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Sample records for radiation sterilized demineralized

  1. Ethylene oxide gas sterilization does not reduce the osteoinductive potential of demineralized bone in rats

    DEFF Research Database (Denmark)

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

    1995-01-01

    It has been shown that different sterilization procedures of demineralized bone may influence its osteoinductive properties. The aim of this study was to evaluate the effect of ethylene oxide sterilization for 1, 3, and 6 hours on the osteoinductive potential of allogeneic demineralized bone...... without prior sterilization of the material, whereas the demineralized bone implanted in Groups B, C, and D had been sterilized in ethylene oxide gas for 1, 3, or 6 hours, respectively, and aerated for 48 hours. At 4 weeks postoperatively, bone formation was evaluated quantitatively by strontium 85 uptake...

  2. Effect of ethylene oxide sterilization on enamel and dentin demineralization in vitro.

    Science.gov (United States)

    Thomas, Renske Z; Ruben, Jan L; ten Bosch, Jaap J; Huysmans, Marie-Charlotte D N J M

    2007-07-01

    For in situ studies into caries prevention, sterilization of tooth samples is essential. However, sterilization may influence the caries process itself. The aim of this study was to assess the effect of sterilising sound human enamel and dentin with ethylene oxide on lesion depth and mineral loss before and after in vitro demineralization. Lesion depth and mineral loss were measured using transversal microradiography (TMR). The experiment was carried out with 32 enamel and 32 dentin samples. We found a significant reduction of lesion depth due to sterilization in demineralized enamel (-9.8microm; 95% CI: -15.1 to -4.4microm). The small effect of sterilization on demineralized enamel is considered to be irrelevant for in situ studies of de- and remineralization.

  3. The difference of saline and sterile water for tetracycline hydrochloride solvents in cementum demineralization

    Directory of Open Access Journals (Sweden)

    Shinta Ferronika

    2016-12-01

    Full Text Available Background: The root cementum demineralization is an important step in regenerative periodontal therapy to smear layer removal on the root surface. Smear layer on the root surface becomes a barrier of the new attachment between periodontal tissues with the root surface. The use of tetracycline capsules as root surface demineralizing agent cannot be applied directly on the root surface and solvents such as saline or sterile water are needed. Purpose: The aim of this study was to determine differences between sterile water and saline solvent for tetracycline HCl (tetra HCl as a cementum demineralization. Method: In this study the specimens were divided into three groups: a control, tetra HCl dissolved in saline, and tetra HCl dissolved in sterile water. Application using burnishing method for 3 minutes. Samples were dehydrated with ethanol series of 30% to 100%. Results of the root demineralization observed by scanning electron microscopy (SEM. Statistical analysis was performed using the Kruskal-Wallis followed by a Mann-Whitney nonparametric test. Result: Upon statistical analysis showed that the sterile water as a solvent of tetra HCl is more effective in smear layer removal and collagen structure exposure in the cementum. Conclusion: Tetra HCl dissolved in sterile water was found to be the best root cementum demineralization agent.

  4. Effects of ionizing radiation on proteins in lyophilized or frozen demineralized human bone

    OpenAIRE

    Antebi, Uri; Mathor, Monica Beatriz; da Silva, André Ferreira; Guimarães, Rodrigo Pereira; Honda, Emerson Kiyoshi

    2016-01-01

    OBJECTIVE: The aim was to study the effects of application of ionizing radiation (gamma and electrons) as sterilizing agents at doses of 15 kGy, 25 kGy and 50 kGy, on lyophilized or frozen demineralized bone tissue for use in transplants. METHODS: Five human femoral diaphyses from different donors of musculoskeletal tissue were demineralized and preserved as lyophilized or frozen at -80 °C. The samples were divided into two groups: non-irradiated (control) and irradiated by means of gamma ...

  5. Documentation requirements for radiation sterilization

    DEFF Research Database (Denmark)

    Miller, A.

    1995-01-01

    Several standards are recently approved or are under development by the standard organizations ISO and CEN in the field of radiation sterilization. Particularly in Europe these standards define new requirements on some issues and on other issues they emphasize the necessary documentation for appr......Several standards are recently approved or are under development by the standard organizations ISO and CEN in the field of radiation sterilization. Particularly in Europe these standards define new requirements on some issues and on other issues they emphasize the necessary documentation...... for approval of radiation sterilized products. The impact of these standards on the radiation sterilization is discussed, with special attention given to a few special issues, mainly traceability and uncertainty of measurement results....

  6. Effects of ionizing radiation on proteins in demineralized, lyophilized or frozen human bone

    Energy Technology Data Exchange (ETDEWEB)

    Antebi, Uri; Mathor, Monica B., E-mail: uri@usp.br, E-mail: mathor@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Guimaraes, Rodrigo P., E-mail: clinicaguimaraes@gmail.com [Santa Casa de Sao Paulo (FCM/SCSP), Sao Paulo, SP (Brazil). Faculdade de Ciencias Medicas

    2015-07-01

    The aim is the study of the application of ionizing radiation (gamma and electron) as sterilizing agents at doses of 15 kGy, 25 kGy and 50 kGy, the demineralized bone tissue frozen and freeze-dried for use in transplants. Five human femoral diaphysis of different donors demineralized bone tissues were preserved as lyophilized or frozen at - 80 deg C. The samples were divided into non-irradiated groups (control) and irradiated by gamma rays or electron beam. The bone proteins were extracted and used to determine the concentrations of total protein, BMP 2 and 7. It was observed a decrease in total protein concentrations, and BMP 2 and 7. The decrease in total protein concentrations, as compared to respective control groups was significant in the lyophilized and frozen samples irradiated at a dose of 50 kGy gamma radiation and beam electrons with greater than 30% reduction. The significant decrease in the levels of BMP 2 and 7 were also observed in higher doses and especially by electron beam. The reductions in the concentrations of total protein and osteoinductive proteins (BMP 2 and 7), were related to the radiation dose, i.e., increase with higher doses of ionizing radiation type and the type of preservation of the bones. The largest reductions in concentrations were observed in bone irradiated by electron beam and at a dose of 50 kGy. But this type of radiation and this high dose are not usual practice for the sterilization of bone tissue. Keywords: demineralized bone tissue, ionizing radiation, Tissue Bank, BMP 2, BMP 7, bone proteins. (author)

  7. Radiation sterilization of skin allograft

    Energy Technology Data Exchange (ETDEWEB)

    Kairiyama, E. [Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon No. 15, (B1802AYA) Ezeiza, Buenos Aires (Argentina)], E-mail: kairiyam@cae.cnea.gov.ar; Horak, C.; Spinosa, M.; Pachado, J. [Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon No. 15, (B1802AYA) Ezeiza, Buenos Aires (Argentina); Schwint, O. [J.P. Garrahan Hospital, Buenos Aires (Argentina)

    2009-07-15

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10{sup -6}. The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm{sup 2}. The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  8. Radiation sterilization of skin allograft

    Science.gov (United States)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-07-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6. The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2. The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  9. Effects of ionizing radiation on proteins in lyophilized or frozen demineralized human bone

    Directory of Open Access Journals (Sweden)

    Uri Antebi

    2016-04-01

    Full Text Available OBJECTIVE: The aim was to study the effects of application of ionizing radiation (gamma and electrons as sterilizing agents at doses of 15 kGy, 25 kGy and 50 kGy, on lyophilized or frozen demineralized bone tissue for use in transplants. METHODS: Five human femoral diaphyses from different donors of musculoskeletal tissue were demineralized and preserved as lyophilized or frozen at -80 °C. The samples were divided into two groups: non-irradiated (control and irradiated by means of gamma rays or an electron beam. The bone proteins were extracted and used to determine the concentrations of total protein and BMP 2 and 7. RESULTS: Decreases in total protein and BMP 2 and 7 concentrations were observed. The decreases in total protein concentrations, in comparison with the respective control groups, were significant in the lyophilized and frozen samples that were irradiated at a dose of 50 kGy of gamma radiation and electron beam, with reductions of more than 30%. Significant decreases in the levels of BMP 2 and 7 were also observed at higher doses and especially through use of the electron beam. CONCLUSION: The reductions in the concentrations of total proteins and osteoinductive proteins (BMP 2 and 7 were related to the radiation dose, i.e. they increased with higher doses of ionizing radiation type and the type of bone preservation. The largest reductions in concentrations were observed in the bones irradiated by means of an electron beam and at a dose of 50 kGy. However, this type of radiation and this high dose are not usual practices for sterilization of bone tissue.

  10. Effects of ionizing radiation on proteins in lyophilized or frozen demineralized human bone.

    Science.gov (United States)

    Antebi, Uri; Mathor, Monica Beatriz; da Silva, André Ferreira; Guimarães, Rodrigo Pereira; Honda, Emerson Kiyoshi

    2016-01-01

    The aim was to study the effects of application of ionizing radiation (gamma and electrons) as sterilizing agents at doses of 15 kGy, 25 kGy and 50 kGy, on lyophilized or frozen demineralized bone tissue for use in transplants. Five human femoral diaphyses from different donors of musculoskeletal tissue were demineralized and preserved as lyophilized or frozen at -80 °C. The samples were divided into two groups: non-irradiated (control) and irradiated by means of gamma rays or an electron beam. The bone proteins were extracted and used to determine the concentrations of total protein and BMP 2 and 7. Decreases in total protein and BMP 2 and 7 concentrations were observed. The decreases in total protein concentrations, in comparison with the respective control groups, were significant in the lyophilized and frozen samples that were irradiated at a dose of 50 kGy of gamma radiation and electron beam, with reductions of more than 30%. Significant decreases in the levels of BMP 2 and 7 were also observed at higher doses and especially through use of the electron beam. The reductions in the concentrations of total proteins and osteoinductive proteins (BMP 2 and 7) were related to the radiation dose, i.e. they increased with higher doses of ionizing radiation type and the type of bone preservation. The largest reductions in concentrations were observed in the bones irradiated by means of an electron beam and at a dose of 50 kGy. However, this type of radiation and this high dose are not usual practices for sterilization of bone tissue.

  11. Radiation sterilization of new drug delivery systems

    OpenAIRE

    Abuhanoğlu, Gürhan; Özer, A. Yekta

    2014-01-01

    Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, m...

  12. Radiation sterilization of medical devices; Radiacyjna sterylizacja sprzetu medycznego

    Energy Technology Data Exchange (ETDEWEB)

    Kaluska, I.; Stuglik, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1996-12-31

    Overview of sterilization methods of medical devices has been given, with the special stress put on radiation sterilization. A typical validation program for radiation sterilization has been shown and also a comparison of European and ISO standards concerning radiation sterilization has been discussed. (author). 13 refs, 1 fig., 2 tabs.

  13. Radiation sterilization of aseptically manufactured products.

    Science.gov (United States)

    Fairand, Barry P; Fidopiastis, Niki

    2010-01-01

    This paper discusses an approach for establishing a sterilization dose for an aseptically processed product after the product is in its final packaged state, in other words, terminal sterilization. It applies to aseptic processes where the fill/finish operation is conducted in a closed system using isolator or restricted access barrier technology, that is, no human intervention. The example that is given in this paper uses gamma radiation as the sterilizing agent. Other forms of radiation such as high-energy electrons or X-rays also could serve as the sterilizing agent. The proposed approach involves irradiation of the aseptically processed product at very low doses of radiation, which is possible due to the extremely low levels of bioburden that may be present on the product following a fill/finish operation. Rather than sacrificing a large number of product units that may be required to obtain a statistically significant sampling of the product for bioburden analysis and other test purposes, the test unit is a surrogate consisting of actual pharmaceutical product that was inoculated with a highly radiation-resistant micro-organism. Selection of the microorganism was based on analysis of a library of environmental monitoring data taken from the aseptic area. Because of microbial diversity between different aseptic processing facilities, selection of the test microorganism would depend on the aseptic area under study. The approach that is discussed in this paper addresses selection and preparation of the surrogate, test of sterility of the surrogate following irradiation, determination of the radiation resistance of the test microorganism, and application of the approach to calculate a sterilization dose that is less than 10 kGy. At this low dose, it may be possible to terminally sterilize radiation-sensitive pharmaceutical products, for example, those in liquid form. Additional studies are warranted to determine the general applicability of the proposed approach.

  14. Effect of ethylene oxide sterilization on enamel and dentin demineralization in vitro

    NARCIS (Netherlands)

    Thomas, Renske Z.; Ruben, Jan L.; ten Bosch, Jaap J.; Huysmans, Marie-Charlotte D. N. J. M.

    For in situ studies into caries prevention, sterilization of tooth samples is essential. However, sterilization may influence the caries process itself. The aim of this study was to assess the effect of sterilising sound human enamel and dentin with ethylene oxide on lesion depth and mineral loss

  15. Gamma radiation sterilization of Bactrocera invadens (Diptera ...

    African Journals Online (AJOL)

    The African invader fly, Bactrocera invadens, an invasive pest in Africa since 2003, causes damage and poses a threat to the mango and horticultural industry. Its control is therefore needed. Sterilization of males using gamma radiation doses (25, 50 and 75 Gy) as a means of population control was investigated. Irradiation ...

  16. Dose mapping for documentation of radiation sterilization

    DEFF Research Database (Denmark)

    Miller, A.

    1999-01-01

    The radiation sterilization standards EN 552 and ISO 11137 require that dose mapping in real or simulated product be carried in connection with the process qualification. This paper reviews the recommendations given in the standards and discusses the difficulties and limitations of practical dose...

  17. Radappertization (Radiation Sterilization) of Foods

    Science.gov (United States)

    1976-12-01

    PORK SAUSAGE . A. Anellis, D. Berkowitz, w. Swantak, and C. Strojan. Applied Microbiology, Vol • .?l±.= 453-462 (1972). S-63-C QUALITATNE AND...Eviscerated Haddock on Postirradiation Shelflife of Fillets. v. G. Ampola and L. J. Ronsivalli. P• 27. 1970 Vol 35 Pasteurization of Pacific...Oysters by Radiation, Post-Mortem Changes in Nucleotides During Storage at 0-2°C. E. J. Guardia and A. M. Ibllar. p. 22. 30 Radiation Pasteurization of

  18. Gamma radiation sterilized amnion: use in ophthalmology

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Leon T, Y. [Hospital General Regional 220, IMSS, Paseo Tollocan No. 620, Col. Vertice, Toluca 50150, Estado de Mexico (Mexico); Vazquez M, L., E-mail: esther.martinez@inin.gob.m [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06720 Mexico D. F. (Mexico)

    2010-10-15

    Amnion processed at the Radio sterilized Tissue Bank at the National Institute of Nuclear Research, sterilized with {sup 60}Co gamma radiation, have been used in Mexico since 2005 either as a graft to replace the damaged ocular surface, or as a patch to prevent unwanted inflammatory reactions. Patients from the Hospital General de Mexico (HGM) and Instituto Mexicano del Seguro Social (IMSS), suffering diverse pathologies such as keratoconjunctivitis; recurrent pterygium associated with symblepharon; corneal neuro trophic ulcers, chemical and thermal burns, and corneal thinning s, had been successfully treated with irradiated amnion. In the HGM, a clinical prospective study on lesions of the ocular surface of 17 eyes from 15 patients, affected with the above mentioned pathologies, was successful in 88.2%. The results have proven to be excellent as much for cosmetic purposes as for functional ones. Without the treatment, the patients could have suffered a healing after-effect or loss of sight. At IMSS, a controlled clinical randomized trial with 108 eyes from 100 patients, affected with primary nasal pterygium, was performed in 2009. These eyes were treated with radio sterilized amnion and intraoperative mitomycin C to prevent recurrence after excision of the primary pterygium. The preliminary results do not shown adverse reaction, inflammation and pain were significantly reduced radio sterilized amnion also offer security because they do no express antigens HLA-A, B or Dr and the sterile irradiated tissue do not provoke rejection or transmit an infective disease. (Author)

  19. Experiences using IAEA Code of practice for radiation sterilization of tissue allografts: Validation and routine control

    Energy Technology Data Exchange (ETDEWEB)

    Hilmy, N. [Batan Research Tissue Bank (BRTB), Centre for Research and Development of Isotopes and Radiation Technology, P.O. Box 7002, JKSKL, Jakarta 12070 (Indonesia)], E-mail: nazly@batan.go.id; Febrida, A.; Basril, A. [Batan Research Tissue Bank (BRTB), Centre for Research and Development of Isotopes and Radiation Technology, P.O. Box 7002, JKSKL, Jakarta 12070 (Indonesia)

    2007-11-15

    Problems of tissue allografts in using International Standard (ISO) 11137 for validation of radiation sterilization dose (RSD) are limited and low numbers of uniform samples per production batch, those are products obtained from one donor. Allograft is a graft transplanted between two different individuals of the same species. The minimum number of uniform samples needed for verification dose (VD) experiment at the selected sterility assurance level (SAL) per production batch according to the IAEA Code is 20, i.e., 10 for bio-burden determination and the remaining 10 for sterilization test. Three methods of the IAEA Code have been used for validation of RSD, i.e., method A1 that is a modification of method 1 of ISO 11137:1995, method B (ISO 13409:1996), and method C (AAMI TIR 27:2001). This paper describes VD experiments using uniform products obtained from one cadaver donor, i.e., cancellous bones, demineralized bone powders and amnion grafts from one life donor. Results of the verification dose experiments show that RSD is 15.4 kGy for cancellous and demineralized bone grafts and 19.2 kGy for amnion grafts according to method A1 and 25 kGy according to methods B and C.

  20. Experiences using IAEA Code of practice for radiation sterilization of tissue allografts: Validation and routine control

    Science.gov (United States)

    Hilmy, N.; Febrida, A.; Basril, A.

    2007-11-01

    Problems of tissue allografts in using International Standard (ISO) 11137 for validation of radiation sterilization dose (RSD) are limited and low numbers of uniform samples per production batch, those are products obtained from one donor. Allograft is a graft transplanted between two different individuals of the same species. The minimum number of uniform samples needed for verification dose (VD) experiment at the selected sterility assurance level (SAL) per production batch according to the IAEA Code is 20, i.e., 10 for bio-burden determination and the remaining 10 for sterilization test. Three methods of the IAEA Code have been used for validation of RSD, i.e., method A1 that is a modification of method 1 of ISO 11137:1995, method B (ISO 13409:1996), and method C (AAMI TIR 27:2001). This paper describes VD experiments using uniform products obtained from one cadaver donor, i.e., cancellous bones, demineralized bone powders and amnion grafts from one life donor. Results of the verification dose experiments show that RSD is 15.4 kGy for cancellous and demineralized bone grafts and 19.2 kGy for amnion grafts according to method A1 and 25 kGy according to methods B and C.

  1. Radiation sterilized bone response to dynamic loading.

    Science.gov (United States)

    Mardas, Marcin; Kubisz, Leszek; Biskupski, Piotr; Mielcarek, Sławomir; Stelmach-Mardas, Marta; Kałuska, Iwona

    2012-08-01

    Allogeneic bone grafts are used on a large scale in surgeries. To avoid the risk of infectious diseases, allografts should be radiation-sterilized. So far, no international consensus has been achieved regarding the optimal radiation dose. Many authors suggest that bone sterilization deteriorates bone mechanical properties. However, no data on the influence of ionizing radiation on bone dynamic mechanical properties are available. Bovine femurs from 2-year old animal were machine cut and irradiated with the doses 10, 15, 25, 35, 45 and 50 kGy. Dynamic mechanical analysis was performed at 1-10 Hz at the temperature range of 0-350 °C in 3-point bending configuration. No statistically significant differences in storage modulus were observed. However, there were significant decreased values of loss modulus between the samples irradiated with doses of 10 (↓14.3%), 15, 45 and 50 kGy (↓33.2%) and controls. It was stated that increased irradiation dose decreases the temperature where collagen denaturation process starts and increases the temperature where the collagen denaturation process finishes. It was shown that activation energy of denaturation process is significantly higher for the samples irradiated with the dose of 50 kGy (615 kJ/mol) in comparison with control samples and irradiation with other doses (100-135 kJ/mol). Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Sterilization of skin allografts by ionizing radiation.

    Science.gov (United States)

    Bourroul, Selma Cecília; Herson, Marisa Roma; Pino, Eddy; Matho, Monica Beatriz

    2002-11-01

    The skin has a fundamental role in the viability of human body. In the case of extensive wounds, skin allografts provide an alternative to cover temporarily the damaged areas. After donor screening and preservation in glycerol 85%, the skin can be stored in a Skin Bank. Glycerol at this concentration has a bacteriostatic effect after certain time of preservation. On the other hand, skin sterilization by ionizing radiation may reduce the quarentine period for transplantation in patients. The objective of this work was to evaluate allograft sterilization using two sources of ionizing radiation. Through the analysis of stress-strain, it was intended to verify possible effects of the radiation on the structure of preserved grafts. Three groups of skin samples were selected. The first group was maintained in the initial conditions, not irradiated. The second was exposed to cobalt-60, while the third one was irradiated using an Dynamitron Accelerator JOB188 electron beam. The irradiation dose was 25 kGy for both tests. Both irradiation sources, and the Instron Universal Machine used for biomechanical experiments, are installed at the Centro de Tecnologia das Radiações/Instituto de Pesquisas Energéticas e Nucleares (São Paulo, Brazil). According to the preliminary results, biomechanical characteristics of the samples irradiated seem to be maintained with regard to the non irradiated group.

  3. Radiation treatment for sterilization of packaging materials

    Science.gov (United States)

    Haji-Saeid, Mohammad; Sampa, Maria Helena O.; Chmielewski, Andrzej G.

    2007-08-01

    Treatment with gamma and electron radiation is becoming a common process for the sterilization of packages, mostly made of natural or synthetic plastics, used in the aseptic processing of foods and pharmaceuticals. The effect of irradiation on these materials is crucial for packaging engineering to understand the effects of these new treatments. Packaging material may be irradiated either prior to or after filling. The irradiation prior to filling is usually chosen for dairy products, processed food, beverages, pharmaceutical, and medical device industries in the United States, Europe, and Canada. Radiation effects on packaging material properties still need further investigation. This paper summarizes the work done by different groups and discusses recent developments in regulations and testing procedures in the field of packaging technology.

  4. Sterilization of therapeutic immunoadsorbents by ionizing radiation.

    Science.gov (United States)

    Sato, H; Kidaka, T; Hori, M

    1986-03-01

    The application of ionizing radiation (gamma-rays from 60Co) to sterilize therapeutic immunoadsorbents (IA)s was investigated. The IAs were porous bead carriers immobilizing anti-IgE antibodies and were irradiated in both the freeze-dried and precipitated (wet) states. The IgE removal (%), the IgE adsorption capacity of IA, was acceptable in terms of practical use even after an irradiation dose of 2.5 Mrad in the precipitated state; the anti-IgE antibody itself lost much of its activity, possibly because of intermolecular crosslinking of antibody molecules, after being irradiated with a dose at least of 0.5 Mrad. In the freeze-dried state only IA consisting of CPG-1400 could tolerate a dose of 2.5 Mrad. Dose-survival curves were obtained using Bacillus pumilus spores in both the freeze-dried and precipitated IAs and the D-values were calculated to be respectively 0.27 and 0.31 Mrad. Thus, ionizing radiation may be applicable for sterilizing IAs in the precipitated state and in the freeze-dried state for an IA consisting of CPG-1400 although the initial bioburden on IA should be low.

  5. Radiation sterilized bone response to dynamic loading

    Energy Technology Data Exchange (ETDEWEB)

    Mardas, Marcin, E-mail: marcin.mardas@skpp.edu.pl [Department of Oncology, Poznan University of Medical Sciences, ul. Szamarzewskiego 82/84, 60-569 Poznan (Poland); Kubisz, Leszek [Department of Biophysics, Poznan University of Medical Sciences, ul. Fredry 10, 61-701 Poznan (Poland); Biskupski, Piotr; Mielcarek, Slawomir [Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznan (Poland); Stelmach-Mardas, Marta [Department of Bromatology, Poznan University of Medical Sciences, ul. Marcelinska 420, 60-354 Poznan (Poland); Kaluska, Iwona [Centre for Radiation Research and Technology, Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland)

    2012-08-01

    Allogeneic bone grafts are used on a large scale in surgeries. To avoid the risk of infectious diseases, allografts should be radiation-sterilized. So far, no international consensus has been achieved regarding the optimal radiation dose. Many authors suggest that bone sterilization deteriorates bone mechanical properties. However, no data on the influence of ionizing radiation on bone dynamic mechanical properties are available. Bovine femurs from 2-year old animal were machine cut and irradiated with the doses 10, 15, 25, 35, 45 and 50 kGy. Dynamic mechanical analysis was performed at 1-10 Hz at the temperature range of 0-350 Degree-Sign C in 3-point bending configuration. No statistically significant differences in storage modulus were observed. However, there were significant decreased values of loss modulus between the samples irradiated with doses of 10 ({down_arrow}14.3%), 15, 45 and 50 kGy ({down_arrow}33.2%) and controls. It was stated that increased irradiation dose decreases the temperature where collagen denaturation process starts and increases the temperature where the collagen denaturation process finishes. It was shown that activation energy of denaturation process is significantly higher for the samples irradiated with the dose of 50 kGy (615 kJ/mol) in comparison with control samples and irradiation with other doses (100-135 kJ/mol). - Highlights: Black-Right-Pointing-Pointer We examine changes in the storage modulus and loss modulus of samples irradiated with doses of 10-50 kGy. Black-Right-Pointing-Pointer We examine changes in the denaturation temperature of samples irradiated with doses of 10-50 kGy. Black-Right-Pointing-Pointer We examine changes in the activation energy of denaturation process of samples irradiated with doses of 10-50 kGy.

  6. Gamma radiation sterilization of Bactrocera invadens (Diptera ...

    African Journals Online (AJOL)

    logaugwu

    2012-06-26

    Jun 26, 2012 ... Benedict and Robinson (2003) pointed out that sterilization by irradiation is presently the most practical way to sterilize insects. Reproductive sterility is induced by exposing the insects to X-rays, electron beams, or most commonly gamma rays from a Cobalt-60 or Caesium-137 source (LaChance, 1975; ...

  7. Recent developments in the radiation sterilization of pharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, G.P.; Wills, P.A.

    1988-01-01

    Recent developments appear to have contributed to the increased interest in sterilization of pharmaceuticals by gamma irradiation. The choice of a sterilizing radiation dose is no longer fixed at 25 kGray (2.5 Mrad) but rather based on the initial microbial load (bioburden) coupled with the desired sterility assurance level. Our own efforts have focused on the irradiation of beta lactam antibiotics powders, most of which are radiation stable at commonly employed sterilization doses. In parallel, efforts have been directed at minimising radiolysis in aqueous solutions by the choice of appropriate irradiation conditions. A brief review of the literature on the irradiation of pharmaceuticals is given.

  8. Cobalt-60: the heart of gamma-radiation sterilization.

    Science.gov (United States)

    Brinston, R M; Norton, J L

    1994-05-01

    Currently, more than three million cubic metres of single-use medical devices are sterilized by gamma radiation each year. The wide use of this method of sterilization is a result of the lethal effects of ionizing radiation on microbial populations and the penetrative powers of cobalt-60. This article describes how cobalt-60 is produced and used in gamma-radiation sterilization, and how it is disposed of once it has reached the end of its useful life. Cobalt-60 sources typically have a life of 20 years, at which point they are returned to the suppliers for re-encapsulation, reprocessing, recycling, or disposal.

  9. The influence of radiation sterilization on thiamphenicol

    Science.gov (United States)

    Marciniec, B.; Stawny, M.; Kozak, M.; Naskrent, M.

    2008-03-01

    The effect of ionising radiation, applied in the form of an electron beam, in the doses of 25, 100 and 400 kGy on the physical and chemical properties of thiamphenicol in solid phase has been studied by organoleptic analysis (form, colour, smell, solubility, clarity) and spectroscopic methods (UV, IR, EPR), chromatography (TLC), SEM observations, X-ray diffraction, polarimetry and thermal method (DSC). The above-discussed results have proved that on irradiation with a dose of 25 kGy no significant changes appear in thiamphenicol, apart from the formation of free radicals of the lifetime of over 352 days. On irradiation with much higher doses (100 and 400 kGy) no changes were observed in the IR spectra but the UV line intensities slightly increased at λmax = 266 and 273 nm, the colour of the powder changed, the radiolysis products appeared as detected by TLC, changes were also observed in the XRD, SEM pictures, the melting point values (DSC) and optical rotation. On the basis of DSC results a linear relation was found between the irradiation dose and the decrease in the melting point and increase in the enthalpy of melting, characterised by high correlation coefficients of r = 0.9839 and 0.9622, respectively. Moreover, a linear relation was established between the optical rotation angle and the irradiation dose, αD (°) = f(dose), characterised by the correlation coefficient r = 0.9874. The results obtained indicate that thiamphenicol can be safely subjected to radiation sterilization by the standard dose of 25 kGy.

  10. Problems associated with microbiological validation of sterilization by ionizing radiation.

    Science.gov (United States)

    Harries, J E

    1998-01-01

    Potential solutions to some of the practical problems experienced when validating products processed by radiation sterilization are discussed in this article. The standards for validation and routine control of radiation sterilization are to be revised next year and there is now an opportunity for the industry to influence the effectiveness of those revisions. Medical device manufacturers are encouraged to make views known to help ensure a simpler standard that is widely implemented.

  11. Radiation Fusion Technology for Sewage Sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M. J.; Kim, T. H.; Ryu, S. H.; Jung, I. H.; Lee, O. M.; Kim, T. H. [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2011-05-15

    Environmental regulation for effluent of sewage and wastewater treatment plant is going to be reinforced in terms of ecology toxicity and number of E.coli from 2011. Besides, it has been known that UV technology is not enough to be a sterilization tool due to regrowth of E.coli even after treatment with UV. Therefore it needs a novel technology for both restriction of E.coli regrowth and treatment of toxic materials in order to meet the environmental regulation being enforced. Electron beam has unique capabilities on destruction of chemicals and sterilization of microbial. In this study, field study on destruction of antibiotics and endocrine disruptors, reduction ecological toxicity and E.Coli regrowth was carried out using by mobile electron beam accelerator. Experimental results showed that irradiation on effluent could effectively reduce not only ecology toxicity but regrowth of E.coli by destruction of chemicals and complete sterilization

  12. Revision of the ISO and EN radiation sterilization standards

    DEFF Research Database (Denmark)

    Miller, A.; Hansen, J.

    2002-01-01

    The radiation sterilization standards, ISO 11137 and EN 552, are now being revised under "ISO lead", with the aim of producing only one international standard, although in four parts: (1) requirements. (2) dose-setting methods, (3) dose-substantiation methods and (4) dosimetry. Several aspects...... of the old standards that have caused problems, when they were used in practice, are addressed in the revision. Input from users of the standards is necessary in order that the standards be developed as useful tools in the documentation of radiation sterilization. (C) 2002 Elsevier Science Ltd. All rights...

  13. Influence of radiation sterilization on the stability of trifluorothymidine.

    Science.gov (United States)

    Horsch, P; Bigler, L; Altorfer, H R

    2001-07-17

    The influence of radiation sterilization on the stability of trifluorothymidine (TFT) was investigated. TFT was irradiated under ambient atmosphere with a 60Co-source and with an electron accelerator at 25, 50, and 100 kGy, respectively. The radiation-induced effects were determined by chromatographic and spectroscopic methods as well as potentiometrically with a fluoride selective electrode. TFT was moderately stable to ionizing radiation. The degradation induced by electron-beam irradiation was significantly (P=95%) smaller than by gamma-irradiation. The radiolysis products amounted to about 0.25% after electron-beam irradiation at 25 kGy, and to about 0.50% after gamma-irradiation, respectively. The main irradiation product was 5-trifluoromethyluracil (TFMU). In addition five further impurities were detected with HPLC. Identification of degradation products was performed using HPLC-ESI-MS. A degradation path of TFT after radiation sterilization was shown.

  14. Accredited dose measurements for validation of radiation sterilized products

    DEFF Research Database (Denmark)

    Miller, A.

    1993-01-01

    for control of radiation sterilization. The accredited services include: 1. 1. Irradiation of dosimeters and test samples with cobalt-60 gamma rays. 2. 2. Irradiation of dosimeters and test samples with 10 MeV electrons. 3. 3. Issue of and measurement with calibrated dosimeters. 4. 4. Measurement...

  15. Sterilization of peat by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F.E.; Vincent, J.M. (New South Wales Univ., Kensington (Australia). School of Microbiology)

    1981-01-01

    The effect of gamma-radiation on the survival of microorganisms has been quantified for the natural population of two types of peat. Data for several microbial types have been separately determined by regular plating and by indirect statistical probability estimates including, a wholly enclosed 'inverted-bottle' technique for higher dose levels to exclude any possibility of post-treatment contamination. The most persistent microorganisms at intermediate dosage (2.5-3.5 Mrad) were commonly a micrococcus (which closely resembled Micrococcus radiodurans) arthrobacter-like rods, myxobacteria and amoeboid forms. The persistent organisms all survived because of high resistance to ..gamma..-irradiation, not because of high initial numbers. The most numerous true bacteria (including spore-formers), actinomycetes, filamentous fungi and yeasts were all readily destroyed. Although the safety margin with the commercially recommended dose of 5 Mrad is low for some of the more resistant organisms, no change is justified at this stage since the organisms most likely to survive such a dose do not seem to seriously affect the subsequent growth and survival of rhizobia. Moreover there would be some risk of radiation-induced peat toxicity if higher doses were applied and some post-irradiation contamination will be difficult to avoid in commercial production.

  16. Radiation sterilization of enzyme hybrids with biodegradable polymers

    Science.gov (United States)

    Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

    2002-03-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate "hybrid" biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of 60Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification.

  17. Radiation sterilization of enzyme hybrids with biodegradable polymers

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu E-mail: mfuruta@riast.osakafu-u.ac.jp; Oka, Masahito; Hayashi, Toshio

    2002-03-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate 'hybrid' biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of {sup 60}Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification.

  18. Nano drug delivery systems and gamma radiation sterilization.

    Science.gov (United States)

    Sakar, F; Özer, A Y; Erdogan, S; Ekizoglu, M; Kart, D; Özalp, M; Colak, S; Zencir, Y

    2017-09-01

    In recent years, drug delivery systems such as liposomes and microparticles have been used in clinic for the treatment of different diseases and from a regulatory point of view, a parenterally applied drug and drug delivery systems must be sterile and pyrogen free. Radiation sterilization is a method recognized by pharmacopoeias to achieve sterility criteria of parenterals. It has the ability to kill microorganisms in therapeutic products. The ability of, however, irradiation might also affect the performance of drug delivery systems. One of the most critical points is irradiation dose, because certain undesirable chemical and physical changes may accompany with the irradiation, especially with the traditionally applied dose of 25 kGy. Its ionizing property may cause fragmentation of covalent bond. The care must be paid to the applied dose. In this research, the effects of gamma irradiation on different drug delivery systems such as chitosan microparticles, liposomes, niosomes and sphingosomes were investigated. According to the experimental data, it can be concluded that gamma irradiation can be a suitable sterilization technique for liposome, niosome and sphingosome dispersions. When all irradiated drug carrier systems were taken into consideration, chitosan glutamate microparticles were found as the most radioresistant drug delivery system among the others.

  19. Sterilization.

    Science.gov (United States)

    Peterson, Herbert B

    2008-01-01

    Worldwide, sterilization (tubal sterilization and vasectomy) is used by more people than any other method of contraception. All techniques of tubal sterilization in widespread use in the United States have low risks of surgical complications. Although tubal sterilization is highly effective, the risk of pregnancy varies by age and method of occlusion. Pregnancies can occur many years after the procedure, and when they do, the risk of ectopic gestation is high. There is now strong evidence against the existence of a post-tubal ligation syndrome of menstrual abnormalities. Although women who have undergone tubal sterilization are more likely than other women to undergo hysterectomy subsequently, there is no known biologic basis for this relationship. Although sterilization is intended to be permanent, expressions of regret and requests for reversal are not uncommon and are much more likely to occur among women sterilized at young ages. Tubal sterilization has little or no effect on sexual function for most women. Vasectomy is less likely than tubal sterilization to result in serious complications. Minor complications, however, are not uncommon. Vasectomy does not increase the risk of heart disease, and available evidence argues against an increase in the risk of prostate cancer, testicular cancer, or overall mortality. Whether a postvasectomy pain syndrome exists remains controversial. Although the long-term effectiveness of vasectomy is less well-studied than that for tubal sterilization, it seems likely to be at least as effective. Intrauterine devices and progestin implants are long-acting, highly effective alternatives to sterilization.

  20. Radiation and Ethylene Oxide Terminal Sterilization Experiences with Drug Eluting Stent Products

    National Research Council Canada - National Science Library

    Lambert, Byron J; Mendelson, Todd A; Craven, Michael D

    2011-01-01

    Radiation and ethylene oxide terminal sterilization are the two most frequently used processes in the medical device industry to render product within the final sterile barrier package free from viable microorganism...

  1. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Science.gov (United States)

    Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

    2007-11-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  2. [A comparative study of ethylene oxide and ionizing radiation for sterilizing bone grafts].

    Science.gov (United States)

    Sang, H; Hu, Y; Sun, Y

    1996-08-01

    To find a good way for sterilization and disinfection of bone grafts, we compared the sterilization capacity of gaseous ethylene oxide (EO) and cobalt-60 gamma radiation. The bone chips were contaminated with 10(7) bacteria per milliliter of Staphylococcus aureus ATCC 25923, Bacillus subtilis globigii 8017 and Bacillus cereus 4001, then sterilized with various doses of gaseous EO or cobalt- 60 gamma radiation. The sterilization effect of EO was more stronger and faster than that of 60Co gamma radiation. The application of moderate doses of EO for sterilizing particulate bone grafts was recommended.

  3. [Cytotoxicity of PVC tubes sterilized in ethylene oxide after gamma radiation exposure].

    Science.gov (United States)

    de Souza, Rafael Queiroz; Graziano, Kazuko Uchikawa; Ikeda, Tamiko Ichikawa; Gonçalves, Cláudia Regina; Cruz, Aurea Silveira

    2013-04-01

    Do materials sterilized using gamma rays become toxic when re-sterilized in ethylene oxide? This question guided the objective of this study, which was to investigate the potential cytotoxic effect of PVC sterilized by gamma radiation and re-sterilized with EO by the agar diffusion method in cell cultures. Nine PVC tubes were subjected to gamma radiation sterilization and were re-sterilized in EO. The tubes were divided into a total of 81 units of analysis that were tested so as to represent the internal and external surfaces and mass of each tube. It was concluded that the PVC materials sterilized in gamma radiation and re-sterilized in EO are not cytotoxic.

  4. Radiation-induced sterility for pupal and adult stages of the malaria moquito Anopheles arabiensis

    NARCIS (Netherlands)

    Helinski, M.E.H.; Parker, A.G.; Knols, B.G.J.

    2006-01-01

    Background - In the context of the Sterile Insect Technique (SIT), radiation-induced sterility in the malaria mosquito Anopheles arabiensis Patton (Diptera: Culicidae) was studied. Male mosquitoes were exposed to gamma rays in the pupal or adult stage and dose-sterility curves were determined.

  5. Radiation effect studies on anticancer drugs, cyclophosphamide and doxorubicin for radiation sterilization

    Science.gov (United States)

    Varshney, L.; Dodke, P. B.

    2004-12-01

    Two anticancer drugs, cyclophosphamide (CPH) and doxorubicin hydrochloride (DOXO), in powder form were exposed to a range of doses of 60Co gamma and electron beam radiation to study the effects of ionizing radiation. Pharmacopoeia tests, discolouration, degradation products, effect of irradiation temperature and dose rate were investigated. CPH undergoes less than 2% degradation at 30 kGy. Chromatographic studies revealed formation of several trace level degradation products, discolouration and free radicals in the irradiated CPH. N, N-bis (2-chloroethyl) group in the molecule is particularly sensitive to radiation degradation. Irradiation to 5 kGy at low temperature (77 K) did not result in significant changes. DOXO was observed to be quite radiation resistant and did not undergo significant changes in its physico-chemical properties and degradation product profile. It can be radiation sterilized at normal sterilization dose of 25 kGy.

  6. Studies on the sterilization of pharmaceutical base materials with ionizing radiation and ethylene oxide.

    Science.gov (United States)

    Woźniak-Parnowska, W; Najer, A

    1978-01-01

    The use of ionizing radiation and ethylene oxide for the sterilization of pharmaceutical base materials of animal origin, used to produce organopreparations, was studied. The materials included liver extract, pancreas extract, dried thyroid and intrinsic factor. The effective sterilizing doses for the examined materials and dependence between effective ionizing radiation dose and primary contamination were determined.

  7. Radiation sterilization of medical devices. Effects of ionizing radiation on ultra-high molecular-weight polyethylene

    Science.gov (United States)

    Buchalla, R.; Schüttler, C.; Bögl, K. W.

    1995-02-01

    Sterilization by ionizing radiation has become, next to ethylene oxide treament, the most important "cold" sterilization process for medical devices made from plastics. The effects of ionizing radiation on the most important polymer for medical devices, ultra-high molecular-weight polyethylene, are briefly described in this review.

  8. Maria Sklodowska Curie - the precursor of radiation sterilization methods

    Energy Technology Data Exchange (ETDEWEB)

    Gluszewski, Wojciech; Zagorski, Zbigniew P. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Tran, Quoc Khoi; Cortella, Laurent [CEA Grenoble, ARC-Nucleart, Atelier Regional de Conservation, Grenoble (France)

    2011-06-15

    A resolution of the 63rd Assembly of the United Nations proclaimed the year 2011 as the International Year of Chemistry. The coordinators of the event are UNESCO and the International Union of Pure and Applied Chemistry (IUPAC). The patroness of this event is Marie Curie, nee Sklodowska. Among women scientists, she was the first recipient of the Novel Prize, and among all scientists, she is the only one who has received this award in different scientific fields (in 1903 in the field of physics with Pierre Curie and Henri Becquerel, in 1911 in the field of chemistry). Considering the former Polish nationality of Marie Curie, the year 2011 has been proposed by the Polish Parliament as her year, using the name Maria Sklodowska Curie, under which she is known in Poland. Celebrating the International Year of Chemistry is a good opportunity to remember the importance of the work of Maria Sklodowska Curie for the emergence and development of many fields of science. This article is an attempt to present a view of science, as taught through modern applications of the radiation chemistry of polymetric materials and radiation sterilization. Although the real development of both ''cold'' sterilization and polymer technology occurred in the 1950's long after the death of Marie Curie Sklodowska, the original ideas go back to ther work performed in the 1920s. Sometimes, and that is the present case, a single scientist creates a new field, in spite of the fact that at the time of discovery there are no applications. The parallel development of other branches of science and technology helps the application of the original idea. (orig.)

  9. Radiation sterilization of a bifunctional cement formulation of hydroxilapatite-plaster-polymers.

    Science.gov (United States)

    Sainz Vidal, D; Rodriquez Napoles, D; Fuentes Estevez, G; Guerra, M; Arcis Soriano, W; Peon Aves, E; Diaz Argota, J M; Zaldivar Silva, D

    1999-06-18

    A sterilization method based on the use of gamma ionizing radiation was applied to a cement formulation of hydroxilapatite, plaster and polymers to be used in bone restorations in dental, aesthetic, and neurological surgery. After the cement was exposed to a dose of 21.5 kGy it reached the sterility assurance level which was necessary for its employment in surgical applications as specified by International Standard ISO ordinate 11137: Radiation Sterilization of Health Care Products. No variation in the initial cement composition or processing parameters, such as working or setting time and molding quality was observed due to sterilization. Its characteristics as a drug delivery system were also not affected. Therefore, radiation sterilization provides a feasible alternative to conventional sterilization methods such as dry/wet heat and ethylene oxide.

  10. Degradation of Biochemical Activity in Soil Sterilized by Dry Heat and Gamma Radiation

    Science.gov (United States)

    Shih, K. L.; Souza, K. A.

    1978-01-01

    The effect of soil sterilization by dry heat (0.08% relative humidity), gamma radiation, or both on soil phosphatase, urease, and decarboxylase activity was studied. Soil sterilized by a long exposure to dry heat at relatively low temperatures (eight weeks at 100.5 C) retained higher activities than did soil exposed to a higher temperature (two weeks at 124.5 C), while all activity was destroyed by four days at 148.5 C. Sterilization with 7.5 Mrads destroyed less activity than did heat sterilization. The effect of several individually nonsterizing doses of heat radiation is described.

  11. Radiation Sterilization of Anthracycline Antibiotics in Solid State

    Directory of Open Access Journals (Sweden)

    A. Kaczmarek

    2013-01-01

    Full Text Available The impact of ionizing radiation generated by a beam of electrons of 25–400 kGy on the stability of such analogs of anthracycline antibiotics as daunorubicin (DAU, doxorubicin (DOX, and epidoxorubicin (EPI was studied. Based on EPR results, it was established that unstable free radicals decay exponentially with the half-time of 4 days in DAU and DOX and 7 days in EPI after irradiation. Radiation-induced structural changes were analyzed with the use of spectrophotometric methods (UV-Vis and IR and electron microscope imaging (SEM. A chromatographic method (HPLC-DAD was applied to assess changes in the contents of the analogs in the presence of their impurities. The study showed that the structures of the analogs did not demonstrate any significant alterations at the end of the period necessary for the elimination of unstable free radicals. The separation of main substances and related substances (impurities and potential degradation products allowed determining that no statistically significant changes in the content of particular active substances occurred and that their conversion due to the presence of free radicals resulting from exposure to an irradiation of 25 kGy (prescribed to ensure sterility was not observed.

  12. Radiation sterilization of anthracycline antibiotics in solid state.

    Science.gov (United States)

    Kaczmarek, A; Cielecka-Piontek, J; Garbacki, P; Lewandowska, K; Bednarski, W; Barszcz, B; Zalewski, P; Kycler, W; Oszczapowicz, I; Jelińska, A

    2013-01-01

    The impact of ionizing radiation generated by a beam of electrons of 25-400 kGy on the stability of such analogs of anthracycline antibiotics as daunorubicin (DAU), doxorubicin (DOX), and epidoxorubicin (EPI) was studied. Based on EPR results, it was established that unstable free radicals decay exponentially with the half-time of 4 days in DAU and DOX and 7 days in EPI after irradiation. Radiation-induced structural changes were analyzed with the use of spectrophotometric methods (UV-Vis and IR) and electron microscope imaging (SEM). A chromatographic method (HPLC-DAD) was applied to assess changes in the contents of the analogs in the presence of their impurities. The study showed that the structures of the analogs did not demonstrate any significant alterations at the end of the period necessary for the elimination of unstable free radicals. The separation of main substances and related substances (impurities and potential degradation products) allowed determining that no statistically significant changes in the content of particular active substances occurred and that their conversion due to the presence of free radicals resulting from exposure to an irradiation of 25 kGy (prescribed to ensure sterility) was not observed.

  13. Radiation and ethylene oxide terminal sterilization experiences with drug eluting stent products.

    Science.gov (United States)

    Lambert, Byron J; Mendelson, Todd A; Craven, Michael D

    2011-12-01

    Radiation and ethylene oxide terminal sterilization are the two most frequently used processes in the medical device industry to render product within the final sterile barrier package free from viable microorganisms. They are efficacious, safe, and efficient approaches to the manufacture of sterile product. Terminal sterilization is routinely applied to a wide variety of commodity healthcare products (drapes, gowns, etc.) and implantable medical devices (bare metal stents, heart valves, vessel closure devices, etc.) along with products used during implantation procedures (catheters, guidewires, etc.). Terminal sterilization is also routinely used for processing combination products where devices, drugs, and/or biologics are combined on a single product. High patient safety, robust standards, routine process controls, and low-cost manufacturing are appealing aspects of terminal sterilization. As the field of combination products continues to expand and evolve, opportunity exists to expand the application of terminal sterilization to new combination products. Material compatibility challenges must be overcome to realize these opportunities. This article introduces the reader to terminal sterilization concepts, technologies, and the related standards that span different industries (pharmaceutical, medical device, biopharmaceuticals, etc.) and provides guidance on the application of these technologies. Guidance and examples of the application of terminal sterilization are discussed using experiences with drug eluting stents and bioresorbable vascular restoration devices. The examples provide insight into selecting the sterilization method, developing the process around it, and finally qualifying/validating the product in preparation for regulatory approval and commercialization. Future activities, including new sterilization technologies, are briefly discussed.

  14. The Problem of the Harmlessness of Using Food Products Sterilized by Means of Ionizing Radiation: USSR

    National Research Council Canada - National Science Library

    Yegiazarov, G

    1960-01-01

    ...) radioactivity originated in the food products. It is known further that as a result of the action of ionizing radiation there appear undesirable secondary changes in the physico-chemical and organoleptic indices of the sterilized products...

  15. Evaluation of plastic packaging materials used in radiation sterilized medical products and food

    Science.gov (United States)

    Fengmei, L. L.; Ying, W. W.; Xiaoguang, L. L.; Baoyu, Y. Y.

    2000-03-01

    This paper studied the results of evaluation on resistance to radiation, moisture permeability, bacteria permeability, tensile strength, elongation at break and sealing ability for several plastic films available on the market. The result shows that nylon, sarin, and polyethylene complex films, high and low density polyethylene films are applicable for packing of radiation sterilized products.

  16. Evaluation of safety and efficacy of radiation-sterilized bone allografts in reconstructive oral surgery

    OpenAIRE

    Krasny, Marta; Krasny, Kornel; Kami?ski, Artur; Zadurska, Ma?gorzata; Piekarczyk, Piotr; Fiedor, Piotr

    2012-01-01

    Bone grafting allows reconstruction of the atrophied or destroyed alveolar process. In orthopaedics and traumatology allogeneic grafting has been used to restore defects of osseous tissue for over 60?years. In order to improve safety of the graft recipient, sterilized allogeneic grafts have been use. The aim of the study was to assess the direct and long-term outcomes following augmentation of atrophied alveolar processes with the use of radiation-sterilized allogeneic bone grafts. Sixty-eigh...

  17. An adjustable sterile lead apron for radiation protection during angiography.

    Science.gov (United States)

    Grollman, J H; Sanchez, J L

    1979-08-01

    A simple sterile lead apron can be mounted directly on any vertical-beam image-intensifier housing and readjusted by the angiographer to shield himself from scatter during fluoroscopy and cineangiocardiography, even if the image intensifier is titled in the longitudinal plane. Properly placed, the apron effectively reduces exposed due to scatter.

  18. STUDYING OF POSSIBILITY A WILLOW WHITE (SALIX ALBA L.) BRANCHES STERILIZATION BY IONIZING RADIATION

    OpenAIRE

    Ольга Олеговна Фролова; Анна Степановна Саушкина; Майя Викторовна Мазурина; Ася Юрьевна Айрапетова; Евгения Геннадьевна Компанцева; Евгения Владимировна Компанцева

    2014-01-01

    There was determined a quantity of microorganisms in Salix alba L. branches specimens after processing by ionizing radiation (0,25–5 kGy). The powder of S. alba branches conform to recommended requirements for a standard "Microbiological purity" after processing by the minimal radiation dose, that’s why offered method of sterilization is effective. Ionizing radiation is acceptable for S. alba branches processing, because it doesn't influence significantly on the structure and the quantity of ...

  19. Spacecraft sterilization.

    Science.gov (United States)

    Kalfayan, S. H.

    1972-01-01

    Spacecraft sterilization is a vital factor in projects for the successful biological exploration of other planets. The microorganisms of major concern are the fungi and bacteria. Sterilization procedures are oriented toward the destruction of bacterial spores. Gaseous sterilants are examined, giving attention to formaldehyde, beta-propiolactone, ethylene oxide, and the chemistry of the bactericidal action of sterilants. Radiation has been seriously considered as another method for spacecraft sterilization. Dry heat sterilization is discussed together with the effects of ethylene oxide decontamination and dry heat sterilization on materials.

  20. Development of radiation sterilized dip slides for enumerating lactic acid bacteria and total count in foodstuffs

    Science.gov (United States)

    Eisenberg, E.; Padova, R.; Kirsch, E.; Weissman, Sh.; Hirshfeld, T.; Shenfeld, A.

    APT agar (APT) used for enumeration of lactic acid bacteria and Plate Count agar (PCA) applied for total count were sterilized by gamma radiation using radiation dose of 10-15 kGy. Radiosterilized PCA and APT modified by adding catalase prior to irradiation, or APT with increased content of yeast extract performed, as well as, the heat sterilized commercial media. Growth performance was evaluated on several strains of microorganisms, as well as, by enumeration of bacteria in food products. Radiosterilization of culture media in final packaging, can be applied to produce dip slide kits containing PCA or APT.

  1. The development of new radiation protocols for insect sterilization using long wavelength x-rays

    Science.gov (United States)

    Urquidi, Jacob; Brar, Ramaninder K.; Rodriguez, Stacy; Hansen, Immo

    2015-07-01

    Control of insect species for the protection of crops, livestock, and prevention of disease such as dengue fever and malaria is a high priority in today's global economy. Traditional methods such as pesticides have fallen out of favor because its effects are indiscriminate as well as adverse and unpredictable impacts on the environment. Modern novel techniques such as genetic modification have had trouble gaining traction due to ethics concerns and the potential for unforeseen side effects. One approach that has gained traction and has proven its efficacy is the use of ionizing radiation to affect sterility in insect species in order to scale back their population. Known as Sterile Insect Technique (SIT), it has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipertans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. We have investigated the effect of treatment with x-rays of different wavelengths on x-ray sterilized mosquito males. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males' longevity as well as an increase on the efficacy of sterilization while employing a substantially lower dose.

  2. Effects of radiation on inherited sterility in the European grapevine moth (Lobesia botrana).

    Science.gov (United States)

    Steinitz, Hadass; Sadeh, Adi; Kliot, Adi; Harari, Ally

    2015-01-01

    The sterile insect technique (SIT) is an alternative, environmentally friendly method for controlling insect pests. In the Lepidoptera, a low dose of gamma irradiation causes inherited sterility (SIT-IS), leading to full sterility in females but only partial sterility in males, which successfully compete with wild males for mates. This study examined the effect of a low radiation dose (150 Gy) on the fitness parameters of male and female Lobesia botrana, a polyphagous and major pest of vineyards found in the Middle East, Europe and the Americas. Irradiation of the pupae did not affect their emergence rate, flight ability out of a cylinder, male response to sex pheromone in a field cage or male or female mating success. A major effect of irradiation was observed in the significantly reduced number of irradiated females' offspring reaching pupation, and as a consequence a limited number of F2 offspring. The effect of irradiation on male partial sterility (also called inherited sterility) was reflected in the male-biased sex ratio of F1 offspring of irradiated males, the reduced number of F1 offspring and the very low number of F2 descendants. This study demonstrates the feasibility of controlling L. botrana using SIT-IS. Adding this method to the arsenal of environmentally friendly tools to control this pest may assist in further reducing the use of insecticides on edible crops. © 2014 Society of Chemical Industry.

  3. The development of new radiation protocols for insect sterilization using long wavelength x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Urquidi, Jacob, E-mail: jurquidi@nmsu.edu; Brar, Ramaninder K. [X-ray and Neutron Science Laboratory, Department of Physics, New Mexico State University, Las Cruces, NM (United States); Rodriguez, Stacy; Hansen, Immo [Molecular Vector Physiology Lab, Department of Biology, New Mexico State University, Las Cruces, NM (United States)

    2015-07-23

    Control of insect species for the protection of crops, livestock, and prevention of disease such as dengue fever and malaria is a high priority in today’s global economy. Traditional methods such as pesticides have fallen out of favor because its effects are indiscriminate as well as adverse and unpredictable impacts on the environment. Modern novel techniques such as genetic modification have had trouble gaining traction due to ethics concerns and the potential for unforeseen side effects. One approach that has gained traction and has proven its efficacy is the use of ionizing radiation to affect sterility in insect species in order to scale back their population. Known as Sterile Insect Technique (SIT), it has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipertans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. We have investigated the effect of treatment with x-rays of different wavelengths on x-ray sterilized mosquito males. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males’ longevity as well as an increase on the efficacy of sterilization while employing a substantially lower dose.

  4. Radiative decay of keV-mass sterile neutrino in magnetized electron plasma

    Directory of Open Access Journals (Sweden)

    Dobrynina Alexandra

    2017-01-01

    Full Text Available The radiative decay of sterile neutrinos with typical masses of 10 keV is investigated in the presence of an external magnetic field and degenerate electron plasma. Full account is taken of the modified photon dispersion relation relative to vacuum. The limiting cases of relativistic and nonrelativistic plasma are analyzed. The decay rate calculated in a strongly magnetized plasma, as a function of the electron number density, is compared with the unmagnetized plasma limit. It is found that the presence of the strong magnetic field in the electron plasma suppresses the catalyzing influence of the plasma by itself on the sterile-neutrino decay rate.

  5. Optical and histological evaluation in human tendon tissue sterilized by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Funari, Ana Paula; Antebi, Uri; Santos, Luiz Augusto; Vieira, Daniel Perez; Miranda, Jurandir Tomaz de; Alves, Nelson Mendes; Freitas, Anderson Zanardi de; Mathor, Monica Beatriz, E-mail: anapaulafunari@gmail.com, E-mail: mathor@ipen.br, E-mail: uri@usp.br, E-mail: luiz.santos@hc.fm.usp.br, E-mail: tomazdemiranda.j@gmail.com, E-mail: nelsonnininho@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faculdade de Ciências Médicas da Santa Casa de São Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil). Faculdade de Medicina; Universidade Federal de Santa Maria (UFSM), RS (Brazil)

    2017-11-01

    Sterilization by irradiation is a technique that is used by tissue banks aiming to eliminate contamination of human allografts, being a safe method, free of residue and used as final sterilization. After the tissue procurement, these undergo a series of processing stages and then are packaged and preserved by freezing. Despite aseptic care of the material those may be subjected to sterilization in the final packing by ionizing radiation, raising the security level of sterility of the tissue. The aim of this study was to evaluate the effects of application of ionizing radiation, produced by {sup 60}Co source in human tendons pre-processed (A-alcohol + antibiotic; B- H{sub 2}O{sub 2} + ultrasound) obtained through collaboration with tissue banks and preserved by freezing in -80° C, the radiation absorbed doses in processing were 12.5, 15 and 25 kGy, each one with their corresponding non-irradiated control, to examine possible structural or morphological alterations. The irradiated samples and their controls were analyzed by means of optical coherence tomography (OCT) and optical coherence tomography polarization sensitive (PS-OCT), and histological tests had been stained with hematoxylin-eosin (HE). According to the results the tissue processed with alcohol/antibiotic in conjunction with irradiation proved to be the most effective. (author)

  6. Radiation Sterilization of Anthracycline Antibiotics in Solid State

    OpenAIRE

    Kaczmarek, A.; Cielecka-Piontek, J.; Garbacki, P.; Lewandowska, K.; Bednarski, W.; Barszcz, B.; Zalewski, P.; Kycler, W.; Oszczapowicz, I.; Jeli?ska, A.

    2013-01-01

    The impact of ionizing radiation generated by a beam of electrons of 25–400 kGy on the stability of such analogs of anthracycline antibiotics as daunorubicin (DAU), doxorubicin (DOX), and epidoxorubicin (EPI) was studied. Based on EPR results, it was established that unstable free radicals decay exponentially with the half-time of 4 days in DAU and DOX and 7 days in EPI after irradiation. Radiation-induced structural changes were analyzed with the use of spectrophotometric methods (UV-Vis and...

  7. Cosmology favoring extra radiation and sub-eV mass sterile neutrinos as an option.

    Science.gov (United States)

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G; Tamborra, Irene; Wong, Yvonne Y Y

    2010-10-29

    Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{s} and effective number N{s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{s} is in the sub-eV range.

  8. Radiative emission of neutrino pairs in atoms and light sterile neutrinos

    Directory of Open Access Journals (Sweden)

    D.N. Dinh

    2015-03-01

    Full Text Available The process of Radiative Emission of Neutrino Pair (RENP in atoms is sensitive to the absolute neutrino mass scale, the type of spectrum neutrino masses obey and the nature – Dirac or Majorana – of massive neutrinos. We analyse the possibility to test the hypothesis of existence of neutrinos with masses at the eV scale coupled to the electron in the weak charged lepton current in an RENP experiment. The presence of eV scale neutrinos in the neutrino mixing is associated with the existence of sterile neutrinos which mix with the active flavour neutrinos. At present there are a number of hints for active–sterile neutrino oscillations driven by Δm2∼1 eV2. We perform a detailed analysis of the RENP phenomenology within the “3+1” scheme with one sterile neutrino.

