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Sample records for 1-wall intrabony defects

  1. The effects of hydroxyapatite/calcium phosphate glass scaffold and its surface modification with bovine serum albumin on 1-wall intrabony defects of beagle dogs: a preliminary study.

    PubMed

    Um, Yoo-Jung; Jung, Ui-Won; Chae, Gyung-Joon; Kim, Chang-Sung; Lee, Yong-Keun; Cho, Kyoo-Sung; Kim, Chong-Kwan; Choi, Seong-Ho

    2008-12-01

    The purpose of this study was to evaluate the effects of biphasic hydroxyapatite/calcium phosphate glass (HA/CPG) scaffold and its surface modification with bovine serum albumin (BSA) on periodontal regeneration. 1-wall intrabony defects were surgically created on five beagle dogs. HA/CPG scaffolds, with a hydroxyapatite (HA)/calcium phosphate glass (CPG) ratio of 95:5 by weight (%) and surface modification done by 2% bovine serum albumin, were used. The control group received surgical flap operation, and the experimental groups were filled with HA/CPG scaffolds and HA/CPG(BSA) scaffolds. The animals were sacrificed eight weeks after surgery. Histological findings revealed better space maintenance in the experimental groups than the control group, and showed new bone formation intermittently in between the residual material particles. The newly formed bone was mostly woven bone and the residual particles were undergoing resorption. Cementum regeneration was observed with limited root resorption in all the groups. Histometric analysis also revealed greater mean values in new bone formation, cementum regeneration and bone area than the control group in both experimental groups. However, similar findings were presented between HA/CPG and HA/CPG(BSA). The result of the present study revealed the newly fabricated HA/CPG scaffold to have a potential use as a bone substitute material.

  2. Oral telangiectatic granuloma with an intrabony defect

    PubMed Central

    Rathore, Akanksha; Jadhav, Tanya; Kulloli, Anita; Singh, Archana

    2015-01-01

    Oral telangiectatic granuloma is a benign hyperplastic lesion occurring in response to trauma or chronic irritation in the oral cavity. The characteristic histological appearance comprises of typical granulation tissue with a proliferation of small thin-walled blood vessels in the loose connective tissue. We describe a case of a 36-year-old female who had a swelling in the left maxillary region which was associated with the intrabony defect. An internal bevel gingivectomy was performed, and the histopathological report was suggestive of telangiectatic granuloma. The intrabony defect was managed with the placement of platelet rich fibrin plug in the defect. A follow-up at 6 months showed no recurrence and no loss in the width of keratinized tissue. The aim of this case is to highlight the rare association of intrabony defect with telangiectatic granuloma and the need for histopathological diagnosis in such lesions. PMID:26941527

  3. Comparison of Different Periodontal Healing of Critical Size Noncontained and Contained Intrabony Defects in Beagles

    PubMed Central

    Zang, Sheng-Qi; Kang, Shuai; Hu, Xin; Wang, Meng; Wang, Xin-Wen; Zhou, Tao; Wang, Qin-Tao

    2017-01-01

    Background: Regenerative techniques help promote the formation of new attachment and bone filling in periodontal defects. However, the dimensions of intraosseous defects are a key determinant of periodontal regeneration outcomes. In this study, we evaluated the efficacy of use of anorganic bovine bone (ABB) graft in combination with collagen membrane (CM), to facilitate healing of noncontained (1-wall) and contained (3-wall) critical size periodontal defects. Methods: The study began on March 2013, and was completed on May 2014. One-wall (7 mm × 4 mm) and 3-wall (5 mm × 4 mm) intrabony periodontal defects were surgically created bilaterally in the mandibular third premolars and first molars in eight beagles. The defects were treated with ABB in combination with CM (ABB + CM group) or open flap debridement (OFD group). The animals were euthanized at 8-week postsurgery for histological analysis. Two independent Student's t-tests (1-wall [ABB + CM] vs. 1-wall [OFD] and 3-wall [ABB + CM] vs. 3-wall [OFD]) were used to assess between-group differences. Results: The mean new bone height in both 1- and 3-wall intrabony defects in the ABB + CM group was significantly greater than that in the OFD group (1-wall: 4.99 ± 0.70 mm vs. 3.01 ± 0.37 mm, P < 0.05; 3-wall: 3.11 ± 0.59 mm vs. 2.08 ± 0.24 mm, P < 0.05). The mean new cementum in 1-wall intrabony defects in the ABB + CM group was significantly greater than that in their counterparts in the OFD group (5.08 ± 0.68 mm vs. 1.16 ± 0.38 mm; P < 0.05). Likewise, only the 1-wall intrabony defect model showed a significant difference with respect to junctional epithelium between ABB + CM and OFD groups (0.67 ± 0.23 mm vs. 1.12 ± 0.28 mm, P < 0.05). Conclusions: One-wall intrabony defects treated with ABB and CM did not show less periodontal regeneration than that in 3-wall intrabony defect. The noncontained 1-wall intrabony defect might be a more discriminative defect model for further research into periodontal

  4. Periodontal response after tooth movement into intrabony defects.

    PubMed

    Polson, A; Caton, J; Polson, A P; Nyman, S; Novak, J; Reed, B

    1984-04-01

    The present study was undertaken since conflicting evidence exists regarding the effect of such tooth movement on levels of connective tissue attachment. Localized intrabony pockets were produced around isolated incisors in four rhesus monkeys. The root surfaces were planned to the level of the bone at the base of the angular bony defects. An oral hygiene regime was begun and continued for the remainder of the study. The experimental teeth were moved orthodontically into, and through, the original area of the intrabony defect. Two months after cessation of active tooth movement, block specimens were removed for histologic analysis. Control specimens comprised those teeth with induced periodontal defects, but without tooth movement. In specimens not subjected to tooth movement, angular bony defects were present and epithelium lined the root surface to the apical extent of instrumentation. The alveolar bone adjacent to the orthodontically moved teeth no longer had angular defect morphology. On the pressure side, epithelium lined the root surface, was interposed between root surface and bone and terminated at the apical limit of root instrumentation. On the tension side, the crest of the bone was located apical to the level of root planing, and epithelium lined the instrumented portion of the root surface. It was concluded that orthodontic tooth movement into intrabony periodontal defects was without effect upon the levels of connective tissue attachment.

  5. Bioactive glass and connective tissue graft used to treat intrabony periodontal defects.

    PubMed

    Deliberador, Tatiana Miranda; Trotta, Daniel Rizzo; Klug, Luis Gustavo; Zielak, Joao Cesar; Giovanini, Allan Fernando

    2013-07-01

    Different techniques and materials can be used to treat intrabony periodontal defects caused by periodontal diseases. This case report presents an intrabony periodontal defect with bioactive glass and connective tissue graft used as a barrier. Probing depth and clinical attachment gain were reduced at 6 and 12 months post-treatment.

  6. Clinical concepts for regenerative therapy in intrabony defects.

    PubMed

    Cortellini, Pierpaolo; Tonetti, Maurizio S

    2015-06-01

    Evidence indicates that periodontal regeneration is an efficacious and predictable procedure for the treatment of isolated and multiple intrabony defects. Meta-analyses from systematic reviews indicate an added benefit, in terms of clinical attachment level gain, when demineralized freeze-dried bone allograft, barrier membranes and active biologic products/compounds are applied in addition to open flap debridement. On the other hand, a consistent amount of variability of the outcomes is evident among different studies and within the experimental population of each study. This variability is explained, at least in part, by different patient and defect characteristics. Patient-related factors include smoking habit, compliance with home oral hygiene and residual inflammation after cause-related therapy. Defect-associated factors include defect depth and radiographic angle, the number of residual bony walls, pocket depth and the degree of hypermobility. In addition, surgical-related variables, such as surgical skill, clinical experience and knowledge, and application of the different regenerative materials, have a significant impact on clinical outcomes. This paper presents a strategy to optimize the clinical outcomes of periodontal regeneration. The surgical design of the flap, the use of different regenerative materials and the application of appropriate passive sutures are discussed in this review along with the scientific foundations.

  7. Periosteum as a barrier membrane in the treatment of intrabony defect: A new technique

    PubMed Central

    Saimbi, Charanjeet Singh; Gautam, Anju; Khan, Mohd. Akhlak; Nandlal

    2014-01-01

    Objective: The purpose of the study was to evaluate the clinical effectiveness of periosteum as a barrier membrane for the treatment of intrabony defects. Materials and Methods: The study was conducted in patients having bilateral intrabony defects. A total of 20 intrabony defects in 10 patients were treated, out of which 10 defects received periosteal barrier and the other 10 defects received conventional open flap debridement procedure. The efficacy of the treatment was assessed using clinical parameters and dentascan. Results: Statistically significant gain in clinical attachment level (CAL) was found in the test group (2.00 ± 0.26 mm) as compared to the control group (0.60 ± 0.22 mm). In both the treatment modalities (test and control groups), a significant decrease in probing pocket depth of 3.90 ± 0.35 mm and 2.90 ± 0.31 mm was observed, respectively. The difference between the two groups was not statistically significant. Bone defect fill was 1.40 ± 0.16 mm for the test group and 0.90 ± 0.18 mm for the control group, but the difference observed was not statistically significant. Conclusion: The results of this study show that periosteal barrier membrane can be a better alternative of barrier membranes for the treatment of intrabony defects. PMID:25024547

  8. Entire papilla preservation technique in the regenerative treatment of deep intrabony defects: 1-Year results.

    PubMed

    Aslan, Serhat; Buduneli, Nurcan; Cortellini, Pierpaolo

    2017-09-01

    This study evaluates the clinical outcomes of a novel tunnel-like surgical technique in the treatment of isolated deep intrabony defects. Twelve patients presenting with at least one isolated deep intrabony defect received regenerative periodontal treatment with "entire papilla preservation (EPP)" technique. Access to the intrabony defect for debridement was provided by a bevelled vertical releasing incision positioned in the buccal gingiva of the neighbouring inter-dental space. Following the elevation of a buccal flap, an inter-dental tunnel was prepared undermining the defect-associated papilla. Granulation tissue was removed, root surfaces were carefully debrided and bone substitutes and enamel matrix derivative were applied. Microsurgical suturing technique was used for optimal wound closure. Early healing was uneventful in all cases, and 100% wound closure was maintained during the entire healing period. At 1-year, there was significant attachment gain of 6.83±2.51 mm (p<0.001). The 7±2.8 mm reduction in probing depth was also significant (p<0.001), which was associated with minimal increase in gingival recession (0.16±0.38 mm, p=0.166). Tunnel-like "EPP" technique may limit the risk of wound failure particularly in the early healing phase, thereby preventing exposure of regenerative biomaterials, possibly enhancing stabilization of blood clot in deep intrabony defects and leading to optimal clinical outcomes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Combined Regenerative and Mucogingival Treatment of Deep Intrabony Defects Associated with Buccal Gingival Recession: Two Case Reports.

    PubMed

    Santoro, Giacomo; Zucchelli, Giovanni; Gherlone, Enrico

    The case reports presented in this article describe a surgical approach for improving root coverage and regenerative parameters in deep intrabony defects associated with buccal gingival recession. A mandibular canine and a maxillary premolar were treated. The surgical technique consisted of a connective tissue graft (CTG) that was placed and sutured at the inner surface of a coronally advanced envelope flap (CAF), thickening the buccal soft tissue wall of the most coronal extension of the intrabony defect and treated with biomaterials as scaffold. No palatal/lingual flap was elevated. Two years after the surgery, clinically significant root coverage, increased buccal keratinized tissue height and thickness, some minor improvement in the position of the interdental papilla, and clinical attachment level gain were achieved. The radiographs showed bone fill of the intrabony components of the defects. This report encourages a novel application of CAF + CTG + biomaterials to improve both esthetic and regenerative parameters in deep intrabony defects associated with gingival recessions.

  10. Efficacy of Connective Tissue with and without Periosteum in Regeneration of Intrabony Defects

    PubMed Central

    Esfahanian, Vahid; Golestaneh, Hedayatollah; Moghaddas, Omid; Ghafari, Mohammad Reza

    2014-01-01

    Background and aims. Connective tissue grafts with and without periosteum is used in regenerative treatments of bone and has demonstrated successful outcomes in previous investigations. The aim of present study was to evaluate the effectiveness of connective tissue graft with and without periosteum in regeneration of intrabony defects. Materials and methods. In this single-blind randomized split-mouth clinical trial, 15 pairs of intrabony defects in 15 patients with moderate to advanced periodontitis were treated by periosteal connective tissue graft + ABBM (test group) or non-periosteal connective tissue graft + ABBM (control group). Probing pocket depth, clinical attachment level, free gingival margin position, bone crestal position, crest defect depth and defect depth to stent were measured at baseline and after six months by surgical re-entry. Data was analyzed by Student’s t-test and paired t-tests (α=0.05). Results. Changes in clinical parameters after 6 months in the test and control groups were as follows: mean of PPD reduction: 3.1±0.6 (P<0.0001); 2.5±1.0 mm (P<0.0001), CAL gain: 2.3±0.9 (P<0.0001); 2.2±1.0 mm (P<0.0001), bone fill: 2.2±0.7 mm (P<0.0001); 2.2±0.7 mm (P<0.0001), respectively. No significant differences in the position of free gingival margin were observed during 6 months compared to baseline in both groups. Conclusion. Combinations of periosteal connective tissue graft + ABBM and non-periosteal connective tissue graft + ABBM were similarly effective in treating intrabony defects without any favor for any group. Connective tissue and perio-steum can be equally effective in regeneration of intrabony defects. PMID:25587379

  11. Efficacy of Connective Tissue with and without Periosteum in Regeneration of Intrabony Defects.

    PubMed

    Esfahanian, Vahid; Golestaneh, Hedayatollah; Moghaddas, Omid; Ghafari, Mohammad Reza

    2014-01-01

    Background and aims. Connective tissue grafts with and without periosteum is used in regenerative treatments of bone and has demonstrated successful outcomes in previous investigations. The aim of present study was to evaluate the effectiveness of connective tissue graft with and without periosteum in regeneration of intrabony defects. Materials and methods. In this single-blind randomized split-mouth clinical trial, 15 pairs of intrabony defects in 15 patients with moderate to advanced periodontitis were treated by periosteal connective tissue graft + ABBM (test group) or non-periosteal connective tissue graft + ABBM (control group). Probing pocket depth, clinical attachment level, free gingival margin position, bone crestal position, crest defect depth and defect depth to stent were measured at baseline and after six months by surgical re-entry. Data was analyzed by Student's t-test and paired t-tests (α=0.05). Results. Changes in clinical parameters after 6 months in the test and control groups were as follows: mean of PPD reduction: 3.1±0.6 (P<0.0001); 2.5±1.0 mm (P<0.0001), CAL gain: 2.3±0.9 (P<0.0001); 2.2±1.0 mm (P<0.0001), bone fill: 2.2±0.7 mm (P<0.0001); 2.2±0.7 mm (P<0.0001), respectively. No significant differences in the position of free gingival margin were observed during 6 months compared to baseline in both groups. Conclusion. Combinations of periosteal connective tissue graft + ABBM and non-periosteal connective tissue graft + ABBM were similarly effective in treating intrabony defects without any favor for any group. Connective tissue and perio-steum can be equally effective in regeneration of intrabony defects.

  12. Biomaterials for promoting periodontal regeneration in human intrabony defects: a systematic review.

    PubMed

    Sculean, Anton; Nikolidakis, Dimitris; Nikou, George; Ivanovic, Aleksandar; Chapple, Iain L C; Stavropoulos, Andreas

    2015-06-01

    Intrabony periodontal defects are a frequent complication of periodontitis and, if left untreated, may negatively affect long-term tooth prognosis. The optimal outcome of treatment in intrabony defects is considered to be the absence of bleeding on probing, the presence of shallow pockets associated with periodontal regeneration (i.e. formation of new root cementum with functionally orientated inserting periodontal ligament fibers connected to new alveolar bone) and no soft-tissue recession. A plethora of different surgical techniques, often including implantation of various types of bone graft and/or bone substitutes, root surface demineralization, guided tissue regeneration, growth and differentiation factors, enamel matrix proteins or various combinations thereof, have been employed to achieve periodontal regeneration. Despite positive observations in animal models and successful outcomes reported for many of the available regenerative techniques and materials in patients, including histologic reports, robust information on the degree to which reported clinical improvements reflect true periodontal regeneration does not exist. Thus, the aim of this review was to summarize, in a systematic manner, the available histologic evidence on the effect of reconstructive periodontal surgery using various types of biomaterials to enhance periodontal wound healing/regeneration in human intrabony defects. In addition, the inherent problems associated with performing human histologic studies and in interpreting the results, as well as certain ethical considerations, are discussed. The results of the present systematic review indicate that periodontal regeneration in human intrabony defects can be achieved to a variable extent using a range of methods and materials. Periodontal regeneration has been observed following the use of a variety of bone grafts and substitutes, guided tissue regeneration, biological factors and combinations thereof. Combination approaches appear to

  13. Autologous Platelet Rich Fibrin in the Treatment of 3-Wall Intrabony Defects in Aggressive Periodontitis - A Randomized Controlled Clinical Trial.

    PubMed

    Bajaj, Pavan; Agarwal, Esha; Rao, Nishanth S; Naik, Savitha B; Pradeep, A R; Kalra, Nitish; Priyanka, N; Kumari, Minal

    2017-08-18

    Platelet rich fibrin (PRF), has recently found its application in osseous regeneration. The aim of present study is to explore the efficacy of PRF in treatment of intrabony defects in aggressive periodontitis. 54 intrabony defects in 17 patients were treated either with autologous PRF with open flap debridement (OFD) or OFD alone. Clinical and radiological parameters such as probing depth (PD), clinical attachment level (CAL), intrabony defect depth and % defect change were recorded at baseline and 9 months postoperatively. Mean PD reduction and mean CAL gain was significantly greater in PRF as compared to control group. Furthermore, significantly greater percentage of mean bone defect change was found in the PRF group. Within the limit of the present study, there was greater greater bone fill at sites treated with PRF with conventional OFD than conventional OFD alone.

  14. Bioactive glass efficacy in the periodontal healing of intrabony defects in monkeys.

    PubMed

    Villaça, José Henrique; Novaes, Arthur B; Souza, Sérgio Luís Scombatti de; Taba, Mario; Molina, Gustavo Otoboni; Carvalho, Teresa Lúcia Lamano

    2005-01-01

    The purpose of this study was the histomorphologic analysis of the efficacy of bioactive glass particles with a narrow size range (Biogran) in the periodontal healing of 2-wall intrabony defects in monkeys. The 2-wall defects were made in the mesial area of the left and right second premolars of four monkeys, filled with gutta-percha and, after 15 days, they were debrided and either naturally filled with coagulum (control) or implanted with bioactive glass (test). In the control sites, the junctional epithelium migrated up to the base of the defect. The presence of newly formed cementum was more significant in the test defects. Both control and test sites showed newly formed bone at the base of the defect. The test defects presented foci of newly formed bone around and within the glass particles localized in the middle third, distant from the defect walls. Histologic analysis showed that the 300- to 355-microm bioactive glass particles aided new periodontal insertion. In conclusion, the tested bioactive glass had better healing potential than debridement only. The graft material showed a promising inhibition of apical migration of the junctional epithelium and greater cementum deposition on the radicular surface of the intrabony defects. The replacement of bioactive glass particles by new bone occurred due not only to an osteoconductive property, but also to an osteostimulatory capacity. Future investigations should evaluate this potential comparatively or together with other grafting materials, regenerative techniques and biological modifiers, as well as assess the longitudinal stability of the new attachment.

  15. Periodontal healing after impacted lower third molar surgery. Precision and accuracy of radiographic assessment of intrabony defects.

    PubMed

    Kugelberg, C F; Ahlström, U; Ericson, S; Hugoson, A

    1986-12-01

    The effect of periodontal tissues of impacted lower 3rd molar surgery has been investigated in a retrospective study comprising 215 cases, 2 years postoperatively. In order to evaluate the precision and accuracy of the radiographic assessment of intrabony defects on the distal surface of the lower 2nd molar using conventional free hand technique, a methodological study was performed on 25 patients. The error variance due to variability in the radiographic reproduction and examiner inconsistency was between 3 and 4% of the total variance. In order to evaluate the radiographic assessment of intrabony defects, intraoral radiographs were taken in the deepest part of the intrabony defect with and without a probe as an indicator. Comparing the 2 sets of radiographs, the deviation was 1 mm or less in 87.9% of the cases. The radiopaque marker enhanced the accuracy of assessment of intrabony defects to 96.7%. The study shows the intraoral freehand technique to be sufficiently reliable as regards radiographic reproduction of the mandibular molar area. It also demonstrates that the radiographic method describes the depth of postoperative intrabony defects on the distal surface of the lower 2nd molar more accurately than probing depth measurements alone.

  16. Intrabony defects, open-flap debridement, and decortication: a randomized clinical trial.

    PubMed

    Crea, Alessandro; Deli, Giorgio; Littarru, Cristiano; Lajolo, Carlo; Orgeas, Gianluca Vittorini; Tatakis, Dimitris N

    2014-01-01

    Intramarrow penetration (IMP) is often incorporated in regenerative periodontal surgical procedures. However, the actual benefits of adding IMP to such a procedure remain undocumented. The purpose of this randomized controlled trial was to investigate the contribution of IMP to the outcomes of open-flap debridement (OFD) treatment of intrabony defects. Forty-two chronic periodontitis patients, each contributing a 2-wall, 3-wall, or combined 2- to 3-wall intrabony defect, were treated. Sites were randomly assigned into one of two groups: control (OFD alone) or test (OFD + IMP). Papilla preservation flaps were raised, and defects were thoroughly debrided. In the control group, complete primary closure of flaps was ensured after debridement. In the test group, IMP was performed before flap closure, using a round bur to penetrate the cortical defect wall. Clinical and radiographic parameters were assessed at baseline and 12 months after treatment. At baseline, there were no statistically significant differences between groups. At 12 months, both groups experienced significant improvements, in terms of probing depth reduction, clinical attachment level (CAL) gain, and bone level (clinical and radiographic). The test group experienced significantly greater clinical bone gain (3.07 ± 1.74 mm) and prevalence of CAL gain ≥2 mm (93% of sites) compared with the control group (1.76 ± 2.71 mm, P <0.03; 62%, P = 0.024). The test treatment benefits were particularly evident in mandibular sites, in which OFD + IMP doubled the radiographic bone gain obtained by OFD alone. Addition of IMP to an OFD procedure used to treat intrabony defects results in statistically and clinically significant enhancement of both clinical and radiographic outcomes.

  17. Platelet Rich Fibrin (PRF) in Regeneration of Intrabony Defects- A Randomized Controlled Trial.

    PubMed

    Kumar Patel, Gauresh; Kumar Gujjari, Sheela; Kumar S C, Veerendra

    2017-08-18

    Platelet-rich fibrin (PRF) is a autologous non transfusional hemo-component with a high concentration of platelets. It incorporates leukocytes, platelets and growth factors within the dense fibrin matrix and can be used as healing biomaterial. This study assessed the adjunctive use of PRF in regenerative management of intrabony defects in comparison with open flap debridement. 26 bilateral defects (13 per group) in 13 patients were randomized as either PRF (Test group) or Open flap debridement alone (control group) sites. Probing depth (PD), clinical attachment level (CAL) and bone probing depth were recorded. Reduction in defect depth and percentage of bone fill was assessed radiographically. Primary outcomes assessed were the changes in pocket depth, attachment level and percentage of bone fill assessed at 6months, 9 months and 12 months. Secondary outcome was assessment of wound healing using a wound healing index. The PRF group showed significant improvement in clinical parameters over control group at 6, 9, and 12 months. PRF group showed a bone fill of 45.18±7.57 percent which was statistically significant compared to 21.6±9.3 percent seen in control group at end of study period. Wound healing index (WHI) also showed significant advantages for the PRF group. PRF also showed significant soft tissue healing and reduction in probing depth. The adjunctive use of PRF to conventional open flap debridement may be potentially used in the treatment of intrabony defects.

  18. Management of a One-wall Intrabony Osseous Defect with Combination of Platelet Rich Plasma and Demineralized Bone Matrix- a Two-year Follow up Case Report

    PubMed Central

    Thakkalapati, Parthasaradhi; R Chandran, Chitraa; Ranganathan, Aravindhan Thiruputkuzhi; Jain, Ashish Ratahanchand; Prabhakar, Priya; Padmanaban, Suganya

    2015-01-01

    Periodontal regeneration in a one-wall intrabony defect is a challenging and complex phenomenon. The combination therapy of commercially available bone grafts with the innovative tissue engineering strategy, the platelet rich plasma, has emerged as a promising grafting modality for two and three walled intrabony osseous defects. The application of this combination approach was attempted in a most challenging one-wall intrabony defect. Open flap debridement and placement of combination of autologous platelet rich plasma(PRP) and demineralized bone matrix was done in one-wall intrabony defect in relation to tooth #21 in a 30 year old female patient. The 6-month follow- up results showed significant improvement in clinical parameters. Radiographic evidence of bone formation was observed as early as 3 months with almost complete fill by 6 months post-operatively. The results were maintained over a period of 2 years. PMID:26331153

  19. Treatment of intrabony defects with anorganic bone matrix/p-15 or guided tissue regeneration in patients with aggressive periodontitis.

    PubMed

    Queiroz, Adriana C; Nóbrega, Priscila Brasil da; Oliveira, Fabíola S; Novaes, Arthur B; Taba, Mário; Palioto, Daniela B; Grisi, Márcio F M; Souza, Sergio L S

    2013-01-01

    Intrabony periodontal defects present a particular treatment problem, especially in patients with generalized aggressive periodontitis (G-AgP). Regenerative procedures have been indicated for this clinical situation. The aim of this study was to compare treatment outcomes of intrabony periodontal defects with either anorganic bone matrix/cell binding peptide (ABM/P-15) or guided tissue regeneration (GTR) in patients with G-AgP. Fifteen patients, with two intrabony defects ≥3 mm deep, were selected. Patients were randomly allocated to be treated with ABM/P-15 or GTR. At baseline and at 3 and 6 months after surgery, clinical and radiographic parameters and IL-1β and IL-6 gingival fluid concentrations were recorded. There was a significant probing pocket depth reduction (p<0.001) for both groups (2.27 ± 0.96 mm for ABM/P-15 group and 2.57 ± 1.06 mm for GTR group). Clinical attachment level gain (1.87 ± 0.94 mm for ABM/P-15 group and 2.09 ± 0.88 mm for GTR group) was also observed. There were no statistically significant differences in clinical parameters between the groups. The radiographic bone fill was more expressive in ABM/P-15 group (2.49 mm) than in GTR group (0.73 mm). In subtraction radiographs, the areas representing gain in density were 93.16% of the baseline defect for ABM/P-15 group versus 62.03% in GRT group. There were no statistically significant differences in inter-group and intra-group comparisons with regards to IL-1β and IL-6 quantification. Treatment of intrabony periodontal defects in patients with G-AgP with ABM/P-15 and GTR improved significantly the clinical outcomes. The use of ABM/P-15 promoted a better radiographic bone fill.

  20. Evaluation of the efficacy of a bioactive synthetic graft material in the treatment of intrabony periodontal defects.

    PubMed

    Grover, Vishakha; Kapoor, Anoop; Malhotra, Ranjan; Uppal, Ranjit Singh

    2013-01-01

    Bioactive ceramic fillers are synthetic materials which have shown the potential to enhance bone formation. The purpose of this study was to evaluate the efficacy of a bioactive synthetic graft material in the treatment of intrabony periodontal defects. Fourteen intrabony defects in twelve systemically healthy subjects having moderate to severe chronic periodontitis were evaluated after bone grafting with bioactive ceramic filler for a period of 6 months. Clinical and radiographic evaluations were made at baseline, at 3 and 6 months following surgery. Mean radiographic defect fill of 64.76% (2.49±0.5 mm) was observed in 6 months, which was statistically significant. A statistically significant relative attachment level gain of 2.71±1.13 mm and probing pocket depth reduction of 4.21±1.18 mm was recorded at the end of the study. A significant decrease in mobility and gingival index was observed. Bioactive glass is an efficacious treatment option for the reconstruction of intrabony periodontal defects as it led to statistically significant improvements in the clinical and radiographic parameters.

  1. Evaluation of the efficacy of a bioactive synthetic graft material in the treatment of intrabony periodontal defects

    PubMed Central

    Grover, Vishakha; Kapoor, Anoop; Malhotra, Ranjan; Uppal, Ranjit Singh

    2013-01-01

    Background: Bioactive ceramic fillers are synthetic materials which have shown the potential to enhance bone formation. The purpose of this study was to evaluate the efficacy of a bioactive synthetic graft material in the treatment of intrabony periodontal defects. Materials and Methods: Fourteen intrabony defects in twelve systemically healthy subjects having moderate to severe chronic periodontitis were evaluated after bone grafting with bioactive ceramic filler for a period of 6 months. Clinical and radiographic evaluations were made at baseline, at 3 and 6 months following surgery. Results: Mean radiographic defect fill of 64.76% (2.49±0.5 mm) was observed in 6 months, which was statistically significant. A statistically significant relative attachment level gain of 2.71±1.13 mm and probing pocket depth reduction of 4.21±1.18 mm was recorded at the end of the study. A significant decrease in mobility and gingival index was observed. Conclusions: Bioactive glass is an efficacious treatment option for the reconstruction of intrabony periodontal defects as it led to statistically significant improvements in the clinical and radiographic parameters. PMID:23633783

  2. Clinical and radiographic evaluation of periodontal intrabony defects by open flap surgery alone or in combination with Biocollagen® membrane: A randomized clinical trial

    PubMed Central

    Elkhatat, Essam I.; Elkhatat, Amr E.; Azzeghaiby, Saleh N.; Tarakji, Bassel; Beshr, Khaled; Mossa, Hossam

    2015-01-01

    Background: Guided tissue regeneration (GTR) is often incorporated in regenerative periodontal surgical procedures. However, the actual benefits of adding GTR to such a procedure remain undocumented. The purpose of this randomized controlled trial was to investigate the contribution of GTR to the outcomes of open flap debridement (OFD) in the treatment of intrabony defects. Materials and Methods: A total of 16 patients of both sexes satisfying the criteria of chronic periodontitis and each of whom displayed one intrabony defect were randomly assigned to two groups, i.e. either treated with open flap surgery and GTR (group 1) or with open flap surgery alone (group 2), in this parallel-arm study. The soft tissue and hard tissue measurements, including probing pocket depth (PD), clinical attachment level (CAL), and bone mineral density were recorded at baseline and 3,6 and 12 months after surgery. The differences with a P < 0.05 were considered significant. Results: Results showed that the membrane group showed significant difference when compared with open flap surgery alone, in relation to the degree of periodontal pocket, clinical attachment loss, and bone density. Conclusion: The findings of this study suggest that biocollagen membrane could be considered as an option in the treatment of intrabony defects. Biocollagen membrane alone gives favorable clinical results in the treatment of intrabony defects. Open flap debridement resulted in acceptable clinical results in the treatment of intrabony defects. PMID:26236678

  3. Evaluation of a bioresorbable collagen membrane of fish origin in the treatment of periodontal intrabony defects: A prospective clinical study

    PubMed Central

    Santosh Kumar, B.B.; Aruna, D.R.; Gowda, S. Vinayak; Galagali, R. Sushama

    2013-01-01

    Background: Recently, there has been interest in non-mammalian collagen sources such as fish collagen in the development of biomatrices and scaffolds for periodontal regeneration. In the present study, a novel collagen barrier membrane of fish origin was assessed in the treatment of periodontal intra-bony defects. Materials and Methods: Ten systemically healthy chronic periodontitis patients having an osseous defect in the mandibular posterior teeth were selected and following the open flap debridement, a collagen membrane was placed over the defect and the flap was sutured with interrupted sutures. Clinical parameters such as Plaque Index, Gingival Bleeding Index, probing pocket depth (PPD), relative attachment level (RAL), and recession (R) were recorded at baseline, 6 and 9 months, whereas radiographic evaluation was done to assess alveolar crestal bone level and defect depth fill at 6 and 9 months using Auto-computer aided design (ACAD) 2007 software. Statistical significance was set at 5% level of significance. Results: There was statistical significant differences with respect to periodontal clinical parameters such as Plaque Index, Gingival Bleeding Index, PPD, RAL, and gingival recession assessed at baseline, at 6 and 9 months respectively (P < 0.05), and radiographic evaluation showed a defect fill of 58.62 median % at 9 months. Conclusion: This preliminary study has shown predictable results in using fish collagen membrane, for treating periodontal intra-bony defects. Further, long-term clinical trials are needed to validate the effectiveness of this membrane. PMID:23946741

  4. Platelet-rich plasma plus bioactive glass in the treatment of intra-bony defects: a study in dogs

    PubMed Central

    CARVALHO, Marcelo Diniz; SUAID, Fabrícia Ferreira; SANTAMARIA, Mauro Pedrine; CASATI, Marcio Zaffalon; NOCITI Jr., Francisco Humberto; SALLUM, Antonio Wilson; SALLUM, Enilson Antônio

    2011-01-01

    Objective This study was designed to evaluate, histomorphometrically, the association of platelet-rich plasma (PRP) and bioactive glass (BG) in the treatment of periodontal intrabony defects. Material and Methods Nine mongrel dogs were included in the study. Three-wall intrabony defects were surgically created at the mesial and distal aspect of first mandibular molar and exposed to plaque accumulation for 1 month. The defects were randomly assigned to the groups: control, BG, PRP, PRP+BG. Dogs were sacrificed 90 days after the surgeries. The histometric parameters evaluated were: length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone, defect extension and area of new bone filling the defect. Results A superior area of new bone was observed in PRP+BG and BG (13.80±2.32 mm2 and 15.63±2.64 mm2, respectively) when compared to the other groups (8.19±1.46 mm2 and 8.81±1.47 mm2 for control and PRP, respectively). No statistically significant differences were observed in the remaining parameters. Conclusion Within the limits of this study, it may be concluded that PRP failed to provide statistically significant improvements in the histometric parameters. PMID:21437475

  5. Long-term outcome following regenerative periodontal treatment of intrabony defects.

    PubMed

    Rattanasuwan, Kanyawat; Lertsukprasert, Krittawat; Rassameemasmaung, Supanee; Komoltri, Chulaluk

    2016-05-19

    This study aimed to evaluate the long-term outcome of the regenerative periodontal therapy of an intrabony defect in terms of tooth survival and clinical attachment level (CAL) stability. The association between failure and patient as well as tooth variables was assessed. Treatment records of the patients who received regenerative surgery and re-evaluation at 1-year post-surgery were screened. Patient and tooth variables, defect characteristics, and types of treatments were collected. Periodontal parameters were retrieved before regenerative surgery (baseline), 1-year post-surgery, and every visits of supportive periodontal treatment (SPT) until failure, including tooth loss or CAL loss ≥2 mm was found. In this study, treatment records from 89 patients were included. These patients continued SPT from 0.5-11.16 years. Of these patients, 92.1 % survived from tooth loss, while 61.8 % survived from CAL loss ≥2 mm compared to 1-year post-surgery. At the sites with residual pocket depth <5 mm, patients attending SPT >80 % had a significantly less percentage of teeth with CAL loss ≥2 mm compared to 1-year post-surgery than those attending SPT <80 %. However, at the sites with residual pocket depth ≥5 mm, no significant difference in the percentage of teeth with CAL loss ≥2 mm was found between patients attending SPT >80 % or <80 %. Smoking, patient's compliance, and residual pocket depth after regenerative surgery were significantly associated with tooth loss. However, these factors were not significantly associated with CAL loss compared to baseline or 1-year post-surgery.

  6. Minimally Invasive Surgery Combined with Regenerative Biomaterials in Treating Intra-Bony Defects: A Meta-Analysis

    PubMed Central

    Zhang, Yuanyuan; Li, Wenyang; Song, Jinlin

    2016-01-01

    Background With the popularity of minimally invasive surgery (MIS) in periodontics, numerous publications have evaluated the benefits of MIS with or without various regenerative biomaterials in the treatment of periodontal intra-bony defects. However, it is unclear if it is necessary to use biomaterials in MIS. Thus, we conducted a meta-analysis of randomized clinical trials in patients with intra-bony defects to compare the clinical outcomes of MIS with regenerative biomaterials for MIS alone. Methods The authors retrieved English publications on relevant studies from Cochrane CENTRAL, PubMed, Medline, Embase, Clinical Evidence, and ClinicalTrails.gov (up to June 30, 2015). The main clinical outcomes were the reduction of probing pocket depths (PPDs), gain of clinical attachment level (CAL), recession of gingival margin (REC) and radiographic bone fill. Review Manager 5.2 (Cochrane Collaboration, Oxford, England) was used to calculate the heterogeneity and mean differences of the main clinical outcomes. Results In total, 464 studies in the literature were identified but only four were ultimately feasible. The results showed no significant difference regarding CAL gain (P = 0.32) and PPD reduction (P = 0.40) as well as REC increase (P = 0.81) and radiographic bone fill (P = 0.64) between the MIS plus biomaterials group and the MIS alone group. Conclusions The meta-analysis suggested no significant difference in treatment of intra-bony defects between the MIS plus biomaterials group and the MIS alone group, indicating that it is important to take costs and benefits into consideration when a decision is made about a therapeutic approach. There needs to be an in-depth exploration of the induction of intrinsic tissue healing of MIS without biomaterials to achieve optimal outcomes. PMID:26785405

  7. Treatment of intrabony defects using guided tissue regeneration or enamel matrix derivative: a 3-year prospective randomized clinical study.

    PubMed

    Crea, Alessandro; Dassatti, Leonardo; Hoffmann, Oliver; Zafiropoulos, Gregory-George; Deli, Giorgio

    2008-12-01

    The aim of this randomized, controlled, prospective clinical study was to compare guided tissue regeneration (GTR) to enamel matrix derivative (EMD) for the treatment of intrabony defects in patients with chronic advanced periodontitis. Forty (39 evaluable) 3-wall intrabony defects, each with a depth > or = 4 mm measured from the crest of the bony defect, were treated in 40 subjects with advanced chronic periodontitis. Regeneration of angular bone defects was induced using non-resorbable membranes (GTR group; n = 20) or EMD (EMD group; evaluable n = 19). Clinical parameters, including probing depth (PD), clinical attachment level (CAL), gingival recession, radiographic measurement of the defect depth, plaque index, and bleeding on probing, were measured at baseline and at 12 and 36 months following surgery. Twelve months after surgery, sites treated with GTR demonstrated a mean CAL gain of 2.5 +/- 1.2 mm and a mean reduction in PD of 3.5 +/- 1.2 mm compared to baseline. The corresponding outcomes at 36 months were 2.0 +/- 1.1 mm (CAL) and 3.2 +/- 1.1 mm (PD). Sites treated with EMD demonstrated a mean CAL gain of 2.9 +/- 1.4 mm and a mean reduction in PD of 3.5 +/- 1.4 mm at 12 months, with a mean CAL gain of 2.4 +/- 1.2 mm and a mean PD reduction of 3.1 +/- 1.4 mm at 36 months. The differences in PD reduction and CAL gain were statistically significant between the groups and for each time point compared to baseline. Attachment loss was seen in both groups between the 12- and 36-month observations. Measured radiographic bone fill was 57.0% +/- 21% at 12 months and 53.7% +/- 14.3% at 36 months in the GTR group compared to 50.5% +/- 19% at 12 months and 58.8% +/- 14.9% at 36 months in the EMD group. The treatment of intrabony defects in patients with chronic advanced periodontitis using GTR or EMD led to significantly improved clinical parameters. Tests of statistical significance demonstrated better results with EMD, although the absolute differences between

  8. Comparative study of two collagen membranes for guided tissue regeneration therapy in periodontal intrabony defects: a randomized clinical trial

    PubMed Central

    2014-01-01

    Purpose The purpose of this study was to assess and compare the clinical and radiographic outcomes of guided tissue regeneration therapy for human periodontal intrabony defects using two different collagen membranes: a porous nonchemical cross-linking collagen membrane (NC) and a bilayer collagen membrane (BC). Methods Thirty subjects were randomly assigned and divided into the following 3 groups: a test group (NC+BM), in which a NC was used with xenograft bone mineral (BM), a positive control group (BC+BM), in which a BC was used with xenograft BM, and a negative control group (BM), in which only xenograft BM was used. The following clinical measurements were taken at baseline and 3 months after surgery: plaque index, gingival index, probing pocket depth, gingival recession, and clinical attachment level. Radiographic analysis was performed at baseline, 1 week and 3 months after surgery. Results Membrane exposure was not observed in any cases. Significant probing depth reduction, attachment-level gain and bone fill were observed for both test and control groups compared to baseline at 3 months after surgery (P<0.05). However, there were no statistically significant differences in clinical improvement and radiographic bone fill between treatment protocols (P>0.05). Conclusions Within the limitations of this study, the results suggest that both NC and BC were comparable in terms of clinical and radiographic outcomes for the treatment of periodontal intrabony defects in human subjects. Graphical Abstract PMID:25177521

  9. Modulatory effects of Cissus quadrangularis on periodontal regeneration by bovine-derived hydroxyapatite in intrabony defects: exploratory clinical trial.

    PubMed

    Jain, Anurag; Dixit, Jaya; Prakash, Dhan

    2008-04-01

    The purpose of the present study was to clinically evaluate the efficacy of bovine-derived hydroxyapatite (HA) combined with Cissus quadrangularis (CQ), as compared to bovine-derived hydroxyapatite alone in the treatment of intrabony defects. Twenty patients with one intrabony defect each were selected for this study. After scaling and root planing, twenty sites were randomly selected to receive either a combination of bovine-derived HA and CQ (test group) or bovine-derived HA alone (control group). Baseline and 6-month surgical reentry measurements were taken and appropriate statistical analysis was performed. Favorable clinical results for both hard and soft tissue measurements were obtained for both groups when compared to baseline (p < 0.001), but there was no statistically significant difference for any of the measured clinical parameters between the two groups. The mean bone fill and percentage bone fill for bovine-derived HA was 2.7 +/- 0.82 mm and 63.2 +/- 17.8%, whereas for composite graft material it was 3.3 +/- 0.82 mm and 69.8 +/- 14.2%. Although composite graft material has shown a trend towards better performance, no statistically significant intergroup difference was found. Further studies are needed to establish CQ as a modulator in periodontal regenerative therapy.

  10. Healing of human intrabony defects following regenerative periodontal therapy with a bovine-derived xenograft and guided tissue regeneration.

    PubMed

    Sculean, A; Stavropoulos, A; Windisch, P; Keglevich, T; Karring, T; Gera, I

    2004-06-01

    The purpose of the present study was to histologically evaluate the healing of human intrabony defects following treatment with either a bovine-derived xenograft (BDX) and guided tissue regeneration (GTR) [BDX + GTR] or a bovine-derived xenograft mixed with collagen (BDX Coll) and GTR [BDX Coll + GTR]. Eight patients with chronic periodontitis and each with one very deep intrabony defect around a tooth scheduled for extraction were treated with either a combination of BDX + GTR (five patients) or with BDX Coll + GTR (three patients). The postoperative healing was uneventful in all eight cases. After a healing period of 6 months, the teeth or roots were extracted together with some of their surrounding soft and hard tissues and subsequently fixed in 10% buffered formalin. Following decalcification in EDTA, the specimens were embedded in paraffin and 8-microm histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were alternatively stained with hematoxylin and eosin, van Giesson's connective tissue stain or with the Ladevig's connective tissue staining method and examined under the light microscope. Generally, formation of new cementum with inserting collagen fibers was found in seven out of the eight treated cases, whereas in the remaining case (treated with BDX + GTR) the healing was characterized by formation of a long junctional epithelium along the debrided root surface and no formation of cementum or bone. In the specimens demonstrating periodontal regeneration the new cementum was always of a cellular type. In most cases, the graft particles were surrounded by bone. In some areas, the bone tissue around the graft particles was connected by perpendicularly inserting collagen fibers to the newly formed cementum on the root surface. The epithelium downgrowth stopped always at the most coronal part of the newly formed cementum. No remnants of the membrane material were observed in any of the biopsies

  11. A combined approach of enamel matrix derivative gel and autogenous bone grafts in treatment of intrabony periodontal defects. A case report.

    PubMed

    Leung, George; Jin, Lijian

    2003-04-01

    Enamel matrix derivative (EMD) has recently been introduced as a new modality in regenerative periodontal therapy. This case report demonstrates a combined approach in topical application of EMD gel (Emdogain) and autogenous bone grafts for treatment of intrabony defects and furcation involvement defects in a patient with chronic periodontitis. The seven-month post-surgery clinical and radiographic results were presented. The combined application of EMD gel with autogenous bone grafts in intrabony osseous defects resulted in clinically significant gain of attachment on diseased root surfaces and bone fill on radiographs. Further controlled clinical studies are required to confirm the long-term effectiveness of the combination of EMD gel and autogenous bone grafts in treatment of various osseous defects in subjects with chronic periodontitis.

  12. Clinical effects of nanocrystalline hydroxyapatite paste in the treatment of intrabony periodontal defects: a randomized controlled clinical study.

    PubMed

    Heinz, Bernd; Kasaj, Adrian; Teich, Marie; Jepsen, Søren

    2010-10-01

    The purpose of the present randomized controlled clinical study was to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a novel nanocrystalline hydroxyapatite (nano-HA) bone graft substitute. Fourteen patients with paired intrabony periodontal defects of ≥ 4 mm participated in this split-mouth design study. The defects in each subject were randomly selected to receive nano-HA paste in conjunction with papilla preservation flaps or papilla preservation flaps alone. Probing bone levels (PBL) from a customized acrylic stent and probing pocket depths (PPD) were measured at baseline and again 6 months following surgery. No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all patients. Both treatments resulted in significant improvements between baseline and 6 months (p < 0.05). At 6 months after therapy, the sites treated with nano-HA paste showed a reduction in mean PPD from 8.3 ± 1.2 to 4.0 ± 1.1 mm and a gain in PBL of 4.3 ± 1.4 mm, whereas in the control group, the mean PPD changed from 7.9 ± 1.2 mm to 5.0 ± 1.2 mm and PBL gain was 2.6 ± 1.4 mm. Results demonstrated statistically greater PPD reduction and PBL gain (p < 0.05) in the test group as compared with the control group. In conclusion, after 6 months, the treatment of intrabony periodontal defects with a nano-HA paste leads to significantly improved clinical outcomes when compared with papilla preservation flap surgery alone.

  13. The Effect of an Er,Cr:YSGG Laser in the Management of Intrabony Defects Associated with Chronic Periodontitis Using Minimally Invasive Closed Flap Surgery. A Case Series

    PubMed Central

    Hughes, Francis; Wadia, Reena; Eastman, Christie; Kontogiorgos, Elias; Low, Samuel

    2016-01-01

    Aims: This is an extended case series of patients treated with an Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser as an adjunct to scaling for the management of intrabony defects. Materials & methods: 46 patients with 79 angular intrabony defects associated with pocket depths of >5mm, and a mean age of 53 ± 9 years presenting with chronic periodontitis were included in the analysis. All patients underwent a localized minimally invasive closed flap surgery utilizing Er,Cr:YSGG laser therapy. Final radiographs and pocket depths were compared to pretreatment measurements with a time period of 8 ± 3 months. Results: Treatment resulted in significant overall pocket depth reduction. The mean pre-op probing depth was 8.1 ± 1.9mm, reducing to 2.4 ± 0.9mm post-treatment. Bony infill of the defects was visible radiographically and there was an increase in overall radiographic coronal osseous height compared to a pre-treatment baseline. Radiographs of 15 of the defects were available for further measurements after >12 months, and showed in these sites there was a significant reduction in intrabony defect depth, but no change in suprabony bone height. 9 of the 15 sites showed 50% or more, bony infill of the intrabony defect. Conclusions: The results demonstrate that the utilization of an Er,Cr:YSGG laser in a closed flap approach with chronic periodontitis may be of significant clinical benefit. Further studies using this laser surgical protocol are required to test these observations in well-designed randomized controlled trials. PMID:27721565

  14. The approximal bone height and intrabony defects in young adults, related to the salivary buffering capacity and counts of Streptococcus mutans and Lactobacilli.

    PubMed

    Wikner, S; Söder, P O; Frithiof, L; Wouters, F

    1990-01-01

    Using a computerized technique the bone height and prevalence of approximal periodontal intrabony defects were assessed on posterior bite-wing radiographs from 151 young adults. The results were related to the buffering capacity and counts of Streptococcus mutans and lactobacilli in whole stimulated saliva. The mean distance from the cement-enamel junction to the alveolar bone crest was greater in the high buffering group than in the low buffering group (p less than 0.05), and particularly in non-smokers (p less than 0.01). Intrabony defects were more common in the low buffering group (p less than 0.05) and in women (p less than 0.001).

  15. Expanded polytetrafluoroethylene and dental rubber dam barrier membranes in the treatment of periodontal intrabony defects. A comparative clinical trial.

    PubMed

    Paolantonio, M; D'Archivio, D; Di Placido, G; Tumini, V; Di Peppe, G; Del Giglio Matarazzo, A; De Luca, M

    1998-11-01

    As observed in previous case reports, dental rubber dam (DRD) can be utilized as a barrier membrane in the guided tissue regeneration (GTR) technique for the treatment of periodontal intrabony defects. The purpose of the present study was (1) to confirm the validity of DRD as a suitable material in regenerative procedures and (2) to compare, in a split-mouth clinical trial, the effectiveness of DRD-made membranes in the treatment of periodontal intrabony defects versus that of expanded polytetrafluoroethylene (e-PTFE) barriers. 22 systemically healthy non-smoker adult periodontitis patients (7 male, 15 female) aged between 35 to 58 years were selected for the study. In each patient, a couple of 2-3 wall intrabony defects, located in different quadrants, were treated by a GTR technique using DRD (test sites) and e-PTFE (control sites), respectively. Performing a strict control of the oral hygiene level and of the marginal gingival health during the whole period of study, clinical (pocket probing depth, PPD; probing attachment level, PAL; gingival recession, GR) and intrasurgical (depth of the defect's intraosseous component, IOC; level of the alveolar crest, ACL) parameters were recorded at baseline and at the 1-year re-entry procedure in each experimental site. Furthermore, the coronal level of the newly formed tissue from the base of the defect (NFTL) and the vertical bone gain (VBG) were calculated at the time of membrane removal and after the re-entry procedure respectively. Membranes were removed from both test and control sites after 5 weeks; however, exposure of the membrane always occurred in test sites whereas it was observed in only 6 out of 22 control sites, this fact leading to an incomplete coverage of the regenerated tissue by the gingival flap in 18 out of 22 test sites. In both test and control sites, a statistically significant improvement of clinical and intrasurgical parameters occurred at the end of the study period; however, a significantly

  16. Periodontal regeneration in intrabony defects after application of enamel matrix proteins with guided tissue regeneration: an experimental study in dogs.

    PubMed

    Onodera, Hiroko; Shibukawa, Yoshihiro; Sugito, Hiroki; Ota, Mikio; Yamada, Satoru

    2005-04-01

    The aim of this study was to evaluate the effects of enamel matrix proteins (EMP) at the early stage of wound healing in the periodontal tissues by a combination treatment with guided tissue regeneration (GTR). Intrabony defects were produced surgically at the distal aspects of both mandibles in six beagle dogs. At 12 weeks following the surgery, the defects were exposed using a full thickness mucoperiosteal flap procedure. Subsequently, the defects were treated by the following treatments: a control group treated with GTR alone, and an experimental group treated with a combination of GTR and EMP. After one, two, four and eight weeks of the treatment, the animals were sacrificed, and sections of the tissue were stained and evaluated microscopically. After one and two weeks, the proliferating cell nuclear antigen (PCNA)-positive cell ratios of the experimental group were significantly greater than that of the control group. After 2 and 4 weeks, new bone and new cementum formation in the experimental group were significantly greater than those in the control group (P < 0.05). However, after 8 weeks, no statistical difference was found between the two groups in new bone or cementum formation. The study results suggest that a maturation of periodontal ligament cells might contribute, during the early stage of periodontal healing, to stimulate a proliferation of periodontal ligament cells.

  17. Addition of enamel matrix derivatives to bone substitutes for the treatment of intrabony defects: A systematic review, meta-analysis and trial sequential analysis.

    PubMed

    Troiano, Giuseppe; Laino, Luigi; Zhurakivska, Khrystyna; Cicciù, Marco; Lo Muzio, Lorenzo; Lo Russo, Lucio

    2017-07-01

    In order to enhance clinical improvement of intrabony defects, the addition of enamel matrix derivatives (EMD) to bone substitues (BS) has been investigated. The aim of this systematic review is to figure out whether such a combination, in comparison to the treatment with BS alone has beneficial effects on the following outcomes: clinical attachment level (CAL) gain, probing depth (PD) reduction and recession (REC). Electronic databases (PUBMED, SCOPUS, EBSCO Host Research Databases and Web of Knowledge) were searched for randomized controlled trials in humans addressing the use of a combination of BS and EMD versus a control group with BS alone for the treatment of intrabony defects, with a minimum of 6 months of follow-up; meta-analysis and trial sequential analysis were then performed. From a total of 1,197 records screened by title and abstract, nine studies were read full-text and five out of them included in the meta-analysis. No significant differences have been demonstrated both for CAL gain, PD reduction and REC between test and control groups. In the treatment of intrabony defects, the addition of EMD to BS seems to be not beneficial in terms of CAL gain, PD reduction and REC changes. However, such results should be considered with caution because of the small number of studies included in the meta-analysis and their heterogeneity. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Entire Papilla Preservation Technique: A Novel Surgical Approach for Regenerative Treatment of Deep and Wide Intrabony Defects.

    PubMed

    Aslan, Serhat; Buduneli, Nurcan; Cortellini, Pierpaolo

    Primary wound closure and uneventful early wound stability over the biomaterials are the most critical elements of successful periodontal regeneration. Yet the surgical elevation of the interdental papilla to access deep and wide intrabony defects entails an impairment of the papillary blood supply that can result in difficult healing due to a lack of primary closure in the early healing period. This negative event might complicate the healing process, favoring bacterial contamination. A novel modified tunnel surgical technique designed to maintain the integrity of the interdental papilla is presented in this article, with the aim of providing an optimal environment for wound healing in regenerative procedures. Entire papilla preservation is described and applied in three different cases, in association with the use of a combination of bone substitutes and enamel matrix derivative for periodontal regeneration. The entire papilla preservation technique was successfully applied to the three selected cases, resulting in an uneventful postsurgical period and a substantial defect fill over the 8-month follow-up. This tunnel-like technique can be recommended for further research to support the success identified in this case series.

