Sample records for bioprosthetic regenerate template

  1. Redoing a bioprosthetic tricuspid valve replacement with pacemaker wire through the ruined bioprosthetic valve orifice

    Institute of Scientific and Technical Information of China (English)

    GUO Hong-wei; PAN Shi-wei; SONG Yun-hu; HU Sheng-shou


    Severe tricuspid regurgitation with permanent pacemaker wire passing through the orifice of bioprosthetic tricuspid valve is extremely rare. We present a case of such kind of patient and redid bioprosthetic tricuspid valve replacement. A hawk mouth forceps for bone surgery was used to cut off the mental ring of ruined bioprosthetic tricuspid valve and the ruined valve was removed. A new bioprosthetic tricuspid valve was implanted and the wire of permanent pacemaker was left outside the ring of bioprosthetic tricuspid valve. This method may be helpful for such kind of patient.

  2. Enhanced Elastic Modulus of Regenerated Silk Fibroin by Geometric Confinement in Anodized Aluminum Oxide Templates (United States)

    Li, Jiankang; Li, Liang


    Geometric confinement is a promising method for the reconstruction of silk fibroin to form diversified structures with excellent mechanical properties. To accomplish geometric confinement, a water vapor assistant embossing process is used with porous anodic aluminum oxide templates, yielding silk fibroin nanopillars with diameters ranging from 40 nm to 130 nm. The elastic modulus of the regenerated silk fibroin nanopillars is investigated with atomic force microscopy nanoindentation analysis. Compared to films with the same treatment conditions, geometric confinement provided a twofold increase in elastic modulus in embossed silk fibroin nanopillars, indicating that β-sheet crystal ordering occurred during the water vapor assistant embossing process. These results demonstrate the feasibility and mechanical property enhancement of the embossing method to fabricate silk nanostructures, and will be useful in designing miniaturized devices.

  3. Templated agarose scaffolds for the support of motor axon regeneration into sites of complete spinal cord transection. (United States)

    Gao, Mingyong; Lu, Paul; Bednark, Bridget; Lynam, Dan; Conner, James M; Sakamoto, Jeff; Tuszynski, Mark H


    Bioengineered scaffolds have the potential to support and guide injured axons after spinal cord injury, contributing to neural repair. In previous studies we have reported that templated agarose scaffolds can be fabricated into precise linear arrays and implanted into the partially injured spinal cord, organizing growth and enhancing the distance over which local spinal cord axons and ascending sensory axons extend into a lesion site. However, most human injuries are severe, sparing only thin rims of spinal cord tissue in the margins of a lesion site. Accordingly, in the present study we examined whether template agarose scaffolds seeded with bone marrow stromal cells secreting Brain-Derived Neurotrophic Factor (BDNF) would support regeneration into severe, complete spinal cord transection sites. Moreover, we tested responses of motor axon populations originating from the brainstem. We find that templated agarose scaffolds support motor axon regeneration into a severe spinal cord injury model and organize axons into fascicles of highly linear configuration. BDNF significantly enhances axonal growth. Collectively, these findings support the feasibility of scaffold implantation for enhancing central regeneration after even severe central nervous system injury.

  4. BDNF gene delivery within and beyond templated agarose multi-channel guidance scaffolds enhances peripheral nerve regeneration (United States)

    Gao, Mingyong; Lu, Paul; Lynam, Dan; Bednark, Bridget; Campana, W. Marie; Sakamoto, Jeff; Tuszynski, Mark


    Objective. We combined implantation of multi-channel templated agarose scaffolds with growth factor gene delivery to examine whether this combinatorial treatment can enhance peripheral axonal regeneration through long sciatic nerve gaps. Approach. 15 mm long scaffolds were templated into highly organized, strictly linear channels, mimicking the linear organization of natural nerves into fascicles of related function. Scaffolds were filled with syngeneic bone marrow stromal cells (MSCs) secreting the growth factor brain derived neurotrophic factor (BDNF), and lentiviral vectors expressing BDNF were injected into the sciatic nerve segment distal to the scaffold implantation site. Main results. Twelve weeks after injury, scaffolds supported highly linear regeneration of host axons across the 15 mm lesion gap. The incorporation of BDNF-secreting cells into scaffolds significantly increased axonal regeneration, and additional injection of viral vectors expressing BDNF into the distal segment of the transected nerve significantly enhanced axonal regeneration beyond the lesion. Significance. Combinatorial treatment with multichannel bioengineered scaffolds and distal growth factor delivery significantly improves peripheral nerve repair, rivaling the gold standard of autografts.

  5. Percutaneous Valvuloplasty for Bioprosthetic Tricuspid Valve Stenosis (United States)

    Malhotra, Rohit; Sharma, Anjali; Kakouros, Nikolaos


    Percutaneous transcatheter tricuspid balloon valvuloplasty (PTTBV) is an accepted treatment option for symptomatic severe native tricuspid valve stenosis, although surgical tricuspid valve replacement remains the treatment of choice. There have been few reports of successful PTTBV for bioprosthetic tricuspid valve stenosis. We present case reports of 3 patients from our hospital experience. Two of the 3 cases were successful, with lasting clinical improvement, whereas the 3rd patient failed to show a reduction in valve gradient. We describe the standard technique used for PTTBV. We present results from a literature review that identified 16 previously reported cases of PTTBV for bioprosthetic severe tricuspid stenosis, with overall favorable results. We conclude that PTTBV should perhaps be considered for a select patient population in which symptomatic improvement and hemodynamic stability are desired immediately, and particularly for patients who are inoperable or at high surgical risk.

  6. The Mechanical and Biological Properties of Chitosan Scaffolds for Tissue Regeneration Templates Are Significantly Enhanced by Chitosan from Gongronella butleri

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    Hiroshi Tamura


    Full Text Available Chitosan with a molecular weight (MW of 104 Da and 13% degree of acetylation (DA was extracted from the mycelia of the fungus Gongronella butleri USDB 0201 grown in solid substrate fermentation and used to prepare scaffolds by the freeze-drying method. The mechanical and biological properties of the fungal chitosan scaffolds were evaluated and compared with those of scaffolds prepared using chitosans obtained from shrimp and crab shells and squid bone plates (MW 105-106 Da and DA 10-20%. Under scanning electron microscopy, it was observed that all scaffolds had average pore sizes of approximately 60-90 mm in diameter. Elongated pores were observed in shrimp chitosan scaffolds and polygonal pores were found in crab, squid and fungal chitosan scaffolds. The physico-chemical properties of the chitosans had an effect on the formation of pores in the scaffolds, that consequently influenced the mechanical and biological properties of the scaffolds. Fungal chitosan scaffolds showed excellent mechanical, water absorption and lysozyme degradation properties, whereas shrimp chitosan scaffolds (MW 106Da and DA 12% exhibited the lowest water absorption properties and lysozyme degradation rate. In the evaluation of biocompatibility of chitosan scaffolds, the ability of fibroblast NIH/3T3 cells to attach on all chitosan scaffolds was similar, but the proliferation of cells with polygonal morphology was faster on crab, squid and fungal chitosan scaffolds than on shrimp chitosan scaffolds. Therefore fungal chitosan scaffold, which has excellent mechanical and biological properties, is the most suitable scaffold to use as a template for tissue regeneration.

  7. A Case Report of the First Nonburn-related Military Trauma Victim Treated with Spray Skin Regenerative Therapy in Combination with a Dermal Regenerate Template (United States)

    Hammer, Daniel A.; Rendon, Juan L.; Latham, Kerry P.; Fleming, Mark E.


    Summary: Massive soft tissue and skin loss secondary to war-related traumas are among the most frequently encountered challenges in the care of wounded warriors. This case report outlines the first military nonburn-related trauma patient treated by a combination of regenerative modalities. Our case employs spray skin technology to an established dermal regenerate matrix. Our patient, a 29-year-old active duty male, suffered a combat blast trauma in 2010 while deployed. The patient’s treatment course was complicated by a severe necrotizing fasciitis infection requiring over 100 surgical procedures for disease control and reconstruction. In secondary delayed reconstruction procedures, this triple-limb amputee underwent successful staged ventral hernia repair via a component separation technique with biologic mesh underlay although this resulted in a skin deficit of more than 600 cm2. A dermal regenerate template was applied to the abdominal wound to aid in establishing a “neodermis.” Three weeks after dermal regenerate application, spray skin was applied to the defect in conjunction with a 6:1 meshed split thickness skin graft. The dermal regenerate template allowed for optimization of the wound bed for skin grafting. The use of spray skin allowed for a 6:1 mesh ratio, thus minimizing the donor-site size and morbidity. Together, this approach resulted in complete healing of a large full-thickness wound. The patient is now able to perform activities of daily living, walk without a cane, and engage in various physical activities. Overall, our case highlights the potential that combining regenerative therapies can achieve in treating severe war-related and civilian traumatic injuries. PMID:28293522

  8. Bioprosthetic mitral valve thrombosis complicating antiphospholipid antibody syndrome, successfully treated with thrombolysis. (United States)

    Chamsi-Pasha, Mohammed A; Alyousef, Tareq; Sayyed, Samer


    The incidence of bioprosthetic valve thrombosis and related embolic complications is extremely rare, obviating the need for long-term anticoagulation. As a result, experience in the diagnosis and treatment of bioprosthetic valve thrombosis is fairly limited. We report the first case of antiphospholipid antibody syndrome presenting as bioprosthetic mitral valve thrombosis, 15 months after valve replacement, and successfully treated with thrombolytic therapy.

  9. Degenerative processes in bioprosthetic mitral valves in juvenile pigs

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    Pedersen Torben B


    Full Text Available Abstract Background Glutaraldehyde-treated bioprosthetic heart valves are commonly used for replacement of diseased heart valves. However, calcification and wear limit their durability, and the development of new and improved bioprosthetic valve designs is needed and must be evaluated in a reliable animal model. We studied glutaraldehyde-treated valves 6 months after implantation to evaluate bioprosthetic valve complications in the mitral position in juvenile pigs. Materials The study material comprised eight, 5-month old, 60-kg pigs. All pigs received a size 27, glutaraldehyde-treated, stented, Carpentier-Edwards S.A.V. mitral valve prosthesis. After six months, echocardiography was performed, and the valves explanted for gross examination, high resolution X-ray, and histological evaluation. Results Five pigs survived the follow-up period. Preexplant echocardiography revealed a median peak and mean velocity of 1.61 m/s (range: 1.17-2.00 and 1.20 (SD = ±0.25, respectively, and a median peak and mean pressure difference of 10.42 mmHg (range: 5.83-16.55 and 6.51 mmHg (SD = ±2.57, respectively. Gross examination showed minor thrombotic depositions at two commissures in two valves and at all three commissures in three valves. High resolution X-ray imaging revealed different degrees of calcification in all explanted valves, primarily in the commissural and belly areas. In all valves, histological evaluation demonstrated various degrees of fibrous sheath formation, limited immunological infiltration, and no overgrowth of host endothelium. Conclusions Bioprosthetic glutaraldehyde-treated mitral valves can be implanted into the mitral position in pigs and function after 6 months. Echocardiographic data, calcification, and histological examinations were comparable to results obtained in sheep models and human demonstrating the suitability of the porcine model.

  10. In Vitro Evaluation of a Biomedical-Grade Bilayer Chitosan Porous Skin Regenerating Template as a Potential Dermal Scaffold in Skin Tissue Engineering

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    Chin Keong Lim


    Full Text Available Chitosan is a copolymer of N-acetylglucosamine and glucosamine. A bilayer chitosan porous skin regenerating template (CPSRT has been developed for skin tissue engineering. The pore size of the CPSRT was assessed using a scanning electron microscopy (SEM. The in vitro cytocompatibility of the CPSRT was tested on primary human epidermal keratinocyte (pHEK cultures by measuring lactate dehydrogenase (LDH levels and skin irritation by western blot analysis of the interleukin-8 (IL-8 and tumor necrosis factor-α (TNF-α secretions. The ability of the CPSRT to support cell ingrowth was evaluated by seeding primary human dermal fibroblasts (pHDFs on the scaffold, staining the cells with live/dead stain, and imaging the construct by confocal microscopy (CLSM. The CPSRT with pore sizes ranging from 50 to 150 μm was cytocompatible because it did not provoke the additional production of IL-8 and TNF-α by pHEK cultures. Cultured pHDFs were able to penetrate the CPSRT and had increased in number on day 14. In conclusion, the CPSRT serves as an ideal template for skin tissue engineering.

  11. Cardiac crossroads: deciding between mechanical or bioprosthetic heart valve replacement

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    Maggie N Tillquist


    Full Text Available Maggie N Tillquist1, Thomas M Maddox21School of Medicine, University of Colorado Denver, Denver, CO, USA; 2VA Eastern Colorado Health Care System, and Department of Medicine (Cardiology, University of Colorado Denver, Denver, CO, USAAbstract: Nearly 15 million people in the United States suffer from either aortic or mitral valvular disease. For patients with severe and symptomatic valvular heart disease, valve replacement surgery improves morbidity and mortality outcomes. In 2009, 90,000 valve replacement surgeries were performed in the United States. This review evaluates the advantages and disadvantages of mechanical and bioprosthetic prosthetic heart valves as well as the factors for consideration in deciding the appropriate valve type for an individual patient. Although many caveats exist, the general recommendation is for patients younger than 60 to 65 years to receive mechanical valves due to the valve's longer durability and for patients older than 60 to 65 years to receive a bioprosthetic valve to avoid complications with anticoagulants. Situations that warrant special consideration include patient co-morbidities, the need for anticoagulation, and the potential for pregnancy. Once these characteristics have been considered, patients' values, anxieties, and expectations for their lifestyle and quality of life should be incorporated into final valve selection. Decision aids can be useful in integrating preferences in the valve decision. Finally, future directions in valve technology, anticoagulation, and medical decision-making are discussed.Keywords: prosthetic heart valves, patient preference, valve type, anticoagulant, structural valve deterioration 

  12. Regenerated cellulose membrane as bio-template for in-situ growth of visible-light driven C-modified mesoporous titania. (United States)

    Mohamed, Mohamad Azuwa; W Salleh, W N; Jaafar, Juhana; Mohd Hir, Zul Adlan; Rosmi, Mohamad Saufi; Abd Mutalib, Muhazri; Ismail, Ahmad Fauzi; Tanemura, Masaki


    Visible light driven C-doped mesoporous TiO2 (C-MTiO2) nanorods have been successfully synthesized through green, low cost, and facile approach by sol-gel bio-templating method using regenerated cellulose membrane (RCM) as nanoreactor. In this study, RCM was also responsible to provide in-situ carbon sources for resultant C-MTiO2 nanorods in acidified sol at low temperatures. The composition, crystallinity, surface area, morphological structure, and optical properties of C-MTiO2 nanorods, respectively, had been characterized using FTIR, XRD, N2 adsorption/desorption, TEM, UV-vis-NIR, and XPS spectroscopy. The results suggested that the growth of C-MTiO2 nanorods was promoted by the strong interaction between the hydroxyl groups of RCMs and titanium ion. Optical and XPS analysis confirmed that carbon presence in TiO2 nanorods were responsible for band-gap narrowing, which improved the visible light absorption capability. Photocatalytic activity measurements exhibited the capability of C-MTiO2 nanorods in degradation of methyl orange in aqueous solution, with 96.6% degradation percentage under visible light irradiation.

  13. Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves

    DEFF Research Database (Denmark)

    Makkar, Raj R; Fontana, Gregory; Jilaihawi, Hasan


    -rendered CT scans along with data on anticoagulation and clinical outcomes (including strokes and transient ischemic attacks [TIAs]). RESULTS: Reduced leaflet motion was noted on CT in 22 of 55 patients (40%) in the clinical trial and in 17 of 132 patients (13%) in the two registries. Reduced leaflet motion...... patients and 1 of 115 patients, respectively; P=0.007). CONCLUSIONS: Reduced aortic-valve leaflet motion was shown in patients with bioprosthetic aortic valves. The condition resolved with therapeutic anticoagulation. The effect of this finding on clinical outcomes including stroke needs further......BACKGROUND: A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis...

  14. Transcatheter Aortic Valve Replacement in a Patient With a Previous Bioprosthetic Mitral Valve Replacement: Report of a Delayed Fatal Interaction. (United States)

    Poulin, Frédéric; Lamarche, Yoan; Le, Van Hoai Viet; Doucet, Michel; Roméo, Philippe; Généreux, Philippe


    We report on a man with bioprosthetic mitral valve perforation who presented late after transcatheter aortic valve replacement with a balloon-expandable transcatheter heart valve (THV). The protrusion of the commissural strut of the bioprosthetic mitral valve coupled with the low implanted THV resulted in repetitive trauma leading to rupture of a mitral leaflet. Potential preventive strategies are discussed. This case illustrates the importance of preprocedural imaging screening and cautious THV deployment in patients with a bioprosthetic mitral valve.

  15. Design of Bioprosthetic Aortic Valves using biaxial test data. (United States)

    Dabiri, Y; Paulson, K; Tyberg, J; Ronsky, J; Ali, I; Di Martino, E; Narine, K


    Bioprosthetic Aortic Valves (BAVs) do not have the serious limitations of mechanical aortic valves in terms of thrombosis. However, the lifetime of BAVs is too short, often requiring repeated surgeries. The lifetime of BAVs might be improved by using computer simulations of the structural behavior of the leaflets. The goal of this study was to develop a numerical model applicable to the optimization of durability of BAVs. The constitutive equations were derived using biaxial tensile tests. Using a Fung model, stress and strain data were computed from biaxial test data. SolidWorks was used to develop the geometry of the leaflets, and ABAQUS finite element software package was used for finite element calculations. Results showed the model is consistent with experimental observations. Reaction forces computed by the model corresponded with experimental measurements when the biaxial test was simulated. As well, the location of maximum stresses corresponded to the locations of frequent tearing of BAV leaflets. Results suggest that BAV design can be optimized with respect to durability.

  16. Quantification of the edge effect in calcified bioprosthetic tissues. (United States)

    Wika, K E; Utoh, J; Brown, J; Harasaki, H


    In bioprosthetic tissue samples that had been implanted in the subcutaneous space of rats, and recurring pattern of calcification was observed. In this pattern, which we call the edge effect, the interior of the tissue is calcified and is surrounded and separated from the subcutaneous fluid by a zone that is free from calcification. The edge effect has been qualitatively described in the literature for subcutaneous implants and for valve leaflets, and it may be related to the mechanism of calcification for these materials. The thickness of the calcification free outer layer was quantified for glutaraldehyde treated bovine pericardium, glycerol treated bovine pericardium, glutaraldehyde treated human dura mater, and glycerol treated human dura mater. The edge effect values were found to be unique and consistent for each material type, and they were inversely related to the shrinkage temperatures and the calcium contents of the materials. It was determined that the chemical treatment was more important than the tissue type in determining the edge effect value.

  17. Donkey pericardium as an alternative bioprosthetic heart valve material. (United States)

    Chen, Shanliang; Xu, Li; Liu, Yuxi; Li, Quan; Wang, Dong; Wang, Xuemei; Liu, Tianqi


    This study comparatively evaluates the characteristics of glutaraldehyde-treated acellular bovine and donkey pericardium using histological and electronic microscopic observation techniques, shrinkage temperature, and mechanical properties, as well as determining calcium and phosphorus content at 4 and 8 weeks after the subcutaneous implantation of donkey and bovine pericardium in Wistar rats. Donkey pericardium was significantly thinner compared with bovine pericardium (1.622 ±  0.161 mm vs. 4.027 ± 0.401 mm, P donkey pericardium was similar to that of bovine pericardium (87.43 ± 0.55°C vs. 87.50 ± 0.36°C, P =  0.810). No differences between groups were observed for maximum load (donkey: 21.64 ± 7.02 KN/m vs. bovine: 15.05 ± 4.50 KN/m, P = 0.082) and tear strength (donkey: 11.54 ± 5.33 MPa vs. bovine: 10.69 ±  3.77 MPa, P = 0.757). Calcium content was significantly lower in donkey pericardium compared with bovine pericardium at 4 weeks (690.15 ± 191.27 µg/g vs. 1381.73 ± 62.52 µg/g, P = 0.001) and 8 weeks (205.24 ± 62.40 µg/g vs. 910.48 ± 398.29 µg/g, P = 0.037). This preliminary study has confirmed that glutaraldehyde-tanned donkey pericardium, demonstrating reduced calcification and increased tensile strength, may provide a suitable bioprosthetic valve substitute.

  18. [Study of cytotoxicity of bioprosthetic heart valve material and its store solution]. (United States)

    Cheng, S; Shi, Y; Liang, W; Li, W


    This study compared the cytotoxicities of bioprosthetic heart valve materials crosslinked by glutaraldehyde, stored in 4% formaldehyde or Hank's solution. Human embryonic pulmonary fibroblasts or L-929 cell culture in vitro were used. Cell proliferative inhibition index(CP II) was calculated for bioprosthetic heart valve materials using different store methods in different rinse periods(before, 10 days, 20 days, 30 days). The results demonstrate: (1) bioprosthetic heart valve materials stored in 4% formaldehyde or in Hank's solution both have significant cytotoxicity, and the longer the rinse time continues, the lower the cytotoxicity declines; (2) HEL cell is more sensitive than L-929 cell in detecting the cytotoxicity of toxic biomaterials but for weak toxic biomaterials the two cell lines are not significanth different; (3) formatldehyde solution increases the cytotoxicity of biomaterials stored in it, but the enhanced cytotoxicity can be easily relieved by rinse. The authors conclude that bioprosthetic heart valve materials have long term significant cytotoxicity and the biomaterial cytotoxicity test using human fibroblasts is more sensitive and precise than other tests.

  19. Uso del regenerador dérmico Integra® como material de relleno para el tratamiento de defectos del contorno corporal Use of Integra® dermal regeneration template in deep tissue planes for contour defects treatment

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    P. A. Gómez Morell


    Full Text Available En el tratamiento de los defectos de contorno corporal se usan múltiples productos biológicos y/o sintéticos. Cuando el volumen no es grande, los autores plantean el uso del regenerador dérmico Integra® eliminando previamente su capa superficial de silicona frente a los inconvenientes que presenta el uso de otros materiales de relleno en Cirugía Plástica (reabsorción variable, intolerancia, infección, granulomas, calcificación, etc. Dicho producto acaba transformándose en neodermis del propio paciente, bien tolerada. Presentamos dos casos con defectos a nivel frontal (postraumático y en tórax anterior (secuelas de reconstrucción tras mastectomía respectivamente, en los que se colocó Integra® en bolsillos profundos y doblado sobre sí mismo para aumentar su volumen. Los resultados son previsibles, con mínima reabsorción y además son duraderos, con seguimiento a los 6 y 12 meses. Los autores recomiendan el uso del regenerador dérmico en volúmenes moderados y/o pequeños, considerando que en grandes volúmenes es preferible el uso del colgajos autólogos y/o colgajos más prótesis.In the treatment of body contour defects we can use many biological and synthetic products. They have many inconvenient effects as variable reabsortion, intolerance, infection, granulomas, calcification, etc. In moderate defects, the authors propose the use of modificated Integra® dermal regeneration template without the superficial silicone layer. Two patients are reported, one with a traumatic frontal defect and another with a depression in the anterior thorax after postmastectomy breast reconstruction post mastectomy. In both we put Integra® into a subcutaneous pocket and we bent it to increase lamina volume. Results are predictable, permanent, with minimal reabsortion after 6 and 12 months follow up. Integra® will be autologous neodermis. The authors recommend the dermal regeneration template for small or medium defects; in large defects they

  20. Diagnosis and treatment of early bioprosthetic malfunction in the mitral valve position due to thrombus formation. (United States)

    Butnaru, Adi; Shaheen, Joseph; Tzivoni, Dan; Tauber, Rachel; Bitran, Daniel; Silberman, Shuli


    Bioprosthetic valve thrombosis is uncommon and the diagnosis is often elusive and may be confused with valve degeneration. We report our experience with mitral bioprosthetic valve thrombosis and suggest a therapeutic approach. From 2002 to 2011, 149 consecutive patients who underwent mitral valve replacement with a bioprosthesis at a single center were retrospectively screened for clinical or echocardiographic evidence of valve malfunction. Nine were found to have valve thrombus. All 9 patients had their native valve preserved, representing 24% of those with preserved native valves. Five patients (group 1) presented with symptoms of congestive heart failure at 16.4 ± 12.4 months after surgery. Echocardiogram revealed homogenous echo-dense film on the ventricular surface of the bioprosthesis with elevated transvalvular gradient, resembling early degeneration. The first 2 patients underwent reoperation: valve thrombus was found and confirmed by histologic examination. Based on these, the subsequent 3 patients received anticoagulation treatment with complete thrombus resolution: mean mitral gradient decreased from 23 ± 4 to 6 ± 1 mm Hg and tricuspid regurgitation gradient decreased from 83 ± 20 to 49 ± 5 mm Hg. Four patients (group 2) were asymptomatic, but routine echocardiogram showed a discrete mass on the ventricular aspect of the valve: 1 underwent reoperation to replace the valve and 3 received anticoagulation with complete resolution of the echocardiographic findings. In conclusion, bioprosthetic mitral thrombosis occurs in about 6% of cases. In our experience, onset is early, before anticipated valve degeneration. Clinical awareness followed by an initial trial with anticoagulation is warranted. Surgery should be reserved for those who are not responsive or patients in whom the hemodynamic status does not allow delay. Nonresection of the native valve at the initial operation may play a role in the origin of this entity.

  1. Mitral bioprosthetic valve stenosis in a patient with antiphospholipid antibody syndrome and systemic lupus erythematosus. (United States)

    Morisaki, Akimasa; Hirai, Hidekazu; Sasaki, Yasuyuki; Hosono, Mitsuharu; Sakaguchi, Masanori; Nakahira, Atsushi; Seo, Hiroyuki; Suehiro, Shigefumi


    A 45-year-old woman with antiphospholipid antibody syndrome (APS) and systemic lupus erythematosus was admitted because of severe dyspnea. She had undergone mitral valve replacement (MVR) using a Mosaic bioprosthesis for infective endocarditis 9 years previously. She developed congestive heart failure secondary to mitral bioprosthetic valve stenosis resulting from relatively early structural valve deterioration. She underwent a second MVR using a mechanical valve prosthesis. The explanted bioprosthesis showed marked pannus formation and mineralization with fibrin thrombus formation, especially on the outflow surfaces of the leaflets. After the second operation, she was discharged without APS-related thromboembolic events under meticulous anticoagulant and antiplatelet therapies.

  2. Neomycin and carbodiimide crosslinking as an alternative to glutaraldehyde for enhanced durability of bioprosthetic heart valves. (United States)

    Leong, Joshua; Munnelly, Amy; Liberio, Brianna; Cochrane, Leonard; Vyavahare, Naren


    Glutaraldehyde cross-linked porcine aortic valves, referred to as bioprosthetic heart valves (BHVs), are often used in heart valve replacements. Glutaraldehyde does not stabilize glycosaminoglycans (GAGs) and they are lost during preparation, in vivo implantation, cyclic fatigue, and storage. We report that binding of neomycin, a hyaluronidase inhibitor, to the tissues with carbodiimide cross-linking improves GAG retention without reducing collagen and elastin stability. It also led to improved biomechanical properties. Neomycin carbodiimide cross-linking did not significantly reduce calcification in a rat subdermal implantation model when they were stored in formaldehyde after cross-linking. Removal of formaldehyde storage significantly reduced calcification.

  3. Antiphospholipid Syndrome and Libman-Sacks Endocarditis in a Bioprosthetic Mitral Valve. (United States)

    Sladek, Eric H; Accola, Kevin D


    This report describes one the first cases of antiphospholipid syndrome and Libman-Sacks endocarditis in a bioprosthetic valve. A redo mitral valve replacement was carried out owing to early deterioration of the prior valve. Initially it was considered secondary to rheumatic heart disease; however, pathology analysis and autoimmune workup revealed antiphospholipid syndrome with Libman-Sacks endocarditis. We believe certain populations with mitral valve stenosis may have an underlying antiphospholipid syndrome. As a result, there needs to be a lower threshold for identifying this disease.

  4. Severe Bioprosthetic Mitral Valve Stenosis and Heart Failure in a Young Woman with Systemic Lupus Erythematosus

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    Siddharth Wartak


    Full Text Available A 23-year-old African American woman with a past medical history of systemic lupus erythematous (SLE, secondary hypertension, and end stage renal disease (ESRD on hemodialysis for eight years was stable until she developed symptomatic severe mitral regurgitation with preserved ejection fraction. She underwent a bioprosthetic mitral valve replacement (MVR at outside hospital. However, within a year of her surgery, she presented to our hospital with NYHA class IV symptoms. She was treated for heart failure but in view of her persistent symptoms and low EF was considered for heart and kidney transplant. This was a challenge in view of her history of lupus. We presumed that her stenosis of bioprosthetic valve was secondary to lupus and renal disease. We hypothesized that her low ejection fraction was secondary to mitral stenosis and potentially reversible. We performed a dobutamine stress echocardiogram, which revealed an improved ejection fraction to more than 50% and confirmed preserved inotropic contractile reserve of her myocardium. Based on this finding, she underwent a metallic mitral valve and tricuspid valve replacement. Following surgery, her symptoms completely resolved. This case highlights the pathophysiology of lupus causing stenosis of prosthetic valves and low ejection cardiomyopathy.

  5. Carpentier-Edwards aortic pericardial bioprosthetic valve as a valid control in preclinical in vivo ovine studies. (United States)

    Harvey, Laura; Bianco, Richard; Lahti, Matthew; Carney, John; Zhang, Lindsey; Robinson, Nicholas


    To progress into clinical practice, a bioprosthetic heart valve must first pass through the preclinical evaluation phase. The International Standards Organization (ISO) recommends implantation of concurrent controls in any evaluation of a new or modified heart valve. A total of 8 adult sheep underwent aortic valve replacement, receiving either the CE Perimount Magna 3000 aortic pericardial bioprosthetic valve or the CE Perimount RSR aortic pericardial bioprosthetic valve, Model 2800. We performed serial blood sampling, echocardiography, angiography and necropsy after euthanasia. All 8 sheep survived until the end of their study term. Our 2-dimensional echocardiographic analysis showed a mean pressure gradient of 37.4±6.0mmHg at 14 days and 37.0±5.9mmHg at 90 days; mean cardiac output was 10.0±2.8l/min at 14 days and 9.6±1.6l/min at 90 days. Angiography before euthanasia showed a mean aortic transvalvular gradient of 32.3±15.3mmHg. At euthanasia, we saw no evidence of calcification in any of the valves. In our study, we found that both models of the CE bioprosthetic heart valve we tested proved to be valid controls, in the aortic position, in sheep-with no evidence of calcification. Most important, the valves we tested had a few model-related problems, allowing a clear determination of their suitability for introduction into a clinical trial. Investigators now have additional insight into the safety of these 2 models of valves and perhaps will be able to reduce the number of controls implanted.

  6. Neomycin binding preserves extracellular matrix in bioprosthetic heart valves during in vitro cyclic fatigue and storage. (United States)

    Raghavan, Devanathan; Starcher, Barry C; Vyavahare, Naren R


    Bioprosthetic heart valve (BHV) cusps have a complex architecture consisting of an anisotropic arrangement of collagen, glycosaminoglycans (GAGs) and elastin. Glutaraldehyde (GLUT) is used as a fixative for all clinical BHV implants; however, it only stabilizes the collagen component of the tissue, and other components such as GAGs and elastin are lost from the tissue during processing, storage or after implantation. We have shown previously that the effectiveness of the chemical crosslinking can be increased by incorporating neomycin trisulfate, a hyaluronidase inhibitor, to prevent the enzyme-mediated GAG degradation. In the present study, we optimized carbodiimide-based GAG-targeted chemistry to incorporate neomycin into BHV cusps prior to conventional GLUT crosslinking. This crosslinking leads to enhanced preservation of GAGs during in vitro cyclic fatigue and storage. The neomycin group showed greater GAG retention after both 10 and 50 million accelerated fatigue cycles and after 1 year of storage in GLUT solution. Thus, additional binding of neomycin to the cusps prior to standard GLUT crosslinking could enhance tissue stability and thus heart valve durability.

  7. Evaluation of bioprosthetic heart valve failure using a matrix-fibril shear stress transfer approach. (United States)

    Anssari-Benam, Afshin; Barber, Asa H; Bucchi, Andrea


    A matrix-fibril shear stress transfer approach is devised and developed in this paper to analyse the primary biomechanical factors which initiate the structural degeneration of the bioprosthetic heart valves (BHVs). Using this approach, the critical length of the collagen fibrils l c and the interface shear acting on the fibrils in both BHV and natural aortic valve (AV) tissues under physiological loading conditions are calculated and presented. It is shown that the required critical fibril length to provide effective reinforcement to the natural AV and the BHV tissue is l c  = 25.36 µm and l c  = 66.81 µm, respectively. Furthermore, the magnitude of the required shear force acting on fibril interface to break a cross-linked fibril in the BHV tissue is shown to be 38 µN, while the required interfacial force to break the bonds between the fibril and the surrounding extracellular matrix is 31 µN. Direct correlations are underpinned between these values and the ultimate failure strength and the failure mode of the BHV tissue compared with the natural AV, and are verified against the existing experimental data. The analyses presented in this paper explain the role of fibril interface shear and critical length in regulating the biomechanics of the structural failure of the BHVs, for the first time. This insight facilitates further understanding into the underlying causes of the structural degeneration of the BHVs in vivo.

  8. New treatments using alginate in order to reduce the calcification of bovine bioprosthetic heart valve tissue. (United States)

    Shanthi, C; Rao, K P


    Calcification limits the functional lifetime of cardiac valve substitutes fabricated from glutaraldehyde preserved bovine pericardium. Host factors, mainly younger age, and implant factors, mainly glutaraldehyde cross-linking, are implicated in the calcification process. Glutaraldehyde cross-linking is believed to activate the potential sites in the tissues for biocalcification. In the present work, we investigated the possibility of using alginate azide (AA) instead of glutaraldehyde for the preservation of pericardial tissues in order to enhance the durability of bioprosthetic heart valves. Grafting with poly(GMA-BA) copolymer to the alginate azide cross-linked pericardial (AACPC) tissue was carried out to obtain better stability, strength, and anticalcification properties. The strength property and thermal stability of the AA cross-linked tissues were studied. Calcification studies in rat subdermal models reveal that AA cross-linking reduces the calcification to negligible levels. After 30 days implantation, the calcium content was found to be 10.4 +/- 1.2 and 6.1 +/- 0.3 micrograms mg-1 for untreated AACPC and polymer grafted AACPC, respectively, compared to a value of 100 +/- 1.2 micrograms mg-1 calcium recorded for control glutaraldehyde cross-linked pericardial (GCPC) tissues.

  9. Effects of Leaflet Design on Transvalvular Gradients of Bioprosthetic Heart Valves. (United States)

    Dabiri, Yaghoub; Ronsky, Janet; Ali, Imtiaz; Basha, Ameen; Bhanji, Alisha; Narine, Kishan


    Bioprosthetic aortic valves (BAVs) are becoming the prostheses of choice in heart valve replacement. The objective of this paper is to assess the effects of leaflet geometry on the mechanics and hemodynamics of BAVs in a fluid structure interaction model. The curvature and angle of leaflets were varied in 10 case studies whereby the following design parameters were altered: a circular arch, a line, and a parabola for the radial curvature, and a circular arch, a spline, and a parabola for the circumferential curvature. Six different leaflet angles (representative of the inclination of the leaflets toward the surrounding aortic wall) were analyzed. The 3-dimensional geometry of the models were created using SolidWorks, Pointwise was used for meshing, and Comsol Multiphysics was used for implicit finite element calculations. Realistic loading was enforced by considering the time-dependent strongly-coupled interaction between blood flow and leaflets. Higher mean pressure gradients as well as von Mises stresses were obtained with a parabolic or circular curvature for radial curvature or a parabolic or spline curvature for the circumferential curvature. A smaller leaflet angle was associated with a lower pressure gradient, and, a lower von Mises stress. The leaflet curvature and angle noticeably affected the speed of valve opening, and closing. When a parabola was used for circumferential or radial curvature, leaflets displacements were asymmetric, and they opened and closed more slowly. A circular circumferential leaflet curvature, a linear leaflet radial curvature, and leaflet inclination toward the surrounding aortic wall were associated with superior BAVs mechanics.

  10. Code Generation with Templates

    CERN Document Server

    Arnoldus, Jeroen; Serebrenik, A


    Templates are used to generate all kinds of text, including computer code. The last decade, the use of templates gained a lot of popularity due to the increase of dynamic web applications. Templates are a tool for programmers, and implementations of template engines are most times based on practical experience rather than based on a theoretical background. This book reveals the mathematical background of templates and shows interesting findings for improving the practical use of templates. First, a framework to determine the necessary computational power for the template metalanguage is presen

  11. Neomycin and pentagalloyl glucose enhanced cross-linking for elastin and glycosaminoglycans preservation in bioprosthetic heart valves. (United States)

    Tripi, Daniel R; Vyavahare, Naren R


    Glutaraldehyde cross-linked bioprosthetic heart valves fail within 12-15 years of implantation due to limited durability. Glutaraldehyde does not adequately stabilize extracellular matrix components such as glycosaminoglycans and elastin, and loss of these components could be a major cause of degeneration of valve after implantation. We have shown earlier that neomycin-based cross-linking stabilizes glycosaminoglycans in the tissue but fails to stabilize elastin component. Here, we report a new treatment where neomycin and pentagalloyl glucose (PGG) were incorporated into glutaraldehyde cross-linking neomycin-PGG-Glutaraldehyde (NPG) to stabilize both glycosaminoglycans and elastin in porcine aortic valves. In vitro studies demonstrated a marked increase in extracellular matrix stability against enzymatic degradation after cross-linking and 10 month storage in NPG group when compared to glutaraldehyde controls. Tensile properties showed increased lower elastic modulus in both radial and circumferential directions in NPG group as compared to glutaraldehyde, probably due to increased elastin stabilization with no changes in upper elastic modulus and extensibility. The enhanced extracellular matrix stability was further maintained in NPG-treated tissues after rat subdermal implantation for three weeks. NPG group also showed reduced calcification when compared to glutaraldehyde controls. We conclude that NPG cross-linking would be an excellent alternative to glutaraldehyde cross-linking of bioprosthetic heart valves to improve its durability.

  12. Impact of recipient-related factors on structural dysfunction of xenoaortic bioprosthetic heart valves

    Directory of Open Access Journals (Sweden)

    Barbarash O


    Full Text Available Olga Barbarash, Natalya Rutkovskaya, Oksana Hryachkova, Olga Gruzdeva, Evgenya Uchasova, Anastasia Ponasenko, Natalya Kondyukova, Yuri Odarenko, Leonid Barbarash Federal State Budgetary Scientific Institution Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia Objective: To analyze the influence of recipient-related metabolic factors on the rate of structural dysfunction caused by the calcification of xenoaortic bioprostheses. Materials and methods: We retrospectively analyzed clinical status, calcium–phosphorus metabolism, and nonspecific markers of inflammatory response in bioprosthetic mitral valve recipients with calcific degeneration confirmed by histological and electron microscopic studies (group 1, n=22, and in those without degeneration (group 2, n=48. Results: Patients with confirmed calcification of bioprostheses were more likely to have a severe clinical state (functional class IV in 36% in group 1 versus 15% in group 2, P=0.03 and a longer cardiopulmonary bypass period (112.8±18.8 minutes in group 1 versus 97.2±23.6 minutes in group 2, P=0.02 during primary surgery. Patients in group 1 demonstrated moderate hypovitaminosis D (median 34.0, interquartile range [21.0; 49.4] vs 40 [27.2; 54.0] pmol/L, P>0.05, osteoprotegerin deficiency (82.5 [44.2; 115.4] vs 113.5 [65.7; 191.3] pg/mL, P>0.05 and osteopontin deficiency (4.5 [3.3; 7.7] vs 5.2 [4.1; 7.2] ng/mL, P>0.05, and significantly reduced bone-specific alkaline phosphatase isoenzyme (17.1 [12.2; 21.4] vs 22.3 [15.5; 30.5] U/L, P=0.01 and interleukin-8 levels (9.74 [9.19; 10.09] pg/mL vs 13.17 [9.72; 23.1] pg/mL, P=0.045 compared with group 2, with an overall increase in serum levels of proinflammatory markers. Conclusion: Possible predictors of the rate of calcific degeneration of bioprostheses include the degree of decompensated heart failure, the duration and invasiveness of surgery, and the characteristics of calcium–phosphorus homeostasis in

  13. Liver regeneration. (United States)

    Mao, Shennen A; Glorioso, Jaime M; Nyberg, Scott L


    The liver is unique in its ability to regenerate in response to injury. A number of evolutionary safeguards have allowed the liver to continue to perform its complex functions despite significant injury. Increased understanding of the regenerative process has significant benefit in the treatment of liver failure. Furthermore, understanding of liver regeneration may shed light on the development of cancer within the cirrhotic liver. This review provides an overview of the models of study currently used in liver regeneration, the molecular basis of liver regeneration, and the role of liver progenitor cells in regeneration of the liver. Specific focus is placed on clinical applications of current knowledge in liver regeneration, including small-for-size liver transplant. Furthermore, cutting-edge topics in liver regeneration, including in vivo animal models for xenogeneic human hepatocyte expansion and the use of decellularized liver matrices as a 3-dimensional scaffold for liver repopulation, are proposed. Unfortunately, despite 50 years of intense study, many gaps remain in the scientific understanding of liver regeneration.

  14. Templating mesoporous zeolites

    DEFF Research Database (Denmark)

    Egeblad, Kresten; Christensen, Christina Hviid; Kustova, Marina


    The application of templating methods to produce zeolite materials with hierarchical bi- or trimodal pore size distributions is reviewed with emphasis on mesoporous materials. Hierarchical zeolite materials are categorized into three distinctly different types of materials: hierarchical zeolite...... crystals, nanosized zeolite crystals, and supported zeolite crystals. For the pure zeolite materials in the first two categories, the additional meso- or macroporosity can be classified as being either intracrystalline or intercrystalline, whereas for supported zeolite materials, the additional porosity...... originates almost exclusively from the support material. The methods for introducing mesopores into zeolite materials are discussed and categorized. In general, mesopores can be templated in zeolite materials by use of solid templating, supramolecular templating, or indirect templating...

  15. images_template (United States)

    National Aeronautics and Space Administration — Images for the website template go here. It will not change their names or locations, but will hopefully help to organize them. Oh, but for a directory structure...

  16. The Trouble With Templates

    CERN Document Server

    Sampson, Laura; Yunes, Nicolas


    Waveform templates are a powerful tool for extracting and characterizing gravitational wave signals, acting as highly restrictive priors on the signal morphologies that allow us to extract weak events buried deep in the instrumental noise. The templates map the waveform shapes to physical parameters, thus allowing us to produce posterior probability distributions for these parameters. However, there are attendant dangers in using highly restrictive signal priors. If strong field gravity is not accurately described by General Relativity (GR), then using GR templates may result in fundamental bias in the recovered parameters, or even worse, a complete failure to detect signals. Here we study such dangers, concentrating on three distinct possibilities. First, we show that there exist modified theories compatible with all existing tests that would fail to be detected by the LIGO/Virgo network using searches based on GR templates, but which would be detected using a one parameter post-Einsteinian extension. Second...

  17. Neomycin fixation followed by ethanol pretreatment leads to reduced buckling and inhibition of calcification in bioprosthetic valves. (United States)

    Raghavan, Devanathan; Shah, Sagar R; Vyavahare, Naren R


    Glutaraldehyde crosslinked bioprosthetic heart valves (BHVs) have two modalities of failure: degeneration (cuspal tear due to matrix failure) and calcification. They can occur independently as well as one can lead to the other causing co-existence. Calcific failure has been extensively studied before and several anti-calcification treatments have been developed; however, little research is directed to understand mechanisms of valvular degeneration. One of the shortcomings of glutaraldehyde fixation is its inability to stabilize all extracellular matrix components in the tissue. Previous studies from our lab have demonstrated that neomycin could be used as a fixative to stabilize glycosaminoglycans (GAGs) present in the valve to improve matrix properties. But neomycin fixation did not prevent cuspal calcification. In the present study, we wanted to enhance the anti-calcification potential of neomycin fixed valves by pre-treating with ethanol or removing the free aldehydes by sodium borohydride treatment. Ethanol treatment has been previously used and found to have excellent anti-calcification properties for valve cusps. Results demonstrated in this study suggest that neomycin followed by ethanol treatment effectively preserves GAGs both in vitro as well as in vivo after subdermal implantation in rats. In vivo calcification was inhibited in neomycin fixed cusps pretreated with ethanol compared to glutaraldehyde (GLUT) control. Sodium borohydride treatment by itself did not inhibit calcification nor stabilized GAGs against enzymatic degradation. Neomycin fixation followed by ethanol treatment of BHVs could prevent both modalities of failure, thereby increasing the effective durability and lifetime of these bioprostheses several fold.

  18. Joomla! 3 template essentials

    CERN Document Server

    Frankowski, Pawel


    Using this hands-on, step-by step tutorial filled with practical examples, the readers will be able to create beautiful templates and themes for your websites that will make them stand out from others.This book is written for all of you who wish to create your own unique templates for Joomla! 3.x. This book can be used by Joomla! administrators or visual designers (with no programming experience) or those of you who are used to working with common web developer tools like HTML/CSS editors for coding purposes. You would need basic knowledge of Joomla! and some knowledge of CSS and HTML.

  19. Computing layouts with deformable templates

    KAUST Repository

    Peng, Chihan


    In this paper, we tackle the problem of tiling a domain with a set of deformable templates. A valid solution to this problem completely covers the domain with templates such that the templates do not overlap. We generalize existing specialized solutions and formulate a general layout problem by modeling important constraints and admissible template deformations. Our main idea is to break the layout algorithm into two steps: a discrete step to lay out the approximate template positions and a continuous step to refine the template shapes. Our approach is suitable for a large class of applications, including floorplans, urban layouts, and arts and design. Copyright © ACM.

  20. Periodontal regeneration. (United States)

    Ivanovski, S


    The ultimate goal of periodontal therapy is the regeneration of the tissues destroyed as a result of periodontal disease. Currently, two clinical techniques, based on the principles of "guided tissue regeneration" (GTR) or utilization of the biologically active agent "enamel matrix derivative" (EMD), can be used for the regeneration of intrabony and Class II mandibular furcation periodontal defects. In cases where additional support and space-making requirements are necessary, both of these procedures can be combined with a bone replacement graft. There is no evidence that the combined use of GTR and EMD results in superior clinical results compared to the use of each material in isolation. Great variability in clinical outcomes has been reported in relation to the use of both EMD and GTR, and these procedures can be generally considered to be unpredictable. Careful case selection and treatment planning, including consideration of patient, tooth, site and surgical factors, is required in order to optimize the outcomes of treatment. There are limited data available for the clinical effectiveness of other biologically active molecules, such as growth factors and platelet concentrates, and although promising results have been reported, further clinical trials are required in order to confirm their effectiveness. Current active areas of research are centred on tissue engineering and gene therapy strategies which may result in more predictable regenerative outcomes in the future.

  1. Template Composite Dark Matter

    DEFF Research Database (Denmark)

    Drach, Vincent; Hietanen, Ari; Pica, Claudio


    We present a non perturbative study of SU(2) gauge theory with two fundamental Dirac flavours. We discuss how the model can be used as a template for composite Dark Matter (DM). We estimate one particular interaction of the DM candidate with the Standard Model : the interaction through photon...

  2. Biometric template revocation (United States)

    Arndt, Craig M.


    Biometric are a powerful technology for identifying humans both locally and at a distance. In order to perform identification or verification biometric systems capture an image of some biometric of a user or subject. The image is then converted mathematical to representation of the person call a template. Since we know that every human in the world is different each human will have different biometric images (different fingerprints, or faces, etc.). This is what makes biometrics useful for identification. However unlike a credit card number or a password to can be given to a person and later revoked if it is compromised and biometric is with the person for life. The problem then is to develop biometric templates witch can be easily revoked and reissued which are also unique to the user and can be easily used for identification and verification. In this paper we develop and present a method to generate a set of templates which are fully unique to the individual and also revocable. By using bases set compression algorithms in an n-dimensional orthogonal space we can represent a give biometric image in an infinite number of equally valued and unique ways. The verification and biometric matching system would be presented with a given template and revocation code. The code will then representing where in the sequence of n-dimensional vectors to start the recognition.

  3. In search of templates


    Gobet, F.; Jackson, S


    This paper explores, both wit This study reflects a recent shift towards the study of early stages of expert memory acquisition for chess positions. Over the course of fifteen sessions, two subjects who knew virtually nothing about the game of chess were trained to memorise positions. Increase in recall performance and chunk size was captured by power functions, confirming predictions made by the template theory (Gobet & Simon, 1996, 1998, 2000). The human data was compared to that of a compu...

  4. Regenerator seal (United States)

    Davis, Leonard C.; Pacala, Theodore; Sippel, George R.


    A method for manufacturing a hot side regenerator cross arm seal assembly having a thermally stablilized wear coating with a substantially flat wear surface thereon to seal between low pressure and high pressure passages to and from the hot inboard side of a rotary regenerator matrix includes the steps of forming a flat cross arm substrate member of high nickel alloy steel; fixedly securing the side edges of the substrate member to a holding fixture with a concave surface thereacross to maintain the substrate member to a slightly bent configuration on the fixture surface between the opposite ends of the substrate member to produce prestress therein; applying coating layers on the substrate member including a wear coating of plasma sprayed nickel oxide/calcium flouride material to define a wear surface of slightly concave form across the restrained substrate member between the free ends thereon; and thereafter subjecting the substrate member and the coating thereon to a heat treatment of F. for sixteen hours to produce heat stabilizing growth in the coating layers on the substrate member and to produce a thermally induced growth stress in the wear surface that substantially equalizes the prestress in the substrate whereby when the cross arm is removed from the fixture surface following the heat treatment step a wear face is formed on the cross arm assembly that will be substantially flat between the ends.

  5. A Deformable Template Model, with Special Reference to Elliptical Templates

    DEFF Research Database (Denmark)

    Hobolth, Asger; Pedersen, Jan; Jensen, Eva Bjørn Vedel


    This paper suggests a high-level continuous image model for planar star-shaped objects. Under this model, a planar object is a stochastic deformation of a star-shaped template. The residual process, describing the difference between the radius-vector function of the template and the object...

  6. Templated quasicrystalline molecular layers (United States)

    Smerdon, Joe; Young, Kirsty; Lowe, Michael; Hars, Sanger; Yadav, Thakur; Hesp, David; Dhanak, Vinod; Tsai, An-Pang; Sharma, Hem Raj; McGrath, Ronan


    Quasicrystals are materials with long range ordering but no periodicity. We report scanning tunneling microscopy (STM) observations of quasicrystalline molecular layers on five-fold quasicrystal surfaces. The molecules adopt positions and orientations on the surface consistent with the quasicrystalline ordering of the substrate. Carbon-60 adsorbs atop sufficiently-separated Fe atoms on icosahedral Al-Cu-Fe to form a unique quasicrystalline lattice whereas further C60 molecules decorate remaining surface Fe atoms in a quasi-degenerate fashion. Pentacene (Pn) adsorbs at tenfold-symmetric points around surface-bisected rhombic triacontahedral clusters in icosahedral Ag-In-Yb. These systems constitute the first demonstrations of quasicrystalline molecular ordering on a template. EPSRC EP/D05253X/1, EP/D071828/1, UK BIS.

  7. DNA-templated nanofabrication. (United States)

    Becerril, Héctor A; Woolley, Adam T


    Nanofabrication, or the organizational control over matter at the nanometre scale, is an intriguing scientific challenge requiring multidisciplinary tools for its solution. DNA is a biomolecule that can be combined with other nanometre-scale entities through chemical self-assembly to form a broad variety of nanomaterials. In this tutorial review we present the principles that allow DNA to interact with other chemical species, and describe the challenges and potential applications of DNA as a template for making both biological and inorganic features with nanometre resolution. As such, this report should be of interest to chemists, surface and materials scientists, biologists, and nanotechnologists, as well as others who seek to use DNA in nanofabrication.

  8. Template-synthesized opal hydrogels

    Institute of Scientific and Technical Information of China (English)

    LI Jun; JI Lijun; RONG Jianhua; YANG Zhenzhong


    Opal hydrogels could be synthesized with polymer inverse opal template. A pH responsive opal N-iso- propylacrylamide/acrylic acid copolymerized hydrogel was prepared as an example. The ordered structure and response to pH were investigated. Through the sol-gel process of tetrabutyl titanate, opal titania was obtained with the opal hydrogel template.

  9. Making Deformable Template Models Operational

    DEFF Research Database (Denmark)

    Fisker, Rune


    Deformable template models are a very popular and powerful tool within the field of image processing and computer vision. This thesis treats this type of models extensively with special focus on handling their common difficulties, i.e. model parameter selection, initialization and optimization...... published during the Ph.D. project. To put these articles into the general context of deformable template models and to pass on an overview of the deformable template model literature, the thesis starts with a compact survey of the deformable template model literature with special focus on representation....... A proper handling of the common difficulties is essential for making the models operational by a non-expert user, which is a requirement for intensifying and commercializing the use of deformable template models. The thesis is organized as a collection of the most important articles, which has been...

  10. Active magnetic regenerator (United States)

    Barclay, John A.; Steyert, William A.


    The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

  11. Cloning nanocrystal morphology with soft templates (United States)

    Thapa, Dev Kumar; Pandey, Anshu


    In most template directed preparative methods, while the template decides the nanostructure morphology, the structure of the template itself is a non-general outcome of its peculiar chemistry. Here we demonstrate a template mediated synthesis that overcomes this deficiency. This synthesis involves overgrowth of silica template onto a sacrificial nanocrystal. Such templates are used to copy the morphologies of gold nanorods. After template overgrowth, gold is removed and silver is regrown in the template cavity to produce a single crystal silver nanorod. This technique allows for duplicating existing nanocrystals, while also providing a quantifiable breakdown of the structure - shape interdependence.

  12. Templated Growth of Carbon Nanotubes (United States)

    Siochik Emilie J. (Inventor)


    A method of growing carbon nanotubes uses a synthesized mesoporous si lica template with approximately cylindrical pores being formed there in. The surfaces of the pores are coated with a carbon nanotube precu rsor, and the template with the surfaces of the pores so-coated is th en heated until the carbon nanotube precursor in each pore is convert ed to a carbon nanotube.

  13. Regeneration of periodontal tissues: guided tissue regeneration. (United States)

    Villar, Cristina C; Cochran, David L


    The concept that only fibroblasts from the periodontal ligament or undifferentiated mesenchymal cells have the potential to re-create the original periodontal attachment has been long recognized. Based on this concept, guided tissue regeneration has been applied with variable success to regenerate periodontal defects. Quantitative analysis of clinical outcomes after guided tissue regeneration suggests that this therapy is a successful and predictable procedure to treat narrow intrabony defects and class II mandibular furcations, but offers limited benefits in the treatment of other types of periodontal defects.

