We irradiated proton beams on the ears of rabbits and the Harding-Passey mouse melanoma and observed their morphological change. We used 52 MeV proton beams from the INS-FM cyclotron. We adjusted the energy of the proton beams to be at the plateau part of the Bragg curve, at the half-way point of the Bragg peak, and at the Bragg peak. The amount of radiation was 5000rad in each case. The Harding-Passey mouse melanoma was transplanted into the subcutan of a three week old mouse. In this experiment, we used tumors, the diameter of which grew up to 1.5-2cm in 2-3 weeks after the transplantation. Using the jroscope, we observed both lightly and severely damaged cells. Using proton irradiation with the Bragg peak located at depth of 1mm in the rabbit's ears, we studied the change in the tissue. Irradiated epidermis fell off and was eroded because of radiation damage, but the rear surface of the ...
Rat lung and liver microsomes did not undergo lipid peroxidation in the absence of iron when incubated with NADPH and concentrations of paraquat ranging from 10/sup -7/ to 10/sup -2/ M. Paraquat also did not stimulate rat liver and lung microsomal peroxidation induced by added iron and NADPH, and was inhibitory at concentrations above 10 ..mu..M. Similarly, no stimulation of peroxidation was produced by paraquat in rabbit or human lung microsomes; however, under similar conditions, paraquat enhanced NADPH/iron-dependent peroxidation in mouse lung and liver microsomes obtained from rats sacrificed at 12, 18, and 24 hr following a lethal dose of paraquat (50 mg/kg, ip), there was no loss of vitamin E or increase in susceptibility to in vitro peroxidation which would be expected if lipid peroxidation had occurred in vivo although extensive lung damage developed during this time period. These results indicate that paraquat does not cause pulmonary ...
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 ...
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 ...
Unlike in normal rabbits, pulmonary rapidly adapting receptors (RARs) in rabbits with chronic mitral regurgitation (MR) do not respond to small changes in extravascular...Full Text Available
BackgroundThe dynorphin-kappa opioid receptor (KOR) system regulates glial proliferation after sciatic nerve injury. Here, we investigated its role in cell proliferation following...Full Text Available
We have developed a new strategy for immunization of wild rabbit populations against myxomatosis and rabbit hemorrhagic disease (RHD) that uses recombinant viruses based on a naturally attenuated field...Full Text Available
To evaluate the effect of plugging the biopsy tract in rabbit liver and the pathologic changes caused by plugging materials. Thirty-two New Zealand White rabbits were divided into four groups (eight rabbits in each) and compared with one another. They were labeled group A (control), B (gelfoam), C (fibrin sealant) or D (NBCA). the liver was exposed and biopsied with an 18G disposable biopsy gun. The inner Tru-cut needle was withdrawn and plugging was undertaken through the outer cannula of the biopsy gun. Bleeding times of each material were compared. The rabbits were sacrificed and pathologically evaluated for 17 days.
The effects of homologous plasma HDL and VHDL fractions on established atherosclerotic lesions were studied in cholesterol-fed rabbits. Atherosclerosis was induced by feeding the animals a 0.5% cholesterol-rich...Full Text Available
The percentages of total airflows over the nasal respiratory and olfactory epithelium of female rabbits were calculated from computational fluid dynamics (CFD) simulations of steady-state inhalation....Full Text Available
The cottontail rabbit papillomavirus (CRPV)/rabbit model has been used to study oncogenicity and immunogenicity of different antigens from the papillomavirus genome and has therefore served...Full Text Available
During the anamnestic response, the sera of four rabbits immunized with a polyvalent pneumococcal vaccine contained large amounts of cryoglobulins belonging to the G and M immunoglobulin classes. These...Full Text Available
The efficacy of beta-lactam antibiotics and amikacin alone and in various combinations against Pseudomonas aeruginosa was studied in a rabbit model simulating a closed-space infection in a locally neutropenic...Full Text Available
The pharmacokinetics of two prodrugs of zidovudine (AZT), 1,4-dihydro-1-methyl-3-[(pyridylcarbonyl)oxy] ester and isoleucinyl ester (DPAZT and IAZT, respectively), were investigated in a rabbit model...Full Text Available
The investigations were conducted at the Center of Biotechnology and Molecular Diagnostics of the All-Russian Animal Husbandry Research Institute, where a number of valuable transgenic animals (rabbits, sheep, and pigs) have been produced over the course of 20 years. The article presents the blood indices of control and transgenic rabbits with an integrated insulin gene.
Understanding the physical characteristics of the local microenvironment in which Mycobacterium tuberculosis resides is an important goal that may allow the targeting of metabolic processes...Full Text Available
The susceptibility of 19 isolates of Haemophilus ducreyi from a recent chancroid outbreak and four reference strains was determined in vitro to 13 antimicrobial agents. The rabbit intradermal...Full Text Available
We have developed a chitosan/polyglycolic acid (PGA) artificial nerve graft which was previously used for bridge implantation of dog sciatic nerves across 30-mm long defects. Here we describe a clinical trial of this graft for repairing a 35-mm-long median nerve defect at elbow of a human patient. During the 3-year follow-up period, functional recovery of the injured median nerve was assessed by pinch gauge test, hydraulic hand dynamometry, static two-point discrimination and touch test with monofilaments, in couple with electrophysiological examinations. The motor and sensory function of the median nerve demonstrated an ongoing recovery postimplantation, reaching M4 and S3+ levels during the follow-up period. The results indicate that the chitosan/PGA artificial nerve graft could be used ...
A case report of falsely elevated serum hormone values measured by radio-immunoassay (RIA) is described. The radio-immunoassays concerned have a first antibody raised in rabbits and mostly a separation technique based on a second antibody-solid phase system. The presence of heterophyle (anti-rabbit) antibodies in patients' serum is proved.
Eight rabbits and 24 guinea-pigs were exposed to a silica dust cloud of about 40,000 pp./ml. (0·3-3·0 μ) and killed at four-weekly intervals up to 30 weeks. The guinea-pigs showed...Full Text Available
The effect of experimental diabetes on the phosphorylation of proteins in the rat sciatic nerve was studied. Nerves from animals made diabetic with streptozocin were incubated in vitro with (/sup 32/P)orthophosphate and divided into segments from the proximal to the distal end, and proteins from each segment were then separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The principal labeled species were the major myelin proteins, P0, and the basic proteins. After 6 wk of diabetes, the incorporation of isotope into these proteins rose as a function of distance along the nerve in a proximal to distal direction and was significantly higher at the distal end compared with incorporation into nerves from age-matched controls. The overall level of isotope uptake was similar in nerves from diabetic animals and weight-matched controls. The distribution of /sup 32/P among proteins also differed in diabetic nerve compared with both control groups in that ...
PurposeWe objectively quantified the gain in urethral diameter and the effect of stenting after tubularized incised plate urethroplasty in a rabbit hypospadias model. Materials and MethodsWe created a hypospadias model in 12 New Zealand white male rabbits by excising the ventral urethra. A 3 cm tattoo line was made longitudinally in the dorsal urethral plate midline. Two weeks later a 2 cm relaxing incision was made in the middle part of the tattooed line. The stretched incision width between the tattooed edges was measured, followed by urethral plate tubularization. Six rabbits were stented and 6 were nonstented. Two weeks later the animals were sacrificed and the distance separating the tattoo was measured at the midpoint of the tattooed line. Transverse sections at this point were exami...
In a series of experiments carried out on young and adult rabbits the effect of isocaloric low protein diets containing 4% or 8% protein compared with a diet containing 21% protein on Obeliscoides cuniculi infection was studied. The pathogenesis, resistance and local immunity were assessed after single infections with 10,000 larvae or reinfection with 5000 larvae. Live weight gain was reduced in young and adult rabbits fed the low protein diets, but the establishment of parasites was not substantially influenced by protein deprivation. However, development of worms in the histotrophic phase and parasite fecundity were impaired in association with the low protein diet. Moreover, mild anaemia as well as changes in the mucosal immune response as a result of infection were related to the level of dietary protein. (author). 30 refs, 6 figs, 5 tabs.
Experiments have been reported previously in which lead-212 ions with lead carrier were instilled into the lungs of anaesthetised rabbits. Experiments were also reported in which bismuth-207 chloride was instilled into rabbit lung. To check that the chloride compound was cleared in the same way as ions instilled in isolation, lead-203 chloride has been instilled in three rabbits. Measurements of absorption of ionic lead have been repeated using the radon-222 daughter, lead-214. Rates of clearance from the lung of "2"0"3Pb as the chloride and "2"1"2Pb ions are compared, and retention functions are derived. Clearance from the lung of "2"1"4Pb ions is also shown, and retention functions are derived. (U.K.).
A comparative and quantitative study of the tissue distribution of brain-thymus shared antigens was carried out using rabbit antisera to rat, dog and human brain homogenates, assayed on rat, dog and...Full Text Available
1. Seven unique carboxymethylcysteine-containing peptides have been isolated from tryptic digests of rabbit muscle aldolase carboxymethylated with iodo[2-14C]acetic acid in 8m-urea....Full Text Available
1. A novel phthalazine analogue taloximine (1-hydroxyimino-4(2-dimethyl-aminoethoxy)-1,2-dihydrophthalazine monohydrochloride monohydrate) stimulated respiration in conscious rabbits at doses of 7...Full Text Available
The pharmacological effects of a series of fatty acid-choline esters have been studied on the isolated rabbit heart, the isolated guinea-pig ileum and the rat stomach. The effect changed with increasing...Full Text Available
A regulatory locus on the Staphylococcus aureus chromosome, designated sar, is involved in the expression of cell wall proteins, some of which are potentially important in the pathogenesis of endocarditis....Full Text Available
Hyaluronan (HA) is important for joint cavitation, lubrication, volume regulation and synovial fluid drainage but little is known about the regulation of joint HA synthesis/secretion in vivo....Full Text Available
... Weiss, S., D. Kobiler, H. Levy, H. Marcus, A. Pass, N. Rothschild, and Z ... of Bacillus anthracis spores conferred by a protective antigen-based vaccine in rabbits ...
Naturally occurring, double-stranded RNA (ds-RNA)) was immunogenic when injected into mice, rats, guinea-pigs, rabbits, dogs and baboons. The response to native material administered intravenously (i.v.)...Full Text Available
An antiserum was raised in a rabbit against highly purified human liver dihydropteridine reductase (EC 1.6.99.7). Dihydropteridine reductase from human liver, in human cultured fibroblasts and in continuous...Full Text Available
Antibodies of the IgM type present in rabbit anti-epiglycanin antiserum were purified by (NH4)2SO4 precipitation and by ion-exchange, affinity and gel-filtration chromatography. After papain treatment...Full Text Available
ABSTRACTObjectivesTo test the feasibility of human immune globulin (IG, Gamimune N, 10%) as a new treatment for endophthalmitis, the ocular tolerance, distribution,...Full Text Available
Orientation and movement relies on both visual and vestibular information mapped in separate coordinate systems. Here, we examine how coordinate systems interact to guide eye movements of rabbits....Full Text Available
... The costal plain still supports Jarrah (Eucalyptus marginata ) forest, dense woodlands, coastal heath and diverse swamplands. Many species of plants are endemic. 20 species of mammals and 12 species of introduced mammals including with feral pigs, rabbits and foxes of particular concern....
1. Gamma globulin metabolism and distribution were studied employing rabbit gamma globulin (RGG)I(131) 24 times in 13 control rabbits. Similar studies were performed before and during the ananmestic response in 4 rabbits previously sensitized with a polyvalent pneumococcal vaccine. 2. During the ananmestic response, gamma-globulin levels increased from 1.0 to 6.0 gm/100 ml, and the gamma-globulin pool increased from 0.7 to 4.7 gm/kg. There was no change in the intravascular-extravascular partition of gamma globulin. 3. Gamma globulin degradation increased from 0.06 to 0.33 gm/kg/day during the 28 days of the immunization period while gamma globulin synthesis increased even further to average 0.47 gm/kg/day. Following the attainment of elevated gamma globulin levels the fractional rate of RGG-I(131) turnover increased from 8.0 to 12.5 per cent/day. 4. No differences were noted in the metabolism of homologous or autologous ...
Assessment of subtle changes in the primary macromolecular components of cartilage, proteoglycan (PG) and collagen, is critical for the diagnosis of early stages of osteoarthritis (OA), but...Full Text Available
Drugs used for the inhibition of DNA viruses, such as iododeoxyuridine, adenine arabinoside, or trifluorothymidine, are not biochemically selective in their action and also interfere with normal cellular...Full Text Available
ObjectivesWe examined the expression of Rho Kinase (ROK) isoforms in young and old rabbit’s detrusor smooth muscles (SM) during the progression of short term...Full Text Available
In vivo, mammalian lenses have the capacity to effect fully reversible changes in shape, and possibly volume, during the accommodation process. Isolated lenses also change shape...Full Text Available
Reaggregated cells from 6- to 8-day-old mouse cerebella have been used to raise antibodies in rabbits. The interaction of these antibodies with cerebellar cell surface components was assessed by cytotoxicity...Full Text Available
Tooth enamel biomineralization is mediated by enamel proteins synthesized by ameloblast cells. Two classes of proteins have been described: enamelins and amelogenins. In lower vertebrates the absence...Full Text Available
Polyclonal antibodies were raised in rabbits by immunization with free peptides corresponding to positions 197-222 of the human beta 1-adrenergic receptor (beta 1 peptide) and the corresponding sequence...Full Text Available
The placental transfer of a single intravenous injection of 14C-hexoprenaline was studied in eight pregnant New Zealand white rabbits. Maternal and fetal blood was sampled intermittently for 60 minutes after the injection. An initial rapid decrease in the levels of 14C-hexoprenaline in maternal blood was followed by a second slower phase, whereas fetal levels remained insignificant. The conclusion, therefore, is that the rapid improvement in fetal heart rate after the administration of a single maternal intravenous injection of hexoprenaline in the treatment of fetal distress is due to the action on the uterus and/or on maternal cardiovascular function, and not to direct stimulation of the fetus.
Objective: To evaluate technical feasibility and acute and subacute radiotolerance of a self-expandable stent loaded with {sup 125}I seeds in the rabbit esophagus. Methods: A self-expandable stent designed for esophageal application was made of 0.16 mm nitinol wire and loaded with {sup 125}I seeds (CIAE-6711). Twenty-seven stents with three different radioactive dosages (n = 9 in each dosage group) were implanted in the esophagus of healthy rabbits, while nine stents alone were used as controls. The stents were perorally deployed into the esophagus under fluoroscopic guidance. Radiological follow-up included plain chest film, CT scan, and barium esophagography which were undertaken in all rabbits of each group at 2, 4, and 8 weeks, respectively, which were correlated to histopathological findings. The stented esophageal segments along with their adjacent tissues were harvested for histopathological examinations. Results: ...
The mortality in undrained abdominal abscesses is high with a mortality rate ranging between 45 and 100%. The outcome in abdominal abscesses, however, has improved due to advances in image guided percutaneous interventional techniques. The main indications for the catheter drainage include treatment or palliation of sepsis associated with an infected fluid collection, and alleviation of the symptoms that may be caused by fluid collections by virtue of their size, like pancreatic pseudocele or lymphocele. The single liver abscesses may be drained with ultrasound guidance only, whereas the multiple abscesses usually require computed tomography (CT) guidance and placement of multiple catheters. The pancreatic abscesses are generally drained routinely and urgently. Non-infected pancreatic pseudocysts may be simply observed unless they are symptomatic or cause problems such as pain or obstruction of the biliary or the gastrointestinal tract. Percutaneous routes that have been described to ...
To assess the technical feasibility of a newly designed stent-like electrode in rabbits. A stent-like electrode was knitted from a single thread of nitinol wire and interconnected to a generator using similar wire. In order to gauge the extent of radiofrequency ablation (RFA), we measured the depth of the ablated area in cow liver using a combination of 180-sec time intervals and 20- watt power increments. For data processing, Cox regression analysis was used. RFA was also applied to the small intestine of rabbits using this stent-like electrode under six different sets of conditions: 10 watts for 1 min, 10 watts for 2 mins, 20 watts for 1 min, 20 watts for 2 mins, 30 watts for 1 min, and 30 watts for 2 mins. To determine the gross and microscopic findings, six animals were sacrificed immediately after the procedure and the results obtained under the different sets of conditions were correlated. Eight rabbits were monitored ...
Threshold pump intensity values leading to irreversible damage to colored laser elements based on elastic polymers were measured. The damage to colored elastomers is connected with absorbing microinclusions but is independent of molecular absorption. It is shown that damage to the elastomers has a pronounced threshold character in contrast to the microdamage accumulation effect in glassy polymers. The damage threshold for elastomers is 1.5 times higher, which is connected with the absence of microstresses (characteristics for organic glasses) in the specimens. 13 references.
Calcitonin gene-related peptide (CGRP) was localized by an immunocytochemical technique in the thyroid-parathyroid complexes of rat, guinea pig, rabbit, and in normal human thyroids and parathyroids. Human medullary carcinomas and parathyroid adenomas were also studied. In man and all animal species examined CGRP was present in the parafollicular cell, however, in guinea pigs only in small amounts. Except in rabbits, presence of CGRP was demonstrated in nerves of the thyroid and parathyroid capsule as well as in the nerve fibers of the capsular blood vessels. In the thyroid of guinea pigs CGRP was also noted in nerve fibers and in blood vessel walls between follicles. CGRP was also present in the parathyroid glands of rat and man, in nerve fibers localized between parathyroid cells. In rabbit the parafollicular cells between parathyroid cells also expressed CGRP immunoreactivity. No CGRP was noted in the parathyroids of the ...
Glycosaminoglycans synthesized by cultured rabbit smooth muscle cells were isolated after incorporation of (/sup 3/H)-glucosamine into glycosaminoglycans in the presence or absence of 10% fetal bovine serum. Glycosaminoglycans were quantitated by two-dimensional electrophoresis after proteolytic digestion of the cell layers and media. The results show that the presence of serum has no effect on the chondroitin sulfate, heparan sulfate and dermatan sulfate content of the cell layers. The incorporation of (/sup 3/H)-glucosamine into hyaluronic acid of the cell layers was three times higher in the presence of serum. In the medium , the quantity of hyaluronic was two times higher in the presence of serum while the other glycosaminoglycans remained unchanged. The incorporation of (/sup 3/H)-glucosamine into hyaluronic acid was unaffected by the presence of serum. Specific proteoglycans were isolated from medium after with (/sup 35/S)-sulfate and (/sup 3/H)-serine by ...
A multifunctional protein kinase, purified from rat liver as ATP-citrate lyase kinase, has been identified as a glycogen synthase kinase. This kinase catalyzed incorporation of up to 1.5 mol of and)2numberSPO4/mol of synthase subunit associated with a decrease in the glycogen synthase activity ratio from 0.85 to a value of 0.15. Approximately 65-70% of the TUPO4 was incorporated into site 3 and 30-35% into site 2 as determined by reverse phase high performance liquid chromatography. This multifunctional kinase was distinguished from glycogen synthase kinase-3 on the basis of nucleotide and protein substrate specificities. Since the phosphate contents in glycogen synthase of sites 3 and 2 are altered in diabetes and by insulin administration, the possible involvement of the multifunctional kinase was explored. Glycogen synthase purified from diabetic rabbits was phosphorylated in vitro by this multifunctional kinase at only 10% of the rate compared to synthase ...
Purpose: The lifelong persistence of foreign bodies within the arteries may contribute to restenosis. Thus,biodegradable devices might decrease recurrence rates. Methods: Eleven polyhydroxybutyrate biodegradable stents and 13 tantalum stents were implanted into the iliac arteries of New Zealand white rabbits for up to 30 weeks. After killing the animals,the specimens were harvested, fixed in formalin, processed in paraffin,and stained. Results: Polyhydroxybutyrate instigated intense inflammatory and proliferative reactions with an increase in collagen (2.4- to 8-fold vs native segments), thrombosis and in-stentlumen narrowing (375.5-606.6 mm vs 655.6 #+-# 268.8 mm in native segments). The elastic membranes were destroyed in all specimens. The tantalum stents increased the in-stent lumen progressively (769.7 #+-# 366.6 mm vs 1309.9 #+-# 695.3 mm),penetrated the external elastic membrane, and increased mural collagen content (6- to 8.6-fold vs native segments). ...
Abstract Purpose: We investigated the effects of various rinsing and healing protocols on corneal wound repair and inflammation following alkali burn in rabbits. Methods: We conducted in vitro, in vivo and ex vivo studies. First, different rinse solutions were tested in vitro after incubation of ocular cells with methanol or NaOH. Cell viability was then assessed using the neutral red test (cytofluorometry). Second, NaOH was applied to rabbit corneas and associations of rinse solutions (NaCl 0.9% or controlled ionization marine solutions) with N-acetylcysteine or vegetable oils (from Calophyllum inophyllum and Aleurites moluccana) were tested in vivo. The regeneration of the corneal epithelium and the infiltration of inflammatory cells were evaluated using in vivo confocal microscopy and e...
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...
Purpose: To evaluate the therapeutic effect of heated (60 deg. C) lipiodol via hepatic artery administration in a rabbit model of VX2 liver cancer. Materials and methods: Thirty male New Zealand white rabbits were randomly divided into three groups with 10 rabbits assigned to each group. VX2 carcinoma cells were surgically implanted into the left hepatic lobe. The tumors were allowed to grow for 2 weeks, and studies were performed until the diameter of the tumors detected by ultrasonograph reached 2-3 cm. Under anesthesia, trans-catheter hepatic arterial embolization was performed and doxorubicin-lipiodol (37 deg. C) (1 mL), lipiodol (60 deg. C) (1 mL) or control (physiological saline (37 deg. C) (1 mL)) solution was injected into the hepatic arteries of animals in the three groups. One week later, the volume of the tumor was measured by ultrasonograph again. The serum of all rabbits was collected ...
Aim: This study was performed: 1) to assess the relationship between blood flow velocity in the internal carotid artery (CBFICA) and pial artery pulsation (cc-TQ) and 2) to evaluate flow-induced changes in pial artery compliance. Methods: Experiments were performed on 10 crossbred male rabbits. Heart rate (HR), blood pressure (BP), left ventricle ejection fraction (LVEF), CBFICA, the systolic-diastolic blood volume fraction in the brain circulation (CBFSDF) and cc-TQ were recorded after glucagon and acetazolamide administration. cc-TQ was measured with near-infrared transillumination back scattering sounding (NIR-T/BSS), LVEF and CBFSDF with gated scintigraphy and BP and CBFICA with electromagnetic pressure and flow transducers, respectively. Doses of drugs were chosen to exert a haemodyna...
Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by...Full Text Available
DNA damage is a threat to genomic integrity in all living organisms. Plants and green algae are particularly susceptible to DNA damage especially that caused by UV light, due to their light dependency...Full Text Available
The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both...Full Text Available
... The revised work plan emphasized the research priorities of preharvest rodent damage to rice, the importance of postharvest food losses to rodents ...
Wade. Jackson. - Army. VTD at NASA. Langley. ABSTRACT. Panel size has a large effect on the impact response and resultant damage level of honeycomb sandwich ...
PurposeCataracts are often considered to be an unavoidable consequence of aging. Oxidative damage is a major cause or consequence of cortical and nuclear cataracts, the most common...Full Text Available
Uteroglobin (UG) gene encodes a cytokine-like, multifunctional, antiinflammatory protein, with potent phospholipase A2-inhibitory activity. It has been suggested that during implantation this protein...Full Text Available
... The dawn of Bio-Mecha and a Biomechanical Revolution May 31 2011: Hi Julian, Yes, but i dont think we would ... The dawn of Bio-Mecha and a Biomechanical Revolution May 31 2011: A BBC Documentary: All Watched Over by Machines of Loving ... The dawn of Bio-Mecha and a Biomechanical Revolution May 17 2011: Ed Boyden: A light switch for neurons is an amazing ... The dawn of Bio-Mecha and a Biomechanical Revolution May 16 2011: Thank you Meher Like Spring Rabbit, its a great contribution....
The use of tick vaccines in mammalian hosts has been shown to be the most promising alternative tick control method to current use of acaricides, which suffers from a number of limitations. However,...Full Text Available
BackgroundHerpes simplex virus type-1 (HSV-1) infections can cause a number of diseases ranging from simple cold sores to dangerous keratitis and lethal encephalitis. The interaction...Full Text Available
Correlates between immunological parameters and protection against Bacillus anthracis infection in animals vaccinated with protective antigen (PA)-based vaccines could provide surrogate markers to evaluate the putative protective efficiency of immunization in humans. In previous studies we demonstrated that neutralizing antibody levels serve as correlates for protection in guinea pigs (S. Reuveny et al., Infect. Immun. 69:2888-2893, 2001; H. Marcus et al., Infect. Immun. 72:3471-3477, 2004). In this study we evaluated similar correlates for protection by active and passive immunization of New Zealand White rabbits. Full immunization and partial immunization were achieved by single and multiple injections of standard and diluted doses of a PA-based vaccine. Passive immunization was carried out by injection of immune sera from rabbits vaccinated with PA-based vaccine prior to challenge with B. anthracis spores. Immunized ...
An analogue of hGH isolated from plerocercoids of the tapeworm Spirometra mansonoides displaces ["1"2"5I]hGH from its receptors in rabbit, rat, and hamster liver membranes. Biologically, plerocercoid growth factor (PGF) is more similar to hGH than to other mammalian GH's but has not been shown to bond human cells. Receptors specific for hGH have been described on cultured human lymphocytes (IM-9). In this study, the authors compared the binding of PGF and hGH in IM-9 cells and in rabbit hepatic membranes. IM-9 lymphocytes (12 x 10"6 cells/tube) were incubated with ["1"2"5I]hGH and increasing concentrations of hGH (ng/ml) or PGF (serial dilutions) for 90 min at 30"0 C. Specific binding (B_0 - NSB) was determined for each dose of hGH or PGF and the binding curves were analyzed by logit-log regression. The results show that PGF displaced ["1"2"5I]hGH from human cells in a dose dependent manner (r = 0.98). Based on the IM-9 assay, 1 ml of the PGF ...
