Ionizing radiation for sterilization of medical products and biological tissues

Energy Technology Data Exchange (ETDEWEB)

Kumar, S K; Raghevendrarao, M K [Bhabha Atomic Research Centre, Bombay (India). Library and Technical Information Section

1975-10-01

The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products.

Audits of radiation sterilization facilities

International Nuclear Information System (INIS)

Kelkar, Prabhakar M.

2001-01-01

Johnson and Johnson is the world leader in sterilization science and technology. A special group of scientists and technologists are engaged in the development of new methods of sterilization, worldwide monitoring of sterilization processes, equipment and approvals for all types of sterilization processes. Kilmer Conference in the alternate year for the benefit of all those involved in improvement in sterilization science is held. Cobalt-60 gamma radiation for sterilization of medical products on commercial scale is used. This kind of mammoth task can only be achieved through systematic method of planning, auditing, expert review and approval of facilities

Status of radiation sterilization of healthcare products in China

International Nuclear Information System (INIS)

Zhu Nankang; Wang Chunlei; Teng Weifang

2004-01-01

This paper describes the status of 60 Co radiation facilities both in service and under construction in China and examines the future market for radiation sterilization of healthcare products. Policies for developing the industry of radiation sterilization are also put forward; these include implementation of appropriate quality systems, scale-up and merging of existing radiation facilities, development of electron beam radiation for sterilization purposes and increasing awareness of the technology of radiation sterilization

Sewage sterilization through gamma radiation

International Nuclear Information System (INIS)

Vieira, D.V.; Teixeira, W.M.S.; Silva, F.C.A. da

2017-01-01

Lack of sewage treatment and adequate sanitation conditions can contribute to the proliferation of numerous parasitic and infectious diseases in addition to water degradation. Approximately fifty types of infections can be transmitted from a sick to a healthy person through different pathways involving human excreta. Untreated sewage can contaminate water, food, hands, soil, etc. Epidemics of certain diseases such as typhoid, cholera, dysenteries, etc., and countless cases of worms are responsible for high mortality rates in third world countries. In the work the different techniques of sewage treatment by disinfestation and sterilization were analyzed, highlighting the use and the advantages of the gamma radiation as well as the aspects of the radiological protection involved. The technique of sewage sterilization using gamma radiation is a method of controlling bacteria and microorganisms. It is estimated that more than 200 large irradiators are in operation worldwide, of which 5 are in Brazil, for general sterilization use. These facilities use a large amount of radioactive material, in the order of millions of Becquerel, for sterilization with high doses of radiation, which can generate lethal doses in a few minutes. These industrial facilities use Cobalt-60, being classified by the International Atomic Energy Agency - IAEA as Category 1 of high risk, and must possess a high level of radiological protection to carry out the sterilization, standing out the defense in depth. Specific legislation on radiological protection should be drafted for safe work and avoid future radiation accidents

Radiation sterilization of hydrocortisone acetate

International Nuclear Information System (INIS)

Charef, A.; Boussaha, A.

1989-09-01

The feasibility of using high energy ionizing radiation for the sterilization of hydrocortisone acetate was investigated. Hydrocortisone acetate in the form of powder was exposed to different dose levels of gamma radiation using a Cobalt-60 source. The irradiated samples were examined by various physico-chemical techniques in order to detect possible radiolysis products. It was of interest to know if one could insure sterility and retain biological properties of the drug by suitable choice of radiation dose. The results showed that a 10 KGy radiation dose causes no change in the physico-chemical properties of the drug and is sufficient to obtain contaminant-free product

Radiation sterilization of some pharmaceutical preparations and medical products

International Nuclear Information System (INIS)

Tashmetov, M.Yu.; Makhkamov, Sh.M.; Urinov, Sh.S.; Turaev, A.S.; Sultanov, M.S.; Inagomov, Kh.S.

2006-01-01

Full text: In connection with intensive development of pharmacology and medical techniques, use of the products contacting to blood, with the internal environment of an organism, with wound surface, with mucous membranes and skin there were high requirements to sterility of pharmaceutical preparations and medical products. Traditional methods of sterilization (heat treatment, gas processing and processing the ferry) have some restrictions in application, and not insufficient degree of sterilization required for pharmaceutical preparations and medical products. Thermal processing can lead to degradation of structure (medicine), mechanical changes and loss of medical properties. Besides, it is impossible to carry out sterilization of many pharmaceutical preparations by a method of heat treatment. Sterilization of products in packing is very complicated, because sterilization temperature of packing and a product is different. Gas processing is basically applied to sterilization of medical products (syringes, bandage, cotton wools, etc.). However, the degree of sterility is low, because of rather low ability and heterogeneity of sterilizing substance. Sterilization in packing represents special difficulty and demands additional charges related with delivery of the purified gas from abroad. Last years alongside with known technological methods of sterilization of medical products and pharmaceutical preparations radiating methods of processing have found wide application. Use of electronic bunches with the moderate energy and various isotopes became a basis for formation and development of a new direction in the medicine, called by 'radiation sterilization'. The radiation technology is highly harmless and economic, not polluting substance and surrounding space. Unlike the specified traditional methods, radiating processing of products by the isotope 60 Co, radiating the gamma quantum, has unique opportunities - high penetrability in substance, providing uniformity of

Radiation sterilization: an industrial process

International Nuclear Information System (INIS)

Ley, F.J.

1975-01-01

A new dimension has been added to the use of radiation in the medical field with the introduction of radiation as a sterilizing agent. Its use in diagnosis through radioactive tracers or X-rays and in therapy administered with the most sophisticated of electrical machines or radioisotope units, is familiar in the hospital world, being well established therein. In contrast, the application of radiation sterilization is in industry where the installation of large radiation sources is already commonplace in many countries. The beginnings in the early 1950's centered on the Van de Graaff machine and linear accelerators and the pioneering efforts of Ethicon Inc. here in the United States must be recognized. However, although sterilization with electron beams is still current practice in a number of plants, the use of gamma rays from cobalt-60 is preferred. The first steps in this direction were taken by the U.K.A.E.A. which, in common with similar organizations elsewhere, was attempting to exploit the tremendous potential for cobalt-60 production arising through the rapid construction of nuclear reactors. The first full-scale commercial gamma plant was commissioned in the U.K. in 1960. It reached a loading of 500,000 curies before its demolition after twelve years of operation. The process gained rapid acceptance within industry and approval by health authorities because it provided a ''cold'' sterilization method combining the property of lethal effect with penetration. Its immediate impact occurred in the introduction of disposable products making it possible, for example, to use heat-labile plastics and new packaging materials and package designs. Certainly, the technique has proved complementary to sterilization methods based on heat and to the use of chemical agents, in particular ethylene oxide gas

Sterilization by ionizing radiation comparative evaluation

International Nuclear Information System (INIS)

Tata, A.; 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 7 on 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

Radiation sterilization facility for melon fly

International Nuclear Information System (INIS)

Danno, A.

1985-01-01

The melon fly (Dacus cucurbitae Coquillett) has been observed in Amami Island since l975. Kagoshima Prefecture has had a melon fly eradication project underway since 1979. A mass-fearing facility and a radiation sterilization facility were constructed in Naze in March of l98l. In the early stages of the project, sterile insects were produced at the rate of 4 x l0/sup 6/ pupae/week. In the later stages, the activity of the project was enlarged by tenfold. The conditions for design of the radiation sterilization facility, which has been developed with a central control system for automated irradiation, are examined from an engineering standpoint

Radiation: A means of sterilization

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, R N [International Atomic Energy Agency, Division of Life Sciences, Radiation Biology Section, Vienna (Austria)

1975-12-15

The sterilization of medical products by ionizing radiation is a well-established industrial process in a number of technologically advanced countries. It is indeed encouraging to note the rate of growth experienced during the past fifteen years. Starting with the first commercial plant in the early sixties in the USA there are to date more than sixty large facilities of this kind located in USA, Canada, Australia and the countries of Europe including USSR. The geographical distribution of these sterilization plants is rather unbalanced. In this respect Europe is far ahead of the other continents of the world, with about 65% of all sterilization plants, followed by North and South America with 17%, Asia with 8%, Australia and New Zealand with 9% and Africa with only 1%. During the last 10 years the IAEA has actively contributed to the development of radiation sterilization practices and technology in the Member States, with particular emphasis on the developing countries. Such promotional efforts have been made by (a) supporting co-ordinated research to accumulate relevant technical information, (b) organizing scientific meetings and training courses, (c) providing technical expertise in the form of fellowships and expert services, (d) providing technical assistance to conduct market surveys and economic feasibility assessment, (e) scientific publications, including technical manuals and proceedings reports, and (f) assistance in the formulation of an international 'Code of Practice' for standardization of the manufacturing practices for radiation sterilized medical products to meet the specified requirements of the various national Pharmacopoeias and of the international consumer market.

Radiation sterilization of skin allograft

International Nuclear Information System (INIS)

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

2009-01-01

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.

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.

Research on industrial development of radiation sterilization in Sichuan

International Nuclear Information System (INIS)

Chen Xun; Zhu Rong; Chen Jigang; Ouyang Qiongli

2010-01-01

Radiation sterilization is widely applied in food processing, pharmaceutical manufacturing and medical instrumentation producing. As this industry offers service to related corporations, its development depends largely on the market scale of the relevant industries. This article mainly discusses the balance point between the capacity of radiation sterilization and the requirement of its market. There are less than 1% of the companies in Sichuan which using radiation sterilization for its products, broad prospects has shown in this field. There are 3 key points to make its output value reach 0.1% of the GDP in Sichuan: 1. Breaking the restrictions of capacity and inappropriate resources distribution. 2. Promoting the technique of radiation sterilization, guiding corporation to reduce their dependence on food additive from the perspective of food safety, make effective implantation of radiation sterilization into their manufacture processes. 3. Increasing publicity, eliminating scared mentality among customer on nuclear technology, helping manufacturing corporations to establish green environmental protection brand, directing our customer to a more healthy awareness. (authors)

International Standards for Radiation Sterilization of Medical Devices

International Nuclear Information System (INIS)

Miller, A.

2007-01-01

For a terminally sterilized medical device to be designated '' STERILE '', probability of finding the viable micro-organisms in the device shall be equal to or less than 1 x 10 -6 (EN 556-1:2001: Sterilization of medical devices - Requirements for medical devices to be designated '' STERILE '' - Part 1: Requirements for terminally sterilized medical devices). Author presents the main legal aspects of the international standards for radiation sterilization of medical devices

Sterilization of health care products - Radiation. Part 2: Establishing the sterilization dose

International Nuclear Information System (INIS)

2006-01-01

This part of ISO 11137 describes methods that may be used to establish the sterilization dose in accordance with one of the two approaches specified in 8.2 of ISO 11137-1:2006. The methods used in these approaches are: a) dose setting to obtain a product-specific dose; b) dose substantiation to verify a preselected dose of 25 kGy or 15 kGy. The basis of the dose setting methods described in this part of ISO 11137 (Methods 1 and 2) owe much to the ideas first propounded by Tallentire (Tallentire, 1973 [17]; Tallentire, Dwyer and Ley, 1971 [18]; Tallentire and Khan, 1978 [19]). Subsequently, standardized protocols were developed (Davis et al., 1981 [8]; Davis, Strawderman and Whitby, 1984 [9]) which formed the basis of the dose setting methods detailed in the AAMI Recommended Practice for Sterilization by Gamma Radiation (AAMI 1984, 1991 [4], [6]). Methods 1 and 2 and the associated sterilization dose audit procedures use data derived from the inactivation of the microbial population in its natural state on product. The methods are based on a probability model for the inactivation of microbial populations. The probability model, as applied to bioburden made up of a mixture of various microbial species, assumes that each such species has its own unique D 10 value. In the model, the probability that an item will possess a surviving microorganism after exposure to a given dose of radiation is defined in terms of the initial number of microorganisms on the item prior to irradiation and the D 10 values of the microorganisms. The methods involve performance of tests of sterility on product items that have received doses of radiation lower than the sterilization dose. The outcome of these tests is used to predict the dose needed to achieve a predetermined sterility assurance level, SAL. Methods 1 and 2 may also be used to substantiate 25 kGy if, on performing a dose setting exercise, the derived sterilization dose for an SAL of 10 -6 is u ≤25 kGy. The basis of the method

A research on industrial development of radiation sterilization in Sichuan

International Nuclear Information System (INIS)

Chen Xun; Zhu Rong; Chen Jigang

2010-01-01

Radiation sterilization is widely applied in food processing, Pharmaceutical Manufacturing and medical instrumentation producing. As this industry offers service to related corporations, its development depends largely on the market scale of the relevant industries. This article mainly discusses the balance point between the capacity of radiation sterilization and the requirement of its market. There are less than 1% of the companies in Sichuan which using radiation sterilization for its products, broad prospects has shown in this field. The output value of radiation sterilization industry reached 0.1% of the GDP in some advanced countries (America and Japan...), under this standard, its output value in Sichuan province would be RMB1.2 hundred million, but now our capacity and scale of this industry is less than RMB40million.Research shows: there are 3 key points to make its output value reach 0.1% of the GDP in Sichuan: 1. Breaking the 'bottleneck' restrictions of capacity and Inappropriate resources distribution. 2. Promoting the technique of radiation sterilization, guiding corporation to reduce their dependence on food additive from the perspective of food safety, make effective implantation of radiation sterilization into their manufacture processes. 3. Increasing publicity for radiation sterilization, eliminating scared mentality among customer on nuclear technology, helping manufacturing corporations to establish green environmental protection brand, directing our customer to a more healthy awareness. (authors)

Practices of radiation sterilization of medical products and pharmaceutical preparations: egyptian experience

International Nuclear Information System (INIS)

Roushdy, H.M.

1992-01-01

Radiation sterilization involves the application of sufficient ionizing energy furnished by either x-rays, gamma-rays or accelerated electron beams, to render an article free of viable micro-organisms. The method offers a number of advantages which makes it an attractive choice in a number of situations: It is a suitable means of sterilizing many many materials.. Radiation causes no significant temperature rise, thus permits sterilization of heat-sensitive drugs and low melting-point plastics. It is certainly the best, and often the only method of sterilizing biological tissues and preparations of biological origin. due to its high penetrating ability, gamma-radiation reaches all parts of the object to be sterilized. The radiation sterilized products are not subjected to touching or exposure to the outside environment except by the and users. The chemical reactivity of radiation is relatively low as compared with the highly reactive gases. Radiation can be easily adapted for continuous processing as compared with batch operations currently in use with gas sterilization. The radiation process is the most reliable of all competing sterilization methods due to the obsolete certainty that the radiation source emits radiation of known energy and power

Practices of radiation sterilization of medical products and pharmaceutical preparations: egyptian experience

Energy Technology Data Exchange (ETDEWEB)

Roushdy, H M

1993-12-31

Radiation sterilization involves the application of sufficient ionizing energy furnished by either x-rays, gamma-rays or accelerated electron beams, to render an article free of viable micro-organisms. The method offers a number of advantages which makes it an attractive choice in a number of situations: It is a suitable means of sterilizing many many materials.. Radiation causes no significant temperature rise, thus permits sterilization of heat-sensitive drugs and low melting-point plastics. It is certainly the best, and often the only method of sterilizing biological tissues and preparations of biological origin. due to its high penetrating ability, gamma-radiation reaches all parts of the object to be sterilized. The radiation sterilized products are not subjected to touching or exposure to the outside environment except by the and users. The chemical reactivity of radiation is relatively low as compared with the highly reactive gases. Radiation can be easily adapted for continuous processing as compared with batch operations currently in use with gas sterilization. The radiation process is the most reliable of all competing sterilization methods due to the obsolete certainty that the radiation source emits radiation of known energy and power.

Radiation Sterilization of Two Commonly Culture Media Used for Bacterial Growth

International Nuclear Information System (INIS)

El-Hifnawi, H.N.

2008-01-01

Radiation sterilization of culture media used for the cultivation of bacteria by Co-60 gamma ray was investigated. Nutrient agar and tryptone glucose yeast extract (TGY) media widely used for the propagation of bacteria were sterilized with 15 kGy dose gamma radiation. Seven different bacterial species were grown as well on the radiation sterilized media as on media sterilized by autoclaving in a conventional way

Radiation sterilization of traditional medicine drugs in Vietnam

International Nuclear Information System (INIS)

Hang, N.D.; Canh, T.T.; Thuy, T.T.

1995-01-01

With the application of Gamma Co-60 radiation sterilization in pharmaceutical industry, attention should be paid to the possibilities of sterilizing traditional medicine drugs produced in Vietnam. In this paper the opinion which traditional medicine drugs can be satisfactorily sterilized by irradiation is based on the changes of physical and chemical properties of the products and microbiological examinations. The sterilizing radiation dose were calculated and the results are the following (in Mrad) Rheumatine-2.2, Hasinh-3.3, snake extract-1.8, Samcotgiao-2.2. The changes of physical and chemical properties of the products and their toxicity after irradiation have been shown to be not over the levels of allowance. (Author)

Radiation sterilization of traditional medicine drugs in Vietnam

Energy Technology Data Exchange (ETDEWEB)

Hang, N.D.; Canh, T.T.; Thuy, T.T. [Nuclear Research Inst., Da Lat (Viet Nam)

1995-10-01

With the application of Gamma Co-60 radiation sterilization in pharmaceutical industry, attention should be paid to the possibilities of sterilizing traditional medicine drugs produced in Vietnam. In this paper the opinion which traditional medicine drugs can be satisfactorily sterilized by irradiation is based on the changes of physical and chemical properties of the products and microbiological examinations. The sterilizing radiation dose were calculated and the results are the following (in Mrad) Rheumatine-2.2, Hasinh-3.3, snake extract-1.8, Samcotgiao-2.2. The changes of physical and chemical properties of the products and their toxicity after irradiation have been shown to be not over the levels of allowance. (Author).

9. School of radiation sterilization and hygienization - Lectures

International Nuclear Information System (INIS)

Zimek, Z.; Kaluska, I.; Gluszewski, W.

2007-01-01

During the 9 School of radiation sterilization and hygienization 23 lectures were presented. They were devoted to all aspects of sterilization and hygienization of food, medicinal articles and cosmetics using the ionisation radiation. It was destined to physicians, manufacturers and vendees of spices, pharmaceuticals and cosmetics, personnel of the sanitary-epidemiological stations and even for the art conservators

9. School of radiation sterilization and hygienization - Presentations

International Nuclear Information System (INIS)

Zimek, Z.; Kaluska, I.; Gluszewski, W.

2007-01-01

During the 9. School of radiation sterilization and hygienization 23 lectures were presented. They were devoted to all aspects of sterilization and hygienization of food, medicinal articles and cosmetics using the ionisation radiation. It was destined to physicians, manufacturers and vendees of spices, pharmaceuticals and cosmetics, personnel of the sanitary-epidemiological stations and even for the art conservators

Radiation sterilization of pharmaceuticals and polymers

International Nuclear Information System (INIS)

Gopal, N.G.S.

1978-01-01

Radiation, in the form of high energy electrons as well as gamma radiation, has featured in the last 15 yr as a promising sterilization agent for many heat sensitive and ethylene oxide incompatible pharmaceuticals and polymers of medical usage. This article deals with (i) a comparison of the various methods of sterilization and their shortcomings, (ii) modes of interaction of radiation with matter, (iii) the types of radiation sources in common use, (iv) dosimetry, (v) dose rate effect, (vi) a literature survey of the radiation effect on pharmaceuticals in solid form as well as in aqueous solution and on polymers in the form of plastic medical products and (vii) the evaluation of the irradiated products. The effect of dose rate on the stability of these materials is emphasized. Either very little work has been done on the dose rate effect or the published information is scanty. The literature survey covers the recent period of 5 to 6 years. (author)

Update application and development of radiation sterilization technology on pharmacy eutical industry

International Nuclear Information System (INIS)

Zhao Yongfu; Nanjing Univ., Nanjing; Wang Changbao; Wang Chao

2006-01-01

Since 'Standard of Radiation Sterilization by 60 Co Irradiator on Chinese Medicine' has been cleared, radiation sterilization technology obtains the widespread application on pharmacy. In this paper, the newest application and development of this technology on pharmacy are introduced from several aspects, such as dose control, drugs packing, the influence of radiation on functional ingredients and so on. Aimed at the current problem of radiation sterilization on pharmacy of our country, concrete measure is proposed. And the application of radiation sterilization on health food, enzyme preparation and controlled-release capsule is specially introduced. (authors)

Sensitivity of viruses to radiation sterilization

International Nuclear Information System (INIS)

Dziedzic Goclawska; A

1999-01-01

The hazard of infectious disease transmission with tissue allografts is a major concern in tissue banking practice. Microorganisms can be introduced into grafts during tissue collection, processing and storage, but even when all these procedures are performed under a septic conditions, the possibility of fungal, bacterial or viral disease transmission of donor origin can not be excluded. Therefore, in order to minimize the risk of infectious disease transmission, several steps should be undertaken, including a careful donor screening, proper tissue processing and sterilization of tissue allografts. The risk of transmission of viral infections such as hepatitis B, C, other viruses and particularly HIV with tissue allografts is of great significance and the search for sterilizing methods which inactivate and/or highly reduce viral infectivity continues. Sterilization of tissue allografts with ionizing radiation (introduced in the mid of 1950s) is increasingly used in tissue banking practice. The effectiveness of the radiation-sterilization procedure depends on the amount of energy transferred, the number of contaminating microorganisms and their resistance to ionizing radiation (initial contamination, bioburden). Usually, spores are more resistant than vegetative forms of bacteria, some fungi may be as resistant as bacterial spores, and viruses are, in general, more resistant than bacteria. Dita concerning effectiveness of ionizing radiation to inactivate viruses (e.g. such as HBV, HCV or HIV) in tissue allografts collected from cadavers are scarce. It has been found that the dose of irradiation needed to reduce HIV load by I log10 unit (D10) is about 4.0 kGy or even 5.6 kGy. The level of infectious HIV in plasma is usually evaluated by titration of tissue culture infective dose (TCID50/ml). Taking into consideration the recommended sterility assurance level (SAL) 10-6, assuming the HIV bioburden to be 103 TCID50/ml for the state of acute infection and D10 value of 4

Cleanup of TMI-2 demineralizer resins

International Nuclear Information System (INIS)

Bond, W.D.; King, L.J.; Knauer, J.B.; Hofstetter, K.J.; Thompson, J.D.

1985-01-01

Radiocesium is being removed from Demineralizers A and B (DA and DB by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). The process was also required to limit the maximum cesium activities in the resin eluates (SDS feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consists of 17 stages of batch elution. In the initial stage, the resin is contacted with 0.18 M boric acid. Subsequent stages subject the resin to increasing concentrations of sodium in NaH 2 BO 3 -H 3 BO 3 solution (total B = 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared to those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2 which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB

Proposed Philippine radiation-sterilization plant, and a survey of market potential

International Nuclear Information System (INIS)

Singson, C.C.; Ibe, L.D.

1975-01-01

The paper deals with a study to assess the market potential of radiation sterilization in the Philippines. A market survey conducted with the technical assistance of an IAEA expert from India shows that most of the pharmaceutical industries engaged in the manufacture of medical products unanimously agree that there is an urgent need for a centralized radiation sterilization plant to meet the demands of sterilization of most of their products and packaging materials. The authorities of the government and some of the private hospitals surveyed are also very keen for the establishment of a sterilization facility since most modern medical products and devices are made of heat-sensitive thermoplastics which cannot be heat or steam sterilized. Availability of sterile products will help improve the public health standards of the population. The scope of the utilization of a radiation-sterilization facility in Diliman Quezon City is also discussed. (author)

Radiation sterilization of medical products- current trends and future prospects

International Nuclear Information System (INIS)

Sharma, G.

1997-01-01

In medical practice use of sterile pharmaceuticals and single use disposable medical devices is steadily increasing. Sterile pharmaceuticals like injections and ophthalmic ointments are required for therapy. Medical devices are employed for diagnostic, drug administration or corrective purposes, and as implants for temporary, short term or long term residence in the human system. All these products are made available in sterile form by treating them to a suitable process of sterilization i.e. dry/wet heat, ethylene oxide (EtO) gas or ionizing radiation. In this paper current trends and future prospects of radiation sterilization of medical products are given in detail. 9 refs., 7 tabs

Study on blood compatibility of the radiation sterilized disposable burette transfusion apparatus

International Nuclear Information System (INIS)

Chen Guochong; Liu Wen; Liu Qingfang

2011-01-01

The blood compatibility of the radiation sterilized disposable burette transfusion apparatus was investigated to provide evidence for the safety of radiation sterilized medical devices. The initial bacteria burden of the disposable burette transfusion apparatus was examined according to the ISO11737 standard, and the whole blood clotting time, prothrombin time, partial thromboplastin time and hemolysis rate of the samples were determined. There was no significant difference between the radiation sterilized samples and negative controls on WBCT, PT and PTT (p>0.05). Haemolysis test showed that the haemolysis rate of the sample sterilized by irradiation was 1.38%, which was coincidence with the criteria of the medical devices. After sterilization by irradiation, disposable burette transfusion apparatus show good blood compatibility, which could be considered that radiation sterilization is a biologically safe method for the medical apparatus. (authors)

Sterilization techniques without heating (ultraviolet ray, radiation and ozone)

International Nuclear Information System (INIS)

Ito, Hitoshi

1991-01-01

The recent demand of consumers for processed foods is characterized by the intention for health and nature, besides, the demand for low sweetness, salt reduction, no additive and freshness becomes strong. In view of the control of microorganisms in products, all these become the negative factors. Accordingly, in order to overcome them, it is urgently desired to develop new technology or to improve conventional methods. As to heating sterilization, the uniform temperature treatment to the inside of foods is difficult, and it cannot be applied to perishables. The high temperature sterilization above 120degC causes the change in nutrition composition and physical properties. Ultraviolet ray and ozone can be used for the sterilization of food surface and powder and liquid foods. Radiation treatment can be applied to packed foods and frozen foods as well as food surface. The principle and the fields of application of ultraviolet ray sterilization, radiation sterilization and ozone sterilization are reported. In the mechanism of these methods, the action to DNA and oxidation are common. (K.I.)

Radiation sterilization of polymeric implant materials

International Nuclear Information System (INIS)

Bruck, S.D.; Mueller, E.P.

1988-01-01

High-energy irradiation sterilization of medical devices and implants composed of polymeric biomaterials that are in contact with tissue and/or blood, may adversely affect their long-term mechanical and/or biological performance (tissue and/or blood compatibility). Since many polymeric implants may contain trace quantities of catalysts and/or other additives, the effect of high-energy radiation on these additives, and possible synergistic effects with the polymer chains under the influence of high-energy radiation, must be considered. It is essential to indicate whether polymeric implants are used in short-term (acute) or long-term (chronic) applications. Relatively small changes in their physicochemical, mechanical, and biological properties may be tolerable in the short term, whereas similar changes may lead to catastrophic failures in long-term applications. Therefore, polymeric implants which are to be sterilized by high-energy irradiation should be carefully evaluated for long-term property changes which may be induced by the radiation

Investigation of radiation gamma-sterilization effect on sodium alginate hydrogels

International Nuclear Information System (INIS)

Valueva, M.I.; Oltarzhevskaya, N.D.; Maksimova, Yu.S.; Fenin, A.A.

2012-01-01

The effect of gamma-radiation in doses ensuring materials sterility (6-15 kGy) on alginate hydrogels is studied. For conservation of polymer solutions viscosity after sterilization it is necessary to introduce in polymer matrix different additives inhibiting the radiolysis process. Substances-antioxidants (aqueous extracts of sea-buckthorn and blueberry), polyvinylpyrrolidone, pectin, polyethylene oxides with molecular mass from 400 to 40000 have been studied as the additives. The additives selected have the positive effect on the result of alginate hydrogels sterilization. It is established, that the problem of human tissue radiation protection is closely connected with the problem of biopolymer hydrogels radiation protection [ru

Comparative mating and reproductive performance of radiation sterilized and radiation induced F1 sterile males of Earias vittella (Fabricius)

International Nuclear Information System (INIS)

Shantharam, K.; Tamhankar, A.J.; Harwalkar, M.R.

1995-01-01

Studies were conducted on mating behaviour and reproductive performance of a) Earias vittella (F.) males rendered sterile by exposing them to 300 Gy gamma rays and b) F 1 sterile males obtained by exposing parent male to 100 Gy gamma rays. For the study, males were allowed only one mating with a normal female. Results revealed that premating period, period in copula and per cent insects mating were not adversely affected in case of both types of sterile males and fecundity also remained unaffected. However, in both types of sterile males, incidence of spermatophore transfer without sperm was very large and such an occurrence (including reduced spermatophore transfer) was significantly higher in case of radiation sterilized males compared to the F 1 sterile males. Inability to produce and transfer spermatophore and/or sperm appeared to be a major cause behind the reduced mating competitiveness of both types of males. (author). 22 refs., 2 tabs

Prospects for radiation sterilization of medical products in Egypt

International Nuclear Information System (INIS)

Roushdy, H.M.

1975-01-01

The pharmaceutical industry in Egypt is continually expanding its activity and each year marks new accomplishments and additions which enable the companies to apply the most modern scientific means in the production of pharmaceutical preparations and consequently to improve their market potentialities. The certainty of expansion and the possibility of increasing exports of sterilized medical products, particularly to Arab and African countries, indicate a need for a gamma-sterilization plant. This technology permits the introduction of the latest practices with regard to used disposables, thus greatly reducing the chances of cross-contamination which usually results in serious complications enhanced by local environmental conditions. This paper reviews the current state and future prospects for radiation sterilization of medical products and biological tissues in connection with other related industrial radiation processings. Moreover, the paper reviews the Egyptian scientific and technical experience with irradiation facilities and the parameters underlying the choice of Egypt's first industrial gamma and electron-beam irradiators designed for more than a single-purpose use, with hygienic measures taken to avoid biological contamination of sterilized medical packages throughout the sterilization process. In addition, the paper deals with the policy set up for establishing the Egyptian National Centre for Radiation Technology with a view to introducing irradiation techniques in the sterilization of medical products, and to improving the properties and increasing the competitiveness of Egyptian fabrics. Apart from medical sterilization, certain industrial processes have been mentioned to show how a multi-purpose irradiation facility may be utilized in a developing country to justify significantly the large investment required. (author)

Economical aspects of radiation sterilization with electron beam

International Nuclear Information System (INIS)

Zimek, Z.; Kaluska, I.

1998-01-01

Radiation sterilization has been introduced in Poland in the early seventies. Since then continuous progress is observed in quantity of sterilized products. The commercial irradiation facility was built in 1993 to fulfill growing demands for radiation service. The real costs of running this plant were shown. The share of the cost of investment and the cost of maintenance and spare parts in accelerator exploitation, as well as the cost of one hour accelerator exploitation against time of one year accelerator exploitation were taken into account

Radiation sterilization of pharmaceuticals and biomedical products

International Nuclear Information System (INIS)

Blackburn, R.; Iddon, B.; Moore, J.S.; Phillips, G.O.; Power, D.M.; Woodward, T.W.

1975-01-01

Sterilization of pharmaceuticals by radiation is accompanied by chemical degradation which must be eliminated or minimised if the method is to be successfully applied. In order to devise ways in which the pharmaceutical can be protected it is necessary to know the yield and nature of the decomposition products, the mechanisms by which degradation occurs, and the rate constants for the reactions involved. We have obtained such data for a variety of pharmaceutical compounds, viz. vitamin B12, benzyl penicillin, sulphonamides, indoles, heparin, alginates and phenylmercurics, both in the solid state and in aqueous solution. The scope and limitations of radiation sterilization are discussed in the light of these results. (author)

Radiation sterilization of pharmaceuticals (eg chloramphenicol)

International Nuclear Information System (INIS)

Zeegers, F.; Tilquin, B.

1991-01-01

In connection with the ongoing world-wide application of irradiation as a new technology for sterilization, the identification of the drugs products is very important. Introduction of radiosterilization of pharmaceuticals is proceeding at a slower rate than that for disposable medical supplies; it is the responsibility of the manufacturer to prove that degradation of products is safe. Major advantages in the use of radiation as a sterilization procedure are high penetrating power, small temperature rise, ease of control and minimal degradation of irradiated solid drugs [fr

Radiation sterilization of animal farm sewage

International Nuclear Information System (INIS)

Rosiak, J.; Perkowski, J.; Pekala, W.

1984-01-01

Influence of irradiation on organisms appearing in farm sewage has been discussed. Practical examples of employing the radiation to sterilization of municipal wastes and liquid sewage from the industrial swine farms have been presented. (author)

Ionization radiation in sterilization of the tissue transplants

International Nuclear Information System (INIS)

Uhrynowska-Tyszkiewicz, I.; Kaminski, A.

2007-01-01

Established in 1963, the Central Tissue Bank in Warsaw is a multi-tissue bank located in the Department of Transplantology of the Medical University in Warsaw. Allografts such as bone, cartilage, tendons, ligaments, sclera, skin and amnion are preserved mainly by deep-freezing and/or lyophilization and subsequently radiation-sterilized with a dose of 35 kGy with gamma rays in a 60 Co source (at the Institute of Applied Radiation Chemistry in Lodz) or with electron beam 10 MeV accelerator (at the Institute of Nuclear Chemistry and Technology in Warsaw). This is the oldest working tissue bank in the world, which for almost 40 years now has routinely used ionizing radiation for sterilization of tissue allografts

A review: radiation sterilization of pharmaceuticals

International Nuclear Information System (INIS)

Jacobs, G.P.

1985-01-01

The literature on the effects of γ-radiation on drugs, relevant to their sterilization or decontamination, is reviewed. This literature survey essentially covers the past 7 yr, although relevant reports not covered in previous reviews have been included. (author)

Radiation sterilization of plastic packing materials and aseptic packaging

International Nuclear Information System (INIS)

Tokuoka, Keiko

1986-01-01

In the present day of 'satiation', quality, not quantity, is emphasized for foods, the consumers being oriented toward raw and healthy foodstuff. Aseptic Packaging is excellent means of conservation. While conventionally chemicals have been used for sterilization of packing materials for aseptic packaging, the sterilization by radiation is used in part recently. The following are described : history of aseptic packaging and its features, sterilization by radiation, γ-ray sterilization of large-sized containers, the development of an aseptic packaging system using electron rays, the occurrence of offensive odors from packing materials (comparison of odors from various materials, volatile substances occurring in irradiated polyethylene, influence of film grade upon the formation of carboxylic acid, influence of the irradiation conditions upon the occurrences of volatile substances, volatile substances occurring in the irradiation of bag-in-box packing materials), changes in properties of the packing materials. (Mori, K.)

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.

Radiation sterilization of triple sugar iron agar

International Nuclear Information System (INIS)

Altmann, G.; Eisenberg, E.; Bogokowsky, B.

1979-01-01

Triple sugar iron agar (TSI), a medium used for the identification of enteric bacteria, was sterilized by gamma radiation using radiation doses of 750-2000 krad. The radio-sterilized medium, slightly modified by increasing its Phenol Red content, performed well when tested with different enterobacteriaceae and other gram negative bacteria. Growth, change of indicator reaction in slant and butt and formation of gas and H 2 S were equal in irradiated and autoclaved TSI. Slants of irradiated TSI in stoppered plastic tubes kept their diagnostic properties during storage for at least 4 months. Gamma irradiation appears to be an attractive and economical method of sterilising nutrient media in sealed tubes or other containers, avoiding the risk of contamination during processing. (author)

Gamma radiations an effective way of monoclonal antibodies sterilization

International Nuclear Information System (INIS)

Lenay Barrera Barroso, Lenay; Otero Abreu, Isabel; Rodriguez Napoles, Dania; Bulte Ocanna, Dubhe; Caballero, Idania

2006-01-01

The sterilization for radiations of pharmaceutical products is an effective, sure and reliable procedure; that it have been proving technically and grateful for different pharmacopoeia. The Monoclonal Antibodies (Acm) produced in the Center of Molecular Immunology (CIM) are products parenteral for the one which results indispensable that they complete the requirements of established sterility. The radio sterilization result the method more recommend for the sterilization of the Acm deep drying, due to the contained first floor of humidity remnant that minimizes the formation of sub-product that they affect their properties. With the objective of proposing a good dose of irradiation for the sterilization, we were carried out a study of the radius sensibility so much of the product like of the polluting of greater frequency of isolation of the clean area of the CIM. The characterization of the radius sensibility of the different micro- organisms was determined by D 10 characteristic of each isolated strains. From the developed studies the Gram-positive rods endospore-forming were the most resistant strains at the deep drying, the radiations and they were of the greater frequency of apparition in the carried out isolations. We could conclude that utilizing a dose of 10 kGy it is possible to eliminate of the pollution more radio resistant, assuring the sterility required in the product, and without inducing effects under desire radiolytic in the same

Radiation sterilization of pharmaceuticals: An overview of the literature

International Nuclear Information System (INIS)

Razem, D.

2008-01-01

Radiation sterilization of pharmaceuticals has never stopped attracting the attention of researchers. In this first as yet unfinished decade of the twenty-first century, the number of relevant papers seems to be on the rise again. In developing radiation sterilization of pharmaceuticals and searching for innovative applications, it is important to understand the end users, i.e. the pharmaceutical and medical professions. Mutual understanding between professions has already resulted in a plethora of products for enhancing, preserving and curing health, and many more are waiting to be discovered

Pharmaceutical aerosols. Study of their gamma radiation sterilization

International Nuclear Information System (INIS)

Sebert, P.

