International Nuclear Information System (INIS)

The synthetic process of polyethylene cation exchange capillary via radiation grafting polystyrene by simultaneous irradiation with "6"0Co #gamma#-ray source and sulfonation with concentrated H_2SO_4 was studied. The effects of dose, dose rate, monomer concentration, solvents, temperature and crosslinking agents on the graft copolymerization of styrene with polyethylene capillary were illustrated. The relationship between the radiation grafting conditions and the properties of ion-exchange capillary were examined. A polyethylene cation exchange capillary with I.D. 0.8 mm, length 20 m, exchange capacity 0.7 Meq/g 60% capacity in 10 s (flow rate 20 ml/min) was prepared. No significant loss of copacity was found from this ion-exchange capillary after 200 adsorption/regeneration cycles.

International Nuclear Information System (INIS)

Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85"0C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to #gamma#-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel so that the extent of homo polymer could be reduced to be less than 1.6% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmations of graft copolymerization and saponification reactions were made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the same total dose on the extent of grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction ...

International Nuclear Information System (INIS)

The nature of radicals in wood irradiated in vacuum was studied by ESR method. The decay rate of radicals changes in three temperature ranges. Long-lived radicals are very stable at 298"0K, at which the wood-plastics composite has often been studied. The number of radicals formed by irradiations shows fairly good agreement with the total number of radicals in each isolated wood component. The graft copolymerization of MMA to irradiated wood was also studied by means of ESR, and it was found that PMMA propagating radicals are formed in irradiated wood. These radicals are probably formed by the result of graft copolymerization of MMA of wood. (auth.).

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Conditions for radiation induced grafting with butyl acrylate dispersed in water emulsion onto chrome-tanned pig skins have been worked out for #gamma#-rays and electron beam irradiations. The highest yield of grafting was observed at monomer concentration approximately 25% (w/w), dose equal to 25 kGy and dose rate not exceeding 10 MGy/h. At these conditions the yield of grafting attained a value approximately 25% and content of homopolymer in the leather amounted to 6%. The efficiency of monomer to polymer conversion decreases when the concentration of monomer in emulsion and dose rate increases. Yield of homopolymer is independent of the dose rate. An explanation of the observed relations has been proposed. The physical and used properties of grafted leathers were tested. Radiation processed leathers were found superior to samples finished by traditional ...

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Two local repair procedures, one without (9) and the other with (14) a bulbocavernosus muscle graft were performed on 20 patients with a radiation induced rectovaginal fistula. Four patients had two procedures successively. The initial success rate of both procedures was 7/9 and 14/14 respectively. Though the initial result of the bulbocavernosus graft was obviously better, in many of the local repair procedures, subclinical radiation damage progressed, resulting in recurrence of rectovaginal fistula (5), rectovesical fistula (4), pararectal abscess (2) etc. After a mean follow up of around 10 years, the success rate of fistula repair decreased to 5/9 and 13/14 and only 2/9 and 6/14 finally remained without a colostomy. A local repair operation should be restricted to carefully selected cases. The musculus gracilis is proposed as a better vascular graft. If the general condition of ...

Science.gov (United States)

Graft copolymers of methyl methacrylate and biodegradable, biocompatible bacterial poly([R]-3-hydroxybutyrate) (PHB) blocks were synthesized and evaluated as possible constituents in acrylic bone cements for use in orthopaedic applications. The copolymers were produced by conventional free radical copolymerization and incorporated in one commercially available acrylic bone cement brand, Antibiotic Simplex (AKZ). Cements with formulations containing 6.7 and 13.5 wt % of PMMA-graft-PHB were prepared. The morphology of the graft copolymer particles was suggested to influence the ability of the modified cement to be processed. Formulations containing more than about 20 wt % of the graft copolymer resulted in cement doughs that, both after first preparation and several hours later, were either sandy or soft spongy in texture and, thus, would be unacceptable for use in orthopaedic ...

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Short communication. 5 refs., 2 figs.

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Short communications only.

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The circulation in microvascularized rib grafts has been compared with that in conventional rib grafts and in those augmented by a direct vascular bundle implantation into the bone grafts. A new experimental model has been designed to correlate vascular perfusion, bone scan patterns, tetracycline labeling, and histological findings in these bone grafts. Posterior microvascularized rib grafts were found to have a circulatory pattern identical to that of the normal rib. Failed microvascularized rib grafts were revascularized more slowly than conventional rib grafts. Vascular bundles implanted into rib grafts remained patent and increased the rate of revascularization. The stripping or preservation of periosteum had no observable effects on the rate or pattern of conventional rib graft ...

UK PubMed Central (United Kingdom)

Compliance mismatch is a significant challenge to long-term patency in small-diameter bypass grafts because it causes intimal hyperplasia and ultimately graft occlusion. Current engineered grafts...Full Text Available

UK PubMed Central (United Kingdom)

Background: Contamination of autologous grafts unfortunately occurs in plastic surgery, but the literature provides no guidance for management of such incidents. Methods: American...Full Text Available

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Genomic instability can be produced by ionising radiation, so-called radiation-induced genomic instability, and chemical mutagens. Radiation-induced genomic instability occurs in both germinal and somatic cells and also in the offspring of irradiated individuals, and it is characterised by genetic changes including chromosomal rearrangements. The majority of studies of trans-generational, radiation-induced genomic instability have been described in the male germ line, whereas the authors who have chosen the female as a model are scarce. The aim of this work is to find out the radiation-induced effects in the foetal offspring of X-ray-treated female rats and, at the same time, the possible impact of this radiation-induced genomic instability on the action of a chemical mutagen. In order to achieve both goals, the quantity and quality of chromosomal damage were analysed. In order to ...

International Nuclear Information System (INIS)

Eight patients with double-velour Dacron aorto-femoral grafts implanted for 2-60 months were studied. Indium-111-labelled platelets were found to have a shortened mean platelet lifespan (MPLS) of 138 +- 32 hours compared with the normal platelet lifespan of 224 +- 23 hours. Labelled platelets accumulated on all grafts, irrespective of graft age, to a maximum of 1,80 +- 0,83% of whole body radioactivity; thereafter graft radio-activity decreased. This suggests that platelets on the graft are in dynamic equilibrium with those in the circulation. Platelets may be lost from the graft by embolization or radioactivity may be released because of platelet lysis. Although MPLS may depend on the age and surface area of the graft, concomitant arterial disease probably also contributes to the shortened MPLS.

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The objective of this study was to evaluate the role of collagen membrane and Bio-Oss coverage in healing of an onlay graft to the mandible. Twelve adult sheep each received an onlay bone graft (experiment 1), bone graft+Bio-Gide (experiment 2), and bone graft+Bio-Oss/Bio-Gide (experiment 3) on the lateral surface of the mandible. The animals were euthanized at 4, 8, 12 or 16 weeks after surgery, and findings were analysed by routine microscopy and immunohistochemistry for proliferation (Ki67) and apoptotic (Caspase-3) markers. Grafts were fully incorporated in all specimens. Pronounced resorption was observed in experiment 1. Minimal loss of graft volume was seen in experiment 2 specimens without membrane displacement. A remarkable increase in the augmented region of the mandible was obse...

UK PubMed Central (United Kingdom)

γ-Radiation-induced tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated...Full Text Available

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The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proximal tibia tunnels. One limb was implanted with HAp-coated PET graft, and the contralateral limb was implanted with non-HAp-coated PET graft as control. The rabbits were randomly sacrificed at four and eight?weeks after surgery. The loads to failure of the experimental group at eight?weeks were significantly higher than those of the control group (p?=?0.0057). Histologically, application of HAp coating induced new bone formation between graft and bone at eight?weeks compared with the controls. Rea...

UK PubMed Central (United Kingdom)

A new strategy is presented for the synthesis of graft copolymers using only the ring-opening metathesis polymerization (ROMP). From a ROMP-derived main chain, pendant maleimide functional groups...Full Text Available

UK PubMed Central (United Kingdom)

Aneurysms of saphenous vein grafts are rare but can result in complications such as myocardial infarction or death. Percutaneous treatment has included a variety of approaches, including covered stents....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In the synthesis of the peptidyl-polymer corresponding to the sequence (57-100) of the ..beta.. chain of human hemoglobin on Teflon with radiationally grafted polystyrene a comparative study was made of different methods of fragment condensation. It was shown that the most effective methods are azide condensation and condensation with the use of complex F.

International Nuclear Information System (INIS)

Japanese (Sep 1974). Japan Kudo, Susumu . Kansai Medical School,

UK PubMed Central (United Kingdom)

To capitalize on the response of tumor cells to ionizing radiation, we developed a controlled-release nanoparticle drug delivery system using a targeting peptide that recognizes a radiation-induced...Full Text Available

UK PubMed Central (United Kingdom)

IntroductionIrradiation of normal, non-malignant bone during cancer therapy can lead to atrophy and increased risk of fracture at several skeletal sites, particularly...Full Text Available

UK PubMed Central (United Kingdom)

IntroductionRadiotherapy outcomes might be further improved by a greater understanding of the individual variations in normal tissue reactions that determine tolerance. Most published...Full Text Available

Science.gov (United States)

... Regine, Nader Hanna, Michael C. Garofalo, Austin Doyle, Susanne Arnold, Ritesh Kataria, Jacqueline Sims, Ming Tan, Mohammed Mohiuddin. ( ... ...

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Survival curves were constructed from dose-incidence curves for apoptosis in the crypts of mouse small intestine, using the number of apoptotic cells after high doses (N{sub M}) as maximum cell population size. The mean lethal doses (D{sub 0}) for the dose range 0-0.5 Gy were calculated for each time of day. A circadian rhythm in both D{sub 0} and N{sub M} values was detected, indicating that both the number and sensitivity of radiation-induced apoptosis were changing throughout the day. (author).

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The resistance of six tropical hardwoods to fungal degradation by two wild-type strains of Phanerochaete chrysosporium Burdsall was investigated using vermiculite burial and wood-block weight loss techniques. Radiation-induced wood-polymer composites (WPC), based on two hardwoods Ramin and Rubberwood with methyl methacrylate, were prepared, and samples were also exposed to the wood-rotting fungus. A significant improvement in resistance to fungal decay was observed in the WPC. Scanning-electron micrographs of the two woods and their composites after fungal degradation are presented and discussed.

International Nuclear Information System (INIS)

Polytetrafluoroethylene was obtained by radiation induced polymerization of tetrafluoroethylene in acetone at 195 K. An average diameter of the products was very small compared with commercial one; it was about 0.3 micro-meters. The yield was reached to 100% with a dose of 4 kGy. The crystallinity of the products is decreasing with increasing dose. The products become amorphous, for higher irradiation doses. It was found that PTFE obtained by irradiation of TFE in acetone at 195 K has branching structure. This was demonstrated by means of "1"9F MAS NMR. (Author)

International Nuclear Information System (INIS)

The electronic structure of the clusters [V_3Si_4]"1"2"-, [Nb_3Sn_4]"1"2"-[Mo_3Ge_4]"1"5"- in crystalline V_3Si, Nb_3Sn, Mo_3Ge compounds is calculated by the Extended Hueckel method. The influence of different types of radiation induced defects on the density of states at the Fermi level (the anti-site defects, the displacement of atoms in linear chains, the vacancy-interstitial type defects) is considered. (author).

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The prospective study includes 25 patients without pathology of the femoral head for the evaluation of the normal femoral head perfusion. In addition 34 patients with femoral head necrosis underwent i.a. DSA preoperatively before pedicled pelvic bone grafting. 15 patients after pelvic bone graft operation and 7 patients with medial femoral head fracture were also examined via superselective DSA. In cases with femoral head necrosis a rarefaction or interruption of the rami nutricii proximales, or an occlusion of the medial circumflex femoral artery were observed. Patients with medial femoral neck fracture showed an interruption of the rami nutricii proximales of the femoral head. Postoperative DSA - after pedicled pelvic bone graft - revealed a regular arterial graft perfusion in 82%. (orig.).

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No abstract prepared.

