestibular class II furcation defect on the lower left molar. Conclusion: The GBR is an option in the treatment of vestibular class II furcation defects and cyanoacrylate surgical glue, acting as a mechanic barrier and providing an efficient stability for the graft.

  4. Defect-related electronic metastabilities in chalcopyrite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Maria S., E-mail: maria.hammer@uni-oldenburg.de [Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg, 26111 Oldenburg (Germany); Neugebohrn, Nils; Riediger, Julia; Neerken, Janet; Ohland, Jörg; Riedel, Ingo [Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg, 26111 Oldenburg (Germany); Kiowski, Oliver; Wischmann, Wiltraud [Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Industriestr. 6, 70565 Stuttgart (Germany)

    2014-04-15

    So far, in Cu(In,Ga)Se{sub 2} solar cells the metastable behavior of the key parameters, i.e. open circuit voltage, short circuit current and fill factor, and the corresponding defect physics were typically investigated independently. In order to contribute to this issue, we systematically varied between annealed and light soaked state and investigated the influence of these processes on the solar cell parameters as well as on the defect physics. In this work, we attempt to correlate the key parameters of the solar cells and the defect physics by discussing experimental results obtained from temperature dependent current–voltage measurements (IVT) as well as from capacitance voltage (CV), admittance (AS) and deep-level transient spectroscopy (DLTS). A commonly observed defect contribution in Cu(In,Ga)Se{sub 2} solar cells is the so-called N1 signature. The activation energy of this signature was found to increase upon air-annealing in the dark which goes along with a decrease in the open circuit voltage and the effective doping density. In this paper we will discuss the correlation between annealing-induced shifting of defect energies and the variation of the key parameters.

  5. Study on typical hole defects in AZ91D magnesium alloy prepared by low pressure lost foam casting

    Directory of Open Access Journals (Sweden)

    Li Jiqiang

    2013-07-01

    Full Text Available The hole defects can easily occur in magnesium alloy castings that are prepared by low pressure lost foam casting (LP-LFC process when the process parameters such as vacuum, pouring temperature and filling velocity are not properly selected. In this study, the forming mechanism of the hole defects in AZ91D magnesium castings by LP-LFC process was investigated. The shape, location and surface appearance of the hole defects were observed using optical microscopy and scanning electron microscopy, and the chemical composition on the surface of the holes was analyzed using energy spectrometer. The result indicates that there are two types of hole defects, i.e., the pyrolysis products related hole defects, including concentrative hole and blow hole defects, and slag related hole defects. The concentrative hole and the blow-hole defects were formed either by the liquid-EPS degradation products entrapped in the molten metal under the condition that the pouring temperature is equal to or lower than 730 ℃, or by the hindered transport of EPS pyrolysis products. Some irregular shape hole defects were caused by slag or by coating slough entrapment when the pouring temperature is equal to 750 ℃ and the filling velocity is equal to or greater than 100 mm·s-1. To reduce or eliminate the hole defects, the vacuum and filling velocity must be properly chosen to ensure that the metal front profile exhibits convex shape and in laminar current state, and the pouring temperature should be just high enough to ensure that the molten melt has adequate heat energy to complete the foam pyrolysis and to fully occupy the mould. For AZ91D magnesium castings in this study, the parameters should be 730 ℃ pouring temperature, 0.02-0.03 MPa vacuum and 80 mm·s-1 filling velocity.

  6. Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer.

    LENUS (Irish Health Repository)

    O'Duffy, F

    2012-02-01

    AiM: The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in \\'dead space\\' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials. METHOD: In this case a 68 year old presented with ascending colon adenocarcinoma invading the peritoneum and underwent en bloc peritoneal resection. Thirty-seven months later surveillance CT identified a local recurrence. Subsequent resection resulted in a large iliacus muscle defect which would sequester small bowel loops thus exposing the patient to radiation enteropathy. The lateral position of the defect precluded the use of traditional pelvic partitioning methods which would be unlikely to remain in place long enough to allow radiotherapy. A lightweight air-filled breast prosthesis (Allergan 133 FV 750 cms) secured in place with an omentoplasty was used to fill the defect. RESULTS: Following well tolerated radiotherapy the prosthesis was deflated under ultrasound guidance and removed via a 7-cm transverse incision above the right iliac crest. The patient is disease free 18 months later with no evidence of treatment related morbidity. CONCLUSION: The use of a malleable air-filled prosthesis for pelvic partitioning allows specific tailoring of the prosthesis size and shape for individual patient defects. It is also lightweight enough to be secured in place using an omentoplasty to prevent movement related prosthesis migration. In the absence of adequate omentum a mesh sling may be considered to allow fixation. In this case the anatomy of the prosthesis position allowed for its

  7. Electroviscous effects in capillary filling of nanochannels

    DEFF Research Database (Denmark)

    Mortensen, Asger; Kristensen, Anders

    2008-01-01

    We theoretically examine the widespread hypothesis of an electroviscous origin of the increase in apparent viscosity observed in recent experiments on capillary filling of nanochannels. Including Debye-layer corrections to the hydraulic resistance, we find that the apparent viscosity reaches...

  8. Biomineral nanoparticles are space-filling

    Science.gov (United States)

    Yang, Li; Killian, Christopher E.; Kunz, Martin; Tamura, Nobumichi; Gilbert, P. U. P. A.

    2011-02-01

    Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals.Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals. This article was submitted as part of a Themed Issue on Crystallization and Formation Mechanisms of Nanostructures. Other papers on this topic can be found in issue 11 of vol. 2 (2010). This issue can be found from the Nanoscale homepage [http://www.rsc.org/nanoscale

  9. Safety distances for hydrogen filling stations

    NARCIS (Netherlands)

    Matthijsen, A J C M; Kooi, E S

    2006-01-01

    In the context of spatial planning the Dutch Ministry of Housing, Spatial Planning and the Environment asked the Centre for External Safety of the National Institute for Public Health and the Environment (RIVM) to advice on safe distances pertaining to hydrogen filling stations. The RIVM made use of

  10. Stock keeping unit fill rate specification

    NARCIS (Netherlands)

    Teunter, R. H.; Syntetos, A. A.; Babai, M. Z.

    2017-01-01

    The fill rate is the most widely applied service level measure in industry and yet there is minimal advice available on how it should be differentiated on an individual Stock Keeping Unit (SKU) basis given that there is an overall system target service level. The typical approach utilized in

  11. Stability of fruit bases and chocolate fillings

    Directory of Open Access Journals (Sweden)

    Joice Natali Miquelim

    2011-03-01

    Full Text Available Syrups with high sugar content and dehydrated fruits in its composition can be added to chocolate fillings to reduce the need of artificial flavor and dyes attributing a natural appeal to the product. Fruit bases were produced with lyophilized strawberry, passion fruit, and sliced orange peel. Rheological dynamic oscillatory tests were applied to determine the products stability and tendency of shelf life. Values of G´ G´´ were found for orange flavor during the 90 days of storage. It was observed that shear stress values did not vary significantly suggesting product stability during the studied period. For all fillings, it was found a behavior similar to the fruit base indicating that it has great influence on the filling behavior and its stability. The use of a sugar matrix in fillings provided good shelf life for the fruit base, which could be kept under room temperature conditions for a period as long as one year. The good stability and storage conditions allow the use of fruit base for handmade products as well as for industrialized products.

  12. Banach spaces that realize minimal fillings

    Energy Technology Data Exchange (ETDEWEB)

    Bednov, B. B.; Borodin, P. A., E-mail: noriiii@inbox.ru, E-mail: pborodin@inbox.ru [Faculty of Mechanics and Mathematics, Moscow State University (Russian Federation)

    2014-04-30

    It is proved that a real Banach space realizes minimal fillings for all its finite subsets (a shortest network spanning a fixed finite subset always exists and has the minimum possible length) if and only if it is a predual of L{sub 1}. The spaces L{sub 1} are characterized in terms of Steiner points (medians). Bibliography: 25 titles. (paper)

  13. Form Filling with Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2002-01-01

    This paper describes a newly started Ph.D. project with the aim of simulating the form filling ability of Self-Compacting Concrete (SCC) taking into account the form geometry, reinforcement configuration, casting technique, and the rheological properties of the concrete. Comparative studies...

  14. Creep of granulated loose-fill insulation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    with SP-Building Physics in Sweden and VTT Building Technology in Finland. For the round robin test a cellulosic fibre insulation material was used. The proposed standardised method for creep tests and theories are limited to cases when the granulated loose-fill material is exposed to a constant......, Organisation for Testing in Scandinavia funded the Nordtest....

  15. Dielectric properties of nanosilica filled epoxy nanocomposites

    Indian Academy of Sciences (India)

    M G Veena

    This paper presents the development of epoxy-silica nanocomposites and characterized for dielectric properties. The effect of ... However, at higher silica loading TEM showed inter-contactity of the particles. The dielectric constant (e. 0. ) ..... of the mechanical and permeability properties of nano- and micron-TiO2 filled epoxy ...

  16. Topological defects in extended inflation

    International Nuclear Information System (INIS)

    Copeland, E.J.; Kolb, E.W.; Chicago Univ., IL; Liddle, A.R.

    1990-04-01

    We consider the production of topological defects, especially cosmic strings, in extended inflation models. In extended inflation, the Universe passes through a first-order phase transition via bubble percolation, which naturally allows defects to form at the end of inflation. The correlation length, which determines the number density of the defects, is related to the mean size of bubbles when they collide. This mechanism allows a natural combination of inflation and large-scale structure via cosmic strings. 18 refs

  17. Diaphragmatic defect in trisomy 13

    International Nuclear Information System (INIS)

    Reinbold, W.D.; Reinwein, H.; Back, E.

    1986-01-01

    Congenital diaphragmatic defect is often combined with other malformations that are severe or fatal. The rare finding of a congenital diaphragmatic defect in a newborn with trisomy 13 is reported. The newborn died within 2 days. Postmortem examination showed typical malformations due to trisomy 13 besides a diaphragmatic defect of left retrosternal position. Karyotype revealed a 13/14 translocation of trisomy 13. (orig.) [de

  18. Topological defects in extended inflation

    International Nuclear Information System (INIS)

    Copeland, E.J.; Kolb, E.W.; Liddle, A.R.

    1990-01-01

    We consider the production of topological defects, especially cosmic strings, in extended-inflation models. In extended inflation, the Universe passes through a first-order phase transition via bubble percolation, which naturally allows defects to form at the end of inflation. The correlation length, which determines the number density of the defects, is related to the mean size of the bubbles when they collide. This mechanism allows a natural combination of inflation and large-scale structure via cosmic strings

  19. Who named the quantum defect?

    Energy Technology Data Exchange (ETDEWEB)

    Rau, A.R.P. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; Inokuti, M. [Argonne National Lab., IL (United States). Physics Div.

    1997-08-01

    The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term quantum defect does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schroedinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. The authors present the early history of the quantum-defect idea, and sketch its recent developments.

  20. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  1. Studies of defects and defect agglomerates by positron annihilation spectroscopy

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Singh, B.N.

    1997-01-01

    A brief introduction to positron annihilation spectroscopy (PAS), and in particular lo its use for defect studies in metals is given. Positrons injected into a metal may become trapped in defects such as vacancies, vacancy clusters, voids, bubbles and dislocations and subsequently annihilate from...

  2. Appositional bone formation in marginal defects at implants.

    Science.gov (United States)

    Botticelli, Daniele; Berglundh, Tord; Buser, Daniel; Lindhe, Jan

    2003-02-01

    In a previous experiment, it was demonstrated that a wide marginal defect around an implant can heal with a high degree of osseointegration. The present experiment was performed to evaluate the degree and quality of de novo bone formation and osseointegration in marginal defects adjacent to submerged titanium implants. All mandibular premolars and 1st molars were extracted in four Labrador dogs. Four experimental sites were identified in the right side of the mandible. In two sites, custom-made implants with a sandblasted, large grit, acid-etched (SLA) surface were installed without further ostectomy (control sites). In the two remaining sites (test sites), a specially designed step drill was used to widen the marginal 5 mm of the canal. A barrier membrane was used to cover the implants in the defect sites. All implants were submerged. One month later, an identical procedure, including site preparation and implant installation, was performed in the left side of the mandible. Two months following the first implant installation procedure, biopsies were collected and prepared for sectioning. Ostectomy and implant installation in the control location resulted in a series of bone tissue alterations which eventually allowed newly formed bone to establish contact with the SLA surface. The marginal defect lateral to the implant in the test locations gradually became filled with newly formed bone. De novo bone formation started within the walls of the surgically prepared defect. Bone-to-implant contact was first established in the apical portion of the gap. This new bone tissue was in the coronal direction continuous with a dense, non-mineralized 'implant attached' soft tissue which, over time, also became mineralized to increase the height of the zone of bone-to-implant contact. The results suggest that healing of a wide marginal defect around an implant is characterized by appositional bone growth from the lateral and apical bone walls of the defect.

  3. Guided Wave Scattering and Mixed Mode Conversions from 3-Dimensional Defects

    Science.gov (United States)

    Luo, W.; Zhao, Xiaoliang; Rose, J. L.

    2005-04-01

    Ultrasonic guided waves have shown great potential for long range inspections of structures with large areas, such as pipes, vessels, rails, etc. The possibility of finding defects depends on whether scattered waves from a defect are detectable. For example, for a liquid-filled pipeline inspection using torsional waves, the incident waves may be converted to longitudinal waves, which could then leak into the liquid and become undetectable. Therefore, the wave mode conversion study of a defect, especially a 3-dimensional defect, becomes an interesting and valuable topic. The wave scattering and mode conversion of a through-wall hole in a plate was studied both experimentally and theoretically. Mixed mode conversions from SH modes to Lamb modes were demonstrated utilizing electromagnetic acoustic transducer (EMAT) guided wave techniques and a hybrid 3-D boundary element method. This mixed mode study could provide very useful guidance for guided wave inspection methodology. It is also very helpful in algorithm development for defect discrimination and sizing.

  4. Birth defects surveillance in China.

    Science.gov (United States)

    Dai, Li; Zhu, Jun; Liang, Juan; Wang, Yan-Ping; Wang, He; Mao, Meng

    2011-11-01

    Birth defects are a global public health problem because of their large contribution to infant mortalities and disabilities. It is estimated that 4%-6% of Chinese newborns are affected by birth defects every year. Surveillance is a basic approach to understanding the occurrence and associated factors of birth defects. The Ministry of Health of China initiated a national hospital-based birth defects monitoring system 20 years ago. Nearly every province in this country has established its own surveillance system in the past. The authors reviewed the result of the monitoring system at different administrative levels in China. Available publications on the surveillance of birth defects and data from national and provincial birth defects surveillance systems were reviewed to evaluate the effectiveness of the surveillance systems. According to the 2009 data, the national hospital-based birth defects surveillance system monitored over 1.3 million births, which accounted for more than 8% of births in China. In addition, 30 provincial hospital-based surveillance programs covered a birth population of more than 3.6 million (22% of births in China). Great achievements have been made in terms of case ascertainment, data quality control, and online reporting. But the surveillance systems in China still have some limitations. A short ascertainment period may miss some internal anomalies, inherited metabolic diseases, and malformed fetus aborted before the 28th gestational week. Discrepancies in antenatal or postnatal diagnosis of birth defects between surveillance institutes may affect the detection rate and introduce biases. Absence of baseline data and lack of integrated database systems limit the application of surveillance data to etiological studies and affect the process of decision-making. The surveillance system for birth defects is prerequisite to propose, conduct and assess any interventions for the disease. To meet the need of study and prevention of birth defects

  5. 7 CFR 52.774 - Fill of container.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Fill of container. 52.774 Section 52.774 Agriculture... United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Fill of Container § 52.774 Fill of container. (a) FDA requirements. Canned red tart pitted cherries shall meet the fill of container...

  6. Voids in Sonic Fill(TM) restorations compared to traditional incrementally-filled composite restorations

    Science.gov (United States)

    Abourezq, Ibraheem A.

    SonicFill(TM) is a new composite resin and delivery system designed to provide rapid filling of cavity preparations by decreasing viscosity through application of sonic energy. However, it may produce unwanted air voids in the final restoration due to the short filling time. Air voids compromise long-term performance by providing weak foci, discontinuity at cavosurface margins and at internal cavity walls, and potential crack propagation. This study assessed the locations, sizes, and numbers of voids in SonicFill restorations compared with traditional composite resin restorations in a set of extracted molars with mesio-occlusal-distal (MOD) cavity preparations. Fifty noncarious intact extracted third molars were collected randomly from a large collection of discarded anonymous tooth specimens. Standardized MOD cavity preparations were cut, and teeth were assigned randomly to one of two groups ( n = 25). The first group was restored with SonicFill composite in two steps. The second group was restored with Herculite Ultra(TM) using an multiple increment layering technique (1-2 mm per layer). Cross-sectional images of the filling were taken by digital microscope. A total of 196 voids were found in the 50 specimens: 97 in SonicFill restorations and 99 in conventional restorations. Mean number of voids in SonicFill restorations was 3.88 versus 3.96 for conventional restorations. Mean percentage of void area in SonicFill restorations was 0.588% versus 0.508% for conventional restorations. Unpaired t tests for these differences indicated no statistically significant differences (p =.931 and p =.629, respectively). One-way ANOVA tests for mean void count and mean void area percentage differences by three location zones for conventional and SonicFill restorations also indicated no significant differences among the groups. The bulk-fill SonicFill system does not result in increased or decreased numbers or ii area of voids within Class II MOD restorations compared with a

  7. Incidence of Dentinal Defects and Vertical Root Fractures after Endodontic Retreatment and Mechanical Cycling.

    Science.gov (United States)

    De Carlo Bello, Mariana; Pillar, Rafael; Mastella Lang, Pauline; Michelon, Carina; Abreu da Rosa, Ricardo; Souza Bier, Carlos Alexandre

    2017-01-01

    The aim of this study was to evaluate the incidence of dentinal defects and vertical root fractures (VRFs) after endodontic retreatment and mechanical cycling (MC). Two hundred mandibular premolars were selected. Forty teeth were left unprepared (control group). The remaining 160 root canals were prepared with ProTaper instruments and filled by using two different techniques [eighty with lateral compaction (LC) and eighty with single-cone (SC)]. Forty canals from each group (LC and SC) received no further treatment. The remaining eighty teeth were divided into two groups (LCR and SCR) ( n =40) in order to undergo the removal of the root filling, re-preparation and refilling with lateral compaction and single-cone, respectively. All of the teeth were subjected to MC (1000000 cycles, 130 N, 2.2 Hz and 37 ° C). The roots were sectioned at 3, 6 and 9 mm from the apex and observed under 20× magnification. The defects were classified as: no defect, VRF and other defects . Statistical analysis was performed using the Fisher's Exact test and the Chi -Squared tests ( α =0.05). MC alone did not promote any other defects or VRFs. Experimental groups presented higher dentinal defects than the control group ( P =0.021). Retreatment groups did not present a higher amount of dentinal defects than the groups that were subjected to the first treatment ( P >0.05). Endodontic treatment and retreatment, regardless of the filling technique and MC, did not influence the occurrence of dentinal defects or VRFs in the human premolars.

  8. Application of pulsed flash thermography method for specific defect estimation in aluminum

    Directory of Open Access Journals (Sweden)

    Tomić Ljubiša D.

    2015-01-01

    Full Text Available Nondestructive thermal examination can uncover the presence of defects via temperature distribution profile anomalies that are created on the surface as a result of a defect. There are many factors that affect the temperature distribution map of the surface being tested by Infrared Thermography. Internal defect properties such as thermal conductivity, heat capacity and defect depth, play an important role in the temperature behavior of the pixels or regions being analyzed. Also, it is well known that other external factors such as the convection heat transfer, variations on the surface emissivity and ambient radiation reflectivity can affect the thermographic signal received by the infrared camera. In this paper we considered a simple structure in the form of flat plate covered with several defects, whose surface we heated with a uniform heat flux impulse. We conducted a theoretical analysis and experimental test of the method for case of defects on an aluminum surface. First, experiments were conducted on surfaces with intentionally created defects in order to determine conditions and boundaries for application of the method. Experimental testing of the pulsed flash thermography (PFT method was performed on simulated defects on an aluminum test plate filled with air and organic compound n-hexadecane, hydrocarbon that belongs to the Phase Change Materials (PCMs. Study results indicate that it is possible, using the PFT method, to detect the type of material inside defect holes, whose presence disturbs the homogeneous structure of aluminum.

  9. Ocular Defects in Photosensitive Epilepsy

    Directory of Open Access Journals (Sweden)

    Ebere C. Anyanwu

    2004-01-01

    Full Text Available Patients with photosensitive epilepsy are susceptible to seizures due to photoparoxysmal response (PPR. This response adversely precipitates factors that modify the functional status of the visual system. Such factors may or may not be evident superficially, but may lead to ocular defects due to trauma, hormonal imbalance, abnormal intraocular pressure (IOP, or any other reflex-inducing stimuli. The extent to which photosensitive epileptic patients suffer from PPR-related ocular defects has not been documented fully. In this investigation, ocular defects in patients with photosensitive epilepsy are studied using visual-evoked response (VER. A total of 212 photosensitive epileptic patients were studied to ascertain the magnitude and distribution of ocular defects using the changes in EEG and visual-evoked potential (VEP; 51% of the patients were female, the age range was 1–46 years. The major ocular defects and complications found were visual field defects, optic nerve abnormalities, nystagmus, cataracts, amblyopia, and migraine. These findings were analyzed according to age and sex. The relationship between the ocular abnormalities and the interpretations of the changes in the characteristics of the VEP indicated that optic-related atrophies, visual defects, optic neuritis, chiasmal compression, nystagmus, migraine headache, cataracts, and amblyopia were prevalent in photosensitive epileptic patients at varying degrees. The results showed that although ocular defects in photosensitive epilepsy may not be obvious differentially, VEP can be used in their diagnosis, contrary to earlier studies reporting that VEP is not of much value in epilepsy diagnosis.

  10. Space mapping and defect correction

    NARCIS (Netherlands)

    Echeverría, D.; Hemker, P.W.

    2005-01-01

    In this paper we show that space-mapping optimization can be understood in the framework of defect correction. Then, space-mapping algorithms can be seen as special cases of defect correction iteration. In order to analyze the properties of space mapping and the space-mapping function, we introduce

  11. Birth defects surveillance·

    African Journals Online (AJOL)

    1989-07-01

    Jul 1, 1989 ... A pilot birth defects surveillance system was established in. 1982 as part of an epidemiological baseline study pertaining to potential changes in water quality in the Cape Peninsula. The methodology used for reporting birth defects for two information systems, one hospital-based and the other popu-.

  12. The Berkeley gas-filled separator

    CERN Document Server

    Ninov, V; McGrath, C A

    1998-01-01

    The BGS is being constructed at the 88-Inch Cyclotron at LBNL in Berkeley. The magnetic configuration of the BGS will allow a large angular acceptance and good suppression of primary beam particles. BGS operates as a mass spectrometer with a A/ Delta A approximately =200 and as a gas filled separator at pressures between 0.1-50 hPa. The reaction products recoiling off a thin target will be collected with efficiencies from 10-80at the focal plane. A Monte Carlo simulation program of the ion transport through the gas-filled magnets in combination of 3-dimensional TOSCA field maps has been developed and reproduces closely the experimental behavior of BGS. (9 refs).

  13. Environmental aspects of dental filling materials.

    Science.gov (United States)

    Arenholt-Bindslev, D

    1998-04-01

    In recent years, the possible environmental impact caused by certain routines in dental practice has attracted attention among regulators. As part of point source reduction strategies, the discharge of mercury/amalgam-contaminated wastes has been regulated in a number of countries, even though it has been documented that by adopting appropriate mercury hygiene measures, including installation of amalgam-separating devices, the environmental impact of amalgam use in dentistry is minimal. There are, so far, no data indicating the environmental impact of methacrylate-based dental filling materials. As to the occupational environment, recent reports have stated that when normal occupational recommendations for proper mercury hygiene routines are followed (e.g., water spray coolant and high vacuum suction during removal of amalgam restorations), no occupational health risk can be assumed. An increasing number of reports on occupational allergic reactions to components of polymer-based dental filling materials call for attention to the sensitizing potential of certain ingredients in these products.

  14. Flammability of Gas-Filled Polymers

    Directory of Open Access Journals (Sweden)

    Ushkov Valentin Anatol'evich

    2017-09-01

    Full Text Available The regularities of flame propagation on the horizontal surface of gas-filled polymers are considered depending on the concentration of oxygen in the oxidizer flow. The values of the coefficients in the expression describing relationship between the rate of flame propagation on the surface of foams and oxygen concentration are obtained. It was shown that with the mass content of reactive organophosphorus compounds reaching 4.0...5.9%, non-smoldering resole foam plastics with high performance characteristics are obtained. It was found that in order to obtain moderately combustible polyurethane foams based on oxyethylated phosphorus-containing polyols, the phosphorus concentration should not exceed 3 % of mass. To obtain flame-retardant urea-formaldehyde foam cellular plastics, the concentration of phosphorus should not exceed 0.3 % of mass. Physical-mechanical properties and flammability indices of developed gas-filled polymers based on reactive oligomers are presented.

  15. Holographic Chern-Simons defects

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Mitsutoshi [Department of Physics and Astronomy, University of Kentucky,Lexington, KY 40506 (United States); Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan); Melby-Thompson, Charles M. [Department of Physics, Fudan University,220 Handan Road, 200433 Shanghai (China); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study (UTIAS),The University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan); Meyer, René [Department of Physics and Astronomy, Stony Brook University,Stony Brook, New York 11794-3800 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study (UTIAS),The University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan); Sugimoto, Shigeki [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI),The University of Tokyo Institutes for Advanced Study (UTIAS),The University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan)

    2016-06-28

    We study SU(N) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.

  16. Toward Intelligent Software Defect Detection

    Science.gov (United States)

    Benson, Markland J.

    2011-01-01

    Source code level software defect detection has gone from state of the art to a software engineering best practice. Automated code analysis tools streamline many of the aspects of formal code inspections but have the drawback of being difficult to construct and either prone to false positives or severely limited in the set of defects that can be detected. Machine learning technology provides the promise of learning software defects by example, easing construction of detectors and broadening the range of defects that can be found. Pinpointing software defects with the same level of granularity as prominent source code analysis tools distinguishes this research from past efforts, which focused on analyzing software engineering metrics data with granularity limited to that of a particular function rather than a line of code.

  17. Full-waveform inversion: Filling the gaps

    KAUST Repository

    Beydoun, Wafik B.

    2015-09-01

    After receiving an outstanding response to its inaugural workshop in 2013, SEG once again achieved great success with its 2015 SEG Middle East Workshop, “Full-waveform inversion: Filling the gaps,” which took place 30 March–1 April 2015 in Abu Dhabi, UAE. The workshop was organized by SEG, and its partner sponsors were Saudi Aramco (gold sponsor), ExxonMobil, and CGG. Read More: http://library.seg.org/doi/10.1190/tle34091106.1

  18. Defect forces, defect couples and path integrals in fracture mechanics

    International Nuclear Information System (INIS)

    Roche, R.L.

    1979-07-01

    In this work, it is shown that the path integrals can be introduced without any reference to the material behavior. The method is based on the definition in a continuous medium of a set of vectors and couples having the dimension of a force or a moment. More precisely, definitions are given of volume defect forces, surface defect forces, volume defect couples, and surface defect couples. This is done with the help of the stress working variation of a particule moving through the solid. The most important result is: the resultant of all the defect forces included in a volume V is the J integral on the surface surrounding V and the moment resultant is the L integral. So these integrals are defined without any assumption on the material constitutive equation. Another result is the material form of the virtual work principle - defect forces are acting like conventional forces in the conventional principles of virtual work. This lead to the introduction of the energy momentum tensor and of the associated couple stress. Application of this method is made to fracture mechanics in studying the defect forces distribution around a crack [fr

  19. Brachistochrone curve of a fluid filled cylinder

    Science.gov (United States)

    Sarma, Srikanth; Raja, Sharan; Mahapatra, Pallab Sinha; Panchangnula, Mahesh

    2017-11-01

    The brachistochrone curve for a non-dissipative particle tries to maximize inertia of the particle but for a fluid filled cylinder, increasing inertia would amount to high dissipative losses. Hence the trade off between inertia and dissipation plays a vital role in the dynamics of a fluid filled cylinder. This trade off manifests itself in the form of an integro-differential equation governing the angular acceleration of the cylinder. Here, we compute the brachistochrone curve using optimal control principles and investigate the effect of the fore mentioned trade off on the deviation of the brachistochrone curve from that of a non-dissipative particle. Also, we investigate the effects of the non-dimensional parameters of the problem on the shape of the brachistochrone curve. We analyze the dissipation rate during the cylinder's motion and show that energy based arguments don't hold good for a fluid filled cylinder. We then analyze the stability of the time varying fluid flow in the cylinder and find an admissible region for the terminal point which would ensure the stability of the fluid flow as the cylinder rolls over the brachistochrone curve.