  19. Healing response to anorganic bone implantation in periodontal intrabony defects in dogs. Part I. Bone regeneration. A microradiographic study.

    PubMed

    Clergeau, L P; Danan, M; Clergeau-Guérithault, S; Brion, M

    1996-02-01

    The purpose of the present study was to explore the regenerative potential of anorganic bone plus collagen (AB-C) in experimental intrabony defects. Eight healthy female beagle dogs, 3 to 4 years old and weighing 15 to 16 kilos, were used. After extraction of the mandibular third premolars (P3), surgical defects were created and inflammation induced by placement of cotton and steel braids. Eight weeks later, the braids were removed. The experimental lesions thus obtained were either treated by plain flap curettage (group 1: control) or were, in addition, implanted with AB-C (group 2: experimental). Blocks of AB-C alone were observed by scanning electron microscopy (SEM). The results show that the surface of the particles have the characteristics of a bone tissue. These particles are gathered together with a fibrillar network. Six, 18, and 36 weeks postoperative (PO), non-decalcified specimens from both groups were examined histologically by contact microradiography. In group 1, no significant bone regeneration was observed at 6, 18, or 36 weeks PO. In group 2, trabeculae undergoing mineralization and circumscribing dense particles above the reference notch were seen at 6 weeks PO; 18 and 36 week specimens showed significant bone regeneration with more or less dense remaining particles. The periodontal ligament space was always clear and the only signs of ankylosis noticed were deep in the notch on one 18 week group 2 specimen and on one 36 week group 1 specimen.

  20. Healing, post-operative morbidity and patient perception of outcomes following regenerative therapy of deep intrabony defects.

    PubMed

    Tonetti, Maurizio S; Fourmousis, Ioannis; Suvan, Jeanie; Cortellini, Pierpaolo; Brägger, Urs; Lang, Niklaus P

    2004-12-01

    This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of enamel matrix derivatives (EMD). This article reports on early healing events, post-operative morbidity and patient perceptions of the surgical outcomes. One hundred and seventy-two patients with advanced chronic periodontitis and at least one intrabony defect of > or =3 mm were recruited in 12 centres in seven countries (European Research Group on Periodontology (ERGOPERIO)). Papilla preservation flaps were used to obtain access and primary closure. After debridement, and root conditioning, EMD was applied in the test subjects, and omitted in the controls. Healing was monitored 1, 2, 3, 4, 6 and 12 weeks after surgery. During the first 12 weeks of healing, supracrestal soft-tissue density was evaluated with a computer-assisted densitometric image analysis system (CADIA) using underexposed radiographs taken on a subset of 34 patients. Patient perceptions were evaluated with a questionnaire immediately after the procedure, at suture removal 1 week later and at 1 year. Subjects reported little intraoperative or post-operative pain or discomfort for both test and controls. Twenty-four percent of controls and 30% of tests (p=0.64) reported a degree of interference with daily activities for an average of 3 and 3.5 days, respectively. Post-surgical edema was noted in 25% of tests and 28% of controls. Wound dehiscence in the interdental portion of the flap was uncommon (14% of tests and 12% of controls at week 1) and of limited size. Root sensitivity was the most frequent post-operative adverse event: it affected 45% of test and 35% of controls (p=0.55). Up to 6 weeks post-operatively, soft-tissue densities were significantly higher in subjects treated with EMD with respect to controls. One year after completion of the surgery, patients reported high levels of satisfaction with the outcomes

  1. Treatment of Intrabony Defects by DFDBA Alone or in Combination with PRP: A Split-Mouth Randomized Clinical and Three-Dimensional Radiographic Trial

    PubMed Central

    Shahidi, Shoaleh; Basri, Amar; Houshyar, Maral

    2015-01-01

    Objectives: The efficacy of adding platelet-rich plasma (PRP) to demineralized freeze-dried bone allograft (DFDBA) in order to improve the clinical and radiographic results obtained in treatment of deep periodontal intrabony defects has yet to be fully elucidated. Materials and Methods: This double blind, split-mouth randomized controlled clinical trial was conducted on 12 patients with two comparable bilateral intrabony defects. Each pair of defects was randomly treated with DFDBA+PRP (test) or DFDBA alone (control). Clinical attachment level (CAL), intrabony defect depth (IDD), distance from the stent to the alveolar crest and pocket depth (PD) as well as radiographic parameters including the radiographic defect depth, width and angulation were measured at baseline and six months post-operatively. The paired t-test was used to compare the pre and post-treatment values and the unpaired t-test compared the test and control groups. Results: The mean reductions in PD and CAL were 4.5 ±1.3 mm and 3.6±1.6 mm in sites treated with DFDBA+ PRP, respectively (P<0.01); these reductions were 4.1±1.4 mm and 3.5±1.3 mm, respectively in DFDBA group (P<0.01). Radiographic evaluation revealed 2.5±1.1 mm reduction in the radiographic defect depth in the test and 2.1±1.2 mm in the control sites. The defect angulation increased at both sites. Statistically, there were no significant differences between the two treatment modalities (P<0.01). Conclusion: This study showed that both treatments resulted in significant PD reduction, CAL gain and IDD reduction. Also, PRP failed to enhance the results obtained by DFDBA. PMID:27252760

  2. Preclinical Experiments on the Release Behavior of Biodegradable Nanofibrous Multipharmaceutical Membranes in a Model of Four-Wall Intrabony Defect

    PubMed Central

    Chen, Dave Wei-Chih; Lee, Fu-Ying; Liao, Jun-Yi; Hsiao, Chao-Ying; Chen, Jan-Kan

    2013-01-01

    Guided tissue regeneration (GTR) therapy has been widely used to regenerate lost periodontium from periodontal disease. However, in terms of regenerative periodontal therapy, a multidrug-loaded biodegradable carrier can be even more promising in dealing with periodontal disease. In the current study, we fabricated biodegradable nanofibrous collagen membranes that were loaded with amoxicillin, metronidazole, and lidocaine by an electrospinning technique. The in vitro release behavior and the cytotoxicity of the membranes were investigated. A four-wall intrabony defect was created in rabbits for in vivo release analysis. The bioactivity of the released antibiotics was also examined. The experimental results showed that the drug-loaded collagen membranes could provide sustainable release of effective amoxicillin, metronidazole, and lidocaine for 28, 56, and 8 days, respectively, in vivo. Furthermore, the bioactivity of the released antibiotics remained high, with average bioactivities of 50.5% for amoxicillin against Staphylococcus aureus and 58.6% for metronidazole against Escherichia coli. The biodegradable nanofibrous multipharmaceutical membranes developed in this study may provide a promising solution for regenerative periodontal therapy. PMID:22948881

  3. Platelet gel biotechnology applied to regenerative surgery of intrabony defects in patients with refractory generalized aggressive peridontitis. Case report.

    PubMed

    Mauro, S; Orlando, L; Panzoni, R; Orlando, P F

    2003-01-01

    Platelet gel biotechnology, a method which has all the components of "tissue engineering" techniques, potentiates the already known healing process of guided tissue regeneration procedures (GTR) by multiplying the number of molecules that activate the healing response and by grafting in the host site various cell types, among which stem cells. Here are reported cases of patients affected by refractory generalized aggressive periodontitis treated with the association GTR and platelet gel biotechnology to verify if the contribution of the gel would produce superior results than those obtained by surgery alone which had been previously applied to the same sites with negative results. Three patients in therapy from 4 to 11 years, already subjected to surgery (GTR) and antibiotic therapy, were reoperated with the adjunct of autologous platelet gel. At a distance of 15.2 months (range 11-17 months) the operated sites showed a reduction in probing pocket depth of 3.4 mm (range 2.8-4.8 mm) and a gain in clinical attachment level of 3.1 mm (range 3-3.5 mm). The association of platelet gel biotechnology with GTR in the surgical treatment of intrabony defects of refractory generalized aggressive periodontitis patients seems to produce results similar to those reported for patients with chronic adult periodontitis. The observations at 15.2 months indicate that there is a stability over time of the results in those sites where previous surgical therapy had shown relapse.

  4. Clinical and radiographical evaluation of a bioresorbable collagen membrane of fish origin in the treatment of periodontal intrabony defects: A preliminary study

    PubMed Central

    Santosh Kumar, B. B.; Aruna, D. R.; Gowda, Vinayak S.; Galagali, Sushama R.; Prashanthy, R.; Navaneetha, H.

    2013-01-01

    Background: Recently, there has been interest in non-mammalian collagen sources such as fish collagen in periodontal regeneration. In the present study, collagen barrier membrane of fish origin was assessed in the treatment of periodontal intrabony defects. Materials and Methods: Ten systemically healthy chronic periodontitis patients having a paired osseous defect in the mandibular posterior teeth were selected and randomly assigned to receive a collagen membrane (test) or open flap debridement (control) in a split mouth design. Clinical parameters such as Plaque index, Gingival bleeding index, Probing pocket depth, Relative attachment level, and Recession were recorded at baseline, 3, 6, and at 9 months, while radiographic evaluation was done to assess alveolar crestal bone level and percentage of defect fill at 6 and 9 months using autoCAD 2007 software. Student's t test (two-tailed, dependent) was used to find the significance of study parameters on continuous scale. Significance was set at 5% level of significance. Wilcoxon signed rank test was used to find the significance of percentage change of defect fill. Results: The comparison between the two groups did not show any statistically significant differences in the parameters assessed (P > 0.05) but, within each group, clinical parameters showed statistically significant differences from baseline to 9 months (P < 0.05). Conclusion: Within the limits of the study, it can be inferred that no significant differences were found either by using collagen membrane of fish origin or open flap debridement in the treatment of periodontal intrabony defects. PMID:24174757

  5. Efficacy of platelet rich fibrin in the treatment of human intrabony defects with or without bone graft: A randomized controlled trial

    PubMed Central

    Chandradas, Nikhil D.; Ravindra, Shivamurthy; Rangaraju, Vivekananda M.; Jain, Sheetal; Dasappa, Shivaprasad

    2016-01-01

    Aim: To evaluate the efficacy of platelet rich fibrin (PRF) with or without bone graft [demineralized bone matrix (DBM) graft] in the treatment of intrabony defects based on clinical and radiographic parameters. Materials and Methods: Thirty six intrabony defects in 36 patients were randomly divided into three different groups and were treated with group A (PRF with DBM) or group B (PRF alone) or group C [open flap debridement (OFD)]. Clinical parameters such as plaque index (PI), gingival index (GI), probing depth (PD), relative attachment level (RAL), and gingival recession (GR) were assessed at baseline and 9 months postoperatively; radiographic parameters such as linear bone growth (LBG) and percentage in bone fill (%BF) were calculated by using the image analysis software. Comparisons of groups were analyzed using Kruskal–Wallis analysis of variance test. Pair-wise comparison of groups was done by Mann-Whitney U test. Results: Mean PD reduction and RAL gain were greater in group A (4.25 ± 1.48, 3.92 ± 0.90) and group B (3.82 ± 0.75, 3.27 ± 0.65) than control (3.00 ± 1.21, 2.25 ± 0.62). Furthermore, statistically significant improvement in LBG and %BF was found in group A (3.47 ± 0.53, 61.53 ± 4.54) compared to group B (2.55 ± 0.61, 49.60 ± 14.08) and group C (1.21 ± 0.80, 24.69 ± 15.59). Conclusions: The study demonstrated that PRF improves clinical and radiological parameters compared to OFD alone in intrabony defects. Addition of DBM enhances the effects of PRF in RAL gain and radiographic defect fill. PMID:27652249

  6. Clinical and Radiologic Evaluation of Regenerative Potential of NHA Paste and DBM in the Treatment of Periodontal Intra-bony Defects -A Randomized Control Trial

    PubMed Central

    Jain, Deepti; Gupta, Bharat; Sharma, Saurabh; Juneja, Saurabh; Juneja, Manjushree; Sharma, Shruti; Patil, Neha

    2016-01-01

    Introduction Previous studies have shown that Hydroxyapatite (HA) has shown good results in the treatment of intra-osseous periodontal defects. A newer variety of HA has been designed over a period of research which has nano-sized particles and is availed in a paste consistency called Nanocrystalline Hydroxyapatite paste (NHA paste). This variation in size and surface area of NHA paste can provide better results when used in intra-bony defects. Aim The purpose of this study was to compare the clinical and radiographic outcomes obtained with usage of NHA paste to those obtained with Demineralized Bone Matrix (DBM) in the treatment of periodontal intra-bony defects. Material and Methods A clinical trial was carried out for a period of 12 months. A total of 26 intra-bony defects in 10 patients were divided into experimental and control sites. The experimental sites were debrided and grafted with NHA paste. The control sites were debrided and grafted with DBM-Xenograft. Probing Depth, Clinical Attachment Level (DCAL) and Gingival Margin (GM) position were recorded at baseline 3, 6, 9 and 12 months. Standardized radiographs were also documented at these recalls. The results were averaged (mean± standard deviation) for each parameter and Student t-test was used to determine intra-group statistical difference and One way analyses of variance (ANOVA) to test the difference between groups using Excel and SPSS (SPSS Inc, Chicago) software packages. Results On completion of 12 months, the mean percentage of PD reduction achieved in the experimental and control sites was 67.45% and 69.03% respectively (p<0.05). The mean percentage of gain achieved in CAL was 63.58% and 61.42% in the experimental and control sites respectively (p<0.05). Gingival recession was seen to be non-significant in the experimental and control sites. The mean percentage of bone fill in the control group obtained was 48.16% where as the percentage of bone fill obtained in the experimental group was 48

  7. Clinical outcomes of guided tissue regeneration with Atrisorb membrane in the treatment of intrabony defects: a 3-year follow-up study.

    PubMed

    Sakallioglu, Umur; Yavuz, Umit; Lütfioglu, Müge; Keskiner, Ilker; Açikgöz, Gökhan

    2007-02-01

    In this controlled clinical trial, initial and long-term treatment outcomes of guided tissue regeneration (GTR) were investigated for a synthetic absorbable membrane (Atrisorb) in intrabony defects. Eighteen defects in 16 patients received GTR with Atrisorb (test), with the membrane applied by an indirect method, and 15 defects in 15 patients were treated with open flap debridement (control). Probing pocket depth (PPD), gingival recession (GR), clinical attachment level (CAL), and linear alveolar bone level (ABL) were recorded at baseline and at 1 and 3 years following the treatment procedures and were assessed as the therapeutic outcome parameters. Both groups demonstrated significant PPD reduction and CAL and ABL gain after 1 year. Among these parameters, alterations in PPD and CAL were statistically significantly greater in the test group than the control group 1 year postsurgery. No significant changes were noted in the parameters of the first year between and within the study groups after 3 years. The results suggest that GTR performed with Atrisorb membrane via an indirect application method may provide favorable clinical outcomes for intrabony defects, and these outcomes may be maintained at least as well as open flap debridement over an extended period.

  8. Periodontal Regeneration of 1-, 2-, and 3-Walled Intrabony Defects Using Accell Connexus Versus Demineralized Freeze-Dried Bone Allograft: A Randomized Parallel Arm Clinical Control Trial

    DTIC Science & Technology

    2013-06-01

    PERIODONTAL  REGENERATION  OF  1-­‐,  2-­‐,  AND  3-­‐WALLED  INTRABONY  DEFECTS  USING  ACCELL   CONNEXUS... Periodontics  Graduate  Program   Naval  Postgraduate  Dental  School   Uniformed  Services  University  of  the...Peter Bertrand, CAPT (ret), DC, USN Chairman, Periodontics Department Director, Periodontics Dept Glenn Munro, CAPT, DC, USN Dean, Naval Postgraduate

  9. Five-year results of guided tissue regeneration in combination with deproteinized bovine bone (Bio-Oss) in the treatment of intrabony periodontal defects: a case series report.

    PubMed

    Stavropoulos, Andreas; Karring, Thorkild

    2005-12-01

    The aim of this study was to report on the clinical and radiographic results 5 years following treatment of intrabony defects with guided tissue regeneration (GTR) in combination with deproteinized bovine bone (DBB) (Bio-Oss). Fifteen patients, with at least one intrabony periodontal defect with probing pocket depth (PPD)>or=7 mm and radiographic presence of an intrabony component (IC)>or=4 mm, were treated with a PLA/PGA bioabsorbable membrane. Prior to placement of the membrane, the defect was filled with DBB impregnated with gentamicin sulfate 2 mg/ml. Standardized intraoral radiographs were taken prior to treatment and at the control examinations after 1 and 5 years. At baseline, the average PPD was 9.2+/-1.1 mm, and the average probing attachment level (PAL) was 10.1+/-1.6 mm; the radiographic bone level (RBL) was 10.4+/-2.45 mm, and an IC of 6.2+/-2.3 mm was present. One year after membrane placement, treatment had resulted in a PAL gain of 3.8+/-1.8 mm, a residual PPD of 4.2+/-1.3 mm, an RBL gain of 4.7+/-2.0 mm, and a residual IC of 2.1+/-1.2 mm. At the 5-year examination, two patients did not show up, and two patients had lost the treated tooth. However, both teeth were endodontically treated, and progressive periodontal destruction might not necessarily have been the reason for extraction. At the 5-year control (11 patients), the PAL gain was 4.1+/-1.6 mm, and the residual PPD was 4.6+/-1.2 mm; an RBL gain of 4.9+/-2.7 mm and a residual IC of 1.8+/-0.8 mm were observed. Statistically significant clinical improvements had occurred between baseline and the 1- and 5-year controls, whereas there were no significant differences between the 1- and 5-year results. The results of GTR with bioabsorbable membranes in combination with Bio-Oss in the treatment of periodontal intrabony defects are basically stable on a long-term basis.

  10. Comparative Evaluation of Platelet-Rich Fibrin Biomaterial and Open Flap Debridement in the Treatment of Two and Three Wall Intrabony Defects

    PubMed Central

    Ajwani, Himanshu; Shetty, Sharath; Gopalakrishnan, Dharmarajan; Kathariya, Rahul; Kulloli, Anita; Dolas, R S; Pradeep, A R

    2015-01-01

    Background: Platelet-rich concentrates are the most widely used regenerative biomaterials. Stimulation and acceleration of soft and hard tissue healing are due to local and continuous delivery of growth factors and proteins, mimicking the needs of the physiological wound healing and reparative tissue processes. This article aims to evaluate the clinical efficacy of open flap debridement (OFD) with or without platelet-rich fibrin (PRF) in the treatment of intrabony defects. Materials and Methods: Twenty subjects with forty intrabony defects were treated with either autologous PRF with open-flap debridement (test, n = 20) or open-flap debridement alone (control, n = 20). Soft tissue parameters included: Plaque index, sulcus bleeding index, probing depth, relative attachment level and gingival marginal level (GML). The hard tissue parameters included-distances from: Cement enamel junction to the base of the defect (CEJ-BOD): Alveolar crest to the base of the defect (AC-BOD): And CEJ to AC. The parameters were recorded at baseline and at 9 months postoperatively calculated using standardized radiographs by image-analysis software. Results: Statistically significant (0.005*) intragroup improvements were seen with all the hard and soft parameters in both test and control groups, except for GML. Statistically significant improvements were seen with the mean defect fill (CEJ-BOD and AC-BOD) (P = 0.003*) when intergroup comparisons were made. Conclusions: Adjunctive use of PRF with OFD significantly improves defect fill when compared to OFD alone. PRF has consistently been showing regenerative potential; it is simple, easy and inexpensive biomaterial compared with bone grafts. PMID:25954068

  11. Periodontal Regeneration Of 1-, 2-, and 3-Walled Intrabony Defects Using Accell Connexus (registered trademark) Versus Demineralized Freeze-Dried Bone Allograft: A Randomized Parallel Arm Clinical Control Trial

    DTIC Science & Technology

    2015-06-01

    PERIODONTAL REGENERATION OF 1-, 2-, AND 3-WALLED INTRABONY DEFECTS USING ACCELL CONNEXUS® VERSUS DEMINERALIZED FREEZE- DRIED BONE ALLOGRAFT: A...the Faculty of the Periodontics Graduate Program Naval Postgraduate Dental School Uniformed Services University of the Health Sciences in partial...June 2015 graduation. Thesis Committee: Matthew B. Miller, CDR, DC, USN Program Director, Periodontics Department Thu Getka, CAPT, DC, USN

  12. [Treatment of localized intrabony periodontal defects with enamel matrix derivative (Emdogain). Case series].

    PubMed

    Szatmári, Péter; Gera, István

    2014-03-01

    The solitary vertical or horisonto-vertical bone lesions are mainly characteristic of aggressive periodontitis. Only a combined conservative-surgical approach can result in predictable healing. From the early 50's basically two surgical techniques were used for correcting vertical bony defects. The so called bone resective techniques combined with apically positioned flap resulted in the flattening of the bone contour by removing substantial amount of alveolar bone but compromising the periodontal support of the neighboring teeth. The other surgical approach was the facilitation of the reformation of new periodontal attachment and bone with or without bone grafting. Since the mid 80's the gold standard in the therapy of deep vertical bony defects is the guided tissue regeneration (GTR), although an alternative approach has also been developed using different growth and differentiation factors promoting periodontal wound healing. Today in the clinical practices both in periodontal osseous and mucogingival surgeries the most widely used biological factor is the amelogenin and its commercially available product the Enamel Matrix Derivative (Emdogain). With the presented five solitary horisonto-vertical bony defects of three patients the possibilities and the late results are presented that could have been achieved with the application of EMD and thorough postoperative follow-up. The clinical results were comparable to the current data presented by articles in peer reviewed periodontal journals.

  13. Comparative Evaluation of Bioactive Synthetic NovaBone Putty and Calcified Algae-derived Porous Hydroxyapatite Bone Grafts for the Treatment of Intrabony Defects

    PubMed Central

    Bembi, Sumit; Mago, Jyoti; Baweja, Gurpreet Kaur; Baweja, Parvinder Singh

    2016-01-01

    Introduction To compare and evaluate clinically and radio-graphically the bone regeneration and the amount of bone fill in intrabony component of periodontal osseous defects through the osteoconductive and osteostimulative effect of bioactive synthetic NovaBone Putty - CMF and osteoconductive effect of calcified algae-derived porous hydroxyapatite Frios® Algi-pore® bone grafts. Materials and methods Twenty-two sites in 11 patients, within the age range of 25 to 60 years, showing intrabony defects were selected according to split mouth design and divided into group I (Frios® Algipore®) and group II (NovaBone Putty - CMF). All the selected sites were assessed with the clinical and radiographic parameters like plaque index, gingival index (full mouth and site specific), sulcus bleeding index, probing pocket depth, clinical attachment level, gingival recession, and radiographic bone fill. All the clinical and radiographic parameter values obtained at different intervals (baseline, 3, and 6 months) were subjected to statistical analysis. Results A statistically significant reduction in pocket depth of 2.55 ± 0.52 mm (group I), 2.64 ± 0.67 mm (group II) and gain in clinical attachment level of 7.55 ± 1.44 mm (group I), 7.55 ± 2.38 mm (group II) were recorded at the end of the study. A slight increase in gingival recession was observed. The mean percentage change in amount of radiographic bone fill of group II (71.34%) was more than group I (61.93%). Conclusion Both NovaBone Putty - CMF and Frios® Algipore® improve healing outcomes and lead to a reduction of probing depth, a resolution of osseous defects, and a gain in clinical attachment, but radiographic observation found better results with NovaBone Putty. How to cite this article Bembi NN, Bembi S, Mago J, Baweja GK, Baweja PS. Comparative Evaluation of Bioactive Synthetic NovaBone Putty and Calcified Algae-derived Porous Hydroxyapatite Bone Grafts for the Treatment of Intrabony Defects. Int J Clin Pediatr

  14. Clinical and radiographic evaluation of intra-bony defects in localized aggressive periodontitis patients with platelet rich plasma/hydroxyapatite graft: A comparative controlled clinical trial

    PubMed Central

    Gupta, Geeti

    2014-01-01

    Background: Aggressive periodontitis is a characterized by rapid attachment loss, bone destruction and familial aggregation. Platelet-rich plasma (PRP) has been proposed to promote regeneration of the lost periodontal tissues. The aim of this study was to evaluate and compare the efficacy of PRP combined with hydroxyapatite (HA) graft in the treatment of intra-bony defects in localized aggressive periodontitis (L-AgP) patients. Materials and Methods: Ten L-AgP patients having bilateral intra-bony defect ≥2 mm and probing depth (PD) ≥6 mm were randomly treated either with the PRP/HA graft or HA graft alone. The clinical (plaque control record, bleeding on probing index, PD, and relative attachment level [RAL]), and radiographic parameters (size of the bone defect) were recorded pre- and post-operatively at 3, 6, and 12 months. Results: After 12 months, for both maxillary and mandibular arches, the mean PD decrease was significantly more (P < 0.05) for the test group than the control group (3.2 mm vs. 1.9 mm and 3.6 mm vs. 1.9 mm, respectively). Furthermore, the mean RAL decrease in both maxillary and mandibular arches was significantly more (P < 0.05) for the test group than the control group (3.0 mm vs. 1.2 mm and 3.1 mm vs. 1.4 mm, respectively). Radiographically, the test group showed significantly more defect fill as compared with the control group. Conclusion: Both treatments provided significant improvements in clinical and radiographic parameters in a 12-month postoperative period. PRP/HA group presented superior results regarding PD reduction, clinical attachment gain and radiographic bone fill than HA group. PMID:25395757

  15. Ten-year results following treatment of intrabony defects with an enamel matrix protein derivative combined with either a natural bone mineral or a β-tricalcium phosphate.

    PubMed

    Döri, Ferenc; Arweiler, Nicole B; Szántó, Erika; Agics, Anikó; Gera, István; Sculean, Anton

    2013-06-01

    The purpose of the present study is to evaluate the 10-year results following treatment of intrabony defects treated with an enamel matrix protein derivative (EMD) combined with either a natural bone mineral (NBM) or β-tricalcium phosphate (β-TCP). Twenty-two patients with advanced chronic periodontitis and displaying one deep intrabony defect were randomly treated with a combination of either EMD + NBM or EMD + β-TCP. Clinical evaluations were performed at baseline and at 1 and 10 years. The following parameters were evaluated: plaque index, bleeding on probing, probing depth, gingival recession, and clinical attachment level (CAL). The primary outcome variable was CAL. The defects treated with EMD + NBM demonstrated a mean CAL change from 8.9 ± 1.5 mm to 5.3 ± 0.9 mm (P <0.001) and to 5.8 ± 1.1 mm (P <0.001) at 1 and 10 years, respectively. The sites treated with EMD + β-TCP showed a mean CAL change from 9.1 ± 1.6 mm to 5.4 ± 1.1 mm (P <0.001) at 1 year and 6.1 ± 1.4 mm (P <0.001) at 10 years. At 10 years two defects in the EMD + NBM group had lost 2 mm, whereas two other defects had lost 1 mm of the CAL gained at 1 year. In the EMD + β-TCP group three defects had lost 2 mm, whereas two other defects had lost 1 mm of the CAL gained at 1 year. Compared with baseline, at 10 years, a CAL gain of ≥3 mm was measured in 64% (i.e., seven of 11) of the defects in the EMD + NBM group and in 82% (i.e., nine of 11) of the defects in the EMD + β-TCP group. No statistically significant differences were found between the 1- and 10-year values in either of the two groups. Between the treatment groups, no statistically significant differences in any of the investigated parameters were observed at 1 and 10 years. Within their limitations, the present findings indicate that the clinical improvements obtained with regenerative surgery using EMD + NBM or EMD + β-TCP can be maintained over a period of 10 years.

  16. Five-year results evaluating the effects of platelet-rich plasma on the healing of intrabony defects treated with enamel matrix derivative and natural bone mineral.

    PubMed

    Döri, Ferenc; Arweiler, Nicole; Húszár, Tamás; Gera, István; Miron, Richard J; Sculean, Anton

    2013-11-01

    Regenerative periodontal surgery using the combination of enamel matrix derivative (EMD) and natural bone mineral (NBM) with and without addition of platelet-rich plasma (PRP) has been shown to result in substantial clinical improvements, but the long-term effects of this combination are unknown. The goal of this study was to evaluate the long-term (5-year) outcomes after regenerative surgery of deep intrabony defects with either EMD + NBM + PRP or EMD + NBM. Twenty-four patients were included. In each patient, one intrabony defect was randomly treated with either EMD + NBM + PRP or EMD + NBM. Clinical parameters were evaluated at baseline and 1 and 5 years after treatment. The primary outcome variable was clinical attachment level (CAL). The sites treated with EMD + NBM + PRP demonstrated a mean CAL change from 10.5 ± 1.6 to 6.0 ± 1.7 mm (P <0.001) at 1 year and 6.2 ± 1.5 mm (P <0.001) at 5 years. EMD + NBM-treated defects showed a mean CAL change from 10.6 ± 1.7 to 6.1 ± 1.5 mm (P <0.001) at 1 year and 6.3 ± 1.4 mm (P <0.001) at 5 years. At 1 year, a CAL gain of ≥4 mm was measured in 83% (10 of 12) of the defects treated with EMD + NBM + PRP and in 100% (all 12) of the defects treated with EMD + NBM. Compared to baseline, in both groups at 5 years, a CAL gain of ≥4 mm was measured in 75% (nine of 12 in each group) of the defects. Four sites in the EMD + PRP + NBM group lost 1 mm of the CAL gained at 1 year. In the EMD + NBM group, one defect lost 2 mm and four other defects lost 1 mm of the CAL gained at 1 year. No statistically significant differences in any of the investigated parameters were observed between the two groups. Within their limits, the present results indicate that: 1) the clinical outcomes obtained with both treatments can be maintained up to a period of 5 years; and 2) the use of PRP does not appear to improve the results obtained with EMD + NBM.

  17. Nano-crystalline hydroxyapatite bone graft combined with bioresorbable collagen membrane in the treatment of periodontal intrabony defects: A randomized controlled clinical trial

    PubMed Central

    Singh, Vijendra P.; Nayak, Dilip G.; Uppoor, Ashita S.; Shah, Dipen

    2012-01-01

    Aim: To evaluate the clinical outcome of nanocrystalline hydroxyapatite (NcHA) bonegraft (Sybograf®) in combination with collagen membrane (PerioCol®) compared with open flap debridement (OFD) only in the treatment of intrabony periodontal defects. Materials and Methods: Eighteen intrabony defects in 16 systemically healthy patients aged between 25-65 years, were randomly assigned to test and control groups. The Plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site NcHA bone graft and collagen membrane was placed, whereas at the control site only, OFD was done. Recall appointments were made at 7th day, 1st month, 3rd month, and 6th month. Results: The data were subjected to statistical analysis using the Mann-Whitney ‘U’ Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm and CAL gain was 2.78±1.09 mm. In the test group, the mean PPD reduction of 4.33±0.5 mm and mean gain in CAL was 3.78±0.66 mm at 6 months. The mean increase in gingival recession was 0.55±0.72 mm in test and 0.44±0.52 mm in control group. Conclusion: The NcHA bone graft in combination with collagen membrane demonstrated better clinical outcomes compared with OFD alone. PMID:23493628

  18. Periodontal tissue reaction to customized nano-hydroxyapatite block scaffold in one-wall intrabony defect: a histologic study in dogs

    PubMed Central

    Lee, Jung-Seok; Park, Weon-Yeong; Cha, Jae-Kook; Jung, Ui-Won; Kim, Chang-Sung; Lee, Yong-Keun

    2012-01-01

    Purpose This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral 4×4×5 mm (buccolingual width×mesiodistal width×depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation. PMID:22586523

  19. Comparison of 2 regenerative procedures--guided tissue regeneration and demineralized freeze-dried bone allograft--in the treatment of intrabony defects: a clinical and radiographic study.

    PubMed

    Parashis, A; Andronikaki-Faldami, A; Tsiklakis, K

    1998-07-01

    The purpose of this study was to compare clinically and radiographically the effectiveness of guided tissue regeneration (GTR), using a bioabsorbable polylactic acid softened with citric acid ester barrier and commercially available demineralized freeze-dried bone allograft (DFDBA) in the treatment of 2- and 3-wall intrabony defects. Twelve patients each with one treated defect comprised each group. Conservative treatment was completed 2 to 4 months prior to surgery. Clinical measurements, plaque index, gingival index, probing depths (PD), clinical attachment levels (CAL) and recession (REC), were comparable in both groups at baseline. They were repeated at 12 months. Surgical measurements were also comparable at baseline in both groups. In the GTR group, at baseline the mean distance between the cemento-enamel junction (CEJ) and base of the defect was 12.3 +/- 2.9 mm and in the DFDBA group 11.3 +/- 1.8 mm. The defect depth was 6.3 +/- 2.0 mm and 5.4 +/- 1.3 mm, respectively. Radiographs were taken at baseline and 12 months later and compared using non-standardized digital subtraction radiography. In the GTR group, mean PD decreased from 7.9 +/- 2.5 mm to 3.5 +/- 1.4 mm and mean CAL from 10.8 +/- 2.8 mm to 7.0 +/- 1.6 mm, the differences being statistically significant (P = 0.002), while REC increased from 2.9 +/- 1.2 mm to 3.5 +/- 1.1 mm. In the DFDBA group, mean PD decreased from 7.1 +/- 1.1 mm to 3.5 +/- 1.1 mm and mean CAL from 9.8 +/- 1.5 mm to 6.6 +/- 1.7 mm (P = 0.002), while REC increased from 2.8 +/- 1.0 mm to 3.1 +/- 1.2 mm. No significant differences were found when the clinical results of the 2 groups were compared. Radiographic differences between the baseline and reconstructed images 12 months later were observed in both groups. Mean crestal bone resorption was 15.3 +/- 22.5% in the GTR group and 10.4 +/- 31.8% in the DFDBA group, and mean improvement in the distance between the CEJ and the base of the defect was 22.8 +/- 18.1% in the GTR group and 15

  20. Clinical and radiographic evaluation of Nano-crystalline hydroxyapatite bone graft (Sybograf®) in combination with bioresorbable collagen membrane (Periocol®) in periodontal intrabony defects

    PubMed Central

    Singh, Vijendra P.; Nayak, Dilip G.; Uppoor, Ashita S.; Shah, Dipen

    2012-01-01

    Background: Nanosized ceramics may represent a promising class of bone graft substitutes due to their improved osseointegrative properties. Nanocrystalline Hydroxyapatite (NcHA) bind to bone and stimulate bone healing by stimulation of osteoblast activity. The present study aims to explore the clinical and radiographical outcome of NcHA bonegraft (Sybograf®) with collagen membrane (Periocol®), in comparison with open flap debridement (OFD), in the treatment of intrabony periodontal defects. Materials and Methods: A parallel-group, randomized, controlled clinical trial was designed to conduct the study. Eighteen intrabony defects in 14 systemically healthy patients aged between 25 to 65 years were randomly assigned to test and control group. The plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site, NcHA bone graft and collagen membrane was placed, whereas at the control site, only OFD was done. Recall appointments were made at 7 days, 30 days, and then at 3 months and 6 months. Results: The data were subjected to statistical analysis using the Mann-Whitney ‘U’ Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm (P=0.007) and CAL gain was 2.77±1.09 mm (P=0.007). In the test group, the mean PPD reduction of 4.33±0.5 mm (P=0.006) and mean gain in CAL was 3.77±0.66 mm (P=0.006) at 6 months. The mean increase in REC was 0.55±0.72 mm (P=0.025) in test, and 0.44±0.52 mm (P=0.046) in control group. The mean gain in radiographic defect fill was 2.07±0.67 mm (P=0.008) in test and 0.91±0.21 mm (P=0.007) in control group. Conclusion: The nanocrystalline hydroxyapatite bone graft in combination with collagen membrane demonstrated clinical advantages beyond that achieved by OFD alone. PMID

  1. An evaluation of platelet-rich plasma without thrombin activation with or without anorganic bone mineral in the treatment of human periodontal intrabony defects.

    PubMed

    Rodrigues, Silvia V; Acharya, Anirudh B; Thakur, Srinath L

    2011-01-01

    The efficacy of platelet-rich plasma (PRP) in periodontal regeneration is not well understood and the definite clinical viability of blood derived platelets lacks clarity. Also, the use of thrombin for platelet activation is disputed. Hence, the purpose of this study was to evaluate the efficacy of blood derived platelets without thrombin activation, alone or in combination with bovine anorganic bone mineral (ABM), in the treatment of human periodontal intrabony defects. PRP was prepared using a simple tabletop centrifuge and activated using calcium chloride without the addition of thrombin. This PRP was used alone (in Group A) and in combination with bovine ABM (in Group B) in the treatment of human periodontal angular defects. Both the control and the test groups showed definite improvement in clinical parameters. On comparison, however, there was a statistically significant improvement in the probing pocket depths and relative attachment level in Group B over Group A at 3 and 6 months intervals, whereas at the end of 9 months this difference was not statistically significant. There was no statistically significant difference between the groups with respect to the relative defect depth. Within the limitations of this study and the type of PRP used, i.e. without thrombin mediated activation, it can be concluded that both PRP and PRP combined with bovine ABM results in significant clinical improvement. Albeit statistically insignificant, there is a preponderance of better clinical results with the addition of ABM to PRP. Further studies need to be carried out on a larger sample size to confirm the results of the present study.

  2. Clinical evaluation of regenerative potential of type I collagen membrane along with xenogenic bone graft in the treatment of periodontal intrabony defects assessed with surgical re-entry and radiographic linear and densitometric analysis

    PubMed Central

    Sowmya, N. K.; Tarun Kumar, A. B.; Mehta, D. S.

    2010-01-01

    Background and Objectives: The primary goal of periodontal therapy is to restore the tooth supporting tissues lost due to periodontal disease. The aim of the present study was to compare the efficacy of combination of type I collagen (GTR membrane) and xenogenic bone graft with open flap debridement (OFD) in treatment of periodontal intrabony defects. Materials and Methods: Twenty paired intrabony defects were surgically treated using split mouth design. The defects were randomly assigned to treatment with OFD + collagen membrane + bone graft (Test) or OFD alone (Control). The clinical efficacy of two treatment modalities was evaluated at 9 month postoperatively by clinical, radiographical, and intrasurgical (re-entry) parameters. The measurements included probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), bone fill (BF), bone density (BD) and intra bony component (INTRA). Results: The mean reduction in PD at 0–9 month was 3.3±0.82 mm and CAL gain of 3.40±1.51 mm occurred in the collagen membrane + bone graft (Test) group; corresponding values for OFD (Control) were 2.20±0.63 mm and 1.90±0.57 mm. Similar pattern of improvement was observed when radiographical and intra-surgical (re-entry) post operative evaluation was made. All improvement in different parameters was statistically significant (P< 0.01). Interpretation and Conclusion: Treatment with a combination of collagen membrane and bone graft led to a significantly more favorable clinical outcome in intrabony defects as compared to OFD alone. PMID:20922075

  3. Clinical and radiographic evaluation of the efficacy of platelet-rich plasma combined with hydroxyapatite bone graft substitutes in the treatment of intra-bony defects in maxillofacial region.

    PubMed

    DurmuŞlar, Mustafa Cenk; Alpaslan, Cansu; Alpaslan, Gökhan; Çakır, Melih

    2014-11-01

    The aim of this study is to evaluate the efficacy of platelet-rich plasma (PRP) clinically and radiographically when combined with bovine derived hydroxyapatite (HA) bone grafting materials and resorbable collagen membranes for the treatment of intra-bony defects frequently seen at the distal aspect of mandibular second molars following the surgical extraction of fully impacted mandibular wisdom teeth. Eighteen patients were scheduled for post-operative visits at 1, 3 and 6 months post-operatively, probing depths were measured and digital panoramic radiographs were taken. There were no significant differences on probing depths among two groups. Radiographic assessment also showed no significant difference among groups at 1st and 6th month intervals, while 3 months post-operatively the amount of radiographic density at the PRP side was significantly higher. Combined use of PRP and bovine-derived HA graft materials for the treatment of intra-bony defects might be an appropriate approach when the main goal is providing earlier bone regeneration.

  4. Surgical therapy of single peri-implantitis intrabony defects, by means of deproteinized bovine bone mineral with 10% collagen.

    PubMed

    Roccuzzo, Mario; Gaudioso, Luigi; Lungo, Marco; Dalmasso, Paola

    2016-03-01

    To evaluate the efficacy of a reconstructive surgical procedure in single peri-implantitis infrabony defects. Seventy-five patients with one peri-implantitis crater-like lesion with pocket depth (PD) ≥ 6 mm, were included. Each defect was assigned to one characteristic class, by an independent examiner. After implant decontamination, defects were filled with deproteinized bovine bone mineral with 10% collagen. At 1-year follow-up, four patients were lost and six implants removed. Treatment success, PD ≤ 5 mm and absence of suppuration/bleeding on probing (BOP), was obtained in 37 (52.1%) of the 71 implants examined. PD was significantly reduced by 2.92 ± 1.73 mm (p < 0.0001). BOP decreased from 71.5 ± 34.4% to 18.3 ± 28.6% (p < 0.0001). The mean number of deep pockets (≥ 6 mm) decreased from 3.00 ± 0.93 to 0.85 ± 1.35 (p < 0.0001). These results confirm the possibility to successfully treat peri-implantitis lesions. There is lack of evidence of whether or not the resolution of the peri-implant disease is associated with the defect configuration. Due to the fact that complete resolution does not seem a predictable outcome, the clinical decision on whether implants should be treated should be based on several patient related elements. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Comparative evaluation of the efficacy of synthetic nanocrystalline hydroxyapatite bone graft (Ostim®) and synthetic microcrystalline hydroxyapatite bone graft (Osteogen®) in the treatment of human periodontal intrabony defects: A clinical and denta scan study

    PubMed Central

    Kamboj, Monika; Arora, Ruchika; Gupta, Harinder

    2016-01-01

    Background: To evaluate the relative efficacy of synthetic nanocrystalline hydroxyapatite (HA) (Ostim®) and microcrystalline HA (Osteogen®) bone grafts in the treatment of human periodontal intrabony defects clinically and radiographically through denta scan. Materials and Methods: Ten chronic periodontitis patients with bilateral intrabony periodontal defects of ≥2 mm radiographic defect depth below 55 years of age were selected randomly and treated with synthetic nanocrystalline HA (Ostim®) or synthetic microcrystalline HA (Osteogen®) bone graft. Clinical parameters including probing depth (PD) and clinical attachment level (CAL) were measured preoperatively and postoperatively at 3 and 6 months for each of the defects using an occlusal acrylic stent. Radiographic parameters were measured with the help of denta scan preoperatively and postoperatively at 6 months. Results: At 6 months following therapy, the Osteogen® group showed a reduction in mean PD from 11.10 ± 1.663 to 8.50 ± 0.850 mm and a change in mean CAL from 6.30 ± 1.160 to 3.40 ± 0.516 mm, whereas in the Ostim® group, the mean PD decreased from 11.20 ± 0.919 to 8.30 ± 0.823 mm and mean CAL decreased from 6.10 ± 0.738 to 3.30 ± 0.483 mm. At 6 months following therapy, denta scan showed a reduction in mean intrabony defect depth in the Osteogen® group from 2.54 ± 0.786 to 1.01 ± 0.448 mm, whereas in the Ostim® group, it was 2.71 ± 0.650 mm to 1.12 ± 0.563 mm. Conclusion: It was concluded that both the HA bone grafts produced statistically significant reduction in pocket depth, in the depth of osseous lesion, and a statistically significant gain in attachment level, irrespective of their physico-chemical properties. PMID:28298825

  6. Effects of bone marrow-derived mesenchymal stem cells and platelet-rich plasma on bone regeneration for osseointegration of dental implants: preliminary study in canine three-wall intrabony defects.

    PubMed

    Yun, Jeong-Ho; Han, Sang-Hyun; Choi, Seong-Ho; Lee, Myung-Hyun; Lee, Sang-Jin; Song, Sun U; Oh, Namsik

    2014-07-01

    Tissue engineering has been applied to overcome the obstacles encountered with bone regeneration for the placement of dental implants. The purpose of this study was to determine the bone formation ability of human bone marrow-derived mesenchymal stem cells (BMMSCs) and platelet-rich plasma (PRP) when applied separately or together to the intrabony defect around dental implants with a porous hydroxyapatite (HA) scaffold. Standardized three-wall intrabony defects (4 × 4 × 4 mm) were created at the mesial of each dental implant site in four mongrel dogs. Defects were then grafted with the following materials: HA + BMMSCs (HS group), HA + PRP (HP group), HA + BMMSCs + PRP (HSP group), and HA scaffold alone (HA group). The level of bone formation (bone density) and osseointegration (bone-to-implant contact [BIC]) in bone defects around the implants were evaluated by histological and histometric analysis at 6 and 12 weeks after the placement of implants. HA, HS, HP, and HSP groups generally showed an increase in bone density and BIC between 6 and 12 weeks, except BIC in the HS group. Although no statistically significant differences were found among HA, HS, HP, and HSP groups (p > 0.05), the highest level of bone density and BIC were observed in the HSP group after the 12-week healing period. Furthermore, the level of bone maturation was higher in the HSP group than in the other groups as determined histologically. The findings of this preliminary study suggest that BMMSCs and PRP combined with HA scaffold may provide additional therapeutic effects on bone regeneration and improve osseointegration in bone defects around dental implants.

  7. Evaluation of moxifloxacin-hydroxyapatite composite graft in the regeneration of intrabony defects: A clinical, radiographic, and microbiological study

    PubMed Central

    Nagarjuna Reddy, Y. V.; Deepika, P. C.; Venkatesh, M. P.; Rajeshwari, K. G.

    2016-01-01

    Background: The formation of new connective periodontal attachment is contingent upon the elimination or marked reduction of pathogens at the treated periodontal site. An anti-microbial agent, i.e. moxifloxacin has been incorporated into the bone graft to control infection and facilitate healing during and after periodontal therapy. Materials and Methods: By purposive sampling, 15 patients with at least two contralateral vertical defect sites were selected. The selected sites in each individual were divided randomly into test and control sites according to split-mouth design. Test site received moxifloxacin-hydroxyapatite composite graft and control site received hydroxyapatite-placebo gel composite graft. Probing depth (PD) and Clinical attachment level (CAL) were assessed at baseline, 3, 6, 9, and 12 months. Bone probing depth (BPD) and hard tissue parameters such as amount of defect fill, percentage of defect fill, and changes in alveolar crest were assessed at baseline, 6, and 12 months. Changes in subgingival microflora were also assessed by culturing the subgingival plaque samples at baseline and at 3-month follow-up. The clinical, radiographic, and microbiological data obtained were subjected to statistical analysis using descriptive statistics, paired sample t-test, independent t-test, and contingency test. Results: On intragroup comparison at test and control sites, there was a significant improvement in all clinical and radiographic parameters. However, on intergroup comparison of the same, there was no statistically significant difference between test and control sites at any interval. Although test sites showed slightly higher amount of bone fill, it was not statistically significant. There was a significant reduction in the counts of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis at both sites from baseline to 3 months. In addition, there was a significant reduction at test sites as compared to control sites at 3-month follow-up (P

  8. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    SciTech Connect

    Anzai, Jun; Kitamura, Masahiro; Nozaki, Takenori; Nagayasu, Toshie; Terashima, Akio; Asano, Taiji; Murakami, Shinya

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  9. Additive Effect of Plasma Rich in Growth Factors With Guided Tissue Regeneration in Treatment of Intrabony Defects in Patients With Chronic Periodontitis: A Split-Mouth Randomized Controlled Clinical Trial.

    PubMed

    Ravi, Sheethalan; Malaiappan, Sankari; Varghese, Sheeja; Jayakumar, Nadathur D; Prakasam, Gopinath

    2017-09-01

    Periodontal regeneration can be defined as complete restoration of lost periodontal tissues to their original architecture and function. A variety of treatment modalities have been proposed to achieve it. Plasma rich in growth factors (PRGF) is a concentrated suspension of growth factors that promotes restoration of lost periodontal tissues. The objective of the present study is to assess the effect of PRGF associated with guided tissue regeneration (GTR) versus GTR only in the treatment of intrabony defects (IBDs) in patients with chronic periodontitis (CP). Patients with CP (n = 14) with 42 contralateral 2- and 3-walled defects were randomly assigned to test (PRGF+GTR) and control (GTR alone) treatment groups. Clinical and radiographic assessments performed at baseline and after 6 months were: 1) gingival index (GI), 2) probing depth (PD), 3) clinical attachment level (CAL), 4) radiologic defect depth, and 5) bone fill. Comparison of parameters measured at baseline and after 6 months showed mean PD reduction of 3.37 ± 1.62 mm in the control group (P <0.001) and 4.13 ± 1.59 mm in the test group (P <0.001). There was a significant difference in mean change in CAL (P <0.001) in the control group (5.42 ± 1.99) and the test group (5.99 ± 1.77). Mean change in GI was 1.89 ± 0.32 and 1.68 ± 0.58 in the control group and test group, respectively, and the difference was statistically significant (P <0.001). When compared between groups, clinical parameters did not show any statistically significant variations. Mean radiographic bone fill was 1.06 ± 0.81 and 1.0 ± 0.97 in the control group and test group, respectively. However, the difference was not statistically significant. PRGF with GTR, as well as GTR alone, was effective in improving clinical and radiographic parameters of patients with CP at the 6-month follow-up. There was no additive effect of PRGF when used along with GTR in the treatment of IBDs in patients with CP in terms of both clinical and

  10. Treatment of periodontal intrabony defects using β-TCP alone or in combination with rhPDGF-BB: a randomized controlled clinical and radiographic study.

    PubMed

    Maroo, Sneha; Murthy, K Raja V

    2014-01-01

    The need to increase the predictability of periodontal regeneration has encouraged clinicians and researchers to employ cell-stimulating proteins in combination with osteoconductive scaffolds, based on the principles of tissue engineering. The purpose of this clinical and radiographic study was to compare the regenerative potential of the combination of β-tricalcium phosphate (β-TCP) and recombinant human platelet-derived growth factor BB (rhPDGF-BB) in the grafting of intraosseous defects with the established technique of bone grafting with (β-TCP alone. A total of 30 sites from 15 patients with infrabony defects in two different quadrants were selected, and the sites were randomly divided into test sites (rhPDGF + β-TCP) and control sites (β-TCP alone) using a split-mouth design. Clinical parameters, including probing pocket depth, clinical attachment level, and gingival recession, were recorded at baseline, 6 months, and 9 months. Radiographic evaluation was carried out to evaluate defect fill, change in alveolar crest height, and percentage of defect fill at baseline, 6 months, and 9 months. Both the experimental groups showed statistically significant reduction in probing pocket depth and gain in clinical attachment level. On intergroup comparison, sites treated with rhPDGF + β-TCP demonstrated a significantly greater pocket depth reduction (P < .05) and greater gain in clinical attachment level (P < .01). Mean percentage defect fill was significantly greater in test sites as compared with control sites at 6 and 9 months (P < .01). rhPDGF + β-TCP-treated sites demonstrated a significant gain in mean alveolar crest height at 6 and 9 months (P < .05), while β-TCP-treated sites demonstrated crestal resorption. Both groups demonstrated potential in enhancing periodontal regeneration; however, on comparison between the two groups, the results obtained by rhPDGF + β-TCP were significantly better with respect to both clinical and radiographic parameters.

  11. Management of localized advance loss of periodontal support associated Grade II furcation and intrabony defect in chronic periodontitis patient through amalgamation of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules

    PubMed Central

    Salaria, Sanjeev Kumar; Ghuman, Simrat Kaur; Kumar, Saurabh; Sharma, Garima

    2016-01-01

    Periodontal disease is infectious, complex, multifactorial, chronic inflammatory disease of supporting periodontal tissues that not only alters the bone morphology but also leads to the reduction in bone height. Different types of bony deformities such as horizontal, vertical, craters, and furcation result from periodontal disease, but vertical and Grade II furcation defects are more amenable to regenerative periodontal therapy. The present case report describes the current concept of periodontal diagnosis and the clinical radiographical efficiency of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules graft combination in the management of localized advance osseous defects with respect to tooth number 36 in chronic periodontitis patient at 1 year postoperatively. PMID:27630511

  12. Biomimetic hydroxyapatite used in the treatment of periodontal intrabony pockets: clinical and radiological analysis

    PubMed Central

    Figliuzzi, Michele Mario; Giudice, Amerigo; Pileggi, Settimia; Scordamaglia, Francesco; Marrelli, Massimo; Tatullo, Marco; Fortunato, Leonzio

    2016-01-01

    Summary Aim Hydroxyapatite (PA) has a chemical composition and physical structure very similar to natural bone and therefore it has been considered to be the ideal biomaterial able to ensure a biomimetic scaffold to use in bone tissue engineering. The aim of this study is to clinically test hydroxyapatite used as osteoconductive biomaterial in the treatment of periodontal bone defects. Clinical and radiological evaluations were conducted at 6, 12 and 18 months after the surgery. Materials and methods Forty patients with 2- and 3-wall intrabony pockets were enrolled in this study. PPD, CAL, radiographic depth (RD) and angular defects were preoperatively measured. After surgery, patients were re-evaluated every 6 months for 18 months. Statistical analyses were also performed to investigate any differences between preoperative and postoperative measurements. Results Paired t-test samples conducted on the data obtained at baseline and 18 months after, showed significant (p<0.01) differences in each measurement performed. The role of preoperative RD was demonstrated to be a significant key factor (p<0.01). A relevant correlation between preoperative PPD and CAL gain was also found. Conclusions Within the limitations of this study, the absence of anatomical variables, except the morphology of the bone defect, emphasizes the importance of the proper surgical approach and the graft material used. PMID:27486507

  13. A comparative evaluation of bovine-derived xenograft (Bio-Oss Collagen) and type I collagen membrane (Bio-Gide) with bovine-derived xenograft (Bio-Oss Collagen) and fibrin fibronectin sealing system (TISSEEL) in the treatment of intrabony defects: A clinico-radiographic study

    PubMed Central

    Palachur, Deepthi; Prabhakara Rao, K. V.; Murthy, K. Raja V.; Kishore, D. Trinath; Reddy, M. Narendra; Bhupathi, Anitha

    2014-01-01

    Background and Objectives: The purpose of this study was to compare the efficacy of bovine-derived xenograft (Bio-Oss Collagen) and Type I collagen membrane (Bio-Gide) with bovine-derived xenograft (Bio-Oss Collagen) and fibrin fibronectin sealing system (TISSEEL) in the treatment of periodontal infrabony defects. Materials and Methods: Fourteen healthy patients in the age range of 20 to 60 years, showing bilateral or contralateral infrabony defects were selected. The defects were assigned randomly to Site A (bovine-derived xenograft [Bio-Oss Collagen] with bioresorbable Type I collagen membrane [Bio-Gide]) and Site B (fibrin fibronectin sealing system [TISSEEL] with bovine-derived xenograft [Bio-Oss Collagen]). The radiographic parameters were recorded at baseline, 6 months, and 9 months postoperatively. Results: All fourteen patients returned for recall at regular intervals till the completion of the study. Both the experimental groups showed clinically and radiographically statistically significant reduction in probing pocket depth and gain in clinical attachment level. Conclusion: Both groups showed potential for enhancing the periodontal regeneration with no statistically significant between the two groups; however, on comparison the Bio-Oss Collagen and TISSEEL group were slightly better. PMID:25024548

  14. A comparative evaluation of bovine-derived xenograft (Bio-Oss Collagen) and type I collagen membrane (Bio-Gide) with bovine-derived xenograft (Bio-Oss Collagen) and fibrin fibronectin sealing system (TISSEEL) in the treatment of intrabony defects: A clinico-radiographic study.

