Benign gastric filling defect

Energy Technology Data Exchange (ETDEWEB)

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

1979-06-15

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

Benign gastric filling defect

International Nuclear Information System (INIS)

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

1979-01-01

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

Benign gastric filling defect

Energy Technology Data Exchange (ETDEWEB)

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

1979-06-15

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

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

DEFF Research Database (Denmark)

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

1992-01-01

A study was performed to evaluate regeneration of defects in rat calvaria either unfilled or filled with a bioerodible polyorthoester only, demineralized bone only, or a composite of both. At 4 weeks, histological and radiographic studies showed that defects filled with a composite of bioerodible...... polyorthoester and demineralized bone or demineralized bone alone were bridged by bone. Unfilled defects or defects filled with polyorthoester only did not heal. The polyorthoester caused slight inflammation that subsided by 3 weeks, and only traces of the filler could be detected at 4 weeks. The polyorthoester...... provided local hemostasis when used either alone or in composites with demineralized bone. The composite implant was moldable, easily contoured, and technically easier to use than demineralized bone alone....

Bone repair by cell-seeded 3D-bioplotted composite scaffolds made of collagen treated tricalciumphosphate or tricalciumphosphate-chitosan-collagen hydrogel or PLGA in ovine critical-sized calvarial defects.

Science.gov (United States)

Haberstroh, Kathrin; Ritter, Kathrin; Kuschnierz, Jens; Bormann, Kai-Hendrik; Kaps, Christian; Carvalho, Carlos; Mülhaupt, Rolf; Sittinger, Michael; Gellrich, Nils-Claudius

2010-05-01

The aim of this study was to investigate the osteogenic effect of three different cell-seeded 3D-bioplotted scaffolds in a ovine calvarial critical-size defect model. The choice of scaffold-materials was based on their applicability for 3D-bioplotting and respective possibility to produce tailor-made scaffolds for the use in cranio-facial surgery for the replacement of complex shaped boneparts. Scaffold raw-materials are known to be osteoinductive when being cell-seeded [poly(L-lactide-co-glycolide) (PLGA)] or having components with osteoinductive properties as tricalciumphosphate (TCP) or collagen (Col) or chitosan. The scaffold-materials PLGA, TCP/Col, and HYDR (TCP/Col/chitosan) were cell-seeded with osteoblast-like cells whether gained from bone (OLB) or from periost (OLP). In a prospective and randomized design nine sheep underwent osteotomy to create four critical-sized calvarial defects. Three animals each were assigned to the HYDR-, the TCP/Col-, or the PLGA-group. In each animal, one defect was treated with a cell-free, an OLB- or OLP-seeded group-specific scaffold, respectively. The fourth defect remained untreated as control (UD). Fourteen weeks later, animals were euthanized for histo-morphometrical analysis of the defect healing. OLB- and OLP-seeded HYDR and OLB-seeded TCP/Col scaffolds significantly increased the amount of newly formed bone (NFB) at the defect bottom and OLP-seeded HYDR also within the scaffold area, whereas PLGA-scaffolds showed lower rates. The relative density of NFB was markedly higher in the HYDR/OLB group compared to the corresponding PLGA group. TCP/Col had good stiffness to prepare complex structures by bioplotting but HYDR and PLGA were very soft. HYDR showed appropriate biodegradation, TCP/Col and PLGA seemed to be nearly undegraded after 14 weeks. 3D-bioplotted, cell-seeded HYDR and TCP/Col scaffolds increased the amount of NFB within ovine critical-size calvarial defects, but stiffness, respectively, biodegradation of

Reduced CSF leak in complete calvarial reconstructions of microvascular decompression craniectomies using calcium phosphate cement.

Science.gov (United States)

Eseonu, Chikezie I; Goodwin, C Rory; Zhou, Xin; Theodros, Debebe; Bender, Matthew T; Mathios, Dimitrios; Bettegowda, Chetan; Lim, Michael

2015-12-01

Calcium phosphate cement provides a biomaterial that can be used for calvarial reconstruction in a retrosigmoid craniectomy for microvascular decompression (MVD). This study evaluates the outcomes of postoperative CSF leak and wound infection for patients undergoing a complete cranioplasty using calcium phosphate cement versus incomplete cranioplasty using polyethylene titanium mesh following a retrosigmoid craniectomy for MVD. The authors evaluated 211 cases involving patients who underwent first-time retrosigmoid craniectomies performed by a single attending surgeon fortrigeminal neuralgia from October 2008 to June 2014. From this patient population, 111 patients underwent calvarial reconstruction after retrosigmoid craniectomy using polyethylene titanium mesh, and 100 patients had reconstructions using calcium phosphate cement. A Pearson's chi-square test was used to compare postoperative complications of CSF leak and wound infection in these 2 types of cranioplasties. The polyethylene titanium mesh group included 5 patients (4.5%) with postoperative CSF leak or pseudomeningocele and 3 patients (2.7%) with wound infections. In the calcium phosphate cement group, no patients had a CSF leak, and 2 patients (2%) had wound infections. This represented a statistically significant reduction of postoperative CSF leak in patients who underwent calcium phosphate reconstructions of their calvarial defect compared with those who underwent polyethylene titanium mesh reconstructions (p = 0.03). No significant difference was seen between the 2 groups in the number of patients with postoperative wound infections. Calcium phosphate cement provides a viable alternative biomaterial for calvarial reconstruction of retrosigmoid craniectomy defects in patients who have an MVD. The application of this material provides a biocompatible barrier that reduces the incidence of postoperative CSF leaks.

Visualizing Angiogenesis by Multiphoton Microscopy In Vivo in Genetically Modified 3D-PLGA/nHAp Scaffold for Calvarial Critical Bone Defect Repair.

Science.gov (United States)

Li, Jian; Jahr, Holger; Zheng, Wei; Ren, Pei-Gen

2017-09-07

The reconstruction of critically sized bone defects remains a serious clinical problem because of poor angiogenesis within tissue-engineered scaffolds during repair, which gives rise to a lack of sufficient blood supply and causes necrosis of the new tissues. Rapid vascularization is a vital prerequisite for new tissue survival and integration with existing host tissue. The de novo generation of vasculature in scaffolds is one of the most important steps in making bone regeneration more efficient, allowing repairing tissue to grow into a scaffold. To tackle this problem, the genetic modification of a biomaterial scaffold is used to accelerate angiogenesis and osteogenesis. However, visualizing and tracking in vivo blood vessel formation in real-time and in three-dimensional (3D) scaffolds or new bone tissue is still an obstacle for bone tissue engineering. Multiphoton microscopy (MPM) is a novel bio-imaging modality that can acquire volumetric data from biological structures in a high-resolution and minimally-invasive manner. The objective of this study was to visualize angiogenesis with multiphoton microscopy in vivo in a genetically modified 3D-PLGA/nHAp scaffold for calvarial critical bone defect repair. PLGA/nHAp scaffolds were functionalized for the sustained delivery of a growth factor pdgf-b gene carrying lentiviral vectors (LV-pdgfb) in order to facilitate angiogenesis and to enhance bone regeneration. In a scaffold-implanted calvarial critical bone defect mouse model, the blood vessel areas (BVAs) in PHp scaffolds were significantly higher than in PH scaffolds. Additionally, the expression of pdgf-b and angiogenesis-related genes, vWF and VEGFR2, increased correspondingly. MicroCT analysis indicated that the new bone formation in the PHp group dramatically improved compared to the other groups. To our knowledge, this is the first time multiphoton microscopy was used in bone tissue-engineering to investigate angiogenesis in a 3D bio-degradable scaffold in

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

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Daniel H. Doro

2017-11-01

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

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

Science.gov (United States)

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

2002-04-01

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

Dural enhancement with primary calvarial lesions.

Science.gov (United States)

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

2004-11-01

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

Dural enhancement with primary calvarial lesions

Energy Technology Data Exchange (ETDEWEB)

Arana, E. [Clinica Quiron, Department of Radiology, Valencia (Spain); Marti-Bonmati, L. [Clinica Quiron, Department of Radiology, Valencia (Spain); Hospital Universitario Dr. Peset, Department of Radiology, Valencia (Spain); Ricart, V. [Hospital de la Ribera, Department of Radiology, Valencia (Spain); Perez-Ebri, M. [Hospital Universitario Dr. Peset, Department of Pathology, Valencia (Spain)

2004-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-01-15

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

Mobile myelographic filling defects: Spinal cysticercosis

Energy Technology Data Exchange (ETDEWEB)

Savoiardo, M.; Cimino, C.; Passerini, A.; La Mantia, L.

1986-03-01

Cysticercosis usually affects the brain and is easily demonstrated by CT. Spinal cysticercosis is much rarer and is usually diagnosed only at surgery. Myelographic demonstration of multiple rounded filling defects, some of which were mobile, allowed diagnosis of spinal extramedullary cysticercosis in an unsuspected case. The literature on spinal cysticercosis is briefly reviewed. Diagnosis is important in view of the recent development of medical treatment.

Assessment of bone healing ability of calcium phosphate cements loaded with platelet lysate in rat calvarial defects.

Science.gov (United States)

Babo, Pedro S; Carvalho, Pedro P; Santo, Vítor E; Faria, Susana; Gomes, Manuela E; Reis, Rui L

2016-11-01

Injectable calcium phosphate cements have been used as a valid alternative to autologous bone grafts for bone augmentation with the additional advantage of enabling minimally invasive implantation procedures and for perfectly fitting the tissue defect. Nevertheless, they have low biodegradability and lack adequate biochemical signaling to promote bone healing and remodeling. In previous in vitro studies, we observed that the incorporation of platelet lysate directly into the cement paste or loaded in hyaluronic acid microspheres allowed to modulate the cement degradation and the in vitro expression of osteogenic markers in seeded human adipose derived stem cells. The present study aimed at investigating the possible effect of this system in new bone formation when implanted in calvarial bilateral defects in rats. Different formulations were assessed, namely plain calcium phosphate cements, calcium phosphate cements loaded with human platelet lysate, hybrid injectable formulations composed of the calcium phosphate cement incorporating hyaluronin acid non-loaded microparticles (20% hyaluronin acid) or with particles loaded with platelet lysate. The degradability and new bone regrowth were evaluated in terms of mineral volume in the defect, measured by micro-computed tomography and histomorphometric analysis upon 4, 8 and 12 weeks of implantation. We observed that the incorporation of hyaluronin acid microspheres induced an overly rapid cement degradation, impairing the osteoconductive properties of the cement composites. Moreover, the incorporation of platelet lysate induced higher bone healing than the materials without platelet lysate, up to four weeks after surgery. Nevertheless, this effect was not found to be significant when compared to the one observed in the sham-treated group. © The Author(s) 2016.

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

DEFF Research Database (Denmark)

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

2007-01-01

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

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

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Philip E. Lapinski

2013-11-01

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

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

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Michael Grau

2017-12-01

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

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

Science.gov (United States)

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

2018-04-01

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

Imaging pattern of calvarial lesions in adults

Energy Technology Data Exchange (ETDEWEB)

Garfinkle, Jarred; Melancon, Denis; Cortes, Maria; Tampieri, Donatella [Montreal Neurological Institute and Hospital-McGill University Health Center, Department of Diagnostic and Interventional Neuroradiology, Montreal, Quebec (Canada)

2011-10-15

Calvarial lesions often present themselves as clinically silent findings on skull radiographs or as palpable masses that may cause localized pain or soreness. This review aims to explore the radiographic, computed tomography (CT), and magnetic resonance imaging (MRI) characteristics of calvarial neoplastic, inflammatory, and congenital lesions that are common in adults in order to facilitate a structured approach to their diagnosis and limit the differential diagnosis. In addition to reviewing the literature, we reviewed the records of 141 patients of the Montreal Neurological Institute and Hospital with radiologically documented calvarial lesions between 2001 and June 2009. CT is ideal for detecting bony lesions and is helpful in precisely localizing a lesion pre-surgically. MRI is best at identifying intradiploic lesions before they affect the cortical tables and is able to establish extraosseous involvement, especially when paramagnetic contrast is employed. (orig.)

Enhanced Healing of Rat Calvarial Defects with MSCs Loaded on BMP-2 Releasing Chitosan/Alginate/Hydroxyapatite Scaffolds

Science.gov (United States)

He, Xiaoning; Liu, Yang; Yuan, Xue; Lu, Li

2014-01-01

In this study, we designed a chitosan/alginate/hydroxyapatite scaffold as a carrier for recombinant BMP-2 (CAH/B2), and evaluated the release kinetics of BMP-2. We evaluated the effect of the CAH/B2 scaffold on the viability and differentiation of bone marrow mesenchymal stem cells (MSCs) by scanning electron microscopy, MTS, ALP assay, alizarin-red staining and qRT-PCR. Moreover, MSCs were seeded on scaffolds and used in a 8 mm rat calvarial defect model. New bone formation was assessed by radiology, hematoxylin and eosin staining 12 weeks postoperatively. We found the release kinetics of BMP-2 from the CAH/B2 scaffold were delayed compared with those from collagen gel, which is widely used for BMP-2 delivery. The BMP-2 released from the scaffold increased MSC differentiation and did not show any cytotoxicity. MSCs exhibited greater ALP activity as well as stronger calcium mineral deposition, and the bone-related markers Col1α, osteopontin, and osteocalcin were upregulated. Analysis of in vivo bone formation showed that the CAH/B2 scaffold induced more bone formation than other groups. This study demonstrates that CAH/B2 scaffolds might be useful for delivering osteogenic BMP-2 protein and present a promising bone regeneration strategy. PMID:25084008

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

Directory of Open Access Journals (Sweden)

Jiyeon Roh

2016-02-01

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

Upper gastrointestinal bleeding, aneurismatic dilatation of the thoracic aorta and filling defect on the esophagogram

Energy Technology Data Exchange (ETDEWEB)

Naschitz, J.E.; Bassan, H.; Lazarov, N.; Grishkan, A.

1982-06-01

A patient is described with an aneurysm of the thoracic aorta, which has ruptured into the esophagus. An esophageal X-ray contrast study has revealed a filling defect at the contact site of the esophagus and the aortic aneurysm. The filling defect was due to a clot protruding from the aorta into the esophagus. This unique case calls attention to a diagnostic triad: upper gastrointestinal bleeding, aneurysm of the thoracic aorta, and filling defect in the esophagus at its site of contact with the enlarged aorta. This triad suggested aortoesophageal fistula (AEF) in the patient and could help in the diagnosis of atypical cases of AEF, where thoracic aortography has not been performed initially.

Upper gastrointestinal bleeding, aneurismatic dilatation of the thoracic aorta and filling defect on the esophagogram

International Nuclear Information System (INIS)

Naschitz, J.E.; Bassan, H.; Lazarov, N.; Grishkan, A.; Haifa Univ.; Haifa Univ.

1982-01-01

A patient is described with an aneurysm of the thoracic aorta, which has ruptured into the esophagus. An esophageal X-ray contrast study has revealed a filling defect at the contact site of the esophagus and the aortic aneurysm. The filling defect was due to a clot protruding from the aorta into the esophagus. This unique case calls attention to a diagnostic triad: upper gastrointestinal bleeding, aneurysm of the thoracic aorta, and filling defect in the esophagus at its site of contact with the enlarged aorta. This triad suggested aortoesophageal fistula (AEF) in the patient and could help in the diagnosis of atypical cases of AEF, where thoracic aortography has not been performed initially. (orig.) [de

Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model

Science.gov (United States)

Zhang, Haifeng; Mao, Xiyuan; Du, Zijing; Jiang, Wenbo; Han, Xiuguo; Zhao, Danyang; Han, Dong; Li, Qingfeng

2016-01-01

We have explored the applicability of printed scaffold by comparing osteogenic ability and biodegradation property of three resorbable biomaterials. A polylactic acid/hydroxyapatite (PLA/HA) composite with a pore size of 500 μm and 60% porosity was fabricated by three-dimensional printing. Three-dimensional printed PLA/HA, β-tricalcium phosphate (β-TCP) and partially demineralized bone matrix (DBM) seeded with bone marrow stromal cells (BMSCs) were evaluated by cell adhesion, proliferation, alkaline phosphatase activity and osteogenic gene expression of osteopontin (OPN) and collagen type I (COL-1). Moreover, the biocompatibility, bone repairing capacity and degradation in three different bone substitute materials were estimated using a critical-size rat calvarial defect model in vivo. The defects were evaluated by micro-computed tomography and histological analysis at four and eight weeks after surgery, respectively. The results showed that each of the studied scaffolds had its own specific merits and drawbacks. Three-dimensional printed PLA/HA scaffolds possessed good biocompatibility and stimulated BMSC cell proliferation and differentiation to osteogenic cells. The outcomes in vivo revealed that 3D printed PLA/HA scaffolds had good osteogenic capability and biodegradation activity with no difference in inflammation reaction. Therefore, 3D printed PLA/HA scaffolds have potential applications in bone tissue engineering and may be used as graft substitutes in reconstructive surgery.

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

Science.gov (United States)

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

2013-01-01

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

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

Science.gov (United States)

Kochetova, Lyudmila A.; Prosvirnin, Sergey L.

2018-04-01

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

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

Directory of Open Access Journals (Sweden)

Georgios Sioutas

2017-06-01

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

Incomplete bone regeneration of rabbit calvarial defects using different membranes

DEFF Research Database (Denmark)

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

1998-01-01

The present study describes the use of a degradable and a non-degradable material for guided bone regeneration. Forty rabbits were divided into 5 groups. Bicortical defects 15 mm in diameter were prepared in rabbit calvaria. A titanium microplate was placed over the defect to prevent collapse...

Multiple calvarial haemangiomas

International Nuclear Information System (INIS)

Corr, P.

2000-01-01

Calvarial haemangiomas are rare benign tumours that may be suspected by their characteristic expansile 'sunburst' appearance. It is important to recognise them as such and to make the surgeon aware of haemorrhage after biopsy or resection. Computed tomography examination confirmed expansile spiculated osteolytic lesions originating from the right occipital calvarium and a smaller lesion from the right frontal bone. The larger lesion had a 'sunburst' appearance. On MR, the morphology of the lesion was more apparent. The tumour had a heterogenous hypointense structure with spiculated bony septa on T1-weighted images and a markedly hyperintense appearance on T2-weighted images. Copyright (1999) Blackwell Science Pty Ltd

Religious Landscape and Ecological Ethics: Pilgrimage to the Lithuanian Calvaries

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Darius Liutikas

2015-07-01

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

Thermoluminescent and dosimetric properties of anion-defective a-Al2O3 single crystals with filled deep traps

International Nuclear Information System (INIS)

Kortov, V.S.; Milman, I.I.; Nikiforov, S.V.

2002-01-01

Some new experimental results illustrating the effect of deep traps on luminescent and dosimetric properties of anion-defective single crystals of a-Al 2 O 3 have been described. It was found that deep traps had an electronic origin. They were filled thanks to the photoionisation of F-centres and their filling was accompanied by the conversion of FF+ centres. The experiments revealed an interactive interaction of deep trapping centres. A model taking into account the thermal ionisation of excited states of F-centres was proposed. This model describes the trap filling process and mechanisms of the radio-, photo- and thermoluminescence, TSC and TSEE of the crystals under study. The sensitivity of TLD-500 detectors based on anion-defective a-Al 2 O 3 equalised when deep trapping centres were filled. (author)

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

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

2014-07-01

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

The utility of computer-aided-detection for the assessment of pulmonary arterial filling defects at CT angiography

International Nuclear Information System (INIS)

Roberts, H.C.; Walsham, A.; Colak, E.; Kashani, H.; Mongiardi, C.; Patsios, D.

2007-01-01

The purpose of this study is to validate a computer assisted detection (CAD) system for the detection of pulmonary intra-arterial filling defects and assess its utility for radiology readers of different levels of experience. Methods: 100 contrast-enhanced computed tomography pulmonary angiograms (CTPAs) performed to rule out pulmonary embolism (PE) were retrospectively analyzed; all were previously read by the chest radiologist on service and were re-assessed by a chest radiologist for the presence and location of PE. CTPAs were analyzed using the second generation CAD software pulmonary artery Patency Exam (PE trademark) tool, used with the ImageChecker registered CT (version 2.1 R2 Technology Inc., Santa Clara, CA). Each CAD mark was assigned one of the following interpretations: true positive, TP: intra-arterial filling defect found by CAD and the radiologist; false positive, FP: CAD mark that was not a filling defect; false negative, FN: filling defect found by the radiologist, but not by CAD. CAD performance was quantified on a per case basis; if CAD did not mark a study negative for PE, this was defined as true negative (TN). If CAD yielded FP marks only in a study positive for PE, this was counted as a FN case. All CTPAs were interpreted by four readers of different levels of experience, both without and with CAD. They recorded the reading time, the presence and location of PE, and the confidence in their diagnosis (1 = least, 2 moderately, 3 = very confident). Results: 21 cases were positive for PE. CAD showed marks in all 21 cases, but in three cases, all were FP marks (3 FN cases, 18 TP cases). Of the 79 exams negative for PE, 16 had no CAD marks (16 TN cases), 63 had at least one CAD mark (63 FP cases). On a case-basis, CAD sensitivity was 86%, negative predictive value was 84%, specificity 20%, positive predictive value (PPV) 22%. In the 21 positive cases, 93 filling defects were identified, of which 64 were correctly marked by CAD (sensitivity 69

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

Science.gov (United States)

Al-Amer, Osama

2017-12-01

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

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

Science.gov (United States)

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

2017-06-01

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

MR findings of calvarial eosinophilic granuloma

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Choi, Gi Bok; Son, Seok Hyun; Eun, Choong Ki; Park, Sung Kun; Han, Sang Suk [Pusan Paik Hospital, Inje Univ., Pusan (Korea, Republic of); Choi, Sun Seob [Donga Univ. College of Medicine, Pusan (Korea, Republic of); Kim, Seong Min [Kosin Univ. College of Medicine, Pusan (Korea, Republic of); Kim, Chang Soo [Maryknoll Hospital, Pusan (Korea, Republic of)

2001-03-01

The purpose of this study was to evaluate the MR findings of calvarial eosinophilic granuloma. We reviewed the MR imaging studies of nine patients [M:F=3:6, aged 6-35 (mean, 20.5) years] with pathologically proven eosinophilic granuloma in the calvaria. The findings were evaluated for involvement of the diploic space, changes in adjacent bone marrow, distinction of the transitional zone, pattern of bone destruction, signal intensity and contrast enhancement of the tumor, and contrast enhancement of the adjacent dura. All lesions involved the diploic space, showed no change in adjacent bone marrow, and had a distinct transitional zone. In most (8/9) cases there was asymmetric bony destruction. On T1-weighted images, signal intensities of the tumors varied, while on T2-weighted images, hyperintensity was observed in seven cases, isointensity in one, and hypointensity in one. After the administration of contrast material, enhancement was homogeneous in four cases and inhomogeneous in five. Enhancement of the adjacent dura was demonstrated in all nine cases. The characteristic MR findings of calvarial eosinophilic granuloma are variable signal intensity on T1WI, high signal intensity on T2WI, and marked contrast enhancement; in addition, there is a distinct transitional zone, asymmetrical bony destruction, and associated dural enhancement.

Ellipsoid analysis of calvarial shape.

Science.gov (United States)

Jacobsen, Petra A; Becker, Devra; Govier, Daniel P; Krantz, Steven G; Kane, Alex

2009-09-01

The purpose of this research was to develop a novel quantitative method of describing calvarial shape by using ellipsoid geometry. The pilot application of Ellipsoid Analysis was to compare calvarial form among individuals with untreated unilateral coronal synostosis, metopic synostosis, and sagittal synostosis and normal subjects. The frontal, parietal, and occipital bones of 10 preoperative patients for each of the four study groups were bilaterally segmented into six regions using three-dimensional skull reconstructions generated by ANALYZE imaging software from high-resolution computed tomography scans. Points along each segment were extracted and manipulated using a MATLAB-based program. The points were fit to the least-squares nearest ellipsoid. Relationships between the six resultant right and left frontal, parietal, and occipital ellipsoidal centroids (FR, FL, PR, PL, OR, and OL, respectively) were tested for association with a synostotic group. Results from the pilot study showed meaningful differences between length ratio, angular, and centroid distance relationships among synostotic groups. The most substantial difference was exhibited in the centroid distance PL-PR between patients with sagittal synostosis and metopic synostosis. The measures most commonly significant were centroid distances FL-PR and FL-PL and the angle OR-FR-PR. Derived centroid relationships were reproducible. Ellipsoid Analysis may offer a more refined approach to quantitative analysis of cranial shape. Symmetric and asymmetric forms can be compared directly. Relevant shape information between traditional landmarks is characterized. These techniques may have wider applicability in quantifying craniofacial morphology with increase in both specificity and general applicability over current methods.

Experiences in Performing Posterior Calvarial Distraction.

Science.gov (United States)

McMillan, Kevin; Lloyd, Mark; Evans, Martin; White, Nicholas; Nishikawa, Hiroshi; Rodrigues, Desiderio; Sharp, Melanie; Noons, Pete; Solanki, Guirish; Dover, Stephen

2017-05-01

The use of posterior calvarial distraction (PCD) for the management of craniosynostosis is well recognized. The advantages of using this technique include increased cranial volume, decreased intracranial pressure, relief of posterior fossa crowding, improved cerebrospinal fluid (CSF) circulation at the cranio-cervical junction with cessation, and possible resolution of syrinx.The authors retrospectively review their first 50 patients who have undergone PCD under the senior author's care in our unit.The demographics, diagnoses, intraoperative approach with techniques in distractor placement and outcomes of each patient were obtained through an electronic craniofacial database and written patient records. Analysis of complication rates (bleeding, distraction problems, CSF leaks, and infection) was included.A total of 31 boys and 19 girls underwent the procedure between October 2006 and September 2015 with a median age was 17.7 months (range 4 months to 19 years). Of those 50 children, 34 of the cohort were proven to be syndromic by genetic testing.The median length of inpatient stay was 9.4 days (range 3-43 days). Average distraction distance was 24 mm.Complications including CSF leaks, bleeding, distractor problems, and severe complications (recorded in 3 patients) are discussed. Our overall complication rate was 50%.Favorable outcomes included resolution of Chiari, syrinx, and raised intracranial pressure in the majority of patients where distraction was successful.The authors recommend that PCD should be considered the primary treatment for increasing calvarial volume. The authors discuss our experiences and technical innovations over the past decade.

Influence of filling fraction on the defect mode and gap closing of a one-dimensional photonic crystal: An analytical approach

International Nuclear Information System (INIS)

Ansari, N.; Tehranchi, M.M.

2010-01-01

Study of the optical properties of the one-dimensional defective photonic crystals using the gap map is improving through the emergence of new analytical methods, which are easy and without any physical restrictions. Gap map is able to monitor the changes in the defect mode frequencies and photonic band gap regions as a function of filling fractions, and all visible spectra in a single graphic presentation. In this paper, by utilizing a novel technique based on Green's function method for analyzing the defect modes, the gap map and gap closing point of a one-dimensional defective photonic crystal have been demonstrated. This method enables study of the defect modes inside the omnidirectional band gap, which is an important object in the designing of the optical filters. Moreover, as a designing criterion, obtaining the gap closing points inside the gap map enables finding of some filling fraction intervals that each one contains several distinct omnidirectional band gaps simultaneously, using a single photonic crystal. This method has been employed for the design of an optical filter at 1.3 and 1.55 μm, which is applicable for telecommunication.

Effects of electron-beam irradiation to the hydroxyapatite and tricalcium phosphate mixtures for the development of new synthetic bone substitutes

Energy Technology Data Exchange (ETDEWEB)

Kim, Soung Min; Eo, Mi Young; Kang, Ji Young; Park, Jung Min; Seo, Mi Hyun; Myoung, Hoon; Lee, Jong Ho [Seoul National Univ., Seoul (Korea, Republic of); Han, Young Hwan; Lee, Byung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-07-01

The aim of this study is to evaluate the effect and potential of electron beam irradiation treatment to new bone formation and healing in rat calvarial bone defects using hydroxyapatite and tricalcium phosphate mixtures. We used 1.0-2.0 MeV linear accelerator and 2.0 MeV superconductive linear accelerator with different irradiation dose such as 1, 30, 60 kGy. Structural changes in this synthetic bone material were analyzed in vitro, such as SEM, elementary and FE-SEM, ATR-IR, and CSR. And after sterilization with ethylene oxide, we use it as a bone graft material, in vivo. Bilateral, standardized truenesses circular calvarial defects, 7.0 mm in diameter, were created in male Sprague-Dawley rats. In each experimental group, the defect was filled with electron beam irradiated synthetic bony mixtures. Rate were sacrificed 2, 4 and 8 weeks post-op. for radiographic, histomorphologic, immunohistochemical staining, TEM, and elementary analysis.

{sup 18}F-FDG-Avid Adenocarcinoma of the Rectum Presenting as a Subtle Filling Defect on Maximum Intensity Projection Image: Report of a Case

Energy Technology Data Exchange (ETDEWEB)

Bahk, Yong Whee; Lee, Kwang Chan [SungAe General Hospital, Seoul (Korea, Republic of)

2009-04-15

{sup 18}F-FDG avid polypoid or tumefacient carcinomas of the gastrointestinal (GI) tract including the rectum are characteristically featured on PET-CT as an intraluminal tumor surrounded by completely or partially cleared background. However, the carcinomas of intramural or sessile variant may not so easily be detected especially when tumors are obliterated by feces or mucus retained in the host bowel loop. Recently, we observed a case of cauliflower-like adenocarcinoma of the rectum that was diagnosed by noting a subtle, flat filling defect created against the background of 'black' feces-mucus filled rectum. To our knowledge such a 'filling defect' produced by sessile tumor has not previously been reported as a useful diagnostic sign of GI tract carcinoma on PET-CT.

Ceramic-polylactide composite material used in a model of healing of osseous defects in rabbits.

Science.gov (United States)

Myciński, Paweł; Zarzecka, Joanna; Skórska-Stania, Agnieszka; Jelonek, Agnieszka; Okoń, Krzysztof; Wróbel, Maria

The growing demand for various kinds of bone regeneration material has in turn increased the desire to find materials with optimal physical, chemical, and biological properties. The objective of the present study was to identify the proportions of ceramic and polylactide components in a bone substitute material prepared in collaboration with the Crystal Chemistry of Drugs Team of the Faculty of Chemistry at the Jagiellonian University, which would be optimal for bone regeneration processes. Another goal was to provide a histological analysis of the influence of a ceramic-polylactide composite on the healing of osseous defects in rabbits. The study was performed on laboratory animals (18 New Zealand White rabbits). The following study groups were formed: - group A (study group, 9 animals) - in this group we performed a histological analysis of healing with a ceramic-polylactide composite based on an 80/20 mix of hydroxyapatite and polylactide; - group B (study group, 9 animals) - in this group we performed a histological analysis of healing with a ceramic-polylactide composite with a reduced amount of hydroxyapatite compared to the previous group, i.e. in a ratio of 61/39; - group K (control, 18 animals) - the control group comprised self-healing, standardised osseous defects prepared in the calvarial bone of the rabbits on the contralateral side. In the assessment of histological samples, we were also able to eliminate individual influences that might have led to differentiation in wound healing. The material used in the histological analysis took the form of rabbit bone tissue samples, containing both defects, with margins of around 0.5 cm, taken 1, 3, and 6 months after the experiment. The osseous defects from groups A and B filled with ceramic-polylactide material healed with less inflammatory infiltration than was the case with control group K. They were also characterised by faster regression, and no resorption or osteonecrosis, which allowed for better

Cell-printing and transfer technology applications for bone defects in mice.

Science.gov (United States)

Tsugawa, Junichi; Komaki, Motohiro; Yoshida, Tomoko; Nakahama, Ken-ichi; Amagasa, Teruo; Morita, Ikuo

2011-10-01

Bone regeneration therapy based on the delivery of osteogenic factors and/or cells has received a lot of attention in recent years since the discovery of pluripotent stem cells. We reported previously that the implantation of capillary networks engineered ex vivo by the use of cell-printing technology could improve blood perfusion. Here, we developed a new substrate prepared by coating glass with polyethylene glycol (PEG) to create a non-adhesive surface and subsequent photo-lithography to finely tune the adhesive property for efficient cell transfer. We examined the cell-transfer efficiency onto amniotic membrane and bone regenerative efficiency in murine calvarial bone defect. Cell transfer of KUSA-A1 cells (murine osteoblasts) to amniotic membrane was performed for 1 h using the substrates. Cell transfer using the substrate facilitated cell engraftment onto the amniotic membrane compared to that by direct cell inoculation. KUSA-A1 cells transferred onto the amniotic membrane were applied to critical-sized calvarial bone defects in mice. Micro-computed tomography (micro-CT) analysis showed rapid and effective bone formation by the cell-equipped amniotic membrane. These results indicate that the cell-printing and transfer technology used to create the cell-equipped amniotic membrane was beneficial for the cell delivery system. Our findings support the development of a biologically stable and effective bone regeneration therapy. Copyright © 2011 John Wiley & Sons, Ltd.

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

Directory of Open Access Journals (Sweden)

Betânia Souza Monteiro

2012-03-01

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

Fronto-Orbital Advancement and Total Calvarial Remodelling for Craniosynostosis

International Nuclear Information System (INIS)

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

2014-01-01

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

* Calvarial Bone Regeneration Is Enhanced by Sequential Delivery of FGF-2 and BMP-2 from Layer-by-Layer Coatings with a Biomimetic Calcium Phosphate Barrier Layer.

Science.gov (United States)

Gronowicz, Gloria; Jacobs, Emily; Peng, Tao; Zhu, Li; Hurley, Marja; Kuhn, Liisa T

2017-12-01

A drug delivery coating for synthetic bone grafts has been developed to provide sequential delivery of multiple osteoinductive factors to better mimic aspects of the natural regenerative process. The coating is composed of a biomimetic calcium phosphate (bCaP) layer that is applied to a synthetic bone graft and then covered with a poly-l-Lysine/poly-l-Glutamic acid polyelectrolyte multilayer (PEM) film. Bone morphogenetic protein-2 (BMP-2) was applied before the coating process directly on the synthetic bone graft and then, bCaP-PEM was deposited followed by adsorption of fibroblast growth factor-2 (FGF-2) into the PEM layer. Cells access the FGF-2 immediately, while the bCaP-PEM temporally delays the cell access to BMP-2. In vitro studies with cells derived from mouse calvarial bones demonstrated that Sca-1 and CD-166 positive osteoblast progenitor cells proliferated in response to media dosing with FGF-2. Coated scaffolds with BMP-2 and FGF-2 were implanted in mouse calvarial bone defects and harvested at 1 and 3 weeks. After 1 week in vivo, proliferation of cells, including Sca-1+ progenitors, was observed with low dose FGF-2 and BMP-2 compared to BMP-2 alone, indicating that in vivo delivery of FGF-2 activated a similar population of cells as shown by in vitro testing. At 3 weeks, FGF-2 and BMP-2 delivery increased bone formation more than BMP-2 alone, particularly in the center of the defect, confirming that the proliferation of the Sca-1 positive osteoprogenitors by FGF-2 was associated with increased bone healing. Areas of bone mineralization were positive for double fluorochrome labeling of calcium and alkaline phosphatase staining of osteoblasts, along with increased TRAP+ osteoclasts, demonstrating active bone formation distinct from the bone-like collagen/hydroxyapatite scaffold. In conclusion, the addition of a bCaP layer to PEM delayed access to BMP-2 and allowed the FGF-2 stimulated progenitors to populate the scaffold before differentiating in

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

Science.gov (United States)

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

2018-09-01

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

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

Science.gov (United States)

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

2015-08-05

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

Osterix-Cre transgene causes craniofacial bone development defect

Science.gov (United States)

Wang, Li; Mishina, Yuji; Liu, Fei

2015-01-01

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

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

Science.gov (United States)

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

2012-01-01

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

Genital and Urinary Tract Defects

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... conditions > Genital and urinary tract defects Genital and urinary tract defects E-mail to a friend Please fill ... and extra fluids. What problems can genital and urinary tract defects cause? Genital and urinary tract defects affect ...

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

OpenAIRE

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

2015-01-01

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

Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-18

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

Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells

International Nuclear Information System (INIS)

Yeh, Lee-Chuan C.; Ford, Jeffery J.; Lee, John C.; Adamo, Martin L.

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Markus D Schofer

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-05-15

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

Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect

Energy Technology Data Exchange (ETDEWEB)

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

2011-02-11

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

Piezosurgery for the repair of middle cranial fossa meningoencephaloceles.

Science.gov (United States)

Acharya, Aanand N; Rajan, Gunesh P

2015-03-01

To describe the use of a piezosurgery medical device to perform a craniotomy and produce a split calvarial graft for the repair of middle cranial fossa meningoencephaloceles. Retrospective case review. Tertiary referral hospital. Ten consecutive patients undergoing middle cranial fossa approach for the repair of meningoencephaloceles. Therapeutic. Intraoperative and postoperative complications, success rate as defined by the ability to fashion a split calvarial graft that achieves complete closure of the tegmen defect. As a secondary outcome measure, evidence of integration of the split calvarial bone graft with the adjacent skull base was assessed. There were no intraoperative or postoperative complications. An appropriately sized calvarial bone graft was produced, and complete closure of the tegmen defect was achieved in all 10 cases. Computed tomography demonstrated evidence of integration of the bone graft in eight cases between 4 and 9 months after surgery. The piezosurgery medical device provides a safe and effective means by which the middle fossa craniotomy and split calvarial bone graft can be produced to repair defects of the middle fossa tegmen, with integration of the bone graft in the majority of cases.

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

Directory of Open Access Journals (Sweden)

Lotta K. Veistinen

2017-12-01

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

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

Science.gov (United States)

Veistinen, Lotta K; Mustonen, Tuija; Hasan, Md Rakibul; Takatalo, Maarit; Kobayashi, Yukiho; Kesper, Dörthe A; Vortkamp, Andrea; Rice, David P

2017-01-01

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

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

Science.gov (United States)

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

2012-09-01

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

Synthetic Defects for Vibrothermography

Science.gov (United States)

Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

2010-02-01

Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.

Platelet rich fibrin in jaw defects

Science.gov (United States)

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.

Mechanics of filled carbon nanotubes

KAUST Repository

Monteiro, A.O.; Cachim, P.B.; Da Costa, Pedro M. F. J.

2014-01-01

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

Mechanics of filled carbon nanotubes

KAUST Repository

Monteiro, A.O.

2014-04-01

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

Bioenergetics during calvarial osteoblast differentiation reflect strain differences in bone mass.

Science.gov (United States)

Guntur, Anyonya R; Le, Phuong T; Farber, Charles R; Rosen, Clifford J

2014-05-01

Osteoblastogenesis is the process by which mesenchymal stem cells differentiate into osteoblasts that synthesize collagen and mineralize matrix. The pace and magnitude of this process are determined by multiple genetic and environmental factors. Two inbred strains of mice, C3H/HeJ and C57BL/6J, exhibit differences in peak bone mass and bone formation. Although all the heritable factors that differ between these strains have not been elucidated, a recent F1 hybrid expression panel (C3H × B6) revealed major genotypic differences in osteoblastic genes related to cellular respiration and oxidative phosphorylation. Thus, we hypothesized that the metabolic rate of energy utilization by osteoblasts differed by strain and would ultimately contribute to differences in bone formation. In order to study the bioenergetic profile of osteoblasts, we measured oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) first in a preosteoblastic cell line MC3T3-E1C4 and subsequently in primary calvarial osteoblasts from C3H and B6 mice at days 7, 14, and 21 of differentiation. During osteoblast differentiation in media containing ascorbic acid and β-glycerophosphate, all 3 cell types increased their oxygen consumption and extracellular acidification rates compared with the same cells grown in regular media. These increases are sustained throughout differentiation. Importantly, C3H calvarial osteoblasts had greater oxygen consumption rates than B6 consistent with their in vivo phenotype of higher bone formation. Interestingly, osteoblasts utilized both oxidative phosphorylation and glycolysis during the differentiation process although mature osteoblasts were more dependent on glycolysis at the 21-day time point than oxidative phosphorylation. Thus, determinants of oxygen consumption reflect strain differences in bone mass and provide the first evidence that during collagen synthesis osteoblasts use both glycolysis and oxidative phosphorylation to synthesize and

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

Directory of Open Access Journals (Sweden)

Carlos Antônio Garrido

2010-01-01

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

Computed tomographic analysis of calvarial hyperostosis in captive lions.

Science.gov (United States)

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

2010-01-01

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

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

OpenAIRE

Lotta K. Veistinen; Tuija Mustonen; Tuija Mustonen; Md. Rakibul Hasan; Maarit Takatalo; Yukiho Kobayashi; Yukiho Kobayashi; Dörthe A. Kesper; Andrea Vortkamp; David P. Rice; David P. Rice

2017-01-01

Loss-of-function mutations in GLI3 and IHH cause craniosynostosis and reduced osteogenesis, respectively. In this study, we show that Ihh ligand, the receptor Ptch1 and Gli transcription factors are differentially expressed in embryonic mouse calvaria osteogenic condensations. We show that in both Ihh−/− and Gli3Xt−J/Xt−J embryonic mice, the normal gene expression architecture is lost and this results in disorganized calvarial bone development. RUNX2 is a master regulatory transcription facto...

Birth Defects: Cerebral Palsy

Science.gov (United States)

... Loss > Birth defects & other health conditions > Cerebral palsy Cerebral palsy E-mail to a friend Please fill in ... this page It's been added to your dashboard . Cerebral palsy (also called CP) is a group of conditions ...

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

International Nuclear Information System (INIS)

Pill Hoon Choung; Eun Seok Kim

1999-01-01

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

Revascularization of calvarial, mandibular, tibial, and iliac bone grafts in rats

DEFF Research Database (Denmark)

Pinholt, E M; Solheim, E; Talsnes, O

1994-01-01

Some studies have suggested that membranous bone grafts undergo less resorption than endochondral grafts, and faster revascularization of the former has been proposed as the explanation. We studied fresh syngeneic full-thickness bone grafts from calvaria, mandibula, tibia diaphysis, and iliac bone...... implanted in the back muscles of young Lewis rats. As a measure of the quantity of cancellous bone in grafts before implantation, the ratio of the total area of soft-tissue spaces to the total area of the graft was measured histomorphometrically. Revascularization in grafts 3 weeks postoperatively...... was evaluated by deposit of 141Ce-labeled microspheres. Both the quantity of cancellous bone (before implantation) and the revascularization (3 weeks postoperatively) were greater in the mandibular and iliac bone grafts than in the calvarial and tibia diaphyseal grafts. The results suggest that the anatomical...

Reprogramming of Mouse Calvarial Osteoblasts into Induced Pluripotent Stem Cells

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Yinxiang Wang

2018-01-01

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

Bone tissue engineering with a collagen–hydroxyapatite scaffold and culture expanded bone marrow stromal cells

Science.gov (United States)

Villa, Max M.; Wang, Liping; Huang, Jianping; Rowe, David W.; Wei, Mei

2015-01-01

Osteoprogenitor cells combined with supportive biomaterials represent a promising approach to advance the standard of care for bone grafting procedures. However, this approach faces challenges, including inconsistent bone formation, cell survival in the implant, and appropriate biomaterial degradation. We have developed a collagen–hydroxyapatite (HA) scaffold that supports consistent osteogenesis by donor derived osteoprogenitors, and is more easily degraded than a pure ceramic scaffold. Herein, the material properties are characterized as well as cell attachment, viability, and progenitor distribution in vitro. Furthermore, we examined the biological performance in vivo in a critical-size mouse calvarial defect. To aid in the evaluation of the in-house collagen–HA scaffold, the in vivo performance was compared with a commercial collagen–HA scaffold (Healos®, Depuy). The in-house collagen–HA scaffold supported consistent bone formation by predominantly donor-derived osteoblasts, nearly completely filling a 3.5 mm calvarial defect with bone in all samples (n=5) after 3 weeks of implantation. In terms of bone formation and donor cell retention at 3 weeks postimplantation, no statistical difference was found between the in-house and commercial scaffold following quantitative histomorphometry. The collagen–HA scaffold presented here is an open and well-defined platform that supports robust bone formation and should facilitate the further development of collagen–hydroxyapatite biomaterials for bone tissue engineering. PMID:24909953

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

Science.gov (United States)

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

2016-01-01

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

Raman study of the effect of LED light on grafted bone defects

Science.gov (United States)

Soares, Luiz G. G. P.; Aciole, Jouber M. S.; Aciole, Gilbeth T. S.; Barbosa, Artur F. S.; Silveira-Júnior, Landulfo; Pinheiro, Antônio L. B.

2013-03-01

Benefits of the isolated or combined use light and biomaterials on bone healing have been suggested. Our group has used several models to assess the effects of laser on bone. A Raman spectral analysis on surgical bone defects grafted or not with Hydroxyapatite (HA), treated or not with LED was carried out. 40 rats were divided into 4 groups. On Group I the defect was filled with the clot. On Group II, the defect was filled with the HA. On groups III the defect was filled with Clot and further irradiated with LED and on group IV the defects was filled with the HA and further irradiated with LED. LED (λ850 +/- 10nm, 150mW, A= 0.5cm2, 68s, 20 J/cm2 per session, 140 J/cm2 per treatment) was applied at 48 h intervals during 15 days. Specimens were taken after 15 and 30 days after surgery and kept on liquid nitrogen, and underwent Raman analysis. For this, the peak of hydroxyapatite (~960 cm-1) was used as marker of bone mineralization. Significant difference was observed at both times (p<0.05). When the biomaterial was used higher peaks were observed. Association with LED further improved the intensity. Conclusion: It is concluded that LED light improved the effect of the HA.