  14. Emerging rules for inducing organ regeneration. (United States)

    Yannas, Ioannis V


    We review the available evidence for regeneration of adult organs of very diverse nature and examine the applicability of simple rules that can be used to summarize these treatments. In the field of regenerative medicine no widely accepted paradigm is currently available that can guide formulation of new theories on the mechanism of regeneration in adults and open new directions for improved regeneration outcomes. The four rules have emerged from multiyear quantitative studies with skin and peripheral nerve regeneration using scaffold libraries based on a simple, well-defined collagen scaffold. These largely quantitative rules distinguish sharply between spontaneously regenerative and nonregenerative tissues, select the two reactants that are required for regeneration, recognize the essential modification of the wound healing process that must be realized prior to regeneration, and identify three structural features of scaffolds that are required for regenerative activity. The combined evidence points at certain requirements for the structure of a collagen scaffold with regenerative activity. An active scaffold emerges as a temporarily insoluble collagen surface, equipped with sufficient ligands for integrins of contractile cells, that inhibits wound contraction while also serving as a topographic template for new stroma synthesis. The four rules, based on studies with just two organs (skin and peripheral nerves), are now viewed in the context of ongoing studies using scaffolds based on decellularized matrices, which are mostly based on collagen. Decellularized matrices have been used during the past few years to regenerate, in whole or in part, the urethra, the abdominal wall, the Achilles tendon, the bladder, the trachea and other organs in several animal models and occasionally in humans. Although these acellular matrices are distinctly different from simple collagen scaffolds, and the methods used by the investigators are still evolving, the results obtained

  15. Characterization of a nanoscale S-layer protein based template for biomolecular patterning. (United States)

    Wong, Wing Sze; Yung, Pun To


    Well organized template for biomolecular conjugation is the foundation for biosensing. Most of the current devices are fabricated using lithographic patterning processes and self-assembly monolayer (SAM) methods. However, the research toward developing a sub-10 nm patterned, self-regenerated template on various types of substrates is limited, mainly due to the limited functional groups of the building material. Bacterial surface layer proteins (S-layer proteins) can self-assemble into ordered lattice with regular pore sizes of 2-8 nm on different material supports and interfaces. The ordered structure can regenerate after extreme variations of solvent conditions. In this work, we developed a nanoscale biomolecular template based on S-layer proteins on gold surface for fabrication of sensing layer in biosensors. S-layer proteins were isolated from Bacillus cereus, Lysinibacillus sphaericus and Geobacillus stearothermophilus. Protein concentrations were measured by Bradford assay. The protein purities were verified by SDS-PAGE, showing molecular weights ranging from 97-135 kDa. The hydrophilicity of the substrate surface was measured after surface treatments of protein recrystallization. Atomic force microscopic (AFM) measurement was performed on substrate surface, indicating a successful immobilization of a monolayer of S-layer protein with 8-9 nm height on gold surface. The template can be applied on various material supports and acts as a self-regenerated sensing layer of biosensors in the future.

  16. The LOLITA User-Definable Template Interface


    Košmelj, Katarina


    The development of user-definable templates interfaces which allow the user to design new templates definitions in a user-friendly way is a new issue in the field of information extraction. The LOLITA user-definable templates interface allows the user to define new templates using sentences in natural language text with a few restrictions and formal elements. This approach is rather different from previous approaches to information extraction which require developers to code the template defi...

  17. Stirling convertor regenerators

    CERN Document Server

    Ibrahim, Mounir B


    Stirling Convertor Regenerators addresses the latest developments and future possibilities in the science and practical application of Stirling engine regenerators and technology. Written by experts in the vanguard of alternative energy, this invaluable resource presents integral scientific details and design concepts associated with Stirling converter regenerators. Content is reinforced with novel insights and remarkable firsthand experience that the authors and their colleagues acquired while working at the National Aeronautics and Space Administration (NASA) and other leading organizations.

  18. Indentation hardness: A simple test that correlates with the dissipated-energy predictor for fatigue-life in bovine pericardium membranes for bioprosthetic heart valves. (United States)

    Tobaruela, Almudena; Rojo, Francisco Javier; García Paez, José María; Bourges, Jean Yves; Herrero, Eduardo Jorge; Millán, Isabel; Alvarez, Lourdes; Cordon, Ángeles; Guinea, Gustavo V


    The aim of this study was to evaluate the variation of hardness with fatigue in calf pericardium, a biomaterial commonly used in bioprosthetic heart valves, and its relationship with the energy dissipated during the first fatigue cycle that has been shown to be a predictor of fatigue-life (García Páez et al., 2006, 2007; Rojo et al., 2010). Fatigue tests were performed in vitro on 24 pericardium specimens cut in a root-to-apex direction. The specimens were subjected to a maximum stress of 1MPa in blocks of 10, 25, 50, 100, 250, 500, 1000 and 1500 cycles. By means of a modified Shore A hardness test procedure, the hardness of the specimen was measured before and after fatigue tests. Results showed a significant correlation of such hardness with fatigue performance and with the energy dissipated in the first cycle of fatigue, a predictor of pericardium durability. The study showed indentation hardness as a simple and reliable indicator of mechanical performance, one which could be easily implemented in improving tissue selection.

  19. Biometric template transformation: a security analysis (United States)

    Nagar, Abhishek; Nandakumar, Karthik; Jain, Anil K.


    One of the critical steps in designing a secure biometric system is protecting the templates of the users that are stored either in a central database or on smart cards. If a biometric template is compromised, it leads to serious security and privacy threats because unlike passwords, it is not possible for a legitimate user to revoke his biometric identifiers and switch to another set of uncompromised identifiers. One methodology for biometric template protection is the template transformation approach, where the template, consisting of the features extracted from the biometric trait, is transformed using parameters derived from a user specific password or key. Only the transformed template is stored and matching is performed directly in the transformed domain. In this paper, we formally investigate the security strength of template transformation techniques and define six metrics that facilitate a holistic security evaluation. Furthermore, we analyze the security of two wellknown template transformation techniques, namely, Biohashing and cancelable fingerprint templates based on the proposed metrics. Our analysis indicates that both these schemes are vulnerable to intrusion and linkage attacks because it is relatively easy to obtain either a close approximation of the original template (Biohashing) or a pre-image of the transformed template (cancelable fingerprints). We argue that the security strength of template transformation techniques must consider also consider the computational complexity of obtaining a complete pre-image of the transformed template in addition to the complexity of recovering the original biometric template.

  20. Quantificational Etching of AAO Template

    Institute of Scientific and Technical Information of China (English)

    Guojun SONG; Dong CHEN; Zhi PENG; Xilin SHE; Jianjiang LI; Ping HAN


    Ni nanowires were prepared by electrodeposition in porous anodized aluminum oxide (AAO) template from a composite electrolyte solution. Well-ordered Ni nanowire arrays with controllable length were then made by the partial removal of AAO using a mixture of phosphoric acid and chromic acid (6 wt pct H3PO4:1.8 wt pct H3CrO4). The images of Ni nanowire arrays were studied by scanning electron microscopy (SEM) to determine the relationship between etching time and the length of Ni nanowire arrays. The results indicate that the length of nanowires exposed from the template can be accurately controlled by controlling etching time.

  1. Progress of NIL template making (United States)

    Yusa, Satoshi; Hiraka, Takaaki; Kobiki, Ayumi; Sasaki, Shiho; Itoh, Kimio; Toyama, Nobuhito; Kurihara, Masaaki; Mohri, Hiroshi; Hayashi, Naoya


    Nano-imprint lithography (NIL) has been counted as one of the lithography solutions for hp32nm node and beyond. Recently, the small line edge roughness (LER) as well as the potentially high resolution that will ensure no-OPC mask feature is attracting many researchers. The template making is one of the most critical issues for the realization of NIL. Especially when we think of a practical template fabrication process on a 65mm square format that is going to be the industry standard, the resolution of the template making process showed a limitation. We have achieved for the first time an hp22nm resolution on the 65nm template format. Both line and space patterns and hole patterns were well resolved. Regarding dot patterns, we still need improvement, but we have achieved resolution down to hp28nm. Although so far we cannot achieve these resolution limits of various pattern category at the same time on one substrate, an intermediate process condition showed sufficient uniformity both in lateral CD and in vertical depth. Global pattern image placement also showed sufficient numbers at this stage of lithography development. A 20nm feature (with a pitch of 80nm) showed sufficient imprint result.

  2. Supply-Chain Optimization Template (United States)

    Quiett, William F.; Sealing, Scott L.


    The Supply-Chain Optimization Template (SCOT) is an instructional guide for identifying, evaluating, and optimizing (including re-engineering) aerospace- oriented supply chains. The SCOT was derived from the Supply Chain Council s Supply-Chain Operations Reference (SCC SCOR) Model, which is more generic and more oriented toward achieving a competitive advantage in business.

  3. Viral-templated Palladium Nanocatalysts (United States)

    Yang, Cuixian

    Despite recent progress on nanocatalysis, there exist several critical challenges in simple and readily controllable nanocatalyst synthesis including the unpredictable particle growth, deactivation of catalytic activity, cumbersome catalyst recovery and lack of in-situ reaction monitoring. In this dissertation, two novel approaches are presented for the fabrication of viral-templated palladium (Pd) nanocatalysts, and their catalytic activities for dichromate reduction reaction and Suzuki Coupling reaction were thoroughly studied. In the first approach, viral template based bottom-up assembly is employed for the Pd nanocatalyst synthesis in a chip-based format. Specifically, genetically displayed cysteine residues on each coat protein of Tobacco Mosaic Virus (TMV) templates provide precisely spaced thiol functionalities for readily controllable surface assembly and enhanced formation of catalytically active Pd nanoparticles. Catalysts with the chip-based format allow for simple separation and in-situ monitoring of the reaction extent. Thorough examination of synthesis-structure-activity relationship of Pd nanoparticles formed on surface-assembled viral templates shows that Pd nanoparticle size, catalyst loading density and catalytic activity of viral-templated Pd nanocatalysts can be readily controlled simply by tuning the synthesis conditions. The viral-templated Pd nanocatalysts with optimized synthesis conditions are shown to have higher catalytic activity per unit Pd mass than the commercial Pd/C catalysts. Furthermore, tunable and selective surface assembly of TMV biotemplates is exploited to control the loading density and location of Pd nanocatalysts on solid substrates via preferential electroless deposition. In addition, the catalytic activities of surface-assembled TMV-templated Pd nanocatalysts were also investigated for the ligand-free Suzuki Coupling reaction under mild reaction conditions. The chip-based format enables simple catalyst separation and

  4. The Analysis of Activated Carbon Regeneration Technologies

    Institute of Scientific and Technical Information of China (English)



    A series of methods for activated carbon regeneration were briefly introduced.Such as thermal regeneration,chemical regeneration,biochemical regeneration,and newly supercritical fluid regeneration, electrochemical regeneration,light-catalyzed regeneration,and microwave radiation method,and the developing trend of activated carbon regeneration was predicted.

  5. National Wildlife Refuge System Survey Protocol Template (United States)

    US Fish and Wildlife Service, Department of the Interior — This template was developed for drafting National Wildlife Refuge System (NWRS) Survey Protocols. The template is arranged in the same order as the eight basic...

  6. Web Template Extraction Based on Hyperlink Analysis

    Directory of Open Access Journals (Sweden)

    Julián Alarte


    Full Text Available Web templates are one of the main development resources for website engineers. Templates allow them to increase productivity by plugin content into already formatted and prepared pagelets. For the final user templates are also useful, because they provide uniformity and a common look and feel for all webpages. However, from the point of view of crawlers and indexers, templates are an important problem, because templates usually contain irrelevant information such as advertisements, menus, and banners. Processing and storing this information is likely to lead to a waste of resources (storage space, bandwidth, etc.. It has been measured that templates represent between 40% and 50% of data on the Web. Therefore, identifying templates is essential for indexing tasks. In this work we propose a novel method for automatic template extraction that is based on similarity analysis between the DOM trees of a collection of webpages that are detected using menus information. Our implementation and experiments demonstrate the usefulness of the technique.

  7. Regeneration and reprogramming compared

    Directory of Open Access Journals (Sweden)

    Robles Vanesa


    Full Text Available Abstract Background Dedifferentiation occurs naturally in mature cell types during epimorphic regeneration in fish and some amphibians. Dedifferentiation also occurs in the induction of pluripotent stem cells when a set of transcription factors (Oct4, Sox2, Klf4 and c-Myc is over expressed in mature cell types. Results We hypothesised that there are parallels between dedifferentiation or reprogramming of somatic cells to induced pluripotent stem cells and the natural process of dedifferentiation during epimorphic regeneration. We analysed expression levels of the most commonly used pluripotency associated factors in regenerating and non-regenerating tissue and compared them with levels in a pluripotent reference cell. We found that some of the pluripotency associated factors (oct4/pou5f1, sox2, c-myc, klf4, tert, sall4, zic3, dppa2/4 and fut1, a homologue of ssea1 were expressed before and during regeneration and that at least two of these factors (oct4, sox2 were also required for normal fin regeneration in the zebrafish. However these factors were not upregulated during regeneration as would be expected if blastema cells acquired pluripotency. Conclusions By comparing cells from the regeneration blastema with embryonic pluripotent reference cells we found that induced pluripotent stem and blastema cells do not share pluripotency. However, during blastema formation some of the key reprogramming factors are both expressed and are also required for regeneration to take place. We therefore propose a link between partially reprogrammed induced pluripotent stem cells and the half way state of blastema cells and suggest that a common mechanism might be regulating these two processes.

  8. Strategies for lung regeneration

    Directory of Open Access Journals (Sweden)

    Thomas H. Petersen


    Full Text Available Due to the limited ability of the adult lung to regenerate and the frequency of lung disease, the lung is a tissue that can especially benefit from regenerative medicine. Prospects for lung regeneration have made great strides in the past year. In this review, we summarize recent progress and key challenges for approaches in lung regenerative medicine. With a focus on the matrix components critical for the development of regenerative lung tissues, we discuss possible cell sources for lung regeneration, key matrix effects on cell repopulation, and physical stimuli that will aid in the growth of lung tissues in vitro.

  9. Tooth regeneration: current status. (United States)

    Dadu, Shifali S


    Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  10. Tooth regeneration: Current status

    Directory of Open Access Journals (Sweden)

    Dadu Shifali


    Full Text Available Regeneration of a functional tooth has the potential to be a promising therapeutic strategy. Experiments have shown that with the use of principles of bioengineering along with adult stem cells, scaffold material, and signaling molecules, tooth regeneration is possible. Research work is in progress on creating a viable bioroot with all its support. A new culture needs to be created that can possibly provide all the nutrients to the stem cells. With the ongoing research, tissue engineering is likely to revolutionize dental health and well-being of people by regenerating teeth over the next decade.

  11. Regeneration Heat Exchange

    Energy Technology Data Exchange (ETDEWEB)

    J. Lin


    The original project goals were to establish the viability of the proposed gas turbine regenerator concept by performing the following tasks: (1) Perform detailed design of a working model of the regenerator concept. (2) Construct a ''bench-top'' model of the regenerator concept based upon the detail design. (3) Test the bench-top model and gather data to support the concept's viability. The project funding was used to acquire the tools and material to perform the aforementioned tasks.

  12. Template electrodeposition of catalytic nanomotors. (United States)

    Wang, Joseph


    The combination of nanomaterials with electrode materials has opened new horizons in electroanalytical chemistry, and in electrochemistry in general. Over the past two decades we have witnessed an enormous activity aimed at designing new electrochemical devices based on nanoparticles, nanotubes or nanowires, and towards the use of electrochemical routes--particularly template-assisted electrodeposition--for preparing nanostructured materials. The power of template-assisted electrochemical synthesis is demonstrated in this article towards the preparation and the realization of self-propelled catalytic nanomotors, ranging from Pt-Au nanowire motors to polymer/Pt microtube engines. Design considerations affecting the propulsion behavior of such catalytic nanomotors are discussed along with recent bioanalytical and environmental applications. Despite recent major advances, artificial nanomotors have a low efficiency compared to their natural counterparts. Hopefully, the present Faraday Discussion will stimulate other electrochemistry teams to contribute to the fascinating area of artificial nanomachines.

  13. LTL - The Little Template Library (United States)

    Gössl, C. A.; Drory, N.; Snigula, J.


    The Little Template Library is an expression templates based C++ library for array processing, image processing, FITS and ASCII I/O, and linear algebra. It is released under the GNU Public License (GPL). Although the library is developed with application to astronomical image and data processing in mind, it is by no means restricted to these fields of application. In fact, it qualifies as a fully general array processing package. Focus is laid on a high abstraction level regarding the handling of expressions involving arrays or parts thereof and linear algebra related operations without the usually involved negative impact on performance. The price to pay is dependence on a compiler implementing enough of the current ANSI C++ specification, as well as significantly higher demand on resources at compile time. The LTL provides dynamic arrays of up to 5 dimensions, sub-arrays and slicing, support for fixed size vectors and matrices including basic linear algebra operations, expression templates based evaluation, and I/O facilities for columnar ASCII and FITS format files. In addition it supplies utility classes for statistics, linear and non-linear least squares fitting, and command line and configuration file parsing. YODA (Drory 2002) and all elements of the WeCAPP reduction pipeline (Riffeser et al. 2001, Gössl & Riffeser 2002, 2003) were implemented using the LTL.

  14. Testing sensory evidence against mnemonic templates. (United States)

    Myers, Nicholas E; Rohenkohl, Gustavo; Wyart, Valentin; Woolrich, Mark W; Nobre, Anna C; Stokes, Mark G


    Most perceptual decisions require comparisons between current input and an internal template. Classic studies propose that templates are encoded in sustained activity of sensory neurons. However, stimulus encoding is itself dynamic, tracing a complex trajectory through activity space. Which part of this trajectory is pre-activated to reflect the template? Here we recorded magneto- and electroencephalography during a visual target-detection task, and used pattern analyses to decode template, stimulus, and decision-variable representation. Our findings ran counter to the dominant model of sustained pre-activation. Instead, template information emerged transiently around stimulus onset and quickly subsided. Cross-generalization between stimulus and template coding, indicating a shared neural representation, occurred only briefly. Our results are compatible with the proposal that template representation relies on a matched filter, transforming input into task-appropriate output. This proposal was consistent with a signed difference response at the perceptual decision stage, which can be explained by a simple neural model.

  15. Chemical genetics and regeneration. (United States)

    Sengupta, Sumitra; Zhang, Liyun; Mumm, Jeff S


    Regeneration involves interactions between multiple signaling pathways acting in a spatially and temporally complex manner. As signaling pathways are highly conserved, understanding how regeneration is controlled in animal models exhibiting robust regenerative capacities should aid efforts to stimulate repair in humans. One way to discover molecular regulators of regeneration is to alter gene/protein function and quantify effect(s) on the regenerative process: dedifferentiation/reprograming, stem/progenitor proliferation, migration/remodeling, progenitor cell differentiation and resolution. A powerful approach for applying this strategy to regenerative biology is chemical genetics, the use of small-molecule modulators of specific targets or signaling pathways. Here, we review advances that have been made using chemical genetics for hypothesis-focused and discovery-driven studies aimed at furthering understanding of how regeneration is controlled.

  16. Nanostructured Biomaterials for Regeneration**


    Wei, Guobao; Ma, Peter X.


    Biomaterials play a pivotal role in regenerative medicine, which aims to regenerate and replace lost/dysfunctional tissues or organs. Biomaterials (scaffolds) serve as temporary 3D substrates to guide neo tissue formation and organization. It is often beneficial for a scaffolding material to mimic the characteristics of extracellular matrix (ECM) at the nanometer scale and to induce certain natural developmental or/and wound healing processes for tissue regeneration applications. This article...

  17. I - Template Metaprogramming for Massively Parallel Scientific Computing - Expression Templates

    CERN Document Server

    CERN. Geneva


    Large scale scientific computing raises questions on different levels ranging from the fomulation of the problems to the choice of the best algorithms and their implementation for a specific platform. There are similarities in these different topics that can be exploited by modern-style C++ template metaprogramming techniques to produce readable, maintainable and generic code. Traditional low-level code tend to be fast but platform-dependent, and it obfuscates the meaning of the algorithm. On the other hand, object-oriented approach is nice to read, but may come with an inherent performance penalty. These lectures aim to present he basics of the Expression Template (ET) idiom which allows us to keep the object-oriented approach without sacrificing performance. We will in particular show to to enhance ET to include SIMD vectorization. We will then introduce techniques for abstracting iteration, and introduce thread-level parallelism for use in heavy data-centric loads. We will show to to apply these methods i...

  18. Templated growth of graphenic materials

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas, Nolan W; Connors, L Matthew [Department of Physics, Rice University, 6100 Main, Houston, TX (United States); Ding, Feng [Institute of Textile and Clothing, Hong Kong Polytechnic University, Kowloon (Hong Kong); Yakobson, Boris I [Department of Mechanical Engineering and Materials Science, Rice University, 6100 Main, Houston, TX (United States); Schmidt, Howard K; Hauge, Robert H [Richard E Smalley Institute for Nanoscale Science and Technology, Rice University, 6100 Main, Houston, TX (United States)], E-mail:


    A novel strategy is proposed for the topologically controlled synthesis of extended graphenic sheets by additively reacting carbon into a pre-existing graphene sheet which is on top of a templating substrate. This concept is implemented and demonstrated using chemical vapor deposition (CVD). Novel morphological features observed in this study suggest unusual aspects of the CVD growth process. CVD results demonstrate the basic soundness of the synthesis strategy but highlight the sensitivity of the process to certain types of disruption and the need for alternative forms of embodiment.

  19. A template for design personas

    DEFF Research Database (Denmark)

    Nielsen, Lene; Storgaard Nielsen, Kira; Stage, Jan


    from 13 companies and compares these to an analysis of recommendations from 11 templates from literature. Furthermore, 28 interviews with Danish practitioners with experience in using personas are analyzed for content on persona descriptions. The study finds that a Danish persona style has developed...... that is different from the recommendations in the lack of marketing and business related information and the absence of goals as differentiator for personas. Furthermore, the inspiration and knowledge on personas originates from co-workers and seminars and not much from literature. This indicates that the community...

  20. A Template for Design Personas:

    DEFF Research Database (Denmark)

    Nielsen, Lene; Hansen, Kira Storgaard; Stage, Jan;


    The persona method is gaining widespread use and support. Many researchers have reported from single cases and from novel domains on how they have used the method. However, the way companies and design groups describe personas has not been the focus of attention. This paper analyses 47 descriptions...... from 13 companies and compares these to an analysis of recommendations from 11 templates from literature. Furthermore, 28 interviews with Danish practitioners with experience in using personas are analyzed for content on persona descriptions. The study finds that a Danish persona style has developed...

  1. Hard template synthesis of metal nanowires

    Directory of Open Access Journals (Sweden)

    Go eKawamura


    Full Text Available Metal nanowires (NWs have attracted much attention because of their high electron conductivity, optical transmittance and tunable magnetic properties. Metal NWs have been synthesized using soft templates such as surface stabilizing molecules and polymers, and hard templates such as anodic aluminum oxide, mesoporous oxide, carbon nanotubes. NWs prepared from hard templates are composites of metals and the oxide/carbon matrix. Thus, selecting appropriate elements can simplify the production of composite devices. The resulting NWs are immobilized and spatially arranged, as dictated by the ordered porous structure of the template. This avoids the NWs from aggregating, which is common for NWs prepared with soft templates in solution. Herein, the hard template synthesis of metal NWs is reviewed, and the resulting structures, properties and potential applications are discussed.

  2. Perfluorodecalin and bone regeneration

    Directory of Open Access Journals (Sweden)

    F Tamimi


    Full Text Available Perfluorodecalin (PFD is a chemically and biologically inert biomaterial and, as many perfluorocarbons, is also hydrophobic, radiopaque and has a high solute capacity for gases such as oxygen. In this article we have demonstrated, both in vitro and in vivo, that PFD may significantly enhance bone regeneration. Firstly, the potential benefit of PFD was demonstrated by prolonging the survival of bone marrow cells cultured in anaerobic conditions. These findings translated in vivo, where PFD incorporated into bone-marrow-loaded 3D-printed scaffolds substantially improved their capacity to regenerate bone. Secondly, in addition to biological applications, we have also shown that PFD improves the radiopacity of bone regeneration biomaterials, a key feature required for the visualisation of biomaterials during and after surgical implantation. Finally, we have shown how the extreme hydrophobicity of PFD enables the fabrication of highly cohesive self-setting injectable biomaterials for bone regeneration. In conclusion, perfluorocarbons would appear to be highly beneficial additives to a number of regenerative biomaterials, especially those for bone regeneration.

  3. Vertical Carbon Nanotube Device in Nanoporous Templates (United States)

    Maschmann, Matthew Ralph (Inventor); Fisher, Timothy Scott (Inventor); Sands, Timothy (Inventor); Bashir, Rashid (Inventor)


    A modified porous anodic alumina template (PAA) containing a thin CNT catalyst layer directly embedded into the pore walls. CNT synthesis using the template selectively catalyzes SWNTs and DWNTs from the embedded catalyst layer to the top PAA surface, creating a vertical CNT channel within the pores. Subsequent processing allows for easy contact metallization and adaptable functionalization of the CNTs and template for a myriad of applications.

  4. Influence of template fill in graphoepitaxy DSA (United States)

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


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

  5. Bioelectricity and epimorphic regeneration. (United States)

    Stewart, Scott; Rojas-Muñoz, Agustin; Izpisúa Belmonte, Juan Carlos


    All cells have electric potentials across their membranes, but is there really compelling evidence to think that such potentials are used as instructional cues in developmental biology? Numerous reports indicate that, in fact, steady, weak bioelectric fields are observed throughout biology and function during diverse biological processes, including development. Bioelectric fields, generated upon amputation, are also likely to play a key role during vertebrate regeneration by providing the instructive cues needed to direct migrating cells to form a wound epithelium, a structure unique to regenerating animals. However, mechanistic insight is still sorely lacking in the field. What are the genes required for bioelectric-dependent cell migration during regeneration? The power of genetics combined with the use of zebrafish offers the best opportunity for unbiased identification of the molecular players in bioelectricity.

  6. Comparison between the standard SPM2 template and Korean-standard template in FDG-PET

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hee; Lee, Byeong Il; Song, Ho Chun; Min, Jung Joon; Bom, Hee Seung [Chonnam National University Hospital, Gwangju (Korea, Republic of); Lee, Jae Sung [Seoul National University Hospital, Seoul (Korea, Republic of)


    The preprocessing step of statistical parametric mapping (SPM) requires the procedure of spatial normalization that consists of applying the nonlinear deformations needed to force every particular PET scan to match a reference template. The purpose of this study is to asses the statistic influence of using 2 different templates (the standard SPM2-PET template and Korean-standard PET template) in the normalization. We compared the regional metabolic patterns on 18F-FDG (fluorodeoxyglucose) images obtained from 4 patients with Alzheimers disease (AD) and 16 normal subjects. The statistical outcome of between- group comparison was analyzed with SPM2 and was applied into two levels of thresholds (an uncorrected P value of P <0.001, a corrected P value of P < 0.05). As a result, the most significant hypometabolic region was commonly found in the left temporal gyrus regardless of template type or thresholds. However, inconsistent results including different extent and the t-score statistics representing metabolic changes could be also observed between two templates. While the standard SPM2 template showed hypometabolic regions corresponding to Brodman area (BA) 7 and 9, Korean-standard template was not observed these regions. In addition, hypometabolic regions corresponding to BA 38 and 46 indicated not the standard SPM2 template but Korean-standard template. Statistic result showed that the standard SPM2 template effectively reflects the dorsal region of the brain while Korean-standard template is more sensitive to the medial region of the brain.

  7. A Template for Design Personas:

    DEFF Research Database (Denmark)

    Nielsen, Lene; Hansen, Kira Storgaard; Stage, Jan;


    The persona method is gaining widespread use and support. Many researchers have reported from single cases and from novel domains on how they have used the method. However, the way companies and design groups describe personas has not been the focus of attention. This paper analyses 47 descriptions...... from 13 companies and compares these to an analysis of recommendations from 11 templates from literature. Furthermore, 28 interviews with Danish practitioners with experience in using personas are analyzed for content on persona descriptions. The study finds that a Danish persona style has developed...... that is different from the recommendations in the lack of marketing and business related information and the absence of goals as differentiator for personas. Furthermore, the inspiration and knowledge on personas originates from co-workers and seminars and not much from literature. This indicates that the community...

  8. Testing by C++ template metaprograms

    CERN Document Server

    Pataki, Norbert


    Testing is one of the most indispensable tasks in software engineering. The role of testing in software development has grown significantly because testing is able to reveal defects in the code in an early stage of development. Many unit test frameworks compatible with C/C++ code exist, but a standard one is missing. Unfortunately, many unsolved problems can be mentioned with the existing methods, for example usually external tools are necessary for testing C++ programs. In this paper we present a new approach for testing C++ programs. Our solution is based on C++ template metaprogramming facilities, so it can work with the standard-compliant compilers. The metaprogramming approach ensures that the overhead of testing is minimal at runtime. This approach also supports that the specification language can be customized among other advantages. Nevertheless, the only necessary tool is the compiler itself.

  9. Infection and Pulp Regeneration

    Directory of Open Access Journals (Sweden)

    Sahng G. Kim


    Full Text Available The regeneration of the pulp-dentin complex has been a great challenge to both scientists and clinicians. Previous work has shown that the presence of prior infection may influence the characteristics of tissues formed in the root canal space after regenerative endodontic treatment. The formation of ectopic tissues such as periodontal ligament, bone, and cementum has been observed in the root canal space of immature necrotic teeth with apical periodontitis, while the regeneration of dentin and pulp has been identified in previously non-infected teeth. The current regenerative endodontic therapy utilizes disinfection protocols, which heavily rely on chemical irrigation using conventional disinfectants. From a microbiological point of view, the current protocols may not allow a sufficiently clean root canal microenvironment, which is critical for dentin and pulp regeneration. In this article, the significance of root canal disinfection in regenerating the pulp-dentin complex, the limitations of the current regenerative endodontic disinfection protocols, and advanced disinfection techniques designed to reduce the microorganisms and biofilms in chronic infection are discussed.

  10. Screening for templates that promote crystallization

    NARCIS (Netherlands)

    Urbanus, J.; Roelands, C.P.M.; Horst, J.H. ter; Verdoes, D.; Jansens, P.J.


    In Situ Product Recovery (ISPR) applied in fermentation processes leads to improved yield and productivity of these processes. In principle, ISPR can be achieved using Template Induced Crystallization (TIC), which is one possible ISPR technique. With TIC, templates are added to the solution as a spe

  11. Template synthesis of ordered macroporous hydroxyapatite bioceramics. (United States)

    Ji, Lijun; Jell, Gavin; Dong, Yixiang; Jones, Julian R; Stevens, Molly M


    Hydroxyapatite has found wide application in bone tissue engineering. Here we use a macroporous carbon template to generate highly ordered macroporous hydroxyapatite bioceramics composed of close-packed hollow spherical pores with interconnected channels. The template has advantages for the preparation of ordered materials.

  12. Indexing Images: Testing an Image Description Template. (United States)

    Jorgensen, Corinne


    A template for pictorial image description to be used by novice image searchers in recording their descriptions of images was tested; image attribute classes derived in previous research were used to model the template. Results indicated that users may need training and/or more guidance to correctly assign descriptors to higher-level classes.…

  13. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan


    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  14. Solvable model for template coexistence in protocells

    CERN Document Server

    Fontanari, J F


    Compartmentalization of self-replicating molecules (templates) in protocells is a necessary step towards the evolution of modern cells. However, coexistence between distinct template types inside a protocell can be achieved only if there is a selective pressure favoring protocells with a mixed template composition. Here we study analytically a group selection model for the coexistence between two template types using the diffusion approximation of population genetics. The model combines competition at the template and protocell levels as well as genetic drift inside protocells. At the steady state, we find a continuous phase transition separating the coexistence and segregation regimes, with the order parameter vanishing linearly with the distance to the critical point. In addition, we derive explicit analytical expressions for the critical steady-state probability density of protocell compositions.

  15. Solvable model for template coexistence in protocells (United States)

    Fontanari, J. F.; Serva, M.


    Compartmentalization of self-replicating molecules (templates) in protocells is a necessary step towards the evolution of modern cells. However, coexistence between distinct template types inside a protocell can be achieved only if there is a selective pressure favoring protocells with a mixed template composition. Here we study analytically a group selection model for the coexistence between two template types using the diffusion approximation of population genetics. The model combines competition at the template and protocell levels as well as genetic drift inside protocells. At the steady state, we find a continuous phase transition separating the coexistence and segregation regimes, with the order parameter vanishing linearly with the distance to the critical point. In addition, we derive explicit analytical expressions for the critical steady-state probability density of protocell compositions.

  16. Template Assembly for Detailed Urban Reconstruction

    KAUST Repository

    Nan, Liangliang


    We propose a new framework to reconstruct building details by automatically assembling 3D templates on coarse textured building models. In a preprocessing step, we generate an initial coarse model to approximate a point cloud computed using Structure from Motion and Multi View Stereo, and we model a set of 3D templates of facade details. Next, we optimize the initial coarse model to enforce consistency between geometry and appearance (texture images). Then, building details are reconstructed by assembling templates on the textured faces of the coarse model. The 3D templates are automatically chosen and located by our optimization-based template assembly algorithm that balances image matching and structural regularity. In the results, we demonstrate how our framework can enrich the details of coarse models using various data sets.

  17. Limb regeneration: a new development? (United States)

    Nacu, Eugen; Tanaka, Elly M


    Salamander limb regeneration is a classical model of tissue morphogenesis and patterning. Through recent advances in cell labeling and molecular analysis, a more precise, mechanistic understanding of this process has started to emerge. Long-standing questions include to what extent limb regeneration recapitulates the events observed in mammalian limb development and to what extent are adult- or salamander- specific aspects deployed. Historically, researchers studying limb development and limb regeneration have proposed different models of pattern formation. Here we discuss recent data on limb regeneration and limb development to argue that although patterning mechanisms are likely to be similar, cell plasticity and signaling from nerves play regeneration-specific roles.

  18. A Bayesian method for pulsar template generation

    CERN Document Server

    Imgrund, M; Kramer, M; Lesch, H


    Extracting Times of Arrival from pulsar radio signals depends on the knowledge of the pulsars pulse profile and how this template is generated. We examine pulsar template generation with Bayesian methods. We will contrast the classical generation mechanism of averaging intensity profiles with a new approach based on Bayesian inference. We introduce the Bayesian measurement model imposed and derive the algorithm to reconstruct a "statistical template" out of noisy data. The properties of these "statistical templates" are analysed with simulated and real measurement data from PSR B1133+16. We explain how to put this new form of template to use in analysing secondary parameters of interest and give various examples: We implement a nonlinear filter for determining ToAs of pulsars. Applying this method to data from PSR J1713+0747 we derive ToAs self consistently, meaning all epochs were timed and we used the same epochs for template generation. While the average template contains fluctuations and noise as unavoida...

  19. Bionanomaterials for skin regeneration

    CERN Document Server

    Leonida, Mihaela D


    This book gives a concise overview of bionanomaterials with applications for skin regeneration. The advantages and challenges of nanoscale materials are covered in detail, giving a basic view of the skin structure and conditions that require transdermal or topical applications. Medical applications, such as wound healing, care for burns, skin disease, and cosmetic care, such as aging of the skin and photodamage, and how they benefit from bionanomaterials, are described in detail. A final chapter is devoted to the ethical and social issues related to the use of bionanomaterials for skin regeneration. This is an ideal book for researchers in materials science, medical scientists specialized in dermatology, and cosmetic chemists working in formulations. It can also serve as a reference for nanotechnologists, dermatologists, microbiologists, engineers, and polymer chemists, as well as students studying in these fields.

  20. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc


    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  1. Tissue regeneration with photobiomodulation (United States)

    Tang, Elieza G.; Arany, Praveen R.


    Low level light therapy (LLLT) has been widely reported to reduce pain and inflammation and enhance wound healing and tissue regeneration in various settings. LLLT has been noted to have both stimulatory and inhibitory biological effects and these effects have been termed Photobiomodulation (PBM). Several elegant studies have shown the key role of Cytochrome C oxidase and ROS in initiating this process. The downstream biological responses remain to be clearly elucidated. Our work has demonstrated activation of an endogenous latent growth factor complex, TGF-β1, as one of the major biological events in PBM. TGF-β1 has critical roles in various biological processes especially in inflammation, immune responses, wound healing and stem cell biology. This paper overviews some of the studies demonstrating the efficacy of PBM in promoting tissue regeneration.

  2. Templated Growth of Magnetic Recording Media (United States)

    Sundar, Vignesh

    Current and potential next-generation magnetic recording technologies are based on the writing and reading of bits on a magnetic thin film with a granular microstructure, with grains of the magnetic material surrounded by an amorphous segregant. In order to realize the highest achievable data storage capabilities, there is a need for better control of the magnetic media microstructure, particularly in terms of minimizing grain size and grain boundary thickness distributions. In this work, a guided magnetic media growth is attempted by creating a pre-fabricated template with a specific material and morphology. The template is designed in such a way that, when magnetic media consisting of the magnetic alloy and segregant are sputtered, the sites on the template result in a controlled two-phase growth of magnetic media. The template is fabricated using self-assembling block copolymers, which can be used to fabricate nanostructures with a regular hexagonal lattice of spheres of one block in the other's matrix. These are then used as etch-masks to fabricate the template. In this thesis, we describe the approach used to fabricate these templates and demonstrate the two-phase growth of magnetic recording media. In such an approach, the magnetic grain size is defined by the uniform pitch of the block copolymer pattern, resulting in a uniform microstructure with much better grain size distribution than can be obtained with conventional un-templated media growth. The templated growth technique is also a suitable additive technique for the fabrication of Bit Patterned Media, another potential next-generation technology wherein the magnetic bits are isolated patterned islands. Combining nanoimprint lithography with templated growth, we can generate a long range spatially ordered array of magnetic islands with no etching of the magnetic material.

  3. Low Temperature Regenerator Study. (United States)


    effect. The idealized cycle achieves the same theoretical coefficient of performance (COP) as the theoretical Carnot cycle , whose limiting performance...DISTRIBUTION STATEMENT (of the abstract *irt.,ed in Block 20, iI different it oe) I8. SUPPLEMENTARY NOTES I9. KEY WORDS (Continute on reverse @do of noco*oy...PERFORMANCE ............ 64 3.1 Introduction ..... 0 ... . ......... ... . 64 3.2 Stirling Cycle Analysis ................. 71 3.2.1 Simple Regenerator Model

  4. [Periodontitis and tissue regeneration]. (United States)

    Yamazaki, Kazuhisa


    Chronic periodontitis is a destructive disease that affects the supporting structures of the teeth including periodontal ligament, cementum, and alveolar bone. If left untreated, patients may lose multiple teeth and extensive prosthetic treatment will be required. In order to re-engineer lost tooth-supporting tissues, various therapeutic modalities have been used clinically. Periodontal regeneration procedures including guided tissue regeneration have achieved substantial effects. However, there are several issues to be solved. They are highly technique-sensitive, applicable to limited cases which are susceptible to treatment, and supposed to have relatively low predictability. Therefore, it is necessary to develop new approaches to improve the predictability and effectiveness of regenerative therapies for periodontal tissues. Recently, the concept of tissue engineering has been introduced to restore lost tissues more effectively where the biological process of healing is mimicked. To achieve this, integration of three key elements is required: progenitor/stem cells, growth factors and the extracellular matrix scaffold. Although it has been shown that implantation of bone marrow-derived mesenchymal stem cells into periodontal osseous defects induced regeneration of cementum, periodontal ligament and alveolar bone in dogs, further extensive preclinical studies are required. On the other hand, application of growth factors, particularly basic fibroblast growth factor in the treatment of human periodontitis, is promising and is now in clinical trial. Furthermore, the rate of release of growth factor from the scaffold also can profoundly affect the results of tissue engineering strategies and the development of new materials is expected. In addition, as tissue regenerative potential is negatively regulated by aging, the effects of aging have to be clarified to gain complete regeneration.

  5. Templating irreversible covalent macrocyclization by using anions. (United States)

    Kataev, Evgeny A; Kolesnikov, Grigory V; Arnold, Rene; Lavrov, Herman V; Khrustalev, Victor N


    Inorganic anions were used as templates in the reaction between a diamine and an activated diacid to form macrocyclic amides. The reaction conditions were found to perform the macrocyclization sufficiently slow to observe a template effect. A number of analytical methods were used to clarify the reaction mechanisms and to show that the structure of the intermediate plays a decisive role in determining the product distribution. For the macrocyclization under kinetic control, it was shown that the amount of a template, the conformational rigidity of building blocks, and the anion affinities of reaction components and intermediates are important parameters that one should take into consideration to achieve high yields.


    Institute of Scientific and Technical Information of China (English)


    Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration. Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected. Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin. Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19)of pancreatic tissues were observed by immunohistochemistry. Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration. Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation. At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme. During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin. During pancreatic regeneration after damage, nestin expression of islet cells increased. Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration. During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.

  7. A proposal for a drug information database and text templates for generating package inserts. (United States)

    Okuya, Ryo; Kimura, Masaomi; Ohkura, Michiko; Tsuchiya, Fumito


    To prevent prescription errors caused by information systems, a database to store complete and accurate drug information in a user-friendly format is needed. In previous studies, the primary method for obtaining data stored in a database is to extract drug information from package inserts by employing pattern matching or more sophisticated methods such as text mining. However, it is difficult to obtain a complete database because there is no strict rule concerning expressions used to describe drug information in package inserts. The authors' strategy was to first build a database and then automatically generate package inserts by embedding data in the database using templates. To create this database, the support of pharmaceutical companies to input accurate data is required. It is expected that this system will work, because these companies can earn merit for newly developed drugs to decrease the effort to create package inserts from scratch. This study designed the table schemata for the database and text templates to generate the package inserts. To handle the variety of drug-specific information in the package inserts, this information in drug composition descriptions was replaced with labels and the replacement descriptions utilizing cluster analysis were analyzed. To improve the method by which frequently repeated ingredient information and/or supplementary information are stored, the method was modified by introducing repeat tags in the templates to indicate repetition and improving the insertion of data into the database. The validity of this method was confirmed by inputting the drug information described in existing package inserts and checking that the method could regenerate the descriptions in the original package insert. In future research, the table schemata and text templates will be extended to regenerate other information in the package inserts.

  8. Fascinating properties of bioactive templated glasses: A new generation of nanostructured bioceramics (United States)

    Izquierdo-Barba, Isabel; Vallet-Regí, María


    This review article, dedicated to Prof. Osamu Terasaki, is focused on current trends in nanostructured bioceramics in the field of bone repair and regeneration. This communication overviews the main characteristics of so called "templated glasses" recently described which exhibit an outstanding bioactive behavior compared with conventional bioactive glasses. A deep study regarding the control of textural, structural and compositional properties in the nanometric scale in relation to the charming bioactivity properties described for these nanostructured materials is herein discussed. The possibility to tailor such properties offers a wide range of reactivity/bioactivity depending on the medical application requested.

  9. Templated and template-free fabrication strategies for zero-dimensional hollow MOF superstructures. (United States)

    Kim, Hyehyun; Lah, Myoung Soo


    Various fabrication strategies for hollow metal-organic framework (MOF) superstructures are reviewed and classified using various types of external templates and their properties. Hollow MOF superstructures have also been prepared without external templates, wherein unstable intermediates obtained during reactions convert to the final hollow MOF superstructures. Many hollow MOF superstructures have been fabricated using hard templates. After the core-shell core@MOF structure was prepared using a hard template, the core was selectively etched to generate a hollow MOF superstructure. Another approach for generating hollow superstructures is to use a solid reactant as a sacrificial template; this method requires no additional etching process. Soft templates such as discontinuous liquid/emulsion droplets and gas bubbles in a continuous soft phase have also been employed to prepare hollow MOF superstructures.

  10. Template for safety reports with descriptive example

    Energy Technology Data Exchange (ETDEWEB)



    This report provides a template for future safety reports on long-term safety in support of important decisions and permit applications in connection with the construction of a deep repository system. The template aims at providing a uniform structure for describing long-term safety, after the repository has been closed and sealed. The availability of such a structure will simplify both preparation and review of the safety reports, and make it possible to follow how safety assessments are influenced by the progressively more detailed body of data that emerges. A separate section containing `descriptive examples` has been appended to the template. This section illustrates what the different chapters of the template should contain. 279 refs.

  11. Template Approach for Adaptive Learning Strategies

    NARCIS (Netherlands)

    Abbing, Jana; Koidl, Kevin


    Please, cite this publication as: Abbing, J. & Koidl, K. (2006). Template Approach for Adaptive Learning Strategies. Proceedings of Adaptive Hypermedia. June, Dublin, Ireland. Retrieved June 30th, 2006, from

  12. Performance Evaluation of Biometric Template Update

    CERN Document Server

    Giot, Romain; Dorizzi, Bernadette


    Template update allows to modify the biometric reference of a user while he uses the biometric system. With such kind of mechanism we expect the biometric system uses always an up to date representation of the user, by capturing his intra-class (temporary or permanent) variability. Although several studies exist in the literature, there is no commonly adopted evaluation scheme. This does not ease the comparison of the different systems of the literature. In this paper, we show that using different evaluation procedures can lead in different, and contradictory, interpretations of the results. We use a keystroke dynamics (which is a modality suffering of template ageing quickly) template update system on a dataset consisting of height different sessions to illustrate this point. Even if we do not answer to this problematic, it shows that it is necessary to normalize the template update evaluation procedures.

  13. Nanowires and nanostructures fabrication using template methods

    DEFF Research Database (Denmark)

    Mátéfi-Tempfli, Stefan; Mátéfi-Tempfli, M.; Vlad, A.;


    One of the great challenges of today is to find reliable techniques for the fabrication of nanomaterials and nanostructures. Methods based on template synthesis and on self organization are the most promising due to their easiness and low cost. This paper focuses on the electrochemical synthesis ...... of nanowires and nanostructures using nanoporous host materials such as supported anodic aluminum considering it as a key template for nanowires based devices. New ways are opened for applications by combining such template synthesis methods with nanolithographic techniques.......One of the great challenges of today is to find reliable techniques for the fabrication of nanomaterials and nanostructures. Methods based on template synthesis and on self organization are the most promising due to their easiness and low cost. This paper focuses on the electrochemical synthesis...

  14. Polymeric hydrogels for burn wound care: Advanced skin wound dressings and regenerative templates

    Directory of Open Access Journals (Sweden)

    Marta Madaghiele


    Full Text Available Wound closure represents a primary goal in the treatment of very deep and/or large wounds, for which the mortality rate is particularly high. However, the spontaneous healing of adult skin eventually results in the formation of epithelialized scar and scar contracture (repair, which might distort the tissues and cause lifelong deformities and disabilities. This clinical evidence suggests that wound closure attained by means of skin regeneration, instead of repair, should be the true goal of burn wound management. The traditional concept of temporary wound dressings, able to stimulate skin healing by repair, is thus being increasingly replaced by the idea of temporary scaffolds, or regenerative templates, able to promote healing by regeneration. As wound dressings, polymeric hydrogels provide an ideal moisture environment for healing while protecting the wound, with the additional advantage of being comfortable to the patient, due to their cooling effect and non-adhesiveness to the wound tissue. More importantly, recent advances in regenerative medicine demonstrate that bioactive hydrogels can be properly designed to induce at least partial skin regeneration in vivo. The aim of this review is to provide a concise insight on the key properties of hydrogels for skin healing and regeneration, particularly highlighting the emerging role of hydrogels as next generation skin substitutes for the treatment of full-thickness burns.

  15. Macroporous polymer foams by hydrocarbon templating


    Shastri, Venkatram Prasad; Martin, Ivan; Langer, Robert


    Porous polymeric media (polymer foams) are utilized in a wide range of applications, such as thermal and mechanical insulators, solid supports for catalysis, and medical devices. A process for the production of polymer foams has been developed. This process, which is applicable to a wide range of polymers, uses a hydrocarbon particulate phase as a template for the precipitation of the polymer phase and subsequent pore formation. The use of a hydrocarbon template allows for enhanced control ov...

  16. Lipid bilayers on nano-templates (United States)

    Noy, Aleksandr; Artyukhin, Alexander B.; Bakajin, Olgica; Stoeve, Pieter


    A lipid bilayer on a nano-template comprising a nanotube or nanowire and a lipid bilayer around the nanotube or nanowire. One embodiment provides a method of fabricating a lipid bilayer on a nano-template comprising the steps of providing a nanotube or nanowire and forming a lipid bilayer around the polymer cushion. One embodiment provides a protein pore in the lipid bilayer. In one embodiment the protein pore is sensitive to specific agents

  17. Scalable, Fast Cloud Computing with Execution Templates


    Mashayekhi, Omid; Qu, Hang; Shah, Chinmayee; Levis, Philip


    Large scale cloud data analytics applications are often CPU bound. Most of these cycles are wasted: benchmarks written in C++ run 10-51 times faster than frameworks such as Naiad and Spark. However, calling faster implementations from those frameworks only sees moderate (3-5x) speedups because their control planes cannot schedule work fast enough. This paper presents execution templates, a control plane abstraction for CPU-bound cloud applications, such as machine learning. Execution template...

  18. Biomaterial Selection for Tooth Regeneration



    Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or s...

  19. Multi-template polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Elena Kalle


    Full Text Available PCR is a formidable and potent technology that serves as an indispensable tool in a wide range of biological disciplines. However, due to the ease of use and often lack of rigorous standards many PCR applications can lead to highly variable, inaccurate, and ultimately meaningless results. Thus, rigorous method validation must precede its broad adoption to any new application. Multi-template samples possess particular features, which make their PCR analysis prone to artifacts and biases: multiple homologous templates present in copy numbers that vary within several orders of magnitude. Such conditions are a breeding ground for chimeras and heteroduplexes. Differences in template amplification efficiencies and template competition for reaction compounds undermine correct preservation of the original template ratio. In addition, the presence of inhibitors aggravates all of the above-mentioned problems. Inhibitors might also have ambivalent effects on the different templates within the same sample. Yet, no standard approaches exist for monitoring inhibitory effects in multitemplate PCR, which is crucial for establishing compatibility between samples.

  20. Synthetic Phage for Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    So Young Yoo


    Full Text Available Controlling structural organization and signaling motif display is of great importance to design the functional tissue regenerating materials. Synthetic phage, genetically engineered M13 bacteriophage has been recently introduced as novel tissue regeneration materials to display a high density of cell-signaling peptides on their major coat proteins for tissue regeneration purposes. Structural advantages of their long-rod shape and monodispersity can be taken together to construct nanofibrous scaffolds which support cell proliferation and differentiation as well as direct orientation of their growth in two or three dimensions. This review demonstrated how functional synthetic phage is designed and subsequently utilized for tissue regeneration that offers potential cell therapy.

  1. Understanding Urban Regeneration in Turkey (United States)

    Candas, E.; Flacke, J.; Yomralioglu, T.


    In Turkey, rapid population growth, informal settlements, and buildings and infrastructures vulnerable to natural hazards are seen as the most important problems of cities. Particularly disaster risk cannot be disregarded, as large parts of various cities are facing risks from earthquakes, floods and landslides and have experienced loss of lives in the recent past. Urban regeneration is an important planning tool implemented by local and central governments in order to reduce to disaster risk and to design livable environments for the citizens. The Law on the Regeneration of Areas under Disaster Risk, commonly known as the Urban Regeneration Law, was enacted in 2012 (Law No.6306, May 2012). The regulation on Implementation of Law No. 6306 explains the fundamental steps of the urban regeneration process. The relevant institutions furnished with various authorities such as expropriation, confiscation and changing the type and place of your property which makes urban regeneration projects very important in terms of property rights. Therefore, urban regeneration projects have to be transparent, comprehensible and acceptable for all actors in the projects. In order to understand the urban regeneration process, the legislation and projects of different municipalities in Istanbul have been analyzed. While some steps of it are spatial data demanding, others relate to land values. In this paper an overview of the urban regeneration history and activities in Turkey is given. Fundamental steps of the urban regeneration process are defined, and particularly spatial-data demanding steps are identified.

  2. Calcifying tissue regeneration via biomimetic materials chemistry. (United States)

    Green, David W; Goto, Tazuko K; Kim, Kye-Seong; Jung, Han-Sung


    Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel and bone or that can be used to fully regenerate them with integrated cell populations. Biomimetic materials chemistry encompasses the two processes of crystal formation and mineralization of crystals into inorganic formations on organic templates. This review will revisit the successes of biomimetics materials chemistry in regenerative medicine, including coccolithophore simulants able to promote in vivo bone formation. In-depth knowledge of biomineralization throughout evolution informs the biomimetic materials chemist of the most effective techniques for regenerative framework construction exemplified via exploitation of liquid crystals (LCs) and complex self-organizing media. Therefore, a new innovative direction would be to create chemical environments that perform reaction-diffusion exchanges as the basis for building complex biomimetic inorganic structures. This has evolved widely in biology, as have LCs, serving as self-organizing templates in pattern formation of structural biomaterials. For instance, a study is highlighted in which artificially fabricated chiral LCs, made from bacteriophages are transformed into a faithful copy of enamel. While chemical-based strategies are highly promising at creating new biomimetic structures there are limits to the degree of complexity that can be generated. Thus, there may be good reason to implement living or artificial cells in 'morphosynthesis' of complex inorganic constructs. In the future, cellular construction is probably

  3. Polymer scaffolds with preferential parallel grooves enhance nerve regeneration. (United States)

    Mobasseri, Atefeh; Faroni, Alessandro; Minogue, Ben M; Downes, Sandra; Terenghi, Giorgio; Reid, Adam J


    We have modified the surface topography of poly ɛ-caprolactone (PCL) and polylactic acid (PLA) blended films to improve cell proliferation and to guide the regeneration of peripheral nerves. Films with differing shaped grooves were made using patterned silicon templates, sloped walls (SL), V-shaped (V), and square-shaped (SQ), and compared with nongrooved surfaces with micropits. The solvent cast films were tested in vitro using adult adipose-derived stem cells differentiated to Schwann cell-like cells. Cell attachment, proliferation, and cell orientation were all improved on the grooved surfaces, with SL grooves giving the best results. We present in vivo data on Sprague-Dawley rat sciatic nerve injury with a 10-mm gap, evaluating nerve regeneration at 3 weeks across a polymer nerve conduit modified with intraluminal grooves (SL, V, and SQ) and differing wall thicknesses (70, 100, 120, and 210 μm). The SL-grooved nerve conduit showed a significant improvement over the other topographical-shaped grooves, while increasing the conduit wall thickness saw no positive effect on the biological response of the regenerating nerve. Furthermore, the preferred SL-grooved conduit (C) with 70 μm wall thickness was compared with the current clinical gold standard of autologous nerve graft (Ag) in the rat 10-mm sciatic nerve gap model. At 3 weeks postsurgery, all nerve gaps across both groups were bridged with regenerated nerve fibers. At 16 weeks, features of regenerated axons were comparable between the autograft (Ag) and conduit (C) groups. End organ assessments of muscle weight, electromyography, and skin reinnervation were also similar between the groups. The comparable experimental outcome between conduit and autograft, suggests that the PCL/PLA conduit with inner lumen microstructured grooves could be used as a potential alternative treatment for peripheral nerve repair.

  4. Simplification of Template-free Method to Prepare Polyaniline Nanotubes

    Institute of Scientific and Technical Information of China (English)


    1 Introduction Conducting polymer nanostructures (e.g.nanotubes or nanofibers) have received considerable attention owing their unique properties and promising applications in technology and nano-devices[1]. Conducting polymer nanostructures can be generally synthesized through "hard" and "soft" template method.Usually an external hard template in a "hard-template" method is required and the post-treatment of removing template is rather tedious."Soft-template" method is advantageous of omitting external...