  9. Microbial contamination on disposable hypodermic syringes prior to sterilization by ionizing radiation.

    Science.gov (United States)

    Cook, A M; Berry, R J

    1968-08-01

    A large number of syringes were taken from the production lines of three independent manufacturers; the numbers and types of microorganisms contaminating these randomly sampled syringes were assessed in the laboratories maintained by each of these manufacturers for routine sterility testing, according to a standard protocol devised by the Research Committee of the UK Panel on Gamma and Electron Irradiation, which coordinated the investigation and analyzed the results. Items produced by a manufacturer were assessed for microbiological contamination both in their own laboratories and in the laboratories of the other manufacturers. The level of "false-positive" results was determined independently for each laboratory by the testing of "known sterile" items which had been subjected to the radiation-sterilization process. Both the percentage of syringes initially sterile and the average number of organisms per contaminated syringe differed among the three manufacturers. When corrected for interlaboratory differences, the number of syringes initially sterile ranged from 16 to 48%, and the mean number of organisms per contaminated syringe was 20 to 70. Of 964 syringes tested by all three laboratories, only one contained over 1,000 aerobic organisms (1,133). The most common organisms found were coagulase-negative, gram-positive cocci. Two manufacturers assessed contamination by anaerobic organisms; of 610 syringes, 1 contained 4,275 organisms and 3 more had 100 to 1,000 organisms, but 488 (80%) were uncontaminated by anaerobes. The results are discussed in the context of the choice of radiation dose necessary for the sterilization of medical products manufactured under controlled hygienic conditions.

  10. Radiation-induced sterility for pupal and adult stages of the malaria mosquito Anopheles arabiensis

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2006-05-01

    Full Text Available Abstract Background In the context of the Sterile Insect Technique (SIT, radiation-induced sterility in the malaria mosquito Anopheles arabiensis Patton (Diptera: Culicidae was studied. Male mosquitoes were exposed to gamma rays in the pupal or adult stage and dose-sterility curves were determined. Methods Pupae were irradiated shortly before emergence (at 22–26 hrs of age, and adults Results Irradiation of pupae, for all doses tested, had no effect on adult emergence. Survival curves of males irradiated as pupae or adults were similar or even slightly higher than non-irradiated males. Overall, adults appeared to be slightly more susceptible to irradiation, although no significant differences for individual doses were observed. In the pupal stage, a significant negative correlation was found between insemination and dose, but the correlation-coefficient was associated with less than 25% of the total variation. A review of the literature indicated that An. arabiensis is more radiation resistant than other anopheline mosquitoes. Conclusion The optimal dose for male insects to be released in an SIT programme depends on their level of sterility and competitiveness. The use of semi-sterilizing doses to produce more competitive insects is discussed. The most convenient developmental stage for mosquito irradiation on a mass-scale are pupae, but pupal irradiation resulted in a lower insemination rate at the highest dose compared to adult irradiation. On the basis of this study, a suitable dose range that includes semi-sterilizing doses is identified to initiate competitiveness experiments for males irradiated at both developmental stages.

  11. Sterilization by ionizing radiation comparative evaluation; Sterilizzazione mediante radiazioni e confronto con le tecniche convenzionali

    Energy Technology Data Exchange (ETDEWEB)

    Tata, A. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Innovazione; Giuliani, S.

    1996-01-01

    Sterilization of surgical and medical devices by ionizing radiation (gamma or accelerated electron beams) is currently regarded as one of the main industrial-scale applications of radiation technology processes. Considering the most widely utilized chemical-physical methods (i.e. ethylene oxide (EtO) fumigation and radiation treatment), about 10-12 millions m(3) of surgical and medical devices are estimated to be processed yearly all around the world, of which 70 % by EtO, 27% by gamma-irradiation and 3% using accelerated beams. Due to the increasing demand for reusable and single-use devices, and the need of assuring their sterility in order to prevent, as much as possible, the diffusion of serious infective diseases (among which for instance Aids), the market of sterilization of these items is considerably expanding. In the general depicted scenario, radiation technologies are expected to gain a leading role, even a part from their economic attractiveness, as an alternative to EtO treatment, which is more and more considered as responsible for increasing environmental, social and public health problems.

  12. Use of gamma radiation to sterilize Ceratitis capitata (Wied., 1824), tsl VIENNA 8 strain, for application of sterile insect technique in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, Thiago de A.; Costa, Maria de L.Z.; Paesman, Leandro; Walder, Julio M.M. [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)]. E-mails: piaui@cena.usp.br; jmwalder@cena.usp.br; Mascarin, Gabriel M. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ)]. E-mail: gmmascar@esalq.usp.br

    2007-07-01

    The Sterile insect technique is a method of pest control allowed in integrated pest management programs in fruit growing, where sterile insects released compete in mate process against fertile wild ones, generating a gradual population reduction. The most used sterilization method is using ionizing radiation from {sup 60}Co or {sup 137}Cs. For efficient application of SIT, an important item is the sterilizing dose. This must be as lower as possible in order to preserve insect behavior. In this work, it was studied the reproductive potential of fruit fly Ceratitis capitata, tsl VIENNA 8 strain, irradiated with different doses of gamma radiation. This strain shall be used in population suppression programs at fruit-growing areas from Northeast of Brazil, through a partnership between CENA and Biofactory MOSCAMED Brazil, intending only sterile male releases. Radiation source used was a {sup 60}Co irradiator, with 17.2 .1012 Bq. Individualized couples were distributed in a randomized delineament with 10 replicates for each treatment and eggs were collected for fifteen days. With 9 and 10 days old, pupae were irradiated with doses ranging from 30 to 120 Gy. All means of emerged adult's percentages were higher than 90%. In regards to fecundity, different doses didn't affect the number of eggs laid, being the overall mean around 30 eggs/couple/day. Fertility data showed that as radiation dose increases, sterility increases. It was concluded that the dose of 90 Gy could be used in Brazil, since to SIT programs a dose is chosen witch prevents an egg hatch higher than 1%. (author)

  13. Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

    Science.gov (United States)

    Singh, Durgeshwer; Singh, Rita

    2012-11-01

    Wound debridement is essential for the removal of necrotic or nonviable tissue from the wound surface to create an environment conducive to healing. Nonsurgical enzymatic debridement is an attractive method due to its effectiveness and ease of use. Papain is a proteolytic enzyme derived from the fruit of Carica papaya and is capable of breaking down a variety of necrotic tissue substrates. The present study was focused on the use of gamma radiation for sterilization of papain dressing with wound debriding activity. Membranes with papain were prepared using 0.5% chitin in lithium chloride/dimethylacetamide solvent and sterilized by gamma radiation. Fluid absorption capacity of chitin-papain membranes without glycerol was 14.30±6.57% in 6 h. Incorporation of glycerol resulted in significant (psterilization of the dressings. Infrared (IR) spectral scanning has shown that papain was stable on gamma irradiation at 25-35 kGy. The irradiated chitin-papain membranes were impermeable to different bacterial strains and also exhibited strong bactericidal action against both Gram-positive and Gram-negative bacteria. The fluid handling characteristics and the antimicrobial properties of chitin-papain membranes sterilized by gamma radiation were found suitable for use as wound dressing with debriding activity.

  14. Free radical scavenging alleviates the biomechanical impairment of gamma radiation sterilized bone tissue.

    Science.gov (United States)

    Akkus, Ozan; Belaney, Ryan M; Das, Prasenjit

    2005-07-01

    Terminal sterilization of bone allografts by gamma radiation is often essential prior to their clinical use to minimize the risk of infection and disease transmission. While gamma radiation has efficacy superior to other sterilization methods it also impairs the material properties of bone allografts, which may result in premature clinical failure of the allograft. The mechanisms by which gamma radiation sterilization damages bone tissue are not well known although there is evidence that the damage is induced via free radical attack on the collagen. In the light of the existing literature, it was hypothesized that gamma radiation induced biochemical damage to bone's collagen that can be reduced by scavenging for the free radicals generated during the ionizing radiation. It was also hypothesized that this lessening of the extent of biochemical degradation of collagen will be accompanied by alleviation in the extent of biomechanical impairment secondary to gamma radiation sterilization. Standardized tensile test specimens machined from human femoral cortical bone and specimens were assigned to four treatment groups: control, scavenger treated-control, irradiated and scavenger treated-irradiated. Thiourea was selected as the free radical scavenger and it was applied in aqueous form at the concentration of 1.5 M. Monotonic and cyclic mechanical tests were conducted to evaluate the mechanical performance of the treatment groups and the biochemical integrity of collagen molecules were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native mechanical properties of bone tissue did not change by thiourea treatment only. The effect of thiourea treatment on mechanical properties of irradiated specimens were such that the post-yield energy, the fracture energy and the fatigue life of thiourea treated-irradiated treatment group were 1.9-fold, 3.3-fold and 4.7-fold greater than those of the irradiated treatment group, respectively. However, the

  15. Development and application of radiation sterilization method in Federal Medical and Biophysical centre n.a. A.I. Burnazyan

    Directory of Open Access Journals (Sweden)

    Kalashnikov V.V.

    2014-12-01

    was carried out in order to determine the sterilizing doses; to determine the maximum permissible doses of treatment; to develop irradiation technology; to develop normative and methodological base. The given study presents the results of practical work from 2000 to 2009 on radiation sterilization of MP and works to improve the methodological support of the production of such products. The scope of work was performed on the irradiation of products and conduct its microbiological control. The results of for analysis of the practice are overviewed. There were shown the basic documents for methodological support of production and the organization's role as a scientific and methodological expertise and nationwide center for radiation sterilization of MP, developed by the organization. There was presented the current status of logistical support and other features of the organization for participation in the works on radiation sterilization of MP, radiation processing of food and other materials that require microbiological decontamination.

  16. On the suitability of cerium oxide glass for terminal radiation sterilization

    Science.gov (United States)

    Janimak, J. J.; Marteleur, M.

    2004-09-01

    The affect of ammonium sulphate treatment on cerium oxide (CeO) glass vials have been assessed following exposure to ionizing radiation at 25 kGy. The bulk chemical composition of irradiated cerium oxide glass remains unchanged despite a temporary browning effect. Stability against alkali leachables of the internal silica matrix is enhanced with ammonium sulphate treatment. With exception to Alumina and Na 2O, radiation sterilization has a limited effect on altering the surface chemistry of ammonium sulphate treated cerium oxide glass.

  17. TMI-2 purification demineralizer resin study

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J D; Osterhoudt, T R

    1984-05-01

    Study of the Makeup and Purification System demineralizers at TMI-2 has established that fuel quantities in the vessels are low, precluding criticality, that the high radioactive cesium concentration on the demineralizer resins can be chemically removed, and that the demineralizer resins can probably be removed from the vessels by sluicing through existing plant piping. Radiation measurements from outside the demineralizers establishing that there is between 1.5 and 5.1 (probably 3.3) lb of fuel in the A vessel and less than that amount in the B vessel. Dose rates up to 2780 R per hour were measured on contact with the A demineralizer. Remote visual observation of the A demineralizer showed a crystalline crust overlaying amber-colored resins. The cesium activity in solid resin samples ranged from 220 to 16,900 ..mu..Ci/g. Based on this information, researchers concluded that the resins cannot be removed through the normal pathway in their present condition. Studies do show that the resins will withstand chemical processing designed to rinse and elute cesium from the resins. The process developed should work on the TMI-2 resins.

  18. Evaluation of safety and efficacy of radiation-sterilized bone allografts in reconstructive oral surgery.

    Science.gov (United States)

    Krasny, Marta; Krasny, Kornel; Kamiński, Artur; Zadurska, Małgorzata; Piekarczyk, Piotr; Fiedor, Piotr

    2013-09-01

    Bone grafting allows reconstruction of the atrophied or destroyed alveolar process. In orthopaedics and traumatology allogeneic grafting has been used to restore defects of osseous tissue for over 60 years. In order to improve safety of the graft recipient, sterilized allogeneic grafts have been use. The aim of the study was to assess the direct and long-term outcomes following augmentation of atrophied alveolar processes with the use of radiation-sterilized allogeneic bone grafts. Sixty-eight patients were surgically treated between 2004 and 2011: 29 underwent open sinus floor elevation, post-extraction alveoli augmentation was performed in 16 subjects and 23 underwent reconstruction of the atrophied alveolar process. Augmentation of bone defects used bone granulate in 63 patients and bone blocks stabilized with titanium screws in 5 patients. PRF membranes collected from the patient's blood were also used in all the procedures. In each of the cases optimal dimensions of the alveolar process were obtained allowing embedment of BIOMET 3I dental implant/-s. In all the patients the defects were successfully restored with implant-supported prostheses. Radiation-sterilized allogeneic bone grafts proved to be safe and effective for the patients and manageable for the surgeon constituting a good alternative to autogeneic material.

  19. Development of sterilized porridge for patients by combined treatment of food technology with radiation technology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaehun; Choi, Jongil; Song, Beomseok; and others

    2010-09-15

    This research was conducted to develop patient foods of high quality using a radiation fusion technology with food processing. Radiation technique to increase calorie of porridge was established, and it was investigated that radiation effects on functional materials, which can could be added to increase functionality of patient foods. Moreover, sterilized semi-fluid meal (milk porridge) for patients with higher calorie was developed by a sterilization process by gamma irradiation, combined treatments to improve the sensory qualities, and fortification with various nutrients. Also, sensory survey on irradiated commercial patient foods was performed to find the problems and improvement points of the developed products. Optimal packaging material was selected by evaluation of effect of irradiation in packaging materials and a convenient package for consuming by patients was decided. Safety of the irradiated milk porridge was confirmed by in-vivo genotoxicological test, and its nutritional composition for patients was evaluated by nutritional analysis. Finally, the milk porridge was developed as liquid, dried, powdered, and pellet type products. This research may contribute to improve life quality of patients by supplement of various foods with high quality to immuno-compromised patients. Furthermore, economic profits and technological advances are expected by commercialization of the patient foods.

  20. Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

    Science.gov (United States)

    Sung, Nak-Yun; Choi, Jong-il

    2015-06-01

    Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants

  1. The Efficacy of Ultraviolet Radiation for Sterilizing Tools Used for Surgically Implanting Transmitters into Fish

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Ricardo W.; Markillie, Lye Meng; Colotelo, Alison HA; Gay, Marybeth E.; Woodley, Christa M.; Brown, Richard S.

    2013-02-28

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelom of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When several fish are implanted consecutively for large telemetry studies, it is common for surgical tools to be sterilized or, at minimum, disinfected between each use so that pathogens that may be present are not spread among fish. However, autoclaving tools can take a long period of time, and chemical sterilants or disinfectants can be harmful to both humans and fish and have varied effectiveness. Ultraviolet (UV) radiation is commonly used to disinfect water in aquaculture facilities. However, this technology has not been widely used to sterilize tools for surgical implantation of transmitters in fish. To determine its efficacy for this application, Pacific Northwest National Laboratory researchers used UV radiation to disinfect surgical tools (i.e., forceps, needle holder, stab scalpel, and suture) that were exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. These organisms included Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica. Surgical tools were exposed to the bacteria by dipping them into a confluent suspension of three varying concentrations (i.e., low, medium, high). After exposure to the bacterial culture, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then exposed for three different time periods—2, 5, or 15 min. S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV light exposures of 5 and 15 min were effective at killing all four organisms. UV light was also effective at killing Geobacillus stearothermophilus, the organism used as a biological indicator to verify effectiveness of steam sterilizers. These

  2. Setting the sterilization dose for a cotton-based product family using a knowledge of the distribution of radiation resistances

    Science.gov (United States)

    Yan, Aoshuang; Wang, Ailian; Zhai, Ying; Chen, Ben; Lim, Boon

    2002-03-01

    In setting a sterilization dose for a cotton-based product family that has failed the verification experiment of Method 1 given in ISO 11137, a study has been carried out to gain a knowledge of the distribution of radiation resistances of contaminating microorganisms. Overall, 155 organisms were isolated from a total of 11,000 organisms present on 100 g of products. D10 values of the isolates fall within 0.8-3.8 kGy. The derived distribution of radiation resistances can be considered as an evidence to support the use of sterilization doses given in Table B1 of ISO 11137 for different bioburden levels.

  3. Radiation induced sterility to control tsetse flies : the effect of ionising radiation and hybridisation on tsetse biology and the use of the sterile insect technique in integrated tsetse control

    NARCIS (Netherlands)

    Vreysen, M.J.B.

    1995-01-01

    The induction of dominant lethal mutations by exposing tsetse flies as pupae or adult insects to ionising radiation and the use of hybrid sterility resulting from crosses of closely related tsetse species or subspecies, are potential methods of genetic control of tsetse flies. In this

  4. Trend of radiation sterilization business in Japan and how to develop new applications

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T. E-mail: Tomio_Takahashi@jisco-hq.co.jp

    2004-10-01

    There are thick and high barriers against promotion of radiation processing, especially in Japan. These are regulation, material, cost and consumer's emotion. Release of validation guidelines for sterilization from the Japanese government in 1997 based on ISO11137 and ISO9001 made it easy for us to use irradiation. Most remarkable regulation impacting on a switch to irradiation from ethylene oxide (EtO) was pollutant release and transfer registers (PRTR) proclaimed in 2001 and enforced in 2002. EtO gas is included in the list of poisonous materials. In addition, the government published brochures and distributed them to all manufacturers to improve the employee's health and to keep work area clean. These governmental movements are pushing EtO users to decide if they will continue or give up EtO. To enhance irradiation business, both regulation and de-regulation are important factors.

  5. Feasibility Study on Sterilization of Badge using Radiation and Cultivation by Nano-bubble Water for Matsutake Mushroom Cultivation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Inha

    2013-12-15

    This report on the 'Sterilization of Badge using Radiation and Cultivation by Nano-bubble Water for Matsutake Mushroom Cultivation' is belonged to the final report on the preliminary study of the first subject in 2013 for civilian project. This was complimented on the responsible of the Korea Atomic Energy Research Institute for 1{sup st} of June 2013 to 30{sup th} of November 2013. We are going to make sterilization the badge using the gamma ray and supplying the oxygen by nano-bubble oxygen rich water for cultivating the Matsutake Mushroom, instead of the conventional process of sterilization of the badge by hot steam over 120 .deg. C consuming over 8 hours and expensive ventilation system for supplying the fresh air for delivering the oxygen.

  6. Effects of gamma irradiation on osteoinduction associated with demineralized bone matrix.

    Science.gov (United States)

    Han, Bo; Yang, Zhi; Nimni, Marcel

    2008-01-01

    Gamma irradiation is frequently used to sterilize implanted devices but has limitations when used on biologically active materials and composites. In this study, we have evaluated the changes of biological activity of demineralized bone matrix (DBM) in the dry state and in the presence of aqueous and non-aqueous carriers while exposed to various levels of ionizing radiation. The activity of DBM in the dry state remains relatively stable with only a small loss of activity. Composites of DBM with a carrier such as lecithin, to which no water has been added, lose activity at approximately the same rate as DBM in the anhydrous form. In composites that contain water, the loss of activity occurs even at much lower levels of radiation exposure. Gamma irradiation does not change cell attachment to the DBM matrix but has an influence on both stem cell and osteoprecursor cell proliferation rates. Because of the limitations imposed by radiation, it seems most practical to handle DBM aseptically throughout the procedures of compositing pastes, putties, or suspensions, and only if necessary exposing the inert excipients to radiation sterilization prior to mixing. (c) 2007 Orthopaedic Research Society.

  7. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    De Guzman, Zenaida M. [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Cervancia, Cleofas R. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines, Los Banos, Laguna (Philippines); Dimasuay, Kris Genelyn B.; Tolentino, Mitos M.; Abrera, Gina B.; Cobar, Ma. Lucia C. [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Fajardo, Alejandro C.; Sabino, Noel G.; Manila-Fajardo, Analinda C. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines, Los Banos, Laguna (Philippines); Feliciano, Chitho P., E-mail: cpfeliciano@pnri.dost.gov.ph [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City (Philippines)

    2011-10-15

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a {sup 60}Co source. Surviving spores were counted and used to estimate the decimal reduction (D{sub 10}) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10{sup 5}-9x10{sup 3} spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D{sub min}) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to {gamma}-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials. - Highlights: > We characterized Paenibacillus larvae and determined its radiation sensitivity. > We investigated the effectiveness of gamma rays in inactivating P. larvae. > Gamma radiation inactivates P. larvae. > 15 kGy is effective for the sterilization of P. larvae-infected hives. > Irradiation produces no visible changes in the hives' body, waxes and frames.

  8. EXPERIMENTAL ESTIMATION OF THE DEMINERALIZED BONE ALLOGRAFTS MADE BY TECHNOLOGY OF CITO

    Directory of Open Access Journals (Sweden)

    Yu. B. Yurasova

    2010-01-01

    Full Text Available Research is devoted an experimental estimation of osteoinductive properties of demineralized bone implants (DBA made on technology CITO with use of lyophilization and radiating sterilization by stream of fast electrons. As experimental animals, white rats on ectopic osteogenesis model for a period of 40 days and rabbits to which DBA implanted into defect of the jaw with terms of experiment 10, 20, 30, 60 and 90 days have been chosen. Results of morphological researches testified to absence of toxicity, presence of high indicators of biointegration and osteoinductance studied DBA. The offered technology of processing of a bone tissue allows to keep biological activity of tissues and to receive biological materials with the expressed plastic properties. Obtained among other data were the bases for the decision of use of these materials in clinic of different bone pathologies.

  9. Gamma radiation effects in packaging for sterilization of health products and their constituents paper and plastic film

    Science.gov (United States)

    B. G. Porto, Karina Meschini; Napolitano, Celia Marina; Borrely, Sueli Ivone

    2018-01-01

    The integrity of materials containing packaging (natural or synthetic polymers) is essential to keep the aseptic condition of commercialized products (health care products, food and pharmaceuticals). The objective of this paper was to study gamma radiation effects (25 kGy, 40 kGy and 50 kGy) on the main properties of paper and multilayer films (polyester and polyethylene). Paper and multilayer films are components of packaging (pouches) for radiation sterilization containing medical equipment or products. Paper was the more radiation sensitive among the studied materials and radiation effects were more pronounced at brightness, pH, tearing resistance, bursting strength and tensile strength. Concerning plastic film, no pinholes were induced by radiation and the effects on the tensile strength were not significant. Although the seal strength packaging (pouches) decreased according to increasing dose, the sealing integrity was preserved.

  10. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays.

    Science.gov (United States)

    De Guzman, Zenaida M; Cervancia, Cleofas R; Dimasuay, Kris Genelyn B; Tolentino, Mitos M; Abrera, Gina B; Cobar, Ma Lucia C; Fajardo, Alejandro C; Sabino, Noel G; Manila-Fajardo, Analinda C; Feliciano, Chitho P

    2011-10-01

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a ⁶⁰Co source. Surviving spores were counted and used to estimate the decimal reduction (D₁₀) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10⁵- 9 × 10³ spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D(min)) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to γ-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Materials of 4. Spring School of Radiation Sterilization of Medical Materials, Grafts, Pharmaceutics and Cosmetics; Materialy 4. Wiosennej Szkoly Sterylizacji Radiacyjnej Sprzetu Medycznego, Przeszczepow, Farmaceutykow i Kosmetykow

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The state of art in well developed in Poland radiation technologies has been done. The legal and economical aspects have been discussed for radiation sterilization of health care products, drugs, biomaterials and grafts. Industrial plants and radiation procedures have been described. The perspectives for further development and other industrial applications have been also discussed.

  12. Freeze-dried bone allografts sterilized with gamma radiation and the clinical use in harelip

    Energy Technology Data Exchange (ETDEWEB)

    Luna Z, D.; Reyes F, M. L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Diaz M, I.; Cruz A, L. C. [Centro Estatal de Trasplantes del Estado de Mexico, Pablo Sidar No. 602, Col. Universidad, Toluca 50130, Estado de Mexico (Mexico); Vazquez R, M. A., E-mail: daniel.luna@inin.gob.m [Centro de Especialidades Odontologicas, Instituto Materno Infantil del Estado de Mexico, Paseo Colon esquina Felipe Angeles s/n, Col. Villa Hogar, Toluca 50170, Estado de Mexico (Mexico)

    2010-10-15

    Bone for transplant is part of the musculoskeletal tissue join with fascia lat, tendon, ligament and cartilage. Bone is formed by cells (osteocytes, osteoblasts and osteoclasts) and extracellular matrix formed mainly by collagen and hydroxyapatite, which gives strength and elasticity to the bone. The bone function in the body is to move, support, organs protection, production of blood cells and store minerals. The musculoskeletal tissue is processed in specialized tissue banks using gamma radiation of cobalt-60 for sterilization at 25 kGy doses at very low temperature or at room temperature, getting tissues with high quality for clinical applications in injured patients. The process of the bone for transplants varies depend on the size and the surgeon likes, nevertheless in general the large ones are preserved at low temperature (-80 C), meanwhile the short ones are freeze-dried preserved. The musculoskeletal diseases represent the most common physical incapacity, which affect million of people around the world. Due to the human body has 206 bones, during a bone injury each bone can be replaced or repaired with several devices, in general the surgeon goes to a specialized tissue banks, to get the bone, due to the high bone quantity on the body and the number of bone injuries and diseases, the bone is the most transplanted around the world only behind the blood. The bone can be processed in several sizes and shapes, one of these is bone powder from allograft, which is used over all for bone filling, this can be take advantage for cleft lip and palate defects, which is a birth defect, this can affect the way the child's face looks, it can also lead to problems with eating, talking and ear infections. The description of the bone powder process is presented and the clinical use of this powder in several pediatric patients for cleft lip and palate defects is described. (Author)

  13. Converting from EtO to radiation sterilization: educating the medical supply industry

    Energy Technology Data Exchange (ETDEWEB)

    Bedward, D.A.; Brinston, R.M.; Kotler, J. [Nordion International Inc., Ontario (Canada)

    1995-10-01

    This paper examines some relevant factors influencing the conversion from ethylene oxide sterilization to gamma sterilization. Marketing tactics to promote and stimulate this activity are reviewed. TEAM GAMMA, an educational vehicle developed by Norion International Inc., is described from the concept acceptance to the very positive results obtained. The structure of this multi disciplinary team of consultants is described. Topics presented by this team include sterilization basics, material compatability, device design manufacturing and other aspects of the sterilization process. It is concluded that assisting in the education of the medical device manufacturers regarding the conversion from EtO to gamma processing provides payback for Nordion and the gamma processing industry. This assessment is based on the results of the ten seminars presented to date. (author).

  14. Mechanical strength of cortical allografts with gamma radiation versus ethylene oxide sterilization.

    Science.gov (United States)

    Zhou, Zongke; Qin, Tingwu; Yang, Jing; Shen, Bin; Kang, Pengde; Peil, Fuxing

    2011-10-01

    We investigated the effects of gamma irradiation versus ethylene oxide (ETO) sterilization on the mechanical strength of cortical bone grafts. Tibias were collected from cadavers of mature goats. Sixty test specimens were randomized into four groups: fresh (no processing), frozen (freezing at -70 degrees C), gamma-irradiated, and ETO-sterilized specimens. Torsion, three-point bending, and compression testing were separately performed with a material testing machine. Parameters studied included maximum stress, strain, deflection, extension, load, shear modulus, and E-modulus. Compared with findings for the fresh specimens, findings were as follows for gamma-irradiated specimens: maximal shear modulus, reduced by 48%; shear stress, by 55%; deflection, by 71%; bending stress, by 51%; bending strain, by 74%; extension, by 60%; and compression strain, by 50%. However, there were no reductions in those parameters for the frozen specimens or the ETO-sterilized specimens. These findings confirm that shear, bending, and compression strength of cortical allografts are weakened by gamma irradiation at room temperature. To maintain optimum mechanical properties, ETO sterilization of allografts is better than gamma sterilization, especially for cortical bone, because it is usually used in load-bearing settings.

  15. Damage of office supply, personal use items, and over-the-counter medical devices after sterilization by ethylene oxide gas, electron beam, and gamma radiation.

    Science.gov (United States)

    Lucas, Anne D; Merritt, Katharine; Hitchins, Victoria M

    2004-01-01

    After letters containing Bacillus anthracis spores entered the U.S. mail in 2001, a problem emerged regarding how to decontaminate the letters, packages, and personal items in offices that received these letters. The effects of three sterilization methods (i.e. ethylene oxide gas [EO], electron beam [e-beam] radiation, and gamma radiation) were evaluated for a variety of office supply and equipment, personal use items, and over-the-counter medical devices. No single sterilization method was suitable for all items that could be mailed or found in an office. Damage or discoloration was evident for some items by each sterilization method. There were changes in the color of certain items, such as some of the packaging material, some pacifiers, some of the fabrics, and the nylon stockings after e-beam and gamma radiation. Both e-beam and gamma radiation damaged all film samples. Following EO sterilization and normal aeration, there were a number of samples with high (above 250 microg/g) levels of EO and samples with detectable ethylene chlorohydrin levels. The data would suggest that certain items exposed to EO sterilization must be further aerated prior to use, or discarded. Generic descriptions of products (such as plastics) or grouping of items (such as condoms) were not sufficient to predict what is safe in terms of EO residual levels remaining on an item. Successful decontamination of a wide variety of items will require careful selection of different sterilization methods.

  16. Hospital waste sterilization: A technical and economic comparison between radiation and microwaves treatments

    Science.gov (United States)

    Tata, A.; Beone, F.

    1995-09-01

    Hospital waste (HW) disposal is becoming a problem of increasing importance in almost all industrially advanced countries. In Italy the yearly hospital waste production is about 250,000 tons and only 60,000 tons are treated by incineration at present time. As by a recent Italian law a meaningful percentage of HW (50 to 60%), corresponding to food residuals, plastics, paper, various organic materials, etc., could be landfilled as municipal refuses if preliminarily submitted to a suitable sterilization treatment. Under this perspective, sterilization/sanitation techniques represent now a technically and commercially viable alternative to HW thermal destruction that, besides, is more and more socially and politically less accepted. Electron Beam (EB) and Microwave (MW) treatments are two of the most interesting and emerging HW sterilization techniques, and, based on engineering real data, a technical and economic comparison is carried out, focusing vantages and limits of each process.

  17. Application evaluation of a polydimethylsiloxane low-viscosity for cryopreservation and radiation sterilization of human cadaveric vascular allografts.

    Directory of Open Access Journals (Sweden)

    Lauk-Dubitsky S.E.

    2016-12-01

    Full Text Available Aim: to investigate potential cryo- and radioprotective properties of a polydimethylsiloxane of low viscosity to provide safe and reliable cryopreservation and radiation sterilization of human cadaveric vascular allografts. Material and methods. A consecutive experimental set-up was carried out to establish polydimethylsiloxane (further — PDMS protective endocellular properties. For this purpose a high-densitymesenchymal stem cells suspension was cryopreserved with 10% DMSO solution; PDMS exocellular protective properties were assessed by cyclic cryoconservation of ^femoral artery segments, while PDMS potential radioprotectiveproperties were assessed by gamma irradiation — induced sterilization of 3 cryopreserved femoral artery segments with gross length about 3cm, and for control grafts a slightly changed protocol with glycerin was used. In this study the dynamic viscosity of all cryopreserved vessels was analyzed with using specially designed experimental device, also electron scanning microscopy with lanthanide cells staining and routine hematoxylin — eosin cell staining were applied. Results. We have demonstrated a prominentexocellular protective effect of PDMS confirmed by a SEM and histological results, and also its mediated radioprotective effect, in particular because of its safer preliminary cryopreservation procedure. Conclusion. Use of PDMS for a cryopreservation and gamma sterilization showed its rationality, however requires further modification of protocols and additional researches.

  18. Costs of validation of sterilization methods: Gamma radiation versus ethylene oxide

    NARCIS (Netherlands)

    Geertsma RE; Dorpema JW; Asten JAAM van; LGM

    1995-01-01

    The interpretation of the European Standards for validation of sterilization processes by manufacturers of medical devices in practice is not done in a uniform way. In order to determine whether cost aspects of the validation procedure might play a significant role in management decisions regarding

  19. Proceedings of 3. autumn school of radiation sterilization of medical utensils and grafts; 3. jesiennea szkola sterylizacji radiacyjnej sprzetu medycznego i przeszczepow

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Polish experience and review of worldwide development of radiation techniques and technologies have been presented and discussed in the field of radiation sterilization of medical supplies and grafts as well as for food processing. These problems have found now in Poland industrial or pilot plant solutions. Also some technologies connected with medical utensils production from with polymeric material resistant for radiation have been developed in Poland.

  20. Sterile neutrinos in cosmology

    Science.gov (United States)

    Abazajian, Kevork N.

    2017-11-01

    Sterile neutrinos are natural extensions to the standard model of particle physics in neutrino mass generation mechanisms. If they are relatively light, less than approximately 10 keV, they can alter cosmology significantly, from the early Universe to the matter and radiation energy density today. Here, we review the cosmological role such light sterile neutrinos can play from the early Universe, including production of keV-scale sterile neutrinos as dark matter candidates, and dynamics of light eV-scale sterile neutrinos during the weakly-coupled active neutrino era. We review proposed signatures of light sterile neutrinos in cosmic microwave background and large scale structure data. We also discuss keV-scale sterile neutrino dark matter decay signatures in X-ray observations, including recent candidate ∼3.5 keV X-ray line detections consistent with the decay of a ∼7 keV sterile neutrino dark matter particle.

  1. Gamma sterilization of a semi-solid poly(ortho ester) designed for controlled drug delivery--validation and radiation effects.

    Science.gov (United States)

    Merkli, A; Heller, J; Tabatabay, C; Gurny, R

    1994-10-01

    Radiation sterilization is becoming increasingly popular for the sterilization of many pharmaceutical products. Although this technique is not limited to the sterilization of polymers, it is probably the most suitable method for such materials. This method however suffers several drawbacks. The sterilization of a product must lead to a safety level of 10(-6), i.e. one chance in a million to find a contaminated sample. In many cases, this assurance of sterility can be achieved by using a uniform treatment dose of 2.5 Mrad, recommended by the pharmacopeia. We investigated the possibility of using doses of radiation inferior to 2.5 Mrad to sterilize a semi-solid poly(ortho ester) (POE) developed for use as carrier in controlled drug delivery. After determination of the initial bioburden, the polymer was intentionally contaminated with the bioindicator Bacillus pumilus E 601. Following exposure to gamma irradiation, the D10 value of the radio resistant bioindicator was determined. Using the initial contamination value, the reduction factor D10 and the safety level, it is possible to calculate an optimal sterilizing dose for POE. All polymers are affected by ionizing radiation and the amount of radiation which produces a significant change in properties may vary from one polymer to the other. A molecular weight and dynamic viscosity decrease resulting from backbone cleavage was observed for this POE at a dose lower than 2.0 Mrad. Evaluation of the structure using 1H-NMR, 13C-NMR and IR analysis shows that for doses higher than 2.0 Mrad, another degredation process takes place.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Sterilization of biological tissues with ionizing radiation; Esterilizacion de tejidos biologicos con radiacion ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Reyes F, M.L.; Martinez P, M.E.; Luna Z, D. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    On June 1994, the National Institute of Nuclear Research (ININ) and the South Central Hospital for High Specialty of PEMEX (HCSAE) began a joint work with the finality to obtain radio sterilized amniotic membranes for to be used as cover (biological bandage) in burnt patients. Subsequently the Chemistry Faculty of UNAM and the National Institute of Cardiology began to collaborate this last with interest on cardiac valves for graft. Starting from 1997, the International Atomic Energy Agency (IAEA) supports this project (MEX/7/008) whose main objective is to set up the basis to establish in Mexico a Radio sterilized Tissue Bank (amniotic membranes, skin, bones, tendons, cardiac valves, etc.) to be used with therapeutic purposes (grafts). The IAEA support has consisted in the equipment acquisition which is fundamental for the Tissue Bank performance such as an experimental irradiator, laminar flow bell, lyophilizer, vacuum sealer and special knives for tissues. Also visits to Mexico of experts have been authorized with the aim of advising to the personnel which participate in the project and scientific visits of this personnel to another tissue banks (Sri Lanka and Argentine). The establishment in Mexico of a Tissue bank will be a great benefit because it will have availability of distinct tissues for grafts and it will reduce the synthetic materials importation which is very expensive. (Author)

  3. Effect of gamma radiation on Phenoloxidase pathway, antioxidant defense mechanism in Helicoverpa armigera (Lepidoptera: Noctuidae) and its implication in inherited sterility towards pest suppression.

    Science.gov (United States)

    Sachdev, Bindiya; Zarin, Mahtab; Khan, Zubeda; Malhotra, Pawan; Seth, Rakesh Kumar; Bhatnagar, Raj K

    2014-01-01

    To investigate age-correlated radiosensitivity in highly radioresistant lepidopteran pest, Helicoverpa armigera, upon exposure to ionizing radiation and to examine the irradiation impact on stress-molecular responses in F1 (first-filial) progeny of irradiated (100 Gy) male moths in relation to its reproductive behavior. Efficacy of sub-lethal gamma radiation was evaluated on two markedly apart ontogenic stages, neonates and adult moths. Differential growth, reproductive behavior and stress-indicating molecular responses were examined upto F1 progeny of sub-sterilized moths. Free-radical scavenging enzymes, superoxide dismutase (SOD), catalase (CAT) and Phenoloxidase cascade enzymes, pro-phenoloxidase (PPO), its activating enzyme (PPAE) were studied in irradiated and irradiated plus microbial challenge regimen (dual-stress) by Real-time RT-PCR (reverse-transcription-polymerase-chain-reaction). An inverse correlation of radiosensitivity with developmental age of insect was observed. F1 sterility was higher than parent sterility. F1 progeny exhibited protraction in development and decreased survival upon irradiation. Sex ratio in F1 progeny was skewed towards males. PPO, PPAE, SOD and CAT transcripts were downregulated upon neonate irradiation resulting in enhanced vulnerability of larvae to incidental microbial challenge. These transcripts were upregulated in F1 progeny of sub-sterilized male moths (100 Gy) upon dual-stress. Irradiation impact on stress-indicating molecular responses in F1 progeny is correlated with its reproductive performance. These observations will permit defining regimen having pragmatic viability of 'F1 sterility technique' for pest suppression. Gamma dose of 100 Gy would ensure balance between induced sterility of males and their field competitiveness. These parameters would facilitate integration of biocontrol strategy with parabiological 'Sterile Insect Release Technique'.

  4. Effects of gamma ray radiation sterilization on chemical components of soy sauce

    Energy Technology Data Exchange (ETDEWEB)

    Yin Daochuan; Zou Zuren; Liu Zongtiao; Fang Jie (Jiangsu Academy of Agricultural Sciences, Nanjing (China). Inst. of Application of Atomic Energy in Agriculture)

    1989-01-01

    Soy sauce was treated with {gamma}-ray radiation. The results indicated that there were no significant differences in total acids, total nitrogen, reduced-sugar, sodium chloride and 17 free amino acids between the treated and untreated soy sauce. Specialists from some factories tested the samples and no obvious changes in colour and lustre, flavour, sweet smell and liquid appearance could be identified after the treatment. (author).

  5. Effects of gamma ray radiation sterilization on chemical components of soy sauce

    Science.gov (United States)

    Daochuan, Yin; Zuren, Zou; Zongtiao, Liu; Jie, Fang

    Soy sauce was treated with γ-ray radiation. The results indicated that there were no significant differences in total acids, total nitrogen, reduced-sugar, sodium chloride and 17 free amino acids between the treated and untreated soy sauce. Specialists from some factories tested the samples and no obvious changes in colour and lustre, flavour, sweet smell and liquid appearance could be identified after the treatment.

  6. The effect of ionizing radiation on biocompatible polymers: From sterilization to radiolysis and hydrogel formation

    Czech Academy of Sciences Publication Activity Database

    Sedláček, Ondřej; Kučka, Jan; Monnery, B. D.; Šlouf, Miroslav; Vetrík, Miroslav; Hoogenboom, R.; Hrubý, Martin

    2017-01-01

    Roč. 137, March (2017), s. 1-10 ISSN 0141-3910 R&D Projects: GA ČR(CZ) GA13-08336S; GA MZd(CZ) NV15-25781A; GA MZd(CZ) NV16-30544A; GA MŠk(CZ) LH14079; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : biocompatible polymers * radiation crosslinking * polymer radiotherapeutics Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.386, year: 2016

  7. Morphological analysis of amnion stored in glycerol sterilized with different doses of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Fernando Augusto N.; Santin, Stefany P.; Martino Junior, Antonio C.; Machado, Luci Diva B.; Mathor, Monica B., E-mail: fernandonevessoares@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (CTR/IPEN/CNEN-SP), Sao Paulo, RJ (Brazil). Centro de Tecnologia das Radiacoes

    2013-07-01

    The amniotic membrane (AM) is the innermost layer of the fetal membranes (placenta), widely used in transplantation being a tissue that combines anti-inflammatory, antimicrobial and antifibrotic, and limited immunogenicity. The tissue can be used a bandage biological for treatment of burns and skin wounds, chronic ulcers, reconstructions from different body areas, including ophthalmic repairs. In the last decades the amniotic membrane has been used widely also as a carrier substrate to transfer tissues cultured 'in vitro'. The use of fresh membrane has some limitations, the main ones are being necessary your quick use and the inability to obtain full security for certain infections. Other types of preservation require a processing thereof. The radiosterilization is an alternative for ensuring quality and safety of tissues used in transplants, and other clinical applications in order to minimize the risk of contamination of the receptor tissue. Therefore, the objective of this study was to test various doses of radiation using two sources of ionizing radiation: the cobalt-60 irradiator Gamma and Electron Beam Accelerator (E.B.). A tissue analysis was done by visual and tactile qualitative analysis, semi-quantitative (solid colorimetry) and light microscopy to observe morphological and physic-chemical changes after the irradiation of AM preserved in glycerol, comparing the results obtained with the sample not irradiated. It was noted that at higher doses, for both radiation sources, irradiated membranes suffered greater color change, becoming yellowish and thereby reducing their initial malleability. (author)

  8. Effect of UV radiation on a thermostable superoxide dismutase purified from a thermophilic bacterium isolated from a sterilization drying oven.

    Science.gov (United States)

    Monsalves, María T; Amenábar, Maximiliano J; Ollivet-Besson, Gabriela P; Blamey, Jenny M

    2013-07-01

    A thermostable superoxide dismutase from a thermophilic bacterium, called Geobacillus wiegeli (GWE1), isolated from the interior of a sterilization drying oven, was purified by anion-exchange and molecular size-exclusion liquid chromatography. On the basis of SDS-PAGE, the purified enzyme was found to be homogeneous and showed an estimated subunit molecular mass of 23.9 kDa. The holoenzyme is a homotetramer of 97.3 kDa. Superoxide dismutase exhibited maximal activity at pH 8.5 and at temperature around 60 ºC. The enzyme was thermostable maintaining 50% of its activity even after 4.5 hours incubation at 60 ºC and more than 70% of its activity after 30 min at 80 ºC. When the microorganism was irradiated with UVA, an increase in the specific activity of superoxide dismutase was observed which was correlated with decreasing levels of anion superoxide, indicating the direct involvement of this enzyme in the capture of reactive oxygen species. This study reports the effects of UV radiation on a superoxide dismutase from a thermophilic bacterium isolated from an anthropogenic environment.

  9. The effect of gamma irradiation on the osteoinductivity of demineralized human bone allograft.

    Directory of Open Access Journals (Sweden)

    Babak Arjmand

    2014-03-01

    Full Text Available The gamma irradiation has been used for end sterilization of allograft bones and its effects with a 25 kGy dosage on the osteoinductive properties of demineralized bone allograft powder was studied. This work carried out using an experimental method in an animal model. In this study the demineralized bone allograft powder which had been sterilized and prepared with gamma irradiation in a 25 kGy dosage in 18 hours, was used as a study group and the demineralized bone allograft powder which had been prepared aseptically was used as the reference group. 30 mg of bone powder from each group were implanted into right and left paravertebral muscles of eighteen rats, separately. After four weeks, the implanted samples were harvested with a 0.5 cm border and then the osteoinductivity of implants in two groups were compared with histopathologic studies. In 94.4% of the reference samples a new bone formation was observed. In the study group, this difference was observed only in 27.7% of samples (P<0.002. It appears that using gamma irradiation may lead to a reduction in osteoinduction properties of demineralized bone allograft powder.

  10. Reversible Sterilization

    Science.gov (United States)

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  11. RATE AND MECHANISM OF ENAMEL DEMINERALIZATION INSITU

    NARCIS (Netherlands)

    ARENDS, J; CHRISTOFFERSEN, J; CHRISTOFFERSEN, MR; OGAARD, B; DIJKMAN, AG; JONGEBLOED, WL

    1992-01-01

    In this paper, data are presented on the in situ demineralization of human enamel as a function of the demineralization period. To quantify the mineral loss parameters versus time, it is important to obtain information on the kinetics, and thus on the mechanism of dental caries. The results show

  12. Sterilization System

    Science.gov (United States)

    1990-01-01

    Cox Sterile Products, Inc.'s Rapid Heat Transfer Sterilizer employs a heat exchange process that induces rapid air movement; the air becomes the heat transfer medium, maintaining a uniform temperature of 375 degrees Fahrenheit. It features pushbutton controls for three timing cycles for different instrument loads, a six-minute cycle for standard unpackaged instruments, eight minutes for certain specialized dental/medical instruments and 12 minutes for packaged instruments which can then be stored in a drawer in sterile condition. System will stay at 375 degrees all day. Continuous operation is not expensive because of the sterilizer's very low power requirements.

  13. Qualitative and semi quantitative analysis in the healing area of athymic nude mice skin engrafted with human skin sterilized with gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Jurandir Tomaz de; Bringel, Fabiana; Alves, Nelson Mendes; Antebi, Uri; Funari, Ana Paula; Mathor, Monica B., E-mail: tomaz_ju@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    In recent decades there has been a great interest in the radio-sterilized grafts for human skin grafts. This tissue is taken from a cadaver or multi-organ donor and samples are processed and stored in glycerol at concentrations above 85%. Although this procedure is carried out under aseptic conditions, after the final packaging one can sterilize the tissues with ionizing radiation in order to increase the safety level of sterility. The purpose of this study was to evaluate the behavior of the healing repair process that occurs between the graft and the skin of athymic NUDE mice. The samples of human skin treated with glycerol were divided into three groups: the control group 1 (non-irradiated), irradiated group 2 at 25 kGy and irradiated group 3, at 50 kGy. These tissues were grafted onto athymic NUDE mice which were sacrificed after 3, 7 and 21 days. After the sacrifice, part of the back fur of the animals containing human skin graft was removed with hematoxylin and eosin (H/E). The histological sections were analyzed for the integrity of tissue, presence and location of keratinocytes, fibroblasts, defense cells and blood vessels. Thus it was examined whether over time the graft was incorporated into the body or if there was a process of healing by secondary intention. (author)

  14. Applied radiation physics: The use of x-rays for the structural characterization of aqueous emulsions and the development of new insect sterilization protocols

    Science.gov (United States)

    Brar, Ramaninder K.

    significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. To improve mosquito SIT, we have developed new radiation protocols for insect sterilization using long wavelength x-rays. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males' longevity as well as on the efficacy of sterilization while employing a substantially lower dose.

  15. Can demineralized enamel surfaces be bonded safely?

    Science.gov (United States)

    Akin, Mehmet; Baka, Zeliha Muge; Ileri, Zehra; Basciftci, Faruk Ayhan

    2014-05-01

    To evaluate and compare the effects of enamel demineralization, microabrasion therapy and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application on the shear bond strength (SBS) of orthodontic brackets bonded to enamel surfaces and enamel color. Eighty freshly extracted human maxillary premolar teeth were allocated to one of the four groups. Brackets were bonded directly to non-demineralized enamel surfaces in Group I (control group), directly to the demineralized enamel surfaces in Group II, to demineralized enamel surfaces after CPP-ACP application in Group III and to demineralized enamel surfaces after microabrasion therapy in Group IV. The samples were stored in water for 24 h at 37°C and then underwent thermocycling. The SBS in megapascals (MPa) was determined by a shear test with 0.5 mm/min crosshead speed and failure types were classified with modified adhesive remnant index scores. The data were analyzed with one-way analyses of variance (ANOVA), Tukey and chi-square tests at the α = 0.05 level. Significant differences were found among the four groups (F = 21.57, p microabrasion therapy and CPP-ACP application affected enamel color significantly. CPP-ACP application and microabrasion therapy are able to increase the decreased SBS of orthodontic brackets because of enamel demineralization.

  16. Raman spectral markers of collagen denaturation and hydration in human cortical bone tissue are affected by radiation sterilization and high cycle fatigue damage.

    Science.gov (United States)

    Flanagan, Christopher D; Unal, Mustafa; Akkus, Ozan; Rimnac, Clare M

    2017-11-01

    Thermal denaturation and monotonic mechanical damage alter the organic and water-related compartments of cortical bone. These changes can be detected using Raman spectroscopy. However, less is known regarding Raman sensitivity to detect the effects of cyclic fatigue damage and allograft sterilization doses of gamma radiation. To determine if Raman spectroscopic biomarkers of collagen denaturation and hydration are sensitive to the effects of (a) high cycle fatigue damage and (b) 25kGy irradiation. Unirradiated and gamma-radiation sterilized human cortical bone specimens previously tested in vitro under high-cycle (> 100,000 cycles) fatigue conditions at 15MPa, 25MPa, 35MPa, 45MPa, and 55MPa cyclic stress levels were studied. Cortical bone Raman spectral profiles from wavenumber ranges of 800-1750cm-1 and 2700-3800cm-1 were obtained and compared from: a) non-fatigue vs fatigue fracture sites and b) radiated vs. unirradiated states. Raman biomarker ratios 1670/1640 and 3220/2949, which reflect collagen denaturation and organic matrix (mainly collagen)-bound water, respectively, were assessed. One- and two-way ANOVA analyses were utilized to identify differences between groups along with interaction effects between cyclic fatigue and radiation-induced damage. Cyclic fatigue damage resulted in increases in collagen denaturation (1670/1640: 1.517 ± 0.043 vs 1.579 ± 0.021, p denaturation (r = 0.514, p denaturation was sensitive to cyclic fatigue damage but not 25kGy irradiation. Collagen denaturation was correlated with organic matrix-bound water, suggesting that denaturation of collagen to gelatinous form may expose more binding sites to water by unwinding the triple alpha chains. This research may eventually be useful to help identify allograft quality and more appropriately match donors to recipients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Optimized demineralization of human cancellous bone by application of a vacuum.

    Science.gov (United States)

    Eagle, Mark J; Rooney, Paul; Kearney, John N

    2015-07-01

    Human demineralized bone matrix derived from cortical bone is used by surgeons due to its ability to promote bone formation. There is also a need for shaped demineralized bone matrices made from cancellous bone, where the properties of the material allow its insertion into defects, therefore acting as a void filler and scaffold onto which new bone can form. In this study, we report that demineralized bone sponges were prepared by dissecting and cutting knee bone into cancellous bone cubes of 1 cm(3) . These cubes were then taken through a series of warm water washes, some with sonication, centrifugation, and two decontamination chemical washes. The cubes were optimally demineralized into sponges with 0.5N hydrochloric acid under vacuum with constant pH measurement. Demineralization was confirmed by quantitative measurement of calcium and qualitatively by compression. The sponges were freeze dried before terminal sterilisation with a target dose of 25 kGy gamma radiation whilst frozen. Samples of the sponges were histologically examined for calcium and collagen and also tested for osteoinductivity. Data showed well defined collagen staining in the sponges, with little residual calcium. Sponges from two out of three donors demonstrated osteoinductivity when implanted into the muscle of an athymic mouse. © 2014 Wiley Periodicals, Inc.

  18. Sterilization by Laparoscopy

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ035 CONTRACEPTION Sterilization by Laparoscopy • What is sterilization? • What is the sterilization procedure for women? • How is tubal sterilization done? • How effective is laparoscopic sterilization in ...

  19. Application of electron beam radiation for peat sterilization and suppression of microbe contaminants; Aplicacao da radiacao por feixe de eletrons como agente esterilizante de microorganismos em substrato turfoso

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, David

    2006-07-01

    Inoculation of root nodule bacteria into legume seeds such as soybean [Glycine max. (L.)], common bean (Phaseolus vulgaris L.) and forage pasture has been effective and convenient as this simple procedure may introduce effective strains of Bradyrhizobium/Rhizobium into agricultural soils without a past history of successful cropping systems with the legume hosts. Peat-based substrates previously sterilized have been used for decades as bacteria carrier, protecting them from the prevailing harsh conditions in tropical soils and ensuring their survival with nutrient and protection against the soil antagonists. The Brazilian Government requires that all peat-based substrates must be gamma-sterilized from a cobalt-60 ({sup 60}Co) source, prior the introduction of the root nodule bacteria into the package. The recommendation is for a dose up to 50 kGy for an effective suppression of pathogens and saprophytes, in order to avoid competition among the substrate microbiota. Recently, the use of the electron beam (EB) accelerator has shown to be a new alternative for peat pre-sterilization, as this technique may promote reactive free-radicals which are efficient to suppress microbial contaminants. This fast technology is considered more environment and ecology friendly-sound than gamma radiation ({gamma}). The disadvantage of not reaching higher depth than gamma rays from {sup 60}Co must be considered, and attempts of optimizing the technique are crucial. This study compared both methods by using increasing rates of radiation by {sup 60}Co by the EB method - O, 10, 20, 30, 40 e 50 kGy in a commercial peat used for inoculants. Experimental data from days 7, 14, 21 and 28 days (growth period) and 150, 180 and 210 days (storage period) indicated high numbers of the strain Rhizobium tropici CM-01, labelled with gusA{sup +} (Study 1) and celB{sup +} (Study 2) from both eat-sterilizing techniques, reaching values above the minimum of 1x10{sup 8} cells g{sup -1} peat. At high rates

  20. Imaging early demineralization with PS-OCT

    Science.gov (United States)

    Kang, Hobin; Jiao, Jane J.; Lee, Chulsung; Darling, Cynthia L.; Fried, Daniel

    2010-02-01

    New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we attempt to determine the earliest stage at which we can detect significant differences in lesion severity. Automated methods of analysis were used to measure the depth and severity of demineralized bovine enamel produced using a simulated caries model that emulates demineralization in the mouth. Significant differences in the depth and integrated reflectivity from the lesions were detected after only a few hours of demineralization. These results demonstrate that cross polarization OCT is ideally suited for the nondestructive assessment of early demineralization.

  1. Esterilização de soros e vacinas por radiação gama de cobalto Sterilization of sera and vaccines by cobalt gamma radiation

    Directory of Open Access Journals (Sweden)

    Rosalvo Guidolin

    1988-04-01

    Full Text Available Os soros antitetânico, antidiftérico e antibotrópico-crotálico e, ainda, a vacina diftérica-pertussis-tetânica foram submetidos a diferentes intensidades de radiação gama, com os seguintes intuitos: verificação da resistência das atividades específicas destes produtos à ação dos raios gama; avaliação das possibilidades de utilização deste tipo de energia radiante para a esterilização de alguns soros hiperimunes heterólogos e vacinas, mais comumente utilizados em saúde pública. Os resultados obtidos, segundo os parâmetros empregados, mostraram a possibilidade de esterilização sem alterações das atividades específicas, de ordem biológica ou química, dos produtos experimentados.Diphteria, tetanus, anti-snake venom sera and Diphteria-Pertussis-Tetanus vaccine were submited to different intensities of gamma radiation, in order to: verify the resistance of their specific activities to the action of gamma rays; evaluate the possibility of using this type of energy to sterilize some heterogenous hyperimmune sera and vaccines commonly utilized in Public Health. The results, according to the range employed, show the possibility of sterilizing the products tested, without any alteration to specific biological and chemical properties.

  2. Steering the osteoclast through the demineralization-collagenolysis balance

    DEFF Research Database (Denmark)

    Søe, Kent; Merrild, Ditte Marie Horslev; Delaissé, Jean-Marie

    2013-01-01

    are generated when collagen degradation is slower than demineralization, and trenches when collagen degradation is as fast as demineralization. Next we treated the osteoclasts with a low dose of a carbonic anhydrase inhibitor to slightly decrease the rate of demineralization, thereby allowing collagen...

  3. A novel comprehensive approach for human vascular allografts cryopreservation and radiation sterilization for the tissue engineering industry

    Directory of Open Access Journals (Sweden)

    Lauk-Dubitsky S.E.

    2015-12-01

    Full Text Available Aim: to verify new techniques for human cadaveric vascular allografts cryopreservation, thawing and sterilization for the tissue engineering purposes. We use polydimethylsiloxane (PDMS as a well-known, promising coolant. This allowed us to completely omit any cryoprotective or vitrifying solutions. Using of PDMS also makes possible an applying these allografts directly after freezing and decellularization and also it will also provide an opportunity to develop secure protocols of tissue— engineered vascular conduits cryopreservation. Matherial and methods. After mathematical modeling of cooling process and its validation the experiment for sealed (isolated freezing at low temperature conditions of 30 femoral arterial segments has been conducted. The segments were at least 10 cm in length and taken from 15 cadaveric donors in the age of 65-85 years. The freezing process was carried out using the abovementioned coolant— PDMS, and then physico-mechanical properties of these allografts were evaluated with the special Instron machine. According to the results obtained, a modeling of their sterilization conditions was conducted (the grafts were freezed. Results. By physico-mechanical properties validation and restricted histological analysis it was shown that there was an accordance between freezed/thawed allografts properties and native vessels. Conclusion. The abovementioned approach for allografts cryopreservation and thawing was efficient enough for further work in this direction.

  4. Resin diffusion through demineralized dentin matrix

    Directory of Open Access Journals (Sweden)

    CARVALHO Ricardo M.

    1999-01-01

    Full Text Available This paper has focused on the factors that may affect the permeability of adhesive resins into the demineralized dentin matrix during the development of the bonding process. The effects of surface moisture are discussed respectively to the adhesive systems, and the problems related to incomplete hybrid layer formation presented.

  5. Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

    Science.gov (United States)

    Gut, Grzegorz; Marowska, Joanna; Jastrzebska, Anna; Olender, Ewa; Kamiński, Artur

    2016-06-01

    To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not

  6. Female sterilization.

    Science.gov (United States)

    Chapman, Lynne; Magos, Adam

    2008-07-01

    There has been considerable development and implementation of new contraceptive methods over the last 15 years. However, sterilization has remained the most widely used method around the world. Ideally, the procedure should be safe, have a high efficacy, be readily accessible, and be personally and culturally acceptable. The cost for each procedure would be low and the method would be simple, quick, easily learned and be able to be performed in an outpatient setting without general anesthesia. A transuterine method of female sterilization has long been the ideal for the gynecologist. The Essure system fulfils many of the criteria, and is the first one to be approved by the US FDA. However, there is still a need for further research to find a device with the success rate of the Essure but without its irreversibility.

  7. Preparation of denatured protein bone sterilized with gamma radiation; Preparacion de hueso desproteinizado esterilizado con radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Luna Z, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: dlz@nuclear.inin.mx

    2005-07-01

    The bone is one of the tissues more transplanted in the entire world by that the bone necessity for transplant every day becomes bigger. In the Bank of tissues Radio sterilized of the ININ the amnion and the pig skin are routinely processed. The tissue with which will be continued is with bone. Due to that in our country it doesn't have enough bone of human origin for the necessities required in the bone transplant, an option is the bone of bovine. Of this bone one can obtain denatured protein bone, with the same characteristics of the denatured protein human bone, the one which has been proven that it has good acceptance and incorporation in the human body when is transplanted. The method for the obtaining of the denatured protein bone of bovine, with the confirmation of the final product by means of X-ray diffraction is described. The radiosterilization of this bone with gamma rays and the determination of the lead content. (Author)

  8. Study of the effects of {gamma}-radiation followed by chlorination with hypochlorite on coliforms in sterile buffered samples

    Energy Technology Data Exchange (ETDEWEB)

    Tata, A.; Festinesi, A.; Rosa, R.; Adamo, A.; Rossi, G. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione

    1998-04-01

    Radiation and chlorination combined treatment of water samples is investigated in order to evaluate the disinfecting efficacy, observing the growth of reference organisms. [Italiano] Nel presente lavoro sono illustrati i risultati delle analisi condotte su campioni di acqua sottoposti a trattamento combinato con radiazioni e clorazione, al fine di valutare l`efficacia mediante l`osservazione della crescita di organismi di riferimento.

  9. Effects of gamma radiation on development, sterility, fecundity, and sex ratio of Dermanyssus gallinae (DeGeer) (Acari: Dermanyssidae)

    Energy Technology Data Exchange (ETDEWEB)

    Entrekin, D.L.; Oliver, J.H. Jr.; Pound, J.M.

    1987-06-01

    Protonymphal Dermanyssus gallinae were irradiated with 0.50, 0.75, 1.0, 3.0, and 6.0 krad of gamma radiation and subsequently monitored regarding their developmental, feeding, and mating success. Also, sex ratios of adults treated as protonymphs were recorded as were sex ratios of embryos and F1 adults produced by these adults. Doses up to 1.0 krad did not prevent development of treated protonymphs to the adult stage or stop mating. Three krad reduced the number of treated protonymphs attaining adulthood and 6.0-krad treatment prevented all mites from developing to the adult stage. Egg (embryo) production was normal for mites treated with 0.50 krad, but significantly curtailed by doses of 0.75 krad and greater. Radiation doses used in this study did not appear to affect the normal variable sex ratios observed in untreated mites.