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

International Nuclear Information System (INIS)

Xie Lei; Ziegmann, Gerhard

2011-01-01

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

Selective isolation and differentiation of a stromal population of human embryonic stem cells with osteogenic potential

DEFF Research Database (Denmark)

Harkness, Linda M; Mahmood, Amer; Ditzel, Nicholas

2011-01-01

cultured in osteogenic differentiation media, up regulation of osteoblastic lineage markers (DLX5, MSX2, RUNX2, SPARC, ALP, COL1a1, BGLAP, IBSP, DCN, LOX-L4) and production of in vitro mineralized matrix was detected. hESC-stromal cells loaded on a carrier and implanted either subcutaneously...... or in a critical size calvarial defect in immune deficient mice for 10weeks, resulted in new bone formation and partial repair of the calvarial defect. In conclusion, hESC-stromal can be isolated from hESC cultures and represent a good source for obtaining cells with osteogenic differentiation potential suitable...

Possible mechanism for d0 ferromagnetism mediated by intrinsic defects

KAUST Repository

Zhang, Zhenkui

2014-01-01

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

Accounting for cranial vault growth in experimental design.

Science.gov (United States)

Power, Stephanie M; Matic, Damir B; Holdsworth, David W

2014-05-01

Earlier studies have not accounted for continued growth when using the rat calvarial defect model to evaluate bone healing in vivo. The purpose of this study was: 1) to calculate rat cranial vault growth over time; and 2) to determine the effects of accounting for growth on defect healing. Bilateral parietal defects were created in 10 adult Wistar rats. Serial microscopic computerized tomography scans were performed. Bone mineral content (BMC) measured according to standard technique and repeated accounting for cranial growth over time was compared with the use of parametric and nonparametric tests. Cranial vault growth continued through 22 weeks of age, increasing 7.5% in width and 9.1% in length, and calvarial defects expanded proportionately. BMC was greater within defects accounting for growth 2-12 weeks postoperatively (P accounting for cranial growth given advances in serial imaging techniques. Crown Copyright © 2014. Published by Mosby, Inc. All rights reserved.

Three-dimensional poly (ε-caprolactone)/hydroxyapatite/collagen scaffolds incorporating bone marrow mesenchymal stem cells for the repair of bone defects

International Nuclear Information System (INIS)

Qi, Xin; Huang, Yinjun; Zhang, Jieyuan; Cao, Jiaqing; Jin, Xiangyun; Huang, Jinghuan; Li, Xiaolin; Wang, Ting; Han, Dan

2016-01-01

We previously demonstrated that three-dimensional (3D) hydroxyapatite (HAP)-collagen (COL)-coated poly(ε-caprolactone) (PCL) scaffolds (HAP-COL-PCL) possess appropriate nano-structures, surface roughness, and nutrients, providing a favorable environment for osteogenesis. However, the effect of using 3D HAP-COL-PCL scaffolds incorporating BMSCs for the repair of bone defects in rats has been not evaluated. 3D PCL scaffolds coated with HAP, collagen or HAP/COL and incorporating BMSCs were implanted into calvarial defects. At 12 weeks after surgery, the rats were sacrificed and crania were harvested to assess the bone defect repair using microcomputed tomography (micro-CT), histology, immunohistochemistry and sequential fluorescent labeling analysis. 3D micro-CT reconstructed images and quantitative analysis showed that HAP-COL-PCL groups possessed better bone-forming capacity than HAP-PCL groups or COL-PCL groups. Fluorescent labeling analysis revealed the percentage of tetracycline labeling, alizarin red labeling, and calcein labeling in HAP-COL-PCL groups were all greater than in the other two groups (P  <  0.05), and the result was confirmed by immunohistochemical staining and histological analysis of bone regeneration. This study demonstrates that 3D HAP-COL-PCL scaffolds incorporating BMSCs markedly enhance bone regeneration of bone defects in rats. (paper)

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

Directory of Open Access Journals (Sweden)

Sharath K Shetty

2009-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-01

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

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

International Nuclear Information System (INIS)

Lin, Yinan; Xiao, Wei; Bal, B. Sonny; Rahaman, Mohamed N.

2016-01-01

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

[Clinical and ossification outcome of custom-made hydroxyapatite prothese for large skull defect].

Science.gov (United States)

Hardy, H; Tollard, E; Derrey, S; Delcampe, P; Péron, J-M; Fréger, P; Proust, F

2012-02-01

Cranioplasty is an everyday concern in neurosurgery, especially in decompressive craniectomy cases. Our surgical team uses custom-made hydroxyapatite implants for large and/or complex defects. Eight patients had a custom-made prosthesis. Each of them has been reviewed by an independent observer. Each patient described his feeling of satisfaction, using a questionnaire, graduated from "A" (really satisfied) to "D" (unsatisfied). Each of them also underwent a CT-scan (helicoidal acquisition, 0.6mm thick for multiplanar reconstruction) to evaluate qualitatively the ossification graduated from "0" (no ossification) to "5" (continuous ossification). Maximal under-prosthetic bone thickness, intra-prosthetic calcic density were also reported. Supervision delay was 43.7 months [6-99 months], average defect surface was 85.5 cm(2) [27.6-137.6 cm(2)], the craniectomy etiologies were intracranial hypertension (seven patients) and calvarial invasion (one patient). Implant tolerance was reparted in "A" score (50%) and "B" score (50%). Concerning ossification, six patients (75%) had a score of "2" or less and two patients had a score of "3" or "4". Hydroxyapatite custom-made implants for cranioplasty appear to be ideal for good aesthetic and tolerance results, but their ossification is hardly analyzed due to the prosthesis density higher than the bone's density. This is why we recommend them for children and in cases of complex defects such as pterion location. Copyright © 2011. Published by Elsevier Masson SAS.

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

Science.gov (United States)

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

2017-10-01

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

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

Directory of Open Access Journals (Sweden)

O. V. Korenkov

2017-06-01

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

A computational framework for automation of point defect calculations

International Nuclear Information System (INIS)

Goyal, Anuj; Gorai, Prashun; Peng, Haowei

2017-01-01

We have developed a complete and rigorously validated open-source Python framework to automate point defect calculations using density functional theory. Furthermore, the framework provides an effective and efficient method for defect structure generation, and creation of simple yet customizable workflows to analyze defect calculations. This package provides the capability to compute widely-accepted correction schemes to overcome finite-size effects, including (1) potential alignment, (2) image-charge correction, and (3) band filling correction to shallow defects. Using Si, ZnO and In2O3 as test examples, we demonstrate the package capabilities and validate the methodology.

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

Science.gov (United States)

Straub, Jeremy

2017-06-01

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

Chitosan-glycerol phosphate/blood implants improve hyaline cartilage repair in ovine microfracture defects.

Science.gov (United States)

Hoemann, Caroline D; Hurtig, Mark; Rossomacha, Evgeny; Sun, Jun; Chevrier, Anik; Shive, Matthew S; Buschmann, Michael D

2005-12-01

Microfracture is a surgical procedure that is used to treat focal articular cartilage defects. Although joint function improves following microfracture, the procedure elicits incomplete repair. As blood clot formation in the microfracture defect is an essential initiating event in microfracture therapy, we hypothesized that the repair would be improved if the microfracture defect were filled with a blood clot that was stabilized by the incorporation of a thrombogenic and adhesive polymer, specifically, chitosan. The objectives of the present study were to evaluate (1) blood clot adhesion in fresh microfracture defects and (2) the quality of the repair, at six months postoperatively, of microfracture defects that had been treated with or without chitosan-glycerol phosphate/blood clot implants, using a sheep model. In eighteen sheep, two 1-cm2 full-thickness chondral defects were created in the distal part of the femur and treated with microfracture; one defect was made in the medial femoral condyle, and the other defect was made in the trochlea. In four sheep, microfracture defects were created bilaterally; the microfracture defects in one knee received no further treatment, and the microfracture defects in the contralateral knee were filled with chitosan-glycerol phosphate/autologous whole blood and the implants were allowed to solidify. Fresh defects in these four sheep were collected at one hour postoperatively to compare the retention of the chitosan-glycerol phosphate/blood clot with that of the normal clot and to define the histologic characteristics of these fresh defects. In the other fourteen sheep, microfracture defects were made in only one knee and either were left untreated (control group; six sheep) or were treated with chitosan-glycerol phosphate/blood implant (treatment group; eight sheep), and the quality of repair was assessed histologically, histomorphometrically, and biochemically at six months postoperatively. In the defects that were examined

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

NARCIS (Netherlands)

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

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

Interdisciplinary Management of an Isolated Intrabony Defect

Directory of Open Access Journals (Sweden)

Sheetal Ghivari

2014-01-01

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

21 CFR 1305.15 - Unaccepted and defective DEA Forms 222.

Science.gov (United States)

2010-04-01

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

Phononic crystals with one-dimensional defect as sensor materials

Science.gov (United States)

Aly, Arafa H.; Mehaney, Ahmed

2017-09-01

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

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

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Amir Sotoudeh

2013-05-01

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

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

DEFF Research Database (Denmark)

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

1994-01-01

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

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

Science.gov (United States)

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

2018-04-01

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

Magnetoencephalography signals are influenced by skull defects.

Science.gov (United States)

Lau, S; Flemming, L; Haueisen, J

2014-08-01

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

Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

Science.gov (United States)

Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

2016-01-01

Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

Dietary arginine silicate inositol complex increased bone healing: histologic and histomorphometric study

Directory of Open Access Journals (Sweden)

Yaman F

2016-06-01

Full Text Available Ferhan Yaman,1 Izzet Acikan,1 Serkan Dundar,2 Sercan Simsek,3 Mehmet Gul,4 İbrahim Hanifi Ozercan,3 James Komorowski,5 Kazim Sahin6 1Department of Oral-Maxillofacial Surgery, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey; 2Department of Periodontology, Faculty of Dentistry, Firat University, Elazig, Turkey; 3Department of Pathology, Faculty of Medicine, Firat University, Elazig, Turkey; 4Department of Periodontology, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey; 5Nutrition 21, LLC, Purchase, NY, USA; 6Department of Animal Nutrition, Faculty of Veterinary Medicine, Firat University, Elazig, Turkey Background: Arginine silicate inositol complex (ASI; arginine 49.5%, silicon 8.2%, and inositol 25% is a novel material that is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health. Objective: The aim of this study was to evaluate the potential effects of ASI complex on bone healing of critical-sized defects in rats. Methods: The rats were randomly assigned to two groups of 21 rats each. The control group was fed a standard diet for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The ASI group was fed a diet containing 1.81 g/kg of ASI for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The calvarial bones of all the rats were then harvested for evaluation. Results: Osteoblasts and osteoclasts were detected at higher levels in the ASI group compared with the control group at days 7, 14, and 28 of the calvarial defect (P<0.05. New bone formation was detected at higher levels in the ASI group compared with the controls at day 28 (P<0.05. However, new bone formation was not detected at days 7 and 14 in both the groups (P>0.05. Conclusion: ASI supplementation significantly improved bone tissue

Analysis of Filling and Stresses in the Hot Forging Process Depending on Flange Die Shapes

International Nuclear Information System (INIS)

Kim, Jun Hyoung; Kim, Cheol

2010-01-01

Hot closed-forging process and the die used for forming an automotive flange were analyzed from the viewpoints of heat transfer, grain-flow lines, and stresses to obtain a forged product without defects such as surface cracks, laps, cold shots, and partial filling. The forging process including up-set, pre-forging, final forging and pressing forces was investigated using finite element analysis. The influence of the preform die and the ratio of the heights of the upper die to lower die on the forging process and die were investigated and a die shape (10 .deg. for the preform die, and 1.5:1 ratio for the final die) suitable to achieve successful forging was determined on the basis of a parametric study. All parametric design requirements such as strength, full filling, and a load limit of 13,000 KN were satisfied for this newly developed flange die. New dies and flanges were fabricated and investigated. Defects such as partial filling and surface cracks were not observed

Ultrasonography of Midline Scalp Masses : A Preliminary Report

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyo Kyeong; Lee, Ho Kyu; Choi, Choong Gon; Kim, Kyeong Sook; Jung, Seung Mun; Suh, Dae Chul [Asan Medical Center University of Ulsan College of Medicine, Seoul (Korea, Republic of)

1995-06-15

We report our ultrasonographic experiences in the evaluation of small midline scalp masses. Ultrasonography was performed in four patients with midline scalp mass less than 3cm and its connecting tract into the cranialcavity. Ultrasonographic findings were correlated with pathologic results. There were three cephaloceles and one cystic lymph angioma. Two encephalomenin-goceles, located in occipital region, were mixed cystic and solid lesions and one atretic meningocele in parietal region was a solid lesion. Ultrasonogram of all three cases showed calvarial defect and connecting tract into the cranial cavity. On the contrary, a cystic lymph angioma in occipital region was a purely cystic mass without an associated calvarial defect. We suppose that ultrasonography could be a useful screening tool in the evaluation of midline scalp masses

High resolution deep level transient spectroscopy and process-induced defects in silicon

International Nuclear Information System (INIS)

Evans-Freeman, J.H.; Emiroglu, D.; Vernon-Parry, K.D.

2004-01-01

High resolution, or Laplace, deep level transient spectroscopy (LDLTS) enables the identification of very closely spaced energetic levels in a semiconductor bandgap. DLTS may resolve peaks with a separation of tens of electron volts, but LDLTS can resolve defect energy separations as low as a few MeV. In this paper, we present results from LDLTS applied to ion implantation-induced defects in silicon, with particular emphasis on characterisation of end-of-range interstitial type defects. Silicon was implanted with a variety of ions from mass 28 to 166. A combination of LDLTS and direct capture cross-section measurements was employed to show that electrically active small extended defects were present in the as-implanted samples. Larger dislocations were then generated in Si by oxygenation to act as a control sample. These stacking faults had typical lengths of microns, and their electrical activity was subsequently characterised by LDLTS. This was to establish the sensitivity of LDLTS to defects whose carrier capture is characterised by a non-exponential filling process and an evolving band structure as carrier capture proceeds. The LDLTS spectra show several components in capacitance transients originating from both the end-of-range defects, and the stacking faults, and also clearly show that the carrier emission rates reduce as these extended defects fill with carriers. The end-of-range defects and the stacking faults are shown to have the same electrical behaviour

Repair of sheep long bone cortical defects filled with COLLOSS, COLLOSS E, OSSAPLAST, and fresh iliac crest autograft.

Science.gov (United States)

Huffer, William E; Benedict, James J; Turner, A S; Briest, Arne; Rettenmaier, Robert; Springer, Marco; Walboomers, X F

2007-08-01

COLLOSS and COLLOSS E are osteoinductive bone void fillers consisting of bone collagen and noncollagenous proteins from bovine and equine bone, respectively. The aim of this study was to compare COLLOSS, COLLOSS E, iliac bone autograft, sintered beta tricalcium phosphate (beta-TCP; OSSAPLAST), and COLLOSS E plus OSSAPLAST. Materials were placed for 4, 8, or 24 weeks in 5-mm cortical bone defects in sheep long bones. Histological sections in a plane perpendicular to the long axis of the bone were used to measure the total repair area (original defect plus callus) and the area of bone within the total repair area. The incidence of defect union was also evaluated. At 4 and 8 weeks, defects treated with COLLOSS and COLLOSS E with or without OSSAPLAST had total repair and bone areas equivalent to autograft, and larger than OSSAPLAST-treated defects. At 8 weeks, the incidence of defect union was higher in defects treated with autograft or COLLOSS E plus OSSAPLAST than in untreated defects. At 24 weeks, the incidence of union was 100% in all treatment groups and 0% in untreated defects. The incidence of union was related to the degree of remodeling between 8 and 24 weeks. This was greater in all treated than nontreated defects. In conclusion, COLLOSS and COLLOSS E were equivalent to each other and to autograft, and superior to beta-TCP, in this study model.

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

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Tirthankar Debnath

2014-01-01

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

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

LENUS (Irish Health Repository)

O'Duffy, F

2012-02-01

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

[Progress of Masquelet technique to repair bone defect].

Science.gov (United States)

Yin, Qudong; Sun, Zhenzhong; Gu, Sanjun

2013-10-01

To summarize the progress of Masquelet technique to repair bone defect. The recent literature concerning the application of Masquelet technique to repair bone defect was extensively reviewed and summarized. Masquelet technique involves a two-step procedure. First, bone cement is used to fill the bone defect after a thorough debridement, and an induced membrane structure surrounding the spacer formed; then the bone cement is removed after 6-8 weeks, and rich cancellous bone is implanted into the induced membrane. Massive cortical bone defect is repaired by new bone forming and consolidation. Experiments show that the induced membrane has vascular system and is also rich in vascular endothelial growth factor, transforming growth factor beta1, bone morphogenetic protein 2, and bone progenitor cells, so it has osteoinductive property; satisfactory results have been achieved in clinical application of almost all parts of defects, various types of bone defect and massive defect up to 25 cm long. Compared with other repair methods, Masquelet technique has the advantages of reliable effect, easy to operate, few complications, low requirements for recipient site, and wide application. Masquelet technique is an effective method to repair bone defect and is suitable for various types of bone defect, especially for bone defects caused by infection and tumor resection.

Three dimensional printing of calcium sulfate and mesoporous bioactive glass scaffolds for improving bone regeneration in vitro and in vivo

Science.gov (United States)

Qi, Xin; Pei, Peng; Zhu, Min; Du, Xiaoyu; Xin, Chen; Zhao, Shichang; Li, Xiaolin; Zhu, Yufang

2017-02-01

In the clinic, bone defects resulting from infections, trauma, surgical resection and genetic malformations remain a significant challenge. In the field of bone tissue engineering, three-dimensional (3D) scaffolds are promising for the treatment of bone defects. In this study, calcium sulfate hydrate (CSH)/mesoporous bioactive glass (MBG) scaffolds were successfully fabricated using a 3D printing technique, which had a regular and uniform square macroporous structure, high porosity and excellent apatite mineralization ability. Human bone marrow-derived mesenchymal stem cells (hBMSCs) were cultured on scaffolds to evaluate hBMSC attachment, proliferation and osteogenesis-related gene expression. Critical-sized rat calvarial defects were applied to investigate the effect of CSH/MBG scaffolds on bone regeneration in vivo. The in vitro results showed that CSH/MBG scaffolds stimulated the adhesion, proliferation, alkaline phosphatase (ALP) activity and osteogenesis-related gene expression of hBMSCs. In vivo results showed that CSH/MBG scaffolds could significantly enhance new bone formation in calvarial defects compared to CSH scaffolds. Thus 3D printed CSH/MBG scaffolds would be promising candidates for promoting bone regeneration.

Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells.

Science.gov (United States)

Yeh, Lee-Chuan C; Ford, Jeffery J; Lee, John C; Adamo, Martin L

2014-07-18

Aging is associated with the accumulation of ectopic lipid resulting in the inhibition of normal organ function, a phenomenon known as lipotoxicity. Within the bone marrow microenvironment, elevation in fatty acid levels may produce an increase in osteoclast activity and a decrease in osteoblast number and function, thus contributing to age-related osteoporosis. However, little is known about lipotoxic mechanisms in intramembraneous bone. Previously we reported that the long chain saturated fatty acid palmitate inhibited the expression of the osteogenic markers RUNX2 and osteocalcin in fetal rat calvarial cell (FRC) cultures. Moreover, the acetyl CoA carboxylase inhibitor TOFA blocked the inhibitory effect of palmitate on expression of these two markers. In the current study we have extended these observations to show that palmitate inhibits spontaneous mineralized bone formation in FRC cultures in association with reduced mRNA expression of RUNX2, alkaline phosphatase, osteocalcin, and bone sialoprotein and reduced alkaline phosphatase activity. The effects of palmitate on osteogenic marker expression were inhibited by TOFA. Palmitate also inhibited the mRNA expression of fatty acid synthase and PPARγ in FRC cultures, and as with osteogenic markers, this effect was inhibited by TOFA. Palmitate had no effect on FRC cell proliferation or apoptosis, but inhibited BMP-7-induced alkaline phosphatase activity. We conclude that palmitate accumulation may lead to lipotoxic effects on osteoblast differentiation and mineralization and that increases in fatty acid oxidation may help to prevent these lipotoxic effects. Copyright © 2014 Elsevier Inc. All rights reserved.

Reconstruction for Skull Base Defect Using Fat-Containing Perifascial Areolar Tissue.

Science.gov (United States)

Choi, Woo Young; Sung, Ki Wook; Kim, Young Seok; Hong, Jong Won; Roh, Tai Suk; Lew, Dae Hyun; Chang, Jong Hee; Lee, Kyu Sung

2017-06-01

Skull base reconstruction is a challenging task. The method depends on the anatomical complexity and size of the defect. We obtained tissue by harvesting fat-containing perifascial areolar tissue (PAT) for reconstruction of limited skull base defects and volume augmentation. We demonstrated the effective option for reconstruction of limited skull base defects and volume augmentation. From October 2013 to November 2015, 5 patients underwent operations using fat-containing PAT to fill the defect in skull base and/or perform volume replacement in the forehead. Perifascial areolar tissue with 5- to 10-mm fat thickness was harvested from the inguinal region. The fat-containing PAT was grafted to the defect contacting the vascularized wound bed. Patients were followed up in terms of their clinical symptoms and postoperative magnetic resonance imaging findings. Four patients were treated using fat-containing PAT after tumor resection. One patient was treated for a posttraumatic forehead depression deformity. The fat-containing PAT included 5- to 9-mm fat thickness in all cases. The mean size of grafted PAT was 65.6 cm (28-140 cm). The mean follow-up period was 18.6 months (12-31 months). There was no notable complication. There was no donor site morbidity. We can harvest PAT with fat easily and obtain the sufficient volume to treat the defect. It also could be used with other reconstructive method, such as a free flap or a regional flap to fill the left dead space. Therefore, fat-containing PAT could be additional options to reconstruction of skull base defect.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Synergistic effects of dimethyloxallyl glycine and recombinant human bone morphogenetic protein-2 on repair of critical-sized bone defects in rats

Science.gov (United States)

Qi, Xin; Liu, Yang; Ding, Zhen-Yu; Cao, Jia-Qing; Huang, Jing-Huan; Zhang, Jie-Yuan; Jia, Wei-Tao; Wang, Jing; Liu, Chang-Sheng; Li, Xiao-Lin

2017-02-01

In bone remodeling, osteogenesis is closely coupled to angiogenesis. Bone tissue engineering using multifunctional bioactive materials is a promising technique which has the ability to simultaneously stimulate osteogenesis and angiogenesis for repair of bone defects. We developed mesoporous bioactive glass (MBG)-doped poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) composite scaffolds as delivery vehicle. Two bioactive molecules, dimethyloxalylglycine (DMOG), a small-molecule angiogenic drug, and recombinant human bone morphogenetic protein-2 (rhBMP-2), an osteoinductive growth factor, were co-incorporated into the scaffold. The synergistic effects of DMOG and rhBMP-2 released in the composite scaffolds on osteogenic and angiogenic differentiation of hBMSCs were investigated using real-time quantitative polymerase chain reaction and western blotting. Moreover, in vivo studies were conducted to observe bone regeneration and vascular formation of critical-sized bone defects in rats using micro-computed tomography, histological analyses, Microfil® perfusion, fluorescence labeling, and immunohistochemical analysis. The results showed that DMOG and rhBMP-2 released in the MBG-PHBHHx scaffolds did exert synergistic effects on the osteogenic and angiogenic differentiation of hBMSCs. Moreover, DMOG and rhBMP-2 produced significant increases in newly-formed bone and neovascularization of calvarial bone defects in rats. It is concluded that the co-delivery strategy of both rhBMP-2 and DMOG can significantly improve the critical-sized bone regeneration.

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

Science.gov (United States)

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

2007-12-01

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

Bone regeneration of critical calvarial defect in goat model by PLGA/TCP/rhBMP-2 scaffolds prepared by low-temperature rapid-prototyping technology.

Science.gov (United States)

Yu, D; Li, Q; Mu, X; Chang, T; Xiong, Z

2008-10-01

Active artificial bone composed of poly lactide-co-glycolide (PLGA)/ tricalcium phosphate (TCP) was prefabricated using low-temperature rapid-prototyping technology so that the process of osteogenesis could be observed in it. PLGA and TCP were the primary materials, they were molded at low temperature, then recombinant human bone morphogenetic protein-2 (rhBMP-2) was added to form an active artificial bone. Goats with standard cranial defects were randomly divided into experimental (implants with rhBMP-2 added) and control (implants without rhBMP-2) groups, and osteogenesis was observed and evaluated by imaging and biomechanical and histological examinations. The PLGA-TCP artificial bone scaffold (90% porosity) had large and small pores of approximately 360microm and 3-5microm diameter. Preliminary and complete repair of the cranial defect in the goats occurred 12 and 24 weeks after surgery, respectively. The three-point bending strength of the repaired defects attained that of the normal cranium. In conclusion, low-temperature rapid-prototyping technology can preserve the biological activity of this scaffold material. The scaffold has a good three-dimensional structure and it becomes an active artificial bone after loading with rhBMP-2 with a modest degradation rate and excellent osteogenesis in the goat.

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

Science.gov (United States)

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

2018-06-01

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

Defect-induced mix experiment for NIF

Directory of Open Access Journals (Sweden)

Schmitt M.J.

2013-11-01

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

Method for the detection of defective nuclear fuel assemblies

International Nuclear Information System (INIS)

Lawrie, W.E.; Womack, R.E.; White, N.W. Jr.

1978-01-01

There is applied an ultrasonic transmitter on a tape carrier by means of which the ultrasonic transmitter can be guided underwater between the fuel assemblies. If a fuel assembly is defective, i.e. filled with water, the reflection coefficient at the front interface between cladding and inner space of the fuel assembly will decrease. Essential parts of the ultrasonic signal will move through the liquid and will not be reflected until the backward liquid/metal interface of the fuel assembly. This impulse echo is different from that of the gas-filled fuel assembly. (DG) [de

Platelet rich fibrin and xenograft in treatment of intrabony defect

Directory of Open Access Journals (Sweden)

Saurav Panda

2014-01-01

Full Text Available For complete periodontal regeneration, delivery of growth factors in the local environment holds a great deal in adjunct to bone grafts. Platelet rich fibrin (PRF is considered as second generation platelet concentrate, consisting of viable platelets, releasing various growth factors such as platelet-derived growth factor, vascular endothelial growth factor, transforming growth factor, insulin-like growth factor, epidermal growth factor and basic fibroblast growth factor. Hence, this case report aims to investigate the clinical and radiological (bone fill effectiveness of autologous PRF along with the use of xenogenic bone mineral in the treatment of intra bony defects. Intrabony defect was treated with autologous PRF along with the use of xenogenic bone mineral. A decrease in probing pocket depth, gain in clinical attachment level and significant bone fill was observed at end of 6 months. The result obtained with the use of PRF may be attributed to the sustained and simultaneous release of various growth factors over a period of 7 days. In this case report, the positive clinical impact of additional application of PRF with xenogenic graft material in the treatment of periodontal intrabony defect was seen.

Do laser/LED phototherapies influence the outcome of the repair of surgical bone defects grafted with biphasic synthetic microgranular HA + β-tricalcium phosphate? A Raman spectroscopy study.

Science.gov (United States)

Soares, Luiz Guilherme Pinheiro; Marques, Aparecida Maria Cordeiro; Aciole, Jouber Mateus Santos; da Guarda, Milena Góes; Cangussú, Maria Cristina Teixeira; Silveira, Landulfo; Pinheiro, Antonio Luiz Barbosa

2014-09-01

The treatment of bone loss is difficult. Many techniques are proposed to improve repair, including biomaterials and, recently, phototherapies. This work studied bone mineralization by Raman spectroscopy assessing intensities of Raman peaks of both inorganic (∼ 960, ∼ 1,070 cm(-1)) and organic (∼ 1,454 cm(-1)) contents in animal model. Six groups were studied: clot, laser, light-emitting diode (LED), biomaterial (HA + β-tricalcium phosphate), laser + biomaterial, and LED + biomaterial. Defects at right tibia were performed with a drill. When indicated, defects were further irradiated at a 48-h interval during 2 weeks. At the 15th and 30th days, the tibias were withdrawn and analyzed. The ∼ 960-cm(-1) peak was significantly affected by phototherapy on both clot- and biomaterial-filled defects. The ∼ 1,070-cm(-1) peak was affected by both time and the use of the LED light on clot-filled defects. On biomaterial-filled defects, only the use of the laser light significantly influenced the outcome. No significant influence of either the time or the use of the light was detected on clot-filled defects as regards the ∼ 1,454-cm(-1) peak. Raman intensities of both mineral and matrix components indicated that the use of laser and LED phototherapies improved the repair of bone defects grafted or not with biphasic synthetic microgranular HA + β-tricalcium phosphate.

Hydroxyapatite clay for gap filling and adequate bone ingrowth.

Science.gov (United States)

Maruyama, M; Terayama, K; Ito, M; Takei, T; Kitagawa, E

1995-03-01

In uncemented total hip arthroplasty, a complete filling of the gap between femoral prosthesis and the host bone is difficult and defects would remain, because the anatomy of the reamed intramedullary canal cannot fit the prosthesis. Therefore, it seems practical to fill the gap with a clay containing hydroxyapatite (HA), which has an osteoconductive character. The clay (HA clay) is made by mixing HA granules (size 0.1 mm or more) having a homogeneous pore distribution and a porosity of 35-48 vol%, and a viscous substance such as a saline solution of sodium alginate (SSSA). In the first experiment, the ratio of HA granules and sodium alginate in SSSA is set for the same handling properties of HA clay and polymethylmethacrylate bone cement (standard viscosity) before hardening. As a result, the ratio is set for 55 wt% of HA in the clay and 12.5 wt% of sodium alginate in SSSA (i.e., HA:sodium alginate:saline solution = 9.8:1:7). In the second study, the gap between the femoral stem and bone model is completely filled with HA clay. However, the gap is not filled only with HA granules or HA granules mixed with saline solution. In the third animal experiment, using an unloaded model, histology shows that HA clay has an osteoconductive property bridging the gap between the implant and the cortical bone without any adverse reaction. HA clay is considered a useful biomaterial to fill the gap with adequate bone ingrowth.

The effect of a composite of polyorthoester and demineralized bone on the healing of large segmental defects of the radius in rats

DEFF Research Database (Denmark)

Solheim, E; Pinholt, E M; Andersen, R

1992-01-01

The effect of a composite of demineralized bone mixed with polyorthoester on the healing of large segmental defects in the rat radius was studied. Sixty male Wistar rats were divided into four groups, A through D, and an osteoperiosteal diaphyseal defect of 50 per cent of the length of the bone....... The formation of bone in the defects was quantified with computer-assisted measurements of the area on radiographs. The host-tissue response was evaluated with light microscopy. Defects that had been filled with the composite of polyorthoester and demineralized bone or with demineralized bone alone showed...... regeneration of bone corresponding to 93.6 and 77.6 per cent of the area of the defect, respectively. Defects that had no implant or that had been filled with polyorthoester alone showed significantly less formation of bone. No inflammation was seen with light microscopy, and only traces of the polyorthoester...

Proteínas morfogenéticas ósseas associadas a osso esponjoso autógeno na reparação de falhas experimentais na calota craniana de coelhos (Oryctolagus cuniculus Bone morphogenetic proteins associated with autogenous bone graft in the reparation of calvarial experimental defects of rabbits (Oryctolagus cuniculus

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B.S. Monteiro

2007-12-01

ão determinou maior preenchimento ósseo.Aspects of bone repair were evaluated after implantation of bone morphogenetic proteins (BMP in different concentrations. They were carried by autogenous bone graft in defects created on skulls of 20 adult, young female rabbits, randomizedly divided into five experimental groups and were observed at five times. After exposure of skull bones, six bone defects on the fronto-parietal region of each animal were performed. The defect I was not filled, the II was completed filled with 3mg of autogenous bone graft and the defects III, IV, V, and VI were filled with autogenous bone graft associated with 0.5; 1; 2 and 5mg of BMP, respectively. In the post-mortem mesoscopic evaluations, it was observed that, independently of the treatment period of the defects, the bony filling began from the borders to the center, and from the botton to the surface of the lessions. The bony filling of the defect I was the smallest when compared with the others defects, in all the observation moments. It was also verified that until 2mg the higher the concentration of BMP used, better was the bone cover. Microscopically, it was verified in the first evaluations, on the seventh day, that the bony growth started from the borders and from the bottom of the lesion, with mobilization and differentiation of cells deriving from the periosteum and the meninges, respectively. In the subsequent evaluations, the osteoblastic activity also derived from "ossification islands" to ossification centers, located in the center of the flaw. The trabecular formation increased proportionally with the concentration of BMP used, and the apposition and bony organization increased proportionally with the time of observation. The presence of cartilaginous tissue was verified in all the flaws. In conclusion, the use the higher concentration of BMP did not determinate the better new bone formation. The association of BMP with autogenous bone graft contributed to the formation of new bony

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

Science.gov (United States)

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

2012-01-01

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

Treatment of intrabony defects with resorbable materials, non-resorbable materials and flap debridement.

Science.gov (United States)

Zybutz, M D; Laurell, L; Rapoport, D A; Persson, G R

2000-03-01

Different types of barriers are used in guided tissue regenerative procedures. This prospective study compared resorbable citric acid ester softened polylactic acid membranes (RM) and non-resorbable expanded polytetrafluoroethylene (ePTFE) barriers (NRM) in GTR treatment of intrabony defects. 29 subjects were randomly assigned to the RM group or NRM group. Each patient received one GTR procedure. An open flap debridement (FD) was performed at another site 2 weeks later to evaluate healing potential. Clinical treatment outcomes were finally evaluated 12 months after surgery for changes of pocket depth PD, probing attachment level PAL, and probing bone level PBL, and radiographically for bone change using standardised radiographs. No differences in healing patters after surgery were found between patients in the 2 study groups as evaluated from the FD surgical procedures. NRM treated sites showed less signs of post-surgical inflammation during the 1st 4 weeks of healing than did RM treated sites (p<0.05). GTR-treated defects in the RM group, initially 7.0+/-2.2 mm deep, showed PD reduction of 3.3+/-2.2 mm, PAL gain of 2.4+/-1.8 mm, PBL gain of 2.4+/-3.7 mm (28%) and a radiographic bone fill of 2.3+/-2.4 mm. Defects treated with the NRM exhibited PD reduction of 3.1+/-2.1 mm, PAL gain of 2.4+/-0.8 mm, PBL gain of 2.2+/-1.7 mm (25%) and a radiographic bone fill of 3.3+/-2.2 mm. All improvements were statistically significant (p<0.01) but there was no difference between RM and NRM treatments for any of the efficacy variables. The results of this study indicated that there was no clinically significant difference in treatment outcomes following GTR treatment of intrabony defects with citric acid ester softened polylactic acid membranes as compared to ePTFE barriers. The overall mean inter-proximal vertical bone defect fill at 12 months as assessed from intra-oral radiographs was 44% of the original mean defect depth. Thus, no clinically significant difference in

Electronic structure of point defects in semiconductors

International Nuclear Information System (INIS)

Bruneval, Fabien

2014-01-01

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

Similar hyaline-like cartilage repair of osteochondral defects in rabbits using isotropic and anisotropic collagen scaffolds.

Science.gov (United States)

de Mulder, Eric L W; Hannink, Gerjon; van Kuppevelt, Toin H; Daamen, Willeke F; Buma, Pieter

2014-02-01

Lesions in knee joint articular cartilage (AC) have limited repair capacity. Many clinically available treatments induce a fibrous-like cartilage repair instead of hyaline cartilage. To induce hyaline cartilage repair, we hypothesized that type I collagen scaffolds with fibers aligned perpendicular to the AC surface would result in qualitatively better tissue repair due to a guided cellular influx from the subchondral bone. By specific freezing protocols, type I collagen scaffolds with isotropic and anisotropic fiber architectures were produced. Rabbits were operated on bilaterally and two full thickness defects were created in each knee joint. The defects were filled with (1) an isotropic scaffold, (2) an anisotropic scaffold with pores parallel to the cartilage surface, and (3) an anisotropic scaffold with pores perpendicular to the cartilage surface. Empty defects served as controls. After 4 (n=13) and 12 (n=13) weeks, regeneration was scored qualitatively and quantitatively using histological analysis and a modified O'Driscoll score. After 4 weeks, all defects were completely filled with partially differentiated hyaline cartilage tissue. No differences in O'Driscoll scores were measured between empty defects and scaffold types. After 12 weeks, all treatments led to hyaline cartilage repair visualized by increased glycosaminoglycan staining. Total scores were significantly increased for parallel anisotropic and empty defects over time (phyaline-like cartilage repair. Fiber architecture had no effect on cartilage repair.

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Selection and specification criteria for fills for cut-and-fill mining

Energy Technology Data Exchange (ETDEWEB)

Thomas, E. G.

1980-05-15

Because of significant differences in placement and loading conditions, the ideal fill material for a cut-and-fill operation has different characteristics to those for a fill for a filled open stoping operation. The differing requirements of the two mining operations must be understood and accounted for in establishing fill selection and specification criteria. Within the paper, aspects of the particular requirements of cut-and-fill mining are analyzed and related to the specific fill tests and properties required. Emphasis is placed upon the role of fill in ground support, though this cannot be isolated from overall fill performance. Where appropriate, test data are introduced and areas requiring continuing research highlighted.

Simulation based mask defect repair verification and disposition

Science.gov (United States)

Guo, Eric; Zhao, Shirley; Zhang, Skin; Qian, Sandy; Cheng, Guojie; Vikram, Abhishek; Li, Ling; Chen, Ye; Hsiang, Chingyun; Zhang, Gary; Su, Bo

2009-10-01

As the industry moves towards sub-65nm technology nodes, the mask inspection, with increased sensitivity and shrinking critical defect size, catches more and more nuisance and false defects. Increased defect counts pose great challenges in the post inspection defect classification and disposition: which defect is real defect, and among the real defects, which defect should be repaired and how to verify the post-repair defects. In this paper, we address the challenges in mask defect verification and disposition, in particular, in post repair defect verification by an efficient methodology, using SEM mask defect images, and optical inspection mask defects images (only for verification of phase and transmission related defects). We will demonstrate the flow using programmed mask defects in sub-65nm technology node design. In total 20 types of defects were designed including defects found in typical real circuit environments with 30 different sizes designed for each type. The SEM image was taken for each programmed defect after the test mask was made. Selected defects were repaired and SEM images from the test mask were taken again. Wafers were printed with the test mask before and after repair as defect printability references. A software tool SMDD-Simulation based Mask Defect Disposition-has been used in this study. The software is used to extract edges from the mask SEM images and convert them into polygons to save in GDSII format. Then, the converted polygons from the SEM images were filled with the correct tone to form mask patterns and were merged back into the original GDSII design file. This merge is for the purpose of contour simulation-since normally the SEM images cover only small area (~1 μm) and accurate simulation requires including larger area of optical proximity effect. With lithography process model, the resist contour of area of interest (AOI-the area surrounding a mask defect) can be simulated. If such complicated model is not available, a simple

Influence of defects on diamond detection properties

International Nuclear Information System (INIS)

Tromson, Dominique

2000-01-01

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

Histomorphometric evaluation of bone regeneration using autogenous bone and beta-tricalcium phosphate in diabetic rabbits

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Živadinović Milka

2016-01-01

Full Text Available Background/Aim. The mechanism of impaired bone healing in diabetes mellitus includes different tissue and cellular level activities due to micro- and macrovascular changes. As a chronic metabolic disease with vascular complications, diabetes affects a process of bone regeneration as well. The therapeutic approach in bone regeneration is based on the use of osteoinductive autogenous grafts as well as osteoconductive synthetic material, like a β-tricalcium phosphate. The aim of the study was to determine the quality and quantity of new bone formation after the use of autogenous bone and β-tricalcium phosphate in the model of calvarial critical-sized defect in rabbits with induced diabetes mellitus type I. Methods. The study included eight 4-month-old Chincilla rabbits with alloxan-induced diabetes mellitus type I. In all animals, there were surgically created two calvarial bilateral defects (diameter 12 mm, which were grafted with autogenous bone and β-tricalcium phosphate (n = 4 or served as unfilled controls (n = 4. After 4 weeks of healing, animals were sacrificed and calvarial bone blocks were taken for histologic and histomorphometric analysis. Beside descriptive histologic evaluation, the percentage of new bone formation, connective tissue and residual graft were calculated. All parameters were statistically evaluated by Friedman Test and post hock Wilcoxon Singed Ranks Test with a significance of p < 0.05. Results. Histology revealed active new bone formation peripherally with centrally located connective tissue, newly formed woven bone and well incorporated residual grafts in all treated defects. Control samples showed no bone bridging of defects. There was a significantly more new bone in autogeonous graft (53% compared with β-tricalcium phosphate (30%, (p < 0.030 and control (7%, (p < 0.000 groups. A significant difference was also recorded between β-tricalcium phosphate and control groups (p < 0.008. Conclusion. In the present

Evaluation of Polyurethane Membrane as a Barrier in Treatment of Intrabony Defects

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Haghighati F

2000-05-01

Full Text Available Clinical healing following guided tissue regeneration (GTR in intrabony pockets using a"npolyurethane membrane was compared to healing following gingival flap surgery (GFS."nTen patients with adult periodontitis and the presence of intrabony defects were selected. Oral hygenic"ntreatments were performed during a 4- weeks period prior to surgery."nOne intrabony defects on each patient was randomly chosen to be treated according to the guided tissue"nregeneration (GTR procedure. The other side received the control treatment GFS. Test group received"nthe GTP treatment including polyurethane membrane after reflecting the flap and curettage of defect."nHowever, flap surgery and curettage were done in control group."nThe patients were evaluated for changes in probing depth (PD, clinical attachment level (CAL,"nrecession changes in crestai resorting, and defect bone fill. Clinical examinations were performed again 6"nmonths post operatively."nThe average of (PD, (CAL and defect depth (DD before surgery in test group was 3.23, 13.87 and 7.3"nmm respectively and in control group was 3.1, 8.9, 7.4 mm. After 6 months the average of (PD, (CAL"nand (DD was 1.69, 1.68, 3.5 mm, respectively and in control group was 1.24, 1.09, and 2.90mm."nTest group and control group showed successful results in treatment of intrabony defects. Test group"nshowed better results than control."nNo significant difference was observed between two treatment procedures from the point of view of"npocket depth reduction, attachment gain, and recession."nThe bony fill and crestai resorption results suggest similar clinical potential of GTR procedures"ncompared to GFS in treatment of intrabony pocket. However, in order to gain future insight, larger"nsamples and longer observation periods should be evaluated.

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

International Nuclear Information System (INIS)

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

1983-11-01

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

Acoustic pressure in cavity of variously sized two-dimensional sonic crystals with various filling fractions

International Nuclear Information System (INIS)

Wu Liangyu; Chen Lienwen; Liu Chiaming

2009-01-01

This study theoretically and experimentally investigates the acoustic pressure in the cavity of a 2D sonic crystal. Such crystals are composed of polymethyl methacrylate cylinders with a square array embedded in air background. The plane wave expansion method and the supercell calculation are employed to calculate the band structure and obtain the defect band. The finite element method is adopted to simulate the pressure field in the sonic crystal and calculate the pressure in the middle of the cavity as a function of frequency. The effects of sizes and filling fractions are investigated, and the quality factor of the cavity is discussed. The measured spectra and pressures in the defect of the sonic crystal demonstrate that the acoustic waves can be localized in the defect at the resonant frequency

Raman ratios on the repair of grafted surgical bone defects irradiated or not with laser (λ780 nm) or LED (λ850 nm).

Science.gov (United States)

Pinheiro, Antonio Luiz B; Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Aciole, Jouber Mateus S; de Souza, Renato Aparecido; Silveira, Landulfo

2014-09-05

This work aimed to assess biochemical changes associated to mineralization and remodeling of bone defects filled with Hydroxyapatite+Beta-Beta-tricalcium phosphate irradiated or not with 2 light sources. Ratios of intensities, band position and bandwidth of selected Raman peaks of collagen and apatites were used. Sixty male Wistar rats were divided into 6 groups subdivided into 2 subgroups (15th and 30th days). A standard surgical defect was created on one femur of each animal. In 3 groups the defects were filled with blood clot (Clot, Clot+Laser and Clot+LED groups) and in the remaining 3 groups the defects were filled with biomaterial (Biomaterial, Biomaterial+Laser and Biomaterial+LED groups). When indicated, the defects were irradiated with either Laser (λ780 nm, 70 mW, Φ∼0.4 cm(2)) or LED (λ850±10 nm, 150 mW, Φ∼0.5 cm(2)), 20 J/cm(2) each session, at 48 h intervals/2 weeks (140 J/cm(2) treatment). Following sacrifice, bone fragments were analyzed by Raman spectroscopy. Statistical analysis (ANOVA General Linear Model, pRaman ratios of selected protein matrix and phosphate and carbonate HA indicated that the use of biphasic synthetic micro-granular HA+Beta-TCP graft improved the repair of bone defects, associated or not with Laser or LED light, because of the increasing deposition of HA. Copyright © 2014 Elsevier B.V. All rights reserved.