British Library Electronic Table of Contents (United Kingdom)

The influence of chemical and solvent extraction compatibilising techniques on the mechanical properties of poly-lactic acid (PLA) and MaterBi-polyester (PEM) based bio-composites are compared. First, fibres were chemically grafted with two fatty chains: stearic anhydride and octadecylisocyanate. Grafted fibres were characterised by FTIR and elemental analyses. Contact angle measurements show the hydrophobisation of the fibres in spite of very low surface grafting. Extracted and non-grafted fibres were prepared to be used as references. PEM and PLA-based composites with 30% w/w were prepared by compression moulding. Their mechanical properties were studied. It was found that chemical and solvent treatment of the fibres improved the reinforcement effect in the case of a PEM matrix and the Y...

International Nuclear Information System (INIS)

Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and 5-aminobenzamide that inhibit the expression ...

British Library Electronic Table of Contents (United Kingdom)

Radiofrequency electromagnetic fields (EMF) are harmful to public health, but the certain anti-irradiation mechanism is not clear yet. The present study was performed to investigate the possible protective effects of green tea polyphenols against electromagnetic radiation-induced injury in the cultured rat cortical neurons. In this study, green tea polyphenols were used in the cultured cortical neurons exposed to 1800?MHz EMFs by the mobile phone. We found that the mobile phone irradiation for 24?h induced marked neuronal cell death in the MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) and TUNEL (TdT mediated biotin-dUTP nicked-end labeling) assay, and protective effects of green tea polyphenols on the injured cortical neurons were demonstrated by testing the content ...

International Nuclear Information System (INIS)

The radiation induced reactions in LDPE in the presence of phenolic type antioxidants have been studied. It was shown that various antioxidants can influence the polyethylene network formation and the radical yield in different ways. The dependence of network structure on absorbed doses was determined by gel analysis, hot-set test and extraction of antioxidants for samples irradiated with accelerated electrons. It was found that the antioxidants eluted from polyethylene in higher percentage influence polymer crosslinking to a smaller degree. The ESR studies of #gamma#-irradiated blends of polyethylene with antioxidant indicate the presence of alkyl and phenoxyl radicals. The role of antioxidant molecules on radiation induced reactions in polyethylene-antioxidant systems is considered. The correlation between the network structure and the type of additive in polyethylene is also discussed. (author).

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The objective of this study was to compare contrast-enhanced magnetic resonance angiography (CE MRA) and multislice computed tomographic angiography (MS CTA) in the follow-up of thoracic stent-graft placement. The CE MRA and MS CTA were performed following nitinol stent-graft treatment due to thoracic aneurysm (n=4), intramural bleeding (n=2) and type-B aortic dissection (n=5). Corresponding evaluation of arterial-phase imaging characteristics focused on the stent-graft morphology and leakage assessment. Stent-graft and aneurysm extensions were comparable between both techniques. Complete exclusion (aneurysm, n=4; dissection, n=2) was assessed with high confidence with CE MRA and MS CTA. Incomplete exclusion (intramural bleeding, n=2; dissection, n=3) was assigned to lower confidence scores on CE MRA compared with MS CTA. On CE MRA the stent-graft lumen demonstrated an inhomogeneous ...

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As an alternative to surgery, endovascular therapy with stent grafts has become the second main treatment option for infrarenal abdominal aortic aneurysms. Unlike surgery, endovascular treatment with stent grafts is also applicable in patients unfit for open repair. Despite current improvements in endovascular repair devices, significant anatomic barriers still exclude this technique for a large number of patients. Computed tomography, magnetic resonance imaging, and ultrasound are essential for diagnostics, preintervention planning, and postintervention follow-up of abdominal aneurysms treated with stent grafts. This review covers etiology, pathology, and diagnostic aspects. Materials and methods for endovascular treatment of abdominal aortic aneurysms are presented in detail, and clinical results and complications are discussed. (orig.) [German] Die endovaskulaere Therapie des infrarenalen Bauchaortenaneurysmas hat sich ...

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Infections of aortoarterial prostheses are serious, difficult to detect, and difficult to treat. Scintigraphy with indium-111 labeled autologous leukocytes is an accurate noninvasive method of assessing the presence and extent of such an infection. In three cases of aorto-arterial bypass graft infections, the leukocyte study was successful in establishing the diagnosis and in assessing the extent of infection. Other noninvasive diagnostic techniques are useful, but all have serious limitations. The leukocyte study alone appears to be free of likely sources of error.

British Library Electronic Table of Contents (United Kingdom)

Platelet-rich plasma (PRP) is a platelet concentrate that has widely been used to accelerate the healing of soft and hard tissues. The preparation of PRP has been described by several authors. Preparation protocols vary from system to system, depending on the concentration of different integrating proteins. The objective of this article is to describe the principal use of PRP mixed with fat grafts in aesthetic plastic surgery.

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Acrylonitrile electropolymerization (in an aprotic and anhydrous medium) has been used as a way to build thin, homogeneous and covering polyacrylonitrile layers grafted on the surface of usual metals and specially on copper-based shape memory alloy: Cu-Zn-Al. The results of the study first confirm the possibility of grafting thin and covering polyacrylonitrile layers on Cu-Zn-Al surface. The morphology of the films however is influenced by the geometry of the polycristalline structure of the alloy and its superficial defects. Samples obtained after grafting polyacrylonitrile films were submitted to corrosion tests based on Electrochemical Impedance Spectroscopy (EIS) measurements in a NaCl/H{sub 2}O medium. Results show that some post-treatments of the grafted films are necessary to improve their protective role, while preserving the strong interfacial bondings. Actually, thermal and mechanical cycling ...

International Nuclear Information System (INIS)

The effect on an oscillator moving in a medium produced by that part of the radiative force which does not perform work but creates and angular moment is considered. It is shown that the radiative torque turns the dipole toward the axis along which it is moving. Near the axis of motion the dipole executes small oscilltions. The frequency of the oscillations is determined. This effect leads to spontaneous alignment of the dipole moments on moving through the medium. The feasibility of observing the effect experimentally is discussed.

International Nuclear Information System (INIS)

Radiation hardening and radiation-induced chromium (Cr) depletion were related to intergranular stress corrosion cracking (IGSCC) response among various stainless steels (SS). Available data on neutron-irradiated materials were analyzed and correlations developed between fluence, yield strength, grain-boundary Cr concentration, and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 neutrons/cm"2 to 2.5 x 10"2"1 neutrons/cm"2) for IGSCC were documented. Variability often was consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence for most heats, suggesting a possible role for radiation-induced hardening (and microstructure) on cracking. However, isolated heats revealed a wide range of yield strengths (450 MPa to 800 MPa) necessary to promote IGSCC which could not be explained by strength effects alone. ...

International Nuclear Information System (INIS)

Epidemiological studies will not solve the shape of the dose effect curve for stochastic effects in the low dose range. Unicellular processes are necessary for the primary processes so that no threshold dose exists. This is evident for somatic and genetic mutations. Not clearly solved is this question for the complex carcinogenesis. These processes develop with manifold interacting molecular and cellular steps. (orig.).

International Nuclear Information System (INIS)

Post-irradiation annealing was used to help identify the role of radiation-induced segregation (RIS) in irradiation-assisted stress corrosion cracking (IASCC) by preferentially removing dislocation loop damage from proton-irradiated austenitic stainless steels while leaving the RIS of major and minor alloying elements largely unchanged. The goal of this study is to better understand the underlying mechanisms of IASCC. Simulations of post-irradiation annealing of RIS and dislocation loop microstructure predicted that dislocation loops would be removed preferentially over RIS due to both thermodynamic and kinetic considerations. To verify the simulation predictions, a series of post-irradiation annealing experiments were performed. Both a high purity 304L (HP-304L) and a commercial purity 304 (CP-304) stainless steel alloy were irradiated with 3.2 MeV protons at 360 deg. C to doses of 1.0 and 2.5 dpa. Following irradiation, post-irradiation anneals were performed at ...

UK PubMed Central (United Kingdom)

The three mammalian transforming growth factor (TGF)-β isoforms (TGF-β1, TGF-β2, and TGF-β3) differ in their putative roles in radiation-induced fibrosis in intestine...Full Text Available

International Nuclear Information System (INIS)

The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author).

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We have presented evidence that the functional thyroid follicles (follicular units, FU) which are formed in grafts of monodispersed rat thyroid cells, and hence the thyroid tumors which later develop in such grafts, are clonal in origin. Recent studies have been designed to investigate: whether cell number-dependent inhibition of promotion-progression is mediated by remote hormonal feed-back, local cell-cell interactions, or both; the cell population kinetics of the clonogen subpopulation during goitrogenesis and goiter involution; and the effect of prolonged exposure to high levels of TSH (thyrotropin) on the capacity of the clonogens to give rise to functional FU. The results indicate that local cell-cell interactions play an important role in the cell number-dependent suppression of neoplastic promotion-progression. They also show that if sufficient thyroid cells are grafted, the thyroid-pituitary axis can be ...

British Library Electronic Table of Contents (United Kingdom)

Sinus lifting and reconstruction of localized alveolar defects are often required after closure of a large oroantral fistula (OAF) to allow for subsequent implant installation. This study describes a combined surgical technique that involves sinus lifting, bony closure, and reconstruction of the alveolar defect at the site of an OAF. The sinus membrane was reconstructed as a continuous layer by combining the residual sinus membrane with a rotated part of oral mucosa around the OAF. Autogenous bone from the chin and/or ramus was grafted into the prepared sinus space and alveolar defect, and the graft was covered by a buccal advancement flap. This technique was used to treat 8 patients who had large OAFs in the posterior maxillary region. The treatment was successful in all cases, and the te...

UK PubMed Central (United Kingdom)

Successful implementation of bone marrow transplantation for hematopoietic reconstitution is limited by the lack of suitably HLA-matched donors and by the occurrence of graft-versus-host disease that...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

In this work, coals of various ranks were dissolved in an acid melange. With the use of IR spectroscopy, it was found that the mechanism of coal dissolution consists in the grafting of polar groups to the peripheral benzene rings of graphite-like systems.

British Library Electronic Table of Contents (United Kingdom)

This prospective study describes and evaluates a surgical approach for 3D reconstruction of the posterior maxilla with autogenous mandibular bone in 16 patients (mean age 51 years). Bone blocks were harvested from the mandible and used as lateral or vertical block grafts (onlay); they were also partially milled and used for sinus elevation (inlay). In 4 cases, anorganic bovine bone was added at the periphery of the blocks. 4 months after grafting, implants were placed in a second operation and loaded after 12 weeks. Lateral and vertical augmentations were measured immediately after grafting and at re-entry for implant placement. Mean lateral augmentation performed was 5.5mm, reduced to 4.3mm (p<0.01) after 4 months' healing. Mean vertical augmentation was 3.2mm, reduced to 2.1mm (p<0.01) a...

UK PubMed Central (United Kingdom)

Tendon reconstruction using grafts often results in adhesions that limit joint flexion. These adhesions are precipitated by inflammation, fibrosis, and paucity of tendon differentiation signals...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract Objectives: The purpose of this study was to evaluate the osseointegration of the dental implants placed into the mandible augmented with different techniques in pigs. Material and methods: Four adult domestic pigs were used. Horizontal augmentation of the mandible was performed in animals by using vascularized femur flap (VFF), non-vascularized femur graft (NVFG) and monocortical mandibular block graft (MG). After 5 months of healing 10 dental implants were placed into each augmented site. The pigs were sacrificed after 3 months of healing. Undecalcified sections were prepared for histomorphometric analysis. Results: Mean bone-implant contact (BIC) values for implants placed into MG, NVFG and VFF were 57.38 11.97%, 76.5 7.88%, 76.53 8.15%, respectively. The BIC values of NVFG and...

UK PubMed Central (United Kingdom)

PurposeThe aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmented sinus using Osteon, a bone graft material, and to assess the height...Full Text Available

UK PubMed Central (United Kingdom)

Nitric oxide (NO)-based therapies effectively inhibit neointimal hyperplasia in animal models of arterial injury and bypass grafting, but are not available clinically. We created a simple, effective,...Full Text Available

Science.gov (United States)

A 67-year-old man presented with gastrointestinal bleeding resulting from a fistula between the aortic stump and the fourth part of the duodenum 14 months after an axillobifemoral bypass, graft excision, and aortic stump closure for aortic graft infection. The patient initially refused any attempt at definitive surgical treatment so coil embolization of the aortic stump was performed via a brachial approach. Coil embolization may be a useful adjunct in the management of such difficult problems. This approach may buy time and allow careful planning of a definitive treatment or may serve as a palliative procedure in inoperable patients. PMID:15947052

International Nuclear Information System (INIS)

The effect of additives on the grafting of a monomer, butylmethacrylate (BA), into simul (a soft wood) has been studied using "6"0Co source at 3 Mrad. The enhancement of polymer loading (grafting) by the addition of minute amounts (1%) of oligomers and of polyfunctional monomers into simul + BA system has been further increased in the presence of acid and urea. The synergistic polymer loading yields by acid addition cause substantial decrease of tensile strength values of wood-plastic composite; but urea increases both polymer loading and tensile strength values synergistically in these systems. (author).