  20. Boron filled siloxane polymers for radiation shielding

    Science.gov (United States)

    Labouriau, Andrea; Robison, Tom; Shonrock, Clinton; Simmonds, Steve; Cox, Brad; Pacheco, Adam; Cady, Carl

    2018-03-01

    The purpose of the present work was to evaluate changes to structure-property relationships of 10B filled siloxane-based polymers when exposed to nuclear reactor radiation. Highly filled polysiloxanes were synthesized with the intent of fabricating materials that could shield high neutron fluences. The newly formulated materials consisted of cross-linked poly-diphenyl-methylsiloxane filled with natural boron and carbon nanofibers. This polymer was chosen because of its good thermal and chemical stabilities, as well as resistance to ionizing radiation thanks to the presence of aromatic groups in the siloxane backbone. Highly isotopically enriched 10B filler was used to provide an efficient neutron radiation shield, and carbon nanofibers were added to improve mechanical strength. This novel polymeric material was exposed in the Annular Core Research Reactor (ACRR) at Sandia National Labs to five different neutron/gamma fluxes consisting of very high neutron fluences within very short time periods. Thermocouples placed on the specimens recorded in-situ temperature changes during radiation exposure, which agreed well with those obtained from our MCNP simulations. Changes in the microstructural, thermal, chemical, and mechanical properties were evaluated by SEM, DSC, TGA, FT-IR NMR, solvent swelling, and uniaxial compressive load measurements. Our results demonstrate that these newly formulated materials are well-suitable to be used in applications that require exposure to different types of ionizing conditions that take place simultaneously.

  1. Fate of Pathogenic Bacteria Associated with Production of Pickled Sausage by Using a Cold Fill Process.

    Science.gov (United States)

    Gaydos, Nelson J; Cutter, Catherine N; Campbell, Jonathan A

    2016-10-01

    Preservation by pickling has been used for many years to extend the shelf life of various types of food products. By storing meat products in a brine solution containing an organic acid, salt, spices, as well as other preservatives, the pH of the product is reduced, thus increasing the safety and shelf life of the product. Pickling may involve the use of heated brines to further add to the safety of the food product. When precooked, ready-to-eat (RTE) sausages are pickled with a heated brine solution, the process is referred to as hot filling. However, hot filling has been shown to affect the clarity of the brine, making the product cloudy and unappealing to consumers. Because of the potential quality defects caused by higher temperatures associated with hot fill pickling, cold fill pickling, which uses room temperature brine, is preferred by some pickled sausage manufacturers. Because little information exists on the safety of cold fill, pickled sausages, a challenge study was designed using a brine solution (5% acetic acid and 5% salt at 25°C) to pickle precooked, RTE sausages inoculated with a pathogen cocktail consisting of Salmonella Typhimurium, Salmonella Senftenberg, Salmonella Montevideo, Listeria monocytogenes , and Staphylococcus aureus . All pathogens were reduced ~6.80 log CFU/g in 72 h when enumerated on nonselective media. On selective media, Salmonella and L. monocytogenes decreased 6.33 and 6.35 log CFU/g in 12 h, respectively whereas S. aureus was reduced 6.80 log CFU/g in 24 h. Sausages experienced significant (P ≤ 0.05) decreases in pH over the 28 days of storage, whereas no significant differences were observed in water activity (P =0.1291) or salt concentration of the sausages (P =0.1445) or brine (P =0.3180). The results of this experiment demonstrate that cold fill pickling can effectively reduce and inhibit bacterial pathogens.

  2. Modified Whale's tail technique for the management of bone-defect in anterior teeth.

    Science.gov (United States)

    Kuriakose, Anu; Ambooken, Majo; Jacob, Jayan; John, Priya

    2015-01-01

    The purpose of this case report is to describe the efficacy of a modified Whale's tail technique to achieve primary closure and thereby aid in regeneration of an interdental osseous defect between maxillary central incisors complicated by an aberrant frenal attachment. A healthy 32-year-old female patient reported with the complaint of spacing between her upper front teeth. Clinical examination revealed an aberrant frenum extending into the interdental papilla in relation to the central incisors. There was a 6 mm periodontal pocket in relation to the mesiopalatal aspect of maxillary left central incisor. Intraoral periapical radiograph showed vertical bone loss in relation to mesial aspect of maxillary left central incisor. A modified Whale's tail flap was employed to access the area. The defect was filled with an alloplastic graft. Six months postoperative review showed complete elimination of the pocket along with radiographic bone fill of the defect.

  3. Statistical evaluation of metal fill widths for emulated metal fill in parasitic extraction methodology

    Science.gov (United States)

    J-Me, Teh; Noh, Norlaili Mohd.; Aziz, Zalina Abdul

    2015-05-01

    In the chip industry today, the key goal of a chip development organization is to develop and market chips within a short time frame to gain foothold on market share. This paper proposes a design flow around the area of parasitic extraction to improve the design cycle time. The proposed design flow utilizes the usage of metal fill emulation as opposed to the current flow which performs metal fill insertion directly. By replacing metal fill structures with an emulation methodology in earlier iterations of the design flow, this is targeted to help reduce runtime in fill insertion stage. Statistical design of experiments methodology utilizing the randomized complete block design was used to select an appropriate emulated metal fill width to improve emulation accuracy. The experiment was conducted on test cases of different sizes, ranging from 1000 gates to 21000 gates. The metal width was varied from 1 x minimum metal width to 6 x minimum metal width. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the interconnect net capacitance values of the different test cases. This paper presents the results of the statistical analysis for the 45 nm process technology. The recommended emulated metal fill width was found to be 4 x the minimum metal width.

  4. Condition Assessment of PC Tendon Duct Filling by Elastic Wave Velocity Mapping

    Directory of Open Access Journals (Sweden)

    Kit Fook Liu

    2014-01-01

    Full Text Available Imaging techniques are high in demand for modern nondestructive evaluation of large-scale concrete structures. The travel-time tomography (TTT technique, which is based on the principle of mapping the change of propagation velocity of transient elastic waves in a measured object, has found increasing application for assessing in situ concrete structures. The primary aim of this technique is to detect defects that exist in a structure. The TTT technique can offer an effective means for assessing tendon duct filling of prestressed concrete (PC elements. This study is aimed at clarifying some of the issues pertaining to the reliability of the technique for this purpose, such as sensor arrangement, model, meshing, type of tendon sheath, thickness of sheath, and material type as well as the scale of inhomogeneity. The work involved 2D simulations of wave motions, signal processing to extract travel time of waves, and tomography reconstruction computation for velocity mapping of defect in tendon duct.

  5. Serine biosynthesis and transport defects.

    Science.gov (United States)

    El-Hattab, Ayman W

    2016-07-01

    l-serine is a non-essential amino acid that is biosynthesized via the enzymes phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). Besides its role in protein synthesis, l-serine is a potent neurotrophic factor and a precursor of a number of essential compounds including phosphatidylserine, sphingomyelin, glycine, and d-serine. Serine biosynthesis defects result from impairments of PGDH, PSAT, or PSP leading to systemic serine deficiency. Serine biosynthesis defects present in a broad phenotypic spectrum that includes, at the severe end, Neu-Laxova syndrome, a lethal multiple congenital anomaly disease, intermediately, infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end, the childhood disease with intellectual disability. A serine transport defect resulting from deficiency of the ASCT1, the main transporter for serine in the central nervous system, has been recently described in children with neurological manifestations that overlap with those observed in serine biosynthesis defects. l-serine therapy may be beneficial in preventing or ameliorating symptoms in serine biosynthesis and transport defects, if started before neurological damage occurs. Herein, we review serine metabolism and transport, the clinical, biochemical, and molecular aspects of serine biosynthesis and transport defects, the mechanisms of these diseases, and the potential role of serine therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. 2010 Defects in Semiconductors GRC

    Energy Technology Data Exchange (ETDEWEB)

    Shengbai Zhang

    2011-01-06

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, as well as an emphasis on the development of novel defect detection methods and first-principles defect theories. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference will deal with point and extended defects in a broad range of electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, oxides, sp{sup 2} carbon based-materials, and photovoltaic/solar cell materials, and in understanding important defect phenomena such as doping bottleneck in nanostructures and the diffusion of defects and impurities. The program consists of about twenty invited talks and a number of contributed poster sessions. The emphasis should be on work which has yet to be published. The large amount of discussion time provides an ideal forum for dealing with topics that are new and/or controversial.

  7. Is bone transplantation the gold standard for repair of alveolar bone defects?

    Directory of Open Access Journals (Sweden)

    Cassio Eduardo Raposo-Amaral

    2014-01-01

    Full Text Available New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and α-tricalcium phosphate, compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7 defects were repaired with autogenous bone grafts; Group 2 (n = 5 defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5 defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5 defects were repaired with α-tricalcium phosphate free of cells; and Group 5 (n = 6 defects were repaired with α-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2–5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01 and 38.35% ± 19.59% (p = 0.06 of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30 and 61.80% ± 2.14% (p = 0.88 of bone in the defect, respectively. Animals whose bone defects were repaired with α-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone.

  8. When Your Baby Has a Birth Defect

    Science.gov (United States)

    ... Search English Español When Your Baby Has a Birth Defect KidsHealth / For Parents / When Your Baby Has ... to help you and your child. What Are Birth Defects? Birth defects (also called congenital anomalies) are ...

  9. Treatment of a cervical resorptive defect in a mandibular first premolar: An 18-month follow-up

    Directory of Open Access Journals (Sweden)

    Hare Gürsoy

    2014-12-01

    Full Text Available The objective of this report is to describe the multidisciplinary management of a cervical resorptive defect using periodontal surgery, endodontic treatment, mineral trioxide aggregate (MTA and composite resin filling. The resorptive defect was obturated using MTA following the reflection of a mucoperiosteal flap and conventional root canal treatment was completed. The cervical extension of the MTA-filled cavity, which was evident following the suturing of the flap, was reduced and filled with a composite filling material. No complaints were noted by the patient and at the 18-month follow-up the prognosis was favorable. By appropriate multidisciplinary management, root resorptions may be treated successfully. MTA may serve as a good option in such situations owing to its multi-beneficial properties.

  10. Defect detection based on extreme edge of defective region histogram

    Directory of Open Access Journals (Sweden)

    Zouhir Wakaf

    2018-01-01

    Full Text Available Automatic thresholding has been used by many applications in image processing and pattern recognition systems. Specific attention was given during inspection for quality control purposes in various industries like steel processing and textile manufacturing. Automatic thresholding problem has been addressed well by the commonly used Otsu method, which provides suitable results for thresholding images based on a histogram of bimodal distribution. However, the Otsu method fails when the histogram is unimodal or close to unimodal. Defects have different shapes and sizes, ranging from very small to large. The gray-level distributions of the image histogram can vary between unimodal and multimodal. Furthermore, Otsu-revised methods, like the valley-emphasis method and the background histogram mode extents, which overcome the drawbacks of the Otsu method, require preprocessing steps and fail to use the general threshold for multimodal defects. This study proposes a new automatic thresholding algorithm based on the acquisition of the defective region histogram and the selection of its extreme edge as the threshold value to segment all defective objects in the foreground from the image background. To evaluate the proposed defect-detection method, common standard images for experimentation were used. Experimental results of the proposed method show that the proposed method outperforms the current methods in terms of defect detection.

  11. Fissure fillings from Gideaa, central Sweden

    International Nuclear Information System (INIS)

    Tullborg, E.L.; Larsson, S.Aa.

    1983-08-01

    The most frequent fissure filling minerals at Gideaa are calcite, chlorite, pyrite, laumontite, stilbite, smectite, quartz and epidote. Potentially young minerals, i.e. minerals which can be formed during present conditions, are smectite, calcite and quartz, Equilibrium calculations show that these minerals can be stable in the water analysed from Gideaa. In borehole Gi 2, the water exhibits a greater equilibrium with existing minerals in the fissures than water from Gi 4. This is due to the recharge of the water in Gi 4 and discharge of the water in Gi 2. When carbonate saturated water penetrated through the bedrock, calcite precipitated within the more superficial portions of the rock. However, both calcite and zeolite fissures fillings are associated with certain zones in the drill holes. A large number of fractures can be concluded to be of post-Jotnian age. Stilbite, calcite and smectite are associated with these fractures. Laumontite can also be assumed to belong here. The dolerites in the area exhibit a high fracture frequency but a relatively low hydraulic conductivity. This is due to the fact that smectite is very prevalent in the dolerite fractures, Several generations of fracturefilling minerals (above all calcite) have been found in a single fracture. Stable isotope analyses of fissure filling calcites indicate that there are three different groups of calcite. Most of the calcites could not have been precipitated from water of present-day isotope composition at Gideaa, whereas recent calcite may be found in one of the groups. Another group of calcite was precipitated during hydro-thermal conditions.(author)

  12. Hydraulic fracturing of rock-fill dam

    Directory of Open Access Journals (Sweden)

    Jun-Jie WANG

    2016-02-01

    Full Text Available The condition in which hydraulic fracturing in core of earth-rock fill dam maybe induced, the mechanism by which the reason of hydraulic fracturing canbe explained, and the failure criterion by which the occurrence of hydraulicfracturing can be determined, were investigated. The condition dependson material properties such as, cracks in the core and low permeability ofcore soil, and “water wedging” action in cracks. An unsaturated core soiland fast impounding are the prerequisites for the formation of “waterwedging” action. The mechanism of hydraulic fracturing can be explainedby fracture mechanics. The crack propagation induced by water pressuremay follow any of mode I, mode II and mixed mode I-II. Based on testingresults of a core soil, a new criterion for hydraulic fracturing was suggested,from which mechanisms of hydraulic fracturing in the core of rock-fill damwere discussed. The results indicated that factors such as angle betweencrack surface and direction of principal stress, local stress state at thecrack, and fracture toughness KIC of core soil may largely affect theinduction of hydraulic fracturing and the mode of the propagation of thecrack.The condition in which hydraulic fracturing in core of earth-rock fill dam maybe induced, the mechanism by which the reason of hydraulic fracturing canbe explained, and the failure criterion by which the occurrence of hydraulicfracturing can be determined, were investigated. The condition dependson material properties such as, cracks in the core and low permeability ofcore soil, and “water wedging” action in cracks. An unsaturated core soiland fast impounding are the prerequisites for the formation of “waterwedging” action. The mechanism of hydraulic fracturing can be explainedby fracture mechanics. The crack propagation induced by water pressuremay follow any of mode I, mode II and mixed mode I-II. Based on testingresults of a core soil, a new criterion for hydraulic fracturing

  13. Carbon Nanotubes Filled with Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Albrecht Leonhardt

    2010-08-01

    Full Text Available Carbon nanotubes (CNT filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology.

  14. Birth Defects Data and Statistics

    Science.gov (United States)

    ... Submit" /> Information For… Media Policy Makers Data & Statistics Recommend on Facebook Tweet Share Compartir On This ... and critical. Read below for the latest national statistics on the occurrence of birth defects in the ...

  15. What Are Congenital Heart Defects?

    Science.gov (United States)

    ... of a Normal Heart and a Heart With Tetralogy of Fallot Figure A shows the structure and blood flow ... shows a heart with the four defects of tetralogy of Fallot. Babies and children who have tetralogy of Fallot ...

  16. Birth Defects Research and Tracking

    Science.gov (United States)

    ... Environmental public health tracking is the ongoing collection, integration, analysis, interpretation, and dissemination of data on environmental ... 2016) Key Findings: Gastroschisis – a Serious Birth Defect – Continues to Increase New CDC research shows that the ...

  17. Influence of cover defects on the attenuation of radon with earthen covers

    International Nuclear Information System (INIS)

    Kalkwarf, D.R.; Mayer, D.W.

    1983-11-01

    Experimental and theoretical evaluations of radon flux through laboratory-scale defective soil columns are presented together with a survey of literature on the formation and prevention of defects in soil covers. This report focuses on air-filled, centimeter-scale defects that are most probable in earthen covers for attenuating radon emission from uranium-mill tailings. Examples include shirnkage and erosion cracks, erosion piping, animal burrows and air channels formed by the biodegradation of vegetation roots. Calculations based on mathematical models indicate that collections of defects which could increase the radon flux from an earthen cover by a factor of two would be easily detected by visual inspection. However, these models ignore air-turbulence in the defect and drying of the soil around the defect. Laboratory measurements showed that turbulent diffusion of radon occurred through defects as narrow as 0.3 cm when subjected to a transverse air velocity of 1 to 6 miles per hour at the surface. Both turbulence and more-rapid drying of soil can accelerate radon flux to the cover surface. Consequently, recommended methods to inhibit defect formation should be applied. 29 references, 3 figures, 5 tables

  18. Defects in semiconductors

    International Nuclear Information System (INIS)

    Tilly, L.

    1993-04-01

    In this thesis, experimental results of the transition metals Ti, V, Nb, Mo, and W as impurity centres in silicon are presented. Transition metal doping was accomplished by ion implantation. Emphasis is put on energy level position, electrical and optical properties of the encountered defect levels. Junction space charge methods (JSCM) such as DLTS, photocapacitance and photocurrent techniques are employed. Three energy levels are found for the 3d-transition metals Ti(E c -0.06eV, E c -0.30eV, E v +0.26) and V(E c -0.21eV, E c -0,48e, E v +0.36eV), and for the 4d-element Nb(E c -0.29eV, E c -0.58eV, E v +0.163eV) in Silicon, whereas only one transition metal induced level is found for Mo(E v +0.30eV) and W(E v +0.38eV) respectively. Electrical and optical characteristics of Si 1-x Ge x ,0.7 7 cm -2 . The solvent Bi, used in the LPE-process, is found to be the dominant impurity element. Furthermore, liquid phase epitaxy of high purity In 0.53 Ga 0.57 As on InP, together with the properties of the Cu-induced acceptor in this material are examined. Free electron concentrations of n=5x10 14 cm -3 and electron Hall-mobilities of μ 77K = 44000 cm 2 /Vs are achieved. The energy level position of the Cu-acceptor is found to be E v +0.025eV. Photoluminescence and Hall-effect measurements, together with JSCM are the main characterization methods used. The band linups of In 0.53 Ga 0.47 As with GaAs and with InP are determined according to the Cu-acceptor energy level position in these materials. Additionally, the hydrostatic pressure dependence of the Cu-acceptor energy level position in In 0.53 Ga 0.47 As is examined. (103 refs.)

  19. Gamma-induced defect production in ZrO2-Y2O3 crystals with different defectiveness

    International Nuclear Information System (INIS)

    Ashurov, M.Kh.; Amonov, M.Z.; Rakov, A.F.

    2002-01-01

    Full text: The defectiveness degree of ZrO 2 -Y 2 O 3 crystals depends on stabilizer concentration. The work is aimed at study gamma-induced defect production in crystals with different concentration of stabilizer and defects generated by neutron irradiation. Absorption spectra were measured with Specord M-40. It was found, that after gamma-irradiation of as-grown crystals up to some dose the intensity of absorption band at 420 nm reaches the maximum level of saturation. The dose of saturation depends of the concentration of stabilizer. It means that gamma-radiation does not produce any additional defects of structure. The oxygen vacancies existing in as-grown crystals are filled by the radiation induced electrons. Since the number of oxygen vacancies depends on the stabilizer concentration, then all these vacancies can be occupied by electrons at different gamma-doses. In crystals pre-irradiated with different neutron fluences followed by gamma-irradiation, the intensity of absorption bands at 420 and 530 nm increases in two stages. The gamma-dose of the second stage beginning decreases as the neutron fluence grows. The first stage of the absorption increase is due to developing of vacancies existing in as-grown crystals. The second stage is caused by generation of additional vacancies as the result of non-radiative exciton decay near the existing structure damages. The decrease of the gamma-dose, when the second stage of vacancy accumulation begins, results from the neutron induced structure damage degree

  20. Cranioplasty of an extremely large cranial defect caused by transitional meningioma with a knitted polypropylen-polyester prothesis "Codubix".

    Science.gov (United States)

    Kotwica, Z; Zawirski, M; Andrzejak, S; Papierz, W; Chmielowski, M

    1991-01-01

    The authors report a case of transitional cell meningioma of the convexity which destroyed a large portion of the calvarium and invaded subcutaneous tissue. The tumour was totally removed and a large cranial defect/430 cm2 in size/was filled with a polypropylenopolyester knitted prothesis "Codubix" with an excellent result. The problems of chronioplastic closure of such an unusually large skull defect and the advantages of the use of the material "Codubix" are discussed.

  1. Treatment of Degree II Furcation Defects Using Autogenous Grafts with and without Alendronate - A Split Mouth Clinical Study

    Directory of Open Access Journals (Sweden)

    Sujit Kumar

    2014-01-01

    Results: Both the experimental groups showed significant reduction in probing pocket depth, gain in clinical attachment level and mean percentage of horizontal defect fill (41.82% vs 49.09% at 6 months. Experimental sites in group B showed a significant loss in mean vertical defect height compared to experimental group A (1.52% Vs -1.59%. Conclusion: It can be suggested that bisphosphonates such as alendronate sodium have the potential to inhibit the surgery induced bone loss.

  2. Topological defects from the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun; Vilenkin, Alexander [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Blanco-Pillado, Jose J. [Department of Theoretical Physics, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Garriga, Jaume, E-mail: jun.zhang@tufts.edu, E-mail: josejuan.blanco@ehu.es, E-mail: jaume.garriga@ub.edu, E-mail: vilenkin@cosmos.phy.tufts.edu [Departament de Fisica Fonamental i Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti i Franques, 1, 08028, Barcelona (Spain)

    2015-05-01

    Many theories of the early universe predict the existence of a multiverse where bubbles continuously nucleate giving rise to observers in their interior. In this paper, we point out that topological defects of several dimensionalities will also be produced in de Sitter like regions of the multiverse. In particular, defects could be spontaneously nucleated in our parent vacuum. We study the evolution of these defects as they collide with and propagate inside of our bubble. We estimate the present distribution of defects in the observable part of the universe. The expected number of such nearby defects turns out to be quite small, even for the highest nucleation rate. We also study collisions of strings and domain walls with our bubble in our past light cone. We obtain simulated full-sky maps of the loci of such collisions, and find their angular size distribution. Similarly to what happens in the case of bubble collisions, the prospect of detecting any collisions of our bubble with ambient defects is greatly enhanced in the case where the cosmological constant of our parent vacuum is much higher than the vacuum energy density during inflation in our bubble.

  3. Topological defects from the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Blanco-Pillado, Jose J. [Department of Theoretical Physics, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, 48013, Bilbao (Spain); Garriga, Jaume [Departament de Fisica Fonamental i Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti i Franques, 1, 08028, Barcelona (Spain); Vilenkin, Alexander [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)

    2015-05-28

    Many theories of the early universe predict the existence of a multiverse where bubbles continuously nucleate giving rise to observers in their interior. In this paper, we point out that topological defects of several dimensionalities will also be produced in de Sitter like regions of the multiverse. In particular, defects could be spontaneously nucleated in our parent vacuum. We study the evolution of these defects as they collide with and propagate inside of our bubble. We estimate the present distribution of defects in the observable part of the universe. The expected number of such nearby defects turns out to be quite small, even for the highest nucleation rate. We also study collisions of strings and domain walls with our bubble in our past light cone. We obtain simulated full-sky maps of the loci of such collisions, and find their angular size distribution. Similarly to what happens in the case of bubble collisions, the prospect of detecting any collisions of our bubble with ambient defects is greatly enhanced in the case where the cosmological constant of our parent vacuum is much higher than the vacuum energy density during inflation in our bubble.

  4. Electrical fingerprint of pipeline defects

    International Nuclear Information System (INIS)

    Mica, Isabella; Polignano, Maria Luisa; Marco, Cinzia De

    2004-01-01

    Pipeline defects are dislocations that connect the source region of the transistor with the drain region. They were widely reported to occur in CMOS, BiCMOS devices and recently in SOI technologies. They can reduce device yield either by affecting the devices functionality or by increasing the current consumption under stand-by conditions. In this work the electrical fingerprint of these dislocations is studied, its purpose is to enable us to identify these defects as the ones responsible for device failure. It is shown that the pipeline defects are responsible for a leakage current from source to drain in the transistors. This leakage has a resistive characteristic and it is lightly modulated by the body bias. It is not sensitive to temperature; vice versa the off-current of a good transistor exhibits the well-known exponential dependence on 1/T. The emission spectrum of these defects was studied and compared with the spectrum of a good transistor. The paper aims to show that the spectrum of a defective transistor is quite peculiar; it shows well defined peaks, whereas the spectrum of a good transistor under saturation conditions is characterized by a broad spectral light emission distribution. Finally the deep-level transient spectroscopy (DLTS) is tried on defective diodes

  5. Filling behaviour of wood plastic composites

    Science.gov (United States)

    Duretek, I.; Lucyshyn, T.; Holzer, C.

    2017-01-01

    Wood plastic composites (WPC) are a young generation of composites with rapidly growing usage within the plastics industry. The advantages are the availability and low price of the wood particles, the possibility of partially substituting the polymer in the mixture and sustainable use of the earth’s resources. The current WPC products on the market are to a large extent limited to extruded products. Nowadays there is a great interest in the market for consumer products in more use of WPC as an alternative to pure thermoplastics in injection moulding processes. This work presents the results of numerical simulation and experimental visualisation of the mould filling process in injection moulding of WPC. The 3D injection moulding simulations were done with the commercial software package Autodesk® Moldflow® Insight 2016 (AMI). The mould filling experiments were conducted with a box-shaped test part. In contrast to unfilled polymers the WPC has reduced melt elasticity so that the fountain flow often does not develop. This results in irregular flow front shapes in the moulded part, especially at high filler content.

  6. Liquid-filled ionization chamber temperature dependence

    Energy Technology Data Exchange (ETDEWEB)

    Franco, L. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain)]. E-mail: luciaff@usc.es; Gomez, F. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Iglesias, A. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pardo, J. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pazos, A. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pena, J. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Zapata, M. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain)

    2006-05-10

    Temperature and pressure corrections of the read-out signal of ionization chambers have a crucial importance in order to perform high-precision absolute dose measurements. In the present work the temperature and pressure dependences of a sealed liquid isooctane filled ionization chamber (previously developed by the authors) for radiotherapy applications have been studied. We have analyzed the thermal response of the liquid ionization chamber in a {approx}20 deg. C interval around room temperature. The temperature dependence of the signal can be considered linear, with a slope that depends on the chamber collection electric field. For example, a relative signal slope of 0.27x10{sup -2}K{sup -1} for an operation electric field of 1.67x10{sup 6}Vm{sup -1} has been measured in our detector. On the other hand, ambient pressure dependence has been found negligible, as expected for liquid-filled chambers. The thermal dependence of the liquid ionization chamber signal can be parametrized within the Onsager theory on initial recombination. Considering that changes with temperature of the detector response are due to variations in the free ion yield, a parametrization of this dependence has been obtained. There is a good agreement between the experimental data and the theoretical model from the Onsager framework.

  7. Pairing in half-filled Landau level

    Science.gov (United States)

    Wang, Zhiqiang; Mandal, Ipsita; Chung, Suk Bum; Chakravarty, Sudip

    2015-03-01

    Pairing of composite fermions in half-filled Landau level state is reexamined by solving the BCS gap equation with full frequency dependent current-current interactions. Our results show that there can be a continuous transition from the Halperin-Lee-Read state to a chiral odd angular momentum Cooper pair state for short-range contact interaction. This is at odds with the previously established conclusion of first order pairing transition, in which the low frequency effective interaction was assumed for the entire frequency range. We find that even if the low frequency effective interaction is repulsive, it is compensated by the high frequency regime, which is attractive. We construct the phase diagrams and show that l = 1 angular momentum channel is quite different from higher angular momentum channel l >= 3 . Remarkably, the full frequency dependent analysis applied to the bilayer Hall system with a total filling fraction ν =1/2 +1/2 is quantitatively changed from the previously established results but not qualitatively. This work was supported by US NSF under the Grant DMR-1004520, the funds from the David S. Saxon Presidential Chair at UCLA(37952), and by the Institute for Basic Science in Korea through the Young Scientist grant (5199-2014003).

  8. Vancomycin graft composite for infected bone defects

    International Nuclear Information System (INIS)

    Winkler, H.; Janata, O.; Georgopoulos, A.