Tissue-engineered cartilaginous constructs for the treatment of caprine cartilage defects, including distribution of laminin and type IV collagen.

Science.gov (United States)

Jeng, Lily; Hsu, Hu-Ping; Spector, Myron

2013-10-01

The purpose of this study was the immunohistochemical evaluation of (1) cartilage tissue-engineered constructs; and (2) the tissue filling cartilage defects in a goat model into which the constructs were implanted, particularly for the presence of the basement membrane molecules, laminin and type IV collagen. Basement membrane molecules are localized to the pericellular matrix in normal adult articular cartilage, but have not been examined in tissue-engineered constructs cultured in vitro or in tissue filling cartilage defects into which the constructs were implanted. Cartilaginous constructs were engineered in vitro using caprine chondrocyte-seeded type II collagen scaffolds. Autologous constructs were implanted into 4-mm-diameter defects created to the tidemark in the trochlear groove in the knee joints of skeletally mature goats. Eight weeks after implantation, the animals were sacrificed. Constructs underwent immunohistochemical and histomorphometric evaluation. Widespread staining for the two basement membrane molecules was observed throughout the extracellular matrix of in vitro and in vivo samples in a distribution unlike that previously reported for cartilage. At sacrifice, 70% of the defect site was filled with reparative tissue, which consisted largely of fibrous tissue and some fibrocartilage, with over 70% of the reparative tissue bonded to the adjacent host tissue. A novel finding of this study was the observation of laminin and type IV collagen in in vitro engineered cartilaginous constructs and in vivo cartilage repair samples from defects into which the constructs were implanted, as well as in normal caprine articular cartilage. Future work is needed to elucidate the role of basement membrane molecules during cartilage repair and regeneration.

Automatic detection of NIL defects using microscopy and image processing

KAUST Repository

Pietroy, David

2013-12-01

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

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

International Nuclear Information System (INIS)

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

2002-01-01

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

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

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Carmen L Mueller Storrer

2014-01-01

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

Quantum interference between two phonon paths and reduced heat transport in diamond lattice with atomic-scale planar defects

Science.gov (United States)

Kosevich, Yu. A.; Strelnikov, I. A.

2018-02-01

Destructive quantum interference between the waves propagating through laterally inhomogeneous layer can result in their total reflection, which in turn reduces energy flux carried by these waves. We consider the systems of Ge atoms, which fully or partly, in the chequer-wise order, fill a crystal plane in diamond-like Si lattice. We have revealed that a single type of the atomic defects, which are placed in identical positions in different unit cells in the defect crystal plane, can result in double transmission antiresonances of phonon wave packets. This new effect we relate with the complex structure of the diamond-like unit cell, which comprises two atoms in different positions and results in two distinct vibration resonances in two interfering phonon paths. We also consider the propagation of phonon wave packets in the superlatticies made of the defect planes, half-filled in the chequer-wise order with Ge atoms. We have revealed relatively broad phonon stop bands with center frequencies at the transmission antiresonances. We elaborate the equivalent analytical quasi-1D lattice model of the two phonon paths through the complex planar defect in the diamond-like lattice and describe the reduction of phonon heat transfer through the atomic-scale planar defects.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Management of segmental bony defects: the role of osteoconductive orthobiologics.

Science.gov (United States)

McKee, Michael D

2006-01-01

Our knowledge about, and the availability of, orthobiologic materials has increased exponentially in the last decade. Although previously confined to the experimental or animal-model realm, several orthobiologics have been shown to be useful in a variety of clinical situations. As surgical techniques in vascular anastomosis, soft-tissue coverage, limb salvage, and fracture stabilization have improved, the size and frequency of bony defects (commensurate with the severity of the initial injury) have increased, as well. Because all methods of managing segmental bony defects have drawbacks, a need remains for a readily available, void-filling, inexpensive bone substitute. Such a bone substitute fulfills a permissive role in allowing new bone to grow into a given defect. Such potential osteoconductive materials include ceramics, calcium sulfate or calcium phosphate compounds, hydroxyapatite, deproteinized bone, corals, and recently developed polymers. Some materials that have osteoinductive properties, such as demineralized bone matrix, also display prominent osteoconductive properties.

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

Science.gov (United States)

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

2012-04-01

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. 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. 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. In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

Repair of articular osteochondral defects of the knee joint using a composite lamellar scaffold.

Science.gov (United States)

Lv, Y M; Yu, Q S

2015-04-01

The major problem with repair of an articular cartilage injury is the extensive difference in the structure and function of regenerated, compared with normal cartilage. Our work investigates the feasibility of repairing articular osteochondral defects in the canine knee joint using a composite lamellar scaffold of nano-ß-tricalcium phosphate (ß-TCP)/collagen (col) I and II with bone marrow stromal stem cells (BMSCs) and assesses its biological compatibility. The bone-cartilage scaffold was prepared as a laminated composite, using hydroxyapatite nanoparticles (nano-HAP)/collagen I/copolymer of polylactic acid-hydroxyacetic acid as the bony scaffold, and sodium hyaluronate/poly(lactic-co-glycolic acid) as the cartilaginous scaffold. Ten-to 12-month-old hybrid canines were randomly divided into an experimental group and a control group. BMSCs were obtained from the iliac crest of each animal, and only those of the third generation were used in experiments. An articular osteochondral defect was created in the right knee of dogs in both groups. Those in the experimental group were treated by implanting the composites consisting of the lamellar scaffold of ß-TCP/col I/col II/BMSCs. Those in the control group were left untreated. After 12 weeks of implantation, defects in the experimental group were filled with white semi-translucent tissue, protruding slightly over the peripheral cartilage surface. After 24 weeks, the defect space in the experimental group was filled with new cartilage tissues, finely integrated into surrounding normal cartilage. The lamellar scaffold of ß-TCP/col I/col II was gradually degraded and absorbed, while new cartilage tissue formed. In the control group, the defects were not repaired. This method can be used as a suitable scaffold material for the tissue-engineered repair of articular cartilage defects. Cite this article: Bone Joint Res 2015;4:56-64. ©2015 The British Editorial Society of Bone & Joint Surgery.

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

Science.gov (United States)

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

2018-03-01

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

Neutron diffraction and thermoelectric properties of indium filled In{sub x}Co{sub 4}Sb{sub 12} (x = 0.05, 0.2) and indium cerium filled Ce{sub 0.05}In{sub 0.1}Co{sub 4}Sb{sub 12} skutterudites

Energy Technology Data Exchange (ETDEWEB)

Sesselmann, Andreas [Institute of Materials Research, German Aerospace Center (DLR), Linder Hoehe, 51147 Koeln (Germany); Klobes, Benedikt [Juelich Centre for Neutron Science JCNS und Peter Gruenberg Institute PGI, JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Dasgupta, Titas [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Mumbai (India); Gourdon, Olivier [Los Alamos National Laboratory, LANSCE, Los Alamos, New Mexico 87545 (United States); Hermann, Raphael [Juelich Centre for Neutron Science JCNS und Peter Gruenberg Institute PGI, JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Faculte des Sciences, Universite de Liege, 4000 Liege (Belgium); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Mueller, Eckhard [Institute of Materials Research, German Aerospace Center (DLR), Linder Hoehe, 51147 Koeln (Germany); Institute of Inorganic and Analytical Chemistry, Justus Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen (Germany)

2016-03-15

The thermoelectric properties on polycrystalline single (In) and double filled (Ce, In) skutterudites are characterized between 300 and 700 K. Powder neutron diffraction measurements of the skutterudite compositions In{sub x}Co{sub 4}Sb{sub 12} (x = 0.05, 0.2) and Ce{sub 0.05}In{sub 0.1}Co{sub 4}Sb{sub 12} as a function of temperature (12-300 K) were carried out, which gives more insight into the structural data of single and double-filled skutterudites. Results show that due to the annealing treatment, a Sb deficiency is detectable and thus verifies defects at the Sb lattice site of the skutterudite. Furthermore, we show by electron microprobe analysis that a considerable amount of indium is lost during synthesis and post-processing for the single indium filled samples, but not for the double cerium and indium skutterudite sample. In our experiments, the double-filled skutterudite is superior to the single-filled skutterudite composition due to a higher charge carrier density, a comparable lattice thermal resistivity, and a higher density of states effective mass. Furthermore, we obtained a significantly higher Einstein temperature for the double-filled skutterudite composition in comparison to the single-filled species, which reflects the high sensitivity due to filling of the void lattice position within the skutterudite crystal. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

OpenAIRE

Diószegi, Attila; Elfsberg, Jessica; Diószegi, Zoltán

2016-01-01

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

Classification of defects in honeycomb composite structure of helicopter rotor blades

International Nuclear Information System (INIS)

Balasko, M.; Svab, E.; Molnar, Gy.; Veres, I.

2005-01-01

The use of non-destructive testing methods to qualify the state of rotor blades with respect to their expected flight hours, with the aim to extend their lifetime without any risk of breakdown, is an important financial demand. In order to detect the possible defects in the composite structure of Mi-8 and Mi-24 type helicopter rotor blades used by the Hungarian Army, we have performed combined neutron- and X-ray radiography measurements at the Budapest Research Reactor. Several types of defects were detected, analysed and typified. Among the most frequent and important defects observed were cavities, holes and or cracks in the sealing elements on the interface of the honeycomb structure and the section boarders. Inhomogeneities of the resin materials (resin-rich or starved areas) at the core-honeycomb surfaces proved to be an other important point. Defects were detected at the adhesive filling, and water percolation was visualized at the sealing interfaces of the honeycomb sections. Corrosion effects, and metal inclusions have also been detected

Classification of defects in honeycomb composite structure of helicopter rotor blades

Science.gov (United States)

Balaskó, M.; Sváb, E.; Molnár, Gy.; Veres, I.

2005-04-01

The use of non-destructive testing methods to qualify the state of rotor blades with respect to their expected flight hours, with the aim to extend their lifetime without any risk of breakdown, is an important financial demand. In order to detect the possible defects in the composite structure of Mi-8 and Mi-24 type helicopter rotor blades used by the Hungarian Army, we have performed combined neutron- and X-ray radiography measurements at the Budapest Research Reactor. Several types of defects were detected, analysed and typified. Among the most frequent and important defects observed were cavities, holes and/or cracks in the sealing elements on the interface of the honeycomb structure and the section boarders. Inhomogeneities of the resin materials (resin-rich or starved areas) at the core-honeycomb surfaces proved to be an other important point. Defects were detected at the adhesive filling, and water percolation was visualized at the sealing interfaces of the honeycomb sections. Corrosion effects, and metal inclusions have also been detected.

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

Directory of Open Access Journals (Sweden)

Tomić Ljubiša D.

2015-01-01

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

Application of concentrated growth factors in reconstruction of bone defects after removal of large jaw cysts: The two cases report

Directory of Open Access Journals (Sweden)

Mirković Siniša

2015-01-01

Full Text Available Introduction. Coagulation and blood clot formation in bone defects is sometimes followed by retraction of a blood clot and serum extrusion, thus producing peripheral serum-filled spaces between bony wall and coagulum. This can result in a higher incidence of postoperative complications. Stabilization of blood coagulum, which enables successful primary healing, may be accomplished by autotransplantation, allotransplantation, xenotransplantation, or application of autologous platelet concentrate and concentrated growth factors (CGF. Case report. Two patients with large cystic lesions in the upper and lower jaw were presented. In both patients postoperative bony defects were filled with autologous fibrin rich blocks containing CGF. Postoperative course passed uneventfully. Conclusion. Application of fibrin rich blocks containing CGF is one of the possible methods for reconstruction of bone defects. CGF can be applied alone or mixed with a bone graft. The method is relatively simple, without risk of transmissible and allergic diseases and economically feasible.

Accelerated craniofacial bone regeneration through dense collagen gel scaffolds seeded with dental pulp stem cells

Science.gov (United States)

Chamieh, Frédéric; Collignon, Anne-Margaux; Coyac, Benjamin R.; Lesieur, Julie; Ribes, Sandy; Sadoine, Jérémy; Llorens, Annie; Nicoletti, Antonino; Letourneur, Didier; Colombier, Marie-Laure; Nazhat, Showan N.; Bouchard, Philippe; Chaussain, Catherine; Rochefort, Gael Y.

2016-12-01

Therapies using mesenchymal stem cell (MSC) seeded scaffolds may be applicable to various fields of regenerative medicine, including craniomaxillofacial surgery. Plastic compression of collagen scaffolds seeded with MSC has been shown to enhance the osteogenic differentiation of MSC as it increases the collagen fibrillary density. The aim of the present study was to evaluate the osteogenic effects of dense collagen gel scaffolds seeded with mesenchymal dental pulp stem cells (DPSC) on bone regeneration in a rat critical-size calvarial defect model. Two symmetrical full-thickness defects were created (5 mm diameter) and filled with either a rat DPSC-containing dense collagen gel scaffold (n = 15), or an acellular scaffold (n = 15). Animals were imaged in vivo by microcomputer tomography (Micro-CT) once a week during 5 weeks, whereas some animals were sacrificed each week for histology and histomorphometry analysis. Bone mineral density and bone micro-architectural parameters were significantly increased when DPSC-seeded scaffolds were used. Histological and histomorphometrical data also revealed significant increases in fibrous connective and mineralized tissue volume when DPSC-seeded scaffolds were used, associated with expression of type I collagen, osteoblast-associated alkaline phosphatase and osteoclastic-related tartrate-resistant acid phosphatase. Results demonstrate the potential of DPSC-loaded-dense collagen gel scaffolds to benefit of bone healing process.

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

Science.gov (United States)

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

2011-07-01

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

Bending of metal-filled carbon nanotube under electron beam irradiation

Directory of Open Access Journals (Sweden)

Abha Misra

2012-03-01

Full Text Available Electron beam irradiation induced, bending of Iron filled, multiwalled carbon nanotubes is reported. Bending of both the carbon nanotube and the Iron contained within the core was achieved using two approaches with the aid of a high resolution electron microscope (HRTEM. In the first approach, bending of the nanotube structure results in response to the irradiation of a pristine kink defect site, while in the second approach, disordered sites induce bending by focusing the electron beam on the graphite walls. The HRTEM based in situ observations demonstrate the potential for using electron beam irradiation to investigate and manipulate the physical properties of confined nanoscale structures.

Process and device for identifying nuclear reactor neutron absorber rod etancheity defect

International Nuclear Information System (INIS)

Pelletier, J.; Parrat, D.

1990-01-01

For identifying defects in the sealing of neutron absorbing rods. The rod is placed in a pressure tight enclosure filled with a chemically agressive solution. After a time the pressure is released to allow the solution come out of the rod. An analysis of the solution allows the detection of radioactive isotopes of metals which are in the rod [fr

Effect of beta-tricalcium phosphate/poly-l-lactide composites on radial bone defects of rabbit

Institute of Scientific and Technical Information of China (English)

Zhao-Jin Zhu; Hao Shen; Yong-Ping Wang; Yao Jiang; Xian-Long Zhang; Guang-Yin Yuan

2013-01-01

Objective:To explore the effect ofβ-TCP/PLLA scaffold in repairing rabbit radial bone defects. Methods: Thirty New Zealand rabbits were divided intoβ-TCP/PLLA group (group A), pure PLLA group (group B) and contrast group (group C) randomly. The rabbits were sacrificed respectively after 4, 8, 12, 24 weeks and the X-ray film was performed at the same time to evaluate the repair effect in different groups. Results:X-ray film showed there was uneven low density bone callus development in defect region after 4 weeks in group A. The defect region was filled with neonate osseous tissue completely during 12-24 weeks. X-ray score revealed that repair of bone defect results significantly better than group B and group C. Conclusions: Theβ-TCP/PLLA composite is capable of repairing radial bone bone defects.β-TCP/PLLA scaffold is significant because of rapid degradation ability, good histocompatibility and osteogenic action.

Bulk-Fill Resin Composites

DEFF Research Database (Denmark)

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

2015-01-01

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

Osteoblast CFTR inactivation reduces differentiation and osteoprotegerin expression in a mouse model of cystic fibrosis-related bone disease.

Directory of Open Access Journals (Sweden)

Michael S Stalvey

Full Text Available Low bone mass and increased fracture risk are recognized complications of cystic fibrosis (CF. CF-related bone disease (CFBD is characterized by uncoupled bone turnover--impaired osteoblastic bone formation and enhanced osteoclastic bone resorption. Intestinal malabsorption, vitamin D deficiency and inflammatory cytokines contribute to CFBD. However, epidemiological investigations and animal models also support a direct causal link between inactivation of skeletal cystic fibrosis transmembrane regulator (CFTR, the gene that when mutated causes CF, and CFBD. The objective of this study was to examine the direct actions of CFTR on bone. Expression analyses revealed that CFTR mRNA and protein were expressed in murine osteoblasts, but not in osteoclasts. Functional studies were then performed to investigate the direct actions of CFTR on osteoblasts using a CFTR knockout (Cftr-/- mouse model. In the murine calvarial organ culture assay, Cftr-/- calvariae displayed significantly less bone formation and osteoblast numbers than calvariae harvested from wildtype (Cftr+/+ littermates. CFTR inactivation also reduced alkaline phosphatase expression in cultured murine calvarial osteoblasts. Although CFTR was not expressed in murine osteoclasts, significantly more osteoclasts formed in Cftr-/- compared to Cftr+/+ bone marrow cultures. Indirect regulation of osteoclastogenesis by the osteoblast through RANK/RANKL/OPG signaling was next examined. Although no difference in receptor activator of NF-κB ligand (Rankl mRNA was detected, significantly less osteoprotegerin (Opg was expressed in Cftr-/- compared to Cftr+/+ osteoblasts. Together, the Rankl:Opg ratio was significantly higher in Cftr-/- murine calvarial osteoblasts contributing to a higher osteoclastogenesis potential. The combined findings of reduced osteoblast differentiation and lower Opg expression suggested a possible defect in canonical Wnt signaling. In fact, Wnt3a and PTH-stimulated canonical Wnt

Filling Source Feedthrus with Alumina/Molybdenum CND50 Cermet: Experimental, Theoretical, and Computational Approaches

International Nuclear Information System (INIS)

STUECKER, JOHN N.; CESARANO III, JOSEPH; CORRAL, ERICA LORRANE; SHOLLENBERGER, KIM ANN; ROACH, R. ALLEN; TORCZYNSKI, JOHN R.; THOMAS, EDWARD V.; VAN ORNUM, DAVID J.

2001-01-01

This report is a summary of the work completed in FY00 for science-based characterization of the processes used to fabricate cermet vias in source feedthrus. In particular, studies were completed to characterize the CND50 cermet slurry, characterize solvent imbibition, and identify critical via filling variables. These three areas of interest are important to several processes pertaining to the production of neutron generator tubes. Rheological characterization of CND50 slurry prepared with 94ND2 and Sandi94 primary powders were also compared. The 94ND2 powder was formerly produced at the GE Pinellas Plant and the Sandi94 is the new replacement powder produced at CeramTec. Processing variables that may effect the via-filling process were also studied and include: the effect of solids loading in the CND50 slurry; the effect of milling time; and the effect of Nuosperse (a slurry ''conditioner''). Imbibition characterization included a combination of experimental, theoretical, and computational strategies to determine solvent migration though complex shapes, specifically vias in the source feedthru component. Critical factors were determined using a controlled set of experiments designed to identify those variables that influence the occurrence of defects within the cermet filled via. These efforts were pursued to increase part production reliability, understand selected fundamental issues that impact the production of slurry-filled parts, and validate the ability of the computational fluid dynamics code, GOMA, to simulate these processes. Suggestions are made for improving the slurry filling of source feedthru vias

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

Science.gov (United States)

Yilmaz, Ayca; Helvacioglu-Yigit, Dilek; Gur, Cansu; Ersev, Handan; Kiziltas Sendur, Gullu; Avcu, Egemen; Baydemir, Canan; Abbott, Paul Vincent

2017-01-01

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

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Science.gov (United States)

2010-07-01

... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.72 Disposal of excess spoil: Valley fill/head-of-hollow fills.... Uncontrolled surface drainage may not be directed over the outslope of the fill. (2) Runoff from areas above the fill and runoff from the surface of the fill shall be diverted into stabilized diversion channels...

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

Directory of Open Access Journals (Sweden)

Cassio Eduardo Raposo-Amaral

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Kit Fook Liu

2014-01-01

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

Sodium fill of FFTF

International Nuclear Information System (INIS)

Waldo, J.B.; Greenwell, R.K.; Keasling, T.A.; Collins, J.R.; Klos, D.B.

1980-02-01

With construction of the Fast Flux Test Facility (FFTF) completed, the first major objective in the startup program was to fill the sodium systems. A sodium fill sequence was developed to match construction completion, and as systems became available, they were inerted, preheated, and filled with sodium. The secondary sodium systems were filled first while dry refueling system testing was in progress in the reactor vessel. The reactor vessel and the primary loops were filled last. This paper describes the methods used and some of the key results achieved for this major FFTF objective

GPR signal analysis of post-tensioned prestressed concrete girder defects

Science.gov (United States)

Liu, Sixin; Weng, Changnian; Jiao, Pengfei; Wang, Fei; Fu, Lei; Meng, Xu; Lei, Linlin

2013-06-01

The accurate inspection of the duct condition in post-tensioned prestressed concrete (PPC) is an essential part of GPR concrete inspection. The purpose is to inspect the grouting condition of the ducts where the strands are located, to find out if there is a void in the ducts, and if any water exists. In order to investigate the radar image characteristics of different PPC duct defects, a number of model girders were manufactured. Three major ducts are included in our study: (1) well grouted and no void (normal condition); (2) the duct is half filled, and the void is filled by water or air; and (3) the duct is not filled at all, and the duct is water or air filled. The data corresponding to seven different situations are acquired and processed. It is found that the radar can detect the first interface in the duct, and the detailed structure inside the duct cannot be ‘seen’ from the images directly. Characteristic curves greatly help the interpretation. A completely void duct is the easiest to differentiate from the others. The signature for this situation is characterized by a strong and clear reflection interface which becomes weaker as the void is water filled. The normal condition shows the weakest reflection interface. As for the half void situation, the front scan shows a similar result to the normal condition whether it is water or air filled, and the back scan shows similar features to the completely void situation. The experiment and analysis is helpful and instructive for practical engineering inspection.

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

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Yiwen Wang

2015-12-01

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

About Dental Amalgam Fillings

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

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

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Mittlmeier T

2012-06-01

Full Text Available Christoph Harms,1 Kai Helms,1 Tibor Taschner,1 Ioannis Stratos,1 Anita Ignatius,5 Thomas Gerber,2 Solvig Lenz,3 Stefan Rammelt,6 Brigitte Vollmar,4 Thomas Mittlmeier11Department of Trauma and Reconstructive Surgery, 2Department for Materials Research and Nanostructures, Institute for Physics, 3Department of Oral and Maxillofacial Plastic Surgery, 4Institute for Experimental Surgery, University of Rostock, Rostock, 5Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, 6Clinic of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Dresden, GermanyAbstract: The synthetic material Nanobone® (hydroxyapatite nanocrystallines embedded in a porous silica gel matrix was examined in vivo using a standardized bone defect model in the ovine tibial metaphysis. A standardized 6 × 12 × 24-mm bone defect was created below the articular surface of the medial tibia condyles on both hind legs of 18 adult sheep. The defect on the right side was filled with Nanobone®, while the defect on the contralateral side was left empty. The tibial heads of six sheep were analyzed after 6, 12, and 26 weeks each. The histological and radiological analysis of the defect on the control side did not reveal any bone formation after the total of 26 weeks. In contrast, the microcomputed tomography analysis of the defect filled with Nanobone® showed a 55%, 72%, and 74% volume fraction of structures with bone density after 6, 12, and 26 weeks, respectively. Quantitative histomorphological analysis after 6, and 12 weeks revealed an osteoneogenesis of 22%, and 36%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity. Nanobone® appears to be a highly potent bone substitute material with osteoconductive properties in a loaded large animal defect model, supporting the potential use of Nanobone® also in

Effects of annulus defects and implantation of poly(lactic-co-glycolic acid) (PLGA)/fibrin gel scaffolds on nerves ingrowth in a rabbit model of annular injury disc degeneration.

Science.gov (United States)

Xin, Long; Xu, Weixing; Yu, Leijun; Fan, Shunwu; Wang, Wei; Yu, Fang; Wang, Zhenbin

2017-05-12

Growth of nerve fibers has been shown to occur in a rabbit model of intravertebral disc degeneration (IVD) induced by needle puncture. As nerve growth may underlie the process of chronic pain in humans affected by disc degeneration, we sought to investigate the factors underlying nerve ingrowth in a minimally invasive annulotomy rabbit model of IVD by comparing the effects of empty disc defects with those of defects filled with poly(lactic-co-glycolic acid)/fibrin gel (PLGA) plugs. New Zealand white rabbits (n = 24) received annular injuries at three lumbar levels (L3/4, L4/5, and L5/6). The discs were randomly assigned to four groups: (a) annular defect (1.8-mm diameter; 4-mm depth) by mini-trephine, (b) annular defect implanted with a PLGA scaffold containing a fibrin gel, (c) annular puncture by a 16G needle (5-mm depth), and (d) uninjured L2/3 disc (control). Disc degeneration was evaluated by radiography, MRI, histology, real-time PCR, and analysis of proteoglycan (PG) content. Nerve ingrowth into the discs was assessed by immunostaining with the nerve marker protein gene product 9.5. Injured discs showed a progressive disc space narrowing with significant disc degeneration and proteoglycan loss, as confirmed by imaging results, molecular and compositional analysis, and histological examinations. In 16G punctured discs, nerve ingrowth was observed on the surface of scar tissue. In annular defects, nerve fibers were found to be distributed along small fissures within the fibrocartilaginous-like tissue that filled the AF. In discs filled with PLGA/ fibrin gel, more nerve fibers were observed growing deeper into the inner AF along the open annular track.  In addition, innervations scores showed significantly higher than those of punctured discs and empty defects. A limited vascular proliferation was found in the injured sites and regenerated tissues. Nerve ingrowth was significantly higher in PLGA/fibrin-filled discs than in empty defects. Possible

Radiographic evaluation of using Persian Gulf coral powder effect on bone healing defects in rabbits

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Mehdi Marjani

2011-11-01

Full Text Available Background: ‍Considering the fact that research on the marine products and creatures, in particular coral, has started just in the past decade and more attentions are focused on the benefits of this material, it has been decided to utilize the coral native to Persian Gulf as oral powder to heal tibia bone defect in rabbit. Methods: In this experimental study 18 New Zealander rabbits weighing 2.5-3 kg were categorized randomly in 3 groups (control, oral calcium powder and oral coral powder group of 6 rabbits. For inducing the defect, the first 3rd part of tibial bone was blunt dissected. A whole with the depth of 0.6-0.8 mm and diameter of 4 mm was produced in all 3 groups in the same style. The Calcium group was treated daily with 1150 mg calcium powder, coral group received 1220 mg of coral powder and control group were kept under standard condition. Course of treatment was 2 months and on days 0,10,20,30,40,50,63 the animals were evaluated for healing criteria such as filling the defects, density, external callus formation and intercortical callus. Results: Radiologic parameters indicates that filling defect, density, external and inter cortical callus and absorption for animals receiving coral is better than that of control and calcium group (P<0/05. Conclusion: In conclusion, by oral administration of Persian Gulf coral powder results increasing the rate of bone formation. Finally for human use, these results must be evaluated more in clinical studies.

Evaluation of bioactive glass and demineralized freeze dried bone allograft in the treatment of periodontal intraosseous defects: A comparative clinico-radiographic study

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Kishore Kumar Katuri

2013-01-01

Full Text Available Aim: The purpose of this study was to evaluate the efficacy of demineralized freeze dried bone allograft (DFDBA and bioactive glass by clinically and radiographically in periodontal intrabony defects for a period of 12 months. Materials and Methods: Ten systemically healthy patients diagnosed with chronic periodontitis, with radiographic evidence of at least a pair of contralateral vertical osseous defects were included in this study. Defect on one-side is treated with DFDBA and the other side with bioactive glass. Clinical and radiographic measurements were made at baseline 6 month and 12 month after the surgery. Results: Compared to baseline, the 12 month results indicated that both treatment modalities resulted in significant changes in all clinical parameters (gingival index, probing depth, clinical attachment level (CAL and radiographic parameters (bone fill; P < 0.001FNx01. However, sites treated with DFDBA exhibited statistically significantly more changes compared to the bioactive glass in probing depth reduction (2.5 ± 0.1 mm vs. 1.8 ± 0.1 mm CAL gain 2.4 ± 0.1 mm versus 1.7 ± 0.2 mm; ( P < 0.001FNx01. At 12 months, sites treated with bioactive glass exhibited 56.99% bone fill and 64.76% bone fill for DFDBA sites, which is statistically significant ( P < 0.05FNx01. Conclusion: After 12 months, there was a significant difference between the two materials with sites grafted with DFDBA showing better reduction in probing pocket depth, gain in CAL and a greater percentage of bone fill when compared to that of bioactive glass.

Defects and defect processes in nonmetallic solids

CERN Document Server

Hayes, W

2004-01-01

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

Influence of the λ780nm laser light on the repair of surgical bone defects grafted or not with biphasic synthetic micro-granular hydroxylapatite+Beta-Calcium triphosphate.

Science.gov (United States)

Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Guarda, Milena G; Aciole, Jouber Mateus S; dos Santos, Jean Nunes; Pinheiro, Antonio Luiz B

2014-02-05

The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through histological analysis The aim of this study was to assess, by light microscopy, the repair of bone defects grafted or not with biphasic synthetic micro-granular Calcium hydroxyapatite (HA)+Beta-TCP associated or not with Laser phototherapy - LPT (λ780nm). Forty rats were divided into 4 groups each subdivided into 2 subgroups according to the time of sacrifice (15 and 30days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of Clot group the defect was filled only by blood clot, on Laser group the defect filled with the clot was further irradiated. On animals of Biomaterial and Laser+Biomaterial groups the defect was filled by biomaterial and the last one was further irradiated (λ780nm, 70mW, spot size∼0.4cm(2), 20J/cm(2)-session, 140J/cm(2)-treatment) in four points around the defect at 48-h intervals and repeated for 2weeks. At both 15th and 30th days following sacrifice, samples were taken and analyzed by light microscopy. Many similarities were observed histologically between groups on regards bone reabsorption and neoformation, inflammatory infiltrate and collagen deposition. The criterion degree of maturation, marked by the presence of basophilic lines, indicated that the use of LPT associated with HA+Beta TCP graft, resulted in more advanced stage of bone repair at the end of the experiment. Copyright © 2014 Elsevier B.V. All rights reserved.

Raman study of the repair of surgical bone defects grafted with biphasic synthetic microgranular HA + β-calcium triphosphate and irradiated or not with λ780 nm laser.

Science.gov (United States)

Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Barbosa, Artur Felipe S; Santos, Nicole R; Aciole, Jouber Mateus S; Souza, Caroline Mathias C; Pinheiro, Antonio Luiz B; Silveira, Landulfo

2014-09-01

The treatment of bone loss due to different etiologic factors is difficult, and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (∼ 960, ∼ 1,070, and ∼ 1,077 cm(-1)) and organic (∼ 1,454 and ∼ 1,666 cm(-1)) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of killing (15 and 30 days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of group Clot, the defect was filled only by blood clot; on group Laser, the defect filled with the clot was further irradiated. On animals of groups Biomaterial and Laser + Biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, Φ ∼ 0.4 cm(2), 20 J/cm(2) session, 140 J/cm(2) treatment) in four points around the defect at 48-h intervals and repeated for 2 weeks. At both 15th and 30th day following killing, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensities of both inorganic and organic contents were higher on group Laser + Biomaterial. It is concluded that the use of laser phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of calcium hydroxyapatite measured by Raman spectroscopy.

Effects of local defect growth in direct-drive cryogenic implosions on OMEGA

Energy Technology Data Exchange (ETDEWEB)

Igumenshchev, I. V.; Shmayda, W. T.; Harding, D. R.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Goncharov, V. N. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623 (United States); Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623 (United States); Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623 (United States)

2013-08-15

Spherically symmetric, low-adiabat (adiabat α ≲ 3) cryogenic direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1995)] yield less than 10% of the neutrons predicted in one-dimensional hydrodynamic simulations. Two-dimensional hydrodynamic simulations suggest that this performance degradation can be explained assuming perturbations from isolated defects of submicron to tens-of-micron scale on the outer surface or inside the shell of implosion targets. These defects develop during the cryogenic filling process and typically number from several tens up to hundreds for each target covering from about 0.2% to 1% of its surface. The simulations predict that such defects can significantly perturb the implosion and result in the injection of about 1 to 2 μg of the hot ablator (carbon-deuterium) and fuel (deuterium-tritium) materials from the ablation surface into the targets. Both the hot mass injection and perturbations of the shell reduce the final shell convergence ratio and implosion performance. The injected carbon ions radiatively cool the hot spot, reducing the fuel temperature, and further reducing the neutron yield. The negative effect of local defects can be minimized by decreasing the number and size of these defects and/or using more hydrodynamically stable implosion designs with higher shell adiabat.

Defects and oxidation of group-III monochalcogenide monolayers

Science.gov (United States)

Guo, Yu; Zhou, Si; Bai, Yizhen; Zhao, Jijun

2017-09-01

Among various two-dimensional (2D) materials, monolayer group-III monochalcogenides (GaS, GaSe, InS, and InSe) stand out owing to their potential applications in microelectronics and optoelectronics. Devices made of these novel 2D materials are sensitive to environmental gases, especially O2 molecules. To address this critical issue, here we systematically investigate the oxidization behaviors of perfect and defective group-III monochalcogenide monolayers by first-principles calculations. The perfect monolayers show superior oxidation resistance with large barriers of 3.02-3.20 eV for the dissociation and chemisorption of O2 molecules. In contrast, the defective monolayers with single chalcogen vacancy are vulnerable to O2, showing small barriers of only 0.26-0.36 eV for the chemisorption of an O2 molecule. Interestingly, filling an O2 molecule to the chalcogen vacancy of group-III monochalcogenide monolayers could preserve the electronic band structure of the perfect system—the bandgaps are almost intact and the carrier effective masses are only moderately disturbed. On the other hand, the defective monolayers with single vacancies of group-III atoms carry local magnetic moments of 1-2 μB. These results help experimental design and synthesis of group-III monochalcogenides based 2D devices with high performance and stability.

Establishment of a new pull-out strength testing method to quantify early osseointegration-An experimental pilot study.

Science.gov (United States)

Nonhoff, J; Moest, T; Schmitt, Christian Martin; Weisel, T; Bauer, S; Schlegel, K A

2015-12-01

The animal study aims to evaluate a new experimental model for measuring sole the influence of the surface characteristics independent from implant macro-design on the level of osseointegration by registering the pull-out strength needed for removal of experimental devices with different surfaces from artificial defects. Seventy-two test bodies (36 with the FRIADENT(®) plus surface, 36 with the P15/HAp biofunctionalized surface) were inserted in six adult domestic pigs with artificial calvarial defects. The experimental devices were designed to fit in the defects leaving a gap between the test body and the local bone. After 21 days of healing, the animals were sacrificed and the test bodies were pulled out with a standardised reproducible pull-out device measuring the pull-out strength. The pull-out strength for both groups was compared. Twenty-one days after insertion a mean force of 412 ± 142 N for the P15/HAp group and 183 ± 105 N for the FRIADENT(®) plus group was measured for the removal of the specimens from the calvarial bone. The difference between the groups was statistically significant (p implant surfaces on the early stage of osseointegration. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

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

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Ayca Yilmaz

2017-01-01

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

Human and murine very small embryonic-like cells represent multipotent tissue progenitors, in vitro and in vivo.

Science.gov (United States)

Havens, Aaron M; Sun, Hongli; Shiozawa, Yusuke; Jung, Younghun; Wang, Jingcheng; Mishra, Anjali; Jiang, Yajuan; O'Neill, David W; Krebsbach, Paul H; Rodgerson, Denis O; Taichman, Russell S

2014-04-01

The purpose of this study was to determine the lineage progression of human and murine very small embryonic-like (HuVSEL or MuVSEL) cells in vitro and in vivo. In vitro, HuVSEL and MuVSEL cells differentiated into cells of all three embryonic germ layers. HuVSEL cells produced robust mineralized tissue of human origin compared with controls in calvarial defects. Immunohistochemistry demonstrated that the HuVSEL cells gave rise to neurons, adipocytes, chondrocytes, and osteoblasts within the calvarial defects. MuVSEL cells were also able to differentiate into similar lineages. First round serial transplants of MuVSEL cells into irradiated osseous sites demonstrated that ∼60% of the cells maintained their VSEL cell phenotype while other cells differentiated into multiple tissues at 3 months. Secondary transplants did not identify donor VSEL cells, suggesting limited self renewal but did demonstrate VSEL cell derivatives in situ for up to 1 year. At no point were teratomas identified. These studies show that VSEL cells produce multiple cellular structures in vivo and in vitro and lay the foundation for future cell-based regenerative therapies for osseous, neural, and connective tissue disorders.

Safety Evaluation of a Bioglass–Polylactic Acid Composite Scaffold Seeded with Progenitor Cells in a Rat Skull Critical-Size Bone Defect

Science.gov (United States)

El-Kady, Abeer M.; Arbid, Mahmoud S.; Abd El-Hady, Bothaina M.; Marzi, Ingo; Seebach, Caroline

2014-01-01

Treating large bone defects represents a major challenge in traumatic and orthopedic surgery. Bone tissue engineering provides a promising therapeutic option to improve the local bone healing response. In the present study tissue biocompatibility, systemic toxicity and tumorigenicity of a newly developed composite material consisting of polylactic acid (PLA) and 20% or 40% bioglass (BG20 and BG40), respectively, were analyzed. These materials were seeded with mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) and tested in a rat calvarial critical size defect model for 3 months and compared to a scaffold consisting only of PLA. Serum was analyzed for organ damage markers such as GOT and creatinine. Leukocyte count, temperature and free radical indicators were measured to determine the degree of systemic inflammation. Possible tumor occurrence was assessed macroscopically and histologically in slides of liver, kidney and spleen. Furthermore, the concentrations of serum malondialdehyde (MDA) and sodium oxide dismutase (SOD) were assessed as indicators of tumor progression. Qualitative tissue response towards the implants and new bone mass formation was histologically investigated. BG20 and BG40, with or without progenitor cells, did not cause organ damage, long-term systemic inflammatory reactions or tumor formation. BG20 and BG40 supported bone formation, which was further enhanced in the presence of EPCs and MSCs. This investigation reflects good biocompatibility of the biomaterials BG20 and BG40 and provides evidence that additionally seeding EPCs and MSCs onto the scaffold does not induce tumor formation. PMID:24498345

Platelet rich fibrin and alloplast in the treatment of intrabony defect

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Saurav Panda

2014-01-01

Full Text Available Periodontal regeneration is defined as the reproduction or reconstitution of a lost or injured part to restore the architecture and function of the periodontium. The ultimate goal of periodontal therapy is to regenerate the lost periodontal tissues caused by periodontitis. The most positive outcome of periodontal regenerative procedures in intra bony defect has been achieved with bone grafts. For complete regeneration, delivery of growth factors in a local environment holds a great deal in adjunct to bone grafts. Platelet rich fibrin (PRF is considered as second generation platelet concentrate, consisting of viable platelets, releasing various growth factors. Hence, this case report aims to investigate the clinical and radiological (bone fill effectiveness of autologous PRF along with the use of alloplastic bone mineral in the treatment of intra bony defects.

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

African Journals Online (AJOL)

2010-06-29

Jun 29, 2010 ... Neurosurgery and 1Department of Pathology, Usmanu Dan. Fodiyo University, Teaching Hospital Sokoto, Nigeria. Address for correspondence: Dr. N. J. Ismail, Department of. Neurosurgery, Regional Center for Neurosurgery, Usmanu ... with complete tumor excision, and frontal cranioplasty with antibiotic ...

Structural Defects in Donor-Acceptor Blends: Influence on the Performance of Organic Solar Cells

Science.gov (United States)

Sergeeva, Natalia; Ullbrich, Sascha; Hofacker, Andreas; Koerner, Christian; Leo, Karl

2018-02-01

Defects play an important role in the performance of organic solar cells. The investigation of trap states and their origin can provide ways to further improve their performance. Here, we investigate defects in a system composed of the small-molecule oligothiophene derivative DCV5T-Me blended with C60 , which shows power conversion efficiencies above 8% when used in a solar cell. From a reconstruction of the density of trap states by impedance spectroscopy, we obtain a Gaussian distribution of trap states with Et=470 meV below the electron transport level, Nt=8 ×1014 cm-3 , and σt=41 meV . From Voc vs illumination intensity and open-circuit corrected charge carrier extraction measurements, we find that these defects lead to trap-assisted recombination. Moreover, drift-diffusion simulations show that the trap states decrease the fill factor by 10%. By conducting degradation measurements and varying the blend ratio, we find that the observed trap states are structural defects in the C60 phase due to the distortion of the natural morphology induced by the mixing.

Bone regeneration potential of stem cells derived from periodontal ligament or gingival tissue sources encapsulated in RGD-modified alginate scaffold.

Science.gov (United States)

Moshaverinia, Alireza; Chen, Chider; Xu, Xingtian; Akiyama, Kentaro; Ansari, Sahar; Zadeh, Homayoun H; Shi, Songtao

2014-02-01

Mesenchymal stem cells (MSCs) provide an advantageous alternative therapeutic option for bone regeneration in comparison to current treatment modalities. However, delivering MSCs to the defect site while maintaining a high MSC survival rate is still a critical challenge in MSC-mediated bone regeneration. Here, we tested the bone regeneration capacity of periodontal ligament stem cells (PDLSCs) and gingival mesenchymal stem cells (GMSCs) encapsulated in a novel RGD- (arginine-glycine-aspartic acid tripeptide) coupled alginate microencapsulation system in vitro and in vivo. Five-millimeter-diameter critical-size calvarial defects were created in immunocompromised mice and PDLSCs and GMSCs encapsulated in RGD-modified alginate microspheres were transplanted into the defect sites. New bone formation was assessed using microcomputed tomography and histological analyses 8 weeks after transplantation. Results confirmed that our microencapsulation system significantly enhanced MSC viability and osteogenic differentiation in vitro compared with non-RGD-containing alginate hydrogel microspheres with larger diameters. Results confirmed that PDLSCs were able to repair the calvarial defects by promoting the formation of mineralized tissue, while GMSCs showed significantly lower osteogenic differentiation capability. Further, results revealed that RGD-coupled alginate scaffold facilitated the differentiation of oral MSCs toward an osteoblast lineage in vitro and in vivo, as assessed by expression of osteogenic markers Runx2, ALP, and osteocalcin. In conclusion, these results for the first time demonstrated that MSCs derived from orofacial tissue encapsulated in RGD-modified alginate scaffold show promise for craniofacial bone regeneration. This treatment modality has many potential dental and orthopedic applications.

A device for tracking-down the defective fuel rods in a reactor

International Nuclear Information System (INIS)

Preda, Marin; Ciocanescu, Marin; Barbos, Dumitru; Rogociu, Ioan

2008-01-01

The paper gives first the fuel element description and its operation. If a cladding defect arises, some of the fission isotopes pass into the primary cooling system and, as these isotopes are extremely radio-active, the danger of primary cooling system contamination occurs what entails expensive decontamination operations. For identification of the bundle containing the defective pins a simple, modular device was designed and made. It works by pointing-out the bundle(s) which has at least one defective fuel pin. After tracking, the fuel bundle is picked-up from the core and searching is continued to point-out the defective pin inside post-irradiation-hot cells. For dosimetric survey in the reactor hall, an aerosol detector was used. When an accident arises the released noble gases will be detected by this detector. The detector can give no information where the damage is located for one of the fuel pins inside the irradiation devices (loop or capsule) can also get defective and consequently it can release radioactive noble gases in the reactor hall. For avoiding this a radioactive survey device for core cooling agent was mounted by the primary cooling system. The device for defective fuel rod identification in the nuclear reactor is composed of the following components: - a device for water sampling from the fuel bundle; - a suction valve; - a handling tool; - an electric pump; - ionic filters; - a flexible hose. When fission isotopes arise in primary cooling system, the device is brought to the edge of the reactor pool in a sharp positioning. By means of the handling tool the sampling device is inserted at the top of the fuel bundle. The suction inlet circuit and the electric pump are filled with pool water, and after that the ionic filter and outlet circuit are filled also. The electric pump is actuated and the following circuit is operated: fuel bundle, electric pump, ionic filter, pool. For avoiding the overheating of the pump, part of the flow is by

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

Directory of Open Access Journals (Sweden)

Y V Nagarjuna Reddy

2016-01-01

Full Text Available 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

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

2013-09-01

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. 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. 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). 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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-15

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

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

Science.gov (United States)

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

2012-09-01

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

Effect of biphasic calcium phosphate nanocomposite on healing of surgically created alveolar bone defects in beagle dogs

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Wang, Lanlei; Guan, Aizhong; Shi, Han; Chen, Yangxi; Liao, Yunmao

2009-09-01

The aim of the present study was to investigate the effect of porous biphasic calcium phosphate nanocomposite (nanoBCP) scaffolds bioceramic. Alveolar bone defects were surgically created bilaterally at the buccal aspects of the upper second premolar in fourteen beagle dogs. After root conditioning with ethylenediaminetetraacetate (EDTA), nanoBCP was randomly filled in the defects and nothing was put into the contralaterals as controls. Dogs were killed at the 12th weeks. Histological observations were processed through a light microscopy. The results revealed that a great amount of functional periodontal fissures formed in the defects in the nanoBCP groups while minimal bone took shape in the controls. In this study, nanoBCP has proved to work well as a biocompatible and osteoconductive scaffold material to promote periodontal regeneration effectively.