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Results are presented of trials in W. Germany involving Populus tremula X P. tremuloides. In a nursery in late August - early September 1971, some 1300 buds from 38 selected 3-yr-old hybrid aspen seedlings were grafted into T-slits at nodes 10-20 cm above root' collars of 1 and a half yr-old hybrid aspen stock (products of controlled crossings, and in some cases of similar parentage to the transplanted buds). In spring 1972, each stock (from which its own buds were removed) was cut back to a 'peg' 15-20 cm above the level of the graft; the 'peg' was later used to support the new shoot developed from the transplanted bud. By Sept. 1972, 33% of grafts were successful, the success rate being significantly different (3-67%) within clones; average height of scion shoots ranged from 79 to 375 cm (no significant difference between clones). In spring 1973, some 190 ...

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Homologous and heterologous arterial segments were implanted in Fisher rats subcutaneously for the purpose of examining the antibody titer of the recipients' serum after implantation by means of the immune-adherence hemagglutination method. The antibody titer after implantation both of homologous and heterologous grafts decreased to 1/8 by 2.0 million (M) rads irradiation of high voltage cathode rays. The results suggested that high voltage cathode ray irradiation was not enough for heterologous graft to suppress its tissue reaction. Homografts taken from dogs 3 or 6 hours after sacrifice were irradiated with 2.0 M rads and transplanted in canine carotid artery using the technic of end-to-end anastomosis. Angiograms 6 months after operation revealed excellent patency rate in all the grafts of 28 dogs. furthermore, findings of the grafts from 1 week to 5 years after operation on scanning and ...

International Nuclear Information System (INIS)

In this paper the structural and functional changes of gamma irradiated bovine hemoglobin are presented. Aqueous solutions/1%/of HbO_2 were irradiated in air with doses ranging from 1 to 4 Mrad. Isoelectric focusing indicated change of the charge of irradiated hemoglobin. The isoelectric point of hemoglobin was displaced towards more acid values with increasing doses, up from 1 Mrad. Fingerprint analysis and peptide column chromatography of irradiated hemoglobin demonstrated disturbances increasing with the dose. These changes were confirmed by amino acid analysis which showed that Cys, Met, Trp, His, Pro and Tyr residues were destroyed or modified following irradiation. At doses exceeding 1 Mrad the irradiated solutions of hemoglobin showed a decrease of heme-heme interaction and an increase of affinity for oxygen. Differences observed in oxygen-dissociation curves seem to be correlated with the radiation induced destruction of amino acid ...

British Library Electronic Table of Contents (United Kingdom)

Purpose Radiation-induced heart disease (RIHD) is a severe side effect of thoracic radiotherapy. This study examined the effects of pentoxifylline (PTX) and a-tocopherol on cardiac injury in a rat model of RIHD. Methods and Materials Male Sprague-Dawley rats received fractionated local heart irradiation with a daily dose of 9 Gy for 5 days and were observed for 6 months after irradiation. Rats were treated with a combination of PTX, 100 mg/kg/day, and a-tocopherol (20 IU/kg/day) and received these compounds either from 1 week before until 6 months after irradiation or starting 3 months after irradiation, a time point at which histopathologic changes become apparent in our model of RIHD. Results Radiation-induced increases in left ventricular diastolic pressure (in mm Hg: 35 +- 6 after sham...

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We have been investigating radiation-induced neoplastic transformants of C3H 10T1/2 mouse fibroblasts for evidence of heritable changes. C3H 10T1/2 cells were treated with 8 Gy X rays. After approximately 8 weeks of culture, type II/III foci were isolated from the monolayer using cloning rings. Cell lines developed from these foci, and clones established from these cell lines, were examined for DNA content. The isolated focus-derived populations and derived clones often display aneuploidy and/or polyploidization. In one instance a clone (derived from a single cell) displayed multiple polyploidies. During passage the ploidy of many of the anomalous populations gradually reverted to the ploidy of the non-neoplastically transformed state. The morphological features associated with the neoplastic transformation event were nevertheless retained. The results demonstrate that exposure to radiation can induce, in association with morphological neoplastic transformation, a ...

Science.gov (United States)

Ionizing radiation is a standard treatment for various human solid tumors. However, several clinical studies showed that a significant proportion of patients undergoing radiotherapy for hepatocellular carcinoma (HCC) develop intrahepatic and extrahepatic metastasis. Understanding of radiation-induced cancer cell invasiveness and behavior is essential and of great important for developing suitable treatment strategies to contain cancer spread. Therefore, in this study we evaluated the effectiveness of using swept source optical coherence tomography (SS-OCT) to monitor the enhancement of HCC cell invasiveness by radiation. SS-OCT images were acquired and recorded to obtain three-dimensional data sets per four hours in 48 hours after irradiating HepG2 cells with 7.5 Gy. The cell migration behavior in three-dimensional tissue models was quantified from images of radiation-induced and sham-irradiated cells.

International Nuclear Information System (INIS)

The thermal properties of five types of radiation-induced wood-polymer composites based on a tropical hardwood, rubberwood (Hevea braziliensis), was studied by oxygen index measurement, differential thermal analysis (DTA) and thermogravimetry (TG). The DTA and TG curves of composites were different from those of rubberwood, which can be attributed to the presence of the incorporated polymers. Of the five composites, the one impregnated with bis(2-chloroethyl)vinyl phosphonate reduced the initial temperature of decomposition, increased the peak temperatures of exothermic reactions, and increased the char yield. Comparison with physical blends of rubberwood and the corresponding polymer provided some evidence of chemical interaction of wood and polymer in some of the composites. (author).

Energy Technology Data Exchange (ETDEWEB)

In future experiments the readout electronics for pixel detectors is required to be resistant to a very high radiation level. In this paper we report on irradiation tests performed on several preFPIX2 prototype pixel readout chips for the BTeV experiment exposed to a 200 MeV proton beam. The prototype chips have been implemented in commercial 0.25 {micro}m CMOS processes following radiation tolerant design rules. The results show that this ASIC design tolerates a large total radiation dose, and that radiation induced Single Event Effects occur at a manageable level.

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A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45({plus minus}5)% and 90({plus minus}5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

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Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a {sup 60}Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used.

International Nuclear Information System (INIS)

Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used. (author)

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This short survey focuses on the main radiation-induced base lesions that have been identified within cellular DNA. For this purpose, sensitive assays that are aimed at measuring a few modifications per 10{sup 7} normal bases were set-up. In that respect high performance liquid chromatography - tandem mass spectrometry (CLHP-MS/MS) was found to be able to single out the formation of 9 oxidized nucleosides and two modified nucleo-bases out of the 70 oxidative base lesions that have been identified in model systems. As a striking result, it was found that in the DNA of {gamma}-irradiated human monocytes, the formamide-pyrimidine derivative of guanine is produced in a higher yield than the ubiquitous 8-oxo-7,8-dihydro-guanine damage, both arising from the same radical precursor. However, relatively high doses of ionizing radiation (> 20 Gy) have to be applied in order to detect an increase in the level of the damage. This is due to the low efficiency for both ...

International Nuclear Information System (INIS)

The process of mouse skin tumor formation is subdivided into three operational stages. These stages include initiation, promotion and progression. Ionizing radiation has been found to be a weak initiating agent in the production of malignant squamous cell carcinomas, a complete carcinogen and an agent effective in causing tumor progression. Four skin tumor histologies have been seen with ionizing radiation: benign papillomas, squamous (SCC) and basal (BCC) cell carcinomas and fibrosarcomas. Distinct non-ras transforming genes have been detected in radiation initiated SCCs. A benign papilloma cell line (308) was used as a model system to study ionizing radiation induced progression. A variant 308 cell line (308 10 Gy 5) derived by irradiation of the parental 308 cell has been characterized. The 308 10 Gy 5 cells unlike the parental 308 cells from malignant tumors in athymic nude mice upon subcutaneous injection. The variant 308 10 Gy 5 cells ...

International Nuclear Information System (INIS)

Apoptosis, or programmed cell death (PCD), is a fundamental process that protects organismal integrity. In earlier work, we demonstrated that over-expression of either of two anti-apoptotic members of the BCL-2 family (BCL-2 or BCL-X L could elevate the frequency of radiation-induced mutations at the autosomal TK1 locus in human TK6 lymphoblasts that express wild-type TP53. Ectopic expression of BCL-X L also elevated the frequencies of double-strand break-induced gene conversion. The purpose of this study is to determine if BCL-2 family proteins promote radiation mutagenesis indirectly through their suppression of PCD, or whether the 'pro-mutagenic' function of these proteins can be separated from their anti-apoptotic function. We developed stable transfectants of TK6 cells that express a mutated form of BCL-X L with a single amino acid substitution in the BH1 domain that is known to interfere with the ability to suppress PCD (BCL-X L gly159ala). We also developed ...

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Langmuir-Blodgett films have been made with 3-n-hexadecylpyrrole and 3-n-octadecylpyrrole monomers and copolymers with unsubstituted pyrrole made by chemical polymerization at the air-water interface on a subphase containing FeCl/sub 3/. Langmuir-Blodgett films consisting of mixtures of stearic acid and alkylsubstituted polythiophenes have also been made as bilayer films. The orientation of single and multilayer films on platinum substrates have been studied by Near Edge X-ray Absorption Fine Structure Spectroscopy which also gives information about charge transfer interactions between the aromatic groups and the metallic substrates. The alkylsubstituted pyrroles form highly ordered two-dimensional structures. FeCl/sub 3/ initiated copolymerization with unsubstituted pyrrole leads to a more disordered system. In the case of polythiophene-stearic acid bilayers, the stearic acid layers are highly ordered. The poly(alkyl thiophene) layers sandwiched between stearic ...

British Library Electronic Table of Contents (United Kingdom)

PurposeThis prospective study followed 61 patients who were partially dentulous and considered to have insufficient bone volume for routine implant treatment and consequently underwent sinus inlay bone grafting.Patients and MethodsThe patients were treated with maxillary sinus floor augmentation with particulated autogenous bone from the mandibular ramus/corpus. After a healing period, dental implants (n = 180) were installed.ResultsRadiographic examination revealed average residual vertical bone heights of 6.5 mm in the first premolar region, 3.8 mm in the second premolar region, 3.5 mm in the first molar region, and 2.6 mm in the second molar region. The average implant lengths were 12 mm in the first premolar region and 11 mm in the second premolar, first, and second molar regions. All ...

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The effect of irradiation on the tensile properties of oil palm empty fruit bunch (OPEFB) fiber reinforced poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blend using HAAKE Rheomixer at 150 deg. C. The composites were then irradiated by using a 3.0 MeV electron beam machine at doses ranging from 0 to 100 kGy in air and room temperature. The tensile strength, Young's modulus, elongation at break and gel fraction of the composites were measured. Comparative studies were also made by using poly(methyl acrylate) grafted OPEFB fiber in the similar blend system. An increase in tensile strength, Young's modulus and gel fraction, with a concurrent reduction in the elongation at break (Eb) of the PVC/ENR/OPEFB composites were observed upon electron beam irradiation. Studies revealed that grafting of the OPEFB fiber with methyl acrylate did ...

International Nuclear Information System (INIS)

Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is considered to give ...

British Library Electronic Table of Contents (United Kingdom)

Hematopoietic stem cell transplantation provides the only potential curative option in many patients with hematological malignancies. Finding a suitably matched donor in a timely manner is often difficult. However, most patients have a partially HLA-mismatched (HLA-haploidentical) first-degree relative readily available. Historically, HLA-haploidentical bone marrow transplantation (BMT) has been considered extremely high risk due to high rates of life-threatening graft-versus-host disease (GVHD) and non-relapse mortality (NRM). Modifications of the stem cell graft, such as T-cell depletion, have resulted in poor rates of engraftment. We have recently completed a phase II clinical trial of nonmyeloablative HLA-haploidentical hematopoietic BMT followed by post-transplantation high-cyclophosp...