1984-10-01

The gamma radiation sterilization of pharmaceutical aerosols was studied. The following topics were investigated: radiosterilization of nitrogen protoxide used as a propellant; radiosterilization of packaging materials (aluminium containers, plastics valves); radio-sterilization of excipients and active ingredients. Most of the investigated materials proved to be stable to irradiation (2,5 Mrads) from pharmacopoeial aspect. Stability tests of the preparations packaged showed no change in the parameters investigated [fr

Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

International Nuclear Information System (INIS)

Singh, Durgeshwer; Singh, Rita

2012-01-01

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 (p 2 /24 h at 24 h. Gamma irradiation at 25 kGy was found suitable for sterilization 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. - Highlight: ► Use of gamma radiation for sterilization of papain wound dressing was studied. ► Fluid handling and antimicrobial properties of irradiated dressings was evaluated. ► Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings.

The radiation-sterilization of semi-synthetic penicillins

International Nuclear Information System (INIS)

Jacobs, G.P.

1979-01-01

Gamma-irradiation in the dry state of the semi-synthetic penicillins, amoxycillin trihydrate, flucloxacillin-Na, methicillin-Na results in minimal degradation even following a 5 Mrad dose, suggesting the feasibility of their radiation-sterilization. Carbenicillin-Na is more susceptible to radiation-induced degradation but is nevertheless not affected by 1 Mrad dose. This 'low' dose may be suitable for carbenicillin with very low initial contamination. (author)

Radiation sterilization of the greenhouse white fly (Trialeurodes vaporariorum Westw., Homoptera, Aleyrodidae). Part 2

International Nuclear Information System (INIS)

Genchev, N.

1987-01-01

Results are reported of studies of the sterilizing effect on puparia and imagoes of the greenhouse white fly (T. vaporariorum). The irradiation was made by gamma rays at the rate of 12+-5% rad/s. The parameters of radiation-induced sterility were sex determined. The sterilizing effect was expressed in emergence of dominant lethal mutations in spermatozoa accompanied by partial sperm inactivation and of partial aspermia. The absolute sterilizing doses for the two ontogenetic stage are 6 and 7 krad respectively. Radiation induced sterilization of the male parent resulted in forced arrhenotoky in F 1 and was regarded as a transformation of parthogenesis factor necessary for the normal propagation in the insect process into one that is lethal to the population factor. Radiation induced female sterility in females was expressed in the emergence of dominant lethals in oocytes. The absolute sterilizing doses for the puparium and the imago were 5 and 6 krad, respectively. Doses ≥4 krad caused partial infertility

The nutritonal value of protein in radiation sterilized fish meal

International Nuclear Information System (INIS)

Harmuth-Hoene, A.E.; Partmann, W.

1976-01-01

Investigations of four samples of fish flour from various countries which had been sterilized by radiation (5 Mrad) did not show any evidence of radiation-induced changes in crude protein content as well as protein digestibility by enzymatic hydrolysis. Of the 16 amino acids studied only serine suffered a mean loss of 16% while the remaining amino acids showed only slight changes after irradiation. In all four samples we noticed a mean loss of 9% in available lysine. The sterilization of fish flour by irradiation does not diminish the nutritional value of fish protein to any significant extent and, should be given preference over sterilization by heat which reduces the protein quality of fumigation by heat which leaves residues. (orig.) [de

Radiation sterilization of medical products in the Philippines

Science.gov (United States)

Singson, C.; Carmona, C.; de Guzman, Z.; Barrun, W.; Lanuza, L.

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. Hence, the materials used were directly obtained from local manufacturers. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. These studies indicated that radiation sterilization is technically feasible for locally manufactured medical products.

Sterilization of Helicoverpa armigera (hubner) moth (lepidoptera; Noctudae) by using Gamma rays radiation

International Nuclear Information System (INIS)

Subiyakto; Wari D Astati; Sunarto Dwi A

1998-01-01

This experiment was conducted at the Radiation Facility, National Atomic Energy, Jakarta and Entomology Laboratory of the Research Institute for Tobacco and Crops Malang in 1991. Sterilization of moth by radiating insect on pupae stage. The dosage were 0 (unradiated), 1,3,5,7,9,11,13,and 15 krad. The treatments were arranged in complete randomized design with three replications. Each treatments were made variation of copulation (1) two females radiated with a make unradiated (2) two females unradiated with a male radiated, and (3) two females radiated with a male radiated. The results showed that sub sterile dosage (LD 50 ) for male was 0.94 krad and 7.02 krad for female. The sterile dosage (LD 95 ) for male was 10.85 krad and 14.35 krad for female. Research of the competition for copulation between the male radiated and unradiated is needed. (author)

Coordinated research project on radiation sterilization and decontamination of pharmaceuticals and pharmaceutical raw materials. CRP report

International Nuclear Information System (INIS)

2005-01-01

Radiation processing is a very convenient tool for imparting desirable effects in materials and it has been an area of enormous interest in the last few decades. Radiation processing of synthetic and natural polymers for improving their characteristics is largely used in laboratory and industrial scale. Radiation sterilization is a well developed and established technology for many products. It is especially useful for the treatment of pharmaceuticals due to flexibility of radiation processing to be carried out at any desired temperature, sterilizability of mixed products in kits, offering simultaneous sterilization and modification of polymer based formulations. The success of radiation technology for processing of synthetic and natural polymers and treatment of pharmaceuticals has been based, to a large extent, on empirical knowledge. But now, the applications of natural polymers are being sought in knowledge-demanding areas such as pharmacy and biotechnology. Reliable analytical methods are being developed for controlling of degradation effects of radiation on polymers. Procedures and chemical formulations are being investigated enhancing or preventing degradation effects depending on the desired application of the process. The Coordinated Research Project (CRP) on the use of radiation processing for sterilization or decontamination of pharmaceuticals and pharmaceutical raw materials has been completed in 2002. The overall objective of the CRP was to coordinate the research and development programmes carried out in different countries in use of radiation processing for sterilization or decontamination of pharmaceuticals and pharmaceutic raw materials. It has been concluded that in addition to well known advantages of radiation sterilization being a well developed and established technology requiring the control of only one parameter, dose, to achieve sterilization; it is especially useful for the treatment of pharmaceuticals due to flexibility of radiation

Coordinated research project on radiation sterilization and decontamination of pharmaceuticals and pharmaceutical raw materials. CRP report

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

Radiation processing is a very convenient tool for imparting desirable effects in materials and it has been an area of enormous interest in the last few decades. Radiation processing of synthetic and natural polymers for improving their characteristics is largely used in laboratory and industrial scale. Radiation sterilization is a well developed and established technology for many products. It is especially useful for the treatment of pharmaceuticals due to flexibility of radiation processing to be carried out at any desired temperature, sterilizability of mixed products in kits, offering simultaneous sterilization and modification of polymer based formulations. The success of radiation technology for processing of synthetic and natural polymers and treatment of pharmaceuticals has been based, to a large extent, on empirical knowledge. But now, the applications of natural polymers are being sought in knowledge-demanding areas such as pharmacy and biotechnology. Reliable analytical methods are being developed for controlling of degradation effects of radiation on polymers. Procedures and chemical formulations are being investigated enhancing or preventing degradation effects depending on the desired application of the process. The Coordinated Research Project (CRP) on the use of radiation processing for sterilization or decontamination of pharmaceuticals and pharmaceutical raw materials has been completed in 2002. The overall objective of the CRP was to coordinate the research and development programmes carried out in different countries in use of radiation processing for sterilization or decontamination of pharmaceuticals and pharmaceutic raw materials. It has been concluded that in addition to well known advantages of radiation sterilization being a well developed and established technology requiring the control of only one parameter, dose, to achieve sterilization; it is especially useful for the treatment of pharmaceuticals due to flexibility of radiation

Sterilization of DACUS CUCUMIS FRENCH (DIPTERA:TEPHRITIDAE) by gamma radiation

International Nuclear Information System (INIS)

Hooper, G.H.S.

1975-01-01

The effect of gamma radiation administered to newly emerged adults of Dacus cucumis French on sterility and competitiveness was evaluated. A dose of 11 krad caused almost complete sterility in males while females given 6 krad were totally sterile, through infecundity. Sterilized males showed reduced competitiveness. In competitive mating tests a dose of 7 krad gave the lowest egg hatch and this hatch was significantly lower than that given by 9 and 11 krad. In a paired comparison mating test, 7 and 9 krad treated males mated significantly less frequently than untreated males, but the ability of 6 krad treated males was unimpared. (author)

Better health care: Ghana uses radiation technology to sterilize medical items

International Nuclear Information System (INIS)

Dixit, Aabha

2015-01-01

Infections acquired from improperly sterilized equipment are recognized as a major impediment to safe health care delivery, with consequences that are often deadly for patients. Radiation technology plays a major role in many countries in making medical equipment safer. “The use of nuclear applications, such as exposing medical items to gamma radiation, helps Ghana protect its people from avoidable sicknesses that can occur if items like syringes are not properly sterilized,” said Abraham Adu-Gyamfi, Manager of the Radiation Technology Centre of the Ghana Atomic Energy Commission’s Biotechnology and Nuclear Agriculture Research Institute in Accra.

Radiation induced sterility in a diploid and a tetraploid species of Physalis

International Nuclear Information System (INIS)

Gupta, S.K.; Roy, S.K.

1986-01-01

Biological damage sensu cytogenetical alterations was systematically scored in a diploid (P. ixocarpa), and a tetraploid (P. peruviana) species of Physalis after different doses of gamma-irradiation and evaluated on the parameters of pollen and plant sterility. There was a gradual reduction in the survival of seedlings which was realized more in P. ixocarpa than in P. peruviana. The meiotic abnormalities affected normal pollen formation, thereby contributing to pollen sterility and concomitantly to plant sterility. The sterility of pollen and plant were interconnected and related with the employed radiation doses in M 1 and M 2 generation. But their frequencies were fewer in M 2 than M 1 . The overall response of the two species to any particular dose of radiation was different, but the interesting point that emerged is that the meiotic abnormalities and pollen sterility were greater in tetraploid species, whereas plant sterility was more in the diploid. Significance of these observations have been discussed. An overall assessment was that the diploid species is more radiosensitive than the tetraploid one. (author)

Radiation sterilization of enzyme hybrids with biodegradable polymers

International Nuclear Information System (INIS)

Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

2002-01-01

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 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

The Use of Tygon Tubing Sterilized by Gamma Radiation in Heart-Lung By-Pass Machines

Energy Technology Data Exchange (ETDEWEB)

Alladine, M. F.; Gibbons, J. R. P. [London Chest Hospital, London (United Kingdom)

1967-09-15

Tygon tubing is a co-polymer polyvinyl chloride. This tubing is used throughout the circuit of our heart-lung by-pass machines and had been sterilized by autoclaving or exposure to ethylene oxide gas. Tubing sterilized by autoclaving was noted to have a decrease in tensile strength and the transparency of the tubing was affected. Sterilization by ethylene oxide had the disadvantage that gas was often present in the lumen of the tube when connected to the machine. Lengths of Tygon tubing were sterilized by gamma radiation at varying radiation levels and temperatures. Bacteriological studies were done on the tubing and estimation of tensile strength carried out. We have found that a level of radiation of 2. 5 to 3. 0 Mrad at 20°C produces little or no change in tensile strength and the tubing remains bacteriologically sterile. Tygon tubing sterilized in this way has now been used in over sixty heart-lung by-pass machine operations. (author)

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 ...

Inherited sterility in Eldana saccharina Walker (Lepidoptera: Pyralidae): effect of sub-sterilizing doses of gamma radiation on mating, fecundity and fertility

International Nuclear Information System (INIS)

Annoh, C.E.; Adabie-Gomez, D.A. Biotechnology and Nuclear Agriculture Research Institute; Botchey, M.A.; Mensah, B.A.

2003-01-01

Mature pupae (6-8 days old) of Eldana saccharina were exposed to increasing sub-sterilizing doses of ionizing gamma radiation in the range of 80-180 Gy. In the parental (P) generation, emerged male and female moths were out-crossed with untreated moths of the opposite sex. Reciprocal crosses between progeny of treated and untreated moths were also made in the F1 generation. In both generations, radiation doses used did not have any significant effect on mating behaviour of adults E. saccharina. There was also no significant difference in the mean number of spermatophores (approximately 1.0 per female) transferred by males to females during copulation among treated and control crosses. Fecundity in the parental generation was reduced by 40-44% in crosses between treated males and untreated females without any clear dose dependence. In the reciprocal crosses, however, fecundity considerably decreased with the increasing dose of radiation. The dose-dependent decreased of fecundity, similar in both reciprocal crosses, was also observed in F1 generation. Increasing doses of radiation generally resulted in decreasing fertility of treated moths in both the P and F1 generations. There was, however, a remarkable difference between reciprocal crosses. While radiation induced only partial sterility of treated P males even at the highest dose (180 Gy), treated P females exhibited a high sterility at 100 Gy. In both F1 crosses, fertility was lower than in treated P males, and F1 males exhibited a higher level of inherited sterility than F1 females. The results demonstrate a potential of using inherited sterility in integrated pest management programme to suppress the pest population of E. saccharina and other related stemborer species (author)

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)

Gamma radiation sterilized amnion: use in ophthalmology

International Nuclear Information System (INIS)

Martinez P, M. E.; Leon T, Y.; Vazquez M, L.

2010-10-01

Amnion processed at the Radio sterilized Tissue Bank at the National Institute of Nuclear Research, sterilized with 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)

Validation for radiation sterilization of surgical latex glove

International Nuclear Information System (INIS)

Liu Degui

2002-01-01

Objective: To determine the optimal radiation mode for sterilization of surgical latex gloves. Methods: The dose distribution in the product loads inside radiation container was measured in different radiation mode. Results: Data of dose distribution in the product load in different radiation mode were obtained. Conclusion: At pre-set height of source working position and within pre-determined dwelling time of each irradiation container staying at the irradiation position, the delivered dose can meet the customers requirement by the radiation mode that, in the half cycle of radiation process, turns the horizontal middle layers of the product to the upper or lower layers, and the upper and lower layers to the middle layers

Sterilization plants equipped with the isotopic gamma radiation sources

International Nuclear Information System (INIS)

Mehta, K.; Chmielewski, A.G.

2007-01-01

Presentation describes different isotopic gamma radiation sources applicable for sterilization of food and medical materials. Certain gamma pallet irradiators, mini gamma irradiators and different scale gamma tote irradiators are presented. It is concluded, that about two hundreds plants with gamma radiation sources operates in different countries. However, industrially developed countries must construct much more plants than operates now

Sterilization of sera and vaccines by cobalt gamma radiation

International Nuclear Information System (INIS)

Guidolin, R.; Morais, J.F.; Higashi, H.G.; Correa, A.; Cicarelli, R.M.B.; Previde, E.

1988-01-01

Diphtheria, tetanus, anti-snake venom sera and Diphtheria-Pertussis-Tetanus vaccine were submitted 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 heterogeneous hyper immune 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. (author)

Utilization of ionizing radiation for the sterilization of membraneous connective tissue allografts. Part of a coordinated programme on radiation sterilization of medical products and biological tissues

International Nuclear Information System (INIS)

Triantafyllou, N.

1978-05-01

The work carried out, covered several aspects of radiation sterilization of membraneous allografts. In general the findings show that the sterilization of biological membranes with gamma irradiation using doses of up to 3 Mrads is a very satisfactory method for the sterilization of the material, since it does not seriously alter the biological properties of allografts. As for the changes of the mechanical properties, this is not considered to be a serious draw back, because the membraneous allografts cover surgical needs where the mechanical strength is not of paramount importance

Studies on F1 radiation sterilization of diamondback moth and mulberry wild silkworm

International Nuclear Information System (INIS)

Yang Rongxing; Xia Darong; Cu Weiping; Chu Jiming; Zhang Yanjun

1993-01-01

The study began in 1988 under the aegis of the FAO/IAEA co-ordinated research programme on Radiation Induced F 1 Sterility in Lepidoptera for Area-Wide Control. During the following four years the control of the mulberry wild silkworm (Bombyx mandarina Moore) and the diamondback moth (Plutella xylostella L.) by means of radiation induced sterility was studied. (author). 4 refs, 9 figs, 6 tabs

Development of the microbiological control aspects of radiation sterilization of medical supplies. Part of a coordinated programme on radiation sterilization of medical and biological products

International Nuclear Information System (INIS)

Horakova, V.

1978-06-01

The variability and extent of microbial contamination of such medical supplies as hydrophilic gauze swabs and dermo-epidermal grafts were investigated. Gross bacterial contamination was observed in the swabs, with a relative absence of water. It was concluded that medical disposable products under dried aerobic conditions can be sterilized by a minimum dose of 25 kJ/kg/2.5 Mrad if the mean value of pre-sterilization bacterial counts does not exceed 100. Products contaminated by 10,000 or more bacteria prior to sterilization must be considered ''decontaminated'' after irradiation but as rather than ''sterile'', as accepted pharmaceutically. The author recommends that the efficacy of the sterilization dose used be evaluated, assuming the decrease in contaminated items to follow the exponential law, with constants estimated as n=1.98 and k=0.44, and that the sterilization process to be controlled dosimetrically. In general, sub-process doses should be used before actual sterilization by ionizing radiation, in order to estimate the constants characterizing the decrease in contamination under given conditions. In skin grafts a dose of 25 kJ/kg was found to give a high guarantee of sterility. A minimum sterilizing dose of 20 kJ/kg was recommended, provided the mean value of microorganisms on 1 cm 2 of the disinfected and freeze-dried skin grafts from human cadavres was 100, without exceeding an upper limit of 130

Practical problems in radiation sterilization of medical devices made from plasticized PVC

International Nuclear Information System (INIS)

Beenen, J.H.

1990-01-01

The following three methods for sterilizing medical devices made from plasticised PVC are used in the Netherlands. 1. sterilization by steam, steam-air or superheated water. 2. sterilization by electron beam or gamma irradiation. 3. ethylene oxide sterilization. IV-bags, blood bags and other bag types for similar applications made from plasticized PVC are mostly sterilized by steam-air or super heated water, especially when filled or partly filled containers are considered. More complicated products or products with components that cannot resist steam sterilization of 121 0 C are sterilized by ethylene oxide or irradiation. These last two methods also are favoured for sterilizing empty bags where sticking of the surfaces at the sterilization temperature creates a serious handicap. Moreover, steam sterilization may cause a permanent opacity of some plastics. However, we have to add that due to developments in formulations steam sterilization of empty bags is going to be of an increasing importance. proven carcinogenity of the gas ethylene oxide, difficult deaeration and retention of the gas in plasticized PVC has increased the demand for better radiation resistant plastics as an alternative for steam sterilization. (author)

Inherited sterility in insects

International Nuclear Information System (INIS)

Carpenter, J.E.; Marec, F.; Bloem, S.

2005-01-01

The unique genetic phenomena responsible for inherited sterility (IS) in Lepidoptera and some other arthropods, as compared with full sterility, provide advantages for pest control. Lepidopteran females are usually more sensitive to radiation than males of the same species. This allows the radiation dose to be adjusted to suit programme requirements. When partially sterile males mate with wild females, the radiation-induced deleterious effects are inherited by the F 1 generation. As a result, egg hatch is reduced and the resulting offspring are both highly sterile and predominately male. Compared with the high radiation required to achieve full sterility in Lepidoptera, the lower dose of radiation used to induce F 1 sterility increases the quality and competitiveness of the released insects as measured by improved dispersal after release, increased mating ability, and superior sperm competition. F 1 sterile progeny produced in the field enhance the efficacy of released partially sterile males, and improve compatibility with other pest control strategies. In addition, F 1 sterile progeny can be used to increase the production of natural enemies, and to study the potential host and geographical ranges of exotic lepidopteran pests. (author)

Discussion on the compilation of document of iso quality management system for radiation sterilization enterprises

International Nuclear Information System (INIS)

Li Chunhong; Ha Yiming; Zhou Hongjie; Feng Zhiguo; Wang Feng

2006-01-01

According to the character of cooperation of radiation sterilization, and association with request of ISO9001, ISO13485 and ISO11137, compilation of document in quality manual, procedure document and technological document during certification of ISO quality management system of cooperation of radiation sterilization was discussed. (authors)

Dose setting for radiation sterilization of dialyzers, (2)

International Nuclear Information System (INIS)

Kigawa, Akiko; Tateishi, Tsuneo; Iso, Katsuaki; Kimura, Toshio; Mamuro, Tetsuo; Misawa, Sho.

1986-01-01

It was found in the preceding study that the strain that showed the highest radiation resistance among the strains washed out of dializers not yet sterilzed was Bacillus megaterium and the D-value of its spore was about 40 percent higher than that of B. pumilus ATCC 27142 spore. In the present study, bundles of hollow fibers were inoculated with spores of both the B. megaterium and the B. pumilus and D-values of the spores were measured to be 0.24 7 and 0.16 9 Mrad, respectively. The dializer is consisted of several materials. Sterilization effect of gamma-ray irradiation is the least for hollow fibers, because they contain glycerin. It is concluded that 10 6 sterility assurance is achieved by setting the sterilization dose at 2.0 Mrad, about eight times of the D-value for the B. megaterium under the condition that the number of contaminants per product is less than 100. (author)

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)

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

International Nuclear Information System (INIS)

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

2017-01-01

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 "6"0Co source in human tendons pre-processed (A-alcohol + antibiotic; B- H_2O_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)

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.

Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

Energy Technology Data Exchange (ETDEWEB)

Martinez-Pardo, M.E. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico)], E-mail: memp@nuclear.inin.mx; Ley-Chavez, E. [ISSEMYM Toluca, Mexico DF (Mexico); Reyes-Frias, M.L. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico); Rodriguez-Ferreyra, P. [Hospital ' Dr. Nicolas San Juan' , Toluca, Mexico DF (Mexico); Vazquez-Maya, L.; Salazar, M.A. [Hospital General de Mexico, Mexico DF (Mexico)

2007-11-15

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.

Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

International Nuclear Information System (INIS)

Martinez-Pardo, M.E.; Ley-Chavez, E.; Reyes-Frias, M.L.; Rodriguez-Ferreyra, P.; Vazquez-Maya, L.; Salazar, M.A.

2007-01-01

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

Adjustment of gamma radiation doses for sterilization of Egyptian surgical sutures

International Nuclear Information System (INIS)

Tawfik, Z.S.; Helmy, M.M.; Roushdy, H.M.

1984-01-01

The adjustment of gamma radiation doses for sterilization of catguts under local manufacturing conditions has been performed. Average total initial counts for aerobic and anaerobic bacteria per item were relatively low, in the range of 1000 counts for aerobic and 10 counts for anaerobic bacteria. The microfiora (aerobic bacteria) of the studied sutures were isolated and identified to be: Bacillus sp.; Micrococcus varians, Micrococcus roseus, and Staphylococcus. Each purified and identified isolate was exposed to gamma radiation both in liquid media (broth) and in the preservative in which the sutures were supplied by the company. The LD values of the most resistant microorganisms in both case of liquid media and preservative, were obtained to be around 5 KGy. Deliberately contaminated sterile sutures with each isolate and with mixture of isolates were studied. The sterilizing dose was obtained to be 20KGy for most heavily contaminated items (10 10 counts) irradiated both in saline and in preservative. This sterilizing dose was found to be dependent of the initial viable counts. This value was considered to be a safe value for radiosterilization of the studied sutures preserved in isopropyl alcohol, glycerin, and water (90:3.5:16)

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 (p<0.001) increase in the absorption capacity. Moisture vapour transmission rate of the membranes was 4285.77±455.61 g/m2/24 h at 24 h. Gamma irradiation at 25 kGy was found suitable for sterilization 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.

Sterilization of MacConkey agar and CLED medium by gamma-radiation

Energy Technology Data Exchange (ETDEWEB)

Bogokowsky, B; Eisenberg, E; Altmann, G

1983-10-01

MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by gamma-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4 degrees C and compared well with freshly autoclaved media.

Research on dose setting for radiation sterilization of medical device

International Nuclear Information System (INIS)

Zhang Tongcheng; Liu Qingfang; Zhong Hongliang; Mi Zhisu; Wang Chunlei; Jiang Jianping

2002-01-01

Objective: To establish the radiation sterilization dose for medical devices using data of bioburden on the medical device. Methods: Firstly determination of recovery ratio and correction coefficient of the microbiological test method was used according to ISO11737 standard, then determination of bioburden on the products, finally the dose setting was completed based on the Method 1 in ISO11137 standard. Results: Fifteen kinds of medical devices were tested. Bioburden range was from 8.6-97271.2 CFU/device, recovery ration range 54.6%-100%, correction co-efficiency range 1.00-1.83, D 10 distribution from 1.40 to 2.82 kGy, verification dose (dose at SAL = 10 -2 ) range 5.1-17.6 kGy and sterilization dose (dose at SAL 10 -6 ) range 17.5-32.5 kGy. Conclusion: One hundred samples of each kind of product were exposed to the pre-determined verification dose and then the sterility test was performed. Each sterility test showed positive number was not greater than two. This indicated that the sterilization dose established for each kind of product was statistically acceptable

Radiation sterilization of tissue allografts: Requirements for validation and routine control. A code of practice

International Nuclear Information System (INIS)

2007-12-01

These recommendations for the radiation sterilization of tissue allografts adopt the principles that the International Organization for Standardization (ISO) applies to the radiation sterilization of health care products. The approach has been adapted to take into account the special features associated with human tissues and the features that distinguish them from industrially produced sterile health care products. The approach as described here is not applicable if viral contamination is identified. Thus it is emphasized that the human donors of the tissues must be medically and serologically screened. To further support this screening it is recommended that autopsy reports be reviewed if available. This adaptation of established ISO methods can thus only be applied to sterilization of tissue allografts if the radiation sterilization described here is the terminal stage of a careful, detailed, documented sequence of procedures involving: donor selection; tissue retrieval; tissue banking general procedures; specific processing procedures; labelling; and distribution. The methods proposed here for the establishment of a sterilization dose are based on statistical approaches used for the sterilization of health care products and modified appropriately for the low numbers of tissue allograft samples typically available. This code of practice will be useful to tissue banking staff, surgeons using tissues for transplantation, regulators who oversee the safety of transplantation and radiation sterilization procedures, members of tissue banking associations, health service personnel in hospitals in which tissue transplantations are performed and inter-governmental organizations involved in transplantation issues, for example the World Health Organization. This publication was discussed extensively at an international meeting in Wrexham in the United Kingdom and was approved by the Technical Advisory Committee of the relevant IAEA project, which included the Chairpersons

Possibilities of radiation sterilization for re-usage of medical devices in the medical management

International Nuclear Information System (INIS)

Tabei, Masae; Kudo, Hisaaki; Katsumura, Yosuke

2004-01-01

The rule for re-usage of medical single-use devices was established in US in 2000 based on the concept of Managed Care (total management of medicare on cost, quality and patients' satisfaction) and 20-30% of those devices are re-used at present. The re-usage is conducted in not only US but also Canada, Denmark, UK, India, China etc. Standing on the viewpoint, this paper described and discussed the possibility of re-usage of the single-use devices now prohibited in Japan, possible re-sterilization, possible re-usage of hollow fiber-type hemodialyzer following γ-ray sterilization with consideration for D-values against bacteria and viruses, cost estimation of electron beam sterilization for re-usage, and radiation sterilization of waste water and plastic materials. Radiation sterilization for re-usage of medical devices was concluded possible if their materials and records for their usage processes are proper, and should be conducted in a large scale after sufficient examinations by industries/government/academia. (N.I.)

9. School of radiation sterilization and hygienization - Lectures; 9 Szkola sterylizacji i higienizacji radiacyjnej - Wyklady

Energy Technology Data Exchange (ETDEWEB)

Zimek, Z; Kaluska, I; Gluszewski, W [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

2007-07-01

During the 9 School of radiation sterilization and hygienization 23 lectures were presented. They were devoted to all aspects of sterilization and hygienization of food, medicinal articles and cosmetics using the ionisation radiation. It was destined to physicians, manufacturers and vendees of spices, pharmaceuticals and cosmetics, personnel of the sanitary-epidemiological stations and even for the art conservators.

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...

Research on determination of bio-burden for radiation sterilization of health care products

International Nuclear Information System (INIS)

Liu Qinfang

2008-01-01

In order to provide data of bio-burden for dose setting in radiation sterilization, determination of bio-burden on 148 kinds of health care products from 52 manufacturers were carried out. The culture of microorganisms, different elution technology, and correction coefficient of the microbiological methods have been used for determination of bio-burden. Frequent distribution of bio-burden was established. 5 kinds of elution processes were checked. Actual data of bio-burden for dose setting in radiation sterilization was gotten. (authors)

Bacterial growth on Mueller Hinton medium sterilized by. gamma. -radiation

Energy Technology Data Exchange (ETDEWEB)

Eisenberg, E. (Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center); Bogokowsky, B.; Altmann, G. (Sheba Medical Center, Tel Hashomer (Israel); Tel Aviv Univ. (Israel). Medical School)

1981-12-01

The possibility of radiosterilization of culture media for the cultivation of bacteria was investigated. Mueller Hinton agar, a medium widely used for the propagation of some fastidious pathogenic bacteria, was sterilized with 1.0 and 1.5 Mrad doses of ..gamma..-radiation. Bacteria belonging to seven different species grew as well on the radiosterilized medium as on medium sterilized by heat in a conventional way. Reduction in colony size was observed on the radiosterilized medium with Staphylococcus aureus and Shigella boydii. Neisseria meningitidis, the most fastidious bacterium tested, did not grow at all. The addition of small amounts of catalase corrected the deleterious radiation effect and all bacteria tested could be successfully grown on irradiated Mueller Hinton agar supplemented with up to 11 Keil units catalase per liter medium.

Bacterial growth on Mueller Hinton medium sterilized by γ-radiation

International Nuclear Information System (INIS)

Eisenberg, E.; Bogokowsky, B.; Altmann, G.; Tel Aviv Univ.

1981-01-01

The possibility of radiosterilization of culture media for the cultivation of bacteria was investigated. Mueller Hinton agar, a medium widely used for the propagation of some fastidious pathogenic bacteria, was sterilized with 1.0 and 1.5 Mrad doses of γ-radiation. Bacteria belonging to seven different species grew as well on the radiosterilized medium as on medium sterilized by heat in a conventional way. Reduction in colony size was observed on the radiosterilized medium with Staphylococcus aureus and Shigella boydii. Neisseria meningitidis, the most fastidious bacterium tested, did not grow at all. The addition of small amounts of catalase corrected the deleterious radiation effect and all bacteria tested could be successfully grown on irradiated Mueller Hinton agar supplemented with up to 11 Keil units catalase per liter medium. (author)

Sterilization of MacConkey agar and CLED medium by. gamma. -radiation

Energy Technology Data Exchange (ETDEWEB)

Bogokowsky, B; Altmann, G [Sheba Medical Center, Tel Hashomer (Israel); Tel Aviv Univ. (Israel). Medical School); Eisenberg, E [Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center

1983-10-01

MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by ..gamma..-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4/sup 0/C and compared well with freshly autoclaved media.

Genetic and Cytogenetic Basis of Radiation-Induced Sterility in the Adult Male Cabbage Looper Trichoplusia Ni

Energy Technology Data Exchange (ETDEWEB)

North, D. T.; Holt, G. G. [Metabolism and Radiation Research Laboratory, Entomology Research Division, ARS, United States Department of Agriculture, Fargo, ND (United States)

1968-06-15

The relationship of egg hatch as a function of radiation dose is of a two-hit nature when irradiated adult males are mated to non-irradiated virgin females. Sterility as a function of dose is usually linear in insects. However, other species of moths respond similarly to irradiation, so it is indicative that the mechanism involved in producing sterility in Lepidoptera is basically different from that in other insects. The significance of the two-hit kinetics is discussed in relation to the chromosome structure and possible mechanisms for the induction of sterility in Lepidoptera. Many workers using Lepidoptera have reported that females mated to irradiated males oviposit substantially fewer eggs than normally. This response has been correlated to a lack of sperm transfer by irradiated males, even though they pass a spermatophore. The phenomenon is dose-dependent. Although Lepidoptera are far more radioresistant than other insect species when measured by the induction of sterility in the male, there appears to be very little difference when longevity is used as the criterion. The radiation dose required to reduce the lifespan of a newly emerged cabbage looper male by 50% was found to be approximately the same as that for the house fly. High doses of radiation have no immediate effect on the mating behaviour of the irradiated male. With a recessive eye-colour mutant as a sperm marker, it was determined in tests utilizing double matings that the second mating is the effective mating. Sperm mixing is not prevalent; rather it appears to be a 'sperm flushing' phenomenon in that sperm from the first mating are displaced by sperm from the second mating. Radiation studies with the cabbage looper have demonstrated that the progeny of a cross where the male parent receives a sub-sterilizing dose of gamma radiation are often semi-sterile when mated to non-irradiated individuals. The amount of inherited sterility is directly dependent on the amount of radiation given the

Effect of Gamma Radiation sterilization versus Disinfection on Removable Partial Dentures (Microbiological study)

International Nuclear Information System (INIS)

Mohammed, M.A.

2011-01-01

The aim of the study was to compare between the effectiveness of disinfection, using commercially available Fittydent super cleansing tablets versus sterilization, using gamma radiation on candidal growth in maxillary removable partial dentures. Methods: Fourteen partially edentulous subjects were selected according to specific criteria and divided equally and randomly into two groups; Group I: disinfection group and Group II: sterilization group. Conventional maxillary removable partial dentures were constructed for all subjects. The swab technique was used to collect the samples one month after denture delivery, immediately after disinfection/sterilization, and then one week, two weeks, three weeks, four weeks, and five weeks after disinfection/sterilization respectively. Bacteriological candidal colony count was performed using a manual contact colony counter. Results: Both methods (disinfection and sterilization) led to a noticeable decrease in the candidal count. However this decrease was highly and markedly evident in Group II as compared to Group I. Infact, no candidal growth was recorded for group II immediately after strerilization and was maintained for two more weeks. Statistical analysis revealed highly significant differences between the two groups. Conclusions: Both methods were effective in decreasing the number of Candida albicans adhering to the denture. However, sterilization using Gamma radiation had a more superior immediate, as well as, long term efficiency as compared to disinfection using Fittydent super cleansing tablets.

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...... mapping. The paper further gives recommendations for effective dose mapping including traceable dosimetry, documented procedures for placement of dosimeters, and evaluation of measurement uncertainties. (C) 1999 Elsevier Science Ltd. All rights reserved....

Radiosterilization and gas sterilization

International Nuclear Information System (INIS)

Schultz, H.A.; Gruenewald, T.

1987-01-01

The book presents a survey of the principles of cold sterilization by radiation or gas, and also of the problems involved. The reader who has to do with sterilization of some kind or other, as e.g. sterilization of medicaments, medical supplies, medical device, drugs, grafts, or food, will find comprehensive information on the various available methods and their effects, as well as on monitoring procedures and techniques, together with proposals for efficient documentation and validation of partial sterilization processes. The introduction summarizes the potentials of sterilization by radiation, and the subsequent by radiation, and the subsequent chapters explain the specific applicabilities of radiosterilization along with the most important criteria for evaluating the sterilizing efficiency. The information on the legal situation and requirements takes into account the second amendment of the Medical Preparations Act. With 38 figs., 14 tabs [de

Chemical and biological effects of radiation sterilization of medical products

International Nuclear Information System (INIS)

Gupta, B.L.

1975-01-01

Radiation is extensively used for the sterilization of plastic materials, pharmaceuticals and biological tissue grafts. The pharmaceuticals may be solid, liquid, or suspension in a liquid or a solution. Cobalt-60 gamma radiation, generally used for sterilization, primarily interacts with these materials through the Compton process. The resulting damage may be direct or indirect. In aqueous systems the primary species produced compete for interaction among themselves and the dissolved solutes. The nature, the G-values and the reactions of the primary species very much depend on the pH of the solution. The important chemical changes in plastic materials are gas liberation, change in concentration of double bonds, cross-linking, degradation and oxidation. These chemical changes lead to some physical changes like crystallinity, specific conductivity and permeability. The reactions in biological systems are very complex and are influenced by the presence or absence of water and oxygen. Water produces indirect damage and the radiation effect is generally more in the presence of oxygen. Most microorganisms are relatively radioresistant. Various tissues of an animal differ in their response to radiation. Catgut is not stable to irradiation. Lyophilized human serum is stable to irradiation whereas, when irradiated in aqueous solutions, several changes are observed. Generally, pharmaceuticals are considerably more stable in the dry solid state to ionizing radiations than in aqueous solutions or in any other form of molecular aggregation. (author)

Gamma-sterilization

International Nuclear Information System (INIS)

Lindgren, E.

1974-01-01

The author makes a survey of his experience in sterilization and sterility control of medical products. At present three different methods are used, steamsterilization, gassterilizing and gammasterilizing. The investments and costs for gamma radiation is presented and a comparison of the costs for gamma- and gassterilization including sterility control is made. (M.S.)

The impact of European standards concerning radiation sterilization on the quality assurance of medical products in Poland

International Nuclear Information System (INIS)

Kaluska, I.; Zimek, Z.

1999-01-01

The ISO 11137 and EN 552 standards were issued in the mid-90's. These documents have been devoted to the requirements regarding the sterile medical devices offered on the market. The implementation of those standards by Polish manufacturers of medical devices is discussed in this paper. The currently introduced national regulations effectively stimulated this process. The activities of the Institute of Nuclear Chemistry and Technology (INCT) in the field of radiation sterilization standardization and its radiation sterilization commercial service are described. (author)

Radiation treatment for sterilization of packaging materials

International Nuclear Information System (INIS)

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

2007-01-01

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

Feasibility studies of radiation sterilization of some pharmaceutical products

International Nuclear Information System (INIS)

Gopal, N.G.S.; Rajagopalan, S.; Sharma, G.