Autogenous bone particle/titanium fiber composites for bone regeneration in a rabbit radius critical-size defect model.

Science.gov (United States)

Xie, Huanxin; Ji, Ye; Tian, Qi; Wang, Xintao; Zhang, Nan; Zhang, Yicai; Xu, Jun; Wang, Nanxiang; Yan, Jinglong

2017-11-01

To explore the effects of autogenous bone particle/titanium fiber composites on repairing segmental bone defects in rabbits. A model of bilateral radial bone defect was established in 36 New Zealand white rabbits which were randomly divided into 3 groups according to filling materials used for bilaterally defect treatment: in group C, 9 animal bone defect areas were prepared into simple bilateral radius bone defect (empty sham) as the control group; 27 rabbits were used in groups ABP and ABP-Ti. In group ABP, left defects were simply implanted with autogenous bone particles; meanwhile, group ABP-Ti animals had right defects implanted with autogenous bone particle/titanium fiber composites. Animals were sacrificed at 4, 8, and 12 weeks, respectively, after operation. Micro-CT showed that group C could not complete bone regeneration. Bone volume to tissue volume values in group ABP-Ti were better than group ABP. From histology and histomorphometry Groups ABP and ABP-Ti achieved bone repair, the bone formation of group ABP-Ti was better. The mechanical strength of group ABP-Ti was superior to that of other groups. These results confirmed the effectiveness of autologous bone particle/titanium fiber composites for promoting bone regeneration and mechanical strength.

Wound healing of osteotomy defects prepared with piezo or conventional surgical instruments: a pilot study in rabbits.

Science.gov (United States)

Ma, Li; Mattheos, Nikos; Sun, Yan; Liu, Xi Ling; Yip Chui, Ying; Lang, Niklaus Peter

2015-08-01

The aim of the present study was to evaluate and compare the wound-healing process following osteotomies performed with either conventional rotary burs or piezoelectric surgery in a rabbit model. Two types of osteotomy window defects of the nasal cavities were prepared on the nasal bone of 16 adult New Zealand white rabbits with either a conventional rotary bur or piezo surgery. The defects were covered with a resorbable membrane. Four animals were killed at 1, 2, 3, and 5 weeks after the surgical procedure, respectively. Histological and morphometric evaluations were performed to assess the volumetric density of various tissue components: the blood clot, vascularized structures, provisional matrix, osteoid, mineralized bone, bone debris, residual tissue, and old bone. Significantly more bone debris was found at 1 week in the conventionally-prepared defects compared to the piezo surgically-prepared defects. At 2 and 3 weeks, a newly-formed hard tissue bridge, mainly composed of woven bone, was seen; however, no statistically-significant differences were observed. At 5 weeks, the defects were completely filled with newly-formed bone. The defects prepared by piezo surgery showed a significantly decreased proportion of bone debris at 1 week, compared to conventional rotary bur defect. © 2014 Wiley Publishing Asia Pty Ltd.

Electronic structure and optical properties of N vacancy and O filling on n-GaN (0001) surface

Science.gov (United States)

Lu, Feifei; Liu, Lei; Xia, Sihao; Diao, Yu; Feng, Shu

2018-06-01

In the X-ray photoelectron spectroscopy experiment, we observed that the valence band spectrum of the n-GaN (0001) surface appeared a bump near 1.9 eV after Ar etching and the N/Ga ratio became smaller, while the bump disappeared upon exposure to air. In order to analyze this phenomenon theoretically, we mainly study the electronic structure and optical properties of n-GaN (0001) surface with N vacancy and filled with O atom based on the first principles of density functional theory. The results suggest that the n-GaN (0001) surface exhibits semi-metallic property. The introduction of N vacancy reduces the n-type conductivity, whereas the filling of O atom enhances conductivity. The density of state near -1.9eV shows a good agreement between the clean n-type surface and the O-atom-filled surface, while the N vacancy surface has a higher density of states, which is similar to the experimentally observed phenomenon. It is also found that the existence of N vacancy reduces the photoemission properties of the n-GaN (0001) surface and the filling of O atom alleviates the defect caused by vacancy. This study shows that N vacancy increases the doping difficulty of n-type GaN films, however, the filling of O atom may compensate for the diminished photoelectric properties induced by N vacancy and be conducive to prepare high-performance optoelectronic devices with the contact of n-GaN and metal.

Operation feedback of hydrogen filling station

International Nuclear Information System (INIS)

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

2004-01-01

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

Radiographic and histological study of perennial bone defect repair in rat calvaria after treatment with blocks of porous bovine organic graft material.

Science.gov (United States)

Marins, Lucele Vieira; Cestari, Tania Mary; Sottovia, André Dotto; Granjeiro, José Mauro; Taga, Rumio

2004-03-01

Over the last few years, various bone graft materials of bovine origin to be used in oromaxillofacial surgeries have entered the market. In the present study, we determined the capacity of a block organic bone graft material (Gen-ox, Baumer SA, Brazil) prepared from bovine cancellous bone to promote the repair of critical size bone injuries in rat calvaria. A transosseous defect measuring approximately 8mm in diameter was performed with a surgical trephine in the parietal bone of 25 rats. In 15 animals, the defects were filled with a block of graft material measuring 8mm in diameter and soaked in the animal's own blood, and in the other 10 animals the defects were only filled with blood clots. The calvariae of rats receiving the material were collected 1, 3 and 6 months after surgery, and those of animals receiving the blood clots were collected immediately and 6 months after surgery. During surgery, the graft material was found to be of easy handling and to adapt perfectly to the receptor bed after soaking in blood. The results showed that, in most animals treated, the material was slowly resorbed and served as a space filling and maintenance material, favoring angiogenesis, cell migration and adhesion, and bone neoformation from the borders of the lesion. However, a foreign body-type granulomatous reaction, with the presence of numerous giant cells preventing local bone neoformation, was observed in two animals of the 1-month subgroup and in one animal of the 3-month subgroup. These cases were interpreted as resulting from the absence of demineralization and the lack of removal of potential antigen factors during production of the biomaterial. We conclude that, with improvement in the quality control of the material production, block organic bone matrix will become a good alternative for bone defect repair in the oromaxillofacial region due to its high osteoconductive capacity.

Droplet Measurement below Single-Layer Grid Fill

Directory of Open Access Journals (Sweden)

Vitkovic Pavol

2016-01-01

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

Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association with Mayer-Rokitansky-Küster-Hauser syndrome in co-occurrence

DEFF Research Database (Denmark)

Bjørsum-Meyer, Thomas; Herlin, Morten; Qvist, Niels

2016-01-01

Background: The vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome are rare conditions. We aimed to present two cases with the vertebral defect, anal atresia, cardiac...... defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser co-occurrence from our local surgical center and through a systematic literature search detect published cases. Furthermore, we aimed to collect existing knowledge...... in the embryopathogenesis and genetics in order to discuss a possible link between the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome. Case presentation: Our first case was a white girl...

Uninduced adipose-derived stem cells repair the defect of full-thickness hyaline cartilage.

Science.gov (United States)

Zhang, Hai-Ning; Li, Lei; Leng, Ping; Wang, Ying-Zhen; Lv, Cheng-Yu

2009-04-01

To testify the effect of the stem cells derived from the widely distributed fat tissue on repairing full-thickness hyaline cartilage defects. Adipose-derived stem cells (ADSCs) were derived from adipose tissue and cultured in vitro. Twenty-seven New Zealand white rabbits were divided into three groups randomly. The cultured ADSCs mixed with calcium alginate gel were used to fill the full-thickness hyaline cartilage defects created at the patellafemoral joint, and the defects repaired with gel or without treatment served as control groups. After 4, 8 and 12 weeks, the reconstructed tissue was evaluated macroscopically and microscopically. Histological analysis and qualitative scoring were also performed to detect the outcome. Full thickness hyaline cartilage defects were repaired completely with ADSCs-derived tissue. The result was better in ADSCs group than the control ones. The microstructure of reconstructed tissue with ADSCs was similar to that of hyaline cartilage and contained more cells and regular matrix fibers, being better than other groups. Plenty of collagen fibers around cells could be seen under transmission electron microscopy. Statistical analysis revealed a significant difference in comparison with other groups at each time point (t equal to 4.360, P less than 0.01). These results indicate that stem cells derived from mature adipose without induction possess the ability to repair cartilage defects.

Filling a Conical Cavity

Science.gov (United States)

Nye, Kyle; Eslam-Panah, Azar

2016-11-01

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

The reverse sural artery fasciomusculocutaneous flap for small lower-limb defects: the use of the gastrocnemius muscle cuff as a plug for small bony defects following debridement of infected/necrotic bone.

Science.gov (United States)

Al-Qattan, M M

2007-09-01

The reverse sural artery fasciomusculocutaneous flap is a modification of the original fasciocutaneous flap in which a midline gastrocnemius muscle cuff around the buried sural pedicle is included in the flap. This modification was done to improve the blood supply of the distal part of the flap, which is harvested from the upper leg. The aim of this paper is to demonstrate that there is another important advantage of the modified flap: the use of the muscle cuff as a "plug" for small lower limb defects following debridement of infected/necrotic bone. A total of 10 male adult patients with small complex lower-limb defects with underlying bone pathology were treated with the modified flap using the muscle component to fill up the small bony defects. The bony pathology included necrotic exposed bone without evidence of osteomyelitis or wound infection (n = 1), an underlying neglected tibial fracture with wound infection (n = 4), and a sinus at the heel with underlying calcaneal osteomyelitis (n = 5). Primary wound healing of the flap into the defect was noted in all patients. No recurrence of calcaneal osteomyelitis was seen and all tibial fractures united following appropriate orthopedic fixation. It was concluded that the reverse sural artery fasciomusculocutaneous flap is well suited for small complex lower-limb defects with underlying bone pathology.

New nano-hydroxyapatite in bone defect regeneration: A histological study in rats.

Science.gov (United States)

Kubasiewicz-Ross, Paweł; Hadzik, Jakub; Seeliger, Julia; Kozak, Karol; Jurczyszyn, Kamil; Gerber, Hanna; Dominiak, Marzena; Kunert-Keil, Christiane

2017-09-01

Many types of bone substitute materials are available on the market. Researchers are refining new bone substitutes to make them comparable to autologous grafting materials in treatment of bone defects. The purpose of the study was to evaluate the osseoconductive potential and bone defect regeneration in rat calvaria bone defects treated with new synthetic nano-hydroxyapatite. The study was performed on 30 rats divided into 5 equal groups. New preproduction of experimental nano-hydroxyapatite material by NanoSynHap (Poznań, Poland) was tested and compared with commercially available materials. Five mm critical size defects were created and filled with the following bone grafting materials: 1) Geistlich Bio-Oss ® ; 2) nano-hydroxyapatite+β-TCP; 3) nano-hydroxyapatite; 4) nano-hydroxyapatite+collagen membrane. The last group served as controls without any augmentation. Bone samples from calvaria were harvested for histological and micro-ct evaluation after 8 weeks. New bone formation was observed in all groups. Histomorphometric analysis revealed an amount of regenerated bone between 34.2 and 44.4% in treated bone defects, whereas only 13.0% regenerated bone was found in controls. Interestingly, in group 3, no significant particles of the nano-HA material were found. In contrast, residual bone substitute material could be detected in all other test groups. Micro-CT study confirmed the results of the histological examinations. The new nano-hydroxyapatite provides comparable results to other grafts in the field of bone regeneration. Copyright © 2017 Elsevier GmbH. All rights reserved.

Birth Defects

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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 ...

Cement augmentation in the proximal femur to prevent stem subsidence in revision hip arthroplasty with Paprosky type II/IIIa defects

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Shang-Wen Tsai

2018-06-01

Full Text Available Background: Subsidence remains a common complication after revision hip arthroplasty which may lead to prolonged weight-bearing restrictions, leg-length discrepancies or considerable loss of function. We evaluated the effectiveness of cement augmentation in the proximal femoral metaphysis during a revision of femoral components to prevent post-operative stem subsidence. Methods: Forty patients were enrolled. Follow-up averaged 67.7 months (range: 24–149. Twenty-seven patients had a Paprosky type II defect and 13 had a type IIIa defect. All revision hip arthroplasty used a cementless, cylindrical, non-modular cobalt–chromium stem. The defect in the metaphysis was filled with antibiotic-loaded bone cement. Thirteen patients who had undergone stem revision only was allowed to walk immediately without weight-bearing restrictions. Twenty-seven patients who had undergone revision total hip arthroplasty was allowed partial weight-bearing within 6 weeks after surgery in the consideration of acetabular reconstruction. Results: Three patients (7.5% had post-surgery stem subsidences of three mm, five mm, and 10 mm, respectively, at three, one, and 14 months. There were no acute surgical site infections. There were three femoral stem failures: two delayed infections and one periprosthetic Vancouver B2 fracture. Both five- and 10-year survivorships of the femoral implant were 90.1%. Conclusion: An adequate length of the scratch-fit segment and diaphyseal ingrowth remain of paramount importance when revising femoral components. To fill metaphyseal bone defects with antibiotic-loaded bone cement may be an alternative method in dealing with proximal femoral bone loss during a femoral revision. Keywords: Bone defect, Cement augmentation, Femur, Revision hip arthroplasty, Subsidence

Bone Marrow Aspirate Concentrate-Enhanced Marrow Stimulation of Chondral Defects

Science.gov (United States)

Eichler, Hermann; Orth, Patrick

2017-01-01

Mesenchymal stem cells (MSCs) from bone marrow play a critical role in osteochondral repair. A bone marrow clot forms within the cartilage defect either as a result of marrow stimulation or during the course of the spontaneous repair of osteochondral defects. Mobilized pluripotent MSCs from the subchondral bone migrate into the defect filled with the clot, differentiate into chondrocytes and osteoblasts, and form a repair tissue over time. The additional application of a bone marrow aspirate (BMA) to the procedure of marrow stimulation is thought to enhance cartilage repair as it may provide both an additional cell population capable of chondrogenesis and a source of growth factors stimulating cartilage repair. Moreover, the BMA clot provides a three-dimensional environment, possibly further supporting chondrogenesis and protecting the subchondral bone from structural alterations. The purpose of this review is to bridge the gap in our understanding between the basic science knowledge on MSCs and BMA and the clinical and technical aspects of marrow stimulation-based cartilage repair by examining available data on the role and mechanisms of MSCs and BMA in osteochondral repair. Implications of findings from both translational and clinical studies using BMA concentrate-enhanced marrow stimulation are discussed. PMID:28607559

Platelet rich fibrin combined with decalcified freeze-dried bone allograft for the treatment of human intrabony periodontal defects: a randomized split mouth clinical trail.

Science.gov (United States)

Agarwal, Ashish; Gupta, Narinder Dev; Jain, Avikal

2016-01-01

Polypeptide growth factors of platelet rich fibrin (PRF) have the potential to regenerate periodontal tissues. Osteoinductive property of demineralized freeze-dried bone allograft (DFDBA) has been successfully utilized in periodontal regeneration. The aim of the present randomized, split mouth, clinical trial was to determine the additive effects of PRF with a DFDBA in the treatment of human intrabony periodontal defects. Sixty interproximal infrabony defects in 30 healthy, non-smoker patients diagnosed with chronic periodontitis were randomly assigned to PRF/DFDBA group or the DFDBA/saline. Clinical [pocket depth (PD), clinical attachment level (CAL) and gingival recession (REC)] and radiographic (bone fill, defect resolution and alveolar crest resorption) measurements were made at baseline and at a 12-month evaluation. Compared with baseline, 12-month results indicated that both treatment modalities resulted in significant changes in all clinical and radiographic parameters. However, the PRP/DFDBA group exhibited statistically significantly greater changes compared with the DFDBA/saline group in PD (4.15 ± 0.84 vs 3.60 ± 0.51 mm), CAL (3.73 ± 0.74 vs 2.61 ± 0.68 mm), REC (0.47 ± 0.56 vs 1.00 ± 0.61 mm), bone fill (3.50 ± 0.67 vs 2.49 ± 0.64 mm) and defect resolution (3.73 ± 0.63 vs 2.75 ± 0.57 mm). Observations indicate that a combination of PRF and DFDBA is more effective than DFDBA with saline for the treatment of infrabony periodontal defects.

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

Science.gov (United States)

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

2004-09-01

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

One-point functions in defect CFT and integrability

Energy Technology Data Exchange (ETDEWEB)

Leeuw, Marius de; Kristjansen, Charlotte [The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen Ø, DK-2100 (Denmark); Zarembo, Konstantin [NORDITA, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, Stockholm, SE-106 91 (Sweden); Department of Physics and Astronomy, Uppsala University, Uppsala, SE-751 08 (Sweden)

2015-08-19

We calculate planar tree level one-point functions of non-protected operators in the defect conformal field theory dual to the D3-D5 brane system with k units of the world volume flux. Working in the operator basis of Bethe eigenstates of the Heisenberg XXX{sub 1/2} spin chain we express the one-point functions as overlaps of these eigenstates with a matrix product state. For k=2 we obtain a closed expression of determinant form for any number of excitations, and in the case of half-filling we find a relation with the Néel state. In addition, we present a number of results for the limiting case k→∞.

Microhardness of bulk-fill composite materials

OpenAIRE

Kelić, Katarina; Matić, Sanja; Marović, Danijela; Klarić, Eva; Tarle, Zrinka

2016-01-01

The aim of the study was to determine microhardness of high- and low-viscosity bulk-fill composite resins and compare it with conventional composite materials. Four materials of high-viscosity were tested, including three bulk-fills: QuiXfi l (QF), x-tra fil (XTF) and Tetric EvoCeram Bulk Fill (TEBCF), while nanohybrid composite GrandioSO (GSO) served as control. The other four were low-viscosity composites, three bulk-fill materials: Smart Dentin Replacement (SDR), Venus Bulk Fill (VBF) and ...

Revealing origin of quasi-one dimensional current transport in defect rich two dimensional materials

International Nuclear Information System (INIS)

Lotz, Mikkel R.; Boll, Mads; Bøggild, Peter; Petersen, Dirch H.; Hansen, Ole; Kjær, Daniel

2014-01-01

The presence of defects in graphene have for a long time been recognized as a bottleneck for its utilization in electronic and mechanical devices. We recently showed that micro four-point probes may be used to evaluate if a graphene film is truly 2D or if defects in proximity of the probe will lead to a non-uniform current flow characteristic of lower dimensionality. In this work, simulations based on a finite element method together with a Monte Carlo approach are used to establish the transition from 2D to quasi-1D current transport, when applying a micro four-point probe to measure on 2D conductors with an increasing amount of line-shaped defects. Clear 2D and 1D signatures are observed at low and high defect densities, respectively, and current density plots reveal the presence of current channels or branches in defect configurations yielding 1D current transport. A strong correlation is found between the density filling factor and the simulation yield, the fraction of cases with 1D transport and the mean sheet conductance. The upper transition limit is shown to agree with the percolation threshold for sticks. Finally, the conductance of a square sample evaluated with macroscopic edge contacts is compared to the micro four-point probe conductance measurements and we find that the micro four-point probe tends to measure a slightly higher conductance in samples containing defects

Rapamycin inhibits BMP-7-induced osteogenic and lipogenic marker expressions in fetal rat calvarial cells.

Science.gov (United States)

Yeh, Lee-Chuan C; Ma, Xiuye; Ford, Jeffery J; Adamo, Martin L; Lee, John C

2013-08-01

Bone morphogenetic proteins (BMPs) promote osteoblast differentiation and bone formation in vitro and in vivo. BMPs canonically signal through Smad transcription factors, but BMPs may activate signaling pathways traditionally stimulated by growth factor tyrosine kinase receptors. Of these, the mTOR pathway has received considerable attention because BMPs activate P70S6K, a downstream effector of mTOR, suggesting that BMP-induced osteogenesis is mediated by mTOR activation. However, contradictory effects of the mTOR inhibitor rapamycin (RAPA) on bone formation have been reported. Since bone formation is thought to be inversely related to lipid accumulation and mTOR is also important for lipid synthesis, we postulated that BMP-7 may stimulate lipogenic enzyme expression in a RAPA-sensitive mechanism. To test this hypothesis, we determined the effects of RAPA on BMP-7-stimulated expression of osteogenic and lipogenic markers in cultured fetal rat calvarial cells. Our study showed that BMP-7 promoted the expression of osteogenic and lipogenic markers. The effect of BMP-7 on osteogenic markers was greater in magnitude than on lipogenic markers and was temporally more sustained. RAPA inhibited basal and BMP-7-stimulated osteogenic and lipogenic marker expression and bone nodule mineralization. The acetyl CoA carboxylase inhibitor TOFA stimulated the expression of osteoblast differentiation markers, whereas palmitate suppressed their expression. We speculate that the BMP-7-stimulated adipogenesis is part of the normal anabolic response to BMPs, but that inappropriate activation of the lipid biosynthetic pathway by mTOR could have deleterious effects on bone formation and could explain paradoxical effects of RAPA to promote bone formation. Copyright © 2013 Wiley Periodicals, Inc.

"Repair of cranial bone defects using endochondral bone matrix gelatin in rat "

Directory of Open Access Journals (Sweden)

"Sobhani A

2001-05-01

Full Text Available Bone matrix gelatin (BMG has been used for bone induction intramuscularly and subcutaneously by many investigators since 1965. More recently, some of the researchers have used BMG particles for bone repair and reported various results. In present study for evaluation of bone induction and new bone formation in parital defects, BMG particles were used in five groups of rats. The BMG was prepared as previously described using urist method. The defects wee produced with 5 –mm diameter in pariteal bones and filled by BMG particles. No BMG was used in control group.For evaluation of new bone formation and repair, the specimens were harvested on days 7 , 14 , 21 and 28 after operation. The samples were processed histologically, stained by H& E, alizarin red S staining, and Alcian blue, and studied by a light microscope.The results are as follows:In control group: Twenty-eight days after operation a narrow rim of new bone was detectable attached to the edge of defect.In BMG groups: At day 7 after operation young chondroblast cells appeared in whole area of defect. At 14th day after operation hypertrophic chondrocytes showed by Alcian blue staining and calcified cartilage were detectable by Alizarin red S staining. The numerous trabeculae spicules, early adult osteocytes and highly proliferated red bone marrow well developed on dayd 21 . finally typic bone trabeculae with regulated osteoblast cells and some osteoclast cells were detectable at day 28 after operation. In conclusion,BMG could stimulate bone induction and new bone formation in bony defects. So, it seems that BMG could be a godd biomaterial substance for new bone inducation in bone defects

Experiments of draining and filling processes in a collapsible tube at high external pressure

Science.gov (United States)

Flaud, P.; Guesdon, P.; Fullana, J.-M.

2012-02-01

The venous circulation in the lower limb is mainly controlled by the muscular action of the calf. To study the mechanisms governing the venous draining and filling process in such a situation, an experimental setup, composed by a collapsible tube under external pressure, has been built. A valve preventing back flows is inserted at the bottom of the tube and allows to model two different configurations: physiological when the fluid flow is uni-directional and pathological when the fluid flows in both directions. Pressure and flow rate measurements are carried out at the inlet and outlet of the tube and an original optical device with three cameras is proposed to measure the instantaneous cross-sectional area. The experimental results (draining and filling with physiological or pathological valves) are confronted to a simple one-dimensional numerical model which completes the physical interpretation. One major observation is that the muscular contraction induces a fast emptying phase followed by a slow one controlled by viscous effects, and that a defect of the valve decreases, as expected, the ejected volume.

Annealing Kinetic Model Using Fast and Slow Metastable Defects for Hydrogenated-Amorphous-Silicon-Based Solar Cells

Directory of Open Access Journals (Sweden)

Seung Yeop Myong

2007-01-01

Full Text Available The two-component kinetic model employing “fast” and “slow” metastable defects for the annealing behaviors in pin-type hydrogenated-amorphous-silicon- (a-Si:H- based solar cells is simulated using a normalized fill factor. Reported annealing data on pin-type a-Si:H-based solar cells are revisited and fitted using the model to confirm its validity. It is verified that the two-component model is suitable for fitting the various experimental phenomena. In addition, the activation energy for annealing of the solar cells depends on the definition of the recovery time. From the thermally activated and high electric field annealing behaviors, the plausible microscopic mechanism on the defect removal process is discussed.

Small atrial septal defect associated with heart failure in an infant with a marginal left ventricle

Directory of Open Access Journals (Sweden)

Sandra D.K. Kingma

2012-07-01

Full Text Available Atrial septal defect (ASD is usually asymptomatic in infancy, unless pulmonary hypertension or severe co-morbidity is present. We report a case of a 4-week-old infant with moderate- sized ASD, small patent ductus arteriosus (PDA, and a borderline sized left ventricle that developed heart failure. Despite the relatively small diameter of the ASD, this defect influenced the mechanism of heart failure significantly. After surgical closure of both PDA and ASD, the signs of pulmonary hypertension resolved and the patient developed a normal sized left ventricle. This report illustrates that the presence of a small ASD in combination with a marginal left ventricle may result in inadequate left ventricular filling, pulmonary hypertension and heart failure.

Effect of Irradiation on Apoptosis, Cell Cycle Arrest and Calcified Nodule Formation of Rat Calvarial Osteoblast

International Nuclear Information System (INIS)

Lee, Young Mi; Choi, Hang Moon; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won

2000-01-01

The study was aimed to detect the induction of apoptosis, cell cycle arrest and calcified nodule formation after irradiation on primarily cultured osteoblasts. Using rat calvarial osteoblasts, the effects of irradiation on apoptosis, cell cycle arrest, and calcified nodule formation were studied. The single irradiation of 10, 20 Gy was done with 5.38 Gy/min dose rate using the 137 Cs cell irradiator at 4th and 14th day of culture. Apoptosis induction and cell cycle arrest were assayed by the flow cytometry at 1, 2, 3, and 4 days after irradiation. The formation of calcified nodules was observed by alizarin red staining at 1, 3, 10, 14 days after irradiation at 4th day of culture, and at 1, 4, 5 days after irradiation at 14th day of culture. Apoptosis was not induced by 10 or 20 Gy independent of irradiation and culture period. Irradiation did not induced G1 arrest in post-irradiated osteoblasts. After irradiation at 4th-day of culture, G2 arrest was induced but it was not statistically significant after irradiation at 14th-day of culture. In the case of irradiated cells at 4th day of culture, calcified nodules were not formed and at 14th-day of culture after irradiation, calcified nodule formation did not affected. Taken together, these results suggest that irradiation at the dose of 10-20 Gy would not affect apoptosis induction of osteoblasts. Cell cycle and calcified nodule formation were influenced by the level of differentiation of osteblasts.

Radiopacity of root filling materials

International Nuclear Information System (INIS)

Beyer-Olsen, E.M.

1983-01-01

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

Influence of defects on the effective electrical conductivity of a monolayer produced by random sequential adsorption of linear k-mers onto a square lattice

Science.gov (United States)

Tarasevich, Yuri Yu.; Laptev, Valeri V.; Goltseva, Valeria A.; Lebovka, Nikolai I.

2017-07-01

The effect of defects on the behaviour of electrical conductivity, σ, in a monolayer produced by the random sequential adsorption of linear k-mers (particles occupying k adjacent sites) onto a square lattice is studied by means of a Monte Carlo simulation. The k-mers are deposited on the substrate until a jamming state is reached. The presence of defects in the lattice (impurities) and of defects in the k-mers with concentrations of dl and dk, respectively, is assumed. The defects in the lattice are distributed randomly before deposition and these lattice sites are forbidden for the deposition of k-mers. The defects of the k-mers are distributed randomly on the deposited k-mers. The sites filled with k-mers have high electrical conductivity, σk, whereas the empty sites, and the sites filled by either types of defect have a low electrical conductivity, σl, i.e., a high-contrast, σk /σl ≫ 1, is assumed. We examined isotropic (both the possible x and y orientations of a particle are equiprobable) and anisotropic (all particles are aligned along one given direction, y) deposition. To calculate the effective electrical conductivity, the monolayer was presented as a random resistor network and the Frank-Lobb algorithm was used. The effects of the concentrations of defects dl and dk on the electrical conductivity for the values of k =2n, where n = 1 , 2 , … , 5, were studied. Increase of both the dl and dk parameters values resulted in decreases in the value of σ and the suppression of percolation. Moreover, for anisotropic deposition the electrical conductivity along the y direction was noticeably larger than in the perpendicular direction, x. Phase diagrams in the (dl ,dk)-plane for different values of k were obtained.

Repair of articular cartilage defects by tissue-engineered cartilage constructed with adipose-derived stem cells and acellular cartilaginous matrix in rabbits.

Science.gov (United States)

Wang, Z J; An, R Z; Zhao, J Y; Zhang, Q; Yang, J; Wang, J B; Wen, G Y; Yuan, X H; Qi, X W; Li, S J; Ye, X C

2014-06-18

After injury, inflammation, or degeneration, articular cartilage has limited self-repair ability. We aimed to explore the feasibility of repair of articular cartilage defects with tissue-engineered cartilage constructed by acellular cartilage matrices (ACMs) seeded with adipose-derived stem cells (ADSCs). The ADSCs were isolated from 3-month-old New Zealand albino rabbit by using collagenase and cultured and amplified in vitro. Fresh cartilage isolated from adult New Zealand albino rabbit were freeze-dried for 12 h and treated with Triton X-100, DNase, and RNase to obtain ACMs. ADSCs were seeded in the acellular cartilaginous matrix at 2x10(7)/mL, and cultured in chondrogenic differentiation medium for 2 weeks to construct tissue-engineered cartilage. Twenty-four New Zealand white rabbits were randomly divided into A, B, and C groups. Engineered cartilage was transplanted into cartilage defect position of rabbits in group A, group B obtained ACMs, and group C did not receive any transplants. The rabbits were sacrificed in week 12. The restored tissue was evaluated using macroscopy, histology, immunohistochemistry, and transmission electron microscopy (TEM). In the tissue-engineered cartilage group (group A), articular cartilage defects of the rabbits were filled with chondrocyte-like tissue with smooth surface. Immunohistochemistry showed type II-collagen expression and Alcian blue staining was positive. TEM showed chondrocytes in the recesses, with plenty of secretary matrix particles. In the scaffold group (group B), the defect was filled with fibrous tissue. No repaired tissue was found in the blank group (group C). Tissue-engineered cartilage using ACM seeded with ADSCs can help repair articular cartilage defects in rabbits.

Effect of random inhomogeneities in the spatial distribution of radiation-induced defect clusters on carrier transport through the thin base of a heterojunction bipolar transistor upon neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Puzanov, A. S.; Obolenskiy, S. V., E-mail: obolensk@rf.unn.ru; Kozlov, V. A. [Lobachevsky State University of Nizhny Novgorod (NNSU) (Russian Federation)

2016-12-15

We analyze the electron transport through the thin base of a GaAs heterojunction bipolar transistor with regard to fluctuations in the spatial distribution of defect clusters induced by irradiation with a fissionspectrum fast neutron flux. We theoretically demonstrate that the homogeneous filling of the working region with radiation-induced defect clusters causes minimum degradation of the dc gain of the heterojunction bipolar transistor.

Estimation of water-filled and air-filled porosity in the unsaturated zone, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Nelson, P.H.

1993-01-01

Water content and porosity vary considerably within the unsaturated zone at Yucca Mountain. Measurement of these quantities has been based on core samples. A log-based approach offers the advantage of in-situ measurements, continuous throughout the borehole. This paper describes an algorithm which determines the air-filled and water-filled porosities from density and dielectric logs. The responses of density and dielectric logs are formulated in terms of the matrix properties, air-filled porosity and water-filled porosity. Porosity values obtained from logs from borehole USW G-2 are in reasonable agreement with estimates from core determinations

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

Directory of Open Access Journals (Sweden)

Olena Bulbuk

2017-06-01

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

The effect of tube filling on the electronic properties of Fe filled carbon nanotubes

International Nuclear Information System (INIS)

Linganiso, Ella C.; Chimowa, George; Franklyn, Paul J.; Bhattacharyya, Somnath; Coville, Neil J.

2012-01-01

Graphical abstract: HRTEM image of a twisted CNT filled with a bent single crystal of Fe. Insets from top to bottom show the power spectra of the corresponding regions, indicating the twisting of the Fe lattice. Inset in the top right shows the relative angling of the lattice fringes to accommodate the twisting of the Fe. Highlights: ► Synthesis of Fe filled CNTs with Fe content varying from 3 to 35%. ► TEM analysis indicates that Fe in the tubes is in contact with the CNTs. ► TEM analysis reveals that α-Fe crystallizes after CNT formation. ► Temperature dependent electronic transport measurements performed. ► Conductivity varies with the % Fe filling in the CNTs. - Abstract: Carbon nanotubes filled with Fe nanostructures (Fe-CNTs) were synthesized using an injection method in a 1-stage horizontal CVD furnace and a bubbling method in a 2-stage horizontal CVD reactor. Fe-CNTs were obtained through the pyrolysis of a mixture of dichlorobenzene and ferrocene in 5%H 2 /Ar. Metal impurities from the Fe-CNTs were removed using 1 M HCl solution. CNTs filled with crystalline Fe nanoparticles, nanorods and nanowires were obtained using these procedures. An intimate interaction between the Fe and the CNT was established by HRTEM studies. The α-Fe phase was observed to be the most dominant fraction found in the synthesized Fe-CNTs. The Fe 2 O 3 residue obtained from the TGA analysis revealed the amount of Fe filled inside the CNTs and this ranged between 3 and 31% by mass after purification. The temperature dependence of the conductivity in the temperature range between 2.5 and 100 K for an entangled network of Fe-CNTs was measured. An increase in conductivity due to the increased Fe filling inside the CNTs with increased temperature was observed. The observed temperature dependence was explained in terms of variable range hopping (VRH) conduction mechanisms. A transition from Efros–Shklovskii behavior at low % Fe filling of the CNTs to Mott 3D VRH behavior at

Systolic ventricular filling.

Science.gov (United States)

Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio; Komeda, Masashi; Cox, James; Flotats, A; Ballester-Rodes, Manel; Carreras-Costa, Francesc

2004-03-01

The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles

The effect of pre-vertebroplasty tumor ablation using laser-induced thermotherapy on biomechanical stability and cement fill in the metastatic spine.

Science.gov (United States)

Ahn, Henry; Mousavi, Payam; Chin, Lee; Roth, Sandra; Finkelstein, Joel; Vitken, Alex; Whyne, Cari

2007-08-01

A biomechanical study comparing simulated lytic vertebral metastases treated with laser-induced thermotherapy (LITT) and vertebroplasty versus vertebroplasty alone. To investigate the effect of tumor ablation using LITT prior to vertebroplasty on biomechanical stability and cement fill patterns in a standardized model of spinal metastatic disease. Vertebroplasty in the metastatic spine is aimed at reducing pain, but is associated with risk of cement extravasation in up to 10%. Six pairs of fresh-frozen cadaveric thoracolumbar spinal motion segments were tested in axial compression intact, with simulated metastases and following percutaneous vertebroplasty with or without LITT. Canal narrowing under load, pattern of cement fill, load to failure, and LITT temperature and pressure generation were collected. In all LITT specimens, cement filled the defect without extravasation. The canal extravasation rate was 33% in specimens treated without LITT. LITT and vertebroplasty yielded a trend toward improved posterior wall stability (P = 0.095) as compared to vertebroplasty alone. Moderate rises in temperature and minimal pressure generation was seen during LITT. In this model, elimination of tumor by LITT, facilitates cement fill, enhances biomechanical stability and reduces the risk of cement extravasation.

Segmentation, surface rendering, and surface simplification of 3-D skull images for the repair of a large skull defect

Science.gov (United States)

Wan, Weibing; Shi, Pengfei; Li, Shuguang

2009-10-01

Given the potential demonstrated by research into bone-tissue engineering, the use of medical image data for the rapid prototyping (RP) of scaffolds is a subject worthy of research. Computer-aided design and manufacture and medical imaging have created new possibilities for RP. Accurate and efficient design and fabrication of anatomic models is critical to these applications. We explore the application of RP computational methods to the repair of a pediatric skull defect. The focus of this study is the segmentation of the defect region seen in computerized tomography (CT) slice images of this patient's skull and the three-dimensional (3-D) surface rendering of the patient's CT-scan data. We see if our segmentation and surface rendering software can improve the generation of an implant model to fill a skull defect.

Bone regeneration by the osteoconductivity of porous titanium implants manufactured by selective laser melting: a histological and micro computed tomography study in the rabbit.

Science.gov (United States)

de Wild, Michael; Schumacher, Ralf; Mayer, Kyrill; Schkommodau, Erik; Thoma, Daniel; Bredell, Marius; Kruse Gujer, Astrid; Grätz, Klaus W; Weber, Franz E

2013-12-01

The treatment of large bone defects still poses a major challenge in orthopaedic and cranio-maxillofacial surgery. One possible solution could be the development of personalized porous titanium-based implants that are designed to meet all mechanical needs with a minimum amount of titanium and maximum osteopromotive properties so that it could be combined with growth factor-loaded hydrogels or cell constructs to realize advanced bone tissue engineering strategies. Such implants could prove useful for mandibular reconstruction, spinal fusion, the treatment of extended long bone defects, or to fill in gaps created on autograft harvesting. The aim of this study was to determine the mechanical properties and potential of bone formation of light weight implants generated by selective laser melting (SLM). We mainly focused on osteoconduction, as this is a key feature in bone healing and could serve as a back-up for osteoinduction and cell transplantation strategies. To that end, defined implants were produced by SLM, and their surfaces were left untreated, sandblasted, or sandblasted/acid etched. In vivo bone formation with the different implants was tested throughout calvarial defects in rabbits and compared with untreated defects. Analysis by micro computed tomography (μCT) and histomorphometry revealed that all generatively produced porous Ti structures were well osseointegrated into the surrounding bone. The histomorphometric analysis revealed that bone formation was significantly increased in all implant-treated groups compared with untreated defects and significantly increased in sand blasted implants compared with untreated ones. Bone bridging was significantly increased in sand blasted acid-etched scaffolds. Therefore, scaffolds manufactured by SLM should be surface treated. Bone augmentation beyond the original bone margins was only seen in implant-treated defects, indicating an osteoconductive potential of the implants that could be utilized clinically for bone

Vertical Scan-Conversion for Filling Purposes

OpenAIRE

Hersch, R. D.

1988-01-01

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

Dental enamel defects, caries experience and oral health-related quality of life: a cohort study.

Science.gov (United States)

Arrow, P

2017-06-01

The impact of enamel defects of the first permanent molars on caries experience and child oral health-related quality of life was evaluated in a cohort study. Children who participated in a study of enamel defects of the first permanent molars 8 years earlier were invited for a follow-up assessment. Consenting children completed the Child Perception Questionnaire and the faces Modified Child Dental Anxiety Scale, and were examined by two calibrated examiners. ANOVA, Kruskal-Wallis, negative binomial and logistic regression were used for data analyses. One hundred and eleven children returned a completed questionnaire and 91 were clinically examined. Negative binomial regression found that oral health impacts were associated with gender (boys, risk ratio (RR) = 0.73, P = 0.03) and decayed, missing or filled permanent teeth (DMFT) (RR = 1.1, P = 0.04). The mean DMFT of children were sound (0.9, standard deviation (SD) = 1.4), diffuse defects (0.8, SD = 1.7), demarcated defects (1.5, SD = 1.4) and pit defects (1.3, SD = 2.3) (Kruskal-Wallis, P = 0.05). Logistic regression of first permanent molar caries found higher odds of caries experience with baseline primary tooth caries experience (odds ratio (OR) = 1.5, P = 0.01), the number of teeth affected by enamel defects (OR = 1.9, P = 0.05) and lower odds with the presence of diffuse enamel defects (OR = 0.1, P = 0.04). The presence of diffuse enamel defects was associated with lower odds of caries experience. © 2016 Australian Dental Association.

Removal of root filling materials.

LENUS (Irish Health Repository)

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

2011-05-01

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

Evaluation of various boluses in dose distribution for electron therapy of the chest wall with an inward defect

Science.gov (United States)

Mahdavi, Hoda; Jabbari, Keyvan; Roayaei, Mahnaz

2016-01-01

Delivering radiotherapy to the postmastectomy chest wall can be achieved using matched electron fields. Surgical defects of the chest wall change the dose distribution of electrons. In this study, the improvement of dose homogeneity using simple, nonconformal techniques of thermoplastic bolus application on a defect is evaluated. The proposed phantom design improves the capability of film dosimetry for obtaining dose profiles of a patient's anatomical condition. A modeled electron field of a patient with a postmastectomy inward surgical defect was planned. High energy electrons were delivered to the phantom in various settings, including no bolus, a bolus that filled the inward defect (PB0), a uniform thickness bolus of 5 mm (PB1), and two 5 mm boluses (PB2). A reduction of mean doses at the base of the defect was observed by any bolus application. PB0 increased the dose at central parts of the defect, reduced hot areas at the base of steep edges, and reduced dose to the lung and heart. Thermoplastic boluses that compensate a defect (PB0) increased the homogeneity of dose in a fixed depth from the surface; adversely, PB2 increased the dose heterogeneity. This study shows that it is practical to investigate dose homogeneity profiles inside a target volume for various techniques of electron therapy. PMID:27051169

Immobile defects in ferroelastic walls: Wall nucleation at defect sites

Science.gov (United States)

He, X.; Salje, E. K. H.; Ding, X.; Sun, J.

2018-02-01

Randomly distributed, static defects are enriched in ferroelastic domain walls. The relative concentration of defects in walls, Nd, follows a power law distribution as a function of the total defect concentration C: N d ˜ C α with α = 0.4 . The enrichment Nd/C ranges from ˜50 times when C = 10 ppm to ˜3 times when C = 1000 ppm. The resulting enrichment is due to nucleation at defect sites as observed in large scale MD simulations. The dynamics of domain nucleation and switching is dependent on the defect concentration. Their energy distribution follows the power law with exponents during yield between ɛ ˜ 1.82 and 2.0 when the defect concentration increases. The power law exponent is ɛ ≈ 2.7 in the plastic regime, independent of the defect concentration.

Computed tomography to evaluate the association of fragmented heterolog cortical bone and methylmethacrylate to repare segmental bone defect produced in tibia of rabbits

International Nuclear Information System (INIS)

Freitas, S.H.; Doria, R.G.S.; Mendonca, F.S.; Santos, M.D.; Moreira, R.; Simoes, R.S.; Camargo, L.M.; Simoes, M.J.; Marques, A.T.C.

2012-01-01

A 6mm segmental defect was performed on the metaphyseal region of the tibia of 12 rabbits and the autoclaved fragmented heterolog cortical bone conserved in glycerin (98%) and methylmethacrylate was used as a bone graft for the reconstruction. The graft was placed in the receptor bed and its integration was evaluated by computed tomography after 30, 60 and 90 days. There was gradual bone graft incorporation in the receptor bed during the time in 100% of the cases. Fragmented cortical bone heterograft and methylmethacrylate was biologically compatible and promotes bone defect reparation without signs of infection, migration and or rejection, featuring a new option of osseous substitute to fill in bone defects. (author)

Improved detection of fill-in using sublingual nitroglycerin in technetium-99m tetrofosmin exercise/rest single photon emission computed tomography one day protocol for old myocardial infarction

International Nuclear Information System (INIS)

Miyanaga, Hajime; Kunieda, Yasufumi; Oguni, Atsuhiko; Kamitani, Tadaaki; Kawasaki, Shingo; Takahashi, Toru

1999-01-01

Twenty-one patients with old myocardial infarction underwent repeated 99m Tc-tetrofosmin ( 99m Tc) exercise/rest same day protocols with and without the administration of sublingual nitroglycerin (NTG) 5 min before the second injection of 99m Tc for rest SPECT. Twelve of these patients also underwent ordinary exercise/redistribution 201 Tl SPECT. The control study protocol images showed decreased uptake of 99m Tc on exercise in 157 of 420 segments and the presence of fill-in at rest in 58 segments. Images obtained with administration of NTG showed decreased uptake of 99m Tc on exercise in 163 of 420 segments and fill-in in 74 segments at rest. The frequency of fill-in was greater in the NTG protocol than in the control protocol. The segments were scored as different grades according to 99m Tc uptake between 2 protocols. Fill-in was only present or more remarkable in 31 segments in the NTG protocol than in the control protocol. Fill-in was only present or more remarkable in 10 segments in the control protocol than in the NTG protocol. In the NTG protocol, the mean defect score of the exercise images, calculated from the bull's eye image automatically, was higher than that of the rest images. The mean severity score of the exercise images, also calculated from the bull's eye image automatically, was likewise higher than that of the rest images, whereas the mean severity score of the stress images and rest images in the control protocol was not significantly different. Moreover, the mean defect score and severity score of the rest images from the NTG protocol were significantly lower than those obtained from the control protocol. Sublingual NTG administration before the injection of 99m Tc-tetrofosmin at the rest study in the one day exercise/rest studies enhanced fill-in, so may enhance the detection of viable myocardium, allowing more informed decisions regarding cardiac revascularization in patients with chronic coronary artery disease. (K.H.)

Technology of hardening fills for mined spaces

International Nuclear Information System (INIS)

Simek, P.; Holas, M.; Chyla, A.; Pech, P.