British Library Electronic Table of Contents (United Kingdom)

The most advanced frontier of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is represented by the use of an HLA-partially matched relative as donor. In this type of transplantation, donor-derived natural killer (NK) cells, which are alloreactive towardtoward recipient cells, significantly contribute to the eradication of leukemia blasts. Alloreactive NK cells may also kill host dendritic cells and T lymphocytes, thus preventing graft-versus-host disease and graft rejection, respectively. Sophisticated strategies of adoptive infusion of T-cell lines/clones specific for the most life-threatening pathogens (namely cytomegalovirus, Epstein-Barr virus, Aspergillus and Adenovirus) have been envisaged, and successfully tested in a few pilot trials, to protect the recipient in the...

Science.gov (United States)

Before electroless plating, polymer surfaces must be sensitized and/or activated by using either the conventional two-step or one-step process. The latter stage is a compulsory one to make such surfaces catalytic, e.g., for Ni-P deposition. These processes are performed here using O{sub 2}, NH{sub 3}, or N{sub 2} plasma pretreatments. Reaction mechanisms are proposed for each of the processes and for each type of surface considered (oxygenated or both oxygenated and nitrogenated by the plasma treatment). Direct palladium chemisorption onto nitrogenated groups is highlighted. This allows one to simplify the process making the surface catalytic via elimination of the use of SnCl{sub 2} and to extend the method to any polymer. An additional interest of the plasma treatments, besides their high efficiency in grafting chemical functions, is to perform this grafting at will on selected areas which results in selective metallization.

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Abstract Flame retardants (FRs) are used for in protection against fire. Organic inorganic hybrids could become one of the most promising FR solution in the future. In this paper, the synthesis, the characterization and the use as FRs and filler of grafted titania and alumina with 2 chloroethylphosphonic acid are presented. These hybrids contain 3.8 3.24% P and have good flame retardance when they are incorporated into unsaturated polyester resins. Alumina treated with 2 chloroethylphosphonic acid performed better than titania. The advantage of this approach is the use of these hybrid materials as filler and FR, in the same time, and the increase in flame retardancy by synergistic effect between alumina phosphorus and chlorine, for unsaturated polyester resins. Copyright 2010 John Wiley & ...

British Library Electronic Table of Contents (United Kingdom)

Atrial fibrillation (AF) is common after coronary artery bypass grafting (CABG) and increases the morbidity and cost. Amiodarone reduces AF after CABG. Ranolazine, an antianginal agent, also prolongs atrial refractoriness and inhibits after depolarizations and triggered activity; effects that could decrease AF after CABG. The present study compared amiodarone versus ranolazine for the prevention of AF after CABG. A retrospective cohort study of patients undergoing CABG at Aspirus Hospital from June 2008 to April 2010. The patients received either amiodarone (400 mg preoperatively followed by 200 mg twice daily for 10 to 14 days) or ranolazine (1,500 mg preoperatively followed by 1,000 mg twice daily for 10 to 14 days). The primary end point was any identified AF after CABG. A total of 393 ...

International Nuclear Information System (INIS)

Composite materials of synthetics (based on monomers, oligomers and thermoplastics) and of natural polymers (wood and other fibrous cellulosics) prepared by radiation processing, offer valuable structural materials with enhanced coupling forces between the components. The applied polymer chemistry of such composites shows several common features with that of radiation grafting, e.g. the polymerization rate of oligomer-monomer mixtures in wood remains in most cases proportional to the square-root of the initiating dose-rate, just as in the simultaneous grafting, demonstrating that the chain termination kinetics remain regularly bimolecular in the corresponding dose-rate ranges. In the processing experiences of such composites, low dose requirement, easy process-control, and good technical feasibility have been found for composites of wood with oligomer-monomer mixtures, for coconut fibres with unsaturated polyesters and for pretreated wood fibre ...

CERN Document Server

The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are determined in part by the collective plasma modes of the participating charged particles, e.g. electrons and protons. The radiation energy required for such low energy nuclear reactions may be supplied by the applied voltage required to push a strong charged current across a metallic hydride surface employed as a cathode within a chemical cell. The electroweak rates of the resulting ultra low momentum neutron production are computed from these considerations.

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Irradiation of EP-823 (16Cr12MoWsiVNbB) ferritic-martensitic steel with 7-MeV Ni++ ions and with 30- and 70-keV He+ ions at a temperature of 500?C was followed by an increase in the microhardness, which was due to both radiation point defects and changes in the phase composition and the dislocation structure of the steel. It was found that the dependence of the largest relative increase in the microhardness on the concentration of radiation-induced point defects in the near-surface region of the steel under irradiation with different ions correlated with an analogous dependence of the surface segregation of silicon and chromium.

International Nuclear Information System (INIS)

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at #gamma##gamma# colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of #mu#"+#mu#"-, #tau#"+#tau#"-, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan#beta#-bar 5 (30) and large (small) charged Higgs-boson masses.

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Two patients who developed large intracranial vessel occlusion after standard radiation therapy for brain tumor are described. This form of vascular occlusion is usually seen in patients who have previously been treated by radiotherapy for intracranial tumor who then develop a relatively acute change in neurologic status. Histology of the lesion mimics accelerated focal arteriosclerosis. The clinical and radiographic manifestations of one case were highly atypical. The vasculopathy became evident shortly after termination of radiation therapy for a fourth ventricular ependymoma, and the angiographic picture stimulated a diffuse arteritis. The second patient was more typical, with clinical symptoms developing 12 years after radiation therapy for an oligodendroglioma. Occlusion of a proximal vessel that had been included in the radiation port was demonstrated radiographically and confirmed by pathologic examination. The clinical, angiographic, and histologic features of these two cases ...

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Photoluminescence spectroscopy measurements were carried out for silicon 50{mu}m BSFR space solar cells irradiated with 1MeV electrons with a fluence exceeding 1 x 10{sup 16} e/cm{sup 2} and 10MeV protons with a fluence exceeding 1 x 10{sup 13} p/cm{sup 2}. The results were compared with the previous result performed in a relative low fluence region, and the radiation-induced defects which cause anomalous degradation of the cell performance in such large fluence regions were discussed. As far as we know, this is the first report which presents the PL measurement results at 4.2K of the large fluence radiation irradiated silicon solar cells. (author)

International Nuclear Information System (INIS)

Nickel ion radiation at 500 C was shown to have a strong effect on the surface electrochemistry and intergranular corrosion (IGC) of stainless steel (SS). Measured current densities in a 1 N sulfuric acid solution at room temperature were increased at active-passive, passive, and transpassive potentials. Radiation effects on the current decay behavior and susecptibility to IGC were similar for a fine-grained (FG) S alloy and for a very large-grained (LG) SS. Radiation-induced segregation (RIS) at the surface was believed to promote higher currents at short times, whereas segregation at grain boundaries was responsible for IG attack. Analytical electron microscopy (AEM) measurements revealed chromium and iron depletion plus Ni and silicon enrichment at grain boundaries in irradiated specimens. Si enhanced dissolution at transpassive potentials, whereas Cr depletion did the same at active-passive and passive potentials.

International Nuclear Information System (INIS)

Increased levels of epidermal growth factor receptor have been reported in a variety of tumors, including pulmonary squamous cell carcinomas in man. The purpose of this study was to determine if increased levels of epidermal growth factor (EGFR) were present in lung tumors from Beagle dogs that had been exposed to "2"3"9PuO_2- Using immunohistochemical techniques, sections from 17 lung tumors were examined for the presence of EGFR. Seven of the tumors were strongly positive for EGFR; the remainder of the tumors and the normal lung sections were negative. The positive immunostaining could not be correlated with the histologic phenotype of the tumors. Work is in progress to determine the level of EGFR in preneoplastic, proliferative epithelial foci in the Iung. (author)

International Nuclear Information System (INIS)

The effect of exposure to gamma rays on LPO contents in liver, spleen and kidney of mice and the anti-lipid-peroxidation of preparations of chinonin, tannic acid and squalene were reported. All these preparations were given by intragastric perfusion. For LPO, a modified method of TBA spectrophotometry was used for determination. The results show that LPO contents in tissues increased 72 h after whole-body exposure of mice to gamma rays, that in range of 0-4 Gy, there was a linear relationship between radiation doses and LPO contents, and that all three preparations were effective in reduction of the LPO content in liver, spleen and kidney of mice, with chinonin (at dose of 0.35 mg/mouse#centre dot#day) being more effective than tannic acid (at dose of 15 mg/mouse#centre dot#day) and squalene (at dose of 0.6 mg/mouse#centre dot#day).

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Data are presented to support the hypothesis that the initial step in the morphologic transformation of irradiated rodent (BALB/3T3) cells is a frequent cellular event involving a large fraction of the irradiated population. This process appears to involve DNA damage, but not to represent a targeted mutation in specific structural gene(s). Morphologic transformation and immortalization appear to be distinct steps in the overall process of transformation. In contradistinction to rodent cells, immortalization is a very rare event in human diploid cells which is induced at extremely low frequencies. The hypothesis is presented that immortality develops among clones of cells bearing stable chromosomal rearrangements which emerge during the proliferation of a population of radiation damaged cells.

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The content and biosynthesis of glycosaminoglycans (GAGs) were studied in pig thigh muscle after acute local {gamma}-irradiation. Seven months following irradiation, the muscular tissue next to the irradiation cone was replaced by severe mutilating fibrosis delimited by an intermediary perifibrotic zone. Results showed a parallel increase of collagen and GAG content in perifibrotic and fibrotic tissues. Sulphated GAGs, heparan sulphate and dermatan sulphate were preferentially accumulated in fibrotic tissue, while the hyaluronic acid content increased only slightly. Synthesis of sulphated GAGs was more elevated in fibrotic tissue than in perifibrotic zone as compared with normal muscle. Seven months after irradiation well-developed fibrotic tissue continued to synthesize and to accumulate extracellular matrix macromolecules. (Author).

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Since several years we apply the radiation-grafting technique to prepare polymeric membranes for application in polymer electrolyte fuel cells (PEFCs). Our investigations presented here focus on changes in toughness of these materials after the various synthesis steps and the importance of membrane toughness for their application in PEFCs. (author) 2 figs., 4 refs.

Science.gov (United States)

Previous investigations have shown that both the early biological response and the mechanical properties of a porous hydroxyapatite bone graft substitute are highly sensitive to its pore structure. The objective of this study was to evaluate whether the pore structure continued to influence bone integration in the medium to long term. Two screened batches of porous hydroxyapatite (PHA) designated as batch A and batch B, with porosities of approximately 60 and 80%, respectively, were selected for this study and implanted for periods of 5, 13, and 26 weeks into the lower femur of New Zealand White rabbits. Histomorphometric analysis of the absolute volume of bone ingrowth within batch A and B implants from 5 to 26 weeks showed that the absolute volume of bone ingrowth was consistently lower in batch A (10-21%), compared to batch B implants (24-31%). However, when the volume of bone ingrowth was normalised for the available pore space, this difference was reduced ...

Science.gov (United States)

The safety of tissue allografts has come under increased scrutiny due to recent reports of allograft-associated bacterial and viral infections in tissue recipients. We report that 50 kGy of gamma irradiation, nearly three times the dose currently used, is an effective pathogen inactivation method when used under optimized conditions that minimize damage to the tissue. Cancellous bone dowels treated with a radioprotectant solution and 50 kGy of optimized irradiation had an ultimate compressive strength and modulus of elasticity equal to conventionally irradiated (18 kGy) and non-irradiated control bone grafts. We subjected bone dowels treated with this pathogen inactivation method to an in vitro cytotoxicity test using three different mammalian cell lines and concluded that the treated grafts were not cytotoxic. The log reduction of nine pathogens spiked into radioprotectant-treated bone irradiated to 50 kGy was also tested. We achieved 4.9 logs ...

International Nuclear Information System (INIS)

On 21 October 1994, three brothers entered a waste repository at Tammiku, Estonia, without authorization and removed a metal container enclosing a caesium-137 source. During the removal the source was dislodged and fell to the ground. One of the men picked up the source, placed it in his pocket and took it to his home in the nearby village of Kiisa. Very soon after entry into the repository he began to feel ill, and few hours later he began to vomit. The man was subsequently admitted to hospital with severe injuries to his leg and hip and died on 2 November 1994. The injury and subsequent death were not attributed to radiation exposure, and the source remained in the man's house with his wife and stepson and the boy's great-grandmother. The boy was hospitalized on 17 November with severe burns on his hands, and these were identified by a doctor as radiation induced. The authorities were alerted, and the Estonian Rescue Board recovered the ...