1975-01-01

The paper deals with some studies carried out to evaluate the feasibility of radiation sterilization or treatment of some medical products and pharmaceuticals of immediate importance to their respective industries. The products include penicillin G sodium, ampicillin sodium, tetracyclin hydrochloride ointment,hydrocortisone acetate and its ointment, aqueous sodium chloride solutions (0.9 and 20%), fluorescein sodium strips, urea, ethylmorphine hydrochloride, aqueous solution of chlorobutanol and one of its commercial preparations, phenylmercuric nitrate and its aqueous solutions, aqueous solutions of methyl and propyl paraben, lactose, gum karaya, absorbent cotton and poly-(vinyl chloride) based medical products. The irradiated products have been examined for pharmacopoeial specifications wherever available. In general the products have been examined for changes in colour, pH, ultra-violet and infra-red absorption spectra. Thin-layer chromatographic analyses have been carried out to establish the purity of some of the irradiated products. The feasibility or otherwise of radiation sterilization or treatment of the various products from the physicochemical and microbiological (pharmacological) clinical considerations is also described. (author)

An assay of the physicochemical characters of radiation sterilized plastic transfusion

International Nuclear Information System (INIS)

Liu Keliang

1988-01-01

In order to adapt radiation sterilization to the need of clinical use by means of 3 H-TdR incorporation, the physicochemical charaters were studied between irradiated and unirradiated plastic transfusion sets. The results showed that a large radiation dose of 2.5 to 10 x 10 4 Gy had no damage on the plastic transfusion sets, nor toxic to human

Radiating sterilization of the venom of snake

International Nuclear Information System (INIS)

Abiyev, H.A.; Topchiyeva, Sh.A.; Rustamov, V.R.

2006-01-01

Full text: Water solutions of venoms are unstable and they lose toxicity in some day. Snake venoms inactivate under action of some physical factors: the UV-irradiation, x-rays beams. The purpose of the present work was sterilization of venom Vipera lebetina obtusa under influence of small dozes γ-radiations. Object of research was integral venom of adult individuals. Transcaucasian viper, and also the water solutions of venom irradiated with small dozes scale of radiation. An irradiation of venom carried out to radioisotope installation 60NI. For experiment tests of dry venom, and also their water solutions have been taken. Water solutions of venom have been subjected -radiation up to dozes 1.35, 2.7, 4.05, 5.4 kGr simultaneously dry venom of vipers was exposed -radiation before absorption of a doze 5.4 kGr. In comparative aspect action scale of radiation on ultra-violet spectra of absorption of venom was studied. Ultra-violet spectra venom have been taken off on device Specord UV-VIS. In 12 months after an irradiation spectra of absorption of venom have been repeatedly taken off. In spectra irradiated dry and solutions of venom new maxima of absorption have been revealed in the field of 285 nm and 800 nm describing change of toxicity. It is shown, that the increase in absorption of a doze of radiation occurs decrease of intensity of strips of absorption reduction of intensity of absorption.It is revealed at 260 and 300 nm testifying to course of biochemical reactions of separate enzymes zootoxins. It is necessary to note, that at comparison of intensity of absorption of control samples of poison with irradiated up to dozes 1.35 kGr it has not been revealed essential changes. The subsequent increase in a doze scale of radiation up to 2.7, 4.05, 5.4 kGr promotes proportional reduction of intensity of the absorption, describing toxicity of snake venom. At repeated (later 12 months) measurement of the irradiated water solutions of venom are not revealed changes in

Radiation induced F1 sterility in the management of lepidopterous pests: concept, overview and prospects

International Nuclear Information System (INIS)

Harwalkar, M.R.

1994-01-01

The phenomenon of F1 or inherited sterility has been observed in a number of important pests which include Heliothis virescens, H. Zea, Trichoplusia ni etc.. Key findings that have advanced in the development of radiation sterilization technique are reviewed. 2 refs

Laboratory methods used for testing the effect of radiation sterilization and preservation procedures on bone allografts

International Nuclear Information System (INIS)

Dziedzic-Goclawska, A.

1999-01-01

Sterilization of tissue allografts with ionizing radiation introduced in the mid of 1950s is more and more frequently used in tissue banking practice. The dose of 25 kGy is currently recommended and commonly used by many tissue banks in the world with the exception of the Central Tissue Bank in Warsaw where the dose of 33 kGy + 10 % has been routinely used since 1963, and from 1997 the dose of 35 kGy + 10 % has been introduced. To study the effect of radiation-sterilization on bone allografts the interdisciplinary investigations have been undertaken and several techniques have been implemented in our tissue bank. The electron paramagnetic resonance (EPR) spectroscopy has been applied to investigate the amount, origin and stability of free radicals and other paramagnetic entities induced in radiation-sterilized bone allografts. This technique has been also utilized for quantitative evaluation of remodeling process of radiation-sterilized bone allografts and for estimation of the absorbed dose of ionizing radiation using bone tissue as a dosimeter. A model of heterotopically induced osteogenesis after transplantation of devitalized bone matrix into the muscle (described by Urist in 1965) is very useful in tissue banking practice. It allows one to determine the contribution the graft itself makes to osteogenesis. This model is routinely used in our tissue bank to evaluate the effect of various sterilization and preservation procedures on osteoinductive properties of bone allografts. The solubility in vitro of collagen - a carrier for bone morphogenetic proteins (BMPS) and a major constituent of bone and the other connective tissue grafts, has been studied by measuring the amount of extracted neutral, acid and total soluble collagen from bone grafts preserved by different methods at irradiated at vanous experimental conditions. A positive correlation between collagen solubility in vitro and the rate of graft resorption in vivo has been observed. The high doses of

Tissue banking and clinical research on radiation and ethylene oxide sterilization of tissue grafts

International Nuclear Information System (INIS)

Pe Khin

1987-06-01

The research works carried out in Rangoon, Burma under the Agency supported project RC4420/RB have dealt with an elucidation of the radiation interaction(s) with the species of biomolecules such as proteins, lipids, collagens, connective tissues present in the cleaned and freeze-dried non-viable tissue grafts. Radiation as a cool process furthermore effectively helps to destroy the microbial bioburden as the undesirable contaminants which may associate the tissue grafts. Radiation also concomitantly helps to suppress the tissue-specific immunogenicity. All these attributes of radiation induced effects have proved successful towards the development of a sterilization process. A series of non-viable tissue grafts, such as bone, nerve, fascia, dura, cartilage, chorion-amnion (as dressings in burn wounds) and tympanic membrane have been successfully attempted in Burma and many more possibilities seem to still remain unexplored. Radiation sterilization modality has proved as a blessing for the promotion of clinical surgical applications of tissue allografts in the corrective/reconstructive surgery on the disability cases due to diseases which accompany tissue losses. The investigator in Burma has reported on the case histories where freeze dried radiation sterilized tissue allografts have been successfully used in the osteogenic inductions (bone grafts); midear tympanoplasty; partial recovery of nerve sensation throught nerve allografts; rapid healing of high degree burn wounds through the use of amnion dressings. Besides, there have been a widespread surgical use of radiation sterilized dura and fascia as allografts. A national tissue banking facility has been established in Burma surrounding the processing and clinical utilization of tissue allografts which has involved over ten hospital centres throughout the country. Radiation induced effects on the biomolecules of clinical significance in the tissue grafts have been researched to help gain insight into a better

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.

Validation of radiation sterilization process

International Nuclear Information System (INIS)

Kaluska, I.

2007-01-01

The standards for quality management systems recognize that, for certain processes used in manufacturing, the effectiveness of the process cannot be fully verified by subsequent inspection and testing of the product. Sterilization is an example of such a process. For this reason, sterilization processes are validated for use, the performance of sterilization process is monitored routinely and the equipment is maintained according to ISO 13 485. Different aspects of this norm are presented

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.

Release of bound residues of atrazine from soils through autoclaving and gamma radiation sterilization

International Nuclear Information System (INIS)

Nakagawa, L.E.; Andréa, M.M.

1997-01-01

The sterilization methods are particularly important to study the influence of microorganisms on the pesticide dissipation in soils. This study, conducted in the laboratories of the Instituto Biológico of São Paulo in august 1996, tested the influence of two methods of soil sterilization - moist heat (autoclaving) and γ radiation - on the release of nonextractable or bound residues. It was studied, as example, bound residues of the herbicide atrazine in two types of soil (gley humic and dark red latosol). In the soil samples submitted to the moist heat sterilization, the recovery of the previously bound residues as reextractable residues was 5.6 and 5.9 times higher than in the control soils, not submitted to any sterilization process. Therefore, the method itself released the residues, indicating that the autoclaving is not the most appropriate method for studies on the influence of microorganisms on the release of bound residues. Otherwise, the γ radiation did not modify the residues recovery when compared to the controls. (author) [pt

Radiation sterilization of medical products in the Philippines

International Nuclear Information System (INIS)

Singson, C.; Carmona, C.; Guzman, Z. de; Barrun, W.; Lanuza, L.

1983-01-01

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. (author)

Radiation sterilization of medical products in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Singson, C; Carmona, C; Guzman, Z de; Barrun, W; Lanuza, L [Philippine Atomic Energy Commission, Diliman, Quezon City

1983-01-01

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D/sub 10/ values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged.

Genetic basis of the sterile insect technique

International Nuclear Information System (INIS)

Robinson, A.S.

2014-01-01

The use of the sterile insect technique for insect control relies on the introduction of sterility in the females of the wild population. This sterility is produced following the mating of these females with released males carrying, in their sperm, dominant lethal mutations that have been induced by ionizing radiation. As well as radiation-induced sterility, natural mechanisms can be recruited, especially the use of hybrid sterility. Radiation is usually one of the last procedures that insects undergo before leaving mass-rearing facilities for release in the field. It is essential that the dosimetry of the radiation source be checked to ensure that all the insects receive the required minimum dose. A dose should be chosen that maximizes the level of introduced sterility in the wild females in the field. Irradiation in nitrogen can provide protection against the detrimental somatic effects of radiation. Currently, the development of molecular methods to sterilize pest insects in the field, by the release of fertile insects carrying trans genes, is very much in vogue. It is concluded that using a physical process, such as radiation, will always have significant advantages over genetic and other methods of sterilization for the large-scale application of the sterile insect technique. (author)

Radiating sterilization of fruits of the barberry ordinary berberis vulgaris L

International Nuclear Information System (INIS)

Abilova, I.E.

2006-01-01

Full text: The riches of flora of Azerbaijan with its specific saturation represent a huge raw-material base for a farmaceutical industry. In territory of republic 3 kinds of a barberry wildly grow, a perspective kind is the barberry ordinary Berberis vulgaris L.In the medical purposes leaves, a root, stalks and fruits of a barberry are applied. Berries as water tincture are applied at rheumatism, a malaria, a diabetes [I.A.Damirov and etn-tilde 1988; Hofbauer F., Askeril M, 2002, etc.], at diseases of a gastroenteric path, easy, at diseases of a mouth [Ikram M, 1975]. Biochemical processes in the collected raw material during first time proceed, as in an alive plant, that is synthesis of biologi-cally active substances prevails. On a measure natural losing water in connection with the termination of receipt of a moisture and nutrients, processes of an exchange are shifted aside disintegration that results in decrease of biologically active substances in vegetative raw material. However in some cases the processes proceeding in drying raw material result on the contrary, in increase in the maintenance of working substances. Therefore improvement of ways of drying and processing of medicinal raw material by influence of small dozes ? - radiations c the purpose of reception of the high-quality raw material, connected with growing need of a global farmaceutical industry for herbs and phitopreparats is an actual problem. As a result of experimental researches conditions of radiating sterilization of fruits of a barberry ?-radiation are picked up at small dozes and at different values ionizating radiations. Fruits of a barberry were irradiated with ?-radiation on radioisotope installation 60n-tildei-circumflex at values of a doze of an irradiation in limits from 1.0 up to 1.5eGr at duration of an irradiation till 30 minutes. The qualitative control were carried out chromatografic (thin layer chromatography) and spectral (UV-VIS and IR) methods later 6, 12 and 24 months

Interaction of gamma radiation and temperature on the determination of the sterilizing dose of some stored products pests

International Nuclear Information System (INIS)

Barbosa, A.P.

1976-08-01

The influence of temperature on sterilizing dosages of gamma radiation was studied for Sitophilus zeamais Mots. in corn, Sitophilus oryzae (L.) in rice, Araecerus fasciculatus (DeGeer) in coffee, and Zabrotes subfasciatus (Boh.) in beans. It was found that temperature has a significant influence on the amount of radiation required to sterilize these species. The highest radiation dosages were required at those temperature most nearly optimum for insect development. The minimum radiation doses required for complete sterility of each species at the indicated temperatures were as follows: Sitophilus zeamais Mots. in corn, 8 krad at 24 0 C; Sitophilus oryzae (L.) in rice, 9 krad at 24 0 C; Araecerus fasciculatus (DeGeer) in coffee, 6 krad at 30 0 C; Zabrotes subfasciatus (Boh.) in beans, 9 krad at 24 - 27 0 C. At either higher or lower temperature smaller radiation dosages were required. (author) [pt

Combined effects of a chemical mutagen and radiation sterilized diet in mutagenicity and reproduction studies in the same mouse

International Nuclear Information System (INIS)

Renner, H.W.

1975-01-01

The possible intensification of the mutagenic effect of cyclophosphamide (Endoxan) by the feeding of a radiation-sterilized diet (dose, 4.5 Mrad) was studied in 2000 NMRI/Han mice. In a dominant lethal test, males were pretreated with 100 mg Endoxan/kg body weight. The greatest sensitivity towards Endoxan was observed during the late-spermatid stage. No significant differences were detected between the control group (Endoxan plus non-irradiated diet) and the experimental group (Endoxan plus radiation-sterilized diet). In this test, radiation-sterilized feed showed no co-mutagenic effect when combined with Endoxan treatment. In a reproduction study of 7 months duration (continuous mating without lactation periods), the females were treated every 2 wk with 20 mg Endoxan/kg body weight. The decline in litter size with increasing number of litters (i.e. with advancing age of the females) was more pronounced after treatment with the chemical mutagen than in the untreated group. Increases in the frequency of abortions and in premature sterility resulted from Endoxan treatment. During the entire observation period, no effects from the intake of radiation-sterilized food were detected. (author)

Modernization of safety system for the radiation facility for industrial sterilization

International Nuclear Information System (INIS)

Drndarevic, V.; Djuric, D.; Koturovic, A.; Arandjelovic, M.; Mikic, R.

1995-01-01

Modernization of the existing safety system of the radiation facility for industrial sterilization at the Vinca Institute of nuclear science is done. In order to improve radiation safety of the facility, the latest recommendations and requirements of IAEA have been implemented. Concept and design of the modernized system are presented. The new elements of the safety system are described and the improvements achieved by means of this modernization are pointed out. (author)

The effect of radiation-sterilization conditions and preservation procedures on physico-chemical and biological properties of bone allografts

International Nuclear Information System (INIS)

Goclawska, A.D.; Kaminski, A.; Wasilewska, M.

1999-01-01

Radiation-sterilization of connective tissue allografts (bone including) with a dose of 35 kGy is routinely used in the Central Tissue Bank in Warsaw since 1963. This method of sterilization offers many advantages: good penetration ability, relatively low temperature rise, and possibility of sterilization of grafts in closed beforehand vials, which protects against secondary contamination. It should be kept in mind, however that high doses of ionizing radiation (in the range of 20-35 kGy) used for sterilization evoke many chemical and physical changes which may influence biological properties of grafts. These changes have been studied using various methodological approaches. Using electron paramagnetic resonance (EPR) spectrometry it has been found that in radiation-sterilized bone two types of paramagnetic entities are generated: i/ coliagen radicals which are unstable and disappear completely in the presence of air oxygen, ii/ very stable at room temperature paramagnetic defects (centers) localized in the crystalline lattice of bone mineral. These stable paramagnetic defects have been treated as a new kind of markers and used for: a/ quantitative evaluation of remodeling process of radiation-sterilized bone allografts preserved by lyophilization or deep freezing; b/ estimation of the dose of ionizing radiation absorbed by living organism in the case of accidental exposure (skeleton serving as a dosimeter) and for control of radiation-sterilization process. The effect of radiation-sterilization and preservation procedures on bone allografts was studied using a model of heterotopically induced osteogenesis and measuring the solubility of bone collagen in vitro. It has been observed that lyophilized bone allografts irradiated at room temp. with doses of 35 and 50 kGy, respectively, were very quickly resorbed in vivo and did not induce osteogenesis, while lyophilized as well as deep-frozen matrices irradiated at -7OoC were slowly resorbed and induced de novo bone fon

Sterilization of health care products - Radiation. Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices

International Nuclear Information System (INIS)

2006-01-01

A sterile medical device is one that is free of viable microorganisms. International Standards, which specify requirements for validation and routine control of sterilization processes, require, when it is necessary to supply a sterile medical device, that adventitious microbiological contamination of a medical device prior to sterilization be minimized. Even so, medical devices produced under standard manufacturing conditions in accordance with the requirements for quality management systems (see, for example, ISO 13485) may, prior to sterilization, have microorganisms on them, albeit in low numbers. Such medical devices are non-sterile. The purpose of sterilization is to inactivate the microbiological contaminants and thereby transform the nonsterile medical devices into sterile ones. The kinetics of inactivation of a pure culture of microorganisms by physical and/or chemical agents used to sterilize medical devices can generally best be described by an exponential relationship between the numbers of microorganisms surviving and the extent of treatment with the sterilizing agent; inevitably this means that there is always a finite probability that a microorganism may survive regardless of the extent of treatment applied. For a given treatment, the probability of survival is determined by the number and resistance of microorganisms and by the environment in which the organisms exist during treatment. It follows that the sterility of any one medical device in a population subjected to sterilization processing cannot be guaranteed and the sterility of a processed population is defined in terms of the probability of there being a viable microorganism present on a medical device. This part of ISO 11137 describes requirements that, if met, will provide a radiation sterilization process intended to sterilize medical devices, that has appropriate microbicidal activity. Furthermore, compliance with the requirements ensures that this activity is both reliable and

Radiation dose setting for sterilization of health care items in relation to product microbiological quality

International Nuclear Information System (INIS)

Norimah Yusof; Nagi Marsit; Asnah Hassan

1997-01-01

Radiation dose of 25 k gray is no longer a generally accepted dose for sterilization. ISO document no. 11137 stated that a manufacturer can decide the dose to sterilize his product depending on the product's microbiological quality (number and type of the contaminants) and the sterility assurance level (SAL) should attain in relation to its usage. Five health care products were selected for the microbiological studies including bio burden counts, identification of most commonly found microorganisms and the radioresistance (D sub 10 value) of the selected isolates. Radiation dose was then determined by two methods, namely Method for Dose Validation of ISO 11137, and calculation based on log survival or population cycle reduction. At a given SAL of 10 sup -6 the radiation sterilization dose obtained by both methods was influenced by microbiological quality of the product. Sterilization dose set by the ISO Method I (Cotton Ball 19.4 kGy, Syringe 20.4 kGy, Suture 15. 0 kGy, Surgical Glove 24.9 kGy and Amnion 17.8 kGy) was higher than the dose calculated according to the log cycle reduction concept in all the products (Cotton Ball 14. 0 kGy, Syringe 15.5 kGy, Suture 11. 6 kGy, Surgical Glove 18. 0 kGy and Amnion 12.6 kGy). The ISO method has limitation on bio products such as amnion and other high valued products which are produced in small number with low bio burden and microorganism spectrum different from those commonly found on medical items

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

International Nuclear Information System (INIS)

Li Fengmei; Wang Ying; Liu Xiaoguang; Yang Baoyu

2000-01-01

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. (author)

Studies On Sterilization Process For Some Traditional Products Of Herbal Medicine By Gamma Radiation

International Nuclear Information System (INIS)

Hoang Phuong Thao; Nguyen Van Binh; Tran Bang Diep; Hoang Dang Sang; Nguyen Thuy Huong Trang; Pham Duy Duong; Tran Minh Quynh

2014-01-01

Herbal eyebright products and their raw materials have been irradiated with 1, 2, 3 and 5 kGy by Co-60 gamma radiation source at Hanoi Irradiation Center (VINATOM) for sterilization. Initial bioburdens were under the limitation levels established for the traditional medicines according to the decree of 16/2011/TT-BYT issued by Vietnam Health Ministry. These values for both bacteria and fungus slightly increased during storage to three months, reach to about 10 3 and 10 2 CFU/g for bacteria and mold, respectively. However, there are no microbial colony could be observed in the samples irradiated with dose higher than 3 kGy, suggested that the radiation dose of 3 kGy was enough for sterilization of eyebright raw powders and products. At higher radiation dose of 5 kGy, the moisture and vitamin A content of the samples were insignificantly changed. These mean the radiation treatment with lower dose did not influenced on the quality of eyebright products, and radiation treatment can be applied to prolong the storage of not only eyebright, but also other traditional medicines. (author)

Radiation sterilization of vitamins - studies on the radiolysis and radiation protection of vitamins in aqueous systems and the solid state

International Nuclear Information System (INIS)

Rao, K.N.; Moorthy, P.N.; Kishore, K.

1978-01-01

Radiation sterilization of pharmaceutical products may cause their radiation degradation and loss in their potency. Radiation degradation may even give rise to new products whose effects on the organisms could be different from the parent substances. Extent of radiolytic decomposition of vitamins thiamine, nicotinamide, riboflavine and pyridoxine was studied under controlled conditions so that either only the hydrated electrons (esub(aq)) or only hydrogen atom (H) and hydroxyl radical react with these molecules. Experiments were also conducted in which scavengers for these species were added to reduce radiolytic degradation of the vitamins. It was found that irradiation of vitamins in the frozen aqueous state and with addition of glucose reduces radiolytic degradation and their irradiation in dry solid state causes no detectable damage. The last finding indicates that the best method for radiation sterilization of vitamin preparations may be to irradiate the components in the dry solid state and then compound them together. (M.G.B.)

Basic radiation sterilization properties of packaging materials

International Nuclear Information System (INIS)

Zouharova, A.; Kolarova, J.; Olbrichova, D.

1984-01-01

The foils of various materials were irradiated with 60 Co with an activity of 11,538 TBq. The minimum radiation dose was 25 kGy. Changes in chemico-physical properties were evaluated by infrared spectroscopy and were not detected after irradiation with 25 kGy. Packing foils were subjected to the following tests: mechanical tests, tests of weld strength, tests of impact resistance, free fall tests, permeability tests for water vapour and microbiological tests. The results of all tests were tabulated. The tests showed that the foils are impermeable for microorganisms and provided the welds are airtight the packed products remain sterile. (J.P.)

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.

A Comparative Study of Ethylene Oxide and Radiation Sterilization of Medical Devices

International Nuclear Information System (INIS)

Brewer, J. H.; Keller, G. H.

1967-01-01

Both radiation and gas sterilization have been widely accepted for the ''cold'' sterilization of disposable medical supplies. Each of these methods offers certain advantages over the other but has characteristics which make it less satisfactory for specific items. This study is especially concerned with the effectiveness of various dosage levels and gassing cycles on known concentrations of test organisms, as well as similar studies on routine production lots on which presterilization counts were made. The experimental methods employ techniques which were developed for the National Aeronautics and Space Administration Planetary Quarantine Program and are now standard procedures for the sterilization and microbiological examination of space equipment. The results are much more meaningful than were obtained with techniques employed earlier. Good manufacturing practice and plant hygiene are essential for the practical application of both these sterilization methods in order that chosen dosage levels and cycles will ensure a factor of safety. Manufacturing methods to ensure a low microbiological count are described. Data is presented on the effect of composition of materials on retention and survival of contaminants and die-off of contaminants on handled materials and components before sterilization. Factors concerning the cost-effectiveness of the two methods and other engineering values are discussed. (author)

Microbiological problems of radiation sterilization control of disposable medical products

International Nuclear Information System (INIS)

Horakova, V.

1975-01-01

Dose-response curves were determined for three strains of cocci and seven strains of aerobic spore-forming rods after irradiation by two different 60 Co sources and Van de Graaff electron accelerator. Besides the test strains Streptococcus faecium A 2 1, Bacillus sphericus Csub(I)A and Bacillus pumilus E601, some strains isolated from irradiated vaccines and animal diets, or found among common air-contaminating bacteria and pathogenic cocci were examined. The efficiency of the used radiation sources was compared. The control of the microbiological efficiency of radiation sterilization is discussed regarding routine practice. (author)

Application of ionizing radiation in sterilization of Selasan milk replacer

International Nuclear Information System (INIS)

Olbrichova, D.; Zouharova, A.; Buriankova, E.

1984-01-01

The effect of eight ascending doses of radiation within the range of 3 to 30 kGy on isolated microflora was observed in the milk replacer Selasan with initial contamination 4.9x10 4 germs per 1 gram of preparation. Microorganisms which survived the said radiation dose were evaluated micro and macroscopically. The level of resistance of isolates was determined on the basis of parameters of inactivation curves Nsub(D)=N 0 .esup(-kD). The obtained data served as the basis for determining the minimum sterilization dose 25 kGy for the Selasan replacer. (author)

The effect of radiation sterilization on human transplantable bone

International Nuclear Information System (INIS)

Triantafyllou, N.; Karatzas, P.

1974-11-01

In order to study the effect of radiation sterilization on human transplantable bones, work was carried out on human and bovine bone tissue samples. Factors causing possible alterations in the mechanical structures of the preserved bone allografts were considered to be deep freezing (-35degC), lyophylization, irradiation, or a combination of lyophylization and irradiation. The latter could be shown to lower the mechanical strength of the bone. Crystal lattice of the bone did not show any alterations in x-ray diffraction pattern, following freeze drying and/or irradiation with doses up to 10 Mrad of gamma radiation. Deterioration in mechanical properties is probably due to damage to the organic phase of the bone matrix

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...... of the dosimetric parameters of an irradiation facility. 5. 5. Measurement of absorbed dose distribution in irradiated products. The paper describes these services and the procedures necessary for their execution....

Gamma sterilization of disposable medical products (DMP's)

International Nuclear Information System (INIS)

Brinston, R.M.

1990-01-01

Ten million cubic meters (361 million cubic feet) of disposable medical products (DMP) and related health care items are estimated to be sterilized in the world. In this paper, current conditions and perspectives of gamma sterilization is discussed in comparison with ethylene oxide gas and electron beams. Of the total sterilization estimates for DMP, 2.8 million cubic meters (99 million cubic feet) are sterilized with gamma radiation, with a market share of 27%. Gamma radiation is becoming increased from both general market growth and the introduction of new products, as well as the conversion of product from ethylene oxide gas to cobalt-60. Regulatory pressures, legal considerations, and increasing publicity surrounding ethylene oxide usage are encouraging manufactures to switch to gamma radiation. Gamma's performance features include: no temperature change during the sterilization, high penetration, even through hermetically sealed packages, no residues, and no post-sterilization treatment or quarantine period. Gamma sterilization is economically beneficial in large volumes of product. Cost saving to the end user of gamma sterilization has meant lower minimum dose levels than 25 KGy. Despite of an increasingly accepted gamma radiation, there are still four factors to be considered, including cobalt-60 availability, price, transportation, and disposal. The price of cobalt-60 is based on neutron cost. In the future, cobalt-60 price is expected to be flat and enables gamma processing to become even more competitive with other sterilization methods. Gamma radiation using cobalt-60 has been proven as a safe, effective, and cost-competitive sterilization method for treating DMP and related health care items. It's wide use and many processing advantages will continue to make it a preferred sterilization method. (N.K.)

Materials of 4. Spring School of Radiation Sterilization of Medical Materials, Grafts, Pharmaceutics and Cosmetics

International Nuclear Information System (INIS)

1997-01-01

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

Dose setting for radiation sterilization of disposable medical device, (3)

International Nuclear Information System (INIS)

Iwasaki, Yoshio; Hosobuchi, Kazunari.

1985-01-01

The microbial burden and dose setting for radiation sterilization of tampon for menstrual hygiene were examined, and the following results were obtained. 1. The maximum and minimum contaminants per a tampon were 100 and 0, and the average was 46.1. 2. The 91.2 % of the 125 strains isolated from the tampon was identified as bacilli by the microbiological and biochemical activities, and Bacillus pumilus compried 35.2 % of the strains. B. pumilus and B. megaterium spores indicated the highest radioresistance among those contaminants and both D-values were 0.22 Mrad. 3. The difference in the D-value was not found for the radioresistance of standard strain carried on a tampon and a glass fiber filter. 4. The sterilization dose (SD) was calculated to be 1.10 Mrad by the formula SD = D x log (No/N), while the SD was 0.90 and 0.76 Mrad, respectively, for the microbial burden informations and steility tests. From above ressults, it is supposed that the sterility assurance level in 10 -3 can be achieved by irradiating the dose less than 1 Mrad. (author)

Genetic basis of the sterile insect technique

International Nuclear Information System (INIS)

Robinson, A.S.

2005-01-01

The use of the sterile insect technique (SIT) for insect control relies on the introduction of sterility in the females of the wild population. This sterility is produced following the mating of these females with released males carrying, in their sperm, dominant lethal mutations that have been induced by ionizing radiation. The reasons why the SIT can only be effective when the induced sterility in the released males is in the form of dominant lethal mutations, and not some form of sperm inactivation, are discussed, together with the relationship of dominant lethal mutations to dose, sex, developmental stage and the particular species. The combination of genetic sterility with that induced by radiation is also discussed in relation to the use of genetic sexing strains of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) in area-wide integrated pest management (AW-IPM) programmes that integrate the SIT. A case is made to lower the radiation dose used in such programmes so as to produce a more competitive sterile insect. Increased competitiveness can also be achieved by using different radiation environments. As well as radiation-induced sterility, natural mechanisms can be recruited, especially the use of hybrid sterility exemplified by a successful field trial with tsetse flies Glossina spp. in the 1940s. Genetic transformation will make some impact on the SIT, especially regarding the introduction of markers for released flies, and the construction of genetic sexing strains. It is concluded that using a physical process, such as radiation, will always have significant advantages over genetic and other methods of sterilization for the large-scale application of the SIT. (author)

Histological and genetic studies on the male sterile mutants of tomato induced by gamma radiation and chemical mutagens

Energy Technology Data Exchange (ETDEWEB)

Choi, J K [Office of Rural Development, Suwon (Republic of Korea) Horticultural Experiment Station

1976-03-01

The object of this experiment was to test the radiosensitivity of the M/sub 1/ generation, and to determine the inheritance and morphological characteristics of the male-sterile mutants in tomatoes. The results obtained are as follows: Radiation damage varied with the water content of the seeds. The least damage occurred in the range of 11.34 to 14.29 percent moisture. Four tomato cultivars were gamma irradiated. The cultivar Sekai-ichi was the most sensitive while the other responded similarly to each other. Chemical mutagen treatments caused greater damage to germination, to delayed flowering and to pollen fertility than did radiation. Pollen fertility and seeds per fruit in seedling gamma irradiated plants decreased as the dosage and dose rate increased. Five male-sterile mutants were found. Each was controlled by a single recessive gene. All five male-steriles were nonallelic. Floral sized of the male-sterile mutants were slightly smaller. Ovule fertility varied, usually being lower than normal type. Male sterility varied, usually being lower than normal type. Male sterility in 109-1ms strain was caused by unbalanced, insufficient nutrients being made available to the pollen-mother cells from the tapetal tissued. (author).

Combined effect of heat sterilization and ionizing radiation on folacin in canned food

International Nuclear Information System (INIS)

Hozova, B.; Sorman, L.

1986-01-01

The results are reported of a study in folacin changes following heat sterilization at reduced intensity combined with irradiation of model food products, such as pickled cauliflower and beef in gravy. The folacin content in cauliflower was found to vary with the intensity of heat sterilization; no significant effect was observed of varying radiation doses. With respect to beef in gravy, the study confirmed the suitability of the combined preservation process in view of the higher folacin retention in the given food type. (author). 3 tabs., 14 refs

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......, forming a pit, and continues parallel to the bone surface, forming a trench. Importantly, we show that the progress of the osteoclast along this route depends on the balance between the rate of collagenolysis and demineralization. We propose that the osteocytes and bone lining cells surrounding...... the osteoclast may act on this balance to steer the osteoclast resorptive activity in order to give the excavations a specific shape....

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.

Mechanical analysis of bone rulers sterilized by gamma radiation for use in tissue banks

International Nuclear Information System (INIS)

Kosmiskas, Luis Otavio Carvalho

2007-01-01

In the production process of health care products, contamination must be considered as one of the principal hazards to be avoided. Among the developed methods for sterilization, ionizing radiation has largely been used by many sectors in health care area as it is efficient in eliminating biological contaminants of several origins. The difficulty of deploying ionizing radiation in materials of human origin, though, includes which possible alterations it might cause in human tissue. In the present work, the extension of the bio mechanical alteration generated by radiation in bone tissue was evaluated by bio mechanical methods. More specifically, we evaluated alterations to the elastic modulus, rupture tension and percentage of deformation that are thought to be a consequence of the sterilization process. As a research model, bovine femur struts obtained from the diaphysis were used. The struts were frozen in a temperature of -70 deg C and irradiated with crescent doses of gamma radiation (0, 12.5, 25 e 50 kGy). During this work, a cutting system to obtain precision samples to use in such essays was developed. As results show that there is a significant different between the analyzed characteristics in the different doses of radiation. (author)

Guidelines for industrial radiation sterilization of disposable medical products (Cobalt-60 gamma irradiation)

International Nuclear Information System (INIS)

1990-01-01

This IAEA document is aimed at providing necessary guidance on standards and criteria and assistance to Member States, particularly developing countries, in their attempts to properly set up facilities for industrial radiation sterilization of duly-manufactured medical products by exposure to Co-60 gamma radiation. The contents of the guidelines have therefore been designed, as far as practicable, to reflect the practices and procedures currently employed in the processing of the majority of the radiation-sterilized medical products being produced worldwide. Consequently, this document has attempted to present to its users, for information and for action, all the relevant features of the standard criteria as are currently in existence under the auspices of the various authoritative national and/or regional Codes or Guides. The potential user(s) from Member States are expected to freely decide which of the various standards as enumerated in the Guidelines document should be considered for inclusion or exclusion either partially or totally in the context of the formulation of their own nationally-acceptable guidelines. Refs and tabs

Radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods

International Nuclear Information System (INIS)

Garrison, W.M.

1981-12-01

An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides, and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the α,α'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The α,α'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and bacterial products. All of the available data strongly suggest that the α,α'-diamino acids are produced in significant yield in the radiation sterilization of high protein foods. The importance of initiating extensive chemical and biological studies of these and of other high molecular weight products in irradiated food is emphasized

Radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods

International Nuclear Information System (INIS)

Garrison, W.M.

1979-03-01

An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the α,α'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The α,α'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and pathogenic toxins. All of the available data strongly suggest that the α,α'-diamino acids are produced in significant yield in the radiation sterilization of high protein foods. The importance of initiating extensive chemical and biological studies of initiating extensive chemical and biological studies of these and of other high molecular weight products in irradiated food is emphasized

Radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods

Energy Technology Data Exchange (ETDEWEB)

Garrison, W. M.

1981-12-01

An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides, and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the ..cap alpha..,..cap alpha..'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The ..cap alpha..,..cap alpha..'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and bacterial products. All of the available data strongly suggest that the ..cap alpha..,..cap alpha..'-diamino acids are produced in significant yield in the radiation sterilization of high protein foods. The importance of initiating extensive chemical and biological studies of these and of other high molecular weight products in irradiated food is emphasized.

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.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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.

In vitro demineralization of tooth enamel subjected to two whitening regimens.

Science.gov (United States)

Ogura, Kayoko; Tanaka, Reina; Shibata, Yo; Miyazaki, Takashi; Hisamitsu, Hisashi

2013-07-01

The resistance of bleached enamel to demineralization has not been elucidated fully. In this study, the authors aimed to examine the level of in vitro demineralization of human tooth enamel after bleaching by using two common bleaching regimens: home bleaching (HB) and office bleaching (OB) with photoirradiation. The authors bleached teeth to equivalent levels by means of the two bleaching regimens. They used fluorescence spectroscopy to measure the reduction in enamel density and the release of calcium into solution after storing the treated teeth in a demineralizing solution for two weeks. They also visualized and quantified mineral distribution in demineralized bleached enamel over time by using a desktop microcomputed-tomographic analyzer. Enamel subjected to HB or to photoirradiation without bleaching showed increased demineralization. In contrast, enamel treated with OB was more resistant to demineralization. This resistance to demineralization in teeth treated with OB presumably is due to peroxide's permeating to deeper layers of enamel before being activated by photoirradiation, which enhances mineralization. The mineral distribution pattern of enamel after treatment plays a critical role in providing resistance to demineralization in whitened teeth. OB confers to enamel significant resistance to in vitro demineralization. Dentists should supervise the nightguard HB process.

Handling technique of spore-forming bacteria in radiation sterilization. 1. Preparation of spores

International Nuclear Information System (INIS)

Koshikawa, Tomihiko

1994-01-01

This paper deals with a handling technique of spore-forming bacteria in radiation sterilization. An explanation is given under three sections: (1) life cycle of spore-forming bacteria, medium to form bacterial spores, and colony and purification methods of bacterial spores; (2) methods for measuring the number of bacterial spores and resistance against gamma radiation (D values); and (3) a test method for identifying spore-forming bacteria and a simple identification method. (N.K.)

Determination of sterilizing dose of lincocine drug

International Nuclear Information System (INIS)

Adawi, M.A.; Shamma, M.; Al-Mousa, A.