    1999-01-01

    Reconstructive surgery under septic conditions represents a major challenge in orthopaedics. Local application of antibiotics can provide high drug levels at the site of infection without systemic effects. However, removal of non-resorbable implants and filling of defects usually requires additional operative procedures. An ideal antibiotic carrier should provide for : 1) Effective bactericidal activity, especially against staphylococci including MRSA; 2) High and long lasting levels at the site of infection without local or systemic toxicity; 3) Repair of defects without a second stage procedure. Allogeneic cancellous bone is proven to be effective in restoration of bone stock. Vancomycin is effective against all gram-positive populations and the agent of choice for infections with MRSA. The aim of our study is to investigate the efficacy of a combination of both components in bone infection. Cancellous bone of human origin was processed during several steps and incubated in 10% vancomycin solution. The antimicrobial activity of the vancomycin graft composite (VGC) was evaluated using an agar diffusion bioassay against staphylococcus aureus and high performance liquid chromatography (HPLC). The testing period was up to 9 weeks. Elution of vancomycin from the graft was evaluated in 2.5% human albumin solution, which was exchanged every 24 hours. Concentration of vancomycin in allograft-bone was between 6.653[tg/g and 23.194gg/g with an average of 15.250 [tg/g, which is equivalent to 10.000 times the minimum inhibitory concentration (MIC) for s. aureus. The initial activity decreased to approx. 50% during the first week and approx. 30% at the end of the 9th week. The lowest values measured exceeded the MIC by 2000 times. Concentration in surrounding fluid decreased from 24.395,80 to 18,43pg/ml after 11 complete exchanges. Human cancellous bone, processed in an adequate way, offers capability to store high quantities of vancomycin. Vancomycin graft composites are

  9. The method of diagnosis and classification of the gingival line defects of the teeth hard tissues

    Directory of Open Access Journals (Sweden)

    Olena Bulbuk

    2017-06-01

    Full Text Available For solving the problem of diagnosis and treatment of hard tissue defects the significant role belongs to the choice of tactics for dental treatment of hard tissue defects located in the gingival line of any tooth. This work aims to study the problems of diagnosis and classification of gingival line defects of the teeth hard tissues. That will contribute to the objectification of differentiated diagnostic and therapeutic approaches in the dental treatment of various clinical variants of these defects localization. The objective of the study – is to develop the anatomical-functional classification for differentiated estimation of hard tissue defects in the gingival part, as the basis for the application of differential diagnostic-therapeutic approaches to the dental treatment of hard tissue defects disposed in the gingival part of any tooth. Materials and methods of investigation: There was conducted the examination of 48 patients with hard tissue defects located in the gingival part of any tooth. To assess the magnitude of gingival line destruction the periodontal probe and X-ray examination were used. Results. The result of the performed research the classification of the gingival line defects of the hard tissues was offered using exponent power. The value of this indicator is equal to an integer number expressed in millimeters of distance from the epithelial attachment to the cavity’s bottom of defect. Conclusions. The proposed classification fills an obvious gap in academic representations about hard tissue defects located in the gingival part of any tooth. Also it offers the prospects of consensus on differentiated diagnostic-therapeutic approaches in different clinical variants of location.  This classification builds methodological “bridge of continuity” between therapeutic and prosthetic dentistry in the field of treatment of the gingival line defects of dental hard tissues.

  10. Repair of segmental radial defect with autologous bone marrow aspirate and hydroxyapatite in rabbit radius: A clinical and radiographic evaluation

    Science.gov (United States)

    Yassine, Kalbaza Ahmed; Mokhtar, Benchohra; Houari, Hemida; Karim, Amara; Mohamed, Melizi

    2017-01-01

    Aim: Finding an ideal bone substitute to treat large bone defects, delayed union and nonunions remain a challenge for orthopedic surgeons and researchers. Several studies have been conducted on bone regeneration; each has its own advantages and disadvantages. The aim of this study was to evaluate the effect of a combination of hydroxyapatite (HA) powder with autologous bone marrow (BM) aspirate on the repair of segmental radial defect in a rabbit model. Materials and Methods: A total of 36 male and adult New Zealand rabbit with a mean weight of 2.25 kg were used in this study. Approximately, 5 mm defect was created in the mid-shaft of the radius to be filled with HA powder in the control group “HA” (n=18) and with a combination of HA powder and autologous BM aspirate in the test group “HA+BM” (n=18). Animals were observed daily for healing by inspection of the surgical site, and six rabbits of each group were sacrificed at 30, 60, and 90 post-operative days to perform a radiographic evaluation of defect site. Results: Obtained results revealed a better and more rapid bone regeneration in the test group: Since the defect was rapidly and completely filled with mature bone tissue after 90 days. Conclusion: Based on these findings, we could infer that adding a BM aspirate to HA is responsible of a better regeneration process leading to a complete filling of the defect. PMID:28831217

  11. Study on nano-structured hydroxyapatite/zirconia stabilized yttria on healing of articular cartilage defect in rabbit

    Directory of Open Access Journals (Sweden)

    Amir Sotoudeh

    2013-05-01

    Full Text Available PURPOSE: Articular Cartilage has limited potential for self-repair and tissue engineering approaches attempt to repair articular cartilage by scaffolds. We hypothesized that the combined hydroxyapatite and zirconia stabilized yttria would enhance the quality of cartilage healing. METHODS: In ten New Zealand white rabbits bilateral full-thickness osteochondral defect, 4 mm in diameter and 3 mm depth, was created on the articular cartilage of the patellar groove of the distal femur. In group I the scaffold was implanted into the right stifle and the same defect was created in the left stifle without any transplant (group II. Specimens were harvested at 12 weeks after implantation, examined histologically for morphologic features, and stained immunohistochemically for type-II collagen. RESULTS: In group I the defect was filled with a white translucent cartilage tissue In contrast, the defects in the group II remained almost empty. In the group I, the defects were mostly filled with hyaline-like cartilage evidenced but defects in group II were filled with fibrous tissue with surface irregularities. Positive immunohistochemical staining of type-II collagen was observed in group I and it was absent in the control group. CONCLUSION: The hydroxyapatite/yttria stabilized zirconia scaffold would be an effective scaffold for cartilage tissue engineering.

  12. Repair of segmental radial defect with autologous bone marrow aspirate and hydroxyapatite in rabbit radius: A clinical and radiographic evaluation

    Directory of Open Access Journals (Sweden)

    Kalbaza Ahmed Yassine

    2017-07-01

    Full Text Available Aim: Finding an ideal bone substitute to treat large bone defects, delayed union and nonunions remain a challenge for orthopedic surgeons and researchers. Several studies have been conducted on bone regeneration; each has its own advantages and disadvantages. The aim of this study was to evaluate the effect of a combination of hydroxyapatite (HA powder with autologous bone marrow (BM aspirate on the repair of segmental radial defect in a rabbit model. Materials and Methods: A total of 36 male and adult New Zealand rabbit with a mean weight of 2.25 kg were used in this study. Approximately, 5 mm defect was created in the mid-shaft of the radius to be filled with HA powder in the control group "HA" (n=18 and with a combination of HA powder and autologous BM aspirate in the test group "HA+BM" (n=18. Animals were observed daily for healing by inspection of the surgical site, and six rabbits of each group were sacrificed at 30, 60, and 90 post-operative days to perform a radiographic evaluation of defect site. Results: Obtained results revealed a better and more rapid bone regeneration in the test group: Since the defect was rapidly and completely filled with mature bone tissue after 90 days. Conclusion: Based on these findings, we could infer that adding a BM aspirate to HA is responsible of a better regeneration process leading to a complete filling of the defect.

  13. Impact of defects on electrical connectivity of monolayer of ideally aligned rods

    International Nuclear Information System (INIS)

    Tarasevich, Yu Yu; Dubinin, D O; Laptev, V V; Lebovka, N I

    2016-01-01

    The processes of formation of electrically conductive films filled by aligned elongated nanoparticles, i.e. nanotubes, nanowires or fibers attract great attention in nanotecnological applications. The alignment can be controlled by external electric fields, evaporation-driven self-assembly and assisted by different other techniques. This work studies the impact of defects on electrical connectivity of ideally aligned monolayer of rods (k-mers). By means of Monte Carlo simulation the problem of percolation for conductive rods on a discrete insulating substrate (square lattice) is analyzed. The aspect ratio of the particles changes within the interval 1-64, the insulating defects were distributed both on the lattice and on the particles. We found that even a very small amount of the insulating defects on the particles can destroy the electrical connectivity. The critical concentration of the defects decreases as the aspect ratio of the particles increases. (paper)

  14. 7 CFR 2902.20 - Fluid-filled transformers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Fluid-filled transformers. 2902.20 Section 2902.20... Items § 2902.20 Fluid-filled transformers. (a) Definition. (1) Synthetic ester-based fluid-filled transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non...

  15. Evaluation of Various Filling Techniques in Distal Canals of ...

    African Journals Online (AJOL)

    2017-03-06

    Mar 6, 2017 ... treatment.[10] The percentage of GP-filled areas (PGFAs) has been used as a measure of the quality of the root filling.[7] Therefore, the aim of this study was to compare different filling techniques in the distal canals of lower molars, instrumented by different single-file systems, and the canal area in terms of ...

  16. grain-filling, chlorophyll content in relation with grain yield

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    number of fertile tillers nor number of grains per m². Grain weight is, however, reduced (Hochman,. 1982) due to a shortening of the grain filling period resulting from accelerated senescence. A long duration of grain filling is often an indicator of photosynthetic activity optimum, but a high velocity of filling is indicative of water.

  17. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the...

  18. Radiopacity of bulk fill flowable resin composite materials | Yildirim ...

    African Journals Online (AJOL)

    Objectives: The purpose of this study was to evaluate the radiopacity of currently marketed bulk fill flowable dental composite materials (Beautifil Bulk Flowable, SDR Flow, Filtek Bulk Fill Flow, and x‑tra Base Bulk Fill). Materials and Methods: Six specimens of each material with a thickness of 1 mm were prepared, and ...

  19. Radiopacity of bulk fill flowable resin composite materials

    African Journals Online (AJOL)

    2015-08-23

    Aug 23, 2015 ... Objectives: The purpose of this study was to evaluate the radiopacity of currently marketed bulk fill flowable dental composite materials (Beautifil Bulk Flowable, SDR Flow, Filtek Bulk Fill Flow, and x‑tra Base Bulk Fill). Materials and Methods: Six specimens of each material with a thickness of 1 mm were ...

  20. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate, intended...

  1. Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study

    Directory of Open Access Journals (Sweden)

    Ayca Yilmaz

    2017-01-01

    Full Text Available The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9 μm resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

  2. Comparative study of NMP-preloaded and dip-loaded membranes for guided bone regeneration of rabbit cranial defects.

    Science.gov (United States)

    Karfeld-Sulzer, Lindsay S; Ghayor, Chafik; Siegenthaler, Barbara; Gjoksi, Bebeka; Pohjonen, Timo H; Weber, Franz E

    2017-02-01

    Guided bone regeneration (GBR) has been utilized for several decades for the healing of cranio-maxillofacial bone defects and, particularly in the dental field, by creating space with a barrier membrane to exclude soft tissue and encourage bone growth in the membrane-protected volume. Although the first membranes were non-resorbable, a new generation of GBR membranes aims to biodegrade and provide bioactivity for better overall results. The Inion GTR™ poly(lactide-co-glycolide) (PLGA) membrane is not only resorbable but also bioactive, since it includes N-methylpyrrolidone (NMP), which has been shown to promote bone regeneration. In this study, the effects of loading different amounts of NMP onto the membrane through chemical vapour deposition or dipping have been explored. In vitro release demonstrated that lower levels of NMP led to lower NMP concentrations and slower release, based on total NMP loaded in the membrane. The dipped membrane released almost all of the NMP within 15 min, leading to a high NMP concentration. For the in vivo studies in rabbits, 6 mm calvarial defects were created and left untreated or covered with an ePTFE membrane or PLGA membranes dipped in, or preloaded with, NMP. Evaluation of the bony regeneration revealed that the barrier membranes improved bony healing and that a decrease in NMP content improved the performance. Overall, we have demonstrated the potential of these PLGA membranes with a more favourable NMP release profile and the significance of exploring the effect of NMP on these PLGA membranes with regard to bone ingrowth. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  3. Alleviate Cellular Congestion Through Opportunistic Trough Filling

    Directory of Open Access Journals (Sweden)

    Yichuan Wang

    2014-04-01

    Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

  4. Internal Accident Report: fill it out!

    CERN Multimedia

    2012-01-01

    It is important to report all accidents, near-misses and dangerous situations so that they can be avoided in the future.   Reporting these events allows the relevant services to take appropriate action and implement corrective and preventive measures. It should be noted that the routing of the internal accident report was recently changed to make sure that the people who need to know are informed. Without information, corrective action is not possible. Without corrective action, there is a risk that the events will recur. As soon as you experience or see something amiss, fill out an internal accident report! If you have any questions the HSE Unit will be happy to answer them. Contact us at safety-general@cern.ch. The HSE Unit

  5. Form Filling with Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2007-01-01

    endvidere, at Teknologisk Institut vil kommercialisere projektets resultater. Abstract The overall subject of this project was Self-Compacting Concrete. More specifically it has been to establish a modelling approach for prediction of the form filling behaviour of SCC in a vertical formwork. Self...... of theoretical prediction tools is one of the main reasons for the haltering use of SCC in vertical applications. A lack of prediction tools may lead to selection of concrete mix compositions and casting techniques that are not suitable for a given application. This project proposes a modelling approach within...... to differences in density. In future constructions with Self-Compacting Concrete the proposed modelling approach may be applied to optimise the rheological parameters, particle configuration, and casting technique for a given application in order to obtain the structural quality required....

  6. LHC Abort Gap Filling by Proton Beam

    CERN Document Server

    Fartoukh, Stéphane David; Shaposhnikova, Elena

    2004-01-01

    Safe operation of the LHC beam dump relies on the possibility of firing the abort kicker at any moment during beam operation. One of the necessary conditions for this is that the number of particles in the abort gap should be below some critical level defined by quench limits. Various scenarios can lead to particles filling the abort gap. Time scales associated with these scenarios are estimated for injection energy and also coast where synchrotron radiation losses are not negligible for uncaptured particle motion. Two cases are considered, with RF on and RF off. The equilibrium distribution of lost particles in the abort gap defines the requirements for maximum tolerable relative loss rate and as a consequence the minimum acceptable longitudinal lifetime of the proton beam in collision.

  7. Aging Studies of Filled and Unfilled VCE

    Energy Technology Data Exchange (ETDEWEB)

    Letant, S; Herberg, J; Alviso, C; Small, W; Mulcahy, H; Pearson, M; Wilson, T; Chinn, S; Maxwell, R

    2009-11-10

    This report presents data on the effects of temperature and gamma radiation on the chemical and structural properties of both filled and unfilled VCE material produced by the Kansas City Plant using WR-qualified processes. Thermal effects up to 300 C and gamma irradiation doses of 1 MRad and 25 MRad were investigated under atmospheric conditions. Characterization techniques used in the study comprise Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Tensile Testing, Solid Phase MicroExtraction - Gas Chromatography/Mass Spectrometry (SPME-GC/MS), phenol extraction followed by HPLC, and various Nuclear Magnetic Resonance (NMR) techniques including: {sup 13}C, {sup 13}C {l_brace}{sup 1}H{r_brace} cross polarization (CP), {sup 1}H magic angle spinning (MAS), 13C{l_brace}{sup 1}H{r_brace} Wide-line-Separation (2D-WISE) and development of Center band-Only Detection of Exchange (CODEX).

  8. Pullulan/dextran/nHA macroporous composite beads for bone repair in a femoral condyle defect in rats.

    Directory of Open Access Journals (Sweden)

    Silke Schlaubitz

    Full Text Available The repair of bone defects is of particular interest for orthopedic, oral, maxillofacial, and dental surgery. Bone loss requiring reconstruction is conventionally addressed through bone grafting. Depending on the size and the location of the defect, this method has limits and risks. Biomaterials can offer an alternative and have features supporting bone repair. Here, we propose to evaluate the cellular penetration and bone formation of new macroporous beads based on pullulan/dextran that has been supplemented with nanocrystalline hydroxyapatite in a rat model. Cross-linked beads of 300-500 µm diameters were used in a lateral femoral condyle defect and analyzed by magnetic resonance imaging, micro-computed tomography, and histology in comparison to the empty defects 15, 30, and 70 days after implantation. Inflammation was absent for both conditions. For empty defects, cellularisation and mineralization started from the periphery of the defect. For the defects containing beads, cellular structures filling out the spaces between the scaffolds with increasing interconnectivity and trabecular-like organization were observed over time. The analysis of calcified sections showed increased mineralization over time for both conditions, but was more pronounced for the samples containing beads. Bone Mineral Density and Bone Mineral Content were both significantly higher at day 70 for the beads in comparison to empty defects as well as compared with earlier time points. Analysis of newly formed tissue around the beads showed an increase of osteoid tissue, measured as percentage of the defect surface. This study suggests that the use of beads for the repair of small size defects in bone may be expanded on to meet the clinical need for a ready-to-use fill-up material that can favor bone formation and mineralization, as well as promote vessel ingrowth into the defect site.

  9. Determination of defect content and defect profile in semiconductor heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Zubiaga, A [Laboratory of Physics, HUT, PO Box 1100, 02015 TKK, Espoo (Finland); Garcia, J A; Plazaola, F [Zientzia eta Teknologia Fakultatea, Euskal Herriko Unbertsitatea, P. K. 644, 48080, Bilbao (Spain); Zuniga-Perez, J; Munoz-Sanjose, V, E-mail: fernando.plazaola@ehu.es [Universitat de Valencia, Departamento de Fisica Aplicada i Electromagnetisme, Dr. Moliner 50, 46100 Burjassot, Valencia (Spain)

    2011-01-10

    In this article we present an overview of the technique to obtain the defects depth profile and width of a deposited layer and multilayer based on positron annihilation spectroscopy. In particular we apply the method to ZnO and ZnO/ZnCdO layers deposited on sapphire substrates. After introducing some terminology we first calculate the trend that the W/S parameters of the Doppler broadening measurements must follow, both in a qualitative and quantitative way. From this point we extend the results to calculate the width and defect profiles in deposited layer samples.

  10. Stoichiometric Defects in Silicon Carbide

    International Nuclear Information System (INIS)

    Liao, Ting; Bedoya-Martinez, O. N.; Roma, G.; Liao, Ting; Liao, Ting

    2010-01-01

    Defect structures showing odd-membered rings are known features of several tetrahedral semiconductors as well as carbon nano-structures; examples of them are bond defects in crystalline and amorphous silicon, Stone Wales defects in fullerenes and carbon nano-tubes, and the core structure of partial dislocations in some tetrahedral semiconductors. We investigate, using Density Functional Theory, two types of stoichiometry-conserving defects, which we call SCD and anti-SCD and which are metastable structures presenting five- and seven-membered rings, both in the cubic and in the hexagonal 4H-SiC polytypes. We also investigate the annealing properties of the two mentioned variants and find that one of them (SCD) easily disappears, turning back to a normal site, while the other (anti-SCD) transforms to an antisite pair, overcoming a barrier of 0. 21 eV. The very short lifetimes at ambient conditions explain why those defects have not been observed up to now, but they suggest they should be observable at very low temperature, and we provide local vibrational modes to facilitate their identification. (authors)

  11. Biocompatibility of retrograde root filling materials: a review.

    Science.gov (United States)

    Bodrumlu, Emre

    2008-04-01

    The aim of a retrograde filling material is to fill the apical canal space and to obtain a hermetic seal between the periodontium and the root canal system. Several materials have been suggested for root-end filling including: amalgam, gutta-percha, zinc oxide-eugenol cements, glass ionomer cement, gold foil pellets, Cavit, composite resin and mineral trioxide aggregate (MTA). Super-ethoxy benzoic acid and MTA are the most suitable materials and provide better results in apicoectomy procedures than other filling materials. Unfortunately, the ideal material for this purpose has yet to be found. This article is a review of the biocompatibility of retrograde filling materials.

  12. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2011-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level...... measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...

  13. "Product on Stopper" in a Lyophilized Drug Product: Cosmetic Defect or a Product Quality Concern?

    Science.gov (United States)

    Mehta, Shyam B; Roy, Shouvik; Yang, Han-Chang Cathy

    2018-02-09

    During manufacturing of a lyophilized drug product, operator errors in product handling during loading of product filled vials onto the lyophilizer can lead to a seemingly cosmetic defect which can impact certain critical quality attributes of finished product. In this study, filling of a formulated monoclonal antibody in vials was performed using a peristaltic pump filling unit, and subsequently, the product was lyophilized. After lyophilization, upon visual inspection, around 40% of vials had cosmetic defect with residual product around stopper of the vial and were categorized as "product on stopper" vials, whereas remaining 60% vials with no cosmetic defect were called "acceptable vials." Both groups of vials from 1 single batch were tested for critical quality attributes including protein concentration (ultraviolet absorbance at 280), residual moisture (Karl Fischer), sterility (membrane filtration), and container closure integrity (CCI) (blue dye ingress). Analysis of protein quality attributes such as aggregation, protein concentration, residual moisture showed no significant difference between vials with "product on stopper" and "acceptable vials." However, CCI of the "product on stopper" vials was compromised due to the presence of product around stopper of the vial. The results from this case study demonstrate the following 2 important findings: (1) that a seemingly cosmetic defect may impact product quality, compromising the integrity of the product and (2) that CCI test method can be used as an orthogonal method to sterility testing to evaluate sterility assurance of the product. The corrective action proposed to mitigate this defect is use of a larger sized vial that can potentially minimize this defect that arises because of product handling errors. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  14. Defect CFTs and holographic multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Fiol, Bartomeu, E-mail: bfiol@ub.edu [Departament de Física Fonamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08193 Barcelona (Spain)

    2010-07-01

    We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by an M5-brane probe embedding in AdS{sub 4} × S{sup 7}, and studying its spectrum of fluctuations. Our results suggest that the kind of behavior required by the spectrum of bubble fluctuations is not likely to take place in defect CFTs with an AdS dual, although it might be possible if the defect supports a non-unitary theory.

  15. Differentiated muscles are mandatory for gas-filling of the Drosophila airway system

    Directory of Open Access Journals (Sweden)

    Yiwen Wang

    2015-12-01

    Full Text Available At the end of development, organs acquire functionality, thereby ensuring autonomy of an organism when it separates from its mother or a protective egg. In insects, respiratory competence starts when the tracheal system fills with gas just before hatching of the juvenile animal. Cellular and molecular mechanisms of this process are not fully understood. Analyses of the phenotype of Drosophila embryos with malformed muscles revealed that they fail to gas-fill their tracheal system. Indeed, we show that major regulators of muscle formation like Lame duck and Blown fuse are important, while factors involved in the development of subsets of muscles including cardiac and visceral muscles are dispensable for this process, suggesting that somatic muscles (or parts of them are essential to enable tracheal terminal differentiation. Based on our phenotypic data, we assume that somatic muscle defect severity correlates with the penetrance of the gas-filling phenotype. This argues that a limiting molecular or mechanical muscle-borne signal tunes tracheal differentiation. We think that in analogy to the function of smooth muscles in vertebrate lungs, a balance of physical forces between muscles and the elasticity of tracheal walls may be decisive for tracheal terminal differentiation in Drosophila.

  16. Determining casting defects in near-net shape casting aluminum parts by computed tomography

    Science.gov (United States)

    Li, Jiehua; Oberdorfer, Bernd; Habe, Daniel; Schumacher, Peter

    2018-03-01

    Three types of near-net shape casting aluminum parts were investigated by computed tomography to determine casting defects and evaluate quality. The first, second, and third parts were produced by low-pressure die casting (Al-12Si-0.8Cu-0.5Fe-0.9Mg-0.7Ni-0.2Zn alloy), die casting (A356, Al-7Si-0.3Mg), and semi-solid casting (A356, Al-7Si-0.3Mg), respectively. Unlike die casting (second part), low-pressure die casting (first part) significantly reduced the formation of casting defects (i.e., porosity) due to its smooth filling and solidification under pressure. No significant casting defect was observed in the third part, and this absence of defects indicates that semi-solid casting could produce high-quality near-net shape casting aluminum parts. Moreover, casting defects were mostly distributed along the eutectic grain boundaries. This finding reveals that refinement of eutectic grains is necessary to optimize the distribution of casting defects and reduce their size. This investigation demonstrated that computed tomography is an efficient method to determine casting defects in near-net shape casting aluminum parts.

  17. Periodontal Regenerative Therapy of Intrabony Defects Using Deproteinized Bovine Bone Mineral in Combination with Collagen Barrier Membrane: A Multicenter Prospective Case-Series Study.

    Science.gov (United States)

    Irokawa, Daisuke; Okubo, Nobuki; Nikaido, Masahiko; Shimizu, Hiroyasu; Konobu, Hiroyuki; Matsui, Tokuo; Fujita, Takahisa; Goto, Hiroaki; Takeuchi, Takahiro; Ishii, Yoshihito; Saito, Atsushi

    This multicenter prospective case series study aimed to evaluate the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) in the treatment of intrabony defects. A total of 36 nonsmoking patients with chronic periodontitis were recruited in five centers in Japan. All patients had at least one intrabony defect of ≥ 3 mm. The surgical procedures included access for debridement using a papilla preservation technique. Defects were filled with DBBM and covered with CB. Clinical evidence after 6 months supported the effectiveness of the combination therapy in the treatment of intrabony defects.

  18. Osteogenic capacity of nanocrystalline bone cement in a weight-bearing defect at the ovine tibial metaphysis.

    Science.gov (United States)

    Harms, Christoph; Helms, Kai; Taschner, Tibor; Stratos, Ioannis; Ignatius, Anita; Gerber, Thomas; Lenz, Solvig; Rammelt, Stefan; Vollmar, Brigitte; Mittlmeier, Thomas

    2012-01-01

    The synthetic material Nanobone(®) (hydroxyapatite nanocrystallines embedded in a porous silica gel matrix) was examined in vivo using a standardized bone defect model in the ovine tibial metaphysis. A standardized 6 × 12 × 24-mm bone defect was created below the articular surface of the medial tibia condyles on both hind legs of 18 adult sheep. The defect on the right side was filled with Nanobone(®), while the defect on the contralateral side was left empty. The tibial heads of six sheep were analyzed after 6, 12, and 26 weeks each. The histological and radiological analysis of the defect on the control side did not reveal any bone formation after the total of 26 weeks. In contrast, the microcomputed tomography analysis of the defect filled with Nanobone(®) showed a 55%, 72%, and 74% volume fraction of structures with bone density after 6, 12, and 26 weeks, respectively. Quantitative histomorphological analysis after 6, and 12 weeks revealed an osteoneogenesis of 22%, and 36%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity. Nanobone(®) appears to be a highly potent bone substitute material with osteoconductive properties in a loaded large animal defect model, supporting the potential use of Nanobone(®) also in humans.

  19. The Defect Induced Mix Experiment (DIME) for NIF

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Mark J [Los Alamos National Laboratory; Bradley, Paul A [Los Alamos National Laboratory; Cobble, James A [Los Alamos National Laboratory; Hakel, Peter [Los Alamos National Laboratory; Hsu, Scott C [Los Alamos National Laboratory; Krasheninnikova, Natalia S [Los Alamos National Laboratory; Kyrala, George A [Los Alamos National Laboratory; Murphy, Thomas J [Los Alamos National Laboratory; Obrey, Kimberly A [Los Alamos National Laboratory; Shah, Rahul C [Los Alamos National Laboratory; Tregillis, Ian L [Los Alamos National Laboratory

    2012-06-18

    LANL will perform two Defect Induced Mix Experiment (DIME) implosion campaigns on NIF in July and September, 2012. This presentation describes the goals for these shots and the experimental configuration and diagnostic set up to collect the appropriate data. The first two-shot campaign will focus on executing polar direct drive (PDD) implosions of plastic CH capsules filled with deuterium gas. Gas filling will be performed through a fill tube at target chamber center. A vanadium backligher foil will provide x-rays to radiograph the last half of the implosion to compare the implosion trajectory with modeling predictions. An equatorial groove in one of the capsules will be present to determine its effect on implosion dynamics. The second DIME campaign will commission and use a spectral imager (MMI) to examine the evolution of thin capsule layers doped with either Ge or Ga at 1.85%. Spectral line emission from these layers will quantify the mix width at the inner shell radius and near an equatorial groove feature.

  20. Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT

    DEFF Research Database (Denmark)

    Møller, L; Wenzel, A; Wegge-Larsen, AM

    2013-01-01

    Abstract Objective. The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic...... gutta-percha. Furthermore, the obturation time for the two techniques was evaluated. Materials and methods. Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling...... technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross...