    PubMed

    Palachur, Deepthi; Prabhakara Rao, K V; Murthy, K Raja V; Kishore, D Trinath; Reddy, M Narendra; Bhupathi, Anitha

    2014-05-01

    The purpose of this study was to compare the efficacy of bovine-derived xenograft (Bio-Oss Collagen) and Type I collagen membrane (Bio-Gide) with bovine-derived xenograft (Bio-Oss Collagen) and fibrin fibronectin sealing system (TISSEEL) in the treatment of periodontal infrabony defects. Fourteen healthy patients in the age range of 20 to 60 years, showing bilateral or contralateral infrabony defects were selected. The defects were assigned randomly to Site A (bovine-derived xenograft [Bio-Oss Collagen] with bioresorbable Type I collagen membrane [Bio-Gide]) and Site B (fibrin fibronectin sealing system [TISSEEL] with bovine-derived xenograft [Bio-Oss Collagen]). The radiographic parameters were recorded at baseline, 6 months, and 9 months postoperatively. All fourteen patients returned for recall at regular intervals till the completion of the study. Both the experimental groups showed clinically and radiographically statistically significant reduction in probing pocket depth and gain in clinical attachment level. Both groups showed potential for enhancing the periodontal regeneration with no statistically significant between the two groups; however, on comparison the Bio-Oss Collagen and TISSEEL group were slightly better.

  15. Histologic assessment of a contiguous autogenous transplant in a human intrabony defect. A case report.

    PubMed

    Zubery, Y; Kozlovsky, A; Tal, H

    1993-01-01

    Increased blood supply, vital bone marrow cells, and minimal mobility may play a significant role in the success of osseous grafts, and are characteristics of the bone swaging grafting technique. As in all autogenous grafts, the risk of disease transmission is minimal. Previous reports of clinical success raise questions as to the type of tissue response to this procedure. This case report examines 8 months radiographic and histologic results of a clinically successful bone swaging graft.

  16. Treatment of intrabony pockets with Emdogain: results at 36 months.

    PubMed

    Parodi, Renato; Santarelli, Giorgio A E; Gasparetto, Bruno

    2004-02-01

    This study reports the results obtained 36 months after treating deep periodontal defects with amelogenins. Results at 12 months have already been published. Sixteen of 21 patients completed the 3-year recall program. This study confirms after 3 years the results obtained at 1 year: Probing pocket depth decreased from 7.87 +/- 2.03 mm to 2.93 +/- 2.19 mm; recession increased from 2.20 +/- 1.42 mm to 2.93 +/- 1.87 mm; and attachment level decreased from 10.07 +/- 2.28 to 5.87 +/- 2.59 mm. No statistically significant difference was found between the data collected at 12 and 36 months. The standardized radiographs, digitized and analyzed with purpose-developed software, did not show any appreciable increase in bone volume, but only improved mineralization of the preexisting bone after 3 years using Emdogain without grafts.

  17. A comparative study of combined treatment with a collagen membrane and enamel matrix proteins for the regeneration of intraosseous defects.

    PubMed

    Minabe, Masato; Kodama, Toshiro; Kogou, Tatsuji; Takeuchi, Kayo; Fushimi, Hajime; Sugiyama, Takashi; Mitarai, Eiko

    2002-12-01

    Recent clinical study shows that periodontal regeneration therapy using enamel matrix proteins (Emdogain; EMD) is expected to have the same therapeutic effect as guided tissue regeneration (GTR). However, reports on the combined effect of both therapies are limited, and the clinical significance is not definite. In this study, clinical effects were studied by comparing a combination of EMD and GTR using a collagen membrane for intrabony defects with GTR monotherapy and EMD monotherapy. Sixty-one patients with 69 intrabony defects were included. Efficacy of treatment was evaluated at 6 months and 1 year by assessment of reduction of probing depth, probing attachment gain, and radiographic bone gain. There were no statistically significant differences between presurgical soft tissue measurements and defect characteristics for the three treatment groups. The results showed no significant differences in reduction of probing depth, probing attachment gain, or radiographic bone gain between the three treatment groups at both evaluation times. The combination of GTR using a resorbable membrane for intrabony defects and EMD did not enhance the therapeutic effect compared with each monotherapy.

  18. Effect of in-situ application of simvastatin gel in surgical management of osseous defects in chronic periodontitis-A randomized clinical trial.

    PubMed

    Ranjan, Rajeev; Patil, Sudhir R; H R, Veena

    2017-01-01

    The present randomized controlled clinical study was designed to investigate the effect of in situ application of 1.2 mg Simvastatin (SV) gel in the surgical management of Intrabony defects in chronic periodontitis patients. 20 patients contributing 40 sites were categorized into two treatment groups: Open flap debridement plus 1.2 mg SV gel (Group 1) and Open flap debridement plus Placebo gel (Group 2). Gingival index (GI), Plaque index (PI), Pocket depth (PD) and clinical attachment level (CAL) were recorded at baseline, 3 months, 6 months and 9 months. At baseline and at the end of 6 and 9 months Radiographic evaluation of Intrabony defect fill was done using Image j software. Significant reduction of GI, PD and gain in CAL was observed at the end of 9 months in both groups. Amount of bone fill and percentage of original defect fill in Group 1 was statistically highly significant than Group 2 at the end of 6 and 9 months. Higher amount of decrease in GI and PD along with more amount of CAL gain was observed in treatment group than control group. Radiological assessment confirmed that significant intrabony defect fill and percentage fill of original defect in treatment group than controlled group.

  19. Long-term effect on tooth vitality of regenerative therapy in deep periodontal bony defects: a retrospective study.

    PubMed

    de Sanctis, Massimo; Goracci, Cecilia; Zucchelli, Giovanni

    2013-01-01

    Over the last few decades, many authors have investigated the effect of periodontal disease and treatment on pulpal status with controversial results. This study was conducted to verify whether periodontal disease in a deep intrabony defect and complex therapy, including aggressive root planing such as in periodontal regeneration, have an influence on tooth vitality. One hundred thirty-seven patients who fulfilled the requirements were included. The collected data did not support the need for "preventive" root canal treatment in severely compromised teeth that are planned to undergo periodontal regenerative surgery.

  20. Birth Defects

    MedlinePlus

    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 ...

  1. Clinical Outcomes after Treatment of Periodontal Intrabony Defects with Nanocrystalline Hydroxyapatite (Ostim) or Enamel Matrix Derivatives (Emdogain): A Randomized Controlled Clinical Trial

    PubMed Central

    Hoffmann, Thomas; Lorenz, Katrin

    2014-01-01

    Introduction. Periodontitis is an inflammatory process in response to dental biofilm and leads to periodontal tissue destruction. The aim of this study was the comparison of outcomes using either an enamel matrix derivative (EMD) or a nanocrystalline hydroxyapatite (NHA) in regenerative periodontal therapy after 6 and 12 months. Methods. Using a parallel group, prospective randomized study design, we enrolled 19 patients in each group. The primary outcome was bone fill after 12 months. Attachment gain, probing pocket depth (PPD) reduction, and recession were secondary variables. Additionally, early wound healing and adverse events were assessed. Data analysis included test of noninferiority of NHA group (test) compared to EMD group (reference) in bone fill. Differences in means of secondary variables were compared by paired t-test, frequency data by exact χ 2 test. Results. Both groups showed significant bone fill, reduction of PPD, increase in recession, and gain of attachment after 6 and 12 months. No significant differences between groups were found at any time point. Adverse events were comparable between both groups with a tendency of more complaints in the NHA group. Conclusion. The clinical outcomes were similar in both groups. EMD could have some advantage compared to NHA regarding patients comfort and adverse events. The trial is registered with ClinicalTrials.gov NCT00757159. PMID:24689056

  2. Neural Tube Defects

    MedlinePlus

    ... Birth defects & other health conditions > Neural tube defects Neural tube defects E-mail to a friend Please ... this page It's been added to your dashboard . Neural tube defects (NTDs) are birth defects of the ...

  3. Congenital Defects.

    ERIC Educational Resources Information Center

    Goldman, Allen S.; And Others

    There are two general categories (not necessarily mutually exclusive) of congenital defects: (1) abnormalities that have an hereditary basis, such as single and multiple genes, or chromosomal abberration; and (2) abnormalities that are caused by nonhereditary factors, such as malnutrition, maternal disease, radiation, infections, drugs, or…

  4. Congenital Defects.

    ERIC Educational Resources Information Center

    Goldman, Allen S.; And Others

    There are two general categories (not necessarily mutually exclusive) of congenital defects: (1) abnormalities that have an hereditary basis, such as single and multiple genes, or chromosomal abberration; and (2) abnormalities that are caused by nonhereditary factors, such as malnutrition, maternal disease, radiation, infections, drugs, or…

  5. Clinical and radiographic evaluation of Emdogain as a regenerative material in the treatment of interproximal vertical defects in chronic and aggressive periodontitis patients.

    PubMed

    Vandana, K L; Shah, Kinnari; Prakash, Shobha

    2004-04-01

    This study evaluated the efficacy of Emdogain enamel matrix proteins as a regenerative material in interproximal vertical defects both clinically and radiographically. Patients aged 18 to 45 years and diagnosed with chronic or aggressive periodontitis were included. Sixteen intrabony defects in eight patients were surgically treated using a split-mouth design. Emdogain placement was done at experimental sites. Since both chronic and aggressive periodontitis patients were included, an attempt was made to interpret results between the two types of cases. Postsurgical measurements at 9 months revealed no significant difference in mean pocket depth reduction, clinical attachment level gain, amount of defect fill, or defect resolution between control and experimental groups. Mean pocket depth reduction and amount of defect fill were significant in both groups. The results were interpreted separately for chronic and aggressive periodontitis cases. This study demonstrated no added advantage of using Emdogain compared to surgical debridement alone. Further long-term and large-sample-size evaluation is required to prove Emdogain's consistent efficacy.

  6. [Effect of combined therapeutic methods on healing of periodontal vertical bone defects in regenerative surgery].

    PubMed

    Dori, Ferenc

    2009-03-15

    Several methods are available to enhance the healing and regeneration of periodontal tissues after surgical therapy of intrabony defects. The main indications for the use of combined regenerative procedures are the extent and morphology of the osseous lesions. The six studies of the present dissertation focused on the clinical effect of different barrier techniques, bone substitutes, enamel matrix derivatives and a growth factors containing adjuvant used in various combinations on the healing of severe periodontal intrabony impairments. Synthetic, xenogenetic and autologous materials were used in these randomized clinical studies. Mechanical barriers (polytetrafluoroethylene and collagen membranes) for GTR, biological barriers/enamel matrix proteins (EMD), synthetic (beta-TCP) and xenogeneic (NBM) bone grafts and autologous platelet-rich plasma (PRP) were combined in the test and control groups of the trials. The main clinical variable was the clinical attachment level (CAL) and the subsidiary one was the probing pocket depth (PPD), estimated at baseline and after one year. The summation of the results after the statistical analysis takes cognizance of the followings: a) Each of the eleven regenerative methods evaluated (ten combined procedures) leads to significant CAL gain and PPD decrease. b) Using beta-TCP or NBM with EMD or with PRP+GTR and GTR's, the difference between the parameters of the test and control groups were not statistically significant. c) It was confirmed in four studies that the addition of PRP to graft materials has not increased significantly the positive outcomes independent of the type of barrier or graft. d) Adding platelet-rich plasma to natural bone mineral, no benefit was observed from the point of view of the clinical variables. e) The polypeptide proteins of the platelet-rich plasma do not enhance the clinical regenerative effect of enamel matrix proteins. In conclusion, the option of the periodontal surgeons between these methods

  7. Genetic sperm defects.

    PubMed

    Chenoweth, Peter J

    2005-08-01

    Genetic sperm defects are specific sperm defects, which have been shown to have a genetic mode of transmission. Such genetic linkage, either direct or indirect, has been associated with a number of sperm defects in different species, with this number increasing with improved diagnostic capabilities. A number of sperm defects, which have proven or suspected genetic modes of transmission are discussed herein, with particular emphasis on cattle. These include: 1. Acrosome defects (knobbed, ruffled and incomplete); 2. Head defects (abnormal condensation, decapitated, round head, rolled head, nuclear crest); 3. Midpiece abnormalities ("Dag" defect, "corkscrew" defect, "pseudo-droplet" defect); 4. Tail defects ("tail stump" defect, primary ciliary dyskinesia).

  8. Rosuvastatin 1.2 mg In Situ Gel Combined With 1:1 Mixture of Autologous Platelet-Rich Fibrin and Porous Hydroxyapatite Bone Graft in Surgical Treatment of Mandibular Class II Furcation Defects: A Randomized Clinical Control Trial.

    PubMed

    Pradeep, A R; Karvekar, Shruti; Nagpal, Kanika; Patnaik, Kaushik; Raju, Arjun; Singh, Priyanka

    2016-01-01

    A wide range of regenerative materials have been tried and tested in the treatment of furcation defects. Rosuvastatin (RSV) is a new synthetic, second-generation, sulfur-containing, hydrophilic statin with potent anti-inflammatory and osseodifferentiation mechanisms of action. Platelet-rich fibrin (PRF) is a platelet concentrate having sustained release of various growth factors with regenerative potential to treat periodontal defects. Porous hydroxyapatite (HA) bone grafting material has a clinically satisfactory response when used to fill periodontal intrabony defects. This double-masked randomized study is designed to evaluate the potency of a combination of 1.2 mg RSV in situ gel with a 1:1 mixture of autologous PRF and HA bone graft in the surgical treatment of mandibular Class II furcation defects compared with autologous PRF and HA bone graft placed after open-flap debridement (OFD). One hundred five mandibular furcation defects were treated with OFD + placebo gel (group 1), PRF + HA with OFD (group 2), or 1.2 mg RSV gel + PRF + HA with OFD (group 3). Clinical and radiologic parameters (i.e., probing depth [PD], relative vertical and relative horizontal clinical attachment level [rvCAL and rhCAL], intrabony defect depth, and percentage of defect fill) were recorded at baseline and 9 months postoperatively. Mean PD reduction was greater in group 2 (3.68 ± 1.07 mm) and group 3 (4.62 ± 1.03 mm) than group 1 (2.11 ± 1.25 mm), and mean rvCAL and rhCAL gain were greater in group 2 (3.31 ± 0.52 and 2.97 ± 0.56 mm, respectively) and group 3 (4.17 ± 0.70 and 4.05 ± 0.76 mm) compared with group 1 (1.82 ± 0.78 and 1.62 ± 0.64 mm). A significantly greater percentage of mean bone fill was found in group 2 (54.69% ± 1.93%) and group 3 (61.94% ± 3.54%) compared with group 1 (10.09% ± 4.28%). Treatment of furcation defects with 1.2 mg RSV in situ gel combined with autologous PRF and porous HA bone graft results in significant improvements of clinical and

  9. Mandibular Degree II Furcation Defects Treatment With Platelet-Rich Fibrin and 1% Alendronate Gel Combination: A Randomized Controlled Clinical Trial.

    PubMed

    Kanoriya, Dharmendra; Pradeep, A R; Garg, Vibhuti; Singhal, Sandeep

    2017-03-01

    Different materials have been investigated for renewal of lost supporting periodontal structures and tested for furcation defect treatment. Platelet-rich fibrin (PRF) is a pool of growth-promoting factors and cytokines that promote bone regeneration and maturation of soft tissue. Alendronate (ALN), an influential member of the bisphosphonate group, is known to enhance osteoblastogenesis and inhibit osteoclastic bone resorption, thus promoting tissue regeneration. This randomized trial was done to assess effectiveness of PRF and 1% ALN gel combination in mandibular degree II furcation defect treatment in comparison with PRF and access therapy alone. Seventy-two mandibular molar furcation defects were treated with either access therapy alone (group 1), access therapy with PRF (group 2), or access therapy with PRF and 1% ALN (group 3). Plaque index, modified sulcus bleeding index, probing depth (PD), relative vertical attachment level (RVAL) and relative horizontal attachment level (RHAL), and intrabony defect depth were recorded at baseline and 9 months postoperatively. Radiographically, defect fill, assessed in percentage, was evaluated at baseline, before surgery, and 9 months post-therapy. Group 3 showed greater PD reduction and RVAL and RHAL gain when compared with groups 1 and 2 postoperatively. Moreover, group 3 sites showed a significantly greater percentage of radiographic defect fill (56.01% ± 2.64%) when compared with group 2 (49.43% ± 3.70%) and group 1 (10.25% ± 3.66%) at 9 months. Furcation defect treatment with autologous PRF combined with 1% ALN gel results in significant therapeutic outcomes when compared with PRF and access therapy alone. Combining ALN with PRF has potential for regeneration of furcation defects without any adverse effect on healing process.

  10. Immunohistochemical characteristics of regenerated bone after surgical therapy of advanced ligature-induced peri-implantitis defects.

    PubMed

    Schwarz, Frank; Mihatovic, Ilja; Golubovic, Vladimir; Becker, Jürgen; Sager, Martin

    2014-07-01

    This study seeks to assess and compare immunohistochemical characteristics of regenerated and pristine bone areas following surgical therapy of advanced peri-implantitis. At ligature-induced peri-implantitis defects, the intrabony component was filled with a natural bone mineral (NBM), and the supracrestal component was treated by either an equine bone block (EB) or implantoplasty. NBM and EB were soak-loaded with rhBMP-2 or sterile saline. Membrane (i.e., native collagen) protected sites were submerged for 12 weeks. Osteocalcin (OC) and transglutaminase 2 (TG2; angiogenesis) antigen reactivity was assessed within the augmented-(AA) and pristine bone (PB) areas at non-exposed sites (n = 39 defects). In all groups investigated, mean OC (AA, 0.5 ± 0.4 to 1.9 ± 2.9 %/PB, 1.7 ± 2.6 to 3.5 ± 6.5 %) and TG2 (AA, 0.6 ± 0.5 to 1.3 ± 1.5 %/PB, 0.5 ± 0.5 to 1.6 ± 1.9 %) values within AA did not significantly differ from those values assessed within PB (P > 0.05, respectively). AA formed in different treatment groups may not be considered as qualitatively (i.e., OC and TG2) compromised bone.

  11. Neural Tube Defects

    MedlinePlus

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

  12. Facts about Birth Defects

    MedlinePlus

    ... Button Information For… Media Policy Makers Facts about Birth Defects Language: English (US) Español (Spanish) Recommend ... having a baby born without a birth defect. Birth Defects Are Common Every 4 ½ minutes, a ...

  13. Birth Defects (For Parents)

    MedlinePlus

    ... there is a problem with a baby's body chemistry, it is called a metabolic birth defect. Metabolic defects prevent the body from properly breaking down food to create energy. Examples of metabolic defects include ...

  14. Atrial septal defect (ASD)

    MedlinePlus

    ... other heart defects of the ventricular septum and mitral valve . Secundum defects can be a single, small ... Sometimes, open-heart surgery may be needed to repair the defect. The type of surgery is more ...

  15. Atrioventricular Canal Defect

    MedlinePlus

    ... birth (congenital). The condition is often associated with Down syndrome. Atrioventricular canal defect allows extra blood to flow ... baby's heart is developing. Some factors, such as Down syndrome, might increase the risk of atrioventricular canal defect. ...

  16. Birth Defects (For Parents)

    MedlinePlus

    ... to create energy. Examples of metabolic defects include Tay-Sachs disease , a fatal disease that affects the central nervous ... called recessive inheritance and includes conditions such as Tay-Sachs disease and cystic fibrosis . A disease or defect also ...

  17. Duralumin - Defects and Failures

    NASA Technical Reports Server (NTRS)

    Nelson, WM

    1927-01-01

    It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.

  18. Congenital defects of sheep.

    PubMed

    Dennis, S M

    1993-03-01

    With increasing incrimination of viruses, plants, and drugs as causes of ovine congenital defects, concerted efforts are required to identify environmental teratogens. Expanding knowledge of congenital defects requires studying as many defective lambs as possible; recording and documenting; detailed diagnostic examinations; genetic analyses and chromosomal examinations, whenever possible; and field investigations. Adopting standardized classification, terminology, and diagnostic procedures should improve descriptions, diagnoses, and interdisciplinary exchange of information. That, in turn, should improve our knowledge of and diagnosis of congenital defects of sheep in the future. Finally, veterinary clinicians and diagnosticians are encouraged to take an interest in congenital defects and teratology.

  19. Defect production in ceramics

    SciTech Connect

    Zinkle, S.J.; Kinoshita, C.

    1997-08-01

    A review is given of several important defect production and accumulation parameters for irradiated ceramics. Materials covered in this review include alumina, magnesia, spinel silicon carbide, silicon nitride, aluminum nitride and diamond. Whereas threshold displacement energies for many ceramics are known within a reasonable level of uncertainty (with notable exceptions being AIN and Si{sub 3}N{sub 4}), relatively little information exists on the equally important parameters of surviving defect fraction (defect production efficiency) and point defect migration energies for most ceramics. Very little fundamental displacement damage information is available for nitride ceramics. The role of subthreshold irradiation on defect migration and microstructural evolution is also briefly discussed.

  20. Topological defect lasers

    NASA Astrophysics Data System (ADS)

    Knitter, Sebastian; Fatt Liew, Seng; Xiong, Wen; Guy, Mikhael I.; Solomon, Glenn S.; Cao, Hui

    2016-01-01

    We introduce a topological defect to a regular photonic crystal defect cavity with anisotropic unit cell. Spatially localized resonances are formed and have high quality factor. Unlike the regular photonic crystal defect states, the localized resonances in the topological defect structures support powerflow vortices. Experimentally we realize lasing in the topological defect cavities with optical pumping. This work shows that the spatially inhomogeneous variation of the unit cell orientation adds another degree of freedom to the control of lasing modes, enabling the manipulation of the field pattern and energy flow landscape.

  1. Postdevelopment defect evaluation

    NASA Astrophysics Data System (ADS)

    Miyahara, Osamu; Kiba, Yukio; Ono, Yuko

    2001-08-01

    Reduction of defects after development is a critical issue in photolithography. A special category of post development defects is the satellite defect which is located in large exposed areas generally in proximity to large unexposed regions of photoresist. We have investigated the formation of this defect type on ESCAP and ACETAL DUV resists with and without underlying organic BARCs, In this paper, we will present AFM and elemental analysis data to determine the origin of the satellite defect. Imaging was done on a full-field Nikon 248nm stepper and resist processing was completed on a TEL CLEAN TRACK ACT 8 track. Defect inspection and review were performed on a KLA-Tencor and Hitachi SEM respectively. Results indicate that the satellite defect is generated on both BARC and resist films and defect counts are dependent on the dark erosion. Elemental analysis indicates that the defects are composed of sulfur and nitrogen compounds. We suspect that the defect is formed as a result of a reaction between PAG, quencher and TMAH. This defect type is removed after a DIW re-rinse.

  2. Ventricular Septal Defect (For Parents)

    MedlinePlus

    ... Atrial Septal Defect Ventricular Septal Defect Heart and Circulatory System ECG (Electrocardiogram) Anesthesia - What to Expect Tetralogy of ... Atrial Septal Defect Ventricular Septal Defect Heart and Circulatory System Contact Us Print Resources Send to a friend ...

  3. Ventricular Septal Defect (For Parents)

    MedlinePlus

    ... Atrial Septal Defect Ventricular Septal Defect Heart and Circulatory System ECG (Electrocardiogram) Anesthesia - What to Expect Tetralogy of ... Atrial Septal Defect Ventricular Septal Defect Heart and Circulatory System Contact Us Print Resources Send to a Friend ...

  4. A Clinical and Radiographic Evaluation of Periodontal Regenerative Potential of PerioGlas®: A Synthetic, Resorbable Material in Treating Periodontal Infrabony Defects.

    PubMed

    Chacko, Neelathil Lisa; Abraham, Sathish; Rao, H N Shama; Sridhar, N; Moon, Ninad; Barde, Dhananjay H

    2014-06-01

    Study of the clinical application of bioactive glass in treating periodontal defects has been gaining momentum. Studies in the past have hypothesized that bioactive glass resulted in an improvement of bony lesion when compared with open flap debridement. Considering that there were very few studies in the Indian dental literature involving the analysis of PerioGlas®- A particulate Bioglass in intrabony defects, the present clinical trial aimed to clinically and radiographically evaluate the efficacy of PerioGlas® and compare it to open debridement as control in the treatment of human periodontal osseous (three and two wall) defects in South Indian population. Ten patients with chronic periodontitis within the age group of 30-45 years having at least two pockets with depth of ≥6 mm exhibiting vertical osseous defects were selected for the study. A total of 20 defect sites were randomly assigned to one of the two treatment modalities such that 10 sites (experimental) received PerioGlas® material after open flap debridement and 10 sites with open flap debridement (controls). Plaque index and gingival index (GI) were recorded at baseline, 6 weeks, 3 months, 6 months and 9 months, whereas probing pocket depth (PPD), clinical attachment level and gingival recession (GR) were recorded at baseline, 6 and 9 months postoperatively. Linear radiographic measurements were carried out at baseline, 6 and 9 months to evaluate the defect fill, defect resolution and change in the alveolar crest height (ACH). Both experimental and control site showed a significant reduction in plaque and GI, and a slight increase in GR. The mean reduction in PPD for experimental and control site was 4.4 ± 0.34 mm and 3.2 ± 0.1 mm, respectively. Gain in clinical attachment at experimental and control site was 4.4 ± 0.21 and 3.4 ± 0.11, respectively which on comparison was statistically non-significant for both sites. The radiographic mean defect fill for experimental site was 1.73 mm. The

  5. Repair of Auricular Defects.

    PubMed

    Watson, Deborah; Hecht, Avram

    2017-08-01

    Repairing defects of the auricle requires an appreciation of the underlying 3-dimensional framework, the flexible properties of the cartilages, and the healing contractile tendencies of the surrounding soft tissue. In the analysis of auricular defects and planning of their reconstruction, it is helpful to divide the auricle into subunits for which different techniques may offer better functional and aesthetic outcomes. This article reviews many of the reconstructive options for defects of the various auricular subunits. Published by Elsevier Inc.

  6. Defects in hardwood timber

    Treesearch

    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...

  7. Isolation and Assessment of Mesenchymal Stem Cells Derived From Bone Marrow: Histologic and Histomorphometric Study in a Canine Periodontal Defect.

    PubMed

    Paknejad, Mojgan; Eslaminejad, Mohamadreza Baghaban; Ghaedi, Baharak; Rokn, Amir-Reza; Khorsand, Afshin; Etemad-Moghadam, Shahroo; Alaeddini, Mojgan; Dehghan, Mohammad Mehdi; Moslemi, Neda; Nowzari, Hessam

    2015-06-01

    The aim of the present study was to investigate an isolation procedure to culture mesenchymal stem cells derived from bone marrow and evaluate their potential in periodontal regeneration. Potential stem cells from bone marrow, aspirated from the iliac crest of nine mongrel canines 1 to 2 years of age, were cultivated. After the examination of surface epitopes of the isolated cells, the total RNA from osteogenic, adipogenic, and chondrogenic cell cultures were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to confirm stem cell gene expressions. 2 × 10(7) mL of the stem cells were loaded on 0.2 mL of anorganic bovine bone mineral (ABBM) granules. In each animal, bilateral acute/chronic intrabony periodontal defects were created surgically and by placement of ligatures around the cervical aspect of the teeth. At week 5, after flap debridement, the bilateral defects were randomly assigned to 2 treatment groups: the control group received ABBM, and the test group received BMSCs-loaded ABBM. Eight weeks after transplantation, regenerative parameters were analyzed histologically and histometrically. The RNA expressions confirmed the cultivation of mesenchymal stem cell. More new cementum and periodontal ligament (PDL) were measured in the test group (cementum: 3.33 ± 0.94 vs 2.03 ± 1.30, P = 0.027; PDL: 2.69 ± 0.73 vs 1.53 ± 1.21, P = 0.026). New bone formation was similar in both groups (2.70 ± 0.86 vs 1.99 ± 1.31; P = 0.193). Mesenchymal stem cells derived from bone marrow should be considered a promising technique for use in patients with periodontal attachment loss and merits further investigations.

  8. Diabetes mellitus and birth defects

    PubMed Central

    Correa, Adolfo; Gilboa, Suzanne M.; Besser, Lilah M.; Botto, Lorenzo D.; Moore, Cynthia A.; Hobbs, Charlotte A.; Cleves, Mario A.; Riehle-Colarusso, Tiffany J.; Waller, D. Kim; Reece, E. Albert

    2016-01-01

    OBJECTIVE The purpose of this study was to examine associations between diabetes mellitus and 39 birth defects. STUDY DESIGN This was a multicenter case-control study of mothers of infants who were born with (n = 13,030) and without (n = 4895) birth defects in the National Birth Defects Prevention Study (1997–2003). RESULTS Pregestational diabetes mellitus (PGDM) was associated significantly with noncardiac defects (isolated, 7/23 defects; multiples, 13/23 defects) and cardiac defects (isolated, 11/16 defects; multiples, 8/16 defects). Adjusted odds ratios for PGDM and all isolated and multiple defects were 3.17 (95% CI, 2.20–4.99) and 8.62 (95% CI, 5.27–14.10), respectively. Gestational diabetes mellitus (GDM) was associated with fewer noncardiac defects (isolated, 3/23 defects; multiples, 3/23 defects) and cardiac defects (isolated, 3/16 defects; multiples, 2/16 defects). Odds ratios between GDM and all isolated and multiple defects were 1.42 (95% CI, 1.17–1.73) and 1.50 (95% CI, 1.13–2.00), respectively. These associations were limited generally to offspring of women with prepregnancy body mass index ≥25 kg/m2. CONCLUSION PGDM was associated with a wide range of birth defects; GDM was associated with a limited group of birth defects. PMID:18674752

  9. Defects in Calcite.

    DTIC Science & Technology

    1991-05-13

    AD-A245 645 A TRIDENT SCHOLAR PROJECT REPORT NO. 181 "DEFECTS IN CALCITE " DTTC %N FEB 5-1912 UNITED STATES NAVAL ACADEMY ANNAPOLIS, MARYLAND 92-02841...report; no. 181 (1991) "DEFECTS IN CALCITE " A Trident Scholar Project Report by Midshipman Anthony J. Kotarski, Class of 1991 U. S. Naval Academy Annapolis...REPORT TYPE AND DATES COVERED 13 May 1991 Final 1990/91 . TITLE AND SUBTITLE s. FUNDING NUMBERS DEFECTS IN CALCITE 6. AUTHOR(S) Anthony J. Kotarski 7

  10. Improvement of an anterior infrabone defect using combined periodontal and orthodontic therapy: A 6-year follow-up case report

    PubMed Central

    de Molon, Rafael Scaf; Kim, Yeon Jung; dos Santos-Pinto, Ary; Cirelli, Joni Augusto

    2014-01-01

    Extensive intraosseous lesions represent a clinical challenge for the periodontist. Sites with bone defects have been shown to be at higher risk of periodontitis progression in patients who had not received periodontal therapy. Thus, the aim of this case report was to describe a novel approach for the treatment of 1-walled intraosseous defect by combining nonsurgical periodontal therapy and orthodontic movement toward the bone defect, avoiding regenerative and surgical procedures. A 47-year-old woman underwent the proposed procedures for the treatment of her left central incisor with 9 mm probing depth and 1-walled intraosseous defect in its mesial aspect. Initially, basic periodontal therapy with scaling and root planning was accomplished. Two months later, an orthodontic treatment was planned to eliminate the intraosseous lesion and to improve the interproximal papillary area. Orthodontic root movement toward the osseous defect was performed for 13 months with light forces. After 6 years postoperative it was concluded that combined basic periodontal therapy and orthodontic movement was capable of eliminating the intraosseous defect and improve the esthetics in the interproximal papillary area between the central incisors. PMID:25202224

  11. A comparative evaluation of the effectiveness of guided tissue regeneration by using a collagen membrane with or without decalcified freeze-dried bone allograft in the treatment of infrabony defects: A clinical and radiographic study

    PubMed Central

    Kher, Vishal Kiran; Bhongade, Manohar L.; Shori, Tony D.; Kolte, Abhay P.; Dharamthok, Swarup B.; Shrirao, Tushar S.

    2013-01-01

    Background: The present, randomized, controlled clinical and radiographic study was undertaken to compare the effectiveness of guided tissue regeneration (GTR) by using a collagen membrane barrier with or without decalcified freeze-dried bone allograft (DFDBA) in the treatment of periodontal infrabony defects characterized by unfavorable architecture. Materials and Methods: Sixteen systemically healthy patients with 20 periodontal infrabony defects were selected for the study. Each patient had at least ≥ 5 mm clinical probing pocket depth (PPD) at the selected site and depth of intrabony component ≥ 3 mm as assessed by clinical and radiographic measurements. Baseline measurements included plaque index, papillary bleeding index, PPD, gingival recession, clinical attachment level and radiographic defect depth (DD). At the time of surgery, the defects were randomly assigned to either the test group (collagen membrane plus DFDBA) or the control group (collagen membrane only). Results: At the 6-month examination, PPPD reduction was significantly greater in the GTR + DFDBA group (4.06 ± 0.38 mm) compared with the GTR group (3.2 ± 0.74 mm). The mean gains of clinical attachment were 3.54 ± 0.36 mm in the test group and 2.50 ± 0.74 mm in the control group. Radiographic DD reduction was similarly greater in the GTR + DFDBA group (2.40 ± 0.51 mm) compared with the GTR group (1.60 ± 0.51 mm). Conclusions: The results of the present study indicate that the use of a GTR membrane with bone graft has significantly improved all clinical parameters tested as compared with the use of bioresorbable membrane alone in the treatment of infrabony defects characterized by unfavorable architecture. PMID:24174729

  12. Birth Defects: Cerebral Palsy

    MedlinePlus

    ... unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our ... experts Calculating your due date Ovulation calendar Order bereavement materials News Moms Need Blog News & Media News ...

  13. Ventricular Septal Defect (VSD)

    MedlinePlus

    ... specially sized mesh device to close the hole. Hybrid procedure. A hybrid procedure uses surgical and catheter-based techniques. Access ... clinicalkey.com. Accessed Sept. 15, 2014. Konetti NR. Hybrid muscular ventricular defect closure: Surgeon or physician. Indian ...

  14. Ventricular Septal Defect (VSD)

    MedlinePlus

    ... you exert yourself or when you lie down Rapid or irregular heartbeat Fatigue or weakness Causes Congenital heart defects arise from problems early in the heart's development, but there's often no clear cause. Genetics and ...

  15. Single Ventricle Defects

    MedlinePlus

    ... artery and blood reaches the aorta through a patent ductus arteriosus (see diagram). How does the defect ... only source of lung blood flow is the patent ductus arteriosus (PDA), an open passageway between the ...

  16. Detecting Speech Defects

    ERIC Educational Resources Information Center

    Kryza, Frank T., II

    1976-01-01

    Discusses the importance of early detection of speech defects and briefly describes the activities of the Pre-School Diagnostic Center for Severe Communication Disorders in New Haven, Connecticut. (ED)

  17. Neural Tube Defects

    MedlinePlus

    ... unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our ... experts Calculating your due date Ovulation calendar Order bereavement materials News Moms Need Blog News & Media News ...

  18. Birth Defects: Cerebral Palsy

    MedlinePlus

    ... unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our ... experts Calculating your due date Ovulation calendar Order bereavement materials News Moms Need Blog News & Media News ...

  19. Congenital Heart Defects

    MedlinePlus

    ... Treatment can include medicines, catheter procedures, surgery, and heart transplants. The treatment depends on the type of the defect, how severe it is, and a child's age, size, and general health. NIH: National Heart, Lung, and Blood Institute

  20. Birth defects monitoring

    SciTech Connect

    Klingberg, M.A.; Papier, C.M.; Hart, J.

    1983-01-01

    Population monitoring of birth defects provides a means for detecting relative changes in their frequency. Many varied systems have been developed throughout the world since the thalidomide tragedy of the early 1960s. Although it is difficult to pinpoint specific teratogenic agents based on rises in rates of a particular defect or a constellation of defects, monitoring systems can provide clues for hypothesis testing in epidemiological investigations. International coordination of efforts in this area resulted in the founding of the International Clearinghouse for Birth Defects Monitoring Systems (ICBDMS) in 1974. In this paper we will describe the functions and basic requirements of monitoring systems in general, and look at the development and activities of the ICBDMS. A review of known and suspected environmental teratogenic agents (eg, chemical, habitual, biological, physical, and nutritional) is also presented.

  1. The effects of enamel matrix derivative and cyclic mechanical strain on human gingival fibroblasts in an in vitro defect healing model.

    PubMed

    Sanders, Jill E; Chuang, Augustine; Swiec, Gary D; Bisch, Fredrick C; Herold, Robert W; Buxton, Thomas B; McPherson, James C

    2011-01-01

    Gingival fibroblasts (GFs) play a considerable role in the maintenance of the gingival apparatus as well as in connective tissue repair. Mobility of a periodontal wound or soft tissue graft can impair connective tissue healing from the GFs. Enamel matrix derivative (EMD) is an enamel matrix protein used clinically for periodontal regeneration of intrabony defects and furcations, as well as treatment of gingival margin recessions. The goal of this project was to compare the effects of varying concentrations of EMD, with and without cyclic mechanical strain, on cellular wound fill of human GFs using an in vitro defect healing model. GFs were seeded and cultured in six-well flexible-bottomed plates. A 3-mm wound was created in the central portion of each confluent well. Three wells were treated with each EMD concentration of 0 Μg/mL (control), 30 Μg/mL, 60 Μg/mL, or 120 Μg/mL. The plates were placed in an incubator containing a strain unit to subject test plates to cyclic strain. An identical set of control plates were not flexed. Cells were examined on days 4, 8, 12, and 16. Microphotographs were taken and wound fill measurements made using image analysis software. The percent wound fill was calculated. All nonflexed plates, regardless of EMD concentration, reached > 90% defect fill at similar rates by day 16. However, in the flexed plates, EMD had a significant negative effect on defect fill. The defect fill was 55.7% for 0 Μg/mL EMD, 48.2% for 30 Μg/mL EMD, 36.7% for 60 Μg/mL EMD, and 34.1% for 120 Μg/mL EMD on day 16 for the flexed GFs. EMD, in concentrations as high as 120 Μg/mL, did not significantly affect the amount of defect fill with nonflexed GFs. However, when the GFs were flexed, the addition of EMD had a significant negative effect on defect fill in a dose-dependent manner.

  2. Birth Defects. Matrix No. 2.

    ERIC Educational Resources Information Center

    Brent, Robert L.

    This report discusses the magnitude of the problem of birth defects, outlines advances in the birth defects field in the past decade, and identifies those areas where research is needed for the prevention, treatment, and management of birth defects. The problem of birth defects has consumed a greater portion of our health care resources because of…

  3. Structural birth defects associated with neural tube defects in Hawai'i from 1986 until 2001.

    PubMed

    Forrester, Mathias B; Merz, Ruth D

    2007-09-01

    Using birth defects registry data, this study identified birth defects associated with anencephaly, spina bifida, and encephalocele. Musculoskeletal defects were associated with anencephaly; central nervous system defects, gastrointestinal atresia/stenosis, genitourinary system defects, and musculoskeletal system defects with spina bifida; and central nervous system defects, respiratory defects, oral clefts, genitourinary system defects, and musculoskeletal system defects with encephalocele.

  4. Reconstruction of Mandibular Defects

    PubMed Central

    Chim, Harvey; Salgado, Christopher J.; Mardini, Samir; Chen, Hung-Chi

    2010-01-01

    Defects requiring reconstruction in the mandible are commonly encountered and may result from resection of benign or malignant lesions, trauma, or osteoradionecrosis. Mandibular defects can be classified according to location and extent, as well as involvement of mucosa, skin, and tongue. Vascularized bone flaps, in general, provide the best functional and aesthetic outcome, with the fibula flap remaining the gold standard for mandible reconstruction. In this review, we discuss classification and approach to reconstruction of mandibular defects. We also elaborate upon four commonly used free osteocutaneous flaps, inclusive of fibula, iliac crest, scapula, and radial forearm. Finally, we discuss indications and use of osseointegrated implants as well as recent advances in mandibular reconstruction. PMID:22550439

  5. Wire insulation defect detector

    NASA Technical Reports Server (NTRS)

    Greulich, Owen R. (Inventor)

    2004-01-01

    Wiring defects are located by detecting a reflected signal that is developed when an arc occurs through the defect to a nearby ground. The time between the generation of the signal and the return of the reflected signal provides an indication of the distance of the arc (and therefore the defect) from the signal source. To ensure arcing, a signal is repeated at gradually increasing voltages while the wire being tested and a nearby ground are immersed in a conductive medium. In order to ensure that the arcing occurs at an identifiable time, the signal whose reflection is to be detected is always made to reach the highest potential yet seen by the system.

  6. Assessing EUV mask defectivity

    NASA Astrophysics Data System (ADS)

    Okoroanyanwu, Uzodinma; Tchikoulaeva, Anna; Ackmann, Paul; Wood, Obert; La Fontaine, Bruno; Bubke, Karsten; Holfeld, Christian; Peters, Jan Hendrik; Kini, Sumanth; Watson, Sterling; Lee, Isaac; Mu, Bo; Lim, Phillip; Raghunathan, Sudhar; Boye, Carol

    2010-04-01

    This paper assesses the readiness of EUV masks for pilot line production. The printability of well characterized reticle defects, with particular emphasis on those reticle defects that cause electrical errors on wafer test chips, is investigated. The reticles are equipped with test marks that are inspected in a die-to-die mode (using DUV inspection tool) and reviewed (using a SEM tool), and which also comprise electrically testable patterns. The reticles have three modules comprising features with 32 nm ground rules in 104 nm pitch, 22 nm ground rules with 80 nm pitch, and 16 nm ground rules with 56 nm pitch (on the wafer scale). In order to determine whether specific defects originate from the substrate, the multilayer film, the absorber stack, or from the patterning process, the reticles were inspected after each fabrication step. Following fabrication, the reticles were used to print wafers on a 0.25 NA full-field ASML EUV exposure tool. The printed wafers were inspected with state of the art bright-field and Deep UV inspection tools. It is observed that the printability of EUV mask defects down to a pitch of 56 nm shows a trend of increased printability as the pitch of the printed pattern gets smaller - a well established trend at larger pitches of 80 nm and 104 nm, respectively. The sensitivity of state-of-the-art reticle inspection tools is greatly improved over that of the previous generation of tools. There appears to be no apparent decline in the sensitivity of these state-of-the-art reticle inspection tools for higher density (smaller) patterns on the mask, even down to 56nm pitch (1x). Preliminary results indicate that a blank defect density of the order of 0.25 defects/cm2 can support very early learning on EUV pilot line production at the 16nm node.

  7. Scanning electron microscope automatic defect classification of process induced defects

    NASA Astrophysics Data System (ADS)

    Wolfe, Scott; McGarvey, Steve

    2017-03-01

    With the integration of high speed Scanning Electron Microscope (SEM) based Automated Defect Redetection (ADR) in both high volume semiconductor manufacturing and Research and Development (R and D), the need for reliable SEM Automated Defect Classification (ADC) has grown tremendously in the past few years. In many high volume manufacturing facilities and R and D operations, defect inspection is performed on EBeam (EB), Bright Field (BF) or Dark Field (DF) defect inspection equipment. A comma separated value (CSV) file is created by both the patterned and non-patterned defect inspection tools. The defect inspection result file contains a list of the inspection anomalies detected during the inspection tools' examination of each structure, or the examination of an entire wafers surface for non-patterned applications. This file is imported into the Defect Review Scanning Electron Microscope (DRSEM). Following the defect inspection result file import, the DRSEM automatically moves the wafer to each defect coordinate and performs ADR. During ADR the DRSEM operates in a reference mode, capturing a SEM image at the exact position of the anomalies coordinates and capturing a SEM image of a reference location in the center of the wafer. A Defect reference image is created based on the Reference image minus the Defect image. The exact coordinates of the defect is calculated based on the calculated defect position and the anomalies stage coordinate calculated when the high magnification SEM defect image is captured. The captured SEM image is processed through either DRSEM ADC binning, exporting to a Yield Analysis System (YAS), or a combination of both. Process Engineers, Yield Analysis Engineers or Failure Analysis Engineers will manually review the captured images to insure that either the YAS defect binning is accurately classifying the defects or that the DRSEM defect binning is accurately classifying the defects. This paper is an exploration of the feasibility of the

  8. Supersymmetric k-defects

    DOE PAGES

    Koehn, Michael; Trodden, Mark

    2016-03-03

    In supersymmetric theories, topological defects can have nontrivial behaviors determined purely by whether or not supersymmetry is restored in the defect core. A well-known example of this is that some supersymmetric cosmic strings are automatically superconducting, leading to important cosmological effects and constraints. We investigate the impact of nontrivial kinetic interactions, present in a number of particle physics models of interest in cosmology, on the relationship between supersymmetry and supercurrents on strings. Furthermore, we find that in some cases it is possible for superconductivity to be disrupted by the extra interactions.

  9. Supersymmetric k-defects

    NASA Astrophysics Data System (ADS)

    Koehn, Michael; Trodden, Mark

    2016-04-01

    In supersymmetric theories, topological defects can have nontrivial behaviors determined purely by whether or not supersymmetry is restored in the defect core. A well-known example of this is that some supersymmetric cosmic strings are automatically superconducting, leading to important cosmological effects and constraints. We investigate the impact of nontrivial kinetic interactions, present in a number of particle physics models of interest in cosmology, on the relationship between supersymmetry and supercurrents on strings. We find that in some cases it is possible for superconductivity to be disrupted by the extra interactions.

  10. Quantum computing with defects.

    PubMed

    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.

  11. Quantum computing with defects

    PubMed Central

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

    2010-01-01

    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. PMID:20404195

  12. Defects in flexoelectric solids

    NASA Astrophysics Data System (ADS)

    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.

  13. Pure Titanium Membrane (Ultra – Ti®) in the Treatment of Periodontal Osseous Defects: A Split-Mouth Comparative Study

    PubMed Central

    Khanna, Rajeev; Pardhe, Nilesh Dinesh; Srivastava, Nancy; Bajpai, Manas; Gupta, Shailendra

    2016-01-01

    Introduction Although many different types of Guided Tissue Regeneration (GTR) membranes (resorbable/non-resorbable, including titanium mesh) have been used in the field of Periodontics till now, but this is the first and only clinical study testing the effectiveness of an ultra thin pure Titanium Membrane (Ultra Ti) as a GTR membrane in infra-bony periodontal defects. Aim To compare the efficacy of GTR in intra-bony defects with newly introduced non-resorbable barrier membrane, made of titanium called “Ultra-Ti ® GTR Membrane” versus open flap debridement. Materials and Methods A prospective, randomized, controlled, clinical split mouth study was designed wherein each patient received both the control and test treatment. Two similar defects were selected in each of the 12 patients and were randomly assigned to one of the two treatments. Both the surgeries consisted of identical procedures except for the omission of the barrier membrane in the control sites. Full mouth Plaque Index (PI), Gingival Index (GI), Pocket Probing Depth (PPD) and Relative Attachment Level (RAL) were recorded before surgery and after 6 months and 9 months along with hard tissue measurements at the time of surgery and then at re-entry after 9 months. Radiographs were also taken before surgery and 9 months post operatively. Student’s paired t-test and unpaired t-test (SPSS software version 9) were used to analyze the results. Results Nine months after treatment, the test defects gained 4.375 ± 1.189mm of RAL, while the control defects yielded a significantly lower RAL gain of 3.417 ± 0.996mm. Pocket reduction was also significantly higher in the test group (4.917 ± 0.996mm) when compared with the controls (3.83 ± 0.718mm). There was a significant bone fill (54.69% of defect fill) obtained in the test site, unlike the control site (8.91%). Conclusion The present study demonstrated that GTR with “Ultra-Ti® GTR Membrane” resulted in a significant added benefit in comparison with

  14. Congenital heart defect - corrective surgery

    MedlinePlus

    ... repair; Tetralogy of Fallot repair; Coarctation of the aorta repair; Atrial septal defect repair; Ventricular septal defect ... the pulmonary valve and removing the thickened muscle (stenosis). Placing a patch on the right ventricle and ...

  15. Birth Defects Data and Statistics

    MedlinePlus

    ... this? Submit Button Information For… Media Policy Makers Data & Statistics Recommend on Facebook Tweet Share Compartir On ... of birth defects in the United States. For data on specific birth defects, please visit the specific ...

  16. Guidance for Preventing Birth Defects

    MedlinePlus

    ... Prevention. Commit to Healthy Choices to Help Prevent Birth Defects Language: English (US) Español (Spanish) Recommend on ... Tweet Share Compartir We know that not all birth defects can be prevented. But, we also know ...

  17. Atrial Septal Defect (For Parents)

    MedlinePlus

    ... Defect Preparing Your Child for Surgery Heart and Circulatory System Anesthesia Basics Congenital Heart Defects Activity: The Heart ... EKG (Video) Going to the Hospital Your Heart & Circulatory System Quiz: Heart & Circulatory System EKG (Video) What's It ...

  18. Neural tube defects.

    PubMed

    Greene, Nicholas D E; Copp, Andrew J

    2014-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechanisms underlying neural tube closure and NTDs may be informed by experimental models, which have revealed numerous genes whose abnormal function causes NTDs and have provided details of critical cellular and morphological events whose regulation is essential for closure. Such models also provide an opportunity to investigate potential risk factors and to develop novel preventive therapies.

  19. Controversies in Parotid Defect Reconstruction.

    PubMed

    Tamplen, Matthew; Knott, P Daniel; Fritz, Michael A; Seth, Rahul

    2016-08-01

    Reconstruction of the parotid defect is a complex topic that encompasses restoration of both facial form and function. The reconstructive surgeon must consider facial contour, avoidance of Frey syndrome, skin coverage, tumor surveillance, potential adjuvant therapy, and facial reanimation when addressing parotid defects. With each defect there are several options within the reconstructive ladder, creating controversies regarding optimal management. This article describes surgical approaches to reconstruction of parotid defects, highlighting areas of controversy.

  20. Molecular defects in the chondrodysplasias

    SciTech Connect

    Rimoin, D.L.

    1996-05-03

    There has been a recent explosion of knowledge concerning the biochemical and molecular defects in the skeletal dysplasia. Through both the candidate gene approach and positional cloning, specific gene defects that produce the skeletal dysplasia have been identified and may be classified into several general categories: (1) qualitative or quantitative abnormalities in the structural proteins of cartilage; (2) inborn errors of cartilage metabolism; (3) defects in local regulators of cartilage growth; and (4) systemic defects influencing cartilage development. 35 refs., 1 tab.

  1. Composite Defect Significance.

    DTIC Science & Technology

    1982-07-13

    A12i 299 COMPOSITE DEFECT SIGNIFICANCE(U) MATERIALS SCIENCES 1/1 \\ CORP SPRING HOUSE PA S N CHATTERJEE ET AL. 13 JUL 82 MSC/TFR/1288/il87 NADC-80848...Directorate 30 Sensors & Avionics Technology Directorate 40 Communication & Navigation Technology Directorate 50 Software Computer Directorate 60 Aircraft ...instructions concerning commercial products herein do not constitute an endorsement by the Government nor do they convey or imply the license or right to use

  2. Defect mapping system

    DOEpatents

    Sopori, B.L.

    1995-04-11

    Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities. 20 figures.

  3. Defect mapping system

    DOEpatents

    Sopori, Bhushan L.

    1995-01-01

    Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities.

  4. Defects at semiconductor surfaces

    NASA Astrophysics Data System (ADS)

    Henzler, Martin

    1985-04-01

    Low Energy Electron Diffraction (LEED) is widely used for detection of periodicity at the surface and of atom arrangement within the unit cell. Experiments and results, however, are increasing, which use the spot profile analysis (SPA-LEED) for the study of nonperiodic surfaces. Here the kinematical approximation provides a wider range of validity than expected. For semiconductors defects are especially important, since the surface states in the gap are determined or strongly influenced by almost any kind of defects at the surface. Atomic steps at the interface {Si}/{SiO2} have been shown to be correlated with many electronic properties of MOS devices like mobility, interface states and fixed charge. The epitaxy on Si and GaAs has been studied with LEED and RHEED, showing the density of the nuclei during formation of a layer and the layer-by-layer growth. The formation of metal suicides in the monolayer range is accompanied by many different superstructures and other rearrangements. It is demonstrated, that the new high resolution instruments provide additional qualitative and quantitative informations on any kind of surface defects.