1985-01-01

The technology is described of hardening fills for mined spaces of uranium deposits in North Bohemian chalk. A special equipment was developed for the controlled preparation of a hardening mixture. The composition of the fill is determined by the strength of the filled rock, expecially by the standard strength, i.e., the minimal strength of the filling under uniaxial pressure. The said parameter determines the consumption of binding materials and thereby the total costs of the filling. A description is presented of the filling technology, including rabbit tube transport of the mixture and quality control. (Pu)

Gas-filled hohlraum fabrication

International Nuclear Information System (INIS)

Salazar, M.A.; Gobby, P.L.; Foreman, L.R.; Bush, H. Jr.; Gomez, V.M.; Moore, J.E.; Stone, G.F.

1995-01-01

Los Alamos National Laboratory (LANL) researchers have fabricated and fielded gas-filled hohlraums at the Lawrence Livermore National Laboratory (LLNL) Nova laser. Fill pressures of 1--5 atmospheres have been typical. We describe the production of the parts, their assembly and fielding. Emphasis is placed on the production of gas-tight polyimide windows and the fielding apparatus and procedure

Clinical and radiographic evaluation of citric acid-based nano hydroxyapatite composite graft in the regeneration of intrabony defects - A randomized controlled trial

Directory of Open Access Journals (Sweden)

Chaurasia Priya Dayashankar

2017-01-01

Full Text Available Background: Conventional periodontal therapy with various bone grafts has limited scope and the results are not predictable. To improve their utility, the hybridization of bioceramics and biodegradable polymers has been widely adopted to reform the mechanical properties of bone grafts. One such biodegradable polymer is POC (Poly 1,8 octanediol. Secondly, citric acid is considered as the key material in bone mineralization, which is related to the overall stability, strength and fracture resistance of bone. Hence citric acid is incorporated in a polymer and Nano hydroxyapatite to form a composite graft, for periodontal bone regeneration. This study attempts to evaluate the efficacy of citric acid based Nano-hydroxyapatite composite graft for the treatment of intrabony defects in chronic periodontitis patients over 12 months. Methods: A split mouth study, which consists of 10 systemically healthy patients, were randomly treated with Citric acid based Nano hydroxyapatite composite graft (test sites, n=18 or with Nano hydroxyapatite alone (control sites, n=15. Plaque index, gingival index, gingival bleeding index, probing pocket depth (PPD, clinical attachment level (CAL, 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 over a period of 12 months. Statistical analysis used was student's t-test and One-Way ANOVA. Results: Both test and control sites demonstrated statistically significant reduction of PD, BPD, gain in CAL and radiographic bone fill. Nevertheless the test sites showed Statistically significant improvements in all the parameters as compared to control sites at 12 months. Conclusion: Citric acid based Nano hydroxyapatite composite graft can be considered as a newer material for periodontal regeneration.

NSLS-II filling pattern measurement

International Nuclear Information System (INIS)

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

2012-01-01

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

Effect of platelet-rich plasma combined with demineralised bone matrix on bone healing in rabbit ulnar defects.

Science.gov (United States)

Galanis, Vasilios; Fiska, Alice; Kapetanakis, Stylianos; Kazakos, Konstantinos; Demetriou, Thespis

2017-09-01

This study evaluates the effect of autologous platelet-rich plasma (PRP) combined with xenogeneic demineralised bone matrix (DBM) on bone healing of critical-size ulnar defects (2-2.5 times the ulnar diameter) in New Zealand White rabbits. Critical-size defects were created unilaterally in the ulna of 36 rabbits, while keeping the contralateral limb intact. They were divided into three groups. In Group A, the defect was filled with autologous PRP and in Group B, with autologous PRP combined with DBM; in Group C, the defect remained empty. The rabbits were euthanised 12 weeks postoperatively. Radiological, biomechanical and histological assessments were carried out and statistical analysis of the results was performed. Group B had significantly higher radiological and histological scores than Groups A and C. Defects in Group B showed significant new bone formation, whereas there was minimal or no new bone formation in Groups A and C. Only specimens in Group B showed macroscopic bone union. Biomechanical evaluation of the treated and intact contralateral limbs in Group B showed significant differences. In this study, statistically significant enhancement of bone healing was found in critical-size defects treated with PRP and DBM, as shown by radiological findings, gross assessment, and biomechanical and histopathological results. Defects in the two other groups remained unbridged. Therefore, PRP was effective only when it was used in combination with a bone graft. Copyright: © Singapore Medical Association

Cartilage Regeneration in Full-Thickness Patellar Chondral Defects Treated with Particulated Juvenile Articular Allograft Cartilage: An MRI Analysis.

Science.gov (United States)

Grawe, Brian; Burge, Alissa; Nguyen, Joseph; Strickland, Sabrina; Warren, Russell; Rodeo, Scott; Shubin Stein, Beth

2017-10-01

Background Full-thickness cartilage lesions of the patella represent a common source of pain and dysfunction. Previously reported surgical treatment options include marrow stimulation, cell-based treatments, and osteochondral transfer. Minced juvenile allograft cartilage is a novel treatment option that allows for a single stage approach for these lesions. Hypothesis Particulated juvenile allograft cartilage (PJAC) for the treatment of chondral defects of the patella would offer acceptable lesion fill rates, mature over time, and not be associated with any negative biologic effects on the surrounding tissue. Methods A retrospective chart review of prospectively collected data was conducted to identify consecutive patients who were treated with PJAC for a full thickness symptomatic cartilage lesion. Qualitative (fast spin echo) and quantitative (T2 mapping) magnetic resonance imaging (MRI) was undertaken at the 6-, 12-, and 24-month postoperative mark. Numerous patient, lesion, and graft specific factors were assessed against MRI scores and percent defect fill of the graft. Graft maturation over time was also assessed. Results Forty-five patients total were included in the study. Average age at the time of surgery was 26.5 years (range 13-45 years), average lesion size was 208 mm 2 (range 4-500 mm 2 ), and average donor age was 49.5 months (range 3-120 months). Sixty percent of the patients were female, while 93% of all patients underwent a concomitant procedure at the time of the index operation. Six-month MRI findings revealed that no patient-, graft-, or donor-specific factors correlated with MR scores, and 82% of the knees demonstrated good to excellent fill. Twelve-month MRI findings revealed that T2 relaxation times of deep graft demonstrated negative correlation with patient age ( P = 0.049) and donor age ( P = 0.006), the integration zone showed a negative correlation with donor age ( P = 0.026). In all, 85% of patients at 12 months displayed good to

Review of fill mining technology in Canada

Energy Technology Data Exchange (ETDEWEB)

Singh, K. H.; Hedley, D. G.F.

1980-05-15

The Canadian mining industry has a long history of being in the fore-front in developing new technology in underground hardrock mines. Examples include the development of hydraulic and cemented fills, undercut-and-fill, mechanized cut-and-fill, post pillar, vertical retreat and blasthole mining methods. The evolution of this technology is briefly described in an historical review. Backfill serves many functions, although it is generally considered in terms of its support capabilities. These functions, mainly related to the mining method used, are evaluated in regard to regional support, pillar support, fill roof, working floor, dilution control and waste disposal. With the advent of blasthole and vertical retreat methods for pillar recovery operations, the freestanding height of backfill walls has assumed greater importance. Consequently, more attention is being given to what fill properties are required to achieve fill wall exposures up to 25 m wide by 90 m high. With the large increases in energy costs, alternatives to partially replace Portland cement in fill are being examined. The validation of mining concepts and the interaction of backfill is perhaps best evaluated by in-situ measurements. Examples are given of stress, deformation and fill pressure measurements in longitudinal cut-and-fill, post pillar mining and blasthole stoping with delayed fill which were taken in several mines in Canada. Finally, the overall design procedure used in deciding mining method, stope and pillar dimensions, sequence of extraction, fill properties and support systems at a new mine is described.

Text-Filled Stacked Area Graphs

DEFF Research Database (Denmark)

Kraus, Martin

2011-01-01

-filled stacked area graphs; i.e., graphs that feature stacked areas that are filled with small-typed text. Since these graphs allow for computing the text layout automatically, it is possible to include large amounts of textual detail with very little effort. We discuss the most important challenges and some...... solutions for the design of text-filled stacked area graphs with the help of an exemplary visualization of the genres, publication years, and titles of a database of several thousand PC games....

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

Directory of Open Access Journals (Sweden)

Marcelo Diniz Carvalho

2011-02-01

Full Text Available 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. CONCLUSIONS: Within the limits of this study, it may be concluded that PRP failed to provide statistically significant improvements in the histometric parameters.

Studies of defects and defect agglomerates by positron annihilation spectroscopy

DEFF Research Database (Denmark)

Eldrup, Morten Mostgaard; Singh, B.N.

1997-01-01

A brief introduction to positron annihilation spectroscopy (PAS), and in particular lo its use for defect studies in metals is given. Positrons injected into a metal may become trapped in defects such as vacancies, vacancy clusters, voids, bubbles and dislocations and subsequently annihilate from...... the trapped state iri the defect. The annihilation characteristics (e.g., the lifetime of the positron) can be measured and provide information about the nature of the defect (e.g., size, density, morphology). The technique is sensitive to both defect size (in the range from monovacancies up to cavities...

Midfacial analysis and planning for midface augmentation with injectable filling materials: an anatomical approach.

Science.gov (United States)

Taheri, A; Mansoori, P

2012-06-01

  Midfacial augmentation improves the appearance of patients with flat or ptotic cheek.   To develop a simple method of preoperative delineating the location of the ideal malar prominence and determining the best area to augment with injectable filling materials.   We used detailed analysis of the facial features of some Caucasian men and women as the basis for this study.   We described a technique to locate the ideal malar prominence and proposed a classification of midfacial contour defects.   This method greatly simplifies the surgeon's task of determining the area to be augmented. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

Defect modelling

International Nuclear Information System (INIS)

Norgett, M.J.

1980-01-01

Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK)

7 CFR 58.923 - Filling containers.

Science.gov (United States)

2010-01-01

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

An Evaluation of GuttaFlow2 in Filling Artificial Internal Resorption Cavities: An in vitro Study.

Science.gov (United States)

Mohammad, Yara; Alafif, Hisham; Hajeer, Mohammad; Yassin, Oula

2016-06-01

walls, ease of handling, and application. Internal resorption defects can be successfully filled with GuttaFlow2 material when supplemented with a master cone, and the results are comparable with those obtained with the Obtura II technique.

Aging Mechanisms and Nondestructive Aging Indicator of Filled Cross-linked Polyethylene (XLPE) Exposed to Simultaneous Thermal and Gamma Radiation

Energy Technology Data Exchange (ETDEWEB)

Liu, Shuaishuai; Fifield, Leonard S.; Bowler, Nicola

2018-04-11

Aging mechanisms and a nondestructive aging indicator of filled cross-linked polyethylene (XLPE) cable insulation material used in nuclear power plants (NPPs) are studied. Using various material characterization techniques, likely candidates and functions for the main additives in a commercial filled-XLPE insulation material have been identified. These include decabromodiphenyl ether and Sb2O3 as flame retardants, ZnS as white pigment and polymerized 1,2-dihydro-2,2,4-trimethylquinoline as antioxidant. Gas chromatography-mass spectrometry, differential scanning calorimetry, oxidation induction time and measurements of dielectric loss tangent are utilized to monitor property changes as a function of thermal and radiation exposure of the cable material. Small-molecular-weight hydrocarbons are evolve with gamma radiation aging at 90 °C. The level of antioxidant decreases with aging by volatilization and chemical reaction with free radicals. Thermal aging at 90 °C for 25 days or less causes no observable change to the cross-linked polymer structure. Gamma radiation causes damage to crystalline polymer regions and introduces defects. Dielectric loss tangent is shown to be an effective and reliable nondestructive indicator of the aging severity of the filled-XLPE insulation material.

Diffuse scattering and defect structure simulations a cook book using the program DISCUS

CERN Document Server

Neder, Reinhard B

2009-01-01

In recent years it has become apparent that knowing the average atomic structure of materials is insufficient to understand their properties. Diffuse scattering in addition to the Bragg scattering holds the key to learning about defects in materials, the topic of many recent books. What has been missing is a detailed step-by-step guide how to simulate disordered materials. The DISCUS cook book fills this need covering simple topics such as building a computer crystal to complextopic such as domain structures, stacking faults or using advanced refinement techniques to adjust parameters on a dis

Effects of calcium phosphate/chitosan composite on bone healing in rats: calcium phosphate induces osteon formation.

Science.gov (United States)

Fernández, Tulio; Olave, Gilberto; Valencia, Carlos H; Arce, Sandra; Quinn, Julian M W; Thouas, George A; Chen, Qi-Zhi

2014-07-01

Vascularization of an artificial graft represents one of the most significant challenges facing the field of bone tissue engineering. Over the past decade, strategies to vascularize artificial scaffolds have been intensively evaluated using osteoinductive calcium phosphate (CaP) biomaterials in animal models. In this work, we observed that CaP-based biomaterials implanted into rat calvarial defects showed remarkably accelerated formation and mineralization of new woven bone in defects in the initial stages, at a rate of ∼60 μm/day (0.8 mg/day), which was considerably higher than normal bone growth rates (several μm/day, 0.1 mg/day) in implant-free controls of the same age. Surprisingly, we also observed histological evidence of primary osteon formation, indicated by blood vessels in early-region fibrous tissue, which was encapsulated by lamellar osteocyte structures. These were later fully replaced by compact bone, indicating complete regeneration of calvarial bone. Thus, the CaP biomaterial used here is not only osteoinductive, but vasculogenic, and it may have contributed to the bone regeneration, despite an absence of osteons in normal rat calvaria. Further investigation will involve how this strategy can regulate formation of vascularized cortical bone such as by control of degradation rate, and use of models of long, dense bones, to more closely approximate repair of human cortical bone.

Immobilization of Murine Anti-BMP-2 Monoclonal Antibody on Various Biomaterials for Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Sahar Ansari

2014-01-01

Full Text Available Biomaterials are widely used as scaffolds for tissue engineering. We have developed a strategy for bone tissue engineering that entails application of immobilized anti-BMP-2 monoclonal antibodies (mAbs to capture endogenous BMPs in vivo and promote antibody-mediated osseous regeneration (AMOR. The purpose of the current study was to compare the efficacy of immobilization of a specific murine anti-BMP-2 mAb on three different types of biomaterials and to evaluate their suitability as scaffolds for AMOR. Anti-BMP-2 mAb or isotype control mAb was immobilized on titanium (Ti microbeads, alginate hydrogel, and ACS. The treated biomaterials were surgically implanted in rat critical-sized calvarial defects. After 8 weeks, de novo bone formation was assessed using micro-CT and histomorphometric analyses. Results showed de novo bone regeneration with all three scaffolds with immobilized anti-BMP-2 mAb, but not isotype control mAb. Ti microbeads showed the highest volume of bone regeneration, followed by ACS. Alginate showed the lowest volume of bone. Localization of BMP-2, -4, and -7 antigens was detected on all 3 scaffolds with immobilized anti-BMP-2 mAb implanted in calvarial defects. Altogether, these data suggested a potential mechanism for bone regeneration through entrapment of endogenous BMP-2, -4, and -7 proteins leading to bone formation using different types of scaffolds via AMOR.

TWO-STAGE REVISION HIP REPLACEMENT PATIENS WITH SEVERE ACETABULUM DEFECT (CASE REPORT

Directory of Open Access Journals (Sweden)

V. V. Pavlov

2017-01-01

Full Text Available Favorable short-term results of arthroplasty are observed in 80–90% of cases, however, over the longer follow up period the percentage of positive outcomes is gradually reduced. Need for revision of the prosthesis or it’s components increases in proportion to time elapsed from the surgery. In addition, such revision is accompanied with a need to substitute the bone defect of the acetabulum. As a solution the authors propose to replace pelvic defects in two stages. During the first stage the defect was filled with bone allograft with platelet-rich fibrin (allografting with the use of PRF technology. After the allograft remodeling during the second stage the revision surgery is performed by implanting standard prostheses. The authors present a clinical case of a female patient with aseptic loosening of acetabular component of prosthesis in the right hip joint, with failed hip function of stage 2, right limb shortening of 2 cm. Treatment results confirm the efficiency and rationality of the proposed bone grafting option. The authors conclude bone allograft in combination with the PRF technology proves to be an alternative to the implantation of massive metal implants in the acetabulum while it reduces the risk of implant-associated infection, of metallosis in surrounding tissues and expands further revision options.

Raman spectroscopic study of the repair of surgical bone defects grafted or not with biphasic synthetic micro-granular HA + β-calcium triphosphate irradiated or not with λ850 nm LED light.

Science.gov (United States)

Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Guarda, Milena G; Aciole, Jouber Mateus S; Andrade, Aline S; Pinheiro, Antonio Luiz B; Silveira, Landulfo

2014-11-01

The handling of bone losses due to different etiologic factors is difficult and many techniques are aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (~960, ~1,070, and 1,077 cm(-1)) and organic (~1,454 and ~1,666 cm(-1)) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of sacrifice (15 and 30 days). Surgical bone defects were made on the femur of each animal with a trephine drill. On animals of group clot, the defect was filled only by blood clot, on group LED, the defect filled with the clot was further irradiated. On animals of groups biomaterial and LED + biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ850 ± 10 nm, 150 mW, Φ ~ 0.5 cm(2), 20 J/cm(2)-session, 140 J/cm(2)-treatment) at 48-h intervals and repeated for 2 weeks. At both 15th and 30th days following sacrifice, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensity of hydroxyapatite (HA) (~960 cm(-1)) were higher on group LED + biomaterial and the peaks of both organic content (~1,454 and ~1,666 cm(-1)) and transitional HA (~1,070 and ~1,077 cm(-1)) were lower on the same group. It is concluded that the use of LED phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of HA measured by Raman spectroscopy.

Repair of full-thickness articular cartilage defects by cultured mesenchymal stem cells transfected with the transforming growth factor β1 gene

International Nuclear Information System (INIS)

Guo Xiaodong; Zheng Qixin; Yang Shuhua; Shao Zengwu; Yuan Quan; Pan Zhengqi; Tang Shuo; Liu Kai; Quan Daping

2006-01-01

Articular cartilage repair remains a clinical and scientific challenge with increasing interest focused on the combined techniques of gene transfer and tissue engineering. Transforming growth factor beta 1 (TGF-β 1 ) is a multifunctional molecule that plays a central role in promotion of cartilage repair, and inhibition of inflammatory and alloreactive immune response. Cell mediated gene therapy can allow a sustained expression of TGF-β 1 that may circumvent difficulties associated with growth factor delivery. The objective of this study was to investigate whether TGF-β 1 gene modified mesenchymal stem cells (MSCs) could enhance the repair of full-thickness articular cartilage defects in allogeneic rabbits. The pcDNA 3 -TGF-β 1 gene transfected MSCs were seeded onto biodegradable poly-L-lysine coated polylactide (PLA) biomimetic scaffolds in vitro and allografted into full-thickness articular cartilage defects in 18 New Zealand rabbits. The pcDNA 3 gene transfected MSCs/biomimetic scaffold composites and the cell-free scaffolds were taken as control groups I and II, respectively. The follow-up times were 2, 4, 12 and 24 weeks. Macroscopical, histological and ultrastructural studies were performed. In vitro SEM studies found that abundant cartilaginous matrices were generated and completely covered the interconnected pores of the scaffolds two weeks post-seeding in the experimental groups. In vivo, the quality of regenerated tissue improved over time with hyaline cartilage filling the chondral region and a mixture of trabecular and compact bone filling the subchondral region at 24 weeks post-implantation. Joint repair in the experimental groups was better than that of either control group I or II, with respect to: (1) synthesis of hyaline cartilage specific extracellular matrix at the upper portion of the defect; (2) reconstitution of the subchondral bone at the lower portion of the defect and (3) inhibition of inflammatory and alloreactive immune responses. The

Raman spectra of filled carbon nanotubes

International Nuclear Information System (INIS)

Bose, S.M.; Behera, S.N.; Sarangi, S.N.; Entel, P.

2004-01-01

The Raman spectra of a metallic carbon nanotube filled with atoms or molecules have been investigated theoretically. It is found that there will be a three way splitting of the main Raman lines due to the interaction of the nanotube phonon with the collective excitations (plasmons) of the conduction electrons of the nanotube as well as its coupling with the phonon of the filling material. The positions and relative strengths of these Raman peaks depend on the strength of the electron-phonon interaction, phonon frequency of the filling atom and the strength of interaction of the nanotube phonon and the phonon of the filling atoms. Careful experimental studies of the Raman spectra of filled nanotubes should show these three peaks. It is also shown that in a semiconducting nanotube the Raman line will split into two and should be observed experimentally

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

Directory of Open Access Journals (Sweden)

Vahid Esfahanian

2014-12-01

Full Text Available 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 effec-tiveness 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 pa-tients 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 gingi-val 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 reduc-tion: 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.

Dual delivery of rhPDGF-BB and bone marrow mesenchymal stromal cells expressing the BMP2 gene enhance bone formation in a critical-sized defect model.

Science.gov (United States)

Park, Shin-Young; Kim, Kyoung-Hwa; Shin, Seung-Yun; Koo, Ki-Tae; Lee, Yong-Moo; Seol, Yang-Jo

2013-11-01

Bone tissue healing is a dynamic, orchestrated process that relies on multiple growth factors and cell types. Platelet-derived growth factor-BB (PDGF-BB) is released from platelets at wound sites and induces cellular migration and proliferation necessary for bone regeneration in the early healing process. Bone morphogenetic protein-2 (BMP-2), the most potent osteogenic differentiation inducer, directs new bone formation at the sites of bone defects. This study evaluated a combinatorial treatment protocol of PDGF-BB and BMP-2 on bone healing in a critical-sized defect model. To mimic the bone tissue healing process, a dual delivery approach was designed to deliver the rhPDGF-BB protein transiently during the early healing phase, whereas BMP-2 was supplied by rat bone marrow stromal cells (BMSCs) transfected with an adenoviral vector containing the BMP2 gene (AdBMP2) for prolonged release throughout the healing process. In in vitro experiments, the dual delivery of rhPDGF-BB and BMP2 significantly enhanced cell proliferation. However, the osteogenic differentiation of BMSCs was significantly suppressed even though the amount of BMP-2 secreted by the AdBMP2-transfected BMSCs was not significantly affected by the rhPDGF-BB treatment. In addition, dual delivery inhibited the mRNA expression of BMP receptor type II and Noggin in BMSCs. In in vivo experiments, critical-sized calvarial defects in rats showed enhanced bone regeneration by dual delivery of autologous AdBMP2-transfected BMSCs and rhPDGF-BB in both the amount of new bone formed and the bone mineral density. These enhancements in bone regeneration were greater than those observed in the group treated with AdBMP2-transfected BMSCs alone. In conclusion, the dual delivery of rhPDGF-BB and AdBMP2-transfected BMSCs improved the quality of the regenerated bone, possibly due to the modulation of PDGF-BB on BMP-2-induced osteogenesis.

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

Energy Technology Data Exchange (ETDEWEB)

Heinisch, H.L. [Pacific Northwest National Lab., Richland, WA (United States)

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.

Dirichlet topological defects

International Nuclear Information System (INIS)

Carroll, S.M.; Trodden, M.

1998-01-01

We propose a class of field theories featuring solitonic solutions in which topological defects can end when they intersect other defects of equal or higher dimensionality. Such configurations may be termed open-quotes Dirichlet topological defects,close quotes in analogy with the D-branes of string theory. Our discussion focuses on defects in scalar field theories with either gauge or global symmetries, in 3+1 dimensions; the types of defects considered include walls ending on walls, strings on walls, and strings on strings. copyright 1998 The American Physical Society

Silicon exfoliation by hydrogen implantation: Actual nature of precursor defects

Energy Technology Data Exchange (ETDEWEB)

Kuisseu, Pauline Sylvia Pokam, E-mail: pauline-sylvia.pokam-kuisseu@cnrs-orleans.fr [CEMHTI-CNRS, 3A, rue de la férollerie, 45071 Orléans (France); Pingault, Timothée; Ntsoenzok, Esidor [CEMHTI-CNRS, 3A, rue de la férollerie, 45071 Orléans (France); Regula, Gabrielle [IM2NP-CNRS-Université d’Aix-Marseille, Avenue Escadrille Normandie Niemen, 13397 Marseille (France); Mazen, Frédéric [CEA-Leti, MINATEC campus, 17, rue des Martyrs, 38054 Grenoble Cedex 9 (France); Sauldubois, Audrey [Université d’Orléans, rue de Chartres – Collegium ST, 45067 Orléans (France); Andreazza, Caroline [ICMN-CNRS-Université d’Orléans, 1b rue de la férollerie, 45071 Orléans (France)

2017-06-15

MeV energy hydrogen implantation in silicon followed by a thermal annealing is a very smart way to produce high crystalline quality silicon substrates, much thinner than what can be obtained by diamond disk or wire sawing. Using this kerf-less approach, ultra-thin substrates with thicknesses between 15 µm and 100 µm, compatible with microelectronic and photovoltaic applications are reported. But, despite the benefits of this approach, there is still a lack of fundamental studies at this implantation energy range. However, if very few papers have addressed the MeV energy range, a lot of works have been carried out in the keV implantation energy range, which is the one used in the smart-cut® technology. In order to check if the nature and the growth mechanism of extended defects reported in the widely studied keV implantation energy range could be extrapolated in the MeV range, the thermal evolution of extended defects formed after MeV hydrogen implantation in (100) Si was investigated in this study. Samples were implanted at 1 MeV with different fluences ranging from 6 × 10{sup 16} H/cm{sup 2} to 2 × 10{sup 17} H/cm{sup 2} and annealed at temperatures up to 873 K. By cross-section transmission electron microscopy, we found that the nature of extended defects in the MeV range is quite different of what is observed in the keV range. In fact, in our implantation conditions, the generated extended defects are some kinds of planar clusters of gas-filled lenses, instead of platelets as commonly reported in the keV energy range. This result underlines that hydrogen behaves differently when it is introduced in silicon at high or low implantation energy. The activation energy of the growth of these extended defects is independent of the chosen fluence and is between (0.5–0.6) eV, which is very close to the activation energy reported for atomic hydrogen diffusion in a perfect silicon crystal.

Repair of full-thickness articular cartilage defects by cultured mesenchymal stem cells transfected with the transforming growth factor {beta}{sub 1} gene

Energy Technology Data Exchange (ETDEWEB)

Guo Xiaodong [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng Qixin [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yang Shuhua [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Shao Zengwu [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yuan Quan [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Pan Zhengqi [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Tang Shuo [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Liu Kai [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Quan Daping [Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

2006-12-15

Articular cartilage repair remains a clinical and scientific challenge with increasing interest focused on the combined techniques of gene transfer and tissue engineering. Transforming growth factor beta 1 (TGF-{beta}{sub 1}) is a multifunctional molecule that plays a central role in promotion of cartilage repair, and inhibition of inflammatory and alloreactive immune response. Cell mediated gene therapy can allow a sustained expression of TGF-{beta}{sub 1} that may circumvent difficulties associated with growth factor delivery. The objective of this study was to investigate whether TGF-{beta}{sub 1} gene modified mesenchymal stem cells (MSCs) could enhance the repair of full-thickness articular cartilage defects in allogeneic rabbits. The pcDNA{sub 3}-TGF-{beta}{sub 1} gene transfected MSCs were seeded onto biodegradable poly-L-lysine coated polylactide (PLA) biomimetic scaffolds in vitro and allografted into full-thickness articular cartilage defects in 18 New Zealand rabbits. The pcDNA{sub 3} gene transfected MSCs/biomimetic scaffold composites and the cell-free scaffolds were taken as control groups I and II, respectively. The follow-up times were 2, 4, 12 and 24 weeks. Macroscopical, histological and ultrastructural studies were performed. In vitro SEM studies found that abundant cartilaginous matrices were generated and completely covered the interconnected pores of the scaffolds two weeks post-seeding in the experimental groups. In vivo, the quality of regenerated tissue improved over time with hyaline cartilage filling the chondral region and a mixture of trabecular and compact bone filling the subchondral region at 24 weeks post-implantation. Joint repair in the experimental groups was better than that of either control group I or II, with respect to: (1) synthesis of hyaline cartilage specific extracellular matrix at the upper portion of the defect; (2) reconstitution of the subchondral bone at the lower portion of the defect and (3) inhibition of

Brown colour in natural diamond and interaction between the brown related and other colour-inducing defects

International Nuclear Information System (INIS)

Fisher, D; Sibley, S J; Kelly, C J

2009-01-01

Absorption spectroscopy results on a range of type II diamonds are presented which enable the electronic states associated with them to be mapped out. High pressure, high temperature treatment of brown type IIa diamonds has enabled an activation energy for the removal of the brown colour of 8.0 ± 0.3 eV to be determined and this is consistent with expectations associated with the currently accepted vacancy cluster model for the defect. Theoretical calculations suggest that this defect will generate partially filled gap states about 1 eV above the valence band. Data on the photochromic behaviour of bands producing pink colour and their relation to brown colour are presented; these suggest that the pink bands are produced from two independent transitions with ground states close to each other just below the middle of the band gap. Compensation of neutral boron by charge transfer from states associated with brown colour is demonstrated via the correlated increase in neutral boron and decrease in brown colour on high pressure, high temperature treatment to remove the defects causing the brown colour.

Defect forces, defect couples and path integrals in fracture mechanics

International Nuclear Information System (INIS)

Roche, R.L.

1979-07-01

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

Neural Tube Defects

Science.gov (United States)

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

The value of right lateral decubitus position to decrease artificial defect of cardiac anterior wall in 99Tcm-MIBI SPECT myocardial perfusion imaging for women

International Nuclear Information System (INIS)

Huang Kemin; Feng Yanlin; Wen Guanghua; Liang Weitang; Yu Fengwen; Liu Dejun

2013-01-01

showed radioactive filling in right lateral position imaging, 12 cases(24.5%, 12/49) filled markedly and 32 cases(65.3%, 32/49) filled completely. Conclusions: The artificial defects caused by breast of woman mainly present in anterior-middle region and in anterior-apex region of the anterior wall in supine position imaging. The right lateral decubitus position imaging can markedly improve these artificial defects. (authors)

Combined osteoplasty of metaepiphysial defects in total knee arthroplasty with osteoplastic biomaterial

Directory of Open Access Journals (Sweden)

Gavrilov М.А.

2012-12-01

Full Text Available The research goal is to study the results of osteoplastic biomaterials application to reach the improvement of primary and long-term secondary stability of fixation. Materials and methods: 62 patients with bone defect of metaepiphy-sis of type 2 according to AORI have been included into the research. Total knee arthroplasty with osteoplasty of the defect has been carried out in all the patients. In the basic group (n=32 combined osteoplasty has been used, and in comparison group (n=30 cement osteoplasty has been applied. In cases with total arthroplasty in the basic group modifying standard resections, structural autograft of laminar form has been received simultaneously. After preparing the floor of the defect its plasty has been carried out: in the basic group the defect has been filled with osteoconductive biomaterial, and in the comparison group — with polymethylmethacrylate to restore the anatomical configuration of condyles. Besides, before cement fixation of the prosthesis in the basic group the received autograft has been put on the restored implant plateau. Results: Assessing the results during the period from 2 to 4 years objective criteria have included the data of X-ray imaging, biomechanical research and WOMAC test. In the postoperative period significant differences have not been revealed. In the follow-up period in the group with application of the combined osteoplasty joint remodulation of autograft and osteoplastic biomaterial with regenerative restoration of bone tissue of the implant plateau has been observed. Conclusion: The described technique may reduce the relative risk of revision arthroplasty.

COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

Energy Technology Data Exchange (ETDEWEB)

Kook, Sung-Ho [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Lim, Shin-Saeng [School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Kwon, Jungkee [College of Veterinary Medicine, Chonbuk National University, Jeonju (Korea, Republic of); Hwang, Jae-Won; Bae, Cheol-Hyeon [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Seo, Young-Kwon [Research Institute of Biotechnology, Dongguk University, Seoul (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

2014-12-12

Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

International Nuclear Information System (INIS)

Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol; Kwon, Jungkee; Hwang, Jae-Won; Bae, Cheol-Hyeon; Seo, Young-Kwon; Lee, Jeong-Chae

2014-01-01

Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways

Development of fluorapatite cement for dental enamel defects repair.

Science.gov (United States)

Wei, Jie; Wang, Jiecheng; Shan, Wenpeng; Liu, Xiaochen; Ma, Jian; Liu, Changsheng; Fang, Jing; Wei, Shicheng

2011-06-01

In order to restore the badly carious lesion of human dental enamel, a crystalline paste of fluoride substituted apatite cement was synthesized by using the mixture of tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA) and ammonium fluoride. The apatite cement paste could be directly filled into the enamel defects (cavities) to repair damaged dental enamel. The results indicated that the hardened cement was fluorapatite [Ca(10)(PO(4))(6)F(2), FA] with calcium to phosphorus atom molar ratio (Ca/P) of 1.67 and Ca/F ratio of 5. The solubility of FA cement in Tris-HCl solution (pH = 5) was slightly lower than the natural enamel, indicating the FA cement was much insensitive to the weakly acidic solutions. The FA cement was tightly combined with the enamel surface, and there was no obvious difference of the hardness between the FA cement and natural enamel. The extracts of FA cement caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. In addition, the results showed that the FA cement had good mechanical strength, hydrophilicity, and anti-bacterial adhesion properties. The study suggested that using FA cement was simple and promising approach to effectively and conveniently restore enamel defects.

Characterization of vegetative and grain filling periods of winter wheat by stepwise regression procedure. II. Grain filling period

Directory of Open Access Journals (Sweden)

Pržulj Novo

2011-01-01

Full Text Available In wheat, rate and duration of dry matter accumulation and remobilization depend on genotype and growing conditions. The objective of this study was to determine the most appropriate polynomial regression of stepwise regression procedure for describing grain filling period in three winter wheat cultivars. The stepwise regression procedure showed that grain filling is a complex biological process and that it is difficult to offer a simple and appropriate polynomial equation that fits the pattern of changes in dry matter accumulation during the grain filling period, i.e., from anthesis to maximum grain weight, in winter wheat. If grain filling is to be represented with a high power polynomial, quartic and quintic equations showed to be most appropriate. In spite of certain disadvantages, a cubic equation of stepwise regression could be used for describing the pattern of winter wheat grain filling.

TruFit Plug for Repair of Osteochondral Defects-Where Is the Evidence? Systematic Review of Literature.

Science.gov (United States)

Verhaegen, J; Clockaerts, S; Van Osch, G J V M; Somville, J; Verdonk, P; Mertens, P

2015-01-01

Treatment of osteochondral defects remains a challenge in orthopedic surgery. The TruFit plug has been investigated as a potential treatment method for osteochondral defects. This is a biphasic scaffold designed to stimulate cartilage and subchondral bone formation. The aim of this study is to investigate clinical, radiological, and histological efficacy of the TruFit plug in restoring osteochondral defects in the joint. We performed a systematic search in five databases for clinical trials in which patients were treated with a TruFit plug for osteochondral defects. Studies had to report clinical, radiological, or histological outcome data. Quality of the included studies was assessed. Five studies describe clinical results, all indicating improvement at follow-up of 12 months compared to preoperative status. However, two studies reporting longer follow-up show deterioration of early improvement. Radiological evaluation indicates favorable MRI findings regarding filling of the defect and incorporation with adjacent cartilage at 24 months follow-up, but conflicting evidence exists on the properties of the newly formed overlying cartilage surface. None of the included studies showed evidence for bone ingrowth. The few histological data available confirmed these results. There are no data available that support superiority or equality of TruFit compared to conservative treatment or mosaicplasty/microfracture. Further investigation is needed to improve synthetic biphasic implants as therapy for osteochondral lesions. Randomized controlled clinical trials comparing TruFit plugs with an established treatment method are needed before further clinical use can be supported.

On holographic defect entropy

International Nuclear Information System (INIS)

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

2014-01-01

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

NMR study of partially filled skutterudites AxCo4Sb12 (A = Yb, Ba, Sr, Ca) and BaxYbyCo4Sb12.

Science.gov (United States)

Tian, Yefan; Sirusi, Ali; Ross, Joseph; Ballikaya, Sedat; Uher, Ctirad; Chen, Yuqi; Sekine, Chihiro

Partially filled Co-Sb skutterudites have been of considerable interest as thermoelectric materials, particularly with multiple filling for which high ZT values can be obtained. This is due in part to control of phonon thermal conductivity, but also the change in composition leads to subtle changes in electronic behavior as well as magnetism due both to rare earth filler atoms and to native defects. We measured 59Co NMR on several partially filled AxCo4Sb12 skutterudites in order to investigate such behavior. From the T-dependent NMR shifts along with T1 relaxation times we can separate metallic shift contributions from those due to local moments. We compare the results to predicted band-edge behavior with multiple minima, and the estimated g factors, by matching this behavior to transport measurements. Also the behavior of Yb-filled samples provides an estimate of the conduction band mediation of the magnetic response, and we also find magnetic shifts in Ba-doped skutterudite which we address in terms of Co mixed-valence behavior. This work was supported by the Robert A. Welch Foundation, Grant No. A-1526. Synthesis work was partly supported by the Center for Solar and Thermal Energy Conversion and a Grant-in-Aid for Scientific Research (B) (No. 23340092) from the Japan Society.

Placement of endosseous implant in infected alveolar socket with large fenestration defect: A comparative case report

Directory of Open Access Journals (Sweden)

Balaji Anitha

2010-01-01

Full Text Available Placement of endosseous implants into infected bone is often deferred or avoided due to fear of failure. However, with the development of guided bone regeneration [GBR], some implantologists have reported successful implant placement in infected sockets, even those with fenestration defects. We had the opportunity to compare the osseointegration of an immediate implant placed in an infected site associated with a large buccal fenestration created by the removal of a root stump with that of a delayed implant placed 5 years after extraction. Both implants were placed in the same patient, in the same dental quadrant by the same implantologist. GBR was used with the fenestration defect being filled with demineralized bone graftFNx01 and covered with collagen membraneFNx08. Both implants were osseointegrated and functional when followed up after 12 months.

Iron filled carbon nanostructures from different precursors

International Nuclear Information System (INIS)

Costa, S.; Borowiak-Palen, E.; Bachmatiuk, A.; Ruemmeli, M.H.; Gemming, T.; Kalenczuk, R.J.

2008-01-01

Here, we present a study on the synthesis of different nanostructures with one single-step in situ filling (encapsulation) via carbon vapor deposition (CVD). Ferrocene, acetylferrocene and iron (II) nitrate as iron precursors were explored. The application of each of these compounds resulted in different carbon nanomaterials such as: iron filled multiwalled carbon nanotubes with a low filling ratio (Fe-MWCNT), iron filled nanocapsules and unfilled MWCNT. The as-produced samples were purified by high temperature annealing and acid treatment. The purified materials were characterised using transmission electron microscopy (TEM) and Raman spectroscopy

46 CFR 98.25-65 - Filling density.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may...

Increasing Polymer Solar Cell Fill Factor by Trap-Filling with F4-TCNQ at Parts Per Thousand Concentration.

Science.gov (United States)

Yan, Han; Manion, Joseph G; Yuan, Mingjian; García de Arquer, F Pelayo; McKeown, George R; Beaupré, Serge; Leclerc, Mario; Sargent, Edward H; Seferos, Dwight S

2016-08-01

Intrinsic traps in organic semiconductors can be eliminated by trap-filling with F4-TCNQ. Photovoltaic tests show that devices with F4-TCNQ at parts per thousand concentration outperform control devices due to an improved fill factor. Further studies confirm the trap-filling pathway and demonstrate the general nature of this finding. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Filled aperture concepts for the Terrestrial Planet Finder

Science.gov (United States)

Ridgway, Stephen T.

2003-02-01

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

Defects in semiconductors

CERN Document Server

Romano, Lucia; Jagadish, Chennupati

2015-01-01

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

Increased dependence on slow filling for left ventricular diastolic filling in patients with coronary artery disease and a depressed systolic function

International Nuclear Information System (INIS)

Yamagishi, Takashi; Ozaki, Masaharu; Furutani, Yuhji; Yamamoto, Kouzo; Saeki, Atsushi; Satoh, Shinichi; Kusukawa, Reizo

1990-01-01

Contributions of rapid filling, slow filling and atrial systole to the left ventricular(LV) filling volume were analyzed with the use of radionuclide ventriculography at rest, both globally and regionally, in 34 patients with isolated disease of the left anterior descending coronary artery. The patients included 17 with a normal ejection fraction (EF≥50%; group 1) and 17 with a depressed EF (<50%; group 2), and the data were compared with those obtained from 13 normal subjects. A computer program subdivided the LV image into 4 regions, and time-activity curves were constructed globally and regionally by reverse-gating from the R wave. In both groups the contribution of rapid filling to the LV filling volume was decreased significantly in the affected septal and apical regions, and in the global left ventricle compared with that in normal subjects. In group 1, the contribution of atrial systole showed an increase in these affected regions and in the global left ventricle. In contrast, in group 2, the atrial contribution was not increased globally or regionally as much as was expected. However, the contribution of slow filling was either increased significantly or tended to increase in the affected regions and in the global left ventricle. There were negative correlations between the contribution of rapid filling and that of slow filling in the global left ventricle (r=-0.73, p<0.001) and in each of the septal, apical and lateral regions (r≥-0.60, p<0.001), which suggested that the contribution of slow filling as well as of atrial systole undergoes an increase as rapid filling is impaired. Thus, in patients with coronary artery disease, the left ventricle relies on slow filling as well as atrial systole to affect diastolic LV filling in the affected regions and in the global left ventricle in the presence of LV systolic dysfunction. (author)

Repair of articular cartilage defects in the knee with autologous iliac crest cartilage in a rabbit model.

Science.gov (United States)

Jing, Lizhong; Zhang, Jiying; Leng, Huijie; Guo, Qinwei; Hu, Yuelin

2015-04-01

To demonstrate that iliac crest cartilage may be used to repair articular cartilage defects in the knees of rabbits. Full-thickness cartilage defects were created in the medial femoral condyle on both knees of 36 New Zealand white rabbits. The 72 defects were randomly assigned to be repaired with ipsilateral iliac crest cartilage (Group I), osteochondral tissues removed at defect creation (Group II), or no treatment (negative control, Group III). Animals were killed at 6, 12, and 24 weeks post-operatively. The repaired tissues were harvested for magnetic resonance imaging (MRI), histological studies (haematoxylin and eosin and immunohistochemical staining), and mechanical testing. At 6 weeks, the iliac crest cartilage graft was not yet well integrated with the surrounding articular cartilage, but at 12 weeks, the graft deep zone had partial ossification. By 24 weeks, the hyaline cartilage-like tissue was completely integrated with the surrounding articular cartilage. Osteochondral autografts showed more rapid healing than Group I at 6 weeks and complete healing at 12 weeks. Untreated defects were concave or partly filled with fibrous tissue throughout the study. MRI showed that Group I had slower integration with surrounding normal cartilage compared with Group II. The mechanical properties of Group I were significantly lower than those of Group II at 12 weeks, but this difference was not significant at 24 weeks. Iliac crest cartilage autografts were able to repair knee cartilage defects with hyaline cartilage and showed comparable results with osteochondral autografts in the rabbit model.

Implantation of a novel biologic and hybridized tissue engineered bioimplant in large tendon defect: an in vivo investigation.

Science.gov (United States)

Oryan, Ahmad; Moshiri, Ali; Parizi, Abdolhamid Meimandi; Maffulli, Nicola

2014-02-01

Surgical reconstruction of large Achilles tendon defects is technically demanding. There is no standard method, and tissue engineering may be a valuable option. We investigated the effects of 3D collagen and collagen-polydioxanone sheath (PDS) implants on a large tendon defect model in rabbits. Ninety rabbits were divided into three groups: control, collagen, and collagen-PDS. In all groups, 2 cm of the left Achilles tendon were excised and discarded. A modified Kessler suture was applied to all injured tendons to retain the gap length. The control group received no graft, the treated groups were repaired using the collagen only or the collagen-PDS prostheses. The bioelectrical characteristics of the injured areas were measured at weekly intervals. The animals were euthanized at 60 days after the procedure. Gross, histopathological and ultrastructural morphology and biophysical characteristics of the injured and intact tendons were investigated. Another 90 pilot animals were also used to investigate the inflammatory response and mechanism of graft incorporation during tendon healing. The control tendons showed severe hyperemia and peritendinous adhesion, and the gastrocnemius muscle of the control animals showed severe atrophy and fibrosis, with a loose areolar connective tissue filling the injured area. The tendons receiving either collagen or collagen-PDS implants showed lower amounts of peritendinous adhesion, hyperemia and muscle atrophy, and a dense tendon filled the defect area. Compared to the control tendons, application of collagen and collagen-PDS implants significantly improved water uptake, water delivery, direct transitional electrical current and tissue resistance to direct transitional electrical current. Compared to the control tendons, both prostheses showed significantly increased diameter, density and alignment of the collagen fibrils and maturity of the tenoblasts at ultrastructure level. Both prostheses influenced favorably tendon healing

Fibrous metaphyseal defects

International Nuclear Information System (INIS)

Ritschl, P.; Hajek, P.C.; Pechmann, U.