1998-01-01

There are too many antibiotics that have been studied on their dry solid state to determine their safe sterilizing dose by decreasing their bio burden in order to reach the sterility assurance level (SAL) needed. The sterilizing radiating dose of lincocine was determined according to information about their bio burden and radiating sensitivity at the sterility assurance level 10-6. The study of bio burden has shown that the contamination was fungal (Pemicillium sp.) and by applying the same tests to the raw materials of lincocine it came out that the cause of contamination was bad storage and that the radiating dose required to decrease the bio burden was 5.5 kGy. (author)

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

International Nuclear Information System (INIS)

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.

2011-01-01

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 60 Co source. Surviving spores were counted and used to estimate the decimal reduction (D 10 ) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10 5 -9x10 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 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. - 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.

Anti-microorganism contamination measures for crude drugs utilizing radiation sterilization

International Nuclear Information System (INIS)

Kimura, Syojiro

1998-01-01

Crude drugs are manufactured by simple processing of natural mineral, animal or plant part materials, and are used in Chinese medicine. Because these components are originated by nature, they tend to have a much higher level of contaminating microorganisms than chemically synthesized compound. Many plant-derived crude drugs contain bacteria; 10 3 -10 5 cells/g and fungi; 10 2 -10 4 spores/g. Some animal-derived crude drugs contain bacteria levels of up to 10 8 cells/g, including dangerous varieties like E. coli or Salmonella. The survival rate and the required dose can be quantified as follows: N/No=e -kD and SD=D 10 x log (No/SAL), respectively. Where, k is the sterilization constant of microorganism, No is the initial count of bacteria, D is the absorbed dose, D 10 is the dose required to decrease the count to 1/10 and SAL is the count limit or sterilization assurance. The D 10 value for general microorganism is approximately 2 kGy for bacteria, 1 kGy for fungi, and 3-4 kGy for spore-forming bacteria. The results of our past studies have shown that the dose of 5-7 kGy is necessary to sterilize general microorganism that are attached to crude drugs. Besides, the D 10 value of specific bacteria ranges from 0.1 to 0.8 kGy, so the above dose should be sufficient for sterilizing the specific microorganism (SAL; 10 -6 ). The stability of crude drugs can be quantified be the following formula, C/Co=e -k'D . Where, C/Co is the residual rate of drug components, and k' is the loss coefficient. The value of k is 1-2, but that of k' is three to four figures smaller. The C/Co ratio of most drug components is more than 0.99 with a dose of 5-7 kGy. Furthermore, radiolysis materials that are decomposed by radiation are similar to compounds that are decomposed by ultraviolet rays or sunlight. 60 Co ray are suitable for sterilizing raw materials. On the other hand, electron beams are used to sterilize a thin layer of pulverized specimens, and can be incorporated into the

Sewage sterilization through gamma radiation; Esterilização de esgoto através da radiação gama

Energy Technology Data Exchange (ETDEWEB)

Vieira, D.V.; Teixeira, W.M.S. [Faculdade Casa Branca, SP (Brazil). Pós-Graduação de Proteção Radiológica em Aplicações Médicas, Industriais e Nucleares; Lima, C.M.A. [MAXIM Cursos, Rio de Janeiro-RJ (Brazil); Silva, F.C.A. da, E-mail: franciscodasilva13uk@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Riode Janeiro, RJ (Brazil)

2017-07-01

Lack of sewage treatment and adequate sanitation conditions can contribute to the proliferation of numerous parasitic and infectious diseases in addition to water degradation. Approximately fifty types of infections can be transmitted from a sick to a healthy person through different pathways involving human excreta. Untreated sewage can contaminate water, food, hands, soil, etc. Epidemics of certain diseases such as typhoid, cholera, dysenteries, etc., and countless cases of worms are responsible for high mortality rates in third world countries. In the work the different techniques of sewage treatment by disinfestation and sterilization were analyzed, highlighting the use and the advantages of the gamma radiation as well as the aspects of the radiological protection involved. The technique of sewage sterilization using gamma radiation is a method of controlling bacteria and microorganisms. It is estimated that more than 200 large irradiators are in operation worldwide, of which 5 are in Brazil, for general sterilization use. These facilities use a large amount of radioactive material, in the order of millions of Becquerel, for sterilization with high doses of radiation, which can generate lethal doses in a few minutes. These industrial facilities use Cobalt-60, being classified by the International Atomic Energy Agency - IAEA as Category 1 of high risk, and must possess a high level of radiological protection to carry out the sterilization, standing out the defense in depth. Specific legislation on radiological protection should be drafted for safe work and avoid future radiation accidents.

Challenges in validating radiation sterilization with low energy electron irradiation

International Nuclear Information System (INIS)

Miller, A.; Helt-Hansen, J.

2011-01-01

Complete text of publication follows. Low energy electron irradiation (80-300 keV) is used increasingly for sterilization or decontamination in connection with isolators for aseptic filling lines in the pharmaceutical industry. It is not defined how validation for this process shall be carried out. A method can be derived from the medical device standard for radiation sterilization, ISO 11137, because the principles described in this standard can be applied to almost any industrial irradiation process. The validations elements are: Process definition, concerning specification of the dose required for the process and the maximum acceptable dose for the product. Installation qualification, concerning acceptance the irradiation facility. Operational qualification, concerning characterization of the facility. Performance qualification, concerning setting up the process. Process control, concerning routine monitoring. The limited penetration of the low energy electrons leads to problems with respect to executing these validation steps. This paper discusses these problems, and shows with examples how they can be solved.

Use of sterile insect technique in Brazil by the sterilization of Ceratitis capitata (Wied., 1824)

International Nuclear Information System (INIS)

Okeese, G.O.; Kitomer, T.J.; Gayaradus, L.B.; Etrigan, M.; Jansen, C.W.J.H.; Houlahar, H.L.

2006-01-01

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 60 Co or 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 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)

Ultraviolet radiation for the sterilization of contact lenses

International Nuclear Information System (INIS)

Gritz, D.C.; Lee, T.Y.; McDonnell, P.J.; Shih, K.; Baron, N.

1990-01-01

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally affected by exposure to 300 hours of UV-B. Ultraviolet light is an effective germicidal agent but is injurious to soft lens polymers; its possible utility in the sterilization of RGP lenses and lens cases deserves further study

Cytological study of radiation induced alterations in cytoplasmic factors controlling male sterility in corn. Progress report, February 28, 1975--December 1, 1975

International Nuclear Information System (INIS)

Edwardson, J.R.

1975-01-01

Progress is reported on the following research projects: cytoplasmic constituents of the embryo of various gymnosperms and angiosperms; cytoplasmic male sterility in corn; modification of cytoplasmic sterility factors using gamma radiation, EMS, and ethidium bromide; selection for sterile, blight-resistant corn plants; electron microscopy study of abnormal mitochondria in cytoplasm of corn; cytoplasmic male sterility in Petunia; non-Mendelian variegation in Petunia and Nicotiana; graft transmission of cytoplasmic male sterility; cytoplasmic male sterility in Vicia faba; and studies on Blakeslee's I virus in Datura

Shelf life prediction of radiation sterilized polymeric materials

International Nuclear Information System (INIS)

Sandford, Craig; Woo, Lecon

1988-01-01

The functional properties of many polymers employed in medical disposables are unaffected by sterilizing doses of ionizing radiation. However, some materials (PVC, polypropylene, cellulosics, etc.) undergo undesirable changes which continue to occur for the shelf life of the product. In many cases, conventional accelerated aging techniques do not accurately predict the real time properties of the materials. As real time aging is not generally practical, it has become necessary to develop accelerated aging techniques which can predict the functional properties of a material for the shelf life of the product. This presentation will address issues involved in developing these tests. Real time physical property data is compared to data generated by various acceleration methods. (author)

Sterilization of spices and vegetable seasoning by gamma radiation

International Nuclear Information System (INIS)

Lescano, G.; Narvaiz, P.; Kairiyama, E.

1991-01-01

Ginger, turmeric, Cayenne pepper, onion and garlic powders were gamma irradiated with doses of 10 and 30 kGy, and stored at room temperature for six months. Microbiological, chemical and sensory analyses were performed. Samples were sterilized with 30 kGy. The pH values of water extracts of these condiments appear practically unchanged by the applied gamma radiation doses. Spectrophotometric analysis of methyl alcohol extracted of the pigments showed no irradiation effect in turmeric and ginger. Seasoning capacity (odour, flavour and pungency) were not altered by 30 kGy irradiation. (author) 24 refs.; 2 figs.; 4 tabs

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.

Radiosterilization or sterilization by steam. Procedures for sterilization of spices

International Nuclear Information System (INIS)

Warmbold, J.

1994-01-01

The article compares two different methods for the sterilization of spices, namely radiosterilization and sterilization with steam. The first method applies ionizing radiation which can alter the chemical composition of the products. Tests have shown, however, that radiation doses up to 10 kGy will not induce the formation of carcinogenic agents in the foodstuffs, or of toxic substances, and thus are a wholesome method of preservation. Any modifications of taste, color or smell, or loss of vitamins, can be avoided by proper dose control and standard irradiation conditions. Sterilization by steam is a method achieving substantial suppression of the formation of germs, aerobic spores, yeasts, mould, and gramnegative germs, while preserving in most cases the essential oils. It may result in sensoric alterations, i.e affect the color, smell or taste, but in general the spices thus treated preserved their characteristic properties. The method is a good alternative to radiosterilization. The article adds some concluding information on mandatory labelling of irradiated food imported from third countries

Responses to gamma radiation of selected microorganisms in sterile water and bovine muscle

International Nuclear Information System (INIS)

Dempster, J.F.; Halls, N.A.

1986-01-01

The responses to gamma-radiation of a number of food-associated microorganisms (Staphylococcus aureus, Yersinia enterocolitica, Pseudomonas putrefaciens) were studied in sterile distilled water and sterile bovine muscle slurry. Surviving cells were grown aerobically at room temperature on yeast extract dextrose tryptone agar (PCA, Oxoid). The D 1 0 of the Pseudomonas sp. was 27 Gy in water and the D 1 0 of the Yersinia sp. in water was 32 Gy. In the slurry resistance increased markedly; the Pseudomonas sp. was ten times more resistant (D 1 0 260 Gy) and the Yersinia sp. was seven times more resistant (D 1 0226 Gy). The Staph. aureus was equally sensitive in both systems (author)

Male gametophytic sterility. 1 - Gametic sterilities and deletions in petunia

Energy Technology Data Exchange (ETDEWEB)

Cornu, A.; Maizonnier, D. (Station d' Amelioration des Plantes de l' I.N.R.A., Dijon (France))

1982-01-01

Terminal deletions induced by ionizing radiations in Petunia are not sexually transmitted. Cytogenetic study of plants with a heterozygous deletion and their progenies shows that this lack of transmission is accompanied by a gametic semi-sterility due to the fact that gametes carrying the deleted chromosome are not viable. The interest of such a male sterility with a gametophytic determinism for the study of sporophyte-gametophyte relationships is underlined.

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.

Clinical use of radiation sterile porcine skin and Ag-skin of porcine

International Nuclear Information System (INIS)

Zhu Xiaobo

1995-01-01

Clinical examination revealed that either radiation sterilized skin or Ag-skin of pig are effective biologic dressing. When used as temporary skin coverage for fresh burn wound, for wound after escharectomy, and for wounds among skin grafts, they are effective in preventing infection and loss of body fluid. They can also be used for covering the infected granulation wound to control bacterial growth and further contamination

The use of bacteriological preparates to test processes in radiation sterilization

International Nuclear Information System (INIS)

Gazso, L.; Igali, S.; Kovacs, A.

1976-01-01

Environmental factors influencing the irradiation sensitivity of micro-organisms, bacterium stocks being suitable for biological checking up and spore test organism used nowadays are reviewed. According to the tests made on Bacillus pumilus E601 and Bacillus sphaericus Csub(I)A stockes with Noratom, PX-γ-30 and 60 Co radiation sources the irradiation sensitivity of the same products irradiated with the same dose can differ in the function of the radiation source and the dose rate. It seems necessary to produce the test preparates in the same way in a central laboratory and to calibrate them to single radiation sources. It is advisable to check up the factual microbicidal effect of the nominal dosage by a biological dosimeter. The method reviewed potentiates a much higher confidence than that of conventional sterility tests and its additional advantage is the cheapness. (K.A.)

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.)

Maria Sklodowska Curie - the precursor of radiation sterilization methods

International Nuclear Information System (INIS)

Gluszewski, Wojciech; Zagorski, Zbigniew P.; Tran, Quoc Khoi; Cortella, Laurent

2011-01-01

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.)

Radiation Fusion Technology for Sewage Sterilization

International Nuclear Information System (INIS)

Lee, M. J.; Kim, T. H.; Ryu, S. H.; Jung, I. H.; Lee, O. M.; Kim, T. H.

2011-01-01

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

Dark radiation sterile neutrino candidates after Planck data

Energy Technology Data Exchange (ETDEWEB)

Valentino, Eleonora Di; Melchiorri, Alessandro [Physics Department and INFN, Università di Roma ' ' La Sapienza' ' , Ple Aldo Moro 2, 00185, Rome (Italy); Mena, Olga, E-mail: eleonora.divalentino@roma1.infn.it, E-mail: alessandro.melchiorri@roma1.infn.it, E-mail: omena@ific.uv.es [IFIC, Universidad de Valencia-CSIC, 46071, Valencia (Spain)

2013-11-01

Recent Cosmic Microwave Background (CMB) results from the Planck satellite, combined with previous CMB data and Hubble constant measurements from the Hubble Space Telescope, provide a constraint on the effective number of relativistic degrees of freedom 3.62{sup +0.50}{sub −0.48} at 95% CL. New Planck data provide a unique opportunity to place limits on models containing relativistic species at the decoupling epoch. We present here the bounds on sterile neutrino models combining Planck data with galaxy clustering information. Assuming N{sub eff} active plus sterile massive neutrino species, in the case of a Planck+WP+HighL+HST analysis we find m{sub ν,} {sub sterile}{sup eff} < 0.36 eV and 3.14 < N{sub eff} < 4.15 at 95% CL, while using Planck+WP+HighL data in combination with the full shape of the galaxy power spectrum from the Baryon Oscillation Spectroscopic Survey BOSS Data Relase 9 measurements, we find that 3.30 < N{sub eff} < 4.43 and m{sub ν,} {sub sterile}{sup eff} < 0.33 eV both at 95% CL with the three active neutrinos having the minimum mass allowed in the normal hierarchy scheme, i.e. ∑m{sub ν} ∼ 0.06 eV. These values compromise the viability of the (3+2) massive sterile neutrino models for the parameter region indicated by global fits of neutrino oscillation data. Within the (3+1) massive sterile neutrino scenario, we find m{sub ν,} {sub sterile}{sup eff} < 0.34 eV at 95% CL. While the existence of one extra sterile massive neutrino state is compatible with current oscillation data, the values for the sterile neutrino mass preferred by oscillation analyses are significantly higher than the current cosmological bound. We review as well the bounds on extended dark sectors with additional light species based on the latest Planck CMB observations.

The male gametophytic sterility. 1 - Gametic sterilities and deletions in petunia

International Nuclear Information System (INIS)

Cornu, A.; Maizonnier, D.

1982-01-01

Terminal deletions induced by ionizing radiations in Petunia are not sexually transmitted. Cytogenetic study of plants with a heterozygous deletion and their progenies shows that this lack of transmission is accompanied by a gametic semi-sterility due to the fact that gametes carrying the deleted chromosome are not viable. The interest of such a male sterility with a gametophytic determinism for the study of sporophyte-gametophyte relationships is underlined [fr

Radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods. [106 references

Energy Technology Data Exchange (ETDEWEB)

Garrison, W.M.

1979-03-01

An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the ..cap alpha..,..cap alpha..'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The ..cap alpha..,..cap alpha..'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and pathogenic toxins. All of the available data strongly suggest that the ..cap alpha..,..cap alpha..'-diamino acids are produced in significant yield in the radiation sterilization of high protein foods. The importance of initiating extensive chemical and biological studies of initiating extensive chemical and biological studies of these and of other high molecular weight products in irradiated food is emphasized.

Impact of a Disposable Sterile Radiation Shield on Operator Radiation Exposure During Percutaneous Coronary Intervention of Chronic Total Occlusions.

Science.gov (United States)

Shorrock, Deborah; Christopoulos, Georgios; Wosik, Jedrek; Kotsia, Anna; Rangan, Bavana; Abdullah, Shuaib; Cipher, Daisha; Banerjee, Subhash; Brilakis, Emmanouil S

2015-07-01

Daily radiation exposure over many years can adversely impact the health of medical professionals. Operator radiation exposure was recorded for 124 percutaneous coronary interventions (PCIs) performed at our institution between August 2011 and May 2013: 69 were chronic total occlusion (CTO)-PCIs and 55 were non-CTO PCIs. A disposable radiation protection sterile drape (Radpad; Worldwide Innovations & Technologies, Inc) was used in all CTO-PCI cases vs none of the non-CTO PCI cases. Operator radiation exposure was compared between CTO and non-CTO PCIs. Mean age was 64.6 ± 6.2 years and 99.2% of the patients were men. Compared with non-CTO PCI, patients undergoing CTO-PCI were more likely to have congestive heart failure, to be current smokers, and to have longer lesions, and less likely to have prior PCI and a saphenous vein graft target lesion. CTO-PCI cases had longer procedural time (median: 123 minutes [IQR, 85-192 minutes] vs 27 minutes [IQR, 20-44 minutes]; P<.001), fluoroscopy time (35 minutes [IQR, 19-54 minutes] vs 8 minutes [IQR, 5-16 minutes]; P<.001), number of stents placed (2.4 ± 1.5 vs 1.7 ± 0.9; P<.001), and patient air kerma radiation exposure (3.92 Gray [IQR, 2.48-5.86 Gray] vs 1.22 Gray [IQR, 0.74-1.90 Gray]; P<.001), as well as dose area product (267 Gray•cm² [IQR, 163-4.25 Gray•cm²] vs 84 Gray•cm² [IQR, 48-138 Gray•cm²]; P<.001). In spite of higher patient radiation exposure, operator radiation exposure was similar between the two groups (20 μSv [IQR, 9.5-31 μSv] vs 15 μSv [IQR, 7-23 μSv]; P=.07). Operator radiation exposure during CTO-PCI can be reduced to levels similar to less complicated cases with the use of a disposable sterile radiation protection shield.

Effect of γ-radiation sterilization on the stability of polyurethane potting compounds based on castor oil/SMDI and caprolactone polyol/SMDI, used for hollow fibre haemodialyzer

International Nuclear Information System (INIS)

Jayabalan, M.; Lizymol, P.P.

1997-01-01

Stability of polyurethane potting compounds based on castor oil/SMDI and caprolactone polyol/SMDI in repeated gamma radiation sterilization was studied. Radiation-induced degradation and leaching of low molecular weight fragments are higher in castor oil based polyurethane than in caprolactone polyol based polyurethane. For castor oil and caprolactone polyol based polyurethanes degradation increases up to 5 Mrad dose of sterilization. Further increase of dose of sterilization decreases leaching in caprolactone polyol based polyurethane which has resulted from secondary reactions leading to crosslinking. In the case of castor oil based polyurethane such crosslinks undergo cleavage at 10 Mrad dose of sterilization. (author)

Evaluation of Lepidoptera population suppression by radiation induced sterility. Proceedings of a final research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-04-01

This publication results from the second FAO/IAEA Research Co-ordination Project (CRP) on Inherited Sterility in Lepidoptera (caterpillars of moths). The present CRP and a previous one entitled 'Radiation Induced F{sub 1} Sterility in Lepidoptera for Area-Wide Control' were initiated in response to requests from Member States for the development of environment friendly alternatives to current control of moth pests. The first five-year CRP (1987-1991) dealt primarily with aspects such as determining the effects of various radiation dose levels on the resulting sterility in the treated parents and their F{sub 1} progeny in different Lepidoptera species. In addition, models were developed on the suppressive effects of F{sub 1} sterility on field populations, and some studies were conducted in laboratory or field cages to assess the impact of inherited sterility on pest suppression. The research results were published in 1993 in the IAEA Panel Proceedings Series. This follow-up CRP (1994-1998) has built on the results of the first CRP and has focused on addressing a more challenging phase, consisting of rearing key pest moths and evaluating their application for pest control purposes. The specific objective of the CRP was therefore to assess the potential of suppressing populations of caterpillar pests in the field by inherited sterility methods, i.e. by rearing and releasing irradiated moths and/or their progeny in combination with other biological control methods. The ultimate goal is to have alternative environment-friendly control methods available to be able to reduce the vast quantities of insecticide that are used in agriculture to combat Lepidoptera pests and that adversely affect the trade balance of developing countries because they must use hard currency to import them. The two FAO/IAEA sponsored Lepidoptera CRPs have resulted in expanded research and implementation programmes on F{sub 1} sterility in combination with natural enemies. Such programmes are

Evaluation of Lepidoptera population suppression by radiation induced sterility. Proceedings of a final research co-ordination meeting

International Nuclear Information System (INIS)

2002-04-01

This publication results from the second FAO/IAEA Research Co-ordination Project (CRP) on Inherited Sterility in Lepidoptera (caterpillars of moths). The present CRP and a previous one entitled 'Radiation Induced F 1 Sterility in Lepidoptera for Area-Wide Control' were initiated in response to requests from Member States for the development of environment friendly alternatives to current control of moth pests. The first five-year CRP (1987-1991) dealt primarily with aspects such as determining the effects of various radiation dose levels on the resulting sterility in the treated parents and their F 1 progeny in different Lepidoptera species. In addition, models were developed on the suppressive effects of F 1 sterility on field populations, and some studies were conducted in laboratory or field cages to assess the impact of inherited sterility on pest suppression. The research results were published in 1993 in the IAEA Panel Proceedings Series. This follow-up CRP (1994-1998) has built on the results of the first CRP and has focused on addressing a more challenging phase, consisting of rearing key pest moths and evaluating their application for pest control purposes. The specific objective of the CRP was therefore to assess the potential of suppressing populations of caterpillar pests in the field by inherited sterility methods, i.e. by rearing and releasing irradiated moths and/or their progeny in combination with other biological control methods. The ultimate goal is to have alternative environment-friendly control methods available to be able to reduce the vast quantities of insecticide that are used in agriculture to combat Lepidoptera pests and that adversely affect the trade balance of developing countries because they must use hard currency to import them. The two FAO/IAEA sponsored Lepidoptera CRPs have resulted in expanded research and implementation programmes on F 1 sterility in combination with natural enemies. Such programmes are under way in Tunisia

Radiation sterilization of medical supplies: conceptions, regulations, present status and further developments

International Nuclear Information System (INIS)

Peteu, Gh.

1994-01-01

A general view on the present stage and tendencies in the development of radiation sterilization of biomedical supplies is presented. Specific concepts in correlation with some regulations of the World Health Organization and of the National Public Health Authorities concerning the present state, the possibilities and criteria of development in our country, are discussed. Finally the present status of the design and execution of the project of two mobile and multipurpose irradiators is presented. (Author)

Bone protein extraction without demineralization using principles from hydroxyapatite chromatography.

Science.gov (United States)

Cleland, Timothy P; Vashishth, Deepak

2015-03-01

Historically, extraction of bone proteins has relied on the use of demineralization to better retrieve proteins from the extracellular matrix; however, demineralization can be a slow process that restricts subsequent analysis of the samples. Here, we developed a novel protein extraction method that does not use demineralization but instead uses a methodology from hydroxyapatite chromatography where high concentrations of ammonium phosphate and ammonium bicarbonate are used to extract bone proteins. We report that this method has a higher yield than those with previously published small-scale extant bone extractions, with and without demineralization. Furthermore, after digestion with trypsin and subsequent high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis, we were able to detect several extracellular matrix and vascular proteins in addition to collagen I and osteocalcin. Our new method has the potential to isolate proteins within a short period (4h) and provide information about bone proteins that may be lost during demineralization or with the use of denaturing agents. Copyright © 2014 Elsevier Inc. All rights reserved.

DEMINERALIZATION OF HUMAN DENTIN COMPARED WITH ENAMEL IN A PH-CYCLING APPARATUS WITH A CONSTANT COMPOSITION DURING DE-MINERALIZATION AND REMINERALIZATION PERIODS

NARCIS (Netherlands)

HERKSTROTER, FM; WITJES, M; ARENDS, J

1991-01-01

A comparison was made between the demineralization of enamel and dentine with and without abraded surfaces. This was done in a pH-cycling experiment for different demineralization/remineralization ratios - in the range from 1:1 to 1:4 - and for different fluoride additions (up to 2 ppm) in solution.

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

KAUST Repository

Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Amy, Gary L.; Van Dijk, Johannis C.

2012-01-01

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.

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.

Twenty years of radiation sterilization in Croatia

Science.gov (United States)

Ražem, Dus̆an

2004-09-01

The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m 3 kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m 3 kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made.

Twenty years of radiation sterilization in Croatia

International Nuclear Information System (INIS)

Razem, Dusan

2004-01-01

The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m 3 kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m 3 kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made

Twenty years of radiation sterilization in Croatia

Energy Technology Data Exchange (ETDEWEB)

Razem, Dusan E-mail: razem@irb.hr

2004-10-01

The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m{sup 3} kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m{sup 3} kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made.

Demineralization-remineralization dynamics in teeth and bone.

Science.gov (United States)

Abou Neel, Ensanya Ali; Aljabo, Anas; Strange, Adam; Ibrahim, Salwa; Coathup, Melanie; Young, Anne M; Bozec, Laurent; Mudera, Vivek

Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization-remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide.

Radiation sterilization of potato starch and Sedonik

International Nuclear Information System (INIS)

Tashmetov, M.Yu.; Ismatov, N.B.; Saidov, R.P. et al.

2016-01-01

The raw material of pharmaceutical preparations potato starch and sedative means of Sedonik are sterilized at the electron's accelerator Electronics U-003. It is established that at 20.3 kGy absorbed dose and electron's energy 3 - 5 MeV the results of microbiological analysis showed sterility of potato starch and Sedonik and correspondence of their physical-optical properties to the requirements of normative documents. (authors)

Induction of sterility in Anastrepha Fraterculus (Diptera: Tephritidae) by gamma radiation

International Nuclear Information System (INIS)

Allinghi, A.; Gramajo, C.; Willink, E.; Vilardi, J.

2007-01-01

In relation to the application of the sterile insect technique (SIT) for the South American fruit fly Anastrepha fraterculus (Wiedemann), we analyzed the effect on adult fertility of different doses of gamma irradiation and the age of pupae at the time of irradiation. In a first experiment, we applied doses of 50, 70, and 90 Gy to pupae at 24, 48, 72, and 96 h before adult emergence. In a second experiment we irradiated pupae 48 h before emergence with 20, 40, and 60 Gy and estimated male and female fertility and sperm transfer by irradiated males. The results indicated pupal age at irradiation does not significantly affect male fertility. If males irradiated with 60 Gy are crossed to non-irradiated females the fertility is about 1%. Females irradiated with 40 Gy did not lay eggs independently of the male to which they mated. No significant effects of radiation were observed with respect to the ability of males to transfer sperm. A dose of 70 Gy applied 48 h before adult emergence induces 100% sterility in both males and females. (author) [es

Microbiological aspects relating to the choice of radiation sterilization dose

International Nuclear Information System (INIS)

Whitby, J.L.

1993-01-01

Ionizing radiation is widely used for sterilization of single-use medical devices, and it is employed for its lethal effect on microbial life. Microbes are capable of regenerating from a single surviving cell, and individual cells of some microbial species are highly resistant to the lethal effects of radiation. It is necessary to employ radiation doses far in excess of those lethal to man or animals to ensure that no viable microbe remains to repopulate the device or the patient at the time that the device is used. Ionizations induce the production of short-lived free radicals that also induce lethal changes in cells. The sensitivity of microbial species to these changes varies markedly but since the changes are induced within the cell, each cell has to sustain the necessary amount of lethal damage before death will occur. Therefore the death of cells will occur in the exponential mode the surviving fraction decreasing with increasing dose. Using a semi-logarithmic plot, curves of three types may be generated, a simple exponential curve with a constant slope over the whole dose range, one where an initial shoulder is followed by a constant slope, and curves which are concave, and only seen in mixed bacterial populations of differing radiation resistance. (author)

Sterile insect technique: A model for dose optimisation for improved sterile insect quality

International Nuclear Information System (INIS)

Parker, A.; Mehta, K.

2007-01-01

The sterile insect technique (SIT) is an environment-friendly pest control technique with application in the area-wide integrated control of key pests, including the suppression or elimination of introduced populations and the exclusion of new introductions. Reproductive sterility is normally induced by ionizing radiation, a convenient and consistent method that maintains a reasonable degree of competitiveness in the released insects. The cost and effectiveness of a control program integrating the SIT depend on the balance between sterility and competitiveness, but it appears that current operational programs with an SIT component are not achieving an appropriate balance. In this paper we discuss optimization of the sterilization process and present a simple model and procedure for determining the optimum dose. (author) [es

Probabilistic model for sterilization of food

International Nuclear Information System (INIS)

Chepurko, V.V.; Malinovskij, O.V.

1986-01-01

The probabilistic model for radiation sterilization is proposed based on the followng suppositions: (1) initial contamination of a volume unit of the sterilized product m is described by the distribution of the probabilities q(m), (2) inactivation of the population from m of microorganisms is approximated by Bernoulli test scheme, and (3) contamination of unit of the sterilized product is independent. The possibility of approximation q(m) by Poisson distribution is demonstrated. The diagrams are presented permitting to evaluate the dose which provides the defined reliability of sterilization of food for chicken-gnotobionts

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

OpenAIRE

Sabel, N.; Robertson, A.; Nietzsche, S.; Norén, J. G.

2012-01-01

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 an...

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 ...

Sterilization of fruit flies (Diptera: Tephritidae) with X-rays for sterile insect technique programs

International Nuclear Information System (INIS)

Mastrangelo, Thiago de Araujo

2009-01-01

Recent fear of acts of terrorism provoked an increase of delays and denials in the shipment of radioisotopes. This truly represented a menace to sterile insect production projects around the world. In order to validate the use of a new kind of low-energy Xray irradiator, a series of radiobiological studies on Ceratitis capitata (tsl-VIENNA 8 strain) (Wied., 1824) (Diptera: Tephritidae) and an Argentinean strain of Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) were carried out, also comparing biological effectiveness between X-rays and traditional γ radiation from 60 Co. Pupae 48- 24 h before adult emergence of C. capitata males and both sexes of A. fraterculus were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Doses that induce 50, 90 and 99% of sterility were estimated and the hypothesis of Parallelism for the Probit equations was tested. Doses of 82.7 Gy of X-rays and 128.2 Gy of γ rays (thus, a RBE∼1.5) induced 99% sterility on medfly males. The fertility of A. fraterculus fertile females crossed with 41 Gy of X-rays and 62.7 Gy of γ rays decreased in 99% comparing with the control group (RBE∼1.5). 99% sterility of A. fraterculus irradiated females was achieved with 60-80 Gy (RBE∼0.7). The standard quality control parameters of fecundity, adult emergence, fliers and survival were not significantly affected by the two types of radiation (RBE∼1) either for medfly or A. fraterculus (p>0.01), being averages in conformity with the values required by FAO/IAEA/USDA. Only fecundity of irradiated A. fraterculus females was severely reduced with increasing doses and no egg was laid at 70 Gy of both radiations. There were no significant differences between X-rays and γ rays regarding mating indices (RSI for medfly, RII, ISI, MRPI and FRPI for A. fraterculus) (p>0.05), what indicated more random matings for fertile and sterile insects. The results demonstrated that no significant difference in biological

Studies on the ecology of insects sterilized artificially (gamma radiation), 7

International Nuclear Information System (INIS)

Kiyoku, Masao; Tsukuda, Ritsuko

1974-01-01

Larvae of an oriental fruit fly line introduced, from Amami-Oshima island were reared using an artificial medium prepared with the base ingredient as corn-flour. When pupae were irradiated with a dose of 8 kR from the 137 Cs as gamma-rays source two days before emerging, both male and female adults emerged showed complete sterility. Percentage in emergence, however, was not significantly reduced. In an experiment that two hundred sterilized plus ten normal males were confined with ten normal females in a mating cage, the sterilized males were fully competitive with normal ones in mating to the normal females. Longevity of the sterilized adult males, however, tended to be slightly shorter than that of the normal ones when compared in the survival curves. When less than one hundred and fifty sterilized males were confined, however, few larvae were able to grow to adults. These progeny adult males and females showed the inherited sterility. When dose was 6 kR there was neither significant difference in the longevity between sterilized and normal adults, nor the complete sterility. Besides, the inherited sterility in offspring was not shown clearly. When more than two hundred sterilized plus ten normal males were combined with ten normal females, however, a considerable sterility was found. Causes of the sterility were investigated by dissection of the testes and spermathecae in females mated with 8 kR-sterilized males. (author)

Present studies on the radio-sterilized drugs

International Nuclear Information System (INIS)

Marciniec, B.; Dettlaff, K.

2007-01-01

Lecture presents present status of radiosterilization of drugs and medical materials as compared to other sterilization methods. Literature review is shown on degradation of different kinds of drugs sterilized upon action of the sterilising doses of radiation

Crud removal with deep bed type condensate demineralizer in Tokai-2 BWR

International Nuclear Information System (INIS)

Abe, Ayumi; Takiguchi, Hideki; Numata, Kunio; Saito, Toshihiko

1996-01-01

The major objective and functions for the installation of the deep bed type condensate polishers in BWR power plants is to remove both ionic impurities caused by sea water leakage and suspended impurities called crud mainly consisting of metal oxides which are produced from metal corrosion. In considering the reduction of occupational radiation exposure level, it is extremely important to remove the crud effectively. In recent Japanese BWR power plants, condensate pre-filters with powdered ion exchange resins or with hollow fiber membrane have been installed to remove the crud at the upper stream of the deep bed polishers. In such plants, the crud removal is conventionally the secondary objective for the deep bed polishers. The Japan Atomic Power Company has introduced the small particle ion exchange resin and a soak regeneration method since April 1985, and then applied the low cross-linked resin since July 1995 at Tokai-2 Power Station, to improve the crud removal performance by using only deep bed type condensate demineralizer, and as a result condensate demineralizer outlet iron level has been kept below 1 ppb since 1991

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

International Nuclear Information System (INIS)

Kim, Jaehun; Choi, Jongil; Song, Beomseok

2010-09-01

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

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.

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.

A fiber-optic setup for quantification of root surface demineralization

NARCIS (Netherlands)

vanderVeen, MH; tenBosch, JJ

A fiber-optic fluorescence observation (FOFO) technique has been developed for the quantification of demineralized root dentin, The method was tested on 40 specimens of in vitro demineralized parts of human root dentin, Fluorescein sodium salt was used as a penetrating dye, The fluorescein sodium

Application of electron beam radiation for peat sterilization and suppression of microbe contaminants

International Nuclear Information System (INIS)

Tsai, David

2006-01-01

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 ( 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 (γ). The disadvantage of not reaching higher depth than gamma rays from 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 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 + (Study 1) and celB + (Study 2) from both eat-sterilizing techniques, reaching values above the minimum of 1x10 8 cells g -1 peat. At high rates, above 40 kGy, and after long

Radiation sterilization of harmful algae in water

International Nuclear Information System (INIS)

Byung Chull An; Jae-Sung Kim; Seung Sik Lee; Shyamkumar Barampuram; Eun Mi Lee; Byung Yeoup Chung

2007-01-01

Complete text of publication follows. Objective: Drinking water, water used in food production and for irrigation, water for fish farming, waste water, surface water, and recreational water have been recently recognized as a vector for the transmission of harmful micro-organisms. The human and animal harmful algae is a waterborne risk to public health and economy because the algae are ubiquitous and persistent in water and wastewater, not completely removed by physical-chemical treatment processes, and relatively resistant to chemical disinfection. Gamma and electron beam radiation technology is of growing in the water industry since it was demonstrated that gamma and electron beam radiation is very effective against harmful algae. Materials and Methods: Harmful algae (Scenedesmus quadricauda(Turpin) Brebisson 1835 (AG10003), Chlorella vulgaris Beijerinck 1896 (AG30007) and Chlamydomonas sp. (AG10061)) were distributed from Korean collection for type cultures (KCTC). Strains were cultured aerobically in Allen's medium at 25□ and 300 umol/m2s for 1 week using bioreactor. We investigated the disinfection efficiency of harmful algae irradiated with gamma (0.05 to 10 kGy for 30 min) and electron beam (1 to 19 kGy for 5 sec) rays. Results and Conclusion: We investigated the disinfection efficiency of harmful algae irradiated with gamma and electron beam rays of 50 to 19000 Gy. We established the optimum sterilization condition which use the gamma and electron beam radiation. Gamma ray disinfected harmful algae at 400 Gy for 30 min. Also, electron beam disinfected at 1000 Gy for 5 sec. This alternative disinfection practice had powerful disinfection efficiency. Hence, the multi-barrier approach for drinking water treatment in which a combination of various disinfectants and filtration technologies are applied for removal and inactivation of different microbial pathogens will guarantee a lower risk of microbial contamination.