  10. Potential of Radiation Sterilization Tempe Pasta as Enteral Nutrition for Patients with Naso Gastric Tube (Ngt) Equipment

    OpenAIRE

    Irawati, Zubaidah

    2013-01-01

    Food irradiation process has a potential to promote of a safe, adequate and nutritious food supply for hospital diets. It has two applications that can contribute to the health and well being of humanity, i.e. the elimination of foodborne pathogens microorganisms, and the preservation of foods by the destruction of pests. Effects of ionizing radiation on tempe pasta selected as samples for patient food intake through Naso Gastric Tube (NGT) has been studied. Tempe pasta was vacuum packed in a...

  11. Comparative study and histomorphometric analysis of bone allografts lyophilized and sterilized by autoclaving, gamma irradiation and ethylene oxide in rats.

    Science.gov (United States)

    Almeida, Otavio Machado de; Jorgetti, Wanda; Oksman, Denis; Jorgetti, Camilo; Rocha, Diógenes Laércio; Gemperli, Rolf

    2013-01-01

    To compare three sterilization methods (autoclave, gamma irradiation and ethylene oxide) over non demineralized lyophilized bone allografts. Bone allografts were implanted on paravertebral muscles of 21 rats. After 30 days animals were sacrificed and grafts underwent comparative analysis regarding histomorphometric and macroscopic parameters. Allografts that underwent the three sterilization methods presents similar weight gain, cortical thickness similar to control group, and less fibrosis than the control group. Grafts that underwent sterilization in autoclave presented less presence of multinucleated giant cells, although not statistically significant. There was also no statistically significant difference regarding mineralization on the three groups. The three sterilization methods cause similar effects on bone allografts regarding macroscopic and histomorphometric parameters.

  12. Bony demineralization following urinary intestinal diversion.

    Science.gov (United States)

    McDougal, W S; Koch, M O; Shands, C; Price, R R

    1988-10-01

    The effect of urinary intestinal diversion on bone mineral metabolism was investigated in 78 rats. The animals were divided into sham-operated controls and diverted animals. The diverted animals were given either no supplement, sodium bicarbonate or ascorbic acid for an eight month period. Dual photon densitometry and bone mineral content were determined. Urinary intestinal diversion resulted in a minimal systemic acidosis and little alteration in baseline renal function but a significant decrease in bone calcium content. Oral bicarbonate and ascorbic acid administration prevented the demineralization.

  13. Plasma Sterilization: New Epoch in Medical Textiles

    Science.gov (United States)

    Senthilkumar, P.; Arun, N.; Vigneswaran, C.

    2015-04-01

    Clothing is perceived to be second skin to the human body since it is in close contact with the human skin most of the times. In hospitals, use of textile materials in different forms and sterilization of these materials is an essential requirement for preventing spread of germs. The need for appropriate disinfection and sterilization techniques is of paramount importance. There has been a continuous demand for novel sterilization techniques appropriate for use on various textile materials as the existing sterilization techniques suffer from various technical and economical drawbacks. Plasma sterilization is the alternative method, which is friendlier and more effective on the wide spectrum of prokaryotic and eukaryotic microorganisms. Basically, the main inactivation factors for cells exposed to plasma are heat, UV radiation and various reactive species. Plasma exposure can kill micro-organisms on a surface in addition to removing adsorbed monolayer of surface contaminants. Advantages of plasma surface treatment are removal of contaminants from the surface, change in the surface energy and sterilization of the surface. Plasma sterilization aims to kill and/or remove all micro-organisms which may cause infection of humans or animals, or which can cause spoilage of foods or other goods. This review paper emphasizes necessity for sterilization, essentials of sterilization, mechanism of plasma sterilization and the parameters influencing it.

  14. The effect of gamma radiation on sterility and mating ability of brown planthopper, Nilaparvata lugens(Stål) in field cage

    Science.gov (United States)

    Limohpasmanee, W.; Kongratarpon, T.; Tannarin, T.

    2017-06-01

    The brown planthopper, Nilaparvata lugens(Stål) is the major rice pest in Thailand. Adults and nymphs suck the sap from the rice plant causing it to wilt and transmitting the grassy stunt and the ragged stunt diseases. The population suppression by the sterile insect technique is overwhelmingly a function of mating between sterile males and wild females. The objectives of these experiments were to determine the suitable dose which induces partially sterile in N. lugens and their effect on wild population in the field cages. One-day-old 4th and 5th instar nymphs and adults were irradiated in a 60Co irradiator at the doses of 30, 60, 90 and 120 Gy. It was found that irradiation at the dose of 90 Gy induced complete sterility in female and 78.47 % sterility in males. The inherited sterility were transferred to their progenies and induced 51.46 and 77.00 % sterility in F-1 males and females. The irradiation as the mention dose did not affect mating ability. The competitiveness index was increased when the ratio of irradiated males per normal male was increased. The releasing irradiated males at 10 fold of normal males in field cages could suppress F-1 population 80.11 % and suppress F-2 population 80.32 % when compare with the control. This technique may be applied to delay and/or reduce seasonal increase of brown planthopper.

  15. Dosimetry requirements derived from the sterilization standards

    DEFF Research Database (Denmark)

    Miller, A.

    1998-01-01

    The main standards for radiation sterilization, ISO 11137 and EN 552, rest the documentation for the properly executed sterilization process on dosimetry. Both standards describe general requirements to the dosimetry system: The dose measurements must be traceable to national standards......, the uncertainty of the dose measurement and the environmental influences must be known. This paper discusses how to obtain and maintain traceability and how to document measurement uncertainty. The implications of these requirements in the process control of radiation sterilization are further discussed. Known...

  16. Sterile dark matter and reionization

    Science.gov (United States)

    Kusenko, Alexander

    2007-11-01

    Sterile neutrinos with masses in the keV range can be the dark matter, and their emission from a supernova can explain the observed velocities of pulsars. The sterile neutrino decays could produce the x-ray radiation in the early universe, which could have an important effect on the formation of the first stars. X-rays could ionize gas and could catalyze the production of molecular hydrogen during the “dark ages”. The increased fraction of molecular hydrogen could facilitate the cooling and collapse of the primordial gas clouds in which the first stars are formed.

  17. Interval Female Sterilization.

    Science.gov (United States)

    Stuart, Gretchen S; Ramesh, Shanthi S

    2018-01-01

    Female sterilization is relied on by nearly one in three women aged 35-44 years in the United States. Sterilization procedures are among the most common procedures that obstetrician-gynecologists perform. The most frequent sterilization procedures include postpartum tubal ligation, laparoscopic tubal disruption or salpingectomy, and hysteroscopic tubal occlusion. The informed consent process for sterilization is crucial and requires shared decision-making between the patient and the health care provider. Counseling should include the specific risks and benefits of the specific surgical approaches. Additionally, women should be counseled on the alternatives to sterilization, including intrauterine contraceptives and subdermal contraceptive implants. Complications, including unplanned pregnancy after successful female sterilization, are rare. The objectives of this Clinical Expert Series are to describe the epidemiology of female sterilization, access to postpartum sterilization, advances in interval sterilization techniques, and clinical considerations in caring for women requesting sterilization.

  18. Transgenic technologies to induce sterility

    Directory of Open Access Journals (Sweden)

    Wimmer Ernst A

    2009-11-01

    Full Text Available Abstract The last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes.

  19. Periodontal instrumentation for the general dental practitioner: Pt. 2. Management maintenance and sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Touyz, L.Z.G. (University of the Witwatersrand, Johannesburg (South Africa). Dept. of Oral Medicine and Periodontology); De Waal, J.

    1983-03-01

    The purpose of this article is to describe the management, maintenance and sterilization of periodontal instrumentation used by the general dental practitioner. The pre-sterilization, decontamination and cleaning, the sharpening of instrumentation and the packaging, identification and grouping for sterilization are discussed. Attention is also given to various techniques of sterilization, including gamma radiation.

  20. Influence of Radiation Sterilization on Properties of Biodegradable Lactide/Glycolide/Trimethylene Carbonate and Lactide/Glycolide/ε-caprolactone Porous Scaffolds with Shape Memory Behavior

    Directory of Open Access Journals (Sweden)

    Piotr Rychter

    2016-01-01

    Full Text Available The aim of the study was the evaluation of gamma irradiation and electron beams for sterilization of porous scaffolds with shape memory behavior obtained from biodegradable terpolymers: poly(l-lactide-co-glycolide-co-trimethylene carbonate and poly(l-lactide-co-glycolide-co-ɛ-caprolactone. The impact of mentioned sterilization techniques on the structure of the scaffolds before and after the sterilization process using irradiation doses ranged from 10 to 25 kGy has been investigated. Treatment of the samples with gamma irradiation at 15 kGy dose resulted in considerable drop in glass transition temperature (Tg and number average molecular weight (Mn. For comparison, after irradiation of the samples using an electron beam with the same dose, no significant changes in structure or properties of examined scaffolds have been noticed. Higher doses of irradiation via electron beam caused essential changes of the scaffolds’ pores resulting in partial melting of their surface. Nevertheless, obtained results have revealed that sterilization with electron beam, when compared to gamma irradiation, is a better method because it does not affect significantly the physicochemical properties of the scaffolds. Both used methods of sterilization did not influence the shape memory behavior of the examined materials.

  1. Sterilization of glycerin.

    Science.gov (United States)

    McCluskey, Susan V

    2008-06-15

    The sterilization of glycerin is described. Glycerin is used in a wide variety of pharmaceutical formulations, including oral, otic, ophthalmic, topical, and parenteral preparations. Of the myriad uses for glycerin, some require a sterile solution. Due to the nature of dry heat sterilization with resulting equipment and validation needs, sterile filtration is the preferred sterilization method for glycerin at the Mayo Clinic Pharmacy Services Production Laboratory in Rochester, Minnesota. A practical procedure was attained with the use of a chemically compatible 0.22-microm capsule filter, peristaltic pump, and sterile tubing. The sterile tubing is attached firmly, with a twisting motion, to the hose barb ends of the filter. The peristaltic pump is set at minimum speed, and a sterile syringe is used to capture the sterile glycerin filtrate. After filtration, filter integrity testing using the bubble point test is performed on the filter used to sterilize the solution. Packaging was then completed by placing glycerin aliquots into unit-of-use sterile syringes, placing a sterile tip cap on each syringe, and labeling the syringe. End testing is needed for preparations, such as sterile glycerin, that are made from nonsterile components, regardless of sterilization technique. This quality-control testing includes but is not limited to visual checks, pH checks, and tests for bacterial endotoxins, particulate matter, and sterility. Beyond-use dating is then assigned based on chemical, physical, microbiological, and packaging considerations. A practical method for sterilization of glycerin by compounding pharmacists is attainable through the use of membrane filtration. Sterility assurance is achieved through appropriate validation, and quality-control checks must be completed before release of the injectable preparation.

  2. Enamel Resistance to Demineralization After Bracket Debonding Using Fluoride Varnish

    OpenAIRE

    Vicente, Ascensión; Ortiz Ruiz, Antonio José; García López, Miriam; Martínez Beneyto, Yolanda; Bravo-González, Luis-Alberto

    2017-01-01

    The aim of this study was to evaluate the elemental content and morphology of enamel subjected to demineralization cycles after bracket debonding, adhesive remnant removal, and application of a fluoride varnish. 125 bovine teeth were divided into five groups (n = 25): 1) Intact enamel; 2) Intact enamel + demineralization cycles (DC); 3) Enamel after adhesive removal; 4)Enamel after adhesive removal + DC; 5) Enamel after adhesive removal + Profluorid + DC. The weight percentages of calcium (Ca...

  3. Cosmology seeking friendship with sterile neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, J.; Hannestad, S. [Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C (Denmark); Raffelt, G.G. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany); Tamborra, I. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany); Dipartimento Interateneo di Fisica ' Michelangelo Merlin' , Via Amendola 173, 70126 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Wong, Y.Y.Y. [Institut fuer Theoretische Teilchenphysik und Kosmologie, RWTH Aachen, 52056 Aachen (Germany)

    2011-08-15

    Precision cosmology and big-bang nucleosynthesis mildly favour extra radiation in the universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We present bounds on the common mass scale ms and effective number Ns of thermally excited sterile neutrino states from the most recent cosmological data. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if ms is in the sub-eV range.

  4. Cosmology seeking friendship with sterile neutrinos

    DEFF Research Database (Denmark)

    Hamann, Jan; Hannestad, Steen; Raffelt, G.G.

    2011-01-01

    Precision cosmology and big-bang nucleosynthesis mildly favour extra radiation in the universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We present bounds on the common mass scale ms and effective number Ns of thermally excited sterile...... neutrino states from the most recent cosmological data. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if ms is in the sub-eV range....

  5. Demineralization around restorations with different restorative materials containing fluoride

    Directory of Open Access Journals (Sweden)

    Seixas Letícia Caliento

    2004-01-01

    Full Text Available The aim of this study was to evaluate in vitro the demineralization on tooth/restoration interface of eight restorative materials after demineralization/remineralization cycling. Eighty class V cavities were prepared with margins at enamel and dentin/cementum, and were restored with Fuji II LC, Fuji IX, Ketac-fil, Ketac Molar, Ariston pHc, Compoglass, Degufill Mineral and Z100. After the restorative procedures, the restorations were submitted to demineralization/ remineralization cycling during 14 days. Specimens were embedded in acrylic resin and submitted to serial sectioning. The sections were examined by optical microscope, and demineralization around restoration was measured on cervical and occlusal margins. The data were analyzed using the ANOVA and Tukey test (p<0.05. Glass ionomer cements showed less demineralization on enamel and dentin/restoration interfaces when compared to the tested composite resins (Z100 and Degufill Mineral. In conclusion, glass ionomer cements suffered less demineralization but did not protect completely the tooth/restoration interface.

  6. Sterilization for Women and Men

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ011 CONTRACEPTION Sterilization for Women and Men • What is sterilization? • How does tubal occlusion work to prevent pregnancy? • How effective is female sterilization? • Does female sterilization ...

  7. The backcross sterility technique

    Science.gov (United States)

    V. C. Mastro; A. Pellegrini-Toole

    1991-01-01

    The sterile insect technique (SIT) and the induced inherited (F1) sterility technique have been investigated for a number of lepidopterous pests, including the gypsy moths. Another technique, backcross sterility, which could potentially prove as or more useful for control of pest species has been developed for the control of only one lepidopteran...

  8. Thermalisation of light sterile neutrinos in the early universe

    DEFF Research Database (Denmark)

    Hannestad, Steen; Tamborra, Irene; Tram, Thomas

    2012-01-01

    Recent cosmological data favour additional relativistic degrees of freedom beyond the three active neutrinos and photons, often referred to as 'dark' radiation. Light sterile neutrinos is one of the prime candidates for such additional radiation. However, constraints on sterile neutrinos based...... on the current cosmological data have been derived using simplified assumptions about thermalisation of the sterile neutrino at the Big Bang Nucleosynthesis (BBN) epoch. These assumptions are not necessarily justified and here we solve the full quantum kinetic equations in the (1 active + 1 sterile) scenario...

  9. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  10. Radiation biology of mosquitoes

    OpenAIRE

    Knols Bart GJ; Parker Andrew G; Helinski Michelle EH

    2009-01-01

    Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage....

  11. Characteristics of Surface Sterilization using ECR Plasma

    Science.gov (United States)

    Yonesu, Akira; Hara, Kazufumi; Nishikawa, Tatsuya; Hayashi, Nobuya

    2015-09-01

    Plasma sterilization techniques have superior characteristics such as a short treatment times, non-toxicity and low thermal damages on the sterilized materials. In plasma sterilization, microorganisms can be sterilized by active radicals, energetic charged particles, and vacuum UV radiation. The influence of each factor depends on the plasma operating parameters. Microwave discharges under the electron cyclotron resonance (ECR) condition produce higher electron temperature and density plasma as compared with other plasma generation techniques. In the present study, characteristics of surface sterilization using ECR plasma have been investigated.The experiment was performed in the vacuum chamber which contains a magnet holder. A pair of rectangular Sm-Co permanent magnets is aligned parallel to each other within the magnet holder. The region of the magnetic field for ECR exists near the magnet holder surface. When the microwave is introduced into the vacuum chamber, a ECR plasma is produced around surface of the magnet holder. High energy electrons and oxygen radicals were observed at ECR zone by electric probe method and optical spectroscopic method. Biological indicators (B.I.) having spore of 106 was sterilized in 2min for oxygen discharge. The temperature of the B.I. installation position was about 55°. The sterilization was achieved by the effect of oxygen radicals and high energy electrons.

  12. Effect of fluoride toothpastes on enamel demineralization

    Directory of Open Access Journals (Sweden)

    Gintner Zeno

    2006-06-01

    Full Text Available Abstract Background It was the aim of this study to investigate the effect of four different toothpastes with differing fluoride compounds on enamel remineralization. Methods A 3 × 3 mm window on the enamel surface of 90 human premolars was demineralized in a hydroxyethylcellulose solution at pH 4.8. The teeth were divided into 6 groups and the lower half of the window was covered with varnish serving as control. The teeth were immersed in a toothpaste slurry containing: placebo tooth paste (group 1; remineralization solution (group 2; Elmex Anticaries (group 3; Elmex Sensitive (group 4; Blend-a-med Complete (group 5 and Colgate GRF (group 6. Ten teeth of each group were used for the determination of the F- content in the superficial enamel layer and acid solubility of enamel expressed in soluble phosphorus. Of 6 teeth of each group serial sections were cut and investigated with polarization light microscopy (PLM and quantitative energy dispersive X-ray analysis (EDX. Results The PLM results showed an increased remineralization of the lesion body in the Elmex Anticaries, Elmex Sensitive and Colgate GRF group but not in the Blend-a-med group. A statistically significant higher Ca content was found in the Elmex Anticaries group. The fluoride content in the superficial enamel layer was significantly increased in both Elmex groups and the Blend-a-med group. Phosphorus solubility was significantly decreased in both Elmex groups and the Blend-a-med group. Conclusion It can be concluded that amine fluoride compounds in toothpastes result in a clearly marked remineralization of caries like enamel lesions followed by sodium fluoride and sodium monofluorophosphate formulations.

  13. ROC analysis of acid demineralized artificial caries

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Cheol [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chonnam National University, Kwangju (Korea, Republic of)

    1997-08-15

    This study is designed to determine the artificial incipient proximal caries lesion detectability by dentists on Ektaspeed Plus film using ROC analysis. Sixteen premolars and 30 molars, which have 52 proximal caries-like demineralized lesions using acid-gel technique were added to 20 sound premolars and 30 sound molars to make 24 plaster blocks. Each block with 4 teeth and 6 contacting proximal surfaces was placed in an optical bench to take 12 bitewing radiographs with Ektaspeed Plus film. Thirty-six dentists acted as observers to evaluated the proximal lesions using five rating scales for ROC analysis. They were also asked to determine the presence or absence of the proximal caries. The true status of the proximal caries was established by the consensus of three oral and maxillofacila radiologists. For evaluation of intra-observer agreement, 9 dentist reread the radiographs at an interval of 1 month. The Pearson correlation coefficient for the intra-observer agreement was 0.746 (good agreement). Ten observer's data set were degenerated. The mean area under ROC curve from 26 observers was 0.806 and standard deviation was 0.061. The sensitivity and the specificity of the binary response were 0.17 (SD=0.11) and 0.78 (SD=0.17) respectively. The binary response only reveal a single values of sensitivity and the specificity. The ROC analysis to assess the diagnostic accuracy in caries detection, which producing estimates of sensitivities for all specifities, yield more comprehensive measures of diagnostic performance than single values for sensitivity and specificity.

  14. Sterilization of endoscopic instruments.

    Science.gov (United States)

    Sabnis, Ravindra B; Bhattu, Amit; Vijaykumar, Mohankumar

    2014-03-01

    Sterilization of endoscopic instruments is an important but often ignored topic. The purpose of this article is to review the current literature on the sterilization of endoscopic instruments and elaborate on the appropriate sterilization practices. Autoclaving is an economic and excellent method of sterilizing the instruments that are not heat sensitive. Heat sensitive instruments may get damaged with hot sterilization methods. Several new endoscopic instruments such as flexible ureteroscopes, chip on tip endoscopes, are added in urologists armamentarium. Many of these instruments are heat sensitive and hence alternative efficacious methods of sterilization are necessary. Although ethylene oxide and hydrogen peroxide are excellent methods of sterilization, they have some drawbacks. Gamma irradiation is mainly for disposable items. Various chemical agents are widely used even though they achieve high-level disinfection rather than sterilization. This article reviews various methods of endoscopic instrument sterilization with their advantages and drawbacks. If appropriate sterilization methods are adopted, then it not only will protect patients from procedure-related infections but prevent hypersensitive allergic reactions. It will also protect instruments from damage and increase its longevity.

  15. Clinical assessment of demineralization and remineralization surrounding orthodontic brackets with FluoreCam

    Directory of Open Access Journals (Sweden)

    Bora Korkut

    2017-04-01

    Conclusions: This study demonstrated that demineralization is measurable around orthodontic brackets and the demineralization can be completely inhibited and/or reversed by the use of commercially available remineralization products.

  16. [Regret of female sterilization].

    Science.gov (United States)

    Öhman, Malin Charlotta; Andersen, Lars Franch

    2015-11-16

    Regret of sterilization is inversely correlated to age at the time of sterilization. The minimum age for legal sterilization in Denmark has recently been lowered to 18 years. In Denmark surgical refertilization has almost completely been replaced by in vitro fertilization (IVF). In recent literature pregnancy results after surgical refertilization are easily comparable to IVF. Refertilization may in some cases be advantageous to IVF treatment. Women requesting reversal of sterilization should be offered individualized evaluation and differentiated treatment. It is recommended that surgical refertilization is performed at very few centres.

  17. Determination of bone demineralization in cats after experimental thyrotoxicosis

    Directory of Open Access Journals (Sweden)

    Fabiano Séllos Costa

    2006-10-01

    Full Text Available Hyperthyroidism can result in serious effects on the bone metabolism in humans as well as animals. For a better characterization of thyrotoxicosis effects, 16 cats were induced into thyrotoxicosis by intaking a dose of 150 µg/kg of sodium L-thyroxine every 24 hours during 42 days. The hormonal levels were evaluated by radioimmunoassay technique and the bone mineral density of the right distal radius extremity was measured through the radiographic optical densitometry. Was verified significant bone demineralization seven days of hormonal intake as weel as radius demineralization.

  18. IAEA/FAO interregional training course on use of radiation in insect control and entomology with special emphasis on the sterile insect technique. Final report, May 4--June 15, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The principal focus of the course was the application of Radiation in Entomology to achieve Area Wide Pest Suppression or Eradication. To achieve this objective formal lectures, discussion groups, laboratory exercises and field trips were held covering the details of: (1) principles, programs and research of all aspects of the Sterile Insect Technique; (2) insect biology and control; (3) integrated pest management; (4) population dynamics and models related to the development of SIT and insect population suppression; (5) fundamentals of computers for helping in development of SIT; (6) the importance of economic considerations in formulating area wide pest management programs. The course included tours of local laboratories of the University, USDA, and the State Division of Plant Industry (DPI), and a site visit to a citrus production area in which the pest-free zone concept of pest management for fruit export is utilized.

  19. Determination of the dose of gamma radiation sterilization for assessment of biological parameters of male Ceratitis capitada (Diptera: Tephritidae), tsl - Vienna 8 strain; Determinacao da dose de radiacao gama esterilizante pela avaliacao dos parametros biologicos de machos de Ceratitis capitata (Diptera: Tephritidae), linhagem tsl - Vienna 8

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Aline Cristina Pereira da

    2011-07-01

    The Vienna-8, tsl (temperature sensitive lethal) strain of Ceratitis capitata, by presenting mutations that facilitate the mass rearing and release only of sterile males in the field, has been used in (Sterile Insect Technique) programmes. The objective of this study was to determine the radiation dose that provides the highest level of sterility for Vienna-8, tsl males assessing their biological parameters that indicate the quality of sterile males to be released. Brown pupae (males) of the tsl strain were obtained from the mass rearing of the Food Irradiation and Radio entomology laboratory of CENA/USP, and they were irradiated (with gamma radiation - {sup 60}Co) 24 hours before the emergence at rates of 0, 30, 60, 90 and 120 Gy. The determination of the sterilizing dose was based on fertility of sexually mature females of the bisexual strain and not irradiated, mated with males of different treatments. Eggs were collected daily during 6 days, were counted and it was possible to estimate fecundity, and assess the hatching rate. The emergence and flight ability were determined by following the protocol of quality control manual for FAO/IAEA/USDA (2003). To assess the longevity under nutritional stress, the insects were kept a period of 48 h after emergence in the absence of water and food, and after this period, mortality was recorded. The size of the testes (left and right) was obtained by dissecting irradiated and non-irradiated males at the eighth day of life, and measure the testes in an ocular micrometer, considering the maximum length and width of each sample. To determine the sperm number was necessary to dissect the males and break their testicles. No difference was observed in emergence rate, flight ability and longevity of irradiated and non-irradiated males, nor in the fecundity of females mated with males of different treatments. The sterilizing dose that resulted in lower fertility of females was 120 Gy, with 1.5% hatching. Considering the parameters

  20. Supercritical carbon dioxide-based sterilization of decellularized heart valves.

    Science.gov (United States)

    Hennessy, Ryan S; Jana, Soumen; Tefft, Brandon J; Helder, Meghana R; Young, Melissa D; Hennessy, Rebecca R; Stoyles, Nicholas J; Lerman, Amir

    2017-02-01

    The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe

  1. A dual energy micro-CT methodology for visualization and quantification of biofilm formation and dentin demineralization.

    Science.gov (United States)

    Pires, Paula Maciel; Santos, Thais Pires Dos; Fonseca-Gonçalves, Andrea; Pithon, Matheus Melo; Lopes, Ricardo Tadeu; Neves, Aline de Almeida

    2018-01-01

    The aim of this study was to induce artificial caries in human sound dentin by means of a microcosm model using human saliva as source of bacteria and to apply a novel dual-energy micro-CT technique to quantify biofilm formation and evaluate its demineralization potential. Eight sound third molars had the occlusal enamel removed by cutting with a diamond disk and five cylindrical cavities (±2mm diameter; ±1.5mm depth) were prepared over the dentin surface in each specimen (n=40 cavities). After sterilization, each specimen received the bacterial salivary inoculum obtained from individuals without any systemic diseases presenting dentin caries lesions and were incubated in BHI added of with 5% sucrose for 96h to allow biofilm formation. After that, two consecutive micro-CT scans were acquired from each specimen (40kv and 70kv). Reconstruction of the images was performed using standardized parameters. After alignment, registration, filtering and image calculations, a final stack of images containing the biofilm volume was obtained from each prepared cavity. Dentin demineralization degree was quantified by comparison with sound dentin areas. All data were analyzed using Shapiro-Wilk test and Spearman correlation using α=5%. Dual-energy micro-CT technique disclosed biofilm formation in all cavities. Biofilm volume inside each cavity varied from 0.30 to 1.57mm3. A positive correlation between cavity volume and volume of formed biofilm was obtained (0.77, penergy micro-CT technique was successful in the quantification of a microcosm human bacterial biofilm formation and to quantify its demineralization potential in vitro. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Anisotropy in Bone Demineralization Revealed by Polarized Far-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Roman Schuetz

    2015-04-01

    Full Text Available Bone material is composed of an organic matrix of collagen fibers and apatite nanoparticles. Previously, vibrational spectroscopy techniques such as infrared (IR and Raman spectroscopy have proved to be particularly useful for characterizing the two constituent organic and inorganic phases of bone. In this work, we tested the potential use of high intensity synchrotron-based far-IR radiation (50–500 cm−1 to gain new insights into structure and chemical composition of bovine fibrolamellar bone. The results from our study can be summarized in the following four points: (I compared to far-IR spectra obtained from synthetic hydroxyapatite powder, those from fibrolamellar bone showed similar peak positions, but very different peak widths; (II during stepwise demineralization of the bone samples, there was no significant change neither to far-IR peak width nor position, demonstrating that mineral dissolution occurred in a uniform manner; (III application of external loading on fully demineralized bone had no significant effect on the obtained spectra, while dehydration of samples resulted in clear differences. (IV using linear dichroism, we showed that the anisotropic structure of fibrolamellar bone is also reflected in anisotropic far-IR absorbance properties of both the organic and inorganic phases. Far-IR spectroscopy thus provides a novel way to functionally characterize bone structure and chemistry, and with further technological improvements, has the potential to become a useful clinical diagnostic tool to better assess quality of collagen-based tissues.

  3. Induction of osteogenesis by demineralized homologous and xenograft bone matrix

    Directory of Open Access Journals (Sweden)

    Dall'Agnol Rosiris

    2003-01-01

    Full Text Available The osteogenesis induction by demineralized bone matrix grafts remains as a challenge in the reconstructions of the mandible through homologous and xenografts or in implants in abdominal muscle. PURPOSE: Observed the behaviour of implants of demineralized bone matrix at the mandible (right side with homologous graft and left side with xenograft of pig. METHODS: Experimental study with homologous and heterologous implants of demineralized bone matrix at the mandible and in ectopic muscle at the Center of Experimental Surgery of Heliopolis Hospital, Hosphel, São Paulo, Brazil. In 6 white New Zeland rabbits, 46 grafts were performed being 23 with homologous (rabbit and 23 with xenograft (pig. 12 homologous implants (6 at the right side of the mandible and 6 at abdominal muscle of the rabbit and 12 heterologous implants of pigs (6 at the left side of the mandible and 6 at abdominal muscle rabbit were performed with demineralized bone matrix. RESULTS: Osteogenesis was assessed through histologic features after 30 and 60 days. After 1 rabbit dead, osteogenesis (mandible were detected in 9 of 11 (82% rabbits that received homologous matrix, in spite of heterologous implants showed osteogenesis in 6 out of 11 (54% (p=0,18. The abdominal muscle showed induced osteogenesis in 3 out of 11(27% animals with homologous and 0% with heterologous implants (p=0,10. CONCLUSIONS: Osteogenesis induction through homologous grafts in rabbit mandible and abdominal muscle were more effective than xenografts.

  4. Penetration of varnishes into demineralized root dentine in vitro

    NARCIS (Netherlands)

    Arends, J; Duschner, H; Ruben, JL

    1997-01-01

    In this paper the penetration of three different varnishes employed in caries prevention (Duraphat(R), Fluor Protector(R) and Cervitec(R)) into demineralized dentine is quantified using confocal laser scanning microscopy. The results show that the varnish penetration into lesions about 85 mu m in

  5. APF and dentifrice effect on root dentin demineralization and biofilm

    NARCIS (Netherlands)

    Vale, G.C.; Tabchoury, C.P.M.; Del Bel Cury, A.A.; Tenuta, L.M.A.; ten Cate, J.M.; Cury, J.A.

    2011-01-01

    Because dentin is more caries-susceptible than enamel, its demineralization may be more influenced by additional fluoride (F). We hypothesized that a combination of professional F, applied as acidulated phosphate F (APF), and use of 1100-ppm-F dentifrice would provide additional protection for

  6. Staining of dentin from amalgam corrosion is induced by demineralization

    NARCIS (Netherlands)

    Scholtanus, J.D.; van der Hoorn, W.; Özcan, M.; Huysmans, M.C.D.N.J.M.; Roeters, J.F.M.; Kleverlaan, C.J.; Feilzer, A.J.

    2013-01-01

    PURPOSE: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. METHODS: Sound human molars (n = 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n

  7. Staining of dentin from amalgam corrosion is induced by demineralization

    NARCIS (Netherlands)

    Scholtanus, Johannes D.; van der Hoorn, Wietske; Huysmans, Marie-Charlotte D. N. J. M.; Roeters, Joost F. M.; Kleverlaan, Cornelis J.; Feilzer, Albert J.; Ozcan, Mutlu

    Purpose: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. Methods: Sound human molars (n= 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n=

  8. Infiltration of demineralized dentin with silica and hydroxyapatite nanoparticles.

    Science.gov (United States)

    Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

    2012-09-01

    The management of demineralized dentin resulting from dental caries or acid erosion remains an oral healthcare clinical challenge. This paper investigates, through a range of studies, the ability of colloidal silica and hydroxyapatite (HA) nanoparticles to infiltrate the collagen structure of demineralized dentin. Dentin samples were completely demineralized in 4 N formic acid. The remaining collagen matrix of the dentin samples was subsequently infiltrated with a range of nano-particulate colloidal silica and HA solutions. The effectiveness and extent of the infiltration was evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Silica nanoparticles have the ability to penetrate dentin and remain embedded within the collagen matrix. It is suggested that particle size plays a major role in the degree of dentin infiltration, with smaller diameter particles demonstrating a greater infiltrative capacity. The infiltration of demineralized dentin with sol-gel HA nanoparticles was limited but was significantly increased when combined with the deflocculating agent sodium hexametaphosphate. The use of acetone as a transport vehicle is reported to enhance the infiltration capacity of sol-gel HA nanoparticles. Collagen infiltrated with HA and silica nanoparticles may provide a suitable scaffold for the remineralization of dentin, whereby the infiltrated particles act as seeds within the collage matrix and given the appropriate remineralizing environment, mineral growth may occur. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. Avaliação da eficiência da radiação ultravioleta na esterilização de embalagens plásticas Evaluation of ultraviolet radiation in the sterilization of plastic packaging

    Directory of Open Access Journals (Sweden)

    Fernanda Antunes Alexandre

    2008-10-01

    Full Text Available O uso da radiação ultravioleta é um dos vários processos físicos que podem ser utilizados para a esterilização ou na higienização de superfícies que irão entrar em contato com alimentos. Objetivou-se, nesta pesquisa a avaliação da eficiência da radiação ultravioleta (UV na esterilização de superfícies de embalagens para alimentos visando a redução da contaminação microbiológica. Tampas e filmes plásticos foram irradiados em uma fonte de ultravioleta emitindo comprimentos de ondas a 254 nm, no interior de uma câmara especialmente projetada para este estudo, através de um delineamento fatorial para testar as variáveis: tempo de exposição e intensidade de irradiação (distância da fonte. Avaliou-se o número de reduções decimais de esporos de Bacillus subtilis inoculados na superfície das embalagens. As reduções decimais obtidas não foram altas, variaram de 0,21 a 2,47, mas o uso da lâmpada UV foi altamente eficiente para tempo de exposição superior a 30 s e distância mínima de 20 cm da fonte, causando a redução total da carga microbiana inoculada.Ultraviolet radiation is one of the major physical processes used to sterilize or to clean surfaces that will be in contact of foods. This research evaluated the efficiency of ultraviolet (UV radiation to sterilize surfaces of plastic packaging materials based on the reduction of microbial counts. Plastic closures and films were irradiated by exposing them to lamps emitting UV radiation at 254 nm in an apparatus specially constructed for this study. Using an experimental design in order to investigate the effect of exposure time and distance from the source, the reduction number of Bacillus subtilis spores inoculated to the package surfaces were evaluated. The UV radiation efficiency was not high for short exposition time, presenting reduction number ranged from 0.21 to 2.47, but it was very efficient when exposed to more than 30 s at a distance of 20 cm.

  10. Dosimetry intercomparisons in European medical device sterilization plants

    DEFF Research Database (Denmark)

    Miller, A.; Sharpe, P.H.G.

    2000-01-01

    Dosimetry intercomparisons have been carried out involving two-thirds of all European radiation sterilization facilities. Dosimeters for the intercomparisons were supplied by two accredited calibration laboratories. The results show good agreement, and indicate overall dosimetry accuracy of the o......Dosimetry intercomparisons have been carried out involving two-thirds of all European radiation sterilization facilities. Dosimeters for the intercomparisons were supplied by two accredited calibration laboratories. The results show good agreement, and indicate overall dosimetry accuracy...

  11. Biological Sterilization of Returned Mars Samples

    Science.gov (United States)

    Allen, C. C.; Albert, F. G.; Combie, J.; Bodnar, R. J.; Hamilton, V. E.; Jolliff, B. L.; Kuebler, K.; Wang, A.; Lindstrom, D. J.; Morris, P. A.

    1999-01-01

    Martian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.

  12. Sterilization of space hardware.

    Science.gov (United States)

    Pflug, I. J.

    1971-01-01

    Discussion of various techniques of sterilization of space flight hardware using either destructive heating or the action of chemicals. Factors considered in the dry-heat destruction of microorganisms include the effects of microbial water content, temperature, the physicochemical properties of the microorganism and adjacent support, and nature of the surrounding gas atmosphere. Dry-heat destruction rates of microorganisms on the surface, between mated surface areas, or buried in the solid material of space vehicle hardware are reviewed, along with alternative dry-heat sterilization cycles, thermodynamic considerations, and considerations of final sterilization-process design. Discussed sterilization chemicals include ethylene oxide, formaldehyde, methyl bromide, dimethyl sulfoxide, peracetic acid, and beta-propiolactone.

  13. Contraception Update: Sterilization.

    Science.gov (United States)

    Antell, Karen; Deshmukh, Prium; Brown, Elizabeth J

    2017-11-01

    Female sterilization procedures include postpartum partial salpingectomy via cesarean or minilaparotomy incision, interval laparoscopic procedures, or hysteroscopic placement of microinserts. Rates of failure and serious complications are low and comparable among the various methods. A hysteroscopic procedure requires a 3-month confirmatory hysterosalpingogram before it is considered effective for contraception. Hysteroscopic sterilization has been shown to be associated with a higher reoperation rate than laparoscopic procedures. For male sterilization, vasectomy is a noninvasive and highly effective method. Vasectomy is an outpatient procedure performed under local anesthesia. The procedure requires confirmation of azoospermia with a semen analysis 8 to 16 weeks after the procedure. Patients who are considering sterilization should be counseled about all the available options and the permanent nature of such procedures. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

  14. Female Sterilization: Comparative Study of Hysteroscopic versus Laparoscopic Sterilization

    OpenAIRE

    Correia, L; Queirós, A; Machado, AI; Delgado, E.; Farelo, A

    2011-01-01

    Overview and Aims: Female sterilization is increasingly requested as a contraceptive method. Hysteroscopic sterilization by transcervical placing of Essure® micro-inserts in the initial portion of the tubes is a recent alternative to laparoscopic sterilization. The objective of this study is to evaluate the safety and effectiveness of hysteroscopic versus laparoscopic sterilization. Study Design: Retrospective cohort study. Population: A total of 98 women undergoing sterilization in an ...

  15. Hybrid Sterility, Mouse

    OpenAIRE

    Forejt, J

    2013-01-01

    The review summarizes hybrid sterility as the best studied example of reproductive isolation between closely related species. On the model of infertile hybrids of two domestic mouse subspecies, Mus musculus musculus and Mus musculus domesticus, we have demonstrated interaction of hybrid sterility genes with epigenetic control of transcriptional inactivation of the X and Y sex chromosomes. This leads to the activation of pachytene checkpoint and finally results in the arrest of spermatogenesis.

  16. Mechanisms of male sterility in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Yasuo (Tsukuba Univ., Sakura, Ibaraki (Japan))

    1982-03-01

    The mechanisms causing male sterility in higher plants were classified into two major categories: genetic and non-genetic. The former was further divided into six classes: 1) Anomality in spindle mechanism during meiosis, 2) chromosomal anomality such as haploidy, polyploidy, aneuploidy, chromosome some deficiency, inversion and reciprocal translocation, 3) presence of male sterile genes, 4) cytoplasmic abnormality, 5) the combination of some specific cytoplasm with particular genes, and 6) infections of microorganisms or viruses. Each mechanism was briefly explained, and the methods for the maintenance of parent lines for heterosis breeding and hybrid seed production were described. The non-genetic male sterility was classified into four types, which are caused by 1) low or high temperature, 2) water deficiency, 3) application of chemicals, and 4) radiation, with a brief explanation given for each of them.

  17. Sterilization: A Review and Update.

    Science.gov (United States)

    Moss, Chailee; Isley, Michelle M

    2015-12-01

    Sterilization is a frequently used method of contraception. Female sterilization is performed 3 times more frequently than male sterilization, and it can be performed immediately postpartum or as an interval procedure. Methods include mechanical occlusion, coagulation, or tubal excision. Female sterilization can be performed using an abdominal approach, or via laparoscopy or hysteroscopy. When an abdominal approach or laparoscopy is used, sterilization occurs immediately. When hysteroscopy is used, tubal occlusion occurs over time, and additional testing is needed to confirm tubal occlusion. Comprehensive counseling about sterilization should include discussion about male sterilization (vasectomy) and long-acting reversible contraceptive methods. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Remineralizing effect of cold plasma and/or bioglass on demineralized enamel.

    Science.gov (United States)

    El-Wassefy, Noha A

    2017-03-31

    This study investigated the combining effect of cold plasma and bioglass-phosphoric acid paste on demineralized enamel. Fifty bovine incisors' enamel specimens were challenged by a demineralization solution of pH 4.47 for 72 h. Specimens were divided into five groups: (I) Control, demineralized enamel (C); (II) Demineralized enamel treated with fluoride varnish (F); (III) Cold plasma application to demineralized enamel (P); (IV) Demineralized enamel treated with bioglass paste (B); (V) Application of bioglass paste to cold plasma-treated demineralized enamel (PB). Specimens were then immersed in remineralizing solution for 24 h, before being examined with micro-computed tomography (micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and cross-sectional micro-hardness measurement. The results showed that; treating demineralized enamel with cold plasmas before bioglass application ensued a significant high mineral volume recovery and micro-hardness of demineralized region. It can be concluded that cold plasmas may improve the remineralization of bioglass on demineralized enamel.

  19. Hysteroscopic Tubal Sterilization

    Science.gov (United States)

    McMartin, K

    2013-01-01

    Background Hysteroscopic tubal sterilization is a minimally invasive alternative to laparoscopic tubal ligation for women who want permanent contraception. The procedures involves non-surgical placement of permanent microinserts into both fallopian tubes. Patients must use alternative contraception for at least 3 months postprocedure until tubal occlusion is confirmed. Compared to tubal ligation, potential advantages of the hysteroscopic procedure are that it can be performed in 10 minutes in an office setting without the use of general or even local anesthesia. Objective The objective of this analysis was to determine the effectiveness and safety of hysteroscopic tubal sterilization compared with tubal ligation for permanent female sterilization. Data Sources A standard systematic literature search was conducted for studies published from January 1, 2008, until December 11, 2012. Review Methods Observational studies, randomized controlled trials (RCTs), systematic reviews and meta-analyses with 1 month or more of follow-up were examined. Outcomes included failure/pregnancy rates, adverse events, and patient satisfaction. Results No RCTs were identified. Two systematic reviews covered 22 observational studies of hysteroscopic sterilization. Only 1 (N = 93) of these 22 studies compared hysteroscopic sterilization to laparoscopic tubal ligation. Two other noncomparative case series not included in the systematic reviews were also identified. In the absence of comparative studies, data on tubal ligation were derived for this analysis from the CREST study, a large, multicentre, prospective, noncomparative observational study in the United States (GRADE low). Overall, hysteroscopic sterilization is associated with lower pregnancy rates and lower complication rates compared to tubal ligation. No deaths have been reported for hysteroscopic sterilization. Limitations A lack of long-term follow-up for hysteroscopic sterilization and a paucity of studies that directly

  20. Comparative study and histomorphometric analysis of bone allografts lyophilized and sterilized by autoclaving, gamma irradiation and ethylene oxide in rats

    Directory of Open Access Journals (Sweden)

    Otavio Machado de Almeida

    2013-01-01

    Full Text Available PURPOSE: To compare three sterilization methods (autoclave, gamma irradiation and ethylene oxide over non demineralized lyophilized bone allografts. METHODS: Bone allografts were implanted on paravertebral muscles of 21 rats. After 30 days animals were sacrificed and grafts underwent comparative analysis regarding histomorphometric and macroscopic parameters. RESULTS: Allografts that underwent the three sterilization methods presents similar weight gain, cortical thickness similar to control group, and less fibrosis than the control group. Grafts that underwent sterilization in autoclave presented less presence of multinucleated giant cells, although not statistically significant. There was also no statistically significant difference regarding mineralization on the three groups. CONCLUSION: The three sterilization methods cause similar effects on bone allografts regarding macroscopic and histomorphometric parameters.

  1. The effects of microabrasion on demineralization inhibition of enamel surfaces.

    Science.gov (United States)

    Segura, A; Donly, K J; Wefel, J S

    1997-07-01

    Microabraded enamel acquires a highly polished surface of mineralized tissue. The purpose of this study was to determine if microabraded enamel surfaces are more resistant to demineralization. Twenty extracted permanent incisors were used in the experiment. Four treatment modalities were investigated: (1) microabrasion in conjunction with a topical fluoride treatment, (2) topical fluoride treatment, (3) microabrasion, and (4) no treatment. All surfaces, following their respective treatment regimen, were stored in artificial saliva for 2 months and then exposed to an artificial caries system for 5 days. Teeth treated with microabrasion followed by a 4-minute application of 1% neutral topical sodium fluoride exhibited significantly less enamel demineralization when subjected to an artificial caries challenge than did teeth that underwent microabrasion alone, topical fluoride treatment alone, or no treatment at all.

  2. Physicomechanical properties of the extracellular matrix of a demineralized bone

    Science.gov (United States)

    Kirilova, I. A.; Sharkeev, Yu. P.; Nikolaev, S. V.; Podorozhnaya, V. T.; Uvarkin, P. V.; Ratushnyak, A. S.; Chebodaeva, V. V.

    2016-08-01

    The article describes the results of a study of physicomechanical properties of a demineralized bone matrix of human cancellous and compact bones. A demineralized cancellous bone was shown to have the best characteristics of a porous system for colonization of matrices by cells. The ultimate stress and elasticity modulus of samples of demineralized femoral heads isolated in primary hip replacement was demonstrated to vary in wide ranges. The elasticity modulus ranged from 50 to 250 MPa, and the tensile strength varied from 1.1 to 5.5 MPa. Microhardness measurements by the recovered indentation method were not possible because of the viscoelastic properties of a bone material. To study the piezoelectric properties of samples, a measuring system was developed that comprised a measuring chamber with contact electrodes, a system for controlled sample loading, an amplifier-converter unit, and signal recording and processing software. The measurement results were used to determine the dependence of the signal amplitude on the dynamic deformation characteristics. The findings are discussed in terms of the relationship between the mechanical and electrical properties and the structure of the organic bone component.

  3. Forensic DNA typing from teeth using demineralized root tips.

    Science.gov (United States)

    Corrêa, Heitor Simões Dutra; Pedro, Fabio Luis Miranda; Volpato, Luiz Evaristo Ricci; Pereira, Thiago Machado; Siebert Filho, Gilberto; Borges, Álvaro Henrique

    2017-11-01

    Teeth are widely used samples in forensic human genetic identification due to their persistence and practical sampling and processing. Their processing, however, has changed very little in the last 20 years, usually including powdering or pulverization of the tooth. The objective of this study was to present demineralized root tips as DNA sources while, at the same time, not involving powdering the samples or expensive equipment for teeth processing. One to five teeth from each of 20 unidentified human bodies recovered from midwest Brazil were analyzed. Whole teeth were demineralized in EDTA solution with daily solution change. After a maximum of approximately seven days, the final millimeters of the root tip was excised. This portion of the sample was used for DNA extraction through a conventional organic protocol. DNA quantification and STR amplification were performed using commercial kits followed by capillary electrophoresis on 3130 or 3500 genetic analyzers. For 60% of the unidentified bodies (12 of 20), a full genetic profile was obtained from the extraction of the first root tip. By the end of the analyses, full genetic profiles were obtained for 85% of the individuals studied, of which 80% were positively identified. This alternative low-tech approach for postmortem teeth processing is capable of extracting DNA in sufficient quantity and quality for forensic casework, showing that root tips are viable nuclear DNA sources even after demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Demineralization of Enamel in Primary Second Molars Related to Properties of the Enamel

    Directory of Open Access Journals (Sweden)

    N. Sabel

    2012-01-01

    Full Text Available Enamel structure is of importance in demineralization. Differences in porosity in enamel effect the rate of demineralization, seen between permanent and deciduous teeth. Individual differences have been shown in the mean mineral concentration values in enamel, the role of this in demineralization is not thoroughly investigated. The aim of this study was to study variations of depths of artificial lesions of demineralization and to analyze the depth in relation to variations in the chemical and mineral composition of the enamel. A demineralized lesion was created in second primary molars from 18 individuals. Depths of lesions were then related to individual chemical content of the enamel. Enamel responded to demineralization with different lesion depths and this was correlated to the chemical composition. The carbon content in sound enamel was shown to be higher where lesions developed deeper. The lesion was deeper when the degree of porosity of the enamel was higher.

  5. Removal of different fractions of NOM foulants during demineralized water backwashing

    KAUST Repository

    Li, Sheng

    2012-09-01

    The effectiveness of demineralized water backwashing on fouling by different fractions of NOM was investigated in this study. Two types of natural surface water (Schie canal and Biesbosch reservoir) were tested to confirm the improvement of demineralized water backwashing on fouling control, and LC-OCD analysis was conducted on Schie canal water to find out which fraction of NOM was removed with those backwashes. Results derived from natural waters showed that demineralized water backwashing substantially improved UF fouling control. LC-OCD analyses showed both UF permeate and demineralized water backwashes were effective on removing part of biopolymers, but demineralized water is also effective for humic substances and a limited amount of low molecular weight substances. However, based on the LC-OCD results, even demineralized water backwashing is not effective to remove all humic substances and biopolymers rejected on the UF membranes. © 2012 Elsevier B.V. All rights reserved.

  6. Enamel demineralization after different methods of interproximal polishing.

    Science.gov (United States)

    Hellak, Andreas F; Riepe, Esther M; Seubert, Andreas; Korbmacher-Steiner, Heike M

    2015-11-01

    The aim of this in vitro study was to investigate the demineralization rate in human enamel after interproximal polishing (IPP) and to detect possible correlations with the IPP method used, with special emphasis on the surface characteristics of the enamel being treated. This in vitro study tested five IPP systems (Profin Directional System®, Intensiv ProxoStrip®, OS discs®, ARS Safe-Tipped Bur Kit® and Ortho-Strips Set®) that are currently available on the market. Each of the five examination groups comprised 12 randomly selected teeth, while the control group consisted of six teeth. The teeth were placed in an artificial model for each group. The proximal contacts were then resolved by IPP. To allow detection of any surface characteristics, one surface was not further processed after IPP, while the other side was additionally polished. After IPP, the teeth were exposed to a pH-cycling model with alternating phases of demineralization and remineralization. Substance loss was analyzed using optical emission spectrometry. Data were subjected to simple analysis of variance (ANOVA) performed with Tukey's test. Comparison between the groups with and without polishing was conducted using the t test for independent samples. The significance level was set at p Rotor Stripping® system (ARS; 145.34 ± 20.37 μm). In all of the examination groups, subsequent polishing of the surfaces did not significantly reduce the amount of demineralization (polished 119.64 ± 28.61 μm; unpolished 114.16 ± 28.61 μm). No correlation between surface morphology and the degree of susceptibility of human enamel was detected. However, it must be taken into consideration that there was no potential bacterial colonization in this in vitro erosive set-up. Thus, in contrast to previous explanations, the outermost fluorapatite layer and the individual composition of the enamel may have a greater impact on the solubility of the enamel and the amount of enamel loss after IPP than

  7. Sterile neutrino dark matter production

    Science.gov (United States)

    Gorbunov, Dmitry

    2017-10-01

    Sterile neutrinos provide active neutrinos with masses and mixing, and hence is one of the well-motivated candidate for dark matter. We discuss the sterile neutrino production mechanisms operating in the early Universe and show that additional scalar coupled to sterile neutrino can significantly change the situation, making moderate sterile-neutrino mixing and small sterile neutrino masses consistent with current cosmological and astrophysical bounds. Further searches for a narrow line in galactic X-rays and even direct searches for keV-scale sterile neutrinos in particle physics experiments can probe the suggested setup.

  8. Sterilization validation for medical compresses at IRASM multipurpose irradiation facility

    Science.gov (United States)

    Alexandru, Mioara; Ene, Mihaela

    2007-08-01

    In Romania, IRASM Radiation Processing Center is the unique supplier of radiation sterilization services—industrial scale (ISO 9001:2000 and ISO 13485:2003 certified). Its Laboratory of Microbiological Testing is the sole third party competent laboratory (GLPractice License, ISO 17025 certification in progress) for pharmaceutics and medical devices as well. We here refer to medical compresses as a distinct category of sterile products, made from different kind of hydrophilic materials (cotton, non-woven, polyurethane foam) with or without an impregnated ointment base (paraffin, plant extracts). These products are included in the class of medical devices, but for the sterilization validation, from microbiological point of view, there are important differences in testing method compared to the common medical devices (syringes, catheters, etc). In this paper, we present some results and practical solutions chosen to perform a sterilization validation, compliant with ISO 11137: 2006.

  9. Sterilization validation for medical compresses at IRASM multipurpose irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Alexandru, Mioara [Horia Hulubei National Institute of Physics and Nuclear Engineering, IRASM Radiation Processing Centre (Romania)]. E-mail: m_alexandru@irasm.ro; Ene, Mihaela [Horia Hulubei National Institute of Physics and Nuclear Engineering, IRASM Radiation Processing Centre (Romania)

    2007-08-15

    In Romania, IRASM Radiation Processing Center is the unique supplier of radiation sterilization services-industrial scale (ISO 9001:2000 and ISO 13485:2003 certified). Its Laboratory of Microbiological Testing is the sole third party competent laboratory (GLPractice License, ISO 17025 certification in progress) for pharmaceutics and medical devices as well. We here refer to medical compresses as a distinct category of sterile products, made from different kind of hydrophilic materials (cotton, non-woven, polyurethane foam) with or without an impregnated ointment base (paraffin, plant extracts). These products are included in the class of medical devices, but for the sterilization validation, from microbiological point of view, there are important differences in testing method compared to the common medical devices (syringes, catheters, etc). In this paper, we present some results and practical solutions chosen to perform a sterilization validation, compliant with ISO 11137: 2006.

  10. MINOS Sterile Neutrino Search

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, David Jason [Univ. College London, Bloomsbury (United Kingdom)

    2009-02-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the v μ→ Vτ transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling ~2.5 x 1020 protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.

  11. Sterilization of Native Americans

    Science.gov (United States)

    Dillingham, Brint

    1977-01-01

    The U.S. State Department's Agency for International Development (AID) is spending more than $143 million this year for population control measures in over 70 nations around the world and it is estimated that as much as $10 million was spent in one year for surgical sterilization procedures. (JC)

  12. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  13. Effects of gamma radiation ({sup 60}Co) on the main physical and chemical properties of health care packaging and their compounds paper and multilayer plastic film, used for health products sterilization; Efeitos da radiacao gama (Cobalto-60) nas principais propriedades fisicas e quimicas da embalagens compostas por papel grau cirurgico e filme plastico laminado, destinadas a esterilizacao de produtos para saude

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Karina Meschini Batista Geribello

    2013-07-01

    Gamma radiation is one of the technologies applied for the sterilization of packaging systems containing products for health. During sterilization process it is critical that the properties of packages are maintained. In this study two samples of commercial pouch packaging comprised of surgical grade paper on one side and the other side multilayer plastic film were irradiated with gamma rays. The following doses were applied 25 kGy (1,57 kGy/h) and 50 kGy (1,48 kGy/h). One packaging sample was paper formed by softwood fibers and multilayer plastic film based on poly(ethylene terephthalate) (PET)/polyethylene (PE). The second type of paper sample was made by a mixture of softwood and hardwood fibers and multilayer plastic film based on polyethylene terephthalate (ethylene) (PET)/polypropylene (PP). The effects of radiation on the physical and chemical properties of papers and multilayer plastic films, as well as the properties of the package were studied. The paper was the more radiation sensitive among the studied materials and radiation effects were more pronounced at brightness, pH, tearing resistance, bursting strength and tensile strength. Nonetheless, worst comparatively effects were noted on the sample made by a mixture of softwood and hardwood fibers. The porosity of paper was enhanced by 50 kGy. In the case of plastic films, radiation effects on tensile strength was the most pronounced property for both samples. In the case of the packaging the sealing resistance decreased with radiation. The effects observed for the treatment at 50 kGy were more pronounced when compared to 25 kGy. This last is the dose which is usually applied to sterilize health products. A dosimetry study was performed during irradiation at 25 kGy, 40 kGy and 50 kGy and its importance may be reported by the average dose variation 20 %. (author)

  14. Efficacy of various topical agents to prevent enamel demineralization

    Directory of Open Access Journals (Sweden)

    Priska Lestari Hendrawan

    2011-09-01

    Full Text Available Background: Enamel demineralization is a common and undesirable side effect of fixed appliance orthodontic treatment. Many sudies showed that the prevalence varied between 2–96%. There are many ways to prevent demineralization and increased remineralization such as oral hygiene instruction and by topical application such as acidulated phosphate fluor (APF casein phospo peptide-amorphous calcium phosphate (CPP-ACP, casein phospo peptide-amorphous calcium phosphate plus (CPP-ACPF. Purpose: The purpose of this in-vitro study was to evaluate the efficacy of various topical agents to prevent enamel demineralization. Methods: Fourty extracted human premolars were allocated to 1 of 4 groups: 1.23% APF gel; 10% CPP-ACP paste; 10% CPP-ACPF paste; and untreated control. All samples were subjected to pH cycling treatment for 12 days through a daily procedure of demineralization solution with pH 4 for 6 hours and remineralization solution with pH 7 for 18 hours. Microhardness testing were done before and after pH cycling and the delta hardness values were determined. Results: APF, CPP-ACP and CPP-ACPF application significantly prevent lowering of enamel microhardness value compared with untreated control group. Kruskal-Wallis, ANOVA, Mann-Whitney U, Tukey and Bonferroni Post-Hoc multiple comparison test showed significant difference between mean delta microhardness value of CPP-ACPF and CPP-ACP group with APF group, but there is no significant difference between mean delta microhardness value of CPP-ACPF and CPP-ACP group. Conclusion: APF, CPP-ACP and CPP-ACPF prevent enamel demineralization. CPP-ACP and CPP-ACPF prevent demineralization more than APF.Latar belakang: Demineralisasi email merupakan efek samping negatif yang sering dijumpai pada perawatan ortodontik cekat. Beberapa penelitian menyatakan bahwa prevalensinya bervariasi 2–96 persen. Ada beberapa cara untuk mencegah demineralisasi dan meningkatkan remineralisasi, misalnya dengan instruksi

  15. Behaviour of AISI 316L Steel Exposed to Demineralized Water

    Directory of Open Access Journals (Sweden)

    Kožuh, S.

    2009-06-01

    Full Text Available The subject of investigation was the passivation of AISI 316L austenitic stainless steel. The effectiveness of various passivation media was tested by means of the potentiodynamic polarization technique. Potentiodynamic polarization was carried out in demineralized water before and after passivation treatment. Comparative analysis of the potentiodynamic curves for different passivation media showed that the best protection of the steel surface was provided by a HNO3 solution, φ= 6.0 %, containing CuSO4 · 5H2O, w = 2.0 %. The satisfactory protective properties were found to agree with the high value of the pitting potential.

  16. Effect of sterilization process on surface characteristics and biocompatibility of pure Mg and MgCa alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.L.; Zhou, W.R.; Wu, Y.H.; Cheng, Y. [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); State Key Laboratory for Turbulence and Complex System, College of Engineering, Peking University, Beijing 100871 (China); Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2013-10-15

    The aim of this work was to investigate the effect of various sterilization methods on surface characteristics and biocompatibility of MgCa alloy, with pure Mg as a comparison, including steam autoclave sterilization (SA), ethylene oxide steam sterilization (EO), glutaraldehyde sterilization (GD), dry heat sterilization (DH) and Co60 γ ray radiation sterilization (R) technologies. The surface characterizations were performed by environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, water contact angle and surface free energy measurement, whereas the cytotoxicity and hemocompatibility were evaluated by cellular adhesive experiment, platelet adhesion and hemolysis test. The results showed that the five sterilization processes caused more changes on the surface of MgCa alloy than that on the surface of pure Mg. The GD sterilization caused the most obvious changes on the surface of the pure Mg, and the SA sterilization made the largest alteration on the MgCa alloy surface. The GD and DH sterilization processes could cause increases on surface free energy for both pure Mg and MgCa alloys, while the other three sterilization processes reduced the surface free energy. The DH and GD sterilization processes caused the least alteration on the cell adhesion on pure Mg surface, whereas the EO sterilization performed the greatest impact on the cell adhesion on the Mg–Ca alloy surface. The hemolysis percentage of pure Mg and MgCa alloys were reduced by SA sterilization, meanwhile the other four sterilization processes increased their hemolysis percentages significantly, especially for the EO sterilization. - Highlights: • The effect of sterilization on surface chemistry and biocompatibility was studied. • Sterilization caused more surface changes on MgCa alloy than pure Mg. • Co60 γ ray radiation is the most appropriate sterilization process.

  17. Process variation in electron beam sterilization

    Science.gov (United States)

    Beck, Jeffrey A.