1. Amino acid sequences covering the region between residues 173 and 248 [adopting the numbering system proposed by Lai, Nakai & Chang (1974) Science 183, 1204-1206] were derived for trout (Salmo...Full Text Available
The author furnishes a review of incidents of major damage to high-output steam turbines. At the same time, he thereby underlines the call for an improvement in the exchange of experience on such damage and its causes at international level. Only the careful observance of past damage experience - including that of foreign manufacturers and operators - complete and modern monitoring equipment and the painstaking evaluation of all data furnished by such equipment can keep the risk of new technical development within economically tolerable limits. (orig.).
..cap alpha..-2 adrenergic agents have been shown to influence blood pressure, heart rate and other physiological and behavioral functions through interactions with adrenergic pathways within the central nervous system. Pharmacologically relevant ..cap alpha..-1 adrenergic receptors were biochemically characterized and radiohistochemically analyzed in intact tissue sections of the rat and human central nervous system. The anatomical distribution of the ..cap alpha..-2 receptors, labeled with the agonist (/sup 3/H)para-aminoclonidine, verified the concept that ..cap alpha..-2 receptors are closely associated with adrenergic nerve terminals and that ..cap alpha..-2 agents can influence autonomic and endocrine function through an action in the central nervous system. Since ..cap alpha..-2 agonists can influence sympathetic outflow, ..cap alpha..-2 binding sites were closely analyzed in the intermediolateral cell column of the thoracic spinal cord. The transport of putative presynaptic ...
These studies were undertaken to assess the effects of increased galactose (v increased glucose) metabolism via the polyol pathway on vascular filtration function in the kidneys, eyes, nerves, and aorta. Quantitative radiolabeled tracer techniques were used to assess glomerular filtration rate (GFR) and regional tissue vascular clearance of plasma 131I-bovine serum albumin (BSA) in five groups of male Sprague-Dawley rats: nondiabetic controls, streptozotocin-diabetic rats, nondiabetic rats fed a 50% galactose diet, diabetic rats treated with sorbinil (an aldose reductase inhibitor), and galactose-fed rats treated with sorbinil. Sorbinil was added to the diet to provide a daily dose of approximately .2 mmol/kg body weight. After 2 months of diabetes or galactose ingestion, albumin clearance was increased twofold to fourfold in the eye (anterior uvea, choroid, and retina), sciatic nerve, aorta, and kidney; GFR was increased approximately twofold and urinary excretion ...
We used the tissue distribution of ({sup 14}C)butanol to quantitate regional blood flow in the spinal cord (RSCBF) of pentobarbital-anesthetized, normothermic rats in which segmental local cooling pentobarbital-anesthetized, normothermic rats in which segmental local cooling of the spinal cord (to 25-28{degrees}C) at vertebral levels C4-C6 (n = 6) or T13-L1 (n = 6) was induced. Thirty minutes later, blood flow measurements were made at seven levels of the spinal cord and in the sciatic nerve trunks and biceps femoris muscles. Sham-cooled rats served as controls (n = 12). In control rats, RSCBF varied between 41.5 +/- 2.4 and 65.1 +/- 3.2 ml.min-1.100 g-1. Local cooling of the C4-C6 cord segment reduced RSCBF by 32%, from 65.1 +/- 3.2 to 44.4 +/- 3.5 ml.min-1.100 g-1 (P less than 0.01). Tissue vascular resistance (R) in the cooled C4-C6 segment was elevated versus control. There were no other changes in RSCBF at the other cord levels or in the cauda equina. ...
We have investigated tailoring damage effects of explosive devices by addition of unconventional materials, specifically combustible metals. Initial small-scale as well as full-scale testing has been performed. The explosives functioned to disperse and ignite these materials. Incendiary, enhanced-blast, and fragment-damage effect have been identified. These types of effects can be used to extend the damage done to hardened facilities. In other cases it is desirable to disable the target with minimal collateral damage. Use of unconventional materials allows the capability to tailor the damage and effects of explosive devices for these and other applications. Current work includes testing of an incendiary warhead for a penetrator.
The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific differences in cell sensitivities to DNA-damaging agents in polychaete worms, aimed at increasing fundamental knowledge of their responses to genotoxic damage. The sensitivities of coelomocytes from three polychaetes species of high ecological relevance, i.e. the lugworm Arenicola marina, the harbour ragworm Nereis diversicolor and the king ragworm Nereis virens to genotoxic damage are compared, and dif...
A statistical evaluation of rotor blade damage in axial steam turbines affords an insight into the extent of the repair costs incurred and reveals the types of defects and shortcomings which cause such damage. The great amount of rotor blade damage discovered during control inspections will surprise even many turbine experts. The statistical evaluation is followed by a review of the more frequent causes of damage and their characteristic features, illustrated on the basis of practical examples. This contribution is intended as an aid to both the manufacturers and operators of steam turbines in preventing the oft almost classic types of faults which constantly recur. (orig.).
An investigation was made of the accumulation of laser damage to transparent polymers irradiated with nanosecond pulses from neodymium and ruby lasers. The damage was investigated by the method of scattering and luminescence in the visible and near ultraviolet parts of the spectrum. It was established that there were two stages in laser damage by repeated irradiation with pulses of intensity below the single-shot damage threshold. An absorbing defect evolved during the first stage in such a way as to create a thermal instability in the surrounding matrix. During the second stage this thermal instability caused spatial growth of laser damage because of propagation of an ionization-inducing absorption wave with a front traveling at the rate governed by the electron component of the thermal conductivity.
The authors used radioligand binding and studies of cell contraction to characterize muscarinic receptors on dispersed smooth muscle cells from rabbit proximal and distal colon. Cells obtained after serial incubations in collagenase were used to measure binding of tritiated quinuclidinyl benzilate (["3H]QNB). At 37 degree C, specific ["3H]QNB binding was saturable and linearly related to cell number. Nonlinear regression analysis was used to determine the affinity of ["3H]QNB for its receptor. The IC_5_0 for the muscarinic agonists bethanechol and oxotremorine were 80 and 0.57 #mu#M, respectively. Hill coefficients were 0.67 for both, suggesting more complex interaction involving receptors of different affinities. In studies of cell contraction, bethanechol stimulated a dose-dependent decrease in cell length with half the maximal contraction occurring at 100 pM. These results suggest that (1) contraction is mediated by binding of bethanechol to M_2-muscarinic ...
Hyaluronan is an important constituent of the extracellular matrix in skin, and recent studies suggest that there is a pool of easily removable (free) hyaluronan drained by lymph. The removal rate of free hyaluronan in skin was measured from the elimination of ({sup 3}H)hyaluronan, injected subcutaneously in 13 rabbits. The removal of radioactivity was determined from appearance of {sup 3}H in plasma. During the first 24 h after injection, 10-87% of the tracer entered blood, less in injectates with high concentrations of hyaluronan. The removal was monoexponential with a half-life of 0.5-1 day when concentration of hyaluronan was 5 mg/ml or less. When hyaluronan concentration was 10 mg/ml or higher, the removal was slow for about 24 h and then became similar to that in experiments with low hyaluronan concentration. Free hyaluronan at physiological concentrations is thus turned over with the same rate as serum albumin, supporting the concept that hyaluronan is ...
A new /sup 99m/Tc-phosphine-isocyanide complex with the general structure (/sup 99m/Tc (DEPE)/sub 2/(CNR)/sub 2/)/sup +/ has been synthesised and tested in animals and one human. In three animal species (rat, rabbit, dog), the complex is an efficient myocardial imaging agent, while in humans it remains in the blood pool. The complex is 100% protein bound in animals and humans, but whereas in humans it is attached to a 51.5 kdalton protein (probably prealbumin), in rabbits it appears to be bound to a larger macromolecule (M.W.>100 kdalton). The efficiency of the complex for blood pool labelling was tested in a human volunteer and compared with the standard in vivo red cell labelling technique with stannous pyrophosphate. A satisfactory radionuclide angiogram could be performed with less than 370 MBq of the complex. The count rate for the complex (cps/MBq) was 15% higher than that obtained with the labelled red cells and the absence of splenic ...
The placental transfer of a single intravenous injection of 14C-hexoprenaline was studied in eight pregnant New Zealand white rabbits. Maternal and fetal blood was sampled intermittently for 60 minutes after the injection. An initial rapid decrease in the levels of 14C-hexoprenaline in maternal blood was followed by a second slower phase, whereas fetal levels remained insignificant. The conclusion, therefore, is that the rapid improvement in fetal heart rate after the administration of a single maternal intravenous injection of hexoprenaline in the treatment of fetal distress is due to the action on the uterus and/or on maternal cardiovascular function, and not to direct stimulation of the fetus.
Central penetrating excisional wounds were made in the corneas of 12 rabbits and 10 trout. The scar tissue and the surrounding cornea were compared using a new method for assessing inorganic elements in the cornea: the scanning electron microscopy and energy dispersive analysis of x-ray (EDAX). Semiquantitative determination of inorganic elements within the range of atomic numbers 9-93 in the periodic system was performed, comparing the relative concentration of those elements in the scar tissue to the surrounding cornea. Results showed that calcium was the only element higher in the healing wound than in the surrounding cornea.
In this paper a new procedure, addressed as Interpolation Damage Detecting Method (IDDM), is investigated as a possible mean for early detection and location of light damage in a structure struck by an earthquake. Damage is defined in terms of the accuracy of a spline function in interpolating the operational mode shapes (ODS) of the structure. At a certain location a decrease (statistically meaningful) of accuracy, with respect to a reference configuration, points out a localized variation of the operational shapes thus revealing the existence of damage. In this paper, the proposed method is applied to a numerical model of a multistory frame, simulating a damaged condition through a reduction of the story stiffness. Several damage scenarios have been considered and the results indicate the effectiveness of the method to assess and localize ...
The plerocercoid stage of the tapeworm Spirometra mansonoides produces a functional analog of human growth hormone (hGH). Among the similarities between plerocercoid growth factor (PGF) and hGH is competition for the same receptors on rabbit liver membranes. To take advantage of this characteristic in a purification scheme for PGF, rabbit liver microsomes were solubilized in Triton X-100 and the hGH receptors were purified over an hGH affinity column. The purified receptors from six rabbit livers were coupled to Affi-Gel-10 to create a receptor affinity column which was used to purify PGF. Chromatography of crude PGF over the receptor column resulted in a 1044 fold increase in specific activity. SDS-PAGE in the presence of 2-mercaptoethanol showed that the affinity-purified PGF contained three protein bands with apparent Mrs of 27.5 K, 22 K, and 16.7 K. Injections of the partially-purified PGF into hypophysectomized rats ...
A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) and phosgene (COCl/sub 2/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation toxicity studies. The effect of 4-h exposures to ozone at concentrations of 0.2, 0.5, 1.0, and 2.0 ppm, and to COCl/sub 2/ and 0.1, 0.2, 0.5, and 1.0 ppm was determined in rabbits, guinea pigs, rats, hamsters, and mice. Lavage fluid protein (LFP) accumulation 18-20 h after exposure was used as the indicator of O3- and COCl/sub 2/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 mg/ml) when a volume of saline that approximated the total lung capacity was used to lavage the collapsed lungs. Ozone effects were most marked in guinea pigs, which showed significant effects at 0.2 ppm and above. Mice, hamsters, and rats showed effects at 1.0 ppm O3 and above, while rabbits responded ...
BackgroundWe examined the effects of short-term consumption of whey protein isolate on muscle proteins and force recovery after eccentrically-induced muscle damage in healthy individuals.MethodsSeventeen...Full Text Available
The regular occurrence of large-scale earthquakes in Japan necessitates the use of earthquake disaster prevention systems that focus on gathering damage information on gas supply facilities immediately after an earthquake strikes and minimizing the damage. This paper discussed the development of an earthquake damage estimation system for city gas pipelines that can show damage information in real-time by using earthquake records obtained from densely deployed earthquake observation networks and the most advanced telecommunication and information technologies. The paper summarized the earthquake damage estimation system (EDES) and Toho Gas disaster prevention measures. Specific topics that were discussed included the Toho Gas supply method; earthquake countermeasures; construction of computer systems; normal and emergency operation of EDES; and verification of functions in actual ...
Service, Alaska Regional Office Prince William Sound, photo: Mandy Lindeberg Office of Exxon Valdez Oil Spill (EVOS) Damage Assessment and Restoration About NOAA Fisheries' EVOS...
Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity....Full Text Available
One of the most pervasive ideas regarding the causes of aging is that longevity is constrained in large measure by damage to macromolecules. An increasing body of cellular and molecular data, generated...Full Text Available
This book contains over 20 selections. Some of the titles are: Continuum damage mechanics studies on the dynamic fracture of concrete; Dynamic compressive strength of cementitious materials; Rate-sensitivity of mode I and mode II fracture concrete; and An impact damage model of concrete.
A compensatory response, viz. in vivo recovery from radiation damage to mitochondria, occurs in preclimacteric pear fruits (Pyrus communis L.) treated with ionizing...Full Text Available
The annealing behavior of the radiation damage in epitaxial Pd_2Si and NiSi_2 films on Si, due to the implantation of 100 keV Ar ions, is investigated by using the channeling technique with "4He ions. (U.K.).
A novel acidizing process is used to increase the permeability of carbonate rock cores in the laboratory and to remove drilling fluid damage from cores and wafers. Field results show the benefits of the technology as applied both to injector and producer wells.
Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.
In order to investigate the influence of grain boundary cavities on the life time of Alloy 800 H various fatigue tests have been performed at 800/sup 0/C. Cavity formation has been observed only in asymmetrical tests. Compared to the corresponding symmetrical tests, the cyclic life time is shorter. As the cavitation damage increases, the ratio of life times in vacuum and in air steadily decreases from an initial value of 5. In extreme cases it can reach a value close to 1. In this case, cavitation damage dominates over the usual damage mechanism, which is cracks from the surface.
It is possible to create nomographs similar to Fig. 2.10 to characterise damage potential of candidate time histories, provided there exists extensive records of earlier time-histories and the damage that they have caused. Thus in order to create such nomographs, one needs the correlated documentation between the input to the structure and the resulting damage. In order to use the Response-Spectra approach, one needs good statistical description of the input to the system. Extensive literature exists on both these methods. The MAC method that has being developed for the present research has yet to be validated. However, if it is successful, it would provide a valuable link between the SEA method and the rational method.
A simple method allowing easy calculation of the spatial damage energy distributions for ion-implanted materials is presented. The direct procedure takes account of the variation with depth of the lateral spreading of implanted ions, as well as the effects of energy transport by the recoiling target atoms. The subsequent computer program LUPIN-3D provides three-dimensional damage distributions and allows the construction of damage energy mappings. Various substrates of technological interest are investigated and several fields of application of the calculation are envisaged. The density of cascades can therefore be determined and heterogeneous amorphization models can be implemented. (orig.).
External radiation dose exceeded 5,000 rad in three cases, and intravaginal radiation dose was 5,000 rad in one case. Radiation damage including perforation was seen in the end of ileus in one case, in the sigmoid and rectum in two cases, and in the end of ileus, sigmoid and rectum in the last case. Satisfactory results were obtained by the removal of the ileocecum in the case of the damage in the end of the ileus. However, only colostomy was performed for the damage in the sigmoid and rectum.
Analysis of damages done by the radiation in a polymer characterized by optic properties of polished surfaces, of uniformity and chemical resistance that the acrylic; resistant until the 150 centigrade grades of temperature, and with an approximate weight of half of the glass. An objective of this work is the development of a method that analyze in automated form the superficial damages induced by radiation in plastic materials means an images analyst. (Author)
Because the bridges over the Rio Grande were to be razed, the investigators were able to introduce simulated cracks in four stages of increasing length into the structure. This paper summarizes the results of ambient and conventional, measured-input, modal analyses, performed on the undamaged structure. Also summarized are the results of conventional modal analyses performed after each stage of damage had been introduced. These tests were intended to quantify the amount of damage necessary to produce changes in the global dynamic properties of the bridge and to form a data base that can be used by other investigators to develop damage identification algorithms. Conventional modal analysis identified changes in the global dynamic properties of the structure only after the final stage of a damage.
EXAFS measurements are useful in determining the local atomic environment of a particular element in a solid. Since there has been some controversy about the nature of the defects produced in A-15 materials by radiation damage, such studies were carried out on some A-15 compounds, V_3Ga which was damaged by neutrons, as well as Nb_3Ge damaged by 2.5 MeV a particles. In the V_3Ga sample, site exchange disorder seems to be the most important result of the neutron damage with less than 20% of the vanadium atoms on wrong sites. However, in the Nb_3Ge samples in addition to site exchange disorder, an unusual splitting of the first near-neighbor distance between the Ge and Nb is found. This splitting, approximately 0.2 A, may explain the large Debye Waller factors observed by Burbank et al.
Summary Status epilepticus or other brain-damaging insults launch a cascade of events that may lead to the development of epilepsy. MRI techniques available today, including T2- and T1-weighted imaging, functional MRI, manganese enhanced MRI (MEMRI), arterial spin labeling (ASL), diffusion tensor imaging (DTI), and phase imaging, can detect not only damage caused by status epilepticus but also plastic changes in the brain that occur in response to damage. Optimal balance between damage and recovery processes is a key for planning possible treatments, and noninvasive imaging has the potential to greatly facilitate this process and to make personalized treatment plans possible.
Initial rates of resistivity-measured low-temperature damage production by fission-spectrum fast neutrons have been determined for 14 metals in the same very well characterized irradiation facility. Six of these metals were fcc, 5 bcc, and 3 hcp. Most were of quite high purity. Observed damage rates, after correction for all known extraneous resistivity-producing effects, were compared with rates predicted by the damage calculation code RECOIL, using parameters chosen from the literature. These parameters, effective displacement threshold energy, E/sub d/, and Frenkel-pair resistivity, rho/sub F/, were in many cases only best estimates, the further refinement of which may be aided by the present results. Damage efficiencies (measured/predicted rates) follow the same trends by crystal classes as seen in other fast-neutron studies.
This paper focuses on a factorial-based design strategy. The approach provides an efficient and statistically reliable means for assessing the influence of multivariable effects. It is applied to the detection and evaluation of damage in impacted composite sandwich panels. The experimental results obtained from this test strategy are utilized to form an empirical response function. The resulting polynomial relates damage area to residual compression strength at values of independent variables for which testing did not occur. The response function also identifies nonlinear interaction effects of key variabes that cannot be easily ascertained by traditional single-variable test strategies. Independent variables evaluated include core thickness, number of face sheet plys and impact energy. The methodology presented allows the designer to predict with more confidence the damage tolerance of a composite material component, and ...
The topics of these short lectures on the subject of cyclic stress were: Microstructural mechanisms of damage accumulation under a multistage cyclic stress until incipient cracking; influence of surface decarbonizing phenomena on the failure behaviour of steel construction parts subjected to cyclic stress; thermocyclic fatigue of pipe samples of austenitic steel 1.4436; studies on surface structuring, microstructure and fatigue in LCF area. The short lectures on effects of quasi-static and creep stress were: Shear fracture in AlMg alloys as a result of local plastic instability; study of formation and growth of pores for an early recognition of damage and the course of damage in heat-resistant steels under creep test; experimental and numeric studies of the infuence of the microstructure on the course of damage during shear fractures of steel; numerical modelling of ductile fractures on the basis of ...
The DNA double-strand break (DSB) damage response induced by high energy charged particles on lung fibroblast cells embedded in a 3-dimensional (3-D) collagen tissue equivalents was investigated using antibodies to the DNA damage response proteins gamma-histone 2AX (#gamma#-H2AX) and phosphorylated DNA-PKcs (p-DNA-PKcs). 3-D tissue equivalents were irradiated in positions across the linear distribution of the Bragg curve profiles of 307.7 MeV/nucleon, 556.9 MeV/nucleon, or 967.0 MeV/nucleon "5"6Fe ions at a dose of 0.30 Gy. Patterns of discrete DNA damage streaks across nuclei or saturated nuclear damage were observed, with saturated nuclear damage being more predominant as samples were positioned closer to the physical Bragg peak. Quantification of the DNA damage signal intensities at each distance for each of the examined energies revealed a biological Bragg ...
A 19.1 metre wind turbine blade was subjected to static tests. The purpose of the test series was to verify the abilities of different types of sensors to detect damage in wind turbine blades. Prior to each of the static test-series an artificial damage was made on the blade. The damage made for each test-series was surveyed during each series by acoustic emission, fiber optic micro bend displacement transducers and strain gauges. The propagation of the damage was determined by use of ultra sonic and X-ray surveillance during stops in the test series. By use of acoustic emission it was possible to measure damage propagation before the propagation was of visible size. By use of fiber optic micro bend displacement transducers and strain gauges it was possible to measure minor damage propagation. By use of both ultra sonic, and X-ray NDT-equipment it were possible ...
A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF{sub 2}, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In ...
A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF_2, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, ...
This study describes the chemical composition of the essential oil of Artemisia maritima (Am.Oil) and the pharmacological basis for its medicinal use in gut and airways disorders. Twenty five compounds, composing 93.7% of the oil, were identified; among these, chrysanthenyl propionate and elixene were identified for the first time from any Artemisia species. The Am.Oil (0.3?1.0 mg/mL) suppressed spontaneous and high K+ (80 mM)-induced contractions in isolated rabbit jejunum, suggestive of an antispasmodic effect mediated possibly through calcium channel blockade. The calcium channel blockade activity was confirmed when pre-treatment of the tissue with Am.Oil (0.01?0.03 mg/mL) shifted the Ca++ concentration-response curves to the right, similar to verapamil and papaverine. In isolated trach...
It was developed a new formulation of macro aggregates of Samarium 153 ({sup 153} Sm-MH) for the arthropaties treatment. The radio pharmaceutic was prepared by reaction of Samarium 153 chloride (SmCl{sub 3}) in aqueous environment with sodium boron hydride in NaOH 0.5 N. The microscopic analysis shown that the particles have an average size of 4% m (range 1-14 {mu} m). The velocity of sedimentation was 0.008 cm/min with high stability in vitro in human serum. The biological studies in healthy rabbits, shown that the complex is retained inside the articulation still eight days after of the administration of the radiopharmaceutical. Likewise, it is presented the data of absorbed dose in the different target organs, which was determined by thermoluminescent dosimetry (TLD) through the use of a REMCAL phantom (radiation equivalent manikin calibration). (Author)
Neutron energy spectra were measured for two OSURR experimental facilities. The method of multiple foil activation was used with the SAND-II neutron spectrum unfolding code to obtain spectral data for the Central Irradiation Facility and Rabbit tube. Limited data was obtained for the thermal column using only gold foils. Calculations were made of the neutron environment in various locations using the MORSE code. A shift towards higher neutron energies was observed comparing results for LEU and HEU cores. A slight loss in total thermal neutron flux was measured for all positions. Calculational results show reasonable agreement with measured data.
Aim:To examine the electrophysiological effects of sophocarpine on action potentials (AP) and ionic currents of cardiac myocytes and to compare some of these effects with those of amiodarone.Methods:Langendorff perfusion set-up was used in isolated guinea pig heart, and responses to sophocarpine were monitored using electrocardiograph. Conventional microelectrode, voltage clamp technique and perforated patch were employed to record fast response AP (fAP), slow response AP (sAP) and ionic currents in guinea pig papillary muscle or rabbit sinus node cells.Results:Tachyarrhythmia produced by isoprenaline (15 ?mol/L) could be reversed by sophocarpine (300 ?mol/L). Sophocarpine (10 ?mol/L) decreased the amplitude by 4.0%, maximal depolarization velocity (Vmax) of the fAP by 24.4%...
Two lines of mouse tumor cells were shown to be capable of aggregating mouse and rabbit platelets in vitro. This process required higher Mg/sup 2 +/ concentrations than were needed by other commonly used platelet-aggregating agents. Platelet-aggregating activity was also found in tumor cell membrane fragments. This membrane-bound platelet-aggregating material contained protein, lipid, and carbohydrate moieties. The presence of all three appeared to be essential for stimulating platelet aggregation. Destruction of any component abolished its activity. Platelet aggregation induced by tumor cell membrane fragments was associated with a secretory release reaction. In this process, growth-promoting activity for tumor cells was also released from platelets. These results underline the importance of platelets in establishing tumor metastases.
In FY1994, JMTR was in operation during 4 operation cycles with low enriched Uranium(LEU,20%) fuel for irradiation study of nuclear fuels and materials and for radioisotope production. Irradiation studies were carried out using capsules, Oarai Gas Loop-1(OGL-1), Oarai Shroud Facility(OSF-1) and hydraulic rabbits irradiation facilities in support of LWR, FBR, HTTR and thermonuclear reactor. Irradiation studies on blanket materials were intensively carried out. Power ramping tests were carried out and the future program is under consideration. For R and D works, neutron spectrum evaluation technology, re-instrumentation technique for irradiation fuel rod, remote controlled SEM apparatus and examination technique with miniaturized specimens were successfully developed. (author).
Techniques of chemical analysis, amino acid sequencing and autoradiography are being used to study the frequency of incorporation of normally noncoded amino acids into hemoglobins and seminal fluid proteins. We are studying, by the sequencing of radiolabeled proteins followed by the recovery of ["3H] isoleucine phenylthiohydantoin by high-performance liquid chromatography, the frequency at which normally noncoded isoleucine is incorporated into hemoglobin because of base-substitution mutations versus translational errors. Irradiation increases the isoleucine content of human hemoglobin and the frequency of substitution of isoleucine for specific amino acids in rabbit hemoglobin. Studies to date indicate that these techniques have been developed sufficiently for initial analysis of the potential of drugs and environmental pollutants to induce base-substitution mutations in mammalian somatic cells.