  5. Mask Blank Defect Detection

    SciTech Connect

    Johnson, M A; Sommargren, G E

    2000-02-04

    Mask blanks are the substrates that hold the master patterns for integrated circuits. Integrated circuits are semiconductor devices, such as microprocessors (mPs), dynamic random access memory (DRAMs), and application specific integrated circuits (ASICs) that are central to the computer, communication, and electronics industries. These devices are fabricated using a set of master patterns that are sequentially imaged onto light-sensitive coated silicon wafers and processed to form thin layers of insulating and conductive materials on top of the wafer. These materials form electrical paths and transistors that control the flow of electricity through the device. For the past forty years the semiconductor industry has made phenomenal improvements in device functionality, compactness, speed, power, and cost. This progress is principally due to the exponential decrease in the minimum feature size of integrated circuits, which has been reduced by a factor of {radical}2 every three years. Since 1992 the Semiconductor Industry Association (SIA) has coordinated the efforts of producing a technology roadmap for semiconductors. In the latest document, ''The International Technology Roadmap for Semiconductors: 1999'', future technology nodes (minimum feature sizes) and targeted dates were specified and are summarized in Table 1. Lithography is the imaging technology for producing a de-magnified image of the mask on the wafer. A typical de-magnification factor is 4. Mask blank defects as small as one-eighth the equivalent minimum feature size are printable and may cause device failure. Defects might be the result of the surface preparation, such as polishing, or contamination due to handling or the environment. Table 2 shows the maximum tolerable defect sizes on the mask blank for each technology node. This downward trend puts a tremendous burden on mask fabrication, particularly in the area of defect detection and reduction. A new infrastructure for mask inspection will be

  6. Study of lattice defect vibration

    NASA Technical Reports Server (NTRS)

    Elliott, R. J.

    1969-01-01

    Report on the vibrations of defects in crystals relates how defects, well localized in a crystal but interacting strongly with the other atoms, change the properties of a perfect crystal. The methods used to solve defect problems relate the properties of an imperfect lattice to the properties of a perfect lattice.

  7. Thermal properties of defective fullerene

    NASA Astrophysics Data System (ADS)

    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.

  8. Topological Defects by Size Polydispersity

    NASA Astrophysics Data System (ADS)

    Yao, Zhenwei; Olvera de La Cruz, Monica

    2014-03-01

    The engineering of defects in crystalline matter introduces entirely new physical properties of materials. The fascinating possible applications of defects, known as topological defects, provide great motivations to perform fundamental investigations to uncover their role on the physical properties of various systems. Here we investigate topological defects in size polydispersity on flat surfaces. Our simulations show that in polydispersed systems topological defects play the role of order-restoring. The perfect hexagonal lattice beyond a small defective region around the impurity particle is well protected. Moreover, size polydispersity is shown numerically here to be an essential ingredient to understand short-range attractions between like-charge disclinations. Our study suggests the promising potential of size polydispersity to engineer defects in real systems. We thank the support of the Office of the Secretary of Defense under the NSSEFF program award number FA9550-10-1-0167.

  9. Single ventricle cardiac defect.

    PubMed

    Eren, Bulent; Turkmen, Nursel; Turkmen, Nurset; Fedakar, Recep; Senel, Berna; Cetin, Volkan; Cetin, Volkn

    2010-05-01

    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.

  10. Ultrasound anal sphincter defects and 3D anal pressure defects.

    PubMed

    Mion, F; Garros, A; Damon, H; Roman, S

    2017-04-13

    We read with interest the paper by Rezaie et al. on the use of 3D high definition anorectal manometry (3DARM) to detect anal sphincter defects in patients with faecal incontinence [1]. In their series of 39 patients, they described a new metrics to define anal pressure defect (defect of at least 18° of the 25 mmHg isobaric contour on anal resting pressures), and then compared the results of pressure defects determined by 3DARM and 3D anal ultrasound results. They found a rather good negative predictive value of manometry to eliminate the presence of ultrasound anal sphincter defects (92%), and suggested the possibility to use 3DARM to rule out anal sphincter defects and avoid the need of anal ultrasound in selected patients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. [Congenital defects and incapacity].

    PubMed

    Jouve de la Barreda, Nicolás

    2009-01-01

    As a whole the congenital defects constitute an important section of the medical attention affecting near 3% of the population. A 15% of spontaneous abortions take place of which the greater frequency corresponds to the chromosome anomalies (25%) and the monogenic mutations (20%) and in a lesser extent to the effects of teratogenic agents. Between the genetic causes determining the congenital defects the mutations that affect genes acting in the early stages of development occupy a main place. These alterations can affect to homeotic genes or monogenic systems that act during the critical phases of the organogenesis. It seems evident that an alteration in the expression of a necessary gene for the appearance of a morphogenetic change constitutes the angular stone to understand resurging of a malformation or discapacity. In the last years has been demonstrated the importance of the teratogenic or environmental agents on the delicate internal physiological balance during the critical stages of the development. In this context must be included the inductive environmental factors inducing epigenetic modifications in the early stage of the development of the embryos produced by fertilization in vitro.

  12. Dipole defects in beryl

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    Dipole defects in gamma irradiated and thermally treated beryl (Be3Al2Si6O18) 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.

  13. Reconstruction of perineal defects

    PubMed Central

    Baker, RJ; Muneer, A; Mosahebi, A

    2013-01-01

    Introduction Perineal defects are commonly encountered in an oncological setting although they may also present as a result of trauma and infection (eg following Fournier’s gangrene). Reconstruction of these poses functional as well as aesthetic challenges. Skin coverage and tissue volume may both be required in addition to anogenital preservation or reconstruction. General prerequisites of an adequate reconstruction of perineal defects include provision of skin cover, well vascularised tissue to fill the dead space (reducing fluid collection and infection), vulvovaginal reconstruction and no faecal or urinary contamination. Methods A literature search was performed using PubMed and MEDLINE®. The search terms included ‘perineal defects’, ‘perineal reconstruction’, ‘perforator flaps for perineum’, ‘vulval flaps’, ‘secondary healing of wound’ and ‘vacuum assisted closure’. Backward chaining of reference lists from retrieved papers was also used to expand the search. Findings Modern developments have led to an increased expectation in improved quality of life as the main goal of reconstruction, therefore necessitating surgery with less morbidity and early return to normal activity. Progress in microsurgical procedures has been the main recent advance in perineal reconstruction and, in future, refinements in perforator flap design and tissue engineering techniques will lead to even better reconstructions. PMID:24165333

  14. Topological defects in extended inflation

    NASA Technical Reports Server (NTRS)

    Copeland, Edmund J.; Kolb, Edward W.; Liddle, Andrew R.

    1990-01-01

    The production of topological defects, especially cosmic strings, in extended inflation models was considered. 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.

  15. Who named the quantum defect?

    SciTech Connect

    Rau, A.R.P.; Inokuti, M.

    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.

  16. Defective endometrial receptivity.

    PubMed

    Revel, Ariel

    2012-05-01

    The endometrium is one of the most fascinating tissues in the human body. Its sole purpose is to enable implantation of an embryo during a relatively short window of opportunity in the menstrual cycle. It is becoming clear that overcoming the current bottleneck in improvements to assisted reproductive techniques will require a closer look at the interface between uterus and embryo. Indeed, embryo implantation requires a cross talk with a receptive endometrium. Using sonography, hysteroscopy and endometrial biopsy we can learn about anatomical and functional markers of endometrial receptivity. This article reviews the factors which might cause defective endometrial receptivity. These include uterine polyps, septa, leiomyomata and adhesions. The effect of thin endometrium, endometriosis and hydrosalpinx is also described. Finally contemporary investigation of molecular markers of endometrial receptivity is described. Improving embryo implantation by a closer look inside the uterus is the key to increasing pregnancy rates in IVF.

  17. A Clinical and Radiographic Evaluation of Periodontal Regenerative Potential of PerioGlas®: A Synthetic, Resorbable Material in Treating Periodontal Infrabony Defects

    PubMed Central

    Chacko, Neelathil Lisa; Abraham, Sathish; Rao, H N Shama; Sridhar, N; Moon, Ninad; Barde, Dhananjay H

    2014-01-01

    Background: Study of the clinical application of bioactive glass in treating periodontal defects has been gaining momentum. Studies in the past have hypothesized that bioactive glass resulted in an improvement of bony lesion when compared with open flap debridement. Considering that there were very few studies in the Indian dental literature involving the analysis of PerioGlas®- A particulate Bioglass in intrabony defects, the present clinical trial aimed to clinically and radiographically evaluate the efficacy of PerioGlas® and compare it to open debridement as control in the treatment of human periodontal osseous (three and two wall) defects in South Indian population. Materials and Methods: Ten patients with chronic periodontitis within the age group of 30-45 years having at least two pockets with depth of ≥6 mm exhibiting vertical osseous defects were selected for the study. A total of 20 defect sites were randomly assigned to one of the two treatment modalities such that 10 sites (experimental) received PerioGlas® material after open flap debridement and 10 sites with open flap debridement (controls). Plaque index and gingival index (GI) were recorded at baseline, 6 weeks, 3 months, 6 months and 9 months, whereas probing pocket depth (PPD), clinical attachment level and gingival recession (GR) were recorded at baseline, 6 and 9 months postoperatively. Linear radiographic measurements were carried out at baseline, 6 and 9 months to evaluate the defect fill, defect resolution and change in the alveolar crest height (ACH). Results: Both experimental and control site showed a significant reduction in plaque and GI, and a slight increase in GR. The mean reduction in PPD for experimental and control site was 4.4 ± 0.34 mm and 3.2 ± 0.1 mm, respectively. Gain in clinical attachment at experimental and control site was 4.4 ± 0.21 and 3.4 ± 0.11, respectively which on comparison was statistically non-significant for both sites. The radiographic mean defect

  18. Lumber defect detection by ultrasonics

    Treesearch

    K. A. McDonald

    1978-01-01

    Ultrasonics, the technology of high-frequency sound, has been developed as a viable means for locating most defects In lumber for use in digital form in decision-making computers. Ultrasonics has the potential for locating surface and internal defects in lumber of all species, green or dry, and rough sawn or surfaced.

  19. Calculating charged defects using CRYSTAL

    NASA Astrophysics Data System (ADS)

    Bailey, Christine L.; Liborio, Leandro; Mallia, Giuseppe; Tomić, Stanko; Harrison, Nicholas M.

    2010-07-01

    The methodology for the calculation of charged defects using the CRYSTAL program is discussed. Two example calculations are used to illustrate the methodology: He+ ions in a vacuum and two intrinsic charged defects, Cu vacancies and Ga substitution for Cu, in the chalcopyrite CuGaS2.

  20. Atrial Septal Defect (For Kids)

    MedlinePlus

    ... Dictionary of Medical Words En Español What Other Kids Are Reading 7 Videos: Kids Talk About Life Video: Am I Normal? (Girls ... Train Your Temper Atrial Septal Defect KidsHealth > For Kids > Atrial Septal Defect Print A A A What's ...

  1. Facts about Ventricular Septal Defect

    MedlinePlus

    ... the lungs forces the heart and lungs to work harder. Over time, if not repaired, this defect can increase the risk for other complications, including heart failure, high blood pressure in the lungs ... » Types of Ventricular Septal Defects Click here to ...

  2. Antisite defects at oxide interfaces

    NASA Astrophysics Data System (ADS)

    Chen, Hanghui; Millis, Andrew

    We use ab initio calculations to estimate formation energies of cation (transition metal) antisite defects at oxide interfaces and to understand the basic physical effects that drive or suppress the formation of these defects. We find that antisite defects are favored in systems with substantial charge transfer across the interface, while Jahn-Teller distortions and itinerant ferromagnetism can prevent antisite defects and help stabilize atomically sharp interfaces. Our results enable identification of classes of systems that are more and less susceptible to the formation of antisite defects and motivate a range of experimental studies and further theoretical calculations to further explicate the oxide interface systems. This research was supported by National Science Foundation under Grant No. DMR-1120296 (H. Chen) and DOE-ER-046169 (A. J. Millis).

  3. Global topological k-defects

    SciTech Connect

    Babichev, E.

    2006-10-15

    We consider global topological defects in symmetry-breaking models with a noncanonical kinetic term. Apart from a mass parameter entering the potential, one additional dimensional parameter arises in such models - a kinetic mass. The properties of defects in these models are quite different from standard global domain walls, vortices, and monopoles, if their kinetic mass scale is smaller than their symmetry-breaking scale. In particular, depending on the concrete form of the kinetic term, the typical size of such a defect can be either much larger or much smaller than the size of a standard defect with the same potential term. The characteristic mass of a nonstandard defect, which might have been formed during a phase transition in the early universe, depends on both the temperature of a phase transition and the kinetic mass.

  4. Surface defects and chiral algebras

    DOE PAGES

    Córdova, Clay; Gaiotto, Davide; Shao, Shu-Heng

    2017-05-26

    Here, we investigate superconformal surface defects in four-dimensional N = 2 superconformal theories. Each such defect gives rise to a module of the associated chiral algebra and the surface defect Schur index is the character of this module. Various natural chiral algebra operations such as Drinfield-Sokolov reduction and spectral flow can be interpreted as constructions involving four-dimensional surface defects. We compute the index of these defects in the free hypermultiplet theory and Argyres-Douglas theories, using both infrared techniques involving BPS states, as well as renormalization group flows onto Higgs branches. We find perfect agreement with the predicted characters, in eachmore » case.« less

  5. Toward Intelligent Software Defect Detection

    NASA Technical Reports Server (NTRS)

    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.

  6. Holographic Chern-Simons defects

    NASA Astrophysics Data System (ADS)

    Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki

    2016-06-01

    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.

  7. Shaping solitons by lattice defects

    SciTech Connect

    Dong Liangwei; Ye Fangwei

    2010-11-15

    We demonstrate the existence of shape-preserving self-localized nonlinear modes in a two-dimensional photonic lattice with a flat-topped defect that covers several lattice sites. The balance of diffraction, defocusing nonlinearity, and optical potential induced by lattices with various forms of defects results in novel families of solitons featuring salient properties. We show that the soliton shape can be controlled by varying the shape of lattice defects. The existence domains of fundamental and vortex solitons in the semi-infinite gap expand with the defect amplitude. Vortex solitons in the semi-infinite gap with rectangular intensity distributions will break into dipole solitons when the propagation constant exceeds a critical value. In the semi-infinite and first-finite gaps, we find that lattices with rectangular defects can support stable vortex solitons which exhibit noncanonical phase structure.

  8. Holographic Chern-Simons defects

    SciTech Connect

    Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki

    2016-06-28

    Here, 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.

  9. Holographic Chern-Simons defects

    DOE PAGES

    Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; ...

    2016-06-28

    Here, 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 themore » defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.« less

  10. Mask defect verification using actinic inspection and defect mitigation technology

    SciTech Connect

    Huh, Sungmin; Kearney, Patrick; Wurm, Stefan; Goodwin, Frank; Goldberg, Kenneth; Mochi, Iacopo; Gullikson, Eric

    2009-04-14

    The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing. The successful production of defect-free masks will depend on the timely development of defect inspection tools, including both mask blank inspection tools and absorber pattern inspection tools to meet the 22 nm half-pitch node. EUV mask blanks with embedded phase defects were inspected with a reticle actinic inspection tool (AIT) and the Lasertec M7360. The Lasertec M7360 is operated at SEMA TECH's Mask blank Development Center (MBDC) in Albany, with sensitivity to multilayer defects down to 40-45 nm, which is not likely sufficient for mask blank development below the 32 nm half-pitch node. Phase defect printability was simulated to calculate the required defect sensitivity for the next generation blank inspection tool to support reticle development for the sub-32 nm half-pitch technology node. This paper will also discuss the kind of infrastructure that will be required in the development and mass production stages.

  11. Arabidopsis wat1 (walls are thin1)-mediated resistance to the bacterial vascular pathogen, Ralstonia solanacearum, is accompanied by cross-regulation of salicylic acid and tryptophan metabolism.

    PubMed

    Denancé, Nicolas; Ranocha, Philippe; Oria, Nicolas; Barlet, Xavier; Rivière, Marie-Pierre; Yadeta, Koste A; Hoffmann, Laurent; Perreau, François; Clément, Gilles; Maia-Grondard, Alessandra; van den Berg, Grardy C M; Savelli, Bruno; Fournier, Sylvie; Aubert, Yann; Pelletier, Sandra; Thomma, Bart P H J; Molina, Antonio; Jouanin, Lise; Marco, Yves; Goffner, Deborah

    2013-01-01

    Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and Verticillium albo-atrum. Introduction of NahG, the bacterial salicylic acid (SA)-degrading salicylate hydroxylase gene, into the wat1 mutant restored full susceptibility to both R. solanacearum and X. campestris pv. campestris. Moreover, SA content was constitutively higher in wat1 roots, further supporting a role for SA in wat1-mediated resistance to vascular pathogens. By combining transcriptomic and metabolomic data, we demonstrated a general repression of indole metabolism in wat1-1 roots as shown by constitutive down-regulation of several genes encoding proteins of the indole glucosinolate biosynthetic pathway and reduced amounts of tryptophan (Trp), indole-3-acetic acid and neoglucobrassicin, the major form of indole glucosinolate in roots. Furthermore, the susceptibility of the wat1 mutant to R. solanacearum was partially restored when crossed with either the trp5 mutant, an over-accumulator of Trp, or Pro35S:AFB1-myc, in which indole-3-acetic acid signaling is constitutively activated. Our original hypothesis placed cell-wall modifications at the heart of the wat1 resistance phenotype. However, the results presented here suggest a mechanism involving root-localized metabolic channeling away from indole metabolites to SA as a central feature of wat1 resistance to R. solanacearum. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

  12. Holographic Experiments on Defects

    NASA Astrophysics Data System (ADS)

    Wapler, Matthias C.

    Using the AdS/CFT correspondence, we study the anisotropic charge transport properties of both supersymmetric and nonsupersymmetric matter fields on (2+1)-dimensional defects coupled to a (3+1)-dimensional { N} = 4 SYM "heat bath." We focus on the cases of a finite external background magnetic field, finite net charge density and finite mass and their combinations. In this context, we also discuss the limitations due to operator mixing that appears in a few situations and that we ignore in our analysis. At high frequencies, we discover a spectrum of quasiparticle resonances due to the magnetic field and finite density and at small frequencies, we perform a Drude-like expansion around the DC limit. Both of these regimes display many generic features and some features that we attribute to strong coupling, such as a minimum DC conductivity and an unusual behavior of the "cyclotron" and plasmon frequencies, which become related to the resonances found in the conformal case in an earlier paper. We further study the hydrodynamic regime and the relaxation properties, from which the system displays a set of different possible transitions to the collisionless regime. The mass dependence can be cast in two regimes: a generic relativistic behavior dominated by the UV and a nonlinear hydrodynamic behavior dominated by the IR. In the massless case, we furthermore extend earlier results from the literature to find an interesting selfduality under a transformation of the conductivity and the exchange of density and magnetic field.

  13. Biomaterials in periodontal osseous defects

    PubMed Central

    Lal, Nand; Dixit, Jaya

    2012-01-01

    Introduction Osseous defects in periodontal diseases require osseous grafts and guided tissue regeneration (GTR) using barrier membranes. The present study was undertaken with the objectives to clinically evaluate the osteogenic potential of hydroxyapatite (HA), cissus quadrangularis (CQ), and oxidized cellulose membrane (OCM) and compare with normal bone healing. Materials and Methods Twenty subjects with periodontitis in the age group ranging from 20 years to 40 years were selected from our outpatient department on the basis of presence of deep periodontal pockets, clinical probing depth ≥5 mm, vertical osseous defects obvious on radiograph and two- or three-walled involvement seen on surgical exposure. Infrabony defects were randomly divided into four groups on the basis of treatment to be executed, such that each group comprised 5 defects. Group I was control, II received HA, III received CQ and IV received OCM. Probing depth and attachment level were measured at regular months after surgery. Defects were re-exposed using crevicular incisions at 6 months. Results There was gradual reduction in the mean probing pocket depth in all groups, but highly significant in the site treated with HA. Gain in attachment level was higher in sites treated with HA, 3.2 mm at 6 months. Conclusion Hydroxyapatite and OCM showed good reduction in pocket depth, attachment level gain and osseous defect fill. Further study should be conducted by using a combination of HA and OCM in periodontal osseous defects with growth factors and stem cells. PMID:25756030

  14. Biomaterials in periodontal osseous defects.

    PubMed

    Lal, Nand; Dixit, Jaya

    2012-01-01

    Osseous defects in periodontal diseases require osseous grafts and guided tissue regeneration (GTR) using barrier membranes. The present study was undertaken with the objectives to clinically evaluate the osteogenic potential of hydroxyapatite (HA), cissus quadrangularis (CQ), and oxidized cellulose membrane (OCM) and compare with normal bone healing. Twenty subjects with periodontitis in the age group ranging from 20 years to 40 years were selected from our outpatient department on the basis of presence of deep periodontal pockets, clinical probing depth ≥5 mm, vertical osseous defects obvious on radiograph and two- or three-walled involvement seen on surgical exposure. Infrabony defects were randomly divided into four groups on the basis of treatment to be executed, such that each group comprised 5 defects. Group I was control, II received HA, III received CQ and IV received OCM. Probing depth and attachment level were measured at regular months after surgery. Defects were re-exposed using crevicular incisions at 6 months. There was gradual reduction in the mean probing pocket depth in all groups, but highly significant in the site treated with HA. Gain in attachment level was higher in sites treated with HA, 3.2 mm at 6 months. Hydroxyapatite and OCM showed good reduction in pocket depth, attachment level gain and osseous defect fill. Further study should be conducted by using a combination of HA and OCM in periodontal osseous defects with growth factors and stem cells.

  15. 2010 Defects in Semiconductors GRC

    SciTech Connect

    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.

  16. Microtubule defects & Neurodegeneration.

    PubMed

    Baird, Fiona J; Bennett, Craig L

    2013-12-06

    One of the major challenges facing the long term survival of neurons is their requirement to maintain efficient axonal transport over long distances. In humans as large, long-lived vertebrates, the machinery maintaining neuronal transport must remain efficient despite the slow accumulation of cell damage during aging. Mutations in genes encoding proteins which function in the transport system feature prominently in neurologic disorders. Genes known to cause such disorders and showing traditional Mendelian inheritance have been more readily identified. It has been more difficult, however, to isolate factors underlying the complex genetics contributing to the more common idiopathic forms of neurodegenerative disease. At the heart of neuronal transport is the rail network or scaffolding provided by neuron specific microtubules (MTs). The importance of MT dynamics and stability is underscored by the critical role tau protein plays in MT-associated stabilization versus the dysfunction seen in Alzheimer's disease, frontotemporal dementia and other tauopathies. Another example of the requirement for tight regulation of MT dynamics is the need to maintain balanced levels of post-translational modification of key MT building-blocks such as α-tubulin. Tubulins require extensive polyglutamylation at their carboxyl-terminus as part of a novel post-translational modification mechanism to signal MT growth versus destabilization. Dramatically, knock-out of a gene encoding a deglutamylation family member causes an extremely rapid cell death of Purkinje cells in the ataxic mouse model, pcd. This review will examine a range of neurodegenerative conditions where current molecular understanding points to defects in the stability of MTs and axonal transport to emphasize the central role of MTs in neuron survival.

  17. Self healing of defected graphene

    SciTech Connect

    Chen, Jianhui; Shi, Tuwan; Cai, Tuocheng; Wu, Xiaosong; Yu, Dapeng; Xu, Tao; Sun, Litao

    2013-03-11

    For electronics applications, defects in graphene are usually undesirable because of their ability to scatter charge carriers, thereby reduce the carrier mobility. It would be extremely useful if the damage can be repaired. In this work, we employ Raman spectroscopy, X-ray photoemission spectroscopy, transmission electron microscopy, and electrical measurements to study defects in graphene introduced by argon plasma bombardment. We have found that majority of these defects can be cured by a simple thermal annealing process. The self-healing is attributed to recombination of mobile carbon adatoms with vacancies. With increasing level of plasma induced damage, the self-healing becomes less effective.

  18. Care and Treatment for Congenital Heart Defects

    MedlinePlus

    ... Physical Activity Recommendations for Heart Health • Tools & Resources Web Booklets on Congenital Heart Defects These online publications ... to you or your child’s defect and concerns. Web Booklet: Adults With Congenital Heart Defects Web Booklet: ...

  19. Effects of defects in composite structures

    NASA Technical Reports Server (NTRS)

    Sendeckyj, G. P.

    1983-01-01

    The effect of defects in composite structures is addressed. Defects in laminates such as wrinkles, foreign particles, scratches and breaks are discussed. Effects of plygap plywaviness and machining defects are also studied.

  20. Reproduction and Survival After Cardiac Defect Repair

    ClinicalTrials.gov

    2016-02-17

    Cardiovascular Diseases; Heart Diseases; Defect, Congenital Heart; Aortic Valve Stenosis; Transposition of Great Vessels; Ductus Arteriosus, Patent; Heart Septal Defects, Atrial; Heart Septal Defects, Ventricular; Down Syndrome; Tetralogy of Fallot; Pulmonic Stenosis; Coarctation of Aorta

  1. Playing with defects in metals

    NASA Astrophysics Data System (ADS)

    Li, Xiuyan; Lu, K.

    2017-07-01

    Xiuyan Li and K. Lu discuss a strategy, alternative to alloying, to tailor the mechanical properties of metals. By engineering defects, metals with bespoke performance might be obtained while reducing the materials' compositional complexity.

  2. Atrial Septal Defect (For Kids)

    MedlinePlus

    ... wall called the septum that normally separates the blue and red blood. In a person with an atrial septal defect, there's an opening in that wall. This hole in the wall lets oxygen-rich blood from ...

  3. Sequential detection of web defects

    DOEpatents

    Eichel, Paul H.; Sleefe, Gerard E.; Stalker, K. Terry; Yee, Amy A.

    2001-01-01

    A system for detecting defects on a moving web having a sequential series of identical frames uses an imaging device to form a real-time camera image of a frame and a comparitor to comparing elements of the camera image with corresponding elements of an image of an exemplar frame. The comparitor provides an acceptable indication if the pair of elements are determined to be statistically identical; and a defective indication if the pair of elements are determined to be statistically not identical. If the pair of elements is neither acceptable nor defective, the comparitor recursively compares the element of said exemplar frame with corresponding elements of other frames on said web until one of the acceptable or defective indications occur.

  4. Atrial Septal Defect (For Teens)

    MedlinePlus

    ... septal defect (pronounced: AY-tree-ul SEP-tul DEE-fekt), or ASD for short, is sometimes referred ... can be treated with cardiac catheterization (pronounced: CAR-dee-ack cath-uh-turr-ih-ZAY-shun), in ...

  5. Congenital Heart Defects (For Parents)

    MedlinePlus

    ... heart, lungs, and blood vessels make up the circulatory system . The heart is the central pump of this ... Heart Defects Getting an EKG (Video) Your Heart & Circulatory System Heart Murmurs Mitral Valve Prolapse Movie: Heart & Circulatory ...

  6. Birth Defects Research and Tracking

    MedlinePlus

    ... this? Submit Button Information For… Media Policy Makers Research and Tracking Recommend on Facebook Tweet Share Compartir ... to help prevent them. Importance of Tracking and Research Tracking: Birth defects tracking systems identify babies born ...

  7. Congenital Heart Defects (For Parents)

    MedlinePlus

    ... heart, lungs, and blood vessels make up the circulatory system . The heart is the central pump of this ... Heart Defects Getting an EKG (Video) Your Heart & Circulatory System Heart Murmurs Mitral Valve Prolapse Movie: Heart & Circulatory ...

  8. Genital and Urinary Tract Defects

    MedlinePlus

    ... unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our ... experts Calculating your due date Ovulation calendar Order bereavement materials News Moms Need Blog News & Media News ...

  9. Congenital Heart Defects and CCHD

    MedlinePlus

    ... unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our ... experts Calculating your due date Ovulation calendar Order bereavement materials News Moms Need Blog News & Media News ...

  10. Low quantum defect laser performance

    NASA Astrophysics Data System (ADS)

    Bowman, Steven R.

    2017-01-01

    Low quantum defect lasers are possible using near-resonant optical pumping. This paper examines the laser material performance as the quantum defect of the laser is reduced. A steady-state model is developed, which incorporates the relevant physical processes in these materials and predicts extraction efficiency and waste heat generation. As the laser quantum defect is reduced below a few percent, the impact of fluorescence cooling must be included in the analysis. The special case of a net zero quantum defect laser is examined in detail. This condition, referred to as the radiation balance laser (RBL), is shown to provide two orders of magnitude lower heat generation at the cost of roughly 10% loss in extraction efficiency. Numerical examples are presented with the host materials Yb:YAG and Yb:Silica. The general conditions, which yield optimal laser efficiency, are derived and explored.

  11. Stable line defects in silicene

    NASA Astrophysics Data System (ADS)

    Ghosh, Dibyajyoti; Parida, Prakash; Pati, Swapan K.

    2015-11-01

    Line defects in two-dimensional (2D) materials greatly modulate various properties of their pristine form. Using ab initio molecular dynamics (AIMD) simulations, we investigate the structural reconstructions of different kinds of grain boundaries in the silicene sheets. It is evident that depending upon the presence of silicon adatoms and edge shape of grain boundaries (i.e., armchair or zigzag), stable extended line defects (ELDs) can be introduced in a controlled way. Further studies show the stability of these line-defects in silicene, grown on Ag(111) surface at room-temperature. Importantly, unlike most of the 2D sheet materials such as graphene and hexagonal boron nitride, 5-5-8 line defects modify the nonmagnetic semimetallic pristine silicene sheet to spin-polarized metal. As ferromagnetically ordered magnetic moments remain strongly localized at the line defect, a one-dimensional spin channel gets created in silicene. Interestingly, these spin channels are quite stable because, unlike the edge of nanoribbons, structural reconstruction or contamination cannot destroy the ordering of magnetic moments here. Zigzag silicene nanoribbons with a 5-5-8 line defect also exhibit various interesting electronic and magnetic properties depending upon their width as well as the nature of the magnetic coupling between edge and defect spin states. Upon incorporation of other ELDs, such as 4-4-4 and 4-8 defects, 2D sheets and nanoribbons of silicene show a nonmagnetic metallic or semiconducting ground state. Highlighting the controlled formation of ELDs and consequent emergence of technologically important properties in silicene, we propose new routes to realize silicene-based nanoelectronic and spintronic devices.

  12. Intrauterine infections and birth defects.

    PubMed

    Zheng, Xiao-Ying; Zhang, Ting; Wang, Yi-Fei; Xu, Chen; Chen, Gong; Xin, Ruo-Lei; Chen, Jia-Peng; Hu, Xu-Mei; Yang, Qing; Song, Xin-Ming; Pang, Li-Hua; Ji, Ying; Sun, Hong-Mei; Zhang, Lei; Liu, Ju-Fen; Guo, Yan-Ling; Zhang, Yan

    2004-12-01

    Intrauterine infection is an important cause of some birth defects worldwide. The most common pathogens include rubella virus, cytomegaloviurs, ureaplasma urealyticum, toxoplasma, etc. General information about these pathogens in epidemiology, consequence of birth defects, and the possible mechanisms in the progress of birth defects, and the interventions to prevent or treat these pathogens' infections are described. The infections caused by rubella virus, cytomegaloviurs, ureaplasma urealyticum, toxoplasma, etc. are common, yet they are proved to be fatal during the pregnant period, especially during the first trimester. These infections may cause sterility, abortion, stillbirth, low birth weight, and affect multiple organs that may induce loss of hearing and vision, even fetal deformity and the long-term effects. These pathogens' infections may influence the microenvironment of placenta, including levels of enzymes and cytokines, and affect chondriosome that may induce the progress of birth defect. Early diagnosis of infections during pregnancy should be strengthened. There are still many things to be settled, such as the molecular mechanisms of birth defects, the effective vaccines to certain pathogens. Birth defect researches in terms of etiology and the development of applicable and sensitive pathogen detection technology and methods are imperative.

  13. Topological defects from the multiverse

    SciTech Connect

    Zhang, Jun; Blanco-Pillado, Jose J.; Garriga, Jaume; Vilenkin, Alexander

    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.

  14. Topological defects from the multiverse

    SciTech Connect

    Zhang, Jun; Vilenkin, Alexander; Blanco-Pillado, Jose J.

    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.

  15. Repairing native defects on EUV mask blanks

    NASA Astrophysics Data System (ADS)

    Lawliss, Mark; Gallagher, Emily; Hibbs, Michael; Seki, Kazunori; Isogawa, Takeshi; Robinson, Tod; LeClaire, Jeff

    2014-10-01

    Mask defectivity is a serious problem for all lithographic masks, but especially for EUV masks. Defects in the EUV blank are particularly challenging because their elimination is beyond control of the mask fab. If defects have been identified on a mask blank, patterns can be shifted to place as many blank defects as possible in regions where printing impact will be eliminated or become unimportant. For those defects that cannot be mitigated through pattern shift, repair strategies must be developed. Repairing defects that occur naturally in the EUV blank is challenging because the printability of these defects varies widely. This paper describes some types of native defects commonly found and begins to outline a triage strategy for defects that are identified on the blank. Sample defects best suited to nanomachining repair are treated in detail: repairs are attempted, characterized using mask metrology and then tested for printability. Based on the initial results, the viability of repairing EUV blank native defects is discussed.

  16. Defects formation and wave emitting from defects in excitable media

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Xu, Ying; Tang, Jun; Wang, Chunni

    2016-05-01

    Abnormal electrical activities in neuronal system could be associated with some neuronal diseases. Indeed, external forcing can cause breakdown even collapse in nervous system under appropriate condition. The excitable media sometimes could be described by neuronal network with different topologies. The collective behaviors of neurons can show complex spatiotemporal dynamical properties and spatial distribution for electrical activities due to self-organization even from the regulating from central nervous system. Defects in the nervous system can emit continuous waves or pulses, and pacemaker-like source is generated to perturb the normal signal propagation in nervous system. How these defects are developed? In this paper, a network of neurons is designed in two-dimensional square array with nearest-neighbor connection type; the formation mechanism of defects is investigated by detecting the wave propagation induced by external forcing. It is found that defects could be induced under external periodical forcing under the boundary, and then the wave emitted from the defects can keep balance with the waves excited from external forcing.

  17. Photo-induced Defects in Semiconductors

    NASA Astrophysics Data System (ADS)

    Redfield, David; Bube, Richard H.

    2006-03-01

    1. Introduction: metastable defects; 2. III-V compounds: DX2 and EL2 centers; 3. Other crystalline materials; 4. Hydrogenated amorphous silicon: properties of defects; 5. Hydrogenated amorphous silicon: photo-induced defect kinetics and processes; 6. Other amorphous semiconductors; 7. Photo-induced defect effects in devices; References; Index.

  18. Effective actions for bosonic topological defects

    NASA Technical Reports Server (NTRS)

    Gregory, Ruth

    1990-01-01

    A gauge field theory is considered which admits p-dimensional topological defects, expanding the equations of motion in powers of the defect thickness. In this way an effective action and effective equation of motion is derived for the defect in terms of the coordinates of the p-dimensional worldsurface defined by the history of the core of the defect.

  19. Defect CFTs and holographic multiverse

    SciTech Connect

    Fiol, Bartomeu

    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.

  20. Actin cytoskeletal defects in immunodeficiency

    PubMed Central

    Moulding, Dale A; Record, Julien; Malinova, Dessislava; Thrasher, Adrian J

    2013-01-01

    The importance of the cytoskeleton in mounting a successful immune response is evident from the wide range of defects that occur in actin-related primary immunodeficiencies (PIDs). Studies of these PIDs have revealed a pivotal role for the actin cytoskeleton in almost all stages of immune system function, from hematopoiesis and immune cell development, through to recruitment, migration, intercellular and intracellular signaling, and activation of both innate and adaptive immune responses. The major focus of this review is the immune defects that result from mutations in the Wiskott-Aldrich syndrome gene (WAS), which have a broad impact on many different processes and give rise to clinically heterogeneous immunodeficiencies. We also discuss other related genetic defects and the possibility of identifying new genetic causes of cytoskeletal immunodeficiency. PMID:24117828

  1. Congenital heart defects and medical imaging.

    PubMed

    Gehin, Connie; Ragsdale, Lisa

    2013-01-01

    Radiologic technologists perform imaging studies that are useful in the diagnosis of congenital heart defects in infants and adults. These studies also help to monitor congenital heart defect repairs in adults. This article describes the development and functional anatomy of the heart, along with the epidemiology and anatomy of congenital heart defects. It also discusses the increasing population of adults who have congenital heart defects and the most effective modalities for diagnosing, evaluating, and monitoring congenital heart defects.

  2. Environmental causes of enamel defects.

    PubMed

    Brook, A H; Fearne, J M; Smith, J M

    1997-01-01

    A large number of causes of enamel defects, both environmental and genetic, have been described. However, many of these are derived from case histories and studies of individual conditions. What is needed now is a systematic investigation of the problem. The first requirement in exploring the aetiology further is the standardization of both the clinical diagnosis and the descriptive terminology. This has been provided by the Fédération Dentaire Internationale Developmental Defects of Enamel Index. Comparing studies using standardized methods, including this index, has highlighted areas for closer investigation. The total prevalence of enamel defects in a population needs to be established as a baseline for studies on aetiology. Sixty-eight per cent of 1518 school children in London have enamel defects in the permanent dentition, with 10.5% having 10 or more teeth affected and 14.6% having hypoplasia, i.e. missing enamel. These findings are in contrast to the 37% with hypoplasia found in a group of third to fifth century Romano-Britons from Dorset, England, suggesting further consideration of possible environmental and genetic differences between the two populations. An overall long-term study of dental development in low birth weight children has shown significantly more (P < 0.001) enamel defects related to major health problems during the neonatal period. By using standardized, reproducible criteria in prevalence studies to gain an overview of the problem and then studying specific groups or conditions, it is possible to identify general and specific factors in the aetiology of enamel defects and investigate further the varying role of genetic and environmental effects.

  3. Interface effects on calculated defect levels for oxide defects

    NASA Astrophysics Data System (ADS)

    Edwards, Arthur; Barnaby, Hugh; Schultz, Peter; Pineda, Andrew

    2014-03-01

    Density functional theory (DFT) has had impressive recent success predicting defect levels in insulators and semiconductors [Schultz and von Lillienfeld, 2009]. Such success requires care in accounting for long-range electrostatic effects. Recently, Komsa and Pasquarello have started to address this problem in systems with interfaces. We report a multiscale technique for calculating electrostatic energies for charged defects in oxide of the metal-oxide-silicon (MOS) system, but where account is taken of substrate doping density, oxide thickness, and gate bias. We use device modeling to calculate electric fields for a point charge a fixed distance from the interface, and used the field to numerically calculate the long-range electrostatic interactions. We find, for example, that defect levels in the oxide do depend on both the magnitude and the polarity the substrate doping density. Furthermore, below 20 Å, oxide thickness also has significant effects. So, transferring results directly from bulk calculations leads to inaccuracies up to 0.5 eV- half of the silicon band gap. We will present trends in defect levels as a function of device parameters. We show that these results explain previous experimental results, and we comment on their potential impact on models for NBTI. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the United States Department of Energy's National Nuclear Security Administration under co.

  4. Defects in metals. [Positron annihilation spectroscopy

    SciTech Connect

    Siegel, R.W.

    1982-06-01

    The application of positron annihilation spectroscopy (PAS) to the study of defects in metals has led to increased knowledge on lattice-defect properties during the past decade in two areas: the determination of atomic defect properties, particularly those of monovacancies, and the monitoring and characterization of vacancy-like microstructure development during post-irradiation and post-quench annealing. The study of defects in metals by PAS is reviewed within the context of the other available techniques for defect studies. The strengths and weaknesses of PAS as a method for the characterization of defect microstructures are considered. The additional possibilities for using the positron as a localized probe of the atomic and electronic structures of atomic defects are discussed, based upon theoretical calculations of the annihilation characteristics of defect-trapped positrons and experimental observations. Finally, the present status and future potential of PAS as a tool for the study of defects in metals is considered. 71 references, 9 figures.

  5. Facts about Atrial Septal Defect

    MedlinePlus

    ... Developmental Disabilities) be credited and notified in any public or private usage of this image. Close × Atrial Septal Defect The images are ... Developmental Disabilities) be credited and notified in any public or private usage of this image. Close Information For... ... Makers Language: English ...

  6. Photographic Screening for Eye Defects

    NASA Technical Reports Server (NTRS)

    Richardson, J.

    1985-01-01

    Images of retinas examined for characteristic patterns. Color photographs of retinas taken. Proper alinement of eye obtained by asking subject to gaze at light-emitting diode. "Red-eye" patterns in resulting color photographs examined by trained observers for signs of ocular defects. System used to check power of contact lenses and eyeglasses by taking photographs with these items in place.

  7. Birth Defects and Adolescent Pregnancies

    ERIC Educational Resources Information Center

    Walters, James

    1975-01-01

    Home economists who work with adolescents can help prepare them for responsible parenthood later in life by explaining the known causes of various birth defects; providing basic information about human genetics, prenatal nutrition, and drug and alcohol effects; and motivating adolescents to exercise increased responsibility in their sexual…

  8. Water chlorination and birth defects.

    PubMed

    Magnus, P; Jaakkola, J J; Skrondal, A; Alexander, J; Becher, G; Krogh, T; Dybing, E

    1999-09-01

    Chlorination of drinking water that contains organic compounds leads to the formation of by-products, some of which have been shown to have mutagenic or carcinogenic effects. As yet, too little is known about the possible teratogenic effects on the human fetus. We linked the Norwegian waterwork registry, containing 1994 data on chlorination practice and color (an indicator for natural organic matter), with the Medical Birth Registry for 1993-1995. The proportion of the population exposed to chlorination and a weighted mean color number in drinking water was computed for each municipality. Among 141,077 births, 2,608 (1.8%) had birth defects. In a comparison between exposed (high color; chlorination) and reference groups (low color; no chlorination), the adjusted odds ratio was 1.14 (0.99-1.31) for any malformation, 1.26 (0.61-2.62) for neural tube defects, and 1.99 (1.10-3.57) for urinary tract defects. This study provides further evidence of the role of chlorination of humic water as a potential cause of birth defects, in a country with relatively low levels of chlorination byproducts.

  9. Photographic Screening for Eye Defects

    NASA Technical Reports Server (NTRS)

    Richardson, J.

    1985-01-01

    Images of retinas examined for characteristic patterns. Color photographs of retinas taken. Proper alinement of eye obtained by asking subject to gaze at light-emitting diode. "Red-eye" patterns in resulting color photographs examined by trained observers for signs of ocular defects. System used to check power of contact lenses and eyeglasses by taking photographs with these items in place.

  10. Genetic defects of iron transport.

    PubMed

    Bannerman, R M

    1976-09-01

    Five genetic traits in man and laboratory animals have major effects on iron transport. The heterogeneous condition, hemochromatosis, in some families appears to segregate as a Mendelian trait, and is associated with defective control of intestinal iron absorption. In the very rare human autosomal recessive trait, atransferrinemia, there is an almost total lack of transferrin and gross maldistribution of iron through the body. In mice, sex-linked anemia (an X-linked recessive trait) causes iron deficiency through defective iron absorption, at the "exit" step; a similar defect probably exists in placental iron transfer. In microcytic anemia of mice, an autosomal recessive trait, iron absorption is also impaired because of a defect of iron entry into cells, which is probably generalized. Belgrade rat anemia, less understood at present, also may involve a major disorder of iron metabolism. Study of these mutations has provided new knowledge of iron metabolism and its genetic control Their phenotypic interaction with nutritional factors, especially the form and quantity of iron in the diet, may provide new insights for the study of nutrition.

  11. Delamination initiated by a defect

    NASA Astrophysics Data System (ADS)

    Biel, A.; Toftegaard, H.

    2016-07-01

    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 double cantilever beam specimens loaded with bending moments. The specimens consist of two 8 mm thick GFRP-laminates which are joined by a 3 mm thick epoxy adhesive. A thin foil close to one of the laminates is used to start the crack. For some of the specimens a defect is created by an initial load-unload operation. During this operation, a clamp is used in order to prevent crack propagation in the main direction. For the specimens without defect, the crack propagates in the middle of the adhesive layer. For the specimens with defect, the crack directly deviates into the laminate. After about 25 mm propagation in the laminate, the crack returns to the adhesive. Compared to the adhesive the fracture energy for the laminate is significantly higher.

  12. Facts about Congenital Heart Defects

    MedlinePlus

    ... into the heart, where a doctor can take measurements and pictures, do tests, or repair the problem. Sometimes the heart defect can’t be fully repaired, but these procedures can improve blood flow and the way the heart works. Causes The ...

  13. Birth Defects and Adolescent Pregnancies

    ERIC Educational Resources Information Center

    Walters, James

    1975-01-01

    Home economists who work with adolescents can help prepare them for responsible parenthood later in life by explaining the known causes of various birth defects; providing basic information about human genetics, prenatal nutrition, and drug and alcohol effects; and motivating adolescents to exercise increased responsibility in their sexual…

  14. Instabilities, defects, and defect ordering in an overdamped active nematic†

    PubMed Central

    Putzig, Elias; Redner, Gabriel S.; Baskaran, Arvind; Baskaran, Aparna

    2016-01-01

    We consider a phenomenological continuum theory for an extensile, overdamped active nematic liquid crystal, applicable in the dense regime. Constructed from general principles, the theory is universal, with parameters independent of any particular microscopic realization. We show that it exhibits two distinct instabilities, one of which arises due to shear forces, and the other due to active torques. Both lead to the proliferation of defects. We focus on the active torque bend instability and find three distinct nonequilibrium steady states including a defect-ordered nematic in which +12 disclinations develop polar ordering. We characterize the phenomenology of these phases and identify the relationship of this theoretical description to experimental realizations and other theoretical models of active nematics. PMID:26983376

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

    Treesearch

    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-...

  16. Defect-related properties of optical coatings

    NASA Astrophysics Data System (ADS)

    Cheng, Xinbin; Wang, Zhanshan

    2014-02-01

    Defects in optical coatings are a major factor degrading their performance. Based on the nature of defects, we classified them into two categories: visible defects and non-visible defects. Visible defects result from the replication of substrate imperfections or particulates within the coatings by subsequent layers and can increase scattering loss, produce critical errors in extreme ultraviolet lithography, weaken mechanical and environmental stability, and reduce laser damage resistance. Non-visible defects mainly involve a decrease in laser damage resistance but typically have no influence on other properties of optical coatings. In the case of widely used HfO2/SiO2 dielectric coatings, metallic Hf nano-clusters, off-stoichiometric HfO2 nano-clusters, or areas of high-density electronic defects have been postulated as possible sources for non-visible defects. The emphasis of this review is devoted to discussing localized defect-driven laser-induced damage (LID) in optical coatings used for nanosecond-scale pulsed laser applications, but consideration is also given to other properties of optical coatings such as scattering, environmental stability, etc. The low densities and diverse properties of defects make the systematic study of LID initiating from localized defects time-consuming and very challenging. Experimental and theoretical studies of localized defect-driven LID using artificial defects whose properties can be well controlled are highlighted.

  17. Engaging Hill-Sachs Defects

    PubMed Central

    Burns, David; Chahal, Jaskarndip; Shahrokhi, Shahram; Henry, Patrick; Wasserstein, David; Whyne, Cari; Theodoropoulos, John S.; Ogilvie-Harris, Darrell; Dwyer, Tim

    2016-01-01

    Objectives: Anatomic studies have demonstrated that bipolar glenoid and humeral bone loss have a cumulative impact on shoulder instability, and that these defects may engage in functional positions depending on their size, location, and orientation, potentially resulting in failure of stabilization procedures. Determining which lesions pose a risk for engagement remains a challenge, with arthroscopic assessment and Itoi’s 3DCT based glenoid track method being the accepted approaches at this time. The purpose of this study was to investigate the interaction of humeral and glenoid bone defects on shoulder engagement in a cadaveric model. Two alternative approaches to predicting engagement were evaluated; 1) CT scanning the shoulder in abduction and external rotation 2) measurement of Bankart lesion width and a novel parameter, the intact anterior articular angle (IAAA), on conventional 2D multi-plane reformats. The results of these two approaches were compared to the results obtained using Itoi’s glenoid track method for predicting engagement. Methods: Hill-Sachs and Bony Bankart defects of varying size were created in 12 cadaveric upper limbs, producing 45 bipolar defect combinations. The shoulders were assessed for engagement using cone beam CT in various positions of function, from 30 to 90 degrees of both abduction and external rotation. The humeral and glenoid defects were characterized by measurement of their size, location, and orientation. Diagnostic performance measures for predicting engagement were calculated for both the abduction external rotation scan and 2D IAAA approaches using the glenoid track method as reference standard. Results: Engagement was predicted by Itoi’s glenoid track method in 24 of 45 specimens (53%). The abduction external rotation CT scan performed at 60 degrees of glenohumeral abduction (corresponding to 90 degrees of abduction relative to the trunk) and 90 degrees of external rotation predicted engagement accurately in 43 of

  18. 7 CFR 52.780 - Defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Factors of Quality § 52.780 Defects. (a) General. The factor of defects refers to the degree of freedom from harmless extraneous...

  19. 7 CFR 52.780 - Defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Factors of Quality § 52.780 Defects. (a) General. The factor of defects refers to the degree of freedom from harmless extraneous...

  20. 7 CFR 51.2659 - Condition defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades for Sweet Cherries 1 Definitions § 51.2659 Condition defects. Condition defects means... soft cherries and such factors as pitting, shriveling, sunken areas, brown discoloration and...

  1. Atrioventricular canal (endocardial cushion defect) (image)

    MedlinePlus

    Endocardial cushion defect is an abnormal heart condition which occurs during the development of the baby. In this condition ... mix causing the heart to work harder. Endocardial cushion defect is strongly associated with several genetic abnormalities.

  2. Automatic classification of blank substrate defects

    NASA Astrophysics Data System (ADS)

    Boettiger, Tom; Buck, Peter; Paninjath, Sankaranarayanan; Pereira, Mark; Ronald, Rob; Rost, Dan; Samir, Bhamidipati

    2014-10-01

    Mask preparation stages are crucial in mask manufacturing, since this mask is to later act as a template for considerable number of dies on wafer. Defects on the initial blank substrate, and subsequent cleaned and coated substrates, can have a profound impact on the usability of the finished mask. This emphasizes the need for early and accurate identification of blank substrate defects and the risk they pose to the patterned reticle. While Automatic Defect Classification (ADC) is a well-developed technology for inspection and analysis of defects on patterned wafers and masks in the semiconductors industry, ADC for mask blanks is still in the early stages of adoption and development. Calibre ADC is a powerful analysis tool for fast, accurate, consistent and automatic classification of defects on mask blanks. Accurate, automated classification of mask blanks leads to better usability of blanks by enabling defect avoidance technologies during mask writing. Detailed information on blank defects can help to select appropriate job-decks to be written on the mask by defect avoidance tools [1][4][5]. Smart algorithms separate critical defects from the potentially large number of non-critical defects or false defects detected at various stages during mask blank preparation. Mechanisms used by Calibre ADC to identify and characterize defects include defect location and size, signal polarity (dark, bright) in both transmitted and reflected review images, distinguishing defect signals from background noise in defect images. The Calibre ADC engine then uses a decision tree to translate this information into a defect classification code. Using this automated process improves classification accuracy, repeatability and speed, while avoiding the subjectivity of human judgment compared to the alternative of manual defect classification by trained personnel [2]. This paper focuses on the results from the evaluation of Automatic Defect Classification (ADC) product at MP Mask

  3. Window defect planar mapping technique

    NASA Technical Reports Server (NTRS)

    Minton, F. R.; Minton, U. O. (Inventor)

    1976-01-01

    A method of planar mapping defects in a window having an edge surface and a planar surface. The method is comprised of steps for mounting the window on a support surface. Then a light sensitive paper is placed adjacent to the window surface. A light source is positioned adjacent to the window edge. The window is then illuminated with the source of light for a predetermined interval of time. Defects on the surface of the glass, as well as in the interior of the glass are detected by analyzing the developed light sensitive paper. The light source must be in the form of optical fibers or a light tube whose light transmitting ends are placed near the edge surface of the window.

  4. Defect tolerant transmission lithography mask

    DOEpatents

    Vernon, Stephen P.

    2000-01-01

    A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

  5. Reconstructive options for periocular defects.

    PubMed

    Jewett, B S; Shockley, W W

    2001-06-01

    Reconstruction of the periorbital area following skin cancer excision requires a thorough knowledge of orbital anatomy and eyelid function. Reconstructive procedures should maintain the function of periorbital structures while attempting to achieve optimal cosmesis. Generally, eyelid reconstruction can be considered in terms of the thickness and overall size of the defect. Both the anterior and posterior lamella should be restored, and at least one of these layers needs to be vascularized. The integrity of the canthal tendons should also be addressed. If severed, the tendons should be attached to bony landmarks in order to recreate the proper curvature of the eyelid against the globe. Finally, defects involving the lacrimal system should be assessed and properly reconstituted.

  6. Why Search for Congenital Defects?

    PubMed Central

    Collins, John F.

    1966-01-01

    The causation of congenital malformation is receiving increased study. In Canada, epidemiologic surveys are being planned, based upon the institution of Provincial Registries to which physicians and other agencies will voluntarily report cases coming to their attention. The literature in regard to prevalence studies of congenital cardiac defects in school children is reviewed. Over the past 25 years, studies employing the proposed technique demonstrated a rising trend, from 1.4 per 1000 to 2.6 per 1000. By contrast, specific surveys for congenital cardiac defect carried out by expert personnel using radiographs and electrocardiographs, resulted in essentially uniform rates, approximating 5 to 6 per 1000. It is concluded that the latter is a superior technique of epidemiologic survey over the “Central Registry” method, and should command a due proportion of health resources directed towards congenital malformation research. PMID:5914837

  7. Cooperation and Defection in Ghetto

    NASA Astrophysics Data System (ADS)

    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. Inspection of lithographic mask blanks for defects

    DOEpatents

    Sommargren, Gary E.