Science.gov (United States)

Endothelial dysfunction and increased platelet aggregation may be involved in the pathogenesis of normal tissue radiation toxicity. This study assessed clopidogrel, an inhibitor of ADP-induced platelet aggregation, as a modulator of intestinal radiation injury (radiation enteropathy). Rat small intestine was exposed to 21 Gy X-radiation. Clopidogrel (20 mg/kg/day) or vehicle was administered from 2 days before to 10 days after irradiation. Structural radiation injury, neutrophil infiltration, smooth muscle cell proliferation, collagen content, and TGF-beta1 expression were assessed 2 weeks (early phase) and 26 weeks (delayed phase) after irradiation, using quantitative histology and immunohistochemistry, morphometry, and real-time fluorogenic probe RT-PCR. Irradiated intestine exhibited significant histopathologic injury, reduced mucosal surface area, vascular sclerosis, intestinal wall fibrosis, increased collagen content, and increased TGF-beta1 expression. Clopidogrel reduced ...

International Nuclear Information System (INIS)

7,959 patients were examined by radionuclide in-vivo methods within one year, 1,228 of them by application of "1"3"1I-iodide (radioiodine test and scintigraphy of the thyroid gland). In compliance with the ICRP publications 26 and 27 the somatically effective equivalent dose H/sub s,eff/ was ascertained for several examining methods, derived from it the collective dose S/sub s,eff/ and considering a part of manifestation resulting from the age distribution of patients, the somatic risk regarding radiation-induced malignoma with fatal termination. For the patients examined by "1"3"1I-iodide the collective dose was 79.9 man x Sv and the mean somatic risk 30 x 10"-"5 with a part of manifestation of 0.39 accordig to 0.37 radiation-induced malignomas with fatal termination. For all patients examined by other radiopharmaceuticals the collective dose was 14.07 man x Sv, the mean somatic risk 1.7 x 10"-"5 according to 0.11 malignomas. The average ...

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The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of secondary sites that generate a cationic mechanism. The two ...

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The effects of lead on the development of the nervous system are of immediate concern to human health. While it is clear that lead can affect neuronal development at levels of exposure within the range found in the environment, the particular mechanism of the disruption is not readily ascertained. The goal of the authors research is to develop a model system in which the effects of lead on central nervous system development can be demonstrated. To study neuronal development in a system that minimizes such difficulties, the authors have grafted discrete brain regions derived from rat fetuses into the anterior chamber of the eye of adult hosts. The brain pieces continue organotypic development in the eye, but are isolated from possible secondary changes due to alterations in the development of the endocrine and other somatic systems because the adult host has these systems already fully developed. Using this system, they have discovered that lead induces a ...

Science.gov (United States)

In this paper, we prepared a novel cationic self-assembled micelle from poly(epsilon-caprolactone)-poly(ethyl glycol)-poly(epsilon-caprolactone) grafted polyethyleneimine (PCEC-g-PEI). The PCEC-g-PEI micelles, formed by self-assembly method, had mean particle size of ca. 82 nm and zeta potential of +22.5 mV at 37 degrees C, and could efficiently transfer pGFP into HEK293 cells in vitro. Meanwhile, as a model hydrophobic chemotherapeutic drug, honokiol was loaded into PCEC-g-PEI micelles by direct dissolution method assisted by ultrasonication. The honokiol loaded cationic PCEC-g-PEI micelles could effectively adsorb DNA onto its surface, while it could release honokiol in an extended period in vitro. This study demonstrated a novel DNA and hydrophobic chemotherapeutic drug co-delivery system. PMID:21121283

British Library Electronic Table of Contents (United Kingdom)

Lung transplantation has become an accepted option for many patients with end-stage pulmonary diseases. Anesthesia and surgery following lung transplantation may be required for various diseases that may affect both systemic organs and the transplanted graft. When a patient with a lung transplant undergoes surgery, there is the potential for interference with lung function, depending on the type of intervention and its anatomical site. Accurate preoperative evaluation, an understanding of the physiology of the transplanted lung, proper airway instrumentation, individualized management of intraoperative ventilation, and fluid balance are essential for a positive perioperative outcome.

International Nuclear Information System (INIS)

Ionizing radiation, mainly in the form of #gamma#-rays from the radioisotope cobalt 60, is being used increasingly for the inactivation of contaminants in cosmetic and toiletry preparations. The treatment is applied to the product in its final pack, and therefore, it is important to recognize that the properties of the packaging materials could be affected, particularly if high radiation doses are used. The stability of a wide range of materials is discussed. The nature and extent of chemical and physical changes in plastics very much depends on the presence of antioxidants and other additives, and on the environmental conditions during irradiation. Some useful information is available from research into the use of radiation for the preservation of food - many films and laminates have been cleared for use in the United States. The low radiation doses used for the control of contaminants in cosmetic products are quite unlikely to cause changes in packaging materials which will limit the ...

International Nuclear Information System (INIS)

The spectral energy-dependence of the radiation-induced ESR signal has been studied in ovine cortical bone. Crushed bone samples were irradiated using photon beams with effective energies in the range from 0.06 to 6 MeV, and electron beams with mean energies in the range from 2 to 10 MeV. The photon and electron data were normalized to a dose to bone of 50 Gy and the results are reported as response relative to the ESR signal for photon irradiation at 1.25 MeV ("6"0Co). The photon irradiation results show that the ESR response is greatest at low energies with a relative value of 1.2 at 0.06 MeV. The relative response decreases, as the energy increases, to approximately 0.85 in the region of 2 to 3 MeV. These variations in the relative ESR responses are significantly less than the ESR energy-dependent responses reported in the literature for human tooth enamel and synthetic hydroxyapatite. An explanation for this difference is offered. For electron beam ...

International Nuclear Information System (INIS)

The high-energy radiation-induced degradation of an H-acid derivative azo dye, Apollofix-Red SF-28 (AR-28) was studied in aqueous solution by using pulse radiolysis with kinetic spectroscopic detection for transient measurements. Gamma radiolysis with UV-VIS spectroscopy and gradient ionpair HPLC separation with diode array detection were applied for following the destruction of AR-28 and measuring the products. The reactions of hydrated electron (e_a_q "-) and hydroxyl ("#centre dot#OH) radical were investigated separately. "#centre dot#OH reacts with the unsaturated bonds of the molecule. In the further reactions of the "#centre dot#OH adduct radicals, the AR-28 molecules partly reform with a slightly modified structure. The products formed in the first reaction of "#centre dot#OH and AR-28 molecules have also high reactivity towards the "#centre dot#OH radicals. For these reasons the efficiency of "#centre dot#OH radicals in discolouration of the solution is ...

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Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T{sub ...

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Color formation in aqueous solutions of the ditetrazolium salt blue tetrazolium (BT{sup 2+}) in the absence or presence of oxygen is a complex radiation chemical reaction. The final stable product is the poorly soluble diformazan violet to blue pigment having a broad spectral absorption band ({lambda}{sub max}=552 nm). The reaction of BT{sup 2+} with the hydrated electron proceeds by rapid reduction of BT{sup 2+} followed by protonation at the nitrogen closest to the unsubstituted phenyl group, via the two intermediate tetrazolinyl radicals shared by the ditetrazole ring nitrogens. The effect of solution pH, N{sub 2}O saturation, and the presence of the reducing agent dextrose are examined. The system serves as a radiochromic sensor and a dosimeter of ionizing radiations. Solutions of 5 mmol l{sup -1} BT{sup 2+} at pH 7.3 serve as dosimeters over an absorbed-dose range of approximately 0.2-6 kGy (dearated, with a range of 1-8 mmol l{sup -1} dextrose) and of about 1-15 kGy (aerated, ...

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We investigated the effect of irradiation on the kinetic characteristics of amino acid and glucose transport, and the effect on the activity of the cell membrane-bound enzyme 5'-nucleotidase and on the receptor-mediated stimulation of cyclic adenosine monophosphate synthesis by prostaglandin E1. Irradiation inhibited the sodium-dependent amino acid transport by a reduced binding of the amino acid to the transport unit. The transport of glucose, which appeared to be a sodium-independent process, was temporarily stimulated by increased maximal velocity of the transport. No effect was found on the binding to the transport unit. Irradiation increased the 5'-nucleotidase activity and decreased the prostaglandin E1-stimulated cyclic adenosine monophosphate synthesis 48 h after exposure to 20 Gy. It is concluded that irradiation decreases sodium-dependent transport by impairment of the transport unit, does not impair a sodium-independent process, and has opposite effects on ...

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The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of ...

International Nuclear Information System (INIS)

We present changes in the p53 gene in a group of 70 thyroid tumours and 40 blood samples obtained from children from Belarus. Three thyroid tumours show a polymorphism in exon 6 (codon 213) and 5 tumours show a polymorphism in intron 6, 37 bp upstream to the 5'-end of exon 7. Only one patient has a mutation in exon 7 (codon 258) resulting in an amino acid substitution in the protein p53. The distribution of polymorphisms in the 40 blood samples was as follows: three patients had a polymorphism in exon 6 and two persons had a polymorphism in intron 6. One polymorphism in intron 6 was also found in the group of 30 healthy children from Belarus. The fact that the differences in the sequence in p53 found in the tumours was also seen in the blood of these patients demonstrates that they are polymorphisms not induced by radiation exposure. It is difficult to conclude, if the polymorphisms found by us could be associated with the predisposition to radiation-induced ...

International Nuclear Information System (INIS)

The adverse effect of moisture diffusion on the properties of wood has been one of the main weaknesses of wood. Using a gamma irradiation method, wood-polymer composites have been produced which exhibit significant improvement in mechanical properties like compression, creep deformation and creep rupture particularly at high humidity. It has been thought that the impregnation of polymer into the wood has affected the moisture diffusion in the wood, so that its adverse effects on the mechanical properties has been reduced. In this report the apparent diffusion coefficients of a Ramin wood impregnated with varying amounts of polymethyl methacrylate (PMMA) were determined using a Fick's law approach. An initial linear relationship was found for impregnation of up to 70% PMMA, after which the diffusion coefficient levels off to a maximum value, for the three environmental relative humidity levels of 40, 60 and 90(#+-#5)%. The phenomenon could be explained by means of a cylindrical model ...

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Mitotic delay is described as a classical response to radiation; however, circadian rhythmicity in cell division in vivo has not been considered by many authors. The present study investigated the relation between fluctuations reported as mitotic delay and recovery in vivo and circadian oscillations in mitotic index in mouse corneal epithelium. One aspect involved single doses (approximately 600 rad) given to mice at different circadian stages. The normal circadian rhythm in cell division was never obliterated. Inhibition of mitosis was evident but unpredictable, ranging from 6 to 15 hr after irradiation. Recovery was evident only during the daily increase in mitotic index of controls. The classical interpretation of recovery from mitotic delay may be in an in vitro phenomenon not reflecting in vivo responses, which are apparently strongly circadian stage dependent. The second portion of the study demonstrated a dose-response effect on length of mitotic delay and, to a lesser extent, ...

International Nuclear Information System (INIS)

Chemical analyses were done on the abnormal hemoglobins of the five (101 x SEC)F_1 offspring of X- irradiated adult SEC mice to determine which hemoglobin genes were expressed in each hemoglobin variant. Three offspring of irradiated SEC males did not express either of the two kinds of #alpha#-chains normally found in all SEC mice. The deficient #alpha#-chain synthesis caused these mice to exhibit an #alpha#-thalassemia similar to human #alpha#-thalassemia. Scanning electron microscopy was used to show that many erythrocytes of mice with #alpha#-thalassemia have bizarre shapes; e.g. many erythrocytes appeared flattened or had thorny projections (acanthocytes). One mutant with a tandem duplication of a segment of chromosome 7 (site of locus determining #beta#-chain structure) produced twice as much SEC as 101 #beta#-chain polypeptides. One mutant that probably arose by non-disjunction of chromosome 7's in its unirradiated 101 mother and loss of chromosome 7 from the gamete of its ...