Transparency is essential for normal corneal function. Recent studies suggest that corneal cells express high levels of so-called corneal crystallins, such as aldehyde dehydrogenase (ALDH) and transketolase (TKT) that contribute to maintaining cellular transparency. Stromal injury leads to the appearance of repair phenotype keratocytes, the corneal fibroblast and myofibroblast. Previous studies on keratocytes from species such as bovine and rabbit indicate that the transformation from the normal to repair phenotype is accompanied by a loss of corneal crystallin expression, which may be associated with loss of cellular transparency. Here we investigated if a similar loss occurs with human keratocyte repair phenotypes. Human corneal epithelial cells were collected by scraping and keratocytes...
We describe a model of damage in rf cavities and show how this damage can limit cavity operation. We first present a review of mechanisms that may or may not affect the ultimate fields that can be obtained in rf cavities, assuming that mechanical stress explains the triggers of rf breakdown events. We present a method of quantifying the surface damage caused by breakdown events in terms of the spectrum of field enhancement factors, Beta, for asperities on the surface. We then model an equilibrium that can develop between damage and conditioning effects, and show how this equilibrium can determine cavity performance and show experimental evidence for this mechanism. We define three functions that quantify damage, and explain how the parameters that determine this performance can be factored out and measured. We then show how this model can quantitatively explain the dependence of ...
The examples quoted show that damage is mostly due to faults of design and construction or faulty operation. The ever shorter development cycles, the further development of existing constructions and cost pressure owing to price slumps are very important in this context. Careful endoscopic inspections and monitoring and early identification of beginning damage helps to prevent major damage and follow-up damage. The causes of changing operational performance must be established as early as possible to prevent larger damages from being caused by continued operations.(orig.) [German] Die vorgestellten Schadenbeispiele zeigen, dass die Schaeden vorwiegend durch Auslegungsfehler und Konstruktionsfehler aber auch durch Bedienungsfehler verursacht wurden. Die immer kuerzeren Entwicklungszeiten fuer Neukonstruktionen und die Weiterentwicklung vorhandener Konstruktionen sowie der Kostendruck ...
Displacements per atom (DPA) is a widely used damage unit for displacement damage in nuclear materials. Calculating the DPA for SiC irradiated in a particular facility requires a knowledge of the neutron spectrum as well as specific information about displacement damage in that material. In recent years significant improvements in displacement damage information for SiC have been generated, especially the energy required to displace an atom in an irradiation event and the models used to describe electronic and nuclear stopping. Using this information, numerical solutions for the displacement functions in SiC have been determined from coupled integro-differential equations for displacements in polyatomic materials and applied in calculations of spectral-averaged displacement cross sections for SiC. This procedure has been used to generate spectrally averaged displacement cross sections for SiC in a ...
Displacements per atom (DPA) is a widely used damage unit for displacement damage in nuclear materials. Calculating the DPA for SiC irradiated in a particular facility requires a knowledge of the neutron spectrum as well as specific information about displacement damage in that material. In recent years significant improvements in displacement damage information for SiC have been generated, especially the energy required to displace an atom in an irradiation event and the models used to describe electronic and nuclear stopping. Using this information, numerical solutions for the displacement functions in SiC have been determined from coupled integro-differential equations for displacements in polyatomic materials and applied in calculations of spectral-averaged displacement cross sections for SiC. This procedure has been used to generate spectrally averaged displacement cross sections for SiC in a ...
In acute intoxication, uranium (U) not only inhibits bone formation but its excretion in urine also causes renal damage. The former effect is ameliorated by tetracycline (TC), probably due to its chelation property, which might also prevent U deposition in bone. Chemical determination of U incorporated in bone and a histological study of the kidneys were performed on animals injected with U and then treated with TC. The results showed that TC was unable to prevent the binding of U to bone while it exacerbated U-induced renal damage.
Numerical simulation of dynamic fracture of concrete slabs, impacted by steel projectiles, was carried out in this study. The concrete response was described by a continuum damage model. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study with an emphasis on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code LS-DYNA2D and the code was then used for the numerical simulations. The specific impact configuration of this study follows the experiment series conducted by Hanchak et al. Comparisons between calculated results and measured data were made. Good agreements were found.
The influence of material configuration and impact parameters on the damage tolerance characteristics of sandwich composites comprised of carbon-epoxy woven fabric facesheets and Nomex honeycomb cores was investigated using empirically based response surfaces. A series of carefully selected tests were used to isolate the coupled influence of various combinations of the number of facesheet plies, core density, core thickness, impact energy, impactor diameter, and impact velocity on the damage formation and residual strength degradation due to normal impact. The ranges of selected material parameters were typical of those found in common aircraft applications. The diameter of the planar damage area associated with Through Transmission Ultrasonic C-scan measurements and the peak residual facesheet indentation depth were used to describe the extent of internal and detectable surface damage, respectively. ...
Apparent growth of amorphous layers during low temperature annealing was observed in low energy Ge{sup +}-implanted (0 0 1)Si by high-resolution transmission electron microscopy. The occurrence of abnormal growth is due to the randomization of heavily damaged regions beneath the original amorphous/crystalline interfaces. The randomization process is attributed to the strain, incurred by the presence of a high density of large Ge atoms in the heavily damaged Si substrate, relaxation to lower the free energy of the systems. The randomization upon annealing may be fruitfully applied to minimize the transient enhanced diffusion in shallow junction formation.
Apparent growth of amorphous layers during low temperature annealing was observed in low energy Ge"+-implanted (0 0 1)Si by high-resolution transmission electron microscopy. The occurrence of abnormal growth is due to the randomization of heavily damaged regions beneath the original amorphous/crystalline interfaces. The randomization process is attributed to the strain, incurred by the presence of a high density of large Ge atoms in the heavily damaged Si substrate, relaxation to lower the free energy of the systems. The randomization upon annealing may be fruitfully applied to minimize the transient enhanced diffusion in shallow junction formation.
This text-book (electronic book - multi-media CD-ROM) constitutes a course-book - author's collection of lectures. It consists of 13 lectures in which the reader acquaints with the basis of radiobiology: Introduction to radiobiology; Physical fundamentals of radiobiology; Radiation of cells; Modification of radiation damage of cells; Reparation of radiation damage of cells; Radiation syndromes and their modification; Radiation injury; Radiation damage of tissues; Effect of radiation on embryo and fetus; Biological effects of incorporated radionuclides; Therapy of acute irradiation sickness; Delayed consequences of irradiation; Radiation oncology and radiotherapy. This course-book may be interesting for students, post-graduate students of chemistry, biology, physics, medicine as well as for teachers, scientific workers and physicians. (author)
This paper describes examples of the damage resulting from the impact of a whipping pipe on a nearby pressurised pipe. The work is a by-product of a study of the motion of a whipping pipe. The tests were conducted with small-diameter pipes mounted in rigid supports and hence the results are not directly applicable to large-scale plant applications where flexible support mountings are employed. The results illustrate the influence of whipping pipe energy, impact position and support type on the damage sustained by the target pipe.
This paper describes examples of the damage resulting from the impact of a whipping pipe on a nearby pressurised pipe. The work is a by-product of a study of the motion of a whipping pipe. The tests were conducted with small-diameter pipes mounted in rigid supports and hence the results are not directly applicable to large-scale plant applications where flexible support mountings are employed. The results illustrate the influence of whipping pipe energy, impact position and support type on the damage sustained by the target pipe. (author).
Theoretical analysis, modeling, and simulation are used to provide insight into the development of permeability during thermal damage of the high explosive PBX 9501. In a recently published article, Terrones et al. [1] conclude that samples of PBX 9501 thermally damaged at 186 degreeC are not permeable to gas flow in a manner consistent with Darcys Law. We disagree with their conclusion. We show that they have misreported data from the literature, and that their argument depends on a fluid flow model that is physically incorrect and is applied with inappropriate physical parameters.
The author discusses in detail the following topics: Compensation for domestic nuclear damage and for transfrontier nuclear damage - rule of formal equality of parties which belongs to the basic rule of civil law considering the position of domestic and foreign victims of a grave accident-juridical consequences of the preponderant role played by the state in the promotion, development and supervision of the nuclear industry-rationale for applying the concept of global limitation of liability in the law on nuclear liability and compensation - financial consequences of uncompensated nuclear damage, borne by the victims directly affected or spread over the whole community of the affected state? (HP)
Despite a complex cascade of cellular events to reconstruct the damaged extracellular matrix, ligament healing results in a mechanically inferior scarred ligament. During normal healing, granulation...Full Text Available
Species invasions are a principal component of global change, causing large losses in biodiversity as well as economic damage. Invasion theory attempts to understand and predict invasion success and...Full Text Available
Elaboration of a Modern Technology for Operational Agrometeorological Soil Moisture Monitoring Spring Wheat, Yield and Disease Damage Forecasting and Recommendations for Plant Protection on the Kazakhstan Territory
Senescence is regarded as a physiological response of cells to stress, including telomere dysfunction, aberrant oncogenic activation, DNA damage, and oxidative stress. This stress response has an antagonistically...Full Text Available
The purpose of the recommendation is to prevent, to detect, and to remove soiling of guide and retrating blades of steam turbines, e.g. on account of foreign matter in steam dissolved. (TK/LN).
The kinetic energy transferred to some elements by an electron of kinetic energy 100 to 400 kV is discussed. The displacement rates are compared to the signal generation. (DCL)
Description: Hurricane Hugo, which struck South Carolina in September of 1989, destroyed a significant proportion of the State's timber. Primary wood-products ...
Rheumatoid arthritis (RA) is a debilitating autoimmune disease of global prevalence. The disease is characterized by synovial inflammation leading to cartilage and bone damage. Most of the conventional...Full Text Available
BackgroundAlterations in protein composition and oxidative damage of high-density lipoprotein (HDL) have been proposed to impair the cardioprotective properties of...Full Text Available
Shadow effect was used for investigating damage of uranium dioxide monocrystal. The dependence of shadow minimum parameters on fluence of "2"2Ne ions with 172 MeV energy was followed when detecting fission fragments. Ion dose responsible for sufficient microdamage of lattice structure, included into the classification of heavy ion damage effect on monocrystals was determined. The problem of radiation intensity effect on the character of occurred damages was studied. It was established that macroscopic sample failure, caused by generation of considerable mechanical stresses in monocrystal under beam effect could be observed along with microdamages of lattice structure at ion flux density >10"1"2 cm"-"2Xs"-"1.
The cost incurred every year in West Germany due to air pollution is investigated. Damage to buildings, materials, and vegetation are evaluated as well as the cost of additional cleaning work and changes of location with the objective of getting a picture of the economic value of air pollution abatement. The findings are based on data of immission damage in high-exposure areas. Damage is assessed in consideration of the frequency of repair measures in industrial and country atmosphere. Further research will be necessary in view of the many problems concerning methods and availability of basic statistical data. The sequential cost estimated for a few selected cases of damage show that economic losses due to air pollution amount to several thousand million DM. Air pollution abatement measures thus do not only improve our quality of life but also help to save considerable cost to our national economy.
The objectives of the Phase-I research address the development of mechanics- based structural integrity analysis methodologies for composite sandwich panels ...
Physiological bone remodeling is a highly coordinated process responsible for bone resorption and formation and is necessary to repair damaged bone and to maintain mineral homeostasis. In addition to...Full Text Available
In this study, we measured the effects of different concentrations of paraquat (0,01 mM and 1,0 mM) on the 1-"1"4CO_2 and 6-"1"4CO_2 production of rabbit lung slices and isolated alveolar macrophages, in 20% and 95% oxygen phases respectively. A 95% oxygen phase induced an increase in the 6-"1"4C-glucose oxidation of control lung slices over a 3-hour period, while the increased activity of the pentose pathway over the first 2 hours started to decline during the third hour of incubation. Paraquat (1,0mM) in 20% oxygen caused a consistent increase in the 6-"1"4CO_2 production by lung slices, but in a 95% oxygen phase gradually inhibited the 6-"1"4C-glucose oxidation over a period of 3 hours. The pentose phosphate pathway was highly significantly stimulated by 1,0 mM paraquat in 20% and 95% oxygen over 3 hours. When isolated alveolar macrophages (viability 95%) were incubated in a 20% and 95% oxygen phase respectively, both the 6-"1"4C-glucose and 1-"1"4C-glucose ...
A portion of the active site of rabbit skeletal myosin near the ribose ring of ATP can be labeled by the photoaffinity analogue 3{prime}(2{prime})-O-(4-benzoylbenzoyl)adenosine triphosphate (Bz{sub 2}ATP). The specificity of the photolabeling was assured by first trapping ({sup 14}C)Bz{sub 2}ATP at the active site by use of thiol cross-linking agents. Five radioactive peptides were isolated by high-performance liquid chromatography after extensive trypsin and subtilisin digestion of photolabeled myosin subfragment 1. Four of these peptides were sequenced by Edman techniques, and all originated from a region with the sequence Gly-Glu-Ile-Thr-Val-Pro-Ser-Ile-Asp-Asp-Gln, which corresponds to rabbit myosin heavy chain residues 312-328. The fifth labeled peptide had an amino acid composition appropriate for residues 312-328. Amino acid composition, radiochemical analysis, and sequence data indicate that Ser-324 is the major amino acid residue ...
Aldosterone has been suggested to elicit vessel contraction via a nongenomic mechanism. We tested this proposal in microdissected, perfused rabbit renal afferent arterioles. Aldosterone had no effect on internal diameter in concentrations from 10(-10) to 10(-5) mol/L, but aldosterone abolished the ability of 100 mmol/L KCl to induce vascular contraction. The inhibitory effect of aldosterone was observed from 1 pmol/L. The inhibitory effect was significant after 5 minutes and maximal after 20 minutes and was fully reversible. Actinomycin D (10(-6) mol/L) prolonged the effect of aldosterone. The effect was abolished by the mineralocorticoid receptor antagonist spironolactone (10(-7) mol/L) but not by the glucocorticoid receptor antagonist mifepristone (10(-6) mol/L). The K+-mediated increase of intracellular calcium concentration in afferent arterioles was not affected by aldosterone. Mineralocorticoid receptor was detected by reverse transcription-polymerase chain ...
The authors have shown previously that the domain recognizing receptors on activated human platelets is located on the human fibrinogen {gamma} chain between residues 400 and 411. To study the correlation between the structure of this segment of the {gamma} chain and its reactivity toward receptors on ADP-activated human platelets, they designed a series of analogues containing replacements at 9 out of 12 positions. A double substitution of the normal His{sup 400}-His{sup 401} sequence by Ala-Ala reduced the inhibitory potency of the dodecapeptide 3-fold. When Lys{sup 406} was replaced by Arg, the inhibitory potency of the dodecapeptide decreased 15 times. On the other hand, substitution of Ala{sup 408} with Arg increased the inhibitory potency of the dodecapeptide 6-fold. A drastic decrease in the reactivity of the dodecapeptide toward platelet receptors was observed when Val{sup 411} was replaced by leucine or cysteine or tyrosine. A 3-fold decrease in reactivity was noted when ...
(Materials and Methods) (I) VX/sub 2/ carcinoma was transplanted to the rabbit tibia, sup(99m)Tc-MDP was intravenously injected when bone destruction was radiologically seen. Preoperative scintigraphs, postoperative one of the resected tibia and fibra and scintigraphs of sliced tumor were compared with each other. Tissue fragments were collected from the sliced tumor, and RI was measured to compare concentration rates at different parts together with histological investigations. (II) Tetracycline was given to the rabbit of Experiment (I) to compare with the concentration of sup(99m)Tc-MDP. (III) Microautoradiography method was done on the experimental animals for investigation of the concentration of sup(99m)Tc-MDP. (Results) (I) Localization of sup(99m)Tc-MDP was increased at the sites of tumorous bone formation, of reactive bone formation at tumor edges, and of cartilage calcification, with little concentration at tumor cells or necrotic ...
Tc-MDP 10mCi was intravenously given preoperatively to 20 patients with primary bone tumors and 1 with a metastatic bone tumor. Preoperative and postoperative scintigraphs of resected tumor and scintigraphs of sliced tumor were compared. Tissue fragments were collected from the sliced tumor, and RI measured to compare concentration rates at different areas. Histological investigations were also done. Localization of Tc-MDP was increased at sites of tumorous bone formation, of reactive bone formation at tumor edges, and of cartilage calcification, with little concentration at tumor cells or necrotic tissue. VX/sub 2/ carcinoma was transplanted into the rabbit tibia, Tc-MDP was intravenously injected when bone destruction was radiologically evident, and investigations were done as in the clinical cases. In experimental bone tumor, increased uptake localization of Tc-MDP was much the same as in clinical cases. Tetracycline was given to the rabbit ...
Previous in vitro studies have demonstrated that Ho:YLF laser is capable of inducing physical and chemical changes on dental surfaces treated for caries prevention. The temperature in the pulp chamber was in vitro evaluated to as a function of the power and frequency of the laser irradiation. The purpose of this work is to verify the occurrence of pulp inflammation after Ho:YLF laser irradiation using different parameters in rabbits' teeth. The premolars and molars of ten rabbits (NZB) were divided in two groups according to the irradiation energy values of a Ho:YLF laser prototype operating at 2.065{mu}m wave length, frequency of O,5Hz and pulse length of 250{mu}s. An group A teeth were irradiated with using ten pulses of 334mJ/pulse of a Ho:YLF laser prototype operating at O.5Hz, and group B, with 512mJ/pulse. Animals were killed by transcardiac perfusion and the samples were prepared for histopathological analysis. The in vitro ...
In 65 adult rabbits of both sexes (2.5 to 6 kg) the following salvaging procedures were performed after simulated trauma: (1) Continuous suture line; (2) closure with fibrin sealant after temporary clamping; (3) hemisplenectomy with omental wrap; (4) suture fixation of fragments and slices of spleen tissue to the peritoneum; (5) suture fixation of spleen fragments to the omentum; (6) extraperitoneal subcutaneous transposition of spleen cubes. In addition, the likelihood of spontaneous splenosis was examined in a preliminary study involving 5 animals by introducing unattached spleen meal and fragments. Scanning was repeated 4 to 12 weeks postoperatively. The functional competence of minor parenchymal islands was also investigated with well counter measurements of organ and muscle tissue homogenates. Spontaneous splenosis after abdominal injuries was not found to be the rule. Salvaging procedures at the natural vascular hilus by sutures, fibrin sealant and ...
The affinity label 8-((4-bromo-2,3-dioxobutyl)thio)adenosine 5{prime}-triphosphate (8-BDB-TA-5{prime}-TP) reacts covalently with rabbit muscle pyruvate kinase, incorporating 2 mol of reagent/mol of enzyme subunit upon complete inactivation. Protection against inactivation is provided by phosphoenolpyruvate, K{sup +}, and Mn{sup 2+} and only 1 mol of reagent/mol of subunit is incorporated. The authors have now identified the resultant modified residues. After reaction with 8-BDB-TA-5{prime}-TP at pH 7.0, modified enzyme was incubated with ({sup 3}H)NaBH{sub 4} to reduce the carbonyl groups of enzyme-bound 8-BDB-TA-5{prime}-TP and to introduce a radioactive tracer into the modified residues. Following carboxymethylation and digestion with trypsin, the radioactive peptides were separated on a phenylboronate agarose column followed by reverse-phase high-performance liquid chromatography in 0.1% trifluoroacetic acid with an acetonitrile gradient. Gas-phase sequencing ...
We have done analysis of elements in the Baltic sea sediment by using gamma spectrometry in neutron activation analysis Goal of the analysis is to determine the rate of morsel elements which is contained in the Baltic sea sediment. Sample of the Baltic sea Sediment (IAEA-SED-1), Standard of Reference Material (SRM) 1646 Estuarine Sediment and Standard Ce, Fe, Sc, and Co are put into vial of capsule rabbit, then irradiated together for 30 minutes in rabbit facility Multi Purpose Reactor at power of 25 MW and then cooled for one week. Next sample, standard, and SRM which have irradiated, each is cut for 30 minutes using gamma spectrometer. Result of analysis of rate of elements Ce, Fe, Sc and Co in the baltic sea sediment successively equal to 141.20 ppm, 5.91 %, 14.88 ppm, and 19.59 ppm. Result of analysis in SRM Estuarine sediment successively equal to 96.60 ppm, 3.21 %, 10.25 ppm, and 9.63 ppm. Result of this analysis if compared to the value ...
Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross section transmission microscopy (XTEM) as ...
There is a lot of interest in the studies that would help to understand whether there is a casual association between cancer and various types of molecular or cytogenetic damage detected in human cells. One major oncogenesis process is activation of proto-oncogenes by point mutations or chromosomal translocation. There are substantial evidence that indicates that the loss of heterozygosity of certain chromosomes is involved in human cancerogenesis. Our study aimed to elicit the possible association between cancer and DNA and cytogenetic abnormalities induced in lymphocytes of people bearing various categories of skin cancer cells. Fresh blood was collected by venipuncture from 25 individuals (including nine prior to cancer treatment). All patients were nonsmoking males, however 42.3 % of them were former smokers. Blood samples were divided into two parts and in the first part of samples cytogenetic studies were performed immediately, while from the second part ...
Although the p53 tumor suppressor is relatively well characterized, much less is known about the functions of other members of the p53 family, p73 and p63. Here, we present evidence that in specific pathological conditions caused by exposure of normal cells to bile acids in acidic conditions, p73 protein plays the predominant role in the DNA damage response. These pathological conditions frequently occur during gastric reflux in the human esophagus and are associated with progression to esophageal adenocarcinoma. We found that despite strong DNA damage induced by bile acid exposure, only p73 (but not p53 and p63) is selectively activated in a c-Abl kinase-dependent manner. The activated p73 protein induces DNA damage repair. Using a human DNA repair PCR array, we identified multiple DNA repair genes affected by p73. Two glycosylases involved in base excision repair, SMUG1 and MUTYH, were characterized and found to be ...
BackgroundThe Mre11/Rad50/Nbs1 (MRN) complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged....Full Text Available
A simple model is used to explain the decrease in superconducting critical temperature with damage observed for irradiated A-15 compounds. A truncated t-matrix approximation is used to describe the disorder along the one-dimensional transition metal chains. Three dimensionality is introduced by the inclusion of interaction between transition metal atoms on different chains. Numerical fits to experiment are discussed in the conclusion. (author).
The resistance to microbe damages of aqueous solutions of cutting fluids (SOZh), which contain dual and more complex mixtures of known compounds, is studied. Lauric acid, myristic and tridecanic acid give microbic resistance to the compositions of synthetic cutting fluids. A complexing of the compositions as a rule does not support precisely expressed effects of synergism or antagonism.
Full text: It is known that the ion implantation of germanium single crystals at room temperature results in drastic alteration of the germanium surface and the formation of cellular relief. Voids were found into the near-surface damage layer. The intersection of these voids with the germanium surface, as result of sputter etching, forms cellular relief. However, exact mechanism responsible for formation of the voids is not known. A 10 and 30 keV Ga"+ irradiation of Ge #left brace#100#right brace# crystal at room temperature was carried out using a focused ion beam (FIB) system with a dose in the range 0.5x10"1"2 to 1.5x10"1"4 ion/cm"2. The topology of the modified germanium surface and the structure of the radiation damage was studied using imaging facilities of the FIB systems and transmission electron microscopy. The strong cellular structure of Ge was observed after an ion dose of 3x10"1"3 ion/cm"2. High-resolution TEM showed a complex ...
Allianz Global Corporate and Specialty AG, the industrial insurance carriers of Allianz Group and AZT Risk and Technology GmbH, have a lot of experience and a comprehensive database about damage of industrial steam turbines and large-scale power generation turbosets. Sound maintenance concepts are the main loss prevention measure, which will be presented and discussed in detail. Some modifications and additions to existing maintenance concepts are also provided.
Blades of modern steam turbines are designed for high efficiency and operational safety. Modern computer programs enable optimisation of design but factors like manufacturing, assembly, operation and downtimes still play an important role. Damage statistics show that blade damage still quite frequent. Selected cases from the Allianz damage assessment centre show some of the more frequent damage mechanisms. Damage is often caused when several factors come together. Prevention of follow-up damage requires early identification of beginning damage.(orig.) [German] Die Auslegung der Beschaufelung moderner Dampfturbinen hat die Vorgabe, einen hohen Wirkungsgrad bei gleichzeitig hoher Betriebssicherheit zu erreichen. Mit den heute zur Verfuegung stehenden Rechenprogrammen ist eine entsprechende Optimierung realisierbar. Fuer die langzeitige ...
This paper dealt with the identification of possible damaging mechanism of the collector of the WWER 440 steam generator, cracking of primary collectors, corrosion damage of the protective coat of the primary collector circumferential weld, cracking of breathing space in the region of blinding effect by corrosion and strain, leaking of disassembling joint of the primary collector lid and with the integrity of heat exchanging tubes.
The histone chaperone Asf1 and the chromatin remodeler SWI/SNF have been separately implicated in derepression of the DNA damage response (DDR) genes in yeast cells treated with genotoxins that cause...Full Text Available
Possible causes of forest damage are discussed. Mapping of affected areas by various workers resulted in dissimilar pictures. Release of radioactive rare gases, aerosols, tritium and carbon-14 seems unlikely to have a significant influence on forest damage. Influence of radioactive fallout, ozone formation by high-voltage transmission lines and synergistic effects is also found to be negligible.
From the frequency of diagnostic radiologic examinations and their radiation dose delivered to the population the risk of cancer induction and genetic damage is calculated on the basis of the risk factors given by the ICRP. Thus 0.38 % and 3 % of the total mortality for cancer and leukemia, resp., can be attributed to X-ray diagnostics. Chest examinations alone result in 0.07-0.7 damages per 100,000 persons depending on the imaging technique applied. (author).
Substantial damages at main components of steam turbines do not have to result inevitably in an exchange of the components concerned. Rather a preliminary or final repair is possible which also considers the cause of the damage. An important condition with the technically complex questions is an appropriate qualification and experience of all involved persons. The common task of operators, manufacturers and insurance companies is to preserve the balance from costs, expenditure of time and risk.
sinensis), the otter (Lutra lutra) and the grey seal (Halichoerus grypus) can be mentioned as ...conflict relates to damage caused by the grey seal to coastal fisheries, whereas in Germany damages ...For example species like the grey seal involved in the conflicts may benefit from the by-catch regulation.