    2001-01-01

    A visible light method for detecting sub-100 nm size defects on mask blanks used for lithography. By using optical heterodyne techniques, detection of the scattered light can be significantly enhanced as compared to standard intensity detection methods. The invention is useful in the inspection of super-polished surfaces for isolated surface defects or particulate contamination and in the inspection of lithographic mask or reticle blanks for surface defects or bulk defects or for surface particulate contamination.

  9. COMPARISON OF SELECTED WELD DEFECT EXTRACTION METHODS

    SciTech Connect

    Sikora, R.; Baniukiewicz, P.; Chady, T.; Rucinski, W.; Swiadek, K.; Caryk, M.; Lopato, P.

    2008-02-28

    This paper presents three different methods of welding defects detection from radiographs. First two methods are dedicated for extraction of flaws directly from radiograms. Fuzzy logic system considers whether the pixel belongs to crack (or background) using defects probability maps together with simple fuzzy rules. Neural network method uses knowledge gathered from radiographs with known defects. Indirect method extracts defects by subtracting background from the radiograph and next using various local thresholding methods.

  10. Comparison of Selected Weld Defect Extraction Methods

    NASA Astrophysics Data System (ADS)

    Sikora, R.; Baniukiewicz, P.; Chady, T.; Ruciński, W.; Świadek, K.; Caryk, M.; Lopato, P.

    2008-02-01

    This paper presents three different methods of welding defects detection from radiographs. First two methods are dedicated for extraction of flaws directly from radiograms. Fuzzy logic system considers whether the pixel belongs to crack (or background) using defects probability maps together with simple fuzzy rules. Neural network method uses knowledge gathered from radiographs with known defects. Indirect method extracts defects by subtracting background from the radiograph and next using various local thresholding methods.

  11. Sinus Venosus Atrial Septal Defect

    DTIC Science & Technology

    2010-04-01

    chest CT was performed to evaluate for pulmonary embolism (figure 2). The chest radiograph (figure 1) demonstrates increased central pulmonary ...Fig. 5 Sinus venosus defect at birth . The shaded area in purple represents the sinus venosum. The anomalous right pulmonary venous anatomy...department (ED) with chest pain and an ankle fracture after being hit by a car while riding a horse. Chest imaging noted enlarged central pulmonary

  12. Visual field defects in onchocerciasis.

    PubMed Central

    Thylefors, B; Tønjum, A M

    1978-01-01

    Lesions in the posterior segment of the eye in onchocerciasis may give visual field defects, but so far no detailed investigation has been done to determine the functional visual loss. Examination of the visual fields in 18 selected cases of onchocerciasis by means of a tangent screen test revealed important visual field defects associated with lesions in the posterior segment of the eye. Involvement of the optic nerve seemed to be important, giving rise to severely constricted visual fields. Cases of postneuritic optic atrophy showed a very uniform pattern of almost completely constricted visual fields, with only 5 to 10 degree central rest spared. Papillitis gave a similar severe constriction of the visual fields. The pattern of visual fields associated with optic neuropathy in onchocerciasis indicates that a progressive lesion of the optic nerve from the periphery may be responsible for the loss of vision. The visual field defects in onchocerciasis constitute a serious handicap, which must be taken into consideration when estimating the socioeconomic importance of the disease. Images PMID:678499

  13. Photonic crystals with topological defects

    NASA Astrophysics Data System (ADS)

    Liew, Seng Fatt; Knitter, Sebastian; Xiong, Wen; Cao, Hui

    2015-02-01

    We introduce topological defects to a square lattice of elliptical cylinders. Despite the broken translational symmetry, the long-range positional order of the cylinders leads to a residual photonic band gap in the local density of optical states. However, the band-edge modes are strongly modified by the spatial variation of the ellipse orientation. The Γ -X band-edge mode splits into four regions of high intensity and the output flux becomes asymmetric due to the formation of crystalline domains with different orientation. The Γ -M band-edge mode has the energy flux circulating around the topological defect center, creating an optical vortex. By removing the elliptical cylinders at the center, we create localized defect states, which are dominated by either clockwise or counterclockwise circulating waves. The flow direction can be switched by changing the ellipse orientation. The deterministic aperiodic variation of the unit cell orientation adds another dimension to the control of light in photonic crystals, enabling the creation of a diversified field pattern and energy flow landscape.

  14. Templates Aid Removal Of Defects From Castings

    NASA Technical Reports Server (NTRS)

    Hendrickson, Robert G.

    1992-01-01

    Templates used to correlate defects in castings with local wall thicknesses. Placed on part to be inspected after coated with penetrant dye. Positions of colored spots (indicative of defects) noted. Ultrasonic inspector measures thickness of wall at unacceptable defects only - overall inspection not necessary.

  15. Electroneutral intrinsic point defects in cadmium chalcogenides

    SciTech Connect

    Kharif, Ya.L.; Kudryashov, N.I.; Strunilina, T.A.

    1987-12-01

    Low-mobility electrically neutral intrinsic point defects were observed in cadmium chalcogenides. It was shown that the concentration of these defects is proportional to the cadmium vapor pressure to the 1/3 power at a constant temperature, and a mechanism for the formation of these defects were proposed.

  16. 7 CFR 51.2659 - Condition defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Condition defects. 51.2659 Section 51.2659 Agriculture... Standards for Grades for Sweet Cherries 1 Definitions § 51.2659 Condition defects. Condition defects means... soft cherries and such factors as pitting, shriveling, sunken areas, brown discoloration and bruising...

  17. Method for mask repair using defect compensation

    DOEpatents

    Sweeney, Donald W.; Ray-Chaudhuri, Avijit K.

    2001-01-01

    A method for repair of amplitude and/or phase defects in lithographic masks. The method involves modifying or altering a portion of the absorber pattern on the surface of the mask blank proximate to the mask defect to compensate for the local disturbance (amplitude or phase) of the optical field due to the defect.

  18. Photographic guide of selected external defect indicators and associated internal defects in yellow birch

    Treesearch

    Everette D. Rast; John A. Beaton; David L. Sonderman

    1991-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow birch. Eleven types of external...

  19. Photographic guide of selected external defect indicators and associated internal defects in sugar maple

    Treesearch

    Everette D. Rast; John A. Beaton; David L. Sonderman

    1991-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for sugar maple. Eleven types of external...

  20. Second workshop role of point defects/defect complexes in silicon device fabrication

    SciTech Connect

    Not Available

    1992-01-01

    Abstracts are presented of 24 papers, arranged under the following session/panel headings: defects and impurities in commercial photovoltaic Si substrates, point defects and point defect processes, impurity gettering for Si solar cells, gettering in Si solar cells, and passivation of impurities and defects.

  1. Photographic guide of selected external defect indicators and associated internal defects in northern red oak

    Treesearch

    Everette D. Rast

    1982-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development. It illustrates and describes eight types...

  2. Photographic guide of selected external defect indicators and associated internal defects in white oak

    Treesearch

    Everette D. Rast; John A. Beaton; David L. Sonderman; David L. Sonderman

    1989-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development for white oak. It illustrates and...

  3. Photographic guide to selected external defect indicators and associated internal defects in black walnut

    Treesearch

    Everette D.Beaton John A. Rast; David L. Sonderman; David L. Sonderman

    1988-01-01

    To properly classify qr grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its develqpment for black walnut. It illustrates and...

  4. Photographic guide of selected external defect indicators and associated internal defects in yellow-poplar

    Treesearch

    Everette D. Rast; John A. Beaton; David L. Sonderman

    1991-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow-poplar. Twelve types of external...

  5. Photographic guide to selected external defect indicators and associated internal defects in black cherry

    Treesearch

    Everette D. Rast; John A. Beaton; John A. Beaton

    1985-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development for black cherry. It illustrates and...

  6. ENDEAVOUR to understand EUV buried defect printability

    NASA Astrophysics Data System (ADS)

    Seki, Kazunori; Isogawa, Takeshi; Kagawa, Masayuki; Akima, Shinji; Kodera, Yutaka; Badger, Karen; Qi, Zhengqing J.; Lawliss, Mark; Rankin, Jed; Bonam, Ravi

    2015-07-01

    NAP-PD (Native Acting Phase - Programmed Defects), otherwise known as buried program defects, with attributes very similar to native defects, are successfully fabricated using a high accuracy overlay technique. The defect detectability and visibility are analyzed with conventional phase contrast blank inspection @193 nm wavelength, pattern inspection @193 nm wavelength and SEM. The mask is also printed on wafer and printability is discussed. Finally, the inspection sensitivity and wafer printability are compared, leading to the observation that the current blank and pattern inspection sensitivity is not enough to detect all of the printable defects.

  7. The defect variance of random spherical harmonics

    NASA Astrophysics Data System (ADS)

    Marinucci, Domenico; Wigman, Igor

    2011-09-01

    The defect of a function f:M\\rightarrow {R} is defined as the difference between the measure of the positive and negative regions. In this paper, we begin the analysis of the distribution of defect of random Gaussian spherical harmonics. By an easy argument, the defect is non-trivial only for even degree and the expected value always vanishes. Our principal result is evaluating the defect variance, asymptotically in the high-frequency limit. As other geometric functionals of random eigenfunctions, the defect may be used as a tool to probe the statistical properties of spherical random fields, a topic of great interest for modern cosmological data analysis.

  8. Effects of Stone-Wales and vacancy defects in atomic-scale friction on defective graphite

    SciTech Connect

    Sun, Xiao-Yu; Wu, RunNi; Xia, Re; Chu, Xi-Hua; Xu, Yuan-Jie

    2014-05-05

    Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite.

  9. Defect disorder in UO{sub 2}

    SciTech Connect

    Hassan, A.-R.; El-Azab, Anter; Yablinsky, Clarissa; Allen, T.

    2013-08-15

    A defect disorder model has been developed to determine equilibrium off-stoichiometry and its spatial variations in UO{sub 2} crystals. The model gives the concentrations of atomic defects and electronic carriers as functions of oxygen partial pressure and temperature in the bulk and near crystal surfaces subject to an oxygen environment. Energetic parameters from published density functional theory calculations have been integrated into the defect disorder model for an accurate determination of the defect density and off-stoichiometry. The ionosorption theory has been used to couple the oxygen environment with the defect state in the crystal as we solved for the defect disorder near crystal surfaces. Contrary to the common belief that hyper-stoichiometry of UO{sub 2} is dominated by oxygen interstitials, the current model predicts that this regime is rather dominated by uranium vacancies. The model predictions also show that, in the presence of surfaces, the point defect concentrations vary by orders of magnitude in the subsurface region relative to the bulk region. Highlights: • Defect disorder in bulk UO2+x is modeled in terms of temperature and oxygen pressure. • The densities of atomic defects and electronic charge carriers are determined. • The model is extended to study the heterogeneity of defect density near crystal surfaces. • The surface effect is modeled using ionosorption theory. • The dominant defect type and off-stoichiometry profile near surface are found.

  10. Novel EUV Mask Blank Defect Repair Developments

    SciTech Connect

    Hau-Riege, S; Barty, A; Mirkarimi, P

    2003-03-31

    The development of defect-free reticle blanks is an important challenge facing the commercialization of extreme ultraviolet lithography (EUVL). The basis of EUVL reticles are mask blanks consisting of a substrate and a reflective Mo/Si multilayer. Defects on the substrate or defects introduced during multilayer deposition can result in critical phase and amplitude defects. Amplitude- or phase-defect repair techniques are being developed with the goal to repair many of these defects. In this report, we discuss progress in two areas of defect repair: (1) We discuss the effect of the residual reflectance variation over the repair zone after amplitude-defect repair on the process window. This allows the determination of the maximum tolerable residual damage induced by amplitude defect repair. (2) We further performed a quantitative assessment of the yield improvement due to defect repair. We found that amplitude- and phase-defect repair have the potential to significantly improve mask blank yield. Our calculations further show that yield can be maximized by increasing the number of Mo/Si bilayers.

  11. Resist process optimization for further defect reduction

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi; Iseki, Tomohiro; Marumoto, Hiroshi; Takayanagi, Koji; Yoshida, Yuichi; Uemura, Ryouichi; Yoshihara, Kosuke

    2012-03-01

    Defect reduction has become one of the most important technical challenges in device mass-production. Knowing that resist processing on a clean track strongly impacts defect formation in many cases, we have been trying to improve the track process to enhance customer yield. For example, residual type defect and pattern collapse are strongly related to process parameters in developer, and we have reported new develop and rinse methods in the previous papers. Also, we have reported the optimization method of filtration condition to reduce bridge type defects, which are mainly caused by foreign substances such as gels in resist. Even though we have contributed resist caused defect reduction in past studies, defect reduction requirements continue to be very important. In this paper, we will introduce further process improvements in terms of resist defect reduction, including the latest experimental data.

  12. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  13. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  14. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... container is scored only once for these two defects since the rust condition can be attributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  15. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  16. Posttraumatic cortical defect of femur.

    PubMed

    Nadarajah, Jeyaseelan; Srivastava, Deep N; Malhotra, Rajesh; Palaniswamy, Aravindh

    2013-01-01

    Posttraumatic cortical defect of bone is a rare entity which occurs in a maturing skeleton following green stick or torus fracture. Most of the cases are asymptomatic and they are detected incidentally on radiograph. These lesions usually require no treatment. However, the appearance of these lesions can mimic various pathological conditions affecting bone. Knowledge about this entity is important as it avoids unnecessary investigations. We present this case as the occurrence of this entity in femur is very rare and the child was symptomatic.

  17. On nuclear reactions in defects

    SciTech Connect

    Sienes, J.K. )

    1991-05-01

    The variability of results concerning cold fusion, together with the difficulty of explaining the observations, suggests that some nonstandard processes may be occurring. One such possibility is that nuclear reactions occur in defects of a deuterated lattice as a result of transient motions that momentarily bring deuterium atoms into close proximity. In this paper a mechanism involving shear of a one-dimensional lattice is described that illustrates this possibility. Order-of-magnitude estimates indicate that the expected fusion rate is not inconsistent with some experiments.

  18. Reconstruction of Peripelvic Oncologic Defects.

    PubMed

    Weichman, Katie E; Matros, Evan; Disa, Joseph J

    2017-10-01

    After studying this article, the participant should be able to: 1. Understand the anatomy of the peripelvic area. 2. Understand the advantages and disadvantages of performing peripelvic reconstruction in patients undergoing oncologic resection. 3. Select the appropriate local, pedicled, or free-flap reconstruction based on the location of the defect and donor-site characteristics. Peripelvic reconstruction most commonly occurs in the setting of oncologic ablative surgery. The peripelvic area contains several distinct reconstructive regions, including vagina, vulva, penis, and scrotum. Each area provides unique reconstructive considerations. In addition, prior or future radiation therapy or chemotherapy along with cancer cachexia can increase the complexity of reconstruction.

  19. Robotic atrial septal defect closure.

    PubMed

    Senay, Sahin; Gullu, Ahmet Umit; Kocyigit, Muharrem; Degirmencioglu, Aleks; Karabulut, Hasan; Alhan, Cem

    2014-01-01

    Atrial septal defect (ASD) is one of the most common congenital cardiac diseases. This pathology can be treated with percutaneous devices. However, some of the ASDs are not suitable for device closure. Also, there may be device-related late complications of transcatheter ASD closure. Currently, robotic surgical techniques allow surgeons to close ASDs in a totally endoscopic fashion with a high success rate and a low complication rate. This study demonstrates the basic concepts and technique of robotic ASD closure. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  20. Improvement in accuracy of defect size measurement by automatic defect classification

    NASA Astrophysics Data System (ADS)

    Samir, Bhamidipati; Pereira, Mark; Paninjath, Sankaranarayanan; Jeon, Chan-Uk; Chung, Dong-Hoon; Yoon, Gi-Sung; Jung, Hong-Yul

    2015-10-01

    The blank mask defect review process involves detailed analysis of defects observed across a substrate's multiple preparation stages, such as cleaning and resist-coating. The detailed knowledge of these defects plays an important role in the eventual yield obtained by using the blank. Defect knowledge predominantly comprises of details such as the number of defects observed, and their accurate sizes. Mask usability assessment at the start of the preparation process, is crudely based on number of defects. Similarly, defect size gives an idea of eventual wafer defect printability. Furthermore, monitoring defect characteristics, specifically size and shape, aids in obtaining process related information such as cleaning or coating process efficiencies. Blank mask defect review process is largely manual in nature. However, the large number of defects, observed for latest technology nodes with reducing half-pitch sizes; and the associated amount of information, together make the process increasingly inefficient in terms of review time, accuracy and consistency. The usage of additional tools such as CDSEM may be required to further aid the review process resulting in increasing costs. Calibre® MDPAutoClassify™ provides an automated software alternative, in the form of a powerful analysis tool for fast, accurate, consistent and automatic classification of blank defects. Elaborate post-processing algorithms are applied on defect images generated by inspection machines, to extract and report significant defect information such as defect size, affecting defect printability and mask usability. The algorithm's capabilities are challenged by the variety and complexity of defects encountered, in terms of defect nature, size, shape and composition; and the optical phenomena occurring around the defect [1]. This paper mainly focuses on the results from the evaluation of Calibre® MDPAutoClassify™ product. The main objective of this evaluation is to assess the capability of

  1. Defect engineering in Multinary Semiconductors

    NASA Astrophysics Data System (ADS)

    Radautsan, S. I.

    1993-12-01

    The last two decades have shown a rapid increase both in our knowledge of the multinary compounds and their applications in engineering. The remarkable scientific leaders from different countries Prof. N.A.Goryunova, M.Rodot, A. Rabenau, E. Parthe, P. Manca, K. Matsumoto, C. Schwab, R. Tomlinson, J. Woolley, W.T. Kim, T. Irie, A. Zunger, N. Joshi, E. Sato et al. made their valuable contribution to the problems of the classification,crystal chemistry,growing processes and characterizations of multinary compounds [1-3]. Most of them were technologically difficult and as a result it was very hard to obtain the crystals with reproducible parameters. It was therefore obvious the well coordinated efforts in the field of chemistry,physics and electronics to be required. In this paper we review some of the major original results to get the defective compounds suitable for fundamental research and electronic applications. The main attention is paid to such effects as non-stoichiometry, order-disorder phase transitions as well as to non-equilibrium treatment by employing different methods of the defect engineering.

  2. Magnetoencephalography signals are influenced by skull defects.

    PubMed

    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.

  3. Effects of in-cascade defect clustering on near-term defect evolution

    SciTech Connect

    Heinisch, H.L.

    1997-08-01

    The effects of in-cascade defect clustering on the nature of the subsequent defect population are being studied using stochastic annealing simulations applied to cascades generated in molecular dynamics (MD) simulations. The results of the simulations illustrates the strong influence of the defect configuration existing in the primary damage state on subsequent defect evolution. The large differences in mobility and stability of vacancy and interstitial defects and the rapid one-dimensional diffusion of small, glissile interstitial loops produced directly in cascades have been shown to be significant factors affecting the evolution of the defect distribution. In recent work, the effects of initial cluster sizes appear to be extremely important.

  4. Defect-Engineered Metal–Organic Frameworks

    PubMed Central

    Fang, Zhenlan; Bueken, Bart; De Vos, Dirk E; Fischer, Roland A

    2015-01-01

    Defect engineering in metal–organic frameworks (MOFs) is an exciting concept for tailoring material properties, which opens up novel opportunities not only in sorption and catalysis, but also in controlling more challenging physical characteristics such as band gap as well as magnetic and electrical/conductive properties. It is challenging to structurally characterize the inherent or intentionally created defects of various types, and there have so far been few efforts to comprehensively discuss these issues. Based on selected reports spanning the last decades, this Review closes that gap by providing both a concise overview of defects in MOFs, or more broadly coordination network compounds (CNCs), including their classification and characterization, together with the (potential) applications of defective CNCs/MOFs. Moreover, we will highlight important aspects of “defect-engineering” concepts applied for CNCs, also in comparison with relevant solid materials such as zeolites or COFs. Finally, we discuss the future potential of defect-engineered CNCs. PMID:26036179

  5. Agricultural Compounds in Water and Birth Defects.

    PubMed

    Brender, Jean D; Weyer, Peter J

    2016-06-01

    Agricultural compounds have been detected in drinking water, some of which are teratogens in animal models. The most commonly detected agricultural compounds in drinking water include nitrate, atrazine, and desethylatrazine. Arsenic can also be an agricultural contaminant, although arsenic often originates from geologic sources. Nitrate has been the most studied agricultural compound in relation to prenatal exposure and birth defects. In several case-control studies published since 2000, women giving birth to babies with neural tube defects, oral clefts, and limb deficiencies were more likely than control mothers to be exposed to higher concentrations of drinking water nitrate during pregnancy. Higher concentrations of atrazine in drinking water have been associated with abdominal defects, gastroschisis, and other defects. Elevated arsenic in drinking water has also been associated with birth defects. Since these compounds often occur as mixtures, it is suggested that future research focus on the impact of mixtures, such as nitrate and atrazine, on birth defects.

  6. Primordial inhomogeneities from massive defects during inflation

    NASA Astrophysics Data System (ADS)

    Firouzjahi, Hassan; Karami, Asieh; Rostami, Tahereh

    2016-10-01

    We consider the imprints of local massive defects, such as a black hole or a massive monopole, during inflation. The massive defect breaks the background homogeneity. We consider the limit that the physical Schwarzschild radius of the defect is much smaller than the inflationary Hubble radius so a perturbative analysis is allowed. The inhomogeneities induced in scalar and gravitational wave power spectrum are calculated. We obtain the amplitudes of dipole, quadrupole and octupole anisotropies in curvature perturbation power spectrum and identify the relative configuration of the defect to CMB sphere in which large observable dipole asymmetry can be generated. We observe a curious reflection symmetry in which the configuration where the defect is inside the CMB comoving sphere has the same inhomogeneous variance as its mirror configuration where the defect is outside the CMB sphere.

  7. Little string origin of surface defects

    NASA Astrophysics Data System (ADS)

    Haouzi, Nathan; Schmid, Christian

    2017-05-01

    We derive a large class of codimension-two defects of 4d \\mathcal{N}=4 Super Yang-Mills (SYM) theory from the (2, 0) little string. The origin of the little string is type IIB theory compactified on an ADE singularity. The defects are D-branes wrapping the 2-cycles of the singularity. We use this construction to make contact with the description of SYM defects due to Gukov and Witten [1]. Furthermore, we provide a geometric perspective on the nilpotent orbit classification of codimension-two defects, and the connection to ADE-type Toda CFT. The only data needed to specify the defects is a set of weights of the algebra obeying certain constraints, which we give explicitly. We highlight the differences between the defect classification in the little string theory and its (2 , 0) CFT limit.

  8. Altering graphene line defect properties using chemistry

    NASA Astrophysics Data System (ADS)

    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.

  9. Congenital defects of the ruminant nervous system.

    PubMed

    Washburn, Kevin E; Streeter, Robert N

    2004-07-01

    Abnormalities of the nervous system are common occurrences among congenital defects and have been reported in most ruminant species. From a clinical standpoint, the signs of such defects create difficulty in arriving at an antemortem etiology through historical and physical examination alone. By first localizing clinical signs to their point of origin in the nervous system, however, a narrower differential list can be generated so that the clinician can pursue a definitive diagnosis. This article categorizes defects of the ruminant nervous system by location of salient clinical signs into dysfunction of one of more of the following regions: cerebrum, cerebellum,and spinal cord. A brief review of some of the more recognized etiologies of these defects is also provided. It is important to make every attempt to determine the cause of nervous system defects because of the impact that an inherited condition would have on a breeding program and for prevention of defects caused by infectious or toxic teratogen exposure.

  10. Reconstruction of partial laryngopharyngectomy defects.

    PubMed

    Anthony, J P; Neligan, P C; Rotstein, L E; Coleman, J

    1997-09-01

    As our contributors to this section have pointed out, there are at present two main methods of reconstructing defects of the pharynx and cervical esophagus: free jejunal transfer (FJT) and tubed radial forearm flap. The advantage of the FJT is that it is a tube, thus limiting the enteric suture lines to proximal and distal. The radial forearm flap requires not only the proximal and distal suture lines but a long longitudinal suture line to create the tube. This increase the possibility for fistula formation. The controversy surrounding this case concerns what to do with a remaining mucosal strip after a subtotal laryngectomy. Traditional reconstructive principles would dictate that normal tissue should not be sacrificed, but some would argue that the remaining mucosa should be sacrificed to allow for use of a FJT. The other alternative would be use of a radical forearm skin flap tubed to 270 degrees. At the University of Texas M. D. Anderson Cancer Center, we preferentially use the FJT for almost all defects and would probably have sacrificed the remaining mucosal strip in this particular case. We have used skin flaps to patch pharyngeal defects and prevent stricture in a number of cases. This is usually done however when the remaining pharyngeal mucosa approaches 50% or greater. Although we do not routinely use the tubed radial forearm flap because of the increased rate of fistula formation, there are some definite indications for its use. The first important indication is in patients in whom speech rehabilitation is desired or indicated. The skin flap provides a stiffer resonating chamber for the speech production and does not have the peristalsis or the mucus production associated with the jejunal flap. Another indication for use of radial forearm flap would be when there is a contraindication to celiotomy, ie, patients with hepatic cirrhosis and associated ascites or other abdominal conditions precluding abdominal exploration. In this situation, avoiding an

  11. Defect Characterization Using Two-Dimensional Arrays

    NASA Astrophysics Data System (ADS)

    Velichko, A.; Wilcox, P. D.

    2011-06-01

    2D arrays are able to `view' a given defect from a range of angles leading to the possibility of obtaining richer characterization detail than possible with 1D arrays. In this paper a quantitative comparison of 2D arrays with different element layouts is performed. A technique for extracting the scattering matrix of a defect from the raw 2D array data is also presented. The method is tested on experimental data for characterization of various volumetric defects.

  12. Processed-induced defects in EFG ribbons

    NASA Technical Reports Server (NTRS)

    Cunningham, B.; Ast, D. G.

    1982-01-01

    The defect structure of processed edge defined film-fed growth (EFG) silicon ribbons was studied using a variety of electron microscopic techniques. Comparison between the present results and previous studies on as-grown ribbons has shown that solar cell processing introduces additional defects into the ribbons. The creation of point defects during high temperature phosphorus diffusion induces dislocation climb, resulting in the formation of dislocation helices in the diffused layer.

  13. Detection of tanker defects with infrared thermography

    NASA Technical Reports Server (NTRS)

    Kantsios, A. G.

    1980-01-01

    Infrared scanning technique for finding defects in secondary barrier of liquid natural gas (LNG) tank has been successfully tested on ship under construction at Newport News Shipbuilding and Dry Dock Company. Technique determines defects with minimal expenditure of time and manpower. Tests could be repeated during life of tanker and make more complicated testing unnecessary. Tests also confirmed that tank did not have any major defects, and tank was certified.

  14. Research In Diagnosing Bearing Defects From Vibrations

    NASA Technical Reports Server (NTRS)

    Zoladz, T.; Earhart, E.; Fiorucci, T.

    1995-01-01

    Report describes research in bearing-defect signature analysis - use of vibration-signal analysis to diagnose defects in roller and ball bearings. Experiments performed on bearings in good condition and other bearings in which various parts scratched to provide known defects correlated with vibration signals. Experiments performed on highly instrumented motor-driven rotor assembly at speeds up to 10,050 r/min, using accelerometers, velocity probes, and proximity sensors mounted at various locations on assembly to measure vibrations.

  15. Detection of tanker defects with infrared thermography

    NASA Technical Reports Server (NTRS)

    Kantsios, A. G.

    1980-01-01

    Infrared scanning technique for finding defects in secondary barrier of liquid natural gas (LNG) tank has been successfully tested on ship under construction at Newport News Shipbuilding and Dry Dock Company. Technique determines defects with minimal expenditure of time and manpower. Tests could be repeated during life of tanker and make more complicated testing unnecessary. Tests also confirmed that tank did not have any major defects, and tank was certified.

  16. Non-Topological Inflation from Embedded Defects

    SciTech Connect

    Alexander, Stephon H.S

    2003-02-28

    We discuss a new mechanism of obtaining a period of cosmological inflation in the context of string theory. This mechanism is based on embedded defects which form dynamically on higher dimensional D-branes. Such defects generate topological inflation, but unlike topological inflation from stable defects, here there is a natural graceful exit from inflation: the decay of the embedded defect. We demonstrate the idea in the context of a brane-antibrane annihilation process. The graceful exit mechanism suggested here applies generically to all realizations of inflation on D-branes.

  17. Dynamic defects in photonic Floquet topological insulators

    NASA Astrophysics Data System (ADS)

    Jörg, Christina; Letscher, Fabian; Fleischhauer, Michael; von Freymann, Georg

    2017-08-01

    Edge modes in topological insulators are known to be robust against defects. We investigate if this also holds true when the defect is not static, but varies in time. We study the influence of defects with time-dependent coupling on the robustness of the transport along the edge in a Floquet system of helically curved waveguides. Waveguide arrays are fabricated via direct laser writing in a negative tone photoresist. We find that single dynamic defects do not destroy the chiral edge current, even when the temporal modulation is strong. Quantitative numerical simulation of the intensity in the bulk and edge waveguides confirms our observation.

  18. Multimode model based defect characterization in composites

    NASA Astrophysics Data System (ADS)

    Roberts, R.; Holland, S.; Gregory, E.

    2016-02-01

    A newly-initiated research program for model-based defect characterization in CFRP composites is summarized. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing delamination and porosity. Forward predictions of measurement response are presented, as well as examples of model-based inversion of measured data for the estimation of defect parameters.

  19. Surface defects and instanton-vortex interaction

    NASA Astrophysics Data System (ADS)

    Gorsky, A.; Le Floch, B.; Milekhin, A.; Sopenko, N.

    2017-07-01

    We propose a simple formula for the 4d-2d partition function of half-BPS surface defects in d = 4, N = 2 gauge theories: Z4d-2d =4d. Our results are applicable for any surface defect obtained by gauging a 2d flavor symmetry using a 4d gauge group. For defects obtained via the Higgsing procedure, our formula reproduces the recent calculation by Pan and Peelaers. For Gukov-Witten defects our results reproduce the orbifold calculation by Kanno and Tachikawa. We emphasize the role of ;negative vortices; which are realized as negative D0 branes.

  20. Augmentation of craniofacial defects using alloplastic material.

    PubMed

    Osunde, O D; Adebola, R A; Ver-or, N; Amole, I O; Akhiwu, B I; Jinjiri, N; Ladeinde, A; Ajike, S O; Efunkoya, A

    2013-09-01

    Alloplastic materials are increasingly being used in augmentation of craniofacial defects because of its ready availability, good aesthetic outcome and absence of donor site morbidity. This paper highlights experience in the use of heat-cured acrylic in augmentation cranioplasty. The management of three patients with anterior skull defect who presented at the Dental and Maxillofacial Surgery Clinic of the Aminu Kano Teaching Hospital over a five-year period is presented. There was good aesthetic outcome in all the patients and no complications were recorded. Augmentation of craniofacial defects using customized prefabricated heat-cured acrylic provides patients with a durable, stable and structural repair of craniofacial defects with good aesthetic outcome.

  1. Reconstruction of Small Soft Tissue Nasal Defects

    PubMed Central

    Wolfswinkel, Erik M.; Weathers, William M.; Cheng, David; Thornton, James F.

    2013-01-01

    Nasal defect repair has been one of the more challenging areas of reconstructive surgery due to the lack of uniform nasal skin thickness and complex contours. Currently, algorithms for medium to large nasal soft tissue defects have been well defined by various authors. Small defects, arbitrarily defined as 1 cm or less, still present significant challenges. In this article, the authors examine the options available to repair small soft tissue nasal defects and the appropriate situations in which each method is best suited. PMID:24872751

  2. [Integrated approach to nasal defects reconstruction].

    PubMed

    Verbo, E V; Gorkush, K N

    2016-01-01

    The aim of the study was to define and solve main problems in nasal defects reconstruction procedures planning. Fifty-two patients with nasal defects treated in Central Research Institute of Dentistry and Maxillofacial Surgery in 2010-2015 were included in the study. In 28 cases the defects were reconstructed by means of paramedial forehead flap. The authors highlight typical procedure pitfalls mainly associated with the planning stage. The study results prove paramedical forehead flap to be the most useful tool for subtotal and total nasal defects reconstruction but meticulous procedure planning is a must for success.

  3. Defect interactions within a group of subcascades

    SciTech Connect

    Heinisch, H.L.

    1996-10-01

    The evolution of the defect distributions within high energy cascades that contain multiple subcascades is studied as a function of temperature for cascades in copper. Low energy cascades generated with molecular dynamics are placed in close proximity to simulate the arrangement of subcascades within a high energy event, then the ALSOME code follows the evolution of the cascade damage during short term annealing. The intersubcascade defect interactions during the annealing stage are found to be minimal. However, no conclusions regarding effects of subcascades on defect production should be drawn until intersubcascade defect interactions during the quenching stage are examined.

  4. Defect reduction through Lean methodology

    NASA Astrophysics Data System (ADS)

    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.

  5. Electricity generation from defective tomatoes.

    PubMed

    Shrestha, Namita; Fogg, Alex; Wilder, Joseph; Franco, Daniel; Komisar, Simeon; Gadhamshetty, Venkataramana

    2016-12-01

    The United States faces a significant burden in treating 0.61billionkg of defective tomatoes (culls) every year. We present a proof-of-concept for generating electricity from culled tomatoes in microbial-electrochemical systems (MESs). This study delineates impedance behavior of the culled tomatoes in MESs and compares its impedance spectra with that of soluble substrates (dextrose, acetate, and wastewater). A series of AC and DC diagnostic tests have revealed the superior performance of the culled tomatoes compared to the pure substrates. Cyclic voltammetry results have indicated the active role of indigenous, diffusible redox-active pigments in the culled tomatoes on overall electricity production. Electrochemical impedance spectroscopy results have elucidated the role of peel and seed on the oxidation behavior of the culled tomatoes.

  6. Topological conformal defects with tensor networks

    NASA Astrophysics Data System (ADS)

    Hauru, Markus; Evenbly, Glen; Ho, Wen Wei; Gaiotto, Davide; Vidal, Guifre

    2016-09-01

    The critical two-dimensional classical Ising model on the square lattice has two topological conformal defects: the Z2 symmetry defect Dɛ and the Kramers-Wannier duality defect Dσ. These two defects implement antiperiodic boundary conditions and a more exotic form of twisted boundary conditions, respectively. On the torus, the partition function ZD of the critical Ising model in the presence of a topological conformal defect D is expressed in terms of the scaling dimensions Δα and conformal spins sα of a distinct set of primary fields (and their descendants, or conformal towers) of the Ising conformal field theory. This characteristic conformal data {Δα,sα}D can be extracted from the eigenvalue spectrum of a transfer matrix MD for the partition function ZD. In this paper, we investigate the use of tensor network techniques to both represent and coarse grain the partition functions ZDɛand ZD σ of the critical Ising model with either a symmetry defect Dɛ or a duality defect Dσ. We also explain how to coarse grain the corresponding transfer matrices MDɛand MD σ, from which we can extract accurate numerical estimates of {Δα,sα}Dɛ and {Δα,sα}Dσ. Two key ingredients of our approach are (i) coarse graining of the defect D , which applies to any (i.e., not just topological) conformal defect and yields a set of associated scaling dimensions Δα, and (ii) construction and coarse graining of a generalized translation operator using a local unitary transformation that moves the defect, which only exist for topological conformal defects and yields the corresponding conformal spins sα.

  7. Modeling the relationships among internal defect features and external Appalachian hardwood log defect indicators

    Treesearch

    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...

  8. Predicting internal white oak (Quercus alba) log defect features using surface defect indicator measurements

    Treesearch

    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...

  9. 9 CFR 91.30 - Defective fittings.

    Code of Federal Regulations, 2010 CFR

    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...

  10. Localization of defects using checkerboard test structures

    NASA Astrophysics Data System (ADS)

    Schellenberg, Sven-Olaf

    2001-04-01

    Defects in semiconductor industry become more important by shrinking structures and increasing complexity of process. Therefore the size of a killer defect becomes smaller and it is not easy to find them with optical inspection tools. In addition Inspection tools are not able to say something about electrical effects from defects which are found. With Checkerboard Test Structures it is possible to locate electrical defects. In fact these special test structures will be tested at the end of the process, like an usual function test. A special developed algorithm allows low quantity of pads. This gives a high spatial resolution and on the other hand we have good ratio between active and passive area. A reduction of a statistical failure could be reached, because it is not necessary to calculate the defect density from a small region. In particular special defect distribution like cluster can be considered. With this structures different layers can be examined for disconnections and short-circuits. Therefore it is possible to locate defects in one layer or between two layers. So the defect density for the sensitive dielectrica between two layers, like any kind of oxide can be calculated. The karree test structures can be used very good as an inline-defectmonitoring, because there is no difference from the original technology of proces. There are also no differences in time for processing and for testing, so Karreeteststructures is an optimal representation for your process.

  11. 7 CFR 51.2720 - Minor defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Shelled Runner Type Peanuts Definitions § 51.2720 Minor defects. Minor defects means that the... which is dark brown, dark gray, dark blue or black and covers more than one-fourth of the surface; (b) Flesh discoloration which is darker than a light yellow color or consists of more than a slight...

  12. 7 CFR 51.2762 - Minor defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Shelled Virginia Type Peanuts Definitions § 51.2762 Minor defects. Minor defects means that... discoloration which is dark brown, dark gray, dark blue or black and covers more than one-fourth of the surface; (b) Flesh discoloration which is darker than a light yellow color or consists of more than a...

  13. Folic acid and birth defect prevention

    MedlinePlus

    ... Women who have had a baby with a neural tube defect may need a higher dose of folic acid. If you have had a baby with a neural tube defect, you should take 400 micrograms of folic acid every day, even when you are not planning ...

  14. Sizing Dye-Penetrant Indications Of Defects

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1988-01-01

    Sizes of cracks and holes viewed through borescope measured. Reference chart makes it possible to estimate sizes of borescope-observed defects on inner walls of tubes or otherwise hidden. Used both for round defects like pits or pores and for elongated ones like cracks.

  15. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7002 Equipment defects. Equipment defects affecting safety shall be corrected...

  16. 30 CFR 57.7002 - Equipment defects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7002 Equipment defects. Equipment defects affecting...

  17. 7 CFR 52.780 - Defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Cherries 1 Factors of Quality § 52.780 Defects. (a) General. The factor of defects refers to the degree of freedom from harmless extraneous material, mutilated cherries, and cherries blemished by scab, hail injury, discoloration, scar tissue, or by other means. (1) Cherry means a whole cherry, whether or not pitted,...

  18. First principles calculations for defects in U

    SciTech Connect

    B. Beeler; B. Good; S. Rashkeev; C. Deo; M. Baskes; M. Okuniewski

    2010-12-01

    Uranium (U) exhibits a high temperature body-centered cubic (bcc) allotrope that is often stabilized by alloying with transition metals such as Zr, Mo, and Nb for technological applications. One such application involves U–Zr as nuclear fuel, where radiation damage and diffusion (processes heavily dependent on point defects) are of vital importance. Several systems of U are examined within a density functional theory framework utilizing projector augmented wave pseudopotentials. Two separate generalized gradient approximations of the exchange-correlation are used to calculate defect properties and are compared. The bulk modulus, the lattice constant, and the Birch–Murnaghan equation of state for the defect free bcc uranium allotrope are calculated. Defect parameters calculated include energies of formation of vacancies in the a and ? allotropes, as well as self-interstitials, Zr interstitials, and Zr substitutional defects for the ? allotrope. The results for vacancies agree very well with experimental and previous computational studies. The most probable self-interstitial site in ?-U is the 110 dumbbell, and the most probable defect location for dilute Zr in ?-U is the substitutional site. This is the first detailed study of self-defects in the bcc allotrope of U and also the first comprehensive study of dilute Zr defects in ?-U.

  19. Effects of log defects on lumber recovery.

    Treesearch

    James M. Cahill; Vincent S. Cegelka

    1989-01-01

    The impact of log defects on lumber recovery and the accuracy of cubic log scale deductions were evaluated from log scale and product recovery data for more than 3,000 logs. Lumber tally loss was estimated by comparing the lumber yield of sound logs to that of logs containing defects. The data were collected at several product recovery studies; they represent most of...

  20. Impurity Role In Mechanically Induced Defects

    SciTech Connect

    Howell, R.H.; Asoka-Kumar, P.; Hartley, J.; Sterne, P.

    2000-02-25

    An improved understanding of dislocation dynamics and interactions is an outstanding problem in the multi scale modeling of materials properties, and is the current focus of major theoretical efforts world wide. We have developed experimental and theoretical tools that will enable us to measure and calculate quantities defined by the defect structure. Unique to the measurements is a new spectroscopy that determines the detailed elemental composition at the defect site. The measurements are based on positron annihilation spectroscopy performed with a 3 MeV positron beam [1]. Positron annihilation spectroscopy is highly sensitive to dislocations and associated defects and can provide unique elements of the defect size and structure. Performing this spectroscopy with a highly penetrating positron beam enables flexibility in sample handling. Experiments on fatigued and stressed samples have been done and in situ measurement capabilities have been developed. We have recently performed significant upgrades to the accelerator operation and novel new experiments have been performed [2-4] To relate the spectrographic results and the detailed structure of a defect requires detailed calculations. Measurements are coupled with calculated results based on a description of positions of atoms at the defect. This gives an atomistic view of dislocations and associated defects including impurity interactions. Our ability to probe impurity interactions is a unique contribution to defect understanding not easily addressed by other atomistic spectroscopies.

  1. Simple intrinsic defects in InAs :

    SciTech Connect

    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.

  2. Quantum defect analysis of HD photoionization

    SciTech Connect

    Du, N.Y.; Greene, C.H.

    1986-11-15

    A multichannel quantum defect calculation is shown to reproduce most observed features in several portions of the HD photoabsorption spectrum. The rovibrational frame transformation theory of Atabek, Dill, and Jungen is reformulated in terms of a quantum defect matrix. The calculation accounts for spectral regions far from dissociation thresholds despite its neglect of g--u mixing.

  3. Defect complexes in semiconductors and insulators

    NASA Astrophysics Data System (ADS)

    Raebiger, Hannes

    2010-03-01

    The interaction of isolated defects and impurities (concentration upto ˜10^18 cm-3) is usually rationalized as that of point charges in a dielectric medium, but as defect concentrations are in the order of atomic percent (˜10^21 cm-3), the statistical probability for two or more defects to sit on neighboring sites, forming a cluster or complex, becomes significant [1]. The formation of such clusters changes the local chemical environment, which in turn affects the electronic (and optical and magnetic) properties of the constituent defects non-trivially. To understand these changes, I study a variety of bound defect complexes in wide-gap semiconductors, composed of both deep and shallow defects, focusing on the shifting of the gap levels caused by defect--defect chemical interactions. First the electronic structure is calculated from first principles calculations, and then I will outline a simple theory that describes the level shifts due to cluster formation qualitatively and semi-quantitatively in terms local atomic shielding constants derived from local charge self-regulation [2].[4pt] [1] R. Behringer, J. Chem. Phys. 29, 537 (1958).[0pt] [2] H. Raebiger, S. Lany, and A. Zunger, Nature 453, 763 (2008).

  4. Biomaterials for reconstruction of cranial defects

    NASA Astrophysics Data System (ADS)

    Song, Tao; Qiu, Zhi-Ye; Cui, Fu-Zhai

    2015-12-01

    Reconstruction of cranial defect is commonly performed in neurosurgical operations. Many materials have been employed for repairing cranial defects. In this paper, materials used for cranioplasty, including autografts, allografts, and synthetic biomaterials are comprehensively reviewed. This paper also gives future perspective of the materials and development trend of manufacturing process for cranioplasty implants.

  5. Unsound defect volume in hardwood pallet cants

    Treesearch

    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...

  6. Orbital dystopia due to orbital roof defect.

    PubMed

    Rha, Eun Young; Joo, Hong Sil; Byeon, Jun Hee

    2013-01-01

    We performed a retrospective review of patients who presented with delayed dystopia as a consequence of an orbital roof defect due to fractures and nontraumatic causes to search for a correlation between orbital roof defect size and surgical indications for the treatment thereof. Retrospective analyses were performed in 7 patients, all of whom presented with delayed dystopia due to orbital roof defects, between January 2001 and June 2011. The causes of orbital roof defects were displaced orbital roof fractures (5 cases), tumor (1 case), and congenital sphenoid dysplasia (1 case). All 7 patients had initially been treated conservatively and later presented with significant dystopia. The sizes of the defects were calculated on computed tomographic scans. Among the 7 patients, aspiration of cerebrospinal fluid, which caused ocular symptoms, in 1 patient with minimal displaced orbital roof and reconstruction with calvarial bone, titanium micromesh, or Medpor in 6 other patients were performed. The minimal size of the orbital roof in patients who underwent orbital roof reconstruction was 1.2 cm (defect height) x 1.0 cm (defect length), 0.94 cm(2). For all patients with orbital dystopia, displacement of the globe was corrected without any complications, regardless of whether the patient was evaluated grossly or by radiology. In this retrospective study, continuous monitoring of clinical signs and active surgical management should be considered for cases in which an orbital roof defect is detected, even if no definite symptoms are noted, to prevent delayed sequelae.

  7. Point Defect Structure of Cr203

    DTIC Science & Technology

    1987-10-01

    11 2.2.5 Effects of Impurities on Defect Equilibria .................. 14 2.3 Electrical Conductivity...both cationic vacancies and interstitials ........................................ 15 2.4 The impurity effect on the defect structure of a P-type...25 2.7 Seebeck effect of a semiconductor ................................................ 27 2.8 Oxygen partial pressure

  8. 7 CFR 52.780 - Defects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... free from defects may be given a score of 27 to 30 points. “Practically free from defects” means that... in Table IV. (c) (B) classification. Canned red tart pitted cherries that are reasonably free from defects may be given a score of 24 to 26 points. Canned red tart pitted cherries that fall into this...

  9. 7 CFR 52.780 - Defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Defects. (a) General. The factor of defects refers to the degree of freedom from harmless extraneous... given a score of 24 to 26 points. Canned red tart pitted cherries that fall into this classification may... red tart pitted cherries that fall into this classification shall not be graded above U.S. Grade...

  10. Line defects and (framed) BPS quivers

    NASA Astrophysics Data System (ADS)

    Cirafici, Michele

    2013-11-01

    The BPS spectrum of certain = 2 supersymmetric field theories can be determined algebraically by studying the representation theory of BPS quivers. We introduce methods based on BPS quivers to study line defects. The presence of a line defect opens up a new BPS sector: framed BPS states can be bound to the defect. The defect can be geometrically described in terms of laminations on a curve. To a lamination we associate certain elements of the Leavitt path algebra of the BPS quiver and use them to compute the framed BPS spectrum. We also provide an alternative characterization of line defects by introducing framed BPS quivers. Using the theory of (quantum) cluster algebras, we derive an algorithm to compute the framed BPS spectra of new defects from known ones. Line defects are generated from a framed BPS quiver by applying certain sequences of mutation operations. Framed BPS quivers also behave nicely under a set of "cut and join" rules, which can be used to study how = 2 systems with defects couple to produce more complicated ones. We illustrate our formalism with several examples.

  11. Defective Artemis causes mild telomere dysfunction.

    PubMed

    Yasaei, Hemad; Slijepcevic, Predrag

    2010-05-26

    Repair of DNA double strand breaks by non-homologous end joining (NHEJ) requires several proteins including Ku, DNA-PKcs, Artemis, XRCC4, Ligase IV and XLF. Two of these proteins, namely Ku and DNA-PKcs, are also involved in maintenance of telomeres, chromosome end-structures. In contrast, cells defective in Ligase IV and XRCC4 do not show changes in telomere length or function suggesting that these proteins are not involved in telomere maintenance. Since a mouse study indicated that defective Artemis may cause telomere dysfunction we investigated the effects of defective Artemis on telomere maintenance in human cells. We observed significantly elevated frequencies of telomeric fusions in two primary fibroblast cell lines established from Artemis defective patients relative to the control cell line. The frequencies of telomeric fusions increased after exposure of Artemis defective cells to ionizing radiation. Furthermore, we observed increased incidence of DNA damage at telomeres in Artemis defective cells that underwent more than 32 population doublings using the TIF (Telomere dysfunction Induced Foci) assay. We have also inhibited the expression levels of DNA-PKcs in Artemis defective cell lines by either using synthetic inhibitor (IC86621) or RNAi and observed their greater sensitivity to telomere dysfunction relative to control cells. These results suggest that defective Artemis causes a mild telomere dysfunction phenotype in human cell lines.

  12. Defective Artemis causes mild telomere dysfunction

    PubMed Central

    2010-01-01

    Background Repair of DNA double strand breaks by non-homologous end joining (NHEJ) requires several proteins including Ku, DNA-PKcs, Artemis, XRCC4, Ligase IV and XLF. Two of these proteins, namely Ku and DNA-PKcs, are also involved in maintenance of telomeres, chromosome end-structures. In contrast, cells defective in Ligase IV and XRCC4 do not show changes in telomere length or function suggesting that these proteins are not involved in telomere maintenance. Since a mouse study indicated that defective Artemis may cause telomere dysfunction we investigated the effects of defective Artemis on telomere maintenance in human cells. Results We observed significantly elevated frequencies of telomeric fusions in two primary fibroblast cell lines established from Artemis defective patients relative to the control cell line. The frequencies of telomeric fusions increased after exposure of Artemis defective cells to ionizing radiation. Furthermore, we observed increased incidence of DNA damage at telomeres in Artemis defective cells that underwent more than 32 population doublings using the TIF (Telomere dysfunction Induced Foci) assay. We have also inhibited the expression levels of DNA-PKcs in Artemis defective cell lines by either using synthetic inhibitor (IC86621) or RNAi and observed their greater sensitivity to telomere dysfunction relative to control cells. Conclusion These results suggest that defective Artemis causes a mild telomere dysfunction phenotype in human cell lines. PMID:20678254

  13. Defect chemistry of silver selenogallate

    NASA Astrophysics Data System (ADS)

    Whittaker, Matthew Thomas

    2007-12-01

    The source of 9.3 mum absorption in silver selenogallate, AgGaSe 2 was investigated. Infrared spectrophotometric analysis of two as-received, reportedly stoichiometric, single crystals found 9.3 mum absorption coefficients of 0.109 and 0.101 cm-1. Infrared transmission of the slabs was otherwise uniform at 0.007 cm-1 through the range 6--12 gym. X-ray fluorescence measurements did not indicate an extrinsic impurity was responsible for the absorption. Intrinsic defect reactions were investigated and a Brouwer diagram was constructed to determine probable native defects. Analysis of the Brouwer diagram led to the hypothesis that the 9.3 mum absorption was caused by a native selenium vacancy. A series of heat treatments were conducted at 790°C with selenium partial pressures of 0.026, 0.040, 0.057, 0.138, and 0.243 atmospheres. Heat treatments below 0.060 atmospheres selenium partial pressure resulted in null or increased absorption at 9.3 mum up to 0.128 cm-1. Heat treatment at 0.243 atmospheres selenium partial pressure resulted in a decrease of the 9.3 mum absorption coefficient of 63% to 0.037 cm-1. A linear least-squares regression of the 9.3 mum absorption coefficient versus selenium partial pressure during heat treatment resulted in an equation for the absorption coefficient. alpha9.3mum = -0.4048 (PSe) atm -1cm-1 + 0.1322cm -1. The highest electrical resistivity of AgGaSe2 was measured at 7.6 x 1011 Ocm for a crystal with a 9.3 mum absorption coefficient of 0.037 cm-1. A linear least-squares regression of the 9.3 mum absorption coefficient versus bulk electrical resistivity resulted in an equation for the resistivity: rho = -7 x 1012 alpha9.3mumO cm2 + 1 x 1012 O cm. Thus, the electrical resistivity increases as the stoichiometric composition is approached and may be used as a measure of stoichiometry. The deleterious 9.3 mum absorption has not been entirely eliminated; however, the reduction in the 9.3 mum absorption coefficient from greater than 0.100 cm-1

  14. Defective Reduction in Frozen Pie Manufacturing Process

    NASA Astrophysics Data System (ADS)

    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%.

  15. Characterizing solute-lean defects in superalloys

    NASA Astrophysics Data System (ADS)

    Samuelsson, E.; Domingue, J. A.; Maurer, G. E.

    1990-08-01

    Solute-lean defects, commonly called white spots, are frequently found in superalloys. These defects limit the service life of components made from superalloys, and alloy producers have devoted intense study to their characterization and elimination. Recent work shows that solute lean defects can be classified as "discrete," "diffuse" and "mini," and can be further classified into "clean" and "dirty" white spots. More than one formation mechanism for white spots is exemplified by the chemical and morphological differences between discrete, diffuse and mini white spots. White spot detection depends on the thermomechanically developed precipitation of hardening phases, coupled with specific etches that preferentially react to microstructure differences. The white spot defect is indigenous to the vacuum arc remelting process, but defect formation can be minimized by careful process control.

  16. Eggshell defects detection based on color processing

    NASA Astrophysics Data System (ADS)

    Garcia-Alegre, Maria C.; Ribeiro, Angela; Guinea, Domingo; Cristobal, Gabriel

    2000-03-01

    The automatic classification of defective eggs constitutes a fundamental issue at the poultry industry for both economical and sanitary reasons. The early separation of eggs with spots and cracks is a relevant task as the stains can leak while progressing on the conveyor-belts, degrading all the mechanical parts. Present work is focused on the implementation of an artificial vision system for detecting in real time defective eggs at the poultry farm. First step of the algorithmic process is devoted to the detection of the egg shape to fix the region of interest. A color processing is then performed only on the eggshell to obtain an image segmentation that allows the discrimination of defective eggs from clean ones in critic time. The results are presented to demonstrate the validity of the proposed visual process on a wide sample of both defective and non-defective eggs.

  17. Topological defect dynamics in operando battery nanoparticles

    NASA Astrophysics Data System (ADS)

    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.

  18. Native point defects in GaSb

    SciTech Connect

    Kujala, J.; Segercrantz, N.; Tuomisto, F.; Slotte, J.