  5. Nanobiomaterials for neural regeneration

    Institute of Scientific and Technical Information of China (English)

    Nuan Chen; Lingling Tian; Liumin He; Seeram Ramakrishna


    Diseases and disorders associated with nervous system such as injuries by trauma and neurodegeneration are shown to be one of the most serious problems in medicine, requiring innovative strategies to trigger and enhance the nerve regeneration. Tissue engineering aims to provide a highly biomimetic environment by using a combination of cells, materials and suitable biological cues, by which the lost body part may be regenerated or even fully rebuilt. Electrospinning, being able to produce extracellular matrix (ECM)-like nanostructures with great lfexibility in design and choice of materials, have demonstrated their great po-tential for fabrication of nerve tissue engineered scaffolds. The review here begins with a brief description of the anatomy of native nervous system, which provides basic knowledge and ideas for the design of nerve tissue scaffolds, followed by ifve main parts in the design of electrospun nerve tissue engineered scaffolds including materials selection, structural design,in vitro bioreactor, functionalization and cellular support. Performances of biomimetic electrospun nanofibrous nerve implant devices are also reviewed. Finally, future directions for advanced electrospun nerve tissue engineered scaffolds are discussed.

  6. Waveform Similarity Analysis: A Simple Template Comparing Approach for Detecting and Quantifying Noisy Evoked Compound Action Potentials. (United States)

    Potas, Jason Robert; de Castro, Newton Gonçalves; Maddess, Ted; de Souza, Marcio Nogueira


    Experimental electrophysiological assessment of evoked responses from regenerating nerves is challenging due to the typical complex response of events dispersed over various latencies and poor signal-to-noise ratio. Our objective was to automate the detection of compound action potential events and derive their latencies and magnitudes using a simple cross-correlation template comparison approach. For this, we developed an algorithm called Waveform Similarity Analysis. To test the algorithm, challenging signals were generated in vivo by stimulating sural and sciatic nerves, whilst recording evoked potentials at the sciatic nerve and tibialis anterior muscle, respectively, in animals recovering from sciatic nerve transection. Our template for the algorithm was generated based on responses evoked from the intact side. We also simulated noisy signals and examined the output of the Waveform Similarity Analysis algorithm with imperfect templates. Signals were detected and quantified using Waveform Similarity Analysis, which was compared to event detection, latency and magnitude measurements of the same signals performed by a trained observer, a process we called Trained Eye Analysis. The Waveform Similarity Analysis algorithm could successfully detect and quantify simple or complex responses from nerve and muscle compound action potentials of intact or regenerated nerves. Incorrectly specifying the template outperformed Trained Eye Analysis for predicting signal amplitude, but produced consistent latency errors for the simulated signals examined. Compared to the trained eye, Waveform Similarity Analysis is automatic, objective, does not rely on the observer to identify and/or measure peaks, and can detect small clustered events even when signal-to-noise ratio is poor. Waveform Similarity Analysis provides a simple, reliable and convenient approach to quantify latencies and magnitudes of complex waveforms and therefore serves as a useful tool for studying evoked compound

  7. Elucidation of differential mineralisation on native and regenerated silk matrices. (United States)

    Midha, Swati; Tripathi, Rohit; Geng, Hua; Lee, Peter D; Ghosh, Sourabh


    Bone mineralisation is a well-orchestrated procedure triggered by a protein-based template inducing the nucleation of hydroxyapatite (HA) nanocrystals on the matrix. In an attempt to fabricate superior nanocomposites from silk fibroin, textile braided structures made of natively spun fibres of Bombyx mori silkworm were compared against regenerated fibroin (lyophilized and films) underpinning the influence of intrinsic properties of fibroin matrices on HA nucleation. We found that native braids could bind Ca(2+) ions through electrostatic attraction, which initiated the nucleation and deposition of HA, as evidenced by discrete shift in amide peaks via ATR-FTIR. This phenomenon also suggests the involvement of amide linkages in promoting HA nucleation on fibroin. Moreover, CaCl2-SBF immersion of native braids resulted in preferential growth of HA along the c-axis, forming needle-like nanocrystals and possessing Ca/P ratio comparable to commercial HA. Though regenerated lyophilized matrix also witnessed prominent peak shift in amide linkages, HA growth was restricted to (211) plane only, albeit at a significantly lower intensity than braids. Regenerated films, on the other hand, provided no crystallographic evidence of HA deposition within 7days of SBF immersion. The present work sheds light on the primary fibroin structure of B. mori which probably plays a crucial role in regulating template-induced biomineralisation on the matrix. We also found that intrinsic material properties such as surface roughness, geometry, specific surface area, tortuosity and secondary conformation exert influence in modulating the extent of mineralisation. Thus our work generates useful insights and warrants future studies to further investigate the potential of bone mimetic, silk/mineral nanocomposite matrices for orthopaedic applications.

  8. Molecular approach to echinoderm regeneration. (United States)

    Thorndyke, M C; Chen, W C; Beesley, P W; Patruno, M


    Until very recently echinoderm regeneration research and indeed echinoderm research in general has suffered because of the lack of critical mass. In terms of molecular studies of regeneration, echinoderms in particular have lagged behind other groups in this respect. This is in sharp contrast to the major advances achieved with molecular and genetic techniques in the study of embryonic development in echinoderms. The aim of our studies has been to identify genes involved in the process of regeneration and in particular neural regeneration in different echinoderm species. Our survey included the asteroid Asterias rubens and provided evidence for the expression of Hox gene homologues in regenerating radial nerve cords. Present evidence suggests: 1) ArHox1 expression is maintained in intact radial nerve cord and may be upregulated during regeneration. 2) ArHox1 expression may contribute to the dedifferentiation and/or cell proliferation process during epimorphic regeneration. From the crinoid Antedon bifida, we have been successful in cloning a fragment of a BMP2/4 homologue (AnBMP2/4) and analysing its expression during arm regeneration. Here, we discuss the importance of this family of growth factors in several regulatory spheres, including maintaining the identity of pluripotent blastemal cells or as a classic skeletal morphogenic regulator. There is clearly substantial scope for future echinoderm research in the area of molecular biology and certain aspects are discussed in this review.

  9. Progesterone and peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Fei Fan; Haichao Li; Yuwei Wang; Yanglin Zheng; Lianjun Jia; Zhihui Wang


    OBJECTIVE: To explore the effect of progesterone on peripheral nerve regeneration.DATA SOURCES: An online search of Medline and OVID databases was under taken to identify articles about progesterone and peripheral nerve regeneration published in English between January 1990 and June 2004 by using the keywords of "peripheral nerve, injury, progesterone, regeneration".STUDY SELECTION: The data were primarily screened, those correlated with progesterone and peripheral nerve regeneration were involved, and their original articles were further searched, the repetitive studies or reviews were excluded.DATA EXTRACTION: Totally 59 articles about progesterone and peripheral nerve regeneration were collected, and 26 of them were involved, the other 33 excluded ones were the repetitive studies or reviews.DATA SYNTHESIS: Recent researches found that certain amount of progesterone could be synthetized in peripheral nervous system, and the expression of progesterone receptor could be found in sensory neurons and Schwann cells. After combined with the receptor, endogenous and exogenous progesterone can accelerate the formation of peripheral nerve myelin sheath, also promote the axonal regeneration.CONCLUSION: Progesterone plays a role in protecting neurons, increasing the sensitivity of nerve tissue to nerve growth factor, and accelerating regeneration of nerve in peripheral nerve regeneration, which provides theoretical references for the treatment of demyelinated disease and nerve injury, as well as the prevention of neuroma, especially that the in vivo level of progesterone should be considered for the elderly people accompanied by neuropathy and patients with congenital luteal phase defect, which is of positive significance in guiding the treatment.

  10. Acoustic field modulation in regenerators (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.


    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  11. The Basis of Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Antonio Musarò


    Full Text Available Muscle regeneration recapitulates many aspects of embryonic myogenesis and is an important homeostatic process of the adult skeletal muscle, which, after development, retains the capacity to regenerate in response to appropriate stimuli, activating the muscle compartment of stem cells, namely, satellite cells, as well as other precursor cells. Moreover, significant evidence suggests that while stem cells represent an important determinant for tissue regeneration, a “qualified” environment is necessary to guarantee and achieve functional results. It is therefore plausible that the loss of control over these cell fate decisions could lead to a pathological transdifferentiation, leading to pathologic defects in the regenerative process. This review provides an overview about the general aspects of muscle development and discusses the cellular and molecular aspects that characterize the five interrelated and time-dependent phases of muscle regeneration, namely, degeneration, inflammation, regeneration, remodeling, and maturation/functional repair.

  12. Synthesis of RNA oligomers on heterogeneous templates (United States)

    Ertem, G.; Ferris, J. P.


    The concept of an RNA world in the chemical origin of life is appealing, as nucleic acids are capable of both information storage and acting as templates that catalyse the synthesis of complementary molecules. Template-directed synthesis has been demonstrated for homogeneous oligonucleotides that, like natural nucleic acids, have 3',5' linkages between the nucleotide monomers. But it seems likely that prebiotic routes to RNA-like molecules would have produced heterogeneous molecules with various kinds of phosphodiester linkages and both linear and cyclic nucleotide chains. Here we show that such heterogeneity need be no obstacle to the templating of complementary molecules. Specifically, we show that heterogeneous oligocytidylates, formed by the montmorillonite clay-catalysed condensation of actuated monomers, can serve as templates for the synthesis of oligoguanylates. Furthermore, we show that oligocytidylates that are exclusively 2',5'-linked can also direct synthesis of oligoguanylates. Such heterogeneous templating reactions could have increased the diversity of the pool of protonucleic acids from which life ultimately emerged.

  13. Automated Template Quantification for DNA Sequencing Facilities (United States)

    Ivanetich, Kathryn M.; Yan, Wilson; Wunderlich, Kathleen M.; Weston, Jennifer; Walkup, Ward G.; Simeon, Christian


    The quantification of plasmid DNA by the PicoGreen dye binding assay has been automated, and the effect of quantification of user-submitted templates on DNA sequence quality in a core laboratory has been assessed. The protocol pipets, mixes and reads standards, blanks and up to 88 unknowns, generates a standard curve, and calculates template concentrations. For pUC19 replicates at five concentrations, coefficients of variance were 0.1, and percent errors were from 1% to 7% (n = 198). Standard curves with pUC19 DNA were nonlinear over the 1 to 1733 ng/μL concentration range required to assay the majority (98.7%) of user-submitted templates. Over 35,000 templates have been quantified using the protocol. For 1350 user-submitted plasmids, 87% deviated by ≥ 20% from the requested concentration (500 ng/μL). Based on data from 418 sequencing reactions, quantification of user-submitted templates was shown to significantly improve DNA sequence quality. The protocol is applicable to all types of double-stranded DNA, is unaffected by primer (1 pmol/μL), and is user modifiable. The protocol takes 30 min, saves 1 h of technical time, and costs approximately $0.20 per unknown. PMID:16461949

  14. Injectable silk foams for soft tissue regeneration. (United States)

    Bellas, Evangelia; Lo, Tim J; Fournier, Eric P; Brown, Joseph E; Abbott, Rosalyn D; Gil, Eun S; Marra, Kacey G; Rubin, J Peter; Leisk, Gary G; Kaplan, David L


    Soft tissue fillers are needed for restoration of a defect or augmentation of existing tissues. Autografts and lipotransfer have been under study for soft tissue reconstruction but yield inconsistent results, often with considerable resorption of the grafted tissue. A minimally invasive procedure would reduce scarring and recovery time as well as allow the implant and/or grafted tissue to be placed closer to existing vasculature. Here, the feasibility of an injectable silk foam for soft tissue regeneration is demonstrated. Adipose-derived stem cells survive and migrate through the foam over a 10-d period in vitro. The silk foams are also successfully injected into the subcutaneous space in a rat and over a 3-month period integrating with the surrounding native tissue. The injected foams are palpable and soft to the touch through the skin and returning to their original dimensions after pressure is applied and then released. The foams readily absorb lipoaspirate making the foams useful as a scaffold or template for existing soft tissue filler technologies, useful either as a biomaterial alone or in combination with the lipoaspirate.

  15. A regenerable bitumen composition

    Energy Technology Data Exchange (ETDEWEB)

    Sudzuki, K.; Asakava, Y.; Matsui, A.; Ogava, A.


    The regenerable bitumin composition includes the bitumen material (asphalt, oxidized bitumen, petroleum or asphalt pitch) emulsified by an cation emulsifier (alkylamine or an imidazole derivative) and additionally by a noniononic emulsifier (polyoxyethylenamine), an amide, which contains greater than 1 amide groups per molecule (amide derivative, imidazoline), an epoxide compound with greater than 1 epoxide group per molecule (preferably with an epoxy equivalent of 180 to 500), an inorganic compound which hardens in water (Portland cement or silicate cement) and additionally, water. The total content of the second third components is 1 to 200 parts per million to 100 parts of the first component, while the content of the fourth component is from 1 to 400 parts. The water content in the composition is 5 to 1,000 percent of the total content of the first three components. The patented composition is characterized by high stability, strength, chemical stability, resistance to water and good adhesion properties.

  16. Photon regeneration plans

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.


    Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ''light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment. (orig.)

  17. Photon Regeneration Plans

    CERN Document Server

    Ringwald, A


    Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ``light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment.

  18. Vertex finding with deformable templates at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, N. [European Organization for Nuclear Research, Geneva (Switzerland); Khanov, A. [European Organization for Nuclear Research, Geneva (Switzerland)


    We present a novel vertex finding technique. The task is formulated as a discrete-continuous optimisation problem in a way similar to the deformable templates approach for the track finding. Unlike the track finding problem, ``elastic hedgehogs`` rather than elastic arms are used as deformable templates. They are initialised by a set of procedures which provide zero level approximation for vertex positions and track parameters at the vertex point. The algorithm was evaluated using the simulated events for the LHC CMS detector and demonstrated good performance. (orig.).

  19. Microwave assisted template synthesis of silver nanoparticles

    Indian Academy of Sciences (India)

    K J Sreeram; M Nidhin; B U Nair


    Easier, less time consuming, green processes, which yield silver nanoparticles of uniform size, shape and morphology are of interest. Various methods for synthesis, such as conventional temperature assisted process, controlled reaction at elevated temperatures, and microwave assisted process have been evaluated for the kind of silver nanoparticles synthesized. Starch has been employed as a template and reducing agent. Electron microscopy, photon correlation spectroscopy and surface plasmon resonance have been employed to characterize the silver nanoparticles synthesized. Compared to conventional methods, microwave assisted synthesis was faster and provided particles with an average particle size of 12 nm. Further, the starch functions as template, preventing the aggregation of silver nanoparticles.

  20. Preparation of porous lanthanum phosphate with templates

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Hiroaki, E-mail: [Department of Informatics and Environmental Sciences, Faculty of Life and Environmental Sciences, Kyoto Prefectural University, 1-5, Shimogamo Nakaragi-cyo, Sakyo-ku, Kyoto 606-8522 (Japan); Ishima, Yuya [Department of Applied Chemistry, Faculty of Life Sciences, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Takenaka, Atsushi [Department of Materials Science, Yonago National College of Technology, 4448, Hikona-cho, Yonago, Tottori 683-8502 (Japan); Tanaka, Isao [Department of Materials Science and Engineering, Faculty of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)


    Malonic acid, propionic acid, glycine, n-butylamine, and urea were added to the preparation of lanthanum phosphate from lanthanum nitrate and phosphoric acid solutions. All additives were taken into lanthanum phosphate particles. The additives that have a basic site were easy to contain in precipitates. The addition of templates improved the specific surface area of lanthanum phosphate. The amount of pore, with radius smaller than 4 nm, increased with the addition of templates. The remained additives had influence on the acidic properties of lanthanum phosphate.

  1. Biomaterial selection for tooth regeneration. (United States)

    Yuan, Zhenglin; Nie, Hemin; Wang, Shuang; Lee, Chang Hun; Li, Ang; Fu, Susan Y; Zhou, Hong; Chen, Lili; Mao, Jeremy J


    Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or synthetic polymers, three-dimensional scaffold fabrication, stem cell transplantation, and stem cell homing. A tooth is a complex biological organ. Tooth loss represents the most common organ failure. Tooth regeneration encompasses not only regrowth of an entire tooth as an organ, but also biological restoration of individual components of the tooth including enamel, dentin, cementum, or dental pulp. Regeneration of tooth root represents perhaps more near-term opportunities than the regeneration of the whole tooth. In the adult, a tooth owes its biological vitality, arguably more, to the root than the crown. Biomaterials are indispensible for the regeneration of tooth root, tooth crown, dental pulp, or an entire tooth.

  2. Cardiac Regeneration and Stem Cells. (United States)

    Zhang, Yiqiang; Mignone, John; MacLellan, W Robb


    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world.

  3. The biogeochemical cycle of the adsorbed template. II - Selective adsorption of mononucleotides on adsorbed polynucleotide templates (United States)

    Lazard, Daniel; Lahav, Noam; Orenberg, James B.


    Experimental results are presented for the verification of the specific interaction step of the 'adsorbed template' biogeochemical cycle, a simple model for a primitive prebiotic replication system. The experimental system consisted of gypsum as the mineral to which an oligonucleotide template attaches (Poly-C or Poly-U) and (5-prime)-AMP, (5-prime)-GMP, (5-prime)-CMP and (5-prime)-UMP as the interacting biomonomers. When Poly-C or Poly-U were used as adsorbed templates, (5-prime)-GMP and (5-prime)-AMP, respectively, were observed to be the most strongly adsorbed species.

  4. Controlling monomer-sequence using supramolecular templates


    ten Brummelhuis, Niels


    The transcription and translation of information contained in nucleic acids that has been perfected by nature serves as inspiration for chemists to devise strategies for the creation of polymers with welldefined monomer sequences. In this review the various approaches in which templates (either biopolymers or synthetic ones) are used to influence the monomer-sequence are discussed.

  5. A lightweight approach for biometric template protection (United States)

    Al-Assam, Hisham; Sellahewa, Harin; Jassim, Sabah


    Privacy and security are vital concerns for practical biometric systems. The concept of cancelable or revocable biometrics has been proposed as a solution for biometric template security. Revocable biometric means that biometric templates are no longer fixed over time and could be revoked in the same way as lost or stolen credit cards are. In this paper, we describe a novel and an efficient approach to biometric template protection that meets the revocability property. This scheme can be incorporated into any biometric verification scheme while maintaining, if not improving, the accuracy of the original biometric system. However, we shall demonstrate the result of applying such transforms on face biometric templates and compare the efficiency of our approach with that of the well-known random projection techniques. We shall also present the results of experimental work on recognition accuracy before and after applying the proposed transform on feature vectors that are generated by wavelet transforms. These results are based on experiments conducted on a number of well-known face image databases, e.g. Yale and ORL databases.

  6. Regenerable Contaminant Removal System Project (United States)

    National Aeronautics and Space Administration — The Regenerable Contaminant Removal System (RCRS) is an innovative method to remove sulfur and halide compounds from contaminated gas streams to part-per-billion...

  7. Instructive composites for bone regeneration

    NARCIS (Netherlands)

    Barbieri, D.


    Developing new biomaterials for tissue regeneration requires careful balance between many factors, which is challenging because, on one side, such materials must provide complex information, through their physicochemical properties to actively interact with the biological surroundings and induce tis

  8. Templated Self Assemble of Nano-Structures

    Energy Technology Data Exchange (ETDEWEB)

    Suo, Zhigang [Harvard University


    This project will identify and model mechanisms that template the self-assembly of nanostructures. We focus on a class of systems involving a two-phase monolayer of molecules adsorbed on a solid surface. At a suitably elevated temperature, the molecules diffuse on the surface to reduce the combined free energy of mixing, phase boundary, elastic field, and electrostatic field. With no template, the phases may form a pattern of stripes or disks. The feature size is on the order of 1-100 nm, selected to compromise the phase boundary energy and the long-range elastic or electrostatic interaction. Both experimental observations and our theoretical simulations have shown that the pattern resembles a periodic lattice, but has abundant imperfections. To form a perfect periodic pattern, or a designed aperiodic pattern, one must introduce a template to guide the assembly. For example, a coarse-scale pattern, lithographically defined on the substrate, will guide the assembly of the nanoscale pattern. As another example, if the molecules on the substrate surface carry strong electric dipoles, a charged object, placed in the space above the monolayer, will guide the assembly of the molecular dipoles. In particular, the charged object can be a mask with a designed nanoscale topographic pattern. A serial process (e.g., e-beam lithography) is necessary to make the mask, but the pattern transfer to the molecules on the substrate is a parallel process. The technique is potentially a high throughput, low cost process to pattern a monolayer. The monolayer pattern itself may serve as a template to fabricate a functional structure. This project will model fundamental aspects of these processes, including thermodynamics and kinetics of self-assembly, templated self-assembly, and self-assembly on unconventional substrates. It is envisioned that the theory will not only explain the available experimental observations, but also motivate new experiments.

  9. Tissue engineering for periodontal regeneration. (United States)

    Kao, Richard T; Conte, Greg; Nishimine, Dee; Dault, Scott


    As a result of periodontal regeneration research, a series of clinical techniques have emerged that permit tissue engineering to be performed for more efficient regeneration and repair of periodontal defects and improved implant site development. Historically, periodontal regeneration research has focused on a quest for "magic filler" material. This search has led to the development of techniques utilizing autologous bone and bone marrow, allografts, xenografts, and various man-made bone substitutes. Though these techniques have had limited success, the desire for a more effective regenerative approach has resulted in the development of tissue engineering techniques. Tissue engineering is a relatively new field of reconstructive biology which utilizes mechanical, cellular, or biologic mediators to facilitate reconstruction/regeneration of a particular tissue. In periodontology, the concept of tissue engineering had its beginnings with guided tissue regeneration, a mechanical approach utilizing nonresorbable membranes to obtain regeneration in defects. In dental implantology, guided bone regeneration membranes +/- mechanical support are used for bone augmentation of proposed implant placement sites. With the availability of partially purified protein mixture from developing teeth and growth factors from recombinant technology, a new era of tissue engineering whereby biologic mediators can be used for periodontal regeneration. The advantage of recombinant growth factors is this tissue engineering device is consistent in its regenerative capacity, and variations in regenerative response are due to individual healing response and/or poor surgical techniques. In this article, the authors review how tissue engineering has advanced and discuss its impact on the clinical management of both periodontal and osseous defects in preparation for implant placement. An understanding of these new tissue engineering techniques is essential for comprehending today's ever

  10. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration


    Mahmoud, Ahmed I.; O’Meara, Caitlin C.; Gemberling, Matthew; Zhao, Long; Bryant, Donald M.; Zheng, Ruimao; Gannon, Joseph B.; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F.; Burns, Caroline E.; Burns, C. Geoffrey; MacRae, Calum A.; Poss, Kenneth D.; Lee, Richard T.


    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte...

  11. Review of Research on Template Methods in Preparation of Nanomaterials

    Directory of Open Access Journals (Sweden)

    Yadian Xie


    Full Text Available The nanomaterials have been widely used in various fields, such as photonics, catalysis, and adsorption, because of their unique physical and chemical properties. Therefore, their production methods are of utmost importance. Compared with traditional synthetic methods, the template method can effectively control the morphology, particle size, and structure during the preparation of nanomaterials, which is an effective method for their synthesis. The key for the template method is to choose different templates, which are divided into hard template and soft template according to their different structures. In this paper, the effects of different types of templates on the morphology of nanomaterials during their preparation are investigated from two aspects: hard template and soft template, combined with the mechanism of action.

  12. Emergency department documentation templates: variability in template selection and association with physical examination and test ordering in dizziness presentations

    Directory of Open Access Journals (Sweden)

    Meurer William J


    Full Text Available Abstract Background Clinical documentation systems, such as templates, have been associated with process utilization. The T-System emergency department (ED templates are widely used but lacking are analyses of the templates association with processes. This system is also unique because of the many different template options available, and thus the selection of the template may also be important. We aimed to describe the selection of templates in ED dizziness presentations and to investigate the association between items on templates and process utilization. Methods Dizziness visits were captured from a population-based study of EDs that use documentation templates. Two relevant process outcomes were assessed: head computerized tomography (CT scan and nystagmus examination. Multivariable logistic regression was used to estimate the probability of each outcome for patients who did or did not receive a relevant-item template. Propensity scores were also used to adjust for selection effects. Results The final cohort was 1,485 visits. Thirty-one different templates were used. Use of a template with a head CT item was associated with an increase in the adjusted probability of head CT utilization from 12.2% (95% CI, 8.9%-16.6% to 29.3% (95% CI, 26.0%-32.9%. The adjusted probability of documentation of a nystagmus assessment increased from 12.0% (95%CI, 8.8%-16.2% when a nystagmus-item template was not used to 95.0% (95% CI, 92.8%-96.6% when a nystagmus-item template was used. The associations remained significant after propensity score adjustments. Conclusions Providers use many different templates in dizziness presentations. Important differences exist in the various templates and the template that is used likely impacts process utilization, even though selection may be arbitrary. The optimal design and selection of templates may offer a feasible and effective opportunity to improve care delivery.

  13. Textile-templated electrospun anisotropic scaffolds for regenerative cardiac tissue engineering. (United States)

    Şenel Ayaz, H Gözde; Perets, Anat; Ayaz, Hasan; Gilroy, Kyle D; Govindaraj, Muthu; Brookstein, David; Lelkes, Peter I


    For patients with end-stage heart disease, the access to heart transplantation is limited due to the shortage of donor organs and to the potential for rejection of the donated organ. Therefore, current studies focus on bioengineering approaches for creating biomimetic cardiac patches that will assist in restoring cardiac function, by repairing and/or regenerating the intrinsically anisotropic myocardium. In this paper we present a simplified, straightforward approach for creating bioactive anisotropic cardiac patches, based on a combination of bioengineering and textile-manufacturing techniques in concert with nano-biotechnology based tissue-engineering stratagems. Using knitted conventional textiles, made of cotton or polyester yarns as template targets, we successfully electrospun anisotropic three-dimensional scaffolds from poly(lactic-co-glycolic) acid (PLGA), and thermoplastic polycarbonate-urethane (PCU, Bionate(®)). The surface topography and mechanical properties of textile-templated anisotropic scaffolds significantly differed from those of scaffolds electrospun from the same materials onto conventional 2-D flat-target electrospun scaffolds. Anisotropic textile-templated scaffolds electrospun from both PLGA and PCU, supported the adhesion and proliferation of H9C2 cardiac myoblasts cell line, and guided the cardiac tissue-like anisotropic organization of these cells in vitro. All cell-seeded PCU scaffolds exhibited mechanical properties comparable to those of a human heart, but only the cells on the polyester-templated scaffolds exhibited prolonged spontaneous synchronous contractility on the entire engineered construct for 10 days in vitro at a near physiologic frequency of ∼120 bpm. Taken together, the methods described here take advantage of straightforward established textile manufacturing strategies as an efficient and cost-effective approach to engineering 3D anisotropic, elastomeric PCU scaffolds that can serve as a cardiac patch.

  14. Business Process Variability : A Tool for Declarative Template Design

    NARCIS (Netherlands)

    Bulanov, P.; Groefsema, H.; Aiello, M.


    To lower both implementation time and cost, many Business Process Management tools use process templates to implement highly recurring processes. However, in order for such templates to be used, a process has to adhere substantially to the template. Therefore, current practice for processes which de

  15. Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes

    NARCIS (Netherlands)

    Maijenburg, Albert Wouter


    This thesis is entitled “Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes”. Templated electrodeposition is the synthesis technique that was used throughout this thesis, and it comprises the use of a template with specific shape and dimensions for the forma

  16. Cementum and Periodontal Ligament Regeneration. (United States)

    Menicanin, Danijela; Hynes, K; Han, J; Gronthos, S; Bartold, P M


    The unique anatomy and composition of the periodontium make periodontal tissue healing and regeneration a complex process. Periodontal regeneration aims to recapitulate the crucial stages of wound healing associated with periodontal development in order to restore lost tissues to their original form and function and for regeneration to occur, healing events must progress in an ordered and programmed sequence both temporally and spatially, replicating key developmental events. A number of procedures have been employed to promote true and predictable regeneration of the periodontium. Principally, the approaches are based on the use of graft materials to compensate for the bone loss incurred as a result of periodontal disease, use of barrier membranes for guided tissue regeneration and use of bioactive molecules. More recently, the concept of tissue engineering has been integrated into research and applications of regenerative dentistry, including periodontics, to aim to manage damaged and lost oral tissues, through reconstruction and regeneration of the periodontium and alleviate the shortcomings of more conventional therapeutic options. The essential components for generating effective cellular based therapeutic strategies include a population of multi-potential progenitor cells, presence of signalling molecules/inductive morphogenic signals and a conductive extracellular matrix scaffold or appropriate delivery system. Mesenchymal stem cells are considered suitable candidates for cell-based tissue engineering strategies owing to their extensive expansion rate and potential to differentiate into cells of multiple organs and systems. Mesenchymal stem cells derived from multiple tissue sources have been investigated in pre-clinical animal studies and clinical settings for the treatment and regeneration of the periodontium.

  17. a Low Temperature Regenerator Test Facility (United States)

    Kashani, A.; Helvensteijn, B. P. M.; Feller, J. R.; Salerno, L. J.; Kittel, P.


    Testing regenerators presents an interesting challenge. When incorporated into a cryocooler, a regenerator is intimately coupled to the other components: expander, heat exchangers, and compressor. It is difficult to isolate the performance of any single component. We have developed a low temperature test facility that will allow us to separate the performance of the regenerator from the rest of the cryocooler. The purpose of the facility is the characterization of test regenerators using novel materials and/or geometries in temperature ranges down to 15 K. It consists of the following elements: The test column has two regenerators stacked in series. The coldest stage regenerator is the device under test. The warmer stage regenerator contains a stack of stainless steel screen, a well-characterized material. A commercial cryocooler is used to fix the temperatures at both ends of the test regenerator, cooling both heat exchangers flanging the regenerator stack. Heaters allow varying the temperatures and allow measurement of the remaining cooling power, and thus, regenerator effectiveness. A linear compressor delivers an oscillating pressure to the regenerator assembly. An inertance tube and reservoir provide the proper phase difference between mass flow and pressure. This phase shift, along with the imposed temperature differential, simulates the conditions of the test regenerator when used in an actual pulse tube cryocooler. This paper presents development details of the regenerator test facility, and test results on a second stage, stainless steel screen test regenerator.

  18. Metathesis depolymerization for removable surfactant templates.

    Energy Technology Data Exchange (ETDEWEB)

    Zifer, Thomas (Sandia National Laboratories, Livermore, CA); Wheeler, David Roger; Rahimian, Kamayar; McElhanon, James Ross (Sandia National Laboratories, Livermore, CA); Long, Timothy Michael; Jamison, Gregory Marks; Loy, Douglas Anson (Los Alamos National Laboratories, Los Alamos, NM); Kline, Steven R. (National Institute of Standards and Technology, Gaithersburg, MD); Simmons, Blake Alexander (Sandia National Laboratories, Livermore, CA)


    Current methodologies for the production of meso- and nanoporous materials include the use of a surfactant to produce a self-assembled template around which the material is formed. However, post-production surfactant removal often requires centrifugation, calcination, and/or solvent washing which can damage the initially formed material architecture(s). Surfactants that can be disassembled into easily removable fragments following material preparation would minimize processing damage to the material structure, facilitating formation of templated hybrid architectures. Herein, we describe the design and synthesis of novel cationic and anionic surfactants with regularly spaced unsaturation in their hydrophobic hydrocarbon tails and the first application of ring closing metathesis depolymerization to surfactant degradation resulting in the mild, facile decomposition of these new compounds to produce relatively volatile nonsurface active remnants.

  19. Physical synthesis of quantum circuits using templates (United States)

    Mirkhani, Zahra; Mohammadzadeh, Naser


    Similar to traditional CMOS circuits, quantum circuit design flow is divided into two main processes: logic synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit metrics because of no information sharing between logic synthesis and physical design processes, the concept of " physical synthesis" was introduced for quantum circuit flow, and a few techniques were proposed for it. Following that concept, in this paper a new approach for physical synthesis inspired by template matching idea in quantum logic synthesis is proposed to improve the latency of quantum circuits. Experiments show that by using template matching as a physical synthesis approach, the latency of quantum circuits can be improved by more than 23.55 % on average.

  20. Carbon Nanotube Templated Asembly of Protein

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guodong; Lin, Yuehe


    This paper describes a novel general strategy for fabricating protein-polyion multilayers by electrostatic layer-by-layer (LBL) self-assembly on a carbon nanotube (CNT) template. Such a noncovalent functionalization method is important for preserving the activity of biomolecules and the mechanical and electrical properties of CNTs. Glucose oxidase and poly (diallydimethylammonium) chloride polymer were used as a model to investigate the LBL process on a CNT template. High-resolution transmission electron microscopy and electrochemical characterization confirm the formation of LBL nanostructures on carboxyl functionalized CNTs. We have also demonstrated the applications of these nanoshell bioreactors to the direct electrochemistry of proteins and biosensing. This strategy can be applied to assemble other biological molecules, such as antibodies, antigens, and DNA, for wide bioassay applications.

  1. Multibiometric Systems: Fusion Strategies and Template Security (United States)


    41–44, Toledo , Spain, May 2004. [21] R. Cappelli, A. Lumini, D. Maio, and D. Maltoni. Fingerprint Image Recon- struction From Standard Templates. IEEE...Bowyer, S. Sarkar, and B. Victor . Comparison and Combina- tion of Ear and Face Images in Appearance-based Biometrics. IEEE Transac- tions on Pattern...Chronicles. In Odyssey: The Speaker and Language Recognition Workshop, pages 12–22, Toledo , Spain, May 2004. [157] A. Rakhlin, D. Panchenko, and S

  2. Deep Human Parsing with Active Template Regression. (United States)

    Liang, Xiaodan; Liu, Si; Shen, Xiaohui; Yang, Jianchao; Liu, Luoqi; Dong, Jian; Lin, Liang; Yan, Shuicheng


    In this work, the human parsing task, namely decomposing a human image into semantic fashion/body regions, is formulated as an active template regression (ATR) problem, where the normalized mask of each fashion/body item is expressed as the linear combination of the learned mask templates, and then morphed to a more precise mask with the active shape parameters, including position, scale and visibility of each semantic region. The mask template coefficients and the active shape parameters together can generate the human parsing results, and are thus called the structure outputs for human parsing. The deep Convolutional Neural Network (CNN) is utilized to build the end-to-end relation between the input human image and the structure outputs for human parsing. More specifically, the structure outputs are predicted by two separate networks. The first CNN network is with max-pooling, and designed to predict the template coefficients for each label mask, while the second CNN network is without max-pooling to preserve sensitivity to label mask position and accurately predict the active shape parameters. For a new image, the structure outputs of the two networks are fused to generate the probability of each label for each pixel, and super-pixel smoothing is finally used to refine the human parsing result. Comprehensive evaluations on a large dataset well demonstrate the significant superiority of the ATR framework over other state-of-the-arts for human parsing. In particular, the F1-score reaches 64.38 percent by our ATR framework, significantly higher than 44.76 percent based on the state-of-the-art algorithm [28].

  3. CPU and GPU (Cuda Template Matching Comparison

    Directory of Open Access Journals (Sweden)

    Evaldas Borcovas


    Full Text Available Image processing, computer vision or other complicated opticalinformation processing algorithms require large resources. It isoften desired to execute algorithms in real time. It is hard tofulfill such requirements with single CPU processor. NVidiaproposed CUDA technology enables programmer to use theGPU resources in the computer. Current research was madewith Intel Pentium Dual-Core T4500 2.3 GHz processor with4 GB RAM DDR3 (CPU I, NVidia GeForce GT320M CUDAcompliable graphics card (GPU I and Intel Core I5-2500K3.3 GHz processor with 4 GB RAM DDR3 (CPU II, NVidiaGeForce GTX 560 CUDA compatible graphic card (GPU II.Additional libraries as OpenCV 2.1 and OpenCV 2.4.0 CUDAcompliable were used for the testing. Main test were made withstandard function MatchTemplate from the OpenCV libraries.The algorithm uses a main image and a template. An influenceof these factors was tested. Main image and template have beenresized and the algorithm computing time and performancein Gtpix/s have been measured. According to the informationobtained from the research GPU computing using the hardwarementioned earlier is till 24 times faster when it is processing abig amount of information. When the images are small the performanceof CPU and GPU are not significantly different. Thechoice of the template size makes influence on calculating withCPU. Difference in the computing time between the GPUs canbe explained by the number of cores which they have.

  4. A proposal for a drug information database and text templates for generating package inserts

    Directory of Open Access Journals (Sweden)

    Okuya R


    regenerate the descriptions in the original package insert. In future research, the table schemata and text templates will be extended to regenerate other information in the package inserts. Keywords: medical safety, drug information, package insert, drug database, cluster analysis

  5. Template learning in morphological neural nets (United States)

    Davidson, Jennifer L.; Sun, K.


    This paper presents an application of morphology neural networks to a template learning problem. Morphology neural networks are a nonlinear version of the familiar artificial neural networks. Typically, an artificial neural net is used to solve pattern classification problems One useful characterization of many neural network algorithms is the ability to 'learn' to respond correctly to new data based only on a selection of known data responses. For example, in the multilayer perceptron model, the 'learning' is a procedure whereby parameters are fed back from output to input neurons and the weights changed to give a better response. The morphological neural net in this paper solves a different type of image processing problem. Specifically, given an input image and an output image which corresponds to a dilated version of the input, one would like to determine what template produced the output. The problem corresponds to teaching the network to solve for the weights in a morphological net, as the weights are the template's values. A reasonable method has been investigated for the boolean case; in this paper results are presented for gray scale images. Image algebra has been shown to provide a succinct expression of neural networks algorithms and also to allow a generalization of neural networks, and thus the authors describe the algorithm in image algebra. The remainder of the paper gives a brief discussion of image algebra, the relationship of image algebra and neural networks, a recap of the dilation morphology neural network boolean for boolean images, and the generalization to grayscale data.

  6. Sacrificial template method of fabricating a nanotube (United States)

    Yang, Peidong; He, Rongrui; Goldberger, Joshua; Fan, Rong; Wu, Yi-Ying; Li, Deyu; Majumdar, Arun


    Methods of fabricating uniform nanotubes are described in which nanotubes were synthesized as sheaths over nanowire templates, such as using a chemical vapor deposition process. For example, single-crystalline zinc oxide (ZnO) nanowires are utilized as templates over which gallium nitride (GaN) is epitaxially grown. The ZnO templates are then removed, such as by thermal reduction and evaporation. The completed single-crystalline GaN nanotubes preferably have inner diameters ranging from 30 nm to 200 nm, and wall thicknesses between 5 and 50 nm. Transmission electron microscopy studies show that the resultant nanotubes are single-crystalline with a wurtzite structure, and are oriented along the direction. The present invention exemplifies single-crystalline nanotubes of materials with a non-layered crystal structure. Similar "epitaxial-casting" approaches could be used to produce arrays and single-crystalline nanotubes of other solid materials and semiconductors. Furthermore, the fabrication of multi-sheath nanotubes are described as well as nanotubes having multiple longitudinal segments.

  7. UV NIL template making and imprint evaluation (United States)

    Sasaki, Shiho; Hiraka, Takaaki; Mizuochi, Jun; Sakai, Yuko; Yusa, Satoshi; Morikawa, Yasutaka; Mohri, Hiroshi; Hayashi, Naoya


    UV NIL shows excellent resolution capability with remarkable low line edge roughness, and has been attracting pioneers in the industry who were searching for the finest patterns. We have been focused on the resolution improvement in NIL template making with a 100keV acceleration voltage spot beam EB writer process, and have established a template making process to meet the requirements of the pioneers. Usually such templates needed just a small field (several hundred microns square or so) Now, for several semiconductor devices, the UV NIL is considered not only as a patterning solution for R&D purpose but eventually as a potential candidate for production, and instead of a small field, a full chip field mask is required. Although the 100kV EB writers have excellent resolution capability, they are adopting spot beams (SB) to generate the pattern and have a fatally low throughput if we need full chip writing. In this paper, we are focusing on the 50keV variable shaped beam (VSB) EB writers, which are used in current 4X photomask manufacturing. The 50keV VSB writers can generate full chip pattern in a reasonable time, and by choosing the right patterning material and process, we achieved resolution down to hp28nm, and initial promising results of hp22nm (partial resolution) for line and spaces, and hp26nm for dense holes were observed..

  8. Bone morphogenetic proteins: Periodontal regeneration

    Directory of Open Access Journals (Sweden)

    Subramaniam M Rao


    Full Text Available Periodontitis is an infectious inflammatory disease that results in attachment loss and bone loss. Regeneration of the periodontal tissues entails de novo formation of cementum, periodontal ligament, and alveolar bone. Several different approaches are currently being explored to achieve complete, reliable, and reproducible regeneration of periodontal tissues. The therapeutic management of new bone formation is one of the key issues in successful periodontal regeneration. Bone morphogenetic proteins form a unique group of proteins within the transforming growth factor superfamily of genes and have a vital role in the regulation in the bone induction and maintenance. The activity of bone morphogenetic proteins was first identified in the 1960s, but the proteins responsible for bone induction were unknown until the purification and cloning of human bone morphogenetic proteins in the 1980s, because of their osteoinductive potential. Bone morphogenetic proteins have gained a lot of interest as therapeutic agents for treating periodontal defects. A systematic search for data related to the use of bone morphogenetic proteins for the regeneration of periodontal defects was performed to recognize studies on animals and human (PUBMED, MEDLINE, COCHRANE, and Google search. All the studies included showed noticeable regeneration of periodontal tissues with the use of BMP.

  9. Contemporaryperspective on endogenous myocardial regeneration

    Institute of Scientific and Technical Information of China (English)


    Considering the complex nature of the adult heart,it is no wonder that innate regenerative processes,while maintaining adequate cardiac function, fall shortin myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well asrestricted regeneration. In this review, the backgroundas well as potential mechanisms of endogenousmyocardial regeneration are summarized. We presentand analyze the available evidence in three subsequentsteps. First, we examine the experimental researchdata that provide insights into the mechanisms andorigins of the replicating cardiac myocytes, includingcell populations referred to as cardiac progenitor cells(i.e. , c-kit+ cells). Second, we describe the role ofclinical settings such as acute or chronic myocardialischemia, as initiators of pathways of endogenousmyocardial regeneration. Third, the hitherto conductedclinical studies that examined different approachesof initiating endogenous myocardial regeneration infailing human hearts are analyzed. In conclusion, wepresent the evidence in support of the notion thatregaining cardiac function beyond cellular replacementof dysfunctional myocardium via initiation of innateregenerative pathways could create a new perspectiveand a paradigm change in heart failure therapeutics.Reinitiating cardiac morphogenesis by reintroducingdevelopmental pathways in the adult failing heart mightprovide a feasible way of tissue regeneration. Basedon our hypothesis "embryonic recall", we present firstsupporting evidence on regenerative impulses in themyocardium, as induced by developmental processes.

  10. Converting Basic D3 Charts into Reusable Style Templates. (United States)

    Harper, Jonathan; Agrawala, Maneesh


    We present a technique for converting a basic D3 chart into a reusable style template. Then, given a new data source we can apply the style template to generate a chart that depicts the new data, but in the style of the template. To construct the style template we first deconstruct the input D3 chart to recover its underlying structure: the data, the marks and the mappings that describe how the marks encode the data. We then rank the perceptual effectiveness of the deconstructed mappings. To apply the resulting style template to a new data source we first obtain importance ranks for each new data field. We then adjust the template mappings to depict the source data by matching the most important data fields to the most perceptually effective mappings. We show how the style templates can be applied to source data in the form of either a data table or another D3 chart. While our implementation focuses on generating templates for basic chart types (e.g. variants of bar charts, line charts, dot plots, scatterplots, etc.), these are the most commonly used chart types today. Users can easily find such basic D3 charts on the Web, turn them into templates, and immediately see how their own data would look in the visual style (e.g. colors, shapes, fonts, etc.) of the templates. We demonstrate the effectiveness of our approach by applying a diverse set of style templates to a variety of source datasets.

  11. A Neonatal Bimodal MR-CT Head Template (United States)

    Mohtasebi, Mehrana; Abrishami Moghaddam, Hamid; Grebe, Reinhard; Gity, Masoumeh; Wallois, Fabrice


    Neonatal MR templates are appropriate for brain structural analysis and spatial normalization. However, they do not provide the essential accurate details of cranial bones and fontanels-sutures. Distinctly, CT images provide the best contrast for bone definition and fontanels-sutures. In this paper, we present, for the first time, an approach to create a fully registered bimodal MR-CT head template for neonates with a gestational age of 39 to 42 weeks. Such a template is essential for structural and functional brain studies, which require precise geometry of the head including cranial bones and fontanels-sutures. Due to the special characteristics of the problem (which requires inter-subject inter-modality registration), a two-step intensity-based registration method is proposed to globally and locally align CT images with an available MR template. By applying groupwise registration, the new neonatal CT template is then created in full alignment with the MR template to build a bimodal MR-CT template. The mutual information value between the CT and the MR template is 1.17 which shows their perfect correspondence in the bimodal template. Moreover, the average mutual information value between normalized images and the CT template proposed in this study is 1.24±0.07. Comparing this value with the one reported in a previously published approach (0.63±0.07) demonstrates the better generalization properties of the new created template and the superiority of the proposed method for the creation of CT template in the standard space provided by MR neonatal head template. The neonatal bimodal MR-CT head template is freely downloadable from PMID:28129340

  12. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

    Krag, T O; Hauerslev, S; Jeppesen, T D;


    Mitochondrial myopathies cover a diverse group of disorders in which ragged red and COX-negative fibers are common findings on muscle morphology. In contrast, muscle degeneration and regeneration, typically found in muscular dystrophies, are not considered characteristic features of mitochondrial...... myopathies. We investigated regeneration in muscle biopsies from 61 genetically well-defined patients affected by mitochondrial myopathy. Our results show that the perturbed energy metabolism in mitochondrial myopathies causes ongoing muscle regeneration in a majority of patients, and some were even affected...... by a dystrophic morphology. The results add to the complexity of the pathogenesis underlying mitochondrial myopathies, and expand the knowledge about the impact of energy deficiency on another aspect of muscle structure and function....

  13. Regenerator cross arm seal assembly (United States)

    Jackman, Anthony V.


    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  14. Some principles of regeneration in mammalian systems. (United States)

    Carlson, Bruce M


    This article presents some general principles underlying regenerative phenomena in vertebrates, starting with the epimorphic regeneration of the amphibian limb and continuing with tissue and organ regeneration in mammals. Epimorphic regeneration following limb amputation involves wound healing, followed shortly by a phase of dedifferentiation that leads to the formation of a regeneration blastema. Up to the point of blastema formation, dedifferentiation is guided by unique regenerative pathways, but the overall developmental controls underlying limb formation from the blastema generally recapitulate those of embryonic limb development. Damaged mammalian tissues do not form a blastema. At the cellular level, differentiation follows a pattern close to that seen in the embryo, but at the level of the tissue and organ, regeneration is strongly influenced by conditions inherent in the local environment. In some mammalian systems, such as the liver, parenchymal cells contribute progeny to the regenerate. In others, e.g., skeletal muscle and bone, tissue-specific progenitor cells constitute the main source of regenerating cells. The substrate on which regeneration occurs plays a very important role in determining the course of regeneration. Epimorphic regeneration usually produces an exact replica of the structure that was lost, but in mammalian tissue regeneration the form of the regenerate is largely determined by the mechanical environment acting on the regenerating tissue, and it is normally an imperfect replica of the original. In organ hypertophy, such as that occurring after hepatic resection, the remaining liver mass enlarges, but there is no attempt to restore the original form.

  15. DNA repair by RNA: Templated, or not templated, that is the question. (United States)

    Meers, Chance; Keskin, Havva; Storici, Francesca


    Cells are continuously exposed to both endogenous and exogenous sources of genomic stress. To maintain chromosome stability, a variety of mechanisms have evolved to cope with the multitude of genetic abnormalities that can arise over the life of a cell. Still, failures to repair these lesions are the driving force of cancers and other degenerative disorders. DNA double-strand breaks (DSBs) are among the most toxic genetic lesions, inhibiting cell ability to replicate, and are sites of mutations and chromosomal rearrangements. DSB repair is known to proceed via two major mechanisms: homologous recombination (HR) and non-homologous end joining (NHEJ). HR reliance on the exchange of genetic information between two identical or nearly identical DNA molecules offers increased accuracy. While the preferred substrate for HR in mitotic cells is the sister chromatid, this is limited to the S and G2 phases of the cell cycle. However, abundant amounts of homologous genetic substrate may exist throughout the cell cycle in the form of RNA. Considered an uncommon occurrence, the direct transfer of information from RNA to DNA is thought to be limited to special circumstances. Studies have shown that RNA molecules reverse transcribed into cDNA can be incorporated into DNA at DSB sites via a non-templated mechanism by NHEJ or a templated mechanism by HR. In addition, synthetic RNA molecules can directly template the repair of DSBs in yeast and human cells via an HR mechanism. New work suggests that even endogenous transcript RNA can serve as a homologous template to repair a DSB in chromosomal DNA. In this perspective, we will review and discuss the recent advancements in DSB repair by RNA via non-templated and templated mechanisms. We will provide current findings, models and future challenges investigating RNA and its role in DSB repair.

  16. Temporal regulation of planarian eye regeneration


    Deochand, Michelle E.; Birkholz, Taylor R.; Wendy S Beane


    Abstract While tissue regeneration is typically studied using standard injury models, in nature injuries vary greatly in the amount and location of tissues lost. Planarians have the unique ability to regenerate from many different injuries (including from tiny fragments with no brain), allowing us to study the effects of different injuries on regeneration timelines. We followed the timing of regeneration for one organ, the eye, after multiple injury types that involved tissue loss (single‐ an...

  17. Ear Authentication and Template Protection using Bio-key

    Directory of Open Access Journals (Sweden)

    K. Annapurani


    Full Text Available Biometric authentication is gaining popularity in the current scenario. Biometric based authentication is the science of using physical or behavioral characteristic for ensuring that the person is the claimed identity. Biometric authentication system is also vulnerable to attacks in various phases. The biometric data stored in the template has to be protected, since variety of attacks like circumvent, covert acquisition affects the normal functioning of the system. An attacker may create new biometric data or steal the template or modify the template. Once the biometric template is compromised then the entire system is lost. So securing biometric template is an important aspect in biometric authentication system. In this study ear biometric template is secured by a new method of generating bio key from the ear fused template. Here the transformed template is stored in the database. During verification phase, for the new biometric sample a bio key is generated. Using this bio key the person is authenticated if the transformed feature generated is matched with the stored one. Hence the template is protected with the bio key. The authenticated person alone can access the system, since the key to decrypt the encrypted template is obtained from the ear trait of the authenticated person. FAR and FRR are used to evaluate the system performance.

  18. Deer antler regeneration: cells, concepts, and controversies. (United States)

    Kierdorf, Uwe; Kierdorf, Horst; Szuwart, Thomas


    The periodic replacement of antlers is an exceptional regenerative process in mammals, which in general are unable to regenerate complete body appendages. Antler regeneration has traditionally been viewed as an epimorphic process closely resembling limb regeneration in urodele amphibians, and the terminology of the latter process has also been applied to antler regeneration. More recent studies, however, showed that, unlike urodele limb regeneration, antler regeneration does not involve cell dedifferentiation and the formation of a blastema from these dedifferentiated cells. Rather, these studies suggest that antler regeneration is a stem-cell-based process that depends on the periodic activation of, presumably neural-crest-derived, periosteal stem cells of the distal pedicle. The evidence for this hypothesis is reviewed and as a result, a new concept of antler regeneration as a process of stem-cell-based epimorphic regeneration is proposed that does not involve cell dedifferentiation or transdifferentiation. Antler regeneration illustrates that extensive appendage regeneration in a postnatal mammal can be achieved by a developmental process that differs in several fundamental aspects from limb regeneration in urodeles.

  19. Semiconductor devices for all-optical regeneration

    DEFF Research Database (Denmark)

    Öhman, Filip; Bischoff, Svend; Tromborg, Bjarne


    We review different implementations of semiconductor devices for all-optical regeneration. A general model will be presented for all-optical regeneration in fiber links, taking into consideration the trade-off between non-linearity and noise. Furthermore we discuss a novel regenerator type, based...

  20. All optical regeneration using semiconductor devices

    DEFF Research Database (Denmark)

    Mørk, Jesper; Öhman, Filip; Tromborg, Bjarne

    All-optical regeneration is a key functionality for implementing all-optical networks. We present a simple theory for the bit-error-rate in links employing all-optical regenerators, which elucidates the interplay between the noise and and nonlinearity of the regenerator. A novel device structure ...... is analyzed, emphasizing general aspects of active semiconductor waveguides....

  1. Skeletal muscle development and regeneration.

    NARCIS (Netherlands)

    Grefte, S.; Kuijpers-Jagtman, A.M.; Torensma, R.; Hoff, J.W. Von den


    In the late stages of muscle development, a unique cell population emerges that is a key player in postnatal muscle growth and muscle regeneration. The location of these cells next to the muscle fibers triggers their designation as satellite cells. During the healing of injured muscle tissue, satell

  2. Bone regeneration during distraction osteogenesis

    NARCIS (Netherlands)

    Amir, L.R.; Everts, V.; Bronckers, A.L.J.J.


    Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connec- tive tissues in the gap area between two separated bone segments. This procedure has received much clinical atten- tion as a way to co

  3. Mechanical device for tissue regeneration

    NARCIS (Netherlands)

    Herder, J.L.; Maij, E.


    The invention relates to a mechanical device for tissue- regeneration inside a patient, comprising means (2, 3) to place a scaffold for the tissue under mechanical stress. Said means comprise a first device-part (2) and a second device-part (3) which parts are arranged to be movable with respect to

  4. The Contextualization of Archetypes: Clinical Template Governance. (United States)

    Pedersen, Rune; Ulriksen, Gro-Hilde; Ellingsen, Gunnar


    This paper is a status report from a large-scale openEHR-based EPR project from the North Norway Regional Health Authority. It concerns the standardization of a regional ICT portfolio and the ongoing development of a new process oriented EPR systems encouraged by the unfolding of a national repository for openEHR archetypes. Subject of interest; the contextualization of clinical templates is governed over multiple national boundaries which is complex due to the dependency of clinical resources. From the outset of this, we are interested in how local, regional, and national organizers maneuver to standardize while applying OpenEHR technology.

  5. Progress of UV-NIL template making (United States)

    Hiraka, Takaaki; Mizuochi, Jun; Nakanishi, Yuko; Yusa, Satoshi; Sasaki, Shiho; Morikawa, Yasutaka; Mohri, Hiroshi; Hayashi, Naoya


    Nano-imprint lithography (NIL) has been counted as one of the lithography candidates for hp32nm node and beyond and has showed excellent resolution capability with remarkable low line edge roughness that is attracting many researchers in the industry who were searching for the finest patterning technology. Therefore, recently we have been focusing on the resolution improvement on the NIL templates with the 100keV acceleration voltage spot beam (SB) EB writer and the 50keV acceleration voltage variable shaped beam (VSB) EB writer. The 100keV SB writers have high resolution capability, but they show fatally low throughput if we need full chip writing. Usually templates for resolution pioneers needed just a small field (several hundred microns square or so), but recently requirements for full chip templates are increasing. For full chip writing, we have also started the resolution improvement with the 50keV VSB writers used in current 4X photomask manufacturing. The 50keV VSB writers could generate full chip pattern in a reasonable time though resolution limits are inferior to that with the 100keV SB writers. In this paper, we will show latest results with both the 100keV SB and the 50keV VSB EB writers. With the 100keV SB EB writer, we have achieved down to hp15nm resolution for line and space pattern, but found that to achieve further improvement, an innovation in pattern generation method or material would be inevitable. With the 50keV VSB EB writer, we have achieved down to hp22nm resolution for line and space pattern. Though NIL has excellent resolution capability, solutions for defect inspection and repair are not clearly shown yet. In this paper, we will show preliminary inspection results with an EB inspection tool. We tested an EB inspection tool by Hermes Microvision, Inc. (HMI), which was originally developed for and are currently used as a wafer inspection tool, and now have been started to seek the application for mask use, using a programmed defect

  6. Template-directed porous electrodes in electroanalysis. (United States)

    Walcarius, Alain


    Nano- and/or macrostructuring of electrode surfaces has recently emerged as a powerful method of improving the performances of electrochemical devices by enhancing both molecular accessibility and rapid mass transport via diffusion, by increasing the electroactive surface area in comparison to the geometric one, and/or by providing confinement platforms for hosting suitable reagents. This brief overview highlights how template technology offers advantages in terms of designing new types of porous electrodes-mostly based on thin films, and functionalized or not-and discusses their use in analytical chemistry via some recent examples from the literature on electrochemical sensors and biosensors.