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

International Nuclear Information System (INIS)

Jung, Inha

2013-12-01

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 st of June 2013 to 30 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

Influence of ionizing radiation on flight activity of F-1 progeny of sub-sterilized male moths of Spodoptera litura (fabr.) (lepidoptera: noctuidae)

International Nuclear Information System (INIS)

Zubeda; Zarin, Mahtab; Seth, R.K.; Seth, Ranjana

2012-01-01

Radiation mediated 'Inherited or F-1 sterility', as a parabiological (genetic) control measure using a range of 100-130 Gy to the male parents, has been proposed for the suppression of Spodoptera litura (Seth and Sehgal 1993; Seth and Sharma 2001). This is a modified Sterile Insect Technique (SIT) wherein sub-sterilizing gamma doses are preferred than the high (100%) sterilizing dose in order to sustain the insects competitiveness. In the present study the flight activity of F-1 progeny of sub-sterilized male moths was ascertained to judge the performance of F-1 sterility as a control tactic. The male flight ability of F-1 progeny males derived from sub-sterilized male moths, S. litura in presence of normal females, was tested in two modes in 'Flight assay chamber' (a perspex cage of size, 45 x 45 x 60 cm) having a black hollow cylinder (25.4 cm dia, 30.5 cm ht.) placed inside

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

Experimental studies on absorbed dose in radiation sterilization of pharmaceutical preparation

International Nuclear Information System (INIS)

Ohnishi, Tokuhiro; Okamoto, Shinichi; Kimura, Syojiro; Taimatsu, Meiko.

1991-01-01

For radiation sterilization, it is necessary to decide the irradiation conditions considering a balance between sterilization efficiency and chemical changes of samples by irradiation. These effects may be estimated by the product of two factors (D 10 and G value) and absorbed dose. In this work, it has been found experimentally by using Fricke dosimeter that the absorbed doses of the samples in vessels different in size, material, volume, etc. are not equal under the same gamma-ray irradiation condition. The correction factor from exposure to absorbed dose was estimated to be 6-7% for organic vessels (a polyethylene bag and a polystyrene vial) and a 20-ml glass vial, 9% for a 10-ml glass vial, and 10% for the 5-ml glass vial. These values of the correction factor were confirmed by using the changes of enzymic activity of saccharated powder pepsin preparation. In the cases of using organic vessels and the 10-ml glass vial, G-values for the change of the enzymic activity were calculated to show similar values in the range from 0.79 to 0.82. However, in the case of a small glass vial (5-ml), the value was 0.93. (author)

New ways of combating demineralization: link between classic and allopathic medicine

Science.gov (United States)

Idoraşi, Laura; Secoşan, Sandra Andreea; Ogodescu, Alexandru; Sinescu, Cosmin; Zaharia, Cristian; Stan, Adrian Tudor; Podoleanu, Adrian G.; Negruťiu, Meda-Lavinia

2018-03-01

Prevention and allopathic medicine gained attention, since it is possible for dentists to prevent demineralization, using plants and natural substances with well-known efficacy. The purpose of this study was to present new methods for teeth remineralization. It was made a selection of 10 extracted teeth, maintained in physiological serum, with no color fading, decay or demineralization. It was induced demineralization, with ortho-phosphoric acid (concentration 45 %), for one minute. The probes were visually and with optical coherence tomography (OCT) inspected. The natural product and the bonding with additional nanoparticles of argent were created and applied on the demineralization zone of the both groups of teeth. Each tooth in the first group had one plain surface demineralized. The second group of teeth had a cavity prepared on one of each tooth's side. The pastes were applied on the demineralized surfaces and in the demineralized cavities for two minutes. After time expired, the pasta applied on the first group of teeth was washed away; the bonding above the second group of teeth was light cured. The probes were again visually and with OCT inspected. It was observed an improvement in remineralizing the white marks on plain surfaces and in the created cavities, the OCT being able to detect different levels of remineralization. The efficacy of natural pasta depends on the time it is applied and the concentration of the different main substances. Also, the type of surface, plain or occlusal facets, may influence the substances' penetration ability. The non-invasive specific feature of these products, low costs and safety are strong positive aspects of this method of remineralization. However, the natural process of remineralization is a long-lasting one; perfecting the main substances in order to accelerate the process, in addition to several in vivo studies would be necessary to be fulfilled.

The development of radiation-induced sterility for the management of lepidopterous maize stem bores:El dana saccharina walker (pyraldae) and sesmia calamistis hampson (noctuidae)

International Nuclear Information System (INIS)

Annoh, C. E

2003-01-01

Radio-sterilization study was conducted on the biology of two lepidopterous maize stem borers, Eldana saccharina Walker and Sesamia calamistis Hampson to induce inherited sterility for insect pest management programme in Ghana. Bioecology of the two borer species was also studied for a 3-year period, 1997-1999 at Medie, a predominantly maize growing community in the Ga District of Greater Accra Region, to determine the population dynamics and climatic factors influencing the population of the borer species. It was observed that Sesamia species usually attacked the young maize crop, with peak infestations occurring about 6-S weeks after emergence of the crop. Eldana species preferred mature maize with peak infestations around 10-12 weeks after emergence of the maize crop. Larval numbers of E. saccharina showed inverse relations with rainfall, r= - 0.5899; p= 0.043. Infestation levels of larvae of both species were relatively higher during the minor rainy season than the major season. Larvae and pupae of E. saccharina that developed separately on natural and artificial diets did not show significant difference in most of their biological parameters. In both borer species, pupal weights of natural dieters were slightly heavier than those of artificial dieters. Exposure of young pupae (less than 6 days old) of the two borer species to increasing doses of ionizing radiation, SO-ISO Gy, resulted in high percentage of deformity and un emerged adults. Mature pupae of 6-S days old were less susceptible to increased doses and exhibited fewer body deformities and unemerged adults. The mating capability of adults emerged from irradiated mature pupae of E. saccharina was not adversely affected. In the parent generation (P), fecundity and fertility decreased with increased doses of radiation for crosses involving irradiated males and normal females as well as irradiated females and normal males. While the treatment m the former crosses resulted in partial fertility (40% at 180

Study on the biological activity of certain antihistamines subjected to radiation sterilization

International Nuclear Information System (INIS)

El-Sayed, M.E.; Roushdy, H.M.; Seham, H.H.M.

1986-01-01

The effect of gamma irradiation of pheniramine maleate and dimenhydrinate solution the dose levels 15, 25 and 50 KGY on their antihistaminic activity has been investigated using the histamine aerosol and guinea pig ileum methods. From the results obtained it could be concluded that, the antihistaminic activity of both pheniramine maleate and dimenhydrinate was not significantly changed by radiation exposure at the dose levels 15, 25 and 50 KGY. Accordingly, both of the two drugs can be safely sterilized by gamma-irradiation without encountering deleterious effect on their antihistaminic activity

Cryoradiation sterilization - contemporary state and outlook

International Nuclear Information System (INIS)

Talrose, V.L.

1995-01-01

The new approach of radiation sterilization -cryoradiosterilization with programmed freezing - was developed for pharmaceutical solutions. Both scientific and technical problems are solved, the results are discussed. Programmed freezing of vials with the drug's solutions provides the high stability of soluted components with biological activity at sterilizing irradiation without significant change of sterilization doses. Physical, chemical, biological and pharmacological properties of a lot of drug solutions for injection satisfy official requirements after cryoradiation sterilization treatment. This method seems to be especially important for the protein systems which could be infected by dangerous viruses (VIH, hepatitis B): blood plasma, diagnostic sera, protein preparations manufactured from donor's blood, etc. (Author)

Safety and clinical efficacy of some radiation-sterilized medical products and pharmaceuticals

International Nuclear Information System (INIS)

Kulkarni, R.D.; Gopal, N.G.S.

1975-01-01

Medical products and pharmaceuticals must conform to certain minimum physico-chemical microbiological and biological requirements. The biological requirements comprise principally testing for toxicity, safety, and pyrogens. Besides the above-mentioned criteria, there are two other important characteristics, viz. clinical efficacy and tolerance in animal and/or human beings. These latter requirements, expected from the final product released for general human use, are not carried out routinely. In the present-day pharmaceutical and medical technology, numerous mew products are appearing, many of them requiring radiation sterilization as they are not stable towards the other conventional methods of sterilization. While the post-irradiation physicochemical changes in a product may not be significant, the bio-availability or biological activity of the product may be affected to a more significant extent. Some evidence of this has recently been reported. Hence, it is desirable to carry out studies on safety as well as clinical efficacy on irradiated products. This paper describes some studies on plastic-based medical products, a pharmaceutical raw material, a typical infusion fluid such as normal saline, antibiotics and their ointments. (author)

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.

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.

Gamma-irradiation sterilization of lipases for cheese making

Energy Technology Data Exchange (ETDEWEB)

Umanskij, M S; Borovkova, Yu A; Odegov, N I [Vsesoyuznyj Nauchno-Issledovatel' skij Inst. Maslodel' noj i Syrodel' noj Promyshlennosti, Uglich (USSR)

1979-03-01

The possibility of sterilizing the enzyme compounds of lipases from Oospora fragrans strains by gamma irradiation was studied. The enzyme compounds were exposed to gamma irradiation at the doses from 0.1 to 0.8 Mrad with the discreteness of 0.1 Mrad and at the dose of 2.0 Mrad. After the radiation treatment the lipases were investigated for bacterial invasion by the cultivation method and for the lipolytic activity by the titrometrical method. It is shown that the sterilization effect is achieved without losses of lipase activity and the radiation dose necessary for sterilization depends on initial invasion levels in the enzyme compounds.

Cosmology seeking friendship with sterile neutrinos

International Nuclear Information System (INIS)

Hamann, J.; Hannestad, S.; Raffelt, G.G.; Tamborra, I.; Wong, Y.Y.Y.

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.

Radiation Induced F-1 Sterility For The Control Of Cotton Bollworm , Helicoverpa armigera (Huebner) In Pilot Test

International Nuclear Information System (INIS)

Segsarnviriya, Suchada; Pransopon, Prapon; Kongratarpon, Titima; Vongcheeree, Satit

2005-10-01

Pilot trials of radiation induced F-1 sterility for the control of cotton bollworm Helicoverpa armigera (Hubner) were studied for 3 cotton crop seasons in 3 locations at Amphor Takfa, Nakornsawan province in 2002, 2003 and 2004. Irradiated male pupae at a sub sterilizing dose of 150 Gy were released : approximately 11,170 42,900 and 36,400 pupae from July to December of 2002, 2003 and 2004, respectively. The insecticide plots were maintained as a comparison to determine the efficiency of this method. Checking of larvae on cotton plants by the systematic random sampling method and the cotton yield were used to evaluate the impact of the pupal release. It was found that the releasing plots and the insecticide plots gave similar results in terms of the number of larvae and the cotton yield. Therefore, the F-1 sterility method was a possible method for the control of cotton bollworm

Choice of the irradiation dose for the sterilization of medical products

International Nuclear Information System (INIS)

Bochkarev, V.V.; Pavlov, E.P.; Sedov, V.V.; Khrushchev, V.G.; Tushov, Eh.G.; Konyaev, G.A.

1975-01-01

The principles for selecting the appropriate dose for the radiation sterilization of medical products are set forth, taking into account the initial contamination of the product, the radiation senstivity of contaminants and the required level of reliability of sterilization. The initial contamination level of certain preparations (glucose and radiopharmaceuticals) is established and the radiation sensitivity of the isolated contaminants is determined in terms of Dio indices. Of the microorganisms isolated the most common were staphylococci, streptococci, Gram-negative bacteria, Aspergilli, Penicillia and yeast fungi. Spore-forming types of microorganisms were isolated with a frequency of the order of 10 -2 . The radiation sensitivity in terms of D 10 was established for more than 3000 strains of microorganisms. For 75-85% of the strains the D 10 indices gave 10-40 krad and for 0.2-1% more than 100 krad. The experimental data were subjected to computer analysis which confirmed the adequacy of the techniques used to determine radiosensitivity. The authors then calculated by computer the radiation sterilizing doses for different degrees of initial contamination of the products with reliability coefficients of 10 6 and 10 8 . For sterilizing radiopharmaceuticals and glucose solutions these doses are 0.8-1 Mrad. Verification experiments show that these doses give reliable sterilization of the medical products concerned. (author)

Radiation induced F1 sterility in diamondback moth, Plutella xylostella L., and tropical army worm, Spodoptera litura F

International Nuclear Information System (INIS)

Sutrisno, S.; Hoedaya, M.S.; Sutardji, D.; Rahayu, A.

1993-01-01

A 300 Gy dose of gamma irradiation can be used as the sterilizing dose for the diamond-back moth (DBM). This caused 90% sterility of the moths. Releases of irradiated moths into the normal populations (nine irradiated to one normal) in laboratory cages, field cages and small field plots reduced the F 1 population by 61, 55 and 42%, respectively. The effects of substerilizing doses of 175 and 200 Gy to the irradiated parents caused 26 and 36% sterilities, respectively. The dose of 175 Gy caused the levels of sterility of the male and female F 1 progeny to be 54 and 74%, respectively, while the dose of 200 Gy caused 56% sterility of the F 1 male and 71% of the F 1 female. The sterility of the F 2 population was nearly the same as that of the irradiated parents. At a radiation doses of 175 Gy the sterility of F 2 males was about 11% and of females 37%. At a dose of 200 Gy the levels of sterility of the males and females were 9 and 14%, respectively. Gamma irradiation did not affect the fecundity of the irradiated parents or of the F 1 and F 2 progeny. The average number of eggs produced by one pair of DBM moths was 180. The viabilities of unirradiated pupae, irradiated parents, F 1 and F 2 at a dose of 200 Gy were 94, 89, 54 and 65%, respectively. The effect of releasing F 1 sterile moths into untreated populations at a ratio of 45:1 could be a reduction in the population by 22%. Delta traps baited with the sex pheromone Sj showed the highest trapping efficiency. The highest population of DBMs in the dry season is in May and the lowest point is in July. The longevity of the tropical army worm was slightly affected by gamma irradiation. The dose of irradiation did not affect the viability of the pupae. A substerilizing dose of 100 Gy caused 43% parental sterility, 76% F 1 sterility and 54% F 2 sterility. (author). 7 refs, 3 figs, 8 tabs

Design of the Demineralized Water Make-up Line to Maintain the Normal Pool Water Level of the Reactor Pool in the Research Reactor

International Nuclear Information System (INIS)

Yoon, Hyun Gi; Choi, Jung Woon; Yoon, Ju Hyeon; Chi, Dae Young

2012-01-01

In many research reactors, hot water layer system (HWLS) is used to minimize the pool top radiation level. Reactor pool divided into the hot water layer at the upper part of pool and the cold part below the hot water layer with lower temperature during normal operation. Water mixing between these layers is minimized because the hot water layer is formed above cold water. Therefore the hot water layer suppresses floatation of cold water and reduces the pool top radiation level. Pool water is evaporated form the surface to the building hall because of high temperature of the hot water layer; consequently the pool level is continuously fallen. Therefore, make-up water is necessary to maintain the normal pool level. There are two way to supply demineralized water to the pool, continuous and intermittent methods. In this system design, the continuous water make-up method is adopted to minimize the disturbance of the reactor pool flow. Also, demineralized water make-up is connected to the suction line of the hot water layer system to raise the temperature of make-up water. In conclusion, make-up demineralized water with high temperature is continuously supplied to the hot water layer in the pool

Pre-sterilization contamination of disposable medical products and the choice of minimum sterilization dose

International Nuclear Information System (INIS)

Horakova, V.; Buriankova, E.

1975-01-01

The bacterial contamination was assessed on randomly taken samples of blood-transfusion devices, donor sets, intra-uterine contraceptive devices and inserters, surgical gloves and dressing material prior to sterilization. The quantitative and qualitative efficiency of six nutrient media was compared. The best results were obtained with the enriched ''Universal'' medium. It was confirmed that the contamination of plastic products was low compared with dressing material. Most frequently, Gram-positive aerobic spore-forming rods and Gram-positive cocci were found on non-sterile medical disposable products. A method was tested to obtain a general informative picture of the resistance of bacteria on products. The methods used for choosing the dose for radiation sterilization of medical products are discussed. (author)

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...... and documented uncertainty limits of the dose measurements can be used to specify process control limits. This is also useful, for example, when dose setting experiments are carried out according to the methods described in ISO 11137, where product samples shall be irradiated within narrow limits......., 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...

Determination of the dose of gamma radiation sterilization for assessment of biological parameters of male Ceratitis capitada (Diptera: Tephritidae), tsl - Vienna 8 strain

International Nuclear Information System (INIS)

Rocha, Aline Cristina Pereira da

2011-01-01

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 - 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 of

Bacteriological examination and biological characteristics of deep frozen bone preserved by gamma sterilization

International Nuclear Information System (INIS)

Pham Quang Ngoc; Le The Trung; Vo Van Thuan; Ho Minh Duc

1999-01-01

To promote the surgical success in Vietnam, we should supply bone allografts of different sizes. For this reason we have developed a standard procedure in procurement, deep freezing, packaging and radiation sterilization of massive bone. The achievement in this attempt will be briefly reported. The dose of 10-15 kGy is proved to be suitable for radiation sterilization of massive bone allografts being treated in clean condition and preserved in deep frozen. Neither deep freezing nor radiation sterilization cause any significant loss of biochemical stability of massive bone allografts especially when deep freezing combines with radiation. There were neither cross infection nor change of biological characteristics found after 6 months of storage since radiation treatment. In addition to results of the previous research and development of tissue grafts for medical care, the deep freezing radiation sterilization has been established for preservation of massive bone that is of high demand for surgery in Vietnam

Kinetic modelling of the demineralization of shrimp exoskeleton using citric acid

Directory of Open Access Journals (Sweden)

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.

'Adult T-cell leukemia/lymphoma' with bone demineralization

International Nuclear Information System (INIS)

Ohuchida, Toshiyuki; Nishitani, Hiromu; Matsuura, Keiichi

1985-01-01

Two patients with T-cell malignancy having radiographic manifestations of generalized and localized bone demineralization are reported. One, a 53-year-old-man, had marked osteoporosis and severe hypercalcemia, but no clinical evidence of leukemia throughout his illness. At autopsy there was no definite evidence of bone involvement. Histologic proof was obtained from abdominal skin which revealed ''adult T-cell leukemia/lymphoma (ATLL).'' The second case, a 33-year-old man, complained of arthralgia in his hands and feet; radiographs showed severe localized demineralization and pathologic fractures. Specimens of his peripheral blood, cervical lymph nodes, and bone marrow revealed ATLL cells. (orig.)

Sterilization of spices through ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Heins, H G; Ulmann, R M

1971-10-01

Sterilization of spices is discussed in relation to other methods. Efficiency, organoleptic inspection and costs of the treatment are considered. It is concluded that the irradiation method is feasible and acceptable with respect to taste and juridicial requirements. (G.J.P.). 12 refs.; 1 figure; 4 tabs.

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

DEFF Research Database (Denmark)

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

1992-01-01

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

Research within the coordinated programme on practices for the radiation sterilization of medical supplies in countries of Asia and the Pacific Region

International Nuclear Information System (INIS)

Hilmy, N.

1982-01-01

The results are presented of a four year coordinated research programme related to: effects of gamma radiation on chloramphenicol and hydrocortisone acetate mixture eye ointment, methodology of biological dosimetry, radiation sterilization dose setting using fraction positive and most resistant microbes, effects of gamma radiation on neomycin sulphate and procaine penicillin G in solid state, and calibration of panoramic batch irradiation using Ceric dosemeter

Management of unicameral bone cyst by using freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow.

Science.gov (United States)

Datta, N K; Das, K P; Alam, M S; Kaiser, M S

2014-07-01

Unicameral bone cyst is a common benign bone tumor and most frequent cause of the pathological fracture in children. We have started a prospective study for that treatment of unicameral bone cyst by using freeze dried radiation sterilized bone allograft impregnated with autogenous bone marrow in the department of Orthopaedics, Bangabandhu Sheikh Mujib Medical University (BSMMU) during May 1999 to April 2012. Aim of this study was to see Freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow a satisfactory graft material in the treatment of unicameral bone cyst as well as factors such as patients age, sex, cyst size and site of lesion influence on cyst healing. A total 35 patients of unicameral bone cyst were operated. In this study out of 35 patients, male were 22(62.86%) and female were 13(37.14). Male Female ratio 22:13(1.70:1) Age of the patients ranging from 2 years 6 month to 20 years, mean age 12.18 years more common 11 years to 20 years 29(82.86%) patients. Common bones sites involvements are proximal end of Humerus 20(57.14%), proximal end of Femur 7(20 %), proximal end of Tibia 3(8.57%), Calcanium 2(5.71%), proximal end of Ulna 1(2.86%), shaft of Radius 1(2.86%) and Phalanx 1(2.86%). Final clinical outcome of unicameral bone cyst treated by thorough curettage of cavity and tightly filled with freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow in which healed (success rate) 88.57% (31) and recurrence rate is 11.43% (4). P value is unicameral bone cyst.

Microbiological method for radiation sterilization (I). General knowledge and handling technique for bacterial identification

International Nuclear Information System (INIS)

Koshikawa, Tomihiko

2004-01-01

The part I in this title series describes the basic knowledge and technique for identification of bacteria in the radiation sterilization of medical devices, where the radiation dose can be decided from the number and radio-resistance of the bioburden (bacteria on the device). Four essential, actual technologies for identification are described: isolation and storage of bacteria; decision of bacterial natures, involving 3 Gram staining methods, morphology by microscopy and/or phase-contrast microscopy, spore-forming bacteria, and size measurement by micrometry; Other test items for identification of genus, involving motility, oxygen demand, catalase, oxidase, acid production from glucose, and OF (oxidation or fermentation for glucose degradation) test; and colony observation. Media, identification kits and record forms for these are presented. (N.I.)

Extraskeletal and intraskeletal new bone formation induced by demineralized bone matrix combined with bone marrow cells

International Nuclear Information System (INIS)

Lindholm, T.S.; Nilsson, O.S.; Lindholm, T.C.

1982-01-01

Dilutions of fresh autogenous bone marrow cells in combination with allogeneic demineralized cortical bone matrix were tested extraskeletally in rats using roentgenographic, histologic, and 45 Ca techniques. Suspensions of bone marrow cells (especially diluted 1:2 with culture media) combined with demineralized cortical bone seemed to induce significantly more new bone than did demineralized bone, bone marrow, or composite grafts with whole bone marrow, respectively. In a short-term spinal fusion experiment, demineralized cortical bone combined with fresh bone marrow produced new bone and bridged the interspace between the spinous processes faster than other transplantation procedures. The induction of undifferentiated host cells by demineralized bone matrix is further complemented by addition of autogenous, especially slightly diluted, bone marrow cells

Use of gamma radiation of Cobalt-60 aiming at the quarentenary treatment and the sterilization of Stenoma catenifer Walsingham (Lepidoptera: Elachistidae)

International Nuclear Information System (INIS)

Silva, L.K.F.; Arthur, V.; Nava, D.E.; Parra, J.R.P.

2007-01-01

The objective of this work was verify the influence of gamma radiation of Cobalt-60, in the avocado moth Stenoma catenifer Walsingham (Lepidoptera: Elachistidae). For this research, insects were irradiated in all phases of their life cycle with doses varying from 0 to 600 Gy and they were maintained at the temperature of 25 +/- 2 deg C, relative humidity of 70 +/- 10% and photofase of 14 h. The species was reared on natural diet, avocado seeds, variety Breda. According to the obtained results, was verified that the lethal dose of gamma radiation to S. catenifer larvae and pupae was of 300 Gy. The sterile dose for upcoming adults from irradiated S. catenifer larvae, was of 100 Gy; for adults coming from irradiated pupas was of 150 Gy and for irradiated adults was of 200 Gy. The use the gamma radiation as treatment quarentine of S. catenifer was efficient, should be treated them with doses able to promote the sterilization of insect, without committing your qualities physical-chemistries and sensorial of fruits. Therefore, is suggested the treatment with the dose of 50 Gy for fruits infested with eggs and 150 Gy for fruits infested with larvae and pupas of S. catenifer. For use the sterile insect technique is recommended the irradiation of pupas and adults with doses of 150 Gy and 200 Gy, respectively [pt

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.

Sterilization studies on the adult indian meal moth, plodia interpunctella (HUBNER)

International Nuclear Information System (INIS)

Boshra, S.A.; Hasaballa, Z.A.

1993-01-01

The effects of gamma radiation doses ranging between 10 and 65 krad on adult plodia interpunctella (Hubner) were studied. Irradiation of adult affected clearly the egg production and fertility of both sexes at different mating combinations. Females were more sensitive to the sterilizing effects of gamma radiation than males. Complete sterility of females and males was achieved at 50 and 65 krad, respectively. Replacing normal males by sterile ones in the normal population decreased the egg hatch ability when compared with the control population. Newly emerged unmated females laid completely infertile eggs when confined with irradiated (65 krad) males, whether mating occurred on the day of treatment or 2 days after treatment. Sterilized males were able to compete with normal ones in a population at the highest flooding ratios. Adding sterile females to this competing population gave excellent results.5 tab

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

1996-12-31

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.

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.

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.

Sterile diets for the immuno-comprised: is there a need?

International Nuclear Information System (INIS)

Butterweck, J.S.

1995-01-01

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 also ''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. (Author)

Anisotropy in Bone Demineralization Revealed by Polarized Far-IR Spectroscopy

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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.

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.

Studies on the ecology of insects sterilized artificially (gamma radiation), 8

International Nuclear Information System (INIS)

Kiyoku, Masao; Tsukuda, Ritsuko

1974-01-01

Gamma-ray irradiation of 7 KR from 137 Cs on the oriental fruit fly pupae two days before emerging did not significantly reduce the percentage of emergence and longevity of adult flies. However, highly sterile adults (more than 98.9%) were found in those combinations, S#male# x N#female#, N#male# x S#female# and S#male# x S#female#. The result of observation of sperm activity in spermathecae of females mated with sterilized males showed that the sterility is caused by dominant lethalities. The sexual competitiveness between S#male# and N#male# has been examined in experiments of S#male# x N#male# x N#female#. (1) The data suggest that the sterility percentage concerning with egg hatchability is proportional to the rate of sterilized males replaced for normal males when that is expressed with a multiple of the ratio of normal males to normal females. Seven such straight lines thus obtained made us possible to find the theoretical expectation of sterility percentage. (2) Relationship between the percent egg hatch observed (y), or that estimated theoretically (Y), and logarithm of ratio, S#male#/N#male# (x) was showed to be two straight regression equations, y=18.413-11.952 (x - 1.295) and Y=11.890-15.462 (x - 1.295). Ratio of regression coefficients of the equations was 0.772. (3) Correlations between the sterility percentage and ratio, S#male#/N#male#, showed in three convex curves under three degrees of competitiveness (0.265, 0.576 and 1.001). When both the values of S#male#/N#male# in the mating experiments and the sterility percentages are given, it is possible to obtain degrees of competitiveness using the curves. (auth.)

Analysis of Ion-Exchange Resin Capability of the RSG-GAS Demineralized Water System (GCA01)

International Nuclear Information System (INIS)

Diyah Erlina Lestari; Setyo Budi Utomo; Harsono

2012-01-01

The Demineralized water system (GCA01) is a system which is function to process raw water to be demineralized water using ion exchange resin unit consisting of a column of cation exchange resins, anion exchange resin column and the column resin mix bed. After certain time the ion exchange resins to be saturated so that is needed regeneration. The RSG-GAS demineralized water system (GCA01) not operated continuously and indication of when does an ion exchange resin regeneration on The RSG-GAS demineralized water system (GCA01) is the water conductivity from anion exchange resin column output indicates ≥ 5μS/cm. Analysis of capability of the ion exchange resin demineralized water system (GCA01) line I has been performed. The analysis was done by comparing the time required in the system operating cycle of regeneration to the next regeneration during the period 2011 and 2012. From the results of the analysis showed the cycle regeneration time is varies. This shows that ion exchange resin capability of the RSG-GAS demineralized water system (GCA01) is varies depending on the raw water quality and success of the regeneration ion exchange resin. (author)

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.

Sterilization validation for medical compresses at IRASM multipurpose irradiation facility

International Nuclear Information System (INIS)

Alexandru, Mioara; Ene, Mihaela

2007-01-01

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

Design, Construction and Evaluation of a Dry Solar Sterilizer

International Nuclear Information System (INIS)

Hernández Fereira, Arcelio A.

2017-01-01

The objective of the work was the search of an alternative for sterilization using solar energy. For such purposes, a dry solar sterilizer of 4276 cm3 capacity was designed, constructed and evaluated. Potential users would be rural medical posts in areas without electricity, health posts in military units under field conditions, and experimental microbiology stations. The evaluation included the determination of the energy efficiency of the sterilizer, the economic evaluation against other variants and the biological safety assessment. The developed equipment reached the sterilization temperature for levels of the direct component of the solar radiation higher than 300 W/m2 in 14 minutes, corresponding to an average heating rate of 13 0C/minute, higher than that of an electric furnace. Its energy efficiency with direct solar radiation of 310.5 W/m2 was 53.79%. The equipment is of easy construction, simple operation and very low cost. (author)

Solubility effects in waste-glass/demineralized-water systems

International Nuclear Information System (INIS)

Fullam, H.T.

1981-06-01

Aqueous systems involving demineralized water and four glass compositions (including standins for actinides and fission products) at temperatures of up to 150 0 C were studied. Two methods were used to measure the solubility of glass components in demineralized water. One method involved approaching equilibrium from subsaturation, while the second method involved approaching equilibrium from supersaturation. The aqueous solutions were analyzed by induction-coupled plasma spectrometry (ICP). Uranium was determined using a Scintrex U-A3 uranium analyzer and zinc and cesium were determined by atomic absorption. The system that results when a waste glass is contacted with demineralized water is a complex one. The two methods used to determine the solubility limits gave very different results, with the supersaturation method yielding much higher solution concentrations than the subsaturation method for most of the elements present in the waste glasses. The results show that it is impossible to assign solubility limits to the various glass components without thoroughly describing the glass-water systems. This includes not only defining the glass type and solution temperature, but also the glass surface area-to-water volume ratio (S/V) of the system and the complete thermal history of the system. 21 figures, 22 tables

Radiation induced F1 sterility in Helicoverpa zea (Boddie): Potential for area-wide control

International Nuclear Information System (INIS)

Carpenter, J.E.

1993-01-01

The potential of using F 1 sterility as a management strategy for the corn earworm (CEW), Helicoverpa zea (Boddie), has been revealed through laboratory and field investigations. A 100 Gy dose of radiation induced deleterious effects in CEWs' which were inherited through several generations. Irradiated, laboratory reared CEWs were competitive with non-irradiated, laboratory reared CEWs in attracting and securing mates under field conditions. Females that mated to non-irradiated males and males irradiated with 100 Gy had the same mating propensity and the same intermating interval. Although there was a difference in mortality between larvae from irradiated and non-irradiated parents when reared in the laboratory, this mortality differential was reduced when larvae were reared under natural conditions in the field. Other studies revealed that there was no interaction between inherited sterility and diapause in CEWs when depth of pupation, initiation and termination of diapause, egg hatch, fecundity or survival were investigated. A pilot test that investigated the efficacy of using inherited sterility for suppressing seasonal population increases of CEWs was conducted from 1988 to 1990. Results of the pilot test revealed that irradiated (100 Gy) males released in mountain valleys were competitive with wild males in infusing their genes into the wild population. Analysis of seasonal population curves of wild CEW males calculated from mark-recapture data suggested that seasonal increases in wild CEW males were delayed or reduced in valleys where irradiated males were released. (author). 19 refs, 3 figs

[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.

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.

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.

Radiation Sterilization of Naturual Rubber Examination Gloves

International Nuclear Information System (INIS)

Jetawattana, S.; Na-Ranong, N.; Kajornchaiyakul, V.

1998-01-01

The sterilization dose setting by ISO 11137 method 1 was conducted for natural rubber examination gloves provided by a local factory. The suitable sterilization dose for an average product bioburden falls between 20 - 25 kilogray. Maximum dose of 25 or 50 kilogray results in no changes of tensile s and elongation at break. Samples of examination glove were irradiated using various doses between 10 - 50 kilogray. Analysis of soluble protein content using modified Lowry method was carried out and the results revealed that irradiation did not affect the decrement of soluble protein content in this case. However, thin film samples were prepared in laboratory and treated in the same procedure. The results were also the same. The results did not show any correlation. Two factors are possibly presumed : un consistency of samples and the irradiation of finished products could not affect those soluble proteins in rubber gloves

Tumor sterilization dose and radiation induced change of the brain tissue in radiotherapy of brain tumors

International Nuclear Information System (INIS)

Yoshii, Yoshihiko; Maki, Yutaka; Takano, Shingo

1987-01-01

Ninety-seven patients with brain tumors (38 gliomas, 26 brain metastases, 18 sellar tumors, 15 others) were treated by cobalt gamma ray or proton radiotherapy. In this study, normal brain injury due to radiation was analysed in terms of time-dose-fractionation (TDF), nominal standard dose (NSD) by the Ellis formula and NeuNSD by a modification in which the N exponent was -0.44 and the T exponent was -0.06. Their calculated doses were analysed in relationship to the normal brain radiation induced change (RIC) and the tumor sterilization dose. All brain tumors with an exception of many patients with brain metastases were received a surgical extirpation subtotally or partially prior to radiotherapy. And all patients with glioma and brain metastasis received also immuno-chemotherapy in the usual manner during radiotherapy. The calculated dose expressed by NeuNSD and TDF showed a significant relationship between a therapeutic dose and a postradiation time in terms of the appearance of RIC. It was suggested that RIC was caused by a dose over 800 in NeuNSD and a dose over 70 in TDF. Furthermore, it was suggested that an aged patient and a patient who had the vulnerable brain tissue to radiation exposure in the irradiated field had the high risk of RIC. On the other hand, our results suggested that the tumor sterilization dose should be over 1,536 NeuNSD and the irradiated method should be further considered in addition to the radiobiological concepts for various brain tumors. (author)

Sterilizing effects and lethal effects of gamma radiation on different phases of life cycle of the sitotroga cerealella (Olivier) in rice and maize

International Nuclear Information System (INIS)

Arthur, V.

1985-01-01

The objective of this research to verify the effects of the gamma radiation on different phases of the life cycle of the gamma radiation on different phases of the life cycle of the moth grain Angoumois, Sitotroga cerealella (Olivier, 1819). For all the treatment with gamma radiation a Cobalt-60 source type Gammabeam-650 was used and the activity was approximately 3.1 x 10 sup(14) Bq., with dose rate of 3.01 kGy per hour. The LD sub(100) of gamma radiation for eggs of insects reared in rice and maize were respectively 100 Gy and 125 Gy. The sterilizing doses in adults which were irradiated at immature phases (larvae and pupae) were 100 Gy and 200 Gy in rice and 150 Gy and 250 Gy in maize, respectively. The sterilizing doses for females and males in maize were respectively 350 Gy and 500 Gy. The LD sub(100) for adult females were 4500 Gy and 4750 Gy for males, both in rice. The LD sub(100), for adult reared on maize was 4750 Gy for both sexes. (author)

Comparison of ossification of demineralized bone, hydroxyapatite, Gelfoam, and bone wax in cranial defect repair.

Science.gov (United States)

Papay, F A; Morales, L; Ahmed, O F; Neth, D; Reger, S; Zins, J

1996-09-01

Demineralized bone allografts in the repair of calvarial defects are compared with other common bone fillers. This study uses a video-digitizing radiographic analysis of calvarial defect ossification to determine calcification of bone defects and its relation to postoperative clinical examination and regional controls. The postoperative clinical results at 3 months demonstrated that bony healing was greatest in bur holes filled with demineralized bone and hydroxyapatite. Radiographic analysis demonstrated calcification of demineralized bone-filled defects compared to bone wax- and Gelfoam-filled regions. Hydroxyapatite granules are radiographically dense, thus not allowing accurate measurement of true bone healing. The results suggest that demineralized bone and hydroxyapatite provide better structural support via bone healing to defined calvarial defects than do Gelfoam and bone wax.

Attempt to establish the ionizing radiation dose to be used in the sterilization of one-use medical equipment units

International Nuclear Information System (INIS)

Czerniawski, E.; Stolarczyk, L.

1974-01-01

The radioresistance of 8576 microbiological clones was examined. 8314 bacterial clones were isolated in the injection needle factory halls, from the surface exposed to strong ionizing irradiation sources. Those 649 clones which proved resistant to 2-4 Mrad radiation doses were used in further research work. The sterilizing value was based upon a detailed analysis of the bacteria according to their radioresistance groups and D 10 values. The 3 Mrad doses have to be used in order to achieve the sterility degree of a 10 6 product series with an initial 100-microorganisms infection. In case of a 1000/one product bacteria infection limit, the dose should be raised to 3.5 Mrad. (author)

Efficacy of various topical agents to prevent enamel demineralization

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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

Study of fieldbus technology applied in a sterilization plant control and safety systems

International Nuclear Information System (INIS)

Karam Junior, Dib

2000-01-01

Several sterilization processes have been used in these years for treatment of countless products. Some processes use high temperatures, thermal shocks and chemical agents. With the discovery of the ionizing radiation and its posterior technological developments turned possible application of that process, in 1960, also in the the sterilization, denominated radiation sterilization. This process became also applied in another areas of health and industrial as food conservation, gemstones enhancement and others. The radiation sterilization requests an effective control and it needs a high level of safety. The commercial use of the computers applied in industrial automation provides and the domain of new technologies in this field provides new applications then new designs now is possible. The Fieldbus technology, a new digital communication protocol, like a Local Area Network, can be an alternative in the cobalt-60 irradiation plant. The present work suggests, evaluates, qualifies and quantifies this possibility. (author)

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

International Nuclear Information System (INIS)

Savaris, M.; Santos, V. dos; Brandalise, R.N.