    2012-08-01

    The qualification and control of electron beam sterilization can be improved by the application of proven statistical analysis techniques such as Analysis of Variance (ANOVA) and Statistical Tolerance Limits. These statistical techniques can be useful tools in: Locating and quantifying the minimum and maximum absorbed dose in a product. Estimating the expected process maximum dose, given a minimum sterilizing dose. Setting a process minimum dose target, based on an allowance for random measurement and process variation. Determining the dose relationship between a reference dosimeter and process minimum and maximum doses. This study investigates and demonstrates the application of these tools in qualifying electron beam sterilization, and compares the conclusions obtained with those obtained using practices recommended in Association for the Advancement of Medical Instrumentation (AAMI) TIR 29 (2002) Guide for Process Control in Radiation Sterilization. The study supports the following conclusions for electron beam processes: ANOVA is a more effective tool for evaluating the equivalency of absorbed doses than methods suggested in AAMI TIR29 (2002). Process limits computed using statistical tolerance limits more accurately reflect actual process variability than the AAMI method, which applies +/-2 sample standard deviations (s) regardless of sample size. The use of reference dose ratios lends itself to qualification using statistical tolerance limits. The current AAMI recommended approach may result in an overly optimistic estimate of the reference dose adjustment factor, as it is based on application of +/-2(s) tolerances regardless of sample size.

  18. EFFECTS OF FLUORIDE AND METHANEHYDROXYDIPHOSPHATE ON ENAMEL AND ON DENTIN DEMINERALIZATION

    NARCIS (Netherlands)

    ARENDS, J; CHRISTOFFERSEN, J; BUSKES, JAKM; RUBEN, J

    1992-01-01

    The aim of this article was to investigate the effects of methanehydroxydiphosphonate (MHDP) and fluoride (F) separately and combined, on the demineralization process in enamel and in dentine under constant composition conditions. The demineralization was carried out in solutions containing 3 mM

  19. 21 CFR 880.6850 - Sterilization wrap.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sterilization wrap. 880.6850 Section 880.6850 Food... § 880.6850 Sterilization wrap. (a) Identification. A sterilization wrap (pack, sterilization wrapper... sterilized by a health care provider. It is intended to allow sterilization of the enclosed medical device...

  20. The effect of the radio-protective agents ethanol, trimethylglycine, and beer on survival of X-ray-sterilized male Aedes aegypti

    OpenAIRE

    Rodriguez, Stacy D; Brar, Ramaninder K; Drake, Lisa L; Drumm, Hannah E; Price, David P; Hammond, John I; Urquidi, Jacob; Hansen, Immo A

    2013-01-01

    Background Sterile Insect Technique (SIT) has been successfully implemented to control, and in some cases, eradicate, dipteran insect populations. SIT has great potential as a mosquito control method. Different sterilization methods have been used on mosquitoes ranging from chemosterilization to genetically modified sterile male mosquito strains; however, sterilization with ionizing radiation is the method of choice for effective sterilization of male insects for most species. The lack of gen...

  1. Effect of dentinal tubule orientation on the modulus of elasticity of resin-infiltrated demineralized dentin.

    Science.gov (United States)

    Pongprueksa, Pong; Senawongse, Pisol; Vongphan, Nataya

    2014-01-01

    The effect of tubule orientation of dentin on the elastic modulus of resin-infiltrated dentin was evaluated. Rectangular cylindricalshaped dentin specimens with their long axis parallel to and perpendicular to dentinal tubules were prepared from extracted premolars. Twenty-five mineralized specimens of each orientation were evaluated. The remaining specimens were then demineralized. The demineralized specimens and the demineralized following by infiltration with one of these adhesives; Optibond Solo Plus, Single Bond 2 or Prime & Bond NT, from each orientation were evaluated (25 specimens per group). The tubular orientation only affected the elastic modulus of mineralized dentin. The highest elastic modulus was observed for the mineralized dentin when the tensile force was applied parallel to the direction of tubules. The elastic modulus of demineralized dentin was the lowest. The adhesive resins increased the elastic modulus of demineralized dentin, but the differences among the three were insignificant.

  2. Assessing the environmental impacts of using demineralized coal for electricity generation

    DEFF Research Database (Denmark)

    Ryberg, Morten; Owsianiak, Mikolaj; Laurent, Alexis

    2014-01-01

    The energy sector is the source of two-thirds of global greenhouse-gas emissions, and is the main target ofclimate policies among authorities and governments. The share of fossil coals (hard coal and lignite) in world total net electricity generation is 40% in 2010. Demineralization or ash removal...... generation will affect the environment.The results showed that demineralization in some cases were beneficial for regional impacts such asparticulate matter formation because emission of particles and SO2 were reduce. In the contrary globalimpacts such as climate change did not benefit from demineralization...... because of the large energy use forrunning the demineralization process. Local and regional environmental impacts were shown to improve from demineralization for low ranking coals or lignite where the ash content is above ≈25 % and the carboncontent is less than ≈50 %. Overall, it can be concluded...

  3. Use of gamma radiation for preparation of nutrient culture media

    Energy Technology Data Exchange (ETDEWEB)

    Speranskaya, I.D.; Tumanyan, M.A.; Mironova, L.L.

    1977-01-01

    A technique was developed for sterilization of nutrient culture media using ..gamma..-radiation. For this purpose, dry preparations were exposed to 3 to 6 Mrad radiation, then dissolved in sterile distilled water. The quality of media and solutions thus obtained is as good as that of preparations sterilized by filtration. The advantage of the proposed sterilization method is that liquid media can be rapidly prepared and dry sterile media can be stored at room temperature for long periods of time.

  4. Sterilization by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Adir Jose; Mansano, Ronaldo Domingues; Andreoli Pinto, Terezinha de Jesus; Ruas, Ronaldo; Silva Zambon, Luis da; Silva, Monica Valero da; Verdonck, Patrick Bernard

    2004-07-31

    The use of polymeric medical devices has stimulated the development of new sterilization methods. The traditional techniques rely on ethylene oxide, but there are many questions concerning the carcinogenic properties of the ethylene oxide residues adsorbed on the materials after processing. Another common technique is the gamma irradiation process, but it is costly, its safe operation requires an isolated site and it also affects the bulk properties of the polymers. The use of a gas plasma is an elegant alternative sterilization technique. The plasma promotes an efficient inactivation of the micro-organisms, minimises the damage to the materials and presents very little danger for personnel and the environment. Pure oxygen reactive ion etching type of plasmas were applied to inactivate a biologic indicator, the Bacillus stearothermophilus, to confirm the efficiency of this process. The sterilization processes took a short time, in a few minutes the mortality was complete. In situ analysis of the micro-organisms' inactivating time was possible using emission spectrophotometry. The increase in the intensity of the 777.5 nm oxygen line shows the end of the oxidation of the biologic materials. The results were also observed and corroborated by scanning electron microscopy.

  5. A new generation of X ray irradiators for insect sterilization.

    Science.gov (United States)

    Mastrangelo, T; Parker, A G; Jessup, A; Pereira, R; Orozco-Dávila, D; Islam, A; Dammalage, T; Walder, J M M

    2010-02-01

    Recent fears of terrorism have provoked an increase in delays and denials of transboundary shipments of radioisotopes. This represents a serious constraint to sterile insect technique (SIT) programs around the world as they rely on the use of ionizing radiation from radioisotopes for insect sterilization. To validate a novel X ray irradiator, a series of studies on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) were carried out, comparing the relative biological effectiveness (RBE) between X rays and traditional gamma radiation from 60Co. Male C. capitata pupae and pupae of both sexes of A. fraterculus, both 24-48 h before adult emergence, were irradiated with doses ranging from 15 to 120 Gy and 10-70 Gy, respectively. Estimated mean doses of 91.2 Gy of X and 124.9 Gy of gamma radiation induced 99% sterility in C. capitata males. Irradiated A. fraterculus were 99% sterile at approximately 40-60 Gy for both radiation treatments. Standard quality control parameters and mating indices were not significantly affected by the two types of radiation. The RBE did not differ significantly between the tested X and gamma radiation, and X rays are as biologically effective for SIT purposes as gamma rays are. This work confirms the suitability of this new generation of X ray irradiators for pest control programs that integrate the SIT.

  6. Effects of ionizing radiations on bacterial endotoxins: Comparison between gamma radiations and accelerated electrons

    Science.gov (United States)

    Guyomard, S.; Goury, V.; Darbord, J. C.

    Determinations of the effect of radiation sterilization processing on purified endotoxins, in aqueous solution or on dried support, are reported. These observations allow us to accept gamma radiations for sterilization of parenteral devices with an estimated probability of existence of non apyrogenic items, based upon a similar definition of the usual Sterility Assurance Level SAL = 10 -6).

  7. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  8. Osteoinductivity of Demineralized Bone Matrix Is Independent of Donor Bisphosphonate Use

    Science.gov (United States)

    Schwartz, Zvi; Hyzy, Sharon L.; Moore, Mark A.; Hunter, Shawn A.; Ronholdt, Chad J.; Sunwoo, MoonHae; Boyan, Barbara D.

    2011-01-01

    Background: Demineralized bone matrix is commonly used as a bone graft substitute, either alone or to supplement an osteoconductive material, because of its osteoinductive properties. The aging of the population has led to an increase in the number of prospective donors of demineralized bone matrix who have taken bisphosphonates to prevent osteoclast-mediated bone resorption. The aim of this study was to determine whether oral bisphosphonate usage affects the osteoinductivity of demineralized bone matrix from donors. Methods: Sex-matched and age-matched pairs of samples were provided by four tissue banks (three or four pairs per bank). Demineralized bone matrix donors without bisphosphonate treatment had a mean age (and standard deviation) of 69.1 ± 2.5 years, and donors with bisphosphonate treatment had a mean age of 68.9 ± 2.0 years. Each pair included one donor known to have taken bisphosphonates and one who had not taken bisphosphonates. Demineralized bone matrix previously confirmed as osteoinductive was the positive control, and heat-inactivated demineralized bone matrix was the negative control. Demineralized bone matrix incubated with 1 mL of phosphate-buffered saline solution containing 0, 0.002, 2.0, or 2000 ng/mL of alendronate was also tested. Gelatin capsules containing 15 mg of demineralized bone matrix were implanted bilaterally in the gastrocnemius muscle of male nude mice (eight implants per group). The mice were killed thirty-five days after implantation, and hind limbs were recovered and processed for histological analysis. Osteoinductivity was measured with use of a qualitative score and by histomorphometry. Results: Nine of fifteen samples from donors who had had bisphosphonate treatment and ten of fifteen samples from patients who had not had bisphosphonate treatment were osteoinductive. Qualitative mean scores were comparable (1.7 ± 0.4 for those without bisphosphonates and 1.9 ± 0.7 for those with bisphosphonates). Osteoinductive

  9. Sterrad Sterilization System: a new technology for instrument sterilization.

    Science.gov (United States)

    Jacobs, P; Kowatsch, R

    1993-02-01

    The Sterrad Sterilization System by Advanced Sterilization Products (ASP) exploits the synergism between peroxide and low temperature gas plasma (an excited or ionized gas) to rapidly destroy microorganisms (Figure 1). At the completion of the sterilization process based on this technology, no toxic residues remain on the sterilized items. The technology is particularly suited to the sterilization of heat and moisture sensitive instruments since process temperatures do not exceeded about 50 degrees C (140 degrees F) and sterilization occurs in a low moisture environment. Total process time is about one hour. The efficacy of the process has been demonstrated against a broad spectrum or microorganisms and on a large number of substrates used in medical instruments.

  10. Optical Barrier for Microbiological Control after a Sterilization Process

    Directory of Open Access Journals (Sweden)

    Bruno Pereira de Oliveira

    2017-06-01

    Full Text Available An optical barrier (OB may eliminate the entrance of aerosol generated by clinical procedures in sterilization devices. The OB is a new alternative for sterilizing medical and dental instruments. The objective of the study was to evaluate the action of the OB on the entrance of bacteria into an autoclaving system and to correlate the time and distance of exposure. To test the configuration of the device, we used Escherichia coli. A lamp utilized in this instrument was low pressure with a wavelength around 254nm. A homogenous distribution of light around the door was observed by the Inventor 2015 software. Microbiological tests showed efficient bacterial elimination at a distance of 8cm from OB. The results show that the use of the OB radiation for 30 minutes guarantees the non-entry of microorganisms into the sterilized environment. The use of the OB may be recommended to maintain the surface of sterile materials for long periods of time.

  11. Effects of Fluoride on Two Chemical Models of Enamel Demineralization

    Directory of Open Access Journals (Sweden)

    Ollie Yiru Yu

    2017-10-01

    Full Text Available This study evaluated the effects of fluoride on subsurface enamel demineralization induced by two commonly used chemical models. Forty-eight enamel blocks were demineralized at pH = 5.0 by an acetate buffer (Group 1, a lactate buffer (Group 2, an acetate buffer with 0.02 ppm fluoride (Group 3 and a lactate buffer with 0.02 ppm fluoride (Group 4 at 25 °C for 3 weeks. The surface destruction percentage (SDP, mineral loss and lesion depth of the blocks were studied using micro-computed tomography. An elemental analysis of the enamel surface was evaluated using an energy-dispersive X-ray spectroscopy. Surface micro-hardness was determined by the Knoop Hardness Test. The mean lesion depth of Groups 1 through 4 were 134.1 ± 27.2 μm, 96.1 ± 16.5 μm, 97.5 ± 22.4 μm and 91.1 ± 16.2 μm, respectively (p < 0.001; group 1 > 2, 3 > 4. The SDPs of groups 1 through 4 were 7.8 ± 8.93%, 0.71 ± 1.6%, 0.36 ± 1.70% and 1.36 ± 2.94% (p < 0.001; group 1 > 2, 3, 4. The fluoride in mean weight percentages of groups 1 through 4 were 1.12 ± 0.24%, 1.10 ± 0.20%, 1.45 ± 0.40% and 1.51 ± 0.51%, respectively (p < 0.001; group 3, 4 > 1, 2. The mean Knoop hardness values of groups 1 through 4 were 27.5 ± 13.3, 39.7 ± 19.3, 73.6 ± 44.2 and 91.0 ± 57.2, respectively (p < 0.001; group 4 > 3 > 2 > 1. The chemical model using an acetate buffer solution created significantly deeper zones of subsurface demineralization on enamel than the lactate buffer solution. An acetate buffer may damage the enamel surface, but the surface damage can be prevented by adding fluoride.

  12. Cross-linked demineralized dentin maintains its mechanical stability when challenged by bacterial collagenase.

    Science.gov (United States)

    Xu, Changqi; Wang, Yong

    2011-02-01

    The molecular structure, weight loss, and mechanical properties of demineralized dentin of noncrosslinked/crosslinked by glutaraldehyde (GA) were investigated when being challenged by bacterial collagenase solution over time in this study. Raman spectra proved that crosslinking occurred in demineralized dentin matrices after being treated with GA. Meanwhile, the weight of the cross-linked demineralized dentin matrices did not change after being challenged by bacterial collagenase solution up to 1 week. However, the weight of noncross-linked dentin collagen fell by almost 45% after degradation for 5 h, and up to 100% after 19 h. The tensile strength of demineralized dentin matrices did not show a significant change after being crosslinked, while the stiffness of demineralized dentin matrices showed more improvement than that of noncross-linked collagen. The toughness of demineralized dentin matrices decreased slightly after being crosslinked. Importantly, neither the tensile strength of GA-cross-linked demineralized dentin nor its stiffness changed over time in either control buffer or collagenase solution compared with that of noncross-linked controls. These results suggested that improving the degree of crosslinking in dentin collagen could be one method to inhibit its biodegradation and further to increase the durability of dental restorations. Copyright © 2010 Wiley Periodicals, Inc.

  13. Effects of Ion-Releasing Tooth-Coating Material on Demineralization of Bovine Tooth Enamel

    Directory of Open Access Journals (Sweden)

    Koji Kawasaki

    2014-01-01

    Full Text Available We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF and electron probe microanalyzer (EPMA measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating.

  14. Radiation sterilization of tissue allografts: A review

    OpenAIRE

    Singh, Rita; Singh, Durgeshwer; Singh, Antaryami

    2016-01-01

    Tissue substitutes are required in a number of clinical conditions for treatment of injured and diseased tissues. Tissues like bone, skin, amniotic membrane and soft tissues obtained from human donor can be used for repair or reconstruction of the injured part of the body. Allograft tissues from human donor provide an excellent alternative to autografts. However, major concern with the use of allografts is the risk of infectious disease transmission. Therefore, tissue allografts should be ste...

  15. Sterilization in the United States

    Science.gov (United States)

    Bartz, Deborah; Greenberg, James A

    2008-01-01

    Unintended pregnancies are expensive for patients and for society in terms of medical costs, the cost of caring for more children, and the cost to personal and professional goals. Sterilization is the most common contraceptive method utilized by couples in the United States. Given technological advances over the past few decades, male and female surgical sterilization has become a safe, convenient, easy, and highly effective birth control method for the long term. This article reviews current male and female sterilization options. PMID:18701927

  16. Sterile neutrinos: fact or fiction?

    Science.gov (United States)

    Huber, Patrick

    2017-01-01

    In this talk I will critically review some of the anomalies which in combination could point to the existence of a eV-scale sterile neutrino. Each of these anomalies is well below the 5 sigma level individually and may have explanations besides sterile neutrinos. At the same time each anomaly requires a separate explanation if it is not caused by a sterile neutrino. To further complicate the gpicture, some data sets are in mutual disagreement.

  17. Near-infrared imaging of demineralization under sealants

    Science.gov (United States)

    Tom, Henry; Simon, Jacob C.; Chan, Kenneth H.; Darling, Cynthia L.; Fried, Daniel

    2014-07-01

    Previous studies have shown that near-infrared (NIR) reflectance and transillumination imaging can be used to acquire high contrast images of early caries lesions and composite restorative materials. The aim of the study was to determine the optimum NIR wavelengths for imaging demineralized areas under dental sealants. Fifteen natural human premolars and molars with occlusal lesions were used in this in vitro study. Images before and after application of sealants were acquired using NIR reflectance and NIR transillumination at wavelengths of 1300, 1460, and 1500 to 1700 nm. Images were also acquired using polarization sensitive optical coherence tomography (OCT) for comparison. The highest contrast for NIR reflectance was at 1460 nm and 1500 to 1700 nm. These NIR wavelengths are coincident with higher water absorption. The clear Delton sealant investigated was not visible in either copolarization or cross-polarization OCT images. The wavelength region between 1500 and 1700 nm yielded the highest contrast of lesions under sealants for NIR reflectance measurements.

  18. Microstructural analysis of demineralized primary enamel after in vitro toothbrushing

    Directory of Open Access Journals (Sweden)

    Neves Aline de Almeida

    2002-01-01

    Full Text Available The aim of this study was to investigate, in vitro, the morphological characteristics of demineralized primary enamel subjected to brushing with a dentifrice with or without fluoride. In order to do so, 32 enamel blocks were divided in 4 different groups containing 8 blocks each. They were separately immersed in artificial saliva for 15 days. The experimental groups were: C - control; E - submitted to etching with 37% phosphoric acid gel (30 s; EB - submitted to etching and brushing 3 times a day with a non-fluoridated dentifrice; EBF = submitted to etching and brushing 3 times a day with a fluoridated dentifrice. The toothbrushing force was standardized at 0.2 kgf and 15 double strokes were performed on each block. After the experimental period, the samples were prepared and examined under SEM. The control group (C showed a smooth surface, presenting scratches caused by habitual toothbrushing. The etched samples (E exhibited different degrees of surface disintegration, but the pattern of acid etching was predominantly the type II dissolution. The brushed surfaces were smooth, with elevations which corresponded to the exposure of Tomes? process pits and depressions which corresponded to interrod enamel. Particles resembling calcium carbonate were found in the most protected parts of the grooves. No morphological differences were observed between brushing with fluoridated (EBF and non-fluoridated (EB dentifrice. The results suggest that the mechanical abrasion caused by brushing demineralized enamel with dentifrice smoothes the rough etched surface, and the presence of fluoride does not cause morphological modifications in this pattern.

  19. New disinfection and sterilization methods.

    Science.gov (United States)

    Rutala, W A; Weber, D J

    2001-01-01

    New disinfection methods include a persistent antimicrobial coating that can be applied to inanimate and animate objects (Surfacine), a high-level disinfectant with reduced exposure time (ortho-phthalaldehyde), and an antimicrobial agent that can be applied to animate and inanimate objects (superoxidized water). New sterilization methods include a chemical sterilization process for endoscopes that integrates cleaning (Endoclens), a rapid (4-hour) readout biological indicator for ethylene oxide sterilization (Attest), and a hydrogen peroxide plasma sterilizer that has a shorter cycle time and improved efficacy (Sterrad 50).

  20. Principles of Sterilization of Mars Descent Vehicle Elements

    Science.gov (United States)

    Trofimov, Vladislav; Deshevaya, Elena; Khamidullina, N.; Kalashnikov, Viktor

    Due to COSPAR severe requirements to permissible microbiological contamination of elements of down-to-Mars S/C as well as complexity of their chemical composition and structure the exposure of such S/C elements to antimicrobial treatment (sterilization) at their integration requires application of a wide set of methods: chemical, ultraviolet, radiation. The report describes the analysis of all the aspects of applicable methods of treatment for cleaning of elements’ surfaces and inner contents from microbiota. The analysis showed that the most important, predictable and controllable method is radiation processing (of the elements which don’t change their properties after effective treatment). The experience of ionizing radiation application for sterilization of products for medicine, etc. shows that, depending on initial microbial contamination of lander elements, the required absorbed dose can be within the range 12 ÷ 35 kGr. The analysis of the effect of irregularity of radiation absorption in complex structure elements to the choice of radiation methodology was made and the algorithm of the choice of effective conditions of radiation treatment and control of sterilization efficiency was suggested. The important phase of establishing of the effective condition of each structure element treatment is experimental verification of real microbiological contamination in terms of S/C integration, contamination maximum decrease using another cleaning procedures (mechanical, chemical, ultraviolet) and determination of radiation resistance of spore microorganisms typical for the shops of space technology manufacturing and assembling. Proceeding from three parameters (irregularity of radiation absorption in a concrete element, its initial microbial contamination and resistance of microorganisms to the effect of radiation) the condition of the packed object sterilization is chosen, the condition that prevents secondary contamination, ensures given reliability of the

  1. Effect of demineralization on the physiochemical structure and thermal degradation of acid treated indigenous rice husk

    Directory of Open Access Journals (Sweden)

    Aslam Umair

    2016-09-01

    Full Text Available Energy generation from biomass presents some serious problems like slagging, fouling and corrosion of boilers. To address these problems, demineralization of biomass is performed using different leaching agents. This study is focused on determining the influence of leaching agents and leaching time on the physiochemical structure of rice husk during demineralization. Dilute (5% wt solutions of HCl and H2SO4 were used for the demineralization of rice husk separately with leaching time of 15, 60 and 120 minutes. It is shown that H2SO4 exhibited higher removal of alkali and alkaline earth metals (AAEM comparatively as depicted by the 34.2% decrease in ash content along with an increase of 7.10% in the heating value. The acid has been seen to induce more notable changes in physiochemical structure as depicted by the FTIR spectra and SEM micrographs. The thermal degradation behavior of the demineralized rice husk has also been reported.

  2. Osteoinductive potential of demineralized rat bone increases with increasing donor age from birth to adulthood

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E

    1998-01-01

    Demineralized allogenic bone implanted in the subcutis or muscle of rodents causes formation of heterotopic bone by osteoinduction. The osteoinductive response may be weaker in primates than in rodents. It was suggested that the osteoinductive response of demineralized bone for clinical use could...... be enhanced by using young donors, because studies have indicated that the osteoinductive response is reduced in demineralized bone of old versus young donors. However, these findings may not represent a gradual decline in the osteoinductive property of bone matrix throughout the life span. We evaluated...... quantitatively, by uptake of strontium 85, the osteoinductive effect of demineralized bone matrix from newborn, 8-week-old (adolescent), and 8-month-old (adult) male Wistar rats implanted in the abdominal muscles of 8-week-old male Wistar rats. The osteoinductive response increased significantly with increasing...

  3. Effect of starch and sucrose on dental biofilm formation and on root dentine demineralization

    National Research Council Canada - National Science Library

    Aires, C P; Del Bel Cury, A A; Tenuta, L M A; Klein, M I; Koo, H; Duarte, S; Cury, J A

    2008-01-01

    The cariogenicity of starch alone or in combination with sucrose is controversial and the effect on dentine demineralization and on the dental biofilm formed has not been explored under controlled conditions...

  4. Ectopic pregnancy after tubal sterilization.

    Directory of Open Access Journals (Sweden)

    Shah J

    1991-01-01

    Full Text Available We report 13 cases of ectopic pregnancy following tubal ligation out of 287 ectopic pregnancies seen during a six year period (1984-1989. These findings suggest that tubal sterilization does not invariably confer infertility. Ectopic pregnancy must not be disregarded in women who have undergone tubal ligation, especially if two or more years have elapsed since the sterilization.

  5. Sterilization of Extracted Human Teeth.

    Science.gov (United States)

    Pantera, Eugene A., Jr.; Schuster, George S.

    1990-01-01

    At present, there is no specific recommendation for sterilization of extracted human teeth used in dental technique courses. The purpose of this study was to determine whether autoclaving would be effective in the sterilization of extracted teeth without compromising the characteristics that make their use in clinical simulations desirable. (MLW)

  6. Electrolytic silver ion cell sterilizes water supply

    Science.gov (United States)

    Albright, C. F.; Gillerman, J. B.

    1968-01-01

    Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water.

  7. An alternative treatment option for a bony defect from large odontoma using recycled demineralization at chairside

    OpenAIRE

    Lee, JuHyon; Lee, Eun-Young; Park, Eun-Jin; Kim, Eun-Suk

    2015-01-01

    Odontoma is the most common odontogenic benign tumor, and the treatment of choice is generally surgical removal. After excision, bone grafts may be necessary depending on the need for further treatment, or the size and location of the odontoma. Although the osteogenic capacity of a demineralized tooth was verified as early as 1967 by Urist and many other investigators, the cumbersome procedure, including a long demineralization time, may be less than comfortable for clinicians. A modified ult...

  8. Effect of canine cortical bone demineralization on osteogenic differentiation of adipose-derived mesenchymal stromal cells

    Directory of Open Access Journals (Sweden)

    Kwangrae Jo

    2017-08-01

    Full Text Available Demineralized bone allografts and mesenchymal stromal cells have been used to promote bone regeneration. However, the degree to which cortical bone should be demineralized for use in combination with adipose-derived mesenchymal stromal cells (Ad-MSCs remains to be clarified. In this study, the in vitro osteogenic ability of Ad-MSCs on allografts was investigated in relation to the extent of demineralization. Three treatment groups were established by varying exposure time to 0.6 N HCL: partially demineralized (PDB; 12 h, fully demineralized (FDB; 48 h, and non-demineralized bone (NDB; 0 h, as a control. Allografts were prepared as discs 6 mm in diameter for in vitro evaluation, and their demineralization and structure were evaluated by micro-computed tomography and scanning electron microscopy. Ad-MSC adhesion and proliferation were measured by MTS assay, and osteogenesis-related gene expression was assessed by quantitative reverse transcription polymerase chain reaction. PDB and FDB demineralization rates were 57.13 and 92.30%, respectively. Moreover, Ad-MSC adhesion rates on NDB, PDB, and FDB were 53.41, 60.65, and 61.32%, respectively. Proliferation of these cells on FDB increased significantly after 2 days of culture compared to the other groups (P < 0.05. Furthermore, expression of the osteogenic genes ALP, BMP-7, and TGF-β in the FDB group on culture day 3 was significantly elevated in comparison to the other treatments. Given its biocompatibility and promotion of the osteogenic differentiation of Ad-MSCs, our results suggest that FDB may be a suitable scaffold for use in the repair of bone defects.

  9. Effect of storage on osteoinductive properties of demineralized bone in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E

    1994-01-01

    A requirement for the clinical use of demineralized bone is the possibility of storing the material without loss of its osteoinductive properties. Seventy-five 8-week-old male Wistar rats were randomly assigned to one of five groups of 15 rats each. Lyophilized demineralized allogeneic bone...... uptake of the recovered implants. Storage for 9 months at both temperatures did not affect the osteoinduction, whereas storage for 14 months at both temperatures led to a statistically significant decrease in osteoinduction....

  10. Simultaneous Interferometric Measurement of Corrosive or Demineralizing Bacteria and Their Mineral Interfaces

    Science.gov (United States)

    2009-03-01

    demineralization and corrosion, with repercussions spanning from cavity formation in teeth to pit development on a ship’s hull (1–4, 6–8, 10, 11, 15, 17–20...height on polished mirror steel. Height measurements were highly variable; individual bacteria with no morphological ab- normalities (as determined by...processes, such as the demineralization of tooth enamel by S. mutans lactic acid secretions (6, 9, 20). By directly visualizing real-time height changes in

  11. The effect of Emdogain on ectopic bone formation in tubes of rat demineralized dentin matrix.

    Science.gov (United States)

    Koike, Yoshihiko; Murakami, Satoshi; Matsuzaka, Kenichi; Inoue, Takashi

    2005-10-01

    Emdogain (EMD) is made from enamel matrix proteins (EMPs) from the tooth germ of swine and propylene glycol alginate (PGA) as a matrix. The function of EMD is known to differentiate cells of the dental follicle into cementoblasts. However, little is known about the effect of EMD on mesenchymal cells in other tissue. The purpose of this study was to investigate whether EMD has the ability to induce hard tissue when applied with or without demineralized dentin matrix. Half of the dentin tubes prepared from rat incisors were demineralized by treatment with 0.6 N hydrochloric acid for 3 h. EMD or PGA was injected into the demineralized or non-demineralized dentin tubes, which were then transplanted into rectus abdominis muscles. Untreated dentin tubes were also transplanted as a control. Animals were killed at 7, 14 and 21 days after the implantation. Non-demineralized dentin tubes with or without EMD or PGA did not form any hard tissue. In the demineralized group, chondrogenesis in the PGA groups occurred earlier than in the EMD groups. The expression of vascular endothelial growth factor (VEGF) mRNA in the demineralized group with PGA at day 14 was the highest. The expression of osteopontin and osteocalcin mRNAs was higher in all groups at 21 days compared with 7 or 14 days. These results suggest that neither EMD nor PGA has the ability to induce hard tissue and that EMPs contained within EMD might aggregate on the dentin surface and inhibit the effect of the demineralized dentin matrix.

  12. Female sterilization safe, very effective.

    Science.gov (United States)

    Keller, S

    1997-01-01

    Compared with other contraceptive methods, female sterilization is highly effective and convenient. Furthermore, with more than 150 million users worldwide, it is also the most widely used contraceptive method in the world. Sterilization does not have the side effects associated with most temporary methods, does not interfere with sexual intercourse, and does not require routine follow-up care or prescription refills. However, permanent and involving surgery, sterilization is not appropriate for every woman in need of contraception. Women interested in sterilization should compare the approach with reversible options and be encouraged to choose the method which is most appropriate for their circumstances and needs. Sterilization counseling must be done carefully and may require more time than counseling for other contraceptive methods. Young women are more likely than older women to later regret their decision to adopt a permanent method of fertility control. Long-term effectiveness, risk, restrictions, and contraindications are discussed.

  13. Sterile Endophthalmitis after Intravitreal Injections

    Directory of Open Access Journals (Sweden)

    Joaquín Marticorena

    2012-01-01

    Full Text Available Sterile endophthalmitis appears as an infrequent complication of intravitreal injections and seems to develop mainly in the context of the off-label use of drugs that have not been conceived for intravitreous administration. The aetiology of sterile endophthalmitis, independently of the administered drug, remains uncertain and a multifactorial origin cannot be discarded. Sterile inflammation secondary both to intravitreal triamcinolone acetonide and to intravitreal bevacizumab share many characteristics such as the acute and painless vision loss present in the big majority of the cases. Dense vitreous opacity is a common factor, while anterior segment inflammation appears to be mild to moderate. In eyes with sterile endophthalmitis, visual acuity improves progressively as the intraocular inflammation reduces without any specific treatment. If by any chance the ophthalmologist is not convinced by the sterile origin of the inflammation, this complication must be treated as an acute endophthalmitis because of the devastating visual prognosis of this intraocular infection in the absence of therapy.

  14. Thermalizing Sterile Neutrino Dark Matter

    Science.gov (United States)

    Hansen, Rasmus S. L.; Vogl, Stefan

    2017-12-01

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  15. Thermalizing Sterile Neutrino Dark Matter.

    Science.gov (United States)

    Hansen, Rasmus S L; Vogl, Stefan

    2017-12-22

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  16. A search for sterile neutrinos with the latest cosmological observations

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Lu; Zhang, Jing-Fei [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)

    2017-06-15

    We report the result of a search for sterile neutrinos with the latest cosmological observations. Both cases of massless and massive sterile neutrinos are considered in the ΛCDM cosmology. The cosmological observations used in this work include the Planck 2015 temperature and polarization data, the baryon acoustic oscillation data, the Hubble constant direct measurement data, the Planck Sunyaev-Zeldovich cluster counts data, the Planck lensing data, and the cosmic shear data. We find that the current observational data give a hint of the existence of massless sterile neutrino (as dark radiation) at the 1.44σ level, and the consideration of an extra massless sterile neutrino can indeed relieve the tension between observations and improve the cosmological fit. For the case of massive sterile neutrino, the observations give a rather tight upper limit on the mass, which implies that actually a massless sterile neutrino is more favored. Our result is consistent with the recent result of neutrino oscillation experiment done by the Daya Bay and MINOS collaborations, as well as the recent result of cosmic ray experiment done by the IceCube collaboration. (orig.)

  17. Citotoxicidade de tubos de PVC esterilizados em óxido de etileno após exposição à radiação gama Citotoxicidad de tubos de PVC esterilizados en óxido de etileno luego de exposición a la radiación gamma Cytotoxicity of PVC tubes sterilized in ethylene oxide after gamma radiation exposure

    Directory of Open Access Journals (Sweden)

    Rafael Queiroz de Souza

    2013-04-01

    Full Text Available Materiais esterilizados em raios gama, ao serem re-esterilizados em óxido de etileno (EO, formam substâncias tóxicas? Esta questão norteou o objetivo deste estudo, que foi investigar o potencial efeito citotóxico do PVC esterilizado em radiação gama e re-esterilizado em EO pelo método da difusão em ágar em culturas celulares. Nove tubos de PVC foram submetidos à esterilização em radiação gama e re-esterilizados em EO. Os tubos foram divididos em um total de 81 unidades de análise, que foram testadas de forma a representar as superfícies internas, externas e massa de cada tubo. Concluiu-se que os materiais de PVC esterilizados em Radiação Gama e consecutivamente re-esterilizados em EO não são citotóxicos.Los materiales esterilizados con rayos gama, al ser re-esterilizados en óxido de etileno (EO, ¿forman substancias tóxicas? Esta pregunta orientó el objetivo del presente estudio, que fue investigar el potencial efecto citotóxico del PVC esterilizado en radiación gamma y re-esterilizado en EO por el método de difusión en agar en cultivos celulares. Nueve tubos de PVC fueron sometidos a esterilización por radiación gamma y re-esterilizados en EO. Se les aplicaron en total 81 unidades de análisis, las cuales fueron testeadas de manera tal de representar las superficies internas, externas y la masa de cada tubo. Se concluyó en que los materiales de PVC esterilizados con Radiación Gamma y, posteriormente, con EO, no son citotóxicos.Do materials sterilized using gamma rays become toxic when re-sterilized in ethylene oxide? This question guided the objective of this study, which was to investigate the potential cytotoxic effect of PVC sterilized by gamma radiation and re-sterilized with EO by the agar diffusion method in cell cultures. Nine PVC tubes were subjected to gamma radiation sterilization and were re-sterilized in EO. The tubes were divided into a total of 81 units of analysis that were tested so as to

  18. Conditional sterility in plants

    Science.gov (United States)

    Meagher, Richard B.; McKinney, Elizabeth; Kim, Tehryung

    2010-02-23

    The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

  19. [Sterility in medieval noblemen].

    Science.gov (United States)

    van Eickels, Klaus

    2009-01-01

    The social competence of the medieval nobleman was closely associated with his male sense of honour. One essential aspect of his masculinity was the ability to produce progeny. The childlessness of a good ruler needed special justification, the childlessness of a bad ruler was seen as God's punishment. In terms of canon law, the inability to procreate was irrelevant as long as the marriage could be consummated. Considering the importance of the procreative capacity and its symbolic significance one must ask to what extent it was possible to ascertain sterility in the Middle Ages. In the case of noblemen one can assume that they could obtain certainty about their fertility through their premarital and extramarital intercourse. This might explain why some rulers and nobles accepted a childless marriage without deeming it necessary to take another wife (or plan their itinerary in a way that enabled them to produce progeny).

  20. Effects of gamma radiation on the sterility and behavioral quality of the caribbean fruit fly, Anastrepha suspensa (Loew (Diptera:Tephritidae Efeitos da radiação gama na esterilização e comportamento da mosca-do-caribe, Anastrepha suspensa (Low (Diptera:Tephritidae

    Directory of Open Access Journals (Sweden)

    J.M.M. Walder

    1993-09-01

    Full Text Available Pupae of Anastrepha suspensa (Loew were irradiated 2 days before adult eclosión in an air atmosphere with 15, 20, 25, 30, 50 and 70 Gy of gamma radiation (Co-60. The radiation effects on sterility and other parameters of quality and behavior of males and females of caribfly were established. Males became fully sterile with a dose of 50 Gy and females laid no eggs when exposed to 25 Gy. Radiation had no significant effect on adult eclosion, sex ratio, flight ability and irritability, but female mortality was affected significantly by radiation, showing higher survival rates in low dosage treatments. The mating behavior of the males was reduced significantly by increasing the radiation doses.Pupas de Anastrepha suspensa (Loew foram irradiadas dois dias antes da emergência dos adultos em atmosfera de ar com as doses de 15, 20, 25, 30, 50 e 70 Gy de radiação gama (Co-60. Foram avaliados os efeitos da radiação sobre a esterilidade e outros parâmetros de qualidade e comportamento de machos e fêmeas de mosca-do-caribe. Machos tornaram-se totalmente estéreis com uma dose de 50 Gy e as fêmeas não ovipositaram quando expostas a 25 Gy. A radiação não teve efeito significativo sobre a taxa de emergência de adultos, na razão sexual, na habilidade de vôo e na irritabilidade desses insetos. Somente a mortalidade das fêmeas foi afetada significativamente pela radiação, causando unia maior sobrevivência nas dosagens mais baixas. A atividade de acasalamento dos machos foi reduzida significativamente com o incremento da dosagem de radiação.

  1. Incorporation of perforated and demineralized cortical bone allografts. Part I: radiographic and histologic evaluation.

    Science.gov (United States)

    Lewandrowski, K U; Schollmeier, G; Ekkemkamp, A; Uhthoff, H K; Tomford, W W

    2001-01-01

    Massive cortical bone allografts have been found to incorporate slowly into host bone. They are subject to complications such as nonunion, fatigue fracture and infection. In an attempt to improve osteoinduction in cortical bone allografts, laser perforated and partially demineralized cortical bone allografts were orthotopically transplanted into the sheep tibia. In this model, mid-shaft tibial bone allografts from out-bred sheep donor animals were prepared by partial demineralization and drilling of 0.33-mm diameter holes with a pulsed, 2.94-microm wavelength Erbium:Yttrium-Aluminum-Garnet laser. Recipient animals of the same out-bred strain were divided into three groups of eight according to the type of cortical allograft used: group 1, fresh-frozen, no treatment; group 2, laser hole grid; and group 3, laser hole grid and partial demineralization. Plain films were taken in two standard views at monthly intervals. Incorporation was evaluated at nine months postoperatively. Longitudinal radiographic data was correlated to a histologic and morphometric evaluation of each bone graft. Computer tomography was used for the latter analysis. Results showed that untreated allografts, although surrounded by a periosteal bone cuff, were poorly incorporated. Partial demineralization lead to excessive resorption of allografts, but little new bone formation. Laser perforation and partial demineralization induced complete incorporation of allografts into the host bone. Based on the results of the radiographic, histologic and morphometric evaluation, the development of laser-perforated and partially demineralized bone allografts was proposed for clinical use.

  2. Management of postorthodontic demineralized white lesions with microabrasion: a quantitative assessment.

    Science.gov (United States)

    Murphy, Tania C; Willmot, Derrick R; Rodd, Helen D

    2007-01-01

    The aim of this study was to quantify changes in postorthodontic demineralized enamel lesion surface areas after microabrasion. The study group comprised 8 orthodontic patients (mean age,17.3 years) with multiple decalcified enamel lesions after fixed orthodontic therapy. Two demineralized areas were randomly selected for interventive treatment in each patient. Microabrasion was undertaken on these lesions by using a well-accepted 18% hydrochloric acid and pumice technique. Standardized intraoral images were taken of the lesions before and immediately after microabrasion. Image-processing software was used to quantify (mm2) the visible areas of the demineralized lesions before and after microabrasion. The total labial surface area of each tooth was also determined, and the area affected by demineralization was expressed as a percentage of total tooth surface. Images were reanalyzed a month later to determine the repeatability of the method. Microabrasion significantly reduced visible enamel demineralization (P Microabrasion is an effective treatment approach for the cosmetic improvement of long-standing postorthodontic demineralized enamel lesions.

  3. Supercritical Carbon Dioxide–Based Sterilization of Decellularized Heart Valves

    Directory of Open Access Journals (Sweden)

    Ryan S. Hennessy, MD

    2017-02-01

    Full Text Available Summary: Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid– and supercritical carbon dioxide–treated valves were found to be sterile using histology, microbe culture, and electron microscopy assays. The cusp tensile properties of supercritical carbon dioxide–treated valves were higher compared with valves treated with other techniques. Superior sterility and integrity was found in the decellularized valves treated with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Key Words: decellularized, decontamination, heart valve, tensile properties, tissue engineering

  4. [Evaluation of the influence of sterilization method on the stability of carboxymethyl cellulose wound dressing].

    Science.gov (United States)

    Muselík, Jan; Wojnarová, Lenka; Masteiková, Ruta; Sopuch, Tomáš

    2013-04-01

    Carboxymethyl cellulose, especially its sodium salt, is a versatile pharmaceutical excipient. From a therapeutic point of view, sodium salt of carboxymethyl cellulose is used in the production of modern wound dressings to allow moist wound healing. Wound dressings must be sterile and stable throughout their shelf life and have to be able to withstand different temperature conditions. At the present time, a number of sterilization methods are available. In the case of polymeric materials, the selected sterilization process must not induce any changes in the polymer structure, such as polymer chains cleavage, changes in cross-linking, etc. This paper evaluates the influence of different sterilization methods (γ-radiation, β-radiation, ethylene oxide) on the stability of carboxymethyl cellulose and the results of long-term and accelerated stability testing. Evaluation of samples was performed using size-exclusion chromatography. The obtained results showed that ethylene oxide sterilization was the least aggressive variant of the sterilization methods tested. When the γ-radiation sterilization was used, the changes in the size of the carboxymethyl cellulose molecule occurred. In the course of accelerated and long term stability studies, no further degradation changes were observed, and thus sterilized samples are suitable for long term storage.

  5. Optimization of moist heat sterilization.

    Science.gov (United States)

    Mannermaa, J P; Yliruusi, J

    1993-01-01

    The use of different combinations of sterilization time and temperature in a pilot scale autoclave, GEV 612 AR-2 (Getinge Ab, Sweden), in optimizing the sterilization process was studied. All three programs used had the same sterilization efficacy (F0 = 15 minutes) but different sterilization temperatures (116, 121, and 126 degrees C) and total process times (98, 57, and 44 minutes). The heat distribution during the sterilization phase was, in all cases, very uniform, the greatest difference being 0.5 degrees C. Also the F0 values differed only by +/- 0.5 minutes from each other. The F0 value increases linearly with all programs until the beginning of the cooling phase. The main effect of different sterilization temperatures on the cumulative F0 curves is an increase in the slope of the curves with increasing sterilization temperature. First order temperature change constants were determined both for the heating phase and the cooling phase. The numeric values of the rate constants for the heating and the cooling phases were 0.20 +/- 0.03 and 0.046 +/- 0.005 min-1, respectively. It is concluded that the pilot autoclave used in this study controls the sterilization process very accurately. The observed variations between F0 values at different positions in the autoclave chamber are acceptable. On the basis of this study an accurately engineered and controlled autoclave is required in process optimization. It also is possible to use higher sterilization temperatures than usually suggested in pharmacopeias and thus to shorten the process time.

  6. Osteoinductive and Osteopromotive Variability among Different Demineralized Bone Allografts.

    Science.gov (United States)

    Wei, Lingfei; Miron, Richard J; Shi, Bin; Zhang, Yufeng

    2015-06-01

    The purpose of this investigation was to compare the osteoinductive and osteopromotive potential of two widely used demineralized freeze-dried bone allografts (DFDBA) (Osteotech® DFDBA and LifeNet® DFDBA). Twenty-seven male Wistar rats (mean body weight 200 g) were treated with either DFDBA from Osteotech and LifeNet or control for femoral and intramuscular defects and assigned to histological analysis at 2, 4, and 8 weeks postimplantation. Hematoxylin and eosin (H&E), Safranin-O, tartrate-resistant acid phosphatase (TRAP), and osteopontin (OPN) staining were performed. Quantitative analysis of mineralized new bone to total volume (BV/TV) was assessed by micro-computed tomography. Both allografts demonstrated osteoinductive potential at 2 weeks as assessed by intramuscular bone formation. LifeNet DFDBA displayed continual new bone formation at 4 and 8 weeks, whereas Osteotech particles were fully resorbed by 4 weeks postimplantation. Femur defects demonstrated significantly greater BV/TV at 4 and 8 weeks with higher expression of OPN staining around LifeNet DFDBA particles. TRAP-positive cells were visible in and around both allograft materials. The results from the present study indicate that variability among allografts exists. In the present, LifeNet DFDBA supported more new bone formation. Further larger animal models or clinical trials are required to validate these findings. © 2013 Wiley Periodicals, Inc.

  7. Ar + NO microwave plasmas for Escherichia coli sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Hueso, Jose L; Rico, Victor J; Cotrino, Jose; Gonzalez-Elipe, Agustin R [Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla, Centro de Investigaciones Cientificas Isla de la Cartuja, Avda. Americo Vespucio 49, 41092 Sevilla (Spain); Frias, Jose E [Instituto de BioquImica Vegetal y FotosIntesis (IBVF-CSIC). Centro de Investigaciones CientIficas Isla de la Cartuja. Avda Americo Vespucio, 49, 41092 Sevilla (Spain)], E-mail: jhueso@icmse.csic.es

    2008-05-07

    Ar + NO microwave discharges are used for sterilization and the results are compared with additional experiments with Ar, O{sub 2} and N{sub 2}-O{sub 2} plasma mixtures. The NO{sup *} species produced in the Ar-NO mixtures remain up to long distances from the source, thus improving the sterilization efficiency of the process. E. coli individuals exposed to the Ar + NO plasma undergo morphological damage and cell lysis. Combined effects of etching (by O{sup *} and Ar{sup *} species) and UV radiation (from deactivation of NO{sup *} species) are responsible for the higher activity found for this plasma mixture. (fast track communication)

  8. Fluoride-dependent formation of mineralized layers in bovine dentin during demineralization in vitro.

    Science.gov (United States)

    Damen, J J; Buijs, M J; ten Cate, J M

    1998-01-01

    Demineralization of dentin in the presence of fluoride produces lesions with a mineralized surface layer which becomes thicker and more mineralized with higher fluoride concentrations whereas the lesion depth is hardly affected. The aim of this study was to investigate the effects of the time of fluoride treatment and the amount of fluoride taken up on the properties of the mineralized layer. Discs of bovine dentin embedded in methylmethacrylate with one surface exposed were demineralized in 50 mM acetic acid, 2.2 mM CaCl2, 2.2 mM KH2PO4, pH 5.0. At the start and/or later during the demineralization period, the specimens were incubated individually for 1 or 2 days in 10 ml of the same demineralization solution supplemented with 0.5, 2.0 or 5.0 ppm fluoride, which was then assessed for changes in calcium and fluoride concentrations. After 2, 5 and 8 days, specimens were sectioned for microradiographic analysis so as to follow development of the lesions and the mineralized layers. The results were the following: While demineralization with fluoride present at the first day led to the formation of a surface layer, fluoride present only at a later day produced a subsurface layer, not at the lesion front but closer to the surface. This layer resulted from (re)precipitation and not from preservation of the original mineral. The 'integrated mineral content' of the surface layer increased linearly with the uptake of fluoride, which resulted in an apparent fluorapatite content of about 20 vol%. The profiles of the surface layers remained unchanged during continued demineralization in the absence of fluoride. It was concluded that in the presence of fluoride mineral loss is reduced as a result of the reprecipitation of dissolved mineral ions as a layer of fluoride-enriched apatite. This layer does not offer protection of underlying dentin against continued demineralization.

  9. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng

    2012-09-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  10. Sterile pyuria: a forgotten entity

    OpenAIRE

    Goonewardene, Sanchia; Persad, Raj

    2015-01-01

    Sterile pyuria is a common entity. Yet there are no guidelines to address this issue. We have conducted a systematic review over 20 years and reviewed the results. Guidelines for assessment, diagnosis and management are developed based on these results.

  11. Sterile pyuria: a forgotten entity.

    Science.gov (United States)

    Goonewardene, Sanchia; Persad, Raj

    2015-10-01

    Sterile pyuria is a common entity. Yet there are no guidelines to address this issue. We have conducted a systematic review over 20 years and reviewed the results. Guidelines for assessment, diagnosis and management are developed based on these results.

  12. Portable Decontamination and Sterilization System

    National Research Council Canada - National Science Library

    Bell, William; Smerjac, Suzanne; Smith, Bryan

    2004-01-01

    TDA Research, Inc., (TDA) is developing a portable system to generate chlorine dioxide, which can be used for biodecontamination of small items and to sterilize medical and dental instruments in austere environments...

  13. Effect of sterilization process on surface characteristics and biocompatibility of pure Mg and MgCa alloys.

    Science.gov (United States)

    Liu, X L; Zhou, W R; Wu, Y H; Cheng, Y; Zheng, Y F

    2013-10-01

    The aim of this work was to investigate the effect of various sterilization methods on surface characteristics and biocompatibility of MgCa alloy, with pure Mg as a comparison, including steam autoclave sterilization (SA), ethylene oxide steam sterilization (EO), glutaraldehyde sterilization (GD), dry heat sterilization (DH) and Co60 γ ray radiation sterilization (R) technologies. The surface characterizations were performed by environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, water contact angle and surface free energy measurement, whereas the cytotoxicity and hemocompatibility were evaluated by cellular adhesive experiment, platelet adhesion and hemolysis test. The results showed that the five sterilization processes caused more changes on the surface of MgCa alloy than that on the surface of pure Mg. The GD sterilization caused the most obvious changes on the surface of the pure Mg, and the SA sterilization made the largest alteration on the MgCa alloy surface. The GD and DH sterilization processes could cause increases on surface free energy for both pure Mg and MgCa alloys, while the other three sterilization processes reduced the surface free energy. The DH and GD sterilization processes caused the least alteration on the cell adhesion on pure Mg surface, whereas the EO sterilization performed the greatest impact on the cell adhesion on the Mg-Ca alloy surface. The hemolysis percentage of pure Mg and MgCa alloys were reduced by SA sterilization, meanwhile the other four sterilization processes increased their hemolysis percentages significantly, especially for the EO sterilization. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. 9 CFR 113.54 - Sterile diluent.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Sterile diluent. 113.54 Section 113.54... Requirements § 113.54 Sterile diluent. Sterile Diluent shall be supplied in a final container by the licensee when such diluent is required for rehydration or dilution of the vaccine. (a) Sterile Diluent may be...

  15. New disinfection and sterilization methods.

    OpenAIRE

    Rutala, W A; Weber, D.J.

    2001-01-01

    New disinfection methods include a persistent antimicrobial coating that can be applied to inanimate and animate objects (Surfacine), a high-level disinfectant with reduced exposure time (ortho-phthalaldehyde), and an antimicrobial agent that can be applied to animate and inanimate objects (superoxidized water). New sterilization methods include a chemical sterilization process for endoscopes that integrates cleaning (Endoclens), a rapid (4-hour) readout biological indicator for ethylene oxid...

  16. Effects of sterilization on Poly(Vinyl Alcohol) (PVAl) hydrogels matrices

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Maria Jose A.; Rodrigues, Kiriaki M.S.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: mariajhho@yahoo.com.br

    2007-07-01

    The poly(vinyl alcohol) (PVAl) is a polymer of great interest for new materials development due to its specific characteristics particularly for biomedical applications. PVAl with polyethylene glycol (PEG) 300 was processed using freezing-thawing sequence of thermal cycles for hydrogel preparation. The samples were evaluated by gel fraction (%), water uptake (%) and thermogravimetry analysis (TGA). The hydrogel was sterilized under ionizing radiation from Cobalt-60 source at 25 kGy dose and the effects of the radiation on the hydrogel properties was discussed in this work. The results of swelling, gel fraction and thermal stability are in part influenced by the sterilization method. The presence of PEG in PVAl hydrogels forms less dense hydrogels under freeze/thawing cycles. The swelling in the sterilized hydrogels is higher than the not sterilized hydrogel in consequence of chain scissions in the polymeric structure due to the radiation process. (author)

  17. Selection of sterilization methods for planetary return missions

    Science.gov (United States)

    Trofimov, V. I.; Victorov, A.; Ivanov, M.

    1996-01-01

    Two tasks must be accomplished to provide planetary protection for Mars return missions: (1) sterilization of the scientific module to be landed on Mars and (2) reliable sterilization of all material returned to Earth, while ensuring the scientific integrity of martian samples. This paper examines similarity and differences between these two tasks, and includes a discussion of technological implementation conditions and the nature of terrestrial and hypothesized martian microflora. The feasibility of a number of chemical and physical (ultraviolet and ionizing radiation and heating) methods of sterilization for use on the ground and onboard are discussed and compared. A combination of different methods will probably be selected as the most appropriate for ensuring planetary protection on the return mission.

  18. A quantitative analysis of mineral loss and shrinkage of in vitro demineralized human root surfaces.

    Science.gov (United States)

    Ten Cate, J M; Nyvad, B; Van de Plassche-Simons, Y M; Fejerskov, O

    1991-10-01

    Demineralization of dentin specimens proceeds at a faster rate than that of enamel. Although this is generally accepted, a quantification of the rate of formation of root lesions is hampered by the shrinkage of the lesions when these are dried prior to microradiographic analysis. This leads to a significant underestimation of the lesion depth and total mineral loss. The aim of this paper was to quantitate the rate of mineral loss during root lesion formation in vitro and to determine the shrinkage of root specimens as a result of drying. Unerupted roots of human teeth were subjected to a demineralizing system of 0.1 mol/L lactate buffer (pH = 4.8) with 0.2 mmol/L methanehydroxydiphosphonate during four, 11, 22, and 44 days. The root lesions were assessed by quantitative microradiography. The demineralizing solutions were analyzed to determine the amounts of root tissue dissolved. A comparison of these two sets of data showed that, with the demineralizing system used, root lesions may shrink up to 62%. Fixation of the specimens in fixative did not affect this shrinkage. Chemical analysis showed that mineral loss proceeded linearly with time. From the data-sets of this study, a model was developed to compensate for the shrinkage in the dentin specimens. In this way, it was possible to calculate the lesion depth at four demineralization times as being 130, 220, 320, and 530 microns, respectively. These values were in agreement with a microscopic determination of the lesion depth.

  19. Demineralized dentin 3D porosity and pore size distribution using mercury porosimetry.

    Science.gov (United States)

    Vennat, Elsa; Bogicevic, Christine; Fleureau, Jean-Marie; Degrange, Michel

    2009-06-01

    The objectives of this study were to assess demineralized dentin porosity and quantify the different porous features distribution within the material using mercury intrusion porosimetry (MIP) technique. We compared hexamethyldisilazane (HMDS) drying and lyophilization (LYO) (freeze-drying) in sample preparation. Fifty-six dentin discs were assigned into three groups. The control (CTR) group discs were superficially acid-etched (15s 37% H(3)PO(4)) to remove the smear layer and then freeze-dried whereas LYO and HMDS groups samples were first totally demineralized using EDTA 0.5M and then freeze-dried and HMDS-dried respectively. MIP was used to determine open porosity and pore size distribution of each pair of samples. Field emission scanning electron microscopy (FESEM) was used to illustrate the results. The results showed two types of pores corresponding either to tubules and micro-branches or to inter-fibrillar spaces created by demineralization. Global porosity varied from 59% (HMDS-dried samples) to 70% (freeze-dried samples). Lyophilization drying technique seems to lead to less shrinkage than HMDS drying. FESEM revealed that collagen fibers of demineralized lyophilized samples are less melted together than in the HMDS-dried samples. Demineralized dentin porosity is a key parameter in dentin bonding that will influence the hybrid layer quality. Its characterization could be helpful to improve the monomers infiltration.

  20. Demineralized Dentin as a Semi-Rigid Barrier for Guiding Periodontal Tissue Regeneration.

    Science.gov (United States)

    Qin, Xu; Zou, Fang; Chen, Weimin; Xu, Yiwen; Ma, Bo; Huang, Zhibin; Zhu, Guangxun; Zhou, Bin

    2015-12-01

    Guided tissue regeneration (GTR) is an accepted approach in the correction of periodontal bone loss. Nonetheless, the deficiencies of commonly applied absorbable membrane, such as flexibility and limited osteoconductive and osteoinductive capability, still leave much room for improvement. Thus, the feasibility of applying demineralized dentin tissue to improve the therapeutic effect of GTR in periodontal regeneration was explored. Demineralized dentin was harvested after acid treatment, and its physiochemical properties were assessed in terms of mineralization density, contact angle, three-point test, and cell attachment. Because of its similar characteristics with bone tissue, dentin that had been acid-treated for 6 hours was chosen to repair a periodontal defect using an induced-periodontitis canine model. Histologic measurements were taken to compare its therapeutic effects to an absorbable membrane group and an untreated group. The demineralized dentin displayed continually decreased hardness and density as the acid etching time was prolonged. Enhanced attachment and spreading of bone marrow mesenchymal stem cells were observed on the 6-hour processed dentin. Furthermore, in the demineralized dentin group, more periodontal tissues were newly formed compared with the biomembrane and untreated groups. Acid etching represents an easy and promising approach to obtain demineralized dentin with desirable properties, similar to bone, for clinical application to promote periodontal tissue regeneration.

  1. Comparison of the Effect of Three Cements on Prevention of Enamel Demineralization Adjacent to Orthodontic Bands

    Directory of Open Access Journals (Sweden)

    Mehdi Kashani

    2012-06-01

    Full Text Available Background and aims. This in vitro study was designed to compare enamel demineralization depths adjacent to bands cemented with zinc polycarboxylate, glass ionomer (GI and resin-modified glass ionomer (RMGI, in order to achieve minimal enamel demineralization during orthodontic treatment. Materials and methods. Sixty fully developed extracted third molars were randomly divided into three test groups each containing 20 samples, used to cement orthodontic bands with zinc polycarboxylate, GI and RMGI. All samples were demineralized using White method using hydroxyapatite, latic acid and Carbapol for in vitro caries simulation, and then, immersed in 10% solution of methylene blue. The mean depth of dye penetration was assessed up to 0.1 millimeter, reflecting the depth of enamel demineralization. One way ANOVA and LSD statistical tests were employed to evaluate significant differences among groups. Results. The highest dye penetration depth was seen in zinc polycarboxylate group, followed by GI, and RMGI groups, respectively, with significant differences among each two groups (P < 0.05. Conclusion. The use of RMGI cement seems to present significantly better prevention of enamel demineralization adjacent to orthodontics bands.

  2. Prevention of enamel demineralization during orthodontic treatment: an in vitro comparative study.

    Science.gov (United States)

    Bichu, Yashodhan M; Kamat, Nandini; Chandra, Pavan Kumar; Kapoor, Aditi; Razmus, Thomas; Aravind, N K S

    2013-01-01

    Enamel demineralization is considered to be the most prevalent and significant iatrogenic effect associated with fixed orthodontic treatment and can seriously jeopardize both tooth longevity and dental esthetics. This in vitro study was undertaken to compare the effectiveness of four different commercially available surface treatment medicaments for the inhibition of enamel demineralization. Seventy-five intact maxillary premolars extracted from patients undergoing orthodontic treatment were divided into five equal groups and were subjected to one of the following protocols: no treatment (control group) or treatment with one of the following four medicaments: fluoride varnish (Fluor Protector [FP]), casein phosphopeptide-amorphous calcium phosphate (GC Tooth Mousse [TM]), calcium sodium phosphosilicate (SHY-NM), and casein phosphopeptide-amorphous calcium phosphate with fluoride (GC Tooth Mousse Plus [TMP]). All the teeth were subjected to ten Cate demineralization solution?for 96 hours and subsequently evaluated under polarized light microscopy to obtain the mean depths of enamel demineralization. One-way analysis of variance and Bonferroni comparison tests were used to obtain statistically significant differences between the five different groups at P < .05. All four surface treatment medicaments provided statistically significant reduction in the depths of enamel demineralization as compared with the control group. FP provided the greatest protection of enamel surface in terms of reduction of lesion depth, followed by TMP, SHY-NM, and TM. The use of these commercially available medicaments could prove to be beneficial for patients undergoing orthodontic treatment and who are at a risk for developing enamel decalcification.