1989-01-01

Sixteen patients with fibrous metaphyseal defects were examined with both plain radiography and magnetic resonance (MR) imaging. Depending on the age of the fibrous metaphyseal defects, characteristic radiomorphologic changes were found which correlated well with MR images. Following intravenous Gadolinium-DTPA injection, fibrous metaphyseal defects invariably exhibited a hyperintense border and signal enhancement. (orig./GDG)

Safety Distances for hydrogen filling stations

Energy Technology Data Exchange (ETDEWEB)

Matthijsen, A. J. C. M.; Kooi, E. S.

2005-07-01

In the Netherlands there is a growing interest in using natural gas as a transport fuel. The most important drivers behind this development are formed by poor inner city air quality and the decision to close several LPG filling stations. Dwellings are not allowed within the safety distances of 45 or 110 meters from the tanker filling point of these LPG stations, depending on the capacity of the station. Another driver is global warming. We are carrying out a study on station supply, compression, storage and filling for natural gas stations, and a similar, simultaneous study on hydrogen as a followup to our risk analysis for the hydrogen filling station in Amsterdam. Here, three buses drive on hydrogen as part of the European CUTE project. Driving on natural gas is an important step in the transition to cars on hydrogen. This study was commissioned by the Dutch Ministry of Spatial Planning, Housing and the Environment to advise on external safety aspects of future hydrogen filling stations. According to Dutch law homes may not be built within an individual risk contour of 10-6 per year of a dangerous object, such as a plant with hazardous materials or a filling station. An individual risk contour of 10-6 is represented by a line around a dangerous object that connects locations with an individual risk level of 10-6 per year. An individual 'located' within this contour line has a chance of one per million per year or more to be killed as a result of an accident caused by this object. The longest distance between the object and such a contour is called a 'safety distance'. A study on safety distances is now in progress for different kinds of hydrogen filling stations (e. g. gaseous and liquid hydrogen) and for different capacities, such as big, medium and small stations. The focus is on different kinds of hydrogen production and the hydrogen supply of the filling station. To decide on the design and supply of the hydrogen station, we examined the

Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association with Mayer-Rokitansky-Küster-Hauser syndrome in co-occurrence: two case reports and a review of the literature.

Science.gov (United States)

Bjørsum-Meyer, Thomas; Herlin, Morten; Qvist, Niels; Petersen, Michael B

2016-12-21

The vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome are rare conditions. We aimed to present two cases with the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser co-occurrence from our local surgical center and through a systematic literature search detect published cases. Furthermore, we aimed to collect existing knowledge in the embryopathogenesis and genetics in order to discuss a possible link between the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome. Our first case was a white girl delivered by caesarean section at 37 weeks of gestation; our second case was a white girl born at a gestational age of 40 weeks. A co-occurrence of vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome was diagnosed in both cases. We performed a systematic literature search in PubMed ((VACTERL) OR (VATER)) AND ((MRKH) OR (Mayer-Rokitansky-Küster-Hauser) OR (mullerian agenesis) OR (mullerian aplasia) OR (MURCS)) without limitations. A similar search was performed in Embase and the Cochrane library. We added two cases from our local center. All cases (n = 9) presented with anal atresia and renal defect. Vertebral defects were present in eight patients. Rectovestibular fistula was confirmed in seven patients. Along with the uterovaginal agenesis, fallopian tube aplasia appeared in five of nine cases and in two cases ovarian involvement also existed. The co-occurrence of the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal

A Copolymer Scaffold Functionalized with Nanodiamond Particles Enhances Osteogenic Metabolic Activity and Bone Regeneration.

Science.gov (United States)

Yassin, Mohammed A; Mustafa, Kamal; Xing, Zhe; Sun, Yang; Fasmer, Kristine Eldevik; Waag, Thilo; Krueger, Anke; Steinmüller-Nethl, Doris; Finne-Wistrand, Anna; Leknes, Knut N

2017-06-01

Functionalizing polymer scaffolds with nanodiamond particles (nDPs) has pronounced effect on the surface properties, such as improved wettability, an increased active area and binding sites for cellular attachment and adhesion, and increased ability to immobilize biomolecules by physical adsorption. This study aims to evaluate the effect of poly(l-lactide-co-ε-caprolactone) (poly(LLA-co-CL)) scaffolds, functionalized with nDPs, on bone regeneration in a rat calvarial critical size defect. Poly(LLA-co-CL) scaffolds functionalized with nDPs are also compared with pristine scaffolds with reference to albumin adsorption and seeding efficiency of bone marrow stromal cells (BMSCs). Compared with pristine scaffolds, the experimental scaffolds exhibit a reduction in albumin adsorption and a significant increase in the seeding efficiency of BMSCs (p = 0.027). In the calvarial defects implanted with BMSC-seeded poly(LLA-co-CL)/nDPs scaffolds, live imaging at 12 weeks discloses a significant increase in osteogenic metabolic activity (p = 0.016). Microcomputed tomography, confirmed by histological data, reveals a substantial increase in bone volume (p = 0.021). The results show that compared with conventional poly(LLA-co-CL) scaffolds those functionalized with nDPs promote osteogenic metabolic activity and mineralization capacity. It is concluded that poly(LLA-co-CL) composite matrices functionalized with nDPs enhance osteoconductivity and therefore warrant further study as potential scaffolding material for bone tissue engineering. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficacy of rhBMP-2 Loaded PCL/β-TCP/bdECM Scaffold Fabricated by 3D Printing Technology on Bone Regeneration

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Eun-Bin Bae

2018-01-01

Full Text Available This study was undertaken to evaluate the effect of 3D printed polycaprolactone (PCL/β-tricalcium phosphate (β-TCP scaffold containing bone demineralized and decellularized extracellular matrix (bdECM and human recombinant bone morphogenetic protein-2 (rhBMP-2 on bone regeneration. Scaffolds were divided into PCL/β-TCP, PCL/β-TCP/bdECM, and PCL/β-TCP/bdECM/BMP groups. In vitro release kinetics of rhBMP-2 were determined with respect to cell proliferation and osteogenic differentiation. These three reconstructive materials were implanted into 8 mm diameter calvarial bone defect in male Sprague-Dawley rats. Animals were sacrificed four weeks after implantation for micro-CT, histologic, and histomorphometric analyses. The findings obtained were used to calculate new bone volumes (mm3 and new bone areas (%. Excellent cell bioactivity was observed in the PCL/β-TCP/bdECM and PCL/β-TCP/bdECM/BMP groups, and new bone volume and area were significantly higher in the PCL/β-TCP/bdECM/BMP group than in the other groups (p<.05. Within the limitations of this study, bdECM printed PCL/β-TCP scaffolds can reproduce microenvironment for cells and promote adhering and proliferating the cells onto scaffolds. Furthermore, in the rat calvarial defect model, the scaffold which printed rhBMP-2 loaded bdECM stably carries rhBMP-2 and enhances bone regeneration confirming the possibility of bdECM as rhBMP-2 carrier.

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

Science.gov (United States)

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

A Modified Rabbit Ulna Defect Model for Evaluating Periosteal Substitutes in Bone Engineering: A Pilot Study

Energy Technology Data Exchange (ETDEWEB)

El Backly, Rania M. [DIMES, University of Genova, Genova (Italy); IRCCS AOU San Martino–IST Istituto Nazionale per la Ricerca sul Cancro, Genova (Italy); Faculty of Dentistry, Alexandria University, Alexandria (Egypt); Chiapale, Danilo [IRCCS AOU San Martino–IST Istituto Nazionale per la Ricerca sul Cancro, Genova (Italy); Muraglia, Anita [Biorigen S.R.L., Genova (Italy); Tromba, Giuliana [Sincrotrone Trieste S.C.P.A., Trieste (Italy); Ottonello, Chiara [Biorigen S.R.L., Genova (Italy); Santolini, Federico [IRCCS AOU San Martino–IST Istituto Nazionale per la Ricerca sul Cancro, Genova (Italy); Cancedda, Ranieri; Mastrogiacomo, Maddalena, E-mail: maddalena.mastrogiacomo@unige.it [DIMES, University of Genova, Genova (Italy); IRCCS AOU San Martino–IST Istituto Nazionale per la Ricerca sul Cancro, Genova (Italy)

2015-01-06

The present work defines a modified critical size rabbit ulna defect model for bone regeneration in which a non-resorbable barrier membrane was used to separate the radius from the ulna to create a valid model for evaluation of tissue-engineered periosteal substitutes. Eight rabbits divided into two groups were used. Critical defects (15 mm) were made in the ulna completely eliminating periosteum. For group I, defects were filled with a nanohydroxyapatite poly(ester urethane) scaffold soaked in PBS and left as such (group Ia) or wrapped with a tissue-engineered periosteal substitute (group Ib). For group II, an expanded-polytetrafluoroethylene (e-PTFE) (GORE-TEX{sup ®}) membrane was inserted around the radius then the defects received either scaffold alone (group IIa) or scaffold wrapped with periosteal substitute (group IIb). Animals were euthanized after 12–16 weeks, and bone regeneration was evaluated by radiography, computed microtomography (μCT), and histology. In the first group, we observed formation of radio-ulnar synostosis irrespective of the treatment. This was completely eliminated upon placement of the e-PTFE (GORE-TEX{sup ®}) membrane in the second group of animals. In conclusion, modification of the model using a non-resorbable e-PTFE membrane to isolate the ulna from the radius was a valuable addition allowing for objective evaluation of the tissue-engineered periosteal substitute.

A Modified Rabbit Ulna Defect Model for Evaluating Periosteal Substitutes in Bone Engineering: A Pilot Study

International Nuclear Information System (INIS)

El Backly, Rania M.; Chiapale, Danilo; Muraglia, Anita; Tromba, Giuliana; Ottonello, Chiara; Santolini, Federico; Cancedda, Ranieri; Mastrogiacomo, Maddalena

2015-01-01

The present work defines a modified critical size rabbit ulna defect model for bone regeneration in which a non-resorbable barrier membrane was used to separate the radius from the ulna to create a valid model for evaluation of tissue-engineered periosteal substitutes. Eight rabbits divided into two groups were used. Critical defects (15 mm) were made in the ulna completely eliminating periosteum. For group I, defects were filled with a nanohydroxyapatite poly(ester urethane) scaffold soaked in PBS and left as such (group Ia) or wrapped with a tissue-engineered periosteal substitute (group Ib). For group II, an expanded-polytetrafluoroethylene (e-PTFE) (GORE-TEX ® ) membrane was inserted around the radius then the defects received either scaffold alone (group IIa) or scaffold wrapped with periosteal substitute (group IIb). Animals were euthanized after 12–16 weeks, and bone regeneration was evaluated by radiography, computed microtomography (μCT), and histology. In the first group, we observed formation of radio-ulnar synostosis irrespective of the treatment. This was completely eliminated upon placement of the e-PTFE (GORE-TEX ® ) membrane in the second group of animals. In conclusion, modification of the model using a non-resorbable e-PTFE membrane to isolate the ulna from the radius was a valuable addition allowing for objective evaluation of the tissue-engineered periosteal substitute.

Defect detection based on extreme edge of defective region histogram

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Zouhir Wakaf

2018-01-01

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

[Treatment of acute full-thickness chondral defects with high molecular weight hyaluronic acid; an experimental model].

Science.gov (United States)

Figueroa, D; Espinosa, M; Calvo, R; Scheu, M; Valderrama, J J; Gallegos, M; Conget, P

2014-01-01

To evaluate the effect of 2 different protocols of intra-articular hyaluronic acid (HA, hylan G-F20) to articular cartilage regeneration in acute full-thickness chondral defects. Full-thickness chondral defects of 3 x 6 mm were performed into the lateral femoral condyles of New Zealand rabbits, treated with a single or three doses of HA. The animals were sacrified at 12 weeks and the regenerated tissue was evaluated by direct observation and histology with the ICRS scale. Macroscopically, in both groups treated with HA the defects were filled with irregular tissue with areas similar to hyaline cartilage and others in which depressed areas with exposed subchondral bone were observed. Histological analysis showed in both groups treated with HA a hyaline-like cartilage compared to control group. However, the score of the International Cartilage Repair Society (ICRS) scale did not show differences between the groups treated with HA. The use of single dose or 3 doses of AH in acute chondral lesions has a limited and similar benefit in articular cartilage regeneration. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

Effects of selective attention on perceptual filling-in.

Science.gov (United States)

De Weerd, P; Smith, E; Greenberg, P

2006-03-01

After few seconds, a figure steadily presented in peripheral vision becomes perceptually filled-in by its background, as if it "disappeared". We report that directing attention to the color, shape, or location of a figure increased the probability of perceiving filling-in compared to unattended figures, without modifying the time required for filling-in. This effect could be augmented by boosting attention. Furthermore, the frequency distribution of filling-in response times for attended figures could be predicted by multiplying the frequencies of response times for unattended figures with a constant. We propose that, after failure of figure-ground segregation, the neural interpolation processes that produce perceptual filling-in are enhanced in attended figure regions. As filling-in processes are involved in surface perception, the present study demonstrates that even very early visual processes are subject to modulation by cognitive factors.

Efficacy of MTA and CEM Cement with Collagen Membranes for Treatment of Class II Furcation Defects.

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Habib Ollah Ghanbari

2014-06-01

Full Text Available This study aimed to compare the efficacy of MTA and CEM cement in Class II furcation defects in human mandibular molars.Forty furcation defects were treated in 16 patients with chronic periodontitis. The clinical parameters of probing depth (PD, vertical and horizontal clinical attachment levels (VCAL and HCAL, open vertical and horizontal furcation depths (OVFD and OHFD, and gingival margin level (GML were measured at baseline and at 3- and 6-month (re-entry surgery postoperatively. Data were analyzed at a significance level of P<0.05.Use of MTA and CEM caused significant decreases in PD, VCAL, HCAL, OVFD and OHFD at re-entry, with no statistically significant differences between the two treatment options in soft and hard tissue parameters.Both treatment modalities caused significant gains in attachment levels and bone fills, proving efficacy for treatment of Class II furcation involvements.

Light Enhanced Hydrofluoric Acid Passivation: A Sensitive Technique for Detecting Bulk Silicon Defects

Science.gov (United States)

Grant, Nicholas E.

2016-01-01

A procedure to measure the bulk lifetime (>100 µsec) of silicon wafers by temporarily attaining a very high level of surface passivation when immersing the wafers in hydrofluoric acid (HF) is presented. By this procedure three critical steps are required to attain the bulk lifetime. Firstly, prior to immersing silicon wafers into HF, they are chemically cleaned and subsequently etched in 25% tetramethylammonium hydroxide. Secondly, the chemically treated wafers are then placed into a large plastic container filled with a mixture of HF and hydrochloric acid, and then centered over an inductive coil for photoconductance (PC) measurements. Thirdly, to inhibit surface recombination and measure the bulk lifetime, the wafers are illuminated at 0.2 suns for 1 min using a halogen lamp, the illumination is switched off, and a PC measurement is immediately taken. By this procedure, the characteristics of bulk silicon defects can be accurately determined. Furthermore, it is anticipated that a sensitive RT surface passivation technique will be imperative for examining bulk silicon defects when their concentration is low (<1012 cm-3). PMID:26779939

The relationship between the retinal image quality and the refractive index of defects arising in IOL: numerical analysis

Science.gov (United States)

Geniusz, Malwina

2017-09-01

The best treatment for cataract patients, which allows to restore clear vision is implanting an artificial intraocular lens (IOL). The image quality of the lens has a significant impact on the quality of patient's vision. After a long exposure the implant to aqueous environment some defects appear in the artificial lenses. The defects generated in the IOL have different refractive indices. For example, glistening phenomenon is based on light scattering on the oval microvacuoles filled with an aqueous humor which refractive index value is about 1.34. Calcium deposits are another example of lens defects and they can be characterized by the refractive index 1.63. In the presented studies it was calculated how the difference between the refractive indices of the defect and the refractive index of the lens material affects the quality of image. The OpticStudio Professional program (from Radiant Zemax, LLC) was used for the construction of the numerical model of the eye with IOL and to calculate the characteristics of the retinal image. Retinal image quality was described in such characteristics as Point Spread Function (PSF) and the Optical Transfer Function with amplitude and phase. The results show a strong correlation between the refractive indices difference and retinal image quality.

Fully Ab-Initio Determination of the Thermoelectric Properties of Half-Heusler NiTiSn: Crucial Role of Interstitial Ni Defects.

Science.gov (United States)

Berche, Alexandre; Jund, Philippe

2018-05-23

For thermoelectric applications, ab initio methods generally fail to predict the transport properties of the materials because of their inability to predict properly the carrier concentrations that control the electronic properties. In this work, a methodology to fill in this gap is applied on the NiTiSn half Heusler phase. For that, we show that the main defects act as donor of electrons and are responsible of the electronic properties of the material. Indeed, the presence of Ni i interstitial defects explains the experimental valence band spectrum and its associated band gap reported in the literature. Moreover, combining the DOS of the solid solutions with the determination of the energy of formation of charged defects, we show that Ni i defects are also responsible of the measured carrier concentration in experimentally supposed "pure" NiTiSn compounds. Subsequently the thermoelectric properties of NiTiSn can be calculated using a fully ab initio description and an overall correct agreement with experiments is obtained. This methodology can be extended to predict the result of extrinsic doping and thus to select the most efficient dopant for specific thermoelectric applications.

Radiological Assessment of Bioengineered Bone in a Muscle Flap for the Reconstruction of Critical-Size Mandibular Defect

Science.gov (United States)

Al-Fotawei, Randa; Ayoub, Ashraf F.; Heath, Neil; Naudi, Kurt B.; Tanner, K. Elizabeth; Dalby, Matthew J.; McMahon, Jeremy

2014-01-01

This study presents a comprehensive radiographic evaluation of bone regeneration within a pedicled muscle flap for the reconstruction of critical size mandibular defect. The surgical defect (20 mm×15 mm) was created in the mandible of ten experimental rabbits. The masseter muscle was adapted to fill the surgical defect, a combination of calcium sulphate/hydroxyapatite cement (CERAMENT™ |SPINE SUPPORT), BMP-7 and rabbit mesenchymal stromal cells (rMSCs) was injected inside the muscle tissue. Radiographic assessment was carried out on the day of surgery and at 4, 8, and 12 weeks postoperatively. At 12 weeks, the animals were sacrificed and cone beam computerized tomography (CBCT) scanning and micro-computed tomography (µ-CT) were carried out. Clinically, a clear layer of bone tissue was identified closely adherent to the border of the surgical defect. Sporadic radio-opaque areas within the surgical defect were detected radiographically. In comparison with the opposite non operated control side, the estimated quantitative scoring of the radio-opacity was 46.6% ±15, the mean volume of the radio-opaque areas was 63.4% ±20. Areas of a bone density higher than that of the mandibular bone (+35% ±25%) were detected at the borders of the surgical defect. The micro-CT analysis revealed thinner trabeculae of the regenerated bone with a more condensed trabecular pattern than the surrounding native bone. These findings suggest a rapid deposition rate of the mineralised tissue and an active remodelling process of the newly regenerated bone within the muscle flap. The novel surgical model of this study has potential clinical application; the assessment of bone regeneration using the presented radiolographic protocol is descriptive and comprehensive. The findings of this research confirm the remarkable potential of local muscle flaps as local bioreactors to induce bone formation for reconstruction of maxillofacial bony defects. PMID:25226170

Radiological assessment of bioengineered bone in a muscle flap for the reconstruction of critical-size mandibular defect.

Directory of Open Access Journals (Sweden)

Randa Al-Fotawei

Full Text Available This study presents a comprehensive radiographic evaluation of bone regeneration within a pedicled muscle flap for the reconstruction of critical size mandibular defect. The surgical defect (20 mm × 15 mm was created in the mandible of ten experimental rabbits. The masseter muscle was adapted to fill the surgical defect, a combination of calcium sulphate/hydroxyapatite cement (CERAMENT™ |SPINE SUPPORT, BMP-7 and rabbit mesenchymal stromal cells (rMSCs was injected inside the muscle tissue. Radiographic assessment was carried out on the day of surgery and at 4, 8, and 12 weeks postoperatively. At 12 weeks, the animals were sacrificed and cone beam computerized tomography (CBCT scanning and micro-computed tomography (µ-CT were carried out. Clinically, a clear layer of bone tissue was identified closely adherent to the border of the surgical defect. Sporadic radio-opaque areas within the surgical defect were detected radiographically. In comparison with the opposite non operated control side, the estimated quantitative scoring of the radio-opacity was 46.6% ± 15, the mean volume of the radio-opaque areas was 63.4% ± 20. Areas of a bone density higher than that of the mandibular bone (+35% ± 25% were detected at the borders of the surgical defect. The micro-CT analysis revealed thinner trabeculae of the regenerated bone with a more condensed trabecular pattern than the surrounding native bone. These findings suggest a rapid deposition rate of the mineralised tissue and an active remodelling process of the newly regenerated bone within the muscle flap. The novel surgical model of this study has potential clinical application; the assessment of bone regeneration using the presented radiolographic protocol is descriptive and comprehensive. The findings of this research confirm the remarkable potential of local muscle flaps as local bioreactors to induce bone formation for reconstruction of maxillofacial bony defects.

Surgical membranes as directional delivery devices to generate tissue: testing in an ovine critical sized defect model.

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Melissa L Knothe Tate

Full Text Available Pluripotent cells residing in the periosteum, a bi-layered membrane enveloping all bones, exhibit a remarkable regenerative capacity to fill in critical sized defects of the ovine femur within two weeks of treatment. Harnessing the regenerative power of the periosteum appears to be limited only by the amount of healthy periosteum available. Here we use a substitute periosteum, a delivery device cum implant, to test the hypothesis that directional delivery of endogenous periosteal factors enhances bone defect healing.Newly adapted surgical protocols were used to create critical sized, middiaphyseal femur defects in four groups of five skeletally mature Swiss alpine sheep. Each group was treated using a periosteum substitute for the controlled addition of periosteal factors including the presence of collagen in the periosteum (Group 1, periosteum derived cells (Group 2, and autogenic periosteal strips (Group 3. Control group animals were treated with an isotropic elastomer membrane alone. We hypothesized that periosteal substitute membranes incorporating the most periosteal factors would show superior defect infilling compared to substitute membranes integrating fewer factors (i.e. Group 3>Group 2>Group 1>Control.Based on micro-computed tomography data, bone defects enveloped by substitute periosteum enabling directional delivery of periosteal factors exhibit superior bony bridging compared to those sheathed with isotropic membrane controls (Group 3>Group 2>Group 1, Control. Quantitative histological analysis shows significantly increased de novo tissue generation with delivery of periosteal factors, compared to the substitute periosteum containing a collagen membrane alone (Group 1 as well as compared to the isotropic control membrane. Greatest tissue generation and maximal defect bridging was observed when autologous periosteal transplant strips were included in the periosteum substitute.Periosteum-derived cells as well as other factors

Biomechanical properties: effects of low-level laser therapy and Biosilicate® on tibial bone defects in osteopenic rats.

Science.gov (United States)

Fangel, Renan; Bossini, Paulo S; Renno, Ana Cláudia; Granito, Renata N; Wang, Charles C; Nonaka, Keico O; Driusso, Patricia; Parizotto, Nivaldo A; Oishi, Jorge

2014-12-30

The aim of this study was to investigate the effects of laser therapy and Biosilicate® on the biomechanical properties of bone callus in osteopenic rats. Fifty female Wistar rats were equally divided into 5 groups (n=10/group): osteopenic rats with intact tibiae (SC); osteopenic rats with unfilled and untreated tibial bone defects (OC); osteopenic rats whose bone defects were treated with Biosilicate® (B); osteopenic rats whose bone defects were treated with 830-nm laser, at 120 J/cm2 (L120) and osteopenic rats whose bone defects were treated with Biosilicate® and 830-nm laser, at 120 J/cm2 (BL120). Ovariectomy (OVX) was used to induce osteopenia. A non-critical bone defect was created on the tibia of the osteopenic animals 8 weeks after OVX. In Biosilicate® groups, bone defects were completely filled with the biomaterial. For the laser therapy, an 830-nm laser, 120 J/cm2 was used. On day 14 postsurgery, rats were euthanized, and tibiae were removed for biomechanical analysis. Maximal load and energy absorption were higher in groups B and BL120, according to the indentation test. Animals submitted to low-level laser therapy (LLLT) did not show any significant biomechanical improvement, but the association between Biosilicate® and LLLT was shown to be efficient to enhance callus biomechanical properties. Conversely, no differences were found between study groups in the bending test. Biosilicate® alone or in association with low level laser therapy improves biomechanical properties of tibial bone callus in osteopenic rats.

[Use of the induced membrane technique for the treatment of bone defects in the hand or wrist, in emergency].

Science.gov (United States)

Flamans, B; Pauchot, J; Petite, H; Blanchet, N; Rochet, S; Garbuio, P; Tropet, Y; Obert, L

2010-10-01

A prospective study is reported concerning 11 cases of bone defect of the hand and wrist treated by the induced membrane technique. Ten men and one woman with an average age of 49 yrs (17-72) sustained a high-energy trauma with severe mutilation of digit and hand but with intact pulp. Eight cases of open finger fractures with composite loss of substance and three cases of bone and joint infection (thumb, wrist, fifth finger) were included. All cases were treated by the induced membrane technique which consists in stable fixation, flap if necessary, and in filling the bone defect by a cement methyl methacrylate polymere (PMMA) spacer. A secondary procedure at two months is needed where the cement is removed and the void is filled by cancellous bone. The key point of this induced membrane technique is to respect the foreign body membrane which formed around the cement spacer creating a biologic chamber. Bone union was evaluated prospectively by X-ray and CT scan by a surgeon not involved in the treatment. Failure was defined as non-union at one year, or uncontrolled sepsis at one month. Two cases failed to achieve bone union. No septic complications occurred and all septic cases were controlled. In nine cases, bone union was achieved within four months (three to 12). Evidence of osteoid formation was determined by a bone biopsy in one case. Masquelet first reported 35 cases of large tibial non-union defects treated by the induced membrane technique. The cement spacer promotes foreign body membrane induction constituting a biological chamber. Works on animal models reported by Pellissier and Viateau demonstrated membrane properties: secretion of growths factors (VEGF, TGF beta1, BMP2) and osteoinductive cellular activity. The induced membrane seems to mimic a neoperiosteum. This technique is useful in emergency or septic conditions where bone defects cannot be treated by shortening. It avoids microsurgery and is limited by availability of cancellous bone. Copyright �

Simultaneous in vivo comparison of water-filled and air-filled pressure measurement catheters: Implications for good urodynamic practice.

Science.gov (United States)

Gammie, A; Abrams, P; Bevan, W; Ellis-Jones, J; Gray, J; Hassine, A; Williams, J; Hashim, H

2016-11-01

This study aimed to evaluate whether the pressure readings obtained from air-filled catheters (AFCs) are the same as the readings from simultaneously inserted water-filled catheters (WFCs). It also aimed to make any possible recommendations for the use of AFCs to conform to International Continence Society (ICS) Good Urodynamic Practices (GUP). Female patients undergoing urodynamic studies in a single center had water-filled and air-filled catheters simultaneously measuring abdominal and intravesical pressure during filling with saline and during voiding. The pressures recorded by each system at each event during the test were compared using paired t-test and Bland-Altman analyses. 62 patients were recruited, of whom 51 had pressures that could be compared during filling, and 23 during voiding. On average, the pressures measured by the two systems were not significantly different during filling and at maximum flow, but the values for a given patient were found to differ by up to 10 cmH 2 O. This study shows that AFCs and WFCs cannot be assumed to register equal values of pressure. It has further shown that even when the p det readings are compared with their value at the start of a test, a divergence of values of up to 10 cmH 2 O remains. If AFCs are used, care must be taken to compensate for any p det variations that occur during patient movement. Before AFCs are adopted, new normal values for resting pressures need to be developed to allow good quality AFC pressure readings to be made. Neurourol. Urodynam. 35:926-933, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

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

DEFF Research Database (Denmark)

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

2013-01-01

-section images from Micro-computed Tomography scans. Results. All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between...

Selective filling of Photonic Crystal Fibres

DEFF Research Database (Denmark)

Nielsen, Kristian; Noordegraaf, Danny; Sørensen, Thorkild

2005-01-01

A model for calculating the time necessary for filling one or more specific holes in a photonic crystal fibre is made. This model is verified for water, and its enabling potential is illustrated by a polymer application. Selective filling of the core in an air-guide photonic crystal fibre...

Peroxisomes in Different Skeletal Cell Types during Intramembranous and Endochondral Ossification and Their Regulation during Osteoblast Differentiation by Distinct Peroxisome Proliferator-Activated Receptors.

Directory of Open Access Journals (Sweden)

Guofeng Qian

Full Text Available Ossification defects leading to craniofacial dysmorphism or rhizomelia are typical phenotypes in patients and corresponding knockout mouse models with distinct peroxisomal disorders. Despite these obvious skeletal pathologies, to date no careful analysis exists on the distribution and function of peroxisomes in skeletal tissues and their alterations during ossification. Therefore, we analyzed the peroxisomal compartment in different cell types of mouse cartilage and bone as well as in primary cultures of calvarial osteoblasts. The peroxisome number and metabolism strongly increased in chondrocytes during endochondral ossification from the reserve to the hypertrophic zone, whereas in bone, metabolically active osteoblasts contained a higher numerical abundance of this organelle than osteocytes. The high abundance of peroxisomes in these skeletal cell types is reflected by high levels of Pex11β gene expression. During culture, calvarial pre-osteoblasts differentiated into secretory osteoblasts accompanied by peroxisome proliferation and increased levels of peroxisomal genes and proteins. Since many peroxisomal genes contain a PPAR-responsive element, we analyzed the gene expression of PPARɑ/ß/ɣ in calvarial osteoblasts and MC3T3-E1 cells, revealing higher levels for PPARß than for PPARɑ and PPARɣ. Treatment with different PPAR agonists and antagonists not only changed the peroxisomal compartment and associated gene expression, but also induced complex alterations of the gene expression patterns of the other PPAR family members. Studies in M3CT3-E1 cells showed that the PPARß agonist GW0742 activated the PPRE-mediated luciferase expression and up-regulated peroxisomal gene transcription (Pex11, Pex13, Pex14, Acox1 and Cat, whereas the PPARß antagonist GSK0660 led to repression of the PPRE and a decrease of the corresponding mRNA levels. In the same way, treatment of calvarial osteoblasts with GW0742 increased in peroxisome number and

[Cermet cements for milk tooth fillings. Preliminary results].

Science.gov (United States)

Hickel, R; Petschelt, A; Voss, A

1989-06-01

106 Ketac-Silver fillings in deciduous molars were reevaluated after 1 to 3.3 years, i.e. 25 month on the average. About 90% of 50 occlusal fillings and about 84% of 56 multisurface restorations were unchanged. Without claiming statistical evidence for their conclusiveness, we consider these results as an indication that cermet cements are a useful alternative to amalgam fillings in deciduous teeth, particularly since the life of these fillings is limited to the time until the milk tooth is physiologically lost.

The influence of point defects on the entropy profiles of Lithium Ion Battery cathodes: a lattice-gas Monte Carlo study

International Nuclear Information System (INIS)

Mercer, Michael P.; Finnigan, Sophie; Kramer, Denis; Richards, Daniel; Hoster, Harry E.

2017-01-01

In-situ diagnostic tools have become established to as a means to understanding the aging processes that occur during charge/discharge cycles in Li-ion batteries (LIBs). One electrochemical thermodynamic technique that can be applied to this problem is known as entropy profiling. Entropy profiles are obtained by monitoring the variation in the open circuit potential as a function of temperature. The peaks in these profiles are related to phase transitions, such as order/disorder transitions, in the lattice. In battery aging studies of cathode materials, the peaks become suppressed but the mechanism by which this occurs is currently poorly understood. One suggested mechanism is the formation of point defects. Intentional modifications of LIB electrodes may also lead to the introduction of point defects. To gain quantitative understanding of the entropy profile changes that could be caused by point defects, we have performed Monte Carlo simulations on lattices of variable defect content. As a model cathode, we have chosen manganese spinel, which has a well-described order-disorder transition when it is half filled with Li. We assume, in the case of trivalent defect substitution (M = Cr,Co) that each defect M permanently pins one Li atom. This assumption is supported by Density Functional Theory (DFT) calculations. Assuming that the distribution of the pinned Li sites is completely random, we observe the same trend in the change in partial molar entropy with defect content as observed in experiment: the peak amplitudes become increasing suppressed as the defect fraction is increased. We also examine changes in the configurational entropy itself, rather than the entropy change, as a function of the defect fraction and analyse these results with respect to the ones expected for an ideal solid solution. We discuss the implications of the quantitative differences between some of the results obtained from the model and the experimentally observed ones.

Gas-Filled Capillary Model

International Nuclear Information System (INIS)

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

2006-01-01

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

Facts about Birth Defects

Science.gov (United States)

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

Grain boundary defects initiation at the outer surface of dissimilar welds: corrosion mechanism studies

International Nuclear Information System (INIS)

De Bouvier, O.; Yrieix, B.

1995-11-01

Dissimilar welds located on the primary coolant system of the French PWR I plants exhibit grain boundary defects in the true austenitic zones of the first buttering layer. If grain boundaries reach the interface, they can extend to the martensitic band. Those defects are filled with compact oxides. In addition, the ferritic base metal presents some pits along the interface. Nowadays, three mechanisms are proposed to explain the initiation of those defects: stress corrosion cracking, intergranular corrosion and high temperature intergranular oxidation. This paper is dealing with the study of the mechanisms involved in the corrosion phenomenon. Intergranular corrosion tests performed on different materials show that only the first buttering layer, even with some δ ferrite, is sensitized. The results of stress corrosion cracking tests in water solutions show that intergranular cracking is possible on a bulk material representative of the first buttering layer. It is unlikely on actual dissimilar welds where the ferritic base metal protects the first austenitic layer by galvanic coupling. Therefore, the stress corrosion cracking assumption cannot explain the initiation of the defects in aqueous environment. The results of the investigations and of the corrosion studies led to the conclusion that the atmosphere could be the only possible aggressive environment. This conclusion is based on natural atmospheric exposure and accelerated corrosion tests carried out with SO 2 additions in controlled atmosphere. They both induce a severe intergranular corrosion on true sensitized austenitic materials. This corrosion studies cannot conclude definitively on the causes of the defect initiation on field, but they show that the atmospheric corrosion could produce intergranular attacks in the pure austenitic zones of the first buttering layer of the dissimilar welds and that this corrosion is stress assisted. (author). 1 ref., 6 figs., 4 tabs

Radiographic bone fill following debridement of a periodontal abscess. A case report.

Science.gov (United States)

Khocht, A; Faldu, M G

1998-01-01

A periodontal abscess often develops in association with deepened periodontal pockets. Traditional management is by establishing drainage and prescribing antibiotics. This is usually followed by surgical pocket reduction. This case report discusses the remarkable healing of a periodontal abscess by establishing drainage alone without resorting to surgical pocket reduction. A 42-year-old white male presented with swollen gingivae associated with the mesiolingual of tooth #23. Increased probing depth and suppuration were evident. Radiographic bone loss on mesial #23 was present. A diagnosis of periodontal abscess was established. The abscess was drained through the orifice of the pocket. The patient failed to return for follow-up as instructed. A year later, the patient came back. Clinical evaluation showed healthy gingival tissues with probing depth of 3 mm on the mesiolingual of tooth #23. Radiographic evaluation showed bone fill of the osseous defect on the mesial of #23. The results of this case suggest that sufficient time should be allowed for healing prior to surgical pocket reduction.

Irradiation of defected SAP clad UO2 fuel in the X-7 organic loop

International Nuclear Information System (INIS)

Robertson, R.F.S.; Cracknell, A.G.; MacDonald, R.D.

1961-10-01

This report describes an experiment designed to test the behaviour under irradiation of a UO 2 fuel specimen clad in a defected SAP sheath and cooled by recirculating organic liquid. The specimen containing the defect was irradiated in the X-7 loop in the NRX reactor from the 25th of November until the 13th of December 1960. Up to the 13th of December the behaviour was analogous to that seen with defected UO 2 specimens clad in zircaloy which were irradiated in water loops. Reactor power transients resulted in peaking of gamma ray activities in the loop, but on steady operation these activities tended to fall to a steady state level, Over this period the pressure drop across the fuel increased by a factor of two, the increases occurring after reactor shut downs and start ups. On 13th December the pressure drop increased rapidly, after a reactor shut down and start up, to over five times its original value and the activities in the loop rose to a high level. The specimen was removed and examination showed that the sheath was very badly split and that the volume between the fuel and the sheath was filled with a hard black organic substance. This report gives full details of the irradiation and of the post -irradiation examination. Correlation of the observed phenomenon is attempted and a preliminary assessment of the problems which would be associated with defect fuel in an organic reactor is given. (author)

Preparation and Characterization of Injectable Brushite Filled-Poly (Methyl Methacrylate Bone Cement

Directory of Open Access Journals (Sweden)

Lucas C. Rodriguez

2014-09-01

Full Text Available Powder-liquid poly (methyl methacrylate (PMMA bone cements are widely utilized for augmentation of bone fractures and fixation of orthopedic implants. These cements typically have an abundance of beneficial qualities, however their lack of bioactivity allows for continued development. To enhance osseointegration and bioactivity, calcium phosphate cements prepared with hydroxyapatite, brushite or tricalcium phosphates have been introduced with rather unsuccessful results due to increased cement viscosity, poor handling and reduced mechanical performance. This has limited the use of such cements in applications requiring delivery through small cannulas and in load bearing. The goal of this study is to design an alternative cement system that can better accommodate calcium-phosphate additives while preserving cement rheological properties and performance. In the present work, a number of brushite-filled two-solution bone cements were prepared and characterized by studying their complex viscosity-versus-test frequency, extrusion stress, clumping tendency during injection through a syringe, extent of fill of a machined void in cortical bone analog specimens, and compressive strength. The addition of brushite into the two-solution cement formulations investigated did not affect the pseudoplastic behavior and handling properties of the materials as demonstrated by rheological experiments. Extrusion stress was observed to vary with brushite concentration with values lower or in the range of control PMMA-based cements. The materials were observed to completely fill pre-formed voids in bone analog specimens. Cement compressive strength was observed to decrease with increasing concentration of fillers; however, the materials exhibited high enough strength for consideration in load bearing applications. The results indicated that partially substituting the PMMA phase of the two-solution cement with brushite at a 40% by mass concentration provided the best

Initial settlements of rock fills on soft clay

OpenAIRE

Pedersen, Truls Martens

2012-01-01

Rock fills that hit the seabed will remold the underlying material. If this material is a clay with sufficiently low shear strength, it will adopt rheological properties, causing flow through the rock fill, and contributing to the initial settlements of the rock fill in addition to conventional consolidation theory. The settlements of the rocks depend upon the height of the rock fill and how the rocks have been laid out. This is due to the viscosity of the clay, and the fact that clay is thix...

To Fill or Not to Fill: Sensitivity Analysis of the Influence of Resolution and Hole Filling on Point Cloud Surface Modeling and Individual Rockfall Event Detection

Directory of Open Access Journals (Sweden)

Michael J. Olsen

2015-09-01

Full Text Available Monitoring unstable slopes with terrestrial laser scanning (TLS has been proven effective. However, end users still struggle immensely with the efficient processing, analysis, and interpretation of the massive and complex TLS datasets. Two recent advances described in this paper now improve the ability to work with TLS data acquired on steep slopes. The first is the improved processing of TLS data to model complex topography and fill holes. This processing step results in a continuous topographic surface model that seamlessly characterizes the rock and soil surface. The second is an advance in the automated interpretation of the surface model in such a way that a magnitude and frequency relationship of rockfall events can be quantified, which can be used to assess maintenance strategies and forecast costs. The approach is applied to unstable highway slopes in the state of Alaska, U.S.A. to evaluate its effectiveness. Further, the influence of the selected model resolution and degree of hole filling on the derived slope metrics were analyzed. In general, model resolution plays a pivotal role in the ability to detect smaller rockfall events when developing magnitude-frequency relationships. The total volume estimates are also influenced by model resolution, but were comparatively less sensitive. In contrast, hole filling had a noticeable effect on magnitude-frequency relationships but to a lesser extent than modeling resolution. However, hole filling yielded a modest increase in overall volumetric quantity estimates. Optimal analysis results occur when appropriately balancing high modeling resolution with an appropriate level of hole filling.

Defect production in ceramics

Energy Technology Data Exchange (ETDEWEB)

Zinkle, S.J. [Oak Ridge National Lab., TN (United States); Kinoshita, C. [Kyushu Univ. (Japan)

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.

Defects in dilute nitrides

International Nuclear Information System (INIS)

Chen, W.M.; Buyanova, I.A.; Tu, C.W.; Yonezu, H.

2005-01-01

We provide a brief review our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in dilute nitrides, i.e. Ga(In)NAs and Ga(Al,In)NP. Defect complexes involving intrinsic defects such as As Ga antisites and Ga i self interstitials were positively identified.Effects of growth conditions, chemical compositions and post-growth treatments on formation of the defects are closely examined. These grown-in defects are shown to play an important role in non-radiative carrier recombination and thus in degrading optical quality of the alloys, harmful to performance of potential optoelectronic and photonic devices based on these dilute nitrides. (author)

21 CFR 872.3820 - Root canal filling resin.

Science.gov (United States)

2010-04-01

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

The Behaviour of Bifilm Defects in Cast Al-7Si-Mg Alloy.

Science.gov (United States)

El-Sayed, Mahmoud Ahmed

2016-01-01

Double oxide films (bifilms) are significant defects in the casting of light alloys, and have been shown to decrease tensile and fatigue properties, and also to increase their scatter, making casting properties unreproducible and unreliable. A bifilm consists of doubled-over oxide films containing a gas-filled crevice and is formed due to surface turbulence of the liquid metal during handling and/or pouring. Previous studies has shown that the nature of oxide film defects may change with time, as the atmosphere inside the bifilm could be consumed by reaction with the surrounding melt, which may enhance the mechanical properties of Al alloy castings. As a proxy for a bifilm, an air bubble was trapped within an Al-7wt.%Si-0.3wt.%Mg (2L99) alloy melt, subjected to stirring. The effect of different parameters such as the holding time, stirring velocity and melt temperature on the change in gas composition of the bubble was investigated, using a design of experiments (DoE) approach. Also, the solid species inside the bubbles solidified in the melt were examined using SEM. The results suggested that both oxygen and nitrogen inside the bifilm would be consumed by reaction with the surrounding melt producing MgAl2O4 and AlN, respectively. Also, hydrogen was suggested to consistently diffuse into the defect. The reaction rates and the rate of H diffusion were shown to increase upon increasing the holding time and temperature, and stirring velocity. Such significant effect of the process parameters studied on the gaseous content of the bubble suggesting that a careful control of such parameters might lead to the deactivation of bifilm defects, or at least elimination of their deteriorous effect in light alloy castings.

7 CFR 58.730 - Filling containers.

Science.gov (United States)

2010-01-01

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

Modeling and Fault Simulation of Propellant Filling System

International Nuclear Information System (INIS)

Jiang Yunchun; Liu Weidong; Hou Xiaobo

2012-01-01

Propellant filling system is one of the key ground plants in launching site of rocket that use liquid propellant. There is an urgent demand for ensuring and improving its reliability and safety, and there is no doubt that Failure Mode Effect Analysis (FMEA) is a good approach to meet it. Driven by the request to get more fault information for FMEA, and because of the high expense of propellant filling, in this paper, the working process of the propellant filling system in fault condition was studied by simulating based on AMESim. Firstly, based on analyzing its structure and function, the filling system was modular decomposed, and the mathematic models of every module were given, based on which the whole filling system was modeled in AMESim. Secondly, a general method of fault injecting into dynamic system was proposed, and as an example, two typical faults - leakage and blockage - were injected into the model of filling system, based on which one can get two fault models in AMESim. After that, fault simulation was processed and the dynamic characteristics of several key parameters were analyzed under fault conditions. The results show that the model can simulate effectively the two faults, and can be used to provide guidance for the filling system maintain and amelioration.

Induction of spontaneous hyaline cartilage regeneration using a double-network gel: efficacy of a novel therapeutic strategy for an articular cartilage defect.

Science.gov (United States)

Kitamura, Nobuto; Yasuda, Kazunori; Ogawa, Munehiro; Arakaki, Kazunobu; Kai, Shuken; Onodera, Shin; Kurokawa, Takayuki; Gong, Jian Ping

2011-06-01

A double-network (DN) gel, which was composed of poly-(2-acrylamido-2-methylpropanesulfonic acid) and poly-(N,N'-dimetyl acrylamide) (PAMPS/PDMAAm), has the potential to induce chondrogenesis both in vitro and in vivo. To establish the efficacy of a therapeutic strategy for an articular cartilage defect using a DN gel. Controlled laboratory study. A 4.3-mm-diameter osteochondral defect was created in rabbit trochlea. A DN gel plug was implanted into the defect of the right knee so that a defect 2 mm in depth remained after surgery. An untreated defect of the left knee provided control data. The osteochondral defects created were examined by histological and immunohistochemical evaluations, surface assessment using confocal laser scanning microscopy, and real-time polymerase chain reaction (PCR) analysis at 4 and 12 weeks. Samples were quantitatively evaluated with 2 scoring systems reported by Wayne et al and O'Driscoll et al. The DN gel-implanted defect was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type 2 collagen. Quantitative evaluation using the grading scales revealed a significantly higher score in the DN gel-implanted defects compared with the untreated control at each period (P cartilage at 12 weeks (P = .0106), while there was no statistical difference between the DN gel-implanted and normal knees. This study using the mature rabbit femoral trochlea osteochondral defect model demonstrated that DN gel implantation is an effective treatment to induce cartilage regeneration in vivo without any cultured cells or mammalian-derived scaffolds. This study has prompted us to develop a potential innovative strategy to repair cartilage lesions in the field of joint surgery.