2016-01-01

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 (SH 2 O 2 ), saturated steam (SSS), electron beam radiation (SEB) and gamma radiation (SGR). The samples of PLA SEtO , PLA SH2O2 , PLA SEB and PLA SGR exhibited thermal and physical changes after being submitted to sterilization processes. PLA SSS showed morphological, chemical, thermal and physical changes. It is concluded that processes by SEtO, SH 2 O 2 , 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. - Highlights: • PLA was subjected to five different sterilization process. • All sterilization processes do not changed the hydrophilicity of PLA. • Morphological, chemical, physical and thermal changes were observed for the PLA SSS . • The sterilization by saturated steam is not recommended to sterilize PLA.

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...

Guide for dosimetry for sterile insect release programs. 2. ed.

International Nuclear Information System (INIS)

2004-01-01

This guide outlines dosimetric procedures to be followed for the radiation sterilization of live insects for use in pest management programs. The primary use of irradiated, reproductively sterile insects is in the Sterile Insect Technique, where large numbers of sterile insects are released into the field to mate with and thus control pest populations of the same species. A secondary use of sterile insects is as benign hosts for rearing insect parasitoids. The procedures outlined in this guide will help ensure that insects processed with ionizing radiation from gamma, electron, or X-ray sources receive absorbed doses within a predetermined range. Information on effective dose ranges for specific applications of insect sterilization, or on methodology for determining effective dose ranges, is not within the scope of this guide. Note: Dosimetry is only one component of a total quality control program to ensure that irradiated insects are adequately sterilized and sufficiently competitive or otherwise suitable for their intended purpose. This guide covers dosimetry in the irradiation of insects for these types of irradiators: self-contained dry-storage 137 Cs or 60 Co irradiators, large-scale gamma irradiators, and electron accelerators. Additional, detailed information on dosimetric procedures to be followed in installation qualification, operational qualification, performance qualification, and routine product processing can be found in ISO/ASTM Practices 51608 (X-ray [bremsstrahlung] facilities), 51649 (electron beam facilities), 51702 (large-scale gamma facilities), and ASTM Practice E 2116 (self-contained dry-storage gamma facilities). The absorbed dose for insect sterilization is typically within the range of 20 Gy to 600 Gy

Effects of sterilizing radiation dose on the amino acid composition of normal human Ig(G)

International Nuclear Information System (INIS)

Kaupert, N.L.; Mariano, E.E.

1981-01-01

In order to verify gamma radiation effect of 60 Co, samples of Normal human Ig(G) in a) pH 7 solutions with different concentrations, and b) in liophilized state, were irradiated. In both, the quali and quantitative amino acid compositions have been studied. No changes in amino acid composition were observed, for doses up to 10 Mrad delivered to the liophilized samples. Nevertheless, when 5 mg/ml and 10 mg/ml solutions of Ig(G) were irradiated with a 2 Mrad gamma dose, both were affected. The damage appeared in greater proportion in the samples with lower concentration. Cistine was the amino acid most damaged and the loss of methionine, proline histidine, arginine, tirosine and phenilalanine, decreased in this order. The analysis of the experimental data shows that liophilized human Ig(G) can be treated with doses higher than those required to achieve sterilization, without modifying its immunologic and primary proteic structure properties. Therefore, gamma sterilization feasibility has been proved for normal human Ig(G) only in the liophilized state. (author) [es

Gamma radiation effects on mating behavior, inherited sterility, and competitiveness of Cadra cautella (Walker) (Lepidoptera:Pyralidae)

International Nuclear Information System (INIS)

Amoako-Atta, B.

1976-01-01

Mating efficiency of male Cadra cautella is restricted to within 72 hr of pose-eclosion. Gamma radiation of 8-day pupae did not affect the mating frequency of males in constant association with females for 72 hrs. When association was delayed for 1--7 days, there was progressive decrease in mating efficiency. The decline was related to reduced sperm viability. Increasing the dose accentuated the reduction in reproductive potential. Reproductive behavior of generation lines (F 1 --F 5 ) between irradiated males and normal females was studied. The sex ratio was distorted (more males) primarily in the F 1 and F 2 generations; the reproductive rate was lower in these early generations. When reproductive rate increased, the sex ratio was not distorted. A partially sterilizing dose of 20 krad to P 1 males induced complete inherited sterility in the progeny; the population of F 1 --F 2 collapsed. The ratio of sterile to fertile males needed to reduce reproductive nonirradiated females to 0 in the laboratory was studied. Release ratios of sterile males (S) : normal males (M) : fertile virgin females (N) varied from 0--20 S:M:N respectively. Population increases from various release ratios were lowered in each successive release ratio. The 20 S reduced the mean population increase of 2N from the expected 300-fold (as in the controls 0S:2M:2N) to only 4-fold. In that 20S:2M:2N release ratio, only 15% of the cultures produced any measurable F 1 progeny (average = 4F 1 progeny/culture) whereas the remaining 85% of the cultures did not produce any F 1 progeny. All control cultures were productive

Ultrasonically-induced electrical potentials in demineralized bovine cortical bone

Science.gov (United States)

Mori, Shunki; Makino, Taiki; Koyama, Daisuke; Takayanagi, Shinji; Yanagitani, Takahiko; Matsukawa, Mami

2018-04-01

While the low-intensity pulsed ultrasound technique has proved useful for healing of bone fractures, the ultrasound healing mechanism is not yet understood. To understand the initial physical effects of the ultrasound irradiation process on bone, we have studied the anisotropic piezoelectric properties of bone in the MHz range. Bone is known to be composed of collagen and hydroxyapatite (HAp) and shows strong elastic anisotropy. In this study, the effects of HAp on the piezoelectricity were investigated experimentally. To remove the HAp crystallites from the bovine cortical bone, demineralization was performed using ethylene diamine tetra-acetic acid (EDTA) solutions. To investigate the piezoelectricity, we have fabricated ultrasound transducers using the cortical bone or demineralized cortical bone. The induced electrical potentials due to the piezoelectricity were observed as the output of these transducers under pulsed ultrasound irradiation in the MHz range. The cortical bone transducer (before mineralization) showed anisotropic piezoelectric behavior. When the ultrasound irradiation was applied normal to the transducer surface, the observed induced electrical potentials had minimum values. The potential increased under off-axis ultrasound irradiation with changes in polarization. In the demineralized bone transducer case, however, the anisotropic behavior was not observed in the induced electrical potentials. These results therefore indicate that the HAp crystallites affect the piezoelectric characteristics of bone.

Formic acid demineralization does not affect the morphometry of cervical zygapophyseal joint meniscoids.

Science.gov (United States)

Farrell, Scott F; Osmotherly, Peter G; Rivett, Darren A; Cornwall, Jon

2015-01-01

Demineralization can facilitate the dissection of soft tissue structures in inaccessible locations by softening surrounding bone so that it can be easily removed without risking damage to the structure of interest. However, it is unclear whether demineralization alters the morphometry of soft tissues if used for this purpose. We have therefore examined the effect of extended-immersion formic acid demineralization on the size and shape of cervical zygapophyseal joint meniscoids to evaluate its usefulness as a means of facilitating dissection and examination of soft tissue structures from bony regions. Four cadaveric cervical spines were dissected, and three randomly selected zygapophyseal joints from each spine (12 in total) were removed, disarticulated and immersed in 5% formic acid for 32 days. Each joint was examined using a surgical microscope and photographed, and meniscoid length and surface area measured at days 0, 4, 18, and 32. Measurements were made on magnified digital photographs, and each measurement was repeated three times to determine intra-rater reliability. Data were analyzed using repeated-measures analysis of variance. Significance was set at p reliability was high (intra-class correlation > 0.9). These results support the use of formic acid demineralization to facilitate the study of cervical spine meniscoids by dissection, as even after a period of extended immersion in the solution, the morphometry of the structures was not significantly altered. Findings may have implications for dissection studies of other meniscoid-like soft tissue structures that use formic acid demineralization.

Colorimetric Models Used for Establishing the Optimal Dose for Sterilizing the Sea Buck thorn (Hippophae rhamnoides) Leaves Powder with Ionizing Radiation

International Nuclear Information System (INIS)

Minea, R.; Popescu, M.I.; Dumitrascu, M.; Sima, E.; Mitru, E.; Manea, St.; Mazilu, S.

2009-01-01

The current work intends to promote the development of the methods for establishing the degree of sterilization with ionizing radiations of the herbs in order to use them for obtaining food supplements, but also to obtaining medicines and cosmetic products. Obtaining the raw material, Sea Buckthorn (Hippophae rhamnoides) leaves, at a high level of sterilization without influencing the quality of active principles, is a desideratum of the economic agents in the area. The employed colorimetric methods have practically no impact on the studied herbs and, in the same time, they provide complex information on the effect of the ionizing radiations. The colorimetric methods allow to develop some models to be used both in the indirect evaluation of the microbial charge, before and after the treatment with ionizing radiations and for establishing the optimal necessary dose. The trials were made on Sea Buckthorn (Hippophae rhamnoides) leaves powder supplied by S.C. HOFIGAL EXPORT-IMPORT S.A. from Bucharest. The validation of the obtained colorimetric model was made through some spectrometric setups from the UV-Vis area, on the contents in: polyphenol carboxylic acids, flavones derivates, redox enzymes of superoxide dismutase type, and in the antioxidant activity

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).

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

International Nuclear Information System (INIS)

Bedward, D.A.; Brinston, R.M.; Kotler, J.

1995-01-01

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)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Savaris, M.; Santos, V. dos, E-mail: vsantos2@ucs.br; 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 (SH{sub 2}O{sub 2}), saturated steam (SSS), electron beam radiation (SEB) and gamma radiation (SGR). The samples of PLA{sub SEtO}, PLA{sub SH2O2}, PLA{sub SEB} and PLA{sub SGR} exhibited thermal and physical changes after being submitted to sterilization processes. PLA{sub SSS} showed morphological, chemical, thermal and physical changes. It is concluded that processes by SEtO, SH{sub 2}O{sub 2}, 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. - Highlights: • PLA was subjected to five different sterilization process. • All sterilization processes do not changed the hydrophilicity of PLA. • Morphological, chemical, physical and thermal changes were observed for the PLA{sub SSS}. • The sterilization by saturated steam is not recommended to sterilize PLA.

Radiation sterilization of absorbent cotton and of absorbent gauze

International Nuclear Information System (INIS)

Hosobuchi, Kazunari; Oka, Mitsuru; Kaneko, Akira; Ishiwata, Hiroshi.

1986-01-01

The bioburden of absorbent cotton and of absorbent gauze and their physical and chemical characteristics after irradiation are investigated. The survey conducted on contaminants of 1890 cotton samples from 53 lots and 805 gauze samples from 56 lots showed maximum numbers of microbes per g of the cotton and gauze were 859 (an average of 21.4) and 777 (an average of 42.2), respectively. Isolation and microbiological and biochemical tests of representative microbes indicated that all of them, except one, were bacilli. The sterilization dose at 10 -6 of sterlity assurance level was found to be 2.0 Mrad when irradiated the spores loaded on paper strips and examined populations having graded D values from 0.10 to 0.28 Mrad. The sterilization dose would be about 1.5 Mrad if subjected the average numbers of contaminants observed in this study to irradiation. No significant differences were found between the irradiated samples and control up to 2 Mrad in tensile strength, change of color, absorbency, sedimentation rate, soluble substances, and pH of solutions used for immersion and other tests conventionally used. These results indicate that these products can be sterilized by irradiation. (author)

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.

Study of fieldbus technology confiability when applied in a Sterilization plant control and safety systems

International Nuclear Information System (INIS)

Karma, D.; Sampa, M.H.O.; Rela, P.R.

2001-01-01

Several sterilization processes have been used in these years for treatment of countless products. Some processes use high temperatures, thermal shocks and chemical agents. With the discovery of the ionizing radiation and its posterior technological developments turned possible the application of that process, in 1960, also in the sterilization, denominated radiation sterilization. This process became also applied in another areas of health and industrial as food conservation, gemstones enhancement and others. The radiation sterilization requests an effective control and it needs a high level of safety. The commercial use of the computers applied in industrial automation provides and the domain of new technologies in this field provides news applications then new designs now is possible. The Fieldbus technology, a new digital communication protocol, like a Local Area Network, can be an alternative in the cobalt-60 irradiation plant. This paper show preliminary study about confiability in systems using Fieldbus technology. This technology was simulated in sterilization plant control and safety systems and the fail probability was quantified using Fail Tree Analysis Method. Fieldbus technology can be used in sterilization plants because the confiability in this systems is like PLCs and relays systems, was the conclusion

International standard (ISO) of radiation sterilization and issues in the sterilization dose setting

International Nuclear Information System (INIS)

Takehisa, Masaaki

1995-01-01

The ISO dose setting method 1 uses bioburden and verification by sublethal sterility test. Current devices produced in clean environmental have low bioburden, however, sensitivity of verification test declines at low bioburden. Validation of verification in this region should be further studied. A dose setting using D 10 of bioburden isolates should be reevaluated and included in the ISO. (author)

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...... was prepared and implanted in the abdominal muscle either without prior storage (control group) or after storage for 9 or 14 months at -70 degrees C or 4 degrees C (four experimental groups). Bone formation in the implants was evaluated quantitatively 4 weeks postoperatively by measuring the strontium 85...

Comparison of electron beam and gamma irradiation for the sterilization of allograft

International Nuclear Information System (INIS)

Jong il Choi; Nak Yun Sung; Hee Sub Lee; Jae Hun Kim; Myung Woo Byun; Ju Woon Lee

2008-01-01

Full text: For human use, it is necessary to sterilize the allograft in order to reduce the risk of infections and associated complications. In this study, we compared the effects of electron beam and gamma irradiation for the sterilization of the demineralized bone matrix (DBM) in a carboxymethylcellulose (CMC) carrier with regard to the physiological and osteoinductive properties. The CMC carrier was irradiated at the various doses. and the viscosity of the irradiated CMC was measured. The viscosity of the CMC irradiated with electron beam was higher than that with gamma ray. Also, the addition of vitamin C as the radical scavenger and irradiation at -70 degree C were shown to be effective in preventing the degradation of CMC by the irradiation. To investigate the effect of irradiation on the osteoinduction of DBM, alkaline phosphatase (ALP) activity with C2C12 cells was measured. The ALP activity of DBM in CMC was higher when irradiated with the electron beam compared with the gamma ray. The bone morphogenetic proteins (BMP) were extracted from DBM irradiated with electron beam and gamma ray, and it was found that the extraction efficiency of BMP was higher from DBM irradiated with the electron beam. This was reasoned for the higher APL activity of the electron beam irradiated DBM. With the advantages of electron beam such as short processing time, in-line processing, and low equipment cost, these results suggest that electron beam irradiation is recommendable for the sterilization of DBM allograft. (Author)

Induction of inherited sterility and sex ratio distribution due to exposure to substerilising doses of gamma radiation in cotton bollworm Earias vittella fabricius

International Nuclear Information System (INIS)

Tamhankar, A.J.; Shantharam, K.

2005-01-01

Substerilising doses of gamma radiation induced inherited sterility and sex ratio distortion in the cotton bollworm Earias vittella fabricius. Adults irradiated with 75 Gy and self-crossed, provided sterile F 1 adults, suitable for direct use in sterile insect technique (SIT). In case of 50 Gy, the F 1 adults, when backcrossed, produced F 2 progeny with sex ratio in favour of females (1: >3). With 25 Gy, a sex ratio distortion was recorded in F 1 (1 male: 2.25 females) and self-crossing of F 1 resulted in progeny with a sex ratio of 3:1. Backcrossing of the F 1 female produced F 2 progeny with a sex ratio of 1:5. These results have implications in improving cost/benefit ratio of SIT for this species. (author)

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)

Applying the sterile insect technique to the control of insect pests

International Nuclear Information System (INIS)

LaChance, L.E.; Klassen, W.

1991-01-01

The sterile insect technique involves the mass-rearing of insects, which are sterilized by gamma rays from a 60 Co source before being released in a controlled fashion into nature. Matings between the sterile insects released and native insects produce no progeny, and so if enough of these matings occur the pest population can be controlled or even eradicated. A modification of the technique, especially suitable for the suppression of the moths and butterflies, is called the F, or inherited sterility method. In this, lower radiation doses are used such that the released males are only partially sterile (30-60%) and the females are fully sterile. When released males mate with native females some progeny are produced, but they are completely sterile. Thus, full expression of the sterility is delayed by one generation. This article describes the use of the sterile insect technique in controlling the screwworm fly, the tsetse fly, the medfly, the pink bollworm and the melon fly, and of the F 1 sterility method in the eradication of local gypsy moth infestations. 18 refs, 5 figs, 1 tab

Effect of sub-sterilizing doses of gamma radiation on Spodoptera frugiperda (Smith) pupae

International Nuclear Information System (INIS)

Duarte Aguilar, J.A.; Arthur, Valter

1998-01-01

Studies were undertaken to verify the effects of sub-sterilizing doses of gamma radiations on pupae of Spodoptera frugiperda (Smith) and transfer of genetic heredity on the first and second generations. Statistical analysis showed difference in the ageing effect of gamma radiations on the larval phase and larval viability ranged between 72 and 94 percent, when irradiated (50 Gy) males or females were crossed with non-irradiated adults. With doses of 100, 125, 150 and 175 Gy the crossing of irradiated males x non irradiated females the larval viability was between 64 and 94 per cent in F-1 and F-2 generations. The duration and other life parameters of the pupae and adults did not differ from the controls. The egg laying ability was not affected by doses up to 150 Gy on both the sexes. If irradiated females with doses of 175 and 200 Gy were crossed with non-irradiated males, the egg laying was inhibited when males were irradiated with one of these doses, the offspring females did not lay eggs or laid non-fertile eggs. (author)

Postpartum Sterilization

Science.gov (United States)

f AQ FREQUENTLY ASKED QUESTIONS FAQ052 CONTRACEPTION Postpartum Sterilization • What is sterilization? • What is postpartum sterilization? • How is postpartum sterilization performed? • What kind of anesthesia is used for postpartum sterilization? • How ...

Demineralization of Sargassum spp. Macroalgae Biomass: Selective Hydrothermal Liquefaction Process for Bio-Oil Production

Energy Technology Data Exchange (ETDEWEB)

Díaz-Vázquez, Liz M., E-mail: limdiaz@uprrp.edu; Rojas-Pérez, Arnulfo; Fuentes-Caraballo, Mariela; Robles, Isis V. [Department of Chemistry, University of Puerto Rico Río Piedras Campus, San Juan, PR (United States); Jena, Umakanta [Bioenergy Laboratory, Desert Research Institute, Reno, NV (United States); Das, K. C. [College of Engineering, University of Georgia, Athens, GA (United States)

2015-02-11

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 spectroscopy, energy dispersive spectroscopy, scanning electron microscopy, 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.

Acid demineralization susceptibility of dental enamel submitted to different bleaching techniques and fluoridation regimens.

Science.gov (United States)

Salomão, Dlf; Santos, Dm; Nogueira, Rd; Palma-Dibb, Rg; Geraldo-Martins, Vr

2014-01-01

The aim of the current study was to assess the acid demineralization susceptibility of bleached dental enamel submitted to different fluoride regimens. One hundred bovine enamel blocks (6×6×3 mm) were randomly divided into 10 groups (n=10). Groups 1 and 2 received no bleaching. Groups 3 to 6 were submitted to an at-home bleaching technique using 6% hydrogen peroxide (HP; G3 and G4) or 10% carbamide peroxide (CP; G5 and G6). Groups 7 to 10 were submitted to an in-office bleaching technique using 35% HP (G7 and G8) or 35% CP (G9 and G10). During bleaching, a daily fluoridation regimen of 0.05% sodium fluoride (NaF) solution was performed on groups 3, 5, 7, and 9, while weekly fluoridation with a 2% NaF gel was performed on groups 4, 6, 8, and 10. The samples in groups 2 to 10 were pH cycled for 14 consecutive days. The samples from all groups were then assessed by cross-sectional Knoop microhardness at different depths from the outer enamel surface. The average Knoop hardness numbers (KHNs) were compared using one-way analysis of variance and Tukey tests (α=0.05). The comparison between groups 1 and 2 showed that the demineralization method was effective. The comparison among groups 2 to 6 showed the same susceptibility to acid demineralization, regardless of the fluoridation method used. However, the samples from groups 8 and 10 showed more susceptibility to acid demineralization when compared with group 2 (penamel to acid demineralization. However, the use of 35% HP and 35% CP must be associated with a daily fluoridation regimen, otherwise the in-office bleaching makes the bleached enamel more susceptible to acid demineralization.

Demineralization of Sargassum spp. Macroalgae Biomass: Selective Hydrothermal Liquefaction Process for Bio-Oil Production

International Nuclear Information System (INIS)

Díaz-Vázquez, Liz M.; Rojas-Pérez, Arnulfo; Fuentes-Caraballo, Mariela; Robles, Isis V.; Jena, Umakanta; Das, K. C.

2015-01-01

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 spectroscopy, energy dispersive spectroscopy, scanning electron microscopy, 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.

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.

Fluoride releasing and enamel demineralization around orthodontic brackets by fluoride-releasing composite containing nanoparticles.

Science.gov (United States)

Melo, Mary A S; Morais, Weslanny A; Passos, Vanara F; Lima, Juliana P M; Rodrigues, Lidiany K A

2014-05-01

Fluoride-containing materials have been suggested to control enamel demineralization around orthodontic brackets during the treatment with fixed appliances. The improvement of their properties has been made through innovations, such as the application of nanotechnology by incorporation of nanofillers. This in vitro study evaluated the capacity of fluoride releasing and enamel demineralization inhibition of fluoride-releasing nanofilled cement around orthodontic brackets using an artificial caries biofilm model. Forty bovine enamel discs were selected by evaluating surface microhardness and randomized into four groups (n = 10): non-fluoride-releasing microfilled composite, fluoride-releasing microfilled composite, resin-modified glass ionomer cement (RMGI), and fluoride-releasing nanofilled composite (FN). After brackets bonding in each disc, the specimens were subjected to a cariogenic challenge through a Streptococcus mutans biofilm model. After the experimental period, the biofilm formed around the brackets was collected for fluoride analysis and the mineral loss around the brackets was determined by integrated demineralization via cross-sectional microhardness measurement at 20 and 70 μm from the bracket margin. Additionally, samples of each group were subjected to energy-dispersive X-ray spectroscopy (EDX) analysis examined under a scanning electron microscopy (SEM). ANOVA followed by Tukey test were applied for fluoride concentration and mineral loss data, respectively. At both distances, only RMGI statistically differed from the other groups presenting the lowest demineralization, although there was a trend to a lower demineralization of enamel around brackets in FN group. Similar condition was found to fluoride concentration and EDX/SEM analysis. Under the cariogenic exposure condition of this study, the fluoride-releasing nanofilled material had similar performance to fluoride-releasing microfilled materials. The presence of nanofillers in the fluoride

Reverse osmosis using for water demineralization for supplying the NPP and TPP steam generators

International Nuclear Information System (INIS)

Mamet, A.P.; Sitnyakovskij, Yu.A.

2000-01-01

Paper analyzes the conditions affecting the efficiency of water reverse-osmosis demineralization for NPP and TPP steam generators and presents an example of efficient application of a membrane reverse-osmosis facility serving as the first stage of water demineralization at the Mosehnergo Joint-Stock Company heating and power plant no. 23 to feed boilers [ru

Sterilization by Gamma-Radiation of the Sodium Salt of p-Amino-Salicylic Acid

International Nuclear Information System (INIS)

Bellion, B.; Denti, E.; Massagli, A.

1963-01-01

Sodium p-amino-salicylate cannot be sterilized thermally. During manufacture or packing for medical purposes it must therefore be handled under sterilized conditions, with all the difficulties which this involves. The paper quotes experimental data to show that, using gamma irradiation, the product may be sterilized without damage and without the formation of substances harmful from the medical standpoint. (author) [fr

Revisiting cosmological bounds on sterile neutrinos

Energy Technology Data Exchange (ETDEWEB)

Vincent, Aaron C. [Institute for Particle Physics Phenomenology (IPPP), Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Martínez, Enrique Fernández [Departamento and Instituto de Física Teórica (IFT), UAM/CSIC, Universidad Autonoma de Madrid, C/ Nicolás Cabrera 13-15, E-28049 Cantoblanco, Madrid (Spain); Hernández, Pilar; Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Lattanzi, Massimiliano, E-mail: aaron.vincent@durham.ac.uk, E-mail: enrique.fernandez-martinez@uam.es, E-mail: m.pilar.hernandez@uv.es, E-mail: omena@ific.uv.es, E-mail: lattanzi@fe.infn.it [Dipartimento di Fisica e Science della Terra, Università di Ferrara and INFN, sezione di Ferrara, Polo Scientifico e Tecnologico, Edificio C Via Saragat, 1, I-44122 Ferrara (Italy)

2015-04-01

We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R{sub CMB} and the sound horizon r{sub s} from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin{sup 2}θ ∼< 0.026 (m{sub s}/eV){sup −2}.

Effect of white tea and xylitol on structure and properties of demineralized enamel and jawbone

Science.gov (United States)

Auerkari, EI; Kiranahayu, R.; Emerita, D.; Sumariningsih, P.; Sarita, D.; Adiwirya, MS; Suhartono, AW

2018-05-01

White tea and xylitol have been suggested as potential agents to combat dental caries and osteoporosis through enhanced remineralization. This investigation aimed to determine the effects of exposure to white tea with and without xylitol on the structure, composition and hardness of demineralized human dental enamel. For control, samples of untreated and demineralized enamel and samples of untreated rat jawbone were subjected to similar measurements. For demineralization, the enamel samples were immersed for two days at 50°C in an acetate solution (pH 4.0). All samples were then soaked for two weeks at 37°C in a solution containing three different concentrations of white tea, xylitol or both, and an optional addition of the remineralization ingredients including Ca, P and F. For enamel samples without preceding demineralization and without added remineralization ingredients, the results showed highest mean hardness after immersion in a solution containing both white tea and xylitol, practically independently of their applied concentration level. However, for demineralized enamel samples with added remineralization ingredients, the resulting mean hardness was also dependent on concentration of white tea and xylitol. With sufficient concentration, hardness was again higher for combined white tea and xylitol than for either of these used alone.

Degradation and stability of polycarbonate sterilized by gamma rays

International Nuclear Information System (INIS)

Araujo, E.S.; Guedes, S.M.L.

1995-01-01

The purpose of this paper is to study the behavior of the polycarbonate (poly (bis phenol-A carbonate)) when it is sterilized by gamma rays because undesirable discoloration appears. Aromatic polycarbonates are amorphous polymers usually prepared from bis phenols and phosgene by interfacial polymerization. They are employed in medical applications, including blood filters, dialyzers, oxygenators and sterilizing equipment. At present, the best process for sterilization of medical supplies is present, the best process for sterilization of medical supplies is gamma irradiation. The two major effects of γ-radiation in polymers are crosslinking and main chain scission. Both effects coexist and either one may predominate depending on the chemical structure of the polymer and the conditions of irradiation. (author). 5 refs, 6 figs, 1 tab

Study on the Chinese traditional drugs' sterilization and disinfestation by radiation and their biological effects

International Nuclear Information System (INIS)

Ma Shouxiang; Yang Ruikun; Liu Desheng

1987-01-01

The study of the sterilization and disinfestation by 60 Co γ-radiation and their biological effects on tuber of elevated gastrodia, Chinese angelica and Dangshen have been carried out. The experimental results show that optimal dose was 2 x 10 5 - 4 x 10 5 rad to kill insect in the three Chinese traditional drugs. The results also show that the content of the chemical composition of irradiated group is similar to control group under 6 x 10 5 rad. The thin-layer chromatography colour-maculae are almost the same. They have the same Rf exponent

Radio resistibility of micro-organism and sterilization by ionizing radiation

International Nuclear Information System (INIS)

Tran Que; Tran Tich Canh; Hoang Hung Tien; Le Xuan Tham; Le Thi Dinh

2000-01-01

Pasteur ella pestis is a radiosensitive bacterium. The irradiation of P. pestis by gamma rays for the investigation of radiation sterilization with dose rate of 261 rads/s calculated the values of D 10 = 5.668 Krads and D q = 4.044 Krads. The responsive curve of dose-survival effect had a simple phase, shoulder and none detail effect. The survival frequencies of P. pestis after doses 30 Krads fixed 3.45x10 -5 . Using the survival P. pestis isolated from the first exposure for the second exposure and third exposure showed that the survival frequencies after 3 times were stable with 3.45x10 -5 ± 0.87x10 -5 . The survival frequency of P. pestis at dose 30 Krads was clearly high after 4th exposing time. The small colony isolated after 4th exposing time was a resistant line to gamma rays. This line also was dispersed by specific phage. The responsive curve of dose-survival effects had a simple phase, shoulder and none detail effect. (author)

Searching for a strategy to gamma-sterilize Portuguese cork stoppers - preliminary studies on bioburden, radioresistance and sterility assurance level

International Nuclear Information System (INIS)

Botelho, M.L.; Almeida-Vara, E.; Andrade, M.E.; Tenreiro, R.

1988-01-01

A gamma radiation plant will start running next year in Portugal, to sterilize medical devices and wine cork stoppers. As Portugal is the first world producer, manufacturer and exporter of wine cork stoppers, an efficient sterilizing procedure is required to overcome moulding from long term shipping. Preliminary research on cork stoppers bioburden and microflora radioresistance allowed to establish reliable D 10 and Sterility Assurance Level (SAL) values. Studied samples showed an initial average contamination of about 10 4 c.f.u. per cork stopper. The determined D 10 values for fungi were not higher than 2 kGy. In these conditions, a SAL of 10 -4 can be expected when the product is treated at a minimum absorbed dose of 15 kGy. (author)

Hysteroscopic Sterilization

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... sterilization? Sterilization is a permanent form of birth control. What is tubal sterilization? Sterilization procedures for women are ... is quicker than from other types of sterilization. What are the risks of ... on for birth control. • There is a risk of injury to the ...

Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ.

Science.gov (United States)

Wierichs, Richard J; Lausch, Julian; Meyer-Lueckel, Hendrik; Esteves-Oliveira, Marcella

2016-01-01

The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (x0394;x0394;Z) and lesion depth (x0394;LD) were calculated between values before and after the in situ period using transversal microradiography. Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for x0394;x0394;Z of the dentifrice with 0 ppm F, sound surfaces showed significantly higher x0394;x0394;Z and x0394;LD values compared with lowly and highly demineralized lesions (p test). Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth. © 2016 S. Karger AG, Basel.

Thixotropic gel-like composition and sterile blood-collecting and separating device

International Nuclear Information System (INIS)

Semersky, F.E.

1980-01-01

A thixotropic gel-like composition comprising liquid polybutadiene and an inorganic inert filler dispersed therein is adapted for use as a sealing barrier between separated phases of differing densities of a fluid in which said composition has at rest a density intermediate said differing densities, said gel-like composition being substantially resistant to sterilizing radiation. There is also disclosed a pre-packaged blood collecting and separating device which contains a mixture of liquid polybutadiene and an inorganic, inert filler, such as silica, as a thixotropic gel adapted at rest to form a sealing barrier between separated blood phases. The device and gel are subjected to sterilizing radiation to form a substantially sterile device, substantially free of backflow contamination without degradation of the physical properties of the gel. (author)

Morphological and chemical changes of dentin after applying different sterilization methods

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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.

Supercritical Carbon Dioxide–Based Sterilization of Decellularized Heart Valves

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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

Controlling Aedes aegypti population as DHF vector with radiation based-sterile insect technique in Banjarnegara Regency, Central Java

International Nuclear Information System (INIS)

Siti Nurhayati; Bambang Yunianto; Tri Ramadhani; Bina Ikawati; Budi Santoso; Ali Rahayu

2013-01-01

The control program of dengue hemorrhagic fever (DHF) in Indonesia is still a problem due to the incomplete integrated handling. Sterile insect technique (SIT) for Aedes aegypti as DHF vector was considered as a potential strategy for controlling the DHF. A preliminary survey was carried out to determine the characteristic of A aegypti population in the study site before the implementation of SIT. The implementation of radiation based-SIT was carried out in Krandegan and Kutabanjar Villages of Banjarnegara Regency, Central Java which involved 99 houses. One hundred gamma rays irradiated male mosquitoes were released to each house up to five times. The eggs, larvae and adult mosquitoes were collected using ovitrap and weekly observed. The initial population density of A. aegypti in the studied area was obtained to be 6 mosquitoes per house with the mean index of house was 15.86% and the mean sterility of sterilized mosquitoes was 79.16%. The SIT effectively reduced A. aegypti population after the fifth release of irradiated mosquitoes into the houses. It can be assumed that the SIT was effective in controlling DHF vector in the studied area, nevertheless, it will be more effective if it is combined with other handling techniques. (author)

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.

Radiation processing and sterilization

International Nuclear Information System (INIS)

Takehisa, M.; Machi, S.

1987-01-01

This growth of commercial radiation processing has been largely dependent on the achievement in production of reliable and less expensive radiation facilities as well as the research and development effort for new applications. Although world statistics of the growth are not available, Figure 20-1 shows steady growth in the number of EBAs installed in Japan for various purposes. Growth rate of Co-60 sources supplied by AECL (Atomic Energy of Canada Limited), which supplied approximately 80% of the world market, approximately 10% per year, including future growth estimates. Potential applications of radiation processing under development are in environmental conservation (e.g., treatment of sewage sludge, waste water, and exhaust gases) and bioengineering (e.g., immobilization of bioactive materials). The authors plan to introduce her the characteristics of radiation processing, examples of its industrial applications, the status of its research and development activities, and an economic analysis

Sterilization of DACUS CUCUMIS FRENCH (DIPTERA: TEPHRITDAE) by gamma radiation

International Nuclear Information System (INIS)

Hooper, G.H.S.

1976-01-01

When newly emerged adult Dacus cucumis French were irradiated in nitrogen, following a 15 min exposure to an atmosphere of pure nitrogen, the degree of sterility induced by a given dose was less than that obtained with the same dose in air. To achieve sterility in males of approximately 98 per cent doses of 7 krad in air and 13 krad in nitrogen were required. With females, total sterility through infecundity was achieved by 6 krad in air and 13 krad in nitrogen. Based on the hatch of eggs from competitive mating tests, males receiving 14 krad in nitrogen were significantly more competitive than males given 9 krad in air. The optimal light intensity for mating of D. cucumis under artificial conditions was 16.2, 1x. With this light intensity the mating propensity of males irradiated with 9 and 11 krad in air was significantly less than that of untreated males. The mating propensity of males given 14 krad in nitrogen approximated that of untreated males. (author)

In vitro demineralization of enamel by orange juice, apple juice, Pepsi Cola and Diet Pepsi Cola.

Science.gov (United States)

Grobler, S R; Senekal, P J; Laubscher, J A

1990-12-01

Enamel demineralization was studied over periods related to normal use of an orange juice, an apple juice, Pepsi Cola and Diet Pepsi Cola. Rectangular blocks of intact human enamel (3 mm x 3 mm) were cut from teeth, coated with nail varnish except for the enamel surface and exposed to the drinks for 2, 4, 5, 6 or 40 minutes. The amount of calcium released from the enamel into solution was determined with the use of an atomic absorption spectrophotometer. The results showed the following degree of enamel demineralization: Pepsi Cola = orange juice greater than apple juice greater than Diet Pepsi Cola. The results suggest that diet colas are less demineralizing than other acid drinks, and complementary plaque studies indicate that they are also less cariogenic. The study emphasized the importance of acid-type, buffer capacity, pH and the presence of other components on the degree of enamel demineralization.

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.

Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units.

Science.gov (United States)

Mousavinasab, Sayed-Mostafa; Khoroushi, Maryam; Moharreri, Mohammadreza; Atai, Mohammad

2014-08-01

Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05). Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units

Directory of Open Access Journals (Sweden)

Sayed-Mostafa Mousavinasab

2014-08-01

Full Text Available Objectives Light-curing of resin-based materials (RBMs increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs of three different RBMs using quartz tungsten halogen (QTH and light-emitting diode (LED units (LCUs. Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12 during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey, a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE, and a giomer (Beautifil II, Shofu GmbH, was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05. Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

Trends in sterilization since the introduction of Essure hysteroscopic sterilization.

Science.gov (United States)

Shavell, Valerie I; Abdallah, Mazen E; Shade, George H; Diamond, Michael P; Berman, Jay M

2009-01-01

To investigate trends in sterilization in women at the Detroit Medical Center, Michigan (DMC), since the introduction of Essure hysteroscopic sterilization. Retrospective study (Canadian Task Force classification II-2). Outpatient surgery center and university teaching hospitals. Women who underwent interval sterilization procedures at the DMC (Hutzel Women's Hospital, Sinai-Grace Hospital, and the Berry Center) and postpartum sterilization procedures at Hutzel Women's Hospital between January 1, 2002, and December 31, 2007. Permanent sterilization procedures including minilaparotomy tubal ligation, laparoscopic sterilization, Essure hysteroscopic sterilization, and postpartum tubal ligation performed at the time of cesarean section or after vaginal delivery. In all, 5509 permanent sterilization procedures were performed in the 6 years between January 1, 2002, and December 31, 2007, at the DMC facilities analyzed: 2484 interval sterilization procedures at Hutzel Women's Hospital, Sinai-Grace Hospital, and the Berry Center, and 3025 postpartum tubal ligations at Hutzel Women's Hospital. From 2002 through 2007, the decrease in laparoscopic sterilizations from 97.9% to 48.5% of all interval sterilization procedures corresponded significantly with the increase in Essure hysteroscopic sterilizations from 0.0% to 51.3% (p Essure hysteroscopic sterilizations increased significantly from 0.0% to 51.3% of all procedures. Since the approval of Essure hysteroscopic sterilization in November 2002, this minimally invasive method of hysteroscopic sterilization has increased in popularity at the DMC.

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.