  1. Filled aperture concepts for the Terrestrial Planet Finder

    Science.gov (United States)

    Ridgway, Stephen T.

    2003-02-01

    Filled aperture telescopes can deliver a real, high Strehl image which is well suited for discrimination of faint planets in the vicinity of bright stars and against an extended exo-zodiacal light. A filled aperture offers a rich variety of PSF control and diffraction suppression techniques. Filled apertures are under consideration for a wide spectral range, including visible and thermal-IR, each of which offers a significant selection of biomarker molecular bands. A filled aperture visible TPF may be simpler in several respects than a thermal-IR nuller. The required aperture size (or baseline) is much smaller, and no cryogenic systems are required. A filled aperture TPF would look and act like a normal telescope - vendors and users alike would be comfortable with its design and operation. Filled aperture telescopes pose significant challenges in production of large primary mirrors, and in very stringent wavefront requirements. Stability of the wavefront control, and hence of the PSF, is a major issue for filled aperture systems. Several groups have concluded that these and other issues can be resolved, and that filled aperture options are competitive for a TPF precursor and/or for the full TPF mission. Ball, Boeing-SVS and TRW have recently returned architecture reviews on filled aperture TPF concepts. In this paper, I will review some of the major considerations underlying these filled aperture concepts, and suggest key issues in a TPF Buyers Guide.

  2. The bone regenerative effect of platelet-rich plasma in combination with an osteoconductive material in rat cranial defects.

    NARCIS (Netherlands)

    Plachokova, A.S.; Dolder, J. van den; Stoelinga, P.J.W.; Jansen, J.A.

    2006-01-01

    The effect of platelet-rich plasma (PRP) on bone regeneration, in combination with an osteoconductive material, was evaluated in a rat model. Cranial defects, 6.2 mm in diameter, were filled with HA/beta-TCP particles, HA/beta-TCP particles combined with PRP and HA/beta-TCP particles combined with

  3. Turbulent flow in a partially filled pipe

    Science.gov (United States)

    Ng, Henry; Cregan, Hope; Dodds, Jonathan; Poole, Robert; Dennis, David

    2017-11-01

    Turbulent flow in a pressure driven pipe running partially full has been investigated using high-speed 2D-3C Stereoscopic Particle Imaging Velocimetry. With the field-of-view spanning the entire pipe cross section we are able to reconstruct the full three dimensional quasi-instantaneous flow field by invoking Taylor's hypothesis. The measurements were carried out over a range of flow depths at a constant Reynolds number based on hydraulic diameter and bulk velocity of Re = 32 , 000 . In agreement with previous studies, the ``velocity dip'' phenomenon, whereby the location of the maximum streamwise velocity occurs below the free surface was observed. A mean flow secondary current is observed near the free surface with each of the counter-rotating rollers filling the half-width of the pipe. Unlike fully turbulent flow in a rectangular open channel or pressurized square duct flow where the secondary flow cells appear in pairs about a corner bisector, the mean secondary motion observed here manifests only as a single pair of vortices mirrored about the pipe vertical centreline.

  4. [Creep of amalgam fillings under clasp rests].

    Science.gov (United States)

    Borchers, L; Jung, T; West, M

    1989-10-01

    A clinically realistic experiment was set up to obtain information on the amount of vertical settling of clasp rests in amalgam restorations under functional loading. Mesioocclusal cavities were prepared in 16 lower molar specimens cast in brass. The cavities were filled with amalgam and provided with a mesial rest seat. A constant load of 100 N was applied via a simplified (experimental) saddle to a cobalt-chromium E-clasp cast to the saddle. The duration of the load corresponded to 160 days of clinical function. The chronological course of vertical displacement was analyzed mathematically. According to this result the process can be divided into three components: settling immediately upon load initiation (mean value 96 microns, transition creep (mean value 25 microns) and creep ata constant rate (mean value 15 microns). The mean overall vertical displacement of the rests was 136 microns, the maximum value 287 microns. These findings suggest that vertical settling of a clasp rest into its seat in an amalgam restoration may eventually result in significant changes in occlusion and may almost completely exhaust gingival resilience.

  5. Stability of a rolling fluid filled cylinder

    Science.gov (United States)

    Supekar, Rohit; Panchagnula, Mahesh

    2014-11-01

    We present an analytical solution to the problem of a fluid filled hollow cylindrical shell rolling on an inclined plane and then investigate the temporal stability of the system using linear stability analysis. We study the motion in two dimensions by analyzing the interaction between the fluid and the hollow cylinder. We show that the terminal state is associated with a constant acceleration, similar to a rigid body motion. Surprisingly, it is independent of the liquid viscosity and only depends on the ratio of the mass of the shell to the mass of the fluid contained (say, πm) . We analyze this base flow for its stability behavior using the frozen-time approximation. In this approach, we treat time as a parameter, the evolution of which causes the flow to transition from a stable to an unstable state. The point of neutral stability is noted and the spatial modes that show the maximum growth rate are analyzed. It was observed that instability sets in due to long wavelength axial waves, which are transverse to the flow direction. We find a critical Reynolds number based on the time to instability, above which the flow becomes unstable. Again, this Reynolds number appears to be only a function of πm.

  6. Defect branes as Alice strings

    International Nuclear Information System (INIS)

    Okada, Takashi; Sakatani, Yuho

    2015-01-01

    There exist various defect-brane backgrounds in supergravity theories which arise as the low energy limit of string theories. These backgrounds typically have non-trivial monodromies, and if we move a charged probe around the center of a defect, its charge will be changed by the action of the monodromy. During the process, the charge conservation law seems to be violated. In this paper, to resolve this puzzle, we examine a dynamics of the charge changing process and show that the missing charge of the probe is transferred to the background. We then explicitly construct the resultant background after the charge transfer process by utilizing dualities. This background has the same monodromy as the original defect brane, but has an additional charge which does not have any localized source. In the literature, such a charge without localized source is known to appear in the presence of Alice strings. We argue that defect branes can in fact be regarded as a realization of Alice strings in string theory and examine the charge transfer process from that perspective.

  7. Space Mapping and Defect Correction

    NARCIS (Netherlands)

    D. Echeverria (David); D.J.P. Lahaye (Domenico); P.W. Hemker (Piet); W.H.A. Schilders (Wil); H.A. van der Vorst (Henk); J. Rommes

    2008-01-01

    textabstractIn this chapter we present the principles of the space-mapping iteration techniques for the efficient solution of optimization problems. We also show how space-mapping optimization can be understood in the framework of defect correction. We observe the difference between the solution

  8. Space mapping and defect correction

    NARCIS (Netherlands)

    Echeverría, D.; Lahaye, D.; Hemker, P.W.; Schilders, W.H.A.; van der Vorst, H.A.; Rommes, J.

    2008-01-01

    In this chapter we present the principles of the space-mapping iteration techniques for the efficient solution of optimization problems. We also show how space-mapping optimization can be understood in the framework of defect correction. We observe the difference between the solution of the

  9. Grassman defectivity à la Terracini

    Directory of Open Access Journals (Sweden)

    Carla Dionisi

    2001-11-01

    Full Text Available This work is a modern rivisitation of a classical paper by nA. Terracini, going back to 1915, which suggests an elementary but powerful method for studying Grassmann defective varieties. In particular, the case of Veronese surfaces is completely understood, giving a positive answer to the so-called Waring problem for pairs of homogeneous polynomials in three variables.

  10. Defects and an unusual superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gor' kov, L.P.; Kalugin, P.A.

    1985-03-10

    If the superconducting gap in a pure material has zeros on an entire line along the Fermi surface, the state density is finite at epsilon = 0, beginning with the lowest defect concentrations. The splitting of the superconducting transition by impurities, U/sub 1-x/Th/sub x/Be/sub 13/ is discussed.

  11. Delamination initiated by a defect

    DEFF Research Database (Denmark)

    Biel, Anders; Toftegaard, Helmuth Langmaack

    2016-01-01

    Composite materials in wind turbines are mainly joined with adhesives. Adhesive joining is preferable since it distributes the stresses over a larger area. This study shows how a defect can influence the fracture behaviour of adhesively joined composite. Repeated experiments are performed using d...

  12. Ocular defects in cerebral palsy

    Directory of Open Access Journals (Sweden)

    Katoch Sabita

    2007-01-01

    Full Text Available There is a high prevalence of ocular defects in children with developmental disabilities. This study evaluated visual disability in a group of 200 cerebral palsy (CP patients and found that 68% of the children had significant visual morbidity. These findings emphasize the need for an early ocular examination in patients with CP.

  13. Nanocarbon: Defect Architectures and Properties

    Science.gov (United States)

    Vuong, Amanda

    The allotropes of carbon make its solid phases amongst the most diverse of any element. It can occur naturally as graphite and diamond, which have very different properties that make them suitable for a wide range of technological and commercial purposes. Recent developments in synthetic carbon include Highly Oriented Pyrolytic Graphite (HOPG) and nano-carbons, such as fullerenes, nanotubes and graphene. The main industrial application of bulk graphite is as an electrode material in steel production, but in purified nuclear graphite form, it is also used as a moderator in Advanced Gas-cooled Reactors across the United Kingdom. Both graphene and graphite are damaged over time when subjected to bombardment by electrons, neutrons or ions, and these have a wide range of effects on their physical and electrical properties, depending on the radiation flux and temperature. This research focuses on intrinsic defects in graphene and dimensional change in nuclear graphite. The method used here is computational chemistry, which complements physical experiments. Techniques used comprise of density functional theory (DFT) and molecular dynamics (MD), which are discussed in chapter 2 and chapter 3, respectively. The succeeding chapters describe the results of simulations performed to model defects in graphene and graphite. Chapter 4 presents the results of ab initio DFT calculations performed to investigate vacancy complexes that are formed in AA stacked bilayer graphene. In AB stacking, carbon atoms surrounding the lattice vacancies can form interlayer structures with sp2 bonding that are lower in energy compared to in-plane reconstructions. From the investigation of AA stacking, sp2 interlayer bonding of adjacent multivacancy defects in registry creates a type of stable sp2 bonded wormhole between the layers. Also, a new class of mezzanine structure characterised by sp3 interlayer bonding, resembling a prismatic vacancy loop has also been identified. The mezzanine, which is a

  14. Evaluation of myocardial fatty acid metabolism in the area of fill-in after thallium reinjection in patients with prior myocardial infarction

    International Nuclear Information System (INIS)

    Matsunari, Ichiro; Fujino, Susumu; Nishikawa, Takahiro; Ichiyanagi, Kenji; Taki, Junichi; Nakajima, Kenichi; Tonami, Norihisa; Hisada, Kinichi.

    1995-01-01

    Myocardial fatty acid utilization in the area with thallium fill-in after reinjection was assessed using 123 I-labeled 15-(p-iodophenyl) 3R, S-methylpentadecanoic acid (BMIPP). We studied 22 patients with prior myocardial infarction that revealed persistent defects on standard exercise-redistribution thallium imaging. In each patient, exercise-redistribution-reinjection thallium imaging was performed. Within two weeks of the thallium study, resting BMIPP imaging was performed 20 min after injection of BMIPP (148 MBq). Following qualitative analysis of the obtained thallium and BMIPP images, quantitative analysis was performed on the basis of relative regional uptake. Of 199 myocardial segments that showed persistent defects on exercise-redistribution images, 73 segments showed apparent fill-in on the reinjection images (fill-in positive), and the remaining 126 segments did not (fill-in negative). When BMIPP images were compared with the corresponding thallium reinjection images, reduced BMIPP uptake compared with thallium was frequently observed in the area of fill-in positive segments (65 of 73 segments, 89%). Quantitative analysis also showed decrease in BMIPP activity compared to thallium activity in the area of fill-in (49.7±16.1 vs. 65.8±16.0%, p<0.001). In contrast, only 24 of the 126 fill-in negative segments (19%) showed lower BMIPP uptake than thallium. These results suggest that impaired fatty acid utilization in the area of thallium new fill-in after reinjection already exists at resting condition. Thus, BMIPP imaging combined with exercise-redistribution-reinjection thallium imaging provides insights to understanding fatty acid utilization in ischemic but viable myocardium identified by thallium reinjection in patients with prior myocardial infarction. (author)

  15. Radiographic outcomes following treatment of intrabony defect with guided tissue regeneration in aggressive periodontitis.

    Science.gov (United States)

    Rakmanee, Thanasak; Griffiths, Gareth S; Auplish, Gita; Darbar, Ulpee; Petrie, Aviva; Olsen, Irwin; Donos, Nikolaos

    2016-07-01

    This study reports the radiographic analysis of a split-mouth, single-blinded, randomised controlled clinical trial which was designed to compare the efficacy of simplified papilla preservation flap (SPPF) with or without guided tissue regeneration (GTR) in patients with aggressive periodontitis (AgP). Eighteen AgP patients who had similar bilateral intrabony defects were treated. In all patients, the defects presented with radiographic evidence of an intrabony defect ≥3 and ≥5 mm of periodontal pocket depths (PPD). The surgical procedures included access for root instrumentation using SPPF alone (control) or, after debridement, a placement of resorbable GTR membrane (test). The standardised radiographic assessments were carried out at pre-surgical baseline and at 6 and 12 month post-surgery. Radiographic linear measurements and subtraction radiography were used as the method of analysis. Both treatments showed significant improvements in linear radiographic bone fill and defect resolution at 6 and 12 months, compared to baseline. The 12-month subtraction radiography at the GTR sites showed a significant improvement compared to the 6-month outcomes. Both therapies were effective in the treatment of intrabony defects in AgP patients although no significant differences between them could be demonstrated. The finding that the bone fill and resolution of the defect at the GTR sites were significantly higher at 12 months than at 6 months after treatment indicates that bone regeneration is still an ongoing process at 6 months post-surgery. Radiographic assessment of periodontal regeneration should be carried out at 12 months post-surgery in order to evaluate the complete healing of the bony defect.

  16. Ultrafast carrier dynamics in band edge and broad deep defect emission ZnSe nanowires

    Science.gov (United States)

    Othonos, Andreas; Lioudakis, Emmanouil; Philipose, U.; Ruda, Harry E.

    2007-12-01

    Ultrafast carrier dynamics of ZnSe nanowires grown under different growth conditions have been studied. Transient absorption measurements reveal the dependence of the competing effects of state filling and photoinduced absorption on the probed energy states. The relaxation of the photogenerated carriers occupying defect states in the stoichiometric and Se-rich samples are single exponentials with time constants of 3-4ps. State filling is the main contribution for probe energies below 1.85eV in the Zn-rich grown sample. This ultrafast carrier dynamics study provides an important insight into the role that intrinsic point defects play in the observed photoluminescence from ZnSe nanowires.

  17. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2014-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total demanded quantity the order fill rate would be the preferred service...... level measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...... extensions consider more general inventory control review policies with backordering, as well as some relations between service measures. A particularly important result in the paper concerns an alternative service measure, the customer order fill rate, and shows how this measure always exceeds the other two...

  18. Cytologic effects of primary tooth endodontic filling materials

    OpenAIRE

    Huang, Tsui-Hsien; Hung, Chi-Jr; Chen, Yi-Jyun; Chien, Hung-Chih; Kao, Chia-Tze

    2009-01-01

    Primary tooth endodontic filling materials should be bio-compatible with periodontal tissue. The purpose of this study was to analyze the biologic effects of different endodontic filling materials for primary teeth on a human osteosarcoma cell line (U2OS). Materials and methods: Experimental groups comprised different mixes of endodontic filling materials: zinc oxide-eugenol (ZnOE) + formocresol (FC); calcium hydroxide [Ca(OH)2] + FC; Ca(OH)2 + iodoform + deionized water; Ca(OH)2 + iodofor...

  19. Scour and fill in cobble-bedded streams

    OpenAIRE

    Carling, P.A.

    1982-01-01

    Scour and deposition have been measured in two small cobble-bedded upland streams, for two years. Grids of scour chains were inserted in the bed and relocated after the passage of individual hydrographs. Scour, fill and the area of the bed affected by these processes were recorded. The relationship between mean scour or fill and maximum scour or fill is assessed. In addition, the relationship between the depth of scour and the sediment transport rate as bedload is discussed briefly.

  20. Predicting internal red oak (Quercus rubra) log defect features using surface defect defect measurements

    Science.gov (United States)

    R. Edward. Thomas

    2013-01-01

    Determining the defects located within a log is crucial to understanding the tree/log resource for efficient processing. However, existing means of doing this non-destructively requires the use of expensive x-ray/CT (computerized tomography), MRI (magnetic resonance imaging), or microwave technology. These methods do not lend themselves to fast, efficient, and cost-...

  1. Relationship between voice coil fill factor and loudspeaker efficiency

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    -mode technology, can be designed to much lower loads. A thorough analysis of the loudspeaker efficiency is presented and its relation to the voice coil fill factor is described. In addition to this the influence of the driver’s mass ratio is investigated and it is found that high mass ratios is beneficial...... for the efficiency of drivers using high fill factor voice coils. Different voice coil winding strategies are described and their fill factors analysed. It is found that by lowering the nominal resistance of a voice coil, using rectangular wire, one can increase the fill factor. However a practical realization...

  2. Repair of periprosthetic pelvis defects with porous metal implants: a finite element study.

    Science.gov (United States)

    Levine, Danny L; Dharia, Mehul A; Siggelkow, Eik; Crowninshield, Roy D; Degroff, Dale A; Wentz, Douglas H

    2010-02-01

    Periacetabular osteolysis is a potentially difficult surgical challenge, which can often drive the choice of reconstruction methods used in revision hip replacement. For smaller defects, impaction of bone grafts may be sufficient, but larger defects can require filler materials that provide structural support in addition to filling a void. This study utilized finite element analysis (FEA) to examine the state of stress in periprosthetic pelvic bone when subjected to a stair-climbing load and in the presence of two simulated defects, to show the effect of implanting a defect repair implant fabricated from Trabecular Metal. Even a small medial bone defect showed a local stress elevation of 4x compared with that seen with an acetabular implant supported by intact periacetabular bone. Local bone stress was much greater (8x the baseline level) for a defect case in which the loss of bone superior to the acetabular implant permitted significant migration. FEA results showed that a repair of the small defect with a Trabecular Metal restrictor lowered periprosthetic bone stress to a level comparable to that in the case of a primary implant. For the larger defect case, the use of a Trabecular Metal augment provides structural stabilization and helps to restore the THR head center. However, stress in the adjacent periprosthetic bone is lower than that observed in the defect-free acetabulum. In the augment case, the load path between the femoral head and the pelvis now passes through the augment as the superior rim of the acetabulum has been replaced. Contact-induced stress in the augment is similar in magnitude to that seen in the superior rim of the baseline case, although the stress pattern in the augment is noticeably different from that in intact bone.

  3. Response of induced bone defects in horses to collagen matrix containing the human parathyroid hormone gene.

    Science.gov (United States)

    Backstrom, Kristin C; Bertone, Alicia L; Wisner, Erik R; Weisbrode, Stephen E

    2004-09-01

    To determine whether human parathyroid hormone (hPTH) gene in collagen matrix could safely promote bone formation in diaphyseal or subchondral bones of horses. 8 clinically normal adult horses. Amount, rate, and quality of bone healing for 13 weeks were determined by use of radiography, quantitative computed tomography, and histomorphometric analysis. Diaphyseal cortex and subchondral bone defects of metacarpi were filled with hPTH(1-34) gene-activated matrix (GAM) or remained untreated. Joints were assessed on the basis of circumference, synovial fluid analysis, pain on flexion, lameness, and gross and histologic examination. Bone volume index was greater for cortical defects treated with hPTH(1-34) GAM, compared with untreated defects. Bone production in cortical defects treated with hPTH(1-34) GAM positively correlated with native bone formation in untreated defects. In contrast, less bone was detected in hPTH(1-34) GAM-treated subchondral bone defects, compared with untreated defects, and histology confirmed poorer healing and residual collagen sponge. Use of hPTH(1-34) GAM induced greater total bone, specifically periosteal bone, after 13 weeks of healing in cortical defects of horses. The hPTH(1-34) GAM impeded healing of subchondral bone but was biocompatible with joint tissues. Promotion of periosteal bone formation may be beneficial for healing of cortical fractures in horses, but the delay in onset of bone formation may negate benefits. The hPTH(1-34) GAM used in this study should not be placed in articular subchondral bone defects, but contact with articular surfaces is unlikely to cause short-term adverse effects.

  4. Charged Semiconductor Defects Structure, Thermodynamics and Diffusion

    CERN Document Server

    Seebauer, Edmund G

    2009-01-01

    The technologically useful properties of a solid often depend upon the types and concentrations of the defects it contains. Not surprisingly, defects in semiconductors have been studied for many years, in many cases with a view towards controlling their behavior through various forms of "defect engineering." For example, in the bulk, charging significantly affects the total concentration of defects that are available to mediate phenomena such as solid-state diffusion. Surface defects play an important role in mediating surface mass transport during high temperature processing steps such as epitaxial film deposition, diffusional smoothing in reflow, and nanostructure formation in memory device fabrication. Charged Semiconductor Defects details the current state of knowledge regarding the properties of the ionized defects that can affect the behavior of advanced transistors, photo-active devices, catalysts, and sensors. Features: Group IV, III-V, and oxide semiconductors; Intrinsic and extrinsic defects; and, P...

  5. Modeling defect trends for iterative development

    Science.gov (United States)

    Powell, J. D.; Spanguolo, J. N.

    2003-01-01

    The Employment of Defects (EoD) approach to measuring and analyzing defects seeks to identify and capture trends and phenomena that are critical to managing software quality in the iterative software development lifecycle at JPL.

  6. Defects of mitochondrial DNA replication.

    Science.gov (United States)

    Copeland, William C

    2014-09-01

    Mitochondrial DNA is replicated by DNA polymerase γ in concert with accessory proteins such as the mitochondrial DNA helicase, single-stranded DNA binding protein, topoisomerase, and initiating factors. Defects in mitochondrial DNA replication or nucleotide metabolism can cause mitochondrial genetic diseases due to mitochondrial DNA deletions, point mutations, or depletion, which ultimately cause loss of oxidative phosphorylation. These genetic diseases include mitochondrial DNA depletion syndromes such as Alpers or early infantile hepatocerebral syndromes, and mitochondrial DNA deletion disorders, such as progressive external ophthalmoplegia, ataxia-neuropathy, or mitochondrial neurogastrointestinal encephalomyopathy. This review focuses on our current knowledge of genetic defects of mitochondrial DNA replication (POLG, POLG2, C10orf2, and MGME1) that cause instability of mitochondrial DNA and mitochondrial disease. © The Author(s) 2014.

  7. Cooperation and Defection in Ghetto

    Science.gov (United States)

    Kułakowski, Krzysztof

    We consider ghetto as a community of people ruled against their will by an external power. Members of the community feel that their laws are broken. However, attempts to leave ghetto makes their situation worse. We discuss the relation of the ghetto inhabitants to the ruling power in context of their needs, organized according to the Maslow hierarchy. Decisions how to satisfy successive needs are undertaken in cooperation with or defection the ruling power. This issue allows to construct the tree of decisions and to adopt the pruning technique from the game theory. Dynamics of decisions can be described within the formalism of fundamental equations. The result is that the strategy of defection is stabilized by the estimated payoff.

  8. Extrinsic point defects in aluminum antimonide

    OpenAIRE

    Erhart, Paul; Åberg, Daniel; Lordi, Vincenzo

    2010-01-01

    We investigate thermodynamic and electronic properties of group IV (C, Si, Ge, Sn) and group VI (O, S, Se, Te) impurities as well as P and H in aluminum antimonide (AlSb) using first-principles calculations. To this end, we compute the formation energies of a broad range of possible defect configurations including defect complexes with the most important intrinsic defects. We also obtain relative scattering cross strengths for these defects to determine their impact on charge carrier mobility...

  9. Iatrogenic Urethral Defect Repairment: A Case Report

    Directory of Open Access Journals (Sweden)

    Ulas Fidan

    2013-10-01

    Full Text Available    Iatrogenic urethral defect is a complication that occurs after vaginal surgical procedures. Many surgical methods according to place of defect are described in case of injury of urethra. In this article, we reported the repairment of distal urethral defect with the help of greft taken from labia minor. This defect is made by the excision of the granulation tissue that occurred after chronic paraurethral  gland infection.

  10. Defect relaxation in disordered materials

    International Nuclear Information System (INIS)

    Crandell, R.S.

    1989-01-01

    Using an exponential distribution of activation barriers, annealing data for metastable effects in hydrogenated amorphous silicon, a-Si:H, are quantitatively explained. This includes the stretched exponential time dependence of annealing and a Meyer-Neldel rule for the annealing time constant. An exponential distribution of annealing energies arises because defects are frozen in during growth at high temperature. Mechanisms that lead to an exponential distribution of annealing energies are weak bond-breaking and charge trapping

  11. Neonatal septum transversum diaphragmatic defects

    International Nuclear Information System (INIS)

    Wesselhoeft, C.W. Jr.; DeLuca, F.G.

    1984-01-01

    Over 10 years, 8 infants required surgery for central diaphragmatic herniation. Contrast peritoneography and technetium-99m-sulfur colloid radionuclide scanning were the most definitive diagnostic aids. Associated anomalies included variations of the pentalogy of Cantrell. A midline gastroduodenal loop was found in two infants. Six infants are alive and well 6 months to 3 years postoperatively. An abdominal approach is preferred if there is an intestinal hernia, associated gastrointestinal anomalies, or if a bilateral defect is present

  12. Neonatal septum transversum diaphragmatic defects

    Energy Technology Data Exchange (ETDEWEB)

    Wesselhoeft, C.W. Jr.; DeLuca, F.G.

    1984-04-01

    Over 10 years, 8 infants required surgery for central diaphragmatic herniation. Contrast peritoneography and technetium-99m-sulfur colloid radionuclide scanning were the most definitive diagnostic aids. Associated anomalies included variations of the pentalogy of Cantrell. A midline gastroduodenal loop was found in two infants. Six infants are alive and well 6 months to 3 years postoperatively. An abdominal approach is preferred if there is an intestinal hernia, associated gastrointestinal anomalies, or if a bilateral defect is present.

  13. COMSOL Multiphysics Model for HLW Canister Filling

    Energy Technology Data Exchange (ETDEWEB)

    Kesterson, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-11

    The U.S. Department of Energy (DOE) is building a Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is being temporarily stored in 177 underground tanks. Efforts are being made to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product quality requirements. Wastes containing high concentrations of Al2O3 and Na2O can contribute to nepheline (generally NaAlSiO4) crystallization, which can sharply reduce the chemical durability of high level waste (HLW) glass. Nepheline crystallization can occur during slow cooling of the glass within the stainless steel canister. The purpose of this work was to develop a model that can be used to predict temperatures of the glass in a WTP HLW canister during filling and cooling. The intent of the model is to support scoping work in the laboratory. It is not intended to provide precise predictions of temperature profiles, but rather to provide a simplified representation of glass cooling profiles within a full scale, WTP HLW canister under various glass pouring rates. These data will be used to support laboratory studies for an improved understanding of the mechanisms of nepheline crystallization. The model was created using COMSOL Multiphysics, a commercially available software. The model results were compared to available experimental data, TRR-PLT-080, and were found to yield sufficient results for the scoping nature of the study. The simulated temperatures were within 60 ºC for the centerline, 0.0762m (3 inch) from centerline, and 0.2286m (9 inch) from centerline thermocouples once the thermocouples were covered with glass. The temperature difference between the experimental and simulated values reduced to 40 ºC, 4 hours after the thermocouple was covered, and down to 20 ºC, 6 hours after the thermocouple was covered

  14. Healing parameters in a rabbit partial tendon defect following tenocyte/biomaterial implantation.

    Science.gov (United States)

    Stoll, Christiane; John, Thilo; Conrad, Claudia; Lohan, Anke; Hondke, Sylvia; Ertel, Wolfgang; Kaps, Christian; Endres, Michaela; Sittinger, Michael; Ringe, Jochen; Schulze-Tanzil, G

    2011-07-01

    Although rabbits are commonly used as tendon repair model, interpretative tools are divergent and comprehensive scoring systems are lacking. Hence, the aim was to develop a multifaceted scoring system to characterize healing in a partial Achilles tendon defect model. A 3 mm diameter defect was created in the midsubstance of the medial M. gastrocnemius tendon, which remained untreated or was filled with a polyglycolic-acid (PGA) scaffold + fibrin and either left cell-free or seeded with Achilles tenocytes. After 6 and 12 weeks, tendon repair was assessed macroscopically and histologically using self-constructed scores. Macroscopical scoring revealed superior results in the tenocyte seeded PGA + fibrin group compared with the controls at both time points. Histology of all operated tendons after 6 weeks proved extracellular matrix (ECM) disorganization, hypercellularity and occurrence of irregular running elastic fibres with no significance between the groups. Some inflammation was associated with PGA implantation and increased sulphated proteoglycan deposition predominantly with the empty defects. After 12 weeks defect areas became hard to recognize and differences between groups, except for the increased sulphated proteoglycans content in the empty defects, were almost nullified. We describe a partial Achilles tendon defect model and versatile scoring tools applicable for characterizing biomaterial-supported tendon healing. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Effect of enamel matrix derivative (Emdogain) on bone defects in rabbit tibias.