  3. Sterilization Mechanism of Nitrogen Gas Plasma Exposure

    OpenAIRE

    Hideharu Shintani

    2015-01-01

    As already published by Shintani et al, gas plasma sterilization is the alternative sterilization procedures to the existing sterilization procedures due to applicable to the several sensitive healthcare products and attainable both sterility assurance level (SAL) of 10-6 and material/functional compatibility, which authorities and GMP (good manufacturing practice) are required. In addition there was progress in the field of plasma-based sterilization, there are still some questions. The aim ...

  4. Male and female sterility in Zambia

    OpenAIRE

    Athena Pantazis; Samuel J Clark

    2014-01-01

    Background: Population measures of sterility are traditionally constructed for women, despite fertility and sterility being conditions of the couple. Estimates of male sterility provide insight into population-level sterility, and complement estimates based solely on women. Objective: This study seeks to estimate male sterility for the Gwembe Tonga of Zambia using male birth histories collected by the Gwembe Tonga Research Project from 1957 to 1995, while providing context by estimating fe...

  5. Demineralized bone matrix used for direct pulp capping in rats.

    Directory of Open Access Journals (Sweden)

    Qian Liu

    Full Text Available To evaluate the wound healing process following direct pulp capping with demineralized bone matrix (DBM and calcium hydroxide (Ca(OH2.Fifty 8-weeks-old SPF Wistar male rats were divided into two groups: one was the DBM treated group, and the other was the Ca(OH2 treated group. Pulpotomy was performed on the maxillary first molar of one side of each rat, and the another side was left as the blank control. Rats were sacrificed after each observation period (1, 3, 7, 14 and 28 days and specimen slices were made. Hematoxylin-Eosin (HE staining was used for observing the changes of pulp tissue, and immunohistochemical staining was used for observing the expression of reparative dentinogenesis-related factors runt transcription factor 2 (Runx2, type I collagen (COL I, osteocalcin (OCN and dentin sialoprotein (DSP.Inflammatory cell infiltration (ICI and pulp tissue disorganization (PTD could be observed in both the DBM and Ca(OH2 groups at all observation periods. The DBM group showed slighter ICI on 1 and 28 days and milder PTD on 28 days, with a significant difference (P<0.05. Reparative dentin formation (RDF could initially be observed on 14 days postoperatively, and the DBM group showed more regular and thinner RDF with significant differences on 14 and 28 days compared with the Ca(OH2 group (P<0.05. In both groups, the expression of Runx2, COL I, DSP and OCN were positive. Generally, the expression of these four factors in the DBM group was stronger than the Ca(OH2 group on the same observation periods.DBM had the ability of inducing odontoblast differentiation and promoting dentinogenesis. DBM could initiate physiologic wound healing in pulp and had the ability to promote reparative dentin formation. Consequently, DBM may be an acceptable alternative for direct pulp capping.

  6. Histopathological evaluation of bone regeneration using human resorbable demineralized membrane

    Directory of Open Access Journals (Sweden)

    Tatić Zoran

    2010-01-01

    Full Text Available Background/Aim. Filling a bone defect with bone substitution materials is a therapy of choice, but the infiltration of connective tissue from the mucoperiostal flap may compromise a healing of bone substitutions with bony wall defects. Application of membrane as a barrier is indicated as a solution to this problem. The aim of this study was to show a pathohistological view of bone regeneration and the significance of human resorbable demineralized membrane (HRDM, 200 μ thick in bone regeneration regarding mandibular defects in an experiment on dogs. Methods. The experiment was performed on six dogs. Bone defects were created in all six dogs on the right side of the mandible after the elevation of the mucoperiostal flap. One defect was filled with human deproteinised bone (HDB, and in between HDB and soft tissue RHDM of 200 μ thick was placed. In the second defect, used as a control one, only HDB without RHDM was placed. Two dogs were sacrificed two months after the surgery, another two dogs four months after the surgery and the last two dogs six months after the surgery. After that, samples of bone tissue were taken for histopathological analysis. Results. In all the six dogs with defects treated with HDB and RHDM the level of bone regeneration was much higher in comparison with the control defects without RHDM. Conclusion. Membrane, as a cover of bony defect, is useful and benefits bone regeneration. Bony defects covered with RHDM show better bony healing despite the fact that bone regeneration was not fully complete for as long as six months after the RHDM implantation.

  7. Genomic networks of hybrid sterility.

    Directory of Open Access Journals (Sweden)

    Leslie M Turner

    2014-02-01

    Full Text Available Hybrid dysfunction, a common feature of reproductive barriers between species, is often caused by negative epistasis between loci ("Dobzhansky-Muller incompatibilities". The nature and complexity of hybrid incompatibilities remain poorly understood because identifying interacting loci that affect complex phenotypes is difficult. With subspecies in the early stages of speciation, an array of genetic tools, and detailed knowledge of reproductive biology, house mice (Mus musculus provide a model system for dissecting hybrid incompatibilities. Male hybrids between M. musculus subspecies often show reduced fertility. Previous studies identified loci and several X chromosome-autosome interactions that contribute to sterility. To characterize the genetic basis of hybrid sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL. Many trans eQTL cluster into eleven 'hotspots,' seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL-but not cis eQTL-were substantially lower when mapping was restricted to a 'fertile' subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. The integrated mapping approach we employed is

  8. Genomic networks of hybrid sterility.

    Science.gov (United States)

    Turner, Leslie M; White, Michael A; Tautz, Diethard; Payseur, Bret A

    2014-02-01

    Hybrid dysfunction, a common feature of reproductive barriers between species, is often caused by negative epistasis between loci ("Dobzhansky-Muller incompatibilities"). The nature and complexity of hybrid incompatibilities remain poorly understood because identifying interacting loci that affect complex phenotypes is difficult. With subspecies in the early stages of speciation, an array of genetic tools, and detailed knowledge of reproductive biology, house mice (Mus musculus) provide a model system for dissecting hybrid incompatibilities. Male hybrids between M. musculus subspecies often show reduced fertility. Previous studies identified loci and several X chromosome-autosome interactions that contribute to sterility. To characterize the genetic basis of hybrid sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven 'hotspots,' seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL-but not cis eQTL-were substantially lower when mapping was restricted to a 'fertile' subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. The integrated mapping approach we employed is applicable in a broad

  9. Genomic Networks of Hybrid Sterility

    Science.gov (United States)

    Turner, Leslie M.; White, Michael A.; Tautz, Diethard; Payseur, Bret A.

    2014-01-01

    Hybrid dysfunction, a common feature of reproductive barriers between species, is often caused by negative epistasis between loci (“Dobzhansky-Muller incompatibilities”). The nature and complexity of hybrid incompatibilities remain poorly understood because identifying interacting loci that affect complex phenotypes is difficult. With subspecies in the early stages of speciation, an array of genetic tools, and detailed knowledge of reproductive biology, house mice (Mus musculus) provide a model system for dissecting hybrid incompatibilities. Male hybrids between M. musculus subspecies often show reduced fertility. Previous studies identified loci and several X chromosome-autosome interactions that contribute to sterility. To characterize the genetic basis of hybrid sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL—but not cis eQTL—were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. The integrated mapping approach we employed is

  10. Radiation biology of mosquitoes

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2009-11-01

    Full Text Available Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi- field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  11. Radiation biology of mosquitoes.

    Science.gov (United States)

    Helinski, Michelle E H; Parker, Andrew G; Knols, Bart G J

    2009-11-16

    There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  12. Radiation biology of mosquitoes

    Science.gov (United States)

    Helinski, Michelle EH; Parker, Andrew G; Knols, Bart GJ

    2009-01-01

    There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators. PMID:19917076

  13. Vibrational monitor of early demineralization in tooth enamel after in vitro exposure to phosphoridic liquid

    Science.gov (United States)

    Pezzotti, Giuseppe; Adachi, Tetsuya; Gasparutti, Isabella; Vincini, Giulio; Zhu, Wenliang; Boffelli, Marco; Rondinella, Alfredo; Marin, Elia; Ichioka, Hiroaki; Yamamoto, Toshiro; Marunaka, Yoshinori; Kanamura, Narisato

    2017-02-01

    The Raman spectroscopic method has been applied to quantitatively assess the in vitro degree of demineralization in healthy human teeth. Based on previous evaluations of Raman selection rules (empowered by an orientation distribution function (ODF) statistical algorithm) and on a newly proposed analysis of phonon density of states (PDOS) for selected vibrational modes of the hexagonal structure of hydroxyapatite, a molecular-scale evaluation of the demineralization process upon in vitro exposure to a highly acidic beverage (i.e., CocaCola™ Classic, pH = 2.5) could be obtained. The Raman method proved quite sensitive and spectroscopic features could be directly related to an increase in off-stoichiometry of the enamel surface structure since the very early stage of the demineralization process (i.e., when yet invisible to other conventional analytical techniques). The proposed Raman spectroscopic algorithm might possess some generality for caries risk assessment, allowing a prompt non-contact diagnostic practice in dentistry.

  14. Kinetic modelling of the demineralization of shrimp exoskeleton using citric acid

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    Alewo Opuada AMEH

    2014-11-01

    Full Text Available Citric acid was used in the demineralization of shrimp exoskeleton and the kinetics of the demineralization process was studied. Kinetic data was obtained by demineralisation using five acid concentrations (0.1, 0.2, 0.3, 0.4 and 0.5M. The obtained kinetic data were fitted to the shrinking core model for fluid particle reactions. The concentration of calcium was found to decrease with time. For all acid concentrations considered, the best predictive mechanism for the demineralization process was determined to be Ash Layer Diffusion Control Mechanism. This was indicated by the high R2 values obtained (0.965 with 150% excess of citric acid.

  15. The limits of sterility assurance.

    Science.gov (United States)

    von Woedtke, Thomas; Kramer, Axel

    2008-09-03

    Sterility means the absence of all viable microorganisms including viruses. At present, a sterility assurance level (SAL) of 10(-6) is generally accepted for pharmacopoeial sterilization procedures, i.e., a probability of not more than one viable microorganism in an amount of one million sterilised items of the final product. By extrapolating the reduction rates following extreme artificial initial contamination, a theoretical overall performance of the procedure of at least 12 lg increments (overkill conditions) is demanded to verify an SAL of 10(-6). By comparison, other recommendations for thermal sterilization procedures demand only evidence that the difference between the initial contamination and the number of test organisms at the end of the process amount to more than six orders of magnitude. However, a practical proof of the required level of sterility assurance of 10(-6) is not possible. Moreover, the attainability of this condition is fundamentally dubious, at least in non-thermal procedures. Thus, the question is discussed whether the undifferentiated adherence to the concept of sterility assurance on the basis of a single SAL of 10(-6) corresponds with the safety requirements in terms of patient or user safety, costs and energy efficiency. Therefore, in terms of practical considerations, a concept of tiered SALs is recommended, analogous to the comparable and well-established categorization into "High-level disinfection", "Intermediate-level disinfection" and "Low-level disinfection". The determination of such tiered SALs is geared both to the intended application of the sterilized goods, as well as to the characteristics of the products and the corresponding treatment options.In the case of aseptic preparation, filling and production procedures, a mean contamination probability of 10(-3) is assumed. In automated processes, lower contamination rates can be realized. In the case of the production of re-usable medical devices, a reduction of at least 2

  16. Changes in composition and enamel demineralization inhibition activities of gallic acid at different pH values

    NARCIS (Netherlands)

    Zhang, J.; Huang, X.; Huang, S.; Deng, M.; Xie, X.; Liu, M.; Liu, H.; Zhou, X.; Li, J.; ten Cate, J.M.

    2015-01-01

    Background. Gallic acid (GA) has been shown to inhibit demineralization and enhance remineralization of enamel; however, GA solution is highly acidic. This study was to investigate the stability of GA solutions at various pH and to examine the resultant effects on enamel demineralization. Methods.

  17. Demineralization of wood using wood-derived acid: Towards a selective pyrolysis process for fuel and chemicals production

    NARCIS (Netherlands)

    Oudenhoven, Stijn; Westerhof, Roel Johannes Maria; Aldenkamp, N.; Brilman, Derk Willem Frederik; Kersten, Sascha R.A.

    2013-01-01

    A process concept for the pyrolysis of demineralized wood to obtain high organic and especially levoglucosan yields is proposed and tested experimentally. The wood is demineralized using organic acids, produced and concentrated within the same pyrolysis process. Pine wood was pyrolyzed in a

  18. Demineralization of Sargassum spp. macroalgae biomass: selective hydrothermal liquefaction process for bio-oil production

    Directory of Open Access Journals (Sweden)

    Liz M Díaz-Vázquez

    2015-02-01

    Full Text Available Algae biomasses are considered a viable option for the production of biofuel because of their high yields of oil produced per dry weight. Brown macroalgae Sargassum spp. are one of the most abundant species of algae in the shores of Puerto Rico. Its availability in large quantity presents a great opportunity for use as a source of renewable energy. However, high ash content of macroalgae affects the conversion processes and the quality of resulting fuel products. This research studied the effect of different demineralization treatments of Sargassum spp. biomass, subsequent hydrothermal liquefaction (HTL and bio-oil characterization. Demineralization constituted five different treatments: nanopure water, nitric acid, citric acid, sulfuric acid, and acetic acid. Performance of demineralization was evaluated by analyzing both demineralized biomass and HTL products by the following analyses: total carbohydrates, proteins, lipids, ash content, caloric content, metals analysis, Fourier Transform Infrared - Attenuated Total Reflectance (FTIR-ATR Spectroscopy, Energy Dispersive Spectroscopy (EDS, Scanning Electron Microscopy (SEM, and GCMS analysis. HTL of Sargassum spp. before and after citric acid treatment, was performed in a 1.8 L batch reactor system at 350°C with a holding time of 60 min and high pressures (5-21 MPa. Demineralization treatment with nitric acid was found the most effective in reducing the ash content of the macroalgae biomass from 27.46% to 0.99% followed by citric acid treatment that could reduce the ash content to 7%. Citric acid did not show significant leaching of organic components such as carbohydrates and proteins, and represented a less toxic and hazardous option for demineralization. HTL of untreated and citric acid treated Sargassum spp. resulted in bio-oil yields of 18.4±0.1 % and 22.2±0.1 % (ash free dry basis, respectively.

  19. Effects of Different Demineralization-Inhibiting Methods on the Shear Bond Strength of Glass-Ceramics.

    Science.gov (United States)

    Dilber, Erhan; Akın, Mehmet; Yavuz, Tevfik; Erdem, Ali

    2015-07-01

    This in vitro study was undertaken to evaluate the effects of different demineralization-inhibiting methods on the shear bond strength (SBS) of glass-ceramics. Ninety extracted intact human mandibular lateral insicors were randomly divided into six equal groups. Group C was left untreated, while enamel subsurface demineralization was induced in the other groups. In group D, porcelain discs (3 mm in diameter) were cemented to demineralized enamel by using total-etch photopolymerizing luting composite resin without pretreatment. Demineralized specimens in groups F, CA, M, and I were pretreated with fluoride gel, CPP-ACP paste, microabrasion, and resin infiltration, respectively, and then porcelain discs were cemented. SBS (MPa) was calculated from the failure load (N) per bonded area (mm(2)). Fracture types were examined by optical microscopy (40× magnification). Data were analyzed with ANOVA, Tukey's test, and G-test. ANOVA revealed significant intergroup differences (p < 0.01). No significant differences in SBS (MPa) were found between groups C (19.48 ± 2.0) and I (20.02 ± 1.6). Lower SBS values were recorded in groups D (7.93 ± 0.8), F (12.51 ± 1.5), CA (17.08 ± 1.3), and M (14.84 ± 1.4). Mixed and cohesive failures were the most prevalent in groups M and I, respectively. Resin infiltration enhanced the SBS of porcelain discs bonded to demineralized enamel when compared with the other demineralization-inhibiting methods. Resin infiltration could be useful to enhance adhesion of glass-ceramics to teeth with white spot lesions. © 2014 by the American College of Prosthodontists.

  20. The challenges of heat sterilization of peritoneal dialysis solutions: is there an alternative?

    Science.gov (United States)

    Hanrahan, Conor T; Himmele, Rainer; Diaz-Buxo, Jose A

    2012-01-01

    Peritoneal dialysis (PD) solutions are currently sterilized in an autoclave using high-temperature saturated steam. Although thermal methods are an effective means of sterilization, the heating of PD solutions results in the formation of toxic glucose degradation products (GDPs). Here, we review basic concepts in the sterilization of PD solutions and discuss possible alternatives to steam sterilization, including filtration, ohmic heat, ionizing radiation, and pulsed ultraviolet light. Although the latter methods have several advantages, many also have prohibitive limitations or have not been adequately studied for use on PD solutions. Thus, in the absence of suitable alternatives, conventional heat sterilization, in combination with low-GDP manufacturing practices, remains the best option at the present time.

  1. [Compatibilities and incompatibilities between gamma rays and ethylene oxide as consecutive sterilization methods].

    Science.gov (United States)

    de Souza, Rafael Queiroz; Graziano, Kazuko Uchikawa

    2010-12-01

    The doubt regarding the re-sterilization of articles made of polyvinyl chloride (PVC) sterilized with gamma radiation (GR) and subsequently with ethylene oxide (EO) persists to date. Through a systematic literature review, this article analyzed studies that demonstrated compatibilities and incompatibilities between the sterilization processes with GR and EO, when used as consecutive sterilization methods. Seven studies were analyzed. It was verified that there is a multifactor influence regarding the safety of the procedure and that the chromatography analytical method employed by most studies yielded controversial results. This fact indicates the need for further studies on the issue, using more sensitive analytical methods than gas chromatography, such as the biological reactivity test in cell cultures, in an attempt to clarify the chronic doubt regarding the adequacy or inadequacy of sterilizing previously gamma-irradiated materials with EtO.

  2. Zymography of Hybrid Layers Created Using Extrafibrillar Demineralization.

    Science.gov (United States)

    Gu, L; Mazzoni, A; Gou, Y; Pucci, C; Breschi, L; Pashley, D H; Niu, L; Tay, F R

    2017-12-01

    A chelate-and-rinse extrafibrillar calcium chelation dentin bonding concept has recently been developed and investigated for its effectiveness in improving resin-dentin bonding by bridging the gap between wet and dry dentin bonding. The objective of the present study was to evaluate the gelatinolytic activity of hybrid layers (HLs) created using the chelate-and-rinse bonding technique. Gelatinolytic activity within the HL was examined using in situ zymography and confocal laser-scanning microscopy after 24-h storage or after thermomechanical cycling. Dentin specimens were bonded with Prime&Bond NT (Dentsply Sirona) after conditioning with 15 wt% phosphoric acid for 15 s (control) or 15 wt% polymeric chelators (sodium salt of polyacrylic acid; PAAN) of 2 different molecular weights for 60 s. For each reagent, bonding was performed using dry-bonding and wet-bonding techniques ( n = 10). Slices containing the adhesive-dentin interface were covered with fluorescein-conjugated gelatin and examined with a confocal laser-scanning microscope. Fluorescence intensity emitted by the hydrolyzed fluorescein-conjugated gelatin was quantified. Gelatinolytic activity was expressed as the percentage of green fluorescence emitted within the HL. After storage for 24 h, enzymatic activity was only detected within the completely demineralized phosphoric acid-etched dentin, with values derived from dry bonding higher than those from wet bonding ( P < 0.05). Almost no fluorescence signals were detected within the HL when dentin was conditioned with PAANs compared with the controls ( P < 0.05). After thermomechanical cycling, enzymatic activities significantly increased for the phosphoric acid-conditioned, drying-bonding group compared with 24-h storage ( P < 0.05). The present study showed that the use of the chelate-and-rinse bonding concept for both dry-bonding and wet-bonding approaches results in the near absence of matrix-bound collagenolytic activities in the HL even after aging

  3. Microbicidal effectiveness of X-rays used for sterilization purposes

    DEFF Research Database (Denmark)

    Tallentire, Alan; Miller, Arne

    2015-01-01

    The radiation response of spores of Bacillus pumilus was examined for irradiation with 5–7 MeV X-ray at commercial sterilization facilities. The response was found to be the same as that for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV.......The radiation response of spores of Bacillus pumilus was examined for irradiation with 5–7 MeV X-ray at commercial sterilization facilities. The response was found to be the same as that for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV....

  4. Sterility of the uterine cavity

    DEFF Research Database (Denmark)

    Møller, Birger R.; Kristiansen, Frank V.; Thorsen, Poul

    1995-01-01

    In a prospective open study the sterility of the uterine cavity was evaluated in 99 women admitted for hysterectomy. The indications for hysterectomy were in most cases persistent irregular vaginal bleeding and fibromyomas of the uterus. Samples for both aerobic and anaerobic bacteria, Chlamydia...... trachomatis, yeasts and viruses were taken preoperatively from the apex of the vagina and cervical os. Immediately after hysterectomy the uterus was opened under sterile conditions and samples obtained from the isthmus and fundus of the uterine cavity for microbiological examination. Wet smears were taken...

  5. Strategy for Searching for a Dark Matter Sterile Neutrino

    CERN Document Server

    Boyarsky, A; Ruchayskiy, O; Shaposhnikov, M E; Tkachev, I I

    2006-01-01

    We propose a strategy of how to look for dark matter (DM) particles possessing a radiative decay channel and derive constraints on their parameters from observations of X-rays from our own Galaxy and its dwarf satellites. When applied to the sterile neutrinos in keV mass range, it allows a significant improvement of restrictions to its parameters, as compared with previous works.

  6. Male and female sterility in Zambia

    Directory of Open Access Journals (Sweden)

    Athena Pantazis

    2014-02-01

    Full Text Available Background: Population measures of sterility are traditionally constructed for women, despite fertility and sterility being conditions of the couple. Estimates of male sterility provide insight into population-level sterility, and complement estimates based solely on women. Objective: This study seeks to estimate male sterility for the Gwembe Tonga of Zambia using male birth histories collected by the Gwembe Tonga Research Project from 1957 to 1995, while providing context by estimating female sterility for the Gwembe Tonga, as well as female sterility in all of Zambia, from Zambian DHS data (1992, 1997, 2001-02, and 2007. Methods: Sterility is measured using the Larson-Menken subsequently infertile indicator. Estimates are produced using discrete time event history analysis. Results: The odds of sterility were higher for women than men, though women's odds of sterility were only 1.5 times that of men's in the middle reproductive years. The odds of sterility increased steadily with age for both men and women, and across all datasets. However, women's sterility increased much more sharply with age than men's did, and women's odds of sterility were higher than men's at all reproductive ages.

  7. Sterile diets for the immuno-compromised: Is there a need?

    Science.gov (United States)

    Butterweck, Joseph S.

    1995-02-01

    There is a general misunderstanding in the radiation processing industry about the use of sterile diets in the medical profession. Sterile diets are used on a limited basis in hospitals that specialize in cancer treatment and organ transplants. These patients are severely immuno-compromised. There are many other patients that are immuno-compromised that do not require sterile diets. These patients may require a diet that is pathogen-free and are aslo "low-microbial diets". Nosocomial infections have become a major issue in US hospitals. The "infection control committee" is the focus group responsible to assure nosocomial infections incidence are below the hospital goals. Application of ionizing radiation to sterilize diets has not been chosen because the product is not available at a reasonable total cost. This paper will discuss the hospitals views.

  8. Influence of different sterilization processes on the properties of commercial poly(lactic acid).

    Science.gov (United States)

    Savaris, M; Santos, V Dos; Brandalise, R N

    2016-12-01

    This study aims at analyzing the modifications in the morphological, physical, chemical and thermal properties of commercial poly(lactic acid) (PLA) films after exposure to five different sterilization processes. Films were obtained by compression molding, hygienized and sterilized by ethylene oxide (SEtO), hydrogen peroxide plasma (SH2O2), saturated steam (SSS), electron beam radiation (SEB) and gamma radiation (SGR). The samples of PLASEtO, PLASH2O2, PLASEB and PLASGR exhibited thermal and physical changes after being submitted to sterilization processes. PLASSS showed morphological, chemical, thermal and physical changes. It is concluded that processes by SEtO, SH2O2, SEB and EGR can be applied for the sterilization of PLA films and the SSS process is not recommended in view of the data obtained and test conditions reported in this study for PLA films. Copyright © 2016. Published by Elsevier B.V.

  9. Effects of sterilization treatments on the analysis of TOC in water samples.

    Science.gov (United States)

    Shi, Yiming; Xu, Lingfeng; Gong, Dongqin; Lu, Jun

    2010-01-01

    Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants. However, the effects of biological pretreatment (sterilization) on organic matter often have a negative impact on such experiments. Based on the principle of water total organic carbon (TOC) analysis, the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated. The results revealed that two conventional physical sterilization treatments, autoclaving and 60Co gamma-radiation sterilization, led to the direct decomposition of some organic pollutants, resulting in remarkable errors in the analysis of TOC in water samples. Furthermore, the extent of the errors varied with the intensity and the duration of sterilization treatments. Accordingly, a novel sterilization method for water samples, 0.45 microm micro-filtration coupled with ultraviolet radiation (MCUR), was developed in the present study. The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters. Before and after sterilization treatments, the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.

  10. Sterilization of Exopolysaccharides Produced by Deep-Sea Bacteria: Impact on Their Stability and Degradation

    Directory of Open Access Journals (Sweden)

    Sylvia Colliec-Jouault

    2011-02-01

    Full Text Available Polysaccharides are highly heat-sensitive macromolecules, so high temperature treatments are greatly destructive and cause considerable damage, such as a great decrease in both viscosity and molecular weight of the polymer. The technical feasibility of the production of exopolysaccharides by deep-sea bacteria Vibrio diabolicus and Alteromonas infernus was previously demonstrated using a bioproduct manufacturing process. The objective of this study was to determine which sterilization method, other than heat sterilization, was the most appropriate for these marine exopolysaccharides and was in accordance with bioprocess engineering requirements. Chemical sterilization using low-temperature ethylene oxide and a mixture of ionized gases (plasmas was compared to the sterilization methods using gamma and beta radiations. The changes to both the physical and chemical properties of the sterilized exopolysaccharides were analyzed. The use of ethylene oxide can be recommended for the sterilization of polysaccharides as a weak effect on both rheological and structural properties was observed. This low-temperature gas sterilizing process is very efficient, giving a good Sterility Assurance Level (SAL, and is also well suited to large-scale compound manufacturing in the pharmaceutical industry.

  11. Sterilization of exopolysaccharides produced by deep-sea bacteria: impact on their stability and degradation.

    Science.gov (United States)

    Rederstorff, Emilie; Fatimi, Ahmed; Sinquin, Corinne; Ratiskol, Jacqueline; Merceron, Christophe; Vinatier, Claire; Weiss, Pierre; Colliec-Jouault, Sylvia

    2011-02-10

    Polysaccharides are highly heat-sensitive macromolecules, so high temperature treatments are greatly destructive and cause considerable damage, such as a great decrease in both viscosity and molecular weight of the polymer. The technical feasibility of the production of exopolysaccharides by deep-sea bacteria Vibrio diabolicus and Alteromonas infernus was previously demonstrated using a bioproduct manufacturing process. The objective of this study was to determine which sterilization method, other than heat sterilization, was the most appropriate for these marine exopolysaccharides and was in accordance with bioprocess engineering requirements. Chemical sterilization using low-temperature ethylene oxide and a mixture of ionized gases (plasmas) was compared to the sterilization methods using gamma and beta radiations. The changes to both the physical and chemical properties of the sterilized exopolysaccharides were analyzed. The use of ethylene oxide can be recommended for the sterilization of polysaccharides as a weak effect on both rheological and structural properties was observed. This low-temperature gas sterilizing process is very efficient, giving a good Sterility Assurance Level (SAL), and is also well suited to large-scale compound manufacturing in the pharmaceutical industry.

  12. In vivo oxidation and surface damage in retrieved ethylene oxide-sterilized total knee arthroplasties.

    Science.gov (United States)

    MacDonald, Daniel; Hanzlik, Josa; Sharkey, Peter; Parvizi, Javad; Kurtz, Steven M

    2012-07-01

    Gas sterilization (eg, ethylene oxide [EtO] and gas plasma) was introduced for polyethylene to reduce oxidation due to free radicals occurring during radiation sterilization. Recently, oxidation has been observed in polyethylenes with undetectable levels of free radicals, which were expected to be oxidatively stable. It is unclear whether in vivo oxidation will occur in unirradiated inserts sterilized with EtO. We analyzed the oxidation, mechanical behavior, and surface damage mechanisms of tibial inserts of a single design sterilized using EtO. We collected 20 EtO-sterilized tibial inserts at revision surgeries. We assessed oxidative using Fourier transform infrared spectroscopy and mechanical properties using the small punch test. Surface damage was assessed using damage scoring techniques and micro-CT. Oxidation indexes were low and uniform between the regions. The subtle changes did not affect the mechanical properties of the polymer. The dominant surface damage modes included burnishing, abrasion, and third-body wear. There was no evidence of delamination in the retrievals. The retrieved EtO-sterilized UHMWPE retrievals remained stable with respect to both oxidative and mechanical properties for up to 10 years in vivo. We did observe slight measurable amounts of oxidation in the inserts; however, it was far below levels that would be expected to compromise the strength of the polymer. Due to the stable oxidative and mechanical properties, EtO-sterilized tibial components appear to be an effective alternative to gamma-sterilized inserts, at least in short-term implantations.

  13. Low Temperature Atmospheric Pressure Plasma Sterilization Shower

    Science.gov (United States)

    Gandhiraman, R. P.; Beeler, D.; Meyyappan, M.; Khare, B. N.

    2012-10-01

    Low-temperature atmospheric pressure plasma sterilization shower to address both forward and backward biological contamination issues is presented. The molecular effects of plasma exposure required to sterilize microorganisms is also analysed.

  14. Sterile Neutrino Search with MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Devan, Alena V. [College of William and Mary, Williamsburg, VA (United States)

    2015-08-01

    MINOS, Main Injector Neutrino Oscillation Search, is a long-baseline neutrino oscillation experiment in the NuMI muon neutrino beam at the Fermi National Accelerator Laboratory in Batavia, IL. It consists of two detectors, a near detector positioned 1 km from the source of the beam and a far detector 734 km away in Minnesota. MINOS is primarily designed to observe muon neutrino disappearance resulting from three flavor oscillations. The Standard Model of Particle Physics predicts that neutrinos oscillate between three active flavors as they propagate through space. This means that a muon-type neutrino has a certain probability to later interact as a different type of neutrino. In the standard picture, the neutrino oscillation probabilities depend only on three neutrino flavors and two mass splittings, Δm2. An anomaly was observed by the LSND and MiniBooNE experiments that suggests the existence of a fourth, sterile neutrino flavor that does not interact through any of the known Standard Model interactions. Oscillations into a theoretical sterile flavor may be observed by a deficit in neutral current interactions in the MINOS detectors. A distortion in the charged current energy spectrum might also be visible if oscillations into the sterile flavor are driven by a large mass-squared difference, ms2 ~ 1 eV2. The results of the 2013 sterile neutrino search are presented here.

  15. Sterile neutrino constraints from cosmology

    DEFF Research Database (Denmark)

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.

    2012-01-01

    The presence of light particles beyond the standard model's three neutrino species can profoundly impact the physics of decoupling and primordial nucleosynthesis. I review the observational signatures of extra light species, present constraints from recent data, and discuss the implications of po...... of possible sterile neutrinos with O(eV)-masses for cosmology....

  16. THE EFFECTS OF A SODIUM-HYPOCHLORITE TREATMENT ON DEMINERALIZED ROOT DENTIN

    NARCIS (Netherlands)

    INABA, D; DUSCHNER, H; JONGEBLOED, W; ODELIUS, H; TAKAGI, O; ARENDS, J

    1995-01-01

    The effects of a 10% NaOCl treatment for 2 min on demineralized human root dentin were investigated by means of: microradiography (MR), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and secondary ion mass spectroscopy (SIMS). MR measurements revealed that NaOCl caused

  17. Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    pain and bacterial or viral contamination. Thus, there is need for development of alternative bone graft materials. The use of osteoinductive materials such as demineralized bone matrix (DBM) alone or in combination with allograft or commercially available human cancellous bone (CB) may substitute allo...

  18. An in vitro biofilm model for enamel demineralization and antimicrobial dose-response studies

    NARCIS (Netherlands)

    Sande, F.H. van de; Azevedo, M.S.; Lund, R.G.; Huysmans, M.C.D.N.J.M.; Cenci, M.S.

    2011-01-01

    Microcosm biofilms formed in microplates have demonstrated complex community dynamics similar to natural dental biofilm. No simplified microcosm models to evaluate enamel demineralization and dose-response effect to anticariogenic therapies have yet been established, thus this study was designed to

  19. Effects of honey, glucose, and fructose on the enamel demineralization depth

    Directory of Open Access Journals (Sweden)

    Fatemeh Ahmadi-Motamayel

    2013-06-01

    Conclusion: The results of this study demonstrated that honey had less caries activity than the other sugars. However, further evidence is required to detect the active components and mechanisms by which it reduces demineralization and to demonstrate whether this food has any clinical application for preventing and reducing dental caries.

  20. Fouling control mechanisms of demineralized water backwash: Reduction of charge screening and calcium bridging effects

    KAUST Repository

    Li, Sheng

    2011-12-01

    This paper investigates the impact of the ionic environment on the charge of colloidal natural organic matter (NOM) and ultrafiltration (UF) membranes (charge screening effect) and the calcium adsorption/bridging on new and fouled membranes (calcium bridging effect) by measuring the zeta potentials of membranes and colloidal NOM. Fouling experiments were conducted with natural water to determine whether the reduction of the charge screening effect and/or calcium bridging effect by backwashing with demineralized water can explain the observed reduction in fouling. Results show that the charge of both membranes and NOM, as measured by the zeta potential, became more negative at a lower pH and a lower concentration of electrolytes, in particular, divalent electrolytes. In addition, calcium also adsorbed onto the membranes, and consequently bridged colloidal NOM and membranes via binding with functional groups. The charge screening effect could be eliminated by flushing NOM and membranes with demineralized water, since a cation-free environment was established. However, only a limited amount of the calcium bridging connection was removed with demineralized water backwashes, so the calcium bridging effect mostly could not be eliminated. As demineralized water backwash was found to be effective in fouling control, it can be concluded that the reduction of the charge screening is the dominant mechanism for this. © 2011 Elsevier Ltd.

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    A study was performed to evaluate regeneration of defects in rat calvaria either unfilled or filled with a bioerodible polyorthoester only, demineralized bone only, or a composite of both. At 4 weeks, histological and radiographic studies showed that defects filled with a composite of bioerodible...

  2. Bone induction by composite of bioerodible polyorthoester and demineralized bone matrix in rats

    DEFF Research Database (Denmark)

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

    1991-01-01

    A composite of a local, sustained, drug-release system, Alzamer bioerodible polyorthoester, and demineralized bone-matrix (DBM) particles implanted in the abdominal muscle of 89 Wistar rats induced cartilage and bone formation at the same rate as DBM when evaluated histologically and by 85Sr upta...

  3. Effect of fluoridated milk on enamel demineralization adjacent to fixed orthodontic appliances

    DEFF Research Database (Denmark)

    Sköld-Larsson, Kerstin; Sollenius, Ola; Karlsson, Lena

    2012-01-01

    Abstract Objective. To investigate the effect of daily intake of fluoridated milk on enamel demineralization adjacent to fixed orthodontic brackets assessed with quantitative light-induced fluorescence (QLF). Materials and methods. Sixty-four healthy adolescents (13-18 years) undergoing orthodontic...

  4. The effects of single application of pastes containing ion-releasing particles on enamel demineralization.

    Science.gov (United States)

    Iijima, Masahiro; Kawaguchi, Kyotaro; Kawamura, Naohiko; Ito, Shuichi; Saito, Takashi; Mizoguchi, Itaru

    2017-07-26

    We investigated single application of pastes containing a surface reaction-type pre-reacted glass-ionomer (S-PRG) filler on enamel demineralization. Human enamel blocks were polished using pastes containing S-PRG filler (0, 5, and 30%) and immersed in demineralizing solution for 5 days with daily change of solutions. The pH measurement and nanoindentation testing was carried out during the immersion period, and the enamel surfaces were examined using scanning electron microscopy and atomic force microscopy. A non-fluoride paste and a hydroxyapatite-containing paste were used for comparison. The specimens polished with the S-PRG filler-containing paste exhibited acid-neutralizing properties, which became stronger with an increasing S-PRG filler content. Following immersion in the demineralizing solution, specimens polished with the S-PRG filler-containing paste exhibited significantly greater hardness and elastic modulus values than those polished with the other pastes and exhibited a smoother surface than did the other specimens. Pastes containing S-PRG filler inhibits the demineralization of enamel.

  5. Protective effect on enamel demineralization of a CPP-ACP paste: an AFM in vitro study.

    Science.gov (United States)

    Poggio, Claudio; Lombardini, Marco; Dagna, Alberto; Chiesa, Marco; Bianchi, Stefano

    2009-12-01

    The aim of the present in vitro study was the evaluation of a CPP-ACP paste (Tooth Mousse) on preventing dental erosion produced by a soft drink (Coca Cola), using Atomic Force Microscopy (AFM). Thirty extracted human central incisors free of caries were selected and divided in a treatment and a control half. The treatment halves were divided in three groups-group 1: demineralization with soft drink (4 intervals of 2 min); group 2: demineralization with soft drink (4 intervals of 2 min) plus Tooth Mousse; group 3: intact enamel plus Tooth Mousse. In groups 2 and 3 Tooth Mousse was applied for 3 min at 0, 8, 24 and 36 h. The surface of each specimen was imaged by AFM and R(rms) values were registered. Among treatment specimens of groups 1 and 2, a statistically significant difference (Ppaste had a protective effect on enamel demineralization. In group 3 no statistically significant difference was registered between exposed and not exposed halves of the specimens. The use of a CPP-ACP paste had a protective effect on enamel demineralization in an in vitro model.

  6. Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching.

    Science.gov (United States)

    Ghanbarzadeh, Majid; Ahrari, Farzaneh; Akbari, Majid; Hamzei, Haniye

    2015-07-01

    There is little data regarding the effect of tooth whitening on microhardness of white spot lesions. This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel. Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both groups. Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (phome bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on bleached demineralized enamel. Key words:White spot lesion, bleaching, laser, microhardness, demineralized enamel, home bleaching, in-office bleaching.

  7. In vitro inhibition of bovine enamel demineralization by enamel matrix derivative.

    Science.gov (United States)

    Ran, Jin Mei; Ieong, Cheng Cheng; Xiang, Chen Yang; Lv, Xue Ping; Xue, Jing; Zhou, Xue Dong; Li, Wei; Zhang, Ling Lin

    2014-01-01

    This study aimed to determine whether enamel matrix derivative (Emdogain) affects the demineralization of bovine enamel in vitro and to assess the agent's anti-caries potential. Bovine enamel blocks were prepared and randomly divided into three groups (n = 15 per group), which were treated with distilled water (negative control), NaF (positive control), or Emdogain. All three groups were pH-cycled 12 times over 6 days. The percentage of surface enamel microhardness reduction (%SMHR), calcium demineralization rate (CDR), surface roughness, lesion depth and mineral loss after demineralization were examined. Surface morphology of specimens was studied by scanning electron microscopy. The Emdogain and positive control groups showed similar surface roughness, lesion depths and mineral loss, which were significantly lower than those in the negative control group. In addition, the enamel surfaces of both the Emdogain and NaF groups showed much narrower intercrystalline spaces than the surfaces of the negative control group, which exhibited extensive microfractures along the crystal edges. %SMHR differed significantly among all three groups, with the smallest value in the Emdogain group and the greatest in the negative control group. These results indicate that enamel matrix derivative (Emdogain) can significantly inhibit demineralization of bovine enamel in vitro, suggesting that it has potential as an anti-caries agent. © 2013 Wiley Periodicals, Inc.

  8. Efficacy of fluoride varnishes for preventing enamel demineralization after interproximal enamel reduction. Qualitative and quantitative evaluation.

    Directory of Open Access Journals (Sweden)

    Ascensión Vicente

    Full Text Available To evaluate quantitatively and qualitatively the changes produced to enamel after interproximal reduction and subjected to demineralization cycles, after applying a fluoride varnish (Profluorid and a fluoride varnish containing tricalcium phosphate modified by fumaric acid (Clinpro White.138 interproximal dental surfaces were divided into six groups: 1 Intact enamel; 2 Intact enamel + demineralization cycles (DC; 3 Interproximal Reduction (IR; 4 IR + DC; 5 IR + Profluorid + DC; 6 IR + Clinpro White + DC. IR was performed with a 0.5 mm cylindrical diamond bur. The weight percentage of calcium (Ca, phosphorous (P and fluoride (F were quantified by energy-dispersive X-ray spectrometry (EDX. Samples were examined under scanning electron microscopy (SEM.The weight percentage of Ca was significantly higher (p0.05. The weight percentage of P was similar among all six groups (p>0.05. F was detected on 65% of Group 6 surfaces. SEM images of Groups 4 and 6 showed signs of demineralization, while Group 5 did not.Profluorid application acts as a barrier against the demineralization of interproximally reduced enamel.

  9. Voluntary sterilization in Serbia: Unmet need?

    OpenAIRE

    Rašević Mirjana M.

    2002-01-01

    Is voluntary sterilization as a birth control method accepted in Serbia? This is certainly a question that is being imposed for research, regardless of the fact that voluntary sterilization is neither accessible nor promoted. Most importantly because there is no understanding in the social nor political sphere for legalization of voluntary sterilization as a form of birth control, apart from the clear necessity for this, first, step. They are: the recognition that voluntary sterilization is a...

  10. Sterilization influence on PET track membrane properties

    OpenAIRE

    Filippova, Ekaterina Olegovna; Pichugin, Vladimir Fyodorovich; Gradoboev, Aleksandr Vasilyevich; Filippov, Andrey Vladimirovich

    2016-01-01

    Polyethylene terephthalate (PET) track membrane (TM) has a great opportunity to use as a bio implant in ophthalmology's surgery due to its physical and chemical properties and biological comparability. Sterilization of medical implants can change its properties and can influence on regeneration process and success of surgical treatment. We researched influence on the PET track membrane of two sterilization methods wide used in medicine. The first sterilization method was steam sterilization. ...

  11. Reionization in sterile neutrino cosmologies

    Science.gov (United States)

    Bose, Sownak; Frenk, Carlos S.; Hou, Jun; Lacey, Cedric G.; Lovell, Mark R.

    2016-12-01

    We investigate the process of reionization in a model in which the dark matter is a warm elementary particle such as a sterile neutrino. We focus on models that are consistent with the dark matter decay interpretation of the recently detected line at 3.5 keV in the X-ray spectra of galaxies and clusters. In warm dark matter models, the primordial spectrum of density perturbations has a cut-off on the scale of dwarf galaxies. Structure formation therefore begins later than in the standard cold dark matter (CDM) model and very few objects form below the cut-off mass scale. To calculate the number of ionizing photons, we use the Durham semi-analytic model of galaxy formation, GALFORM. We find that even the most extreme 7 keV sterile neutrino we consider is able to reionize the Universe early enough to be compatible with the bounds on the epoch of reionization from Planck. This, perhaps surprising, result arises from the rapid build-up of high redshift galaxies in the sterile neutrino models which is also reflected in a faster evolution of their far-UV luminosity function between 10 > z > 7 than in CDM. The dominant sources of ionizing photons are systematically more massive in the sterile neutrino models than in CDM. As a consistency check on the models, we calculate the present-day luminosity function of satellites of Milky Way-like galaxies. When the satellites recently discovered in the Dark Energy Survey are taken into account, strong constraints are placed on viable sterile neutrino models.

  12. 21 CFR 886.1940 - Tonometer sterilizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tonometer sterilizer. 886.1940 Section 886.1940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... A tonometer sterilizer is an AC-powered device intended to heat sterilize a tonometer (a device used...

  13. 45 CFR 96.73 - Sterilization.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Sterilization. 96.73 Section 96.73 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION BLOCK GRANTS Social Services Block Grants § 96.73 Sterilization. If a State authorizes sterilization as a family planning service, it must comply...

  14. Effect of 2-hydroxyethyl methacrylate pre-treatment on micro-tensile bond strength of resin composite to demineralized dentin.

    Science.gov (United States)

    Doi, J; Itota, T; Torii, Y; Nakabo, S; Yoshiyama, M

    2004-11-01

    The purpose of this study was to evaluate the effect of 2-hydroxyethyl methacrylate (HEMA) application on the micro-tensile bond strength of resin composite to demineralized dentin. Artificially demineralized lesions were formed on bovine dentin surfaces and treated with 10, 30, 50, 70 and 100 wt% HEMA aqueous solution. The surfaces were then applied and covered with SE Bond and AP-X according to the manufacturer's instruction. After immersion in 37 degrees C water for 24 h, bond strength were measured using a universal testing machine. Bond strengths to both demineralized dentin and normal dentin, without HEMA application, were also measured. Scanning electron microscopic (SEM) observation and confocal laser scanning microscopy (CLSM) analysis at the resin-dentin interface were also performed. The bond strength data were statistically compared with anova and Scheffe's test (P < 0.05). Bond strength to demineralized dentin treated with over 30 wt% HEMA aqueous solution were significantly higher than that to demineralized dentin without HEMA application, but significantly lower than that to normal dentin. SEM observation revealed that the hybrid layer and resin-tags thickened and lengthened with HEMA application. In CLSM, the diffusion of adhesive primer into demineralized dentin increased with HEMA application. These results indicated that HEMA application might increase the bond strength to demineralized dentin by the enhancement of resin monomer penetration of HEMA.

  15. Remineralization potential of fully demineralized dentin infiltrated with silica and hydroxyapatite nanoparticles.

    Science.gov (United States)

    Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

    2014-03-01

    This study investigates the potential of a novel guided tissue regeneration strategy, using fully demineralized dentin infiltrated with silica and hydroxyapatite (HA) nanoparticles (NPs), to remineralize dentin collagen that is completely devoid of native hydroxyapatite. Dentin blocks were fully demineralized with 4N formic acid and subsequently infiltrated with silica and HA NPs. The remineralizing potential of infiltrated dentin was assessed following a twelve week exposure to an artificial saliva solution by means of TEM, EDS and micro-CT. Measurements were taken at baseline and repeated at regular intervals for the duration of the study to quantify the P and Ca levels, the mineral volume percentage and mineral separation of the infiltrated dentin specimens compared to sound dentin and non-infiltrated controls. Infiltration of demineralized dentin with nano-HA restored up to 55% of the P and Ca levels at baseline. A local increase in the concentration of calcium phosphate compounds over a period of twelve weeks resulted in a higher concentration in P and Ca levels within the infiltrated specimens when compared to the non-infiltrated controls. Remineralization of demineralized dentin with silica NPs by immersion in artificial saliva was the most effective strategy, restoring 20% of the P levels of sound dentin. Micro-CT data showed a 16% recovery of the mineral volume in dentin infiltrated with silica NPs and a significant decrease in the mineral separation to levels comparable to sound dentin. Demineralized dentin infiltrated with silica NPs appears to encourage heterogeneous mineralization of the dentin collagen matrix following exposure to an artificial saliva solution. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  17. Quality control methods for Aedes albopictus sterile male production.

    Directory of Open Access Journals (Sweden)

    Fabrizio Balestrino

    2017-09-01

    Full Text Available The capacity of the released sterile males to survive, disperse, compete with wild males and inseminate wild females is an essential prerequisite to be evaluated in any area-wide integrated pest management (AW-IPM programs including a sterile insect release method. Adequate quality control tests supported by standardized procedures need to be developed to measure these parameters and to identify and correct potential inappropriate rearing or handling methods affecting the overall male quality. In this study, we report results on the creation and validation of the first quality control devices designed to infer the survival and mating capacity of radio-sterilized Aedes albopictus males through the observation of their flight capacity under restricted conditions (flight organ device and after stress treatment (aspirator device. Results obtained consistently indicate comparable flight capacity and quality parameters between untreated and 35 Gy irradiated males while a negative impact was observed with higher radiation doses at all observation time performed. The male flight capacity registered with the proposed quality control devices can be successfully employed, with different predictive capacities and response time, to infer the adult male quality. These simple and cost-effective tools provide a valuable method to detect and amend potentially sub-standard procedures in the sterile male production line and hence contribute to maintaining optimal quality and field performance of the mosquitoes being released.

  18. Microwave Sterilization and Depyrogenation System

    Science.gov (United States)

    Akse, James R.; Dahl, Roger W.; Wheeler, Richard R., Jr.

    2009-01-01

    A fully functional, microgravity-compatible microwave sterilization and depyrogenation system (MSDS) prototype was developed that is capable of producing medical-grade water (MGW) without expendable supplies, using NASA potable water that currently is available aboard the International Space Station (ISS) and will be available for Lunar and planetary missions in the future. The microwave- based, continuous MSDS efficiently couples microwaves to a single-phase, pressurized, flowing water stream that is rapidly heated above 150 C. Under these conditions, water is rapidly sterilized. Endotoxins, significant biological toxins that originate from the cell walls of gram-negative bacteria and which represent another defining MGW requirement, are also deactivated (i.e., depyrogenated) albeit more slowly, with such deactivation representing a more difficult challenge than sterilization. Several innovations culminated in the successful MSDS prototype design. The most significant is the antenna-directed microwave heating of a water stream flowing through a microwave sterilization chamber (MSC). Novel antenna designs were developed to increase microwave transmission efficiency. These improvements resulted in greater than 95-percent absorption of incident microwaves. In addition, incorporation of recuperative heat exchangers (RHxs) in the design reduced the microwave power required to heat a water stream flowing at 15 mL/min to 170 C to only 50 W. Further improvements in energy efficiency involved the employment of a second antenna to redirect reflected microwaves back into the MSC, eliminating the need for a water load and simplifying MSDS design. A quick connect (QC) is another innovation that can be sterilized and depyrogenated at temperature, and then cooled using a unique flow design, allowing collection of MGW at atmospheric pressure and 80 C. The final innovation was the use of in-line mixers incorporated in the flow path to disrupt laminar flow and increase contact time

  19. Method of sterilization using ozone

    Science.gov (United States)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

    2002-01-01

    Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize, organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganism and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

  20. Conditional Efficacy of Sterilized Intervention

    OpenAIRE

    Jun, Jongbyung

    2008-01-01

    The noise-trading or coordination channel hypothesis implies that sterilized intervention in the foreign exchange market is effective if certain conditions are satisfied, but ineffective otherwise. The hypothesis is tested with a three-regime threshold model and daily data on actual intervention by US and German central banks. The main finding is that if central banks choose the optimal timing in light of the trend-chasing behaviors of noise traders, such strategic intervention is effective i...

  1. Commissioning of the water demineralization plant of Atucha II Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Schonbrod, B.; Grasso, G.; Ormando, M., E-mail: bschonbrod@na-sa.com.ar, E-mail: ggrasso@na-sa.com.ar, E-mail: mormando@na-sa.com.ar [Nucleoelectrica Argentina S.A., Central Nuclear Atucha II, Lima/Zarate, Provincia de Buenos Aires (Argentina); Chocron, M.; Rodriguez, I.; Lagamma, A.M., E-mail: chocron@cnea.gov.ar, E-mail: irodriguez@cnea.gov.ar, E-mail: lagamma@cnea.gov.ar [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

    2010-07-01

    In Argentina there are two operating Nuclear Power Reactors and a third one is being constructed. Embalse NPP is a 648 Mwe CANDU®-600 type pressurized heavy water reactor (PHWR), designed and built by Atomic Energy of Canada (AECL) and in commercial operation since 1984. Atucha I is a Pressurized Vessel Heavy Water Reactor (PVHWR) of 340 Mwe, in operation since 1974, and Atucha II (also PHWR) of 740 Mwe is in advanced construction state, both of them designed by SIEMENS-KWU. All of these Nuclear Power Plants are operated by Nucleoelectrica Argentina (N.A.S.A.). The Comision Nacional de Energia Atomica (C.N.E.A.) is the R and D nuclear institution in the country that, among many other topics, provides technical support to the plants. Although the Atucha II project has suffered some years of delay, pressure tests are expected to be carried out by the end of the year 2010 and in that sense, water chemistry related activities, specifications, chemistry manuals, laboratories organization and personnel training are acquiring importance. The demineralized water needed for the secondary and auxiliary systems is obtained by means of a demineralization plant, which purifies water from Parana River up to nuclear grade. This plant was designed by Degremont in 1979 and consists of a preliminary treatment by coagulation - flocculation and gravel filters, and subsequent demineralization with ion exchange resins. For the commissioning of the demineralization plant, preliminary tests in the chemical laboratory are performed. The flocculator is simulated using a Jar-Test, different coagulants and coagulation aids are tested with the objective of selecting the best product and defining its optimum dosage. The coagulated water is filtered by means of a funnel with filtration paper and sand. The clarified water thus obtained is treated by ion exchange resins, the train consisting of a cationic, an anionic and a mixed bed. The purpose of the laboratory experiments is to test the resins

  2. Near-surface structural examination of human tooth enamel subject to in vitro demineralization and remineralization

    Science.gov (United States)

    Gaines, Carmen Veronica

    The early stages of chemical tooth decay are governed by dynamic processes of demineralization and remineralization of dental enamel that initiates along the surface of the tooth. Conventional diagnostic techniques lack the spatial resolution required to analyze near-surface structural changes in enamel at the submicron level. In this study, slabs of highly-polished, decay-free human enamel were subjected to 0.12M EDTA and buffered lactic acid demineralizing agents and MI Paste(TM) and calcifying (0.1 ppm F) remineralizing treatments in vitro. Grazing incidence x-ray diffraction (GIXD), a technique typically used for thin film analysis, provided depth profiles of crystallinity changes in surface enamel with a resolution better than 100 nm. In conjunction with nanoindentation, a technique gaining acceptance as a means of examining the mechanical properties of sound enamel, these results were corroborated with well-established microscopy and Raman techniques to assess the nanohardness, morphologies and chemical nature of treated enamel. Interestingly, the average crystallite size of surface enamel along its c-axis dimension increased by nearly 40% after a 60 min EDTA treatment as detected by GIXD. This result was in direct contrast to the obvious surface degradation observed by microscopic and confocal Raman imaging. A decrease in nanohardness from 4.86 +/- 0.44 GPa to 0.28 +/- 0.10 GPa was observed. Collective results suggest that mineral dissolution characteristics evident on the micron scale may not be fully translated to the nanoscale in assessing the integrity of chemically-modified tooth enamel. While an intuitive decrease in enamel crystallinity was observed with buffered lactic acid-treated samples, demineralization was too slow to adequately quantify the enamel property changes seen. MI Paste(TM) treatment of EDTA-demineralized enamel showed preferential growth along the a-axis direction. Calcifying solution treatments of both demineralized sample types

  3. A Comparison of Resistance to Enamel Demineralization after Banding with Four Orthodontic Cements: An in vitro Study

    Directory of Open Access Journals (Sweden)

    Santosh Kumar Goje

    2012-01-01

    Conclusion: The teeth banded with the three fluoride releasing cements (conventional GIC, RMGIC, zinc polycarboxylate demonstrated significantly lesser depth of enamel demineralization as measured by depth of dye penetration than did the zinc phosphate and nonbanded and noncemented control group.

  4. Sterile Neutrinos in Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Benjamin J.P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-09-01

    Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system; test-stand measurements of liquid argon optical properties with dissolved impurities; optimization of wavelength-shifting coatings for liquid argon scintillation light detection; testing and deployment of high-voltage surge arrestors to protect TPC field cages; and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin224 ≤ 0.02 at m2 ~ 0.3 eV2, and the LSND and Mini

  5. Sterilization of Fusarium oxysporum by treatment of non-thermalequilibrium plasma in nutrient solution

    Science.gov (United States)

    Yasui, Shinji; Seki, Satoshi; Yoshida, Ryohei; Shoji, Kazuhiro; Terazoe, Hitoshi

    2016-01-01

    Fusarium wilt of spinach due to F. oxysporum infection is one of the most destructive root diseases in hydroponics in factories using the nutrient film technique. We investigated new technologies for the sterilization of microconidia of F. oxysporum by using a non-thermalequilibrium plasma treatment method in nutrient solution. Specifically, we investigated the sterilization capabilities of five types of gas (air, O2, N2, He, and Ar) used for plasma generation. The highest sterilization capability was achieved by using O2 plasma. However, ozone, which causes growth inhibition, was then generated and released into the atmosphere. The sterilization capability was lower when N2 or air plasma was used in the nutrient solution. It was confirmed that sterilization can be achieved by plasma treatment using inert gases that do not generate ozone; therefore, we determined that Ar plasma is the most preferable. In addition, we investigated the sterilization capabilities of other factors associated with Ar plasma generation, without direct plasma treatment. However, none of these other factors, which included Ar bubbling, pH reduction, increased temperature, hydrogen peroxide concentration, and UV radiation, could completely reproduce the results of direct plasma treatment. We assume that radicals such as O or OH may contribute significantly to the sterilization of microconidia of F. oxysporum in a nutrient solution.

  6. Floating rGO-based black membranes for solar driven sterilization.

    Science.gov (United States)

    Zhang, Yao; Zhao, Dengwu; Yu, Fan; Yang, Chao; Lou, Jinwei; Liu, Yanming; Chen, Yingying; Wang, Zhongyong; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

    2017-12-14

    This paper presents a new steam sterilization approach that uses a solar-driven evaporation system at the water/air interface. Compared to the conventional solar autoclave, this new steam sterilization approach via interfacial evaporation requires no complex system design to bear high steam pressure. In such a system, a reduced graphene oxide/polytetrafluoroethylene composite membrane floating at the water/air interface serves as a light-to-heat conversion medium to harvest and convert incident solar light into localized heat. Such localized heat raises the temperature of the membrane substantially and helps generate steam with a temperature higher than 120 °C. A sterilization device that takes advantage of the interfacial solar-driven evaporation system was built and its successful sterilization capability was demonstrated through both chemical and biological sterilization tests. The interfacial evaporation-based solar driven sterilization approach offers a potential low cost solution to meet the need for sterilization in undeveloped areas that lack electrical power but have ample solar radiation.

  7. Morphological and chemical changes of dentin after applying different sterilization methods

    Directory of Open Access Journals (Sweden)

    Cláudio Antonio Talge Carvalho

    Full Text Available Aim The present study evaluated the morphological and chemical changes of dentin produced by different sterilization methods, using scanning electron microscopy (SEM and energy-dispersive X-ray spectrometry (EDS analysis. Material and method Five human teeth were sectioned into 4 samples, each divided into 3 specimens. The specimens were separated into sterilization groups, as follows: wet heat under pressure; cobalt 60 gamma radiation; and control (without sterilization. After sterilization, the 60 specimens were analyzed by SEM under 3 magnifications: 1500X, 5000X, and 10000X. The images were analyzed by 3 calibrated examiners, who assigned scores according to the changes observed in the dentinal tubules: 0 = no morphological change; 1, 2 and 3 = slight, medium and complete obliteration of the dentinal tubules. The chemical composition of dentin was assessed by EDS, with 15 kV incidence and 1 μm penetration. Result The data obtained were submitted to the statistical tests of Kruskall-Wallis and ANOVA. It was observed that both sterilization methods – with autoclave and with cobalt 60 gamma radiation – produced no significant changes to the morphology of the dentinal tubules or to the chemical composition of dentin. Conclusion Both methods may thus be used to sterilize teeth for research conducted in vitro.

  8. Evaluation of osteoinduction properties of the demineralized bovine foetal growth plate powder as a new xenogenic biomaterial in rat.

    Science.gov (United States)

    Bigham, A S; Shadkhast, M; Bigham Sadegh, A; Shafiei, Z; Lakzian, A; Khalegi, M R

    2011-10-01

    The aim of this study was evaluation of osteoinductive properties of demineralized bovine foetal growth plate in submuscular transplantation (ectopic osteoinduction) as a new xenogenic biomaterial in rat model. Demineralized bovine foetal growth plate was ectopically implanted in 18 male Sprague-Dawley rats. In 18 of the animals under aseptic conditions two submuscular pouches were created between external and internal oblique abdominal muscles in the two flanks: the right was left empty (sham) and the left was filled with 20mg of demineralized bovine foetal growth plate powder. Radiographs were taken in 2, 4 and 6 weeks after the surgery, then six animals were pharmacologically euthanized after 2, 4 and 6 weeks for histopathological evaluation. Results showed: (1) osteoinductivity of xenogenic demineralized bovine foetal growth plate powder, and (2) earlier mineralization of ectopically implanted demineralized bovine foetal growth plate in the submuscular implanted area. Our results show that submuscular implantation of xenogenic demineralized bovine foetal growth plate has osteoinductive properties in a rat model. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Potential mechanism for the laser-fluoride effect on enamel demineralization.