  7. A New Vectorization Technique for Expression Templates in C++

    CERN Document Server

    Progsch, J; Adelmann, A


    Vector operations play an important role in high performance computing and are typically provided by highly optimized libraries that implement the BLAS (Basic Linear Algebra Subprograms) interface. In C++ templates and operator overloading allow the implementation of these vector operations as expression templates which construct custom loops at compile time and providing a more abstract interface. Unfortunately existing expression template libraries lack the performance of fast BLAS(Basic Linear Algebra Subprograms) implementations. This paper presents a new approach - Statically Accelerated Loop Templates (SALT) - to close this performance gap by combining expression templates with an aggressive loop unrolling technique. Benchmarks were conducted using the Intel C++ compiler and GNU Compiler Collection to assess the performance of our library relative to Intel's Math Kernel Library as well as the Eigen template library. The results show that the approach is able to provide optimization comparable to the fas...

  8. Observers change their target template based on expected context. (United States)

    Bravo, Mary J; Farid, Hany


    Previous studies have shown that when observers search repeatedly for a target in a particular context, they may develop a target template that is biased for that context. Because the same target may appear in multiple contexts, we wondered whether observers are able to develop multiple templates for the same target, with each template biased for a particular context. In a series of behavioral experiments, we show that observers can learn multiple target templates for a single target and that they can voluntarily switch among these templates depending on the context they expect to see. Our results suggest that these biased templates may coexist with an unbiased representation of the target, provided they are learned first.

  9. Silicon template preparation for the fabrication of thin patterned gold films via template stripping (United States)

    Schmidl, G.; Dellith, J.; Dellith, A.; Teller, N.; Zopf, D.; Li, G.; Dathe, A.; Mayer, G.; Hübner, U.; Zeisberger, M.; Stranik, O.; Fritzsche, W.


    Metallic nanostructures play an important role in the vast field of modern nanophotonics, which ranges from the life sciences to biomedicine and beyond. Gold is a commonly-used and attractive material for plasmonics in the visible wavelength range, most importantly due to its chemical stability. In the present work, we focused on the different methods of plasmonic nanostructure fabrication that possess the greatest potential for cost-efficient fabrication. Initially, reusable (1 0 0) silicon templates were prepared. For this purpose, three different lithography methods (i.e. e-beam, optical, and nanoparticle lithography) were used that correspond to the desired structural scales. The application of a subsequent anisotropic crystal orientation-dependent wet etching process produced well-defined pyramidal structures in a wide variety of sizes, ranging from several microns to less than 100 nm. Finally, a 200 nm-thick gold layer was deposited by means of confocal sputtering on the silicon templates and stripped in order to obtain gold films that feature a surface replica of the initial template structure. The surface roughness that was achieved on the stripped films corresponds well with the roughness of the template used. This makes it possible to prepare cost-efficient high-quality structured films in large quantities with little effort. The gold films produced were thoroughly characterized, particularly with respect to their plasmonic response.

  10. A nanocluster beacon based on the template transformation of DNA-templated silver nanoclusters. (United States)

    Teng, Ye; Jia, Xiaofang; Zhang, Shan; Zhu, Jinbo; Wang, Erkang


    In this work, we developed a novel light-up nanocluster beacon (NCB) based on shuttling dark silver nanoclusters (NCs) to a bright scaffold through hybridization. The fluorescence enhancement was as high as 70-fold when the two templates were on the opposite sides of the duplexes, enabling sensitive and selective detection of DNA.

  11. Optical Regeneration and Noise in Semiconductor Devices

    DEFF Research Database (Denmark)

    Öhman, Filip


    In this report all-optical 2R-regeneration in optical communication systems is investigated. A simple regenerator device based on concatenated semiconductor optical amplifiers (SOAs) and electro absorbers (EAs) is introduced and examined. Experiments show that the monolithic SOA-EA 2R-regenerator......In this report all-optical 2R-regeneration in optical communication systems is investigated. A simple regenerator device based on concatenated semiconductor optical amplifiers (SOAs) and electro absorbers (EAs) is introduced and examined. Experiments show that the monolithic SOA-EA 2R...

  12. Novel encoding methods for DNA-templated chemical libraries. (United States)

    Li, Gang; Zheng, Wenlu; Liu, Ying; Li, Xiaoyu


    Among various types of DNA-encoded chemical libraries, DNA-templated library takes advantage of the sequence-specificity of DNA hybridization, enabling not only highly effective DNA-templated chemical reactions, but also high fidelity in library encoding. This brief review summarizes recent advances that have been made on the encoding strategies for DNA-templated libraries, and it also highlights their respective advantages and limitations for the preparation of DNA-encoded libraries.

  13. An ice-templated, linearly aligned chitosan-alginate scaffold for neural tissue engineering. (United States)

    Francis, Nicola L; Hunger, Philipp M; Donius, Amalie E; Riblett, Benjamin W; Zavaliangos, Antonios; Wegst, Ulrike G K; Wheatley, Margaret A


    Several strategies have been investigated to enhance axonal regeneration after spinal cord injury, however, the resulting growth can be random and disorganized. Bioengineered scaffolds provide a physical substrate for guidance of regenerating axons towards their targets, and can be produced by freeze casting. This technique involves the controlled directional solidification of an aqueous solution or suspension, resulting in a linearly aligned porous structure caused by ice templating. In this study, freeze casting was used to fabricate porous chitosan-alginate (C/A) scaffolds with longitudinally oriented channels. Chick dorsal root ganglia explants adhered to and extended neurites through the scaffold in parallel alignment with the channel direction. Surface adsorption of a polycation and laminin promoted significantly longer neurite growth than the uncoated scaffold (poly-L-ornithine + Laminin = 793.2 ± 187.2 μm; poly-L-lysine + Laminin = 768.7 ± 241.2 μm; uncoated scaffold = 22.52 ± 50.14 μm) (P < 0.001). The elastic modulus of the hydrated scaffold was determined to be 5.08 ± 0.61 kPa, comparable to reported spinal cord values. The present data suggested that this C/A scaffold is a promising candidate for use as a nerve guidance scaffold, because of its ability to support neuronal attachment and the linearly aligned growth of DRG neurites.

  14. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration. (United States)

    Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T


    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration.

  15. Image Hashes as Templates for Verification

    Energy Technology Data Exchange (ETDEWEB)

    Janik, Tadeusz; Jarman, Kenneth D.; Robinson, Sean M.; Seifert, Allen; McDonald, Benjamin S.; White, Timothy A.


    Imaging systems can provide measurements that confidently assess characteristics of nuclear weapons and dismantled weapon components, and such assessment will be needed in future verification for arms control. Yet imaging is often viewed as too intrusive, raising concern about the ability to protect sensitive information. In particular, the prospect of using image-based templates for verifying the presence or absence of a warhead, or of the declared configuration of fissile material in storage, may be rejected out-of-hand as being too vulnerable to violation of information barrier (IB) principles. Development of a rigorous approach for generating and comparing reduced-information templates from images, and assessing the security, sensitivity, and robustness of verification using such templates, are needed to address these concerns. We discuss our efforts to develop such a rigorous approach based on a combination of image-feature extraction and encryption-utilizing hash functions to confirm proffered declarations, providing strong classified data security while maintaining high confidence for verification. The proposed work is focused on developing secure, robust, tamper-sensitive and automatic techniques that may enable the comparison of non-sensitive hashed image data outside an IB. It is rooted in research on so-called perceptual hash functions for image comparison, at the interface of signal/image processing, pattern recognition, cryptography, and information theory. Such perceptual or robust image hashing—which, strictly speaking, is not truly cryptographic hashing—has extensive application in content authentication and information retrieval, database search, and security assurance. Applying and extending the principles of perceptual hashing to imaging for arms control, we propose techniques that are sensitive to altering, forging and tampering of the imaged object yet robust and tolerant to content-preserving image distortions and noise. Ensuring that the

  16. Guided tissue regeneration. Absorbable barriers. (United States)

    Wang, H L; MacNeil, R L


    Over the past 15 years, techniques aimed at regeneration of lost periodontal tissue have become widely used and accepted in clinical practice. Among these techniques are those which use the principles of guided tissue regeneration (GTR), wherein barriers (i.e., membranes) are used to control cell and tissue repopulation of the periodontal wound. A variety of non-absorbable and absorbable barriers have been developed and used for this purpose, with a trend in recent years toward increased use of absorbable GTR materials. This article describes the evolution of absorbable barrier materials and overview materials available for clinical use today. In addition, advantages and disadvantages of these materials are discussed, as well as possible new developments in barrier-based GTR therapy.

  17. A study on the regeneration performance characteristics of an internally heated regenerator in a liquid desiccant system

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Ji Hyun [Korea University of Science and Technology, Daejeon (Korea, Republic of); Jeon, Dong Soon; Kim, Young Lyoul; Kim, Seon Chang [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of)


    This paper presents a study on the regeneration performance characteristics of an internally heated regenerator applicable to a liquid desiccant system. The internally heated regenerator used in this study was designed and manufactured to provide better regeneration performance. An experimental setup was established to examine the regeneration performance. LiCl aqueous solution was used as working fluid. Variables to evaluate regeneration performance characteristics of the internally heated regenerator were dry bulb temperature, relative humidity and velocity of regeneration air, mass flow rate, temperature and concentration of the LiCl aqueous solution. The experimental conditions were chosen by using a 1/2 fractional factorial DOE. Regeneration rate and regeneration effectiveness were taken as results. From the results, solution concentration and regeneration air relative humidity have strong effects on the regeneration rate. The regeneration effectiveness was affected mostly by regeneration air velocity.

  18. Network Topology Inference from Spectral Templates

    CERN Document Server

    Segarra, Santiago; Mateos, Gonzalo; Ribeiro, Alejandro


    We address the problem of identifying a graph structure from the observation of signals defined on its nodes. Fundamentally, the unknown graph encodes direct relationships between signal elements, which we aim to recover from observable indirect relationships generated by a diffusion process on the graph. The fresh look advocated here permeates benefits from convex optimization and stationarity of graph signals, in order to identify the graph shift operator (a matrix representation of the graph) given only its eigenvectors. These spectral templates can be obtained, e.g., from the sample covariance of independent graph signals diffused on the sought network. The novel idea is to find a graph shift that, while being consistent with the provided spectral information, endows the network with certain desired properties such as sparsity. To that end we develop efficient inference algorithms stemming from provably-tight convex relaxations of natural nonconvex criteria, particularizing the results for two shifts: the...

  19. Using archetypes for defining CDA templates. (United States)

    Moner, David; Moreno, Alberto; Maldonado, José A; Robles, Montserrat; Parra, Carlos


    While HL7 CDA is a widely adopted standard for the documentation of clinical information, the archetype approach proposed by CEN/ISO 13606 and openEHR is gaining recognition as a means of describing domain models and medical knowledge. This paper describes our efforts in combining both standards. Using archetypes as an alternative for defining CDA templates permit new possibilities all based on the formal nature of archetypes and their ability to merge into the same artifact medical knowledge and technical requirements for semantic interoperability of electronic health records. We describe the process followed for the normalization of existing legacy data in a hospital environment, from the importation of the HL7 CDA model into an archetype editor, the definition of CDA archetypes and the application of those archetypes to obtain normalized CDA data instances.

  20. Pattern formation in nanoporous titania templates. (United States)

    Richter, C; Wu, Z; Menon, L


    We have carried out a systematic investigation into the formation of nanoscaled patterns in titania (TiO2) templates under dc anodization of Ti in HF acid. At lower acid concentrations (around 0.5 wt% HF) either pores or tubes form at the surface of anodized titanium foil. The pores or nanotubes are separated from the bottom Ti layer by a thin barrier layer of TiO2. The critical voltage where the transition from pores to tubes occurs has been determined. It is observed that the transition voltage shift towards higher voltages as acid concentration is increased, with pore formation disappearing altogether at high acid concentrations. We have also carried out a systematic investigation into the dependence of pore and tube parameters on the applied dc anodization voltage. Our results indicate that the barrier layer thickness, pore and tube length increase as a function of applied voltage.

  1. Virus Assemblies as Templates for Nanocircuits

    Energy Technology Data Exchange (ETDEWEB)

    James N Culver; Michael T Harris


    The goals of this project were directed at the identification and characterization of bio-mineralization processes and patterning methods for the development of nano scale materials and structures with novel energy and conductive traits. This project utilized a simple plant virus as a model template to investigate methods to attach and coat metals and other inorganic compounds onto biologically based nanotemplates. Accomplishments include: the development of robust biological nanotemplates with enhanced inorganic coating activities; novel coating strategies that allow for the deposition of a continuous inorganic layer onto a bio-nanotemplate even in the absence of a reducing agent; three-dimensional patterning methods for the assemble of nano-featured high aspect ratio surfaces and the demonstrated use of these surfaces in enhancing battery and energy storage applications. Combined results from this project have significantly advanced our understanding and ability to utilize the unique self-assembly properties of biologically based molecules to produce novel materials at the nanoscale level.

  2. Automated spectral classification using template matching

    Institute of Scientific and Technical Information of China (English)

    Fu-Qing Duan; Rong Liu; Ping Guo; Ming-Quan Zhou; Fu-Chao Wu


    An automated spectral classification technique for large sky surveys is pro-posed. We firstly perform spectral line matching to determine redshift candidates for an observed spectrum, and then estimate the spectral class by measuring the similarity be-tween the observed spectrum and the shifted templates for each redshift candidate. As a byproduct of this approach, the spectral redshift can also be obtained with high accuracy. Compared with some approaches based on computerized learning methods in the liter-ature, the proposed approach needs no training, which is time-consuming and sensitive to selection of the training set. Both simulated data and observed spectra are used to test the approach; the results show that the proposed method is efficient, and it can achieve a correct classification rate as high as 92.9%, 97.9% and 98.8% for stars, galaxies and quasars, respectively.

  3. Biologically Inspired Flagella-Templated Silica Nanotubes (United States)

    Jo, Wonjin

    The desire and need for various types of nanostructures have been met with challenges of feasibility, reproducibility, and long fabrication time. To work towards improved bottom-up methods of nanofabrication, bacterial flagella are particularly attractive bio-templates for nanotubes due to their tubular structures and small inner and outer diameters. In this work, flagella isolated from Salmonella typhimurium are used as bio-templates to fabricate silica mineralized nanotubes. The process involves as well-controlled hydrolysis and condensation reaction with aminopropyltriethoxysilane (APTES), followed by the addition of tetraethoxysilane (TEOS). By controlling the concentration of TEOS and the reaction time, a simple and precise method is developed for creating silica-mineralized flagella nanotubes (SMFNs) with various thicknesses of the silica layer. In addition, the SMFNs are further modified to multifunctional nanotubes by coating metal nanoparticles (NPs) or metal oxide NPs such as gold, palladium, and iron oxide. The metallized SMFNs are achieved through reactions including reductive metallization or oxidative hydrolysis. The results from these studies provide evidence for the complete coating of SMFNs with uniform metal NP sizes and high surface area coverage. The metallized SMFNs are found to be electrically conductive along their network structures. The current-voltage characteristics show remarkably improved electrical conductivities depending on the types of metal NPs loading and SMFN networks concentration. The biologically inspired SMFNs with metal loading will allow have controlled electrical properties that can lead to the potential of creating unique and precise nanoelectronic materials. Lastly, the randomly entangled SMFNs are characterized to demonstrate their capabilities for hydrophilic and hydrophobic surface applications.

  4. The Applicability of Interactive Item Templates in Varied Knowledge Types (United States)

    Koong, Chorng-Shiuh; Wu, Chi-Ying


    A well-edited assessment can enhance student's learning motives. Applicability of items, which includes item content and template, plays a crucial role in authoring a good assessment. Templates in discussion contain not only conventional true & false, multiple choice, completion item and short answer but also of those interactive ones. Methods…

  5. Design of a process template for amine synthesis

    DEFF Research Database (Denmark)

    Singh, Ravendra; Godfrey, Andy; Gregertsen, Björn;

    A conceptual nitro reduction process template that should be generic such that it can handle a series of substrates with sim ilar molecular functionality has been designed. The reduction process is based on a continuo us plug-flow slurry reactor. The process template aims at speeding up the process...

  6. Rapid prototyping drill guide template for lumbar pedicle screw placement

    Institute of Scientific and Technical Information of China (English)

    LU Sheng; XU Yong-qing; ZHANG Yuan-zhi; LI Yan-bing; SHI Ji-hong; CHEN Guo-ping; CHEN Yu-bing


    To develop a novel method of spinal pedical stereotaxy by reverse engineering and rapid prototyping techniques, and to validate its accuracy by experimental and clinical studies. Methods: A 3D reconstruction model for the desired lumbar vertebra was generated by using the Mimics 10.11 software, and the optimal screw size and orientation were determined using the reverse engineering software. Afterwards, a drill template was created by reverse engi-neering principle, whose surface was the antitemplate of the vertebral surface. The drill template and its correspond-ing vertebra were manufactured using the rapid prototyping technique. Results: The accuracy of the drill template was con-firmed by drilling screw trajectory into the vertebral biomodel preoperatively. This method also showed its ability to cus-tomize the placement and size of each screw based on the unique morphology of the lumbar vertebra.The drill tem-plate fits the postural surface of the vertebra very well in the cadaver experiment. Postoperative CT scans for controlling the pedicle bore showed that the personalized template had a high precision in cadaver experiment and clinical application. No misplacement occurred by using the per-sonalized template. During surgery, no additional computer assistance was needed.Conclusions: The authors have developed a novel drill template for lumbar pedicle screw placement with good applicability and high accuracy. The potential use of drill templates to place lumbar pedicle screws is promising. Our methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the lumbar spine.

  7. Templation in Noncovalent Synthesis of Hydrogen-Bonded Rosettes

    NARCIS (Netherlands)

    Crego-Calama, Mercedes; Reinhoudt, David N.; Cate, ten Matthijs G.J.; Schalley, Christoph A.; Vögtle, Fritz; Dötz, Karl Heinz


    In this chapter, hydrogen-bonded assemblies based on the rosette motif are used to describe some examples of templation in noncovalent synthesis. After a brief description of the synthesis and characterization of these assemblies, the guest-templated selection and amplification of the strongest bind

  8. Zeta-functions of renormalizable sub-Lorenz templates

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Nuno, E-mail: nmf@uevora.p [CIMA-UE and Department of Mathematics, University of Evora, Rua Romao Ramalho, 59, 7000-671 Evora (Portugal); Silva, Luis, E-mail: lfs@dec.isel.ipl.p [CIMA-UE and Scientific Area of Mathematics, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisboa (Portugal)


    We describe the Williams zeta-functions and the twist zeta-functions of sub-Lorenz templates generated by renormalizable Lorenz maps, in terms of the corresponding zeta-functions of the sub-Lorenz templates generated by the renormalized map and by the map that determines the renormalization type.

  9. Computer-Aided Template for Model Reuse, Development and Maintenance

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul


    A template-based approach for model development is presented in this work. Based on a model decomposition technique, the computer-aided template concept has been developed. This concept is implemented as a software tool , which provides a user-friendly interface for following the workflow steps, ...

  10. A comparison of acetate and digital templating for hip resurfacing. (United States)

    Bracey, Daniel N; Seyler, Thorsten M; Shields, John S; Leng, Xiaoyan; Jinnah, Riyaz H; Lang, Jason E


    This study sought to determine whether templating for metal-on-metal hip resurfacing is more accurate with digital or acetate methodology. The medical records of 102 consecutive patients who underwent hip resurfacing at our institution were retrospectively reviewed. Records lacking preoperative radiographs that included a magnification-establishing marker were excluded, leaving 78 records for study. Two investigators independently prepared acetate and digital templates of the preoperative radiographs, which had been calibrated to 120% magnification, to predict femoral and acetabular component size. Accuracy was measured by comparing the predicted component sizes to the surgically implanted component sizes. Digital templating was more accurate than acetate templating in predicting hip resurfacing component size when measuring accuracy of templates by the absolute error of predicted component sizes (femoral, P hip resurfacing procedures.

  11. Synthesis of 3D ordered porous polystyrene using silica template

    Institute of Scientific and Technical Information of China (English)


    A rigid colloidal silica template was formed by self-assembly ofthe monodispersed silica spheres prepared according to St-ber method. The silica template is highly ordered, which was verified by bright color effect due to Bragg diffraction and the results of SEM. The free radical polymerization of styrene was allowed within the interstices of the rigid template to result in the formation of the three- dimensional periodic silica/polystyrene nano-composites. The titled porous polystyrene was prepared by chemical decom- position of the template with concentrated aqueous hydro- fluoric acid. Scanning electron microscopy characterization showed that the macroporous polystyrene has ordered arrays of the uniform pores replicated from the template. Moreover, it was found that the morphology of the as-synthesized macroporous polystyrene was greatly affected by the connectivity of the silica spheres treated under different conditions.

  12. DNA-templated nickel nanostructures and protein assemblies. (United States)

    Becerril, Hector A; Ludtke, Paul; Willardson, Barry M; Woolley, Adam T


    We report a straightforward method for the fabrication of DNA-templated nickel nanostructures on surfaces. These nickel nanomaterials have potential to be applied as nanowires, as templated catalyst lines, as nanoscale magnetic domains, or in directed protein localization. Indeed, we show here that histidine-tagged phosducin-like protein (His-PhLP) binds with high selectivity to both Ni2+-treated surface DNA and DNA-templated nickel metal to create linear protein assemblies on surfaces. The association of His-PhLP with DNA-templated nickel ions or metal is reversible under appropriate rinsing conditions. Nanoscale DNA-templated protein assemblies might be useful in the construction of high-density protein lines for proteomic analysis, for example. Importantly, these nanofabrication procedures are not limited to linear DNA and can be applied readily to other self-assembled DNA topologies.

  13. Nanostructure templating using low temperature atomic layer deposition (United States)

    Grubbs, Robert K.; Bogart, Gregory R.; Rogers, John A.


    Methods are described for making nanostructures that are mechanically, chemically and thermally stable at desired elevated temperatures, from nanostructure templates having a stability temperature that is less than the desired elevated temperature. The methods comprise depositing by atomic layer deposition (ALD) structural layers that are stable at the desired elevated temperatures, onto a template employing a graded temperature deposition scheme. At least one structural layer is deposited at an initial temperature that is less than or equal to the stability temperature of the template, and subsequent depositions made at incrementally increased deposition temperatures until the desired elevated temperature stability is achieved. Nanostructure templates include three dimensional (3D) polymeric templates having features on the order of 100 nm fabricated by proximity field nanopatterning (PnP) methods.

  14. Assistant template and co-template agents in modeling mesoporous silicas and post-synthesizing organofunctionalizations (United States)

    Oliveira, Vaeudo V.; Airoldi, Claudio


    Mesoporous SBA-16 silicas were synthesized through a direct methodology using the template (F127) combined with co-templates (ethanol and n-butanol), with tetraethylorthosilicate as the silica source. These ordered mesoporous silica were characterized by elemental analyses, infrared spectroscopy, solid-state nuclear magnetic resonance for 13C (CP/MAS) and 29Si (HP/DEC) nuclei, nitrogen sorption/desorption processes, small angle X-ray analyses (SAXS) and transmission electron microscopy (TEM). SAXS and TEM results confirmed the space group Im3m and cubic 3D symmetry, typical for highly ordered SBA-16. The sorption/desorption data for SBA-16 and when functionalized gave type IV isotherms, with hysteresis loop H2. Surface areas of 836; 657 and 618 m2 g-1 and average pore diameters of 7.99; 8.10 and 9.85 nm, for SBA-16A, SBA-16B and SBA-16C were obtained, respectively. When functionalized the silicas presented a reduction in surface area, pore volume and pore diameter due to the pendant chains that interfere with nitrogen sorption in these measurements. The co-template ethanol favors the ordered mesopores with highest wall thicknesses.

  15. Dendrite Injury Triggers DLK-Independent Regeneration

    Directory of Open Access Journals (Sweden)

    Michelle C. Stone


    Full Text Available Axon injury triggers regeneration through activation of a conserved kinase cascade, which includes the dual leucine zipper kinase (DLK. Although dendrites are damaged during stroke, traumatic brain injury, and seizure, it is not known whether mature neurons monitor dendrite injury and initiate regeneration. We probed the response to dendrite damage using model Drosophila neurons. Two larval neuron types regrew dendrites in distinct ways after all dendrites were removed. Dendrite regeneration was also triggered by injury in adults. Next, we tested whether dendrite injury was initiated with the same machinery as axon injury. Surprisingly, DLK, JNK, and fos were dispensable for dendrite regeneration. Moreover, this MAP kinase pathway was not activated by injury to dendrites. Thus, neurons respond to dendrite damage and initiate regeneration without using the conserved DLK cascade that triggers axon regeneration.

  16. Proteomic analysis of zebrafish caudal fin regeneration. (United States)

    Saxena, Sandeep; Singh, Sachin K; Lakshmi, Mula G Meena; Meghah, Vuppalapaty; Bhatti, Bhawna; Swamy, Cherukuvada V Brahmendra; Sundaram, Curam S; Idris, Mohammed M


    The epimorphic regeneration of zebrafish caudal fin is rapid and complete. We have analyzed the biomechanism of zebrafish caudal fin regeneration at various time points based on differential proteomics approaches. The spectrum of proteome changes caused by regeneration were analyzed among controls (0 h) and 1, 12, 24, 48, and 72 h postamputation involving quantitative differential proteomics analysis based on two-dimensional gel electrophoresis matrix-assisted laser desorption/ionization and differential in-gel electrophoresis Orbitrap analysis. A total of 96 proteins were found differentially regulated between the control nonregenerating and regenerating tissues of different time points for having at least 1.5-fold changes. 90 proteins were identified as differentially regulated for regeneration based on differential in-gel electrophoresis analysis between the control and regenerating tissues. 35 proteins were characterized for its expression in all of the five regenerating time points against the control samples. The proteins identified and associated with regeneration were found to be directly allied with various molecular, biological, and cellular functions. Based on network pathway analysis, the identified proteome data set for regeneration was majorly associated in maintaining cellular structure and architecture. Also the proteins were found associated for the cytoskeleton remodeling pathway and cellular immune defense mechanism. The major proteins that were found differentially regulated during zebrafish caudal fin regeneration includes keratin and its 10 isoforms, cofilin 2, annexin a1, skeletal α1 actin, and structural proteins. Annexin A1 was found to be exclusively undergoing phosphorylation during regeneration. The obtained differential proteome and the direct association of the various proteins might lead to a new understanding of the regeneration mechanism.

  17. Mechanisms of platelet-mediated liver regeneration. (United States)

    Lisman, Ton; Porte, Robert J


    Platelets have multiple functions beyond their roles in thrombosis and hemostasis. Platelets support liver regeneration, which is required after partial hepatectomy and acute or chronic liver injury. Although it is widely assumed that platelets stimulate liver regeneration by local excretion of mitogens stored within platelet granules, definitive evidence for this is lacking, and alternative mechanisms deserve consideration. In-depth knowledge of mechanisms of platelet-mediated liver regeneration may lead to new therapeutic strategies to treat patients with failing regenerative responses.

  18. Regeneration: the ultimate example of wound healing. (United States)

    Murawala, Prayag; Tanaka, Elly M; Currie, Joshua D


    The outcome of wound repair in mammals is often characterized by fibrotic scaring. Vertebrates such as zebrafish, frogs, and salamanders not only heal scarlessly, but also can regenerate lost appendages. Decades of study on the process of animal regeneration has produced key insights into the mechanisms of how complex tissue is restored. By examining our current knowledge of regeneration, we can draw parallels with mammalian wound healing to identify the molecular determinants that produce such differing outcomes.

  19. Liver regeneration in nonalcoholic fatty liver disease


    Aldo Lagomarsino


    Steatosis is the accumulation of fat in hepatocytes, which may be the result of liver regeneration or pathological processes such as alcoholic and nonalcoholic fatty liver disease. Despite its importance, in both cases the exact mechanism that prevails in fatty liver regeneration is poorly understood. Previous studies have shown that patients with fatty liver express dispar regeneration, possibly due to the accumulation of reactive oxygen species generated by inflammatory processes caused by ...

  20. Regeneration-associated macrophages: a novel approach to boost intrinsic regenerative capacity for axon regeneration


    Min Jung Kwon; Hyuk Jun Yoon; Byung Gon Kim


    Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord injury. Both intrinsic and extrinsic factors are responsible for the regeneration failure. Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in vivo still remains elusive. Recent experimental evidence has rekindled interests in intrinsic factors for th...

  1. Emerin increase in regenerating muscle fibers

    Directory of Open Access Journals (Sweden)

    S Squarzoni


    Full Text Available The fate of emerin during skeletal muscle regeneration was investigated in an animal model by means of crush injury. Immunofluorescence, immunoblotting and mRNA analysis demonstrated that emerin level is increased in regenerating rat muscle fibers with respect to normal mature myofibers. This finding suggests an involvement of emerin during the muscle fiber regeneration process, in analogy with its reported involvement in muscle cell differentiation in vitro. The impairment of skeletal muscle physiological regeneration or reorganization could be a possible pathogenetic mechanism for Emery Dreifuss muscular dystrophy.

  2. The spark of life: electricity and regeneration. (United States)

    Slack, Jonathan M W


    A recent paper shows that a proton pump, the vacuolar-type adenosine triphosphatase (V-ATPase), is necessary for Xenopus tadpole tail regeneration. The V-ATPase is synthesized in distal cells of the regeneration bud as an early response to amputation, and its role in regeneration is specifically to pump H+ out of cells. Although the downstream effects of proton movement are not known, they may be mediated through changes in membrane potential. This work could reopen a consideration of the role of electric fields in regeneration, an issue that has caused much controversy in the past.

  3. Angiogenesis is inhibitory for mammalian digit regeneration. (United States)

    Yu, Ling; Yan, Mingquan; Simkin, Jennifer; Ketcham, Paulina D; Leininger, Eric; Han, Manjong; Muneoka, Ken


    The regenerating mouse digit tip is a unique model for investigating blastema formation and epimorphic regeneration in mammals. The blastema is characteristically avascular and we previously reported that blastema expression of a known anti-angiogenic factor gene, Pedf, correlated with a successful regenerative response (Yu, L., Han, M., Yan, M., Lee, E. C., Lee, J. & Muneoka, K. (2010). BMP signaling induces digit regeneration in neonatal mice. Development, 137, 551-559). Here we show that during regeneration Vegfa transcripts are not detected in the blastema but are expressed at the onset of differentiation. Treating the amputation wound with vascular endothelial growth factor enhances angiogenesis but inhibits regeneration. We next tested bone morphogenetic protein 9 (BMP9), another known mediator of angiogenesis, and found that BMP9 is also a potent inhibitor of digit tip regeneration. BMP9 induces Vegfa expression in the digit stump suggesting that regenerative failure is mediated by enhanced angiogenesis. Finally, we show that BMP9 inhibition of regeneration is completely rescued by treatment with pigment epithelium-derived factor. These studies show that precocious angiogenesis is inhibitory for regeneration, and provide compelling evidence that the regulation of angiogenesis is a critical factor in designing therapies aimed at stimulating mammalian regeneration.

  4. The Amount of Regenerated Heat Inside the Regenerator of a Stirling Engine

    Directory of Open Access Journals (Sweden)

    J. Škorpík


    Full Text Available The paper deals with analytical computing of the regenerated heat inside the regenerator of a Stirling engine. The total sum of the regenerated heat is constructed as a function of the crank angle in the case of Schmidt’s idealization. 

  5. Early hepatic regeneration index and completeness of regeneration at 6 months after partial hepatectomy

    NARCIS (Netherlands)

    Kele, P. G.; de Boer, M.; van der Jagt, E. J.; Lisman, T.; Porte, R. J.


    Background: The liver is known to regenerate following partial hepatectomy (PH), but little is known about the timing and completeness of regeneration relative to the resected volume. This study examined whether liver volume regeneration following PH and its completeness 6 months after surgery is re

  6. Semiconductor nanowires and templates for electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Ying, Xiang


    This thesis starts by developing a platform for the organized growth of nanowires directly on a planar substrate. For this, a method to fabricate horizontal porous alumina membranes is studied. The second part of the thesis focuses on the study of nanowires. It starts by the understanding of the growth mechanisms of germanium nanowires and follows by the structural and electrical properties at the single nanowire level. Horizontally aligned porous anodic alumina (PAA) was used as a template for the nanowire synthesis. Three PAA arrangements were studied: - high density membranes - micron-sized fingers - multi-contacts Membranes formed by a high density of nanopores were obtained by anodizing aluminum thin films. Metallic and semiconducting nanowires were synthesized into the PAA structures via DC deposition, pulsed electro-depostion and CVD growth. The presence of gold, copper, indium, nickel, tellurium, and silicon nanowires inside PAA templates was verified by SEM and EDX analysis. Further, room-temperature transport measurements showed that the pores are completely filled till the bottom of the pores. In this dissertation, single crystalline and core-shell germanium nanowires are synthesized using indium and bismuth as catalyst in a chemical vapor deposition procedure with germane (GeH{sub 4}) as growth precursor. A systematic growth study has been performed to obtain high aspect-ratio germanium nanowires. The influence of the growth conditions on the final morphology and the crystalline structure has been determined via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). In the case of indium catalyzed germanium nanowires, two different structures were identified: single crystalline and crystalline core-amorphous shell. The preferential growth axis of both kinds of nanowires is along the [110] direction. The occurrence of the two morphologies was found to only depend on the nanowire dimension. In the case of bismuth

  7. Scaffolding Biomaterials for Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    Zhen Cao


    Full Text Available Completely repairing of damaged cartilage is a difficult procedure. In recent years, the use of tissue engineering approach in which scaffolds play a vital role to regenerate cartilage has become a new research field. Investigating the advances in biological cartilage scaffolds has been regarded as the main research direction and has great significance for the construction of artificial cartilage. Native biological materials and synthetic polymeric materials have their advantages and disadvantages. The disadvantages can be overcome through either physical modification or biochemical modification. Additionally, developing composite materials, biomimetic materials, and nanomaterials can make scaffolds acquire better biocompatibility and mechanical adaptability.

  8. Bone regeneration and stem cells

    DEFF Research Database (Denmark)

    Arvidson, K; Abdallah, B M; Applegate, L A


    This invited review covers research areas of central importance for orthopedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and fetal stem cells, effects of sex steroids on mesenchymal stem...... cells, use of platelet rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed....

  9. Synthesis of oligoguanylates on oligocytidylate templates. [on primitive earth (United States)

    Fakhrai, H.; Van Roode, J. H. G.; Orgel, L. E.


    The influence of template length in the self-condensation of guanosine 5'-phosphorimidazole in the presence of oligocytidylate templates is investigated. Reactions were carried out with cyclic cytidine 2',3'-phosphate, oligo- or polyC, and radioactively labeled guanosine 5'-phosphorimidazolide in the presence of Zn(+2) or Pb(+2) catalyst; product yields were determined by paper chromatography, thin-layer chromatography, and high-performance liquid chromatography. In the absence of a catalytic metal or in the presence of Pb(+2), a significant template effect is observed starting with the cytidine dimer and increasing in yield up to the hexamer template. Oligomers longer than the template are observed, and are predominantly 2'-5' linked in the presence of Pb(+2) and of mixed linkages in the uncatalyzed reaction. With the zinc ion as the catalyst, the template effect is first observed with the pentamer and is maximal with the heptamer. Products are predominantly 3'-5', and only a small proportion of them are longer than the template. The importance of the demonstrated formation of molecules with up to 10 guanosine units from oligocytidines as short as the dimer on the primitive earth is noted.

  10. MOCVD epitaxy of InAlN on different templates

    Institute of Scientific and Technical Information of China (English)

    Yun Lijun; Wei Tongbo; Yan Jianchang; Liu Zhe; Wang Junxi; Li Jinmin


    InAlN epilayers were grown on high quality GaN and AlN templates with the same growth parameters.Measurement results showed that two samples had the same In content of ~ 16%,while the crystal quality and surface topography of the InA1N epilayer grown on the AlN template,with 282.3" (002) full width at half maximum (FWHM) of rocking curve,313.5" (102) FWHM,surface roughness of 0.39 nm and V-pit density of 2.8 ×108 cm-2,were better than that of the InAlN epilayer grown on the GaN template,309.3",339.1",0.593 nm and 4.2 × 108 cm-2.A primary conclusion was proposed that both the crystal quality and the surface topography of the InAlN epilayer grown on the AlN template were better than that of the InAlN epilayer grown on the GaN template.Therefore,the AlN template was a better choice than the GaN template for getting high quality InA1N epilayers.

  11. Multimodal biometric approach for cancelable face template generation (United States)

    Paul, Padma Polash; Gavrilova, Marina


    Due to the rapid growth of biometric technology, template protection becomes crucial to secure integrity of the biometric security system and prevent unauthorized access. Cancelable biometrics is emerging as one of the best solutions to secure the biometric identification and verification system. We present a novel technique for robust cancelable template generation algorithm that takes advantage of the multimodal biometric using feature level fusion. Feature level fusion of different facial features is applied to generate the cancelable template. A proposed algorithm based on the multi-fold random projection and fuzzy communication scheme is used for this purpose. In cancelable template generation, one of the main difficulties is keeping interclass variance of the feature. We have found that interclass variations of the features that are lost during multi fold random projection can be recovered using fusion of different feature subsets and projecting in a new feature domain. Applying the multimodal technique in feature level, we enhance the interclass variability hence improving the performance of the system. We have tested the system for classifier fusion for different feature subset and different cancelable template fusion. Experiments have shown that cancelable template improves the performance of the biometric system compared with the original template.

  12. Hand Vein Recognition Based on Improved Template Matching

    Directory of Open Access Journals (Sweden)

    Jun Wang


    Full Text Available An improved template-construction method for hand vein recognition is presented. The accomplishment of the new algorithm involves several steps. First, we design the power-controlled multispectral vein acquisition handset to establish high-quality hand vein database. Second, we propose an improved valley-shaped enhancement operator with NiBlack algorithm to realize vein segmentation. Third, we get a basic-shaped template after dilation and erosion operation in the four neighborhoods firstly, and then we can get the final matching template combining all the shapes after the process of filling the connected region whose threshold is smaller than the one we set according to the experiment effect. Finally we design the hand vein recognition experiments using the designed template and traditional template respectively. The recognition rate of the improved template is 96.6% under the 1:1 mode and 95.75% under the 1:N mode while the recognition rate of the traditional template is 89.2 under the 1:1 mode and 88.2 under the 1:N mode.

  13. Robust structural identification via polyhedral template matching (United States)

    Mahler Larsen, Peter; Schmidt, Søren; Schiøtz, Jakob


    Successful scientific applications of large-scale molecular dynamics often rely on automated methods for identifying the local crystalline structure of condensed phases. Many existing methods for structural identification, such as common neighbour analysis, rely on interatomic distances (or thresholds thereof) to classify atomic structure. As a consequence they are sensitive to strain and thermal displacements, and preprocessing such as quenching or temporal averaging of the atomic positions is necessary to provide reliable identifications. We propose a new method, polyhedral template matching (PTM), which classifies structures according to the topology of the local atomic environment, without any ambiguity in the classification, and with greater reliability than e.g. common neighbour analysis in the presence of thermal fluctuations. We demonstrate that the method can reliably be used to identify structures even in simulations near the melting point, and that it can identify the most common ordered alloy structures as well. In addition, the method makes it easy to identify the local lattice orientation in polycrystalline samples, and to calculate the local strain tensor. An implementation is made available under a Free and Open Source Software license.

  14. Template switching between PNA and RNA oligonucleotides (United States)

    Bohler, C.; Nielsen, P. E.; Orgel, L. E.; Miller, S. L. (Principal Investigator)


    The origin of the RNA world is not easily understood, as effective prebiotic syntheses of the components of RNA, the beta-ribofuranoside-5'-phosphates, are hard to envisage. Recognition of this difficulty has led to the proposal that other genetic systems, the components of which are more easily formed, may have preceded RNA. This raises the question of how transitions between one genetic system and another could occur. Peptide nucleic acid (PNA) resembles RNA in its ability to form double-helical complexes stabilized by Watson-Crick hydrogen bonding between adenine and thymine and between cytosine and guanine, but has a backbone that is held together by amide rather than by phosphodiester bonds. Oligonucleotides bases on RNA are known to act as templates that catalyse the non-enzymatic synthesis of their complements from activated mononucleotides, we now show that RNA oligonucleotides facilitate the synthesis of complementary PNA strands and vice versa. This suggests that a transition between different genetic systems can occur without loss of information.


    Institute of Scientific and Technical Information of China (English)

    Zhong-wei Niu; Dan Li; Zhen-zhong Yang


    The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates to synthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and the layer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm the methodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.

  16. Composition Templates in English Writing of the College Entrance Examination

    Institute of Scientific and Technical Information of China (English)



    In recent years, more and more students relay on universal composition templates. Students believe that the"universal composition template" can cope with all kinds of English tests. How the pros and cons of writing methods seem to put things right once and for all? How’s enlightening significance to English teaching? In this paper, based on the two language acquisition theory and analyze the advantages and disadvantages of the composition template, some suggestion are given to the students to im-prove their English writing level.

  17. Regenerative endodontics: regeneration or repair? (United States)

    Simon, Stéphane R J; Tomson, Phillip L; Berdal, Ariane


    Recent advances in biotechnology and translational research have made it possible to provide treatment modalities that protect the vital pulp, allow manipulation of reactionary and reparative dentinogenesis, and, more recently, permit revascularization of an infected root canal space. These approaches are referred to as regenerative procedures. The method currently used to determine the origin of the tissue secreted during the repair/regeneration process is largely based on the identification of cellular markers (usually proteins) left by cells that were responsible for this tissue production. The presence of these proteins in conjunction with other indicators of cellular behavior (especially biomineralization) and analysis of the structure of the newly generated tissue allow conclusions to be made of how it was formed. Thus far, it has not been possible to truly establish the biological mechanism controlling tertiary dentinogenesis. This article considers current therapeutic techniques to treat the dentin-pulp complex and contextualize them in terms of reparative and regenerative processes. Although it may be considered a semantic argument rather than a biological one, the definitions of regeneration and repair are explored to clarify our position in this era of regenerative endodontics.

  18. Regeneration of Pelargonium in vitro

    Directory of Open Access Journals (Sweden)

    Agnieszka Wojtania


    Full Text Available Pelargonium sp. has been a subject of numerous studies to deterimine the effec tiveness of in vitro techniques to produce a large number of pathogen-free plants. Regeneration of pelargonium plants from the different initial explants as well via organogenesis as via somatic embryogenesis has been obtained. The most effective adventitious shoot formation has been achieved from shoot tips and axillary buds using cytokinin or cytokinin/auxin combinations. Leaf explants, whose general have lower organogenic potency, regenerate better in the presence of thidiazuron. This growth regulator stimulate the somatic embryos production from hypocotyl and cotyledone explants too. The main problem in tissue culture propagation of Pelargonium has been the high tendency to formation of vigorously growing callus with low organogenic potency and rapid senescence of cultures. Moreover, the significant differen ces in requirements to the medium composition (minerals, organic compounds and growth regulators between Pelargonium cultivars has been observed. This makes difficult to develop an universaI method of Pelargonium micropropagation.

  19. Liver Development, Regeneration, and Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Janet W. C. Kung


    Full Text Available The identification of putative liver stem cells has brought closer the previously separate fields of liver development, regeneration, and carcinogenesis. Significant overlaps in the regulation of these processes are now being described. For example, studies in embryonic liver development have already provided the basis for directed differentiation of human embryonic stem cells and induced pluripotent stem cells into hepatocyte-like cells. As a result, the understanding of the cell biology of proliferation and differentiation in the liver has been improved. This knowledge can be used to improve the function of hepatocyte-like cells for drug testing, bioartificial livers, and transplantation. In parallel, the mechanisms regulating cancer cell biology are now clearer, providing fertile soil for novel therapeutic approaches. Recognition of the relationships between development, regeneration, and carcinogenesis, and the increasing evidence for the role of stem cells in all of these areas, has sparked fresh enthusiasm in understanding the underlying molecular mechanisms and has led to new targeted therapies for liver cirrhosis and primary liver cancers.

  20. [Stem cells and cardiac regeneration]. (United States)

    Perez Millan, Maria Ines; Lorenti, Alicia


    Stem cells are defined by virtue of their functional attributes: absence of tissue specific differentitated markers, capable of proliferation, able to self-maintain the population, able to produce a large number of differentiated, functional progeny, able to regenerate the tissue after injury. Cell therapy is an alternative for the treatment of several diseases, like cardiac diseases (cell cardiomyoplasty). A variety of stem cells could be used for cardiac repair: from cardiac and extracardiac sources. Each cell type has its own profile of advantages, limitations, and practicability issues in specific clinical settings. Differentiation of bone marrow stem cells to cardiomyocyte-like cells have been observed under different culture conditions. The presence of resident cardiac stem cell population capable of differentiation into cardiomyocyte or vascular lineage suggests that these cells could be used for cardiac tissue repair, and represent a great promise for clinical application. Stem cells mobilization by cytokines may also offer a strategy for cardiac regeneration. The use of stem cells (embryonic and adult) may hold the key to replacing cells lost in many devastating diseases. This potential benefit is a major focus for stem cell research.

  1. Calcium Signalling and Liver Regeneration

    Directory of Open Access Journals (Sweden)

    Isabelle Garcin


    Full Text Available After partial hepatectomy (PH the initial mass of the organ is restored through a complex network of cellular interactions that orchestrate both proliferative and hepatoprotective signalling cascades. Among agonists involved in this network many of them drive Ca2+ movements. During liver regeneration in the rat, hepatocyte cytosolic Ca2+ signalling has been shown on the one hand to be deeply remodelled and on the other hand to enhance progression of hepatocytes through the cell cycle. Mechanisms through which cytosolic Ca2+ signals impact on hepatocyte cell cycle early after PH are not completely understood, but at least they include regulation of immediate early gene transcription and ERK and CREB phosphorylation. In addition to cytosolic Ca2+, there is also evidence that mitochondrial Ca2+ and also nuclear Ca2+ may be critical for the regulation of liver regeneration. Finally, Ca2+ movements in hepatocytes, and possibly in other liver cells, not only impact hepatocyte progression in the cell cycle but more generally may regulate cellular homeostasis after PH.

  2. Collagen for bone tissue regeneration. (United States)

    Ferreira, Ana Marina; Gentile, Piergiorgio; Chiono, Valeria; Ciardelli, Gianluca


    In the last decades, increased knowledge about the organization, structure and properties of collagen (particularly concerning interactions between cells and collagen-based materials) has inspired scientists and engineers to design innovative collagen-based biomaterials and to develop novel tissue-engineering products. The design of resorbable collagen-based medical implants requires understanding the tissue/organ anatomy and biological function as well as the role of collagen's physicochemical properties and structure in tissue/organ regeneration. Bone is a complex tissue that plays a critical role in diverse metabolic processes mediated by calcium delivery as well as in hematopoiesis whilst maintaining skeleton strength. A wide variety of collagen-based scaffolds have been proposed for different tissue engineering applications. These scaffolds are designed to promote a biological response, such as cell interaction, and to work as artificial biomimetic extracellular matrices that guide tissue regeneration. This paper critically reviews the current understanding of the complex hierarchical structure and properties of native collagen molecules, and describes the scientific challenge of manufacturing collagen-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of innovative techniques for scaffold and material manufacturing that are currently opening the way to the preparation of biomimetic substrates that modulate cell interaction for improved substitution, restoration, retention or enhancement of bone tissue function.

  3. The biogeochemical cycle of the adsorbed template. I - formation of the template (United States)

    Lazard, Daniel; Lahav, Noam; Orenberg, J. B.


    Experimental results are presented for the verification of the first adsorption step of the 'adsorbed template' biogeochemical cycle, a simple model for a primitive prebiotic replication system. The adsorption of Poly-C, Poly-U, Poly-A, Poly-G, and 5'-AMP, 5'-GMP, 5'-CMP and 5'-UMP onto gypsum was studied. It was found that under the conditions of the experiment, the polymers have a very high affinity for the mineral surface, while the monomers adsorb much less efficiently.

  4. Growth Factor Interactions in Bone Regeneration

    NARCIS (Netherlands)

    Kempen, Diederik H. R.; Creemers, Laura B.; Alblas, Jacqueline; Lu, Lichun; Verbout, Abraham J.; Yaszemski, Michael J.; Dhert, Wouter J. A.


    Bone regeneration is a complex process regulated by a large number of bioactive molecules. Many growth factors and cytokines involved in the natural process of bone healing have been identified and tested as potential therapeutic candidates to enhance the regeneration process. Although many of these

  5. Complement components of nerve regeneration conditioned lfuid inlfuence the microenvironment of nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Guang-shuai Li; Qing-feng Li; Ming-min Dong; Tao Zan; Shuang Ding; Lin-bo Liu


    Nerve regeneration conditioned lfuid is secreted by nerve stumps inside a nerve regeneration chamber. A better understanding of the pro-teinogram of nerve regeneration conditioned lfuid can provide evidence for studying the role of the microenvironment in peripheral nerve regeneration. In this study, we used cylindrical silicone tubes as the nerve regeneration chamber model for the repair of injured rat sciatic nerve. Isobaric tags for relative and absolute quantitation proteomics technology and western blot analysis conifrmed that there were more than 10 complement components (complement factor I, C1q-A, C1q-B, C2, C3, C4, C5, C7, C8β and complement factor D) in the nerve regeneration conditioned lfuid and each varied at different time points. These ifndings suggest that all these complement components have a functional role in nerve regeneration.

  6. Complement components of nerve regeneration conditioned fluid influence the microenvironment of nerve regeneration

    Directory of Open Access Journals (Sweden)

    Guang-shuai Li


    Full Text Available Nerve regeneration conditioned fluid is secreted by nerve stumps inside a nerve regeneration chamber. A better understanding of the proteinogram of nerve regeneration conditioned fluid can provide evidence for studying the role of the microenvironment in peripheral nerve regeneration. In this study, we used cylindrical silicone tubes as the nerve regeneration chamber model for the repair of injured rat sciatic nerve. Isobaric tags for relative and absolute quantitation proteomics technology and western blot analysis confirmed that there were more than 10 complement components (complement factor I, C1q-A, C1q-B, C2, C3, C4, C5, C7, C8ß and complement factor D in the nerve regeneration conditioned fluid and each varied at different time points. These findings suggest that all these complement components have a functional role in nerve regeneration.

  7. Current Bioengineering Methods for Whole Kidney Regeneration

    Directory of Open Access Journals (Sweden)

    Shuichiro Yamanaka


    Full Text Available Kidney regeneration is likely to provide an inexhaustible source of tissues and organs for immunosuppression-free transplantation. It is currently garnering considerable attention and might replace kidney dialysis as the ultimate therapeutic strategy for renal failure. However, anatomical complications make kidney regeneration difficult. Here, we review recent advances in the field of kidney regeneration, including (i the directed differentiation of induced pluripotent stem cells/embryonic stem cells into kidney cells; (ii blastocyst decomplementation; (iii use of a decellularized cadaveric scaffold; (iv embryonic organ transplantation; and (v use of a nephrogenic niche for growing xenoembryos for de novo kidney regeneration from stem cells. All these approaches represent potentially promising therapeutic strategies for the treatment of patients with chronic kidney disease. Although many obstacles to kidney regeneration remain, we hope that innovative strategies and reliable research will ultimately allow the restoration of renal function in patients with end-stage kidney disease.

  8. Particulate templates and ordered liquid bridge networks in evaporative lithography. (United States)

    Vakarelski, Ivan U; Kwek, Jin W; Tang, Xiaosong; O'Shea, Sean J; Chan, Derek Y C


    We investigate the properties of latex particle templates required to optimize the development of ordered liquid bridge networks in evaporative lithography. These networks are key precursors in the assembly of solutions of conducting nanoparticles into large, optically transparent, and conducting microwire networks on substrates (Vakarelski, I. U.; Chan, D. Y. C.; Nonoguchi, T.; Shinto, H.; Higashitani, K. Phys. Rev. Lett., 2009, 102, 058303). An appropriate combination of heat treatment and oxygen plasma etching of a close-packed latex particle monolayer is shown to create open-spaced particle templates which facilitates the formation of ordered fully connected liquid bridge networks that are critical to the formation of ordered microwire networks. Similar results can also be achieved if non-close-packed latex particle templates with square or honeycomb geometries are used. The present results have important implications for the development of the particulate templates to control the morphology of functional microwire networks by evaporative lithography.

  9. Statement of Bureau representative [template] [Laguna Atascosa National Wildlife Refuge (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a template used for the statement of the bureau representative and the public hearing for the Laguna Atascosa National Wildlife Refuge Wilderness...

  10. Dental rehabilitation of amelogenesis imperfecta using thermoformed templates. (United States)

    Sockalingam, Snmp


    Amelogenesis imperfecta represents a group of dental developmental conditions that are genomic in origin. Hypoplastic AI, hypomineralised AI or both in combination were the most common types seen clinically. This paper describes oral rehabilitation of a 9-year-old Malay girl with inherited hypoplastic AI using transparent thermoforming templates. The defective surface areas were reconstructed to their original dimensions on stone cast models of the upper and lower arches using composite, and transparent thermoform templates were fabricated on the models. The templates were used as crown formers to reconstruct the defective teeth clinically using esthetically matching composite. The usage of the templates allowed direct light curing of the composite, accurate reproducibility of the anatomic contours of the defective teeth, reduced chair-side time and easy contouring and placement of homogenous thickness of composite in otherwise inaccessible sites of the affected teeth.

  11. A concatenated coding scheme for biometric template protection

    NARCIS (Netherlands)

    Shao, Xiaoying; Xu, Haiyun; Veldhuis, Raymond N.J.; Slump, Cornelis H.


    Cryptography may mitigate the privacy problem in biometric recognition systems. However, cryptography technologies lack error-tolerance and biometric samples cannot be reproduced exactly, rising the robustness problem. The biometric template protection system needs a good feature extraction algorith

  12. Ordered Nanomaterials Thin Films via Supported Anodized Alumina Templates

    Directory of Open Access Journals (Sweden)

    Mohammed eES-SOUNI


    Full Text Available Supported anodized alumina template films with highly ordered porosity are best suited for fabricating large area ordered nanostructures with tunable dimensions and aspect ratios. In this paper we first discuss important issues for the generation of such templates, including required properties of the Al/Ti/Au/Ti thin film heterostructure on a substrate for high quality templates. We then show examples of anisotropic nanostructure films consisting of noble metals using these templates, discuss briefly their optical properties and their applications to molecular detection using surface enhanced Raman spectroscopy. Finally we briefly address the possibility to make nanocomposite films, exemplary shown on a plasmonic-thermochromic nanocomposite of VO2-capped Au-nanorods.