    Science.gov (United States)

    Cornelini, Roberto; Scarano, Antonio; Piattelli, Maurizio; Andreana, Sebastiano; Covani, Ugo; Quaranta, Alessandro; Piattelli, Adriano

    2004-01-01

    The aim of this study was to assess the effect of an enamel matrix derivative (Emdogain, Biora, AB, Malmö, Sweden) on bone healing. Ten New Zealand rabbits, weighing about 2.5 kg, were used. One 8-mm bone defect was created in each tibia. The defect on the right leg was filled with Emdogain, whereas the defect on the opposite leg was left unfilled as control. A total of 20 defects were created. Five rabbits each were killed at 4 and 8 weeks with an overdose of Tanax. Block sections containing the defects were retrieved and the specimens processed for light microscopy examination. The slides were stained with acid and basic fuchsin and toluidine blue. Histologically, no differences were noted in both groups at each observation period; in the test group, remnants of the implanted Emdogain were not present at 4 weeks. Newly formed bone was detectable in both groups at all observation times. At 8 weeks, both groups showed mature bone, and in the test group the material implanted was not visible. No inflammatory cells were visible in both groups. In conclusion, our results indicate that Emdogain implanted in bone defects is fully resorbed after 4 to 8 weeks and does not adversely affect bone formation.

  16. Effects of LED phototherapy on bone defects grafted with MTA, bone morphogenetic proteins and guided bone regeneration: a Raman spectroscopic study.

    Science.gov (United States)

    Pinheiro, Antonio L B; Soares, Luiz G P; Cangussú, Maria Cristina T; Santos, Nicole R S; Barbosa, Artur Felipe S; Silveira Júnior, Landulfo

    2012-09-01

    We studied peaks of calcium hydroxyapatite (CHA) and protein and lipid CH groups in defects grafted with mineral trioxide aggregate (MTA) treated or not with LED irradiation, bone morphogenetic proteins and guided bone regeneration. A total of 90 rats were divided into ten groups each of which was subdivided into three subgroups (evaluated at 15, 21 and 30 days after surgery). Defects were irradiated with LED light (wavelength 850 ± 10 nm) at 48-h intervals for 15 days. Raman readings were taken at the surface of the defects. There were no statistically significant differences in the CHA peaks among the nonirradiated defects at any of the experimental time-points. On the other hand, there were significant differences between the defects filled with blood clot and the irradiated defects at all time-points (p LED light irradiation improves the deposition of CHA in healing bone grafted or not with MTA.

  17. Curvature-Controlled Topological Defects

    Directory of Open Access Journals (Sweden)

    Luka Mesarec

    2017-05-01

    Full Text Available Effectively, two-dimensional (2D closed films exhibiting in-plane orientational ordering (ordered shells might be instrumental for the realization of scaled crystals. In them, ordered shells are expected to play the role of atoms. Furthermore, topological defects (TDs within them would determine their valence. Namely, bonding among shells within an isotropic liquid matrix could be established via appropriate nano-binders (i.e., linkers which tend to be attached to the cores of TDs exploiting the defect core replacement mechanism. Consequently, by varying configurations of TDs one could nucleate growth of scaled crystals displaying different symmetries. For this purpose, it is of interest to develop a simple and robust mechanism via which one could control the position and number of TDs in such atoms. In this paper, we use a minimal mesoscopic model, where variational parameters are the 2D curvature tensor and the 2D orientational tensor order parameter. We demonstrate numerically the efficiency of the effective topological defect cancellation mechanism to predict positional assembling of TDs in ordered films characterized by spatially nonhomogeneous Gaussian curvature. Furthermore, we show how one could efficiently switch among qualitatively different structures by using a relative volume v of ordered shells, which represents a relatively simple naturally accessible control parameter.

  18. Reflection and transmission for conformal defects

    NARCIS (Netherlands)

    Quella, T.; Runkel, I.; Watts, G.M.T.

    2007-01-01

    Abstract. We consider conformal defects joining two conformal field theories along a line. We define two new quantities associated to such defects in terms of expectation values of the stress tensors and we propose them as measures of the reflectivity and transmissivity of the defect. Their

  19. Metastable and bistable defects in silicon

    International Nuclear Information System (INIS)

    Mukashev, Bulat N; Abdullin, Kh A; Gorelkinskii, Yurii V

    2000-01-01

    Existing data on the properties and structure of metastable and bistable defects in silicon are analyzed. Primary radiation-induced defects (vacancies, self-interstitial atoms, and Frenkel pairs), complexes of oxygen, carbon, hydrogen, and other impurity atoms and defects with negative correlation energy are considered. (reviews of topical problems)

  20. Prediction of maximum dry density of local granular fills | Worku ...

    African Journals Online (AJOL)

    The paper presents a relation. developed to predict maximum dry density (MDD) in terms of the solid density and the gradation coefficients that characterize the grain size distribution of locally employed granular fill materials. For this purpose, two geologically different soils commonly used as selected fill materials are ...

  1. The Effects of Iron Filling On Some Mechanical and Physical ...

    African Journals Online (AJOL)

    This research work was aimed at producing particleboard from sawdust (matrix) and iron filling (particulate) under the same conditions as ordinary particleboard produced from sawdust alone and their properties compared. Sawdust –iron fillings particleboards were produced using a sawdust of particle size 1.18mm and ...

  2. Microbiological studies on bacterial isolates from penicillins filling ...

    African Journals Online (AJOL)

    Aseptic processing is a critical method for the preparation of thermolabile sterile parenteral drug products. Sterile β-lactam antibiotics are extremely deactivated by heat, so the method of choice for their processing is through aseptic filling. The consequences of contamination on aseptically-filled products are harmful to the ...

  3. Optimization of foam-filled bitubal structures for crashworthiness criteria

    International Nuclear Information System (INIS)

    Zhang, Yong; Sun, Guangyong; Li, Guangyao; Luo, Zhen; Li, Qing

    2012-01-01

    Highlights: ► The paper aims to optimize foam-filled bitubal squared column for crashworthiness. ► It explores different formulations and configurations of design. ► The optimal foam-filled bitubal column is better than foam-filled monotubal column. ► The optimal foam-filled bitubal column is better than empty bitubal column. -- Abstract: Thin-walled structures have been widely used as key components in automobile and aerospace industry to improve the crashworthiness and safety of vehicles while maintaining overall light-weight. This paper aims to explore the design issue of thin-walled bitubal column structures filled with aluminum foam. As a relatively new filler material, aluminum foam can increase crashworthiness without sacrificing too much weight. To optimize crashworthiness of the foam-filled bitubal square column, the Kriging meta-modeling technique is adopted herein to formulate the objective and constraint functions. The genetic algorithm (GA) and Non-dominated Sorting Genetic Algorithm II (NSGA II) are used to seek the optimal solutions to the single and multiobjective optimization problems, respectively. To compare with other thin-walled configurations, the design optimization is also conducted for empty bitubal column and foam-filled monotubal column. The results demonstrate that the foam-filled bitubal configuration has more room to enhance the crashworthiness and can be an efficient energy absorber.

  4. Assessment of heavy metals concentration in soils around oil filling ...

    African Journals Online (AJOL)

    GREG

    Technology. Full Length Research Paper. Assessment of heavy metals concentration in soils around oil filling and service stations in the Tamale. Metropolis, Ghana ... anthropogenic source such as the oil filling activities, brake wear, tyres wear and corroded vehicles ... biologically essential and are introduced into aquatic.

  5. Simulation of mould filling process for composite skeleton castings

    Directory of Open Access Journals (Sweden)

    M. Dziuba

    2008-04-01

    Full Text Available In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of core by liquid metal at estability technological parameters.. Below the assumptions and results of the initial simulated calculations are presented. The total number of the nodes in the casting was 1920 and of the connectors was 5280 what gave filling of 100% for the nodes and 99,56% for the connectors in the results of the simulation. Together it resulted as 99,78 % of filling the volume of the casting. The nodes and connectors were filled up to the 30 level of the casting in the simulation. The all connectors were filled up to the 25 level of the casting in the simulation. Starting from the 25 level individual connectors at the side surface of the casting weren’t filled up. The connectors weren’t supplied by multi-level getting system. The differences of filling the levels are little (maximally 5 per cent.

  6. Effect of deformation and dielectric filling on electromagnetic ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    MS received 19 August 2001; revised 2 November 2002. Abstract. The effect of depression and protrusion of vertical walls and dielec- tric filling on electromagnetic propagation through x-band rectangular waveguides is studied using the finite element method. The effect of these deformations and dielectric filling on TE10, ...

  7. Using Habit Reversal to Decrease Filled Pauses in Public Speaking

    Science.gov (United States)

    Mancuso, Carolyn; Miltenberger, Raymond G.

    2016-01-01

    This study evaluated the effectiveness of simplified habit reversal in reducing filled pauses that occur during public speaking. Filled pauses consist of "uh," "um," or "er"; clicking sounds; and misuse of the word "like." After baseline, participants received habit reversal training that consisted of…

  8. Combination of platelet-rich plasma with degradable bioactive borate glass for segmental bone defect repair.

    Science.gov (United States)

    Zhang, Ya-Dong; Wang, Gang; Sun, Yan; Zhang, Chang-Qing

    2011-02-01

    Porous scaffold biomaterials may offer a clinical alternative to bone grafts; however, scaffolds alone are typically insufficient to heal large bone defects. Numerous studies have demonstrated that osteoinductive growth factor significantly improves bone repair. In this study, a strategy combining degradable bioactive borate glass (BG) scaffolds with platelet-rich plasma (PRP) was tested. The bone defect was filled with BG alone, BG combined with autologous PRP or left empty. Bone formation was analyzed at 4, 8 and 12 weeks using both histology and radiology. The PRP treated group yielded better bone formation than the pure BG scaffold as determined by both histology and microcomputer tomography after 12 weeks. In conclusion, PRP improved bone healing in a diaphyseal rabbit model on BG. The combination of PRP and BG may be an effective approach to repair critical defects.

  9. Supermicrosurgical reconstruction of knee defect using superior medial genicular perforator as a recipient vessel

    Directory of Open Access Journals (Sweden)

    Hoon Kim

    2014-09-01

    Full Text Available A 24-year-old male presented after being involved in a motorcycle accident and was found to have soft tissue defects of the knee with exposure of patella. Due to the severe injury from the popliteal fossa to the posterior aspects of the lower leg, repair with a free flap from anterolateral thigh perforator was planned instead of local calf muscle flap. Preoperative angiography was performed, and it showed that superior medial genicular perforator was patent compared with unreliable filling of the superior lateral genicular perforator. The soft tissue defect was repaired using the superior medial genicular perforator as the recipient vessel. This was performed by creating perforator to perforator anastomosis (supermicrosurgery. The flap survived successfully, and the patient was able to ambulate in a few weeks without serious complications. This case indicates that superior medial genicular perforator can be used as the recipient vessel for covering the soft tissue defects of the knee caused by blunt injury.

  10. Adipofascial plus cross-finger flap augment reconstructive options in thumb defects: A case report

    Directory of Open Access Journals (Sweden)

    Pradeoth Mukundan Korambayil

    2017-04-01

    Full Text Available Cross-finger flaps are a powerful tool in terms of soft tissue reconstruction for defects of the fingers and thumb. In conditions where the cause is based on to infection or inflammation, there is always doubt on the part of plastic surgeons with regards to skeletonizing the pedicle for ease of transfer. Here, we present a case of cross finger flap with inclusion of an adipofascial component for reconstruction of the thumb soft tissue defect. The adipofascial component helps in reducing donor site exposure to extensor expansion and helps by filling up the deficit in recipient defect. In the current study, we used a hyperbaric oxygen therapy as an adjunct during the treatment process. The results were satisfactory with no flap complications. [Hand Microsurg 2017; 6(1.000: 39-42

  11. Water balance of an earth fill built of organic clay

    Directory of Open Access Journals (Sweden)

    Birle Emanuel

    2016-01-01

    Full Text Available The paper presents investigations on the water balance of an earth fill built of organic clay in humid climate. As the organic soil used for the fill contains geogenetically elevated concentrations of arsenic, particular attention is paid on the seepage flow through the fill. The test fill is 5 m high, 30 m long and 25 m wide. The fill consists of the organic clay compacted at water contents wet and dry of Proctor Optimum covered by a drainage mat and a 60 cm thick top layer. For the determination of the water balance extensive measuring systems were installed. The seepage at the bottom measured so far was less than 2 % of the precipitation. The interflow in the drainage mat above the compacted organic clay was of similar magnitude. The estimated evapotranspiration reached approx. 84 % of the precipitation. According to these measurements the percolation is much lower than the percolation of many landfill covers in humid climates.

  12. Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

    KAUST Repository

    Fidiani, Elok

    2013-08-15

    Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

  13. Development of gap filling technique in HLW repository

    International Nuclear Information System (INIS)

    Nakashima, Hitoshi; Saito, Akira; Ishii, Takashi; Toguri, Satohito; Okihara, Mitsunobu; Iwasa, Kengo

    2016-01-01

    HLW is supposed to be disposed underground at depths more than 300 m in Japan. Buffer is an artificial barrier that controls radionuclides migrating into the groundwater. The buffer would be made of a natural swelling clay, bentonite. Construction technology for the buffer has been studied for many years, but studies for the gaps surrounding the buffer are little. The proper handling of the gaps is important for guaranteeing the functions of the buffer. In this paper, gap filling techniques using bentonite pellets have been developed in order to the gap having the same performance as the buffer. A new method for manufacturing high-density spherical pellets has been developed to fill the gap higher density ever reported. For the bentonite pellets, the filling performance and how to use were determined. And full-scale filling tests provided availability of the bentonite pellets and filling techniques. (author)

  14. Evaluation of a filling system for binary pediatric solutions.

    Science.gov (United States)

    Combeau, D; Rey, J B; Fontan, J E; Arnaud, P; Brion, F

    1998-02-01

    The aim of this study was to assess the use of an automatic filling system (Siframix M31 and M32 system) to prepare pediatric parenteral nutrition. Volumetric accuracy was measured for each siframix system loads cells (bottles during the filling operation modify the accuracy (p = 0.004 for 20 ml and p = 0.009 for 500 ml). A flushing operation is necessary to lower the risk of electrolytic pollution for the filling of little bags. The filling speed for each module was also measured (the maximal filling speed was five liters per minute). The Siframix system allows one to prepare pediatric parenteral nutrition bags when volumes are above 4 ml and with adapted source solutions in terms of concentration and conditioning volumes.

  15. Evaluation of reaction gap-filling accuracy by randomization.

    Science.gov (United States)

    Latendresse, Mario; Karp, Peter D

    2018-02-14

    Completion of genome-scale flux-balance models using computational reaction gap-filling is a widely used approach, but its accuracy is not well known. We report on computational experiments of reaction gap filling in which we generated degraded versions of the EcoCyc-20.0-GEM model by randomly removing flux-carrying reactions from a growing model. We gap-filled the degraded models and compared the resulting gap-filled models with the original model. Gap-filling was performed by the Pathway Tools MetaFlux software using its General Development Mode (GenDev) and its Fast Development Mode (FastDev). We explored 12 GenDev variants including two linear solvers (SCIP and CPLEX) for solving the Mixed Integer Linear Programming (MILP) problems for gap filling; three different sets of linear constraints were applied; and two MILP methods were implemented. We compared these 13 variants according to accuracy, speed, and amount of information returned to the user. We observed large variation among the performance of the 13 gap-filling variants. Although no variant was best in all dimensions, we found one variant that was fast, accurate, and returned more information to the user. Some gap-filling variants were inaccurate, producing solutions that were non-minimum or invalid (did not enable model growth). The best GenDev variant showed a best average precision of 87% and a best average recall of 61%. FastDev showed an average precision of 71% and an average recall of 59%. Thus, using the most accurate variant, approximately 13% of the gap-filled reactions were incorrect (were not the reactions removed from the model), and 39% of gap-filled reactions were not found, suggesting that curation is still an important aspect of metabolic-model development.

  16. Influence of dental filling material type on the concentration of interleukin 9 in the samples of gingival crevicular fluid.

    Science.gov (United States)

    Stefanović, Vladimir; Taso, Ervin; Petković-Ćurčin, Aleksandra; Đukić, Mirjana; Gardašević, Milka; Rakić, Mia; Xavier, Struillou; Jović, Milena; Miller, Karolina; Stanojević, Ivan; Vojvodić, Danilo

    2016-08-01

    Several cytokines and lymphokines (IL1β, ENA78, IL6, TNFα, IL8 and S100A8) are expressed during dental pulp inflammation. Analysis of gingival crevicu-lar fluid (GCF) offers a non-invasive means of studying gen-eral host response in oral cavity. Although GCF levels of various mediators could reflect the state of inflammation both in dental pulp and gingiva adjacent to a tooth, GCF samples of those without significant gingivitis could be inter-preted as reflection of pulpal process. The aim of this study was to investigate IL9 GCF values in patients with dental car-ies and to assess possible influence of various dental fillings materials on local IL9 production. The study group included 90 patients, aged 18–70, with inclusion and exclusion criteria in the prospective clinical study. Of the 6 types of material used for the restoration of prepared cavities, 3 were intended for temporary and 3 for definitive restora-tion. According to dental fillings weight, all the participants were divided into 3 groups: those with fillings lighter than 0.50 g, those with 0.50–1.00 g, and those with fillings heavier than 1.00 g. Samples were taken from gingival sulcus using the filter paper technique. Clinical parameters were deter-mined by bleeding index, plaque index (Silness-Lou, 0–3), gingival index (0–3), and gingival sulcus depth. Cytokine con-centrations were assessed using commercially available cy-tomix. According to the weight of dental fillings, there was a clear decreament trend of IL9 values meaning that dental defects greater than 1.00 g of dental filling were associated with lower GCF IL9 concentration. The IL9 val-ues correlated with the degree of gingival index and depth of gingival sulcus, being higher with more advanced gingivitis and more pronounced anatomical changes in the tooth edge. Different filling materials exerted various local IL9 responses. Zink polycarbonate cement and amalgam fillings induced a significant and long-lasting local IL9 decrement

  17. Influence of dental filling material type on the concentration of interleukin 9 in the samples of gingival crevicular fluid

    Directory of Open Access Journals (Sweden)

    Stefanović Vladimir

    2016-01-01

    Full Text Available Background/Aim. Several cytokines and lymphokines (IL1β, ENA78, IL6, TNFα, IL8 and S100A8 are expressed during dental pulp inflammation. Analysis of gingival crevicu-lar fluid (GCF offers a non-invasive means of studying gen-eral host response in oral cavity. Although GCF levels of various mediators could reflect the state of inflammation both in dental pulp and gingiva adjacent to a tooth, GCF samples of those without significant gingivitis could be inter-preted as reflection of pulpal process. The aim of this study was to investigate IL9 GCF values in patients with dental car-ies and to assess possible influence of various dental fillings materials on local IL9 production. Methods. The study group included 90 patients, aged 18–70, with inclusion and exclusion criteria in the prospective clinical study. Of the 6 types of material used for the restoration of prepared cavities, 3 were intended for temporary and 3 for definitive restora-tion. According to dental fillings weight, all the participants were divided into 3 groups: those with fillings lighter than 0.50 g, those with 0.50–1.00 g, and those with fillings heavier than 1.00 g. Samples were taken from gingival sulcus using the filter paper technique. Clinical parameters were deter-mined by bleeding index, plaque index (Silness-Lou, 0–3, gingival index (0–3, and gingival sulcus depth. Cytokine con-centrations were assessed using commercially available cy-tomix. Results. According to the weight of dental fillings, there was a clear decreament trend of IL9 values meaning that dental defects greater than 1.00 g of dental filling were associated with lower GCF IL9 concentration. The IL9 val-ues correlated with the degree of gingival index and depth of gingival sulcus, being higher with more advanced gingivitis and more pronounced anatomical changes in the tooth edge. Different filling materials exerted various local IL9 responses. Zink polycarbonate cement and amalgam fillings induced

  18. Ultraviolet light-irradiated photocrosslinkable chitosan hydrogel to prevent bone formation in both rat skull and fibula bone defects.

    Science.gov (United States)

    Tsuda, Yoshifumi; Hattori, Hidemi; Tanaka, Yoshihiro; Ishihara, Masayuki; Kishimoto, Satoko; Amako, Masatoshi; Arino, Hiroshi; Nemoto, Koichi

    2013-09-01

    In the field of orthopaedic surgery, an orthopaedic surgeon sometimes requires to suppress excessive bone formation, such as ectopic bone formation, ossifying myositis and radio-ulnar synostosis, etc. Ultraviolet (UV) light irradiation of a photocrosslinkable chitosan (Az-CH-LA) generates an insoluble hydrogel within 30 s. The purpose of this study was to evaluate the ability of the photocrosslinked chitosan hydrogel (PCH) to inhibit bone formation in an experimental model of bone defect. Rat calvarium and fibula were surgically injured and PCH was implanted into the resultant bone defects. The PCH implants significantly prevented bone formation in the bone defects during the 4 and 8 week observation periods. In the PCH-treated defects, fibrous tissues infiltrated by inflammatory cells were formed by day 7, completely filling the bone defects. In addition to these findings, expression of osteocalcin and runt-related gene 2 (RUNX2) mRNA, both markers of bone formation, was lower in the PCH-treated defects than in the controls. In contrast, collagen type 1α2 and α-smooth muscle actin (α-SMA) mRNA levels were significantly higher in the PCH-treated defects after 1 week. PCH stimulated the formation of fibrous tissue in bone defects while inhibiting bone formation. Thus, PCH might be a promising new therapeutic biomaterial for the prevention of bone formation in orthopaedic surgery. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Evaluation of Polyurethane Membrane as a Barrier in Treatment of Intrabony Defects

    Directory of Open Access Journals (Sweden)

    Haghighati F

    2000-05-01

    Full Text Available Clinical healing following guided tissue regeneration (GTR in intrabony pockets using a"npolyurethane membrane was compared to healing following gingival flap surgery (GFS."nTen patients with adult periodontitis and the presence of intrabony defects were selected. Oral hygenic"ntreatments were performed during a 4- weeks period prior to surgery."nOne intrabony defects on each patient was randomly chosen to be treated according to the guided tissue"nregeneration (GTR procedure. The other side received the control treatment GFS. Test group received"nthe GTP treatment including polyurethane membrane after reflecting the flap and curettage of defect."nHowever, flap surgery and curettage were done in control group."nThe patients were evaluated for changes in probing depth (PD, clinical attachment level (CAL,"nrecession changes in crestai resorting, and defect bone fill. Clinical examinations were performed again 6"nmonths post operatively."nThe average of (PD, (CAL and defect depth (DD before surgery in test group was 3.23, 13.87 and 7.3"nmm respectively and in control group was 3.1, 8.9, 7.4 mm. After 6 months the average of (PD, (CAL"nand (DD was 1.69, 1.68, 3.5 mm, respectively and in control group was 1.24, 1.09, and 2.90mm."nTest group and control group showed successful results in treatment of intrabony defects. Test group"nshowed better results than control."nNo significant difference was observed between two treatment procedures from the point of view of"npocket depth reduction, attachment gain, and recession."nThe bony fill and crestai resorption results suggest similar clinical potential of GTR procedures"ncompared to GFS in treatment of intrabony pocket. However, in order to gain future insight, larger"nsamples and longer observation periods should be evaluated.

  20. Selecting the best defect reduction methodology

    Energy Technology Data Exchange (ETDEWEB)

    Hinckley, C.M. [Sandia National Labs., Albuquerque, NM (United States); Barkan, P. [Stanford Univ., CA (United States)

    1994-04-01

    Defect rates less than 10 parts per million, unimaginable a few years ago, have become the standard of world-class quality. To reduce defects, companies are aggressively implementing various quality methodologies, such as Statistical Quality Control Motorola`s Six Sigma, or Shingo`s poka-yok. Although each quality methodology reduces defects, selection has been based on an intuitive sense without understanding their relative effectiveness in each application. A missing link in developing superior defect reduction strategies has been a lack of a general defect model that clarifies the unique focus of each method. Toward the goal of efficient defect reduction, we have developed an event tree which addresses a broad spectrum of quality factors and two defect sources, namely, error and variation. The Quality Control Tree (QCT) predictions are more consistent with production experience than obtained by the other methodologies considered independently. The QCT demonstrates that world-class defect rates cannot be achieved through focusing on a single defect source or quality control factor, a common weakness of many methodologies. We have shown that the most efficient defect reduction strategy depend on the relative strengths and weaknesses of each organization. The QCT can help each organization identify the most promising defect reduction opportunities for achieving its goals.

  1. Point defects and atomic transport in crystals

    International Nuclear Information System (INIS)

    Lidiard, A.B.

    1981-02-01

    There are two principle aspects to the theory of atomic transport in crystals as caused by the action of point defects, namely (1) the calculation of relevant properties of the point defects (energies and other thermodynamic characteristics of the different possible defects, activation energies and other mobility parameters) and (2) the statistical mechanics of assemblies of defects, both equilibrium and non-equilibrium assemblies. In the five lectures given here both these aspects are touched on. The first two lectures are concerned with the calculation of relevant point defect properties, particularly in ionic crystals. The first lecture is more general, the second is concerned particularly with some recent calculations of the free volumes of formation of defects in various ionic solids; these solve a rather long-standing problem in this area. The remaining three lectures are concerned with the kinetic theory of defects mainly in relaxation, drift and diffusion situations

  2. Yield impacting systematic defects search and management

    Science.gov (United States)

    Zhang, Jing; Xu, Qingxiu; Zhang, Xin; Zhao, Xing; Ning, Jay; Cheng, Guojie; Chen, Shijie; Zhang, Gary; Vikram, Abhishek; Su, Bo

    2012-03-01

    Despite great effort before design tapeout, there are still some pattern related systematic defects showing up in production, which impact product yield. Through various check points in the production life cycle endeavor is made to detect these defective patterns. It is seen that apart from the known defective patterns, slight variations of polygon sizes and shapes in the known defective patterns also cause yield loss. This complexity is further compounded when interactions among multiple process layers causes the defect. Normally the exact pattern matching techniques cannot detect these variations of the defective patterns. With the currently existing tools in the fab it is a challenge to define the 'sensitive patterns', which are arbitrary variations in the known 'defective patterns'. A design based approach has been successfully experimented on product wafers to detect yield impacting defects that greatly reduces the TAT for hotspot analysis and also provides optimized care area definition to enable high sensitivity wafer inspection. A novel Rule based pattern search technique developed by Anchor Semiconductor has been used to find sensitive patterns in the full chip design. This technique allows GUI based pattern search rule generation like, edge move or edge-to-edge distance range, so that any variations of a particular sensitive pattern can be captured and flagged. Especially the pattern rules involving multiple process layers, like M1-V1-M2, can be defined easily using this technique. Apart from using this novel pattern search technique, design signatures are also extracted around the defect locations in the wafer and used in defect classification. This enhanced defect classification greatly helps in determining most critical defects among the total defect population. The effectiveness of this technique has been established through design to defect correlation and SEM verification. In this paper we will report details of the design based experiments that

  3. Dental enamel defects, caries experience and oral health-related quality of life: a cohort study.

    Science.gov (United States)

    Arrow, P

    2017-06-01

    The impact of enamel defects of the first permanent molars on caries experience and child oral health-related quality of life was evaluated in a cohort study. Children who participated in a study of enamel defects of the first permanent molars 8 years earlier were invited for a follow-up assessment. Consenting children completed the Child Perception Questionnaire and the faces Modified Child Dental Anxiety Scale, and were examined by two calibrated examiners. ANOVA, Kruskal-Wallis, negative binomial and logistic regression were used for data analyses. One hundred and eleven children returned a completed questionnaire and 91 were clinically examined. Negative binomial regression found that oral health impacts were associated with gender (boys, risk ratio (RR) = 0.73, P = 0.03) and decayed, missing or filled permanent teeth (DMFT) (RR = 1.1, P = 0.04). The mean DMFT of children were sound (0.9, standard deviation (SD) = 1.4), diffuse defects (0.8, SD = 1.7), demarcated defects (1.5, SD = 1.4) and pit defects (1.3, SD = 2.3) (Kruskal-Wallis, P = 0.05). Logistic regression of first permanent molar caries found higher odds of caries experience with baseline primary tooth caries experience (odds ratio (OR) = 1.5, P = 0.01), the number of teeth affected by enamel defects (OR = 1.9, P = 0.05) and lower odds with the presence of diffuse enamel defects (OR = 0.1, P = 0.04). The presence of diffuse enamel defects was associated with lower odds of caries experience. © 2016 Australian Dental Association.