    Science.gov (United States)

    Liu, Y; Hsu, C-Y S; Teo, C M J; Teoh, S H

    2013-01-01

    Laser-induced prevention of dental caries has been studied extensively. However, the cariostatic mechanisms of a combined fluoride-laser treatment are not well-understood. Using micro- computed tomography (micro-CT), we quantified the effect of fluoride and/or Er:YAG laser treatment on enamel demineralization. The mean mineral loss (%/V) for each group was 4,870 ± 1,434 (fluoride followed by laser treatment), 6,341 ± 2,204 (laser treatment), 7,669 ± 2,255 (fluoride treatment), and 10,779 ± 2,936 (control). The preventive effect of the laser (p enamel hydroxyapatite into fluoridated hydroxyapatite to reduce enamel solubility as a preventive treatment for enamel demineralization.

  10. Photothermal radiometry and modulated luminescence examination of demineralized and remineralized dental lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hellen, A; Mandelis, A [Center for Advanced Diffusion-Wave Technologies, University of Toronto, 5 King' s College Road, Toronto, Ontario, M5S 3G8 (Canada); Finer, Y, E-mail: mandelis@mie.utoronto.c [Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ontario, M5G 1G6 (Canada)

    2010-03-01

    Dental caries involves continuous challenges of acid-induced mineral loss and a counteracting process of mineral recovery. As an emerging non-destructive methodology, photothermal radiometry and modulated luminescence (PTR-LUM) has shown promise in measuring changes in tooth mineral content. Human molars (n=37) were subjected to demineralization in acid gel (pH 4.5, 10 days), followed by incubation in remineralisation solutions (pH 6.7, 4 weeks) without or with fluoride (1 or 1000 ppm). PTR-LUM frequency scans (1 Hz - 1 kHz) were performed prior to and during demineralization and remineralization treatments. Transverse Micro-Radiography (TMR) analysis followed at treatment conclusion. The non-fluoridated group exhibited opposite amplitude and phase trends to those of the highly fluoridated group: smaller phase lag and larger amplitude. These results point to a complex interplay between surface and subsurface processes during remineralization, confining the thermal-wave centroid toward the dominating layer.

  11. Detection for demineralization of dental hard tissues using index-sequenced radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Hyun; Park, Young Ho; Kim, Kyung Sook; Park, Jeong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Hun Kuk [Department of Biomedical Engineering, School of Medicine, KyungHee University, Seoul (Korea, Republic of); Choi, Yong Suk; Hwang, Eui Hwan [Department of Oral and Maxillofacial Radiology, Institute of Oral Biology, School of Dentistry, KyungHee University, Seoul (Korea, Republic of)

    2009-06-15

    The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries. This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures.

  12. Morphological/chemical imaging of demineralized dentin layer in its natural, wet state.

    Science.gov (United States)

    Wang, Yong; Yao, Xiaomei

    2010-05-01

    Measuring the structure, composition or suitability for bonding of the acid-etched dentin substrate, especially in its hydrated state, has been a formidable problem. The purpose of this study was to determine the morphological and structural profiles of the dentin demineralized layer measured in its natural wet state using environmental scanning electron microscopy (ESEM) and micro-Raman imaging. The occlusal 1/3 of the crown was removed from nine extracted, unerupted human third molars. Dentin surfaces were abraded with 600-grit SiC sandpaper under water to create smear layers. The prepared dentin surfaces were randomly selected for treatment with the self-etching agent (Adper Prompt L-Pop) or the total-etching agent 35% H(3)PO(4) gel (with/without agitation). Micro-Raman spectra and imaging were acquired at 1-1.5microm spatial resolution at positions perpendicular to the treated surfaces; since this technique is non-destructive, the same specimens were also imaged with ESEM. Specimens were kept wet throughout spectral acquisition and ESEM observations. ESEM could be used to reveal demineralized layers in acid-etched dentin, but the resolution was low and no collagen fibrils were disclosed. The detailed chemical maps/profiles of demineralized dentin layers under wet conditions could be obtained using Raman imaging. It was shown that the mineral existed in the superficial layer of all etched dentin covered with smear layers. The mineral was much easier to be removed underneath the superficial layer. The depth, degree, and profile of dentin demineralization were dependent on the types of acids (self-etching vs. total etching) and application procedures (with vs. without agitation). Most current adhesives are applied using wet bonding techniques in which the dentin is kept fully hydrated throughout the bonding. Our ability to fully characterize the hydrated, etched dentin substrates is very important for understanding bonding under in vivo conditions. 2010 Academy of

  13. Histologic study of bone-forming capacity on polydeoxyribonucleotide combined with demineralized dentin matrix

    OpenAIRE

    Kim, Seok-Kon; Huh, Chang-Kyu; Lee, Jae-Hoon; Kim, Kyung-Wook; Kim, Moon-Young

    2016-01-01

    Background This study examined the osteoinductive activity of demineralized dentin matrix (DDM) from human and polydeoxyribonucleotide (PDRN) for nude mice. Methods Twenty healthy nude mice, weighing about 15~20?g, were used for the study. DDM from human and PDRN were prepared and implanted subcutaneously into the dorsal portion of the nude mice. The nude mice were sacrificed at 1, 2, and 4?weeks after grafting and evaluated histologically by hematoxylin-eosin and Masson?s trichrome staining....

  14. Demineralized Bone Matrix to Augment Tendon-Bone Healing: A Systematic Review.

    Science.gov (United States)

    Hexter, Adam T; Pendegrass, Catherine; Haddad, Fares; Blunn, Gordon

    2017-10-01

    Following injury to the rotator cuff and anterior cruciate ligament, a direct enthesis is not regenerated, and healing occurs with biomechanically inferior fibrous tissue. Demineralized bone matrix (DBM) is a collagen scaffold that contains growth factors and is a promising biological material for tendon and ligament repair because it can regenerate a direct fibrocartilaginous insertion via endochondral ossification. To provide a comprehensive review of the literature investigating the use of DBM to augment tendon-bone healing in tendon repair and anterior cruciate ligament reconstruction (ACLR). Systematic review. Electronic databases (MEDLINE and EMBASE) were searched for preclinical and clinical studies that evaluated the use of DBM in tendon repair and ACLR. Search terms included the following: ("demineralized bone matrix" OR "demineralized cortical bone") AND ("tissue scaffold" OR "tissue engineering" OR "ligament" OR "tendon" OR "anterior cruciate ligament" OR "rotator cuff"). Peer-reviewed articles written in English were included, and no date restriction was applied (searches performed February 10, 2017). Methodological quality was assessed with peer-reviewed scoring criteria. The search strategy identified 339 articles. After removal of duplicates and screening according to inclusion criteria, 8 studies were included for full review (tendon repair, n = 4; ACLR, n = 4). No human clinical studies were identified. All 8 studies were preclinical animal studies with good methodological quality. Five studies compared DBM augmentation with non-DBM controls, of which 4 (80%) reported positive findings in terms of histological and biomechanical outcomes. Preclinical evidence indicates that DBM can improve tendon-bone healing, although clinical studies are lacking. A range of animal models of tendon repair and ACLR showed that DBM can re-create a direct fibrocartilaginous enthesis, although the animal models are not without limitations. Before clinical trials are

  15. Potential inhibition of demineralization in vitro by fluoride-releasing sealants.

    Science.gov (United States)

    Salar, David V; García-Godoy, Franklin; Flaitz, Catherine M; Hicks, M John

    2007-04-01

    The incorporation of fluoride into sealants has been viewed as a viable way to prevent pit-and-fissure caries by potential inhibition of demineralization through the release of fluoride to enamel. The authors conducted a study to examine the effect of a recently introduced fluoride-releasing sealant (ProSeal, Reliance Orthodontic Products, Itasca, Ill.) on enamel demineralization in an in vitro artificial caries system. The authors randomly assigned 45 extracted human third molars to three treatment groups receiving either conventional sealant without fluoride (Group 1), fluoride-releasing sealant (Group 2) or glass ionomer sealant with high fluoride release (Group 3). They placed cavity preparations on the buccal surfaces of the molars and filled them with the assigned material. They placed acid-resistant varnish on the specimens' enamel surfaces to within 1 millimeter of the sealant, leaving a 1-mm rim of sound enamel available for in vitro enamel caries formation. They thermocycled the teeth (500 cycles) in artificial saliva. They subjected the teeth to an in vitro artificial caries challenge for six weeks to produce caries-like lesions in enamel adjacent to the sealant materials. The authors took longitudinal sections from each tooth, immersed them in water and examined them via polarized light microscopy to determine wall lesion frequencies. The mean (+/- standard deviation) lesion depths were 232 +/- 17 micrometers for Group 1, 144 +/- 21 mum for Group 2 and 128 +/- 15 mum for Group 3. The wall lesion frequency was 12 percent for Group 1 and 7 percent for both Groups 2 and 3. There was a significant difference (P sealant substantially reduces the amount of enamel demineralization adjacent to the material. ProSeal provided increased demineralization inhibition compared with a conventional sealant containing no fluoride, but less than that shown by a glass ionomer sealant. ProSeal's physical properties and cariostatic effects may allow for applications beyond

  16. The effect of fluoride toothpaste on root dentine demineralization progression: a pilot study

    Directory of Open Access Journals (Sweden)

    Juliana Nunes Botelho

    2014-02-01

    Full Text Available The anticaries effect of fluoride (F toothpaste containing 1100 µg F/g in reducing enamel demineralization is well established, but its effect on dentine has not been extensively studied. Furthermore, it has been shown that toothpaste containing a high F concentration is necessary to remineralize root dentine lesions, suggesting that a 1100 µg F/g concentration might not be high enough to reduce root dentine demineralization, particularly when dentine is subjected to a high cariogenic challenge. Thus, the aim of this pilot study was to evaluate in situ the effect of F toothpaste, at a concentration of 1100 µg F/g, on dentine demineralization. In a crossover and double-blind study, conducted in two phases of 14 days, six volunteers wore a palatal appliance containing four slabs of bovine root dentine whose surface hardness (SH was previously determined and to which a 10% sucrose solution was applied extra-orally 8×/day. Volunteers used a non-F toothpaste (negative control or F toothpaste (1100 µg F/g, NaF/SiO2 three times a day. On the 10th and 14th days of each phase, two slabs were collected and SH was determined again. Dentine demineralization was assessed as percentage of SH loss (%SHL. The effect of toothpaste was significant, showing lower %SHL for the F toothpaste group (42.0 ± 9.7 compared to the non-F group (62.0 ± 6.4; p 0.05. This pilot study suggests that F toothpaste at 1100 µg F/g is able to decrease dentine caries even under a high cariogenic challenge of biofilm accumulation and sugar exposure.

  17. Methods for calculating the severity of demineralization on tooth surfaces from PS-OCT scans

    Science.gov (United States)

    Le, Michael H.; Darling, Cynthia L.; Fried, Daniel

    2009-02-01

    Several studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively measure the severity of subsurface demineralization in enamel and dentin. The reflectivity in the polarization state orthogonal to the initial linear polarization incident on the tissue is low at sound tissues interfaces and high in demineralized areas that strongly scatter and depolarize the light. The purpose of this study was to develop improved algorithms for assessing the depth and severity of demineralization from PS-OCT scans for use with 2D and 3D tomographic images. Subsurface caries-like lesions of increasing depth and severity were produced in adjoining windows on ten bovine enamel samples by exposure to demineralization over periods of 1 to 4 days. Each sample also had a sound window to be used as a control. PS-OCT scans were acquired for each sample and analyzed using various methods to calculate the lesion depth and area. Algorithms were developed and used to automatically detect the lesion depth and area, and calculate the volume for improved assessment of lesion severity. Both fixed-depth and automatic edge-finding algorithms were able to detect significant differences between each of the days and sound enamel. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth. Mean lesion depths ranged from 40 to 100 µm. This demonstrates the edge-finding algorithm can be used to automatically determine the depth and severity of early lesions for the rapid analysis of PS-OCT images.

  18. Surgical Sterilization, Regret, and Race: Contemporary Patterns*

    Science.gov (United States)

    Shreffler, Karina M.; McQuillan, Julia; Greil, Arthur L.; Johnson, David R.

    2014-01-01

    Surgical sterilization is a relatively permanent form of contraception that has been disproportionately used by Black, Hispanic, and Native American women in the United States in the past. We use a nationally representative sample of 4,609 women ages 25 to 45 to determine whether sterilization continues to be more common and consequential by race for reproductive-age women. Results indicate that Native American and Black women are more likely to be sterilized than non-Hispanic White women, and Hispanic and Native American women are more likely than non-Hispanic White women to report that their sterilization surgeries prevent them from conceiving children they want. Reasons for sterilization differ significantly by race. These findings suggest that stratified reproduction has not ended in the United States and that the patterns and consequences of sterilization continue to vary by race. PMID:25592919

  19. Surgical sterilization, regret, and race: contemporary patterns.

    Science.gov (United States)

    Shreffler, Karina M; McQuillan, Julia; Greil, Arthur L; Johnson, David R

    2015-03-01

    Surgical sterilization is a relatively permanent form of contraception that has been disproportionately used by Black, Hispanic, and Native American women in the United States in the past. We use a nationally representative sample of 4592 women ages 25-45 to determine whether sterilization continues to be more common and consequential by race for reproductive-age women. Results indicate that Native American and Black women are more likely to be sterilized than non-Hispanic White women, and Hispanic and Native American women are more likely than non-Hispanic White women to report that their sterilization surgeries prevent them from conceiving children they want. Reasons for sterilization differ significantly by race. These findings suggest that stratified reproduction has not ended in the United States and that the patterns and consequences of sterilization continue to vary by race. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Effect of starch and sucrose on dental biofilm formation and on root dentine demineralization.

    Science.gov (United States)

    Aires, C P; Del Bel Cury, A A; Tenuta, L M A; Klein, M I; Koo, H; Duarte, S; Cury, J A

    2008-01-01

    The cariogenicity of starch alone or in combination with sucrose is controversial and the effect on dentine demineralization and on the dental biofilm formed has not been explored under controlled conditions. A crossover, single-blind study was conducted in four steps of 14 days each, during which 11 volunteers wore palatal appliance containing 10 slabs of root dentine to which the following treatments were applied extraorally: 2% starch gel-like solution (starch group); 10% sucrose solution (sucrose group); a solution containing 2% starch and 10% sucrose (starch + sucrose group), or 2% starch solution followed by 10% sucrose solution (starch --> sucrose group). On the 14th day of each phase the biofilms were collected for biochemical and microbiological analyses, and dentine demineralization was assessed by hardness. A higher demineralization was found in dentine exposed to sucrose and starch sucrose combinations than to starch alone (p 0.05). The concentrations of soluble and insoluble extracellular polysaccharides (EPS), and the proportion of insoluble EPS, were lower in the biofilm formed in presence of starch (p 0.05). RNA was successfully isolated and purified from in situ biofilms and only biofilms formed in response to sucrose and starch/sucrose combinations showed detectable levels of gtfB and gtfC mRNA. The findings suggest that the combination of starch with sucrose may not be more cariogenic to dentine than sucrose alone. Copyright 2008 S. Karger AG, Basel.

  1. Effect of a calcium glycerophosphate fluoride dentifrice formulation on enamel demineralization in situ.

    Science.gov (United States)

    Tenuta, Livia Maria Andaló; Cenci, Maximiliano Sergio; Cury, Altair A Del Bel; Pereira-Cenci, Tatiana; Tabchoury, Cínthia Pereira Machado; Moi, Gisele Pedroso; Cury, Jaime Aparecido

    2009-10-01

    To evaluate in situ the effect and mechanisms involved in the anticariogenic effect of a calcium glycerophosphate fluoride dentifrice. In a double-blind, crossover design, a non-F dentifrice (negative control), a F dentifrice and a F dentifrice containing 0.13% CaGP were compared regarding the inhibition of enamel demineralization. Both F dentifrices contained 1500 microg F/g (w/w) as sodium monofluorophosphate (MFP). Bovine enamel blocks were mounted in contact with a S. mutans test plaque, in palatal appliances worn by 10 volunteers. 30 minutes after treatment with the dentifrices, a sucrose rinse was performed and enamel demineralization was assessed after an additional 45 minutes. No significant difference was observed among groups in the calcium and inorganic phosphate concentrations in the fluid phase of the test plaque 30 minutes after the dentifrice use (P > 0.05), but F concentration was significantly higher for both F dentifrices (P 0.05). A higher mineral loss was observed for the non-F dentifrice group (P 0.05). Using this in situ model, the findings suggested that CaGP at the concentration tested did not enhance the inhibition of enamel demineralization promoted by F dentifrice.

  2. Influence of EDC on Dentin-Resin Shear Bond Strength and Demineralized Dentin Thermal Properties

    Directory of Open Access Journals (Sweden)

    Lin Tang

    2016-11-01

    Full Text Available This study aimed to evaluate the bonding strength and thermal properties of demineralized dentin with and without EDC treatment. Sound human molars were randomly divided into seven treatment groups (n = 20: control, 80% ethanol, and five EDC ethanol solutions (0.01–1.0 M. In each group, 16 samples were used for bond strength assessment and 4 samples were used for scanning electron microscopy (SEM analysis. A further 70 intact molars were used to obtain a fine demineralized dentin powder, treated with the same solutions and were evaluated the crosslink degree by ninhydrin test and denaturation temperature (Td by differential scanning calorimetry. EDC-treated specimens (<1.0 M had a higher bond strength, especially 0.3 and 0.5 M group, than the control counterpart. There was a significant drop in bond strength of 1.0 M EDC group. SEM revealed a homogeneous and regular interface under all treatments. EDC treatment significantly increased the demineralized dentin cross-link degree and Td compared with the control and ethanol treatments. The 0.3 and 0.5 M treatments showed the highest cross-link degree and Td. In terms of mechnical and theramal properties consideration, 0.3 and 0.5 M EDC solutions may be favorable for when applied with etch-and-rinse adhesives, but it is still needed further long-term study.

  3. Influence of photo-activation source on enamel demineralization around restorative materials

    Directory of Open Access Journals (Sweden)

    Juliana de Oliveira Ferla

    2013-06-01

    Full Text Available This study evaluated the effects of the photoactivation source and restorative material on the development of caries-like lesions on human enamel after an in vitro pH challenge. Enamel cavities were prepared in 36 blocks, which were assigned to two groups according to the restorative material: resin-modified glass ionomer (RMGI and composite resin (CR. Samples were exposed to quartz-tungsten-halogen lamp, argon-ion laser, or light-emitting diode (n = 6. The Knoop microhardness (KHN values of the top surface of all materials were evaluated. Restored enamel blocks were thermocycled and subjected to 10 demineralization-remineralization cycles at 37°C. KHN analysis of the superficial enamel was performed by four indentations located 100 mm from the restoration margin. The material KHN was not affected by the photoactivation source. No significant difference in KHN was noted between CR and RMGI. The enamel surface around RMGI exhibited a higher KHN (272.8 KHN than the enamel around CR (93.3 KHN, regardless of the photoactivation source. Enamel demineralization around the dental restoration was not influenced by the photoactivation source. Less enamel demineralization was observed around the RMGI than around the CR restoration.

  4. Effect of Argon Laser on Enamel Demineralization around Orthodontic Brackets: An In Vitro Study.

    Directory of Open Access Journals (Sweden)

    Amirfarhang Miresmaeili

    2014-08-01

    Full Text Available This study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets.Fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: Groups 1 (control and 2: The brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. Teeth in group 3 were lased with argon laser for 10s before bracket bonding with halogen light. Group 4 was the same as group 3 except that brackets were also bonded with argon laser. In group 5 samples were bonded conventionally, immersed in an artificial caries solution for two days and then irradiated for 10s with argon laser. All samples were subjected to demineralization by artificial caries solution for 10 days. After bracket removal, samples were buccolingually sectioned and evaluated by polarized light microscopy. Decalcified lesion depth in each section was measured by a trained examiner in a blind fashion. Data were analyzed in SPSS 14 using one-way ANOVA and Tukey's HSD post hoc test.The control group showed the greatest mean lesion depth while group 5 revealed the lowest. The laser-treated groups had significantly lower mean lesion depth compared with the control group (P<0.05 except for group 4 (P=0.192.Argon laser irradiation for 10s before or during bracket bonding can increase caries resistance of intact and demineralized enamel.

  5. The influence of HCl concentration and demineralization temperature of Atrina pectinata shells on quality of chitin

    Science.gov (United States)

    Nugroho, Intan Lazuardi; Pursetyo, Kustiawan Tri; Masithah, Endang Dewi

    2017-02-01

    Atrina pectinata is one of shells species widely consumed by people, which means the high consumption will generate the availability of shells in the environment as waste. Chitin can be produced from the shells. Shells contain quite high minerals that it should be demineralized to reduce the mineral content from the shells. This study aimed to determine the effect of HCl concentration and temperature affect chitin characteristics as the result of demineralization process from pen shells. The method based on two steps, there were demineralization and deproteination. This study used Completely Randomized Design (CRD) with two factors, including HCl concentration (2N, 4N, and 6N) and temperature (33°C and 60°C) which consists six combination treatments and three replications. Data was analyzed by using Analysis of Variance (ANOVA) and followed by Duncan's Multiple Range Test. The results showed that interaction of HCl concentration and temperature has significant effect (p<0.05) to ash content of chitin. The use concentration of 6N and 33°C produced the lowest ash content. Characteristics chitin resulted from the treatment of 6N and 33°C produced ash content 25.33% ± 6.82, moisture content 3.67% ± 1.10, yield 0.72% ± 0.12 and protein content 5.86%.

  6. Properties of the "Orgamax" osteoplastic material made of a demineralized allograft bone

    Science.gov (United States)

    Podorognaya, V. T.; Kirilova, I. A.; Sharkeev, Yu. P.; Uvarkin, P. V.; Zhelezny, P. A.; Zheleznaya, A. P.; Akimova, S. E.; Novoselov, V. P.; Tupikova, L. N.

    2016-08-01

    We investigated properties of the "Orgamax" osteoplastic material, which was produced from a demineralized bone, in the treatment of extensive caries, in particular chronic pulpitis of the permanent teeth with unformed roots in children. The "Orgamax" osteoplastic material consists of demineralized bone chips, a collagen additive, and antibiotics. The surface morphology of the "Orgamax" osteoplastic material is macroporous, with the maximum pore size of 250 µm, whereas the surface morphology of the major component of "Orgamax", demineralized bone chips, is microporous, with a pore size of 10-20 µm. Material "Orgamax" is used in the treatment of complicated caries, particularly chronic pulpitis of permanent teeth with unformed roots in children. "Orgamax" filling a formed cavity exhibits antimicrobial properties, eliminates inflammation in the dental pulp, and, due to its osteoconductive and osteoinductive properties, undergoes gradual resorption, stimulates regeneration, and provides replacement of the defect with newly formed tissue. The dental pulp viability is completely restored, which ensures the complete formation of tooth roots with root apex closure in the long-term period.

  7. The inhibitory effect of polyvinylphosphonic acid on functional MMP activities in human demineralized dentin

    Science.gov (United States)

    Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Hoshika, Tomohiro; Tay, Franklin R.; Pashley, David H.

    2010-01-01

    This study examined the use of polyvinylphosphonic acid (PVPA), as a potential matrix metalloproteinase (MMP) inhibitor and how brief cross-linking of demineralized dentin matrix that did not affected its mechanical properties enhanced the anti-MMP activity of PVPA. The anti-MMP potential of five PVPA concentrations (100–3,000 μg/mL) was initially screened using a rhMMP-9 colorimetic assay. Demineralized dentin beams were treated with the same five concentrations of PVPA to collagen and then aged for 30 days in a calcium- and zinc-containing medium. The changes in modulus of elasticity, loss of dry mass and dissolution of collagen peptides via three-point bending, precision weighing and hydroxyproline assay, respectively were measured. All tested PVPA concentrations were highly effective (p<0.05) in inhibiting MMP-9. Aging in the incubation medium did not significantly alter the modulus of elasticity of the five PVPA-treatment groups. Conversely, aged dentin beams from the control group exhibited a significant decline in their modulus of elasticity (p<0.05) over time. Mass loss from dentin beams and the corresponding increase in hydroxyproline of from the medium in the five PVPA treatment groups were significantly lower than the control (p<0.05). PVPA is a potent inhibitor of endogenous MMP activities in demineralized dentin. It may be used as an alternative to chlorhexidine for preventing collagen degradation within hybrid layers to extend the longevity of resin-dentin bonds. PMID:20580949

  8. The influence of topical application of grapeseed extract gel on enamel surface hardness after demineralization

    Science.gov (United States)

    Saragih, D. A.; Herda, E.; Triaminingsih, S.

    2017-08-01

    The aim of this study was to analyze the influence of topical application of 6.5% and 12.5% grapeseed extract gels for duration of application 16 and 32 minutes on the enamel surface hardness following tooth demineralization by an energy drink. The samples were 21 bovine teeth that underwent demineralization by immersion in the energy drink for 5 minutes in an incubator at 37°C. The demineralized specimens were randomly divided into a control group and 2 treatment groups. The control group was immersed in artificial saliva for 6 hours at 37°C, whereas the treatment groups were treated with topical 6.5% and 12.5% grapeseed extract gels for durations of 16 and 32 minutes and then immersed in artificial saliva for 6 hours at 37°C. The hardness was measured with a Knoop hardness tester. Statistical analysis by repeated ANOVA and one-way ANOVA revealed a significant increase in the enamel hardness value (p0.05).

  9. Effects of sterilization methods on the physical, chemical, and biological properties of silk fibroin membranes.

    Science.gov (United States)

    de Moraes, Mariana Agostini; Weska, Raquel Farias; Beppu, Marisa Masumi

    2014-05-01

    Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. Sterilization is a fundamental step in biomaterials processing and it must not jeopardize the functionality of medical devices. The aim of this study was to analyze the influence of different sterilization methods in the physical, chemical, and biological characteristics of dense and porous silk fibroin membranes. Silk fibroin membranes were treated by several procedures: immersion in 70% ethanol solution, ultraviolet radiation, autoclave, ethylene oxide, and gamma radiation, and were analyzed by scanning electron microscopy, Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction, tensile strength and in vitro cytotoxicity to Chinese hamster ovary cells. The results indicated that the sterilization methods did not cause perceivable morphological changes in the membranes and the membranes were not toxic to cells. The sterilization methods that used organic solvent or an increased humidity and/or temperature (70% ethanol, autoclave, and ethylene oxide) increased the silk II content in the membranes: the dense membranes became more brittle, while the porous membranes showed increased strength at break. Membranes that underwent sterilization by UV and gamma radiation presented properties similar to the nonsterilized membranes, mainly for tensile strength and FTIR results. Copyright © 2013 Wiley Periodicals, Inc.

  10. RVNRL and radiation processing in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Siri-Upathum, C. [Department of Nuclear Technology, Faculty of Engineering, Chulalongkorn University, Bangkok (Thailand)

    2000-03-01

    Industrial application of radiation processing in Thailand is gaining wide acceptance. The first private-owned radiation sterilization plant was established in 1984. Commercialization of protective rubber gloves from radiation vulcanized of natural rubber latex (RVNRL) started in 1993. Two new sterilization plants using electron beam accelerator and gamma irradiation were commissioned in 1997 and 1999 respectively. Another gamma sterilization plant is scheduled to operate in the year 2000. Additional electron accelerator is being installed in one operational gamma sterilization plant, for upgrading of gemstones. Research and development at Office of Atomic Energy for Peace (OAEP) and universities has been focused on RVNRL, radiation treatment of sludge, grafting of cassava starch and utilization of irradiated silk protein. Except for RVNRL which has passed to commercial scale, pilot scale of radiation treatment of sludge has achieved its goal to be utilized as new resources for animal feed and fertilizer. (author)

  11. Hysteroscopic Sterilization: History and Current Methods

    Science.gov (United States)

    Greenberg, James A

    2008-01-01

    For many practicing obstetrician-gynecologists, tubal ligation was the gold standard by which female sterilization techniques were measured. Yet gynecologic surgeons have simultaneously sought to occlude the fallopian tubes transcervically to avoid discomfort and complications associated with transabdominal approaches. In this review, the history of transcervical sterilization is discussed. Past, current, and upcoming techniques are reviewed. This article focuses on interval sterilization techniques, thus removing post-vaginal and post-cesarean delivery tubal ligations from the discussion. PMID:19015762

  12. Hysteroscopic sterilization: history and current methods.

    Science.gov (United States)

    Greenberg, James A

    2008-01-01

    For many practicing obstetrician-gynecologists, tubal ligation was the gold standard by which female sterilization techniques were measured. Yet gynecologic surgeons have simultaneously sought to occlude the fallopian tubes transcervically to avoid discomfort and complications associated with transabdominal approaches. In this review, the history of transcervical sterilization is discussed. Past, current, and upcoming techniques are reviewed. This article focuses on interval sterilization techniques, thus removing post-vaginal and post-cesarean delivery tubal ligations from the discussion.

  13. Effects of gamma irradiation dose-rate on sterile male Aedesaegypti

    Science.gov (United States)

    Ernawan, Beni; Tambunan, Usman Sumo Friend; Sugoro, Irawan; Sasmita, Hadian Iman

    2017-06-01

    Aedesaegypti is the most important vector for dengue, yellow fever and Zika viruses. Considering its medical importance, vector population control program utilizing radiation-based sterile insect technique (SIT) is one of the potential methods for preventing and limiting the dispersal of these viruses. The present study was undertaken to evaluate the dose-rates effects of γ-sterilization on quality parameters of sterile males. Males Ae.aegypti at the pupal stage were sterilized by applying 70 Gyγ-rays in varies dose-rates, i.e. 0 (control), 300, 600, 900, 1200 and 1500Gy/h utilizing panoramic irradiator. Adult males that emerged from the pupal stage were assessed for their quality parameters, which are the percentage of emergence, longevity, sterility and mating competitiveness. The results herein indicate that there was no major effect of dose-rate on the percentage of emergence, the data showedthat there were no differences between irradiated males compared with control. Generally, the longevity of irradiated males was lower compared to control. The data also demonstrated that longevity was significantly increased at the dose-rate from 300 to 900Gy/h, then decreased at the dose-rate 900 to 1500 Gy/h. Sterility of irradiated maleswas significantly different compared to control, while there was no significantly different at dose rate 300 to 1500 Gy/h. Mating competitiveness of irradiated males was increased at the dose rate from 300 to 1200 Gy/h, then the value was decreased significantly at the dose rate 1500 Gy/h. The dose-rate effects of γ-sterilization were discussed in the context genetic vector control, in particular, the SIT. The results give information and contribute to better understanding towards γ-sterilization optimization and quality parameters of sterile male Ae. aegypti on SIT methods.

  14. Sterile neutrino dark matter with supersymmetry

    Science.gov (United States)

    Shakya, Bibhushan; Wells, James D.

    2017-08-01

    Sterile neutrino dark matter, a popular alternative to the WIMP paradigm, has generally been studied in non-supersymmetric setups. If the underlying theory is supersymmetric, we find that several interesting and novel dark matter features can arise. In particular, in scenarios of freeze-in production of sterile neutrino dark matter, its superpartner, the sterile sneutrino, can play a crucial role in early Universe cosmology as the dominant source of cold, warm, or hot dark matter, or of a subdominant relativistic population of sterile neutrinos that can contribute to the effective number of relativistic degrees of freedom Neff during big bang nucleosynthesis.

  15. Seeking sterile neutrinos in Finslerian cosmology

    Science.gov (United States)

    Wang, Deng; Meng, Xin-He

    2017-11-01

    For the first time, to search for sterile neutrinos in the framework of Finler geometry, we constrain four cosmological models using the most stringent constraint we can provide so far. We find that the Finslerian massless sterile neutrino model can, respectively, give a better cosmological fit to data and alleviate the current H_0 tension more effectively than the other three models. For the Finslerian massless sterile neutrino model, we obtain the constraint N_eff=3.237^{+0.092}_{-0.185}, which is consistent with Δ N_eff > 0 at the 1.03σ confidence level (CL). This gives a very weak hint of massless sterile neutrinos and may imply the non-existence of massless sterile neutrinos in the Finslerian cosmological setting. For the Finslerian massive sterile neutrino model, we obtain the constraints N_eff=3.143^{+0.064}_{-0.066}, which favors Δ N_eff > 0 at the 1.47σ CL, and m_{ν , sterile}^eff sterile neutrinos are also non-existent in the Finslerian scenarios. Consequently, one may conclude that the sterile neutrinos are possibly non-existent in the Finslerian universe. Our results are compatible with the recent results of the neutrino oscillation experiments implemented by the Daya Bay and MINOS collaborations and the cosmic ray one carried out by the IceCube collaboration.

  16. Safety and efficacy of hysteroscopic sterilization compared with laparoscopic sterilization: an observational cohort study

    OpenAIRE

    Mao, Jialin; Pfeifer, Samantha; Schlegel, Peter; Sedrakyan, Art

    2015-01-01

    Objective To compare the safety and efficacy of hysteroscopic sterilization with the ?Essure? device with laparoscopic sterilization in a large, all-inclusive, state cohort. Design Population based cohort study. Settings Outpatient interventional setting in New York State. Participants Women undergoing interval sterilization procedure, including hysteroscopic sterilization with Essure device and laparoscopic surgery, between 2005 and 2013. Main outcomes measures Safety events within 30 days o...

  17. Sterilization of auto-crosslinked hyaluronic acid scaffolds structured in microparticles and sponges.

    Science.gov (United States)

    Shimojo, Andréa Arruda Martins; de Souza Brissac, Isabela Cambraia; Pina, Lucas Martins; Lambert, Carlos Salles; Santana, Maria Helena Andrade

    2015-01-01

    This work evaluated the effects of UV irradiation, plasma radiation, steam and 70% ethanol treatments on the sterilization and integrity of auto-crosslinked hyaluronic acid (HA-ACP) scaffolds structured in microparticles and sponges aiming in vivo applications for regenerative medicine of bone tissue. The integrity of the microparticles was characterized by rheological behavior, while for the sponges, it was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. The effectiveness of the sterilization treatment was verified by the number of microorganism colonies in the samples after the treatments. In conclusion, plasma radiation was the best treatment for the sponges, while steam sterilization in the autoclave at 126°C (1.5 kgf/cm2) for 5 min was the best treatment for the microparticles.

  18. Sterilization in post-Soviet Russia.

    Science.gov (United States)

    Popov, A

    1994-11-01

    Voluntary contraceptive sterilization was legalized in Russia in the early 1990s after a long history of prohibition. During the years between the end of the 1930s and the early 1990s voluntary sterilization was clandestine. In practice, the period of prohibition came to an end only at the end of 1990, when the Order of the Ministry of Health of the USSR No. 484 on permission for surgical sterilization of women dated December 14, 1990, was published. The very limited official list of social and medical indications for which female sterilization was permitted included the following items: 3 or more children in the family, or over 30 years of age plus 2 children. A second version of the Order of the Ministry of Health of the Russian Federation (No 303) on providing medical sterilization to citizens was published on December 28, 1993. Sterilization was provided only after written agreement of any citizen no younger than 35 years, or if one had no fewer than 2 children. However, in the case of medical indications and with the agreement of the citizen it could be permitted without limitation by age and number of children. Additionally, this Order included similar instructions for sterilization of males. This current Order eliminated the previous Order of the Ministry of Health of the USSR No 484. For the first time medical sterilization was considered a method of family planning. Also for the first time the provision of sterilization was allowed for broad social reasons. The list of medical indications for sterilization now included more than 50 diseases and pathological disorders. It was possible to obtain the operation outside the place of residence. The number of operations increased from 7255 in 1991 to 9660 in 1992. However, the real increase in the number of sterilizations could be much higher because of a great deal of under-reporting, especially outside the big cities.

  19. Sterile neutrinos and the rapid formation of supermassive black holes

    Science.gov (United States)

    Richter, M. C.; Tupper, G. B.; Viollier, R. D.

    2008-11-01

    The most massive black holes, lurking at the centers of large galaxies, must have formed less than a billion years after the big bang, as they are visible today in the form of bright quasars at redshift z gtrsim 6[1]. Their early appearance is mysterious, because the radiation pressure, generated by infalling ionized baryonic matter, inhibits the rapid growth of these black holes from stellar-mass black holes [2]. Here we show that the supermassive black holes may, instead, form timeously through the accretion of degenerate sterile neutrino dark matter onto stellar-mass black holes [3].

  20. Experiment for search for sterile neutrino at SM-3 reactor

    Science.gov (United States)

    Serebrov, A. P.; Ivochkin, V. G.; Samoylov, R. M.; Fomin, A. K.; Zinoviev, V. G.; Neustroev, P. V.; Golovtsov, V. L.; Gruzinsky, N. V.; Solovey, V. A.; Cherniy, A. V.; Zherebtsov, O. M.; Martemyanov, V. P.; Zinoev, V. G.; Tarasenkov, V. G.; Aleshin, V. I.; Petelin, A. L.; Pavlov, S. V.; Izhutov, A. L.; Sazontov, S. A.; Ryazanov, D. K.; Gromov, M. O.; Afanasiev, V. V.; Matrosov, L. N.; Matrosova, M. Yu.

    2016-11-01

    In connection with the question of possible existence of sterile neutrino the laboratory on the basis of SM-3 reactor was created to search for oscillations of reactor antineutrino. A prototype of a neutrino detector with scintillator volume of 400 l can be moved at the distance of 6-11 m from the reactor core. The measurements of background conditions have been made. It is shown that the main experimental problem is associated with cosmic radiation background. Test measurements of dependence of a reactor antineutrino flux on the distance from a reactor core have been made. The prospects of search for oscillations of reactor antineutrino at short distances are discussed.

  1. Chasing the light sterile neutrino with the STEREO detector

    Science.gov (United States)

    Minotti, A.

    2017-09-01

    The standard three-family neutrino oscillation model is challenged by a number of observations, such as the reactor antineutrino anomaly (RAA), that can be explained by the existence of sterile neutrinos at the eV mass scale. The STEREO experiment detects {\\bar ν _e} produced in the 58.3MW Th compact core of the ILL research reactor via inverse beta decay (IBD) interactions in a liquid scintillator. Using 6 identical target cells, STEREO compares {\\bar ν _e} energy spectra at different baselines in order to observe possible distortions due to short-baseline oscillations toward eV sterile neutrinos. IBD events are effectively singled out from γ radiation by selecting events with a two-fold coincidence that is typical of an IBD interaction. External background is reduced by means of layers of shielding material. A Cherenkov veto allows to partially remove background produced by cosmic muons, and the remaining component is measured in reactor-off periods and subtracted statistically. If no evidence of sterile neutrinos after the full statistics of 6 reactor cycles is gathered, STEREO is expected to fully exclude the RAA allowed region.

  2. Sterilization monitoring by biological indicators and conventional swab test of different sterilization processes used in orthodontics: A comparative study

    OpenAIRE

    Shantanu Khattri; Madhvi Bhardwaj; Sunita Shrivastava

    2015-01-01

    Introduction: The need of effective sterilization method and their monitoring is necessary. Biological indicators are specific microorganisms with high resistance toward particular sterilization methods. Their processes include steam autoclave, dry heat sterilizer, ethylene oxide sterilizer. This article has considered various methods to monitor the effectiveness of different sterilization methods used in orthodontics. Materials and Methods: The parameters for comparison were the control and ...

  3. Heat sterilization times of red pine boards

    Science.gov (United States)

    William T. Simpson

    2004-01-01

    The objective of this study was to determine the time required to heat the center of red pine boards to various temperatures for sterilization. This information will serve as a guideline for those concerned with heat sterilizing wood pallets and other wood shipping containers to meet heat treatment requirements for protection against invasive pests. Red pine boards, 4...

  4. 21 CFR 880.6880 - Steam sterilizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Steam sterilizer. 880.6880 Section 880.6880 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... intended for use by a health care provider to sterilize medical products by means of pressurized steam. (b...

  5. Sodium hypochlorite sterilization of culture medium in ...

    African Journals Online (AJOL)

    Micropropagation requires controlling contamination that might compromise the success of the process. Thermal sterilization is traditionally used; however, costs deriving from equipment acquisition and maintenance render this technique costly. With the purpose of finding an alternative to thermal sterilization, this research ...

  6. Light Sterile Neutrinos: A White Paper

    DEFF Research Database (Denmark)

    Abazajian, K. N.; Acero, M. A.; Agarwalla, S. K.

    2012-01-01

    This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.......This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data....

  7. PRINCIPLES OF HEAT STERILIZATION IN DENTAL PRACTICE

    African Journals Online (AJOL)

    PRINCIPLES OF HEAT STERILIZATION. IN DENTAL PRACTICE. W.H. van Palenstein Helderman. Department of Community and Preventive Dentistry,. Faculty of Dentistry, Muhimbili University College of Health Sciences,. Dar es Salaam, Tanzania. Introduction. Sterilization is defined as the destruction of all forms of life ...

  8. Federally funded sterilization: time to rethink policy?

    Science.gov (United States)

    Borrero, Sonya; Zite, Nikki; Creinin, Mitchell D

    2012-10-01

    In the 1970s, concern about coercive sterilization of low-income and minority women in the United States led the US Department of Health, Education, and Welfare to create strict regulations for federally funded sterilization procedures. Although these policies were instituted to secure informed consent and protect women from involuntary sterilization, there are significant data indicating that these policies may not, in fact, ensure that consent is truly informed and, further, may prevent many low-income women from getting a desired sterilization procedure. Given the alarmingly high rates of unintended pregnancy in the United States, especially among low-income populations, we feel that restrictive federal sterilization policies should be reexamined and modified to simultaneously ensure informed decision-making and honor women's reproductive choices.

  9. Sterile neutrinos with non-standard secret interactions imprints on Cosmic Microwave Background anisotropies

    Science.gov (United States)

    Forastieri, F.

    2017-05-01

    Short baseline laboratory (SBL) anomalies have shown preference for light sterile neutrinos with eV masses. These particles, if confirmed, would be produced in the early universe and would add their contribution to the relativistic energy density basically increasing the effective number of extra relativistic species (N eff). It has been shown that when the matter potential produced by the sterile interactions becomes smaller than the vacuum oscillation frequency, sterile neutrinos are plentifully produced by the scattering effects in the sterile neutrino sector. This behaviour, however, leads to a ΔN eff ≃ 1 which is in tension at 3 - 5σ with the actual constraints given by the latest Cosmic Microwave Background radiation (CMB) observations. In order to avoid the thermalization of eV sterile neutrinos in the early universe, secret interactions between the sterile and active sectors mediated by a massive vector boson (MX 0.1 eV and seem to save the cosmological constraints coming from big-bang nucleosynthesis (BBN) and mass bounds. In this framework, cosmological observations represent a powerful tool to constrain neutrino physics complementary to laboratory experiments. In particular, observations of the CMB have the potential to constrain the properties of relic neutrinos, as well as of additional light relic particles in the universe. In this work we present the effects of the strength of the interaction on the neutrino fluid perturbations and on the CMB anisotropies power spectrum.

  10. Sterile neutrinos with eV masses in cosmology — How disfavoured exactly?

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, Jan; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Raffelt, Georg G. [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Wong, Yvonne Y.Y., E-mail: hamann@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: raffelt@mppmu.mpg.de, E-mail: yvonne.wong@physik.rwth-aachen.de [Institut für Theoretische Teilchenphysik und Kosmologie, RWTH Aachen, D-52056 Aachen (Germany)

    2011-09-01

    We study cosmological models that contain sterile neutrinos with eV-range masses as suggested by reactor and short-baseline oscillation data. We confront these models with both precision cosmological data (probing the CMB decoupling epoch) and light-element abundances (probing the BBN epoch). In the minimal ΛCDM model, such sterile neutrinos are strongly disfavoured by current data because they contribute too much hot dark matter. However, if the cosmological framework is extended to include also additional relativistic degrees of freedom beyond the three standard neutrinos and the putative sterile neutrinos, then the hot dark matter constraint on the sterile states is considerably relaxed. A further improvement is achieved by allowing a dark energy equation of state parameter w < −1. While BBN strongly disfavours extra radiation beyond the assumed eV-mass sterile neutrino, this constraint can be circumvented by a small ν{sub e} degeneracy. Any model containing eV-mass sterile neutrinos implies also strong modifications of other cosmological parameters. Notably, the inferred cold dark matter density can shift up by 20–75% relative to the standard ΛCDM value.

  11. Sterilization of collagen scaffolds designed for peripheral nerve regeneration: Effect on microstructure, degradation and cellular colonization.

    Science.gov (United States)

    Monaco, Graziana; Cholas, Rahmatullah; Salvatore, Luca; Madaghiele, Marta; Sannino, Alessandro

    2017-02-01

    In this study we investigated the impact of three different sterilization methods, dry heat (DHS), ethylene oxide (EtO) and electron beam radiation (β), on the properties of cylindrical collagen scaffolds with longitudinally oriented pore channels, specifically designed for peripheral nerve regeneration. Scanning electron microscopy, mechanical testing, quantification of primary amines, differential scanning calorimetry and enzymatic degradation were performed to analyze possible structural and chemical changes induced by the sterilization. Moreover, in vitro proliferation and infiltration of the rat Schwann cell line RSC96 within the scaffolds was evaluated, up to 10days of culture. No major differences in morphology and compressive stiffness were observed among scaffolds sterilized by the different methods, as all samples showed approximately the same structure and stiffness as the unsterilized control. Proliferation, infiltration, distribution and morphology of RSC96 cells within the scaffolds were also comparable throughout the duration of the cell culture study, regardless of the sterilization treatment. However, we found a slight increase of chemical crosslinking upon sterilization (EtOsterilized scaffolds. The results demonstrated that β irradiation impaired the scaffold properties to a greater extent, whereas EtO exposure appeared as the most suitable method for the sterilization of the proposed scaffolds. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Effect of sterilization procedures on properties of plasma polymers relevant to biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Artemenko, A. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Kylian, O., E-mail: ondrej.kylian@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Choukourov, A.; Gordeev, I.; Petr, M. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Vandrovcova, M. [Institute of Physiology, Academy of Sciences of the Czech Republic, Department of Growth and Differentiation of Cell Populations, Videnska 1083, 142 20, Prague 4 (Czech Republic); Polonskyi, O. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Bacakova, L. [Institute of Physiology, Academy of Sciences of the Czech Republic, Department of Growth and Differentiation of Cell Populations, Videnska 1083, 142 20, Prague 4 (Czech Republic); Slavinska, D.; Biederman, H. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic)

    2012-10-01

    This study is focused on the evaluation of resistance of plasma polymers toward common sterilization techniques, i.e. property important for possible use of such materials in biomedical applications. Three kinds of plasma polymers having different bioadhesive natures were studied: plasma polymerized poly(ethylene oxide), fluorocarbon plasma polymers, and nitrogen-rich plasma polymers. These plasma polymers were subjected to dry heat, autoclave and UV radiation treatment. Their physical, chemical and bioresponsive properties were determined by means of different techniques (ellipsometry, atomic force microscopy, wettability measurements, X-ray photoelectron spectroscopy and biological tests with osteoblast-like cells MG63). The results clearly show that properties of thin films of plasma polymers may be significantly altered by a sterilization process. Moreover, observed changes induced by selected sterilization methods were found to depend strongly on the sterilized plasma polymer. - Highlights: Black-Right-Pointing-Pointer Effect of common sterilization methods on three kinds of plasma polymers is studied. Black-Right-Pointing-Pointer Physical, chemical and bioresponsive properties of plasma polymers are analyzed. Black-Right-Pointing-Pointer Changes induced by sterilization depend strongly on type of the plasma polymer.

  13. The strongest bounds on active-sterile neutrino mixing after Planck data

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Alessandro [II Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Mangano, Gianpiero [Istituto Nazionale di Fisica Nucleare – Sezione di Napoli, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy); Saviano, Ninetta, E-mail: ninetta.saviano@desy.de [II Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Istituto Nazionale di Fisica Nucleare – Sezione di Napoli, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy); Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy); Borriello, Enrico [II Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Giunti, Carlo [Department of Physics, University of Torino and INFN, Via P. Giuria 1, I-10125 Torino (Italy); Miele, Gennaro; Pisanti, Ofelia [Istituto Nazionale di Fisica Nucleare – Sezione di Napoli, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy); Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, I-80126 Napoli (Italy)

    2013-10-07

    Light sterile neutrinos can be excited by oscillations with active neutrinos in the early universe. Their properties can be constrained by their contribution as extra-radiation, parameterized in terms of the effective number of neutrino species N{sub eff}, and to the universe energy density today Ω{sub ν}h{sup 2}. Both these parameters have been measured to quite a good precision by the Planck satellite experiment. We use this result to update the bounds on the parameter space of (3+1) sterile neutrino scenarios, with an active-sterile neutrino mass squared splitting in the range (10{sup −5}–10{sup 2}) eV{sup 2}. We consider both normal and inverted mass orderings for the active and sterile states. For the first time we take into account the possibility of two non-vanishing active-sterile mixing angles. We find that the bounds are more stringent than those obtained in laboratory experiments. This leads to a strong tension with the short-baseline hints of light sterile neutrinos. In order to relieve this disagreement, modifications of the standard cosmological scenario, e.g. large primordial neutrino asymmetries, are required.

  14. Theoretical approach to the destruction or sterilization of drugs in aqueous solution

    Science.gov (United States)

    Slegers, Catherine; Tilquin, Bernard

    2005-02-01

    Two novel applications in the radiation processing of aqueous solutions of drugs are the sterilization of injectable drugs and the decontamination of hospital wastewaters by ionizing radiation. The parameters influencing the destruction of the drug in aqueous solutions are studied with a computer simulation program. This theoretical approach has revealed that the dose rate is the most important parameter that can be easily varied in order to optimize the destruction or the protection of the drug.

  15. [Study of the effect of fluor protector on resistance to demineralization of milk beverages on enamel of primary teeth].

    Science.gov (United States)

    Xu, Qiang; Zhang, Wen-ru; Meng, He; Wang, Lin

    2014-02-01

    To study the effect of fluor protector against demineralization of deciduous teeth enamel surface in milk beverages, to certify the mechanism of anti-demineralization of fluor protector, and provide laboratory basis for clinical practice of fluor protector and the prevention of infants and young children. The enamel surfaces of 30 prepared deciduous teeth without caries were randomly divided into 3 groups. Group A was control group. Milk beverages were used in group B, and 0.1% fluor protector was used in group C. Each group included 10 specimens. All specimens were soaked in water tank at 37 degrees centigrade for 4 days, but specimens in groups B and C were soaked at intervals in 10mL yogurt drinks in water tank at 37 degrees centigrade, 9 minutes for one time and 3 times for one day. Scanning electron microscope (SEM) and spectrum analyzer were used to detect the changes in surface morphology of deciduous teeth enamel surface. The concentration values and the ratio of calcium/phosphorus were analyzed with SPSS11.5 software package. Enamel soaked in milk beverages had decreased Ca(2+) and P(3+) content significantly (Penamel in group C was significantly higher than in group B (Penamel surface in group C had mild demineralization. Milk beverages can cause a strong acid demineralization in deciduous teeth enamel surface. The application of fluor protector in enamel surface can inhibit enamel demineralization in the milk beverages.

  16. Effect of glucose on fatigue-induced changes in the microstructure and mechanical properties of demineralized bovine cortical bone.

    Science.gov (United States)

    Trębacz, Hanna; Zdunek, Artur; Wlizło-Dyś, Ewa; Cybulska, Justyna; Pieczywek, Piotr

    2015-10-16

    The aim of this study was to test a hypothesis that fatigue-induced weakening of cortical bone was intensified in bone incubated in glucose and that this weakening is revealed in the microstructure and mechanical competence of the bone matrix. Cubic specimens of bovine femoral shaft were incubated in glucose solution (G) or in buffer (NG). One half of G samples and one half of NG were axially loaded in 300 cycles (30 mm/min) at constant deformation (F); the other half was a control (C). Samples from each group (GF, NGF, GC, NGC) were completely demineralized. Slices from demineralized samples were used for microscopic image analysis. A combined effect of glycation and fatigue on demineralized bone was tested in compression (10 mm/min). Damage of samples during the test was examined in terms of acoustic emission analysis (AE). During the fatigue procedure, resistance to loading in glycated samples decreased by 14.5% but only by 8.1% in nonglycated samples. In glycated samples fatigue resulted in increased porosity with pores significantly larger than in the other groups. Under compression, strain at failure in demineralized bone was significantly affected by glucose and fatigue. AE from demineralized bone matrix was considerably related to the largest pores in the tissue. The results confirm the hypothesis that the effect of fatigue on cortical bone tissue was intensified after incubation in glucose, both in the terms of the mechanical competence of bone tissue and the structural changes in the collagenous matrix of bone.

  17. Combining casein phosphopeptide-amorphous calcium phosphate with fluoride: synergistic remineralization potential of artificially demineralized enamel or not?

    Science.gov (United States)

    Elsayad, Iman; Sakr, Amal; Badr, Yahia

    2009-07-01

    Recaldent is a product of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). The remineralizing potential of CPP-ACP per se, or when combined with 0.22% Fl gel on artificially demineralized enamel using laser florescence, is investigated. Mesial surfaces of 15 sound human molars are tested using a He-Cd laser beam at 441.5 nm with 18-mW power as an excitation source on a suitable setup based on a Spex 750-M monochromator provided with a photomultiplier tube (PMT) for detection of collected autofluorescence from sound enamel. Mesial surfaces are subjected to demineralization for ten days. The spectra from demineralized enamel are measured. Teeth are divided into three groups according to the remineralizing regimen: group 1 Recaldent per se, group 2 Recaldent combined with fluoride gel and ACP, and group 3 artificial saliva as a positive control. After following these protocols for three weeks, the spectra from the remineralized enamel are measured. The spectra of enamel autofluorescence are recorded and normalized to peak intensity at about 540 nm to compare spectra from sound, demineralized, and remineralized enamel surfaces. A slight red shift occurred in spectra from demineralized enamel, while a blue shift may occur in remineralized enamel. Group 2 shows the highest remineralizing potential. Combining fluoride and ACP with CPP-ACP can give a synergistic effect on enamel remineralization.

  18. Detection of artificial demineralization bordering different types of laminate veneers using visual inspection and storage phosphor radiography.

    Science.gov (United States)

    Cömlekoğlu, Erhan; Önem, Erinç; Dündar Çömlekoğlu, Mine; Baksı, B Güniz; Mert, Ali

    2013-07-01

    The objective of this study is to compare the diagnostic accuracy of visual inspection (VI) and storage phosphor plate (SPP) radiography for the detection of artificial demineralization bordering different laminate veneers. Twenty human maxillary canine teeth were prepared. All-ceramic (A) and hybrid ceramic (H) laminate veneers were fabricated and luted. Veneered teeth were covered except for a circular window on the proximal surface bordering restorations. Teeth were kept in acetic acid buffer to create demineralization and imaged with a SPP system. Ten observers evaluated all teeth first visually then with SPP images for the presence/absence of demineralization. Teeth were examined using scanning electron microscopy (SEM) as well. The accuracy was expressed as the area under the ROC curves (A(z)). Pair-wise comparisons were performed using two-way ANOVA and post hoc t test (p = 0.05). Fleiss kappa (κ) was used for agreement. SPP radiography was better than the VI for both veneers (p = 0.004). The A(z)s of two veneers were different for both VI (p veneers. Enamel demineralizations bordering hybrid and ceramic laminate veneers can be detected better with SPP radiography than VI and detectability was better for all-ceramic veneers than the hybrid ceramic ones. Early detection of enamel demineralizations bordering laminate veneers would result in time-saving and less-invasive treatment methods; therefore, SPP radiography may be recommended in clinically suspicious cases since it provides better diagnostic accuracy.

  19. Steam sterilization and automatic dispensing of [{sup 18}F]fludeoxyglucose (FDG) for injection

    Energy Technology Data Exchange (ETDEWEB)

    Karwath, Pascal [Department of Nuclear Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany) and MC-Pharma GmbH (MCP), Bonn (Germany)]. E-mail: p.karwath@uni-bonn.de; Sartor, Johannes [MC-Pharma GmbH (MCP), Bonn (Germany); Gries, Wolfgang [MC-Pharma GmbH (MCP), Bonn (Germany); Wodarski, Christine [MC-Pharma GmbH (MCP), Bonn (Germany); Dittmar, Claus [MC-Pharma GmbH (MCP), Bonn (Germany); Biersack, Hans J. [Department of Nuclear Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany); Guhlke, Stefan [Department of Nuclear Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany) and MC-Pharma GmbH (MCP), Bonn (Germany)]. E-mail: stefan.guhlke@ukb.uni-bonn.de

    2005-04-01

    For the purpose of implementing steam sterilization of 2-[{sup 18}F]FDG (FDG) in the final container into routine production, we have validated and established a fully automated dispensing and sterilization system, thereby considerably reducing the radiation burden to the personnel. Methods: The commercially available system combines aseptic dispensing of the product solution under a miniaturized laminar flow unit with subsequent steam sterilization, realized by heating of the product in the final containers by an autoclave included in the dispensing unit, thus incorporating current pharmaceutical manufacturing standards for the production of parental radiopharmaceuticals. The efficiency of the used sterilization cycle, the stability of FDG under the conditions of sterilization and the stability of the final product towards radiolysis was investigated with respect to various pH-formulations. Results: The system was found to be fully valid for filling of vials in a laminar flow class A (US-class 100) environment and for sterilization of FDG in the final container. The pH for sterilizing FDG solutions must be slightly acidic to avoid decomposition. A pH of 5.5 appears to be optimal and gives FDG of very high radiochemical purity ({approx}99%). In addition, radiolysis of FDG in solutions of high activity concentration was significantly lower at pH 5.5 than at neutral pH. Conclusion: Terminal sterilization enables the production of FDG in full compliance with GMP-regulations even in Class C or D (US class 10,000 or 100,000) laboratories.

  20. Effects of Treatment with Various Remineralizing Agents on the Microhardness of Demineralized Enamel Surface.

    Science.gov (United States)

    Salehzadeh Esfahani, Kiana; Mazaheri, Romina; Pishevar, Leila

    2015-01-01

    Background and aims. Remineralization of incipient caries is one of the goals in dental health care. The present study aimed at comparing the effects of casein phosphopeptide-amorphous calcium phosphate complex (CPP-ACP), Remin Pro(®), and 5% sodium fluoride varnish on remineralization of enamel lesions. Materials and methods. In this in vitro study, 60 enamel samples were randomly allocated to six groups of 10. After four days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 underwent one-time treatment with fluoride varnish, CPP-ACP, and Remin Pro(®), respectively. Microhardness of groups 4-6 was measured not only after one-month treatment with the above-mentioned materials (for eight hours a day), but also after re-exposing to the demineralizing solution. The results were analyzed by one-way analysis of variance (ANOVA), repeated measures ANOVA, and Fisher's least significant difference (LSD) test. Results . None of the regimens could increase microhardness in groups 1-3. However, one-month treatment regimens in groups 4-6 caused a significant increase in microhardness. The greatest microhardness was detected in the group treated with CPP-ACP (P = 0.001). In addition, although microhardness reduced following re-demineralization in all three groups, the mean reduction was minimum in the CPP-ACP-treated group (P microhardness, the remineralization potential of CPP-ACP was significantly higher than that of Remin Pro(®) and sodium fluoride varnish.

  1. Inhibition of enamel demineralization by buffering effect of S-PRG filler-containing dental sealant.

    Science.gov (United States)

    Kaga, Masayuki; Kakuda, Shinichi; Ida, Yusuke; Toshima, Hirokazu; Hashimoto, Masanori; Endo, Kazuhiko; Sano, Hidehiko

    2014-02-01

    The buffering capacity and inhibitory effects on enamel demineralization of two commercially available dental sealants were evaluated in this study. The effects of filler particles were also examined. Disks of enamel and cured sealant materials of BeautiSealant (silica or S-PRG filler) or Teethmate F-1 were incubated in lactic acid solutions (pH 4.0) for 1-6 d. The pH changes and amounts of ions released in the solutions were assessed, and enamel surfaces were observed using a scanning electron microscope. The pH of the solution with BeautiSealant (S-PRG filler) was neutralized from pH 4.0 to pH 6.1 (after incubation for 1 d) and from pH 4.0 to pH 6.7 (after incubation for 6 d). In addition, no release of calcium ions was detected and the enamel surface was morphologically intact in scanning electron microscopy images. However, the pH of the solution with Teethmate F-1 remained below pH 4.0 during incubation from days 1 to 6. Calcium release was increased in solutions up to and after 6 d of incubation. Scanning electron microscopy images showed that the structures of hydroxyapatite rods were exposed at the specimen surfaces as a result of demineralization. Ions released from S-PRG filler-containing dental sealant rapidly buffered the lactic acid solution and inhibited enamel demineralization. © 2013 Eur J Oral Sci.