  13. Incorporating User Input in Template-Based Segmentation. (United States)

    Vidal, Camille; Beggs, Dale; Younes, Laurent; Jain, Sanjay K; Jedynak, Bruno


    We present a simple and elegant method to incorporate user input in a template-based segmentation method for diseased organs. The user provides a partial segmentation of the organ of interest, which is used to guide the template towards its target. The user also highlights some elements of the background that should be excluded from the final segmentation. We derive by likelihood maximization a registration algorithm from a simple statistical image model in which the user labels are modeled as Bernoulli random variables. The resulting registration algorithm minimizes the sum of square differences between the binary template and the user labels, while preventing the template from shrinking, and penalizing for the inclusion of background elements into the final segmentation. We assess the performance of the proposed algorithm on synthetic images in which the amount of user annotation is controlled. We demonstrate our algorithm on the segmentation of the lungs of Mycobacterium tuberculosis infected mice from μCT images.

  14. A Survey On Various Web Template Detection And Extraction Methods

    Directory of Open Access Journals (Sweden)

    Neethu Mary Varghese


    Full Text Available Abstract In todays digital world reliance on the World Wide Web as a source of information is extensive. Users increasingly rely on web based search engines to provide accurate search results on a wide range of topics that interest them. The search engines in turn parse the vast repository of web pages searching for relevant information. However majority of web portals are designed using web templates which are designed to provide consistent look and feel to end users. The presence of these templates however can influence search results leading to inaccurate results being delivered to the users. Therefore to improve the accuracy and reliability of search results identification and removal of web templates from the actual content is essential. A wide range of approaches are commonly employed to achieve this and this paper focuses on the study of the various approaches of template detection and extraction that can be applied across homogenous as well as heterogeneous web pages.

  15. Template-Framework Interactions in Tetraethylammonium-Directed Zeolite Synthesis

    NARCIS (Netherlands)

    Schmidt, Joel E.; Fu, Donglong; Deem, Michael W.; Weckhuysen, Bert M.


    Zeolites, having widespread applications in chemical industries, are often synthesized using organic templates. These can be cost-prohibitive, motivating investigations into their role in promoting crystallization. Herein, the relationship between framework structure, chemical composition, synthesis

  16. GPP Webinar: Solar Procurement Templates and Tools for Higher Education (United States)

    Green Power Partnership webinar on solar procurement for Higher Education which features various tools and templates that schools can use to shape and manage the solar procurement process to a successful outcome.

  17. Template matching techniques in computer vision theory and practice

    CERN Document Server

    Brunelli, Roberto


    The detection and recognition of objects in images is a key research topic in the computer vision community.  Within this area, face recognition and interpretation has attracted increasing attention owing to the possibility of unveiling human perception mechanisms, and for the development of practical biometric systems. This book and the accompanying website, focus on template matching, a subset of object recognition techniques of wide applicability, which has proved to be particularly effective for face recognition applications. Using examples from face processing tasks throughout the book to illustrate more general object recognition approaches, Roberto Brunelli: examines the basics of digital image formation, highlighting points critical to the task of template matching;presents basic and  advanced template matching techniques, targeting grey-level images, shapes and point sets;discusses recent pattern classification paradigms from a template matching perspective;illustrates the development of a real fac...

  18. Improving your target-template alignment with MODalign.

    KAUST Repository

    Barbato, Alessandro


    SUMMARY: MODalign is an interactive web-based tool aimed at helping protein structure modelers to inspect and manually modify the alignment between the sequences of a target protein and of its template(s). It interactively computes, displays and, upon modification of the target-template alignment, updates the multiple sequence alignments of the two protein families, their conservation score, secondary structure and solvent accessibility values, and local quality scores of the implied three-dimensional model(s). Although it has been designed to simplify the target-template alignment step in modeling, it is suitable for all cases where a sequence alignment needs to be inspected in the context of other biological information. AVAILABILITY AND IMPLEMENTATION: Freely available on the web at Website implemented in HTML and JavaScript with all major browsers supported. CONTACT:

  19. A generic process template for continuous pharmaceutical production

    DEFF Research Database (Denmark)

    Singh, Ravendra; Rozada-Sanches, Raquel; Dean, William


    In the work reported here, a conceptual generic continuous process template for pharmaceutical production is presented. The template is demonstrated on a nitro reduction case study that should in principle be generic such that it can handle a series of substrates with similar molecular...... for safer operations (from 50 to 100 L in batch or 3 to 5 L in continuous processes). It is shown that the use of the template together with SAM can lead to potential savings in product development times through flexible and efficient production of Kg amounts of product material for clinical trials...... functionality. To assist in adoption of different substrates, a systematic substrate adoption methodology (SAM) has also been developed. The objective of the generic process template together with the SAM is to provide flexibility as well as increased efficiency to continuous processes while reducing inventory...

  20. Alumina Template-Dependant Growth of Cobalt Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    L. Malferrari


    Full Text Available Different electrochemical regimes and porous alumina were applied for template synthesis of cobalt nanowire (nw arrays, revealing several peculiar cases. In contrast to quite uniform filling of sulfuric acid alumina templates by alternating current deposition, nonuniform growth of the Co nw tufts and mushrooms was obtained for the case of oxalic acid templates. We showed herein for the first time that such configurations arise from the spontaneous growth of cobalt nw groups evolving from the cobalt balls at the Al/alumina interface. Nevertheless, the uniform growth of densely packed cobalt nw arrays, up to tens of micrometers in length, was obtained via long-term direct current galvanostatic deposition at low current density using oxalic acid templates one-side coated by conducting layer. The unique point of this regime is the formation of hexagonal lattice Co nws with a preferred (100 growth direction.

  1. Dental rehabilitation of amelogenesis imperfecta using thermoformed templates

    Directory of Open Access Journals (Sweden)

    SNMP Sockalingam


    Full Text Available Amelogenesis imperfecta represents a group of dental developmental conditions that are genomic in origin. Hypoplastic AI, hypomineralised AI or both in combination were the most common types seen clinically. This paper describes oral rehabilitation of a 9-year-old Malay girl with inherited hypoplastic AI using transparent thermoforming templates. The defective surface areas were reconstructed to their original dimensions on stone cast models of the upper and lower arches using composite, and transparent thermoform templates were fabricated on the models. The templates were used as crown formers to reconstruct the defective teeth clinically using esthetically matching composite. The usage of the templates allowed direct light curing of the composite, accurate reproducibility of the anatomic contours of the defective teeth, reduced chair-side time and easy contouring and placement of homogenous thickness of composite in otherwise inaccessible sites of the affected teeth.

  2. [A method for DNA template preparation using a single embryo]. (United States)

    Li, Jun-Feng; Li, Hai-Feng; Song, Yan-Hua; Sun, Yan; Zhang, Jia-Hua


    We established a simple method for the preparation of DNA template from a single oocyte or early embryo by KOH/DTT-Triton X disintegration. The PCR amplification efficiency of DNA template prepared by this method was compared with that prepared by TE-proteinase K. Single oocyte, 2-cell embryo, 8-cell embryo, morula or blastocyst were separately treated by KOH/DTT-Triton X, then the DNA template was directly used to amplify mitochondrial DNA segment by PCR. The overall PCR success rate of the 3 pairs of primers was 100% (70/70), while the overall PCR success rate of single oocyte treated by TE-proteinase K was 92.9% (65/70). Difference between the two results was significant (PDNA template of a single early embryo. It needed only one cycle of PCR amplification to get clear aimed DNA stripe and the efficiency was high enough to meet the need of early embryonic genetic material detection.

  3. The need of appropriate brain SPECT templates for SPM comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Morbelli, S.; Altrinetti, V.; Piccardo, A. [S Martino Univ Hosp, Nucl MedUnit DIMI, I-16132 Genoa (Italy); Rodriguez, G.; Brugnolo, A.; Nobili, F. [S Martino Univ Hosp, Clin Neurophysiol Unit DiSEM, DiTeC, I-16132 Genoa (Italy); Mignone, A. [Osped Riuniti Bergamo, Nucl Med Unit, I-24100 Bergamo (Italy); Pupi, A. [Univ Florence, Nucl Med Unit DFP, Florence (Italy); Koulibaly, P.M. [CEA-Univ Nice Sophia Antipolis, TIRO, Dept Nucl Med, Ctr Antoine Lacassagne, Nice (France)


    Statistical parametric mapping (SPM) is used worldwide to compare brain perfusion single photon emission computed tomography (SPECT) data. The default template within the SPM package used for SPECT image normalization includes images of a group of healthy subjects studied with {sup 99m}TcHMPAO. Since [{sup 99m}Tc] HMPAO and [{sup 99m}Tc] ECD have shown to distribute differently in SPECT studies, we formulated the hypothesis that comparing set of [{sup 99m}Tc]ECD data normalized by means of a [{sup 99m}Tc]HMPAO template may lead to incorrect results. A customized [{sup 99m}Tc]ECD template was built with SPECT and magnetic resonance imaging (MRI) images of 22 neurologically healthy women. Then, two sets of subjects, i.e. a group of patients with very early Alzheimer's disease (eAD) and a matched control group, studied by means of [{sup 99m}Tc]ECD SPECT, were chosen for comparisons. The same statistical approach (t-test between eAD patients and controls and correlation analysis between brain SPECT and a cognitive score) was applied twice, i.e. after normalization with either the default [{sup 99m}Tc]HMPAO template or the customized [{sup 99m}Tc]ECD template. In the comparison between eAD and controls, a cluster of difference in the posterior-cingulate gyrus of both hemispheres was only highlighted when using the customized [{sup 99m}Tc]ECD template, but was missed when using the default [{sup 99m}Tc]HMPAO template. In the correlation between brain perfusion and a cognitive score, the significant cluster was more significant and far more extended, also including the right superior temporal gyrus, using the customized [{sup 99m}Tc]ECD template than using the default [{sup 99m}Tc]HMPAO template. These data suggest the need of customized, radiopharmaceutical-matched SPECT templates to be used within the SPM package. The present customized [{sup 99m}Tc]ECD template is now freely available on the web. (authors)

  4. Multilayered Short Peptide-Alginate Blends as New Materials for Potential Applications in Cartilage Tissue Regeneration. (United States)

    Knoll, Grant A; Romanelli, Steven M; Brown, Alexandra M; Sortino, Rachel M; Banerjee, Ipsita A


    Peptide based nanomaterials have been gaining increased prominence due to their ability to form permeable scaffolds that promote growth and regeneration of new tissue. In this work for the first time a short hexapeptide motif VQIVYK, derived from the Tau protein family was conjugated with an organic polyamine linker, putrescine and utilized as a template for developing new materials for cartilage tissue regeneration. Our results showed that the conjugate formed extensive nanofibrous assemblies upon self-assembly under aqueous conditions. We then employed the layer-by-layer (LBL) approach to design the scaffold by first incorporating a short segment of the dentin sialophosphoprotein motif GDASYNSDESK followed by integration with the peptide sequence GSGAGAGSGAGAGSGAGA. This sequence mimics Ala, Gly, Ser repeats seen in the spider silk protein. We then incorporated the polysaccharide alginate which served as a hydrogel. To further enhance binding interactions with chondrocytes, and promote the formation of cartilage in vitro, the bionanocomposites were then attached to the chondrocyte binding peptide sequence HDSQLEALIKFM. The thermal properties as well as biodegradability of the scaffold was examined. To confirm biocompatibility, we examined cell viability, attachment and morphology in the presence of bovine chondrocytes. The cells were found to efficiently adhere to the scaffolds which formed an intricate mesh mimicking the extracellular matrix of cartilage tissue. To evaluate if differentiation occurred in the presence of the scaffolds, we examined in vitro deposition of proteoglycans. Thus, we have developed a new family of nanoscale scaffolds that may be utilized for cartilage tissue regeneration.

  5. Micro-Nanostructured Polyaniline Assembled in Cellulose Matrix via Interfacial Polymerization for Applications in Nerve Regeneration. (United States)

    Xu, Dingfeng; Fan, Lin; Gao, Lingfeng; Xiong, Yan; Wang, Yanfeng; Ye, Qifa; Yu, Aixi; Dai, Honglian; Yin, Yixia; Cai, Jie; Zhang, Lina


    Conducting polymers have emerged as frontrunners to be alternatives for nerve regeneration, showing a possibility of the application of polyaniline (PANI) as the nerve guidance conduit. In the present work, the cellulose hydrogel was used as template to in situ synthesize PANI via the limited interfacial polymerization method, leading to one conductive side in the polymer. PANI sub-micrometer dendritic particles with mean diameter of ∼300 nm consisting of the PANI nanofibers and nanoparticles were uniformly assembled into the cellulose matrix. The hydrophobic PANI nanoparticles were immobilized in the hydrophilic cellulose via the phytic acid as "bridge" at presence of water through hydrogen bonding interaction. The PANI/cellulose composite hydrogels exhibited good mechanical properties and biocompatibility as well as excellent guiding capacity for the sciatic nerve regeneration of adult Sprague-Dawley rats without any extra treatment. On the basis of the fact that the pure cellulose hydrogel was an inert material for the neural repair, PANI played an indispensable role on the peripheral nerve regeneration. The hierarchical micro-nanostructure and electrical conductivity of PANI could remarkably induce the adhesion and guiding extension of neurons, showing its great potential in biomedical materials.

  6. Track finding with deformable templates — the elastic arms approach (United States)

    Ohlsson, Mattias; Peterson, Carsten; Yuille, Alan L.


    A novel algorithm for particle tracking is presented and evaluated. It is based on deformable templates that converge using a deterministic annealing algorithm. These deformable templates are initialized by Hough transforms. The algorithm, which effectively represents a merger between neuronic decision making and parameter fitting, naturally lends itself to parallel execution. Very good performance is obtained for both non-magnetic and magnetic tracks. For the latter simulated TPC tracks from the CERN DELPHI detector are used.

  7. An Empirical Ultraviolet Iron Spectrum Template Applicable to Active Galaxies

    DEFF Research Database (Denmark)

    Vestergaard, Marianne; Wilkes, B. J.


    Iron emission is often a severe contaminant in optical-ultraviolet spectra of active galaxies. Its presence complicates emission line studies. A viable solution, already successfully applied at optical wavelengths, is to use an empirical iron emission template. We have generated FeII and FeIII te......, including iron transitions. Details of the data processing, generation, and use of the templates, are given by Vestergaard & Wilkes (2001)....

  8. Chemical Strategies for Template Syntheses of Composite Micro and Nanostructures. (United States)


    syntheses can be accomplished within the pores of the alumina templates to make semiconductor tubules (27). Figure 5 shows that Ti02 tubules prepared...surface area forms have higher photo efficiencies (28). Ti02 /conductor nanocomposites may prove to be useful photocatalysts because the template...synthesized Ti02 nanostructures have very high surface areas (27). Furthermore, as discussed previously, each outer tubular Ti02 catalyst particle has

  9. Templating as a Chain of Custody Tool for Arms Control

    Energy Technology Data Exchange (ETDEWEB)

    Benz, Jacob M.; Tanner, Jennifer E.; Duckworth, Leesa L.


    Historically, templates have been considered for use as a treaty accountable item (TAI) authentication tool, alongside item attributes. Because of this, the use of templates has fallen by the wayside due to the perceived intrusiveness of and handling/storage of template data; especially when compared to the negotiability of unclassified attribute threshold values. However, as a chain of custody tool, templates potentially have a large and important role to play in maintaining confidence in the authenticity of the treaty accountable items as they progress through an arms control regime. In general terms, templating is the process of creating a unique, measurable, and repeatable signature which is representative of the TAI. At any point in time, the signature can be re-measured or re-inspected to verify the signature has not changed. Chain of custody is the process by which a controlled boundary is established and maintained around a TAI to both deter and detect unauthorized access to the item. Typically, this is accomplished by putting a tamper indicating device (TID) on the item or container. The TID now acts as a surrogate for the item itself, and is continually checked to ensure the unique identifier and tamper indicating mechanisms have not changed since last inspection. This in and of itself is a form of templating. A stronger template is one that utilizes a signature of the combined item and container. There are many potential signatures which may be exploited, including radiation-, electromagnetic-, and acoustic-based signatures. This paper/presentation will explore the technology and mechanisms in which templating can be applied to create a more robust chain of custody over treaty accountable items as part of a future arms control regime.

  10. Preparation of mesoporous aluminophosphate usingpoly(amido amine) as template

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaofeng; LIN Shen; CHEN Xinqing; CHEN Jiebo; YANG Liuyi; LUO Minghong


    Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier transform infrared spectrometer(FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption/desorption methods.Results show that the title compound exhibits a typical mesoporous structure with the average pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed.

  11. II - Template Metaprogramming for Massively Parallel Scientific Computing - Vectorization with Expression Templates

    CERN Document Server

    CERN. Geneva


    Large scale scientific computing raises questions on different levels ranging from the fomulation of the problems to the choice of the best algorithms and their implementation for a specific platform. There are similarities in these different topics that can be exploited by modern-style C++ template metaprogramming techniques to produce readable, maintainable and generic code. Traditional low-level code tend to be fast but platform-dependent, and it obfuscates the meaning of the algorithm. On the other hand, object-oriented approach is nice to read, but may come with an inherent performance penalty. These lectures aim to present he basics of the Expression Template (ET) idiom which allows us to keep the object-oriented approach without sacrificing performance. We will in particular show to to enhance ET to include SIMD vectorization. We will then introduce techniques for abstracting iteration, and introduce thread-level parallelism for use in heavy data-centric loads. We will show to to apply these methods i...

  12. III - Template Metaprogramming for massively parallel scientific computing - Templates for Iteration; Thread-level Parallelism

    CERN Document Server

    CERN. Geneva


    Large scale scientific computing raises questions on different levels ranging from the fomulation of the problems to the choice of the best algorithms and their implementation for a specific platform. There are similarities in these different topics that can be exploited by modern-style C++ template metaprogramming techniques to produce readable, maintainable and generic code. Traditional low-level code tend to be fast but platform-dependent, and it obfuscates the meaning of the algorithm. On the other hand, object-oriented approach is nice to read, but may come with an inherent performance penalty. These lectures aim to present he basics of the Expression Template (ET) idiom which allows us to keep the object-oriented approach without sacrificing performance. We will in particular show to to enhance ET to include SIMD vectorization. We will then introduce techniques for abstracting iteration, and introduce thread-level parallelism for use in heavy data-centric loads. We will show to to apply these methods i...

  13. Silver nanowires-templated metal oxide for broadband Schottky photodetector (United States)

    Patel, Malkeshkumar; Kim, Hong-Sik; Park, Hyeong-Ho; Kim, Joondong


    Silver nanowires (AgNWs)-templated transparent metal oxide layer was applied for Si Schottky junction device, which remarked the record fastest photoresponse of 3.4 μs. Self-operating AgNWs-templated Schottky photodetector showed broad wavelength photodetection with high responsivity (42.4 A W-1) and detectivity (2.75 × 1015 Jones). AgNWs-templated indium-tin-oxide (ITO) showed band-to-band excitation due to the internal photoemission, resulting in significant carrier collection performances. Functional metal oxide layer was formed by AgNWs-templated from ITO structure. The grown ITO above AgNWs has a cylindrical shape and acts as a thermal protector of AgNWs for high temperature environment without any deformation. We developed thermal stable AgNWs-templated transparent oxide devices and demonstrated the working mechanism of AgNWs-templated Schottky devices. We may propose the high potential of hybrid transparent layer design for various photoelectric applications, including solar cells.

  14. A Geometric Particle Filter for Template-Based Visual Tracking. (United States)

    Junghyun Kwon; Hee Seok Lee; Park, Frank C; Kyoung Mu Lee


    Existing approaches to template-based visual tracking, in which the objective is to continuously estimate the spatial transformation parameters of an object template over video frames, have primarily been based on deterministic optimization, which as is well-known can result in convergence to local optima. To overcome this limitation of the deterministic optimization approach, in this paper we present a novel particle filtering approach to template-based visual tracking. We formulate the problem as a particle filtering problem on matrix Lie groups, specifically the three-dimensional Special Linear group SL(3) and the two-dimensional affine group Aff(2). Computational performance and robustness are enhanced through a number of features: (i) Gaussian importance functions on the groups are iteratively constructed via local linearization; (ii) the inverse formulation of the Jacobian calculation is used; (iii) template resizing is performed; and (iv) parent-child particles are developed and used. Extensive experimental results using challenging video sequences demonstrate the enhanced performance and robustness of our particle filtering-based approach to template-based visual tracking. We also show that our approach outperforms several state-of-the-art template-based visual tracking methods via experiments using the publicly available benchmark data set.

  15. Geometric Templates for Improved Tracking Performance in Monte Carlo Codes (United States)

    Nease, Brian R.; Millman, David L.; Griesheimer, David P.; Gill, Daniel F.


    One of the most fundamental parts of a Monte Carlo code is its geometry kernel. This kernel not only affects particle tracking (i.e., run-time performance), but also shapes how users will input models and collect results for later analyses. A new framework based on geometric templates is proposed that optimizes performance (in terms of tracking speed and memory usage) and simplifies user input for large scale models. While some aspects of this approach currently exist in different Monte Carlo codes, the optimization aspect has not been investigated or applied. If Monte Carlo codes are to be realistically used for full core analysis and design, this type of optimization will be necessary. This paper describes the new approach and the implementation of two template types in MC21: a repeated ellipse template and a box template. Several different models are tested to highlight the performance gains that can be achieved using these templates. Though the exact gains are naturally problem dependent, results show that runtime and memory usage can be significantly reduced when using templates, even as problems reach realistic model sizes.

  16. The Affordance Template ROS Package for Robot Task Programming (United States)

    Hart, Stephen; Dinh, Paul; Hambuchen, Kimberly


    This paper introduces the Affordance Template ROS package for quickly programming, adjusting, and executing robot applications in the ROS RViz environment. This package extends the capabilities of RViz interactive markers by allowing an operator to specify multiple end-effector waypoint locations and grasp poses in object-centric coordinate frames and to adjust these waypoints in order to meet the run-time demands of the task (specifically, object scale and location). The Affordance Template package stores task specifications in a robot-agnostic XML description format such that it is trivial to apply a template to a new robot. As such, the Affordance Template package provides a robot-generic ROS tool appropriate for building semi-autonomous, manipulation-based applications. Affordance Templates were developed by the NASA-JSC DARPA Robotics Challenge (DRC) team and have since successfully been deployed on multiple platforms including the NASA Valkyrie and Robonaut 2 humanoids, the University of Texas Dreamer robot and the Willow Garage PR2. In this paper, the specification and implementation of the affordance template package is introduced and demonstrated through examples for wheel (valve) turning, pick-and-place, and drill grasping, evincing its utility and flexibility for a wide variety of robot applications.

  17. Animal models of skin regeneration. (United States)

    Gawronska-Kozak, Barbara; Grabowska, Anna; Kopcewicz, Marta; Kur, Anna


    Cutaneous injury in the majority of vertebrate animals results in the formation of a scar in the post-injured area. Scar tissues, although beneficial for maintaining integrity of the post-wounded region often interferes with full recovery of injured tissues. The goal of wound-healing studies is to identify mechanisms to redirect reparative pathways from debilitating scar formation to regenerative pathways that lead to normal functionality. To perform such studies models of regeneration, which are rare in mammals, are required. In this review we discussed skin regenerative capabilities present in lower vertebrates and in models of skin scar-free healing in mammals, e.g. mammalian fetuses. However, we especially focused on the attributes of two unusual models of skin scar-free healing capabilities that occur in adult mammals, that is, those associated with nude, FOXN1-deficient mice and in wild-type African spiny mice.

  18. Reintegration of the regenerated and the remaining tissues during joint regeneration in the newt Cynops pyrrhogaster. (United States)

    Tsutsumi, Rio; Inoue, Takeshi; Yamada, Shigehito; Agata, Kiyokazu


    Urodele amphibians, such as newts, can regenerate a functional limb, including joints, after amputation at any level along the proximal-distal axis of the limb. The blastema can regenerate the limb morphology largely independently of the stump after proximal-distal identity has been established, but the remaining and regenerated tissues must be structurally reintegrated (matched in size and shape). Here we used newt joint regeneration as a model to investigate reintegration, because a functionally interlocking joint requires structural integration between its opposing skeletal elements. After forelimbs were amputated at the elbow joint, the joint was regenerated between the remaining and regenerated skeletal elements. The regenerated cartilage was thick around the amputated joint to make a reciprocally interlocking joint structure with the remaining bone. Furthermore, during regeneration, the extracellular matrix of the remaining tissues was lost, suggesting that the remaining tissues might contribute to the morphogenesis of regenerating cartilage. Our results showed that the area of the regenerated cartilage matched the area of the apposed remaining cartilage, thus contributing to formation of a functional structure.

  19. [Tooth regeneration--dream to reality]. (United States)

    Wang, Song-Ling; Wang, Xue-Jiu


    Tooth or dentition missing compromises human health physically and psychiatrically. Although several prosthesis methods are used to restore tooth loss, these restorations are still non-biological methods. It is a dream for human being to regenerate a real tooth for hundreds years. There are two ways to regenerate the tooth. One is application of conventional tissue engineering techniques including seed cells and scaffold. The other is regeneration tooth using dental epithelium and dental mesenchymal cells based on the knowledge of tooth initiation and development. Marked progress has been achieved in these two ways, while there is still a long way to go. Recently a new concept has been proposed for regeneration of a biological tooth root based on tooth-related stem cells and tissue engineering technique. A biological tooth root has been regenerated in swine. It may be a valuable method for restoration of tooth loss before successful whole tooth regeneration. A latest research showed that a subpopulation in bone marrow cells can give rise to ameloblast-like cells when mixed with embryonic epithelium and reassociation with integrated mesenchyme, which may provide a new seed cell source for tooth regeneration.

  20. Regeneration method for condensate desalting device

    Energy Technology Data Exchange (ETDEWEB)

    Tsurumi, Takeshi; Kashimura, Makoto


    Regeneration of a condensate desalting device in a PWR type power plant is conducted by separating a mixed bed into an anion exchange resin layer and a cation exchange resin layer by back washing after stoppage of passage of water. Regeneration of an anion exchange resin layer is conducted by injecting alkali (hydrogen) carbonate such as sodium carbonate and potassium hydrogen carbonate, and extruding them with purified water and then injecting alkali hydroxide, extruding and further washing with purified water. Regeneration of a cation exchange resin layer is conducted by injecting acids such as hydrochloric acid and sulfuric acid followed by extrusion and washing. It is preferable that a liquid formed by mixing the regenerated liquid wastes of the anion exchange resin containing alkali (hydro) carbonate and regenerated liquid wastes of the cationic exchange resin containing acids and allowing generated carbon dioxide to be absorbed to alkali hydroxide is used as alkali (hydrogen) carbonate for the next regeneration. With such procedures, anion exchange resin which adsorbs decomposed products of amines can be regenerated efficiently. (I.N.)

  1. Epoxyeicosanoids promote organ and tissue regeneration. (United States)

    Panigrahy, Dipak; Kalish, Brian T; Huang, Sui; Bielenberg, Diane R; Le, Hau D; Yang, Jun; Edin, Matthew L; Lee, Craig R; Benny, Ofra; Mudge, Dayna K; Butterfield, Catherine E; Mammoto, Akiko; Mammoto, Tadanori; Inceoglu, Bora; Jenkins, Roger L; Simpson, Mary A; Akino, Tomoshige; Lih, Fred B; Tomer, Kenneth B; Ingber, Donald E; Hammock, Bruce D; Falck, John R; Manthati, Vijaya L; Kaipainen, Arja; D'Amore, Patricia A; Puder, Mark; Zeldin, Darryl C; Kieran, Mark W


    Epoxyeicosatrienoic acids (EETs), lipid mediators produced by cytochrome P450 epoxygenases, regulate inflammation, angiogenesis, and vascular tone. Despite pleiotropic effects on cells, the role of these epoxyeicosanoids in normal organ and tissue regeneration remains unknown. EETs are produced predominantly in the endothelium. Normal organ and tissue regeneration require an active paracrine role of the microvascular endothelium, which in turn depends on angiogenic growth factors. Thus, we hypothesize that endothelial cells stimulate organ and tissue regeneration via production of bioactive EETs. To determine whether endothelial-derived EETs affect physiologic tissue growth in vivo, we used genetic and pharmacological tools to manipulate endogenous EET levels. We show that endothelial-derived EETs play a critical role in accelerating tissue growth in vivo, including liver regeneration, kidney compensatory growth, lung compensatory growth, wound healing, corneal neovascularization, and retinal vascularization. Administration of synthetic EETs recapitulated these results, whereas lowering EET levels, either genetically or pharmacologically, delayed tissue regeneration, demonstrating that pharmacological modulation of EETs can affect normal organ and tissue growth. We also show that soluble epoxide hydrolase inhibitors, which elevate endogenous EET levels, promote liver and lung regeneration. Thus, our observations indicate a central role for EETs in organ and tissue regeneration and their contribution to tissue homeostasis.

  2. Guided bone regeneration using individualized ceramic sheets. (United States)

    Malmström, J; Anderud, J; Abrahamsson, P; Wälivaara, D-Å; Isaksson, S G; Adolfsson, E


    Guided bone regeneration (GBR) describes the use of membranes to regenerate bony defects. A membrane for GBR needs to be biocompatible, cell-occlusive, non-toxic, and mouldable, and possess space-maintaining properties including stability. The purpose of this pilot study was to describe a new method of GBR using individualized ceramic sheets to perfect bone regeneration prior to implant placement; bone regeneration was assessed using traditional histology and three-dimensional (3D) volumetric changes in the bone and soft tissue. Three patients were included. After full-thickness flap reflection, the individualized ceramic sheets were fixed. The sites were left to heal for 7 months. All patients were evaluated preoperatively and at 7 months postoperative using cone beam computed tomography and 3D optical equipment. Samples of the regenerated bone and soft tissue were collected and analyzed. The bone regenerated in the entire interior volume of all sheets. Bone biopsies revealed newly formed trabecular bone with a lamellar structure. Soft tissue biopsies showed connective tissue with no signs of an inflammatory response. This was considered to be newly formed periosteum. Thus ceramic individualized sheets can be used to regenerate large volumes of bone in both vertical and horizontal directions independent of the bone defect and with good biological acceptance of the material.

  3. Anatomical standardization of small animal brain FDG-PET images using synthetic functional template: experimental comparison with anatomical template. (United States)

    Coello, Christopher; Hjornevik, Trine; Courivaud, Frédéric; Willoch, Frode


    Anatomical standardization (also called spatial normalization) of positron emission tomography (PET) small animal brain images is required to make statistical comparisons across individuals. Frequently, PET images are co-registered to an individual MR or CT image of the same subject in order to transform the functional images to an anatomical space. In the present work, we evaluate the normalization of synthetic PET (synPET) images to a synthetic PET template. To provide absolute error in terms of pixel misregistration, we created a synthetic PET image from the individual MR image through segmentation of the brain into gray and white matter which produced functional and anatomical images in the same space. When comparing spatial normalization of synPET images to a synPET template with the gold standard (MR images to an MR template), a mean translation error of 0.24mm (±0.20) and a maximal mean rotational error of 0.85° (±0.91) were found. Significant decrease in misregistration error was measured when achieving spatial normalization of functional images to a functional template instead of an anatomical template. This accuracy strengthens the use of standardization methods where individual PET images are registered to a customized PET template in order to statistically assess physiological changes in rat brains.

  4. Pulp Regeneration: Current Approaches and Future Challenges (United States)

    Yang, Jingwen; Yuan, Guohua; Chen, Zhi


    Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α), basic Fibroblast Growth Factor (bFGF), Platelet Derived Growth Factor (PDGF), stem cell factor (SCF), and Granulocyte Colony-Stimulating Factor (G-CSF) were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration. PMID:27014076

  5. Pulp regeneration: Current approaches and future challenges

    Directory of Open Access Journals (Sweden)

    Jingwen eYANG


    Full Text Available Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α, basic Fibroblast Growth Factor (bFGF, Platelet Derived Growth Factor (PDGF, stem cell factor (SCF, and Granulocyte Colony-Stimulating Factor (G-CSF were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration.

  6. Intrinsic determinants of optic nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    ZHU Rui-lin; CHO Kin-Sang; GUO Chen-ying; CHEW Justin; CHEN Dong-feng; YANG Liu


    Objective To review the functions of these intracellular signals in their regulation of retinal ganglion cell (RGC) axon regeneration.Data sources Relevant articles published in English or Chinese from 1970 to present were selected from PubMed.Searches were made using the terms "intrinsic determinants,axon regeneration,RGC,optic nerve regeneration,and central nervous system axon regeneration."Study selection Articles studying the mechanisms controlling RGC and central nervous system (CNS) axon regeneration were reviewed.Articles focusing on the intrinsic determinants of axon regeneration were selected.Results Like other CNS neurons of mammals,RGCs undergo a developmental loss in their ability to grow axons as they mature,which is a critical contributing factor to the failure of nerve regeneration and repair after injury.This growth failure can be attributed,at least in part,by the induction of molecular programs preventing cellular overgrowth and termination of axonal growth upon maturation.Key intracellular signals and transcription factors,including B cell lymphoma/leukemia 2,cyclic adenine monophosphate,mammalian target of rapamycin,and Krüppel-like transcription factors,have been identified to play central roles in this process.Conclusions Intense effort and substantial progress have been made to identify the various intrinsic growth pathways that regulate RGC axon regeneration.More work is needed to elucidate the mechanisms of and the interrelationship between the actions of these factors and to successfully achieve regeneration and repair of the severed RGC axons.

  7. Nanoparticle Array Assembly Using Chemical Templates (United States)

    Adams, Sarah Marie

    This dissertation demonstrates chemically-driven self-assembly techniques to produce assemblies of closely-spaced metal nanoparticles from colloidal nanoparticle solution in order to engineer enhanced optical fields. Planar nanoparticle assemblies provide a platform for a multitude of applications and material architectures. With nanoscale inter-particle spacing, metallic nanoparticles enable increased efficiency of photovoltaic devices due to light focusing and enhancement of electromagnetic fields useful for optical sensing of molecules due to coupling of the plasmon resonance in nanoparticle gaps. For molecular sensors, development of self-assembled two-dimensional assemblies of closely-spaced nanoparticles is useful for producing surface plasmon resonance sensors and surface-enhanced Raman spectroscopy (SERS) based sensing. Using chemical self-assembly, monodisperse, colloidal gold nanoparticles were attached on self-organized polymer templates in order to pattern assemblies of nanoparticle clusters with sub-10 nanometer inter-particle spacing. First citrate-stabilized Au nanoparticles were functionalized with thioctic acid ligands in solution. Then poly(methyl methacrylate) domains in phase-separated poly(styrene-block-methyl methacrylate) (PS-b-PMMA) thin films were chemically modified with surface amine functional groups. Au nanoparticles were preferentially attached to the functionalized PMMA surface domains using cross-linking chemistry. This method allows for versatility of size, shape, and composition. In this dissertation, we demonstrated attachment of 5, 10, and 20 nm Au and 20 nm Ag nanoparticles. PS-b-PMMA thin films also exhibit versatility of domain size and morphology by varying polymer molecular weights. The nanoparticle diameter to PMMA domain size ratio influenced the cluster size. As the ratio decreased, larger clusters were observed on PMMA domains with increased frequency. SERS measurement of nanoparticle assemblies showed uniform signal

  8. Chitosan Conduit for Peripheral Nerve Regeneration

    Institute of Scientific and Technical Information of China (English)


    Chitosan, the N-deacetylated form of chitin, has good biocompatibility and biodegradability.This paper investigates the feasibility of using chitosan conduits for peripheral nerve regeneration.Cell culture experiments were used to test the material's cytotoxicity and affinity to nerve cells.Conduit implantation experiments were used to study the degradation of the material and the regeneration of injured sciatic nerves.The primary results indicate that chitosan has good mechanical properties, biocompatibility, and biodegradability and it may be a promising biomaterial for peripheral nerve regeneration.

  9. Reparative inflammation takes charge of tissue regeneration. (United States)

    Karin, Michael; Clevers, Hans


    Inflammation underlies many chronic and degenerative diseases, but it also mitigates infections, clears damaged cells and initiates tissue repair. Many of the mechanisms that link inflammation to damage repair and regeneration in mammals are conserved in lower organisms, indicating that it is an evolutionarily important process. Recent insights have shed light on the cellular and molecular processes through which conventional inflammatory cytokines and Wnt factors control mammalian tissue repair and regeneration. This is particularly important for regeneration in the gastrointestinal system, especially for intestine and liver tissues in which aberrant and deregulated repair results in severe pathologies.

  10. Gelatin Based Skin Regenerative Template: Market Research and Product Analysis


    Reddy, Arjun G


    Skin regeneration and wound management in the Bio-Pharma industry has been an area with constant research and new product development. The range of products includes foams, sheets, sprays, powders, hydrocolloids and gels. Majority of these products that exist in the market are collagen based products. However, using collagen products is very expensive and could also have long term risks on patient’s health. Furthermore, they do not regenerate the skin to its original shape and texture and thu...

  11. fgf20 is essential for initiating zebrafish fin regeneration. (United States)

    Whitehead, Geoffrey G; Makino, Shinji; Lien, Ching-Ling; Keating, Mark T


    Epimorphic regeneration requires the presence or creation of pluripotent cells capable of reproducing lost organs. Zebrafish fin regeneration is mediated by the creation of blastema cells. Here, we characterize the devoid of blastema (dob) mutant that fails fin regeneration during initial steps, forms abnormal regeneration epithelium, and does not form blastema. This mutation has no impact on embryonic survival. Dob results from an fgf20a null mutation, Y148S. Fgf20a is expressed during initiation of fin regeneration at the epithelial-mesenchymal boundary and later overlaps with the blastema marker msxb. Thus, fgf20a has a regeneration-specific requirement, initiating fin regeneration, and controlling blastema formation.

  12. Muscle regeneration in amphibians and mammals: passing the torch. (United States)

    Carlson, Bruce M


    Skeletal muscle in both amphibians and mammals possesses a high regenerative capacity. In amphibians, a muscle can regenerate in two distinct ways: as a tissue component of an entire regenerating limb (epimorphic regeneration) or as an isolated entity (tissue regeneration). In the absence of epimorphic regenerative ability, mammals can regenerate muscles only by the tissue mode. This review focuses principally on the regeneration of entire muscles and covers what is known and what remains to be elucidated about fundamental mechanisms underlying muscle regeneration at this level.

  13. Production and characterization of chitosan/gelatin/β-TCP scaffolds for improved bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Serra, I.R.; Fradique, R.; Vallejo, M.C.S.; Correia, T.R.; Miguel, S.P.; Correia, I.J., E-mail:


    Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/β-TCP and chitosan/gelatin/β-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure. - Highlights: • Production of 3D scaffolds composed by chitosan/gelatin/β-TCP by freeze-drying for bone regeneration • Physicochemical characterization of the bone substitutes by SEM, FTIR, XRD and EDS • Evaluation of the cytotoxic profile and antibacterial activity of the 3D structures through in vitro assays.

  14. Bioactive polymeric–ceramic hybrid 3D scaffold for application in bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Torres, A.L.; Gaspar, V.M.; Serra, I.R.; Diogo, G.S.; Fradique, R. [CICS-UBI — Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã (Portugal); Silva, A.P. [CAST-UBI — Centre for Aerospace Science and Technologies, University of Beira Interior, Calçada Fonte do Lameiro, 6201-001 Covilhã (Portugal); Correia, I.J., E-mail: [CICS-UBI — Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã (Portugal)


    The regeneration of large bone defects remains a challenging scenario from a therapeutic point of view. In fact, the currently available bone substitutes are often limited by poor tissue integration and severe host inflammatory responses, which eventually lead to surgical removal. In an attempt to address these issues, herein we evaluated the importance of alginate incorporation in the production of improved and tunable β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) three-dimensional (3D) porous scaffolds to be used as temporary templates for bone regeneration. Different bioceramic combinations were tested in order to investigate optimal scaffold architectures. Additionally, 3D β-TCP/HA vacuum-coated with alginate, presented improved compressive strength, fracture toughness and Young's modulus, to values similar to those of native bone. The hybrid 3D polymeric–bioceramic scaffolds also supported osteoblast adhesion, maturation and proliferation, as demonstrated by fluorescence microscopy. To the best of our knowledge this is the first time that a 3D scaffold produced with this combination of biomaterials is described. Altogether, our results emphasize that this hybrid scaffold presents promising characteristics for its future application in bone regeneration. - Graphical abstract: B-TCP:HA–alginate hybrid 3D porous scaffolds for application in bone regeneration. - Highlights: • The produced hybrid 3D scaffolds are prone to be applied in bone tissue engineering. • Alginate coated 3D scaffolds present high mechanical and biological properties. • In vitro assays for evaluation of human osteoblast cell attachment in the presence of the scaffolds • The hybrid 3D scaffolds present suitable mechanical and biological properties for use in bone regenerative medicine.

  15. Polydopamine-Templated Hydroxyapatite Reinforced Polycaprolactone Composite Nanofibers with Enhanced Cytocompatibility and Osteogenesis for Bone Tissue Engineering. (United States)

    Gao, Xiang; Song, Jinlin; Ji, Ping; Zhang, Xiaohong; Li, Xiaoman; Xu, Xiao; Wang, Mengke; Zhang, Siqi; Deng, Yi; Deng, Feng; Wei, Shicheng


    Nanohydroxyapatite (HA) synthesized by biomimetic strategy is a promising nanomaterial as bone substitute due to its physicochemical features similar to those of natural nanocrystal in bone tissue. Inspired by mussel adhesive chemistry, a novel nano-HA was synthesized in our work by employing polydopamine (pDA) as template under weak alkaline condition. Subsequently, the as-prepared pDA-templated HA (tHA) was introduced into polycaprolactone (PCL) matrix via coelectrospinning, and a bioactive tHA/PCL composite nanofiber scaffold was developed targeted at bone regeneration application. Our research showed that tHA reinforced PCL composite nanofibers exhibited favorable cytocompatibility at given concentration of tHA (0-10 w.t%). Compared to pure PCL and traditional nano-HA enriched PCL (HA/PCL) composite nanofibers, enhanced cell adhesion, spreading and proliferation of human mesenchymal stem cells (hMSCs) were observed on tHA/PCL composite nanofibers on account of the contribution of pDA present in tHA. More importantly, tHA nanoparticles exposed on the surface of composite nanofibers could further promote osteogenesis of hMSCs in vitro even in the absence of osteogenesis soluble inducing factors when compared to traditional HA/PCL scaffolds, which was supported by in vivo test as well according to the histological analysis. Overall, our study demonstrated that the developed tHA/PCL composite nanofibers with enhanced cytocompatibility and osteogenic capacity hold great potential as scaffolds for bone tissue engineering.

  16. Regeneration-associated macrophages:a novel approach to boost intrinsic regenerative capacity for axon regeneration

    Institute of Scientific and Technical Information of China (English)

    Min Jung Kwon; Hyuk Jun Yoon; Byung Gon Kim


    Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord injury. Both intrinsic and extrinsic factors are responsible for the regeneration fail-ure. Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failurein vivo still remains elusive. Recent exper-imental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neu-rons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of en-hanced regeneration capacity. Neuron-derived chemokine (C-C motif) ligand 2 (CCL2) seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs). Ma-nipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries.

  17. Mechanisms of Increased Particle and VOC Emissions during DPF Active Regeneration and Practical Emissions Considering Regeneration. (United States)

    Yamada, Hiroyuki; Inomata, Satoshi; Tanimoto, Hiroshi


    Mechanisms involved in increased particle and volatile organic compound (VOC) emissions during active and parked active regenerations of a diesel particulate filter (DPF) were investigated using heavy-duty trucks equipped with both a urea selective catalytic reduction system and a DPF (SCR + DPF) and a DPF-only. Particle emissions increased in the later part of the regeneration period but the mechanisms were different above and below 23 nm. Particles above 23 nm were emitted due to the lower filtering efficiency of the DPF because of the decreasing amount of soot trapped during regeneration. Small particles below 23 nm were thought to be mainly sulfuric acid particles produced from SO2 trapped by the catalyst, being released and oxidized during regeneration. Contrary to the particle emissions, VOCs increased in the earlier part of the regeneration period. The mean molecular weights of the VOCs increased gradually as the regeneration proceeded. To evaluate "practical emissions" in which increased emissions during the regeneration were considered, a Regeneration Correction Factor (RCF), which is the average emission during one cycle of regeneration/emission in normal operation, was adopted. The RCFs of PM and VOCs were 1.1-1.5, and those of PNs were as high as 3-140, although they were estimated from a limited number of observations.

  18. Hyperbaric Oxygen Promotes Proximal Bone Regeneration and Organized Collagen Composition during Digit Regeneration. (United States)

    Sammarco, Mimi C; Simkin, Jennifer; Cammack, Alexander J; Fassler, Danielle; Gossmann, Alexej; Marrero, Luis; Lacey, Michelle; Van Meter, Keith; Muneoka, Ken


    Oxygen is critical for optimal bone regeneration. While axolotls and salamanders have retained the ability to regenerate whole limbs, mammalian regeneration is restricted to the distal tip of the digit (P3) in mice, primates, and humans. Our previous study revealed the oxygen microenvironment during regeneration is dynamic and temporally influential in building and degrading bone. Given that regeneration is dependent on a dynamic and changing oxygen environment, a better understanding of the effects of oxygen during wounding, scarring, and regeneration, and better ways to artificially generate both hypoxic and oxygen replete microenvironments are essential to promote regeneration beyond wounding or scarring. To explore the influence of increased oxygen on digit regeneration in vivo daily treatments of hyperbaric oxygen were administered to mice during all phases of the entire regenerative process. Micro-Computed Tomography (μCT) and histological analysis showed that the daily application of hyperbaric oxygen elicited the same enhanced bone degradation response as two individual pulses of oxygen applied during the blastema phase. We expand past these findings to show histologically that the continuous application of hyperbaric oxygen during digit regeneration results in delayed blastema formation at a much more proximal location after amputation, and the deposition of better organized collagen fibers during bone formation. The application of sustained hyperbaric oxygen also delays wound closure and enhances bone degradation after digit amputation. Thus, hyperbaric oxygen shows the potential for positive influential control on the various phases of an epimorphic regenerative response.

  19. Hyperbaric Oxygen Promotes Proximal Bone Regeneration and Organized Collagen Composition during Digit Regeneration.

    Directory of Open Access Journals (Sweden)

    Mimi C Sammarco

    Full Text Available Oxygen is critical for optimal bone regeneration. While axolotls and salamanders have retained the ability to regenerate whole limbs, mammalian regeneration is restricted to the distal tip of the digit (P3 in mice, primates, and humans. Our previous study revealed the oxygen microenvironment during regeneration is dynamic and temporally influential in building and degrading bone. Given that regeneration is dependent on a dynamic and changing oxygen environment, a better understanding of the effects of oxygen during wounding, scarring, and regeneration, and better ways to artificially generate both hypoxic and oxygen replete microenvironments are essential to promote regeneration beyond wounding or scarring. To explore the influence of increased oxygen on digit regeneration in vivo daily treatments of hyperbaric oxygen were administered to mice during all phases of the entire regenerative process. Micro-Computed Tomography (μCT and histological analysis showed that the daily application of hyperbaric oxygen elicited the same enhanced bone degradation response as two individual pulses of oxygen applied during the blastema phase. We expand past these findings to show histologically that the continuous application of hyperbaric oxygen during digit regeneration results in delayed blastema formation at a much more proximal location after amputation, and the deposition of better organized collagen fibers during bone formation. The application of sustained hyperbaric oxygen also delays wound closure and enhances bone degradation after digit amputation. Thus, hyperbaric oxygen shows the potential for positive influential control on the various phases of an epimorphic regenerative response.

  20. Regeneration-associated macrophages: a novel approach to boost intrinsic regenerative capacity for axon regeneration. (United States)

    Kwon, Min Jung; Yoon, Hyuk Jun; Kim, Byung Gon


    Axons in central nervous system (CNS) do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord injury. Both intrinsic and extrinsic factors are responsible for the regeneration failure. Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in vivo still remains elusive. Recent experimental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neurons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of enhanced regeneration capacity. Neuron-derived chemokine (C-C motif) ligand 2 (CCL2) seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs). Manipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries.

  1. Regeneration-associated macrophages: a novel approach to boost intrinsic regenerative capacity for axon regeneration

    Directory of Open Access Journals (Sweden)

    Min Jung Kwon


    Full Text Available Axons in central nervous system (CNS do not regenerate spontaneously after injuries such as stroke and traumatic spinal cord injury. Both intrinsic and extrinsic factors are responsible for the regeneration failure. Although intensive research efforts have been invested on extrinsic regeneration inhibitors, the extent to which glial inhibitors contribute to the regeneration failure in vivo still remains elusive. Recent experimental evidence has rekindled interests in intrinsic factors for the regulation of regeneration capacity in adult mammals. In this review, we propose that activating macrophages with pro-regenerative molecular signatures could be a novel approach for boosting intrinsic regenerative capacity of CNS neurons. Using a conditioning injury model in which regeneration of central branches of dorsal root ganglia sensory neurons is enhanced by a preceding injury to the peripheral branches, we have demonstrated that perineuronal macrophages surrounding dorsal root ganglia neurons are critically involved in the maintenance of enhanced regeneration capacity. Neuron-derived chemokine (C-C motif ligand 2 (CCL2 seems to mediate neuron-macrophage interactions conveying injury signals to perineuronal macrophages taking on a soley pro-regenerative phenotype, which we designate as regeneration-associated macrophages (RAMs. Manipulation of the CCL2 signaling could boost regeneration potential mimicking the conditioning injury, suggesting that the chemokine-mediated RAM activation could be utilized as a regenerative therapeutic strategy for CNS injuries.

  2. Adult stem cells underlying lung regeneration. (United States)

    Xian, Wa; McKeon, Frank


    Despite the massive toll in human suffering imparted by degenerative lung disease, including COPD, idiopathic pulmonary fibrosis and ARDS, the scientific community has been surprisingly agnostic regarding the potential of lung tissue, and in particular the alveoli, to regenerate. However, there is circumstantial evidence in humans and direct evidence in mice that ARDS triggers robust regeneration of lung tissue rather than irreversible fibrosis. The stem cells responsible for this remarkable regenerative process has garnered tremendous attention, most recently yielding a defined set of cloned human airway stem cells marked by p63 expression but with distinct commitment to differentiated cell types typical of the upper or lower airways, the latter of which include alveoli-like structures in vitro and in vivo. These recent advances in lung regeneration and distal airway stem cells and the potential of associated soluble factors in regeneration must be harnessed for therapeutic options in chronic lung disease.

  3. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Pryds, Nini


    Active magnetic regenerative (AMR) systems are being investigated because they represent a potentially attractive alternative to vapor compression technology. The performance of these systems is dependent on the heat transfer and pressure drop performance of the regenerator geometry. Therefore...

  4. Chronological protein synthesis in regenerating rat liver. (United States)

    He, Jinjun; Hao, Shuai; Zhang, Hao; Guo, Fuzheng; Huang, Lingyun; Xiao, Xueyuan; He, Dacheng


    Liver regeneration has been studied for decades; however, its regulation remains unclear. In this study, we report a dynamic tracing of protein synthesis in rat regenerating liver with a new proteomic technique, (35) S in vivo labeling analysis for dynamic proteomics (SiLAD). Conventional proteomic techniques typically measure protein alteration in accumulated amounts. The SiLAD technique specifically detects protein synthesis velocity instead of accumulated amounts of protein through (35) S pulse labeling of newly synthesized proteins, providing a direct way for analyzing protein synthesis variations. Consequently, protein synthesis within short as 30 min was visualized and protein regulations in the first 8 h of regenerating liver were dynamically traced. Further, the 3.5-5 h post partial hepatectomy (PHx) was shown to be an important regulatory turning point by acute regulation of many proteins in the initiation of liver regeneration.

  5. Advanced Engineering Strategies for Periodontal Complex Regeneration

    Directory of Open Access Journals (Sweden)

    Chan Ho Park


    Full Text Available The regeneration and integration of multiple tissue types is critical for efforts to restore the function of musculoskeletal complex. In particular, the neogenesis of periodontal constructs for systematic tooth-supporting functions is a current challenge due to micron-scaled tissue compartmentalization, oblique/perpendicular orientations of fibrous connective tissues to the tooth root surface and the orchestration of multiple regenerated tissues. Although there have been various biological and biochemical achievements, periodontal tissue regeneration remains limited and unpredictable. The purpose of this paper is to discuss current advanced engineering approaches for periodontal complex formations; computer-designed, customized scaffolding architectures; cell sheet technology-based multi-phasic approaches; and patient-specific constructs using bioresorbable polymeric material and 3-D printing technology for clinical application. The review covers various advanced technologies for periodontal complex regeneration and state-of-the-art therapeutic avenues in periodontal tissue engineering.

  6. Molecular mechanism of bone formation and regeneration

    Institute of Scientific and Technical Information of China (English)

    Akira Yamaguchi


    @@ Bone formation and regeneration are mediated by the coordinate action of various factors. Among these, bone morphogenetic protein (BMP) and runt-related gene 2 (Runx2) play crucial roles in bone formation.

  7. Skeletal muscle dedifferentiation during salamander limb regeneration. (United States)

    Wang, Heng; Simon, András


    Salamanders can regenerate entire limbs throughout their life. A critical step during limb regeneration is formation of a blastema, which gives rise to the new extremity. Salamander limb regeneration has historically been tightly linked to the term dedifferentiation, however, with refined research tools it is important to revisit the definition of dedifferentiation in the context. To what extent do differentiated cells revert their differentiated phenotypes? To what extent do progeny from differentiated cells cross lineage boundaries during regeneration? How do cell cycle plasticity and lineage plasticity relate to each other? What is the relationship between dedifferentiation of specialized cells and activation of tissue resident stem cells in terms of their contribution to the new limb? Here we highlight these problems through the case of skeletal muscle.

  8. De Novo Kidney Regeneration with Stem Cells

    Directory of Open Access Journals (Sweden)

    Shinya Yokote


    Full Text Available Recent studies have reported on techniques to mobilize and activate endogenous stem-cells in injured kidneys or to introduce exogenous stem cells for tissue repair. Despite many recent advantages in renal regenerative therapy, chronic kidney disease (CKD remains a major cause of morbidity and mortality and the number of CKD patients has been increasing. When the sophisticated structure of the kidneys is totally disrupted by end stage renal disease (ESRD, traditional stem cell-based therapy is unable to completely regenerate the damaged tissue. This suggests that whole organ regeneration may be a promising therapeutic approach to alleviate patients with uncured CKD. We summarize here the potential of stem-cell-based therapy for injured tissue repair and de novo whole kidney regeneration. In addition, we describe the hurdles that must be overcome and possible applications of this approach in kidney regeneration.

  9. Modulation of scar tissue formation using different dermal regeneration templates in the treatment of experimental full-thickness wounds.

    NARCIS (Netherlands)

    Druecke, D.; Lamme, E.N.; Hermann, S.; Pieper, J.S.; May, P.S.; Steinau, H.U.; Steinstraesser, L.


    The recovery of skin function is the goal of each burn surgeon. Split-skin graft treatment of full-thickness skin defects leads to scar formation, which is often vulnerable and instable. Therefore, the aim of this study was to analyze wound healing and scar tissue formation in acute full-thickness w

  10. Molecular template-directed synthesis of microporous polymer networks for highly selective CO2 capture. (United States)

    Shi, Yao-Qi; Zhu, Jing; Liu, Xiao-Qin; Geng, Jian-Cheng; Sun, Lin-Bing


    Porous polymer networks have great potential in various applications including carbon capture. However, complex monomers and/or expensive catalysts are commonly used for their synthesis, which makes the process complicated, costly, and hard to scale up. Herein, we develop a molecular template strategy to fabricate new porous polymer networks by a simple nucleophilic substitution reaction of two low-cost monomers (i.e., chloromethylbenzene and ethylene diamine). The polymerization reactions can take place under mild conditions in the absence of any catalysts. The resultant materials are interconnected with secondary amines and show well-defined micropores due to the structure-directing role of solvent molecules. These properties make our materials highly efficient for selective CO2 capture, and unusually high CO2/N2 and CO2/CH4 selectivities are obtained. Furthermore, the adsorbents can be completely regenerated under mild conditions. Our materials may provide promising candidates for selective capture of CO2 from mixtures such as flue gas and natural gas.