  4. Development of a design space and predictive statistical model for capsule filling of low-fill-weight inhalation products.

    Science.gov (United States)

    Faulhammer, E; Llusa, M; Wahl, P R; Paudel, A; Lawrence, S; Biserni, S; Calzolari, V; Khinast, J G

    2016-01-01

    The objectives of this study were to develop a predictive statistical model for low-fill-weight capsule filling of inhalation products with dosator nozzles via the quality by design (QbD) approach and based on that to create refined models that include quadratic terms for significant parameters. Various controllable process parameters and uncontrolled material attributes of 12 powders were initially screened using a linear model with partial least square (PLS) regression to determine their effect on the critical quality attributes (CQA; fill weight and weight variability). After identifying critical material attributes (CMAs) and critical process parameters (CPPs) that influenced the CQA, model refinement was performed to study if interactions or quadratic terms influence the model. Based on the assessment of the effects of the CPPs and CMAs on fill weight and weight variability for low-fill-weight inhalation products, we developed an excellent linear predictive model for fill weight (R(2 )= 0.96, Q(2 )= 0.96 for powders with good flow properties and R(2 )= 0.94, Q(2 )= 0.93 for cohesive powders) and a model that provides a good approximation of the fill weight variability for each powder group. We validated the model, established a design space for the performance of different types of inhalation grade lactose on low-fill weight capsule filling and successfully used the CMAs and CPPs to predict fill weight of powders that were not included in the development set.

  5. If Your Child Has a Heart Defect (For Parents)

    Science.gov (United States)

    ... ventricular septal defect , truncus arteriosus, atrioventricular septal defect, tetralogy of Fallot , and transposition of the great arteries) can be ... Care and Your Newborn Coarctation of the Aorta Tetralogy of Fallot Atrial Septal Defect Ventricular Septal Defect When Your ...

  6. Direct composite resin fillings versus amalgam fillings for permanent or adult posterior teeth.

    Science.gov (United States)

    Rasines Alcaraz, M Graciela; Veitz-Keenan, Analia; Sahrmann, Philipp; Schmidlin, Patrick Roger; Davis, Dell; Iheozor-Ejiofor, Zipporah

    2014-03-31

    Amalgam has been the traditional material for filling cavities in posterior teeth for the last 150 years and, due to its effectiveness and cost, amalgam is still the restorative material of choice in certain parts of the world. In recent times, however, there have been concerns over the use of amalgam restorations (fillings), relating to the mercury release in the body and the environmental impact following its disposal. Resin composites have become an esthetic alternative to amalgam restorations and there has been a remarkable improvement of its mechanical properties to restore posterior teeth.There is need to review new evidence comparing the effectiveness of both restorations. To examine the effects of direct composite resin fillings versus amalgam fillings for permanent posterior teeth, primarily on restoration failure. We searched the Cochrane Oral Health Group's Trials Register (to 22 October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 9), MEDLINE via OVID (1946 to 22 October 2013), EMBASE via OVID (1980 to 22 October 2013), and LILACs via BIREME Virtual Health Library (1980 to 22 October 2013). We applied no restrictions on language or date of publication when searching the electronic databases. We contacted manufacturers of dental materials to obtain any unpublished studies. Randomized controlled trials comparing dental resin composites with dental amalgams in permanent posterior teeth. We excluded studies having a follow-up period of less than three years. We used standard methodological procedures expected by The Cochrane Collaboration. Of the 2205 retrieved references, we included seven trials (10 articles) in the systematic review. Two trials were parallel group studies involving 1645 composite restorations and 1365 amalgam restorations (921 children) in the analysis. The other five trials were split-mouth studies involving 1620 composite restorations and 570 amalgam restorations in an unclear

  7. Packing defects into ordered structures

    DEFF Research Database (Denmark)

    Bechstein, R.; Kristoffersen, Henrik Høgh; Vilhelmsen, L.B.

    2012-01-01

    We have studied vicinal TiO2(110) surfaces by high-resolution scanning tunneling microscopy and density functional theory calculations. On TiO2 surfaces characterized by a high density of ⟨11̅ 1⟩ steps, scanning tunneling microscopy reveals a high density of oxygen-deficient strandlike adstructures....... With the help of density functional theory calculations we develop a complete structural model for the entire strand and demonstrate these adstructures to be more stable than an equivalent amount of bulk defects such as Ti interstitials. We argue that strands can form particularly easy on stepped surfaces...

  8. Numerical simulation and analysis of mould filling process in lost foam casting

    Directory of Open Access Journals (Sweden)

    Jiang Junxia

    2008-08-01

    Full Text Available In lost foam casting (LFC the foam pattern is the key criterion, and the filling process is crucial to ensure the high quality of the foam pattern. Filling which lacks uniformity and denseness will cause various defects and affect the surface quality of the casting. The infl uential factors of the fi lling process are realized in this research. Optimization of the fi lling process, enhancement of effi ciency, decrease of waste, etc., are obtained by the numerical simulation of the fi lling process using a computer.The equations governing the dense gas-solid two-phase flow are established, and the physical significance of each equation is discussed. The Euler/Lagrange numerical model is used to simulate the fluid dynamic characteristics of the dense two-phase fl ow during the mould fi lling process in lost foam casting. The experiments and numerical results showed that this method can be a very promising tool in the mould fi lling simulation of beads' movement.

  9. Biphasic β-TCP mixed with silicon increases bone formation in critical site defects in rabbit calvaria.

    Science.gov (United States)

    Calvo-Guirado, José Luis; Garces, Miguel; Delgado-Ruiz, Rafael Arcesio; Ramirez Fernandez, Maria P; Ferres-Amat, Eduard; Romanos, Georgios E

    2015-08-01

    The aim of this study was to assess the bone regeneration of critical size defects in rabbit calvarias filled with β-TCP doped with silicon. Twenty-one New Zealand rabbits were used in this study. Two critical size defects were created in the parietal bones. Three experimental groups were evaluated: Test A (HA/β-TCP granules alone), Test B (HA/β-TCP granules plus 3% silicon), Control (empty defect). The animals were sacrificed at 8 and 12 weeks. Evaluation was performed by μCT analysis and histomorphometry. μCT evaluation showed higher volume reduction in Test A group compared with Test B (P TCP plus 3% silicon increases bone formation in critical size defects in rabbit calvarias, and the incorporation of 3% silicon reduces the resorption rate of the HA/β-TCP granules. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Preparation and Characterization of Injectable Brushite Filled-Poly (Methyl Methacrylate Bone Cement

    Directory of Open Access Journals (Sweden)

    Lucas C. Rodriguez

    2014-09-01

    Full Text Available Powder-liquid poly (methyl methacrylate (PMMA bone cements are widely utilized for augmentation of bone fractures and fixation of orthopedic implants. These cements typically have an abundance of beneficial qualities, however their lack of bioactivity allows for continued development. To enhance osseointegration and bioactivity, calcium phosphate cements prepared with hydroxyapatite, brushite or tricalcium phosphates have been introduced with rather unsuccessful results due to increased cement viscosity, poor handling and reduced mechanical performance. This has limited the use of such cements in applications requiring delivery through small cannulas and in load bearing. The goal of this study is to design an alternative cement system that can better accommodate calcium-phosphate additives while preserving cement rheological properties and performance. In the present work, a number of brushite-filled two-solution bone cements were prepared and characterized by studying their complex viscosity-versus-test frequency, extrusion stress, clumping tendency during injection through a syringe, extent of fill of a machined void in cortical bone analog specimens, and compressive strength. The addition of brushite into the two-solution cement formulations investigated did not affect the pseudoplastic behavior and handling properties of the materials as demonstrated by rheological experiments. Extrusion stress was observed to vary with brushite concentration with values lower or in the range of control PMMA-based cements. The materials were observed to completely fill pre-formed voids in bone analog specimens. Cement compressive strength was observed to decrease with increasing concentration of fillers; however, the materials exhibited high enough strength for consideration in load bearing applications. The results indicated that partially substituting the PMMA phase of the two-solution cement with brushite at a 40% by mass concentration provided the best

  11. Preparation and Characterization of Injectable Brushite Filled-Poly (Methyl Methacrylate) Bone Cement

    Science.gov (United States)

    Rodriguez, Lucas C.; Chari, Jonathan; Aghyarian, Shant; Gindri, Izabelle M.; Kosmopoulos, Victor; Rodrigues, Danieli C.

    2014-01-01

    Powder-liquid poly (methyl methacrylate) (PMMA) bone cements are widely utilized for augmentation of bone fractures and fixation of orthopedic implants. These cements typically have an abundance of beneficial qualities, however their lack of bioactivity allows for continued development. To enhance osseointegration and bioactivity, calcium phosphate cements prepared with hydroxyapatite, brushite or tricalcium phosphates have been introduced with rather unsuccessful results due to increased cement viscosity, poor handling and reduced mechanical performance. This has limited the use of such cements in applications requiring delivery through small cannulas and in load bearing. The goal of this study is to design an alternative cement system that can better accommodate calcium-phosphate additives while preserving cement rheological properties and performance. In the present work, a number of brushite-filled two-solution bone cements were prepared and characterized by studying their complex viscosity-versus-test frequency, extrusion stress, clumping tendency during injection through a syringe, extent of fill of a machined void in cortical bone analog specimens, and compressive strength. The addition of brushite into the two-solution cement formulations investigated did not affect the pseudoplastic behavior and handling properties of the materials as demonstrated by rheological experiments. Extrusion stress was observed to vary with brushite concentration with values lower or in the range of control PMMA-based cements. The materials were observed to completely fill pre-formed voids in bone analog specimens. Cement compressive strength was observed to decrease with increasing concentration of fillers; however, the materials exhibited high enough strength for consideration in load bearing applications. The results indicated that partially substituting the PMMA phase of the two-solution cement with brushite at a 40% by mass concentration provided the best combination of the

  12. Radio resource management using geometric water-filling

    CERN Document Server

    He, Peter; Zhou, Sheng; Niu, Zhisheng

    2014-01-01

    This brief introduces the fundamental theory and development of managing radio resources using a water-filling algorithm that can optimize system performance in wireless communication. Geometric Water-Filling (GWF) is a crucial underlying tool in emerging communication systems such as multiple input multiple output systems, cognitive radio systems, and green communication systems. Early chapters introduce emerging wireless technologies and provide a detailed analysis of water-filling. The brief investigates single user and multi-user issues of radio resource management, allocation of resources

  13. Dopants and defects in semiconductors

    CERN Document Server

    McCluskey, Matthew D

    2012-01-01

    "The book goes beyond the usual textbook in that it provides more specific examples of real-world defect physics … The book will be most useful for beginning graduate students in materials science. … an easy reading, broad introductory overview of the field …"-Materials Today, July-August 2012"… well written, with clear, lucid explanations …"-Chemistry World"The scientific development towards the method of controllable doping transformed the erratic and not reproducible family of semiconductor materials into the truly wonderful basis of modern microelectronics. This book tells the remarkable success story and I recommend it!"-Hans J. Queisser, Max-Planck-Institute, Stuttgart, Germany"McCluskey and Haller have written an outstanding modern guide to this field that will be useful to newcomers, and also to active researchers who want to broaden their horizons, as a means to learn the capabilities and limitations of the many techniques that are used in semiconductor-defect science."-Professor Michael J....

  14. Size and location of defects at the coupling interface affect lithotripter performance.

    Science.gov (United States)

    Li, Guangyan; Williams, James C; Pishchalnikov, Yuri A; Liu, Ziyue; McAteer, James A

    2012-12-01

    Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? In shock wave lithotripsy air pockets tend to get caught between the therapy head of the lithotripter and the skin of the patient. Defects at the coupling interface hinder the transmission of shock wave energy into the body, reducing the effectiveness of treatment. This in vitro study shows that ineffective coupling not only blocks the transmission of acoustic pulses but also alters the properties of shock waves involved in the mechanisms of stone breakage, with the effect dependent on the size and location of defects at the coupling interface. • To determine how the size and location of coupling defects caught between the therapy head of a lithotripter and the skin of a surrogate patient (i.e. the acoustic window of a test chamber) affect the features of shock waves responsible for stone breakage. • Model defects were placed in the coupling gel between the therapy head of a Dornier Compact-S electromagnetic lithotripter (Dornier MedTech, Kennesaw, GA, USA) and the Mylar (biaxially oriented polyethylene terephthalate) (DuPont Teijin Films, Chester, VA, USA) window of a water-filled coupling test system. • A fibre-optic probe hydrophone was used to measure acoustic pressures and map the lateral dimensions of the focal zone of the lithotripter. • The effect of coupling conditions on stone breakage was assessed using gypsum model stones. • Stone breakage decreased in proportion to the area of the coupling defect; a centrally located defect blocking only 18% of the transmission area reduced stone breakage by an average of almost 30%. • The effect on stone breakage was greater for defects located on-axis and decreased as the defect was moved laterally; an 18% defect located near the periphery of the coupling window (2.0 cm off-axis) reduced stone breakage by only ~15% compared to when coupling was completely unobstructed. • Defects centred

  15. Nonlinear Fabry-Perot filled with CS2 and nitrobenzene

    International Nuclear Information System (INIS)

    Bischofberger, T.; Shen, Y.R.

    1979-01-01

    We have studied the characteristics of nonlinear Fabry-Perot filled with Kerr liquids CS 2 and nitorbenzene and found excellent agreement between theory and experiment. The transient behavior due to cavity-field buildup is discussed

  16. 46 CFR 153.282 - Cargo filling lines.

    Science.gov (United States)

    2010-10-01

    ... BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Piping Systems and Cargo Handling Equipment § 153.282 Cargo filling lines. The discharge point of a cargo tank...

  17. Beeswax as dental filling on a neolithic human tooth.

    Directory of Open Access Journals (Sweden)

    Federico Bernardini

    Full Text Available Evidence of prehistoric dentistry has been limited to a few cases, the most ancient dating back to the Neolithic. Here we report a 6500-year-old human mandible from Slovenia whose left canine crown bears the traces of a filling with beeswax. The use of different analytical techniques, including synchrotron radiation computed micro-tomography (micro-CT, Accelerator Mass Spectrometry (AMS radiocarbon dating, Infrared (IR Spectroscopy and Scanning Electron Microscopy (SEM, has shown that the exposed area of dentine resulting from occlusal wear and the upper part of a vertical crack affecting enamel and dentin tissues were filled with beeswax shortly before or after the individual's death. If the filling was done when the person was still alive, the intervention was likely aimed to relieve tooth sensitivity derived from either exposed dentine and/or the pain resulting from chewing on a cracked tooth: this would provide the earliest known direct evidence of therapeutic-palliative dental filling.

  18. Beeswax as dental filling on a neolithic human tooth.

    Science.gov (United States)

    Bernardini, Federico; Tuniz, Claudio; Coppa, Alfredo; Mancini, Lucia; Dreossi, Diego; Eichert, Diane; Turco, Gianluca; Biasotto, Matteo; Terrasi, Filippo; De Cesare, Nicola; Hua, Quan; Levchenko, Vladimir

    2012-01-01

    Evidence of prehistoric dentistry has been limited to a few cases, the most ancient dating back to the Neolithic. Here we report a 6500-year-old human mandible from Slovenia whose left canine crown bears the traces of a filling with beeswax. The use of different analytical techniques, including synchrotron radiation computed micro-tomography (micro-CT), Accelerator Mass Spectrometry (AMS) radiocarbon dating, Infrared (IR) Spectroscopy and Scanning Electron Microscopy (SEM), has shown that the exposed area of dentine resulting from occlusal wear and the upper part of a vertical crack affecting enamel and dentin tissues were filled with beeswax shortly before or after the individual's death. If the filling was done when the person was still alive, the intervention was likely aimed to relieve tooth sensitivity derived from either exposed dentine and/or the pain resulting from chewing on a cracked tooth: this would provide the earliest known direct evidence of therapeutic-palliative dental filling.

  19. Is a three-dimensional-printed tooth filling possible?

    Directory of Open Access Journals (Sweden)

    Muhammet Kerim Ayar

    2016-01-01

    Full Text Available Introduction: Three-dimensional (3-D printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce treatment costs and technique-sensitivity of the placement of restorative material. The Hypothesis: Here, the hypothesis that a 3-D-printed tooth filling approach could be an alternative to traditional approaches to treatment of decayed teeth is proposed. Evaluation of the Hypothesis: The actual implementation of the 3-D-printed tooth filling technique in the practice of restorative dentistry was discussed in this manuscript.

  20. Endurance of Damping Properties of Foam-Filled Tubes

    Directory of Open Access Journals (Sweden)

    Matteo Strano

    2015-07-01

    Full Text Available The favorable energy-absorption properties of metal foams have been frequently proposed for damping or anti-crash applications. The aim of this paper is to investigate the endurance of these properties for composite structures, made by a metal or a hybrid metal-polymeric foam used as the core filling of a tubular metal case. The results of experimental tests are shown, run with two types of structures: 1 square steel tubes filled with aluminum or with hybrid aluminum-polymer foams; 2 round titanium tubes filled with aluminum foams. The paper shows that the damping properties of a foam-filled tube change (improve with the number of cycles, while all other dynamic properties are nearly constant. This result is very important for several potential applications where damping is crucial, e.g., for machine tools.

  1. Endurance of Damping Properties of Foam-Filled Tubes.

    Science.gov (United States)

    Strano, Matteo; Marra, Alessandro; Mussi, Valerio; Goletti, Massimo; Bocher, Philippe

    2015-07-07

    The favorable energy-absorption properties of metal foams have been frequently proposed for damping or anti-crash applications. The aim of this paper is to investigate the endurance of these properties for composite structures, made by a metal or a hybrid metal-polymeric foam used as the core filling of a tubular metal case. The results of experimental tests are shown, run with two types of structures: 1) square steel tubes filled with aluminum or with hybrid aluminum-polymer foams; 2) round titanium tubes filled with aluminum foams. The paper shows that the damping properties of a foam-filled tube change (improve) with the number of cycles, while all other dynamic properties are nearly constant. This result is very important for several potential applications where damping is crucial, e.g., for machine tools.

  2. 27 CFR 27.202 - Standards of fill.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Requirements for Liquor Bottles § 27.202 Standards of fill. Distilled spirits imported into the United States in containers of 1...

  3. The coupling vibration of fluid-filled carbon nanotubes

    International Nuclear Information System (INIS)

    Wang, X Y; Wang, X; Sheng, G G

    2007-01-01

    Carbon nanotubes (CNTs) have substantial promise as nanocontainers filled with fluid in their hollow cavity in nanotechnology. This paper reports the result of an investigation into the influence of internal fluid on the coupling vibration of fluid-filled CNTs. The coupling vibrational behaviour of fluid-filled CNTs under different supported ends, aspect ratio, surrounding elastic medium, mass density of the fluid and layer number is investigated. The results obtained describe the effect of end condition, aspect ratio, surrounding elastic medium, mass density of the fluid and layer number on the coupling natural frequencies. The new features of the coupling vibration of fluid-filled CNTs and some meaningful and interesting results in this paper are helpful for the application and design of nanostructures conveying fluid in which CNTs act as basic elements

  4. 3D integrated HYDRA simulations of hohlraums including fill tubes

    Science.gov (United States)

    Marinak, M. M.; Milovich, J.; Hammel, B. A.; Macphee, A. G.; Smalyuk, V. A.; Kerbel, G. D.; Sepke, S.; Patel, M. V.

    2017-10-01

    Measurements of fill tube perturbations from hydro growth radiography (HGR) experiments on the National Ignition Facility show spoke perturbations in the ablator radiating from the base of the tube. These correspond to the shadow of the 10 μm diameter glass fill tube cast by hot spots at early time. We present 3D integrated HYDRA simulations of these experiments which include the fill tube. Meshing techniques are described which were employed to resolve the fill tube structure and associated perturbations in the simulations. We examine the extent to which the specific illumination geometry necessary to accommodate a backlighter in the HGR experiment contributes to the spoke pattern. Simulations presented include high resolution calculations run on the Trinity machine operated by the Alliance for Computing at Extreme Scale (ACES) partnership. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  5. Vacuum filling of complex microchannels with liquid metal.

    Science.gov (United States)

    Lin, Yiliang; Gordon, Olivia; Khan, M Rashed; Vasquez, Neyanel; Genzer, Jan; Dickey, Michael D

    2017-09-12

    This paper describes the utilization of vacuum to fill complex microchannels with liquid metal. Microchannels filled with liquid metal are useful as conductors for soft and stretchable electronics, as well as for microfluidic components such as electrodes, antennas, pumps, or heaters. Liquid metals are often injected manually into the inlet of a microchannel using a syringe. Injection can only occur if displaced air in the channels has a pathway to escape, which is usually accomplished using outlets. The positive pressure (relative to atmosphere) needed to inject fluids can also cause leaks or delamination of the channels during injection. Here we show a simple and hands-free method to fill microchannels with liquid metal that addresses these issues. The process begins by covering a single inlet with liquid metal. Placing the entire structure in a vacuum chamber removes the air from the channels and the surrounding elastomer. Restoring atmospheric pressure in the chamber creates a positive pressure differential that pushes the metal into the channels. Experiments and a simple model of the filling process both suggest that the elastomeric channel walls absorb residual air displaced by the metal as it fills the channels. Thus, the metal can fill dead-ends with features as small as several microns and branched structures within seconds without the need for any outlets. The method can also fill completely serpentine microchannels up to a few meters in length. The ability to fill dense and complex geometries with liquid metal in this manner may enable broader application of liquid metals in electronic and microfluidic applications.

  6. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...... that the injection speed in one of the most influencing process parameters on the μIM process and on the μ-parts filling....

  7. Impact of Viscosity on Filling the Injection Mould Cavity

    Directory of Open Access Journals (Sweden)

    Satin Lukáš

    2016-09-01

    Full Text Available The aim of this paper is to look closer at the rheological properties of plastics and their impact on technology in the plastics processing industry. The paper focuses on the influence of viscosity of the material on filling the mould cavity. Four materials were tested with the settings of process parameters with different viscosity. Using simulation software of Moldex3D, we can see the effect of change in viscosity in the material to be filled.

  8. Method for filling a reactor with a catalyst

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a method for filling a reactor with a catalyst for the carbonylation of carbonylated compounds in the gas phase. According to said method, a SILP catalyst is covered with a filling agent which is liquid under normal conditions and is volatile under carbonylation reaction...... conditions, and a thus-treated catalyst is introduced into the reactor and the reactor is sealed....

  9. Mechanical behaviour of dental composite filling materials using digital holography

    OpenAIRE

    Monteiro, J.M.; Lopes, H.; Vaz, M.A.P.; Campos, J.C. Reis

    2010-01-01

    One of the most common clinical problems in dentistry is tooth decay. Among the dental filling materials used to repair tooth structure that has been destroyed by decay are dental amalgam and composite materials based on acrylics. Dental amalgam has been used by dentists for the past 150 years as a dental restorative material due to its low cost, ease of application, strength, durability, and bacteriostatic effects. However its safety as a filling material has been questioned due to th...

  10. Is a three-dimensional-printed tooth filling possible?

    OpenAIRE

    Muhammet Kerim Ayar

    2016-01-01

    Introduction: Three-dimensional (3-D) printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce ...

  11. Perception of risk from automobile safety defects.

    Science.gov (United States)

    Slovic, P; MacGregor, D; Kraus, N N

    1987-10-01

    Descriptions of safety engineering defects of the kind that compel automobile manufacturers to initiate a recall campaign were evaluated by individuals on a set of risk characteristic scales that included overall vehicle riskiness, manufacturer's ability to anticipate the defect, importance for vehicle operation, severity of consequences and likelihood of compliance with a recall notice. A factor analysis of the risk characteristics indicated that judgments could be summarized in terms of two composite scales, one representing the uncontrollability of the damage the safety defect might cause and the other representing the foreseeability of the defect by the manufacturer. Motor vehicle defects were found to be highly diverse in terms of the perceived qualities of their risks. Location of individual defects within the factor space was closely associated with perceived riskiness, perceived likelihood of purchasing another car from the same manufacturer, perceived likelihood of compliance with a recall notice, and actual compliance rates.

  12. Altering graphene line defect properties using chemistry

    Science.gov (United States)

    Vasudevan, Smitha; White, Carter; Gunlycke, Daniel

    2012-02-01

    First-principles calculations are presented of a fundamental topological line defect in graphene that was observed and reported in Nature Nanotech. 5, 326 (2010). These calculations show that atoms and smaller molecules can bind covalently to the surface in the vicinity of the graphene line defect. It is also shown that the chemistry at the line defect has a strong effect on its electronic and magnetic properties, e.g. the ferromagnetically aligned moments along the line defect can be quenched by some adsorbates. The strong effect of the adsorbates on the line defect properties can be understood by examining how these adsorbates affect the boundary-localized states in the vicinity of the Fermi level. We also expect that the line defect chemistry will significantly affect the scattering properties of incident low-energy particles approaching it from graphene.

  13. Automatic classification of defects in weld pipe

    International Nuclear Information System (INIS)

    Anuar Mikdad Muad; Mohd Ashhar Hj Khalid; Abdul Aziz Mohamad; Abu Bakar Mhd Ghazali; Abdul Razak Hamzah

    2000-01-01

    With the advancement of computer imaging technology, the image on hard radiographic film can be digitized and stored in a computer and the manual process of defect recognition and classification may be replace by the computer. In this paper a computerized method for automatic detection and classification of common defects in film radiography of weld pipe is described. The detection and classification processes consist of automatic selection of interest area on the image and then classify common defects using image processing and special algorithms. Analysis of the attributes of each defect such as area, size, shape and orientation are carried out by the feature analysis process. These attributes reveal the type of each defect. These methods of defect classification result in high success rate. Our experience showed that sharp film images produced better results

  14. The Effect of Brain-Derived Neurotrophic Factor on Periodontal Furcation Defects

    Science.gov (United States)

    Jimbo, Ryo; Tovar, Nick; Janal, Malvin N.; Mousa, Ramy; Marin, Charles; Yoo, Daniel; Teixeira, Hellen S.; Anchieta, Rodolfo B.; Bonfante, Estevam A.; Konishi, Akihiro; Takeda, Katsuhiro; Kurihara, Hidemi; Coelho, Paulo G.

    2014-01-01

    This study aimed to observe the regenerative effect of brain-derived neurotrophic factor (BDNF) in a non-human primate furcation defect model. Class II furcation defects were created in the first and second molars of 8 non-human primates to simulate a clinical situation. The defect was filled with either, Group A: BDNF (500 µg/ml) in high-molecular weight-hyaluronic acid (HMW-HA), Group B: BDNF (50 µg/ml) in HMW-HA, Group C: HMW-HA acid only, Group D: empty defect, or Group E: BDNF (500 µg/ml) in saline. The healing status for all groups was observed at different time-points with micro computed tomography. The animals were euthanized after 11 weeks, and the tooth-bone specimens were subjected to histologic processing. The results showed that all groups seemed to successfully regenerate the alveolar buccal bone, however, only Group A regenerated the entire periodontal tissue, i.e., alveolar bone, cementum and periodontal ligament. It is suggested that the use of BDNF in combination with a scaffold such as the hyaluronic acid in periodontal furcation defects may be an effective treatment option. PMID:24454754

  15. Octacalcium phosphate collagen composite facilitates bone regeneration of large mandibular bone defect in humans.

    Science.gov (United States)

    Kawai, Tadashi; Suzuki, Osamu; Matsui, Keiko; Tanuma, Yuji; Takahashi, Tetsu; Kamakura, Shinji

    2017-05-01

    Recently it was reported that the implantation of octacalcium phosphate (OCP) and collagen composite (OCP-collagen) was effective at promoting bone healing in small bone defects after cystectomy in humans. In addition, OCP-collagen promoted bone regeneration in a critical-sized bone defect of a rodent or canine model. In this study, OCP-collagen was implanted into a human mandibular bone defect with a longer axis of approximately 40 mm, which was diagnosed as a residual cyst with apical periodontitis. The amount of OCP-collagen implanted was about five times greater than the amounts implanted in previous clinical cases. Postoperative wound healing was satisfactory and no infection or allergic reactions occurred. The OCP-collagen-treated lesion was gradually filled with radio-opaque figures, and the alveolar region occupied the whole of the bone defect 12 months after implantation. This study suggests that OCP-collagen could be a useful bone substitute material for repairing large bone defects in humans that might not heal spontaneously. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Bone regeneration of osteoporotic vertevral body defects using PRP and gelatin β-TCP sponges.