Studies on mating competitiveness of sterile oriental fruit fly, Bactrocera dorsalis (Hendel)

International Nuclear Information System (INIS)

Limohpasmanee, W.; Segsarnviriya, S.

1998-01-01

An essential prerequisite for insect control by the sterile insect technique releasing method is mass rearing and sterilizing that do not have adverse effects on longevity and mating behavior of the released males. But many laboratory studies have shown that males irradiated at the completely sterility dose often could not compete with untreated males in mating. This paper studies the effects of gamma radiation at the sterile dose on mating, sexual and sperm competitiveness of the oriental fruit fly, Bactrocera dorsalis (Hendel) under the laboratory condition. It is found that irradiation at the completely sterility dose (90 Gy) had reduced the mating and sperm competition ability of the males. Though the sexual competition was not

Effect of ionizing radiations on bacterial endotoxins: comparison between gamma radiations and accelerated electrons

Energy Technology Data Exchange (ETDEWEB)

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

1988-01-01

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/sup -6/).

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

International Nuclear Information System (INIS)

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

2013-01-01

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. - 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

Present studies on the radio-sterilized drugs; Aktualny stan badan nad lekami sterylizowanymi radiacyjnie

Energy Technology Data Exchange (ETDEWEB)

Marciniec, B; Dettlaff, K [Department of Pharmaceutical Chemistry, Poznan University of Medical Sciences, Poznan (Poland)

2007-07-01

Lecture presents present status of radiosterilization of drugs and medical materials as compared to other sterilization methods. Literature review is shown on degradation of different kinds of drugs sterilized upon action of the sterilising doses of radiation.

Country status of application, manufacturing and sterilization of single-use medical products

International Nuclear Information System (INIS)

Norimah Yusof

1986-01-01

The paper reviews the current status of application of single-use medical products in Malaysia. The status of their manufacturing and sterilization is also discussed. The increasing production of such items calls for a more reliable and efficient sterilization technique in particular, radiation sterilization. In line with the demand and the effort to increase local production of medical products, UTN would be providing irradiation service together with research and development in this particular field by 1988. (author)

Effect of light-curable fluoride varnish on enamel demineralization adjacent to orthodontic brackets: an in-vivo study.

Science.gov (United States)

Mehta, Anurag; Paramshivam, Ganesh; Chugh, Vinay Kumar; Singh, Surjit; Halkai, Sudha; Kumar, Santosh

2015-11-01

The purpose of this in-vivo study was to evaluate the effect of a single application of Clinpro XT (3M ESPE, Pymble, New South Wales, Australia), a light-curable fluoride varnish, on enamel demineralization adjacent to orthodontic brackets. Thirty-eight patients (152 teeth) whose orthodontic treatment involved extraction of 4 first premolars were recruited. Two premolars each were assigned to the control group (no treatment) and the experimental group (received fluoride varnish application). The study was designed as a nonrandomized split-mouth study in which diagonally opposite quadrants received the same treatment. After the bonding procedures, a sectional T-loop was ligated into each bracket to serve as a site for plaque retention for enhanced demineralization. Clinpro XT was applied on the buccal surfaces adjacent to the brackets on all teeth in the experimental group only. Teeth in both groups were extracted after 15 days (n = 30), 30 days (n = 30), 45 days (n = 30), 90 days (n = 18), and 120 days (n = 18). Buccolingual sections were then evaluated under polarized light microscopy. After we excluded the dropouts, the mean depth of the demineralized enamel lesions was measured in final sample of 126 teeth. The Mann-Whitney test was used for comparison of the groups. In the control group, the depths of the demineralized enamel lesions increased from 30 to 120 days, whereas in the experimental group no sign of demineralization was noted throughout the observation period except for 3 teeth. Significant differences in the depths of demineralized lesions were found between the study groups. Clinpro XT light-curable fluoride varnish may be a reasonable alternative in the reduction of enamel demineralization around orthodontic brackets, especially in noncompliant and high-risk patients. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

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.

Comparison Study of Water Demineralization System for the OPR 1000 and AP 1000 Nuclear Power Plant

International Nuclear Information System (INIS)

Dedy Priambodo; Siti Alimah; Erlan Dewita

2009-01-01

OPR 1000 adopts demineralization method based on ion exchanger resin and AP 1000 adopt the method that based on Reverse Osmosis (RO)-Electrodeionization (EDI). The Ion exchange process is a reversible chemical reaction of a solution and an insoluble solid. Ion exchanger use resin as polluter ions capture and will be regenerated after its saturated. RO is method using pressure to force a solution through a membrane, retaining the solute on one side and allowing the pure solvent to pass to the other side. Whereas, EDI is a combination of ion exchange and electrodialysis. The ions is taken by ion exchange resin, and then it is discharged utilizing electric potential difference. Due to water splitting phenomena in EDI, make resin will never be saturated, so the RO-EDI process is water demineralization system that use little chemical, more simple installation, capable to maintain demineralization water product quality and environmental friendly. Thereby, The RO-EDI water demineralization system is more advance then ion exchange technology. (author)

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.

Triple-membrane reduces need for ion exchange regeneration

International Nuclear Information System (INIS)

Valcour, H.

1989-01-01

Triple-membrane water treatment systems are comprised of ultrafiltration units for pretreatment, electrodialysis reversal primary demineralizers, reverse osmosis secondary demineralizers, portable ion exchange unit polishing demineralizers, and ultraviolet sterilizers. The triple-membrane process is designed to provide an unprecedented degree of pretreatment to maximize efficiency, durability and reliability of the reverse osmosis, whilst reducing the required regeneration frequency of the ion exchange demineralizer by one to two orders of magnitude. (author)

Factors involved in planning radiation-sterilization practices and technology in the developing countries, and the Agency's promotional role

International Nuclear Information System (INIS)

Mukherjee, R.N.; Yuan, H.C.

1975-01-01

The application of ionizing radiation for sterilizing ready-to-use medical supplies, sutures and grafts provides a broad scope for the up-grading of public health care and family planning programmes in the developing countries. Sterile ready-to-use medical supplies become particularly important for improving the standard of those services given through the improvised camp-hospitals and mobile medical units for the remote areas of such countries, if needed. The practices generated in the technologically advanced countries will form the basis of the planning, but the necessary adjustments should be made in their implementation to suit best the local conditions and needs and to promote utilization of local raw materials. Necessary research and development and an effective infrastructure should be emphasized. Plastic materials are among the major pollutants of the environment. Timely parallel practical steps need be adopted and an action programme planned to preserve the quality of the human environment. (author)

Insect population control by the sterile-male technique

International Nuclear Information System (INIS)

Lindquist, A.W.

1963-01-01

The successful use of the sterile male technique to eradicate the screw worm fly from the Southeastern part of the United States showed that a new biological method using radiation-sterilized insects could not only control but also eradicate harmful insect pests. A panel of experts met at the IAEA in Vienna in October 1962 to discuss the various aspects and applications of this new technique and to assess its usefulness and limitations. This report summarizes the panel proceedings. 42 refs, 18 figs, 1 tab

Insect population control by the sterile-male technique

Energy Technology Data Exchange (ETDEWEB)

Lindquist, A W

1963-10-01

The successful use of the sterile male technique to eradicate the screw worm fly from the Southeastern part of the United States showed that a new biological method using radiation-sterilized insects could not only control but also eradicate harmful insect pests. A panel of experts met at the IAEA in Vienna in October 1962 to discuss the various aspects and applications of this new technique and to assess its usefulness and limitations. This report summarizes the panel proceedings. 42 refs, 18 figs, 1 tab.

Mechanisms of male sterility in higher plants

International Nuclear Information System (INIS)

Ohta, Yasuo

1982-01-01

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. (Kaihara, S.)

Studies of the ecology of insects sterilized artificially (gamma radiation), 10

International Nuclear Information System (INIS)

Kiyoku, Masao

1976-01-01

Progenies of a combination, T#male# x T#female# (a dose of 2.5 KR from 137 Cs), showed a striking inherited sterility until the fourth generation when the mating was made between inbred lines of the combination. In combinations that irradiated flies were crossed as either male or female with unirradiated ones, some inherited sterility was found in the first and second generations, and was almost entirely disappeared after the third of fourth generation. However, conspicuous inherited sterility was maintained through thirteen generations when progeny flies from the combination of T#male# x U#female#, which was irradiated by a dose of 7.5 KR, were inbred. From cytological studies, it is observed that the oriental fruit fly has chromosome number of n=6 both in salivary gland cells and in meiotic division. An amitosis like cell division occured among meiotic cells of irradiated male flies and those of male progenies that had been mated with unirradiated females. Several different types of chromosome aberrations were found frequently in the salivary gland chromosomes of flies showing inherited sterility. By statistical analysis, the relationship between the second power of frequency (X) of the chromosome aberration and hatchability (Y) of eggs laid was showed to be a straight regression equation, Y=40.69 - (X - 18.75)*. The correlation-coefficient (r), -867* was obtained. (auth.)

The possibilities of sterilization of media and medium ingredients by ionizing gamma radiation

International Nuclear Information System (INIS)

Pogany, I.

1979-01-01

The thermoshock originated from sterilization by heat can occasionally destroy the media to such an extent that the growth can start only at dilutions 2 to 3 power less than in control media sterilized by glass filtration. There are some ingredients which could be produced by an aseptic procedure only - e.g. egg yolk extract - as they are not sterilizable by filtration or heat. Solid and liquid culture media prepared from natural substances and ingredients such as serum or egg yolk extract, etc. can successfully be sterilized by 1 Mrad integrated dose in 500 ml volume irrespective of dispension. In the culture media prepared with substances from natural sources it was impossible to demonstrate any radiochemical destroying effect using colony counting method, and these media were so sensitive as if they had been sterilized by glass filtration. With these substances sterilization by irradiation proved to be an applicable method in industry. Radiochemical effect was demonstrable in two cases only: the phenol-red indicator has decolorized and after a long period of storage it showed inclination to recombine, and potassium-tellurite has been precipitated owing to the above mentioned dose of irradiation. (author)

Microbiological method for radiation sterilization (III). Development of identification software of spore-forming bacteria by using BBL CRYSTAL GP identification kit

International Nuclear Information System (INIS)

Hironiwa, Takayuki; Yamamoto, Yoko; Koshikawa, Tomihiko

2004-01-01

The part III in this title series describes the development of software for identification of spore-forming bacteria using the commercially available BBL CRYSTAL GP Identification Kit (Becton, Dickinson and Co., Ltd.), which is essentially for identification of Gram positive bacteria and is not always suitable for the spore-former in the radiation sterilization of medical devices. Isolation and identification of a spore-forming bacterium have to be confirmed by phase-contrast microscopy. The bacteria cultured overnight are to be inoculated in the Kit and cultured for 18-24 hr at 35-37 deg C with the lid attached by substrates for identification. Here, 30 substrates and probability of positive reactions to the substrates have been tested for spore-formers to make the computer software for final identification. The system is possible to identify 13 spp. of Bacillus, 4 of Paenibacillus, 2 of Brevibaccilus and 1 of Virgibacillus, which are the usual bioburden. For possible misidentification, re-isolation of the bacterium, prolonged culture, concentrated inoculation and re-consideration for ranking of identification the software provides are necessary as well as other identification approaches. Thus, as described in this series, the radio-resistance of, and radiation dose for, the bioburden can be evaluated more easily than hitherto, with use of the kits in radiation sterilization. (N.I.)

Sterilization of biological tissues with ionizing radiation

International Nuclear Information System (INIS)

Reyes F, M.L.; Martinez P, M.E.; Luna Z, D.

1997-01-01

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)

Spread ability of diamondblack moth (Plutella xylotella L) steriled by irradiation

International Nuclear Information System (INIS)

Yang Rongxin; Fang Julian; Xia Darong; Chu Jiming; Feng Chunsheng

1990-01-01

The spread ability of the radiation steriled diamondblack moth (DBM) is reported. It shows that the 94.2% of DBM is spread in 40 m duration of 10 days and a few of moths are 120 m. It indicates that the spread of steriled DBM is definitely time limit, the spread area is withinca. 700 m 2 in the first three days

Determination of the sterilizing gamma radiation dose of 60Co to ACANTHOSCELIDES OBTECTUS imagos (col. bruchidae)

International Nuclear Information System (INIS)

Arthur, V.; Wiendl, F.M.; Sgrillo, R.B.; Campanhola, C.

1980-01-01

This paper relates the results of experiments dealing with irradiation of adults of Acanthoscelides obtectus (Say, 1831). The insects were irradiated with doses of 0 (control), 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 20 krad gamma radiation of a 60 Co source. After irradiation, the adults were kept for observation on beans (Phaseolus vulgaris) var. Jalo, in a controlled environmen t chamber at 30 +- 1 0 C and 70 +- 5% relative humidity. Continuous weighing at weekly intervals was done 22 times, showing, by weight loss in percent, that the sterilizing dose for adults was 10,65 krad. It could also be observed that losses of less than 0,5% occured at 9 krad. For a possible employment on commercial scale, the ideal radiation dose for bean desinfestation would be 10 krad, after which no weight loss occurrence. (Author) [pt

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

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

International Nuclear Information System (INIS)

Takahashi, T.

2004-01-01

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

'Gornooriahovska Kapia F1' - A new hybrid pepper variety based on radiation induced male sterility

International Nuclear Information System (INIS)

Daskalov, S.

2001-01-01

The female parent line 'Zlaten medal ms-8' was obtained by Daskalov as a gamma rays induced mutant of pepper (Capsicum annum L.). Dry seeds of the initial variety 'Zlaten medal' were irradiated with 135 Gy gamma rays and after screening of a large M 2 population (57,000 plants) 3 male sterile mutants were obtained. After an allelic test the genes responsible for male sterility were denoted as ms-6, ms-7, and ms-8. After many years of testing various male sterility sources the gene ms-8 proved to be the most suitable for hybrid seed production because it determines 100% male sterility, independent of the climatic condition or the genotype. The mutation causes the highest reduction of anthers, which allows easy distinction between male sterile and fertile flowers. The development of the mutant male sterile line Zlaten medal ms-8 is a good example of how mutation techniques can be very useful for adding or changing only one trait without altering the basic genotype

Sterilization of allograft bone: is 25 kGy the gold standard for gamma irradiation?

Science.gov (United States)

Nguyen, Huynh; Morgan, David A F; Forwood, Mark R

2007-01-01

For several decades, a dose of 25 kGy of gamma irradiation has been recommended for terminal sterilization of medical products, including bone allografts. Practically, the application of a given gamma dose varies from tissue bank to tissue bank. While many banks use 25 kGy, some have adopted a higher dose, while some choose lower doses, and others do not use irradiation for terminal sterilization. A revolution in quality control in the tissue banking industry has occurred in line with development of quality assurance standards. These have resulted in significant reductions in the risk of contamination by microorganisms of final graft products. In light of these developments, there is sufficient rationale to re-establish a new standard dose, sufficient enough to sterilize allograft bone, while minimizing the adverse effects of gamma radiation on tissue properties. Using valid modifications, several authors have applied ISO standards to establish a radiation dose for bone allografts that is specific to systems employed in bone banking. These standards, and their verification, suggest that the actual dose could be significantly reduced from 25 kGy, while maintaining a valid sterility assurance level (SAL) of 10(-6). The current paper reviews the methods that have been used to develop radiation doses for terminal sterilization of medical products, and the current trend for selection of a specific dose for tissue banks.

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

Science.gov (United States)

Ghanbarzadeh, Majid; Akbari, Majid; Hamzei, Haniye

2015-01-01

Background 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. Material and Methods 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. Results Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (pTooth whitening through home 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. PMID:26330939

Lactic acid demineralization of shrimp shell and chitosan synthesis

Directory of Open Access Journals (Sweden)

Alewo Opuada AMEH

2015-05-01

Full Text Available The use of lactic acid was compared to hydrochloric acid for shrimp shell demineralization in chitosan synthesis. Five different acid concentrations were considered for the study: 1.5M, 3.0M, 4.5M, 6.0M and 7.5M. After demineralization, the shrimp shell were deproteinized and subsequently deacetylated to produce chitosan using sodium hydroxide solution. The synthesized chitosan samples were characterized using solubility, FTIR, SEM, XRD and viscosity. The SEM, FTIR and XRD analysis indicated that chitosan was synthesized with a high degree of deacetylation (83.18±2.11 when lactic acid was used and 84.2±5.00 when HCl was used. The degree of deacetylation and the molecular weight of the chitosan samples were also estimated. ANOVA analysis (at 95% confidence interval indicated that acid type and concentration did not significantly affect the solubility, degree of deacetylation, viscosity and molecular weight of the chitosan within the range considered.

In vitro study of the diode laser effect on artificial demineralized surface of human dental enamel

International Nuclear Information System (INIS)

Ebel, Patricia

2003-01-01

In scientific literature there are many reports about fusion and resolidification of dental enamel after laser irradiation and their capability to generate surfaces with increased resistance to demineralization compared to non-irradiated areas. The use of high power diode laser on demineralized surfaces of human dental enamel is presented as a good alternative in caries prevention. The purpose of this study is to investigate the morphological changes produced by the use of one high power diode laser on human dental enamel surface after demineralization treatment with lactic acid, under chosen parameters. Fifteen samples of human dental molars were used and divided in four groups: control - demineralization treatment with lactic acid and no irradiation, and demineralization treatment with lactic acid followed of irradiation with 212,20 mJ/cm 2 , 282,84 mJ/cm 2 and 325,38 mJ/cm 2 , respectively. The samples were irradiated with high power diode laser (808 nm) with a 300 μm diameter fiber optics. Black ink was used on enamel surface to enhance the superficial absorption. The samples were studied by optical microscopy and scanning electron microscopy. Modifications on the enamel surfaces were observed. Such modifications were characterized by melted and re-solidified region of the enamel. According with our results the best parameter was 2.0 W, presenting the most uniform surface. The use of high power diode laser as demonstrated in this study is able to promote melting and re-solidification on human dental enamel. (author)

Effect of Oxytetracycline on In vitro Mineralization and Demineralization Reactions in the Absence and Presence of Collagen

Directory of Open Access Journals (Sweden)

Monica Kakkar

2017-11-01

Full Text Available Introduction: Oxytetracycline and its derivatives are routinely used to treat various ailments have also been shown to inhibit embryonic bone formation, mineralization in pregnant female rats and parathyroid hormone induced demineralization of bones. Oxytetracycline has also been routinely used as bone fluorochrome to study bone metabolism. However, despite the above observations, its mechanism of action is not clearly understood. Some studies tend to suggest that it acts by inhibiting collagen biosynthesis while others indicate that it acts without influencing collagen metabolism. Aim: To study the mechanism by which oxytetracycline influences the mineralization and demineralization reactions. Materials and Methods: Homogeneous and heterogeneous systems of in vitro mineralization under physiological conditions of temperature, pH and ionic strength were used to investigate the effect of oxytetracycline not only on initial mineral phase formation but also on its subsequent growth or demineralization. In the Homogenous system, supersaturated conditions with respect to calcium and phosphate ions were employed to study their precipitation as mineral phase resembling hydroxyapatite in nature. However, in the heterogeneous system, collagen isolated from sheep tendons was used to induce identical mineral phases under saturated conditions with respect to calcium and phosphate ions prevailing in the body fluids. Results: The study demonstrated that in the homogeneous reaction system (mineralization in the absence of collagen oxytetracycline inhibited both the initial mineral phase formation and its subsequent growth without influencing its demineralization. However, in the heterogeneous system, oxytetracycline was found to inhibit not only the initial mineralization but also its subsequent growth or demineralization. Conclusion: Oxytetracycline acted like crystal poisons to inhibit the mineralization and demineralization reactions by tightly associating

Influence of fluoride varnish on shear bond strength of a universal adhesive on intact and demineralized enamel.

Science.gov (United States)

Ortiz-Ruiz, Antonio José; Muñoz-Gómez, Iban Jesús; Pérez-Pardo, Ana; Germán-Cecilia, Concepción; Martínez-Beneyto, Yolanda; Vicente, Ascensión

2018-04-27

The aim was to evaluate the effect of fluoride varnish on the shear bond strength (SBS) on polished and non-polished intact and demineralized enamel. Bovine incisors (half demineralized) were used. Bifluorid 12™ was applied. Bonding was made with Futurabond ® M + and GrandioSO, 24 h and 7 days after varnishing. In some groups, varnish was removed by polishing before bonding. SBS was measured. Fracture type was determined by stereomicroscopy and scanning electron microscope (SEM) observations of the enamel surface were made. Between-group differences were determined by one-way ANOVA and the Tukey test. Associations between study factors and fracture modes were analysed using contingency tables and Pearson's chi-squared test. For intact enamel, SBS on varnished enamel at 24 h was significantly less than in the other groups. SBS recovered 7 days after varnishing. Varnish elimination after 24 h significantly increased the SBS. However, removal at 7 days did not modify SBS. SBS on demineralized enamel groups was significantly less than in intact enamel, except for demineralized enamel varnished and removed at 7 days. Demineralized enamel was associated with cohesive enamel fractures and intact enamel with cohesive fractures of the composite and adhesive fractures. SEM of varnish surfaces showed a homogenous layer scattered with amorphous precipitate. In conclusion, on intact enamel fluoride varnish had a negative effect on SBS at 24 h, which disappeared after 7 days. On demineralized enamel, varnish did not reduce SBS at either time. Polishing the varnished enamel surface showed a similar SBS to intact enamel after 7 days.

Detection of 2-dodecylcyclobutanone in radiation- sterilized chicken meat stored for several years

International Nuclear Information System (INIS)

Victoria, A.; Crone, J.; Hamilton, J.T.G.; Stevenson, M.H.

1992-01-01

Results are presented indicating a linear relationship between irradiation dose (10–60 kGy) and the quantity of 2-dodecylcyclobutanone produced in irradiated frozen (-46°C) chicken meat. 2-Dodecylcyclobutanone was found in chicken meat sterilized (at -40°C) by gamma and electron beam irradiation 12 years previously and used for toxicity clearance. After freeze-drying the irradiated chicken samples still contained 2-dodecylcyclobutanone indicating that it was present in the diets tested. The compound was not detected in chicken meat sterilized by thermal processing 13 years ago. In addition, there was evidence that 2-tetradecylcyclobutanone was also present in the irradiation sterilized samples

Physicochemical properties of radiation-sterilized honey alginate wound dressing for exudating wounds

International Nuclear Information System (INIS)

Asa, Anie Day DC.; De Guzman, Zenaida M.; Baldos, Davison T.; Asaad, Celia O.

2013-01-01

Honey is a well-known natural cure in promoting healing of wounds. Alginate, on the other hand, is a polysaccharide with pharmaceutical applications such as wound dressing and control release drugs. Calcium-alginate wound dressings have a gel-forming capability. in that, upon ion exchange between calcium ions in the dressing, and sodium ions in wound fluid, the dressing transforms into a gel. Cross-linked alginate gels can absorb would fluid, and also maintain a moist environment to the wound area. Combined with anti-microbial properties of honey and absorption and gelling properties of alginate, a honey alginate wound dressing is developed and irradiated for sterility. Its physicochemical properties are then analyzed. The honey-alginate wound dressing has lower pH (4.40±0.02) than alginate alone dressings (5.40±0.04) which is more favorable for wound healing. The dressing also has low moisture content (10.25±1.11%). Analysis of moisture vapour transmission rate shows a general increase with time for 48 hours. The wound dressing also has an absorbency of 19.00±1.80 g/100 cm 2 with a gel fraction of 18.44±0.63%. The rate of absorption analysis, meanwhile, shows a very rapid absorption rate upon exposure to wound fluid. After some time, a decrease in rate is observed which is accounted to the release of honey to the wound environment. For tensile strength, irradiation causes an effect in tensile strength in machine direction but is insignificant for cross machine direction. Physicochemical properties of the radiation-sterilized honey alginate wound dressing e.g. acidic pH, absorbency, moisture vapor permeability and absorption rate ascertain its characteristic as a good wound dressing for exudating wounds. Its low moisture content, meanwhile, allows for longer shelf-life of the developed product. (author)

Codling moth control by release of radiation-sterilized moths in a pome fruit orchard and observations of other pests

International Nuclear Information System (INIS)

Proverbs, M.D.; Newton, J.R.; Logan, D.M.; Brinton, F.E.

1975-01-01

Release of radiation-sterilized male and female Laspeyresia pomonella (L.) in a 40-ha pome fruit orchard from 1969-72 in the Similkameen Valley of British Columbia reduced the wild population of this pest to a very low level without causing serious problems in control of other apple and pear pests. Percent apples injured by codling moth larvae at harvest were 0.1 in 1968 (after 3 sprays of azinphosmethyl), and 0.05, 0.02, 0.007, and 0.001 from 1969-72

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.

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.

Mediterranean fruit fly: interference of oviposition by radiation-sterilized females in field cages

Energy Technology Data Exchange (ETDEWEB)

McInnis, D. O. [Tropical Fruit and Vegetable Research Lab. USDA-ARS, Honolulu, HI (United States); Wong, T. T.Y.

1990-07-01

In experiments between April and September 1984, the behaviour of nonirradiated and radiation-sterilized laboratory-adapted adults of the tephritid Ceratitis capitata was observed on apples hung on guava trees in outdoor cages in Hawaii. The numbers of nonirradiated females observed resting on fruit were reduced several times by the presence of irradiated females, either alone or with irradiated males, but not by irradiated males alone. Similarly, the number of nonirradiated females observed ovipositing and the duration of oviposition was reduced by the presence of irradiated females. In control cages (all nonirradiated flies), the duration of oviposition by females averaged 255.9±15.0 s on fruit, while most of nonirradiated and irradiated females in the mixed (treatment) cage averaged 157±19.8 s and 77.5±7.5 s on fruit, resp. Irradiated females behaved skittishly on fruit and frequently engaged in physical encounters with other flies.

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.)

Ar + NO microwave plasmas for Escherichia coli sterilization

International Nuclear Information System (INIS)

Hueso, Jose L; Rico, Victor J; Cotrino, Jose; Gonzalez-Elipe, Agustin R; Frias, Jose E

2008-01-01

Ar + NO microwave discharges are used for sterilization and the results are compared with additional experiments with Ar, O 2 and N 2 -O 2 plasma mixtures. The NO * 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 * and Ar * species) and UV radiation (from deactivation of NO * species) are responsible for the higher activity found for this plasma mixture. (fast track communication)

Electron beam sterilization of water discharged from sewage

International Nuclear Information System (INIS)

Miyata, Teijiro; Arai, Hidehiko; Tokunaga, Okihiro; Machi, Sueo; Kondo, Masaki; Minemura, Takashi; Nakao, Akio; Seike, Yasuhiko.

1989-01-01

At present, the water treated at city sewerages is discharged to rivers after the chlorine sterilization, but it was clarified recently that this chlorine treatment produces carcinogenic organic chlorine compounds, and residual chlorine exerts harmful effect to aquatics, therefore, it is desirable to develop the sterilization techniques substituting for chlorine treatment. Already many reports elucidated that irradiation is effective for the sterilization of the water discharged from sewerage. However, as the technical subject for putting radiation process in practical use, the treatment of large quantity was a problem. Recently by the progress of the technology of manufacturing electron accelerators, the equipment with large power output which can treat in large quantity was developed, and it has become applicable also to sewage treatment. Therefore, the authors examined the practicality of electron beam process as the substitute technology for chlorine sterilizaiton. In the case of using electron beam, though the power output of accelerators is large, the flight range of electron beam in water is short. The comparison of the sterilization effect of electron beam with that of Co-60 gamma ray, the effects of water depth, discharged water quality and water velocity on the sterilization effect and so on were experimentally examined. (K.I.)

Toxicity of methods of implant material sterilization on corneal endothelium

Energy Technology Data Exchange (ETDEWEB)

Singh, G.; Boehnke, Mv.; von Domarus, D.; Draeger, J.

1985-11-01

The toxicity of different procedures utilized for the sterilization of intraocular implant material was assessed on the endothelium of organ-cultured porcine corneas. Polymethylmethacrylate lenses sterilized by treatment with sodium hydroxide (NaOH), ethylene oxide, formaldehyde, and gamma radiation were added to a culture medium containing normal porcine corneas. Considering the viability of endothelial cells, appearance of intracellular degenerative vacuoles, and denudation of corneal Descemet's membrane as criterion for the evaluation of toxicity of different methods of sterilization, the NaOH-treated lenses were found to be the least toxic to porcine corneal endothelium. Phase-contrast microscopy and vital staining of the endothelium permitted direct viewing of the endothelium aiding in the assessment of toxicity.

RVNRL and radiation processing in Thailand

International Nuclear Information System (INIS)

Siri-Upathum, C.

2000-01-01

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)

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)

Investigation of the effect of gamma radiation on lincomycin

International Nuclear Information System (INIS)

Al-Zier, A; Al- Kassiri, H.; Al Aji, Z.

2001-01-01

Sterilization of materials used in medical applications is necessary. Since the use of ethylene oxide will be forbidden in the next future and other sterilization methods as wet, and dry hot sterilization are not suitable for sterilization of drugs, further methods are needed which do not cause a significant decrease in the physical and chemical drug properties. Radiation sterilization can help in many cases. So Gamma or electron radiations were used for sterilization of antibiotics in the solid state as mentioned in the literature. Some antibiotics are already exposed to gamma or electron beam irradiation, and showed significant radiation resistance for low doses, but even small amounts of degradation products are not desirable

Future growth in the gamma sterilization of disposable medical products (DMPs)

International Nuclear Information System (INIS)

Brinston, R.M.

1990-01-01

An estimated 361 million cubic feet (10 million cubic meters) of disposable medical products and related health care items are currently being sterilized around the world. Ethylene oxide gas is used to treat approximately 252 million cubic feet (7.1 million cubic meters), gamma radiation is used to sterilize approximately 99 million cubic feet (2.8 million cubic meters), and electron beam is used on approximately 10 million cubic feet (0.3 million cubic meters) of disposable medical products (DMPs). Market share for each of these terminal cold sterilization processes are 70%, 27%, and 3% respectively. There are a number of factors which are affecting the overall growth of the market. The most important factors are summarized. Balancing all of these factors, the pre-sterilized disposable products market is forecasted to grow on average of 5% per year. Gamma radiation is experiencing growth from both general market growth and the introduction of new products, as well as the conversion of product from ethylene oxide (EtO) to cobalt-60 sterilization. Electron beam usage while experiencing good growth in the early 1980s, is predicted to have a flat growth curve during the late 1980s, and then start to experience renewed growth in the mid to late 1990s as two or three new electron beam facilities are built. In the late 1990s other potentially competing technologies are expected to have an impact on the market place. (author)

Substantiation of 25 kGy (by use of VDmax25 method) as the sterilization dose

International Nuclear Information System (INIS)

2011-01-01

The International standards for radiation sterilization require evidence of the effectiveness of a minimum sterilization dose of 25 kGy but do not provide detailed guidance on how this evidence can be generated. Although many of the procedural elements in method VD m ax are similar to those of Method 1 of ANSI/AAMI/ISO 11137-2, there are differences that require elaboration. In this project, test procedure of VD m ax 2 5 method was established and then validated in Radiation Microbiology Laboratory (RML) test conditions. Beside, this method has been applied successfully for two years in order to reply the demand of the manufacturer firms as routine test service. In the near future, RML will be the only accredited laboratory in Turkey on 'validation of radiation sterilization' standard (ANSI/AAMI/ISO 11137-2: 2006) that consists of VD m ax 2 5 method

Adjustable sterile lead apron for radiation protection during angiography

Energy Technology Data Exchange (ETDEWEB)

Grollman, J.H. Jr.; 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 tilted in the longitudinal plane. Properly placed, the apron effectively reduces exposure due to scatter.

Temperature Effects on Free Radicals in Gamma-sterilized Beef

Science.gov (United States)

Pramanik, S. I.; Jahan, M. S.

1999-11-01

Gamma irradiation has become the method of choice for sterilizing frozen meat and their products to reduce levels of food-borne pathogens and to extend shelf life. In this report we have employed ESR technique for detection of free radicals in sterilized and non-sterilized dry beef without bone. We have also determined the heating effects on free radicals at temperatures 176^°C and 250^°C. Meat samples were dried in a food dehydrator at 60^°C and were packaged in dry N_2. They were then sterilized by γ-irradiation (2.5 MRad), ground into powder, and placed in ESR sample tubes. Non-sterilized powder samples were used as control. While all powder samples, sterilized or not, produced a broad single line in the ESR spectra with (Δ H_pp ~ 9 G) and g = 2.013, the radical concentration in the sterilized samples increased by a factor of five. Heat treatment at 176^°C produced similar radicals. But, when samples were heated 250^°C different radical species were formed which are characterized by narrow width (Δ H_pp ~ 6 G) and lower g-value (g =2.010). In contrast with previous work, where free radicals in chicken bones were reduced by heating [1], we observed an increase in concentration. Results of structural analyses of the radicals will be presented. Ref.[1]: Radiat. Phys. Chem., 49, 477-481, 1997. Work supported by Grants from the University of Memphis

Energy analysis in sterilization process of food

International Nuclear Information System (INIS)

Lee, Dong Sun; Pyun, Yu Ryang

1986-01-01

A procedure was developed for predicting energy consumption of batch type thermal processing of food. From mass and energy balance equations various energy usages or losses were estimated for steam sterilization of model food system in No.301-7 can (Φ74.1 x 113.0mm) at three different temperatures. Selected models were 5 % bentonite solution for conductive food and tap water for convective food. Total steam or energy consumption was higher at 110 deg C than at two other higher temperatures (121 deg C and 130 deg C). High energy consumption at low sterilization temperature was mainly due to high bleeding steam energy and convective and radiative heat losses. Thermal energy efficiency was also disscussed. (Author)

Gamma-ray sterilization of peat carriers for the production of legume seed inoculants (better production of soya bean)

International Nuclear Information System (INIS)

Vojinovic, Z.; Milicic, B.; Radak, B.

1983-01-01

In the present work the first Yugoslav experiments on the application of gamma radiation for the sterilization of peat in the production of inoculants for soya bean production are summarised and briefly discussed. A radiation dose of 50 kGy was used. The growth and survival of the soya bean nodule bacteria, Rhizobium japonicum, in the sterilized peat is shown. (U.K.)

Removal of different fractions of NOM foulants during demineralized water backwashing

KAUST Repository

Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Verliefde, Arne R. D.; Amy, Gary L.; Van Dijk, Johannis C.

2012-01-01

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

Design of convergent pierce electron gun of accelerator for radiation sterilization by the method of synthesis

International Nuclear Information System (INIS)

Kong Xiaoxiao; Li Quanfeng

2003-01-01

A synthesis technique for the preliminary design of convergent Pierce electron guns is introduced briefly which has a series of advantages over the traditional methods. A thermal cathode electron gun used in the accelerator for radiation sterilization with the synthesis method is redesigned, and the validity of this method is proved. Based on the preliminary design parameters given by the synthesis method, a simulating calculation program, EGUN, was used in the numerical figure design of the focusing electrode and the anode. The final results can meet the engineering requirement as the current being 1A, the normalized emittance being less than 4 mm·mrad, and the final current density showing uniformity

Biofilm extracellular polysaccharides degradation during starvation and enamel demineralization.

Directory of Open Access Journals (Sweden)

Bárbara Emanoele Costa Oliveira

Full Text Available This study was conducted to evaluate if extracellular polysaccharides (EPS are used by Streptococcus mutans (Sm biofilm during night starvation, contributing to enamel demineralization increasing occurred during daily sugar exposure. Sm biofilms were formed during 5 days on bovine enamel slabs of known surface hardness (SH. The biofilms were exposed to sucrose 10% or glucose + fructose 10.5% (carbohydrates that differ on EPS formation, 8x/day but were maintained in starvation during the night. Biofilm samples were harvested during two moments, on the end of the 4th day and in the morning of the 5th day, conditions of sugar abundance and starvation, respectively. The slabs were also collected to evaluate the percentage of surface hardness loss (%SHL. The biofilms were analyzed for EPS soluble and insoluble and intracellular polysaccharides (IPS, viable bacteria (CFU, biofilm architecture and biomass. pH, calcium and acid concentration were determined in the culture medium. The data were analyzed by two-way ANOVA followed by Tukey's test or Student's t-test. The effect of the factor carbohydrate treatment for polysaccharide analysis was significant (p 0.05. Larger amounts of soluble and insoluble EPS and IPS were formed in the sucrose group when compared to glucose + fructose group (p < 0.05, but they were not metabolized during starvation time (S-EPS, p = 0.93; I-EPS, p = 0.11; and IPS = 0.96. Greater enamel %SHL was also found for the sucrose group (p < 0.05 but the demineralization did not increase during starvation (p = 0.09. In conclusion, the findings suggest that EPS metabolization by S. mutans during night starvation do not contribute to increase enamel demineralization occurred during the daily abundance of sugar.

Radiosterilization and other sterilization methods of medical equipment on Kilmer's conference, Brussels, 12-16 June 1993

International Nuclear Information System (INIS)

Zagorski, Z.P.

1993-01-01

The Johnson and Johnson Co. organized the scientific conference devoted to different aspects and methods of sterilization of medical equipment and materials. A condensed review of the main problems discussed during the conference has been done. Attention has been paid especially on: actual problems with primary infections control, problems of sterilization in pharmacy, hazards problems, investigations and control methods and radiation sterilization. 2 figs

Sterile neutrino

International Nuclear Information System (INIS)

Anon.