Specifications of the PGV-1000 steam generators applied at the WWER-1000 NPP power units, operational experience and data on damages at the 'cold' heat carriers of steam generators are considered and their results are presented. Developed and introduced measures aimed at improving reliability and operational life of the PGV-1000 collectors are described.
This book examines the nonlinear optical properties of laser materials. The physical radiation effects on laser materials are also considered. Topics considered include: nonlinear optical properties; nonlinear and harmonic generation materials; two-photon absorption; nonlinear refractive index; stimulated Raman scattering; radiation damage; crystals; and glasses.
Late somatic and genetic radiation effects are imperfectly understood, particularly in the human species. However the available information is sufficient to draw reasonably precise risk estimates in man for many types of damage by means of scientifically justifiable procedures and with the necessary caution. This overall absolute risk of major somatic and genetic damage may be set at around 10"-"4/rad of chronic whole-body doses.
The overall objective of this project is to produce antibodies to unique modified DNA bases and develop immunochemical assays to quantitate these lesions in damaged DNA. During this past year we have developed an antibody and chemical test to quantitate a basic sites in DNA and produced antibodies to the 8-oxopurines. This report discusses the detection of a basic sites in DNA and the preparation of antibodies to 8-hydroxyadenine and 8-hydroxyguanine.
Surface barrier detectors may be damaged, because of microplasma breakdown, in rapid application of bias voltage. The high performance FETs of very low noise preamplifiers may also be damaged by rapid changes of the bias voltage. The electronic device described permits the gradual application and removal of the bias voltage, without any influence on the power supply specification. (Auth.).
The developed countries are implementing a policy minimizing damage from environmental pollution by reducing discharge in advance as well as the aftermath of a pollutant. The typical example is to use BAT (Best Available Technology). This is to prevent environmental damage by reducing the discharge of pollutants with available technology and to secure environmental margin to enable industrial activities of future generation. Therefore, the feasibility of introducing BAT requirement system was reviewed by considering foreign examples and Korean situation. 38 refs., 8 figs., 69 tabs.
The influence of high temperature thermal ageing treatments on the development of intercrystalline creep damage in two variants of Alloy 800 has been investigated. Ageing up to 3000 h and creep testing were carried out at 800 and 900 C. The high temperature behaviour of the 800HT variant is discussed with reference to the effect of heat treatments on the microstructure. The metallographic methods by which the creep damage was quantitatively determined are described. The growth rate of intercrystalline microcracks was described using a statistical model and the dependence of crack growth rate on the thermal history for both 800HT and 800H was determined. The carbide precipitation and growth processes were determined as functions of the exposure temperature and duration. The results showed the three characteristic stages, precipitation, growth and coarsening (Ostwald ripening). The largest increase in the intergranular creep ...
Commercial focused ion beam (FIB) systems are commonly used to image integrated circuits (ICS) after device processing, especially in failure analysis applications. FIB systems are also often employed to repair faults in metal lines for otherwise functioning ICS, and are being evaluated for applications in film deposition and nanofabrication. A problem that is often seen in FIB imaging and repair is that ICS can be damaged during the exposure process. This can result in degraded response or out-right circuit failure. Because FIB processes typically require the surface of an IC to be exposed to an intense beam of 30--50 keV Ga{sup +} ions, both charging and secondary radiation damage are potential concerns. In previous studies, both types of effects have been suggested as possible causes of device degradation, depending on the type of device examined and/or the bias conditions. Understanding the causes of this damage is ...
It is important for the trauma surgeon to understand the basic principles of terminal gunshot ballistics and the study of the projectile's effect on striking soft tissue. The amount of kinetic energy dissipated to the tissue is directly related to the mass and velocity of the projectile as follows: K = MV2/2. Doubling the velocity quadruples the energy, while doubling the mass only doubles the energy. A temporary tissue cavity is produced as the striking projectile compresses the surrounding tissue; the higher the energy release, the more extensive the inapparent compressive damage. The permanent cavity that remains is the result of extrusion of tissue from the pathway of the projectile. The higher the velocity, the higher the likelihood of extensive damage. If the missile expands or fragments within the tissues, more damage will occur. PMID:6847483
Eugenol, the principal chemical component of clove oil from Eugenia aromatica has been long known for its analgesic, local anesthetic, anti-inflammatory, and antibacterial effects. The interaction of the eugenol with ten different hydrophobic and hydrophilic antibiotics was studied against five different Gram negative bacteria. The MIC of the combination was found to decrease by a factor of 5-1000 with respect to their individual MIC. This synergy is because of the membrane damaging nature of eugenol, where 1mM of its concentration is able to damage nearly 50% of the bacterial membrane. Eugenol was also able to enhance the activities of lysozyme, Triton X-100 and SDS in damaging the bacterial cell membrane. The hydrophilic antibiotics such as vancomycin and b-lactam antibiotics which have ...
Plastic injection molds are an important economic sector due to the increasing use of injection molded plastic components. The selection of mold steel material, its processing conditions, and the way it is machined and hardened all have an impact on how it performs during use across its lifecycle for injection molding. For this study, injection molding conditions seen during high volume manufacturing were used to induce wear that would be typical during processing. A 50wt.% glass fiber reinforced Polybutylene Terephthalate (PBT) was used for the research. After 3000 injection operations, surface damage was found only on the steel used for the stationary half of the mold cavity and the corresponding surface of the molded parts. In contrast, the moving half showed no surface damage or increa...
Scanning spreading resistance microscopy (SSRM) has been applied to study focused ion beam (FIB) induced damage in silicon in dependence on ion irradiation doses from 10"1"2 cm"-"2 to 2#centre dot#10"1"6 cm"-"2. Starting from the lowest dose, SSRM detects increasing spreading resistance (SR) with increasing dose. For doses from 2#centre dot#10"1"3 cm"-"2 to 4#centre dot#10"1"4 cm"-"2, a slight decrease of SR is measured whereas for higher doses SR again slightly increases. The results are explained by physical effects like decreased carrier mobility due to increased scattering, amorphisation of silicon and precipitation of implanted Ga ions. The results clearly prove that SSRM is well suited for the fast detection of ion beam induced damage with high lateral resolution.
Aims: Rapamycin (sirolimus) is an antibiotic that inhibits protein synthesis through mammalian targeting of rapamycin (mTOR) signaling, and is used as an immunosuppressant in the treatment of organ rejection in transplant recipients. Rapamycin confers preconditioning-like protection against ischemic-reperfusion injury in isolated mouse heart cultures. Our aim was to further define the role of rapamycin in intracellular Ca^2^+ homeostasis and to investigate the mechanism by which rapamycin protects cardiomyocytes from hypoxic damage. Main methods: We demonstrate here that rapamycin protects rat heart cultures from hypoxic-reoxygenation (H/R) damage, as revealed by assays of lactate dehydrogenase (LDH) and creatine kinase (CK) leakage to the medium, by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-d...
Nano photonic materials are synthetically manufactured crystals at the nano scale with the target of creating a microstructure with a special electro-magnetic periodicity. Such nano photonic materials have the ability to control light propagation and thus are capable of creating photonic bandgaps in the frequency domain. We propose using nano photonic crystals as sensors to detect microdamage in composite materials. We demonstrate using a simulation model that a nano photonic sensor attached to a composite bar experiences a significant change in its bandgap profile when damage is induced in the composite bar. The model predicts the frequency response of the nano photonic sensor using the transfer matrix method. A damage metric to evaluate the change in the frequency response is developed. Successful developments of nano photonic sensors allow damage identification at scales not attainable using current sensing technologies.
Specimen damage and element loss induced by 3 MeV proton and 2 MeV alpha particle bombardment of thin sections of freeze-dried kidney tissue and embedding medium have been studied. Yields of ions scattered from H and C, and characteristic X-rays were measured versus accumulated charge, for curent densities in the range from 8x10{sup -15} to 1.1x10{sup -11} A/{mu}m{sup 2}. Structural damage, dissolouration and loss of S, Cl, C and H have been observed. Implications of this study for ion beam microanalysis of biological tissues are discussed with particular reference to the results for H loss. (orig.).
Imatran Voima Oy , (IVO) operates two Russian designed nuclear power plants of type VVER440/213. Unit 1 has been operating since 1977 and unit 2 since 1981. First damage of feed water distribution (FWD) pipes was observed in 1989. In closer examinations FWD-pipe T-connection and distribution nozzles suffered from severe erosion corrosion damage. Similar damages have been found also in other VVER-440 type NPPs. In 1994 the first FWD-pipe was replaced by a new design mounted over the tube bundle instead of the old FWD-pipe, which was located inside the tube bundle. The purpose of this paper is to describe the new FWD-pipe and discuss its effects on the steam generator chemistry. (author)
The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10{sup 14} cm{sup -2}) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.
The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10"1"4 cm"-"2) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.
Abstract Background and Purpose: During laser lithotripsy, working instruments are often in close proximity to the distal fiber tip and may be damaged accidentally or even intentionally. The aim of this study was to compare the amount of damage to a standard guidewire and the nitinol wires of endourologic retrieval baskets that were affected by three different clinically available laser systems. Materials and Methods: The impact of pulsed laser irradiation on a standard hydrophilic guidewire and a retrieval basket were investigated. One infrared (IR) laser system (holmium:yttrium-aluminum-garnet [Ho:YAG]: ????=???2100???nm) and two laser systems emitting light in the visible (VIS) spectral range (frequency-doubled double-pulse neodymium:YAG [FREDDY]: ????=???532???nm/1064???nm and flashl...
The detection and characterization of deeply buried fatigue damage in thick, multi-layer airframe components pose significant technical challenges to the aviation safety community. Currently, no nondestructive evaluation technique is available to reliably detect such potential damage from the exterior of the airframe, which is highly desirable in light of inspection cost as well as avoidance of structure damage. Recent technological advances in high-sensitivity magnetic sensors, i.e., spin-dependent tunneling (SDT) sensors, make it feasible to employ electromagnetic inspection techniques for deep fatigue crack inspection. In this work, we report on the development and fabrication of a low frequency eddy current probe based on a magnetically shielded SDT pickup sensor concentrically located...
Phreatic groundwater pumping is affecting water availability for crops in areas with a shallow water table. This can reduce crop growth and so affect farm income. There is a need for a generic and transparent method to assess the agricultural damage caused by water table drawdown. This paper proposes such a method that consists of 'damage tables' relating agricultural production losses to the groundwater regime for different soil/crop combinations found in Northern Belgium. The damage tables are constructed based on numerous simulations with the agrohydrological model SWAP, in which the bottom boundary conditions are gradually changed to reflect different groundwater regimes. The credibility of the resulting metamodel is assessed in three ways: using (1) field data, (2) an existing local e...
In the flood surveys, it is fundamental to set up the relations of stage-damage. And this makes it possible to evaluate the flood regulation effects of the multipurpose dam and/or levee construction for optimum formulation. Unfortunately in the previous basin studies excluding the Han river basin survey, the conventional approaches on this matter have not been performed due to its time-consuming complexity. In this study we attempted a new method based on the disaster status, and constructed six stage-damage curves along the reaches of the Kum river basin, based upon the flood events records for recent 12 years (1981-92). (author). 12 refs., 3 tabs., 13 figs.
Microstructural observations of damage around indentations in Ti{sub 3}SiC{sub 2} are presented. The Vickers hardness decreased with increasing load and asymptotically approached 4 GPa at the highest loads. No indentation cracks were observed even at loads as high as 300 N. Preliminary strength versus indentation plots indicate that, at least for the large-grained material ({approx}100 {micro}m) studied here, Ti{sub 3}SiC{sub 2} is a damage-tolerant material able to contain the extent of microdamage to a small area around the indent. The following multiple energy-absorbing mechanisms have been identified from scanning electron micrographs of areas in the vicinity of the indentation: diffuse microcracking, delamination, crack deflection, grain push-out, grain pull-out, and the buckling of individual grains.
Pro-inflammatory cytokines may directly influence the viability and metabolic function of colonic epithelial cells (CEC) as an early event in the development of inflammatory bowel disease. We report here that TNF-alpha+IFN-gamma induced a synergistic, concentration-dependent decline in butyrate oxidation, an essential energy supply, in HT-29 and DLD-1 cells. TNF-alpha+IFN-gamma induced a parallel profound decline in cell viability in HT-29 cells, but not in DLD-1 cells, where impairment of butyrate oxidation seemed to precede later occurrence of cell damage. TNF-alpha+INF-gamma induced CEC damage was independent on NO formation and involved the IFN-gamma signalling pathway as well as induction of apoptosis. If cytokines have similar effects in vivo, these may lead to energy deficiency and thus contribute to CEC damage and disturbance of the epithelial integrity.
The effects of focused-ion-beam-induced damage on electrical properties of n-type Si are investigated by Schottky contacts. Crystalline Si is exposed to 10-30 keV focused ion beam (FIB), followed by Pt deposition under vacuum of 4x10"-"4 Pa. From current-voltage-temperature measurements, barrier heights of the Schottky contacts are found to increase almost linearly as the FIB energy increases, with the maximum increment of 0.29 eV. The increase is suggested to be related to the arising of acceptorlike defects and an amorphous layer due to FIB damages. A theoretical model is set up to quantitatively describe the barrier height changes.
Channeling effect measurements have been employed to investigate radiation damage produced by 100-keV Ar ions in preferred oriented polycrystalline metal-silicide layers, such as Pd/sub 2/Si and NiSi/sub 2/ layers formed on single-crystalline Si. For room-temperature implantation, an amount of the damage in Pd/sub 2/Si layers was found to saturate at doses between 3 x 10/sup 14/ and 1 x 10/sup 17/ ions/cm/sup 2/, where the minimum aligned yield of 1.5-MeV He ions was nearly 40% of the random one. On the contrary, it was observed that the NiSi/sub 2/ layers became amorphous at doses higher than 3 x 10/sup 15/ ions/cm/sup 2/. These results were confirmed by the reflection electron diffraction analyses.
Channeling effect measurements have been employed to investigate radiation damage produced by 100-keV Ar ions in preferred oriented polycrystalline metal-silicide layers, such as Pd_2Si and NiSi_2 layers formed on single-crystalline Si. For room-temperature implantation, an amount of the damage in Pd_2Si layers was found to saturate at doses between 3 x 10"1"4 and 1 x 10"1"7 ions/cm"2, where the minimum aligned yield of 1.5-MeV He ions was nearly 40% of the random one. On the contrary, it was observed that the NiSi_2 layers became amorphous at doses higher than 3 x 10"1"5 ions/cm"2. These results were confirmed by the reflection electron diffraction analyses.
We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process.
The major degradation mechanisms acting during the aging of selected WWER-440/213 primary circuit facilities were assessed critically. The analysis gave evidence that such mechanisms include radiation and fatigue damage of the reactor pressure vessel (effect of the neutron flow, cyclic fatigue promoted by the corrosive medium, effect of thermal aging), corrosion-mechanical and thermo-mechanical (fatigue) damage of the steam generator (stress corrosion cracking, erosion corrosion, thermal aging, wear), thermal and dynamic aging of the pressurizer, and corrosion-mechanical damage of the primary circuit piping (thermal aging, corrosion). (J.B.). 5 tabs., 1 fig., 62 refs.
"9"9"mTechnetium -heat damaged erythrocyte were used as spleen scanning agents in 12 patients from July, 1985 to April, 1986. We used this scan to evaluate situs inversus, asplenia, accessory spleen, hypersplenism, splenic infarction, tumor staging and evaluation of therapy, especially when the "9"9"mTc-tin colloid scans were not definite for diagnosis. The techniques applied to these scans were in vivo/in vitro-labeling method and heating-method to damage the erythrocytes. Liver-to-spleen uptake ratios were increased upto 100:1 and interference from the left lobe of the liver was eliminated. These scans were helpful to evaluate the spleen. (Author).
Active oxygens produced by low-dose irradiation can induce the synthesis of proteins involved in the active oxygen reduction path and can activate the chemical self-defense mechanisms in vivo, which can alleviate the injuries caused by active oxygens themselves. The following findings suggests that it is not only by low-dose irradiation that can induce the responses described above but also by any physical and/or chemical stresses which can produce small amount of active oxygens in vivo. 1. X-irradiation with 0.5 Gy and/or water immersion and restraint induced heat shock protein (HSP)70 in rat stomach cells. HSP70 was also induced in adrenal cells by paraquat administration. 2. The SOD activity in pancreas of rat significantly increased by #gamma#-irradiation with 0.5 Gy. 0.5 Gy irradiation preceeding the alloxan administration significantly suppressed the increase in pancreatic lipid peroxides and in blood glucose levels, degranulation in #beta# cells, and decrease in blood insulin ...
The effects of 0.2 and 0.5 mL/kg Innovar (a neuroleptic analgesic) on cardiovascular functions and reflexes in rabbits were measured. We recorded the effects of Innovar on arterial pressure, heart rate, respiration rate, ventricular contractility, arterial oxygen tension, as well as the drug's effects on the bradycardia and vasoconstrictor response to cigarette smoke stimulation of the nose (the so-called "nasopharyngeal reflex"). In animals given 0.2 mL/kg Innovar, all steady state cardiovascular variables had returned to pre-Innovar levels in 45 min, as had the efficacy of the nasopharyngeal reflex. In animals given 0.5 mL/kg Innovar, all steady state cardiovascular variables, except PaO2, were slightly but significantly depressed for up to 135 min after injection. The nasopharyngeal reflex returned to normal within 90 min. Because of the calmative and analgesic effects of Innovar, and its only moderate effects on cardiovascular functions and reflexes, we feel it ...
The Ohio State University Research Reactor (OSURR) is licensed to operate at a maximum power level of 500 kW. A pool-type reactor using flat-plate, low enriched fuel elements, the OSURR provides several experimental facilities including two 6-inch i.d. beam ports, a graphite thermal column, several graphite-isotope-irradiation elements, a pneumatic transfer system (Rabbit), various dry tubes, and a Central Irradiation Facility (CIF). The core arrangement and accessibility facilitates research programs involving material activation or core parameter studies. The OSURR control room is large enough to accommodate laboratory groups which can use control instrumentation for monitoring of experiments. The control instrumentation is relatively simple, without a large amount of duplication. This facilitates opportunities for hands-on experience in reactor operation by nuclear engineering students making reactor parameter measurements. For neutron activation analysis and ...
Intramuscular hermorrhage was induced by injecting autologous blood into the paraspinal muscle of 8 rabbits. In order to evaluate the time-dependent changes of hemorrhage observed on MRI, the animals were imaged at different stages of blood resolution at 0.02 tesla (T), and control examined with ultrasound using a 7.5 MHz linear transducer. Six inversion recovery sequences (TR=1 000 ms. TE=30 ms, and TI=18, 48, 148, 201, 302, and 398 ms) were used for the invivo calculation of T1 relaxation times. IR 1 000 (398)/30 imaging was performed before and after the Gd-DOTA administration. The hemorrhage was evident on MR images throughout the study, especially on the T2 weighted (SE 1 000/100) images. MRI showed the healing lesion longer than ultrasound. The T1 relaxation time increased during the time of resolution. Lesions on days 4 to 7 enhanced in intensity after the injection of Gd-DOTA. (orig.).
A tick/rickettsial survey in various parts of Switzerland revealed the presence of a new, hitherto undescribed spotted fever group rickettsia ("Swiss agent") in up to 11.7% of I. ricinus collected off vegetation. Infection in ticks was found to be generalized with rickettsiae developing intracellularly and occasionally also intranuclearly. As a result of massive growth in ovarial tissues, including the germinative cells, the rate of transovarial and filial infection was 100%. The "Swiss agent" appears to be nonpathogenic for guinea pigs, domestic rabbits, and Swiss mice, but in male meadow voles (Microtus pennsylvanicus) it produces a microscopically detectable infection in the tunica vaginalis. The rickettsia grows well in tissue culture systems including chick embryo fibroblast, Vero, and vole tissue cells, when inoculated via yolk sac into 5-day-old hens' eggs, it kills 100% of the embryos after 5 to 7 days. Antigenic relatedness of the "Swiss agent" to ...
The heavy chains of Acanthamoeba myosins, IA, IB and II, turkey gizzard myosin, and rabbit skeletal muscle myosin subfragment-1 were specifically labeled by radioactive ATP, ADP, and UTP, each of which is a substrate or product of myosin ATPase activity, when irradiated with uv light at 0"0C. With UTP, as much as 0.45 mol/mol of Acanthamoeba myosin IA heavy chain and 1 mol/mol of turkey gizzard myosin heavy chain was incorporated. Evidence that the ligands were associated with the catalytic site included the observations that reaction occurred only with nucleotides that are substrates or products of the ATPase activity; that the reaction was blocked by pyrophosphate which is an inhibitor of the ATPase activity; that ATP was bound as ADP; and that label was probably restricted to a single peptide following limited subtilisin proteolysis of labeled Acanthamoeba myosin IA heavy chain and extensive cleavage with CNBr and trypsin of labeled turkey gizzard myosin heavy ...
Treatment of cultures of 3T3-L1 cells with methylisobutyl-xanthine and dexamethasone has been shown to result in accumulation of lipid and conversion to the morphology of adipocytes in more than 90% of the cells. The status of the stimulatory (Gs), inhibitory (Gi) and Go-proteins during the course of 3T3-L1 differentiation was examined. The amount of alpha subunit of Gs (#alpha#Gs), assayed by radiolabeling in the presence of cholera toxin and ["3"2P]NAD"+, increased upon differentiation as previously described by others. The amounts of #alpha#Gi and #alpha#Go assayed by radiolabeling in the presence of pertussis toxin and ["3"2P]NAD"+ increased 3-fold upon differentiation. Immunoblots of cell membranes subjected to gel electrophoresis in sodium dodecyl sulfate were probed with two rabbit antisera raised against bovine brain #alpha#Go and with one raised against the#beta#-subunit of the bovine rod-outer-segment G-protein, referred to as transducin. The ...
In 18 piglets, weighing 10-15 kg, third-degree burns or full-thickness skin excisions of 4 X 4 cm were inflicted. The effect of five dressing materials on adhesiveness to the wounds, appearance, conformability, wound contraction, bacterial count, and morphology of the wound was studied at the end of the seventh and fourteenth days without dressing changes. In 11 piglets with a burn wound, the most adherent dressing was collagen sponge(CS), followed by polyurethane sponge (PU), pigskin xenograph (PS), and xeroform. CS more effectively debrided the wound from coagulated necrotic tissue than the other dressings. Wound contraction was maximal with CS dressing (52%), followed by PU (44%), xeroform (32%), and PS (27%). In another seven piglets with full-thickness excised wounds, a velour dressing made of polytetrafluoroethylene (PTFE) or PU adhered significantly more than CS or PS. Wound contraction was greater with CS (37%) or PTFE (35%) than with PS (23%) or PU (18%). The bacterial counts ...
Two overlapping cDNA clones encoding human DNA topoisomerase II were identified by two independent methods. In one, a human cDNA library in phage {lambda} was screened by hybridization with a mixed oligonucleotide probe encoding a stretch of seven amino acids found in yeast and Drosophila DNA topoisomerase II; in the other, a different human cDNA library in a {lambda}gt11 expression vector was screened for the expression of antigenic determinants that are recognized by rabbit antibodies specific to human DNA topoisomerase II. The entire coding sequences of the human DNA topoisomerase II gene were determined from these and several additional clones, identified through the use of the cloned human TOP2 gene sequences as probes. Hybridization between the cloned sequences and mRNA and genomic DNA indicates that the human enzyme is encoded by a single-copy gene. The location of the gene was mapped to chromosome 17q21-22 by in situ hybridization of a cloned fragment to ...
A brief description of the physical process of dose enhancement effects produced by X-ray radiation on materials is given, with emphasis on the influence on electronic devices. The damages caused by X-ray radiation dose enhancement is more serious than that of #gamma#-ray with higher energy.
Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage....Full Text Available
It is estimated that approximately a quarter of patients undergoing coronary intervention may have significant post-procedural creatinine (CK)/creatinine kinase myocardial band (CK-MB) elevations and...Full Text Available
The astonishingly efficient location and excision of damaged DNA bases by DNA repair glycosylases is an especially intriguing problem in biology. One example is the enzyme uracil DNA glycosylase (UNG),...Full Text Available
The oxidative stress theory of aging predicts that manipulations that alter oxidative stress/damage will alter aging. The gold standard for determining whether aging is altered is lifespan,...Full Text Available
Accessory cusp present on the occlusal surface may seldom pose problems. While its presence may not be a cause for alarm in most instances, it can sometimes lead to serious consequences if it is damaged....Full Text Available
Al2O3-based ceramic is one of the most widely used materials for tools employed in hardened steel turning applications due to its high hardness, wear resistance, heat resistance and chemical stability. The objective of this work is to predict the lives of Al2O3-(W, Ti)C ceramic tools in intermittent turning of hardened AISI 1045 steel by means of damage evolution model taking into account the mechanical loading and thermal effect in the cutting process. A damage evolution model analyzing the RVE with uniformly distributed interacting cracks is constructed based on micromechanics. The calculated results of the proposed damage evolution model are compared with the lives of two kinds of Al2O3-(W, Ti)C ceramic tools obtained through experiments. It is found that the proposed model can be used to predict the lives of the ceramic cutting tools in intermittent turning operation.