  11. DNA-templated nanowires as sacrificial materials for creating nanocapillaries (United States)

    Stewart, Jacob T.; Becerril, Hector A.; Yang, Weichun; Larsen, Megan G.; Woolley, Adam T.


    DNA has shown great promise as a template for the controlled localization of various materials and the construction of wires with nanometer-dimension cross sections. We have recently developed a strategy for fabrication of nanocapillaries, using DNA-templated nanowires as a sacrificial material. We first form metal nanowires through the selective electrochemical deposition of nickel atop a surface-aligned DNA molecule. We then deposit a thin layer of silicon dioxide on top of the DNA nanostructures. Next, we photolithographically pattern openings over the ends of the wires and etch through the silicon dioxide layer to expose the metal nanowires. Finally, we etch out the DNA-templated nickel nanowires. This process results in the formation of nanocapillaries having the same dimensions as the originally formed DNA-templated nanowires. We have characterized these DNA-templated nanocapillaries using atomic force microscopy, optical microscopy and scanning electron microscopy. These constructs have potential for application in nanofluidics, power generation, sample preconcentration, and chemical sensing.

  12. Template identification technology of nuclear warheads and components

    Institute of Scientific and Technical Information of China (English)

    Liu Su-Ping; Gong Jian; Hao Fan-Hua; Hu Guang-Chun


    Template identification technology (TIT) is designed for the scenarios where a batch of disarmed nuclear weapons or components would be dismantled to observe a nuclear disarmament treaty.The core function played by the TIT is to make a judgment on whether the verified item belongs to a certain kind of nuclear weapons or component (NW/NC) or to which kind the verified item belongs.This paper analyses the functions played by the TIT in the process of NW/NC dismantlement,and proposes that two phases would be followed when applying the TIT:firstly to establish NW/NC templates with a sample of size n drawn from a certain kind of disarmament NW;secondly to authenticate NW/NC by means of the TIT.This paper also expatiates some terms related to the concept of the TIT and investigates on the development status of NW/NC TIT based on radiation signatures.The study concludes that the design of template structure is crucial to the establishment of an effective TIT and that starting from different research angles and aiming at the same goal of classification different template structures and corresponding template identification methods can be built up to meet specific identification requirements.

  13. Missing Concepts in De Novo Pulp Regeneration


    Huang, G.T.-J.; Garcia-Godoy, F.


    Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been d...


    Directory of Open Access Journals (Sweden)

    Łukasz KONIECZNY


    Full Text Available The article presents the methodology of Common Rail injector diagnostic, regeneration and regulation with use of professional test stands. The EPS 815 machine can be used to test and repair all BOSCH injectors fully satisfying the producer requirements and standards. The article describes an example injector diagnosis with use of such test stand and additionally presents appropriate injector regeneration and encoding techniques

  15. Continuous microwave regeneration apparatus for absorption media (United States)

    Smith, Douglas D.


    A method and apparatus for continuously drying and regenerating ceramic beads for use in process gas moisture drying operations such as glove boxes. A microwave energy source is coupled to a process chamber to internally heat the ceramic beads and vaporize moisture contained therein. In a preferred embodiment, the moisture laden ceramic beads are conveyed toward the microwave source by a screw mechanism. The regenerated beads flow down outside of the screw mechanism and are available to absorb additional moisture.

  16. Erythropoietin stimulates hepatocyte regeneration after liver resection


    Schön, Michael R.; Hogrebe, Esther; Hengstler, Jan Georg; Donaubauer, Bernd; Faber, Sonya C.; Bauer, Alexander; Pietsch, Uta-Carolin; Jelkmann, Wolfgang; Thiery, Joachim; Hauss, Johann Peter; Tannapfel, Andrea


    The increased relevance of liver surgery and transplantation as a therapeutic modality over the last two decades mandates the development of novel strategies to improve liver regeneration. Here we studied whether erythropoietin (EPO) improves liver regeneration after hepatectomy in pigs. Eighteen female pigs underwent laparoscopic left lateral liver resection and were allocated randomly into three groups. No EPO was administered to the control group (group 1, n=6). Group 2 (...

  17. On-line regeneration of hydrodesulfurization catalyst (United States)

    Preston, Jr., John L.


    A hydrotreating catalyst is regenerated as it concurrently hydrotreats a hydrocarbon fuel by introducing a low concentration of oxygen into the catalyst bed either continuously or periodically. At low oxygen concentrations the carbon deposits on the catalyst are burned off without harming the catalyst and without significantly affecting the hydrotreating process. In a preferred embodiment the hydrotreating process is hydrodesulfurization, and regenerating is done periodically with oxygen concentrations between 0.1 and 0.5 volume percent.

  18. Advanced tissue engineering in periodontal Regeneration


    Seyed Ali Banihashemrad


    The old wishes of people were to regenerate lost tissues of periodontium that this fact is achieved by gen and cell therapy .Periodontal disease is a chronic inflammation around the tooth by microbes that causes destruction of supporting structure of tissue of tooth such as alveolar bone, cementum and periodontal ligament. For treatment of periodontal diseases we can use the biomaterials which help to regenerate the periodontal tissues like; autogenous bone grafts, allograft, guided tissue re...

  19. Ear wound regeneration in the African spiny mouse Acomys cahirinus


    Matias Santos, Dino; Rita, Ana Martins; Casanellas, Ignasi; Brito Ova, Adélia; Araújo, Inês Maria; Power, Deborah; Tiscornia, Gustavo


    Abstract While regeneration occurs in a number of taxonomic groups across the Metazoa, there are very few reports of regeneration in mammals, which generally respond to wounding with fibrotic scarring rather than regeneration. A recent report described skin shedding, skin regeneration and extensive ear punch closure in two rodent species, Acomys kempi and Acomys percivali. We examined these striking results by testing the capacity for regeneration of a third species, Acomys cahirinus, and fou...

  20. Guided tissue regeneration in periapical surgery. (United States)

    Lin, Louis; Chen, Melody Y-H; Ricucci, Domenico; Rosenberg, Paul A


    Tissue regeneration by using membrane barriers and bone grafting materials in periapical surgery is an example of tissue engineering technology. Membrane barriers and/or bone grafts are often used to enhance periapical new bone formation. However, the periapical tissues also consist of the periodontal ligament (PDL) and cementum. For regeneration of the periapical tissues after periapical surgery, one of the important requirements is recruitment and differentiation of progenitor/stem cells into committed pre-osteoblasts, pre-PDL cells, and pre-cementoblasts. Homing of progenitor/stem cells into the wounded periapical tissues is regulated by factors such as stromal cell-derived factor 1, growth factors/cytokines, and by microenvironmental cues such as adhesion molecules and extracellular matrix and associated noncollagenous molecules. Tissue regeneration after injury appears to recapitulate the pathway of normal embryonic tissue development. Multiple tissue regeneration involves a complex interaction between different cells, extracellular matrix, growth/differentiation factors, and microenvironmental cues. Little is known concerning the biologic mechanisms that regulate temporal and spatial relationship between alveolar bone, PDL, and cementum regeneration during periapical wound healing. Simply applying a membrane barrier and/or bone graft during periapical surgery might not result in complete regeneration of the periapical tissues. It has not been clearly demonstrated that these biomaterials are capable of recruiting progenitor/stem cells and inducing these undifferentiated mesenchymal cells to differentiate into PDL cells and cementoblasts after periapical surgery.

  1. The art of fin regeneration in zebrafish. (United States)

    Pfefferli, Catherine; Jaźwińska, Anna


    The zebrafish fin provides a valuable model to study the epimorphic type of regeneration, whereby the amputated part of the appendage is nearly perfectly replaced. To accomplish fin regeneration, two reciprocally interacting domains need to be established at the injury site, namely a wound epithelium and a blastema. The wound epithelium provides a supporting niche for the blastema, which contains mesenchyme-derived progenitor cells for the regenerate. The fate of blastemal daughter cells depends on their relative position with respect to the fin margin. The apical compartment of the outgrowth maintains its undifferentiated character, whereas the proximal descendants of the blastema progressively switch from the proliferation program to the morphogenesis program. A delicate balance between self-renewal and differentiation has to be continuously adjusted during the course of regeneration. This review summarizes the current knowledge about the cellular and molecular mechanisms of blastema formation, and discusses several studies related to the regulation of growth and morphogenesis during fin regeneration. A wide range of canonical signaling pathways has been implicated during the establishment and maintenance of the blastema. Epigenetic mechanisms play a crucial role in the regulation of cellular plasticity during the transition between differentiation states. Ion fluxes, gap-junctional communication and protein phosphatase activity have been shown to coordinate proliferation and tissue patterning in the caudal fin. The identification of the downstream targets of the fin regeneration signals and the discovery of mechanisms integrating the variety of input pathways represent exciting future aims in this fascinating field of research.

  2. Limb Regeneration in Axolotl: Is It Superhealing?

    Directory of Open Access Journals (Sweden)

    Stéphane Roy


    Full Text Available The ability of axolotls to regenerate their limbs is almost legendary. In fact, urodeles such as the axolotl are the only vertebrates that can regenerate multiple structures like their limbs, jaws, tail, spinal cord, and skin (the list goes on throughout their lives. It is therefore surprising to realize, although we have known of their regenerative potential for over 200 years, how little we understand the mechanisms behind this achievement of adult tissue morphogenesis. Many observations can be drawn between regeneration and other disciplines such as development and wound healing. In this review, we present new developments in functional analysis that will help to address the role of specific genes during the process of regeneration. We also present an analysis of the resemblance between wound healing and regeneration, and discuss whether axolotls are superhealers. A better understanding of these animals' regenerative capacity could lead to major benefits by providing regenerative medicine with directions on how to develop therapeutic approaches leading to regeneration in humans.

  3. Silymarin Accelerates Liver Regeneration after Partial Hepatectomy

    Directory of Open Access Journals (Sweden)

    Jia-Ping Wu


    Full Text Available Partial hepatectomy (PHx is a liver regeneration physiological response induced to maintain homeostasis. Liver regeneration evolved presumably to protect wild animals from catastrophic liver loss caused by toxins or tissue injury. Silymarin (Sm ability to stimulate liver regeneration has been an object of curiosity for many years. Silymarin has been investigated for use as an antioxidant and anticarcinogen. However, its use as a supportive treatment for liver damage is elusive. In this study, we fed silymarin (Sm, 25 mg/kg to male Sprague-Dawley rats for 7 weeks. Surgical 2/3 PHx was then conducted on the rats at 6 hrs, 24 hrs, and 72 hrs. Western blot and RT-PCR were conducted to detect the cell cycle activities and silymarin effects on hepatic regeneration. The results showed that silymarin enhanced liver regeneration by accelerating the cell cycle in PHx liver. Silymarin led to increased G1 phase (cyclin D1/pRb, S phase (cyclin E/E2F, G2 phase (cyclin B, and M phase (cyclin A protein and mRNA at 6 hrs, 24 hrs, and 72 hrs PHx. HGF, TGFα, and TGFβ1 growth factor expressions were also enhanced. We suggest that silymarin plays a crucial role in accelerated liver regeneration after PHx.

  4. The Architectural Practice of Regeneration

    Directory of Open Access Journals (Sweden)

    Tom Van Malderen


    Full Text Available In form and in content, cities are the epitome of diversity. This state is the result of the accumulation of layers of history, of construction, of demolition and reconstruction cycles. These tensions are the catalyst for the emergence of new urban forms and participate in the construction of heritage. As such they should be encouraged. As important as the existing fabric of the city is, its evolution to accommodate the ever-changing needs and fashions of its inhabitants is paramount. For regeneration to be successful it must inscribe itself in this process and it must be driven by an understanding of the environment where it occurs. This paper explores, through the lens of an architectural practice, some design processes and architectural proposals that have been generated by working on the Valletta harbours. It also discusses the necessary dynamics required to accommodate stakeholder engagement and planning policy while ensuring design quality and the perpetuation of the creative process inherent to the city. Finally, the paper introduces, as a possible future, the experiments and studies of the practice on the wider Valletta, putting into perspective the benefits of theoretical research combined with formal and aesthetic explorations of the harbour region.

  5. Tissue Regeneration: A Silk Road (United States)

    Jao, Dave; Mou, Xiaoyang; Hu, Xiao


    Silk proteins are natural biopolymers that have extensive structural possibilities for chemical and mechanical modifications to facilitate novel properties, functions, and applications in the biomedical field. The versatile processability of silk fibroins (SF) into different forms such as gels, films, foams, membranes, scaffolds, and nanofibers makes it appealing in a variety of applications that require mechanically superior, biocompatible, biodegradable, and functionalizable biomaterials. There is no doubt that nature is the world’s best biological engineer, with simple, exquisite but powerful designs that have inspired novel technologies. By understanding the surface interaction of silk materials with living cells, unique characteristics can be implemented through structural modifications, such as controllable wettability, high-strength adhesiveness, and reflectivity properties, suggesting its potential suitability for surgical, optical, and other biomedical applications. All of the interesting features of SF, such as tunable biodegradation, anti-bacterial properties, and mechanical properties combined with potential self-healing modifications, make it ideal for future tissue engineering applications. In this review, we first demonstrate the current understanding of the structures and mechanical properties of SF and the various functionalizations of SF matrices through chemical and physical manipulations. Then the diverse applications of SF architectures and scaffolds for different regenerative medicine will be discussed in detail, including their current applications in bone, eye, nerve, skin, tendon, ligament, and cartilage regeneration. PMID:27527229

  6. Tissue Regeneration: A Silk Road. (United States)

    Jao, Dave; Mou, Xiaoyang; Hu, Xiao


    Silk proteins are natural biopolymers that have extensive structural possibilities for chemical and mechanical modifications to facilitate novel properties, functions, and applications in the biomedical field. The versatile processability of silk fibroins (SF) into different forms such as gels, films, foams, membranes, scaffolds, and nanofibers makes it appealing in a variety of applications that require mechanically superior, biocompatible, biodegradable, and functionalizable biomaterials. There is no doubt that nature is the world's best biological engineer, with simple, exquisite but powerful designs that have inspired novel technologies. By understanding the surface interaction of silk materials with living cells, unique characteristics can be implemented through structural modifications, such as controllable wettability, high-strength adhesiveness, and reflectivity properties, suggesting its potential suitability for surgical, optical, and other biomedical applications. All of the interesting features of SF, such as tunable biodegradation, anti-bacterial properties, and mechanical properties combined with potential self-healing modifications, make it ideal for future tissue engineering applications. In this review, we first demonstrate the current understanding of the structures and mechanical properties of SF and the various functionalizations of SF matrices through chemical and physical manipulations. Then the diverse applications of SF architectures and scaffolds for different regenerative medicine will be discussed in detail, including their current applications in bone, eye, nerve, skin, tendon, ligament, and cartilage regeneration.

  7. Template free synthesis of natural carbohydrates functionalised fluorescent silver nanoclusters. (United States)

    Ebrahiminezhad, Alireza; Berenjian, Aydin; Ghasemi, Younes


    Template-assisted synthesis is one of the most recognised techniques for fabrication of silver nanoclusters (AgNCs). However, this process is time consuming, toxic and expensive. In this study, the authors report a completely novel approach for the green and facile synthesis of AgNCs using Matricaria chamomilla, without any additional template. Fluorescent and colloidally stable AgNCs with average particle size of 2.4 nm were successfully produced. They found that carbohydrates from Matricaria chamomilla act as an ideal template to generate fluorescent AgNCs. Moreover, oxygen-bearing functional groups were validated to be the active groups for anchoring and reducing of Ag(+) ions. The novel carbohydrate coating method makes the prepared nanoclusters completely hydrophilic and stable in aqueous matrices.

  8. Geometrical assembly of ultrastable protein templates for nanomaterials (United States)

    Glover, Dominic J.; Giger, Lars; Kim, Steve S.; Naik, Rajesh R.; Clark, Douglas S.


    The fabrication of nanoscale devices requires architectural templates on which to position functional molecules in complex arrangements. Protein scaffolds are particularly promising templates for nanomaterials due to inherent molecular recognition and self-assembly capabilities combined with genetically encoded functionalities. However, difficulties in engineering protein quaternary structure into stable and well-ordered shapes have hampered progress. Here we report the development of an ultrastable biomolecular construction kit for the assembly of filamentous proteins into geometrically defined templates of controllable size and symmetry. The strategy combines redesign of protein-protein interaction specificity with the creation of tunable connector proteins that govern the assembly and projection angles of the filaments. The functionality of these nanoarchitectures is illustrated by incorporation of nanoparticles at specific locations and orientations to create hybrid materials such as conductive nanowires. These new structural components facilitate the manufacturing of nanomaterials with diverse shapes and functional properties over a wide range of processing conditions.

  9. Template synthesis, characterization and transformations of iron nanowires while aging

    Energy Technology Data Exchange (ETDEWEB)

    Jagminas, Arunas [Institute of Chemistry, A. Gostauto 9, LT-01108 Vilnius (Lithuania)], E-mail:; Mazeika, Kestutis; Reklaitis, Jonas [Institute of Physics, Savanoriu 231, LT-02300 Vilnius (Lithuania); Kurtinaitiene, Marija [Institute of Chemistry, A. Gostauto 9, LT-01108 Vilnius (Lithuania); Baltrunas, Dalis [Institute of Physics, Savanoriu 231, LT-02300 Vilnius (Lithuania)


    Densely packed arrays of various materials demonstrating enhanced magnetic properties remain of great interest nowadays. In this study, transmission electron microscopy (TEM), Moessbauer spectroscopy (MS) and powder X-ray diffraction (XRD) were used to characterize the morphology, composition and phase of iron nanowires (nws) deposited from the developed solution within alumina template pores of the average diameter of ca.15 nm by the alternating current (ac) electrolysis protocol. The same investigations were performed after Fe nws storage in the air for several months. Characterization of the as-grown product shows the formation of the crystalline {alpha}-Fe nws array with a preferred [1 1 0] nw growth direction. The aging of samples leads to the corrosion of Fe nws mainly from the template top side while aging of Fe nws liberated from the template and kept for several months under ambient conditions results in the corrosion of nws along their full length producing catkin-twig shapes.

  10. Nanoline templates for single atom wires on Si(001)

    Energy Technology Data Exchange (ETDEWEB)

    Koester, Sigrun A.; Owen, James H.G.; Bianco, Francois; Mazur, Daniel; Renner, Chrisoph [Universite de Geneve, Section Physique/DPMC, Geneve (Switzerland); Rodriguez-Prieto, Alvaro; Bowler, David R. [London Centre for Nanotechnology (LCN), University College London (United Kingdom)


    Low dimensional structures are of wide scientific and technological interest. The physics of single atom metallic wires is already described in detail by theory, but a more systematic experimental verification is still desirable. The experimental problems are mainly caused by the difficulties of growing electronically isolated wires which is necessary to test the expected properties from existing theories. Here we introduce templates on a Si(001) surface which enable the growth of self-assembled single atom wires on top of them. The main template consists of a Si reconstruction called the Haiku structure which develops underneath self-assembled Bi nanowires. By hydrogenation the Si surface can be passivated and additionally the Bi dimers are stripped off while the underlying reconstruction of the Si surface remains intact. In addition the Bi nanowire by itself can be considered as a template.

  11. Implementation Support of Security Design Patterns Using Test Templates

    Directory of Open Access Journals (Sweden)

    Masatoshi Yoshizawa


    Full Text Available Security patterns are intended to support software developers as the patterns encapsulate security expert knowledge. However, these patterns may be inappropriately applied because most developers are not security experts, leading to threats and vulnerabilities. Here we propose a support method for security design patterns in the implementation phase of software development. Our method creates a test template from a security design pattern, consisting of an “aspect test template” to observe the internal processing and a “test case template”. Providing design information creates a test from the test template with a tool. Because our test template is reusable, it can easily perform a test to validate a security design pattern. In an experiment involving four students majoring in information sciences, we confirm that our method can realize an effective test, verify pattern applications, and support pattern implementation.

  12. Kinetic theory and thermodynamics of template-directed copolymerization (United States)

    Gaspard, Pierre


    Template-directed copolymerization is the fundamental process for the replication, transcription, and translation of genetic information. The copy of the template sequence is grown by the attachment of monomers with a molecular machine. The long-time kinetics of such processes is exactly solvable in terms of iterated function systems. This method determines the effects of sequence heterogeneity and replication errors on the growth of the copy and the statistical properties of its sequence. In particular, a transition can occur between linear and sublinear growth in time of the copy. In the linear regime, the local growth velocity along the template may have a fractal distribution. Furthermore, the growth can be driven around equilibrium by the entropic effect of replication errors in an adverse free-energy landscape.

  13. Fabrication of YBCO nanowires with anodic aluminum oxide (AAO) template

    Energy Technology Data Exchange (ETDEWEB)

    Dadras, Sedigheh, E-mail:; Aawani, Elaheh


    We have fabricated YBCO nanowires by using anodic aluminum oxide (AAO) template and sol–gel method, to investigate the fundamental properties of the one-dimensional nanostructure YBCO high-temperature superconductor and enhance its applications. The field-emission scanning electron microscopy and X-ray diffraction pattern results have shown forming of Y-123 nanowires in the template. As an outcome, the YBCO nanowires, prepared by dipping AAO template into YBCO sol method, have average diameter of about 38 nm and length of 1 μm; this is an optimum nanowire sample with larger diameter and length. The resistance–temperature measurement indicates that the onset critical temperature of these samples occurs at 91 K, and the resistance of the optimum sample at onset transition is 10 times lower than the other sample.

  14. Template-Directed Biopolymerization: Tape-Copying Turing Machines (United States)

    Sharma, Ajeet K.; Chowdhury, Debashish


    DNA, RNA and proteins are among the most important macromolecules in a living cell. These molecules are polymerized by molecular machines. These natural nano-machines polymerize such macromolecules, adding one monomer at a time, using another linear polymer as the corresponding template. The machine utilizes input chemical energy to move along the template which also serves as a track for the movements of the machine. In the Alan Turing year 2012, it is worth pointing out that these machines are "tape-copying Turing machines". We review the operational mechanisms of the polymerizer machines and their collective behavior from the perspective of statistical physics, emphasizing their common features in spite of the crucial differences in their biological functions. We also draw the attention of the physics community to another class of modular machines that carry out a different type of template-directed polymerization. We hope this review will inspire new kinetic models for these modular machines.

  15. A non-parametric 2D deformable template classifier

    DEFF Research Database (Denmark)

    Schultz, Nette; Nielsen, Allan Aasbjerg; Conradsen, Knut;


    We introduce an interactive segmentation method for a sea floor survey. The method is based on a deformable template classifier and is developed to segment data from an echo sounder post-processor called RoxAnn. RoxAnn collects two different measures for each observation point, and in this 2D...... feature space the ship-master will be able to interactively define a segmentation map, which is refined and optimized by the deformable template algorithms. The deformable templates are defined as two-dimensional vector-cycles. Local random transformations are applied to the vector-cycles, and stochastic...... relaxation in a Bayesian scheme is used. In the Bayesian likelihood a class density function and its estimate hereof is introduced, which is designed to separate the feature space. The method is verified on data collected in Øresund, Scandinavia. The data come from four geographically different areas. Two...

  16. Mesoporous silica and organosilica films templated by nanocrystalline chitin. (United States)

    Nguyen, Thanh-Dinh; Shopsowitz, Kevin E; MacLachlan, Mark J


    Liquid crystalline phases can be used to impart order into inorganic solids, creating materials that mimic natural architectures. Herein, mesoporous silica and organosilica films with layered structures and high surface areas have been templated by nanocrystalline chitin. Aqueous suspensions of spindle-shaped chitin nanocrystals were prepared by sequential deacetylation and hydrolysis of chitin fibrils isolated from king crab shells. The nanocrystalline chitin self-assembles into a nematic liquid-crystalline phase that has been used to template silica and organosilica composites. Removal of the chitin template by either calcination or sulfuric-acid-catalyzed hydrolysis gave mesoporous silica and ethylene-bridged organosilica films. The large, crack-free mesoporous films have layered structures with features that originate from the nematic organization of the nanocrystalline chitin.

  17. Electroless Fabrication of Cobalt Alloys Nanowires within Alumina Template

    Directory of Open Access Journals (Sweden)

    Nazila Dadvand


    Full Text Available A new method of nanowire fabrication based on electroless deposition process is described. The method is novel compared to the current electroless procedure used in making nanowires as it involves growing nanowires from the bottom up. The length of the nanowires was controlled at will simply by adjusting the deposition time. The nanowires were fabricated within the nanopores of an alumina template. It was accomplished by coating one side of the template by a thin layer of palladium in order to activate the electroless deposition within the nanopores from bottom up. However, prior to electroless deposition process, the template was pretreated with a suitable wetting agent in order to facilitate the penetration of the plating solution through the pores. As well, the electroless deposition process combined with oblique metal evaporation process within a prestructured silicon wafer was used in order to fabricate long nanowires along one side of the grooves within the wafer.

  18. Templates for Cross-Cultural and Culturally Specific Usability Testing

    DEFF Research Database (Denmark)

    Clemmensen, Torkil


    The cultural diversity of users of technology challenges our methods for usability testing. This article suggests templates for cross-culturally and culturally specific usability testing, based on studies of usability testing in companies in Mumbai, Beijing, and Copenhagen. Study 1 was a cross...... tests. The result was the construction of templates for usability testing. The culturally specific templates were in Mumbai “user-centered evaluation,” Copenhagen “client-centered evaluation,” and Beijing “evaluator-centered evaluation.” The findings are compared with related research......-cultural field study of think-aloud testing done by usability vendor companies in the three countries. The result was a grounded theory of cultural variations in the production of a usability problem list. Study 2 was a follow-up, ethnographic interview study of how the companies typically perform usability...

  19. A geometric transformation to protect minutiae-based fingerprint templates (United States)

    Sutcu, Yagiz; Sencar, Husrev T.; Memon, Nasir


    The increasing use of biometrics in different environments presents new challenges. Most importantly, biometric data are irreplaceable. Therefore, storing biometric templates, which is unique to individual user, entails significant security risks. In this paper, we propose a geometric transformation for securing the minutiae based fingerprint templates. The proposed scheme employs a robust one-way transformation that maps geometrical configuration of the minutiae points into a fixed-length code vector. This representation enables efficient alignment and reliable matching. Experiments are conducted by applying the proposed method on a synthetically generated minutiae point sets. Preliminary results show that the proposed scheme provides a simple and effective solution to the template security problem of the minutiae based fingerprint.

  20. Conducting Polymer Nanostructures: Template Synthesis and Applications in Energy Storage

    Directory of Open Access Journals (Sweden)

    Lijia Pan


    Full Text Available Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed.

  1. Conducting polymer nanostructures: template synthesis and applications in energy storage. (United States)

    Pan, Lijia; Qiu, Hao; Dou, Chunmeng; Li, Yun; Pu, Lin; Xu, Jianbin; Shi, Yi


    Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed.

  2. 3D-printed guiding templates for improved osteosarcoma resection (United States)

    Ma, Limin; Zhou, Ye; Zhu, Ye; Lin, Zefeng; Wang, Yingjun; Zhang, Yu; Xia, Hong; Mao, Chuanbin


    Osteosarcoma resection is challenging due to the variable location of tumors and their proximity with surrounding tissues. It also carries a high risk of postoperative complications. To overcome the challenge in precise osteosarcoma resection, computer-aided design (CAD) was used to design patient-specific guiding templates for osteosarcoma resection on the basis of the computer tomography (CT) scan and magnetic resonance imaging (MRI) of the osteosarcoma of human patients. Then 3D printing technique was used to fabricate the guiding templates. The guiding templates were used to guide the osteosarcoma surgery, leading to more precise resection of the tumorous bone and the implantation of the bone implants, less blood loss, shorter operation time and reduced radiation exposure during the operation. Follow-up studies show that the patients recovered well to reach a mean Musculoskeletal Tumor Society score of 27.125.

  3. Template engaged synthesis of hollow ceria-based composites (United States)

    Chen, Guozhu; Rosei, Federico; Ma, Dongling


    Hollow ceria-based composites, which consist of noble metal nanoparticles or metal oxides as a secondary component, are being studied extensively for potential applications in heterogeneous catalysis. This is due to their unique features, which exhibit the advantages of a hollow structure (e.g. high surface area and low weight), and also integrate the properties of ceria and noble metals/metal oxides. More importantly, the synergistic effect between constituents in hollow ceria-based composites has been demonstrated in various catalytic reactions. In this feature article, we summarize the state-of-the-art in the synthesis of hollow ceria-based composites, including traditional hard-templates and more recently, sacrificial-template engaged strategies, highlighting the key role of selected templates in the formation of hollow composites. In addition, the catalytic applications of hollow ceria-based composites are briefly surveyed. Finally, challenges and perspectives on future advances of hollow ceria-based composites are outlined.

  4. Automatic script identification from images using cluster-based templates

    Energy Technology Data Exchange (ETDEWEB)

    Hochberg, J.; Kerns, L.; Kelly, P.; Thomas, T.


    We have developed a technique for automatically identifying the script used to generate a document that is stored electronically in bit image form. Our approach differs from previous work in that the distinctions among scripts are discovered by an automatic learning procedure, without any handson analysis. We first develop a set of representative symbols (templates) for each script in our database (Cyrillic, Roman, etc.). We do this by identifying all textual symbols in a set of training documents, scaling each symbol to a fixed size, clustering similar symbols, pruning minor clusters, and finding each cluster`s centroid. To identify a new document`s script, we identify and scale a subset of symbols from the document and compare them to the templates for each script. We choose the script whose templates provide the best match. Our current system distinguishes among the Armenian, Burmese, Chinese, Cyrillic, Ethiopic, Greek, Hebrew, Japanese, Korean, Roman, and Thai scripts with over 90% accuracy.

  5. Hierarchical Template Matching for Robust Visual Tracking with Severe Occlusions

    Institute of Scientific and Technical Information of China (English)

    Lizuo Jin; Tirui Wu; Feng Liu; Gang Zeng


    To tackle the problem of severe occlusions in visual tracking, we propose a hierarchical template-matching method based on a layered appearance model. This model integrates holistic- and part-region matching in order to locate an object in a coarse-to-fine manner. Furthermore, in order to reduce ambiguity in object localization, only the discriminative parts of an object' s appearance template are chosen for similarity computing with respect to their cornerness measurements. The similarity between parts is computed in a layer-wise manner, and from this, occlusions can be evaluated. When the object is partly occluded, it can be located accurately by matching candidate regions with the appearance template. When it is completely occluded, its location can be predicted from its historical motion information using a Kalman filter. The proposed tracker is tested on several practical image sequences, and the experimental results show that it can consistently provide accurate object location for stable tracking, even for severe occlusions.

  6. Template-directed biopolymerization: tape-copying Turing machines

    CERN Document Server

    Sharma, Ajeet K; 10.1142/S1793048012300083


    DNA, RNA and proteins are among the most important macromolecules in a living cell. These molecules are polymerized by molecular machines. These natural nano-machines polymerize such macromolecules, adding one monomer at a time, using another linear polymer as the corresponding template. The machine utilizes input chemical energy to move along the template which also serves as a track for the movements of the machine. In the Alan Turing year 2012, it is worth pointing out that these machines are "tape-copying Turing machines". We review the operational mechanisms of the polymerizer machines and their collective behavior from the perspective of statistical physics, emphasizing their common features in spite of the crucial differences in their biological functions. We also draw attention of the physics community to another class of modular machines that carry out a different type of template-directed polymerization. We hope this review will inspire new kinetic models for these modular machines.

  7. Competitive SWIFT cluster templates enhance detection of aging changes (United States)

    Rebhahn, Jonathan A.; Roumanes, David R.; Qi, Yilin; Khan, Atif; Thakar, Juilee; Rosenberg, Alex; Lee, F. Eun‐Hyung; Quataert, Sally A.; Sharma, Gaurav


    Abstract Clustering‐based algorithms for automated analysis of flow cytometry datasets have achieved more efficient and objective analysis than manual processing. Clustering organizes flow cytometry data into subpopulations with substantially homogenous characteristics but does not directly address the important problem of identifying the salient differences in subpopulations between subjects and groups. Here, we address this problem by augmenting SWIFT—a mixture model based clustering algorithm reported previously. First, we show that SWIFT clustering using a “template” mixture model, in which all subpopulations are represented, identifies small differences in cell numbers per subpopulation between samples. Second, we demonstrate that resolution of inter‐sample differences is increased by “competition” wherein a joint model is formed by combining the mixture model templates obtained from different groups. In the joint model, clusters from individual groups compete for the assignment of cells, sharpening differences between samples, particularly differences representing subpopulation shifts that are masked under clustering with a single template model. The benefit of competition was demonstrated first with a semisynthetic dataset obtained by deliberately shifting a known subpopulation within an actual flow cytometry sample. Single templates correctly identified changes in the number of cells in the subpopulation, but only the competition method detected small changes in median fluorescence. In further validation studies, competition identified a larger number of significantly altered subpopulations between young and elderly subjects. This enrichment was specific, because competition between templates from consensus male and female samples did not improve the detection of age‐related differences. Several changes between the young and elderly identified by SWIFT template competition were consistent with known alterations in the elderly, and additional

  8. Inkjet print microchannels based on a liquid template. (United States)

    Guo, Yuzhen; Li, Lihong; Li, Fengyu; Zhou, Haihua; Song, Yanlin


    A simple method to fabricate microchannels is demonstrated based on an inkjet printing liquid template. The morphology of the liquid template can be well controlled by using ink with viscosity sensitive to temperature. The as-prepared Y-shape microchannel is used as a microfluidic reactor for an acylation fluorigenic reaction in a matrix of polydimethylsiloxane (PDMS). Arbitrary modification of the microchannels could be easily realized synchronously with the formation of the microchannels. By grafting polyethylene glycol (PEG) onto the internal surface, an anti-biosorption microchannel is obtained. The facile method will be significant for the fabrication of a microfluidic chip with functional modifications.

  9. Coordinated organogel templated fabrication of silver/polypyrrole composite nanowires

    Institute of Scientific and Technical Information of China (English)

    Bo Tian Li; Li Ming Tang; Kai Chen; Yu Xia; Xin Jin


    A new method to fabricate metal/conducting polymer composite nanowires is presented by taking silver/polypyrrole composite nanowires as an example.A silver (Ⅰ)-coordinated organogel as template was prepared firstly,and redox-polymerization of pyrrole took place on the gel fiber,giving product of silver/polypyrrole nanowires.The silver/polypyrrole nanowires were characterized by multiple techniques.This strategy could be carried out in one-step procedure at room temperature,and it proves the utility of coordinated organogels in template synthesis of polymer nanostructures.

  10. Modelling Template for the Development of the Process Flowsheet

    DEFF Research Database (Denmark)

    Fedorova, Marina; Gani, Rafiqul


    in connection to other modelling tools within the modelling framework are forming a user-friendly system, which will make the model development process easier and faster and provide the way for unified and consistent model documentation. The modeller can use the template for their specific problem or to extend...... parts in the modelling framework is highlighted through a development of a simple flowsheet model. Initially the model equations are obtained from the tool for model generation and then transferred to model analysis tool. Further, based on this model, a modelling template is created, which is used later...

  11. DNA-Templated Introduction of an Aldehyde Handle in Proteins

    DEFF Research Database (Denmark)

    Kodal, Anne Louise Bank; Rosen, Christian Bech; Mortensen, Michael Rosholm;


    -templated reductive amination we create DNA-protein conjugates with control over labeling stoichiometry without genetic engineering. A guiding DNA strand with a metal-binding functionality facilitates site-selectivity by directing coupling of a second reactive DNA strand to the vicinity of a protein metal......-binding site. Here, we demonstrate DNA-templated reductive amination for His6-tagged proteins and native metal-binding proteins, including IgG1 antibodies. We also use a cleavable linker between the DNA and the protein to remove the DNA and introduce a single aldehyde to proteins. This functions as a handle...

  12. Incidência de trombo intracardíaco e de tromboembolismo nos três primeiros meses após o implante de bioprótese valvar Incidence of intracardiac thrombus and thromboembolism in the first three months after bioprosthetic valve implantation

    Directory of Open Access Journals (Sweden)

    Auristela Isabel de Oliveira Ramos


    Full Text Available OBJETIVO: Avaliar a incidência de trombo intracardíaco e de tromboembolismo nos três primeiros meses após a troca valvar por bioprótese e identificar fatores de risco para a formação de trombo. MÉTODO:Incluídos 184 pacientes, entre 15 e 75 anos de idade, submetidos a implante de bioprótese e realizados ecocardiogramas transtorácico e transesofágico (ETE na fase hospitalar, média 8,4±3 dias, e três meses após, média 97,4±21,7 dias. RESULTADOS: Incidência de trombo foi significativamente mais elevada nos pacientes com prótese em posição mitral ou mitroaórtica (21,0% do que em posição aórtica (2,8%, pOBJECTIVE: To assess the incidence of intracardiac thrombus and thromboembolism in the first 3 months after bioprosthetic valve replacement and to identify the risk factors for thrombus formation. METHODS: The study comprised 184 patients, aged between 15 and 75 years, who underwent bioprosthetic valve implantation. Transthoracic and transesophageal (TEE echocardiographies were performed in the in-hospital phase (mean, 8.4±3 days and after 3 months (mean, 97.4±21.7 days. RESULTS: The incidence of thrombus was significantly greater in patients with a prosthesis in the mitral or mitroaortic position (21.0% than in those with a prosthesis in the aortic position (2.8%, P<0.001. The multiple logistic regression identified the prosthesis in the mitral or mitroaortic position as the only independent variable for thrombus formation. On the 3-month follow-up, TEE showed a thrombus in 35 (20.7% of the 169 patients on echocardiographic assessment, 31.7% in mitral patients and 3.1% in aortic patients, P<0.001. In the third month, the multiple logistic regression also identified the prosthesis in the mitral or mitroaortic position as the only independent variable for thrombus formation. During the 3-month follow-up, 3 (1.6% patients died and 8 (4.3% experienced embolic phenomena, all in the cerebral territory. CONCLUSION: The incidence

  13. A numerical analysis of a reciprocating Active Magnetic Regenerator with a parallel-plate regenerator geometry

    DEFF Research Database (Denmark)

    Petersen, Thomas Frank; Pryds, Nini; Smith, Anders;


    We have developed a two-dimensional model of a reciprocating Active Magnetic Regenerator(AMR) with a regenerator made of parallel plates arranged in a stack configuration. The time dependent,two-dimensional model solves the Navier-Stokes equations for the heat transfer fluid and the coupled heat...

  14. Regeneration in natural and logged tropical rain forest : modelling seed dispersal and regeneration

    NARCIS (Netherlands)

    Ulft, Lambertus Henricus van


    Regeneration and disturbance are thought to play key roles in the maintenance of the high tree species diversity in tropical rain forests. Nevertheless, the earliest stages in the regeneration of tropical rain forest trees, from seed production to established seedlings, have received little attenti

  15. Unified description of regeneration by coupled dynamical systems theory: intercalary/segmented regeneration in insect legs. (United States)

    Yoshida, Hiroshi; Kaneko, Kunihiko


    Regeneration phenomena are ubiquitous in nature and are studied in a variety of experiments. Positional information and feedback-loop hierarchy are theories that have been proposed to explain ordering rules in regeneration; however, some regeneration phenomena violate the rules derived from them. In particular, grafted junction stumps with the same value/hierarchy sometimes lead to one extra segmented portion, termed segmented regeneration. To present a unified description of all insect leg regeneration phenomena, we propose a theoretical mechanism for regeneration without postulating positional information, by using a model that consists of intracellular reaction dynamics of chemical concentrations, cell-to-cell interactions, and an increase in cell number. As a normal developmental process, successive differentiation from pluripotent cells appears, as described by transition from cells with intracellular chaotic dynamics to those with oscillatory or fixed-point dynamics. By assigning chaotic and nonchaotic cell types to corresponding positions instead of positional information, intercalary, segmented, and tarsus regeneration are explained coherently. With this assignment of pluripotency to chaotic dynamics, a unified description of regeneration is obtained with some predictive value for new experiments.

  16. A highly oriented hybrid microarray modified electrode fabricated by a template-free method for ultrasensitive electrochemical DNA recognition (United States)

    Shi, Lei; Chu, Zhenyu; Dong, Xueliang; Jin, Wanqin; Dempsey, Eithne


    Highly oriented growth of a hybrid microarray was realized by a facile template-free method on gold substrates for the first time. The proposed formation mechanism involves an interfacial structure-directing force arising from self-assembled monolayers (SAMs) between gold substrates and hybrid crystals. Different SAMs and variable surface coverage of the assembled molecules play a critical role in the interfacial directing forces and influence the morphologies of hybrid films. A highly oriented hybrid microarray was formed on the highly aligned and vertical SAMs of 1,4-benzenedithiol molecules with rigid backbones, which afforded an intense structure-directing power for the oriented growth of hybrid crystals. Additionally, the density of the microarray could be adjusted by controlling the surface coverage of assembled molecules. Based on the hybrid microarray modified electrode with a large specific area (ca. 10 times its geometrical area), a label-free electrochemical DNA biosensor was constructed for the detection of an oligonucleotide fragment of the avian flu virus H5N1. The DNA biosensor displayed a significantly low detection limit of 5 pM (S/N = 3), a wide linear response from 10 pM to 10 nM, as well as excellent selectivity, good regeneration and high stability. We expect that the proposed template-free method can provide a new reference for the fabrication of a highly oriented hybrid array and the as-prepared microarray modified electrode will be a promising paradigm in constructing highly sensitive and selective biosensors.Highly oriented growth of a hybrid microarray was realized by a facile template-free method on gold substrates for the first time. The proposed formation mechanism involves an interfacial structure-directing force arising from self-assembled monolayers (SAMs) between gold substrates and hybrid crystals. Different SAMs and variable surface coverage of the assembled molecules play a critical role in the interfacial directing forces and

  17. Solvothermal removal of the organic template from L{sub 3} ('sponge') templated silica monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Dabbs, Daniel M. [Princeton University, Department of Chemical Engineering (United States); Mulders, Norbert [University of Delaware, Department of Physics and Astronomy (United States); Aksay, Ilhan A. [Princeton University, Department of Chemical Engineering (United States)], E-mail: iaksay@princeton.EDU


    We compare the methods of continuous solvent (Soxhlet) and supercritical solvent extractions for the removal of the organic template from nanostructured silica monoliths. Our monoliths are formed by templating the L{sub 3} liquid crystal phase of cetylpyridinium chloride in aqueous solutions with tetramethoxy silane. The monoliths that result from both Soxhlet and supercritical extraction methods are mechanically robust, optically clear, and free of cracks. The Soxhlet method compares favorably with supercritical solvent extraction in that equivalent L{sub 3}-templated silica can be synthesized without the use of specialized reactor hardware or higher temperatures and high pressures, while avoiding noxious byproducts. The comparative effectiveness of various solvents in the Soxhlet process is related to the Hildebrand solubility parameter, determined by the effective surface area of the extracted silica.

  18. Mechanisms of lymphatic regeneration after tissue transfer.

    Directory of Open Access Journals (Sweden)

    Alan Yan

    Full Text Available INTRODUCTION: Lymphedema is the chronic swelling of an extremity that occurs commonly after lymph node resection for cancer treatment. Recent studies have demonstrated that transfer of healthy tissues can be used as a means of bypassing damaged lymphatics and ameliorating lymphedema. The purpose of these studies was to investigate the mechanisms that regulate lymphatic regeneration after tissue transfer. METHODS: Nude mice (recipients underwent 2-mm tail skin excisions that were either left open or repaired with full-thickness skin grafts harvested from donor transgenic mice that expressed green fluorescent protein in all tissues or from LYVE-1 knockout mice. Lymphatic regeneration, expression of VEGF-C, macrophage infiltration, and potential for skin grafting to bypass damaged lymphatics were assessed. RESULTS: Skin grafts healed rapidly and restored lymphatic flow. Lymphatic regeneration occurred beginning at the peripheral edges of the graft, primarily from ingrowth of new lymphatic vessels originating from the recipient mouse. In addition, donor lymphatic vessels appeared to spontaneously re-anastomose with recipient vessels. Patterns of VEGF-C expression and macrophage infiltration were temporally and spatially associated with lymphatic regeneration. When compared to mice treated with excision only, there was a 4-fold decrease in tail volumes, 2.5-fold increase in lymphatic transport by lymphoscintigraphy, 40% decrease in dermal thickness, and 54% decrease in scar index in skin-grafted animals, indicating that tissue transfer could bypass damaged lymphatics and promote rapid lymphatic regeneration. CONCLUSIONS: Our studies suggest that lymphatic regeneration after tissue transfer occurs by ingrowth of lymphatic vessels and spontaneous re-connection of existing lymphatics. This process is temporally and spatially associated with VEGF-C expression and macrophage infiltration. Finally, tissue transfer can be used to bypass damaged lymphatics

  19. Investigation of Terminology Coverage in Radiology Reporting Templates and Free‐text Reports

    Directory of Open Access Journals (Sweden)

    Yi Hong


    Full Text Available The Radiological Society of North America (RSNA is improving reporting practices by developing an online library of clear and consistent report templates. To compare term occurrences in free‐text radiology reports and RSNA reporting templates, the Wilcoxon signed‐rank test method was applied to investigate how much of the content of conventional narrative reports is covered by the terms included in the RSNA reporting templates. The results show that the RSNA reporting templates cover most terms that appear in actual radiology reports. The Wilcoxon test may be helpful in evaluatingexisting templates and guiding the enhancement of reporting templates.

  20. Lens regeneration in axolotl: new evidence of developmental plasticity

    Directory of Open Access Journals (Sweden)

    Suetsugu-Maki Rinako


    Full Text Available Abstract Background Among vertebrates lens regeneration is most pronounced in newts, which have the ability to regenerate the entire lens throughout their lives. Regeneration occurs from the dorsal iris by transdifferentiation of the pigment epithelial cells. Interestingly, the ventral iris never contributes to regeneration. Frogs have limited lens regeneration capacity elicited from the cornea during pre-metamorphic stages. The axolotl is another salamander which, like the newt, regenerates its limbs or its tail with the spinal cord, but up until now all reports have shown that it does not regenerate the lens. Results Here we present a detailed analysis during different stages of axolotl development, and we show that despite previous beliefs the axolotl does regenerate the lens, however, only during a limited time after hatching. We have found that starting at stage 44 (forelimb bud stage lens regeneration is possible for nearly two weeks. Regeneration occurs from the iris but, in contrast to the newt, regeneration can be elicited from either the dorsal or the ventral iris and, occasionally, even from both in the same eye. Similar studies in the zebra fish concluded that lens regeneration is not possible. Conclusions Regeneration of the lens is possible in the axolotl, but differs from both frogs and newts. Thus the axolotl iris provides a novel and more plastic strategy for lens regeneration.

  1. Gene expression profile of the regeneration epithelium during axolotl limb regeneration. (United States)

    Campbell, Leah J; Suárez-Castillo, Edna C; Ortiz-Zuazaga, Humberto; Knapp, Dunja; Tanaka, Elly M; Crews, Craig M


    Urodele amphibians are unique among adult vertebrates in their ability to regenerate missing limbs. The process of limb regeneration requires several key tissues including a regeneration-competent wound epidermis called the regeneration epithelium (RE). We used microarray analysis to profile gene expression of the RE in the axolotl, a Mexican salamander. A list of 125 genes and expressed sequence tags (ESTs) showed a ≥1.5-fold expression in the RE than in a wound epidermis covering a lateral cuff wound. A subset of the RE ESTs and genes were further characterized for expression level changes over the time-course of regeneration. This study provides the first large scale identification of specific gene expression in the RE.

  2. TISSUE REGENERATION. Inhibition of the prostaglandin-degrading enzyme 15-PGDH potentiates tissue regeneration. (United States)

    Zhang, Yongyou; Desai, Amar; Yang, Sung Yeun; Bae, Ki Beom; Antczak, Monika I; Fink, Stephen P; Tiwari, Shruti; Willis, Joseph E; Williams, Noelle S; Dawson, Dawn M; Wald, David; Chen, Wei-Dong; Wang, Zhenghe; Kasturi, Lakshmi; Larusch, Gretchen A; He, Lucy; Cominelli, Fabio; Di Martino, Luca; Djuric, Zora; Milne, Ginger L; Chance, Mark; Sanabria, Juan; Dealwis, Chris; Mikkola, Debra; Naidoo, Jacinth; Wei, Shuguang; Tai, Hsin-Hsiung; Gerson, Stanton L; Ready, Joseph M; Posner, Bruce; Willson, James K V; Markowitz, Sanford D


    Agents that promote tissue regeneration could be beneficial in a variety of clinical settings, such as stimulating recovery of the hematopoietic system after bone marrow transplantation. Prostaglandin PGE2, a lipid signaling molecule that supports expansion of several types of tissue stem cells, is a candidate therapeutic target for promoting tissue regeneration in vivo. Here, we show that inhibition of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a prostaglandin-degrading enzyme, potentiates tissue regeneration in multiple organs in mice. In a chemical screen, we identify a small-molecule inhibitor of 15-PGDH (SW033291) that increases prostaglandin PGE2 levels in bone marrow and other tissues. SW033291 accelerates hematopoietic recovery in mice receiving a bone marrow transplant. The same compound also promotes tissue regeneration in mouse models of colon and liver injury. Tissues from 15-PGDH knockout mice demonstrate similar increased regenerative capacity. Thus, 15-PGDH inhibition may be a valuable therapeutic strategy for tissue regeneration in diverse clinical contexts.

  3. Detection of cancerous masses in mammograms by template matching: optimization of template brightness distribution by means of evolutionary algorithm. (United States)

    Bator, Marcin; Nieniewski, Mariusz


    Optimization of brightness distribution in the template used for detection of cancerous masses in mammograms by means of correlation coefficient is presented. This optimization is performed by the evolutionary algorithm using an auxiliary mass classifier. Brightness along the radius of the circularly symmetric template is coded indirectly by its second derivative. The fitness function is defined as the area under curve (AUC) of the receiver operating characteristic (ROC) for the mass classifier. The ROC and AUC are obtained for a teaching set of regions of interest (ROIs), for which it is known whether a ROI is true-positive (TP) or false-positive (F). The teaching set is obtained by running the mass detector using a template with a predetermined brightness. Subsequently, the evolutionary algorithm optimizes the template by classifying masses in the teaching set. The optimal template (OT) can be used for detection of masses in mammograms with unknown ROIs. The approach was tested on the training and testing sets of the Digital Database for Screening Mammography (DDSM). The free-response receiver operating characteristic (FROC) obtained with the new mass detector seems superior to the FROC for the hemispherical template (HT). Exemplary results are the following: in the case of the training set in the DDSM, the true-positive fraction (TPF) = 0.82 for the OT and 0.79 for the HT; in the case of the testing set, TPF = 0.79 for the OT and 0.72 for the HT. These values were obtained for disease cases, and the false-positive per image (FPI) = 2.

  4. Resin regeneration device for condensate desalter

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, Yoshihiro [Toshiba Engineering Co. Ltd., Kawasaki, Kanagawa (Japan); Hirose, Yuki


    The present invention provides a resin regeneration device for a condensate desalter of a nuclear power plant. Namely, both anionic and cationic exchange resins are supplied in a mixed state from a forwarding water desalting tower to an anionic resin regeneration tower. In the anionic resin generation tower, the resin is once separated to an anionic exchange region layer, a mixed resin layer and an cationic exchange resin layer in this order from the upper portion by water injected from a stirring water injection tube disposed at the bottom. Then, water is injected from a developing water injection tube disposed at the lower portion of the mixed resin layer to develop the cationic exchange resin layer and the mixed resin layer to the upper portion of the cationic resin regeneration tower. Subsequently, the amount of the injection of the developing water is reduced to such a flow rate that only the anionic exchange resin is precipitated. Then, a cationic exchange resin layer is formed at the upper portion and an anion exchange resin layer is formed at the lower portion of the developing water injection tube of the cationic resin regeneration tower. The anionic exchange resin is transferred to the anionic exchange resin regeneration tower in this state. According to the present invention, the mixed resin layer can be separated to anionic and cationic exchange resins easily and reliably. (I.S.)

  5. Apoptosis, stem cells, and tissue regeneration. (United States)

    Bergmann, Andreas; Steller, Hermann


    Most metazoans have at least some ability to regenerate damaged cells and tissues, although the regenerative capacity varies depending on the species, organ, or developmental stage. Cell replacement and regeneration occur in two contexts: renewal of spent cells during tissue homeostasis (homeostatic growth), and in response to external injury, wounding, or amputation (epimorphic regeneration). Model organisms that display remarkable regenerative capacity include amphibians, planarians, Hydra, and the vertebrate liver. In addition, several mammalian organs--including the skin, gut, kidney, muscle, and even the human nervous system--have some ability to replace spent or damaged cells. Although the regenerative response is complex, it typically involves the induction of new cell proliferation through formation of a blastema, followed by cell specification, differentiation, and patterning. Stem cells and undifferentiated progenitor cells play an important role in both tissue homeostasis and tissue regeneration. Stem cells are typically quiescent or passing slowly through the cell cycle in adult tissues, but they can be activated in response to cell loss and wounding. A series of studies, mostly performed in Drosophila as well as in Hydra, Xenopus, and mouse, has revealed an unexpected role of apoptotic caspases in the production of mitogenic signals that stimulate the proliferation of stem and progenitor cells to aid in tissue regeneration. This Review summarizes some of the key findings and discusses links to stem cell biology and cancer.

  6. Unexpected regeneration in middle-aged mice. (United States)

    Reines, Brandon; Cheng, Lily I; Matzinger, Polly


    Complete regeneration of damaged extremities, including both the epithelium and the underlying tissues, is thought to occur mainly in embryos, fetuses, and juvenile mammals, but only very rarely in adult mammals. Surprisingly, we found that common strains of mice are able to regenerate all of the tissues necessary to completely fill experimentally punched ear holes, but only if punched at middle age. Although young postweaning mice regrew the epithelium without typical pre-scar granulation tissue, they showed only minimal regeneration of connective tissues. In contrast, mice punched at 5-11 months of age showed true amphibian-like blastema formation and regrowth of cartilage, fat, and dermis, with blood vessels, sebaceous glands, hair follicles, and, in black mice, melanocytes. These data suggest that at least partial appendage regeneration may be more common in adult mammals than previously thought and call into question the common view that regenerative ability is lost with age. The data suggest that the age at which various inbred mouse strains become capable of epimorphic regeneration may be correlated with adult body weight.

  7. Nicotinamide adenine dinucleotide biosynthesis promotes liver regeneration. (United States)

    Mukherjee, Sarmistha; Chellappa, Karthikeyani; Moffitt, Andrea; Ndungu, Joan; Dellinger, Ryan W; Davis, James G; Agarwal, Beamon; Baur, Joseph A


    The regenerative capacity of the liver is essential for recovery from surgical resection or injuries induced by trauma or toxins. During liver regeneration, the concentration of nicotinamide adenine dinucleotide (NAD) falls, at least in part due to metabolic competition for precursors. To test whether NAD availability restricts the rate of liver regeneration, we supplied nicotinamide riboside (NR), an NAD precursor, in the drinking water of mice subjected to partial hepatectomy. NR increased DNA synthesis, mitotic index, and mass restoration in the regenerating livers. Intriguingly, NR also ameliorated the steatosis that normally accompanies liver regeneration. To distinguish the role of hepatocyte NAD levels from any systemic effects of NR, we generated mice overexpressing nicotinamide phosphoribosyltransferase, a rate-limiting enzyme for NAD synthesis, specifically in the liver. Nicotinamide phosphoribosyltransferase overexpressing mice were mildly hyperglycemic at baseline and, similar to mice treated with NR, exhibited enhanced liver regeneration and reduced steatosis following partial hepatectomy. Conversely, mice lacking nicotinamide phosphoribosyltransferase in hepatocytes exhibited impaired regenerative capacity that was completely rescued by administering NR.