International Nuclear Information System (INIS)

For an assessment of the future US spallation neutron source (SNS) target performance, radiation induced hardening and microstructural evolution were investigated as a function of ion dose for EC316LN stainless steel. Irradiation was carried out using 3.5 MeV Fe"+, 360 keV He"+, and 180 keV H"+ simultaneous ion-beams at 200 deg. C to simulate the damage, He and H production in the SNS target vessel wall. At low dose (< 1 dpa), the predominant defects were black dots whose number density saturated rapidly within a few dpa. This was followed by the evolution of interstitial loops whose number density saturated below 15 dpa. Although He-bubbles were not visible, severely scalloped loops suggested that the implanted He/H atoms existed in the form of small clusters. Comparison with reported neutron irradiation data showed that hardening and ductility loss occurred mostly in the black dot regime (< 1 dpa), but that good ductility (>20% ...

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The D2 antidopaminergic drug Domperidone was evaluated singly and in combination with synthetic adrenocorticoid and an H2 antihistamine for its ability to reduce the acute emetic effects of /sup 60/Co whole-body radiation. Random-source adult male dogs were fasted 12 hours, fed a standard meal, injected 44 minutes later and irradiated 47 minutes after that. Four groups of dogs were radiated after drug injections as follows: saline (Con), domperidone (Dom), cimetidine + thiethylperazine (Cim+Thi), and dexamethasone + domperidone + cimetidine (Dex+Dom+Cim). Drug quantities for dogs represented 10 mg Dom, 10 mg Thi, 20 mg Dex, and 300 mg Cim for an average human (70 ka, 1.8 m2). Subjects were exposed on an up-down schedule to determine the radiation necessary to produce vomiting in 50% (ED50) of each group. Emesis onset times, offset times, and number of episodes were recorded. The ED50 of Dex+Dom+Cim was higher than Con. Dom produced more emetic episodes than Con or Dex+Dom+Cim. This ...

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The effects of gamma and e-beam irradiation on mechanical and structural properties of nylon 66 (Ny 66), nylon 6 (Ny 6) and poly(ethylene terephthalate) (PET) fabrics used in tyres were investigated. The untreated (greige), treated cords and calendered fabrics were irradiated at different doses. It is found that the effects of high energy irradiation on greige, treated cords and calendered fabrics are similar. No protective effect of compounds used in calendering was observed against radiation-induced oxidative degradation. The deterioration effect of gamma irradiation on mechanical properties is much higher than that of e-beam irradiation for all types of samples. Limiting viscosity numbers of both gamma and e-beam irradiated nylon 6 and nylon 66 cords were found to decrease with increasing dose. It is concluded that PET calendered fabric has higher resistance to ionizing radiation. Ny 6 and Ny 66 calendered fabrics are more sensitive even at low doses. Therefore, ...

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Ionising radiation induces stable free radicals in chicken bones and in the shell of chicken eggs which can be detected, by the electrons spin resonance (ESR) technique, well beyond the shelf-life of the food and can be used for dosimetry. The method usually adopted to evaluate ``a posteriori`` the dose given during the ionising radiation treatment of food, is the dose additive method. To assess the dose, the ESR signal amplitude of the irradiated food (bone or egg shell in the present case) is measured and then the dose-effect relationship is obtained by re-irradiating the sample with some additive doses (usually of 1 kGy). The dose-effect curve is back-extrapolated and the initial given dose determined. At the Istituto Superiore di Sanita (ISS), Rome, Italy, a research programme was approved two years ago aimed to, (1) study new methodological approaches for ESR dose assessment, and (2) analyse the factors which may influence the ESR readout ...

International Nuclear Information System (INIS)

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.

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The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine glycol.and ...

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The aim of this work was to study acute alterations of the enterohepatic recirculation (EHR) of bile acids 3 days after an 8-Gy radiation exposure in vivo in the rat by a washout technique. Using this technique in association with HPLC analysis, the EHR of the major individual bile acids was determined in control and irradiated animals. Ex vivo ileal taurocholate absorption was also studied in Ussing chambers. Major hepatic enzyme activities involved in bile acid synthesis were also measured. Measurements of bile acid intestinal content and intestinal absorption efficiency calculation from washout showed reduced intestinal absorption with significant differences from one bile acid to another: absorption of taurocholate and tauromuricholate was decreased, whereas absorption of the more hydrophobic taurochenodeoxycholate was increased, suggesting that intestinal passive diffusion was enhanced, whereas ileal active transport might be reduced. Basal hepatic secretion was increased only for ...

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The aim of the paper is to review the role of interventional radiology in the management of hemodialysis vascular access and complications in renal transplantation. The evaluation of patients with hemodialysis vascular access is complex. It includes the radiology/ultrasound (US) evaluation of the peripheral veins of the upper extremities with venous mapping and the evaluation of the central vein prior to the access placement and radiological detection and treatment of the stenosis and thrombosis in misfunctional dialysis fistulas. Preoperative screening enables the identification of a suitable vessel to create a hemodynamically-sound dialysis fistula. Clinical and radiological detection of the hemodynamically significant stenosis or occlusion demands fistulography and endovascular treatment. Endovascular prophylactic dilatation of stenosis greater than 50% with associated clinical abnormalities such as flow-rate reduction is warranted to prolong access patency. The technical success ...

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Materials and methods: 12 patients with 22 coronary bypass grafts underwent intraoperative flow quantification using the transit time ultrasound method. These values were compared to postoperative MR phase shift measurements. Flow measurements were performed preoperatively in 28 coronary arteries of 20 patients. For flow measurement, we used a velocity-encoded k-space segmented gradient echo sequence with a temporal resolution of 110 or 125 ms, respectively. 6-8 pase shift images could be acquired during one cardiac cycle. Results: There was a significant correlation between intraoperative and flow measurements using velocity-encoded MR imaging (r=0.76, p<0.0001, t-test). Flow volumes determined by MR imaging were systematically larger than those determined by the transit time ultrasound method. Mean flow in coronary arteries was reduced in severely stenosed vessels (>70%) compared to normal vessels. Intra- and interobserver variability were 10.5 and ...

British Library Electronic Table of Contents (United Kingdom)

Summary: The surface coverage of amorphous silica gels used in the synthesis of silica polyamine composites has been investigated by 29Si NMR. By diluting the polyamine anchor silane, chloropropyl trichlorosilane, with methyl trichlorosilane it was found that surface coverage could be markedly improved for a range of amine polymers after grafting to the silica surface. The commensurate decrease in the number of anchor points and increase in the number of free amines results in an increase in metal capacity and/or an improvement in capture kinetics. Solid state CPMAS-13C NMR has been employed to investigate the structure and metal ion binding of a series of these composite materials. It is reported that the highly branched polymer, poly(ethyleneimine) (PEI) exhibits much broader 13C NMR res...

British Library Electronic Table of Contents (United Kingdom)

Abstract Poly(butylene terephthalate) (PBT) composites containing multiwalled carbon nanotubes (MWCNTs) were prepared using a melt-blending process and used to examine the effects on the composite structure and properties of replacing PBT with acrylic acid-grafted PBT (PBT-g-AA). PBT-g-AA and multihydroxyl-functionalized MWCNTs (MWCNTs-OH) were used to improve the compatibility and dispersibility of the MWCNTs within the PBT matrix. The composites were characterized morphologically using transmission electron microscopy, and chemically using Fourier transform infrared, solid-state 13C NMR and UV-visible absorption spectroscopy. The antibacterial and electrical conductivity properties of the composites were also evaluated. MWCNTs or MWCNTs-OH enhanced the antibacterial activity and electric...

British Library Electronic Table of Contents (United Kingdom)

The treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). The purpose of this study was to evaluate the clinical and radiological outcome of revision THA using jumbo cups for acetabular reconstruction after applying the bone-grafting technique. We studied 17?patients with acetabular defects ranging from Type 2A to Type 3A according to Paprosky`s classification. According to the AAOS-score twelve patients were classified as Type II and five patients as Type III. Uncemented press-fit cups with an outer diameter larger than 64?mm were used in all cases. Fifteen patients received morselized bone allografts. In eight patients an additional screw fixation was necessary. The mean follow-up period was 82?months (range 33?149). The mean Harris Hip...

British Library Electronic Table of Contents (United Kingdom)

In several vertebrate classes, the M?ller glia are capable of de-differentiating, proliferating, and acquiring a progenitor-like state in response to acute retinal injury or in response to exogenous growth factors. Our previous study has shown that M?ller cells can be activated and de-differentiated into retinal progenitors during Royal College of Surgeons (RCS) rats' degeneration, although the limited proliferation cannot maintain retinal function. We now report that rat retinal stem cells (rSCs) transplanted into RCS rats slowed the progression of retinal morphological degeneration and prevented the functional disruption. Further, we found that retinal progenitor cells labeled with Chx10 were increased significantly after rSCs transplantation, and most of them are mainly from activated M...

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Wood plastic composite (WPC) of kadom, simul, mango and debdaro were prepared with two monomers methylmethacrylate (MMA) and butylmethacrylate (BMA) using high energy ionizing radiation. X-ray diffraction and scanning electron microscope (SEM) studies reveal that significant grafting occurred with wood fiber. Electric properties like resistivity and dielectric constant of both wood and WPC were measured under different moisture contents and relative humidities. The resistivities of wood decreased dramatically with increase of moisture content, but those of WPC decreased very slowly with moisture content. The dielectric constant of wood increased significantly with moisture content but no significant difference was observed in the case of WPC within the range of moisture contents studied. The dielectric constants of untreated wood also increased with their densities. (author).

British Library Electronic Table of Contents (United Kingdom)

Nonfunctioning pancreatic endocrine tumors (PETs) are rare and generally asymptomatic. A 68-year-old woman who had refused treatment for a pancreatic mass, revealed by ultrasonography to be 55 mm in diameter, was referred to us again 29 months later with jaundice. Investigations showed an 82-mm tumor in the head of pancreas, exposed from the papilla of Vater to the duodenal lumen. After biliary decompression and drainage, we performed pancreatoduodenectomy with resection of the portal vein and superior mesenteric vein, followed by reconstruction using a cylindrically customized autologous graft harvested from the right ovarian vein. The tumor was resected curatively. Microscopically, it consisted of trabecular and ribbon-like arrangement of neoplastic cells. Immunohistochemical staining wa...

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The grafted human glioblastoma cell CB109 was used as a model for intralesional therapy with 131I-labelled hyaluronectin glycoprotein (131I-HN). 131I-HN bound specifically to in situ hyaluronic acid (HA), a main component of the extracellular matrix which is involved in tumour invasion. Labelling experimental conditions were determined and, finally, 25 {mu}Ci/{mu}gHN, 1 {mu}g chloramine-T/{mu}gHN and a 60-s stirring period provided a 131I-HN preparation with an optimal affinity for HA (64% compared to unlabelled HN). Following intratumoral injection, 131I-HN was retained with a limited diffusion outside the tumour. On day 4 the radioactivity concentrated in the tumour was still 25 times greater than that in the liver, spleen and kidneys combined. For therapeutic assays, 65 {mu}Ci 131I-HN was injected into the tumour, resulting in a delivery of 6.8 Gy over a 7-day period. Controls received unlabelled HN, heat-inactivated HN, a mixture of inactivated HN plus free ...

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Silanization of the silica gel surface in the synthesis of silica gel polyamine composites uses (chloropropyl)-trichlorosilane (CPTCS). It is possible to substitute a molar fraction of reagent CPTCS with methyltrichlorosilane (MTCS), creating a mixed silane surface layer. Two types of silica gels were modified with a series of MTCS:CPTCS molar ratios. Solid-state CP/MAS 29Si and 13C NMR spectroscopies were used to evaluate the surface silane composition. Surface silane coverage was markedly improved for the resulting gels. When polyamines were grafted to the resultant MTCS:CPTCS silane layers, it was shown that the decrease in the number of propyl attachments to the polyamine resulted in increased quantities of ''free amines''. Optimum MTCS:CPTCS ratios were determined for three polyamines grafted onto one silica gel. A substantial free amine increase was observed for poly(allylamine) (PAA). Metal uptake ...