Thin film solar cells and solar cell testing - photovoltaic cells, radiation damage to cadmium sulfide solar cells, and airplane testing of solar cells
DNA double-strand breaks (DSBs) and other lesions occur frequently during cell growth and in meiosis. These are often repaired by homologous recombination (HR). HR may result in the formation of DNA...Full Text Available
FRAXA is one of a number of fragile sites in human chromosomes that are induced by agents like fluorodeoxyuridine (FdU) that affect intracellular thymidylate levels. FRAXA coincides with a >200...Full Text Available
Reactive oxygen species (ROS), inevitable byproducts of aerobic metabolism, are known to cause oxidative damage to cells and molecules. This, in turn, is widely accepted as a pivotal determinant of...Full Text Available
Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by α particles from radon progeny. At domestic exposure...Full Text Available
Damaging inflammation arising from autoimmune pathology and septic responses results in severe cases of disease. In both instances, anti-inflammatory compounds are used to limit the excessive...Full Text Available
Total thyroidectomy involving the adjacent structures of the trachea can cause tracheal damage such as early tracheal necrosis. The authors describe the first case of anterior tracheal necrosis following...Full Text Available
4-Hydroxynonenal (HNE), a major electrophilic product of lipid peroxidation, is regarded as both a marker of oxidative stress and a mediator of oxidative damage. At subtoxic concentrations,...Full Text Available
In order to maintain a safe operation and availability of generating facilities, qualitative and quantitative assessment of piping vibration was performed vibration sources and damages of piping support was identified on the second piping system of Wolsun...
Experiments on Xanthium leaf discs were carried out to determine whether concomitant photoreactivation could be detected and if so, to compare its effects with photoreactivation due...Full Text Available
More than 30 years ago, human beings looked back from the Moon to see the magnificent spectacle of Earth-rise. The technology that put us into space has since been used to assess the damage...Full Text Available
Acetaminophen (N-acetyl-para-aminophenol (APAP), paracetamol) is a commonly used analgesic and antipyretic agent. Although considered safe at therapeutic doses, accidental or intentional...Full Text Available
Revised neutron fluence and damage values are reported for the MOTA-2A experiment in the Fast Flux Test Facility (FFTF). This revision corrects an error with processing of the {sup 235}U(n,f) reaction. Net corrections are on the order of 5%.
Using plasma glutathione S-transferase measurements hepatocellular integrity was assessed in groups of hyperthyroid and hypothyroid patients before and after treatment. Ten of 14 hyperthyroid patients...Full Text Available
Exact anatomic knowledge about the location of the gonads and the application of corresponding measures of radiation protection are the preconditions for an efficient reduction of the danger of a possible genetic damage as a result of radiation exposition during X-ray examination of the hip joint of newborns. (VJ).
The widely accepted oxidative stress theory of aging postulates that aging results from accumulation of oxidative damage. Surprisingly, data from the longest-living rodent known, naked mole-rats [MRs;...Full Text Available
It has been sixty years since the Millers first described the covalent binding of carcinogens to tissue proteins. Protein covalent binding was gradually overshadowed by the emergence of DNA...Full Text Available
Gonadal function was studied in two groups of children previously treated for medulloblastoma with surgery followed by postoperative craniospinal irradiation. In group 1 but not in group 2, the children also received adjuvant chemotherapy for one to two years. All children in group 1 received a nitrosourea (BCNU or CCNU), plus vincristine in four and procarbazine in three patients. The nine children in group 1 showed clinical and biochemical evidence of gonadal damage with elevated serum FSH concentrations and, in the boys, small testes for their stage of pubertal development. In group 2 (n . 8), each child had completed pubertal development normally, the boys had adult sized testes and the girls regular menses. Gonadotropin values were normal in all eight children. We conclude that nitrosoureas were responsible for the gonadal damage in the children in group 1, with procarbazine also contributing to the damage in the three ...
The effect of the water-chemical regime (WCR) on damage sustained by heating surfaces of steam generators at NPP is analyzed. It is indicated that phosphate treatment with minimal excesses of phosphates in the steamgenerator water is the most optimal method of managing the WCR regime of horizontal steam generators.
Apr 25, 2010... oil per day were leaking from an oil well in the Gulf of Mexico in late April, following an explosion at an offshore drilling rig on April 20, 2010. ...
BackgroundWe have previously reported that low concentrations of cigarette smoke extract induce DNA damage without leading to apoptosis or necrosis in human bronchial epithelial...Full Text Available
BackgroundAs the resident stem cells of skeletal muscle, satellite cells are activated by extracellular cues associated with local damage. Once activated, satellite cells will re-enter...Full Text Available
BackgroundMitochondrial dysfunction, oxidative damage and the accumulation of somatic mutations in mitochondrial DNA (mtDNA) have been associated with certain neurodegenerative disorders....Full Text Available
Chemical reactions in living cells are under strict enzyme control and conform to a tightly regulated metabolic program. However, uncontrolled and potentially deleterious endogenous reactions occur,...Full Text Available
Hepatic damage occurs in males and ovariectomized (OVX), not in proestrus (PE), females following trauma-hemorrhage (T-H). The mechanism responsible for hepatoprotection remains unknown. We hypothesized...Full Text Available
In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage...Full Text Available
BackgroundChildhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the...Full Text Available
Most superconductors are quite sensitive to irradiation defects. Critical temperatures may be depressed, critical currents may be increased, by irradiation, but other behaviours may be encountered. In compounds, the sublattice in which defects are created is of significant importance. 24 refs.
Intravascular coagulation, thrombosis, and fibrin deposition often produce tissue damage in allogeneic inflammatory reactions such as allograft rejection. The mechanisms which initiate blood clotting...Full Text Available
Damage to the anterior talofibular ligament (ATFL) and cacaneofibular ligament (CFL) during ankle sprain may be linked to the development of osteoarthritis. Altered tibiotalar kinematics have...Full Text Available
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the ...
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the ...
BackgroundDNA repair is the general term for the collection of critical mechanisms which repair many forms of DNA damage such as methylation or ionizing radiation. DNA repair has...Full Text Available
A series of cyclic strain controlled tests have been carried out at 600/sup 0/C on three high temperature austenitic iron-based alloys, AISI type 316 stainless steel, Alloy 800 H and Sandvik 253 MA. The tests were carried out under constant total strain control using a constant strain rate of 0.005 s/sup -1/. By considering the changes in modulus throughout the life of each specimen it was found that damage evolution could be successfully predicted as a function of plastic strain range despite the fact that each alloy had been chosen because of a different stress response at 600/sup 0/C. Although each alloy accumulated fatigue damage in a similar manner the longer lives of Sandvik 253 MA and Alloy 800 H at a given total strain range were due to a smaller plastic strain component and a reduced stage I crack propagation rate. In the 253 MA alloy, slip was predominantly planar with some cells occasionally forming at high strain ranges. Slip was ...
Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of cellular aging. Mild stress-induced hormesis can be an effective way for reducing the accumulation of molecular...Full Text Available
BackgroundHepatitis C virus is a major cause of chronic liver diseases which can lead to permanent liver damage, hepatocellular carcinoma and death. The presently available treatment...Full Text Available
Acoustic lenses are employed in a variety of applications, from biomedical imaging and surgery to defense systems and damage detection in materials. Focused acoustic signals, for example, enable ultrasonic...Full Text Available
Silent information regulators are potent NAD+-dependent protein deacetylases, which have been shown to regulate gene silencing, muscle differentiation and DNA damage repair. Here,...Full Text Available
Plutonium possesses the most complicated phase diagram in the periodic table, driven by the complexities of overlapping 5f electron orbitals. Despite the importance of the 5f...Full Text Available
Although functional organ stem cells persist in the old, tissue damage invariably overwhelms tissue repair, ultimately causing the demise of an organism. The poor performance of stem cells in an aged...Full Text Available
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
In rats, damage to neuronal populations in some brain regions occurs in response to neonatal alcohol exposure coinciding with the period of rapid brain growth. These alcohol-induced defects...Full Text Available
A summary of research conducted during the first year is presented. The research objectives were sought by conducting two tasks: (1) investigation of probabilistic design techniques for reliability-based design of composite sandwich panels, and (2) examin...
Cracking resistance and metal damage are considered in relation to structural state for steam-pipe fittings during use. An approximate scheme is given for estimating the maximum permissible operating time in the plastic state in relation to the depth of an observed crack-type defect.
During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel ...
During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel ...
Cocaine is a worldwide used drug and its abuse is associated with physical, psychiatric and social problems. The mechanism by which cocaine causes neurological damage is very complex and involves several...Full Text Available
Stem cell therapies for neurodegenerative disorders require accurate delivery of the transplanted cells to the sites of damage. Numerous studies have established that fluid injections to the hippocampus...Full Text Available
The antitumor agent camptothecin targets DNA topoisomerase I by reversibly stabilizing a covalent enzyme-DNA intermediate. The subsequent collision of DNA replication forks with these drug-enzyme-DNA...Full Text Available
Carbon steel, copper, zinc and aluminium samples were exposed in different sizes with known ambient parameters in Gran Canaria Island and atmospheric corrosion was investigated. Weight-loss measurements used to determine corrosion damage were complemented...
The free radical theory of ageing posits that accrual of oxidative damage underlies the increased cellular, tissue and organ dysfunction and failure associated with advanced age. In support of this...Full Text Available
BackgroundNormal and pathological processes entail the production of oxidative substances that can damage biological molecules and harm physiological functions. Organisms have evolved...Full Text Available
PurposeCataract is the leading cause of blindness and is associated with oxidative damage and protein modification in the lens. In the present study, we have employed proteomic and...Full Text Available
Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks,...Full Text Available
Hundreds of thousands of people worldwide live or work in close proximity to steel mills. Integrated steel production generates chemical pollution containing compounds that can induce genetic damage...Full Text Available
Accurate calculations of atomic displacement damage in materials exposed to neutrons require detailed spectra for primary recoil nuclei. Such data are not available from direct experimental measurements. Moreover, they cannot always be computed accurately starting from evaluated nuclear data libraries such as ENDF/B-V that were developed primarily for neutron transport applications, because these libraries lack detailed energy-and-angle distributions for outgoing charged particles. Fortunately, a new generation of nuclear model codes is now available that can be used to fill in the missing spectra. One example is the preequilibrium statistical-model code GNASH. For heating and damage applications, a supplementary code called RECOIL has been developed. RECOIL uses detailed reaction data from GNASH, together with angular distributions based on Kalbach-Mann systematics to compute the energy and angle distributions of recoil nuclei. The ...
The repair process of damaged tissue involves the coordinated activities of several cell types in response to local and systemic signals. Following acute tissue injury, infiltrating inflammatory cells...Full Text Available
SummaryActivating transcription factor 2 (ATF2) is regulated by JNK/p38 in response to stress. Here, we demonstrate that the protein kinase ATM phosphorylates ATF2 on serines...Full Text Available
...visible damage. (k) Corrosion resistance. Each metal part of a...evidence of salt-spray corrosion resistance equal to or greater than...sample of test metal must show corrosion resistance equal to or better than...
A method of patterning n-type GaAs, InP, InGaAs, and InGaAsP by photoelectrochemical (PEC) etching in conjunction with a submicron focused ion beam (FIB) at low dose is described. The ion beam is used to produce damage in a desired pattern in the material. Subsequent PEC etching of the material reveals the ion induced features in relief. The procedure is highly sensitive, requiring a dose of only 5 x 10/sup 9/ ions/cm/sup 2/ for the differential etch to become apparent. The sensitivity allows rapid pattern generation in our FIB system.
We have performed molecular dynamics simulations of radiation damage in fused silica. In this study, we discuss the role of successive cascade overlap on the saturation and self-healing of oxygen vacancy defects in the amorphous fused silica network. Furthermore, we present findings on the topological changes in fused silica due to repeated energetic recoil atoms. These topological network modifications consistent with experimental Raman spectroscopic observation on neutron and ion irradiated fused silica are indicators of permanent densification that has also been observed experimentally.
In the power station West Block 2 at Voerde (Federal Republic of Germany), cracks in the final stage of the shaft were determined at the ND1 rotor of the 350 MW condensation tube was determined. A purely mechanical preparation of the crack was not possible due to the depth of the crack. A substitute rotor was not available. A repair solution was developed covering a welding of a new shaft section to the existing rotor. The authors of the contribution under consideration report on the damage, cause of the damage, repair solution and the process of repair.
The analysis for priority rankings of the recommendations to reduce the total core damage frequency (CDF) of Wolsong nuclear power plant units 2/3/4 was performed in this paper. In order to derive the recommendations, the sensitivity analysis of CDF on which major contributors effect was performed based on the accident quantification results during Level 1 probabilistic safety assessments (PSA). Priorities were ranked in the way that compares the CDF reduction rate with the efforts required to implement those recommendations using risk matrix.
Analytical models for predicting the deformation and failure of composite sandwich panels subjected to blast and projectile impact loading are presented in this paper. The analytical predictions of the transient deformations and damage initiation in the composite sandwich panels were compared with finite element solutions using ABAQUS Explicit. For the blast model, the predicted transient deformation of the sandwich panel was within 7%of FEA results, while the predicted damage initiation using Hashin's composite failure criteria was about 15%higher than FEA results in most cases. For the high velocity impact model, the predicted transient deformations were within 20%of FEA results.
The damage induced by low-temperature proton irradiation in amorphous Pd/sub 80/Si/sub 20/ prepared by ion implantation is studied via electrical resistivity measurements. Our experimental results concerning the initial damage rate and the resistivity saturation are compared to the results obtained for electron and high energy /sup 16/O irradiation of amorphous Pd/sub 80/Si/sub 20/ quenched from the melt. The resistivity curve is analyzed in terms of irradiation-induced point defects.
Life management system is based on the valid nowadays in Estonian power plants regulation documentation. The system allows to estimate stress distribution in components, find computational assessment of cumulated creep damage, determine when and where it is necessary to cut off the particular number of microsamples or take replicas. Finally, the real metal condition may be assessed on the basis of metallographic specimen research and reasonable 3-R decision - run, repair, replacement - made on further component use. (orig.) 6 refs.
Experimental results on study of helium concentration influence on degree of molybdenum radiation hardening for various method of cyclotron doping differing in degree and damage character are presented. It is established that accumulation of helium atoms in molybdenum for simultaneous formation of radiation defects caused by low energetic primary-knocked atoms leads to higher degree of hardening than for high energetic ion irradiation. It is shown that with increase of helium atom concentration the degree of radiation hardening for the same level of damage increases. 4 refs.; 3 figs. (author).
The operation of steam turbines is technically controllable. The manufacturers specify reliable operating ranges as well as demands on the implementation of steam turbines into the power plant process for the respective steam turbines. The VGB guidelines describe the generally valid procedures for the operation of steam turbines in detail. Important insights at some steam turbines are not or only insufficiently converted nevertheless. Damage and extended downtimes at revisions are the result. The author of the contribution under consideration describes some more and more occurring problems. Recommendations and suggestions are given with respect to the avoidance of such findings.
A collection of 14 papers from a June 1981 seminar assess the costs of damage caused by water pollution. The seminar focused on the economic rather than the legal standpoint by evaluating the cost of the clean-up operations themselves and other costs, such as direct or indirect economic losses, and converting into money terms the damage to the environment, the loss of recreational facilities, and biomass losses. The papers are grouped into four sections which look at the scale of risk, the clean-up costs for specific oil spills, other costs inflicted on coastal zones, and legal aspects of compensation. Separate abstracts were prepared for each of the 16 papers selected for the Energy Data Base.
ObjectivesObjectives Not AvailableDescriptionTo determine the effects of water penetration on the burst strength of filament wound composite pipes which have been damaged by impact and then subjected to long term pressurisation with sea water. ~%~ To monitor and characterise the damage and effects of sea water penetration using ultrasonic NDT. To determine the burst strength of bonded composite pipe joints with and without defects and to see whether the defects can be detected using ultrasonic NDT. [continued...
Carbon steel, copper, zinc and aluminium samples were exposed in different sizes with known ambient parameters in Gran Canaria Island and atmospheric corrosion was investigated. Weight-loss measurements used to determine corrosion damage were complemented with metallographic and XP S determination in order to characterize the structure and morphology of surface corrosion products. The ambient aggressiveness could be well evaluated from meteorological and pollution data. All atmospheric corrosion and environmental data were statistically processed for establishing general corrosion damage functions for carbon steel, copper, aluminium and zinc in terms of Gran Canaria extreme meteorological and pollution parameters. (Author)
The helicase action of the Escherichia coli UvrAB complex on a covalently closed circular DNA template was monitored using bacterial DNA topoisomerase I, which specifically removes negative supercoils. In the presence of E. coli DNA topoisomerase I and ATP, the UvrAB complex gradually introduced positive supercoils into the input relaxed plasmid DNA template. Positive supercoils were not produced when E. coli DNA topoisomerase I was replaced by eukaryotic DNA topoisomerase I or when both E. coli and eukaryotic DNA topoisomerases I were added simultaneously. These results suggest that like other DNA helix-tracking processes, the ATP-dependent action of the UvrAM complex on duplex DNA simultaneously generates both positive and negative supercoils, which are not constrained by protein binding but are torsionally strained. The supercoiling activity of UvrAB on UV-damaged DNA was also studied using UV-damaged plasmid DNA and a mutant UvrA protein ...
Austenitic 316LN alloy was ion-irradiated using the unique Triple Ion Beam Facility (TIF) at ORNL to investigate radiation damage effects relevant to spallation neutron sources. The TIF was used to simulate significant features of GeV proton irradiation effects in spallation neutron source target materials by producing displacement damage while simultaneously injecting helium and hydrogen at appropriately high gas/dpa ratios. Irradiations were carried out at 80, 200, and 350 C using 3.5 MeV Fe{sup ++}, 360 keV He{sup +}, and 180 keV H{sup +} to accumulate 50 dpa by Fe, 10,000 appm of He, and 50,000 appm of H. Irradiations were also carried out at 200 C in single and dual ion beam modes. The specific ion energies were chosen to maximize the damage and the gas accumulation at a depth of {approximately} 1 {micro}m. Variations in microstructure and hardness of irradiated specimens were studied using transmission electron ...
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 ...
In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock ...
We present a proof-of-concept analysis of the measurement of the health damage of ozone (O_3) produced from nitrogen oxides (NO_x=NO+NO_2) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NO_x emitted from individual sources can have on the downwind concentration of surface O_3, depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting O_3-related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used 'cap and trade' approach to NO_x regulation, which presumes that shifts of emission over time and space, holding the total fixed over the course of the summer O_3 season, will have minimal effect on the environmental outcome. By ...
The transmutation of minor actinides in-reactor is one solution currently being studied for the long time management of nuclear waste. In the heterogeneous concept the radionuclides are incorporating in an inert ceramic matrix. The support material must be insensitive to radiation damage. Fission product damage is the main radiation damage source during the transmutation process and therefore it is of the utmost importance to study their effects. We irradiated spinels MgAl_2O_4 (matrix of reference) and ZnAl_2O_4 by fast ions (by example: (86)Kr of approximately 400 MeV) simulating the fission products. Under these conditions, the damage is primarily due to the electronic energy losses (Se). One of the structural features of spinel AB_2O_4 is that the two cations (A(2+) and B(3+)) can exchange their site. This phenomenon is quantified by the inversion parameter. We highlight by XRD in grazing incidence ...
The epileptogenic and neurodegenerative effects of gamma-dendrotoxin, from Dendroaspis angusticeps, a specific blocker of a non-inactivating, voltage-sensitive K+ channel, were studied after focal injection into one dorsal hippocampus in rats pretreated with CGP040116, a N-methyl-D-aspartate (NMDA) receptor antagonist, and in rats bearing a monolateral surgical lesion of the Schaffer collaterals whose terminals originate from CA3 pyramids and release glutamate in the CA1 hippocampal area. Administration of 35 pmol gamma-dendrotoxin elicited in all of the treated animals (n=8) bilateral EEG discharges and damage to the hippocampal formation. Quantitation of the damage revealed significant bilateral neuronal cell loss in the CA1, CA3 and CA4 pyramidal cell layers. The lowest dose (0.35 pmol; n=4) of the toxin used did not affect EEG activity and failed to cause significant hippocampal cell loss whereas the 3.5 pmol (n=6) dose caused EEG seizures ...
A necessary condition for crevice corrosion is that a crevice former create a sufficiently tight, restricted geometry on the metal surface to support the development of critical crevice chemistry. Crevice corrosion is affected by the crevice geometry (tightness) and the properties of the crevice former. The objective of this study is to determine the effect of the crevice former material on the evolution of localized corrosion-damage. A standard crevice corrosion test method is modified by (a) the use of ceramic, metal or polymer materials as the crevice former and (b) the variation of size and shape of the crevice. This study focuses on the post initiation stage of crevice corrosion and addresses factors that may limit the initiation of localized corrosion and also slow or stop the continued propagation of corrosion. Controlled crevice corrosion tests are performed under aggressive, accelerated conditions on Ni-Cr-Mo alloy C-22 and other alloys for comparison. ...
This paper assesses the effects of including carbon dioxide capture and storage (CCS) damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate change intervention or externality internalisation), CCS technologies are likely to be deployed at least to some extent, mainly in the power generation sector, given the economic benefits of opportunities such as enhanced coal bed methane, oil and gas recovery. Under a strict climate (CO{sub 2} emissions) constraint, CCS technologies are deployed massively. With the simultaneous introduction of both CO{sub 2} and CCS taxation in the power sector, designed to internalise the external atmospheric and geological effects of CO{sub 2} emissions and storage, respectively, we ...
Geological carbon dioxide capture and storage (CCS) is currently seriously considered for addressing, in the near term, the problem of climate change. CCS technology is available today and is expected to become an increasingly affordable CO2 abatement alternative. Whereas the rapidly growing scientific literature on CCS as well as experimental and commercial practice demonstrate the technological and economic feasibility of implementing this clean fossil fuel option on a large scale, relatively little attention has been paid so far to the risks and environmental externalities of geological storage of CO2. This paper assesses the effects of including CCS damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate ...
The effect of ionizing radiation (2, 5, and 10 KGy of gamma rays) on muscle ultrastructure of grass shrimps (Penaeus monodon Fabricius) tails at ambient or frozen (-18{sup 0}C) temperature was investigated by transmission electron microscopy (TEM). No significant change was found in muscle ultrastructure of shrimp meat irradiated at doses of 2 or 5 KGy and then stored at 4{sup 0}C for 0 and 8 days. However, in shrimps which were irradiated at ambient temperature at a dose of 10 KGy, the margin of A-band of the myofibrils in longitudinal sections exhibited an irregular zig-zag pattern. In cross section some myosin filaments in the A-band regions were missing. A possible interpretation of these results would be that 10 KGy gamma irradiation dose at ambient temperature depolymerized myosin in the A-band from the tail of thick filament. Actin damage was also observed in some cross sections. Irradiation damage of sarcoplasmic membranes appeared in ...
The effect of ionizing radiation (2, 5, and 10 KGy of gamma rays) on muscle ultrastructure of grass shrimps (Penaeus monodon Fabricius) tails at ambient or frozen (-18"0C) temperature was investigated by transmission electron microscopy (TEM). No significant change was found in muscle ultrastructure of shrimp meat irradiated at doses of 2 or 5 KGy and then stored at 4"0C for 0 and 8 days. However, in shrimps which were irradiated at ambient temperature at a dose of 10 KGy, the margin of A-band of the myofibrils in longitudinal sections exhibited an irregular zig-zag pattern. In cross section some myosin filaments in the A-band regions were missing. A possible interpretation of these results would be that 10 KGy gamma irradiation dose at ambient temperature depolymerized myosin in the A-band from the tail of thick filament. Actin damage was also observed in some cross sections. Irradiation damage of sarcoplasmic membranes appeared in the ...
The paper evaluates standardization of regulations on safety of electrical equipment for underground coal mines in the USSR. Factors increasing hazards of electrical failures of equipment in underground coal mines are analyzed: reduced lighting, increased humidity and dusts, damage caused by falling rocks or damage during haulage in underground workings, installation of electrical equipment in places easily accessible to untrained personnel. Standards on safety of electrical equipment for underground coal mining valid in the USSR are reviewed: the PIRNEh regulations on production of electrical equipment for coal mines developed by the VNIIVEh Institute, and the GOST national standards. International cooperation within the COMECON on safety of mining electrical equipment (the Interelectro Committee of the COMECON) is described. Certification of electrical equipment for coal mines is discussed on the example of electrical insulation types used in ...
Steam generators (SG) are the weak link of nuclear power plants, their service life is shorter than the service life of other NPP components. This paper is dedicated to a statistical analysis of SG damages and failures. Heat exchanging tubes (HET) are the most damaged elements in SG, there are on average 286 plugged or repaired tubes in each operating SG. The usually mechanisms of tube failure are the following: denting, corrosion at tube outside, pitting, fretting, and circular crack propagation. Most of damages are located in the transition zone above a tube plate. This study shows that the factors that are involved in the SG HET fault probability are: - design features of SG and secondary equipment elements (high pressure feed heaters (HPFH), low pressure feed heater (LPFH)), - water chemistry at different points of condensate feed pipe, composition and density of deposits on HET surface, efficiency of mechanical and ...
There has been a growing interest in new laser systems for use at mid-infra-red wavelengths, driven by requirements for a number of diverse applications. Developments in mid-IR coating technology are following three major thrusts. In the first, the potential of ion-assisted process is being exploited and the technology is already becoming well established in the optical coating industry. In the second, the benefits of using gas-phase precursors are being explored, driven by the potential of avoiding the generation of second phase inclusion in the coatings with associated reduction in laser damage threshold. Research is also addressing the use of nanocomposite materials with an engineered microstructure to produce coatings with dielectric properties of choice. This paper presents a review of progress in some of these areas with special emphasis on the comparison of the properties of materials at DF laser wavelengths. Evidence is presented which suggests that laser ...
The objective of this research was to determine the extent of damage that occurs when two pipes experience an impact event due to one whipping against the other. The research was conducted through experimental and analytical approaches. The former required the development of a specialized impact machine that could accelerate a whipping pipe with sufficient energy to cause failure of a target pipe that was heated and pressurized to Pressurized Water Reactor (PWR) conditions. Damage was measured in terms of crushing, bending, and failure. The results of the tests permitted the correlation between pipes of a certain size and the damage they could cause when impacting with a certain amount of known energy. These results were used to evaluate the pipe whip criteria in the Standard Review Plan 3.6.2-4. It was established that the criteria conditions did not fully represent the results obtained experimentally. An analysis ...