  8. Regeneration in Echinoderms: repair, regrowth, cloning

    Directory of Open Access Journals (Sweden)

    MD Candia Carnevali


    Full Text Available Regenerative potential is expressed to a maximum extent in echinoderms. It is a commonphenomenon in all the classes, extensively employed to reconstruct external appendages and internalorgans often subjected to amputation, self-induced or traumatic, rapidly followed by completesuccessful re-growth of the lost parts. Regeneration has been studied in adult individuals as well as inlarvae. In armed echinoderms, regeneration of arms is obviously frequent: in many cases, thedetached body fragments can undergo phenomena of partial or total regeneration independently of thedonor animal, and, in a few cases (asteroids, the individual autotomised arms can even regenerate toproduce new complete adults, offering superb examples of cloning strategies. In the species examinedso far most results throw light on aspects related to wound healing, growth, morphogenesis anddifferentiation, even though in most cases many crucial questions remain unanswered. The presentpaper provides an overview of the current understanding of the phenomenon and covers the mainbiological aspects of regeneration giving an idea of the “state of the art” across the phylum in terms ofexperimental approaches and representative models.

  9. Thinning in artificially regenerated young beech stands

    Directory of Open Access Journals (Sweden)

    Novák Jiří


    Full Text Available Although beech stands are usually regenerated naturally, an area of up to 5,000 ha year−1 is artificially regenerated by beech in the Czech Republic annually. Unfortunately, these stands often showed insufficient stand density and, consequently, lower quality of stems. Therefore, thinning methods developed for naturally regenerated beech stands are applicable with difficulties. The paper evaluates the data from two thinning experiments established in young artificially regenerated beech stands located in different growing conditions. In both experiments, thinning resulted in the lower amount of salvage cut in following years. Positive effect of thinning on periodic stand basal area increment and on periodic diameter increment of dominant trees was found in the beech stand located at middle elevations. On the other hand, thinning effects in mountain conditions were negligible. Thinning focusing on future stand quality cannot be commonly applied in artificially regenerated beech stands because of their worse initial quality and lower density. However, these stands show good growth and response to thinning, hence their management can be focused on maximising beech wood production.

  10. Equine model for soft-tissue regeneration. (United States)

    Bellas, Evangelia; Rollins, Amanda; Moreau, Jodie E; Lo, Tim; Quinn, Kyle P; Fourligas, Nicholas; Georgakoudi, Irene; Leisk, Gary G; Mazan, Melissa; Thane, Kristen E; Taeymans, Olivier; Hoffman, A M; Kaplan, D L; Kirker-Head, C A


    Soft-tissue regeneration methods currently yield suboptimal clinical outcomes due to loss of tissue volume and a lack of functional tissue regeneration. Grafted tissues and natural biomaterials often degrade or resorb too quickly, while most synthetic materials do not degrade. In previous research we demonstrated that soft-tissue regeneration can be supported using silk porous biomaterials for at least 18 months in vivo in a rodent model. In the present study, we scaled the system to a survival study using a large animal model and demonstrated the feasibility of these biomaterials for soft-tissue regeneration in adult horses. Both slow and rapidly degrading silk matrices were evaluated in subcutaneous pocket and intramuscular defect depots. We showed that we can effectively employ an equine model over 6 months to simultaneously evaluate many different implants, reducing the number of animals needed. Furthermore, we were able to tailor matrix degradation by varying the initial format of the implanted silk. Finally, we demonstrate ultrasound imaging of implants to be an effective means for tracking tissue regeneration and implant degradation.

  11. Telocytes in liver regeneration: possible roles. (United States)

    Wang, Fei; Song, Yang; Bei, Yihua; Zhao, Yingying; Xiao, Junjie; Yang, Changqing


    Telocytes (TCs) are a novel type of interstitial cells which are potentially involved in tissue regeneration and repair ( Previously, we documented the presence of TCs in liver. However, the possible roles of TCs in liver regeneration remain unknown. In this study, a murine model of partial hepatectomy (PH) was used to induce liver regeneration. The number of TCs detected by double labelling immunofluorescence methods (CD34/PDGFR-α, CD34/PDGFR-ß and CD34/Vimentin) was significantly increased when a high level of hepatic cell proliferation rate (almost doubled) as shown by 5-ethynyl-2'-deoxyuridine (EdU) immunostaining and Western Blot of Proliferating cell nuclear antigen (PCNA) was found at 48 and 72 hrs post-PH. Meanwhile, the number of CK-19 positive-hepatic stem cells peaked at 72 hrs post-PH, co-ordinating with the same time-point, when the number of TCs was most significantly increased. Taken together, the results indicate a close relationship between TCs and the cells essentially involved in liver regeneration: hepatocytes and stem cells. It remains to be determined how TCs affect hepatocytes proliferation and/or hepatic stem cell differentiation in liver regeneration. Besides intercellular junctions, we may speculate a paracrine effect via ectovesicles.

  12. Orthopaedic tissue engineering and bone regeneration. (United States)

    Dickson, Glenn; Buchanan, Fraser; Marsh, David; Harkin-Jones, Eileen; Little, Uel; McCaigue, Mervyn


    Orthopaedic tissue engineering combines the application of scaffold materials, cells and the release of growth factors. It has been described as the science of persuading the body to reconstitute or repair tissues that have failed to regenerate or heal spontaneously. In the case of bone regeneration 3-D scaffolds are used as a framework to guide tissue regeneration. Mesenchymal cells obtained from the patient via biopsy are grown on biomaterials in vitro and then implanted at a desired site in the patient's body. Medical implants that encourage natural tissue regeneration are generally considered more desirable than metallic implants that may need to be removed by subsequent intervention. Numerous polymeric materials, from natural and artificial sources, are under investigation as substitutes for skeletal elements such as cartilage and bone. For bone regeneration, cells (obtained mainly from bone marrow aspirate or as primary cell outgrowths from bone biopsies) can be combined with biodegradable polymeric materials and/or ceramics and absorbed growth factors so that osteoinduction is facilitated together with osteoconduction; through the creation of bioactive rather than bioinert scaffold constructs. Relatively rapid biodegradation enables advantageous filling with natural tissue while loss of polymer strength before mass is disadvantageous. Innovative solutions are required to address this and other issues such as the biocompatibility of material surfaces and the use of appropriate scaffold topography and porosity to influence bone cell gene expression.

  13. The Molecular and Cellular Choreography of Appendage Regeneration. (United States)

    Tanaka, Elly M


    Recent advances in limb regeneration are revealing the molecular events that integrate growth control, cell fate programming, and positional information to yield the exquisite replacement of the amputated limb. Parallel progress in several invertebrate and vertebrate models has provided a broader context for understanding the mechanisms and the evolution of regeneration. Together, these discoveries provide a foundation for describing the principles underlying regeneration of complex, multi-tissue structures. As such these findings should provide a wealth of ideas for engineers seeking to reconstitute regeneration from constituent parts or to elicit full regeneration from partial regeneration events.

  14. Study on Regeneration of MDEA Solution Using Membrane Distillation

    Institute of Scientific and Technical Information of China (English)

    Cai Pei; Wang Shuli; Zhao Shuhua


    Treating acid gases contained in natural gas by MDEA is used widely.But the efficiency of regeneration of the MDEA solution limited the development of this technology.An optimal temperature is necessary for regeneration of the MDEA solution using membrane distillation.The experiment results showed that the regeneration rate of MDEA rose with an increasing temperature.But the rate increased slowly after the regeneration temperature arrived at a certain value.This study can confirm that regeneration of the MDEA solution using membrane distillation is feasible.This technology provides more advantages as compared to conventional regeneration process.

  15. Raamovereenkomst digitale archiveringsdienst : Template Digital Archiving Services Agreement

    NARCIS (Netherlands)


    textabstractThis template for a Digital Archiving Services Agreement between NISV and non broadcast data producers (i.c. dataproducers from outside of the public broadcast environment ) contains all arrangements and services to be mutually agreed on, as to the data formats and metadata items to be i

  16. Efficient multi-site-directed mutagenesis directly from genomic template

    Indian Academy of Sciences (India)

    Fengtao Luo; Xiaolan Du; Tujun Weng; Xuan Wen; Junlan Huang; Lin Chen


    In this article, the traditional multi-site-directed mutagenesis method based on overlap extension PCR was improved specifically for complicated templates, such as genomic sequence or complementary DNA. This method was effectively applied for multi-site-directed mutagenesis directly from mouse genomic DNA, as well as for combination, deletion or insertion of DNA fragments.

  17. Fluids as Dynamic Templates for Cytoskeletal Proteins in Plant Cells

    CERN Document Server

    Lofthouse, J T


    The Dynamic Template model of biological cell membranes and the cytoplasm as spatially organised fluid layers is extended to plant cells, and is shown to offer a feasible shear driven mechanism for the co-alignment of internal and external fibres observed during growth and tropic responses

  18. 16 CFR Figure 9 to Part 1610 - Brushing Device Template (United States)


    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Brushing Device Template 9 Figure 9 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF CLOTHING TEXTILES Pt.1610, Fig. 9 Figure 9 to Part 1610—Brushing...

  19. Abbreviated Pandemic Influenza Planning Template for Primary Care Offices

    Energy Technology Data Exchange (ETDEWEB)



    The Abbreviated Pandemic Influenza Plan Template for Primary Care Provider Offices is intended to assist primary care providers and office managers with preparing their offices for quickly putting a plan in place to handle an increase in patient calls and visits, whether during the 2009-2010 influenza season or future influenza seasons.

  20. Enzyme Activity and Biomolecule Templating at Liquid and Solid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Harvey W. Blanch


    There are two main components of this research program. The first involves studies of the adsorption and catalytic activity of proteins at fluid-fluid and fluid-solid interfaces; the second employs biological macromolecules as templates at the solid-liquid interface for controlled crystallization of inorganic materials, to provide materials with specific functionality.

  1. Nanomolar determination of Pb (II ions by selective templated electrode

    Directory of Open Access Journals (Sweden)

    Mazloum-Ardakani Mohammad


    Full Text Available Polypyrrole modified electrode, prepared by electropolymerization of pyrrole in the presence of methyl red as a dopant, was templated with respect to Pb2+ ion and applied for potentiometric and voltammetric detection of this ion. The templating process improved the analytical response characteristics of the electrode, specially their selectivity, with respect to Pb2+ ion. The improvement depends on both the incorporated ligand (dopant and the templating process, with the latter being more vital. The potentiometric response of the electrode was linear within the Pb2+ concentration range of 2.0×10-6 to 5.0×10-2 M with a near-Nernstian slope of 28.6 mV decade-1 and a detection limit of 7.0 ×10-7 M. The electrode was also used for preconcentration differential pulse anodic stripping voltammetry (DPASV and results showed that peak currents for the incorporated lead species were dependent on the metal ion concentration in the range of 1.0×10-8 to 1.0×10-3 M. The detection limit of DPASV method was 3.5 ×10-9 M. The selectivity of the electrode with respect to some transition metal ions was investigated. The modified-templated electrode was used for the successful assay of lead in two standard reference material samples.

  2. New NIR light-curve templates for classical Cepheids

    CERN Document Server

    Inno, L; Romaniello, M; Bono, G; Monson, A; Ferraro, I; Iannicola, G; Persson, E; Buonanno, R; Freedman, W; Gieren, W; Groenewegen, M A T; Ita, Y; Laney, C D; Lemasle, B; Madore, B F; Nagayama, T; Nakada, Y; Nonino, M; Pietrzynski, G; Primas, F; Scowcroft, V; Soszynski, I; Tanabe, T; Udalski, A


    We present new near-infrared (NIR) light-curve templates for fundamental (FU, JHK) and first overtone (FO, J) Cepheids. The new templates together with PL and PW relations provide Cepheid distances from single-epoch observations with a precision only limited by the intrinsic accuracy of the method adopted. The templates rely on a very large set of Galactic and Magellanic Clouds (MCs) Cepheids (FU,~600; FO,~200) with well sampled NIR (IRSF data) and optical (V,I; OGLE data) light curves. To properly trace the change in the shape of the light curve as a function of period, we split the sample of calibrating Cepheids into 10 different period bins. The templates for the first time cover FO Cepheids and the FU short-period Cepheids (P<5 days). Moreover, the zero-point phase is anchored to the phase of the mean magnitude along the rising branch. The new approach has several advantages in sampling the light curve of bump Cepheids when compared with the phase of maximum light. We also provide new estimates of the ...

  3. Template Transfer Nanoimprint for Uniform Nanopores and Nanopoles

    Directory of Open Access Journals (Sweden)

    Jianjun Li


    Full Text Available A new methodology is developed for the fabrication of nanostructures on substrate based on anodized Al2O3 (AAO porous template transfer process. It includes (1 forming amorphous alloy, negative UV-resist resin (i.e., SU-8, or PMMA (polymethylmethacrylate plate nanorod arrays by hot-press molding amorphous alloy, negative UV-resist resin (i.e., SU-8, or PMMA plate into the anodized Al2O3 porous substrates; (2 removing AAO templates by chemical etching process after suitable posttreatment (annealing and/or irradiation to improve the mechanical strength of the nanorod arrays; (3 reforming nanopore films by hot-embossing the nanorod arrays into a thin layer of polymer film on substrates (e.g., silica; (4 cleaning the bottom residues in pores of the films by oxygen plasmon. The results indicate that the diameters of amorphous alloy (or negative UV-resist resin or PMMA nanorod arrays can be ranged from 32 nm to 200 nm. The diameters of the imprinted ILR-1050 photoresist nanopores are about 94.5 ± 12.2 nm and the diameters of the imprinted or SU-8 resin on glass slides nanopores are about 207 ± 26.4 nm, which inherit the diameters of AAO templates. This methodology provides a general method to fabricate nanorods arrays and/or thin nanopore films by template transfer nanoimprint process.

  4. Utility Templates for the Interpretation of Conditional Statements (United States)

    Bonnefon, Jean-Francois; Haigh, Matthew; Stewart, Andrew J.


    People often use conditional statements to describe configurations of agents, actions and valued consequences. In this paper we propose the existence of utility templates, a special subset of these configurations that exert strong constraints on how people interpret conditionals. We conducted an initial completion survey which identified four…

  5. Magnetic and conductive magnetite nanowires by DNA-templating. (United States)

    Mohamed, Hasan Daw A; Watson, Scott M D; Horrocks, Benjamin R; Houlton, Andrew


    The synthesis of nanowires made of magnetite (Fe(3)O(4)) phase iron oxide was achieved using DNA as a template to direct formation of the metal oxide and confine its growth in two dimensions. This simple solution-based approach involves initial association of Fe(2+) and Fe(3+) to the DNA "template" molecules, and subsequent co-precipitation of the Fe(3)O(4) material, upon increasing the solution pH, to give the final metal oxide nanowires. Analysis of the DNA-templated material, using a combination of FTIR, XRD, XPS, and Raman spectroscopy, confirmed the iron oxide formed to be the Fe(3)O(4) crystal phase. Investigation of the structural character of the nanowires, carried out by AFM, revealed the metal oxide to form regular coatings of nanometre-scale thickness around the DNA templates. Statistical analysis showed the size distribution of the nanowires to follow a trimodal model, with the modal diameter values identified as 5-6 nm, 14-15 nm, and 23-24 nm. Additional scanning probe microscopy techniques (SCM, MFM) were also used to verify that the nanowire structures are electrically conducting and exhibit magnetic behaviour. Such properties, coupled with the small dimensions of these materials, make them potentially good candidates for application in a host of future nanoscale device technologies.

  6. General Template for the FMEA Applications in Primary Food Processing. (United States)

    Özilgen, Sibel; Özilgen, Mustafa


    Data on the hazards involved in the primary steps of processing cereals, fruit and vegetables, milk and milk products, meat and meat products, and fats and oils are compiled with a wide-ranging literature survey. After determining the common factors from these data, a general FMEA template is offered, and its use is explained with a case study on pasteurized milk production.

  7. Exploring Many-Core Design Templates for FPGAs and ASICs

    Directory of Open Access Journals (Sweden)

    Ilia Lebedev


    Full Text Available We present a highly productive approach to hardware design based on a many-core microarchitectural template used to implement compute-bound applications expressed in a high-level data-parallel language such as OpenCL. The template is customized on a per-application basis via a range of high-level parameters such as the interconnect topology or processing element architecture. The key benefits of this approach are that it (i allows programmers to express parallelism through an API defined in a high-level programming language, (ii supports coarse-grained multithreading and fine-grained threading while permitting bit-level resource control, and (iii reduces the effort required to repurpose the system for different algorithms or different applications. We compare template-driven design to both full-custom and programmable approaches by studying implementations of a compute-bound data-parallel Bayesian graph inference algorithm across several candidate platforms. Specifically, we examine a range of template-based implementations on both FPGA and ASIC platforms and compare each against full custom designs. Throughout this study, we use a general-purpose graphics processing unit (GPGPU implementation as a performance and area baseline. We show that our approach, similar in productivity to programmable approaches such as GPGPU applications, yields implementations with performance approaching that of full-custom designs on both FPGA and ASIC platforms.

  8. Developing Gold Nanowires by Galvanic Replication of Ion Track Templates

    Institute of Scientific and Technical Information of China (English)


    @@ Scientists at the CAS Institute of Modern Physics (IMP) in Lanzhou, capital of northwest China's Gansu Province, recently made an essential advance in production and investigation of single- and polycrystalline gold nanowires by galvanic replication of ion track templates. Their work was published by the Nanotechnology (Vol. 17, 1922-1926, 2006).

  9. Template Authoring Environment for the Automatic Generation of Narrative Content (United States)

    Caropreso, Maria Fernanda; Inkpen, Diana; Keshtkar, Fazel; Khan, Shahzad


    Natural Language Generation (NLG) systems can make data accessible in an easily digestible textual form; but using such systems requires sophisticated linguistic and sometimes even programming knowledge. We have designed and implemented an environment for creating and modifying NLG templates that requires no programming knowledge, and can operate…

  10. Black silicon maskless templates for carbon nanotube forests

    DEFF Research Database (Denmark)

    Wierzbicki, Rafal; Schmidt, Michael Stenbæk; Boisen, Anja


    We present here a proof of concept for a novel fabrication method of vertically aligned carbon nanotube forests, utilizing black silicon nanograss (a forest of silicon nanometer-sized spikes created with reactive ion etching) coated with titanium tungsten diffusion barrier as a template. The meth...

  11. Detection of GW bursts with chirplet-like template families

    Energy Technology Data Exchange (ETDEWEB)

    Chassande Mottin, Eric; Miele, Miriam [CNRS and Univ. Paris Denis Diderot, AstroParticule et Cosmologie (France); Mohapatra, Satya; Cadonati, Laura, E-mail: ecm@apc.univ-paris7.f [Physics Department, University of Massachusetts, Amherst MA 01003 (United States)


    Gravitational wave (GW) burst detection algorithms typically rely on the hypothesis that the burst signal is 'locally stationary', that is with slow variations of its frequency. Under this assumption, the signal can be decomposed into a small number of wavelets with constant frequency. This justifies the use of a family of sine-Gaussian wavelets in the Omega pipeline, one of the algorithms used in LIGO-Virgo burst searches. However, there are plausible scenarios where the burst frequency evolves rapidly, such as in the merger phase of a binary black-hole and/or neutron-star coalescence. In those cases, the local stationarity of sine Gaussians induces performance losses, due to the mismatch between the template and the actual signal. We propose an extension of the Omega pipeline based on chirplet-like templates. Chirplets incorporate an additional parameter, the chirp rate, to control the frequency variation. In this paper, we show that the Omega pipeline can easily be extended to include a chirplet template bank. We illustrate the method on a simulated data set, with a family of phenomenological binary black-hole coalescence waveforms embedded into Gaussian LIGO/Virgo-like noise. Chirplet-like templates result in an enhancement of the measured signal-to-noise ratio.


    Directory of Open Access Journals (Sweden)



    Full Text Available We report here the preparation of nanoparticles of iron oxide in the presence of polysaccharidetemplates. Interaction between iron sulfate and template has been carried out in aqueous phase,followed by the selective and controlled removal of the template to achieve narrow distribution ofparticle size. Particles of iron oxide obtained have been characterized for their stability in solventmedia, size, size distribution and crystallinity and it was found that when the negative value of thezeta potential increases, particle size decreases. A narrow particle size distribution with D100 = 275nm was obtained with chitosan and starch templates. SEM measurements further confirm the particlesize measurement. Diffuse reflectance UV–VIS spectra values show that the template is completelyremoved from the final iron oxide particles and powder XRD measurements show that the peaks ofthe diffractogram are in agreement with the theoretical data of hematite. The salient observations ofour study shows that there occurs a direct correlation between zeta potential, polydispersity index,band gap energy and particle size. The crystallite size of the particles was found to be 30–35 nm. Alarge negative zeta potential was found to be advantageous for achieving lower particle sizes, as theparticles remained discrete without agglomeration.

  13. Computer-aided modelling template: Concept and application

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul


    decomposition technique which identifies generic steps and workflow involved, the computer-aided template concept has been developed. This concept is implemented as a software tool, which provides a user-friendly interface for following the workflow steps and guidance through the steps providing additional...

  14. Higher Accuracy Template for Corner Cube Reflected Image

    Energy Technology Data Exchange (ETDEWEB)

    Awwal, A S; Rice, K L; Leach, R R; Taha, T M


    Video images of laser beams are analyzed to determine the position of the laser beams for alignment purpose in the National Ignition Facility (NIF). Algorithms process beam images to facilitate automated laser alignment. One such beam image, known as the corner cube reflected pinhole image, exhibits wide beam quality variations that are processed by a matched-filter-based algorithm. The challenge is to design a representative template that captures these variations while at the same time assuring accurate position determination. This paper describes the development of a new analytical template to accurately estimate the center of a beam with good image quality. The templates are constructed to exploit several key recurring features observed in the beam images. When the beam image quality is low, the algorithm chooses a template that contains fewer features. The algorithm was implemented using a Xilinx Virtex II Pro FPGA implementation that provides a speedup of about 6.4 times over a baseline 3GHz Pentium 4 processor.

  15. Open Access Policy Guidelines and Template for Funders


    Tsoukala, Victoria; Angelaki, Marina


    The present guidelines aim to assist in the development of efficient Open Access policies among Funders.  They provide the context, the process and a model policy (template) that will enable Funders to develop and implement their own Open Access policy. 

  16. PEOPLE COUNTING WITH STEREO CAMERAS: Two Template-based Solutions

    NARCIS (Netherlands)

    Van Oosterhout, Tim; Kröse, Ben; Englebienne, Gwenn


    People counting is a challenging task with many applications. We propose a method with a fixed stereo camera that is based on projecting a template onto the depth image. The method was tested on a challenging outdoor dataset with good results and runs in real time.

  17. Julius – a template based supplementary electronic health record system

    Directory of Open Access Journals (Sweden)

    Klein Gunnar O


    Full Text Available Abstract Background EHR systems are widely used in hospitals and primary care centres but it is usually difficult to share information and to collect patient data for clinical research. This is partly due to the different proprietary information models and inconsistent data quality. Our objective was to provide a more flexible solution enabling the clinicians to define which data to be recorded and shared for both routine documentation and clinical studies. The data should be possible to reuse through a common set of variable definitions providing a consistent nomenclature and validation of data. Another objective was that the templates used for the data entry and presentation should be possible to use in combination with the existing EHR systems. Methods We have designed and developed a template based system (called Julius that was integrated with existing EHR systems. The system is driven by the medical domain knowledge defined by clinicians in the form of templates and variable definitions stored in a common data repository. The system architecture consists of three layers. The presentation layer is purely web-based, which facilitates integration with existing EHR products. The domain layer consists of the template design system, a variable/clinical concept definition system, the transformation and validation logic all implemented in Java. The data source layer utilizes an object relational mapping tool and a relational database. Results The Julius system has been implemented, tested and deployed to three health care units in Stockholm, Sweden. The initial responses from the pilot users were positive. The template system facilitates patient data collection in many ways. The experience of using the template system suggests that enabling the clinicians to be in control of the system, is a good way to add supplementary functionality to the present EHR systems. Conclusion The approach of the template system in combination with various local EHR

  18. Synthesis of porous carbon balls from spherical colloidal crystal templates. (United States)

    Kim, Youngchan; Cho, Chang-Yeol; Kang, Ji-Hwan; Cho, Young-Sang; Moon, Jun Hyuk


    Spherical inverse opal (IO) porous carbon was produced utilizing silica colloidal crystal spheres as templates. The spherical colloidal crystals were obtained through the self-assembly of monodisperse particles inside an emulsion droplet with confined geometry. The templates were inverted using a carbon precursor, phenol-formaldehyde (PF) resol. We demonstrated a two-step synthesis involving the subsequent infiltration of the PF resol precursor into the spherical colloidal crystal template and a one-step synthesis using a silica colloidal solution containing dissolved PF resol. In the former case, the sizes of the IO carbon balls were controlled by the size of the colloidal crystal templates, and diameters of a few micrometers up to 50 μm were obtained. The average diameter of the macropores created by the silica particles was 230 nm. Moreover, meso-/macroporous IO carbon balls were created using block-copolymer templates in the PF resol. In the one-step synthesis, the concentration of PF resol in the colloidal solution controlled the diameter of the IO carbon balls. IO balls smaller than 3 μm were obtained from the direct addition of 5% PF resol. The one-step synthesis produced rather irregular porous structures reflecting the less ordered crystallization processes inside the spherical colloidal crystals. Nitrogen adsorption and cyclic voltammetry measurements were conducted to measure the specific area and electroactive surface area of the IO carbon balls. The specific area of the mesopores-incorporated IO carbon balls was 1.3 times higher than that of bare IO carbon balls. Accordingly, the meso-/macroporous porous carbon balls exhibited higher electrocatalytic properties than the macroporous carbon balls.

  19. Bone marrow cells and myocardial regeneration. (United States)

    Wang, Fu-Sheng; Trester, Cathy


    Hematopoietic stem cell (HSC) plasticity and its clinical application have been studied profoundly in the past few years. Recent investigations indicate that HSC and other bone marrow stem cells can develop into other tissues. Because of the high morbidity and mortality of myocardial infarction and other heart disorders, myocardial regeneration is a good example of the clinical application of HSC plasticity in regenerative medicine. Preclinical studies in animals suggest that the use of this kind of treatment can reconstruct heart blood vessels, muscle, and function. Some clinical study results have been reported in the past 2 years. In 2003, reports of myocardial regeneration treatment increased significantly. Other studies include observations on the cell surface markers of transplanted cells and treatment efficacy. Some investigations, such as HSC testing, have focused on clinical applications using HSC plasticity and bone marrow transplantation to treat different types of disorders. In this review, we focus on the clinical application of bone marrow cells for myocardial regeneration.

  20. Evolution and developmental diversity of tooth regeneration. (United States)

    Tucker, Abigail S; Fraser, Gareth J


    This review considers the diversity observed during both the development and evolution of tooth replacement throughout the vertebrates in a phylogenetic framework from basal extant chondrichthyan fish and more derived teleost fish to mammals. We illustrate the conservation of the tooth regeneration process among vertebrate clades, where tooth regeneration refers to multiple tooth successors formed de novo for each tooth position in the jaws from a common set of retained dental progenitor cells. We discuss the conserved genetic mechanisms that might be modified to promote morphological diversity in replacement dentitions. We review current research and recent progress in this field during the last decade that have promoted our understanding of tooth diversity in an evolutionary developmental context, and show how tooth replacement and dental regeneration have impacted the evolution of the tooth-jaw module in vertebrates.

  1. Telomerase Is Essential for Zebrafish Heart Regeneration

    Directory of Open Access Journals (Sweden)

    Dorota Bednarek


    Full Text Available After myocardial infarction in humans, lost cardiomyocytes are replaced by an irreversible fibrotic scar. In contrast, zebrafish hearts efficiently regenerate after injury. Complete regeneration of the zebrafish heart is driven by the strong proliferation response of its cardiomyocytes to injury. Here we show that, after cardiac injury in zebrafish, telomerase becomes hyperactivated, and telomeres elongate transiently, preceding a peak of cardiomyocyte proliferation and full organ recovery. Using a telomerase-mutant zebrafish model, we found that telomerase loss drastically decreases cardiomyocyte proliferation and fibrotic tissue regression after cryoinjury and that cardiac function does not recover. The impaired cardiomyocyte proliferation response is accompanied by the absence of cardiomyocytes with long telomeres and an increased proportion of cardiomyocytes showing DNA damage and senescence characteristics. These findings demonstrate the importance of telomerase function in heart regeneration and highlight the potential of telomerase therapy as a means of stimulating cell proliferation upon myocardial infarction.

  2. Medicinal Chemistry Approaches to Heart Regeneration. (United States)

    Schade, Dennis; Plowright, Alleyn T


    Because of the minimal and clearly insufficient ability of the adult heart to regenerate after ischemic injury, there is a great opportunity to identify biological mechanisms, substances, and factors that enhance this process. Hence, innovative therapeutic management of heart failure following infarction requires a paradigm shift in pharmacotherapy. Spurred by tremendous progress in the field of stem cell and cardiac biology, several attractive approaches for regeneration of lost cardiomyocytes and supporting vasculature have emerged. Research in this area focuses on restoring the hearts' original function via proliferation and differentiation of cardiac progenitor cells, proliferation of pre-existing cardiomyocytes, and reprogramming of cardiac fibroblasts. In this review, we outline these principal strategies, putative biological targets or signaling pathways and chemical agents, with a focus on small molecules, to achieve therapeutic heart regeneration. We also point out the many remaining questions and challenges, particularly for translating in vitro discoveries to in vivo application.

  3. Guided Bone Regeneration with Novel Bioabsorbable Membranes (United States)

    Koyama, Yoshihisa; Kikuchi, Masanori; Yamada, Takeki; Kanaya, Tomohiro; Matsumoto, Hiroko N.; Takakuda, Kazuo; Miyairi, Hiroo; Tanaka, Junzo

    Guided Bone Regeneration (GBR) is a method for bone tissue regeneration. In this method, membranes are used to cover bone defects and to block the invasion of the surrounding soft tissues. It would provide sufficient time for the osteogenic cells from bone marrow to proliferate and form new bony tissues. In spite of the potential usefulness of this method, no appropriate materials for the GBR membrane have been developed. Here we design the ideal mechanical properties of the GBR membranes and created novel materials, which is the composite of β-tricalcium phosphate and block copolymer of L-lactide, glycolide and ɛ-caplolactone. In the animal experiments with the use of the trial products, we observed significant enhancement in the bone regeneration and proved the effectiveness of the materials.

  4. Skeletal muscle regeneration in cancer cachexia. (United States)

    Bossola, Maurizio; Marzetti, Emanuele; Rosa, Fausto; Pacelli, Fabio


    Muscle wasting is the most important phenotypic and clinical feature of cancer cachexia, and the principal cause of impaired physical function, fatigue, and respiratory complications. Muscle loss has been attributed to a variable combination of reduced nutritional intake and an imbalance between anabolic and catabolic processes. It has been suggested that defective skeletal muscle regeneration may also contribute to muscle wasting in cancer patients. However, there is little in vitro or in vivo data available, in either animals or in humans, regarding skeletal muscle regeneration in cancer wasting. The aim of the present review is to define the role of skeletal muscle regeneration in the muscle wasting of cancer patients and to determine possible therapeutic implications.

  5. [Regeneration of the gastric and intestinal mucosas]. (United States)

    Castrup, H J


    The physiological cell renewal of gastrointestinal mucosa is regulated in man as in animal through certain mechanisms with measurable kinetic data. Pathologic mucosal alterations, metabolic disorders, pharmacological agents etc. clearly affect the regenerative processes of the gastrointestinal epithelium. Gastrin and pentagastrin stimulate the growth not only of the parietal cells, but also of the superficial epithelium of the gastric mucosa, whereas secretin does not change cell growth. Glucocorticoid steroids inhibit epithelial regeneration in all parts of the gastrointestinal tract. 5-fluorouracil has a similar effect but acts at a different site in the regeneration cycle. Epithelial cell proliferation of the gastric and intestinal mucosa is likewise inhibited in an uremic condition. In inflammatory changes in the human gastric mucosa epithelial cell hyperproliferation relative to the severity of gastritis and anomalous proliferation within regions of dysplasia can be demonstrated. Foveolary hyperplasia in Ménétrier's disease occurs on the basis of excessive hyperproliferation with displacement of regeneration zones.

  6. [Regeneration and fibrosis of corneal tissues]. (United States)

    Simirskiĭ, V N


    In this review, the features of the regeneration of corneal tissue and its disorders leading to the development of fibrosis are considered. The data on the presence of stem (clonogenic) cell pool in the corneal tissues (epithelium, endothelium, stroma) are given; these cells can serve as a source for regeneration of the tissues at injury or various diseases. The main steps of regeneration of corneal tissues and their disorders that lead to outstripping proliferation of myofibroblasts and secretion of extracellular matrix in the wound area and eventually cause the formation of connective tissue scar and corneal opacity are considered. Particular attention is given to the successes of translational medicine in the treatment of corneal tissue fibrosis. The methods of cell therapy aimed at the restoration of stem cell pool of corneal tissues are the most promising. Gene therapy provides more opportunities; one of its main objectives is the suppression of the myofibroblast proliferation responsible for the development of fibrosis.

  7. Heat engine regenerators: Research status and needs

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, R.A.


    The rapidly oscillating, variable density flows of regenerative heat engines provide a class of poorly understood unsteady flow and heat transfer problems. These problems are not currently amenable to direct experimental resolution. Experiences in engine development and test programs and efforts to develop analysis tools point to the regenerator as a key area of insufficient understanding. Focusing on flow and heat transfer in regenerators, this report discusses similarity parameters for the flows and reviews the experimental data currently available for Stirling analysis. Then a number of experimental results are presented from recent fundamental fluid mechanical and thermal investigations that shed additional light on the functioning of heat engine regenerators. Suggestions are made for approaches for further measurement and analysis efforts.

  8. Microwave-Regenerated Diesel Exhaust Particulate Filter

    Energy Technology Data Exchange (ETDEWEB)

    Nixdorf, Richard D. (Industrial Ceramic Solution, LLC); Green, Johney Boyd; Story, John M.; Wagner, Robert M. (Oak Ridge National Laboratory)


    Development of a microwave-regenerated particulate filter system has evolved from bench scale work to actual diesel engine experimentation. The filter system was initially evaluated on a stationary mounted 1.2-L diesel engine and was able to remove a significant amount of carbon particles from the exhaust. The ability of the microwave energy to regenerate or clean the filter was also demonstrated on this engine under idle conditions. Based on the 1.2-L experiments, improvements to the filter design and materials were implemented and the system was re-evaluated on a vehicle equipped with a 7.3-L diesel engine. The 7.3-L engine was selected to achieve heavy filter loading in a relatively short period of time. The purpose of these experiments was to evaluate filter-loading capacity, power requirements for regeneration, and filter regeneration efficiency. A more detailed evaluation of the filter was performed on a stationary mounted 1.9-L diesel engine. The effect of exhaust flow rate, loading, transients, and regeneration on filter efficiency was evaluated with this setup. In addition, gaseous exhaust emissions were investigated with and without an oxidation catalyst on the filter cartridge during loading and regeneration. (SAE Paper SAE-2001-01-0903 © 2001 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

  9. Template Route to Chemically Engineering Cavities at Nanoscale: A Case Study of Zn(OH2 Template

    Directory of Open Access Journals (Sweden)

    Wu Junshu


    Full Text Available Abstract A size-controlled Zn(OH2 template is used as a case study to explain the chemical strategy that can be executed to chemically engineering various nanoscale cavities. Zn(OH2 octahedron with 8 vertices and 14 edges is fabricated via a low temperature solution route. The size can be tuned from 1 to 30 μm by changing the reaction conditions. Two methods can be selected for the hollow process without loss of the original shape of Zn(OH2 template. Ion-replacement reaction is suitable for fabrication of hollow sulfides based on the solubility difference between Zn(OH2 and products. Controlled chemical deposition is utilized to coat an oxide layer on the surface of Zn(OH2 template. The abundant hydroxyl groups on Zn(OH2 afford strong coordination ability with cations and help to the coating of a shell layer. The rudimental Zn(OH2 core is eliminated with ammonia solution. In addition, ZnO-based heterostructures possessing better chemical or physical properties can also be prepared via this unique templating process. Room-temperature photoluminescence spectra of the heterostructures and hollow structures are also shown to study their optical properties.


    NARCIS (Netherlands)



    The template polymerization of N-vinylimidazole (VIm) along poly(methacrylic acid) (PMAA) in water at 50-degrees-C with 2,2'-azobis(2-amidinopropane).2HCl (AAP) as initiator was studied by using variable initiator and monomer concentrations at constant [PMAA]/[VIm]0. From the order in [VIm] it was c

  11. Carbon as amorphous shell and interstitial dopant in mesoporous rutile TiO2: Bio-template assisted sol-gel synthesis and photocatalytic activity (United States)

    Mohamed, Mohamad Azuwa; Wan Salleh, Wan Norharyati; Jaafar, Juhana; Rosmi, Mohamad Saufi; Mohd. Hir, Zul Adlan; Abd Mutalib, Muhazri; Ismail, Ahmad Fauzi; Tanemura, Masaki


    Regenerated cellulose membrane was used as bio-template nanoreactor for the formation of rutile TiO2 mesoporous, as well as in-situ carbon dopant in acidified sol-gel system. The effects of calcination temperature on the physicochemical characteristic of core-shell nanostructured of bio-templated C-doped mesoporous TiO2 are highlighted in this study. By varying the calcination temperature, the thickness of the carbon shell coating on TiO2, crystallinity, surface area, and optical properties could be tuned as confirmed by HRTEM, nitrogen adsorption/desorption measurement, XRD and UV-vis-NIR spectroscopy. The results suggested that increment in the calcination temperature would lead to the band gap narrowing from 2.95 to 2.80 eV and the thickness of carbon shell increased from 0.40 to 1.20 nm. The x-ray photoelectron spectroscopy showed that the visible light absorption capability was mainly due to the incorporation of carbon dopant at interstitial position in the TiO2 to form Osbnd Tisbnd C or Tisbnd Osbnd C bond. In addition, the formation of the carbon core-shell nanostructured was due to carbonaceous layer grafted onto the surface of TiO2 via Tisbnd Osbnd C and Tisbnd OCO bonds. The result indicated that bio-templated C-doped core-shell mesoporous TiO2 prepared at 300 °C exhibited the highest photocatalytic activity. It is worthy to note that, the calcination temperature provided a huge impact towards improving the physicochemical and photocatalytic properties of the prepared bio-templated C-doped core-shell mesoporous TiO2.

  12. Hydride heat pump with heat regenerator (United States)

    Jones, Jack A. (Inventor)


    A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  13. Stem Cells for Bone Regeneration: From Cell-Based Therapies to Decellularised Engineered Extracellular Matrices (United States)

    Fisher, James N.; Peretti, Giuseppe M.; Scotti, Celeste


    Currently, autologous bone grafting represents the clinical gold standard in orthopaedic surgery. In certain cases, however, alternative techniques are required. The clinical utility of stem and stromal cells has been demonstrated for the repair and regeneration of craniomaxillofacial and long bone defects although clinical adoption of bone tissue engineering protocols has been very limited. Initial tissue engineering studies focused on the bone marrow as a source of cells for bone regeneration, and while a number of promising results continue to emerge, limitations to this technique have prompted the exploration of alternative cell sources, including adipose and muscle tissue. In this review paper we discuss the advantages and disadvantages of cell sources with a focus on adipose tissue and the bone marrow. Additionally, we highlight the relatively recent paradigm of developmental engineering, which promotes the recapitulation of naturally occurring developmental processes to allow the implant to optimally respond to endogenous cues. Finally we examine efforts to apply lessons from studies into different cell sources and developmental approaches to stimulate bone growth by use of decellularised hypertrophic cartilage templates. PMID:26997959

  14. Structure and functionalization of mesoporous bioceramics for bone tissue regeneration and local drug delivery. (United States)

    Vallet-Regí, María; Izquierdo-Barba, Isabel; Colilla, Montserrat


    This review article describes the importance of structure and functionalization in the performance of mesoporous silica bioceramics for bone tissue regeneration and local drug delivery purposes. Herein, we summarize the pivotal features of mesoporous bioactive glasses, also known as 'templated glasses' (TGs), which present chemical compositions similar to those of conventional bioactive sol-gel glasses and the added value of an ordered mesopore arrangement. An in-depth study concerning the possibility of tailoring the structural and textural characteristics of TGs at the nanometric scale and their influence on bioactive behaviour is discussed. The highly ordered mesoporous arrangement of cavities allows these materials to confine drugs to be subsequently released, acting as drug delivery devices. The functionalization of mesoporous silica walls has been revealed as the cornerstone in the performance of these materials as controlled release systems. The synergy between the improved bioactive behaviour and local sustained drug release capability of mesostructured materials makes them suitable to manufacture three-dimensional macroporous scaffolds for bone tissue engineering. Finally, this review tackles the possibility of covalently grafting different osteoinductive agents to the scaffold surface that act as attracting signals for bone cells to promote the bone regeneration process.

  15. [Use of diagnostic templates at stages of prosthetics treatment with implant-retained restorations]. (United States)

    Gvetadze, R Sh; Abramian, S V; Ivanov, A A; Nubarian, A P


    The comparative analysis of efficiency of various types of diagnostic templates for planning orthopedic treatment of 50 patients with partial or complete absence of teeth was performed. The patients were divided in 3 groups according to template manufacturing technique. All diagnostic templates made in accordance with clinical conditions allowed transfering digital data of the scheduled prosthetic construction for virtual implantation planning. Advantages and pitfalls of each template type are discussed.

  16. BMP signaling induces digit regeneration in neonatal mice. (United States)

    Yu, Ling; Han, Manjong; Yan, Mingquan; Lee, Eun-Chee; Lee, Jangwoo; Muneoka, Ken


    The regenerating digit tip of mice is a novel epimorphic response in mammals that is similar to fingertip regeneration in humans. Both display restricted regenerative capabilities that are amputation-level dependent. Using this endogenous regeneration model in neonatal mice, we have found that noggin treatment inhibits regeneration, thus suggesting a bone morphogenetic protein (BMP) requirement. Using non-regenerating amputation wounds, we show that BMP7 or BMP2 can induce a regenerative response. BMP-induced regeneration involves the formation of a mammalian digit blastema. Unlike the endogenous regeneration response that involves redifferentiation by direct ossification (evolved regeneration), the BMP-induced response involves endochondral ossification (redevelopment). Our evidence suggests that BMP treatment triggers a reprogramming event that re-initiates digit tip development at the amputation wound. These studies demonstrate for the first time that the postnatal mammalian digit has latent regenerative capabilities that can be induced by growth factor treatment.

  17. Sustainable Regeneration of Nanoparticle Enhanced Activated Carbon in Water (United States)

    The regeneration and reuse of exhausted granular activated carbon (GAC) is an appropriate method for lowering operational and environmental costs. Advanced oxidation is a promising environmental friendly technique for GAC regeneration. The main objective of this research was to ...

  18. The Application of TDZ in Enhancing Regeneration of Transgenic Plants

    Institute of Scientific and Technical Information of China (English)

    H.Y. Jia; B. Zhao; X.D. Wang


    @@ At present, transgenic plants are globally grown. Availability of a reliable regeneration system predominantly from a single transformed cell is the prerequisites for gene transfer, but regeneration is still a key problem (Wenzel, 2006).

  19. Improved modelling of a parallel plate active magnetic regenerator

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Tušek, J.; Nielsen, Kaspar Kirstein;


    flow maldistribution in the regenerator. This paper studies the effects of these loss mechanisms and compares theoretical results with experimental results obtained on an experimental AMR device. Three parallel plate regenerators were tested, each having different demagnetizing field characteristics...

  20. Why would firms engage in urban regeneration projects?

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig; Jensen, Jesper Ole

    Urban regeneration that combines integrated and place-based approaches increasingly aims at including public-private partnerships and the active involvement of companies in neighbourhood revitalisation. This is expected to contribute to regeneration in various valuable and sustainable ways...

  1. HL7 template model and EN/ISO 13606 archetype object model - a comparison. (United States)

    Bointner, Karl; Duftschmid, Georg


    HL7 Templates and EN/ISO 13606 Archetypes are essential components for a semantically interoperable exchange of electronic health record (EHR) data. In this article the underlying models from which Templates and Archetypes are instantiated, namely the HL7 Template Model and the EN/ISO 13606 Archetype Object Model will be compared to identify discrepancies and analogies.

  2. External and semi-internal controls for PCR amplification of homologous sequences in mixed templates

    DEFF Research Database (Denmark)

    Kalle, Elena; Gulevich, Alexander; Rensing, Christopher Günther T


    In a mixed template, the presence of homologous target DNA sequences creates environments that almost inevitably give rise to artifacts and biases during PCR. Heteroduplexes, chimeras, and skewed template-to-product ratios are the exclusive attributes of mixed template PCR and never occur in a si...

  3. Multi-template synthesis of hierarchically porous carbon spheres with potential application in supercapacitors

    NARCIS (Netherlands)

    Zhou, Weizheng; Lin, Zhixing; Tong, Gangsheng; Stoyanov, Simeon D.; Yan, Deyue; Mai, Yiyong; Zhu, Xinyuan


    A new and simple multi-template approach towards hierarchical porous carbon (HPC) materials was reported. HPC spheres were prepared by using hierarchical silica capsules (HSCs) as the hard template and triblock copolymer Pluronic P123 as the soft template. Three types of pores were tunably construct

  4. Template polymerization of N-vinylimidazole along poly(methacrylic acid) in water

    NARCIS (Netherlands)

    Grampel, Hendrik Theodorus van de


    Template polymerisaties zijn polymerisaties waarbij radicalen gedurende het grootste gedeelte van hun bestaan langs het template polymeer groeien. In het algemeen kan de template invloed hebben op de polymerisatiesnelheid, als ook op het molecuulgewicht en de tacticiteit van het bijgevormde polymeer

  5. Detecting lung cancer symptoms with analogic CNN algorithms based on a constrained diffusion template

    Energy Technology Data Exchange (ETDEWEB)

    Hirakawa, Satoshi; Nishio, Yoshifumi; Ushida, Akio; Ueno, Junji; Kasem, I.; Nishitani, Hiromu [Tokushima Univ. (Japan); Rekeczky, C.; Roska, T.


    In this article, a new type of diffusion template and an analogic CNN algorithm using this diffusion template for detecting some lung cancer symptoms in X-ray films are proposed. The performance of the diffusion template is investigated and our CNN algorithm is verified to detect some key lung cancer symptoms, successfully. (author)

  6. Comparison of Engineered Peptide-Glycosaminoglycan Microfibrous Hybrid Scaffolds for Potential Applications in Cartilage Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Steven M. Romanelli


    Full Text Available Advances in tissue engineering have enabled the ability to design and fabricate biomaterials at the nanoscale that can actively mimic the natural cellular environment of host tissue. Of all tissues, cartilage remains difficult to regenerate due to its avascular nature. Herein we have developed two new hybrid polypeptide-glycosaminoglycan microfibrous scaffold constructs and compared their abilities to stimulate cell adhesion, proliferation, sulfated proteoglycan synthesis and soluble collagen synthesis when seeded with chondrocytes. Both constructs were designed utilizing self-assembled Fmoc-protected valyl cetylamide nanofibrous templates. The peptide components of the constructs were varied. For Construct I a short segment of dentin sialophosphoprotein followed by Type I collagen were attached to the templates using the layer-by-layer approach. For Construct II, a short peptide segment derived from the integrin subunit of Type II collagen binding protein expressed by chondrocytes was attached to the templates followed by Type II collagen. To both constructs, we then attached the natural polymer N-acetyl glucosamine, chitosan. Subsequently, the glycosaminoglycan chondroitin sulfate was then attached as the final layer. The scaffolds were characterized by Fourier transform infrared spectroscopy (FT-IR, differential scanning calorimetry (DSC, atomic force microscopy and scanning electron microscopy. In vitro culture studies were carried out in the presence of chondrocyte cells for both scaffolds and growth morphology was determined through optical microscopy and scanning electron microscopy taken at different magnifications at various days of culture. Cell proliferation studies indicated that while both constructs were biocompatible and supported the growth and adhesion of chondrocytes, Construct II stimulated cell adhesion at higher rates and resulted in the formation of three dimensional cell-scaffold matrices within 24 h. Proteoglycan

  7. Advanced regenerator testing in the Raytheon dual-use cryocoolerr

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T. J. [Raytheon Space and Airborne Systems 2000 E. El Segundo Blvd., El Segundo, CA 90245 (United States)


    Significant progress has been made on the Raytheon low cost space cryocooler called the Dual-Use Cryocooler (DUC). Most notably, the DUC has been integrated and tested with an advanced regenerator. The advanced regenerator is a drop-in replacement for stainless steel screens and has shown significant thermodynamic performance improvements. This paper will compare the performance of two different regenerators and explain the benefits of the advanced regenerator.

  8. A regulatory program for excretory system regeneration in planarians


    Scimone, M Lucila; Srivastava, Mansi; Bell, George W.; Reddien, Peter W.


    Planarians can regenerate any missing body part, requiring mechanisms for the production of organ systems in the adult, including their prominent tubule-based filtration excretory system called protonephridia. Here, we identify a set of genes, Six1/2-2, POU2/3, hunchback, Eya and Sall, that encode transcription regulatory proteins that are required for planarian protonephridia regeneration. During regeneration, planarian stem cells are induced to form a cell population in regeneration blastem...

  9. Effect of cell-seeded hydroxyapatite scaffolds on rabbit radius bone regeneration. (United States)

    Rathbone, C R; Guda, T; Singleton, B M; Oh, D S; Appleford, M R; Ong, J L; Wenke, J C


    Highly porous hydroxyapatite (HA) scaffolds were developed as bone graft substitutes using a template coating process, characterized, and seeded with bone marrow-derived mesenchymal stem cells (BMSCs). To test the hypothesis that cell-seeded HA scaffolds improve bone regeneration, HA scaffolds without cell seeding (HA-empty), HA scaffolds with 1.5 × 10(4) BMSCs (HA-low), and HA scaffolds with 1.5 × 10(6) BMSCs (HA-high) were implanted in a 10-mm rabbit radius segmental defect model for 4 and 8 weeks. Three different fluorochromes were administered at 2, 4, and 6 weeks after implantation to identify differences in temporal bone growth patterns. It was observed from fluorescence histomorphometry analyses that an increased rate of bone infiltration occurred from 0 to 2 weeks (p < 0.05) of implantation for the HA-high group (2.9 ± 0.5 mm) as compared with HA-empty (1.8 ± 0.8 mm) and HA-low (1.3 ± 0.2 mm) groups. No significant differences in bone formation within the scaffold or callus formation was observed between all groups after 4 weeks, with a significant increase in bone regenerated for all groups from 4 to 8 weeks (28.4% across groups). Although there was no difference in bone formation within scaffolds, callus formation was significantly higher in HA-empty scaffolds (100.9 ± 14.1 mm(3) ) when compared with HA-low (57.8 ± 7.3 mm(3) ; p ≤ 0.003) and HA-high (69.2 ± 10.4 mm(3) ; p ≤ 0.02) after 8 weeks. These data highlight the need for a better understanding of the parameters critical to the success of cell-seeded HA scaffolds for bone regeneration.

  10. Distinct Wnt signaling pathways have opposing roles in appendage regeneration. (United States)

    Stoick-Cooper, Cristi L; Weidinger, Gilbert; Riehle, Kimberly J; Hubbert, Charlotte; Major, Michael B; Fausto, Nelson; Moon, Randall T


    In contrast to mammals, lower vertebrates have a remarkable capacity to regenerate complex structures damaged by injury or disease. This process, termed epimorphic regeneration, involves progenitor cells created through the reprogramming of differentiated cells or through the activation of resident stem cells. Wnt/beta-catenin signaling regulates progenitor cell fate and proliferation during embryonic development and stem cell function in adults, but its functional involvement in epimorphic regeneration has not been addressed. Using transgenic fish lines, we show that Wnt/beta-catenin signaling is activated in the regenerating zebrafish tail fin and is required for formation and subsequent proliferation of the progenitor cells of the blastema. Wnt/beta-catenin signaling appears to act upstream of FGF signaling, which has recently been found to be essential for fin regeneration. Intriguingly, increased Wnt/beta-catenin signaling is sufficient to augment regeneration, as tail fins regenerate faster in fish heterozygous for a loss-of-function mutation in axin1, a negative regulator of the pathway. Likewise, activation of Wnt/beta-catenin signaling by overexpression of wnt8 increases proliferation of progenitor cells in the regenerating fin. By contrast, overexpression of wnt5b (pipetail) reduces expression of Wnt/beta-catenin target genes, impairs proliferation of progenitors and inhibits fin regeneration. Importantly, fin regeneration is accelerated in wnt5b mutant fish. These data suggest that Wnt/beta-catenin signaling promotes regeneration, whereas a distinct pathway activated by wnt5b acts in a negative-feedback loop to limit regeneration.

  11. Human stem cells and articular cartilage regeneration. (United States)

    Inui, Atsuyuki; Iwakura, Takashi; Reddi, A Hari


    The regeneration of articular cartilage damaged due to trauma and posttraumatic osteoarthritis is an unmet medical need. Current approaches to regeneration and tissue engineering of articular cartilage include the use of chondrocytes, stem cells, scaffolds and signals, including morphogens and growth factors. Stem cells, as a source of cells for articular cartilage regeneration, are a critical factor for articular cartilage regeneration. This is because articular cartilage tissue has a low cell turnover and does not heal spontaneously. Adult stem cells have been isolated from various tissues, such as bone marrow, adipose, synovial tissue, muscle and periosteum. Signals of the transforming growth factor beta superfamily play critical roles in chondrogenesis. However, adult stem cells derived from various tissues tend to differ in their chondrogenic potential. Pluripotent stem cells have unlimited proliferative capacity compared to adult stem cells. Chondrogenesis from embryonic stem (ES) cells has been studied for more than a decade. However, establishment of ES cells requires embryos and leads to ethical issues for clinical applications. Induced pluripotent stem (iPS) cells are generated by cellular reprogramming of adult cells by transcription factors. Although iPS cells have chondrogenic potential, optimization, generation and differentiation toward articular chondrocytes are currently under intense investigation.

  12. Demagnetizing fields in active magnetic regenerators

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Bahl, Christian R.H.; Smith, Anders


    A magnetic material in an externally applied magnetic field will in general experience a spatially varying internal magnetic field due to demagnetizing effects. When the performance of active magnetic regenerators (AMRs) is evaluated using numerical models the internal field is often assumed to b...