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Hyaluronic acid (HA) is a significant component of the extracellular matrix (ECM), particular interest being shown herein in synovial fluid. The present study aims to investigate the degrading effects of X-ray radiation on HA at radiotherapy doses. Measurements of viscosity and shear stresses on HA solutions have been made at different shear rates using various types of viscometer for different concentrations in the range 0.01-1% w/v of HA. The HA has been subjected to doses of 6 MV photon radiation ranging from 0 to 20 Gy, the major emphasis being on doses below 5 Gy. It is found that there is a dose-dependent relationship between viscosity and shear rate, viscosity reducing with radiation dose, this being related to polymer scissions via the action of radiation-induced free radicals. The dependency appears to become weaker at higher concentrations, possibly due to the contribution to viscosity from polymer entanglement becoming dominant over that from mean ...

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In this paper we discuss the results of thermoluminescence (TL) studies carried out on freshly quenched crystals of KBr doped with {approx} 50 ppm of Eu{sup 2+} ions which were X-irradiated at room temperature. The TL glow curve of this phosphor material consists of three glow peaks at 355, 376 and 398 K whose intensities increased as a function of X-irradiation time. The TL glow peaks were analyzed by the total curve-fitting method in order to obtain the characteristic parameters; activation energy, pre-exponential factor and kinetic order. The spectral character of the emission recorded during thermoluminescence was found to be the same for all glow peaks and consists of a broad band centered at {approx} 420 nm. It is proposed that the model of the TL process most consistent with our experimental results is one in which the Eu{sup 2+} impurity acts as an electron trap during the irradiation process and that the radiation induced center ...

International Nuclear Information System (INIS)

Beagle dogs were given single, whole-body "6"0Co gamma-radiation exposures at one of three prenatal (8, 28, or 55 days postcoitus) or three postnatal (2, 70, or 365 days postpartum) ages to evaluate the relative radiosensitivity of various stages of brain development. A total of 387 dogs received mean doses ranging from 0.16 to 3.83 Gy, and 120 dogs were sham-irradiated. Groups of dogs were sacrificed at preselected times from 70 days to 11 years of age. Brain weight decreased significantly with increasing dose in dogs irradiated at 28 or 55 days postcoitus or at 2 days postpartum. Irradiations at 28 days postcoitus were dramatically more effective in causing a reduction in brain weight than those at 55 days postcoitus or 2 days postpartum. Among dogs given 1.0 Gy or more and followed for up to 4 years, there was a radiation effect evident at all three sensitive exposure ages. Among dogs given lower doses and followed for up to 11 years, there was a significant decrease in brain weight ...

International Nuclear Information System (INIS)

The radiation decimal reduction dose (D_1_0) of toxigenic Vibrio cholerae O1 El Tor, Inaba was determined in vitro (0.13 kGy) and in inoculated fresh fillets of saurel (Trachurus picturatus murphyi) (0.12 kGy) and another Pacific fish species known in Peru as ''lisa'', Mugil cephalus (0.13 kGy), both of which are frequently consumed raw in ''ceviche''. The D_1_0 value was similarly determined in tails of the shrimp species Penaeus vannamei (0.13 kGy). In a second phase of the study, radiation doses in the range 1.0-4.0 kGy were evaluated for use in microbiological shelf-life extension of the selected seafood, and for adverse effects on various sensory attributes (appearance, odor, flavor, and texture). A dose of 1.0 kGy doubled the microbiological shelf-life of fish fillets during post-irradiation storage at 0-1 deg. C to approximately 30 days. This dose was deemed optimal also for preserving all sensory characteristics evaluated except appearance, due to a darkening of fillets. Best ...

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Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterilisable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its physical properties. Therefore, radiolytic stabilization of PMMA is important for to become it commercially radio sterilisable. In this work we investigated the radiolytic stabilization of PMMA by using HALS (Hindered Amine Light Stabilizer) additive, commercially used for photo and thermo oxidative stabilization of polymers. The investigation of the radiation-induced main chain scissions was carried out by viscometric method. The additive added to the polymer system at 0.3 % w/w promotes a molecular radioprotection of 61%. That means a reduction of G value (scissions/100 eV) from 2.6 to 1.0. In addition, the glassy transition temperature (Tg) of PMMA (no additive), significantly changed ...

International Nuclear Information System (INIS)

Full text: The general population is daily exposed to chronic, low doses of ionizing radiation (IR) from both natural and artificial sources. The biological consequences of acute, high dose IR exposure can be readily determined; however, the nature and significance of low dose, low dose-rate IR effects are still the subject of debate. Confounding the issue, are the phenomena collectively referred to as the Radiation-induced Bystander Effect (RIBE). The RIBE describes a collection of in vitro observations that suggest the presence of a soluble, transmissible factor(s) released from irradiated cells that can induce a biological response in un-irradiated cells. The induction, nature and magnitude of the RIBE varies between cell culture systems, radiation sources and end-points measured. Efforts to confirm the presence of the RIBE in vivo have been confined to in vivo-like culture systems and limited work with tumour and bone-marrow transplantation models. Validation ...

Science.gov (United States)

Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area were evaluated. Peripheral blood samples were prepared and exposed to challenge dose of 0 and 2 Gy. Lymphocytes were scored using analysis of metaphase, for the presence of chromosomal aberrations. An ...

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The radiation-induced microstructural changes have been studied by cross-sectional transmission electron microscopy for single-crystal {alpha}-Al{sub 2}O{sub 3} samples irradiated with triple ion beams (0.25 MeV H{sup +}, 0.6 MeV He{sup +} and 2.4 MeV O{sup 2+}; `Triple (A)`), (0.33 MeV H{sup +}, 0.45 MeV He{sup +} and 1.3 MeV O{sup +}; `Triple (B)`) and three consecutive single ion beams (0.3 MeV H{sup +} ion followed by 0.6 MeV He{sup +} and then 0.8 MeV O{sup +} ions) at 650 C to doses in the range 0.1-8.4 dpa at the damage peak. In the specimen irradiated with Triple (A), having the same average projected range to a total peak dose of 3.7 dpa, cavities with an average diameter of 13 nm were formed between 1.2 and 1.75 {mu}m in depth causing a swelling of 0.1% at the peak, which is larger than those of the specimens irradiated with other conditions. The extent of the cavity-introduced region is some 40% smaller than observed in the damage region due to the ...

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We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these results indicate that recombinational ...

International Nuclear Information System (INIS)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22"oC. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm"-"1 (amide I), 1200-1300 cm"-"1 (amide III) and 550-1030 cm"-"1 (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm"-"1 are tyrosines and cysteines. The radiation-induced changes in the secondary structure were determined from amide I and III bands. Quantitative estimation using the ...

International Nuclear Information System (INIS)

The development of leukemia and thyroid cancer is characterized by activation of the abl oncogene and ret oncogene, respectively. In order to clarify the relationship between these gene aberrations and radiation, the pro-myelogenous leukemia-derived cell line HL60 and the thyroid cancer-derived cell line 8505C, were irradiated in vitro with 100Gy of X-rays. RNA was then extracted from 10"8 cells of the respective cell lines and examined by the reverse transcription PCR method for rearrangements of abl and ret genes. Five kinds of positive bands were observed in the HL-60 cells irradiated with 100Gy of X-ray. Similarly, six positive bands were also observed in the 8505C cells irradiated with 100Gy. In vitro X-irradiation activation of oncogenes found in radiation induced cancers imply that gene rearrangement by X-rays is involved in the development of malignant tumors. Furthermore, in an experiment to detect radiation effects in A-bomb ...

International Nuclear Information System (INIS)

The effects of the antioxidants, vitamin E, propyl gallate, 2-t-butyl-4-methoxy phenol (BHA), 2,6-di-t-butyl-4-methoxy phenol (BHT), nor-dihydroguaiaretic acid (NDGA) and diphenyl-p-phenylene diamine (DPPD) in concentrations ranging between 0.001 per cent and 0.1 per cent have been tested on lipid peroxide formation in synthetic diet mixtures containing herring oil (10 per cent) mixed with starch (90 per cent) irradiated with #gamma#-ray doses of 100 to 2000 krad. On a weight basis NDGA, DPPD, BHA and BHT were most effective and vitamin E and propyl gallate were least effective. An antioxidant concentration of 0.01 per cent normally protected against peroxide formation after a dose of 500 krad but if the dose was increased to 1000 or 2000 krad, much higher doses of antioxidant, up to 0.1 per cent, were required to give protection. Antioxidants prevented peroxide developing during post-irradiation storage even when added after irradiation. Antioxidants were partially or completely ...

International Nuclear Information System (INIS)

We have studied in detail the gamma radiation induced changes in the electrical properties of the (TeO_2)_0_._9 (In_2O_3)_0 _._1 thin films of different thicknesses, prepared by thermal evaporation in vacuum. The current-voltage characteristics for the as-deposited and exposed thin films were analysed to obtain current versus dose plots at different applied voltages. These plots clearly show that the current increases quite linearly with the radiation dose over a wide range and that the range of doses is higher for the thicker films. Beyond certain dose (a quantity dependent on the film thickness), however, the current has been observed to decrease. In order to understand the dose dependence of the current, we analysed the optical absorption spectra for the as-deposited and exposed thin films to obtain the dose dependences of the optical bandgap and energy width of band tails of the localized states. The increase of the current with the gamma ...

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In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and stress corrosion cracking ...

International Nuclear Information System (INIS)

Simulation irradiation experiments were carried out to investigate the formation processes and contribution to hardening of radiation-induced features in low alloy steels. Medium Cu (0.12 and 0.16%) and low Cu (0.03%) A533B steels were irradiated with 3 MeV Ni ions and 5 MeV electrons, and in KUR at 290degC. Irradiated steels were examined by three-dimensional atom probe, positron annihilation, high-resolution transmission electron microscopy and hardness measurements. Electron irradiation caused almost the same hardening as KUR irradiation in medium Cu steels under almost the same dose rate and dose conditions, whereas the formation of larger, denser and more Cu enriched clusters and smaller accumulation of single vacancies were confirmed for KUR irradiation. This indicated that cascade damage provides additional cluster nucleation sites to compensate for lower free point defect production. High dose rate Ni ion irradiation produced Mn-Ni-Si clusters and ...

Science.gov (United States)

Recently, various types of allogeneic skin substitutes including cultured epidermal substitute (CES), cultured dermal substitute (CDS), and cultured skin substitute (CSS), which are composed of keratinocytes and/or fibroblasts as the cellular component(s), have been used as biological wound dressings. In our study, the allogeneic CDS was prepared by plating fibroblasts on a spongy collagen. The clinical evaluation was conducted using fresh or cryopreserved allogeneic CDS. In 145 of our clinical cases, 95% (138/145) of various wounds were evaluated as achieving good or excellent results, including 96% (22/23) of deep dermal burns (DDB) and dermal burns (DB), 100% (53/53) of partial-thickness donor wounds, 91% (21/23) of traumatic skin defects, 100% (5/5) of pressure ulcers, 82% (9/11) of chronic skin ulcers, 100% (6/6) of coverage for debrided DB, and 92% (22/24) of coverage for autologous meshed graft. The results obtained in our study suggest that the allogeneic ...

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The surface coverage of amorphous silica gels used in the synthesis of silica polyamine composites has been investigated by 29Si NMR. By diluting the polyamine anchor silane, chloropropyl trichlorosilane, with methyl trichlorosilane it was found that surface coverage could be markedly improved for a range of amine polymers after grafting to the silica surface. The commensurate decrease in the number of anchor points and increase in the number of free amines results in an increase in metal capacity and/or an improvement in capture kinetics. Solid state CPMAS-13C NMR has been employed to investigate the structure and metal ion binding of a series of these composite materials. It is reported that the highly branched polymer, poly(ethyleneimine) (PEI) exhibits much broader 13C NMR resonances than the linear polymers poly(allylamine) (PAA) and poly(vinylamine) (PVA). These results are understood in terms of the low energy conformations calculated from molecular modeling ...

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Severe damage to the pelvic viscera is a complication of irradiation therapy that, unfortunately, cannot always be avoided. Resulting rectal and rectocolonic strictures, rectovaginal fistulas, and shortening and stenosis of the vagina present very difficult problems that frequently require a colostomy for relief and may permanently impair sexual function. The authors present a new approach to correction of these unfortunate lesions based on the use of proximal nonirradiated colon which serves as a vascular pedicle graft to correct the defect without a complicated and massive resection. Twenty-two such operations have been done with 19 satisfactory to excellent results and two total failures (one death from small bowel complications). All patterns and combinations of irradiation injury have been found amenable to this technique of repair. These have included both web and linear strictures with and without fistulas. In half of the patients, it was possible to make ...