    2014-10-14

    We have applied positron annihilation spectroscopy to study native point defects in Te-doped n-type and nominally undoped p-type GaSb single crystals. The results show that the dominant vacancy defect trapping positrons in bulk GaSb is the gallium monovacancy. The temperature dependence of the average positron lifetime in both p- and n-type GaSb indicates that negative ion type defects with no associated open volume compete with the Ga vacancies. Based on comparison with theoretical predictions, these negative ions are identified as Ga antisites. The concentrations of these negatively charged defects exceed the Ga vacancy concentrations nearly by an order of magnitude. We conclude that the Ga antisite is the native defect responsible for p-type conductivity in GaSb single crystals.

  19. Wavenumber and Defect Distributions in Undulation Chaos

    NASA Astrophysics Data System (ADS)

    Daniels, Karen E.; Bodenschatz, Eberhard

    2000-11-01

    We report experimental results on thermally driven convection in a large aspect ratio inclined layer with a fluid of Prandtl number σ ≈ 1. Very close to the onset of convection for inclination angles between 20 and 70 degrees, we find the defect turbulent state of undulation chaos (Daniels, Plapp, and Bodenschatz. Phys. Rev. Lett. 84:5320). We characterize this state by determining the defect locations and the wavenumber distribution. A snapshot of the pattern, as well as its wavenumber distribution, can be well-reconstructed from a perfect underlying undulation pattern and the phase field given by the point defects. The defect density distribution shows a crossover from a Poisson to a squared Poisson distribution. By measuring the creation, annihilation, inflow, and outflow rates of defects we can quantitatively explain this behavior. This work is supported by the National Science Foundation DMR-0072077.

  20. Woodgrain defect on tinned steel Flandres foil

    SciTech Connect

    Sarkis, A.M.; Robin, A. Souza, V.A.; Suzuki, P.A.

    2011-06-15

    Tin electrocoated steel strip, also referred to as Flandres foil, is largely used for manufacturing food containers. Tinplates must have good corrosion resistance, workability, weldability, as well as a bright appearance. The woodgrain defect, a not yet fully understood defect that occurs on tinplates and accounts for their high scrap rate, consists of alternate bands of bright/dull reflectivity and resembles longitudinally cut wood. Observations of the woodgrain defect by scanning electron microscopy showed that the molten tin spreads irregularly during both the melting and solidification stages. X-ray diffraction analyses showed that the metallic tin tended to crystallize in the (200) direction for coupons with and without the woodgrain defect. Nevertheless, the preferential orientation degree decreased for coupons with the woodgrain defect. The rocking curves, also known as omega-scan, showed that the tin grains were uniformly aligned parallel to the strip surface for coupons with no defects, whereas for tinplates with woodgrain, the tin grains were not uniformly oriented, probably due to the misalignment of the grains in relation to the surface. - Graphical abstract: The woodgrain defect occurs on Flandres tinplates and consists in the formation of alternate bands of different reflectivity (bright/dull), which looks like longitudinally cut wood. X-ray diffractometry showed that the typical bright surface of tinplate is associated to the uniform distribution of aligned (200) Sn grains, whereas in tinplate with the woodgrain defect, the Sn grains were not uniformly oriented, due to the misalignment of the (200) Sn planes relative to the surface. Research highlights: {yields} The bright surface of tinplate is associated to the uniform distribution of aligned (200) Sn grains. {yields} The woodgrain defect on tinplate consists in alternate bands of bright/dull appearance. {yields} In tinplate with the woodgrain defect, the Sn grains were not uniformly oriented, due

  1. Point defects at the ice (0001) surface.

    PubMed

    Watkins, Matthew; VandeVondele, Joost; Slater, Ben

    2010-07-13

    Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk crystal is smaller than its bulk formation energy. Absolute and relative segregation energies are sensitive to the surface structure of ice, especially the spatial distribution of protons associated with dangling hydrogen bonds. It is found that the basal plane surface of hexagonal ice increases the bulk concentration of Bjerrum defects, strongly favoring D-defects over L-defects. Dangling protons associated with undercoordinated water molecules are preferentially injected into the crystal bulk as Bjerrum D-defects, leading to a surface dipole that attracts hydronium ions. Aside from the disparity in segregation energies for the Bjerrum defects, we find the interactions between defect species to be very finely balanced; surface segregation energies for hydronium and hydroxide species and trapping energies of these ionic species with Bjerrum defects are equal within the accuracy of our calculations. The mobility of the ionic hydronium and hydroxide species is greatly reduced at the surface in comparison to the bulk due to surface sites with high trapping affinities. We suggest that, in pure ice samples, the surface of ice will have an acidic character due to the presence of hydronium ions. This may be important in understanding the reactivity of ice particulates in the upper atmosphere and at the boundary layer.

  2. The role of point defects and defect complexes in silicon device processing. Summary report and papers

    SciTech Connect

    Sopori, B.; Tan, T.Y.

    1994-08-01

    This report is the summary of the third workshop on the role of point defects and defect complexes in silicon device processing. The workshop was organized: (1) to discuss recent progress in the material quality produced by photovoltaic Si manufacturers, (2) to foster the understanding of point defect issues in Si device processing, (3) to review the effects of inhomogeneities on large- area solar cell performance, (4) to discuss how to improve Si solar cell processing, and (5) to develop a new understanding of gettering, defect passivation, and defect annihilation. Separate abstract were prepared for the individual papers, for the database.

  3. Interleukin-6 Stimulates Defective Angiogenesis.

    PubMed

    Gopinathan, Ganga; Milagre, Carla; Pearce, Oliver M T; Reynolds, Louise E; Hodivala-Dilke, Kairbaan; Leinster, David A; Zhong, Haihong; Hollingsworth, Robert E; Thompson, Richard; Whiteford, James R; Balkwill, Frances

    2015-08-01

    The cytokine IL6 has a number of tumor-promoting activities in human and experimental cancers, but its potential as an angiogenic agent has not been fully investigated. Here, we show that IL6 can directly induce vessel sprouting in the ex vivo aortic ring model, as well as endothelial cell proliferation and migration, with similar potency to VEGF. However, IL6-stimulated aortic ring vessel sprouts had defective pericyte coverage compared with VEGF-stimulated vessels. The mechanism of IL6 action on pericytes involved stimulation of the Notch ligand Jagged1 as well as angiopoietin2 (Ang2). When peritoneal xenografts of ovarian cancer were treated with an anti-IL6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies, there was an association between levels of IL6 mRNA, Jagged1, and Ang2. Our findings have implications for the use of cancer therapies that target VEGF or IL6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease, and stroke.

  4. Epidemiology of neural tube defects.

    PubMed

    Frey, Lauren; Hauser, W Allen

    2003-01-01

    Neural tube defects (NTDs)-malformations secondary to abnormal neural tube closure between the third and fourth weeks of gestational age-have a complex and imperfectly understood etiology in which both genetic and environmental factors appear to be involved. A number of specific chromosomal or single-gene disorders, presumably not affected by environmental influences, are associated with the development of NTDs, but such syndromal cases account for a small proportion of NTDs in live-born infants. Analysis of recurrence patterns within families and of twin-concordance data provides evidence of a genetic influence in nonsyndromal cases, but factors such as socioeconomic status and geographic area (independent of race or ethnicity) are also associated with variations in the incidence of NTDs. The prevalence at birth of both anencephaly and spina bifida has decreased, but the advent of antenatal diagnosis and elective termination of affected pregnancies has undermined the reliability of birth prevalence rate as an estimate of incidence. Some occupational and other exposures, including maternal use of antiepileptic drugs (AEDs), are associated with increased risk for NTDs. Among women who have had an NTD-affected pregnancy, recurrence risk is markedly higher than the risk for a first NTD-affected pregnancy in the general population. There is strong evidence, overall, for a protective effect of adequate folate consumption. In some high-risk groups, however, such as women taking AEDs, folate supplementation has not been proven to reduce NTD risk.

  5. The defective RNAs of Closteroviridae

    PubMed Central

    Bar-Joseph, Moshe; Mawassi, Munir

    2013-01-01

    The family Closteroviridae consists of two genera, Closterovirus and Ampelovirus with monopartite genomes transmitted respectively by aphids and mealybugs and the Crinivirus with bipartite genomes transmitted by whiteflies. The Closteroviridae consists of more than 30 virus species, which differ considerably in their phytopathological significance. Some, like beet yellows virus and citrus tristeza virus (CTV) were associated for many decades with their respective hosts, sugar beets and citrus. Others, like the grapevine leafroll-associated ampeloviruses 1, and 3 were also associated with their grapevine hosts for long periods; however, difficulties in virus isolation hampered their molecular characterization. The majority of the recently identified Closteroviridae were probably associated with their vegetative propagated host plants for long periods and only detected through the considerable advances in dsRNA isolation and sequencing of PCR amplified replicons. Molecular characterization of CTV and several other Closteroviridae revealed that, in addition to genomic and subgenomic RNAs, infected plants contain several different subviral defective RNAs (dRNAs). The roles and biological functions of dRNAs associated with Closteroviridae remain terra incognita. PMID:23734149

  6. Reconstruction of posterior trunk defects.

    PubMed

    Ramasastry, S S; Schlechter, B; Cohen, M

    1995-01-01

    A high rate of success can be expected in the management of posterior trunk defects with muscle flaps. The surgeon has to adhere closely to the basic reconstructive principles of adequate debridement of all necrotic or devitalized tissues; management of infection with local wound care and appropriate antibiotic therapy; and coverage with well-vascularized tissue to obliterate any residual dead space and to cover bone grafts, orthopedic hardware, and vital structures such as the dura and spinal cord. Flap selection is also of paramount importance for success, and only muscles with appropriate arc of rotation, vascularity (vascular pedicles outside the field of radiation injury, or intact vascularity following previous procedures) and bulk should be used. Adequate flap mobilization to obtain a tension-free closure and judicious use of drains and perioperative antibiotic agents are essential. Occasionally, microvascular free-tissue transfer may be necessary if local flaps are unavailable. The complications of flap reconstruction include partial flap loss, persistent dead space for lack of adequate muscle bulk, and persistent infection. Debridement and re-advancement of the flap is adequate in most cases. If there is significant or total flap loss, however, a second flap reconstruction is often necessary to obliterate the dead space and protect vital structures.

  7. DIVAS: an integrated networked system for mask defect dispositioning and defect management

    NASA Astrophysics Data System (ADS)

    Munir, Saghir; Bald, Dan; Tolani, Vikram; Ghadiali, Firoz

    2003-06-01

    Mask quality is a prime concern to the Intel Mask Operation (IMO) and the Intel wafer fabrication customers. Extreme concern is taken to inspect and repair all defects before shipment. Given that the classification and repair of defects detected by inspection systems is labor intensive, the procedure is prone to human error. Futhermore, since operators manually disposition hundreds of defects each day, it is virtually impossible to eliminate all misclassifications. Due to diffraction effects, not all defects resolve on a wafer. Hence, a defect that an operator may classify as 'real' may indeed be 'lithographically insignifincant'. Conversely an operator may miss a defect that prints, causing a serious reduction in product yield. The DIVAS (Defect, Inspection, Viewing, Archiving and Simulation) system has been described previously and was developed to address these manual classification issues. This paper outlines the fully automated system deployed in a production environment.

  8. Studying post-etching silicon crystal defects on 300mm wafer by automatic defect review AFM

    NASA Astrophysics Data System (ADS)

    Zandiatashbar, Ardavan; Taylor, Patrick A.; Kim, Byong; Yoo, Young-kook; Lee, Keibock; Jo, Ahjin; Lee, Ju Suk; Cho, Sang-Joon; Park, Sang-il

    2016-03-01

    Single crystal silicon wafers are the fundamental elements of semiconductor manufacturing industry. The wafers produced by Czochralski (CZ) process are very high quality single crystalline materials with known defects that are formed during the crystal growth or modified by further processing. While defects can be unfavorable for yield for some manufactured electrical devices, a group of defects like oxide precipitates can have both positive and negative impacts on the final device. The spatial distribution of these defects may be found by scattering techniques. However, due to limitations of scattering (i.e. light wavelength), many crystal defects are either poorly classified or not detected. Therefore a high throughput and accurate characterization of their shape and dimension is essential for reviewing the defects and proper classification. While scanning electron microscopy (SEM) can provide high resolution twodimensional images, atomic force microscopy (AFM) is essential for obtaining three-dimensional information of the defects of interest (DOI) as it is known to provide the highest vertical resolution among all techniques [1]. However AFM's low throughput, limited tip life, and laborious efforts for locating the DOI have been the limitations of this technique for defect review for 300 mm wafers. To address these limitations of AFM, automatic defect review AFM has been introduced recently [2], and is utilized in this work for studying DOI on 300 mm silicon wafer. In this work, we carefully etched a 300 mm silicon wafer with a gaseous acid in a reducing atmosphere at a temperature and for a sufficient duration to decorate and grow the crystal defects to a size capable of being detected as light scattering defects [3]. The etched defects form a shallow structure and their distribution and relative size are inspected by laser light scattering (LLS). However, several groups of defects couldn't be properly sized by the LLS due to the very shallow depth and low

  9. Rotational defects in cyclotrimethylene trinitramine (RDX) crystals

    SciTech Connect

    Pal, A.; Picu, R. C.

    2014-01-28

    Cyclotrimethylene trinitramine (RDX) crystalizes in the orthorhombic α-phase at the ambient pressure and temperature. In principle, the point defects commonly found in monatomic crystals, such as vacancies and interstitials, may exist in RDX as well. However, in molecular crystals one encounters additional point defects associated with the distortion of the molecules. A set of rotational defects are described in this article. These are molecules which are located in the proper positions in the crystal but are rotated relative to the molecules in the perfect crystal, and their ring is slightly puckered. The energetic barriers for defect formation and for their annealing back to the perfect crystal configuration are computed using an atomistic model. It is shown that the formation energy of rotational defects is smaller than the vacancy formation energy. Such defects are identified in the cores of dislocations in RDX and hence their concentration in the crystal is expected to increase during plastic deformation. The importance of such point defects is related to their role in phonon scattering and in dislocation-mediated plastic deformation.

  10. Reduction in Defect Content in ODS Alloys

    SciTech Connect

    Ritherdon, J.; Jones, A.R.

    2000-02-01

    The work detailed within this report is a continuation of earlier work that was carried out under contract number IDX-SY382V. The earlier work comprised a literature review of the sources and types of defects found principally in Fe-based ODS alloys together with a series of experiments designed to identify defects in ODS Fe{sub 3}Al material and recommend methods of defect reduction. Defects found in the Mechanically Alloyed (MA) ODS Fe{sub 3}Al included regions of incomplete MA, porosity, intrusions and fine-grained stringers. Some defects tended to be found in association with one another e.g. intrusions and fine-grained stringers. Preliminary powder separation experiments were also performed. The scope and objectives of the present work were laid out in the technical proposal ``Reduction in Defect Content in ODS Alloys--II'' which formed the basis of amendment 3 of the current contract. The current studies were devised in the context of the preceding work with a view to extending and concluding certain experiments while exploring new avenues of investigation of defect control and reduction where appropriate. All work proposed was within the context of achieving an ODS Fe{sub 3}Al alloy of improved overall quality and potential creep performance (particularly) in the consolidated, release condition. The interim outturn of the experimental work performed is also reported.

  11. Robust defect segmentation in woven fabrics

    SciTech Connect

    Sari-Sarraf, H.; Goddard, J.S. Jr.

    1997-12-01

    This paper describes a robust segmentation algorithm for the detection and localization of woven fabric defects. The essence of the presented segmentation algorithm is the localization of those events (i.e., defects) in the input images that disrupt the global homogeneity of the background texture. To this end, preprocessing modules, based on the wavelet transform and edge fusion, are employed with the objective of attenuating the background texture and accentuating the defects. Then, texture features are utilized to measure the global homogeneity of the output images. If these images are deemed to be globally nonhomogeneous (i.e., defects are present), a local roughness measure is used to localize the defects. The utility of this algorithm can be extended beyond the specific application in this work, that is, defect segmentation in woven fabrics. Indeed, in a general sense, this algorithm can be used to detect and to localize anomalies that reside in images characterized by ordered texture. The efficacy of this algorithm has been tested thoroughly under realistic conditions and as a part of an on-line fabric inspection system. Using over 3700 images of fabrics, containing 26 different types of defects, the overall detection rate of this approach was 89% with a localization accuracy of less than 0.2 inches and a false alarm rate of 2.5%.

  12. Exploring atomic defects in molybdenum disulphide monolayers

    NASA Astrophysics Data System (ADS)

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-02-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 1013 cm-2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices.

  13. Exploring atomic defects in molybdenum disulphide monolayers

    PubMed Central

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-01-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment–theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 1013 cm−2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices. PMID:25695374

  14. Defects and impurities in mercuric iodine processing

    SciTech Connect

    van Scyoc, J.M.; James, R.B.; Schlesinger, T.E.; Gilbert, T.S.

    1996-03-01

    In the fabrication of mercuric iodide HgI{sub 2} room temperature radiation detectors, as in any semiconductor process, the quality of the final device is very sensitive to the impurities and defects present. Each process step can change the effects of existing defects, reduce the number of defects, or introduce new defects. In HgI{sub 2} detectors these defects act as trapping and recombination centers, thereby degrading immediate performance and leading to unstable devices. In this work we characterized some of the defects believed to strongly affect detector operation. Specifically, we studied impurities that are known to be present in typical HgI{sub 2} materials. Leakage current measurements were used to study the introduction and characteristics of these impurities, as such experiments reveal the mobile nature of these defects. In particular, we found that copper, which acts as a hole trap, introduces a positively charged center that diffuses and drifts readily in typical device environments. These measurements suggest that Cu, and related impurities like silver, may be one of the leading causes of HgI{sub 2} detector failures.

  15. Modeling of Powder Bed Manufacturing Defects

    NASA Astrophysics Data System (ADS)

    Mindt, H.-W.; Desmaison, O.; Megahed, M.; Peralta, A.; Neumann, J.

    2017-09-01

    Powder bed additive manufacturing offers unmatched capabilities. The deposition resolution achieved is extremely high enabling the production of innovative functional products and materials. Achieving the desired final quality is, however, hampered by many potential defects that have to be managed in due course of the manufacturing process. Defects observed in products manufactured via powder bed fusion have been studied experimentally. In this effort we have relied on experiments reported in the literature and—when experimental data were not sufficient—we have performed additional experiments providing an extended foundation for defect analysis. There is large interest in reducing the effort and cost of additive manufacturing process qualification and certification using integrated computational material engineering. A prerequisite is, however, that numerical methods can indeed capture defects. A multiscale multiphysics platform is developed and applied to predict and explain the origin of several defects that have been observed experimentally during laser-based powder bed fusion processes. The models utilized are briefly introduced. The ability of the models to capture the observed defects is verified. The root cause of the defects is explained by analyzing the numerical results thus confirming the ability of numerical methods to provide a foundation for rapid process qualification.

  16. Defects and metrology of ultrathin resist films

    NASA Astrophysics Data System (ADS)

    Okoroanyanwu, Uzodinma; Cobb, Jonathan L.; Dentinger, Paul M.; Henderson, Craig C.; Rao, Veena; Monahan, Kevin M.; Luo, David; Pike, Christopher

    2000-06-01

    Defectivity in spin-coated, but unpatterned ultrathin resist (UTR) films (defectivity will present an issue in EUV (13.4-nm) and 157-nm lithographic technologies. These are the lithographic regimes where absorption issues mandate the use of ultrathin resists. Four resist samples formulated from the same Shipley UV6 polymer batch and having the same polymer molecular weight properties but different viscosities, were spin-coated at spin speeds ranging from 1000 to 5000 RPM on a production-grade track in a Class 1 pilot line facility. Defect inspection was carried out with KLA SP1/TBI tool, while defect review was carried out with JEOL 7515 SEM tool and KLA Ultrapointe Confocal Review Station (CRS) Microscope. The results obtained are related to the physical properties of the resist polymers, as well as to spin coating parameters. Also, the results of the defect inspection, review, characterization, and pareto are compared to those obtained on baseline thick resists (>= 3500 Angstrom) processed under similar condition as the ultra-thin resists. The results show that for a well-optimized coating process and within the thickness range explored (800 - 4200 Angstrom), there is no discernible dependence of defectivity on film thickness of the particular resists studied and on spin speed. Also assessed is the capability of the current metrology toolset for inspecting, reviewing, and classifying the various types of defects in UTR films.

  17. Platelet rich fibrin in jaw defects

    NASA Astrophysics Data System (ADS)

    Nica, Diana; Ianes, Emilia; Pricop, Marius

    2016-03-01

    Platelet rich fibrin (PRF) is a tissue product of autologous origin abundant in growth factors, widely used in regenerative procedures. Aim of the study: Evaluation of the regenerative effect of PRF added in the bony defects (after tooth removal or after cystectomy) Material and methods: The comparative nonrandomized study included 22 patients divided into 2 groups. The first group (the test group) included 10 patients where the bony defects were treated without any harvesting material. The second group included 12 patients where the bony defects were filled with PRF. The bony defect design was not critical, with one to two walls missing. After the surgeries, a close clinically monitoring was carried out. The selected cases were investigated using both cone beam computer tomography (CBCT) and radiographic techniques after 10 weeks postoperatively. Results: Faster bone regeneration was observed in the bony defects filled with PRF comparing with the not grafted bony defects. Conclusions: PRF added in the bony defects accelerates the bone regeneration. This simplifies the surgical procedures and decreases the economic costs.

  18. Geometric defects in quantum Hall states

    NASA Astrophysics Data System (ADS)

    Gromov, Andrey

    2016-08-01

    We describe a geometric (or gravitational) analog of the Laughlin quasiholes in fractional quantum Hall states. Analogously to the quasiholes, these defects can be constructed by an insertion of an appropriate vertex operator into the conformal block representation of a trial wave function; however, unlike the quasiholes these defects are extrinsic and do not correspond to true excitations of the quantum fluid. We construct a wave function in the presence of such defects and explain how to assign an electric charge and a spin to each defect and calculate the adiabatic, non-Abelian statistics of the defects. The defects turn out to be equivalent to the genons in that their adiabatic exchange statistics can be described in terms of representations of the mapping class group of an appropriate higher genus Riemann surface. We present a general construction that, in principle, makes it possible to calculate the statistics of Zn genons for any "parent" topological phase. We illustrate the construction on the example of the Laughlin state and perform an explicit calculation of the braiding matrices. In addition to non-Abelian statistics, geometric defects possess a universal Abelian overall phase, determined by the gravitational anomaly.

  19. Rail Defect Detection Using Ultrasonic Surface Waves

    NASA Astrophysics Data System (ADS)

    Edwards, R. S.; Jian, X.; Fan, Y.; Dixon, S.

    2006-03-01

    Current testing of the rail network is limited in terms of both speed of testing and accuracy of detecting surface defects such as gauge corner cracking. By using ultrasonic surface waves generated and detected in a pitch-catch manner we can detect such defects with a much higher accuracy. We use electro-magnetic acoustic transducers (EMATs) to generate and detect the ultrasound. These have the advantage of being non-contact and require no couplant. It is not sufficient to merely detect the presence of a defect; hence accurate calibration of the system is required. We present measurements on calibration samples giving the response of the system to defects of different depths. Further experiments have been performed on rail samples containing real and manufactured defects, both longitudinal and transverse. Using the change in signal amplitude and frequency content we are able to give a depth and position for these defects, and these are compared with more established measurement methods. An enhancement of the signal when the receive EMAT is close to the defect is also discussed.

  20. 48 CFR 1652.215-70 - Rate Reduction for Defective Pricing or Defective Cost or Pricing Data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Defective Pricing or Defective Cost or Pricing Data. 1652.215-70 Section 1652.215-70 Federal Acquisition... or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall be... of cost and price analysis (community rated): Rate Reduction for Defective Pricing or Defective Cost...

  1. Defects in liquid crystal nematic shells

    NASA Astrophysics Data System (ADS)

    Fernandez-Nieves, A.; Utada, A. S.; Vitelli, V.; Link, D. R.; Nelson, D. R.; Weitz, D. A.

    2006-03-01

    We generate water/liquid crystal (LC)/water double emulsions via recent micro-capillary fluidic devices [A. S. Utada, et.al. Science 308, 537 (2005)]. The resultant objects are stabilized against coalescence by using surfactants or adequate polymers; these also fix the boundary conditions for the director field n. We use 4-pentyl-4-cyanobiphenyl (5CB) and impose tangential boundary conditions at both water/LC interfaces by having polyvinyl alcohol (PVA) dispersed in the inner and outer water phases. We confirm recent predictions [D. R. Nelson, NanoLetters 2, 1125 (2002)] and find that four strength s=+1/2 defects are present; this is in contrast to the two s=+1 defect bipolar configuration observed for bulk spheres [A. Fernandez-Nieves, et.al. Phys. Rev. Lett. 92, 105503 (2004)]. However, these defects do not lie in the vertices of a tetrahedron but are pushed towards each other until certain equilibration distance is reached. In addition to the four defect shells, we observe shells with two s=+1 defects and even with three defects, a s=+1 and two s=+1/2. We argue these configurations arise from nematic bulk distortions that become important as the shell thickness increases. Finally, by adding a different surfactant, sodium dodecyl sulphate (SDS), to the outer phase, we can change the director boundary conditions at the outermost interface from parallel to homeotropic, to induce coalescing of the two pair of defects in the four defect shell configuration to yield two defect bipolar shells.

  2. Management of extensive frontal cranioplasty defects.

    PubMed

    Hatamleh, Muhanad M; Cartmill, Maria; Watson, Jason

    2013-11-01

    Cranioplasty is a medical technique to correct cranial bone defects. Depending on the size and location of the defect, a bone substitute can be used to replace the missing bone. Frontal bone defects are important to patients in terms of cosmetics because they are visible. Advances in computer design allow the production of customized implants with improved cosmetic and functional results. This report describes hybrid optimization of three-dimensional technological methods along with traditional methods toward the manufacture of deep-buried titanium implants, restoring frontal skull defects for 4 patients. A three-dimensional model was produced from the computed tomographic scan data of 3 patients using an in-house three-dimensional printer. A new approach was followed in treating the fourth patient. The defect was restored using preoperative scan before cranioplasty. These data were transported digitally into the defect skull to recreate the bone contour required, and a three-dimensional model was produced from the "new" digital model using the three-dimensional printer. Defect areas of the patients were large and measured 101.21 × 123.35 (vertical × horizontal) in average (mm). Conventional wax-up of the defect was carried to restore normal conformity. A titanium sheet (0.5 mm) was swaged into the desired shape; however, convexity of the defect area makes titanium swaging challenging, especially at the deep lateral undercuts. Making side flanges at reasonable lengths made it easy to swage without creasing. Three-dimensional models aided to produce accurately fitting plates. Finally, the sequential method of using both digital and manual procedures is a low-cost, reliable, accurate, and reproducible method.

  3. Phenol dissociation on pristine and defective graphene

    NASA Astrophysics Data System (ADS)

    Widjaja, Hantarto; Oluwoye, Ibukun; Altarawneh, Mohammednoor; Hamra, A. A. B.; Lim, H. N.; Huang, N. M.; Yin, Chun-Yang; Jiang, Zhong-Tao

    2017-03-01

    Phenol (C6H5O‒H) dissociation on both pristine and defective graphene sheets in terms of associated enthalpic requirements of the reaction channels was investigated. Here, we considered three common types of defective graphene, namely, Stone-Wales, monovacancy and divacancy configurations. Theoretical results demonstrate that, graphene with monovacancy creates C atoms with dangling bond (unpaired valence electron), which remains particularly useful for spontaneous dissociation of phenol into phenoxy (C6H5O) and hydrogen (H) atom. The reactions studied herein appear barrierless with reaction exothermicity as high as 2.2 eV. Our study offers fundamental insights into another potential application of defective graphene sheets.

  4. Model based defect characterization in composites

    NASA Astrophysics Data System (ADS)

    Roberts, R.; Holland, S.

    2017-02-01

    Work is reported on model-based defect characterization in CFRP composites. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing multi-ply impact-induced delamination, with application in this paper focusing on ultrasound. A companion paper in these proceedings summarizes corresponding activity in thermography. Inversion of ultrasound data is demonstrated showing the quantitative extraction of damage properties.

  5. Defect-free switchable phase grating.

    PubMed

    Lester, Garry A; Coulston, Stephen J; Strudwick, Adrian M

    2006-01-01

    Liquid-crystal-filled polymer structure devices offer a very low cost switchable spatial phase modulator. The phase profile set by the polymer structure may be varied or switched on/off with an applied field. Defects have been observed in some devices giving rise to spurious diffraction peaks. Computational modeling of the liquid-crystal director profile suggests that these defects might be suppressed if the dimensions of the liquid-crystal region are small. Experimental measurements confirm that this approach is effective in controlling the defects. This provides a route to fabrication of low-cost switchable complex diffractive devices.

  6. Defect-tolerant extreme ultraviolet nanoscale printing.

    PubMed

    Urbanski, L; Isoyan, A; Stein, A; Rocca, J J; Menoni, C S; Marconi, M C

    2012-09-01

    We present a defect-free lithography method for printing periodic features with nanoscale resolution using coherent extreme ultraviolet light. This technique is based on the self-imaging effect known as the Talbot effect, which is produced when coherent light is diffracted by a periodic mask. We present a numerical simulation and an experimental verification of the method with a compact extreme ultraviolet laser. Furthermore, we explore the extent of defect tolerance by testing masks with different defect layouts. The experimental results are in good agreement with theoretical calculations.

  7. Rational defect introduction in silicon nanowires.

    PubMed

    Shin, Naechul; Chi, Miaofang; Howe, Jane Y; Filler, Michael A

    2013-05-08

    The controlled introduction of planar defects, particularly twin boundaries and stacking faults, in group IV nanowires remains challenging despite the prevalence of these structural features in other nanowire systems (e.g., II-VI and III-V). Here we demonstrate how user-programmable changes to precursor pressure and growth temperature can rationally generate both transverse twin boundaries and angled stacking faults during the growth of <111> oriented Si nanowires. We leverage this new capability to demonstrate prototype defect superstructures. These findings yield important insight into the mechanism of defect generation in semiconductor nanowires and suggest new routes to engineer the properties of this ubiquitous semiconductor.

  8. Genetics Home Reference: congenital bile acid synthesis defect type 2

    MedlinePlus

    ... bile acid synthesis defect type 2 congenital bile acid synthesis defect type 2 Printable PDF Open All ... view the expand/collapse boxes. Description Congenital bile acid synthesis defect type 2 is a disorder characterized ...

  9. Genetics Home Reference: congenital bile acid synthesis defect type 1

    MedlinePlus

    ... bile acid synthesis defect type 1 congenital bile acid synthesis defect type 1 Printable PDF Open All ... view the expand/collapse boxes. Description Congenital bile acid synthesis defect type 1 is a disorder characterized ...

  10. 43 CFR 3830.93 - When are defects curable?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... curable? (a) If there is a defect in your compliance with a statutory requirement, the defect is incurable... of this chapter). If your payment, recording, or filing has incurable defects, the affected mining...

  11. New Guidelines Reaffirm Prenatal Folic Acid to Curb Birth Defects

    MedlinePlus

    ... that folic acid supplements reduce the risk of neural tube defects. As it advised in 2009, the independent ... acid to prevent these potentially fatal birth defects. Neural tube defects occur when the brain or spinal cord ...

  12. Defect chemistry and defect engineering of TiO2-based semiconductors for solar energy conversion.

    PubMed

    Nowotny, Janusz; Alim, Mohammad Abdul; Bak, Tadeusz; Idris, Mohammad Asri; Ionescu, Mihail; Prince, Kathryn; Sahdan, Mohd Zainizan; Sopian, Kamaruzzaman; Mat Teridi, Mohd Asri; Sigmund, Wolfgang

    2015-12-07

    This tutorial review considers defect chemistry of TiO2 and its solid solutions as well as defect-related properties associated with solar-to-chemical energy conversion, such as Fermi level, bandgap, charge transport and surface active sites. Defect disorder is discussed in terms of defect reactions and the related charge compensation. Defect equilibria are used in derivation of defect diagrams showing the effect of oxygen activity and temperature on the concentration of both ionic and electronic defects. These defect diagrams may be used for imposition of desired semiconducting properties that are needed to maximize the performance of TiO2-based photoelectrodes for the generation of solar hydrogen fuel using photo electrochemical cells (PECs) and photocatalysts for water purification. The performance of the TiO2-based semiconductors is considered in terms of the key performance-related properties (KPPs) that are defect related. It is shown that defect engineering may be applied for optimization of the KPPs in order to achieve optimum performance.

  13. The analysis of EUV mask defects using a wafer defect inspection system

    NASA Astrophysics Data System (ADS)

    Cho, Kyoung-Yong; Park, Joo-On; Park, Changmin; Lee, Young-Mi; Kang, In-Yong; Yeo, Jeong-Ho; Choi, Seong-Woon; Park, Chan-Hoon; Lange, Steven R.; Cho, SungChan; Danen, Robert M.; Kirk, Gregory L.; Pae, Yeon-Ho

    2010-04-01

    EUVL is the strongest candidate for a sub-20nm lithography solution after immersion double-patterning. There are still critical challenges for EUVL to address to become a mature technology like today's litho workhorse, ArF immersion. Source power and stability, resist resolution and LWR (Line Width Roughness), mask defect control and infrastructure are listed as top issues. Source power has shown reasonably good progress during the last two years. Resist resolution was proven to resolve 32nm HP (Half Pitch) lines and spaces with good process windows even though there are still concerns with LWR. However, the defectivity level of blank masks is still three orders of magnitude higher than the requirement as of today. In this paper, mask defect control using wafer inspection is studied as an alternative solution to mask inspection for detection of phase defects on the mask. A previous study suggested that EUVL requires better defect inspection sensitivity than optical lithography because EUVL will print smaller defects. Improving the defect detection capability involves not only inspection system but also wafer preparation. A few parameters on the wafer, including LWR and wafer stack material and thickness are investigated, with a goal of enhancing the defect capture rate for after development inspection (ADI) and after cleaning inspection (ACI). In addition to defect sensitivity an overall defect control methodology will be suggested, involving mask, mask inspection, wafer print and wafer inspection.

  14. ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer

    NASA Astrophysics Data System (ADS)

    Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2016-05-01

    At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

  15. Nanoparticle Solubility in Liquid Crystalline Defects

    NASA Astrophysics Data System (ADS)

    Whitmer, Jonathan K.; Armas-Perez, Julio C.; Joshi, Abhijeet A.; Roberts, Tyler F.; de Pablo, Juan J.

    2013-03-01

    Liquid crystalline materials often incorporate regions (defects) where the orientational ordering present in the bulk phase is disrupted. These include point hedgehogs, line disclinations, and domain boundaries. Recently, it has been shown that defects will accumulate impurities such as small molecules, monomer subunits or nanoparticles. Such an effect is thought to be due to the alleviation of elastic stresses within the bulk phase, or to a solubility gap between a nematic phase and the isotropic defect core. This presents opportunities for encapsulation and sequestration of molecular species, in addition to the formation of novel structures within a nematic phase through polymerization and nanoparticle self-assembly. Here, we examine the solubility of nanoparticles within a coarse-grained liquid crystalline phase and demonstrate the effects of nanoparticle size and surface interactions in determining sequestration into defect regions.

  16. New Device Approved for Esophageal Birth Defect

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_165596.html New Device Approved for Esophageal Birth Defect Condition affects ... 2017 MONDAY, May 15, 2017 (HealthDay News) -- A new medical device has been approved by the U.S. ...

  17. Reduction of Defects in Jewelry Manufacturing

    NASA Astrophysics Data System (ADS)

    Ayudhya, Phitchaya Phanomwan na; Tangjitsitcharoen, Somkiat

    2017-06-01

    The aim of this research was to reduce the defects of gem bracelet found during manufacturing process at a jewelry company. It was found that gem bracelet product has the highest rejects compared to the rejects found in ring, earring, and pendant products. Types of defect were classified by using Pareto Diagram consisting of gem falling, seam, unclean casting, impinge, and deformation. The causes of defect were analyzed by Cause and Effect Diagram and applied Failure Mode and Effects Analysis (FMEA) was applied during manufacturing processes. This research found that the improvement of manufacturing process could reduce the Risk Priority Number (RPN) and total of all defects by 48.70% and 48.89%, respectively.

  18. Infrared computations of defect Schur indices

    SciTech Connect

    Córdova, Clay; Gaiotto, Davide; Shao, Shu-Heng

    2016-11-18

    We conjecture a formula for the Schur index of four-dimensional N = 2 theories in the presence of boundary conditions and/or line defects, in terms of the low-energy effective Seiberg-Witten description of the system together with massive BPS excitations. We test our proposal in a variety of examples for SU(2) gauge theories, either conformal or asymptotically free. We use the conjecture to compute these defect-enriched Schur indices for theories which lack a Lagrangian description, such as Argyres-Douglas theories. We demonstrate in various examples that line defect indices can be expressed as sums of characters of the associated two-dimensional chiral algebra and that for Argyres-Douglas theories the line defect OPE reduces in the index to the Verlinde algebra.

  19. Genetic Counseling for Congenital Heart Defects

    MedlinePlus

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Genetic Counseling for Congenital Heart Defects Updated:Sep 12, ... person with congenital heart disease considers having children. Genetic counseling can help answer these questions and address ...

  20. Defect scanning technology in the works

    Treesearch

    Philip A. Araman; R. Conners

    1994-01-01

    This article describes the defect scanning technology being developed by Virginia Tech and U.S. Forest Service scientists in Blacksburg, Virginia to scan full sized hardwood lumber at industrial speeds.

  1. Dental Enamel Defects and Celiac Disease

    MedlinePlus

    ... Follow Us Home Health Information Digestive Diseases Dental Enamel Defects and Celiac Disease Related Topics Section Navigation Digestive Diseases Abdominal Adhesions Acid Reflux (GER & GERD) in Adults Definition & Facts ...

  2. When Your Baby Has a Birth Defect

    MedlinePlus

    ... as heart defects, cleft lip and palate, or cerebral palsy. Still, you may find yourself being both the ... the NICU Gene Therapy and Children Down Syndrome Cerebral Palsy Spina Bifida Prenatal Genetic Counseling What Is a ...

  3. Defect properties of ZnO nanowires

    NASA Astrophysics Data System (ADS)

    Stehr, J. E.; Devika, M.; Reddy, N. Koteeswara; Tu, C. W.; Chen, W. M.; Buyanova, I. A.

    2014-02-01

    In this work we examined optical and defect properties of as-grown and Ni-coated ZnO nanowires (NWs) grown by rapid thermal chemical vapor deposition by means of optically detected magnetic resonance (ODMR). Several grown-in defects are revealed by monitoring visible photoluminescence (PL) emissions and are attributed to Zn vacancies, O vacancies, a shallow (but not effective mass) donor and exchange-coupled pairs of a Zn vacancy and a Zn interstitial. It is also found that the same ODMR signals are detected in the as-grown and Ni-coated NWs, indicating that metal coatings does not significantly affect formation of the aforementioned defects and that the observed defects are located in the bulk of the NWs.

  4. Visualization of columnar defects in superconductors

    NASA Astrophysics Data System (ADS)

    Bauer, P.; Rossel, C.; Williams, E. J.; Berger, R.; Daniel, J.; Irmer, B.; Kraus, M.; Kreiselmeyer, G.; Saemann-Ischenko, G.; Karpinski, J.

    1996-02-01

    Columnar defects in single crystals of superconductors were investigated using scanning probe microscopy. We show that the observable topography strongly depends on the crystal structure as well as on the type of the interaction with the probe. In scanning tunneling microscopy studies, the low conductance of the amorphous tracks leads to tip-surface contact. Owing to this contact, the defects are imaged as hollows having a depth that primarily reflects the tunneling distance. For the high transition temperature materials, atomic force microscopy images the real defect structure as hillocks growing out of the surface. This outgrowth of amorphous material is time dependent and produced by the relaxation of irradiation-induced stress. The dynamic outgrowth of the columnar defects is discussed in terms of a so-called “tooth paste” model.

  5. Molecular Mechanisms of Midfacial Developmental Defects

    PubMed Central

    Suzuki, Akiko; Sangani, Dhruvee R.; Ansari, Afreen; Iwata, Junichi

    2015-01-01

    The morphogenesis of midfacial processes requires the coordination of a variety of cellular functions of both mesenchymal and epithelial cells to develop complex structures. Any failure or delay in midfacial development as well as any abnormal fusion of the medial and lateral nasal and maxillary prominences will result in developmental defects in the midface with a varying degree of severity, including cleft, hypoplasia, and midline expansion. In spite of the advances in human genome sequencing technology, the causes of nearly 70 percent of all birth defects, which include midfacial development defects, remain unknown. Recent studies in animal models have highlighted the importance of specific signaling cascades and genetic-environmental interactions in the development of the midfacial region. This review will summarize the current understanding of the morphogenetic processes and molecular mechanisms underlying midfacial birth defects based on mouse models with midfacial developmental abnormalities. PMID:26562615

  6. Residual Defect Density in Random Disks Deposits

    PubMed Central

    Topic, Nikola; Pöschel, Thorsten; Gallas, Jason A. C.

    2015-01-01

    We investigate the residual distribution of structural defects in very tall packings of disks deposited randomly in large channels. By performing simulations involving the sedimentation of up to 50 × 109 particles we find all deposits to consistently show a non-zero residual density of defects obeying a characteristic power-law as a function of the channel width. This remarkable finding corrects the widespread belief that the density of defects should vanish algebraically with growing height. A non-zero residual density of defects implies a type of long-range spatial order in the packing, as opposed to only local ordering. In addition, we find deposits of particles to involve considerably less randomness than generally presumed. PMID:26235809

  7. Phase measurements of EUV mask defects

    DOE PAGES

    Claus, Rene A.; Wang, Yow-Gwo; Wojdyla, Antoine; ...

    2015-02-22

    Extreme Ultraviolet (EUV) Lithography mask defects were examined on the actinic mask imaging system, SHARP, at Lawrence Berkeley National Laboratory. Also, a quantitative phase retrieval algorithm based on the Weak Object Transfer Function was applied to the measured through-focus aerial images to examine the amplitude and phase of the defects. The accuracy of the algorithm was demonstrated by comparing the results of measurements using a phase contrast zone plate and a standard zone plate. Using partially coherent illumination to measure frequencies that would otherwise fall outside the numerical aperture (NA), it was shown that some defects are smaller than themore » conventional resolution of the microscope. We found that the programmed defects of various sizes were measured and shown to have both an amplitude and a phase component that the algorithm is able to recover.« less

  8. Phase measurements of EUV mask defects

    SciTech Connect

    Claus, Rene A.; Wang, Yow-Gwo; Wojdyla, Antoine; Benk, Markus P.; Goldberg, Kenneth A.; Neureuther, Andrew R.; Naulleau, Patrick P.; Waller, Laura

    2015-02-22

    Extreme Ultraviolet (EUV) Lithography mask defects were examined on the actinic mask imaging system, SHARP, at Lawrence Berkeley National Laboratory. Also, a quantitative phase retrieval algorithm based on the Weak Object Transfer Function was applied to the measured through-focus aerial images to examine the amplitude and phase of the defects. The accuracy of the algorithm was demonstrated by comparing the results of measurements using a phase contrast zone plate and a standard zone plate. Using partially coherent illumination to measure frequencies that would otherwise fall outside the numerical aperture (NA), it was shown that some defects are smaller than the conventional resolution of the microscope. We found that the programmed defects of various sizes were measured and shown to have both an amplitude and a phase component that the algorithm is able to recover.

  9. National Birth Defects Prevention Study (NBDPS)

    MedlinePlus

    ... taking multivitamins before their pregnancy. [ Read Summary ] Air Pollution and Congenital Heart Defects Many pregnant women, especially ... air quality standards to limit the amount of pollution in our air, we still do not know ...

  10. Defect trapping in ABC block copolymers

    NASA Astrophysics Data System (ADS)

    Corte, Laurent; Yamauchi, Kazuhiro; Court, Francois; Cloitre, Michel; Hashimoto, Takeji; Leibler, Ludwik

    2004-03-01

    Equilibrium morphologies in molten ABC triblock terpolymers are much more difficult to attain than in AB diblocks. In practice, it is important to know whether and how synthesis conditions influence the morphology and properties of copolymer materials. It is also relevant to understand the mechanisms of defect formation and annihilation. Indeed, a potential use of copolymers in new applications such as lithography highly depends on the ability to produce regular structures with no or few defects. We show that even the simplest lamellar structures exhibit high sensitivity to preparation conditions and that strongly trapped structural defects inherent to ABC triblock architecture cannot be removed by long annealing. Annealing can induce a transition from a lamellar structure in which A and C blocks are mixed to a lamellar structure where A, B and C are segregated. We propose reorganization mechanisms that are at the origin of some characteristic defects.

  11. Dislocation-Defect Interactions in Materials

    SciTech Connect

    Robach, J S; Robertson, I M; Ahn, D C; Sofronis, P; Wirth, B D; Arsenlis, T

    2003-02-27

    In order to develop predictive models of the mechanical response of irradiated materials it is necessary to understand the fundamental physical processes controlling the deformation. This is particularly important near yielding where local defect interactions may dominate the behavior. Dislocation-defect interactions in copper containing various densities and distributions of stacking-fault tetrahedra and small dislocation loops were examined dynamically using the in-situ TEM straining technique. Defect annihilation mechanisms as well as the conditions required to produce defect-free channels are proposed. The experimental results are compared to atomistic simulations and continuum mechanics calculations of unit interactions. Based on these observations, an improved continuum model of the mechanical behavior of irradiated materials is presented.

  12. Exploration of defect structures on graphene.

    PubMed

    Yu, Shansheng; Zheng, Weitao

    2013-02-01

    For graphene obtained by chemical vapor deposition, there are large amount of defects in the crystalline structures. The carbon atoms from the feedstock can attack the graphene surface in annealing process, which may be one of the reasons affecting the structure of graphene. In order to explore some defect structures on graphene, we investigate the adsorption of carbon adatoms and vacancies on graphene using first-principles calculations. It is demonstrated that the adatoms can form strong covalent bonds with the graphene and the C-C dimmer adsorption may be the most prolific defect model. The C adatom can even fill simple vacancy of graphene. Our numerical simulations also show that the defect structures can lead to the splitting of the mid-gap peak of perfect graphene in the electronic structures. It is suggested that its conductivity would be lower than that of the perfect graphene, which can explain the low mobility of the charge carriers in some experiments.

  13. When Your Baby Has a Birth Defect

    MedlinePlus

    ... or a heart defect ) or functional/developmental (like Down syndrome , deafness, or a metabolic disorder like phenylketonuria). Some ... in the baby, which can cause problems like Down syndrome and Turner syndrome . amniocentesis and chorionic villi sampling. ...

  14. Infrared computations of defect Schur indices

    DOE PAGES

    Córdova, Clay; Gaiotto, Davide; Shao, Shu-Heng

    2016-11-18

    We conjecture a formula for the Schur index of four-dimensional N = 2 theories in the presence of boundary conditions and/or line defects, in terms of the low-energy effective Seiberg-Witten description of the system together with massive BPS excitations. We test our proposal in a variety of examples for SU(2) gauge theories, either conformal or asymptotically free. We use the conjecture to compute these defect-enriched Schur indices for theories which lack a Lagrangian description, such as Argyres-Douglas theories. We demonstrate in various examples that line defect indices can be expressed as sums of characters of the associated two-dimensional chiral algebramore » and that for Argyres-Douglas theories the line defect OPE reduces in the index to the Verlinde algebra.« less

  15. Instilling defect tolerance in new compounds

    NASA Astrophysics Data System (ADS)

    Walsh, Aron; Zunger, Alex

    2017-10-01

    The properties of semiconducting solids are determined by the imperfections they contain. Established physical phenomena can be converted into practical design principles for optimizing defects and doping in a broad range of technology-enabling materials.

  16. Microcephaly and Other Birth Defects: Zika

    MedlinePlus

    ... Español Recommend on Facebook Tweet Share Compartir Zika and Microcephaly Microcephaly is a birth defect in ... pregnancy or has stopped growing after birth. Congenital Zika Syndrome Congenital Zika syndrome is a unique pattern ...

  17. March of Dimes Birth Defects Foundation

    MedlinePlus

    ... unit (NICU) Birth defects & other health conditions Loss & grief Tools & Resources Frequently asked health questions Ask our ... experts Calculating your due date Ovulation calendar Order bereavement materials News Moms Need Blog News & Media News ...

  18. Holographic entanglement entropy of surface defects

    NASA Astrophysics Data System (ADS)

    Gentle, Simon A.; Gutperle, Michael; Marasinou, Chrysostomos

    2016-04-01

    We calculate the holographic entanglement entropy in type IIB supergravity solutions that are dual to half-BPS disorder-type surface defects in N=4 supersymmetric Yang-Mills theory. The entanglement entropy is calculated for a ball-shaped region bisected by a surface defect. Using the bubbling supergravity solutions we also compute the expectation value of the defect operator. Combining our result with the previously-calculated one-point function of the stress tensor in the presence of the defect, we adapt the calculation of Lewkowycz and Maldacena [1] to obtain a second expression for the entanglement entropy. Our two expressions agree up to an additional term, whose possible origin and significance is discussed.

  19. Topological defect dynamics in operando battery nanoparticles

    NASA Astrophysics Data System (ADS)

    Ulvestad, A.; Singer, A.; Clark, J. N.; Cho, H. M.; Kim, J. W.; Harder, R.; Maser, J.; Meng, Y. S.; Shpyrko, O. G.

    2015-06-01

    Topological defects can markedly alter nanomaterial properties. This presents opportunities for “defect engineering,” where desired functionalities are generated through defect manipulation. However, imaging defects in working devices with nanoscale resolution remains elusive. We report three-dimensional imaging of dislocation dynamics in individual battery cathode nanoparticles under operando conditions using Bragg coherent diffractive imaging. Dislocations are static at room temperature and mobile during charge transport. During the structural phase transformation, the lithium-rich phase nucleates near the dislocation and spreads inhomogeneously. The dislocation field is a local probe of elastic properties, and we find that a region of the material exhibits a negative Poisson’s ratio at high voltage. Operando dislocation imaging thus opens a powerful avenue for facilitating improvement and rational design of nanostructured materials.

  20. Observing Dissipative Topological Defects with Coupled Lasers

    NASA Astrophysics Data System (ADS)

    Pal, Vishwa; Tradonsky, Chene; Chriki, Ronen; Friesem, Asher A.; Davidson, Nir

    2017-07-01

    Topological defects have been observed and studied in a wide range of systems, such as cosmology, spin systems, cold atoms, and optics, as they are quenched across a phase transition into an ordered state. These defects limit the coherence of the system and its ability to approach a fully ordered state, so revealing their origin and control is becoming an increasingly important field of research. We observe dissipative topological defects in a one-dimensional ring of phased-locked lasers, and show how their formation is related to the Kibble-Zurek mechanism and is governed in a universal manner by two competing time scales. The ratio between these two time scales depends on the system parameters, and thus offers the possibility of enabling the system to dissipate to a fully ordered, defect-free state that can be exploited for solving hard computational problems in various fields.

  1. Pulmonary complications of abdominal wall defects.

    PubMed

    Panitch, Howard B

    2015-01-01

    The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

  2. Topological Defect Dynamics in Operando Battery Nanoparticles

    SciTech Connect

    Ulvestad, A; Singer, A; Clark, J. N.; Cho, H. M.; Kim, J.W.; Harder, R.; Maser, J.; Meng, Y.S.; Shpyrko, O.G.

    2015-06-19

    Topological defects can markedly alter nanomaterial properties. This presents opportunities for "defect engineering," where desired functionalities are generated through defect manipulation. However, imaging defects in working devices with nanoscale resolution remains elusive. We report three-dimensional imaging of dislocation dynamics in individual battery cathode nanoparticles under operando conditions using Bragg coherent diffractive imaging. Dislocations are static at room temperature and mobile during charge transport. During the structural phase transformation, the lithium-rich phase nucleates near the dislocation and spreads inhomogeneously. The dislocation field is a local probe of elastic properties, and we find that a region of the material exhibits a negative Poisson's ratio at high voltage. Operando dislocation imaging thus opens a powerful avenue for facilitating improvement and rational design of nanostructured materials.

  3. This Issue: Correlates of a Defective School.

    ERIC Educational Resources Information Center

    Gilman, David Alan

    1992-01-01

    Describes correlates of defective schools: perks for very few; faulty communication; adult-centered programs; special interest group indulgence; poor professional relationships; personnel warehousing; incompetent consultants; literal interpretation of technicalities; imperial leadership; intimate relationships among personnel; incoherent…

  4. Epidemiology of neural tube defects

    PubMed Central

    Seidahmed, Mohammed Z.; Abdelbasit, Omar B.; Shaheed, Meeralebbae M.; Alhussein, Khalid A.; Miqdad, Abeer M.; Khalil, Mohamed I.; Al-Enazy, Naif M.; Salih, Mustafa A.

    2014-01-01

    Objectives: To find the prevalence of neural tube defects (NTDs), and compare the findings with local and international data, and highlight the important role of folic acid supplementation and flour fortification with folic acid in preventing NTDs. Methods: This is a retrospective study of data retrieved from the medical records of live newborn infants admitted to the Neonatal Intensive Care Unit (NICU), Security Forces Hospital (SFH), Riyadh, Saudi Arabia with NTDs spanning 14 years (1996-2009). All pregnant women on their first antenatal visit to the primary care clinic were prescribed folic acid 0.5 mg daily, or 5 mg if there is a family history of NTD. The pre-fortification prevalence is compared to post-fortification, before and after excluding syndromic, genetic, and chromosomal causes. The results were compared with reports from other parts of Saudi Arabia and internationally, through a literature search using MEDLINE. Results: The prevalence of NTDs during the period was 1.2 per 1000 live births. The pre-fortification of flour with folic acid prevalence was 1.46 per 1000 live births. The post-fortification prevalence was 1.05 (p=0.103). After excluding syndromic, genetic, and chromosomal causes from calculation of the prevalence, there was a significant reduction in the prevalence, from 1.46 to 0.81 per 1000 live births (p=0.0088). Syndromic, genetic, and chromosomal causes were identified in 20 cases (19.4%). Only 2% of mothers received preconception folic acid, and only 10% of them received it during the first 4 weeks of gestation. Conclusion: Despite the implementation of fortification of flour with folic acid since 2001, the prevalence of NTDs in the Kingdom of Saudi Arabia is still high. This is due to the impact of genetic, syndromic, and chromosomal causes of NTD not preventable by folic acid. Other factors like unplanned pregnancy and lack of awareness of the role of folic acid in preventing nonsyndromic causes, play a significant role. PMID

  5. Defect classes - an overdue paradigm for CMOS IC testing

    SciTech Connect

    Hawkins, C.F.; Soden, J.M.; Righter, A.W.; Ferguson, F.J.