  2. The inhibitory effect of polyvinylphosphonic acid on functional matrix metalloproteinase activities in human demineralized dentin.

    Science.gov (United States)

    Tezvergil-Mutluay, Arzu; Agee, Kelli A; Hoshika, Tomohiro; Tay, Franklin R; Pashley, David H

    2010-10-01

    This study has examined the use of polyvinylphosphonic acid (PVPA) as a potential matrix metalloproteinase (MMP) inhibitor and how brief cross-linking of demineralized dentin matrix that did not affect its mechanical properties enhanced the anti-MMP activity of PVPA. The anti-MMP potential of five PVPA concentrations (100-3000 microgml(-1)) was initially screened using a rhMMP-9 colorimetic assay. Demineralized dentin beams were treated with the same five concentrations of PVPA to collagen and then aged for 30 days in a calcium- and zinc-containing medium. The changes in modulus of elasticity, loss of dry mass and dissolution of collagen peptides were measured via three-point bending, precision weighing and hydroxyproline assay, respectively. All tested PVPA concentrations were highly effective (P<0.05) in inhibiting MMP-9. Ageing in the incubation medium did not significantly alter the modulus of elasticity of the five PVPA treatment groups. Conversely, aged dentin beams from the control group exhibited a significant decline in their modulus of elasticity (P<0.05) over time. Mass loss from the dentin beams and the corresponding increase in hydroxyproline in the medium in the five PVPA treatment groups were significantly lower than for the control (P<0.05). PVPA is a potent inhibitor of endogenous MMP activities in demineralized dentin. It may be used as an alternative to chlorhexidine to prevent collagen degradation within hybrid layers to extend the longevity of resin-dentin bonds. 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Combination effect of fluoride dentifrices and varnish on deciduous enamel demineralization

    Directory of Open Access Journals (Sweden)

    Alessandra Gatti

    2011-10-01

    Full Text Available The aim of this study was to evaluate the anticaries potential of 500 or 1100 ppm F dentifrices combined with fluoride varnish using a pH-cycling regimen. Seventy primary canines were covered with nail polish, leaving a 4×4 mm window on their buccal surface, and randomly assigned into 7 groups (n = 10: S: sound enamel not submitted to the pH-cycling regimen or treatment; N: negative control, submitted to the pH-cycling regimen without any treatment; D1 and D2: subjected to the pH-cycling regimen and treated twice daily with 1100 or 500 ppm F dentifrice, respectively; VF: fluoride varnish (subjected to F-varnish before and in the middle of the pH-cycling regimen; and VF+D1 and VF+D2. After 10 days, the teeth were sectioned, and enamel demineralization was assessed by cross-sectional hardness at different distances from the dental surface. Data were analyzed using a two-way ANOVA followed by Tukey's test. Dentifrice with 1100 ppm F and the combination of F-varnish with the dentifrices significantly reduced enamel demineralization compared with the negative control (p 0.05. The effect of combining F-varnish with the dentifrices was not greater than the effect of the dentifrices alone (p < 0.05. The data suggest that the combination of F-varnish with dentifrices containing 500 and 1100 ppm F is not more effective in reducing demineralization in primary teeth than the isolated effect of dentifrice containing 1100 ppm F.

  4. New sterilization technologies alternative to ethylene oxide

    Science.gov (United States)

    Tabrizian, Maryam; Lerouge, Sophie; Debrie, Anne; Yahia, L'Hocine

    1997-06-01

    Sterilization of biomedical devices may induce bulk and surface modification, responsible for the decrease or loss of their biofunctionality. Pure ethylene oxide (EO) at low temperature and new alternative techniques such as cold gas plasma sterilization have been developed for heat-sensitive polymers. There is a lack of the knowledge concerning their safety in terms of materials damage and consequences on the biofunctionality of sterilized devices. The objective of our work consists in studying bulk and surface changes in biomedical devices induced by these two sterilization techniques. Samples from PVC, Polyurethane, Polyacrylate and Polyethylene-based medical devices are subjected to 1, 5, and 10 sterilization cycles by Steri-Vac-3M (pure EO), Sterrad-100$TM, J&J (gas plasma + H2O2), and studied by X-rays photoelectron spectroscopy. Preliminary results show an increasing in Oxygen/Carbon ratio by a factor of 1.3 to 4.4 between the first and tenth cycle indicating the surface oxidation by gas plasma sterilization processes. Some changes in C-C chemical bounding are associated with EO sterilization.

  5. The effect of transient proanthocyanidins preconditioning on the cross-linking and mechanical properties of demineralized dentin.

    Science.gov (United States)

    Liu, Ruirui; Fang, Ming; Xiao, Yuhong; Li, Fang; Yu, Lan; Zhao, Sanjun; Shen, Lijuan; Chen, Jihua

    2011-11-01

    Proanthocyanidin-based preconditioners were prepared by adding powdered proanthocyanidins-rich grape seed extract to various solvents at different concentrations. Demineralized dentin specimens were preconditioned for 20, 30, 60 or 120 s, followed by the evaluation of their cross-linking degree, mechanical properties and micromorphology. The cross-linking degree of the demineralized dentin collagen exhibited concentration- and time- dependent increase after preconditioning treatment, irrespective of the preconditioner and the solvent. When treated for the same exposure time, specimens after 15% proanthocyanidins preconditioning resulted in the highest mean ultimate tensile strength compared with all the other groups tested. Five percent glutaraldehyde control group produced the highest cross-linking degree, but the ultimate tensile strength was lower than that of 15% proanthocyanidins group. The field emission scanning electron microscopy confirmed that the demineralized dentin collagen was in a homogeneous and regular arrangement after preconditioning and maintained expanding, regardless of the surface moisture conditions.

  6. Monitoring Demineralization and Subsequent Remineralization of Human Teeth at the Dentin-Enamel Junction with Atomic Force Microscopy.

    Science.gov (United States)

    Lechner, Bob-Dan; Röper, Stephanie; Messerschmidt, Jens; Blume, Alfred; Magerle, Robert

    2015-09-02

    Using atomic force microscopy, we monitored the nanoscale surface morphology of human teeth at the dentin-enamel junction after performing successive demineralization steps with an acidic soft drink. Subsequently, we studied the remineralization process with a paste containing calcium and phosphate ions. Repeated atomic force microscopy imaging of the same sample areas on the sample allowed us to draw detailed conclusions regarding the specific mechanism of the demineralization process and the subsequent remineralization process. The about 1-μm-deep grooves that are caused by the demineralization process were preferentially filled with deposited nanoparticles, leading to smoother enamel and dentine surfaces after 90 min exposure to the remineralizing agent. The deposited material is found to homogeneously cover the enamel and dentine surfaces in the same manner. The temporal evolution of the surface roughness indicates that the remineralization caused by the repair paste proceeds in two distinct successive phases.

  7. In-vitro study investigating influence of toothpaste containing green tea extract on the microhardness of demineralized human enamel

    Science.gov (United States)

    Febrian, K.; Triaminingsih, S.; Indrani, DJ

    2017-08-01

    The aim of this study was to analyze the influence of toothpaste containing green tea extract on the microhardness of demineralized enamel. Human tooth, which was demineralised in citric acid solution, had a toothpaste containing green tea extract of concentration of 5, 10 or 15% application. Microhardness measurement was carried out on each enamel surface of the teeth for initial, after the demineralization and after application of the tooth pastes. It showed that there was significant decrease between enamel microhardness of the teeth at the initial condition and after demineralization. After application of the toothpaste containing green tea extract of each concentration the microhardnss increased significantly. However, there the microhardness was insignificant between the applications of each green tea concentration.

  8. Sterilization of silicone-based hydrogels for biomedical application using ozone gas: Comparison with conventional techniques.

    Science.gov (United States)

    Galante, Raquel; Ghisleni, Daniela; Paradiso, Patrizia; Alves, Vitor D; Pinto, Terezinha J A; Colaço, Rogério; Serro, Ana Paula

    2017-09-01

    Sterilization of hydrogels is challenging due to their often reported sensitivity to conventional methods involving heat or radiation. Although aseptic manufacturing is a possibility, terminal sterilization is safer in biological terms, leading to a higher overall efficiency, and thus should be used whenever it is possible. The main goal of this work was to study the applicability of an innovative ozone gas terminal sterilization method for silicone-based hydrogels and compare its efficacy and effects with those of traditional sterilization methods: steam heat and gamma irradiation. Ozone gas sterilization is a method with potential interest since it is reported as a low cost green method, does not leave toxic residues and can be applied to thermosensitive materials. A hydrogel intended for ophthalmological applications, based on tris(trimethylsiloxy)silyl] propyl methacrylate, was prepared and extensively characterized before and after the sterilization procedures. Alterations regarding transparency, swelling, wettability, ionic permeability, friction coefficient, mechanical properties, topography and morphology and chemical composition were monitored. Efficacy of the ozonation was accessed by performing controlled contaminations and sterility tests. In vitro cytotoxicity testes were also performed. The results show that ozonation may be applied to sterilize the studied material. A treatment with 8 pulses allowed sterilizing the material with bioburdens≤103CFU/mL, preserving all the studied properties within the required known values for contact lenses materials. However, a higher exposure (10 pulses) led to some degradation of the material and induced mild cytotoxicity. Steam heat sterilization led to an increase of swelling capacity and a decrease of the water contact angle. Regarding gamma irradiation, the increase of irradiation dose led to an increase of the friction coefficient. The higher dose (25kGy) originated surface degradation and affected the

  9. Chemical sterilization of allograft dermal tissues.

    Science.gov (United States)

    Phipps, Abigail; Vaynshteyn, Edward; Kowalski, John B; Ngo, Manh-Dan; Merritt, Karen; Osborne, Joel; Chnari, Evangelia

    2017-12-01

    Common terminal sterilization methods are known to alter the natural structure and properties of soft tissues. One approach to providing safe grafts with preserved biological properties is the combination of a validated chemical sterilization process followed by an aseptic packaging process. This combination of processes is an accepted method for production of sterile healthcare products as described in ANSI/AAMI ST67:2011. This article describes the validation of the peracetic acid and ethanol-based (PAAE) chemical sterilization process for allograft dermal tissues at the Musculoskeletal Transplant Foundation (MTF, Edison, NJ). The sterilization capability of the PAAE solution used during routine production of aseptically processed dermal tissue forms was determined based on requirements of relevant ISO standards, ISO 14161:2009 and ISO 14937:2009. The resistance of spores of Bacillus subtilis, Clostridium sporogenes, Mycobacterium terrae, Pseudomonas aeruginosa, Enterococcus faecium, and Staphylococcus aureus to the chemical sterilization process employed by MTF was determined. Using a worst-case scenario testing strategy, the D value was calculated for the most resistant microorganism, Bacillus. The 12D time parameter determined the minimum time required to achieve a SAL of 10 -6 . Microbiological performance qualification demonstrated a complete kill of 10 6 spores at just a quarter of the full cycle time. The validation demonstrated that the PAAE sterilization process is robust, achieves sterilization of allograft dermal tissue to a SAL 10 -6 , and that in combination with aseptic processing secures the microbiological safety of allograft dermal tissue while avoiding structural and biochemical tissue damage previously observed with other sterilization methods such as ionizing irradiation.

  10. Forced sterilization of women as discrimination.

    Science.gov (United States)

    Patel, Priti

    2017-01-01

    There has been a long history of subjecting marginalized women to forced and coerced sterilization. In recent years, the practice has been documented in countries in North and South America, Europe, Asia, and Africa. It has targeted women who are ethnic and racial minorities, women with disabilities, women living with HIV, and poor women. A handful of courts have issued decisions on the recent forced sterilization of marginalized women finding that such actions violate the women's rights. However, they have all failed to address the women's claims of discrimination. The failure to acknowledge that forced sterilization is at its core a violation of the prohibition of discrimination undermines efforts to eradicate the practice. It further fails to recognize that coerced and forced sterilization fundamentally seeks to deny women deemed as "unworthy" the ability to procreate. Four key principles outlined in the human rights in patient care framework highlight the importance of a finding that the prohibition of discrimination was violated in cases of forced sterilization: the need to highlight the vulnerability of marginalized populations to discrimination in health care settings; the importance of the rights of medical providers; the role of the state in addressing systemic human rights violations in health care settings; and the application of human rights to patient care. Based on these principles, it is clear that finding a violation of the prohibition of discrimination in forced sterilization cases is critical in addressing the systemic nature of the practice, acknowledging the marginalization of specific groups and effectively ending forced sterilization through addressing the underlying purpose of the practice. If litigators, non-governmental organizations and judicial officers are mindful of these principles when dealing with cases of forced sterilization, it is likely that they will be better able to eradicate forced sterilization.

  11. EFFECT OF AIR-DRYING ON DEMINERALIZED AND ON SOUND CORONAL HUMAN DENTIN - A STUDY ON DENSITY AND ON LESION SHRINKAGE

    NARCIS (Netherlands)

    ARENDS, J; RUBEN, J

    1995-01-01

    Recently, several papers investigated the linear dimensional changes in dentine after air-drying. This paper pertains to weight changes, volume changes, and density changes caused by air-drying of sound and demineralized intact dentine. The densities of sound and artificially demineralized human

  12. Spore-Forming Bacteria that Resist Sterilization

    Science.gov (United States)

    LaDuc, Myron; Venkateswaran, Kasthuri

    2003-01-01

    A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

  13. Microscope sterility during spine surgery.

    Science.gov (United States)

    Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

    2012-04-01

    Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact

  14. Dose Assurance in Radiation Processing Plants

    DEFF Research Database (Denmark)

    Miller, Arne; Chadwick, K.H.; Nam, J.W.

    1983-01-01

    Radiation processing relies to a large extent on dosimetry as control of proper operation. This applies in particular to radiation sterilization of medical products and food treatment, but also during development of any other process. The assurance that proper dosimetry is performed at the radiat...... at the radiation processing plant can be obtained through the mediation of an international organization, and the IAEA is now implementing a dose assurance service for industrial radiation processing....

  15. Microbiological Load of Ethylene Oxide Sterilized Medical Devices and its Elimination by Cobalt 60 Source.

    Science.gov (United States)

    Bashir, Rasheeda; Afroze, Bakht; Zulfiqar, Hafiza Fizza; Saleem, Resham; Altaf, Imran; Saleem, Faiza; Aslam, Farheen; Naz, Shagufta

    2016-06-01

    To determine the residing microbial flora of ethylene oxide (EtO) sterilized medical devices and optimization of safe dose of gamma radiation (Cobalt 60 source) for the complete elimination of microbial load. Experimental study. Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan from September 2014 to June 2015. Thirty-six samples of EtO sterilized medical devices of same batch of three different companies were collected for this study. Isolation and enumeration of microbes were done by using different selective and differential media. Gram staining and biochemically characterization by API 20 (Bio Merieux, France) kit was done for identification of the microorganisms. The medical devices having high microbial load were sent to Pakistan Radiation Services (PARAS) for gamma irradiations at 3 different selected doses (20 KGy, 25 KGy, and 30 KGy). Different types of Gram positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus andBacillus subtilis) were isolated from the EtO sterilized samples. Gram negative bacteria and fungi were not detected on these medical devices. Gamma irradiations results showed that 30 KGy was optimized dose for complete elimination of microbial flora on endotracheal, Nelaton, and tracheostomy tubes. Gamma radiations (Co 60 source) effectively decontaminate the microbial flora on the equipment previously sterilized by the ethylene oxide gas; and 30 KGy is the optimized dose for all these medical devices.

  16. A comparison of definable traits in women requesting reversal of sterilization and women satisfied with sterilization.

    Science.gov (United States)

    Leader, A; Galan, N; George, R; Taylor, P J

    1983-01-15

    More women of reproductive age are being sterilized. Some of these women regret the decision and subsequently request a reversal of sterilization, whereas others do not. This study was undertaken to develop a profile of easily definable traits of 159 women who requested a reversal of sterilization and compare it with that of 160 women who apparently were satisfied with sterilization. Statistically significant differences were found. Remarriage was the most common cause for regret among women in the group which requested reversal of sterilization. Women in this group married younger, completed their family earlier, and were sterilized at a younger age. These women had significantly fewer live children and had undergone more therapeutic abortions (p less than 0.005).

  17. Demineralized Freeze-Dried Bovine Cortical Bone: Its Potential for Guided Bone Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2017-01-01

    Full Text Available Background. Bovine pericardium collagen membrane (BPCM had been widely used in guided bone regeneration (GBR whose manufacturing process usually required chemical cross-linking to prolong its biodegradation. However, cross-linking of collagen fibrils was associated with poorer tissue integration and delayed vascular invasion. Objective. This study evaluated the potential of bovine cortical bone collagen membrane for GBR by evaluating its antigenicity potential, cytotoxicity, immune and tissue response, and biodegradation behaviors. Material and Methods. Antigenicity potential of demineralized freeze-dried bovine cortical bone membrane (DFDBCBM was done with histology-based anticellularity evaluation, while cytotoxicity was analyzed using MTT Assay. Evaluation of immune response, tissue response, and biodegradation was done by randomly implanting DFDBCBM and BPCM in rat’s subcutaneous dorsum. Samples were collected at 2, 5, and 7 days and 7, 14, 21, and 28 days for biocompatibility and tissue response-biodegradation study, respectively. Result. DFDBCBM, histologically, showed no retained cells; however, it showed some level of in vitro cytotoxicity. In vivo study exhibited increased immune response to DFDBCBM in early healing phase; however, normal tissue response and degradation rate were observed up to 4 weeks after DFDBCBM implantation. Conclusion. Demineralized freeze-dried bovine cortical bone membrane showed potential for clinical application; however, it needs to be optimized in its biocompatibility to fulfill all requirements for GBR membrane.

  18. Demineralized Xenogenic Dentin and Autogenous Bone as Onlay Grafts to Rabbit Tibia.

    Science.gov (United States)

    Al-Asfour, Adel; Farzad, Payam; Al-Musawi, Ala; Dahlin, Christer; Andersson, Lars

    2017-04-01

    The present study was undertaken to evaluate the healing pattern of xenogenic demineralized dentin onlay grafts in comparison with autogenous bone grafts to the rabbit tibia. Eight 6-month-old New Zealand male rabbits were used in the experiments. Standardized sized dentin blocks from human premolars and similar autogenous bone blocks harvested from tibia were grafted as onlay blocks on each tibia (n = 8 × 2). All animals were killed after a healing period of 12 weeks. Healing was uneventful for all animals. In general, both the dentin and bone block grafts were fused to the bone, resorbed, and replaced by bone and connective tissue to a varying degree. Both types of grafts were still present after 12 weeks, on an average to approximately one third of the original sizes. Resorption cavities could be seen in the dentin with bone formation. Zones of osseous replacement resorption of the dentin could be noted. In both graft types, higher rate of bone formation was seen at the interface between graft and recipient site. Demineralized xenogenic dentin onlay grafts showed similar resorption characteristics as autogenous bone onlay grafts, being resorbed in a similar rate during 12 weeks. New bone formation occurred mainly in terms of replacement resorption in the interface between dentin/bone graft and native bone.

  19. Temporal relationship between sucrose-associated changes in dental biofilm composition and enamel demineralization.

    Science.gov (United States)

    Vale, G C; Tabchoury, C P M; Arthur, R A; Del Bel Cury, A A; Paes Leme, A F; Cury, J A

    2007-01-01

    The aim of this study was to investigate the temporal relationship between changes in biofilm composition and enamel demineralization following exposure to sucrose. A crossover blind study was conducted in situ in three phases, during which 12 volunteers, divided into three groups, subjected enamel slabs 8 times/day to water (negative control), 10% glucose + 10% fructose (active control) or 20% sucrose solution. Biofilms accumulated for 3, 7 and 14 days were collected and analyzed biochemically and microbiologically, and mineral loss from enamel (deltaZ) was evaluated. Significantly higher deltaZ was found in the sucrose group after 7 days. However, on the 3rd day, lactobacilli, insoluble extracellular polysaccharide (EPS) and intracellular polysaccharide were significantly higher, and the calcium, inorganic phosphorus and fluoride concentrations in the biofilm were significantly lower in the sucrose group than in the negative controls. The only significant difference compared to glucose + fructose treatment was a higher insoluble EPS concentration. The data suggest that, although sucrose induces significant enamel demineralization only after 7 days of biofilm accumulation, changes in the biofilm composition are observed earlier. 2007 S. Karger AG, Basel

  20. Effect of sucrose containing iron (II) on dental biofilm and enamel demineralization in situ.

    Science.gov (United States)

    Pecharki, G D; Cury, J A; Paes Leme, A F; Tabchoury, C P M; Del Bel Cury, A A; Rosalen, P L; Bowen, W H

    2005-01-01

    Since the effect of iron (Fe) on the cariogenicity of sucrose in humans is unexplored, this study assessed in situ the effect of Fe co-crystallized with sucrose (Fe-sucrose) topically applied in vitro on the acidogenicity, biochemical and microbiological composition of the dental biofilm formed in vivo and on the demineralization of the enamel. During two phases of 14 days each, 16 volunteers wore palatal appliances containing blocks of human enamel, which were submitted to four groups of separate treatments: (1) water; (2) 20% sucrose; (3) 20% (w/v) sucrose plus 18 microg Fe/ml, and (4) 20% (w/v) sucrose plus 70 microg Fe/ml. The solutions were dripped onto the blocks 8 times per day. The biofilms formed on the blocks were analyzed with respect to acidogenicity, biochemical and microbiological composition. Mineral loss was determined on enamel by surface and cross-sectional microhardness. Lower demineralization was found in the blocks subjected to Fe-sucrose (70 microg Fe/ml) than in those treated with sucrose (p < 0.05). This concentration of Fe also reduced significantly the populations of mutans streptococci in the biofilm formed on the blocks. In conclusion, our data suggest that Fe may reduce in situ the cariogenic potential of sucrose and the effect seems to be related to the reduction in the populations of mutans streptococci in the dental biofilm formed. Copyright (c) 2005 S. Karger AG, Basel.

  1. Monitoring tooth demineralization using a cross polarization optical coherence tomographic system with an integrated MEMS scanner

    Science.gov (United States)

    Fried, Daniel; Staninec, Michal; Darling, Cynthia; Kang, Hobin; Chan, Kenneth

    2012-01-01

    New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we present early results using a new cross-polarization OCT system introduced by Santec. This system utilizes a swept laser source and a MEMS scanner for rapid acquisition of cross polarization images. Preliminary studies show that this system is useful for measurement of the severity of demineralization on tooth surfaces and for showing the spread of occlusal lesions under the dentinal-enamel junction.

  2. Selective removal of demineralization using near infrared cross polarization reflectance and a carbon dioxide laser

    Science.gov (United States)

    Chan, Kenneth H.; Fried, Daniel

    2012-01-01

    Lasers can ablate/remove tissue in a non-contact mode of operation and a pulsed laser beam does not interfere with the ability to image the tooth surface, therefore lasers are ideally suited for integration with imaging devices for image-guided ablation. Laser energy can be rapidly and efficiently delivered to tooth surfaces using a digitally controlled laser beam scanning system for precise and selective laser ablation with minimal loss of healthy tissues. Under the appropriate irradiation conditions such laser energy can induce beneficial chemical and morphological changes in the walls of the drilled cavity that can increase resistance to further dental decay and produce surfaces with enhanced adhesive properties to restorative materials. Previous studies have shown that images acquired using near-IR transillumination, optical coherence tomography and fluorescence can be used to guide the laser for selective removal of demineralized enamel. Recent studies have shown that NIR reflectance measurements at 1470-nm can be used to obtain images of enamel demineralization with very high contrast. The purpose of this study was to demonstrate that image guided ablation of occlusal lesions can be successfully carried out using a NIR reflectance imaging system coupled with a carbon dioxide laser operating at 9.3-μm with high pulse repetition rates.

  3. Synergistic effect of fluoride and laser irradiation for the inhibition of the demineralization of dental enamel

    Science.gov (United States)

    Lee, Raymond; Chan, Kenneth H.; Jew, Jamison; Simon, Jacob C.; Fried, Daniel

    2017-02-01

    Both laser irradiation and fluoride treatment alone are known to provide increased resistance to acid dissolution. CO2 lasers tuned to a wavelength of 9.3 μm can be used to efficiently convert the carbonated hydroxyapatite of enamel to a much more acid resistant purer phase hydroxyapatite (HAP). Further studies have shown that fluoride application to HAP yields fluoroapatite (FAP) which is even more resistant against acid dissolution. Previous studies show that CO2 lasers and fluoride treatments interact synergistically to provide significantly higher protection than either method alone, but the mechanism of interaction has not been elucidated. We recently observed the formation of microcracks or a "crazed" zone in the irradiated region that is resistant to demineralization using high-resolution microscopy. The microcracks are formed due to the slight contraction of enamel due to transformation of carbonated hydroxyapatite to the more acid resistant pure phase hydroxyapatite (HAP) that has a smaller lattice. In this study, we test the hypothesis that these small cracks will provide greater adhesion for topical fluoride for greater protection against acid demineralization.

  4. Remineralization of demineralized bone matrix (DBM) via alternating solution immersion (ASI).

    Science.gov (United States)

    Soicher, Matthew A; Christiansen, Blaine A; Stover, Susan M; Leach, J Kent; Fyhrie, David P

    2013-10-01

    In order to achieve successful clinical outcomes, biomaterials used for bone grafts must possess a number of traits including biocompatibility and osteoconductivity. These materials must also demonstrate appropriate mechanical stability to withstand handling as well as support potentially significant stresses at the implant site. Synthetic and natural polymer scaffolds used for bone tissue engineering (BTE) often lack necessary mechanical properties. Our goal was to internally mineralize natural collagenous matrix, thereby increasing mechanical properties of the material to useful levels. Published methods for intrafibrillar collagen mineralization were applied to clinically relevant-sized constructs but did not successfully deposit mineral in the interior of the constructs. To address this limitation, we developed a new technique for the remineralization of demineralized bone matrix (DBM) based on alternating solution immersion, or ASI. Mineral was removed from equine bone specimens, leaving behind a demineralized bone matrix (DBM). This matrix provides a framework for the nucleation and growth of a replacement mineral phase. Plain film radiography and microcomputed tomography (microCT) indicated accumulation of mineral within the DBM, and mechanical testing (3 point bending and compression) revealed a significant increase in stiffness between the DBM and the remineralized bone matrix (RBM). We believe this remineralization process will be useful in the preparation of stiff and strong allografts for clinical application. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Selective Removal of Demineralization Using Near Infrared Cross Polarization Reflectance and a Carbon Dioxide Laser.

    Science.gov (United States)

    Chan, Kenneth H; Fried, Daniel

    2012-02-09

    Lasers can ablate/remove tissue in a non-contact mode of operation and a pulsed laser beam does not interfere with the ability to image the tooth surface, therefore lasers are ideally suited for integration with imaging devices for image-guided ablation. Laser energy can be rapidly and efficiently delivered to tooth surfaces using a digitally controlled laser beam scanning system for precise and selective laser ablation with minimal loss of healthy tissues. Under the appropriate irradiation conditions such laser energy can induce beneficial chemical and morphological changes in the walls of the drilled cavity that can increase resistance to further dental decay and produce surfaces with enhanced adhesive properties to restorative materials. Previous studies have shown that images acquired using near-IR transillumination, optical coherence tomography and fluorescence can be used to guide the laser for selective removal of demineralized enamel. Recent studies have shown that NIR reflectance measurements at 1470-nm can be used to obtain images of enamel demineralization with very high contrast. The purpose of this study was to demonstrate that image guided ablation of occlusal lesions can be successfully carried out using a NIR reflectance imaging system coupled with a carbon dioxide laser operating at 9.3-μm with high pulse repetition rates.

  6. Gamma-ray irradiation, autoclave and ethylene oxide sterilization to thermosetting polyurethane: Sterilization to polyurethane

    Science.gov (United States)

    Hirata, Noriko; Matsumoto, Ken-Ichi; Inishita, Takashi; Takenaka, Yoshinori; Suma, Yasunori; Shintani, Hideharu

    1995-09-01

    Thermosetting polyurethane (PU) is widely used in a large variety of medical devices. 4,4'-methylenedianiline (MDA) was produced from PU by sterilization and it was studied for the relationship between urethane components or polymer characteristics and formation of MDA upon sterilization, using the commercially available dialyzers fabricated with different combination of isocyanate and polyol. We confirmed that the molecular-weight of polyol influenced the production of MDA upon sterilization.

  7. Safety and efficacy of hysteroscopic sterilization compared with laparoscopic sterilization: an observational cohort study.

    Science.gov (United States)

    Mao, Jialin; Pfeifer, Samantha; Schlegel, Peter; Sedrakyan, Art

    2015-10-13

    To compare the safety and efficacy of hysteroscopic sterilization with the "Essure" device with laparoscopic sterilization in a large, all-inclusive, state cohort. Population based cohort study. Outpatient interventional setting in New York State. Women undergoing interval sterilization procedure, including hysteroscopic sterilization with Essure device and laparoscopic surgery, between 2005 and 2013. Safety events within 30 days of procedures; unintended pregnancies and reoperations within one year of procedures. Mixed model accounting for hospital clustering was used to compare 30 day and 1 year outcomes, adjusting for patient characteristics and other confounders. Time to reoperation was evaluated using frailty model for time to event analysis. We identified 8048 patients undergoing hysteroscopic sterilization and 44,278 undergoing laparoscopic sterilization between 2005 and 2013 in New York State. There was a significant increase in the use of hysteroscopic procedures during this period, while use of laparoscopic sterilization decreased. Patients undergoing hysteroscopic sterilization were older than those undergoing laparoscopic sterilization and were more likely to have a history of pelvic inflammatory disease (10.3% v 7.2%, Psterilization was not associated with a higher risk of unintended pregnancy (odds ratio 0.84 (95% CI 0.63 to 1.12)) but was associated with a substantially increased risk of reoperation (odds ratio 10.16 (7.47 to 13.81)) compared with laparoscopic sterilization. Patients undergoing hysteroscopic sterilization have a similar risk of unintended pregnancy but a more than 10-fold higher risk of undergoing reoperation compared with patients undergoing laparoscopic sterilization. Benefits and risks of both procedures should be discussed with patients for informed decisions making. © Mao et al 2015.

  8. Evaluation removes obstacles to sterilization in Brazil.

    Science.gov (United States)

    1985-01-01

    In 1978, Centro de Pesquisas de Assitencia Integrada a Mulher e a Crianca (CPAIMC) in Rio de Janeiro began to offer interval sterilizations in an attempt to increase the access of poor women to sterilization services. By the end of 1984, the program had provided in excess of 19,000 sterilizations, making CPAIMC Brazil's largest single source of voluntary interval sterilization. Despite the program's success, CPAIMC was concerned that obstacles still existed in the poor woman's path to sterilization access. A study was conducted by Family Health International (FHI) in collaboration with the Pathfinder Fund and CPAIMC's Department of Information, Evaluation and Research to locate possible barriers. The study indicated that less than half of the women who requested sterilization between June 1 and August 31, 1983 actually had the procedure. During that period, 1256 women requested sterilization at the CPAIMC clinic. Of these, 925 were approved, and 639 were scheduled for surgery. Only 559 were actually sterilized within 3 months of receiving approval. 1 possible reason why women were not receiving the surgery was that the women requesting sterilization actually were not highly motivated to obtain the service. Yet, study results indicate this probably was not the reason. During initial interviews at the clinic, many women said they had thought very carefully about being sterilized, and more than 40% reported deciding to have a tubal ligation before their last pregnancy. Almost 3/4 of the women reported that they did not plan their last pregnancy, and almost 2/3 indicated that the pregnancy was unwanted. About 63% were contracepting, and many were using effective methods. More than half of the non-contraceptors were not using a method because they had just ended a pregnancy and were not sexually active. As a group, the women requesting sterilization were highly motivated to avoid having more children. Age and number of children were the most important criteria used by

  9. Searching for Sterile Neutrinos with MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Timmons, Ashley [Manchester U.

    2016-01-01

    This document presents the latest results for a 3+1 sterile neutrino search using the $10.56 \\times 10^{20}$ protons-on-target data set taken from 2005 - 2012. By searching for oscillations driven by a large mass splitting, MINOS is sensitive to the existence of sterile neutrinos through any energy dependent deviations using a charged current sample, as well as looking at any relative deficit between neutral current events between the far and near detectors. This document will discuss the novel analysis that enabled a search for sterile neutrinos setting a limit in the previously unexplored regions in the parameter space $\\{\\Delta m^{2}_{41}, \\sin^2\\theta_{24}\\}$. The results presented can be compared to the parameter space suggested by LSND and MiniBooNE and complements other previous experimental searches for sterile neutrinos in the electron neutrino appearance channel.

  10. Male sterility and fertility restoration in crops.

    Science.gov (United States)

    Chen, Letian; Liu, Yao-Guang

    2014-01-01

    In plants, male sterility can be caused either by mitochondrial genes with coupled nuclear genes or by nuclear genes alone; the resulting conditions are known as cytoplasmic male sterility (CMS) and genic male sterility (GMS), respectively. CMS and GMS facilitate hybrid seed production for many crops and thus allow breeders to harness yield gains associated with hybrid vigor (heterosis). In CMS, layers of interaction between mitochondrial and nuclear genes control its male specificity, occurrence, and restoration of fertility. Environment-sensitive GMS (EGMS) mutants may involve epigenetic control by noncoding RNAs and can revert to fertility under different growth conditions, making them useful breeding materials in the hybrid seed industry. Here, we review recent research on CMS and EGMS systems in crops, summarize general models of male sterility and fertility restoration, and discuss the evolutionary significance of these reproductive systems.

  11. Assessment of differences between X and gamma rays in order to validate a new generation of irradiators for insect sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, Thiago; Walder, Julio M.M., E-mail: piaui@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Parker, Andrew G.; Jessup, Andrew; Orozco-Davila, Dina; Islam, Amirul; Dammalage, Thilakasiri, E-mail: A.Jessup@iaea.or [Joint FAO/IAEA-UN A-2444, Seibersdorf (Austria). Insect Pest Control Subprogramme; Pereira, Rui, E-mail: R.Cardoso-Pereira@iaea.or [Joint FAO/IAEA-UN, Vienna (Austria). Insect Pest Control Subprogramme

    2009-07-01

    Recent fears of terrorism provoked an increase in delays and denials of transboundary shipments of radioisotopes. This represents a serious constraint to sterile insect technique (SIT) programs around the world as they rely on the use of ionizing energy from radioisotopes for insect sterilization. In order to validate a novel Xray irradiator, a series of studies on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) were carried out, comparing the relative biological effectiveness (RBE) between X-rays and traditional gamma radiation from {sup 60}Co. Male C. capitata pupae and pupae of both sexes of A. fraterculus, both 24 to 48 h before adult emergence, were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Estimated mean doses of 91.2 Gy of X and 124.9 Gy of gamma radiation induced 99% sterility in C. capitata males. Irradiated A. fraterculus were 99% sterile at about 40-60 Gy for both radiation treatments. Standard quality control parameters were not significantly affected by the two types of radiation. There were no significant differences between X and gamma radiation regarding mating indices. The RBE did not differ significantly between the tested X and gamma radiation, and X-rays are as biologically effective for SIT purposes as gamma rays are. This work confirms the suitability of this new generation of X-ray irradiators for pest control programs in UN Member States. (author)

  12. 21 CFR 872.6730 - Endodontic dry heat sterilizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endodontic dry heat sterilizer. 872.6730 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6730 Endodontic dry heat sterilizer. (a) Identification. An endodontic dry heat sterilizer is a device intended to sterilize endodontic...

  13. 21 CFR 880.2800 - Sterilization process indicator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sterilization process indicator. 880.2800 Section... Monitoring Devices § 880.2800 Sterilization process indicator. (a) Biological sterilization process indicator—(1) Identification. A biological sterilization process indicator is a device intended for use by a...

  14. 21 CFR 610.12 - Sterility.

    Science.gov (United States)

    2010-04-01

    ...) 0.5 gm. Resazurin (0.10% solution, 1.0 ml. freshly prepared) pH after sterilization 7.1±0.2. (ii... Phosphate 2.5 gm. Dextrose (C6H12O6·H2O) 2.5 gm. Purified water 1,000.0 ml. pH after sterilization 7.3±0.2..., characteristics, identity, and verification. Two or more strains of microorganisms that are exacting in their...

  15. Ethylene Oxide Gas Sterilization of Medical Devices.

    Science.gov (United States)

    Shintani, Hideharu

    2017-01-01

     Ethylene oxide gas is an agent in the sterilization of medical devices due to its effectiveness and compatibility with most materials. The advantages and disadvantages, as well as its recommended uses, are explored in this review article. The variables and their relevance on process optimization are described, the types of processing cycles are detailed and emphasis is given to the design and validation of the sterilization process.

  16. Health technology assessment: Off-site sterilization

    OpenAIRE

    Dehnavieh, Reza; Mirshekari, Nadia; Ghasemi, Sara; Goudarzi, Reza; Haghdoost, AliAkbar; Mehrolhassani, Mohammad Hossain; Moshkani, Zahra; Noori Hekmat, Somayeh

    2016-01-01

    Background: Every year millions of dollars are expended to equip and maintain the hospital sterilization centers, and our country is not an exception of this matter. According to this, it is important to use more effective technologies and methods in health system in order to reach more effectiveness and saving in costs. This study was conducted with the aim of evaluating the technology of regional sterilization centers. Methods: This study was done in four steps. At the first step, safety an...

  17. Distance learning on surgical material sterilization processes

    OpenAIRE

    Quelhas, MCF; Lopes, MHBD; Ropoli, EA

    2008-01-01

    This study had the following goals: describing the development of a distance learning (DL) course on Surgical Material Sterilization Processes, to be given over the Internet; having the course evaluated by specialists in sterilization processes and in DL; describing students' and evaluators' profiles, and to evaluate the students' participation and their opinions about the course. The chosen course environment was TelEduc, and the teaching method was Case-Based Learning. The target population...

  18. Preliminary thermoluminescence and optically stimulated luminescence investigation of commercial pharmaceutical preparations towards the drug sterilization dosimetry.

    Science.gov (United States)

    Kazakis, Nikolaos A; Tsirliganis, Nestor C; Kitis, George

    2014-09-01

    Drug sterilization with ionizing radiation is a well-established technology and is gaining ground the last decades due to its numerous advantages. Identification of irradiated drugs would be interesting and, in this respect, the present work aims, for the first time to the authors' best knowledge, to explore whether OSL and TL can be employed as methods for post-sterilization dosimetry on commercial drugs, i.e., as tools for the detection of irradiated drugs. Five widely used drugs, i.e., Daktarin(®), Aspirin(®), Panadol(®), Brufen(®) and Procef(®), are used for this purpose. Preliminary findings are very promising towards the post-sterilization dosimetry and the use of commercial drugs for normal and/or accidental dosimetry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Sterilization of hydrogen peroxide resistant bacterial spores with stabilized chlorine dioxide.

    Science.gov (United States)

    Friedline, Anthony; Zachariah, Malcolm; Middaugh, Amy; Heiser, Matt; Khanna, Neeraj; Vaishampayan, Parag; Rice, Charles V

    2015-01-01

    Bacillus pumilus SAFR-032 spores isolated from a clean room environment are known to exhibit enhanced resistance to peroxide, desiccation, UV radiation and chemical disinfection than other spore-forming bacteria. The survival of B. pumilus SAFR-032 spores to standard clean room sterilization practices requires development of more stringent disinfection agents. Here, we report the effects of a stabilized chlorine dioxide-based biocidal agent against spores of B. pumilus SAFR-032 and Bacillus subtilis ATCC 6051. Viability was determined via CFU measurement after exposure. Chlorine dioxide demonstrated efficacy towards sterilization of spores of B. pumilus SAFR-032 equivalent or better than exposure to hydrogen peroxide. These results indicate efficacy of chlorine dioxide delivered through a stabilized chlorine dioxide product as a means of sterilization of peroxide- and UV-resistant spores.

  20. New sterilization technology and the effects on bone pencil.

    Science.gov (United States)

    Van Meeteren, Justin; Lehman, James A; Zins, James; Brown, Wendy; Burgoyne, Deborah

    2012-03-01

    The changing technology today with sterilizing surgical tools has called into question the ability to adequately sterilize the bone pencil. Concern has arisen as to the sterilization of bone pencil and whether the new technology used in sterilizing the operating equipment meets the standards set by the Centers for Disease Control and Prevention. This study was performed to compare the older gas sterilizing technology (ETO) with the newer hydrogen peroxide-based Sterrad sterilizer. An equal number of standard number 2 pencils were used for both methods of sterilization. Three separate batches were used for a total of 13 pencils in each group. All pencils were cultured at 24 and 48 hours after sterilization. All culture plates showed no growth during the incubation process. Bone pencil can be sterilized using the new gas sterilization equipment as well as the older equipment.

  1. Voluntary sterilization in Serbia: Unmet need?

    Directory of Open Access Journals (Sweden)

    Rašević Mirjana M.

    2002-01-01

    Full Text Available Is voluntary sterilization as a birth control method accepted in Serbia? This is certainly a question that is being imposed for research, regardless of the fact that voluntary sterilization is neither accessible nor promoted. Most importantly because there is no understanding in the social nor political sphere for legalization of voluntary sterilization as a form of birth control, apart from the clear necessity for this, first, step. They are: the recognition that voluntary sterilization is an efficient and safe birth control method, respectability of basic human as well as sexual and reproductive rights, spreading of sterilization as a form of birth control among population of both developed and developing countries and an epidemic diffusion of repeated induced abortions in Serbia. Thus individual recognition of the advantages of relying on voluntary sterilization, in a non-encouraging atmosphere, certainly represents one more argument to enable couples to prevent conception by sterilization. Since it was impossible to carry out a representative research among the population of men and women who are at risk for conception, an attempt was made to obtain a reply to the set question among women who decided to induce abortion. It was done out of at least two reasons. The first being that women with induced abortion in their reproductive history were the target group for voluntary sterilization. The second reason was based on the assumption that bringing a decision on induced abortion is preceded by the reconsideration of an earlier adopted strategy regarding children, giving birth and contraception and thus its rational component is revealed more and therefore more easily measurable. The research was carried out in the University Clinic of Obstetrics and Gynecology 'Narodni front' in Belgrade from January 21st o March 1st 2002, and included 296 women. By comparing the social and demographic characteristics of the female respondents, as well as

  2. Effect of gamma, ethylene oxide, electron beam, and plasma sterilization on the behaviour of SR-PLLA fibres in vitro.

    Science.gov (United States)

    Nuutinen, Juha-Pekka; Clerc, Claude; Virta, Tuija; Törmälä, Pertti

    2002-01-01

    The aim of this study was to evaluate the effect of various sterilization processes on the physical and mechanical properties of self-reinforced bioabsorbable fibres made out of polylactide (PLLA). The samples were sterilized using plasma, ethylene oxide (one and two cycles), gamma (25 kGy at room temperature, 25 kGy in dry ice, and 2 x 25 kGy at room temperature), and electron beam (15, 25, and 55 kGy) sterilization. The intrinsic viscosity, crystallinity, and mechanical properties (modulus of elasticity, yield strength, and ultimate tensile strength) were tested before and immediately after each sterilization treatment, as well as up to 30 weeks in vitro. Compared with unsterilized fibres, the intrinsic viscosity was markedly decreased after radiation sterilization (gamma and electron beam) and the loss in mechanical properties was accelerated during in vitro degradation. Plasma and ethylene oxide (one and two cycles) did not markedly alter the properties of the samples after sterilization or during in vitro degradation. These data are important for determining the effect of various sterilization processes on the physical and mechanical properties of polylactide-based materials and can be used to predict how fast degradation of the mechanical properties of the self-reinforced PLLA will occur. They can also be used to tailor the degradation kinetics to optimize implant design.

  3. Probability of pregnancy after sterilization: a comparison of hysteroscopic versus laparoscopic sterilization.

    Science.gov (United States)

    Gariepy, Aileen M; Creinin, Mitchell D; Smith, Kenneth J; Xu, Xiao

    2014-08-01

    To compare the expected probability of pregnancy after hysteroscopic versus laparoscopic sterilization based on available data using decision analysis. We developed an evidence-based Markov model to estimate the probability of pregnancy over 10 years after three different female sterilization procedures: hysteroscopic, laparoscopic silicone rubber band application and laparoscopic bipolar coagulation. Parameter estimates for procedure success, probability of completing follow-up testing and risk of pregnancy after different sterilization procedures were obtained from published sources. In the base case analysis at all points in time after the sterilization procedure, the initial and cumulative risk of pregnancy after sterilization is higher in women opting for hysteroscopic than either laparoscopic band or bipolar sterilization. The expected pregnancy rates per 1000 women at 1 year are 57, 7 and 3 for hysteroscopic sterilization, laparoscopic silicone rubber band application and laparoscopic bipolar coagulation, respectively. At 10 years, the cumulative pregnancy rates per 1000 women are 96, 24 and 30, respectively. Sensitivity analyses suggest that the three procedures would have an equivalent pregnancy risk of approximately 80 per 1000 women at 10 years if the probability of successful laparoscopic (band or bipolar) sterilization drops below 90% and successful coil placement on first hysteroscopic attempt increases to 98% or if the probability of undergoing a hysterosalpingogram increases to 100%. Based on available data, the expected population risk of pregnancy is higher after hysteroscopic than laparoscopic sterilization. Consistent with existing contraceptive classification, future characterization of hysteroscopic sterilization should distinguish "perfect" and "typical" use failure rates. Pregnancy probability at 1 year and over 10 years is expected to be higher in women having hysteroscopic as compared to laparoscopic sterilization. Copyright © 2014

  4. Preservation of imaging capability in sensitive ultrasound contrast agents after indirect plasma sterilization.

    Science.gov (United States)

    Albala, Lorenzo; Ercan, Utku K; Joshi, Suresh G; Eisenbrey, John R; Teraphongphom, Nutte; Wheatley, Margaret A

    2015-10-15

    Many injectables are not amenable to standard sterilization methods, which destroy sensitive materials. This is particularly true for ultrasound contrast agents (UCA) consisting of gas bubbles stabilized by a surfactant or polymer shell. We investigated a new method to achieve safe and effective sterilization in production by introducing dielectric-barrier discharge non-thermal plasma. A dielectric-barrier discharge was generated to first produce plasma-treated phosphate-buffered saline (PTPBS), which was used as a sterilant solution for our UCA SE61, avoiding direct heat, pressure, chemicals, or radiation. Treated samples were tested for acoustic properties in vitro and in a flow phantom, and for sterility by standard methods. Three minutes plasma treatment of phosphate-buffered saline (PBS) proved effective. The samples showed significant inactivation of inoculated bacteria upon PTPBS treatment as compared to un-treated-PBS (p=0.0022). The treated and untreated samples showed no statistical significance (p>0.05) in acoustic response or bubble diameter (mean±SEM: 2.52±0.31 μm). Nile Red was used to model intercalation of drug in the hydrophobic shell, intercalated successfully into SE61, and was unaffected by plasma treatment. The PTPBS completely sterilized suspensions of UCA, and it did not compromise the acoustic properties of the agent or its ability to retain a hydrophobic compound. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Thermal Evolution of the Primordial Clouds in Warm Dark Matter Models with keV Sterile Neutrinos

    Science.gov (United States)

    Stasielak, Jaroslaw; Biermann, Peter L.; Kusenko, Alexander

    2007-01-01

    We analyze the processes relevant for star formation in a model with dark matter in the form of sterile neutrinos. Sterile neutrino decays produce an X-ray background radiation that has a twofold effect on the collapsing clouds of hydrogen. First, the X-rays ionize the gas and cause an increase in the fraction of molecular hydrogen, which makes it easier for the gas to cool and to form stars. Second, the same X-rays deposit a certain amount of heat, which could, in principle, thwart the cooling of gas. We find that in all the cases we have examined the overall effect of sterile dark matter is to facilitate the cooling of gas. Hence, we conclude that dark matter in the form of sterile neutrinos can help the early collapse of gas clouds and the subsequent star formation.

  6. Demineralized bone matrix and human cancellous bone enhance fixation of porous-coated titanium implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2016-01-01

    Allogenic bone graft has been considered the gold standard in connection with bone graft material in revision joint arthroplasty. However, the lack of osteogenic potential and the risk of disease transmission are clinical challenges. The use of osteoinductive materials, such as demineralized bone...

  7. Effect of milk and soy-based infant formulas on in situ demineralization of human primary enamel.

    Science.gov (United States)

    de Mazer Papa, Anna Maria Cia; Tabchoury, Cínthia Pereira Machado; Del Bel Cury, Altair Antoninha; Tenuta, Livia Maria Andaló; Arthur, Rodrigo Alex; Cury, Jaime Aparecido

    2010-01-01

    The effect of infant formulas sweetened or not with sucrose on primary enamel demineralization and dental biofilm is not known. This study's purpose was to evaluate the effect of infant formula and sucrose association on demineralization of primary enamel and dental biofilm formed. A cross-over, split-mouth, and blind in situ study was conducted during 3 phases, each of 10 days duration, during which 11 volunteers wore palatal appliances containing slabs of human primary enamel. The dental slabs were extraorally subjected 8 times a day to 6 groups of treatment: distilled and deionized water; 10% sucrose solution; and milk-based and soy-based formula with or without 10% sucrose added. After each phase, the acidogenicity, biochemical and microbiological composition of dental biofilm formed was analyzed, and enamel demineralization was assessed by microhardness. Both formulas induced significant enamel mineral loss, which increased when sucrose was added. Both formulas were fermented, resulting in a decrease of biofilm pH, irrespective of sucrose addition. Also, lactobacilli counts were higher in biofilm formed in the presence of both formulas when compared to the water group. Milk and soy-based formulas present potential to induce demineralization in primary enamel, which increased when sweetened with sucrose.

  8. Selective removal of demineralized enamel using a CO2 laser coupled with near-IR reflectance imaging

    Science.gov (United States)

    Tom, Henry; Chan, Kenneth H.; Saltiel, Daniel; Fried, Daniel

    2015-02-01

    Detection and diagnosis of early dental caries lesions can be difficult due to variable tooth coloration, staining of the teeth and poor contrast between sound and demineralized enamel. These problems can be overcome by using near-infrared (NIR) imaging. Previous studies have demonstrated that lasers can be integrated with NIR imaging devices, allowing image-guided ablation. The aim of this study was to demonstrate that NIR light at 1500 - 1700 nm can be used to guide a 9.3-μm CO2 laser for the selective ablation of early demineralization on tooth occlusal surfaces. The occlusal surfaces of ten sound human molars were used in this in-vitro study. Shallow simulated caries lesions of varying depth and position were produced on tooth occlusal surfaces using a demineralization solution. Sequential NIR reflectance images at 1500 - 1700 nm were used to guide the laser for selective ablation of the lesion areas. Digital microscopy and polarization sensitive optical coherence tomography (PS-OCT) were used to assess the selectivity of removal. This study demonstrates that high contrast NIR reflectance images can be used for the image-guided laser ablation of early demineralization from tooth occlusal surfaces.

  9. Does ozone enhance the remineralizing potential of nanohydroxyapatite on artificially demineralized enamel? A laser induced fluorescence study

    Science.gov (United States)

    Srinivasan, Samuelraj; Prabhu, Vijendra; Chandra, Subhash; Koshy, Shalini; Acharya, Shashidhar; Mahato, Krishna K.

    2014-02-01

    The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (Plaser induced fluorescence was found to be effective in assessing the surface mineral changes in enamel. Ozone can be considered an effective agent in reversing the initial enamel caries there by preventing the tooth from entering into the repetitive restorative cycle.

  10. The efficacy of laser-assisted in-office bleaching and home bleaching on sound and demineralized enamel.

    Science.gov (United States)

    Ahrari, Farzaneh; Akbari, Majid; Mohammadpour, Sakineh; Forghani, Maryam

    2015-12-30

    This study investigated the effectiveness of laser-assisted in-office bleaching and home-bleaching in sound and demineralized enamel. The sample consisted of 120 freshly-extracted bovine incisors. Half of the specimens were stored in a demineralizing solution to induce white spot lesions. Following exposure to a tea solution for 7.5 days, the specimens were randomly assigned to 4 groups of 30 according to the type of enamel and the bleaching procedure employed. Groups 1 and 2 consisted of demineralized teeth subjected to in-office bleaching and home bleaching, whereas in groups 3 and 4, sound teeth were subjected to in-office and home bleaching, respectively. A diode laser (810 nm, 2 W, continuous wave, four times for 15 seconds each) was employed for assisting the in-office process. The color of the specimens was measured before (T1) and after (T2) staining and during (T3) and after (T4) the bleaching procedures using a spectrophotometer. The color change (ΔE) between different treatments stages was compared among the groups. There were significant differences in the color change between T2 and T3 (ΔE T2-T3) and T2 and T4 (ΔE T2-T4) stages among the study groups (poffice bleaching (group 1) as compared to the other groups (Poffice bleaching could provide faster and greater whitening effect than home bleaching on stained demineralized enamel, but both procedures produced comparable results on sound teeth.

  11. The effect of the radio-protective agents ethanol, trimethylglycine, and beer on survival of X-ray-sterilized male Aedes aegypti.

    Science.gov (United States)

    Rodriguez, Stacy D; Brar, Ramaninder K; Drake, Lisa L; Drumm, Hannah E; Price, David P; Hammond, John I; Urquidi, Jacob; Hansen, Immo A

    2013-07-18

    Sterile Insect Technique (SIT) has been successfully implemented to control, and in some cases, eradicate, dipteran insect populations. SIT has great potential as a mosquito control method. Different sterilization methods have been used on mosquitoes ranging from chemosterilization to genetically modified sterile male mosquito strains; however, sterilization with ionizing radiation is the method of choice for effective sterilization of male insects for most species. The lack of gentle radiation methods has resulted in significant complications when SIT has been applied to mosquitoes. Several studies report that irradiating mosquitoes resulted in a decrease in longevity and mating success compared to unirradiated males. The present study explored new protocols for mosquito sterilization with ionizing radiation that minimized detrimental effects on the longevity of irradiated males. We tested three compounds that have been shown to act as radioprotectors in the mouse model system - ethanol, trimethylglycine, and beer. Male Aedes aegypti were treated with one of three chosen potential radioprotectors and were subsequently irradiated with identical doses of long-wavelength X-rays. We evaluated the effect of these radioprotectors on the longevity of male mosquito after irradiation. We found that X-ray irradiation with an absorbed dose of 1.17 gy confers complete sterility. Irradiation with this dose significantly shortened the lifespan of male mosquitoes and all three radioprotectors tested significantly enhanced the lifespan of irradiated mosquito males. Our results suggest that treatment with ethanol, beer, or trimethylglycine before irradiation can be used to enhance longevity in mosquitoes.

  12. The effect of the radio-protective agents ethanol, trimethylglycine, and beer on survival of X-ray-sterilized male Aedes aegypti

    Science.gov (United States)

    2013-01-01

    Background Sterile Insect Technique (SIT) has been successfully implemented to control, and in some cases, eradicate, dipteran insect populations. SIT has great potential as a mosquito control method. Different sterilization methods have been used on mosquitoes ranging from chemosterilization to genetically modified sterile male mosquito strains; however, sterilization with ionizing radiation is the method of choice for effective sterilization of male insects for most species. The lack of gentle radiation methods has resulted in significant complications when SIT has been applied to mosquitoes. Several studies report that irradiating mosquitoes resulted in a decrease in longevity and mating success compared to unirradiated males. The present study explored new protocols for mosquito sterilization with ionizing radiation that minimized detrimental effects on the longevity of irradiated males. Methods We tested three compounds that have been shown to act as radioprotectors in the mouse model system - ethanol, trimethylglycine, and beer. Male Aedes aegypti were treated with one of three chosen potential radioprotectors and were subsequently irradiated with identical doses of long-wavelength X-rays. We evaluated the effect of these radioprotectors on the longevity of male mosquito after irradiation. Results We found that X-ray irradiation with an absorbed dose of 1.17 gy confers complete sterility. Irradiation with this dose significantly shortened the lifespan of male mosquitoes and all three radioprotectors tested significantly enhanced the lifespan of irradiated mosquito males. Conclusion Our results suggest that treatment with ethanol, beer, or trimethylglycine before irradiation can be used to enhance longevity in mosquitoes. PMID:23866939

  13. How effectively do hydraulic calcium-silicate cements re-mineralize demineralized dentin.

    Science.gov (United States)

    Li, Xin; De Munck, Jan; Van Landuyt, Kirsten; Pedano, Mariano; Chen, Zhi; Van Meerbeek, Bart

    2017-04-01

    To characterize the chemical interplay and to quantify the re-mineralization potential of hydraulic calcium-silicate cements (hCSCs) at demineralized dentin. Pairs of class-I cavities were prepared in non-carious human third molars. One dentin cavity was demineralized with 10% formic acid (5h); the other served as control. The cavities were filled with two resin-free hCSCs (Biodentine, Septodont; ProRoot MTA, Dentsply Sirona) or one resin-based hCSC (TheraCal LC, Bisco). After 1-week, 1-, 3-, and 6-month storage in simulated body fluid (SBF), polished specimen cross-sections were chemically characterized using Field-emission-gun Electron Probe Micro-Analysis (Feg-EPMA) and micro-Raman spectroscopy (μRaman). Feg-EPMA line-scans and elemental mappings confirmed early re-mineralization induced by all three hCSCs at 1week. The relative depth and intensity of re-mineralization were for the resin-free hCSCs in the range of 50.5%-84.8% and 68.1%-89.2%, respectively. Re-mineralization did not significantly differ for the storage periods (p>0.05). Significantly less re-mineralization was achieved by the resin-based hCSC TheraCal LC that reached only at 6months a re-mineralization level that was no longer significantly different from that achieved by the resin-free hCSCs at 1week (p>0.05). Re-mineralization of intertubular dentin, including tubular occlusion, was observed; Si was occasionally detected to have infiltrated the dentin tubules. Dentin re-mineralization by hCSCs was confirmed using μRaman that revealed an increased phosphate peak at 960cm(-1). hCSCs do re-mineralize demineralized dentin. The resin-free cements induced re-mineralization at a higher speed/intensity than the resin-based hCSC. However, re-mineralization was incomplete for all hCSCs tested, this even at 6months. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  14. Evaluation of perforated demineralized dentin scaffold on bone regeneration in critical-size sheep iliac defects.

    Science.gov (United States)

    Kabir, Md Arafat; Murata, Masaru; Akazawa, Toshiyuki; Kusano, Kaoru; Yamada, Katsuhisa; Ito, Manabu

    2017-11-01

    Regenerating critical-size bone injury is a major problem that continues to inspire the design of new graft materials. Therefore, tissue engineering has become a novel approach for targeting bone regeneration applications. Human teeth are a rich source of stem cells, matrix, trace metal ions, and growth factors. A vital tooth-derived demineralized dentin matrix is acid-insoluble and composed of cross-linked collagen with growth factors. In this study, we recycled human non-functional tooth into a unique geometric dentin scaffold, entitled perforated root-demineralized dentin matrix (PR-DDM). The aim of this study was to evaluate the feasibility of PR-DDM as the scaffold for regenerating bone in critical-size iliac defects. Artificial macro-pores (1 mm in diameter) were added to human vital wisdom tooth after removing the enamel and pulp portions. The modified tooth was demineralized in 0.34 N HNO3 for 30 min and is referred to as PR-DDM scaffold. Critical-size defect (10 mm × 15 mm × 9 mm Ø) was created in the iliac crest of six adult sheep. The in vivo bone regeneration by the scaffold was evaluated by micro-CT, 3D micro-CT, and histological examination at 2 and 4 months post-implantation. PR-DDM exhibited better bone ingrowth, especially in the artificial macro-pores. The results of micro-CT and 3D micro-CT revealed good union between scaffold and native bone. New bone formation was observed in almost all portions of PR-DDM. Higher bone volume inside the scaffold was detected at 4 months compared with 2 months. New bone ingrowth was ankylosed with PR-DDM, and both osteoinduction and osteoconduction capability of PR-DDM were confirmed histologically. The ratio of new bone formation was higher at 4 months compared with 2 months by histomorphometric analysis. Altogether, these results demonstrated that the human tooth-derived graft material with a unique geometric structure, PR-DDM, contributed to active bone ingrowth in critical-size bone defects

  15. Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene

    OpenAIRE

    Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

    2016-01-01

    Nuclear male sterility is common in flowering plants, but its application in hybrid breeding and seed production is limited because of the inability to propagate a pure male sterile line for commercial hybrid seed production. Here, we characterized a rice nuclear gene essential for sporophytic male fertility and constructed a male sterility system that can propagate the pure male sterile seeds on a large scale. This system is fundamentally advantageous over the current cytoplasmic male steril...

  16. Experiences of coercion to sterilize and forced sterilization among women living with HIV in Latin America

    National Research Council Canada - National Science Library

    Kendall, Tamil; Albert, Claire

    2015-01-01

    ... have condemned coerced and forced sterilization as a violation of the right to health, bodily integrity, the right to freedom from violence, freedom from torture and inhuman and degrading treatment, freedom from discrimination, and women's right to decide the number and spacing of children [ 4 ]. Coercive and forced sterilization of women living with HIV (WLHIV...