    Science.gov (United States)

    Sakata, Munehiro; Tonomura, Hitoshi; Itsuji, Tomonori; Ishibashi, Hidenobu; Takatori, Ryota; Mikami, Yasuo; Nagae, Masateru; Matsuda, Ken-Ichi; Tabata, Yasuhiko; Tanaka, Masaki; Kubo, Toshikazu

    2017-12-22

    The objective of the present study was to investigate the effect of platelet-rich plasma (PRP) combined with gelatin β-tricalcium phosphate (β-TCP) sponge on bone generation in a lumbar vertebral body defect of ovariectomized rat. After creating critical size defects in the center of the anterior vertebral body, the defects were filled with the following materials: (1) no material (control group), (2) gelatin β-TCP sponge with PRP (PRP sponge group), and (3) gelatin β-TCP sponge with phosphate-buffered saline (PBS sponge group). Microcomputed tomography and histological evaluation were performed immediately after surgery and at 4, 8, and 12 weeks to assess bone regeneration. Biomechanical test was also performed at postoperative week 12. In the PRP sponge group, both imaging and histological examination showed that visible osteogenesis was first induced and additional growth of bone tissue was observed in the transplanted sponge, compared with the PBS sponge group. There was no negative effect of either PRP sponge or PBS sponge transplantation on bone tissue generation around the periphery of the defect. Biomechanical test showed increased stiffness of the affected vertebral bodies in the PRP sponge group. These results indicate that PRP-impregnated gelatin β-TCP sponge is effective for facilitating bone regeneration in lumbar vertebral bone defect under osteoporotic condition. PRP combined with gelatin β-TCP sponges could be potentially useful for developing a new approach to vertebroplasty for osteoporotic vertebral fracture.

  17. Diastolic filling in a physical model of obstructive hypertrophic cardiomyopathy

    Science.gov (United States)

    Schovanec, Joseph; Samaee, Milad; Lai, Hong Kuan; Santhanakrishnan, Arvind

    2015-11-01

    Hypertrophic Cardiomyopathy (HCM) is an inherited heart disease that affects as much as one in 500 individuals, and is the most common cause of sudden death in young athletes. The myocardium becomes abnormally thick in HCM and deforms the internal geometry of the left ventricle (LV). Previous studies have shown that a vortex is formed during diastolic filling, and further that the dilated LV morphology seen in systolic heart failure results in altering the filling vortex from elliptical to spherical shape. We have also previously shown that increasing LV wall stiffness decreases the filling vortex circulation. However, alterations to intraventricular filling fluid dynamics due to an obstructive LV morphology and locally elevated wall stiffness (in the hypertrophied region) have not been previously examined from a mechanistic standpoint. We conducted an experimental study using an idealized HCM physical model and compared the intraventricular flow fields obtained from 2D PIV to a baseline LV physical model with lower wall stiffness and anatomical geometry. The obstruction in the HCM model leads to earlier breakdown of the filling vortex as compared to the anatomical LV. Intraventricular filling in both models under increased heart rates will be discussed.

  18. Effects of powder flow properties on capsule filling weight uniformity.

    Science.gov (United States)

    Osorio, Juan G; Muzzio, Fernando J

    2013-09-01

    Filling capsules with the right amount of powder ingredients is an important quality parameter. The purpose of this study was to develop effective laboratory methods for characterizing flow properties of pharmaceutical powder blends and correlating such properties to weight variability in filled capsules. The methods used for powder flow characterization were bulk and tapped density, gravitational displacement rheometer (GDR) flow index, Freeman Technology V.4 (FT4) powder rheometer compressibility, FT4 basic flow energy (BFE), and cohesion parameters [cohesion, (C) and flow factor (ffc)] measured in a shear cell also using the FT4. Capsules were filled using an MG2-G140 continuous nozzle dosator capsule-filling machine. Powder flow properties were the most predominant factors affecting the weight and weight variability in the filled capsules. Results showed that the weight variability decreased with increasing bulk and tapped density, ffc and BFE, while the weight variability increased with increasing compressibility, cohesion and GDR flow index. Powder flow properties of the final blends were significantly correlated to the final capsule weight and weight variability of the filled capsules.

  19. Pelvic bioelectrical impedance measurements to detect rectal filling.

    Science.gov (United States)

    Ratani, R S; Yazaki, E; Maw, A; Pilot, M A; Rogers, J; Williams, N S

    1998-11-01

    Anorectal sensory deficits are an important cause of defecatory disorders and are also a reason for evacuatory difficulties in patients undergoing total anorectal reconstruction. A method to detect rectal filling would be beneficial in such patients. We have investigated the feasibility of detecting rectal filling in vitro and in vivo by measuring changes in pelvic impedance. In vitro, a model of the pelvis was constructed using a cylindrical plastic tank filled with an electrolyte solution (conductivity 3 mS cm(-1)). Conductive Visking tubing representing the rectum was suspended in the tank and incrementally filled with artificial faeces. An impedance meter detected changes in voltage on rectal filling when an alternating current of 2 mA was passed at eight frequencies (4.8 to 612 kHz). In vivo, changes in pelvic bioelectrical impedance upon retrograde and antegrade rectal filling with artificial faeces were evaluated in three pigs, four electrodes being implanted in the pelvis. Impedance measurements accurately detected 'rectal' volume changes in vitro (n = 10, p < 0.0001; Kruskal Wallis), but not in vivo (n = 68, p = 0.48; Kruskal Wallis). This was probably due to extreme sensitivity of the detecting device to movement, a problem that needs to be resolved before this technique could be used in man.

  20. Fluid dynamics following flow shut-off in bottle filling

    Science.gov (United States)

    Thete, Sumeet; Appathurai, Santosh; Gao, Haijing; Basaran, Osman

    2012-11-01

    Bottle filling is ubiquitous in industry. Examples include filling of bottles with shampoos and cleaners, engine oil and pharmaceuticals. In these examples, fluid flows out of a nozzle to fill bottles in an assembly line. Once the required volume of fluid has flowed out of the nozzle, the flow is shut off. However, an evolving fluid thread or string may remain suspended from the nozzle following flow shut-off and persist. This stringing phenomenon can be detrimental to a bottle filling operation because it can adversely affect line speed and filling accuracy by causing uncertainty in fill volume, product loss and undesirable marring of the bottles' exterior surfaces. The dynamics of stringing are studied numerically primarily by using the 1D, slender-jet approximation of the flow equations. A novel feature entails development and use of a new boundary condition downstream of the nozzle exit to expedite the computations. While the emphasis is on stringing of Newtonian fluids and use of 1D approximations, results will also be presented for situations where (a) the fluids are non-Newtonian and (b) the full set of equations are solved without invoking the 1D approximation. Phase diagrams will be presented that identify conditions for which stringing can be problematic.

  1. Intrinsic point defects in aluminum antimonide

    OpenAIRE

    Åberg, Daniel; Erhart, Paul; Williamson, Andrew J.; Lordi, Vincenzo

    2010-01-01

    Calculations within density functional theory on the basis of the local density approximation are carried out to study the properties of intrinsic point defects in aluminum antimonide. Special care is taken to address finite-size effects, band gap error, and symmetry reduction in the defect structures. The correction of the band gap is based on a set of GW calculations. The most important defects are identified to be the aluminum interstitial $Al_{i,Al}^{1+}$, the antimony antisites $Sb_{Al}^...

  2. Diffusional changes of defect structure in solids

    International Nuclear Information System (INIS)

    Lyubov, B.Ya.

    1982-01-01

    Some problems of the theory of vacancy and impurity atoms diffusion in structure heterogeneous solidsi connected with changes in their defect structure, are reviewed. Two aspects of changes in the defect structure are discussed: an unconcervative movement of dislocations and a growth of damage of material continuity. Analytical solution methods in the theory of diffusional changes of defect structure in solids are illustrated as applied to hydrogen corrosion in steels, sintering kinetics, thermal conductivity theory [ru

  3. Phosphorous–vacancy–oxygen defects in silicon

    KAUST Repository

    Wang, Hao

    2013-07-30

    Electronic structure calculations employing the hybrid functional approach are used to gain fundamental insight in the interaction of phosphorous with oxygen interstitials and vacancies in silicon. It recently has been proposed, based on a binding energy analysis, that phosphorous–vacancy–oxygen defects may form. In the present study we investigate the stability of this defect as a function of the Fermi energy for the possible charge states. Spin polarization is found to be essential for the charge neutral defect.

  4. Effects of mass defect in atomic clocks

    Science.gov (United States)

    Taichenachev, A. V.; Yudin, V. I.

    2018-01-01

    We consider some implications of the mass defect on the frequency of atomic transitions. We have found that some well-known frequency shifts (such as gravitational and quadratic Doppler shifts) can be interpreted as consequences of the mass defect, i.e., without the need for the concept of time dilation used in special and general relativity theories. Moreover, we show that the inclusion of the mass defect leads to previously unknown shifts for clocks based on trapped ions..

  5. Defect-Tolerant Monolayer Transition Metal Dichalcogenides

    DEFF Research Database (Denmark)

    Pandey, Mohnish; Rasmussen, Filip Anselm; Kuhar, Korina

    2016-01-01

    -principles investigation of defect tolerance in 29 monolayer transition metal dichalcogenides (TMDs) of interest for nanoscale optoelectronics. We find that the TMDs based on group VI and X metals form deep gap states upon creation of a chalcogen (S, Se, Te) vacancy, while the TMDs based on group IV metals form only...... shallow defect levels and are thus predicted to be defect-tolerant. Interestingly, all the defect sensitive TMDs have valence and conduction bands with a very similar orbital composition. This indicates a bonding/antibonding nature of the gap, which in turn suggests that dangling bonds will fall inside...

  6. Evaluation of various boluses in dose distribution for electron therapy of the chest wall with an inward defect

    Science.gov (United States)

    Mahdavi, Hoda; Jabbari, Keyvan; Roayaei, Mahnaz

    2016-01-01

    Delivering radiotherapy to the postmastectomy chest wall can be achieved using matched electron fields. Surgical defects of the chest wall change the dose distribution of electrons. In this study, the improvement of dose homogeneity using simple, nonconformal techniques of thermoplastic bolus application on a defect is evaluated. The proposed phantom design improves the capability of film dosimetry for obtaining dose profiles of a patient's anatomical condition. A modeled electron field of a patient with a postmastectomy inward surgical defect was planned. High energy electrons were delivered to the phantom in various settings, including no bolus, a bolus that filled the inward defect (PB0), a uniform thickness bolus of 5 mm (PB1), and two 5 mm boluses (PB2). A reduction of mean doses at the base of the defect was observed by any bolus application. PB0 increased the dose at central parts of the defect, reduced hot areas at the base of steep edges, and reduced dose to the lung and heart. Thermoplastic boluses that compensate a defect (PB0) increased the homogeneity of dose in a fixed depth from the surface; adversely, PB2 increased the dose heterogeneity. This study shows that it is practical to investigate dose homogeneity profiles inside a target volume for various techniques of electron therapy. PMID:27051169

  7. Effect of platelet-rich plasma combined with demineralised bone matrix on bone healing in rabbit ulnar defects.

    Science.gov (United States)

    Galanis, Vasilios; Fiska, Alice; Kapetanakis, Stylianos; Kazakos, Konstantinos; Demetriou, Thespis

    2017-09-01

    This study evaluates the effect of autologous platelet-rich plasma (PRP) combined with xenogeneic demineralised bone matrix (DBM) on bone healing of critical-size ulnar defects (2-2.5 times the ulnar diameter) in New Zealand White rabbits. Critical-size defects were created unilaterally in the ulna of 36 rabbits, while keeping the contralateral limb intact. They were divided into three groups. In Group A, the defect was filled with autologous PRP and in Group B, with autologous PRP combined with DBM; in Group C, the defect remained empty. The rabbits were euthanised 12 weeks postoperatively. Radiological, biomechanical and histological assessments were carried out and statistical analysis of the results was performed. Group B had significantly higher radiological and histological scores than Groups A and C. Defects in Group B showed significant new bone formation, whereas there was minimal or no new bone formation in Groups A and C. Only specimens in Group B showed macroscopic bone union. Biomechanical evaluation of the treated and intact contralateral limbs in Group B showed significant differences. In this study, statistically significant enhancement of bone healing was found in critical-size defects treated with PRP and DBM, as shown by radiological findings, gross assessment, and biomechanical and histopathological results. Defects in the two other groups remained unbridged. Therefore, PRP was effective only when it was used in combination with a bone graft. Copyright: © Singapore Medical Association

  8. Defect reduction through Lean methodology

    Science.gov (United States)

    Purdy, Kathleen; Kindt, Louis; Densmore, Jim; Benson, Craig; Zhou, Nancy; Leonard, John; Whiteside, Cynthia; Nolan, Robert; Shanks, David

    2010-09-01

    Lean manufacturing is a systematic method of identifying and eliminating waste. Use of Lean manufacturing techniques at the IBM photomask manufacturing facility has increased efficiency and productivity of the photomask process. Tools, such as, value stream mapping, 5S and structured problem solving are widely used today. In this paper we describe a step-by-step Lean technique used to systematically decrease defects resulting in reduced material costs, inspection costs and cycle time. The method used consists of an 8-step approach commonly referred to as the 8D problem solving process. This process allowed us to identify both prominent issues as well as more subtle problems requiring in depth investigation. The methodology used is flexible and can be applied to numerous situations. Advantages to Lean methodology are also discussed.

  9. Erratic Dislocations within Funnel Defects in AlN Templates for AlGaNEpitaxial Layer Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hawkridge, Michael E; Liliental-Weber, Zuzanna; Jin Kim, Hee; Choi, Suk; Yoo, Dongwon; Ryou, Jae-Hyun; Dupuis, Russel D

    2009-03-13

    We report our transmission electron microscopy observations of erraticdislocation behavior within funnel-like defects in the top of AlN templates filled withAlGaN from an overlying epitaxial layer. This dislocation behavior is observed inmaterial where phase separation is also observed. Several bare AlN templates wereexamined to determine the formation mechanism of the funnels. Our results suggest that they are formed prior to epitaxial layer deposition due to the presence of impuritiesduring template re-growth. We discuss the erratic dislocation behavior in relation to thepresence of the phase-separated material and the possible effects of these defects on the optoelectronic properties.

  10. New device for closure of muscular ventricular septal defects in a canine model.

    Science.gov (United States)

    Amin, Z; Gu, X; Berry, J M; Bass, J L; Titus, J L; Urness, M; Han, Y M; Amplatz, K

    1999-07-20

    Repair of muscular ventricular septal defects (MVSDs) has always been challenging to the surgeon. Long-term morbidity and mortality are significantly increased if the defects are closed via left ventriculotomy or if they are associated with other complex congenital anomalies. The purpose of this study was to close MVSDs with the Amplatz ventricular septal defect device. This device is constructed from 0.004-in nitinol wire mesh filled with polyester fibers. It is retrievable, repositionable, self-centering, and of low profile. MVSDs were created with the help of a sharp punch in 10 dogs. The location of the defects was anterior muscular (n=3), midmuscular (n=3), apical (n=3), and inlet muscular (n=1). The diameter of the defects ranged from 6 to 14 mm. All defects were closed in the catheterization laboratory. The device was placed with the help of transesophageal echocardiography and fluoroscopy. A 7F sheath was used to deploy the device from the right ventricular side in 8 and the left ventricular side in 2 dogs. Placement was successful in all animals. The complete closure rate was 30% (3/10) immediately after placement and 100% at 1-week follow-up. Pathological examination of the heart revealed complete endothelialization of the device in dogs killed after 3 months. The Amplatz ventricular septal defect device appears highly efficacious in closing MVSDs. The advantages include a small delivery sheath, complete retrievability before release, and the fact that it is self-centering and self-expanding, thereby making it an attractive option in smaller children.

  11. Paternal occupation and birth defects: findings from the National Birth Defects Prevention Study.

    NARCIS (Netherlands)

    Desrosiers, T.A.; Herring, A.H.; Shapira, S.K.; Hooiveld, M.; Luben, T.J.; Herdt-Losavio, M.L.; Lin, S.; Olshan, A.F.

    2012-01-01

    Objectives: Several epidemiological studies have suggested that certain paternal occupations may be associated with an increased prevalence of birth defects in offspring. Using data from the National Birth Defects Prevention Study, the authors investigated the association between paternal occupation

  12. Defining defect specifications to optimize photomask production and requalification

    Science.gov (United States)

    Fiekowsky, Peter

    2006-10-01

    Reducing defect repairs and accelerating defect analysis is becoming more important as the total cost of defect repairs on advanced masks increases. Photomask defect specs based on printability, as measured on AIMS microscopes has been used for years, but the fundamental defect spec is still the defect size, as measured on the photomask, requiring the repair of many unprintable defects. ADAS, the Automated Defect Analysis System from AVI is now available in most advanced mask shops. It makes the use of pure printability specs, or "Optimal Defect Specs" practical. This software uses advanced algorithms to eliminate false defects caused by approximations in the inspection algorithm, classify each defect, simulate each defect and disposition each defect based on its printability and location. This paper defines "optimal defect specs", explains why they are now practical and economic, gives a method of determining them and provides accuracy data.

  13. Cusp deflection, infraction and fracture in endodontically treated teeth filled with three temporary filling materials (in vitro

    Directory of Open Access Journals (Sweden)

    Ali Eskandarizade

    2015-12-01

    Full Text Available Aim: the aim of this study was to compare cusp deflection, infraction and fracture in teeth filled with three temporary filling materials. Materials & method: Forty five extracted human premolar teeth were chosen. After root canal therapy and mesio-occluso-distal cavity preparation, samples were randomly divided into three groups , each contained 15 teeth and filled with three temporary filling materials: Cavisol (Golchai-Iran, Coltosol F (Coltene,Swiss and Coltene (Ariadent,Iran. Teeth were kept in normal saline at room temperature and every day the intercuspal distance was measured under stereomicroscope for 20 days. Infractions as well as fractures were also noted. Data were analyzed in SPSS 17 using Repeated measurement ANOVA test to evaluate the intercuspal distance and expansion of each sample every day. Results: Intercuspal distance increased in all three groups but was significantly more in Coltosol F group. On the days 10 and 16 two teeth filled with Coltosol F had cusp fracture. Conclusion: Temporary filling materials have hygroscopic expansion and cause cusp deflection which may lead to cusp fracture, so it is recommended to use them in short period of time.

  14. GIS-Based Locational Analysis of Petrol Filling Stations in Kaduna

    African Journals Online (AJOL)

    Dogara Sanda Tah

    agencies should take appropriate measures to ensure that filling stations operators comply with the standards. ... petroleum products and filling station are the places were fuel are sold. It has been discovered that, petrol filling stations ... Field visit were made to all the filling stations, and coordinate of the filling stations were ...

  15. Recent developments in inorganically filled carbon nanotubes: successes and challenges

    Directory of Open Access Journals (Sweden)

    Ujjal K Gautam, Pedro M F J Costa, Yoshio Bando, Xiaosheng Fang, Liang Li, Masataka Imura and Dmitri Golberg

    2010-01-01

    Full Text Available Carbon nanotubes (CNTs are a unique class of nanomaterials that can be imagined as rolled graphene sheets. The inner hollow of a CNT provides an extremely small, one-dimensional space for storage of materials. In the last decade, enormous effort has been spent to produce filled CNTs that combine the properties of both the host CNT and the guest filling material. CNTs filled with various inorganic materials such as metals, alloys, semiconductors and insulators have been obtained using different synthesis approaches including capillary filling and chemical vapor deposition. Recently, several potential applications have emerged for these materials, such as the measurement of temperature at the nanoscale, nano-spot welding, and the storage and delivery of extremely small quantities of materials. A clear distinction between this class of materials and other nanostructures is the existence of an enormous interfacial area between the CNT and the filling matter. Theoretical investigations have shown that the lattice mismatch and strong exchange interaction of CNTs with the guest material across the interface should result in reordering of the guest crystal structure and passivation of the surface dangling bonds and thus yielding new and interesting physical properties. Despite preliminary successes, there remain many challenges in realizing applications of CNTs filled with inorganic materials, such as a comprehensive understanding of their growth and physical properties and control of their structural parameters. In this article, we overview research on filled CNT nanomaterials with special emphasis on recent progress and key achievements. We also discuss the future scope and the key challenges emerging out of a decade of intensive research on these fascinating materials.

  16. Optimal decentralized valley-filling charging strategy for electric vehicles

    International Nuclear Information System (INIS)

    Zhang, Kangkang; Xu, Liangfei; Ouyang, Minggao; Wang, Hewu; Lu, Languang; Li, Jianqiu; Li, Zhe

    2014-01-01

    Highlights: • An implementable charging strategy is developed for electric vehicles connected to a grid. • A two-dimensional pricing scheme is proposed to coordinate charging behaviors. • The strategy effectively works in decentralized way but achieves the systematic valley filling. • The strategy allows device-level charging autonomy, and does not require a bidirectional communication/control network. • The strategy can self-correct when confronted with adverse factors. - Abstract: Uncoordinated charging load of electric vehicles (EVs) increases the peak load of the power grid, thereby increasing the cost of electricity generation. The valley-filling charging scenario offers a cheaper alternative. This study proposes a novel decentralized valley-filling charging strategy, in which a day-ahead pricing scheme is designed by solving a minimum-cost optimization problem. The pricing scheme can be broadcasted to EV owners, and the individual charging behaviors can be indirectly coordinated. EV owners respond to the pricing scheme by autonomously optimizing their individual charge patterns. This device-level response induces a valley-filling effect in the grid at the system level. The proposed strategy offers three advantages: coordination (by the valley-filling effect), practicality (no requirement for a bidirectional communication/control network between the grid and EV owners), and autonomy (user control of EV charge patterns). The proposed strategy is validated in simulations of typical scenarios in Beijing, China. According to the results, the strategy (1) effectively achieves the valley-filling charging effect at 28% less generation cost than the uncoordinated charging strategy, (2) is robust to several potential affecters of the valley-filling effect, such as (system-level) inaccurate parameter estimation and (device-level) response capability and willingness (which cause less than 2% deviation in the minimal generation cost), and (3) is compatible with

  17. Curing profile of bulk-fill resin-based composites.

    Science.gov (United States)

    Li, Xin; Pongprueksa, Pong; Van Meerbeek, Bart; De Munck, Jan

    2015-06-01

    To evaluate the curing profile of bulk-fill resin-based composites (RBC) using micro-Raman spectroscopy (μRaman). Four bulk-fill RBCs were compared to a conventional RBC. RBC blocks were light-cured using a polywave LED light-curing unit. The 24-h degree of conversion (DC) was mapped along a longitudinal cross-section using μRaman. Curing profiles were constructed and 'effective' (>90% of maximum DC) curing parameters were calculated. A statistical linear mixed effects model was constructed to analyze the relative effect of the different curing parameters. Curing efficiency differed widely with the flowable bulk-fill RBCs presenting a significantly larger 'effective' curing area than the fibre-reinforced RBC, which on its turn revealed a significantly larger 'effective' curing area than the full-depth bulk-fill and conventional (control) RBC. A decrease in 'effective' curing depth within the light beam was found in the same order. Only the flowable bulk-fill RBCs were able to cure 'effectively' at a 4-mm depth for the whole specimen width (up to 4mm outside the light beam). All curing parameters were found to statistically influence the statistical model and thus the curing profile, except for the beam inhomogeneity (regarding the position of the 410-nm versus that of 470-nm LEDs) that did not significantly affect the model for all RBCs tested. Most of the bulk-fill RBCs could be cured up to at least a 4-mm depth, thereby validating the respective manufacturer's recommendations. According to the curing profiles, the orientation and position of the light guide is less critical for the bulk-fill RBCs than for the conventional RBC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Recent developments in inorganically filled carbon nanotubes: successes and challenges

    Science.gov (United States)

    Gautam, Ujjal K; Costa, Pedro M F J; Bando, Yoshio; Fang, Xiaosheng; Li, Liang; Imura, Masataka; Golberg, Dmitri

    2010-01-01

    Carbon nanotubes (CNTs) are a unique class of nanomaterials that can be imagined as rolled graphene sheets. The inner hollow of a CNT provides an extremely small, one-dimensional space for storage of materials. In the last decade, enormous effort has been spent to produce filled CNTs that combine the properties of both the host CNT and the guest filling material. CNTs filled with various inorganic materials such as metals, alloys, semiconductors and insulators have been obtained using different synthesis approaches including capillary filling and chemical vapor deposition. Recently, several potential applications have emerged for these materials, such as the measurement of temperature at the nanoscale, nano-spot welding, and the storage and delivery of extremely small quantities of materials. A clear distinction between this class of materials and other nanostructures is the existence of an enormous interfacial area between the CNT and the filling matter. Theoretical investigations have shown that the lattice mismatch and strong exchange interaction of CNTs with the guest material across the interface should result in reordering of the guest crystal structure and passivation of the surface dangling bonds and thus yielding new and interesting physical properties. Despite preliminary successes, there remain many challenges in realizing applications of CNTs filled with inorganic materials, such as a comprehensive understanding of their growth and physical properties and control of their structural parameters. In this article, we overview research on filled CNT nanomaterials with special emphasis on recent progress and key achievements. We also discuss the future scope and the key challenges emerging out of a decade of intensive research on these fascinating materials. PMID:27877358

  19. Classification and Methods of Shrinkage Defect Control

    Directory of Open Access Journals (Sweden)

    N. S. Larichev

    2016-01-01

    Full Text Available The objective is to put forward a proposal to divide the internal shrinkage defects into the dimensional levels according to defects of certain size and shape.The paper presents the terminology used to describe the internal shrinkage defects in the casting and shows its flaws. These include the lack of well-defined threshold size values and shape of defects. It is shown that in describing defects their sizes and shape are defined qualitatively rather than quantitatively. And it is noted that division of defects into pores and shells is based on the morphological characters.The paper notes that a distinct difference between defects is necessary because of different methods of their elimination from the casting body.The paper presents an overview of control methods to determine the defects of the shrinkage nature in castings. These are methods of destructive and non-destructive testing, such as Xrays, tomography, and metallography. The paper also shows advantages and disadvantages of the considered methods of control. Based on the control method capacities it offers to divide the shrinkage defects into the three dimensional levels.To estimate the shape of defects the paper suggests a new option, that is a shape criterion. By the example of the typical defects of each dimensional level are defined the threshold values of the shape criterion.The paper discusses the basic techniques to estimate the porosity and offers a relationship between the defects of different dimensional levels and a porosity score and percent. It shows that the transition from a dimensional level to another one is in line with not only increasing pore size, but also with a significant deterioration of the mechanical properties of castings.The main conclusions are as follows:1. At present, there is no single unambiguous classification of casting shrinkage defects in the technical literature.2. As follows from the analysis of the classifications of shrinkage defects, their

  20. Modeling the relationships among internal defect features and external Appalachian hardwood log defect indicators

    Science.gov (United States)

    R. Edward. Thomas

    2009-01-01

    As a hardwood tree grows and develops, surface defects such as branch stubs and wounds are overgrown. Evidence of these defects remain on the log surface for decades and in many instances for the life of the tree. As the tree grows the defect is encapsulated or grown over by new wood. During this process the appearance of the defect in the tree's bark changes. The...

  1. Acetabular defect reconstruction with impacted morsellized bone grafts or TCP/HA particles. A study on the mechanical stability of cemented cups in an artificial acetabulum model.

    NARCIS (Netherlands)

    Bolder, S.B.T.; Verdonschot, N.J.J.; Schreurs, B.W.; Buma, P.

    2002-01-01

    In revision surgery of the acetabulum bone defects can be filled with impacted human morsellized bone grafts. Because of a worldwide limited availability of human bone, alternatives are being considered. In this study we compared the initial stability of acetabular cups after reconstructing a

  2. Method and instrumentation for detection of rail defects, in particular rail top defects

    NARCIS (Netherlands)

    Li, Z.; Molodova, M.

    2011-01-01

    A method and instrumentation for detection of rail defects, in particular rail top defects, in a railway-track by measuring an axle box acceleration signal of a rail vehicle, wherein a longitudinal axle box acceleration signal is used as a measure to detect the occurrence of said rail defects, in

  3. Predicting internal white oak (Quercus alba) log defect features using surface defect indicator measurements

    Science.gov (United States)

    Ralph E. Thomas

    2012-01-01

    As hardwood trees grow and develop, surface defects such as limb stubs and wounds are overgrown and encapsulated into the tree. Evidence of these defects can remain on the tree's surface for decades and in many instances for the life of the tree. The location and severity of internal defects dictate the quality and value of products that can be obtained from logs...