33 CFR 183.564 - Fuel tank fill system.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel tank fill system. 183.564...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.564 Fuel tank fill system. (a) Each fuel fill opening must be located so that a gasoline overflow of up to five...

Better building of valley fills

Energy Technology Data Exchange (ETDEWEB)

Chironis, N.P.

1980-03-01

Current US regulations for building valley fills or head of hollow fills to hold excess spoil resulting from contour mining are meeting with considerable opposition, particularly from operators in steep-slope areas. An alternative method has been submitted to the Office of Surface Mining by Virgina. Known as the zoned concept method, it has already been used successfully in building water-holding dams and coal refuse embankments on sloping terrain. The ways in which drainage and seepage are managed are described.

Radio resource management using geometric water-filling

CERN Document Server

He, Peter; Zhou, Sheng; Niu, Zhisheng

2014-01-01

This brief introduces the fundamental theory and development of managing radio resources using a water-filling algorithm that can optimize system performance in wireless communication. Geometric Water-Filling (GWF) is a crucial underlying tool in emerging communication systems such as multiple input multiple output systems, cognitive radio systems, and green communication systems. Early chapters introduce emerging wireless technologies and provide a detailed analysis of water-filling. The brief investigates single user and multi-user issues of radio resource management, allocation of resources

One-dimensional Gromov minimal filling problem

International Nuclear Information System (INIS)

Ivanov, Alexandr O; Tuzhilin, Alexey A

2012-01-01

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

Point defects and defect clusters examined on the basis of some fundamental experiments

International Nuclear Information System (INIS)

Zuppiroli, L.

1975-01-01

On progressing from the centre of the defect to the surface the theoretical approach to a point defect passes from electronic theories to elastic theory. Experiments by which the point defect can be observed fall into two categories. Those which detect long-range effects: measurement of dimensional variations in the sample; measurement of the mean crystal parameter variation; elastic X-ray scattering near the nodes of the reciprocal lattice (Huang scattering). Those which detect more local effects: low-temperature resistivity measurement; positron capture and annihilation; local scattering far from the reciprocal lattice nodes. Experiments involving both short and long-range effects can always be found. This is the case for example with the dechanneling of α particles by defects. Certain of the experimental methods quoted above apply also to the study of point defect clusters. These methods are illustrated by some of their most striking results which over the last twenty years have refined our knowledge of point defects and defect clusters: length and crystal parameter measurements; diffuse X-ray scattering; low-temperature resistivity measurements; ion emission microscopy; electron microscopy; elastoresistivity [fr

Birth Defects (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Birth Defects KidsHealth / For Parents / Birth Defects What's in ... Prevented? Print en español Anomalías congénitas What Are Birth Defects? While still in the womb, some babies ...

Transplantation of dedifferentiated fat cell-derived micromass pellets contributed to cartilage repair in the rat osteochondral defect model.

Science.gov (United States)

Shimizu, Manabu; Matsumoto, Taro; Kikuta, Shinsuke; Ohtaki, Munenori; Kano, Koichiro; Taniguchi, Hiroaki; Saito, Shu; Nagaoka, Masahiro; Tokuhashi, Yasuaki

2018-03-20

Mature adipocyte-derived dedifferentiated fat (DFAT) cells possesses the ability to proliferate effectively and the potential to differentiate into multiple linages of mesenchymal tissue; similar to adipose-derived stem cells (ASCs). The purpose of this study is to examine the effects of DFAT cell transplantation on cartilage repair in a rat model of osteochondral defects. Full-thickness osteochondral defects were created in the knees of Sprague-Dawley rats bilaterally. Cartilage-like micromass pellets were prepared from green fluorescent protein (GFP)-labeled rat DFAT cells and subsequently transplanted into the affected right knee of these rats. Defects in the left knee were used as a control. Macroscopic and microscopic changes of treated and control defects were evaluated up to 12 weeks post-treatment with DFAT cells. To observe the transplanted cells, sectioned femurs were immunostained for GFP and type II collagen. DFAT cells formed micromass pellets expressing characteristics of immature cartilage in vitro. In the DFAT cell-transplanted limbs, the defects were completely filled with white micromass pellets as early as 2 weeks post-treatment. These limbs became smooth at 4 weeks. Conversely, the defects in the control limbs were still not repaired by 4 weeks. Macroscopic ICRS scores at 2 and 4 weeks were significantly higher in the DFAT cells-transplanted limbs compared to those of the control limbs. The modified O'Driscol histological scores for the DFAT cell-transplanted limbs were significantly higher than those of the control limbs at corresponding time points. GFP-positive DAFT cells were detected in the transplanted area at 2 weeks but hardly visible at 12 weeks post-operation. Transplantation of DFAT cell-derived micromass pellets contribute to cartilage repair in a rat osteochondral defect model. DFAT cell transplantation may be a viable therapeutic strategy for the repair of osteochondral injuries. Copyright © 2018 The Authors. Published by

Defect of the Eyelids.

Science.gov (United States)

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

2017-08-01

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

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

African Journals Online (AJOL)

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

Influence of dental filling material type on the concentration of interleukin 9 in the samples of gingival crevicular fluid

Directory of Open Access Journals (Sweden)

Stefanović Vladimir

2016-01-01

Full Text Available Background/Aim. Several cytokines and lymphokines (IL1β, ENA78, IL6, TNFα, IL8 and S100A8 are expressed during dental pulp inflammation. Analysis of gingival crevicu-lar fluid (GCF offers a non-invasive means of studying gen-eral host response in oral cavity. Although GCF levels of various mediators could reflect the state of inflammation both in dental pulp and gingiva adjacent to a tooth, GCF samples of those without significant gingivitis could be inter-preted as reflection of pulpal process. The aim of this study was to investigate IL9 GCF values in patients with dental car-ies and to assess possible influence of various dental fillings materials on local IL9 production. Methods. The study group included 90 patients, aged 18–70, with inclusion and exclusion criteria in the prospective clinical study. Of the 6 types of material used for the restoration of prepared cavities, 3 were intended for temporary and 3 for definitive restora-tion. According to dental fillings weight, all the participants were divided into 3 groups: those with fillings lighter than 0.50 g, those with 0.50–1.00 g, and those with fillings heavier than 1.00 g. Samples were taken from gingival sulcus using the filter paper technique. Clinical parameters were deter-mined by bleeding index, plaque index (Silness-Lou, 0–3, gingival index (0–3, and gingival sulcus depth. Cytokine con-centrations were assessed using commercially available cy-tomix. Results. According to the weight of dental fillings, there was a clear decreament trend of IL9 values meaning that dental defects greater than 1.00 g of dental filling were associated with lower GCF IL9 concentration. The IL9 val-ues correlated with the degree of gingival index and depth of gingival sulcus, being higher with more advanced gingivitis and more pronounced anatomical changes in the tooth edge. Different filling materials exerted various local IL9 responses. Zink polycarbonate cement and amalgam fillings induced

Space-Time Water-Filling for Composite MIMO Fading Channels

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available We analyze the ergodic capacity and channel outage probability for a composite MIMO channel model, which includes both fast fading and shadowing effects. The ergodic capacity and exact channel outage probability with space-time water-filling can be evaluated through numerical integrations, which can be further simplified by using approximated empirical eigenvalue and maximal eigenvalue distribution of MIMO fading channels. We also compare the performance of space-time water-filling with spatial water-filling. For MIMO channels with small shadowing effects, spatial water-filling performs very close to space-time water-filling in terms of ergodic capacity. For MIMO channels with large shadowing effects, however, space-time water-filling achieves significantly higher capacity per antenna than spatial water-filling at low to moderate SNR regimes, but with a much higher channel outage probability. We show that the analytical capacity and outage probability results agree very well with those obtained from Monte Carlo simulations.

Spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect created in the femoral condyle using a novel double-network hydrogel.

Science.gov (United States)

Yokota, Masashi; Yasuda, Kazunori; Kitamura, Nobuto; Arakaki, Kazunobu; Onodera, Shin; Kurokawa, Takayuki; Gong, Jian-Ping

2011-02-22

Functional repair of articular osteochondral defects remains a major challenge not only in the field of knee surgery but also in tissue regeneration medicine. The purpose is to clarify whether the spontaneous hyaline cartilage regeneration can be induced in a large osteochondral defect created in the femoral condyle by means of implanting a novel double-network (DN) gel at the bottom of the defect. Twenty-five mature rabbits were used in this study. In the bilateral knees of each animal, we created an osteochondral defect having a diameter of 2.4-mm in the medial condyle. Then, in 21 rabbits, we implanted a DN gel plug into a right knee defect so that a vacant space of 1.5-mm depth (in Group I), 2.5-mm depth (in Group II), or 3.5-mm depth (in Group III) was left. In the left knee, we did not apply any treatment to the defect to obtain the control data. All the rabbits were sacrificed at 4 weeks, and the gross and histological evaluations were performed. The remaining 4 rabbits underwent the same treatment as used in Group II, and real-time PCR analysis was performed at 4 weeks. The defect in Group II was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen. The Wayne's gross appearance and histology scores showed that Group II was significantly greater than Group I, III, and Control (p hyaline cartilage regeneration can be induced in vivo in an osteochondral defect created in the femoral condyle by means of implanting the DN gel plug at the bottom of the defect so that an approximately 2-mm deep vacant space was intentionally left in the defect. This fact has prompted us to propose an innovative strategy without cell culture to repair osteochondral lesions in the femoral condyle.

Formation of topological defects

International Nuclear Information System (INIS)

Vachaspati, T.

1991-01-01

We consider the formation of point and line topological defects (monopoles and strings) from a general point of view by allowing the probability of formation of a defect to vary. To investigate the statistical properties of the defects at formation we give qualitative arguments that are independent of any particular model in which such defects occur. These arguments are substantiated by numerical results in the case of strings and for monopoles in two dimensions. We find that the network of strings at formation undergoes a transition at a certain critical density below which there are no infinite strings and the closed-string (loop) distribution is exponentially suppressed at large lengths. The results are contrasted with the results of statistical arguments applied to a box of strings in dynamical equilibrium. We argue that if point defects were to form with smaller probability, the distance between monopoles and antimonopoles would decrease while the monopole-to-monopole distance would increase. We find that monopoles are always paired with antimonopoles but the pairing becomes clean only when the number density of defects is small. A similar reasoning would also apply to other defects

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

Science.gov (United States)

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...

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

Science.gov (United States)

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...

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

Science.gov (United States)

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...

Gas filled detectors

International Nuclear Information System (INIS)

Stephan, C.

1993-01-01

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

Distribution of defects in wind turbine blades and reliability assessment of blades containing defects

DEFF Research Database (Denmark)

Stensgaard Toft, Henrik; Branner, Kim; Berring, Peter

2009-01-01

on the assumption that one error in the production process tends to trigger several defects. For both models additional information about number, type and size of the defects is included as stochastic variables. The probability of failure for a wind turbine blade will not only depend on variations in the material......In the present paper two stochastic models for the distribution of defects in wind turbine blades are proposed. The first model assumes that the individual defects are completely randomly distributed in the blade. The second model assumes that the defects occur in clusters of different size based...... properties and the load but also on potential defects in the blades. As a numerical example the probability of failure is calculated for the main spar both with and without defects in terms of delaminations. The delaminations increase the probability of failure compared to a perfect blade, but by applying...

The combined use of scanning vibrating electrode technique and micro-potentiometry to assess the self-repair processes in defects on 'smart' coatings applied to galvanized steel

International Nuclear Information System (INIS)

Taryba, M.; Lamaka, S.V.; Snihirova, D.; Ferreira, M.G.S.; Montemor, M.F.; Wijting, W.K.; Toews, S.; Grundmeier, G.

2011-01-01

Research highlights: → Weldable primers were modified with submicron containers loaded with corrosion inhibitors. → SVET and micro-potentiometry were used to study the corrosion inhibition ability. → Submicron containers do not damage the barrier properties of model primers. → Artificial defects of 50μm x 50 μm in a coating can be easily analyzed by SVET and SIET. → Inhibiting dissolution of sacrificial Zn may result in detrimental dissolution of Fe. - Abstract: Model weldable primer coatings for galvanized steel were modified with submicron containers loaded with corrosion inhibitors. This procedure aims at introducing a new functionality in the thin coatings self-repair ability. The assessment of this property demands new protocols and new approaches, combining conventional electrochemical methods with electrochemical and analytical techniques of micrometer spatial resolution. Thus, in this work model defects were created in the coatings by using a focused ion beam (FIB). The coated samples, containing the model defects, were immersed in a NaCl 0.05 M solution and the corrosion inhibition ability was studied using the scanning vibrating electrode technique (SVET) and the scanning ion-selective electrode technique (SIET). SVET-SIET measurements were performed quasi-simultaneously. Qualitative chemical analysis was performed by SEM combined with EDS. Complementary studies were carried out by electrochemical impedance spectroscopy (EIS) to assess the effect of the containers filled with corrosion inhibitors on the barrier properties of the coatings. The electrochemical results highlight the importance of the combined use of integral and localized electrochemical techniques to extract information for a better understanding of the corrosion processes and corresponding repair of active microscopic defects formed on thin coatings containing inhibitor filled containers.

The water-filled versus air-filled status of vessels cut open in air: the 'Scholander assumption' revisited

Science.gov (United States)

M.T. Tyree; H. Cochard; P. Cruziat

2003-01-01

When petioles of transpiring leaves are cut in the air, according to the 'Scholander assumption', the vessels cut open should fill with air as the water is drained away by continued transpiration, The distribution of air-filled vessels versus distance from the cut surface should match the distribution of lengths of 'open vessels', i.e. vessels cut...

Entanglement entropy in integrable field theories with line defects II. Non-topological defect

Science.gov (United States)

Jiang, Yunfeng

2017-08-01

This is the second part of two papers where we study the effect of integrable line defects on bipartite entanglement entropy in integrable field theories. In this paper, we consider non-topological line defects in Ising field theory. We derive an infinite series expression for the entanglement entropy and show that both the UV and IR limits of the bulk entanglement entropy are modified by the line defect. In the UV limit, we give an infinite series expression for the coefficient in front of the logarithmic divergence and the exact defect g-function. By tuning the defect to be purely transmissive and reflective, we recover correctly the entanglement entropy of the bulk and with integrable boundary respectively.

Geomechanical investigations for the designing of cemented filling

Energy Technology Data Exchange (ETDEWEB)

Berry, P.

1980-05-15

Laboratory and in situ investigations have led to the identification of the main geomechanical parameters that condition the stability of the cemented fill in the Gavorrano pyrite mine (Tuscany, Italy); such parameters were used for working out a satisfactory mining method. The pyrite is mined with the descending horizontal slice method with integral cemented filling which is obtained by throwing a mixture of limestone aggregates and cement into the mined voids. The laboratory geomechanical investigations carried out on fill samples have pointed out that the physical and mechanical characteristics are highly variable and this is essentially due to the fact that the fill is cast into place by compressed air. In particular, it was pointed out that the strength depends upon the cement content and upon the porosity according to a power law. The in situ measurements of the convergence between the roof and the floor, and the load measurements pointed out the considerable importance of the horizontal and vertical joints that cross the fill mass and that are inevitably brought about by a discontinuity of the fill. The results of the study made it possible to adopt an acceptable geomechanical behaviour model of the fill. On the basis of this model the mining pattern was deeply modified, the width and the height of the slices were considerably enlarged and thus the output was improved.

Improving the support characteristics of hydraulic fill

Energy Technology Data Exchange (ETDEWEB)

Corson, D. R.; Dorman, K. R.; Sprute, R. H.

1980-05-15

Extensive laboratory and field testing has defined the physical properties of hydraulic fill. Effect of void ratio on percolation rate has been quantified, and tests were developed to estimate waterflow through fill material in a given state underground. Beneficial effect on fill's support capability through addition of cement alone or in conjunction with vibratory compaction has been investigated. Two separate field studies in operating cut-and-fill mines measured vein-wall deformation and loads imposed on backfilled stopes. Technology has been developed that will effectively and efficiently dewater and densify ultra-fine-grained slurries typical of metal mine hydraulic backfill. At least two operators are using this electrokinetic technique to dewater slimes collected in underground sumps or impoundments. This technique opens up the possibility of using the total unclassified tailings product as a hydraulic backfill. Theoretical enhancement of ground support and rock-burst control through improved support capability will be tested in a full-scale mine stope installation. Both a horizontal layer and a vertical column of high modulus fill will be placed in an attempt to reduce stope wall closure, support more ground pressure, and lessen rock-burst occurrence.

High-etch-rate bottom-antireflective coating and gap-fill materials using dextrin derivatives in via first dual-Damascene lithography process

Science.gov (United States)

Takei, Satoshi; Sakaida, Yasushi; Shinjo, Tetsuya; Hashimoto, Keisuke; Nakajima, Yasuyuki

2008-03-01

The present paper describes a novel class of bottom antireflective coating (BARC) and gap fill materials using dextrin derivatives. The general trend of interconnect fabrication for such a high performance LSI is to apply cupper (Cu)/ low-dielectric-constant (low-k) interconnect to reduce RC delay. A via-first dual damascene process is one of the most promising processes to fabricate Cu/ low-k interconnect due to its wide miss-alignment margin. The sacrificial materials containing dextrin derivatives under resist for lithography were developed in via-first dual damascene process. The dextrin derivatives in this study was obtained by the esterification of the hydroxyl groups of dextrin resulting in improved solubility in the resist solvents such as propylene glycol monomethylether, propylene glycol monomethylether acetate, and ethyl lactate due to avoid the issue of defects that were caused by incompatability. The etch rate of our developed BARC and gap fill materials using dextrin derivatives was more than two times faster than one of the ArF resists evaluated in a CF4 gas condition using reactive ion etching. The improved etch performance was also verified by comparison with poly(hydroxystyrene), acrylate-type materials and latest low-k materials as a reference. In addition to superior etch performance, these materials showed good resist profiles and via filling performance without voids in via holes.

Natural defects and defects created by ionic implantation in zinc tellurium

International Nuclear Information System (INIS)

Roche, J.P.; Dupuy, M.; Pfister, J.C.

1977-01-01

Various defects have been studied in ZnTe crystals by transmission electron microscope and by scanning electron microscope in cathodo-luminescence mode: grain boundaries, sub-grain boundaries, twins. Ionic implants of boron (100 keV - 2x10 14 and 10 15 ions cm -2 ) were made on these crystals followed by isochrone annealing (30 minutes) of zinc under partial pressure at 550, 650 and 750 0 C. The nature of the defects was determined by transmission electron microscope: these are interstitial loops (b=1/3 ) the size of which varies between 20 A (non-annealed sample) and 180A (annealed at 750 0 C). The transmission electron microscope was also used to make concentration profiles of defects depending on depth. It is found that for the same implant (2x10 14 ions.cm -2 ), the defect peak moves towards the exterior of the crystal as the annealing temperature rises (400 - 1000 and 7000 A for the three annealings). These results are explained from a model which allows for the coalescence of defects and considers the surface of the sample as being the principal source of vacancies. During the annealings, the migration of vacancies brings about the gradual annihilation of the implant defects. The adjustment of certain calculation parameters on the computer result in giving 2 eV as energy value for the formation of vacancies [fr

Chimeric superficial temporal artery based skin and temporal fascia flap plus temporalis muscle flap - An alternative to free flap for suprastructure maxillectomy with external skin defect

Directory of Open Access Journals (Sweden)

Dushyant Jaiswal

2011-01-01

Full Text Available Flaps from temporal region have been used for mid face, orbital and peri-orbital reconstruction. The knowledge of the vascular anatomy of the region helps to dissect and harvest the muscle/fascia/skin/combined tissue flaps from that region depending upon the requirement. Suprastructure maxillectomy defects are usually covered with free flaps to fill the cavity. Here we report an innovative idea in which a patient with a supra structure maxillectomy with external skin defect was covered with chimeric flap based on the parietal and frontal branches of superficial temporal artery and the temporalis muscle flap based on deep temporal artery.

Effect of bulk-fill base material on fracture strength of root-filled teeth restored with laminate resin composite restorations.

Science.gov (United States)

Taha, N A; Maghaireh, G A; Ghannam, A S; Palamara, J E

2017-08-01

To evaluate the effect of using a bulk-fill flowable base material on fracture strength and fracture patterns of root-filled maxillary premolars with MOD preparations restored with laminate restorations. Fifty extracted maxillary premolars were selected for the study. Standardized MOD cavities with endodontic treatment were prepared for all teeth, except for intact control. The teeth were divided randomly into five groups (n=10); (Group 1) sound teeth, (Group 2) unrestored teeth; (Group 3) MOD cavities with Vitrebond base and resin-based composite (Ceram. X One Universal); (Group 4) MOD cavities with 2mm GIC base (Fuji IX GP) and resin-based composite (Ceram. X One Universal) open laminate, (Group 5) MOD cavities were restored with 4mm of bulk-fill flowable base material (SDR) and resin-based composite (Ceram. X One Universal). All teeth were thermocycled and subjected to a 45° ramped oblique load in a universal testing machine. Fracture load and fracture patterns were recorded. Data were analyzed using one-way ANOVA and Dunnett's T3 test. Restoration in general increased the fracture strength compared to unrestored teeth. The fracture strength of group 5 (bulk-fill) was significantly higher than the fracture strength of the GIC laminate groups and not significantly different from the intact teeth (355±112N, P=0.118). The type of failure was unfavorable for most of the groups, with the majority being mixed failures. The use of a bulk-fill flowable base material significantly increased the fracture strength of extracted root-filled teeth with MOD cavities; however it did not improve fracture patterns to more favorable ones. Investigating restorative techniques that may improve the longevity of root-filled premolar teeth restored with direct resin restorations. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

R. Edward. Thomas

2009-01-01

As a hardwood tree grows and develops, surface defects such as branch stubs and wounds are overgrown. Evidence of these defects remain on the log surface for decades and in many instances for the life of the tree. As the tree grows the defect is encapsulated or grown over by new wood. During this process the appearance of the defect in the tree's bark changes. The...

Optimization of foam-filled bitubal structures for crashworthiness criteria

International Nuclear Information System (INIS)

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

2012-01-01

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

Development of gap filling technique in HLW repository

International Nuclear Information System (INIS)

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

2016-01-01

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

Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

KAUST Repository

Fidiani, Elok; Da Costa, Pedro M. F. J.; Wolter, Anja U. B.; Maier, Diana; Buechner, Bernd; Hampel, Silke

2013-01-01

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

Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

KAUST Repository

Fidiani, Elok

2013-08-15

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

Automatic classification of blank substrate defects

Science.gov (United States)

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

Localized persistent spin currents in defect-free quasiperiodic rings with Aharonov–Casher effect

International Nuclear Information System (INIS)

Qiu, R.Z.; Chen, C.H.; Cheng, Y.H.; Hsueh, W.J.

2015-01-01

We propose strongly localized persistent spin current in one-dimensional defect-free quasiperiodic Thue–Morse rings with Aharonov–Casher effect. The results show that the characteristics of these localized persistent currents depend not only on the radius filling factor, but also on the strength of the spin–orbit interaction. The maximum persistent spin currents in systems always appear in the ring near the middle position of the system array whether or not the Thue–Morse rings array is symmetrical. The magnitude of the persistent currents is proportional to the sharpness of the resonance peak, which is dependent on the bandwidth of the allowed band in the band structure. The maximum persistent spin currents also increase exponentially as the generation order of the system increases. - Highlights: • Strongly localized persistent spin current in quasiperiodic AC rings is proposed. • Localized persistent spin currents are much larger than those produced by traditional mesoscopic rings. • Characteristics of the localized persistent currents depend on the radius filling factor and SOI strength. • The maximum persistent current increases exponentially with the system order. • The magnitude of the persistent currents is related to the sharpness of the resonance

Tension-filled Governance?

DEFF Research Database (Denmark)

Celik, Tim Holst

on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...

Holographic Chern-Simons defects

International Nuclear Information System (INIS)

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

2016-01-01

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.

Is a 5 mm rat calvarium defect really critical? Um defeito de 5 mm em calota craniana de rato é realmente critico?

Directory of Open Access Journals (Sweden)

Gabriela Granja Porto

2012-11-01

Full Text Available PURPOSE: To evaluate bone regeneration in critical defects in the rats' calvarium. METHODS: Eighteen rats Wistar were divided into three groups of six animals each according to the time of evaluation (15, 30 and 60 days. One calvarium defect of 5mm was made in the parietal bone of each animal under general anesthesia. After the time of evaluation, the animals were killed, when the bone was histological studied and classified according to the type of tissue found: fibrosis or bone. RESULTS: The results showed that in the group of 15 days, in five animals there was only fibrosis. In the group of 30 days, the process of regeneration was growing and in four animals was found bone, in three with partial filling and in the other one with complete filling of the defect. In the group of 60 days, out of the three animals with bone, two had a complete filling of the defect. CONCLUSIONS: There was no bone regeneration in critical defects in 15 days. There was regeneration in the most part of the animals in 30 and 60 days.OBJETIVO: Avaliar a regeneração óssea de defeitos críticos em calota craniana de ratos. MÉTODOS: Foram utilizados 18 ratos Wistar que foram distribuídos em três grupos de acordo com o tempo de avaliação (15, 30 e 60 dias. Na calota craniana desses animais foi realizado defeito de 5mm, após anestesia geral prévia. Após o tempo de avaliação, os animais foram submetidos à eutanásia e a calota foi enviada para estudo histológico, quando foi classificada de acordo o tecido encontrado: fibroso ou ósseo. RESULTADOS: Diante dos achados deste estudo, pode-se observar que para o grupo de 15 dias na maioria dos animais, n=5, foi encontrado apenas fibrose. Com o passar do tempo de avaliação, no grupo de 30 dias, o processo de reparo foi evoluindo e em quatro animais já foi encontrado osso, sendo em três com preenchimento parcial e em um completo. No grupo de 60 dias, o processo praticamente permaneceu o mesmo, onde em tr

Evaluation of healing potential of autogenous, macroscopic fat deposited or fat free, omental graft in experimental radius bone defect in rabbit: Radiological study

International Nuclear Information System (INIS)

Masouleh, M.N.; Haghdoost, I.S.; Heydari, G.A.C.; Raissi, A.; Mohitmafi, S.

2011-01-01

This study was designed for evaluation of the difference between the ability of greater omentum graft with or without macroscopic fat deposition in acceleration of bone healing process. Adult female New Zealand white rabbits (n=15) were randomly divided into three equal groups. In groups A and B, the drilled hole on the left radius was filled by the omentum without and with macroscopic fat deposition, respectively while drilled hole on the right radius left intact for consideration as control. In group C, the drilled hole on the left and right radius was filled by the omentum sample with and without macroscopic fat deposition, respectively. Experimental bone defects on the radiuses were secured by the pieces of greater omentum, with or without macroscopic fat deposition, which obtained as an autogenous graft from each rabbit in accompany with control samples. Standardized serial radiography for evaluation of bone healing was performed and the difference in bone healing process in three groups of study was determined. According to the obtained data, the radius bones which filled by omentum without macroscopic fat deposition showed faster healing process than the radius bones which filled by omentum with macroscopic fat deposition (P<0.05). (author)

Theoretical analysis of the influence of defect parameters on photovoltaic performances of composition graded InGaN solar cells

International Nuclear Information System (INIS)

Gorge, V.; Migan-Dubois, A.; Djebbour, Z.; Pantzas, K.; Gautier, S.; Moudakir, T.; Suresh, S.; Ougazzaden, A.

2013-01-01

Highlights: ► We have modeled a p–i–n InGaN-based solar cell with gradual bandgap layers. ► InGaN defects have been modeled by two band tails and one localized energy level. ► Energetic position and band tail widths have a low effect on device efficiency. ► The localized defect FWHM has a significant impact on performance. ► The efficiency drops radically when the defect density is higher than the P-doping. - Abstract: In this paper, we have used simulations to evaluate the impact of the distribution of electrically active defects on the photovoltaic performances of InGaN-based solar cell. The simulations were carried out using Silvaco's ATLAS software. We have modeled a P-GaN/Grad-InGaN/i-In 0.53 Ga 0.47 N/Grad-InGaN/N-ZnO where Grad-InGaN corresponds to an InGaN layer with a graded composition. This layer is inserted to eliminate the band discontinuities at the interface between InGaN and the GaN and ZnO layers. The defects were modeled through the introduction of band tails and a Gaussian distribution of defects in i-InGaN material. We have evaluated the influence of band tail widths as well as the parameters of the Gaussian distribution (i.e. defect density, mean position and standard deviation) on the short-circuit current, the open-circuit voltage and the fill-factor (efficiency) of the solar cell. These results have allowed us to identify key structural parameters useful for the optimization of InGaN solar cells, as well as to give realistic estimates of the performances of such cells.

Theoretical analysis of the influence of defect parameters on photovoltaic performances of composition graded InGaN solar cells

Energy Technology Data Exchange (ETDEWEB)

Gorge, V.; Migan-Dubois, A. [LGEP, UMR 8507, CNRS, SUPELEC, UPMC, Universite Paris-Sud 11, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex (France); Djebbour, Z., E-mail: zakaria.djebbour@uvsq.fr [LGEP, UMR 8507, CNRS, SUPELEC, UPMC, Universite Paris-Sud 11, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex (France); Department of Physics and Engineering Science, University of Versailles UVSQ, 45 Av. Des Etats Unis, 78035 Versailles (France); Pantzas, K. [Georgia Institute of Technology, GT-Lorraine, 2 rue Marconi, 57 070 Metz (France); UMI 2958 Georgia Tech, CNRS, 2 rue Marconi, 57 070 Metz (France); Gautier, S. [UMI 2958 Georgia Tech, CNRS, 2 rue Marconi, 57 070 Metz (France); LMOPS, UMR 7132, CNRS, University of Metz, Supelec, 2 rue E. Belin, 57 070 Metz (France); Moudakir, T.; Suresh, S. [UMI 2958 Georgia Tech, CNRS, 2 rue Marconi, 57 070 Metz (France); Ougazzaden, A. [Georgia Institute of Technology, GT-Lorraine, 2 rue Marconi, 57 070 Metz (France); UMI 2958 Georgia Tech, CNRS, 2 rue Marconi, 57 070 Metz (France)

2013-02-01

Highlights: Black-Right-Pointing-Pointer We have modeled a p-i-n InGaN-based solar cell with gradual bandgap layers. Black-Right-Pointing-Pointer InGaN defects have been modeled by two band tails and one localized energy level. Black-Right-Pointing-Pointer Energetic position and band tail widths have a low effect on device efficiency. Black-Right-Pointing-Pointer The localized defect FWHM has a significant impact on performance. Black-Right-Pointing-Pointer The efficiency drops radically when the defect density is higher than the P-doping. - Abstract: In this paper, we have used simulations to evaluate the impact of the distribution of electrically active defects on the photovoltaic performances of InGaN-based solar cell. The simulations were carried out using Silvaco's ATLAS software. We have modeled a P-GaN/Grad-InGaN/i-In{sub 0.53}Ga{sub 0.47}N/Grad-InGaN/N-ZnO where Grad-InGaN corresponds to an InGaN layer with a graded composition. This layer is inserted to eliminate the band discontinuities at the interface between InGaN and the GaN and ZnO layers. The defects were modeled through the introduction of band tails and a Gaussian distribution of defects in i-InGaN material. We have evaluated the influence of band tail widths as well as the parameters of the Gaussian distribution (i.e. defect density, mean position and standard deviation) on the short-circuit current, the open-circuit voltage and the fill-factor (efficiency) of the solar cell. These results have allowed us to identify key structural parameters useful for the optimization of InGaN solar cells, as well as to give realistic estimates of the performances of such cells.

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2011-01-01

This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level m...

Point defects in solids

International Nuclear Information System (INIS)

Anon.

1978-01-01

The principal properties of point defects are studied: thermodynamics, electronic structure, interactions with etended defects, production by irradiation. Some measuring methods are presented: atomic diffusion, spectroscopic methods, diffuse scattering of neutron and X rays, positron annihilation, molecular dynamics. Then points defects in various materials are investigated: ionic crystals, oxides, semiconductor materials, metals, intermetallic compounds, carbides, nitrides [fr

Management of extra-articular segmental defects in long bone using a titanium mesh cage as an adjunct to other methods of fixation.

Science.gov (United States)

Attias, N; Thabet, A M; Prabhakar, G; Dollahite, J A; Gehlert, R J; DeCoster, T A

2018-05-01

Aims This study reviews the use of a titanium mesh cage (TMC) as an adjunct to intramedullary nail or plate reconstruction of an extra-articular segmental long bone defect. Patients and Methods A total of 17 patients (aged 17 to 61 years) treated for a segmental long bone defect by nail or plate fixation and an adjunctive TMC were included. The bone defects treated were in the tibia (nine), femur (six), radius (one), and humerus (one). The mean length of the segmental bone defect was 8.4 cm (2.2 to 13); the mean length of the titanium mesh cage was 8.3 cm (2.6 to 13). The clinical and radiological records of the patients were analyzed retrospectively. Results The mean time to follow-up was 55 months (12 to 126). Overall, 16 (94%) of the patients achieved radiological filling of their bony defect and united to the native bone ends proximally and distally, resulting in a functioning limb. Complications included device failure in two patients (12%), infection in two (12%), and wound dehiscence in one (6%). Four patients (24%) required secondary surgery, four (24%) had a residual limb-length discrepancy, and one (6%) had a residual angular limb deformity. Conclusion A titanium mesh cage is a useful adjunct in the treatment of an extra-articular segmental defect in a long bone. Cite this article: Bone Joint J 2018;100-B:646-51.

Postnatal Deletion of Podoplanin in Lymphatic Endothelium Results in Blood Filling of the Lymphatic System and Impairs Dendritic Cell Migration to Lymph Nodes.

Science.gov (United States)

Bianchi, Roberta; Russo, Erica; Bachmann, Samia B; Proulx, Steven T; Sesartic, Marko; Smaadahl, Nora; Watson, Steve P; Buckley, Christopher D; Halin, Cornelia; Detmar, Michael

2017-01-01

The lymphatic vascular system exerts major physiological functions in the transport of interstitial fluid from peripheral tissues back to the blood circulation and in the trafficking of immune cells to lymph nodes. Previous studies in global constitutive knockout mice for the lymphatic transmembrane molecule podoplanin reported perinatal lethality and a complex phenotype with lung abnormalities, cardiac defects, lymphedema, blood-filled lymphatic vessels, and lack of lymph node organization, reflecting the importance of podoplanin expression not only by the lymphatic endothelium but also by a variety of nonendothelial cell types. Therefore, we aimed to dissect the specific role of podoplanin expressed by adult lymphatic vessels. We generated an inducible, lymphatic-specific podoplanin knockout mouse model (Pdpn ΔLEC ) and induced gene deletion postnatally. Pdpn ΔLEC mice were viable, and their lymphatic vessels appeared morphologically normal with unaltered fluid drainage function. Intriguingly, Pdpn ΔLEC mice had blood-filled lymph nodes and vessels, most frequently in the neck and axillary region, and displayed a blood-filled thoracic duct, suggestive of retrograde filling of blood from the blood circulation into the lymphatic system. Histological and fluorescence-activated cell sorter analyses revealed normal lymph node organization with the presence of erythrocytes within lymph node lymphatic vessels but not surrounding high endothelial venules. Moreover, fluorescein isothiocyanate painting experiments revealed reduced dendritic cell migration to lymph nodes in Pdpn ΔLEC mice. These results reveal an important role of podoplanin expressed by lymphatic vessels in preventing postnatal blood filling of the lymphatic vascular system and in contributing to efficient dendritic cell migration to the lymph nodes. © 2016 American Heart Association, Inc.

filled neutron detectors

Indian Academy of Sciences (India)

Boron trifluoride (BF3) proportional counters are used as detectors for thermal neutrons. They are characterized by high neutron sensitivity and good gamma discriminating properties. Most practical BF3 counters are filled with pure boron trifluoride gas enriched up to 96% 10B. But BF3 is not an ideal proportional counter ...

Defect detection using transient thermography

International Nuclear Information System (INIS)

Mohd Zaki Umar; Ibrahim Ahmad; Ab Razak Hamzah; Wan Saffiey Wan Abdullah

2008-08-01

An experimental research had been carried out to study the potential of transient thermography in detecting sub-surface defect of non-metal material. In this research, eight pieces of bakelite material were used as samples. Each samples had a sub-surface defect in the circular shape with different diameters and depths. Experiment was conducted using one-sided Pulsed Thermal technique. Heating of samples were done using 30 kWatt adjustable quartz lamp while infra red (IR) images of samples were recorded using THV 550 IR camera. These IR images were then analysed with ThermofitTMPro software to obtain the Maximum Absolute Differential Temperature Signal value, ΔΤ m ax and the time of its appearance, τ m ax (ΔΤ). Result showed that all defects were able to be detected even for the smallest and deepest defect (diameter = 5 mm and depth = 4 mm). However the highest value of Differential Temperature Signal (ΔΤ m ax), were obtained at defect with the largest diameter, 20 mm and at the shallowest depth, 1 mm. As a conclusion, the sensitivity of the pulsed thermography technique to detect sub-surface defects of bakelite material is proportionately related with the size of defect diameter if the defects are at the same depth. On the contrary, the sensitivity of the pulsed thermography technique inversely related with the depth of defect if the defects have similar diameter size. (Author)

Novel rattling of K atoms in aluminium-doped defect pyrochlore tungstate

International Nuclear Information System (INIS)

Shoko, Elvis; Kearley, Gordon J; Peterson, Vanessa K; Thorogood, Gordon J; Mutka, Hannu; Koza, Michael M; Yamaura, Jun-ichi; Hiroi, Zenji

2014-01-01

Rattling dynamics have been identified as fundamental to superconductivity in defect pyrochlore osmates and aluminium vanadium intermetallics, as well as low thermal conductivity in clathrates and filled skutterudites. Combining inelastic neutron scattering (INS) measurements and ab initio molecular dynamics (MD) simulations, we use a new approach to investigate rattling in the Al-doped defect pyrochlore tungstates: AAl 0.33 W 1.67 O 6 (A = K, Rb, Cs). We find that although all the alkali metals rattle, the rattling of the K atoms is unique, not only among the tungstates but also among the analogous defect osmates, KOs 2 O 6 and RbOs 2 O 6 . Detailed analysis of the MD trajectories reveals that two unique features set the K dynamics apart from the rest, namely, (1) quasi one-dimensional local diffusion within a cage, and (2) vibration at a range of frequencies. The local diffusion is driven by strongly anharmonic local potentials around the K atoms exhibiting a double-well structure in the direction of maximum displacement, which is also the direction of local diffusion. On the other hand, vibration at a range of frequencies is a consequence of the strong anisotropy in the local potentials around the K atoms as revealed by directional magnitude spectra. We present evidence to show that it is the smaller size rather than the smaller mass of the K rattler which leads to the unusual dynamics. Finally, we suggest that the occurrence of local diffusion and vibration at a range of frequencies in the dynamics of a single rattler, as found here for the K atoms, may open new possibilities for phonon engineering in thermoelectric materials. (paper)

Topological materials discovery using electron filling constraints

Science.gov (United States)

Chen, Ru; Po, Hoi Chun; Neaton, Jeffrey B.; Vishwanath, Ashvin

2018-01-01

Nodal semimetals are classes of topological materials that have nodal-point or nodal-line Fermi surfaces, which give them novel transport and topological properties. Despite being highly sought after, there are currently very few experimental realizations, and identifying new materials candidates has mainly relied on exhaustive database searches. Here we show how recent studies on the interplay between electron filling and nonsymmorphic space-group symmetries can guide the search for filling-enforced nodal semimetals. We recast the previously derived constraints on the allowed band-insulator fillings in any space group into a new form, which enables effective screening of materials candidates based solely on their space group, electron count in the formula unit, and multiplicity of the formula unit. This criterion greatly reduces the computation load for discovering topological materials in a database of previously synthesized compounds. As a demonstration, we focus on a few selected nonsymmorphic space groups which are predicted to host filling-enforced Dirac semimetals. Of the more than 30,000 entires listed, our filling criterion alone eliminates 96% of the entries before they are passed on for further analysis. We discover a handful of candidates from this guided search; among them, the monoclinic crystal Ca2Pt2Ga is particularly promising.

Color stability of bulk-fill and incremental-fill resin-based composites polished with aluminum-oxide impregnated disks

Directory of Open Access Journals (Sweden)

Uzay Koc-Vural

2017-05-01

Full Text Available Objectives This study aimed to evaluate the color stability of bulk-fill and nanohybrid resin-based composites polished with 3 different, multistep, aluminum-oxide impregnated finishing and polishing disks. Materials and Methods Disk-shaped specimens (8 mm in diameter and 4 mm in thickness were light-cured between two glass slabs using one nanohybid bulk-fill (Tetric EvoCeram, Ivoclar Vivadent, one micro-hybrid bulk-fill (Quixfil, Dentsply, and two nanohybrid incremental-fill (Filtek Ultimate, 3M ESPE; Herculite XRV Ultra, Kerr resin-based composites, and aged by thermocycling (between 5 - 55℃, 3,000 cycles. Then, they were divided into subgroups according to the polishing procedure as SwissFlex (Coltène/Whaledent, Optidisc (Kerr, and Praxis TDV (TDV Dental (n = 12 per subgroup. One surface of each specimen was left unpolished. All specimens were immersed in coffee solution at 37℃. The color differences (ΔE were measured after 1 and 7 days of storage using a colorimeter based on CIE Lab system. The data were analyzed by univariate ANOVA, Mann-Whitney U test, and Friedmann tests (α = 0.05. Results Univariate ANOVA detected significant interactions between polishing procedure and composite resin and polishing procedure and storage time (p 0.05. Polishing reduced the discoloration resistance of Tetric EvoCeram/SwissFlex, Tetric EvoCeram/Praxis TDV, Quixfil-SwissFlex, and all Herculite XRV Ultra groups after 7 days storage (p < 0.05. Conclusions Discoloration resistance of bulk-fill resin-based composites can be significantly affected by the polishing procedures.

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

DEFF Research Database (Denmark)

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

2017-01-01

grouped according to defect filling: (1) Empty, (2) Allograft, (3) GBM, (4) GBM + ZA, and (5) GBM + ZA + BMP-2. In vivo microcomputed tomography (micro-CT) images at 4 weeks showed significantly higher mineralized tissue volume (MV) in the intramedullary defect region and the neocortical/callus region...... in all GBM-treated groups. After euthanization at 8 weeks, ex vivo micro-CT showed that addition of ZA (GBM + ZA) and BMP-2 (GBM + ZA + BMP-2) mainly increased the neocortical and callus formation, with the highest MV in the combined ZA and BMP-2-treated group. Qualitative histological analysis......, verifying the increased neocortical/callus thickness and finding of trabecular bone in all GBM-treated groups, supported that the differences in MV measured with micro-CT in fact represented bone tissue. In conclusion, GBM can serve as a carrier for ZA and BMP-2 leading to increased MV in the neocortex...

Simulation of mould filling process for composite skeleton castings

Directory of Open Access Journals (Sweden)

M. Dziuba

2008-04-01

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

Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study.

Science.gov (United States)

Chadda, Harshita; Naveen, Sangeetha Vasudevaraj; Mohan, Saktiswaren; Satapathy, Bhabani K; Ray, Alok R; Kamarul, Tunku

2016-07-01

Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail. The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination. Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software. Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis. The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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.

46 CFR 151.03-21 - Filling density.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Filling density. 151.03-21 Section 151.03-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-21 Filling density. The ratio, expressed as...

Microtensile bond strength of bulk-fill restorative composites to dentin.

Science.gov (United States)

Mandava, Jyothi; Vegesna, Divya-Prasanna; Ravi, Ravichandra; Boddeda, Mohan-Rao; Uppalapati, Lakshman-Varma; Ghazanfaruddin, M D

2017-08-01

To facilitate the easier placement of direct resin composite in deeper cavities, bulk fill composites have been introduced. The Mechanical stability of fillings in stress bearing areas restored with bulk-fill resin composites is still open to question, since long term clinical studies are not available so far. Thus, the objective of the study was to evaluate and compare the microtensile bond strength of three bulk-fill restorative composites with a nanohybrid composite. Class I cavities were prepared on sixty extracted mandibular molars. Teeth were divided into 4 groups (n= 15 each) and in group I, the prepared cavities were restored with nanohybrid (Filtek Z250 XT) restorative composite in an incremental manner. In group II, III and IV, the bulk-fill composites (Filtek, Tetric EvoCeram, X-tra fil bulk-fill restoratives) were placed as a 4 mm single increment and light cured. The restored teeth were subjected to thermocycling and bond strength testing was done using instron testing machine. The mode of failure was assessed by scanning electron microscope (SEM). The bond strength values obtained in megapascals (MPa) were subjected to statistical analysis, using SPSS/PC version 20 software.One-way ANOVA was used for groupwise comparison of the bond strength. Tukey's Post Hoc test was used for pairwise comparisons among the groups. The highest mean bond strength was achieved with Filtek bulk-fill restorative showing statistically significant difference with Tetric EvoCeram bulk-fill ( p composites. Adhesive failures are mostly observed with X-tra fil bulk fill composites, whereas mixed failures are more common with other bulk fill composites. Bulk-fill composites exhibited adequate bond strength to dentin and can be considered as restorative material of choice in posterior stress bearing areas. Key words: Bond strength, Bulk-fill restoratives, Configuration factor, Polymerization shrinkage.

Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Controlled Retention of BMP-2-Derived Peptide on Nanofibers Based on Mussel-Inspired Adhesion for Bone Formation.

Science.gov (United States)

Lee, Jinkyu; Perikamana, Sajeesh Kumar Madhurakkat; Ahmad, Taufiq; Lee, Min Suk; Yang, Hee Seok; Kim, Do-Gyoon; Kim, Kyobum; Kwon, Bosun; Shin, Heungsoo

2017-04-01

Although bone morphogenetic protein-2 (BMP-2) has been frequently used to stimulate bone formation, it has several side effects to be addressed, including the difficulty in optimization of clinically relevant doses and unwanted induction of cancerous signaling processes. In this study, an osteogenic peptide (OP) derived from BMP-2 was investigated as a substitute for BMP-2. In vitro studies showed that OP was able to enhance the osteogenic differentiation and mineralization of human mesenchymal stem cells (hMSCs). The peptides were then conjugated onto biocompatible poly-ι-lactide electrospun nanofibers through polydopamine chemistry. Surface chemical analysis proved that more than 80% of the peptides were stably retained on the nanofiber surface after 8 h of polydopamine coating during at least 28 days, and the amount of peptides that was retained increased depending on the polydopamine coating time. For instance, about 65% of the peptides were retained on nanofibers after 4 h of polydopamine coating. Also, a relatively small dose of peptides could effectively induce bone formation in in vivo critical-sized defects on the calvarial bones of mice. More than 50.4% ± 16.9% of newly formed bone was filled within the defect after treatment with only 10.5 ± 0.6 μg of peptides. Moreover, these groups had similar elastic moduli and contact hardnesses with host bone. Taken together, our results suggest that polydopamine-mediated OP immobilized on nanofibers can modulate the retention of relatively short lengths of peptides, which might make this an effective therapeutic remedy to guide bone regeneration using a relatively small amount of peptides.

3D Analysis of D-RaCe and Self-Adjusting File in Removing Filling Materials from Curved Root Canals Instrumented and Filled with Different Techniques

Directory of Open Access Journals (Sweden)

Neslihan Simsek

2014-01-01

Full Text Available The aim of this study was to compare the efficacy of D-RaCe files and a self-adjusting file (SAF system in removing filling material from curved root canals instrumented and filled with different techniques by using microcomputed tomography (micro-CT. The mesial roots of 20 extracted mandibular first molars were used. Root canals (mesiobuccal and mesiolingual were instrumented with SAF or Revo-S. The canals were then filled with gutta-percha and AH Plus sealer using cold lateral compaction or thermoplasticized injectable techniques. The root fillings were first removed with D-RaCe (Step 1, followed by Step 2, in which a SAF system was used to remove the residual fillings in all groups. Micro-CT scans were used to measure the volume of residual filling after root canal filling, reinstrumentation with D-RaCe (Step 1, and reinstrumentation with SAF (Step 2. Data were analyzed using Wilcoxon and Kruskal-Wallis tests. There were no statistically significant differences between filling techniques in the canals instrumented with SAF (P=0.292 and Revo-S (P=0.306. The amount of remaining filling material was similar in all groups (P=0.363; all of the instrumentation techniques left filling residue inside the canals. However, the additional use of SAF was more effective than using D-RaCe alone.

The combined use of scanning vibrating electrode technique and micro-potentiometry to assess the self-repair processes in defects on 'smart' coatings applied to galvanized steel

Energy Technology Data Exchange (ETDEWEB)

Taryba, M. [ICEMS, Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Lamaka, S.V., E-mail: sviatlana.lamaka@ist.utl.p [ICEMS, Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Snihirova, D. [ICEMS, Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Ferreira, M.G.S. [ICEMS, Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); CICECO, Dep. Ceramics and Glass Eng., University of Aveiro, 3810-193 Aveiro (Portugal); Montemor, M.F. [ICEMS, Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Wijting, W.K.; Toews, S.; Grundmeier, G. [Institute for Polymer Materials and Processes, University of Paderborn, 33098 Paderborn (Germany)

2011-04-30

Research highlights: {yields} Weldable primers were modified with submicron containers loaded with corrosion inhibitors. {yields} SVET and micro-potentiometry were used to study the corrosion inhibition ability. {yields} Submicron containers do not damage the barrier properties of model primers. {yields} Artificial defects of 50{mu}m x 50 {mu}m in a coating can be easily analyzed by SVET and SIET. {yields} Inhibiting dissolution of sacrificial Zn may result in detrimental dissolution of Fe. - Abstract: Model weldable primer coatings for galvanized steel were modified with submicron containers loaded with corrosion inhibitors. This procedure aims at introducing a new functionality in the thin coatings self-repair ability. The assessment of this property demands new protocols and new approaches, combining conventional electrochemical methods with electrochemical and analytical techniques of micrometer spatial resolution. Thus, in this work model defects were created in the coatings by using a focused ion beam (FIB). The coated samples, containing the model defects, were immersed in a NaCl 0.05 M solution and the corrosion inhibition ability was studied using the scanning vibrating electrode technique (SVET) and the scanning ion-selective electrode technique (SIET). SVET-SIET measurements were performed quasi-simultaneously. Qualitative chemical analysis was performed by SEM combined with EDS. Complementary studies were carried out by electrochemical impedance spectroscopy (EIS) to assess the effect of the containers filled with corrosion inhibitors on the barrier properties of the coatings. The electrochemical results highlight the importance of the combined use of integral and localized electrochemical techniques to extract information for a better understanding of the corrosion processes and corresponding repair of active microscopic defects formed on thin coatings containing inhibitor filled containers.

Surface defects and chiral algebras

Energy Technology Data Exchange (ETDEWEB)

Córdova, Clay [School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, NJ 08540 (United States); Gaiotto, Davide [Perimeter Institute for Theoretical Physics,31 Caroline St N, Waterloo, ON N2L 2Y5 (Canada); Shao, Shu-Heng [School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, NJ 08540 (United States)

2017-05-26

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 Drinfeld-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. In each case we find perfect agreement with the predicted characters.

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

Science.gov (United States)

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...

Repair of articular cartilage and subchondral defects in rabbit knee joints with a polyvinyl alcohol/nano-hydroxyapatite/polyamide 66 biological composite material.

Science.gov (United States)

Guo, Tao; Tian, Xiaobin; Li, Bo; Yang, Tianfu; Li, Yubao

2017-11-15

This study sought to prepare a new PVA/n-HA/PA66 composite to investigate the repair of articular cartilage and subchondral defects in rabbit knee joints. A 5 × 5 × 5 mm-sized defect was created in the patellofemoral joints of 72 healthy adult New Zealand rabbits. The rabbits were then randomly divided into three groups (n = 24): PVA/n-HA+PA66 group, polyvinyl alcohol (PVA) group, and control (untreated) group. Cylindrical PVA/n-HA+PA66, 5 × 5 mm, comprised an upper PVA layer and a lower n-HA+PA66 layer. Macroscopic and histological evaluations were performed at 4, 8, 12, and 24 weeks, postoperatively. Type II collagen was measured by immunohistochemical staining. The implant/cartilage and bone interfaces were observed by scanning electron microscopy. At 24 weeks postoperatively, the lower PVA/n-HA+PA66 layer became surrounded by cartilage, with no obvious degeneration. In the PVA group, an enlarged space was observed between the implant and the host tissue that had undergone degeneration. In the control group, the articular cartilage had become calcified. In the PVA/n-HA+PA66 group, positive type II collagen staining was observed between the composite and the surrounding cartilage and on the implant surface. In the PVA group, positive staining was slightly increased between the PVA and the surrounding cartilage, but reduced on the PVA surface. In the control group, reduced staining was observed throughout. Scanning electron microscopy showed increased bone tissue in the lower n-HA+PA66 layer that was in close approximation with the upper PVA layer of the composite. In the PVA group, the bone tissue around the material had receded, and in the control group, the defect was filled with bone tissue, while the superior aspect of the defect was filled with disordered, fibrous tissue. The diphase biological composite material PVA/n-HA+PA66 exhibits good histocompatibility and offers a satisfactory substitute for articular cartilage and subchondral bone.

Self-expanding nanoplatinum-coated nitinol devices for atrial septal defect and patent ductus arteriosus closure: a swine model.

Science.gov (United States)

Lertsapcharoen, Pornthep; Khongphatthanayothin, Apichai; La-orkhun, Vidhavas; Supachokchaiwattana, Pentip; Charoonrut, Phingphol

2006-01-01

Our purpose was to evaluate self-expanding nanoplatinum-coated nitinol devices for transcatheter closure of atrial septal defects and patent ductus arteriosus in a swine model. The devices were braided from platinum-activated nitinol wires and filled with polyester to enhance thrombogenicity. The platinum activation of the nitinol wires was carried out with the help of Nanofusion technology. The coating of platinum covers the exposed surface of the nitinol wires and prevents the release of nickel into the blood stream after the implantation of the device but does not affect its shape memory, which makes the device self-expanding after it is loaded from the catheter. Atrial septal defects were created in 12 piglets by balloon dilation of the patent foramen ovale. The size of the device was selected on the basis of the diameter of the balloon and the size of the defect, measured by transthoracic echocardiography. The devices were successfully deployed in all 12 piglets under fluoroscopic study. Transthoracic color Doppler echocardiograms showed complete closure of the atrial septal defect within 15 minutes of device implantation. Twelve patent ductus arteriosus closure devices were deployed in the right or left subclavian arteries in 10 piglets. Angiograms showed complete occlusion of the subclavian arteries within a few minutes of device deployment. In the atrial septal defect cases, the autopsy findings showed complete organizing fibrin thrombus formation and complete neo-endothelialization on the outer surface of the devices within one week and six weeks of implantation, respectively. The use of self-expanding nanoplatinum-coated nitinol devices for the transcatheter closure of atrial septal defects and patent ductus arteriosus is feasible. The excellent occlusion result and complete neo-endothelialization of the devices in the swine model is an indication of the potential of these devices in human application.

Physico-mechanical characteristics of commercially available bulk-fill composites.

Science.gov (United States)

Leprince, Julian G; Palin, William M; Vanacker, Julie; Sabbagh, Joseph; Devaux, Jacques; Leloup, Gaetane

2014-08-01

Bulk-fill composites have emerged, arguably, as a new "class" of resin-based composites, which are claimed to enable restoration in thick layers, up to 4mm. The objective of this work was to compare, under optimal curing conditions, the physico-mechanical properties of most currently available bulk-fill composites to those of two conventional composite materials chosen as references, one highly filled and one flowable "nano-hybrid" composite. Tetric EvoCeram Bulk Fill (Ivoclar-Vivadent), Venus Bulk Fill (Heraeus-Kulzer), SDR (Dentsply), X-tra Fil (VOCO), X-tra Base (VOCO), Sonic Fill (Kerr), Filtek Bulk Fill (3M-Espe), Xenius (GC) were compared to the two reference materials. The materials were light-cured for 40s in a 2mm×2mm×25mm Teflon mould. Degree of conversion was measured by Raman spectroscopy, Elastic modulus and flexural strength were evaluated by three point bending, surface hardness using Vickers microindentation before and after 24h ethanol storage, and filler weight content by thermogravimetric analysis. The ratio of surface hardness before and after ethanol storage was considered as an evaluation of polymer softening. Data were analyzed by one-way ANOVA and post hoc Tukey's test (p=0.05). The mechanical properties of the bulk-fill composites were mostly lower compared with the conventional high viscosity material, and, at best, comparable to the conventional flowable composite. Linear correlations of the mechanical properties investigated were poor with degree of conversion (0.090.8). Softening in ethanol revealed differences in polymer network density between material types. The reduction of time and improvement of convenience associated with bulk-fill materials is a clear advantage of this particular material class. However, a compromise with mechanical properties compared with more conventional commercially-available nano-hybrid materials was demonstrated by the present work. Given the lower mechanical properties of most bulk-fill materials

21 CFR 872.3310 - Coating material for resin fillings.

Science.gov (United States)

2010-04-01

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

Localized ridge defect augmentation using human pericardium membrane and demineralized bone matrix.

Science.gov (United States)

Vidyadharan, Arun Kumar; Ravindran, Anjana

2014-01-01

Patient wanted to restore her lost teeth with implants in the lower left first molar and second premolar region. Cone beam computerized tomography (CBCT) revealed inadequate bone width and height around future implant sites. The extraction socket of second premolar area revealed inadequate socket healing with sparse bone fill after 4 months of extraction. To evaluate the clinical feasibility of using a collagen physical resorbable barrier made of human pericardium (HP) to augment localized alveolar ridge defects for the subsequent placement of dental implants. Ridge augmentation was done in the compromised area using Puros® demineralized bone matrix (DBM) Putty with chips and an HP allograft membrane. Horizontal (width) and vertical hard tissue measurements with CBCT were recorded on the day of ridge augmentation surgery, 4 month and 7 months follow-up. Intra oral periapical taken 1 year after implant installation showed minimal crestal bone loss. Bone volume achieved through guided bone regeneration was a gain of 4.8 mm horizontally (width) and 6.8 mm vertically in the deficient ridge within a period of 7 months following the procedure. The results suggested that HP Allograft membrane may be a suitable component for augmentation of localized alveolar ridge defects in conjunction with DBM with bone chips.

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2011-01-01

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

Toughening Mechanisms in Silica-Filled Epoxy Nanocomposites

Science.gov (United States)

Patel, Binay S.

Epoxies are widely used as underfill resins throughout the microelectronics industry to mechanically couple and protect various components of flip-chip assemblies. Generally rigid materials largely surround underfill resins. Improving the mechanical and thermal properties of epoxy resins to better match those of their rigid counterparts can help extend the service lifetime of flip-chip assemblies. Recently, researchers have demonstrated that silica nanoparticles are effective toughening agents for lightly-crosslinked epoxies. Improvements in the fracture toughness of silica-filled epoxy nanocomposites have primarily been attributed to two toughening mechanisms: particle debonding with subsequent void growth and matrix shear banding. Various attempts have been made to model the contribution of these toughening mechanisms to the overall fracture energy observed in silica-filled epoxy nanocomposites. However, disparities still exist between experimental and modeled fracture energy results. In this dissertation, the thermal, rheological and mechanical behavior of eight different types of silica-filled epoxy nanocomposites was investigated. Each nanocomposite consisted of up to 10 vol% of silica nanoparticles with particle sizes ranging from 20 nm to 200 nm, with a variety of surface treatments and particle structures. Fractographical analysis was conducted with new experimental approaches in order to accurately identify morphological evidence for each proposed toughening mechanism. Overall, three major insights into the fracture behavior of real world silica-filled epoxy nanocomposites were established. First, microcracking was observed as an essential toughening mechanism in silica-filled epoxy nanocomposites. Microcracking was observed on the surface and subsurface of fractured samples in each type of silica-filled epoxy nanocomposite. The additional toughening contribution of microcracking to overall fracture energy yielded excellent agreement between experimental

Defects at oxide surfaces

CERN Document Server

Thornton, Geoff

2015-01-01

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

Osseous Flap of Galea and Periosteum Filled With Mesenchymal Stem Cells, Platelet-Rich Plasma, Bone Dust, and Hyaluronic Acid.

Science.gov (United States)

Brock, Ryane Schmidt; Viterbo, Fausto; Deffune, Elenice; Domingues, Maria Aparecida Custodio; Mamprim, Maria Jaqueline; Paschoalinotte, Eloisa Elena

2017-10-01

Reconstructive surgery to craniofacial deformities caused by tumor ressections, traumas or congenital malformation are frequent in medicine practice. It aims to provide the patients with better quality of life and functional improvement of speech, breathing, chewing, and swallowing. Many are the techniques described in the literature to recover bone defects. This study evaluated a vascularized galeal and periosteum flap in rabbits, which could possibly substitute the bone graft in reconstructive surgery, especially for facial defects. It involved rabbits, divided into 12 groups, submitted to a surgical procedure to construct the galea and periosteum cranial flap filled with fragments of cranial bone, platelet-rich plasma, mesenchimal stem cells, and hyaluronic acid. The evaluation methods included image examinations and histological analysis.The results demonstrated bone formation with the use of platelet-rich plasma, mesenchimal stem cells, and bone fragments. The use of several enrichment materials of osseous cellular stimulation improved the quality and bone tissue organization. The more enrichment factor used, the better the tissue quality result was.Much research should be done to improve the methods and to analyze if results in human have the same bone formation as it happened in rabbits.

48 CFR 1615.407-1 - Rate reduction for defective pricing or defective cost or pricing data.

Science.gov (United States)

2010-10-01

... defective pricing or defective cost or pricing data. 1615.407-1 Section 1615.407-1 Federal Acquisition... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 1615.407-1 Rate reduction for defective pricing or defective cost or pricing data. The clause set forth in section 1652.215-70...

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

Science.gov (United States)

2010-10-01

... Defective Pricing or Defective Cost or Pricing Data. 1652.215-70 Section 1652.215-70 Federal Acquisition... CLAUSES AND FORMS CONTRACT CLAUSES Texts of FEHBP Clauses 1652.215-70 Rate Reduction for Defective Pricing or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall be...

Grain-filling duration and grain yield relationships in wheat mutants

International Nuclear Information System (INIS)

Larik, A.S.

1987-01-01

Nine stable mutants of bread wheat along with their mother cultivars were investigated for grain-filling characteristics in relation to grain yield. Significant differences among mutants for grain-filling duration and grain-filling index were observed. Inspite of the consistent differences in grain-filling duration there was no significant association between grain-filling duration and grain yield in C-591 and Nayab mutants. Failure to detect an yield advantage due to differences in grain-filling duration in these genotypes suggests that any advantage derived from alteration of grain-filling period may have been outweighed by the coincident changes in length of the vegetative period. Other factors such as synchrony of anthesis may have limited out ability to find an association between grainfilling duration and grain yield. On the contrary, significant association between grain-filling duration and grain yield displayed by indus-66 indus-66 mutants derived from gamma rays, shows the ability of gamma rays to induce functional alternations in the pattern of gene arrangements controlling these traits. Thus, the vaability observed in these physiological traits suggests that selection for these traits could be useful in improving grain yield. (author)

Point defects in platinum

International Nuclear Information System (INIS)

Piercy, G.R.

1960-01-01

An investigation was made of the mobility and types of point defect introduced in platinum by deformation in liquid nitrogen, quenching into water from 1600 o C, or reactor irradiation at 50 o C. In all cases the activation energy for motion of the defect was determined from measurements of electrical resistivity. Measurements of density, hardness, and x-ray line broadening were also made there applicable. These experiments indicated that the principal defects remaining in platinum after irradiation were single vacant lattice sites and after quenching were pairs of vacant lattice sites. Those present after deformation In liquid nitrogen were single vacant lattice sites and another type of defect, perhaps interstitial atoms. (author)

QENS investigation of filled rubbers

CERN Document Server

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

2002-01-01

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

Reconstruction of irradiated bone segmental defects with a biomaterial associating MBCP+(R), microstructured collagen membrane and total bone marrow grafting: an experimental study in rabbits.

Science.gov (United States)

Jégoux, Franck; Goyenvalle, Eric; Cognet, Ronan; Malard, Olivier; Moreau, Francoise; Daculsi, Guy; Aguado, Eric

2009-12-15

The bone tissue engineering models used today are still a long way from any oncologic application as immediate postimplantation irradiation would decrease their osteoinductive potential. The aim of this study was to reconstruct a segmental critical size defect in a weight-bearing bone irradiated after implantation. Six white New Zealand rabbits were immediately implanted with a biomaterial associating resorbable collagen membrane EZ(R) filled and micro-macroporous biphasic calcium phosphate granules (MBCP+(R)). After a daily schedule of radiation delivery, and within 4 weeks, a total autologous bone marrow (BM) graft was injected percutaneously into the center of the implant. All the animals were sacrificed at 16 weeks. Successful osseous colonization was found to have bridged the entire length of the defects. Identical distribution of bone ingrowth and residual ceramics at the different levels of the implant suggests that the BM graft plays an osteoinductive role in the center of the defect. Periosteum-like formation was observed at the periphery, with the collagen membrane most likely playing a role. This model succeeded in bridging a large segmental defect in weight-bearing bone with immediate postimplantation fractionated radiation delivery. This has significant implications for the bone tissue engineering approach to patients with cancer-related bone defects.

Calcium phosphate barrier for augmentation of bone in noncontained periodontal osseous defects: a novel approach.

Science.gov (United States)

Chopra, Aditi; Sivaraman, Karthik; Awataramaney, Tarun K

2014-11-01

The aim of this technique is to augment bone in non-contained osseous deformities using a unique self-sustaining calcium phosphate barrier. Bone has the inherent ability to regenerate completely if it is provided with a fracture space or an undisturbed enclosed scaffold. A secluded environment is essential as it provides a secured, sterile and stable wound system that regenerates lost bone by a process of osteopromotion. Reconstructive techniques using bone grafts and barrier membranes utilize this principle for augmentation of deficient bony sites by providing a closed environment that promotes clot stability, graft retention, and facilitates correct cell repopulation. However, in noncontained bone defects like one walled infrabony periodontal defect or sites with horizontal bone loss, regeneration of bone still remains an unrealistic situation since osseous topography at such sites does not favor membrane stability or bone grafts retention. This case report presents a promising technique to augment bone in areas with horizontal loss. Augmentation of bone in the interdental area with horizontal bone loss was accomplished by building a contained defect using a unique self sustaining calcium phosphate cement formulation. The calcium phosphate barrier stimulates the lost cortical plates and promotes graft retention and clot stability. At 6 months, there was a significant bone fill and trabecular formation in the interdental area and reduction in tooth mobility. This promising technique could prove to be a good alternative to the conventional approaches for treating osseous deformities. Calcium phosphate is a promising barrier graft for repair of noncontained periodontal osseous defect. This technique cues both the clinicians and manufacturers to develop moldable tissue engineered constructs for osseous repair.

Post-cure depth of cure of bulk fill dental resin-composites.

Science.gov (United States)

Alrahlah, A; Silikas, N; Watts, D C

2014-02-01

To determine the post-cure depth of cure of bulk fill resin composites through using Vickers hardness profiles (VHN). Five bulk fill composite materials were examined: Tetric EvoCeram(®) Bulk Fill, X-tra base, Venus(®) Bulk Fill, Filtek™ Bulk Fill, SonicFill™. Three specimens of each material type were prepared in stainless steel molds which contained a slot of dimensions (15 mm × 4 mm × 2 mm), and a top plate. The molds were irradiated from one end. All specimens were stored at 37°C for 24h, before measurement. The Vickers hardness was measured as a function of depth of material, at 0.3mm intervals. Data were analysed by one-way ANOVA using Tukey post hoc tests (α=0.05). The maximum VHN ranged from 37.8 to 77.4, whilst the VHN at 80% of max.VHN ranged from 30.4 to 61.9. The depth corresponding to 80% of max.VHN, ranged from 4.14 to 5.03 mm. One-way ANOVA showed statistically significant differences between materials for all parameters tested. SonicFill exhibited the highest VHN (pFill the lowest (p≤0.001). SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure (5.03 and 4.47 mm, respectively) and was significant's different from X-tra base, Venus Bulk Fill and Filtek Bulk Fill (p≤0.016). Linear regression confirmed a positive regression between max.VHN and filler loading (r(2)=0.94). Bulk fill resin composites can be cured to an acceptable post-cure depth, according to the manufacturers' claims. SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure among the composites examined. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Stability of fruit bases and chocolate fillings

Directory of Open Access Journals (Sweden)

Joice Natali Miquelim

2011-03-01

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

46 CFR 98.25-50 - Filling and discharge pipes.

Science.gov (United States)

2010-10-01

... with a secondary remote control of a type acceptable to the Commandant. (c) The excess flow, internal... 46 Shipping 4 2010-10-01 2010-10-01 false Filling and discharge pipes. 98.25-50 Section 98.25-50... § 98.25-50 Filling and discharge pipes. (a) Filling connections shall be provided with one of the...

MSCT diagnosis of pulmonary embolism

International Nuclear Information System (INIS)

Fang Jie; Yang Li; Zhang Ailian; Li Gongjie; Ren Shuanqun

2004-01-01

Objective: To analyze the distribution and size of intraluminal filling defects and corresponding parenchymal findings in pulmonary embolism (PE) on MSCT. Methods: Twelve PE cases diagnosed by spiral CTA were retrospected. The involved pulmonary arteries according to presence of filling defects were classified as central, peripheral and mixed type. Lobular pulmonary artery with filling defects classified as complete defect and partial defects. The presence or absence of parenchymal abnormalities and pleural effusion was noted. Results: Peripheral PE was identified in 2 of the 12 patients with PE, and others were with mixed type. Anatomic evaluation of filling defects at lobular level revealed a total of 25 arteries in 12 patients including 9 with complete filling defect and 16 with partial filling defect. Only 3 cases were found to have parenchyma consolidation from all the 12 cases, and 1 case was diagnosed as pneumonia. Pleural effusion was seen in 4 cases. Conclusion: Parenchymal changes in PE do not often take place and lack specified signs. Diagnosis of PE is based on conformation of parenchymal changes with occluded segment of pulmonary arteries. Clinical history and follow up are of very importance in defining parenchyma change arose from PE. (authors)

On the influence of extrinsic point defects on irradiation-induced point-defect distributions in silicon

International Nuclear Information System (INIS)

Vanhellemont, J.; Romano-Rodriguez, A.

1994-01-01

A semi-quantitative model describing the influence of interfaces and stress fields on {113}-defect generation in silicon during 1-MeV electron irradiation, is further developed to take into account also the role of extrinsic point defects. It is shown that the observed distribution of {113}-defects in high-flux electron-irradiated silicon and its dependence on irradiation temperature and dopant concentration can be understood by taking into account not only the influence of the surfaces and interfaces as sinks for intrinsic point defects but also the thermal stability of the bulk sinks for intrinsic point defects. In heavily doped silicon the bulk sinks are related with pairing reactions of the dopant atoms with the generated intrinsic point defects or related with enhanced recombination of vacancies and self-interstitials at extrinsic point defects. The obtained theoretical results are correlated with published experimental data on boron-and phosphorus-doped silicon and are illustrated with observations obtained by irradiating cross-section transmission electron microscopy samples of wafer with highly doped surface layers. (orig.)

Excavation/Fill/Soil Disturbance, Self-Study #31419

Energy Technology Data Exchange (ETDEWEB)

Grogin, Phillip W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-02-06

This course, Excavation/Fill/Soil Disturbance Self-Study (#31419), presents an overview of the hazards, controls, and requirements that affect safe excavations at Los Alamos National Laboratory (LANL). An overview of the LANL excavation/fill/soil disturbance permit (EXID permit) approval process is also presented, along with potholing requirements for planning and performing excavations at LANL.

Congenital Heart Defects and CCHD

Science.gov (United States)

... and more. Stony Point, NY 10980 Close X Home > Complications & Loss > Birth defects & other health conditions > Congenital heart defects and ... in congenital heart defects. You have a family history of congenital heart ... syndrome or VCF. After birth Your baby may be tested for CCHD as ...

Neutron diffraction and lattice defects

International Nuclear Information System (INIS)

Hamaguchi, Yoshikazu

1974-01-01

Study on lattice defects by neutron diffraction technique is described. Wave length of neutron wave is longer than that of X-ray, and absorption cross-section is small. Number of defects observed by ESR is up to several defects, and the number studied with electron microscopes is more than 100. Information obtained by neutron diffraction concerns the number of defects between these two ranges. For practical analysis, several probable models are selected from the data of ESR or electron microscopes, and most probable one is determined by calculation. Then, defect concentration is obtained from scattering cross section. It is possible to measure elastic scattering exclusively by neutron diffraction. Minimum detectable concentration estimated is about 0.5% and 10 20 - 10 21 defects per unit volume. A chopper and a time of flight system are used as a measuring system. Cold neutrons are obtained from the neutron sources inserted into reactors. Examples of measurements by using similar equipments to PTNS-I system of Japan Atomic Energy Research Institute are presented. Interstitial concentration in the graphite irradiated by fast neutrons is shown. Defects in irradiated MgO were also investigated by measuring scattering cross section. Study of defects in Ge was made by measuring total cross section, and model analysis was performed in comparison with various models. (Kato, T.)

A roentgenographic assessment of regenerative efficacy of bioactive Gengigel® in conjunction with amnion membrane in grade II furcation defect

Directory of Open Access Journals (Sweden)

S Harveen Kalra

2015-01-01

Full Text Available Background: Nowadays, techniques are being developed to guide and instruct the specialized cellular components of the periodontium to participate in the regenerative process. This approach of reconstruction makes use of understanding of the development of the periodontium and the cellular processes that are involved. Hyaluronic acid is a naturally occurring non-sulfated high molecular weight glycosaminoglycan that forms a critical component of the extracellular matrix and contributes significantly to tissue hydrodynamics, cell migration, and proliferation. Hence, its administration to periodontal wound sites could achieve comparable beneficial effects in periodontal tissue regeneration. Hence, the purpose of the present case report was to assess roentgenographically, the regenerative capacity of Gengigel® in conjunction with bioactive amnion guided tissue regeneration (GTR membrane in a patient with Grade II furcation defect. Case Presentation: A patient complained of bleeding gums from the lower back tooth region, reportedly found Grade II furcation in the lower right mandibular first molar. After Phase, I therapy, Gengigel® along with bioactive amnion membrane was placed in the furcation area during the surgical phase. Roentgenographic assessment was done at 4 months and 6 months postoperatively. It resulted in complete defect-fill and loss of radiolucency at 6 months. Conclusion: Surgical placement of Gengigel® along with amnion membrane in the furcation defect can significantly improve the periodontal defect morphology.

Varying stiffness and load distributions in defective ball bearings: Analytical formulation and application to defect size estimation

Science.gov (United States)

Petersen, Dick; Howard, Carl; Prime, Zebb

2015-02-01

This paper presents an analytical formulation of the load distribution and varying effective stiffness of a ball bearing assembly with a raceway defect of varying size, subjected to static loading in the radial, axial and rotational degrees of freedom. The analytical formulation is used to study the effect of the size of the defect on the load distribution and varying stiffness of the bearing assembly. The study considers a square-shaped outer raceway defect centered in the load zone and the bearing is loaded in the radial and axial directions while the moment loads are zero. Analysis of the load distributions shows that as the defect size increases, defect-free raceway sections are subjected to increased static loading when one or more balls completely or partly destress when positioned in the defect zone. The stiffness variations that occur when balls pass through the defect zone are significantly larger and change more rapidly at the defect entrance and exit than the stiffness variations that occur for the defect-free bearing case. These larger, more rapid stiffness variations generate parametric excitations which produce the low frequency defect entrance and exit events typically observed in the vibration response of a bearing with a square-shaped raceway defect. Analysis of the stiffness variations further shows that as the defect size increases, the mean radial stiffness decreases in the loaded radial and axial directions and increases in the unloaded radial direction. The effects of such stiffness changes on the low frequency entrance and exit events in the vibration response are simulated with a multi-body nonlinear dynamic model. Previous work used the time difference between the low frequency entrance event and the high frequency exit event to estimate the size of the defect. However, these previous defect size estimation techniques cannot distinguish between defects that differ in size by an integer number of the ball angular spacing, and a third feature

A New Filled Function Method with One Parameter for Global Optimization

Directory of Open Access Journals (Sweden)

Fei Wei

2013-01-01

Full Text Available The filled function method is an effective approach to find the global minimizer of multidimensional multimodal functions. The conventional filled functions are numerically unstable due to exponential or logarithmic term and sensitive to parameters. In this paper, a new filled function with only one parameter is proposed, which is continuously differentiable and proved to satisfy all conditions of the filled function definition. Moreover, this filled function is not sensitive to parameter, and the overflow can not happen for this function. Based on these, a new filled function method is proposed, and it is numerically stable to the initial point and the parameter variable. The computer simulations indicate that the proposed filled function method is efficient and effective.

Afterimage watercolors: an exploration of contour-based afterimage filling-in.

Science.gov (United States)

Hazenberg, Simon J; van Lier, Rob

2013-01-01

We investigated filling-in of colored afterimages and compared them with filling-in of "real" colors in the watercolor illusion. We used shapes comprising two thin adjacent undulating outlines of which the inner or the outer outline was chromatic, while the other was achromatic. The outlines could be presented simultaneously, inducing the original watercolor effect, or in an alternating fashion, inducing colored afterimages of the chromatic outlines. In Experiment 1, using only alternating outlines, these afterimages triggered filling-in, revealing an "afterimage watercolor" effect. Depending on whether the inner or the outer outline was chromatic, filling-in of a complementary or a similarly colored afterimage was perceived. In Experiment 2, simultaneous and alternating presentations were compared. Additionally, gray and black achromatic contours were tested, having an increased luminance contrast with the background for the black contours. Compared to "real" color filling-in, afterimage filling-in was more easily affected by different luminance settings. More in particular, afterimage filling-in was diminished when high-contrast contours were used. In the discussion we use additional demonstrations in which we further explore the "watercolor afterimage." All in all, comparisons between both types of illusions show similarities and differences with regard to color filling-in. Caution, however, is warranted in attributing these effects to different underlying processing differences.

Sorption of Np (Ⅴ) on Beishan granite fracture filling materials

International Nuclear Information System (INIS)

Jiang Tao; Wang Bo; Bao Liangjin; Zhou Duo; Long Haoqi; Song Zhixin; Chen Xi

2012-01-01

The sorption behaviors of Np (Ⅴ) on the granite fracture filling materials were studied by batch experiments under anaerobic in Beishan groundwater. The impact of pH of groundwater, CO 3 2- , humic acid and different components of granite fracture filling materials on sorption of Np (Ⅴ) was investigated. The results show that the granite fracture filling materials have strong capacity of Np (Ⅴ) adsorption. The value of K d , for Np (Ⅴ) sorption on the granite fracture filling materials is 843 mL/g. With the increase of pH, the value of K d increases at first and then decreases. K d of Np sorption on granite fracture filling materials in the presence of CO 3 2- and humic acid decreases. The chlorite and feldspar are major contributors to the sorption of Np (Ⅴ) on Beishan granite fracture filling materials. (authors)

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2014-01-01

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

Computer simulation of defect cluster

Energy Technology Data Exchange (ETDEWEB)

Kuramoto, Eiichi [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

1996-04-01

In order to elucidate individual element process of various defects and defect clusters of used materials under irradiation environments, interatomic potential with reliability was investigated. And for comparison with experimental results, it is often required to adopt the temperature effect and to investigate in details mechanism of one dimensional motion of micro conversion loop and so forth using the molecular dynamic (MD) method. Furthermore, temperature effect is also supposed for stable structure of defects and defect clusters, and many problems relating to alloy element are also remained. And, simulation on photon life at the defects and defect clusters thought to be important under comparison with equipment can also be supposed an improvement of effectiveness due to relation to theses products. In this paper, some topics in such flow was extracted to explain them. In particular, future important problems will be potential preparation of alloy, structure, dynamic behavior and limited temperature of intralattice atomic cluster. (G.K.)

Biocompatibility of root-end filling materials: recent update

Directory of Open Access Journals (Sweden)

Payal Saxena

2013-08-01

Full Text Available The purpose of a root-end filling is to establish a seal between the root canal space and the periradicular tissues. As root-end filling materials come into contact with periradicular tissues, knowledge of the tissue response is crucial. Almost every available dental restorative material has been suggested as the root-end material of choice at a certain point in the past. This literature review on root-end filling materials will evaluate and comparatively analyse the biocompatibility and tissue response to these products, with primary focus on newly introduced materials.

Norwegian Pitched Roof Defects

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Lars Gullbrekken

2016-06-01

Full Text Available The building constructions investigated in this work are pitched wooden roofs with exterior vertical drainpipes and wooden load-bearing system. The aim of this research is to further investigate the building defects of pitched wooden roofs and obtain an overview of typical roof defects. The work involves an analysis of the building defect archive from the research institute SINTEF Building and Infrastructure. The findings from the SINTEF archive show that moisture is a dominant exposure factor, especially in roof constructions. In pitched wooden roofs, more than half of the defects are caused by deficiencies in design, materials, or workmanship, where these deficiencies allow moisture from precipitation or indoor moisture into the structure. Hence, it is important to increase the focus on robust and durable solutions to avoid defects both from exterior and interior moisture sources in pitched wooden roofs. Proper design of interior ventilation and vapour retarders seem to be the main ways to control entry from interior moisture sources into attic and roof spaces.

Congenital platelet function defects

Science.gov (United States)

... pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... Congenital platelet function defects are bleeding disorders that cause reduced platelet function. Most of the time, people with these disorders have ...

Metallography of defects

International Nuclear Information System (INIS)

Borisova, E.A.; Bochvar, G.A.; Brun, M.Ya.

1980-01-01

Different types of defects of metallurgical, technological and exploitation origin in intermediate and final products of titanium alloys, are considered. The examples of metallic and nonmetallic inclusions, chemical homogeneity, different grains, bands, cracks, places of searing, porosity are given; methods of detecting the above defects are described. The methods of metallography, X-ray spectral analysis, measuring microhardness are used

Concrete Cracking Prediction Including the Filling Proportion of Strand Corrosion Products

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Wang, Lei; Dai, Lizhao; Zhang, Xuhui; Zhang, Jianren

2016-01-01

The filling of strand corrosion products during concrete crack propagation is investigated experimentally in the present paper. The effects of stirrups on the filling of corrosion products and concrete cracking are clarified. A prediction model of crack width is developed incorporating the filling proportion of corrosion products and the twisting shape of the strand. Experimental data on cracking angle, crack width, and corrosion loss obtained from accelerated corrosion tests of concrete beams are presented. The proposed model is verified by experimental data. Results show that the filling extent of corrosion products varies with crack propagation. The rust filling extent increases with the propagating crack until a critical width. Beyond the critical width, the rust-filling extent remains stable. Using stirrups can decrease the critical crack width. Stirrups can restrict crack propagation and reduce the rust filling. The tangent of the cracking angle increases with increasing corrosion loss. The prediction of corrosion-induced crack is sensitive to the rust-filling extent. PMID:28772367

A comparative evaluation of porous hydroxyapatite bone graft with and without platelet-rich plasma in the treatment of periodontal intrabony osseous defects: A clinico-Radiographic study

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Gouri Bhatia

2018-01-01

Full Text Available Background: Today, regenerative attempts for treatment of periodontal disease focus on the introduction of a filler material into the defect in hope of inducing bone regeneration. The purpose of this study was to clinically and radiographically evaluate the use of porous hydroxyapatite bone graft with and without platelet-rich plasma (PRP in the treatment of intrabony defects. Materials and Methods: The study was carried out in ten patients between 18 and 60 years. Patients with pocket depth ≥5 mm and radiographic evidence of vertical bone loss in the affected site were randomly assigned to treatment with a combination of PRP + Hydroxyapatite (HA (test sites or HA alone (control sites. The parameters were compared at baseline and 6 months postoperatively. Results: There was a statistically significant reduction in probing depth and gain in clinical attachment in both the groups individually (more in experimental group; however, on comparing the two groups, the net reduction was not significant. Radiographic assessment showed a decrease in the defect size in both the groups. Conclusion: PRP in addition to a bone graft in the treatment of intrabony defects is safe and shows improved defect fill as compared to the use of bone graft alone.

Market Assessment and Demonstration of Lignite FBC Ash Flowable Fill Applications

International Nuclear Information System (INIS)

Alan E. Bland

2003-01-01

Montana-Dakota Utilities (MDU) and Western Research Institute (WRI) have been developing flowable fill materials formulated using ash from the Montana-Dakota Utilities R. M. Heskett Station in Mandan, North Dakota. MDU and WRI have partnered with the U.S. Department of Energy (DOE) and the North Dakota Industrial Commission (NDIC) to further the development of these materials for lignite-fired fluidized-bed combustion (FBC) facilities. The MDU controlled density fill (CDF) appears to be a viable engineering material and environmentally safe. WRI is pursuing the commercialization of the technology under the trademark Ready-Fill(trademark). The project objectives were to: (1) assess the market in the Bismarck-Mandan area; (2) evaluate the geotechnical properties and environmental compatibility; and (3) construct and monitor demonstrations of the various grades of flowable fill products in full-scale demonstrations. The scope of initial phase of work entailed the following: Task I--Assess Market for MDU Flowable Fill Products; Task II--Assess Geotechnical and Environmental Properties of MDU Flowable Fill Products; and Task III--Demonstrate and Monitor MDU Flowable Fill Products in Field-Scale Demonstrations. The results of these testing and demonstration activities proved the following: (1) The market assessment indicated that a market exists in the Bismarck-Mandan area for structural construction applications, such as sub-bases for residential and commercial businesses, and excavatable fill applications, such as gas line and utility trench filling. (2) The cost of the MDU flowable fill product must be lower than the current $35-$45/cubic yard price if it is to become a common construction material. Formulations using MDU ash and lower-cost sand alternatives offer that opportunity. An estimated market of 10,000 cubic yards of MDU flowable fill products could be realized if prices could be made competitive. (3) The geotechnical properties of the MDU ash-based flowable

Market Assessment and Demonstration of Lignite FBC Ash Flowable Fill Applications

Energy Technology Data Exchange (ETDEWEB)

Alan E. Bland

2003-09-30

Montana-Dakota Utilities (MDU) and Western Research Institute (WRI) have been developing flowable fill materials formulated using ash from the Montana-Dakota Utilities R. M. Heskett Station in Mandan, North Dakota. MDU and WRI have partnered with the U.S. Department of Energy (DOE) and the North Dakota Industrial Commission (NDIC) to further the development of these materials for lignite-fired fluidized-bed combustion (FBC) facilities. The MDU controlled density fill (CDF) appears to be a viable engineering material and environmentally safe. WRI is pursuing the commercialization of the technology under the trademark Ready-Fill{trademark}. The project objectives were to: (1) assess the market in the Bismarck-Mandan area; (2) evaluate the geotechnical properties and environmental compatibility; and (3) construct and monitor demonstrations of the various grades of flowable fill products in full-scale demonstrations. The scope of initial phase of work entailed the following: Task I--Assess Market for MDU Flowable Fill Products; Task II--Assess Geotechnical and Environmental Properties of MDU Flowable Fill Products; and Task III--Demonstrate and Monitor MDU Flowable Fill Products in Field-Scale Demonstrations. The results of these testing and demonstration activities proved the following: (1) The market assessment indicated that a market exists in the Bismarck-Mandan area for structural construction applications, such as sub-bases for residential and commercial businesses, and excavatable fill applications, such as gas line and utility trench filling. (2) The cost of the MDU flowable fill product must be lower than the current $35-$45/cubic yard price if it is to become a common construction material. Formulations using MDU ash and lower-cost sand alternatives offer that opportunity. An estimated market of 10,000 cubic yards of MDU flowable fill products could be realized if prices could be made competitive. (3) The geotechnical properties of the MDU ash-based flowable

ADVANTAGES AND DISADVANTAGES OF THE SONICFILL™ METHOD FOR LATERAL FILLINGS

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Nicolae BARANOV

2017-06-01

Full Text Available The aim of the study was to evaluate the advantages and disadvantages of bulk-fill type fillings realized with SONICFill™ over an 18 month interval, on a batch of patients with different ages and occupations. Materials and methods: the study was performed on a batch of 73 patients who addressed the Clinical of OdontologyEndodontics within the Platform of Practical Training (PIP of the Faculty of Dental Medicine of the ”Apollonia” University of Iaşi, between Octomber 1, 2014 - May 1, 2016, subjected to 91 bulk-fill fillings with SonicFill™ on the posterior teeth. Results and discussion: out of the total number of 73 patients, 56 came from the urban environment, and 17 - from the rural medium, the highest ratio being represented by the 21-30 year age group (45%, closely followed by the 31-40 year one (40%. As for gender distribution within the batch, nearly two-thirds are women, the rest being men. The education level influenced patients’ decision – that of accepting a new method of filling application. As to the types of teeth to which restorations were applied, the highest ratio is represented by lower molars (41%, followed by upper molars (23% and mandibular premolars (20%, the lowest number of restorations being applied to maxillary premolars. Out of the total number of 91 bulk-fill restorations, 28 were applied over a base filling while, in 63 restorations, the basic filling was absent. Conclusions: The SonicFill ™ system for bulk-fill posterior restorations has a number of advantages, such as: high photopolymerization depth, significant reduction of setting contraction, better composite adaptation to the cavity walls, long-term predictable clinical results.

A proposed defect tracking model for classifying the inserted defect reports to enhance software quality control.

Science.gov (United States)

Sultan, Torky; Khedr, Ayman E; Sayed, Mostafa

2013-01-01

NONE DECLARED Defect tracking systems play an important role in the software development organizations as they can store historical information about defects. There are many research in defect tracking models and systems to enhance their capabilities to be more specifically tracking, and were adopted with new technology. Furthermore, there are different studies in classifying bugs in a step by step method to have clear perception and applicable method in detecting such bugs. This paper shows a new proposed defect tracking model for the purpose of classifying the inserted defects reports in a step by step method for more enhancement of the software quality.

CHARACTERISTICS OF FLORIDA FILL MATERIALS AND SOILS 1990

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