Current advanced CMOS source/drain engineering involves the use of amorphizing implants with 3D geometry. Upon annealing, the induced transient enhanced diffusion (TED) can only be accurately predicted if the amorphized region is correctly modeled, as well as the formation and evolution of extended defects, particularly 3 1 1's and dislocation loops. In addition to the extended defects, already modeled in the atomistic kinetic Monte-Carlo simulator DADOS, we have developed a physically based modeling approach for the implant-induced damage build-up, amorphization and recrystallization, suitable to handle device-size process simulation. It is based on amorphous pockets (3D, irregular shape agglomerates of an arbitrary number of interstitials and vacancies, plus trapped impurities) with a size-dependent activation energy for recombination. The model is able to reproduce experimental aspects like the crystal-amorphous transition temperature and the super ...
Current advanced CMOS source/drain engineering involves the use of amorphizing implants with 3D geometry. Upon annealing, the induced transient enhanced diffusion (TED) can only be accurately predicted if the amorphized region is correctly modeled, as well as the formation and evolution of extended defects, particularly 3 1 1's and dislocation loops. In addition to the extended defects, already modeled in the atomistic kinetic Monte-Carlo simulator DADOS, we have developed a physically based modeling approach for the implant-induced damage build-up, amorphization and recrystallization, suitable to handle device-size process simulation. It is based on amorphous pockets (3D, irregular shape agglomerates of an arbitrary number of interstitials and vacancies, plus trapped impurities) with a size-dependent activation energy for recombination. The model is able to reproduce experimental aspects like the crystal-amorphous transition temperature and the super linear ...
Minority-carrier lifetime damage coefficients for 1 MeV electron, 3 MeV proton, and 6 MeV alpha particle irradiation of n-type (4.5{times}10{sup 15} and 1.3{times}10{sup 17}cm{sup {minus}3}) and p-type (2.5{times}10{sup 17}cm{sup {minus}3}) InP have been measured using time-resolved photoluminescence. These values are relatively insensitive to carrier type and show a slight increase with increasing carrier concentration. Evidence of comparable electron and hole capture lifetimes is found for the dominant recombination defect. The effect of 3 MeV proton and 6 MeV alpha particles relative to 1 MeV electrons is an increase in the lifetime damage coefficient by factors of about 10{sup 4} and 10{sup 5}, respectively. {copyright} {ital 1997 American Institute of Physics.}
Current light water reactor (LWR) steam generators have been affected by a variety of corrosion and mechanical damage degradation mechanisms. Included are wear caused by tube vibration, intergranular corrosion, pitting, and thinning or wastage of the steam generator tubing and accelerated corrosion of carbon steel supports (denting). The Electric Power Research Institute (EPRI) and the Steam Generator Owners Groups (I, II) have sponsored laboratory and field studies to provide ameliorative actions for the majority of the damage forms experienced to date. Some of the current corrosion mechanisms are aggravated or caused by unique materials choices or materials interactions. New materials have been proposed and at least partially qualified for use in replacement model steam generators, including an advanced LWR design. In so far as possible, the materials choices for the advanced LWR steam generator avoid the corrosion pitfalls seemingly inherent ...
Some of the smaller sports- und travel aircrafts are still propelled by piston engines. The first part of the article looks into some characteristic damage incidents that occur in aircraft engines. Not surprisingly, vibration fatigue failure happens most frequently. Apart from technical faults it is surprisingly lack of fuel that accounts for the high incidence of engine failure (one third). Flight turbines occasionally fail due to vibration fatigue of component parts. Added to this thermal fatigue cracks and damage due to overheating may occur in a gas turbine while the compressor parts may be affected by corrosion. (orig.) [German] Ein erheblicher Teil der kleineren Sport- und Reiseflugzeuge ist auch heute noch mit Kolbentriebwerken ausgestattet. Im ersten Teil des Aufsatzes werden daher einige charakteristische Schaeden an Flugmotoren vorgestellt. Als Versagensart dominiert erwartungsgemaess der Schwingbruch (Dauerbruch). Neben den technisch ...
Although ultrasonic testing inspection technology and tools have improved significantly, there is still a need for more reliable detection, monitoring, and accurate sizing of crack-like and planar defects, complex corrosion damage, and detection of secondary features within deformed pipe. Ultrasonic two dimensional (2D) matrix phased array technology offers some unique advantages that make the technology promising for improving detection and sizing of pipeline flaws resulting from welding or from in-service damage. Ultrasonic modeling and simulation has been conducted to evaluate the detection and sizing capabilities of 2D matrix arrays for various pipeline inspection concepts. Simulations have been performed using both flexible and rigid array probes. Inspection concepts using rigid probes were evaluated for inspections from both the outside and inside pipe surfaces, while flexible probes were evaluated primarily for inspection from the ...
Samples prepared using the focused ion beam (FIB) inevitably contain the surface damage induced by energetic Ga"+ ions. An effective method of removing the surface damage is demonstrated using a plasma cleaner, a device which is widely used to minimize the surface contamination in scanning transmission electron microscopy (STEM). Surface bombardment with low-energy Ar"+ ions was induced by biasing the sample immersed in the plasma source, so as to etch off the surface materials. The etch rates of SiO_2, measured with a bias voltage of 100-300 V, were found to vary linearly with both the time and bias and were able to be controlled from 1.4 to 9 nm/min. The removal of the Ga residue was confirmed using energy dispersive spectroscopy (EDS) after the plasma processing of the FIB-prepared sample. When the FIB-prepared sample was processed via plasma etching for 10 min with a bias of 150 V, the surface Ga damage was completely ...
Transient enhanced diffusion of phosphorus in silicon has been investigated for implants below and above the threshold for a complete amorphization. Rapid thermal processes (electron beam) and conventional furnaces have been used for the annealing. In the case of implants below amorphization, a strong enhanced diffusion, proportional to the amount of damage produced, has been observed. The extent of the phenomenon is practically independent of the damage depth position. In contrast to this, the formation of extended defects at the original amorphous-crystalline interface makes the diffusivity strongly dependent on depth in the case of post-amorphized samples. No enhanced diffusion effect is observed if the dopant is confined in the amorphous layer, while a remarkable increase in the diffusivity is detected for the dopant located in the crystalline region beyond the amorphous-crystalline interface. Damage distribution after ...
Current regulations guiding technical aspects of natural resource damage assessments combine source, exposure pathway, resource injury, and monetary damage components. In order to associate any observed injury to the uncontrolled release of chemicals (e.g. oil spills, contaminated sediments, in-place toxics, etc.), it is important to link the chemical ''release'' to the injured resource. In complex environmental settings where multiple sources of similar chemicals are combined, multicomponent chemical methods must be used to link the release to the environmental distribution of chemicals. Three examples of the utility of multicomponent organic chemical analyses linked to comprehensive and representative sampling strategies will be discussed--the Shell Martinez Refinery oil spill, the Exxon Valdez oil spill, and a contaminated sediment assessment. These NRDA-based source identifications are based on use of polycyclic aromatic hydrocarbons, ...
According to the California Earthquake Authority, only about 12% of current California residences are covered by any form of earthquake insurance, down from about 30% in 1996 following the 1994, M6.7 Northridge earthquake. Part of the reason for this decreasing rate of insurance uptake is the high deductible, either 10% or 15% of the value of the structure, and the relatively high cost of the premiums, as much as thousands of dollars per year. The earthquake insurance industry is composed of the CEA, a public-private partnership; modeling companies that produce damage and loss models similar to the FEMA HAZUS model; and financial companies such as the insurance, reinsurance, and investment banking companies in New York, London, the Cayman Islands, Zurich, Dubai, Singapore, and elsewhere. In setting earthquake insurance rates, financial companies rely on models like HAZUS, that calculate on risk and exposure. In California, the process begins with an official ...
Coal exploitation inevitably damages the natural ecological environment through large scale underground exploitation which exhausts the surrounding areas and is the cause of surface subsidence and cracks. These types of damage seriously lower the underground water table. Deterioration of the environment has certainly an impact on and limits growth of vegetation, which is a very important indicator of a healthy ecological system. Dynamically monitoring vegetation growth under coal exploitation stress by remote sensing technology provides advantages such as large scale coverage, high accuracy and abundant information. A scatter plot was built by a TM (Thematic Mapper) infrared and red bands. A detailed analysis of the distributional characteristics of vegetation pixels has been carried out. ...
This experiment is carried out in the series of the investigation on the damage mechanism of carbon steel. In this paper, the damage situation is considered by structure observations. The test were carried out in 600degC-1200degC temperature range, in blowing an argon gas. The reagents are Na{sub 2}O, Na{sub 2}O{sub 2} and NaOH. From structure observations, the holes are observed on the surface of iron-base material in some test conditions. This result is indicated that the selective reaction occurs. The selective reaction is more obvious as the time exposed to the high temperature is longer. It is considered that the selective reaction occurs after the chemical reaction between iron-base material and sodium compound. The areas, in which Mn-concentration is higher, are observed in products on the surface of specimen. (author)
The Seismic Risk Explorer, an extension for ArcGIS Desktop developed by cedim AG, is a tool for computing the seismic risk, i.e. damage on residential buildings and thereby caused monetary losses for earthquake scenarios. It is based on the research results of the CEDIM (Center for Disaster Management and Risk Reduction Technology) research center, located at the Karlsruhe Institute of Technology (KIT) and the GeoForschungsZentrum (GFZ) in Potsdam. With this software tool seismic scenarios can be simulated for a given magnitude, depths and location. The seismic intensity, the resulting mean damage ratio for residential buildings and the seismic risk, expressed as the monetary loss caused by an earthquake can be computed downscaled to communities, postcode areas or even single buildings. Interested end-users are especially insurance companies, but also public authorities which may use the tool for risk management issues.
The environmental Kuznets curve hypothesis (EKC) predicts an inverse U-shaped relationship between environmental pollution and per capita income. The literature with respect to the EKC is vast but far from conclusive. This paper adds firm size to the standard EKC reduced form regression and analyses whether firm size matters once income and composition are controlled for. Results suggest that large firm countries are initially associated with higher levels of environmental damage. However, as economies develop, large firm countries find it easier to adopt more stringent environmental legislation. Once environmental damage starts to decrease, the decrease is much larger in large firm countries.
Two cases of tetracycline ulcers of the oesophagus are reported and compared with thirteen other cases from the literature. In most cases, the patients had taken their capsules with little or no fluid just before going to bed. Some hours later they developed retrosternal pain that was intensified by swallowing. Endoscopy showed sharply demarcated greyish-white areas of mucosal damage which represented layers of stratified squamous cells, separated by oedema, and a dense neutrophilic infiltration of the lamina propria and the muscularis mucosa. Roentgenology was unsuitable to detect the lesions. They healed without complications within one to six weeks. Prolonged retention of the capsules in the oesophagus is thought to cause the mucosal damage. Patients on oral tetracycline or doxycycline treatment should therefore be instructed to take their capsules with a meal or with copious water and not just before going to bed.
Slow, unexpected displacements have been experienced in most pressurized water reactor (PWR) surge lines. Sometimes, these displacement lead to gap closure at the pipe whip restraints. These movements occur because of thermal stratification. This movement has the potential to increase stresses to valves, which may exceed the material yield stress. To understand this phenomenon, Framatome, Commissariat a l'Energie Atomique, and Electricite de France have undertaken large programs for the study of (1) thermal-hydraulic tests with a half-scale Plexiglas surge line, (2) thermal-hydraulic computations of permanent states and transients with a two-dimensional model, and (3) mechanical analysis of displacements and computation of fatigue damage due to stratification. This paper deals with the last subject. Avoiding stratification in piping by process modifications is difficult because of the high flow rate needed. Alternative solutions for coping with ...
The paper gives a detailed overview of the history of subsidence engineering in South African collieries. Surface displacements resulting from total-seam extraction are discussed, and the important role of local geology is highlighted. It is shown that the differences in subsidence behaviour between South African and European collieries can be attributed to the presence of competent strata in the overburden of South African coal seams. Criteria are given for the prediction of the most important subsidence parameters, and a new model for the simulation of surface subsidence above total-extraction panels is introduced. The final section of the paper deals with the damage to surface structures caused by total-seam extraction. A brief summary of the most important undermining experiments in South African collieries is given, and it is concluded that local experiences of damage compare with those in Europe. 32 refs., 9 figs., 3 tabs.
The integrity and safety of beam-like structures are dependent in part on their boundary conditions which can vary with time due to damage or aging. Structural health monitoring of such structures should therefore include attention to boundary conditions. Where the boundary conditions can be represented by a lumped spring then the identification of associated stiffness parameter values may be a means to quantifying the integrity of the support. This paper investigates such a method for identifying the equivalent translational and rotational stiffness of a constrained tapered beam-like structure. An analytical model of a beam of tapered width and thickness is adopted as a simplified representation of a tower-like structure. The model is used to explore in what scenarios natural frequencies and/or nodal points might be sufficiently sensitive to changes in support conditions to be measurable indicators of damage. The method is evaluated by Monte ...
The paper discusses the aspects of repair and retrofitting technique adopted for a damaged reinforced concrete beam-column joint specimen under cyclic loading. A specimen designed based on Indian Standard specifications with consideration of seismic load but without adopting ductile detailing (NonDuctile) was investigated under reverse cyclic loading. Then, the damaged nonductile specimen was repaired with epoxy mortar and grouted using low viscous polymer, and retrofitted using fiber reinforced plastic (FRP) wrapping in beam and column components and steel plate jacketing in joint region. The experimental results showed that the retrofitted specimen not only regained its original strength and stiffness but also has overcome the deficiencies of nonductile detailing. The present study shows...
The present article will review recent advances in focused ion beam (FIB) technology. With increasing demands for scale of integration, microfabrication technology is becoming more important and various new microfabrication tools and processing techniques are desired. FIB is one of the promising tools for future microfabrication technology. This provides maskless patterning capability, which is of importance for process simplification, nanofabrication and in the development of in situ vacuum processing. In situ vacuum processing systems are being developed by combining FIB and a molecular beam epitaxy system. Radiation damage may limit applications of FIB. However, it was demonstrated that low energy FIB (<1 keV) with very high brightness was reached and promising results for low damage processing have been obtained. (orig.).
Monte Carlo calculations of proton irradiation of permanent magnets for the TRADE experiment have been performed. An irradiation dose of about 4´106 Gy/yr/mA has been estimated due to beam losses in normal operating conditions. Existing experimental results indicate that this irradiation level may induce a considerable demagnetization: in fact, a dose of 6´107 Gy induces a remanence loss of 0.3 % on samples of Sm2Co17 magnets, which are the most resistant type. More detailed calculations with the final design of the magnets and of the beam line are suggested, to determine if the irradiation levels allowed a reliable operation of the permanent magnets for the entire duration of the TRADE experiment. Damage and gas production rates have also been calculated; the values obtained are very low, thus confirming that the demagnetization process is in great part reversible.
The fully depleted pn-junction charge coupled device (pn-CCD) has been developed as a detector for X-ray imaging and high-resolution spectroscopy for the X-ray satellite missions XMM and ABRIXAS. If the detector is exposed to a particle radiation environment, the energy resolution is degraded due to charge transfer losses and a dark current increase. In a first experiment, prototype devices were irradiated with 10 MeV protons. After completion of the detector development, the proton irradiation was repeated for a quantitative study of the radiation damage, relevant for the satellite missions. The irradiation test was extended by a 5.5 MeV {alpha}-particle and a 6 keV X-ray exposure of the pn-CCD, including the CAMEX preamplifier chip.
Staircase current-voltage (I-V) characteristics, observed at 77 K in narrow 2DEG channels irradiated by a single line scan of a focused ion beam (FIB), is reported in detail. These staircases are interpreted as evidence of single electron tunneling through a naturally occurring specific Coulomb island in the random potential fluctuations created by FIB damage. Clear comparison is made between the I-V's taken from wide channels and those from narrow channels. Based on orthodox calculations of the I-V characteristics, it is shown that highly asymmetric tunnel junctions are needed to explain our data. This is consistent with the random nature of the potential landscape in the FIB damaged region. (author).
Accessible summary - -Children with a Nonverbal Learning Disability (NLD) resulting from shunted hydrocephalus and spina bifida face many difficulties not experienced by those with a language learning disability. - -As they grow older and more autonomy is expected, friendships became harder to sustain and daily life can be full of fear if the nonverbal learning disability is not identified and managed. - -This paper explains the theorised cause of nonverbal learning disability - damage to right hemisphere white matter or myelin. - -Damage is believed to cause problems with planning, organisation, time management, problem-solving, decision-making and friendships, and the mismatch with articulate speech and a good vocabulary causes a functional profile that is difficult for educationists or ...
AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ``parting`` region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ``parting`` region of the welds. (orig.).
AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ''parting'' region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ''parting'' region of the welds. (orig.).
The Moessbauer emission spectrum of "2"4"1Am metal was investigated for influences of radiation self damage. Samples were kept continuously for 230 h at 4.2 K and spectra were taken each 10 to 20 h. No change in f-factor was observed, while the linewidth increased monotonically and reached saturation after approximately 180 h. The original width could be reproduced by a brief warming to room temperature. The increase in width reflects the change in quadrupole interaction due to the creation of lattice defects. The constancy of the f-factor indicates that the basic crystalline structure is retained.
Polycrystalline specimens of spinel (MgAl_2O_4) and alumina (Al_2O_3) were irradiated at room temperature and 650deg C with either dual- or triple-ion beams in order to investigate the effects of simultaneous displacement damage and helium implantation on cavity formation. The cavities in alumina were aligned along the direction of the c-axis, with diameters ranging from < 2 to 10 nm. The cavities in spinel were preferentially associated with dislocation loops and were of similar size as the cavities in alumina. Catastrophic amounts of cavitation were observed at the grain boundaries in spinel when the displacement damage level exceeded a critical value (#approx =# 20 dpa) in the presence of a fusion-relevant (#approx =# 60 appm/dpa) helium environment. (orig.).
A model is presented which describes the formation of surface damage ``gouging`` on the rails that guide rocket sleds. An unbalanced sled can randomly cause a very shallow-angle, oblique impact between the sled shoe and the rail. This damage phenomenon has also been observed in high-velocity guns where the projectile is analogous to the moving sled shoe and the gun barrel is analogous to the stationary rail. At sufficiently high velocity, the oblique impact will produce a thin hot layer of soft material on the contact surfaces. Under the action of a normal moving load, the soft layer lends itself to an anti-symmetric deformation and the formation of a ``hump`` in front of the moving load. A gouge is formed when this hump is overrun by the sled shoe. The phenomenon is simulated numerically using the CTH strong shock physics code, and the results are in good agreement with experimental observation.
A crack fault is one of the damage modes most frequently occurring in gears. Identifying different crack levels, especially for early cracks is a challenge in gear fault diagnosis. This paper aims to propose a method to classify the different levels of gear cracks automatically and reliably. In this method, feature parameters in time domain, specially designed for gear damage detection and in frequency domain are extracted to characterize the gear conditions. A two-stage feature selection and weighting technique (TFSWT) via Euclidean distance evaluation technique (EDET) is presented and adopted to select sensitive features and remove fault-unrelated features. A weighted K nearest neighbor (WKNN) classification algorithm is utilized to identify the gear crack levels. The gear crack experime...
Pattern formation on GaAs by Ga"+ focused-ion-beam (FIB) irradiation and subsequent Cl_2 gas etching was carried out. A higher etch rate at the FIB-irradiated area compared with that not irradiated under Cl_2 gas allows pattern construction without a mask process. The degree of residual crystal damage was evaluated using photoluminescence (PL) intensity measurements. The PL intensity in the etched region was one order of magnitude stronger than that of FIB sputtering, and was several times stronger than that of Ga"+ FIB-assisted Cl_2 etching. Etch depths of the order of 100 nm, which is five times deeper than that obtained by FIB sputtering, were efficiently performed using moderate Ga"+-ion doses.
Pattern formation on GaAs by Ga{sup +} focused-ion-beam (FIB) irradiation and subsequent Cl{sub 2} gas etching was carried out. A higher etch rate at the FIB-irradiated area compared with that not irradiated under Cl{sub 2} gas allows pattern construction without a mask process. The degree of residual crystal damage was evaluated using photoluminescence (PL) intensity measurements. The PL intensity in the etched region was one order of magnitude stronger than that of FIB sputtering, and was several times stronger than that of Ga{sup +} FIB-assisted Cl{sub 2} etching. Etch depths of the order of 100 nm, which is five times deeper than that obtained by FIB sputtering, were efficiently performed using moderate Ga{sup +}-ion doses.
Introduction: The orofacial clefts include 30 variant according to Tessier classification: the number 30 contain mandibular arc damage isolated or associated with damage of surrounding soft tissue. Case report: Our patient was a newborn with median mandibular cleft associated with ankyloglossia, bifid tongue and a top cervical fistula. We have not found polymalformative syndrome. The early surgical management included one time and after-effect were simple within 11months. Discussion: We point up difficulties for antenatal diagnosis and controversy about appropriate time for management of bone defect. The last physiopathologic hypotheses were explicated.
The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminum matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of embryo-damage induced nucleation by fracture of brittle particles ...
The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 {mu}m minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga{sup +} focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated.
A review of the deep-level defects observed in both electron- and proton-irradiated GaAs solar cells is presented. Studies of the effects of periodic and continuous thermal annealing on the radiation-induced electron and hole traps and the recombination parameters in GaAs solar cells were made for a wide range of electron and proton energies, fluence, annealing temperature and annealing time. A refined model for numerical simulations of the displacement damage was developed for computing the defect density and the cell parameters in the electron- and proton-irradiated GaAs solar cells. Excellent agreement was obtained between the calculated values and the experimental data for the proton-irradiated GaAs solar cells. (orig.).
On Oct. 24, 2005, Hurricane Wilma, a category 5 storm, made landfall at Cape Romano, Florida. Three days later, the Center for Robot-Assisted Search and Rescue at the University of South Florida deployed an iSENYS helicopter and a prototype unmanned water surface vehicle, AEOS-1, to survey damage in parts of Marco Island, 14 km from landfall. The effort was the first known use of unmanned sea surface vehicles (USVs) for emergency response and established their suitability for the recovery phase of disaster management by detecting damage to seawalls and piers, locating submerged debris (moorings and handrails), and determining safe lanes for sea navigation. It provides a preliminary domain theory of postdisaster port and littoral inspection with unmanned vehicles for use by the human-robot ...
The SCDAP computer code, which is being developed under the sponsorship of the United States Nuclear Regulatory Commission, models the progression of light water reactor core damage including core heatup, core disruption and debris formation, debris heatup, and debris melting. SCDAP is being used to help identify and understand the phenomena that control core behavior during a severe accident, to help quantify uncertainties in risk assessment analysis, and to support planning and interpretation of severe fuel damage experiments and data. Comparisons between SCDAP calculations and the experimental data showed good agreement. Calculated and measured bundle temperatures for SFD-ST were within 200 K for the entire bundle and within 20 K for maximum cladding temperatures. For ESSI-2, calculated and measured maximum cladding temperatures were within 50 K, and the extensive liquefaction and relocation that was calculated was in agreement with ...
The possible long term effects of chronic radiation exposure have been studied. Rats were given tritiated drinking water (3#mu#Ci/ml) before pregnancy, during pregnancy and threafter, continuously through 5 generations. The brains were studied at 30 and 120 days postnatally. Significant decreases in weight, DNA and protein contents of specific parts of the brain were found, the most pronounced decreases being in the diencephalon. The decreases in protein content were more pronounced than the decreases in DNA content; the decreases were also more pronounced at 30 days than at 120 days, and more pronounced in the fifth generation than in previous generations. An attempt was made to explain these complex phenomena on the basis of known periods of proliferation of various brain cells, damage to mothers themselves in each generation, and damage and repair of nucleic acids caused by radioactivity.
Anti-reflective coatings made with Teflon AF2400 had the highest damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, maintained the bulk optical properties of a high transmittance from 200 nm to 1600 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.
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.
The performance of advanced ceramics under cavitation loading in distilled water was studied by using a laboratory test with vibration-induced cavitation following the pattern of the ASTM standard G32-92. The hardened and tempered martensitic steel 100Cr6 was used as a reference. The aim was to identify mechanisms and the effects of important microstructural parameters on damage of polished Al{sub 2}O{sub 3}, Al{sub 2}O{sub 3}-ZrO{sub 2}, ZrO{sub 2} and SiC ceramics. Results showed that surface damage of brittle ceramics was mainly dominated by intergranular fracture, followed by detachment of single grains or fragments of them. Both incubation time and erosion rate were affected by the amount of initial surface cavities, grain sizes and secondary phases at grain boundaries. (orig.)
Circadian rhythms affect several processes in the body physiology. This commentary revisits the topic of `metabolic basis of diseases' with a view to shed light on how cellular energy requirements feed-forward to a sequential signaling of hormonal response, blood glucose metabolism, antioxidant activities, and pathophysiology. Attempt is made to explain how diseases that may not appear to be closely related, such as bone metabolism and vasculopathy, have an increase in oxidative damage as a common underlying biochemistry. Importantly, this article identifies oxidative damage as an outcome of sleep disturbance and hypothesize that sleep complaint is not merely one of many resulting symptoms of PTSD, but a core feature that arise from trauma and gives rise to the stress biochemistry, which i...
Thermoluminescence (TL) properties of sphene and epidote are of interest in studies related to their radiation damage. Natural and artificially induced TL of these minerals has, therefore, been investigated. Both minerals exhibit complex glow curves with several overlapping peaks. The Tsub(m) -Tsub(STOP) thermal cleaning procedure has revealed three peaks in the ..gamma.. ray induced glow curve of each mineral. That these peaks obey second order kinetics was indicated by the continuously slanting structure of the Tsub(m)-Tsub(STOP) curve. The TL parameters E and s have been calculated using (i) the initial rise method, and (ii) the glow-peak shape method. In general, the values of E calculated by the first method are found to be higher than those from the second. The TL curve-fitting method is also applied in order to calculate these parameters and to serve as a cross-check on the results.