    1994-09-01

    The IC test industry has struggled for more than 30 years to establish a test approach that would guarantee a low defect level to the customer. We propose a comprehensive strategy for testing CMOS ICs that uses defect classes based on measured defect electrical properties. Defect classes differ from traditional fault models. Our defect class approach requires that the test strategy match the defect electrical properties, while fault models require that IC defects match the fault definition. We use data from Sandia Labs failure analysis and test facilities and from public literature. We describe test pattern requirements for each defect class and propose a test paradigm.

  6. Medial Femoral Condyle Cartilage Defect Biomechanics: Effect of Obesity, Defect Size, and Cartilage Thickness.

    PubMed

    Lacy, Kyle W; Cracchiolo, Allison; Yu, Stephen; Goitz, Henry

    2016-02-01

    Medial femoral condyle (MFC) chondral defects cause knee pain. Clinical studies have shown worse functional outcomes and cartilage defect fill rates after microfracture in obese patients (BMI ≥30) and for defects with size ≥2 cm(2). To determine the effect of obesity, defect size, and cartilage thickness on the force sustained at the base of full-thickness MFC cartilage defects during weightbearing. Controlled laboratory study. Eight human cadaveric knees were loaded in 15° of flexion. A sensor measured force across the medial compartment. The area at the base of the defect protected from load, termed the "area of containment," was quantified, and loads simulating weightbearing for BMIs of 20, 30, and 40 were applied. A full-thickness cartilage defect was created on the MFC. Cycles of loads were applied for defect sizes with diameters of 6, 8, 10, 12, 14, 16, 18, and 20 mm. A second sensor recorded force at the base of the defect for defects with diameters of 14, 16, 18, and 20 mm. Loads simulating BMI ≥30 led to a decrease in the area of containment for all defects ≥14 mm in diameter (P ≤ .038). Base of defect force increased for defects ≥16 mm in diameter (area, ≥2 cm(2)) between loaded and unloaded states (P ≤ .042) and for loads simulating BMI ≥30 (P ≤ .045). Cartilage rim thickness <2 mm showed higher base of defect force than did thickness ≥2 mm, for all BMI groups (P ≤ .025). Increased force at the base of MFC cartilage defects was observed for weightbearing loads simulating BMI ≥30, for defect size ≥2 cm(2), and for rim thickness <2 mm. This may lead to a biomechanically unfavorable environment after microfracture in these patient subsets. These biomechanical findings corroborate clinical studies that have noted worse outcomes after microfracture in patients with BMI ≥30 and cartilage defects of size ≥2 cm(2). Further clinical studies are needed to compare microfracture with other cartilage restoration procedures in these

  7. Laparoscopic Repair of Cesarean Scar Defect "Isthmocele".

    PubMed

    Urman, Bulent; Arslan, Tonguc; Aksu, Sertan; Taskiran, Cagatay

    2016-01-01

    To demonstrate the technique of laparoscopic repair of a large cesarean scar defect (isthmocele). Case report (Canadian Task Force classification III). Cesarean scar defect, also known as an isthmocele, is the result of incomplete healing of the isthmic myometrium after a low transverse uterine incision performed for cesarean section. Although mostly asymptomatic, it may cause menstrual abnormalities (typically postmenstrual spotting), chronic pelvic pain, and secondary infertility. Scar tissue dehiscence, scar pregnancy, and abnormally adherent placenta are some of the obstetric complications associated with this defect. No standardized treatment has yet been accepted. Hysteroscopy and laparoscopy are the minimally invasive approaches currently used to repair the defect. A 40-year-old patient, G2P2, presented with postmenstrual spotting and secondary infertility for the past 2 years. She had a history of 2 previous cesarean deliveries. Transvaginal ultrasound revealed a large (2.5 × 1.5 cm) niche. Thickness of the myometrium over the defect was 3 mm. Laparoscopic repair of the uterine defect was performed. The bladder that was densely adherent to the lower uterine segment was freed by careful dissection. The defect was then localized with a sharp curette placed transcervically into the uterus. The curette was pushed anteriorly to delineate the margins of the defect and puncture the ceiling of the isthmocele cavity. The fibrotic tissue that formed the ceiling and the lateral borders of the defect was excised using laparoscopic scissors. Reapproximation of the edges was done with continuous nonlocking 3-0 V-Loc sutures. The procedure took 90 minutes, and there were no associated complications. Postoperative ultrasound performed in the second month after the operation showed a minimal defect measuring 0.5 cm, with a residual myometrial thickness of 7 mm. At the time of this writing, the patient was free of symptoms. Laparoscopic repair, although not

  8. [Unawareness for homonymous visual field defect].

    PubMed

    Ito, Tomoko; Hirayama, Kazumi; Yamawaki, Rie; Kondo, Yumiko; Sakai, Shinya; Kondo, Takeo; Yamadori, Atsushi

    2003-10-01

    There was no report which dealt with the relationship between emotional state, degree of defective visual search, severity of hemianopic dyslexia, the episode when the patient became aware of the defect, and unawareness of visual loss in homonymous hemifield. To investigate the relationship between degree of awareness and those factors that might be responsible for the unawareness, including the aspects listed above. Four patients with visual field defects caused by a brain lesion after a stroke was investigated. Self rating of emotional state, search performance for an object among many placed on a table, and for text reading, as well as visual field, visual positive phenomena, and hemispatial neglect were evaluated. Degree of unawareness for field loss was evaluated by modified version of the method of Bisiach et al. (1985). In addition, the episodes when the patient became aware of the defect were asked. In accordance with the previous studies, we found no relationship between the degree of awareness of field defect and anatomic lesions, co-existence of hemispatial neglect, or the degree of awareness of hemiplegia. However, the patient with neglect was unaware of their troubles in vision at all, whereas the patients without neglect were aware of the troubles but misinterpreted them as problems of the eyes including acuity. In accordance with previous studies, co-existence of visual hallucinations or illusions seemed to be associated with awareness of visual field defect. No relationship was found between the degree of awareness of field defect and emotional state, degree of field loss, degree of defective visual search, or severity of hemianopic dyslexia. Their responses to the inquiry about the degree of awareness of field defect were not consistent. Thus, the awareness of the field defect seemed to be difficult to be kept firmly in their mind. On the other hand, the patients could remember the episode when they became aware of the defect for the first time

  9. Corrosion of surface defects in fine wires.

    PubMed

    Rentler, R M; Greene, N D

    1975-11-01

    Defects were observed on the surfaces of various fine diameter wires commonly used in biomedical applications. These surface irregularities were viewed at high magnifications using a scanning electron microscope which has a much greater depth of field than normal light microscopy. Defects include scratches, pits, and crevices, which are the result of commercial wire drawing practices. Corrosion test results show that imperfections can serve as sites for localized corrosion attack which could lead to premature failures.

  10. Neutron-induced defects in optical fibers

    SciTech Connect

    Rizzolo, S.; Morana, A.; Boukenter, A.; Ouerdane, Y.; Girard, S.; Cannas, M.; Boscaino, R.; Bauer, S.; Perisse, J.; Mace, J-R.; Nacir, B.

    2014-10-21

    We present a study on 0.8 MeV neutron-induced defects up to fluences of 10{sup 17} n/cm{sup 2} in fluorine doped optical fibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of Silica-related point-defects such as E', H(I), POR and NBOH Centers.

  11. Defect structure of web silicon ribbon

    NASA Technical Reports Server (NTRS)

    Cunningham, B.; Strunk, H.; Ast, D.

    1980-01-01

    The results of a preliminary study of two dendritic web samples are presented. The structure and electrical activity of the defects in the silicon webs were studied. Optical microscopy of chemically etched specimens was used to determine dislocation densities. Samples were mechanically polished, then Secco etched for approximately 5 minutes. High voltage transmission electron microscopy was used to characterize the crystallographic nature of the defects.

  12. Neutron-induced defects in optical fibers

    NASA Astrophysics Data System (ADS)

    Rizzolo, S.; Morana, A.; Cannas, M.; Bauer, S.; Perisse, J.; Mace, J.-R.; Boscaino, R.; Boukenter, A.; Ouerdane, Y.; Nacir, B.; Girard, S.

    2014-10-01

    We present a study on 0.8 MeV neutron-induced defects up to fluences of 1017 n/cm2 in fluorine doped optical fibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of Silica-related point-defects such as E', H(I), POR and NBOH Centers.

  13. INNOVATIVE EDDY CURRENT PROBE FOR MICRO DEFECTS

    SciTech Connect

    Santos, Telmo G.; Vilaca, Pedro; Quintino, Luisa; Santos, Jorge dos; Rosado, Luis

    2010-02-22

    This paper reports the development of an innovative eddy current (EC) probe, and its application to micro-defects on the root of the Friction Stir Welding (FSW). The new EC probe presents innovative concept issues, allowing 3D induced current in the material, and a lift-off independence. Validation experiments were performed on aluminium alloys processed by FSW. The results clearly show that the new EC probe is able to detect and sizing surface defects about 60 microns depth.

  14. Defect Evolution in Graphene upon Electrochemical Lithiation

    SciTech Connect

    Jaber-Ansari, Laila; Puntambekar, Kanan Prakash; Tavassol, Hadi; Yildirim, Handan; Kinaci, Alper; Kumar, Rajan; Saldana, Spencer J.; Gewirth, Andrew A.; Greeley, J. P.; Chan, Maria K. Y.; Hersam, Mark C.

    2014-10-22

    Despite rapidly growing interest in the application of graphene in lithium ion batteries, the interaction of the graphene with lithium ions and electrolyte species during electrochemical cycling is not fully understood. In this work, we use Raman spectroscopy in a model system of monolayer graphene transferred on a Si(111) substrate and density functional theory (DFT) to investigate defect formation as a function of lithiation. This model system enables the early stages of defect formation to be probed in a manner previously not possible with commonly used reduced graphene oxide or multilayer graphene substrates. Using ex situ and Ar-atmosphere Raman spectroscopy, we detected a rapid increase in graphene defect level for small increments in the number of lithiation/delithiation cycles until the I(D)/I(G) ratio reaches ~1.5–2.0 and the 2D peak intensity drops by ~50%, after which the Raman spectra show minimal changes upon further cycling. Using DFT, the interplay between graphene topological defects and chemical functionalization is explored, thus providing insight into the experimental results. In particular, the DFT results show that defects can act as active sites for species that are present in the electrochemical environment such as Li, O, and F. Furthermore, chemical functionalization with these species lowers subsequent defect formation energies, thus accelerating graphene degradation upon cycling. This positive feedback loop continues until the defect concentration reaches a level where lithium diffusion through the graphene can occur in a relatively unimpeded manner, with minimal further degradation upon extended cycling. Overall, this study provides mechanistic insight into graphene defect formation during lithiation, thus informing ongoing efforts to employ graphene in lithium ion battery technology.

  15. Defects and Transport in Lithium Niobium Trioxide

    NASA Astrophysics Data System (ADS)

    Mehta, Apurva

    1990-01-01

    This dissertation presents work done on characterizing the defects and transport properties of congruent LiNbO _3. The focus of the study is the high temperature (800^circC to 1000^circC) equilibrium defect structure. The majority defects are described in terms of the 'LiNbO_3-ilmenite' defect model previously presented (26). Here the emphasis is placed on quantifying the defect concentrations. Congruent LiNbO_3 is highly nonstoichiometric. The large concentration of ionic defects present are mobile and contribute to electrical conduction. The ionic conduction was separated from the total conduction using defect chemistry and the transference number thus obtained was checked against the transference number obtained in a galvanic cell measurement. LiNbO_3 is an insulator (band gap = 4 eV). Hence one assumes that almost all of the conduction electrons are created by reduction. The degree of oxygen nonstoichiometry, a measure of the extent of chemical reduction, and the electron concentrations, were quantified as a function of oxygen partial pressure and the temperature by coulometric titration. The nonstoichiometry thus obtained was compared with nonstoichiometry obtained by TGA measurements. By fixing the phase composition of the sample in a buffered system, a set of constant composition measurements could be undertaken. These constant composition measurements were used to obtain the enthalpy of formation of conduction electrons, 1.95 eV, and the hopping energy for their motion at elevated temperatures, 0.55 eV, independently. The sum of the two energies was obtained by measuring the temperature dependence of the electronic conduction. The sum of the energies was found to be in excellent agreement with the energy obtained from equilibrium conduction. In conclusion, a quantitative and self-consistent picture of defects and their migration in LiNbO _3 was obtained.

  16. Topological Defects in Liquid Crystals: Studying the Correlation between Defects and Curvature

    NASA Astrophysics Data System (ADS)

    Melton, Charles

    2015-03-01

    Topological defects have recently been the subject of many fascinating studies in soft condensed matter physics. In particular, linking the evolution of topological defects to curvature changes has been a focus, leading possible applications in the areas such as cosmetics, pharmaceuticals, and electronics. In this study, defects in nematic liquid crystal droplets are investigated via laboratory and theoretical techniques. Nematic liquid crystal defects are reproduced via Monte Carlo simulations using a modified 2D XY-Model Hamiltonian. The simulation is performed on a curved surface to replicate a nematic droplet and examine possible defect configurations. To complement this theoretical work, we have trapped nematic droplets inside a dual-beam optical trap. This system allows controllable non-contact droplet deformation on a microscope based platform. Future work will focus on using the trap to stretch nematic droplets, correlating the changing topological defects with theoretical predictions.

  17. EUV actinic defect inspection and defect printability at the sub-32 nm half pitch

    SciTech Connect

    Huh, Sungmin; Kearney, Patrick; Wurm, Stefan; Goodwin, Frank; Han, Hakseung; Goldberg, Kenneth; Mochi, Iacopp; Gullikson, Eric M.

    2009-08-01

    Extreme ultraviolet (EUV) mask blanks with embedded phase defects were inspected with a reticle actinic inspection tool (AIT) and the Lasertec M7360. The Lasertec M7360, operated at SEMA TECH's Mask Blank Development Center (MBDC) in Albany, NY, has a sensitivity to multilayer defects down to 40-45 nm, which is not likely sufficient for mask blank development below the 32 nm half-pitch node. Phase defect printability was simulated to calculate the required defect sensitivity for a next generation blank inspection tool to support reticle development for the sub-32 nm half-pitch technology node. Defect mitigation technology is proposed to take advantage of mask blanks with some defects. This technology will reduce the cost of ownership of EUV mask blanks. This paper will also discuss the kind of infrastructure that will be required for the development and mass production stages.

  18. Defect Tolerant Semiconductors for Solar Energy Conversion.

    PubMed

    Zakutayev, Andriy; Caskey, Christopher M; Fioretti, Angela N; Ginley, David S; Vidal, Julien; Stevanovic, Vladan; Tea, Eric; Lany, Stephan

    2014-04-03

    Defect tolerance is the tendency of a semiconductor to keep its properties despite the presence of crystallographic defects. Scientific understanding of the origin of defect tolerance is currently missing. Here we show that semiconductors with antibonding states at the top of the valence band are likely to be tolerant to defects. Theoretical calculations demonstrate that Cu3N with antibonding valence band maximum has shallow intrinsic defects and no surface states, in contrast to GaN with bonding valence band maximum. Experimental measurements indicate shallow native donors and acceptors in Cu3N thin films, leading to 10(16)-10(17) cm(-3) doping with either electrons or holes depending on the growth conditions. The experimentally measured bipolar doping and the solar-matched optical absorption onset (1.4 eV) make Cu3N a promising candidate absorber for photovoltaic and photoelectrochemical solar cells, despite the calculated indirect fundamental band gap (1.0 eV). These conclusions can be extended to other materials with antibonding character of the valence band, defining a class of defect-tolerant semiconductors for solar energy conversion applications.

  19. Quality metrics for product defectiveness at KCD

    SciTech Connect

    Grice, J.V.

    1993-07-01

    Metrics are discussed for measuring and tracking product defectiveness at AlliedSignal Inc., Kansas City Division (KCD). Three new metrics, the metric (percent defective) that preceded the new metrics, and several alternatives are described. The new metrics, Percent Parts Accepted, Percent Parts Accepted Trouble Free, and Defects Per Million Observations, (denoted by PPA, PATF, and DPMO, respectively) were implemented for KCD-manufactured product and purchased material in November 1992. These metrics replace the percent defective metric that had been used for several years. The PPA and PATF metrics primarily measure quality performance while DPMO measures the effects of continuous improvement activities. The new metrics measure product quality in terms of product defectiveness observed only during the inspection process. The metrics were originally developed for purchased product and were adapted to manufactured product to provide a consistent set of metrics plant- wide. The new metrics provide a meaningful tool to measure the quantity of product defectiveness in terms of the customer`s requirements and expectations for quality. Many valid metrics are available and all will have deficiencies. These three metrics are among the least sensitive to problems and are easily understood. They will serve as good management tools for KCD in the foreseeable future until new flexible data systems and reporting procedures can be implemented that can provide more detailed and accurate metric computations.

  20. Reduction in Defect Content of ODS Alloys

    SciTech Connect

    Ritherdon, J

    2001-05-15

    The work detailed within this report is a continuation of earlier work carried out under contract number 1DX-SY382V. The earlier work comprises a literature review of the sources and types of defects found principally in Fe-based ODS alloys as well as experimental work designed to identify defects in the prototype ODS-Fe{sub 3}Al alloy, deduce their origins and to recommend methods of defect reduction. The present work is an extension of the experimental work already reported and concentrates on means of reduction of defects already identified rather than the search for new defect types. This report also includes results gathered during powder separation trials, conducted by the University of Groningen, Netherlands and coordinated by the University of Liverpool, involving the separation of different metallic powders in terms of their differing densities. The scope and objectives of the present work were laid out in the technical proposal ''Reduction in Defect Content in ODS Alloys-III''. All the work proposed in the ''Statement of Work'' section of the technical proposal has been carried out and all work extra to the ''Statement of Work'' falls within the context of an ODS-Fe{sub 3}Al alloy of improved overall quality and potential creep performance in the consolidated form. The outturn of the experimental work performed is reported in the following sections.

  1. A novel inspection system for cosmetic defects

    NASA Astrophysics Data System (ADS)

    Hazra, S.; Roy, R.; Williams, D.; Aylmore, R.; Hollingdale, D.

    2013-12-01

    The appearance of automotive skin panels creates desirability for a product and differentiates it from the competition. Because of the importance of skin panels, considerable care is taken in minimizing defects such as the 'hollow' defect that occur around door-handle depressions. However, the inspection process is manual, subjective and time-consuming. This paper describes the development of an objective and inspection scheme for the 'hollow' defect. In this inspection process, the geometry of a panel is captured using a structured lighting system. The geometry data is subsequently analyzed by a purpose-built wavelet-based algorithm to identify the location of any defects that may be present and to estimate the perceived severity of the defects without user intervention. This paper describes and critically evaluates the behavior of this physically-based algorithm on an ideal and real geometry and compares its result to an actual audit. The results show that the algorithm is capable of objectively locating and classifying 'hollow' defects in actual panels.

  2. Radiographic defect depth and width for prognosis and description of periodontal healing of infrabony defects.

    PubMed

    Klein, F; Kim, T S; Hassfeld, S; Staehle, H J; Reitmeir, P; Holle, R; Eickholz, P

    2001-12-01

    The aims of the present study were to evaluate 1) defect depth and width as a prognostic factor and 2) change in defect width as a describing parameter of periodontal healing in infrabony defects treated by regenerative therapy after 6 and 24 months. In 24 patients with advanced periodontitis, 39 infrabony defects were treated by guided tissue regeneration (GTR) using expanded polytetrafluoroethylene (ePTFE) (n = 7) or bioabsorbable barriers (n = 32). Clinical parameters were assessed and 39 standardized radiographs (in triplicate) were taken before and 6 and 24 months after surgery. Using a computer-assisted analysis, the depth, width, and angle of the bony defects were measured. Statistically significant vertical clinical attachment gains (CAL-V: 3.15 +/- 1.63 mm to 3.31 +/- 1.65 mm; P<0.001) and bony fill (1.30 +/- 2.53 mm; P<0.01 to 1.54 +/- 2.70 mm; P<0.005) were observed 6 and 24 months postsurgically. In a multilevel regression analysis CAL-V gain was predicted by baseline CAL-V (P <0.0001), actual smoking (P <0.05), and age (P <0.1). Bony fill could be predicted by baseline height of the infrabony component (P<0.0001), gingival index at baseline (P<0.05), and actual smoking (P <0.01). In narrow (<26 degrees) and deep (> or = 3 mm) infrabony defects bony fill was more pronounced than in wide and shallow defects (P <0.05). Improvement achieved by guided tissue regeneration in infrabony defects can be maintained up to 24 months after surgery. Narrow and deep infrabony defects respond radiographically and to some extent clinically more favorably to GTR therapy than wide and shallow defects. However, depth of the infrabony component was a stronger prognostic parameter than defect angle. Actual smoking impairs the results of GTR therapy in infrabony defects.

  3. Multiscale simulations of defect dipole-enhanced electromechanical coupling at dilute defect concentrations

    NASA Astrophysics Data System (ADS)

    Liu, Shi; Cohen, R. E.

    2017-08-01

    The role of defects in solids of mixed ionic-covalent bonds such as ferroelectric oxides is complex. Current understanding of defects on ferroelectric properties at the single-defect level remains mostly at the empirical level, and the detailed atomistic mechanisms for many defect-mediated polarization-switching processes have not been convincingly revealed quantum mechanically. We simulate the polarization-electric field (P-E) and strain-electric field (ɛ-E) hysteresis loops for BaTiO3 in the presence of generic defect dipoles with large-scale molecular dynamics and provide a detailed atomistic picture of the defect dipole-enhanced electromechanical coupling. We develop a general first-principles-based atomistic model, enabling a quantitative understanding of the relationship between macroscopic ferroelectric properties and dipolar impurities of different orientations, concentrations, and dipole moments. We find that the collective orientation of dipolar defects relative to the external field is the key microscopic structure feature that strongly affects materials hardening/softening and electromechanical coupling. We show that a small concentration (≈0.1 at. %) of defect dipoles dramatically improves electromechanical responses. This offers the opportunity to improve the performance of inexpensive polycrystalline ferroelectric ceramics through defect dipole engineering for a range of applications including piezoelectric sensors, actuators, and transducers.

  4. Comparison of defects identified through Minnesota's Birth Defects Information System And Vital Records, 2006-2008.

    PubMed

    Banerjee, Emily; Zabel, Erik; Alexander, Bruce

    2012-01-01

    The purpose of this study was to examine the differences in birth defects identified through passive and active surveillance systems in Hennepin and Ramsey counties in Minnesota, 2006-2008. This was done by comparing birth defects identified on birth certificates through the Minnesota Department of Health's Office of the State Registrar's Birth and Death Registry (vital records) with those identified by the Minnesota Department of Health's Birth Defects Information System (BDIS), an active birth defects surveillance system. The study population included 73,059 babies born to residents of Hennepin and Ramsey counties. There were 1,882 babies that either vital records and/or BDIS identified as having 1 or more birth defects. Cases identified by BDIS were then linked with matching birth certificates found in the vital records database. Using BDIS as the gold standard, it was observed that the vital records database had an overall underreporting rate of 89% when all broad groups of defects were compared, and 72% when 11 specific defects tracked by both registries were compared. The sensitivity and positive predictive values of vital records to identify cases were also compared using BDIS as the gold standard, and demonstrated low sensitivities for most of the 11 comparable defects (range: 0% for tracheoesophageal fistula to 80% for anencephalus). These observations indicate that BDIS has significantly improved the quality of birth defects surveillance in Minnesota.

  5. Entanglement entropy in integrable field theories with line defects. Part I. Topological defect

    NASA Astrophysics Data System (ADS)

    Jiang, Yunfeng

    2017-07-01

    In this paper and a companion one [1], we study the effect of integrable line defects on entanglement entropy in massive integrable field theories in 1+1 dimensions. The current paper focuses on topological defects that are purely transmissive. Using the form factor bootstrap method, we show that topological defects do not affect the the entanglement entropy in the UV limit and modify slightly the leading exponential correction in the IR. This conclusion holds for both unitary and non-unitary field theories. In contrast, non-topological defects affect the entanglement entropy more significantly both in UV and IR limit and will be studied in the companion paper.

  6. Automated defect review of the wafer bevel with a defect review scanning electron microscope

    NASA Astrophysics Data System (ADS)

    McGarvey, Steve; Kanezawa, Masakazu

    2009-03-01

    One of the few remaining bastions of non-regulated Integrated Circuit defectivity is the wafer bevel. Recent internal Integrated Circuit Manufacturing studies have suggested that the edge bevel may be responsible for as much as a two to three percent yield loss during a defect excursion on the manufacturing line and a one to two percent yield loss during ongoing wafer manufacturing. A new generation of defect inspection equipment has been introduced to the Research and Development, Integrated Circuit, MEM's and Si wafer manufacturing markets that has imparted the ability for the end equipment user to detect defects located on the bevel of the wafer. The inherent weakness of the current batch of wafer bevel inspection equipment is the lack of automatic discrete defect classification data into multiple, significant classification bins and the lack of discrete elemental analysis data. Root cause analysis is based on minimal discrete defect analysis as a surrogate for a statistically valid sampling of defects from the bevel. This paper provides a study of the methods employed with a Hitachi RS-5500EQEQ Defect Review Scanning Electron Microscope (DRSEM) to automatically capture high resolution/high magnification images and collect elemental analysis on a statistically valid sample of the discrete defects that were located by a bevel inspection system.

  7. Multiscale crystal defect dynamics: A coarse-grained lattice defect model based on crystal microstructure

    NASA Astrophysics Data System (ADS)

    Lyu, Dandan; Li, Shaofan

    2017-10-01

    Crystal defects have microstructure, and this microstructure should be related to the microstructure of the original crystal. Hence each type of crystals may have similar defects due to the same failure mechanism originated from the same microstructure, if they are under the same loading conditions. In this work, we propose a multiscale crystal defect dynamics (MCDD) model that models defects by considering its intrinsic microstructure derived from the microstructure or material genome of the original perfect crystal. The main novelties of present work are: (1) the discrete exterior calculus and algebraic topology theory are used to construct a scale-up (coarse-grained) dual lattice model for crystal defects, which may represent all possible defect modes inside a crystal; (2) a higher order Cauchy-Born rule (up to the fourth order) is adopted to construct atomistic-informed constitutive relations for various defect process zones, and (3) an hierarchical strain gradient theory based finite element formulation is developed to support an hierarchical multiscale cohesive (process) zone model for various defects in a unified formulation. The efficiency of MCDD computational algorithm allows us to simulate dynamic defect evolution at large scale while taking into account atomistic interaction. The MCDD model has been validated by comparing of the results of MCDD simulations with that of molecular dynamics (MD) in the cases of nanoindentation and uniaxial tension. Numerical simulations have shown that MCDD model can predict dislocation nucleation induced instability and inelastic deformation, and thus it may provide an alternative solution to study crystal plasticity.

  8. Automated Heuristic Defect Classification (AHDC) for haze-induced defect growth management and mask requalification

    NASA Astrophysics Data System (ADS)

    Munir, Saghir; Qidwai, Gul

    2012-03-01

    This article presents results from a heuristic automated defect classification algorithm for reticle inspection that mimics the classification rules. AHDC does not require CAD data, thus it can be rapidly deployed in a high volume production environment without the need for extensive design data management. To ensure classification consistency a software framework tracks every defect in repeated inspections. Through its various image based derived metrics it is shown that such a system manages and tracks repeated defects in applications such as haze induced defect growth.

  9. Nonequilibrium occupancy of tail states and defects in a-Si:H: Implications for defect structure

    NASA Astrophysics Data System (ADS)

    Schumm, G.; Jackson, W. B.; Street, R. A.

    1993-11-01

    A detailed investigation of the electron and hole occupancy of tail states in undoped amorphous silicon (a-Si:H) as well as changes in the dangling-bond occupancy as a function of excitation intensity was carried out using light-induced electron-spin-resonance (LESR) measurements. For very thick films the band-tail electron and hole densities are not proportional. Over a wide range of excitation conditions the excess hole density is constant, suggesting the presence of charged defects with a density that is 5-10 times larger than the neutral defect density in annealed or as-grown a-Si:H. Light soaking increases mainly the neutral defect density. The dependence of the excess hole density on film thickness and absorption profiles indicates that this effect is a bulk property, which may be masked in thinner films by the comparatively high interface defect density. Model calculations of nonequilibrium occupation statistics confirm the experimental results. For a defect distribution that includes charged defects, the calculations suggest a very small positive LESR signature of the dangling bond, in spite of the high density of charged defects in the material, as a necessary consequence of the asymmetries observed between electron and hole capture rates and tail-state distributions. The calculations demonstrate that the lack of this signature does not imply a defect structure that contains predominantly neutral defects.

  10. USE OF BIOCERAMICS IN FILLING BONE DEFECTS

    PubMed Central

    Garrido, Carlos Antõnio; Sampaio, Tania Clarete Fonseca Vieira Sales

    2015-01-01

    Objective: To present the results from using biological ceramics for filling bone defects resulting from post-traumatic or orthopedic injuries. Methods: Thirty-six patients with bone defects caused by trauma or orthopedic injury were evaluated. Nineteen patients were male (52.8%) and 17 were female (47.2%). Their ages ranged from 19 to 84 years, with a mean of 45.7 years and median of 37 years. Only patients with defects that required at least five grams of biological ceramic were included. Eighteen cases were classified as orthopedic: bone defects were observed in 11 cases of total hip arthroplasty; one case of primary total hip arthroplasty, due to coxarthrosis; five cases of femoral or tibial open wedge osteotomy; and one case of tarsal arthrodesis. There were 18 cases of trauma-related defects; uninfected pseudarthrosis, eight cases; recent fractures of the tibial plateau with compression of the spongy bone, three cases; and exposed fractures treated with external fixators, seven cases. The surgical technique consisted of curetting and debriding the injury until bone suitable for grafting was found. Biological ceramic was then used to fill the defect and some kind of fixation was applied. Results: Among the 36 patients evaluated, it was seen that 35 (97.2%) presented integration of the biological ceramic, while one case of open fracture treated with external fixation had poor integration of the biological ceramic. Conclusion: Treatment of bone defects of orthopedic or post-traumatic etiology using a phosphocalcium ceramic composed of hydroxyapatite was shown to be a practical, effective and safe method. PMID:27022576

  11. Point-defect-mediated dehydrogenation of alane

    NASA Astrophysics Data System (ADS)

    Ismer, Lars

    2011-03-01

    For the engineering of better hydrogen storage materials a systematic understanding of their hydrogen sorption kinetics is crucial. Theoretical studies on metal hydrides have indicated that in many cases point defects control mass transport and hence hydrogen uptake and release. Manipulating point-defect concentrations thus allows control over hydrogen sorption kinetics, opening up new engineering strategies. However, in some cases the relevance of kinetic limitations due to point defects is still under debate; kinetic inhibition of hydrogen sorption has also been attributed to surface effects, e.g. oxide layers or low recombination rates. We present a systematic analysis of the dehydrogenation kinetics of alane (AlH3), one of the prime candidate materials for hydrogen storage. Using hybrid-density functional calculations we determine the concentrations and mobilities of point defects and their complexes. Kinetic Monte Carlo simulations are used to describe the full dehydrogenation reaction. We show that under dehydrogenation conditions charged hydrogen vacancy defects form in the crystal, which have a strong tendency towards clustering. The vacancy clusters denote local nuclei of Al phase, and the growth of these nuclei eventually drives the AlH3/Al transformation. However, the low concentration of vacancy defects limits the transport of hydrogen across the bulk, and hence acts as the rate-limiting part of the process. The dehydrogenation is therefore essentially inactive at room temperature, explaining why AlH3 is metastable for years, even though it is thermodynamically unstable. Our derived activation energy and dehydrogenation curves are in excellent agreement with the experimental data, providing evidence for the relevance of bulk point-defect kinetics. Work performed in collaboration with A. Janotti and C. G. Van de Walle, and supported by DOE.

  12. [Prenatal diagnosis of abdominal wall defects].

    PubMed

    El Mhabrech, H; Ben Hmida, H; Charfi, H; Zrig, A; Hafsa, C

    2017-09-07

    Anterior abdominal wall defects (AAWD) correspond to a wide spectrum of congenital defects affecting 6.3/10,000 pregnancies. They have in common a closure defect of the anterior abdominal wall and can be fatal or expose the fetus and the neonate (NN) to many complications. This study was based on a retrospective study of 22 cases of AAWD collected between May 2009 and December 2014. Its purpose was to specify the importance of prenatal ultrasonography in the diagnosis and prognosis assessment of these defects. These 22 AAWDs consisted in 13 cases of omphalocele (including four cases of Beckwith-Wiedemann syndrome), four of gastroschisis, one of pentalogy of Cantrell, three of vesical exstrophy and one of cloacal exstrophy. Prenatal ultrasonography provided the diagnosis of 14 of these defects with a changing sensitivity with the gestational age varying from 17% in the first trimester to 71.4% and 77.8% in the second and third trimesters, respectively. The relevance of this examination was improved when performed by an imaging specialist. The prenatal diagnosis of these defects indicated an amniocentesis in eight cases, allowing the diagnosis of two cases of trisomy 18. It also motivated a therapeutic termination of the pregnancy (TTP) in ten cases. Prenatal ultrasonography allowed better prenatal follow-up and planning of the delivery of the continued pregnancies. It indicated an emergency C-section in only one case by showing intestinal complications of gastroschisis. Four NNs died (two cases of omphalocele and two of gastroschisis), three of which postoperatively and the prenatal diagnosis did not improve survival. Prenatal ultrasonographic diagnosis provided a precise morphological study determining the type of the AAWD, a complete malformation assessment, and the prognosis factors. This resulted in adequate multidisciplinary pre and postnatal care, including a rigorous ultrasound follow-up, a TTP in case of associated defects, and emergency delivery once the

  13. Two-dimensional defect modes in optically induced photonic lattices

    SciTech Connect

    Wang Jiandong; Yang Jianke; Chen Zhigang

    2007-07-15

    In this article, localized linear defect modes due to band gap guidance in two-dimensional photonic lattices with localized or nonlocalized defects are investigated theoretically. First, when the defect is localized and weak, eigenvalues of defect modes bifurcated from edges of Bloch bands are derived analytically. It is shown that in an attractive (repulsive) defect, defect modes bifurcate out from Bloch-band edges with normal (anomalous) diffraction coefficients. Furthermore, distances between defect-mode eigenvalues and Bloch-band edges decrease exponentially with the defect strength, which is very different from the one-dimensional case where such distances decrease quadratically with the defect strength. It is also found that some defect-mode branches bifurcate not from Bloch-band edges, but from quasiedge points within Bloch bands, which is very unusual. Second, when the defect is localized but strong, defect modes are determined numerically. It is shown that both the repulsive and attractive defects can support various types of defect modes such as fundamental, dipole, quadrupole, and vortex modes. These modes reside in various band gaps of the photonic lattice. As the defect strength increases, defect modes move from lower band gaps to higher ones when the defect is repulsive, but remain within each band gap when the defect is attractive, similar to the one-dimensional case. The same phenomena are observed when the defect is held fixed while the applied dc field (which controls the lattice potential) increases. Lastly, if the defect is nonlocalized (i.e., it persists at large distances in the lattice), it is shown that defect modes can be embedded inside the continuous spectrum, and they can bifurcate out from edges of the continuous spectrum algebraically rather than exponentially.

  14. Hardwood log defect photographic database, software and user's guide

    Treesearch

    R. Edward Thomas

    2009-01-01

    Computer software and user's guide for Hardwood Log Defect Photographic Database. The database contains photographs and information on external hardwood log defects and the corresponding internal characteristics. This database allows users to search for specific defect types, sizes, and locations by tree species. For every defect, the database contains photos of...

  15. Decision making in reconstruction of defects of the eyelid.

    PubMed

    Ferguson, Noor M; Mathijssen, Irene M J; Hofer, Stefan O P; Mureau, Marc A M

    2011-02-01

    We present three patients with major defects of the eyelid who subsequently had them reconstructed. They included a defect of the lateral upper lid, a defect of the medial upper and lower lids, and a defect of the medial lower lid, cheek, and nose.

  16. Efficient Co-Replication of Defective Novirhabdovirus

    PubMed Central

    Rouxel, Ronan N.; Mérour, Emilie; Biacchesi, Stéphane; Brémont, Michel

    2016-01-01

    We have generated defective Viral Hemorrhagic Septicemia Viruses (VHSV) which express either the green fluorescent protein (GFP) or a far-red fluorescent protein (mKate) by replacing the genes encoding the nucleoprotein N or the polymerase-associated P protein. To recover viable defective viruses, rVHSV-ΔN-Red and rVHSV-ΔP-Green, fish cells were co-transfected with both deleted cDNA VHSV genomes, together with plasmids expressing N, P and L of the RNA-dependent RNA polymerase. After one passage of the transfected cell supernatant, red and green cell foci were observed. Viral titer reached 107 PFU/mL after three passages. Infected cells were always red and green with the very rare event of single red or green cell foci appearing. To clarify our understanding of how such defective viruses could be so efficiently propagated, we investigated whether (i) a recombination event between both defective genomes had occurred, (ii) whether both genomes were co-encapsidated in a single viral particle, and (iii) whether both defective viruses were always replicated together through a complementation phenomenon or even as conglomerate. To address these hypotheses, genome and viral particles have been fully characterized and, thus, allowing us to conclude that rVHSV-ΔN-Red and rVHSV-ΔP-Green are independent viral particles which could propagate only by simultaneously infecting the same cells. PMID:26959049

  17. High purith low defect FZ silicon

    NASA Technical Reports Server (NTRS)

    Kimura, H.; Robertson, G.

    1985-01-01

    The most common intrinsic defects in dislocation-free float zone (FZ) silicon crystals are the A- and B-type swirl defects. The mechanisms of their formation and annihilation have been extensively studied. Another type of defect in dislocation-free FZ crystals is referred to as a D-type defect. Concentrations of these defects can be minimized by optimizing the growth conditions, and the residual swirls can be reduced by the post-growth extrinsic gettering process. Czochralski (Cz) silicon wafers are known to exhibit higher resistance to slip and warpage due to thermal stress than do FZ wafers. The Cz crystals containing dislocations are more resistant to dislocation movement than dislocated FZ crystals because of the locking of dislocations by oxygen atoms present in the Cz crystals. Recently a transverse magnetic field was applied during the FZ growth of extrinsic silicon. Resultant flow patterns, as revealed by striation etching and spreading resistance in Ga-doped silicon crystals, indicate strong effects of the transverse magnetic field on the circulation within the melt. At fields of 5500 gauss, the fluid flow in the melt volume is so altered as to affect the morphology of the growing crystal.

  18. Coating defect evaluation based on stimulated thermography

    NASA Astrophysics Data System (ADS)

    Palumbo, Davide; Tamborrino, Rosanna; Galietti, Umberto

    2017-05-01

    Thermal Barrier Coatings are used to protect the materials from severe temperature and chemical environments. In particular, these materials are used in the engineering fields where high temperatures, corrosive environments and high mechanical stress are required. Defects present between substrate material and coating, as detachments may cause the break of coating and the consequent possibility to exposure the substrate material to the environment conditions. The capability to detect the defect zones with non-destructive techniques could allow the maintenance of coated components with great advantages in terms of costs and prediction of fatigue life. In this work, two different heat sources and two different thermographic techniques have been used to detect the adhesion defects among the base material and the coating. Moreover, an empirical thermographic method has been developed to evaluate the thickness of the thermal coating and to discriminate between an unevenness of the thickness and a defect zone. The study has been conducted on circular steel specimens with simulated adhesion defect and on specimens prepared with different thicknesses of thermal barrier coating.

  19. Ultrasonic NDE Simulation for Composite Manufacturing Defects

    NASA Technical Reports Server (NTRS)

    Leckey, Cara A. C.; Juarez, Peter D.

    2016-01-01

    The increased use of composites in aerospace components is expected to continue into the future. The large scale use of composites in aerospace necessitates the development of composite-appropriate nondestructive evaluation (NDE) methods to quantitatively characterize defects in as-manufactured parts and damage incurred during or post manufacturing. Ultrasonic techniques are one of the most common approaches for defect/damage detection in composite materials. One key technical challenge area included in NASA's Advanced Composite's Project is to develop optimized rapid inspection methods for composite materials. Common manufacturing defects in carbon fiber reinforced polymer (CFRP) composites include fiber waviness (in-plane and out-of-plane), porosity, and disbonds; among others. This paper is an overview of ongoing work to develop ultrasonic wavefield based methods for characterizing manufacturing waviness defects. The paper describes the development and implementation of a custom ultrasound simulation tool that is used to model ultrasonic wave interaction with in-plane fiber waviness (also known as marcelling). Wavefield data processing methods are applied to the simulation data to explore possible routes for quantitative defect characterization.

  20. Congenital defects of the pericardium: a review.

    PubMed

    Shah, Ankit B; Kronzon, Itzhak

    2015-08-01

    Pericardial defects are a rare disorder that can be characterized as acquired or congenital. Congenital defects can be further characterized by location and size of the defect, e.g. left- or right-sided and partial or complete absence of the pericardium. While physical examination and electrocardiogram are not diagnostic, chest radiographs and echocardiography have findings that should alert the clinician to the absence of the pericardium as a possible diagnosis. Despite its limitations with visualizing the normal pericardium in areas of minimal adipose, cardiac magnetic resonance is currently the gold standard for diagnosing the congenital absence of the pericardium. Patients have a similar life expectancy to those without pericardial defects; however in certain cases, herniation and strangulation of cardiac chambers can be life threatening and lead to sudden cardiac death. Treatment is tailored to the patient's symptoms, presentation, and the size and location of the defect. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  1. Imprinting defects on human chromosome 15.

    PubMed

    Horsthemke, B; Buiting, K

    2006-01-01

    The Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are two distinct neurogenetic diseases that are caused by the loss of function of imprinted genes on the proximal long arm of human chromosome 15. In a few percent of patients with PWS and AS, the disease is due to aberrant imprinting and gene silencing. In patients with PWS and an imprinting defect, the paternal chromosome carries a maternal imprint. In patients with AS and an imprinting defect, the maternal chromosome carries a paternal imprint. Imprinting defects offer a unique opportunity to identify some of the factors and mechanisms involved in imprint erasure, resetting and maintenance. In approximately 10% of cases the imprinting defects are caused by a microdeletion affecting the 5' end of the SNURF-SNRPN locus. These deletions define the 15q imprinting center (IC), which regulates imprinting in the whole domain. These findings have been confirmed and extended in knock-out and transgenic mice. In the majority of patients with an imprinting defect, the incorrect imprint has arisen without a DNA sequence change, possibly as the result of stochastic errors of the imprinting process or the effect of exogenous factors.

  2. Developmental defects of enamel in phenylketonuria patients.

    PubMed

    de Marco Salvadori, Carina; Pereira, Rosana Marques; Raichert, Caroline; de Morais Ferreira, Fernanda; de Menezes, José Vitor Nogara Borges

    2014-01-01

    The purpose of this study was to determine the prevalence of developmental defects of enamel in patients diagnosed with phenylketonuria (PKU). The study group consisted of 24 four- to 24-year-old subjects with PKU. The control group consisted of 24 healthy individuals. An examination for the detection of developmental defects of enamel was conducted at the university pediatric dentistry clinic by a single examiner. Data were analyzed using the chi-square test (P<.05) and odds ratios. The prevalence of developmental defects of enamel was 36 percent in the study group and 15 percent in the control group. The maxillary central incisors were the most affected teeth in patients with PKU, while the maxillary and mandibular first molars were the most affected teeth in the control group. Patients with PKU had a 3.3-fold greater chance of exhibiting developmental defects of enamel versus the healthy controls, which was statistically significant (P<.001). The study findings suggest that PKU increases the risk of developmental defects of enamel.

  3. Structure Defect Property Relationships in Binary Intermetallics

    NASA Astrophysics Data System (ADS)

    Medasani, Bharat; Ding, Hong; Chen, Wei; Persson, Kristin; Canning, Andrew; Haranczyk, Maciej; Asta, Mark

    2015-03-01

    Ordered intermetallics are light weight materials with technologically useful high temperature properties such as creep resistance. Knowledge of constitutional and thermal defects is required to understand these properties. Vacancies and antisites are the dominant defects in the intermetallics and their concentrations and formation enthalpies could be computed by using first principles density functional theory and thermodynamic formalisms such as dilute solution method. Previously many properties of the intermetallics such as melting temperatures and formation enthalpies were statistically analyzed for large number of intermetallics using structure maps and data mining approaches. We undertook a similar exercise to establish the dependence of the defect properties in binary intermetallics on the underlying structural and chemical composition. For more than 200 binary intermetallics comprising of AB, AB2 and AB3 structures, we computed the concentrations and formation enthalpies of vacancies and antisites in a small range of stoichiometries deviating from ideal stoichiometry. The calculated defect properties were datamined to gain predictive capabilities of defect properties as well as to classify the intermetallics for their suitability in high-T applications. Supported by the US DOE under Contract No. DEAC02-05CH11231 under the Materials Project Center grant (Award No. EDCBEE).

  4. Robust detection of defects in imaging arrays

    NASA Astrophysics Data System (ADS)

    Dudas, Jozsef; Jung, Cory; Chapman, Glenn H.; Koren, Zahava; Koren, Israel

    2006-01-01

    As digital imagers continue to increase in size and pixel density, the detection of faults in the field becomes critical to delivering high quality output. Traditional schemes for defect detection utilize specialized hardware at the time of manufacture and are impractical for use in the field, while previously proposed software-based approaches tend to lead to quality-degrading false positive diagnoses. This paper presents an algorithm that utilizes statistical information extracted from a sequence of normally captured images to identify the location and type of defective pixels. Building on previous research, this algorithm utilizes data local to each pixel and Bayesian statistics to more accurately infer the likelihood of each defect, which successfully improves the detection time. Several defect types are considered, including pixels with one-half of the typical sensitivity and permanently stuck pixels. Monte Carlo simulations have shown that for defect densities of up to 0.5%, 50 ordinary images are sufficient to accurately identify all faults without falsely diagnosing good pixels as faulty. Testing also indicates that the algorithm can be extended to higher resolution imagers and to those with noisy stuck pixels, with only minimal cost to performance.

  5. Role of point defects/defect complexes in silicon device processing. Book of abstracts, fourth workshop

    SciTech Connect

    Not Available

    1994-06-01

    The 41 abstracts are arranged into 6 sessions: impurities and defects in commercial substrates: their sources, effects on material yield, and material quality; impurity gettering in silicon: limits and manufacturability of impurity gettering and in silicon solar cells; impurity/defect passivation; new concepts in silicon growth: improved initial quality and thin films; and silicon solar cell design opportunities.

  6. Radiographic parameters for prognosis of periodontal healing of infrabony defects: two different definitions of defect depth.

    PubMed

    Eickholz, Peter; Hörr, Torten; Klein, Filip; Hassfeld, Stefan; Kim, Ti-Sun

    2004-03-01

    The aim of the present study was to evaluate defect width and two different definitions of defect depth as prognostic factors of periodontal healing in infrabony defects treated by regenerative therapy 6 and 24 months after surgery. In 32 patients with moderate to advanced periodontitis, 50 infrabony defects were treated by the guided tissue regeneration (GTR) technique using non-resorbable or bioabsorbable barriers. Clinical parameters were assessed, and 50 triplets of standardized radiographs were taken before surgery and 6 and 24 months after surgery. Using a computer-assisted analysis, the distances cemento-enamel junction (CEJ) to alveolar crest (AC), CEJ to bony defect (BD), horizontal projection of the most coronal extension of the bony wall to the root surface to BD, width, and angle of the bony defects were measured. Depth of the bony defect was 1) calculated as CEJ-BD minus CEJ-AC (INFRA1) and 2) measured as horizontal projection of the most coronal extension of the bony wall to the root surface to BD (INFRA2). Whereas statistically significant vertical clinical attachment level gains (CAL-V: 3.36 +/- 1.59 mm/ 3.41 +/- 1.72 mm; P < 0.001) could be found both 6 and 24 months after surgery, bony fill (0.70 +/- 2.52 mm; P = 0.056/1.21 +/- 2.55 mm; P < 0.005) was significant 24 months post-surgically only. In a multilevel regression analysis, CAL-V gain was predicted by bioabsorbable membrane (P = 0.005), baseline probing depths (PD) (P < 0.001), and actual smoking (P < 0.05). Bony fill could be predicted by baseline depth of the infrabony component as determined by INFRA2 (P < 0.05), angulation of bony defect (P < 0.005), and gingival index at baseline (P < 0.001). In narrow (< 37 degrees) and deep (> or = 4 mm) infrabony defects, bony fill was more pronounced than in wide and shallow defects (P < 0.001). Improvement achieved by GTR in infrabony defects can be maintained up to 24 months after surgery. Narrow and deep infrabony defects respond

  7. Determining the critical size of EUV mask substrate defects

    SciTech Connect

    Goldberg, Kenneth A.; Gullikson, Eric M.; Han, Hakseung; Cho, Wonil; Jeon, Chan-Uk; Wurm, Stefan

    2008-05-26

    Determining the printability of substrate defects beneath the extreme ultraviolet (EUV) reflecting multilayer stack is an important issue in EUVL lithography. Several simulation studies have been performed in the past to determine the tolerable defect size on EUV mask blank substrates but the industry still has no exact specification based on real printability tests. Therefore, it is imperative to experimentally determine the printability of small defects on a mask blanks that are caused by substrate defects using direct printing of programmed substrate defect in an EUV exposure tools. SEMATECH fabricated bump type program defect masks using standard electron beam lithography and performed printing tests with the masks using an EUV exposure tool. Defect images were also captured using SEMATECH's Berkeley Actinic Imaging Tool in order to compare aerial defect images with secondary electron microscope images from exposed wafers. In this paper, a comprehensive understanding of substrate defect printability will be presented and printability specifications of EUV mask substrate defects will be discussed.

  8. Determining the Critcial Size of EUV Mask Substrate Defects

    SciTech Connect

    Mccall, Monnikue M; Han, Hakseung; Cho, Wonil; Goldberg, Kenneth; Gullikson, Eric; Jeon, Chan-Uk; Wurm, Stefan

    2008-02-28

    Determining the printability of substrate defects beneath the extreme ultraviolet (EUV) reflecting multilayer stack is an important issue in EUVL lithography. Several simulation studies have been performed in the past to determine the tolerable defect size on EUV mask blank substrates but the industry still has no exact specification based on real printability tests. Therefore, it is imperative to experimentally determine the printability of small defects on a mask blanks that are caused by substrate defects using direct printing of programmed substrate defect in an EUV exposure tool. SEMATECH fabricated bump type program defect masks using standard electron beam lithography and performed printing tests with the masks using an EUV exposure tool. Defect images were also captured using SEMATECH's Berkeley Actinic Imaging Tool in order to compare aerial defect images with secondary electron microscope images from exposed wafers. In this paper, a comprehensive understanding of substrate defect printability will be presented and printability specifications of EUV mask substrate defects will be discussed.

  9. A practical approach for modeling EUVL mask defects

    SciTech Connect

    Gullikson, E.M.; Cerjan, C.; Stearns, D.J.; Mirkarimi, P.B.; Sweeney, D.W.

    2001-06-01

    An approximate method is proposed to calculate the EUV scattering from a defect within a multilayer coating. In this single surface approximation (SSA) the defective multilayer structure is replaced by a single reflecting surface with the shape of the top surface of the multilayer. The range of validity of this approximation has been investigated for Gaussian line defects using 2D finite-difference-time-domain simulations. The SSA is found to be valid for sufficiently low aspect ratio defects such as those expected for the critical defects nucleated by particles on the mask substrate. The critical EUVL defect size is calculated by combining the SSA with a multilayer growth model and aerial image simulations. Another approximate method for calculating the aerial image of an unresolved defect is also discussed. Although the critical substrate defects may be larger than the resolution of higher NA cameras, the point defect approximation provides a useful framework for understanding the printability of a wide range of defects.