2007-01-01

Paper deals with the information on the occurrence of the fields of the sterile neutrinos (the righthanded ones) mixed with the normal neutrinos (the lefthanded ones). Both the Max Plank Radioastronomy Institute and the Los Angeles University assumes that the occurrence of the keV mass sterile neutrinos may explain the dark matter nature, the fast rotation of the observed pulsars and the reionization processes. The issues associated with the possibility to record the sterile neutrinos were analyzed in the course of the Sterile Neutrinos in Astrophysics and Cosmology Workshop (Crans Montana, March 2006 [ru

Studies on the ecology of insects sterilized artificially (gamma radiation), 8. Experimental analysis of the sexual competitiveness between normal males of the oriental fruit fly and males sterilized by the /sup 137/Cs gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Kiyoku, M; Tsukuda, R [Okayama Univ. (Japan). Faculty of Agriculture

1974-09-01

Gamma-ray irradiation of 7 KR from /sup 137/Cs on the oriental fruit fly pupae two days before emerging did not significantly reduce the percentage of emergence and longevity of adult flies. However, highly sterile adults (more than 98.9%) were found in those combinations, S..gamma.. x N/sup -/, N..gamma.. x S/sup -/ and S..gamma.. x S/sup -/. The result of observation of sperm activity in spermathecae of females mated with sterilized males showed that the sterility is caused by dominant lethalities. The sexual competitiveness between S..gamma.. and N..gamma.. has been examined in experiments of S..gamma.. x N..gamma.. x N/sup -/. (1) The data suggest that the sterility percentage concerning with egg hatchability is proportional to the rate of sterilized males replaced for normal males when that is expressed with a multiple of the ratio of normal males to normal females. Seven such straight lines thus obtained made us possible to find the theoretical expectation of sterility percentage. (2) Relationship between the percent egg hatch observed (y), or that estimated theoretically (Y), and logarithm of ratio, S..gamma../N..gamma.. (x) was showed to be two straight regression equations, y=18.413-11.952 (x - 1.295) and Y=11.890-15.462 (x - 1.295). Ratio of regression coefficients of the equations was 0.772. (3) Correlations between the sterility percentage and ratio, S..gamma../N..gamma.., showed in three convex curves under three degrees of competitiveness (0.265, 0.576 and 1.001). When both the values of S..gamma../N..gamma.. in the mating experiments and the sterility percentages are given, it is possible to obtain degrees of competitiveness using the curves.

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.

Sterile insect technique and radiation in insect control

International Nuclear Information System (INIS)

1982-01-01

Out of 39 papers and 6 summaries of the poster presentations published in this proceeding series, 23 respectively fall within the INIS subject scope. Four main topics were covered: a review of the sterile insect technique against various insect pests; its application to tsetse flies in eradication programmes; quality control of mass-reared insects for release; and the development of genetic approaches to insect mass rearing and control. Other topics emphasized integrated pest management, computer models and radioisotope labelling

Effects of gamma radiation (60Co) on the main physical and chemical properties of health care packaging and their compounds paper and multilayer plastic film, used for health products sterilization

International Nuclear Information System (INIS)

Porto, Karina Meschini Batista Geribello

2013-01-01

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)

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)

Ph-activated nano-amorphous calcium phosphate-based cement to reduce dental enamel demineralization.

Science.gov (United States)

Melo, Mary A S; Weir, Michael D; Passos, Vanara F; Powers, Michael; Xu, Hockin H K

2017-12-01

Enamel demineralization is destructive, esthetically compromised, and costly complications for orthodontic patients. Nano-sized amorphous calcium phosphate (NACP) has been explored to address this challenge. The 20% NACP-loaded ortho-cement notably exhibited favorable behavior on reducing demineralization of enamel around brackets in a caries model designed to simulate the carious attack. The 20% NACP-loaded ortho-cement markedly promotes higher calcium and phosphate release at a low pH, and the mineral loss was almost two fold lower and carious lesion depth decreased the by 1/3. This novel approach is promising co-adjuvant route for prevention of dental caries dissemination in millions of patients under orthodontic treatment.

The possibility of gamma ray sterilization by using ITU TRIGA Mark II reactor

International Nuclear Information System (INIS)

Bilge, A.N.; Tugrul, B.; Yavuz, H.

1988-01-01

Gamma rays are one of the effective method for sterilization which is preferred for a long time. Generally Co-60 radioisotope sources betatrons or accelerators are used for the sterilization. In this work, it was aimed to find the possibilities of the sterilization by gamma rays obtained in ITU TRIGA Mark-II radial tube. Radiation dosages are measured in the radial tube and several medical products are irradiated. Irradiation is arranged according to the desired dosages. Irradiated sterilized goods (mainly medical products) tested and checked at the Governmental Medical Health Center and results compared with literature. It can be seen that this kind of irradiation is a good tool for sterilization. Unfortunately, because of the stability of the radial tube and impracticality of the system it is rather difficult to compete with industrial system using Co-60 and accelerators. Nevertheless, this type of irradiation is also applicable for the purpose of the sterilization by using ITU TRIGA Mark II. (author)

The hardness and chemical changes in demineralized primary dentin treated by fluoride and glass ionomer cement

Directory of Open Access Journals (Sweden)

Gisele Fernandes DIAS

Full Text Available Abstract Background Fluoride plays an important role in the control of dental caries. Aim To evaluate the chemical exchange between restoration of glass ionomer cement of high viscosity (GIC and primary dentin with application of sodium fluoride (NaF 2% through changes in hardness from uptake of calcium, phosphate and fluoride. Material and method Class I cavities were prepared in 40 sound primary molars, and the sample was divided into two groups (n=20 according to dentin condition: sound (1 and demineralized (2. Sub-groups (n=10 were formed to investigate the isolated action of the GIC or the association with NaF (F. This in vitro study examined the chemical exchange under two conditions, sound and demineralized dentin (pH cycling, to simulate the occurrence of mineral loss for the caries lesion. G1 and G2 received GIC restoration only; groups G1F and G2F received NaF before GIC restoration. The specimens were prepared for Knoop hardness test and micro-Raman spectroscopy. A two-way ANOVA test (α = 0.05 was used for statistical analysis. Micro-Raman data were qualitatively described. Result Increased hardness was observed in all the sites of direct contact with GIC in sound and demineralized dentin for all groups (p0.05. In the evaluation of micro-Raman, direct contact between GIC and dentin for sound and demineralized dentin resulted in increased peaks of phosphate. Conclusion The exchange between GIC and demineralized dentin may induce changes of mechanical properties of the substrate, and uptake of mineral ions (phosphate occurs without the influence of NaF.

Radiation chemistry

International Nuclear Information System (INIS)

Rodgers, F.; Rodgers, M.A.

1987-01-01

The contents of this book include: Interaction of ionizing radiation with matter; Primary products in radiation chemistry; Theoretical aspects of radiation chemistry; Theories of the solvated electron; The radiation chemistry of gases; Radiation chemistry of colloidal aggregates; Radiation chemistry of the alkali halides; Radiation chemistry of polymers; Radiation chemistry of biopolymers; Radiation processing and sterilization; and Compound index

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).

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.

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

International Nuclear Information System (INIS)

Park, Dong Hyun; Park, Young Ho; Kim, Kyung Sook; Park, Jeong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Hun Kuk; Choi, Yong Suk; Hwang, Eui Hwan

2009-01-01

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.

Assessing the environmental impacts of using demineralized coal for electricity generation

DEFF Research Database (Denmark)

Ryberg, Morten; Owsianiak, Mikolaj; Laurent, Alexis

2014-01-01

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...... in alkaline and acidic solution to dissolve and remove the ash. This process is well-studied on lab scale but has only to a small extent been tried on a full scale. This assessment is conducted as an aid for further developing thetechnology, allowing for early identification of environmental impacts...... cycle perspective, to assessthe environmental impacts from removing ash in coal, and assess how this affects the combustion in terms of higher thermal efficiency. We assess 260 different data points applying alkali-acid leaching or acidleaching and assess how the treatment and subsequent energy...

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.

Process variation in electron beam sterilization

International Nuclear Information System (INIS)

Beck, Jeffrey A.

2012-01-01

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 Guide for Process Control in Radiation Sterilization. The study supports the following conclusions for electron beam processes: 1.ANOVA is a more effective tool for evaluating the equivalency of absorbed doses than methods suggested in . 2.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. 3.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.

Effect of the sterilization process on physical and mechanical properties of the bonacryl bone cement

International Nuclear Information System (INIS)

Morejon, L.; Delgado, J.A.; Aguero, L.; Rapado, M.; Ginebra, M.P.; Gil, F.J.; Mendizabal, E.

2008-01-01

The use of bone cements of poly(methyl methacrylate) (PMMA) to fix artificial prosthesis to the human body is a habitual method in orthopedic surgery. The hip and the knee joints have a very complex biomechanics and support high loads, for these reasons, acrylic bone cements have to comply with international standards in order to secure the biofuncionality and durability of the implant. In this work we report the effect of sterilization by ethylene oxide or gamma radiation on the BONACRYL Cuban cement. We determined how sterilization methods affect the molecular weight of the polymer as well as its quasi-static mechanical properties. The results demonstrated that the gamma radiation modifies the molecular weight of the PMMA although the compression and bending strength were not affected by the sterilization process applied. (authors)

Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization

International Nuclear Information System (INIS)

Kato, Ilka Tiemy

2004-01-01

The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm 2 , 3.7 J/cm 2 , 5.6 J/cm 2 , 7.4 J/cm 2 and 9.3 J/cm 2 ) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

Radiations: tool for insect pest management

International Nuclear Information System (INIS)

Swami, Kailash Kumar; Kiradoo, M.M.; Srivastava, Meera

2012-01-01

The discovery that X-rays or gamma radiation could cause sufficient genetic damage to insect reproductive systems to induce sterility resulted from work conducted by H.J. Muller starting in the 1920s. The sterilizing effect of radiation was noted by scientists of the US Department of Agriculture who had been seeking a method to sterilize insects for many years. These scientists had theorized that if large numbers of the target insect species were reared, sterilized, and released into the field, the sterile insects would mate with the wild insects. These mating would result in no offspring and thus a decline in the population would be obtained. They calculated that if sufficient numbers of sterile insects were released, reproductive rate for the wild population would rapidly decline and reach zero. In simple language, birth control of insects. Radiation sterilization was the answer. In a SIT operation, radiation is used to sexually sterilize insects. Since the SIT is species specific, the selection the insect pest or group of pests on which to work is of primary importance. The Joint Division of the IAEA Food and Agriculture Organization (FAO) has been involved in the use of isotopes and radiation in insect control since 1964. Isotopes are used as tags or markers, for instance, of chemical molecules, insects, or plants. For example, with these tags one can follow the fate of insecticides within insects and the environment; the incorporation of nutrients into the insect; and the movements of insects under field conditions. They also can plants on which insects feed so that the quantity of consumed food can be measured and directly correlated with plant resistance. They can be used as well to follow parasites and predators of insects - for example, their movements, numbers, and ability to help control insect pests. Radiations therefore have come as a novel tool to combat insect pest problem and in future could be very helpful in various other ways, of be it be cost

Biomedical applications of ionizing radiation

International Nuclear Information System (INIS)

Rosiak, J.M.; Pietrzak, M.

1997-01-01

Application of ionizing radiation for sterilization of medical devices, hygienization of cosmetics products as well as formation of biomaterials have been discussed. The advantages of radiation sterilization over the conventional methods have been indicated. The properties of modern biomaterials, hydrogels as well as some ways of their formation and modification under action of ionizing radiation were presented. Some commercial biomaterials of this kind produced in accordance with original Polish methods by means of radiation technique have been pointed out. (author)

Thermal analysis of used and radiation treated polycarbonate (L-MW) biomaterial

International Nuclear Information System (INIS)

Jayabalan, M.; Sreenivasan, K.; Nair, P.D.; Jalajamani, K.V.

1988-01-01

γ-radiation treatment of radiation sterilized polycarbonate biomaterials has been carried out to ensure efficient disposal by incineration. Low molecular weight polycarbonate sterilized with 2.5 Mrad dose of γ-radiation was further treated with different doses of γ-radiation. The radiation-treated samples were subjected to thermogravimetry. The sterilized sample and the 7.5 Mrad-treated sample showed similar properties. These samples do not leave any residue during thermal decomposition. (author). 5 refs., 3 tables

Effects of solvents on the early stage stiffening rate of demineralized dentin matrix.

Science.gov (United States)

Garcia, Fernanda C P; Otsuki, Masayuki; Pashley, David H; Tay, Franklin R; Carvalho, Ricardo M

2005-05-01

To monitor the stiffening rate of demineralized dentin matrix at the early stages after exposure to different neat solvents. Dentin beams approximately 0.8x0.7x8.0 mm were obtained from human third molars. After covering their ends with resin composite, the middle exposed length of 4.0mm (gauge-length) was demineralized in 0.5 M EDTA (pH 7.0) for 7 days. The specimens were gripped by a testing machine, pre-loaded to 10 g and cyclically stressed in tension to 5% strain, for 30 repeated cycles (total 20 min) at 0.6 mm/min while immersed in water (control). Then, water was replaced by either 100% acetone, methanol, ethanol, propanol, HEMA or air and the specimens subjected to the same cyclic protocol. The maximum apparent modulus of elasticity (E(Max)) was calculated for every cycle, plotted as a function of time and subjected to regression analysis. Stiffening rate was calculated as changes in E (min). Regression analysis examined the relationship between E and time for each solvent. Data were analyzed by one-way ANOVA and Student-Newman-Keuls test at alpha=0.05. Regression analysis showed that E increased significantly with time in all water-free solvents (R2=0.8-0.99). Stiffening rate was higher for acetone (0.9 MPa/min) and ethanol (0.8 MPa/min), intermediate for air (0.7 MPa/min), methanol (0.6 MPa/min) and propanol (0.5 MPa/min), lower for HEMA (0.2 MPa/min) and practically none for water (0.07 MPa/min) with prate of demineralized dentin matrix is both time and solvent-dependent. The ability of solvents to promptly stiffen the demineralized dentin matrix may be important in maintaining the resin-infiltrated matrix expanded during the solvent evaporation stage of resin bonding.

Optimal reduction of humus in demineralization

International Nuclear Information System (INIS)

Persson, F.

1989-04-01

To have an optimal reduction of organic substance and colloids in a demineralization plant the following ought to be observed. * At least two anion exchangers should be in series. The firs one being either a weak macroporous polystyrene anion exchanger or a weak polyacrylic anion exchanger. A third anion exchanger in series improves the reduction only marginally. * The leakage of organic substance and colloids increases rapidly at the same time or before the leakage of anions. The anion exchangers in a plant should therefore have a higher capacity than the cation exchangers. If the anion exchangers do not have a higher capacity than the cation exchangers only 90-95 % of the capacity shall be used. * The filtration rates have normally no influence of the reduction organic of substance. Sometime a low filtration rate gives a better reduction of colloids. * The content of organic substance in the water to the plants has a great effect on the capacity for ions. At high content of organic substance (20 mg KMnO 4 ) the capacity for ions can be reduced with 30-40 %. * Different technics for regenerations does not seem to have any influence on the reduction of organic substances and colloids. Neither age of the anion exchangers nor washing with solutions of sodium chloride seems to have any influence on the reduction. Age and organic contamination have mainly an influence on the capacity per regeneration. At all demineralization plants some organic substances and colloids leak through the plant, the quantities depending on the colloids. To remove this organic substances and colloids the ion exchangers must be completed with for instance flocculation or reverse osmosis. (L.E.)

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

Sterility and property of norecoverable medical items from non-woven fabric

International Nuclear Information System (INIS)

Tashmetov, M.Yu.; Ismatov, N.B.; Makhkamov, Sh.M.; Saidov, R.P.; Abdulmanov, R.G.

2014-01-01

Full text: The purpose of present study is determination of the sterilization dose of surgery coat and sheet from spanbond-meltbond-spanbond material with minimum deviation of initial strength value. All seams of this surgery coat are sewed by dual insertion and soldered by ultrasonic solder for strenthening of the protective-barrier properties. It is established that after the radiation sterilization of disposable surgery coat at dose 20 kGy the breaking load of material lengthwise and width corresponds to permissible standards

The Effect of Two Different Sterilization Methods on The Surface Topography and Microbial Contamination of Different Types of Endodontic Files

International Nuclear Information System (INIS)

Yousri, H.R.M.

2014-01-01

Sterilization is an integral part of the dental field. Sterilization should be used for instruments, surgical gloves and other items that come in direct contact with the blood stream or normally sterile tissues. Because sterilization is a process, not a single event, all components must be carried out correctly for sterilization to occur. To be effective, sterilization requires time, contact, temperature and with steam sterilization, high pressure. The effectiveness of any method of sterilization is also dependent upon four other factors: The type of microorganism present, the number of microorganisms present, the amount and type of organic material that protects the microorganisms and the number of cracks and crevices on an instrument that might harbor microorganisms. The most commonly used and standard methods of sterilization is the steam under pressure method using the autoclaves. However, it's not free from drawbacks; where it is not suitable for the heat sensitive equipment's such as the plastics, rubber. Also repeated autoclaving can cause pitting and dulling of cutting edges of instruments which might affect their clinical performance. Another alternative method of sterilization is by gamma rays which have been introduced for the sterilization of heat sensitive equipment's. Therefore conducting a study to investigate the effect of repeated sterilization cycles by either steam under pressure or gamma radiation on the surface topography of root canal enlarging instruments was thought to be valuable. The null hypothesis tested is that there is no difference in the effect of repeated sterilization by either steam under pressure or gamma radiation on the surface topography of root canal enlarging instruments

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...

Radiation as a microbiological contamination control of drugs, cosmetics and medical devices

International Nuclear Information System (INIS)

Ishizeki, Chuichi

1985-01-01

This paper deals with current status of radiation sterilization or disinfection of drugs, cosmetics, their materials, and medical devices, and with quality control as a tool for securing microbiological safety, especially current status of sterilization tests. Ointment containing tetracyclin, steroid hormones, gelatin, and enzymes are presented as drug samples to be irradiated, and explanations for radiation sterilization of these drugs are provided. An outline of the application of radiation in cosmetics and medical devices is given. Issues are also provided from the viewpoint of safey and effectiveness of radiation sterilization. (Namekawa, K.)

Hospital waste sterilization: a technical and economic comparison between radiation and microwave treatments

International Nuclear Information System (INIS)

Tata, A.; Beone, F.

1995-01-01

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 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, plastic, 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 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. (author)

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

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=

Studies of the ecology of insects sterilized artificially (gamma radiation), 12

International Nuclear Information System (INIS)

Kiyoku, Masao

1978-01-01

Experimental results of artificially sterilized insects studied with gamma rays from 1968 to 1977 are reviewed and summarized from a statistical and population ecological point of view. The discussion is based on experimental results of callosobruchus chinensis, spodoptera litura and dacus dorsalis. A model of population fluctuations was constructed theoretically by experimental results concerning the effect of insecticides, heats or gamma rays upon oviposition, sex ratio and survival rate during growing period of insects. The theoretical population fluctuation brought about by insecticides or heats became wide, the population density was high and remarkable peak appeared frequently in succeeding generations. On the other hand, that induced by gamma rays was narrow and the population density maintained a low level during several generations. Such a theoretical fluctuation was demonstrated by experiments dealt with the experimental population of callosobruchus chinensis. Sexual competitiveness between sterilized males and normal ones in the mixed population was discussed theoretically. The relationship between log (S/N) and hatchability of egg laid ought to show a straight line. The difference between the theoretical log (S/N)-hatchability regression equation and the experimental one was examined. Growth of population containing some sterile males was studied by means of theoretical calculation of population numbers from generation to generation. The rate of increase of the strilized populations was found to be remarkably smaller than that of normal ones. (Iwakiri, K.)

A study on the spreading ability of radiation-sterilized male moth of bombyx mandarin in field

International Nuclear Information System (INIS)

Yang Rongxin; Xia Darong; Gu Weiping; Zhang Yanjun

1998-01-01

The mulberry wild silkworm (MWS), belong to the Bombycidae of Lepidoptera, is serious pest of sericulture. The female moth of MWS is sterile and the male moth is sub-sterile when they were treated with 250 Gy 60 Co γ-ray (dose rate: 1.05 Gy/min), and their filial generations was sterile. The spreading ability of male moth of MWS in field and retrieving the marked MWS male moth with the trapping method was studied. The trapping solution was composed of sugar, vinegar, wine and alive female moth. The retrieving rate of MWS male moth amounted to 12.6%∼13.5% of released moth in field. The spreading range in 24 hours for sterile MWS male moth reached to 700 m, and 90.8% of MWS male moth was in an area of 5 m radius from the releasing centre. It is concluded that thirty releasing centres per hectare are needed to make the irradiated sterilized insects spread for controlling the MWS in field

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.

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.

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.

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.

Comparison of retention and demineralization inhibition potential of adhesive banding cements in primary teeth.

Science.gov (United States)

Prabhakar, A R; Mahantesh, T; Ahuja, Vipin

2010-01-01

The purpose of this study was to evaluate the efficacy of banding cements in terms of retentive capability and demineralization inhibition potential. We included 48 non-carious primary mandibular second molar teeth. Preformed stainless steel bands were adapted onto the teeth. All teeth were randomly assigned to four groups: Group I (Adaptation of bands without cementation), Group II (Cementation of bands using conventional Glass Ionomer Cement), Group III (Cementation of bands using Resin-modified Glass Ionomer Cement), Group IV (Cementation of bands using Resin cement), and placed in artificial saliva. Each day, specimens were taken from artificial saliva and suspended in an artificial caries solution for 35 minutes, every 8 hours. At the end of 3 months, retention of bands was estimated using an Instron Universal Testing Machine. The mode of failure was recorded and specimens were sectioned and examined under polarized microscope for demineralized lesions. The mean retention value was highest with resin cement, followed by RMGIC, GIC, and Control group respectively. The RMGIC group showed more favorable modes of failures. All the experimental groups showed significant demineralization inhibition potential. RMGIC is the preferable banding cement and can be used effectively to cement bands in primary dentition.

Role of fluoridated carbamide peroxide whitening gel in the remineralization of demineralized enamel: An in vitro study.

Science.gov (United States)

Bollineni, Swetha; Janga, Ravi Kumar; Venugopal, L; Reddy, Indukuri Ravikishore; Babu, P Ravisekhar; Kumar, Sunil S

2014-05-01

The use of self-administered carbamide peroxide bleaching gels has become increasingly popular for whitening of discolored vital teeth. Studies have reported that its use may induce increased levels of sensitivity and surface roughness of the tooth due to demineralization. This study evaluates the effect of fluoride addition to the bleaching agent - its remineralizing capacity and alterations in the whitening properties. Twenty-four extracted lower third molar teeth, with the pretreatment shade determined, were taken up in the study. Each tooth was sectioned into four and labeled as groups A, B, C, and D. The tooth quadrants in group A-C were demineralized; groups A and B were treated with 10% carbamide peroxide gel (group-A without fluoride and group-B with 0.463% fluoride addition) (no further treatment was carried out for group c) group-D remained as the control. The post-treatment shade was determined. The tooth samples were sectioned (approximately 200 μm) for evaluation under a light microscope. The depth of demineralization was analyzed at five different equidistant points. Statistical analysis was carried out with t-tests, accepting ≤0.05 as significant. Addition of fluoride caused remineralization of demineralized enamel. The tooth whitening system showed that the remineralization properties did not affect the whitening properties.

Effect of sterilization procedures on properties of plasma polymers relevant to biomedical applications

International Nuclear Information System (INIS)

Artemenko, A.; Kylián, O.; Choukourov, A.; Gordeev, I.; Petr, M.; Vandrovcová, M.; Polonskyi, O.; Bačáková, L.; Slavinska, D.; Biederman, H.

2012-01-01

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: ► Effect of common sterilization methods on three kinds of plasma polymers is studied. ► Physical, chemical and bioresponsive properties of plasma polymers are analyzed. ► Changes induced by sterilization depend strongly on type of the plasma polymer.

Cytological studies of sterility in male progeny of mutagen-exposed male parents

International Nuclear Information System (INIS)

Cacheiro, N.L.A.; Cornett, C.V.

1987-01-01

Genetic male sterility results primarily from certain types of balanced reciprocal translocations, and, more rarely, from certain numerical sex-chromosome anomalies. Sterile male offspring sired following exposure of male meiotic or postmeiotic stages to radiation or chemical mutagens are not uncommon and are predominantly carriers of balanced translocations. The chromosome breakpoints of these translocations are generally located near the ends of autosomes or anywhere in the sex chromosomes. Sterile offspring from mutagen-treated spermatogonial stem cells, on the other hand, are not only rare but most of them have no readily detectable chromosomal anomalies. Those that have are either carriers of balanced translocations, or are sex-chromosome trisomics or mosaics (XYY, XXY, XY//XYY, XO//XY, etc.). The nature of the exchange in spermatogonia-derived sterile translocations is not clear and awaits detailed study. In addition, the data base is not yet sufficient for determining the role of induced nondisjunction in the production of genetic male sterility. Accordingly, they have an ongoing project that attempts to study associations between the nature of genetic fertility impairments and the detailed chromosomal genotype, and between chromosomal causes of sterility and the nature of mutagenic treatments that produce them

Overview of Twenty Years of Radiation and Tissue Banking Activity in Argentina

International Nuclear Information System (INIS)

Kairiyama, E.

2015-01-01

Radiation sterilization of human tissues in Argentina was a consequence of health care products sterilization by gamma radiation. Radiation technology was implemented in 1970 when the first multipurpose gamma facility was built at the Ezeiza Atomic Centre of CNEA. Organ and tissue transplantation is a well established effective therapy that saves lives and significantly improves the quality of life. Ionizing radiation is used for sterilization in order to provide clinically safe tissue for therapeutic purposes of implantation in every patient in need. Argentina radiation and tissue banking activity started in 1993 with the establishment of two tissue banks using radiation under the IAEA programme of technical cooperation, a skin bank and a bone one. Additionally to this start, other tissue banks have adopted tissue sterilization by irradiation. The compatible tissues sterilized with this methodology are mainly skin (frozen, glycerolized), bone (lyophilized, frozen), and amniotic membrane (glycerolized, frozen, dehydrated). The donation and transplant of human organ, tissue and cells is regulated and coordinated by the National Institute Unique Central Coordinator of Ablation and Implant (INCUCAI). In regards to radiation and nuclear safety, physical protection and nuclear non-proliferation issues are regulated and contorted by the Nuclear Regulatory Authority (ARN). Eight tissue banks use gamma radiation for sterilization of human tissues (6 musculoskeletal, 1 skin and 1 amniotic membrane). Argentina has participated actively in several IAEA projects regarding radiation and tissue banking program, and it has been selected by the IAEA to host the Regional Training Centre for the Latin American region. The following activities were implemented: regional training courses in Buenos Aires, face to face (five) and virtual (four) modalities; collaboration on several materials related to tissue banking and radiation sterilization of tissue allograft, codes of practice for

Radiation sterilization and volatile matter used for medical devices touching to blood

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Akitada; Sato, Michio; Igarashi, Yoshiaki; Yagami, Takeshi [National Inst. of Health Sciences, Tokyo (Japan); Yoshii, Fumio

1998-02-01

In this study, it was conducted by using chemical analysis and cell toxic test if any volatile matter actually on radiation, if any matter could be detected when its generating, if it stayed to a safe volume range, and so forth. Objective materials of this study focus the elements used for medical devices always touching blood having large effect on human bodies. In this fiscal year, because of many cases of sterilization after filling water and necessary gas-liquid equilibrium for quantitative method using a head space when actually using the materials for dialyzer, irradiation was conducted after filling water into the material, comparison of gas volume and evaluation of safety with those of conventional experiments. As a result, by {gamma}-ray irradiation, various matters are formed, and some volatile matters less than some ng level in present volume could be detected. However, from a standpoint of safety data and forming volume of the cell toxic test results, there were no matter anxious to safety. Furthermore, the present dialyzer and others are washed before using chemically, and its safety seems to be fully held. (G.K.)

Radiation sterilization and volatile matter used for medical devices touching to blood

International Nuclear Information System (INIS)

Nakamura, Akitada; Sato, Michio; Igarashi, Yoshiaki; Yagami, Takeshi; Yoshii, Fumio

1998-01-01

In this study, it was conducted by using chemical analysis and cell toxic test if any volatile matter actually on radiation, if any matter could be detected when its generating, if it stayed to a safe volume range, and so forth. Objective materials of this study focus the elements used for medical devices always touching blood having large effect on human bodies. In this fiscal year, because of many cases of sterilization after filling water and necessary gas-liquid equilibrium for quantitative method using a head space when actually using the materials for dialyzer, irradiation was conducted after filling water into the material, comparison of gas volume and evaluation of safety with those of conventional experiments. As a result, by γ-ray irradiation, various matters are formed, and some volatile matters less than some ng level in present volume could be detected. However, from a standpoint of safety data and forming volume of the cell toxic test results, there were no matter anxious to safety. Furthermore, the present dialyzer and others are washed before using chemically, and its safety seems to be fully held. (G.K.)

NF EN ISO 11137-1, July 2006. Sterilization of health care products - Irradiation - Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices

International Nuclear Information System (INIS)

2006-01-01

This part of the ISO 11137 standard specifies requirements for the development, validation and routine control of a radiation sterilization process for medical devices. Although the scope of this part of the ISO 11137 standard is limited to medical devices, it specifies requirements and provides guidance that may be applicable to other products and equipment. This part of the international standard covers radiation processes employing irradiators using the radionuclide 60 Co or 137 Cs, a beam from an electron generator or a beam from an X-ray generator. This part of the international standard does not: - specify requirements for development, validation and routine control of a process for inactivating the causative agents of spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease; - detail specified requirements for designating a medical device as sterile; - specify a quality management system for the control of all stages of production of medical devices; - specify requirements for occupational safety associated with the design and operation of irradiation facilities; - specify requirements for the sterilization of used or reprocessed devices

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.

Evaluation of demineralized bone and bone transplants in vitro and in vivo with cone beam computed tomography imaging.

Science.gov (United States)

Draenert, F G; Gebhart, F; Berthold, M; Gosau, M; Wagner, W

2010-07-01

The objective of this study was to determine the ability of two flat panel cone beam CT (CBCT) devices to identify demineralized bone and bone transplants in vivo and in vitro. Datasets from patients with autologous bone grafts (n = 9, KaVo 3DeXam (KaVo, Biberach, Germany); n = 38, Accuitomo 40 (Morita, Osaka, Japan)) were retrospectively evaluated. Demineralized and non-demineralized porcine cancellous bone blocks were examined with the two CBCT devices. A SawBone skull (Pacific Research Laboratories, Vashon, WA) was used as a positioning tool for the bone blocks. Descriptive evaluation and image quality assessment were conducted on the KaVo 3DeXam data (voxel size 0.3 mm) using the OsiriX viewer as well as on the Morita Accuitomo data (voxel size 0.25 mm) using proprietary viewer software. Both in vivo and in vitro, the descriptive analysis of the images of the two devices showed well-visualized bone transplants with clearly defined cancellous bones and well-defined single bone trabeculae in all cross-sections. In vitro, demineralized samples showed lower radiographic opacity but no significant loss of quality compared with fresh bone (P = 0.070). Single cancellous bone trabeculae were significantly better visualized with the Morita 3D Accuitomo device than with the KaVo 3DeXam device (P = 0.038). Both the KaVo 3DeXam and Morita 3D Accuitomo devices produce good-quality images of cancellous bones in in vivo remodelling as well as after in vitro demineralization.

Sterilization of fruit flies (Diptera: Tephritidae) with X-rays for sterile insect technique programs; Esterilizacao de moscas-das-frutas (Diptera: Tephritidae) com raios-X para programas de tecnica do inseto esteril

Energy Technology Data Exchange (ETDEWEB)

Mastrangelo, Thiago de Araujo

2009-07-01

Recent fear of acts of terrorism provoked an increase of delays and denials in the shipment of radioisotopes. This truly represented a menace to sterile insect production projects around the world. In order to validate the use of a new kind of low-energy Xray irradiator, a series of radiobiological studies on Ceratitis capitata (tsl-VIENNA 8 strain) (Wied., 1824) (Diptera: Tephritidae) and an Argentinean strain of Anastrepha fraterculus (Wied., 1830) (Diptera: Tephritidae) were carried out, also comparing biological effectiveness between X-rays and traditional {gamma} radiation from {sup 60}Co. Pupae 48- 24 h before adult emergence of C. capitata males and both sexes of A. fraterculus were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Doses that induce 50, 90 and 99% of sterility were estimated and the hypothesis of Parallelism for the Probit equations was tested. Doses of 82.7 Gy of X-rays and 128.2 Gy of {gamma} rays (thus, a RBE{approx}1.5) induced 99% sterility on medfly males. The fertility of A. fraterculus fertile females crossed with 41 Gy of X-rays and 62.7 Gy of {gamma} rays decreased in 99% comparing with the control group (RBE{approx}1.5). 99% sterility of A. fraterculus irradiated females was achieved with 60-80 Gy (RBE{approx}0.7). The standard quality control parameters of fecundity, adult emergence, fliers and survival were not significantly affected by the two types of radiation (RBE{approx}1) either for medfly or A. fraterculus (p>0.01), being averages in conformity with the values required by FAO/IAEA/USDA. Only fecundity of irradiated A. fraterculus females was severely reduced with increasing doses and no egg was laid at 70 Gy of both radiations. There were no significant differences between X-rays and {gamma} rays regarding mating indices (RSI for medfly, RII, ISI, MRPI and FRPI for A. fraterculus) (p>0.05), what indicated more random matings for fertile and sterile insects. The results demonstrated that no

Change of various enzyme activities of koji and sterilization of koiji by γ-radiation

International Nuclear Information System (INIS)

Iwano, Kimio; Mikami, Shigeaki; Oishi, Atsushi; Shiinoki, Satoshi

1987-01-01

Sterilization and changes of various enzyme activities of koji by gamma irradiation were investigated. A dose of 1 Mrad gamma irradiation was effective for the sterilization of koji. Various enzymes of koji were inactivated about 10-30% by the irradiation, while no influence was observed for shochu fermentation. There seemed to be no influence for qualities of sake and shochu by the irradiation. (author)

Mortality and sterility induced in Piophila casei by x-ray and neutron irradiation

International Nuclear Information System (INIS)

Sacchi, L.; Gasperi, G.; Grigolo, A.; Caprotti, M.; Pinelli, T.; Altieri, S.

1977-01-01

Different doses of neutrons and X-rays were given to 5-day-old pupae of Piophila casei L. (Diptera, Piophilidae), just before their emergence. The mortality and sterility induced by the different types of radiation were measured. Neutrons are more effective than X-rays in provoking lethal lesions in somatic cells. Females are more resistant than males to the sterilizing action of neutrons, the relative biological efficiency of neutrons being 6 and 3.5, respectively

Mortality and sterility induced in Piophila casei by x-ray and neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Sacchi, L; Gasperi, G [Pavia Univ. (Italy). Ist. di Zoologia; Grigolo, A [Bari Univ. (Italy). Ist. di Zoologia e Anatomia Comparata; Caprotti, M [Pavia Univ. (Italy). Fondazio Clinica del Lavoro. Reparto di Radiologia; Pinelli, T; Altieri, S [Pavia Univ. (Italy). Istituto di Fisica Nucleare

1977-01-01

Different doses of neutrons and X-rays were given to 5-day-old pupae of Piophila casei L. (Diptera, Piophilidae), just before their emergence. The mortality and sterility induced by the different types of radiation were measured. Neutrons are more effective than X-rays in provoking lethal lesions in somatic cells. Females are more resistant than males to the sterilizing action of neutrons, the relative biological efficiency of neutrons being 6 and 3.5, respectively.

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

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.

Steam sterilization and automatic dispensing of [18F]fludeoxyglucose (FDG) for injection

International Nuclear Information System (INIS)

Karwath, Pascal; Sartor, Johannes; Gries, Wolfgang; Wodarski, Christine; Dittmar, Claus; Biersack, Hans J.; Guhlke, Stefan

2005-01-01

For the purpose of implementing steam sterilization of 2-[ 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 (∼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

Assessment of differences between X and γ rays in order to validate a new generation of irradiators for insect sterilization

International Nuclear Information System (INIS)

Mastrangelo, Thiago; Walder, Julio M.M.; Parker, Andrew G.; Jessup, Andrew; Orozco-Davila, Dina; Islam, Amirul; Dammalage, Thilakasiri; Pereira, Rui

2009-01-01

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 γ radiation from 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 γ 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 γ radiation regarding mating indices. The RBE did not differ significantly between the tested X and γ radiation, and X-rays are as biologically effective for SIT purposes as γ rays are. This work confirms the suitability of this new generation of X-ray irradiators for pest control programs in UN Member States. (author)

Peracetic Acid: A Practical Agent for Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds

Science.gov (United States)

Yoganarasimha, Suyog; Trahan, William R.; Best, Al M.; Bowlin, Gary L.; Kitten, Todd O.; Moon, Peter C.

2014-01-01

Advanced biomaterials and sophisticated processing technologies aim at fabricating tissue-engineering scaffolds that can predictably interact within a biological environment at the cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed before clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam, and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone, a low melting polymer, and employing spores of Bacillus atrophaeus as biological indicators, we compared ethylene oxide, autoclaving and 80% ethanol to a known chemical sterilant, peracetic acid (PAA), for their ability to sterilize as well as their effects on scaffold properties. PAA diluted in 20% ethanol to 1000 ppm or above sterilized electrospun scaffolds in 15 min at room temperature while maintaining nano-architecture and mechanical properties. Scaffolds treated with PAA at 5000 ppm were rendered hydrophilic, with contact angles reduced to 0°. Therefore, PAA can provide economical, rapid, and effective sterilization of heat-sensitive polymeric electrospun scaffolds that are used in tissue engineering. PMID:24341350