  13. Bone regeneration: current concepts and future directions

    Directory of Open Access Journals (Sweden)

    McGonagle Dennis


    Full Text Available Abstract Bone regeneration is a complex, well-orchestrated physiological process of bone formation, which can be seen during normal fracture healing, and is involved in continuous remodelling throughout adult life. However, there are complex clinical conditions in which bone regeneration is required in large quantity, such as for skeletal reconstruction of large bone defects created by trauma, infection, tumour resection and skeletal abnormalities, or cases in which the regenerative process is compromised, including avascular necrosis, atrophic non-unions and osteoporosis. Currently, there is a plethora of different strategies to augment the impaired or 'insufficient' bone-regeneration process, including the 'gold standard' autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. Improved 'local' strategies in terms of tissue engineering and gene therapy, or even 'systemic' enhancement of bone repair, are under intense investigation, in an effort to overcome the limitations of the current methods, to produce bone-graft substitutes with biomechanical properties that are as identical to normal bone as possible, to accelerate the overall regeneration process, or even to address systemic conditions, such as skeletal disorders and osteoporosis.

  14. Cellular and genetic approaches to myocardial regeneration

    NARCIS (Netherlands)

    Tuyn, John van


    Injection of (stem) cells into the damaged heart has a positive effect on cardiac function. In this thesis two strategies for improving myocardial regeneration over classical cell therapy were investigated. The first is to induce cardiomyogenic differentiation by genetically engineering cells to ex

  15. Immunobiology of Facial Nerve Repair and Regeneration

    Institute of Scientific and Technical Information of China (English)

    QUAN Shi-ming; GAO Zhi-qiang


    Immunobiological study is a key to revealing the important basis of facial nerve repair and regeneration for both research and development of clinic treatments. The microenvironmental changes around an injuried facial motoneuron, i.e., the aggregation and expression of various types of immune cells and molecules in a dynamic equilibrium, impenetrate from the start to the end of the repair of an injured facial nerve. The concept of "immune microenvironment for facial nerve repair and regeneration", mainly concerns with the dynamic exchange between expression and regulation networks and a variaty of immune cells and immune molecules in the process of facial nerve repair and regeneration for the maintenance of a immune microenvironment favorable for nerve repair.Investigation on microglial activation and recruitment, T cell behavior, cytokine networks, and immunological cellular and molecular signaling pathways in facial nerve repair and regeneration are the current hot spots in the research on immunobiology of facial nerve injury. The current paper provides a comprehensive review of the above mentioned issues. Research of these issues will eventually make immunological interventions practicable treatments for facial nerve injury in the clinic.

  16. Stem cells to regenerate the newborn brain

    NARCIS (Netherlands)

    van Velthoven, C.T.J.


    Perinatal hypoxia-ischemia (HI) is a frequent cause of perinatal morbidity and mortality with limited therapeutic options. In this thesis we investigate whether mesenchymal stem cells (MSC) regenerate the neonatal brain after HI injury. We show that transplantation of MSC after neonatal brain injury

  17. Calcium phosphate coatings for bone regeneration

    NARCIS (Netherlands)

    Yang, Liang


    As a novel approach to repair and regenerate damaged and degraded bone tissue, tissue engineering has recorded tremendous growth for the last thirty years. This is an emerging interdisciplinary field applying the principles of biology and engineering to the development of viable substitutes that res

  18. Kidney regeneration and repair after transplantation

    NARCIS (Netherlands)

    M. Franquesa (Marcella); M. Flaquer (Maria); J.M. Cruzado; J. Grinyo (Josep)


    textabstractPURPOSE OF REVIEW: To briefly show which are the mechanisms and cell types involved in kidney regeneration and describe some of the therapies currently under study in regenerative medicine for kidney transplantation. RECENT FINDINGS: The kidney contains cell progenitors that under specif

  19. Planning and Implementation of Urban Regeneration

    DEFF Research Database (Denmark)

    Aunsborg, Christian; Sørensen, Michael Tophøj


    the regeneration challenge became an issue in the professional debate. The urban, economic and spatial problematics rising from structural development trends of society were subject to a committee work from 1999 through 2001. The work resulted in a number of recommendations comprising i.a. suggestions concerning...

  20. Thymus: the next (re)generation. (United States)

    Chaudhry, Mohammed S; Velardi, Enrico; Dudakov, Jarrod A; van den Brink, Marcel R M


    As the primary site of T-cell development, the thymus plays a key role in the generation of a strong yet self-tolerant adaptive immune response, essential in the face of the potential threat from pathogens or neoplasia. As the importance of the role of the thymus has grown, so too has the understanding that it is extremely sensitive to both acute and chronic injury. The thymus undergoes rapid degeneration following a range of toxic insults, and also involutes as part of the aging process, albeit at a faster rate than many other tissues. The thymus is, however, capable of regenerating, restoring its function to a degree. Potential mechanisms for this endogenous thymic regeneration include keratinocyte growth factor (KGF) signaling, and a more recently described pathway in which innate lymphoid cells produce interleukin-22 (IL-22) in response to loss of double positive thymocytes and upregulation of IL-23 by dendritic cells. Endogenous repair is unable to fully restore the thymus, particularly in the aged population, and this paves the way toward the need for exogenous strategies to help regenerate or even replace thymic function. Therapies currently in clinical trials include KGF, use of the cytokines IL-7 and IL-22, and hormonal modulation including growth hormone administration and sex steroid inhibition. Further novel strategies are emerging in the preclinical setting, including the use of precursor T cells and thymus bioengineering. The use of such strategies offers hope that for many patients, the next regeneration of their thymus is a step closer.

  1. Fingernails Yield Clues to Limb Regeneration (United States)

    ... Diseases has uncovered chemical signals that drive the regeneration of lost digit tips in mice. The findings, published in the journal Nature, could eventually lead to the development of novel treatments for amputees. While salamanders and newts are well known for their ability ...

  2. Reparative inflammation takes charge of tissue regeneration

    NARCIS (Netherlands)

    Karin, Michael; Clevers, Hans


    Inflammation underlies many chronic and degenerative diseases, but it also mitigates infections, clears damaged cells and initiates tissue repair. Many of the mechanisms that link inflammation to damage repair and regeneration in mammals are conserved in lower organisms, indicating that it is an evo

  3. Growth factor interactions in bone regeneration

    NARCIS (Netherlands)

    Kempen, D.H.R.; Creemers, L.B.; Alblas, J.; Lu, L.; Verbout, A.J.; Yaszemski, M.J.; Dhert, W.J.A.


    Growth factor interactions in bone regeneration. Diederik H R Kempen, Laura B Creemers, Jacqueline Alblas, Lichun Lu, Abraham J Verbout, Michael J Yaszemski and Wouter J A Dhert 1 Department of Orthopedics, University Medical Center , Utrecht, The Netherlands . AbstractBuy the PDF Pubmed abstract Ge

  4. Human Stem Cells and Articular Cartilage Regeneration

    Directory of Open Access Journals (Sweden)

    A. Hari Reddi


    Full Text Available  The regeneration of articular cartilage damaged due to trauma and posttraumatic osteoarthritis is an unmet medical need. Current approaches to regeneration and tissue engineering of articular cartilage include the use of chondrocytes, stem cells, scaffolds and signals, including morphogens and growth factors. Stem cells, as a source of cells for articular cartilage regeneration, are a critical factor for articular cartilage regeneration. This is because articular cartilage tissue has a low cell turnover and does not heal spontaneously. Adult stem cells have been isolated from various tissues, such as bone marrow, adipose, synovial tissue, muscle and periosteum. Signals of the transforming growth factor beta superfamily play critical roles in chondrogenesis. However, adult stem cells derived from various tissues tend to differ in their chondrogenic potential. Pluripotent stem cells have unlimited proliferative capacity compared to adult stem cells. Chondrogenesis from embryonic stem (ES cells has been studied for more than a decade. However, establishment of ES cells requires embryos and leads to ethical issues for clinical applications. Induced pluripotent stem (iPS cells are generated by cellular reprogramming of adult cells by transcription factors. Although iPS cells have chondrogenic potential, optimization, generation and differentiation toward articular chondrocytes are currently under intense investigation.

  5. Bioinorganics: synthetic growth factors for bone regeneration

    NARCIS (Netherlands)

    Tahmasebi Birgani, Z.


    Bone tissue is naturally able to regenerate when damaged. However, in many large defects caused by fractures due to aging or osteoporosis, trauma, tumor removal, etc., the natural regenerative ability of bone is not sufficient to fully heal the defect. In such cases, a graft is required to support t

  6. Heterogeneous scaffold designs for selective neural regeneration

    NARCIS (Netherlands)

    Wieringa, P.A.


    Over the past 5 decades, there has been a drive to apply technology to enhance neural regeneration in order to improve patient recovery after disease or injury. This has evolved into the field of Neural Engineering, with the aim to understand, control and exploit the development and function of neur

  7. Economic analysis of replacement regeneration and coppice regeneration in eucalyptus stands under risk conditions

    Directory of Open Access Journals (Sweden)

    Isabel Carolina de Lima Guedes


    Full Text Available Projects are by their very nature subject to conditions of uncertainty that obstruct the decision-making process. Uncertainties involving forestry projects are even greater, as they are combined with time of return on capital invested, being medium to long term. For successful forest planning, it is necessary to quantify uncertainties by converting them into risks. The decision on whether to adopt replacement regeneration or coppice regeneration in a forest stand is influenced by several factors, which include land availability for new forest crops, changes in project end use, oscillations in demand and technological advancement. This study analyzed the economic feasibility of replacement regeneration and coppice regeneration of eucalyptus stands, under deterministic and under risk conditions. Information was gathered about costs and revenues for charcoal production in order to structure the cash flow used in the economic analysis, adopting the Net Present Value method (VPL. Risk assessment was based on simulations running the Monte Carlo method. Results led to the following conclusions: replacement regeneration is economically viable, even if the future stand has the same productivity as the original stand; coppice regeneration is an economically viable option even if productivity is a mere 70% of the original stand (high-tree planted stand, the best risk-return ratio option is restocking the stand (replacement regeneration by one that is 20% more productive; the probabilistic analysis running the Monte Carlo method revealed that invariably there is economic viability for the various replacement and coppice regeneration options being studied, minimizing uncertainties and consequently increasing confidence in decision-making.

  8. Modeling of active magnetic regenerators and experimental investigation of passive regenerators with oscillating flow

    DEFF Research Database (Denmark)

    Lei, Tian

    loss mechanisms and optimizing AMRs. The impacts of the heat loss through the regenerator housing and the dead volume are also quantified. A multiparameter optimization reveals the optimal dimensions and operating parameters for different regenerator geometries. In order to evaluate different...... and deduced indicators, including the pressure drop, friction factor, effectiveness, heating power and overall Nusselt number. Finally, based on the research in this thesis, the perspectives and some suggestions for the future work are given....

  9. Using absorbable collagen membranes for guided tissue regeneration, guided bone regeneration, and to treat gingival recession. (United States)

    Wang, H L; Carroll, W J


    This article reviews the role of barrier membranes in guided tissue regeneration (GTR) and guided bone regeneration (GBR), including the advantages of using absorbable barrier membranes in GTR and GBR and the unique properties of collagen membranes. The indications and contraindications for using collagen membranes for these procedures are examined, and successful cases are presented. Finally, the role of collagen membranes in the future of regenerative therapy is considered.

  10. Tailoring the porosity of hierarchical zeolites by carbon-templating

    DEFF Research Database (Denmark)

    Zhu, Kake; Egeblad, Kresten; Christensen, Claus H.


    We report the synthesis and characterization of a series of hierarchical porous zeolite single crystal materials with a range of porosities made available by carbon-templating using differently-sized carbon particles as templates for the additional non-micropore porosity. The materials were...... prepared by adsorption of the required zeolite synthesis gel components onto various commercially available carbon black powders followed by crystallization of the zeolite crystals in the presence of the inert carbon matrix and subsequent removal of the carbon particles embedded in the zeolite crystals...... by combustion. It is shown that the additional porosity of the hierarchical zeolites can be tailored by encapsulation of the differently-sized carbon particles during crystallization....

  11. Computer-aided modeling framework – a generic modeling template

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    This work focuses on the development of a computer-aided modeling framework. The framework is a knowledge-based system that is built on a generic modeling language and structured on workflows for different modeling tasks. The overall objective is to support model developers and users to generate...... and test models systematically, efficiently and reliably. In this way, development of products and processes can be made faster, cheaper and more efficient. In this contribution, as part of the framework, a generic modeling template for the systematic derivation of problem specific models is presented....... The application of the modeling template is highlighted with a case study related to the modeling of a catalytic membrane reactor coupling dehydrogenation of ethylbenzene with hydrogenation of nitrobenzene...

  12. Template fitting and the large-angle CMB anomalies

    CERN Document Server

    Land, K; Land, Kate; Magueijo, Joao


    We investigate two possible explanations for the large-angle anomalies in the Cosmic Microwave Background (CMB): an intrinsically anisotropic model and an inhomogeneous model. We take as an example of the former a Bianchi model (which leaves a spiral pattern in the sky) and of the latter a background model that already contains a non-linear long-wavelength plane wave (leaving a stripy pattern in the sky). We make use of an adaptation of the ``template'' formalism, previously designed to detect galactic foregrounds, to recognize these patterns and produce confidence levels for their detection. The ``corrected'' maps, from which these patterns have been removed, are free of anomalies, in particular their quadrupole and octupole are not planar and their intensities not low. We stress that although the ``template'' detections are not found to be statistically significant they do correct statistically significant anomalies.

  13. Supported lipid bilayers as templates to design manganese oxide nanoparticles

    Indian Academy of Sciences (India)

    J Maheshkumar; B Sreedhar; B U Nair; A Dhathathreyan


    This work reports on the preparation of nanoclusters of manganese oxide using biotemplating techniques. Supported lipid bilayers (SLBs) on quartz using cationic lipid [Dioctadecyldimethylammonium bromide (DOMA)] and mixed systems with neutral phospholipids dipalmitoyl phosphatidylcholine (DPPC) and dioleoyl phosphatidylcholine (DOPC) have been used as templates to synthesize these nanoparticles in a waterbased medium at room temperature. The Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) show manganese oxide nanostructures that are composed of crystals or small clusters in the size range of 20-50 nm in diameter. Small angle XRD showed that template removal through calcining process results in nanostructures of the manganese oxide in sizes from 30 to 50 nm. Using these organized assemblies it is possible to control the nano and mesoscopic morphologies of particles and both rod-like and spherical particles can be synthesized.

  14. Custom Fenestration Templates for Endovascular Repair of Juxtarenal Aortic Aneurysms (United States)

    Leotta, Daniel F.; Starnes, Benjamin W.


    Physician-modified endovascular grafts, with fenestrations added to accommodate major branch vessels, provide a means for endovascular treatment of abdominal aortic aneurysms that are adjacent to the renal arteries. Manual measurements of vessel origin locations from CT images, however, take time and can lead to errors in the positions of the fenestrations. To make the fenestration process faster and more accurate, we have developed a procedure to create custom templates that serve as patient-specific guides for graft fenestration. We use a 3D printer to create a clear rigid sleeve that replicates the patient’s aorta and includes holes placed precisely at the locations of the branch vessels. The sleeve is slipped over the graft, the locations of the openings are marked with a pen, and the fenestrations are created after removing the sleeve. Custom fenestration templates can potentially save procedural costs and make minimally-invasive aortic aneurysm repair available to more patients. PMID:25864045

  15. Highly tailorable thiol-ene based emulsion-templated monoliths

    DEFF Research Database (Denmark)

    Lafleur, J. P.; Kutter, J. P.


    The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off-stoichiometr......The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off......-stoichiometry thiolene chemistry. The method allows monolith synthesis and anchoring inside thiol-ene microchannels in a single step. Variations in the monomer stoichiometric ratios and/or amount of porogen used allow for the creation of extremely varied polymer morphologies, from foam-like materials to dense networks...

  16. Script identification from images using cluster-based templates (United States)

    Hochberg, J.G.; Kelly, P.M.; Thomas, T.R.


    A computer-implemented method identifies a script used to create a document. A set of training documents for each script to be identified is scanned into the computer to store a series of exemplary images representing each script. Pixels forming the exemplary images are electronically processed to define a set of textual symbols corresponding to the exemplary images. Each textual symbol is assigned to a cluster of textual symbols that most closely represents the textual symbol. The cluster of textual symbols is processed to form a representative electronic template for each cluster. A document having a script to be identified is scanned into the computer to form one or more document images representing the script to be identified. Pixels forming the document images are electronically processed to define a set of document textual symbols corresponding to the document images. The set of document textual symbols is compared to the electronic templates to identify the script. 17 figs.

  17. Chinese license plate character segmentation using multiscale template matching (United States)

    Tian, Jiangmin; Wang, Guoyou; Liu, Jianguo; Xia, Yuanchun


    Character segmentation (CS) plays an important role in automatic license plate recognition and has been studied for decades. A method using multiscale template matching is proposed to settle the problem of CS for Chinese license plates. It is carried out on a binary image integrated from maximally stable extremal region detection and Otsu thresholding. Afterward, a uniform harrow-shaped template with variable length is designed, by virtue of which a three-dimensional matching space is constructed for searching of candidate segmentations. These segmentations are detected at matches with local minimum responses. Finally, the vertical boundaries of each single character are located for subsequent recognition. Experiments on a data set including 2349 license plate images of different quality levels show that the proposed method can achieve a higher accuracy at comparable time cost and is robust to images in poor conditions.

  18. ProFIT Prolog with Features, Inheritance and Templates

    CERN Document Server

    Erbach, G


    ProFIT is an extension of Standard Prolog with Features, Inheritance and Templates. ProFIT allows the programmer or grammar developer to declare an inheritance hierarchy, features and templates. Sorted feature terms can be used in ProFIT programs together with Prolog terms to provide a clearer description language for linguistic structures. ProFIT compiles all sorted feature terms into a Prolog term representation, so that the built-in Prolog term unification can be used for the unification of sorted feature structures, and no special unification algorithm is needed. ProFIT programs are compiled into Prolog programs, so that no meta-interpreter is needed for their execution. ProFIT thus provides a direct step from grammars developed with sorted feature terms to Prolog programs usable for practical NLP systems.

  19. Template aging in eye movement-driven biometrics (United States)

    Komogortsev, Oleg V.; Holland, Corey D.; Karpov, Alex


    This paper presents a template aging study of eye movement biometrics, considering three distinct biometric techniques on multiple stimuli and eye tracking systems. Short-to-midterm aging effects are examined over two-weeks, on a highresolution eye tracking system, and seven-months, on a low-resolution eye tracking system. We find that, in all cases, aging effects are evident as early as two weeks after initial template collection, with an average 28% (±19%) increase in equal error rates and 34% (±12%) reduction in rank-1 identification rates. At seven months, we observe an average 18% (±8%) increase in equal error rates and 44% (±20%) reduction in rank-1 identification rates. The comparative results at two-weeks and seven-months suggests that there is little difference in aging effects between the two intervals; however, whether the rate of decay increases more drastically in the long-term remains to be seen.

  20. Template based parallel checkpointing in a massively parallel computer system (United States)

    Archer, Charles Jens; Inglett, Todd Alan


    A method and apparatus for a template based parallel checkpoint save for a massively parallel super computer system using a parallel variation of the rsync protocol, and network broadcast. In preferred embodiments, the checkpoint data for each node is compared to a template checkpoint file that resides in the storage and that was previously produced. Embodiments herein greatly decrease the amount of data that must be transmitted and stored for faster checkpointing and increased efficiency of the computer system. Embodiments are directed to a parallel computer system with nodes arranged in a cluster with a high speed interconnect that can perform broadcast communication. The checkpoint contains a set of actual small data blocks with their corresponding checksums from all nodes in the system. The data blocks may be compressed using conventional non-lossy data compression algorithms to further reduce the overall checkpoint size.

  1. Multi-biometric templates using fingerprint and voice (United States)

    Camlikaya, Eren; Kholmatov, Alisher; Yanikoglu, Berrin


    As biometrics gains popularity, there is an increasing concern about privacy and misuse of biometric data held in central repositories. Furthermore, biometric verification systems face challenges arising from noise and intra-class variations. To tackle both problems, a multimodal biometric verification system combining fingerprint and voice modalities is proposed. The system combines the two modalities at the template level, using multibiometric templates. The fusion of fingerprint and voice data successfully diminishes privacy concerns by hiding the minutiae points from the fingerprint, among the artificial points generated by the features obtained from the spoken utterance of the speaker. Equal error rates are observed to be under 2% for the system where 600 utterances from 30 people have been processed and fused with a database of 400 fingerprints from 200 individuals. Accuracy is increased compared to the previous results for voice verification over the same speaker database.

  2. Medical Image Retrieval Based on Multi-Layer Resampling Template

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-rui; YANG Yun-feng


    Medical image application in clinical diagnosis and treatment is becoming more and more widely, How to use a large number of images in the image management system and it is a very important issue how to assist doctors to analyze and diagnose. This paper studies the medical image retrieval based on multi-layer resampling template under the thought of the wavelet decomposition, the image retrieval method consists of two retrieval process which is coarse and fine retrieval. Coarse retrieval process is the medical image retrieval process based on the image contour features. Fine retrieval process is the medical image retrieval process based on multi-layer resampling template, a multi-layer sampling operator is employed to extract image resampling images each layer, then these resampling images are retrieved step by step to finish the process from coarse to fine retrieval.

  3. Statistical Hiding Fuzzy Commitment Scheme for Securing Biometric Templates

    Directory of Open Access Journals (Sweden)

    Alawi A. Al-Saggaf


    Full Text Available By considering the security flaws in cryptographic hash functions, any commitment scheme designed straight through hash function usage in general terms is insecure. In this paper, we develop a general fuzzy commitment scheme called an ordinary fuzzy commitment scheme (OFCS, in which many fuzzy commitment schemes with variety complexity assumptions is constructed. The scheme is provably statistical hiding (the advisory gets almost no statistically advantages about the secret message. The efficiency of our scheme offers different security assurance, and the trusted third party is not involved in the exchange of commitment.The characteristic of our scheme makes it useful for biometrics systems. If the biometrics template is compromised, then there is no way to use it directly again even in secure biometrics systems. This paper combines biometrics and OFCS to achieve biometric protection scheme using smart cards with renewability of protected biometrics template property.

  4. Dendrimer Templates for the Formation of Silver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LI Guo-ping; LUO Yun-jun; XU Hou-cai; TAN Hui-min


    In order to control the size and shape of Ag nanoparticles obtained by using poly(amidoamine) (PAMAM) dendrimer as template, the complexation between Ag+ ions and dendrimer studied extensively by UVVis spectroscopy and FTIR. After the Ag+/PAMAM demdrimer being reduced by direct chemical reduction,Ag (0) nanoparticles was formed, whose structure and characterization were studied by UV-Vis spectroscopy,transmission electron microscopy (TEM) and electron diffraction (ED) respectively. The results reveal that Ag nanoparticles is a kind of face center cubic crystal and its average size is 4.5 nm. The solubility and stability of the solution containing Ag nanoparticles also indicate that dendrimer is a good kind of template, as well as a protective agent.

  5. Proline-catalysed asymmetric ketol cyclizations: The template mechanism revisited

    Indian Academy of Sciences (India)

    R Malathi; D Rajagopal; Zoltan G Hajos; S Swaminathan


    A modified template mechanism based on modelling studies of energy minimised complexes is presented for the asymmetric proline-catalysed cyclization of triketones 1, 2 and 3 to the 2, 3-ketols 1a, 2a and 3a respectively. The template model involves a three-point contact as favoured in enzyme-substrate interactions. Our minimisation studies are in agreement with the divergent behaviour of the 6,5-, 6,6- and 6,7-bicyclic systems. They support the high 93.4% ee observed with the 6,5-bicyclic ketol and the lower 73% ee found with the 6,6-bicyclic ketol. The calculations also explain the lack of asymmetric induction with the 6,7-bicyclic system.

  6. A database of age-appropriate average MRI templates. (United States)

    Richards, John E; Sanchez, Carmen; Phillips-Meek, Michelle; Xie, Wanze


    This article summarizes a life-span neurodevelopmental MRI database. The study of neurostructural development or neurofunctional development has been hampered by the lack of age-appropriate MRI reference volumes. This causes misspecification of segmented data, irregular registrations, and the absence of appropriate stereotaxic volumes. We have created the "Neurodevelopmental MRI Database" that provides age-specific reference data from 2 weeks through 89 years of age. The data are presented in fine-grained ages (e.g., 3 months intervals through 1 year; 6 months intervals through 19.5 years; 5 year intervals from 20 through 89 years). The base component of the database at each age is an age-specific average MRI template. The average MRI templates are accompanied by segmented partial volume estimates for segmenting priors, and a common stereotaxic atlas for infant, pediatric, and adult participants. The database is available online (

  7. A clinical trial of Integra Template for diabetic foot ulcer treatment. (United States)

    Driver, Vickie R; Lavery, Lawrence A; Reyzelman, Alexander M; Dutra, Timothy G; Dove, Cyaandi R; Kotsis, Sandra V; Kim, Hyungjin Myra; Chung, Kevin C


    Individuals with diabetes mellitus are at an increased risk of developing a diabetic foot ulcer (DFU). This study evaluated the safety and efficacy of Integra Dermal Regeneration Template (IDRT) for the treatment of nonhealing DFUs. The Foot Ulcer New Dermal Replacement Study was a multicenter, randomized, controlled, parallel group clinical trial conducted under an Investigational Device Exemption. Thirty-two sites enrolled and randomized 307 subjects with at least one DFU. Consented patients were entered into the 14-day run-in phase where they were treated with the standard of care (0.9% sodium chloride gel) plus a secondary dressing and an offloading/protective device. Patients with less than 30% reepithelialization of the study ulcer after the run-in phase were randomized into the treatment phase. The subjects were randomized to the control treatment group (0.9% sodium chloride gel; n = 153) or the active treatment group (IDRT, n = 154). The treatment phase was 16 weeks or until confirmation of complete wound closure (100% reepithelialization of the wound surface), whichever occurred first. Following the treatment phase, all subjects were followed for 12 weeks. Complete DFU closure during the treatment phase was significantly greater with IDRT treatment (51%) than control treatment (32%; p = 0.001) at sixteen weeks. The median time to complete DFU closure was 43 days for IDRT subjects and 78 days for control subjects in wounds that healed. The rate of wound size reduction was 7.2% per week for IDRT subjects vs. 4.8% per week for control subjects (p = 0.012). For the treatment of chronic DFUs, IDRT treatment decreased the time to complete wound closure, increased the rate of wound closure, improved components of quality of life and had less adverse events compared with the standard of care treatment. IDRT could greatly enhance the treatment of nonhealing DFUs.

  8. The metal site as a template for the metalloprotein structure formation. (United States)

    Liu, Changlin; Xu, Huibi


    Achieving a thorough explanation of the behavior of metal sites in the formation of native metalloprotein structures is an exciting challenge in the biochemistry of metallobiomacromolecules. This study presents a personal insight into the subject. It is proposed that a metal center and its exogenous ligand compose a template. A template may impose a clear stereochemical preference on the loose peptide chains, and organize them into natural stereospecificity via the metal-ligand interaction, a long-range and strong interaction. Therefore, the stable peptide conformation induced by the template effect surrounding a template polyhedron could be called a template-mediated structural motif (TMSM).

  9. Home Automation : Smart home technology and template house design


    Zheng, Zeya


    In this thesis, home automation’s general knowledge, technology information and each component will be introduced to the reader in the first half of the whole thesis. In the second half, thesis includes the Home Automation template design and market competitiveness analysis. The author assumes that the reader is going to spend lots of money to have a smart home. In this situation, the author introduces the home automation to the reader at each component. So the reader in this thesis actu...

  10. A novel supramolecular organogel nanotubular template approach for conducting nanomaterials. (United States)

    Anilkumar, P; Jayakannan, M


    We report a unique supramolecular organogel template approach for conducting polyaniline nanomaterials. A novel organogel based on sulfonic acid dopant was designed and developed from renewable resource 3-pentadecyl phenol via ring-opening of 1,4-butane sultone. The amphiphilic dopant molecule formed thermo-reversible supramolecular organogel in highly polar solvents like alcohols. The self-assembled fibril network morphology of the gel was confirmed by scanning electron microscopy (SEM) and atomic force microscopy. Transmission electron microscopy (TEM) revealed that the inner part of the fibrous gel is nanotubular with the pore diameter of approximately 75 nm. The organogel nanotubular morphology was retained even in the presence of aniline+dopant complex, and the aniline monomers occupied the hydrophobic nanopockets provided by the amphiphilic dopant. The chemical oxidative polymerization of the dopant+aniline organogel template produced well-defined polyaniline nanofibers. The polymerization was carried out at various temperatures to establish the role of the physical state and stability of the organogel on the morphology. The sulfonic acid molecule acts both as self-assembled molecular template for the synthesis of polymer nanomaterial as well as anionic counterpart for stabilizing the positively charged conducting polymer chains. The gel template played a pivotal role in directing polyaniline chains to form nanofibers and also manipulating the number of other properties such as conductivity, solubility, percent crystallinity, and solid-state ordering, etc. Temperature-dependent electrical conductivity measurements revealed that the nanomaterials showed typical linear ohmic behavior and also followed the 3-D VRH model at elevated temperatures.

  11. An X-ray template assessment for distal radial fractures (United States)

    Lindeboom, R.; Oosterkamp, A. E.; Goslings, J. C.


    Background The current method for radiological measurements on plain X-rays of distal radius fractures is unreliable. We examined the reproducibility of a new X-ray assessment technique—where the uninjured side is used as a template for the injured side—compared to the conventional assessment technique. Methods X-rays of 30 patients with a unilateral distal radial fracture were included reflecting the prevalence of AO fracture types in clinical practice. Eight experienced observers assessed these X-rays on two separated occasions (2-month interval) using the traditional measurement technique and the template technique. Reproducibility of the X-ray assessments was quantified by intraclass correlations and weighted kappa coefficients. Results The reproducibility of the radial length measurement did not improve nor did the volar angulation measurement. However, marked improvement in reproducibility was observed for the radial inclination measurement, the kappa increased from 0.36 (95 % CI; 0.30–0.41) to 0.49 (95 % CI; 0.43–0.55) in the template technique. As a result, the classification of the reduction results (Lidström score) greatly improved. The overall kappa for the Lidström score improved from 0.37 (95 % CI; 0.31/0.43) to 0.59 (0.52/0.63). Conclusion The assessment technique using the uninjured side as a template for the injured side resulted only in an improved reproducibility of the radial inclination measurement which in turn resulted in an improved classification reproducibility of the reduction results. PMID:17622544

  12. Multifunctional Graphene/Platinum/Nafion Hybrids via Ice Templating

    KAUST Repository

    Estevez, Luis


    We report the synthesis of multifunctional hybrids in both films and bulk form, combining electrical and ionic conductivity with porosity and catalytic activity. The hybrids are synthesized by a two-step process: (a) ice templation of an aqueous suspension comprised of Nafion, graphite oxide, and chloroplatinic acid to form a microcellular porous network and (b) mild reduction in hydrazine or monosodium citrate which leads to graphene-supported Pt nanoparticles on a Nafion scaffold. © 2011 American Chemical Society.

  13. Template preparation for rapid PCR in Colletotrichum lindemuthianum

    Directory of Open Access Journals (Sweden)

    Roca M. Gabriela


    Full Text Available Isolation of DNA for PCR is time-consuming and involves many reagents. The aim of this work was to optimise a rapid and easy PCR methodology without previous DNA isolation. Different strains of the phytopathogenic fungus Colletotrichum lindemuthianum were used. Protoplasts were generated using lytic enzymes under high incubation temperatures using different methodologies to obtain the template. A rapid (10 minute methodology was successful for smaller amplicons (<750 bp.

  14. Verifying likelihoods for low template DNA profiles using multiple replicates (United States)

    Steele, Christopher D.; Greenhalgh, Matthew; Balding, David J.


    To date there is no generally accepted method to test the validity of algorithms used to compute likelihood ratios (LR) evaluating forensic DNA profiles from low-template and/or degraded samples. An upper bound on the LR is provided by the inverse of the match probability, which is the usual measure of weight of evidence for standard DNA profiles not subject to the stochastic effects that are the hallmark of low-template profiles. However, even for low-template profiles the LR in favour of a true prosecution hypothesis should approach this bound as the number of profiling replicates increases, provided that the queried contributor is the major contributor. Moreover, for sufficiently many replicates the standard LR for mixtures is often surpassed by the low-template LR. It follows that multiple LTDNA replicates can provide stronger evidence for a contributor to a mixture than a standard analysis of a good-quality profile. Here, we examine the performance of the likeLTD software for up to eight replicate profiling runs. We consider simulated and laboratory-generated replicates as well as resampling replicates from a real crime case. We show that LRs generated by likeLTD usually do exceed the mixture LR given sufficient replicates, are bounded above by the inverse match probability and do approach this bound closely when this is expected. We also show good performance of likeLTD even when a large majority of alleles are designated as uncertain, and suggest that there can be advantages to using different profiling sensitivities for different replicates. Overall, our results support both the validity of the underlying mathematical model and its correct implementation in the likeLTD software. PMID:25082140

  15. Cu(I)/Cu(II) templated functional pseudorotaxanes and rotaxanes

    Indian Academy of Sciences (India)

    Subrata Saha; Pradyut Ghosh


    Threaded complexes like pseudorotaxanes, rotaxanes based on Cu(I)/Cu(II) ions have shown to be promising for the construction of mechanically interlocked molecular-level architectures. In this short review, we focus on the synthetic strategies developed to construct pseudorotaxanes and rotaxanes using Cu(I)/Cu(II) ions as template. Further, brief discussions on chemical and mechanical properties associated with some of the selected to Cu(I)/Cu(II) based pseudorotaxanes and rotaxanes are presented.

  16. Haptotropic Migration of Metal Templates on Arene Surfaces

    Institute of Scientific and Technical Information of China (English)

    K.H.Dtz; H.C.Jahr; J.Bennewitz; J.Dubarle-offner


    1 Results The chromium-templated benzannulation of arylcarbenes by alkynes provides a direct regio- and diastereoselective access to densely functionalized chromium arenes[1]. The chromium fragment undergoes a haptotropic migration along the π-face of the fused arenes which can be controlled by thermodynamics,by the substitution pattern of the arene and by the metal coligand sphere(See Scheme 1).The controlled regioselective labeling of benzene rings can be exploited in diastereoselective C-C bond forma...

  17. RNA-templated DNA ligation for transcript analysis


    Nilsson, Mats; Antson, Dan-Oscar; Barbany, Gisela; Landegren, Ulf


    Ligase-mediated gene detection has proven valuable for detection and precise distinction of DNA sequence variants. We have recently shown that T4 DNA ligase can also be used to distinguish single nucleotide variants of RNA sequences. Here we describe parameters that influence RNA-templated DNA ligation by T4 DNA ligase. The reaction proceeds much more slowly, requiring more enzyme, compared to ligation of the same oligonucleotides hybridized to the corresponding DNA se...

  18. PSO-based cloning template design for CNN associative memories. (United States)

    Giaquinto, A; Fornarelli, G


    In this brief, a synthesis procedure for cellular neural networks (CNNs) with space-invariant cloning templates is proposed. The design algorithm is based on the use of the evolutionary algorithm of the particle swarm optimization (PSO) with the application to associative memories. The proposed synthesis procedure takes into account requirements in terms of robustness to parametric variations. Numerical results show that the networks also guarantee good performances in terms of correct recall in the presence of noisy patterns.

  19. Preparation of silver nanoparticle via active template under ultrasonic

    Institute of Scientific and Technical Information of China (English)

    ZHENG Min; WANG Zuo-shan; ZHU Ya-wei


    A novel method was described for the production of silver nanoparticle by using nano-carbon as active template. Special ultrasonic condition was used to assure the active effect of the template and achieve an even and stable micro-reactor system,therefore yield uniform silver nanoparticle without obvious agglomeration. By laser granularity instrument measurement, the silver nanoparticles show a mean diameter of 20.4 nm and narrow distribution between 18.7 nm and 23.0 nm according to the optimum technology. Regular spherical morphology can be observed by transmission electron microscopy(TEM). X-ray diffraction analysis indicates that Ag+ is deoxidized to form metal Ag during producing precursor, subsequent calcinations promote phase transformation from nonholonomic crystal to complete cubic crystal, which is consistent with the standard JCPDS card of silver. The results reveal that the nano-carbon in active template system not only exerts micro-reactor and steric stabilization effect, but also acts as reducing agent during the reaction.

  20. International developments in openEHR archetypes and templates. (United States)

    Leslie, Heather


    Electronic Health Records (EHRs) are a complex knowledge domain. The ability to design EHRs to cope with the changing nature of health knowledge, and to be shareable, has been elusive. A recent pilot study1 tested the applicability of the CEN 13606 as an electronic health record standard. Using openEHR archetypes and tools2, 650 clinical content specifi cations (archetypes) were created (e.g. for blood pressure) and re-used across all clinical specialties and contexts. Groups of archetypes were aggregated in templates to support clinical information gathering or viewing (e.g. 80 separate archetypes make up the routine antenatal visit record). Over 60 templates were created for use in the emergency department, antenatal care and delivery of an infant, and paediatric hearing loss assessment. The primary goal is to define a logical clinical record architecture for the NHS but potentially, with archetypes as the keystone, shareable EHRs will also be attainable. Archetype and template development work is ongoing, with associated evaluation occurring in parallel.


    Directory of Open Access Journals (Sweden)



    Full Text Available Mesoscopic high aspect ratio ferroelectric tube structures of a diverse range of compositions with tailored physical properties can be used as key components in miniaturized flexible electronics, nano- and micro-electro-mechanical systems, nonvolatile FeRAM memories, and tunable photonic applications. They are usually produced through advanced “bottom-up” or “topdown” fabrication techniques. In this study, a template wetting approach is employed for fabrication of Pb(Zr0.52Ti0.48O3 (PZT microtubes. The method is based on repeated infiltration of precursor solution into macroporous silicon (Si templates at a sub-atmospheric pressure. Prior to crystallization at 750°C, free-standing tubes of a 2-μm outer diameter, extending to over 30 μm in length were released from the Si template using a selective isotropic-pulsed XeF2 reactive ion etching. To facilitate rapid electrical characterization and enable future integration process, directed positioning and aligning of the PZT tubes was performed by dielectrophoresis. The electric field-assisted technique involves an alternating electric voltage that is applied through pre-patterned microelectrodes to a colloidal suspension of PZT tubes dispersed in isopropyl alcohol. The most efficient biasing for the assembly of tubes across the electrode gap of 12 μm was a square wave signal of 5 Vrms and 10 Hz. By varying the applied frequency in between 1 and 10 Hz, an enhancement in tube alignment was obtained.

  2. BSA-imprinted synthetic receptor for reversible template recognition. (United States)

    Wang, Huafang; He, Yunhua; He, Xiwen; Li, Wenyou; Chen, Langxing; Zhang, Yukui


    A novel approach to the manufacturing of protein-responsive imprints on a home-made chitosan substrate was established together with m-aminophenylboronic acid (APBA) as a functional monomer. The produced polymers were characterized using both (1) equilibrium adsorption assays and (2) high performance liquid chromatography analysis. Results confirmed that the synthesized BSA-MIP (molecularly imprinted polymer) has a high affinity towards its template compared to the determined control proteins. The produced BSA-MIP featured largely in its good adsorption reversibility, especially in competitive binding assays, which is of great biological significance in separations. Non-specific binding was reduced to almost zero in a BSA/BHb competitive binding event. An excellent HPLC profile of template recognition was found for BSA-MIP, even under harsh mobile phase conditions. In the present work, the adopted trapped-template-release method permits recovery of bound BSA [1]. The strategy of making an artificial protein-receptor with high adsorption affinity and reversibility is promising in on-line isolation of target protein from complicated biological environments.

  3. Synthesis and characterization of guar gum templated hybrid nano silica. (United States)

    Singh, V; Singh, S K; Pandey, S; Sanghi, R


    The objective of the present study was the fabrication of green adsorbent hybrids for which native guar gum was used as template to polymerize tetraethoxysilane. The properties and performances of the hybrids could be tailored by using varying molecular sizes of the partially depolymerized guar gum templates of various molecular sizes as control. Zn(II) uptake from aqueous solution was used as a criterion for evaluating the adsorbent efficiency. The optimum material (H4) in terms of maximum Zn(II) uptake, was obtained when the template size used was 375 kDa at a calcination temperature of 700°C. H4 was also evaluated for Ca(II), Mg(II), Cd(II) and Hg(II) adsorption. To explore the other applicability areas, the hybrids have been extensively characterized using FTIR, XRD, TGA-DTA, PL, SEM, TEM and BET analyses. H4 was found to be as efficient as previously reported vinyl modified-silica nanohybrids. It had a high surface area (264 m(2)/g) with silica nanoparticles in the size range of 90-140 nm. Being thermally very stable and photoluminescent, the material can be potentially used for many biological, medical and environmental applications.


    Directory of Open Access Journals (Sweden)

    Baranovskaya T. P.


    Full Text Available The article presents results of developing the template architecture for an enterprise of public catering. As a prototype for the template, we have selected the restaurant called Phoenix. The development pattern of architecture was based on the typical features of public catering establishments described in the business model. The main results of the study are: generalized business model, built on the method developed by A. Osterwalder, graphical layout of business processes, implemented in the tool environment, All Fusion Process Modeler (BPWin and developed models of decomposition of business processes, model business event, the location of the model functions, integration model, models, data architecture, class diagram, application portfolio and technology infrastructure. The architecture of a company of public catering may serve as a template for other businesses whose business model matches the business model of the research object. We have developed a tree of objectives and functions, the model of the enterprise, the data architecture, technology infrastructure and application portfolio are typical for the industry. The results of the study have practical value and can be used by the industry as at the design stage and improvement

  5. Secure Minutiae-Based Fingerprint Templates Using Random Triangle Hashing (United States)

    Jin, Zhe; Jin Teoh, Andrew Beng; Ong, Thian Song; Tee, Connie

    Due to privacy concern on the widespread use of biometric authentication systems, biometric template protection has gained great attention in the biometric research recently. It is a challenging task to design a biometric template protection scheme which is anonymous, revocable and noninvertible while maintaining acceptable performance. Many methods have been proposed to resolve this problem, and cancelable biometrics is one of them. In this paper, we propose a scheme coined as Random Triangle Hashing which follows the concept of cancelable biometrics in the fingerprint domain. In this method, re-alignment of fingerprints is not required as all the minutiae are translated into a pre-defined 2 dimensional space based on a reference minutia. After that, the proposed Random Triangle hashing method is used to enforce the one-way property (non-invertibility) of the biometric template. The proposed method is resistant to minor translation error and rotation distortion. Finally, the hash vectors are converted into bit-strings to be stored in the database. The proposed method is evaluated using the public database FVC2004 DB1. An EER of less than 1% is achieved by using the proposed method.

  6. Template-assisted growth of transparent plasmonic nanowire electrodes (United States)

    Caterina Giordano, Maria; Repetto, Diego; Mennucci, Carlo; Carrara, Angelica; Buatier de Mongeot, Francesco


    Self-organized nanowire arrays are confined by glancing-angle Au deposition on nanopatterned glass templates prepared by ion beam sputtering. The semi-transparent 1D nanowire arrays are extended over large cm2 areas and are endowed with excellent electrical conductivity competitive with the best transparent conductive oxides (sheet resistance in the range of 5-20 Ohm sq-1). In addition, the nanowires support localized surface plasmon (LSP) resonances, which are easily tunable into the visible and near infrared spectrum and are selectively excited with incident light polarized perpendicularly to the wires. Such substrates, thus, behave as multifunctional nanoelectrodes, which combine good optoelectronic performance with dichroic plasmonic excitation. The electrical percolation process of the Au nanoelectrodes was monitored in situ during growth at glancing angle, both on flat and nanopatterned glass templates. In the first case, we observed a universal scaling of the differential percolation rate, independently of the glancing deposition angle, while deviations from the universal scaling were observed when Au was confined on nanopatterned templates. In the latter case, the pronounced shadowing effect promotes the growth of locally connected 1D Au nanosticks on the ‘illuminated’ ripple ridges, thus, introducing strong anisotropies with respect to the case of a 2D percolating network.

  7. Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia (United States)

    Sherly, K. B.; Rakesh, K.


    Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl2ṡ8H2O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

  8. Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Sherly, K. B.; Rakesh, K. [Mahatma Gandhi University Regional Research Center in Chemistry, Department of Chemistry, Mar Athanasius College, Kothamangalam-686666, Kerala (India)


    Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl{sub 2}⋅8H{sub 2}O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

  9. Physical controls on directed virus assembly at nanoscale chemical templates

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, C L; Chung, S; Chatterji, A; Lin, T; Johnson, J E; Hok, S; Perkins, J; De Yoreo, J


    Viruses are attractive building blocks for nanoscale heterostructures, but little is understood about the physical principles governing their directed assembly. In-situ force microscopy was used to investigate organization of Cowpea Mosaic Virus engineered to bind specifically and reversibly at nanoscale chemical templates with sub-30nm features. Morphological evolution and assembly kinetics were measured as virus flux and inter-viral potential were varied. The resulting morphologies were similar to those of atomic-scale epitaxial systems, but the underlying thermodynamics was analogous to that of colloidal systems in confined geometries. The 1D templates biased the location of initial cluster formation, introduced asymmetric sticking probabilities, and drove 1D and 2D condensation at subcritical volume fractions. The growth kinetics followed a t{sup 1/2} law controlled by the slow diffusion of viruses. The lateral expansion of virus clusters that initially form on the 1D templates following introduction of polyethylene glycol (PEG) into the solution suggests a significant role for weak interaction.

  10. Chitosan as template for the synthesis of ceria nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sifontes, A.B., E-mail: [Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of); Gonzalez, G.; Ochoa, J.L. [Centro de Ingenieria, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of); Tovar, L.M.; Zoltan, T. [Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A (Venezuela, Bolivarian Republic of); Canizales, E. [PDVSA, Intevep, Caracas 1020-A (Venezuela, Bolivarian Republic of)


    Graphical abstract: Cerium oxide nanoparticles with cubic fluorite structure were prepared using chitosan as template, cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. Calcinated powders at 350 {sup o}C contain agglomerated particles with average particle size of {approx}4 nm, very high porosity and foam-like morphology formed by open and close pores. Highlights: {yields} Pure CeO{sub 2} nanoparticles can take place using chitosan as template. {yields} A porous material was obtained. {yields} Blueshifts in the ultraviolet absorption spectra have been observed in cerium oxide nanocrystallites. -- Abstract: Cerium oxide (CeO{sub 2}), nanoparticles were prepared using chitosan as template, cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. The resultant ceria-chitosan spheres were calcined at 350 {sup o}C. The synthesized powders were characterized by, XRD, HRTEM, UV-vis, FTIR, and TG-DTA. The average size of the nanoparticles obtained was {approx}4 nm and BET specific surface area {approx}105 m{sup 2} g{sup -1}. Blueshifts in the ultraviolet absorption spectra have been observed in cerium oxide nanocrystallites. The band-gap was found to be 4.5 eV. The blueshifts are well explained for diameters down to less than a few nanometers by the change in the electronic band structure.

  11. Regeneration of spines and pedicellariae in echinoderms: a review. (United States)

    Dubois, P; Ameye, L


    Morphogenesis of tissues during regeneration of echinoderm spines and pedicellariae is reviewed. Regeneration of the skeleton is rather well documented while that of associated soft tissues is poorly investigated. In particular, little information is available on the early regeneration stages which follow wound healing. From the available information, it is suggested that regeneration of broken spines proceeds through a morphallactic process of which the organizational information, as well as the involved cells, lies in the stump. In contrast, regeneration of removed spines and pedicellariae may depend on an epimorphic process whose organizational information could be located in the mutable connective tissue that joins the appendage to the main body wall.

  12. Mammalian Cochlear Hair Cell Regeneration and Ribbon Synapse Reformation

    Directory of Open Access Journals (Sweden)

    Xiaoling Lu


    Full Text Available Hair cells (HCs are the sensory preceptor cells in the inner ear, which play an important role in hearing and balance. The HCs of organ of Corti are susceptible to noise, ototoxic drugs, and infections, thus resulting in permanent hearing loss. Recent approaches of HCs regeneration provide new directions for finding the treatment of sensor neural deafness. To have normal hearing function, the regenerated HCs must be reinnervated by nerve fibers and reform ribbon synapse with the dendrite of spiral ganglion neuron through nerve regeneration. In this review, we discuss the research progress in HC regeneration, the synaptic plasticity, and the reinnervation of new regenerated HCs in mammalian inner ear.

  13. High resolution nanoimprint templates for dual damascene: fabrication and imprint results (United States)

    Irmscher, Mathias; Butschke, Joerg; Carpio, Ron; Chao, Brook; Jen, Wei-Lun; Koepernik, Corinna; Nedelmann, Lorenz; Owens, Jordan; Palmieri, Frank; Pritschow, Marcus; Reuter, Christian; Sailer, Holger; Satoodeh, Ken; Wetzel, Jeff; Wilks, Bruce; Willson, Grant


    A dual damascene template fabrication process has been developed, which enables the structuring of high-resolution, high-aspect pillars on top of lines. Based on this technology templates with three different designs have been fabricated and characterized. Two templates are dedicated for an assessment of the fabrication process using a regular test design on one hand and an arbitrary CMOS design on the other hand. With the third template via chains shall be later realized as demonstrator for electrical tests. The templates have been imprinted in resist and sacrificial material on an Imprio 55 and an Imprio 100 tool. The usability of each fabricated template could be confirmed for the specific application. For the template manufacturing a Vistec variable shape e-beam (VSB) writer SB352HR and appropriate positive-tone and negative-tone chemically amplified resists (CAR) have been used.

  14. Perkembangan Terkini Membran Guided Tissue Regeneration/Guided Bone Regeneration sebagai Terapi Regenerasi Jaringan Periodontal

    Directory of Open Access Journals (Sweden)

    Cindy Cahaya


    kombinasi prosedur-prosedur di atas, termasuk prosedur bedah restoratif yang berhubungan dengan rehabilitasi oral dengan penempatan dental implan. Pada tingkat selular, regenerasi periodontal adalah proses kompleks yang membutuhkan proliferasi yang terorganisasi, differensiasi dan pengembangan berbagai tipe sel untuk membentuk perlekatan periodontal. Rasionalisasi penggunaan guided tissue regeneration sebagai membran pembatas adalah menahan epitel dan gingiva jaringan pendukung, sebagai barrier membrane mempertahankan ruang dan gigi serta menstabilkan bekuan darah. Pada makalah ini akan dibahas sekilas mengenai 1. Proses penyembuhan terapi periodontal meliputi regenerasi, repair ataupun pembentukan perlekatan baru. 2. Periodontal spesific tissue engineering. 3. Berbagai jenis membran/guided tissue regeneration yang beredar di pasaran dengan keuntungan dan kerugian sekaligus karakteristik masing-masing membran. 4. Perkembangan membran terbaru sebagai terapi regenerasi penyakit periodontal. Tujuan penulisan untuk memberi gambaran masa depan mengenai terapi regenerasi yang menjanjikan sebagai perkembangan terapi penyakit periodontal.   Latest Development of Guided Tissue Regeneration and Guided Bone Regeneration Membrane as Regenerative Therapy on Periodontal Tissue. Periodontitis is a patological state which influences the integrity of periodontal system that could lead to the destruction of the periodontal tissue and end up with tooth loss. Currently, there are so many researches and efforts to regenerate periodontal tissue, not only to stop the process of the disease but also to reconstruct the periodontal tissue. Periodontal regenerative therapy aims at directing the growth of new bone, cementum and periodontal ligament on the affected teeth. Regenerative procedures consist of soft tissue graft, bone graft, roots biomodification, guided tissue regeneration and combination of the procedures, including restorative surgical procedure that is

  15. Regeneration of limb joints in the axolotl (Ambystoma mexicanum.

    Directory of Open Access Journals (Sweden)

    Jangwoo Lee

    Full Text Available In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

  16. Regeneration of limb joints in the axolotl (Ambystoma mexicanum). (United States)

    Lee, Jangwoo; Gardiner, David M


    In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander) model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

  17. A histone demethylase is necessary for regeneration in zebrafish. (United States)

    Stewart, Scott; Tsun, Zhi-Yang; Izpisua Belmonte, Juan Carlos


    Urodele amphibians and teleost fish regenerate amputated body parts via a process called epimorphic regeneration. A hallmark of this phenomenon is the reactivation of silenced developmental regulatory genes that previously functioned during embryonic patterning. We demonstrate that histone modifications silence promoters of numerous genes involved in zebrafish caudal fin regeneration. Silenced developmental regulatory genes contain bivalent me(3)K4/me(3)K27 H3 histone modifications created by the concerted action of Polycomb (PcG) and Trithorax histone methyltransferases. During regeneration, this silent, bivalent chromatin is converted to an active state by loss of repressive me(3)K27 H3 modifications, occurring at numerous genes that appear to function during regeneration. Loss-of-function studies demonstrate a requirement for a me(3)K27 H3 demethylase during fin regeneration. These results indicate that histone modifications at discreet genomic positions may serve as a crucial regulatory event in the initiation of fin regeneration.

  18. Non-Uniform Heat Transfer in Thermal Regenerators

    DEFF Research Database (Denmark)

    Jensen, Jesper Buch

    This thesis presents investigations on the heat transfer in complex heat ex- changers in general and in regenerative heat exchangers (regenerators) in par- ticular. The motivation for this work is a result of inconsistencies obeserved in the results from a series of experiments on active magnetic...... regenerators (AMRs) with parallel plates. The results suggest that random variations in the regenerator geometries causes maldistributed fluid flow inside the regener- ators, which affects the regenerator performance. In order to study the heat transfer processes in regenerators with non-uniform geometries......, a numerical model, which simulates a single-blow operation in a parallel-plate regenerator, was developed and used to model the heat transfer under various conditions. In addition to the modeling of the heat transfer, a series of experiments on passive regenerators with non-uniform, but precisely controlled...

  19. Vertebrate-like regeneration in the invertebrate chordate amphioxus. (United States)

    Somorjai, Ildikó M L; Somorjai, Rajmund L; Garcia-Fernàndez, Jordi; Escrivà, Hector


    An important question in biology is why some animals are able to regenerate, whereas others are not. The basal chordate amphioxus is uniquely positioned to address the evolution of regeneration. We report here the high regeneration potential of the European amphioxus Branchiostoma lanceolatum. Adults regenerate both anterior and posterior structures, including neural tube, notochord, fin, and muscle. Development of a classifier based on tail regeneration profiles predicts the assignment of young and old adults to their own class with >94% accuracy. The process involves loss of differentiated characteristics, formation of an msx-expressing blastema, and neurogenesis. Moreover, regeneration is linked to the activation of satellite-like Pax3/7 progenitor cells, the extent of which declines with size and age. Our results provide a framework for understanding the evolution and diversity of regeneration mechanisms in vertebrates.

  20. Modulation of tissue repair by regeneration enhancer elements. (United States)

    Kang, Junsu; Hu, Jianxin; Karra, Ravi; Dickson, Amy L; Tornini, Valerie A; Nachtrab, Gregory; Gemberling, Matthew; Goldman, Joseph A; Black, Brian L; Poss, Kenneth D


    How tissue regeneration programs are triggered by injury has received limited research attention. Here we investigate the existence of enhancer regulatory elements that are activated in regenerating tissue. Transcriptomic analyses reveal that leptin b (lepb) is highly induced in regenerating hearts and fins of zebrafish. Epigenetic profiling identified a short DNA sequence element upstream and distal to lepb that acquires open chromatin marks during regeneration and enables injury-dependent expression from minimal promoters. This element could activate expression in injured neonatal mouse tissues and was divisible into tissue-specific modules sufficient for expression in regenerating zebrafish fins or hearts. Simple enhancer-effector transgenes employing lepb-linked sequences upstream of pro- or anti-regenerative factors controlled the efficacy of regeneration in zebrafish. Our findings provide evidence for 'tissue regeneration enhancer elements' (TREEs) that trigger gene expression in injury sites and can be engineered to modulate the regenerative potential of vertebrate organs.