  10. Reconstructive periodontal therapy with simultaneous ridge augmentation. A clinical and histological case series report

    PubMed Central

    Windisch, Péter; Szendrői-Kiss, Dóra; Horváth, Attila; Suba, Zsuzsanna; Gera, István

    2008-01-01

    Treatment of intrabony periodontal defects with a combination of a natural bone mineral (NBM) and guided tissue regeneration (GTR) has been shown to promote periodontal regeneration in intrabony defects. In certain clinical situations, the teeth presenting intrabony defects are located at close vicinity of the resorbed alveolar ridge. In these particular cases, it is of clinical interest to simultaneously reconstruct both the intrabony periodontal defect and the resorbed alveolar ridge, thus allowing insertion of endosseous dental implants. The aim of the present study was to present the clinical and histological results obtained with a new surgical technique designed to simultaneously reconstruct the intrabony defect and the adjacently located resorbed alveolar ridge. Eight patients with chronic advanced periodontitis displaying intrabony defects located in the close vicinity of resorbed alveolar ridges were consecutively enrolled in the study. After local anesthesia, mucoperiosteal flaps were raised, the granulation tissue removed, and the roots meticulously scaled and planed. A subepithelial connective tissue graft was harvested from the palate and sutured to the oral flap. The intrabony defect and the adjacent alveolar ridge were filled with a NBM and subsequently covered with a bioresorbable collagen membrane (GTR). At 11–20 months (mean, 13.9 ± 3.9 months) after surgery, implants were placed, core biopsies retrieved, and histologically evaluated. Mean pocket depth reduction measured 3.8 ± 1.7 mm and mean clinical attachment level gain 4.3 ± 2.2 mm, respectively. Reentry revealed in all cases a complete fill of the intrabony component and a mean additional vertical hard tissue gain of 1.8 ± 1.8 mm. The histologic evaluation indicated that most NBM particles were surrounded by bone. Mean new bone and mean graft area measured 17.8 ± 2.8% and 32.1 ± 8.3%, respectively. Within their limits, the present findings indicate that

  11. Maternal autoimmune disease and birth defects in the National Birth Defects Prevention Study.

    PubMed

    Howley, Meredith M; Browne, Marilyn L; Van Zutphen, Alissa R; Richardson, Sandra D; Blossom, Sarah J; Broussard, Cheryl S; Carmichael, Suzan L; Druschel, Charlotte M

    2016-11-01

    Little is known about the association between maternal autoimmune disease or its treatment and the risk of birth defects. We examined these associations using data from the National Birth Defects Prevention Study, a multi-site, population-based, case-control study. Analyses included 25,116 case and 9897 unaffected control infants with estimated delivery dates between 1997 and 2009. Information on autoimmune disease, medication use, and other pregnancy exposures was collected by means of telephone interview. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for birth defects with five or more exposed cases; crude ORs and exact 95% CIs were estimated for birth defects with three to four exposed cases. Autoimmune disease was reported by 373 mothers (279 case and 94 control mothers). The majority of birth defects evaluated were not associated with autoimmune disease; however, a statistically significant association between maternal autoimmune disease and encephalocele was observed (OR, 4.64; 95% CI, 1.95-11.04). Eighty-two mothers with autoimmune disease used an immune modifying/suppressing medication during pregnancy; this was associated with encephalocele (OR, 7.26; 95% CI, 1.37-24.61) and atrial septal defects (OR, 3.01; 95% CI, 1.16-7.80). Our findings suggest maternal autoimmune disease and treatment are not associated with the majority of birth defects, but may be associated with some defects, particularly encephalocele. Given the low prevalence of individual autoimmune diseases and the rare use of specific medications, we were unable to examine associations of specific autoimmune diseases and medications with birth defects. Other studies are needed to confirm these findings. Birth Defects Research (Part A) 106:950-962, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Birth defects in pregestational diabetes: Defect range, glycemic threshold and pathogenesis.

    PubMed

    Gabbay-Benziv, Rinat; Reece, E Albert; Wang, Fang; Yang, Peixin

    2015-04-15

    Currently, 60 million women of reproductive age (18-44 years old) worldwide, and approximately 3 million American women have diabetes mellitus, and it has been estimated that this number will double by 2030. Pregestational diabetes mellitus (PGD) is a significant public health problem that increases the risk for structural birth defects affecting both maternal and neonatal pregnancy outcome. The most common types of human structural birth defects associated with PGD are congenital heart defects and central nervous system defects. However, diabetes can induce birth defects in any other fetal organ. In general, the rate of birth defects increases linearly with the degree of maternal hyperglycemia, which is the major factor that mediates teratogenicity of PGD. Stringent prenatal care and glycemic control are effective means to reduce birth defects in PGD pregnancies, but cannot reduce the incidence of birth defects to the rate of that is seen in the nondiabetic population. Studies in animal models have revealed that PGD induces oxidative stress, which activates cellular stress signalling leading to dysregulation of gene expression and excess apoptosis in the target organs, including the neural tube and embryonic heart. Activation of the apoptosis signal-regulating kinase 1 (ASK1)-forkhead transcription factor 3a (FoxO3a)-caspase 8 pathway causes apoptosis in the developing neural tube leading to neural tube defects (NTDs). ASK1 activates the c-Jun-N-Terminal kinase 1/2 (JNK1/2), which leads to activation of the unfolded protein response and endoplasmic reticulum (ER) stress. Deletion of the ASK1 gene, the JNK1 gene, or the JNK2 gene, or inhibition of ER stress by 4-Phenylbutyric acid abrogates diabetes-induced apoptosis and reduces the formation of NTDs. Antioxidants, such as thioredoxin, which inhibits the ASK1-FoxO3a-caspase 8 pathway or ER stress inhibitors, may prevent PGD-induced birth defects.

  13. Point defect reduction in wide bandgap semiconductors by defect quasi Fermi level control

    NASA Astrophysics Data System (ADS)

    Reddy, P.; Hoffmann, M. P.; Kaess, F.; Bryan, Z.; Bryan, I.; Bobea, M.; Klump, A.; Tweedie, J.; Kirste, R.; Mita, S.; Gerhold, M.; Collazo, R.; Sitar, Z.

    2016-11-01

    A theoretical framework for a general approach to reduce point defect density in materials via control of defect quasi Fermi level (dQFL) is presented. The control of dQFL is achieved via excess minority carrier generation. General guidelines for controlling dQFL that lead to a significant reduction in compensating point defects in any doped material is proposed. The framework introduces and incorporates the effects of various factors that control the efficacy of the defect reduction process such as defect level, defect formation energy, bandgap, and excess minority carrier density. Modified formation energy diagrams are proposed, which illustrate the effect of the quasi Fermi level control on the defect formation energies. These formation energy diagrams provide powerful tools to determine the feasibility and requirements to produce the desired reduction in specified point defects. An experimental study of the effect of excess minority carriers on point defect incorporation in GaN and AlGaN shows an excellent quantitative agreement with the theoretical predictions. Illumination at energies larger than the bandgap is employed as a means to generate excess minority carriers. The case studies with CN in Si doped GaN, H and VN in Mg doped GaN and VM-2ON in Si doped Al0.65Ga0.35N revealed a significant reduction in impurities in agreement with the proposed theory. Since compensating point defects control the material performance (this is particularly challenging in wide and ultra wide bandgap materials), dQFL control is a highly promising technique with wide scope and may be utilized to improve the properties of various materials systems and performance of devices based upon them.

  14. Preliminary work on the quantum defect measurements

    NASA Astrophysics Data System (ADS)

    Hutcherson, Lindsay; Sanders, Justin; Han, Jianing

    2016-05-01

    Van der Waals interactions are generally studied in physics, chemistry, biology, and other fields of science. In order to fine-tune van der Waals interactions, the atomic energy levels need to be known very accurately. That is, we must accurately determine the quantum defects. Quantum defects of 85Rb have been recently measured, and the quantum defects of 87Rb have also been measured for nS and nD states with the resolution of 1 MHz. this experiment will focus on the P, F, and G states, which are higher angular momentum states and more sensitive to electric fields. These states are crucial for collisions, which may lead to some of the interesting phenomena in ultracold atoms, such as ultracold plasma. In this presentation, a progress report will be given on this project. The authors would like to acknowledge the travel Grants from DDOE and the University of South Alabama.

  15. Defects and degeneracies in supersymmetry protected phases

    NASA Astrophysics Data System (ADS)

    Fokkema, Thessa; Schoutens, Kareljan

    2015-08-01

    We analyse a class of 1D lattice models, known as \\text{M}k models, which are characterised by an order-k clustering of spin-less fermions and by N}=2 lattice supersymmetry. Our main result is the identification of a class of (bulk or edge) defects, that are in one-to-one correspondence with so-called spin fields in a corresponding {Z}k parafermion CFT. In the gapped regime, injecting such defects leads to ground-state degeneracies that are protected by the supersymmetry. The defects, which are closely analogous to quasi-holes over the fermonic Read-Rezayi quantum Hall states, display characteristic fusion rules, which are of Ising type for k = 2 and of Fibonacci type for k = 3.

  16. Congenital varicella associated with multiple defects

    PubMed Central

    McKendry, J. B. J.; Bailey, J. D.

    1973-01-01

    Only two previous reports in the medical literature record the association of multiple congenital defects in the baby and varicella in the mother during the first trimester of pregnancy. The case is reported of a female infant born to a mother who contracted varicella in the 11th week of pregnancy. The infant was premature, small for dates, and had skin and localized muscular defects and respiratory difficulty. Subsequently she was found to be retarded. She failed to thrive and was subject to frequent infections. Further investigation revealed a unilateral diaphragmatic weakness, scoliosis and abnormalities of the ocular fundi. Several non-febrile seizures occurred. A pneumoencephalogram revealed dilated ventricles. She died at 20 months of age following a seizure. Consideration of maternal infections, especially viral, occurring early in pregnancy, augmented by antibody studies in the newborn and mother should be part of the investigation of multiple congenital defects in the newborn. PMID:4682642

  17. Ribosome defects in disorders of erythropoiesis.

    PubMed

    Narla, Anupama; Hurst, Slater N; Ebert, Benjamin L

    2011-02-01

    Over the past decade, genetic lesions that cause ribosome dysfunction have been identified in both congenital and acquired human disorders. These discoveries have established a new category of disorders, known as ribosomopathies, in which the primary pathophysiology is related to impaired ribosome function. The protoptypical disorders are Diamond-Blackfan anemia, a congenital bone marrow failure syndrome, and the 5q- syndrome, a subtype of myelodysplastic syndrome. In both of these disorders, impaired ribosome function causes a severe macrocytic anemia. In this review, we will discuss the evidence that defects in ribosomal biogenesis cause the hematologic phenotype of Diamond-Blackfan anemia and the 5q- syndrome. We will also explore the potential mechanisms by which a ribosomal defect, which would be expected to have widespread consequences, may lead to specific defects in erythropoiesis.

  18. Osteochondral defects in the ankle: why painful?

    PubMed Central

    Reilingh, Mikel L.; Zengerink, Maartje; van Bergen, Christiaan J. A.

    2010-01-01

    Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage. PMID:20151110

  19. Global defect topology in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Machon, Thomas; Alexander, Gareth P.

    2016-07-01

    We give the global homotopy classification of nematic textures for a general domain with weak anchoring boundary conditions and arbitrary defect set in terms of twisted cohomology, and give an explicit computation for the case of knotted and linked defects in R3, showing that the distinct homotopy classes have a 1-1 correspondence with the first homology group of the branched double cover, branched over the disclination loops. We show further that the subset of those classes corresponding to elements of order 2 in this group has representatives that are planar and characterize the obstruction for other classes in terms of merons. The planar textures are a feature of the global defect topology that is not reflected in any local characterization. Finally, we describe how the global classification relates to recent experiments on nematic droplets and how elements of order 4 relate to the presence of τ lines in cholesterics.

  20. Osteochondral defects in the ankle: why painful?

    PubMed

    van Dijk, C Niek; Reilingh, Mikel L; Zengerink, Maartje; van Bergen, Christiaan J A

    2010-05-01

    Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage.

  1. Defect engineering of ZnO

    NASA Astrophysics Data System (ADS)

    Weber, M. H.; Selim, F. A.; Solodovnikov, D.; Lynn, K. G.

    2008-10-01

    The defect responsible for the transparent to red color change of nominally undoped ZnO bulk single crystals is investigated. Upon annealing in the presence of metallic Zn as reported by Halliburton et al. and also Ti and Zr a native defect forms with an energy level about 0.7 eV below the conduction band. This change is reversible upon annealing in oxygen. Optical transmission data along with positron depth profiles and annealing studies are combined to identify the defect as oxygen vacancies. Vacancy clustering occurs at about 500 °C if isolated zinc and oxygen vacancies. In the absence of zinc vacancies, clusters form at about 800 °C.

  2. Interaction between water and defective silica surfaces

    SciTech Connect

    Chen Yunwen; Cheng Haiping

    2011-03-21

    We use the density functional theory method to study dry (1 x 1) {alpha}-quartz (0001) surfaces that have Frenkel-like defects such as oxygen vacancy and oxygen displacement. These defects have distinctively different effects on the water-silica interface depending on whether the adsorbent is a single water molecule, a cluster, or a thin film. The adsorption energies, bonding energies, and charge transfer or redistributions are analyzed, from which we find that the existence of a defect enhances the water molecule and cluster surface interaction by a large amount, but has little or even negative effect on water thin film-silica surface interaction. The origin of the weakening in film-surface systems is the collective hydrogen bonding that compromises the water-surface interaction in the process of optimizing the total energy. For clusters on surfaces, the lowest total energy states lower both the bonding energy and the adsorption energy.

  3. Global defect topology in nematic liquid crystals

    PubMed Central

    Machon, Thomas

    2016-01-01

    We give the global homotopy classification of nematic textures for a general domain with weak anchoring boundary conditions and arbitrary defect set in terms of twisted cohomology, and give an explicit computation for the case of knotted and linked defects in R3, showing that the distinct homotopy classes have a 1–1 correspondence with the first homology group of the branched double cover, branched over the disclination loops. We show further that the subset of those classes corresponding to elements of order 2 in this group has representatives that are planar and characterize the obstruction for other classes in terms of merons. The planar textures are a feature of the global defect topology that is not reflected in any local characterization. Finally, we describe how the global classification relates to recent experiments on nematic droplets and how elements of order 4 relate to the presence of τ lines in cholesterics. PMID:27493576

  4. Structural control design and defective systems

    NASA Astrophysics Data System (ADS)

    Gattulli, Vincenzo; Potenza, Francesco

    2016-05-01

    The intersection between the two concepts of structural control and defectiveness is discussed. Two simple oscillators differently connected by serial spring-dashpot arrangement are used to simply simulate technically relevant cases: dissipatively coupled adjacent free-standing structures, structures equipped by TMD and base-isolated structures. Eigensolution loci of the two classes of systems are tracked against one or more significant parameters to determine the potential benefits realized by different combinations of stiffness and viscosity. In both studied cases, codimension-two manifolds in the four-parameter space corresponding to coalescing eigenvalues are determined by analytical expressions. Conditions to discern semi-simple eigenvalues from defective ones confirm that the latter is the generic case laying in a two-parameter space while the former span a one-parameter subspace. The knowledge of the location of the defective systems in the parameter space permits to determine regions with specific dynamical properties useful for control design purpose.

  5. Quantitative defect characterization via guided waves

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoliang

    Pipeline inspection systems are being developed to locate critical defects, and more recently to characterize and size them efficiently in order to prevent potential leakage or catastrophic failure, as well as to assist in the decision process of wait or replace. Ultrasonic guided waves have demonstrated their abilities and advantages of detecting a variety of defect types that occur in a plate or hollow cylindrical structure compared to other conventional methods. Yet defect classification and sizing in these structures by guided waves is still a major issue. In this work, the Boundary Element Method (BEM) combined with the guided wave normal mode expansion technique is used to study the interaction of various guided wave packets of energy with various crack and corrosion boundaries in a structure. Attempts are made to find the best modes and frequency with the best chance of success in carrying out the defect classification and sizing process. To simplify the problem, a plate model is used to approximate the wall structure of a hollow cylinder of large diameter-to-wall-thickness ratio. The dispersion relation and wave structures of Shear Horizontal (SH) waves along the circumference of a hollow cylinder is derived and calculated. A parametric study with the hollow cylinder wall thickness to diameter ratio is conducted. Together with similar studies on circumferential Lamb waves in a pipe wall, a quantitative criterion as when a hollow cylinder wall can indeed be treated as a plate is given. A two-dimensional boundary element method (BEM) FORTRAN code was developed for surface breaking defect characterization and sizing in a plate using guided waves. A new code is developed for internal inclusion types of defect that are considered benign to see whether they will give false alarms. Parametric studies on different incident wave modes and frequencies establish a guideline on how to characterize a defect in a two-dimensional wave guide. In reality, all defects are

  6. [Nonoperative management of rotator cuff defects].

    PubMed

    Heers, H; Heers, G

    2007-09-01

    Rotator cuff defects are common disorders of the shoulder. Although the outcome of surgical treatment of rotator cuff tears is well documented in the literature, less is known about the efficacy of physical therapy for symptomatic rotator cuff tears. Clear therapeutic standards are still missing. This article presents the nonoperative treatment options as well as a literature review. The results of most studies show that patients with rotator cuff defects do benefit from both physical therapy and simple home exercises independent from the size of the defect. However, due to the heterogeneity of outcome measures used, it is difficult to compare the results published. There is still a need for well-planned randomised controlled studies investigating the efficacy of exercise in the management of rotator cuff tears.

  7. Partial atrioventricular canal defect in a dog.

    PubMed

    Santamarina, G; Espino, L; Vila, M; Suarez, M L

    2002-01-01

    A case of a partial atrial canal defect is described in a nine-month-old female English setter. The patient had a large ostium primum atrial septal defect and a concurrent malformation of the mitral valve. Electrocardiographic and radiographic findings were suggestive of marked enlargement of the right heart and pulmonary overcirculation. Definitive diagnosis and assessment of the haemodynamic consequences were made using echocardiography. The magnitude of the left-to-right intracardiac shunt was estimated by measuring the pulmonary to systemic flow ratio (Qp/Qs) from Doppler-derived pulmonary and aortic blood flow. The results of this report suggest that dogs with a partial atrioventricular canal defect and concurrent mild mitral regurgitation may exhibit no clinical signs during the first years of life, even in cases with a Qp/Qs ratio of greater than 2.

  8. Trapping of drops by wetting defects

    PubMed Central

    't Mannetje, Dieter; Ghosh, Somnath; Lagraauw, Rudy; Otten, Simon; Pit, Arjen; Berendsen, Christian; Zeegers, Jos; van den Ende, Dirk; Mugele, Frieder

    2014-01-01

    Controlling the motion of drops on solid surfaces is crucial in many natural phenomena and technological processes including the collection and removal of rain drops, cleaning technology and heat exchangers. Topographic and chemical heterogeneities on solid surfaces give rise to pinning forces that can capture and steer drops in desired directions. Here we determine general physical conditions required for capturing sliding drops on an inclined plane that is equipped with electrically tunable wetting defects. By mapping the drop dynamics on the one-dimensional motion of a point mass, we demonstrate that the trapping process is controlled by two dimensionless parameters, the trapping strength measured in units of the driving force and the ratio between a viscous and an inertial time scale. Complementary experiments involving superhydrophobic surfaces with wetting defects demonstrate the general applicability of the concept. Moreover, we show that electrically tunable defects can be used to guide sliding drops along actively switchable tracks—with potential applications in microfluidics. PMID:24721935

  9. Laterality defects in the national birth defects prevention study 1998-2007 birth prevalence and descriptive epidemiology

    USDA-ARS?s Scientific Manuscript database

    Little is known epidemiologically about laterality defects. Using data from the National Birth Defects Prevention Study (NBDPS), a large multi-site case-control study of birth defects, we analyzed prevalence and selected characteristics in children born with laterality defects born from 1998 to 2007...

  10. Air pollution and congenital heart defects.

    PubMed

    Agay-Shay, Keren; Friger, Michael; Linn, Shai; Peled, Ammatzia; Amitai, Yona; Peretz, Chava

    2013-07-01

    Environmental factors such as ambient air pollution have been associated with congenital heart defects. The aim of this study was to investigate the association between gestational exposure to air pollution and the risk of congenital heart defects. We conducted a registry-based cohort study with a total of 135,527 live- and still-births in the Tel-Aviv region during 2000-2006. We used a Geographic Information System-based spatiotemporal approach with weekly inverse distance weighting modeling to evaluate associations between gestational exposure to ambient air pollution during weeks 3-8 of pregnancy and the risk for congenital heart defects. The following pollutants were studied: carbon monoxide, nitrogen-dioxide, ozone, sulfur-dioxide and particulate matter with aerodynamic diameter smaller than 10 μm and 2.5 μm (PM10, PM2.5 respectively). Logistic models, adjusted for socio-demographic covariates were used to evaluate the associations. We found that maternal exposure to increased concentrations of PM10 was associated with multiple congenital heart defects (adjusted OR 1.05, 95% CI: 1.01 to 1.10 for 10 μg/m(3) increment). An inverse association was observed between concentrations of PM2.5 and isolated patent ductus arteriosus (adjusted OR 0.78, 95% CI: 0.68 to 0.91 for 5 µg/m(3) increment). Sensitivity analyses showed that results were consistent. Generally there were no evidence for an association between gaseous air pollutants and congenital heart defects.Our results for PM10 and congenital heart defects confirm results from previous studies. The results for PM2.5 need further investigations.

  11. Trisomy 18 and neural tube defects.

    PubMed

    Rosa, Rafael Fabiano Machado; Trevisan, Patrícia; Rosa, Rosana Cardoso Manique; Lorenzen, Marina Boff; Zen, Paulo Ricardo Gazzola; Oliveira, Ceres Andréia; Graziadio, Carla; Paskulin, Giorgio Adriano

    2013-09-01

    Trisomy 18 or Edwards syndrome is a chromosomal abnormality characterized by a broad clinical picture and a limited survival. More than 130 different abnormalities have been described in these patients-among them are neural tube defects. We verified the frequency and types of major neural tube defects observed among patients with trisomy 18. Our sample consisted of consecutive patients evaluated by a clinical genetics service of a referral hospital in southern Brazil between 1975 and 2008. Fisher's exact test (two-tailed) and chi-square test with Yates' correction were used to compare frequencies (P < 0.05 values were considered as significant). During the period of evaluation, we identified 50 patients with trisomy 18; 33 (66%) were female and age at the first evaluation ranged from 1 day to 16 years (median 14 days). One cell line with full trisomy 18 was the predominant cytogenetic finding (90%). Three patients (6%) had major neural tube defects, all females. These were two patients (4%) with encephaloceles and one (2%) with myelomeningocele. This last patient undergo to correction surgery on her first day of life. Our data, in accordance with the literature, support the idea that the presence of neural tube defects among patients with trisomy 18 is not coincidental (i.e., these defects are actually part of the spectrum of abnormalities presented in trisomy 18). Thus, the diagnosis of trisomy 18 should be considered in children with major neural tube defects, especially in the presence of other abnormalities or dysmorphisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Defects in Carbon-Based Materials

    NASA Astrophysics Data System (ADS)

    Duscher, Gerd

    2013-03-01

    Two distinctly different carbon based semiconducting materials were investigated as to how point defects can influence the electric properties. SiC is a high power electronic material with high bulk mobility. The interface between SiC and SiO2 is generally considered to be the cause for the reduced mobility of SiC devices compared to bulk SiC. We investigated this interface with atomic resolution Z-contrast and electron energy-loss spectroscopy. We come to the conclusion that the previously observed interface layer is due to the miscut and does not exhibit any stoichiometric change. The structure of the interface which is limiting the device performance is caused by the steps and facets at the interface introduced by the miscut. We observed a high number of carbon in the oxide right next to the interface. Aberration corrected transmission electron microscopy enabled the investigation of the atomic structure of this highly stepped interface and the impact of geometry and chemistry on the electronic properties of this material. Graphene is an emerging electronic material also with high mobility. We investigated the defects and dopants in graphene were investigated. We observed point and extended defects in this 2D material. Due to the clear observation of all atoms involved, this material can serve as a model material to study point defects directly. We observe a electronegativity doping of substitutional Si. We observed a remarkable resistance to oxidation of a variety of point defects of elements that readily oxidize in normal circumstances. Boron and nitrogen doped graphene was investigated and the exact nature of the dopant sites and interactions will be shown. Generally speaking modern electron microscopy can directly visualize the full atomic structures in geometrically simple materials like graphene. The knowledge of point defects can be the basis to understand the electronic property structure relationship of structurally complex materials like SiC.

  13. Public Perception of Birth Defects Terminology

    PubMed Central

    Mai, Cara T.; Petersen, Emily E.; Miller, Assia

    2015-01-01

    BACKGROUND ‘Birth defect’ is a common phrase, yet concerns have been expressed that the word ‘defect’ carries a negative connotation. Our objective was to examine public perceptions of terms used to refer to birth defects. METHODS Four questions about terminology of birth defects were included in the U.S. nationally representative 2007 HealthStyles survey. Respondents answered questions about whether they or a family member were affected by birth defects (condition status), and which terms used to refer to birth defects they found preferable and which offensive. We further examined whether condition status, race/ethnicity, gender, income, geographical region, and education level impacted respondents’ term selection. Chi-square tests and multinomial logistic regression were performed using SAS 9.1. RESULTS ‘Birth defects’ was most frequently selected as the first choice preferred term (35.4%), followed by 21.9% who selected ‘children with special needs.’ For respondents who said they themselves or a family member were affected by birth defects (11.5%), their responses differed statistically (p ≤ 0.0001) from nonaffected respondents, but the leading choices were still ‘birth defects’ (28.5%) and ‘children with special needs’ (27.2%). Condition status, race/ethnicity, gender, income, and education level were all significant predictors of the respondents’ choice of a preferred term. When asked which phrases might be offensive, the top choices were ‘none of the phrases listed’ (37.0%), ‘adverse pregnancy outcomes’ (23.1%), and ‘birth defects’ (21.4%). CONCLUSIONS ‘Birth defect’ was the preferred term; however, survey participants affected by birth defects responded less positively to the term. Continued dialogue about accepted and appropriate terminology is necessary. PMID:23015510

  14. Defect reduction methodologies for damascene interconnect process development

    NASA Astrophysics Data System (ADS)

    Skumanich, Andrew; Cai, Man-Ping

    1999-08-01

    A critical aspect of interconnect process development is identifying and eliminating yield impacting defects. A methodology is described which has been implemented at Applied Materials to utilize wafer metrology tools to drive process development for advanced interconnect fabrication. The methodology is based on a patterned wafer inspection tool, the WF736Duo, combined with a high throughput defect- review SEM with automatic defect classification, the SEMVision. This combination is tools facilitates defect sourcing and elimination. The requirements for defect reduction are increased since defects can result from both the levels and the interaction between levels. A full-flow Cu damascene interconnect process is examined from oxide deposition to final electrical test to establish inspection strategies for defect reduction. The inspection points for optimal defect reduction are identified based on e-test determination of yield limiting defects. The WF736 was utilized to capture a wide range of defects at the various processing steps. The progression of the defects is tracked to the final e-test point. This tracking both establishes the key defect types and facilitates defect sourcing. Further, the unique ability of the WF736 to segregate defects during the inspection with no loss in throughput, along with the SEMVision ADC analysis, allowed for faster defect sourcing.

  15. Interaction between a drifting spiral and defects

    SciTech Connect

    Zou, X.; Levine, H. ); Kessler, D.A. )

    1993-02-01

    Spiral waves, a type of reentrant excitation,'' are believed to be associated with the most dangerous cardiac arrhythmias, including ventricular tachycardia and fibrillation. Recent experimental findings have implicated defective regions as a means of trapping spirals which would otherwise drift and (eventually) disappear. Here, we model the myocardium as a simple excitable medium and study via simulation the interaction between a drifting spiral and one or more such defects. We interpret our results in terms of a criterion for the transition between trapped and untrapped drifting spirals.

  16. Intersecting surface defects and instanton partition functions

    DOE PAGES

    Pan, Yiwen; Peelaers, Wolfger

    2017-07-14

    We analyze intersecting surface defects inserted in interacting four-dimensional N = 2 supersymmetric quantum field theories. We employ the realization of a class of such systems as the infrared xed points of renormalization group flows from larger theories, triggered by perturbed Seiberg-Witten monopole-like con gurations, to compute their partition functions. These results are cast into the form of a partition function of 4d/2d/0d coupled systems. In conclusion, our computations provide concrete expressions for the instanton partition function in the presence of intersecting defects and we study the corresponding ADHM model.

  17. Dirac oscillator interacting with a topological defect

    SciTech Connect

    Carvalho, J.; Furtado, C.; Moraes, F.

    2011-09-15

    In this work we study the interaction problem of a Dirac oscillator with gravitational fields produced by topological defects. The energy levels of the relativistic oscillator in the cosmic string and in the cosmic dislocation space-times are sensible to curvature and torsion associated to these defects and are important evidence of the influence of the topology on this system. In the presence of a localized magnetic field the energy levels acquire a term associated with the Aharonov-Bohm effect. We obtain the eigenfunctions and eigenvalues and see that in the nonrelativistic limit some results known in standard quantum mechanics are reached.

  18. Automatic leather inspection of defective patterns

    NASA Astrophysics Data System (ADS)

    Tafuri, Maria; Branca, Antonella; Attolico, Giovanni; Distante, Arcangelo; Delaney, William

    1996-02-01

    Constant and consistent quality levels in the manufacturing industry increasingly require automatic inspection. This paper describes a vision system for leather inspection based upon visual textural properties of the material surface. As visual appearances of both leather and defects exhibit a wide range of variations due to original skin characteristics, curing processes and defect causes, location and classification of defective areas become hard tasks. This paper describes a method for separating the oriented structures of defects from normal leather, a background not homogeneous in color, thickness, brightness and finally in wrinkledness. The first step requires the evaluation of the orientation field from the image of the leather. Such a field associates to each point of the image a 2D vector having as direction the dominant local orientation of gradient vectors and the length proportional to their coherence evaluated in a neighborhood of fixed size. The second step analyzes such a vector flow field by projecting it on a set of basis vectors (elementary texture vectors) spanning the vector space where the vector fields associated to the defects can be defined. The coefficients of these projections are the parameters by means of which both detection and classification can be performed. Since the set of basis vectors is neither orthogonal nor complete, the projection requires the definition of a global optimization criteria that has been chosen to be the minimum difference between the original flow field and the vector field obtained as a linear combination of the basis vectors using the estimated coefficients. This optimization step is performed through a neural network initialized to recognize a limited number of patterns (corresponding to the basis vectors). This second step estimates the parameter vector in each point of the original image. Both leather without defects and defects can be characterized in terms of coefficient vectors making it possible to

  19. Role of defective icosahedra in undercooled copper

    NASA Astrophysics Data System (ADS)

    Celino, Massimo; Rosato, Vittorio; di Cicco, Andrea; Trapananti, Angela; Massobrio, Carlo

    2007-05-01

    We elucidate the role played by defective icosahedra on the stability of undercooled copper by using molecular-dynamics simulations. Our approach is substantiated by the level of agreement with experiments on a variety of structural properties. We show that not only perfect but also defective icosahedra, embedded in a disordered matrix, lower the local cohesive energy. This has the effect of stabilizing the liquid structure against crystallization. Our work rationalizes experimental findings by identifying the nature of those icosahedral subunits that contribute to the stability of the undercooled liquid.

  20. Intersecting surface defects and instanton partition functions

    NASA Astrophysics Data System (ADS)

    Pan, Yiwen; Peelaers, Wolfger

    2017-07-01

    We analyze intersecting surface defects inserted in interacting four-dimensional N=2 supersymmetric quantum field theories. We employ the realization of a class of such systems as the infrared fixed points of renormalization group flows from larger theories, triggered by perturbed Seiberg-Witten monopole-like configurations, to compute their partition functions. These results are cast into the form of a partition function of 4d/2d/0d coupled systems. Our computations provide concrete expressions for the instanton partition function in the presence of intersecting defects and we study the corresponding ADHM model.

  1. Domain walls and defects in ferroelectric materials

    NASA Astrophysics Data System (ADS)

    Rojac, Tadej; Damjanovic, Dragan

    2017-10-01

    The results of recent studies of domain walls and their interaction with defects in BaTiO3, Pb(Zr,Ti)O3, and BiFeO3 are discussed. The studies reveal why donor- and acceptor-doped Pb(Zr,Ti)O3 behave differently, what is the role of stationary charged domain walls in enhanced properties of domain engineered BaTiO3 crystals, and give evidence of a large concentration of specific charged point defects within domain walls in BiFeO3 ceramics.

  2. GaN: Defect and Device Issues

    SciTech Connect

    Pearton, S.J.; Ren, F.; Shul, R.J.; Zolper, J.C.

    1998-11-09

    The role of extended and point defects, and key impurities such as C, O and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

  3. Maximizing results in reconstruction of cheek defects.

    PubMed

    Mureau, Marc A M; Hofer, Stefan O P

    2009-07-01

    The face is exceedingly important, as it is the medium through which individuals interact with the rest of society. Reconstruction of cheek defects after trauma or surgery is a continuing challenge for surgeons who wish to reliably restore facial function and appearance. Important in aesthetic facial reconstruction are the aesthetic unit principles, by which the face can be divided in central facial units (nose, lips, eyelids) and peripheral facial units (cheeks, forehead, chin). This article summarizes established options for reconstruction of cheek defects and provides an overview of several modifications as well as tips and tricks to avoid complications and maximize aesthetic results.

  4. Letting defective babies die: who decides?

    PubMed

    Ellis, T S

    1982-01-01

    This article explores who, in the first instance, should decide whether to withhold or withdraw treatment from a defective newborn. The Article begins by defining the term "severely defective newborn" and discussing potential sources of liability for persons who decide to withhold or withdraw treatment. It next analyzes the ability of parents, physicians, and courts to make these treatment decisions. The Article concludes that, although parents and physicians may eventually make the specific determination, the legislature should at least set guidelines so that the decisions will be, in some measure, consistent, predictable, adequately informed, and in accord with community values.

  5. Defect dynamics in crystalline buckled membranes

    NASA Astrophysics Data System (ADS)

    Pezzutti, Aldo D.; Vega, Daniel A.

    2011-07-01

    We study the dynamics of defect annihilation in flexible crystalline membranes suffering a symmetry-breaking phase transition. The kinetic process leading the system toward equilibrium is described through a Brazovskii-Helfrich-Canham Hamiltonian. In membranes, a negative disclination has a larger energy than a positive disclination. Here we show that this energetic asymmetry does not only affect equilibrium properties, like the Kosterlitz-Thouless transition temperature, but also plays a fundamental role in the dynamic of defects. Both unbinding of dislocations and Carraro-Nelson “antiferromagnetic” interactions between disclinations slow down the dynamics below the Lifshitz-Safran regime observed in flat hexagonal systems.

  6. Defect Detection Using a Scanning Laser Source

    NASA Astrophysics Data System (ADS)

    Burrows, S. E.; Dixon, S.

    2011-06-01

    Surface breaking defects are identified using a scanning laser source. A Q-switched Nd-YAG laser is used as a non-contact source of ultrasound and an electromagnetic acoustic transducer (EMAT) employed as detector. For a thin plate, an increase in frequency content of the received wave is observed when the laser spot is situated directly over the defect. Time-frequency analysis using a Wigner transform has enabled individual Lamb wave modes to be identified, while propagation of Lamb waves through aluminium sheet is studied by finite element analysis.

  7. Counting defects in an instantaneous quench.

    PubMed

    Ibaceta, D; Calzetta, E

    1999-09-01

    We consider the formation of defects in a nonequilibrium second-order phase transition induced by an instantaneous quench to zero temperature in a type II superconductor. We perform a full nonlinear simulation where we follow the evolution in time of the local order parameter field. We determine how far into the phase transition theoretical estimates of the defect density based on the Gaussian approximation yield a reliable prediction for the actual density. We also characterize quantitatively some aspects of the out of equilibrium phase transition.

  8. Toward defect guard-banding of EUV exposures by full chip optical wafer inspection of EUV mask defect adders

    NASA Astrophysics Data System (ADS)

    Halle, Scott D.; Meli, Luciana; Delancey, Robert; Vemareddy, Kaushik; Crispo, Gary; Bonam, Ravi; Burkhardt, Martin; Corliss, Daniel

    2015-03-01

    The detection of EUV mask adder defects has been investigated with an optical wafer defect inspection system employing a methodology termed Die-to-"golden" Virtual Reference Die (D2VRD). Both opaque and clear type mask absorber programmed defects were inspected and characterized over a range of defect sizes, down to (4x mask) 40 nm. The D2VRD inspection system was capable of identifying the corresponding wafer print defects down to the limit of the defect printability threshold at approximately 30 nm (1x wafer). The efficacy of the D2VRD scheme on full chip wafer inspection to suppress random process defects and identify real mask defects is demonstrated. Using defect repeater analysis and patch image classification of both the reference die and the scanned die enables the unambiguous identification of mask adder defects.

  9. The hematopoietic defect in PNH is not due to defective stroma, but is due to defective progenitor cells.

    PubMed

    Nishimura, Jun-ichi; Ware, Russell E; Burnette, Angela; Pendleton, Andrew L; Kitano, Kiyoshi; Hirota, Toshiyuki; Machii, Takashi; Kitani, Teruo; Smith, Clay A; Rosse, Wendell F

    2002-01-01

    Although paroxysmal nocturnal hemoglobinuria (PNH) is often associated with aplastic anemia (AA), the nature of the pathogenetic link between PNH and AA remains unclear. Moreover, the PIG-A mutation appears to be necessary but not sufficient for the development of PNH, suggesting other factors are involved. The ability of PNH marrow cells to form in vitro hematopoietic colonies and the ability of PNH marrow to generate stroma that could support hematopoiesis of normal or PNH marrow in cross culture were investigated. PNH marrow from both post-Ficoll and post-lineage depleted hematopoietic progenitor cells grew similarly significantly fewer colonies than normal marrow. Sorting of CD59(+) and CD59(-) CD34(+) CD38(-) cells from patients with PNH showed similarly impaired clonogenic efficiency, indicating that the hematopoietic defect in PNH does not directly relate to GPI-anchored protein expression. PNH marrow readily grew stroma similar to marrow from normal donors. Cross culture experiments revealed that PNH stroma appears to function normally in vitro; it can support growth of normal marrow cells as well as normal stroma does, but neither PNH nor normal stroma could support the growth of PNH marrow cells. The hematopoietic defect in PNH is not due to defective stroma, but is due to defective progenitor cell growth related to additional unknown factors.

  10. Construction of Radial Defect Models in Rabbits to Determine the Critical Size Defects

    PubMed Central

    Zhang, Xin-Chao; Gui, Ke-Ke; Xiong, Min; Yin, Wang-Ping; Yuan, Feng-Lai; Cai, Guo-Ping

    2016-01-01

    Many studies aimed at investigating bone repair have been conducted through animal models in recent years. However, limitations do exist in these models due to varying regeneration potential among different animal species. Even using the same animal, big differences exist in the size of critical size defects (CSD) involving the same region. This study aimed to investigate the standardization of radial bone defect models in rabbits and further establish more reliable CSD data. A total of 40 6-month-old New Zealand white rabbits of clean grade totaling 80 radial bones were prepared for bone defect models, according to the principle of randomization. Five different sizes (1.0, 1.2, 1.4, 1.7 and 2.0 cm) of complete periosteal defects were introduced under anesthesia. At 12 weeks postoperatively, with the gradual increase in defect size, the grades of bone growth were significantly decreased in all 5 groups. X-ray, CT scans and H&E staining of the 1.4, 1.7, and 2.0-cm groups showed lower grades of bone growth than that of the 1.0 and 1.2-cm groups respectively (P < 0.05). Using rabbit radial defect model involving 6-month-old healthy New Zealand white rabbits, this study indicates that in order to be critical sized, defects must be greater than 1.4 cm. PMID:26731011

  11. Localization of defects in wind turbine blades and defect depth estimation using infrared thermography

    NASA Astrophysics Data System (ADS)

    Manohar, Arun; Tippmann, Jeffery; Lanza di Scalea, Francesco

    2012-04-01

    Localization of defects and determination of the depth and size using Infrared Thermography is a critical problem in wind turbine blades. Infrared Thermography offers significant advantages over other Nondestructive Testing modalities due to fast, wide-area inspection capabilities. Lock-in Thermography is an ideal method for defect detection due to the presence of deep-lying defects in wind turbine blades, which otherwise go undetected. Multivariate Outlier Analysis is used in conjunction with Lock-in technique to enhance the detectability of the defect. Results are presented on defects present in a 9m CX-100 wind turbine blade that was designed by the Sandia National Laboratory. A defect depth estimation technique based on Pulsed Thermography is also presented. A 3D depth estimation model is presented which aims to address the shortcomings of the classical depth estimation methods that are primarily based on the 1D heat conduction equation. Results are presented on a stainless steel sample with flat-bottom defects at known depths. The results are in excellent agreement with the proposed theory.

  12. Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

    NASA Astrophysics Data System (ADS)

    Wen, Vincent; Huang, L. R.; Lin, C. J.; Tseng, Y. N.; Huang, W. H.; Tuo, Laurent C.; Wylie, Mark; Chen, Ellison; Wang, Elvik; Glasser, Joshua; Kelkar, Amrish; Wu, David

    2015-10-01

    Die-to-die reticle inspections are among the simplest and most sensitive reticle inspections because of the use of an identical-design neighboring-die for the reference image. However, this inspection mode can have two key disadvantages: (1) The location of the defect is indeterminate because it is unclear to the inspector whether the test or reference image is defective; and (2) nuisance and false defects from mask manufacturing noise and tool optical variation can limit the usable sensitivity. The use of a new sequencing approach for a die-to-die inspection can resolve these issues without any additional scan time, without sacrifice in sensitivity requirement, and with a manageable increase in computation load. In this paper we explore another approach for die-to-die inspections using a new method of defect processing and sequencing. Utilizing die-to-die double arbitration during defect detection has been proven through extensive testing to generate accurate placement of the defect in the correct die to ensure efficient defect disposition at the AIMS step. The use of this method maintained the required inspection sensitivity for mask quality as verified with programmed-defectmask qualification and then further validated with production masks comparing the current inspection approach to the new method. Furthermore, this approach can significantly reduce the total number of defects that need to be reviewed by essentially eliminating the nuisance and false defects that can result from a die-to-die inspection. This "double-win" will significantly reduce the effort in classifying a die-to-die inspection result and will lead to improved cycle times.

  13. Alcohol Related Birth Defects: Implications for Education.

    ERIC Educational Resources Information Center

    Lamanna, Michael

    1982-01-01

    Discusses background and nature of alcohol-related birth defects. Describes a continuum of impairment to offspring of drinking mothers that is dose-related and produces serious behavioral/learning deficits. The continuum includes young people of normal intelligence who perform below expected levels and find school adjustment difficult. Offers…

  14. Defect-free ultrahigh flux asymmetric membranes

    DOEpatents

    Pinnau, Ingo; Koros, William J.

    1990-01-01

    Defect-free, ultrahigh flux integrally-skinned asymmetric membranes having extremely thin surface layers (<0.2 .mu.m) comprised of glassy polymers are disclosed. The membranes are formed by casting an appropriate drope followed by forced convective evaporation of solvent to obtain a dry phase separated asymmetrical structure. The structure is then washed in a precipitation liquid and dried.

  15. Electrochemical Implications of Defects in Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Hall, Jonathan Peter

    The electrochemical behavior of carbon nanotubes (CNTs) containing both intrinsic and extrinsically introduced defects has been investigated through the study of bamboo and hollow multi-walled CNT morphologies. The controlled addition of argon, hydrogen, and chlorine ions in addition to atomic hydrogen and magnesium vapor was used for varying the charge and type of extrinsic defects. To quantify changes in the CNTs upon treatment, Raman spectroscopy and electrochemical techniques were employed. It was indicated from Raman spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and chronopotentiometric experiments that the electrochemical response of hollow type CNTs could be tailored more significantly compared to bamboo type CNTs, which have innately high reactive site densities and are less amenable to modification. Total defect density and edge-plane-like defect concentrations monitored through Raman spectroscopy were used to correlate changes in the electrochemical response of the CNT electrodes as a function of treatment. The implementation of CNT electrodes in a prototypical electrolytic capacitor device was then explored and characterized. Dependencies on source current and redox couple concentration were evaluated, as well as changes in the total capacitance as a function of treatment. Cyclability studies were also performed as a function of source current magnitude to evaluate the longevity of the faradaic currents which typically decrease over time in other similar capacitors. This thesis then concludes with an overall summary of the themes and findings of the research presented in this work.

  16. Surface defects and elliptic quantum groups

    NASA Astrophysics Data System (ADS)

    Yagi, Junya

    2017-06-01

    A brane construction of an integrable lattice model is proposed. The model is composed of Belavin's R-matrix, Felder's dynamical R-matrix, the Bazhanov-Sergeev-Derkachov-Spiridonov R-operator and some intertwining operators. This construction implies that a family of surface defects act on supersymmetric indices of four-dimensional \\mathcal{N} = 1supersymmetricfieldtheoriesastransfermatricesrelatedtoellipticquantumgroups.

  17. Shock-induced defects in bulk materials

    SciTech Connect

    Gray, G.T.

    1998-03-01

    In this paper examples of the shock-induced defects produced during shock compression which correlate with microstructure/mechanical property changes induced in materials due to shock prestraining are discussed. The characteristics of the shock impulse(peak shock pressure, pulse duration, and rarefaction rate) imparted to the material under investigation and the shock-induced defects produced in numerous metals and alloys are compared with their deformation behavior at ordinary rates of deformation. Examples of the range of defects observed in shock-recovered metals and alloys, include: dislocations, deformation twins, point defects, and residual metastable remnants from pressure-induced phase transformations. Results concerning the influence of interstitial content on the propensity of {omega}-phase formation and its structure in high-purity and A-7O Ti are presented. The influence of shock-wave deformation on the phase stability and substructure evolution of high-purity (low-interstitial) titanium and A-7O (3,700 ppm oxygen) titanium were probed utilizing real-time velocity interferometry (VISAR) and soft shock-recovery techniques. Suppression of the {alpha}-{omega} pressure-induced phase transformation in A-70 Ti, containing a high interstitial oxygen content, is seen to simultaneously correspond with the suppression of deformation twinning.

  18. HOW to Recognize Hazardous Defects in Trees

    Treesearch

    Minnesota Department of Natural Resources; USDA Forest Service

    1996-01-01

    Trees add to our enjoyment of outdoor experiences whether in forests, parks, or urban landscapes. Too often, we are unaware of the risks associated with defective trees, which can cause personal injury and property damage. Interest in hazard tree management has increased in recent years due to safety and liability concerns resulting from preventable accidents....

  19. Defect characterization of silicon dendritic web ribbons

    NASA Technical Reports Server (NTRS)

    Cheng, L. J.

    1985-01-01

    Progress made in the study of defect characterization of silicon dendritic web ribbon is presented. Chemical etching is used combined with optical microscopy, as well as the electron beam induced current (EBIC) technique. Thermal annealing effect on carrier lifetime is examined.

  20. Beta environmental fine structure characterization of defects

    NASA Astrophysics Data System (ADS)

    Benedek, G.; Fiorini, E.; Giuliani, A.; Milani, P.; Monfardini, A.; Nucciotti, A.; Prandoni, M. L.; Sancrotti, M.

    1999-04-01

    The fine structure of beta emission (BEFS) due to the interference with the scattered waves from neighboring atoms, analogous to EXAFS, is known to produce oscillations in the Kurie plot. Here we suggest the use of BEFS for characterizing the lattice environment of β-emitting defects located at a distance from the crystal surface not exceeding the mean free path of β-electrons. Examples of defective structures in semiconductors whose atomic arrangement could be conveniently studied with BEFS are tritium-passivated dangling bonds, β-radioactive ions implanted in the crystal lattice or segregated at extended defects such as dislocations, grain boundaries or radiation damage. Also 14C-doped diamond-like materials and other exotic carbon forms, as well as the atomic environment of ions in metal alloys could be good candidate for BEFS. In this work we have calculated the fractional BEFS modulation for 187Re in its ordinary hcp crystal lattice for which experimental data by Cosulich et al. are available. The good correspondence between theory and experiment permits to conclude that BEFS experiments at low temperature are accessible to the present bolometric detection techniques and can provide an expedient method, as compared to EXAFS, for an accurate structural assessment of extended defects in solids.

  1. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  2. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  3. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  4. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  5. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... risk of electrocution if it is long enough to become entangled in power lines and be within reach from... hazard it presents. The kite contains a design defect. (d) A power tool is not accompanied by adequate instructions and safety warnings. Reasonably foreseeable consumer use or misuse, based in part on the lack of...

  6. 16 CFR § 1115.4 - Defect.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... risk of electrocution if it is long enough to become entangled in power lines and be within reach from... hazard it presents. The kite contains a design defect. (d) A power tool is not accompanied by adequate instructions and safety warnings. Reasonably foreseeable consumer use or misuse, based in part on the lack of...

  7. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... risk of electrocution if it is long enough to become entangled in power lines and be within reach from... hazard it presents. The kite contains a design defect. (d) A power tool is not accompanied by adequate instructions and safety warnings. Reasonably foreseeable consumer use or misuse, based in part on the lack of...

  8. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... risk of electrocution if it is long enough to become entangled in power lines and be within reach from... hazard it presents. The kite contains a design defect. (d) A power tool is not accompanied by adequate instructions and safety warnings. Reasonably foreseeable consumer use or misuse, based in part on the lack of...

  9. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... risk of electrocution if it is long enough to become entangled in power lines and be within reach from... hazard it presents. The kite contains a design defect. (d) A power tool is not accompanied by adequate instructions and safety warnings. Reasonably foreseeable consumer use or misuse, based in part on the lack of...

  10. Interaction Between Topological Defects and Radiation

    NASA Astrophysics Data System (ADS)

    Romanczukiewicz, T.

    2005-12-01

    The spectral structure of linearization around soliton in the phi 4 and s-G models is presented. Negative radiation pressure in phi 4 model is discussed and analytical calculation presented in the second order. The production of topological defects forced by radiation coupled to the internal degree of freedom of soliton is studied. The fractal boundary for this creation is also described.

  11. 7 CFR 52.3761 - Defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Ripe Olives 1 Product..., blemishes, wrinkles, mutilated olives, and from any other defects which affect the appearance or edibility... ripe type or green-ripe olives which may or may not penetrate into the flesh. Olives or pieces...

  12. Ectopia cordis and other midline defects.

    PubMed

    Morales, J M; Patel, S G; Duff, J A; Villareal, R L; Simpson, J W

    2000-07-01

    Thoracic ectopia cordis and other midline defects are rare congenital anomalies that often occur with other intracardiac defects. Despite significant improvements in neonatal and infant cardiac surgeries, operations for thoracoabdominal ectopia cordis carry an extremely high mortality with only a few reported survivors of thoracic ectopia cordis. The clinical charts of 4 patients with ectopia cordis over a 6-year period were reviewed. Three of the patients showed varying degrees of Cantrell's Pentalogy; thoracic ectopia cordis was found in 1. We have reviewed our surgical strategies and reported the patients' clinical outcomes. All 4 patients are alive at follow-up. Two infants with double-outlet right ventricle have been fully corrected, and extracorporeal membrane oxygenation was necessary in 1 infant for cardiac failure following the cardiac repair. A newborn with thoracoabdominal ectopia cordis underwent primary repair of his diaphragmatic defect, and a silo was used to progressively reduce the omphalocele. He is currently awaiting elective repair of tetralogy of Fallot. Lastly, the patient with thoracic ectopia cordis underwent successful soft tissue coverage, and she is being followed in the clinic with restrictive muscular ventricular septal defects and a left ventricular diverticulum. Our experience along with other reports in the literature demonstrates that patients with thoracic and thoracoabdominal ectopia cordis can undergo and survive full cardiac, neurologic, and abdominal repair during infancy. Furthermore we advocate different approaches determined by the severity of the presentation and the presence of other complicating factors.

  13. Volterra distortions, spinning strings, and cosmic defects

    NASA Astrophysics Data System (ADS)

    Puntigam, Roland A.; Soleng, Harald H.

    1997-05-01

    Cosmic strings, as topological spacetime defects, show striking resemblance to defects in solid continua: distortions, which can be classified into disclinations and dislocations, are line-like defects characterized by a delta-function-valued curvature and torsion distribution giving rise to rotational and translational holonomy. We exploit this analogy and investigate how distortions can be adapted in a systematic manner from solid-state systems to Einstein - Cartan gravity. As distortions are efficiently described within the framework of an 0264-9381/14/5/017/img5 gauge theory of solid continua with line defects, we are led in a straightforward way to a Poincaré gauge approach to gravity which is a natural framework for introducing the notion of distorted spacetimes. Constructing all ten possible distorted spacetimes, we recover, inter alia, the well known exterior spacetime of a spin-polarized cosmic string as a special case of such a geometry. In a second step, we search for matter distributions which, in Einstein - Cartan gravity, act as sources of distorted spacetimes. The resulting solutions, appropriately matched to the distorted vacua, are cylindrically symmetric and are interpreted as spin-polarized cosmic strings and cosmic dislocations.

  14. 7 CFR 51.2659 - Condition defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Condition defects. 51.2659 Section 51.2659 Agriculture..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2659...; including, but not limited to decayed or soft cherries and such factors as pitting, shriveling, sunken areas...

  15. Oil defect detection of electrowetting display

    NASA Astrophysics Data System (ADS)

    Chiang, Hou-Chi; Tsai, Yu-Hsiang; Yan, Yung-Jhe; Huang, Ting-Wei; Mang, Ou-Yang

    2015-08-01

    In recent years, transparent display is an emerging topic in display technologies. Apply in many fields just like mobile device, shopping or advertising window, and etc. Electrowetting Display (EWD) is one kind of potential transparent display technology advantages of high transmittance, fast response time, high contrast and rich color with pigment based oil system. In mass production process of Electrowetting Display, oil defects should be found by Automated Optical Inspection (AOI) detection system. It is useful in determination of panel defects for quality control. According to the research of our group, we proposed a mechanism of AOI detection system detecting the different kinds of oil defects. This mechanism can detect different kinds of oil defect caused by oil overflow or material deteriorated after oil coating or driving. We had experiment our mechanism with a 6-inch Electrowetting Display panel from ITRI, using an Epson V750 scanner with 1200 dpi resolution. Two AOI algorithms were developed, which were high speed method and high precision method. In high precision method, oil jumping or non-recovered can be detected successfully. This mechanism of AOI detection system can be used to evaluate the oil uniformity in EWD panel process. In the future, our AOI detection system can be used in quality control of panel manufacturing for mass production.

  16. Genetics Home Reference: abdominal wall defect

    MedlinePlus

    ... Aug;6(4):232-6. Citation on PubMed Islam S. Clinical care outcomes in abdominal wall defects. Curr ... Site Map Customer Support Selection Criteria for Links USA.gov Copyright Privacy Accessibility FOIA Viewers & Players U.S. ...

  17. Computerized technique for recording board defect data

    Treesearch

    R. Bruce Anderson; R. Edward Thomas; Charles J. Gatchell; Neal D. Bennett; Neal D. Bennett

    1993-01-01

    A computerized technique for recording board defect data has been developed that is faster and more accurate than manual techniques. The lumber database generated by this technique is a necessary input to computer simulation models that estimate potential cutting yields from various lumber breakdown sequences. The technique allows collection of detailed information...

  18. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated internationally for such operations under the Radio Regulations of the International Telecommunication Union. (b) Applications for space station authority found defective under paragraph (a)(3) of this section will not be...

  19. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated internationally for such operations under the Radio Regulations of the International Telecommunication Union. (4... § 25.158. (b) Applications for space station authority found defective under paragraph (a)(3) of this...

  20. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated internationally for such operations under the Radio Regulations of the International Telecommunication Union. (b) Applications for space station authority found defective under paragraph (a)(3) of this section will not be...