International Nuclear Information System (INIS)

To compare clinical effectiveness of Viabil-covered stents versus uncovered metallic Wallstents, for palliation of malignant jaundice due to extrahepatic cholangiocarcinoma, 60 patients were enrolled in a prospective and randomized study. In half of the patients a bare Wallstent was used, and in the other half a Viabil biliary stent. Patients were followed up until death. Primary patency, survival, complication rates, and mean cost were calculated in both groups. Stent dysfunction occurred in 9 (30%) patients in the bare stent group after a mean period of 133.1 days and in 4 (13.3%) patients in the covered stent group after a mean of 179.5 days. The incidence of stent dysfunction was significantly lower in the covered stent group (P = 0.046). Tumor ingrowth occurred exclusively in the bare stent group (P = 0.007). Median survival was 180.5 days for the Wallstent and 243.5 days for the Viabil group (P = 0.039). Complications and mean cost were similar in the two groups. Viabil ...

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Polysaccharides like cellulose and chitosan are known for their filmic properties. This paper concerns the synthesis and the study of chitosan-based polymer electrolytes. A preliminary work concerns the study of glucosamine reactivity. The poly-condensation of chitosan ethers (obtained by reaction with ethylene oxide or propylene oxide) with bifunctional and monofunctional oligo-ethers leads to the formation of thin lattices (10 {mu}m) having excellent mechanical properties. The presence of grafted polyether chains along the polysaccharide skeleton allows to modify the vitreous transition temperature and the molecular disorder of the system. Two type of polymer electrolytes have been synthesized: electrolytes carrying a dissolved alkaline metal salt and ionomers. The analysis of their thermal, dynamical mechanical, nuclear magnetic relaxation, electrical, and electrochemical properties shows that this new class of polymer electrolytes has the same performances as ...

International Nuclear Information System (INIS)

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the cervicothoracic region, where it is usually difficult to obtain clear cervicothoracic films in conventional radiography. We can obtain much precise information about the spinal posterior osteophytes ...

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To evaluate the effectiveness of percutaneous transluminal angioplasty(PTA) and to determine the factors affecting the long-term patency rate in the management of insufficient hemodialytic arteriovenous fistula(AVF). Forty-nine cases of insufficient hemodialytic AVF were treated in 44 patients(native AVF:20, graft AVF:29, M:17, F:27, Age:22-70 years). In 28 thrombus patients, thrombolysis was performed with urokinase, and was followed by PTA. The initial success rate and complications of PTA were evaluated. According to the site and length of the stenosis, type and age of the AVF, the presence or abscence of thrombus, a history of diabetic mellitus, the patient's age, and the duration of renal failure, patency rates were compared within each subgroup using the Kaplan-Meier logrank test. The initial success rate of PTA for insufficient hemodialytic AVF was 88%(43/49), the patency rate of PTA was 67% at 6 months, and 50% at 12 months. The initial success ...

International Nuclear Information System (INIS)

Computerized Tomography has gained an important role in the diagnosis of the complications of prosthetic surgery of the abdominal aorta: the importance of such complications come from their frequency, which is proportional to the increasing number of interventions, and their severity. The authors investigated the CT patterns of the most frequent complications. 24 patients referred for strongly suspected postoperative complications were examined in 2 years: fever and leukocytosis (20 cases) and progressive anemia (4 cases) were the most frequent findings. The operation had been performed 7#+-# 12 weeks before (2 patients were excluded because surgery dated less than 3 weeks. 14 patients had infective complications: thickening (57%) and inhomogeneity (43%) of the periprosthetic wrap and ectopic gas bubble (78%) were the most frequent Computerized Tomography findings. The authors also observed 2 periprosthetic hematomas, 1 aneurysm relapse and 1 prosthetic graft ...

International Nuclear Information System (INIS)

Comprehensive investigation has been made into the application of the polymerization hardening by radiation, particularly electron beam, to the composites of polymers and other materials. The report is divided into four parts, namely 1) characteristics and problems of the reaction of curing by radiation polymerization, 2) improvement of the bonding capability of high molecular weight materials, 3) bonding by radiation, and 4) composites made by the impregnation and polymerization hardening of monomers. The first part includes the effects of dose rate, temperature rise during the hardening, the peculiarity of electron beam irradiation at high dose rate, reaction environment and additive effects. Main conclusions are as follows: caution must be taken to the amount of residual double bonds because they affect the quality of hardened polymers; the polymerization hardening reaction at high dose rate cannot be analogized by that at low dose rate; and the presence of the inhibitors of radical ...

International Nuclear Information System (INIS)

Background: Some former retrospective studies have suggested that patients with Ewing's sarcoma might have a very high risk for developing secondary sarcomas if treated with radiotherapy. We have evaluated the risk of second malignancies (SM) in patients treated in the German Cooperative Ewing's Sarcoma Studies CESS 81 and CESS 86. Materials and methods: From January 1981 through June 1991, a total number of 674 patients was registered in the two multicentric Ewing's sarcoma trials CESS 81 (1981 through 1985) and CESS 86 (1986 through June 1991). The systemic treatment consisted in both studies of a four-drug-chemotherapy (VACA= vincristine, actinomycin D, cyclophosphamide and adriamycin; or VAIA= vincristine, actinomycin D, ifosfamide and adriamycin) and a total number of four courses, each lasting nine weeks, was recommended by the protocol. Local therapy was either complete surgery or surgery plus postoperative radiotherapy with 36-46Gy or definitive radiotherapy with 46 to 60Gy. ...

International Nuclear Information System (INIS)

There are very different views on the health hazards of DU munitions. Most of the concerns of veterans and their advisors focus on the radiological effects of DU and consequently these are the focus of this editorial. Effects on the kidney and environmental consequences are, however, considered in the second of the Royal Society reports and the main conclusions of both of the reports are outlined in the summary document published in this issue of the journal. The main radiological concerns focus on the irradiation of lung tissues from inhaled DU particles and irradiation resulting from the translocation of inhaled particles to the thoracic lymph nodes.The overwhelming scientific view, presented in the two Royal Society reports and in other independent reviews, is that the main risks of exposure to DU aerosols are an increase in lung cancer and (from chemical toxicity) damage to the kidney, although these are likely to be evident only following substantial intakes. The equivalent doses ...

International Nuclear Information System (INIS)

In areas where radiation dose monitoring has not been performed, it is essential to use material available in the environment be able to rapidly assess doses to individuals for immediate emergency medical care or for general estimation of the radiological consequences. It was shown that certain types of telephone cards containing microchips have the potential to be used as individual radiation dosimeters in emergency situations to detect doses over 250 mGy by luminescence measurements. In order to understand the dosimetric properties of chip cards, the components obtained from INFINIEON Company at various stages of production were used for luminescence measurements. It is found that the protecting layer used above the chips so called 'globe top' is the main source of radiation induced signal in chip cards. The globe top produced by INFINIEON at that stage is found to contain SiO2 and Epoxy. In order to improve the dosimetric properties of the ...

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This SBIR Phase I developed neutron detectors made from gallium arsenide (GaAs) p-type/ intrinsic/n-type (P-I-N) diodes grown by metalorganic chemical vapor deposition (MOCVD) onto semi-insulating (S1) bulk GaAs wafers. A layer of isotonically enriched boron-10 evaporated onto the front surface serves to convert incoming neutrons into lithium ions and a 1.47 MeV alpha particle which creates electron-hole pairs that are detected by the GaAs diode. Various thicknesses of ''intrinsic'' (I) undoped GaAs were tested, as was use of a back-surface field (BSF) formed from a layer of Al{sub x}Ga{sub 1-x}As. Schottky-barrier diodes formed from the same structures without the p+ GaAs top layer were tested as a comparison. After mesa etching and application of contacts, devices were tested in visible light before application of the boron coating. Internal quantum efficiency (IQE) of the best diode near the GaAs bandedge is over 90%. The lowest dark current ...

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A semiquantitative assay was developed and used to measure the effects of immune responses against 16 independent non-H-2 antigenic loci on erythropoietic stem cells. The assay compares repopulation in genetically anemic WBB6F1-W/Wv recipients that have normal immune responses, and in lethally irradiated WBB6F1 +/+ mice whose immune responses are suppressed by the irradiation. The differences in repopulating ability between these two types of recipients measure how immune responses affect erythropoietic stem cells. Stem cell repopulating abilities for the cells with antigens specified by the Thy-1, H-1, H-24, Ly-1, H-37, and H-17 loci were affected slightly, if at all. Repopulating abilities were moderately reduced by responses against antigens specified by H-15, 16, Ea-2, and Ly-2, 3 loci, and against the differences between the B6 and B10 genotypes, although marrow of these types cured W/Wv recipients. A surprising result occurred for the antigen specified by the H-8 locus, in which ...

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To evaluate the success rates, long-term patency rates and factors affecting the patency rates of percutaneous transluminal angioplasty(PTA) and thrombolysis in the management of insufficient access during hemodialysis. Between January 1991 and March 1995, 37 insufficient shunts(23 native fistulae and 14 graft fistulae) were treated in 31 patients. PTA was performed in 24 shunts, and thrombolysis in 13;in seven of these latter, thrombolysois was followed by PTA. The success and long-term patency rates of PTA and thrombolysis were evaluated. Shunts were subdivided according to a patient's age, type and age of the shunt, and number and length of the stenosis, and the degree of residual stenosis and in each subgroup, patency rates was compared. The overall success rate of PTA and thrombolysis for insufficient hemodialytic access was 78.4%(29/37). The success rates of PTA and thrombolysis were 91.7%(22/24) and 53.8%(7/13), respectively. The patency rates of ...

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Sufficient genetic diversity exists in Indian tree species to give large genetic gains. Improvement potential, using wild gene resources for selection and breeding is vast as there are over 244 genera and 400 forest tree species in India. Of these over 30 species and 22 genera are of outstanding forestry value. Selective genetic-variation can be lifted from wild populations, multiplied vegetatively or by seed, and planted with controlled germplasm sources. Among the Indian species no less than 74 reproduce by cutting, 11 by layers, 9 by grafting and buding and 104 by root suckers. More than 161 species coppice vigorously. Afforestation techniques of over 170 species have been worked out. Tree genetic approach of survey of natural variability, quick evaluation, selection, conservation multiplication and planting superior variability directly in the field can give immediate genetic gains. This article discusses genetic information on indigenous species for use of ...

Energy Technology Data Exchange (ETDEWEB)

We tested the hypothesis that insulin-dependent diabetic patients with coronary artery bypass graft surgery experience altered coupling of cerebral blood flow and oxygen consumption. In a study of 23 patients (11 diabetics and 12 age-matched controls), cerebral blood flow was measured using 133Xe clearance during nonpulsatile, alpha-stat blood gas managed cardiopulmonary bypass at the conditions of hypothermia and normothermia. In diabetic patients, the cerebral blood flow at 26.6 +/- 2.42 degrees C was 25.3 +/- 14.34 ml/100 g/min and at 36.9 +/- 0.58 degrees C it was 27.3 +/- 7.40 ml/100 g/min (p = NS). The control patients increased cerebral blood flow from 20.7 +/- 6.78 ml/100 g/min at 28.4 +/- 2.81 degrees C to 37.6 +/- 8.81 ml/100 g/min at 36.5 +/- 0.45 degrees C (p less than or equal to 0.005). The oxygen consumption was calculated from jugular bulb effluent and increased from hypothermic values of 0.52 +/- 0.20 ml/100 g/min in diabetics to 1.26 +/- 0.28 ...

Science.gov (United States)

The purpose of this study was to determine the incidence of central vein stenosis and occlusion following upper extremity placement of peripherally inserted central venous catheters(PICCs) and venous ports. One hundred fifty-four patients who underwent venography of the ipsilateral central veins prior to initial and subsequent venous access device insertion were retrospectively identified. All follow-up venograms were interpreted at the time of catheter placement by one interventional radiologist over a 5-year period and compared to the findings on initial venography. For patients with central vein abnormalities, hospital and home infusion service records and radiology reports were reviewed to determine catheter dwelltime and potential alternative etiologies of central vein stenosis or occlusion. The effect of catheter caliber and dwell time on development of central vein abnormalities was evaluated. Venography performed prior to initial catheter placement showed that 150 patients had ...