North American design codes are now committed to the development of load and resistance factor design (LRFD) for reinforced soil structures including internal stability limit states. Reliability-based analysis is required to carry out these calibrations. A framework for LRFD calibration has been proposed by the writers that requires bias statistics for load and resistance terms for each limit state function. In this paper the formulation of the limit state for reinforcement tensile rupture is developed and the component strength-reduction bias statistics identified. The paper describes how to compute bias statistics from project-specific installation damage trials for use in reliability-based design for the reinforcement rupture limit state or using data from multiple sources for LRFD cali...
This paper provides a physically-based engineering model to estimate radiation hardening of 9%Cr-steels under both displacement damage (dpa) and helium. The model is essentially based on the dispersed barrier hardening theory and the dynamic re-solution of helium under displacement cascades but incorporating a number of assumptions and simplifications [Trinkaus, J. Nucl. Mater. 318 (2003) 234-340]. As a result, the kinetics of the damage accumulation kept fixed, its amplitude is fitted on one experimental condition. The model was rationalized on an experimental database that mainly consists of 9%Cr-steels irradiated in the range of 50-600degreeC up to 50dpa and with a He-content up to 5000appm. The test temperature effect is taken into account through a normalization procedure based on the...
Identifying gear damage categories, especially for early faults and combined faults, is a challenging task in gear fault diagnosis. This paper proposes a new multidimensional hybrid intelligent diagnosis method to identify different categories and levels of gear damage automatically. In this method, Hilbert transform, wavelet packet transform (WPT) and empirical mode decomposition (EMD) are performed on gear vibration signals to extract additional fault characteristic information. Then, multidimensional feature sets including time-domain, frequency-domain and time-frequency-domain features are generated to reveal gear health conditions. Multiple classifiers based on several classification algorithms and input features are combined with genetic algorithm (GA). Because of the use of multidim...
A {lambda}gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. ...
A #lambda#gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate 22 monoclonal antibodies (mAbs) and a mouse polyclonal antiserum specific for the E. histolytica portion of the fusion protein. ...
A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation studies of this gas. The effect of 4-hour exposure to ozone (O/sub 3/) at concentrations of 0.0, 0.2, 0.5, 1.0, and 2.0 ppm was determined in rabbits, guinea pigs, rats, hamsters and mice. Lavage fluid protein (LFP) accumulation 18 hr after exposure was used as the indicator of O/sub 3/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 ug/ml) when a volume of saline which approximated the total lung capacity was used for lavage of the collapsed lungs. Exponential dose-response curves were seen in all species except guinea pigs, which showed significant increases in LFP at low O/sub 3/ concentrations (0.2 ppm) and a leveling off of response at the higher O/sub 3/ levels. Other species usually showed significant elevations in LFP ...
The authors have localized and characterized 2-125I-iodomelatonin binding sites in the chicken brain using in vitro quantitative autoradiography. Binding sites were widely distributed throughout the chicken brain, predominantly in regions associated with the visual system. The specific binding of 2-125I-iodomelatonin to discrete chicken brain areas was found to be saturable, reversible, and of high affinity. The specific binding of 2-125I-iodomelatonin (75 pm) was quantitated for 40 identifiable brain regions. Eight brain regions were chosen for binding characterization and pharmacological analysis: optic tectum, Edinger-Westphal nucleus, oculomotor nucleus, nucleus rotundus, ventral supraoptic decussation, ventrolateral geniculate nucleus, neostriatum, and ectostriatum. These regions showed no rostral-caudal gradient in 2-125I-iodomelatonin specific binding, and saturation analysis revealed a single class of high-affinity sites with KD values in the range of 33-48 pM and receptor site ...
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 ...
Rabbit antisera raised to human and chicken MHC molecules were used to immunoprecipitate cross-reactive molecules from biosynthetically and cell surface-labeled spleen and/or blood cells of representative vertebrate species. Five major points emerged: 1) There were many nonspecific cross-reactions using these techniques, so various criteria were developed to distinguish these from true MHC-like molecules. 2) Only very small subpopulations of immunogen-specific antibodies cross-reacted with MHC-like molecules in other nonmammalian species. These subpopulations were different for each species and even within a species, sometimes being so limited as to behave like alloantisera. This led to a very scattered pattern of true cross-reactions that sometimes failed to reflect the properties of the bulk antibody population. 3) Antisera containing antibodies to class II beta- and class I alpha-chains cross-reacted better and more widely than those to B-G, class II alpha and, ...
We present a femtosecond Laser Two-Photon Polymerization (LTPP) system of large scale three-dimensional structuring for applications in tissue engineering. The direct laser writing system enables fabrication of artificial polymeric scaffolds over a large area (up to cm in lateral size) with sub-micrometer resolution which could find practical applications in biomedicine and surgery. Yb:KGW femtosecond laser oscillator (Pharos, Light Conversion. Co. Ltd.) is used as an irradiation source (75 fs, 515 nm (frequency doubled), 80 MHz). The sample is mounted on wide range linear motor driven stages having 10 nm sample positioning resolution (XY--ALS130-100, Z--ALS130-50, Aerotech, Inc.). These stages guarantee an overall travelling range of 100 mm into X and Y directions and 50 mm in Z direction and support the linear scanning speed up to 300 mm/s. By moving the sample three-dimensionally the position of laser focus in the photopolymer is changed and one is able to write complex 3D ...
The purpose was to develop a simplified and reliable method of separating free from antibody-bound ligand using a precipitating antibody linked to a cellulose derivative. Dose-response curves and control sera were set up in parallel for various pituitary and placental polypeptides, steroid hormones, insulin, glucagon, triiodothyronine, thyroxine, angiotensin I, calcitonin, gastrin, cyclic AMP, and digoxin. After first-antibody reactions had reached equilibrium, free and bound ligand were separated using a double-antibody solid-phase system in parallel with conventional methods, including dextran-coated charcoal, double-antibody precipitation, single-antibody solid phase, organic solvents, salt precipitation, and anion-exchange resins. The effect of variations in temperature, incubation time, protein content, pH, and amount of separating material added were studied. The results showed that separation was complete within 1 hr for small ligand molecules and within 2 hr for larger ones. ...
The purpose was to develop a simplified and reliable method of separating free from antibody-bound ligand using a precipitating antibody linked to a cellulose derivative. Dose-response curves and control sera were set up in parallel for various pituitary and placental polypeptides, steroid hormones, insulin, glucagon, triiodothyronine, thyroxine, angiotensin I, calcitonin, gastrin, cyclic AMP, and digoxin. After first-antibody reactions had reached equilibrium, free and bound ligand were separated using a double-antibody solid-phase system in parallel with conventional methods, including dextran-coated charcoal, double-antibody precipitation, single-antibody solid phase, organic solvents, salt precipitation, and anion-exchange resins. The effect of variations in temperature, incubation time, protein content, pH, and amount of separating material added were studied. The results showed that separation was complete within 1 hr for small ligand molecules and within 2 hr for larger ones. ...
Duchenne and Becker muscular dystrophies are caused by defects of dystrophin, which forms a part of the membrane cytoskeleton of specialized cells such as muscle. It has been previously shown that the dystrophin-associated protein A1 (59-kDa DAP) is actually a heterogeneous group of phosphorylated proteins consisting of an acidic ({alpha}-A1) and a distinct basic ({beta}-A1) component. Partial peptide sequence of the A1 complex purified from rabbit muscle permitted the design of oligonucleotide probes that were used to isolate a cDNA for one human isoform of A1. This cDNA encodes a basic A1 isoform that is distinct from the recently described syntrophins in Torpedo and mouse and is expressed in many tissues with at least five distinct mRNA species of 5.9, 4.8, 4.3, 3.1, and 1.5 kb. A comparison of the human cDNA sequence with the GenBank expressed sequence tag (EST) data base has identified a relative from human skeletal muscle, EST25263, which is probably a human ...
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with [{sup 99m}Tc(pap){sub 3}]{sup +} showing elevated levels in ...
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with ["9"9"mTc(pap)_3]"+ showing elevated levels in the kidneys ...
Intact rat fat cell exposed to 12.5 ..mu..M (..gamma..-32P)ATP incorporate label into specific proteins within minutes. By solubilizing the reaction mixture with SDS which bypasses the subcellular fractionation steps, the labeled proteins can be identified in autoradiographs of SDS-PAGE gels. The most prominently labeled protein has an M/sub r/ of 42,000. Localization of this component to the cell surface can be made on the basis of inhibition of phosphorylation by addition of a protein derived from the rat brain with protein kinase inhibitory property, susceptibility of the phosphorylated protein to the tryptic digestion, inhibition of phosphorylation of this protein after brief exposure to melittin. To rule out the possibility that the cell surface protein might be a mitochondrial contaminant from broken cells, /sup 32/Pi-labeled and (..gamma..-/sup 32/P)ATP-labeled cells were chromatographed on a rabbit anti-pyruvate dehydrogenase antibody-Sepharose 4B column. A ...
Glycosaminoglycans (GAG) are believed to be important in the pathogenesis of atherosclerosis. We have previously demonstrated that areas of injured aorta that have been re-endothelialized accumulate increased amounts of lipid and GAG when compared to areas remaining de-endothelialized. We have now examined the net incorporation of labeled precursors into the individual GAG present in both re-endothelialized and de-endothelialized areas of rabbit aorta. Aortic tissue was examined at 2-3 and 10-14 weeks after a denuding injury by incubating tissue minces with (/sup 3/H)glucosamine and sodium (/sup 35/S)sulfate for 24 hr. Following incubation, the aortic GAG were isolated and assayed for uronic acid concentration and radioactivity. Results indicate that the total GAG concentration was significantly greater in the re-endothelialized as compared to de-endothelialized areas. The concentration in uninjured aorta was 9.01. The difference between the injured tissues was ...
The spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) has two major functions: interacting with the receptor to mediate virus entry and inducing protective immunity. Coincidently, the receptor-binding domain (RBD, residues 318-510) of SAR-CoV S protein is a major antigenic site to induce neutralizing antibodies. Here, we used RBD-Fc, a fusion protein containing the RBD and human IgG1 Fc, as a model in the studies and found that a single amino acid substitution in the RBD (R441A) could abolish the immunogenicity of RBD to induce neutralizing antibodies in immunized mice and rabbits. With a panel of anti-RBD mAbs as probes, we observed that R441A substitution was able to disrupt the majority of neutralizing epitopes in the RBD, suggesting that this residue is critical for the antigenic structure responsible for inducing protective immune responses. We also demonstrated that the RBD-Fc bearing R441A mutation could not bind to soluble and ...
Environmental monitoring has been conducted at the U.S. Department of Energy`s (DOE`s) Hanford Site in southeastern Washington State since 1945. Fish and wildlife have been monitored since 1945, however, a major emphasis on mammals did not occur until the 1970s. This report focuses on the 10-year period from 1983 through 1992. The objectives of this report are to evaluate {sup 90}Sr and {sup 137}Cs concentrations in Site wildlife populations and, when possible, evaluate trends in concentrations over this period of time. No distinct trends in radionuclide concentrations were apparent in most species sampled. Many measurements were at or below the analytical limit of detection. This evaluation found that concentrations of {sup 90}Sr in rabbit and deer bone were elevated in animals collected from areas adjacent to industrialized areas. Similarly, radionuclide concentrations in duck muscle from waterfowl collected at B Pond were elevated with {sup 137}Cs when compared ...
Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This leads to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate "1"6"6Ho-Hydroxyapatite ("1"6"6 Ho-HA) as potential radiopharmaceutical for the symptomatic treatment of chronic and acute arthritis. Materials and Methods: Holmiun-166 was produced by irradiation of Ho_2O_3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthesized. Its labelling and quality controls follows the internationally accepted procedures. An antigen's arthritis was induced to eight New Zealand rabbits with the "1"6"6 Ho-HA radiochemical being administered thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon ...
When the vehicle-treated, sham-operated mice underwent heat stress, the fraction survival and core temperature at +4 h of body heating were found to be 5 of 15 and 34.4°C ± 0.3°C,...Full Text Available
Superconducting thin film particle detectors can be very attractive due to the low sensitivity to radiation damage. We describe the fabrication procedure and the characterization of Nb/Al bilayers as particle detectors. First steady and dynamical results are reported from tests of 5 MeV alpha-particle detection.
In combined cycle turbine power stations, soft material compensators are used which, if the full pressure fails, also withstand a small external pressure. Innovative forms of construction which guarantee useful life, are presented in relation to the design. Damaging effects, which limit the life of these special soft material compensators, are discussed. (orig.)
In order to prevent corrosion failures of machines and structures, it is desirable to know in advance when the corrosion damage will take place, and appropriate measures are needed to mitigate the damage. The corrosion predictions are needed both at development as well as operational stage of machines and structures. There are several forms of corrosion process through which varying degrees of damage can occur. Under certain conditions these corrosion processes at alone and in other set of conditions, several of these processes may occur simultaneously. For a certain type of machine elements and structures, such as gears, bearing, tubes, pipelines, containers, storage tanks etc., are particularly prone to pitting corrosion which is an insidious form of corrosion. The corrosion predictions are usually based on experimental results obtained from test coupons and/or field experiences of similar machines or parts of a ...
It is reported on examination-technical possibilities with craniocerebral Computer Tomography in the peri- and postnatal period. Some typical tomographic images from a 17 1/2 months period in our own patient material of 327 children are demonstrated. The special advantages of this new technical-extensive method are: exact diagnoses, observation possibility of the longitudinal section, and the absolute harmlessness to the child.
The study required by the West German Ministry of Research and Technology (RS 605) for the Committee on 'Future Nuclear Energy Policy' of the 9th German Parliament is concerned with the following main points: 1) Assessment of technical risks from the social aspect; 2) Discussion of terms and quantification of risks; 3) 'Engineering judgment' and 'questionable' methods in the Fast Breeder analysis of the Society for Reactor Safety (GRS); 4) Assessment criteria of potential damage. (HP).
To make a quantitative comparison of risks between the SNR 300 and a modern PWR (Biblis B), the consequences of an accident or the extent of damage of a release of radionuclides to the environment due to an accident are estimated by computer programs for accident consequence models. The accident analysis includes an analysis of events for Bethe-Tait accidents with failure of the outer containment. The FGSB release rates are compared with those of the Society for Reactor Safety (GRS). (HP).
The volume contains reports on plant technology, on systems organisation with the aim to minimize the risk (human error), on the problem of seismic risk, on core-disruptive accidents and on accident consequence models with different release categories and a comparison of the potential damage incurred. Mr. Webb; one of the authors, attempts to disprove the objections to his two earliest SNR statements by experts of Karlsruhe Nuclear Research Centre.
The volume contains reports on plant technology, on systems organisation with the aim to minimize the risk (human error), on the problem of seismic risk, on core-disruptive accidents and on accident consequence models with different release categories and a comparison of the potential damage incurred. Mr. Webb; one of the authors, attempts to disprove the objections to his two earliest SNR statements by experts of Karlsruhe Nuclear Research Centre. (AK).
Amidst the explosion of greenfield natural gas-fired combined-cycle plant development, opportunities still exist for valuable plant repowering and retrofits by taking advantages of unique technical and market conditions. One of the projects discussed is the rebuilding of the coal-fired Hawthorne unit 5 damaged by a boiler explosion. 3 tabs., 5 photos.
Some aspects of molecular mechanisms common to radiation and chemical carcinogenesis are discussed, particularly the DNA damage done by these agents. Emphasis is placed on epidemiological considerations and on dose-response models used in risk assessment to extrapolate from experimental data obtained at high doses to the effects from long-term, low-level exposures. 3 references, 6 figures. (ACR)
The structural variations of amorphous metals, such as Pd/sub 80/Si/sub 20/, with irradiation of helium ion, neutron, and gamma ray have been mainly pursued by the method of X-ray diffraction and thermal analysis. It should be noticed that the amorphous metals show a radiation resistance, that is, no remarkable structural changes under helium ion, neutron, and gamma ray irradiation.
Substances which exercise a pulmonary toxic action will first of all produce alveolar and perivascular oedemas followed by fibrosis. Differential diagnosis is explained on the basis of two cases of a fatal mitomycin fibrosis of the lung, as well as the observation of fibrous changes following the administration of Bleomycin and Metothrexat. The course of pulmonary fibroses caused by paraquat is described for two cases of fatal paraquat intoxications. (orig.).
Radiation therapy has shown definite technical improvement due to application of proton beam irradiation. Clinical results of proton beam therapy also suggested enlargement of indication ranges in radial treatment and decrease of post radiation damages of the treatment of cancers in deep-seated organs. Inprovement of result in cancer therapy could be expected by this treatment technique in the future.
The seawater in the intake structure flows into the large pump to with draw excess heat from the turbine steam condenser. In the intake structure of a nuclear power plant, undesirable pump operating characteristics such as vortices, impeller damages and non-uniform pump-approach flow around the pump bells take place frequently due to poorly-arranged intake geometry. In this study, physical modeling test was performed to predict the hydraulic phenomenon, and proposed flow control devices.
The initiation and progression of several forms of retinal degenerations involve excessive, repetitive, and/or sustained oxidative stress that, in turn, mediate photoreceptor cell damage and...Full Text Available
The productivity characteristics of perforated gas well are investigated for the first time under real conditions considering drilling damage, perforation compacted zone and anisotropy in this paper. A non-linear finite element model for non-Darcy flow in perforated gas reservoir is built to consider the effects of twelve factors on productivity ratio (PR) of perforated gas well. The nomographs for two cases are presented in this paper. Compared with previous works, the following results are found: (1) the effects of drilling damage and perforation diameter on PR of gas well are more remarkable than that in oil well; (2) any perforation phase may be the best or the worst as to perforating gas well, which depends on anisotropy, drawdown and that whether or not perforations are beyond drilling damage zone; (3) the increase in perforation length hardly improve PR of gas well when perforations have been beyond drilling ...
It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.
In this paper we propose a method for construction of feed-forward neural classifiers based on regularization and adaptive architectures. Using a penalized maximum likelihood scheme, we derive a modified form of the entropic error measure and an algebraic estimate of the test error. In conjunction with optimal brain damage pruning, a test error estimate is used to select the network architecture. The scheme is evaluated on four classification problems. PMID:12662736
The paper discusses the role of the Life Management Programme in ensuring a safe operation of the Dukovany nuclear power plant. The Programme involves the following major items: (i) primary circuit materials degradation assessment, (ii) pipeline damage control by the Flow Assisted Corrosion Monitoring and Prediction Programme, and (iii) the DIALIFE diagnostic system. (author)
A brief tutorial on the health effects of ionising radiation is presented. The distinction between somatic and genetic health effects is explained. The two types of somatic health effects, i.e., acute and chronic effects, are discussed, as well as the concepts of ''deterministic'' and ''stochastic'' (also called ''probabilistic'') health effects. The possibility of cancer caused by DNA damage is discussed. The document ends with the definition of some key radiation terms.
A thesis is presented on improving the understanding of the fatigue properties of wood and fatigue failure mechanisms in the design of wind turbine blades. Three main areas were researched: the effect of R ratio on fatigue life, the effect of moisture on fatigue life and the development of cumulative damage laws. Tests were carried out on mainly four-ply laminates. Recommendations to future work are outlined. (U.K.).
Polycrystalline Al2O3, magnesium aluminate spinel (MgAl2O4), MgO, Si3N4, and SiC were irradiated with various ions at 200-450 K, and microstructures were examined following irradiation using cross-section TEM. Amorphization was not observed in any of the irradiated oxide ceramics, despsite damage energy densities up to {similar_to}7 keV/atom (70 displacements per atom). On the other hand, SiC readily amorphized after damage levels of {similar_to}0.4 dpa at room temperature (RT). Si3N4 exhibited intermediate behavior; irradiation with Fe{sup 2+} ions at RT produced amorphization in the implanted ion region after damage levels of {similar_to}1 dpa. However, irradiated regions outside the implanted ion region did not amorphize even after damage levels > 5 dpa. The amorphous layer in the Fe-implanted region of Si3N4 did not appear if the specimen was simultaneoulsy irradiated with 1-MeV He{sup +} ions at ...
A detailed investigation of the damage formation and evolution in ion-implanted crystalline Si is presented. Deep-level transient spectroscopy has been used to monitor room temperature migration of point defect complexes and evolution from simple point-like defect complexes to defect clusters and even extended defects. Si samples were implanted with Si or He ions with energies of 145 keV-3MeV, to fluences in the range 5x10[sup 8]-5x10[sup 13]cm[sup -2]. The effects of thermal annealing, in the range 100-680 C and 10 min-15h, were also explored. A systematic comparison of defect complexes formation and evolution in ion-implanted or electron-irradiated Si samples with a different impurity content were used to assess the role of impurities (C and O), extra implanted ion and defect clustering on the nature and thermal stability of residual damage. In particular, an interstitial excess directly resulting from the extra implanted ion is shown to ...
With reference to three hypotheses on the causes of forest decline, the manifold uses of forest decline surveys are demonstrated. Hypothesis no. 1: Forest disease from high-voltage transmission lines; hypothesis no. 2: Forest disease as the consequence of damage from micorrhizas; hypothesis no. 3: Radioactivity as the cause of the increased incidence of forest disease. (orig./MG)
Exposures from most natural and artificial sources, with the exception of those from medical radiology, are received at average dose rates of only a few microsieverts a day. Such risks as may be caused by these exposures are most unlikely to be determined with precision directly by epidemiological studies of populations exposed at these low rates. They may, however, be reliably inferred from the observed risks of exposure to rather larger doses delivered at higher dose rates in the light of the increasing knowledge of the phenomena involved in the initial cellular damage, the extent to which such damage is incorrectly repaired, and the processes which intervene between the genetic or other harm to cells and the likelihood of its final expression in inherited abnormality, in cancer development, or in defective foetal or embryonic growth. Current studies are of great importance, therefore, in examining the circumstances in which coding sections ...
Oxidized DNA bases, particularly 7,8-dihydro-8-oxoguanine (8-oxoG), are endogenously generated in cells, being a cause of carcinogenic mutations and possibly interfering with gene expression. We found...Full Text Available
The results of Sandia National Laboratories' participation in the NASA Planetary Definition and Design Program are summarized. Areas reported include the characterization of large area cadmium zinc telluride spectrometers and the application of simulation techniques to the prediction of device performance. Also investigated was the response of mercuric iodide devices in the region from 1 to 100 KeV. A literature study to determine the status or radiation damage measurements in room temperature semiconductor devices is also reported.
Due to the fast cooling of steam turbines, the shutdown time during maintenance or when repairing faults and damage can be shortened. This booklet describes various processes for cooling steam turbines. It is recommended that fast cooling should be planned in designing new plants and corresponding arrangements should be provided in the form of pipe connections and valves. (DG).
Often measures of protection and restoration of reinforced concrete structures are not taken until damage occurs which affects power plant operation. These failures can be avoided by predictive civil engineering maintenance and repair. The consequent application and implementation of a life-time management system for power plant buildings is being suggested. (orig.)
Occupational and environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls are linked with increased risk of hematologic malignancies. DOE facilities and waste sites in the U.S. are contaminated with mixtures of potentially hazardous chemicals such as metals, organic ligands, solvents, fuel hydrocarbons, polychlorinated biphenyls and radioactive isotopes. A major goal of this project was to establish linkage between chemical/radiation exposure and induction of genomic damage in target populations with the capability to undergo transformation.
Heterocyclic amines such as 2-amino-3-methylimidazo [4,5-f] quinoline (IQ) and 2-amino-3,8-dimethylimidazo [4,5-f] quinoxaline (MeIQx) are dietary carcinogens generated when meats are cooked...Full Text Available
Zn2+-finger proteins comprise one of the largest protein superfamilies with diverse biological functions. The ATM substrate Chk2-interacting Zn2+-finger protein...Full Text Available
With the Government decision to phase out the Fast Reactor at Dounreay there is a need to find alternative employment in the area. Traditionally Caithness is an area of farming, fishing and tourism which could be damaged if Dounreay were to be made a nuclear waste repository. The suggestion is that Dounreay should become a centre for research, development and subsequent manufacture of renewable energy sources and devices to harness renewable energy. The Scottish coastline has potential for wind and wave power developments and this could lead to a whole industry in the future. (UK).
The effect of the polyamine oxidase (PAO)-polyamine system on some helminths was examined in vitro. Both Schistosoma mansoni schistosomula and Dirofilaria immitis microfilariae were highly sensitive...Full Text Available
We determined the Na/K x-ray intensity ratio in frozen sections of myocardial tissues obtained at autopsy from patients who died from various causes, using electron probe analysis. We have been able to distinguish between the ischemically injured and normal cells. The method is simple, fast, and dependable even when the duration of ischemia is only 30 minutes.
Developing DB system of piping reliability including the population data and service history of damaged piping for pilot power plant. Total weld counts of shop welds, field welds and welds for measuring instruments for 14 systems of Kori unit 3. Total weld counts of shop welds, field welds and welds for measuring instruments for 12 systems of Wolsung unit 2.
Oryctes agamemnon (Burmeister 1847) (Coleoptera, Scarabaeidae) was accidentally introduced in the southwestern oases of Tunisia (Tozeur) around 1980 and spread to the Rjim Maatoug region. In these areas O. agamemnon was specific to date palm trees causing severe damage that can result in potential danger due to collapse of the tree. This study was conducted from April 2004 to March 2006 in 4 sites in the region of Rjim Maatoug. Different levels of palm tree attack were determined, ovioposition sites were identified, and pest damage was described in detail to specify their relative importance and to indicate factors governing palm tree attack. Eggs were individually oviposited in the attacked parts. Dead parts of palm trees were the main target of O. agamemnon including the respiratory roots, tough, trunk bark, dry petiole and the periphery of the crown. The crown itself was not attacked. Feeding by larvae caused significant ...