  17. Sterilization Performance and Material Compatibility of Sterilizer for Dental Instruments using RF Oxygen Plasma

    Science.gov (United States)

    Sakai, Yasuhiro; Liu, Zhen; Hayashi, Nobuya; Goto, Masaaki

    2015-09-01

    The sterilization performance and material compatibility of low-pressure RF plasma sterilization method for dental instruments were investigated. RF electrode used in this experiment has been optimized for sterilization of dental instruments. The vial-type biological indicator (BI) simulating tiny space of dental instrument was used for evaluation of the sterilization performance. The pressure in the stainless chamber was fixed at 60 Pa. Sterilization of BI was achieved in shortest time 40 min at 80 W, and the sterilization effect was confirmed using three BIs. Light emission spectra of oxygen plasma indicated that production of atomic oxygen and excited oxygen molecule are maximum at pressure of 20 Pa and 200 Pa, respectively. Sterilization results of BIs indicated that successful rate increases with the oxygen pressure towards 200 Pa. Therefore, the excited oxygen molecule is deduced to be a major factor of the sterilization of BI. Surface morphology of dental instruments such as diamond bar was evaluated using scanning electron microscope (SEM). The deterioration of fine crystals of diamond bar has not observed after the plasma irradiation for 120 min with RF input power was 60W and pressure was 200 Pa.

  18. Phenology, sterility and inheritance of two environment genic male sterile (EGMS) lines for hybrid rice

    NARCIS (Netherlands)

    El-Namaky, R.; Oort, van P.A.J.

    2017-01-01

    Background: There is still limited quantitative understanding of how environmental factors affect sterility of Environment-conditioned genic male sterility (EGMS) lines. A model was developed for this purpose and tested based on experimental data from Ndiaye (Senegal) in 2013-2015. For the two

  19. Phenology, sterility and inheritance of two environment genic male sterile (EGMS) lines for hybrid rice.

    Science.gov (United States)

    El-Namaky, R; van Oort, P A J

    2017-12-01

    There is still limited quantitative understanding of how environmental factors affect sterility of Environment-conditioned genic male sterility (EGMS) lines. A model was developed for this purpose and tested based on experimental data from Ndiaye (Senegal) in 2013-2015. For the two EGMS lines tested here, it was not clear if one or more recessive gene(s) were causing male sterility. This was tested by studying sterility segregation of the F2 populations. Daylength (photoperiod) and minimum temperatures during the period from panicle initiation to flowering had significant effects on male sterility. Results clearly showed that only one recessive gene was involved in causing male sterility. The model was applied to determine the set of sowing dates of two different EGMS lines such that both would flower at the same time the pollen would be completely sterile. In the same time the local popular variety (Sahel 108, the male pollen donor) being sufficiently fertile to produce the hybrid seeds. The model was applied to investigate the viability of the two line breeding system in the same location with climate change (+2oC) and in two other potential locations: in M'Be in Ivory Coast and in the Nile delta in Egypt. Apart from giving new insights in the relation between environment and EGMS, this study shows that these insights can be used to assess safe sowing windows and assess the suitability of sterility and fertility period of different environments for a two line hybrid rice production system.

  20. Experiences of coercion to sterilize and forced sterilization among women living with HIV in Latin America

    Directory of Open Access Journals (Sweden)

    Tamil Kendall

    2015-03-01

    Full Text Available Introduction: Forced and coerced sterilization is an internationally recognized human rights violation reported by women living with HIV (WLHIV around the globe. Forced sterilization occurs when a person is sterilized without her knowledge or informed consent. Coerced sterilization occurs when misinformation, intimidation tactics, financial incentives or access to health services or employment are used to compel individuals to accept the procedure. Methods: Drawing on community-based research with 285 WLHIV from four Latin American countries (El Salvador, Honduras, Mexico and Nicaragua, we conduct thematic qualitative analysis of reports of how and when healthcare providers pressured women to sterilize and multivariate logistic regression to assess whether social and economic characteristics and fertility history were associated with pressure to sterilize. Results: A quarter (23% of the participant WLHIV experienced pressure to sterilize post-diagnosis. WLHIV who had a pregnancy during which they (and their healthcare providers knew their HIV diagnosis were almost six times more likely to experience coercive or forced sterilization than WLHIV who did not have a pregnancy with a known diagnosis (OR 5.66 CI 95% 2.35–13.58 p≤0.001. WLHIV reported that healthcare providers told them that living with HIV annulled their right to choose the number and spacing of their children and their contraceptive method, employed misinformation about the consequences of a subsequent pregnancy for women's and children's health, and denied medical services needed to prevent vertical (mother-to-child HIV transmission to coerce women into accepting sterilization. Forced sterilization was practiced during caesarean delivery. Conclusions: The experiences of WLHIV indicate that HIV-related stigma and discrimination by healthcare providers is a primary driver of coercive and forced sterilization. WLHIV are particularly vulnerable when seeking maternal health services

  1. Experiences of coercion to sterilize and forced sterilization among women living with HIV in Latin America.

    Science.gov (United States)

    Kendall, Tamil; Albert, Claire

    2015-01-01

    Forced and coerced sterilization is an internationally recognized human rights violation reported by women living with HIV (WLHIV) around the globe. Forced sterilization occurs when a person is sterilized without her knowledge or informed consent. Coerced sterilization occurs when misinformation, intimidation tactics, financial incentives or access to health services or employment are used to compel individuals to accept the procedure. Drawing on community-based research with 285 WLHIV from four Latin American countries (El Salvador, Honduras, Mexico and Nicaragua), we conduct thematic qualitative analysis of reports of how and when healthcare providers pressured women to sterilize and multivariate logistic regression to assess whether social and economic characteristics and fertility history were associated with pressure to sterilize. A quarter (23%) of the participant WLHIV experienced pressure to sterilize post-diagnosis. WLHIV who had a pregnancy during which they (and their healthcare providers) knew their HIV diagnosis were almost six times more likely to experience coercive or forced sterilization than WLHIV who did not have a pregnancy with a known diagnosis (OR 5.66 CI 95% 2.35-13.58 p≤0.001). WLHIV reported that healthcare providers told them that living with HIV annulled their right to choose the number and spacing of their children and their contraceptive method, employed misinformation about the consequences of a subsequent pregnancy for women's and children's health, and denied medical services needed to prevent vertical (mother-to-child) HIV transmission to coerce women into accepting sterilization. Forced sterilization was practiced during caesarean delivery. The experiences of WLHIV indicate that HIV-related stigma and discrimination by healthcare providers is a primary driver of coercive and forced sterilization. WLHIV are particularly vulnerable when seeking maternal health services. Health worker training on HIV and reproductive rights

  2. Effect of timing of administered calcium lactate on the sucrose-induced intraoral demineralization of bovine enamel.

    Science.gov (United States)

    Kashket, S; Yaskell, T

    1992-03-01

    A number of soluble calcium salts are known to reduce the demineralization of enamel in the mouth. The present study was undertaken to examine the effects of rinses containing different concentrations of calcium lactate, and the time of giving the rinses with respect to sucrose challenges. Subjects wore palatal appliances containing blocks of bovine enamel whose surfaces were covered with Streptococcus mutans IB 1600, and rinsed with 10% sucrose for 1 min. Changes in iodide penetrability of the enamel, and the pH and extracellular ion concentrations of the streptococcal plaque were determined. When added to the sucrose rinse, 100 or 150 mM calcium lactate reduced demineralization by about 35%, although the plaque pH was not affected. Plaque calcium was elevated but diffused away rapidly so that concentrations after 45 min were close to control values. Plaque inorganic phosphate and lactate were not affected. Ongoing demineralization appeared to be stopped when 100 mM calcium lactate was given 15 min after the sucrose rinse. When the lactate was given 15 min before the sucrose rinse, demineralization was reduced by only about 25%, consistent with the rapid diffusion of plaque calcium. The combination of (i) pretreatment with calcium lactate and (ii) admixture of calcium lactate with sucrose was most effective. Demineralization was reduced about 55% with 100 mM calcium lactate under these conditions, and protective effects were seen with as little as 25 mM. In summary, the findings demonstrate the enamel-protective effect of relatively low concentrations of calcium lactate, and point to the need to sustain a high plaque calcium during periods of maximum acidogenicity.

  3. Dynamic measurement of the optical properties of bovine enamel demineralization models using four-dimensional optical coherence tomography

    Science.gov (United States)

    Aden, Abdirahman; Anthony, Arthi; Brigi, Carel; Merchant, Muhammad Sabih; Siraj, Huda; Tomlins, Peter H.

    2017-07-01

    Dental enamel mineral loss is multifactorial and is consequently explored using a variety of in vitro models. Important factors include the presence of acidic pH and its specific ionic composition, which can both influence lesion characteristics. Optical coherence tomography (OCT) has been demonstrated as a promising tool for studying dental enamel demineralization. However, OCT-based characterization and comparison of demineralization model dynamics are challenging without a consistent experimental environment. Therefore, an automated four-dimensional OCT system was integrated with a multispecimen flow cell to measure and compare the optical properties of subsurface enamel demineralization in different models. This configuration was entirely automated, thus mitigating any need to disturb the specimens and ensuring spatial registration of OCT image volumes at multiple time points. Twelve bovine enamel disks were divided equally among three model groups. The model demineralization solutions were citric acid (pH 3.8), acetic acid (pH 4.0), and acetic acid with added calcium and phosphate (pH 4.4). Bovine specimens were exposed to the solution continuously for 48 h. Three-dimensional OCT data were obtained automatically from each specimen at a minimum of 1-h intervals from the same location within each specimen. Lesion dynamics were measured in terms of the depth below the surface to which the lesion extended and the attenuation coefficient. The net loss of surface enamel was also measured for comparison. Similarities between the dynamics of each model were observed, although there were also distinct characteristic differences. Notably, the attenuation coefficients showed a systematic offset and temporal shift with respect to the different models. Furthermore, the lesion depth curves displayed a discontinuous increase several hours after the initial acid challenge. This work demonstrated the capability of OCT to distinguish between different enamel demineralization

  4. The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix.

    Science.gov (United States)

    Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

    2016-03-01

    This study investigates the role of acetone, as a carrier for nano-hydroxyapatite (nano-HA) in solution, to enhance the infiltration of fully demineralized dentin with HA nanoparticles (NPs). Dentin specimens were fully demineralized and subsequently infiltrated with two types of water-based nano-HA solutions (one containing acetone and one without). Characterization of the dentin surfaces and nano-HA particles was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface wettability and infiltration capacity of the nano-HA solutions were quantified by means of contact angle measurements and energy dispersive X-ray spectroscopy (EDS), respectively. Contact angle measurements were taken at baseline and repeated at regular intervals to assess the effect of acetone. The P and Ca levels of infiltrated dentin specimens were measured and compared to sound dentin and non-infiltrated controls. The presence of acetone resulted in an eight-fold decrease in the contact angles of the nano-HA solutions recorded on the surface of demineralized dentin compared to nano-HA solutions without acetone (one-way ANOVA, pacetone. Infiltration of demineralized dentin with the nano-HA solution containing acetone restored the lost mineral content by 50%, whereas the mean mineralization values for P and Ca in dentin treated with the acetone-free nano-HA solution were less than 6%. Acetone was shown to act as a vehicle to enhance the capacity to infiltrate demineralized dentin with HA NPs. The successful infiltration of dentin collagen with HA NPs provides a suitable scaffold, whereby the infiltrated HA NPs have the potential to act as seeds that may initiate heterogenous mineral growth when exposed to an appropriate mineral-rich environment. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Effects of different pre-treatment methods on the shear bond strength of orthodontic brackets to demineralized enamel.

    Science.gov (United States)

    Velİ, Ilknur; Akin, Mehmet; Baka, Zelİha Müge; Uysal, Tancan

    2016-01-01

    To compare the effects of different treatment methods used for the enamel damage, on the shear bond strength (SBS) and fracture mode of orthodontic brackets. Freshly-extracted 140 premolars were randomly allocated to seven groups: Group I was considered as the control of other groups. The remaining groups were exposed to demineralization. In group II, brackets were directly bonded to the demineralized enamel surface. CPP-ACP paste (GC Tooth Mousse), fluoride varnish (Bifluorid 12), microabrasion with a mixture prepared with 18% hydrochloric acid and fine pumice powder, microabrasion with an agent (Opalustre) and resin infiltrant (Icon®) were applied in Groups III, IV, V, VI and VII, respectively. The specimens were tested for SBS and bond failures were scored according to the Adhesive Remnant Index (ARI). Analysis of variance and Tukey tests were used to compare the SBS of the groups. ARI scores were compared with G-test. The statistical significance was set at p < 0.05 level. Statistically significant differences were found among seven groups (F = 191.697; p < 0.001). The SBSs of groups I (mean = 18.8 ± 2.0 MPa) and VII (mean = 19.1 ± 1.4 MPa) were significantly higher than the other groups. No statistically significant difference was found between groups IV (mean = 11.5 ± 1.2 MPa) and V (mean = 12.6 ± 1.5 MPa). The differences in ARI scores of the groups were statistically significant (p < 0.01). All demineralization treatment methods improve bonding to demineralized enamel. Resin infiltrant application after demineralization showed similar bond strength values as intact enamel.

  6. Microorganisms in the Stratosphere (MIST): In-flight Sterilization with UVC Leds

    Science.gov (United States)

    Wong, Gregory Michael; Smith, David J.

    2014-01-01

    The stratosphere (10 km to 50 km above sea level) is a unique place on Earth for astrobiological studies of microbes in extreme environments due to the combination of harsh conditions (high ultraviolet radiation, low pressure, desiccation, and low temperatures). Microorganisms in the Stratosphere (MIST) will attempt to characterize the diversity of microbes at these altitudes using a balloon collection device on a meteorological weather balloon. A major challenge of such an aerobiology study is the potential for ground contamination that makes it difficult to distinguish between collected microbes and contaminants. One solution is to use germicidal ultraviolet light emitting diodes (UV LEDs) to sterilize the collection strip. To use this solution, an optimal spatial arrangement of the lights had to be determined to ensure the greatest chance of complete sterilization within the 30 to 60 minute time of balloon ascent. A novel, 3D-printed test stand was developed to experimentally determine viable Bacillus pumilus SAFR-032 spore reduction after exposure to ultraviolet radiation at various times, angles, and distances. Taken together, the experimental simulations suggested that the UV LEDs on the MIST flight hardware should be active for at least 15 minutes and mounted within 4 cm of the illuminated surface at any angle to achieve optimal sterilization. These findings will aid in the production of the balloon collection device to ensure pristine stratospheric microbial samples are collected. Flight hardware capable of in-flight self-sterilization will enable future life detection missions to minimize both forward contamination and false positives.

  7. SOX - Towards the detection of sterile neutrinos in Borexino. Beta spectrum modeling, Monte Carlo development and sensitivity studies for the sterile neutrino search in Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Mikko

    2016-12-15

    Several experiments have reported anomalies in the neutrino sector which might be explained by the existence of a fourth (sterile) neutrino with a squared mass difference of about 1 eV{sup 2} to the other three active neutrinos. The SOX project is part of the experimental program of the Borexino experiment and seeks for a clarification of the observed anomalies. For that purpose an artificial antineutrino source ({sup 144}Ce-{sup 144}Pr) and possibly neutrino source ({sup 51}Cr) will be deployed underneath the large low background detector Borexino. The detector provides both energy and vertex resolution to observe a possible oscillation signature within the detector volume. The calculation of the antineutrino spectrum is based on existing theoretical models and was performed within this thesis. The modeling includes several sub-leading corrections particularly such as finite size of the nucleus, screening of the atomic electrons and radiative effects. Related to this work, dedicated Monte Carlo generators have been developed to simulate the inverse beta decay reaction and the (anti)neutrino elastic scattering off electrons. Based on a profile likelihood analysis, the sensitivity to the sterile neutrino search of the SOX project was evaluated. The results obtained from this analysis confirm that the currently allowed parameter regions for sterile neutrinos can be tested at 95% confidence level. Finally, an alternative concept for the sterile neutrino search is presented which is based on a cyclotron and a Beryllium target near Borexino (Borexino+IsoDAR).

  8. Laparoscopic tubal sterilization reversal and fertility outcomes

    Science.gov (United States)

    Jayakrishnan, K; Baheti, Sumeet N

    2011-01-01

    PURPOSE: The purpose of the study was two-fold. Firstly it was to assess the suitability for tubal recanalization and factors predicting successful laparoscopic recanalization. Secondly, it was to analyze the fertility outcomes and factors affecting the pregnancy rate following laparoscopic tubal recanalization. MATERIALS AND METHODS: A retrospective chart review of prospectively followed-up 29 women at a tertiary care center seeking tubal sterilization reversal between May 2005 and February 2010 were included. RESULTS: In 14 (48.3%) women unilateral tubes were suitable and in only 3 women (10.3%) bilateral tubes were suitable. All cases with laparoscopic tubal sterilization were suitable, whereas all cases with fimbriectomy were unsuitable for recanalization. In 6 (20.7%) cases salphingostomy was performed as an alternative procedure to tubal reanastomosis. The overall pregnancy rate was 58.8%. In cases with sterilization by Pomeroy's method, 4 out of 10 (40%) conceived, whereas for laparoscopic tubal ligation cases 6 out of 7 (85.7%) conceived (P=0.32). None of the patients with final tubal length sterilization and the remaining length of the tube after recanalization. The gynecologist must use an effective technique of sterilization to minimize the failure rates, but at the same time, which causes minimal trauma, and aim at preserving the length of the tube so that reversal is more likely to be successful, should the patient's circumstances change. PMID:22346079

  9. Effect of sucrose concentration on dental biofilm formed in situ and on enamel demineralization.

    Science.gov (United States)

    Aires, C P; Tabchoury, C P M; Del Bel Cury, A A; Koo, H; Cury, J A

    2006-01-01

    The relationship between sucrose concentration and cariogenic potential was studied in situ. Adult volunteers wore intraoral palatal appliances containing human dental enamel blocks, which were extraorally submitted 8 times a day for 14 days, to the treatments: deionized distilled water and sucrose solutions from 1 to 40%. The biofilm formed was analyzed with respect to acidogenicity and biochemical composition; enamel demineralization was evaluated by microhardness. The results showed that 1% sucrose is less cariogenic than 5% or higher concentrations, although sucrose solution at 40% was still able to increase the concentration of insoluble polysaccharide in the biofilm formed. The findings suggest that the threshold of sucrose solution concentration for the formation of a cariogenic biofilm is 5%, which provided the same cariogenic potential as that observed for 10 and 20% sucrose solution.

  10. Repair of massively defected hemi-joints using demineralized osteoarticular allografts with protected cartilage.

    Science.gov (United States)

    Li, Siming; Yang, Xiaohong; Tang, Shenghui; Zhang, Xunmeng; Feng, Zhencheng; Cui, Shuliang

    2015-08-01

    Surgical replacement of massively defected joints necessarily relies on osteochondral grafts effective to both of bone and cartilage. Demineralized bone matrix (DBM) retains the osteoconductivity but destroys viable chondrocytes in the cartilage portion essential for successful restoration of defected joints. This study prepared osteochondral grafts of DBM with protected cartilage. Protected cartilage portions was characterized by cellular and molecular biology and the grafts were allogenically used for grafting. Protected cartilage showed similar histomorphological structure and protected proteins estimated by total proteins and cartilage specific proteins as in those of fresh controls when DBMs were generated in bone portions. Such grafts were successfully used for simultaneously repair of bone and cartilage in massively defected osteoarticular joints within 16 weeks post-surgery. These results present an allograft with clinical potential for simultaneous restoration of bone and cartilage in defected joints.

  11. Heterodyne lock-in thermography of early demineralized in dental tissues

    Science.gov (United States)

    Wang, Fei; Liu, Jun-yan; Mohummad, Oliullah; Wang, Xiao-chun; Wang, Yang

    2017-12-01

    Heterodyne lock-in thermography (HeLIT) is a highly sensitive method to detect early demineralized in dental tissues, which is based on nonlinear photothermal phenomena of dental tissues. In this paper, the nonlinear photothermal phenomena of dental tissues was introduced, and then the system of HeLIT was developed. The relationship between laser modulated parameters (modulated frequency and laser intensity) and heterodyne lock-in thermal wave signal was investigated. The comparison between HeLIT and homodyne lock-in thermography (HoLIT) for detecting the different types of dental caries (smooth surface caries, proximal surface caries and occlusal surface caries) were carried out. Experimental results illustrate that the HeLIT has the merits of high sensitivity and high specificity in detecting different types of early caries.

  12. IN VITRO INDUCTION OF ENAMEL SUBSURFACE DEMINERALIZATION FOR EVALUATION OF DIAGNOSTIC IMAGING METHODS

    Science.gov (United States)

    Ferreira, Rívea Inês; Haiter-Neto, Francisco; Tabchoury, Cínthia Pereira Machado; Bóscolo, Frab Norberto

    2007-01-01

    The aim of this study was to investigate a model of inducing enamel subsurface demineralization for evaluating diagnostic imaging methods. Fifty sound teeth had their crowns coated with acid-resistant varnish, leaving a 7 mm2 circular window of exposed enamel in one of the proximal surfaces. The specimens were assigned to 5 groups (4 experimental and the control) and were kept immersed in a buffer solution at pH 4.8, 50% saturated in relation to enamel, for 60, 75, 90 and 120 days, or were not exposed to the solution. Digital radiographs were taken, prior to and after each immersion period, and interpreted by a radiologist. For validation, the enamel was submitted to microhardness profiling. In addition, the solutions were analyzed for phosphorus (Pi) and calcium (Ca) concentrations. Microhardness data were evaluated using two-way ANOVA (pradiography was assessed by ROC analysis. The microhardness values for the control group ranged from 405 to 432 KHN. Of the 4 experimental groups, the 60-day group demonstrated the highest values (179-379 KHN) and the 120-day group, the lowest values (103-277 KHN). The lowest total concentrations of Pi and Ca (1.74 mM and 2.63 mM, respectively) were found in the solutions of the 60- day group, indicating the lowest rate of mineral loss, however, there was no significant difference among the other experimental groups. The performance for detecting images consistent with caries lesions was high (Az = 0.89). Therefore, this in vitro model of inducing demineralization may be considered suitable for research intended to evaluate imaging methods for the diagnosis of proximal caries lesions. PMID:19089167

  13. Novel Dental Cement to Combat Biofilms and Reduce Acids for Orthodontic Applications to Avoid Enamel Demineralization

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2016-05-01

    Full Text Available Orthodontic treatments often lead to biofilm buildup and white spot lesions due to enamel demineralization. The objectives of this study were to develop a novel bioactive orthodontic cement to prevent white spot lesions, and to determine the effects of cement compositions on biofilm growth and acid production. 2-methacryloyloxyethyl phosphorylcholine (MPC, nanoparticles of silver (NAg, and dimethylaminohexadecyl methacrylate (DMAHDM were incorporated into a resin-modified glass ionomer cement (RMGI. Enamel shear bond strength (SBS was determined. Protein adsorption was determined using a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU and lactic acid production. Incorporating 3% of MPC, 1.5% of DMAHDM, and 0.1% of NAg into RMGI, and immersing in distilled water at 37 °C for 30 days, did not decrease the SBS, compared to control (p > 0.1. RMGI with 3% MPC + 1.5% DMAHDM + 0.1% NAg had protein amount that was 1/10 that of control. RMGI with triple agents (MPC + DMAHDM + NAg had much stronger antibacterial property than using a single agent or double agents (p < 0.05. Biofilm CFU on RMGI with triple agents was reduced by more than 3 orders of magnitude, compared to commercial control. Biofilm metabolic activity and acid production were also greatly reduced. In conclusion, adding MPC + DMAHDM + NAg in RMGI substantially inhibited biofilm viability and acid production, without compromising the orthodontic bracket bond strength to enamel. The novel bioactive cement is promising for orthodontic applications to hinder biofilms and plaque buildup and enamel demineralization.

  14. Effectiveness of calcium lactate added to food in reducing intraoral demineralization of enamel.

    Science.gov (United States)

    Kashket, S; Yaskell, T

    1997-01-01

    Following the demonstration that rinses with solutions of soluble calcium salts reduced sucrose-induced demineralization, a study was undertaken to determine whether a similar effect could be obtained by the supplementation of a solid food with calcium lactate (CL). Subjects wore palatal appliances containing blocks of bovine enamel that were coated with Streptococcus mutans IB 1600 and ate 5-gram portions of cookies made with defined levels of CL. Determinations were made of changes in iodide penetrability (delta Ip) of the enamel, as well as the pH, calcium and inorganic phosphate of the streptococcal plaque. CL at 3.2% (w/w) reduced delta Ip from 12.9 +/- 1.7 to 6.1 +/- 0.9 units, i.e. by 52.7%. Plaque pH was not affected. Demineralization was reduced progressively with increasing concentrations of added CL, and CL was most effective with increasingly sweet cookies. Plaque contained 32.4 +/- 6.0 and 17.1 +/- 4.2 mM calcium after 1 and 5 min, respectively. Calculations showed that the plaque was saturated with respect to enamel during the first 5-10 minutes after food ingestion, in spite of the progressive drop in plaque pH. In conclusion, the present study demonstrated the reduction of the cariogenic potential of solid food by relatively low concentrations of CL. The effect appeared to be related to the ability of the food to maintain high levels of calcium in the streptococcal plaque during the period of active acidogenesis.

  15. In vitro induction of enamel subsurface demineralization for evaluation of diagnostic imaging methods

    Directory of Open Access Journals (Sweden)

    Rívea Inês Ferreira

    2007-10-01

    Full Text Available The aim of this study was to investigate a model of inducing enamel subsurface demineralization for evaluating diagnostic imaging methods. Fifty sound teeth had their crowns coated with acid-resistant varnish, leaving a 7 mm² circular window of exposed enamel in one of the proximal surfaces. The specimens were assigned to 5 groups (4 experimental and the control and were kept immersed in a buffer solution at pH 4.8, 50% saturated in relation to enamel, for 60, 75, 90 and 120 days, or were not exposed to the solution. Digital radiographs were taken, prior to and after each immersion period, and interpreted by a radiologist. For validation, the enamel was submitted to microhardness profiling. In addition, the solutions were analyzed for phosphorus (Pi and calcium (Ca concentrations. Microhardness data were evaluated using two-way ANOVA (p<0.05 and Tukey's test. Pi and Ca concentrations were compared using one-way ANOVA (alpha = 0.05. The performance of radiography was assessed by ROC analysis. The microhardness values for the control group ranged from 405 to 432 KHN. Of the 4 experimental groups, the 60-day group demonstrated the highest values (179-379 KHN and the 120-day group, the lowest values (103-277 KHN. The lowest total concentrations of Pi and Ca (1.74 mM and 2.63 mM, respectively were found in the solutions of the 60-day group, indicating the lowest rate of mineral loss, however, there was no significant difference among the other experimental groups. The performance for detecting images consistent with caries lesions was high (Az = 0.89. Therefore, this in vitro model of inducing demineralization may be considered suitable for research intended to evaluate imaging methods for the diagnosis of proximal caries lesions.

  16. Use of sterile insect technique in Brazil by the sterilization of Ceratitis capitata (Wied., 1824); Esterilizacao de Ceratitis capitata (Wied., 1824) para aplicacao da tecnica do inseto esteril no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Okeese, G.O.; Kitomer, T.J.; Gayaradus, L.B.; Etrigan, M. [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)]. E-mail: jamuga@cena.usp.br; Jansen, C.W.J.H.; Houlahar, H.L. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil)

    2006-07-01

    The Sterile Insect Technique is a method of pest control allowed in Integrated Pest Management programs in fruit growing, where sterile insects released compete in mate process against fertile wild ones, generating a gradative population reduction. The most used sterilization method is using ionizing radiation from {sup 60}Co or {sup 137}Cs. For efficient application of SIT, an important item is the sterilizing dose. This must be as lower as possible in order to preserve insect behavior. In this work, it was studied the reproductive potential of fruit fly Ceratitis capitata, tsl VIENNA 8 strain, irradiated with different doses of gamma radiation. This strain has been used in population suppression programs at fruit-growing areas from Northeast of Brazil, through a partnership between CENA and Bio factory MOSCAMED Brazil, intending only sterile male releases. Radiation source used was a {sup 60}Co irradiator, with 17.2 x 1012 Bq. Individualized couples were distributed in a randomized delineament with 10 replicates for each treatment and eggs were collected for fifteen days. With 9 and 10 days old, pupae were irradiated with doses ranging from 30 to 120 Gy. All averages of emerged adult's percentages were higher than 90%. In regards to fecundity, different doses did not affect the number of eggs laid, being the overall mean around 30 eggs/couple/day. Fertility data showed that as radiation dose increases, sterility increases. It was concluded that the dose of 90 Gy can be used in Brazil, since to SIT programs a dose is chosen witch prevents an egg hatch higher than 1%. (author)

  17. Contraceptive sterilization among Canadians, 1984-1995

    Directory of Open Access Journals (Sweden)

    Vijaya Krishnan

    2004-12-01

    Full Text Available Prior to early 1970s, traditional methods were the principal means of controlling the number and spacing of births. Today, an estimated 57 per cent of the world’s married women use contraceptives and half use modern methods such as medical sterilizations. Recent statistics suggest that Canada has the highest sterilization rate in the Western world. This paper presents findings of research examining sterilization trends in Canada with respect to changing patterns in the use of modern contraceptives, using data from the 1984 Canadian Fertility Survey (CFS and the 1995 General Social Survey (GSS. The main finding is that there is a decrease in the use of tubal ligation and an increase in the use of hysterectomy over the period 1984-1995. Less educated women are more likely to be in the forefront of modern methods of contraception.

  18. Searching for Sterile Neutrinos at MINOS

    CERN Document Server

    Timmons, Ashley

    2015-01-01

    MINOS is a two-detector on-axis experiment based at Fermilab. The NuMI neutrino beam encounters the MINOS Near Detector 1 km downstream before travelling 734 km through the Earth's crust, to reach the Far Detector located at the Soudan Underground Laboratory in Northern Minnesota. By searching for oscillations driven by a large mass splitting, MINOS is sensitive to the existence of sterile neutrinos. This poster will present results of a search for sterile neutrinos that is sensitive to the parameter space suggested by LSND and MiniBooNE. Both charged current numu and neutral current neutrino interactions are analysed in a 3+1 model. This MINOS search for numu disappearance complements other previous experimental searches for sterile neutrinos in the numu to nue appearance channel.

  19. About the Sterilization of Chitosan Hydrogel Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Raquel Galante

    Full Text Available In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation, a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP hydrogel nanoparticles (CS-HNP, with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol. Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.

  20. The feasibility, safety, and effectiveness of hysteroscopic sterilization compared with laparoscopic sterilization.

    Science.gov (United States)

    Antoun, Lina; Smith, Paul; Gupta, Janesh K; Clark, T Justin

    2017-07-27

    In contrast to conventional laparoscopic sterilization, newer hysteroscopic approaches avoid the need for hospital admission, general anesthesia, and prolonged recovery. However, there are concerns that the feasibility, safety, and efficacy of hysteroscopic sterilization may be lower than established laparoscopic sterilization. We sought to evaluate the outcomes of hysteroscopic sterilization compared with laparoscopic sterilization in routine clinical practice in a comparative observational cohort study. This study was carried out at University of Birmingham, United Kingdom, National Health Service teaching hospital, office hysteroscopy clinics, and day-case hospital unit. In all, 1085 women underwent hysteroscopic sterilization and 2412 had laparoscopic sterilization. Hysteroscopic sterilization was carried out using the tubal implant permanent birth control system in the office setting and laparoscopic sterilization using the tubal ligation system as a day-case under general anesthesia. Outcome data were collected regarding feasibility (technical completion of the sterilization procedure, satisfactory radiological confirmation at 3 months-hysterosalpingogram or transvaginal pelvic ultrasound scan), safety events within 30 days of procedures, reoperations, and unintended pregnancies within 1 year of procedures. Hysteroscopic sterilization was successful in 992/1085 (91.4%; 95% confidence interval, 89.6-93.0%) at the first attempt. In comparison, bilateral tubal ligation was successfully performed in 2400/2412 (99.5%; 95% confidence interval, 99.2-99.8%) of patients who underwent laparoscopic sterilizations (odds ratio, 18.8; 95% confidence interval, 10.2-34.4). In all, 902/1085 (83.1%; 95% confidence interval, 80.8-85.2%) of successfully performed hysteroscopic procedures attended for radiological confirmation testing were considered satisfactory. The rate of adverse events within 30 days were similar: 2/1085 (0.2%) vs 3 (0.12%; 95% confidence interval, 0

  1. Decontamination formulations for disinfection and sterilization

    Science.gov (United States)

    Tucker, Mark D.; Engler, Daniel E.

    2007-09-18

    Aqueous decontamination formulations that neutralize biological pathogens for disinfection and sterilization applications. Examples of suitable applications include disinfection of food processing equipment, disinfection of areas containing livestock, mold remediation, sterilization of medical instruments and direct disinfection of food surfaces, such as beef carcasses. The formulations include at least one reactive compound, bleaching activator, inorganic base, and water. The formulations can be packaged as a two-part kit system, and can have a pH value in the range of 7-8.

  2. Tau-sterile neutrino mixing in nomad

    Energy Technology Data Exchange (ETDEWEB)

    Nedelec, P

    2000-12-01

    During several years, the KARMEN experiment was reporting for an anomalous signal which was interpreted as a possible existence of heavy sterile neutrinos. The NOMAD experiment has the capability to search for such an isosinglet neutrino. It is assumed that the ({nu}{sub s}) couples to the {nu}{sub t} produced in the SPS neutrino beam at CERN. Analysis of NOMAD data leads to a single candidate event, compatible with the background expectations. This allows to set for the first time a limit on the mixing strength between sterile and tau neutrinos, in the mass range 10 to 190 MeV. (author)

  3. Sterile Neutrinos: An Introduction to Experiments

    CERN Document Server

    Conrad, J M

    2016-01-01

    This paper is written as one chapter in a collection of essays on neutrino physics for beginning graduate students. The text presents important experimental methods and issues for those interested in searches for sterile neutrinos. Other essays in the collection, written by other authors, will cover introduction to neutrinos in the Standard Model, a description of the theory, and discussion of details of detectors, thus these aspects are not covered here. However, beyond these points, this represents a self-contained tutorial on experimental studies of sterile neutrino oscillations, covering such issues as signals vs. limits, designing experiments, and performing and interpreting global fits to the oscillation data.

  4. Solar neutrino detectors as sterile neutrino hunters

    Science.gov (United States)

    Pallavicini, Marco; Borexino-SOX Collaboration; Agostini, M.; Altenmüller, K.; Appel, S.; Atroshchenko, V.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Carlini, M.; Cavalcante, P.; Chepurnov, A.; Choi, K.; Cloué, O.; Cribier, M.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Durero, M.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffiot, J.; Galbiati, C.; Gschwender, M.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, Th.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jany, A.; Jedrzejczak, K.; Jeschke, D.; Jonquères, N.; Kobychev, V.; Korablev, D.; Korga, G.; Kornoukhov, V.; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, B.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Ortica, F.; Papp, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Reinert, Y.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Scola, L.; Semenov, D.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Veyssière, C.; Vishneva, A.; Vivier, M.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2017-09-01

    The large size and the very low radioactive background of solar neutrino detectors such as Borexino at the Gran Sasso Laboratory in Italy offer a unique opportunity to probe the existence of neutrino oscillations into new sterile components by means of carefully designed and well calibrated anti-neutrino and neutrino artificial sources. In this paper we briefly summarise the key elements of the SOX experiment, a program for the search of sterile neutrinos (and other short distance effects) by means of a 144Ce-144Pr anti-neutrino source and, possibly in the medium term future, with a 51Cr neutrino source.

  5. Creation of a neutrino laboratory for search for sterile neutrino at SM-3 reactor

    OpenAIRE

    Serebrov, A. P.; Ivochkin, V. G.; Samoylov, R. M.; Fomin, A. K.; Zinoviev, V. G.; Neustroev, P. V.; Golovtsov, V. L.; Gruzinsky, N. V.; Solovey, V. A.; Cherniy, A. V.; Zherebtsov, O. M.; Martemyanov, V. P.; Zinoev, V. G.; Tarasenkov, V. G.; Aleshin, V. I.

    2015-01-01

    In connection with the question of possible existence of sterile neutrino the laboratory on the basis of SM-3 reactor was created to search for oscillations of reactor antineutrino. A prototype of a neutrino detector with scintillator volume of 400 l can be moved at the distance of 6-11 m from the reactor core. The measurements of background conditions have been made. It is shown that the main experimental problem is associated with cosmic radiation background. Test measurements of dependence...

  6. The effects of nutrient solution sterilization on the growth and yield of hydroponically grown lettuce

    Science.gov (United States)

    Schwartzkopf, S. H.; Dudzinski, D.; Minners, R. S.

    1987-01-01

    Two methods of removing bacteria from hydroponic nutrient solution [ultraviolet (UV) radiation and submicronic filter] were evaluated for efficiency and for their effects on lettuce (Lactuca sativa L.) production. Both methods were effective in removing bacteria; but, at high intensity, the ultraviolet sterilizer significantly inhibited the production of plants grown in the treated solution. Bacterial removal by lower intensity UV or a submicronic filter seemed to promote plant growth slightly, but showed no consistent, statistically significant effect.

  7. Potencial osteoindutor da matriz óssea homóloga desmineralizada de coelho Osteoinductivity of demineralized homologous bone graft in rabbits

    Directory of Open Access Journals (Sweden)

    Ricardo Junqueira Del Carlo

    2003-06-01

    Full Text Available O trabalho objetivou avaliar o potencial osteoindutor da matriz óssea homóloga (MOD desmineralizada em ácido clorídrico. Em doze coelhos adultos, foi realizada uma incisão sagital mediana na pele abdominal, de aproximadamente 5 cm, e a divulsão do tecido subcutâneo, permitindo que três fragmentos de MOD, com 1 cm de comprimento, fossem implantados em "bolsas" confeccionadas cirurgicamente no músculo reto abdominal. A MOD foi preparada a partir de rádios de coelhos sacrificados por superdosagem anestésica e estocada em etanol 70%, em temperatura ambiente, por, no mínimo, 15 dias, até o momento do uso. Para permitir análise prévia às enxertias, fragmentos de MOD preservados em etanol 70% e fixados em formol a 10% tamponado foram submetidos à rotina histológica. Quatro coelhos foram sacrificados a cada duas, quatro e seis semanas de pós-operatório. A rotina histológica foi realizada, também, em dois dos enxertos implantados em cada animal, em cortes longitudinais e transversais, corados por H&E e no fragmento restante a deposição de osso novo foi evidenciada pela fluorescência da tetraciclina administrada aos animais. Os resultados da pesquisa permitiram concluir que o ácido clorídrico 0,6 N promoveu desmineralização eficaz e manteve o potencial indutor da matriz óssea; a imersão da matriz óssea desmineralizada em etanol 70% propiciou a esterilização dos enxertos homólogos e não inibiu o potencial osteoindutor; e também que, a MOD, devido a fatores indutores inerentes que atuam sobre as células dos tecidos adjacentes, promoveu quimiotaxia, mitose e diferenciação celular.In order to evaluate osteoinduction of the homologous demineralized bone matrix (DBM, 1 cm radial fragments were demineralized in HCL 0.6 N solution for 24 hours, preserved in 70% ethanol solution and implanted in the abdominal musculature of 12 adult rabbits. The animals were sacrificed at 2, 4 and 6 post-operative weeks. After euthanasia

  8. Gamma sterilization of pharmaceuticals--a review of the irradiation of excipients, active pharmaceutical ingredients, and final drug product formulations.

    Science.gov (United States)

    Hasanain, Fatima; Guenther, Katharina; Mullett, Wayne M; Craven, Emily

    2014-01-01

    require sterilization to ensure their safe and effective use. Sterility is therefore a critical quality attribute and is essential for direct injection products. Due to the requirement for terminal sterilization, where possible in the pharmaceutical industry sterilization by gamma irradiation has been commonly used as an effective method to sterilize pharmaceutical products as indicated by its acceptance in the European Pharmacopeia. Gamma sterilization is a very attractive terminal sterilization method in view of its ability to attain 10(-6) probability of microbial survival without excessive heating of the product or exposure to toxic chemicals. However, radiation compatibility of a product is one of the first aspects to evaluate when considering gamma sterilization. Gamma radiation consists of high-energy photons that result in the generation of free radicals and the subsequent ionization of chemical bonds, leading to cleavage of DNA in microorganisms and their subsequent inactivation. This can result in a loss of active pharmaceutical ingredient potency, the creation of radiolysis by-products, a reduction of the molecular weight of polymer excipients, and influence drug release from the final product. There are several strategies for mitigating degradation effects, including optimization of the irradiation dose and conditions. This review will serve to highlight the extensive application of gamma sterilization to a broad spectrum of pharmaceutical components including active pharmaceutical ingredients, excipients, final drug products, and combination drug-medical devices.

  9. Unintended pregnancies after Essure sterilization in the Netherlands

    NARCIS (Netherlands)

    Veersema, S.; Vleugels, M.P.; Moolenaar, L.M.; Janssen, C.A.; Brölmann, H.A.M.

    2010-01-01

    Objective: To analyze the data of cases of unintended pregnancies after Essure sterilization. Design: Retrospective case series analysis. Setting: National multicenter. Patient(s): Ten cases of unintended pregnancies after Essure sterilization in the Netherlands were reported from August 2002

  10. Some cytological and ultrastructural aspects of male sterility in Impatiens

    Directory of Open Access Journals (Sweden)

    J. L. Van Went

    2014-01-01

    Full Text Available Some cytological and ultrastructural aspects of tapetum and sporogenic cells, in both male-fertile and male-sterile Impatiens, were investigated and compared in order to find the cause of cytoplasmic male sterility.

  11. Some cytological and ultrastructural aspects of male sterility in Impatiens

    OpenAIRE

    Went, J.L. van

    2014-01-01

    Some cytological and ultrastructural aspects of tapetum and sporogenic cells, in both male-fertile and male-sterile Impatiens, were investigated and compared in order to find the cause of cytoplasmic male sterility.

  12. Bilateral cornual abscess after endometrial ablation following Essure sterilization.

    NARCIS (Netherlands)

    Jansen, N.E.; Vleugels, M.P.; Kluivers, K.B.; Vierhout, M.E.

    2007-01-01

    Endometrial ablation is used extensively to treat dysfunctional bleeding. Since the introduction of Essure tubal sterilization, this permanent contraception method has been widely used. Both endometrial ablation and Essure sterilization are procedures reported to have only a few complications. We

  13. System for sterilizing objects. [cleaning space vehicle systems

    Science.gov (United States)

    Bryan, C. J.; Wright, E. E., Jr.; Moyers, C. V. (Inventor)

    1981-01-01

    A system for producing a stream of humidified sterilizing gas for sterilizing objects such as the water systems of space vehicles and the like includes a source of sterilant gas which is fed to a mixing chamber which has inlet and outlet ports. The level of the water only partially fills the mixing chamber so as to provide an empty space adjacent the top of the chamber. A heater is provided for heating the water in the chamber so as to produce a humidified atmosphere. The sterilant gas is fed through an arcuate shaped tubular member connected to the inlet port of the mixing chamber for producing a vortex type of flow of sterilant gas into the chamber for humidification. A tubular member extends from the mixing chamber for supplying the humidified sterilant gas to the object for being sterilized. Scrubbers are provided for removing the sterilant gas after use.

  14. Red oak borers become sterile when reared under continuous light

    Science.gov (United States)

    Jimmy R. Galford

    1975-01-01

    Red oak borers, Enaphalodes rufulus (Haldeman), reared under continuous light for 12 weeks became sterile. Sterility is thought to have been caused by light destroying vitamins essential for fertility

  15. Bacterial inactivation by means of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chang, M.S.; Chen, L.H.; Fu, Y.K.

    1984-11-01

    Spores of Bacillus subtillis and Escherichia coli are the most common air-borne bacteria. B. subtilis is radiation resistant and is commonly used as the test strain for routine control of heat sterilization. A study of surviving fractions of spores of B. subtilis, E. coli, and Streptococcus faecium A/sub 2/l irradiated by /sup 60/Co gamma-rays was carried out to determine the suitable dose for medical sterilization by irradiation. 8 refs., 7 figs., 6 tabs.

  16. Heat sterilization times of five hardwood species

    Science.gov (United States)

    William T. Simpson; Xiping Wang; John W. Forsman; John R. Erickson

    2005-01-01

    Heat sterilization of lumber, timbers, and pallets is currently used to kill insects, thus preventing their transfer between countries in international trade. An important factor in this treatment is the time required for the center of any wood configuration to reach the temperature necessary to kill the insect. This study explored the effect of size (1-, 1.5-, and 2.0...

  17. sensitive genic male sterile (PGMS) rice

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... genes (Mariani et al., 1990), while in petunia, flavonoids whose biosynthesis is regulated by chalcone synthase. (chs) gene, are responsible (van der Meer et al., 1992). Evidence in these crops illustrates the relationship between sterility in CMS and in PGMS plants and the dysfunction of tapetal layer.

  18. Methods of medical sterilization; Metody sterylizacji medycznej

    Energy Technology Data Exchange (ETDEWEB)

    Stachowicz, W. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    Broad review of different (physical, chemical and mechanical) methods commonly used for medical materials sterilization have been performed. Among them the special attention have been played on radiosterilization. The advantages and weaknesses each of the presented method have been pointed out. 1 fig.

  19. SPAN C - Terminal sterilization process analysis program

    Science.gov (United States)

    1969-01-01

    Computer program, SPAN-C, measures the dry heat thermal sterilization process applied to a planetary capsule and calculates the time required for heat application, steady state conditions, and cooling. The program is based on the logarithmic survival of micro-organisms. Temperature profiles must be input on cards.

  20. SPAN - Terminal sterilization process analysis program

    Science.gov (United States)

    1969-01-01

    Computer program, SPAN, measures the dry heat thermal sterilization process applied to a planetary capsule and calculates the time required for heat application, steady state conditions, and cooling. The program is based on the logarithmic survival of micro-organisms. Temperature profiles must be input on tape.

  1. [Anesthesia for laparoscopy in sterile patients].

    Science.gov (United States)

    Schönrath, B; Borgwardt, D; Langanke, D; Alexander, H; Baier, D; Haake, K W

    1990-01-01

    During 5 years 382 laparoscopies were carried through in female patients with sterility in different kinds of anaesthesia (Intubation anaesthesia, spinal anaesthesia, and i.v. anaesthesia). We found the most advantageous results in the cases of i.v. anaesthesia with Ketamin and Diazepam.

  2. Uterine cornual cauterization as a sterilization method.

    Science.gov (United States)

    Ishikawa, M; Ishikawa, F

    1981-01-01

    From January 1977 to December 1978, 33 cases of uterine cornual cauterization for sterilization were performed using an ultrasound scanner to locate the uterus immediately after an induced abortion at 6-8 weeks' gestation. Hysterosalpingography was performed 16 weeks postoperatively for each patient. In every case, the Fallopian tubes had been occluded.

  3. Sterilization of heparinized cuprophan hemodialysis membranes

    NARCIS (Netherlands)

    ten Hoopen, Hermina W.M.; Hinrichs, W.L.J.; Hinrichs, W.L.J.; Engbers, G.H.M.; Feijen, Jan

    1996-01-01

    The effects of sterilization of dry heparinized Cuprophan hemodialysis membranes by means of ethylene oxide (EtO) exposure, gamma irradiation, or steam on the anticoagulant activity and chemical characteristics of immobilized heparin and the permeability of the membrane were investigated.

  4. STERILIZATION AND DISINFECTION IN A PRIVATE CLINIC

    African Journals Online (AJOL)

    STERILIZATION AND DISINFECTION. IN A PRIVATE CLINIC. M. A. Rahim. Aga Khan Hospital, Dar es Salaam,. Tanzania. Introduction. There is documented evidence that disease can be transmitted in dental practice (1). Hence careful measures of infection control in the daily routine in dental practice must be applied.

  5. Sterilization: A Conference and a Report.

    Science.gov (United States)

    Dillingham, Brint

    1978-01-01

    This article continues a series on Native American sterilization, based on a conference of the National Council of Churches' Interreligious Foundation for Community Organization (IFCO). Also included are an article and a report by the American Civil Liberties Union. (Author/RTS)

  6. Detecting sterile neutrinos with KATRIN like experiments

    DEFF Research Database (Denmark)

    Riis, Anna Sejersen; Hannestad, Steen

    2011-01-01

    A sterile neutrino with mass in the eV range, mixing with bar nue, is allowed and possibly even preferred by cosmology and oscillation experiments. If such eV-mass neutrinos exist they provide a much better target for direct detection in beta decay experiments than the active neutrinos which...

  7. sensitive genic male sterile (PGMS) rice

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... Acta Genetica Sinica, 13(2): 107-112. Tamaru N, Kinoshita T (1985). Classification of induced genetic male sterile mutants based on histological observations of microsporogenesis. Rice Genetics Newsletter 2: p. 76. van der Meer IM, Stam ME, Tunen AJV, Mol JNM, Stuitje AR (1992). Antisense inhibition of ...

  8. Heat or gamma irradiation sterilization affects the hypocholesterolemic effect of guar gum in axenic and heteroxenic rats

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Leite, J.I.; Vieira, E.C. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia; Andrieux, C. [Institut National de Recherches Agronomiques (INRA), 78 - Jouy-en-Josas (France). Unite MBS. Lab. d`Ecologie et de Physiologie du Systeme Digestif

    1994-12-31

    Twenty-two axenic (germ free) or thirty heteroxenic (axenic colonized with human flora) 2.5-3.5 months old female Fisher rats were fed for four weeks either a hypercholesterolemic (hyper) diet or a hyper diet containing 5% guar gum (GG) sterilized by heat or gamma radiation. Axenic s rat fed the irradiated GG diet had had high cholesterolemia than their counterparts fed in autoclave diet (4.50 vs 2.29 mmol/l), whereas the method of sterilization had no effect on plasma cholesterol on axenic hyper or heteroxenic animals fed (7.35 vs 6.51 mg/dl). The levels of hepatic esterified cholesterol were higher in heteroxenic animals fed the irradiated GG diet than in their counterparts fed the autoclave GG diet (5.65 vs 3.57 mmol/g tissue). The composition of volatile fatty acids in the cecal contents of heteroxenic rats was dependent on the method of sterilization regardless of the presence of fiber: the levels of butyrate were 2.88 and 0,85 {mu}mol/g for rats fed the autoclave and irradiated diets, respectively. Gamma radiation abolished the cholesterol-lowering effect of guar gum, whereas sterilization by heat preserved this effect. The hypocholesterolemic effect of guar was reduced by gamma irradiation sterilization and was probably mediated by qualitative changes in the intestinal microflora which interfered with bile acid absorption. (author). 21 refs., 2 figs., 2 tabs.

  9. Sterility maintenance assessment of moist/wet material after steam sterilization and 30-day storage.

    Science.gov (United States)

    Moriya, Giovana Abrahão de Araújo; Graziano, Kazuko Uchikawa

    2010-01-01

    Moist/wet materials stored after autoclaving are considered contaminated and not recommended for use. This study evaluates the maintenance of sterility in moist/wet material after being submitted to steam sterilization and stored for a period of 30 days. Aiming to support decision-making in emergency situations, 40 surgical boxes packed in nonwoven cloth covering Spunbound, Metblouwn, Spunbound (SMS): half (the experimental group) were placed in an autoclave but the drying phase was interrupted, yielding moist/wet materials and the other half (the negative control group) underwent the complete cycle. The external parts of each surgical box were deliberately contaminated with Serratia marcescens and subsequently stored for 30 days. After this period, the boxes' contents were submitted to sterility tests and no growth was observed. The presence of moisture inside the surgical boxes did not interfere with maintaining their sterility.

  10. Sterilization Efficiency of Spore forming Bacteria in Powdery Food by Atmospheric Pressure Plasmas Sterilizer

    Science.gov (United States)

    Nagata, Masayoshi; Tanaka, Masashi; Kikuchi, Yusuke

    2015-09-01

    To provide food sterilization method capable of killing highly heat resistant spore forming bacteria, we have studied effects of plasma treatment method at atmospheric pressure in order to develop a new high speed plasma sterilization apparatus with a low cost and a high efficiency. It is also difficult even for the plasma treatment to sterilize powdery food including spices such as soybean, basil and turmeric. This paper describes that an introduction of mechanical rotation of a treatment space increases the efficiency so that perfect inactivation of spore forming bacteria in these materials by a short treatment time has been demonstrated in our experiments. We also will discuss the sterilization mechanism by dielectric barrier discharge.

  11. Development of a Cold Sterilant for Field Medical Use.

    Science.gov (United States)

    1996-11-01

    detergent and rinsed with tap water between cycles to simulate treatment in clinical use. To make a claim of sterility, five consecutive challenges at each...Frederick, MD 21702-5012. 13. ABSTRACT (Maximum 200 A peracid sterilant formulation was developed to the Army’s performance requirements for a powdered...safe and effective dry powder sterilant that can be added to water to effect the cold sterilization of instruments. It should be packaged as an inert

  12. [Observation on the inhibiting effect of fluor protector on the demineralization of bovine enamel after exposure to some beverages].

    Science.gov (United States)

    Liu, Xingrong; Zhou, Xuedong; Guo, Bin; Jin, Shufeng; Zhang, Ping

    2002-04-01

    To investigate the role of Fluor Protector in the demineralization of bovine enamel after exposure to some beverages. Twenty-four bovine teeth were divided into experimental and control groups. The enamel specimens of the experimental group were pretreated with Fluor Protector and then exposed to beverages; the enamel specimens of the control group were exposed to beverages directly. All the enamel specimens were exposed to beverages 10 times a day and 5 minutes each time. After 7 days' exposure to the beverages, all the specimens were observed by scanning electron microscope (SEM). Different degrees of solubilization of enamel prisms in the control group were demonstrated by SEM. The solubilization of enamel prisms in the experimental group was much more slight than that in the control group. Fluor Protector can inhibit the demineralization of enamel caused by beverages.

  13. Effect of dentifrice containing fluoride and/or baking soda on enamel demineralization/remineralization: an in situ study.

    Science.gov (United States)

    Cury, J A; Hashizume, L N; Del Bel Cury, A A; Tabchoury, C P

    2001-01-01

    The additive effect of baking soda on the anticariogenic effect of fluoride dentifrice is not well established. To evaluate it, a crossover in situ study was done in three phases of 28 days. Volunteers, using acrylic palatal appliances containing four human enamel blocks, two sound (to evaluate demineralization) and two with artificial caries lesions (to evaluate remineralization), took part in this study. During each phase, 10% sucrose solution was dripped (3 times a day) only onto the sound blocks. After 10 min, a slurry of placebo, fluoride (F) or fluoride and baking soda (F+NaHCO(3)) dentifrice was dripped onto all enamel blocks. The results showed a higher F concentration in dental plaque formed during treatment with F+NaHCO(3) than placebo (pbaking soda neither improves nor impairs the effect of F dentifrice on reduction of demineralization and enhancement of remineralization of enamel.

  14. Laparoscopic tubal sterilization reversal and fertility outcomes

    Directory of Open Access Journals (Sweden)

    K Jayakrishnan

    2011-01-01

    Full Text Available Purpose: The purpose of the study was two-fold. Firstly it was to assess the suitability for tubal recanalization and factors predicting successful laparoscopic recanalization. Secondly, it was to analyze the fertility outcomes and factors affecting the pregnancy rate following laparoscopic tubal recanalization. Materials and Methods: A retrospective chart review of prospectively followed-up 29 women at a tertiary care center seeking tubal sterilization reversal between May 2005 and February 2010 were included. Results: In 14 (48.3% women unilateral tubes were suitable and in only 3 women (10.3% bilateral tubes were suitable. All cases with laparoscopic tubal sterilization were suitable, whereas all cases with fimbriectomy were unsuitable for recanalization. In 6 (20.7% cases salphingostomy was performed as an alternative procedure to tubal reanastomosis. The overall pregnancy rate was 58.8%. In cases with sterilization by Pomeroy′s method, 4 out of 10 (40% conceived, whereas for laparoscopic tubal ligation cases 6 out of 7 (85.7% conceived (P=0.32. None of the patients with final tubal length <5 cm conceived (P=0.03. Comparing the age at recanalization, in women ≤30 years, 71.4% conceived, as compared with 50% when age of women was more than 30 years (P=0.37. Conclusions: The important factors determining the success of recanalization are technique of sterilization and the remaining length of the tube after recanalization. The gynecologist must use an effective technique of sterilization to minimize the failure rates, but at the same time, which causes minimal trauma, and aim at preserving the length of the tube so that reversal is more likely to be successful, should the patient′s circumstances change.

  15. Device and Container for Reheating and Sterilization

    Science.gov (United States)

    Sastry, Sudhir K.; Heskitt, Brian F.; Jun, Soojin; Marcy, Joseph E.; Mahna, Ritesh

    2012-01-01

    Long-duration space missions require the development of improved foods and novel packages that do not represent a significant disposal issue. In addition, it would also be desirable if rapid heating technologies could be used on Earth as well, to improve food quality during a sterilization process. For this purpose, a package equipped with electrodes was developed that will enable rapid reheating of contents via ohmic heating to serving temperature during space vehicle transit. Further, the package is designed with a resealing feature, which enables the package, once used, to contain and sterilize waste, including human waste for storage prior to jettison during a long-duration mission. Ohmic heating is a technology that has been investigated on and off for over a century. Literature indicates that foods processed by ohmic heating are of superior quality to their conventionally processed counterparts. This is due to the speed and uniformity of ohmic heating, which minimizes exposure of sensitive materials to high temperatures. In principle, the material may be heated rapidly to sterilization conditions, cooled rapidly, and stored. The ohmic heating device herein is incorporated within a package. While this by itself is not novel, a reusable feature also was developed with the intent that waste may be stored and re-sterilized within the packages. These would then serve a useful function after their use in food processing and storage. The enclosure should be designed to minimize mass (and for NASA's purposes, Equivalent System Mass, or ESM), while enabling the sterilization function. It should also be electrically insulating. For this reason, Ultem high-strength, machinable electrical insulator was used.

  16. Cost-effectiveness analysis comparing the essure tubal sterilization procedure and laparoscopic tubal sterilization.

    Science.gov (United States)

    Thiel, John A; Carson, George D

    2008-07-01

    To analyze the financial implications of establishing a hysteroscopic sterilization program using the Essure micro-insert tubal sterilization system in an ambulatory clinic. A retrospective cohort study (Canadian Task Force classification Type II-2), in an ambulatory women's health clinic in a tertiary hospital, of 108 women undergoing Essure coil insertion between 2005 and 2006, and 104 women undergoing laparoscopic tubal sterilization for permanent sterilization between 2001 and 2004. The Essure procedures used a 4 mm single channel operative hysteroscope and conscious sedation (fentanyl and midazolam); the laparoscopic tubal sterilizations were completed under general anaesthesia with a 7 mm laparoscope and either bipolar cautery or Filshie clips. Costs associated with the procedure, follow-up, and management of any complications (including nursing, hospital charges, equipment, and disposables) were tabulated. The Essure coils were successfully placed on the first attempt in 103 of 108 women (95%). Three patients required a second attempt to complete placement and two patients required laparoscopic tubal sterilization after an unsuccessful Essure. All 104 laparoscopic tubals were completed on the first attempt with no complications reported. The total cost for the 108 Essure procedures, including follow-up evaluation, was $138,996 or $1287 per case. The total cost associated with the 104 laparoscopic tubal sterilization procedures was $148,227 or $1398 per case. The incremental cost-effectiveness ratio was $111. The Essure procedure in an ambulatory setting resulted in a statistically significant cost saving of $111 per sterilization procedure. Carrying out the Essure procedure in an ambulatory setting frees space in the operating room for other types of cases, improving access to care for more patients.

  17. 21 CFR 872.6710 - Boiling water sterilizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Boiling water sterilizer. 872.6710 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6710 Boiling water sterilizer. (a) Identification. A boiling water sterilizer is an AC-powered device that consists of a container for boiling water...

  18. 21 CFR 880.6860 - Ethylene oxide gas sterilizer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide gas sterilizer. 880.6860 Section... Miscellaneous Devices § 880.6860 Ethylene oxide gas sterilizer. (a) Identification. An ethylene gas sterilizer is a nonportable device intended for use by a health care provider that uses ethylene oxide (ETO) to...

  19. 9 CFR 116.4 - Sterilization and pasteurization -records.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Sterilization and pasteurization... REPORTS § 116.4 Sterilization and pasteurization -records. Records shall be made by means of automatic... ingredients, equipment, or biological product subjected to sterilization or pasteurization. (Approved by the...

  20. 42 CFR 441.255 - Sterilization by hysterectomy.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Sterilization by hysterectomy. 441.255 Section 441.255 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Sterilizations § 441.255 Sterilization by hysterectomy. (a) FFP is not available in expenditures for a...