  4. hWJECM-Derived Oriented Scaffolds with Autologous Chondrocytes for Rabbit Cartilage Defect Repairing.

    Science.gov (United States)

    Zhao, Peng; Liu, Shuyun; Bai, Yuhe; Lu, Shibi; Peng, Jiang; Zhang, Li; Huang, Jingxiang; Zhao, Bin; Xu, Wenjing; Guo, Quanyi

    2018-02-02

    Previously, we synthesized an articular cartilage extracellular matrix (ECM)-derived oriented scaffold for cartilage tissue engineering, which was biomimetic in terms of structure and biochemical composition. However, the limit resource of the cartilage-derived ECM is a hindrance for its application. In this study, we developed a new material for cartilage tissue engineering-human umbilical cord Wharton's jelly-derived ECM (hWJECM). The hWJECM has an abundant resource and similar biochemistry with cartilage ECM, and the use of it is not associated with ethical controversy. We adopted the method previously used in cartilage ECM-derived oriented scaffold preparation to generate the oriented hWJECM-derived scaffold, and the scaffold properties were tested in vitro and in vivo. The three-dimensional scaffold has a porous and well-oriented structure, with a mean pore diameter of ∼104 μm. Scanning electron microscopy and cell viability staining results demonstrated that the oriented scaffold has good biocompatibility and cell alignment. In addition, we used functional autologous chondrocytes to seed the hWJECM-derived oriented scaffold and tested the efficacy of the cell-scaffold constructs to repair the full-thickness articular cartilage defect in a rabbit model. Defects of 4 mm diameter were generated in the patellar grooves of the femurs of both knees and were implanted with chondrocyte-scaffold constructs (group A) or scaffolds alone (group B); rabbits with untreated defects were used as a control (group C). Six months after surgery, all defects in group A were filled completely with repaired tissue, and most of which were hyaline cartilage. In contrast, the defects in group B were filled partially with repaired tissue, and approximately half of these repaired tissues were hyaline cartilage. The defects in group C were only filled with fibrotic tissue. Histological grading score of group A was lower than those of groups B and C. Quantification of

  5. Direct comparison of current cell-based and cell-free approaches towards the repair of craniofacial bone defects - A preclinical study.

    Science.gov (United States)

    Corre, P; Merceron, C; Longis, J; Khonsari, R H; Pilet, P; Thi, T Ngo; Battaglia, S; Sourice, S; Masson, M; Sohier, J; Espitalier, F; Guicheux, J; Weiss, P

    2015-10-01

    For craniofacial bone defect repair, several alternatives to bone graft (BG) exist, including the combination of biphasic calcium phosphate (BCP) biomaterials with total bone marrow (TBM) and bone marrow-derived mesenchymal stromal cells (MSCs), or the use of growth factors like recombinant human bone morphogenic protein-2 (RhBMP-2) and various scaffolds. Therefore, clinicians might be unsure as to which approach will offer their patients the most benefit. Here, we aimed to compare different clinically relevant bone tissue engineering methods in an "all-in-one" study in rat calvarial defects. TBM, and MSCs committed or not, and cultured in two- or three-dimensions were mixed with BCP and implanted in bilateral parietal bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant de novo bone formation was observed in rhBMP-2 and BG groups, and in a lesser amount, when BCP biomaterials were mixed with TBM or committed MSCs cultured in three-dimensions. Due to the efficacy and safety of the TBM/BCP combination approach, we recommend this one-step procedure for further clinical investigation. For craniofacial repair, total bone marrow (BM) and BM mesenchymal stem cell (MSC)-based regenerative medicine have shown to be promising in alternative to bone grafting (BG). Therefore, clinicians might be unsure as to which approach will offer the most benefit. Here, BM and MSCs committed or not were mixed with calcium phosphate ceramics (CaP) and implanted in bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant bone formation was observed in rhBMP-2 and BG groups, and when CaP were mixed with BM or committed MSCs. Since the BM-based procedure does not require bone harvest or cell culture, but provides de novo bone formation, we recommend consideration of this strategy for craniofacial applications. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. 49 CFR 213.337 - Defective rails.

    Science.gov (United States)

    2010-10-01

    ..., due to incomplete penetration of the weld metal between the rail ends, lack of fusion between weld and... cracking. Weld defects may originate in the rail head, web, or base, and in some cases, cracks may progress... 49 Transportation 4 2010-10-01 2010-10-01 false Defective rails. 213.337 Section 213.337...

  7. 7 CFR 52.3761 - Defects.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Defects. 52.3761 Section 52.3761 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... to olives pitted along an axis other than the stem-flower axis. A defect is a unit where the angle of...

  8. 16 CFR 1115.4 - Defect.

    Science.gov (United States)

    2010-01-01

    ... defect exists. At a minimum, defect includes the dictionary or commonly accepted meaning of the word... appliance presents a shock hazard because, through a manufacturing error, its casing can be electrically... for home garages is advertised as activating when carbon monoxide fumes reach a dangerous level but...

  9. Birth defects in children with newborn encephalopathy

    NARCIS (Netherlands)

    Felix, JF; Badawi, N; Kurinczuk, JJ; Bower, C; Keogh, JM; Pemberton, PJ

    2000-01-01

    This study was designed to investigate birth defects found in association with newborn encephalopathy. All possible birth defects were ascertained in a population-based study of 276 term infants with moderate or severe encephalopathy and 564 unmatched term control infants. A strong association

  10. Simple intrinsic defects in InAs :

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter Andrew

    2013-03-01

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  11. Encephalocele and associated skull defects | Komolafe | West ...

    African Journals Online (AJOL)

    Encephalocele is a common congenital problem in the practice of Neurosurgery worldwide, with varying sizes of the underlying skull defects. This study was carried out to determine the size of the problem; to assess whether the skull defects are being under-managed or not; and also to determine those patients that will ...

  12. Unsound defect volume in hardwood pallet cants

    Science.gov (United States)

    Philip Araman; Matt Winn; Firoz Kabir; Xavier Torcheux; Guillaume Loizeaud

    2003-01-01

    A study was conducted to determine the percentage of unsound defect volume to sound/clear wood in pallet cants at selected sawmills in Virginia and West Virginia. Splits,wane, shake, holes, decay, unsound knots, bark pockets, and mechanical defects were all considered to be unsound. Data were collected from seven Appalachian area sawmills for four hardwood species: red...

  13. Interventricular communication in complete atrioventricular septal defect

    NARCIS (Netherlands)

    Suzuki, K.; Ho, S. Y.; Anderson, R. H.; Becker, A. E.; Neches, W. H.; Tatsuno, K.; Mimori, S.

    1998-01-01

    Little attention has been paid to whether the interventricular communication in complete atrioventricular septal defect is different beneath the superior and inferior bridging leaflets, a feature of obvious surgical significance. We searched for a defect under the bridging leaflets and examined the

  14. 9 CFR 91.30 - Defective fittings.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Defective fittings. 91.30 Section 91... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.30 Defective fittings. If previously used fittings aboard an ocean vessel are employed, any portion thereof found by the inspector to be...

  15. Failures and Defects in the Building Process

    DEFF Research Database (Denmark)

    Jørgensen, Kirsten

    2009-01-01

    Function failures, defects, mistakes and poor communication are major problems for the construction sector. As the empirical element in the research, a large construction site was observed from the very start to the very end and all failures and defects of a certain size were recorded and analysed...

  16. Indicators for Building Process without Final Defects -

    DEFF Research Database (Denmark)

    Jørgensen, Kirsten; Rasmussen, Grane Mikael Gregaard; Thuesen, Christian Langhoff

    2011-01-01

    This article introduces the preliminary data analysis, as well as the underlying theories and methods for identifying the indicators for building process without final defects. Since 2004, the Benchmark Centre for the Danish Construction Sector (BEC) has collected information about legal defects...

  17. Osteogenic capacity of nanocrystalline bone cement in a weight-bearing defect at the ovine tibial metaphysis

    Directory of Open Access Journals (Sweden)

    Mittlmeier T

    2012-06-01

    Full Text Available Christoph Harms,1 Kai Helms,1 Tibor Taschner,1 Ioannis Stratos,1 Anita Ignatius,5 Thomas Gerber,2 Solvig Lenz,3 Stefan Rammelt,6 Brigitte Vollmar,4 Thomas Mittlmeier11Department of Trauma and Reconstructive Surgery, 2Department for Materials Research and Nanostructures, Institute for Physics, 3Department of Oral and Maxillofacial Plastic Surgery, 4Institute for Experimental Surgery, University of Rostock, Rostock, 5Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, 6Clinic of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Dresden, GermanyAbstract: The synthetic material Nanobone® (hydroxyapatite nanocrystallines embedded in a porous silica gel matrix was examined in vivo using a standardized bone defect model in the ovine tibial metaphysis. A standardized 6 × 12 × 24-mm bone defect was created below the articular surface of the medial tibia condyles on both hind legs of 18 adult sheep. The defect on the right side was filled with Nanobone®, while the defect on the contralateral side was left empty. The tibial heads of six sheep were analyzed after 6, 12, and 26 weeks each. The histological and radiological analysis of the defect on the control side did not reveal any bone formation after the total of 26 weeks. In contrast, the microcomputed tomography analysis of the defect filled with Nanobone® showed a 55%, 72%, and 74% volume fraction of structures with bone density after 6, 12, and 26 weeks, respectively. Quantitative histomorphological analysis after 6, and 12 weeks revealed an osteoneogenesis of 22%, and 36%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity. Nanobone® appears to be a highly potent bone substitute material with osteoconductive properties in a loaded large animal defect model, supporting the potential use of Nanobone® also in

  18. Software development for Indus-1 bunch filling pattern measurement

    International Nuclear Information System (INIS)

    Yadav, Surendra; Holikatti, Anil C.; Puntambekar, T.A.

    2011-01-01

    Indus-1 is a 450 MeV synchrotron radiation source operational at RRCAT Indore. In Indus-1 storage ring, electrons are stored in two bunches. The distribution of beam current in these two bunches is termed as bunch filling pattern. In Indus-1, it is desirable to have symmetric bunch filling pattern for its optimum performance. This paper describes the development of software for bunch filling pattern measurement of Indus-1. This software measures the current distribution of the electron bunches circulating in the storage ring. To measure bunch currents wall current monitor (WCM) installed in the Indus-1 storage ring is used. Using a 500 MHz digital storage oscilloscope as a high-speed digitizer and online data processing by the developed software, measurement of online bunch filling pattern was achieved. This software has helped Indus operation crew to achieve desired bunch current symmetry in the Indus-1 storage ring. The software has the provision to store the online bunch current symmetry into a Microsoft-excel file which can be used for further analysis. Using this software, up to 99% bunch filling symmetry has been achieved by Indus operation crew. (author)

  19. Depth of cure of bulk-fill flowable composite resins.

    Science.gov (United States)

    Pedalino, Inaam; Hartup, Grant R; Vandewalle, Kraig S

    2015-01-01

    In recent years, manufacturers have introduced flowable composite resins that reportedly can be placed in increments of 4 mm or greater. The purpose of this study was to evaluate the depth of cure of bulk-fill flowable composite resins (SureFil SDR Flow, Grandio Flow, and Venus Bulk Fill) and a conventional flowable composite resin (Revolution Formula 2). Depth of cure was measured in terms of bottom-maximum Knoop hardness number (KHN) ratios and the International Organization for Standardization (ISO) 4049 scrape technique. Shades A2 and A3 of SureFil SDR Flow, Grandio Flow, and Revolution Formula 2 were tested. Venus Bulk Fill was tested in its only available shade (universal). Specimens in thicknesses of 2, 3, 4, 5, and 6 mm were polymerized for 20 or 40 seconds, and a hardness tester was used to determine the hardness ratios for each shade at each thickness. For the scraping technique, after specimens were exposed to the curing light, unpolymerized composite resin was removed with a plastic instrument, the polymerized composite was measured, and the length was divided by 2 per ISO guidelines. According to the KHN ratios and the scrape test, Venus Bulk Fill predictably exceeded the manufacturer's claim of a 4-mm depth of cure at both 20 and 40 seconds of curing time. The overall results for depth of cure showed that Venus Bulk Fill ≥ SureFil SDR Flow ≥ Grandio Flow ≥ Revolution Formula 2.

  20. Elution of monomer from different bulk fill dental composite resins.

    Science.gov (United States)

    Cebe, Mehmet Ata; Cebe, Fatma; Cengiz, Mehmet Fatih; Cetin, Ali Rıza; Arpag, Osman Fatih; Ozturk, Bora

    2015-07-01

    The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4mm thickness, 5mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5mL) at predefined time intervals:10m (T1), 1h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of pcomposites (pcomposite resins in all time periods and the amount of eluted monomers was increased with time. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  1. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2017-09-28

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE 00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

  2. Regenerative Treatment of Periodontal Intrabony Defects Using Autologous Dental Pulp Stem Cells: A 1-Year Follow-Up Case Series.

    Science.gov (United States)

    Aimetti, Mario; Ferrarotti, Francesco; Gamba, Mara Noemi; Giraudi, Marta; Romano, Federica

    The present case series aimed to explore the potential clinical benefits of the application of dental pulp stem cells (DPSCs) in the regenerative treatment of deep intrabony defects. A total of 11 isolated intrabony defects in 11 chronic periodontitis patients were accessed with a minimally invasive flap and filled with DPSCs loaded on a collagen sponge. A tooth requiring extraction for impaction or malpositioning was used as an autologous source for DPSCs. An average clinical attachment level gain of 4.7 ± 1.5 mm associated with a residual mean probing depth (PD) of 3.2 ± 0.9 mm and remarkable stability of the gingival margin was observed at 1 year. Complete pocket closure (PD < 3 mm) was achieved in 63.6% of the experimental sites. Clinical outcomes were supported by the radiographic analysis showing a bone fill of 3.6 ± 1.9 mm.

  3. Aging Mechanisms and Nondestructive Aging Indicator of Filled Cross-linked Polyethylene (XLPE) Exposed to Simultaneous Thermal and Gamma Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shuaishuai; Fifield, Leonard S.; Bowler, Nicola

    2018-04-11

    Aging mechanisms and a nondestructive aging indicator of filled cross-linked polyethylene (XLPE) cable insulation material used in nuclear power plants (NPPs) are studied. Using various material characterization techniques, likely candidates and functions for the main additives in a commercial filled-XLPE insulation material have been identified. These include decabromodiphenyl ether and Sb2O3 as flame retardants, ZnS as white pigment and polymerized 1,2-dihydro-2,2,4-trimethylquinoline as antioxidant. Gas chromatography-mass spectrometry, differential scanning calorimetry, oxidation induction time and measurements of dielectric loss tangent are utilized to monitor property changes as a function of thermal and radiation exposure of the cable material. Small-molecular-weight hydrocarbons are evolve with gamma radiation aging at 90 °C. The level of antioxidant decreases with aging by volatilization and chemical reaction with free radicals. Thermal aging at 90 °C for 25 days or less causes no observable change to the cross-linked polymer structure. Gamma radiation causes damage to crystalline polymer regions and introduces defects. Dielectric loss tangent is shown to be an effective and reliable nondestructive indicator of the aging severity of the filled-XLPE insulation material.

  4. Defective Reduction in Frozen Pie Manufacturing Process

    Science.gov (United States)

    Nooted, Oranuch; Tangjitsitcharoen, Somkiat

    2017-06-01

    The frozen pie production has a lot of defects resulting in high production cost. Failure mode and effect analysis (FMEA) technique has been applied to improve the frozen pie process. Pareto chart is also used to determine the major defects of frozen pie. There are 3 main processes that cause the defects which are the 1st freezing to glazing process, the forming process, and the folding process. The Risk Priority Number (RPN) obtained from FMEA is analyzed to reduce the defects. If RPN of each cause exceeds 45, the process will be considered to be improved and selected for the corrective and preventive actions. The results showed that RPN values decreased after the correction. Therefore, the implementation of FMEA technique can help to improve the performance of frozen pie process and reduce the defects approximately 51.9%.

  5. Tritium releases, birth defects and infant deaths

    International Nuclear Information System (INIS)

    1991-01-01

    The AECB has published a report 'Tritium releases from the Pickering Nuclear Generating Station and Birth Defects and Infant Mortality in Nearby Communities 1971-1988' (report number INFO-0401). This presents the results of a detailed analysis of deaths and birth defects occurring in infants born to mothers living in the area (25 Km radius) of the Pickering nuclear power plant, over an 18-year period. The analysis looked at the frequency of these defects and deaths in comparison to the general rate for Ontario, and also in relation to airborne and waterborne releases of tritium from the power plant. The overall conclusion was that the rates of infant death and birth defects were generally not higher in the study population than in all of Ontario. There was no prevalent relationship between these deaths and defects and tritium releases measured either at the power plant or by ground monitoring stations t some distance from the facility

  6. [Skin defect coverage with micro skin graft].

    Science.gov (United States)

    Gümüş, Nazim; Kaya, Yalçin; Karakaya, Sadik; Camci, Cemalettin

    2002-04-01

    The aim of this study is to coverage of the large skin defect with microskin graft. The wound coverage of the large skin defect may be difficult with auto skin graft. In these patients, split thickness skin graft may be used in a bloc shape or expanded skin graft shape and a stamp skin graft shape or expanded stamp skin graft shape. On the other hand, split thickness skin graft may be used as a micrograft shape after the mincing process, which reduces of the graft size in a few millimeters. In this study, 6 patients with skin defect was admitted in our clinic, and their skin defect was treated with micro skin graft. Expansion ratio was 1:15. Epithelialization on the wound surface was completed in 4 to 6 weeks and cobblestone appearance was observed after the wound coverage. Skin defect coverage with micrograft is an effective technique like the other skin graft coverage methods.

  7. Defect rates in butt welded steel pipes

    International Nuclear Information System (INIS)

    Guille-Stevens, D.; Silcock, P.

    1980-01-01

    As the primary circuit of CANDU reactors consists largely of pipe, the reliability of pipe welds is of interest to reactor designers. A project involving 64 000 manual and semi-automatic pipe welds was inspected to the requirements of ANSI B31.3. Records of 6 000 carbon steel and 1 900 alloy steel butt welds ranging from 50 to 400 mm were inspected by radiography and ultrasonics, and analysed. No correlation between defects and number of weld passes was observed. However, small pipes exhibited a higher defect rate, per weld length and per weld volume, than did large pipes. Porosity was the major cause of defects (60 per cent) followed by root defects (27 per cent); only one crack was recorded. The results show that small (50 mm) pipe welds have the highest defect rate; however, the low overall rate shows that high standards can be maintained over many thousand welds [af

  8. Stafne Bone Defect: Report of Two Cases

    Directory of Open Access Journals (Sweden)

    A. P. Münevveroğlu

    2012-01-01

    Full Text Available Stafne bone defects are asymptomatic lingual bone depressions of the lower jaw. In 1942, Stafne described for the first time 35 asymptomatic, radiolucent cavities, unilaterally located in the posterior region of the mandible, between the mandibular angle and the third molar, below the inferior dental canal and slightly above the basis mandibulae. In this study, the clinical and radiological characteristics of 2 cases of Stafne bone defects were described. Orthopantomograph and CBCT were used for diagnosing the defects. The bone defects of two patients in this study were asymptomatic and any other bone lesions, such as cysts and tumors, were excluded because no signs of inflammatory or tumoral changes were evident Therefore, surgery was not considered and the patients were followed for 1 year. Stafne bone defect was an incidental finding, presenting no evolutionary changes, and as such conservatory therapy based on periodic controls was indicated. Currently, complementary techniques such as CT are sufficient to establish a certain diagnosis.

  9. Topological defect dynamics in operando battery nanoparticles

    Science.gov (United States)

    Ulvestad, Andrew; Meng, Shirley; Shpyrko, Oleg

    2015-03-01

    Topological defects are ubiquitous in physics and manifest themselves as magnetic monopoles in quantum field theories and crystallographic imperfections in condensed matter systems. In the latter, the defect properties determine many of the material's properties and as such represent substantial novel opportunities for design and optimization of desired functionalities through deliberate defect engineering and manipulation. However, this approach of ``defect choreography'' currently suffers from the lack of suitable nanoscale probes to track buried single defects in-situ and in-operando. Here we report 3D imaging of single edge dislocations and their motion in an individual nanoparticle under operando conditions in a Lithium ion battery. We further observe the dislocation act as a nucleation point during the structural phase transformation. We find that the region near the dislocation enters a negative Poisson's ratio, or auxetic, regime at high voltage. Dislocation imaging is thus a powerful nanotechnology and it opens a new, powerful avenue for facilitating improvement of nanostructured devices.

  10. Radioactive preparation of defects in solids

    International Nuclear Information System (INIS)

    Lambe, J.

    1962-01-01

    One of the major areas of interest in solid state physics is the study of defects in nearly perfect crystals. The controlled formation of such defects is thus an important aspect of these studies. Chemical additions and radiation damage are among the techniques which have been widely used to make such defects. In the present work some possibilities have been examined of using radioactive decay to form defects in solids. The technique is simply to make as perfect a material as possible but with some of the host crystal atoms radioactive. When these atoms decay the daughter product essentially forms the defect. As a simple means of testing the feasibility of this technique, it was used to prepare tritium atoms trapped in a crystal of solid molecular tritium. The experiments indicate that the technique is feasible and should have particular application to the preparation of free radicals in organic materials which are fairly resistant to radiation damage. (author) [fr

  11. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...... position was measured on the polymer μ-parts to evaluate filling behavior of the polymer melt flowing through μ-features. Experimental results obtained under different processing conditions were evaluated to correlate the process parameter levels influence on the selected responses. Results showed...... that the injection speed in one of the most influencing process parameters on the μIM process and on the μ-parts filling....

  12. Gap filling strategies for long term energy flux data sets

    DEFF Research Database (Denmark)

    Falge, E.; Baldocchi, D.; Olson, R.

    2001-01-01

    At present a network of over 100 field sites are measuring carbon dioxide, water vapor and sensible heat fluxes between the biosphere and atmosphere, on a nearly continuous basis. Gaps in the long term measurements of evaporation and sensible heat flux must be filled before these data can be used...... for hydrological and meteorological applications. We adapted methods of gap filling for NEE (net ecosystem exchange of carbon) to energy fluxes and applied them to data sets available from the EUROFLUX and AmeriFlux eddy covariance databases. The average data coverage for the sites selected was 69% and 75......% for latent heat (lambdaE) and sensible heat (H). The methods were based on mean diurnal variations (half-hourly binned means of fluxes based on previous and subsequent days, MDV) and look-up tables for fluxes during assorted meteorological conditions (LookUp), and the impact of different gap filling methods...

  13. Radioactive waste slurry dehydrating and drum filling device

    International Nuclear Information System (INIS)

    Ichihashi, Toshio; Abe, Kazuaki; Hasegawa, Akira

    1981-01-01

    Purpose: To obtain a device for simultaneously filling and dehydrating radioactive waste in a waste can without the necessity of a special device for dehydration. Constitution: This device includes a radioactive waste storage tank, a pump for supplying the waste from the tank to a can, a drain tube having a filter at the lower end and installed displaceable in the axial direction of the can, and a drain pump. The slurry stored in the radioactive waste storage tank is supplied by the pump to the can, and the feedwater in the slurry is removed by another pump through a drain pipe having a filter which does not pass solid content from the can. Accordingly, as the slurry is filled in the can, the feedwater contained therein is removed. Consequently, it can simultaneously dehydrate and fill the dehydrated waste in the can. (Yoshihara, H.)

  14. Evolution of Electrically Active Defects in n-GaN During Heat Treatment Typical for Ohmic Contact Formation

    DEFF Research Database (Denmark)

    Boturchuk, Ievgen; Scheffler, Leopold Julian; Larsen, Arne Nylandsted

    2017-01-01

    Ohmic contact formation to n-type GaN often involves high temperature steps, for example sintering at about 800 °C in the case of Ti-based contacts. Such processing steps might cause changes in the distribution, concentration, and properties of the defects. The present work aims at contributing t...... are studied by the means of deep level transient spectroscopy (DLTS). Changes in carrier capture kinetics are monitored with varying filling pulse duration....

  15. Thyroid gland development and defects.

    Science.gov (United States)

    Kratzsch, Juergen; Pulzer, Ferdinand

    2008-02-01

    During the functional ontogenesis of the thyroid gland an increasing number of transcription factors play fundamental roles in thyroid-cell differentiation, maintenance of the differentiated state, and thyroid-cell proliferation. The early growth and development of the fetal thyroid appears to be generally independent of thyroid-stimulating hormone (TSH). TSH and thyroxine (T4) levels increase from the 12th week of gestation until delivery, whereas triiodothyronine (T3) levels remain relatively low. At birth, a cold-stimulated short-lived TSH surge is observed, followed by a TSH decrease until day 3 or 4 of life by T4 feedback inhibition. Disorders of thyroid gland development and/or function are relatively common, affecting approximately one newborn infant in 2000-4000. The most prevalent disease, congenital hypothyroidism, is frequently caused by genetic defects of transcription factors involved in the development of the thyroid or pituitary gland. A major cause of congenital hyperthyroidism is the transplacental passage of stimulating thyrotropin antibodies from the mother to the fetus. Hypothyroxinaemia or hypotriiodthyroninaemia is frequently observed in preterm infants with or without severe non-thyroidal illness. Whereas congenital hypo- and hyperthyroidism may be treated successfully with T4 or thyrostatic drugs, there is still insufficient evidence on whether the use of T4 for treatment of the latter condition results in changes in neonatal morbidity or reductions in neurodevelopmental impairment.

  16. Characterization of the structure and chemistry of defects in materials

    International Nuclear Information System (INIS)

    Larson, B.C.; Ruehle, M.; Seidman, D.N.

    1988-01-01

    Research programs, presented at the materials research symposium, on defects in materials are presented. Major areas include: point defects, defect aggregates, and ordering; defects in non-metals and semiconductors; atomic resolution imaging of defects; and gain boundaries, interfaces, and layered materials. Individual projects are processed separately for the data bases

  17. Distribution of defects in wind turbine blades and reliability assessment of blades containing defects

    DEFF Research Database (Denmark)

    Stensgaard Toft, Henrik; Branner, Kim; Berring, Peter

    2009-01-01

    on the assumption that one error in the production process tends to trigger several defects. For both models additional information about number, type and size of the defects is included as stochastic variables. The probability of failure for a wind turbine blade will not only depend on variations in the material......In the present paper two stochastic models for the distribution of defects in wind turbine blades are proposed. The first model assumes that the individual defects are completely randomly distributed in the blade. The second model assumes that the defects occur in clusters of different size based...... properties and the load but also on potential defects in the blades. As a numerical example the probability of failure is calculated for the main spar both with and without defects in terms of delaminations. The delaminations increase the probability of failure compared to a perfect blade, but by applying...

  18. Reliability and Validity of "Invisible-Gap Filling" Items

    OpenAIRE

    靜, 哲人

    2004-01-01

    The purpose of this study was to explore the potential of "invisible-gap filling" items primarily as an in-house achievement measure of reading-oriented courses and secondarily as a more general overall-ability measure. More specifically, it compared multiple-matching "invisible-gap filling" items and their "visible" counterparts in terms of item facility, item discrimination, test reliability, and test validity.Eighty-eight Japanese university 1st year students took a 25-item invisible-gap f...

  19. Aggravated neuromuscular symptoms of mercury exposure from dental amalgam fillings.

    Science.gov (United States)

    Akbal, Ayla; Yılmaz, Hınç; Tutkun, Engin; Köş, Durdu Mehmet

    2014-01-01

    Dental amalgam fillings are widely used all over the world. However, their mercury content can lead to various side effects and clinical problems. Acute or chronic mercury exposure can cause several side effects on the central nerve system, renal and hepatic functions, immune system, fetal development and it can play a role on exacerbation of neuromuscular diseases. In this case, we will present a patient with vacuolar myopathy whose symptoms were started and aggravated with her dental amalgam fillings. Copyright © 2013 Elsevier GmbH. All rights reserved.

  20. Modelling of the filling up of a porous plate

    International Nuclear Information System (INIS)

    Sampaio, R.; Gama, R.M.S. da.

    1985-01-01

    A generalization of Darcy's law is constructed using Mixture Theory to describe the transient flow of an incompressible fluid through a rigid solid porous matrix. The model is used to study the process of filling-up of an one dimensional unsaturated porous medium that is mathematically described by a system of nonlinear hyperbolic equations that is non-homogeneous due to the drag force between the fluid and the solid matrix. The system is analysed throughly and solved numerically using the Glimm-Chorin method with a splitting to treat the non-homogeneous term. The results are discussed and shown to describe well the filling-up process. (Author) [pt