BackgroundInfertility affects ∼20% of couples in Europe and in 50% of cases the problem lies with the male partner. The impact of damaged DNA originating...Full Text Available
Investigation of an HP-blade damage in 1996 and an MP-blade damage in 1007 at the mounting showed that fretting and creep fatigue had caused the damage. Break-down occurred when creep-related cracks developed between radial bridge to the upper blade tooth and weight relief boreholes. After disassembly of the HP-blades the lower blade tooth was found to be cracked after fretting (some cracks along the whole length of the tooth). The lower teeth of MP-bladedes showed merely superficial cracks (depth about 0.4mm). The massive cracks of the lower blade tooth were caused by instationary clearance changes combined with hard blade underground.(orig.) [German] Das Ergebnis der Untersuchung nach einem HD-Schaufelschaden 1996 sowie einem MD-Schaufelschaden 1997 an der Vierzackenfussbefestigung ergab Zeitstanderschoepfung und Fretting als auszuloesende Schadensmechanismen. Die Havarien wurden durch zeitstandbedingte Brueche zwischen ...
In spite of extensive cooling water studies premature damage due to corrosion occurred on the CuZn20Al condenser tubes. It was then decided to incorporate new titanium-tubed condensers during the annual overhauls of 1983 and 1985 and also take ameliorating measures up to the exchange of individual condensers. (orig.).
1. It is not possible to give a threshold value for the dose - nor for genetic neither for somatic late effects. 2. The linear dose-effect exprapolation is not conservative in the sense of 'fying on the safe side'. 3. There has been found no relative reduction of the effects at chronic radiation exposure in man. 4 The numbers given by authorities and utilities for damage rates per rem received, that are called upper limits, are by far too low. (orig./HP).
Results on defect structure study and degree of molybdenum radiation hardening irradiated by fission neutrons and medium energy alpha-particles are presented. It is shown that molybdenum irradiation by alpha-particles and neutrons leads to different degree of material hardening for the same damage level. It is established that molybdenum radiation hardening is mainly defined by radiation defect clusters visible in electron microscope whose coefficient of rigidity depends on their size. 5 refs.; 6 figs.; 2 tabs. (author).
... However blaming vitamin supplements on deaths, or mortality is silly, as the studies are not exactly kosher. Vitamin C in 2,000mg is good for allergies, and niacin (b3) in 10,0000mg is good for depression. This is all examples on how vitamin supplements can help. I call it a security blanket, as food these days is not so good due vitamin and mineral damage due to light, or storage. By the time we eat the apple from the supermarket, there is minimal vitamin and ...
The CLIC (Compact Linear Collider) high-gradient RF structure testing program has been carried out in order to gain insight into the physical processes involved in RF breakdown, determine the mechanisms that limit gradient and produce damage so that technical concepts can be developed which allow higher accelerating gradients. Two main paths towards higher gradients have emerged from this program, and the performances of two new structures which incorporate them are presented.
The recently observed phenomenon of boron uphill diffusion during low-temperature annealing of ultrashallow ion-implanted junctions in silicon has been investigated. It is shown that the effect is enhanced by preamorphization, and that an increase in the depth of the preamorphized layer reduces uphill diffusion in the high-concentration portion of boron profile, while increasing transient enhanced diffusion in the tail. The data demonstrate that the magnitude of the uphill diffusion effect is determined by the proximity of boron and implant damage to the silicon surface.
While hydropower industry finds great profit opportunities in increased effective production, the host municipals have anxiety for great environmental damages. Regulations of water reservoirs. Differences between highest and lowest planned water level are specified in regulations for water reservoirs. The background for these regulations are both esthetic and environmental. (AG)
Topics of this proceedings are: DNA damage and repair; Space research; Cell and tissue radiobiology; Treatment planning 1: The role of clinical RBEs; Treatment planning 2: Dose optimization and inverse planning; Dosimetry; Clinical results of particle therapy and new techniques; Status reports and future developments. Separate abstracts were prepared for 79 chapters. (orig./SR)
Defects are produced in zinc by 6.1 MeV #alpha#-particle irradiation at 4.2 K and the subsequent recovery between 4.2 and 22 K. No evidence is found for free migration of an interstitial in the temperature range investigated. The recovery spectra reveal a series of substages which are ascribed to recombination of close Frenkel pairs. (author).
Point defect injection studies are performed to investigate how fluorine implantation influences the diffusion of boron marker layers in both the vacancy-rich and interstitial-rich regions of the fluorine damage profile. A 185 keV, 2.3x10"1"5 cm"-"2 F"+ implant is made into silicon samples containing multiple boron marker layers and rapid thermal annealing is performed at 1000 deg. C for times of 15-120 s. The boron and fluorine profiles are characterized by secondary ion mass spectroscopy and the defect structures by transmission electron microscopy (TEM). Fluorine implanted samples surprisingly show less boron diffusion under interstitial injection than those under inert anneal. This effect is particularly noticeable for boron marker layers located in the interstitial-rich region of the fluorine damage profile and for short anneal times (15 s). TEM images show a band of dislocation loops around the range of the fluorine implant and the ...
The 2- and 8-azido trimer 5'-triphosphate photoprobes of 2-5A have been enzymatically synthesized from [#gamma#-"3"2P]2-azidoATP and [#alpha#-"3"2P]8-azidoAPT by 2-5A synthetase from rabbit reticulocyte lysates. Identification and structural determination of the 2- and 8-azido adenylate trimer 5'-triphosphates were accomplished by enzymatic hydrolyses with T2 RNase, snake venom phosphodiesterase, and bacterial alkaline phosphatase. Hydrolysis products were identified by HPLC and PEI-cellulose TLC analyses. The 8-azido photoprobe of 2-5A displaces p_3A_4["3"2P]pCp from RNase L with affinity equivalent to p_3A_3. The 8-azido photoprobe also activates RNase L to hydrolyze poly(U)["3"2P]pCp 50% at 7 /times/ 10/sup /minus/9/ M in core-cellulose assays. The 2- and 8-azido photoprobes and authentic p_3A_3 activate RNase L to cleave 28S and 18S rRNA to specific cleavage products at 10/sup /minus/9/ M in rRNA cleavage assays. The nucleotide binding site(s) of RNase L and/or ...
Thirty-seven patients with primary nonresectable intrahepatic cholangiocarcinoma (57% with prior treatment and/or metastasis) were prospectively treated with external radiation, chemotherapy, and "1"3"1I labelled anti-CEA. Therapy began in all trials with whole liver irradiation (21.0 Gy, 3.0 Gy/Fx, 4 days/week, 10 MV photons) with alternate treatment day chemotherapy (Adriamycin, 15 mg + 5-FU, 500 mg). One month after external beam therapy, chemotherapy was given (Adriamycin, 15 mg + 5-FU, 500 mg) followed the next day by the first administration of "1"3"1I anti-CEA. The treatment schedule used was 20 mCi day 0; 10 mCi day 5 as an outpatient. This schedule was derived from tumor dose estimates which indicated that 20 mCi (8-10 mCi/mg IgG) was sufficient to achieve tumor saturation with a tumor effective half-life of 3 to 5 days, depending upon the species of animal from which the antibody was obtained. The median tumor dose for the 20 mCi + 10 mCi regimen was 6.2 Gy. Antibody therapy ...
The waterjet technique enables precise tissue dissection without thermal damage and with preservation of vessels in general surgery. In neurosurgery, these qualities could help to avoid damage of intact brain parenchyma in tumour resections. The present study reports our first results with this technique in brain metastases. Ten patients with intracranial metastases underwent surgery with the aid of the waterjet. Resection was performed in combination with conventional neurosurgical methods. The follow-up consisted of neurological examination and MRI studies. Intraoperatively, the device was easy to handle. No complications due to the device were observed. Vessels were preserved at pressures below 20 bars. Six of the tumours consisted of soft tissue which was poorly demarcated from the surrounding brain. In these tumours, the waterjet was very helpful. It enabled tumour debulking by aspiration and - more important - precise separation of tumour ...
Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during initial annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, the authors have used B doping marker layers in Si to probe the injection of interstitials from near-surface, non-amorphizing Si implants during annealing. The in-diffusion of interstitials is limited by trapping at impurities and has an activation energy of {approximately}3.5 eV. Substitutional C is the dominant trapping center with a binding energy of 2--2.5 eV. The high interstitial supersaturation adjacent to the implant damage drives substitutional B into metastable clusters at concentrations below the B solid solubility limit. Transmission electron microscopy shows that the interstitials driving TED are emitted from {l_brace}311{r_brace} defect clusters in the damage region at a rate which also exhibits an activation energy of 3.6 ...
Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during initial annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, the authors have used B doping marker layers in Si to probe the injection of interstitials from near-surface, non-amorphizing Si implants during annealing. The in-diffusion of interstitials is limited by trapping at impurities and has an activation energy of #approx#3.5 eV. Substitutional C is the dominant trapping center with a binding energy of 2--2.5 eV. The high interstitial supersaturation adjacent to the implant damage drives substitutional B into metastable clusters at concentrations below the B solid solubility limit. Transmission electron microscopy shows that the interstitials driving TED are emitted from #left brace#311#right brace# defect clusters in the damage region at a rate which also exhibits an activation energy of 3.6 ...
Assessments of the hardening and embrittlement of pressure vessel steels and welds as a function of neutron dose use trend curves derived from surveillance programs and accelerated irradiation data. A temperature dependent factor is incorporated for assessing vessel locations operating at different temperatures. As hardening and embrittlement arise from the sum of matrix damage and copper impurity precipitation, the influence of irradiation temperature on each process needs to be established. For irradiations performed below #approx# 300 C recent data shows that the dose-dependent growth of copper precipitates ceases at a mean diameter of about 2 nm that also corresponds to peak hardening and embrittlement by copper. For doses beyond this peak copper dose the property-dependence on irradiation temperature can be identified with that of matrix damage alone. An analysis of several experiments on plate steels, performed at differing irradiation ...
Behavior to hydrogen damage caused by stress corrosion in a H_2S medium (SSC) and to intergranular corrosion (IGC) in different mediums, such as oxalic acid (C_2H_2.2H_2O), iron sulphate-50% sulfuric acid (Fe_2(SO_4)_3-50% H_2SO_4), nitric acid (HNO_3), copper sulphate-16% sulfuric acid (CuSO_4.5H_2O-16% H_2SO_4) and cooper sulphate-50% sulfuric acid (CuSO_4.5H_2O-50% H_2SO_4), is studied in an AISI 347 austenitic stainless steel stabilized with 0.61 mass % Nb and hot rolled to a seamless pipe with 273.1 mm in diameter and 18.2 mm in thickness. (Author) 12 refs.
Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers adjacent tothe substrateremained intact even ...
Thinning specimens to electron transparency for electron microscopy analysis can be done by conventional (2-4 kV) argon ion milling or focused ion beam (FIB) lift-out techniques. Both these methods tend to leave 'mottling' visible on thin specimen areas, and this is believed to be surface damage caused by ion implantation and amorphisation. A low energy (250-500 V) Argon ion polish has been shown to greatly improve specimen quality for crystalline silicon samples. Here we investigate the preparation of technologically important materials for nanoanalysis using conventional and lift-out methods followed by a low energy polish in a GentleMill"T"M low energy ion mill. We use a low energy, low angle (6-8 deg.) ion beam to remove the surface damage from previous processing steps. We assess this method for the preparation of technologically important materials, such as steel, silicon and GaAs. For these materials the ability to create specimens from ...
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 the patient does not allow more aggressive reconstructive procedures, fistula repair ...
Radiation damage studies have been carried out on undoped and CrO_4"2"- doped potassium and ammonium alums. The optical absorption bands observed around 27100 and 36500 cm"-"1 before irradiation have been attributed to the transitions t_1 #-># e and t_1 #-># t_2, on the basis of Ball-hausen and Liehr scheme. On prolonged X-irradiation, these bands disappear in both the alums and three new bands seem to grow in ammonium alum while only two new bands could be seen in potassium alum. EPR studies at RT reveal that there are two lines at g = 2.004 and g = 2.010 in ammonium alum and only one line at g = 2.004 in potassium alum. Besides these two nearly isotropic lines, there is a set of lines around g = 1.95 in both the alums. Correlating the optical and EPR studies it is concluded that SO_3"- and O_3"- centres have formed on X-irradiation in ammonium alum while only SO_3"- seems to have formed in potassium alum. The most important feature is the formation of a new ...
This report has reviewed the construction of a cooling tower for the K reactor at the DOE Savannah River Site in Aiken, South Carolina. It has been found that the cooling tower would prevent further destruction of cypress and tupelo trees, would maintain a more consistent flow from site streams, and would allow earlier recovery of stream corridors inside a portion of the site. About 630 acres of wetlands have already been affected by the hot water discharged by the K reactor during the past 35 years. GAO believes that about 10 to 12 acres of additional damage would be prevented by the tower for every year the reactor is operated, and if current plans for re-start and retirement of the reactor are followed, less than 100 acres would be preserved. As requested, GAO also identified an example of a project that could be funded as compensation to the public for the damage the K reactor would do if Congress exempted it from the Clean Water Act and ...
The analysis described demonstrates the use of benefit/cost sensitivity analysis in examining the wide range of potential damages and savings associated with converting oil-fired electric utility boilers to burn coal in Florida. This model, for the first time incorporates, in quantitative terms, environmental economic externalities into a benefit/cost ratio sensitivity analysis framework. Five different dose-response estimates of morbidity and mortality costs, property devaluation, and willing-to-pay estimates are used in combination with four acid rain dose-response models to estimate the net present worth of externality costs. The model estimates the net present worth of benefits by incorporating into a dynamic framework all relevant construction, O + M, and fuel costs of converting an electrical generation facility from using oil to coal. These benefits of fuel savings are then weighted against various combinations of externality costs associated with increased ...
This report briefly describes the studies on the mechanism of in vivo DNA repairing by the author in Research Reactor Institute, Kyoto Univ. for the past 30 years. First, the ability of UV radiation to induce transformation was investigated with viral DNA. The formation of thymine-thymine dimer was found harmful to organisms and such dimers were removable by UV-radiation at a low frequency. The mutability was determined in three different E.coli strains with mutator gene, mutT, mutS or mutL. The ability to excise 8-oxoguanin developed in primer DNA was deficient in mutT and miss-pairing left after DNA replication could not be recovered in mutL and mutS strains. Further, DNA repairing mechanism was investigated in other microorganisms; single-strand cleavage caused by exposure to BNCB radiation (boron-neutron-captured beam) could not be repaired in E. coli. Whereas for Deinococcus radiodurans, of which survival rate was not decreased by #gamma#-ray radiation at 5 kGy or less, it was ...
Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas ...
Measurements of the Kapitza conductance to liquid helium II across the (100) surface of single crystals of copper are presented. The temperature range of these measurements was 1.6-- 2.1 K. The sample surfaces were subjected to several different treatments. Some surfaces were cleaned by low-energy argon ion bombardment, annealed in an ultrahigh-vacuum system, and preserved under vacuum until purified liquid helium was admitted. Other surfaces were intentionally damaged by machining and/or exposure to the atmosphere. The conductance after these latter treatments was found to be about a factor of three higher than that of the more ideally cleaned and annealed surfaces, and a significant difference in the temperature dependence of the conductance was also observed. Conductances were reproducible for similarly treated surfaces and correlated with surface damage determined by x-ray diffraction. The relationship of these results to the numerous ...
This paper examines the global impacts of a policy that internalizes the external costs (related to air pollution damage, excluding climate costs) of electricity generation using a combined energy systems and macroeconomic model. Starting point are estimates of the monetary damage costs for SO{sub 2}, NO {sub X} , and PM per kWh electricity generated, taking into account the fuel type, sulfur content, removal technology, generation efficiency, and population density. Internalizing these externalities implies that clean and advanced technologies increase their share in global electricity production. Particularly, advanced coal power plants, natural gas combined cycles, natural gas fuel cells, wind and biomass technologies gain significant market shares at the expense of traditional coal- and gas-fired plants. Global carbon dioxide emissions are lowered by 3% to 5%. Sulfur dioxide emissions drop significantly below the already low level. The ...
This paper examines the global impacts of a policy that internalizes the external costs (related to air pollution damage, excluding climate costs) of electricity generation using a combined energy systems and macroeconomic model. Starting point are estimates of the monetary damage costs for SO{sub 2}, NOX, and PM per kWh electricity generated, taking into account the fuel type, sulfur content, removal technology, generation efficiency, and population density. Internalizing these externalities implies that clean and advanced technologies increase their share in global electricity production. Particularly, advanced coal power plants, natural gas combined cycles, natural gas fuel cells, wind and biomass technologies gain significant market shares at the expense of traditional coal- and gas-fired plants. Global carbon dioxide emissions are lowered by 3% to 5%. Sulfur dioxide emissions drop significantly below the already low level. The policy ...
the cotton leaf worm, Spodoptera littoralis (boisd.) were irradiated with 100,150 and 200 Gy to induce inherited sterility. the effects of the tested doses applied to these pupae through three consequent fillial generations and the retarded influence on their F_1,F_2 and F_3 generations progeny were examined . irradiation of parental male induced damage to their daughter females ovaries. the overioles of females among P_1 ,F_1 and F_2 generations showed that the follicular epithelial cells appeared abnormal beside their limited separation from developing oocytes which became shrinked, semi absorbed or completely absorbed leaving vacuoles. the nurse cells were reduced or absent in some parts. damage was obvious through the first and second generations especially at 150 and 200 Gy. in the third generation, ovaries were not greatly affected
A 25m wind turbine blade was tested to failure when subjected to a flapwise load. With the test setup, it was possible to test the blade to failure at three diffe-rent locations. The objective of these tests is to learn about how a wind turbine blade fails when exposed to a large flapwise load and how failures propagate. The report shows also results from ultra sonic scan of the surface of the blade and it is seen to be very useful for the detection of defects, especially in the layer between the skin laminate and the load carrying main spar. Acoustic emission was successfully used as sensor for the detection of damages in the blade during the test. The report contains measurements of the total deflection of the blade, the local deflection of the skin and the load carrying main spar and also measurement of strain all as a function of the applied load and up to failure of the blade. The 'post mortem' analysis and description of how the ...
The authors report on the nano-fabrication of GaN/AlGaN device structures using focused ion beam (FIB) etching, illustrated on a GaN/AlGaN heterostructure field effect transistor (HFET). Pillars as small as 20nm to 300nm in diameter were fabricated from the GaN/AlGaN HFET. Micro-photoluminescence and UV micro-Raman maps were recorded from the FIB-etched pattern to assess its material quality. Photoluminescence was detected from 300nm-size GaN/AlGaN HFET pillars, i.e., from the AlGaN as well as the GaN layers in the device structure, despite the induced etch damage. Properties of the GaN and the AlGaN layers in the FIB-etched areas were mapped using UV Micro-Raman spectroscopy. Damage introduced by FIB-etching was assessed. The fabricated nanometer-size GaN/AlGaN structures were found to be of good quality. The results demonstrate the potential of FIB-etching for the nano-fabrication of III-V nitride devices.
The synergistic effects of displacement damage and atomic hydrogen and helium on swelling of the ferritic/martensitic steel, F82H, has been investigated. The irradiation was performed at temperatures between 470 and 600 deg. C to 50 dpa (displacement per atoms) under conditions of simultaneous ion beams consisting of Fe{sup 3+}, He{sup +} and H{sup +} ions or Fe{sup 3+} and He{sup +} ions. The swelling of F82H steel under triple beams with 18 appm He/dpa and 70 appm H/dpa was larger than that under dual beams with 18 appm He/dpa. The swelling in F82H under triple beams increased with decreasing irradiation temperature from 0.1% to 3.2%, while swelling under dual beams was between 0.04% and 0.08%. On the other hand, in the case of triple beam irradiation with a high ratio of gas/dpa, the swelling tended to increase with irradiation temperature. The swelling in ferritic/martensitic steels is significantly enhanced by the synergistic effect of displacement ...
The synergistic effects of displacement damage and atomic hydrogen and helium on swelling of the ferritic/martensitic steel, F82H, has been investigated. The irradiation was performed at temperatures between 470 and 600 deg. C to 50 dpa (displacement per atoms) under conditions of simultaneous ion beams consisting of Fe"3"+, He"+ and H"+ ions or Fe"3"+ and He"+ ions. The swelling of F82H steel under triple beams with 18 appm He/dpa and 70 appm H/dpa was larger than that under dual beams with 18 appm He/dpa. The swelling in F82H under triple beams increased with decreasing irradiation temperature from 0.1% to 3.2%, while swelling under dual beams was between 0.04% and 0.08%. On the other hand, in the case of triple beam irradiation with a high ratio of gas/dpa, the swelling tended to increase with irradiation temperature. The swelling in ferritic/martensitic steels is significantly enhanced by the synergistic effect of displacement damage, ...
Human hair fibers experience tensile forces during grooming and styling processes. The tensile response of hair is hence of considerable interest to the cosmetics industry. In this study, in situ tensile characterization studies have been carried out in an atomic force microscope (AFM) on different hair under different conditions. A custom-built AFM sample stage allows hair fibers to be loaded in tension. A technique to locate and image the same control area at different strains has been developed to study the changes in morphology that occur with deformation. Virgin Caucasian, Asian and African hair were studied to understand the differences between different ethnic hair types. Also, the tensile response and morphological changes of virgin, chemically damaged and conditioner-treated Caucasian hair after soaking were compared against the corresponding dry tensile response. Finally, virgin, damaged and treated Caucasian hair fibers were ...
The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, and reconstruction of an electron density ...
A total of 10 samples disks of 2024-T3 aluminum and 4130 ferrous steel were exposed to rocket-triggered lightning currents at the Kennedy Space Center test site in Florida during the summer of 1990. The experimental configuration was arranged so that the samples were not exposed to the preliminary streamer, wire-burn, or following currents that are associated with an upward-initiated rocket-triggered flash but which are a typical of naturally initiated lightning. Return-stroke currents and continuing currents actually attaching to the sample were measured, augmented by close-up video recordings of approximately 3 feet of the channel above the sample and by 16-mm movies with 5-ms resolution. From these data it was possible to correlate individual damage spots with streamer, return-stroke, and continuing currents that produced them. Substantial penetration of 80-mil aluminum was produced by a continuing current of submedian amplitude and duration, and full ...
Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited to describe our ...
The author investigates the diffusion and damage-annealing characteristics as a result of boron implantation through a surface oxide into the silicon, a process that is commonly realized in the fabrication of p-n junctions. Defect structures were examined using plan-view and cross-section transmission-electron microscopies. It is shown that recoil-implanted oxygen plays a critical role in determining the above annealing characteristics. For instance, transient-enhanced diffusion of boron, as is widely observed for boron-implanted silicon, does not occur in the case of through-oxide implantation. The initial suppression of the defect-enhanced diffusion lasts for a limited period of time after which enhanced diffusion occurs again. The so-called incubated enhanced diffusion' is characterized as due to recoiled-oxygen precipitation-emitting point defect that enhances boron motion. The incubation time constant, the magnitude for the enhanced diffusion, and the ...
The author investigates the diffusion and damage-annealing characteristics as a result of boron implantation through a surface oxide into the silicon, a process that is commonly realized in the fabrication of p-n junctions. Defect structures were examined using plan-view and cross-section transmission-electron microscopies. It is shown that recoil-implanted oxygen plays a critical role in determining the above annealing characteristics. For instance, transient-enhanced diffusion of boron, as is widely observed for boron-implanted silicon, does not occur in the case of through-oxide implantation. The initial suppression of the defect-enhanced diffusion lasts for a limited period of time after which enhanced diffusion occurs again. The so-called incubated enhanced diffusion' is characterized as due to recoiled-oxygen precipitation-emitting point defect that enhances boron motion. The incubation time constant, the magnitude for the enhanced diffusion, and the ...
Chicken embryos were x-irradiated in ovo with 5-30 cGy (=priming dose) at the 13th-15th day of development. After 3-48 h, brain- and liver-cell suspensions were x-irradiated in vitro with (challenge) doses of 4-32 Gy. Significantly less radiation damage was observed when the radiation response was measured by scheduled DNA synthesis, nucleoid sedimentation and viscosity of alkaline cell lysates 12-36 h after the priming exposure. In vivo, pre-irradiation with 10 cGy enhanced regeneration as evidenced by the DNA content of chicken embryo brain and liver 24 h following a challenge dose of 4 Gy. From nucleoid sedimentation analyses in brain and liver cells immediately after irradiation with 16 Gy and after a 30-min repair period in the presence of aphidicolin, dideoxythymidine and 3-aminobenzamide or in the absence of these DNA repair inhibitors, it is concluded that a reduction of the initial radiation damage is the dominant mechanism of the ...
Kerf geometry, kerf wall features, and cutting front characteristics of an Abrasive Waterjet (AWJ) machined Graphite/Epoxy (Gr/Ep) laminate were studied. A macroscopic analyses suggests that geometrical features associated with AWJ machining of Gr/Ep laminates are influenced by three macro regions along the cutting depth. The presence of these regions, including initial damage at jet entry, smooth cutting, and rough cutting near the jet exit, depends on the operating conditions. Design of experiments and analysis of variance were used to determine the effect of cutting parameters on kerf characteristics and to develop empirical models for kerf profile and features of the three distinct macroscopic regions. Cutting front analysis revealed that the mechanisms of material removal in AWJ machining of Gr/Ep do not change over the jet penetration depth. In general, high quality uniform cuts may be obtained by minimizing initial damage at the jet ...
This paper provides a physically-based engineering model to estimate radiation hardening of 9%Cr-steels under both displacement damage (dpa) and helium. The model is essentially based on the dispersed barrier hardening theory and the dynamic re-solution of helium under displacement cascades but incorporating a number of assumptions and simplifications [Trinkaus, J. Nucl. Mater. 318 (2003) 234-340]. As a result, the kinetics of the damage accumulation kept fixed, its amplitude is fitted on one experimental condition. The model was rationalized on an experimental database that mainly consists of ?9%Cr-steels irradiated in the range of 50-600 deg. C up to 50 dpa and with a He-content up to 5000 appm. The test temperature effect is taken into account through a normalization procedure based on the change of the Young's modulus and the anelastic deformation that occurs at high temperature. Despite the large experimental scatter, inherent to the ...